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This is a continuation in part of U.S. patent application Ser. No. 09/122,137 filed Jul. 24, 1998.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates generally to systems and methods for mapping, and specifically to methods of mapping of intrabody organs.
Cardiac mapping is used to locate aberrant electrical pathways and currents within the heart, as well as mechanical and other aspects of cardiac activity. Various methods and devices have been described for mapping the heart. Such methods and device are described, for example, in U.S. Pat. Nos. 5,471,982, 5,391,199 and 5,718,241 and in PCT patent publications WO94/06349, WO96/05768 and WO97/24981. U.S. Pat. No. 5,391,199, for example, describes a catheter including both electrodes for sensing cardiac electrical activity and miniature coils for determining the position of the catheter relative to an externally-applied magnetic field. Using this catheter a cardiologist may collect a set of sampled points within a short period of time, by determining the electrical activity at a plurality of locations and determining the spatial coordinates of the locations.
In order to allow the surgeon to appreciate the determined data, a map, preferably a three dimensional (3D) map, including the sampled points is produced. U.S. Pat. No. 5,391,199 suggests superimposing the map on an image of the heart. The positions of the locations are determined with respect to a frame of reference of the image. However, it is not always desirable to acquire an image, nor is it generally possible to acquire an image in which the positions of the locations can be found with sufficient accuracy.
Various methods are known in the art for reconstructing a 3D map of a cavity or volume using the known position coordinates of a plurality of locations on the surface of the cavity or volume. Some methods include triangulation, in which the map is formed of a plurality of triangles which connect the sampled points. In some cases a convex hull or an alpha-hull of the points is constructed to form the mesh, and thereafter the constructed mesh is shrunk down to fit on the sampled points within the hull. Triangulation methods do not provide a smooth surface and therefore require additional stages of smoothing.
Another method which has been suggested is forming a bounding ellipsoid which encloses the sampled points. The sampled points are projected onto the ellipsoid, and the projected points are connected by a triangulation method. The triangles are thereafter moved with the sampled points back to their original locations, forming a crude piecewise linear approximation of the sampled surface. However, this method may reconstruct only surfaces which have a star shape, i.e., a straight line connecting a center of the reconstructed mesh to any point on the surface does not intersect the surface. In most cases heart chambers do not have a star shape.
In addition, reconstruction methods known in the art require a relatively large number of sampled locations to achieve a suitable reconstructed map. These methods were developed, for example, to work with CT and MRI imaging systems which provide large numbers of points, and therefore generally work properly only on large numbers of points. In contrast, determining the data at the locations using an invasive catheter is a time-consuming process which should be kept as short as possible, especially when dealing with a human heart. Therefore, reconstruction methods which require a large number of determined locations are not suitable.
One important example of cardiac mapping is the determination of the speed and direction of propagation of electrical signals through the tissue of the heart. Abnormal propagation velocity, or vortical signal flow, may be diagnostic of locally diseased heart tissue that should be treated, for example by ablation. Typically, the velocity of propagation of cardiac signals is measured by sensing the wavefronts at a plurality of electrodes in contact with the inner surface of a chamber of the heart. A representative example of the prior art in this field is Kadish, et al., “Vector Mapping of Myocardial Activation”, Circulation, Vol. 74, No. 3, Pages 603-615 (September 1986), in which vectors based on activation maps are drawn perpendicular to the isochrome tangent. Kadish et al. describes the measurement of the timing of local depolarization events, using an array of electrodes, for the purpose of deriving propagation velocities. This propagation velocity deriving technique is also described in Gerstenfeld et al., “Evidence for Transient Linking of Atrial Excitation During Atrial Fibrillation in Humans”, Circulation, Vol. 86, No. 2, Pages 375-382 (August 1992) and Gerstenfeld et al., “Detection of Changes in Atrial Endocardial Activation with Use of an Orthogonal Catheter”, J. Am. Coll. Cardiol. 1991; 18:1034-42 as well as U.S. Pat. No. 5,487,391 (Panescu).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method for mapping a 3D volume or cavity, based on the positions of points on a surface of the volume or cavity.
It is an object of some aspects of the present invention to provide methods and apparatus for generating a map of a volume in the human body from a plurality of sampled points, regardless of the shape of the volume.
It is another object of some aspects of the present invention to provide a simple, rapid method for reconstructing a 3D map of a volume in the human body from a plurality of sampled points, preferably using fewer sampled points than is feasible using methods known the art.
It is another object of preferred embodiments of the present invention to provide a method for reconstructing a 3D map of a volume in the human body from a plurality of sampled points, without assuming any topological relationship between the points.
It is another object of some aspects of the present invention to provide a simple method for reconstructing a 3D map of a volume in movement.
It is another object of some aspects of the present invention to provide a simple method for reconstructing a 3D map of a volume in the human body from a plurality of sampled points independent of the sampling order.
It is another object of some aspects of the present invention to provide a quick method for reconstructing a 3D map of a volume in the human body from a plurality of sampled points, such that the method may be used in interactive procedures.
It is another object of some aspects of the present invention to provide a method for reconstructing a smooth 3D map of a volume in the human body from a plurality of sampled points.
In preferred embodiments of the present invention, a processor reconstructs a 3D map of a volume or cavity in a patient's body (hereinafter referred to as the volume), from a plurality of sampled points on the volume whose position coordinates have been determined. In contrast to prior art reconstruction methods in which a large number of sampled points are used, the preferred embodiments of the present invention are directed to reconstruction of a surface based on a limited number of sampled points. The number of sampled points is generally less than 200 points and may be less than 50 points. Preferably, ten to twenty sampled points are sufficient in order to perform a preliminary reconstruction of the surface to a satisfactory quality.
An initial, generally arbitrary, closed 3D curved surface (also referred to herein for brevity as a curve) is defined in a reconstruction space in the volume of the sampled points. The closed curve is roughly adjusted to a shape which resembles a reconstruction of the sampled points. Thereafter, a flexible matching stage is preferably repeatedly performed once or more to bring the closed curve to accurately resemble the shape of the actual volume being reconstructed. Preferably, the 3D surface is rendered to a video display or other screen for viewing by a physician or other user of the map.
In preferred embodiments of the present invention, the initial closed curved surface encompasses substantially all the sampled points or is interior to substantially all the sampled points. However, it is noted that any curve in the vicinity of the sampled points is suitable. Preferably, the closed 3D curved surface comprises an ellipsoid, or any other simple closed curve. Alternatively, a non-closed curve may be used, for example, when it is desired to reconstruct a single wall rather than the entire volume.
A grid of a desired density is defined on the curve, and adjustment of the curve is performed by adjusting the grid points. The grid preferably divides the curved surface into quadrilaterals or any other polygons such that the grid evenly defines points on the curve. Preferably, the grid density is sufficient such that there are generally more grid points than sampled points in any arbitrary vicinity. Further preferably, the grid density is adjustable according to a desired compromise between reconstruction accuracy and speed.
In some preferred embodiments of the present invention, external information is used to choose an initial closed curve which is more closely related to the reconstructed volume, for example, using the image of the volume, as described above. Thus, the reconstruction procedure may produce a more accurate reconstruction in less time. Alternatively or additionally, a database of closed curves suitable for various volumes of the body is stored in a memory, and the curve to be used is chosen according to the specific procedure. In a further preferred embodiment of the present invention, a map of a reconstructed volume in a patient is used as a beginning curve for subsequent mapping procedures performed at later times on the same volume.
Preferably, the rough adjustment of the closed curve is performed in a single iteration, most preferably by calculating for each grid point an adjustment point, and moving the grid point a fraction of the distance to the adjustment point. Preferably, the grid point is moved about 50-80% of the distance between its original point and the adjustment point, more preferably about 75%.
The adjustment point is preferably determined by taking a weighted sum over substantially all the sampled points. Preferably, the weights are inversely related to the distances from the adjusted grid point to the sampled points, referred to herein as grid distances. In a preferred embodiment of the present invention, each weight is defined as the reciprocal of the sum of a small constant plus the grid distance, raised to a predetermined power, so that sampled points close to the grid point are given a larger weight. Preferably, the power is approximately between 4 to 9, most preferably 8. The small constant is preferably smaller than the magnitude of the smallest grid distance, and is preferably of the size of the accuracy of the determination of the coordinates of the sampled points. The small constant is used to prevent division by zero when a grid-point is on a sampled point.
In some preferred embodiments of the present invention, the weights also include a factor which is indicative of the density of points in the vicinity of their corresponding point. Preferably, the weight is multiplied by a density value between zero and one, indicative of the density, such that isolated sampled points influence the sum more than sampled points in a dense area. Preferably, the influence of the points is thus substantially independent of the density of points in their vicinity.
In a preferred embodiment of the present invention, the flexible matching step is performed by associating each sampled point with a corresponding grid-point, such that each sampled point is associated with the grid point which is closest to it. A movement vector is calculated for each of the associated and non-associated grid-points. Preferably, the movement vectors are calculated based on vectors from the associated grid points to their respective sampled points. Further preferably, the sampled points influence the value of the movement vector for a specific point according to their proximity to the specific point. In addition, the function by which the movement vectors are calculated is preferably smooth and does not include complicated calculations. Preferably, the function is a weighted sum of the vectors from the associated grid points to their respective sampled points. The grid points are then moved according to their respective movement vectors.
Additionally or alternatively, the associated grid points are moved toward their corresponding sampled points by a percentage of the distance between them. Those grid points which are not associated with a sampled point are moved a distance which is determined by interpolation between the distances which surrounding points on the grid are moved. Preferably, the resulting grid is smoothed using a suitable smoothing transformation. Preferably, the process of associating and moving is repeated two or more times to allow finer adjustment of the closed curve.
In a preferred embodiment of the present invention, a user can adjust the number of times the flexible matching step is repeated according to a desired compromise between image quality and speed. Alternatively or additionally, a quick reconstruction is first provided to the user, and thereafter the calculation is repeated to receive a finer reconstruction. Preferably, the weights of the weighted sum used in the flexible matching stage are adjusted according to the number of times the matching is to be performed. Alternatively or additionally, the weights are determined for each flexible matching step according to its place in the sequential order of the flexible matching steps.
Preferably, the distances used for the weights and/or for interpolation are Euclidean geometrical distances between the points. The Euclidean distance is easily computed and causes points on opposite walls of the volume to mutually repel, so that the walls do not intersect. Alternatively, other distances, such as the distance along the original or adjusted grid, may be used. In a preferred embodiment of the present invention, during the first flexible matching step the distance used is the distance along the original grid while subsequent flexible matching steps use the Euclidean distance.
In some preferred embodiments of the present invention, a smoothing process is applied to the reconstructed surface, preferably by applying a surface convolution with a Gaussian-like kernel. The smoothing process provides a better approximation of the surface and allows easier performance of calculations based on the reconstructed surface. However, applying the surface convolution results in some shrinkage of the surface, and therefore an affine transformation is preferably performed on the smoothed surface. The affine transformation is preferably chosen according to those sampled points which are external to the reconstructed surface. The chosen affine transformation preferably minimizes the mean square distance of the external points to the surface.
Preferably, when the reconstruction is finished, each sampled point substantially coincides with a grid point. In some preferred embodiments of the present invention, a final exact matching stage is performed. Each sampled point is associated with a closest grid point, and the associated grid point is moved onto the sampled point. The rest of the grid points are preferably not moved. Generally, most of the sampled points are by this stage very close to the reconstructed surface, and therefore the smoothness of the surface is substantially not affected. However, some outlier sampled points, i.e., sampled points which do not belong to the surface, may cause substantial changes to the surface. Preferably, the user may determine whether to move the surface onto points that are distanced from the surface by more than a predetermined maximum distance. Alternatively or additionally, the entire exact matching step is optional and is applied only according to a user request.
Further alternatively or additionally, the grid points are brought to a fixed distance from the sampled points. Leaving such a fixed distance may be desired, for example, when the sampled coordinates are of locations close to a distal tip of a sampling catheter rather than at the distal tip itself.
In preferred embodiments of the present invention, data regarding the sampled points are acquired by positioning a catheter within the volume which is to be reconstructed, for example, within a chamber of the heart. The catheter is positioned with a distal end thereof in contact with each of the sampled points in turn, and the coordinates of the points and, optionally, values of one or more physiological parameters are sensed at a distal end of the catheter. Preferably, the catheter comprises a coordinate sensor close to its distal end, which outputs signals indicative of the coordinates of the tip of the catheter. Preferably, the coordinate sensor determines the position by transmitting and receiving electromagnetic waves, as described, for example, in PCT publications GB93/01736, WO94/04938, WO97/24983 and WO96/05768, or in U.S. Pat. No. 5,391,199, which are all incorporated herein by reference.
In some preferred embodiments of the present invention, the reconstructed volume is in movement, for example, due to beating of the heart. In such embodiments, the sampled points are preferably registered with a reference frame fixed to the heart. Preferably, a reference catheter is fixed in the heart, and the sampled points are determined together with the position of the reference catheter which is used to register the points, as described, for example, in the above-mentioned U.S. Pat. No. 5,391,199 and PCT publication WO96/05768.
Alternatively or additionally, when at least part of the movement is a cyclic movement, as in the heart, acquisition of the sampled points is synchronized to a specific time point of the cycle. Preferably, when the sampled volume is in the heart, an ECG signal is received and is used to synchronize the acquisition of the sampled points. For example, the sampled points may be acquired at end diastole. Further alternatively or additionally, the coordinates of each of the sampled points are determined together with an indication of the time point relative to the cyclic movement in which the coordinates were acquired. Preferably, the indication includes the relative time from the beginning of the cycle and the frequency of the cyclic movement. According to the frequency and the relative time, the determined coordinates are corrected to end diastole, or any other point in the cyclic movement.
In some preferred embodiments of the present invention, for each sampled point a plurality of coordinates are determined at different time points of the cyclic movement. In one of these preferred embodiments, each sampled point has two coordinates which define the range of movement of the point. Preferably, if the plurality of coordinates of different points are associated with different cycle frequencies, the coordinates are transformed so as to correspond to a set of coordinates in a single-frequency cyclic movement. Further preferably, the coordinates are processed so as to reduce or substantially eliminate any contribution due to movement other than the specific (cardiac) cyclic movement, such as movement of the chest due to respiration. Reconstruction is performed for a plurality of configurations of the volume at different time points of the cyclic movement. Preferably, a first reconstruction is performed as described above to form an anchor reconstruction surface, and reconstruction of surfaces for other time points of the cycle are performed relative to the anchor reconstruction surface.
Preferably, for each further time point of the cyclic movement, the anchor surface is adjusted according to the coordinates of the sampled points at the further time point relative to the coordinates of the sampled points of the anchor surface. Preferably, the anchor surface is adjusted by a quadratic transformation which minimizes a mean square error, the error representing the distances between the sampled points of the further time point and the adjusted surface. Alternatively or additionally, an affine transformation is used instead of the quadratic transformation. Further alternatively or additionally, a simple transformation is used for surfaces having relatively few sampled points, while surfaces with a relatively large number of sampled points a quadratic transformation is used. The simple transformation may be an affine transformation, a scaling and rotation transformation, a rotation transformation, or any other suitable transformation.
Preferably, the adjustment of the surface for the further time points includes, after the transformation, one or more, preferably two, flexible matching steps and/or an exact matching stage.
Alternatively or additionally, the reconstruction is performed separately for each of the further time points. Further alternatively or additionally, a first reconstruction of the surfaces for the further time points is performed relative to the anchor surface, and afterwards a more accurate reconstruction is performed for each time point independently.
In some preferred embodiments of the present invention, dedicated graphics hardware which is designed to manipulate polygons is used to perform the reconstruction stages described above.
In some preferred embodiments of the present invention, one or more physiological parameters are acquired at each sampled point. The physiological parameters for the heart may comprise a measure of cardiac electrical activity, for example, and/or may comprise any other type of local information relating to the heart, as described in the above-mentioned PCT patent publication WO97/24981, which is incorporated herein by reference. The one or more physiological parameters may be either scalars or vectors and may comprise, for example, a voltage, temperature, pressure, impedance, conduction velocity, or any other desired value.
It is noted that the physiological response is a time of arrival of a physiological signal propagating in the biological structure and the vector function may be any of a number of vector functions (as noted above). For example, the vector function may be a conduction velocity of the electrical activity.
Preferably, after the volume is reconstructed based on the coordinates, values of the physiological parameter are determined for each of the grid points based on interpolation of the parameter value at surrounding sampled points. Preferably, the interpolation of the physiological parameter is performed in a manner proportional to the aggregate interpolation of the coordinates. Alternatively, the physiological parameters are interpolated according to the geometrical distance between the points on the grid. Alternatively or additionally, the physiological parameters are interpolated in a manner similar to the flexible matching step described hereinabove.
The reconstructed surface may be displayed in movement, and/or a physician may request a display of a specific time point of the cycle. Preferably, the physiological parameter is displayed on the reconstructed surface based on a predefined color scale. In a preferred embodiment of the present invention, the reliability of reconstruction of regions of the reconstructed surface is indicated on the displayed surface. Preferably, regions which are beneath a user-defined threshold are displayed as semi-transparent, using α-blending. Preferably, the reliability at any grid point is determined according to its proximity to sampled points. Those points on the grid which are beyond a predetermined distance from the nearest sampled point are less reliable.
In some preferred embodiments of the present invention, acquired images such as LV-grams and fluoroscopic images are used together with the sampled points to enhance the speed and/or accuracy of the reconstruction. Preferably, the processor performs an object recognition procedure on the image to determine the shape of the closed 3D curved surface to use in constructing the initial grid of the reconstruction. Alternatively or additionally, the image is used by the physician to select areas in which it is most desired to receive sampled points.
In some preferred embodiments of the present invention, the physician may define points, lines, or areas on the grid which must remain fixed and are not to be adjusted. Alternatively or additionally, some points may be acquired as interior points which are not to be on the map since they are not on a surface of the volume. The reconstruction procedure is performed accordingly so that the closed curve is not moved too close to the interior points.
In some preferred embodiments of the present invention, the reconstruction surface is used to determine an accurate estimate of the volume of the cavity. The surface is divided by the grid points into quadrilaterals, and each quadrilateral is further divided into two triangles. Based on these triangles the volume defined by the surface is estimated. Alternatively, the volume is calculated using a volumetric representation. Other measurements, such as geodesic surface measurements on the surface, may also be performed using the reconstructed surface.
It is noted that some of the stages described above may be ignored in some preferred embodiments of the invention, in order to save processing time and speed up the reconstruction procedure.
One example of a physiological parameter to which the present invention is particularly applicable is the local activation time (LAT) of heart tissue. The present invention allows the measurement of LAT, relative to the cardiac cycle, at a plurality of sampled points on the inner surface of a chamber of the heart, using a device, at the tip of a catheter, that senses electrical activity only at a single point of contact of the catheter tip with the inner surface of the chamber of the heart. These measurements of LAT are posted at corresponding points on a grid that corresponds to a particular time in the cardiac cycle, preferably end diastole, and are interpolated to the other grid points. The grid points define polygons, for example, triangles; and a vectorial propagation velocity is determined for each grid polygon from the LAT values at the grid points that are the vertices of the polygon. Each grid then is assigned the average of the propagation velocities of the polygon of which it is a vertex, and the propagation velocities at the grids are smoothed and displayed, preferably as arrows posted at the grid points, with the directions of the arrows representing the direction of propagation and the lengths of the arrows representing the speed of propagation. These arrows provide a visual display of propagation speed and propagation vorticity that enables an electrophysiologist to identify the location of diseased cardiac tissue that should be treated. Note that this measurement and display of propagation velocity is based on consecutive measurements at individual points on the inner surface of the chamber of the heart, unlike the prior art methods, which require simultaneous measurements at at least two distinctly separated points.
More generally, such a display may be constructed for any vector function that is related to a physiological response measured at discrete points on the surface of a biological structure. The vector function may be any of a number of vector functions. For example, the vector function may be a conduction velocity of the physiological response.
LAT is the time interval between a reference time determined, for example, from the body surface ECG or intracardiac electrogram, and the time of the local depolarization event. Other useful scalar functions of the physiological parameters, may be calculated and displayed, superposed on a combined display of LAT (as pseudocolor) and propagation velocity (as arrows). One such useful scalar function is the range of voltages measured at each sampled point (displayed as a pseudocolor): an abnormally low range is diagnostic of scar tissue, upon which the conduction velocity may be displayed as arrows.
There is therefore provided in accordance with a preferred embodiment of the present invention, a method of reconstructing a map of a volume, including determining coordinates of a plurality of locations on a surface of the volume having a configuration, generating a grid of points defining a reconstruction surface in 3D space in proximity to the determined locations, for each of the points on the grid, defining a respective vector, dependent on a displacement between one or more of the points on the grid and one or more of the locations, and adjusting the reconstruction surface by moving substantially each of the points on the grid responsive to the respective vector, so that the reconstruction surface is deformed to resemble the configuration of the surface.
Preferably, the method includes displaying the reconstruction surface.
Preferably, generating the grid includes generating a grid such that the reconstruction surface encompasses substantially all of the determined locations or is interior to substantially all of the determined locations.
Preferably, generating the grid includes defining an ellipsoid.
Preferably, the reconstruction surface is defined and adjusted substantially independently of any assumption regarding a topology of the volume.
Further preferably, the reconstruction surface is defined and adjusted substantially without reference to any point within the volume.
Alternatively or additionally, generating the grid includes acquiring an image of the volume and defining the reconstruction surface such that it resembles the image of the volume.
Further alternatively or additionally, generating the grid includes choosing a grid from a memory library according to at least one characteristic of the volume.
Preferably, adjusting the surface includes a rough adjustment stage and a flexible matching stage.
Preferably, the rough adjustment stage includes moving each point on the grid toward a respective weighted center of mass of the determined locations, and locations closer to the point on the grid are given larger weight.
Preferably, moving each point in the rough adjustment stage includes defining, for each of the points on the grid, a respective rough adjustment vector which includes a weighted sum of vectors from the point to each of the determined locations and moving the points a distance proportional to the respective vector.
Preferably, defining the rough adjustment vector includes calculating a weight for each of the summed vectors that is generally inversely proportional to a magnitude of the summed vector raised to a predetermined power.
Preferably, the weight includes an inverse of a sum of a constant and the magnitude of the vector raised to a power between 4 and 10.
Preferably, the constant is smaller than a precision of the location determination.
Preferably, moving each point includes moving each point toward a respective target point by a distance between 50 and 90% of the distance between the point and the target point.
Preferably, the flexible matching stage includes selecting a grid point to be associated respectively with each of the determined locations.
Preferably, selecting the grid point includes finding for each determined location a point on the grid that is substantially closest thereto.
Further preferably, the flexible matching stage includes moving the selected grid points toward their respective determined locations.
Preferably, moving the selected grid points includes moving the grid points substantially onto their respective, determined locations.
Preferably, the flexible matching stage includes moving grid points that were not selected by an amount dependent on the movements of surrounding grid points.
Preferably, moving the grid points that were not selected includes moving the grid points by an amount dependent substantially only on the movements of surrounding selected grid points.
Preferably, moving the grid points includes calculating a movement of a grid point that was not selected based on the movements of the surrounding selected grid points and distances from these surrounding grid points.
Preferably, calculating the movement of the grid point includes interpolating between the movements of surrounding grid points.
Preferably, the distances include geometrical distances.
Alternatively or additionally, the distances include a length of the reconstruction surface between the grid points.
Preferably, the flexible matching stage includes defining a displacement function which includes a weighted sum of vectors, each vector connecting a location and its associated point.
Preferably, the flexible matching stage includes moving the grid points according to the displacement function so as to smooth the surface.
Preferably, determining the coordinates includes positioning a catheter tip at the plurality of locations.
Preferably, positioning the catheter tip includes positioning the catheter at a plurality of locations in a chamber of the heart.
Preferably, determining the coordinates includes positioning a catheter tip at the plurality of locations.
Preferably, determining the coordinates includes transmitting and receiving non-ionizing waves.
Preferably, determining the coordinates includes positioning at the plurality of locations a device which generates signals indicative of the position of the device.
Preferably, the device generates signals indicative of the six degrees of position and orientation of the device.
Preferably, determining the coordinates includes receiving the coordinates from an external source.
Preferably, the method includes acquiring a signal indicative of a value of physiological activity at substantially each of the plurality of locations.
Preferably, acquiring the signal includes acquiring a signal indicative of a value of electrical activity at the location.
Preferably, the method includes estimating a value of the physiological activity at the adjusted grid points.
Preferably, estimating the value of the physiological activity includes estimating based on an acquired value of the physiological activity at a location in a vicinity of the adjusted grid points.
Preferably, estimating based on the acquired value includes interpolating the value responsive to deformation of the reconstruction surface.
Preferably, determining coordinates of a plurality of locations includes determining coordinates of less than 200 locations, more preferably of less than 50 locations, and most preferably of less than 20 locations.
Preferably, the volume is in motion, and determining the coordinates includes determining a correction factor responsive to the motion.
Preferably, the motion includes cyclic motion, and determining the correction factor includes determining a factor responsive to a cycle frequency of the motion.
Preferably, determining the factor includes filtering out motion at a frequency substantially different from the cycle frequency.
Preferably, the motion includes cyclic motion, and determining the coordinates includes determining the coordinates at a predetermined phase of the cyclic motion.
Preferably, determining the coordinates at the predetermined phase includes determining the coordinates in a plurality of time points and adjusting the coordinates relative to the cyclic movement.
Preferably, adjusting the coordinates includes determining a rate of the cyclic movement together with the coordinates for substantially each coordinate determination.
Preferably, generating the grid and adjusting the reconstruction surface are performed separately with respect to the coordinates determined in each phase of the cyclic motion.
Alternatively or additionally, generating and adjusting are performed for the coordinates of a plurality of phases of the cyclic motion so as to form a motion map of the volume.
Preferably, generating the grid and adjusting the reconstruction surface are performed for a first group of coordinates determined in a first phase of the cyclic motion, and the reconstructed surface of the first group is adjusted to form a reconstructed surface in one or more additional phases.
Preferably, the method includes smoothing the reconstructed surface.
Preferably, the method includes applying an affine transformation to the reconstructed surface.
Preferably, the method includes a final stage in which each determined location is associated with a respective grid point, and the associated grid points are moved onto the determined locations while non-associated grid points are substantially not moved.
Preferably, the method includes estimating a measure of the volume responsive to the reconstructed surface.
Preferably, estimating the measure of the volume includes choosing an arbitrary point inside the grid and calculating the volumes of tetrahedrons defined by the arbitrary point and groups of three points on the grid which cover the entire grid surface.
There is further provided in accordance with a preferred embodiment of the present invention, apparatus for reconstructing a map of a volume from coordinates of a plurality of determined locations on a surface of the volume having a configuration, including a processor, which receives the coordinates and generates a grid of points defining a reconstruction surface in 3D space in proximity to the determined locations, and which defines a respective vector for each of the points on the grid, dependent on a displacement between one or more of the points on the grid and one or more of the locations, and which adjusts the reconstruction surface by moving each of the points on the grid responsive to the respective vector, so that the reconstruction surface is deformed to resemble the configuration of the surface of the volume.
Preferably, the apparatus includes a display screen for displaying the adjusted surface.
Preferably, the processor analyzes the adjusted surface to determine a characteristic of the volume.
Preferably, the apparatus includes a memory for storing the adjusted surface.
Preferably, the grid initially encompasses substantially all of the determined locations.
Preferably, the apparatus includes an imaging device for acquiring an image of the volume, and the processor defines the grid initially such that it resembles the image of the volume.
Preferably, the apparatus includes a memory library including a plurality of closed curves, and the processor defines the grid initially by choosing a closed curve from the memory library according to at least one characteristic of the volume.
Preferably, the processor generates and defines the reconstruction surface substantially independently of any assumption regarding a topology of the volume.
Preferably, the processor generates and defines the reconstruction surface substantially without reference to any point within the volume.
Preferably, the processor forms the adjusted grid in two stages: a rough adjustment stage and a flexible matching stage.
Preferably, in the rough adjustment stage, the processor moves each point on the grid toward a respective weighted center of mass of the determined locations, and locations closer to the point on the grid are given larger weight.
Preferably, the processor calculates the center of mass using a weight that is substantially proportional for each location to the inverse of the sum of a small constant and the distance between the point and the location raised to a power between 4 and 10.
Preferably, the constant is smaller than a precision of the location determination.
Preferably, in the flexible matching stage, the processor selects a respective grid point to associate with each of the determined locations.
Preferably, the selected grid point for each determined location includes a point on the grid that is closest to the location.
Preferably, in the flexible matching stage, the processor moves the selected grid points toward their respective, associated locations.
Preferably, the processor moves the selected grid points onto the associated locations.
Preferably, the processor moves non-selected grid points by an amount dependent on the movements of surrounding grid points.
Preferably, the amount of movement of the non-selected grid points is dependent on the movements of surrounding selected grid points.
Preferably, the amount of movement of each of non-selected grid points is calculated by the processor based on the distances from the surrounding selected grid points to the non-selected grid point.
Preferably, the amount of movement of the non-associated grid points is calculated by the processor based on an interpolation of the movements of surrounding selected grid points.
Preferably, the distances include geometrical distances.
Preferably, the apparatus includes a probe, which is brought into engagement with the surface to determine the locations thereon.
Further preferably, the probe includes a position sensor which indicates the position of a tip of the probe.
Preferably, the sensor includes at least one coil.
Preferably, the sensor generates signals indicative of position and orientation of the sensor.
Alternatively or additionally, the probe includes a functional portion for acquiring a value of a physiological activity at the plurality of locations.
Preferably, the functional portion includes an electrode.
Preferably, the processor estimates a value of the physiological activity at the adjusted grid points.
Preferably, the processor estimates the value of the physiological activity based on the acquired values of the physiological activity at points surrounding the adjusted grid points.
Preferably, the processor estimates the value by interpolation from the acquired values responsive to deformation of the reconstruction surface.
Preferably, the apparatus includes a reference catheter for registering the determined locations relative to a frame of reference associated with the volume.
Preferably, the apparatus includes an ECG monitor for gating the operation of the probe so as to determine the points at a fixed phase of a cyclic movement of the volume.
There is further provided in accordance with a preferred embodiment of the present invention, a method of displaying values of a parameter which varies over a surface, including determining a value of the parameter at each of a plurality of points on the surface, and rendering an image of the surface to a display with a different degree of transparency in different areas of the surface, responsive in each of the areas to the value of the parameter at one or more points in the area.
Preferably, determining the value includes sampling a plurality of points and creating a map of the surface responsive thereto, and rendering the image includes rendering a graphic representation of the map.
Preferably, creating the map includes creating a three-dimensional map.
Preferably, determining the value includes determining a measure of reliability of the map in each of the areas.
Preferably, rendering the image includes rending one or more of the areas having a low measure of reliability relative to another one or more of the areas with a relatively greater degree of transparency.
Preferably, determining the measure of reliability includes determining a density of the sampled points.
Preferably, rendering the image includes defining a color scale and displaying a color associated with the value, at each of the plurality of points.
Preferably, the plurality of points includes sampled points and interpolated points, and determining the measure of reliability includes assigning a high reliability measure to the sampled points.
Preferably, determining the measure of reliability includes assigning measures of reliability to the interpolated points according to their respective distance from a closest sampled point.
There is further provided in accordance with a preferred embodiment of the present invention, a method of diagnosing a condition in a biological structure, including measuring a physiological response at at least three sampled points on a surface of the biological structure, calculating a vector function related to the response, and displaying a representation of the vector function.
Preferably, the vector function is related to a gradient of the physiological response.
Preferably, the physiological response is a function of time.
More preferably, the physiological response is a time of arrival of a physiological signal propagating in the biological structure, and the vector function may be any of a number of vector functions, most preferably it is a conduction velocity.
Preferably, the representation includes an arrow at each sampled point, the length of the arrow being related to the magnitude of the vector function at each sampled point, and the direction of the arrow being related to the direction of the vector function at each sampled point.
Preferably the method further includes fitting a surface to the sampled points and displaying the surface, the display of the representation being superposed on the display of the surface. Here, too, it is preferred that the representation includes an arrow at each sampled point, the length of the arrow being related to the magnitude of the vector function at each sampled point, and the direction of the arrow being related to the direction of the vector function at each sampled point.
Preferably, the fitting of the surface to the sampled points includes representing the surface as a grid that includes at least as many grid points as there are sampled points. More preferably, at least one of the grid points coincides with one of the sampled points.
Preferably, the grid includes a plurality of polygons, with the grid points being the vertices of the polygons, each grid point being a vertex of at least one polygon, and the calculating of the vector function includes the steps of interpolating the response at the grid points, assigning a value of the vector function to each polygon, with the value of the vector function assigned each polygon being based on the interpolated response at the grid points that are the vertices of that polygon, and determining a value of the vector function at each grid point, with the value of the vector function at each grid point being based on the values of the vector function that are assigned to the polygons of which that grid point is a vertex. Most preferably, the polygons are triangles.
More preferably, calculating the vector function further includes smoothing the values of the vector function at the grid points. Most preferably, the smoothing parameters may be determined based on a priori knowledge about the specific heart.
Preferably, the method further includes calculating scalar functions related to the physiological response and displaying representations of these scalar functions superposed on the display of the surface along with the representation of the vector function. An important example of one such scalar function is a range of the physiological response measurements at the sampled points. In another important example, useful in the diagnosis of heart disease, the measurements are voltage measurements, a scalar function is the range of voltage measurements at each sampled point, and the vector function is a conduction velocity inferred from the local activation time.
Preferably, the physiological response is an impedance, wherein the scalar function is a range of the impedances, and the vector function is a conduction velocity.
Preferably, the method further includes inferring the condition from the representation of the vector function. Preferably, inferring the condition includes identifying at least one location on the surface that is afflicted by the condition, and the method further includes the step of treating those locations.
Preferably, the treatment includes ablation of the biological structure at those locations.
Preferably, the physiological response is measured consecutively at the sampled points.
There is further provided, in accordance with a preferred embodiment of the present invention, a method of diagnosing a condition in a biological structure, including measuring a physiological response at at least three sampled points on a surface of the biological structure, calculating a vector function related to the response, and inferring the condition from the vector function.
Preferably, the vector function is related to a gradient of the physiological response.
Preferably, the physiological response is a function of time.
More preferably, the physiological response is a time of arrival of a physiological signal propagating in the biological structure, and the vector function is a velocity of the propagation.
Preferably, inferring the condition includes identifying at least one location on the surface that is afflicted by the condition, and the method further includes the step of treating those locations.
Preferably, the treatment includes ablation of the biological structure at those locations.
Preferably, the physiological response is measured consecutively at the sampled points.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic, perspective view of a heart mapping system, in accordance with a preferred embodiment of the present invention;
FIG. 2 shows a mapping catheter within a heart of a patient, in accordance with a preferred embodiment of the present invention;
FIG. 3 is a flow chart illustrating a method of point sampling and map reconstruction, in accordance with a preferred embodiment of the present invention;
FIG. 4 is a flow chart illustrating a reconstruction procedure, in accordance with a preferred embodiment of the present invention;
FIGS. 5A-5E are simplified, two dimensional graphs illustrating reconstruction of a map from sampled points, in accordance with a preferred embodiment of the present invention;
FIG. 6 is a schematic illustration of a displayed reconstructed heart volume, in accordance with a preferred embodiment of the present invention;
FIG. 7 is an illustration of a volume estimation method, in accordance with another preferred embodiment of the present invention;
FIG. 8 is an illustration of a reconstruction procedure, in accordance with another preferred embodiment of the present invention;
FIG. 9 shows a planar wavefront crossing a grid triangle;
FIG. 10 shows a combined LAT—conduction velocity display for a normal human atrium;
FIG. 11 shows a combined LAT—conduction velocity display for a human atrium suffering from atrial flutter;
FIG. 12 shows a pattern, on a combined voltage range—conduction velocity plot, that is diagnostic of ventricular tachycardia for a human ventricle;
FIG. 13 shows a conduction velocity display in the left ventricle of a dog wherein the heart is entrained in a sinus rhythm from the right ventricle apex; and
FIG. 14 shows a conduction velocity display of the right atrium of a human heart suffering from atrial flutter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a mapping system 18 for mapping of a volume in a patient's body, in accordance with a preferred embodiment of the present invention. System 18 comprises an elongate probe, preferably a catheter 20 , for insertion into the human body. A distal end 22 of catheter 20 includes a functional portion 24 for performing diagnostic and/or therapeutic functions, adjacent to a distal tip 26 . Functional portion 24 preferably comprises electrodes (not shown in the figure) for performing electrophysiological measurements, as described, for example, in U.S. Pat. No. 5,391,199 or in PCT publication WO97/24983, which are incorporated herein by reference. Alternatively or additionally, functional portion 24 may include other diagnostic apparatus for recording parameter values at points within the body. Such apparatus may include a chemical sensor, a temperature sensor, a pressure sensor and/or any other desired sensor. Functional portion 24 may determine for each point a single value of the parameter, or alternatively a plurality of values dependent on the time of their acquisition. Functional portion 24 may also include therapeutic apparatus, as is known in the art.
Distal end 22 of catheter 20 further includes a device 28 that generates signals used to determine the position and, preferably, orientation of the catheter within the body. Device 28 is preferably adjacent to functional portion 24 , in a fixed relation with tip 26 . Device 28 preferably comprises three non-concentric coils, such as described in PCT patent publication WO96/05768, whose disclosure is incorporated herein by reference. This device enables continuous generation of six dimensions of position and orientation information with respect to an externally-applied magnetic field. Alternatively, device 28 comprises other position and/or coordinate sensors as described in U.S. Pat. No. 5,391,199, U.S. Pat. No. 5,443,489 and PCT publication WO94/04938, which are incorporated herein by reference. Further alternatively or additionally, tip 26 is marked with a marker whose position can be determined from outside of the body, for example, a radio-opaque marker for use with a fluoroscope.
Catheter 20 preferably includes a handle 30 , having controls 32 which are used by a surgeon to steer distal end 22 of the catheter in a desired direction, so as to position and/or orient it as desired. Catheter 20 preferably comprises a steering mechanism in distal end 22 , as is known in the art, so that repositioning of tip 26 is facilitated.
Catheter 20 is coupled, via an extension cable 21 , to a console 34 which enables the user to observe and regulate the functions of catheter 20 . Console 34 preferably includes a computer 36 , keyboard 38 , signal processing circuits 40 , which are typically inside the computer, and display 42 . Signal processing circuits 40 typically receive, amplify, filter and digitize signals from catheter 20 , including signals generated by position signal generating device 28 , whereupon these digitized signals are received and used by computer 36 to compute the position and orientation of the catheter. Alternatively, appropriate circuitry may be associated with the catheter itself so that circuits 40 receive signals that are already amplified, filtered and/or digitized. Preferably, computer 36 includes a memory for storing positions and determined parameters of the points. Computer 36 preferably also includes dedicated graphic hardware for polygon manipulation, which allows performing reconstruction stages described hereinbelow using fast computer graphic techniques.
Preferably, system 18 also includes an ECG monitor 73 , coupled to receive signals from one or more body surface electrodes 52 and to convey the signals to computer 36 . Alternatively, the ECG monitoring function may be performed by circuits 40 .
FIG. 2 shows a distal portion of mapping catheter 20 within a heart 70 of a patient, in accordance with a preferred embodiment of the present invention. Catheter 20 is inserted into heart 70 and tip 26 is brought into contact with a plurality of locations, such as locations 75 and 77 on an inner surface 72 of heart 70 . Surface 72 bounds the volume to be reconstructed, and it is locations on this surface which are to be sampled. At each of the plurality of locations, the coordinates of tip 26 are determined by device 28 , preferably together with physiological information determined by functional portion 24 . The determined coordinates and, optionally, physiological information form a local data point. The local data points from a plurality of locations are used for producing a map of heart 70 , or of a portion of the heart.
At least one reference catheter 78 is preferably inserted into heart 70 and is placed in a fixed position relative to the heart. By comparing the positions of catheters 20 and 78 , the position of tip 26 is accurately determined relative to the heart, irrespective of heart motion. Alternatively, any other suitable method may be used to compensate for movement of heart 70 .
Preferably, the coordinates of tip 26 at the plurality of locations are determined at a common time-point in the cardiac cycle, preferably at end-diastole. Alternatively or additionally, each determined position is recorded together with a time-point, preferably relative to a predetermined time-point in the cardiac cycle, and together with indication of the current heart rate. The relative time-point and the rate of the cycle are used to correct for the movement of the heart. Thus, it is possible to determine positions of a large number of points, simply, in a limited time period.
Further alternatively or additionally, the position of tip 26 is determined at each location at two or more time-points in the cardiac cycle, such that for each location, a range of positions are determined. Thus, a geometric map of the plurality of locations may comprise a plurality of “snapshots” of heart 70 , each snapshot associated with a different phase of the cardiac cycle. The cardiac cycle is preferably determined using ECG monitor 73 , according to physiological readings from functional portion 24 , or according to movements of reference catheter 78 . Preferably, each position is determined together with the heart rate at the time of determination. A frequency and phase shift transformation is preferably applied to the plurality of positions at each location to bring the positions to a state as if they were determined at common time-points with respect to a common predetermined heart rate.
Preferably, the transformation applied to the positions also serves to reduce or eliminate the effects of any movement of the heart that is not due to the cardiac cycle, particularly chest movement due to respiration or other movements of the patient. These effects are removed by defining a cyclic trajectory of the points associated with each location, and then filtering out of the trajectory frequencies of motion other than frequencies associated with the heart rate. Preferably, any frequencies whose corresponding wavelengths do not evenly divide the cardiac cycle length, as determined from the ECG, are filtered out. The result for each location is a modified trajectory, including a corrected end-diastolic point, which is then used in reconstructing the map of the heart, as described hereinbelow.
Preferably, at each location at which tip 26 is positioned, it is verified that catheter 20 is in contact with the surface, using any suitable method, for example, as described in PCT publication WO97/24981, which is incorporated herein by reference.
FIG. 3 is a flow chart illustrating the process of point sampling and reconstruction of a map, in accordance with a preferred embodiment of the present invention. As described above, catheter 20 is brought into contact with surface 72 of heart 70 , and signals are received from the catheter to form a local data point characteristic of the location of tip 26 . The local data point preferably includes coordinates of the point at a plurality of time points and one or more values, associated with the point, of at least one physiological parameter. Preferably, as mentioned above, the local data point includes an indication of the heart rate and time point in the heart cycle for each determined coordinate. The parameter values may be associated with specific time points or may be associated generally with the point.
Preferably, the contact between tip 26 and surface 72 is verified and the point is added to the map only if there is sufficient contact between the tip and the surface. In a preferred embodiment of the present invention, points for which proper contact does not exist are added to a database of interior points. These points are interior to the reconstructed surface and indicate areas on the map which are not part of the reconstructed surface. Alternatively or additionally, the user may indicate sampled points which are not to be used as part of the reconstructed surface, for example because they are outstandingly outside of the area of the other sampled points. Tip 26 is then moved to an additional location on surface 72 and data are likewise determined regarding the additional point. This procedure is repeated for a plurality of sampled points until data are determined for a sufficient number of points to make the map, or for a predetermined amount of time. Preferably, computer 36 counts the number of sampled points and compares the number of points to a predetermined required minimum number of points. Preferably, the predetermined number of points is between about ten to twenty points for fast procedures and is up to 100 points for longer procedures. Alternatively or additionally, the physician notifies computer 36 when a sufficient number of points have been sampled.
A map of heart 70 or of a volume within the heart is reconstructed, as described below, and the physician decides whether the map includes sufficient detail and appears to be accurate. If the map is not sufficient, more points are acquired and the map is accordingly updated or is again reconstructed. The reconstructed map is thereafter used for analysis of the functioning of heart 70 , and the physician may decide on a required treatment accordingly.
FIG. 4 is a flow chart illustrating a reconstruction procedure, in accordance with a preferred embodiment of the present invention. Reconstruction is initially performed for positions determined at an anchor time point (t 0 ) of the heart cycle, such as end diastole. In a first stage of the initial reconstruction, a grid enclosing the sampled points is constructed. Thereafter, a stage of model distortion is applied to the grid, in which the grid is roughly adjusted to the shape defined by the sampled points. Subsequently, a preferably iterative stage of flexible matching is carried out finely adjusting the grid points according to the coordinates of the sampled points. Final adjustment is preferably applied to the grid including smoothing, an affine transformation and/or an exact matching stage which brings the grid to include substantially all the sampled points. The parameter values associated with the sampled points are preferably interpolated to all the grid points and the grid is subsequently displayed. This procedure is described in greater detail hereinbelow with reference to the figures that follow.
FIGS. 5A-5E are simplified, two-dimensional graphs illustrating the reconstruction procedure for a single time-point, in accordance with a preferred embodiment of the present invention. For clarity of illustration, the figures and the following description refer to a simplified, two dimensional example. The extension of the principles illustrated herein to 3D reconstruction will be clear to those skilled in the art. Points S i are sampled points on the surface of the volume to be reconstructed, whose coordinates were received during the above-described sampling process.
As shown in FIG. 5A, in the first stage, an initial grid 90 is defined in a vicinity of the sampled points, preferably enclosing the sampled points. Alternatively, grid 90 may be interior to the sampled points or pass between the points. Preferably, grid 90 comprises a number of points substantially greater than the number of sampled points. The density of the points is preferably sufficient to produce a map of sufficient accuracy for any required medical procedure. In a preferred embodiment of the present invention, the physician can adjust the density of points on the grid according to a desired compromise between reconstruction speed and accuracy. Preferably, grid 90 has an ellipsoidal shape or any other simple closed shape.
Alternatively or additionally, grid 90 has a shape based on known characteristics of the volume on whose surface the sampled points are located, for example, a shape determined by processing an LV-gram or other fluoroscopic or ultrasound image of the heart. In a preferred embodiment of the present invention, computer 36 contains a data-base of initial grids according to commonly-sampled volumes. The physician indicates, preferably via keyboard 38 , which volume is being sampled and initial grid 90 is chosen accordingly. The chosen grid may be initially aligned with the sample points using any method known in the art, for example as described in Paul J. Besl and Neil D. McKay, “A method for registration of 3-D shapes,” IEEE Transactions on Pattern Analysis and Machine Intelligence, 14(2):239-258, February 1992, which is incorporated herein by reference. The initial grid may alternatively be chosen from the grid library using geometric hashing or alignment, as described, for example, in Haim J. Wolfson, “Model-based object recognition by geometric hashing,” in: O. Faugeras, ed., Computer Vision-ECCV90 (First European Conference on Computer Vision, Antibes, France, Apr. 23-27, 1990), Springer, Berlin, 1990, 526-536, or in P. Huttenlocher and S. Ullman, “Recognizing solid objects by alignment with an image,” International Journal of Computer Vision, 5: 195-212, 1990, which are incorporated herein by reference. After the initial alignment, the method of the present invention proceeds, preferably as shown in FIG. 4 and described further hereinbelow.
As shown in FIG. 5B, grid 90 is transformed to a grid 92 of points G′, which is a rough adjustment toward the structure of the sampled volume. For each point Gj on grid 90 , an adjustment vector {right arrow over (V)} j is constructed, and point Gj is replaced by a corresponding point Gj′ on grid 92 , which is displaced by {right arrow over (V)} j from point Gj on grid 90 . Adjustment vector {right arrow over (V)} j is preferably a weighted sum of vectors {right arrow over (V)} ji from Gj to the sampled points S i , as shown in FIG. 5 A. Preferably, the weights of vectors {right arrow over (V)} ji in the sum are strongly inversely dependent on the magnitude of the vectors. Preferably, the weights are inversely dependent on the magnitude raised to a power (k), wherein k preferably ranges between 4 and 10, and is most preferably either between 6 and 8. In a preferred embodiment of the present invention, adjustment vectors {right arrow over (V)} j are calculated according to equation (1): V → j = C f ∑ i V → ij r j k + ɛ ÷ ∑ 1 r j k + ɛ , r j = V → ij ( 1 )
In equation (1), epsilon is a small scalar, preferably, smaller than the magnitude of the smallest vector which is not zero, and is preferably of the size of the accuracy of the determination of the sampled points, for example, about 10 −6 . Epsilon is used to prevent division by zero when the grid point is on a sampled point, and therefore the magnitude of the vector is zero. Cf is a constant factor between 0.1 and 1, preferably between 0.5 and 0.9 most preferably about 0.75, which is adjusted to determine how closely the points G j ′ will approach points S i in the rough adjustment.
In a preferred embodiment, the influence of a sampled point Si on grid point Gj, takes into account not only the distance between the sampled point Si and Gj, as shown above in equation (1) but also the density of sampled points S in the vicinity of Si. Hence, the weighting factor applied to each sampled point, 1 r j k + ɛ ,
is multiplied by a density value δ i , which preferably takes on values between 0 and 1. Preferably, δ i is as defined in equation (2): δ i = 1 ∑ j 1 ( S j - S i 2 + 1 ) ( 2 )
The more points there are in the vicinity of S, the smaller value δ takes on and the less influence each point has. Preferably, the sum of influences of a plurality of points in a close vicinity is the same as the influence of a single isolated point, which preferably has a density value δ of about 1.
FIG. 5C illustrates a first part of a flexible matching step, in which each of sampled points S i is associated with a grid point Gj from roughly adjusted grid 92 . The associated grid points are moved toward their respective sampled points, while the rest of the G′ points on the roughly adjusted grid are moved according to interpolation of the movements of neighboring points on grid 92 , as described further hereinbelow. Preferably, each sampled point S i is associated with the closest grid point. For example, the closest grid point to S 1 is G 1 ′, and these points are therefore associated. Preferably, computer 36 creates a memory list in which these pairs of points are listed. For clarity of this explanation, the associated points are marked by dashed ovals 96 in FIG. 5 C.
Preferably, a transformation function f, which moves the associated grid points toward their respective sampled points, is generated. The non-associated grid points are also moved according to function f. Function f is preferably easily calculated, and transforms the grid to a smooth form. Preferably, function f is a weighted sum of the distances between the associated pairs of sampled and grid points, such that pairs of associated points close to the grid point influence its displacement more than pairs of associated points far from the grid point. Function f is preferably as given in equation (3) below, with w i (Gj) dependent on the distances between the grid point Gj and the associated grid points Gi, preferably as defined in equation (4). Alternatively, w i (Gj) is dependent on the distance between the grid point Gj and the sampled points Si, as in equation (1). In the flexible matching stage, k is preferably smaller than the power law in the rough adjustment stage in order to generate a smoother grid surface. Preferably, k in the flexible matching stage is between 2 and 6 and is most preferably 4. Preferably, k is an even number in order to simplify the calculations. Although the equations below are stated for convenience in scalar notation, it will be understood that S i , G i and f(Gj) are vector quantities, as in equation (1) above: f → ( G j ) = ∑ i w i ( G j ) · ( S i - G i ) ∑ w i ( Gj ) ( 3 ) w i ( G j ) = 1 G j - S i k + C C > 0 ( 4 )
The constant C determines how close the associated grid points are moved toward their associated sampled points. For very small values of C, the associated grid points G i are moved substantially onto the sampled points S i . Preferably, C is between 0.3 and 0.7, more preferably about 0.5. Alternatively or additionally, C is changed according to the number of times the flexible matching is to be performed. Further alternatively or additionally, in the first flexible matching step, C is relatively large, while in subsequent flexible matching steps C is gradually reduced.
The distance definition used in equations (2), (3) and (4) is preferably the Euclidean distance in R 3 , due to its simplicity in calculation and the fact that it causes points on opposite walls of the reconstructed volume to repel one another.
In an alternative preferred embodiment of the present invention, the grid points which have an associated sampled point are moved toward their associated sampled points by a portion of the distance between them. Preferably, the points are moved a percentage of the distance between the associated pair. For example, in FIG. 5C the points are moved about ⅔ of the distance. Alternatively, the grid points are moved by any other amount dependent on the distance between the associated pair.
As shown in FIG. 5D, those grid points G′k which are not associated with sampled points S i are then moved according to a movement vector {right arrow over (V)}′ k which is dependent on the movements of the grid points G′ 1 surrounding the point. Preferably, the non-associated points G′ k are moved a distance which is a linear interpolation of the movements of the surrounding points G′ 1 . Preferably, the distance between the grid points is determined as the geometrical distance between the points as they are on the present adjusted grid. For example, the geometrical distance between G′ 15 and G′ 16 is indicated by X 2 , and may be calculated according to the coordinates of the two points. Alternatively or additionally, the distance used is the grid-distance {tilde over (X)} 2 along the present adjusted grid, the grid-distance {tilde over (L)} 2 along the original grid, or the geometrical distance L 2 on the original grid. In a preferred embodiment of the present invention, in a first flexible matching step, the distance used is the grid-distance—either l 2 or {tilde over (X)} 2 —while in subsequent flexible matching steps the distance used is the geometrical distance X 2 .
For example, as shown in FIG. 5D, point G′ 15 is moved a distance defined by a vector, which is a weighted sum of vectors {right arrow over (V)} 14 , and {right arrow over (V)} 16 of grid points G′ 14 , and G′ 16 , respectively. Preferably, {right arrow over (V)} 15 is as described in equation (2) below, in which d 1 is a selected type of distance between G 15 and G 14 , and may include X 1 , {tilde over (X)} 1 , l 1 or any other suitable distance definition. Likewise, d 2 is a selected type of distance between G 15 and G 16 and may include X 2 , {tilde over (X)} 2 , l 2 , or any other distance definition. Preferably, in the first flexible matching step illustrated in FIG. 5D, d 1 and d 2 are taken as X 1 and X 2 respectively. V → 15 ′ = d 2 d 1 + d 2 V → 14 ′ + d 1 d 1 + d 2 V → 16 ′ ( 5 )
Although equation (8) illustrates a first-order linear interpolation, it will be understood that higher-order and non-linear interpolation methods may also be used.
Preferably, during the flexible matching stage, flexible matching steps are repeated a few times (N 0 times, as shown in FIG. 4 ). Each time, grid points are associated with the sampled points, and the associated and non-associated grid points are moved accordingly.
The rough adjustment and flexible matching tend to cause the grid to become non-uniform. Therefore, during a final adjustment stage the grid is preferably smoothed, for example, by applying a surface convolution with a Gaussian-like kernel. Preferably, the kernel is a 3×3 Gaussian kernel, and is applied to the grid a plurality of times, preferably between five and ten times. Alternatively, a larger kernel may be used in which case it may be applied to the grid fewer times, most preferably only once. The surface convolution, however, generally causes shrinkage of the surface, and therefore a simple transformation, preferably an affine transformation, is applied to the grid to cancel the shrinkage and improve the matching of the grid to the sampled points. The affine transformation is preferably chosen as the transformation which minimizes the mean square distance between sampled points outside of the grid and a surface defined by the grid. This choice of the transformation causes substantially all the sampled points to be on or inside the surface defined by the grid. This choice is in accordance with the anatomical structure of the heart in which outliers, i.e., points not on the sampled surface, are generally inside the sampled surface, i.e. inside a cardiac chamber rather than on the myocardial wall. Thus, the reconstructed grid is properly reconstructed by ignoring outliers which otherwise may deform the grid incorrectly.
To conclude the final adjustment stage, the user may optionally request an exact matching stage in which the grid surface is deformed to include substantially all the sampled points. Preferably, for each sampled point not on the grid surface as a result of prior stages, a closest grid point is chosen and moved to the position of the sampled point. The rest of the grid points are preferably not moved. Preferably, internal points which are beyond a certain distance from the grid surface are not moved in this stage and are regarded as outliers. It is noted that external points are not generally distanced from the grid surface due to the affine transformation described above.
Alternatively or additionally, a last flexible matching step is performed in which the associated grid points are moved onto the sampled points, as shown in FIG. 5 E. Curved line 100 in FIG. 5E represents the final grid configuration and comprises an accurate approximation of the sampled volume.
Alternatively, the flexible matching is performed in one step, and the associated points from the rough adjustment grid are immediately moved onto the sampled points. In a preferred embodiment of the present invention, computer 36 first produces an approximate map, in which the flexible matching is performed in one step. The approximate map is used by the physician to decide if more sampled points are needed. Once the physician decides that no more points are needed, computer 36 reconstructs a more accurate map in which the flexible matching is performed a plurality of times. Meanwhile, the physician may use the approximate map in order to save time. In further preferred embodiments, the first reconstructed map is produced with a relatively low density of points on the grid, while later reconstructions use a more dense grid.
Referring back to FIG. 4, when the sampled points include data from more than one time point, the reconstructed grid of the anchor time point (hereinafter referred to as the anchor grid) is preferably used to quickly reconstruct the grid for other time points t i . For each of the other time points, a simple transformation is performed on the anchor grid to bring the grid close to the form of the sampled points of time t i . The simple transformation is preferably a quadratic transformation or an affine transformation. Alternatively, the transformation comprises a rotation and/or scaling transformation. In some preferred embodiments of the present invention, the transformation is chosen according to the number of sampled points. Preferably, when there are a relatively large number of sampled points, a quadratic transformation is applied, while for fewer sampled points, simpler transformations are employed.
Flexible matching is then preferably performed on the transformed grid one or more times (N T ), preferably fewer times than were required in reconstruction of the anchor-time grid (N T <N 0 ), most preferably twice. Final adjustments are then preferably applied to the grid, and the resulting grid at time t i may be displayed. The parameter value may also be interpolated separately for time t i , substantially as described above with respect to the anchor grid. When reconstruction for all of the time points is concluded, the reconstructed grids may be displayed in sequence as a function of time, or in any other manner. Preferably, the reconstruction process continues while the anchor grid is displayed, so that a physician may use the reconstructed data without delay.
Preferably, as noted hereinabove, each data point includes at least one physiological parameter, such as an indicator of the electrical activity in the heart, measured using functional portion 24 of catheter 20 . After the map is constructed, as described above, the points on the grid, G 1 , G′ 4 , G′ 7 , etc., that were associated with sampled points S 1 , S 2 , S 6 , etc., are assigned the physiological parameter value of their respective sampled points. The non-associated grid points receive parameter values by interpolation between the values of the parameters of neighboring associated grid points in a manner similar to that described above. Alternatively or additionally, the non-associated grid points receive parameter values in a manner similar to the way they received their coordinates in flexible matching.
Further alternatively or additionally, the non-associated grid points are given parameter values using a zero-order-hold filling in method. Starting from the sampled points, all the surrounding grid points are given the same parameter value as the sampled point has, propagating outward until another grid point with a different parameter value is encountered. Thereafter, a Gaussian smoothing process is preferably applied to the parameter values. Thus, parameter values are given in a very simple method to all the grid points substantially without forfeiting visual clarity.
Thus, a 3D map is reconstructed showing both the geometrical shape of the heart chamber and local electrical parameters or other physiological parameters as a function of position in the heart. The local parameters may include electrogram amplitude, activation time, direction and/or amplitude of the electrical conduction vector, or other parameters, and may be displayed using pseudocolor or other means of graphic realization, as is known in the art. Preferably, a predefined color scale is associated with the parameter, setting a first color, e.g., blue, for high values of the parameter, and a second color, e.g., red, for low values of the parameter.
FIG. 6 is a schematic illustration of a displayed reconstructed heart volume 130 , in accordance with a preferred embodiment of the present invention. A plurality of sampled points 134 are used to reconstruct a surface 132 of volume 130 . A grid (not shown) is adjusted as described above to form surface 132 . Preferably, each point on the grid receives a reliability value indicative of the accuracy of the determination. Further preferably, the reliability value is a function of the distance from the grid point to the closest sampled point on surface 132 and/or of a density of sampled points 134 in a vicinity of the grid point. Preferably, areas of surface 132 covered by less-reliable grid points, such as an area 140 , are displayed as semi-transparent, preferably using α-blending. Due to the transparency, points 136 on an inner surface of volume 130 are displayed, being seen through volume 130 . Preferably, the user may define the predetermined distance and/or sample density defining less-reliable points. Alternatively or additionally, different levels of semi-transparency are used together with a multi-level reliability scale.
FIG. 7 is a schematic illustration of a volume estimation method, in accordance with a preferred embodiment of the present invention. In some cases it is desired to estimate the volume encompassed by one or more reconstructed surfaces, for example, to compare the volume of a heart chamber at different time-points of the heart cycle. In FIG. 7 the reconstructed grid surface is represented, for clarity, by a ball 150 . The surface of ball 150 is partitioned into quadrilaterals by the grid points, and these quadrilaterals are used for volume estimation. An arbitrary point O, in a vicinity of the surface, preferably within the volume, most preferably close to the center of mass of ball 150 , is chosen, thus defining a pyramid 152 for each quadrilateral on the surface of ball 150 . An estimate of the sum of the volumes of pyramids 152 accurately represents the volume of ball 150 .
Preferably, each quadrilateral is divided into two triangles, and the volume is estimated by summing the volumes of tetrahedrons defined by these triangles as bases and vertex O apex. Let A m , B m , C m , denote the vertices of the m-th triangle arranged clockwise, so that the normals of the triangles point outward from the surface of ball 150 . The volume V of ball 150 is estimated by equation (6): V = 1 6 ∑ m ( B m - A m ) × ( C m - A m ) · ( O - A m ) ( 6 )
FIG. 8 is an illustration of a reconstruction procedure, in accordance with another preferred embodiment of the present invention. In this preferred embodiment the sampled points are known to be on a single, open surface, rather surrounding a 3D volume, and therefore the beginning grid may comprise an open plane, rather than a closed curve. Catheter 20 is brought into contact with a plurality of locations on an inner wall 76 of heart 70 , and the coordinates of these locations are determined to give sampled points 120 . Preferably, a physician indicates to console 34 the direction from which catheter 20 contacts surface 76 . Computer 36 accordingly generates an initial grid 122 , which includes a plurality of grid points 124 , such that all the grid points are preferably on one side of the sampled points. The adjustment procedure is performed substantially as described above, bringing grid points 124 to maximally resemble surface 76 .
In a preferred embodiment of the present invention, the adjustment procedure may be performed step-by-step on display 42 , allowing the physician to interrupt and direct the procedure if necessary.
It is noted that although the above description assumes that the data regarding the sampled points are acquired by the system which performs the reconstruction, the reconstruction procedure may also be performed on points received from any source, such as from a different computer, a library database or an imaging system. Furthermore, although preferred embodiments are described herein with reference to mapping of the heart, it will be appreciated that the principles and methods of the present invention may similarly be applied to 3D reconstruction of other physiological structure and cavities, as well as in non-medical areas of 3D image reconstruction.
As noted above, an important example of a physiological parameter of the heart, that is measured using functional portion 24 of catheter 20 and that is assigned to the grid points that are associated with the sampled points, is the local activation time (LAT) of the heart tissue. This time is determined by referring the time of a feature of the signal (specifically, a voltage) measured by functional portion 24 at each sampled point, for example, the time in the cardiac cycle at which that signal first exceeds a certain threshold, to the time within the cardiac cycle of a fiducial feature of the ECG signal, as measured, for example, using ECG monitor 73 . Preferably, the grid on which LAT is posted is the grid corresponding to end diastole, because the heart is most fully expanded at that point in the cardiac cycle, and the interior surfaces of the chamber of the heart consequently are smoothest at that point in the cardiac cycle.
The values of LAT, that are posted at the grid points associated with the sampled points, are interpolated to the other grid points, as described above. Preferably, this interpolation is done using a variant of the zero-order-hold filling method, based on the distance d(V) from each grid point V to the nearest sampled points, as measured along the grid.
Initially, the grid points that coincide with sample points are assigned d(V) values of zero, and all the other grid points are assigned d(V) values of infinity. Then, in each of a sequence of iterations, each grid point V is visited in turn, and is assigned a new value of d(V), based on the distance d(V,N i ) between that grid point V and its m neighboring grid points N i ε{N i , . . . ,N m }. Specifically, d(V) is replaced with min[d(V),min i (d(N i )+d(V,N i ))]. As each grid point V is assigned a new value of d(V), that grid point V also is assigned the LAT value associated with the neighbor N i upon which the new value of d(V) is based. These iterations are continued as long as at least one d(V) changes in the course of an iteration. Finally, the posted LAT values are smoothed by convolution, as described above in the context of the final adjustment of grid geometry.
The preferred 3D grid is one in which the grid points are connected by lines in a way that defines the grid as a collection of polygons, for instance triangles, with the grid points constituting the vertices of the triangles and with the lines connecting the grid points constituting the edges of the triangles. In such a grid, a preliminary version of the propagation velocity of the activation signal, i.e., the conduction velocity of the heart tissue, is obtained by assigning a velocity vector to each triangle, based on the LAT values at the triangle's vertices. It is assumed that the grid is sufficiently fine that, in each triangle, the activation signal propagates as a plane wave. FIG. 9 shows a triangle 200 with vertices {right arrow over (a)}, {right arrow over (b)} and {right arrow over (c)}, and with a planar wavefront 202 propagating across triangle 200 towards the upper right at a velocity {right arrow over (v)}. Note that wavefront 202 is perpendicular to the direction of propagation. Wavefront 202 is shown at the time t b at which wavefront 202 reaches vertex {right arrow over (b)}. This time is at least as great as the time t a at which wavefront 202 reached vertex {right arrow over (a)}, and is no greater than the time t c , at which wavefront 202 will reach vertex {right arrow over (c)}: t a ≦t b ≦t c . Wavefront 202 intersects side ac of triangle 200 that is opposite vertex {right arrow over (b)} at a point {right arrow over (d)}. Point {right arrow over (d)} is found by linear interpolation: d → = t b - t a t c - t a c → + t c - t b t c - t a a → ( 7 )
The unit vector in the direction of {right arrow over (v)} is found by taking the cross product of {right arrow over (d)}−{right arrow over (b)} with the unit vector {right arrow over (N)} normal to triangle 200 and normalizing: v → v → = d → - b → d → - b → × N → ( 8 )
Finally, the magnitude of {right arrow over (v)} is found by projecting the apparent velocity from {right arrow over (a)} to {right arrow over (c)} onto this unit vector: v → = c → - a → t c - t a · v → v → ( 9 )
Having thus assigned a velocity vector to each triangle of the grid, each grid point is assigned a raw velocity vector by averaging the velocities of all the triangles of which that grid point is a vertex. Finally, the raw velocities are smoothed iteratively, as follows:
1. Each triangle is assigned, as a new velocity, the average of the velocities assigned to the grid points which are the vertices of the triangle.
2. Each grid point is assigned, as a new velocity, the average of the velocities assigned to the triangles of which the grid point is a vertex.
Preferably, the conduction velocity vector function thus obtained is displayed superposed on a display of the surface represented by the grid, both as a pseudocolor map, as described above, or as arrows emerging from the grid points. In one variant of this display, the direction of the arrow at each grid point corresponds to the direction of {right arrow over (v)} as posted and smoothed at that grid point; and the length of the arrow corresponds to the magnitude of {right arrow over (v)} as posted and smoothed at that grid point. Alternatively, all the arrows have the same length, and the arrows are displayed in monochrome or achromatic manner, using a gray scale that encodes the magnitudes of {right arrow over (v)}. Alternatively, the arrows may be displayed according to a specific color scheme. The iterative smoothing parameters may be determined by a priori knowledge of the specific heart.
It will be appreciated that any vector function that is derived from a set of scalar measurements on the surface of a biological structure may be displayed in this manner. Furthermore, the vector function may be displayed along with the scalar measurements from which it was derived, or along with a scalar function of the scalar measurements from which the vector function was derived. For example, LAT may be displayed as a pseudocolor map, and the corresponding conduction velocity vector function may be displayed as arrows superposed on the pseudocolor map, as described above.
FIG. 10 shows such a display of a normal human atrium. LAT is normally displayed as a scale in pseudocolor, but is herein depicted with a numerical scale. The numerical scale with respect to the LAT ranges from a minimum (1) which is the earliest activation time, to a maximum (10) which is the latest activation time. The direction of the corresponding conduction velocity vector field is shown by the arrows. The arrows are displayed in monochrome, with the gray scale level of each arrow corresponding to the magnitude of the associated conduction velocity vector. As is shown in the lower left hand portion of the figure, the velocity magnitude scale ranges from a minimum (solid black arrow) to a maximum (open headed arrow). Midrange is shown with a dotted arrow. The signal flow is predominantly radially away from the region numbered one (1) in which activation is initiated.
FIG. 11 is a similar display of LAT and conduction velocity in a human atrium suffering from atrial flutter. The signal flow tends to be vortical, rather than radially outward. This vortical flow is evidenced by the distinct and separate patterns of conduction velocity vector arrows shown.
FIG. 12 shows a pattern on such a display that is diagnostic of ventricular tachycardia: a region of scar tissue associated with a vortical conduction velocity field that is represented by circular patterns of arrows. LAT is shown with a numerical scale from 1 to 10. A physician treats ventricular tachycardia thus diagnosed by ablating the heart tissue in the region of the pattern shown in FIG. 12 . Such a display also provides quality control diagnostics, inasmuch as the magnitude of the conduction velocity is expected to be abnormally low in scar tissue.
FIG. 13 shows the conduction velocity vectors alone (without display of LAT regions) in the left ventricle of a dog. The heart is entrained in a sinus rhythm from the right ventricle apex. The velocity vector arrows are distributed according to the density of the underlined grid. Each arrow represents the local conduction velocity. The arrow direction is the computed direction of the conduction and its gray scale color represents the conduction velocity magnitude (black colored arrows indicate slow conduction velocity, gray colored arrows indicate midrange conduction velocity and white colored arrows indicate fast conduction velocity).
FIG. 14 is the right atrium of a human heart suffering from atrial flutter. The conduction velocity vectors are also depicted alone, e.g. without display of LAT regions or other parameters. Rather than having a well-defined focus that starts the activation in the heart, such as that found in the heart example depicted in FIG. 10, the cardiac wave, as depicted by the conduction velocity vectors, moves in distinct circular patterns. These circulated patterns result in a convergence of the cardiac wave as shown along the lower central portion of the atrium. One type of treatment involves ablations along this area of the atrium in order to disable the abnormal circuitry. After ablation, the chamber can be remapped to ensure that the procedure has been performed successfully.
Other scalar functions of the ECG measurements used to derive LAT also are useful. One such scalar function is the amplitude (maximum−minimum) of voltages measured at each sampled point over the course of the cardiac cycle. A low amplitude is diagnostic of scar tissue. Most preferably, voltage amplitude, LAT and conduction velocity are displayed together. Voltage amplitude is encoded in a conventional pseudocolor map. LAT is encoded as colored dots posted on the sampled points. Conduction velocity is displayed as arrows, as described above.
As mentioned previously, once the conduction velocity vectors, (indicated by arrows), are displayed superimposed on the 3D map of the surface of the heart, treatment may be administered to those areas of the heart depicted as being problematic based on the displayed velocity vectors. For instance, ablative treatment is administered at those areas depicting velocity vector direction, e.g. converging arrows such as shown in FIGS. 11 and 14. It is within the scope of the present invention to include any type of treatment modality such as the application of energy, for example laser, therapeutic ultrasound, radiofrequency, etc. as well as pharmaceutical or biological therapy. Moreover, therapeutic treatment may be administered based on the magnitude of the velocity vectors. For instance, in the gray scale embodiment, those velocity vector arrows that are identified by the color black indicate low conduction velocity. Since the propagation wave is identified to move slowly through this portion of the heart, this may be indicative of diseased tissue or scar tissue.
Another useful quality control diagnostic is obtained by displaying yet a third scalar field. This scalar field is obtained by performing calculations of conduction velocity as described above, but excluding, from each calculation, one of the sampled points, with a different sampled point being excluded from each calculation. This is done for each sampled point, thereby producing as many calculations of the conduction velocity field as there are sampled points. The associated scalar field is, at each grid point, the range (maximum−minimum) of conduction velocity magnitudes obtained at that grid point. This scalar field, displayed in pseudocolor, provides a measure of the reliability of the calculated conduction velocity field at each grid point.
It is also possible to display the conduction velocity with other physiological maps, for example, the voltage map or the impedance map, generated for the same recordings of the organ.
It is noted that the above displays may be displayed in at least two ways: by a color from the pseudocolor scale when the value represents one that is of a determined confidence level and as such, may be placed directly on the pseudocolor map; and by another, different color or transparency, when the value is of low confidence and as such, is so displayed on the map. In the latter case, the practitioner will be guided to acquire more samples.
It will thus be appreciated that the preferred embodiments of the invention described above are cited by way of example, and the full scope of the invention is limited only by the claims which follow. | A method of diagnosing an abnormal condition in a biological structure, such as the heart, including the steps of measuring a physiological response at at least three sampled points on a surface of the biological structure, calculating a vector function related to the response, displaying a representation of the vector function, and inferring the abnormal condition from the representation. The present invention is particularly useful for diagnosing cardiac arrhythmias, in which case the physiological response is a voltage, from which is inferred a local activation time and the vector function is a gradient of the local activation time, specifically, a conduction velocity. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method and an apparatus for reducing power consumption of one or more processors in response to a failure condition affecting the processor or processors such as a thermal failure condition, and to a computer system incorporating such a method and/or apparatus.
[0002] In recent years, the processing power of processors has been increasing at a high rate. This increase in processing power has caused processors to heat up faster and to a higher temperature than previous processors. Therefore as the processing power has increased, a need has arisen for cooling the processor so that an overtemperature condition does not occur, since damage to the processor can occur if the temperature remains at too high of a level.
[0003] As the processing power of processors has increased and the need for maintaining the processor at a relatively low temperature has become important, new ways of maintaining a relatively low temperature of the processor have been implemented. For example, heat sinks have been attached directly on or near the processor to help dissipate some of the heat from the processor. Additionally, cooling fans have been used to blow air in the general vicinity of the processor or at the processor to help keep the processor from overheating. However, even when taking these measures, overtemperature problems can occur. Additionally, with the increase of processing power, the requirement for large heat sinks, blowers, cooling fans or other cooling mechanisms can cause size and expense problems, and these mechanisms are still sometimes unable to properly cool some processors even when these cooling mechanisms are operating at full efficiency.
[0004] In case of a failure, the temperature of the processor can rise to an overtemperature condition even if a cooling fan, a heat sink, or another cooling mechanism normally is able to maintain the desired temperature of the processor. For example, the cooling fan may fail for some reason (i.e., the speed of the cooling fan may be reduced or it may completely stop). In this case, the temperature of the processor can rise to a level which creates damage to the processor. Additionally, as processing power increases in current generation and future generation processors, additional measures for maintaining the temperature of the processor may become necessary. Therefore, a need has arisen for additional ways of maintaining the temperature of the processor below a predetermined level. These additional measures may be in addition to or in place of current implementations using cooling devices such as heat sinks and cooling fans.
[0005] In addition to using cooling devices such as heat sinks and cooling fans, other methods for ensuring that the temperature of a processor or processors does not become too high have previously been contemplated. For example, a failure signal corresponding to a reduced performance of a cooling mechanism such as a cooling fan can be produced when the cooling mechanism either fails or has some sort of other reduction in performance thereof. This signal is then used to completely shut down the processor, or provide a warning signal to the user of a personal computer or to a network manager, for example. However, if the signal is sent to the personal computer user or network manager (or other user) without turning off the processor, continued use of the processor could result in damage to the processor or other components of the system. Similarly, if the processor is shut off, a resulting reduction in performance of the processor or processors occurs during the time which the processor is shut off. If the processor is shut down, it is not operational until the failure is resolved. If such a processor is included in a uni-processor system, a system crash will occur and the entire system is shut down.
[0006] Additionally, other problems can occur with respect to signals sent to the processor relating to vital functions of the system which are not received by the processor during the time which the processor is turned off. For example, the time-out of vital functions may occur if the processor is shut off for too long of a time period. These signals relating to vital functions of the system are sent to the processor for only a specific length of time before a time-out of the signal occurs. If this time-out occurs, the processor does not receive the signals or perform any functions in response to these signals relating to vital functions of the system. For example, if a LAN (Local Area Network) network card is inserted and expecting a response from the processor, the network cards might drop clients if the processor does not respond to certain signals prior to a time-out of those signals (i.e., within a predetermined time period). Therefore, a reduction of the power of a processor while still performing some processing functions would be beneficial so that the processor is not damaged and so that no vital functions of the processor or system are inadvertently not performed.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, in order to reduce the power consumption of a processor, a failure signal is produced which indicates a failure condition affecting the processor. In response to the failure signal, the power consumption of the processor is periodically reduced. This failure condition affecting the processor may be a thermal failure condition (or over-temperature condition).
[0008] In an illustrated embodiment, the processor includes a reduced power input. Power consumption of a processor is reduced in response to a first signal level at the input and is not reduced in response to a second signal level at the input. A power reduction circuit provides the power reduction signal to the input of the processor in response to a failure condition affecting the processor. The signal provided to the input of the processor in response to the failure condition is a periodic signal alternately supplying the first signal level which causes a reduction in the power consumption of the processor and the second signal level which does not cause a reduction in the power consumption of the processor.
[0009] The present invention allows a reduction in power consumption of a processor or processors in an economical manner when a failure condition occurs. In described embodiments of the present invention, the failure condition is a thermal failure condition which occurs when the cooling mechanism fails or when a temperature of the processor or processors increases to a high level. The present invention performs this reduction in power consumption without shutting down the processor entirely. The processor is allowed to continue to function at a reduced performance level without missing the receipt of signals provided to the processor relating to functions of the system, which may include vital functions of the system.
[0010] In illustrated embodiments of the present invention, upon detection of a failure condition affecting the processor (such as a failure or a reduced performance of a cooling mechanism or a high temperature condition at or near the processor), the power consumption of the processor is periodically reduced. This periodic reduction in power consumption may be implemented by periodically stopping and starting an internal clock of the processor or periodically reducing the power consumption of the processor in any other manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 illustrates an arrangement for reducing power consumption of a processor according to one embodiment of the present invention.
[0012] [0012]FIG. 2 illustrates a periodic signal provided by the signal generator illustrated in FIG. 1.
[0013] [0013]FIG. 3 illustrates an arrangement for reducing power consumption of a processor according to an embodiment of the present invention.
[0014] [0014]FIG. 4 illustrates an arrangement for reducing the power consumption of a processor according to an additional embodiment of the present invention.
[0015] [0015]FIG. 5 illustrates an arrangement for reducing the power consumption of a processor according to a further embodiment of the present invention.
[0016] [0016]FIG. 6 illustrates a multi-processor system in which the power consumption of one or more processors may be reduced according to an embodiment of the present invention.
[0017] [0017]FIG. 7 illustrates an additional multi-processor system in which the power consumption of one or more processors may be reduced according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0018] [0018]FIG. 1 illustrates an arrangement for reducing the power consumption of a processor according to a first embodiment of the present invention. Illustrated in FIG. 1 are a processor 10 , a failure signal generator 12 , a multiplexor 14 (MUX) and a signal generator 16 . Processor 10 may be any processor or microprocessor including some processors of the microprocessor family developed by Intel Corporation commonly referred to as the x86 family of microprocessors (for example, the 80486, Pentium™ and Pentium Pro™ microprocessors). Additionally, processor 10 may be a later generation processor such as the Pentium Pro™ microprocessor or any other later generation processor.
[0019] In the illustrated embodiment, processor 10 includes a reduced power input 18 . In response to an input signal at a predetermined level on this input 18 , the processor takes some action to reduce its power consumption. For example, input 18 may be an input in response to which the internal clock of the processor 10 is stopped, thereby causing the processor to consume less power. The Pentium™ and Pentium Pro™ processors include an input terminal for a STPCLK input signal which, when at a low level, signifies a request to stop the internal clock of the processor and thereby cause the processor to consume less power. When the Pentium™ or Pentium Pro™ processor recognizes the STPCLK input signal, the processor will stop execution on the next instruction boundary, unless superseded by a higher priority input, and generate a Stop Grant Acknowledge cycle. When the STPCLK input signal is asserted, the Pentium™ or Pentium Pro™ processor will still respond to external snoop requests. Although the STPCLK signal in the Pentium™ and Pentium Pro™ processors is a signal in which the active (or asserted) state occurs when the signal is at a low voltage level, in another processor it could be active at a high level. Further, the processor need not have a STPCLK input. The present invention can be practiced using any processor input which stops the internal clock of the processor, regardless of whether the active or asserted state level is at the high or low voltage level. Some processors include inputs which are used to reduce the power consumption of the processor in some other way, or enable or disable the processor in some manner other than stopping the internal clock of the processor (e.g., a processor enable or processor disable input signal). In such a case, these inputs may also be used in embodiments of the present invention. . 0 Failure signal generator 12 has an output on line 20 which represents a presence of a failure condition affecting the processor 10 . Examples of failure conditions affecting the processor include a failure of a cooling fan cooling the processor or an overtemperature condition of the processor. However, according to an embodiment of the present invention, the signal on line 20 output by the failure signal generator 12 represents any failure condition affecting the processor 10 .
[0020] Multiplexor 14 has two inputs A and B receiving signals on lines 20 and 22 , a select line receiving a select signal on line 24 , and one output coupled to the input 18 of the processor 10 . As illustrated, the input on line 20 provided by the failure signal generator 12 is a signal representing a failure condition affecting the processor 10 . The input on line 22 is a power reduction inactive signal corresponding to an inactive level of the power reduction input signal 18 . The input on line 24 is connected to an output of signal generator 16 . In response to the failure signal 20 , multiplexor 14 selects either the signal on line 22 or the signal on line 24 and outputs that signal on line 18 .
[0021] In response to failure signal 20 , the multiplexor 14 selects either the output 24 of signal generator 16 or a power reduction inactive signal level on line 22 (in implementations using the Pentium™ and Pentium Pro™ processors or any other processors having a signal similar to the STPCLK signal, the power reduction inactive signal will be a high voltage level signal). In this manner, if failure signal 20 indicates that no failure condition affecting the performance of the processor 10 has occurred, the multiplexor 14 selects the power reduction inactive signal level 22 to be output to the power reduction input of the processor 10 . In this case, the processor 10 operates without any reduction in power taking place. If the failure signal 20 indicates a failure condition of the processor 10 , e.g., a reduction in power or failure of a cooling fan or sensed overtemperature of the processor 10 , the multiplexor 14 selects the output 24 of signal generator 16 to be provided to the power reduction input of processor 10 . Multiplexor 14 may be any standard multiplexor or even a simple single pole double switch switching between inputs 22 and 24 based on the failure signal 20 .
[0022] Signal generator 16 has two inputs on lines 26 and 28 , respectively, and provides an output on line 24 . The input on line 26 is a signal representing a desired frequency and/or period and the input on line 28 is a signal representing a desired duty cycle. In response to inputs 26 and 28 , signal generator 16 provides a digital periodic signal on line 24 having one high value and one low value for each period.
[0023] Signal generator 16 is a standard well-known signal generator which generates a digital periodic signal on line 24 responsive to inputs representing the desired frequency or period and/or duty cycle of the periodic signal to be provided to the power reduction input 18 of the. processor 10 . The duty cycle is defined as the ratio between the active level time period and the inactive level time period of the signal.
[0024] The frequency (or period) and duty cycle inputs to signal generator 10 may be predetermined values based on a variety of features of the system. For example, in determining the frequency (or period) input to the signal generator 16 , a minimum processing interval and a maximum heat-up time must be considered. The minimum processing interval must be considered to ensure that all processing functions can be performed within the time provided. The maximum heat-up time is a function of the die size, the maximum ambient temperature, and any thermal resistances to ambient temperature. The maximum heat-up time must be considered to reduce any thermal variation between the active and inactive signal levels. In determining the duty cycle, the minimum processing interval, a short enough time to accommodate possible cooling failures such as fan failure, and an inactive time level which is short enough to ensure that no time-out conditions occur must all be considered. These considerations will vary depending upon the system in which the processor 10 and other power reduction circuitry elements such as failure signal generator 12 , multiplexor 14 and signal generator 16 are included.
[0025] [0025]FIG. 2 illustrates an output signal from signal generator 16 which may be used in implementing embodiments of the present invention such as the embodiment illustrated in FIG. 1. The signal generator 16 generates a periodic signal including active signal levels 32 and inactive signal levels 34 . The signal illustrated in FIG. 2 can be applied as the STPCLK input to the Pentium™ and Pentium Pro™ processors, i.e., it is a low voltage level active signal. Alternatively, the signal illustrated in FIG. 2 would be inverted in an embodiment of the present invention in which the stop clock input to processor 10 were a high voltage level active signal.
[0026] The signal illustrated in FIG. 2 can include a signal which may be output from signal generator 16 using the following system conditions: Pentium™ processor and EISA refresh timeout of 100 μ sec. In such a system, a possible frequency of the signal illustrated in FIG. 2 is 100 kHz. Additionally, a possible duty cycle of the signal illustrated in FIG. 2 would be 25/75 (i.e., where the periodic signal has an active signal level 75% of the time and an inactive signal level 25% of the time).
[0027] While these values have been given as an example of the signal output from signal generator 16 , any values providing a frequency and duty cycle meeting the following requirements may be used. Specifically, in determining the frequency, the minimum processing interval of the processor and/or the entire system and the maximum heat-up time must be considered. In determining the duty cycle, the minimum processing interval, the ensuring of enough inactive time to accommodate possible cooling failures, and an inactive time short enough to ensure that no time-out conditions occur should be considered. Additionally, any other input values may be used as inputs to the signal generator which may be used to describe a periodic signal (e.g., active and inactive level times, etc.)
[0028] [0028]FIG. 3 illustrates an arrangement which may be used to reduce power consumption of a processor according to another embodiment of the present invention. FIG. 3 includes processor 10 , multiplexor 14 , signal generator 16 and cooling fan 36 . Processor 10 , multiplexor 14 and signal generator 16 function similarly to the corresponding elements of FIG. 1. Therefore, a description of these elements is not included in the description of FIG. 2.
[0029] Cooling fan 36 is used to blow cool air in the direction of the processor 10 . This cool air is used to maintain the processor 10 at a temperature low enough so that damage to the processor 10 does not occur due to an overtemperature condition. If reduced performance of cooling fan 36 occurs (for example, a reduction in the speed of the cooling fan or a failure of the cooling fan altogether), a fan failure signal 38 is provided. This fan failure signal 38 is provided to the select input of multiplexor 14 . The fan failure signal 38 may be directly provided from the cooling fan 36 or externally provided by a circuit detecting a failure or a reduced performance of the cooling fan 36 . For example, an active level of the fan failure signal 38 may be provided if the speed of fan 12 falls below a predetermined level.
[0030] In the embodiment illustrated in FIG. 3, the multiplexor selects the power reduction inactive signal on line 22 if the fan failure signal 38 ,. indicates no fan failure and selects the output of signal generator 16 on line 24 if the fan failure signal 38 indicates a fan failure. The power consumption of processor 10 is therefore periodically reduced based on the fan failure signal 38 the output of multiplexor 14 provided to the power reduction input 18 of the processor 10 .
[0031] [0031]FIG. 4 illustrates an arrangement which may be used to reduce the power consumption of a processor according to a further embodiment of the present invention. In FIG. 4, processor 10 is mounted, for example, on a printed circuit board (PCB) 40 . A heat sink 42 is attached to processor 10 to provide an enhanced dissipation of heat from processor 10 . A thermocouple 44 is embedded in heat sink 42 to measure a temperature near processor 10 . Thermocouple 44 could be any temperature sensor device used to measure or sense the temperature at or near the processor 10 (such as a temperature sensor diode). Additionally, as an alternative to the thermocouple arrangement of FIG. 4, embodiments of the present invention may be practiced in which a device sensing any sort of failure at or near the processor 10 is used.
[0032] Thermocouple 44 provides an analog signal on line 46 to a connection 48 on the printed circuit board 40 . This analog signal is representative of the temperature at or near the processor 10 . The analog temperature value is used to provide a failure signal similar to the failure signal 20 of FIG. 1 to an arrangement similar to multiplexor 14 and signal generator 16 , which provide an input to processor 10 used to reduce the power consumption of the processor in a manner similar to the arrangement of FIG. 1. An example of such an implementation is illustrated in FIG. 5.
[0033] [0033]FIG. 5 illustrates an arrangement according to an embodiment of the present invention which may be used in conjunction with the arrangement illustrated in FIG. 4. FIG. 5 includes a processor 10 , a multiplexor 14 , a signal generator 16 , a temperature sensor 52 , an analog-to-digital (AID) converter 54 and a look-up table 56 .
[0034] Temperature sensor 52 senses a temperature at or near processor 10 . Temperature sensor 52 may be a thermocouple located on or near processor 10 (e.g., thermocouple 44 of FIG. 4) or any other temperature sensor. The sensed temperature output from temperature sensor 52 is provided to analog-to-digital (AID) converter 54 . This signal may be provided, for example, via a connection such as connection 48 of FIG. 4. A/D converter 54 converts the sensed analog temperature to a digital signal representative of the temperature.
[0035] The digital signal output from A/D converter 54 and corresponding to the sensed temperature is provided to a look-up table 56 . Look-up table 56 may be a Read Only Memory (ROM) or any other memory, for example. Look-up table 56 stores values to be provided to the select input oft. multiplexor 14 based on the sensed digital value. Each digital value has an entry storing a corresponding value to be provided to the select input of multiplexor 14 . For example, any digital sensed values at or above a predetermined temperature will reference an entry in the look-up table 56 corresponding to that digital value and storing a select signal for the multiplexor 14 causing the multiplexor to select the output from the signal generator 16 . Similarly, in response to any value lower than the predetermined temperature, the look-up table provides a select signal so that the multiplexor 14 selects the power reduction inactive signal. In this manner, the multiplexor 14 provides the periodic signal output by signal generator 16 when the temperature at or near the processor 10 sensed by temperature sensor 52 is at or above a predetermined temperature value (e.g., 45° C. or 85° C., etc.) and provides a power reduction inactive signal to the power reduction input of processor 10 when the sensed temperature is lower than that value. The predetermined temperature is preferably a temperature well below the temperature-at which the rated maximum wattage value of the processor will be reached.
[0036] As an alternative embodiment to the embodiment of FIG. 5, a comparator can be used in place of the look-up table 56 . The comparator compares the temperature provided from A/D converter 54 with a predetermined temperature value and provides the result of the comparison to the select input of multiplexor 14 .
[0037] [0037]FIG. 6 illustrates an embodiment of the present invention in which a plurality of processors are arranged in a computer system. In FIG. 6, processors 60 , 62 and 64 are included in a computer system such as a workstation or networking environment. Power reduction circuits 66 , 68 and 70 are used to periodically reduce the power consumption of respective processors 60 , 62 and 64 in response to a signal indicating a failure condition affecting the processor. Power reduction circuits 66 , 68 and 70 may include the power reduction circuits illustrated in FIGS. 1, 3 and 4 , for example. Specifically, power reduction circuits 66 , 68 and 70 may each include a failure signal generator 12 , a multiplexor 14 and a signal generator 16 as illustrated in FIG. 1, or may include a cooling fan 36 , a multiplexor 14 and a signal generator 16 as illustrated in FIG. 3, or may include a temperature sensor 52 (or thermocouple 44 ), an analog-to-digital (A/D) converter 54 , a look-up table 56 , a multiplexor 14 and a signal generator 16 as illustrated in FIGS. 4 and 5. Each of the power reduction circuits 66 , 68 and 70 may also be any other arrangement providing a signal used to periodically reduce the power consumption of a processor or processors. The power reduction circuits 66 , 68 and 70 respectively provide a signal to the power reduction input of processors 60 , 62 and 64 to periodically reduce the power of the respective processor.
[0038] The input signal to the power reduction circuits corresponding to a reduction in performance of the processor could relate to a failure or reduction in performance of a cooling fan blowing air toward the respective processor or a temperature (or overtemperature condition) at or near the respective processor.
[0039] Alternatively, a multi-processor embodiment of the present invention can be used in which one power reduction circuit provides the periodic signal to the power reduction inputs of all of the processors upon detection of a failure condition at or near any of the processors or of a failure condition relating to an overall cooling mechanism such as a cooling fan which cools all of the processors, or any separate cooling fan corresponding to a particular processor. Such an embodiment is illustrated in FIG. 7. FIG. 7 includes a power reduction circuit 72 detecting a failure condition affecting one or more of the processors 60 , 62 and 64 and providing a signal to the power reduction inputs of one or more (or all) of the processors 60 , 62 and 64 in response to the failure condition to periodically reduce power consumption of one or more (or all) of the processors 60 , 62 and 64 .
[0040] While the multi-processor embodiments of FIGS. 6 and 7 have been illustrated in a three processor system, it is noted that embodiments of the present invention may be implemented in systems including any multiple number of processors (i.e., two or more processors). That is, multi-processor embodiments of the present invention are not limited to three processors. | An apparatus, a method and a computer system can be used to reduce power consumption of one or more processors in response to a failure condition such as an overtemperature condition affecting the processor or processors. A signal is provided which indicates a failure condition affecting the processor such as an overtemperature condition or a failure or reduction in performance of a cooling mechanism. In response to the signal, a power consumption of the processor is periodically reduced. This can be accomplished by providing a periodic signal to an input of the processor (e.g., a stop clock input or a processor enable input). The processor reduces power consumption by stopping an internal clock of the processor, for example. The periodic signal can be provided to the input of the processor to periodically reduce power consumption. In this manner, power consumption of the processor may be reduced without shutting down the processor entirely, while maintaining some processor functions and without missing the receipt of any signals corresponding to vital functions of the processor system while the power consumption of the processor is reduced. | 8 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to logic circuits, and more particularly to digitally configurable sequential logic circuits for serial bit pattern generation.
2. Discussion
A serial binary pattern generator is a sequential logic circuit which produces a sequence of binary values at its output. The bits which make up the sequence appear at the output of the circuit serially, one bit per cycle of the input clock.
There is a nearly infinite variety of binary sequences which can be produced by sequential logic circuits. One particularly useful kind of sequence is one defined here as "maximally spread." Every finite sequence of bits contains some number of ones and some number of zeros. A maximally spread sequence of bits has the property that if one constructs an infinite sequence by laying copies of the finite sequence end to end along a line in both directions infinitely, all the ones in the infinite sequence are as far apart from each other as possible, and all the zeros in the infinite sequence are as far apart from each other as possible. For example if there are an equal number of ones and zeros in the finite sequence, then the ones and zeros would alternate: "...1010101010..." If there are 3 ones for every 5 zeros in the finite sequence then the maximally spread sequence would be: "...1001001010010010..." No rearrangement of the ones and zeros in such a sequence would separate the ones from each other any better, or separate the zeros from each other any better.
A device is digitally configurable if its operation can be modified by changing the value of one or more digital words presented to the device as control values.
Given these definitions, the present invention is a digitally configurable serial binary pattern generator which produces maximally spread binary sequences at its output. Such a device has a variety of applications. The following paragraphs describe three such applications. They are: clock division by rational numbers, data stuffing, and precision duty cycle generation.
Logic circuits are used in a variety of electronic and computer applications to perform various functions. Typically, each component of a logic circuit requires a clock input to trigger the execution of the component's logic routine. Currently various high rate digital clocks are available. It sometimes becomes necessary or desirable to generate synchronous lower rate clocks by "dividing" an available high rate source clock. This can be accomplished with simple logic if the ratio of the source clock frequency to the desired clock frequency is an even integer, (e.g., dividing a 20 kHz source clock by 4 to produce a desired 5 kHz clock). Division by an even integer is a simple case because a fixed integer number of source clock periods separate successive leading and trailing edges of the desired clock signal. However if the ratio of the source clock frequency to the desired clock frequency is an odd integer or not an integer at all then generation of the desired synchronous, lower frequency clock is more difficult. For the case where the ratio of the source to desired clock frequencies can be expressed as the ratio of two positive integers, the present invention can be combined with simple external circuitry to produce the best all-digital approximation to the desired clock. The clock so produced will have the same average frequency (leading edges per second) as a 50% duty cycle clock of the desired frequency, but its leading and trailing edges will always be coincident with leading edges of the source clock. Such a clock signal is acceptable in most digital circuits and essential in some. Traditionally, the production of such a clock involves the use of analog frequency synthesizers. That approach brings with it all the attendant difficulties in mixing analog and digital circuits especially with respect to synchronization requirements.
In a variety of digital data communication circuits, the allowable input data rate of a device is constrained to be among a small set of rates, e.g., 25, 50, and 100 Mbps. When it is desired to transmit data from a digital source whose rate is not in the allowed set, the source data can be "stuffed" with extraneous data to bring the combined rate up to an allowable rate. For example, a 47 Mbps data source could be stuffed with 3 Mbps of extraneous data to produce a combined data rate of 50 Mbps. Such a scheme is only practical if the extraneous data can later be filtered out. Perhaps the simplest scheme for mixing the two data streams is to send, e.g., 47 "data bits" followed by 3 "stuff bits." However, to minimize the required bandwidth of the circuitry involved, it is desirable to spread out the stuff bits as much as possible within the data bits. For example, send 47 data bits and 3 stuff bits in the following order: 16 data bits, 1 stuff bit, 16 data bits, 1 stuff bit, 15 data bits, 1 stuff bit. The use of a digitally configurable device which could produce such a repeatable, "maximally spread" stuff/data bit pattern for a wide range of stuff/data rate ratios would give a great deal of flexibility.
It is sometimes desired to produce a binary signal with a known duty cycle. If a duty cycle of M/N is desired, a simple way to accomplish this is to hold an output signal high for M clock cycles and low for N-M clock cycles. If the M clock cycles during which the output is high are spread out as described above among the N-M clock cycles during which the output is low, then the instantaneous deviation of the output signal's duty cycle from the desired duty cycle is minimized. Such a signal could, for example, be applied to a low-pass filter to produce a precision DC voltage equal to M/N times a precision reference voltage. If M and N are digitally programmable then the output from such a circuit will be a digitally programmable precision voltage.
SUMMARY OF THE INVENTION
In accordance with the teachings of the present invention, a digital logic circuit is provided that accepts two parallel control words as configuration inputs, and produces a serial binary data stream as its output. If the two configuration words are denoted "A" and "B" the output stream will contain A ones and B zeros in every (A+B) output bits. Additionally, the ones and zeros will be maximally spread apart. The circuit implementation includes a Load input which allows new configuration values to be latched into the circuit, and a Reset input to force the circuit to a known state. As will appear, the present invention has a wide variety of applications.
BRIEF DESCRIPTION OF THE DRAWINGS
It is convenient in drawings to have a concise way to refer to the present invention. Because the essential feature of the present invention is that it generates maximally spread bit patterns, the abbreviated name for the present invention is "Spreader."
The various advantages of the present invention will become apparent to those skilled in the art after study of the specification and by reference to the drawings in which:
FIG. 1 is a circuit diagram of the invention showing the interconnection of the various components in accordance with the teachings of the preferred embodiment of this invention;
FIG. 2 is a table demonstrating the operation of the circuit of FIG. 1; and
FIGS. 3a through 3c show implementations of several example applications of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It should be understood from the outset that the present invention will be described in connection with a few limiting examples which illustrate the best mode of practicing the invention at the time this application was filed. However, various modifications will become apparent to those skilled in the art after having the benefit of studying the text, drawings and claims which follow this detailed specification. With that in mind, the attention of the reader should now be turned to the drawings, especially FIG. 1.
The discussion below uses the term flip-flop to mean a logic device which can sample and hold a single binary value. Sampling of the value at the flip-flop's D input is accomplished on each rising edge of the flip-flop's clock input. This sampling is called "latching." The value held by the flip-flop can only be changed by latching. Changes in the value at the flip-flop's D input are ignored until the next latching. The held value and its inverse are available at the flip-flop's Q and Q-bar outputs respectively. The discussion below uses the term "register" to mean a set of flip-flops clocked by a common clock, and considered to hold a single multi-bit value. There are several multi-wire signal paths (busses) shown in the circuit diagram. The number of flip-flops in each register is equal to the number of wires in each bus. This number is denoted "M".
In accordance with the preferred teachings of this invention, M-bit parallel digital data sources 12 and 14 are provided to be latched into registers 30 and 32 respectively. A Load source 16 and Reset source 18 are also provided. These configuration and control sources would preferably come from a microprocessor or other programmable device, allowing a large degree of flexibility in an application.
During typical operation of the circuit, a pair of control words is latched into the configuration section 20 to configure the circuit. On each rising edge of the clock input, the generator section updates the accumulated value in register I 48 by either adding to it the value held in register B 32 or subtracting from it the value held in register A 30. The decision of whether to add to or subtract from the value I 48 is based on the previous circuit output. The resulting output of the circuit is based on the two's complement arithmetic sign of the resulting value held in register I 48. Auxiliary outputs are also provided which mark significant bits in the output data stream as described below. These outputs are based on the value held in register I 48. Specifically, the timing of the auxiliary outputs relates to detecting when the value held in register I 48 has the M-bit value zero.
With the symbol "A" denoting the value held in register A 30, and the symbol "B" denoting the value held in register B 32, the serial binary data produced at the circuit output, after a Load or Reset, has the following properties: the first output is a one; within every set of (A+B) output bits there are A ones and B zeros; within every set of (A+B) output bits, the ones and zeros are maximally spread apart. Two auxiliary outputs are provided which mark significant bits in the output data stream. A "pattern" in the output data stream is a set of output bits marked at the beginning by a value of one on the "Start of Pattern" output 80, and marked at the end by a value of one on the "End of Pattern" output 82. The length of a pattern is equal to (A+B)/gcd (A,B) where gcd (A,B) denotes the greatest common divisor of A and B. The circuit output at the beginning of a pattern is always a one, and the circuit output at the end of a pattern is always a zero.
The configuration section 20 consists of two registers 30 and 32. The reset section 22 consists of a two-input OR gate 40. The generator section 24 consists of an M-bit 2:1 multiplexer 44, an M-bit full adder 46, and a register 48. The multiplexer 44 has two inputs 36 and 38 derived from the outputs of registers 30 and 32 respectively. Additionally, the multiplexer 44 has a select line 50 to determine which logic function the generator section will perform. The output section 26 consists of a digital inverter 64 and a flip-flop 66. The auxiliary section 28 consists of an M-input AND gate 74 and a flip-flop 76.
The configuration section 20 of the circuit accepts and holds two M-bit parallel control words which configure the pattern desired at the circuit output. The first control word is latched into register A 30, and the second control word is latched into register B 32. Register A 30 and register B 32 each have a clock input 34 to determine when the input control words will be latched. This clock input 34 is derived from the Load source 16. Once these control words are latched they are typically held during the generation of a large number of bits at the circuit output. Register A 30 has a Q-bar output 36, whose value is the one's complement (logical inverse) of the latched value. Register B 32 has a Q output 38, whose value is identical to the latched value.
The function of the generator section is to maintain and update the accumulated value in register I 48, and to provide a carry output 62 which is based sign of the value in register I 48; and an auxiliary output 60 which is the one's complement of the value in register I 48. The generator section accepts three inputs: the M-bit values A-bar (one's complement of the value held in register A 36), B (the value held in register B 38), and the single-bit value derived from the Q-bar output 72 of the output section 26. The M-bit 2:1 multiplexer 44 has a select input 50 derived from the Q-bar output 72 of the output section 26. When the select input 50 is a one, the output 54 is a copy of the input value A-bar 36. When the select input 50 is a zero, output 54 is a copy of the input value B 38. Output 54 of multiplexer 44 is fed to input J of full adder 46.
The combination of multiplexer 44 and M-bit full adder 46 uses two's complement arithmetic to either subtract the value held in register A 30 from, or add the value held in register B 32 to, the accumulated value held in register I 48. Full adder 46 accepts three inputs and produces two outputs. The first input is from line 52, the M-bit value held in register I 48. The second input is from line 54, the M-bit value J produced by multiplexer 44 as described above. The third input is a carry in value 56 derived from the Q-bar output 72 of the output section 26. Full adder 46 performs an "Add with Carry" operation on its inputs producing two outputs. The sum output 58 of the full adder 46 becomes the next value to be held in register I 48. The carry output 62 of the full adder 46 goes to the output section 26 for further processing.
The output section 26 processes the carry output 62 of the full adder 46 to produce the final output 70 of the device. The input 62 to the output section is first inverted by passing through a digital inverter 64. The inverted value 68 is then fed into flip-flop 66. Flip-flop 66 has two outputs: Q 70, the output of the device, and Q-bar 72 which is fed back to the generator section 24 to determine whether the next operation of the generator section will be addition or subtraction.
The auxiliary section 28 provides an in-depth way of monitoring the pattern produced at the circuit output which is useful in certain applications. The output of the circuit is a serial stream of bits repeating a unique data pattern. The pattern is determined by the configuration words latched into the configuration section. It is desirable to have a digital marker for the start and end of this pattern. This auxiliary circuit fulfills this need.
The Start of Pattern output 80 is a one only during the first bit of the unique data pattern. The End of Pattern output 82 is a one only during the last bit of the unique pattern. The AND gate 74 has M inputs from the Q-bar 60 output of register I 48. The output 78 of AND gate 74 is a one whenever the value stored in register I 48 is equal to the M-bit value zero. The "End of Pattern" output 82 is derived from the output 78 of the AND gate 74. The output 78 of the AND gate 74 is also fed into flip-flop 76 which delays it by one clock cycle to produce the "Start of Pattern" output 80. The Start of Pattern output 80 is always a one exactly one clock cycle after the End of a Pattern output 82 is a one.
The reset section 22 provides a means to reset the circuit to a known state; and ensures that when new values are latched into the configuration section, the circuit is reset to the same known state. As implemented in the preferred embodiment, the Load input must be held low whenever the Reset input is pulsed low-high-low. Likewise the Reset input must be held low whenever the Load input is pulsed low-high-low. A Load or Reset forces the circuit output 70 to be zero, the Start of Pattern output 80 to be zero, and the End of Pattern output 82 to be one. On the first clock edge after a Load or Reset the circuit output 70 becomes a one, the Start of Pattern output 80 becomes a one, and the End of Pattern output 82 becomes a zero.
Register I 48 and the flip-flops 66 and 76 are all controlled by a common clock input. On each rising edge of the clock, the value present at the input of each device is "clocked through" to the output of the device. The latched value is held by each device until the next rising edge of the clock. Each device is also controlled by a Reset input which when set high immediately forces the devices to a known state. The Q output of each device is forced to be zero and the Q-bar is forced to the inverse of zero. This inverse is one for the single bit flip-flops 66 and 76 , and "all ones" for register I 48. This Reset function allows the circuit to be placed in a known state at any time and especially following a load of new configuration values into the configuration section. This ensures the absence of a time lag between the latching of new configuration values and the proper operation of the circuit based on those values.
FIG. 2 shows a table which details the operation of the circuit of FIG. 1 with the following parameters: Bus width (M)=8, A=6, and B=10. The first row of numbers in the table shows the state of the circuit after a reset. The subsequent rows are the state of the circuit after subsequent clock rising edges, one line per clock cycle.
The left portion of the table shows the effective operation of the circuit in terms of familiar decimal arithmetic. Upon reset, the value I and the circuit output are set to zero. On each clock rising edge, the value of I is updated by adding to it the value labeled Delta in the table. Delta is a mathematical representation of the combination of output 54 of multiplexer 44 and carry-in input 56, and is equal to -A if the current output is a zero and equal to B if the output is a one. The output after any given clock edge is zero if I is greater than or equal to zero and 1 if I is less than zero.
The middle portion of the table shows these same operations in terms of two's complement arithmetic. This is the actual operation of the circuit hardware. In two's complement arithmetic, negative numbers are represented by digital words whose most significant bit is set. In an 8-bit implementation, digital words whose hexadecimal values are between 80 and FF are interpreted as negative numbers. Addition of two's complement numbers is the same as decimal addition, however subtraction of two two's complement numbers U and V is implemented as U+V-bar+1.
The J column plays the same role as the Delta column in the decimal portion of the table. The value of J is selected based on the current output, and the Carry-In column provides the extra 1 for two's complement subtraction when A-bar is selected. The operation of the circuit hardware is always: (new I)=(old I)+J+Carry-In, which adds to and subtracts from I as appropriate. The Carry-Out of this add operation is zero when the resulting value is negative, and one when the resulting value is positive or zero. The Carry-Out signal is used to produce the proper circuit output for each clock cycle. Note that because the Carry-Out value is saved along with the 8 bits of I, the result of the addition is effectively 9 bits wide. This allows an 8-bit implementation for example to work properly for all values of A and B such that 00<=A<=FF, 00<=B<=FF.
The right portion of the table shows the main and auxiliary outputs of the circuit for each clock cycle. Note that the first output after a reset is a one, the last output in a "pattern" is a zero, and in every 16 cycles there are 6 ones and 10 zeros, maximally spread apart. Also note that the length of the unique portion of the output pattern is 8. The greatest common divisor of A and B (gcd(A,B)) for this case is 2. The pattern length is therefore (A+B)/gcd(A,B)=16/2=8.
FIG. 3 shows several example applications of the present invention. FIG. 3a shows the use of the spreader for rational number clock division. The circuit consists of a spreader 84, an exclusive-OR gate 86, and a flip-flop 88. Exclusive-OR gate 86 and flip-flop 88 combine to form a "toggle flip-flop" 90. Each time the spreader output 92 is a one, the state of the output clock signal 94 will invert. The desire is to spread out these output clock transitions as much as possible while maintaining a specified number of transitions per second. As indicated in the diagram, the frequency of the clock produced by the circuit is related to the source clock frequency by the ratio A/2(A +B).
FIG. 3b shows the application of the spreader to data stuffing. The circuit consists of a spreader 96, two First-In-First-Out (FIFO) buffers 98 and 100, a digital inverter 102, and a 2:1 multiplexer 104. The circuit is configured such that when the spreader output 106 is a one, a "real" data bit is clocked out of its buffer and presented at the output. When the spreader output 106 is a zero, a "dummy" data bit is clocked out of its buffer and presented at the output. Because the ones and zeroes out of the spreader are maximally spread, so also will the real and dummy data be maximally spread. For example, if the real input data rate is 17 kbps and the desired combined stuffed data rate is 25 kbps, then the appropriate configuration values are A=17, B=8.
FIG. 3c shows the application of the spreader to the programmable generation of a precise voltage level. The circuit consists of a spreader 108, a buffer amplifier 110, a resistor 112 and a capacitor 114. The buffer amplifier 110 produces a known voltage level Vref at its output 118 when the output 116 of the spreader is a one, and zero volts at its output 118 when the output 116 of the spreader is a zero. Resistor 112 and capacitor 114 are configured as a low-pass filter to average the resulting waveform 118. The result is that Vout 120 will be a DC voltage level (with a small amount of AC ripple) equal to Vref times the duty cycle of the signal at output 116 of spreader 108. This duty cycle is equal to A/(A+B).
From the foregoing, those skilled in the art should realize that the present invention provides a simple yet flexible way to produce useful serial binary patterns and which further enables the user to change the pattern by simply changing the digital words latched into the configuration section of the device. A large variety of waveforms can be produced if a programmable device, like a microprocessor, is used to configure the device. As noted at the outset, the invention has been described in connection with a few particular examples. However, various modifications and other applications will become apparent to the skilled practitioner after having the benefit of studying the specification, drawings, and the following claims. | The disclosed invention is a digitally configurable sequential logic circuit which produces serial binary data patterns. The circuit is configured by specifying two non-negative integers A and B. For given values of A and B, the circuit produces a serial binary data pattern with the following properties: 1) in every consecutive (A+B) bits of the pattern, there are A ones and B zeros, 2) the ones in the pattern are maximally spread apart from one another, and 3) the zeros in the pattern are maximally spread apart from one another. The patterns so produced are useful in a variety of applications. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a wet process type hard fiberboard used, for example, as a building interior material, curing material or automobile interior material, and more particularly, to an environmentally-friendly wet process type hard fiberboard in use of an acrylic resin and an epoxy resin not containing bisphenol A as a reinforcing agent.
[0003] 2. Description of the Related Art
[0004] A wet process type hard fiberboard (also simply referred to as “hardboard”) is a fiberboard made primarily from wood chips by steaming and pulping the fibers followed by dispersing in a large volume of water to obtain a pulp slurry, adding a reinforcing agent and water-resisting agent, dehydrating and forming to a constant thickness, and hot-pressing to a density of 0.80 g/cm 3 or more. Although wet process type hard fiberboard reinforcing agents conventionally included phenol resins, melamine resins, urea resins and starch, since the effects of phenol resins in particular were also remarkable in terms of water resistance in addition to strength, phenol resins came to be used nearly exclusively.
[0005] However, spurred on by recent environmental issues, there was a growing concern over the effects of phenol resins on the environment (odor and residual phenol), policies were adopted preventing the use of wet process type hard fiberboards due to the use of phenol resin as one of the raw materials thereof, even if used in only trace amounts such that the amount of residual phenol was essentially zero.
[0006] At the same time, there was a growing movement towards improving the environments in wet process type hard fiberboard factories, in order to realize this, it was necessary to eliminate phenol resins, which were the primary source of contamination of wet process type hard fiberboard factories.
[0007] This is because phenol resins contaminate the pulp slurry used in wet process type hard fiberboards, and this becomes adhered to equipment and floors, thereby considerably harming the surrounding environment.
[0008] Despite these underlying circumstances, since it was not easy to find an alternative reinforcing agent for wet process type hard fiberboards, phenol resins had been inexpensive and made it possible to easily allow the obtaining of required levels of board performance for a long time, and since phenol resins had been highly valued and been used nearly exclusively, there has been little research conducted on reinforcing agents to take the place of phenol resins.
[0009] Examples of known technologies relating to reinforcing agents as described above are listed in the patent publications below. The technology disclosed in Japanese Patent Application Laid-open No. 2003-39413 is a method for compressing a wet process type hard fiberboard using an adhesive such as phenol resin having formaldehyde as one of the raw materials thereof for the reinforcing agent by putting into an impregnated state followed by subjecting to a high temperature and high-pressure pressing.
[0010] In addition, Japanese Patent Application Laid-open No. 2008-80714 discloses a method for providing a wet process type hard fiberboard enabling formaldehyde and acetaldehyde to both be effectively captured and decomposed by permeating and solidifying an aldehyde capturing agent at least containing carbodihydrazide within one side or both sides of the wet process type hard fiberboard using an adhesive such as phenol resin having formaldehyde as one of the raw materials thereof as a reinforcing agent.
[0011] In addition, Japanese Patent Application Laid-open No. H07-214518 discloses a method for increasing the strength, bindability and water resistance of a mat surface by coating an acrylic emulsion and the like onto a formed mat to which thermosetting resin has been added prior to a hot pressing step.
[0012] In addition, Japanese Patent Application Laid-open No. 2006-7534 discloses a method for producing an environmentally-friendly cellulose-based fiberboard in which, although lignin is conventionally hardly used at all for pulp since the objective is the use of cellulose, an attempt was made to use such a lignin-based raw material by using a multifunctional compound as a reinforcing agent (a polyepoxy compound is described as a compound having rapid-curing properties by hot pressing superior to those of phenol resin, and phenol novolak is listed as an example thereof).
[0013] In addition, Japanese Patent Application Laid-open No. 2007-118261 discloses a method for obtaining a wood fiberboard having ant-repelling and insect-repelling performance by adding an adhesive such as phenol resin or epoxy resin containing a neonicotinoid-based compound during the course of producing a wood fiberboard.
[0014] In addition, Japanese Patent Application Laid-open No. 2005-280030 and Japanese Patent Application Laid-open No. 2005-288713 disclose methods for producing a hard fiberboard having superior dimensional stability, water resistance, scratch resistance and impact resistance during the course of producing a hard fiberboard containing mineral fibers that is not a wood hard fiberboard by using a phenol resin, acrylic emulsion or epoxy resin and the like as a binder, carrying out wet forming and drying to obtain a semi-cured mat, and impregnating the semi-cured mat with an acrylic emulsion and the like followed by hot-pressing. Furthermore, since the acrylic emulsion disclosed in these patent references cures at a low temperature of 80 to 110° C., it is judged to be a thermoplastic resin and not a thermosetting resin in the manner of the present invention.
[0015] Moreover, Japanese Patent Application Laid-open No. 2001-200497 discloses a method for producing a fiberboard having adequate strength without causing large variations in the electric charge balance of a fiber dispersion during the course of producing a wet process type soft fiberboard (also referred to as insulation board in the form of a wet process type fiberboard having a density of less than 0.35 g/cm 3 ) by combining the use a water-soluble polymer having a cationic group and a water-soluble polymer not having a cationic group as reinforcing agents.
[0016] The technologies described in above-mentioned patent publications have difficulty in providing an environmentally-friendly wet process type hard fiberboard, which is an object of the present invention. This is because the technologies described in the first seven patent publications do not preclude the possibility of using a conventional phenol resin, while the technology of Japanese Patent Application Laid-open No. 2001-200497 relates to the production of a wet process type soft fiberboard instead of a wet process type hard fiberboard, thereby not only preventing the ensuring of adequate water resistance required by such fiberboard, but also enhancing the possibility of the occurrence of spotting defects in terms of appearance as well.
SUMMARY OF THE INVENTION
[0017] In consideration of the circumstances as described above, an object of the present invention is to provide an environmentally-friendly wet process type hard fiberboard by finding a reinforcing agent not having an effect on environmental contamination to take the place of phenol resin having a significant effect on environmental contamination.
[0018] In order to achieve this object, the environmentally-friendly wet process type hard fiberboard according to the present invention is comprised of an acrylic resin and an epoxy resin not containing bisphenol A as reinforcing agents.
[0019] Here, although the wet process type hard fiberboard refers to a fiberboard made primarily from wood chips by steaming and pulping the fibers followed by dispersing in a large volume of water (recent wet process type hard fiberboards use recycled water for the water in consideration of protecting the environment, and the temperature of the water is ordinarily 40 to 60° C. and does not exceed 100° C.) to obtain a pulp slurry, adding a reinforcing agent and water-resisting agent, dehydrating and forming to a constant thickness, and hot-pressing to a density of 0.80 g/cm 3 or more, bamboo or bagasse and the like may be used for the main raw material in addition to wood chips.
[0020] Although phenol resin has conventionally been used nearly exclusively for the reinforcing agent of this fiberboard, since this resin contaminates the pulp slurry, in addition to harming the surrounding environment, there are also concerns over the resulting odor and residual phenol.
[0021] Therefore, as a result of conducting extensive research, the inventors of the present invention reached the conclusion that a combination of acrylic resin and epoxy resin not containing bisphenol A is preferable as reinforcing agents free of such concerns.
[0022] Both reinforcing agents are thermosetting resins, are virtually unreactive at temperatures of 100° C. or lower, become highly reactive and undergo curing when the temperature exceeds 140° C., and in terms of environmental protection, since hardly any of the water used is discharged to the outside, these reinforcing agents are optimally suited for use in wet process type hard fiberboards in which water is used by recycling numerous times.
[0023] Namely, when phenol resin is exposed for a long period of time in pulp water at 40 to 60° C. or is subjected to mechanical dehydration during hot-pressing (maximum 100° C.), pre-curing (curing rate increases the higher the temperature) proceeds resulting in a state in which inherent board performance is unable to be imparted. Thus, the pre-curing product (since the yield of reinforcing agent and water-resisting agent is typically considered to be about 50% in the case of a wet process type hard fiberboard, the remaining 50% is recycled thereby eliminating any opportunity for subsequent yield) binds directly with pulp or binds directly with phenol resin thereby impairing the inherent performance of the phenol resin or having negative effects on board performance by being interposed between the pulp and fresh phenol resin. In contrast, since both of these reinforcing agents do not undergo pre-curing at such temperatures and are only cured during hot-pressing (180 to 220° C.), pre-curing products do not form and there are no negative effects on board performance.
[0024] In addition, since pre-curing products of phenol resins have a blackish-purple color, have adhesiveness when containing moisture and easily peel when dry, they cause considerable contamination of the surrounding environment and surrounding equipment. In contrast, since the reinforcing agents of the present invention are transparent do not undergo pre-curing until hot-pressing, the surrounding environment and surrounding equipment are kept clean.
[0025] Moreover, although hot-pressing of a wet process type hard fiberboard is ordinarily carried out by a three-stage closing process as will be described later, a large amount of moisture is discharged from the mat (that resulting from dehydration and forming of a pulp slurry to a constant thickness with a forming machine as will be described later) during mechanical dehydration of the first stage. Although reinforcing agent and water-resisting agent are contained in this moisture, in the case the reinforcing agent is phenol resin in particular, due to the blackish-purple color of the resin and as a result of having considerable adhesiveness when in the state of containing moisture, not only does the resin considerably contaminate the surrounding environment and surrounding equipment if it becomes adhered to the equipment and environment as previously described, since it also significantly contaminates the mirrored surface plate (stainless steel plate) used to obtain a smooth surface for a wet process type hard fiberboard, it ends up shortening the replacement and cleaning cycles of the mirrored surface plate.
[0026] In contrast, since the reinforcing agents of the present invention are transparent and do not undergo pre-curing even if discharged during hot-pressing and dehydration, not only are the surrounding equipment and surrounding environment kept clean, but the replacement and cleaning cycles of the mirrored surface plate can be extended considerably.
[0027] As can be understood from the above-mentioned explanation, the use of the acrylic resin and bisphenol A-free epoxy resin of the present invention as reinforcing agents of a wet process type hard fiberboard makes it possible to obtain a wet process type hard fiberboard that is much more environmentally-friendly than the use of a conventional reinforcing agent in the form of phenol resin.
[0028] However, the acrylic resin of the present invention is preferably a polymer having a carboxylic acid to induce thermal crosslinking, examples of which include polymers having for monomers thereof acrylic acid, methacrylic acid, maleic acid, fumaric acid or itaconic acid, and salts thereof.
[0029] In addition, examples of the bisphenol A-free epoxy resin of the present invention include reaction products of bisphenol F and epichlorohydrin, reaction products of bisphenol AD and epichlorohydrin, reaction products of polyamine and epichlorohydrin, reaction products of acetic anhydride and epichlorohydrin, reaction products of phenol novolak and epichlorohydrin and reaction products of ortho-cresol and epichlorohydrin.
[0030] Incidentally, epoxy resin containing bisphenol A is a reaction product of bisphenol A and epichlorohydrin.
[0031] Furthermore, in the present invention, epoxy resin containing bisphenol A has been excluded from the scope of the present invention for the reasons indicated below.
[0032] Reason 1: Although epoxy resin containing bisphenol A is the most common type of epoxy resin, bisphenol A remaining in this epoxy resin results in the problem of having the action of an environmental hormone.
[0033] Reason 2: Epoxy resin containing bisphenol A is frequently in the form of a two-liquid type combining a primary agent and a curing agent, making it unsuitable for use as a reinforcing agent of a wet process type hard fiberboard. Namely, since mixing of a two-liquid type immediately causes curing to begin, in addition to not obtaining the necessary board performance during hot-pressing, as a result of the reaction product being suspended in the recycled white water, there is also a high likelihood of the occurrence of appearance defects in the resulting hard fiberboard in the form of spots and the like. Incidentally, the bisphenol A-free epoxy resin of the present invention is of the one-liquid type.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 shows the front side of a wet process type hard fiberboard in the examples; and
[0035] FIG. 2 shows the rear side of a wet process type hard fiberboard in the examples.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] FIG. 1 shows a wet process type hard fiberboard 10 .
[0037] Although a front side 1 of the hard fiberboard is smooth, a rear side 2 is in the form of a mesh 3 as shown in FIG. 2 as a result of facing a wire mesh for facilitating dehydration in a hot-pressing step to be described later. The following provides a detailed description of this hard fiberboard.
[0038] (Slurry Preparation)
[0039] Although the pulp used consists mainly of wood for the raw material, it may also be made from bamboo or bagasse.
[0040] Mechanical pulp, in which pulping is carried out by mechanical treatment, chemical pulp, in which pulping is carried out by chemical treatment, or semi-ground pulp, in which pulping is carried out by a combination of mechanical treatment and chemical treatment, can be used for the raw material. This pulp is normally in the form of a slurry by dispersing in water at a concentration of about 3% by weight.
[0041] Next, the slurry is prepared by adding the acrylic resin and bisphenol A-free epoxy resin of the present invention as reinforcing agents so that the amount of acrylic resin is about 0.05 to 2.0% by weight and the amount of the bisphenol A-free epoxy resin is about 0.1 to 2.0% by weight based on 100 parts of pulp in the slurry, adding a water-resisting agent in the form of paraffin wax at 0.1 to 1.5% by weight based on 100 parts of pulp in the slurry, and adding preservatives or aging preventives as necessary.
[0042] Although subsequently described in detail, the amount of reinforcing agent added is most preferably 0.05 to 0.25% by weight for the acrylic resin, and 0.50 to 1.00% by weight for the bisphenol A-free epoxy resin. This is because a combination of amounts added within these ranges makes it possible to obtain the most preferable board performance.
[0043] Furthermore, in addition to paraffin wax, water repellent agents such as silicon compounds or zirconium compounds can also be used for the water-resisting agent.
[0044] (Wet Mat Preparation)
[0045] The above-mentioned slurry is ordinarily used for wet mat preparation after diluting to a pulp concentration of about 1.0 to 1.5% by weight. A known method is applied for wet mat preparation, such as a cylindrical method, Fourdrinier method or Chapman method. Regardless of the method, the slurry is run out onto a wire mesh, dehydrated from the back of the wire mesh by vacuum suction and formed into a wet mat. On the front side of this wet mat, the lengthwise direction of the pulp is oriented to be roughly in the horizontal direction, while on the rear side (metal mesh side), the lengthwise direction is oriented to as to be roughly perpendicular by vacuum suction, and pulp density is higher on the front side and comparatively low on the rear side. Moreover, the rear side has a rough surface due to printing of the wire mesh thereon. This wet mat maybe dehydrated as desired to a dryness [pulp weight÷(pulp weight+water weight)×100%] of about 30 to 40% by cold pressing.
[0046] (Hot Pressing)
[0047] The above-mentioned wet mat subsequently undergoes hot pressing. Although hot pressing is ordinarily carried out at a temperature of about 180 to 220° C., in the case of producing a hard fiberboard having a thickness of 2.5 mm, for example, hot pressing is carried out with a three-stage closing process comprising 50 to 60 seconds at a pressing pressure of 40 kg/cm 2 , 60 to 90 seconds at 8 to 10 kg/cm 2 and 60 to 90 seconds at 20 to 35 kg/cm 2 . In this three-stage closing process, by facilitating the escape of water vapor contained in the wet mat by lowering the pressure in the second stage (also referred to as a degasification process), blowout of the wet mat is prevented. Furthermore, although the pressing apparatus is equipped with an upper mold and a lower mold, by providing a spacer in the form of a wire mesh or porous plate on the surface of the lower mold, water squeezed from the wet mat is discharged.
[0048] As has been described above, since the pulp is oriented roughly perpendicular to the lengthwise direction on the rear side of the wet mat, squeezing of water from the wet mat is carried out smoothly as a result of being guided between the pulp.
[0049] (Moisture Adjustment and Curing)
[0050] Following hot pressing, the wet process type hard fiberboard is either sprayed with water or subjected to moisture adjustment treatment to adjust to a prescribed moisture content followed by curing for a fixed period of time to obtain a finished product.
Examples
[0051] The following provides an explanation of examples of the present invention by comparing with conventional reinforcing agents in the form of phenol resins.
[0052] The test pieces for measuring board performance used for testing were cut from a wet process type hard fiberboard having a thickness of 2.5 mm and size of 30 cm on a side produced with an experimental apparatus in compliance with first ten paragraphs in the Description of the Preferred Embodiments of the present invention, and the test piece for measuring bending strength measured 3 cm×11 cm (span: 6 cm), while the test piece for measuring water absorption measured 5 cm×5 cm.
[0053] Since pulp is ordinarily anionically charged, in order to increase the yield of reinforcing agent and water-resisting agent in the pulp, cationic charge is preferable in consideration of favorable reactivity with the anionic pulp.
[0054] Thus, although the paraffin wax used in a wet process type hard fiberboard is ordinarily also cationically charged, since increasing the yield of paraffin wax alone in the pulp is detrimental, it is preferably only contained in combination with other reinforcing agents. One reason for this is that the viscosity of paraffin wax is lower than that of other reinforcing agents. In other words, physical bonding in the form of viscosity contributes more greatly to yield in pulp than chemical bonding in the form of anion-cation bonding.
[0000]
TABLE 1
Bending
Water
Water-resisting
Strength
Absorption
Agent
Reinforcing Agent
(N/mm 2 )
(%)
None
None
22
85
Paraffin wax:
None
20
88
0.4%
Paraffin wax:
Phenol resin: 0.5%
31
48
0.4%
Paraffin wax:
Acrylic resin:
25
55
0.4%
0.5%
Paraffin wax:
Epoxy resin: 0.5%
52
25
0.4%
[0055] Based on Table 1, board performance was clearly the most inferior for acrylic resin among the reinforcing agents tested. A possible reason for this is that since the acrylic resin of the present invention is anionically charged, there was naturally little reactivity with the anionically charged pulp. In this case, however, board performance was better than the addition of paraffin wax alone. This is thought to be due to the anions of the acrylic resin reacting with the cations of the paraffin wax resulting in the formation of a large block, and this physically accumulated in the pulp. The reason why the values are not that good is that, because a large block is formed, dispersion in the pulp becomes poor.
[0056] On the other hand, since the bisphenol A-free epoxy resin is cationically charged, it accumulates in the pulp due to chemical bonding with the anionically charged pulp and physical bonding in the form of the viscosity inherently possessed by epoxy resin, thereby realizing board performance superior to that of phenol resin.
[0057] Table 2 shows a comparison of board performance with respect to phenol resin and bisphenol A-free epoxy resin in the case of increasing the amount of reinforcing agent added. From this table as well, the board performance of the bisphenol A-free epoxy resin can be clearly seen to be superior to that of phenol resin.
[0000]
TABLE 2
Reinforcing
Agent
Bending
Water
Amount
Strength (N/mm 2 )
Absorption (%)
added (%)
Phenol
Epoxy
Phenol
Epoxy
0.25
28
43
48
27
0.50
32
52
45
25
0.75
33
56
43
29
1.00
35
50
44
41
2.00
38
50
42
40
[0058] However, chemical bonding between bisphenol A-free epoxy resin and pulp is believed to occur by, for example, the azetidinium ring (Chemical Formula 1) of the bisphenol A-free epoxy resin reacting with the carboxyl group (Chemical Formula 2) and hydroxyl group (Chemical Formula 3) of the cellulose in the pulp in the manner indicated below. In other words, bonding between pulp fibers is believed to be strengthened by this type of reaction.
[0000]
[0059] Furthermore, in Table 2, water absorption rapidly becomes poor when the added amount of bisphenol A-free epoxy resin reaches 1.00% or more. This is thought to be due to the paraffin was precipitating accompanying the increase in epoxy resin, thereby resulting in poor dispersion of the paraffin wax due to the effect thereof.
[0060] Next, Tables 3 and 4 illustrate the effect of combining the acrylic resin and bisphenol A-free epoxy resin according to the present invention.
[0000]
TABLE 3
Bending Strength (units: N/mm 2 )
Acrylic added
Epoxy added
amount (%)
amount (%)
0.000
0.125
0.250
0.500
0.750
1.000
0.125
24
0.250
43
27
0.500
52
51
46
35
33
32
0.750
56
60
56
50
43
35
1.000
50
61
62
55
51
46
[0000]
TABLE 4
Water Absorption (units: %)
Epoxy added
Acrylic added amount (%)
amount (%)
0.000
0.125
0.250
0.500
0.750
1.000
0.125
67
0.250
27
58
0.500
25
24
24
39
47
56
0.750
29
22
23
24
36
49
1.000
41
22
22
24
25
26
[0061] On the basis of Tables 3 and 4, the effect of combining acrylic resin and bisphenol A-free epoxy resin can be judged to be apparent at ratios of the amount of acrylic resin added to the amount of bisphenol A-free epoxy resin added of 0.125:0.75, 0.125:1.00, 0.25:0.75 and 0.25:1.00. Thus, in consideration of total cost, the effect of combining acrylic resin and bisphenol A-free epoxy resin can be judged to be optimal at a ratio of the amount of acrylic resin added to the amount of bisphenol A-free epoxy resin added of 0.125:0.75.
[0062] Although a tendency for board performance to decrease as the amount of acrylic resin increased is observed in Tables 3 and 4, this is believed to be due to the effect of the degree of cohesive strength between the acrylic resin and the bisphenol A-free epoxy resin. In other words, an aggregate of the acrylic resin and bisphenol A-free epoxy resin has a strong cohesive strength, resulting in the formation of a paste as the amount of acrylic resin increases and eventually forming a large block, thereby causing a corresponding decrease in dispersibility in the pulp. This can be judged to appear in the form of a decrease in board performance.
[0063] The reason for hardly any change in water absorption even if the amount of acrylic resin is increased in the case of an added amount of bisphenol A-free epoxy resin of 1.00% is thought to be caused by the fact that, although particles of paraffin wax precipitate when the amount of bisphenol A-free epoxy resin is increased in the paraffin wax, if the amount of acrylic resin is simultaneously increased, the growth of blocks of precipitate discontinues due to the effects of limitations on the physical bonding strength of the blocks of acrylic resin and bisphenol A-free epoxy resin, thereby not leading to a decrease in dispersibility of the paraffin wax.
[0064] Next, a comparison of board performance is shown in Table 5 between the reinforcing agents of the present invention (combination of acrylic resin and bisphenol A-free epoxy resin, to be referred to as the resins of the present invention) (*2) and a conventional reinforcing agent in the form of phenol resin (*3) in the case of recycling water(*1).
*1: In the case of using water repeatedly, since the amount of water used in the next cycle is insufficient by the amount of water contained in the mat of the previous cycle, that corresponding amount (roughly 1/12 of the total amount of water) is replenished with fresh water. *2: Addition of 0.25% acrylic resin, 0.75% bisphenol A-free epoxy resin and 0.4% paraffin wax. *3: Addition of 1.0% phenol resin and 0.4% paraffin wax.
[0000]
TABLE 5
Re-
Board
inforcing
No. of Cycles Water Used Repeatedly
Performance
Agent
1
2
3
4
5
6
7
8
9
10
Bending
Resins of
50
48
49
49
53
50
54
49
52
52
Strength
Present
(N/mm 2 )
Invention
Phenol
34
40
40
41
38
39
40
42
40
42
Resin
Water
Resins of
48
41
33
30
27
27
25
26
25
26
Absorption
Present
(%)
Invention
Phenol
43
33
35
32
32
29
30
33
27
27
Resin
[0068] As is clear from Table 5, the level of board performance can be judged to be considerably superior for the reinforcing agents of the present invention as compared with the conventional reinforcing agent in the form of phenol resin with respect to bending strength in particular.
[0069] However, in recognition of the progression of environmental measures in the form of reduced VOC levels, test pieces of a wet process type hard fiberboard having a thickness of 2.5 mm (surface area: 80 cm 2 ) were prepared to investigate the degree to which resins of the present invention are superior to a conventional reinforcing agent in the form of phenol resin with respect to reducing levels of VOC. The test pieces were placed in a 10 liter Tedlar bag containing 4 liters of pure nitrogen gas and heated for 2 hours at 65° C. followed by sampling the entire 4 liters with a DNPH cartridge and measuring the level of volatile aldehydes by high-performance liquid chromatography. The results are shown in Table 6.
[0000]
TABLE 6
(units: μg/test piece)
Aldehydes
Reinforcing Agent
Formaldehyde
Acetaldehyde
Resins of Present
1.7
2.6
Invention
Phenol Resin
3.6
4.4
[0070] On the basis of Table 6, in the case of using the resins of the present invention as reinforcing agents, it is obvious that the level of aldehydes is half the case of using a conventional phenol resin as a reinforcing agent.
[0071] In addition, the testing method indicated below was carried out with respect to odor. Namely, test pieces (4 cm×7 cm) were placed in a steel drum having a volume of 4 liters followed by carrying out a dry test (consisting of covering the container and heating for 60 minutes at 80° C. followed by cooling to room temperature and smelling the odor) and a wet test (consisting of uniformly applying distilled water onto the test pieces in an amount equal to 5% the weight of the test pieces, covering the container and allowing to stand for 60 minutes in a constant temperature/constant humidity chamber at 23±2° C. and 50±5% RH followed by smelling the odor). Furthermore, in this odor test, a total of six samplers were used since a minimum of five samplers are required. Thus, two drums were prepared since the limit was 3 samplers/drum. The results are shown in Table 7.
[0000]
TABLE 7
Dry
Wet
Reinforcing
Unpleas-
Un-
Agent
Intensity* 1
antness* 1
Intensity* 1
pleasantness* 1
Resins of
1.5
−0.5
0.8
−0.3
Present
Invention
Phenol Resin
2.1
−0.8
1.4
−0.6
Reference
3 or less
−1.5 or more
3 or less
−1.5 or more
Values*2
* 1 Isovaleric acid (concentration: 10 −5 ) was used for the reference odor, the imtensity thereof was assigned a value of 3 (level at which odor can be detected easily) and a degree of unpleasantness of −2 (unpleasant). Each sampler scored the odors according to each level (intensity: 0 (odorless) to 5 (powerful odor), unpleasantness: −3 (extremely unpleasant) to 3 (extremely pleasant), and the results indicate the average scores.
* 2 Reference values
[0072] On the basis of Table 7, the use of the resins of the present invention as reinforcing agents is clearly advantageous as compared with using a conventional phenol resin as a reinforcing agent with respect to odor as well.
[0073] As has been described in detail above, since a wet process type hard fiberboard using the resins of the present invention as reinforcing agents results in hardly any contamination of water used in large amounts during production (normally referred to as white water and used by recycling) in comparison with a wet process type hard fiberboard using a conventional phenol resin as a reinforcing agent, not only can production equipment and the surrounding environment be kept clean, there is also no concern over residual phenol, there is naturally no odor of phenol, and since aldehyde levels are also reduced in addition to being able to prevent problems attributable to odor in advance, this wet process type hard fiberboard is also able to contribute to reduction of VOC. Namely, a wet process type hard fiberboard using the resins of the present invention as reinforcing agents is naturally able to be much more environmentally-friendly than wet process type hard fiberboard using a conventional phenol resin as a reinforcing agent, while also enabling board performance that is superior to a wet process type hard fiberboard using conventional phenol resin as a reinforcing agent.
[0074] Embodiments of the present invention have been set forth in the above description with reference to the appended figures. However, the present invention is not limited to the above-described embodiments, and variations and modifications may be made without departing from the scope of the present invention. | A wet process type hard fiberboard is provided that is environmentally-friendly by finding a reinforcing agent that does not result in environmental contamination as the agent takes the place of phenol resin having a significant effect on environmental contamination. This environmentally-friendly wet process type hard fiberboard uses acrylic resin and epoxy resin not containing bisphenol A as reinforcing agents in place of conventional phenol resin. Both reinforcing agents are thermosetting resins, hardly reacting at all at temperatures of 100° C. or lower, and reacting rapidly at temperatures above 140° C. which results in curing, while in terms of environmental protection, these reinforcing agents are optimally suited for use in wet process type hard fiber boards in which water is used by recycling numerous times, with any of the water used being hardly discharged to the outside. | 3 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This is a continuation-in-part application that claims the benefit of U.S. patent application Ser. No. 12/389,320, filed Feb. 19, 2009 and entitled “Lateral Support Craniocervical Orthosis and Method,” which is a continuation-in-part application that claims the benefit of U.S. patent application Ser. No. 11/446,402, filed Jun. 8, 2006 and entitled “Headrest and Method for Correcting Non-Synostotic Cranial Deformities in Infants.” Each of these applications is incorporated by reference herein.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates generally to a craniocervical orthosis in which an infant's cranium is positioned while the infant is sleeping to prevent and correct cranial deformities. More specifically, the invention relates to a craniocervical orthosis and method for preventing and correcting any non-synostotic deformity of the side and posterior aspects of an infant's head.
[0005] 2. Background of the Invention
[0006] At birth, the six cranial bones comprising an infant's skull are spaced far enough apart to allow the skull to rapidly grow during the first months of the infant's life. This spacing also allows the bones to overlap so the infant's head can pass through the birth canal without compressing, and thereby damaging, the infant's brain. Eventually—some time between three and six years of age—the cranial bones will fuse and remain fused for the rest of the child's life.
[0007] During an infant's normal growth, forces within the infant's skull are directed outward and are constant and equally distributed on the inner surface of the growing skull causing the skull to expand. Accordingly, a decrease of the intracranial pressure will cause a reduced head size. Similarly, an increase in intracranial pressure will cause an increased head size.
[0008] Fibrous bands of tissue, called cranial sutures, fill the space between the bones and connect the bones of the skull to each other. These cranial sutures are strong and elastic, providing a flexibility to the skull to allow rapid brain growth during the first months of life. Without the sutures, a child would suffer brain damage due to constriction of the brain during the period of normal growth.
[0009] During the first few months of an infants' life, however, the infant is most susceptible to the formation of synostotic or non-synostotic deformities in the cranium. Synostotic deformities are a result of craniosynostosis, which is a birth defect of the skull characterized by premature closure of one or more of the cranial sutures. Craniosynostosis can be hereditary or the result of a metabolic disease, and is characterized by an abnormally-shaped skull and potential for abnormal intracranial pressure, mental retardation, seizures, and blindness.
[0010] On the other hand, non-synostotic deformities, in which the cranial sutures remain open, are caused by environmental conditions, including premature birth, torticollis (twisting of the neck muscles beyond their normal position), or the preferred sleeping position of the child. In addition, neurological abnormalities, such as paralysis, cerebral palsy, or some sort of developmental delay, may predispose a child to cranial positioning problems. Non-synostotic deformities are also called positional deformities.
[0011] Synostotic and non-synostotic deformities manifest themselves in a variety of ways. Plagiocephaly, for example, is a cranial deformity resulting in an asymmetric head shape. Plagiocephaly consists of a focal area of flattening in the anterior or posterior aspect of one side of the head, which also commonly produces additional compensatory deformities in adjacent areas of the skull, skull base, and face, including the orbital (eye) and mandibular (jaw) structures. This deformity most commonly occurs in the posterior aspect of the head (posterior plagiocephaly), resulting in a focal area of flattening on that side and a compensatory prominence, or bulge, on the other side. In addition, the deformity produces anterior displacement of the ear, ear canal, temporomandibular (jaw) joint, forehead and orbital structures on the same side. Cranial deformities may also be classified, inter alia, as brachycephaly (a short, wide head shape), scaphocephaly (a long, narrow head shape), and turricephaly (a pointed head shape).
[0012] Non-synostotic posterior plagiocephaly is a very common problem for which parents seek evaluation and recommendations from their family physician or pediatrician. The incidence of this abnormality has increased significantly since publication of recommendations by the American Academy of Pediatrics that neonates (infants) should be put to sleep on their back rather than face down. These recommendations were made to reduce the incidence of Sudden Infant Death Syndrome (SIDS) by eliminating airway and respiratory compromise in the prone (face-down) position, which the Academy considered a possible contributor to the SIDS problem.
[0013] Brain growth is responsible for the growth and shaping of the skull, which results from slow, gradual separation of the bones at the cranial sutures. This separation allows for the addition of new bone onto the peripheral edges of the existing bone, producing gradual bone enlargement and reshaping of each bone. As the head enlarges, new bone is added to each bone in an inwardly directed fashion producing an inner surface concave shape to the overall bone. Any force or pressure applied to the exterior surface of the bone will re-direct the growth of bone added to the edges. New bone will be added in a more linear direction, thus reducing the inner surface concavity or producing “flattening” of the bone. Growth of bone does not stop; rather, it is redirected. Therefore, externally applied pressure (e.g., contact with an orthosis) reduces or stops outward growth or migration in that area, and redirects the growth to occur in a direction that is perpendicular to the applied force, which is tangential to the bone surface in that location. Uniform expansion of the remaining bones and sutures, which comprise the cranial vault, is rare. Instead, relative increased growth and expansion of the areas most adjacent to the “flattened” area tends to occur.
[0014] Treatment may come in the form of prevention or correction. Regarding prevention, the focus should be to reduce the duration that external pressure is applied to a localized area of the skull. This can be accomplished by moving the same external force to different areas of the skull. This is only achievable by re-positioning the patient's head, which is not possible in a large number of infants (e.g., those having immobility from torticollis). An alternative way to accomplish this is to enlarge the surface area of contact, which reduces the amount of pressure on the specific area, although it still typically results in at least some contact at the area of desired growth. It is also important to restrict the compensatory overgrowth that forms abnormal prominent areas in locations that are perpendicular and adjacent to the area of applied force. This allows for re-direction of growth and expansion in an appropriate normal direction. Devices used for prevention must maintain these properties, but still allow for expected progressive growth.
[0015] Prolonged immobility of the head will eventually lead to the development of a positional deformity. The etiology of the immobility may be neurologic/developmental, muscular, skeletal (vertebral) or simply from resting/sleeping preference in the absence of any known cause. Persistent immobility will allow for lateral and posterior deformities to develop.
[0016] Despite public knowledge and education regarding the development of these deformities and preventative measures, because infants are usually born with normal head shapes, it appears economically irrational to go through the expense and trouble of obtaining a preventative device if no deformity appears to be present. Development of these deformities is insidious, slowly occurring over weeks and easily overlooked. Frequently, only when the condition is obvious is intervention considered.
[0017] Treatment by “repositioning,” also called “mobilization”—that is, the act of another person moving the infant's head from side to side at regular intervals—is ineffective for treating or preventing these deformities due to the inherent problems associated with such a method of treatment. Simply put, it is very difficult to keep the child's head in the same position for extended periods of time, as the natural inclination of the child is to revert to his or her preferred sleeping position. Moreover, because “mobilization” is ideally performed every two to three hours, the infant requires constant attention throughout the night, and it is therefore not a practical treatment option. Similarly, children with torticollis cannot be effectively “mobilized” due to the tendency of the head to rotate as a result of involuntary contraction of the neck muscles. In both of these cases, the resulting position of the head—whether by preference or immobility—is most likely not the desired position for correction of deformities and is, as noted above, the cause of deformity in the first place.
[0018] To the extent treatment by repositioning might be effective when the above-referenced parameters are satisfied—i.e., a child who does not tend to revert to a preferred sleeping position and is not immobilized due to torticollis, and who can be mobilized regularly every two to three hours—children treated with prevention in this manner still do not obtain a perfectly normal head shape, because the supporting apparatus remains in contact with the skin and conforms the head to an abnormal shape. As a result, forces still act on already-flattened regions of the cranium and inhibit growth at precisely the area of the cranium where growth should be promoted. Due to this ineffectiveness, a large number of these children require additional treatment from five to ten months of age to correct persistent or progressive deformities.
[0019] The most common adjuncts available to assist with repositioning are flat- and wedge-shaped foam pads. For example, U.S. Pat. No. 6,473,923 (filed Nov. 22, 2000) (issued Nov. 5, 2002) discloses a body pillow and head positioner attached to a mat. The device is intended to maintain the infant's supine position—i.e., lying on the back, face upward—while reducing the risk of positional plagiocephaly by causing the head to rotate to the side while maintaining the infant's supine position.
[0020] One goal for correction of an existing deformity is to eliminate the external forces acting on the flattened area. As with prevention, improved correction can be achieved by providing external forces acting on the compensatory prominent areas of the skull, thereby reducing growth that occurs in these areas and redirecting growth towards a more normal direction and shape. Allowances for growth are also required for correction, but cannot compromise the mechanical ability of a device to correct the existing deformity.
[0021] Corrective treatment most often is by application of a custom-made external orthosis, or helmet. See, e.g., Corrective Infant Helmet, U.S. Pat. No. 6,592,536 (filed Jan. 7, 2000) (issued Jul. 15, 2003); Therapeutic and Protective Infant Helmets, U.S. Pat. No. 4,776,324 (filed Apr. 17, 1998) (issued Oct. 11 1998). Such devices provide an expanded area over the site of the deformity, thereby allowing for correction of the deformity over a three to six month period of time related to brain and skull growth and subsequent reshaping. This prolonged time of use is necessary because of the reduced rate of brain and skull growth during the six- to twelve-month time frame. Due to a decrease in the rate of brain and skull growth to approximately fifty percent of the rate from birth to six months and increased stiffness of bones and cranial sutures, the recommendation is to wear the helmet continuously for twenty-three hours each day for up to twelve months. But despite extended use of these helmets, deformities rarely return to a normal shape. In addition, many health insurance companies and programs refuse to pay for these devices, leaving a large number of infants with no available treatment because of the relatively high cost of the helmets.
[0022] Similar to the preventative approaches discussed supra, another proposed approach to correct existing cranial deformities is to soften the material on which the infant's head rests by using a foam pad or memory foam pillow. This method allows the redistribution of inwardly directed forces, but fails to adequately correct cranial deformities because the softened material conforms to the already-abnormal head shape. Specifically, the material still contacts, and therefore applies forces to, the already flattened areas of the head and reduces forces that should be applied at the abnormal cranial bulges. Preventing cranial deformities with this approach is also ineffective because forces continue to act directly on a focused area of the head rather than the entire cranial vault. Because these pads and pillows are not shaped like a normal infant cranium, but are generally flat, forces acting on the cranium from these devices result in cranial flattening, and therefore an abnormal head shape, because the head conforms to the shape of the material (i.e., flat) at the point of contact.
[0023] Still another approach is to suspend the infant's head on a flexible material, which, for example, may be a net with an open weave that keeps the infant's head slightly elevated over the resting surface. See Method and Apparatus to Prevent Positional
[0024] Plagiocephaly in Infants, U.S. Pat. No. 6,052,849 (filed Mar. 18, 1999) (issued Apr. 25, 2000). Although the use of an elastic stretchable material or netting may be slightly better than regular foam for preventing the development of flattened areas, these devices also do not effectively promote normal shaping due to the continuous application of external forces directed at the posterior aspect of the infant's head. In the case of correction, the flexible material will still conform to the already-abnormal head shape and exert forces on the flattened areas. In the case of prevention, the weight of the cranium on the flexible material will tend to immobilize the cranium, which results in prolonged contact of non-uniform forces around the cranium and, again, is precisely the wrong methodology for maintaining an already normal cranial shape. As with the “softened material” approach previously described, forces acting on a smaller area of the head results in reduced cranial growth and expansion because the head conforms to the shape of the material, thus resulting in an abnormal head shape in which the frontal areas are wider than the posterior aspect of the head because the material is applied only to the posterior aspect of the cranium, with the application of constricting forces.
[0025] After ten to twelve months of age, little, if any, correction of a cranial deformity can be accomplished with non-operative treatment because of reduced velocity of brain and skull growth, increased thickness of bone, and reduced flexibility of the cranial sutures. Surgical intervention is typically the only effective treatment for moderate to severe deformities in children over twelve months of age.
[0026] Alternative methods for correcting this condition without the use of a helmet do not directly address the cause of the problem, and therefore do not effectively treat the condition. All other products and devices, including foam, elastic (and therefore flexible) material or netting, merely distribute or disperse forces over a focused area of the head Because these products and devices remain in continuous contact with the skin, they conform the cranium to the abnormal shape, including the abnormally flattened areas. Thus, the prior art does not remove or eliminate the external forces at flattened areas of the cranium, but rather maintains an abnormal cranial shape and promotes a static deformity.
[0027] Finally, attempts to prevent and correct such deformities with the use of headrests also exist. With the exception of the present invention and U.S. Pat. No. 4,195,487 (issued May 2, 1989) to Eber1 (hereinafter “Eber1”), the existing headrests are “low profile” devices, which extend only a maximum of 35 mm anterior of the most posterior position of contact with the infant's skull (about 30% or less of the anterior-posterior distance) and only contact the very or most posterior area of the head. See, e.g., WO 2006/102407 (published Sept. 28, 2006); European Patent No. EP 1 665 958 (filed Aug. 25, 2004); New Zealand Patent No. 510,421 (filed Mar. 8, 2001). However, the low profile (i.e., posterior only) headrests are ineffective based on bio-mechanics of such devices, as lateral support is necessary in order to achieve effective prevention and treatment
[0028] These available and proposed low-profile devices provide insufficient support and positioning to overcome the problem of immobility leading to development and progression of positional deformities. These deformities develop despite any differences or modifications in shape, size, or consistency—that is, prevention or any level of correction with low profile devices will require turning of the head, and any prevention or correction achieved would be due to “repositioning” treatment as described supra, thus making the device unnecessary. The treatment provided in this situation is repositioning, not the low profile device. And as noted above, the ability to reposition or turn the head is a luxury and is not possible in a large number of instances. Lateral support, however, allows one to overcome the problem of immobility, which is not achievable with a low-profile device.
[0029] While Eber1 would not be considered a “low profile device” as discussed supra, it also provides insufficient lateral support. As shown in FIG. 4 and FIG. 5 of Eber1, the sidewalls are outwardly angled from the longitudinal axis of the device, which inherently means Eber1 provides no immediately adjacent lateral support when the infant's cranium is rotated in either direction. In this manner, Eber1 is effectively the same as the low-profile devices, but with an added disadvantage that the Eber1 sidewalls are excessively high such that a very young infant placed on the Eber1 invention is susceptible to the development of obstructive amblyopia due to the obstruction of the visual field/pathway. In addition, Eber1 is made from soft, conforming material, which, as noted with respect to foam mattresses and pads, conforms to an abnormal head shape.
[0030] Currently there is no specific apparatus available to provide effective corrective and preventative treatment for non-synostotic cranial deformities in the age range of birth to five months. To avoid the difficulties and pitfalls associated with currently available devices aimed at treating non-synostotic cranial deformities, the present invention discloses a corrective headrest for use at the very first recognition of development of a deformity. The headrest and method allow effective treatment during the rapid period of brain and skull growth (birth to six months), thereby providing rapid correction of the deformity. Children with predisposing conditions may require prolonged treatment. Early effective treatment is the key to providing complete correction of these deformities.
BRIEF SUMMARY OF THE INVENTION
[0031] The present invention discloses, inter alia, a device and method for correcting and/or preventing an infant's abnormally-shaped cranium by applying external forces over time with the growth of an infant to achieve normal shaping of the infant's head. Unlike the prior art, the present invention both 1) prevents abnormal shaping of an infant's cranium by causing even growth of the infant's normally shaped head and 2) provides forces that act unevenly across an abnormally shaped cranium to correct existing cranial deformities. The embodiments of the present invention include a solid, one-piece headrest structure of uniform consistency, having a depression that is molded to approximate the posterior and side aspects of the skull and head, with cervical, or neck, support. The material that contacts the infant's cranium is semi-rigid and relatively non-flexible, maintains its overall shape under stress, and demonstrates minimal superficial focal elasticity only at the site of cutaneous contact. In the preferred embodiment, the hardness of the material the contacts the infant's cranium is between 65 and 75 (inclusive) on a OO durometer scale.
[0032] To correct existing cranial deformities, the present invention applies inwardly-directed external forces only to areas of bony prominence and minimizes (or altogether eliminates) these forces on the areas of the skull that are less prominent (or flattened). The present invention is non-conforming to the shape of an abnormal skull. The forces exerted allow for accelerated expansion of the skull in the less prominent (flattened) areas coincident with brain and skull growth, allowing for return to a normal symmetric cranial shape.
[0033] In addition, the headrest prevents development of abnormal cranial shaping by providing a round, normally-shaped contour for contact with the posterior and side aspects of the head, even if the head is turned slightly to one side or the other. Moreover, because the surface is semi-rigid, the surface will allow for even cranial growth over this area of contact, thereby maintaining the infant's normal head shape.
[0034] The preferred embodiment of the present invention is made from an impermeable high-density foam, which provides ease of cleaning as well as flame retardant properties. Other embodiments of the present invention are made from other foam variants, including open cell foam covered with a vinyl or other coating or closed cell foam layered over or applied to more rigid solid or hollow plastic (e.g., PVC or nylon).
[0035] Therefore, in accordance with one aspect of the present invention, a headrest having a semi-rigid body for correcting the shape of an infant's abnormally-shaped cranium includes a bottom surface for contact with a resting surface; a top surface for contact with the cranium of the infant; a generally hemi-ellipsoidal depression in the top surface; and a ridge at one end of the depression for supporting the neck of the infant. The shape of the depression corresponds to the shape of a normal infantile cranium. The top surface provides external forces acting on abnormal cranial bulges of the infant's cranium and eliminates external forces that act on abnormal cranial depressions of the infant's cranium.
[0036] Other features of the headrest include a rim that defines a substantial portion of the depression, as well as the headrest having a side surface between the bottom surface and the top surface. Furthermore, an additional feature of the headrest includes a curved front surface that cradles the shoulders and further supports the neck of the infant.
[0037] According to another feature of the present invention, antero-lateral support provided by the present invention is clearly innovative in its ability to provide treatment from birth to ten months of age while not requiring any enlargement, change, or modification during this period of time. Specifically, according to this feature of the invention, lateral support is provided in conjunction with an anatomically correct shape. Elevated lateral support surfaces allow for continued growth from birth to approximately ten months of age while maintaining or producing a normal head shape, and no change, modification, or enlargement is required for approximately the first year. Because of the lateral support surfaces, the present invention is not only able to correct deformities, but also prevents them from occurring. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0038] FIG. 1 is a perspective view of the preferred embodiment of the present invention.
[0039] FIG. 2 is a frontal view of the preferred embodiment of the present invention.
[0040] FIG. 3 is a sectional view of the craniocervical orthosis along Line 3 - 3 of FIG. 2 .
[0041] FIG. 4 is a sectional view along Line 4 - 4 of FIG. 2 .
[0042] FIG. 5 and FIG. 6 depict dimensions of a preferred embodiment of the orthosis.
[0043] FIG. 7A and FIG. 7B are a rear elevational view and a top elevational view, respectively, of a normally-shaped infant cranium showing the surface area that contacts the headrest when the infant's head is supinely positioned in the orthosis.
[0044] FIG. 8A is a chart showing head circumference-for-age of males from birth to thirty-six months.
[0045] FIG. 8B is a chart showing head circumference-for age for females from birth to thirty six months.
[0046] FIG. 9A and FIG. 9B show infant craniums of approximately 36.5 and 46.5 cm in circumference, respectively, positioned in the preferred embodiment.
[0047] FIG. 10 is a partial sectional view of the preferred embodiment of the present invention with an infant having a normally shaped cranium is positioned on the contact surface of the headrest.
[0048] FIG. 11 is a partial sectional view of the headrest through the inclined first plane of FIG. 10 .
[0049] FIG. 12 is a partial sectional view of the headrest through the inclined first plane of FIG. 10 wherein the normal infant cranium is rotated thirty degrees clockwise about its longitudinal axis to contact a lateral support surface thereof.
[0050] FIG. 13 is a partial sectional view of the orthosis through the first plane of FIG. 10 of a scaphocephalic cranium.
[0051] FIG. 14 is a partial sectional view of the headrest through the first plane of
[0052] FIG. 10 wherein the scaphocephalic cranium is rotated thirty degrees clockwise about its longitudinal axis to contact a lateral support surface thereof.
[0053] FIG. 15 is a partial sectional view of the orthosis through the inclined first plane. of FIG. 10 of a plagiocephalic cranium.
[0054] FIG. 16 is a partial sectional view of the headrest through the inclined first plane of FIG. 10 wherein the plagiocephalic cranium is rotated thirty degrees clockwise about its longitudinal axis to contact a lateral support surface thereof.
[0055] FIG. 17 is a partial sectional view of the headrest through the inclined first plane of FIG. 10 in use with a brachycephalic cranium.
[0056] FIG. 18 is a partial sectional view of the headrest through the inclined first plane of FIG. 10 wherein the brachycephalic cranium is rotated forty-five degrees clockwise about its longitudinal axis to contact a lateral support surface thereof.
[0057] FIG. 19 is perspective view of an alternative embodiment of the present invention.
[0058] FIG. 20 is a frontal view of the craniocervical orthosis shown in FIG. 22 .
[0059] FIG. 21 is a sectional view along Line 21 - 21 of FIG. 19 .
[0060] FIG. 22 is a perspective view of another alternative embodiment of the present invention.
[0061] FIG. 23 is a sectional view along Line 23 - 23 of FIG. 22 .
[0062] FIG. 24 is yet another embodiment of the present invention.
[0063] FIG. 25 is a sectional view along Line 25 - 25 of FIG. 24 .
[0064] FIGS. 26 is a front perspective view of yet another alternative embodiment of the present invention that comprises two spacing members positioned on the rim.
[0065] FIG. 27 is a side sectional elevation through Line 27 - 27 of FIG. 26 .
[0066] FIG. 28 is a sectional elevation through Line 28 - 28 of FIG. 26 .
[0067] FIG. 29 is a front perspective view of still another embodiment of the present invention wherein the lateral support surfaces are laterally adjustable.
[0068] FIG. 30 is a rear section view through plane 30 - 30 of FIG. 29 .
DETAILED DESCRIPTION OF THE INVENTION
[0069] When referencing the figures, standard anatomical terms of location are used. For example, a sagittal plane is a plane parallel to the sagittal suture 5 and divides the body into sinister and dexter portions. A coronal plane divides the body into posterior and anterior portions. A transverse plane divides the body into superior and inferior portions.
[0070] FIG. 1 through FIG. 4 show a headrest 10 that is the preferred embodiment of the present invention. The headrest 10 comprises a bottom surface 12 for contacting a resting surface 14 , and a top surface 16 for contacting an infant's cranium. The top surface 16 comprises a generally hemi-ellipsoidal depression 18 , a contact surface 19 that corresponds to the shape of a normal infantile cranium, and a rim 22 defining a substantial portion of the depression 18 . At one end of the depression 18 , a ridge 20 is positioned to support the neck of the infant. The top surface 16 is preferably made of a closed cell foam material, but may alternatively be made of open cell foam material covered with a vinyl or other surface coating, closed cell foam layered over higher density foam, open cell foam layered over higher density foam, or closed cell foam layered over a more rigid solid or hollow plastic.
[0071] A front surface 24 , preferably curved, is positioned to cradle the infant's shoulders and support the neck of the infant while the infant's cranium is in contact with the top surface 16 . A preferably-curved side surface 26 extends between the rim 22 and the bottom surface 12 . In this preferred embodiment, the headrest 10 is a continuous, uniform, solid body. However, it is anticipated that variations of the uniformity or continuity of the body could occur and be utilized.
[0072] In normal operation for correction of an abnormally shaped infant cranium, the headrest 10 is placed on the resting surface 14 so that the bottom surface 12 is in contact therewith. The infant's head is then placed in the depression 18 with the infant's cranium resting on the contact surface 19 . Initially, the posterior and part of the side aspects of the infant's head contact the contact surface 19 , although during the sleep period the infant's head may roll to one side or the other. Throughout the sleep period, the infant's neck is supported by the ridge 20 .
[0073] The infant's shoulders are aligned in and cradled by the curved front surface 24 . As the infant's head makes contact with the top surface 16 , the contact surface 19 provides external forces acting on any abnormal bulges of the infant's cranium and reduces or eliminates external forces that act on abnormal depressions (flattened areas) of the infant's cranium. This contact reduces the net outward forces from brain and skull growth at these prominences, and redirects the growth to areas of the cranium where the infant's head is not in contact with the top surface 16 .
[0074] It should be noted that that amount of contact of the infant's cranium with the contact surface 19 varies according to the size of the infant's cranium. For example, a newborn infant's cranium will contact relatively little of the contact surface 19 and, in a non-rotated position, the contact will occur primarily at the occipital bone and adjacent areas of the left and right parietal bones. As the infant grows over time, the size of the cranium approaches the size of the depression 18 , with an increasingly greater area of contact.
[0075] The headrest 10 works similarly to prevent cranial deformities. The infant's head is placed in the depression 18 , the contact surface 19 of which matches the round, normally-shaped contour of the posterior and side aspects of the head, resulting in the head “growing into” the properly-shaped contact surface 19 over time. As the cranium grows, any existing deformities will conform to the normal shape of the contact surface 19 of the depression 18 . Because of its semi-rigid character, the contact surface 19 allows the infant's cranium to grow evenly and maintain its normal shape. Typically, this occurs as the headrest is used from two to seven months of age, although, due to statistical variations in head circumference of infants, this is more appropriately a function of the cranial circumference (i.e., until the head grows to the same size as the depression 18 ).
[0076] FIG. 7A and FIG. 7B are a rear elevational view and a top elevational view, respectively, of a normally-shaped infant cranium 400 having a circumference of less than 46.5 cm and a left parietal bone 402 connected to a right parietal bone 404 with the sagittal suture 406 . The left and right parietal bones 402 , 404 are connected to the frontal bone 412 via the coronal suture 414 and to the occipital bone 416 with the lamboidal suture 418 . The sagittal suture 406 joins the coronal suture 414 at the anterior fontanelle 420 . The lamboidal suture 418 joins the sagittal suture 406 at the posterior fontanelle 422 . When positioned in the preferred embodiment of the headrest 10 , a cranial surface area 424 that includes a portion of the occipital bone 416 , and the posterior portions of the left and right parietal bones 402 , 404 makes contact with the contact surface 19 of the depression 18 , as described supra.
[0077] FIG. 8A shows head circumference-for-age of males from birth to thirty-six months. FIG. 8B shows head circumference-for age for females from birth to thirty six months. As can be seen from these figures, less than five-percent of all infants have a head circumference of less than 36.5 cm at two months of age. At seven months, at least ninety-five percent of all infants have a head circumference less than 46.5 cm. Thus, a preferred embodiment of an orthosis having the features of the present invention is configured to address, at a minimum, head circumferences within a range of 36.5 cm to 46.5 cm in circumference. However, it is anticipated that this will accommodate head circumferences within a range from thirty-two (32) to forty-eight (48) centimeters and still provide the benefits described herein.
[0078] FIGS. 9A and 9B depict side elevation views of two infants having normally-shaped craniums of differing circumferences positioned in the same preferred embodiment of the cranial orthosis 10 , and show the position of predetermined coronal planes relative to the orthosis 10 . Head circumference for an infant is the largest distance around the head, and generally is found in a plane 47 that intersects the forehead of the infant and the most posterior point 54 of the cranium.
[0079] More specifically, FIG. 9A depicts a first infant's cranium 49 that has a circumference of 46.5 cm, and has an anterior-posterior distance APD 1 , which is the distance between the most posterior point 54 on the infant's head and the most anterior point 57 on the infant's forehead. A first coronal plane 51 is defined as a coronal (i.e., horizontal) plane positioned approximately at forty percent (40%) of the anterior-posterior distance APD 1 , a position which approximates the height of the earhole 52 for an infant having this head size. With respect to the orthosis 10 , the first coronal plane 51 is positioned approximately 4.8 to 5.3 cm above the nadir 23 (i.e., lowest point) of the depression 18 . A third coronal plane 21 is defined as a coronal plane positioned at the most anterior contact point 27 between the infant's cranium 49 and the headrest 10 . With respect to the headrest 10 , the third coronal plane 21 is positioned approximately 8.0 to 8.6 cm from the bottom surface. Similarly, FIG. 9B depicts a second infant cranium 55 of 36.5 cm in circumference. A second coronal plane 56 is defined as a coronal plane positioned at approximately seventy percent (70%) of APD 2 for an infant having this head size. With respect to the orthosis 10 , the second coronal plane is positioned approximately 8.0 to 9.0 cm above the nadir 23 of the depression.
[0080] As shown in FIG. 3 , in the preferred embodiment, the contact surface 19 is defined as the surface area of the depression 18 that is (1) superior to an inclined first plane 47 angled between 10 and 20 degrees from vertical in the superior direction and intersecting the nadir 23 , and (2) posterior of the third coronal plane 21 . At a minimum, however, the contact surface 19 is at least the surface area of the depression 18 that is (1) superior to a diagonal plane angled 45-degrees from vertical in the superior direction and intersecting the nadir 23 , and (2) posterior of the third coronal plane 21 .
[0081] FIG. 5 and FIG. 6 depict preferred dimensions of a specific embodiment of the orthosis 10 . As shown, the length of the orthosis 10 from its most inferior to its most superior point is 23.3 cm. The height of the ridge 20 above the bottom surface 12 where it intersects the longitudinal axis is 2.9 cm. At its highest point, the rim 22 is 9.4 cm from the bottom surface 12 . The ridge 20 is 6.5 cm from the mid-cranial transverse plane 70 , which is the transverse plane intersecting the nadir 23 of the depression 18 . The mid-cranial transverse plane is 7.5 cm from the most superior contact point 27 . In the preferred embodiment, that superior point 27 is 8.3 cm from the bottom surface 12 .
[0082] In the preferred embodiment, as shown in FIG. 6 , in which the shading has been removed for clarity, the width of the curved front surface 24 is 23.3 cm and the width of the ridge 20 is 13.3 cm. The depression has a front portion 37 extending 2.3 cm from the ridge 20 along the horizontal, longitudinal axis 31 , and is bounded on either side with symmetrical protrusions 33 . A middle portion 25 is immediately adjacent the front portion 37 wherein the interior boundary 29 of the rim 22 adjacent the middle portion 25 is substantially straight. An arced rear portion 35 is adjacent the middle portion 25 , wherein the interior boundary 29 of the rim is symmetrically curved to connect one sides of the middle portion 25 to the other. The maximum depth of the arced rear portion 35 from the middle portion 25 to the interior boundary 29 of the rim 22 along the horizontal longitudinal axis 31 is 3.9 cm. The greatest width of the middle portion 25 is at the boundary with the front portion 37 (line B) at 16.3 cm. The middle portion 25 is narrowest immediately adjacent the arced rear portion 35 (line A) at 12.7 cm. The depth of the middle portion 25 —i.e., the distance between the front portion 37 and arced rear portion 35 —is approximately 8.0 cm. The superior- to inferior widening of the middle portion 25 provides space for the ears of an infant who is resting in the headrest 10 in a supine position, which is important to avoid misshaping of the ear. The depth of the depression 18 from the crest of the ridge 20 to the interior boundary of the rim 22 along the horizontal longitudinal axis is 14.2 cm. The thickness C of the rim 22 around the arced portion 35 is approximately 2 cm. Although the dimensions of the preferred embodiment are given with specific measurements, it is understood that the measurements could vary slightly without altering the effectiveness of the device. In that regard, the dimensions provided are understood to be substantial approximations of the preferred embodiment of the device.
[0083] Returning now to a description of the present invention, FIGS. 10 and 11 depict the preferred embodiment of the present invention in which an infant 60 having a normally-shaped cranium 62 of approximately forty (40) centimeters in circumference is supinely positioned on the headrest 10 . The first coronal plane 51 —as defined above with respect to the predetermined circumference of 46.5 cm—extends longitudinally, and is parallel to the second coronal plane 56 . The mid-cranial transverse plane 70 is orientated perpendicular to the first coronal plane 51 and extends through the nadir 23 , in which the most posterior point 54 of the cranium 62 rests. An inclined first plane 74 , which is representative of a typical plane in which the head circumference is measured, is positioned superior and inclined relative to the mid-cranial transverse plane 70 , and intersects the nadir 23 , and the most anterior point on the forehead.
[0084] As noted with respect to FIG. 1 through FIG. 4 , the headrest 10 (or orthosis) comprises the bottom surface 12 that contacts the resting surface 14 during use and a contact surface 92 that contacts the infant's cranium 62 . The generally hemi-ellipsoidal depression 18 is formed in the top surface 16 with at least a contact surface 19 (see FIG. 3 ) having a shape of a portion of a normal infant cranium 62 . In the preferred embodiment, and as noted with respect to FIG. 3 supra, the contact surface 19 has a surface area generally corresponding to the posterior aspects of the left and right parietal bones in addition to a substantial portion of the occipital area, as discussed with reference to FIG. 5 . The top surface 16 is semi-rigid and relatively non-flexible, maintains its overall shape under stress, and demonstrates minimal superficial focal elasticity at the site of cutaneous contact. The ridge 20 at an end of the depression 18 supports, and is contoured to the shape of, the infant's neck 86 .
[0085] At least the contact surface 19 of the preferred embodiment has a hardness of between sixty-five and seventy-five when measured with a OO-scale durometer, which is the preferred hardness required for the both prevention and correction of positional deformities as described herein. However, because the headrest 10 is preferably of uniform consistency, it is anticipated that the entire outer surface of the headrest 10 will have the same hardness. It should be noted that prevention only, as opposed to both prevention and correction, can be accomplished with a hardness of between twenty-five and thirty-five on the same scale.
[0086] Still referring to FIG. 10 and FIG. 11 , the contact surface 19 further comprises at least a portion of first and second lateral support surfaces 88 , 92 . A portion 90 of the first and second lateral support surfaces 88 , 92 is positioned anterior of the first coronal plane 51 and superior to the mid-cranial transverse plane 70 . In order to prevent obstructive amblyopia, the first and second lateral support surfaces 88 , 92 do not extend anteriorly of the second coronal plane 56 , as providing a completely unobstructed visual field is imperative to eliminate the risk of iatrogenic-induced neuro-opthalmological injury (i.e., obstructive amblyopia).
[0087] FIG. 11 is a partial sectional view of the normal infant cranium 62 in the inclined first plane 74 of FIG. 10 . In the preferred embodiment, the first and second lateral support surfaces 88 , 92 are substantially vertical at their upper end with slight curvature anterior of the first coronal plane 51 . When the infant's cranium 62 is in the supine position, contacting forces 96 are applied proximal to the occipital bone 98 at the posterior aspect of the cranium 62 with only minimal application at the most posterior end of the parietal bones 100 , 102 . As growth occurs, the left and right parietal bones 100 , 102 expand laterally and eventually contact substantially the entire contact surface 19 when the infant's cranium 62 grows to a circumferences of 46.5 cm as shown in FIG. 9A . In this manner the shape of the parietal and occipital regions on the infant's cranium 62 conforms over time (i.e., months) to the shape of the contact surface 19 .
[0088] FIG. 12 depicts the normal infant cranium 62 shown in FIG. 11 rotated thirty degrees clockwise about the longitudinal axis 94 . Such rotation causes a corresponding shift in the area of contact of the cranium 62 with the contact surface 19 , and thus where external forces 96 are applied to the cranium 62 . The contact forces 96 still contact the occipital bone 98 and a greater portion of the posterior right parietal bone 102 . In addition, the second lateral support surface 92 contacts the cranium 62 at the frontal bone 104 anterior of the coronal suture 106 .
[0089] As overall growth of the cranium 62 occurs, less rotation of the cranium 62 is allowed, which results in further maintenance of the normal head shape. Additional expansion and overall growth causes eventual de-rotation of the cranium 62 back to twenty degrees of rotation or less with the contact surface 19 and first and second lateral support surfaces 88 , 92 limiting lateral expansion of the parietal bones 100 , 102 . In other words, as the infant continues to grow and the circumference of the cranium 62 approaches the size of the depression 18 , the head is progressively limited to less rotation, resulting in the head “growing into” the properly-shaped contact surface 19 . For example, if the size of the cranium 62 is identical to the size of the depression 18 , rotation of the cranium 62 will be entirely prohibited. Thus, as the cranium 62 grows, any existing deformities will conform to the normal shape of the contact surface 19 of the depression 18 .
[0090] FIG. 13 depicts a partial sectional view of the inclined first plane 74 in FIG. 10 wherein a scaphocephalic cranium 134 of an infant is supinely positioned in the depression 18 in the top surface 16 of the orthosis 10 . In this supine position, the contact surface 19 of the depression 18 causes forces 146 to act on the scaphocephalic cranium 134 at the occipital bone 144 . If this non-rotated, supine position can be maintained, the absence of forces acting on the parietal bones 147 , 149 will allow the parietal bones 147 , 149 to grow laterally into a normally-shaped cranium.
[0091] FIG. 14 depicts the scaphocephalic cranium 134 shown in FIG. 11 rotated thirty degrees clockwise about its longitudinal axis 148 . In this rotated position, the second lateral support surface 92 contacts the frontal bone 150 and thereby prevents contact between the mid- or upper-right parietal bone 149 with the contact surface 19 of the depression 18 , and allowing for only minimal contact with the right parietal bone 149 at its most posterior point. Once again, the contact surface 19 of the depression 18 contacts and provides forces acting on the occipital bone 144 . The absence of contact and forces 146 acting on the left parietal bone 147 and almost all of the right parietal bone 149 allows for parietal expansion and progression toward a normal head shape. Rotation in the counter-clockwise direction results in similar contact of the cranium 134 with the orthosis 10 on the opposite side of the cranium 134 .
[0092] FIG. 15 is a partial sectional view of the preferred embodiment through the first plane 74 of FIG. 8 with an infant having a plagiocephalic cranium 170 with abnormal prominent growth at the left parietal bone 196 and the right side of the frontal bone 198 , in addition to a flattened configuration at the right parietal bone 202 and the occipital bone 200 . In the supine position shown, initial forces 194 are concentrated on the lower end of the left parietal bone 196 and left occipital bone 200 . However, it should be noted that this is an unstable configuration that will inevitably lead to rotation—in this case, clockwise rotation—about the longitudinal axis 192 .
[0093] FIG. 16 is a partial sectional view within the inclined first plane 74 of FIG. 10 depicting the infant having a plagiocephalic cranium 170 rotated thirty degrees clockwise about its longitudinal axis 192 . In this rotated position, the contact surface 19 contacts and provides forces 194 acting on the prominent left parietal bone 196 , thereby restricting further lateral growth of that prominent bone. Additionally, the second lateral support surface 92 contacts and provides forces 199 acting on the right side of the frontal bone 198 and also restricting growth in that prominent area. The contact with the second lateral support surface 92 further eliminates all external forces from the flattened occipital bone 200 and right parietal bone 202 , thus redirecting growth to these bones by allowing the bones to expand. In this manner, the infant's plagiocephalic cranium 170 is allowed to grow into a normal shape.
[0094] FIG. 17 depicts the preferred embodiment in use with a brachycephalic cranium 204 having a flattened occipital bone 216 and bulging, prominent left and right parietal bones 208 , 210 resting in a supine position. The contact surface 19 contacts and provides forces 206 acting on both parietal bones 208 , 210 restricting lateral growth of these parietal prominences. The normal cranial shape of the contact surface 19 eliminates any contact and forces acting on the occipital bone 216 . This redirects growth and expansion in a more frontal direction as well as allows the flattened occipital bone 216 to grow outward, thereby allowing for correction of the deformity over time with growth.
[0095] FIG. 18 shows the same brachycephalic cranium 204 depicted in FIG. 17 resting in the preferred embodiment of the orthosis 10 and rotated forty degrees about the longitudinal axis of the headrest 10 . The contact surface 19 of the depression 18 contacts and provides forces acting on the prominent right parietal bone 210 and thereby restricts growth of that bone. At the same time, the first lateral support surface 88 contacts and provides forces 206 acting on the prominent left parietal bone 208 and, once again, restricts growth of that bone 208 . The normal cranial shape of the contact surface 19 provides a gap between the contact surface 19 of the depression 18 and the flattened occipital bone 216 , thereby eliminating forces acting on the occipital bone 216 and, once again, allows for outward growth in that area. The lack of contact forces acting on the frontal bone 211 also allows for forward growth to the cranium 204 . In this manner, the orthosis 10 provides for correction of a brachycephalic cranium 204 resting in a rotated position.
[0096] Although the invention has thus far been described with reference to only full term infants, the principles and concepts are also applicable to a premature infant's cranium, albeit on a smaller scale. In fact, the cranial vault of a premature infant is more susceptible to development of positional deformities than a full term infant because the cranial bones are much weaker and more malleable, and the skin more fragile.
[0097] According to industry data, the mean head circumference of an infant at 26 weeks is about 23.5 centimeters, the mean head circumference of an infant at 36 weeks is roughly 33 cm, and two standard deviations on either side of this 26- to 36-week growth curves is slightly larger than ±2 cm. Thus, by simply “shrinking” the preferred embodiment described herein to accommodate this curve, the same principles are operative to correct and prevent positional deformities in premature infants in the same manner. Because of the weaker and more malleable cranial bones of a premature infant, the top surface should be softer than the top surface as described with reference to the preferred embodiment herein. The inventor has found that the hardness of the surface when used for premature infants is between 20-30 on the OO scale durometer.
[0098] FIG. 19 through FIG. 21 show an alternative embodiment of the present invention that requires less material to manufacture. The headrest 300 comprises two beams 302 for contacting a resting surface 304 , and a top surface 306 for contacting an infant's cranium. The elongated beams 302 are positioned along opposite sides of the headrest 300 . The front and back of the headrest 300 are open, forming an opening 308 defined on either side by the beams 302 .
[0099] The top surface 306 of the headrest 300 comprises a generally hemi-ellipsoidal depression 310 having the top surface 306 that corresponds to the shape of a normal infantile cranium and a rim 312 that defines a substantial portion of the depression 310 . At one end of the depression 310 , a ridge 314 is positioned to support the neck of the infant. The top surface 306 is preferably made of a closed cell foam material, although other materials may be used as described hereinabove. A pair of side surfaces 316 , only one of which is shown by FIG. 5 , adjoin the rim 312 to the beams 302 .
[0100] As shown more clearly by FIG. 21 , the beams 302 are positioned at opposing sides of the headrest 300 and along the perimeter thereof, thereby forming the opening 308 between the beams 302 . In another embodiment, however, the opposed beams 302 can be positioned at the front and rear of the headrest 300 .
[0101] After placement of the headrest 300 on the resting surface 304 so that the beams 302 are in contact therewith, the infant's head is placed in the depression 310 with the infant's head resting in the depression 310 . Correction and/or prevention of the infant's abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment.
[0102] FIG. 22 and FIG. 23 , which is a sectional view along Line 23 - 23 of FIG. 22 , show another embodiment of the present invention. The apparatus of this embodiment comprises a mattress or padded surface 340 and a generally hemi-ellipsoidal depression 342 in a portion of the mattress surface 340 . A top surface 344 in the depression 342 corresponds to the shape of a normal infantile cranium. In this embodiment, the top surface 344 of the depression 342 is semi-rigid, resilient, and made of a closed cell foam material, providing external forces acting on abnormal cranial bulges and minimizing or eliminating external forces acting on abnormal cranial depressions of the infant. However, it is anticipated that other materials could be utilized, such as open cell foam with a vinyl coating. In this embodiment, a ridge 346 at one end of the top surface 344 is shaped and positioned to support the neck of the infant while the infant's head rests on the top surface 344 of the apparatus. In another version of this embodiment, it is anticipated that the ridge 346 will be eliminated.
[0103] The embodiment shown by FIG. 22 and FIG. 23 is disclosed with a substantially flat mattress or padded surface 340 . However, it is anticipated that the mattress or padded surface 32 could be contoured to prevent an infant from rolling. It is further anticipated that the area of the mattress or padded surface 340 surround the depression 342 could be raised to provide support for the infant's head in a slightly raised position.
[0104] As with the already-described embodiments, the infant's head is placed in the depression 342 formed in the mattress 340 such that the infant's head is in contact with the top surface 344 . The infant's neck is supported by the ridge 346 , while the infant's body is supported in a comfortable resting position by the mattress 340 in a generally supine position. Correction and/or prevention of the infant's abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment.
[0105] FIG. 24 and FIG. 25 , which is a sectional view along Line 25 - 25 of FIG. 24 , show another embodiment of the present invention, an apparatus comprised of a semi-rigid body 360 with a hemi-ellipsoidal depression 362 having a contact surface 364 that is in the shape of a normal infantile cranium. A plurality of legs 366 support the semi-rigid body 360 in a position to allow an infant's head to rest on the contact surface 364 . In this embodiment, there are four legs 366 , as shown in FIG. 24 and FIG. 25 . However, it is anticipated that more or fewer legs could be used to support the body 360 . The contact surface 364 is resilient and made of closed cell foam, although in alternative embodiments of the present invention the contact surface 364 may be made of other material, including open cell foam covered with a vinyl coating and other materials as described hereinabove. Furthermore, a ridge 368 at one end of the contact surface 364 is shaped and positioned to support the neck of the infant while the infant's head rests on the contact surface 364 of the apparatus.
[0106] After placement of the apparatus on a resting surface so that legs 366 are in contact therewith, the infant's head is placed in the depression 362 with the infant's head resting on the contact surface 364 and the infant's neck being supported by the ridge 368 . Correction and/or prevention of the infant's abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment.
[0107] It should be noted that the smaller the infant cranium, the more angular rotation of the cranium about the longitudinal axis is required to contact one of the lateral support surfaces. In other words, generally speaking, a smaller infant cranium placed in a given headrest and depression will require more rotation about the longitudinal axis than a larger, similarly-shaped cranium positioned in the same headrest and depression. However, it is desirable that rotation of an infant's cranium located within a depression be limited to approximately the range of angular rotation described with reference to the foregoing figures. Although this concern could be addressed by manufacturing the headrest in various sizes to correspond to the range of expected cranial sizes as set forth supra, for commercialization, it is desirable for cost reduction purposes that fewer variations of the present invention be produced to take advantage of manufacturing economies of scale.
[0108] This conflict between manufacturing preference and patient treatment preference can be addressed, however, by providing for adjustability of the positions of the lateral support surfaces, thus allowing rotation of the cranium to be limited as desired based on the size of the cranium. For example, FIG. 26 through FIG. 28 show another embodiment of a headrest 510 having the features of the present invention wherein the position of the lateral support surfaces is adjustable to accommodate various cranium sizes (i.e., limit the range of possible rotation of the cranium within the depression). FIG. 26 is a front perspective view of the embodiment. FIG. 27 and FIG. 28 are sectional views through ine 27 - 27 and Line 28 - 28 , respectively, of FIG. 26 .
[0109] As referenced with respect to the previously-described embodiments, the headrest 510 of this alternative embodiment comprises a bottom surface 512 , and a top surface 516 for contacting an infant's cranium. The top surface 516 comprises a generally hemi-ellipsoidal depression 518 , a contact surface 519 that corresponds to the shape of a normal infantile cranium, and a rim 522 defining a substantial portion of the depression 518 . A ridge 520 is positioned at one end of the depression 518 to support the neck of the infant. The top surface 516 is preferably made of a closed cell foam material, but may alternatively be made of open cell foam material covered with a vinyl or other surface coating, closed cell foam layered over higher density foam, open cell foam layered over higher density foam, or closed cell foam layered over a more rigid solid or hollow plastic. A curved front surface 524 is positioned to cradle the infant's shoulders and support the neck of the infant while the infant's cranium is in contact with the top surface 516 . A preferably-curved side surface 526 extends between the rim 522 and the bottom surface 512 .
[0110] Two attachable spacing members 550 are positioned over the rim 522 and preferably centered at preferably approximately sixty degrees from the longitudinal axis 531 . Preferably, the spacing members 550 are substantially U-shaped and sized to fit snugly over the rim 522 , and each has a first leg 551 which extends into the depression 518 and contacts the lateral support surfaces 588 , 592 , and a second leg 552 extending downward adjacent to and contacting the sidewall 526 of the headrest 510 . The spacing members 550 are made of a closed cell foam material, but may alternatively be made of open cell foam material covered with a vinyl or other surface coating, closed cell foam layered over higher density foam, open cell foam layered over higher density foam, or closed cell foam layered over a more rigid solid or hollow plastic.
[0111] As shown in FIG. 28 , in this specifically-described embodiment, the outer portion 552 of the spacing member 550 is removeably attached to the body of the headrest 510 with a hook-and-loop fastener 554 . Alternative embodiments contemplate other fastening hardware and adhesives. Placement of the spacing members 550 on the rim 522 provides the ability to alter the rotation range of the infant's head when placed in the headrest 510 .
[0112] Normal operation for correction of an abnormally shaped infant cranium is as referenced with respect to the previously-described embodiments. The headrest 510 is placed on a resting surface (not shown) so that the bottom surface 512 is in contact therewith. The infant's head is then placed in the depression 518 with the infant's cranium resting on the contact surface 519 . The effective distance between the lateral support surfaces 588 , 592 can be altered by attaching one or more of the spacing members 550 for proper fitting of the infant's cranium within the headrest 510 . In this specific embodiment, it is preferred that the maximum thickness T 1 of the leg 551 of the spacing members 550 extending into the depression 518 and along a sagittal axis is approximately eight millimeters.
[0113] Initially, the posterior and part of the side aspects of the infant's head contact the contact surface 519 , although during the sleep period the infant's head may roll to one side or the other. When this occurs, the side of the infant's head will contact the interior surface 553 of the first leg 551 of one of the spacing members 550 . In this manner, the interior surface 553 acts as an adjusted lateral support surface. Throughout the sleep period, the infant's neck is supported by the ridge 520 . The infant's shoulders are aligned in and cradled by the curved front surface 524 . As the infant's head makes contact with the top surface 516 , the contact surface 519 provides external forces acting on any abnormal bulges of the infant's cranium and reduces or eliminates external forces that act on abnormal depressions (flattened areas) of the infant's cranium. As referenced with respect to the previously described embodiments, this contact reduces the net outward forces from brain and skull growth at these prominences, and redirects the growth to areas of the cranium where the infant's head is not in contact with the top surface 516 . As the infant's cranium grows, the spacing members 550 can be removed or replaced with spacing members having a thinner first leg 551 .
[0114] Although in this embodiment the spacing members 550 are described as being substantially U-shaped, it is anticipated that the spacing members 550 could have varying shapes and attachment locations on the headrest 510 . For example, the spacing members 550 could be a circular or rectangular pad having a flat interior surface to act as an adjusted lateral support surface and a flat exterior surface for adhesion to the lateral support surfaces of the headrest.
[0115] FIG. 29 and FIG. 30 show an alternative embodiment of a “low profile” headrest 610 with first and second laterally adjustable siderails 626 . FIG. 29 is a perspective view of the embodiment, while FIG. 30 is a rear section view through plane 30 - 30 of FIG. 29 . The “low profile” headrest 610 , as described supra, is provided that otherwise has some of the features of the present invention, such as the top surface 616 , depression 618 , and the like. However, as discussed supra, this “low profile” headrest 610 does not itself provide lateral support with lateral support surfaces.
[0116] As shown in FIG. 29 and FIG. 30 , the laterally-adjustable siderails 626 are fixable to the top surface 616 of the “low profile” headrest 610 with hook-and-loop 630 or other fastening methodology and positioned to provide lateral support to an infant's cranium resting in the headrest 610 with lateral support surfaces 688 , 692 on the interior sidewalls of the siderails 626 . The laterally adjustable siderails 626 are positioned such that the lateral support surfaces 688 , 692 are positioned anterior of the first coronal plane and superior to the mid-cranial transverse plane, as described with reference to the other embodiments. The first and second lateral support surfaces 688 , 692 do not extend anteriorly of the second coronal plane, as providing a completely unobstructed visual field is imperative to eliminate the risk of iatrogenic-induced neuro-opthalmological injury (i.e., obstructive amblyopia). In addition, the laterally-adjustable siderails 626 allow for adjustment of the distance between the lateral support surfaces 688 , 692 by repositioning both laterally-adjustable siderails 626 toward the infantile cranium and reattaching them to the top surface 616 .
[0117] The present invention is described above in terms of a preferred illustrative embodiment of a specifically described headrest, as well as alternative embodiments of the present invention. Those skilled in the art will recognize that alternative constructions of such a headrest can be used in carrying out the present invention. Other aspects, features, and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims. | A device and method for preventing and correcting abnormal shaping of an infant's cranium by applying external forces over time with the growth of an infant to achieve normal shaping of the infant's head. The device is a cranial orthosis having a depression with a contact surface in the shape of at least a portion of a normal infantile cranium. The orthosis further provides lateral support surfaces creating points of contact to restrict rotation of the infant's cranium and provide additional external forces for normal shaping of the infant's cranium. Because the present invention is non-conforming to the shape of an abnormal skull, the exerted forces cause accelerated expansion of the skull in less prominent areas coincident with brain and skull growth. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
Polyurethanes are useful in a variety of applications. For example, polyurethane elastomers are used in automotive parts, shoe soles, and other products in which toughness, flexibility, strength, abrasion resistance, and shock-absorbing properties are required. Polyurethanes are also used in coatings and in flexible and rigid foams.
Polyurethanes, in general, are produced by the reaction of a polyisocyanate and a polyol in the presence of a catalyst. The catalyst is typically a low molecular weight tertiary amine such as triethylenediamine.
Polyurethane foams are produced through the reaction of a polyisocyanate with a polyol in the presence of various additives. One class of additives which is particularly effective as blowing agents is the chlorofluorocarbons (CFCs). CFCs vaporize as a result of the reaction exotherm during polymerization and cause the polymerizing mass to form a foam. However, the discovery that CFCs deplete ozone in the stratosphere has resulted in mandates for restricting CFC use. Therefore, more efforts have gone into the development of alternatives to CFCs for forming urethane foams and water blowing has emerged as an important alternative. In this method, blowing occurs from carbon dioxide generated by the reaction of water with the polyisocyanate. Foams can be formed by a one-shot method or by formation of a prepolymer and subsequent reaction of the prepolymer with water in the presence of a catalyst to form the foam. Regardless of the method, a balance is needed between reaction of the isocyanate and the polyol (gelling) and the reaction of the isocyanate with water (blowing) in order to produce a polyurethane foam in which the cells are relatively uniform and the foam has specific properties depending on the anticipated application; for example, rigid foams, semi-rigid foams, and flexible foams.
The ability of the catalyst to selectively promote either blowing or gelling is an important consideration in selecting a catalyst for the production of a polyurethane foam with specific properties. If a catalyst promotes the blowing reaction to too high a degree, carbon dioxide will be evolved before sufficient reaction of isocyanate with polyol has occurred. The carbon dioxide will bubble out of the formulation, resulting in collapse of the foam and production of a poor quality foam. At the opposite extreme, if a catalyst promotes the gelling reaction too strongly, a substantial portion of the carbon dioxide will be evolved after a significant degree of polymerization has occurred. Again, a poor quality foam is produced; characterized by high density, broken or poorly defined cells, or other undesirable features. Frequently, a gelling catalyst and a blowing catalyst are used together to achieve the desired balance of gelling and blowing in the foam.
Tertiary amine catalysts have been used to in the production of polyurethanes. The tertiary amine catalysts accelerate both blowing (reaction of water with isocyanate to generate carbon dioxide) and gelling (reaction of polyol with isocyanate) and have been shown to be effective in balancing the blowing and gelling reactions to produce a desirable product. However, typical tertiary amines used as catalysts for polyurethane production generally have offensive odors and many are highly volatile due to low molecular weight. Release of tertiary amines during polyurethane production may present significant safety and toxicity problems, and release of residual amines from consumer products is generally undesirable.
Amine catalysts which contain amide functionality have an increase in molecular weight and hydrogen bonding and reduced volatility and odor when compared to related compounds lacking amide functionality. An advantage of the use of compounds having amide functionality in the preparation of polyurethanes is that the amide chemically bonds with the urethane during the polymerization reaction and thus is not released from the finished product. However catalyst structures which contain both amine and amide functionality typically have low to moderate activity and promote both the blowing and gelling reaction to varying extents.
Examples of patents directed to compounds having both tertiary amine and amide functionality are described below:
U.S. Pat. No. 3,073,787 (Krakler, 1963) discloses an improved process for preparing isocyanate foams in which catalysts made from 3-dialkylaminopropionamide and 2-dialkylaminoacetamide are used.
U.S. Pat. No. 4,049,591 (McEntire et al., 1977) discloses a group of 1,3-substituted bis-(N,N,-dimethylaminopropyl)amines as catalysts in reacting polyisocyanate with polyols. The substituted group can be cyano, amide, ester, or ketone.
U.S. Pat. No. 4,248,930 (Haas et al., 1981) discloses several tertiary amines catalysts for the production of polyurethane resins. In the example, a mixture of bis(dimethylamino-n-propyl)amine and N-methyl-N'-(3-formylaminopropyl)piperazine is used to form a PVC/polyurethane-foam laminate.
U.S. Pat. No. 4,548,902 (Hasler et al., 1985) discloses combining a polybasic amino compound, such as 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide, with a direct or reactive dyestuff for use in cellulose dyeing applications.
WO 94/01406 (Beller, et al., 1994) discloses a group of chelating agents, such as 3-[3-(N',N'-dimethylaminopropyl)-N-methyl]propionamide, and 3-[3-(dimethylamino)-propyl]propionamide, suitable for producing paramagnetic complexes which can be used as contrast agents in magnetic resonance diagnosis applications.
EP 799,821 (Gerkin, et al., 1997) discloses amine/amide catalysts, such as the following two compounds, ##STR2## for formation of polyurethanes. The catalysts are reported to have low fugitivity due to their reactivity with isocyanates.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to the use of the following two compounds as catalysts in the production of polyurethanes: 3-[3-(dimethylamino)propyl]-propionamide (formula I below) and 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide (Formula II below). ##STR3##
The compounds represented by I and II are effective catalysts in the production of polyurethanes in which an organic polyisocyanate reacts with a compound containing a reactive hydrogen, such as, an alcohol, a polyol, an amine or water. They are particularly useful for the gelling reaction in which an organic polyisocyanate reacts with a polyol. Among the advantages provided by the compounds in the production of polyurethanes are:
they are very active catalysts;
they are selective to the gelling reaction, i.e., the reaction between an organic polyisocyanate and a polyol; and
they bind to the urethane, resulting in little or none of the compound being released from the finished product.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of this invention are readily prepared by the Michael addition of an amino functional amine to an acrylamide. The amino functional amine and acrylamide are present in the reaction mixture in molar ratio of from about 1:10 to about 20:1, and preferably at a ratio of 1 to 2 moles amino amine per equivalent of acrylamide. Air is used to saturate the reaction mixture in order to inhibit the free radical polymerization of acrylamide.
The reaction is preferably carried out at atmospheric pressure; however other pressures can be used.
The reaction can be carried out at a temperature ranging from 0 to 130° C.; preferably from 30 to 100° C., and is allowed to run for 0.1 to 100 hours, preferably, 2 to 12 hours.
In principle, the reagent monomer can be reacted in batch fashion, via staged addition, or continuously. Synthesis is advantageously performed in a mixture of the neat monomers, however, an inert solvent for both reactants may be employed. Examples of appropriate solvents include amides and ethers; preferred solvents are ethers.
The catalyst compositions according to this invention can catalyze (1) the reaction between an isocyanate functionality and an active hydrogen-containing compound, such as, an alcohol, a polyol, an amine, or water; and (2) the trimerization of the isocyanate functionality to form polyisocyanurates. The compositions are especially useful as catalysts in the reaction between an organic polyisocyanate and a polyol and in the preparation of polyurethane foams in which an organic polyisocyanate reacts with a polyol in the presence of a blowing agent, such as water.
Polyurethane products are prepared using any suitable organic polyisocyanates well known in the art including, for example, hexamethylene diisocyanate, phenylene diisocyanate, toluene diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI). Especially suitable are the 2,4- and 2,6-TDI's individually or together as their commercially available mixtures. Other suitable isocyanates are mixtures of diisocyanates known commercially as "crude MDI", also known as PAPI, which contain about 60% of 4,4'-diphenylmethane diisocyanate along with other isomeric and analogous higher polyisocyanates. Also suitable are "prepolymers" of these polyisocyanates comprising a partially prereacted mixture of a polyisocyanate and a polyether or polyester polyol.
Examples of suitable polyols as a component of the polyurethane composition are the polyalkylene ether and polyester polyols. The polyalkylene ether polyols include the poly(alkylene oxide) polymers such as poly(ethylene oxide) and poly(propylene oxide) polymers and copolymers with terminal hydroxyl groups derived from polyhydric compounds, including diols and triols; for example, among others, ethylene glycol, propylene glycol, 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylol propane and like low molecular weight polyols.
In the practice of this invention, a single high molecular weight polyether polyol may be used. Also, mixtures of high molecular weight polyether polyols such as mixtures of di- and trifunctional materials and/or different molecular weight or different chemical composition materials may be used.
Useful polyester polyols include those produced by reacting a dicarboxylic acid with an excess of a diol, for example, adipic acid with ethylene glycol or butanediol, or reacting a lactone with an excess of a diol such as caprolactone with propylene glycol.
In addition to the polyether and polyester polyols, the masterbatch or premix compositions frequently contain a polymer polyol. Polymer polyols are used in polyurethane foam to increase the foam's resistance to deformation, i.e. to increase the load-bearing properties of the foam. Currently, two different types of polymer polyols are used to achieve load-bearing improvement. The first type, described as a graft polyol, consists of a triol in which vinyl monomers are graft copolymerized. Styrene and acrylonitrile are the usual monomers of choice. The second type, a polyurea modified polyol, is a polyol containing a polyurea dispersion formed by the reaction of a diamine and TDI. Since TDI is used in excess, some of the TDI may react with both the polyol and polyurea. This second type of polymer polyol has a variant called PIPA polyol which is formed by the in-situ polymerization of TDI and alkanolamine in the polyol. Depending on the load-bearing requirements, polymer polyols may comprise 20-80% of the polyol portion of the masterbatch.
Other typical agents found in the polyurethane foam formulations include chain extenders such as ethylene glycol and butanediol; crosslinkers such as diethanolamine, diisopropanolamine, triethanolamine and tripropanolamine; blowing agents such as water, methylene chloride, trichlorofluoromethane, and the like; and cell stabilizers such as silicones.
A catalytically effective amount of the catalyst composition is used in the polyurethane formulation. Suitable amounts of the catalyst composition may range from about 0.01 to 10 parts per 100 hundred parts polyol (phpp). Preferred amounts range from 0.05 to 1.5 phpp.
The catalyst composition may be used in combination with other tertiary amine, organotin and carboxylate urethane catalysts well known in the urethane art. For example, suitable gelling catalysts include but are not limited to trimethylamine, triethylamine, tributyl-amine, trioctylamine, diethyl cyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine (N-cocomorpholine), N-methyldiethanolamine, N,N-dimethylethanolamine, N,N'-bis(2-hydroxypropyl)piperazine, N,N,N',N'-tetramethylethylene-diamine, N,N,N',N'-tetramethyl-1,3-propanediamine, triethylenediamine (1,4-diaza-bicyclo[2.2.2]octane), 1,8-diazabicyclo(5.4.0)undecene-7, 1,4-bis(2-hydroxypropyl)-2-methylpiperazine, N,N'-dimethylbenzylamine, N,N-dimethylcyclohexylamine, benzyltriethylammonium bromide, bis(N,N-diethylaminoethyl)adipate, N,N-diethylbenzylamine, N-ethylhexamethyleneamine, N-ethylpiperidine, alpha-methylbenzyldimethylamine, dimethylhexadecylamine, dimethylcetylamine, and the like. Suitable blowing catalysts include but are not limited to bis(dimethylaminoethyl)ether, pentamethyidiethylenetriamine, 2-[N-(dimethylaminoethoxyethyl)-N-methylamino]ethanol, and the like. Suitable blowing catalysts include but are not limited to bis(dimethylaminoethyl)ether, pentamethyidiethylenetriamine, 2-[N-(dimethylaminoethoxyethyl)-N-methylamino]ethanol, and the like.
Following is a general polyurethane flexible foam formulation having a 1-3 lb/ft 3 (16-48 kg/m 3 ) density (e.g., foams used in automotive seating) containing a catalyst such as the catalyst composition according to the invention:
______________________________________Component Parts by Weight______________________________________Polyol 20-100 Polymer Polyol 80-0 Silicone Surfactant 1-2.5 Blowing Agent (e.g. water) 2-4.5 Crossslinker 0.5-2 Catalyst 0.5-2 Isocyanate Index 70-115*______________________________________ *Isocyanate Index = (mole isocyanate/mole active hydrogen) × 100
The invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the invention.
EXAMPLE 1
Preparation of 3-[3-(dimethylamino)propyl]-propionamide
A 50 ml 3 neck round bottom flask was fitted with the following: magnetic stirrer, reflux condenser, air bubbler, and a temperature controlled oil bath. The flask was charged with 7.1 g of acrylamide. 3-Dimethyl-1,3-propanediamine (10.2 g) was added in one portion to the reaction flask at ambient temperature. After the addition, the reaction mixture was stirred at 85° C. for 4 hours. The viscosity of the liquid increased by the end of the reaction. The mixture was cooled to ambient temperature. The resulting mixture was filtered through a Celite layer. The filtrate was collected for foam application. 1 H NMR showed that the product was the desired structure, and that there was no residual acrylamide.
EXAMPLE 2
Preparation of 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide
A 50 ml 3 neck round bottom flask was fitted with the following: magnetic stirrer, reflux condenser, air bubbler, and a temperature controlled oil bath. The flask was charged with 14.2 g of acrylamide. 3-Dimethyl-1,3-propanediamine (10.2 g) was added in one portion to the reaction flask at ambient temperature. After the addition, the reaction mixture was stirred at 101° C. for 8 hours and a slow stream of air was bubbled through the reaction mixture for the entire 8 hours. The mixture was cooled to ambient temperature. The resulting mixture was filtered through a Celite layer. The filtrate was collected for foam application. .sup. H NMR showed that the product was the desired structure, and that there was only 6.5% residual acrylamide, with no evidence for acrylamide polymer formation.
General Procedure for Preparation of Polyurethane Foams
Polyurethane foams were prepared in a conventional manner using the following premix formulation:
______________________________________Premix Formulation Component Parts by Weight______________________________________E-648 (ethylene oxide tipped polyether polyol, 60 marketed by Arco) E-519 (styrene-acrylonitrile copolymer filled poly- 40 ether polyol, marketed by Arco) Dabco ® DC-5043 (silicone surfactant marketed 1.5 by Air Products and Chemicals, Inc.) Diethanolamine 1.75 Water 3.25 TDI 80 (mixture of 80 wt. % 2,4-TDI and 20 wt. % 105 (isocyanate 2,6-TDI) index)______________________________________
For each foam, the catalyst was added to 202 g of the above premix in a 32 oz (951 ml) paper cup and the formulation was mixed for 20 seconds at 5000 RPM using an overhead stirrer fitted with a 2 inch (5.1 cm) diameter stirring paddle. Sufficient TDI 80 was added to make a 105 index foam [index=(mole isocyanate/mole active hydrogen)×100] and the formulation was mixed well for 5 seconds using the same overhead stirrer. The 32 oz. cup was dropped through a hole in the bottom of a 128 oz. (3804 ml) paper cup placed on a stand. The hole was sized to catch the lip of the 32 oz. cup. The total volume of the foam container was 160 oz. (4755 ml). Foams approximated this volume at the end of the foam forming process. Times to reach the top of the mixing cup (TOC1), the top of the 128 oz. cup (TOC2), and maximum foam height were recorded.
EXAMPLE 3
Preparation of foam using 3-[3-(dimethylamino)propyl]-propionamide as Gelling Catalyst
______________________________________ Full Foam TOC1 TOC2 Height Height Catalyst (sec.) (sec.) (sec.) (mm)______________________________________0.25 pphp DABCO 33LV.sup.a /0.10 12.74 44.02 127.27 409.05 pphp DABCO BL-11.sup.b 0.52 3-[3-(dimethylamino)propyl]- 12.02 45.65 133.91 404.89 propionamide/0.10 pphp DABCO BL-11______________________________________ .sup.a gelling catalyst; 33 wt. % triethylene diamine in dipropylene glycol .sup.b blowing catalyst; 70 wt. % Bis(N,Ndimethylaminoethyl) ether in dipropylene glycol.
EXAMPLE 4
Preparation of foam using 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide as Gelling Catalyst
______________________________________ Full Foam TOC1 TOC2 Height Height Catalyst (sec.) (sec.) (sec.) (mm)______________________________________0.25 pphp DABCO 33LV/0.10 12.74 44.02 127.27 409.05 pphp DABCO BL-11 0.52 pphp 3,3'-{[3-(dimethyl- 11.36 44.46 136.28 405.99 amino)propyl]-imino} bis- propanamide/0.10 pphp DABCO BL-11______________________________________
Examples 3 and 4 show that 3-[3-(dimethylamino)propyl]-propionamide and 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide are very effective gelling catalysts. | The use of 3-[3-(dimethylamino)propyl]-propionamide (Formula I) and 3,3'-{[3-(dimethylamino)propyl]imino}bis-propanamide (Formula II) as catalysts in the production of polyurethanes. ##STR1## | 8 |
BACKGROUND OF THE INVENTION
This invention relates to loading dock equipment. In particular, it is directed to a vehicle restraint which has a security device to prevent unauthorized removal of a trailer from a loading dock.
PRIOR ART
The use of a vehicle restraint as a safety device to prevent a truck or trailer from inadvertently moving away from a loading dock is well known. Most vehicle restraints consist of a hook shaped member which is placed in front of the ICC bar of a trailer to limit horizontal motion. To accommodate vertical motion caused by suspension deflection under varying loads, the hook is usually spring biased upward to maintain contact with the ICC bar.
Although safety at the dock is an obvious requirement, another serious problem for shippers is the theft of trailers which are left unattended at a loading dock. This is of particular concern when the cargo is of high value. For example, a trailer loaded with alcohol, tobacco or consumer electronic products may have a value exceeding a half million dollars. A vehicle restraint typically has the strength to prevent a trailer from being pulled away from the dock, but because the restraint is usually spring biased upward to maintain contact with the ICC bar, the hook portion can be deflected downward to disengage the ICC bar and allow the trailer to be removed.
Some vehicle restraints have been used to discourage theft of an unattended trailer by preventing the hook from disengaging the ICC bar. In these situations an operator is required to climb under the rear of the trailer and install a padlock or other locking device. This is usually an awkward location to access, wet and dirty in inclement weather, and potentially unsafe. Also the difficulty of installation and removal of the locking device may discourage consistent use and allow the trailer to remain unsecured. Additionally, the use of many of these locks essentially disables the vehicle restraint so that if loading operations resume without removing the lock, potential damage can occur to the restraint or the device may bind on the ICC bar.
SUMMARY OF INVENTION
This invention is a vehicle restraint which incorporates a security device to deter the disengagement of the restraint from the ICC bar of the trailer. It also provides for the electrical monitoring of the device to warn of tampering.
This invention does not compromise the primary safety function of the vehicle restraint, to secure the trailer at the loading dock. It however extends the utility of these devices by providing an addition aspect of functionality, namely a theft prevention device at the same time.
As with any security device, it is understood that this invention cannot prevent the forcible removable of the trailer by extreme unlawful measures such as cutting the ICC bar on the trailer or mechanically disassembling the vehicle restraint. However, it does offer a significant deterrent to theft by making removal of the vehicle restraint more difficult, time consuming and potentially hazardous itself as a part of any theft. In addition, attempts to tamper with the device will activate switches which may be used to enable an alarm system.
It is therefore an object of this invention to provide a vehicle restraint that has an integral security system used in conjunction with the actuating mechanism that can automatically initiated.
Yet another aspect of this invention is to provide a vehicle restraint having a security system which does not require the operator to manually place or insert additional elements onto the restraint to secure it as a theft prevention device.
In accordance with this invention a vehicle restraint is provided to prevent movement of a vehicle from a parked position has a frame mountable at a loading dock to position a vehicle restraint mechanism operably coupled to the frame. The vehicle restraint mechanism has a restraining member with at least one hook movable between a lower inoperative position where said restraining member is out of contact with a vehicle to be restrained and an upper operative position where the restraining member contacts said vehicle and prevents movement from a parked position. A source of power, such as an actuator moves the restraining member upward to the operative position by having linkage coupling the source of power to the restraining member. A resilient member is coupled to the linkage and biases the restraining member into engagement with the vehicle. A security member is movable from a stored position to a blocking position preventing movement of the linkage in one direction thereby preventing the restraining member from lowering into the inoperative position and a spring member biases the security member into engagement with the linkage to prevent downward movement of the restraining member.
This invention will be described in greater detail by referring to the attached drawing and the description of the preferred embodiment that follows.
DESCRIPTION OF THE DRAWING
FIG. 1 is a side view, partially cutaway, illustrating the vehicle restraint in a normal operative position in accordance with a first preferred embodiment of this invention;
FIG. 2 is a sectional side view showing the restraint mechanism of the first preferred embodiment;
FIG. 3 is an enlarged view of the security locking components of the first preferred embodiment of this invention;
FIG. 4 a top view of the device in FIG. 1;
FIG. 5 is a side view illustrating the vehicle restraint of the first preferred embodiment in the first of three steps of engagement of the security system;
FIG. 6 is side view illustrating the vehicle restraint of the first preferred embodiment with the lock bar extended below the actuating pin of the restraint mechanism;
FIG. 7 is side view illustrating the vehicle restraint of the first preferred embodiment with the lock bar engaged to prevent the restraint mechanism from lowering;
FIG. 8 is side view illustrating the second preferred embodiment of a vehicle restraint in a stored inoperative position;
FIG. 9 is a sectional side view showing the restraint mechanism of the second preferred embodiment in the operative position;
FIG. 10 is an enlarged view of the vehicle restraint of the second preferred embodiment with the security locking feature engaged;
FIG. 11 is an enlarged view of the vehicle restraint of the second preferred embodiment with a modification of the security locking feature; and
FIG. 12 is an enlarged view of the vehicle restraint of FIG. 11 with the security locking feature engaged.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1-7 a first preferred embodiment of this invention will be described. The general description of the vehicle restraint components per se are same as found in U.S. Pat. No. 5,336,033, commonly assigned, which is expressly incorporated herein by reference. Particular attention in the '033 patent is directed to FIGS. 6-8 for a desription of the operation of that device.
A vehicle restraint assembly is mounted on a dock wall `A` with the hook assembly 15 biased upwardly to engage the ICC bar 25 of a trailer as shown in FIG. 1. FIG. 2 is a sectional view of the vehicle restraint showing the restraint mechanism. The main arm assembly 5 pivots about the shaft 45 mounted in the frame side plates 1 and 2, and is upwardly biased by a pair of gas springs 24. The upper arm assembly 10 is attached to the main arm assembly 5 by a pin 12 and to the front strut 7 by a pin 13. The front strut is anchored to the frame assembly side plates by a pin 8. The hook assembly 15 is mounted to the upper end of the upper arm by a pin 14 and is held horizontal by the hook struts 18 which are carried by pins 19 and 20.
The hook assembly 15 has a plate 16 which carries a sensor plate 20. The sensor plate is guided by a bolt 21 through the plate 16 and is biased upward by a spring 22. A limit switch 23 senses when the plate 20 is depressed by the ICC bar 25 and passes an electrical signal to a control panel (not shown) to indicate that the vehicle restraint has engaged the ICC bar 25.
As shown in FIGS. 1, 2 and 3, the main arm assembly 5 carries a pin 41 which passes through a slotted hole 44 in the side plate 2. The sector plate assembly 60 pivots on the shaft 45 and has two lugs 62 and 63 which engage the pin 41 to control the rotation of the arm 5. When the vehicle restraint is in the normal operative mode, the sector plate assembly 60 is stationary and the pin 41 is free to move between the lugs 62 and 63 as the mechanism follows the vertical motion of the ICC bar.
FIG. 3 shows an enlarged view of the sector plate assembly 60 which comprises the sector plate 61, an arm 64, a mounting plate 65 and a bushing 66. A latch plate assembly 70 is carried on the sector plate 61 by a pin 72. The latch plate 71 has a latch surface 73 and an actuating lug 74. An electric solenoid assembly 75 has a housing 76 mounted to the plate 65 and an extendable plunger 77. A spring 78 holds the latch plate assembly 70 in an inoperative position against the retracted plunger 77. FIG. 1 also shows an actuator mounting arm assembly 55 with two arms 56 and a switch target bracket 57, The arm assembly is carried by a pin 51 mounted on the side plate 2. The arm assembly 55 is biased counter-clockwise against the lug 52 on the side housing 2 by the spring 80 which is compressed by the bolt 81 and nut 82.
An electrical actuator 36 has one end mounted to the end of the arm assembly 55 by the pin 40, and the other end fastened to the sector plate assembly by the pin 38. Two limit switches 85 and 86 are attached to the side plate 2. In the normal operative mode, the force of the spring 80 is sufficient to resist the operating forces of the actuator 36, maintaining the arm assembly 55 in contact with lug 52 and preventing the target bracket 57 from activating the limit switch 85.
FIG. 5 shows the vehicle restraint during the first step of activating the security feature. The functions of the vehicle restraint are controlled from a control panel (not shown), preferably using a programmable logic controller (PLC) which allows predetermined output functions depending on signals created by limit switches and control switches. When the security function is selected on the control panel, the electric actuator 36 extends until the lug 62 engages the pin 41. When the hook assembly 15 has been pulled from engagement with the ICC bar, the sensor plate 20 is raised by the spring 22 and the limit switch 23 no longer sends an electrical signal. The electric solenoid 75 is then energized and the plunger 77 forces the latch plate assembly 70 to rotate counterclockwise until it engages the pin 41 as shown in FIG. 7.
The actuator 36 then retracts and forces the lock surface 73 against the bottom of the pin 41, raising the hook assembly 15 upward. The actuator 36 continues to retract until the arm assembly 55 rotates forward and the target bracket 57 activates the limit switch 85 and the actuator 36 is stopped. Preferably the spring 80 has a dual spring rate so that the force of the actuator 36 is sufficient to move the arm assembly 55 to the position shown in FIG. 6, but any attempt to move the hook 15 downward to disengage the ICC bar will be resisted by significantly higher force. The purpose of the spring 80 is to maintain a high engagement force against the ICC bar yet allow downward deflection to compensate for settling of the trailer suspension without damaging the vehicle restraint mechanism.
Any attempt to raise the trailer or the ICC bar will allow the hook 15 to raise and cause the spring 80 to return the arm assembly to the initial position. The target bracket 57 will cease to engage the limit switch 85 and the electric actuator will again retract to maintain the upward force.
When the security mode is turned off, the actuator 36 extends again and the latch plate assembly 70 is retracted by the spring 78 to the position shown on FIG. 5. When the sensor plate 20 has lost engagement with the ICC bar 25, the actuator 36 then extends to the normal operative mode as shown in FIG. 1.
The vehicle restraint with the security device is also equipped with several features to detect tampering. The limit switches 23, 85 and 86 are normally open and are closed when activated. Thus cutting electrical wires or losing contact with the ICC bar will result in a loss of electrical signal to the control panel, and may be used to trigger an alarm system as illustrated in FIG. 1. Any attempt to raise the trailer or the ICC bar which causes the electric actuator to retract may also trigger the alarm system. Any attempt to force the hook 15 downward to disengage the ICC bar will cause actuator 36 to pull the arm assembly 55 farther clockwise and allow the target bracket 57 to activate the limit switch 86 and enable the alarm system.
A second embodiment of the security locking device is shown in FIGS. 8-12 with a retractable vehicle restraint assembly which is mounted in a recessed pit below the dock leveler. Reference is made to U.S. Pat. No. 5,505,575, which is expressly incorporated by reference, to illustrate and describe the basic structure and operation of that type of vehicle restraint.
FIG. 8 illustrates the vehicle restraint in a stored inoperative position. FIG. 9 illustrates a sectional view of the same vehicle restraint in the operative position engaging the ICC bar 25 of a transport vehicle. FIGS. 8 and 9 show a driveway 101, a dock face 102 and a dock floor 103. A pit 104 having a rear wall 105 is recessed under the dock floor 103. There may also be a larger pit 107 for a dock leveler not shown. The vehicle restraint has a frame assembly 110 having a back plate 111 which is attached to the rear wall 105. Two side plates 112 are attached to the back plate 111 and carry the other components of the vehicle restraint. A main arm assembly 120 pivots about a pin 115 which is carried by the side plates 112. The arm assembly 120 has two arms 121 and two support plates 122 which are joined together by the crossbars 123, 124 and 125 as shown in FIGS. 8 and 9. The arms 121 have two elongated slots 126 and 127 which carry pins 137 and 138. A pair of gas springs 24 have one end attached to the frame assembly 110 and the other end to the main arm assembly 120, causing the main arm assembly to be biased upward. An actuating arm 128 pivots on the pin 115. An electrical actuator 36 is attached to the frame assembly 110 by the pin 116 and to the actuating arm 128 by the pin 38. The end of the actuating arm 128 is positioned between the cross bars 123 and 124 and, when the actuator 38 is retracted, the end of the arm 128 engages the crossbar 124 and the main arm assembly 120 is held down in the stored position shown in FIG. 8.
A main hook assembly 130 has two side plates 131 joined by a plate 132. The hook assembly 130 is carried by the pins 137 and 138 and can be extended and retracted relative to the main arm assembly 120, guided by the slots 126 and 127. The motion of the main hook assembly 130 is controlled by a second electric actuator 140 which is attached at one end to the main arm assembly 120 by the pin 117 and at the other end to the main hook assembly 130 by the pin 141. A secondary hook 135 pivots about the pin 137 and is biased upward by the spring 139 which is compressed between the main hook assembly 130 and the lug 137 on the secondary hook 135.
The upper surface 136 of the hook 135 projects above the top surface of the main hook assembly 120 as shown in FIG. 8. When the main hook assembly 130 engages an ICC bar 25, as illustrated in FIG. 9, the surface 136 of the secondary hook 135 is depressed and the motion of the secondary hook is sensed by an electrical switch (not shown) to indicate contact with the ICC bar 25.
The security function is provided by the arm 145 which pivots about the pin 115 and is controlled by a third electric actuator 150 which is attached to the arm 145 by the pin 146. The other end of the actuator 150 is attached by the pin 148 to a clevis 149 which is held by a bolt 81 through a bracket assembly 160 attached to the floor of the pit 104. The bracket assembly 160 has a base plate 161, a vertical plate 162 and a limit switch mounting plate 163. The clevis 149 is held against the plate 162 by the compression spring 80 and the nut 82. Two limit switches 85 and 86 are attached to the plate 163, and a target bracket 57 is attached to the clevis 149.
The inoperative position of the arm 145 as shown in FIGS. 8 and 9 allows the vehicle restraint to function in the normal manner. When the vehicle restraint has engaged as ICC bar 25 and the security function is engaged, the actuator 150 pulls the arm 145 into contact with the crossbar 125, preventing the main arm assembly 120 and the hook assembly 130 from lowering. The actuator 140 retracts until the clevis 149 moves away from the plate 162 and the target bracket 57 activates the limit switch 85, stopping the actuator. Any attempt to move the hook assembly 130 downward to disengage the ICC bar 25 will be resisted by the force of the spring 80. As described earlier, the purpose of the spring 80 is to maintain a high engagement force against the ICC bar yet allow downward deflection to compensate for settling of the trailer suspension without damaging the vehicle restraint mechanism.
Any attempt to raise the trailer or the ICC bar will allow the hook assembly 130 to raise and cause the spring 80 to return the clevis 149 arm assembly to the initial position. The target bracket 57 will cease to engage the limit switch 85 and the electric actuator 140 will again retract to maintain the upward force. The limit switches 185 and 186 provide the same features to detect tampering as described previously. When the security mode is turned off, the actuator 140 extends again restores the arm 145 to the inoperative position shown in FIG. 9.
FIGS. 11-12 illustrate a third embodiment of this invention employing the same vehicle restraint as in the second embodiment but with a simplified security device. The actuator 150 and the arm 145 are replaced with a rack bar 155 having a number of teeth 156. The crossbar 125 has an opening with the lower edge beveled to form a pawl 126. The rack bar 155 is held up in the inoperative position shown in FIG. 11 by a control rod or cable 157. The control rod can be held by a mechanical lever or latch mechanism (not shown). The security function is activated by releasing the control rod 157 and allowing the rack bar 155 to fall so that one of the teeth 156 engages the pawl 126 as shown in FIG. 12. Any attempt to force the hook 120 to lower will cause the rack 155 to pull the clevis 149. If the force exceeds the compression of the spring 80, the clevis 149 will move and cause the target bracket 58 to engage the limit switch 186 to trigger an alarm.
The absence of the limit switch 185 to sense engagement does not provide this third embodiment the same level of security as the other embodiments, but demonstrates a simple manually operated security method which does not require an additional means of powered actuation.
It is apparent that modifications of this invention may be practiced without departing from the essential scope of this invention. | A vehicle restraint for preventing movement of a vehicle from a parked position has a frame mountable at a loading dock to position a vehicle restraint mechanism operably coupled to the frame. The vehicle restraint mechanism has a restraining member with at least one hook movable between a lower inoperative position where said restraining member is out of contact with a vehicle to be restrained and an upper operative position where the restraining member contacts said vehicle and prevents movement from a parked position. A source of power, such as an actuator moves the restraining member upward to the operative position by having linkage coupling the source of power to the restraining member. A resilient member is coupled to the linkage and biases the restraining member into engagement with the vehicle. A security member is movable from a stored position to a blocking position preventing movement of the linkage in one direction thereby preventing the restraining member from lowering into the inoperative position and a spring member biases the security member into engagement with the linkage to prevent downward movement of the restraining member. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention:
[0002] The invention relates generally to measurement-while-drilling apparatus used in earth boring operations. In various measurement-while-drilling apparatus information about downhole conditions is telemetered to the surface of the bore by means of pressure changes (“mud pulses”) in the drilling fluid (“mud”) which is circulated through the drill sting and annulus of the bore during drilling. Such mud pulses are typically created by alternatively restricting and unrestricting the flow of mud through a downhole valve (“mud valve”). In various MWD systems actuation of the mud valve is accomplished through use of hydraulic system. The invention disclosed and claimed herein relates to an improved hydraulic system for actuation of an MWD mud valve.
[0003] 2. Description of Related Art:
[0004] In the field of earth boring, MWD apparatus are employed to obtain information about downhole conditions, such as wellbore inclination angle, magnetic heading, orientation of the bottom-hole assembly, formation radioactivity, resistivity and porosity without the necessity of interrupting drilling operations. To accomplish that end, MWD apparatus typically employ sensors located as close as practical to the drill bit, means to encode the sensed data into a pulse format, and means to telemetry the data pulses to the surface. A common means of telemetering such data to the surface is by causing back-pressure changes (“mud pulses”) to occur in the drilling fluid (“mud”) which is circulated during drilling. In such means at least a portion of said drilling fluid is flowed through a mud valve located downhole, which valve is alternatively actuated between two positions (alternatively “restricting” and “unrestricting” the flow of drilling fluid through the mud valve). This causes corresponding changes in back-pressure (“mud pulses”) of the drilling fluid.
[0005] These mud pulses may be detected at the surface of the bore and decoded to retrieve information about downhole conditions.
[0006] In certain forms of MWD apparatus, actuation of the mud valve is accomplished by means of a hydraulic system. U.S. Pat. Nos. 4,266,606, 3,756,076, 3,737,843 and 3,693,428 disclose hydraulic systems for operation of an MWD mud valve. In these patents the piston of the linear hydraulic actuator is operatively coupled to the poppet of a poppet-seat type mud valve. When hydraulic pressure is applied to one side of the piston, the piston moves to one end of the actuator which causes the poppet to move towards the seat of the mud valve. Reducing the gap between the poppet and seat causes back pressure of drilling fluid to increase. Alternatively, when hydraulic pressure is applied to the opposite side of the piston, the piston moves to the other end of the actuator, increasing the gap between the poppet and seat, causing back pressure of the drilling fluid to decrease. No means is provided in these patents to by-pass hydraulic fluid through the actuator after its piston has stroked a desired amount. Rather in operation, full hydraulic pressure is continuously applied to either one or the other side of the piston.
[0007] U.S. Pat. No. 6,050,349 discloses a hydraulic system for operating a hydraulic actuator of rotary configuration. When hydraulic pressure is applied to one side of a vane type piston, the piston rotably moves to the opposite side of the actuator and closes a mud valve port, causing back pressure of the drilling fluid to increase. When hydraulic pressure is applied to the opposite side of the actuator, reverse movement and effect occurs. Similar to the above patents, the actuator of this patent contains no means to by-pass hydraulic fluid through the actuator after piston has stroked in either direction. Rather during operation hydraulic pressure continuously loads either one or the other side of the piston, continuously loading the hydraulic system.
[0008] Continuous loading of the hydraulic system constitutes a source of heat which can be degrade performance of the hydraulic system or damage equipment, particularly in high temperature drilling conditions. The invention disclosed and claimed herein is directed toward this issue.
SUMMARY OF THE INVENTION
[0009] The invention features an improved hydraulic system for actuation of a measurement-while-drilling mud valve in which by-pass means provides for reduction of hydraulic load at a desired amount of actuator stroke. The hydraulic system includes a means for driving a hydraulic pump, a hydraulic pump, a valve for switching flow of hydraulic fluid between ports of a hydraulic actuator and a hydraulic actuator operatively coupled an MWD mud valve in which a by-pass means reduces hydraulic loading following a desired amount of actuator stroke. The system may include filtering or straining means, high pressure by-pass means, hydraulic reservoir and/or means to equalize the static pressure of the hydraulic system with the pressure of the surrounding environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1A is schematic representation of one embodiment of the hydraulic system of the present invention (showing a linear actuator in extended position).
[0011] [0011]FIG. 1B is schematic representation of the same embodiment of the invention as is illustrated in FIG. 1A, but with the linear actuator in retracted position).
[0012] [0012]FIGS. 2A and 2B are schematic representations of an alternative embodiment of the hydraulic system of the present invention (showing a linear actuator having dual by-passes).
[0013] [0013]FIGS. 3A, 3B, 3 C and 3 D are schematic representations of an alternative rotary actuators of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] While the present invention will be described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. It is therefore intended that the present invention not be limited to the particular embodiments disclosed herein, but that the invention will include all embodiments (and legal equivalents thereof) falling within the scope of the appended claims.
[0015] [0015]FIG. 1( a ) describes the hydraulic system of a preferred embodiment of the present invention. In FIG. 1( a ) prime mover 100 drives hydraulic pump 101 . In a preferred embodiment of the invention the prime mover 100 is a turbine driven by circulating drilling fluid (“mud turbine”), but it may be several other means such as electric motor, driven by battery or alternator, or various other suitable motive or power means.
[0016] The output of hydraulic pump 101 is hydraulically coupled to flow control valve 103 . In a preferred embodiment of the invention flow control valve 103 is operated by solenoid 103 ( a ) responsive to electrical signals representing encoded data, but may be operated by other suitable means, such as mechanical, pneumatic or hydraulic means in which data may be encoded.
[0017] In a preferred embodiment of the invention when flow control valve 103 is in one position, then fluid flow is from P to A and A into port C, urging piston 104 ( e ) toward the opposite end (the “D end”) of cylinder body 104 ( a ). As piston 104 ( e ) moves towards the D end of cylinder body 104 ( a ), hydraulic fluid in cavity 104 ( d ) flows from port D, through B and T, through strainer 107 and back to the inlet of pump 101 . In a preferred embodiment of the invention the piston 104 ( e ) is slightly less than one-half the desired stroke of the piston, and by-pass port E is positioned intermediate the ends of the stroke. Accordingly as the leading edge of piston 104 ( e ) reaches a desired stroke towards the D end of cylinder body 104 ( a ), its trailing edge clears port E, opening it to the passage of hydraulic fluid. When port E opens, a by-pass hydraulic loop is formed from the outlet of pump 101 , through P, A, C, E, strainer 107 and back to the inlet of the pump 101 , unloading the hydraulic system.
[0018] When flow control valve 103 is shifted to the other position, hydraulic pressure from pump 101 flows from port P to B and from B into port D, urging piston 104 ( e ) toward the opposite end (the “C end”) of cylinder body 104 ( a ). As piston 104 ( e ) begins travel to the C end of cylinder body 104 ( a ), hydraulic fluid in cavity 104 ( c ) is returned to the inlet of pump 101 through ports C, A and T. As piston 104 ( e ) nears the end of its stroke toward the C end of cylinder body 104 ( a ), the trailing end of the piston 104 ( e ) again clears port E, again opening it, unloading the hydraulic system.
[0019] In the event it is desirable to maintain a residual pressure on piston 104 ( e ) after it has stroked, such as may be the case where pressure forces of the drilling fluid or vibrational forces may cause undesired movement of piston 104 ( e ), that may be accomplished by flow restrictor 105 , by sizing port E down, by selecting small line size from port E to inlet of pump 101 , by pressure limiting relief valve or other conventional means for maintaining back pressure in a fluid line.
[0020] [0020]FIG. 2A and 2B, illustrate an alternative embodiment of the invention in which port E is essentially bifurcated into two ports, E 1 and E 2 , one of which unloads the hydraulic system when piston 104 ( e ) has stroked in one direction and the other which unloads the hydraulic system when piston 104 ( e ) is stroked in the other direction. By employing two by-pass ports as shown, each may be differently restricted, for example by flow restrictors 105 a and 105 b, to maintain a differing back-pressures on piston 104 ( e ) depending on which direction it is stroked.
[0021] [0021]FIGS. 3A and 3B illustrate a rotary type mud valve actuator as may be employed in yet another preferred embodiment of the invention. With control valve 103 in one position hydraulic fluid flows to port C, urging rotary piston 204 ( e ) towards the D end of cylinder housing 204 ( a ). During initial movement of piston 204 ( e ) from the C end toward the D end of the cylinder body 204 ( a ), port E is covered by piston 204 ( e ), closing port E. As the leading edge of the piston 204 ( e ) nears the end of its stroke, its trailing edge clears port E, permitting hydraulic fluid to pass from C to E. When hydraulic fluid is directed to port D the reverse movement occurs. It will be understood by those skilled in the art that by increasing the chord of piston 204 ( e ), port E could again be bifurcated into two ports, each of which may have separate flow restrictor 105 for maintaining differing residual pressures on piston 204 ( e ) depending on which way it has stroked. FIG. 3C and 3D are yet another preferred embodiment of a rotary type actuator which may be employed in the invention. In this embodiment plate 204 ( f ), operatively coupled to a vane type piston, is employed to open port E upon desired stroke of the piston in either direction. It will be understood by those skilled in the art that stroke of the piston in any of the embodiments to the invention may be less than full length of cylinder body. It will also be appreciate by those skilled in the art that any of the ports of the present invention may consist of one or several openings.
[0022] Embodiments of the invention may also be equipped with pressure compensation means 106 , strainer means 107 and high pressure relief means 102 . Pressure compensation means 106 , preferably includes hydraulic fluid reservoir 106 ( a ) which is physically separated from, but in pressure communication with, drilling fluid pressure through pliable membrane, bellows, piston or the like of 106 ( b ).
[0023] Strainer 107 may consist of any conventional means used to remove particulate material or cohesive masses from hydraulic fluid. It will be understood by those skilled in the art that in lieu of or in addition to strainer means in line with the inlet of the pump a filter means my be disposed in line with the outlet thereof.
[0024] Embodiments of the invention may also be equipped with high pressure by-pass means 102 to protect the system from damaging over-pressure in the event of malfunction of one or more other components of the system.
[0025] It is thus to be appreciated that a hydraulic system constructed in accordance with the principles and teachings of the present inventive disclosure constitutes an advancement in field of art to which the invention pertains. While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of preferred embodiments thereof. Accordingly, the scope of the present invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents. | The hydraulic system for actuation of the mud valve of a measurement-while-drilling tool is characterized by a hydraulic actuator having a piston operatively connected to the mud valve of a measurement-while-drilling tool, which hydraulic actuator incorporates an internal by-pass which, cooperatively with movement of the piston, opens to unload hydraulic pressure from the system at either end of stroke of the piston. Return from the by-pass to the pump may be restricted so as to maintain some hydraulic pressure on the piston at end of stoke so as to prevent movement therefrom by external forces. The hydraulic system may include high pressure means, strainer means and means to equalize pressure between hydraulic system pressure and pressure external of the system. | 5 |
This utility application claims the benefit of the filing date of U.S. Provisional Application No. 60/667,982, filed Apr. 4, 2005.
RELATED PATENT APPLICATIONS
U.S. patent application Ser. No. 10/947,671, filed Sep. 23, 2004, entitled “Radar Absorbing Electrothermal Deicer” and assigned to the same assignee as the instant application, which related application being incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
Electrothermal heating has become an effective choice for airfoil and structure deicer heaters, especially when composite materials are used for the airfoils and/or other structures being deiced. An electrothermal heater may be used wherever icing conditions exist, including applications such as: airfoil leading edges of wings, tails, propellers, and helicopter rotor blades; engine inlets; struts; guide vanes; fairings; elevators; ships; towers; wind turbine blades; and the like, for example. In electro-thermal deicing systems, heat energy is typically applied to the surface of the airfoil or structure through a metallic heating element via electrical power supplied by aircraft or appropriate application generators. Typical heating elements are made from foil, wire, or metallic-coated fabrics.
Generally, the electro-thermal heater deicers may be implemented in a conductive pattern over or under the skin of the airfoil or other structure, or embedded in the composite material itself. The electrothermal deicer pattern, being conductive, has a tendency to give off a larger than desired cross-sectional radar image in response to radar illumination. This has become a particular problem when such deicer heater patterns are applied to military aircraft that may be illuminated by enemy radar systems. Accordingly, it is desired to keep the radar cross-section of an aircraft as small as possible.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a heater conductor for electrothermal deicing of a structure is coated with at least one layer of dielectric material filled with magnetic particles.
In accordance with another aspect of the present invention, electrothermal deicing apparatus comprises: at least one heater conductor, each conductor coated with at least one layer of dielectric material filled with magnetic particles; and a heater controller coupled to the at least one heater conductor for controlling the heating thereof.
In accordance with yet another aspect of the present invention, electrothermal deicing apparatus comprises: at least one heater conductor formed into a predetermined pattern for application to a structure, each conductor of the pattern coated with at least one layer of a material active to absorb electromagnetic energy, the pattern of the at least one coated heater conductor is operative to attenuate radar wave transmissions incident thereon to reduce the radar cross-section of the structure; and a heater controller coupled to the pattern of at least one coated heater conductor for controlling the deicing of the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layered, isometric perspective illustration of an exemplary coated heater conductor.
FIG. 2 is a layered, isometric perspective illustration of an exemplary coated heater wire having a plurality of coating layers.
FIG. 3 is a layered, isometric perspective illustration of an alternate coated heater wire having a plurality of coated layers.
FIG. 4 is a layered, isometric perspective illustration of an exemplary coated heater conductor of rectangular cross-section.
FIG. 5 is an exemplary heater element pattern of coated heater conductors.
FIG. 6 is a cross-sectional schematic illustration of an exemplary electrothermal deicing apparatus utilizing a pattern of coated heater conductors.
FIG. 6A is a cross-sectional schematic illustration of an alternate electrothermal deicing apparatus utilizing a pattern of coated heater conductors.
DETAILED DESCRIPTION OF THE INVENTION
In order to alleviate the cross-sectional radar image issue of electro-thermal heater patterns for aircraft airfoils and/or other structures, the electromagnetic properties of the resistance heater conductors thereof may be modified with coating materials to provide a high magnetic and electrical energy loss which is designed to occur when an applied electromagnetic wave of energy, like radar illumination, for example, is applied at a desired frequency of utilization (Mhz to Ghz) and over a broadband range to maximize absorption of electromagnetic energy and thus, reduce the radar cross-section of the aircraft. The conductor and coating materials are designed primarily to act as an element of an electrical resistance heater for the preferred use of integration into composite non-metallic structures. In such structures, the electro-thermal heater element may be protected from physical damage and environmental corrosion by embedding it in a dielectric polymer within the composite material of the airfoil or structure.
An exemplary embodiment of a heater conductor 10 is shown in the layered, isometric perspective illustration of FIG. 1 . Referring to FIG. 1 , in the present embodiment, the heater conductor 10 comprises a wire 12 which may be made from any metal of desired electrical resistance with the preferred metals being ferromagnetic and made up of transition metals iron, cobalt, nickel, chromium and rare earth metals, for example. Preferably, the heater wire 12 may be a single strand 33 AWG wire of alloy Nickel 60%, Chromium 16%, Iron 24% with properties of 675 ohms per CMF at 20° C., for example. The heater wire 12 may be coated as shown with at least one coating layer 14 of dielectric material filled with magnetic particles, not previously known to the wire coating industry.
The filled coating layer 14 may comprise any dielectric insulating material such as elastomers, ceramics, or polymeric films like polyimide films, polyester films or amide imide films, for example. The magnetic filler particle, which may be carbonyl iron, iron silicide, ferrite or rare Earth magnetic particles and combinations thereof, for example, may be selected and processed to reduce particle size to less than 10 microns to allow the coating process through wire die applicators and still maintain effective electromagnetic/radar absorbing performance. Optionally, the wire 12 may be coated with one or more unfilled insulating layers 16 prior to being coated with the magnetic particle filled layers 14 . In the exemplary embodiment shown in FIG. 1 , an initial coating of an unfilled polyester layer 16 is applied to the wire 12 , then one or more coatings of a magnetic particle filled amide imide layers 14 are applied over the unfilled layer 16 .
The coating layers 14 and 16 may be applied to the wire in various designs of multiple coating layers and thicknesses, which may total approximately 0.0018-0.0020 inches thick or greater on an approximate 0.0070 inch diameter wire, for example. One exemplary coated wire design is shown in the layered, isometric perspective illustration of FIG. 2 . Referring to FIG. 2 , a wire conductor 20 , having an outside dimension of 0.006954 inches, for example, undergoes five (5) passes of coating layers of an unfilled polyester material to produce an initial five dielectric coating layers 22 , and then undergoes three (3) passes of coating layers of a magnetic particle filled material as described infra to produce the final three coating layers 24 . The film build up of all eight (8) coating layers 22 and 24 for this example may be approximately 0.002018 inches, for example, yielding an overall coated wire 26 with an outside dimension of 0.008972 inches.
Another exemplary coated wire design is shown in the layered, isometric perspective illustration of FIG. 3 . Referring to FIG. 3 , a wire 30 , having an outside dimension of 0.006959 inches, for example, undergoes one (1) pass of coating layer of the unfilled polyester material to produce an initial single dielectric coating layer 32 , and then undergoes seven (7) passes of coating layers of the magnetic particle filled material as described infra to produce the final seven coating layers 34 . The film build up of all eight (8) coating layers for this example may be approximately 0.001875 inches, for example, yielding an overall coated wire 36 with an outside dimension of 0.008834 inches.
The geometric cylinder shape of a round wire conductor as shown in FIGS. 1 , 2 and 3 is inherently reflective to radar illumination and provides additional specular design characteristics to the electromagnetically active coating layers. However, it is understood that the heater conductor of the present embodiment need not be round in cross-section, but rather take upon many different cross-sectional shapes without deviating from the broad principles of the present invention. An example of a heater conductor having a rectangular cross-sectional shape is shown in the layered, isometric perspective illustration of FIG. 4 . Referring to FIG. 4 , a rectangular cross-section conductor 40 may be coated with a layer 42 of dielectric material filled with magnetic particles in a similar manner as the wire conductor embodiment of FIG. 1 described herein above. An initial coating of an unfilled layer 44 of dielectric material is optional.
One or more conductors coated with the electromagnetically active layers, as described in connection with the embodiments of FIGS. 1 , 2 , 3 and 4 above, may be disposed in a heater element pattern for use in an electrothermal deicing apparatus. An exemplary heater element 50 patterned with a plurality of conductors having electromagnetically active layers is illustrated in FIG. 5 . The lines of FIG. 5 represent the coated heater conductors. FIG. 6 is a cross-sectional, schematic illustration of an exemplary electrothermal deicing apparatus 60 utilizing the heater element 50 .
Referring to FIG. 6 , the deicing apparatus 60 comprises the pattern of heater conductors 50 which may be disposed at, under or over a surface 62 of a structure 64 which may be any of the structures enumerated in the Background section hereof. The coated conductors of heater element pattern 50 may form electrical circuits when coupled to a deicing system 66 over connecting leads 68 . The deicing system 66 may control the voltage and current to the electrical circuits of the heater element 50 via leads 68 to heat and protect the surface 62 of structure 64 from accumulating ice while the electromagnetically active coated heater conductors of the heater element 50 offer an attenuation to radar wave transmissions which may be focused thereat, thus reducing its radar cross-section. If the structure 64 is a composite, non-metallic structure, the heater element 50 may be embedded or integrated into the structure 64 of an alternate electrothermal deicing apparatus 70 as shown by the cross-sectional, schematic illustration of FIG. 6A in which reference numerals of like elements remain the same.
The radar absorption method of the present embodiments is new and unique employing a hybrid technique of radar absorbing material (RAM), circuit analog absorber (CA) and graded dielectrics on a ferromagnetic electrical conductor with design flexibility to produce light weight radar absorbing characteristics. The coated heater conductor of the present embodiment is designed to have the dual use of electrical heating and radar wave or electromagnetic energy absorbing applications. It has a secondary use for electromagnetic interference (EMI) shielding applications and may be useful where heater applications in close proximity to electrical controls or sensors may require EMI shielding.
While the present invention has been described herein above in connection with a plurality of embodiments, it is understood that such description is presented merely be way of example. Accordingly, the present invention should not be limited in any way by the embodiments described herein above, but rather construed in breadth and broad scope in accordance with the recitation of the appended claims. | An electrothermal deicing apparatus includes at least one heater conductor formed into a predetermined pattern for application to a structure. Each conductor of the pattern is coated with at least one layer of a material active to absorb electromagnetic energy. The pattern of the at least one coated heater conductor is operative to attenuate radar wave transmissions incident thereon to reduce the radar cross-section of the structure. A heater controller is coupled to the pattern of at least one coated heater conductor for controlling the deicing of the structure. | 7 |
FIELD OF THE INVENTION
The present invention relates to stanchions, struts and other supports for aircraft and other vehicles. More particularly, the invention relates to a composite element for structural applications having an outer shell composed of a metallic or nonmetallic composite skin and a collapsible core material. The composite element is lightweight and has high-energy absorption properties under buckling and impact conditions.
BACKGROUND
Long structural elements such as columns are utilized to vertically support other members such as a floor and must be capable of withstanding compressive, buckling, and impact loads. These structural elements must support the load of the structure it supports and added loads such as vehicles and people.
The load bearing capabilities of these structural elements is determined by the shape of their cross-section, length and material. For lighter weight applications, C or L-channels and hollow structural beams such as round, square or rectangular tubing of aluminum or composite materials are often used. Although strong by design, one disadvantage of these conventional support columns and stanchions is their lower energy absorbing properties during a failure. In crash conditions where the structure may be in compression, composite materials often buckle suddenly and absorb little energy. Failure of these structural elements, known as compressive failure, occurs when the structural elements experience ultimate compressive stresses that are beyond what the material is capable of withstanding. Additionally, buckling failure may result from column instability as a function of the height and width of the structural element.
Composite materials having multiple layered materials are often used in structural applications due to their inherent strength properties. These materials also provide great design flexibility due to the large various material selections and the ability to create various shapes. Structural composite elements often are composed of sandwich-type structure having an outer skin and a filler or core material. The outer skin, or shell, defines the shape and structure of the element whereas the filler material supports the shell.
Various materials are used for both the skin and core of a structural element and are typically chosen based upon the application and environment of use. For example, weight is often a design consideration in aerospace applications. Structural elements such as support beams of wall structures often need to be both lightweight and capable of carrying a mechanical load. In these applications, lightweight metallic skins made of aluminum and nonmetallic skins of thin carbon/epoxy or graphite/epoxy skins are often utilized. Environmental factors such as temperature and corrosive conditions are also considered when selecting skin materials.
The filler material provides both structural support and maintains the shape of the composite element. A variety of filler materials are known and range from the simple, such as balsa wood or other metallic and nonmetallic stiffeners, to complex structures such as aluminum or other nonmetallic honeycomb cores. Core materials are selected based upon their material properties such as flexibility, stiffness and strength-to-weight ratios, energy and sound absorption properties and others.
Environment must also be considered when selecting filling materials. It is not uncommon for carbon/epoxy skinned materials to absorb water, especially in aircraft applications where the structure undergoes pressurizing and depressurizing and are constantly exposed to changing atmospheric conditions. Water trapped in a composite may degrade the filler materials. Water may vaporize in warm conditions and even freeze at low temperatures and high altitudes and when undergoing these phase changes may damage the filler structure especially honeycomb-style core fillers, or disbond the filler from the skin.
Accordingly, there is a need for a lightweight composite structural element that has low structural weight, high structural strength and is capable of absorbing impact or crash energy and stabilizing long-column buckling that does not suffer from the problems and limitations of the prior art.
SUMMARY
The present invention provides a structural composite element that provides the required strength and rigidity for support columns and stanchions and provides inherent energy absorbing properties. This is achieved by the configuration of porous filler material and outer shell. The outer shell may be a metallic material made of aluminum alloys or a composite skin such as carbon/epoxy, fiberglass, metal matrix composite or other suitable composite materials.
A structural composite member constructed in accordance with an embodiment of the invention may comprise a porous core material having high mechanical energy absorption properties in all directions. The porous filler material further allows for the wicking of moisture condensation away from the skin or shell thereby reducing the onset of corrosion and chances of filler material damage.
Another exemplary embodiment of the present invention provides a lightweight structural composite element for long-columns and stanchions that have a high strength-to-weight ratio. An embodiment of the structural composite element also provides increased stiffness with higher energy absorbing characteristics during failure by compression, impact, or buckling than conventional materials.
These and other important aspects of the present invention are described more fully in the detailed description below.
DESCRIPTION OF DRAWINGS
Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein:
FIG. 1 is a fragmentary isometric cut-away view of a structural composite element with a porous filler material constructed in accordance with an embodiment of the invention;
FIG. 2 is a cross-sectional view of the porous filler material of the structural composite element of FIG. 1 ;
FIG. 3 is a fragmentary isometric cut-away view of the structural composite element of FIG. 1 attached to an attachment fitting;
FIG. 4 is a fragmentary side elevation view of the structural composite element with a skin shown in phantom to provide a view of the porous filler material and the attachment fitting of FIG. 3 ; and
FIG. 5 is a fragmentary, cross-sectional side elevation view of the structural composite element and the attachment fitting of FIG. 3 .
The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawing figures are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
DETAILED DESCRIPTION
The following detailed description of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
FIG. 1 illustrates a structural composite element 10 constructed in accordance with an embodiment of the invention and having a skin 12 and an porous filler material 14 . The structural composite element may be used as or incorporated in to a stanchion, strut or other support element of an aircraft, vehicle, or building. In one embodiment, skin 12 may be composed of structural, load bearing materials such as aluminum alloys and other metallic materials such as nickel, Inconel or the like. Alternatively, skin 12 may be composed of a composite such as carbon/epoxy, boron/epoxy, metal matrix composite, or other advanced materials. Carbon/epoxy materials are often advantageous due to the unique structural properties of carbon fiber orientation providing excellent strength properties. The thickness of skin 12 depends upon the material selection and strength criteria. For example, thin skinned components may have skins as thin as a few 0.2 inches or for greater load carrying structures having thickness of 1 to 4 inches.
As shown in FIG. 1 , skin 12 of structural composite element 10 may be formed as a rectangular, hollow beam that encases porous filler material 14 . Porous filler material 14 may be composed of various metallic and nonmetallic filler materials such as porous cores. One embodiment utilizes an aluminum metallic porous filler material such as Duocel® aluminum foam manufactured by ERG Materials and Aerospace, Inc. or alternatively, stabilized aluminum foam, (“SAF”) manufactured by Cymat, Co. of Canada. These porous filler materials of aluminum foam cores provide a metal skeletal structure wherein the foam contains a matrix of cells and ligaments that are regular and uniform throughout the foam. Various densities of foam, number of pores per inch, are available with each density providing different strength characteristics. Alternatively, metallic porous filler material manufactured by Recemat International of the Netherlands may be used. Recemat International produces porous filler manufactured from alternative metallic materials such as copper, nickel, and a corrosion resistant nickel-chromium alloy. Please note that the materials described above are merely examples, and equivalent materials may be produced by other manufacturers not listed herein without departing from the scope of the invention.
These porous filler materials or metallic foam cores provide ease of assembly since they may be cut, milled, ground, lapped, drilled and rolled similar to metal. Likewise, metallic porous filler material may be anodized, coated or metal plated for corrosion resistance. The metallic porous filler material can also be brazed to the skin material or adhesively bonded.
FIG. 2 is a schematic representation of a cross-section of aluminum foam of porous filler material 14 showing open cell 16 and ligament structure 18 . Ligament structure 18 creates multiple supports for skin 12 . As skin 12 deforms under a load or impact, the load or impact energy is transferred to the ligament structure 18 of porous filler material 14 . Under over load conditions or impact, ligament structure 18 fails or crushes resulting in the ligament structure 18 filling open cells 16 . This densification process absorbs energy that would otherwise be redistributed to surrounding structure. The collapsing of the cells 16 of porous filler material 14 absorbs the impact energy and prevents or reduces the rebound of composite structural element 10 after compaction. Unlike conventional honeycomb-style filler materials, porous filler material 14 can absorb energy from impacts or compression in any direction. Similarly, under crash conditions that create compressive forces which typically result in buckling of the structure, ligament structure 18 absorbs the energy by collapsing and thereby stops the transfer of energy along skin 12 and reduces the severity of buckling. This advantage increases the crash worthiness of the structure.
Structural composite element 10 has greater inherent strength provided by porous filler material 14 over hollow beam type structures or those utilizing honeycomb cores. The same or increased strength properties can be realized using lighter weight skins, such as a decreased steel gauge or by material substitution such as aluminum or titanium. Thus, an advantage of the present invention is lighter weight structures having equivalent or increased strength properties.
Another advantage of open cells 16 of porous filler material 14 is that open cells 16 allow any entrapped moisture to wick away from skin 12 , and travel out of the structure. This reduces the risk or effect of environmental corrosion and prolongs the service life of the element.
Porous filler material 14 also may assist in the manufacturing of the structural composite element. When skin 12 is an epoxy matrix material such as carbon/epoxy, porous filler material 14 may be used as the lay-up tool thereby eliminating the need for a mandrel. Metallic porous filler material 14 may be machined to shape and the carbon/epoxy laid on top of porous filler material 14 for a matched fit. Composite skin 12 may be adhesively bonded after cure or alternatively, adhesive may be applied to porous filler material 14 and composite skin 12 lay-up positioned on porous filler material 14 and the materials co-cured.
FIGS. 3-5 illustrate an exemplary embodiment of the structural composite element 10 , wherein at least one end of the porous filer material 14 may be substantially tapered to a point or a rounded-off nub and may connect with an attachment fitting 20 . The attachment fitting 20 may be a clevis fitting as shown, comprising a first flange portion 22 , a second flange portion 24 , and an interface portion 26 connecting the two flange portions 22 , 24 in a substantially U-shaped configuration and interfacing with the composite skin 12 and the porous filler material 14 .
The first and second flange portions 22 , 24 may each have a hole formed therethrough and may be provided with further structural support by at least one brace portion 28 , 30 , connected with at least one of the flange portions 22 , 24 . Additionally, the attachment fitting 20 may comprise a shoulder portion 31 which may be positioned proximate and/or adjacent the brace portions 28 , 30 between the flange portions 22 , 24 and the interface portion 26 . For example, the shoulder portion 31 may have a chamfered face, such as a 45-degree chamfered face, laterally swept around the attachment fitting 20 which may interface with and/or contact an end portion of the composite skin 12 .
The interface portion 26 may be positioned inward of the composite skin 12 and may cover at least a portion of the tapered end of the porous filler material 14 . For example, the interface portion 26 may be shaped to form a cavity 32 at an end opposite the first and second flange portions 22 , 24 , and at least a portion of the tapered end of the porous filler material 14 may be positioned within the cavity 32 .
The interface portion 26 may also have a hole formed therethrough into which a fuse pin 34 may be inserted for connecting the attachment fitting to the composite skin 12 . The fuse pin 34 may be a notched fuse pin or any type of fuse pin known in the art and may be inserted through both the composite skin 12 and the interface portion 26 and secured in place.
The fuse pin 34 may shear off when a predetermined critical load value is applied. Once this happens, the attachment fitting 20 may begin to slide down the structural composite element 10 , compressing it. The porous filler material 14 may stabilize the structural composite element 10 from buckling and crippling. Then the brace portions 28 , 30 and/or the shoulder portion 31 of the attachment fitting 20 may induce a local shear force, pressing into the composite skin 12 and beginning to shred the composite skin 12 as the attachment fitting 20 compresses the structural composite element 10 . For example, the chamfered configuration of the shoulder portion 31 may be operable to force the porous filler material 14 to compress to full densification along the structural composite element 10 .
Although the invention has been described with reference to the embodiments illustrated in the attached drawings, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. | A structural, energy absorbing composite element for aircraft structures includes a metallic or nonmetallic skin shell with a porous filler material insert positioned within the skin shell. The porous filler material is a material having ligaments that collapse resulting in a densification of the porous filler material in response to impact loading or a compression force sufficient to cause failure of the combined assembly. | 8 |
FIELD OF THE INVENTION
The invention relates to an industrial shock absorber with a tube-shaped body and a damper piston which is longitudinally displaceable and sealingly arranged therein.
BACKGROUND OF THE INVENTION
German Patent Publication DE 33 24 165 C2 relates to a hydraulic shock absorber with two operative ends, having a pressure tube, arranged in a housing and filled with hydraulic fluid, and several fixedly set or adjustable throttle openings, which are distributed over the length of the pressure tube and are connected on one side to a pressure chamber of the pressure tube and on the other side to hollow chambers of the housing, and having piston rod seals on the ends, wherein respectively one piston is associated with the common pressure chamber of the pressure tube. The cup-shaped piston is connected in one piece with the pressure tube. The second piston moves over the throttle bores, which results in a damping effect.
The disadvantage of this construction lies in the active piston surface, which is relatively small in relation to the exterior diameter. For this reason the throttle bores must be made very narrow, which causes problems in connection with their manufacture. In addition, dirt in the damping fluid can lead to closure of the throttle bores.
International application WO 94/17317 (PCT/DE93/01260) and German Utility Model G 93 02 454.1 also relate to a hydraulic shock absorber, wherein an axially helically extending damping groove is arranged on the piston jacket of the damping piston, wherein a coaxial, endlessly extending oil outflow groove is arranged on the interior jacket face of the oil and piston chamber, which groove is completely covered by the piston in the initial position of the piston. This shock absorber has a gas pressure reservoir and rubber cuffs as the equalizer for the amount of oil. Hydraulic shock absorbers of this type are provided with a cylinder housing with a piston and with an oil outflow regulator, which regulates the oil flow from the oil and piston chamber and causes a reduction of kinetic energy acting on the piston, and with an oil outflow valve and a spring force, which pushes the piston back into its initial position. The damping groove, which extends axially on the circumferential jacket of the piston, terminates at the front face of the piston, wherein a coaxial, endlessly extending oil outflow groove is provided on the interior jacket face of the oil and piston chamber, which in the initial position of the piston is completely covered by the piston. Two damping grooves, offset by 180.o slashed. in respect to each other, extending axially and having oil flow cross sections which are different from each other, are disposed on the circumferential jacket of the piston. The exterior circumferential rim of both the front face of the piston and the piston bottom is interrupted by the damping groove terminating in the front face of the piston and the piston bottom. This known shock absorber is furthermore said to be distinguished in that one of the damping grooves is provided with a cross section which in particular narrows continuously from the front face of the piston to the piston bottom, while the other damping groove is provided with a cross section which remains the same over its entire length and is of the same depth. The cross section of the continuously narrowing damping groove is embodied as a section of a circle. An adjustable regulating valve, which is in direct engagement with the damping groove, is provided in one damping groove for regulating the oil flow. It is furthermore proposed to provide a slider, which can be adjusted perpendicularly in respect to the damping groove, with a one-sidedly coaxial slider tip, whose axial longitudinal section corresponds to the cross section of the damping groove, wherein the slider tip can be interlockingly screwed into the damping groove. The slider should be disposed, radially and axially adjustable, directly in the cylinder housing. The slider is sealed against the housing, in particular by an O-ring. The oil outflow groove is provided with a rectangular cross section. At least one oil outflow groove is provided on the interior jacket face of the oil and piston chamber directly adjacent to the piston, which terminates on the one side in the oil outflow groove and on the other side extends past the piston when it is in its initial position. Two oil outflow grooves, which are located opposite each other and extend axially, are disposed on the interior jacket face of the oil and piston chamber. These oil outflow grooves are provided with a round cross section of little radial depth. An oil reservoir formed by a body-elastic rubber cuff is provided spatially axially behind the oil and piston chamber. The rubber cuff is a coaxial symmetrical shaped body which is respectively provided with coaxial circular flanges in the area of its two front faces. With the two flanges the rubber cuff is in engagement with a groove in a bearing sleeve. A coaxially extending gas chamber is formed between the rubber cuff and the bearing sleeve. The housing on the side of the piston rod is provided with two coaxial seals located one behind the other. The seals are formed of a sealing medium support with an O-ring, which seals coaxially toward the adjoining interior housing jacket and with a seal ring, which seals coaxially toward the piston rod. A venting groove is formed between the two sealing medium supports, wherein a venting bore is provided in the wall of the housing adjacent to the venting groove. For forming an oil gap, the piston is seated, axially displaceable to some extent, on the piston rod, in particular on a pin connected in one piece with the piston rod. A sealing disk is disposed coaxially and seated between the piston bottom of the piston and the one front face of the bearing sleeve. The outer jacket face of the sealing disk is smaller by an oil gap than the diameter of the adjoining interior jacket face of the oil and piston chamber. A spring force, seated and acting in the oil and piston chamber, is provided for returning the piston into its initial position. The housing is provided with a screw thread extending in particular over the entire outer cylindrical length. A one-sided, coaxially extending cylindrical bolt for placing a seal ring is disposed on the exterior circumference of the housing in the area of the outlet of the piston rod. Two surfaces, located opposite each other, for applying a mounting tool are disposed on the exterior circumference of the housing, in particular in the area of the housing end located opposite the exit of the piston rod.
Hydraulic shock absorbers of the previously described type are constructed extraordinarily elaborate and consist of many single parts, so that the production costs are correspondingly high. The ability to reproduce the damping behavior is reduced in particular when employing a helical groove. The rubber cuff is difficult to mount, since initially its ends have to be sufficiently stretched so that it can be passed over elements of considerably larger cross section. Afterward it must be glued in properly, which is also connected with difficulties because of the special construction. Thus the production as a whole is hard to control. Since the calculation and production of the helical groove in the production piston is connected with a relatively high outlay, the exact capability of reproducing damping curves can only be partially realized. In case of warming of the oil after several hours of operation the flow-through behavior of the hydraulic fluid in the helical groove changes and with it the characteristic curve of the entire shock absorber.
European published, non-examined patent application EP 0 386 433 (90101539.6) relates to a hydraulic shock absorber with a housing embodied particularly as a cylinder, in which a high pressure chamber filled with a hydraulic medium is disposed, which can be charged by a piston which is displaceable in a housing by means of a mass movement to be damped and displaces hydraulic medium out of the high pressure chamber in the course of its damping movement, wherein a damping device is provided, which operates pressure-dependently under the influence of the pressure prevailing in the high pressure chamber in order to regulate the displacement flow. In addition to the first damping device, which operates in a pressure-dependent manner, a second damping device, which operates in a path-dependent manner under the influence of the displacement path of the piston, is provided for regulating the displacement flow. The shock absorber has a spring-loaded intermediate piston with a double seal as the oil equalizing reservoir and a throttle needle, which plunges into a conical bore. An overpressure valve is additionally represented on the damping piston.
The double seal is disadvantageous, since it must seal on the inside as well as the outside. Furthermore, the fact of a plurality of individual parts should be stressed as being disadvantageous.
German patent publication DE 33 02 790 C2 relates to a shock absorber with a hydraulic cylinder, in whose interior an adjustment piston is disposed, which is displaceable in the axial direction and separates a high pressure chamber filled with a hydraulic fluid from a low pressure chamber, and is in connection with a piston rod which extends in the axial direction, crosses one of the chambers while reducing its fill cross section and sealingly penetrates the associated cylinder front face toward the exterior. The two pressure chambers of different fill cross section are connected on the one hand by means of an interposed spring-loaded overflow valve, which is fixed on the housing in the interior of the cylinder and whose closing force can be regulated and which opens when the high pressure chamber is compressed, and on the other hand by means of a flap valve formed in the adjustment piston and arranged parallel with the overflow valve. The low pressure chamber communicates with an equalization chamber for the hydraulic fluid. A second low pressure chamber, located on the axial side of the high pressure chamber opposite the first low pressure chamber and communicating with the first low pressure chamber via a flow conduit extending mainly in the axial direction, is interposed in the connection between the overflow valve and the first low pressure chamber which is crossed by the piston rod. The overflow valve is located in the space between the high pressure chamber and the second low pressure chamber and essentially follows the high pressure chamber directly, wherein the equalization chamber is formed by one of the low pressure chambers and is always completely filled and acted upon by a spring-loaded work piston.
The structural length, the multitude of individual parts and in particular the multitude of sealing elements and, because of this, an expensive production, are disadvantageous in this design.
International application WO 86/00675 (PCT/GB85/00298) also relates to a shock absorber, wherein a pressure control valve is provided in place of throttle bores. However, pressure control valves in shock absorbers have been shown to be trouble-prone and as a rule react too slowly. It is not possible to control different damping curves with them.
European patent publication EP 0 436 461 B1 relates to a hydraulic shock absorber for the industry, which has a piston rod on which a throttle orifice is disposed and cooperates with a throttle needle with a stepped cross section which increases from the free tip to the cylindrical, attachable part. Over its entire length with which it cooperates with the throttle orifice, the throttle needle is designed conically, wherein the conicity decreases, starting at the tip. This model operates with a diaphragm pressure reservoir as the oil equalizer and with a conically stepped throttle needle. This embodiment also has a great structural length in relation to the stroke. It is difficult to maintain the throttle needle exactly in the center. When the oil warms, the damping behavior fluctuates more strongly than with covered throttle bores.
OBJECT AND SUMMARY OF THE INVENTION
The invention is based on the object of providing an industrial shock absorber operating by means of a liquid damping medium, which permits a simple capability of reproducing different damping curves over a large temperature range while the damping piston has a relatively large diameter in respect to the exterior diameter and is structurally simply designed.
An industrial shock absorber in accordance with the invention can be manufactured from relatively few component parts--simply and cost-effectively. For example, the housing can be mass-produced and can have two bores for a stud driver on the bottom, for example. The piston rod can also be mass-produced and have a groove and a shoulder which is turned on a lathe. Furthermore, the cup-shaped piston is mass-produced and provided with throttle bores and a flap valve bore. The bearing can also be mass-produced and can be glued in, for example, during assembly. Also, a rolled diaphragm or a ring holding a pressure reservoir made of a closed-cell elastomer can be mass-produced and merely needs to be provided with one or several bores. If a rolled diaphragm is provided, it is used as a seal, as a volume equalizer for the piston rod and a restoring spring.
With embodiments having a pressure reservoir or an absorber consisting of a closed-pore elastomer, the latter is used as volume equalizer when the piston rod is retracted.
The invention is represented in the drawings, partially schematically, by means of two exemplary embodiments in longitudinal section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents an industrial shock absorber with a roller diaphragm,
FIG. 2 represents a similarly constructed industrial shock absorber with an elastomer pressure reservoir.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A tube-shaped housing, made of one-piece from steel, is identified by the reference numeral 1 and is produced, for example, by drilling a rod open and is therefore particularly tight and pressure-resistant. The housing 1 is embodied to be open on one side only. A bearing bush 2 is disposed in the open mouth, for example glued in, screwed in or fastened in some other way tightly, but releasably, in the housing 1. The bearing bush 2 is sealed toward the exterior. This is accomplished in the embodiment in accordance with FIG. 1 by a means of a rolled diaphragm 3, and in the embodiment in accordance with FIG. 2 by means of a seal 4 disposed in a grooved recess of the bearing bush 2. If required, the seal 4 can also be multiply disposed, in particular it can act sealingly toward both sides. In the embodiment in accordance with FIG. 2, a seal 5 is furthermore disposed in an annular groove.
It can be seen that the bearing bush 2 extends past the outside-facing annular front face 6 by means of a collar 7 of increased diameter. This collar 7 has an annular face extending plan-parallel with the annular front face 6, so that with its collar 7 the bearing bush 2 rests flat on the annular front face 6.
A piston rod 8 is disposed longitudinally displaceable in the bearing bush 2 in a bore 10 extending coaxially with the longitudinal center axis 9.
In the represented embodiments, the exterior jacket face 11 of the housing 1 is embodied with the same diameter and can be shaped cylindrically. It can furthermore be seen in FIGS. 1 and 2 that on the end section facing away from the piston rod 8 the represented embodiments are provided with an exterior thread for fastening the industrial shock absorbers on a device, not shown, for example on a manipulating device, in a machine tool or the like.
On the front end which is embodied closed, both embodiments have two blind bores 12 or 13, which are disposed mirror-reversed in respect to the longitudinal center axis 9 and into which a tool, not shown, can be inserted.
In its interior the housing 1 consists of a total of three successive housing segments 14, 15 and 16 delimited by cylindrical jacket faces. With the represented embodiments the arrangement has been made such that the respectively succeeding housing segment is of a reduced diameter. This means that the housing segment 14 has the largest interior diameter, the succeeding housing segment 15 a somewhat smaller diameter and the housing segment 16 has the smallest diameter. The housing segments 14, 15 and 16 are embodied to be continuously cylindrical over their respective lengths A, B or C. Furthermore, all housing segments 14, 15 and 16 are arranged coaxially with each other, so that the housing 1 has a cartridge-shaped exterior.
Because of the division of the housing 1 into the three housing segments 14, 15 and 16 with respectively different interior diameters, an inward-projecting, relatively sharp-edged annular shoulder 17 or 18 results respectively at the transition to the succeeding housing segment, i.e. from 14 to 15 and from the housing segment 15 to 16.
As can be seen from the drawings, the longitudinal section facing the closed front end of the housing 1 of a cup-shaped damping piston 19 is led as pressure medium-tight as possible, except for minor leaks, along the interior wall of the housing section 16. To this end the exterior jacket face 20 of the damping piston 19 is matched to the interior jacket face of the housing section 16. If the interior jacket face of the housing segment 16 is cylindrical, except for minor leaks, the exterior jacket face 20 is also embodied cylindrical.
In all embodiments the damping piston 19 is embodied tube-shaped and open at its front end facing the closed end section of the housing 1, and the damping piston 19 is conically widened toward the outside on a longitudinal segment D.
The damping piston 19 is provided on its interior with a cylindrical interior jacket face 21 which extends over approximately 80% of the total length of the piston. The material of the tube-shaped portion of the damping piston 19 is connected by means of a piston bottom 22 in one piece with the tube-shaped longitudinal section of the damping piston 19. In this area the damping piston 19 has an annular shoulder 23 overlapping the exterior jacket face 20, by means of which the damping piston 19 is seated and guided longitudinally displaceable on the interior jacket face of the housing segment 15. The annular shoulder 23 can be provided with several bar-shaped openings or, as represented, with at least one, preferably several connecting bores 24 distributed over the circumference and extending parallel with the longitudinal center axis 9.
An annular space 25, which is connected via the openings or connecting bores 24 or the like with an equalization chamber in a fluid-conducting manner, is disposed between the exterior jacket face 20 of the damping piston 19 and the interior jacket face of the housing segment 15.
In the embodiment in accordance with FIG. 1, the rolled diaphragm 3 is disposed in this equalization chamber 26 and is connected, sealed against pressure medium, with its one end over a bead 28 with an annular groove 27 of the piston rod 8. At its other end the rolled diaphragm 3 is connected, also over a bead 29, with an annular groove of a ring 30, through the center of which the piston rod 8 penetrates. The ring 30 is sealed against fluid by means of a seal 31 on the interior wall of the housing segment 14. The beads 28, 29 are also embodied to be sealed against fluid.
At least one conduit 32, whose longitudinal axis extends parallel with the longitudinal center axis 9, is provided in the ring 30. The conduit 32 connects the equalization chamber 26 via the connecting bore 24 or the like with the annular chamber 25 in a manner yet to be described.
A further through-bore 33 is additionally provided in the piston bottom 22, which connects a damping chamber 34 in a manner yet to be described via the conduit 32 also with the equalization chamber 26.
A pin 35 with a reduced diameter is connected as one piece with the piston rod 8 which has an annular shoulder 36 on its free end, wherein a detent, for example a snap ring 37, is releasably disposed on the pin 35. As can be seen from FIG. 1, in the initial position shown some play is provided between the interior 38 of the piston bottom 22 and the detent 37. The pin 35 need not be disposed sealed against fluid in the bore of the piston bottom 22 receiving it. However, the pin 35 is disposed longitudinally displaceable in the through-bore of the piston bottom 22 by an amount which is axially limited by the annual shoulder 36 of the piston rod 8 on the one side and the detent 37 on the other.
It can furthermore be seen in FIG. 1 that on its one side the damping piston 19 has several throttle bores 39, which are disposed parallel with each other and connect the damping chamber 34 with the annular chamber 25. During an axial displacement, i.e. during a damping process, these throttle bores 39 are covered one after the other by the relatively sharp-edged annular shoulder 18 and sealed, so that in the course of the damping piston 19 plunging into the damping chamber 34 less and less throttle bores 39 are available for the flow-off of the throttle fluid into the annular chamber 25 and therefore via the connecting bore 24 and the conduit 32 into the equalization chamber 26.
In the course of the damping piston 19 plunging in, i.e. during the damping process, the plan-parallel front of the damping piston 19 which extends orthogonally with the longitudinal center axis 9 and faces the ring 30 is lifted off the plan-parallel II front face of the ring 30, which is embodied in the same way, so that damping fluid can exit through the throttle bore 39 into the annular chamber 35, the connecting bore 24 and the conduit 32 into the equalization chamber 26, wherein the rolled diaphragm 3 is placed under spring-elastic tension so that later on during the return of the shock absorber into its initial position it assists by acting in the manner of a spring element.
In this case the through-bore 33 is covered by the annular shoulder 36 of the piston rod 8. This annular shoulder extends orthogonally with the longitudinal axis 9, the same as the front face of the piston bottom 22 facing the piston rod 8. Both the front faces of the annular shoulder 36 of the piston rod 8 and of the piston bottom 22 are embodied plan-parallel and rest sealingly on each other until the damping piston 19 is lifted off the annular shoulder 36 of the piston rod 8.
In the embodiment shown in FIG. 1, the bearing bush 2 has a relatively long cylindrical section on its outer jacket face, which fittingly engages the housing segment 14 and rests against it interior wall.
To form the equalization chamber 26, the bearing bush 2 has a longitudinal section L, whose wall is delimited inside and outside by cylindrical walls and has a relatively thin wall thickness. Thus the bearing bush 2 is embodied to be tube-shaped over the longitudinal section L. A longitudinal section K adjoins the longitudinal section L and is composed of the collar 7 and a longitudinal section with an increased wall thickness. This last longitudinal section has a conically tapering longitudinal section M and a cylindrical longitudinal section V. The bead 28 and a portion of the rolled diaphragm 3 are disposed in the latter, while the rolled diaphragm 3 is spring-elastically deformed into the longitudinal section M and in the longitudinal section L during the damping process. The transition between the longitudinal section L and the longitudinal section M can take place via a radius in order to protect the rolled diaphragm 3.
If an impulse is directed on the piston rod 8 and/or the housing 1, these elements are pushed together in a telescoping manner, wherein the damping piston 19 plunges into the damping chamber 34, and its throttle bores 39 are sealed one after the other by the interior wall of the housing section 16 as fluid-tightly as possible.
Following the braking of the mass, the rolled diaphragm 3, which is under tension and which can be made of an elastomer, causes the return of the telescoped parts. In this case the annular shoulder 36 of the piston rod 8 is lifted off the front face of the piston bottom 22, so that the through-bore 33 is also opened. The displacement of the piston rod 8 in respect to the damping piston 19 lasts until the detent 37 touches the interior front face 38 of the damping piston 19. Therefore the annular shoulder 36 of the piston rod 8 and the through-bore 33 constitute a flap valve. In this way it is possible for the fluid stored in the equalization chamber 26 to flow through the conduit 32 and through the through-bore 33 back into the damping chamber 34. A part of the damping fluid also enters the damping chamber 34 through the connection bore 24 or the like and the throttle bores 39 until the industrial shock absorber has reached its initial position visible in FIG. 1.
Not only the housing 1, the bearing bush 2, the piston rod 8, the ring 30 and the damping piston 19 can be made of metallic materials, for example steel, but also the detent 37.
The seals and the rolled diaphragm 3 are respectively made of aging-resistant, ozone-resistant, non-fading elastomers which are resistant to the damping fluids used, for example of polyurethane caoutchouc with spring-elastic properties.
In the embodiment according to FIG. 2, the bearing bush 2 is embodied in the approximate shape of a double T, as can be seen from the axial longitudinal section visible in the drawings, wherein the one bar of the double T is made in one piece of the same material with the collar 7, while the other bar of the double T is disposed at an axial distance from the collar 7 and is embodied as an annular bearing flange 40. This annular bearing flange 40 is seated on the annular shoulder 17. Otherwise the exterior jacket surface of the annular bearing flange is also cylindrically designed and fits snugly into the longitudinal segment 14 and rests flat against the interior jacket face of the housing segment 14.
The equalization chamber 26 is created between the annular shoulder 17 and the annular bearing flange 40 in which, the equalization or receiver element 41, made of an elastic elastomer plastic material, is disposed. The receiver or equalization element 41 is embodied as a closed-pore sponge and is used to equalize the volume of the retracted piston rod.
A conduit which has the same function as the conduit 32 in the embodiment of FIG. 1 is identified by 42. The piston rod 8 is arranged in a depression 43 on the end front face. To this end the piston rod 8 has a shoulder 44 of increased diameter which partially projects out of the depression 43 in the axial direction toward the damping piston 10. The depression 43 is disposed coaxially in respect to the longitudinal center axis 9.
A through-bore 45 is provided in the piston bottom 22, which has the same purpose as the through-bore 33. Furthermore, a valve seat 46 is provided in the piston bottom 22, to which a blocking body 47 is assigned, which in this case is embodied as a ball. So that this ball 47 cannot fall out of the valve chamber 48 formed in the piston bottom 22, the rim areas 49 facing the damping chamber 34 are flanged by chiseling or the like, but without closing the flow cross section.
A compression spring, only schematically indicated, is identified by 50, which is supported under pre-stress at its one end on the closed bottom of the housing 1 and with the other end on the piston bottom 22. The compression spring 50 is seated and guided by the cylindrical portion of the damping piston 19. The compression spring 50 is used to push the damping piston 19 and the piston rod 8 into the indicated initial position.
The mode of functioning of the embodiment represented, an equalization or receiver element 41, made of an elastic elastomer plastic material, is disposed. The receiver or equalization element 41 is embodied as a closed-pore sponge and is used to equalize the volume of the retracted piston rod.
A conduit which has the same function as the conduit 32 in the embodiment of FIG. 1 is identified by 42. The piston rod 8 is arranged in a depression 43 on the end front face. To this end the piston rod 8 has a shoulder 44 of increased diameter which partially projects out of the depression 43 in the axial direction away from the damping piston 10. The depression 43 is disposed coaxially in respect to the longitudinal center axis 9.
A through-bore 45 is provided in the piston bottom 22, which has the same purpose as the through-bore 33. Furthermore, a valve seat 46 is provided in the piston bottom 22, to which a blocking body 47 is assigned, which in this case is embodied as a ball. So that this ball 47 cannot fall out of the valve chamber 48 formed in the piston bottom 22, the rim areas 49 facing the damping chamber 34 are flanged by chiseling or the like, but without closing the flow cross section.
A compression spring, only schematically indicated, is identified by 50, which is supported under pre-stress at its one end on the closed bottom of the housing 1 and with the other end on the piston bottom 22. The compression spring 50 is seated and guided by the cylindrical portion of the damping piston 19. The compression spring 50 is used to push the damping piston 19 and the piston rod 8 into the indicated initial position.
The mode of functioning of the throttle bores 39 is the same as described in connection with FIG. 1.
At least two bores or conduits 51 and 52, which intersect at right angles and are approximately semicircular, are disposed on the end section facing the piston rod 8, so that damping fluid can flow out of the equalization chamber 26 via the flap valve, i.e. past the blocking body 47, into the damping chamber 34 when the telescoping elements are retracted.
In this embodiment, too, the housing 1, the seating bush 2, the piston rod 8, the damping piston 19 and the blocking body 47 are made of a metallic material, in particular steel.
It can be seen by means of a comparison between WO 94/17317 and the embodiments represented in FIGS. 1 and 2 how few component parts are needed for an industrial shock absorber in accordance with the invention and how simple the structure of these embodiments in accordance with the invention is:
______________________________________For comparison WO 94/17317 Invention______________________________________Total component parts 14 8 or 9Standard or purchased parts 4 2 or 3Parts to be manufactured 10 6______________________________________
The features described in the specification, the claims and the abstract and which can be taken from from the drawings can be important for realizing the invention individually as well as in any arbitrary combination. | The invention relates to an industrial shock absorber requiring very few component parts, which can be cost-effectively produced while expensive milling operations are avoided, wherein different damping curves can be realized relatively simply. The shock absorber has good temperature stability in the cold and warm states, wherein the largest possible piston diameter can be achieved because of the special construction in accordance with the invention, which further contributes to stability and safety. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED
[0002] Not Applicable
RESEARCH OR DEVELOPMENT
[0003] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER
[0004] Not Applicable
PROGRAM LISTING COMPACT DISC APPENDIX
[0005] Not Applicable
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Invention
[0007] This invention relates to a device for illuminating objects being viewed by a camera. More particularly, this invention relates to an illumination frame for a webcam that illuminates a person or object viewed using a communications device such as a webcam.
[0008] 2. Description of Related Art
[0009] Video conference calls are a common method for people to communicate when the parties are remote and wish to be simultaneously viewed. Online viewing via the internet has grown increasingly popular for social purposes as well. This images and video are commonly acquired through a small video camera on a communications device. Communications devices include desktop computers, laptops, tablets, smartphones, cellular phones, flat screens, televisions and other devices that includes a still or video camera for capturing images to be shared.
[0010] It is desirable to appear as attractive and appealing as possible in the images obtained via communications devices. For example, in online chatting or dating sites, a user desires to appear as attractive as possible. However, because these cameras and communications devices are usually not located in a photography studio or other ideal environment, images are not always their clearest and most appealing.
[0011] Poor lighting is one of the primary reasons for the poor appearance of images that are viewed from webcams on communications devices. The image is not as accurate and the individual does not appear as attractive as they otherwise would in person. Proper lighting ensures an aesthetically pleasing appearance of an individual's face.
[0012] Those skilled in the art of the motion picture and/or photography industries will appreciate that lighting of an object or person being viewed may be difficult and have developed complex methods of illuminating their subject matter. However, such elaborate lighting fixtures are impractical for use with a webcam on a communications device. Using a simple bright light may be uncomfortable for the person being viewed.
[0013] Accordingly, there is a need to provide proper lighting for users that are viewed through a webcam to ensure that they appear aesthetically pleasing. It is therefore desirable to provide a system and method for applying light to an object or person being viewed that effectively improves its appearance without be uncomfortable.
SUMMARY OF THE INVENTION
[0014] The present invention provides an illumination frame comprising an elongate base having a plurality of lights, a first end, and a second end, a first arm having a plurality of lights and a tension clip, the first arm being pivotally attached to the first end of the base and a second arm having a plurality of lights and a tension clip, the second arm being pivotally attached to the second end of the base.
[0015] The present invention further provides an illumination frame wherein the lights include a diffusing lens.
[0016] The present invention further provides a method of illuminating an object being observed through a camera proximal to a monitor comprising arranging about the monitor a frame comprising a base, a first arm and a second arm, wherein each of the base, first arm and second arm have a linear light array.
[0017] Accordingly, an object of the present invention is to provide a system and means for illuminating an object or person being viewed by a camera, and specifically a webcam. It is another object of the present invention to provide a system and means to improve the aesthetic quality of a person or object being viewed by a webcam.
[0018] It is a further object of the present invention to provide a system and means of illuminating a person in front of a webcam without causing discomfort.
[0019] These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of an embodiment of the illumination frame and a tablet;
[0021] FIG. 2 is a front view of another embodiment of the illumination frame;
[0022] FIG. 3 is a front view of the illumination frame of FIG. 2 attached to a tablet;
[0023] FIG. 4 . is a perspective view of the illumination frame of FIGS. 2 and 3 attached to a laptop monitor;
[0024] FIG. 5 is a front view of the illumination device of FIGS. 2 , 3 and 4 collapsed to a storage configuration;
[0025] FIG. 6 is a front view of an alternative embodiment of the illumination frame;
[0026] FIG. 7 is a front view of the illumination frame of FIG. 6 attached to a computer monitor.
DETAILED DESCRIPTION
[0027] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0028] FIG. 1 . shows an illumination frame 10 for use with, e.g., a tablet internet device 12 . The frame 10 may be comprise of four rectilinear light arrays 18 . The frame 10 may be substantially rectangular and made of a material, such as for example metal, plastic or a lightweight composite, that may be optionally rigid, semi-rigid or flexible. The frame 10 may be removably attachable to the outside edges 14 of the tablet 12 . The frame 10 may include one or more clips 16 for removable attachment to the outside edges 14 of the tablet 12 . Optionally, clips 16 may be tension clips, clamps or similar devices that may allow removable attachment to the tablet. Optionally, the frame may be attachable to the tablet by adhesives.
[0029] One of the light arrays 18 may include an aperture 20 aligned with the position of a webcam 22 on the tablet 12 . In this embodiment, each of the light arrays 18 has a substantially linear arrangement of individual lights 24 . The individual lights 24 of the light arrays 18 may be LED lights, incandescent bulbs or other devices for emanating light. Optionally, the lights may be configured in a nonlinear pattern along the arrays 18 , such as for example a zig-zag pattern or in a series of light clusters. Optionally, each of the arrays 18 may be a single elongate light source rather than a series of individual lights. Preferably the light arrays 18 provide illumination to an object in front of the webcam 22 from a plurality of angles, thereby minimizing shadows on the object viewed and otherwise enhancing the view of the webcam 22 .
[0030] The lights 24 optionally include one or more diffusing lenses to soften the light they emit. By using a plurality of relatively soft lights 24 , a person or animal being viewed by the webcam 22 may not experience the discomfort associated with exposure to high intensity light.
[0031] The frame may be include batteries to supply power to the lights. Optionally, the frame may include a power cord 26 . The power cord 26 may be adapted to connect to an A.C. power source such as a wall socket or may optionally connect to a USB port of the tablet. This embodiment includes a plug 29 for connection to a standard wall socket.
[0032] The lights of the frame 10 may be controlled by a simple on/off switch 28 on the power cord 26 or on the frame 10 . Alternatively, the intensity of the light emitted by the arrays 18 may be attenuated by an adjustable switch. If the frame is powered by a cord connected to a USB port of the tablet, the intensity of emitted light may be adjusted by software that attenuates the power supplied to the lights. Software may also optionally actuate the light arrays semi-automatically, for example only actuating the lights when the webcam is in use. It may be desirable to provide software or other light controlling means to allow the lights to alter the color of the emitted light, or to blink in various patterns.
[0033] FIG. 1 shows the illumination device used with a webcam on a tablet type internet device. However, the device may be used with any communications device, loosely defined as any device used to capture video or still images that may or may not include instantaneous access to the internet or other communication medium and may include, but is not limited to, desktop computers, laptop computer, tablets, smartphones, cell phones, televisions, flat screen televisions, monitors and other devices that may incorporate a video or still image capturing camera.
[0034] FIG. 2 shows an illumination frame 40 having three adjustable arrays. The primary array 42 has two distal pivot points 44 . Side arrays 46 are attached to the primary array 42 at the pivot 44 points and may be adjustably pivoted in relation to the primary array 42 .
[0035] The illumination frame 40 , as with the illumination frame 10 of FIG. 1 , may be made of various and sundry materials, such as for example metal, plastic or a lightweight composite, that may be optionally rigid, semi-rigid or flexible. The side arrays 46 may include one or more clips 48 which may be tension clips, clamps or similar devices that may allow removable attachment to a tablet, computer monitor or other device having a camera. Optionally, the frame 40 may be attachable by adhesives. The lights 50 of frame 40 may include diffusing lenses and the arrays may be arranged linearly or in different patterns. In this embodiment, the lights 50 are arranged in an incongruent manner along the primary array 42 and each of arrays 46 . The lights 50 of the frame 40 may be controlled by a simple switch or by software, as explained supra.
[0036] FIG. 3 . shows the illumination frame 40 of FIG. 2 attached to a tablet internet device 54 . Because the side arrays 46 are adjustably pivotable in relation to the primary array 42 , the frame 40 may be adjusted to accommodate and attach to tablets of varying size. In FIG. 3 the width of the tablet 54 is less than the length of the primary array 42 . The side arms 46 are pivotably adjusted such that the frame 40 lies flush with three of the four edges of the tablet 54 and clips 48 attach the illumination frame 40 to the tablet 54 .
[0037] FIG. 4 shows the illumination frame 40 attached to a monitor 58 of a laptop 60 . The width of the laptop 60 is different than the width of the tablet 54 . The illumination frame 40 may be adjusted to suit either device.
[0038] FIG. 5 shows the illumination frame 40 collapsed for easy storage or transport. The side arrays 46 may be pivoted such that they are parallel to and flush with the primary array 42 , forming a compact configuration.
[0039] FIG. 6 shows an illumination frame 70 having a primary array 72 that may be adjusted to alter its length. The primary frame 72 has two slidably engaged and partially overlapping sections 74 and 76 . These sections may be slidably adjusted to alter the length of the primary array. The side arrays 78 may extend from the primary array 72 . The side arrays 78 may be pivotably attached to the ends of the primary array 72 to allow adjustment as shown in FIGS. 2-5 . Optionally, the side arrays 78 may extend from the primary array 72 perpendicularly without the ability to pivot, as the illumination frame shown in FIG. 1 . The illumination frame 70 may optionally include a fourth array extendable between the distal ends of the side arrays. Slidable adjustment of may be facilitated by any of the methods known in the art for sliding two straight objects, such as for example the sliding mechanisms of a slide-rule calculator or a telescope.
[0040] FIG. 7 shows an illumination frame 82 attached to a computer monitor 83 . Illumination frame 82 has a primary array 84 comprised of two slidably adjustable portions 86 and 88 and sliding-engagement point 90 . The illumination frame 82 has two side arrays 92 perpendicular to the primary array 84 . The illumination frame 82 also includes a lower array 94 comprised of two slidably adjustable portions 96 and 98 that connect at sliding-engagement point 100 .
[0041] Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. Descriptions of the embodiments shown in the drawings should not be construed as limiting or defining the ordinary and plain meanings of the terms of the claims unless such is explicitly indicated. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. | An illumination frame attaches to a laptop computer, computer notebook, table or other communications device having a camera. The frame has a series of light arrays that illuminate an object placed before the camera so that it is more easily and clearly viewed. The arrays provide lighting from many different angles. The lights include diffuse lenses to soften the light applied of an object being viewed. | 5 |
[0001] The present patent application is a division of U.S. patent application Ser. No. 12/994,403, which is a national stage application under 35 U.S.C. §371 of PCT/US2009/003486, filed Jun. 10, 2009, which claims the priority of U.S. Patent Application No. 61/060,196 which was filed on Jun. 10, 2008 and which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention describes a novel process for the conformal coating of polymer fibers on nonwoven substrates. Specifically, the process is based on the modification of polymer fiber surfaces by controlling the degree of etching and oxidation, which improves adhesion of initiators to the surface and facilitates subsequent conformal polymer grafting. The invention further includes the nonwoven substrates produced by this process.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 5,871,823 [Anders, Hoecker, Klee, and Lorenz] [1] reports using UV light in the wavelength range of 125-310 nm to activate polymer surfaces in the presence of oxygen with a partial pressure of 2×10 −5 to 2×10 −2 bar. The activated surface is subsequently grafted. However, this patent is limited to the use of surface hydroperoxides obtained from UV activation to initialize grafting.
[0004] U.S. Pat. No. 5,629,084 (Moya, Wilson) [4] discloses a composite porous membrane formed from a porous polymeric substrate and a second polymer which has been cross-linked by heat and UV. The modification of the second polymer is over the entire surface, which is attained by placing a membrane in contact with a second polymer solution and initiator and exposing everything to UV or mild heat in order to crosslink a second polymer on the substrate surface. This scheme can be categorized as a “grafting to” technique where the adsorption of a second polymer to the fiber surface is the critical step.
[0005] UV-initialized grafting is generally performed by exposing the substrate to UV light in monomer solutions. It can take place in the range 100-450 nm for a variety of molecules. U.S. Pat. No. 5,871,823 [Anders, Hoecker, Klee, and Lorenz] [1] reported using a preferred UV wavelength in the range 290-320 nm. PCT/WO/02/28947 A1 [Belfort, Crivello and Pieracci] [5] reported using UV wavelengths in the range 280-300 nm. These inventions do not refer to the use of a photosensitizer in the grafting process.
[0006] In addition, U.S. Pat. No. 5,468,390 [Crivello, Belfort, Yamagishi] [6] discloses a process to modify polysulfone porous membranes without photosensitizers. As a result, only the outer surface of the membranes described in this reference was modified through the treatment. The polysulfone membranes cannot be rewetted after drying.
[0007] U.S. Pat. No. 5,883,150 [Charkaudian] [7] reports that implanting a photosensitizer into the backbone of the polysulfone membrane results in better wetting properties. Nonetheless, it is difficult for most of these implanted photosensitizers to survive the high temperature conditions that are generally used for polymer processing. For example, fiber or nonwoven production with melt-blowing processes requires temperatures above 120° C.
[0008] In summary, while surface modification methods such as those described above may generate some coatings on the fiber surface of fiber nonwoven webs or mats, a conformal coating cannot be assured by these methods because they do not provide the necessary means either to overcome possible differences between the surface energies of the substrate and second polymers, or to generate a surface with a high density initiator.
[0009] It is, therefore, desired to have a surface modification method which can warrant conformal coating for a wide range of polymer fibers. It is also desired that this method be robust and easy to scale-up. The present invention seeks to meet these and related needs.
SUMMARY OF THE INVENTION
[0010] This invention describes a procedure to modify polymer fibers or fiber nonwoven webs or mats to achieve a conformal coating of a different second polymer on the fiber surface by grafting. Conformal coating refers to a coating that conforms to the curvature of the cylindrical or irregular shapes of fibers, thus achieving full coverage of the fibers by a uniform thickness of the grafted polymer. Conformal coatings are required for nonwoven system applications that necessitate complete control of surface properties, such as diagnostics, separations and other applications where the mats are to be exposed to complex mixtures.
[0011] The aim of the present invention is to modify polymer fiber surfaces by controlling the degree of etching and oxidization, which significantly improves the adhesion of initiators to the surface, and thus facilitates the subsequent conformal polymer grafting. The modified fiber surfaces render new functionalities to the surface such as increasing hydrophilicity, attaching ligands, or changing surface energy.
[0012] The present invention provides an alternative way to use UV activation to initialize grafting from that described in the prior art. While the current invention relies on the utilization of UV as a method to pretreat polymer substrates, it depends on a different effect of UV irradiation. It is well known that UV at certain wavelengths in combination with ozone can etch and oxidize polymer surfaces, leading to higher surface roughness and concentrations of hydroxyl and carbonyl groups [2, 3]. The present invention capitalizes on this effect in order to obtain an enhanced adsorption of initiators and a better contact between the polymer fiber surface and monomer from the solution to achieve a conformal coating. Advantageously, the invention does not rely on hydroperoxide for subsequent grafting. An external supply of ozone is not necessary, as ozone can be generated in air by UV at the same range of wavelength used for etching.
[0013] Rather than using a “grafting to” method as are known in the art, the present invention is a “grafting from” method, by which polymer grafts are grown from the substrate surface in a monomer and initiator solution. As the examples will show, without proper pre-treatment, it is impossible to get conformal grafting on certain types of polymer fibers, such as those of polyolefins. This is due to the mismatch of surface energies between the substrate polymer and the second polymer.
[0014] In further contrast to what is taught by the prior art, it has been found that in order to achieve a high density conformal coverage on polyolefin fibers, the presence of a photosensitizer or thermally decomposable initiators is/are indispensable, because the invention focuses on polymer nonwovens which are not photoactive. Moreover, it has been observed that peroxide compounds and radicals generated from the pre-treatment step are far less from sufficient to achieve a conformal coating. Therefore, a combination of a photosensitizer and a monomer is necessary for this purpose. However, contrary to the prior art, the photosensitizer is applied only in the monomer solvent at room temperature, which prevents it from decomposing.
[0015] Other objects, advantages and features of the present invention will become apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 —Polypropylene (PP) nonwoven fibers before and after grafting: A) Original PP nonwoven fibers; B) Surface of an original single PP nonwoven fiber; C) Grafted PP nonwoven before washing; D) Surface of a grafted single PP nonwoven fiber before washing; E) Grafted nonwoven after washing: and F) Surface of a grafted single PP nonwoven fiber after washing.
[0017] FIG. 2 —Cross sections of PP nonwoven fibers before and after grafting: A) Original PP nonwoven fibers; B) Cross section of an original single PP nonwoven fiber; C) Grafted PP nonwoven fibers; and D) Cross section of a grafted single PP nonwoven fiber.
[0018] FIG. 3 —FTIR of original PP, UV pre-treated PP, pure polyglycidyl methacrylate (PGMA) and PGMA-grafted PP.
[0019] FIG. 4 —PP nonwoven grafted at I:M=1:5: A) Grafted PP nonwoven fibers; B) surface of a grafted single PP nonwoven fiber; C) Cross section of PP nonwoven fibers; and D) Cross section of a grafted single PP nonwoven fiber.
[0020] FIG. 5 —SEM images of PGMA grafted PP fibers after 0-30 minutes of UV/O treatments: A) Zero (0) minutes; B) Five (5) minutes; C) Fifteen (15) minutes; and D) Thirty (30) minutes.
[0021] FIG. 6 —SEM Images of PGMA grafted PP nonwoven webs after 0, 15 and 30 minutes pre-treatment and the same 30 minutes grafting: A) Zero (0) minutes; B) Fifteen (15) minutes; and C) Thirty (30) minutes.
[0022] FIG. 7 —Relative benzophenone (BP) absorption as a function of UV pre-treatment time measured at different immersion times.
[0023] FIG. 8 —Comparison of grafting efficiencies: A) Grafting efficiency as a function of grafting time for samples at different pre-treatment times; and B) Grafting efficiency as a function of BP adsorption at different grafting times.
[0024] FIG. 9 —Influence of monomer and initiator concentration on grafting efficiency.
[0025] FIG. 10 —Nylon nonwoven fiber before and after grafting: A) A single original nylon nonwoven fiber; B) Surface of an original nylon nonwoven fiber; C) A single grafted nylon nonwoven fiber; and D) Surface of a grafted nylon nonwoven fiber.
[0026] FIG. 11 —Grafting on PBT nonwoven web with and without pre-treatment: A) Original PBT nonwoven; B) Grafted PBT nonwoven with pre-treatment; and C) Grafted PBT nonwoven without pre-treatment.
[0027] FIG. 12 —Difference in grafting effect between soaking substrate in BP and pre-treatment with UV/O: A) Soaking with BP; and B) UV ozone pre-treatment.
[0028] FIG. 13 —Transmittances of UV light through the dry PP nonwoven stack and PP nonwoven stack soaked with monomer solution.
[0029] FIG. 14 —Transmittances of UV light through PP nonwovens of different pore sizes.
[0030] FIG. 15 —Variation of grafting efficiency depending on the pre-treatment as a function of positions inside the nonwoven.
[0031] FIG. 16 —Variation of grafting efficiency depending on grafting as a function of position inside the nonwoven.
DETAILED DESCRIPTION OF THE INVENTION
[0032] This invention concerns a process to modify polyolefin (polypropylene) fibers or their nonwoven webs or mats to achieve a conformal coating of a different second polymer on the fiber surface by grafting. The process can also be applied to other polymer fibers, such as, without limitation, cellulose (cotton), polyamide (nylon), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), poly (phenol formaldehyde) (PF), polyvinylalcohol (PVOH), polyvinylchloride (PVC), aromatic polyamid (Twaron, Kevlar and Nomex), polyacrylonitrile (PAN), and polyurethane (PU), among others. The process depends on high density surface grafting polymerization of the second polymer on the fiber substrate. A conformal coating of second polymer on the fiber surface can always be warranted this way because the coverage of the graft on the fiber surface is high and chemical bonds formed between the graft and substrate create a huge energy barrier to prevent coating separation from happening.
[0033] The process starts with exposing fibers or their nonwoven web to UV irradiation in the range between 150 to 300 nm in air. During the exposure, ozone is simultaneously generated as a result of O 2 exposure to UV light. The objective behind the use of UV irradiation plus ozone treatment in this invention is not to generate radicals or peroxides on the fiber surface. Instead, the goal is to etch the surface to increase its roughness, and simultaneously to increase the concentration of hydroxyl and other oxygen-containing compounds [2, 3]. The combined effect significantly increases the adsorption of initiators in the subsequent grafting step. (See Example 5.)
[0034] Polymer fibers may have a smooth or glazed surface, which is the consequence of the fiber production conditions, as the polymer melts or solution passes through a fine nozzle at very high speed. A glazed surface prevents other molecules from attaching to the surface. On the other hand, a rough surface can increase the adsorption of other molecules, such as initiators, to the surface [8-10]. Initiators are molecules that can produce free radicals under mild conditions and initialize radical polymerization reactions. The interactions between polar groups such as hydroxyl and other oxygen containing compounds, and initiators, can further help stabilizing the adsorption [11]. UV irradiation plus ozone is very effective in etching only a very thin layer of the fiber surface to increase its roughness and simultaneously generating hydroxyl and carbonyl groups. Other approaches, such as plasma treatment, peroxide oxidation, base and acid or any method which can increase surface roughness and render oxidization, can also be used for this purpose.
[0035] Some polymers are made from monomers which already containing polar groups, such as amines, carbonyls and hydroxyls etc. Initiators may adsorb to these surfaces to such an extent that a conformal coating can be obtained even without pre-treatment. However, for polymer containing only hydrocarbons, e.g. polyolefins, pre-treatment is indispensable for a conformal coating.
[0036] After pre-treatment, the functional monomers can be grafted to the surface by free radical polymerization. This process can use UV-initialized radical polymerization or thermally-initialized radical polymerization. Photosensitizers and thermally decomposable initiators should be used in the respective processes. Photosensitizers include benzophenone, anthraquinone, naphthoquinone or any compound involving hydrogen abstraction for initialization. Thermally decomposable initiators include azo compounds or peroxide compounds. The monomer concentration is in the range of 1 to 20%. The initiator concentration is in the range of 0.5 to 7%. Alcohols and hydrocarbons can be used as solvents. The grafting is carried out between approximately 1 and 120 minutes.
[0037] Depending on the expected functionalities, a variety of acrylate monomers can be selected for grafting, for example, 2-hydroxylethyl methacrylate, acrylamide, acrylic acid, acrylonitrile, methyl methacrylate, glycidyl methacrylate and similar acrylate derivatives. In addition, any monomer which can be polymerized by radical polymerization can be used for grafting.
[0038] A continuous UV irradiation of 300-450 nm is required for UV-initialized grafting. A pre-treated substrate pre-soaked with the solution of monomer and photosensitizer is inserted between two thin glass plates (or a confined geometry) and exposed to UV for a determined amount of time. Confined geometry, forming a saturated vapor phase near the surface of the substrate, has the advantage of preventing fast loss of solvent. The confined geometry also minimizes the grafting solution and allows for the absence of degassing and inert gas protection. Before use, the glass plates may be pre-treated with mold release agents, for example Frekote®.
[0039] The grafting can be performed at room temperature or at an elevated temperature, but far below the boiling temperature of monomer solution. Cooling is necessary when solvent evaporates too fast.
[0040] An elevated temperature is required for thermally-initialized grafting, where initiators can decompose efficiently. Same confined geometries can also be used.
[0041] After grafting, the substrates are washed with appropriate solvents to extract unreacted monomers and unattached homopolymers. Water is a good solvent for monomers and homopolymers which are aqueous soluble. Otherwise, extraction can be done by alcohols, hydrocarbons, or with any other suitable solvent.
EXAMPLE 1
[0042] A specimen of polypropylene (PP) nonwoven 250 μm thick and of dimensions 2×4 cm was exposed to UV irradiation of 150 to 300 nm (UV/O) and intensity 50 mw/cm 2 for 15 minutes. The substrate was then soaked with 20% glycidyl methacrylate and benzophenone (Initiator:Monomer or I:M=1:25) in butanol solution. The substrate was sandwiched between two glass slides coated with Frekote®, and then exposed to UV of 300 to 450 nm and intensity 5 mw/cm 2 for 15 minutes for grafting. The grafted nonwoven substrate was then washed by sonication in THF and methanol to remove unreacted and unattached compounds.
[0043] FIGS. 1A ) and B) show the original PP nonwoven web and fiber. The surface of the original PP fiber is covered with cracks as a result of melt-blown process. FIGS. 1C ) and D) show the nonwoven web and fiber after grafting, but before washing. Very smooth coatings are formed on the fibers. However, these coatings are not permanent. FIGS. 1E ) and F) show the nonwoven web and fiber after washing. A high density coarse polyglycidyl methacrylate (PGMA) coating is covalently attached to the fiber surface. The porous structure of the web has not been changed.
[0044] FIGS. 2A ) and B) show the cross-sections of the original PP nonwoven web and fiber. FIGS. 2C ) and D) show the cross-sections after grafting. As it may be seen, the grafting is very conformal to the cylindrical and even irregular shaped fibers. The thickness is difficult to measure due to low contrast between the coating and fiber. It is estimated at between approximately 100 and 200 nm.
[0045] FIG. 3 shows the FTIR spectra of original PP, UV-pre-treated PP, pure PGMA and PGMA-grafted PP. The characteristic peak at 1720 cm −1 on the grafted nonwoven is a clear evidence of PGMA grafting.
EXAMPLE 2
[0046] Grafting results shown in FIG. 4 were from the same process producing FIGS. 1E ) and F) in Example 1, except that in Example 2 the benzophenone to monomer ratio (I:M) was 1:5. The results in FIG. 4 clearly indicate that this technique can change the morphology of the coating from very coarse to very smooth by simply adjusting the benzophenone to monomer ratio.
EXAMPLE 3
[0047] Four specimens of polypropylene nonwoven 250 μm thick and of dimension 2×4 cm were exposed to UV irradiation of 150 to 300 nm and an intensity of 50 mw/cm 2 for 0, 5, 15 and 30 minutes, respectively. The pre-treated samples were then grafted with PGMA in the same way as in Example 1. FIG. 5 indicates that both density and conformity of PGMA graft increase with the time of UV/O treatment.
EXAMPLE 4
[0048] Three specimens of polypropylene nonwoven 250 μm thick and of dimension 2×4 cm were exposed to UV irradiation of 150 to 300 nm and intensity 50 mw/cm 2 for 0, 15 and 30 minutes, respectively. The pre-treated samples were then grafted with PGMA in the same way as Example 1, except the grafting time was 30 minutes for this example. Approximately twice as much grafting as that for 15 minutes was obtained. However, an increase in grafting efficiency does not necessarily increase the conformity of the graft. In FIG. 6 , without pre-treatment, the grafting is not conformal to the fibers, which is in contrast with conformal grafting after 15 minutes and 30 minutes pre-treatment.
EXAMPLE 5
[0049] Adsorption of benzophenone on the PP fiber surface as a function of UV/O pre-treatment time was measured by the following procedure. The samples were first pre-treated for designated periods. Then, they were immersed into a 1.3% (w/w) benzophenone in butanol solution absent of UV irradiation. The concentration of benzophenone was the same as that used in the 20% grafting solution, and the immersion times were 1, 10, 15 and 30 minutes. After immersion, the samples were taken out, hard-pressed between two paper towels (Wypall® X60, Kimberley Clark) to remove the solution trapped in the pores, dried in air and analyzed by FTIR-ATR.
[0050] In FIG. 7 , relative BP adsorption values are plotted as a function of pre-treatment time. The standard error was estimated from data measured at different spots on the same specimen. The adsorption curves clearly indicate that BP adsorption increases with UV/O pre-treatment time. This can be explained as the result of increased roughness and concentration of hydroxyl groups from pre-treatment. Furthermore, regardless of various immersion times, adsorption curves collapse into a single curve within the experimental error. This implies that upon contacting BP solution, equilibrium of BP was quickly established between the solution and the fiber surface.
[0051] Since grafting density depends on the initiator density on a substrate, PP nonwoven pre-treated with UV/O leads to deeply enhanced conformity of the graft.
EXAMPLE 6
[0052] Specimens of polypropylene (PP) nonwoven 250-μm thick and of dimensions 2×4 cm were exposed to UV irradiation of 150 to 300 nm (UV/O) and intensity 50 mw/cm 2 for 0 to 15 minutes. The specimens were then soaked with 20% glycidyl methacrylate and benzophenone (I:M=1:25) in butanol solution, sandwiched between two glass slides coated with Frekote®, and then exposed to UV of 300 to 450 nm and intensity 5 mw/cm 2 for grafting of various durations. The grafted nonwoven substrate was washed by sonication in THF and methanol to remove unreacted and unattached compounds.
[0053] FIG. 8A ) shows that the grafting rate increases with the pre-treatment time. The increases are due to the initiator density or the adsorption of benzophenone on the fiber surface which increases with the pre-treatment time. High initiator density leads to more grafting sites on the surface. Therefore, the overall grafting rate is higher. It is also interesting to note that all the samples show a lag period of ˜5 minutes. This lag period is presumably from the trapped oxygen in the system which can delay the starting of the grafting. In addition, the curves for 10 and 15 minutes pre-treatments overlap with each other. This suggests that they have similar grafting rates despite their difference in initiator density. It has been hypothesized that not all the initiators on the surface are used for initializing graft because they are inhibited by steric effects from nearby grafts [12]. Therefore, there exists a cut-off initiator density, and the grafting rate increases little beyond that density.
[0054] FIG. 8B ) shows the grafting efficiencies measured at constant grafting times as a function of BP adsorption. Grafting efficiencies show a strong dependence on low initiator densities, but weak dependence on high initiator densities. The cut-off density lies around a relative BP adsorption of 0.08.
EXAMPLE 7
[0055] Specimens of polypropylene (PP) nonwoven 250 μm thick and of dimensions 2×4 cm were exposed to UV irradiation of 150 to 300 nm (UV/O) and an intensity of 50 mw/cm 2 for 0 to 15 minutes. The specimens were then soaked with 10, 15 or 20% glycidyl methacrylate and benzophenone (I:M=0 to 1:4) in butanol solution, sandwiched between two glass slides coated with Frekote®, and then exposed to UV of 300 to 450 nm and intensity 5 mw/cm 2 for grafting of various durations. The grafted nonwoven substrate was washed by sonication in THF and methanol to remove unreacted and unattached compounds.
[0056] Grafting efficiencies at three monomer concentrations are plotted. For each concentration, the ratio between initiator to monomer was varied from 0 to 24%. As shown in FIG. 9 , the grafting efficiency increases rapidly at low initiator to monomer ratios (I:M) for all three monomer concentrations. When the ratio is above 2%, grafting efficiency reaches a plateau. The independence of grafting efficiency on the initiator is due to the fact that the initiator density on the fiber surface for these initiator concentrations is already above the cut-off BP density. Further increase of the initiator induces little change on the grafting efficiency.
EXAMPLE 8
[0057] A specimen of nylon-6, 6 nonwoven 140 μm thick and of dimensions 2×4 cm was exposed to UV of 150 to 300 nm and intensity 50 mW/cm 2 for 15 minutes (UV/O). The substrate was then soaked with 20% glycidyl methacrylate and 1.3% benzophenone solution with butanol as solvent. The substrate was sandwiched between two glass slides coated with Frekote®, and then exposed to UV of 300 to 450 nm and intensity 5 mW/cm 2 for 15 minutes. The grafted nonwoven substrate was then washed by sonication in THF and methanol to remove unreacted and unattached compounds. FIG. 10 shows that conformal grafting has been formed on the nylon fiber. Even though the surface energy of nylon is very different from PP, the same technique can generate conformal grafting for both materials.
EXAMPLE 9
[0058] A specimen of polybutylene terephthalate (PBT) nonwoven 160 μm thick and of dimension 2×4 cm was exposed to UV of 150 to 300 nm and intensity 50 mW/cm 2 for 15 minutes. Another specimen was not pre-treated at all. Both substrates were then soaked with 20% glycidyl methacrylate and benzophenone (I:M=1:25) in butanol solution. The substrate was sandwiched between two glass slides coated with Frekote®, and then exposed to UV of 300 to 450 nm and intensity 4 mW/cm 2 for 15 minutes. The grafted nonwoven substrate was then washed by sonication in THF and methanol to remove unreacted and unattached compounds. FIG. 11 shows that PBT fibers on the nonowoven have been grafted with high density and conformal PGMA graft. Without pre-treatment, conformal grafting can still be formed on the PBT fibers. This is due to the fact that PBT is more polar than PP, and dipole-dipole interactions between benzophenone and PBT improve its adsorption. As a result, a high density of initiator can be obtained even without pre-treatment.
EXAMPLE 10
[0059] A specimen of polypropylene nonwoven 250 μm thick and of dimension 2×4 cm was soaked in 100 mM benzophenone (˜2%) in methanol for 18 hours. Immediately after soaking, it was sandwiched between two glasses with 20% GMA and benzophenone (I:M=1:25) in butanol solution. The time for the grafting polymerization was 15 minutes. Another polypropylene nonwoven was treated in the same way as in Example 1. All the samples were extracted in THF overnight and washed by methanol. FIG. 12 clearly shows that the substrate pre-treated by UV/O exhibits much higher density of graft than soaking in the benzophenone.
EXAMPLE 11
[0060] Layers of nonwoven in the thickness of 40-60 μm were skimmed from the PP nonwoven 250 μm thick. Five skimmed layers were restacked together to obtain a nonwoven of the similar thickness to the original nonwoven. To study the effect of light penetration, nonwovens of different thicknesses were prepared. A UV sensor was placed on one side of the nonwoven stack with the sensor surface covered by the nonwoven and the UV lamp was placed the opposite side. The whole system was placed in an enclosure with the inside covered by black foil to avoid exposure to light from the surroundings. The distance between the sensor and light source were adjusted to obtain the desired initial intensity for each test.
[0061] FIG. 13 shows the transmittances of UV light through dry nonwoven and nonwoven soaked with monomer solution. It comes as a surprise that when the nonwoven fabric is soaked with monomer solution, its light intensity decays much more slowly than under the dry condition. Since the monomer solution is able to absorb UV light, it would have been a reasonable expectation that UV intensity should decay faster. The slowdown of the decay is actually related a phenomenon known as index matching. Basically, as the refractory index of the solvent is closer to that of substrate as compared to air, it can reduce the Fresnel reflection at the surface, and thus increase the net light transmission. The refractory index of PP is 1.471 [13], that for butanol is 1.397 [13] and that for air is ˜1.
[0062] Nonwovens made of the same material, but with different average pore sizes, show different penetration profiles. In FIG. 14 , as the average pore size decreases from 17.25 to 0 μm, the decay of the UV intensity versus depth increases.
[0063] Due to the decay of UV light through the nonwoven, grafting efficiency may also vary depending on the intensity of UV light exposed in both pre-treatment and grafting step. FIG. 15 shows the spatial variation of grafting efficiency caused by pre-treatment. FIG. 16 shows the spatial variation of grafting efficiency caused by grafting. Two controls, grafting with pre-treatment but without benzophenone (condition 2, b) and grafting without pre-treatment but with benzophenone (condition 3, c) are also plotted.
[0064] The plots of condition 1, a clearly show that the grafting efficiencies decreases as the depth increases. The plot of condition 2, b show only nominal grafting. These results indicate that without benzophenone grafting efficiencies are very low. If the nonwovens are not pre-treated, such as for condition 3, c, the spatial variation of grafting efficiencies is less than the treated nonwovens. But their grafting efficiencies are also much lower than those with pre-treatment.
[0065] The above-described embodiments of the invention are intended to be examples only. Variations, alterations and modifications can be made to the particular embodiments described herein by those of skill in the art without departing from the scope of the invention, as defined in the appended claims.
REFERENCES
[0000]
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11. L. F. Vieira Ferreira, J. C. Netto-Ferreira, I. V. Khmelinskii, A. R. Garcia, S. M. B. Costa, “Photochemistry on surfaces: matrix isolation mechanisms study of interactions of benzophenone adsorbed on microcrystalline cellulose investigated by diffusion reflectance and luminescence techniques,” Langmuir, 11, (1995), 231.
12. K. Matyjaszewski, P. J. Miller, N. Shukla, B. Immaraporn, A. Gelman, B. B. Luokala, T. M. Siclovan, G. Kickelbick, T. Valiant, H. Hoffmann, T. Pakula, “Polymers at interfaces: using atom transfer radical polymerization in the controlled growth of homopolymers and block copolymers from silicon surfaces in the absence of untethered sacrificial initiator,” Macromolecules, 32, (1999), 8716.
13. Polymer Handbook Fourth Edition (J. Brandrup, E. H. Immergut. E. A. Grulke), John Wiley & Sons, 1999. | The present invention describes a novel process for the conformal coating of polymer fibers on nonwoven substrates. This process is based on the modification of polymer fiber surfaces by controlling the degree of etching and oxidation, which improves adhesion of initiators to the surface and facilitates subsequent conformal polymer grafting. The modified fiber surfaces render new functionalities to the surface, such as increasing hydrophilicity, attaching ligands or changing surface energy. The invention includes the modified polymer fibers produced by the process described herein. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to sheet-fed printing press, or more precisely, to such printing press with sheet perfecting apparatus.
[0003] 2. Description of the Prior Art
[0004] Satellite-type printing press is known in which many printing units (four color units, for example) are provided in satellite-like manner around common pressure cylinder of large diameter. Such satellite-type printing press is a new step toward corresponding to the need of multi-sort short run printing.
[0005] In Japanese unexamined patent laid-open 244195/1996, a technique is disclosed in which a plurality of satellite-type printing presses are connected via sheet perfecting apparatus. According to the technique, four color printing is done on the surface of sheet by first satellite-type press and, after reversing the sheet, also four color printing is put on the opposite side of the sheet by the second satellite-type press.
[0006] From Japanese unexamined patent laid-open 169645/1987, for example, a technique is well known in which many printing units are connected in series and sheet perfecting apparatus is interposed therein.
[0007] It is true that both sides of sheet can be printed at one pass by the satellite-type printing press shown in before-mentioned Japanese unexamined patent laid-open 244195/1996, but the equipment is huge and switching of printing format is not at all flexible, as the technique presupposes two satellite-type printing units.
[0008] Also, before-mentioned sheet perfecting apparatus of series type printing press has a tendency to cause register error through gripping change of sheet, as the perfecting apparatus stays the sheet transfer path during one-side printing in which sheet perfecting is not needed.
SUMMARY OF THE INVENTION
[0009] In view of the above-described problems of the prior art technique, the present invention provides an improved satellite-type printing press and aims at enabling double-side printing by only one satellite-type printing press itself, and preventing register error without intervening with sheet transfer path in case sheet reversing is not needed.
[0010] In accordance with satellite-type printing press according to the present invention, in the course of printing units of one satellite-type press itself, sheet perfecting apparatus is provided which functions only in double-side printing for sheet reversing and, in case of one-side printing, does not intervene with sheet transfer path.
[0011] More concretely, satellite-type printing press according to the present invention comprises;
[0012] Common pressure cylinder with grippers for sheet transfer to which are connected sheet feeder in the upper stream of sheet transfer and sheet delivery in the lower stream,
[0013] at least four sets of printing units which are provided in satellite-like manner around said common pressure cylinder,
[0014] sheet perfecting apparatus which is provided in the course of printing units and separable from sheet transfer path,
[0015] and said apparatus comprises, from the upper stream to the down stream of sheet transfer path, first transfer cylinder, perfecting cylinder and second transfer cylinder.
[0016] According to the present invention, double-side printing of, for example, two colors on surface as well as two colors on backside is possible by only one satellite-type press in which sheet perfecting apparatus is provided between second and third printing units.
[0017] In one-side printing, sheet perfecting apparatus does not intervene with sheet transfer path, therefore, high register accuracy is secured even in four color printing.
[0018] These and other objects of the present invention will become apparent from the following description with reference to the drawings. But, these show merely an embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a schematic view showing an embodiment of satellite-type printing press according to the present invention.
[0020] FIGS. 2 to 8 are functional illustrations of sheet perfecting apparatus provided in the satellite-type printing press according to the present invention.
[0021] [0021]FIG. 9 is a block diagram for controlling the speed of perfecting cylinder in sheet perfecting apparatus.
[0022] [0022]FIG. 10 is a speed diagram of perfecting cylinder in compliance with variation of sheet length.
DESCRIPTION OF PREFERRED EMBODIMENT
[0023] In the center of FIG. 1, common pressure cylinder 10 of relatively large diameter is shown which is rotatably supported between a pair of side frames 12 of printing press and is driven by motor (not shown). The common pressure cylinder 10 has, as shown in FIG. 2 and so on, grippers 16 which grip the end of sheet. The common pressure cylinder 10 is a base for accepting sheet 14 from feeding cylinder 20 of sheet feeder 18 in the upper stream and, after printing, for delivering the printed sheet to delivery chain 24 of sheet delivery device 22 in the lower stream.
[0024] Four sets of printing units 26 are provided in satellite-like manner around the common pressure cylinder 10 . In order to perform offset printing, these printing units 26 have plate cylinder 28 equipped with printing plate and blanket cylinder 30 to transfer images. In addition, the plate cylinder 28 has inking device 32 and damping system 34 . The diameter of the common pressure cylinder 10 around which printing units 26 are provided in satellite-like manner is integer times (for example, four times) as large as that of plate cylinder 28 in order to perform multi-color printing by these printing units 26 in compliance with the rotation of the common pressure cylinder 10 which is driven by motor (not shown).
[0025] Sheet perfecting apparatus 36 according to the present invention is provided between second and third printing units 26 , basing upon rotational direction of common pressure cylinder 10 (counterclockwise in FIG. 1). From upper stream to down stream of sheet transfer path, the sheet perfecting apparatus 36 comprises first transfer cylinder 38 , perfecting cylinder 40 and second transfer cylinder 42 .
[0026] Such type of sheet perfecting apparatus 36 with three cylinders is well known in the prior art series-type printing press. Two transfer cylinders 38 , 42 can, as shown in FIG. 8, be detachable from common pressure cylinder 10 by so-called cylinder throw-off. Needless to say, such cylinder throw-off (and throw-in as well) mechanism utilizing crank and cam is ordinarily equipped in blanket cylinder of offset press.
[0027] Next, sheet perfecting apparatus 36 is described with reference to functional illustrations of FIGS. 2 to 7 . Two colors are printed on the surface of sheet 14 by blanket cylinder 30 of first and second printing units 26 . Front end of sheet 14 is gripped by gripper 16 of common pressure cylinder 10 and then the front end is led to gripper 44 of first transfer cylinder 38 at opposing point P 1 of common pressure cylinder 10 against first transfer cylinder 38 (FIG. 2).
[0028] In accordance with the rotation of first transfer cylinder 38 , front end reaches at opposing point P 2 of first transfer cylinder 38 against perfecting cylinder 40 (FIG. 3), but sheet end is not transferred at this moment to perfecting cylinder 40 and rotation continues. Rear end of sheet 14 is sucked and broadened by sucker 46 (FIG. 4).
[0029] When rear end of sheet 14 reaches at opposing point P 2 of perfecting cylinder 40 , gripper 48 of perfecting cylinder 40 grips the rear end (FIG. 5) and, following the rotation of perfecting cylinder 40 , sheet 14 is reversed.
[0030] Reversed sheet 14 is then transferred to gripper 50 of second transfer cylinder 42 at opposing point P 3 of perfecting cylinder 40 against second transfer cylinder 42 (FIG. 6) and further transferred to gripper 16 of common pressure cylinder 10 (FIG. 7).
[0031] Hereafter, third and fourth printing units 26 which are also provided in satellite-like manner around common pressure cylinder 10 further print on backside of sheet 14 which is already reversed by sheet perfecting apparatus 36 and finally double-side printing of two colors on surface as well as two colors on backside is completed.
[0032] In the foregoing descriptions, sheet 14 to be printed by satellite-type press according to the present invention is supposed to have a fixed length. But, sheet length (length of sheet 14 in its running direction.) is various and, under some conditions, sheet reversing pace must be raised in order to cope with printing speed. As described, press itself is, including each printing unit 26 , timely driven by motor (not shown). To comply with sheet length variation to be printed, perfecting cylinder 40 of sheet perfecting apparatus 36 is preferably driven by servo motor (not shown) which is independent from motor of printing press. Further, servo motor speed is controlled in compliance with sheet length in its printing cycle so as to adapt sheet reversing pace to printing speed.
[0033] [0033]FIG. 9 is a block diagram, showing speed control of perfecting cylinder 40 by independent servo motor. Rotation speed of printing press is always monitored by, for example, rotary encoder (Step 1 ). In addition, sheet length is, prior to printing, input into control console of press (Step 2 ). In control console, speed control data for servo motor of perfecting cylinder 40 is created in compliance with input sheet length (Step 3 ) and, receiving speed control data, rotation speed of servo motor is in- or decreased (Step 4 ). Finally, rotation speed of perfecting cylinder 40 is, in its one printing cycle, adjusted (Step 5 ).
[0034] [0034]FIG. 10 schematically shows rotation speed variation of perfecting cylinder 40 in compliance with sheet length variation. Lateral axis shows rotation mode in one printing cycle from 0 to 360 degree and longitudinal axis shows rotation speed of perfecting cylinder 40 . In sheet receiving section TI as well as sheet transferring section T 2 , relative speed of perfecting cylinder 40 in relation to first and second transfer cylinders 38 , 42 is 0. But, after receiving sheet 14 , rotation speed must be increased in compliance with sheet length in order to prepare sheet transfer. The case sheet length is long is shown in bold line and dot line shows the case sheet length is short.
[0035] According to the present invention, double-side printing of, for example, two colors on surface as well as two colors on backside can be done by only one satellite-type printing press. In surface printing (one-side printing), sheet perfecting apparatus does not intervene with sheet transfer path by so-called cylinder throw-off, therefore, high register accuracy is secured. Further, various sheet length can, without difficulty, be accepted.
[0036] The present invention is not limited to the embodiment described hitherto. Various changes and modifications can, of course, be made without departing from the spirit of the invention.
[0037] Description of the Reference Numerals
[0038] [0038] 10 common pressure cylinder
[0039] [0039] 14 sheet
[0040] [0040] 16 gripper
[0041] [0041] 18 sheet feeder
[0042] [0042] 22 sheet delivery
[0043] [0043] 24 delivery chain
[0044] [0044] 26 printing unit
[0045] [0045] 36 sheet perfecting apparatus
[0046] [0046] 38 first transfer cylinder
[0047] [0047] 40 perfecting cylinder
[0048] [0048] 42 second transfer cylinder
[0049] [0049] 44 gripper
[0050] [0050] 46 sucker
[0051] [0051] 48 perfecting gripper
[0052] [0052] 50 gripper | Sheet-fed printing press, especially, satellite-type printing press is disclosed by which double-side printing is performed with single satellite-type press and, in case sheet reversing is not needed, sheet perfecting apparatus does not intervene with sheet transfer path.
In the concrete, in the course of many printing units 26 which are provided in satellite-like manner around common pressure cylinder 10, sheet perfecting apparatus 36 which is separable from sheet transfer path is provided and the apparatus comprises first transfer cylinder 38, perfecting cylinder 40 and second transfer cylinder 42. | 1 |
TECHNICAL FIELD
[0001] This invention generally relates to processing documents with metadata tags. More particularly, the invention relates to inserting metadata tags in documents as the documents are being processed.
BACKGROUND
[0002] Everyday, an untold number of documents are produced that must be preserved so they can be referenced at a later date. These documents may be in the conventional paper form or they may be electronic documents. In fact, as our culture grows increasingly dependent on computer-generated information, it is quite likely that a majority of documentation produced today is in electronic form. Paper documents are frequently scanned so they may be archived in electronic form. The enormous amount of information stored in electronic documents on computer databases is becoming easier to access as the public becomes more and more familiar with the Internet and with computer research techniques.
[0003] To aid in searching through the virtually endless number of documents, metadata tags are sometimes included in electronic documents. Metadata is high-level data that describes lower-level data. In other words, a metadata tag that describes an electronic document can be inserted into the electronic document before the electronic document is stored. A metadata tag in an electronic document usually contains key words and phrases from the document that are likely to be used as search terms for someone who is searching for similar documents. For example, a metadata tag may contain a document title and several words about the subject and/or the author of the document.
[0004] That way, when a computerized search engine is directed to search for documents that meet certain requirements, the search engine can more efficiently search the documents by scanning only the metadata tags associated with the documents instead of the entire documents.
[0005] Additionally, scanned documents are typically stored as image-only documents that do not comprise searchable text in a stored form. Adding metadata tags to image-only documents provides a way to search many such documents. For example, keywords, profile information, and the like may be stored together with an image-only document to allow one to more easily search for documents of interest and zero in on its content of interest.
[0006] Large enterprises that utilize archived electronic databases and computerized search tools use metadata tags to organize large bodies of work. But metadata tags are typically, if not always, entered manually and can be time consuming and expensive. Efficient methods and systems that lower the time and manpower required to insert metadata tags into documents would make such systems more cost beneficial and desirable for certain enterprises.
SUMMARY
[0007] Systems and methods are described herein for inserting metadata tags into electronic documents. For paper documents to be converted to electronic documents, they must go through a scanning process. When a paper document is scanned and converted into an electronic document, a multi-pass image analysis is performed on the electronic digital representation of the scanned document. Then the electronic document is displayed—at least in part—to a user. The user is provided with the capability to enter metadata tags at that time. In one implementation, the metadata tag is defined and inserted by the user when the document is displayed. In another implementation, the user is presented with a list of pre-configured metadata tags. When the user selects a metadata tag from the list, the selected metadata tag is inserted into the electronic document. After the metadata tag is inserted into the electronic document, the electronic document is stored on some type of computer-readable medium.
[0008] In another implementation, the document originates as an electronic document and does not have to be converted from a paper document to an electronic document. In such a case, the electronic document is received and is displayed to a user so that the user may insert metadata into the document.
[0009] In one or more implementations, computational algorithms are used to locate particular regions of interest in documents. Such regions are automatically detected, bounded and tagged for subsequent specialized processing applicable to the particular region. This saves computational and storage resources because regions of a document have differing OCR and storage requirements as well as meaning to the targeted recipient or repository. Some examples of computational algorithms include background color detection, location of text only regions as opposed to pictures, location of meaningful symbols or shapes, locating barcodes, locating patterns invisible to the naked eye, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings. The same numbers are used throughout the figures to reference like components and/or features.
[0011] [0011]FIG. 1 is a block diagram of an exemplary document processing system.
[0012] [0012]FIG. 2 is a flow diagram depicting a methodological implementation of the document processing system shown in FIG. 1.
[0013] [0013]FIG. 3 is a block diagram of an exemplary scanner.
[0014] [0014]FIG. 4 is flow diagram depicting a methodological implementation of the scanner shown in FIG. 3.
DETAILED DESCRIPTION
[0015] The following description sets forth one or more specific implementations and/or embodiments of systems and methods for inserting metadata tags into electronic documents. The systems and methods incorporate elements recited in the appended claims. These implementations are described with specificity in order to meet statutory written description, enablement, and best-mode requirements. However, the description itself is not intended to limit the scope of the present invention.
[0016] Also described herein are one or more exemplary implementations of systems and methods for inserting metadata tags into electronic documents. Applicant intends these exemplary implementations to be examples only. Applicant does not intend these exemplary implementations to limit the scope of the claimed present invention. Rather, Applicant has contemplated that the claimed present invention might also be embodied and implemented in other ways, in conjunction with other present or future technologies.
[0017] Computer-Executable Instructions
[0018] An implementation of a system and/or method for inserting metadata tags into electronic documents is presented and may be described in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.
[0019] Computer-Readable Media
[0020] An implementation of a system and/or method for inserting metadata tags into electronic documents may be stored on or transmitted across some form of computer-readable media. Computer-readable media can be any available media that can be accessed by a computer. By way of example, and not limitation, computer readable media may comprise “computer storage media” and “communications media.”
[0021] “Computer storage media” include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer.
[0022] “Communications media” typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier wave or other transport mechanism. Communication media also includes any information delivery media.
[0023] Exemplary Document Processing System
[0024] [0024]FIG. 1 is a block diagram of an exemplary document processing system 100 constructed in accordance with an implementation of the present invention. The document processing system 100 is shown in conjunction with a database 102 and a scanner 104 , though it is noted that the document processing system 100 may be incorporated into a scanner in other implementations that will be described below.
[0025] The document processing system 100 includes a processor 106 and an input/output (I/O) module 108 that handles transfer of electronic data to and from the document processing system 100 . The document processing system 100 also includes a communications module 110 that allows the document processing system 100 to communicate with other electronic devices via a network, the Internet, etc., a keypad 112 through which character data can be entered into the document processing system 100 , and a display 114 .
[0026] The document processing system 100 includes memory 116 , which stores electronic data, including an operating system 117 that controls the function of the document processing system 100 . A document input module 118 is stored in the memory 116 and is configured to receive an electronic document 120 from the scanner 104 or by some other method. An interface module 122 is stored in the memory 116 and presents the electronic document 120 on the display 114 .
[0027] The memory 116 also stores a pointing device driver 124 that controls commands and data received from and sent to a pointing device 126 . The pointing device 126 may be any known device used to indicate a position 7 such as a cursor position—in the electronic document, such as a mouse, a stylus, a trackball, a touchpad, etc. If the pointing device 126 is a stylus, it is noted that the display 114 must be a touch screen that is responsive to indications made with the stylus.
[0028] The memory 116 also includes a computational algorithm module 127 that may be used to automatically determine portions of one or more of the scanned documents that are tagged for specialized processing to follow. The computational algorithm module 127 may also be programmed to apply a context sensitive algorithm to a scanned document or a set of scanned documents. Some examples of such algorithms include, but are not limited to, the following.
[0029] A background color detection algorithm identifies one or more portions of a document that have a particular background and scans only those portions. An algorithm that identifies locations of text only regions only scans portions of the document containing text and disregards pictures or figures. An algorithm that locates meaningful symbols or shapes only scans portions of a document that contain pre-identified symbols or shapes. A barcode algorithm locates and scans barcodes contained in a document while ignoring other portions of the document. An algorithm can locate patterns that are invisible to the naked eye and scan document areas in which those patterns are found.
[0030] A document output module 128 is stored in the memory 116 and is configured to output selected portions of the electronic document 120 to the database 102 . It is noted that, in the present example, that either the database 102 and/or the scanner 104 is optional. The scanner 104 may not be required if the electronic document 120 is received in electronic form. Also, the database 102 may not be required if the electronic document 120 has some other destination, such as removable magnetic media, a network, etc. In the following discussion, those skilled in the art will recognize that different embodiments of the invention may be implemented depending on the document processing that is required.
[0031] A metadata tag insertion module 130 is stored in the memory 116 and is configured to insert a metadata tag into the electronic document 120 . A metadata tag list 132 is included in the metadata tag insertion module 130 and stores one or more pre-configured metadata tags 134 for selection during the metadata tag insertion process. The pre-configured metadata tags 134 may be pre-configured to describe different types of standard documents. For example, if several documents are expected to relate to a similar subject matter, a metadata tag can be created for the subject matter so that the metadata tag does not have to be created each time the metadata tag 134 is desired to be inserted into the electronic document 120 . Instead, a user can simply select the pre-configured metadata tag 134 from the metadata tag list 130 for insertion into the electronic document 120 .
[0032] A paper document (not shown) is processed by the scanner 104 to create the electronic document 120 . Alternatively, the electronic document 120 may be input to the document processing system 100 in an electronic format via the communications module 110 or the I/O module 108 . Once the electronic document 120 has been received by the document processing system 100 , the interface module 122 displays at least a portion of the electronic document 120 on the display 114 . Typically, the portion of the electronic document 120 displayed will be one page of the electronic document 120 , the page size depending on the size of the display. However, only a portion of a document page may be selected as described above.
[0033] The pointing device 126 is utilized to indicate a position in the electronic document 120 , for example, for a cursor location. The implementation of the position indicating may be any method known in the art, such as with a stylus and touch screen, a mouse, etc. For purposes of discussion, it is assumed that indication of a location in the electronic document 120 is accomplished by using a stylus to communicate with a touch screen display.
[0034] Once the position has been identified to insert a metadata tag, the metadata tag is inserted into the electronic document. This may be done by one of several ways. When the position is selected, a pop-up menu of predefined tags may provide tags from which the user may choose to insert into the document. Or a prompt may be displayed, at which point the user enters text to be associated with the tag.
[0035] After the metadata tag 134 is inserted into the electronic document 120 , it may be stored separately as a tagged electronic document 136 . The tagged electronic document 136 will typically be in the form of the electronic document 120 with the additional metadata contained in the metadata tag 134 .
[0036] When the tagging process is complete, the tagged electronic document 136 may be transmitted to another location. In the present example, the document output module 128 prepares the tagged electronic document 136 for transmission. As previously stated, the electronic document 120 may be stored in the database 102 or sent to another location over a network, stored on removable magnetic media, etc.
[0037] Methodological Implementation: Document Processing System
[0038] [0038]FIG. 2 is a flow diagram depicting a methodological implementation of the exemplary document processing system 100 shown in FIG. 1. Continuing reference will be made to the elements and reference numerals of FIG. 1 in the following discussion of FIG. 2.
[0039] At block 200 , a document is scanned to create an electronic document. Alternatively, the electronic document 120 may be input to the document processing system 100 in an electronic format via the communications module 110 or the I/O module 108 . At block 201 , a multi-pass image analysis is performed wherein one or more portions of the electronic document are selected. The one or more portions may be identified by the computational algorithm module 127 , may be accomplished manually, or the entire document may be selected for multi-pass image analysis. In addition to tasks specifically defined herein, the multi-pass image analysis process is also used to perform the task of automatically adding or embellishing metadata tags that can be manually edited or deleted or left intact by a user later in the process, i.e., in the steps outlined below.
[0040] Once the electronic document 120 has been received by the document processing system 100 , the interface module 122 displays at least a portion of the electronic document 120 —a document preview—on the display 114 at block 202 . Typically, the portion of the electronic document 120 displayed will be one page of the electronic document 120 , the page size depending on the size of the display.
[0041] At block 204 , a decision is made whether a metadata tag 134 needs to be inserted into the electronic document 120 . If no metadata tag 134 is required (“No” branch, block 204 ), then the document is stored (or transferred) at block 212 . If a metadata tag 134 should be inserted into the electronic document 120 (“Yes” branch, block 204 ), then the process continues at block 206 .
[0042] The metadata tag list 132 is displayed at block 206 and includes the metadata tag 134 . The pointing device 126 is utilized to select the metadata tag 134 and to identify a location in the electronic document 120 where the metadata tag 134 is to be inserted (block 208 ). Metadata tags can be embedded in the original scanned document in such a way to not interfere with documents presentation or tags can be stored in a separate but associated file. At block 210 , the metadata tag 134 is inserted into the electronic document 120 to create the tagged electronic document 136 .
[0043] In one implementation, the metadata tag list 132 is not required. Rather, a user may define the metadata tag 134 at the time it is inserted into the electronic document 130 using the keypad 112 .
[0044] After the electronic document 120 is tagged, it may be stored in the database 102 . As previously discussed, instead of storing the tagged electronic document 136 in the database 102 , the tagged electronic document 136 may be transmitted to another location.
[0045] Exemplary Scanner
[0046] [0046]FIG. 3 is a block diagram of an exemplary scanner 300 constructed in accordance with an implementation of the present invention. The scanner 300 is shown in conjunction with a database 302 , though the database 302 is optional. A paper document 304 is shown for input into the scanner 300 .
[0047] The scanner 300 includes a processor 306 and an input/output (I/O) module 308 that handles transfer of electronic data to and from the scanner 300 . The scanner 300 also includes a touch-sensitive display 310 that is responsive to touch inputs from a user, a keypad 312 through which character data can be entered into the document processing system 300 , and a scan mechanism 314 that is used to scan the paper document 304 .
[0048] The scanner 300 includes memory 316 , which stores electronic data, including an operating system 317 that controls the function of the scanner 300 . A document input module 318 is stored in the memory 316 and is configured to receive an electronic document 320 from the scan mechanism 314 . An interface module 322 is stored in the memory 316 and presents the electronic document 320 on the display 310 .
[0049] The memory 316 also stores a stylus driver 324 that controls commands and data received from and sent to a stylus 326 . The stylus 326 is used in conjunction with the touch-sensitive display 310 , which is responsive to indications made with the stylus 326 .
[0050] A computational algorithm module 327 is also included in the memory 316 . The computational algorithm module 327 may be used to automatically determine portions of one or more documents to be scanned. The computational algorithm module 127 may be programmed to apply a context sensitive algorithm to a scanned document or a set of scanned documents. Some examples of such algorithms include, but are not limited to, detecting and selecting particular background color detection, locating and selecting text only regions as opposed to pictures, locating and selecting meaningful symbols or shapes, locating and selecting barcodes, locating and selecting patterns invisible to the naked eye, etc.
[0051] A document output module 328 is stored in the memory 316 and is configured to output selected portions of the electronic document 320 to the database 302 . It is noted that, in the present example, that the database 302 is optional. The database 302 may not be required if the electronic document 320 has some other destination, such as removable magnetic media, a network, etc. In the following discussion, those skilled in the art will recognize that different embodiments of the invention may be implemented depending on the document processing that is required.
[0052] A metadata tag insertion module 330 is stored in the memory 316 and is configured to insert a metadata tag 332 into the electronic document 320 to create a tagged electronic document 336 by allowing a position to be indicated with the stylus 326 and receiving input from the keypad 312 to define the metadata tag 332 .
[0053] The paper document 304 is processed by the scanner 300 to create the electronic document 320 . Alternatively, the electronic document 320 may be input to the scanner 300 in an electronic format via the communications module I/O module 308 . Once the electronic document 320 has been received by the document input module 318 , the interface module 322 displays at least a portion of the electronic document 320 on the touch-sensitive display 310 . Typically, the portion of the electronic document 320 displayed will be one page of the electronic document 320 , the page size depending on the size of the display.
[0054] The stylus 326 is utilized to indicate a position in the electronic document 320 , for example, for a cursor location. After the metadata tag 334 is defined and inserted into the electronic document 320 , it may be stored separately as the tagged electronic document 336 . The tagged electronic document 336 will typically be in the form of the electronic document 320 with the additional metadata contained in the metadata tag 334 .
[0055] When the tagging process is complete, the tagged electronic document 336 may be transmitted to another location. In the present example, the document output module 328 prepares the tagged electronic document 336 for transmission. As previously stated, the electronic document 320 may be stored in the database 302 or sent to another location over a network, stored on removable magnetic media, etc.
[0056] Methodological Implementation: Scanner
[0057] [0057]FIG. 4 is a flow diagram depicting a methodological implementation of the exemplary scanner 300 shown in FIG. 3. Continuing reference will be made to the elements and reference numerals of FIG. 3 in the following discussion of FIG. 4.
[0058] At block 400 , a document is scanned to create an electronic document. Alternatively, the electronic document 320 may be input to the scanner 300 in an electronic format via the I/O module 308 . At block 401 , a multi-pass image analysis is performed wherein one or more portions of the electronic document 320 are selected. The multi-pass image analysis 401 , using the computational algorithm module 327 , identifies and selects one or more portions of the document for metadata tag augmentation and population. This process can be accomplished manually in Block 402 , display and preview of document, or the entire document may be processed requiring no computation algorithms of this type.
[0059] Once the electronic document 320 has been received by the scanner 300 , the interface module 322 displays at least a portion of the electronic document 320 —a document preview—on the touch-sensitive display 310 at block 402 . Typically, the portion of the electronic document 320 displayed will be one page of the electronic document 320 , the page size depending on the size of the display.
[0060] At block 404 , a decision is made whether a metadata tag 334 needs to be inserted into the electronic document 320 . If no metadata tag 334 is required (“No” branch, block 404 ), then the document is stored (or transferred) at block 412 . If a metadata tag 334 should be inserted into the electronic document 320 (“Yes” branch, block 404 ), then the process continues at block 406 .
[0061] At block 406 , a location for the metadata tag 334 is identified using the stylus 326 . The keypad 312 is used to enter data to define the metadata tag 334 at block 408 . At block 410 , the metadata tag 334 is inserted into the electronic document 320 to create the tagged electronic document 336 .
[0062] After the electronic document 320 is tagged, it may be stored in the database 302 . As previously discussed, instead of storing the tagged electronic document 336 in the database 302 , the tagged electronic document 336 may be transmitted to another location, that is, a workflow or some variation of a process pipeline.
[0063] Conclusion
[0064] Implementation of the systems and methods described herein provide efficient ways for inserting metadata tags into electronic documents. While paper documents are being scanned so they can be archived, metadata tags that describe the data contained in the document may be entered into the document. Thereafter, searching documents and other document processing is made more efficient by using the metadata tags.
[0065] Although the invention has been described in language specific to structural features and/or methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or steps described. Rather, the specific features and steps are disclosed as preferred forms of implementing the claimed invention. | Systems and methods are described herein for scanning a paper document to create an electronic document that is displayed to allow one or more metadata tags to be inserted in the electronic document. Each metadata tag contains metadata that describes the contents of the document. Large volumes of documents can be archived so that a quick search of the documents may be accomplished by searching the metadata tags contained in the documents. The systems and methods described provide a fast and efficient way to enter metadata tags into documents as paper documents are converted to electronic documents. In at least one implementation, computational algorithms may be used to identify specific portions of a document for selective processing and storage. | 6 |
INTRODUCTION
[0001] This invention relates to a method and system for providing Live TV and or video-on-demand content to a plurality of content viewers' devices, the content viewers' devices having a plurality of disparate content viewing applications thereon.
[0002] Throughout this specification, the terms content viewer's devices, user devices and variants thereof have been used interchangeably and will be understood to include mobile telephones and Internet enabled devices such as but not limited to personal computers, smartphones, smart TV devices, laptops, computing tablets such as iPads (Registered Trade Mark (®™)) and the like.
[0003] As content viewer's devices have become more technologically advanced and their processing capability has increased, they are increasingly being used for viewing video-on-demand content. Typically, the video-on-demand content clip is sent from a content provider to a content server. The content server encodes the clip into a streaming format suitable for distribution to user devices and the content viewer's device thereafter downloads or streams the clip the clip in the viewing format to view on their user device. However, due to the large number of user device manufacturers and the variety of user device handsets, there are numerous different types of content viewing applications, not all of which are compatible with the streaming format provided by the content server.
[0004] In order to overcome this problem, the content server will usually encode the content clip into a plurality of different streaming formats that are suitable for a range of user devices. The content viewer's device users are then able to download the clip in the streaming format compatible with the content viewing application on their user device. In this way, the content will be accessible to a far wider audience. There are however several problems with the known methods and systems.
[0005] First of all, video-on-demand content clips are often relatively large in size, typically between 1 to 2 gigabytes (Gb) in size for a few minutes of regular viewing. The content clips can be even larger in formats such as high definition that are currently available. The content provider has to upload the clip from their computer to the content server. This upload can take a significant period of time, often in excess of 15 minutes to complete. Secondly, this lengthy transfer of the large content clip requires a significant amount of bandwidth to perform and is therefore usually expensive to do. Thirdly, a substantial amount of expensive equipment is required at the content server as the content server must store the original copy of each content clip received from the content provider as well as copies of the content clip in all of the encoded streaming formats.
[0006] Finally, in addition to the above, there is a further problem in that it often takes a significant length of time for a clip to be encoded and made available to content viewer's device users as backlogs often arise at the content server. It is not uncommon for a clip to take 24 hours before it is made available to the users. This is highly disadvantageous in many instances particularly those where the content clip is news or current affairs related. A significant delay can result in the content clip being rendered irrelevant or out-dated.
[0007] It is an object of the present invention to provide a method and system that overcome at least some of the above-mentioned problems.
STATEMENT OF INVENTION
[0008] According to the invention there is provided a method of providing Live TV or video-on-demand content available for distribution to a plurality of content viewers' devices, the content viewers' devices having a plurality of disparate content viewing applications thereon, in a system comprising:
a content provider computer operated by a content provider; and a content server accessible by the content provider computer over a data communications network and accessible by the content viewers' devices over one of the data communications network and a mobile telecommunications network, the content server having accessible memory, the method comprising the steps of: storing content on the content provider computer; the content provider computer accessing a webpage hosted by the content server, the web page having a plurality of content encoders embedded therein; the content provider computer selecting the content for distribution and thereafter encoding the content into a plurality of streaming formats using the plurality of content encoders and uploading the content in the plurality of streaming formats to the content server; storing the content in the plurality of streaming formats on the content server's accessible memory; and updating at least one of a web page and a wireless application protocol (WAP) page accessible by the content viewers' devices with a link to access the uploaded content.
[0016] By having such a method, all encoding of the content will be performed not on the content server but instead will be performed on the content provider computer. This will reduce the size of the files being transferred from the content provider computer significantly, often by a factor of 100 times or more, thereby reducing the time taken to transfer the files to the content server and reducing the bandwidth requirement. In addition to the above, the equipment requirement and cost at the content server will be significantly reduced as the large original content clip is no longer provided to the content server and the content server does not require expensive hardware encoders to encode the clips. Furthermore, the encoded content will be available to the user devices far quicker than was heretofore the case as the content clip will not have to wait to be encoded into several different streaming formats by the content server. Instead, the content will be made available to user devices in multiple streaming formats almost instantaneously. In addition to the above, the content provider will be able to keep the original content in-house and the original content will not be located remotely out of their control.
[0017] A significant advantage of the present invention results from the manner in which the plurality of encoders is embedded into a web page. By embedding the encoders into a web page, the content provider will not have to download various software applications for encoding the software onto their computer and the encoding is all done through the web page. The content will be encoded into a plurality of streaming formats and uploaded to the content server in a single unitary action and the content provider will not have to perform multiple encoding and uploading operations, one for each of the different streaming formats that it wishes to provide the content in, or indeed separate encoding and uploading actions for each streaming format. In this way, the process is highly automated. Furthermore, as specialised software is not required on the content provider computer, the content provider can upload content from any computer that has web access. This is seen as particularly beneficial as content providers will be able to upload content from any device capable of storing the content and accessing the web page.
[0018] In one embodiment of the invention there is provided a method comprising the preliminary step of providing a web page tailored specifically to the content provider with the plurality of encoders embedded therein pre-selected according to a content provider's specification. In this way, the content provider can determine which streaming formats it wishes to support and can choose a wide range of content viewing applications that its content can be viewed with.
[0019] In one embodiment of the invention there is provided a method in which the content server hosts a plurality of web pages each having a plurality of encoders embedded therein and the step of the content provider computer accessing a web page hosted by the content server further comprises the content provider computer accessing the web page tailored specifically for the content provider.
[0020] In one embodiment of the invention there is provided a method in which the web page comprises a plurality of web page components and the method comprises the initial step of embedding only one encoder in any given component. This is seen as a particularly beneficial aspect of the present invention. Generally speaking, it is not possible to place multiple encoders into a single web page and have each of those multiple encoders encode a particular content file in a single unitary operation as the multiple encoders will conflict and stall. Advantageously, by placing only one encoder into any given component, the encoders will not conflict with each other.
[0021] In one embodiment of the invention there is provided a method in which the web page comprises a web page component and the method comprises the initial step of programming a plurality of encoders in a sequential manner into a single component so that the encoders are called in a predetermined sequence. This is seen as a useful alternative to placing only a single encoder into a given component and reduces the number of components required.
[0022] In order to achieve this, the code could be provided with a sequence in one script. The script would make exact determinations on the process along with some “whatIf” type statements to check what is about to be done before doing it. This is similar to running a batch script, with a command saying if something isn't there, skip it. According to the present invention, a check is performed to see if a particular encoder is present, and then start that encoder first before starting the remaining encoders.
[0023] In one embodiment of the invention there is provided a method in which prior to encoding the content into a plurality of streaming formats, the method comprises the step of determining whether there is a Windows (®™)-based encoder embedded in the web page and, if present, starting encoding with the Windows (®™)-based encoder before encoding with the other encoders.
[0024] In one embodiment of the invention there is provided a method comprising the additional step of establishing a private secure network connection between the content provider computer and the content server. By establishing a private secure network connection through the internet, it will be possible to upload the encoded content in streaming format from the content provider to the content server in a fast, secure manner and the encoded content can be uploaded to the content server as the content is being encoded.
[0025] In one embodiment of the invention there is provided a method comprising the step of uploading the encoded content in streaming format immediately as it is encoded. This reduces the time taken to complete the encoding and uploading operation thereby further reducing the time required to upload content to the content server and make it available to the user devices.
[0026] In one embodiment of the invention there is provided a system for providing video-on-demand content to a plurality of content viewers' devices, the content viewers' devices having a plurality of disparate content viewing applications thereon, the system comprising:
a content provider computer operated by a content provider, the content provider computer having a web browser; a content server accessible by the content provider computer over a data communications network and accessible by the content viewers' devices over one of the data communications network and a mobile telecommunications network; a web page hosted by the content server and accessible by the content provider computer, the web page having embedded therein a plurality of encoders for encoding content into a plurality of streaming formats and uploading the content in the plurality of streaming formats from a content provider computer to the content server; the content server having accessible memory for storage of the content in the plurality of streaming formats; and the content server hosting at least one of a web page and a WAP page accessible by the content viewers' devices with a link to access the uploaded content thereon.
[0032] This is seen as a particularly useful and efficient, yet simple, system to use to provide content in multiple streaming formats to user devices with a plurality of disparate content viewing applications. Such a system reduces the infrastructure cost significantly and furthermore will enable content to be made available to user devices faster than was heretofore the case.
[0033] In one embodiment of the invention there is provided a system in which the content server hosts a plurality of web pages each having a plurality of encoders embedded therein.
[0034] In one embodiment of the invention there is provided a system in which each web page is tailored specifically to one of the content providers with the plurality of encoders embedded therein pre-selected according to that content provider's specification.
[0035] In one embodiment of the invention there is provided a system in which the web page comprises a plurality of web page components, each component having only one encoder embedded therein.
[0036] In one embodiment of the invention there is provided a system in which the web page comprises a web page component and there is provided a plurality of encoders programmed in a sequential manner into the web page component.
[0037] In one embodiment of the invention there is provided a system comprising a private secure network connection between the content provider computer and the content server.
[0038] In one embodiment of the invention there is provided a system in which one of the content provider computer and the content server is located locally and the other of the content provider computer and the content server is located remotely.
DETAILED DESCRIPTION OF THE INVENTION
[0039] The invention will now be more clearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings, in which:
[0040] FIG. 1 is a diagrammatic representation of a system for providing video-on-demand content known in the art;
[0041] FIG. 2 is a diagrammatic representation of a system for providing video-on-demand content according to the invention;
[0042] FIG. 3 is a screen shot of a web page used to implement the present invention;
[0043] FIG. 4 is a screen shot of another web page used to implement the present invention;
[0044] FIG. 5 is a block diagram of a web page illustrating the layout of the web page according to a first embodiment of the present invention;
[0045] FIG. 6 is a block diagram of a web page illustrating the layout of the web page according to a second embodiment of the present invention; and
[0046] FIG. 7 is a screen shot of an administration web page used to implement the present invention.
[0047] Referring to FIG. 1 , there is shown a diagrammatic representation of a system for providing video on demand content already known in the art, indicated generally by the reference numeral 1 . The system comprises a content provider computer 2 and a content server, indicated generally by the reference numeral 3 . The content provider computer 2 communicates with the content server 3 over a data communications network, illustrated here by the internet 11 . The content server 3 in turn further comprises a content server processor and temporary storage 5 , an encoder bank 7 having a plurality of encoders and a memory 9 . There is further shown a plurality of mobile telephones 13 , 15 , 17 in communication with the content server 3 over a mobile telecommunications network 19 . For simplicity, only three mobile telephones have been shown however it will be understood that there may be several more user devices in communication with the content server.
[0048] In use, a content provider uploads content from their content provider computer 2 to the content server 3 over the internet 11 . The content is a video clip and typically will be relatively large in size, of the order of 1 to 2 Gb. The time taken to upload the clip varies depending on the speed of the internet connection but it is not uncommon for the clip to take in the region of 15 minutes to upload with relatively good internet connection speed. Once uploaded, the content is stored in content server processor and temporary storage 5 until such time that the encoder bank 7 is in a position to receive the content. In some instances, due to the fact that the encoder bank will receive several content clips from that content provider and a plurality of other content providers (not shown), there will be a backlog and the content clip is not sent to the encoder bank 7 for an extended period of time, possibly for several hours.
[0049] When the encoder bank 7 is ready to receive the content, the content is passed through the plurality of encoders in the encoder bank 7 , each of which converts the content into a different streaming format, and the streaming format versions of the content are stored in memory 9 , ready for distribution to the mobile telephones 13 , 15 , 17 . A link is inserted on a web and a WAP page accessible by the mobile telephones to allow access to the content. When one of the mobile telephones requests content from the content server 3 , the content in the appropriate streaming format for that requesting mobile telephone's content viewing application is retrieved from memory 9 and transmitted to the mobile telephone over the mobile telecommunications network 19 .
[0050] Referring to FIG. 2 of the drawings, there is shown a diagrammatic representation of a system for providing video-on-demand content available for distribution to a plurality of content viewers' devices according to the invention, indicated generally by the reference numeral 21 , where like parts have been given the same reference numeral as before. The system comprises a content provider computer 22 having accessible memory 29 , in communication with a content server 23 over a data communications network 11 . The content server 23 comprises a content server processor and web server 25 and an accessible memory 27 . The content server processor and web server 25 hosts a web page (not shown) having a plurality of encoders embedded therein. There is further shown a plurality of user devices, in this case represented by mobile telephones 13 , 15 , 17 in communication with the content server 3 over a mobile telecommunications network 19 . For simplicity, only three mobile telephones 13 , 15 , 17 have been shown however it will be understood that there will be many more mobile telephones, perhaps tens or hundreds of thousands of mobile telephones in communication with the content server. Indeed, it will be understood that many other types of user devices could be in communication with the content server 23 over the mobile telecommunications network 19 or the data communications network 11 .
[0051] The content server 23 will also preferably include a WAP server (not shown) for servicing streaming format content requests from mobile telephone's and may include a second web server (not shown) for servicing streaming format content requests received over the internet 11 from other computing devices (not shown) such as, but not limited to, personal computers (PCs), laptops, tablets, iPads (Registered Trade Mark (®™)), think pads, smart phones, iPhones (®™) and the like computing devices that can communicate over the internet 11 as opposed to the mobile telecommunications network 19 . Alternatively, the content server processor and web server 25 could handle communications with both the content providers and the other computing devices. Content server 23 , will include a WAP server and in some cases a web server and in other cases an applications server. The content provider will be able to upload content via the internet or a telecoms network. The end user will also be able to view the latest content over the internet or over the telecommunications network.
[0052] In use, an operator of the content provider computer 22 accesses the web page with the plurality of encoders embedded therein hosted by the content server processor and web server 25 . Preferably, this is done over a private secure network connection between the content provider computer 22 and the content server 23 . Once the web page with the plurality of encoders embedded therein is rendered on the content provider computer 22 , the operator of the content provider computer 22 selects a content clip stored in accessible memory 29 and inserts the details of the content clip into the web page. The web page thereafter retrieves the content clip from accessible memory 29 and provides the content clip to the encoders embedded in the web page.
[0053] The plurality of encoders embedded in the web page encode the content into a plurality of streaming formats and simultaneously upload the content in the plurality of streaming formats to the content server 23 . The content server 23 stores the content in accessible memory 27 ready for distribution to the user devices, in this case the mobile telephones 13 , 15 , 17 . A link is created by the content server processor and web server 25 and inserted on at least one of a web and a WAP page to allow access to the content by the plurality of user devices 13 , 15 , 17 . When one of the user devices requests content from the content server 3 , the content in the appropriate streaming format for that requesting user device's content viewing application is retrieved from memory 27 and transmitted to the mobile telephone over the mobile telecommunications network 19 .
[0054] Technically speaking, the software is embedded in the page, similar to the manner in which a java script might be embedded into a page showing a real time clock. The software is an application in which the code is embedded into a page to make it easier to access without having to download multiple applications and learn how to use them.
[0055] The content is available practically instantaneously to the mobile telephones due to the fact that the content is already in a plurality of streaming formats prior to reaching the content server 23 and the content does not have to await encoding. Furthermore, the encoded content will be a fraction of the size of the original content clip, usually of the order of a few megabytes (Mb) in size, and is uploaded far quicker than with the prior art system. This speeds up the delivery of the content to the mobile telephones. Advantageously, a copy of the original content clip in un-encoded format does not have to be stored in the content server's accessible memory 27 .
[0056] It is envisaged that there will be several content providers in communication with the content server, however for reasons of simplicity, only one of which has been shown in the present embodiment. Therefore, it is envisaged that there will be several web pages, each of which is specific to a given content provider. The content provider can access their web page and upload content in the streaming formats desired by them into a location desired by them also. Furthermore, it is envisaged that a content provider, per se, may in fact comprise a number of contributors operating on one or more content provider computers but are grouped together as a single content provider. For example, a content provider may be an institution such as The British Broadcasting Corporation (BBC) (®™) television station and a plurality of the television station's personnel, for example their news reporters, would have access to the BBC's web page hosted by the content server 23 for encoding and uploading content. Any of the reporters, using any computer with a web browser and an Internet connection, could access the BBC's web page hosted by the content server 23 and encode and upload content in streaming formats to the content server 23 .
[0057] It can be seen therefore from the foregoing that content can be uploaded from any of the reporters using their own browser on their content provider computer 22 and from the content in their content provider computer's memory 29 . The content could come directly from a video camera (not shown) or the like that is connected to a network which in turn connects the video camera to the content provider computer 22 or the video camera could be connected directly to the content provider computer 22 via a cable or other link.
[0058] In the embodiment shown, the system and methods determine the type of user device that is being used. In this way, when a user logs in, the method and system according to the present invention recognize what device type of user device it is, such as a mobile telephone, PC or Smart TV and the appropriate content format is provided to them.
[0059] Referring now to FIGS. 3 and 4 , there are shown representations of the web page for use by the content provider and hosted by the content server. Referring specifically to FIG. 3 , after the content provider has logged in to the web page, preferably using a username and a robust password, the web page 31 shown in FIG. 3 will be rendered on their content provider computer 22 screen. The web page 31 comprises a File field 33 , an Upload button 34 , a Title field 35 , a Description field 36 , a Tags field 37 and a Save button 38 . It is envisaged that additional functionality will be added to this page such as value, duration, additional copyright, location for use, genre, age limit and the like.
[0060] The File field 33 allows the content provider computer to select a file stored on the hard drive or on a memory device connected to the computer. The user can type in the file name and location or can search using commonly known search tools used to search for a file in a computer system. Once selected, the user inserts a title of the content in the Title field 35 , a description of the content in the Description field 36 and several tags for the content in the Tags field 37 . Tags are identifier words used to assist in searching for content and are well understood in the art. If the user wishes to encode and upload the content, they select or click on the Upload button 34 in the known manner, for example by using a pointing device such as a mouse and clicking the mouse button when a mouse cursor is over the Upload button 34 . This causes the screen to be updated to the screen shown in FIG. 4 . Alternatively, the user can click on the Save button 38 and the session will be saved in memory on either the content provider computer's accessible memory 29 or as a session on the content servers accessible memory 27 .
[0061] Referring specifically to FIG. 4 , there is shown a web page, indicated by the reference numeral 41 . The web page has a number of fields 42 , 43 , 44 , 45 , 46 that allow the user specify the location of the content on their Web and WAP pages that are accessible by content viewers using web accessible devices and mobile telephones. Once the user has selected the location of the file in their content offering, the user clicks on the upload button 47 and the file is encoded into a plurality of streaming formats and simultaneously uploaded to the content server's accessible memory 27 and the links to the content are inserted in the desired, specified locations.
[0062] Referring to FIG. 5 , there is shown a block diagram of a web page 51 , illustrating the format of the web page according to a first embodiment of the present invention. The web page 51 comprises a plurality of web page components, 52 , 53 , 54 , 55 and 56 . There are further provided a plurality of encoders, 57 , 58 , 59 , 60 and 61 . It will be noted that there is only one encoder in each of the components. In this way, the encoders do not have a tendency to conflict with each other. By clicking on the upload button as previously shown in FIG. 4 , the content is accessed by each of the encoders as each of the encoders is called in turn through a call to their component. In the embodiment shown, only five encoders are used however it will be understood that several more or less encoders could be provided depending on the content provider's requirements. If a Windows-Based Encoder (®™) is present as one of the encoders, 57 , 58 , 59 , 60 , 61 , it is invoked before any of the other encoders to prevent conflict between the encoders. The functions are all hidden from the user as indeed are the pages. In the example of FIG. 5 , there are effectively 5 pages embedded in one page. By pressing the Upload Button in FIG. 3 , the encoding of the content is invoked.
[0063] Referring to FIG. 6 , there is shown a block diagram of a web page illustrating the content of the web page according to a second embodiment of the present invention, indicated generally by the reference numeral 71 . The web page 71 comprises a plurality of web page components, 72 , 73 , 74 , 75 and 76 . There are further provided a plurality of encoders, 77 , 78 , 79 , 80 and 81 . In this embodiment, there is provided a plurality of encoders in a single component 76 . The plurality of encoders are programmed in a sequential manner into the web page component 76 so that they do not conflict with each other. If a Windows-Based encoder such as Windows Media Player is present as one of the encoders, 77 , 78 , 79 , 80 , 81 , it is invoked before any of the other encoders to prevent conflict between the encoders. In the embodiment shown, only five encoders are used however it will be understood that several more or less encoders could be provided depending on the content provider's requirements.
[0064] It will be understood that the content providers will be able to specify the types of encoders that they wish to have in their web page during an initial web page construction phase. For example, the web page may have a template of components and encoders and the content provider can decide that they wish to support all available streaming formats in which case all of the encoders will be embedded in the web page. Alternatively, if they do not wish to support all formats they may pick and choose which encoder types that they wish to support and only have those encoders embedded in the web page. The unwanted components and/or the encoders can be removed with ease from the web page without having a detrimental effect on the remaining web page code.
[0065] Referring to FIG. 7 , there is shown a screen shot 91 of an administration web page used to implement the present invention. The administration web page has a plurality of sections including an encoding engine menu 93 and an updating settings menu 95 . The encoding engine menu 93 provides a list of the functionality and viewing formats that the content provider may use and update including general uploading settings, 3GP settings, MPEG-4 settings, WMV settings, Flash Settings and Content Provider (CP) login.
[0066] The content of the updating settings menu 95 is presented depending on the selection chosen by the user from the encoding engine menu 93 . In the embodiment shown, the user has selected the uploading settings icon from the encoding engine menu 93 and a plurality of sections 97 , 98 , 99 are provided in the updating settings menu 95 that relate to the uploading settings profile of the content provider. The sections 97 , 98 , 99 include a CP detail section 97 which contains information about the content provider including their ID, the upload limit size, the content providers location, the content provider's uploaded directory address and the content providers uploaded image directory address. CP permissions section 98 includes the list of content formats with check-boxes to indicate which of the content formats the CP is currently able to provide to their customers. In the embodiment shown, the content provider is able to provide content in 3GP and FLV file formats. CP Tags section 99 contains a list of the various tags under which the content provider can display their content.
[0067] If one of the other icons is selected from the encoding engine menu, such as the 3GP settings menu, the various settings for 3GP uploads will be provided, such as, but not limited to, the content provider ID, the output extension, the audio sampling rate, the size, the audio bit rate, the frame rate for EDGE, the bit rate for 3G, the bit rate for GPRS, the video CODEC, the audio channel, the audio CODEC, the buffer size, the frame rate for 3G, the frame rate for GPRS and the bit rate for EDGE. In addition to these options, it is envisaged that there will be provided an “apply” button and a “cancel” button to accept or reject respectively any proposed changes to the settings made by the user during the session. Similar options will be provided for each of the other icons in the encoding engine menu 93 .
[0068] It will be understood that the web page is hosted on the content server, although in principal, this could also be a standalone offering on a separate machine and only be used for encoding, security and dictating where the content will end up being stored or hosted depending on the content provider's wishes. Furthermore, it will be understood that in addition to trying to run multiple encoders from one page, there would also be inherent difficulties in running multiple applications at the same time if the user had downloaded and installed the encoder applications all on the local computer. There is also the fact of in some instances if a machine was setup in a certain way, whereas the user could potentially run multiple media applications simultaneously, they may have the additional issue of accessing the same file at the same time by these applications. Accordingly, the present invention overcomes such problems also.
[0069] In certain circumstances, a particular “work start” process may have to be put in place. There are certain scenarios where different encoding format processes must be started before other ones in order to avoid conflict. This is common particularly on windows based systems.
[0070] It will be appreciated that there are a number of additional elements and advantageous aspects to the present invention. First of all, the present invention comprises an administration tool that allows new content providers to be added in a seamless fashion. This includes providing a secure link, a selection of data sections to add to the content being uploaded, a selection of formats to be used depending on the receptive audience, the amount of content sections to be included and the like. Secondly, the administration tool will generate both the content provider page and an end viewer set of pages for different device types. This is achieved without significant user interaction and is a highly automated process.
[0071] It will be further understood that the method according to the present invention will be performed largely in software and therefore the present invention extends also to computer programs, on or in a carrier, comprising program instructions for causing a computer to carry out steps of the method, in particular the encoding and uploading steps. The computer program may be in source code format, object code format or a format intermediate source code and object code. The computer program may be stored on or in a carrier, in other words a computer program product, including any computer readable medium, including but not limited to a floppy disc, a CD, a DVD, a memory stick, a tape, a RAM, a ROM, a PROM, an EPROM or a hardware circuit. In certain circumstances, a transmissible carrier such as a carrier signal when transmitted either wirelessly and/or through wire and/or cable could carry the computer program in which cases the wire and/or cable constitute the carrier.
[0072] It will be further understood that the present invention may be performed on two, three or more machines with certain parts of the computer-implemented method being performed by one machine and other parts of the computer-implemented method being performed by another device. The devices may be part of a LAN, WLAN or could be connected together over a communications network including but not limited to the internet. Many of the method steps could be performed “in the cloud”, meaning that remotely located processing power may be utilised to process certain method steps of the present invention. Accordingly, it will be understood that many of the method steps may be performed remotely, by which it is meant that the method steps could be performed either on a separate machine in the same locality or jurisdiction or indeed on a separate machine or machines in several remote jurisdictions. For example, the content provider computer could be in a first jurisdiction whereas the content server could be in a second jurisdiction. Similarly, the content server processor and web server may be in one jurisdiction and the content server accessible memory could be in a second jurisdiction. The present invention and claims are intended to also cover those instances where the method is performed across two or more machines located in one or more jurisdictions and those situations where the parts of the system are spread out over one or more jurisdictions.
[0073] In this specification the terms “comprise, comprises, comprised and comprising” and the terms “include, includes, included and including” are all deemed totally interchangeable and should be afforded the widest possible interpretation.
[0074] The invention is in no way limited to the embodiment hereinbefore described but may be varied in both construction and detail within the scope of the specification. | This invention relates to a method and system for providing live television and video-on demand content to a plurality of content viewers' devices, the content viewers' devices having a plurality of disparate content viewing applications thereon. A content provider uploads content to a content server and the content server delivers that content in a streaming format upon request to the user devices. In order to upload the content, the content providers access a web page hosted by the content server with a plurality of encoders embedded into the web page. The content providers use the embedded encoders to convert the content into a plurality of streaming formats and upload the content to the content server in the streaming formats. This significantly speeds up the transfer of content to the content server, ensures that the content is made available to the user devices earlier, and obviates the need for additional expensive equipment at the content server. | 7 |
BACKGROUND OF THE INVENTION
Several thousands of years ago, the human species evolved from a hunting society in which food had to be captured and people constantly traveled in pursuit of food, to a farming society in which their nomadic existence ceased and settlement was made in areas of plentiful water or precipitation. At this time, the total number of humans which inhabited the earth was relatively low so that settlements could easily be made in favorable locations for the growing and production of food.
However, the worldwide population explosion of the last 200 years has forced people to inhabit areas which are less than hospitable for the production of food. Typically, farming communities have moved further and further away from a source of running water or precipitation in the form of rain and snow. Man, with his ingenuity, has compensated for this lack of natural water by producing many types of irrigation systems in which water is transported over a long distance through pipes, culverts, conduits or similar devices for the purpose of drip or area irrigation. Historically, these systems were rather crude since they did not allocate a specific amount of water to each plant or area based upon the needs of the crop or the amount of precipitation which had recently fallen in the area.
Consequently, a number of systems have been developed in which automatic irrigation and sprinkling systems water lawns and crops, based partly upon the amount of precipitation which has fallen on a particular area. Typical systems of this type are described in U.S. Pat. Nos. 2,776,860 issued to Griffis and 2,991,938 issued to Norcross. Both of these patents accumulate rain water in various containers and disable an irrigation solenoid valve until the water accumulated in these containers is eliminated. Specifically, the water accumulated in the Griffis patent is eliminated in a gradual nature, whereas the water accumulated in the Norcross container is eliminated in a series of discrete drain events. Therefore, if an irrigation event, i.e., the sprinkling of water in a large area or drip irrigation to a specific plant, is scheduled when water is still contained in the container, this irrigation event will be partially or completely cancelled. Although the systems do operate in a manner to save water or to prevent over-watering, these systems do not always operate in an efficacious manner, especially when several irrigation events are immediately proceeded by a rainfall.
SUMMARY OF THE INVENTION
The present invention overcomes the deficiencies in the prior art by providing a system in which a measure of rainfall is mechanically eliminated from the system, or an electronic counter having a value based upon the measured rainfall is decremented only during the irrigation event. In both situations, the present invention would adjust the water application time of an irrigation area in response to rain. In addition, the system would be calibrated in such a manner as to deduct the amount of scheduled application time such that the application area receives a predefined quantity of water regardless of whether the water is supplied by the irrigation system or by precipitation. In this manner, if all of the water would be mechanically eliminated from a water collection system or an electronic counter is decremented to indicate that all of the water has been evaporated or similarly eliminated, water would be provided for an irrigation event which has previously been scheduled. If an irrigation event has previously been scheduled but the present invention indicates that the electronic counter has not been sufficiently decremented, water would still be supplied to the event if it has been determined that during the course of this irrigation event, the electronic counter has been properly decremented.
The present invention accomplishes its result by utilizing one or more sprinklers, drip irrigation devices or similar means of introducing water to a specific area or crop, whereby the output of water for each source is controlled by a solenoid valve. Additionally, for purposes of clarity, the present invention will be primarily discussed with respect to decrementing the electronic counter.
A precipitation control device is connected to the electronic counter which is controlled by a controller module. Based upon the amount of water collected or sensed by a precipitation sensor, the electronic counter would be incremented in a stepwise manner. If, during a preprogrammed irrigation event, the counter exhibits a zero output, power would pass between a source of power and the solenoid valves associated with each water output source to properly irrigate the land. However, if the counter module exhibits a value greater than zero during this irrigation event, the power between the power source and the solenoid valves would be interrupted. During this irrigation event, if the output of the counter module is greater than 0, a properly calibrated alarm cycle would decrement the counter module at a proper rate. Therefore, the present invention would determine the proper length of time a previously scheduled irrigation event should proceed based upon the rainfall sensed by the system. The present invention would therefore insure that water is not wasted and that the crops are properly irrigated.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the present invention will become more apparent from the following more particular description of the preferred embodiment of the invention, as illustrated in the accompanying drawings.
FIG. 1 is a pictorial description of the present invention;
FIG. 2A is a front view of a tip bucket sensor;
FIG. 2B is a side view of a tip bucket sensor;
FIG. 3 is a block diagram of the system of the present invention;
FIG. 4 is a circuit diagram of the input module of the present invention;
FIG. 5 is a circuit diagram of the counter module of the present invention;
FIG. 6 is a functional design drawing of the controller of the present invention;
FIG. 7 is a circuit diagram of the controller of the present invention;
FIG. 8 is a circuit diagram of the alarm module of the present invention.
FIG. 9 is a circuit diagram of the output module of the present invention; and
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a pictorial illustration of the present invention 10 utilized to control water distribution to lawns or crops. Although various types of water distribution devices can be utilized, for illustrative purposes only, FIG. 1 shows the use of two sprinklers 24, 26 to distribute water over a particular area. A power supply 12 is used to supply power to the system. This power supply could be supplied from a 24 volt AC source or can be internal to the system. This power supply is conducted through what is denoted as the rain delay module 14. A water accumulation sensor, such as a tip bucket 16 is used to determine the amount of rainfall which has been received in a particular area. Generally, this water sensor is provided in a location which would not record the amount of water distributed by the sprinklers 24, 26. Information relating to the amount of precipitation sensed by the sensor 16 is transmitted to the rain delay module 14 via a typical electrical conductor 18. If it is determined that, based upon the amount of precipitation sensed by the sensor 16, a particular irrigation event should go on as scheduled, power to open solenoid valves 28, 30 associated with sprinklers 26 and 24 respectively, is sent from the rain delay module 14 via an electrical conductor 20. Water is to be supplied to sprinklers 24, 26 utilizing water hoses 32, 34, respectively. A standard tap faucet 36 is also used to control the supply of water to the sprinklers.
FIGS. 2A and 2B illustrate a typical tip bucket water sensor which can be utilized in conjunction with the present invention. This water sensor is described in some detail in U.S. Pat. No. 4,644,786 issued to Jacobsen et al. As previously indicated, the type of water sensor which is utilized is not crucial to the present invention and the tip bucket described in these drawings is for illustrative purposes only. As shown in these drawings, water is diverted into a tip bucket 40 through a funnel 38. This tip bucket is supported by a bushing fulcrum 42 connected to a stand 46 having a base 54. Tip angle limiters 44 are also connected to the stand 46 to limit the travel of the tip bucket 40. A rotating lever 48 provided with a magnet 50 at its bottom end is connected to the tip bucket 40. A reed switch 52, having conductors 18, is attached to the stand 46. When a predetermined amount of precipitation is received by the tip bucket 40, the tip bucket is caused to rotate downward allowing the magnet 50 of the lever 48 to pass in proximity to the reed switch 52, momentarily closing this normally opened switch. Each time this reed switch is closed, a signal is sent to the input module 56 shown in FIG. 3.
FIG. 3 depicts a system block diagram of the rain delay module 14 consisting of an input module 56, a counter module 58, a controller module 60, an alarm module 62, an output module 64 and a display module 66. The system is connected in series with the power source 12 required to activate the solenoid valves 28 and 30. The circuitry of this module 14 constantly monitors the power line and can determine if the activation power for these valves is present, thereby interrupting the flow of current before it reaches the solenoid valves 28, 30.
The purpose of the input module 56 is to interface the rain delay module with the external environment. The input module is provided with a tip bucket switch input, a reset switch input and the 24 volt alternating solenoid power of the host irrigation system. The output of this module contains three logical signals and a 5 volt DC power signal for the rain delay circuit board provided in the controller module 60.
FIG. 4 illustrates the input module circuitry and includes a push button switch 68 connected to the reed switch 52 of the tip bucket. Switch 68 is normally open except for the brief period when the tip bucket tips. Resistor 70, capacitor 72 and amplifiers 74 and 76 are used to monitor the status of switch 68. When this switch closes, the capacitor 72 and the two amplifiers 74, 76 de-bounce and condition a lower logical pulse which is transmitted to the counter module 58.
Push button switch 78 is used as a reset switch and it is normally open except for the brief period when the user depresses this switch. Resistor 80, capacitor 83 and amplifiers 84 and 86 are used to monitor the status of this switch 78. When this switch 78 closes, capacitor 82 and amplifiers 84, 86 de-bounce and condition a low logical pulse which is transmitted to both the counter module 58 and the controller module 60.
The input module 56 also includes a diode bridge 88 for converting the 24 volt AC host power supply into a filtered direct current voltage. Voltage regulator 96 and resistor 98 connected to the output of the diode bridge would produce a 5 volt direct current signal whenever the host solenoid power is present. The resistor 98 would hold the main power output signal at zero whenever the host solenoid power is not present. Whenever the host solenoid power is not present, a number of nickel-cadmium batteries 94 supply the power to the system. A voltage regulator 92 connected to the nickel-cadmium batteries are also used for this purpose. When the host solenoid power is present, the nickel-cadmium batteries 94 are recharged.
The counter module 58 receives tip as well as reset pulses from the input module 56 as well as a decrement pulse from the control module 60. The counter module produces a zero pulse transmitted to the controller module 60 as well as a count pulse transmitted to the display module 66. The purpose of the counter module is to determine, based upon the amount of precipitation sensed by the tip bucket 16 as well as a decrement schedule calibrated to match the water application area, to open the solenoid valves if water is required to be applied during an irrigation event. The counter module includes two mod-4 counters 100, 102 cascaded to form a single mod-8 counter. Whenever a low reset signal is received by the counter, the counter is immediately reset to zero. Whenever a low tip signal is sensed by the counter, it is immediately incremented by one. Whenever a low decrement signal is received by the counter, the counter is decremented by one. OR gates 104, 106, 108, 110, 112, 114 and 116 are used to form the logical sum of all eight counter bits. The final output is true (low), if, and only if, the counter is at zero. At this point, this zero signal is sent to the control module 60.
The control module 60 implements a Moore type finite state sequencer shown in FIG. 6. The controller maintains two state variables Y1 and Y2 having four unique states. The input to the controller module is an alarm signal from the alarm module 62 indicating the rate at which the counters 100, 102 are decremented as well as a signal from the counter module 58 indicating that the counter is at a zero level. Additionally, the control module receives a signal indicating that the main host solenoid power is present in the system. The control module produces a low decrement signal to the counter module 58, a low trigger signal to the alarm module 62 as well as a high ready signal to the output module 64.
The design of the controller module is illustrated with respect to FIG. 6. Initially, the system would reset to state 00 in which the low decrement and low trigger signals are false and the high ready signal is true. These outputs indicate that the tip counter should not be decremented, an alarm cycle should not be initiated and the host solenoid power should be passed uninterrupted. At this point, if the tip bucket tips, the tip counter is no longer at zero, and a low zero signal is false. If, at this point, the host solenoid power is activated (a high main signal is true), then the controller advances to state 01. In this state, the low decrement and high ready signals are false and the low alarm signal is true. These outputs would indicate that the tip counter should not be decremented, the alarm cycle should be initiated, and the host solenoid power should be interrupted.
The controller remains in state 01 until the alarm module is ready to begin a new alarm cycle or the tip counter becomes zero. When this occurs, the high alarm signal would be true and the controller would advance to state 11. In this state, low trigger signals as well as a high ready signal are all false. These outputs would indicate that the tip counter should not be decremented, an alarm cycle should not be initiated, and the host solenoid power should be interrupted.
The controller remains in state 11 until the alarm cycle is completed. When the alarm cycle terminates, i.e., a high alarm signal is false, the controller would advance to state 10. In state 10, a low trigger signal as well as a high ready signal are false and a low decrement signal is true. These outputs indicate that the tip counter should be decremented, the alarm cycle should not be initiated and the host solenoid power should be interrupted. The controller would then decrement the tip counter by one and immediately returns to state 00.
The actions of the controller are modeled by the finite state diagram shown in FIG. 6. The logical requirements of the controller are modeled with the K-map. With standard techniques, the K-map is used to obtain the state equations for the state variables Y1 and Y2 and the output equations for the output signals D, T and R (decrement, trigger and ready, respectively).
The circuitry of the control module is illustrated in FIG. 7 and would utilize AND gates 118, 120, 122, 124, 130, 134, 136 and 142 as well as OR gates 126, 128, 132 and 144 and amplifiers 138, 140 and 146 to implement the controller using standard feedback techniques. The layout of the circuit follows exactly from the state equations for Y1 (the output of AND gate 134) and Y2 (the output of AND gate 136) and the output equations for the high ready signal as well as the low decrement and trigger signals.
The alarm module 62 is utilized to calibrate the rain delay module 14 in such a manner as to decrement the counter module at a predetermined rate. The alarm module 62 implements an alarm clock with an adjustable one-shot circuit. The input to this module 62 from the control module 60 is a low trigger signal. The output from the alarm module 62 is a high alarm signal to the control module 60. The alarm module 62 includes a 555 timer 148 configured to act as a one-shot timer. When a low trigger signal is true, the timer 148 would begin to charge capacitor 156 at a rate determined by the adjustable resistor 152. The range of adjustment for this circuit could extend from approximately 60 to 600 seconds for a full charge. When the charge on capacitor 156 reaches approximately 2/3 its full charging voltage, the timer 148 would ground pin 7 and the capacitor 156 would discharge as rapidly as possible. The alarm module also includes a high impedance operational amplifier 158 configured as a Schmidt trigger. When the voltage across capacitor 156 exceeds approximately 1/3 its charging voltage, the operational amplifier 158 would produce a low voltage output, which is converted by amplifier 162 into a high alarm signal, indicating that an alarm cycle is transpiring. When the voltage across capacitor 156 falls below approximately 1/3 the charge in voltage, the output of operational amplifier 158 would produce a higher voltage and the amplifier 162 would indicate that the alarm module is ready to begin another alarm cycle.
The purpose of the output module 64 is to, either interrupt the flow of power to the solenoid valves 28, 30 to prevent water from irrigating a particular area, or to allow power to be transmitted to these valves, thereby allowing the area to be irrigated. A high ready signal is received by the output module 64 from the controller module 60 and a high main signal is received by the output module 64 from the input module 56. The circuit diagram of the output module 64 is illustrated in FIG. 9. This figure includes logical gates 164, 166 and 168 to form the logical product of the high ready signal and the high main signal. An amplifier 170, transistor 172 and relay 174 are used to actually switch the 24 volt alternating current solenoid power. Whenever the relay 174 is energized, the solenoid power circuit is closed. Therefore, it can be seen that only when both a high ready and high main signal are sent to the output module 64, would the relay 174 be energized and water supplied to an irrigated area.
The rain delay module 14 can also be provided with a display module 66 which would visually or aurally indicate the current status of the rain delay module 14. This module could also display information regarding the tip bucket count, the solenoid power status, the battery charge status as well as other information relating to the entire system.
Contrary to prior art automatic sprinkling or irrigation systems, the present invention operates by automatically decrementing a counter only during the time that an irrigation event is scheduled. Therefore, before the system according to the present invention becomes operational, an irrigation event schedule should be determined. This schedule would be predicated upon many variables, such as the type of crops or vegetation which must be watered, the type of soil, the time of day, and position of the sun, as well as a number of additional environmental considerations. This irrigation event schedule can be provided as an automatic or manual external input to the input module or can be implemented internally in the input module. In any of these situations, a high main output signal directed to the output module 64 would be present whenever such an event is scheduled. At this point, the controller module 60 would check the status of the tip bucket counter in the counter module 58. If the counter is set at zero, a ready signal is presented to the output module 64 which would allow the main power signal to pass uninterruptedly through the rain delay module to one or more of the solenoid controlled water supply systems. If the tip counter of the counter module 58 is greater than zero, a trigger signal is produced between the controller module 60 and the alarm module 62 which would allow the timer provided therein to begin to charge a capacitor. When the charge in this capacitor exceeds a particular level, an alarm signal would result between the alarm module 62 and the controller module 60, thereby producing a signal used to decrement the tip bucket counter in the counter module 58. It is important to note that this decrement cycle would only take place when a main power signal, indicating the presence of a scheduled irrigation event, through the input module is directed to the controller module. If this main power signal is not received by the controller module 60, the tip bucket counter in the counter module 58 would not be decremented. This system should be contrasted with the prior art systems in which precipitation collected in a container would be constantly or in a stepwise manner released from this container.
The rate at which the counter 100, 102 is decremented is calibrated to match the application area. This calibration is effected by requiring the duration of an alarm cycle to be determined by the adjustable resistor 152. The system is calibrated in units of seconds/tip. Each closure of the tip bucket switch 68 will disable the solenoid activation power for a specific amount of time. This calibration setting is determined by placing the tip bucket 16 such that it receives water from the irrigation system at the rate the water is normally applied. In this position, the number of seconds required to trigger the tip bucket is the correct calibration setting.
While the invention has been particularly shown and described in reference to the preferred embodiment thereof, it should be understood by those skilled in the art that the foregoing other changes in form and details may be made without departing from the spirit and scope of the invention. For example, although the rain delay device of the present invention as described herein is implemented utilizing an electronic counter, the present invention could operate utilizing a completely mechanical and electromechanical device. For example, a collection tube similar to the one described in U.S. Pat. No. 2,776,860 to Griffis could be modified by placing a solenoid valve just below the drip valve. If this solenoid valve were only open during a scheduled irrigation event, then the water could only drip out during this event. This system would provide functionality completely analogous to the present electronic implementation. | An automatic irrigation and sprinkling system for applying irrigation water or airborne dispersed water to a particular area. A precipitation sensor is included for incrementing a counter based upon the sensed precipitation. During a scheduled irrigation event, power is applied to the system to open one or more solenoid valves to control the flow of water. This main power signal would flow uninterruptedly to the solenoid valves only if the counter was at a predetermined value. A value greater than this predetermined value during a scheduled irrigation event would cause the power to be interrupted to the solenoid valves and would allow the counter to begin decrementing. If the value of the counter reaches this predetermined value during the scheduled irrigation event, power would again be supplied to the solenoid valves, thereby supplying water to the predetermined area. | 8 |
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure relates to a plastic product with three dimensional patterns and a manufacturing method of the plastic product.
[0003] 2. Description of Related Art
[0004] Plastic products are widely used. Some plastic products have decorative patterns thereon for artistry and beauty. Commonly, an In-Mold-Decoration (IMD) technology is developed to provide three dimensional patterns on the plastic products. The IMD technology incorporates a foil on which decorative patterns are printed. The foil is placed in a cavity bounded by molds. The cavity provides a relief pattern area on an inner surface. The decorative patterns adhere to the plastic product after the plastic product is molded and separated from the cavity, thus forming the three dimensional patterns on the plastic product. However, the three dimensional patterns are formed on an outer surface of the plastic product, and are easily worn away over time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0006] FIG. 1 is a flowchart of a method for manufacturing plastic products having three dimensional patterns in accordance with a first exemplary embodiment of the present disclosure.
[0007] FIG. 2 is a cross-sectional view of an apparatus for manufacturing plastic products utilizing the method of the first exemplary embodiment of FIG. 1 , before injecting resin.
[0008] FIG. 3 is similar to FIG. 2 , but showing a state of use after injecting resin.
[0009] FIG. 4 is a cross-sectional view of a plastic product manufactured by the apparatus of FIG. 2 .
[0010] FIG. 5 is a cross-sectional view of a plastic product of a second exemplary embodiment.
[0011] FIG. 6 is a cross-sectional view of a plastic product of a third exemplary embodiment.
[0012] FIG. 7 is a flow chart of a method for manufacturing plastic products having three dimensional patterns in accordance with a second exemplary embodiment of the present application.
[0013] FIG. 8 is a cross-sectional view of an apparatus manufactured by the method of FIG. 7 , before injecting resin.
DETAILED DESCRIPTION
[0014] The disclosure, including the accompanying drawings, is illustrated by way of examples and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0015] Referring to FIG. 1 and FIG. 2 , a method for manufacturing plastic products having three dimensional patterns in accordance with a first embodiment of the present disclosure includes the following steps.
[0016] Step S 402 , a mold 100 is provided to mold the plastic product, the mold 100 includes a female mold 101 and a male mold 102 mating with the female mold 101 .
[0017] Step S 404 , a first film 20 is provided to be attached to a bottom surface 103 of the cavity 104 of the female mold 101 . The first film 20 includes a bottom surface 201 facing the bottom surface 103 and a top surface 202 opposite to the bottom surface 201 . A first pattern 21 , a second pattern 22 , and a third pattern 23 are formed on the bottom surface 201 . A color layer 24 is printed on the bottom surface 201 around the second pattern 22 . A thickening layer 26 is attached to the first pattern 21 and faces towards the bottom surface 103 . The thickening layer 26 is printed with transparent ink. A thickening layer 28 is attached to the color layer 24 , facing the bottom surface 103 . A fourth pattern 27 is printed on the top surface 202 . In another embodiment, thickening layers can be attached to the second pattern 22 and the third pattern 23 . These thickening layers 26 and 28 may be of different thicknesses.
[0018] Step S 406 , a second film 30 is provided to be attached to the male mold 102 . A pattern 31 is printed on the second film 30 opposite to the male mold 102 .
[0019] Step S 408 , referring to FIG. 3 , molten resin is injected into the cavity 104 of the mold 100 , to press the first film 20 tightly against the bottom surface 103 . The first pattern 21 , the second pattern 22 , the third pattern 23 , the color layer 24 , and the thickening layer 26 and 28 are all tightly pressed so as to leave no gaps or bubbles on the bottom surface 201 of the first film 20 .
[0020] Step S 410 , referring to FIG. 4 , the molten resin in the mold 100 is cooled to form a plastic product 1 , with the first film 20 and the second film 30 attached to opposite sides (first and second sides 41 and 42 ) of the plastic product 1 .
[0021] The plastic product 1 includes a base 40 molded by injecting resin, a first attaching portion 20 a attached to the first side 41 of the base 40 , and a second attaching portion 30 a attached to the second side 42 of the base 40 . The first attaching portion 20 a is formed by the first film 20 of the FIG. 1 , formed in the mold 100 after injection. The plastic product 1 further includes a first pattern 21 a , a second pattern 22 a, a third pattern 23 a, and a color layer 24 a around the second pattern 22 a, all inserted into the first attaching portion 20 a. Two thickening portions 26 a and 28 a are respectively attached to the first pattern 21 a and the color layer 24 a. Based on the top surface 202 a of the first attaching portion 20 a, the first attaching portion 20 a includes a first protrusion 21 b according to the first pattern 21 a , a second protrusion 22 b according to the second pattern 22 a, a third protrusion 23 b according to the third pattern 23 a, a fourth protrusion 24 b according to the color layer 24 a, and a fourth pattern 27 a. The first to fourth protrusions 21 b, 22 b, 23 b, 24 b, the thickening portions 26 a and 28 a, and the fourth pattern 27 a are all inserted into the first side 41 of the base 40 .
[0022] The second attaching portion 30 a is formed by the second film 30 of the FIG. 1 being formed in the mold 100 after injection. The second attaching portion 30 a includes a fifth pattern 31 a facing the base 40 . The fifth pattern 31 a is inserted into the second side 42 of the base 40 .
[0023] The second attaching portion 30 a and the base 40 are made of transparent or semitransparent material. Thus the first pattern 21 a, the second pattern 22 a, the third pattern 23 a, the color layer 24 a, the fourth pattern 27 a, and the fifth pattern 31 a are visible through the second attaching portion 30 a and the base 40 as three dimensional patterns. The second pattern 22 a is shown as a sunken decoration according to the color layer 24 a. The first pattern 21 a and the fourth pattern 27 a are shown as protruding or relief decorations.
[0024] Referring to FIG. 5 , in a second embodiment of the present disclosure, the base 40 , the first attaching portion 20 a, and the second attaching portion 30 a of a plastic product 1 a are made of the same material(s), thus the interfaces between the base 40 , the first attaching portion 20 a, and the second attaching portion 30 a are not shown.
[0025] Referring to FIG. 6 , in a third embodiment of the present disclosure, a plastic product 1 b includes the base 40 and the first attaching portion 20 a.
[0026] Referring to FIG. 7 and FIG. 8 , a method for manufacturing the plastic product 1 b includes the following steps.
[0027] Step S 502 , a mold 100 is provided to mold the plastic product, the mold 100 includes a female mold 101 and a male mold 102 mating with the female mold 101 .
[0028] Step S 504 , a first film 20 is provided to be attached to a bottom surface 103 of the cavity 104 of the female mold 101 . The first film 20 includes a bottom surface 201 facing the bottom surface 103 and a top surface 202 opposite to the bottom surface 201 . A first pattern 21 , a second pattern 22 , and a third pattern 23 are formed on the bottom surface 201 . A color layer 24 is printed on the bottom surface 201 around the second pattern 22 . A thickening layer 26 is attached to the first pattern 21 , facing towards the bottom surface 103 . The thickening layer 26 is printed with transparent ink. A thickening layer 28 is attached to the color layer 24 , facing the bottom surface 103 . A fourth pattern 27 is printed on the top surface 202 .
[0029] Step S 506 , molten resin is injected into the molding 100 , to press the first film 20 tightly against the bottom surface 103 . The first pattern 21 , the second pattern 22 , the third pattern 23 , the color layer 24 , and the thickening layers 26 and 28 are all compressed tightly so as to leave no gaps or bubbles on the bottom surface 201 of the first film 20 .
[0030] Step S 508 , the molten resin in the mold 100 is cooled to form the plastic product 1 b , with the first film 20 being attached to one side of the plastic product 1 b.
[0031] Even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A plastic product having patterns in three dimensions includes an injecting base and a first film adhered to one side of the base. The first film includes a first pattern away from the base and a thickening layer attached to the first pattern. The first pattern is positioned between the thickening layer and the first film. A first raised portion is formed on the first film and inserted into the base. | 8 |
CROSS-REFERENCE OF RELATED APPLICATION
[0001] The present application claims priority from Korean Patent Application No. 2004-003555, filed on May 19, 2004, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a flexible circuit film.
[0004] 2. Description of the Related Art
[0005] A flexible printed circuit film (FPCF) has been used in cameras. These days, the flexible printed circuit film is used in computer hard disc drive, a floppy disk drives, a copy machines and a printer. Recently, the flexible printed circuit film is used in a liquid crystal displays (LCD) connecting a printed circuit board (PCB) to an LCD panel. As more products use the FPCF, the more commercially important the FPCF becomes.
[0006] An LCD panel comprises a thin film transistor (TFT) array substrate, a color filter (CF) substrate and a liquid crystal (LC) layer filled in a gap between the TFT array substrate and the CF substrate. The TFT array substrate comprises a gate line, a data line, a thin film transistor and a pixel electrode. The CF substrate comprises a color filter and a common electrode. A TFT is a switching element that transfers or blocks image signals according to the gate signals transferred through the gate lines. An image signals is transferred through the data lines. The gate lines receives gate signals from a gate driving integrated circuit (IC). The data lines receives data signals from a data driving IC.
[0007] The gate IC and the data IC are connected to the TFT substrate. One of methods connecting them is using a tape carrier package (TCP). Another method is a chip on glass (COG). The TCP attaches a circuit tape to the TFT substrate. The circuit tape carries a gate IC on it. The COG forms the gate IC directly on the TFT substrate.
[0008] The TCP is easy to produce and provides a high yield. The COG reduces the material costs and makes a slim and compact LCD. A control unit on a printed circuit board (PCB) generates signals to apply to the driving ICs through an FPCF.
[0009] Recently, electronic devices are smaller, lighter, and more integrated than they were. The FPCF needs to meet requirement for those devices. The FPCF should be attached well to electronic devices. The FPCF should have good thermal resistance. Furthermore, the signals transferred through the FPCF should not interfere each other.
[0010] Input end portion of the conventional FPCF has integrated wirings. Densely populated wires may twist among themselves, which may cause interference among the signal.
SUMMARY OF THE INVENTION
[0011] A FPCF comprises a flexible insulating film, a wiring pattern, an input end, an output end, and a connection portion that connects the input end and the output end. The connection portion is a film with a roughly rectangular shape. Thus the connection portion has a longitudinal direction and a transversal direction. First and second transversal wirings are formed at the input end. The first wirings are formed on a layer different from some of the second wirings. Third transversal wirings are formed on the same layer as the first transversal wirings and at the output end. In the connection portion, first longitudinal wirings are formed on a layer different from the first transversal wirings, and second longitudinal wirings that are electrically connected to the second transversal wirings are formed on a layer different from the first transversal wirings. The first transversal wirings and the third transversal wirings are crossing a portion of the first longitudinal wirings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows the whole area of a flexible printed circuit film and its wirings of one embodiment of the present invention.
[0013] FIG. 2 shows a portion of the wirings of an embodiment of the present invention.
[0014] FIG. 3 shows a portion of one layer of the embodiment of the FIG. 2 .
[0015] FIG. 4 shows a portion of another layer of the embodiment of the FIG. 2 .
[0016] FIG. 5 shows a portion of the wirings of an embodiment of the present invention.
[0017] FIG. 6 shows a portion of one layer of the embodiment of the FIG. 5 .
[0018] FIG. 7 shows a portion of another layer of the embodiment of the FIG. 5 .
[0019] FIG. 8 shows details of the center portion of the FPCF of an embodiment of the present invention.
[0020] FIG. 9 shows the wirings of one layer of the FPCF of the FIG. 8 .
[0021] FIG. 10 shows wirings of another layer of the FPCF of the FIG. 8 .
[0022] FIG. 11 shows the wirings of an end portion of the FPCF of an embodiment of the present invention.
[0023] FIG. 12 shows an example of an FPCF used in a TFT LCD.
[0024] FIG. 13 shows a cross-sectional view of X-X′ in FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] An FPCF comprises an insulation film, wirings attached to the insulation film with adhesive or without adhesive, and a cover film that covers the wirings for insulation.
[0026] An embodiment of the present invention provides an FPCF reducing interference among the signals transferring through the FPCF. One embodiment of the present invention provides two distinctive wirings printed on FPCF 10 , a longitudinal wiring 17 and a transversal wiring 15 . The two distinctive wirings are formed on different layers of the film. The longitudinal wirings 17 crosses over the transversal wiring 15 at substantially right angle 90°) in the connection portion of the FPCF. This minimizes interference of signals transferring through the wirings. An embodiment of the present invention also provides an FPCF whose wirings are not integrated in an input area.
[0027] The details of the present invention will be described hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
[0028] In FIG. 1 , the wirings of the FPCF are formed in a transversal direction at the input end, and connected to the longitudinal direction. The longitudinal wirings are connected to the transversal wirings in the output end.
[0029] FIG. 2 shows an FPCF of an embodiment of the present invention. Transversal wirings 15 are formed in the input portion 20 and the output portion 30 . Longitudinal wirings are formed in the connection portion. First transversal wirings run from an input end portion to the connection portion and are electrically coupled to the longitudinal wirings via holes 16 . The longitudinal wirings run to the longitudinal direction in the connection portion and electrically coupled to the second transversal wirings via holes 16 . The second transversal wirings run from the longitudinal wirings to an output end portion. The transversal wirings are formed on a different layer from the layer the longitudinal wirings are formed and substantially right angle from the longitudinal wirings, which minimizes interference among signals transferring through the FPCF. FIGS. 3 and 4 show that the transversal wirings are formed on one layer and the longitudinal wirings are formed on another layer.
[0030] FIGS. 5, 6 and 7 show another embodiment of the present invention. Some wiring may be better for interference being inclined from the transversal wirings than bending perpendicularly, especially when the bending area is far enough from other wirings.
[0031] As shown in FIGS. 8, 9 , 10 , 11 , and 13 , the transversal wirings ( 15 ) are formed in the input portion ( 20 ). The input portion wirings 15 can be grouped into two. First group of transversal wirings are located at the center of the input end portion, and extend straight in a transversal of the connection portion. Second group of transversal wirings position at both ends of the input end portion, and extend straight and later bent to a longitudinal direction at the connection portion. The first group of transversal wirings is electrically coupled to the longitudinal wirings via holes 16 .
[0032] As shown in FIGS. 9 and 10 , the first transversal wirings run from the center of the input end ( 20 ) to the first longitudinal wirings. A portion of the first transversal wirings run in a layer other than the layer that the other first transversal wirings run, which may be helpful to reduce the resistance in the ground electrode that is formed on the most portion of the layer. As shown in FIGS. 8 and 10 , the first longitudinal wirings position closer to the output end ( 30 ) than the input end ( 20 ).
[0033] As shown in FIG. 10 , the second transversal wirings are coupled directly to the second longitudinal wirings and are formed on the same layer as the layer that the second longitudinal wirings are formed on. The second transversal wirings are connected to the second longitudinal wirings by inclined wirings. Similar to the embodiment described above, if a wiring is far enough and don't affect other signals transferring other wirings, inclined wirings or curving wirings may be better than perpendicularly bending wirings for signal interference.
[0034] The majority of the transversal wirings are formed in the layer shown in FIG. 9 . The second transversal wirings, the inclined direction wirings, a portion of the first transversal wirings, first longitudinal wirings and the second longitudinal wirings are formed on the layer shown in FIG. 10 .
[0035] As shown in FIG. 9 , the first transversal wirings and the second transversal wirings are formed on one layer in the input end, which is convenient connecting to 6 uter wirings like PCBs.
[0036] FIGS. 2 and 5 show an output portion of the FPCF 10 . The first and the second longitudinal wirings are electrically connected to the input end 20 and the output end 30 by the transversal wirings. The wirings in the output end are third transversal wirings. The third transversal wirings are electrically coupled to the first and the second longitudinal wirings via holes. The third transversal wirings are formed on a layer different from the layer where the first and the second longitudinal wirings are formed. Thus the ground signal is not divided, and the wirings do not intersect one another. The ground electrode is formed in most areas except where the wirings are formed.
[0037] The above described structure of the present embodiment does not integrate the wirings and minimize interferences among wirings in the input portion 20 of the FPCF 10 .
[0038] FIG. 12 shows an example that the FPCF is used in a TFT LCD. It is a COG type LCD. The driving ICs 410 and 510 are attached on the lower substrate 100 . The driving ICs 410 and 510 are connected to the output end 30 of the FPCF 10 . The input end 20 of the FPCF 10 is connected to the PCB 650 . The PCB 650 includes control devices (not shown) that control the LCD. The control signals generated from the control devices are transferred to the input end 20 of the FPCF 10 through the PCB 650 . The signals transferred to the input end of the FPCF go to the output end 30 through the wirings. The signals transferred to the output end are transferred to the gate IC ( 410 ) and/or data IC ( 510 ). The signals transferred to the gate IC and data IC control the LCD.
[0039] FIG. 13 shows a cross section of an embodiment of the present invention. On both sides of a flexible film 11 , the longitudinal wirings 17 and the transversal wiring 15 are formed with the adhesive material 12 . An adhesive layer 13 for the protection film 14 is formed on the wirings, and the protection film 14 is formed on the adhesive layer 13 .
[0040] The flexible film 11 is made of polymers like polyimide. Polyimide is flexible and resist well against heat. The flexible film 11 that is as thick as 12.5 μm˜75 μm is available. If the flexible film 11 is thicker than 50 μm, it becomes less flexible. Therefore 12.5 μm˜50 μm thickness is preferable for a polyimide film, but on the thickness may vary depending on the film material.
[0041] The adhesive 12 for wirings is an epoxy group resin or a phenol group resin and is about 10 μm˜20 μm thick, which is almost the same thickness as the wirings 15 and 17 .
[0042] The wirings are made of metal like copper. The wirings are formed on the adhesive 12 . The wirings are formed on both surface of the flexible film on the adhesive 12 , and electrically connected to each other through the holes formed in the flexible film.
[0043] The wirings 15 and 17 are covered with an insulating film made of polymer, and are exposed at the input end and the output end. Therefore, the FPCF can be electrically coupled to other components.
[0044] The insulating film 14 covering the wirings is made of polyimide. The adhesive 13 can be epoxy group, acryl group, or polyester group. The adhesive 13 is as thick as 15 μm˜30 μm. The insulating film 14 is as thick as 7 μm˜15 μm.
[0045] The present embodiment shows that the wirings are formed on a film with an adhesive, but the FPCF can be formed without adhesive, and in various ways depending on materials and methods.
[0046] An embodiment of the present invention discloses a flexible printed circuit film (FPCF) whose wirings are mostly formed in the transversal and the longitudinal direction of the FPCF. Thus the transversal wirings are intended to be at right angle against the longitudinal wirings. It means that more than 98% of the total wirings are formed in the transversal direction or the longitudinal direction, and the remainders are formed in inclined directions. The wirings intersect each other in different layers. This structure of FPCF can reduces interferences among the signals transferring through the FPCF, even with a higher density of wirings in a smaller area.
[0047] It will be apparent to those skilled in the art that various modifications and variations of the present invention can be made without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of the invention including the scope of the appended claims and their equivalents. | A flexible printed circuit film has a first wiring and a second wiring. The first wiring is formed on a layer other than where the second wiring is formed, and crosses the second wiring almost at right angle 90°. This structure of the flexible printed circuit film enables to make electronic devices lighter, smaller, and denser than the conventional one. This structure of the flexible printed circuit film also reduces the interferences among the signals coming from the flexible printed circuit film. | 7 |
This is a division of application Ser. No. 08/570,762, filed Dec. 12, 1995, now U.S. Pat. No. 5,610,103.
BACKGROUND
1. Technical Field:
This invention relates to the elimination of voids formed when material deposited over a surface of a substrate having holes therein, such as for vias, contacts, or lines, fills a top portion of the holes but not a bottom portion thereof, and more particularly, to the elimination of such voids formed during a physical vapor deposition process.
2. Background Art:
Physical vapor deposition (PVD) of materials onto a substrate is a vital step in the manufacture of semiconductor devices. For example, this process is often used to deposit electrically conductive materials into high aspect ratio holes (i.e. holes with a depth to width ratio greater than one) forming inter-level vias or contacts within a semiconductor substrate. Traditionally, physical vapor deposition techniques have involved sputtering particles from a sputter target into a PVD processing chamber which is held in a ultra-high vacuum condition. Typically, the sputtered particles have a neutral charge and tend to move in straight line paths within predictable trajectories from the target surface . Most of these trajectories are other than perpendicular to the surface of the substrate. In some applications, a plasma is used to ionize some of the sputtered particles, which are then drawn toward the substrate by an electrically biased substrate pedestal. The biased pedestal imparts a directionality to the ionized atoms, including those traveling non-perpendicular to the substrate, so that they impact the substrate in a predetermined orientation. Ideally, for filling the aforementioned high aspect ratio holes, the direction of the ionized atoms would be perpendicular to the surface of the substrate. However, the aforementioned plasma formed in traditional physical vapor deposition processing devices usually exhibits a relatively low density, and so a very low ionization rate. Consequently, few of the sputtered atoms are actually ionized and most remain neutrally charged. Thus, in either of the above-described sputtering processes, a majority of the sputtered particles are neutrally charged, and do not change direction after leaving the surface of the target. This results in many of the sputtered particles not even reaching the substrate, and those that do impinge on the substrate in random directions. Many of these particles impact in a generally traverse direction to the surface of the substrate and build up along the upper walls of a high aspect ratio hole. This causes the top of the hole to be filled first and close off, leaving a void in the bottom portion. Such a void in the bottom of the hole can make the inter-level via an unreliable electrical contact.
FIG. 1 exemplifies a semiconductor substrate 10 produced according to the aforementioned prior art physical vapor deposition methods. As can be seen in this cross-sectional view, the substrate 10 includes a bottom layer 12 of silicon with an overlying oxide film layer 14 (i.e. SiO 2 ). A high aspect ratio hole 16 exists in the oxide film layer 14. In addition, a layer 18 of aluminum (Al) has been deposited over the oxide film layer 14. Due to the aforementioned randomly impacting sputtered atoms, the deposition material has built up on the upper walls of the hole 16 and closed it off, resulting in a void 20 in the lower portion of the hole 16.
In the past, attempts at eliminating the void once it has formed have involved heating the substrate and/or subjecting it to a high pressure environment. The heating is intended to soften the deposited material so that it flows into the hole, a process known as "reflow". At elevated temperatures, a metal will creep along a surface and fill any low spots in the film layer within which the metal resides. Although this method can work for many applications, temperatures high enough to flow some deposition materials would also damage the substrate or the structures formed thereon. Accordingly, heating the substrate to eliminate the void is sometimes undesirable. Subjecting the substrate to a high pressure atmosphere mechanically forces the material deposited over the top of the hole into the void space due to the force exerted by the high pressure atmosphere on the material. The material may have been softened by heating to facilitate this forcing. Although this latter method works well for the applications it was intended, some disadvantages exist. For example, the pressures required to force material into the void can sometimes approach 10 kpsi depending on the characteristics of the deposition material and its thickness over the void. A pressurizing device capable of producing pressures as high as 10 kpsi can be quite complex. In addition, the high pressure can in some instances damage the substrate or the structures formed thereon.
There has been an attempt to avoid the use of these high temperatures and pressures by employing ultrasonic vibration during the deposition process. This method involves fastening the substrate to a base, then subjecting the base, and so the substrate, to ultrasonic energy while at the same time sputter depositing aluminum on the substrate. The substrate is also heated, but at a lower temperature than typically used in the previously described processes. Although, this method works well for the application it was intended, there are drawbacks. The process must be carried out in a deposition chamber which has been specifically modified to impart the ultrasonic energy and heat during the actual deposition procedure. It is unknown what effects the ultrasonic energy and relatively low temperature will have on the deposition process or the resulting deposition layer, or whether existing deposition chambers can be retrofitted with the necessary equipment. In addition, it is believed that the addition of the steps required to apply the ultrasonic energy and heat could increase the deposition processing time, thereby reducing substrate throughput.
Therefore, a need exists for a method of eliminating the void left at the bottom of high aspect ratio holes which does not rely on subjecting the substrate to damaging heat or pressure, and which is not performed, in situ, during the deposition process.
SUMMARY
The present invention is directed to a novel method of eliminating or substantially eliminating the aforementioned void formed in the bottom of high aspect ratio holes following the completion of the physical vapor deposition of a material over the surface of a substrate. This method employs ultrasonic waves to create a plastic deformation in the already deposited material adjacent the void, without significantly affecting the material elsewhere on the substrate. The plastically deformed material then flows into the void due to the force exerted on it by a pressure difference between a fluid employed in the ultrasonic device producing the waves and a vacuum left in the void as a result of the previous physical vapor deposition process.
Specifically, the foregoing is attained by a method of substantially eliminating the voids which includes placing the substrate in an ultrasonic processing chamber filled with a fluid and having an ultrasonic source. The ultrasonic source is used to generate ultrasonic waves in the fluid at a frequency no higher than is sufficient to cause a flow of the material adjacent the voids into these voids. Preferably, the ultrasonic waves generated are uni-directional waves, and the substrate is oriented in the chamber such that the surface of the material deposited over the substrate is impinged by the ultrasonic waves in a substantially perpendicular direction.
In the case where the exact frequency which will cause the material overlying the void to flow is not known, the ultrasonic waves are initially generated at a relatively low frequency. Then, the frequency is increased over time until the material adjacent the voids flow into the voids.
The above-described process is performed in a stand-alone ultrasonic processing unit, and only after the deposition process has been completed to form the film layer being subjected to the ultrasonic waves. Thus, there is no question is of affecting the deposition process, or having to modify existing deposition equipment, as with some methods which employ ultrasonic vibration and low level heat during the deposition process itself. The deposition process can be accomplished as before, and the aforementioned voids filled afterwards. This has considerable advantages. First, the deposition process is complex and the quality of the resulting deposition layer is dependent on many factors. It is believed the introduction of low level heat and ultrasonic vibration during the deposition process could have unknown complicating effects. Existing deposition chambers can be employed, as is, using the described embodiments of the present invention. It is unknown whether these existing units can be modified to include an ultrasonic capability during deposition. It is possible all new equipment would have to be purchased to implement the ultrasonic treatment into the deposition process. In addition, deposition chambers are relatively complex and expensive pieces of equipment, as compared to a ultrasonic processing chamber. Instead of tying up the more expensive deposition equipment due to a potential increase in processing time required to accomplish the aforementioned concurrent ultrasonic vibration procedure, substrate throughput from the deposition chamber can be maintained by employing separate ultrasonic chambers to eliminate the unwanted voids.
In addition to the just described benefits, other objectives and advantages of the present invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.
DESCRIPTION OF THE DRAWINGS
The specific features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
FIG. 1 is a cross-sectional drawing of a semiconductor substrate following physical vapor deposition showing an inter-level via or hole with void in its lower portion.
FIG. 2 is a cross-sectional, schematic drawing of a ultrasonic device employed to perform a method of eliminating inter-level via voids in a substrate according to the present invention.
FIG. 3 is a block diagram of a method of eliminating inter-level via voids in a substrate according to the present invention.
FIG. 4 is a cross-sectional drawing of a semiconductor substrate following the elimination of inter-level via voids by the method of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described with reference to the drawings.
FIG. 2 depicts an ultrasonic apparatus having a processing chamber 22 containing an ultrasonic source 24 and filled with a fluid 26. The ultrasonic source 24 employed should have a mode of operation in which uni-directional ultrasonic waves 28 are produced in the longitudinal direction within the chamber 22. Although any suitable ultrasonic chamber 22 and source 24 can be employed, one suggested apparatus is the GENSIS ultrasonic generator manufactured by Crest Ultrasonics. In addition, it is preferred that the fluid 26 filling the chamber 22 be de-ionized water. De-ionized water will transmit the ultrasonic energy to the substrate without causing any adverse reactions with the substrate 10 or any of its incorporated structures. However, it is not intended that the present invention be limited to using deionized water. Any suitable fluid, including other liquids and pressurized gases, can be employed through which sufficient energy in the form of ultrasonic waves can be transmitted to the substrate while not causing any undesirable reactions with the substrate.
In reference to FIGS. 2 and 3, a method according to the present invention will be described. A substrate 10, such as the one described in association with FIG. 1, is placed in the chamber 22, preferably disposed in a substrate holder 29. It is noted that the relative size and proportion of the substrate 10 and holder 29 is changed to better show the effect of the present invention. Preferably, the substrate holder 29 orients the substrate 10 such that the longitudinally propagating ultrasonic waves 28 generated by the source 24 impact the exterior-facing surface of the deposited layer 18 in a substantially perpendicular direction. Once the substrate 10 is in place, the chamber 22 is closed and the ultrasonic source 24 activated. The process preferably takes place with the chamber 22 at ambient pressure and temperature, or even at a reduced pressure and temperature. The ultrasonic waves 28 generated by the source 24 will propagate through the fluid 26 and impinge on the surface of the deposited layer 18 of the substrate 10. This causes a longitudinally directed vibration in the material making up the deposited layer 18. If enough energy is absorbed from the ultrasonic waves 28 by the layer 18, the vibration will result in the deposited layer 18 undergoing a plastic deformation. Plastic deformation of the deposition layer 18 is desirable as will become apparent below. To achieve the desired deformation, the frequency of the ultrasonic waves 28 is made high enough to ensure sufficient energy is absorbed by the deposition layer 18. The maximum energy absorption occurs when the frequency of the ultrasonic waves 28 is high enough to cause a resonance condition within the deposition layer material. It is believed that at resonance the energy absorption will be at least sufficient in most commonly used deposition layer materials (e.g. aluminum) to cause the aforementioned plastic deformation. However, a lower frequency may be sufficient to trigger the deformation. Methods associated with selecting an ultrasonic wave frequency which will cause the desired deformation of the deposition layer material (and perhaps a resonance condition) will be discussed later.
Once the deposition layer material undergoes plastic deformation from the action of the impinging ultrasonic waves 28, it will flow into the aforementioned void 20 due to the pressure differential between the void 20 and the chamber fluid 26. The original physical vapor deposition process was conducted in a ultra-low pressure environment. Accordingly, the void 20 will-exhibit this same low pressure (typically on the order of 10 -2 to 10 -3 torr). The fluid 26 inside the chamber 22, on the other hand, is preferably at ambient pressure, or at least a higher pressure than that of the void. Accordingly, the pressure inside the chamber 22 will exceed that existing within the void 20, thereby creating the aforementioned pressure differential. The flow of the deposition layer material into the void 20 occurs because the aforementioned plastic deformation softens the material enough that the force exerted on it by the pressure differential pulls the material into the void 20. Thus, the void 20 is eliminated (or at least substantially eliminated).
Preferably, only the deposited material adjacent the void 20 undergoes the aforementioned plastic deformation and flow. This selective process is possible because the frequency at which the portion of the deposited layer 18 near the void 20 will plastically deform is different from the frequency at which the remaining portion of the deposited layer 18 will deform. It is believed that the frequency which will cause the plastic deformation of the portion of the deposition layer 18 adjacent a hole 16 is lower than the frequency which would cause deformation in the remainder of the deposited layer 18. Accordingly, the frequency of the ultrasonic waves 28 produced from the source 24 can be manipulated such that plastic deformation is created in the portion of the deposition layer material near the void 20 and not in the remaining portion of the layer 18. Thus, it is preferred that the ultrasonic source 24 be tuned to a frequency no greater than that which will produce the aforementioned plastic flow in the deposition layer material near the void 20.
Of course, the exact frequency at which the material will reach this point of plastic deformation and flow will vary depending on the mechanical characteristics of the material itself and its thickness. Accordingly, in the case where this exact frequency is not known, the preferred method is to start at a relatively lower frequency, say around 10 kHz or less, and increase the frequency until the deposition layer material adjacent the void 20 is displaced into the hole 16. For an aluminum deposition layer of typical thicknesses produced by physical deposition methods, the point of plastic deformation and flow is believed to be in the several tens of MHz range.
As alluded to previously, the frequency at which the aforementioned plastic deformation will occur is believed to be at or near the resonant frequency of the material adjacent the void, although this may not always be the case. A lower frequency might trigger the flow. However, even if plastic flow occurs at a frequency lower than the resonant frequency, the deposition layer material not adjacent the hole 16 will still be essentially unaffected. As explained above, it is believed a higher frequency than that required to deform the material overlying the hole 16 is required to deform the material overlying the remaining portions of the substrate 10.
FIG. 4 exemplifies the substrate 10 after the ultrasonic processing is complete. As can be seen, the deposition layer material previously adjacent the void has flowed to the bottom of the hole 16. A dip or indentation 30 will exist in the area outside the filled hole 16. If irrelevant to the performance of the device being manufactured, this indentation can remain. However, if desired, the surface can be planarized via well known methods. This planarization can be accomplished after additional material has been deposited over the surface of the substrate, if desired. It is also noted that FIG. 4 depicts a case where the deposited layer was thick enough that the entire depth of the hole 16 was filled. However, if the diameter of the hole or the thickness of the deposited layer is such that some portion of the upper portion of the hole is not filled, additional steps can be taken to complete the hole-filling process. For instance, additional material could be deposited over the surface of the substrate. As discussed previously, a typical physical vapor deposition process will result in material being deposited onto the upper walls of a high-aspect ratio hole. Accordingly, the very area that requires filling will be filled by this further deposition. Of course, the resulting surface of the substrate would include a dip or indentation in the area overlying holes. This unevenness can be eliminated by the aforementioned planarization processes.
While the invention has been described in detail by reference to the preferred embodiment described above, it is understood that variations and modifications thereof may be made without departing from the true spirit and scope of the invention. For instance, the fluid employed in the above-described ultrasonic processing chamber could be chosen to enhance the energy transfer to the substrate, or to perform some additional process on the substrate during the ultrasound procedure. Additionally, the temperature and pressure within the ultrasonic processing chamber might be manipulated to enhance the hole-filling process. For example, increasing the temperature and/or pressure inside the chamber could enhance the hole filling process, as long as these increases are not so large as to damage the substrate. | A method of eliminating or substantially eliminating voids formed in the bottom of high aspect ratio holes following the physical vapor deposition of a material over the surface of a substrate. The method includes placing the substrate in an ultrasonic processing chamber filled with a fluid and having an ultrasonic source. The ultrasonic source is used to generate ultrasonic waves at a frequency no higher than is sufficient to cause a flow of the material adjacent the voids into these voids, without significantly affecting the deposited material elsewhere on the substrate. | 7 |
FIELD OF INVENTION
[0001] The present invention relates to micropumps, and more particularly, in one representative and exemplary embodiment, to piezoelectrically actuated, high aspect ratio micropumps having integrated check valves for improved performance, efficiency and production cost savings in microfluidic applications.
BACKGROUND
[0002] Development of microfluidic technology has generally been driven by parallel ontological advancements in the commercial electronics industry with the ever-increasing demand for sophisticated devices having reduced part counts, weights, form factors and power consumption while improving or otherwise maintaining overall device performance. In particular, advancement of microfluidic technology has met with some success in the areas of packaging and the development of novel architectures directed to achieving many of these aims at relatively low fabrication cost.
[0003] The development of microfluidic systems, based on for example, multilayer laminate substrates with highly integrated functionality, have been of particular interest. Monolithic substrates formed from laminated ceramic have been generally shown to provide structures that are relatively inert or otherwise stable to most chemical reactions as well as tolerant to high temperatures. Additionally, monolithic substrates typically provide for miniaturization of device components, thereby improving circuit and/or fluidic channel integration density. Potential applications for integrated microfluidic devices include, for example, fluidic management of a variety of Microsystems for life science and portable fuel cell applications. One representative application includes the use of ceramic materials to form micro-channels and/or cavities within a laminate structure to define, for example, a high aspect ratio micropump.
[0004] Conventional pumps and pumping designs have been used in several applications; however, many of these are generally too cumbersome and complex for application with microfluidic systems. For example, existing designs typically employ numerous discrete components externally assembled or otherwise connected together with plumbing and/or component hardware to produce ad hoc pumping systems. Consequently, conventional designs have generally not been regarded as suitable for integration with portable ceramic technologies or in various applications requiring, for example, reduced form factor, weight or other desired performance and/or fabrication process metrics. Moreover, previous attempts with integrating microfluidic pumps in laminated substrates have met with considerable difficulties in producing reliable fluidic connections and/or hermetic seals capable of withstanding manufacturing processes and/or operational stress while maintaining or otherwise reducing production costs. Accordingly, despite the efforts of prior art pump designs to miniaturize and more densely integrate components for use in microfluidic systems, there remains a need for high aspect ratio micropumps having integrated check valves suitably adapted for incorporation with, for example, a monolithic device package.
SUMMARY OF THE INVENTION
[0005] In various representative aspects, the present invention provides a system and method for fluid transport in microfluidic systems. A representative design is disclosed as comprising a fluid inlet opening, a fluid outlet opening, a pumping cavity, a reservoir cavity, a check valve substantially enclosed within each of the cavities, and means for moving fluid through the device. An integrated high aspect ratio micropump, in accordance with one embodiment of the present invention, may be formed utilizing multilayer ceramic technology in which check valves are integrated into a laminated ceramic structure; however, the disclosed system and method may be readily and more generally adapted for use in any fluid transport system. For example, the present invention may embody a device and/or method for providing integrated pumping and/or valving systems for use in fuel cell fuel delivery and/or partitioning applications.
[0006] One representative advantage of the present invention would allow for improved process control and manufacturing of integrated micropump systems at substantially lower cost. Additional advantages of the present invention will be set forth in the Detailed Description which follows and may be obvious from the Detailed Description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by means of any of the instrumentalities, methods or combinations particularly pointed out in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Representative elements, operational features, applications and/or advantages of the present invention reside inter alia in the details of construction and operation as more fully hereafter depicted, described and claimed—reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. Other elements, operational features, applications and/or advantages will become apparent to skilled artisans in light of certain exemplary embodiments recited in the detailed description, wherein:
[0008] [0008]FIG. 1 representatively depicts a cross-section, elevation view of a package substrate in accordance with an exemplary embodiment of the present invention;
[0009] [0009]FIG. 2 representatively illustrates one exemplary method for depositing check valves within the package substrate depicted in FIG. 1; and
[0010] [0010]FIG. 3 representatively depicts a cross-section, elevation view of an assembled and substantially sealed micropump device package in accordance with another embodiment of the present invention.
[0011] Those skilled in the art will appreciate that elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0012] The following descriptions are of exemplary embodiments of the invention and the inventors' conceptions of the best mode and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description is intended to provide convenient illustrations for implementing various embodiments of the invention. As will become apparent, changes may be made in the function and/or arrangement of any of the elements described in the disclosed exemplary embodiments without departing from the spirit and scope of the invention.
[0013] Various representative implementations of the present invention may be applied to any system and/or method for fluid transport. As used herein, the terms “fluid”, “fluidic” and/or any contextual, variational or combinative referent thereof, are generally intended to include anything that may be regarded as at least being susceptible to characterization as generally referring to a gas, a liquid, a plasma and/or any matter, substance or combination of compounds substantially not in a solid or otherwise effectively immobile condensed phase. As used herein, the terms “inlet” and “outlet” are generally not used interchangeably. For example, “inlet” may generally be understood to comprise any cross-sectional area or component feature of a device, the flux through which tends to translate fluid from a volume element substantially external to the device to a volume element substantially internal to the device; whereas “outlet” may be generally understood as referring to any cross-sectional area or component feature of a device, the flux through which tends to translate fluid from a volume element substantially internal to the device to a volume element substantially external to the device. On the other hand, as used herein, the terms “liquid” and “gas” may generally be used interchangeably and may also be understood to comprise, in generic application, any fluid and/or any translationally mobile phase of matter. As used herein, the term “purged”, as well as any contextual or combinative referent or variant thereof, is generally intended to include any method, technique or process for moving a volume element of fluid through the outlet of a device so as to dispose or otherwise positionally locate the “purged” volume element external to the device. Additionally, as used herein, the terms “valve” and “valving”, as well as any contextual or combinative referents or variants thereof, are generally intended to include any method, technique, process, apparatus, device and/or system suitably adapted to control, affect or otherwise parameterize fluid flow scalar quantities (e.g., volume, density, viscosity, etc.) and/or fluid flow vector quantities (i.e., direction, velocity, acceleration, jerk, etc.). Additionally, as used herein, the terms “pump” and “pumping”, or any contextual or combinative referents or variants thereof, are generally intended to include any method, technique, process, apparatus, device and/or system suitably adapted to flow or otherwise translate a fluid volume element from a first location to a second location.
[0014] A detailed description of an exemplary application, namely a system and method for making a micropump in a laminar device package is provided as a specific enabling disclosure that may be readily generalized by skilled artisans to any application of the disclosed system and method for microfluidic transport in accordance with various embodiments of the present invention. Moreover, skilled artisans will appreciate that the principles of the present invention may be employed to ascertain and/or realize any number of other benefits associated with fluid transport such as, but not limited to: improvement of pumping efficiency; reduction of device weight; reduction of device form factor; improved sample loading in microfluidic assays; improvement in sample throughput; sample multiplexing and/or parallel sample processing; integration with micro-array techniques and/or systems; microfluidic sample transport; pumping of fuel and/or fuel components in a fuel cell system and/or device; and any other applications now known or hereafter developed or otherwise described in the art.
[0015] In one representative application, in accordance with an exemplary embodiment of the present invention, a laminar micropump system, as generally depicted in FIG. 3, is disclosed. The system generally includes at least one substantially flexible, or otherwise at least partially deformable, material comprising, for example, a flapper valve 350 , 360 . The disclosed valving system, in certain representative embodiments, may include features to control the effective magnitude of cross-sectional area presented for fluid acceptance in order to at least partially control or otherwise parameterize fluid flux through said inlet opening 310 and/or outlet opening 340 . For example, inlet opening 310 and/or outlet opening 340 may comprise a taper, a flare, a constriction, a plurality of corrugations, a bend, a pinch, an oblique plane of fluid acceptance (e.g., wherein inlet opening 310 and/or outlet opening 340 facial alignment generally may be other than normal to the instantaneous vector of fluid flow) or such other means, features and/or methods now known, subsequently developed or otherwise hereafter described in the art.
[0016] The operation of flapper valves 350 , 360 generally provide passive means for substantially preventing or otherwise controlling or restricting the backflow of purged outlet fluid into reservoir chamber 330 and/or pumping chamber 370 . For example, outlet flapper valve 360 generally permits fluid flow when the flow vector (e.g., the direction of fluid pressure; also termed the “fluid transport gradient”) corresponds to translation of fluid volume elements away from inlet opening 310 through fluidic channels 320 toward outlet opening 340 . Additionally, outlet flapper valve 360 , in accordance with representative aspects of the present invention, conjunctively provides for effective prevention of fluid flow to outlet opening 340 when the instantaneous fluid transport gradient corresponds to translation of fluid volume elements away from outlet opening 340 through fluidic channels 320 toward inlet opening 310 (e.g., “backflow”). In an alternative exemplary embodiment, reservoir chamber 330 and/or pumping chamber 370 may further or alternatively comprise a mixing chamber, a reaction chamber and/or a fuel reformer chamber (in the case of application of the present invention, for example, to fuel cell systems).
[0017] One exemplary implementation of the present invention may be manufactured from the substrate representatively illustrated in FIG. 1, wherein a laminar substrate 300 is provided for the fabrication of a piezo-driven micropump. Outlet opening 310 is suitably configured to provide a path for fluid transport to pumping chamber 370 . Fluidic channel 320 provides fluidic communication between pumping chamber 370 and reservoir chamber 330 . Reservoir chamber 330 is generally configured to provide effective fluidic communication to outlet opening 340 . Skilled artisans, however, will appreciate that other channel configurations and/or circuit geometries may be employed in order to define inter alia various fluidic transport paths, for example, in a laminar substrate in accordance with various other embodiments of the present invention.
[0018] In one representative embodiment, openings for disposing flapper valves 350 , 360 are defined in substrate 300 such that flapper valves 350 , 360 may be suitably deposited in pumping chamber 370 and reservoir chamber 330 respectively, from substantially the same surface of substrate 300 presented during fabrication as depicted, for example, in FIG. 2. One exemplary benefit of the disclosed method of same-side device assembly resides in fewer process fabrication/control steps resulting in substantially lowered cost of production.
[0019] Other means for providing substantially passive valving function other than that of a flapper valve include, for example: a slit (e.g., duckbill valve), a plunger, a shuttle, a rotary stop-cock, a one-way flow gate or any other device feature, method or means for substantially passive valving now known, subsequently developed or hereafter described in the art. The same may be alternatively, conjunctively or sequentially used in various embodiments of the present invention. Skilled artisans will appreciate that the term “passive”, as it may refer to valving devices and/or function, generally connotes the ability of a valve and/or valve device feature so characterized, to actuate the operation of restriction, constriction and/or dilation of fluid inlet acceptance and/or fluid outlet purging in effective correspondence to the forces nominally inherent to the translation of fluid volume elements through the valve device. That is to say, when the fluid flow is in a first direction, the fluidic forces operate to actuate the valve into a first conformation (i.e., substantially open); and, when the fluid flow is in a second direction (e.g., for a binary valve, generally given as the “opposite direction”), the fluidic forces operate to actuate the valve into a second conformation (i.e., substantially closed).
[0020] In various exemplary embodiments, flapper valves 350 , 360 may be fabricated from silicone, silicone-based rubber, rubber, metal, metal alloy, polymer or such other materials whether now known or subsequently discovered or otherwise hereafter described in the art. In an exemplary application where passive check valves 350 , 360 comprise flapper valves, as generally depicted, for example, in FIG. 2, the valves may comprise a silicone-based rubber material. Additionally, flapper valves 350 , 360 may optionally comprise means for attachment, such as, for example, an extension tab having a substantially annular retaining ring for securing or otherwise at least partially immobilizing flapper valve 350 , 360 within device package substrate 300 . Various other attachment means and/or packaging features for retaining, localizing or otherwise disposing check valves known in the art may be used as well. For example, the following retaining means may be conjunctively, alternatively or sequentially employed: adhesives, organic epoxies, a mechanical anchor, press-fit clips, solder, clamps, seals, adaptors and/or such other retention, connection or attachment devices, means and/or methods, whether now known or otherwise hereafter described in the art.
[0021] [0021]FIG. 3 generally depicts two passive flapper valves 350 , 360 disposed within an exemplary monolithic package substrate 300 . The device package 300 generally comprises an input microfluidic channel 310 , an output microfluidic channel 340 and pump actuator element 380 . In one representative embodiment, pump actuator may comprise a piezoelectric micropump element 380 . In an exemplary embodiment, piezoelectric element 380 may be secured to the package substrate 300 by, for example, solder 390 . Accordingly, substrate 300 may comprise solder-wettable features 305 that are generally provided to permit secure solder attachment of piezoelectric element 380 and/or cover 375 to substrate 300 . Various other means for attaching piezoelectric element 380 and/or cover 375 to package substrate 300 may include, for example: epoxy, adhesive and/or such other attachment means and/or methods whether now known or hereafter described in the art. In yet another exemplary embodiment of the present invention, piezoelectric element 380 may alternatively be integrated within the package substrate; for example, between ceramic layers in a position substantially internal to the device as the package is built up.
[0022] As electric current is supplied to the package, piezoelectric element 380 operates as a deformable diaphragm membrane whose deformation (e.g., “stroke volume”) causes oscillating over- and under-pressures in pump chamber 370 . Pump chamber 370 , in an exemplary embodiment, may be bounded by, for example, two passive check valves 350 , 360 . The pump actuation mechanism 380 need not be limited to piezoelectric actuation, but may alternatively, sequentially or conjunctively be driven by electrostatic or thermopneumatic actuation or such other means and/or methods now known, subsequently derived or otherwise hereafter described in the art.
[0023] During the movement of the diaphragm element (i.e., piezoelectric element 380 ) in a direction which tends to enlarge the pump chamber volume, an under-pressure is generated in pump chamber 370 causing fluid to flow through inlet channel 310 in a flow direction which causes pump flapper valve 350 to distend toward piezoelectric element 380 thereby permitting fluid to flow around flapper valve 350 to enter into pump chamber 370 . Since the fluid transport gradient during the under-pressure stroke is anti-parallel to the fluid flow acceptance conformation of reservoir flapper valve 360 , flapper valve 360 seals so as to at least partial reduce the occurrence of fluid disposed in outlet channel 340 re-entering via fluidic channel 320 into pump chamber 370 (e.g., backflow). Accordingly, this component of the pump cycle is termed the “supply mode” or the “supply stroke”.
[0024] In the alternate and next phase of the stroke cycle, the movement of the diaphragm element 380 in a direction which tends to reduce the pump chamber volume causes an over-pressure to be generated in pump chamber 370 , thereby flowing fluid through outlet opening 340 as a result of fluid flowing out of pump chamber 370 into fluidic channel 320 in a flow direction which causes reservoir flapper valve 360 to distend toward, for example, cover plate 375 thereby permitting fluid to flow around flapper valve 370 to enter into reservoir chamber 330 and subsequently into outlet channel 340 . Since the fluid transport gradient during the over-pressure stroke is anti-parallel to the fluid flow acceptance conformation of pump flapper valve 350 , flapper valve 350 seals so as to at least partial reduce the occurrence of fluid disposed in pump chamber 370 from back-flowing into the inlet channel 310 . Accordingly, this component of the pump cycle is termed the “pumping mode” or the “delivery stroke”.
[0025] The volume of the pump chamber upon relaxation of the actuation diaphragm is known as the dead volume V 0 and the volume the actuation membrane deflects during a pump cycle generally defines the stroke volume ΔV. The ratio between the stroke volume and dead volume may be used to express the compression ratio ε. Due in part to the relatively small stroke of micro-actuators and the relatively large dead volume, the compression ratio
ɛ = Δ V V 0
[0026] is usually relatively small.
[0027] The pressure cycles (e.g., “pressure waves”) generated from the actuation supply and pump modes typically operate to switch the valves. In the limit of the pump chamber 370 being filled with an ideally incompressible fluid, the pressure waves would ideally propagate from the actuation diaphragm to the valves with no net pressure loss—in which case, the compression ratio is generally not regarded as an important metric of pump performance and/or efficiency. However, where the fluid medium is not ideally incompressible, there exists a compressibility factor κ>0 which may be employed to characterize the tendency of a real fluid to dampen the propagation of the actuation pressure wave Δp. If the pressure change Δp falls below a certain value p′ (e.g., the threshold pressure differential for actuation of a valve), the pump generally will not properly operate. Accordingly, a minimum condition for operation of any micropump may be expressed as |Δp|≧|p′|.
[0028] Given the compressibility κ of a liquid, the pressure change Δp may be calculated (if the volume change ΔV induced by the actuator is known) in accordance with the equation V 0 +ΔV=V 0 (1−κΔp). If this expression is substituted into those previously presented, the compressibility ratio ε for liquid micropumps may be expressed as ε liquid ≧κ|p′|. Accordingly, a threshold valve actuation pressure p′ of 1 kPa in combination with the compression ratio for water κ water (5*10 −9 m 2 /N) would yield a minimum compression ratio ε water of 510 −6 . In this case, where the stroke volume ΔV is assumed to be 50 nl, the dead volume V 0 generally may not exceed 10 ml. Skilled artisans, however, will appreciate that the preceding example will generally only hold true where the pump chamber 370 is completely filled with liquid and no degassing and/or bubble occlusion occurs during micropump operation and therefore provides a first-order approximation for the determination of operational parameters and/or design specifications.
[0029] In the case of a gas pump, assuming an ideal gas having an adiabatic coefficient of γ (1.4 for air), at atmospheric pressure p 0 and an actuation pressure wave of magnitude Δp, the following expression may be obtained:
p 0 V 0 γ =( p 0 +Δp )( V 0 +ΔV ) γ
[0030] Accordingly, it may be shown that the criterion for the compression ratio of a gas micropump may be similarly derived as
ɛ gas ≥ ( p 0 p 0 - p ′ ) 1 γ - 1
[0031] and, in the case of isothermal state transitions, the adiabatic coefficient γ may be taken as equal to unity. For the device previously presented for the micropumping of water (e.g., p′=1 kPa and ΔV=50 nl), the dead volume V 0 for the same system adapted for the micropumping of air must generally not exceed 5 μl.
[0032] In conventional micropump operation, gas bubbles may often remain in the pump chamber during the priming procedure and/or the liquid may even volatized in response to temperature changes during operation. In these cases, the expression for the compression ratio of a liquid ε liquid ≧κ|p′| will no longer hold true since the compressibility of the gas bubble is generally much larger than the compressibility of the liquid. Depending on the volume of the gas bubble, the actuation pressure wave will be dampened in an amount that may be calculated if the volume of the gas bubble is substituted for the dead volume in the appropriate equation presented vide supra. If the gas bubble volume becomes so large that the actuation pressure wave falls below the threshold valve actuation pressure, the micropump will fail. Consequently, in the limit of the entire pump chamber volume being filled with a gas, the operational design criteria for liquid self-priming pumps converges to the design criteria for those of gas micropumps.
[0033] Additionally, in practical applications, the design criteria may even need to be more stringent to account for higher-order fluid dynamics. For example, self-priming liquid micropumps must typically suck the liquid meniscus from the inlet 310 into the pump chamber 370 , thereby increasing the threshold critical pressure p′ in parity with the surface tension of the meniscus at the juncture between and/or within, for example, the microfluidic channels and the microfluidic valves. Those skilled in the art will recognize that other fluid dynamics and/or parametric contributions may require consideration in the determination of optimal operational specifications for a micropump in accordance with the present invention as they may be employed in a variety of practical applications and/or operating environments. The same shall be regarded as within the scope and ambit of the present invention.
[0034] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth in the claims below. The specification and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the claims appended hereto and their legal equivalents rather than by merely the examples described above. For example, the steps recited in any method or process claims may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any apparatus claims may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the claims.
[0035] Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of any or all the claims.
[0036] As used herein, the terms “comprises”, “comprising”, or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted by those skilled in the art to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same. | An exemplary method for making a micropump device is disclosed as providing inter alia a substrate ( 300 ), an inlet opening ( 310 ), and outlet opening ( 340 ), a pump chamber ( 370 ) and flapper valves ( 350, 360 ). The fluid inlet channel ( 310 ) is generally configured to flow a fluid through/around the inlet opening flapper valve ( 350 ). The outlet opening flapper valve ( 360 ) generally provides means for preventing or otherwise decreasing the incidence of outlet fluid re-entering either the pumping cavity ( 370 ) and/or the fluid inlet channel ( 310 ). Accordingly, the reduction of backflow generally tends to enhance overall pumping efficiency. Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve micropump operation in any microfluidic application. Exemplary embodiments of the present invention representatively provide for substantially self-priming gas/liquid micropumps that may be readily integrated with existing portable ceramic technologies for the improvement of device package form factors, weights and other manufacturing and/or device performance metrics. | 8 |
This application is a continuation of pending U.S. application Ser. No. 07/565,553 filed Aug. 10, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the invention relates to hardware components and, more specifically, an adjustable foot insert for tubing and a method of making such an insert.
2. Description of the Related Art
Adjustable foot inserts widely used in commmercial food service equipment and other situations where it is desirable or required to have legs on tables, components, appliances, etc., that are adjustable. Since it is required by many sanitary codes that devices used to support food service equipment have no exposed threads, an adjustable foot insert was developed which comprises two pieces that are die cast and then assembled. A foot element is die cast in a cylindrical shape, with one end being the bottom and flattened for contact with the floor, and the other end, or top, being threaded. A cylindrical sleeve is then die cast, with a smooth interior. Threads are then tapped or machined onto the interior surface of the sleeve, the foot is threaded into place, and the top portion of the sleeve, opposite the end where the bottom portion of the foot protrudes, is then folded over in a process called swaging. The assembly can then be inserted into the hollow bottom of a leg of the appliance or table to be supported and the height of the appliance can then be adjusted by turning the foot element, thereby lengthening or shortening that leg. These inserts can also be used to compensate for uneven floors and ensure that an appliance or table is level and firmly seated on the floor.
Referring now specifically to the drawings, FIGS. 1-1A show the prior art adjustable foot insert. The prior art adjustable foot insert 52 is manufactured in the following manner. A sleeve element 2 is die cast in a tubular form and has an outside surface 16 and an inside surface 3. After the sleeve 2 is die cast, spiral threads 4 are tapped onto its inside surface 3. This separate tapping process is necessary because threads cannot be easily die cast on the inside of a hollow tube. A foot element 6 is then manufactured according to the prior art, being cylindrical in shape, with a lower end 14 and an upper end 12. The lower end 14 is either round or hexagonal in shape, and is hexagonal in the prior art insert shown in FIGS. 1-1A. The upper end 12 of the foot element 6 is cast with spiral threads 8 on its outside surface. The foot element 6 is then threaded into the upper end 48 of the sleeve element 2, as shown in FIG. 1. The threads 4 that are tapped onto the inside surface 3 of the sleeve element 2 begin at the upper end 48 of the sleeve element 2 and proceed close to, but short of, the lower end 50 of the sleeve element 2. The lower end 14 of the foot element 6 is passed through the upper end 48 of the sleeve element 2 and out of the lower end 50 of the sleeve element 2. The threads 8 of the upper end 12 of the foot element 6 come in contact with the threads 4 of the internal surface 3 of the sleeve element 2, at which point the foot element 6 can be threaded all the way into the sleeve element 2 until the bottom of the threads 8 of the foot element 6 reach the end of the threads 4 in the lower end 50 of the sleeve element 2.
It is important that the foot element 6 be prevented from unscrewing completely from the sleeve element 2 during adjustment of the height of the foot element 6 after installation into the leg of an appliance. Accordingly, after the foot element 6 is threaded into the sleeve element 2, the upper end 48 of the sleeve is rolled over, or swaged, to create a swaged end 18 (FIG. 1A) beyond which the foot element 6 can no longer pass.
The process of making this foot insert is expensive, because the outer sleeve is die cast in one piece. Particularities in the process of die casting make it impractical or impossible to die cast a hollow cylinder with threads on its inside surface, so these threads have to be tapped onto the inside of the tube after it is die cast. Also, it is important to prevent the foot insert from being threaded all the way out of the sleeve in either direction. Preventing the foot from being threaded out of the bottom of the sleeve is done by tapping threads inside of the sleeve close to, but not reaching, the bottom of the sleeve, thus preventing the foot from being lengthened too far. Preventing the foot from being threaded out of the top of the sleeve is more difficult to accomplish. In the known insert, this is done by swaging the upper end of the sleeve after the foot element is threaded into the sleeve, thus preventing the foot from being shortened too far.
The disadvantages to this method of making the insert are that it is time consuming, expensive and inefficient to tap the threads onto the inside of the die cast sleeve, and it is equally disadvantageous to swage the top end of the sleeve after the assembly of the insert.
The method to be disclosed overcomes these disadvantages by eliminating the need for the separate steps of tapping threads and swaging the sleeve, thus allowing a cheaper and more efficient manufacture of the insert.
SUMMARY OF THE INVENTION
The present invention discloses an improved method of making an adjustable foot insert. The improved method involves making the foot element in substantially the same way as in known, with a cylindrical shape, and a flat bottom for contact with the floor and a threaded upper portion. This piece is made in any traditional way, such as by die casting. The sleeve element is, however, not die cast as a hollow cylinder. It is die cast or injection molded in two pieces which combine to form a hollow cylinder, separated by a plane passing through its axis, each piece being half cylindrical in shape. Die casting or injection molding the sleeves in halves allows the threads to be die cast on the inside surface of the half sleeve. Thus, the need for tapping threads onto the inside surface of the sleeve is avoided.
When assembling the insert for use, the foot element is placed in one of the pieces, or half sleeves, and the other half sleeve is then placed over the foot element, so that the two half sleeves enclose the foot element.
This method of assembly also eliminates the need for swaging the top end of the sleeve. Each half sleeve is die cast or injection molded with the top end fully or partially closed or restricted. This is made possible because the foot element does not need to be threaded into the sleeve from the top during assembly. When the insert is assembled, the foot element is prevented from being shortened too far by the fully or partially closed off top of the half sleeves. The foot element is prevented from being lengthened too far by the known method of discontinuing the interior threads of the sleeves before the threads reach the bottom edge of the sleeve.
The sleeves are preferably die cast with pins and alignment holes on the surfaces along the edges of the abutment plane between the half sleeves. These pins and alignment holes prevent movement of one half sleeve relative to the other half sleeve along the plane separating the two half sleeves and assure proper alignment of the threads on the inside of each half sleeve. The alignment pins and holes can be made with an interference fit, allowing the two half sleeves to be pressed together in the assembly to hold them together tightly. Any other method of aligning and holding the two half sleeves tightly together after assembly can be used, such as, for example, ribs fittings into slots, flanges fitting into recesses, or fasteners such as screws, rivets, spun over or rivetted cast studs external springs clips or clamps. Further, and in addition to the previously described method of fastening the two half-sleeves together, once the assembled insert is installed in the end of a leg of a table or appliance, the leg holds the two half sleeves together and prevents them from spreading.
Thus, the disclosed method of manufacture avoids the need for tapping threads on the inside of the sleeve, and also avoids swaging, thus making the manufacturing process cheaper, simpler, and more efficient.
Also encompassed by the invention is the adjustable foot insert itself. Such an insert is easier and less expensive to manufacture and has a generally cleaner look. The insert consists of a cylindrical foot positioned between two halves of a sleeve assembly and threads are provided to permit the foot to be extended out from, or inserted into, the sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention follows, with reference to the accompanying figures in which:
FIG. 1 is an exploded perspective view of the prior art adjustable foot insert;
FIG. 1A is a perspective view of the prior art adjustable foot insert;
FIG. 2 is an exploded perspective view of the adjustable foot insert according to the invention;
FIG. 3 is a partially cut away elevational side view of the adjustable foot insert, according to the invention, in its environment;
FIG. 4 is a side by side view of the sleeve elements of the adjustable foot insert, according to the invention.
FIG. 5 is a partially broken away side elevation view of the adjustable foot insert, according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to FIGS. 2-5, the preferred embodiments of the inventionwill now be disclosed.
The adjustable foot insert 54, according to the invention, is manufactured by die casting or injection molding a foot element 20 which is substantially identical to the foot element 6 of the prior art adjustable foot insert 52, and has an upper end 26 and a lower end 28. It is preferred that the lower end 28 be a hexagonal bottom 24, as shown by FIG.2, to allow easy adjustment after installation through the use of a wrench,but it may be made in any desired shape. The upper end 26 is die cast or injection molded with spiral threads 22, on its outer surface, directed externally, as in the prior art foot element 6 (FIG. 1).
The sleeve for the foot element 20, according to the invention, is die castor injection molded in two parts, or half sleeve elements, 30 and 31 (FIG. 3).
Each half sleeve element 30, 31 is die cast or injection molded with spiralthreads 34 on its inner surface 56. This die cast or injection molded threading is made possible by manufacturing the sleeve in halves. Each half sleeve element 30, 31 also has an upper end 58 and a lower end 60. The half sleeve elements 30, 31 each have a fully or partially closed off top 36 at the upper ends 58. The threads 34 die cast or molded on the inner surface 56 of the half sleeve elements 30, 31 stop short of reachingthe lower end 60 of the half sleeve elements 30, 31. The half sleeve elements 30, 31 are separated by a contact surface 38 which runs through aplane passed through the cylinder axis of the half sleeve elements when they are assembled. One half sleeve element 31 is manufactured with a series of locator pins 40 on its contact surface 38, while the other half sleeve element 30 has a series of corresponding locator or alignment holes42 on its contact surface 38. These pins 40 and alignment holes 42 prevent movement of one half sleeve relative to the other half sleeve along the plane separating the two half sleeves and assure proper alignment of the threads on the inside of each half sleeve. It is also possible to place both locator pins and alignment holes on each half sleeve element. Any other method of aligning and holding the two half sleeve elements tightly together after assembly can be used, such as, for example, ribs fitting into slots, flanges fitting into recesses, or fasteners such as screws, rivets, spun over or rivetted cast studs or external clips or clamps. The adjustable foot insert 54, according to the invention, can then be assembled by placing the foot element 20 into one of the half sleeve elements, as shown in FIG. 2, so that the threads 22 of the foot element 20 are threadably engaged with the threads 34 of the half sleeve element, and the hexagonal bottom 24 of the foot element 20 protrudes from the lower end 60 of the half sleeve element. The other half sleeve element is then positioned adjacent to the first half sleeve element so that the locator pins 40 of one half sleeve element enter the corresponding locatorholes 42 of the other half sleeve element, and the half sleeve elements 30,31 meet at their contact surfaces 38. Preferably, the locator holes 42 are of a smaller diameter than the corresponding locator pins 40 so that the half sleeve elements, when pressed together, are held tightly together in an interference fit or press fit and in contact at their contact surfaces 38. The threads 34 of both half sleeve elements will then be threadably engaged with the threads 22 of the foot element 20. When the assembled adjustable foot insert 54 is inserted into a round leg 44 (FIG. 3), the outer surfaces 32 of the half sleeve elements 30, 31 come into contact with the inside surface of the round leg 44, so that the half sleeve elements 30, 31 are held together and no spreading between them can occur.
During adjustment of the height of the adjustable foot insert 54 by rotation or threading of the foot element 20, the foot element 20 is prevented from being shortened too much by the fully or partially closed off top 36 of the half sleeve elements 30, 31. The foot element 20 is alsoprevented from being lengthened too far by the end 46 of the threads 34 which are die cast or molded in the half sleeve elements 30, 31.
The disclosed method allows the construction of the adjustable foot insert in a cheaper, more efficient manner by avoiding the costly processes of tapping or machining the interior threads onto the cylindrical sleeve and swaging the upper end of the sleeve after assembly.
It should be noted that the lower end 28 of the foot element 20 can be hexagonal, round, or any other shape that the required use dictates. The adjustable foot insert 54, according to the invention, can also be made invarying lengths and diameters to meet a wide variety of uses. Also, it should be noted that the method disclosed and the resulting apparatus are not limited to die cast metals, and could be made with, for example, a zinc alloy, aluminum alloy or magnesium or copper based alloy.
While the invention has been described in conjunction with a specific embodiment of the adjustable foot insert and its manufacture, it should beunderstood that this is merely illustrative. Numerous modifications may be made to the assembly, and the elements used, and the method of manufactureused without departing from the spirit or scope of the invention and it is intended that the patent shall cover whatever features and methods of patentable novelty that exist in the invention and are encompassed within the following claims. | A foot element with exterior threads on a portion of its surface is die cast or injection molded. Two half sleeves are die cast or injection molded, and are each half cylindrical in shape and have threads on the inside surfaces of the half sleeves and one end is fully or partially closed off. The foot insert can be enclosed between the two sleeve halves and be adjustably extended out from or withdrawn into the completed sleeve. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to the monitoring of knitting units and is concerned, more particularly, with the sensing and comparison of multiple parameters in circular knitting units.
BRIEF DESCRIPTION OF THE PRIOR ART
Various procedures have been employed in the monitoring of knitting units to an indication of the nature of the actual knit with regard to a desired norm.
For example, a given knitting operation will consume a predetermined length of yarn in a preselected number of stitches per unit length of the knitted product. Deviations from these norms or parameters produce variations in the quality of the knit and, therefore, provide sensible or measurable bases for monitoring the quality of the knit.
This sensing or measuring has been accomplished in several ways which, however, have been complex and typically have required permanent association of the sensors with the knitting unit. Therefore, prior units have greatly increased the cost of multiple-unit knitting installation and have added undesirable complexity and volume or bulk in such installations. These problms are particularlly evident in circular-knitting installations.
The prior monitoring procedures have involved a variety of measuring steps for determining the yarn input and the stitch count. Tachometers have been used to indicate the speed of the knitter for auging the stitch rate. Stroboscopes have been conveniently employed for circular knitters.
The yarn rate has been sensed by tachometers or by measured and marked lengths of yarn. One system employs electrostatic marking of the yarn, at spaced points along its length.
The quality of the knit may then be determined in terms of the length of yark consumed in forming a predetermined number of stitches and in comparison with the desired norms.
French Pat. No. 2,038,483 discloses a yarn-monitoring system including a yarn feeder having a rotating disc with alternating dark and light sections, and a reader for transforming the resultant light pulses into electrical pulses. A microcontact in engagement with a rotating element of the machine delivers a simple pulse per revolution, which pulses are accumulated in a counter serving a function selector. The feeder signals are amplified and formed and delivered via an integrating meter to an intermediate unit connectable with the counter. A control circuit is provided in parallel with the intermediate element to control the cycling of pulses from the feeder.
This yarn-measuring system has proven effective, with an accuracy involving only a 1% margin of error. However, such systems involve a great deal of elaboration of the intallation since elements functional to the sensor system must be incorporated in each unit. Also, additional sensing means are necessary to achieve complete monitoring of the operation.
Therefore, prior knitting monitors have not been found to be entirely satisfactory, particularly for circular knitting installations.
SUMMARY OF THE INVENTION
In general, the preferred form of the present invention comprises a portable monitoring unit including a yarn sensor for delivering a fixed number of yarn pulses per unit of yarn length, a gate for receiving the yarn pulses for delivery to a numeral display, a needle detector for delivering needle pulses to a counter, and switch means for connecting the yarn sensor and the needle detector to the gate. Preferably, the monitoring unit includes a frequency meter and the switch means includes means for selectively delivering the yarn pulses and the needle pulses through the gate for an interval set by the frequency meter.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a portable monitor unit for knitting machines.
It is another object of the present invention to provide a portable monitor unit for circular knitting machines which is capable of use with a plurality of machines without requiring complication of the structure of the individual machines.
It is a further object of the present invention to provide a portable monitor unit for circular knitting machines which is capable of indicating the relationship between the number of knit stitches and the length of yarn consumed in the stitches.
It is another object of the present invention to provide a portable monitor unit for circular knitting machines which is capable of indicating the rate of yarn consumption of the machine.
It is another object of the present invention to provide a portable monitor unit for circular knitting machines which is capable of indicating the rotational speed of the machine.
Another object of the present invention is the provisions of a portable monitor unit for circular knitting machines which is capable of indicating, selectivley, the linear yarn consumption for a selected number of stitches, the linear speed of the yarn, and the rpm of the knitting machine.
BRIEF DESCRIPTION OF THE DRAWING
These and other objects of the invention and a better understanding thereof may be derived from the following description and the accompanying drawing, in which
The drawing is a schematic diagram of the preferred form of monitor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawing, the preferred form of monitor unit includes a yarn-sensor circuit Y, a needle-detector circuit N, a timer circuit T, a selector switch S, and a display D. The several components are mounted in any suitable casing for transport between knitting machines.
The yarn-sensor circuit Y includes a suitable yarn-engaging unit 10 which emits a fixed number of pulses per unit length of the travelling yarn it engages. The yarn-engaging unit 10 may be of any of several types, as may be desired. Most conveniently, the unit 10 includes a pulley 11, which is simply presented against the running yarn. The pulley has a reflective face carrying two diametrically-opposed, non-reflective black marks. Light from a bulb and reflected toward a photodiode (not shown) thus provides two pulses for each revolution of the pulley. The pulses from the unit 10 are supplied, via a suitable amplifier 14, to a divider 15.
Ideally, the pulley circumference engaging the yarn is 33.333 mm, so that three revolutions of the pulley (over a 100 mm length of the yarn) will provide 6 pulses per meter of yarn. This pulse rate per unit of yarn length is especially advantageous, as will be discussed hereinafter regarding operation of the monitor unit.
The divider 15 is connected to a contract y1 in the switch assembly S. A branch line 16 bypasses the divider 15 and is connected to a contact y2 in the switch.
The needle-detector circuit N includes a detector 17 which emits pulses, via a suitable amplifier 18, to a selective counter 19. Preferably, the detector 17 is a tunable stroboscope or a suitable optoelectronic unit employing fiber optics and avoiding contact with the needles.
The counter 19 is connected to two contacts n1 and n3 in the switch assembly S. Preferably, the counter is set for 100, with one pulse being emitted for each needle, or a duration of 100 needles if the pulse rate is other than one per needle.
The timer circuit T includes a time signal generator 20, preferably of the quartz crystal type, and a divider 21 to provide a signal duration of one second at contacts t2 and t3 in the switch assembly S.
The switch assembly S includes a moveable arm 22 carrying a pair of contacts 23 and 24 in communication with a gate 25. The output of the gate 25 is supplied to the numerical display unit D.
OPERATION OF THE PREFERRED EMBODIMENT
When it is desired to compare the yarn length consumed to the selected number of stitches, the switch is positioned as shown in the drawing with contact 23 closing on contact y 1 and gate-control contact 24 closing on contact n1. The monitor is then presented to the machine to be monitored, with the pulley 11 in driving contact with the yarn and the needle detector 17 associated with the needle bank. Yarn pulses are then delivered via the amplifier 14, divider 15 and the gate 25 for the duration of 100 stitches, as gauged by the passage of 100 needles.
The needle pulses are delivered via the amplifier to the counter, which is set to hold the gate 25 open for that count. Upon closing of the gate 25, the total displayed on the display unit may be read directly as millimeters per 100 stitches, in view of the 33.333 mm pulley, the two pulses per rpm and the "6" divider 15. Other ratios may be provided, however, if it is desired.
However, the preferred relationship is of advantage when it is desired to monitor the linear yarn speed alone. The switch is then moved to engage contacts y2 and t2, to provide yarn pulses through the gate under control of the signal of the frequency meter and divider via contacts t2 and 24.
Since the pulley makes three revolutions per meter of yarn, a yarn speed of 100 meters/mm will provide 6000 pulses per minute to the branch line 16 and the contact y2 and 23 to he gate and counter display D. With the frequency meter circuit set for a duration of one second, the yarn speed is then directly displayed in meters/min.
When it is desired to determine the rotary speed of the knitting machine, the switch is moved to close with contacts n3 and t3. With the stroboscope tuned to the rate of passage of the needles and the frequency meter duration remaining at one second, the rpm of the machine may be calculated with the formula: ##EQU1##
The duration of the count, as governed by the frequency meter, may be selected for a period other than 1 second. The formula would then require a corresonding adjustment.
Therefore, it is apparent that the present invention provides a particularly advantageous monitor unit which is both portable and versatile and which will provide a full operating check of several machines in succession. This is accomplished without the need for complication of each of the several knitting machines with components useful only for the monitoring procedure.
Various changes may be made in the details of the invention, as disclosed, without sacrificing the advantages thereof or departing from the scope of the appended claims. | A portable monitor unit for knitting machines and particularly suitable for circular knitting machines including a yarn speed sensor pulsing a numeral display counter via a gate, a needle detector controlling the gate via a settable counter, a frequency meter, and a switch for selectively engaging the signals of the yarn sensor, needle detector and frequency meter to display yarn length per needle stitch, yarn length per unit time, and rpm of the knitting machine. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a curb forming apparatus and, more particularly, to such an apparatus which travels along a single horizontal longitudinal form and pavement surface.
2. Description of the Prior Art
Numerous concrete and asphalt handling machines have been developed over the years to lay a continuous stretch of curbing. These prior art machines are usually large self-propelled units which travel across the surface of an already-laid pavement. These units are impractical for use on smaller operations, therefore, numerous smaller machines have been developed. Oftentimes, however, a municipal ordinance or statute mandates that immediately after a pavement has been laid and while still wet, the curbing should be laid thereon. These prior art machines are incapable of forming a curb on a still wet pavement without destroying the surface of the pavement. Also, these prior art machines usually require the use of "zero-slump" or "one inch-slump" concrete mix to operate efficiently. This concrete mix cures very rapidly and is hard to work when finsihing.
Other curb forming machines have been developed to ride along two parallel strings of forms. These machines are used to lay a curb before a pavement has been laid. These machines may not be used if the municipality has an ordinance or statute of the type noted above. Further, the operation of these machines is time consuming in that two strings of forms have to be laid and disassembled.
SUMMARY OF THE INVENTION
The present invention generally provides a curb forming apparatus which travels along a single horizontal longitudinal form and pavement surface. The curb forming apparatus is small, lightweight and easily operated by a single individual. The apparatus is designed to lay a curb upon a still wet pavement without destroying the non-hardened surface thereof. Further, this apparatus is capable of using "one-inch slump" to "three-inch slump" concrete mix, thereby allowing greater workability and finishability of the curb.
The present invention, more particularly, comprises a frame having a front, rear and a first and second side members. A plurality of aligned wheels are mounted to the first side member for traveling upon the single horizontal form. A curb forming chute is mounted within the frame adjacent the first side member and is adapted to slide against the form and the pavement. A hopper is mounted to the frame above the chute and is provided with an opening in the lower portion thereof which is in communication with the chute. A skid plate is attached to a second of the side members and is adapted to slide along the surface of the pavement. An electric or internal combustion engine is provided to propel the apparatus along the form.
The lower portion of the chute is removable and different configured lower portions are attachable to this chute to form different curb designs. The hopper and the skid plate provided with devices to universally adjust the level thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right side elevational view of a curb forming apparatus embodying the present invention.
FIG. 2 is a top plan view of the apparatus.
FIG. 3 is a left side elevational view of the apparatus.
FIG. 4 is a rear elevational view of the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, reference character 10 generally indicates a curb forming apparatus particularly designed to lay a continuous length of curb on top of a street pavement or other similar pavement. As shown in FIGS. 1 and 2, the curb forming apparatus 10 is formed by a rectangular frame having a right hand side member 12, a left hand side member 14, a front member 16, and a rear member 18. A first brace 20 is spaced between the right member 12 and left member 14 and adjacent the front member 16. A second brace 22 is spaced between the right member 12 and the left member 14 adjacent the rear member 18. A short diagonal brace 24 extends from the center of the second brace 22 to the right member 12.
A material handling hopper 26 is attached to the braces 20 and 24 and the left member 14 by means of elongated bolts 28, with nuts 30 threaded to the top thereto, which pass through a plurality of brackets 32, which are attached to the sides of the hopper 26. As shown in FIG. 2, an opening 34 is spaced in the lower portion of the hopper 26. Attached to and below the hopper 26 is an elongated curb forming chute 36, which is in communication with the opening 34 in the hopper 26 and which extends towards the rear of the apparatus 10. As shown in FIG. 3, an elongated lower portion 35 of the chute 36 on the left side thereof, is cut away to form an opening 38. As best seen in FIG. 4, the apparatus 10 is designed to move along a pavement edge form 40 which rises a short distance above the level of the surface of a pavement 42 with the lower portion 35 of the chute 36 abutting against the form 40. A double flanged wheel 44 is pivotally mounted between a pair of brackets 45 which extend downward from the left member 14 and a short parallel front brace 46, which is spaced between the front member 16 and the first brace 20. The wheel 44 is adapted to travel along the top edge of the form 40. A wheel 48 with a single flange 50 on the outside edge thereof, is pivotally mounted between a pair of brackets 51 which extend downward from a short parallel rear brace 52, which is spaced between the rear member 18 in the second brace 22 and the left member 14. The wheel 48 is adapted to travel along the top edge of the form 40.
A rectangular horizontal plate or skid 54, with a raised front lip 56, is attached to the apparatus 10 and is adapted to slide along the surface of the pavement 42. The skid 54 is attached to the apparatus 10 by means of a plurality of vertical elongated bolts 58 which extend upwardly from the approximate corners of the skid 54 through a plurality of brackets 60, which are attached to the first and second braces 20 and 22 and are secured thereto by means of a plurality of nuts 62.
The apparatus 10 is drawn across the surface of the pavement 42 by a powered winch means 64. The winch means 64 is comprised of an electrical motor 66 connected to a right angle drive mechanism (not shown) within a housing 68, which is mounted to the second brace 22 in the rear member 18 approximately along the center line of the apparatus 10. A pulley 70 is attached to a shaft 72, which extends from the right angle drive mechanism. A winch 74 is mounted on top of a plurality of brackets 76, which are in turn mounted to the top surface of the housing 68. A pulley 78 is mounted to the shaft 80 which extends from the winch 74.
A continuous belt 82 is positioned around the pulleys 70 and 78 and transmit power from the motor 66 to the winch 74. A pivotally mounted idler pulley 84 is mounted to one of the brackets 76 and maintains tension on the belt 82. A cable 86 extends from a spool 88, which is mounted within the winch 74, downward through a pulley block 90, which is mounted to the underside of the second brace 22, and extends forwardly therefrom to a fixed object (not shown) a certain distance along the form 40. When the motor 66 is connected to a source of electrical power (not shown), the winch 74 rewinds the cable 86 thereby propelling the apparatus 10 forwardly along the form 40 and pavement 42. An internal combustion engine may be used in place of the electric motor 66, and then the idler pulley 84 would provide a clutch means for the winch 74.
To make a run of curbing, the apparatus 10 is placed on top of the still wet pavement 42 with the wheels 44 and 48 engaging the top edge of the form 40. The cable 86 is unwound from the winch 74 and is extended, usually 150' and attached to a stationary object, such as a post or the like, along the form 40. The motor 66 is connected to a source of electrical power, such as a small electrical generating unit carried within a vehicle (not shown) which travels alongside the pavement 42. Concrete mix (not shown) is poured into the hopper 26 and flows into the chute 36 to the opening 38. As the apparatus 10 is moving forward the weight of the concrete within the hopper 26 causes concrete to be extruded from the chute 36 in the shape of a curb 91. As can be seen in FIG. 2, the majority of the weight of the apparatus 10 is placed on the wheels 44 and 48 thereby allowing the skid 54 to slide along the surface of the pavement 42 without grooving or destroying the surface thereof.
A majority of the prior art curb formig apparatuses require the use of 0" to 1" slump concrete mix. This concrete mixture cures very quickly and is hard to finish in the event that there are any gaps or depressions that need to be smoothed over. The apparatus 10 works equally well with 0" to 3" slump concrete mix. The use of 3" slump mix is desired for its easy workability and finishability as we as that it flows more easily from the hopper 26 through the chute 36.
A concrete vibrator 92 extends through an opening 94 in the front portion of the hopper 26. The vibrator 92 may either be powered by a small internal combustion motor or by an electric motor, which is to be connected to the same source of electrical power as the winch motor 66. The vibrator 92 provides a roddening action to the concrete mix and thereby ensures the continuous flow of the concrete mix from the hopper 26 through the chute 36 and through the opening 38.
Oftentimes, when the pavement 42 is laid gravel, dirt and concrete may be deposited upon the top surface of the form 40. A flexible wiper blade 96 is attached to the apparatus 10 in front of each wheels 44 and 48 to clear this debris from the top of the form 40 thereby ensuring the smooth formation of the curb 91. Due to the fact that the form 40 extends above the surface of the pavement 42 at different heights from job to job, the height and tilt angle, either side to side or front to rear, of the hopper 26 and skid 54 are adjustable by means of adjusting the nuts 30 on the elongated bolts 28 for the hopper 26 and adjusting the nuts 62 on the bolts 58 for the skid 54.
To enable the apparatus 10 to properly lay a curb 91 while negotiating a curve in the pavement 42, the rear portion 35 of the chute 36 is yieldably maintained against the form 40 by means of a sliding rod 98, which is attached to a lug 100 extending upwardly from the lower portion of the chute 35. The rod 98 slides over an inner rod 101 with one end of which being mounted to a frame 102, which extends from the underside of the second brace 22. A spring 104 is spaced around the rod 101 and acts upon a collar 106, which is attached to the end of the rod 98, thereby maintaining the rear portion 35 of the chute 36 against the form 40. The apparatus 10 is further provided with a vertical bar 107, which is attached to the underside of the rear member 18 and to the top surface of the lower portion 35 of the chute 36. The bar 107 prevents the lower portion 35 of the chute 36 from flexing upwards. When the apparatus 10 negotiates a right hand curve, the wheel 48 will be slightly displaced to the left on the form 40 and the rear 35 of the chute 36 will be displaced a partial distance to the right compressing the spring 104. When the apparatus 10 negotiates a left hand curve, the rear portion 35 of the chute 36 is maintained in contact with the form 40 by means of the spring 104.
Due to the fact that there are a vast number of different curb shapes, many of which being specifically re-required by municipal statutes or ordinances, the apparatus 10 is provided with means to attach interchangeable curb forms 108 of different shapes which are connected to the rear portion 35 of the chute 36. Each curb form 108 is provided with a plurality of elongated members 110 which extend a partial distance forward against the side edge of the lower portion 35 of the chute 36. A plurality of clamps 112 connect the form 108 to the chute 36 thereby providing, in combination with the members 110, a rigid connection between the form 108 and the chute 36.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications of the invention, apart from those shown or suggested herein, may be made within the scope and spirit of this invention. | A curb forming apparatus for traveling along a single horizontal longitudinal form adjacent a side edge of a pavement comprising, in combination, a frame with a plurality of aligned wheels for traveling upon said form, a curb forming chute mounted within said frame and being adapted to slide along said pavement, a hopper mounted to said frame and in communication with said chute, a skid plate attached to said frame and being adapted to slide upon said pavement, and a propulsion means to propel said apparatus along said form. | 4 |
DESCRIPTION
This invention relates to pyridoindole derivatives useful in therapy.
The pyridoindole derivatives provided by this invention are in the form of racemates or optically active isomers, and are compounds of the formula ##STR2## in which n is 0 or 1, R 1 represents a hydrogen or halogen atom, an alkyl or alkoxy radical or the group CF 3 , R 2 represents either an alkoxycarbonyl radical or a radical CONHR 5 , in which R 5 is an alkyl, cycloalkyl or benzyl radical, a phenyl radical which can carry a substituent, or a hydrogen atom, R 3 is a hydrogen atom, an alkyl radical or an alkoxycarbonyl radical and R 4 is either a hydrogen atom or an acyl radical or an alkyl radical or a radical CONHR 6 , in which R 6 is a hydrogen atom or an alkyl, cycloalkyl, benzyl, phenyl or substituted phenyl radical, the alkyl and alkoxy radicals having from 1 to 4 carbon atoms and the cycloalkyl radicals having from 3 to 6 carbon atoms, with the exception of the compounds wherein simultaneously n=0, R 1 =H, R 2 =COO(Et or Me), R 3 =H or CH 3 and R 4 =H, or n=1, R 1 =H, R 2 =COOC 2 H 5 , R 3 =H or CH 3 and R 4 =H, or n=1, R 1 =H, R 2 =CONHCH 3 , R 3 =H and R 4 =H, but including pharmaceutically acceptable acid addition salts of the above-defined compounds of formula (I).
The pyridoindole derivatives are herein referred to for brevity as the "therapeutic compounds".
Preferred therapeutic compounds are those in which R 1 is H, Cl, F, CH 3 , CH 3 O, CF 3 or Br, R 2 is COOCH 3 , COOC 2 H 5 , CONHCH 3 or CONHC 2 H 5 , R 3 is H, CH 3 or COOC 2 H 5 , R 4 is H, CH 3 , CONH 2 , CONalkyl or COCH 3 and n is 0 or 1, subject to the above-mentioned exception clause.
Examples of specifically preferred therapeutic compounds of formula (I) are given in a Table hereinafter and this Table should be construed as extending to the free bases and all pharmaceutically acceptable salts of the free bases.
The invention provides processes for the preparation of the compounds as follows:
1. a process for the preparation of a derivative defined above in which R 3 is an alkyl or alkoxycarbonyl radical, which process comprises reacting a compound of the formula ##STR3## R 1 being as defined above, with a compound of formula R 3 CO(CH 2 ) n COOalkyl, R 3 being as defined above, and the resulting compound (I), in which R 2 is COOalkyl and R 4 is a hydrogen atom of the formula ##STR4## and if desired this compound is reacted with an amine R 5 NH 2 to give the compounds (I) in which R 2 is CONHR 5 , and if desired the resultant compound or compound (B) is reacted with an isocyanate R 6 NCO to give the compounds (I) in which R 4 is CONHR 6 , R 6 being other than a hydrogen atom or with an alkali metal cyanate to give the compounds (I) in which R 6 is a hydrogen atom or is N-acylated or N-alkylated by a compound of formula acyl-L or alkyl-L, L representing a leaving group for the reaction, to give the compounds (I) in which R 4 is alkyl or acyl, the radicals n, R 1 , R 3 , R 4 , R 5 and R 6 having the meanings as defined above, and if desired a free base of formula (I) thus obtained is converted into a pharmaceutically acceptable acid addition salt thereof;
2. a process for the preparation of a derivative defined above in which R 3 is a hydrogen atom and n is 1, which process comprises reacting a compound of the formula (A') ##STR5## R 1 being as defined above, with the compound EtO--CO--CO--CH 2 --COOC 2 H 5 , saponifying the resulting diester of formula (B') ##STR6## R 1 being as defined above, reacting the resulting diacid with an alcohol of formula alkyl-OH to give a compound (I) in which R 2 is COOalkyl and R 3 is a hydrogen atom, R 2 and R 3 being as defined above, and, if desired, reacting this compound in the manner defined for reaction of compound (B) above and if desired a free base of formula (I) thus obtained is converted into a pharmaceutically acceptable acid addition salt thereof;
3. A process for preparing a derivative defined above in which R 2 is CONHR 5 from a compound defined above in which R 2 is an alkoxycarbonyl radical and/or a compound defined above in which R 4 is CONHR 6 , alkyl or acyl from a compound defined above in which R 4 is a hydrogen atom, which comprises reacting the said starting compound with an amine R 5 NH 2 , isocyanate R 6 NCO, R 6 being other than a hydrogen atom, alkali metal cyanate or compound of formula acyl-L or alkyl-L, L being a leaving group for the reaction, respectively, R 5 and R 6 being as defined above and if desired converting a free base of a formula (I) into a pharmaceutically acceptable acid addition salt thereof.
In all the above processes "L" in "alkyl-L" is preferably anion-forming and acyl-L is conveniently a dianhydride of formula (acyl) 2 O.
By way of illustration of the processes of the invention, the compounds (I) can be prepared in accordance with the following reaction scheme. "ALK" is alkyl and the other symbols as defined above for formula (I) except where otherwise indicated. ##STR7##
The conversion of the ester (I) into the amide (I) in which R 2 =CONHR 5 is effected in the same manner as in reaction scheme 1; likewise, the addition of the radical R 4 =CONHR 6 onto the compounds (I) in which R 2 =COOalk or CONHR 5 is effected in the same manner as in scheme 1.
Alternatively the compounds (I) in which R 1 is CF 3 or Br can be prepared in accordance with a somewhat different process (see Example 8) adapted from the process described for R 1 =H in Chem. Abstracts, 60, 5471h.
The compounds in which R 3 =H and n=0 can be obtained in accordance with the method of preparation described by Z. J. Vejdelek et al., J. of Med. and Pharm. Chem., Volume 3, No. 3 (1961), pages 427-440.
The following examples illustrate the invention. The microanalyses and the IR and NMR spectra confirm the structure of the compounds.
EXAMPLE 1
Ethyl 6-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate
[n=1, R 1 =6--CH 3 , R 2 =COOC 2 H 5 , R 3 =H, R 4 =H]
1. 52.62 g (0.25 mol) of 5-methyltryptamine hydrochloride are suspended in 250 ml of ethanol and the suspension is heated to the reflux temperature. 57.75 g of 3-ethoxycarbonyl-1,2-dioxo-1-ethoxypropane are suspended in 250 ml of ethanol, and 25 ml of concentrated hydrochloric acid are added dropwise in the course of 10 minutes. The latter suspension is added to the suspension of 5-methyltryptamine HCl, kept at the reflux temperature. The mixture is allowed to cool overnight. The solvent is removed by evaporation, the residue is dissolved in 400 ml of water and the solution is rendered alkaline with ammonia. After extraction with ethyl acetate, an oil is obtained which is chromatographed on a silica column. After elution with an 8/2 mixture of chloroform and ethanol, an oil is obtained which solidifies on trituration with petroleum ether. After recrystallisation from hexane, the compound obtained ##STR8## melts at 102°-103° C.
2. 45 g of the preceding compound are heated under reflux in 450 ml of a 10% strength aqueous solution of NaOH for 20 hours. Concentrated hydrochloric acid (100 ml) is added dropwise to the cooled reaction mixture in the course of 30 minutes. The resulting solid is filtered off and dried over P 2 O 5 .
3. 99.6 g of the crude solid obtained above are heated under reflux in a mixture of 250 ml of ethanol and 20 ml of concentrated sulphuric acid for 9 hours. The mixture is left to stand overnight. The ethanol is removed by evaporation and the residual solid is rendered alkaline with ammonia. The basic solution is extracted with 3 times 300 ml of ethyl acetate. The extract is evaporated. An oil is obtained which gives a white solid on trituration with petroleum ether. The solid is filtered off and dried.
After recrystallisation from hexane, the compound obtained melts at 103° C.
EXAMPLE 2
Methyl 6-chloro-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-carboxylate
[n=0, R 1 =6--Cl, R 2 =COOCH 3 , R 3 =CH 3 , R 4 =H]
A solution of 36.1 g (0.156 mol) of 5-chlorotryptamine hydrochloride in 350 ml of methanol is reacted with 20 g of methyl pyruvate. The mixture is stirred for one week at ambient temperature. The methanol is driven off on a rotary evaporator. The residue is taken up in ethyl acetate. The mixture is stirred for 15 minutes and the precipitate is then filtered off. The precipitate is treated with a saturated solution of sodium bicarbonate and extraction is carried out with ethyl acetate. An insoluble material is removed by filtration. The organic solution is decanted, washed, dried and evaporated on a water bath in vacuo.
The oily residue crystallises after a few days. After recrystallisation from toluene, the compound melts at 148° C.
EXAMPLE 3
Ethyl 1-methyl-2-methylaminocarbonyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate
[n=1, R 1 =H, R 2 =COOC 2 H 5 , R 3 =CH 3 , R 4 =CONHCH 3 ]
10.9 g (0.04 mol) of ethyl 1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate are suspended in 200 ml of cyclohexane. 3 ml (0.04 mol) of methyl isocyanate are added. The mixture is heated under reflux for 1 hour. It is allowed to cool overnight in a refrigerator. The precipitate is filtered off. The product is recrystallised from ethanol.
Melting point=217° C.
EXAMPLE 4
Ethyl 2-aminocarbonyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-carboxylate
[n=0, R 1 =H, R 2 =COOC 2 H 5 , R 3 =H, R 4 =CONH 2 ]
56.2 g (0.2 mol) of ethyl 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-carboxylate are heated to about 60° C. in 1,000 ml of water. A solution of 15.2 g (0.234 mol) of pulverulent sodium cyanate in 200 ml of water is added all at once. The mixture is stirred for 15 minutes and then cooled to about 10° C. The aqueous reaction phase is decanted and the compound is washed with water and recrystallised from ethanol.
Melting point=215°-217° C.
EXAMPLE 5
1-Methyl-1-methylaminocarbonyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole
[n=0, R 1 =H, R 2 =CONHCH 3 , R 3 =CH 3 , R 4 =H]
4.8 g (0.02 mol) of methyl 1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-carboxylate are dissolved in 100 ml of ethanol saturated with methylamine. The solution is left at ambient temperature for 48 hours. The solvent is removed and the residue is then taken up in 20 ml of ethanol. The product is filtered off and washed with ethanol.
Melting point=230°-231° C.
EXAMPLE 6
6-Fluoro-1-methylaminocarbonyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole
]n=1, R 1 =6-F, R 2 =CONHCH 3 , R 3 =H, R 4 =H]
20 g of ethyl 6-fluoro-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate (obtained in accordance with the process of Example 1) and 500 ml of ethanol saturated with methylamine are placed in an autoclave.
The autoclave is heated at 100° C. for 5 hours. The solvent is driven off and a white solid is obtained. It is recrystallised from ethanol.
Melting point=227° C.
EXAMPLE 7
6-Chloro-1-methylaminocarbonyl-1-methyl-2-acetyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole
[n=1, R 1 =6-Cl, R 2 =CONHCH 3 , R 3 =CH 3 , R 4 =COCH 3 ]
3 g (0.0102 mol) of 6-chloro-1-methylaminocarbonyl-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole are dissolved in 30 ml of pyridine. 2 ml of acetic anhydride are added. The mixture is stirred at ambient temperature for 48 hours. It is evaporated and the pyridine is driven off. The residue is taken up in 20 ml of ethanol and the precipitate is filtered off. After recrystallisation from ethanol, the product melts at 214° C.
EXAMPLE 8
Ethyl 6-trifluoromethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate
[n=1, R 1 =6-CF 3 , R 2 =COOC 2 H 5 , R 3 =H, R 4 =H]
The reaction scheme is as follows: ##STR9##
(1) 42.75 g (0.25 mol) of 3-ethoxycarbonylpyrid-2-one are placed in a round-bottomed flask and 500 ml of water are added. 15 g of KOH are added and the mixture is stirred at ambient temperature for 24 hours.
(2) A solution of 4-trifluoromethylaniline (42.25 g) in water (250 ml) and concentrated hydrochloric acid (55 ml) is reacted with 18.75 g of NaNO 2 in 125 ml of water, at a temperature of 0° to 5° C. 50 g of CH 3 COONa in 125 ml of water are then added.
(3) The compound obtained under 2 is added, in the course of 10 minutes, at 0°-5° C., to the compound obtained under 1. The mixture is stirred for 5 minutes. 75 ml of acetic acid are added. The mixture is stirred for 4 hours at ambient temperature. The product is filtered off and recrystallised from ethanol.
(4) 30 g of the compound ##STR10## are placed in a round-bottomed flask and 135 ml of glacial acetic acid and 68 ml of hydrochloric acid are added. The mixture is heated at the reflux temperature for 1 hour. The reaction mixture is cooled and poured onto 300 ml of ice. The resulting solid is recrystallised from ethanol.
(5) 15 g of 6-trifluoromethyl-1-oxo-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole are placed in a round-bottomed flask and 50 ml of POCl 3 are added. The mixture is stirred at ambient temperature for 24 hours. 60 ml of ethyl ether are added and the product is filtered off. It is washed with 20 ml of ethyl ether and dried in vacuo over P 2 O 5 for 2 hours.
60 ml of methanol are placed in a round-bottomed flask and cooled to 0° C. 18.3 g of the compound obtained above are added in portions. The mixture is stirred at ambient temperature for 1 hour. Ethyl ether is added and a precipitate is obtained. After washing the compound, a white product (6) is obtained which melts at 220° C.
(6) 8.5 g of this compound are placed in a round-bottomed flask and 25 ml of ethyl acetoacetate are added. The mixture is heated under nitrogen at 140° C. for 8 hours. The reaction mixture is left to stand overnight. After washing, draining and drying, compound (7) is obtained, which melts at 144° C.
(7) 7.5 g of compound (7) are placed in a round-bottomed flask and 30 ml of ethanol are added. A solution of NaOH (1.25 g) in water (30 ml) is added. The mixture is heated at the reflux temperature for 1 hour. It is cooled in an ice bath. After it has been filtered off and dried in vacuo over P 2 O 5 , compound (8) melts at 192° C.
(8) 5.2 g of compound (8), 13 ml of acetic acid and 50 ml of ethanol are placed in an autoclave. 0.43 g of platinum oxide is added and the mixture is stirred under hydrogen for 1 and a half hours under pressure. The mixture is filtered and the ethanol is driven off. The residue is rendered alkaline with NH 4 OH and the solid is extracted with 4 times 100 ml of ethyl acetate. After drying, an oil is obtained which solidifies. After recrystallisation from ethanol, compound (I) melts at 140° C.
The therapeutic compounds, prepared by way of examples, are shown in the following table.
TABLE__________________________________________________________________________ ##STR11## Melting pointCompound R.sub.1 R.sub.2 R.sub.3 R.sub.4 n (°C.)__________________________________________________________________________1 (Exam- 6-CH.sub.3 COOC.sub.2 H.sub.5 H H 1 103ple 1)2 6-CH.sub.3 COOC.sub.2 H.sub.5 COOC.sub.2 H.sub.5 H 1 102-1033 6-CH.sub.3 O COOC.sub.2 H.sub.5 H H 1 181 (maleate)4 6-CH.sub.3 O COOC.sub.2 H.sub.5 COOC.sub.2 H.sub.5 H 1 1005 H COOC.sub.2 H.sub.5 COOC.sub.2 H.sub.5 H 1 80-826 6-Cl COOC.sub.2 H.sub.5 CH.sub.3 H 1 1047 6-Cl COOC.sub.2 H.sub.5 H H 1 240 m.s8 6-Cl COOC.sub.2 H.sub.5 COOC.sub.2 H.sub.5 H 1 1019 6-F COOC.sub.2 H.sub.5 H H 1 229-230 m.s10 6-F COOC.sub.2 H.sub.5 COOC.sub.2 H.sub.5 H 1 197 HCl11 (Exam- 6-Cl COOCH.sub.3 CH.sub.3 H 0 148ple 2)12 H COOC.sub.2 H.sub.5 H CONH.sub.2 1 Oil13 (Exam- H COOC.sub.2 H.sub.5 CH.sub.3 CONHCH.sub.3 1 217ple 3)14 (Exam- H COOC.sub.2 H.sub.5 H CONH.sub.2 0 215-217ple 4)15 H COOC.sub.2 H.sub.5 H CONHC.sub.2 H.sub.5 0 190-19216 H COOC.sub.2 H.sub.5 H CONHC.sub.3 H.sub.7n 0 170-17517 H COOC.sub.2 H.sub.5 H CONHC.sub.4 H.sub.9t 0 209-21018 H COOC.sub.2 H.sub.5 H CONHCH.sub.3 0 158-16219 H COOC.sub.2 H.sub.5 H CONHC.sub.3 H.sub.7i 0 145-15020 H COOC.sub.2 H.sub.5 H CONHC.sub.6 H.sub.5 0 164-16821 H COOC.sub.2 H.sub.5 H ##STR12## 0 16022 H COOC.sub.2 H.sub.5 H CONHC.sub.4 H.sub.9n 0 14023 6-CF.sub.3 COOC.sub.2 H.sub.5 H H 1 14024 6-Br COOC.sub.2 H.sub.5 H H 1 Oil25 H COOC.sub.2 H.sub.5 CH.sub.3 COCH.sub.3 1 19426 H COOCH.sub.3 CH.sub.3 COCH.sub.3 0 23827 H COOC.sub.2 H.sub.5 H COCH.sub.3 0 211-21228 6-F COOCH.sub.3 CH.sub.3 H 0 24829 6-CH.sub.3 COOCH.sub.3 CH.sub.3 H 0 14230 H CONHCH.sub.3 CH.sub.3 H 1 18231 6-Cl CONHCH.sub.3 CH.sub.3 H 1 21232 H ##STR13## H H 1 16033 H ##STR14## H H 1 166-16834 (Exam- 6-F CONHCH.sub.3 H H 1 227ple 6)35 6-Cl CONHCH.sub.3 H H 1 232-23336 6-CH.sub.3 CONHCH.sub.3 H H 1 21637 6-CH.sub.3 O CONHCH.sub.3 H H 1 19038 H CONHC.sub.2 H.sub.5 H H 1 148-14939 H CONHCH.sub.3 CH.sub.3 CH.sub.3 1 24040 (Exam- H CONHCH.sub.3 CH.sub.3 H 0 230ple 5)41 H CONHCH.sub.3 CH.sub.3 CH.sub.3 0 20742 6-Cl CONHCH.sub.3 CH.sub.3 H 0 23043 6-F CONHCH.sub.3 CH.sub.3 H 0 23844 (Exam- 6-Cl CONHCH.sub.3 CH.sub.3 COCH.sub.3 1 214ple 7)45 6-Cl CONHCH.sub.3 CH.sub.3 COCH.sub.3 0 28046 6-Cl CONHC.sub.2 H.sub.5 H H 1 24047 6-Cl ##STR15## H H 1 24248 6-Cl CONHCH.sub.3 CH.sub.3 COCH.sub.3 1 21449 6-Cl CONHCH.sub.3 H COCH.sub.3 1 26750 H ##STR16## H H 1 18951 H CONHC.sub.2 H.sub.5 CH.sub.3 H 0 15952 H ##STR17## CH.sub.3 H 0 16453 6-Cl CONHCH.sub.3 CH.sub.3 COCH.sub.3 0 28054 6-CH.sub.3 CONHCH.sub.3 CH.sub.3 H 0 21455 H CONHCH.sub.3 H H 0 15856 H CONH.sub.2 H H 1 198-20057 H CONHCH.sub.3 H H 0 158__________________________________________________________________________ HCl = hydrochloride m.s = methanesulphonate
The therapeutic compounds were subjected to various pharmacological experiments.
In fact, the compounds were subjected to the test for the anoxia caused in mice by pressure reduction and to the test for the antagonism towards the ptosis induced by reserpine (C. Gouret et al., J. Pharmacol. (Paris) 8, 333-350 (1977)).
ANOXIA CAUSED BY PRESSURE REDUCTION
Mice of the CDl strain are kept in an oxygen-depleted atmosphere produced by creating a partial vacuum (190 mm of mercury, corresponding to 5.25% of oxygen).
The survival time of the animals is noted. This time is increased by agents which are capable of assisting the oxygenation of tissues and in particular of the brain. The compounds studied are administered intraperitoneally in several doses, 10 minutes before the experiment. The percentage increases in the survival time, relative to the values obtained for control animals, are calculated. The mean active dose (MAD), that is to say the dose which increases the survival time by 100%, is determined graphically.
The MAD of the therapeutic compounds varies from 13 to 26 mg/kg, administered intraperitoneally.
ANTI-DEPRESSIVE ACTIVITY
The anti-depressive activity was determined by the test for the antagonism towards the ptosis induced by reserpine (C. Gouret et al., J. Pharmacol. (Paris) 8, 333-350 (1977)).
Mice (male, CDl Charles River, France, weighing 18-22 g) simultaneously receive the products to be studied or the solvent (administered intraperitoneally) and the reserpine (4 mg/kg, administered subcutaneously).
After sixty minutes, the degree of palpebral ptosis is assessed for each mouse by means of a rating scale (0 to 4).
The mean rating and the percentage variation relative to the control batch are calculated for each dose.
For each product, the AD 50 , namely the dose which reduces the mean ptosis score by 50%, relative to the control animals, is determined graphically.
The AD 50 varies from 2 to 10 mg/kg, administered intraperitoneally.
ACTION OF THE DURATION OF "SLEEP"
This action was determined by the influence of the compounds on the duration of the "sleep" induced in curarised rats by sodium 4-hydroxybutyrate (GHB); the rats are under artificial respiration and their electrocorticographic activity is recorded by means of cortical electrodes.
The compounds of the invention reduce the total duration of the sleep by 20 to 35%.
The pharmacological study of the therapeutic compounds shows that they are active in the test for the anoxia caused in mice by pressure reduction, whilst being only slightly toxic, and that they exert a significant waking action in the test for the "sleep" induced by sodium 4-hydroxybutyrate.
The therapeutic compounds, which possess both an anti-anoxia action and a psychotropic action, can be used in therapy for the treatment of vigilance disorders, in particular for combating behavioural disorders which can be attributed to cerebral vascular damage and to cerebral sclerosis encountered in geriatrics, and also for the treatment of epileptic vertigo due to cranial traumatisms, and the treatment of depressive states.
The therapeutic compounds can be formulated in pharmaceutical compositions containing the compounds and/or their salts as active principles, in association with any excipients which are suitable for their administration, in particular their oral or parenteral administration.
The methods of administration can be oral and parenteral.
The daily posology can range from 10 to 1,000 mg. | Pyridoindole derivatives of formula ##STR1## n=0 or 1; R 1 =H, Hal, alk, alk-O-, CF 3 ; R 2 =--COOalk; --CONHR 5 (R 5 =H or various substituents); R 3 =H, alk, --COOalk; R 4 =H, Ac, alk, --CONHR 6 (R 6 =H or various substituents), and acid addition salts, except certain known compounds, are useful in treating anoxia and depression and in psychotropic therapy. They are prepared from tryptamine or a derivative thereof by reaction thereof with a pyruvic ester or 3-ethoxycarbonyl-1,2-dioxo-1-ethoxypropane to form compounds in which R 4 is H and R 2 is --COOalk. These compounds are reacted with amines, isocyanates or usual N-acylating or N-alkylating reagents to prepare the other compounds. | 2 |
The invention relates to a microorganism, Escherichia coli K-12, and more particularly to transforming the microorganism by a recombinant DNA plasmid.
BACKGROUND OF THE INVENTION
The fermentative production of tryptophan by microorganisms from inexpensive carbohydrates is highly desirable. The production of tryptophan by using artificially mutated microorganisms has been known for some time. Classically mutated microbes for tryptophan production include Brevibacterium (described in U.S. Pat. No. 3,700,536), Corynebacterium (ATCC 21851), Bacillus subtilis (described in U.S. Pat. No. 4,363,875), and Enterobacter (described in U.S. Pat. No. 4,439,627).
The use of recombinant DNA technology for the construction of microorganisms for production of tryptophan has been described. These descriptions include Corynebacterium or Brevibacterium (described in U.S. Pat. No. 5,447,857) and Bacillus (described in U.S. Pat. No. 4,588,687). The use of recombinant DNA techniques for the construction of E. coli strains for tryptophan production has also been described in U.S. Pat. No. 4,371,614. In this patent, the maximum production of tryptophan is about 230 ppm or 230 mg/l. However, this amount of tryptophan production is too low for a commercially feasible production strain.
Work to improve tryptophan production was described in (WO 87/01130) and in Applied and Environmental Microbiology (1991) 57: 2995-2999. These documents describe a two plasmid system developed by Stauffer Chemical Co. containing a feedback resistant AS gene (trpE) isolated from Serratia marcessens and a feedback resistant DS gene (aroG) from E. coli. These plasmids also contained the rest of the trp operon trpDCDA from E. coli coding for the APRT, PRAI, InGPS and TS enzymes respectively. One of the plasmids also contained the serA gene used to maintain the plasmid. It is believed that the overexpression of the serA gene product may increase serine concentration in the cell. Serine is one of the precursors of tryptophan. These documents also describe the use of the lacUV5 promoter to control the DS gene and the trpDCBA genes. The maximum production of tryptophan disclosed in this work is about 2400 ppm or 2.4 g/l.
The lacUV5 promoter was used by Stauffer to eliminate the natural regulation of the trp operon and aroG genes. The lacUV5 promoter is a mutated form of the lac promoter that was selected for relief of catabolite repression. The lac promoter is composed of two regions: the RNA polymerase binding site, which is composed of -10 and -35 regions, and the CAP binding site located at about the -60 region from the transcription start site. The CAP site binds the catabolite activator protein (CAP) that is responsible for activating a transcription of the lac operon when there is no glucose present. When glucose is present, CAP does not bind and transcription is not activated. There is a very low transcription from the lac promoter in the presence of glucose. This phenomenon is known as catabolite repression.
In the -10 region, the lacUV5 promoter is changed from the lac promoter by a mutation from GT to AA. This mutation in the lac promoter was found by selecting for a strain that no longer had catabolite repression of the lac operon. The reduction in catabolite repression appears to result from a better binding of the RNA polymerase to the lacUV5 promoter without the need for CAP.
The tac promoter is a combination of the lacUV5 promoter and the trp promoter using the -10 region from the lacUV5 promoter and the -35 region from the trp promoter which makes a better RNA polymerase binding site. The tac promoter no longer contains the CAP binding site, thus eliminating any catabolite repression. Under certain conditions, the tac promoter is about seven times stronger than the lacUV5 promoter. Both the lacUV5 and tac promoters still contain the lac operator region that binds the lacI gene product, the lac repressor, so both of these promoters still respond to an induction by β-galactosides such as lactose and isopropyl-β-D-thiogalactoside (IPTG).
Further development of the Stauffer two plasmid system and the bacterial host resulted in a one plasmid system that contains a trpEDCBA operon from E. coli including an E. coli feedback resistant AS gene, replacing the S. marcessens AS gene. The trp operon has the attenuator and promoter region removed and is controlled by the tandem lacUV5 promoter described in the Stauffer work. This plasmid, pBE7, also contains the feedback resistant aroG gene coding for the DS enzyme from one of the Stauffer plasmids under the control of the tandem lacUV5 promoters. Also contained on the pBE7 plasmid are the serA and lacI genes from the Stauffer plasmids. The invention uses various plasmids developed from the plasmid pBE7 illustrated in FIG. 1.
The host strain (JB102) was also developed from Stauffer's host strain. The host strain was developed in several steps from the bacterial strain B1238 having the genotype W3110 F' Δ(lacU169, Δ(gal-bio), (trp-lac)) W205 (trp-61-intc-226)!, as described by Benedik et al., Gene, 19:303-311 (1982). This strain B1238 was further developed into strain C534 by the Stauffer Chemical Company as described in WO 87/01130. Strain C534 was further developed by Genencor International by a P1 transduction using a lysate of W3110 and transducing C534 to the genotype trp+, lac-. The resulting strain, PB103, was then transduced with a P1 lysate from the strain JC158 described in Genetics (1963) 48:105-120, which is serA, and a strain was selected that was serA. This strain is JB102 and has the genotype lacU169, tna, serA, anthranilate resistant!.
The Genencor strain (JB102/pBE7) produces about 35 g/l tryptophan in fermenters.
SUMMARY OF THE INVENTION
In keeping with an aspect of the invention, the Escherichia coli K-12 has a recombinant plasmid DNA containing genes encoding the following enzymes for the synthesis of L-tryptophan: aroG encodes 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DS), trpE encodes anthranilate synthase (AS), trpD encodes anthranilate phosphoribosyl transferase (APRT), trpC encodes both N-5'-phosphoribosyl anthranilate isomerase (PRAI) and indole-3-glycerol phosphate synthase (InGPS), and trpBA encodes tryptophan synthase (TS), enabling tryptophan to accumulate in the fermentation medium and recovery of tryptophan from the medium. According to the present invention, L-tryptophan production is enhanced by using a strain of E. coli which has a recombinant DNA plasmid containing the genetic information from E. coli for the synthesis of the following enzymes: DS, AS, PRT, PRAI, InGPS, and TS. These genes are regulated by the tac promoter. The lacI gene product is inducible by isopropyl-β-D-thiogalactoside (IPTG) or lactose or other β-galactoside analogs. The tac promoter is also on the plasmid and is used to regulate the synthesis of the enzyme under the control of the tac promoter. Also contained on the plasmid is the serA gene which helps to maintain the plasmid in a serA deficient host strain and may help overproduce serine which is needed for tryptophan biosynthesis. The E. coli host is defective in tryptophanase. Transformants which are selected have no serine requirement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the plasmid pBE7. Only relevant restriction endonuclease sites are shown.
FIG. 2 shows the plasmid p322KX, which is derived from pBR322.
FIG. 3 shows the constructs p322trp5 and p322trp6.
FIG. 4 shows the construction of p5P11 and p6P29.
FIG. 5 shows the construction of plasmid pBaroGΔB which contains a promoterless aroG and the 5' end of the serA gene from pBE7.
FIG. 6 shows the plasmid pUCS5 which contains the entire serA gene and the 3' end of aroG from pBE7.
FIG. 7 shows the derivation of pR21A1, which contains the aroG gene controlled by tandem lacUV5 promoters and pLRPS14.4 which contains the aroG gene controlled by a single tac promoter. They also both contain the serA gene.
FIG. 8 shows the construction of an EcoRI fragment containing tandem lacUV5 promoters, using mutagenic PCR.
FIG. 9 shows four final tryptophan production plasmids that have tac promoters controlling both the trp operon and the aroG gene.
FIG. 10 shows two other tryptophan production plasmids. Plasmid p5P11A1 has a tac promoter controlling the trp operon and tandem lacUV5 promoters controlling the aroG gene. Plasmid p5R21A1 has tandem lacUV5 promoters controlling both the trp operon and the aroG gene.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides E. coli strains capable of producing L-tryptophan by fermentation. The preparation of the plasmids may be described as follows. Essentially, the trp operon from pBE7 is transferred to a vector derived from pBR322. The tandem lacUV5 promoter of pBE7 is replaced by a promoter related to the commercially available tac promoter. Also included on the plasmid is the aroG gene controlled by the tac promoter and the serA gene and the lacI gene. Unexpectedly, a higher rate of tryptophan production is obtained, even without inducing the tac promoter with the lactose analog IPTG.
1. Preparation of plasmids containing the trp operon from plasmid pBE7.
The plasmid pBE7, shown in FIG. 1, is digested with the commercially available restriction enzymes BamHI and SalI to form BamHI-SalI DNA fragments. One BamHI-SalI fragment from pBE7 contains the trp operon which is controlled by tandem lacUV5 promoters and the lacI gene. This BamHI-SalI fragment is cloned into BamHI-SalI sites of the commercially available plasmid Bluescript KS- to form a plasmid referred to as pBStrp. The plasmid, pBStrp, is then digested with the restriction enzymes SphI and BamHI. The ends of the DNA fragments resulting from the digestion were made blunt using T4 DNA polymerase. KpnI linkers were added to the blunt-ended fragments, which were then digested with the restriction enzyme KpnI and ligated into the KpnI restriction enzyme site of the commercially available plasmid, pUC19, to form a plasmid designated as pUCtrp. The KpnI fragment containing the trp operon and lacI gene is then cloned into a vector called p322KX (which is described below) to form plasmids called p322trp5 and p322trp6, as best seen in FIG. 3, which have the KpnI fragment cloned in opposite orientation. Most cloning steps used E. coli competent DH5α cells purchased commercially for transformation, followed by appropriate selection.
The vector or plasmid p322KX, shown in FIG. 2, was derived from the commercially available plasmid pBR322. Plasmid p322KX (FIG. 2) contains all of pBR322 from the EcoRI site (base pair 4361) of pBR322 to the DraI site (base pair 3230) of pBR322. At the EcoRI site is added a partial pUC19 polylinker containing the restriction sites XbaI, BamHI, XmaI, KpnI and SacI. The EcoRI sites have been destroyed. Thus, p322KX contains no EcoRI sites. This plasmid also has the entire amp gene of pBR322 removed and is tetracycline resistant.
The constructs shown in FIG. 3, p322trp5 and p322trp6, have the trp operon controlled by tandem lacUV5 promoters. In order to facilitate changing promoters, "promoterless constructs" derived from p322trp5 and p322trp6 were made by digesting the plasmids p322trp5 or p322trp6 with the restriction enzyme EcoRI to release the promoter from the rest of the plasmid. The digested plasmid is religated with DNA ligase. Promoterless plasmids were selected by choosing constructs lacking the 200 bp EcoRI lacUV5 promoter fragment. These promoterless constructs are designated p322trp5ΔlacUV5 and p322trp6ΔlacUV5 and best seen in FIG. 4.
An EcoRI cassette containing the tac promoter was made by polymerase chain reaction ("PCR") using standard conditions using p322trp5 plasmid as a template DNA and the following primers: 5' CGAATTCTGTTGACAATTAATCATCGGCTCGTATAATGTG3' (primer 1) SEQ ID NO 4 and 5' CATGATCTCGGCGTATATCG3' (primer 2) SEQ ID NO 5. Primer 1 is homologous to sequences in the lacUV5 promoter, while primer 2 is homologous to sequences in the trp operon. Thus, this will give two PCR products of about 100 base pairs ("bp") or 300 bp depending on which of the tandem lacUV5 promoters primer 1 hybridizes to. The 100 bp PCR product was digested with EcoRI and the 100 bp tac promoter fragment was isolated. This 100 bp tac promoter is similar to the commercially available tac promoter. As seen in FIG. 4, the 100 bp tac promoter fragment is then cloned into the EcoRI restriction enzyme site of the promoterless constructs, p322trp5ΔlacUV5 and p322trp6ΔlacUV5, which were derived from p322trp5 and p322trp6. The two new plasmids, which have the trp operon controlled by the 100 bp tac promoter, were called p5P11 and p6P29 as seen in FIG. 4. These constructs have the trp operon under the control of the tac promoter.
2. Preparation of an XbaI cassette containing the aroG and serA genes.
A cassette was constructed with XbaI restriction enzyme sites on the ends and carrying an aroG gene controlled by the tac promoter and a serA gene controlled by its natural promoter. First, the commercially available plasmid Bluescript SK- was digested with the restriction enzymes SpeI and PstI to form SpeI-PstI fragments. The ends of the fragments were blunted with T4 DNA polymerase and ligated to eliminate the BamHI site in Bluescript, forming the plasmid or vector pBSΔSpP. To this vector, pBSΔSpP, the EcoRI restriction enzyme fragment from pBE7 containing the aroG gene and a partial 5' serA gene is cloned, forming the plasmid pBSΔAroG as seen in FIG. 5.
This plasmid, pBSΔAroG, was cut with the restriction enzyme EcoRV which cuts in the Bluescript SK - polylinker. BamHI DNA linkers were ligated to the resulting EcoRV ends. The ligation was then digested with the restriction enzyme BamHI and re-ligated, which eliminated the EcoRI site in the serA gene. The plasmid pBAroGΔB (FIG. 5) contains the EcoRI-BamHI fragment from pBE7 which contains a promoterless aroG and the 5' end of serA. The EcoRI fragment containing the tac promoter made by PCR as described previously was then added at the only remaining EcoRI site upstream of the aroG gene. This gives an aroG gene controlled by the tac promoter in the plasmid referred to as pLR21P as best seen in FIG. 7.
Plasmid pUCS5 contains the entire serA gene and the 3' end of the aroG gene cloned on an XbaI fragment in pUC19.
The plasmid pUCS5 (FIG. 8) is digested with the restriction enzymes BamHI and SalI to release a DNA fragment containing the 3' end of the serA gene. The BamHI-SalI fragment containing the 3' end of the serA gene is isolated from pUCS5 and added to the plasmid pLR21P digested with BamHI and SalI to recreate the serA gene. As seen in FIG. 7, this construct is designated pLRPS14.4 and contains a feedback resistant aroG gene controlled by the tac promoter as described above and the serA gene.
Similarly, a construct is made using tandem lacUV5 promoters at the EcoRI site instead of the tac promoter. This plasmid is called pR21A1 and contains the feedback resistant aroG gene controlled by tandem lacUV5 promoters and the serA gene on a XbaI fragment, as best seen in FIG. 7.
A tandem lacUV5 promoter on a single EcoRI fragment was constructed using PCR, as seen in FIG. 8. This was done by using p322trp5 plasmid as a template DNA, a mutagenic primer UV5-2 SEQ ID NO 2 having the sequence 5'TGAATCGGAACTCTCTGAACCG3', and a primer UV5-1A SEQ ID NO 1 having the sequence 5'TAGGCGTATCAGGAGGCCCT3'. This will give a PCR product where the EcoRI site between the two lacUV5 promoters has been changed so that the restriction enzyme EcoRI will no longer digest the DNA at this site. The PCR product of this PCR reaction is isolated and used as a "mega" primer along with primer UV5-3C SEQ ID NO 3 having the sequence 5'CATGATCTCGGCGTATATCG3' in a second PCR reaction. This second PCR reaction results in a product that contains two tandem lacUV5 promoters but does not have an internal EcoRI site and can be cloned directly as a single EcoRI fragment. The tandem lacUV5 promoters were used in the construction of PR21A1.
3. Construction of tryptophan production plasmids.
The plasmids illustrated in FIGS. 3 and 4, which contain the tryptophan operon and lacI, are p322trp5, p322trp6, p5P11 or p6P29, are digested with the restriction enzyme XbaI. Either pLRPS14.4 or pR21A1, illustrated in FIG. 7, is also digested with XbaI and the resulting XbaI fragment containing serA and aroG is ligated into these tryptophan-operon-containing plasmids. This produces a series of different plasmids with different orientations of the trp operon lacI cassette and the aroG serA cassette. FIG. 9 shows a set of the 4 possible tryptophan production plasmids with tac promoters controlling both the trp operon and the aroG gene. These plasmids are referred to as p5LRPS3, p6LRPS3, p5LRPS2, and p6LRPS.
A similar set of plasmids with the tac promoter controlling the trp operon and tandem lacUV5 promoters controlling the aroG gene has also been constructed. Plasmid p5P11 A1 is one of this set and is shown in FIG. 10. Plasmids have also been constructed with tandem lacUV5 promoters controlling both the trp operon and the aroG gene. Plasmid p5R21A1 is one of this set and is shown in FIG. 10. These plasmids described in this section were transformed into the host strain JB102 in order to measure tryptophan synthesis.
4. Tryptophan production.
The original tryptophan producer JB102/pBE7 is compared with the various tryptophan plasmids constructed in this work. Initially, each strain is cultured with shaking in 20 mls of seed medium (28 g/l glucose, 24 g/l K 2 HPO 4 , 10 g/l KH 2 PO 4 , 5 g/l (NH 4 ) 2 SO 4 , 1 g/l MgSO 4 .7H 2 O, pH 7.2) at 37° C. for 24 hrs. Then 5 mls of the seed medium is inoculated into 20 mls of fermentation medium (35 g/l glucose, 2 g/l MgSO 4 .7H 2 O, 2 g/l citric acid, 25 g/l (NH 4 ) 2 SO 4 , 7.5 g/l KH 2 PO 4 , 20 g/l CaCO 3 , 1 g/l Na 2 SO 4 , 0.2 g/l MnSO 4 , 0.2 g/l ZnCl 2 , 0.2 g/l CoCl 2 .6H 2 O, 0.03 g/l CuSO 4 .5H 2 O, 3.75 g/l FeSO 4 .7H 2 O, pH 7.2) and shaken at 37° C. for 24 hr. The amount of tryptophan in the fermentation medium is then determined by high pressure liquid chromatography (HPLC).
Some fermentations used the lactose analog, isopropyl-β-D-thiogalactoside (IPTG) to measure its effect. IPTG is an inducer of the lacI gene, which in turn can induce or up-regulate the tac promoter.
The results are shown in Table 1. It is believed from these results that the promoters and genes used in the present invention may already be optimally producing gene products used for tryptophan production and that other factors form the bottleneck for increased tryptophan production. Thus, the addition of IPTG or other lactose analogs to fermentations does not appear necessary for increased tryptophan production.
TABLE 1______________________________________ tryptophan g/l tryptophan g/l (-IPTG) (+IPTG)______________________________________JB102/pBE7 0.61 1.97JB102/p5R21 0.90 2.53JB102/p5P11A1 2.40 2.55JB102/p5LRPS2 3.03 2.98JB102/p5LRPS3 3.28 2.94JB102/p6LRPS2 2.89 2.96JB102/p6LRPS3 2.02 1.88______________________________________
5. Tryptophan production in 5 L fermenters.
Larger scale fermentations were done to measure tryptophan production.
Batch fed fermentations were done in 5 liter vessels. There were three stage fermentations with a shake flask stage to start the bacterial strain's growth; a seed fermenter stage which is inoculated with material from the shake flask fermentation; and a main fermenter stage, inoculated with material from the seed fermenter. These fermentations were run at both high back pressure (15-17 lbs) and low back pressure (1-2 lbs) in the main fermenter stage.
The shake flask stage required that the strains be initially cultured at 37° C. in a shake flask medium (9.5 g/l KH 2 PO 4 , 24.4 g/l K 2 HPO 4 , 15 g/l yeast extract, 5.0 g/l (NH 4 ) 2 SO 4 , 32.6 g/l glucose, 1 g/l MgSO 4 .7H 2 O, 50 mg/l tetracycline). After about 12 hrs of growth at 37° C., an optical density at 660 nanometers (OD660) of 6-10 is reached.
The shake flask culture (0.65 mls) is then added to a volume of 2.1 liters in the seed fermenter stage. The seed fermenter medium contains: 1 g/l yeast extract, 1.2 g/l (NH 4 ) 2 SO 4 , 5.6 g/l KH 2 PO 4 , 1.6 g/l MgSO 4 .7H 2 O, 1.6 g/l Na citrate, 50 g/l glucose, 1.2 mg/l thiamine, 3 mg/l MnSO 4 .H 2 O, 15 mg/1 FeSO 4 .7H 2 O, 0.7 mg/l biotin, pH 7. These fermenter cultures are grown about 12 hrs to an OD660 of approximately 8.
Main fermenters, having 2.1 liters of media, are inoculated with 175 mls of seed culture. The main fermenter medium is: 2.2 g/l (NH 4 )SO 4 , 10.5 g/l KH 2 PO 4 , 2.8 g/l citric acid, 2.8 g/l MgSO 4 .7H 2 O, 28 mg/l Na 2 SO 4 , 6.3 mg/l MnSO 4 .H 2 O, 7.4 mg/l ZnSO 4 .H 2 O, 5.6 mg/l CoCl 2 .6H 2 O, 0.8 mg/l CuSO 4 .5H 2 O, 0.1 g/l FeSO 4 .7H 2 O, 5 g/l glucose, pH 6.5. The main fermenters were run at both high (15-17 lbs) and low (1-2 lbs) back pressures. The high pressure fermenters were maintained at 10% dissolved oxygen (D.O.) and the low pressure fermenters were maintained at 20% D.O. The high pressure runs also used NH 3 gas for maintaining pH 6.5 and the low pressure runs used NH 4 OH for maintaining pH 6.5. Agitation was used to maintain the proper D.O. levels. When the initial glucose is depleted, the fermentation is fed glucose to maintain a glucose concentration of less than 0.1 g/l according to the following typical feed schedule:
______________________________________ Time g/l/hr______________________________________ 0 hr 1.77 1 hr 3.68 2 hr 5.60 3 hr 7.37 4 hr 9.13 5 hr 11.29 6 hr 12.97 7 hr 14.74 8 hr 17.14 20 hr 14.74 26 hr 11.29______________________________________
The fermentations were generally run for 51 hrs at 35° C. Table 2 shows the comparison of the high and low pressure tryptophan production data.
TABLE 2______________________________________ low pressure high pressure g of g of trp/fermenter yield trp/fermenter yield______________________________________JB102/pBE7 133 11.2% 122 9.8%JB102/p5P11A1 152 12% 149 12.5%JB102/p5LRPS2 156 12.8% 165 13.8%______________________________________
The inventive strains are easier to handle in the fermentation than the original strain, JB102/pBE7, and make more tryptophan than JB102/pBE7 in both the high and low back pressure conditions. The data are reported as grams of tryptophan per fermenter because the aqueous NH 3 OH used to control the pH in the low pressure runs increases the total volume in the fermenters by as much as 10% more than the high pressure fermentations where NH 3 gas is used to control pH. The yield of tryptophan from glucose (g tryptophan produced/g glucose consumed) also gives an indication of the relative efficiency of the different strains. The starting strain, JB102/pBE7, has a lower yield at high back pressure than at low back pressure but, unexpectedly, the two inventive strains tested, JB102/p5P11A1 and JB102/p5LRPS2, perform better at high back pressure than at low back pressure. Interestingly, JB102/p5LRPS3 appears to perform less well in fermenters than these two strains. It is believed that increasing the back pressure in a lab scale fermenter will result in a better model of production scale fermentations.
Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention.
__________________________________________________________________________# SEQUENCE LISTING- (1) GENERAL INFORMATION:- (iii) NUMBER OF SEQUENCES: 5- (2) INFORMATION FOR SEQ ID NO:1:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 20 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid- (iii) HYPOTHETICAL: YES- (iv) ANTI-SENSE: NO- (vi) ORIGINAL SOURCE:#coli (A) ORGANISM: Escherichia- (vii) IMMEDIATE SOURCE: (B) CLONE: UV5-1A- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:# 20 CCCT- (2) INFORMATION FOR SEQ ID NO:2:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 22 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid- (iii) HYPOTHETICAL: YES- (iv) ANTI-SENSE: NO- (vi) ORIGINAL SOURCE:#coli (A) ORGANISM: Escherichia- (vii) IMMEDIATE SOURCE: (B) CLONE: UV5-2- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:# 22AAC CG- (2) INFORMATION FOR SEQ ID NO:3:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 20 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid- (iii) HYPOTHETICAL: YES- (iv) ANTI-SENSE: NO- (vi) ORIGINAL SOURCE:#coli (A) ORGANISM: Escherichia- (vii) IMMEDIATE SOURCE: (B) CLONE: UV5-3C- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:# 20 ATCG- (2) INFORMATION FOR SEQ ID NO:4:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 40 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid- (iii) HYPOTHETICAL: YES- (iv) ANTI-SENSE: NO- (vi) ORIGINAL SOURCE:#coli (A) ORGANISM: Escherichia- (vii) IMMEDIATE SOURCE: (B) CLONE: PRIMER 1- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:# 40 TTAA TCATCGGCTC GTATAATGTG- (2) INFORMATION FOR SEQ ID NO:5:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 20 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid- (iii) HYPOTHETICAL: YES- (iv) ANTI-SENSE: NO- (vi) ORIGINAL SOURCE:#coli (A) ORGANISM: Escherichia- (vii) IMMEDIATE SOURCE: (B) CLONE: PRIMER 2- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:# 20 ATCG__________________________________________________________________________ | An improved recombinant DNA plasmid composed of a DNA vector and other DNA fragments containing the tryptophan operon from E. coli, the aroG gene from E. coli and the serA gene from E. coli is shown. The plasmid is transformed into a microorganism belonging to Escherichia coli, and the microorganisms are cultured in a medium and the L-tryptophan accumulated in the culture is recovered. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the alignment of a fixed scroll and an orbiting scroll for a scroll-type fluid displacement apparatus.
2. Description of Related Art
Scroll-type fluid displacement apparatus are known in the art. The structure of a known scroll-type fluid displacement apparatus includes a housing and two scroll members an orbiting scroll and a fixed scroll, each having an end plate and a spiroidal or involute spiral wrap element extending from one side of each end plate. The housing comprises a front housing and a rear housing. The scroll members are maintained at an angular and radial offset, so that both spiral elements interfit to form a plurality of line contacts between their spiral curved surfaces to thereby seal off and define at least one pair of fluid pockets. The relative orbital motion of the two scroll members shifts the line contacts along the spiral curved surfaces and, as a result, changes the volume of the fluid pockets. The volume of the fluid pockets increases or decreases depending on the direction of orbital motion. Thus, this scroll-type apparatus is able to compress, expand, or pump fluids.
In the known scroll-type fluid displacement apparatus, two pin holes are formed in the fixed scroll or in the rear housing and the front housing, respectively, and two single diameter pins are inserted into each pin hole on the fixed scroll or the rear housing, and pin hole in the front housing. These pin holes are used to align the fixed scroll and the orbiting scroll, relative to each other.
In the known scroll-type fluid displacement apparatus, however, the alignment of the fixed scroll or the rear housing and front housing is unconditionally fixed, and the alignment of the fixed scroll and the orbiting scroll is unconditionally fixed. Therefore, the alignment of the fixed scroll and the orbiting scroll may not be finely adjusted to cope with the difference in part sizes within size tolerances. As a result, the efficiency of the compression of fluid may decrease, or the power of compression consumption may increase.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a scroll-type fluid displacement apparatus which may permit fine adjustment to the alignment of a fixed scroll and an orbiting scroll.
In an embodiment, a scroll-type fluid displacement apparatus comprises a front housing, a fixed scroll, an orbiting scroll, and a driving mechanism. The fixed scroll has a first end plate and a spiral element formed on and extending from the first side of the first end plate. The fixed scroll is mounted on the front housing. The orbiting scroll has a second end plate and a spiral element formed on and extending from the first side of the second end plate. Each of the spiral elements interfits at an angular and a radial offset with the other to form a plurality of line contacts defining at least one pair of sealed-off fluid pockets. A driving mechanism includes a drive shaft rotatably supported by the front housing to effect the orbital motion of the orbiting scroll by rotation of the drive shaft and to thereby change the volume of the fluid pockets. Two pin holes are used for the alignment of the fixed scroll and the orbiting scroll. These pin holes are formed in an end surface of the spiral element of the fixed scroll and in an end surface of the front housing. The pin hole formed in the end surface of the spiral element of the fixed scroll and the pin hole formed in (or through) the end surface of the front housing have different diameters.
In another embodiment, a scroll-type fluid displacement apparatus comprises a rear housing and a front housing, a fixed scroll, an orbiting scroll, and a drive mechanism. The front housing closes the opening of the rear housing. The fixed scroll has a first end plate and a spiral element formed on and extending from the first side of the first end plate, and the fixed scroll is attached to the rear housing. The orbiting scroll has a second end plate and a spiral element formed on and extending from the first side of the second end plate. Each of the spiral elements interfits at an angular and a radial offset with the other to form a plurality of line contacts defining at least one pair of sealed-off fluid pockets. The driving mechanism includes a drive shaft, which is rotatably supported by the front housing. The rotation of drive shaft generates the orbital motion of the orbiting scroll, thereby changing the volume of the fluid pockets. Two pin holes are used for the alignment of the fixed scroll and the orbiting scroll. These pin holes are formed in an end surface of the rear housing and in an end surface of the front housing. The pin hole formed in the end surface of the rear housing and the pin hole formed in (or through) the end surface of the front housing have different diameters.
The structure of the scroll-type fluid displacement apparatus described in this invention permits the fine adjustment of the alignment of the fixed scroll and the orbiting scroll.
Other objects, features, and advantages will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily understood with reference to the following drawings, in which:
FIG. 1 is a longitudinal, cross-sectional view of a scroll-type fluid displacement apparatus in accordance with an embodiment of the present invention; and
FIGS. 2 a - 2 e depict the alignment of a smaller diameter pin hole or recess having a bottom and formed in a fixed scroll with a larger diameter penetrating pin hole formed in (or through) the front housing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, scroll-type compressor includes rear casing 4 , front housing 6 , fixed scroll 1 , and orbiting scroll 2 . Fixed scroll 1 is secured to rear casing 4 . Discharge chamber 5 is formed in rear casing 4 behind fixed scroll 1 . Fixed scroll 1 includes disk-shaped first end plate 1 c and first spiral element 1 d . Fixed scroll 1 has discharge port 30 , which is formed through first end plate 1 c at a position near the center of first spiral element 1 d . First spiral element 1 d extends from the first end surface of first end plate 1 c , which is opposite side of discharge chamber 5 . First end plate 1 c of fixed scroll 1 separates suction chamber 20 from discharge chamber 5 in rear casing 4 . Inlet port 18 is formed on front housing 6 and communicates with suction chamber 20 . Outlet port 19 is formed on fixed scroll 1 and communicates with discharge chamber 5 .
Orbiting scroll 2 is located in front housing 6 . Orbiting scroll 2 includes disk-shaped second end plate 2 b and second spiral element 2 c , which extends from the first end surface of second end plate 2 b , and annular boss 2 a , which is formed on and axially projects from the second end surface of second end plate 2 b . First spiral element 1 d of fixed scroll 1 and second spiral element 2 c of orbiting scroll 2 interfit at an angular offset of 180 degrees and a predetermined radial offset. At least a pair of fluid pockets 3 are defined between fixed scroll 1 and orbiting scroll 2 .
Front housing 6 is secured to fixed scroll 1 by a plurality of bolts 17 . Crank chamber 7 is formed in front housing 6 behind orbiting scroll 2 and opposite second spiral element 2 c.
Drive shaft 8 is disposed on a central axis of front housing 6 (i.e., the x-axis) and located in crank chamber 7 . Drive shaft 8 is rotatably supported by front housing 6 through radial bearing 9 . One end of drive shaft 8 projects from front housing 6 . Electromagnetic clutch 10 is rotatably supported by front housing 6 through radial bearing 11 . Crank pin 12 is connected eccentrically to another end of drive shaft 8 . Crank pin 12 is inserted into annular boss 2 a of orbiting scroll 2 and is connected into a disk-shaped eccentric bushing 13 . Eccentric bushing 13 is rotatably disposed in the annular boss 2 a through radial bearing 14 . Thrust plate 15 is disposed between the second end surface of second end plate 2 b of orbiting scroll 2 and an end surface of front housing 6 .
Pin and ring coupling 16 , which prevents orbiting scroll 2 from rotating, is disposed between second surface of second end plate 2 c of orbiting scroll 2 and the end surface of front housing 6 . Two smaller diameter pin holes (or recesses) 1 b , each of which has a bottom, are formed in a flange surface portion of fixed scroll 1 . These smaller diameter pin holes 1 b are positioned in the opposite side of the flange surface portion of fixed scroll 1 , respectively. Two larger diameter pin holes (or recesses) 6 a , which are penetrating holes, are formed through a flange of the end surface of front housing 6 and correspond to smaller diameter pin hole 1 b . These larger diameter pin holes 6 a are positioned through the opposite sides of a flange of the end surface of front housing 6 , respectively.
When a driving force is transferred from an external driving source (e.g., an engine of a vehicle) via electromagnetic clutch 10 , drive shaft 8 is rotated, and orbiting scroll 2 , which is supported by crank pin 12 , is driven in an orbital motion about the x-axis by the rotation of drive shaft 8 . Pin and ring coupling 16 prevents the rotation of orbiting scroll 2 with respect to fixed scroll 1 . When orbiting scroll 2 is driven in an orbital motion, fluid pockets 3 , which are defined between first spiral element 1 d of fixed scroll 1 and second spiral element 2 c of orbiting scroll 2 , move from the outer or prepheral portions of the spiral elements to the central portion of the spiral elements. Refrigerant gas, which enters suction chamber 20 through inlet port 18 , flows into one of fluid pockets 3 . When fluid pockets 3 move from outer portions of the spiral elements to the central portion of the spiral element, the volume of fluid pockets 3 is reduced, and refrigerant gas in fluid pockets 3 is compressed. Compressed refrigerant gas confined within fluid pockets 3 moves to discharge port 30 , displaces a reed valve 31 , and is discharged through discharge port 30 into discharge chamber 5 . Finally, the compressed refrigerant gas passes into an external refrigerant circuit (not shown) through outlet port 19 .
If the alignment of fixed scroll 1 and orbiting scroll 2 in a plane perpendicular to the x-axis is not appropriate, a clearance between a side wall of first spiral element 1 d of fixed scroll 1 and a side wall of second spiral element 2 c of orbiting scroll 2 may be too large or too small. This may cause a decrease of the efficiency of the compression and an increase in the power of compression consumption. The size of the scrolls and other parts of the compressor may vary within a predetermined size tolerance. Therefore, when a scroll compressor is manufactured, the alignment of the fixed scroll 1 and the orbiting scroll 2 in a plane perpendicular to the x-axis is finely adjusted to within a desired range in every scroll compressor. The alignment of fixed scroll 1 and orbiting scroll 2 in a plane perpendicular to the x-axis is defined by an alignment of fixed scroll 1 and front housing 6 in a plane perpendicular to the x-axis.
In this invention of a scroll-type fluid displacement apparatus, each of smaller diameter holes 1 b and larger diameter holes 6 a faces and corresponds to one of the other. When fixed scroll 1 and front housing 6 are assembled, a pin is used to insert into smaller diameter hole 1 b and larger diameter hole 6 a . The pin has a smaller diameter portion, which fits smaller diameter hole 1 b , and a larger diameter portion, which fits larger diameter hole 6 a . Each such pin results in a different alignment of the smaller diameter portion and larger diameter portion. As shown in FIGS. 2 a - 2 e , by preparing a plurality of pins, which have a different alignment of the smaller diameter portion and larger diameter portion, and by selecting an appropriate pin therefrom, the alignment of smaller diameter hole 1 b and larger diameter hole 6 a in a plane perpendicular to the x-axis may be finely adjusted. Therefore, an alignment of fixed scroll 1 and front housing 6 in a plane perpendicular to the x-axis is finely adjusted, and an alignment of fixed scroll 1 and orbiting scroll 2 in a plane perpendicular to the x-axis may be finely adjusted.
FIG. 2 a depicts a situation in which the center of fixed scroll 1 and the center of front housing 6 correspond, and the center of smaller diameter pin hole 1 b and the center of larger diameter pin hole 6 a correspond, and a desired alignment of fixed scroll 1 and orbiting scroll 2 may be achieved. FIGS. 2 b and 2 c depict a situation in which front housing 6 moves in parallel against fixed scroll 1 from the condition depicted in FIG. 2 a because of a tolerance between these parts, and an appropriate alignment of fixed scroll 1 and orbiting scroll 2 may be achieved. FIG. 2 d depicts a situation in which front housing 6 moves in rotation against fixed scroll 1 from the condition depicted in FIG. 2 a because of a tolerance between these parts, and an appropriate alignment of fixed scroll 1 and orbiting scroll 2 may be achieved. FIG. 2 e depicts a situation in which front housing 6 moves in parallel and rotation against fixed scroll 1 from the condition depicted in FIG. 2 a because of a tolerance between these parts, and an appropriate alignment of fixed scroll 1 and orbiting scroll 2 may be achieved.
After the alignment of fixed scroll 1 and front housing 6 is finely adjusted, and the alignment of fixed scroll 1 and orbiting scroll 2 is finely adjusted, a plurality of bolts 17 are inserted into a plurality of penetrating holes formed through fixed scroll 1 . Bolts 17 are threaded into the plurality of threaded holes formed on the end surface of front housing 6 , and front housing 6 is secured to fixed scroll 1 . The plurality of penetrating holes, which are used to be penetrated by a plurality of bolts 17 , have sufficient diameter to absorb a fine adjustment of the alignment of fixed scroll 1 and front housing 6 .
After front housing 6 is secured to fixed scroll 1 , the two pins, which are used to adjust the alignment of fixed scroll 1 and front housing 6 , are no longer required and removed from the side of larger diameter hole 6 a . Therefore, parts, which are no longer required in the scroll-type fluid displacement apparatus, are removed from it. As a result, the number of parts of the scroll-type fluid displacement apparatus may be reduced, and the manufacturing cost of the scroll-type fluid displacement apparatus also may be reduced.
Because smaller diameter pin hole (or recesses) 1 b has a bottom and does not penetrate through fixed scroll 1 , weakening of fixed scroll 1 may be prevented. In the abovedescribed apparatus, front housing 6 is secured to fixed scroll 1 . However, a scroll-type displacement apparatus, which has a structure, such that a front housing is secured to a rear housing and which secures a fixed scroll, is within contemplation of the present invention.
In the above-described apparatus, two smaller diameter pin holes 1 b (or recesses), each of which has a bottom, are formed in fixed scroll 1 and two larger diameter pin holes 6 a , which are penetrating holes, are formed through the end surface of front housing 6 . However, forming two larger diameter pin holes, which are penetrating holes, through fixed scroll 1 and forming two smaller diameter pin holes, each of which has a bottom, in the end surface of front housing 6 are within contemplation of the present invention. In this embodiment, because each smaller diameter pin hole 1 b has a bottom and does not penetrate through front housing 6 , weakening of front housing 6 may be prevented.
As described above, in the embodiments of the present invention of a scroll-type fluid displacement apparatus, the diameter of two pin holes 1 b formed in fixed scroll 1 or in the rear housing and the diameter of two pin holes 6 a formed through front housing 6 are different. Therefore, if a plurality of pins, each of which has a smaller diameter portion and a larger diameter portion and differing alignments between these portions, are prepared, the alignment of fixed scroll 1 or the rear housing and front housing 6 may be finely adjusted, and the alignment of fixed scroll 1 and orbiting scroll 2 may be finely adjusted.
Although the present invention has been described in connection with preferred embodiments, the invention is not limited thereto. It will be understood by those skilled in the art that variations and modifications may be made within the scope and spirit of this invention, as defined by the following claims. | A scroll-type compressor includes a fixed scroll and an orbiting scroll each having an end plate and a spiral element. Each of the spiral elements interfits and form at least one pair of sealed-off fluid pockets. The fixed scroll is connected to a front housing. A driving mechanism includes a drive shaft rotatably supported by the front housing. A first and a second pin hole for aligning of the fixed scroll and the orbiting scroll are formed in an end surface of the spiral element of the fixed scroll and in an end surface of the front housing, respectively, and the first pin hole formed in the fixed scroll and the second pin hole formed in the front housing have different diameters. The configuration of the scroll-type fluid compressor according to this invention may be finely adjusted to align the fixed scroll and the orbiting scroll. | 5 |
This is a divisional application of U.S. patent application Ser. No. 08/796,896 filed Feb. 6, 1997, now U.S. Pat. No. 5,730,266, which is a continuation of U.S. patent application Ser. No. 08/546,395 filed Oct. 20, 1995, now U.S. Pat. No. 5,645,150, which is a continuation of U.S. patent application Ser. No. 08/331,206 filed Oct. 28, 1994, now abandoned, which is a continuation of U.S. patent application Ser. No. 08/035,116 filed Mar. 19, 1993, now U.S. Pat. No. 5,392,888.
BACKGROUND OF THE INVENTION
The present invention relates to a modular clutch construction, particularly to a modular clutch construction wherein the peripheral wall of a clutch cover is marginally fitted at one end onto the cylindrical surface of a flywheel.
A conventional clutch comprises mainly a clutch cover assembly retaining a pressure plate fixed to a flywheel, and a clutch disc assembly located between the flywheel and the pressure plate of the clutch cover assembly.
The clutch cover end extends radially outward in a flange, and the clutch cover assembly thus is mounted to the flywheel by fixing the flange to an end face thereof. Therein, the outside diameter of the flywheel must be larger than that of the clutch disc assembly by the radial width of the flange.
Japanese Utility Model Provisional Number No. 1762 of 1975 discloses a clutch cover attachment structure for minimization of flywheels dimensions, wherein the peripheral wall of the clutch cover is circumferentially assembled onto the cylindrical surface of the flywheel. The outer diameter of the flywheel is on the order of that of the clutch cover, since the flange of a conventional clutch cover is eliminated.
In the foregoing, bolts fix the clutch cover peripheral wall to the flywheel cylindrical surface. Due to the curvature of the flywheel cylindrical surface, the area of contact in seating the fixing bolts is limited. Consequently, retaining friction between the surfaces is insufficient, such that the bolts tend to loosen and portions in seating contact tend to wear. Moreover, shearing forces on the clutch cover act directly upon the bolts, occasionally breaking them off. A solution to this problem is to increase the number of bolts; however, a larger number of bolts adds complexity to the assembly stage.
Furthermore, the clutch cover tends to expand radially outward under centrifugal force generated by rotation of the flywheel. As a result, there is a load on the bolts fastening the clutch cover to the flywheel, which tends to loosen them.
SUMMARY OF THE INVENTION
In a modular clutch construction wherein the peripheral wall of a clutch cover is fixed onto the cylindrical surface of a flywheel, it is an object of the present invention that the clutch cover be secured to the flywheel without increasing steps in the clutch assembly stage.
It is another object of the present invention to prevent clutch cover fastening bolts from loosening and corresponding contact surfaces from wearing, in such a modular clutch construction.
(1) A clutch construction to one aspect of the present invention comprises a flywheel one end face of which is connectable to a corresponding member of an engine for power input; a clutch cover assembly, including a clutch cover circumferentially encompassing and assembled to the cylindrical surface of the flywheel, and a coaxial pressure plate facing the opposite end face of the flywheel; a coaxial clutch disc assembly disposed between the pressure plate and the flywheel; and a ring gear circumferentially fitted onto the peripheral surface of the clutch cover radially outward of its assembly to the flywheel cylindrical surface, such that it is fixed together with both as a module.
In this clutch construction, fitting the ring gear over the flywheel cylindrical surface is accomplished with the clutch cover peripheral wall intervening; consequently, the end margin of the clutch cover is simultaneously clamped between the ring gear and the flywheel cylindrical surface. Thus the clutch cover is secured onto the flywheel cylindrical surface in an assembly stage of reduced steps.
(2) A clutch cover assembly according to another aspect of the present invention comprises a flywheel one end face of which is connectable to a corresponding member of an engine for power input, and the same end face as a circumferentially peripheral bulge protruding axially; a clutch cover assembly, including a clutch cover which encompasses the flywheel and has a flywheel-directed rim portion, bent so as to marginally hold the power-input end face of the flywheel, caulked to the flywheel peripheral bulge, and further provided with retaining elements fixed to the flywheel end face. The clutch cover assembly further includes a coaxial pressure plate facing the opposite end face of the flywheel, and a coaxial clutch disc assembly disposed between the pressure plate and the flywheel.
Wherein the clutch cover is fixed to the flywheel according to the foregoing, the clutch cover peripheral wall wraps the flywheel cylindrical surface, and the clutch cover rim portion is bent over and caulked to the flywheel peripheral bulge, with the clutch cover rim portion retaining elements therein fixed to the flywheel lateral surface. Consequently, steps at the corresponding stage of assembly are reduced because the clutch cover is secured to the flywheel cylindrical surface without the use of fixing bolts.
(3) A clutch device according to a further aspect of the present invention comprises a flywheel, one end face of which is connectable to a corresponding member of an engine for power input, having at fixed radial intervals along its cylindrical surface a plurality of mortise recesses, each of which forms a flat axially extending seat; a clutch cover assembly, including a coaxial pressure plate facing the opposite end face of the flywheel; a coaxial clutch disc assembly disposed between the pressure plate and the flywheel; and fixing means. The clutch cover has tenon portions, formed on an end of the cover directed toward the flywheel, each of which engages with a corresponding flywheel mortise recess. The fixing means secure the clutch cover tenon portions to the flywheel mortise recesses with which they are engaged.
In assembly, the clutch cover tenon portions are engaged with the flywheel mortise recesses in the axial direction, and are then secured to the mortise recesses by the fixing means, which can be bolts. The mortise recesses provide flat seats, corresponding to the tenon portions for full contact therewith, furthermore providing greater surface area for the contact of bolts as a fixing means. Retaining friction therein is thus sufficient to prevent the bolts from loosening, and the contact portions from wearing.
(4) A clutch device according to yet another aspect of the present invention comprises a flywheel, one end face of which is connectable to a corresponding member of an engine for power input; a clutch cover assembly, including a clutch cover and a coaxial pressure plate facing the opposite end face of the flywheel; and a coaxial clutch disc assembly disposed between the pressure plate and the flywheel. A circumferentially peripheral portion of the end face adjacent the pressure plate is an axially projecting rim; and an engine-ward margin along an end of the clutch cover is installed into the inner surface of the flywheel projecting rim, with which it corresponds circumferentially.
With this modular construction, the clutch cover flange for attachment to the flywheel is eliminated. Furthermore, since the clutch cover is restrained against radially outward expansion by the flywheel rim, fasteners such as bolts are therein unnecessary.
The foregoing and other objects and advantages of the present invention will become more apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a clutch construction according to a first embodiment of the present invention;
FIG. 2 is a sectional partial view of the clutch construction;
FIG. 3 is a top partial view of the clutch construction;
FIG. 4 is a modification of the clutch construction, corresponding to FIG. 2;
FIG. 5 is a cross-sectional view of a clutch construction according to a second embodiment of the present invention;
FIG. 6 is a partial end view of the clutch construction;
FIG. 7 is a sectional partial view of the clutch construction;
FIG. 8 is a cross-sectional view of a clutch construction according to a third embodiment of the present invention;
FIG. 9 is a perspective partial view of the clutch construction;
FIG. 10 is a cross-sectional view of a clutch construction according to a fourth embodiment of the present invention;
FIG. 11 is an enlarged partial view of the clutch construction; and
FIG. 12 is a modification of the clutch construction, corresponding to FIG. 11.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, a modular clutch construction is shown to comprise mainly a flywheel 1, a clutch cover assembly 2 and a clutch disc assembly 3. A flexible plate 4 is provided on an engine-ward side, for attaching the clutch to the corresponding engine member, the clutch thus being located between the flexible plate 4 and a transmission front housing 5.
The flywheel 1 is an annular member, having one end face connected to the flexible plate 4, wherein the opposite end face constitutes a friction surface onto which the clutch disc is pressed.
The clutch cover assembly 2 includes a clutch cover 10, a diaphragm spring 11 and an annular pressure plate 12 located within the clutch cover 10.
The clutch cover is formed as a dish having a large-diameter central opening. Peripheral wall 10a of the clutch cover 10 extends axially toward the engine (leftward in FIG. 1) and is fitted onto a cylindrical surface 1a of the flywheel 1. Along the interior surface of the peripheral wall 10a at the end of the clutch cover 10 are, as shown in FIG. 3, a plurality of axially extending, circumferentially spaced slits 10b.
A ring gear 6 is shrink-fitted onto the outer surface of the clutch cover 10 peripheral wall 10a. The ring gear 6 is provided with circumferentially peripheral teeth 6a, with which the pinion of a starter motor is engagable. The clutch cover 10 peripheral wall 10a and the flywheel 1 cylindrical surface 1a are provided with, respectively, holes 10c and 1c, wherein a whirling restraint pin 20 is inserted into each sets of holes 10c and 1c.
The diaphragm spring 11 is a disc concentric with the clutch cover 10. Its radially middle portion is supported by the clutch cover 10 through wire rings 13, and its radially outer portion elastically compels the pressure plate 12 toward the flywheel 1, pressing on a plurality of projections 12b thereof. The radially inner margin of the diaphragm spring 11 is in contact with a release assembly 14, wherein when the release assembly 14 presses the radially inner margin of the diaphragm spring 11 toward the engine (toward the left in the figure), clutch engagement is released.
The clutch disc assembly 3 includes fiction facings 3a along its radially outer margin, which become clamped between the friction surface of the flywheel 1 and a pressing surface 12a of the pressure plate 12.
Next, the assembly procedure of the clutch construction of the foregoing embodiment of the present invention will be explained.
First, the diaphragm spring 11 and the pressure plate 12 are installed into the clutch cover 10, whereby the clutch cover assembly 2 is assembled. The clutch disc assembly 3 is also assembled, and then it and the flywheel 1 are positioned inside the clutch cover assembly 2. At this time, the holes 10c of the clutch cover 10 are each aligned with the corresponding holes 1c of the flywheel 1; and then a pin 20 is inserted into each set of holes 10c/1c, whereby the flywheel 1 is fastened to the clutch cover assembly 2.
At this stage, the ring gear 6 is heated. The clutch cover 10 and the flywheel 1 are cooled, if necessary. The ring-gear 6, having an expanded inside diameter due to the heat, is located around the clutch cover 10, and is circumferentially shrink-fitted onto the exterior of the peripheral wall 10a of the clutch cover 10. Therein, even if the inside diameter of the outer peripheral wall 10a is somewhat greater than the outside diameter of the flywheel 1 (for example, due to manufacturing imperfections), the clutch cover 10 will nevertheless be secured onto the flywheel 1. The reason is that due to the plurality of slits 10b along the interior margin of the clutch cover 10 outer peripheral wall 10a, the outer peripheral wall 10a becomes crimped inward radially and pressed tightly onto the flywheel cylindrical surface 1a by the contraction of the ring gear 6 along its inside diameter.
After the clutch construction is assembled as described above, the flywheel 1 is brought into contact with the flexible plate 4 and the two parts are coupled together by bolts 21. Windows formed in the transmission housing provide access for an assembler to tighten the bolts 21. The flexible plate 4 is previously fixed to an engine crankshaft through bolts 22, before it is coupled with the flywheel 1.
Thus as detailed in the foregoing, fixing the ring gear 6 to the clutch cover 10 simultaneously fixes the construction to the flywheel 1. Additionally, the entire circumferential margin of the clutch cover 10 is fitted onto the flywheel 1, which assemblage is stronger and longer-lasting than is a construction wherein a plurality of bolts are used as fasteners.
Moreover, the elimination of bolts or similar fasteners lowers manufacturing costs and reduces the overall weight of the construction.
Modifications
(a) In the above-described embodiment, the position of the clutch cover 10 relative to the flywheel 1 axially is set by the pins 20 inserted into the clutch cover 10 holes 10c and the flywheel 1 holes 1c. In the structure shown in FIG. 4, the clutch cover 30 peripheral wall 30a is alternatively provided with an abutment 30b where the wall is stepped radially inward. The abutment 30b is machined such that the flywheel 1 friction-surface end face will abut against the abutment 30b, establishing the relative position of the flywheel 1 and the clutch cover 30 axially when the clutch cover 30 is fitted onto the flywheel 1. Thus with this modification, the pins 20 used in the foregoing embodiment are unnecessary.
(b) The inside surface of the clutch cover 10 and/or the outside surface of the flywheel 1 can be knurled in order to increase the frictional force between the clutch cover 10 and the flywheel 1 cylindrical surface.
(c) In the foregoing embodiment, the present invention is incorporated in a push-type clutch; however, the present invention can be applied to a pull-type clutch as well.
Second Embodiment
A modular clutch construction as shown in FIG. 5 mainly comprises a flywheel 31, a clutch cover assembly 32, and a clutch disc assembly 3. A flexible plate 34 is provided on an engine-ward side, for attaching the clutch to the corresponding engine member, the clutch thus being located between the flexible plate 34 and a transmission front housing 5.
The flywheel 31 is an annular member, and its engine-ward end face is formed to have a portion 31a (detailed in FIG. 7) for attaching the flexible plate 34. The end face of the flywheel 31 also has a circumferentially peripheral bulge 31b protruding toward the engine, and pedestals 31c to which the clutch cover 40 is fixed. As enlargedly shown in FIG. 7, axial protrusion of the peripheral bulge 31b increases in extent in the direction of increasing flywheel radius. The pedestals 31c are located at fixed radial intervals, each having a flat face with a central hole. The opposite end face of the flywheel 31 is a friction surface 31d against which the clutch disc assembly 3 presses. A ring gear 36 is circumferentially fixed onto a retaining rim 34a of the flexible plate 34.
The clutch cover assembly 32 is composed by a clutch cover 40, coaxially containing a diaphragm spring 41 and an annular pressure plate 42.
The clutch cover 40 is formed as a dish having a large-diameter central hole. Peripheral wall 40a of the clutch cover 40 extends axially toward the engine, and is provided along its rim with, as shown in FIGS. 6 and 7, caulking portions 40b at fixed radial intervals in alternation with retaining elements 40c.
The caulking portions 40b are bent radially inward so as to clamp the peripheral bulge 31b of the flywheel 31. The retaining elements 40c extend radially inward further than the caulking portions 40b and are bent almost 90° relative to the peripheral wall 40a. Each of the retaining elements 40c is fixed to a corresponding pedestal 31c of the flywheel 31 by a pin 45. Further, the peripheral wall 40a is stepped radially inward to form an abutment 40d on the interior surface. The abutment 40d is machined such that it abuts against the friction surface end face of the flywheel 31, establishing the relative position of the flywheel 31 and the clutch cover 40 axially when the clutch cover 40 is fitted onto the flywheel 31 cylindrical surface.
The diaphragm spring 41 is a disc concentric with the clutch cover 40. Its radially middle portion is supported by the clutch cover 40 through wire rings 43, and its radially outer portion elastically compels the pressure plate 42 toward the flywheel 31, pressing on a plurality of projections 42b thereof. The radially inner margin of the diaphragm spring 41 is in contact with a release assembly 14, wherein when the release assembly 14 presses the radially inner margin of the diaphragm spring 41 toward the engine (toward the left in the figure), the clutch engagement is released.
Next, the assembly procedure of the clutch of the present embodiment will be explained.
First, the diaphragm spring 41 and the pressure plate 12 are installed into the clutch cover 40, whereby the clutch cover assembly 32 is assembled. The clutch disc assembly 3 is also assembled, and then it and the flywheel 31 are positioned inside the clutch cover assembly 32. At this time, the circumferential margin of the end face of the flywheel 31 abuts against the abutment 40d of the clutch cover 40, thereby setting the axial positioning of both parts relative to each other. It should be noted that the corresponding holes in the clutch cover 40 and in the flywheel 31 for the pins 45 are to be brought into alignment.
A caulking device is used for roll-caulking of the rim-ward margin of the peripheral wall 40a of the clutch cover 40, which is initially straight. Each of the caulking portions 40b of the clutch cover 40 are bent so as to clamp the peripheral bulge 31b of the flywheel 31. Each of the retaining elements 40c are bent by approximately 90° so as to be pressed flush against a corresponding pedestal 31c of the flywheel 31. Then, a pin 45 is inserted to each set of corresponding holes in the pedestals 31c and the retaining elements 40c in order to check the clutch cover 40 against whirling relative to the flywheel 31. Thus, according to the foregoing, the flywheel 31 and clutch cover 40 are integrally joined as a modular clutch construction.
After the clutch construction is assembled as described above, the flywheel 1 is brought into contact with the flexible plate 4 and the two parts are coupled together by bolts 21. Windows formed in the transmission housing provide access for an assembler to tighten the bolts 21. The flexible plate 4 is previously fixed to an engine crankshaft through bolts 22, before it is coupled with the flywheel 1.
Since the peripheral wall 40a of the clutch cover 40 is thus caulked to the circumferential margin of the flywheel 31 end face and the two parts are fixed together by the pins 45, the clutch cover 40 is consequently secured to the flywheel 31.
Moreover, the elimination of bolts or similar fasteners reduces the overall weight. In this embodiment, knock pins are unnecessary, because the relative axial positioning of the flywheel 31 and the clutch cover 40 is set by the abutment 40d of the clutch cover 40, thereby reducing manufacturing costs.
Modifications
(a) The inside surface of the clutch cover 10 and/or the outside surface of the flywheel 1 can be knurled in order to increase the frictional force between the clutch cover 10 and the flywheel 1 cylindrical surface.
(b) In the foregoing embodiment, the present invention is incorporated in a push-type clutch; however, the embodiment can be alternatively applied to a pull-type clutch.
Third Embodiment
A modular clutch construction as shown in FIG. 8 mainly comprises a flywheel 51, a clutch cover assembly 52 and a clutch disc assembly 3. A flexible plate 54 is provided on an engine-ward side, for attaching the clutch to the corresponding engine member, the clutch thus being located between the flexible plate 54 and a transmission front housing 5.
The flywheel 51 is an annular member, and its engine-ward end face is connected to the flexible plate 54 and the opposite end face is a friction surface 51a against which the clutch disc assembly 3 presses. As enlargedly shown in FIG. 9, the cylindrical surface 51a of the flywheel 51 is formed with a plurality of mortise recesses 51b at fixed radial intervals. Each of the mortise recesses 51b forms an axially flat seat and has a tapped hole 51c in the center. A ring gear 59 is circumferentially disposed on a retaining rim of the flexible plate 54.
The clutch cover assembly 52 is composed by a clutch cover 60, coaxially containing a diaphragm spring 61 and an annular pressure plate 62.
The clutch cover 60 is formed as a dish and has a large-diameter central hole. The peripheral wall of the clutch cover 60 extends axially engine-ward, and portions thereof are in further extension, forming tenon portions 60a, as shown in FIG. 9. The tenon portions 60a are formed at fixed radial intervals and each has a central hole 60b. The tenon portions 60a are each engaged with the corresponding mortise portions 51b of the flywheel 51 and fixed by bolts 56.
The diaphragm spring 61 is an annular disc concentric with the clutch cover 60. Its radially middle portion is supported by the clutch cover 60 through wire rings 63, and its radially outer portion elastically compels the pressure plate 62 toward the flywheel 51, pressing on a plurality of projecting portions 62b thereof. The radially inner margin of the diaphragm spring 61 is pushed by a release assembly 14, wherein when the release assembly 14 presses the radially inner margin of the diaphragm spring 61 toward the engine (toward the left in the figure), clutch engagement is released.
Next, the assembly procedure of the clutch construction will be explained.
First, the diaphragm spring 61 and the pressure plate 62 are installed into the clutch cover 60, whereby the clutch cover assembly 52 is assembled. The clutch assembly 53 is also assembled. Then, the clutch disc assembly 3 is set into the clutch cover assembly 52, and likewise is the flywheel 51, by engaging the tenon portions 60a of the clutch cover 60 into the mortise recesses 51b thereof. At this time, the rim of the peripheral wall 60, apart from the tenon portions 60a, comes into abutment against the end face of the flywheel 51, thus determining the relative axial positioning of the two parts. The bolts 56 are then screwed into the tapped holes 51c of the mortise recesses 51b, whereby the clutch cover 60 is fixed to the flywheel 51. The tenon portions 60a of the clutch cover 60 are flattened to the axially flat seats of the mortise recess 51b, wherein seating contact between the mortise recesses and the tenon portions 60a, and furthermore between the tenon portions 60a and the bolts 56, is increased, thereby providing sufficient frictional force.
After the clutch construction is assembled as described above, the flywheel 1 is brought into contact with the flexible plate 4 and the two parts are coupled by together bolts 21. Windows formed in the transmission housing provide access for an assembler to tighten the bolts 21. The flexible plate 54 is previously fixed to an engine crankshaft through bolts 22, after the ring gear 59 has been welded to the flexible plate 54.
This embodiment not only provides enough frictional force between the contact portions, but also prevents the bolts 56 from breaking. This is because the fastening bolts 56 are seated on tenon portions 60a of the clutch cover 60 which have been inserted into the circumferentially retaining mortise recesses 51b of the flywheel 51. Furthermore, the number of bolts necessary for fixing the clutch cover 60 can be reduced.
Modification
The present invention is applied to a push-type clutch in the foregoing embodiment; the present invention can be alternatively applied to a pull-type clutch.
Fourth Embodiment
A modular clutch construction as shown in FIG. 10 mainly comprises a flywheel 81, a clutch cover assembly 82, and a clutch disc assembly 3. A flexible plate 84 is provided on the engine-ward side, for attaching the clutch to the corresponding engine member, the clutch thus being located between the flexible plate 84 and a transmission front housing 5.
The flywheel 81 is an annular member, and its engine-ward end face is connected to the flexible plate 84 by bolts 21. The circumferentially peripheral portion of the opposite end face of the flywheel 81 is formed as an axially extending rim 81a. The inner surface of the rim 81a is, as shown enlargedly in FIG. 11, tapped with interior threads 81b for corresponding engagement with the clutch cover 90. The end face of the flywheel 81 radially inward of the rim 81a is a friction surface onto which the clutch disc of the assembly 3 presses.
The clutch cover assembly 82 is composed by a clutch cover 90, coaxially containing a diaphragm spring 91 and an annular pressure plate 92.
The clutch cover 90 is formed as a dish having a large-diameter central hole. The circumferentially peripheral margin 90a of the clutch cover 90 extends axially engine-ward, and is cut with exterior threads 90b for corresponding engagement with the interior threads 81b of the flywheel 81. Provided in the rim 81a of the flywheel 81 and the peripheral margin 90a of the clutch cover 90 are a plurality of radially extending holes, into which whirl-restraint pins 102 are inserted. The whirl-restraint pins each have a circumferential groove into which a set screw 103 is seated, through an axial socket in the crown of the flywheel 81 rim 81a.
Furthermore, a ring gear 86 is shrink-fitted onto the cylindrical surface of the flywheel 81. The ring gear 86 has circumferentially peripheral teeth 86a for engagement with a starter motor pinion.
The diaphragm spring 91 is a disc concentric with the clutch cover 90. Its radially middle portion is supported by the clutch cover 90 through wire rings 93, and its radially outer margin elastically compels the pressure plate 92 toward the flywheel 81, pressing on a plurality of projecting portions 92b thereof. The radially inner margin of the diaphragm spring 91 is pushed by a release assembly 94, wherein when the release assembly 94 presses the radially inner margin toward the engine (toward the left in the figure), clutch engagement is released.
Next, the assembly procedure of the clutch construction will be explained.
First, the diaphragm spring 91 and the pressure plate 92 are installed into the clutch cover 90, whereby the clutch cover assembly 82 is assembled. The clutch disc assembly 3 is also assembled. Then, the clutch disc assembly 3 is set into the clutch cover assembly 82, and thereafter the exterior thread 90b of the clutch cover 90 and the interior threads 81b of the flywheel 81 are matched and the flywheel 81 is screwed in. When the end of the clutch cover 90 bearing the threads 90b comes into contact with the friction surface of the flywheel 81, the clutch cover 90 is backed off until the holes in the clutch cover 90 circumferential margin 90a and those in the rim 81a of the flywheel 81 are in alignment. A pin 102 is inserted into each set of corresponding holes of the rim 81a and the clutch cover 90, and the set screws 103 are accordingly screwed in.
The ring gear 86 is heated and shrink-fitted onto the flywheel 81 cylindrical surface.
After the clutch construction is assembled as described above, the flywheel 1 is brought into contact with the flexible plate 4 and the two parts are coupled together by bolts 21. Windows formed in the transmission housing provide access for an assembler to tighten the bolts 21. The flexible plate 4 is previously fixed to an engine crankshaft through bolts 22, before it is coupled with the flywheel 1.
Because the flywheel 81 and the clutch cover 90 are interlocked by the corresponding threaded portions tapped on the mutual connecting surfaces, bolts or similar fasteners are eliminated by this embodiment. In addition, the clutch cover 90 circumferential margin 90a is restrained by its location inside the rim 81a against radially outward expansion due to centrifugal force.
Modifications
(a) As shown in FIG. 12, the ring gear 86 can be shrink-fitted onto the rim 81a of the flywheel 81. In this case the ring gear 86 is attached to the flywheel 81 after the whirl-restraint pins 104 have been installed and the flywheel 81 is fixed to the clutch cover 90. Thus, the ring gear 86 prevents both the clutch cover 90 and the rim 81a from expanding radially outward under centrifugal force; and it contains the whirl-restraint pins 104 from coming out of the rim 81a, eliminating the set screws therefor.
(b) The present invention is applied to a push-type clutch in the foregoing embodiment; however, the present invention can be alternatively applied to a pull-type clutch.
(c) In the embodiment as described above, the rim 81a is circumferentially continuous on the flywheel 81. Alternatively, it can be formed sectorally around the circumference of the flywheel 81 end face.
Various details of invention may be changed without departing from its spirit nor scope. Furthermore, the foregoing description of the embodiments according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. | Modular clutch construction in which a clutch cover assembly, concentrically containing a pressure plate actuating a clutch disc assembly, is fixed to the flywheel of an engine as a modular unit. The construction improves the modular connection between the clutch cover peripheral wall and the flywheel; in particular through the use of pins to restrain the cover from whirling relative to the flywheel, and by a taking advantage of a method of starter ring-gear installation in which the gear is shrink-fitted over the flywheel with the clutch cover peripheral wall intervening, such that the circumferential end margin of the clutch cover is simultaneously clamped between the ring gear and the flywheel cylindrical surface. The clutch cover is thus secured onto the flywheel in an assembly stage of reduced steps, by comparison with methods employing bolts or other fasteners as the primary connecting means. The modular connection can further be by matching mortise and tenon forms, or by mutually engaging threads, in corresponding portions of the flywheel and the clutch cover. | 5 |
ORIGIN OF THE INVENTION
The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
The invention relates generally to sensors and more specifically concerns a miniature electro-optical flow-direction and airspeed sensor for use on airplanes and remote-controlled models in stability research.
Miniature sensors are needed for rapid and uncomplicated installation on light airplanes engaged in stability research programs. Often, these airplanes are available only for a short time so that preparing and modifying the structure for incorporation of the instrumentation is impossible. Sensors that can be installed by a simple adhesion to a wing, or other surface, often remote from the cabin, are therefore desired. The sensors must be small but at the same time rugged enough to operate reliably in the flight environment. One particularly difficult sensor to miniaturize to this degree has been a flow angle and velocity sensor for measuring the local flow ahead of a wing. A previously developed sensor (Miniature Flow-Direction and Airspeed Sensor for Airplanes and Radio-Controlled Models in Spin Research, NASA TP 1467, May 1979) has been used extensively on a number of government owned airplanes and remote controlled models but because of its large size and complexity, safety considerations require that the sensor be attached to the basic aircraft structure with bolts. This sensor is readily installed on government owned airplanes; but a wider sample of statistical data could be obtained if rented airplanes or airplanes made available by their owners free of charge for short periods of time could be instrumented and tested.
Accordingly, it is a primary object of this invention to provide a miniature flow-direction and airspeed sensor that can be easily and temporarily attached to an aircraft.
Another oject of this invention is to provide a flow-direction and airspeed sensor that eliminates slip rings and the need for electrical leads through moving parts.
A further object of this invention is to provide a flow-direction and airspeed sensor in which the ranges of the phenomena sensed are extremely large.
Still another object of this invention is to provide a simple, inexpensive flow-direction and airspeed sensor for use on aircraft.
Other objects and advantages of this invention will become readily apparent hereinafter in the specification and drawings.
SUMMARY OF THE INVENTION
The invention is a sensor that operates as a free trailing wind vane. The vane, a streamlined body containing a propeller in the nose and a cruciform tail in the rear, self-aligns in an airstream through two independent axes and is attached to the wing surface of an aircraft with a hollow mounting boom. The vane rotates through an angle of ±40 degrees on an axis (yaw axis) through its center of gravity by means of a yoke at the end of a cross-shaft. The cross-shaft fits into a bearing in a stationary pod on the end of the boom, allowing rotation of the vane about its pitch axis.
A sphere having a coded reflective pattern on its surface is mounted on a shaft with the propeller and rotates with the propeller whenever the vane is in an airstream. A light emitting diode (LED) and a photodiode monitors the coded reflective pattern on the sphere to give both the airspeed and the yaw angle. A second LED and photodiode monitors the angular position of the cross-shaft to give the pitch angle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the invention;
FIG. 2 shows the details of how the cross-shaft is attached to the vane in FIG. 1 to provide for the yaw and pitch angles;
FIG. 3 shows a drawing of the reflective pattern on the sphere in FIG. 1;
FIG. 4 is a block diagram of the electrical components used by this invention;
FIG. 5 shows a calibration curve for airspeed;
FIG. 6 shows a calibration curve for yaw angle; and
FIG. 7 shows the natural frequency of the vane as a function of airspeed.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the embodiment of the invention selected for illustration in FIG. 1, the number 11 designates a vane which includes a propeller 12 in the nose and a cruciform tail 13 in the rear. A shaft 14 located inside vane 11 has propeller 12 attached to one of its ends and has a sphere 15 attached to its other end to rotate therewith. A coded reflective pattern 16, which will be described later, is located on the surface of sphere 15.
A hollow boom 17 has means (not shown) on its left end for attaching the boom to a wing of an aircraft. At the other end of boom 17 is a pod 18 for housing a disc 19. Disc 19 is attached to one end of a hollow cross-shaft 20 for rotation therewith. The other end of cross-shaft 20 is attached to vane 11 by means of a yoke (see FIG. 2) such that cross-shaft 20 rotates vane 11 about its pitch axis and vane 11 is free to rotate inside the yoke about its yaw axis 21. The pitch axis and the yaw axis intersect at the center of sphere 15.
A wedge shaped reflective strip 22 is located on the rim of disc 19. An LED 23 emits light onto strip 22 and the reflected light is detected by a photodiode 24. The reflectivity of strip 22 continuously varies around the rim of the disc 19. Consequently, the amplitude of the output of photodiode 24 is indicative of the angular position of cross-shaft 20 and hence is indicative of the pitch angle of vane 11.
An LED 25 located inside pod 18 emits light that passes through a fiber optic bundle 26. A photodiode 27 located inside pod 18 detects the light that flows from a fiber optic bundle 28. Fiber optic bundles 26 and 28 are combined and run through cross-shaft 20 to the other end of the shaft where the combined bundle is terminated. The ends of the fibers in the combined bundle are located such that light emitted from the bundle is directed, through an opening 29, at the center of sphere 15. The light reflected back from the surface of sphere 15 passes through the combined bundle and fiber optic bundle 28 to photodiode 27 which produces a signal proportional to the reflected light. Approximately twice as many fibers are in bundle 28 as in bundle 26.
The yoke for attaching shaft 20 to vane 11 is shown in FIG. 2 and is designated by the numeral 30. Yoke 30 has a shaft 31 which includes conventional means (not shown) for attaching the yoke to shaft 20 for rotation therewith. Vane 11 is mounted inside yoke 30 by means of shafts 32 and 33, and suitable bearings for rotation about the Z axis 21. As can be seen from FIG. 2, vane 11 is free to rotate about the Z axis 21 and will rotate about the pitch axis 34 whenever shafts 20 and 31 rotate.
The reflective surface 16 of sphere 15 is shown in more detail in FIG. 3. Surface 16 is bordered on one side by a meridian 35 and on the other side by a line 36. Line 36 starts from a pole 37 and runs toward the opposite pole 38 along a curved path that increases in longitude in direct proportion to the latitude as measured from pole 37. The target area 16 is truncated near poles 37 and 38 since only the equatorial section is covered by the range of yaw, ±40 degrees measured from the equator 39. The constant of proportionality used to determine line 36 can be selected to be unity, in which case the short side of the target will be 50 degrees in longitude from meridian 35 and the long side will be 130 degrees from the meridian. Therefore, the small side of the target reflects over 50 degrees of longitudinal rotation, the long side reflects over 130 degrees of rotation and intermediate locations reflect for periods proportional to their latitude positions.
The output of photodiode 27 as shown in FIG. 4 is amplified by an amplifier 40 and the resulting waves are shaped or squared by a Schmitt trigger 41 to make them uniform. The output of trigger 41 is integrated by an integrator 42 to produce an analog output that is indicative of the rotation of sphere 15 about the yaw axis 21. In addition, the frequency of the output of trigger 41 is determined by a frequency counter 43 which produces an analog output indicative of the frequency of rotation of shaft 14 or the airspeed.
Whenever vane 11 is placed in a flow field of an aircraft, the rotational speed of propeller 12 is proportional to airspeed and the attitude of vane 11 is indicative of the direction of flow of the flow field. The purpose of this invention is to measure the rotational speed of propeller 12 and the attitude of vane 11 about the yaw and pitch axes.
Light is emitted onto rim 22 by means of LED 23 and the reflected light is detected and converted by photodiode 24 to an output signal proportional to the attitude of vane 11 about the pitch axis (axis through the center of shaft 20).
In addition light from an LED 25 passes through fiber optic bundle 26 and then emitted onto sphere 15. The reflected light passes through by fiber optic bundle 28 and then converted to an electrical signal by photodiode 27. Sphere 15, rotating at an angular rate caused by propeller 12 in the airstream, produces a square-wave output from the photodiode 27 with a frequency proportional to airspeed and with a duty cycle, on-time to period, proportional to yaw angle. The resulting electrical signal is integrated by an integrator 42 to give an output signal proportional to the attitude of vane 11 about the yaw axis 21 or yaw angle. The frequency of the resulting electrical signal is counted by a frequency counter 43 to produce an output signal proportional to the rotational speed of propeller 12 or airspeed.
The accuracy of the sensor was evaluated and found to meet the requirements of the aerodynamicists. The airspeed was calibrated and found repeatable and linear over the flight range to within ±1 m/sec. A free turning propeller responds to volume flow and therefore the output is in proportion to true airspeed, not indicated airspeed, in the absence of significant loading. It can be seen by examining FIG. 5 that after an initial nonlinear increase from the starting point, the data merge quickly to fit a straight line over the remainder of the range. Since the nonlinearity occurs in the region where airplane flight is impossible, this nonlinearity is inconsequential. The dynamic response of the airspeed, a first order system, was measured by analyzing the startup characteristics of the propeller as it is released from a stopped position to final speed while being subjected to a steady airstream. The response is much faster than expected gust or flow angle changes.
The static angular accuracy is determined by analyzing the outputs at known input positions. The angle-of-attack calibration contained some nonlinearity which can be managed in the data analysis. Drift, however is the most troublesome error to manage. Good preflight and postflight calibrations are necessary to eliminate drift effects. The yaw calibration is derived from the rotation of the sphere pattern and is relatively immune from the effects of drift but, as already explained, linearity corrections are introducted in the data analysis program if there are errors in the pattern. The data shown in FIG. 6, for example, contain errors as much as two degrees which must be removed in data reduction. The dynamic responses of each angle measurement are that of a single degree of freedom system of the second order. The natural frequency of the vane bears a linear relationship to the square root of the impact pressure (indicated airspeed) and whatever damping that is present arises from aerodynamical forces produced by the lightweight tail (FIG. 7). It is important to know the natural frequencies likely to be generated in flight. The vane motion can add to the boom motion and produce dangerous divergent oscillations.
The sensor attachment is designed for quick installation and removal from airplanes on flight test programs of a few days duration. The boom fits to a mounting plate which in turn is attached to the wing surface with two sided, neopreme-foam tape. This method of attachment has been shown to be strong enough for the loads of low speed flight.
The advantages of this invention are that it is small in size, it can be rapidly installed on aircraft and it is simple and inexpensive. | A sensor for measuring flow direction and airspeed that is suitable, because of its small size, for rapid instrumentation of research airplanes. A propeller driven sphere rotating at a speed proportional to airspeed presents a reflective target to an electro-optical system such that the duty cycle of the resulting electrical output is proportional to yaw angle and the frequency is proportional to airspeed. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 14/087,980, filed 22 Nov. 2013, which is a continuation and claims the benefit of U.S. patent application Ser. No. 13/663,272, filed 29 Oct. 2012, now issued. U.S. Pat. No. 8,647,377, which is a continuation of U.S. patent application Ser. No. 13/533,658, filed 26 Jun. 2012, now issued U.S. Pat. No. 8,535,367, which is a continuation of U.S. patent application Ser. No. 11/552,913, filed 25 Oct. 2006, now issued U.S. Pat. No. 8,231,665, which is a continuation of U.S. patent application Ser. No. 10/301,061, filed 20 Nov. 2002, now abandoned, which claims the benefit of U.S. Provisional Application No. 60/333,373, filed 26 Nov. 2001, which are all incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to devices and methods for the treatment of diseases in the vasculature, and more specifically, devices and methods for treatment of aneurysms found in blood vessels. Aneurysms can occur in various areas of the cardiovascular system, but are commonly found in the abdominal aorta, thoracic aorta, and cerebral vessels. Aneurysms are unusual ballooning of the vessel due to loss of strength and/or elasticity of the vessel wall. With the constant pulsating pressure exerted on the vessel wall, the diseased or weakened wall can expand out and potentially rupture, which frequently leads to fatality. Prior methods of treating aneurysms have consisted of invasive surgical techniques. The technique involves a major cut down to access the vessel, and the diseased portion of the vessel is replaced by a synthetic tubular graft, Accordingly, this invasive surgical procedure has high mortality and morbidity rates.
[0003] Due to the inherent risks and complexities of the surgical procedures, various attempts have been made to develop minimally invasive methods to treat these aneurysms. For treatment of abdominal and thoracic aortic aneurysms, most of the attempts are catheter-based delivery of an endoluminal synthetic graft with some metallic structural member integrated into the graft, commonly called stent-grafts. One of the primary deficiencies of these systems is durability of these implants. Because catheter-based delivery creates limitations on size and structure of the implant that you can deliver to the target site, very thin synthetic grafts are attached to metallic structures, where constant interaction between the two with every heartbeat can cause wear on the graft. Also, the metallic structures often see significant cyclical loads from the pulsating blood, which can lead to fatigue failure of the metallic structure. The combination of a thin fragile graft with a metallic structure without infinite life capabilities can lead to implant failure and can ultimately lead to a fatality.
[0004] While the above methods have shown some promise with regard to treating aortic aneurysms with minimally invasive techniques, there remains a need for a treatment system which doesn't rely on the less than optimal combination of a thin graft and metallic structural member to provide long-term positive results. The present invention describes various embodiments and methods to address the shortcomings of current minimally invasive devices and to meet clinical needs.
SUMMARY OF THE INVENTION
[0005] In a first aspect, the present invention provides a two part prostheses where one part is an expandable sponge structure and the other part is an expandable tubular mesh structure. The expandable sponge structure is intended to fill the aneurysm cavity to prevent further dilatation of the vessel wall by creating a buffer or barrier between the pressurized pulsating blood flow and the thinning vessel wall. The expandable tubular mesh structure, which is placed across the aneurysm contacting the inner wall of healthy vessel proximal and distal to the aneurysm, serves two purposes. One, it defines the newly formed vessel lumen, even though it does not by itself provide a fluid barrier between the blood flow and the aneurysm. Two, it keeps the expandable sponge structure from protruding out of the aneurysm and into the newly formed vessel lumen. The expandable tubular mesh structure is delivered first across the aneurysm. Then, the expandable sponge structure is delivered via a catheter-based delivery system through a “cell” of the tubular mesh structure and into the aneurysm sac. When the sponge structure is deployed into the aneurysm sac and comes in contact with fluid, it will expand to a size larger than the largest opening or cell of the tubular mesh structure as to prevent the sponge structure from getting out of the aneurysm sac. The filled aneurysm sac will most likely clot off and prevent further dilation of the aneurysm and subsequent rupture. The blood flow should maintain a natural lumen Where the luminal diameter is approximately defined by the diameter of the tubular mesh structure. The advantage of this system is that the sponge filler material acts like a graft but has unparalleled durability. The metallic structure can be optimized for durability as well because the size constraint is somewhat relieved due to the absence of an integrated graft material, which takes up a significant amount of space in a catheter.
[0006] In addition, the expandable sponge structure can be used to repair existing endoluminal stent-grafts which have developed leaks. There are thousands of endoluminal stent-grafts implanted into humans to treat abdominal aortic aneurysms. That number is growing daily. The endoluminal stent-grafts are intended to exclude the aneurysm from blood flow and blood pressure by placing a minimally porous graft supported fully or partially by metallic structural members, typically called stents. The acute success rate of these devices is very high, but there are a significant number of these which develop leaks, or blood flow/pressure re-entering the aneurysm sac, some time after the procedure. If the source of the leak can be accessed by the delivery system, the expandable sponge structure can be deployed through that access point.
[0007] In another aspect, the present invention provides an inflatable tubular balloon graft. It is a tubular graft, straight or bifurcated, where its wall is not a solid structure but a hollow chamber. The chamber can be filled with a variety of materials which can dictate the mechanical properties of the prostheses. The unfilled tubular balloon graft can be folded and loaded into a catheter-based delivery system, and once in position the tubular balloon graft can be “inflated” with the filler material. The material would be filled in a fluid form and may stay a fluid form or can be solidified by various means such as UV light, heat, and time. The advantage of this system is that a metallic structure is not needed to provide structure to the graft. It is instead replaced by the injectable fluid within the chamber of the tubular balloon graft. Customization of the mechanical properties of the graft is easily accomplished by using balloon fillers of varying properties.
[0008] The tubular balloon graft can be completely non-porous, completely porous with same degree of porosity throughout the graft, completely porous with varying porosity within the graft, or partially non-porous and partially porous. Significant porosity on the very outer layer would allow for delivery of an aneurysm sac filling substance or a drug. Porosity on the ends of the graft will help promote cellular in-growth. Porosity on the ends can also he used to deliver an adhesive so that the graft can be securely attached to the vessel wall.
[0009] Another embodiment of the tubular balloon graft includes a tubular balloon graft with a bulging outer layer. This will allow the outer surface of the tubular balloon graft to fill some or all of the aneurysm. This will provide a primary or secondary barrier for the aneurysm wall from the pulsating blood flow and will provide a means to prevent migration of the graft due to the enlarged area within the graft. An alternate method of construction would be to attach a bulging outer skin to a standard tubular thin-walled graft and provide a port for injection of the filler substance. Alternatively, instead of a bulging outer skin, a very compliant outer skin can he used so that the volume of material is minimized. The compliant outer skin would be able to expand at very low inflation pressures that would be non-destructive to the aneurysm wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A illustrates the two-part prosthesis.
[0011] FIG. 1B illustrates a bifurcated version of the expandable tubular mesh structure and the expandable sponge structure.
[0012] FIG. 1C illustrates an expandable tubular mesh structure placed across an aneurysm and the expandable sponge structure filling up the aneurysm.
[0013] FIGS. 2A-2C illustrate the various cross-sections of the expandable sponge structure.
[0014] FIG. 3A illustrates a long continuous sponge structure.
[0015] FIG. 3B illustrates multiple short sponge structures.
[0016] FIG. 4 illustrates the catheter-based delivery system.
[0017] FIG. 5 illustrates a curved delivery catheter.
[0018] FIG. 6 illustrates a method of ensuring that the delivery catheter's tip stays inside the aneurysm sac.
[0019] FIG. 7A illustrates an expandable basket-like structure.
[0020] FIG. 7B illustrates an expandable braid-like structure.
[0021] FIG. 8 and 9 illustrate expandable tubular mesh structures.
[0022] FIG. 10 illustrates a delivery catheter tracked over a guidewire and placed in a stent-graft which developed a leak.
[0023] FIG. 11 illustrates the sponge delivered through the delivery catheter.
[0024] FIGS. 12-15 illustrate tubular balloon grafts.
[0025] FIGS. 16 and 17 illustrate tubular balloon grafts being expanded.
[0026] FIG. 18 illustrates a tubular balloon graft.
[0027] FIGS. 19 , 20 A and 20 B illustrate a vascular graft with an integrated tubular balloon.
[0028] FIGS. 21A-21E illustrate a method of delivering a graft with an external balloon.
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIG. 1A shows the two-part prosthesis comprising of an expandable sponge structure 1 and an expandable tubular mesh structure 2 placed in an abdominal aortic aneurysm 3 located in the infra-renal aorta not involving the iliac arteries. FIG. 1B shows a bifurcated version of the expandable tubular mesh structure 2 and the expandable sponge structure 1 in an abdominal aortic aneurysm located in the infra-renal aorta and involving both iliac arteries. FIG. 1C shows an expandable tubular mesh structure 2 placed across an aneurysm commonly found in cerebral arteries and the expandable sponge structure 1 filling up the aneurysm. The expandable sponge structure I is placed through the expandable tubular mesh structure 2 into the aneurysm, filling up the aneurysmal sac which provides a barrier between the thin fragile wall of the aneurysm and the pressurized pulsating blood. The tubular mesh structure 2 keeps the expanded sponge 1 within the confines of the aneurysm and away from the flow path.
[0030] The expandable sponge structure 1 is preferably made of common medical grade polymers or natural substances like collagen which can be manufactured into a sponge structure. The sponge structure can be processed in such a way so that it can be compressed to a dry condition size substantially smaller than the wet condition size, exhibiting huge expansion ratio. The expanded sponge structure can take various forms. FIGS. 2A-2C show the various expanded cross-sections that the expandable sponge structure 1 can be. FIG. 2A shows a circular cross section, FIG. 2B shows a square cross section, and FIG. 2C show a triangular cross section. Any cross section can be used. The most important requirement is that it cannot escape from the aneurysm sac through a cell of the expandable tubular mesh structure 2 . The length of the expandable sponge structure 1 can vary as well. FIG. 3A shows a long continuous structure 1 . And FIG. 3B shows multiple short structures 1 .
[0031] One method of delivering the sponge filler 1 into the aneurysm sac is shown by the catheter-based delivery system in FIG. 4 . The catheter 4 can hold the compressed sponge 1 within its lumen, and when pushed out with the plunger 5 into the blood filled aneurysm sac, the sponge will expand out to a substantially larger size. The expanded size of the sponge filler is preferably larger than the largest opening of the tubular mesh is structure as to prevent the sponge from escaping the aneurysm sac. FIG. 5 shows an example of a curved delivery catheter 4 , where the tip is placed through a cell of the tubular mesh structure 2 and the expandable sponge structure 1 is being deployed into the aneurysm sac. It is important that the tip of the delivery catheter is through a cell of the tubular mesh structure into the aneurysm because the expandable sponge will expand very quickly after being exposed to the blood and being unconstrained by a catheter. FIG. 6 shows a method of ensuring that the delivery catheter's 4 tip stays inside the aneurysm sac by having a balloon 6 on the tip of it, and when inflated after the tip is within the aneurysm sac it will prevent the catheter tip from backing out of the aneurysm sac. FIG. 7A shows an expandable basket-like structure 7 and FIG. 7B shows an expandable braid-like structure 8 which are alternatives to having a balloon 6 on the tip of the catheter 4 .
[0032] The expandable tubular mesh structure 2 can be made of a metal or of a polymer. The versions made of a metal can be self-expanding from a smaller compressed state or balloon expandable from a smaller compressed or as-cut state. The self-expanding version may be made of metals which exhibit large amounts of elasticity (i.e. nickel-titanium, spring steel, MP-35N and elgiloy) such that when they are compressed down from their expanded state to the compressed state to load into a delivery catheter, they will substantially return to their expanded condition when released from the catheter. Alternatively, shape memory metals like nickel-titanium can be used to provide large expansion ratios. The balloon expandable version may be made of metals which exhibit large permanent deformations without significantly compromising the mechanical performance. The following are some common medical grade metals which are well suited for this purpose: stainless steel, titanium, tantulum, and martensitic nickel titanium. In either the self-expanding or the balloon expandable case, the intent is to deliver the expandable tubular mesh 2 to the target site in a smaller or compressed condition via a catheter-based delivery system so that the target site can be accessed through a remote vascular access point which is conducive to a percutaneous or minimally invasive approach.
[0033] The expandable tubular mesh structure 2 shown in FIGS. 1A , 1 B, 1 C, 5 , and 6 represent a generic mesh structure. FIG. 8 shows an expandable tubular mesh structure where long continuous struts 9 are connected to anchoring end members 10 . This allows the structure to be very low in profile in the compressed state, and the durability of this type of structure can be optimized because no radial element exists in the longitudinal struts 9 . FIG. 9 show an alternate expandable tubular mesh structure preferably made from a polymer such as PTFE, Polyester, Polyurethane, and the like. The structure has relatively large holes 11 to give access to the expandable sponge delivery catheter. The ends incorporate an anchoring member 12 , either self-expanding or balloon expandable.
[0034] FIG. 10 shows a delivery catheter 4 which has been tracked over a guidewire 14 , which has been placed into the aneurysm sac through an opening 15 of an existing endoluminal stent-graft 13 which developed a leak. The balloon 6 on the delivery catheter 4 was inflated after the delivery catheter 4 was positioned within the aneurysm sac. FIG. 11 shows the guidewire 14 removed, and the expandable sponge structure 1 being delivered through the delivery catheter 4 .
[0035] FIG. 12 shows a section view of a tubular balloon graft 19 positioned across an infra-renal aortic aneurysm blocking off the flow to the aneurysm sac. The tubular balloon graft's 19 wall is made of an inner wall 16 , an outer wall 17 and a chamber 18 between them. The chamber 18 can be filled with various materials to dictate the mechanical properties of the prosthesis. FIG. 13 shows a bifurcated tubular balloon graft 20 positioned across an infra-renal aortic aneurysm with bi-lateral iliac involvement.
[0036] The tubular balloon implant can be made of the various biocompatible materials used to make balloon catheters. Those materials include P.E.T. (Polyester), nylon, urethane, and silicone. It can also be made of other implant grade materials such as ePTFE. One method of making such a device is to start with two thin walled tubes of differing diameters. The difference between the diameters of the tubes will dictate the volume of the balloon chamber. The ends of the tubes can be sealed together with adhesive or by heat to form the balloon chamber. A communication port will be necessary to be able to fill the port with the injected material.
[0037] The injected material can be an epoxy, a UV-curable epoxy, silicone, urethane or other type of biocompatible materials such as albumin, collagen, and gelatin glue which is injected into the balloon, and then cured in situ. Or, the injected material doesn't necessarily have to be cured. The as-delivered state may provide the appropriate mechanical properties for the application. Therefore, substances like sterile saline, biocompatible oils, or biocompatible adhesives can be left in the tubular balloon in the as-delivered state.
[0038] The tubular balloon graft can be non-porous to very porous. FIG. 14 shows a version where the tubular balloon graft has a porous outer wail 24 . The chamber 21 of the tubular balloon graft can be used to deliver an aneurysm sac filling substance such as UV curable adhesive 22 . The holes 23 which dictate the porosity of the tubular balloon graft can be created with laser drilling, etching, and other methods. The porosity can be varied in select areas of the graft. FIG. 15 shows a tubular balloon graft with only the ends of the graft have porosity to either promote cellular in-growth or to inject an adhesive which allows secure attachment of the graft ends to the vessel wall.
[0039] FIG. 16 shows a tubular balloon graft 19 which is being expanded from a folded condition (not shown) by a balloon catheter 25 . Once expanded, the chamber 18 of the tubular balloon graft 19 can be filled with the desired substance through the chamber access port 26 . FIG. 17 shows a tubular balloon graft 19 being expanded by an inflation process or filling the chamber 18 of the tubular balloon graft 19 through the chamber access port 26 .
[0040] FIG. 18 shows a version of the tubular balloon graft with an outer wall 17 which is substantially bulged out so that it fills some or all of the aneurysm sac. FIG. 19 shows a vascular graft 27 which has an integrated balloon 28 attached to the outside surface of the graft. The balloon can be pre-bulged and folded down for delivery, or it can be a very compliant material like silicone, urethane, or latex so that it has no folds whether compressed or expanded. FIG. 20A shows the same type of implant, a graft 27 with an external balloon 28 , used in a cerebral vessel aneurysm 29 . FIG. 20B show the same implant as 20 A, except that the implant balloon does not fully fill the aneurysm, which can be acceptable because the graft 27 excludes the aneurysm from the blood flow, and the primary purpose of the balloon 28 is to prevent migration of the graft 27 .
[0041] The graft 27 can be made of commonly used implant polymers such as PTFE, Polyester, Polyurethane, etc. The balloon 28 surrounding the graft can be made of the same commonly used vascular implant materials as well. The graft and balloon materials can be different, but it is commonly known that using the same material for both would facilitate processing/manufacturing. The theory is that the balloon 28 would preferentially only deploy into the aneurysm sac where the resistance to expansion is minimal as compared to the vessel wall. The graft 27 would provide the primary barrier between the pressurized blood and the thin wall of the aneurysm. Secondarily, the balloon itself provides a buffer from the pressurized blood. The balloon's 28 primary function, however, is to hold the graft 27 in place. Since the expanded section of the implant is “locked” into the aneurysm, the graft 27 should not migrate. Also, the balloon 28 , in the filled state, will provide hoop strength to the graft 27 .
[0042] FIGS. 21A-21E demonstrate one method of delivering a graft with an external balloon to the target site. FIG. 21A shows the implant loaded onto a balloon delivery catheter 30 with an outer sheath 32 and positioned over a guide wire 31 at the aneurysm target site. FIG. 21B shows that once in position, the outer sheath 32 is withdrawn. FIG. 21C shows the balloon delivery catheter 33 being inflated, pushing the implant 34 against the healthy vessel walls on both sides of the aneurysm. FIG. 21D shows that the balloon delivery catheter 30 may also have an implant balloon inflation port 35 which can now be used to fill up the implant balloon 28 with a biocompatible substance. The substance can be sterile saline, contrast agent, hydrogel, and UV cure adhesive to name a few. Most likely, low inflation pressures would be used to fill the implant balloon 28 . FIG. 21E shows that once the implant balloon 28 is filled, the implant balloon inflation port 35 can be detached and the delivery catheter 30 removed. | The present invention relates to devices and methods for the treatment of diseases in the vasculature, and more specifically, devices and methods for treatment of aneurysms found in blood vessels. In a first embodiment of the present invention, a two part prostheses, where one part is an expandable sponge structure and the other part is an expandable tubular mesh structure, is provided. In the first embodiment, the expandable sponge structure is intended to fill the aneurysm cavity to prevent further dilatation of the vessel wall by creating a buffer or barrier between the pressurized pulsating blood flow and the thinning vessel wall. In the first embodiment, the expandable tubular mesh structure is placed across the aneurysm, contacting the inner wall of healthy vessel proximal and distal to the aneurysm. | 0 |
This application is a divisional of application Ser. No. 08/679,682, filed Jul. 11, 1996, now U.S. Pat. No. 5,775,052.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a method of attaching roofing material in sheet form to horizontal roof decks (substrates) and vertically extending roof structures or walls (i.e., parapet) requiring less manpower and time-consumption, while achieving the desired result of securely attaching roofing material that is water-tight and wind-resistant.
Known methods of installing roofing material are time-consuming and require the use of two or more installers. In known methods, tabs are attached to the inside surface of the roofing material. Each tab is installed to the roofing material via a fastener, or anchor (e.g., a screw, nail, or any other equivalent fastening means). A fastener is driven through the tab and into the roofing substrate thereby securely attaching the material to the roof. The first fastener is installed on the horizontal roof substrate just before the material makes a right angle turn to climb the parapet. One or more installers are required to hold the roofing material up, or away, from the roof substrate and/or the parapet while another worker is required to pull the tab taut against the roof substrate. In this position, an additional worker can then fasten the tab to the roof substrate. As discussed, this process requires at least two to three workers. Additionally, this method requires a significant amount of time as the process is inherently cumbersome. Accordingly, a new and reliable process of installing roofing material is needed which can be performed by one installer, thereby significantly decreasing the cost and time of installing roofing material.
The method of the present invention for installing roofing material involves the use of a roof membrane which is comprised of a sheet of roofing material which may have tabs affixed to its outer surface. The ends of the roofing material are first fastened to the wall or roof substrate to be covered. The ends of the roofing material are fastened by tabs which are affixed to the underside of the roofing material. The portions of the roofing material between the fastened ends are fastened to the wall or roof substrate by installing fasteners directly through the roofing material into the wall or roof substrate to be covered. Tabs are affixed to the outer surface of the roofing material which can be folded back so that fasteners can be installed directly through the roofing material. Once fastened, the tabs can be folded back into place to cover the fasteners. The tabs may then be welded, or otherwise sealed, shut so that the roofing material is protected from rain, water, and other elements. The present method of installing roofing material saves significant time since the tabs affixed to the outside surface allow the roofing material to be fastened by one worker (there is no need for another worker to lift and hold the roofing material while fastening). Additionally, the roof membrane of the present invention can be pulled taut one sheet at a time, whereas the known methods require each tab to be pulled taut for each intervening tab.
In addition to the features mentioned above, objects and advantages of the present invention will be readily apparent upon a reading of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
Novel features and advantages of the present invention, in addition to those mentioned above, will become apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:
FIG. 1 is a cross-sectional view of a parapet showing the installation of roofing material on a parapet and a portion of the horizontal roof deck substrate using a known method;
FIG. 2 is a cross-sectional view of a parapet showing the installation of roofing material on a parapet and a portion of the horizontal roof deck substrate according to the method of this invention;
FIG. 3 is a cross-sectional view of roof layer showing the installation of roofing material on a horizontal roof deck substrate using a method known in the art;
FIG. 4 is a cross-sectional view of a roof layer showing the installation of roofing material on a horizontal roof deck substrate according to the method of this invention;
FIG. 5 is a cross-sectional view of a plate and fastener in use in fastening the roofing material to the roof substrate; and
FIG. 6 is a cross-sectional view of a fastener in use in fastening the roofing material to a parapet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred system herein described is not intended to be exhaustive or to limit the invention to the precise forms disclosed. They are chosen and described to explain the principles of the invention, and the application of the method to practical uses, so that others skilled in the art may practice the invention.
FIG. 1 illustrates the installation of roofing material on a wall (or parapet) using a method known in the art whereby the first fastener is installed at 10 and subsequent fasteners are installed in sequence at predetermined intervals 20, 30, 40 and 50. All fasteners are inserted through tabs which are attached to the underside surface of the roofing material closest to the roof or wall being covered. (Reference number 12 refers to a tab on the underside surface of a known roofing material.) These previously known methods of roofing require at least two workers to install the roofing material. For proper installation, since all the tabs of the known roofing materials are located on the underside of the roofing material, at least one worker is needed to pull the roofing material taut against the roof substrate and/or the wall to be covered, while another worker must position himself so as to be able to insert a fastener through the tab and drive the fastener into the roof substrate or wall. (An additional worker is often needed to hold the roofing material up or away from the worker pulling the tab.)
The method of roofing of the present invention may be accomplished with a prefabricated sheet of roof membrane 92 of the present invention. A pre-fabricated sheet of roof membrane 92 is comprised of: a sheet of roofing material 62; tabs 74, 76 affixed to the underside surface 78 of the roofing material 62; and tabs 84 affixed to the exterior surface 72 of the roofing material 62, where the tabs 74, 76, 84 are positioned at a predetermined distance in relation to each other. Additionally, as illustrated in FIGS. 2 and 4, the tabs 84 affixed to the exterior surface 72 of the roofing material 62 are placed along a length of the roofing material 62 and between the tabs 74, 76 affixed to the underside surface 78 of the sheet of roofing material 62.
The length and width of the pre-fabricated sheet of roof membrane 92 will vary based on the width or height of the roofing surface. The sheet of roof membrane 92 can also be standardized to a no material waste standard size that a contractor can fit in the center of a roof, while making the appropriate fitting measurements at the perimeters of the roof. This process will standardize the sheets and cut material costs. Various known materials can be used to manufacture the sheet of roof membrane 92 of the present invention.
FIG. 2 illustrates the installation of a roof membrane 92 onto a parapet (or wall 66) using the method of this invention. The first fastener is installed at 60 and the second at 70 using via the tabs 74, 76 attached to the underside of the material 62. A predetermined number of intervening fasteners are installed directly through the roofing material 62 into the wall 66 at 80, 90, 100 and 110. (The number of intervening fasteners required may vary depending on the particular installer, the thickness and length of the roofing material 62, and the type of roofing material 62 and fastener used.) Once the intervening fasteners are driven into the wall 66, tabs 84, or plates, affixed to the exterior surface 72 of the roofing material 62, are folded down on the fasteners. The perimeters of the tabs 84 are then field-welded, or otherwise sealed, closed to prevent moisture from penetrating the hole made by the fastener.
Referring to FIG. 2 in more detail, the roofing method of the present invention is accomplished by: first fastening the roof membrane 92 of the present invention to the top 64 of a wall 66; then fastening the roofing material 62 at a location 68 near the bottom of the wall 66; and then fastening the roofing material 62 to the intervening portion of the wall 66 by fastening means, where the fastening means securing the intervening portion of the roofing material 62 are installed directly through the exterior surface 72 of the roofing material 62 and into the wall 66. The intervening portion of the wall 66 merely refers to the portion of the wall 66 between the top 64 and bottom areas 68 of the wall 66. The location 68 near the bottom of the wall where the roofing material 62 is fastened is preferably a portion of the roof substrate 82 just beyond the point where the wall 66 and the roof substrate 82 meet (e.g., tab 76 in FIG. 2).
The roofing material 62 is fastened to the top 64 of the wall 66 and to a location 68 near the bottom of the wall 66 by installing a fastening means through the tabs 74, 76 affixed to the underside surface 78 of the roofing material 62.
The present method of roofing can be performed by one worker. For example, once the tab 74 is secured at the top 64 of the wall 66, the worker may allow the roofing material 62 to hang down to the bottom of the wall 66. When a screw, or fastener, is installed at the location 68 near the bottom of the wall 66, the roofing material 62 will draw taut. Since the fastening means securing the intervening portion of the roofing material 62 is installed directly through the exterior surface 72 of the roofing material 62, an additional worker is not required to lift and hold, or pull, the roofing material 62 while the fastening means is installed.
As illustrated in FIGS. 2 and 4, the roofing material 62 of the present invention is comprised of tabs affixed to the exterior surface 72 of the roofing material 62. The tabs 84 may be folded back so that a fastener can be installed directly through the roofing material 62. (The arrow 101 in FIG. 2 shows the direction in which the tab 84 at location 100 may be folded back.) The roofing material 62 may be fastened to the intervening portion of the wall 66 by first folding back the tabs 84 before installing the fastening means directly through the exterior 72 surface of the roofing material 62 and into the wall 66. Subsequently, the tabs 84 may be folded back into position to cover the fastening means. The tabs 84 may be welded, or otherwise sealed (e.g. by glue), shut for purposes of waterproofing the roofing material 62.
Once the wall 66 (or parapet) is covered with the roofing material 62, the roof substrate 82 may also be similarly covered. FIG. 3 illustrates the known method of installing roofing material on a horizontal roof substrate. The known roofing method is accomplished by fastening the roofing material at locations 120, 122, 124, 126, 128, and 132 whereby all fasteners are inserted through tabs located on the interior surface of the roofing material. The fasteners are then driven into the roof substrate 82. Again, as discussed above, these known roofing methods require at least two to three workers to complete; one for holding back the roofing material, another for pulling the tab taut, and an additional worker for fastening the roofing material to the substrate.
FIG. 4 illustrates another embodiment of the present invention showing the installation of a roof membrane 92 on a roof substrate 82 according to the method of this invention. Normally, the roof substrate 82 will be in the horizontal plane. If the roof substrate 82 is connected to a wall 66 (or parapet) which has been covered with the roof membrane 92, as discussed above, the fastener at 70 will already have been installed (see FIG. 5). In this instance, the roofing material 62 would then be fastened to the roof substrate 82 at location 134 (or at the far end of the roof substrate 82 in relation to the wall 66). The roofing material 62 would then be fastened to the intervening portion of the roof substrate 82 as will be described below.
The roof substrate 82 can also be covered with a roof membrane 92 by the method of the present invention, independently of the covering of an attached wall 66, if any. The roofing material 62 is first fastened to the roof substrate 82 at one end (either location 70 or 134) of the roofing material 62. The roofing material 62 is then fastened to the roof substrate 82 at the second end (either 70 or 134 whichever has not yet been fastened) of the roofing material 62. Once the ends 70, 134 have been fastened, the roofing material 62 is fastened to the intervening portion of the roof substrate 82 by fastening means installed directly through the roofing material 62 and into the roof substrate 82. (Again, the intervening portion of the roof substrate 82 is merely the portion of the roof substrate 82 between the end locations 70, 134.)
Again, as illustrated in FIGS. 2 and 4, the roof membrane 92 is comprised of roofing material 62 which is further comprised of tabs 84 placed on its exterior surface 72. The tabs 84 may be folded back to expose the exterior surface 72 of the roofing material 62. The roofing material 62 may be fastened to the intervening portion of the roof substrate 82 by first folding back the tabs 84 before installing the fastening means directly through the roofing material 62 and into the roof substrate 82. Subsequently, the tabs 84 can then be folded back into position to cover the fastening means. The tabs 84 may then be field-welded, or otherwise sealed, shut for purposes of waterproofing the roofing material 62. All remaining fasteners at locations 136, 138, and 140 may be installed according to this method. Accordingly, the method of the present invention saves considerable time and money from the known roofing techniques by enabling one worker to pull the roofing material 62 taut one-time per sheet as opposed to one tab at a time.
FIG. 4 illustrates a roof layer, or deck sheet 94 (i.e., a roof substrate 82 which has been covered with a prefabricated sheet of roof membrane 92) of the present invention. The deck sheet 94, is comprised of a roof substrate 82 and a sheet of roof membrane 92 covering the roof substrate 82. The roof substrate 82 may be comprised of a deck layer 96 and an insulation layer 98.
FIGS. 5 and 6 illustrate cross-sectional views of different types of fasteners, in use, that may be used to fasten the roofing material 62 to a roof substrate 82 or wall 66.
Having shown and described a preferred embodiment of the invention, those skilled in the art will realize that many variations and modifications may be made to affect the described invention and still be within the scope of the claimed invention. Thus, many of the elements indicated above may be altered or replaced by different elements which will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims. | A method and apparatus for the installation of roofing material. The method of installing roofing material of the present invention requires less manpower and consumes less time. Tabs are affixed to the outside of the roofing material which fold back to allow insertion of a fastener. The ends of the roofing material are first fastened to the roof or parapet to be covered. The intervening portion of the roofing material is then fastened. The tabs affixed to the outside of the roofing material cover the fasteners and can be sealed shut to waterproof the roofing material. | 4 |
TECHNICAL FIELD
The present invention relates generally to optical systems and, more particularly, to a display structure that uses destructive interference of light to cost-effectively reduce reflections at higher-refractive index layers within an optical system.
BACKGROUND OF THE INVENTION
Many optical systems contain layers of contrasting refractive index, n. This gives rise to reflections within the system, diverting incident light from its designed path, decreasing efficiency and increasing noise. More particularly, several systems contain a higher-refractive index medium surrounded by two lower-refractive index media. In some such systems the higher-index medium is thin enough so that interference between reflections at the two surfaces of the higher-index layer can take place, constructively or destructively, depending on the optical path difference.
One such system illustrated in FIG. 1 is a liquid crystal display (LCD), where one indium-tin-oxide (ITO) electrode, 102 , with n≈1.95, lies between layers of liquid crystal (LC), 104 , with n≈1.53, and glass or color filter (CF), 101 , with n≈1.53, and the other lies between LC, 104 and a planarizing resin, 108 , with n≈1.59. There is also a thin layer of polyimide (PI), 103 , with n≈1.70, between the LC and each ITO electrode. There are also layers of silicon nitride, 105 , with n≈2.04, between layers of silica, 106 , with n≈1.55 and/or the planarizing resin. The silica and silicon nitride layers are used as dielectric and for passivation in and around the thin-film transistor (TFT) system. Glass, 107 , supports the structure. This is one typical structure in use in the industry.
Reflection of ambient light at a display device undesirably reduces the contrast of the image seen by a viewer. Anti-reflection coatings (ARCs) are used on the front surface of displays, which can reduce its reflectivity to less than 1%. However, reflections arise within the device, particularly at the ITO electrodes and silicon nitride layers, which also contribute to the degradation of the image in a brightly lit room. ARCs for the outer surfaces of optical systems have been studied in detail. One is described, for example, in U.S. Pat. No. 6,207,263.
Concerning interfaces within an optical system, that which has received most attention is a single interface, between a lower-refractive index medium and a higher-refractive index medium.
U.S. Pat. No. 5,061,874 describes a layer introduced between two media, together with a roughening of the interfaces, to reduce specular reflection.
Within the field of LCDs, several specific situations have been investigated, with a view to reducing reflections. Reducing reflections at a glass-semiconductor interface is the subject of US Patent Application No. 2006/0197096A. A structure which uses destructive interference of light to make a ‘black matrix’ effective as an absorber is claimed in U.S. Pat. No. 7,167,221. US Patent Application No. 2004/0109305A describes ARCs used on the elements of an LCD backlight which are in contact with air.
WO 2004/044998 describes a design for an organic light emitting diode (OLED). All of the layers, an outermost layer and the internal, light-emitting layers, have thicknesses chosen, according to their refractive index, to result in destructive interference of ambient light in reflection.
Finally, U.S. Pat. No 7,215,075 describes a structure that reduces reflections at the cathode of an OLED, which has a higher refractive index than its surrounding media. The method according to U.S. Pat. No. 7,215,075 is to replace the single cathode layer with an even number of layers, which have alternating high and low refractive indices.
SUMMARY OF THE INVENTION
A device and method in accordance with the present invention can be used in an optical system, such as a liquid crystal display, to minimize internal reflections. More particularly, the device and method in accordance with the present invention provide a structure that includes a first layer formed between a second and third layer, wherein a refractive index of the first layer is greater than a refractive index of the second and third layers. Further, a fourth layer is formed on one side of the second layer, and a fifth layer is formed on one side of the third layer, wherein the fourth and fifth layers have a lower refractive index than the second and third layers, respectively. The device and method in accordance with the present invention reduce internal reflections of an optical device while utilizing fewer layers relative to conventional optical devices. Additionally, a display device, such as an LCD, employing principles in accordance with the present invention is less costly to produce relative to conventional LCD devices.
According to one aspect of the invention, a structure for reducing internal reflections in an optical system includes a stack of layers including a first layer having a first refractive index, a second layer having a second refractive index, a third layer having a third refractive index, a fourth layer having a fourth refractive index, and a fifth layer having a fifth refractive index, wherein the second layer is arranged between the first layer and the third layer, and the fourth layer is arranged between the third layer and fifth layer, and wherein the third refractive index is numerically greater than the second and fourth refractive indexes, the second refractive index is numerically greater than the first refractive index, and the fourth refractive index is numerically greater than the fifth refractive index.
According to one aspect of the invention, the second refractive index is different from fourth refractive index.
According to one aspect of the invention, the first refractive index is different from the fifth refractive index.
According to one aspect of the invention, at least one layer comprises liquid crystal layer.
According to one aspect of the invention, the first layer comprises a color filter, the second layer comprises a polymide, the third layer comprises an indium-tin-oxide electrode, the fourth layer comprises a polymide and the fifth layer comprises a liquid crystal layer.
According to one aspect of the invention, the first layer comprises a liquid crystal material, the second layer comprises a polymide, the third layer comprises an indium-tin-oxide electrode, the fourth layer comprises a polymide and the fifth layer comprises a planarizing layer.
According to one aspect of the invention, the first layer comprises a planarizing layer, the second layer comprises a polymide, the third layer comprises a silicon nitride layer, the fourth layer comprises a polymide and the fifth layer comprises a silica layer layer.
According to one aspect of the invention, the respective layers are optimized to minimize total reflectivity by destructive interference.
According to one aspect of the invention, the structure further includes at least one of silica or silicon nitride arranged in the stack, and a light transmission path through the stack, wherein the at least one of silica or silicon nitride are arranged outside of the light transmission path.
According to one aspect of the invention, the second and/or fourth layers comprise at least one of polycarbonate, polystyrene, or indium zinc oxide.
According to one aspect of the invention, a display device includes a support, and the structure in accordance with the invention is arranged over the support.
According to one aspect of the invention, the support comprises glass.
According to one aspect of the invention, the display device is at least one of a liquid crystal display, an organic light emitting diode display, or an electrowetting display.
According to one aspect of the invention, a method for minimizing internal reflections in an optical device is provided, the optical device including a stack of layers, the stack comprising a first layer having a first refractive index, a second layer having a second refractive index, and a third layer having a third refractive index, the second layer formed between the first and third layer, wherein the second refractive index is numerically greater than the first refractive index and third refractive index, the method includes: forming a fourth layer having a fourth refractive index between the first and second layers, and forming a fifth layer having a fifth refractive index between the second and third layers, wherein the second refractive index is numerically greater than the fourth refractive index and the fifth refractive index, the fourth refractive index is numerically greater than the first refractive index, and the fifth refractive index is numerically greater than the third refractive index.
According to one aspect of the invention, the method includes selecting the fourth layer and fifth layer such that the fourth layer's refractive index is different from fifth layer's refractive index.
According to one aspect of the invention, the method includes optimizing the respective layers of the stack to minimize total reflectivity in the optical device by destructive interference.
According to one aspect of the invention, the method includes forming the second layer to a thickness such that an amplitude of total light reflected at the second layer depends on a phase difference between waves reflected from different surfaces of the second layer.
To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary optical structure of an LCD system.
FIG. 2 illustrates an exemplary optical structure that includes a higher-refractive index layer between two lower-refractive index media.
FIG. 3 illustrates an exemplary optical structure that includes intermediate-refractive index layers to reduce reflections in the optical system in accordance with an embodiment of the present invention.
FIG. 4 illustrates a conventional two-layer optical system designed to reduce reflections relative to the one-layer system of FIG. 2 .
FIG. 5 illustrates a conventional four-layer optical system with alternating layers designed to reduce reflections relative to the one-layer system of FIG. 2 .
FIG. 6 illustrates an exemplary LCD structure that includes intermediate-refractive index layers in accordance with an embodiment of the present invention.
FIG. 7 illustrates an alternative LCD structure to the structure of FIG. 1
FIG. 8 illustrates the LCD structure of FIG. 7 with intermediate-refractive index layers in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The principles of the invention will now be described with reference to the drawings. Because the invention was conceived and developed for use in liquid crystal display systems, it will be herein described chiefly in this context. However, the principles of the invention in their broader aspects can be adapted to other types of optical systems, such as, for example, organic light emitting diode (LED) display systems and electrowetting display systems.
Referring to FIG. 2 , there is shown an exemplary optical structure to which principles in accordance with the present invention can be applied. As shown in FIG. 2 , a higher-refractive index layer (e.g., media having a refractive index that is numerically greater than the refractive index of other media), HI, is surrounded by lower-refractive index layers (e.g., media having a refractive index that is numerically less than the refractive index of HI), LI 1 and LI 2 , which may have the same or different refractive indices. The thickness of the higher-refractive index layer is such that the total reflected power is a result of interference between the two reflections at the surfaces of the higher-refractive index layer (there is a maximum thickness of the HI layer for which this is true, dependent on the coherence of the light).
Moving to FIG. 3 , layers of intermediate refractive index, MI 1 and MI 2 , are applied to each side of the higher-refractive index layer HI, in between the higher refractive index layer and the lower-refractive index surrounding media LI 1 and LI 2 . MI 1 and MI 2 may have the same or different refractive indices.
The device in accordance with FIG. 3 reduces reflections at a higher-refractive index layer, surrounded by lower-refractive index media in an optical system. Further, the device in accordance with FIG. 3 reduces reflections more effectively than 2-, 4- and 6-layer systems, such as those described in U.S. Pat. No. 7,215,075. This will now be demonstrated below.
The following results have been obtained using a downhill simplex, numerical method of multidimensional minimization, as described in Press, W. H., et al., ‘Numerical recipes in C: the art of scientific computing’, second edition (Cambridge University Press, 1992), pages 408-412. The reflectivities are calculated for light at normal incidence, using a calculation as found in Smith, W. J., ‘Modern Optical Engineering’, third edition (McGraw-Hill, 2000), pages 205-207 (equation 7.32 has been corrected to agree with equations 7.30 and 7.31). They are averaged for a flat spectrum from 450 nm to 750 nm. Average reflectivity (hereafter referred to as ‘reflectivity’) is minimized with respect to refractive indices, where they are unknown, and thicknesses of the layers. The above-referenced portions of both Press and Smith are hereby incorporated by reference.
a) Referring to FIG. 2 , consider the case of a layer, HI, with n=1.95, surrounded by media, LI 1 and LI 2 , both with n=1.50. The minimum reflectivity at HI, with respect to its thickness, is then 0.013. HI is 148 nm thick in this case. The reflectivity is so low, despite the refractive index contrast between HI and LI 1 and LI 2 , due to destructive interference of light reflected at the two surfaces of HI.
In accordance with the present invention, and as noted above, two extra layers of intermediate refractive index can be added to the system of FIG. 2 . These are MI 1 and MI 2 as shown in FIG. 3 . The reflectivity of the new, three-layer system (Hi, MI 1 and MI 2 form the three layers) can be minimized to 0.00005, i.e., reflectivity is reduced by a factor of 3000 relative to the device of FIG. 2 . The refractive indices of MI 1 and MI 2 in this case are both 1.66 and their thicknesses are 85 nm. HI (with n=1.95) is 145 nm thick.
In a method related to that of U.S. Pat. No. 7,215,075, a single extra layer, E, could instead be added to the system, as shown in the conventional optical structure of FIG. 4 . In this two-layer case (HI and E form the two layers), the minimum possible reflectivity is 0.0084 and the extra layer has refractive index 1.61. Comparing the above results obtained with respect to the two layer system of FIG. 4 to the results for the device in FIG. 3 , the reduction in reflectivity of a two-layer solution is improved by a factor of 170 in this case.
b) To make a comparison with the next simplest embodiment of U.S. Pat. No. 7,215,075, the materials used in the examples of U.S. Pat. No. 7,215,075 are examined. This is a four-layer system, with alternating higher and lower refractive indices, and is shown in FIG. 5 (layers Y, X, Y, and X form the four layers). L 1 and L 2 are the media surrounding the four layers. Each alternating layer is composed of either medium X or Y.
The examples in U.S. Pat. No. 7,215,075 use X and Y with refractive index 1.8 and 2.2. L 1 and L 2 are not specified, so this configuration cannot be compared fully with the embodiment shown in FIG. 3 . L 1 and L 2 are here taken to be 1.50. Using the multi-dimensional minimization algorithm to vary the thicknesses in this four-layer structure, the reflectivity at these layers (surrounded by media L 1 and L 2 ) can be minimized to 0.018.
The same materials used in the above example can be used in the device in accordance with the present invention, e.g. in a three-layer system as described herein. The refractive index of HI is 2.2 in this case, those of MI 1 and MI 2 are both 1.8, and those of LI 1 and LI 2 are both 1.50. The reflectivity at the three layers can be minimized, with respect to thicknesses of the layers, to 0.0017.
Thus, using the same materials with the device in accordance with the present invention as opposed to the four-layer embodiment of U.S. Pat. No. 7,215,075, the reflectivity is reduced by an order of magnitude.
c) Referring to FIG. 5 , a four-layer system is now considered having the refractive indices of L 1 being 1.50, that of L 2 being 1.60 and those of X and Y being 1.70 and 1.95, respectively. The four-layer system then has a minimum reflectivity of 0.0039.
The three-layer system in accordance with the present invention, using the same materials, i.e., refractive indices of 1.70, 1.95 and 1.70 for MI 1 , HI and MI 2 in FIG. 3 , allows a minimum reflectivity of 0.00056. The reflectivity is again reduced, this time by a factor of 7, compared with the use of the same materials according to the four-layer embodiment of U.S. Pat. No. 7,215,075.
A six-layer alternating system (also an embodiment of U.S. Pat. No. 7,215,075), using refractive indices 1.70 and 1.95 allows a minimum reflectivity of 0.0037.
Considering all of these results, it can be seen that when a higher-refractive index layer is surrounded by lower-refractive index media, the device in accordance with the present invention offers superior reduction of reflections when compared to solutions according to U.S. Pat. No. 7,215,075.
The device in accordance with the present invention will be described more fully hereinafter with reference to the accompanying drawings. The principles in accordance with the present invention, however, may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Embodiment One
Referring to FIG. 1 , there is shown an example of an optical structure embodied as a liquid crystal display (LCD), where one ITO electrode, 102 , with n≈1.95, lies between layers of liquid crystal (LC), 104 , with n≈1.53, and glass or color filter (CF), 101 , with n≈1.53, and the other lies between LC, 104 and a planarizing resin, 108 , with n≈1.59. There is also a thin layer of polyimide (PI), 103 , with n≈1.70, between the LC and each ITO electrode. There are also layers of silicon nitride, 105 , with n≈2.04, between layers of silica, 106 , with n≈1.55 and/or the planarizing resin. The silica and silicon nitride layers are used as dielectric and for passivation in and around the TFT system. Glass, 107 , supports the structure. This is one typical structure in use in the industry, and is also described in Table 1, with thickness also given for each layer.
TABLE 1
Label in
Refractive index
Material
FIG. 1
(approximate)
Thickness
Color filter (CF)
101
1.50
>10 μm
ITO
102
1.95
138 nm
Polyimide (PI)
103
1.70
70 nm
LC
104
1.53
3 μm
Polyimide (PI)
103
1.70
76 nm
ITO
102
1.95
138 nm
Planarizing resin
108
1.59
2.5 μm
Silicon nitride
105
2.04
330 nm
Silica
106
1.55
700 nm
Silicon nitride
105
2.04
300 nm
Silica
106
1.55
380 nm
Glass
107
1.53
>10 μm
The structure described in Table 1 has thicknesses of PI and ITO optimized to minimize total reflectivity by destructive interference. (These thicknesses are within the typical manufacturing range.) The total reflectivity of this structure is 0.104; 10.4% of incident light is reflected by this internal structure.
Referring now to FIG. 6 , extra layers of intermediate refractive index, 601 , 602 , 603 , 604 , 605 and 606 , can be placed between higher- and lower-refractive index layers. For example, 601 is inserted between the ITO and CF, forming the structure of FIG. 3 in accordance with the invention, together with the LC and PI. Table 2 describes the case where the layers 601 , 602 , 603 , 604 , 605 and 606 are polyimide, with n≈1.70.
The structure described in Table 2 has thicknesses of PI and ITO optimized to minimize total reflectivity by destructive interference. The total reflectivity of this structure is 0.0091; 0.91% of incident light is reflected by this internal structure. Therefore, using a device in accordance with the invention, wherein polyimide is used as the intermediate-refractive index material, has reduced the reflectivity of this LCD structure by a factor of 11.
TABLE 2
Refractive index
Material
(approximate)
Thickness
Color filter (CF)
1.50
>10 μm
Polyimide (PI)
1.70
81 nm
ITO
1.95
138 nm
Polyimide (PI)
1.70
81 nm
LC
1.53
3 μm
Polyimide (PI)
1.70
80 nm
ITO
1.95
138 nm
Polyimide (PI)
1.70
82 nm
Planarizing resin
1.59
2.5 μm
Polimide (PI)
1.70
84 nm
Silicon nitride
2.04
330 nm
Polyimide (PI)
1.70
77 nm
Silica
1.55
700 nm
Polyimide (PI)
1.70
75 nm
Silicon nitride
2.04
300 nm
Polyimide (PI)
1.70
80 nm
Silica
1.55
380 nm
Glass
1.53
>10 μm
If the refractive index of layers 601 , 602 , 603 , 604 , 605 and 606 can be freely chosen, as well as their thickness, the structure of Table 3 results (the question marks in table 3 indicate that materials having appropriate refractive index can be freely chosen).
The structure described in Table 3 has refractive indices of layers 601 , 602 , 603 , 604 , 605 and 606 and thicknesses of PI, ITO and layers 601 , 602 , 603 , 604 , 605 and 606 optimized to minimize total reflectivity by destructive interference. The total reflectivity of this structure is 0.0050; 0.50% of incident light is reflected by this internal structure. Therefore, using a device in accordance with the invention, wherein polyimide is used as the intermediate-refractive index material, has reduced the reflectivity of this LCD structure by a factor of 21.
TABLE 3 Refractive index Material (approximate) Thickness Color filter (CF) 1.50 >10 μm ? 1.68 81 nm ITO 1.95 139 nm Polyimide (PI) 1.70 80 nm LC 1.53 3 μm Polyimide (PI) 1.70 81 nm ITO 1.95 142 nm ? 1.73 82 nm Planarizing resin 1.59 2.5 μm ? 1.77 81 nm Silicon nitride 2.04 330 nm ? 1.70 86 nm Silica 1.55 700 nm ? 1.79 70 nm Silicon nitride 2.04 300 nm ? 1.76 75 nm Silica 1.55 380 nm Glass 1.53 >10 μm
Embodiment 2
It is also possible to remove the silica and/or silicon nitride from the areas through which light is transmitted in an LCD. This is because they are only required around the TFT and circuitry in the device. Light is not transmitted through these regions (it is either reflected by metal or absorbed in the commonly used black mask), and so they can be considered irrelevant for purposes of reducing internal reflections. The silica and silicon nitride can in principle be patterned so that they are only found in these opaque regions, not in the transparent part of the pixel. In this case, the structure is as given in Table 4 and FIG. 7 .
The structure described in Table 3 has the thicknesses of PI and ITO optimized to minimize total reflectivity by destructive interference. The total reflectivity of this structure is 0.015; 1.5% of incident light is reflected by this internal structure.
TABLE 4
Label in
Refractive index
Material
FIG. 7
(approximate)
Thickness
Color filter (CF)
101
1.50
>10 μm
ITO
102
1.95
134 nm
Polyimide (PI)
103
1.70
49 nm
LC
104
1.53
3 μm
Polyimide (PI)
103
1.70
60 nm
ITO
102
1.95
134 nm
Planarizing resin
108
1.59
2.5 μm
Silica
106
1.55
380 nm
Glass
107
1.53
>10 μm
Referring to FIG. 8 , extra layers of intermediate refractive index, 801 and 802 can be placed between higher- and lower-refractive index layers of the system of FIG. 7 . For example, 801 can be inserted between the ITO and CF, forming the structure of FIG. 3 in accordance with the present invention, together with the LC and PI. Table 5 describes the case where 801 and 802 are polyimide layers, with n≈1.70.
TABLE 5
Refractive index
Material
(approximate)
Thickness
Color filter (CF)
1.50
>10 μm
Polyimide (PI)
1.70
74 nm
ITO
1.95
122 nm
Polyimide (PI)
1.70
74 nm
LC
1.53
3 μm
Polyimide (PI)
1.70
81 nm
ITO
1.95
142 nm
Polyimide (PI)
1.70
83 nm
Planarizing resin
1.59
2.5 μm
Silica
1.55
380 nm
Glass
1.53
>10 μm
The structure described in Table 5 has thicknesses of PI and ITO optimized to minimize total reflectivity by destructive interference. The total reflectivity of this structure is 0.00080; 0.50% of incident light is reflected by this internal structure. Therefore, using the device in accordance with the invention, wherein polyimide is used as the intermediate-refractive index material, has reduced the reflectivity of this LCD structure by a factor of 19.
Other Intermediate-Refractive Index Materials AND Embodiments
For such use in an LCD, or other system, other materials, organic and inorganic may be found which have an appropriate refractive index. Polycarbonate (n≈1.59), polystyrene (n≈1.59) are two examples of polymers which may be used between some layers. Indium zinc oxide can be deposited with a refractive index of 1.8 (according to U.S. Pat. No. 7,215,075). Additionally, the structure in accordance with the present invention can be utilized in liquid crystal display systems, as well as organic light emitting diode (OLED) display systems and electrowetting display systems.
Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications, and is limited only by the scope of the following claims. | A structure for reducing internal reflections in an optical system includes a stack of layers including a first layer having a first refractive index, a second layer having a second refractive index, a third layer having a third refractive index, a fourth layer having a fourth refractive index, and a fifth layer having a fifth refractive index. The second layer is arranged between the first layer and the third layer, and the fourth layer is arranged between the third layer and fifth layer. Further, the third refractive index is greater than the second and fourth refractive indexes, the second refractive index is greater than the first refractive index, and the fourth refractive index is greater than the fifth refractive index. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application and claims the benefit under 35 U.S.C. §371 of International Application No. PCT/US2008/006799 filed on May 29, 2008, entitled MEMBRANE CLEANING WITH PULSED AIRLIFT PUMP, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 60/940,507 entitled MEMBRANE CLEANING WITH PULSED AIRLIFT PUMP, filed on May 29, 2007, each of which is herein incorporated by reference in their entirety and to which this application claims the benefit of priority.
TECHNICAL FIELD
The present invention relates to membrane filtration systems and, more particularly, to apparatus and related methods to effectively clean the membranes used in such systems by means of pulsed fluid flow.
BACKGROUND OF THE INVENTION
The importance of membranes for treatment of wastewater is growing rapidly. It is now well known that membrane processes can be used as an effective tertiary treatment of sewage and provide quality effluent. However, the capital and operating cost can be prohibitive. With the arrival of submerged membrane processes where the membrane modules are immersed in a large feed tank and filtrate is collected through suction applied to the filtrate side of the membrane or through gravity feed, membrane bioreactors combining biological and physical processes in one stage promise to be more compact, efficient and economic. Due to their versatility, the size of membrane bioreactors can range from household (such as septic tank systems) to the community and large-scale sewage treatment.
The success of a membrane filtration process largely depends on employing an effective and efficient membrane cleaning method. Commonly used physical cleaning methods include backwash (backpulse, backflush) using a liquid permeate or a gas or combination thereof, membrane surface scrubbing or scouring using a gas in the form of bubbles in a liquid. Typically, in gas scouring systems, a gas is injected, usually by means of a blower, into a liquid system where a membrane module is submerged to form gas bubbles. The bubbles so formed then travel upwards to scrub the membrane surface to remove the fouling substances formed on the membrane surface. The shear force produced largely relies on the initial gas bubble velocity, bubble size and the resultant of forces applied to the bubbles. To enhance the scrubbing effect, more gas has to be supplied. However, this method consumes large amounts of energy. Moreover, in an environment of high concentration of solids, the gas distribution system may gradually become blocked by dehydrated solids or simply be blocked when the gas flow accidentally ceases.
Furthermore, in an environment of high concentration of solids, the solid concentration polarisation near the membrane surface becomes significant during filtration where clean filtrate passes through membrane and a higher solid-content retentate is left, leading to an increased membrane resistance. Some of these problems have been addressed by the use of two-phase flow to clean the membrane.
Cyclic aeration systems which provide gas bubbles on a cyclic basis are claimed to reduce energy consumption while still providing sufficient gas to effectively scrub the membrane surfaces. In order to provide for such cyclic operation, such systems normally require complex valve arrangements and control devices which tend to increase initial system cost and ongoing maintenance costs of the complex valve and switching arrangements required. Cyclic frequency is also limited by mechanical valve functioning in large systems. Moreover, cyclic aeration has been found to not effectively refresh the membrane surface.
It would be desirable to provide an energy efficient operation of the scouring process without the need to control the operation by means of complex valve switching etc. It is also preferable to provide a two-phase liquid gas flow past the membrane surfaces to provide a more effective scouring process while minimising energy requirements for such a cleaning process.
DISCLOSURE OF THE INVENTION
The present invention, at least in its embodiments, seeks to overcome or least ameliorate some of the disadvantages of the prior art or at least provide the public with a useful alternative.
According to one aspect, the present invention provides a method of cleaning a membrane surface immersed in a liquid medium with a fluid flow, including the steps of providing a randomly generated intermittent or pulsed fluid flow along said membrane surface to dislodge fouling materials therefrom and reduce the solid concentration polarisation. For preference, the fluid flow includes a gas flow. Preferably, the gas flow is in the form of gas bubbles. For further preference, the fluid flow includes a two phase gas/liquid flow. Preferably, the method includes producing the pulsed two-phase gas/liquid flow using a device supplied with a flow of pressurised gas. For further preference, the supply of pressurised gas flow is essentially constant. Preferably, the pulsed fluid flow is random in magnitude and/or frequency and/or duration.
In one form of the invention, the pulsed two-phase gas/liquid flow is used in conjunction with an essentially constant two-phase gas/liquid flow.
Optionally, an additional source of bubbles may be provided in said liquid medium by means of a blower or like device. The gas used may include air, oxygen, gaseous chlorine, ozone, nitrogen, methane or any other gas suitable for a particular application. Air is the most economical for the purposes of scrubbing and/or aeration. Gaseous chlorine may be used for scrubbing, disinfection and enhancing the cleaning efficiency by chemical reaction at the membrane surface. The use of ozone, besides the similar effects mentioned for gaseous chlorine, has additional features, such as oxidizing DBP precursors and converting non-biodegradable NOM's to biodegradable dissolved organic carbon. In some applications, for example, an anaerobic biological environment or a non-biological environment where oxygen or oxidants are undesirable, nitrogen may be used, particularly where the feed tank is closed with ability to capture and recycle the nitrogen.
According to a second aspect, the present invention provides a membrane module comprising a plurality of porous membranes or a set of membrane modules and means for providing a randomly generated, pulsed fluid flow such that, in use, said fluid flow moves past the surfaces of said membranes to dislodge fouling materials therefrom. For preference, the fluid flow includes a gas flow which generates bubbles which move past the surfaces of said membranes. For further preference, the fluid flow includes a two phase gas/liquid flow. Preferably, said pulsed two-phase gas/liquid flow is produced by a device provided with an essentially constant supply of gas. Preferably, the pulsed fluid flow is random in magnitude and/or frequency and/or duration.
Where a set of membrane modules are used, the modules are generally assembled in an array, rack or a cassette located in a feed containing vessel or tank. To clean a rack or a cassette of membrane modules, the device for providing the pulsed gas or two-phase gas/liquid flow can be connected to a distributor and the pulsed gas bubbles generated are distributed into the modules through the distributor. It is preferred to arrange one device to one module or to a small number of modules. Accordingly, there typically are a number of devices installed for one rack or cassette. Gas is preferably supplied to the rack and then distributed to each device along the rack manifold. Although the gas is supplied to individual device in a continuous mode, the eruption of gas bubbles from the devices along the rack is produced at random times, keeping the membrane tank feed essentially constantly in an unstable condition. This effect reduces solid concentration polarisation and hence the filtration resistance. When looking down from the top of a rack, gas bubbles appear randomly from different modules within the rack, forming a random distribution pattern.
Even where the gas supply to the rack is continuous and at the same flow rate, the volumetric gas flow to an individual module generally fluctuates in a small range, generally in less than 15%. This is due to the variation in back pressure inside the pulsed gas-lift device.
For preference, the membranes comprise porous hollow fibers, the fibers being fixed at each end in a header, the lower header having one or more holes formed therein through which the two-phase gas/liquid flow is introduced. The holes can be circular, elliptical or in the form of a slot. The fibers are normally sealed at one end (usually, the lower end) and open at their other end to allow removal of filtrate, however, in some arrangements, the fibers may be open at both ends to allow removal of filtrate from one or both ends. The sealed ends of the fibers may be potted in a potting head or may be left unpotted. The fibers are preferably arranged in mats, cylindrical arrays or bundles. It will be appreciated that the cleaning process described is equally applicable to other forms of membrane such flat or plate membranes.
For further preference, the membranes comprise porous hollow fibers, the fibers being fixed at each end in a header to form a sub-module. A set of sub-modules are assembled to form a module. Between sub-modules, one or more holes are left to allow the passage or distribution of gas/liquid into the sub-modules.
According to one preferred form, the present invention provides a method of removing fouling materials from the surface of a plurality of porous hollow fiber membranes mounted and extending longitudinally in an array to form a membrane module, said membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the method comprising the steps of providing a generally random, uniformly distributed pulsed gas bubble flow past the surfaces of said membranes, said distribution being such that said bubbles flow substantially uniformly between each membrane in said array to scour the surface of said membranes and remove accumulated solids from within the membrane module.
For preference, gas bubble flow further includes a two phase gas/liquid flow. Preferably, said pulsed two-phase gas/liquid flow is produced by a device provided with an essentially constant supply of gas. Preferably, the pulsed gas flow is random in magnitude and/or frequency and/or duration.
According to a third aspect the present invention provides a membrane module comprising a plurality of porous hollow fiber membranes, said fiber membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fiber membranes being fixed at each end in a header, one header having one or more openings formed therein through which a generally random pulsed fluid flow is introduced for cleaning the surfaces of said hollow fiber membranes.
For preference, the fluid flow includes a gas flow. For further preference, the gas flow is in the form of gas bubbles. For preference, gas flow includes a two phase gas/liquid flow. Preferably, said pulsed two-phase gas/liquid flow is produced by a device provided with an essentially constant supply of gas. Preferably, the pulsed fluid flow is random in magnitude and/or frequency and/or duration.
Preferably, the device includes a gaslift pump apparatus operative in response to said essentially constant supply of pressurized gas from a gas source connected thereto to store and randomly release pressurized gas and use the released pressurized gas to gaslift quantities of said liquid from a reservoir of liquid to produce said pulsed two-phase gas/liquid flow.
For preference, said gaslift pump apparatus includes an inverted gas storage chamber for storing said gas provided by said gas source and having a closed upper end and an open lower end positioned in said reservoir of liquid, a vertical riser tube having an inlet port in fluid communication with said reservoir of liquid and an outlet port in fluid communication with said membrane module, said riser tube having an opening in fluid communication with said gas storage chamber positioned for receiving said stored gas from said chamber when the level of gas within the chamber reaches a predetermined level and gaslifting the liquid through said riser tube for discharge into said module. Preferably, the vertical riser tube is located within the gas storage chamber.
In one embodiment of the invention, the supply of gas may be provided by an external tank containing pressurised gas, the tank being in fluid communication with the membrane module and having control means for providing randomly generated pulses of gas to the module to form said two phase gas/liquid flow for cleaning the membrane surfaces. In one embodiment, the control means may comprise a device positioned in a gas/liquid inlet to the membrane module and operable in dependence on the level of liquid in the inlet to provide gas from the external tank. For example, a float device could be used to activate the control means depending on the liquid level.
Preferably, the fibers may be protected and fiber movement is limited by a module support screen which has both vertical and horizontal elements appropriately spaced to provide unrestricted fluid and gas flow through the fibers and to restrict the amplitude of fiber motion reducing energy concentration at the potted ends of the fibers.
For preference, the module may be encapsulated in a substantially solid or liquid/gas impervious tube and connected to the pulsed gas-lift pump device so as to retain the two-phase gas/liquid flow within the module.
For preference, said openings comprise a slot, slots or a row of holes. Preferably, the fiber bundles are located in the potting head between the slots or rows of holes.
The liquid used may be the feed to the membrane module.
For preference, the pulse frequency of the randomly generated pulses varies in a range of generally from 0.1 to 200 seconds. It will be appreciated the pulse frequency is related to the structure of the device and with a particular structure, the pulse frequency preferably varies in a range of about 10 to about 300%.
Preferably, the pulsed gas-lift pump device can be optionally connected in fluid communication with a fluid distributor to substantially uniformly distribute the pulsed gas bubbles into the filtration module or modules.
Preferably, the fibers within the module have a packing density (as defined above) of between about 5 to about 80% and, more preferably, between about 8 to about 55%.
For preference, said holes have a diameter in the range of about 1 to 40 mm and more preferably in the range of about 1.5 to about 25 mm. In the case of a slot or row of holes, the open area is chosen to be equivalent to that of the above holes.
Typically, the fiber inner diameter ranges from about 0.1 mm to about 5 mm and is preferably in the range of about 0.25 mm to about 2 mm. The fibers wall thickness is dependent on materials used and strength required versus filtration efficiency. Typically wall thickness is between 0.05 to 2 mm and more often between 0.1 mm to 1 mm.
According to another aspect, the present invention provides a membrane bioreactor including a tank having means for the introduction of feed thereto, means for forming activated sludge within said tank, a membrane module according to the third aspect positioned within said tank so as to be immersed in said sludge and said membrane module provided with means for withdrawing filtrate from at least one end of said membranes.
According to yet another aspect, the present invention provides a method of operating a membrane bioreactor of the type described in the above aspect comprising introducing feed to said tank, applying a vacuum to said fibers to withdraw filtrate therefrom while providing said pulsed gas flow through aeration openings within said module such that, in use, said gas flow moves past the surfaces of said membrane fibers to dislodge fouling materials therefrom.
If required, a further source of aeration may be provided within the tank to assist microorganism activity. For preference, the membrane module is suspended vertically within the tank and said further source of aeration may be provided beneath the suspended module. Preferably, the further source of aeration comprises a group of air permeable tubes. The membrane module may be operated with or without backwash depending on the flux and feed condition. A high mixed liquor of suspended solids (5,000 to 20,000 ppm) in the bioreactor has been shown to significantly reduce residence time and improve filtrate quality. The combined use of aeration for both degradation of organic substances and membrane cleaning has been shown to enable constant filtrate flow without significant increases in transmembrane pressure while establishing high concentration of MLSS.
According to another aspect the present invention provides a water treatment system including a tank; a liquid chamber fluidly connected to the tank; a gas chamber fluidly connected to the liquid chamber; and a membrane module fluidly connected to the gas chamber.
Preferably the water treatment system includes a gas transfer system having a suction side connected to the liquid chamber and a discharge side connected to the gas chamber. For preference, a source of gas fluidly is connected to the liquid chamber. Preferably the system includes a membrane module vessel containing the membrane module and the membrane module vessel is hydraulically connected to the tank.
According to another aspect the invention provides a water treatment system comprising a liquid reservoir fluidly connected to a source of water; a gas/liquid chamber enclosing a first compartment and a second compartment, the first compartment fluidly connected to the liquid reservoir; and a membrane separation vessel hydraulically connected to the second compartment.
For preference, the system includes a chamber hydraulically isolated from the membrane module and a gas source connected to the chamber.
Preferably the membrane module is immersed in a solid-containing liquid feed contained in a membrane tank, the membrane tank is hydraulically connected to the aeration zone which is fluidly connected to the chamber.
According to another aspect the present invention provides a method of scouring a membrane module including: providing a chamber having a first compartment and a second compartment; establishing a hydraulic seal between the first compartment and the membrane module; at least partially filling the first compartment with a liquid feed and introducing a gas into the chamber.
Preferably, the method includes breaking the hydraulic seal, wherein breaking the hydraulic seal releases at least a portion of the gas contained in the chamber to the membrane module and then re-establishing the hydraulic seal between the first compartment and the membrane module.
For preference, the method includes re-breaking and re-establishing the hydraulic seal to produce a pulsed release of at least a portion of the gas contained in the chamber.
Preferably, the method includes introducing liquid feed into the second compartment. In one form of the method, introduction of the gas into the chamber is performed continuously.
According to another aspect, the present invention provides a method of cleaning filtration membranes located in a vessel containing liquid by providing generally random pulses of fluid within the liquid at a number of locations within the vessel. Preferably, the pulses of fluid are random in magnitude and/or frequency and/or duration. For preference, the fluid includes gas. For further preference, the gas is in the form of gas bubbles. For preference, fluid includes a two phase gas/liquid mixture. Preferably, said pulsed two-phase gas/liquid mixture is produced by a device provided with an essentially constant supply of gas.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is a simplified schematic cross-sectional elevation view of a membrane module according to one embodiment of the invention;
FIG. 2 shows the module of FIG. 1 during the pulse activation phase;
FIG. 3 shows the module of FIG. 1 following the completion of the pulsed two-phase gas/liquid flow phase;
FIG. 4 is a simplified schematic cross-sectional elevation view of a membrane module according to second embodiment of the invention;
FIG. 5 is a simplified schematic cross-sectional elevation view of a water treatment system according to third embodiment of the invention;
FIG. 6 a simplified schematic cross-sectional elevation view of an array of membrane modules of the type illustrated in the embodiment of FIG. 1 ;
FIGS. 7A and 7B are a simplified schematic cross-sectional elevation views of a membrane module illustrating the operation levels of liquid within the pulsed gaslift device;
FIG. 8 is a simplified schematic cross-sectional elevation view of a membrane module of the type shown in the embodiment of FIG. 1 , illustrating sludge build up in the pulse gaslift pump;
FIG. 9 a simplified schematic cross-sectional elevation view of a membrane module illustrating one embodiment of the sludge removal process;
FIG. 10 is a graph of the pulsed liquid flow pattern and air flow rate supplied over time; and
FIG. 11 is a graph of membrane permeability over time comparing cleaning efficiency using a gaslift device and a pulsed gaslift device according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings, FIGS. 1 to 3 show a membrane module arrangement according to one embodiment of the invention.
The membrane module 5 includes a plurality of permeable hollow fiber membranes bundles 6 mounted in and extending from a lower potting head 7 . In this embodiment, the bundles are partitioned to provide spaces 8 between the bundles 6 . It will be appreciated that any desirable arrangement of membranes within the module 5 may be used. A number of openings 9 are provided in the lower potting head 7 to allow flow of fluids therethrough from the distribution chamber 10 positioned below the lower potting head 7 .
A pulsed gas-lift pump device 11 is provided below the distribution chamber 10 and in fluid communication therewith. The pulsed gas-lift pump device 11 includes an inverted gas collection chamber 12 open at its lower end 13 and having a gas inlet port 14 adjacent its upper end. A central riser tube 15 extends through the gas collection chamber 12 and is fluidly connected to the base of distribution chamber 10 and open at its lower end 16 . The riser tube 15 is provided with an opening or openings 17 partway along its length. A tubular trough 18 extends around and upward from the riser tube 15 at a location below the openings 17 .
In use, the module 5 is immersed in liquid feed 19 and source of pressurized gas is applied, essentially continuously, to gas inlet port 14 . The gas gradually displaces the feed liquid 19 within the inverted gas collection chamber 12 until it reaches the level of the opening 17 . At this point, as shown in FIG. 2 , the gas breaks the liquid seal across the opening 17 and surges through the opening 17 and upward through the central riser tube 15 creating a pulse of gas bubbles and feed liquid which flows through the distribution chamber 10 and into the base of the membrane module 5 . The rapid surge of gas also sucks liquid through the base opening 16 of the riser tube 15 resulting in a high velocity two-phase gas/liquid flow. The two-phase gas/liquid pulse then flows through the openings 9 to scour the surfaces of the membranes 6 . The trough 18 prevents immediate resealing of the opening 17 and allows for a continuing flow of the gas/liquid mixture for a short period after the initial pulse.
The initial surge of gas provides two phases of liquid transfer, ejection and suction. The ejection phase occurs when the bubble slug is initially released into the riser tube 15 creating a strong buoyancy force which ejects gas and liquid rapidly through the riser tube 15 and subsequently through the membrane module 5 to produce an effective cleaning action on the membrane surfaces. The ejection phase is followed by a suction or siphon phase where the rapid flow of gas out of the riser tube 15 creates a temporary reduction in pressure due to density difference which results in liquid being sucked through the bottom 16 of the riser tube 15 . Accordingly, the initial rapid two-phase gas/liquid flow is followed by reduced liquid flow which may also draw in further gas through opening 17 .
The gas collection chamber 12 then refills with feed liquid, as shown in FIG. 3 , and the process begins again resulting in another pulsing of two-phase gas/liquid cleaning of the membranes 6 within the module 5 . Due to the relatively uncontrolled nature of the process, the pulses are generally random in frequency and duration.
FIG. 4 shows a further modification of the embodiment of FIGS. 1 to 3 . In this embodiment, a hybrid arrangement is provided where, in addition to the pulsed two-phase gas/liquid flow, a steady state supply of gas is fed to the upper or lower portion of the riser tube 15 at port 20 to generate a constant gas/liquid flow through the module 5 supplemented by the intermittent pulsed two-phase gas/liquid flow.
FIG. 5 shows an array of modules 35 and pump devices 11 of the type described in relation to the embodiment of FIGS. 1 to 3 . The modules 5 are positioned in a feed tank 36 . In operation, the pulses of gas bubbles produced by each pump device 11 occur randomly for each module 5 resulting in an overall random distribution of pulsed gas bubble generation within the feed tank 36 . This produces a constant but randomly or chaotically varying agitation of liquid feed within the feed tank 36 .
FIG. 6 shows an arrangement for use of the invention in a water treatment system using a membrane bioreactor. In this embodiment the pulsed two-phase gas liquid flow is provided between a bioreactor tank 21 and membrane tank 22 . The tanks are coupled by an inverted gas collection chamber 23 having one vertically extending wall 24 positioned in the bioreactor tank 21 and a second vertically extending wall 25 positioned in the membrane tank 22 . Wall 24 extends to a lower depth within the bioreactor tank 21 than does wall 25 within the membrane tank 22 . The gas collection chamber 23 is partitioned by a connecting wall 26 between the bioreactor tank 21 and the membrane tank 22 define two compartments 27 and 28 . Gas, typically air, is provided to the gas collection chamber 23 through port 29 . A membrane filtration module or device 30 is located within the membrane tank 22 above the lower extremity of vertical wall 25 .
In use, gas is provided under pressure to the gas collection chamber 23 through port 29 resulting in the level of water within the chamber 23 being lowered until it reaches the lower end 31 of wall 25 . At this stage, the gas escapes rapidly past the wall 25 from compartment 27 and rises through the membrane tank 22 as gas bubbles producing a two-phase gas/liquid flow through the membrane module 30 . The surge of gas also produces a rapid reduction of gas within compartment 28 of the gas collection chamber 23 resulting in further water being siphoned from the bioreactor tank 21 and into the membrane tank 22 . The flow of gas through port 29 may be controlled by a valve (not shown) connected to a source of gas (not shown). The valve may be operated by a controller device (not shown).
It will be appreciated the pulsed flow generating cleaning device described in the embodiments above may be used with a variety of known membrane configurations and is not limited to the particular arrangements shown. The device may be directly connected to a membrane module or an assembly of modules. Gas, typically air, is continuously supplied to the device and a pulsed two-phase gas/liquid flow is generated for membrane cleaning and surface refreshment. The pulsed flow is generated through the device using a continuous supply of gas, however, it will be appreciated where a non-continuous supply of gas is used a pulsed flow may also be generated but with a different pattern of pulsing.
In some applications, it has been found the liquid level inside a pulsed gas-lift pump device 11 fluctuates between levels A and B as shown in FIGS. 7A and 7B . Near the top end inside the gas-lift pump device 11 , there is typically left a space 37 that liquid phase cannot reach due to gas pocket formation. When such a pump device 11 is operated in high solid environment, such as in membrane bioreactors, scum and/or dehydrated sludge 39 may gradually accumulate in the space 37 at the top end of the pump device 11 and this eventually can lead to blockage of the gas flow channel 40 , leading to a reduced pulsing or no pulsed effect at all. FIG. 8 illustrates such a scenario.
Several methods to overcome this effect have been identified. One method is to locate the gas injection point 38 at a point below the upper liquid level reached during operation, level A in FIGS. 7A and 7B . When the liquid level reaches the gas injection point 38 and above, the gas generates a liquid spray 41 that breaks up possible scum or sludge accumulation near the top end of the pump device 11 . FIG. 9 schematically shows such an action. The intensity of spray 41 is related to the gas injection location 38 and the velocity of gas. This method may prevent any long-term accumulation of sludge inside the pump device 11 .
Another method is to periodically vent gas within the pump device 11 to allow the liquid level to reach the top end space 37 inside the pump device 11 during operation. In this case, the injection of gas must be at or near the highest point inside the pump device 11 so that all or nearly all the gas pocket 37 can be vented. The gas connection point 38 shown in FIG. 7 is an example. Depending on the sludge quality, the venting can be performed periodically at varying frequency to prevent the creation of any permanently dried environment inside the pump device.
It was also noted in operation of the pump device 11 that the liquid level A in FIG. 7 can vary according to the gas flowrate. The higher the gas flowrate, the less the gas pocket formation inside the pump device 11 . Accordingly, another method which may be used is to periodically inject a much higher air flow into the pump device 11 during operation to break up dehydrated sludge. Depending on the design of the device, the gas flowrate required for this action is normally around 30% or more higher than the normal operating gas flowrate. This is possible in some plant operations by diverting gas from other membrane tanks to a selected tank to temporarily produce a short, much higher gas flow to break up dehydrated sludge. Alternatively, a standby blower (not shown) can be used periodically to supply more gas flow for a short duration.
The methods described above can be applied individually or in a combined mode to get a long term stable operation and to eliminate any scum/sludge accumulation inside the pump device 11 .
EXAMPLES
One typical membrane module is composed of hollow fiber membranes, has a total length of 1.6 m and a membrane surface area of 38 m 2 . A pulsed flow generating device was connected to the typical membrane module. A paddle wheel flowmeter was located at the lower end of the riser tube to monitor the pulsed liquid flow-rate lifted by gas. FIG. 10 shows a snapshot of the pulsed liquid flow-rate at a constant supply of gas flow at 7.8 Nm 3 /hr. The snapshot shows that the liquid flow entering the module had a random or chaotic pattern between highs and lows. The frequency from low to high liquid flow-rates was in the range of about 1 to 4.5 seconds. The actual gas flow-rate released to the module was not measured because it was mixed with liquid, but the flow pattern was expected to be similar to the liquid flow—ranging between highs and lows in a chaotic nature.
A comparison of membrane cleaning effect via pulsed and normal airlift devices was conducted in a membrane bioreactor. The membrane filtration cycle was 12 minutes filtration followed by 1 minute relaxation. At each of the air flow-rates, two repeated cycles were tested. The only difference between the two sets of tests was the device connected to the module—a normal gaslift device versus a pulsed gaslift device. The membrane cleaning efficiency was evaluated according to the permeability decline during the filtration. FIG. 11 shows the permeability profiles with the two different gaslift devices at different air flow-rates. It is apparent from these graphs that the membrane fouling rate is less with the pulsed gaslift pump because it provides more stable permeability over time than the normal gaslift pump.
A further comparison was performed between the performance of a typical cyclic aeration arrangement and the pulsed gas lift aeration of the present invention. The airflow rate was 3 m 3 /h for the pulsed airlift, and 6 m 3 /h for the cyclic aeration. Cyclic aeration periods of 10 s on/10 s off and 3 s on/3 s off were tested. The cyclic aeration of 10 s on/10 s off was chosen to mimic the actual operation of a large scale plant, with the fastest opening and closing of valves being 10 s. The cyclic aeration of 3 s on/3 s off was chosen to mimic a frequency in the range of the operation of the pulsed airlift device. The performance was tested at a normalised flux of approximately 30 LMH, and included long filtration cycles of 30 minutes.
Table 1 below summarises the test results on both pulsed airlift operation and two different frequency cyclic aeration operations. The permeability drop during short filtration and long filtration cycles with pulsed airlift operation was much less significant compared to cyclic aeration operation. Although high frequency cyclic aeration improves the membrane performance slightly, the pulsed airlift operation maintained a much more stable membrane permeability, confirming a more effective cleaning process with the pulsed airlift arrangement.
TABLE 1
Effect of air scouring mode on membrane performance
Pulsed
10 s on/10 s off
3 s on/3 s off
Operation mode
airlift
cyclic aeration
cyclic aeration
Membrane permeability
1.4-2.2
3.3-6
3.6
drop during 12 minute
lmh/bar
lmh/bar
lmh/bar
filtration
Membrane permeability
2.5-4.8
10-12
7.6
drop during 30 minute
lmh/bar
lmh/bar
lmh/bar
filtration
The above examples demonstrate an effective membrane cleaning method with a pulsed flow generating device. With continuous supply of gas to the pulsed flow generating device, a random or chaotic flow pattern is created to effectively clean the membranes. Each cycle pattern of flow is different from the other in duration/frequency, intensity of high and low flows and the flow change profile. Within each cycle, the flow continuously varies from one value to the other in a chaotic fashion.
It will be appreciated that, although the embodiments described above use a pulsed gas/liquid flow, the invention is effective when using other randomly pulsed fluid flows including gas, gas bubbles and liquid.
It will be appreciated that further embodiments and exemplifications of the invention are possible without departing from the spirit or scope of the invention described. | A method of cleaning a membrane surface immersed in a liquid medium with a fluid flow, including the steps of providing a randomly generated intermittent or pulsed fluid flow along the membrane surface to dislodge fouling materials therefrom. A membrane module is also disclosed comprising a plurality of porous membranes ( 6 ) or a set of membrane modules ( 5 ) and a device ( 11 ) for providing a generally randomly generated, pulsed fluid flow such that, in use, said fluid flow moves past the surfaces of said membranes ( 6 ) to dislodge fouling materials therefrom. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to sheet conveying apparatus which is interconnected with sheet processing machinery. There is presently in use a new generation of sheet and document processing machinery which typically bursts preformed perforated webs into discreet sheets. These sheets are then conveyed along one or more feed paths leading to a sheet processing station such as a folding unit. Sheet processing machinery as such with folding units included, is increasingly being utilized in the modern office where space is at a premium among many other kinds of office equipment. It is therefore a trend that such machinery be designed in a more compact arrangement which compliments the modern office. The necessity for gaining service access to interior areas of the sheet processing machinery remains as a consideration for proper jam clearing capability, along with service requirements. It is with the foregoing in mind that the present invention has evolved in view of the following mentioned example of prior art.
2. Prior Art
U.S. Pat. No. 4,083,553, issued to Beck et al. Apr. 11, 1978 discloses a Copy Sheet Handling Apparatus for a Copier. One object of this patent is to provide means for accessing the copy sheet supply tray in a prescribed manner to avoid copy sheets from becoming misplaced during operator loading of additional sheets to the supply tray. This is accomplished partly by the use of a pivotable apparatus which maintains the feeding and sheet alignment devices in a predetermined sequence, thereby ensuring proper alignment of the sheets at the feeding position. While the referenced patent does provide access capability to the sheet feeding instrumentalities of the copier in this case, the device is not suitable for providing access in a sheet processing machine where a sheet, or series of sheets are conveyed along a path between modular units, since the patented bar device, aligning apparatus and restraining devices are designed for a one ended sheet feeding apparatus whereas the present invention must handle a stream flow of such sheets and yet be jam accessible as previously mentioned in the background of the invention.
SUMMARY OF THE INVENTION
There is a sheet conveying apparatus disclosed for transferring successive sheets of paper from a first sheet processing machine having a pair of substantially vertically oriented sheet feed rollers adjacent an output end. There is a second sheet processing machine having an input end located at the end which is opposite from the end disposed adjacent to the output feed rollers of the first sheet processing machine. The sheet conveying apparatus includes an elongate frame pivotally connected to the second sheet processing machine adjacent to the input end. The sheet conveying apparatus is normally disposed in a substantially horizontal position so that the frame normally overlies the second sheet processing machine. There is a sheet conveying device mounted on the frame, extending substantially the length of the frame for conveying sheets from the output end of the first sheet processing machine to the input end of the second sheet processing machine. A drive apparatus is operatively connected to the sheet conveying device, and is movably mounted on the free end of the frame for movement between an extended position in which the drive apparatus is engaged in driving relationship with the lower feed roller of the pair of feed rollers and is in interferring relationship with both the lower and upper feed rollers, thereby preventing upward movement of the free end of the frame. There is a retracted position in which the drive apparatus is disengaged from the lower feed roller and is out of interferring relationship with the lower and upper feed rollers, thereby permitting upward movement of the free end of the frame. A manually operable apparatus is provided for selectively moving the drive apparatus from the extended position to the retracted position so that the sheet conveying apparatus can be pivotally raised to an inclined position to facilitate operator access to the space beneath the sheet conveying apparatus.
The sheet conveying apparatus includes an endless belt and at least a first shaft supporting the belt, adjacent an inlet end of the frame. And, the drive apparatus includes a friction roller carried by a second shaft and an apparatus pivotally mounted on the frame adjacent to the inlet end thereof for supporting the second shaft in a position parallel to but spaced outwardly from the first shaft.
Having described the sheet conveying apparatus of the present invention, it is now presented that it is an object of the present invention to provide a way of conveying sheets from a first processing machine to a second processing machine such that access to adjacent working components of the second processing machine may be provided without disengaging the machines.
It is another object of the present invention to provide a sheet conveying apparatus having a manually disengagable drive for providing individual sheets to the operator as they are processed in the first sheet processing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a sheet processing machine including a bursting machine, a sheet conveying apparatus, a folding machine and an inserting machine.
FIG. 2 is a partial top view of the sheet conveying apparatus of FIG. 1.
FIG. 3 is an elevated, enlarged isometric view of the conveying apparatus taken from FIG. 2 along the lines of 3--3.
FIG. 4 is a partial sectional view of the sheet conveying apparatus as taken from FIG. 3.
FIG. 5 is a section view of the conveying apparatus as taken from FIG. 3 along the lines of 5--5.
FIG. 6 is a partial front view of the sheet conveying apparatus as taken from FIG. 3 along the lines of 6--6.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a front view of a sheet processing machine 10 which includes a bursting machine 12, a sheet conveying apparatus 14, a folding machine 18, and an inserting machine 22, all of which will be understood to be functional as a unit within the sheet processing machine 10. The sheet conveying apparatus 14 normally lies in a substantially horizontal position 26 such that it is parallel to ground. There is a retracted position 30 shown in FIG. 1, which represents the service position to gain access to a number of sheet buckle chutes 32 within the folding machine 18.
At this point it will be helpful to mention that a copending patent application, Ser. No. 569,413 entitled "Sheet Processing Apparatus" as assigned to Pitney Bowes Inc., will be useful insofar as explaining the detailed instrumentalities of the sheet processing machine 10. In this respect, a perforated web 34 is fed into the bursting machine 12 which then separates sheets from the web 34, and conveys the separated sheets through a pair of substantially vertically oriented sheet feed rollers 38, which are part of the bursting machine 12, hereinafter referred to as a first sheet processing machine. Similarly, the folding machine 18 will be referred to as a second sheet processing machine, having an input end 42, defined by a mating pair of rollers 46. There is an upper roller 50, which is drivingly located on a frame 54 (FIG. 2) of the second sheet processing machine 18 such that a roller 58, rotatably located on a support member 62 within the sheet conveying apparatus 14 (FIG. 3), normally engages the upper roller 50 when the sheet conveying apparatus 14 is disposed in the substantially horizontal position 26 illustrated in FIG. 1.
In FIG. 1, it is seen that the sheet conveying apparatus 14 is held upwards at the retracted position 30 by a suitable pivoting notched link member 66. In FIG. 3, there is shown a front wall 70 which partially obscures the operator's view of a handle member 74, unless the operator stands close to the front wall 70. The handle member 74 is suitably fastened to the sheet conveying apparatus 14. There is a manually operable apparatus 78 which an operator will grasp and move in a direction indicated by an arrow 80 in order to raise the sheet conveying apparatus 14 to the retracted position 30. The handle 74 is also grasped to rotate the apparatus 14 towards the retracted position 30. In FIG. 3, more details of the construction of the sheet conveying apparatus 14 is seen, including a pivot screw member 84, which secures the sheet conveying apparatus 14 as an assembly to the front wall 70, and similarly to a rear wall 88. There is a bent tab 92 formed from a lower structural member 96, in turn appropriately attached to an elongate U-shaped frame member 100 (FIG. 3). The frame member 100 forms the basic base assembly frame for the entire sheet conveying apparatus 14. There is a bar 104, appropriately attached to the front and rear wall 70 and 88 respectively, in order that a lower surface 108 of the U-shaped frame member 100 may rest in the aforementioned, substantially horizontal position 26. There is an upper cover member 112 which functions as a paper deck, located on a front side 116 of the sheet conveying apparatus 14, and is appropriately attached to the U-shaped frame member 100 by suitable screws and bent tabs as for example at a corner 120. The upper cover member 112 is similar to a rear upper cover member 124, which is fastened to the U-shaped frame member 100 in a manner similar to the member 112. There are appropriate sheet guide members, such as an angled member 128, which is slidably adjustable (there are two such members disposed at the front and rear of the sheet conveying apparatus 14), in a lateral direction 130 as opposed to a direction of sheet travel indicated by an arrow 132. The angled member 128 is normally held in a predetermined position by a lockscrew 134 which is typical of 4 such screws for adjusting the angled member 128.
Referring to FIG. 5, some more of the structural construction of the sheet conveying apparatus is seen. The upper cover member 112 and the rear upper cover member 124 both have vertical legs 136 and 140 respectively. The vertical legs 136 and 140 are appropriately secured to the U-shaped frame member 100 on an inside surface 102 and are elongated so as to reach along the entire length of the sheet conveying apparatus 14. Referring to FIG. 3 and FIG. 4, the legs 136 and 140 reach to an inlet end 144 of the sheet conveying apparatus sufficiently enough to rotatably support a first shaft 148 (FIG. 4), and another shaft 152 which is spaced outwardly from the first shaft 148 at an input end 150 to the second sheet processing machine 18 so as to suspend a pair of endless belts 156 on appropriate friction pulleys such as a pulley 160. The pulley 160 is appropriately fastened to the first shaft 148 by a setscrew or other similar device such that rotation of the first shaft 148 causes movement of the pair of belts 156 in the direction of the arrow 132. There are suitable oilless bearings such as a bearing 164 (FIG. 5) in the vertical leg 140 which rotatably supports the first shaft 148. The bearing 164 is used in other places of the sheet conveying apparatus 14, and will be referred to as other shafts are referred to in the remaining specification.
The first shaft 148 extends laterally beyond the vertical legs 136 and 140 sufficiently enough to hold a torsion spring 168 at both ends. The torsion spring 168 is applied at both ends of the shaft 148 and will be understood to be wound left and right hand in order to provide a moment 172, as indicated by a CW arrow in FIG. 4. The moment 172 is applied to a drive apparatus 176 (FIG. 4), such that a friction wheel 180 is resiliently biased in the clockwise direction given by the moment 172. The moment 172 is applied by a leg 173 of the spring 168 bearing against a grooved pulley 174 which is rotatably mounted on the second shaft 184. A leg 175 of the spring 168 bears against the upper cover member 112. The friction wheel 180 is rotatably mounted on a second shaft 184 and the second shaft 184 in turn is mounted in a bearing 164 which is fixedly located in separate flanges of a bracket 186. A flange 188 and a flange 190 support a bearing 164, in which the aforementioned second shaft 184 is suspended. The bracket 186 is pivotably suspended on the first shaft 148. There is a pinion gear 194 securely fastened to the shaft 148, and there is a gear 198 mounted on the second shaft 184 coaxially with the friction wheel 180. The gear 198 is suitably fastened to a metal portion 202 of the friction wheel 180 by appropriate screws such as a screw 206.
On FIG. 1, it is seen that the friction wheel 180 is in contact with a lower roller 210 of the vertically oriented sheet feed rollers 38 while the sheet conveying apparatus 14 is disposed in the substantially horizontal position 126.
In order for an operator to lift the sheet conveying apparatus 14, it is necessary that the manually operable apparatus 78 be moved in the diection of arrow 80 (FIGS. 1 and 4), until a bent sheet metal link member 214 (FIG. 4), engages a notch 218 which is located in a front upright wall 222 of the U-shaped frame member 100. The bent sheet metal link member 214 is pivotably mounted beneath the lower surface 108 of the U-shaped frame member 100 by a pin 226. The link member 214 is suitably bent to pass through a large aperture 230 (FIG. 4) which additionally accommodates a vertically disposed stud 234. The stud 234 protrudes beneath the level of the surface 108, and a suitable flexible cable 238 is suitably fastened to a groove 240 (FIG. 5) of the stud 234. A horizontal grooved pulley 244 (FIG. 4) and 248 are each rotatably fixed and mounted beneath surface 108 and the flexible cable 238 is strung around them as the cable 238 spans towards two vertically mounted pulleys 252 and 256. The pulleys 252 and 256 are each rotatably mounted on a vertical flange 260 of a U-shaped bracket 264 (FIG. 4). The U-shaped bracket 264 is spot welded to an underside surface 268 of the support member 62. Finally, the flexible cable 238 spans to the second shaft 184 and is firmly tied there.
It will now become evident that moving the manually operable apparatus 78 in the direction of the arrow 80 causes the friction wheel 180 to move away from the lower roller 210 of the vertically oriented sheet feed rollers 38 such that the sheet conveying apparatus 14 may be raised to the previously described retracted position 30. This retracted position 30 provides room and access for the machine operator to reach the sheet buckle chutes 32 of the folding machine 18, as previously described.
And, when the sheet conveying apparatus 14 is in the substantially horizontal position 26, the friction wheel 180 effectively engages the lower roller 210 of the verticaly oriented sheet feed rollers 38. Since the lower roller 210 is appropriately driven by a timing belt 272 which is itself driven by an (unshown) motor, the friction drive to the friction wheel 180 is effectively transferred. The drive apparatus 176 including the gear 198, and pinion gear 194 causes the first shaft 148 to turn and, the pulley 160 holding the previously defined pair of belts 156, thereby providing a conveyor for sheets.
Having described an embodiment of the present invention in detail in the foregoing specification, it will be understood that the sheet conveying apparatus provided herein overcomes obstacles otherwise preventing ready access to the instrumentalities of sheet processing machinery where major components of that machinery are separated. It is to be further understood that the invention is not to be limited to the specific embodiment disclosed herein, the same being merely illustrative of the base mode to carry out the invention, but rather that the invention is intended to cover all such modifications, variations and equivalents thereof as may be deemed to be within the scope of the following claims. | Sheet processing machinery including a bursting machine and a folding machine has a sheet conveying apparatus disposed there-between. The sheet conveying apparatus is pivotably mounted to allow service to an area adjacent to the input end of the following machine. A drive apparatus connected to the sheet processing machinery is disengaged to allow upward pivoting of the sheet conveying apparatus from a horizontal position to a retracted position, whereupon the service access may be achieved. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to ladders and, more particularly, to protective caps that secure over the ends of the rails of a ladder to protect the surface upon which the ladder leans when in use.
BACKGROUND OF THE INVENTION
[0002] Ladders have been used for decades by homeowners and commercial entities. Without a doubt, ladders provide great utility to those that use them. In decades past, most ladders were made of wood, but that has changed. Most ladders today are made of aluminum or fiberglass. Aluminum or fiberglass is desirable because the materials are lightweight and durable. Nonetheless, the rails that form the sides of the ladder have a tendency to cause damage to the surface upon which they are leaning. Further, hard plastic end pieces are often times used to protect the ends of the rails and are prone to damage the surface upon which they rest. It is not uncommon for the ladders to leave scratches and marks on, for example, vinyl siding.
[0003] Industry recognized this problem and, for a number of years, has offered protective caps that fit over the ends of the ladder rails. The caps are typically made from a pliable plastic. The caps serve to protect the surface upon which the ladder leans.
[0004] A problem, however, not addressed by the prior art is that ladder rails are not all sized the same. Thus, a protective cap designed to fit on one ladder rail will not fit on all ladder rails. If a user attempts to place a protective cap that is larger than the ladder rail cross-section, the cap will not fit securely on the ladder and can easily fall off the ladder rail. If a user attempts to place a protective cap on the ladder rail that is too small, it may not fit at all, or, if forced over the ladder rail, it may split after some time or during use. Further, the user often times does not know the size of the ladder rail. It is therefore much easier to buy a product that is adapted to fit over a broader range of varying sized side rails
SUMMARY OF THE INVENTION
[0005] This invention is directed to a protective ladder cap for fitting over the end of a rail of a ladder. The cap has an open end for fitting over the rail and a closed end. The cap has at least one elongated internal rib that tapers from a lower rib height closer to the open end than the closed end to a higher rib height closer to the closed end than the open end. In the preferred embodiment, the cap includes a plurality of internal ribs. The internal ribs also preferably comprise an indent portion adjacent the closed end of the rail to secure the cap on the ladder rail.
[0006] In the preferred embodiment, the protective ladder cap has two wide internal faces and two narrow internal faces. The internal ribs are on at least one of the wide internal faces, and preferably both. In an even more preferred embodiment, the internal ribs are on the narrow faces as well.
[0007] Because the internal ribs taper from a lower height to a higher height, the ladder cap is adapted to receive ladder rails of varying cross-section. Further, the tapered ribs ensure that the ladder cap is secured to the ladder, thus minimizing the ability of the ladder cap to fall off of the ladder rail. Because the ladder cap of the present invention is able to securely fit on ladder rails having varying cross-sections, consumers purchasing ladder caps are not required to know the cross-section size of their ladder rails. Thus, the ladder cap of the present invention also makes it much easier for consumers to purchase a ladder cap that fits snugly on the consumer's ladder.
[0008] These and other aspects of the invention are described more fully below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a perspective view of the ladder cap of the present invention shown as attached to the ends of the side rails of the ladder;
[0010] [0010]FIG. 2 is a perspective view of the ladder cap of the present invention;
[0011] [0011]FIG. 3 is a cross-sectional view of the ladder taken along the plane parallel to the front face of the ladder cap;
[0012] [0012]FIG. 4 is a cross-sectional view of the ladder taken along the plane parallel to the side face of the ladder cap; and
[0013] [0013]FIG. 5 is an end view of the ladder cap, looking directly into the open end of the ladder cap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Referring to FIG. 1, the present invention is directed to a protective ladder cap 10 that is adapted to fit on a ladder 12 . The ladder, as is well known, typically includes two side rails 14 and a plurality of rungs 16 (only one shown) that are spaced apart to provide steps for the user. The ladder cap 10 is sized to fit over the ends of the side rails 14 to protect the surface upon which the ladder is resting.
[0015] As shown in FIG. 2, the protective ladder cap 10 comprises a cap 18 that has an open end 20 and a closed end 22 . The open end 20 is sized to fit over the end of the side rails. The opening is defined by the length from point 24 to point 26 , which is preferably about 3.5 inches and the length from point 28 to point 30 , which is preferably about 1.25 inches. The dimensions are sized to allow the ladder cap 10 to be easily slid over the ends of the side rails 14 . Referring to FIGS. 3 and 4, the inner surface 32 of the closed end 22 typically abuts against the ends of the side rails when the ladder cap is pushed onto the ladder side rails 14 . The cap 18 includes two wide sidewalls 34 and two narrow sidewalls 36 , which together with the top or closed end 22 form the cap 18 .
[0016] As shown best in FIG. 3, the ladder cap 10 includes two opposed side detents 38 that protrude inwardly to engage the side rails. From the detents 38 , the two wide sidewalls extend outwardly to the closed end 22 at approximately six degrees and the two narrow sidewalls extend outwardly to the closed end 22 at approximately fourteen degrees (i.e., both walls are angled outwardly slightly). The total height of the ladder cap 10 from the open end 20 to the closed end 22 is approximately 5.5 inches. The total height from the open end 20 to the middle of the detents 38 is approximately 2 inches.
[0017] The two wide sidewalls 34 of the ladder cap 10 have internal wide faces 40 and the two narrow sidewalls have internal narrow faces 42 . In the preferred embodiment, the ladder cap 10 includes a plurality of elongated internal wide face ribs 43 on the internal wide faces 40 , as shown in FIGS. 3 and 5. Referring to FIG. 4, the length of each wide face rib 43 is approximately 3 inches, and the height tapers from point 44 to a height of approximately 0.094 inches at point 46 . The taper from point 44 to point 48 is less than the taper from point 48 to point 50 . At point 48 , the height of the rib is approximately 0.219 inches and at point 50 the height of the rib is approximately 0.344 inches. The height at point 51 is approximately 0.438 inches. The internal wide ribs 43 preferably include a height of at least 0.250 inches and the rib is preferably tapered from a lower height of around zero inches to the maximum height, as shown in FIG. 4 at point 51 . Nonetheless, it is appreciated that the lower height could be more than zero. The lower the height, however, the easier to facilitate a smooth engagement by the end of the ladder rail onto the surface of the internal rib. It should also be understood that the terms “narrow” and “wide” as used herein are used simply as descriptive terms to distinguish between the various sides; the terms should not be construed to be limited to a particular dimension or size.
[0018] The wide face ribs 43 also include an indent portion 52 in the preferred embodiment. The indent portion together with the closed end 22 forms a u-shaped channel. The depth from point 51 to the bottom 54 of the indent portion 52 is approximately 0.344 inches. The width of each wide face rib 43 is approximately 0.100 inches and the distance between each rib is approximately 0.210 inches. As shown in FIG. 5, wide face ribs 43 extend inwardly beyond the open end 20 such that when the ladder cap 10 is slid on the end of a side rail 14 through open end 20 , the side rail 14 engages the tapered internal wide face ribs 43 . If the ladder cap 10 is pushed onto the side rail 14 sufficiently, the side rail lodges into the indent portion 52 , further holding the ladder cap 10 on the side rail.
[0019] In the preferred embodiment, the ladder cap 10 also has narrow face ribs 60 on the internal narrow faces 42 , as shown in FIGS. 3 and 5. The narrow face ribs 60 are approximately the same length as the wide face ribs 43 . The rib height tapers from point 62 to a height of approximately 0.438 inches at point 64 to a height of approximately 0.750 inches at point 66 . The width of each narrow face rib 43 is approximately 0.100 inches and the distance between each rib is approximately 0.210 inches.
[0020] It should be understood that the dimensions are only illustrative. One skilled in the art can readily appreciate how to alter the dimensions provided without departing from the spirit and scope of the invention. The same is true with respect to the number of internal ribs. In fact, the present invention would work, although not preferably, with only one thicker internal rib that engages the side rail when it is inserted into the ladder cap 10 . Also, the product will perform well with ribs on only the internal wide faces 40 and will work adequately if the ribs are located only on the side faces 42 . By placing ribs on opposed faces, the ladder cap 10 slides over the side rail 14 more evenly and increases the surface area of frictional engagement. In the preferred embodiment, the ladder cap 10 includes at least 5 internal wide face ribs on each wide face 40 and at least two narrow face ribs.
[0021] In use, the ladder cap 10 is slid over the end of a side rail 14 through open end 20 . The side rail engages the internal ribs 43 and 60 . To the extent the ladder cap 10 is slid over a side rail 14 all the way, the side rail should become lodged in the detents 38 , further securing the ladder cap 10 to the side rail. The wide sides 34 and the narrow sides 36 that extent upwardly beyond the detents 38 to form the closed end 22 are approximately 0.250 inches thick.
[0022] The ladder cap is preferably made out of a PVC plastic that is a dielectric material. In the preferred embodiment, the material is plastisol.
[0023] While a preferred protective ladder cap has been described in detail, various modifications, alterations, and changes may be made without departing from the spirit and scope of the ladder cap according to the present invention as defined in the appended claims. | A protective ladder cap for fitting over the end of a rail of a ladder is provided. The cap has an open end for fitting over the rail and a closed end. The ladder cap has tapered internal ribs for engaging the end of a side rail of a ladder. The ladder caps prevent the ladder side rails from damaging the surface upon which the ladder leans when in use. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to forming textile fabrics with selectively placed interlocking high tensile modular filaments to produce garments and articles having enhanced performance characteristics. More particularly, the invention relates to protective work garments. The invention also relates to a method of producing a unilayer textile fabric where high tensile modular filaments are knitted into pre-selected locations on the textile fabric and the process is controlled by a computer.
2. Brief Description of the Prior Art
The prior art has provided fabric of specific constructive design to overcome particular hazards encountered on the work environment. Generally in such construction, the patents disclose composite requiring layers of high tensile modular filaments which may be further treated by dipping to form a protective fiber or by heat treatment. Such is the case in providing cut resistant fabric for gloves for use by metal working glass handlers, meat cutters, and medical personnel. Each requires protection from a different hazard. The metal workers and glass handlers typically do not need protection from fluids. On the other hand, meat cutters and medical personnel do need this fluid protection to prevent bacterial or viral infection.
U.S. Pat. No. 4,004,295 discloses a glove constructed of yarn of metal wire and a non-metalic fiber such as an aramide fiber as protection from knife cuts.
U.S. Pat. No. 4,651,514 relates to a yarn composed of a monofilament nylon core that is wrapped with at least one strand of aramide fiber and a strand of nylon fiber. This yarn is electrically nonconductive.
Other special fabrics are designed for firefighters, foundry workers, and personnel in the chemical and related industries. Again, additional protection beyond the cut and puncture resistance is required. Generally, this again involves protecting the skin from hazardous liquid chemicals. These include solvents, paints, varnishes, glues, cleaning agents, degreasing agents, drilling fluids, inter alia.
U.S. Pat. Nos. 4,479,368 and 4,608,642 which are herein incorporated by reference disclose programmable knitting machines which may be used in preparing the fabrics of the invention.
U.S. Pat. No. 4,302,851 to Adair discloses a heat resistant protective hand covering in which a wool knit liner is enclosed within an outer layer of woven KEVLAR® aromatic polyamide fiber material with layers of aluminum foil and flexible fiberglass sandwiched there between. A pleated pad of flexible material woven from fiberglass yarns.
U.S. Pat. No. 4,433,479 to Sidman et al., relates to a heat resistant glove having first and second shells formed of temperature-resistant aromatic polyamide fibers such as KEVLAR® with the first shell section being made of a twill weave fabric and the second shell being made of a knitted fabric. A liner is formed of two sections, both are made of a felt fabric of temperature resistant aromatic polyamide fiber with the section forming the palm being provided with a flame resistant elastomeric coating.
U.S. Pat. No. 5,965,223 to Andrews et al, which is herein incorporated by reference discloses a composite layered protective fabric having an outer primary layer of an abrasive material and an inner layer of a cut resistant material positioned below the outer layer.
In each case the prior art patents discussed above requires a plurality of layers to achieve the protection desired. Usually each layer being fabricated of a uniform composite structure. Thus the weight of the fabric is in increased and flexibility and comfort level of the wearer of the garment produced decreased. Furthermore, the extensive use of high performance filaments makes the articles of manufacture more expensive.
Therefore, there exists a need for a flexible and comfortable textile performance protect fabric that is less expensive, more efficient to fabricate, reduces the amount of high performance filaments yet provides the necessary protective characteristics.
SUMMARY OF THE INVENTION
In accordance with the present invention a flexible unilayer fabric is produced in which the interlocking or intertwining of at least one dissimilar filament into pre-selected pattern at definite locations or regions of a base fabric by essentially conventional textile manipulating techniques controlled by a computer. The base fabric is formed from natural material or synthetic organic polymers that have a tensile modulus of about 3,000 kg/mm 2 or less. The performance filaments usable in the present invention have a high tensile modulus of elasticity of about 5,000 kg/mm 2 or more. The high tensile modulus filaments used may vary widely and include inorganic and organic filaments depending on the functional use. However, these high performance materials are very expensive and reducing the amounts without sacrificing performance is accomplished by the present invention.
For comfort and economic reasons the base fabric is manufactured preferably from a less expensive natural fiber such as cotton. As mentioned above type of high tensile modulus filament to be used is predicated on improving the effectiveness of the fabric for an intended function. For example, if garments are expected to provide protection to the wearer from hazards such as abrasions, cuts and punctures, a cut resistant filament is knittingly secured into the base fabric by a computer controlled pattern device. The encoded pattern information (design and location data) will direct the manipulation of the needles to interlock the filaments, for example, only in the finger and thumb stalls and in the palm region of the glove. Preferably the interlocking step is done by knitting. The high tensile modulus filaments are selected from the group consisting of aramides extended chain polyethylene, extended chain polypropylene, liquid crystal polyester, polyolefins, polyesters, polyamides, carbon fibers, metal fibers, fiberglass, and mixtures thereof.
The invention provides a method of manufacturing a unilayer flexible performance textile fabric having at least one high performance filament interlocked or intertwined within the base fabric to enhance an intended function. The first step involves manipulating the performance filament using substantially conventional textile fabric forming technology such as stitching to form a base fabric. The next step also follows conventional techniques such as by knitting the high modulus filament into the base fabric wherein the placement and design of the pattern of the high modulus filament is controlled by the pattern data supplied to a microprocessor to which the manipulations of the knitting needles are responsive providing the pattern programmed in the same single layer as the base fabric
It is the primary object of the invention to provide a unilayer fabric that enhances the performance of an intended function, yet reduces the weight of the apparel or article of manufacture with single layer construction.
Another object of the present invention is to provide a fabric containing high tensile modulus filaments in pre-selected locations within the fabric.
A further object of the invention is to provide a large variety of apparel and articles fabricated from the fabric of the invention.
A still further object of the present invention is to provide performance apparel used for protection against numerous potential hazards.
Yet another object of the present invention is to maximize the effectiveness of expensive high performance material.
Still another object of the present invention relates to articles of manufacture fabricated totally or in part a glove from fabric of this invention.
Another object of the present invention is to provide a glove construction of a unilayer fabric with high tensile modular filaments knitted into the base fabric conforming to the pattern and location programmed and controlled by a computer to form “islands of reinforcement” in the finger, thumb and palm regions against sharp objects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a knit glove formed by the method of the invention;
FIG. 2A shows a prior art method of chain looping two different fibers together in a single layer.
FIG. 2B illustrates the prior art double layer method of chain linking two different fibers.
FIG. 3 shows a flow diagram of the process of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 there is provided a fabric in the form of a knit glove with an elastic band 13 and having a substantial area of cotton and two areas of a high modulus synthetic fiber 12 such as KEVLAR®. Both the cotton fibers 11 and the synthetic fibers are single layered. The prior art method to provide a reinforcement has generally been to over knit an area so as to form a double layer.
FIG. 2A illustrates a prior art method of incorporating a high modulus fiber 14 to form a single layer fabric by primarily alternating the looping of a synthetic fiber onto a natural fiber 15 .
FIG. 2B illustrates the prior art method of forming fabrics with a layer of a double layer natural fiber 15 that is looped with a high modulus fiber 14 .
FIG. 3 shows a flow diagram of the composite controlled process used in the process wherein a microprocessor 20 receives a program in the data input unit 21 . The microprocessor then signals the function selector 23 to decide on the type of weave, namely, knitting, weaving, or stitching depending upon the location. With the desired information there is a selection of needles by the needle selection unit 24 . The operation is continuous by storing the process in the memory storage unit 22 .
The product of the invention is made using chain stitches. The machine picks up the programmed material carrier and at the same time preselected needles raise up to knit the material. Then this material is dropped off and another material carrier is picked up which then knits this material in a preselected location. Using this process one is able to put material in any location on the product.
The present invention in its broadest aspect is a flexible unilayer textile performance fabric comprising a base fabric formed from a first fiber having the design of a desired pattern formed therein by intertwining or interlocking in the same layer at least one dissimilar performance fiber which can be manipulated in accordance with conventional textile fabric manufacturing process but wherein such manipulation is computer controlled. A programmed computer encodes the location(s) and the design of the desired pattern. After such data is entered, this enables the manipulation processes to place such designs in designated locations. This effectively maximizes the benefits of the expensive high performance material while reducing the amount of material needed. For example, if abrasion resistance is needed in an anti-wear garment only those areas requiring this added performance, i.e., elbows and knees would have the performance filaments to provide the desired characteristics.
Broadly, a method of manufacture of the unilayer flexible performance textile fiber comprises the steps of:
(a) manipulating a first fiber in a conventional manner to form a base textile fabric in a single layer; and
(b) manipulating at least one dissimilar performance fiber into the base textile fabric wherein this step of manipulating is computer controlled to produce a predetermined design for a pattern at a pre-selected location within the base textile fabric to form a performance fabric having enhanced performance function.
The first manipulative step (step (a)) involves a stitching operation which is performed by a knitting, sewing, or weaving machine to form a base textile fabric having a mesh or web configuration. The base is then downloaded into a knitting machine.
The type of stitching in the first manipulative step may vary widely. Stitching and sewing methods such as chain stitching, lock stitching and the like are illustrative of the type of stitching for use in this invention. The nature of the stitching fiber or thread will also vary widely and any type of fiber can be used depending on the garment and its use.
More specifically in step (b) the manipulation of the dissimilar performance fiber into the base textile fabric is conducted on a programmed knitting machine. The programming means comprises a microprocessor connected electronically to a programming matrix that controls a fiber carrier while simultaneously activating a needle selection means responsive to an output signed from the microprocessor and then to a pre-selected needle which knits the performance fiber into the web of the base fabric. This fiber carrier is released and in response sends a corresponding impulse to the microprocessor consistent with the input of the pattern and location data; another fiber carrier carrying another performance fiber supplies the fiber to the pre-selected needle which knits the filament into the proper location in the web of the base fabric. This sequence is repeated for each course in the base fabric in a sequential order of knitting. Thus, the fibers can be knitted in any location within the base fabric.
The invented fabric can be produced on essentially conventional textile fiber manufacturing equipment to produce such textile mechanical manipulative functions of sewing, knitting or weaving that are capable of producing the interlocking or intertwining steps of at least one dissimilar performance fibers into the base fabric and where this equipment is modified to effect the computer controlled processes described.
Several advantages flow from this arrangement. The design of a pattern and the textile mechanical manipulation steps or steps may be places into coding matrix electrically connected to the microprocessor unit. This input data may be stored as electrical data on any desired medium, such as a disc or tape. Once this data has been entered, the manipulative steps, i.e. knitting, can take place normally without any necessity to stop the machine or in general terms where to locate the design on the base fabric and where the pattern should begin and end. Units of pattern information so stored are read in sequential order of knitting and are translated into pattern data for needle selection in each knitting course and/or control data for controlling knitting, transfer, rocking and like operations in each knitting course.
The following definitions are supplied in order to more clearly point out the present invention and to avoid ambiguity.
The term “fiber” is meant any thread, filament or the like, alone or in groups of multifilaments, continuous running lengths or short lengths such as staple. Fiber is defined as an elongated body, the length dimensions of which is much greater than the dimensions of width and thickness. Accordingly, the term fiber, as used herein includes a monofilament elongated body, a multifilamented elongated body, and the like having regular or irregular cross sections. The term fibers includes a plurality of any one or a combination of the above.
The cross section of fibers for use in this invention may vary widely. Useful fibers may have a circular cross section oblong cross section or irregular or regular multi-lobal cross section having one or more regular or irregular lobes projecting from the linear or longitudinal axis of the fibers. In the particularly preferred embodiments of the invention, the fibers are of substantially circular or oblong cross section and in the most preferred embodiment are of circular or substantially circular cross section.
In this disclosure the terms “fiber” and “filament” are used interchangeably. The term “yarn” is meant any continuous running length of fibers, which may be wrapped with similar or dissimilar fibers, suitable for further processing into fabric by braiding, weaving, fusion bonding, tufting, knitting or the like, having a denier less than 10,000.
The term “strand” is meant either a running length of multifilament end or a monofilament end of continuous fiber or spun staple fibers, preferably untwisted having a denier of less than 2000.
The term “performance fiber” is meant any fiber or filament having a high tensile modular of elasticity of about 5,000 kg/mm 2 or more that provides an enhanced performance function, such as in cut resistance, abrasion resistance, heat resistance or the like.
In general the specific filament or fiber combination is employed in any particular situation will depend to a large intent to the functional use of the apparel or outside. In the present invention along with enhancing the performance characteristics of the garment or article, the single layer construction reduces the weight and increases the flexibility and comfort factor. Furthermore, since the performance fiber can be specifically located anywhere on the fabric the amount of high performance fiber along with the expense can be reduced.
The type of fibers used in the fabrication of the present unilayer flexible performance textile fabric include organic polymer and inorganic fibers.
Preferably, filaments having a high tensile modulus of elasticity of 5,000 kg/mm 2 or more are usable for the performance fibers which are knitted into the base fabric. Illustrative of useful organic fibers having a high tensile modulus are those selected from the group consisting of aramid fibers, liquid crystal, copolyester fibers, nylon fibers, polyacrylonitrile fibers, polyester fibers, high modular weight polyvinylalcohol fibers and ultra high modular weight polyolefin fibers and mixtures thereof.
High modular weight polyethylene and polypropylene fibers are polyolefin fibers which may be used as performance fibers in preferred embodiments. In the use of polyethylene, suitable fibers are those which have a molecular weight of at least 150,000, preferably at least one million, and more preferably between two and five million. Such extended-chain polyethylene (EC PE) fibers are a high tensile material which are inherently resistant, as well as, being abrasion resistant and flexible providing a superior cut resistant yarn especially for protective gloves. SPECTRA® is a tradename of an ultra high molecular weight extended-chain polyethylene that is marketed.
Similarly, high oriented polypropylene fibers of molecular weight at least of 20,000 preferably at least one million, and more preferably at least two million may be used. Such high molecular weight polypropylene may be formed into reasonably well oriented fibers by techniques prescribed in U.S. Pat. No. 4,551,293 which is herein incorporated by reference. The particularly preferred ranges for the above-described parameters can advantageously provide improved performance in the final article and employed as a performance fiber.
High molecular weight polyvinyl alcohol fibers having a high tensile are described in U.S. Pat. No. 4,440,711 which is herein incorporated by reference. In the case of polyvinyl alcohol (PV—OH), PV—OH fibers having a weight average molecular weight of at least 200,000 may be used. Particularly useful PV—OH fibers should have a tensile modulus of at least 5,000 kg/mm 2 or more. Most preferred fibers are poly-p-phenylene terephthalate KEVLAR® filaments marketed under the tradename KEVLAR® and poly-m-phenylene terphthalate marketed under the tradename NOMEX® each by E. I. DuPont de Nemours &Co., Inc., Wilmington, Del. Each such aramid fiber has strong, high temperature resistant, cut resistant, puncture, and abrasion resistant properties. Most preferred are para-aramide fibers having a tensile modulus of elasticity of about 7,100 kg/mm 2 .
Another high tensile fiber useful in certain applications of this invention is formed from polybenzimidazole polymers available from Celanese Corporation, Chatham N.J., under the tradename P.B.I.® fibers.
Polyacrylonitrite (PAN) fibers of a molecular weight of at least 400,000 are suitable. Since fibers are disclosed in U.S. Pat. No. 4,535,027 which is incorporated herein by reference.
Liquid crystal copolyester suitable in this invention are disclosed in U.S. Pat. Nos. 3,975,487 4,118,372 and 4,161,470 all hereby incorporated by reference.
In the case of nylon fibers, suitable fibers include those formed from nylon 6, nylon 10 and the like.
Suitable polyester fibers include polyethylene terephthalate.
Illustrative of useful inorganic fibers having a high tensile modulus are those selected from the group consisting of S-glass fibers, E-glass fibers, steel filaments, carbon fibers, boron fibers, aluminum fibers, zirconic-silica fibers, aluminum-silica fibers and mixtures thereof. Preferred are glass fibers having a tensile modulus of elasticity of about 7,000 kg/mm 2 . Preferred steel filaments have a tensile modulus of elasticity of about 20,000 kg/mm 2 .
Low tensile modulus fibers having a tensile modulus of 3,000 kg/mm 2 or less are effective for importing the high degree of flexibility to the unilayer base fabric and the susequent garment manufactured therefrom.
The synthetic fibers are preferably selected from the group consisting of viscose rayon fibers, aliphatic polyamide fibers, polyacrylic fibers, polyester fibers, water insoluble modified polyvinyl alcohol fibers and mixtures thereof. Most preferred fibers for the base fabric are natural fibers such as cotton and wool. Both fibers have the flexibility characteristics desired and provide a proper comfort level to wearer. For these reasons they can be positions proximate to wearers skin.
Fibers having a relatively low tensile modulus can be used independently or together with ordinary relatively low tensile modulus fibers, without difficulty, in the method of this invention.
The performance fiber can also be a blend of mixed fibers, i.e. a lower strength fiber with the high strength fiber. Likewise, the performance fiber could be a composite fiber wherein the matrix is a softer material impregnated with a hard material such as carbon or glass fibers.
In addition, the fibers can be composed of fibers with anti-microbial additives or otherwise impregnated with an anti-microbial agent.
Even one skilled in the art might assume that the hard fibrous materials used as part of this invention would be very brittle and therefore of limited use in protective garments where flexibility and comfort are of major concern. The glass or steel filaments which would normally be used in this invention are extremely small in diameter. If a larger diameter is required, an impregnated fiber, described above, can be used. As a result, these hard materials are still very flexible and can be bent around a very small radius without breaking. In this embodiment it is preferred that the hard fibrous material is located within the matrix of the yarn. By placing the hard material in the matrix of the yarn, the hard material is exposed to the least stress during bending of the yarn. Furthermore, by placing the hard material within the matrix, the outer portion of flexible material helps to protect the more brittle, harder component.
In many cases, it will be preferred that the hard fibrous material be coated with a continuous layer of elastic material. This coating has several functions. For example, if the hard material is a multifilament fiber, the coating holds the fiber bundle together and helps protect it from stresses that develop during the manufacturing process. Furthermore, the coating may provide a physical or chemical barrier for the hard material. Finally, if the hard material is broken during use, the coating will trap the material so that it will not leave the fibrous structure.
It is to be understood that the present invention provides for a multiplicity of embodiments by using any of a large number of protective materials in combination to form a composite in a single layered fabric. Consequently, the invented fabric can be made into a large variety of articles and protective apparel used for protection against numerous potential hazards.
EXAMPLE 1
A cut-resistant glove having isolated patterns of high tensile modulus fibers in critical locations is prepared.
The method of manufacture involves first chain-stitching a 100 percent cotton fiber on a programmed flat knitting machine, such as describer in U.S. Pat. No. 4,479,368, to form a base fabric in a mesh and web construction having a weight of about 4 to 7 oz/sq yd. After the base fabric is formed it is downloaded into a knitting machine into which the design of the isolated patterns have been programmed. KEVLAR® having a denier of the individual filament of 1.5 and a tensile modulus of 5900 kg/mm 2 is knitted into the same layer as the mesh and web of the base fabric. The movement of the knitting needle with respect to the palm portion and the finger and thumb stalls is controlled by a computer.
To complete the assembly of the glove, the edges of the back and palm portions, along with the finger and thumb stalls are secured by sewing aromatic polyamide fibers on a conventional industrial machine.
The glove has the desired qualities of high gripability, cut-resistance, puncture resistance, abrasion resistance, flexibility and softness.
It should be apparent to those skilled in the art, that other embodiments, improvements, details and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims construed in accordance with the patent statutes, including the doctrine of equivalents. | The present invention relates to a unilayer flexible performance fabric which may be fabricated into apparel and articles having high performance fibers, such as high tensile modulus fibers positioned within a base fabric in at least one preselected location only where required to import performance characteristics which are equal to or exceed the specifications for the garment. For example, if cut resistance is a requirement, performance fibers which provide such protection from this hazard would be used. Likewise, if abrasion resistance is intended for an apparel such as coveralls, only the knees and elbows would require the performance fiber. Thus, reducing the amount of expensive fibers normally used. The invented fabric is manufacturede in a method in which the placement of the fabric in preselected locations is computer controlled. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Does not apply.
FIELD OF THE INVENTION
[0002] The invention relates to secure erasure of sensitive or private data from storage media.
BACKGROUND OF THE INVENTION
[0003] Many photocopiers, printers, and other reproduction and printing devices now include non-volatile memory (NVM), such as magnetic and optical storage media and including removable disk systems, hard drives, and other storage media systems allowing the device and/or a user to store a job the device uses or is directed to use the stored job. In high security areas (e.g., military installations), there is often a requirement that all jobs that stored on NVM of a device shall be inaccessible once the job is completed. Additionally, users in lower security area often wish to erase data they would like to keep private or confidential for various reasons.
[0004] The currently prevalent method of deleting a file is to delete the pointers and/or directory information that allows the device to locate the data; the document images/data files themselves are still resident in the NVM. This method usually does not meet the requirement that the job data shall be erased from the NVM once the job is complete. Current workarounds include: (1) removal of the NVM from the device and locked up at night, or (2) prohibiting NVM installation in the first place.
[0005] Lately, secure erase systems that overwrite the data with patterns of 1s, 0s, or random combinations thereof have come into use to meet erasure requirements. However, government agencies and other customers have different requirements as to how many times one can overwrite the appropriate portions of NVM once a job or task is completed, which can lead to difficulties in product design and implementation.
SUMMARY OF THE INVENTION
[0006] Embodiments of the invention allow a user or a system administrator (SA) to program a device to overwrite the region of NVM in which the data file associated with a print, scan, fax, copy, or other job resides. In embodiments, the data file is overwritten more than once, such as from 2 to about 50 time, with the exact number of overwrites being determined according to a stored default value or a user-input value. Further, in embodiments, the data file is overwritten with a different pattern on each overwrite according to a stored default value or a user-input value. For example, if a user has just printed something stored on a floppy disk, the user can erase it securely with a sequence of patterns of choice. Instead of trying to settle on a single algorithm (e.g., overwrite 3 times, first time with 1s, the second time with 0s, the third time with a random pattern), this allows overwriting “n” times with a set of patterns that can be downloaded to the device.
[0007] Thus, the device, medium, and process of the present invention can have, in various embodiments, three parameters:
[0008] 1. A set of patterns with which the portion of the hard drive that is to be erased will be overwritten. This could be a table of patterns that will be used to overwrite the disk. In embodiments, the table of patterns can be generated in a manner allowing a customer/SA to preprogram the patterns so that the patterns are in a sequence that satisfies an installation's particular security requirements. In pseudo code, this looks like:
[0009] PatternTable (N)←Pattern 1 , Pattern 2 , Pattern 3 , . . . PatternN;
[0010] 2. A site settable value that allows the customer/SA to program how many patterns with which to overwrite the portion of the hard drive that should be overwritten. The site settable value can be, for example, between 1 and about N (N is the number of patterns in PatternTable). In various embodiments, for example, NumPatternToUse is this site settable value.
[0011] 3. A site settable value that allows the customer/SA to program how many times the entire set of patterns should be run. It can have any positive value. In various embodiments, NumberOfTimesToCycle can be this value.
[0012] The algorithm then uses, in various embodiments, the patterns and the number of overwrites to overwrite the portion of the disk N times. An example of a routine that can be used in embodiments of the invention employing a value like NumberOfTimesToCycle is the pseudocode expression:
[0013] For count←1 to NumPatternToUse Do
[0014] Overwrite region of storage media that stored the data file with PatternTable(count);
[0015] This allows for a flexible, programmable sequence of overwrites that should satisfy any overwrite requirement by any customer. Embodiments using a value like NumberOfTimesToCycle can use a routine such as, for example, that expressed by the pseudocode expression:
[0016] For NumberOfOverwriteCycle←1 to NumberOfTimesToCycle Do
[0017] For count←1 to NumPatternToUse Do
[0018] Overwrite region of storage media that stored the data file with PatternTable(count);
[0019] Embodiments of the invention employ a user interface (UI) or client activated erase trigger to automatically place the digital copier or printer into, for example, an Image Disk Erasing Routine, where an Image Disk is a storage media used by the device to store data files including scanned images of documents and/or print job data and the like. An example of such an Erasing Routine is a routine that executes three complete erasures with a check to ensure the data is completely erased; per industry or security approved processes. The Erasing Routine removes or destroys any residual data files including documents, images, and the like, on the Image or ESS Disks. In embodiments, a customer selectable UI/client button with confirmation that the process was completed could activate this routine. During this erasing feature, the system would be offline.
[0020] Thus, a feature of the invention to provide a storage medium security erase system comprising an erase trigger that tells a drive sector analyzer to retrieve data file location information from a CPU and send the location information to a secure storage medium eraser that overwrites the data file according to a predetermined secure erase method, the eraser using a type of overwrite pattern and a number of overwrites determined by an erase pattern determiner according to predetermined criteria and/or user input.
[0021] An additional feature of the invention is to apply a method of securely erasing a data file by a providing an erase trigger, determining a location of the data file on the storage medium, overwriting the data file according to a predetermined secure erase method, and determining at least a number of times to overwrite the data file in response to the erase trigger and according to predetermined criteria.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a perspective view of a digital printing and/or reproducing device that can use embodiments of the invention;
[0023] [0023]FIG. 2 is a close-up perspective view of a removable storage media drive of the device shown in FIG. 1;
[0024] [0024]FIGS. 3A and 3B are elevational views of a display panel of the device of FIG. 1 showing a graphical user interface in which a user can select parameters of embodiments of the invention; and
[0025] [0025]FIG. 4 is a schematic of a graphical user interface dialog box of a driver that can be implemented on a personal computer to control the device shown in FIG. 1, the dialog box allowing selection of parameters of embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] With reference to the accompanying FIGS., various embodiments of the invention include a device 1 , such as a scanner, printer, photocopier, or other device, having a non-volatile memory (NVM) 2 , such as a magnetic or optical storage medium, to which the device 1 can store data 3 and/or from which the device can read data 3 stored in a data file 4 . In embodiments, the device 1 can use the data 3 to produce output, such as paper hard copy of a word processing document or the like.
[0027] Various embodiments of the invention use a CPU 5 of the device 1 in which elements of the invention reside and that provides and executes various processes of the invention. For example, the CPU 5 can provide or respond to an erase trigger 6 . The erase trigger 6 in embodiments of the invention can be a physical button on the device, a virtual button on, for example, an LCD of the device, or an instruction sent to the device as part of the data file 4 used to generate output from client software, such as a driver interface 7 on a remote computer. The CPU 5 stores the data file 4 in the NVM 2 , which can be a fixed or removable storage medium, and keeps track of the data file 4 so that, when the erase trigger 6 is set, the erasure process can determine a location 8 of the data file on the NVM 2 . The erasure process then overwrites the data file 4 according to a predetermined secure erase method; in embodiments of the invention, the secure erase method can include overwriting the data file 4 a particular number of times 9 , using a particular pattern 10 to overwrite the data file 4 (such as all 1s, all 0s, etc.), and/or cycling the overwrite pattern on each iteration of the overwrite process 11 . Other iteration and pattern variations can also be used.
[0028] To determine at least a number of times to overwrite the data file 4 , the erasure process can check or respond to, for example, the erase trigger 6 , which can include this information. Alternatively, in embodiments where the invention is implemented in a photocopier or the like, the user can be prompted to enter the number of times 9 and/or pattern(s) 10 to use to overwrite the data file 4 . In embodiments in which the erase trigger 6 is provided from a driver interface 7 , the user can provide the number of times 9 and/or pattern(s) 10 to use to overwrite the data file 4 when creating the job in the first place. Other user interfaces could also be employed, such as a web- or markup-language-based interface usable over a network and other interfaces, to provide the erase trigger 6 and the various parameters a user might be allowed to enter.
[0029] In embodiments allowing user selection of the various parameters, the CPU 5 can provide one or more graphical user interface (GUI) element(s) 13 in communication with or acting as the erase trigger 6 . The CPU 5 can accept the user-selected parameter(s) from the GUI element(s) 13 with which to overwrite the data file. For example, the GUI element can be a virtual button or keypad displayed on a pressure-sensitive display of the device, such as that shown in FIGS. 3A and 3B. In embodiments, the GUI element(s) 13 can be part of a driver interface similar to that shown in FIG. 4.
[0030] In addition to user-selectable criteria, embodiments of the invention can allow a system administrator (SA) to program the device 1 to overwrite the data file 4 according to predetermined criteria, such as a stored number of overwrites 9 and/or sequence of patterns 10 of choice. Rather than trying to settle on a single algorithm (e.g., overwrite 3 times, first time with 1s, the second time with 0s, the third time with a random pattern) for all customers, this allows selection by the SA during setup or reconfiguration of the device 1 . Further, embodiments of the invention can allow the SA to program a timer that will automatically delete all data files after a specified period has elapsed.
[0031] Where more than one pattern 10 is available, a set of patterns 12 can be stored in a storage medium 2 in communication with the system. The set of patterns 12 can be stored in a computer memory or another storage medium in, for example, a table, such as a table resembling the pseudocode expression:
[0032] PatternTable (N)←Pattern 1 , Pattern 2 , Pattern 3 , . . . Pattern.
[0033] The invention can then use the set of patterns 12 , the number of times to overwrite 9 , and a pattern selection variable to erase the data file 4 by overwriting. For example, in embodiments of the invention, the user-selected pattern NumPatternToUse to be used and a number of times N to overwrite the data file 4 according to the pseudocode expression:
[0034] For count←1 to NumPatternToUse Do
[0035] Overwrite region of storage media that stored the data file with PatternTable(count);
[0036] [0036]FIGS. 5 and 6 show two flow charts that show how embodiments of the invention might carry out the erasure process. Referring to FIG. 5, an embodiment of the process 11 using predetermined patterns from a pattern table, as well as a predetermined number of patterns to use (expressed by the variable NumPatternsToUse) is shown in flow chart 100 . The erase trigger 6 is represented in the beginning block 101 of the flow chart 100 and an initial step is to set the counter NumberOfOverwrites to 0 as shown in block 102 . Next, the first overwrite pattern is loaded from the pattern table, as seen in block 103 . The data file 4 is overwritten using the loaded pattern as illustrated in block 104 , and the NumberOfOverwrites is incremented as seen in block 105 . The counter is compared to the number of patterns to use as shown in block 106 . If the counter value is less than the number of patterns to use, then the next pattern is loaded as seen in block 107 , and the steps shown in blocks 104 - 107 continue to be executed until the counter value is no longer less than the number of patterns to use, at which point the overwrite is complete, as expressed in block 108 .
[0037] Referring to FIG. 6, an embodiment of the invention 11 using predetermined patterns from a pattern table, as well as a predetermined number of patterns to use (expressed by the variable NumPatternsToUse) is shown in flow chart 200 with the added feature of a number of overwrite cycles to be completed. The erase trigger 6 is represented in the beginning block 201 of the flow chart 200 and an initial step is to set the counter NumberOfOverwriteCycles to 0 as shown in block 202 , then to set the counter NumberOfOverwrites to 0 as shown in block 203 . Next, the first overwrite pattern is loaded from the pattern table, as seen in block 204 . The data file 4 is overwritten using the loaded pattern as illustrated in block 205 , and the NumberOfOverwrites is incremented as seen in block 206 . The counter NumberOfOverwrites is compared to the number of patterns to use as shown in block 207 . If the counter value is less than the number of patterns to use, then the next pattern is loaded as seen in block 208 , and the steps shown in blocks 205 - 208 continue to be executed until the counter NumberOfOverwrites has a value that is no longer less than the number of patterns to use, at which point the particular overwrite is complete and the counter NumberOfOverwriteCycles incremented, as expressed in block 209 . As shown in block 210 , the value of the counter NumberOfOverwriteCycles is compared to a predetermined NumberOfTimesToCycle. If this counter value is less than the number of times to cycle, then the counter NumberOfOverwrites is reset, and the steps shown in blocks 203 - 210 continue to be executed until the counter NumberOfTimesToCycle has a value that is no longer less than the number of times to cycle, at which point the particular overwrite is complete as seen in block 211 .
[0038] As should be readily apparent to one of ordinary skill in the art, the preprogrammed values of NumberOfOverwrites and NumberOfTimesToCycle, as well as the preselected patterns, of the particular processes shown in FIGS. 5 and 6 could be user selected values entered into the system using apparatus and methods such as those shown in FIGS. 3 and 4, among others.
[0039] Thus, in installations where customers wish to ensure data security, such as high security areas like military installations, customers can meet the requirement that all printed/copied jobs stored on hard drive(s) or other storage media of such devices be inaccessible once the job has completed without removing the storage medium. In addition, many customers simply want to ensure the privacy of their information and wish to erase print and/or copy jobs from storage media on which the jobs might be stored. The current conventional method of deleting a file (deleting the pointers to the data) can still be done, but the method according to embodiments of the invention ensures that data files themselves no longer reside on the disk and can not be recovered.
[0040] Other modifications of the present invention may occur to those skilled in the art subsequent to a review of the present application, and these modifications, including equivalents thereof, are intended to be included within the scope of the present invention. | A process that ensures the destruction of data files a user wishes to completely erase from a storage medium, such as a hard drive or removable disk. A system administrator can select a quantity of and pattern to be used in overwrites of the data file so that no one can recover the data from the storage medium. In embodiments, a graphical user interface (GUI) can be provided to allow user triggering of and parameter setting for the process. The GUI can be implemented at a device in which the storage medium is a component or can be implemented in a device driver GUI on a personal computer in communication with the device. | 6 |
PRIORITY
[0001] This application claims foreign priority of the German application DE 10248215.2 filed on Oct. 16, 2002.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates to a sealing device which has a conducting element which can be inserted off-center in a through-hole in a housing wall, and which has a sealing body touching both the conducting element and the housing wall.
BACKGROUND OF THE INVENTION
[0003] Sealing devices of this type are used in particular to effect an oil-tight seal on the through-hole for a connector in the wall of a gearbox housing. Because the connectors which pass through the wall of the gearbox housing have fixed connections to electronic circuits on the inside of the housing, the longitudinal axis of the connector does not always coincide with the longitudinal axis of the through-hole. The familiar way of sealing the through-hole in spite of this eccentricity is to provide a very large and soft circumferential seal around the connector, which can largely accommodate the eccentricity between the connector and the housing.
[0004] A disadvantage of this familiar sealing device is the unequal distribution of the sealing force around its perimeter, between the connector and the housing. Furthermore, very high total forces are required to ensure an adequate seal.
[0005] For this reason, connectors have been developed which can be mounted concentrically in the through-hole. However, these require an expensive mechanical compensation mechanism in the mechanical connector system.
SUMMARY OF THE INVENTION
[0006] Starting from this state of the art position, the object underlying the invention is to devise a simply-constructed sealing device with which it is possible to effect a homogeneous seal on eccentric through-holes for a conducting element. A further object underlying the invention is to devise a method of assembling the sealing device.
[0007] These objects can be achieved by a sealing device comprising a conducting element which can be inserted off-center in a through-hole in a housing wall, and which has a sealing body touching both the conducting element and the housing wall, wherein in the region where the sealing body contacts the conducting element and the housing wall, the cross-sectional profile of the housing wall and the conducting element has at least one recess within which the sealing body can be moved in a radial direction.
[0008] The objects can also be achieved by a method for sealing comprising the step of:
[0009] using a sealing device comprising a conducting element which can be inserted off-center in a through-hole in a housing wall, and which has a sealing body touching both the conducting element and the housing wall, wherein in the region where the sealing body contacts the conducting element and the housing wall, the cross-sectional profile of the housing wall and the conducting element has at least one recess within which the sealing body can be moved in a radial direction, to seal an eccentric through-hole for a conducting element, through the housing wall of a gearbox.
[0010] The sealing body may have one axial seal located in the recess and a further radial seal which mates with a surface which bounds the space between the connector body and the housing wall. The sealing body can be fixed by means of a clamping device which applies a force to the sealing body in the axial direction. The recess can be formed in the conducting element. A sealing ring with an internal thread can be screwed onto the conducting element to fix the sealing body. The recess can also be formed in the housing wall. The sealing body can then be fixed by means of an adjusting ring with an external thread. An end stop can be formed on the sealing body in a position which lies within the recess. The sealing body is attached to the conducting element by means of a positive retainer.
[0011] The objects can further be achieved by a method for assembling a sealing device, in which a conducting element and a sealing body are used in a through-hole in a housing wall, wherein the sealing body is first located in the radial direction in at least one recess provided in the contact area in the cross-sectional profile of the housing wall and the conducting element, and is then subject to a force which acts in the axial direction by means of a clamping device which acts on the sealing body in an axial direction.
[0012] The sealing body can be located in a radial direction in a recess formed in the conducting element, and can be subject to a force which acts in an axial direction applied by an adjusting nut which can be screwed onto the conducting element. The sealing body can also be located in a radial direction in a recess formed in the housing wall and can be subject to a force which acts in an axial direction applied by an adjusting ring which can be screwed into the recess.
[0013] With the sealing device, the cross-sectional profile of the housing wall and the conducting element are shaped in such a way that in the area where they touch the sealing body there is at least one recess within which the seal can be moved in a radial direction. With this sealing device, the radial position of the sealing body can be adjusted to the position of the conducting element concerned, and hence the position of the sealing body can be chosen in every case so that the seal is effected with a uniform radial contact force. Consequently, it is only necessary to ensure that the cross-sectional profile of the housing wall and the conducting element have recesses which permit movement of the sealing element in the radial direction. Additional mechanisms, by which for example with the current state of the art the conducting element is aligned with the axis of rotation of the through-hole, are not necessary.
[0014] In a preferred form of embodiment, sealing elements are provided on the sealing body to work in an axial direction in the recess, while the sealing elements of the sealing body which effect a seal in the radial direction are provided in the space between the conducting element and the housing wall. This form of embodiment offers the advantage that the sealing body can be fixed by means of a clamping device which applies a force to the sealing body in an axial direction.
[0015] The recesses provided to allow movement of the sealing body can be either in the conducting element or in the housing wall. In a preferred form of embodiment, the recess required for movement of the sealing body is formed in the conducting element. The clamping device is a clamping ring, with an internal thread, which can be screwed down onto the sealing body to affix it. In this exemplary form of embodiment, no special tools are required to assemble the clamping ring.
[0016] In a derived form of embodiment, the recess to accommodate the radial movement of the sealing body is provided in the housing wall. In this case, a clamping ring with an external thread can be screwed down onto the sealing body to affix it.
[0017] It is expedient if the assembly of the sealing device is effected by first inserting the conducting element and the sealing body into the through-hole. The sealing body is then aligned to correspond with the position of the conducting element in relation to the through-hole, and is fixed by means of the clamping device. This produces a sealing device which is oil-tight and which is also capable of accommodating mechanical loads, due for example to vibration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention is explained below by reference to the examples in the attached drawings. These show:
[0019] [0019]FIG. 1 a cross-section through a first form of embodiment of the sealing device; and
[0020] [0020]FIG. 2 a cross-section through a second form of embodiment of the sealing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] [0021]FIG. 1 shows a housing wall 1 with a through-hole 2 . A connector body 3 which has contacts 4 has been inserted into the through-hole 2 . The connector body 3 can take the form of any required conducting element which is provided to transmit signals. Because the connector body 3 is connected to an electronic component on the inside of the housing wall 1 , it is not always possible to make the longitudinal axis 5 of the connector body 3 coincide with the longitudinal axis 6 of the through-hole 2 . Rather, an offset 7 arises, and this must be compensated by means of a sealing cuff 8 . The sealing cuff 8 has a sealing lip 9 around its outer circumference, which presses against the inner side 10 of the through-hole 2 , and which seals off the through-hole 2 in the radial direction 11 . The sealing cuff 8 is positioned concentrically with the through-hole 2 . The material properties of the sealing cuff 8 are chosen so that in the region of the sealing lip 9 they create a radial sealing effect against the housing wall 1 .
[0022] Engagement ribs 13 are provided on the inner side 12 of the sealing cuff 8 , and these engage in the recesses 14 in the connector body 3 . The radial depth of the engagement ribs 13 and the dimensions of the recesses 14 are chosen so that the sealing cuff 8 is held by the connector body 3 during assembly. In particular, one of the engagement ribs 13 will still project into its associated recess 14 even when a diametrically opposite engagement rib 13 is inserted into the recess 14 up to its limit. The engagement ribs 13 thus serve as a positive retainer.
[0023] The sealing cuff 8 also has a base collar 15 , which engages into a circumferential seal groove 16 in the connector body 3 . In a derived form of embodiment, the seal groove 16 can also be replaced by a shoulder which is open in the upward direction. The base collar 15 of the sealing cuff 8 is provided with another sealing lip 17 , which effects a seal in the axial direction 18 . The base collar 15 of the sealing cuff 8 can be affixed using an adjusting nut 19 , which applies an inward force on the sealing collar 15 in the axial direction 18 . To this end, the adjusting nut 19 has an internal thread 20 , which works in conjunction with an external thread 21 on the connector body 3 . The axial sealing function is effected by the axial force applied by the adjusting nut 19 , by which the base collar 15 is pressed against a mating surface 22 in the seal groove 16 . This axial force can also be applied by a suitable bayonet fastener or some other suitable adjusting arrangement.
[0024] Because the connector body 3 can move within the sealing cuff 8 , any eccentricity of the two parts can be accommodated without stress. The axial seal by the sealing lip 17 only becomes effective when the adjusting nut 19 is tightened up from the outer side of the housing wall 1 . The sealing cuff 8 and the connector body 3 are then rigidly joined together via the sealing lip 17 . Any destructive compression of the axial sealing lip 17 can be prevented by a limiting stop 23 on the sealing cuff. Depending on the compression force applied by the adjusting nut 19 it is even possible that the connector body 3 subsequently remains free to move at any time relative to the sealing cuff 8 . This will be sensible in situations where thermal expansion or vibrations are to be accommodated.
[0025] [0025]FIG. 2 shows another exemplary form of embodiment of the sealing device. With this sealing device, the through-hole 2 is formed in a housing wall 24 , and a connector body 25 extends through the through-hole 2 . Inside the connector body 25 there can be contact structures, which are not shown in FIG. 2.
[0026] With the exemplary form of embodiment shown in FIG. 2, the through-hole 2 is sealed by a sealing collar 26 , comprising a sealing sleeve 27 which extends along the connector body 25 and a sealing disk 28 which spreads radially outwards. On the inner side 29 of the sealing sleeve 27 there is a sealing lip 30 which runs around the connector body 25 , which touches the outer side 31 of the connector body 25 .
[0027] On the outer side of the housing wall 24 there are recesses 32 into which the sealing disk 28 of the sealing collar 26 extends. A sealing lip 33 which is formed on the sealing disk 28 , which presses against a mating surface 34 in the recess 32 , seals off the through-hole 2 in the axial direction 18 . Here, the sealing lip 33 is subject to a force which works in the axial direction, applied by an adjusting ring 35 . This adjusting ring 35 has an external thread 36 , which engages in an internal thread 37 in the recess 32 . Any destructive compression of the sealing lip 33 can be prevented by a limiting stop 38 .
[0028] The sealing lips 9 , 17 , 30 and 33 can be seal inserts or could also be molded on or dispensed seals. Or the sealing cuff 8 or sealing collar 26 itself could also consist of a suitable sealing material, for example hard rubber, so that it effects all the sealing functions. In this situation, care must be take that the sealing cuff 8 and the sealing collar 26 apply the necessary contact force to create the radial sealing effect.
[0029] Using the sealing devices described here, it is possible to effect a uniform seal for eccentric connector through-holes. In this case, the fixing of the connector body 3 or 25 to the electronic components does not need to allow movement. Consequently, the design of the connector body 3 or 25 can be kept simple.
[0030] Even under operational conditions, the connector body 3 or 25 remains moveable relative to the sealing cuff 8 or sealing collar 26 . This allows vibrations or thermal expansions to be accommodated without the sealing device developing leaks.
[0031] The exemplary form of embodiment of the sealing device shown in FIG. 1 can be installed either from the inner side of the housing wall 1 or from the outer side of the housing wall 1 . If the engagement ribs 13 are omitted, it is also possible to assemble the sealing cuff 8 after the connector body 3 has been inserted into the through-hole 2 . | To provide a seal for a conducting element ( 3 ) which is positioned eccentrically in a through-hole ( 2 ) in a housing wall ( 1 ), a proposal is made for a sealing body ( 8 ) which can be moved in a radial direction ( 11 ) and which can be fixed after assembly of the conducting element ( 3 ) by means of a clamping device ( 19 ). | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and useful improvements in pneumatically operated impact drilling tools and more particularly to pneumatic drills which enter the bore hole and are known as downhole drills. In particular, this invention relates to improved pneumatically operated drills which maybe operated at a variety of selected flow rates and pressures of the compressed air or other pneumatic fluid used in operation of the tool.
2. Brief Description of the Prior Art
The most pertinent prior art relating to this invention are the prior patents of applicant and of other inventors assigned to the assignee of this invention.
Rosco U.S. Pat. No. 3,896,886 discloses an air hammer embodying an outer housing structure connectable to rotatable drill pipe string through which compressed air is conducted. A hammer piston reciprocates in the housing structure, compressed air being directed alternately to the upper and lower ends of the piston to effect its reciprocation in the structure, each downward stroke inflicting an impact blow upon the anvil portion of an anvil bit extending upwardly within the lower portion of the housing structure. The flow of air to the upper and lower ends of the hammer piston is controlled by valve passages formed in the piston and a relatively stationary air supply tube which closes the passage to the lower end of the piston when the outer housing structure is lifted by the drill pipe string to allow the bit to hang down from the housing during the circulation of air for flushing cuttings from the bore hole.
Curington U.S. Pat. No. 3,944,003 discloses an air hammer embodying an outer housing structure connectable to a rotatable drill pipe string through which compressed air is conducted. A hammer piston reciprocates in the housing structure, compressed air being directed alternately to the upper and lower ends of the piston to effect its reciprocation in the structure, each downward stroke inflicting an impact blow upon the anvil portion of an anvil bit extending upwardly within the lower portion of the housing structure. The compressed air acts against the piston over the full internal cross-sectional area of the housing structure in delivering its impact blow, such compressed air acting downwardly over at least a portion of the piston area during its entire downward stroke, including its latter portion, during which the power or impacting air is being exhausted from the housing structure.
Curington U.S. Pat. No. 3,958,645 discloses an air hammer embodying an outer housing structure connectable to a rotatable drill pipe string through which compressed air is conducted. A hammer piston reciprocates in the housing structure along flexible inlet and outlet tubes, compressed air being directed alternately to the upper and lower ends of the piston to effect its reciprocation in the structure, each downward stroke inflicting an impact blow upon the anvil portion of an anvil bit extending upwardly within the lower portion of the housing structure. The piston contacts the housing structure at the upper and lower portions of the piston only, so that the piston can deviate upon flexing of the housing structure under load, and not bind in the housing structure, as permitted by the flexible inlet and outlet tubes. Excess compressed air is permitted to bypass through an orifice in the piston itself, to assist in cleaning the bore hole of cuttings and to avoid excess back pressure in the tool above the piston, resulting from the excess air delivered by the air compressor.
The patents described above define and claim features of a commercially available pneumatic downhole hammer, viz. the Model D-2 air hammer, manufactured and sold by the assignee of this invention, Baker Drill, Inc. The Baker Drill Model d-2 air hammer is designed to operate at a low air flow for low air pressures and at a high air flow for high air pressures. It has recently been observed that many drillers desire to use compressed air rigs which operate at high pressure but relatively low volume. As a result, there has been a demand for air hammers which will operate with a low volume of compressed air when run at high pressure.
SUMMARY OF THE INVENTION
This invention relates to an improved penumatically operated drilling tool of the downhole type which is adapted for connnection in a string of drilling pipe and supplied with compressed air or other pneumatic fluid therethrough. The tool includes a housing having an upper sub closing the upper end thereof and adapted for connection to the lower end of the string of drilling pipe. An anvil member is slidably positioned in the lower end of the housing and extends outside the housing, terminating at its lower end at a bit member. The anvil member has a passage way extending longitudinally therethrough. A hammer piston is positioned for reciprocal movement in the housing above the anvil member and is movable to strike the anvil member repeatedly. The hammer piston has a longitudinally extending passageway. The feeder tube is secured to a supporting member on said upper sub and extends slidably into the upper end of the longitudinal passageway of sub hammer piston. An exhaust tube is secured in the anvil member passageway and extends slidably into the lower end said hammer piston passageway. A system of passages and under cuts and valving surfaces define a passageway extending from the upper sub to the upper end of the hammer piston when in an up position and extending to the lower end of the hammer piston when in a down position. Similarly, a system of under cuts and valving surfaces define a passageway extending from the lower end of the hammer piston to the exhaust tube when the hammer piston is in an up position and extending from the upper end of said piston to said exhaust tube when said hammer piston is in a down position. An annular plug member fits on the supporting member for the feeder tube and determines the volume of compressed air or other pneumatic fluid required to operate the hammer piston at any predetermined pressure. The size of the annular plug member is related to the proportions of the feeder tube to determine both the volume of air utilized at a particular pressure and the timing of operation of the hammer piston. The feeder tube and annular plug member are preferably made of a flexible plastic material and are made available in matched sets and are removably positioned on the supporting member in the air hammer so that like sets of different size and proportion may be substituted to permit the operation of the air hammer at any of a variety of air pressures or air flow rates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B together constitute a longitudinal section through an apparatus embodying the invention, with parts in their relative position or drilling and in which the hammer piston has completed delivering an impact blow against the anvil bit, FIG. 1B being a lower continuation of FIG. 1A.
FIGS. 2A and 2B are viewed similar to FIGS. 1A and 1B with the hammer piston approaching tis upper position, FIG. 2B being a lower continuation of FIG. 2A.
FIGS. 3A and 3B are viewed similar to FIGS. 1A and 1B, illustrating the relationship of parts when the air hammer has been elevated from the bottom of the hole with the drill bit in a dropped position, allowing air to be circulated through the apparatus, FIG. 3B being a lower continuation of FIG. 3A.
FIG. 4 is a view in cross-section taken on the line 4--4 of FIG. 2B.
FIG. 5 is a view in cross-section taken on the line 5--5 of FIG. 3B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, an air hammer apparatus 1 is provided which is secured to the lower end of a string of drill pipe 2, by means of which the apparatus is rotated to correspondingly rotate an impact anvil bit 3 used for drilling a bore hole 4, the apparatus delivering repeated impact blows upon the anvil bit by forcing compressed air or other pneumatic fluid down the drill pipe for actuating the apparatus and cleaning the cuttings from the bottom 5 of the hole.
The apparatus is relatively simple, consisting of an elongated housing 10 that includes an upper sub 11 having an upper threaded pin 12 for threaded attachment to the lower end 13 of the string of drill pipe 2, and extends to the drilling rig (not shown) at the top of the bore hole 4. The sub 11 is threadedly secured, as at 110, to the upper portion of an elongate housing section 14, which can be of one piece, the lower end of which is threadedly secured to a lower housing head or drive sub 15, the lower end 16 of housing section 14 bearing against an upwardly facing shoulder 17 formed on drive sub 15.
An elongated anvil portion 18 of the anvil bit 3 is piloted upward within driver sub 15 and lower portion 19 of the housing section 14, the hammer piston 20 being reciprocable in the housing section above anvil 18 to deliver rerepeated impact blows thereagainst. Anvil 18 is preferably formed integral with drill bit portion 21, which has suitable cutting elements 22, e.g. sintered carbide inserts, mounted in its drilling face 23 for impacting against the bottom 5 of bore hole 4, to produce cuttings therein, the cutting elements 22 also acting against the side of bore hole 4 adjacent to its bottom to insure the production of a bore hole of the desired diameter.
During the reciprocation of hammer piston 20 in the housing to deliver impact blows upon anvil bit 18, drill pipe string 2 and housing structure 10 are rotated at a predetermined speed, e.g. 10 to 20 r.p.m., to correspondly rotate anvil bit 3 and insure an impacting action of cutting members 22 over substantially the entire cross-sectional area of the bottom 5 of the hole 4. During the impacting action, suitable drilling weight is imposed on anvil bit 18 and housing structure 10, such drilling weight being transferred from the lower end 24 of drive sub 15 to an upwardly facing shoulder 25 of the bit. The rotary drive itself is transferred from housing structure 10 to anvil 18 through a suitable spline connection 26, which can assume several different forms, the particular drive connection illustrated constituting no porportion of the present invention. This drive connection is illustrated in several prior patents issued to applicant.
In general, the upper portion of the anvil 18 has circumferentially space elongate grooves 27 (FIG. 4), in which segments 28 are disposed, these segments being carried in circumferentially spaced windows 29 in drive sub 15. Grooves 27 are substantially longer than the length of segment 28, permitting relative longitudinal movement of anvil bit 3 with respect to the housing structure 10. The rotary effort is transferred from the housing section 14 to the drive sub 15 by means of the threaded connection 130 and from the side of windows 29 to segments 28, from where the turning effort is transmitted through segments 28 and grooves 27 to the anvil bit.
The housing section 14 includes an upper inner cylindrical housing wall 30, the lower end 31 of which constitutes an upper housing flow control corner at the upper end of an elongated internal circumferential exhaust groove 32 of a substantially larger internal diameter in the diameter of the inner cylindrical housing wall 30. Disposed substantially below the lower end 33 of exhaust groove 32, housing section is provided with a lower inner cylindrical housing wall 34, which may be of the same internal diameter as the upper housing wall 30, the upper end of the lower wall being the housing lower flow control corner 33. The lower end 35 of lower inner cylindrical housing wall 34 provide a bypass corner at the upper end of an enlarged internal diameter circumferential bypass groove 36. Similarly, the housing has an enlarged internal diameter circumferential bypass groove 136 immediately above the lower corner 33.
The elongate hammer piston 20 includes an upper piston portion 37 having an external diameter 137 conforming to the diameter of the upper inner cylindrical housing wall 30, this upper piston portion terminating at the upper end 38 of an elongate external circumferential exhaust groove 39 or piston relief portion of a lesser external diameter than the upper piston portion 37. This external exhaust groove terminates at a lower piston portion 40 having an external diameter conforming to the internal diameter of the lower inner cylindrical housing wall 34. Below its lower piston portion, the hammer is of a reduced external diameter 41, providing a downwardly facing shoulder 42 which may, upon removal of the anvil bit 3 from the housing 10, engage a limit ring 43 mounted in the housing section 14, to prevent the piston 20 from inadvertently dropping out of the housing structure. The hammer piston has an upper guide portion 138 separated by a circumferential groove 139 from the upper piston portion 37. This upper guide portion has a plurality of circumferentially spaced relief portions 44 which may be formed by cords extending from the upper end of groove 139 to the upper end of 46 of the guide portion 138, there being circumferentially spaced elongate arcuate sections 47 between the relief portions 44 having the same external diameter as the upper piston portions 37 and assisting in guiding the hammer piston 20 in its reciprocation along the inner wall of the housing section 14.
As described herein below, when the hammer piston 20 is at the lower end of its stroke, as shown in FIGS. 1A and 1B, a flow control piston corner 50 at the upper end of the piston portion 37 is spaced below the upper housing flow control corner 31, allowing air in the housing above the piston 20 to flow down through the passages 44 and into the internal circumferential exhaust groove 32, around the upper piston portion 37, then through the lower portion of the groove 32 and the grooves 39 and 136 into radial exhaust ports 51, formed through the hammer piston below its intermediate piston wall 52, that communicate with a elongate central piston cavity 53 into which an exhaust tube 54 extends upwardly from the anvil 18, the tube forming a continuation of exhaust passage 53 and communicating with an exhaust passage 55 through the anvil and one or a plurality of exhaust passages 56 extending downwardly through the bit 21 and opening outwardly thereof for the purpose of removing cuttings from the bottom 5 of the hole. The tube 54 makes a slidable seal with the wall 153 of the piston cavity 53, being secured to the anvil 18 by a outwardly extending tube flange 57 being received within an inner circumferential groove 58 in the anvil. The tube may be made of a suitable elastic or plastic material, such a Delrin, which permits it to be inserted within the anvil passage, the flange 57 contracting sufficiently until it is opposite the circumferential groove 58, whereupon the tube flange can snap outwardly into groove 58 and thereby lock the exhaust tube 54 in the anvil 18.
When piston 20 is shifted upwardly within the housing on its return stroke, the return air corner 60 at the lower end of the lower piston portion 40 will be disposed above the housing lower flow control corner 33 (FIGS. 2A and 2B), whereupon the compressed air below the piston can exhaust into the internal circumferential housing groove 136 and flow through the exhaust ports 51 and exhaust passages 53, 55, 56 to the bottom 5 of the bore hole 4. At this time, the upper flow control piston corner 50 will be disposed above the upper housing flow control corner 31, which will seal the upper piston portion 37 against the upper inner cylindrical housing wall 30, whereupon compressed air can drive the piston 20 downwardly on its hammer or power stroke. When the return air corner 60 moves below the housing lower flow control corner 33, the air below the piston and within the housing, which remains after the lower piston portion 40 is closed within the lower end of the cylindrical housing wall 34, is subject to compression, but such air will be at a relatively low pressure.
As described herein below, in the event the apparatus elevated to raise the bit from the bottom 5 of the hole 4, the bit will drop downwardly until its upper anvil shoulder 111 engages the upper ends of the segments or keys 28. This will allow the upper piston bypass corner 62 of the lower piston portion 40 is shift below the housing bypass corner 35 at the lower end of the lower inner cylindrical housing wall 34, the upper flow control piston corner being well the upper housing flow control corner (FIGS. 3A and 3B). Accordingly, compressed air above the piston can flow through the passages 44 and the circumferential exhaust grooves 32, 39, 136 into the air bypass groove 36 below the lower housing wall 34, the air passing downwardly through the passage 63 in the upper portion of driver sub 53 and into the clearance around drive segments 28 and into grooves 27 in anvil 18, and outward through the clearance between drive sub 15 and anvil 18.
Compressed air for reciprocating in the hammer piston 20 passes downwardly through the string of drill pipe 2 and into the upper housing sub 11, flowing past a downwardly opening check valve 70. The check valve includes valve head 71 which is urged toward a closed position against valve seat 72 in sub 11. Valve head 71 fits slidably within the bore 73 of an upwardly extending tubular extension 74 on valve cage 75. A spring 76 is positioned within the bore 73 and rests at one end against inwardly extending circumferential flange 170 and at the other end urges valve head 71 toward closed position against valve seat 72. Valve cage 75 has a peripheral flange 171 which seats against shoulder 172 in housing section 14. Make-up ring 173 is positioned against the upper side of flange 171 and is engaged by the lower end of upper sub 11 when screw connection 110 is tightened. When valve head 71 is moved away from valve seat 72 by pressure of compressed air, the compressed air flows into annular passage 177 and thence through passages 174 in valve cage 75 into the bore 178 of the downwardly extending tubular extension 175 of cage 75.
The inlet air under pressure is caused to flow alternately into the housing below the piston 20 and the housing above the piston, to effect reciprocation of the hammer piston. A feeder tube 78 is mounted in the bore 178 of tubular extension 175 of valve cage 75. The upper end of feeder tubes 78 has a flange 179 which fits in groove 176 into tubular extension 175 of valve cage 75. Feeder tube 78 projects downwardly into an upper elongate central piston cavity or chamber 79 above the intermediate piston wall 52, which separate the upper chamber 79 from the lower chamber 53. An orifice member 150 having an orifice 151 may be press fit in the wall 52. Feeder tube 78 is secured in valve cage 75 by a flange fitting into a groove therein as described above. Feeder tube 78 is made of a flexible plastic or elastic material, such as Delrin, which permits the upper portion of the tube to be deflected inwardly of the valve cage passage 178 below the circumferential groove 176, and when the flange 179 becomes aligned with the groove, the flange inherently expands outwardly into the groove to secure the feeder tube in the valve cage 75. The elastic nature tube is such that it also provides a slidable seal with the inner walls of the piston 20, as explained herein below.
The piston has an elongate upper cylindrical surface 82 opening through its upper end 46 and terminating at an inner, upper flow control piston corner 83, which is the upper end portion of an elongate internal circumferential impact passage groove 84 having a substantially larger internal diameter than the inside diameter of the upper piston portion surface 82. The circumferential impact passage groove 84 terminates at an intermediate inner cylindrical piston wall 85, which may have the same internal diameter as the upper cylindrical piston wall 82, the intermediate wall terminating at an internal circumferential return passage groove 86 formed in the piston and terminating at a lower flow control piston corner 87, which is the upper end of a lower internal piston seal portion 88 that extends upwardly from the intermediate piston wall 52. Feeder tube 78 has an upper external cylindrical sealing surface 89 relatively slidably sealable with the upper piston wall 82 and terminating in an external circumferential inlet groove 90 communicating with radial inlet ports 91 opened to the central inlet passage 92 through the tube. Below this circumferential inlet groove 90 the tube is formed as a lower cylindrical sealing surface 93 slidably and sealingly engageable with the intermediate inner cylindrical wall 85 and also with the lower piston wall 88. Labyrinth grooves 190 are provided in the tube surfaces 89 and 93 to enhance the sealing effectiveness of the surfaces 89, 93 with the walls 82, 85.
When the piston 20 is in its lower most operative position with the drill bit 21 pressed against the bottom 5 of the bore hole 4, compressed air can flow downwardly through the inlet passage 92, discharging into the circumferential return passage 86 that communicates with the upper portion of one or more longitudinal return passages 95 extending downwardly through the hammer piston and opening outwardly through its lower end 96. When the hammer piston 20 moves upwardly within the housing 10 and along the feeder tube 78, the lower flow control piston corners 87 first shifts upwardly over the flow control housing tube corner 193 to disrupt communications between the inlet passage 92 and the return passages 95, continued upward movement of the piston then placing the inner upper flow control piston corner 83 above the upper flow housing tube corner 98, which then allow compressed air to flow from the inlet passage 92 through the ports 91 into the circumferential inlet groove 90 into the internal circumferential impact passage groove 84 and thence into the housing above the upper end 46 of the piston (FIGS. 2A & 2B). At this time, the upper piston corner 50 will have moved partially above the upper housing flow control corner 31, so that the air under pressure between the upper end 46 of the piston and the underside of valve cage 75 connect downwardly on the piston, urging it in a downward direction.
The piston 20 will be shifted downwardly until the upper flow control piston corner 83 moves below the flow control housing tube corner 98, which shuts off air pressure into the housing above the piston, the piston continuing to move downwardly, as the compressed air expands, until the outer upper flow control piston corner 50 moves below the upper housing flow control corner 31, which then permits air above the piston to pass through the passages 44 into the circumferential exhaust grooves 32, 39, 136 and through the exhaust ports 51 and exhaust passages 53, 55, 56 to the bottom of the hole below the drill bit, the hammer piston being driven against the upper face 100 of the anvil to deliver an impact below to the anvil bit. As the piston nears the end of its downward stroke, the lower flow control piston corner 87 will move below the lower flow control housing tube corner 193, thereby allowing compressed air to flow from the inlet passage 92 through the ports 90 into the groove 84, flowing through the annular passage between the tube and wall 85 into the return passage groove 86, passing downwardly through the longitudinal return passages 95 to the lower end of the piston, such air then moving the piston in an upward direction, until the lower flow control piston corner 87 passes upwardly beyond the lower flow control housing tube corner 193 once again, to shut off the flow of air into the return passages 95. When this occurs, the outer upper flow control piston corner 50 moves above the upper housing flow control corner 31 to shut off the exhaust of air from the housing reaching above the piston 20, the compressed air below the piston expanding and driving the hammer piston upwardly toward the valve cage 75. Before reaching the valve cage 75, the inner upper flow control piston corner 83 will have shifted upwardly along feeder tube 78 to a position above the upper flow control housing tube corner 98, allowing air under pressure to flow from the inlet passage 92 through the impact passage grooves 90, 84 to a position in the housing above the piston 20.
The upward travel of the piston 20 is cushioned by the compression of air remaining in the housing of the piston. However, the piston will still move upwardly sufficiently to place the lower corner 60 of the lower piston portion 40 above the housing lower flow control corner 33, which then permits compressed air below the piston to travel into the internal circumferential exhaust groove 32 and through the exhaust ports 51 into the exhaust passages 53, 55, 56 for discharge from the drill bit. The compressed air in the housing structure above the piston then expands to drive the piston downwardly, and the foregoing cycle of operation is repeated, the piston reciprocating to deliver repeated impact blows against the anvil portion 18 of the anvil bit 3, while the drill string 2 and the entire apparatus 1 is being rotated, to insure that the drilling or cutting elements 22 will cover substantially the entire cross-sectional area of the bore hole bottom 5.
The hammer piston also has a lower guide portion 138 spaced downwardly from the lower piston portion 40 and slidable along the walls 34 and 134 below the groove 36 when the piston is approaching or is at its upper most and lower most positions. The lower guide also has the same relief portions 44 as the upper guide 138.
In the event it is desired to pump compressed air through the apparatus while the drill bit is off bottom, the elevation of the apparatus 1 will cause the impact bit 3 to drop downwardly along the housing until the upper anvil head 111 engages the upper ends of the keys 28 (FIGS. 3A, 3B). The piston 20 will also drop downwardly until its bypass corner 62 is below the bypass corner 35 of the housing 10, the upper corner 62 of the piston being disposed below the upper end of the internal circumferential groove 36. Accordingly, compressed air flowing downwardly through the drill string 2 and into the inlet passage 92 can pass through the inlet port 91 and upwardly to a position above the piston, then flowing downwardly through the upper passages 44 and into the internal circumferential exhaust groove 32, flowing between the external circumferential exhaust groove 39 in the piston and the opposed lower inner cylindrical housing wall 34 into the enlarged diameter groove 36 below the inner cylindrical housing wall, then passing through the lower passages 44 in the lower guide 138 and through the passages 63, 64, 27, 67 to the exterior of the bit. The major portion of the compressed air will flow around the upper piston 37 through the grooves 32, 136, ports 51 and passages 53, 55, 56 to the exterior of the bit, to clean the bore hole 4 of cuttings.
As described above, the exhaust tube or sleeve 54 is made of elastic material, which is a suitable synthetic resin or plastic such as Delrin. This sleeve must make the slidable seal within the wall 153 of the piston cavity 53 to prevent or minimize leakage of air between the tube and the wall 153. Because of the manufacturing tolerances, a perfect alignment between the hammer piston 20 and the anvil 18 may not exist. Accordingly as the piston approaches the anvil and impacts thereagainst, it imposes a lateral force on the exhaust sleeve 54. If the exhaust tube made a close fit with the wall 158 of the anvil downwardly from its upper face 100, even a small amount of misalignment between the piston and the anvil would cause a high shearing stress to be imposed on the exhaust tube 54, resulting in fatigue failure of the exhaust tube after a relatively short period of use of the apparatus.
The above difficulty is overcome in the apparatus illustrated by providing a very slight relief between the exterior of the exhaust tube or sleeve 54 and the wall 158 of anvil 18, such relief extending downwardly from the upper anvil face 100. The relief may be in the form of a very slight counterbore or a slight thinning of the wall thickness of the exhaust tube. With this small clearance between the tube and the wall 158 of the bore, any misalignment between the piston and anvil 18 will not produce a high shearing stress on the exhaust tube but rather deflect or bend the tube laterally. The bending stresses to which the tube 54 is subjected, as a result of misalignment between the piston 20 and anvil 18, are maintained at a comparatively low value, which prevents the exhaust tube or sleeve 54 from early fatigue failure.
As illustrated in the drawings, an orifice member 150 has been disposed in the intermediate piston wall 52 to permit excess air flow through the feeder tube 78, chamber 79, the orifice 151, central piston cavity 73, exhaust tube 54, anvil passage 55, and its exhaust passages 56 into the well bore. The ability to bypass the volume of air directly to the bit through the choke member insures a maximum hole cleaning action without inhibiting the action of the compressed air on the hammer piston. The choke member is used when the volume of air at a desired unit pressure is much greater than that required to operate the hammer bit, the size of the choke being so selected that the surplus volume of air is permitted to pass directly through the bit. The use of the surplus volume of air for the purpose of cleaning the well bore of cuttings allows the high volume compressor to run at top efficiency. As the surplus volume of air available becomes greater, a larger size choke member 150 would be installed within the piston. When no excess volume of air is available, the choke orifice member 150 would be replaced by a blank member; that is, one having no orifice 151 through it, so that all of the air supplied by the compressor is available reciprocating the piston within the housing.
It is further to be noted that the choke orifice member 150 is to be disposed above the radial exhaust ports 51. The exhaust from the choke orifice 151 flows past the radial ports 51 and tends to reduce the pressure therein, thereby assisting in the flow of exhaust air through the ports and through the passages 53, the tube 54 and the anvil passages 55, 56 into the bore hole.
In the hammer drill illustrated in the drawings, the upper and lower piston portions 37, 40 are at the ends portions of the piston, being spaced longitudinally from one another by a substantial extent, these piston portions being separated by the elongate relief portion 39 which does not contact the wall of the hole. The upper and lower guide portions 138, 140 may contact the upper housing wall 30 and the lower walls 34, 134, but such guide portions and their adjacent piston portions 37, 40 engage their respective housing walls over a relatively small extent. During the drilling operation, the drilling weight and the port imposed on the housing structure 10 causes its flexing, tending to create the binding action on the reciprocating piston 20. Such binding action is minimized by virtue of the minimum wall contact between the greatly longitudinally spaced upper and lower portions 37, 40 of the piston with the housing, and by the fact that the central inlet and exhaust tubes 78, 54 are made of flexible or elastic material. Accordingly, flexing of the housing is accompanied by a companion lateral movement or tilting of the piston 20, so that it can follow the deviations in the housing structure during its reciprocation in the latter. Such lateral shifting is permitted, since the feeder in exhaust tube 78, 54, which are made of flexible or elastic material, can partake of a lateral or bending movement. If these tube members were made of rigid material, the piston could not shift laterally or tilt as a result of deflection of the housing structure 10, creating a binding action between the piston portions 37, 40 of the piston and the housing structure. In the absence of the extensive longitudinal spacing between the piston portions 37, 40 and the flexible tube members 78, 54, a binding action would occur. By virtue of the arrangement illustrated in the drawings, the ability of the piston 20 to shift or tilt as the housing deflects prevents excessive contact pressures between the piston and the housing wall, preventing galling of the parts and ultimate failute of one or more of them.
The apparatus as thus far described, is designed for operation with compressed air at a variety of pressure and flow rate settings as may be encountered in field operation. It is a characteristic of this air hammer design, as far as described above, that an increase in air pressure results in a corresponding increase in the volume of air required to operate the air hammer. Thus, a six inch hammer of this type requires 550 SCFM of air volume to operate at 225 psi. However, there are many drilling rigs in the field with compressor rated at 425-450 SCFM at 250 psi. On these machines, a six inch hammer of this design would operate at 170-185 psi (compressors seldom deliver their rated volume). The drilling operators in the field havd indicated a substantial demand for an air hammer that will operate at a lower volume of air or flow rate when operated at a higher pressure. This demand has currently been met by a total redesign of a variety of commercial air hammers which are designed to run at higher pressure and low volume. There has been a substantial need for a hammer which has flexibility in operation and which can be operated with variable volumes of air and variable air pressures.
The need for an air hammer which will operate with a lower volume of air when operated at higher air pressures has been met in this hammer design by the addition of an annular plug member or plastic ring 191 which fits on tubular extension 175 of valve cage 75 and is held in place by a barb 192 thereon. The addition of annular plug member or plastic ring 191 results in a decrease in the volume of the air space above the hammer piston when in its upper most position. This reduces very substantially the volume of air required to operate the air hammer when operated with higher pressure compressed air.
The variable volume concept which is introduced by the use of an annular plug or plastic ring 191 may be extended to provide an air hammer design which will operate at a large variety of air pressures and flow rates. In order to provide for a air hammer design allowing for a substantial flexibility in air pressure and air flow rates the dimension "C" extending from the flange 171 of valve cage 75 to the upper surface of the hammer piston when in the upper most position is extended so that the volume of the air space above the hammer piston in the absence of annular plug or plastic ring member 191 requires 1,000 SCFM air to operate the hammer at 250 psi. The addition of an annular plug member or plastic ring 191 of predetermined size will adjust the volume of air space above the hammer piston so that 425 SCFM will produce operation at 225 psi. A variety of intermediate size annular plug members or plastic rings can be provided which will produce the desired operation on compressors which operate at higher volumes viz. 600, 700, 800 SCFM etc. When air hammers are used with annular plug members or plastic rings 191 which permit operation at these selected higher volumes, it is preferred to optimize the air hammer operation by adjusting the timing of the air hammer to correspond to the pressure and air flow rate. Optimizing the timing of air hammer operation requires a variation in the spacing of the intake air porting. The dimensions "A" and "B" determine the intake port timing. These dimensions are determined for the particular air pressure and volume of air to be used as determined by the originally selected dimension "C" required for high volume low pressure operation. Dimensions "A" and "B" can be determined for a particular pressure and air flow rate to correspond to the size of a particular annular plug or plastic ring 191. Since the annular plug 191 and feeder tube 78 are both of elastic plastic material and since these are replaceable components, these parts are provided as matched sets. They are preferably color coded so that a given color feeder tube and annular plug are used together to provide the desired operating characteristics and timing of air hammer operation. This replaceability of the feeder tube and annular plug members results in an air hammer design which is fully adjustable in the air pressure and volume of air which can be used. The design of these components is such that it is possible to operate air hammers at a variety of air pressures and to use the lower volumes of air flow as the air pressure is increased and by the corresponding change in the proportions of the feeder tube to optimize the timing of operation of the hammer piston. | A Pneumatic impact drilling tool, particularly useful as a downhole pneumatic drill, includes a housing structure adapted to be connected to a string of drill pipe and supplied with compressed air therethrough. A hammer piston reciprocates in the housing structure along flexible feed and exhaust tubes. Compressed air is directed alternately to the upper and lower ends of the hammer to effect its reciprocation in the housing. The hammer is operable to strike an anvil bit member repeatedly to effect a drilling motion. At the upper end of the housing there is provided a removable annular plug member surrounding the tubular support in which the feeder tube is positioned. The annular plug member defines the volume of the space above the hammer piston and is related to the size of the feeder tube so that the feeder tube and plug member together determine the volume of air utilized at any selected air pressure and the timing of operation of the hammer position. The feeder tube and plug member are removably positioned on the supporting member as a set and maybe replaced with like sets of feeder tubes and plug members of different size to permit the operation of the drilling tool at various selected air flow rates and air pressures. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit and priority of U.S. Provisional Patent Application No. 61/471,222, filed Apr. 4, 2011, the entire disclosure of which is incorporated herein by reference.
FIELD
The present disclosure generally relates to a clutch mechanism and to a decoupler device with a clutch mechanism.
BACKGROUND
This section provides background information related to the present disclosure which is not necessarily prior art.
Serpentine accessory drive systems for automotive vehicles are commonly used to transfer power, via associated pulleys, from an internal combustion engine crankshaft to accessory components such as alternators, water pumps, power steering pumps, and air conditioning compressors. Under operating conditions where the crankshaft slows suddenly, high-inertia components of the accessory drive will tend to load the serpentine belt such that the belt may squeal or slip, and/or vibrate, and/or cause the tensioner and/or accessory components to vibrate.
It is known to counter this effect with an over-running decoupler, which may be positioned on one of the high-inertia components or on the engine crankshaft. Examples of such devices are disclosed in U.S. Pat. Nos. 7,618,337; 7,591,357 and 7,624,852. While such devices are well suited for their intended purpose, we have noted that it would be desirable to lock, bypass or otherwise transmit rotary power through the over-running decoupler in some situations. One such situation involves a BAS (i.e., “belt-alternator-starter”) system in which a belt-driven alternator may be operated as a starter motor that will provide rotary power to the serpentine belt for rotating the crankshaft during starting of the internal combustion engine.
An overrunning-enabled automotive starter generator is disclosed in International Publication No. WO 03/104673 (International Application No. PCT/CA03/00852) published Dec. 18, 2003. While such device is suited for its intended purpose, there remains a need in the art for an improved clutched device.
SUMMARY
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
In one form, the present teachings provide a clutched device that includes a pulley, a shaft member, a first one-way clutch having a first wrap spring, and an actuator having an electromagnetic coil and an armature. The first one-way clutch rotationally couples the pulley and the shaft member when the actuator is actuated and rotary power is transmitted from a first one of the pulley and the shaft member to the other one of the pulley and the shaft member in a first rotational direction. A frictional force is applied to the armature when the actuator is activated. The frictional force is configured to resist rotation of the armature to cause the first wrap spring to radially expand into driving engagement with a clutch surface that is coupled to the pulley for common rotation.
In another form, the present teachings provide a clutched device that includes a housing, a shaft member, a pulley, an over-running decoupler, a one-way clutch, and an actuator. The over-running decoupler rotationally couples the shaft member and the pulley when rotary power is transmitted from one of the shaft member and the pulley to the other one of the shaft member and the pulley in the first rotational direction. The over-running decoupler does not transmit rotary power between the shaft member and the pulley when the other one of the shaft member and the pulley overruns the one of the shaft member and the pulley in the first rotational direction. The one-way clutch has a wrap spring. The actuator is configured to control operation of the one-way clutch and includes an armature. The one-way clutch rotationally couples the pulley and the shaft member when the actuator is actuated and rotary power is transmitted from the first one of the shaft member and the pulley to the other one of the shaft member and the pulley in the first rotational direction. A frictional force is applied to the armature when the actuator is activated. The frictional force is configured to resist but not inhibit rotation of the armature relative to the housing to cause the first wrap spring to radially expand into driving engagement with a clutch surface that is coupled to the pulley for common rotation.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
FIG. 1 is a schematic illustration of a first exemplary clutch controlled decoupler constructed in accordance with the teachings of the present disclosure and shown in operative association with an internal combustion engine;
FIG. 2 is an exploded perspective view of the clutch controlled decoupler of FIG. 1 ;
FIG. 3 is a perspective longitudinal section view of the clutch controlled decoupler of FIG. 1 ;
FIG. 4 is an enlarged portion of FIG. 3 ;
FIG. 5 is a schematic illustration of a second exemplary clutch controlled decoupler constructed in accordance with the teachings of the present disclosure and shown in operative association with an internal combustion engine;
FIG. 6 is an exploded perspective view of the clutch controlled decoupler of FIG. 5 ;
FIG. 7 is a perspective longitudinal section view of the clutch controlled decoupler of FIG. 5 ;
FIG. 8 is a perspective longitudinal section view of a driven accessory with a clutch unit constructed in accordance with the teachings of the present disclosure;
FIG. 9 is an exploded perspective view of a third exemplary clutch controlled decoupler constructed in accordance with the teachings of the present disclosure;
FIG. 10 is an exploded perspective section view of the clutch controlled decoupler of FIG. 9 ; and
FIG. 11 is a longitudinal section view of the clutch controlled decoupler of FIG. 9 .
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
With reference to FIG. 1 of the drawings, a first clutch controlled decoupler constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10 . The clutch controlled decoupler 10 can be employed in a front engine accessory drive 12 of an internal combustion engine 14 . The front engine accessory drive 12 can include a plurality of engine accessories, such as a water pump 16 , an air conditioning compressor 18 and a starter/generator or starter/alternator 20 that can be driven by the crankshaft 22 of the engine 14 via a belt 24 and the clutch controlled decoupler 10 . Those of ordinary skill in the art will appreciate that the particular example provided pertains to a BAS (belt-alternator-starter) system because the front engine accessory drive 12 includes a starter/generator. It will be appreciated, however, that the BAS system could be equipped to additionally provide an idle-stop-accessory function in which the starter/generator is operated as an electric motor to input rotary power to (i.e., drive) the belt 24 of the front engine accessory drive 12 when the crankshaft 22 is not being driven by the engine 14 . As those of skill in the art will understand, the idle-stop-accessory function permits various accessories, such as the water pump 16 and the air conditioning compressor 18 to be operated when the engine 14 is not being operated.
With reference to FIGS. 2 through 4 , the clutch controlled decoupler 10 can comprise a decouper 30 and a clutching unit 32 . Except as described herein, the decoupler 30 , which can also be considered to be a one-way clutch, can be generally similar to the decoupler disclosed in International Patent Application No. PCT/CA2010/000296, but it will be appreciated that the decoupler 30 could be similar to any other suitable decoupler, including that which is described in U.S. Pat. No. 7,624,852. The disclosures of the aforementioned patent application and patent are incorporated by reference as if fully set forth in detail herein.
The clutching unit 32 can comprise an actuator 40 and a clutch assembly 42 . The actuator 40 can comprise a coil assembly 50 and an armature 52 , while the clutch assembly 42 can include an output member or shaft member 60 , an input member or hub 62 , and a clutch element 64 .
With specific reference to FIGS. 2 and 4 , the coil assembly 50 can comprise a coil mount 70 and an annular coil 72 . The coil mount 70 can comprise an annular flange 76 and an annular coil housing 78 that can be fixedly coupled to and extend from the annular flange 76 . The annular flange 76 can be adapted to be fixedly coupled to the front cover 80 ( FIG. 1 ) of the engine 14 ( FIG. 1 ) such that a front hub 82 of the crankshaft 22 can extend therethrough. The coil 72 can be received in the coil housing 78 and can be positioned radially outwardly from the front hub 82 of the crankshaft 22 .
The armature 52 can be formed of a magnetically susceptible material, such as steel, and comprise a pole member 90 , an input flange 92 and an annular spacing member 94 that can extend axially and concentrically about the coil 72 . The pole member 90 can be coupled to a first end of the spacing member 94 and can extend radially outwardly therefrom so as to be positioned axially in-line with the coil 72 . The input flange 92 can be coupled to a second, opposite end of the spacing member 94 and can extend radially inwardly therefrom.
The shaft member 60 of the clutch assembly 42 can be fixedly coupled to the front hub 82 of the crankshaft 22 and can be coupled to or form an input member of the decoupler 30 (i.e., the hub spacer identified by reference numeral 30 in International Patent Application No. PCT/CA2010/000296). In the particular example provided, the shaft member 60 of the clutch assembly 42 is integrally formed with the hub spacer 100 of the decoupler 30 and comprises an annular flange 102 that is coupled to a rear side of the hub spacer 100 and an annular wall member 104 that extends rearwardly from the annular flange 102 . Threaded fasteners (not shown) can be received through the torsional vibration damper 106 and hub spacer 100 of the decoupler, and the hub 62 , and can be threadably engaged to holes 110 in the crankshaft 22 to fixedly couple both the torsional vibration damper 106 and the shaft member 60 to the crankshaft 22 . The annular wall member 104 can be disposed radially outwardly of the spacing member 94 of the armature 52 . A first bearing element 116 can be disposed between the spacing member 94 on the armature 52 and the annular wall member 104 . The first bearing element 116 can be configured to help maintain the armature 52 in an orientation that is disposed concentrically about the rotational axis of the crankshaft 22 , and/or to provide a lower friction surface on which the armature 52 may be translated.
The hub 62 can comprise a mounting flange 120 , an output flange 122 , and a coupling member 124 that can extend axially and concentrically about the armature 52 and the annular flange 102 . The mounting flange 120 can be coupled to a first end of the coupling member 124 and can extend radially outwardly therefrom. The mounting flange 120 can be coupled to the pulley 130 of the decoupler 30 for rotation therewith. Any desired means may be employed for retaining the mounting flange 120 to the pulley 130 , including welds, threaded fasteners 132 and/or rivets. In some situations, it may be possible to integrally form some or all of the hub 62 with the pulley 130 . The output flange 122 can be coupled to a second, opposite end of the coupling member 124 and can extend radially inwardly therefrom so as to be positioned axially in-line with the input flange 92 of the armature 52 .
The clutch element 64 can be configured to transmit rotary power from the hub 62 to the shaft member 60 and to inhibit the transmission of rotary power from the shaft member 60 to the hub 62 (i.e., the clutch element 64 can be configured to permit the transmission of rotary power between the hub 62 and the shaft member 60 in a first rotational direction and to inhibit the transmission of rotary power between the hub and the shaft member 60 in a second, opposite rotary direction). Those of skill in the art will appreciate that various types of clutch elements could be employed, including sprag clutches, synchronizers, mechanical diode clutches and roller/ramp clutches. In the particular example provided, the clutch element 64 comprises a wrap spring 140 that is mounted coaxially between the annular wall member 104 on the shaft member 60 and the coupling member 124 on the hub 62 . The wrap spring 140 can be formed of wire and can comprise a first end 142 , a second end 144 , and a plurality of wire coils 146 that can extend axially between the first and second ends 142 and 144 . The wire can have any appropriate cross-sectional shape, including a generally square or rectangular cross-sectional shape that can be configured to engage a clutch surface 150 formed on coupling member 124 of the hub 62 . The wrap spring 140 can be wound in a manner such that the coils 146 of the wrap spring 140 can expand radially when rotary power is transmitted between the hub 62 and the shaft member 60 in the first rotational direction (i.e., as when rotary power is input to the crankshaft 22 via the pulley 130 ) and can contract radially when the shaft member 60 rotates in the first rotational direction relative to the hub 62 (i.e., as when the shaft member 60 is directly driven by a source or rotary power, such as the crankshaft 22 of an engine). If desired, a lubricant may be employed to lubricate the interface between the wrap spring 140 and the clutch surface 150 , such as an oil (including “traction fluids”), grease, paste, film or coating. It will be appreciated that in some instances, it may be desirable to include one or more seals (not shown) between the several components, such as between the hub 62 and the pulley 130 or between the hub 62 and the shaft member 60 , and/or between the hub 62 and the coil mount 70 , for example, to inhibit the egress of the lubricant from the interior of the clutching unit 32 and/or to inhibit the ingress of dirt, debris and/or moisture into the interior of the clutching unit 32 . Alternatively, one or more labyrinths may be formed between the several components to generate tortuous paths by which the lubricant would need to travel to exit the interior of the clutching unit 32 and by which dirt, debris and/or moisture would need to travel to enter the interior of the clutching unit 32 .
In the example provided, a carrier 160 is employed to non-rotatably couple the first end 142 of the wrap spring 140 to the shaft member 60 and a spring support or thrust ring 164 is employed to couple the second end 144 of the wrap spring 140 to the hub 62 .
The wrap spring 140 and the carrier 160 can be coupled to one another in a manner that is similar to the manner in which the wrap spring and the carrier are coupled to one another in FIGS. 13 and 14 of International Patent Application No. PCT/CA2009/001660, the related disclosure of which is hereby incorporated by reference. In brief, the carrier 160 can be an annular structure or cartridge onto which the wrap spring 140 is assembled. The carrier 160 can be formed of any desired material, such as an engineering nylon, and can define an aperture 170 , a slot (not shown) and one or more lug recesses (not shown). The aperture 170 can be sized to receive the annular wall member 104 of the shaft member 60 therethrough such that the carrier 160 may be abutted axially against the annular flange 102 . The slot can be configured to receive the first end 142 of the wrap spring 140 and to orient an axial end face 180 of the wire that forms the wrap spring 140 against a corresponding face 182 formed on a lug 184 that is coupled to the shaft member 60 for rotation therewith. The lug recess(es) can be employed to inhibit or limit rotational movement of the carrier 160 relative to the shaft member 60 and/or to position the carrier 160 such that the axial end face 180 will abut the face 182 on the lug 184 . In the example provided, the shaft member 60 comprises a single lug 184 and the carrier 160 comprises a single mating lug recess that defines radially extending walls that are abutted against radially extending faces on the lug 184 ; the slot in the carrier 160 intersects one of the radially extending walls on the lug recess so that the axial end face 180 may be abutted directly against a corresponding radially extending face 182 on the lug 184 . Configuration in this manner permits rotational energy collected by the wrap spring 140 to be transmitted axially through the first end 142 of the wrap spring 140 (i.e., in a direction along the longitudinal axis of the wire that forms the first end 142 of the wrap spring 140 ) such that at least a majority of the rotational energy transmitted between the wrap spring 140 and the hub 62 exits the wrap spring 140 through the axial end face 180 . It will be appreciated, however, that the interface between the first end 142 of the wrap spring 140 , the carrier 160 and the shaft member 60 can be configured somewhat differently than that which is shown in the drawings and heretofore described in this text and that these different configurations are nonetheless within the scope of the present disclosure. For example, the first end 142 of the wrap spring 140 could be configured to transmit all or a portion of the rotational energy to the carrier 160 and the carrier 160 can be configured to transmit rotary power to the shaft member 60 .
A retaining ring 190 can be mounted on the annular wall member 104 on the shaft member 60 and can limit or inhibit movement of the carrier 160 in an axial direction away from the annular flange 102 .
The thrust ring 164 can be generally similar to that which is disclosed in U.S. Provisional Patent Application No. 61/432,907, the disclosure of which is incorporated by reference as if fully set forth in detail herein. The thrust ring 164 can comprise a first spacer portion 200 and a second spacer portion 202 . The first spacer portion 200 can be somewhat smaller in diameter than the clutch surface 150 and can abut the wrap spring 140 on a side opposite the carrier 160 . The side of the first spacer portion 200 that abuts the wrap spring 140 can include a helical spacer ramp 206 that can match (and thereby directly abut) the wire that forms the wrap spring 140 . If desired, the thrust ring 164 can include a feature that can receive the second end 144 of the wrap spring 140 . In the particular example provided, the second end 144 is bent or hooked radially inwardly from the coils 146 at an approximately right angle; the second end 144 is received into a mating groove (not shown) that is formed in the thrust ring 164 to inhibit rotation of the thrust ring 164 relative to the second end 144 of the wrap spring 140 . The second spacer portion 202 can be a sleeve onto which the coils 146 of the wrap spring 140 can be received. A bushing 210 may be received between the coils 146 of the wrap spring 140 and one or both of the second spacer portion 202 and the retaining ring 190 and can help to maintain the coils 146 in an orientation that is concentric about the rotational axis of the crankshaft 22 .
In operation, the coil 72 is de-activated during operation of the engine such that rotational energy provided to the shaft member 60 and hub spacer 100 via the crankshaft 22 will cause corresponding rotation of the pulley 130 . Since the decoupler 30 is configured to permit relative rotation of the hub 62 (and therefore the shaft member 60 ) relative to the pulley 130 in the first rotational direction, any drag input to the wrap spring 140 (either through the coils 146 or through an interaction between the output flange 122 of the hub 62 , the input flange 92 of the armature 52 , the thrust ring 164 and the second end 144 of the wrap spring 140 ), the coils 146 of the wrap spring 140 will tend to radially contract away from and out of engagement with the clutch surface 150 on the hub 62 . Accordingly, the clutching unit 32 will not experience significant wear during operation of the engine.
When it is desired to input rotary power from the pulley 130 to the crankshaft 22 , as when employing a generator or alternator to start the engine (i.e., a belt-alternator-starter or BAS system), the coil 72 can be activated or energized to generate a magnetic field that attracts the pole member 90 to thereby axially translate the armature 52 . In the example provided, the armature 52 is translated in response to the energization of the coil 72 such that the input flange 92 on the armature 52 is in driving engagement with the output flange 122 on the hub 62 . Since the thrust ring 164 is non-rotatably coupled to the armature 52 and since the second end 144 of the wrap spring 140 is non-rotatably coupled to the thrust ring 164 , rotation of the armature 52 will cause the second end 144 of the wrap spring 140 to rotate with the hub 62 in the first rotational direction to thereby cause the coils 146 of the wrap spring 140 to radially expand into driving engagement with the clutch surface 150 on the hub 62 so that the hub 62 will be driven by the hub 62 through the clutch element 64 . In this regard, rotary power is received into the wrap spring 140 via the coils 146 and is transmitted axially through the wire that forms the wrap spring 140 to the lug 184 on the shaft member 60 . In this regard, the first end 142 of the wrap spring 140 pushes against the lug 184 to drive the shaft member 60 in the first rotational direction.
To provide idle-stop-accessory functionality, the coil 72 is de-activated when the starter/generator 20 ( FIG. 1 ) is operated to provide rotary power to the belt 24 ( FIG. 1 ) when the engine is not being operated. The belt 24 ( FIG. 1 ) will drive the pulley 130 . Since the decoupler 30 is configured to permit relative rotation of the hub 62 (and therefore the shaft member 60 ) relative to the pulley 130 in the first rotational direction, any drag input to the wrap spring 140 (either through the coils 146 or through an interaction between the output flange 122 of the hub 62 , the input flange 92 of the armature 52 , the thrust ring 164 and the second end 144 of the wrap spring 140 ), the coils 146 of the wrap spring 140 will tend to radially contract away from and out of engagement with the clutch surface 150 on the hub 62 . Accordingly, the clutching unit 32 will not experience significant wear during the provision of the idle-stop-accessory function.
If desired, a friction material 250 may be coupled to one or both of the output flange 122 and the input flange 92 to increase the performance associated with the rotational coupling of the armature 52 to the hub 62 .
With reference to FIG. 5 of the drawings, a second clutch controlled decoupler constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10 a . The clutch controlled decoupler 10 a can be employed in a front engine accessory drive 12 a of an internal combustion engine 14 a . The front engine accessory drive 12 a can include a plurality of engine accessories, such as a water pump 16 , an air conditioning compressor 18 and a starter/generator or starter/starter/generator 20 that can be driven by the crankshaft 22 of the engine 14 via a belt 24 and a crankshaft pulley 130 a.
With reference to FIGS. 6 and 7 , the clutch controlled decoupler 10 a can comprise a decoupler 30 a and a clutching unit 32 a . Except as described herein, the decoupler 30 a can be generally similar to the decoupler disclosed in International Patent Application No. PCT/CA2009/001803, but it will be appreciated that the decoupler 30 a could be similar to any other suitable decoupler, including those which are described in U.S. Pat. Nos. 7,618,337 and 7,591,357. The disclosures of the aforementioned patent application and patents are incorporated by reference as if fully set forth in detail herein.
The clutching unit 32 a can comprise an actuator 40 a and a clutch assembly 42 a . The actuator 40 a can comprise a coil assembly 50 a and an armature 52 a , while the clutch assembly 42 a can include an output member 60 a , an input member 62 a , and a clutch element 64 a.
The coil assembly 50 a can comprise a coil mount 70 a and an annular coil 72 a . The coil mount 70 a can comprise an annular coil housing 78 a that can be coupled to a housing 310 of an alternator or starter/generator 20 . In the particular example provided, the coil housing 78 a is received into a bore 312 that is formed in the housing 310 . The coil 72 a can be received in the coil housing 78 a and can be positioned radially outwardly from a shaft 316 of the starter/generator 20 .
The armature 52 a can be formed of a magnetically susceptible material, such as steel, and can comprises an annular pole member 90 a , an input flange 92 a , which can extend radially outwardly from the pole member 90 a , and a plurality of legs 330 that can extend axially from the pole member 90 a so as to be concentrically disposed about the shaft 316 of the starter/generator 20 .
The coil housing 78 a can be constructed in a manner that is generally similar to that which is described in International Patent Application No. PCT/CA2010/001246, the disclosure of which is incorporated by reference. More specifically, the coil housing 78 a can define a flange 122 a that can be configured to frictionally engage the armature 52 a to resist rotation of the armature 52 a relative to the housing 310 of the starter/generator 20 . If desired, a friction material 250 a may be coupled to one or both of the flange 122 a and the input flange 92 a to increase the performance associated with engagement of the input flange 92 a to the flange 122 a.
The output member 60 a can be coupled to or integrally formed with the pulley 130 a of the decoupler 30 a . In the example provided, the output member 60 a comprises a clutch surface 150 a that is formed on the pulley 130 a of the decoupler 30 a . The clutch surface 150 a can be defined by an annular groove 340 in the pulley 130 a of the decoupler 30 a that can be disposed radially between the (belt) grooves 342 on the exterior of the pulley 130 a and the internal components of the decoupler 30 a , including the torsion spring 350 , the clutch spring 352 , the hub 354 , and the spring carrier 356 . A plurality of apertures 360 can be formed through the rear end of the pulley 130 a and can intersect the annular groove 340 . The legs 330 of the armature 52 a can be received through the apertures 360 into the groove 340 .
The input member 62 a of the clutch assembly 42 a can be fixedly coupled to the hub 354 of the decoupler 30 a . In the particular example provided, the input member 62 a of the clutch assembly 42 a is an annular structure having one or more lugs or driver tabs 370 that extend radially outwardly from an annular body 372 . The annular body 372 can be received onto a necked down portion 376 on the hub 354 on a side opposite the torsion spring 350 of the decoupler 30 a . One or more of the driver tab(s) 370 can be engaged against a corresponding input tab 380 formed on the hub 354 to facilitate the transmission of rotary power from the hub 354 to the input member 370 as will be described in more detail, below.
The clutch element 64 a can be configured to transmit rotary power from the input member 62 a to the output member 60 a and to inhibit the transmission of rotary power from the output member 60 a to the input member 62 a (i.e., the clutch element 64 a can be configured to permit the transmission of rotary power between the input member 62 a and the output member 60 a in a first rotational direction and to inhibit the transmission of rotary power between the input member 62 a and the output member 60 a in a second, opposite rotary direction). Those of skill in the art will appreciate that various types of clutch elements could be employed, including sprag clutches, synchronizers, mechanical diode clutches and roller/ramp clutches. In the particular example provided, the clutch element 64 a comprises a wrap spring 140 a that is mounted coaxially between the (belt) grooves 342 on the pulley 130 a and the internal components of the decoupler 30 a , including the torsion spring 350 , the clutch spring 352 , the hub 354 , and the spring carrier 356 . The wrap spring 140 a can be formed of wire and can comprise a first end 142 a , a second end 144 a , and a plurality of wire coils 146 a that can extend axially between the first and second ends 142 a and 144 a . The wire can have any appropriate cross-sectional shape, including a generally square or rectangular cross-sectional shape that can be configured to engage the clutch surface 150 a formed on the output member 60 a . The wrap spring 140 a can be wound in a manner such that the coils 146 a of the wrap spring 140 a can expand radially when rotary power is transmitted between the input member 62 a and the output member 60 a in the first rotational direction (i.e., as when the starter/generator 20 is employed as a motor for starting the engine 14 a ( FIG. 5 ) through the front engine accessory drive 12 a ( FIG. 5 ) and can contract radially when the output member 60 a rotates in the first rotational direction relative to the input member 62 a (i.e., as when rotary power is input to the alternator via a belt drive). If desired, a lubricant may be employed to lubricate the interface between the wrap spring 140 a and the clutch surface 150 a , such as an oil (including “traction fluids”), grease, paste, film or coating.
In the example provided, a carrier 160 a is employed to non-rotatably couple the first end 142 a of the wrap spring 140 a to the input member 62 a and a thrust ring 164 a is employed to couple the second end 144 a of the wrap spring 140 a to the legs 330 of the armature 52 a.
The wrap spring 140 a and the carrier 160 a can be coupled to one another in a manner that is similar to the manner in which the wrap spring and the carrier are coupled to one another in FIGS. 13 and 14 of International Patent Application No. PCT/CA2009/001660, the related disclosure of which is hereby incorporated by reference. In brief, the carrier 160 a can be an annular structure or cartridge onto which the wrap spring 140 a is assembled. The carrier 160 a can be formed of any desired material, such as an engineering nylon, and can define an aperture 170 a , a slot (not shown) and one or more lugs 380 . The aperture 170 a can be sized to permit the carrier 160 a to be received into the groove 340 in the pulley 130 a so that the carrier 160 a may be abutted against the input member 62 a . The slot can be configured to receive the first end 142 a of the wrap spring 140 a and to orient an axial end face 180 a of the wire that forms the wrap spring 140 a against a corresponding face (not specifically shown) of one of the driver tabs 370 on the input member 62 a . In the example provided, the input member 62 a comprises a plurality of driver tabs 370 , and the carrier 160 a comprises a plurality of lugs 380 that are abutted in a circumferential direction against the driver tabs 370 .
Configuration in this manner permits at least a majority of the rotational energy transmitted from the hub 354 to the input member 62 a to be transmitted to the wire of the wrap spring 140 a directly through the axial end face 180 a of the first end 142 a of the wrap spring 140 a ; this rotational energy can be transmitted to the pulley 130 a through the plurality of coils 146 a of the wrap spring 140 a as will be discussed in more detail below. It will be appreciated, however, that the interface between the first end 142 a of the wrap spring 140 a , the carrier 160 a and the input member 62 a can be configured somewhat differently than that which is shown in the drawings and heretofore described in this text and that these different configurations are nonetheless within the scope of the present disclosure. For example, the carrier 160 a could be configured to receive all or a portion of the rotational energy from the input member 62 a , and the carrier 160 a could be configured to transmit this rotational energy to the first end 142 a of the wrap spring 140 a.
One or more bushings 390 can be employed to control the concentricity of the carrier 160 a about a rotational axis of the shaft 316 of the starter/generator 20 , as well as to limit forward axial movement of the carrier 160 a relative to the shaft 316 .
The thrust ring 164 a can be generally similar to that which is disclosed in U.S. Provisional Patent Application No. 61/432,907, the disclosure of which is incorporated by reference as if fully set forth in detail herein. The thrust ring 164 a can comprise a first spacer portion 200 a and a second spacer portion 202 a . The first spacer portion 200 a can be somewhat smaller in diameter than the clutch surface 150 a and can abut the wrap spring 140 a on a side opposite the carrier 160 a . The side of the first spacer portion 200 a that abuts the wrap spring 140 a can include a helical spacer ramp 76 a that can match (and thereby directly abut) the wire that forms the wrap spring 140 a . If desired, the thrust ring 164 a can include a feature that can receive the second end 144 a of the wrap spring 140 a . In the particular example provided, the second end 144 a is bent or hooked radially inwardly from the coils 146 a at an approximately right angle; the second end 144 a is received into a mating groove (not shown) that is formed in the thrust ring 164 a to inhibit rotation of the thrust ring 164 a relative to the second end 144 a of the wrap spring 140 a . The second spacer portion 202 a can be a sleeve onto which the coils 146 a of the wrap spring 140 a can be received.
In operation, the coil 72 a is de-activated during operation of the starter/generator 20 in a first or electric power generating mode in which rotational energy is transmitted from a belt drive (not shown) into the pulley 130 a for driving the shaft 316 . Since the clutching unit 32 a is configured to permit relative rotation of the output member 60 a (and therefore the pulley 130 a ) relative to the input member 62 a (and therefore the hub 502 ) in the first rotational direction, any drag input to the wrap spring 140 a during operation of the starter/generator 20 in the first mode will cause the coils 146 a of the wrap spring 140 a to radially contract away from and out of engagement with the clutch surface 150 a on the output member 60 a . Accordingly, the clutching unit 32 a will not experience significant wear during operation of the starter/generator 20 in the first mode.
When it is desired to operate the alternator in a second mode that provides a rotary output to the belt drive via the pulley 130 a , (i.e., as for providing rotary power for the starting of an internal combustion engine in a belt-alternator-starter or BAS system), the coil 72 a can be activated or energized to generate a magnetic field that attracts the pole member 90 a to thereby axially translate the armature 52 a . In the example provided, the armature 52 a is translated in response to the energization of the coil 72 a such that the input flange 92 a on the armature 52 a frictionally engages the flange 122 a on the coil housing 78 a to thereby resist rotation of the armature 52 a relative to the shaft 316 of the starter/generator 20 . Simultaneously, operation of the starter/generator 20 in the second mode will cause rotation of the shaft 316 , thereby causing rotation of the input member 62 a , which in turn introduces rotational energy into the wrap spring 140 a that would tend to cause the coils 146 a of the wrap spring 140 a to enlarge in a radial direction (to thereby drivingly engage the clutch surface 150 a on the output member 60 a ). Since the thrust ring 164 a is non-rotatably coupled to the armature 52 a and since the second end 144 a of the wrap spring 140 a is non-rotatably coupled to the thrust ring 164 a , operation of the coil 72 a to cause the armature 52 a to resist rotation will correspondingly impede rotation of the second end 144 a of the wrap spring 140 a . Non-rotation or impeded rotation of the second end 144 a of the wrap spring 140 a relative to the first end 142 a of the wrap spring 140 a ensures that torsion will be transmitted through the wrap spring 140 a to a degree that causes the coils 146 a of the wrap spring 140 a to drivingly engage the clutch surface 150 a to thereby transmit rotary power that is received from the input member 62 a to the output member 60 a (and thereby to the pulley 130 a ). As will be appreciated, rotational energy received by the wrap spring 140 a from the input member 62 a can be transmitted axially through the first end of the wrap spring 140 a to the plurality of coils 146 a , and through a plurality of the coils 146 a to the clutch surface 150 a.
It will be appreciated that the clutching unit 32 ( FIG. 2 ) of the present disclosure can have various other uses, including as a selectively operable clutch for operating an engine accessory. With reference to FIG. 8 , a clutching unit 32 b is illustrated in operative association with an engine accessory, such as a cooling fan. The clutching unit 32 b can be generally similar to that which is described in FIG. 1 , with the input member 60 b being coupled to the cooling fan pulley 130 b for rotation therewith and the output member 62 b being coupled to the cooling fan (not shown).
It will also be appreciated from this disclosure that the clutch unit 32 ( FIG. 2 ) may be incorporated into various other devices. For example, the clutch unit 32 ( FIG. 2 ) could be substituted for the clutch assembly that is disclosed in one or more of the examples described in International Patent Application No. PCT/CA2009/001660, the disclosure of which is incorporated by reference.
As noted above, various different types of one-way clutches could be employed in lieu of the wrap spring clutch that is depicted in the above examples. With reference to FIGS. 9 through 11 , a second clutch controlled decoupler constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10 b . The clutch controlled decoupler 10 b is generally similar to the clutch controlled decoupler 10 of FIG. 2 except that a roller clutch is substituted for the wrap spring clutch that is employed in the above-described example. The roller clutch 500 can include a hub 502 , a cage 504 , a plurality of cylindrical rollers 506 , a shaft 508 , an armature 510 , a friction liner 512 and a coil assembly 50 b that can be fixedly and non-rotatably coupled to the structure of an engine structure, such as an engine cover (not shown). The hub 502 can be coupled for rotation with the pulley 130 of the decoupler 30 b and can include a plurality of outer tracks or raceways 520 . Each outer track 520 can have a first track portion 522 and a second track portion 524 . The cage 504 can define a plurality of holders 526 , each of which being configured to receive an associated one of the rollers 506 . The shaft 508 can include a shaft portion 530 and a flange 532 . The shaft portion 530 can be non-rotatably coupled to the crankshaft (not shown) of an engine (not shown), while the flange 532 can be coupled to the cage 504 in a manner that permits limited rotational movement of the cage 504 relative to the flange 532 . In the particular example provided, the cage 504 includes a plurality of legs 534 that extend through slotted apertures 536 formed through the flange 532 . A thrust bearing 538 can be received between the flange 532 and the hub 502 . The rollers 506 can be received in the holders 526 and can engage the outer tracks 520 and the shaft portion 530 . Rotation of the cage 504 relative to the hub 502 can move the rollers 506 between the first and second track portions 522 and 524 . When the rollers 506 are in the first track portions 522 , the rollers 506 permit relative rotation between the shaft portion 550 and the hub 502 . When the rollers 506 are in the second track portions 524 , the rollers 506 are wedged between the hub 502 and the shaft portion 530 to thereby inhibit relative rotation between the hub 502 and the shaft portion 530 .
The friction liner 512 can be an annular structure that can be fixedly and non-rotatably coupled to the legs 534 of the cage 504 . The friction liner 512 can be slidably received on the shaft portion 530 between the armature 510 and the flange 532 . The armature 510 can be axially slidably but non-rotatably mounted on the coil assembly 50 b . The armature 510 can be moved in an axial direction by operation of the coil assembly 50 b . In the particular example provided, the coil assembly 50 b can be operated to drive the armature 510 away from the coil assembly 50 b and to frictionally engage the friction liner 512 to the legs 534 to create a drag force that can cause the cage 504 to rotate relative to the hub 502 so that the rollers 506 are moved from the first track portion 522 to the second track portion 524 . It will be appreciated that the friction liner 512 could be biased by a spring (not shown), such as a leaf spring, into or out of engagement with the legs 534 .
It will be appreciated that the above description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims.
Listing of Elements
clutch controlled decoupler
10
clutch controlled decoupler
10a
clutch controlled decoupler
10b
engine accessory drive
12
engine accessory drive
12a
engine
14
engine
14a
water pump
16
air conditioning compressor
18
starter/generator
20
crankshaft
22
belt
24
decoupler
30
decoupler
30a
decoupler
30b
clutching unit
32
clutching unit
32a
clutching unit
32b
actuator
40
actuator
40a
clutch assembly
42
clutch assembly
42a
coil assembly
50
coil assembly
50a
coil assembly
50b
armature
52
armature
52a
shaft member
60
output member
60a
input member
60b
hub
62
input member
62a
clutch element
64
clutch element
64a
coil mount
70
coil mount
70a
coil
72
coil
72a
annular flange
76
spacer ramp
76a
coil housing
78
coil housing
78a
front cover
80
front hub
82
pole member
90
pole member
90a
input flange
92
input flange
92a
spacing member
94
hub spacer
100
annular flange
102
annular wall member
104
torsional vibration damper
106
holes
110
first bearing element
116
mounting flange
120
output flange
122
flange
122a
coupling member
124
pulley
130
pulley
130a
pulley
130b
wrap spring
140
wrap spring
140a
first end
142
first end
142a
second end
144
second end
144a
wire coils
146
wire coils
146a
clutch surface
150
clutch surface
150a
carrier
160
carrier
160a
thrust ring
164
thrust ring
164a
aperture
170
aperture
170a
axial end face
180
axial end face
180a
face
182
lug
184
retaining ring
190
first spacer portion
200
first spacer portion
200a
second spacer portion
202
second spacer portion
202a
spacer ramp
206
bushing
210
friction material
250
friction material
250a
housing
310
bore
312
shaft
316
legs
330
annular groove
340
belt grooves
342
torsion spring
350
clutch spring
352
hub
354
spring carrier
356
apertures
360
driver tabs
370
annular body
372
input tab
380
bushing
390
roller clutch
500
hub
502
cage
504
rollers
506
shaft
508
armature
510
friction liner
512
outer tracks
520
first track portion
522
second track portion
524
holders
526
shaft portion
530
flange
532
legs
534
slotted apertures
536
thrust bearing
538 | A clutched device that includes a pulley, a shaft member, a first one-way clutch having a first wrap spring, and an actuator having an electromagnetic coil and an armature. The first one-way clutch rotationally couples the pulley and the shaft member when the actuator is actuated and rotary power is transmitted from a first one of the pulley and the shaft member to the other one of the pulley and the shaft member in a first rotational direction. A frictional force is applied to the armature when the actuator is activated. The frictional force is configured to resist rotation of the armature to cause the first wrap spring to radially expand into driving engagement with a clutch surface that is coupled to the pulley for common rotation. | 5 |
BACKGROUND OF THE INVENTION
The invention concerns a waterless toilet with a seat for use with a container that accommodates the waste, that can be closed, that has a rim resting against the seat while the toilet is in use, and that can be removed from the seat, closed, and deposited once the toilet has been used.
A waterless toilet of this type is known from the U.S. Pat. No. 3 495 278. The container is a flexible bag. The seat has a mechanism that rotates, once the toilet has been used, in relation to the bowl, which constitutes an outer container, twisting and accordingly sealing the bag with the waste inside it. The twisted-shut bag can be lifted out and conveyed to a disposal site.
The user must accordingly carry out certain manipulations in the vicinity of the seat as well as lifting the bag out and removing it. One drawback is that when the toilet is employed in a public area (aircraft, camp, bus, etc.) it is impossible to ensure that every user will carry out all the steps necessary to leave the toilet clean.
A container for waste from severely sick patients is known from the German Patent Publication No. A 468 1100. A replaceable sack covers the inner surface of the container. The open sack of waste drops into a receptacle through a trap and is later removed to a pit, tank, or similar structure. The drawback is that the sack of waste remains open in the receptacle, which accordingly gets dirty and must be cleaned. A powerful odor can also be expected to pervade the vicinity of the receptacle, and removing the waste is a particularly unpleasant task.
Known from the German Utility Model Patent No. U 7 205 756 is a container especially intended for use as a chemical toilet. The container has a removable lid that seals odors in tight while it is not being used. After use the container must be cleaned like a conventional toilet. After the container has been used only once, the lid, which opens easily, can be opened inadvertently or by the expanding gases that accompany the disintegration of such waste. This container is accordingly not a hygienic solution to the problem.
Another toilet is known from the German Utility Model Patent No. U 7 103 988. This toilet has a seat with a pitlike chamber under it. The chamber is heat insulated and communicates with a refrigerating system. When the waste drops into the pit, it freezes. The inner surface of the pit is lined with a bag. The bag is extracted with the deep-frozen waste inside it and removed before it can thaw. The drawback to this device is that waste leaves the body at 36°, which represents a lot of heat to dissipate, so that a lot of power is needed to freeze it. An expensive freezer with a loud motor for its compressor, however, is not welcome at camp sites. Furthermore, the problem of where to deposit the waste still remains.
SUMMARY OF THE INVENTION
The principal object of the present invention is accordingly to eliminate the drawbacks characteristic of the prior art and to provide a waterless toilet that will ensure smooth and hygienic operation and make the users' and maintenance personnel's experience with it as minimally unpleasant as possible.
This object, as well as other objects which will become apparent in the discussion that follows, are achieved, in accordance with the invention in a waterless toilet of the aforesaid type, by snap-in components distributed around its rim and by a lid that covers the container after it has been used. The lid also has snap-in components that fit tightly into the snap-in components on the rim, sealing the container hermetically and allowing someone to lift it out by grasping the lid. The container will preferably remain sealed until it is finally buried or burned, and accidental opening or bursting as the result of expanding gas will in principle be eliminated.
It is preferable for the lid to be made from a relatively rigid material, so that the container suspended from it need not be touched. It is preferable for the lid to have at least one handle.
The edge of the lid can wrap around the edge of the container or fit inside it to hermetically seal the container. The container is preferably made of flexible plastic, especially plastic sheet. Its rim and lid, on the other hand, are made from a relatively rigid material, allowing the aforesaid sealing procedures to be carried out unexceptionably.
The base of the toilet is preferably in the shape of a stool with a depression that can be accessed from above. It is at least to some extent surrounded by a seat, into which the container can be inserted.
To facilitate applying the lid there is a supporting structure at the bottom of the depression for the container to rest on. The supporting structure can preferably be raised and lowered.
Another practical feature is that the supporting structure can be exploited to compact the container so that the container is reducible in size before the lid is applied. The rising supporting structure forces the rim of the container against the lid while the seat rests against it and presses the snap-in components together.
The invention will now be described in detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of one embodiment of a waterless toilet with the lid up.
FIG. 2 is a side view of the toilet in FIG. 1 with the lid down and sealed.
FIG. 3 is a cross-sectional view, taken along the line A-B in FIG. 1.
FIG. 4 is a cross-sectional front view of the toilet illustrated in FIG. 1.
FIGS. 5 and 6 are views similar to those in FIGS. 1 and 2, respectively, but for another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The waterless toilet illustrated in FIGS. 1 through 4 has a base 1 in the form of a stool with a bell-shaped cross-section. The inside 2 of the base is accessible from above and accommodates a supporting structure 3 about halfway up. Resting on the structure is a cylindrical sheet-steel tank 4 with a steel bottom 5. The tank is open at the top, where it is surrounded by a projecting edge 6. Below the bottom 5 of the tank 4 is a star-shaped support 7. Support 7 is part of the structure 3. It engages the bottom 5 and can lift it. Support 7 terminates at its lower end in a bead comb 8, which is accommodated in a groove 9a in a supporting roller 9 (cf. FIG. 4). Roller 9 is at the end of a lever 10 that pivots in a shaft 11. The ends of the shaft rest in projecting shoulder 12a and 12b at the bottom 1b of the base.
Lever 10 is activated by a pedal 13 and travels approximately 30°. Depressing the pedal raises roller 9 into the upper position represented by the broken lines in FIG. 1 and hence lifts support 7 and tank 4. Also suspended in support 7 are two helical springs 18 and 19 that are secured by a pin 20 or bore in the opposite end of lever 10. The springs generate a force opposing the upward motion that lowers supporting structure 3 along with tank 4 and a container 15 when pedal 13 is released.
A plastic container 15 is suspended in tank 4. The container has a capacity of approximately 5 liters. It consists of a body 15a and of a rim 16 that is secured to the upper edge of the body. Rim 16 is in the form of a bead 17 that is folded down and out and is round at the top. Its cross-section is more or less in the form of an upside-down J. Rim 16 is made for example from a polyethylene torus about 3 to 5 mm thick. The body 15a of the container is made of polyethylene sheet about 1 mm thick. The body is welded to the rim. As will be evident from the figure, the edge 6 of tank 4 supports rim 16 from below. The suspended container 15 can also be lifted to some extent.
Base 1 ends at the top in an edge 1a. A toilet eat 22 rests on the edge. The seat is more or less in the form of a circular ring open at the bottom. It is dimensioned to allow the bead 17 on container 15 to rest against its inner surface. The result is similar to a conventional toilet seat. Seat 22 is secured to base 1 and can be released from it by threaded fittings 23. The fittings have a projection that engages a groove 21 in edge 1a.
A toilet lid 25 is hinged to the left side of edge 1a in FIG. 1. Toilet lid 25 simultaneously functions as a holder for container lids 26. Container lid 26 is also made of relatively rigid polyethylene and has grooves 27 at the edge for bead 17 to snap into. Container lid 26 also has a handle, which lies narrow in the illustrated state and is accordingly not represented. At the front edge of the toilet lid is a locking bar 29.
As toilet lid 25 pivots down in the direction indicated by broken line D, locking bar 29, which is mounted subject to spring tension against toilet lid 25, advances beyond the outer edge of a fitting 23 and locks under its projection 23a. It can be forced out again to allow it to pivot out. As long as the toilet lid 25 is down, container lid 26 will rest against container 15 with snap-in components 17 and 27 in immediate contact but not snapped together. Once the toilet has been used, the loaded container 15 will be sealed tight by holding down seat 22 and activating pedal 13, which raises supporting structure 3 and forces bead 17 into the matching groove 27 in container lid 26. The result is a hermetic seal strong enough to allow the container, even one weighing as much as 7 kg, to be lifted out by the handle.
It will be evident from the foregoing description that it is possible to employ an inner lid instead of a beaded lid. The inner lid will fit into an appropriately designed rim, one with supporting surfaces and snap-in components in the form of snap-in projections inside the circumference of the container for example. It is required only that the container lid 26 have means for firmly gripping and sealing the rim 16 of the container 15. The container can either be relatively flexible or relatively rigid and non-collapsing. The decision primarily depends on costs. The most appropriate materials are waterproof plastics, but coated paper and similar disposable materials can also be employed.
FIGS. 5 and 6 illustrate another preferred embodiment of the invention. This version features supporting structure in the form of a lever-type adjustment 13, one end of which is connected to a rod 43 secured in a sleeve 42. At the other end of the rod two disks 44 and 45 are separately and concentrically mounted on the rod. The upper disk, which terminates the head of the rod has a smaller diameter, and the lower disk 44 has a larger diameter. A high-quality steel tank 46, which extends down to a flange-like annular edge 48 with a large central opening 49 rests on a projection 1' of the housing 1. The diameter of upper disk 45 is smaller and that of lower disk 44 is larger than the diameter of opening 49. Inside the tank 47 is a flower-pot shaped rubber membrane 50 that completely occupies the inside of the pot and covers opening 49 with its base 50'. The membrane is sufficiently resistant to deformation in the vicinity of opening 49 to ensure that the (rubber-lined) tank 47 will be tightly spanned, whether empty or full, meaning that the membrane will hardly sag at that point.
The membrane 50 is supported in this area by small upper disk 45. Suspended inside the rubber-lined tank, as described with reference to the first embodiment, is the container, which is a bag in the conventional sense, with its rigid lid edge.
Once the toilet has been used, the toilet lid 25 is lowered and snapped into place as previously described herein. Pressing down on pedal 13 displaces lever 41 and forces rod 43 up. Smaller disk 45, if it has not already done so, comes into secure contact with rubber bottom 50' in the vicinity of opening 49 and forces it, and hence the tank 47 up until it comes into contact with the container lid 26 in toilet lid 25. Subsequent to this phase, the lid is folded in around the smaller disk 45 until the larger disk 44 comes into contact with the annular edge 48 around the tank 47 and hence terminates the motion of rod 43 in relation to the tank 47. As the force increases, accordingly, the edge of the bag is forced into the matching component on the lid and the bag (container 15) and lid 26 will snap together. This procedure is preceded by a reduction in the volume of the container 15 in that upper disk 44 travels through the limited opening 49, accompanied by deformation of membrane 50, until lower disk 45 comes into contact with edge 48 from below.
This approach represents one way of reducing the volume of the suspended container 15 before the lid is forced into position. The same technical variant can be accomplished with similar stacking mechanisms. Another advantage of compacting the container is that any gas that forms as the waste rots will only fill up the bag without bursting it.
There has thus been shown and described a novel waterless toilet with container with lids for waste which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. | A waterless toilet with a seat for use with a container (15) that accommodates the waste, that can be closed, that has a rim resting against the seat while the toilet is in use, and that can be removed from the seat, closed, and deposited once the toilet has been used. The toilet has snap-in components (17) distributed around its rim and a lid (26) that covers the container after it has been used. The lid has snap-in components (27) that fit tight into the snap-in components on the rim, sealing the container hermetically and allowing someone to lift it out by grasping the lid. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of Swiss patent application 0531/10, filed Apr. 13, 2010 and PCT Application No. PCT/CH2011/000071, filed on Apr. 4, 2011, the disclosures of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The invention is related to an arrangement for forming a band loop between a delivery spool which is actuated in an uncoiling manner and a band drawing-in device. Particularly, the arrangement is used for a method to produce peel-off lids, comprising the forming of a plurality of parallel rows of lid rings made of metal, wherein a stepwise transport of the lid parts to a plurality of processing stations and a stepwise delivery of a foil band from a delivery spool to the lid rings and the stamping out of foil sections as well as the appliance and heat sealing of the foil sections onto the lid rings in a stamping and sealing processing station are carried out, wherein a foil band loop, which comes to lie between the foil band spool and the drawing-in of the foil band into the stamping and sealing processing station, is formed in the foil band by means of the arrangement. Furthermore, the invention is related to a device for manufacturing peel-off lids with an arrangement according to the invention.
BACKGROUND
[0003] It is known how to execute lids for can-like or tin-like packaging as metal lids permanently attached on the top of the packaging, having an extraction opening remains closed until the first usage of the packaging contents by means of a peelable foil attached by heat sealing, particularly a metal foil. An additional lid made of plastic and arranged on top of the metal lid makes it possible to close again the packaging during the consumption period of the contents. Devices for manufacturing such metal lids will be explainer in the following in more detail by means of FIG. 5 . FIGS. 6 to 12 serve to explain manufacturing steps during the production of such lids. The peelable foil is drawn off a band delivery spool as a wide foil web and is inserted into the stamping and sealing stations or it is guided over the lid parts respectively. In order to provide a band delivery for the drawing-in of the foil band into the stamping and heat sealing processing station, one or more so-called dancer roll systems are used, which may however result in problems regarding the stepwise foil transport in the presence of high manufacturing cadences, particularly also in case of thin foil bands. Band loops of the ordinary type are generated by the controller of the actuator of the uncoiling delivery spool and are regulated by e.g. a distance sensor which measures the distance from the stationary sensor. For strongly changing drawing-in lengths in the presence of a high band speed, this is complex with respect to the actuation or it yields insufficient results. In DE-A 40 02 194 the forming of a band loop by means of an air current is proposed.
[0004] It is the objective of the invention to provide an arrangement by means of which a band loop can be provided in a simple way and which works in a reliable way in the presence of high manufacturing cadences with a stepwise band transport and in case of the most different foil materials.
[0005] This objective is reached by the present invention.
SUMMARY OF THE INVENTION
[0006] It has been noticed that, by the hollow cylinder which is freely movable within certain limits, which consequently lies loose on the band for some time and forms the lower deflection of the band loop, a stable band loop is reached even under said conditions. In this way also plastic foils or laminate foils or aluminium foils with band speeds of 60 meters/minute and drawing-in lifts of 50 to 150 millimeters per lift can be handled very well, thus enabling the usage of the arrangement during the manufacturing of peel-off lids with high cadence.
[0007] Preferably, a transversal bar lying horizontally and supported on both sides in the side walls runs through the hollow cylinder and limits the free mobility of the hollow cylinder. This results in a particularly easy path limitation for the hollow cylinder. Furthermore it is preferred that the transversal bar is arranged in a vertically shiftable way in a vertical groove guidance in the side walls in order to limit the mobility of the hollow cylinder in vertical direction. The diameter and also the material of the hollow cylinder can be differently chosen. The diameter can be chosen to be e.g. 20 cm or larger. Particularly plastic is a suitable material.
[0008] Furthermore, the invention has the objective to provide a method and a device for manufacturing peel-off lids, in case of which the advantageous arrangement for reaching a band loop is used. This is accomplished by the method or the device of the present invention respectively.
[0009] The foil band is preferably supplied to the stamping and sealing processing station with partially unequal step lengths in a horizontal way and, as seen horizontally and from the top, with its longitudinal direction substantially perpendicular to the transport direction of the lid parts.
[0010] By delivering the foil web in a right angle it is possible, contrary to the ordinary oblique delivering, to save around 20% of the foil. However, the straight delivering results in a strong fluctuation of the step length of the foil band delivering in case of more than two parallel manufactured rows of lids. The stabilizing of the foil band loop by means of the arrangement makes it possible to handle the foil or large step lengths fluctuations respectively, equally in the presence of high delivering speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further embodiments of the invention and the manufacturing of peel-off lids are described in more detail by means of the following figures.
[0012] FIG. 1 a schematic side view of an embodiment of an arrangement according to the invention in operation between a delivery spool and a band drawing-in;
[0013] FIG. 2 the arrangement of FIG. 1 with the hollow cylinder lifted from the band;
[0014] FIG. 3 the arrangement according to FIG. 1 in a perspective view;
[0015] FIG. 4 a side view of the arrangement with another position of the hollow cylinder;
[0016] FIG. 5 a schematic side view of a known device for transporting and manufacturing peel-off lids; and
[0017] FIG. 6 to FIG. 12 sectors of metal lids for explaining the manufacturing of the lids.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIGS. 1 to 4 show an embodiment of an arrangement 1 according to the invention. It is provided and adapted to form a band loop 7 in a band 6 . The band 6 is uncoiled from a band delivery spool 2 in an actuated manner and thereafter gets into the arrangement 1 . Thereafter, the band is transported by a drawing-in device 4 which belongs to a device inside which the band is used or processed respectively. An example of such a device is explained in the following. The shown band transport reveals the band transport direction D. The uncoiling from the band delivery spool is normally done with constant speed or it may be adjusted to fast speed changes of the drawing-in device 4 via the actuator 19 only comparatively slowly. Particularly, the drawing-in device 4 can cause a stepwise drawing-in of the band with changing drawing-in lengths. Thereby, the arrangement 1 has the purpose to compensate for the drawing-in fluctuations with respect to speed and/or drawing-in step lengths by means of the band loop 7 , in such a way that the loop forms a band material stock which can easily be drawn in. This is basically known.
[0019] An actuator 19 which is not shown in detail is provided, being e.g. formed by an electric motor. The skilled person knows such actuators, such that no further description thereof has to be specified. The actuation 19 can be done by controlling the device with the drawing-in device 4 , in order to adjust the band uncoiling to the band demand. A sensor 19 ′, particularly as a distance sensor, can also be provided, by means of which the actuator 19 can react to the length increase or the length decrease of the loop respectively. The sensor signals can be passed to the controller of the device and be processed there for the controlling of the actuator 19 or they may be passed to a controller which is directly attributed to the actuator, in order to supplement the controller signals from the device. The arrangement 1 has two side walls 8 and 9 which consist e.g. of plastic or metal. The band runs between these side walls and forms the loop 7 there. A hollow cylinder 10 is provided, which lies on the band and forms its deflection and therefore facilitates the loop forming and consequently determines the uncoiling reserve. The diameter of the hollow cylinder can be chosen differently. The hollow cylinder may e.g. consist of plastic, particularly polymethylacrylate (Abbreviation PMMA, common speech acrylic glass). Also, a material with a higher specific weight can be chosen in order to reach a higher pre-tension, e.g. aluminium. The hollow cylinder preferably has the shown round cross section, it could however also have an oval or polygon cross section. The hollow cylinder is substantially aligned with its end faces between the side walls, such that it can move freely between the side walls without jamming. The hollow cylinder is free in its movement to a limited extent, such that it can move freely by a certain amount in the band travel direction and perpendicular thereto. This amount depends on the diameter and on the uncoiling. The limitation of the movement can be limited by arbitrary means acting upon the hollow cylinder. Preferably, it is acted upon the hollow cylinder from the inside and particularly by means of a transversal bar 11 which is arranged lying horizontally between the side walls and extends throughout the hollow cylinder. The transversal bar 11 can be arranged in a fixed way in the side walls or it can be guided therein preferably in a vertically slidable way. For this, the shown vertical groove guidances 12 , 12 ′ may be provided.
[0020] In FIGS. 1 and 3 the hollow cylinder 10 is shown in its vertically lowermost position. Thereby, it lies with its inner wall on the transversal bar 11 which itself lies lowermost in the groove guidances. Now, if the drawing-in device 4 pulls more band than uncoiled by the delivery spool in an actuated way, the band loop is shortened, resulting in a deflection of the hollow cylinder from the shown lowermost position. Thereby it is free with respect to its movement between the side walls. It has been noticed that even very thin and light foil bands can be handled very well as loops by means of such a freely movable hollow cylinder which, consequently, within the limits of the free movement, lies on the band only with its weight (which can be adjusted by the diameter and/or material choice of the hollow cylinder) and forms its deflection and causes the pre-tension of the band. The free movement of the hollow cylinder through the band is however limited, in the shown example by the transversal bar 11 . If the way length of the free movement is used up (which in this case results by the inner diameter of the hollow cylinder) the hollow cylinder first contacts the transversal bar 11 in this embodiment, such that its free movement upwards is used up and is reduced also sideways. This position is shown in FIG. 3 . Further, if more band is drawn in than uncoiled, the hollow cylinder pulls the transversal bar upwards. This is well illustrated in FIG. 4 . There, a position is shown, in which more band has been drawn in by the drawing-in device during a certain time period than it has been supplied by the band delivery spool, such that the loop 7 has been shortened to such an extent that the hollow cylinder 10 has been pushed upwards and has also moved the transversal bar 11 upwards in its groove guidances 12 , 12 ′. The upper end of the groove guidances 12 , 12 ′ would also limit this upward movement. If thereafter the drawing-in device draws less band than supplied by the delivery spool, or if the actuation of the delivery spool is adjusted in a controlled or regulated way in such a way that more band per time unit is uncoiled, the loop 7 extends again and the hollow cylinder lying on the band moves downwards again, maximally in the position of FIGS. 1 and 2 . A further extension of the loop should be avoided by the controller of the actuator of the delivery spool 2 , because the band or the loop 7 respectively, should not run through the arrangement 1 without the stabilizing effect of the hollow cylinder.
[0021] In the shown embodiments the arrangement has an upper drawing-in-sided band deflector 14 and an upper exit-sided band deflector 15 . The band deflectors are arranged at the upper side of the side walls. The deflectors can be rolls which rotate with the band. However, also non-rotating deflectors may be provided. Adjustable lateral limiters are preferably provided for the band, such that the latter runs in a defined position above the band deflectors 14 , 15 . For this, axially shiftable and fixable thrust washers 14 ′ and 14 ″ are provided on the band deflector 14 and 15 ′ and 15 ″ on the respective band deflector 14 or 15 in the shown embodiment. These thrust washers are adjusted, after releasing their attachment, in their distance with respect to the width of the band, such that they form lateral limiters for the band.
[0022] Alternatively to the shown band guidance via the drawing-in-sided deflector 14 of the arrangement 1 the band can also be guided on the drawing-in-side above a deflector 16 ( FIG. 3 ), such that the band runs from the delivery roll 2 under the deflector roll 16 and to the hollow cylinder 10 . The arrangement 1 is preferably attached to the supports 5 or 3 respectively, for the delivery spool 2 , by means of adjustable attachment means 17 , 18 . The adjustability makes it possible to adjust the distance of the arrangement 1 , in horizontal direction, from the supports 5 , 3 . Now, the preferred use of the arrangement when manufacturing the peel-off lids is described. Thereby, the band which is present on the band delivery spool 2 is the peel-off foil material out of which the peel-off foil is punched out for each lid. Processing stations and manufacturing steps for manufacturing metal lids with peel-off foils according to the state of the art will be explained using FIGS. 5 to 12 . Thereby, FIG. 5 shows a schematic side view of a known device 21 which has a plurality of processing stations 23 to 28 as well as a further station 29 on a machine frame 22 . A transport device for the lid parts is a linear transport device according to a preferred embodiment, as known from WO2006/042426. This linear transport device is adapted to transport lid-shaped objects of the type described in the following by means of toothed belts and it is suitable for a very fast transport or lid production respectively. Opposed tappets for the lid parts are provided at the mutually opposed and synchronously moved toothed belts. The transport device serves to transport in cycles the lid parts or the lids respectively, to the individual processing stations, as explained in the following. The transport device shown in FIG. 5 transports the lid parts or the finished lids with peel-off foils in a transport direction which is indicated by the arrow C, from the input of the device at the stack 31 to the output of the device where the lids get into the trays 36 or 37 via slides. Lid parts are destacked from the stack 31 in a known way and they get into the transport device. The shown transport device has another construction than the preferred linear transport device of WO2006/042426 and is only shortly described here. Two long bars, each of which is arranged at the side of the lid parts or lids respectively, are provided, which lift up the lid parts or lids respectively, lying on trays or in the stations 23 to 29 , during their own lift up, by means of the actuator, in the direction of arrow A and subsequently shift them onwards by an amount in a forward motion in the direction of arrow B (in the same direction as arrow C) by means of the crank drive. Thereafter, the bars are moved downwards in the direction of arrow A, wherein the lid parts or the lids respectively are again placed onto their lay-down position. Thereafter, the bars are moved backwards below the object lay-down positions in the direction of arrow B and anti-parallel to arrow C, whereafter the described process is repeated. Between transportations, the lid parts or the lids respectively lie on their lay-down positions or are located in the processing stations respectively and are processed there. A recurring conveying takes place after a processing step through all processing stations. FIG. 6 shows stacked metal lid blanks 120 as an example for lid parts, the way they are provided in the stack 31 . These blanks 120 are for example round metal disks with a diameter of e.g. 11 cm. Evidently, other basic shapes like for example square or rectangular disks and other diameters are readily possible. The blanks 120 have already been preformed at their edge, as shown in FIG. 5 , in a processing machine which is not shown. In FIG. 6 and in the subsequent figures only a sector of the whole disk is shown in order to simplify the figures. In the first processing station 23 of FIG. 5 , an opening 129 is stamped into the disk by means of a stamping process with an upper and a lower tool, this being shown in FIG. 7 , where the edge of the opening is denoted by 121 and the stamped out round disk by 127 . This disk is disposed of as debris. The stamp processing station 23 is actuated—as it is the case for the additional processing stations—by means of an actuator 115 . A pulling down of the edge 121 takes place in the processing station 24 , by means of which for example the shape 122 of the edge, shown in FIG. 8 , is reached. The ring-shaped lid parts 120 then reach the stamping and sealing station 25 , where the peel-off foil 125 is placed above the opening of the lid 120 and attached there by means of heat sealing, this being shown in FIGS. 9 and 10 . The peel-off foil 125 is preferably a laminated foil or it is an aluminium foil and it has in a known way a plastic layer on the bottom side. The required precut foil 125 is stamped out of a wide foil web in the station 25 and placed above the middle cavity of the ring shaped disk and is pressed by the sealing station at the edge of the round cavity of the part 120 under the influence of heat, such that the foil 125 is sealed tightly to the metal lid 120 by melting and subsequent cooling the plastic layer. This is known and will therefore not be explained in more detail. It may also be provided that the peel-off foil is only pre-sealed in the stamping and sealing station 25 and is thereafter sealed in an additional heat sealing station. A cooling process station 27 may possibly be provided for the cooling. The foil 125 may be provided with a stamp 124 ( FIG. 11 ) in a processing station 28 and then the edge 122 is subsequently flanged to yield the finished edge 123 . The finished lids are submitted to an inspection in an inspection station 29 comprising a leak test, which is described in the following for the peel-off foil 25 which is applied on the lid. If the foil is tightly attached to the rest of the metal lid, the lid ends up in the tray for the finished lids. If a leak is detected, the lid ends up in the waste container via the other shown slide.
[0023] By means of the mentioned linear transport device lid parts or lids respectively, can be transported with a high cadence of e.g. 200 objects per minute and with reproducible partial steps between the stations. Furthermore, a flexible concept for the large format range of the objects or the lids respectively, which can range for e.g. round lids from a diameter of 40 to 200 mm and which can also receive different rectangular formats, e.g. for ordinary fish cans. The transport device is furthermore, as a compact module, particularly designed for the multiple track configuration. In combination with such a production of lids with a high cadence, the arrangement for forming the band loop can be used in a particularly advantageous way. It can however also be used for other devices where a band loop has to be generated.
[0024] A foil band loop is generated when handling a foil band to be uncoiled from a delivery spool, which is stepwise drawn into a drawing-in device. In order for this to take place in an error-free way in case of high manufacturing cadences, an arrangement is provided, in case of which a hollow cylinder for forming the band loop lies loosely on the band with limited mobility. Such an arrangement is preferably provided for manufacturing peel-off lids, in case of which a foil band is uncoiled from a band delivery spool and is provided to a stamping and sealing station. | When handling a foil band ( 6 ) which is to be uncoiled from a delivery spool ( 2 ) and is drawn in gradually by a drawing-in device ( 4 ), a foil band loop ( 7 ) is produced. In order that this can take place without any errors with high production cadences, provision is made of an arrangement ( 1 ) in which a hollow cylinder ( 10 ) rests loosely on the band with a limited freedom of movement so as to form the band loop. Such an arrangement is preferably provided for the production of peel-off lids, in which a foil band is uncoiled from a band delivery spool and fed to a stamping and sealing station. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved method for the manufacture of the construction material known as "waferboard" or "chipboard" and, more particularly, an improved process for applying release agent to a mass of wood material and binder to facilitate release of the mass from a platen used to compress it during the manufacture of chipboard.
2. Description of the Related Art
Chipboard is a substitute for common plywood. It is manufactured by compressing "chips" or small broken-up pieces of wood material and binder into flat sheets suitable for use in construction. The chips may also be compressed into other shapes useful in construction and other applications. In the manufacture of chipboard, trees are "chipped" or mechanically broken-up into small pieces approximately 1-3 inches in length by 1/4-1 inch in width by 1/32-1/16 inch in thickness. The chips are then mixed with a binder or glue, such as diphenyl methyl diisocyanurate (MDI). A specific volume of chips mixed with MDI is placed on a press where heated, top and bottom platens compress the mass into boards of various dimensions. Both platens are conventionally sprayed with a release agent which prevents the mass of chips and binder from adhering to the hot platens during the compression of the chips and binder. See for example U.S. Pat. Nos. 4,532,096 and 4,374,791.
Spraying the release agent upon the platen, however, is disadvantageous. Aerosolized release agents are sprayed into the atmosphere, thus increasing pollution and possible adverse effects on workers. Moreover, spraying the release agent is not an efficient mode of applying the agent. Significant amounts of the release agent are lost into areas other than the interface of the wafers and the platen.
Numerous other methods of applying release agent are also known. Release agent has been brushed onto the top surface of wood material and binder prior to the step of hot pressing (U.S. Pat. No. 4,201,802). It has been found that utilizing a metallic surface including magnesium and zinc for the platen enhances release of the wood material and binder therefrom (U.S. Pat. No. 4,428,897). Binders having a self-release effect (U.S. Pat. No. 4,528,153) or incorporating an internal release agent are also known (U.S. Pat. Nos. 4,528,153, 4,376,089, 4,528,154, 4,257,995, 4,257,996, 4,376,088 and 4,258,169). See also U.S. Pat. No. 4,110,397 which teaches providing a metallic soap at the interface between the mold and the mass of wood material and binder to assist release.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new method for applying release agent to a mass of wood material and binder during the production of chipboard, the method avoiding the disadvantages associated with spraying the release agent on the mold, in particular, the aerosolizing of release agent.
Another object of the invention is to provide complete and uniform coverage of the wood material and binder with release agent while reducing the levels of release agent required.
These objectives, and other objectives, are achieved by the method of the present invention wherein an aqueous solution of release agent and foaming agent is pressurized and a predetermined amount of pressurized aqueous solution is metered to a foamer. The aqueous solution is foamed in the foamer, preferably using compressed air or a pump, to form a coherent, continuously uniform, finely bubbled foam containing the release agent. The foam is dispersed onto a mass of wood material and binder, leaving release agent on the mass to enhance release of the mass from the platen after hot compression of the mass.
The aqueous solution may be pressurized using a predetermined amount of compressed air or a pump. Preferably, a continuous blanket of the foam is dispersed on the mass by forming individual streams of the foam on the mass and merging the individual streams to form the continuous blanket.
The above summarized method may be utilized as part of a total method for manufacturing chipboard, including in addition to the above steps, the steps of compressing the mass and cutting the compressed mass into any desired shape and size to form the chipboard.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram generally illustrating the method of the invention;
FIG. 2 shows a dispenser box element utilized to apply foamed release agent onto the mass of wood material and binder in accordance with the invention; and
FIG. 3 is an end view of the dispenser box element taken along lines 3--3 in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Chipboard in accordance with the invention is prepared by hot pressing a mass of wood chips, wood fibers or other lignocellulose material (herein referred to collectively as "wood material") and a binder. Any suitable wood material and binder may be employed, such as those taught by U.S. Pat. No. 4,110,397 to Wooer, the disclosure of which is herein incorporated by reference. In general, the wood material may be shavings, wood wool, cork, bark, sawdust and the like waste products from the woodworking industry, and/or fibers from other natural products which are lignocellulosic, for example, bagasse, straw, flax residues, and dried rushes, reeds and grasses. Nut shells, for example ground nuts, and hulls from cereal crops, for example rice and oats, are also included. Additives such as flakes and fibrous material (e.g., glass fiber, mica and asbestos) and synthetic products (e.g., rubbers and plastics) may also be included. Other wood material and additives will be apparent to one skilled in the art.
The binder may be any suitable binder, such as formaldehyde resins (usually urea-formaldehyde, melamine-formaldehyde or phenol-formaldehyde) or an isocyanate-based binding agent. The isocyanate-based binder is generally preferred in the field and may be any suitable organic polyisocyanate either alone or in admixture with another type of binder, for example, a synthetic resin glue. The binder may be liquid, such as a solution of the binder in an inert solvent or an aqueous emulsion. Other binders will be apparent to one skilled in the art.
The release agent may be any suitable release agent, such as silicone oil, lecithin, carnauba wax, polytetrafluoroethylene, metal salts of long chain aliphatic or cycloaliphatic acids, carboxy-functional siloxanes and vegetable oil soap surface active agents. The release agent is preferably capable of foam expansion to 30 to 300 times its original volume. Other release agents will be apparent to one skilled in the art.
The wood materials, binders and release agents are all conventional and are all discussed in the patents mentioned in the above "Background of the Invention" section. The disclosures of all those patents are herein incorporated by reference. A preferred wood material, binder and release agent are: aspen or pine shavings; isocyanate binder, such as MDI; and metal salts of long chain aliphatic acids, such as potassium oleate.
The aqueous solution generally contains about 0.1 to 20%, preferably about 1 to 10% release agent, and about 0.1 to 20%, preferably about 1 to 10% foaming agent. All percentages expressed herein are weight percentages, unless otherwise specified. The release agent and the foaming agent may be the same substance. If one substance is used for both the release agent and foaming agent, the aqueous solution generally contains 0.1% to 20%, preferably 1 to 10% of the combined release and foaming agent. A preferred aqueous release agent composition is an aqueous solution of a metal salt of a long chain aliphatic acid, such as 20% by weight potassium oleate, the potassium oleate also functioning as a foaming agent. Vegetable oil soap also functions as both a release agent and foaming agent in accordance with the invention. Paraffin wax is a suitable release agent, but is non-foaming such that a foaming agent such as sodium lauryl sulfate must be used. Other non-foaming release agents suitable for use in the invention include montan wax and sodium stearate. Preferably, a single chemical substance is used as both the foaming agent and release agent for economic reasons.
The foaming agent, if included in the aqueous solution, may be any suitable foaming agent, such as sodium laureth sulfate (sodium lauryl ether sulfate) or alkyl polyglycosides. Other foaming agents will be apparent to one skilled in the art.
Referring now to the drawings wherein like numbers describe like elements, there is shown in FIG. 1 a system (in flow diagram form) in accordance with the principles of the invention and designated generally as 10. The system 10 includes a pressure pot or tank 20 into which an aqueous solution of release agent and foaming agent is placed. A pump (not shown) may be utilized in place of pressure pot 20. Compressed air is supplied from compressed air source 30 to force solution through line 40 to metering device 50. At the same time, additional compressed air from compressed air source 60 flows through line 70 to metering device 80. Solution from metering device 50 flows through line 90 to a packed column 100 and compressed air flows through line 110 to the packed column 100. The packings (not shown) may be any suitable high surface area to volume solid such as porcelain saddles used in distillation processes. Both metered fluids enter column 100 where they are contacted and foam is generated. Preferably, the foam incorporates all the compressed air from compressed air source 60. The column may be 1" in diameter by 2" long to 24" in diameter by 8' long, depending upon the output of foam required. Foam formed in column 100 flows through line 120 to dispersion device 130. The foam formed in column 100 is a coherent, continuously uniform foam formed of fine bubbles generally less than about 1 mm. in diameter. The foam has a specific gravity of about 0.033 to about 0.0033.
The above-described foaming apparatus is commercially available from the Mearl Corporation, 220 West Westfield Avenue, Roselle Park, N.J. 07204. Release agent is available from Surfactants Corporation, 260 Ryan Street, South Plainfield, N.J. 07080. In addition to this foaming apparatus, dispersion device 130 is provided. This device is constructed for use in the invention in combination with the conventional foamer described above.
Referring now to FIGS. 2 and 3, dispersion device 130 is a box for receiving the foam from line 120 and dispersing it onto mass 150 of wood material and binder passing on a conveyor 160 positioned beneath dispersion device 130. Dispersion device 130 includes several rows of closely spaced (approximately 1/4 inch apart from center to center) apertures 132 (shown in phantom in FIGS. 2 and 3), each aperture 132 having a diameter of about 1/16 inch. Foam from line 120 enters dispersion device 130 through apertures 134 and 142 located in side walls 135 and 143, respectively, of device 130 and apertures 136, 138 and 140 located in a top wall 137 of device 130. Foam is forced through apertures 132 into numerous individual streams that, soon after emerging from dispersion device 130, merge to form a single continuous foam blanket which deposits on mass 150. Subsequently, and not shown in the drawings, mass 150 is compressed in a platen or platens in a conventional manner to form the chipboard and then cut to any desired size to complete its manufacture.
During operation of system 10, the aqueous solution of release agent and foaming agent is pressurized in pressure pot 20 to a pressure of about 30 to about 200 psig, preferably about 60 to about 150 psig. The solution then flows through metering device 50 where the desired volume of solution is metered to flow through line 90 into packed column 100. At the same time, compressed air from compressed air source 60 is metered in metering device 80 so that the correct volume of air enters packed column 100. The pressure of these two fluid lines, solution and compressed air, are in the same range of about 30 to about 200 psig, preferably 60 to about 150 psig, and are generally about equal to each other. Solution and air temperature may range from about 32° F. to about 130° F., preferably 65° F. to about 90° F. The actual pressure used will depend on the volume of foam required. In general, the higher the pressure, the greater the foam volume. The foam flow rate will depend on the area and speed of the chipboard line. The foam flow rate may be between about 2 and about 200 ft 3 /min, preferably between about 25 and about 100 ft 3 /min. As foam emerges from packed column 100, its pressure is greatly reduced but is sufficient to enter the dispersion device 130 and apertures 132 located in the dispersion device 130. The pressure of the foam emerging from packed column 100 may vary from about 2 psi to about 50 psi, preferably from about 10 psi to about 40 psi, depending on the flow rate employed. The foam streams emerging from the apertures 132 fall by gravity and merge into a single blanket. This blanket falls on the moving bed of chips 150 and entirely covers the chips. The rate of foam production generally matches the volume of foam required to cover the chips as the belt moves.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | A method for applying release agent to wood material and binder used in the manufacture of chipboard. An aqueous solution of the release agent is foamed to form a coherent foam blanket that is applied to the wood material and binder. The foam leaves a coating of release agent on the wood material and binder that enhances release of a platen from the same. Foaming the release agent avoids deleterious aerosolization and increases the efficiency of applying the release agent. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a 35 U.S.C. §§371 national phase conversion of PCT/EP2015/069501, filed Aug. 26, 2015, which claims priority of European Patent Application No. 14185055.2, filed Sep. 17, 2014, the contents of which are incorporated by reference herein. The PCT International Application was published in the German language.
TECHNICAL FIELD
[0002] The present invention is directed to a method for rolling a metal strip in a finishing train, wherein the finishing train has multiple rolling stands, through which the metal strip passes in succession, and wherein the actual width and the actual temperature thereof is detected for each of the sections of the metal strip before they enter the finishing train.
[0003] The present invention is furthermore directed to a computer program, which comprises machine code, which is executable by a control unit for a finishing train, wherein the execution of the machine code by the control unit causes the machine unit to operate the finishing train according to such a method.
[0004] The present invention is furthermore directed to a control unit for a finishing train, wherein the control unit is programmed using such a computer program, so that the control unit operates the finishing train according to such a method.
[0005] The present invention is furthermore directed to a finishing train for rolling a metal strip, wherein the finishing train has multiple rolling stands through which the metal strip passes in succession, and wherein the finishing train has such a control unit, which operates the finishing train according to such a method.
TECHNICAL BACKGROUND
[0006] A hot rolling train for rolling metal strip generally consists of a roughing train, a finishing train, and a coiling device. The metal strip firstly passes through the roughing train and then the finishing train and is finally supplied to the coiling device. In many cases generally at least in hot strip trains for rolling steel strip, furthermore a cooling line is provided. If it is provided, the cooling line is arranged downstream of the finishing train and upstream of the coiling device.
[0007] Narrow width tolerances are often specified for the rolling of the metal strip. Maintaining these width tolerances is an important quality feature. Actively influencing the width of the metal strip therefore generates an economic utility.
[0008] The width of the metal strip is influenced both in the roughing train and also in the finishing train and also on the way to the coiling device. In some cases, this influencing is actively performed.
[0009] Thus, for example, a method is known from the technical article “Development of Automatic Width Control System for Hot Strip Finishing Mills” by M. Nakayama et al., Proceedings of the Third International Conference on Technology of Plasticity, Kyoto, Jul. 1/6, 1990, vol. II, pages 791 to 796, in which a width measurement is performed after multiple (but not all) rolling stands of the finishing train. Using all provided width measurements, the missing width measured values are estimated by means of a model. A compensation for width deviations is performed by the calculation and switching on of an additional strip tension for each loop lifter controller.
[0010] Performing a pilot control for the width deviations is known from the technical article “Automatische Breitenregelung in der Warmbandstraβe Borlänge der SSAB Tunnplat [automatic width regulation in the hot strip train Borlänge of SSAB Tunnplat]” by Harald Natusch et al., stahl and eisen 122 (2002), issue 11, pages 93 to 100. The width in the finishing train is ascertained in a manner supported by a model. A measurement of the width is performed before and after the roughing train and after the finishing train.
[0011] Disclosed in “Automatische Breitenregelung in der Warmbandstraβe Borlânge der SSAB Tunnplåt” by Harald Natusch et al., is an integrated width control concept (“ein integriertes Breitenregelungskonzept”, page 95, left col., last paragraph). This concept comprises (see FIG. 4 ) an edger E 1 , a measurement system, and sensors for monitoring the material position to derive the width of the rolled product along its length in the roughing mill (R 1 , R 2 ), the finishing mill (F 1 -F 6 ) and downstream of the finishing mill and furthermore algorithms and strategies for controlling the width of the rolled stock.
[0012] Essential Measurement of the Width is Done at:
[0013] Entry width at Edger E 1 , width of transfer bar downstream of R 2 , measurement of final strip width downstream of F 6 . Measured width data are considered by a level 2 process control (“PSC”), page 96, paragraph “Messwertverarbeitung”) of the roughing mill. The measured width data are assigned to specific positions of the rolled strip (rolled stock).
[0014] Detecting the width of the metal strip in each case after the second and after the last rolling stand of a finishing train is known from the technical article “Automatic width control system using interstand tension in hot strip finishing mill” by Y. Hoshi et al., La Revue de Metallurgie-CIT, November 1996, pages 1413 to 1420. The tension between the first and the second rolling stands is regulated by means of the former measurement. The tensions between the third and the last rolling stand are regulated by means of the latter measurement.
[0015] Detecting a variable which is characteristic for the mass flow between each two rolling stands and, building on the detected variable, setting the strip tension between the two rolling stands, in order to reduce a width change, is known from DE 103 38 470 B4.
[0016] A method for regulating the width in a rolling train having at least two rolling stands, through which the metal strip passes in succession, is known from DE 198 51 053 A1. In this method, the width is detected after the last rolling stand passes through. The tension between the two rolling stands is regulated to influence the width of the metal strip.
[0017] A method for regulating the strip width during the finish rolling of hot strip in a multi-stand rolling train is known from EP 0 375 095 B1. In this method, the strip width is measured before the next-to-last stand and after the last stand. A width regulation using pilot control is performed. The strip tension before the last rolling stand of the rolling train is used as the control variable.
[0018] A width model for a finishing train is known from the technical article “Strip width variation behavior and its mathematical model in hot strip finishing mills” by Atsushi Ishii et al., Proceedings of The 7th International Conference on Steel Rolling 1998, Chiba, Japan, pages 93 to 98. Width influences in the rolling gap, for example, a relative strip profile change, a roller bend, a compressed length, and the intake-side and outlet-side tension are taken into consideration. Furthermore, width influences in the region between two rolling stands are taken into consideration, for example, the temperature, the tension prevailing in the metal strip, the yield strength, the strip temperature, and the duration.
[0019] A simplified width model is derived building on a width model based on finite elements in the technical article “Direct Width Control Systems Based on Width Prediction Models in Hot Strip Mill” by Cheol Jae Park et al., ISIJ International, vol. (2007), issue 1, pages 105 to 113. The simplified width model is supplemented using a neuronal network. It models the width in the finishing train as a function of the intake-side tension in the metal strip, the present width, the thickness reduction, the compressed length, and the dimensional change resistance.
[0020] The methods of the prior art already cause the actual width of the metal strip to approximate the target width. The methods often only function inadequately, however. In addition, in a hot strip train without coil box, the temperature distribution is often uneven viewed over the length of the metal strip, which in turn results in an uneven widening of the metal strip in the finishing train.
SUMMARY OF THE INVENTION
[0021] The object of the present invention is to provide possibilities, by means of which the width of the metal strip can be set exactly in a simple and efficient manner.
[0022] According to the invention, a method is provided for rolling a metal strip in a finishing train which has multiple rolling stands through which the metal strip passes in succession.
[0023] The actual width and the actual temperature thereof are detected for each of the sections of the metal strip before they enter the finishing train.
[0024] An actual width derived from the detected actual width, an initial target width, an actual temperature derived from the detected actual temperature, and a target temperature are associated with each of the sections of the metal strip.
[0025] The sections of the metal strip are path-tracked during the passage through the finishing train.
[0026] A width control unit is associated at least with each of the rolling stands with the exception of the last rolling stand.
[0027] The respective width control unit for the section of the metal strip rolled in the associated rolling stand.
a) On the basis of all of its target width before the rolling in the associated rolling stand, a target tension desired in the metal strip before the associated rolling stand, a target tension desired in the metal strip after the associated rolling stand, the target temperature associated with the respective section and parameters of the rolling procedure performed in the associated rolling stand, ascertains a target width after the rolling in the associated rolling stand and associates it with the respective section of the metal strip. b) On the basis of all of its actual width before the rolling in the associated rolling stand, the target tension, which is corrected by an upstream additional target value, desired in the metal strip before the associated rolling stand, the target tension, which is corrected by a downstream additional target value, desired in the metal strip after the associated rolling stand, the actual temperature associated with the respective section, and the parameters of the rolling procedure performed in the associated rolling stand, ascertains an actual width after the rolling in the associated rolling stand and associates it with the respective section of the metal strip. The respective width control unit ascertains the downstream additional target value on the basis of the target tension desired in the metal strip after the associated rolling stand, the target temperature and the actual temperature of the section of the metal strip rolled in the associated rolling stand, the difference of target width and actual width of a section of the metal strip which is located at a predetermined point after the associated rolling stand, and the parameters of the rolling procedure.
[0030] The respective width control unit ascertains the downstream additional target value such that the actual width of the section of the metal strip rolled in the associated rolling stand approximates the target width of the rolled section.
[0031] The respective width control unit supplies the downstream additional target value to a respective tension regulator, which sets an actual tension prevailing in the metal strip after the associated rolling stand corresponding to the target tension corrected by the downstream additional target value.
[0032] Only a single width measurement and a single temperature measurement are thus required, specifically between the roughening train and the finishing train. Width deviations can be compensated for highly accurately. If a width regulation is additionally also to be implemented, an additional width measurement after the finishing train is required for this purpose. Such a width measurement is typically provided, however, and therefore does not require additional hardware expenditure.
[0033] In the simplest case, the actual widths and actual temperatures associated with the sections are identical to the detected actual widths and actual temperatures. However, preferably at least the detected actual widths, preferably also the detected actual temperatures are filtered, in particular low-pass filtered. By way of this procedure, the rolling of the metal strip can be performed relatively calmly (i.e., without high-frequency control interventions) in particular. The manipulation of the actual width via the strip tension thus has no negative effects on the rolling process.
[0034] The filtering can be in particular such that no phase offset is induced by the filtering in the filtered variable (actual width or actual temperature) in relation to the unfiltered variable. Thus, filterings are to be performed in zero-phase filters. For this purpose, it is possible to provide a corresponding symmetrical filter, for example. Alternatively, it is possible that the detected actual widths are subjected to a first filtering and thus preliminarily filtered actual widths are ascertained and then the preliminarily filtered actual widths are subjected to a second filtering and the filtered actual widths are thus ascertained. Alternatively, the detected actual widths can be subjected in parallel to both the first filtering and also the second filtering and the mean value of the two filterings can be used as the filtered actual width. In both cases, the two filterings can have phasing. It is only required that the two filterings have inverse phasing in relation to one another, so that the phase offset caused by one filtering can be compensated for or balanced out by the other filtering. Similar procedures are possible if necessary with respect to the actual temperatures.
[0035] It is possible that the initial target width is predefined. Alternatively, the initial target width can be ascertained on the basis of the actual width associated with the sections.
[0036] It is possible that the predetermined point is permanently specified. Alternatively, it is possible that the predetermined point is specified to the width control units (optionally individually for each width control unit). For example, the middle between the associated rolling stand and the rolling stand directly downstream can be specified as the predetermined point for the respective width control unit. It is also optionally possible to provide the location at which a loop lifter engages on the metal strip as the predetermined point.
[0037] A point in time at which the metal strip enters this rolling stand is preferably detected at least for the rolling stand of the finishing train through which the metal strip passes first. In this case, the path tracking can be adapted on the basis of this point in time, i.e., in particular started in a timely manner.
[0038] It is alternatively possible to detect the actual width at the outlet of the roughening train or at the inlet of the finishing train. It is also alternatively possible to detect the actual temperature at the outlet of the roughening train or at the inlet of the finishing train. It is furthermore alternatively possible to firstly detect the respective actual width and the respective actual temperature for the entire metal strip (i.e., for all sections of the metal strip) and only then to perform the low-pass filterings. Alternatively, it is possible to perform the low-pass filterings simultaneously with the detection of the actual width and the actual temperature. Performing the low-pass filterings beforehand is advisable in particular if the actual width and the actual temperature are detected at the outlet of the roughening train. Performing the low-pass filterings together with the detection of the actual width and the actual temperature is advisable in particular if the actual width and actual temperature are detected at the inlet of the finishing train. Depending on how much time passes between the low-pass filterings and the entries of the sections of the metal strip into the first rolling stand of the finishing train, it can be necessary to progress the time development of the temperature of the sections by means of a temperature model.
[0039] The number of rolling stands of the finishing train can be determined as needed. In general, the number of rolling stands is 3 to 8, usually 4 to 7, in particular 5 or 6.
[0040] In particular steel, aluminum, and copper come into consideration as the metal. However, it is also possible that the metal strip consists of another metal.
[0041] In the scope of the present invention, it is necessary at various points to know the velocity of the metal strip. For this purpose, it is possible to perform a corresponding velocity measurement directly. Alternatively, it is possible to ascertain the respective velocity in that, in relation to the point for which the velocity of the metal strip is to be detected, the circumferential velocity of rollers of an upstream rolling stand is detected and the velocity of the metal strip is ascertained therefrom in consideration of the lead. In a similar manner, it is possible, vice versa, to ascertain the respective velocity in that the circumferential velocity of rollers of a downstream rolling stand is detected and the velocity of the metal strip is ascertained therefrom in consideration of the lag.
[0042] In many cases, a final rolling temperature is specified, which the metal strip is to have at the outlet of the finishing train. In this case, the final rolling temperature is preferably used as the target temperature. The actual temperature of the sections of the metal strip, in contrast, is preferably continuously tracked in a model-supported manner during the passage of the sections of the metal strip through the finishing train.
[0043] The parameters of the rolling procedure can be determined as needed. In general, the rolling force, the rolling torque, the strip velocity on the inlet side and/or outlet side of the associated rolling stand, the rolling gap, the pass reduction, the compressed length of the metal strip, and material variables of the metal strip can be used as parameters of the rolling procedure, with respect to the associated rolling stand.
[0044] In the simplest case, in the scope of the method according to the invention, only the widening during rolling in the rolling stands themselves is taken into consideration. However, it is preferably provided that the respective width control unit for the sections of the metal strip already rolled in the associated rolling stand tracks the target width after the rolling as a function of the spacing from the downstream rolling stand, the strip velocity on the outlet side of the associated rolling stand, the target tension desired in the metal strip after the associated rolling stand, the target temperature, and material characteristic variables of the metal strip and also tracks the actual width after the rolling as a function of the spacing from the downstream rolling stand, the strip velocity on the outlet side of the associated rolling stand, the target tension desired in the metal strip after the associated rolling stand, which is corrected by the downstream additional target value, the actual temperature, and the material characteristic variables of the metal strip.
[0045] The creeping of the width between the rolling stands can also be taken into consideration by this procedure.
[0046] The object is furthermore achieved by a computer program such that the execution of the machine code by the control unit causes the control unit to operate the finishing train according to a method according to the invention.
[0047] The object is furthermore achieved by a control unit for a finishing train, wherein the finishing train is programmed using a computer program according to the invention, so that the control unit operates the finishing train according to a method according to the invention.
[0048] The object is furthermore achieved by a finishing train for rolling a metal strip. The control unit of the finishing train is designed to operate the finishing train according to a method according to the invention.
[0049] The above-described properties, features, and advantages of this invention and the manner in which they are achieved will become clearer and more comprehensible in conjunction with the following description of the exemplary embodiments, which are explained in greater detail in conjunction with the drawings. In the schematic figures:
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 shows a hot strip train,
[0051] FIG. 2 shows sections of a metal strip,
[0052] FIG. 3 shows a flow chart,
[0053] FIGS. 4 to 6 show filterings, and
[0054] FIG. 7A shows a section of a finishing train; and
[0055] FIG. 7B shows a width control unit for a metal strip.
DESCRIPTION OF EMBODIMENTS
[0056] According to FIG. 1 , a hot strip train for rolling a metal strip 1 has a roughening train 2 , a finishing train 3 , and a coiling device 4 . The roughening train 2 can be omitted in individual cases—for example, in the case in which the metal strip 1 is already cast relatively thin. The finishing train 3 has, according to FIG. 1 , multiple rolling stands 5 , through which the metal strip 1 passes in succession. The number of rolling stands 5 is generally between three and eight, in particular between four and seven, for example, five or six.
[0057] The metal strip 1 can be, for example, a steel strip, an aluminum strip, a copper strip, or a strip made of another metal.
[0058] The hot strip train—in particular the finishing train 3 —is controlled by a control unit 6 . The control unit 6 is programmed using a computer program 7 . The computer program 7 comprises machine code 8 , which is executable by the control unit 6 . The execution of the machine code 8 by the control unit 6 causes the control unit 6 to operate the finishing train 3 according to a method which will be explained in greater detail hereafter in conjunction with FIG. 2 and the further figures. As a result of the programming using the computer program 7 , the control unit 6 thus operates the finishing train 3 accordingly.
[0059] The metal strip 1 is virtually divided into sections 9 inside control unit 6 . The sections 9 can be defined, for example, according to FIG. 2 by a uniform length 1 , by a uniform mass m, or by a detection at chronologically equidistant steps.
[0060] According to FIG. 3 , in a step S 1 , the actual width b 0 and the actual temperature T 0 thereof is detected for each of the sections 9 of the metal strip 1 . The detection of the actual width b 0 and the actual temperature T 0 is performed before the entry of the corresponding sections 9 into the finishing train 3 . For example, according to FIG. 1 , corresponding measurement units can be arranged at the outlet of the roughening train 2 . Alternatively, the measuring units can be arranged at the inlet of the finishing train 3 . It is possible that the detection of the actual widths b 0 and the actual temperatures T 0 is completed for all sections 9 even before the frontmost section 9 of the metal strip 1 enters the finishing train 3 . Alternatively, it is possible that the detection of the actual widths b 0 and actual temperatures T 0 is still carried out for rear sections 9 of the metal strip 1 while front sections 9 of the metal strip 1 have already entered the finishing train 3 . Independently of the specific procedure used, the detection is performed, however, such that the association of an actual width b and an actual temperature T subsequently performed in a step S 2 is completed for each section 9 before the corresponding section 9 enters the finishing train 3 .
[0061] In the simplest case, in step S 2 , the detected actual widths b 0 and actual temperatures T 0 are associated directly with the sections 9 . However, at least the detected actual widths b 0 , and preferably also the detected actual temperatures T 0 , are preferably filtered. In particular, low-pass filtering can be performed according to the illustration in FIGS. 4 to 6 . In the case of a filtering, in step S 2 , a respective filtered actual width bF and a respective filtered actual temperature TF is ascertained for each section 9 .
[0062] The filtering of step S 2 is preferably performed such that the filtered actual widths bF do not have a phase offset in relation to the original, unfiltered actual widths b 0 (zero-phase filtering). For example, for this purpose, according to FIG. 4 , a filtering can be performed using a Gaussian bell curve (or another, symmetrical bell curve). Alternatively, one of the two following procedures is used.
[0063] On the one hand, it is possible according to the illustration in FIG. 5 that the detected actual widths b 0 are firstly subjected to a first filtering in a first filter block 10 . Preliminarily filtered actual widths bV are thus ascertained. The preliminarily filtered actual widths bV are then subjected to a second filtering in a downstream second filter block 11 . The results of the second filtering are the filtered actual widths bF. In this case, both the first filtering in the first filter block 10 and also the second filtering in the second filter block 11 can be subject to phasing. It is decisive in this case that the two filterings in the two filter blocks 10 , 11 are subject to inverse phasing in relation to one another. The second filtering in the second filter block 11 therefore compensates the phase offset which was caused by the first filtering in the first filter block 10 .
[0064] Alternatively, it is possible according to the illustration in FIG. 6 to carry out the two filterings in the two filter blocks 10 , 11 in parallel. In this case, the detected actual widths b 0 are thus subjected to both the first filtering and also the second filtering. The results of the two filterings are supplied in this case to a node point, in which the mean value of the two filterings is calculated. The mean value corresponds in this case to the filtered actual width bF.
[0065] Similar procedures can be used for the ascertainment of the filtered actual temperatures TF. In general, the same type of filtering is used for the ascertainment of the filtered actual temperatures TF as for the ascertainment of the filtered actual widths bF. However, this is not absolutely required. A zero-phase filtering is preferably also to be performed with respect to the actual temperatures T 0 .
[0066] In the case of a filtering, the filtered actual width bF ascertained for the respective section 9 of the metal strip 1 and the filtered actual temperature TF ascertained for the respective section 9 of the metal strip 1 are thus associated with the respective section 9 as the (new) actual width b or (new) actual temperature T, respectively. Furthermore, an initial target width b 0 * is associated with the respective section 9 as the target width b* and an initial target temperature T 0 * is associated as the target temperature T* in a step S 3 .
[0067] It is possible that the initial target width b 0 * is externally specified to the control unit 6 , for example, by a higher-order control unit (not shown) or by an operator 12 . Alternatively, it is possible that the control unit 6 ascertains the initial target width b 0 * on the basis of the actual width b associated with the sections 9 . For example, the control unit 6 can perform a mean value calculation over all sections 9 of the metal strip 1 . In general, a final rolling temperature is specified to the control unit 6 , i.e., the temperature which the metal strip 1 is to have upon exiting from the finishing train 3 . It is possible that this temperature is used as the initial target temperature T 0 * or the initial target temperature T 0 * is ascertained on the basis of the final rolling temperature.
[0068] The control unit 6 implements a path tracking for the sections 9 of the metal strip 1 on the basis of the execution of the computer program 7 in a step S 4 . It is therefore known to the control unit 6 at every point in time which section 9 of the metal strip 1 is located at which point of the finishing train 3 . The implementation of a path tracking is generally known to a person skilled in the art and therefore does not have to be explained in greater detail.
[0069] For the correct path tracking of the sections 9 of the metal strip 1 , it is often necessary to detect a point in time t 1 at which the metal strip 1 more precisely: the frontmost section 9 of the metal strip 1 enters the rolling stand 5 through which the metal strip 1 passes first. The point in time t 1 can be detected, for example, in that the rolling force of this rolling stand 5 suddenly increases. In a similar manner, corresponding points in time t 2 , t 3 , etc. can also be detected for the other rolling stands 5 of the finishing train 3 . The path tracking can be adapted in this manner on the basis of the detected points in time t 1 , t 2 , etc.
[0070] The control unit 6 furthermore implements a width control unit at least for each of the rolling stands 5 with the exception of the last rolling stand 5 of the finishing train 3 on the basis of the execution of the computer program 7 in a step S 5 . The respective width control unit 13 is associated with the respective rolling stand 5 . It is possible that such a width control unit 13 is also provided for the last rolling stand 5 of the finishing train 3 . However, this is not absolutely required. The construction and the functionality of one of the width control units 13 will be explained hereafter in conjunction with FIG. 7B as a representative for all width control units 13 . Similar statements apply for the other width control units 13 .
[0071] The width control unit 13 is associated with a specific rolling stand 5 . In the illustration of FIG. 7A , this is the middle rolling stand 5 , referred to hereafter as the associated rolling stand and provided with reference sign 5 b . The rolling stand 5 upstream from the associated rolling stand 5 b is provided hereafter with the reference sign 5 a . In a similar manner, the rolling stand 5 downstream from the associated rolling stand 5 b is provided hereafter with the reference sign 5 c.
[0072] The width control unit 13 of FIG. 7B has at least function blocks 14 to 19 .
[0073] The following variables are supplied to the function block 14 :
The target width b*, which is associated with the section 9 of the metal strip 1 presently being rolled in the associated rolling stand 5 b before the rolling in the associated rolling stand 5 b . In the case of the width control unit 13 associated with the first rolling stand 5 of the finishing train 3 , the target width b* corresponds to the initial target width b*. In the case of the other width control units 13 , the target width b* is provided by the function block 15 of the width control unit 13 associated with the upstream rolling stand 5 a. A target tension Z 1 * is to prevail in the metal strip 1 before the associated rolling stand 5 b . The target tension Z 1 * is determined by a corresponding specification from the higher-order control unit. Additional control interventions of the operator 12 can be taken into consideration if necessary. A target tension Z 2 * is to prevail in the metal strip 1 after the associated rolling stand 5 b . The target tension Z 2 * is determined by a corresponding specification from the higher-order control unit. Additional control interventions of the operator 12 can also be taken into consideration if necessary here. The target temperature T* is associated with the section 9 of the metal strip 1 presently being rolled in the associated rolling stand 5 a before the rolling in the associated rolling stand 5 b. Parameters P of the rolling procedure occur in the associated rolling stand 5 b . For example, always in relation to the associated rolling stand 5 b , the rolling force, the rolling torque, the strip velocity on the inlet side and/or outlet side of the associated rolling stand, the rolling gap, the pass reduction, the compressed length of metal strip 1 , and possibly temperature-related material variables M of the metal strip 1 can be used as the parameters P of the rolling procedure. The material characteristic variables M can comprise, for example, the modulus of elasticity, the yield strength, the forming resistance, and the like.
[0079] On the basis of the variables applied to the function block 14 , the function block 14 ascertains a target width after the rolling in the associated rolling stand 5 b . The function block 14 associates the ascertained target width as the new target width b* with the corresponding section 9 of the metal strip 1 . The function block 14 supplies the new target width b* to the function block 15 . The function block 14 thus internally models, with respect to the target values b*, T* of the respective section 9 of the metal strip 1 , the widening behavior thereof in the rolling gap of the associated rolling stand 5 b . The function block 14 therefore internally comprises a model of the associated rolling stand 5 b which is based on mathematical-physical equations, in particular algebraic and differential equations. Such models are known per se to those skilled in the art. See the two technical articles mentioned at the outset “Strip width variation behaviour and its mathematical model in hot strip finishing mills” by Atsushi Ishii et al. and “Direct Width Control Systems Based on Width Prediction Models in Hot Strip Mill” by Cheol Jae Park et al.
[0080] In the simplest case, the function block 15 is designed as a simple buffer memory in the manner of a shift register or the like, in which solely the transport of the sections 9 of the metal strip 1 (including the target variables b*, T* which are associated with the sections 9 ) to the downstream rolling stand 5 c is modeled. However, the target tension Z 2 *, which is desired in the metal strip 1 after the associated rolling stand 5 b , and the material characteristic variables M of the metal strip 1 are preferably supplied to the function block 15 . In this case, the function block 15 implements, in addition to the simple transport of the sections 9 of the metal strip 1 , the creeping behavior of the target width b* of the sections 9 of the metal strip 1 buffered in the function block 15 . The function block 15 thus tracks, for the buffered sections 9 , the respective target width b* after the rolling in the associated rolling stand 5 b as a function of the target tension Z 2 *, which is desired in the metal strip 1 after the associated rolling stand 5 b , the target temperature T*, and the material characteristic variables M of the metal strip 1 . Furthermore, the spacing a in relation to the downstream rolling stand 5 c (more precisely: the spacing a plus the strip reserve stored between the associated rolling stand 5 b and the downstream rolling stand 5 c ) and the strip velocity v after the associated rolling stand 5 b are implicitly incorporated into the ascertainment of the function block 15 . This is because these two variables a, v determine the transport time for which the sections 9 of the metal strip 1 are located in the inter-stand region between the associated rolling stand 5 b and the downstream rolling stand 5 c . The function block 15 provides, at the point in time of the rolling of a respective section 9 of the metal strip 1 in the downstream rolling stand 5 c , the target width b* before the rolling in the downstream rolling stand 5 c to the width control unit 13 associated with the downstream rolling stand 5 c.
[0081] The spacing is a fixed variable, which only has to be parameterized once. If the stored strip reserve is also to be taken into consideration, this is easily possible. This is because the stored strip reserve can be ascertained in a simple manner by the position of a loop lifter 20 , which is arranged between the associated rolling stand 5 b and the downstream rolling stand 5 c . The strip velocity v can vary in operation. It is possible to measure the strip velocity v directly by means of a corresponding measuring unit. Alternatively, the circumferential velocity of rollers of the associated rolling stand 5 b can be measured and the strip velocity v can be ascertained therefrom in conjunction with the known lead. Again alternatively, the circumferential velocity of rollers of the downstream rolling stand 5 can be measured and the strip velocity v can be ascertained therefrom in conjunction with the known lag. The procedure which is used is the choice of a person skilled in the art.
[0082] The function block 16 is structurally and functionally equivalent to the function block 14 with regard to the approach. However, the following input variables are changed:
Instead of the target width b*, the actual width b of the section 9 of the metal strip 1 presently being rolled in the associated rolling stand 5 b is used. In the case of the width control unit 13 associated with the first rolling stand 5 of the finishing train 3 , the actual width b corresponds to the actual width b associated with the sections 9 in step S 2 of FIG. 3 . In the case of the other width control units 13 , the actual width b is provided by the function block 17 of the width control unit 13 associated with the upstream rolling stand 5 a. Instead of the target tension Z 1 *, a target tension corrected by an upstream additional target value δZ 1 * is used. In the case of the width control unit 13 associated with the first rolling stand 5 of the finishing train 3 , the upstream additional target value δZ 1 * has the value 0. In the case of the other width control units 13 , the upstream additional target value δZ 1 * is provided by the function block 19 of the width control unit 13 associated with the upstream rolling stand 5 . Instead of the target tension Z 2 *, a target tension corrected by a downstream additional target value δZ 2 * is used. The downstream additional target value δZ 2 * is provided according to FIG. 7 by the function block 19 of the respective width control unit 13 of FIG. 7B . Instead of the target temperature T*, the actual temperature T is used. In the case of the width control unit 13 associated with the first rolling stand 5 of the finishing train 3 , the actual temperature T corresponds to the actual temperature T associated with the sections 9 in step S 2 of FIG. 3 . In the case of the other width control units 13 , the actual temperature T is provided by the width control unit 13 associated with the upstream rolling stand 5 a.
[0087] The remaining variables are identical to those of the function block 14 .
[0088] On the basis of the variables supplied to the function block 16 , the function block 16 ascertains an actual width after the rolling in the associated rolling stand 5 b . The function block 16 associates the ascertained actual width as the new actual width b with the corresponding section 9 of the metal strip 1 . The function block 16 supplies the new actual width b to the function block 17 . The function block 16 thus internally models, with respect to the actual values b, T of the respective section 9 of the metal strip 1 , the widening behavior thereof in the rolling gap of the associated rolling stand 5 b.
[0089] The function block 17 is structurally and functionally equivalent to the function block 15 with regard to the approach. However, if the function block 17 similarly to the function block 15 implements not only the transport of the sections 9 of the metal strip 1 (including the actual variables b, T associated with the sections 9 ) to the downstream rolling stand 5 c , but rather also the creeping behavior of the actual width b of the sections 9 of the metal strip 1 buffered in the function block 15 , the target tension Z 2 * corrected by the downstream additional target value δZ 2 * and furthermore as also in the function block 15 the material characteristic variables M of the metal strip 1 are supplied to the function block 17 . In this case, the function block 17 thus tracks the respective actual width b for the buffered sections 9 after the rolling in the associated rolling stand 5 b as a function of the target tension Z 2 *, which is corrected by the downstream additional target value δZ 2 *, the actual temperature T, and the material characteristic variables M of the metal strip 1 . The spacing a in relation to the downstream rolling stand 5 c and the strip velocity v after the associated rolling stand 5 b are implicitly also incorporated into the ascertainment of the function block 17 , as previously in the function block 15 .
[0090] Furthermore and a difference exists here from the function block 15 the function block 17 generally tracks the actual temperature T of the sections 9 , which are stored in the function block 17 , continuously in a model-supported manner. The corresponding models are known to a person skilled in the art from the two above-mentioned technical articles and also in other ways. As a result, the actual temperature T of the sections 9 is therefore continuously tracked in a model-supported manner during the passage of the sections 9 of the metal strip 1 through the finishing train 3 .
[0091] The newly ascertained target width b* is supplied by the function block 14 and the newly ascertained actual width b is supplied by the function block 15 to the function block 18 . The function block 15 calculates the difference δb between target width b* and actual width b. Furthermore, the function block 18 buffers the difference δb ascertained thereby. The buffering is determined such that the section 9 of the metal strip 1 to which the ascertained difference δb relates, is located at a predetermined point between the associated rolling stand 5 b and the downstream rolling stand 5 c at the point in time at which the difference δb is output by the function block 18 .
[0092] The predetermined point can be established as needed. The predetermined point can be, for example, the location at which the loop lifter 20 downstream from the associated rolling stand 5 b acts on the metal strip 1 . Alternatively, it can be a location in the region of the middle between the associated rolling stand 5 b and the downstream rolling stand 5 c , in particular exactly at the middle. The predetermined point can preferably be specified to the respective width control unit 13 , in particular by the operator 12 or by the above-mentioned higher-order control unit.
[0093] The function block 18 supplies the difference δb to the function block 19 . Furthermore, the target tension Z 2 *, the target temperature T*, and the actual temperature T, as well as the parameters P of the rolling procedure occurring in the respective rolling stand 5 , are supplied to the function block 19 . Furthermore, the widths b*, b, which are output from the function blocks 14 and 16 , are often supplied per se to the function block 19 . The function block 19 ascertains the downstream additional target value δZ 2 * on the basis of the variables supplied thereto. The ascertainment is performed such that the actual width b of the section 9 of the metal strip 1 rolled in the associated rolling stand 5 b approximates the target width b* of the rolled section 9 . In particular, the ascertainment is preferably performed such that the approximation is optimized for the point in time at which the section 9 , for which the downstream additional target value δZ 2 * is ascertained, runs out of the downstream rolling stand 5 c.
[0094] It is possible that the ascertainment is performed such that the actual width b is equal to the target width b*, i.e., complete correction is performed. Alternatively, it is possible that only partial correction is performed. The procedure which is utilized in the individual case is the choice of the person skilled in the art. In particular, it is possible to perform complete or nearly complete correction for the upstream rolling stands 5 of the finishing train 3 , so that no or only residual corrections still have to be performed in the downstream rolling stands 5 of the finishing train 3 .
[0095] The function block 19 furthermore supplies the downstream additional target value δZ 2 * to a tension regulator 21 . Furthermore, the target tension Z 2 * and an actual tension Z 2 , which prevails in the metal strip 1 after the associated rolling stand 5 b , are supplied to the tension regulator 21 . The tension regulator 21 sets the actual tension Z 2 , which prevails in the metal strip 1 after the associated rolling stand 5 b , in accordance with the target tension Z 2 * corrected by the downstream additional target value δZ 2 *. For example, the tension regulator 21 can act for this purpose on the loop lifter 20 in accordance with the illustration in FIG. 7 . Alternatively or additionally, the tension regulator 21 can act on the roller circumferential velocity of the associated rolling stand 5 b and/or the downstream rolling stand 5 c . Alternatively or additionally, the tension regulator 21 can act on the setting of the downstream rolling stand 5 c.
[0096] In summary, the present invention therefore relates to the following substantive matter:
[0097] Before the rolling of a metal strip 1 in a finishing train 3 , the actual width b 0 and the actual temperature T 0 thereof is detected in each case for sections 9 of the metal strip 1 . Variables bF, TF, which are derived from the detected variables b 0 , T 0 , and the corresponding target variables b*, T* are associated with the sections 9 . The sections 9 of the metal strip 1 are tracked during the passage through the finishing train 3 . A width control unit 13 is associated with each of the rolling stands 5 . The width control units 13 ascertain, on the basis of various input variables, the target width b* and the actual width b after the rolling in the associated rolling stand 5 b . The width control units 13 furthermore ascertain a downstream additional target value 5 Z 2 *, by which the target tension Z 2 * is to be corrected after the associated rolling stand 5 b , to approximate the actual width b to the target width b*. The downstream additional target value δZ 2 * is both taken into consideration in the ascertainment of the actual width b and also supplied to a tension regulator 21 , which sets an actual tension Z 2 , which prevails in the metal strip 1 after the associated rolling stand 5 b , in accordance with the corrected target tension Z 2 *. For the ascertainment of the downstream additional target value δZ 2 *, inter alia, the difference δb of target width b* and actual width b of a section 9 of the metal strip 1 is used, which is located at a predetermined point after the associated rolling stand 5 .
[0098] The present invention has many advantages. Thus, for example, in the scope of the present invention, no measurement of temperatures T and widths b is required within the finishing train 3 . Such a detection is only required before the finishing train 3 . These detections are typically provided. In addition, the width b can be detected at the outlet of the finishing train 3 for quality control, for adaptation of the process model used, and possibly for optional width regulation. However, this is not absolutely required. If a width regulation is also implemented in addition to the width control according to the invention, the width regulation corrects, as a function of the actual width b after the finishing train 3 and the target width b* at this point, at least the target widths b*, possibly also the actual widths b.
[0099] The correction is performed for the individual rolling stands 5 , with which a width control unit 13 is associated. The correction is performed such that the ascertained auxiliary target values δZ 1 *, 5 Z 2 * compensate for the width deviation at the outlet of the finishing train 3 . The control interventions are allocated onto multiple rolling stands 5 within the finishing train 3 . The compensation in the upstream rolling stands 5 preferably dominates in this case. Preferably, only residual deviations are compensated for in the downstream rolling stands 5 .
[0100] Although the invention was illustrated and described in greater detail by the preferred exemplary embodiment, the invention is not thus restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art, without leaving the scope of protection of the invention.
LIST OF REFERENCE SIGNS
[0000]
1 metal strip
2 roughening train
3 finishing train
4 coiling device
5 , 5 a to 5 c rolling stands
6 control unit
7 computer program
8 machine code
9 sections
10 , 11 filter blocks
12 operator
13 width control units
14 to 19 function blocks
20 loop lifter
21 tension regulator
a spacing
b, b 0 actual widths
b*, b 0 * target widths
bF filtered actual widths
bV preliminarily filtered actual widths
L length
m mass
M material characteristic variables of the metal strip
P parameters of the rolling procedure
S 1 to S 5 steps
t time span
t 1 , points in time
T, T 0 actual temperatures
T*, T 0 * target temperatures
TF filtered actual temperatures
TV preliminarily filtered actual temperatures
v strip velocity
Z 1 , Z 2 actual tensions
Z 1 *, Z 2 * target tensions
δb difference between target width and actual width
δZ 1 *, δZ 2 * auxiliary target values | Before the rolling of a metal strip on a finishing train, the actual width and actual temperature of portions of the metal strip are respectively detected. The portions of the metal strip are tracked while they run through the finishing train. The rolling stands are respectively assigned width controlling devices which determine the setpoint width and the actual width after the rolling in the assigned rolling stand, and a downstream additional setpoint value, by which the desired tension downstream of the assigned rolling stand is corrected in order to bring the actual width closer to the setpoint width. The downstream additional setpoint value is both taken into account in the determination of the actual width and fed to a tension controller, which sets an actual tension, in the metal strip downstream of the assigned rolling stand, in accordance with the corrected setpoint tension. Determining the downstream additional setpoint value by the difference between the setpoint width and the actual width of a portion of the metal strip. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a collection assembly and more particularly to a microcollection container and cap suitable for collecting small quantities of blood from a patient and maintaining the blood in secure fashion for subsequent testing.
2. Description of Related Art
Analytical instrumentation has made it possible to carry out a variety of hematological diagnostic procedures on very small quantities of blood. Because of this, a patient's finger or earlobe, for example, may be punctured and a very small quantity of blood may be rapidly collected into a container for such testing. However, in order to carry out testing and analysis on small quantities of blood, the blood must be rapidly collected prior to any coagulation thereof.
A collection arrangement as described in U.S. Pat. No. 4,397,318, has been provided wherein a cap is configured to fit the top of a microcollection container with the cap having a removable capillary scoop for engaging the puncture site and transferring blood to the container. However, with such an arrangement, if precise positioning is not carried out, capillary action is not initiated or slowed and the collected blood will clot.
Moreover, when a sample is taken with this collection arrangement, blood droplets may be left in and around the top area of the container. When the scoop is removed from the cap and the cap is fitted onto the top of the container, the excess blood may be forced onto the outside surface of the container.
SUMMARY OF THE INVENTION
The present invention is a collection assembly comprising a container and a cap. The cap preferably comprises a top portion, a bottom portion, and an annular skirt extending from the top portion to the bottom portion having an inner surface and an outer surface. The cap further includes an inner inverted skirt portion surrounded by the inner surface of the annular skirt. Most preferably the inner inverted skirt portion is separated from the inner surface of the annular skirt by an annular space. Most preferably, the cap also includes a cam follower positioned on the bottom portion. Desirably, the inside surface of the annular skirt comprises at least one protrusion and the inner inverted skirt portion has a sealing ring. The cap further comprises a rim extending from the outer surface of the annular skirt.
The container preferably comprises an open top portion, a closed bottom portion, a sidewall extending from the top portion to the bottom portion and an open end associated with the top portion having an integral collector. Most preferably the integral collector is a scoop that is the same diameter as the inner diameter of the container so that no air vent is required.
Preferably, the container further includes a cap seating flange associated with the outer diameter of the top portion of the container and an extending annular skirt associated with the bottom portion. Most preferably, a reservoir is positioned within the cap seating flange and at least one lug is located in the reservoir. Preferably, the container also includes a locking ring associated between the integral collector and the cap seating flange.
Preferably, the collection assembly includes means for securing the inner surfaces of the cap to the top portion of the container by the interaction of the protrusions of the cap with the locking ring of the container and the sealing ring of the cap with the inside surface of the top portion of the container. Most preferably, the collection assembly also includes means for unsecuring the cap from the container by a cam arrangement on the cap and container. This cam arrangement assists in substantially reducing fluid splatter from the container when the cap is removed from the container.
In a preferred embodiment of the invention, the cam arrangement includes at least one cam follower positioned on the bottom portion of the cap and at least one cam surface positioned in the cap seating flange of the container. A downwardly rotational force applied to the cap and an upwardly force applied to the container along the longitudinal axis, causes the cam follower and the cam surface to align and the cap to snap-seal to the container by the interaction of the protrusions of the cap with the locking ring of the container and the sealing ring of the cap with the inside surface of the top portion of the container. This action, which may cause an audible-snap, in turn seals the container by compressing the protrusions of the cap against the locking ring of the container and the sealing ring of the cap against the inside surface of the top portion of the container to form a non-permanent lock and to substantially prevent the outer surface of the top portion of the container from making contacting with the inside surface of the cap's annular skirt.
The cap and container are then unsecured in a twist off manner by applying a rotational force to the cap. Most preferably, an upward rotational force is applied to the cap and a downwardly force applied to the container along the longitudinal axis. This causes the cam follower to rise on the cam surface and in turn the cap is unsecured from the container. An important advantage of the present invention is that the rotational force applied to the cap can be bi-directional, that is clockwise or counter-clockwise.
The collection assembly of the present invention is preferably used in micro-centrifuges. However, an extension may be secured and unsecured to the bottom portion of the container. The extension increases the length dimension of the container. With the extension, the container may be compatible with standard clinical centrifuges.
An advantage of the present invention is that any excess fluid on the outside surface of the integral collector is directed downwardly into the cap seating flange by the inner surface of the annular skirt of the cap when a downward force is applied to the cap as the cap and container are being secured. Therefore, radial spray of excess fluids are minimized.
Another advantage of the invention is that the cap may be secured and unsecured to the bottom portion of the container. In particular, the annular space in the cap between the annular skirt and inverted skirt allows the cap to be removably secured with the bottom portion of the container by receiving the annular skirt of the container.
Still another advantage of the invention is that the recessed inverted skirt and the sealing-ring substantially reduces cap contact with fluid collected in the container. Therefore the inner surfaces of the cap may be minimally exposed to fluid collected in the container when the cap is secured to the top portion of the container.
Another advantage of the present invention is that the outer surface of the cap may preferably be configured to substantially limit movement or rolling of the cap or the assembly. This applies whether the cap is positioned with the top portion or bottom portion of the container.
Still another advantage of the present invention is that when the cap is secured to the container, the rim of the cap substantially prevents contamination to the specimen inside the container.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred collection assembly illustrating the container with the cap unsecured.
FIG. 2 is a side elevational view of the container of FIG. 1, partially in section of the cam surface area.
FIG. 3 is an enlarged cross sectional view of the cap of FIG. 1, taken along line 3--3 thereof.
FIG. 4 is a bottom view of the cap of FIG. 1.
FIG. 5 is a side elevational view, partially in section of the collection assembly of FIG. 1 with the cap secured to the top portion of the container.
FIG. 6 is a side elevational view, partially in section of the collection assembly of FIG. 1 with the cap removably secured to the bottom portion of the container.
FIG. 7 is a perspective view of the preferred collection assembly FIG. 1 and an optional extension that may be removably secured to the collection assembly.
FIG. 8 is a side elevational view, partially in section of the collection assembly of FIG. 7 with an extension removably secured to the bottom portion of the container.
DETAILED DESCRIPTION
Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, FIG. 1 illustrates a collection assembly 10 comprising a container 12 and a cap 14.
As illustrated in FIG. 1, container 12 has a sidewall 22 having an outer surface 24 and an inner surface 26. The sidewall extends from an upper portion 28 to a lower portion 30. Upper portion 28 includes an open end 31 and an inner surface 27 with a top surface 32 having an integral lip portion 34 with a receiving edge 36. Lower portion 30 comprises a closed bottom end 38 and an annular skirt 37 extending from the closed bottom end and outer surface 24 to define a compartment area 39. Annular skirt 37 provides a means for allowing the container to be placed upright on a flat surface.
Upper portion 28 has a cap seating flange 40 positioned around the outer surface of the container which defines a well or trough 42 and an outer surface 41. The cap seating flange has an upper surface edge 43 and a plurality of lugs 44 each having a cam surface 46. Although a container having only one projecting lug is within the purview of the instant invention, a plurality of lugs is preferred. Also, although other shapes and configurations are within the purview of the instant invention, lugs 44 of this embodiment are triangularly shaped.
As shown in FIG. 2, further positioned on the outer surface of the container on the upper portion is a locking ring 48 positioned between receiving edge 36 of integral lip portion 34 and cap seating flange 40. The locking ring has an upper edge 50 and a lower edge 52.
Cap 14 as shown in FIG. 3, has a top surface 54, a bottom stop ledge 56 and an annular outer skirt 58 extending from the top surface to the bottom stop ledge. The annular outer skirt has an outer wall surface 60 and an inner wall surface 62. A shield 66 extends from the outer wall surface of the annular outer skirt and has an outer surface or circumference 76.
As shown in FIG. 3, cap 14 also has an inner annular inverted recessed skirt portion 64 that extends from top portion 54 to a bottom surface 63. The inverted recessed skirt portion defines a compartment or cup area 65 on the top portion of the cap. The inner wall surface of the annular outer skirt and the inner annular inverted recessed skirt are spaced from each other to define an annular space 68. The cap further includes, a plurality of circumferentially spaced protrusions 70 positioned on inner wall surface 62 and a sealing ring 67 positioned on inverted recessed skirt portion 64. Projecting lugs 72 are located on bottom stop ledge 56 wherein each lug comprises a cam follower surface 74. Although a cap having only one projecting lug is within the purview of the instant invention, a plurality of lugs is preferred. Also, although other shapes and configurations are within the purview of the instant invention, lugs 72 of this embodiment are triangularly shaped.
As shown in FIG. 4, flats 77 are positioned on the outer surface of shield 66. The flats substantially prevent the cap from rolling and provide a convenient grasping surface for ready removal and placement of the cap on the container. Although a shield with a smooth outer circumference without flats is within the purview of the instant invention, a shield with an outer surface with flats is preferred.
As shown in FIG. 5, when cap 14 is removably secured to container 12, space 68 of the cap receives the top portion of the container including the integral lip, protrusions 70 bear against lower edge 52 of locking ring 48 of the container, sealing ring 67 bears against inner surface 27 of the container and cam follower 74 contacts cam surface 46. Shield 66 covers outer surface 44 of cap seating flange 40 mid bottom stop ledge 56 abuts with upper surface edge 43 of the cap seating flange 40, so as to form a non-permanent lock and substantially prevent any excess fluid in well 42 of the cap seating flange from spilling out. Any fluid that migrates between upper surface edge 43 and bottom stop ledge 56 is directed in a downward direction along the container. Further, any fluid in well 42 is substantially contained by the upper surface edge of the cap seating flange and the bottom stop ledge of the cap.
Cam follower surface 74 and cam surface 46 are configured so that a downwardly rotational force applied to cap 14 about longitudinal axis 80 causes cam follower 74 to contact cam surface 46. Cap 14 is snapped onto the top portion of the container as guided by cam follower surface 74 and cam, surface 46. Cap 14 is removably secured to container 12 by protrusions 70 and sealing ring 67 as they bear respectfully against lower edge 52 of the locking ring and inner surface 27 of the container. The position of the protrusions and sealing ring of the cap with the container forms space 69 between the outer surface of the top portion of the container and the inner wall surface of the cap's annular outer skirt. Therefore, wiping down of any fluid on the container's outer surface is substantially prevented.
The cap is unsecured from the container in a twist-off manner by applying a rotational force about longitudinal axis 80 while holding the container. Rotation of the cap with respect to the container causes cam follower surface 74 to rise on cam surface 46 and in turn the cap is unsecured from the container. The rotational force applied to the cap can be bi-directional, that is clockwise or counter-clockwise.
As shown in FIG. 6, cap 14 is readily compatible with skirt 37 on the lower portion of the container. Space 68 of the cap receives the skirt of the container. When the cap is positioned on the bottom of the container during fluid collection, the cap provides a means for allowing the container to be placed upright on a flat surface.
As shown in FIGS. 7 and 8, extension 90 is optionally available to be inserted into skirt 37 on the lower portion of container 12. The extension may be optionally used to make the collection assembly compatible with standard centrifuges or the need for additional space for labeling. Multiple extensions may be used if needed.
The collection assembly of the invention may be made of a clear molded thermoplastic material so that the specimen collected may be readily viewed. Representative materials include, for example, polyethylene, polypropylene and polyvinyl chloride. The collection container may incorporate a hydrophilic material or a silicon may be applied to the internal surface thereof for enhancing the flow of blood introduced into the container.
Although is within the purview of the invention to provide caps which are colored to define specific forms of fluid collection containers containing materials for one reason or another or for defining the kind of examination to be conducted on the specimen collected, transparent caps may be provided. Also, it should be noted that the dimensions of the container are such as to provide space for labeling which may be important for identifying the collected specimens. | The present invention is a collection assembly useful for collecting small quantities of blood. The assembly comprises a container with an integral lip for facilitating collection of the blood and a cap suitable for enclosing the container. The assembly further comprises a sealing arrangement for securing the cap with the container and a cam arrangement for unsecuring the cap from the container. | 2 |
BACKGROUND OF INVENTION
1. Field of the Invention
4,4-DIPHENYLBUTYL-1-(4-BENZOYL-4-HYDROXY OR ACYLOXY) PIPERIDINES AND ACID ADDITION SALTS THEREOF; CENTRAL DEPRESSANT, NEUROLEPTIC COMPOUNDS; 4-BENZOYL-4-HYDROXYPIPERIDINE AND OTHER INTERMEDIATES THEREFOR.
2. Prior Art
A number of ketones of the general formula ##STR1## wherein R 3 and R 4 are widely different groups, have been made and tested. As to these type compounds, Janssen (Cavallito; "Structure-Activity Relationships I", page 37) has stated that one of the groups R 3 and R 4 must be aromatic and that only one may be hydrogen if the ketone is to be an anti-psychotic.
For comparison with the compounds of the present invention, we have used three clinically-established compounds, namely:
Haloperidol, of the foregoing formula, wherein R 3 = OH and R 4 = ##STR2##
Chloropromazine, having the formula ##STR3## AND Pimozide, having the formula ##STR4##
These established clinically-useful compounds of the prior art have, however, been found to be characterized by pronounced shortcomings and side-effects, and there is a clear demand for more specific and advantageous compounds in this activity and utility area, especially as neuroleptics (anti-psychotics). The fulfillment of this demand is one of the objects of the present invention, as will become more fully apparent hereinafter.
SUMMARY OF THE INVENTION
This invention relates to novel 4,4-diphenylbutyl-1-(4-benzoyl-4-hydroxy or acyloxy)-piperidines, acid addition salts thereof, pharmaceutical compositions containing the same, a method of using the same as neuroleptics, and a process for the manufacture thereof, as well as novel intermediates, e.g., 4-benzoyl-4-hydroxypiperidines. The novel compounds provided by the present invention are selected from the group consisting of (a) 4,4-diphenylbutyl-1-(4-benzoyl-4-hydroxy or acyloxy)-piperidines, having the general formula ##STR5## wherein R and R 1 independently represent hydrogen or a loweralkyl group with 1 to 5 carbon atoms, inclusive, halogen including F, Cl, and Br, lower-alkoxy having 1-5 carbon atoms, inclusive, or --CF 3 , and R 2 represents hydrogen or an acyl (Ac) group having 1 to 19 carbon atoms, inclusive, and
b. acid addition salts thereof.
These novel compounds of Formula I have valuable pharmacological properties, especially central depressant effects as further elucidated hereinafter, which makes them useful as neuroleptics (i.e., anti-psychotically-active substances).
OBJECTS
It is an object of the present invention to provide novel 4,4-diphenylbutyl-1-(4-benzoyl-4-hydroxy or acyloxy)-piperidines and acid addition salts thereof, which are useful as central depressants, e.g., neuroleptics (anti-psychotics), a process for producing the same, pharmaceutical compositions thereof, intermediates therefor, and a method of treating psychotic states therewith. Additional objects will become apparent hereinafter, and still others will be obvious to one skilled in the art.
PREPARATION
According to the present invention, the novel compounds of General Formula I are prepared:
ROUTE 1
a. by reaction of a 4-benzoylpiperidine II ##STR6## with the compound ##STR7## wherein Y is halogen, e.g., Cl or Br, preferably Br, or another reactive group, e.g., ##STR8## or tosyl, to produce the compound ##STR9## and then introducing the OR 2 group, i.e., the hydroxy or acyloxy group, into the 4-position of the piperidino radical, preferably by first brominating to produce the compound ##STR10## followed by debromination with e.g., sodium methoxide in methanol, to produce the compound ##STR11## and then hydrolyzing to the hydroxy compound I, wherein R 2 =H, after which the hydroxy compound may be acylated, if desired, in conventional manner, to produce the corresponding acyloxy compound I wherein R 2 is acyl; or
ROUTE 2
b 1. by reacting the 4-benzoylpiperidine VII ##STR12## with the compound III to produce the corresponding compound I, or
ROUTE 3
b 2. by reacting the 4-benzoylipiperidine VII with the compound VIII ##STR13## wherein Y has the meaning previously assigned, to produce the compound ##STR14## and selective reduction to produce compound I; or
ROUTE 4
c 1. By reacting compound III with ##STR15## or an ester thereof to produce the compound ##STR16## converting the carboxy group or an ester thereof to the acid chloride and performing a Friedel-Crafts reaction thereon with AlCl 3 and a substituted benzene of the formula RR 1 -benzene to produce the compound of formula IV, or
ROUTE 5
c 2. by reacting compound VIII in the same manner as given in (c 1) and then selectively reducing to produce compound X.
Of the described methods, a) and b 1) are preferred, and the synthesis can always be carried out with one of these methods.
The starting compounds ##STR17## are synthesized according to French Patent M 3695 (CA 66, 115 709).
The benzoylpiperidine II and the novel 4-benzoyl-4hydroxypiperidine VII, both of which are intermediates in the process of the invention, can be prepared by a sequence of reactions starting with isonipecotic acid and proceeding via the 1-acetylisonipecotic acid or 1-methylisonipecotic acid and its acid chloride. This latter compound is then reacted with a
suitable known RR 1 -substituted benzene compound as follows: IA) a Friedel-Crafts reaction of ##STR18## wherein R 3 is acetyl and an RR 1 -substituted benzene in a suitable reaction solvent, e.g., nitrobenzene or an excess of the reacting compound RR 1 -benzene, to produce a compound ##STR19## whereupon the acetyl group (XI, R 3 = CH 3 CO) is removed with 5-N HCl to produce the compound II, or I B) a Grignard reaction of 4-cyanopyridine and a suitable known phenyl magnesium bromide or other halide of the formula RR 1 -phenyl-Mg X to produce the compound ##STR20## the 4-benzoylpyridine XII is then either (a) hydrogenated over platinum catalyst to give the 4-piperidylarylcarbinol ##STR21## wherein R 3 represents hydrogen, or (b) first benzylated or methylated to the corresponding 1-benzyl- (or methyl) 4-aroylpyridinium halide and then reduced to compound XIII (R 3 =benzyl or CH 3 ).
Compound XIII is then oxidized by chromic oxide or another oxidizing acid in acetic acid to the compound II (R 3 = H) or compound XI (R 3 = CH 3 or benzyl).
The crude 4-aroylpiperidines XI (R 3 =CH 3 or benzyl) are converted to the hydrobromides. Compound XI (R 3 =H) is acetylated.
Compound XI (R 3 =CH 3 , benzyl, or CH 3 CO) is dissolved in a suitable solvent, e.g., CHCl 3 or CCl 4 , and is brominated with Br 2 to produce the compound ##STR22## which, after recrystallization, is treated wtih NaOMe in MeOH. After addition of water and evaporation of MeOH, the compound ##STR23## may be extracted with ether. The crude compound XV is hydrolized in ethanol with concentrated hydrochloric acid to produce the compound ##STR24## Compound XVI (R 3 =CH 3 CO) is precipitated with water. After alkalization, extraction with CHCl 3 or benzene, and drying of
the solution with Na 2 SO 4 , compound XVI (R 3 =CH 3 or benzyl) can be precipitated with an acid addition salt.
The novel intermediate VII is then prepared from XVI by:
II A. removal of the acetyl group (XVI, R 3 =CH 3 CO) using 5-N HCl. Other strong mineral acids may also be used.
II B. selective hydrogenolysis over palladium catalyst of the benzyl group (XVI, R 3 = benzyl)
II C. demethylation (XVI, R 3 = CH 3 ) with ethyl chloroformate, followed by acid hydrolysis.
In more detail, the starting benzoylpiperidine II is synthesized according to Duncan et al., Med. Chemistry 13, (1), 1 (1970), e.g., by a Friedel-Crafts reaction of ##STR25## and a suitable known RR 1 -substituted benzene in a suitable solvent, e.g., nitrobenzene or an excess of the reacting compound RR 1 -benzene itself, to produce a compound of the formula XI, whereupon the Ac-group is removed with 5-N HCl. In reaction a), the benzoylpiperidine II is reacted with compound III in a suitable solvent, which may be a non-polar solvent, such as benzene or xylene, or a polar solvent, e.g, dimethylformamide or butylacetate.
The reaction a) is preferably performed in the presence of an acid-binding agent such as triethylamine, K 2 CO 3 , and advantageously but not necessarily in an autoclave at 75°-150° C.
After the coupling reaction, the products are generally treated with water or 1-N NaOH and extracted with ether, methyl-butyl ketone, or the like. From the dried solution, the hydrobromides or hydrochlorides may be precipitated and recrystallized. Even the crude product may be used for further reaction, if desired.
The acid salt, e.g., hydrobromide, is dissolved in a suitable solvent, e.g., carbon tetrachloride or chloroform, and brominated with Br 2 to produce compound V, which without further purification can be heated with sodium methoxide in methanol. After addition of water and evaporation of the solvent, compound V may be extracted with ether. The crude compound is hydrolized in ethanol with concentrated hydrochloride acid and, after alkalization, extraction with ether and drying of the solution with sodium sulfate, the compound I can be precipitated as a salt, preferably with a pharmaceutically acceptable acid, e.g., hydrochloric or hydrobromic acid, oxalic acid, maleic acid, citric acid, tartaric acid, or the like. One acid salt, even if not pharmaceutically acceptable, can be readily converted to another salt which is pharmaceutically acceptable in known manner, if desired.
DETAILED DESCRIPTION OF THE INVENTION
The following Preparations and Examples are given by way of illustration only.
PREPARATION 1: 1-ACETYLISONIPECOTIC ACID AND ITS ACID CHLORIDE
A solution of 64.6 g (0.5 mole) of isonipecotic acid in 200 ml of acetic anhydride was refluxed for two hours and allowed to stir at room temperature overnight. The solution was concentrated and the residue which remained was triturated in ether. The solid was collected by filtration and recrystallized from isopropyl alcohol - isopropyl ether. Yield 58.2 g., melting point 178°-182° C. (Reference: Duncan, R.L. et al., J. Med. Chem., 13, (1), 1 (1970). This compound is converted to its acid chloride by the following detailed procedure:
To 400 ml of SOCl 2 was added 68.9 g (0.4 mole) of 1-acetylisonipecotic acid, which dissolved. The acid chloride precipitated from solution and 1 liter of pentane was added. The mixture was filtered and the solid residue was washed several times with pentane. The solid was dried. Yield 72 g.
PREPARATION 2: 1-ACETYL-4-(p-FLUOROBENZOYL)PIPERIDINE
To a stirring mixture of 55.0 grams (0.41 mole) of aluminum chloride in 100 ml. fluorobenzene was slowly added forty grams (0.21 mole) of 1-acetyl-isonipecotoyl chloride. After the addition was complete, the mixture was refluxed for 1 hour. The mixture was poured onto ice and the two resulting layers were separated. The aqueous layer was extracted with chloroform and the extracts were added to the fluorobenzene. The organic solution was dried over sodium sulfate and filtered. The filtrate was concentrated under reduced pressure and the residue was a crystalline solid. The reaction product was purified by recrystallization in ligroin-isopropylether. Yield: 38.2 grams; melting point: 76°-80° C. (Reference: Duncan, R. L., et al., J. Med.Chem. 13 (1) 1 (1970).
In exactly the same manner, the following additional compounds are prepared, starting only from the appropriate benzene:
1-acetyl-4-benzoylpiperidine from benzene itself;
1-acetyl-4-(p-methoxybenzoyl)piperidine from methoxybenzene;
1-acetyl-4-(p-bromobenzoyl)piperidine from bromobenzene;
1-acetyl-4-(p-chlorobenzoyl)piperidine from chlorobenzene; and
1-acetyl-4-(p-methylbenzoyl)piperidine from methylbenzene.
PREPARATION 3: 4-(p-FLUOROBENZOYL)PIPERIDINE HYDROCHLORIDE (Compound II)
A solution of fifty g. (0.2 mole) of 1-acetyl-4-(p-fluorobenzoyl)piperidine in 200 ml of 6 N HCl was refluxed for twelve hours. The cooled solution was extracted twice with ether. The aqueous solution was made basic (NaOH) and then extracted with benzene. The benzene extracts were dried (Na 2 SO 4 ) and filtered. The filtrate was concentrated under reduced pressure, and the residual oil was converted to the hydrochloride salt. The crude product was recrystallized from isopropyl alcohol. Yield 42 g., melting point 223°-25° C. (Reference: Duncan, R. L., et al., J.Med.Chem., 13 (1) 1 (1970).
In exactly the same manner, the following additional compounds are prepared by substituting the appropriate starting 1-acetyl-4-benzoylpiperidine from Preparation 2 in the procedure of Preparation 3:
______________________________________ m.p.______________________________________4-benzoylpiperidine hydrochloride 222-224° C4-(p-methoxybenzoyl)piperidine hydrochloride 255-258° C4-(p-bromobenzoyl)piperidine hydrochloride 228-230° C4-(m-trifluoromethylbenzoyl)piperidine hydrochloride4-(3-trifluoromethyl-4-chlorobenzoyl)piperidinehydrochloride 238-240° C4-(p-methylbenzoyl)piperidine hydrochloride 260-263° C______________________________________
and so on.
PREPARATION 4: 4-(p-FLUOROBENZOYL)-1-[4,4-(DI-p-FLUOROPHENYL)-BUTYL]PIPERIDINE HYDROBROMIDE (Compound IV)
A stirred mixture of 6.2 g (0.03 mole) of 4-(p-fluorobenzoyl)-piperidine (Compound II), 9.8 g (0.035 mole) of 4-chloro-1,1-(di-p-fluorophenyl)butane, 10 grams of anhydrous sodium carbonate, 0.15 g. of potassium iodide, and 250 ml. of isobutyl acetate was heated at reflux for 85 hours. The mixture was filtered and the filtrate was concentrated under vacuum. The residual oil was dissolved in ether and the hydrobromide was precipitated with ethanolic HBr. The reaction product was purified by recrystallization from ethanolether. Yield: 12.8 g, melting point 147° C.
Additional intermediates of this type IV, which can be produced in the same manner from the respective suitable starting materials, are set forth in Table II.
PREPARATION 5: 4-BROMO-4-(p-FLUOROBENZOYL)-1-[4,4-(DI-p-FLUOROPHENYL)BUTYL]-PIPERIDINE HYDROBROMIDE
A solution of 10.6 g (0.02 mole) of 4-(p-fluorobenzoyl)-1-[4,4-(di-p-fluorophenyl)butyl]piperidine hydrobromide in fifty ml. of chloroform was treated with 3.4 ml. of bromine. The reaction mixture was allowed to stand for 17 hours at room temperature. The solvent and excess bromine were removed under reduced pressure. The residue was dissolved in a solution containing 6.5 g. phenol in 100 ml. of methanol, and the solution was diluted with anhydrous ether precipitating the 4-bromo-4-(p-fluorobenzoyl)-1-[4,4-(di-p-fluorophenyl)butyl]piperidine hydrobromide. The reaction product was purified by recrystallization from methanol-ether. Yield: 10 g.; melting point 160° C.
Additional intermediates of this same type are produced in the same manner from the appropriate starting materials.
PREPARATION 6: 2-(p-FLUOROPHENYL)-6-[4,4-(DI-p-FLUOROPHENYL)BUTYL]-2-METHOXY-1-OX-6-AZASPIRO[2.5]OCTANE
A solution of ten grams (0.019 mole) of 4-bromo-4-(p-fluorobenzoyl)-1-[4,4-(di-p-fluorophenyl)butyl]piperidine hydrobromide in 35 ml. of methanol was added to a solution of sodium methoxide prepared from the three grams of sodium in 35 ml. of methanol. The mixture was heated under reflux for 4 hours, and most of the methanol was removed under reduced pressure. Water was added, and the remaining methanol was removed under reduced pressure. The aqueous layer was extracted with ether, and the extracts were dried over sodium carbonate. Removal of the ether gave crude 2-(p-fluorophenyl)-6-[4,4-(di-p-fluorophenyl)butyl]-2-methoxy-1-oxo-6-azaspiro [2.5] octane. Yield: 6.7 g.
Additional intermediates of this same type are produced in the same manner from the appropriate starting materials.
EXAMPLE 1: 4-(p-FLUOROBENZOYL)-4-HYDROXY-1-[4,4-(DI-p-FLUOROPHENYL)-BUTYL]PIPERIDINE OXALATE (Compound I)
A mixture of 4.8 g. (0.01 mole) of 2-(p-fluorophenyl) -6-[4,4-(di-p-fluorophenyl)butyl]-2-methoxy-1-oxo-6-azaspiro [2.5] octane, five ml. of concentrated hydrochloric acid and thirty ml of ethanol was stirred for ten minutes. Water was added, and most of the ethanol was removed under reduced pressure. Neutralization with sodium carbonate and extraction with chloroform gave crude 4-(p-fluorobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine. The obtained base was dissolved in ethanol and the oxalate was precipitated by addition of oxalic acid dissolved in ethanol. The reaction product was purified by recrystallization from ethanol. Yield: 4.4g; melting point 214° C.
Additional end products of this type I, which can be produced in the same manner from the respective suitable starting materials, are set forth in Table III.
EXAMPLE 2: 4-(p-FLUOROBENZOYL)-4-PROPIONYLOXY-1-[4,4-(DI-p-FLUOROPHENYL)-BUTYL]PIPERIDINE HYDROCHLORIDE
Two grams of the crude base from EXAMPLE 1 is dissolved in twenty ml. of propionic anhydride and a catalytic amount of 4-dimethylaminopyridine is added. After 10 hours at 20° C., the solvent is evaporated. The remainder is dissolved in ethylacetate-ether and treated with ethanolic HCl. The obtained hydrochloride is recrystallized from ethanol. The melting point is 246-248° C.
EXAMPLE 3: 4-(p-METHYLBENZOYL)-4-HYDROXY-1-[4,4-(DI-p-FLUOROPHENYL)BUTYL]PIPERIDINE HYDROCHLORIDE
This compound is synthesized in the same manner as given in EXAMPLE 1 starting from 4-(p-methylbenzoyl)piperidine instead of 4-(p-fluorobenzoyl)piperidine. The hydrochloride has the melting point 120°-122° C.
EXAMPLES 4 -11
In the same manner, as shown in the following Table III, the following end products are produced, starting only with the suitable selected starting benzoylpiperidine II or, as shown in the following EXAMPLE 12, starting from the suitable selected 4-benzoyl-4-hydroxypiperidine VII of PREPARATION 10:
4. 4-(p-Methoxybenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidine oxalate.
5. 4-(p-Bromobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidine hydrochloride.
6. 4-(m-Trifluoromethylbenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine oxalate.
7. 4-(3-Trifluoromethyl-4-chlorobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine hydrochloride.
8. 4-Benzoyl-4-hydroxy-1-[4,4 -(di-p-fluorophenyl butyl]-piperidine hydrochloride.
9. 4-(p-Chlorobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidinehydrochloride.
10. 4-(p-Fluorobenzoyl)-4-decanoyloxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidine hydrochloride.
This compound is obtained following the procedure of EXAMPLE 2 by substituting decanoic acid anhydride or chloride for propionic anhydride.
11. 4-(p-Fluorobenzoyl)-4-nonadecanoyloxy-1-[4,4-(di-p-fluorphenyl)-butyl]piperidine hydrochloride.
This compound is obtained following the procedure of EXAMPLE 2 by substituting nonadecanoic acid anhydride or chloride for propionic anhydride.
PREPARATION 7: 1-ACETYL-4-BROMO-4-(p-FLUOROBENZOYL)PIPERIDINE
A solution of 36 g. (0.145 mole) of 1-acetyl-4-(p-fluorobenzoyl)piperidine in 175 ml of chloroform was treated with fifteen ml. of bromine. The mixture was heated at reflux for one hour and was then allowed to stand overnight at room temperature 1-Acetyl-4-bromo-4-(p-fluorobenzoyl)piperidine hydrobromide precipitated and was collected by filtration and recrystallized from ethanol. Yield: 40.6 g., melting point 156°-159° C. In exactly the same manner, additional intermediates of this type are produced by substituting the selected starting materials from PREPARATION 2 in the procedure of PREPARATION 7.
PREPARATION 8: 6-ACETYL-2-(p-FLUOROPHENYL)-2-METHOXY-1-OX-6-AZASPIRO [2.5] OCTANE
32.8 g (0.1 mole) of 1-acetyl-4-bromo-4-(p-fluorobenzoyl)piperidine was added to a solution of sodium methoxide prepared from 12.8 g. of sodium in 400 ml. of methanol. The mixture was heated at reflux for 2 hours. Water was added and the methanol was removed under reduced pressure. The aqueous layer was extracted with ether and the extracts were dried over sodium carbonate. Removal of the ether gave crude 6-acetyl-2-(p-fluorophenyl)-2-methoxy-1-ox-6-azaspiro [2.5] octane. Yield: 24.2 grams. In exactly the same manner, additional intermediates of this type are produced by substituting the selected starting materials from PREPARATION 7 in the procedure of PREPARATION 8.
PREPARATION 9: 1-ACETYL-4-(p-FLUOROBENZOYL)-4-HYDROXYPIPERIDINE
A mixture of 21.3 g. (0.076 mole) of 6-acetyl-2-(p-fluorophenyl)-2-methoxy-1-ox-6-azaspiro [2.5] octane, 140 ml. of ethanol and 27 ml. of concentrated hydrochloric acid was stirred for fifteen minutes. Water was added. The solid which precipitated was collected by filtration and recrystallized from ethanol-ether giving nineteen grams of 1-acetyl-4-(p-fluorobenzoyl)-4-hydroxy-piperidine. Melting point: 146°-149° C. In exactly the same manner, additional intermediates of this type are produced by substituting the selected starting materials from PREPARATION 8 in the procedure of PREPARATION 9.
PREPARATION 10: 4-(p-FLUOROBENZOYL)-4-HYDROXY-PIPERIDINE HYDROCHLORIDE (Compound VII)
A solution of 18.6 grams (0.07 mole) of 1-acetyl-4-(p-fluorobenzoyl)-4-hydroxy-piperidine in sixty ml. of 5-N HCl was refluxed for 15 hours. Nost of the water was removed under reduced pressure. Ethanol was added and the solution was cooled. The solid which precipitated was collected by filtration and recrystallized from ethanol giving 16.5 grams of 4-(p-fluorobenzoyl)-4-hydroxy-piperidine hydrochloride. Melting point: 241°-243° C.
In exactly same manner, the following additional compounds are prepared by substituting the appropriate starting 1-acetyl-4-benzoyl-4-hydroxypiperidine from PREPARATION 9 in the procedure of PREPARATION 10:
4-benzoyl-4-hydroxypiperidine hydrochloride
4-(p-methoxybenzoyl)-4-hydroxupiperidine hydrochloride
4-(p-bromobenzoyl)-4-hydroxypiperidine hydrochloride
4-(m-trifluoromethylbenzoyl)-4-hydroxypiperidine hydrochloride
4-(3-trifluoromethyl-4-chlorobenzoyl)-4-hydroxypiperidine
4-(p-chlorobenzoyl)-4-hydroxypiperidine hydrochloride
4-(p-methylbenzoyl)-4-hydroxypiperidine hydrochloride,
and so on.
EXAMPLE 12: 4-(p-FLUOROBENZOYL)-4-HYDROXY-1-[4,4-(DI-p-FLUOROPHENYL)BUTYL]PIPERIDINE OXALATE AND HYDROCHLORIDE (Compound I)
A stirred mixture of eleven grams (0.05 mole) of 4-(p-fluorobenzoyl)-4-hydroxypiperidine, 16.9 grams (0.06 mole) of 4-chloro-1,1-(di-p-fluorophenyl)butane, twenty grams of anhydrous potassium carbonate, and 300 ml. of isobutylacetate was heated at reflux for 60 hours. The mixture was filtered and the filtrate was concentrated under vacuum. The residual oil as dissolved in ethanol and the oxalate was precipitated with oxalic acid dissolved in ethanol. The crude product was purified by recrystallization in ethanol. Yield: fifteen grams; melting point 214° C. The compound is converted to its hydrochloride salt in conventional manner by neutralization and acidification with HCl according to the general procedure given in EXAMPLE 2.
In the same manner, the following additional compounds of Type I and their acid addition salts, e.g., their hydrochlorides, oxalates, hydrobromides, citrates, or tartrates, are prepared by employing the selected starting 4-benzoyl-4-hydroxypiperidine from PREPARATION 10 in the procedure of EXAMPLE 12:
4-(p-Methylbenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine
4-(p-Methoxybenzoyl)-4hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidine
4-(p-Bromobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine
4-(m-Trifluoromethylbenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]piperidine.
4`-(3-Trifluoromethyl-4-chlorobenzoyl)-4-hydroxy-1-(4,4(di-p-fluorophenyl)butyl]piperidine.
4-Benzoyl-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]-piperidine.
4-(p-Chlorobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl]piperidine.
EXAMPLE 13: 4-(p-METHYLBENZOYL)-4-DIMETHYLACETOXY-1-[4,4-(DI-p-FLUOROPHENYL)BUTYL]PIPERIDINE HYDROCHLORIDE
In the same manner as given in EXAMPLE 2, this product is produced from the product of EXAMPLE 3 and dimethylacetylchloride or anhydride.
In the same manner as given in EXAMPLES 2, 10, 11, and 13, additional 4-acyloxy compounds of any Type I compounds, as set forth in Table III, are produced from the appropriate 4-hydroxy compound and the selected acyl halide or anhydride, including the acetates, propionates, butyrates, caproates, valerates, octanoates, decanoates, dodecanoates, hexadecanoates, octodecanoates, nonadecanoates, and the like.
Moreover, in addition to the substituent R 1 shown in Table III, the same and/or additional R substituents may be present in different and varying ring positions, e.g., in a different position or as the second substituent in the benzene ring in addition to the R 1 substituent already present therein, such as fluoro, bromo, methyl. methoxy. trifluoromethyl, ethyl, chloro, amyl, ethoxy, amyloxy, or the like, depending only upon a judicious selection of the ring positions and substituents present in a starting disubstituted benzene compound to be employed in PREPARATION 2, as will be apparent and within the ability of anyone skilled in the art, including the acid addition salts, e.g., the hydrochlorides, hydrobromides, oxalates, citrates, or tartrates of such compounds.
PHARMACOLOGY
Representative compounds of the present invention have been subjected to a series of pharmacological tests, in which the new compounds were compared with Haloperidol, Chlorpromazine, and Pimozide, havin the formulas previously given. The pharmacological tests used are suitable for measuring:
1. Inhibition of aggressive behaviour-in-male mice
2. Inhibition of climbing-in-mice (inhibition of exploratory behaviour)
3. Amphetamine antagonism-in-rats (antipsychotic effect)
4. Cataleptogenic effect-in-rats (measure of extrapyramidal side effects)
5. Inhibition of conditioned behaviour-in-rats These tests 1-5 have been described, and the importance of coordinating the compounds with these tests and the activities shown thereby is described in detail in the following literature:
1. Inhibition of Aggression
Valzelli, L. in Aggressive Behaviour, Eds. Garattini and Sigg, p. 70 (1969), Valzelli, L. in Neuro-Psycho-Pharmacology, Ed. Brill, p. 781 (1967).
2. Inhibition of Exploratory Behaviour (Climbing)
van Rossum, J. M. et al. in The Neuroleptics, Modern Problems of Psyco-Psychiatri, Vol. 5, p.26 (1970), Kneip, P. in Arch. Int. Pharmacodyn, 126, 238 (1960), Sandberg, S. in Arzneimittelforschung, 9, 203 (1958).
3. Amphetamine Antagonism
Randrup, A. et al. in Acta Pharmacol. (Kph), 20, 145 (1963), Randrup, A. in The Neuroleptics, Modern Problems of Psycho-Psychiatri, Vol. 5, p. 60 (1970).
4. The Cataleptogenic Effect
Rossum, J.M. et al. in The Neuroleptics, Modern Problems of Psycho-Psychiatry, Vol. 5, p. 26 (1970), Stille, C. in Schweiz. Med. Wochenschrift 99,1645 (1969),
5. Inhibition of Conditioned Avoidance Response
"Neuroleptics characteristically interrupt the response to the warning stimulus (avoidance) without at the same time interrupting the response to the noxious stimulus (escape) which follows it" An Introduction to Psycho-Pharmacology, Eds. Rech and Moore, New York, p. 264 (1971), Courvoisier, S. et al. in Arch. Int. Pharmacodyn., 92, 305 (1953) Jacobsen, E. in Psychotrophic Drugs, Eds. Garattini, Ghetti, Amsterdam, p. 119 (1957) Jacobsen and Sonne in Acta Pharmacol. & Toxicol. 11, pp. 135-147 (1955).
The results are tabulated in Table I.
TABLE I__________________________________________________________________________ 5 x) 1 2 3 Inhib. of Inhib. of Inhib. of Amphetamine 4 conditioned aggression expl. activity Antagonism Catalepsy avoidanceR.sub.1 R.sub.2 R 4 hours 4 hours 4 hours 4 hours 4 hours__________________________________________________________________________Haloperidol 0.8 0.7 0.06 0.11 0.2Chlorpromazine 0.5 0.9 1.6 3.6 5.2Pimozide 0.3 6.8 0.13 2.0 0.6F H H 1.5 10 0.2 >20 2.2CH.sub.3 H H 2.3 20 2.0 >20 20F --COC.sub.2 H.sub.5 H 1.7 20 2.0 >50 20__________________________________________________________________________ x) The figures refer to the numbers given to these pharmacological tests in the text.
In special experiments on monkeys, the new compounds produce very few or no extrapyramidal side effects at all in contrast to, e.g., haloperidol and chlorpromazine, which induce such side effects readily and at low doses.
Furthermore, the duration of activity of the new compounds is around 24 hours, a figure which is comparable to that for pimozide, whereas the duration of action of haloperidol and chlorpromazine is around 6-8 hours.
The actue toxicity of the new compounds according to the invention determined orally in conventional manner, is rather low, ranging from 350 mg/kg to more than 800 mg/kg. For comparison it may be mentioned that the acute toxicity for haloperidol is 70 mg/kg and for chlorpromazine 280 mg/kg.
The antipsychotic effect as shown in Test No. 3 is further confirmed by the blocking of apomorphineinduced emesis in dogs.
On account of these favorable properties, the new compounds are indicated for the treatment of certain mental disturbances in humans, for instance schizophrenia, mania, anxiety, agony, and aggression. Their general tranquilizing properties also make the new compounds suitable for veterinary applications.
The high order of activity of the active agents of the present invention has been evidenced by tests in lower animals and representative of these are reported herein.
The novel compounds are preferably used in the form of their pharmaceutically-acceptable acid addition salts, e.g., their hydrochlorides, hydrobromides, or the like. The salt form is als the best form for pharmaceutical formulations. Innumerable other pharmaceutically-acceptable acid addition salts can be prepared from the hydrochlorides via the free bases in conventional manner. For oral use, the compounds are usually administered as tablets in which they are present together with usual pharamceutical carriers, excipients, binders, and the like. For example, tablets may be prepared conventionally by compounding one of the new compounds, preferably in the form of an acid addition salt thereof, with customary carriers and adjuvants, e.g., talc, magnesium stearate, starch, lactose, gelatin, gums, and the like.
In their most advantageous form, then, the compositions of the present invention will contain a non-toxic pharmaceutical carrier in addition to the active ingredient of Formula I. Exemplary carriers are: solids-lactose, magnesium stearate, calcium stearate, starch, terra alba, dicalcium phosphate, sucrose, talc, stearic acid, gelatin, agar, pectin, acacia, or the like; liquids - peanut oil, sesame oil, olive oil, water, or the like. The active agents of the invention can be most conveniently administered in such compositions containing about 0.01 to 67 percent, preferably 0.04 to 12.15 percent, by weight of the active ingredient. Such formulations are representatively illustrated in U.S. Pat. No. 3,402,244.
A wide variety of pharmaceutical forms suitable for many modes of administration and dosages may be employed. For oral administration the active ingredient and pharmaceutical carrier may, for example, take the form of a granule, pill tablet, lozenge, elixir, syrup, or other liquid suspension or emulsion; for parenteral administration, the composition may be a sterile solution; and for rectal administration, a suppository.
The method of using the compounds of the present invention comprises internally administering a compound of Formula I, usually in the form of a non-toxic, pharmacologically acceptable acid-addition salt, and preferably admixed with a pharmaceutical carrier, for example, in the form of any of the above-mentioned compositions, or filled into a capsule, to alleviate psychotic conditions and symptoms thereof in a living animal body, for example, the aforementioned schizophrenic, manic, anxiety, agony, and aggressive states. The compounds and their non-toxic salts, especially the hydrochlorides, may be advantageously employed in amounts approximating those employed for any of the three clinically-useful compounds used for comparative testing as reported herein. Illustratively, they may be used in an amount of from about 0.1 to 200 milligrams per unit dose, preferably from about 2.5 to 50 milligrams for an oral dose, while parenteral dosages are usually less and ordinarily about one-half the oral dose so that the preferred parenteral unit dosage will be about one to 25 milligrams. The unit dose is preferably given a suitable number of times daily so that the daily dose may vary from 0.3 to 600 milligrams. Preferred daily dosages will vary from about 7.5 to 150 milligrams (oral) to about three to 75 milligrams (parenteral). However, these compounds are subject to wide variations in optimum daily and unit dosages, due to patient body weight, condition, and ancillary factors and the invention should therefore not be limited by the exact ranges stated. The exact dosage, both unit and daily, will of course have to be determined according to established medical principles. In addition, the active ingredients of the present invention or compositions containing the same may either be administered together with or include other physiologically active materials and/or medicaments, e.g., buffering agents, antacids, sedatives, stimulants, anticholinergics, analgesics, or the like.
The following formulations are representative for all of the pharmacologically active compounds of the invention, but have been particularly designed to embody as active ingredient the particular compound embodied therein, and especially a pharmacologically acceptable salt thereof, for example, its tartrate, hydrochloride, hydrobromide, fumarate, or like pharmacologically acceptable salt.
As already stated, for oral use the compounds are usually administered as tablets, although other forms may be employed. Tablets may be made by compounding one of the compounds of the invention, preferably as an acid-addition salt, with customary carriers and adjuvents, e.g., talc, magnesium stearate, starch, lactose, gelatin, gums, or the like.
The following is a suitable tablet formulation:
0.1 - 1g of 4-(p-Fluorobenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)-butyl[-piperidine oxalate
9 g of potato starch
1 g of colloidal silica
2 g of talc
0.2 g of magnesium stearate
2.5 g of 5% aqueous solution of gelatin.
This mixture is made up into 100 tablets, each containing 1-10 mg of the active component.
The hydrochloride or other acid addition salts are readily soluble in water-isopropanol, which makes them particularly useful, since it enables the new compounds to be administered parenterally by injection.
For injection, the following solution is suitable:
5 - 500 mg of 4-(p-Methylbenzoyl)-4-hydroxy-1-[4,4-(di-p-fluorophenyl)butyl]-piperidine hydrochloride
dissolved in fifty milliliters of water and fifty milliliters of isopropanol containing 0.6 grams of sodium chloride.
The resulting solution is filled into ampules, each containing two milliliters of solution and thus 0.1 -10 milligrams of the active compound. The ampules are sterilized in the usual manner.
The pharmacologically active compounds provided by the present invention may also be administered successfully by embodying an effective quantity thereof in an injectable emulsion or suspension for injection into an animal body, in oral powders, suspension or syrups, and in other acceptable dosage forms.
Although very small quantities of the active materials of the present invention are effective when minor therapy is involved or in cases of administration to subjects having a relative low body weight, unit dosages are usually five milligrams or above and preferably twenty-five, fifty or one-hundred milligrams or even higher, depending of course upon the emergency of the situation and the particular result desired,. To repeat, the exact individual dosages as well as daily dosages in a particular case will of course be determined according to established medical principles and under the supervision of the physician or verterinarian involved.
Representative compounds of the invention, including important intermediates for their production, are set forth in Tables II, III and IV.
Various modifications in the compounds, compositions, and methods of the invention will be apparent to one skilled in the art and may be made without departing from the spirit or scope thereof, and it is therefore to be understood that the invention is to be limited only by the scope of the appended claims.
TABLE II______________________________________ ##STR26##Intermediate Compound IVR R.sub.1 Salt Mp, ° C.sup.a)______________________________________H 4-CH.sub. 3 (COOH).sub.2 217-218H 4-OCH.sub. 3 (COOH).sub.2 199-200H 4-F (COOH).sub.2 228-229H 4-Br HBr 145-147H 3-CF.sub. 3 HBr 191-1924-Cl 3-CF.sub. 3 HCl 195-196______________________________________ .sup.a) Melting points are uncorrected
TABLE III______________________________________ ##STR27##End Product IR R.sub.1 R.sub.2 Salt Mp, ° C.sup.a)______________________________________H 4-CH.sub. 3 H HCl 120-122H 4-OCH.sub. 3 H (COOH).sub.2 192-195H 4-F H (COOH).sub.2 214-216H 4-Br H HCl 165-167H 3-CF.sub.3 H (COOH).sub.2 152-1554-Cl 3-CF.sub.3 H HCl 238-240H 4-F COC.sub.2 H.sub.5 HCl 246-248______________________________________ .sup.a) Melting points are uncorrected
TABLE IV______________________________________ ##STR28##Intermediate Compound VIIR R.sub.1 Mp, ° C.sup.a)______________________________________H 4-CH.sub. 3 232-235H 4-OCH.sub. 3 218-220H 4-F 241-243H 4-Br 246-2484-Cl 3-CF.sub. 3 250 decomp.H H 230-233H 4-Cl 205-208H 3-CF.sub. 3 236______________________________________ .sup.a) Melting points are uncorrected | Novel 4,4-diphenylbutyl-1-(4-benzoyl-4-hydroxy or acyloxy)-piperidines and acid addition salts thereof, useful as central depressants, e.g., neuroleptics (anti-psychotics), are disclosed. Methods of making same, pharmaceutical compositions thereof, a method of treating therewith, and important and novel intermediates for the production thereof, namely, 4-benzoyl-4-hydroxypiperidines, are also disclosed, as well as 4-benzoyl-1-(4,4-diphenylbutyl)-piperidines, which are also useful intermediates. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is an application filed under 35 U.S.C. § 111(a), claiming benefit pursuant to 35 U.S.C. §§ 119-120 of the filing dates of the following Provisional Applications:
Ser. No. 60/401,758 filed on Aug. 8, 2002; Ser. No. 60/429,064 filed on Nov. 26, 2002; and Ser. No. 60/474,924 filed on Jun. 3, 2003.
Provisional Application Ser. Nos. 60/401,758, 60/429,064 and 60/474,924 are incorporated herein by reference for all they disclose.
BACKGROUND OF THE INVENTION
[0005] 1. Technical Field of the Invention
[0006] The present invention is directed to headgear comprising slow recovery viscoelastic polyurethane foam with a surface impregnation of silicone, and more specifically, to headgear comprising a shell to dissipate a portion of a force impacting on the headgear and a slow recovery viscoelastic polyurethane foam that absorbs the remainder of the impact force
[0007] 2. Description of the Related Art
[0008] Head injuries are a leading cause of death and disability in the United States. Data collected by the Centers for Disease Control demonstrate that, on average, three hundred thousand sports-related brain concussions occur in the United States each year. Children under the age of fourteen have a greater risk for concussions than do adults. Teenagers that suffered two or more “big hits” to the head can suffer long-term damage to their thinking abilities. Twenty percent of teenagers that have suffered multiple concussions have continuous headaches and suffer sleep and concentration disorders. The damage from concussions can vary from mild, which is completely reversible, to severe which can lead to coma or death.
[0009] A concussion is an injury to the brain cells resulting from trauma to the head. Loss of consciousness is not necessary for a head injury to be considered a concussion. Concussions are graded in severity on a scale of Grade One (mild) to Grade Three (severe). Concussions are considered to be Grade One when there is no loss of consciousness and symptoms last less than fifteen minutes. A Grade Two concussion is when there is no loss of consciousness, with symptoms lasting longer than fifteen minutes. A Grade Three concussion is when there is any loss of consciousness.
[0010] Though the incidence of concussions at the amateur levels of ice hockey are not known, it is thought to be a fairly common occurrence. A hockey study from Canada surveying players throughout all professional levels in the sport demonstrated that at least sixty percent of the players suffered at least one concussion in their career. From Oct. 1, 2001 through Dec. 31, 2001, there were sixty-seven concussions in the National Hockey League. The total number of concussions in the National Hockey League exceeds one hundred per year for a league that has six hundred players.
[0011] The governing bodies at every level of amateur and profession ice hockey mandate the use of helmets. Typically, helmets comprise a rigid outer shell and an energy absorbing liner. The helmet shell functions to: (i) maintain the energy absorbing liner in position upon impact, (ii) prevent penetration of sharp objects, and (iii) dissipate the impact's energy prior to it reaching the energy absorbing liner.
[0012] The helmet shell prevents injury to the head by decreasing the impact force to the brain. Of all the sports requiring certification of their helmets, ice hockey has the lowest certification standards. Helmet shells are typically made from a composite material or a thermoplastic material. Thermoplastic helmet shells bend to absorb impact energy. Thermoplastic helmet shells are easy to mold and color, and are inexpensive to manufacture. Thermoplastic helmet shells deform more and are less rugged than composite helmet shells. Most reinforced thermoset resin shells are considered stronger than typical injection molded plastic shells. Thermoset resin shells are not considered viscoelastic. This means that the thermoset resin shell does not indent with the application of a force. In general, if the thermoset resin shell indents, the impact force is more concentrated in the zone of indentation and less dissipated throughout the surface of the thermoset resin shell.
[0013] A composite helmet shell is more rugged and deforms less than the thermoplastic helmet shell. A composite helmet shell delaminates to absorb impact energy. Delamination is microscopic separation of the fiber layers. A composite is a mixture of components whose combined physical strength is greater than their individual strength. Composite helmet shells are usually made out of epoxy resin and reinforced with fiberglass, carbon or Kevlar. Reinforcing resin with fibers increases the tensile strength by several fold. The different fibers used within the composite produce different characteristics (tensile strength, compressive strength, flexural strength and abrasion resistance). Motorcycle crash helmets demonstrate the state-of-the-art. Motorcycle helmet shells are made of reinforced epoxy resins and are designed to withstand high-speed impact.
[0014] Injection molded plastic helmet shells vary significantly in strength, weight and are viscoelastic. ABS is the standard type of plastic used for injection molded helmet shells. In some types of helmet shells, injection molded plastic can be very strong, e.g., football helmets or lacrosse helmets.
[0015] Energy absorbing liners are made from either open-cell foam or closed-cell foam. Energy absorbing liners compress as they absorb energy. The purpose of the energy absorbing liner is to decrease the energy of the impact force. This is called impact attenuation. If an egg were dropped onto an energy absorbing liner, it would either crack or stay whole, based on the amount of energy absorbed by the energy absorbing liner. Open-celled foam will rebound after it is compressed from an impact. Polyvinyl padding is a type of celled foam commonly used in hockey helmets as an energy absorbing liner. Expanded polystyrene (EPS) is a type of closed-cell foam that is the most commonly energy absorbing liner used today in hockey helmets. EPS is a type of STYROPOAM used for packaging protection. EPS is compressed and crushed as it absorbs energy. While EPS attenuates impact force well and is considered the “gold standard” in the helmet market, impacts produce permanent damage to the EPS material. Minor impacts to the helmet shell cause microscopic cracks in the EPS. Which can seriously destroy its impact attenuation performance.
[0016] Most urethane foams are elastic in that the foam deflects under a load, and return a force to the load that is equal to the deflection of the elastic material multiplied by its stiffness. When pressure is applied to common urethane foam, like a spring, the foam deflects and returns a force that is proportional to the amount of deflection. Areas of greatest deflection (i.e., greatest pressure) receive the greatest return force. These pressure hot spots can restrict blood circulation to portions of the body.
[0017] Viscoelastic foams have both viscous and elastic response properties. The viscous response property evenly distributes a load, and the elastic response property allows the foam to support a static load. “Viscous” refers to a fluid response that flows away from the applied load or applied force, in that the fluid redistributes the applied load or applied force. Viscoelastic materials redistribute the applied load or applied force away from the point of contact.
[0018] Slow recovery viscoelastic polyurethane foam molds, shapes, and adjusts to the surface it is in contact with the application of heat. In athletic headgear, for example, the athlete's head causes the application of heat to the slow recovery viscoelastic polyurethane foam. CONFOR foam displays this characteristic greater than other viscoelastic polyurethane foams. Typically, athletic headgear comprises an outer shell and an inner energy absorbing liner for absorbing impacts suffered during the course of an athletic contest. An energy absorbing liner comprising viscoelastic polyurethane foam absorbs energy transferred from the outer shell, if the head represents the final transfer point of the impact energy. Naturally, the viscoelastic polyurethane foam should absorb as much impact energy as possible prior to being completely compressed. Of course, the greater the surface area of the viscoelastic polyurethane foam contacting the skull, the greater the energy dissipation and absorption there will be prior to the viscoelastic polyurethane foam reaching maximum compression (bottoming out). The viscoelastic polyurethane foam should return to its pre-impact shape after the impact.
[0019] Ice hockey involves players reaching impact speeds greater than any other contact sport. The helmet shell used in ice hockey is different than the helmet shell in any other sport. For a helmet shell to be accepted by the hockey community, it must have a certain cosmetic appearance. The helmet shell must cover the forehead, temples, crown, and back of the head. Hockey players will not wear helmets that are overly large, or have the shape or appearance of a motorcycle crash helmet or football helmet. The plastic used in hockey helmet shells has obviously less impact resistance. In fact, the plastic used in some hockey helmet shells might even be considered an adornment (the clear fragile plastic now used in CCM x-ray helmets). Typically, hockey helmet shells have their least strength on the sides (temples) where the helmet shell loses its curvature, the openings are located for the ears and the energy absorbing liner is at its thinnest. Ice hockey helmet shells made of plastic are most vulnerable in this region.
[0020] Typical hockey helmets do not meet the same standard of protection that football or lacrosse helmets meet. The customary construction of ice hockey helmets uses helmet shell halves that slide together front to back. This interaction of the helmet shell halves is the primary adjustment in most helmets. The padding components are typically arranged to complement this action or at least not interfere with the adjustment. The current construction fails to keep the helmet secured on the head. Critically, hockey helmets typically do not fit humanoid head forms very well, and poor fit can dangerously compromise the function of the helmet.
SUMMARY OF THE INVENTION
[0021] The invention has been made in view of the above circumstances and to overcome the above problems and limitations of the prior art, and provides a helmet comprising a slow recovery viscoelastic foam with a surface impregnation of silicone to retard moisture absorption. The invention further provides a helmet comprising a shell that dissipates a portion of an impact force delivered to the helmet and a slow recovery viscoelastic foam that absorbs the remainder of the impact force.
[0022] Additional aspects and advantages of the invention will be set forth in part in the description that follows and in part will be obvious from the description, or can be learned by practice of the invention. The aspects and advantages of the invention can be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
[0023] A first aspect of the present invention provides a helmet for cushioning a head during a sudden impact, and the helmet comprises a helmet shell, and an energy absorbing protective liner fitted to an interior surface of the helmet shell. The energy absorbing protective liner includes a slow recovery viscoelastic material with surface impregnation of a waterproofing material. The energy absorbing protective liner can be formed from slow recovery viscoelastic polyurethane foam with silicone as the waterproofing material.
[0024] A second aspect of the present invention provides a helmet for cushioning a head during a sudden impact, and the helmet comprises a helmet shell and a plurality of energy absorbing protective pads arranged on an interior surface of the helmet shell. Each of the energy absorbing protective pads comprises a slow recovery viscoelastic material with surface impregnation of a waterproofing material. Each energy absorbing protective pad can be formed from slow recovery viscoelastic polyurethane foam with silicone as the waterproofing material. Advantageously, each of the energy absorbing protective pads can be shaped into pads of variable thickness and size.
[0025] A third aspect of the present invention provides a helmet for cushioning a head during a sudden impact, and the helmet comprises a helmet shell having a humanoid head shape, with lateral members at least partially disposed around a circumference of the helmet shell. The helmet further includes an energy absorbing protective liner fitted to an interior surface of the helmet shell, comprising a slow recovery viscoelastic material with surface impregnation of a waterproofing material. The energy absorbing protective liner can be formed from slow recovery viscoelastic polyurethane foam with silicone as the waterproofing material. The helmet shell has a thickness of at least 2 millimeters, and the lateral members are ticker than other portions of the helmet shell. The lateral members disperse an impact force from a point of contact to other portions of the helmet shell. Each of the lateral members is comprised of an upper lateral member and a lower lateral member, and the upper lateral member and the lower lateral member are separated by a lateral channel. The helmet shell also includes a strap attachment member, and the lower lateral member is angled towards the location where the strip attachment member is disposed on the helmet shell. The helmet shell can be manufactured from injection molded plastic, or from pressure molded thermoset resin reinforced with glass fiber, KEVLAR fiber or carbon fiber. The helmet shell disperses at least thirty percent of an impact force applied to the helmet shell.
[0026] A fourth aspect of the present invention provides a helmet for cushioning a head during a sudden impact, and the helmet comprises a helmet shell having a humanoid head shape, and lateral members disposed around a circumference of the helmet shell. The helmet further includes a plurality of energy absorbing protective pads arranged on an interior surface of the helmet shell. Each of the energy absorbing protective pads comprises a slow recovery viscoelastic material with surface impregnation of a waterproofing material. The energy absorbing protective liner can be formed from slow recovery viscoelastic polyurethane foam with silicone as the waterproofing material. Advantageously, each of the energy absorbing protective pads can be shaped into pads of variable thickness and size.
[0027] The above and other aspects and advantages of the invention will become apparent from the following detailed description and with reference to the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate embodiments of the invention and, together with the description, serve to explain the aspects, advantages and principles of the invention. In the drawings,
[0029] FIG. 1 depicts a side view of a helmet according to a preferred embodiment of the present invention;
[0030] FIG. 2 depicts a side view of a helmet according to a preferred embodiment of the present invention;
[0031] FIG. 3 depicts a rear cross sectional view of an energy absorbing protective liner along line III-III shown in FIG. 1 ;
[0032] FIG. 4 depicts a rear view of a helmet according to a preferred embodiment of the present invention;
[0033] FIG. 5 depicts a rear view of a helmet according to a preferred embodiment of the present invention;
[0034] FIG. 6 depicts a side cross sectional view of an energy absorbing protective liner along line VI-VI shown in FIG. 4 ;
[0035] FIG. 7 depicts a rear cross sectional view of individual energy absorbing protective liner pads along line III-III shown in FIG. 1 ; and
[0036] FIG. 8 depicts a rear view of a helmet according to a preferred embodiment of the present invention;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] A detailed description of the preferred embodiments of the present invention will now be given referring to the accompanying drawings.
[0038] Referring to FIGS. 1 and 2 , a side view of a preferred embodiment of the energy-absorbing helmet is illustrated. The helmet 1 comprises a helmet shell 2 and an energy absorbing liner insert 4 having an exterior surface 5 that conforms to the interior surface 3 of the helmet shell 2 . The helmet shell 2 itself is comprised of thermoset plastic with reinforcing structures disposed thereon. The reinforcing structures will be described in more detail below.
[0039] Referring to FIG. 3 , a sectional view of the energy absorbing liner insert 4 without the helmet shell 2 along lines III-III is illustrated. The energy absorbing liner insert 4 is comprised of a foam layer 6 and a silicone layer 7 . The silicone layer 7 is bonded to the foam layer 6 , and the interior surface 8 formed by the silicone layer 7 is in contact with the athlete's head.
[0040] Referring to FIGS. 4 and 5 , a rear view of a preferred embodiment of the energy-absorbing helmet is illustrated. Again, the energy absorbing liner insert 4 is in direct contact with the interior surface 3 of the helmet shell 2 .
[0041] Referring to FIG. 6 , a side sectional view of the energy absorbing liner is illustrated, and the layering of the silicone layer 7 on the interior of the energy absorbing liner is shown. In a preferred embodiment, the silicone layer 7 is bonded to the interior surface of the foam layer 6 . Preferably, the foam layer 6 is viscoelastic polyurethane foam, and more preferably, the viscoelastic polyurethane foam is CONFOR foam. The silicone layer 7 penetrates into the open cell lattice network of the viscoelastic polyurethane foam layer 6 . The silicone layer 7 is cured at room temperature, since heating the viscoelastic polyurethane foam layer 6 will degenerate the structure of the viscoelastic polyurethane foam layer 6 . A primer coat (not shown) can be applied to the interior surface of the foam layer 6 to enhance the adherence of the silicone layer 7 . The silicone layer 7 can be applied as a 1-part compound or as a 2-part compound (or more than 2 parts if that becomes available). Pigment can be added to the silicone layer 7 for cosmetic reasons. The silicone layer 7 can be applied to only one surface or more than one surface of the foam layer 6 .
[0042] Applying the silicone layer 7 to a surface of the foam layer 6 prevents airflow through that surface. Application of silicone layer 7 to more than one surface will affect airflow through the foam layer 6 and its compression characteristics. Typically, open cell polyurethane foams have a Young's modulus in the order of 20 kilopascals due to the flow of air. Closed cell foam traps air and has a Young's modulus of approximately 100 kilopascals. This is discussed further in N. J. Mills, Micromechanics of Polymeric Foams, which is herein incorporated by reference.
[0043] The application of the silicone layer 7 over parts of the foam layer 6 can be tailored to specifically modify the stress/strain characteristics of the foam layer 6 and enhance its energy absorption characteristics. A full silicone layer 7 is applied over the surface of the foam layer 6 that will be in contact with the athlete's head.
[0044] The silicone layer 7 has multiple functions: (i) it can be tailored to affect airflow through the foam layer 6 and hence affect the energy absorbing characteristics of the foam layer 6 , and (ii) it prevents water absorption by the foam layer 6 . The foam layer 6 has a microscopic structure similar to that of the sponge and easily absorbs water. Uncoated open cell polyurethane foam can absorbed many times their weight in water. Water absorbed by open cell polyurethane foam adds to the weight of the open cell polyurethane foam. The water typically absorbed by the open cell polyurethane foam is that produced by the athlete during sweating. Any added weight in open cell polyurethane foam padding increases in the inertia of the head during athletic activities and decrease the effectiveness of the head protection. Therefore, to maximize the protectiveness of the energy absorbing liner insert 4 , it is important to eliminate the absorption of water.
[0045] The silicone layer 7 maintains the sanitation of the energy absorbing liner insert 4 . Sweating produces water, which is absorbed by uncoated open cell polyurethane foam. Athletic activities in warmer environments typically produce a great deal of sweat, unlike sports such as skiing and snowboarding where the athlete might not produce as much sweat in the helmet. The water from sweating and the contact from the athlete's skin can promote the proliferation of bacteria. Bacteria produce odors and can promote skin infections (e.g., folliculitis). Helmets are typically stored in dark or confined areas (e.g., athletic bags) that can further promote bacterial production. The silicone layer 7 coated on the foam layer 6 minimizes bacterial growth and enhances a sanitized helmet.
[0046] Viscoelastic open cell polyurethane foam has a tendency to degenerate with friction. This is commonly seen when using this type of foam for padding in a sports helmet. The friction causes a fine granular layer of foam to wear off from the foam padding, usually ending up in the athlete's hair or on the athlete's skin. Bonding the silicone layer 7 to the surface of the foam layer 6 that will be in contact with the athlete's skin prevents this degeneration.
[0047] In a preferred embodiment, the foam layer 6 is viscoelastic polyurethane foam of variable thickness and size for a helmet to be custom fit by a retailer. The viscoelastic polyurethane foam layer 6 has a unique characteristic in that warming easily deforms it, and thus it conforms to shape of the athlete's head when applied. The application of the silicone layer 7 does not interfere with this characteristic.
[0048] There is typically a limitation in the number of differently sized helmet shells available to the athlete. To maximize the protection afforded to the athlete, the helmet shell should have a custom fit to the athlete's head. The helmet should fit snugly and the padding should have intimate contact with the surface of the head throughout all areas of the helmet shell.
[0049] In a preferred embodiment, the thickness and size of the viscoelastic polyurethane foam layer 6 will vary in order to custom size a helmet 1 to each athlete. Within the helmet shell 2 , as much viscoelastic polyurethane foam layer 6 as possible be present within the helmet shell 2 in order to maximize the energy absorption in an impact. Thus, an athlete could use the same helmet shell 2 with several differently sized energy absorbing liner inserts 4 . The size and thickness of each energy absorbing liner inserts 4 would be based on the interior size of the helmet shell 2 and the size of the athlete's head. In the case of a growing young athlete, as the size and shape of the athlete's head changed, a new energy absorbing liner insert 4 could be fitted to the athlete's head, thereby insuring a snug fit for maximum protection.
[0050] Alternatively, instead of a unitary energy absorbing liner insert 4 , individual pads spaced within the helmet shell 2 can comprise the energy absorbing liner insert 4 . Preferably, the individual pads would be viscoelastic polyurethane foam. The individual pads are arrayed within the helmet shell 2 with minimal distance between them in order to maximize energy absorption.
[0051] Referring to FIG. 7 , an embodiment of a helmet shell 2 with multiple helmet pads 4 a - 4 g is illustrated. For the sake of clarity, each of the pads is shown without the silicone layer 7 . Each of the helmet pads 4 a - 4 g has a different thickness in order to illustrate how helmet pads of different thickness can be used to achieve a snug fit. For example, the helmet pad 4 a is not as thick as the helmet pad 4 g . Typically, each of these helmet pads would be the same thickness. However, if the helmet shell 2 is loose in that particular region, the thickness of one or more of the helmet pads can be increased to tighten the fit of the helmet shell 2 . Similarly, helmet pads 4 c - 4 e (in various thicknesses) can be used to adjust the height of the helmet shell 2 with respect to the athlete's head.
[0052] Thermoset resin is the “glue” that is needed to hold glass fibers together in a composite helmet shell. Thermoset resins are a family of plastics that do not melt, but chemically degrade at high temperatures. Thermoset resins are created by mixing two base materials just like epoxy glues (epoxy glues are thermoset resins). One of the ingredients is a catalyst that, when combined with the other agents and heat during molding, will solidify the mixture locking itself and the glass fibers into a rigid state. In compression molding applications, very little catalyst is used so that the liquid resin remains stable at room temperature; the heat and pressure of the molding operation initiates the chemical reaction to solidify the resin.
[0053] Thermoset resins by themselves have relatively little strength. The strength of a thermoset composite material comes primarily from the fibers of glass or other materials that are bonded together by the resin. There are three types of reinforcing fiber in common use today. Plastic materials (Kevlar, PBI) have very high strength and toughness but very low stiffness, and perform most efficiently when they are allowed to flex under load. In addition, these materials tend to be more affected by heat than other reinforcing fiber materials. Carbon fibers provide both strength and very high rigidity but are electrically conductive and therefore unsuitable for applications requiring high levels of electrical insulation. The third material family, glass fiber, provides the best combination of high strength, high stiffness, electrical insulation and cost of any reinforcing material in common use.
[0054] The challenge in designing an effective composite material is getting the right mix of a good thermoset resin and high content of glass. The performance of the composite is a function of the structural strength and adhesive properties of the resin, the length of the glass fibers and the amount of glass reinforcement in the composite. By increasing the strength of the resin and/or the length of the glass fibers, it can be possible to reduce the content of glass without sacrificing performance. This may result in a product that is easier to mold and has a better surface appearance. The glass fiber is heavier than the resin so getting the right mix also creates the best potential for a lighter helmet shell.
[0055] As a general rule, thermoplastic materials become softer and tougher as they get warmer, and harder and more brittle as the temperature goes down. Until relatively recently, it was possible to obtain either great heat resistance or great impact resistance, but not both in the same material.
[0056] In recent years, new thermoplastic materials have been developed which successfully combine both heat resistance and impact resistance. Polycarbonate began this trend in the 1960s; more recent materials such as GE's ULTEM and Amoco's RADEL now provide comparably high levels of impact resistance with heat resistance far exceeding that of polycarbonate. While the cost of these resins is very high, it is justified in certain demanding applications by their exceptional performance. As technology moves forward, these materials will continue to improve and expand in applications.
[0057] The helmet shell 2 play several vital roles. The helmet shell 2 is typically two to six millimeters thick and is either injection-molded thermoplastic or a pressure molded thermoset resin reinforced with glass fiber, KEVLAR fiber or carbon fiber. The helmet shell 2 is responsible for thirty to forty percent of the impact energy attenuation. The impact energy absorbed by the helmet shell 2 depends upon:
1. The thickness and material used for the helmet shell 2 . Thermoplastic shells absorb energy by viscoelastic deformation. Thermoset resin reinforced shells have lower elastic limits and undergo fiber fracture or delamination with impact energy. 2. The shape of the impacting objects. For example, flat-objects impact lower strains than convex rigid objects. 3. The distribution of local forces from an impact. The helmet shell 2 distributes a localized impact force throughout the surface of the helmet shell 2 . This distributed impact force is greatest at the point of impact and the distributed impact force will lessen as the radius from the distributed impact force increases.
[0061] If the athletic headgear did not have a helmet shell 2 , the energy absorbing liner insert 4 would have to be significantly thicker to provide the same type of protection. In the present invention, the helmet shell 2 protects the upper face, temples and ears from impact, and the helmet shell 2 slides easily on impact surfaces. The sliding of the helmet shell 2 on the impact surfaces decreases the rotational forces of the impact. The helmet shell 2 also supports other safety components, e.g., straps, face masks, etc.
[0062] The helmet shell 2 is responsible for a significant proportion of the impact energy dissipated by impact on to rigid objects. The stiffness of the helmet shell 2 plays a role in the dissipation of energy from an impact. The greater the stiffness of the helmet shell 2 , the greater the dissipation of energy. Thermoplastic helmet shells are less stiff than thermoset resin impregnated fiber helmet shells, and thus, thermoplastic helmet shells also rebound more. Certain types of thin walled helmet shells serve only to prevent the energy absorbing liner from breaking apart during impact (e.g., bicycle helmets).
[0063] The helmet shell 2 of the present invention has the following design criteria to protect the athlete's head:
1. The helmet shell 2 has sufficient thickness to provide rigidity. 2. The helmet shell 2 is comprised of a material that provides rigidity. 3. The helmet shell 2 absorbs thirty to forty percent of the impact energy.
In a preferred embodiment, the helmet shell 2 is a unitary structure. Because of the helmet shell's rigidity and strength, the energy from an impact on the helmet shell should be dissipated over the surface of the helmet shell 2 to minimize focused energy being transferred to a focused point on the energy absorbing liner insert 4 . The energy not dissipated by the helmet shell's rigid surface is then transferred to the energy absorbing liner insert 4 .
[0067] Typically, the side surfaces protecting the areas in front of, behind and slightly above the ear are less round than the top, front, and back surfaces of a sports helmet. These side surfaces are usually less rigid and deform greater with impact.
[0068] In the present invention, the side surfaces of the helmet shell are manufactured with more rigidity to provide greater impact attenuation. This increase in rigidity is accomplished in several different ways. For helmet shell 2 constructed of injected thermoplastic, increasing the thickness of the side surfaces thicker provides reinforcement to the side surfaces. For a helmet shell 2 constructed of reinforced thermoset resin, the side surfaces comprise additional layers of the fiber reinforcement mixed with the thermoset resin. As discussed above, the fiber reinforcement might comprise cloth fiber, glass fiber, KEVLAR fiber, carbon fiber or an equivalent thereof. Preferably, in the present invention, if a thermoset resin is used to manufacture the helmet shell 2 , the completed helmet shell 2 will include at least three layers of fiber reinforcement to maximize impact dissipation.
[0069] Referring to FIG. 1 , the helmet shell 2 of the present invention utilizes structures incorporated into the helmet shell 2 itself to increase the rigidity and the impact attenuation. In a preferred embodiment of the helmet shell 2 , a strut 10 is disposed between the strap attachment member 11 and a rear portion of the ear cutout 13 . The strut 10 traverses the ear cutout 13 at an angle, and reinforces the strap attachment member 11 for attenuating frontal impacts. Preferably, the helmet shell 2 further comprises a lateral member 13 that acts as a belt wrapped around a circumference of the helmet shell 2 . The lateral member 13 is integral to the helmet shell 2 , provides additional structural rigidity, and assists in impact dispersion. In a preferred embodiment, the lateral member 13 would be included in a unitary helmet shell 2 . The lateral member 13 is comprised of at least an upper lateral member 14 and a lower lateral member 15 , and a lateral channel 16 separates the upper lateral member 13 from the lower lateral member 14 . Together, the upper and lower lateral members 14 , 15 serve to absorb a portion of an impact force from the point of contact on the helmet shell 2 , and to dissipate the remainder of the impact force to other areas of the helmet shell 2 . The energy absorbing liner insert 4 attenuates the remainder of the impact force. The upper and lower lateral members 14 , 15 also increase the surface area of the helmet shell 2 , which further serves to attenuate the force of an impact. In a preferred embodiment, the lateral member 13 , the upper later member 14 and the lower lateral member 15 are two to six millimeters thick, although they can be made thicker if desired. In a preferred embodiment, to further reinforce the rigidity of the helmet shell 2 and to assist in the dissipation of an impact force, the upper and lower lateral members 14 , 15 and the lateral channel 16 have angled portions 22 , 23 , 24 as shown in FIG. 1 . The angled portions 22 , 24 of upper and lower lateral members 14 , 15 and the angled portion 23 of lateral channel 16 are disposed above the strap attachment member 11 . The angled portions 22 , 24 of the upper and lower lateral members 14 , 15 and the angled portion 23 of lateral channel 16 function to provide additional rigidity in a portion of the helmet shell 2 that has considerable flexure in conventional helmet shells. The angled portions 22 , 24 of the upper and lower lateral members 14 , 15 and the angled portion 23 of lateral channel 16 assist the strut 10 in reinforcing the strap attachment member 11 for attenuating frontal impacts. The downward angle of the angled portion 24 of the lower lateral member 15 and the angled portion 23 of lateral channel 16 is between thirty and sixty degrees, although the angled portion 24 of the lower lateral member 15 and the angled portion 23 of lateral channel 16 can be disposed at other angles as well. Referring to FIG. 7 , the upper lateral member 14 and the lower lateral member 15 are thicker than other portions of the helmet shell 2 . As a non-limiting example, if the upper portion of the helmet shell 2 was 2 millimeters thick, the upper lateral member 14 and the lower lateral member 15 might be five to six millimeters thick.
[0070] Referring to FIG. 4 , the disposition of the upper and lower lateral members on the rear of the helmet shell 2 is illustrated. Both the upper members 14 , 14 ′ and the lower members 15 , 15 ′ continue to wrap around the circumference of the helmet shell 2 to a point at the back of the helmet shell 2 . In a preferred embodiment, the lateral member 13 , 13 ′ from each side of the helmet shell 2 is smoothly contoured into the helmet shell 2 so there are no projections that could possibly injure the helmet wearer or another player.
[0071] Referring to FIG. 8 , the disposition of the upper and lower lateral members 14 , 14 ′, 15 , 15 ′ on the front of the helmet shell 2 is illustrated. The lateral members 13 , 13 ′ from each side of the helmet shell 2 continue to wrap around the circumference of the helmet shell 2 and merge together in the front of the helmet shell 2 . In a preferred embodiment, the lateral member 13 , 13 ′ from each side of the helmet shell 2 is smoothly merge together so there are no projections that could possibly injure the helmet wearer or another player. The angled portions 24 , 24 ′ of the lower lateral members 15 , 15 ′ can be seen in FIG. 8 as well. Vent holes 21 are provided through the lateral member 13 , 13 ′ for cooling purposes.
[0072] The foregoing description of 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 can 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 and with various modifications as are suited to the particular use contemplated.
[0073] Thus, while only certain embodiments of the invention have been specifically described herein, it will be apparent that numerous modifications can be made thereto without departing from the spirit and scope of the invention. Further, acronyms are used merely to enhance the readability of the specification and claims. It should be noted that these acronyms are not intended to lessen the generality of the terms used and they should not be construed to restrict the scope of the claims to the embodiments described therein. | Slow recovery viscoelastic polyurethane foam with a surface impregnation of silicone, coupled with a rigid helmet shell, is used for athletic headgear. The helmet shell should have a rigid construct to provide dispersion of impact energy, absorbing at least thirty percent of the impact energy delivered to the helmet shell. The slow recovery viscoelastic polyurethane foam has unique characteristics making it suitable for use as an energy absorbing liner for athletic headgear. The energy absorbing liner can be made with varying thickness and size, so retail establishments can custom fit a helmet to a particular customer. | 0 |
TECHNICAL FIELD
[0001] This disclosure relates to measuring rotating speed, and, more particularly, to non-contact measuring rotating speed of rotors suspended without mechanical contact using homopolar permanent-magnet-biased active magnetic bearings.
BACKGROUND
[0002] Active Magnetic Bearings (AMBs) are often used to support rotating members in magnetic fields without a mechanical contact. In such systems, a need often arises in non-contact measurement of a rotating speed of the member.
SUMMARY
Description of Drawings
[0003] FIG. 1 illustrates design and operation of a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator with an Integrated Rotational Speed Sensor in accordance with the present disclosure.
[0004] FIG. 2 schematically illustrates a typical voltage waveform on the output of the Hall-effect sensor in FIG. 1 when the rotor spins.
[0005] FIG. 3 illustrates design and operation of a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator with an Integrated Differential Rotational Speed Sensor in accordance with the present disclosure.
[0006] FIG. 4 schematically illustrates a typical voltage waveform on the output of the differential arrangement of Hall-effect sensors shown in FIG. 3 when the rotor spins.
[0007] FIG. 5 illustrates design and operation of a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator with a non-magnetic rotor and an Integrated Rotational Speed Sensor in accordance with the present disclosure.
[0008] FIG. 6 illustrates design and operation of a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator with Axial Force Offset and an Integrated Rotational Speed Sensor in accordance with the present disclosure.
[0009] FIG. 7 is a cross-sectional schematic of an example of an electric machine on Active Magnetic Bearings utilizing a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator with integrated speed sensor in accordance with the present disclosure.
[0010] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0011] This disclosure relates to measuring rotating speed, and, more particularly, to non-contact measuring rotating speed of rotors suspended without mechanical contact using homopolar permanent-magnet-biased Active Magnetic Bearings (AMB).
[0012] A magnetic bearing, such as an Active Magnetic Bearing (AMB), uses an electromagnetic actuator to apply a controlled electromagnetic force to support the moving member in a non-contact, or nearly non-contact, manner. The non-contact or nearly non-contact support provided by the magnetic bearing can provide frictionless or nearly frictionless movement of the member such as spinning around an axis. In certain implementations electromagnetic actuators may use permanent magnets, and may be referred to as Permanent-Magnet-Biased Electromagnetic Actuators. Electromagnetic actuators may be referred to as “homopolar” if in the absence of radial loading, the magnetic polarity stays the same around the rotor at a given axial position. Examples of homopolar actuators are discussed in the U.S. Pat. No. 8,169,118 titled “High-Aspect Ratio Homopolar Magnetic Actuator” and U.S. Pat. No. 8,482,174 titled “Electromagnetic Actuator”.
[0013] If an Active Magnetic Bearing system is used to support a rotating member, there is often a need to measure the rotational speed of the member without a mechanical contact. The concepts presented herein are directed to an arrangement and a method of measuring the rotational speed utilizing a Hall effect sensor integrated into a magnetic bias flux return pole of a radial homopolar permanent-magnet-biased electromagnetic actuator. Since the sensor is integrated into the actuator it does not require an additional space inside the machine, making it more compact and improving rotordynamic performance.
[0014] FIG. 1 illustrates design and operation of a Rotational Speed Sensor integrated into a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator in accordance with the present disclosure. FIG. 1 shows one radial and two axial cross-sectional schematics of a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator (actuator 100 ) with an integrated speed sensor in accordance with the present disclosure. Permanent magnet 2 is sandwiched between a radial actuator pole assembly 4 and a magnetic bias flux return pole 3 . More details of the radial actuator pole assembly 4 are shown in the cross-sectional view A-A on FIG. 1 . The permanent magnet 2 generates a magnetic bias flux 5 , which is guided by the magnetic bias flux return pole 3 toward the air gap 7 which separates the magnetic bias flux return pole 3 from a soft magnetic shaft 10 . The magnetic bias flux 5 then is directed within the soft magnetic shaft 10 towards a radial actuator target 11 , exits the radial actuator target 11 radially through radial air gaps 12 a - 12 d , travels radially within radial magnetic poles 18 a - 18 d towards the permanent magnet 2 where it completes the loop. In general, the positioning and composition of structural elements of the magnetic actuator 100 direct the magnetic flux 5 (generated by the permanent magnet 2 ) to propagate in accordance with the present disclosure.
[0015] The magnetic bias flux return pole 3 , the shaft 10 , the radial actuator target 11 and the radial pole assembly 4 may include or be composed of soft-magnetic materials (e.g., carbon steels and/or other soft magnetic material) that more effectively conduct magnetic fluxes than other materials.
[0016] The axial thickness of the magnetic bias flux return pole 3 may be chosen so that the pole material is magnetically saturated by the bias flux 5 . Since the magnetic saturation levels of ferrous alloys are known to be nearly independent of the temperature within a typical operating temperature range, this feature results in a bias flux 5 being nearly constant over a typical operating temperature range.
[0017] The mechanism of the radial force generation in a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator is explained in Section A-A of FIG. 1 . To produce radial forces in multiple (or all) directions within a radial plane, the radial pole assembly 4 is equipped with at least three radial control poles and control windings around these poles. For example, Section A-A of FIG. 1 shows four radial control windings 17 a - 17 d located in slots between the poles 18 a - 18 d . The bias flux 5 generated by the magnets 2 flows radially through the radial air gaps 12 a - 12 d and within the radial poles 18 a - 18 d . When the radial actuator target 11 is in the central position and there are no currents in windings 17 a - 17 d , the bias flux density under each pole 18 a - 18 d associated with windings 17 a - 17 d is the same or similar because of the system symmetry. Therefore, the net radial force may approach zero or be close to zero. By energizing the radial control coils 17 a - 17 d , the flux distribution can be altered so that a radial force would develop. For example, FIG. 1 shows coils 17 a and 17 c being energized with control currents 19 a and 19 c , respectively. These currents produce radial control flux 20 . In the air gap 12 a under the pole 18 a associated with the control coil 17 a , control flux 20 adds to the bias fluxes 5 , while in the air gap 12 c under the pole 18 c associated with the control coil 17 c , it subtracts. Since the flux density will be higher at the top of the radial actuator target 11 than at the bottom, there will be a radial force F Y 21 acting on the target, directed along the Y-axis 22 upwards in FIG. 1 (positive Y-direction). Similarly, by energizing windings 17 b and 17 d , a force can be produced in the direction of the X-axis 23 .
[0018] The radial actuator target may include a lateral surface adjacent and spaced apart from the radial pole. In certain instances, the target may be concentric to the actuator (or rotational) axis 15 , and may have a cylindrical (precisely or substantially cylindrical) shape.
[0019] In certain instances, the radial actuator pole assembly 4 and the radial actuator target 11 may be assembled of magnetically permeable and electrically conductive laminations (e.g., steel and/or other magnetically permeable and electrically conductive laminations) stacked axially and electrically isolated from each other. The isolation reduces eddy currents in these components induced when the rotor spins and/or the radial control windings 17 a - 17 d are energized with time-varying currents to produce time-varying radial forces.
[0020] To measure a rotational speed of the shaft 10 , the electromagnetic actuator 100 is equipped with a Hall-Effect sensor 30 embedded into the cylindrical surface of a magnetic bias flux return pole 3 adjacent to the shaft 10 or mounted in the air gap 7 separating the magnetic bias flux return pole 3 from the shaft 10 . The Hall-Effect sensor 30 is configured to measure a radial component of the magnetic bias field 5 in the radial gap 7 . Further, the shaft 10 has a feature, such as notch 31 , interrupting the continuity of its cylindrical surface and axially collocated with the Hall-effect sensor 30 . The notch produces a circumferentially local discontinuity in the magnetic field around the cylindrical surface of the shaft 10 in the air gap. The remainder of the magnetic field around the circumferential surface, axially collocated with the feature, is uniform (precisely or substantially) so that the discontinuity, magnetically speaking, is readily sensed by the Hall-effect sensor 30 . Thus, the magnetic field 5 sensed by the Hall-effect sensor 30 will be smaller when the sensor 30 faces the notch 31 rather than a continuous cylindrical surface. FIG. 2 schematically illustrates a voltage pulse generated by a Hall-effect sensor when a notch on the rotor passes by. The sensor output voltage is equal to V 0 when the sensor faces a continuous surface of the rotor 10 and drops to a lower value V notch when the notch passes by the sensor. Such pulses can be counted with an external counter and the number of pulses per unit time can be used to calculate the rotational speed of the rotor.
[0021] Because the level of the magnetic bias flux 5 is maintained nearly constant due to the magnetic saturation of the magnetic bias flux return pole 3 , the magnetic field measured by the Hall-effect sensor 30 at each specific orientation of the notch 31 will be nearly the same regardless the operating temperature, control currents in the windings 17 a - 17 d and other factors. Therefore, all those factors will not affect the sensor operation.
[0022] The Hall-effect sensor can be of a programmable type, which parameters such as gain and output zero offset can be programmed even after the sensor was already installed into a machine. This feature may be used to eliminate affects of various parameter variations such as air gap 7 , orientation and location of the Hall-effect sensor 30 , depth of the notch 31 , etc. The sensor parameters can be programmed after the sensor was installed so that the sensor outputs will be nearly the same from machine to machine if the sensor looks at the continuous surface of shaft 10 or the notch 31 .
[0023] FIG. 3 shows a different implementation of the proposed speed sensor using two Hall-Effect sensors 330 a and 330 b embedded into the cylindrical surface of a magnetic bias flux return pole 303 adjacent to the shaft 310 or mounted in the air gap 307 separating the magnetic bias flux return pole 303 from the shaft 310 . The associated electronics generate a difference between the outputs of two Hall effects sensors 330 a and 330 b which is used to measure the rotational speed of the rotor 310 similar to the pulse shown in FIG. 2 . Such a difference is shown in FIG. 4 . The advantage of using two Hall effect sensors 330 a and 330 b per FIG. 3 instead of one Hall effect sensor 30 per FIG. 1 is that the base signal level V 0 in FIG. 2 may be affected by temperature and other factors (such as axial movements of the rotor 310 ), which may make detection of the pulse difficult, whereas in FIG. 4 the base level will always be zero or near zero if two Hall-effect sensors 330 a and 330 b are the same and exposed to the same temperature and other factors.
[0024] FIG. 5 shows a sensor implementation in a case when the shaft 510 is made of non-magnetic material. In this case a magnetically-permeable actuator target extension 508 can be added to the shaft 510 to conduct the bias magnetic flux 505 from the magnetic bias flux return pole 503 to the actuator target 511 . A feature 531 triggering the speed sensor can be added to the actuator target extension 508 instead of magnetically permeable shafts 10 and 310 shown in FIGS. 1 and 3 respectively.
[0025] FIG. 6 shows another implementation of the proposed speed sensor in which the magnetic bias flux return pole 603 faces an axial facing surface of an actuator target extension 608 instead of the cylindrical surface as in FIGS. 5 . Such a configuration produces an uncontrollable axial force F z 615 always pulling the rotor 610 towards the axial pole 603 , which may be beneficial in some magnetic bearing applications, for example where there is a dominant external axial force pushing the rotor 610 away from the axial pole 603 , which may be offset by the force F z 615 .
[0026] In more details, permanent magnet 602 is sandwiched between a radial actuator pole assembly 604 and a magnetic bias flux return pole 603 . The permanent magnet 602 generates a magnetic bias flux 605 , which is guided by the magnetic bias flux return pole 603 toward the axial air gap 609 which separates the magnetic bias flux return pole 603 from an axial face of an actuator target extension 608 . The magnetic bias flux 605 crosses the air gap 609 , enters an actuator target extension 608 travels to the radial actuator target 611 , then it exits the radial actuator target 611 radially through radial air gaps 612 a - 612 d , travels radially within the radial actuator pole assembly 604 towards the permanent magnet 602 where it completes the loop. In general, the positioning and composition of structural elements of the magnetic actuator 600 direct the magnetic flux 605 (generated by the permanent magnet 602 ) to propagate in accordance with the present disclosure.
[0027] The magnetic bias flux return pole 603 , the shaft 610 , the radial actuator target 611 , an actuator target extension 608 and the radial pole assembly 604 may include or be composed of soft-magnetic materials (e.g., carbon steels and/or other soft magnetic material).
[0028] The axial thickness of the magnetic bias flux return pole 603 may be chosen so that the pole material is magnetically saturated by the bias flux 605 . Since the magnetic saturation levels of ferrous alloys are known to be nearly independent of the temperature within a typical operating temperature range, this feature results in a bias flux 605 being nearly constant over a typical operating temperature range.
[0029] The mechanism of the radial force generation in Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator 600 shown in FIG. 6 is the same as in actuators shown in FIGS. 1 and 3 . In addition, the actuator 600 also produces an uncontrollable and nearly constant force 615 due to presence of the bias magnetic flux 605 in the axial air gap 609 .
[0030] To measure a rotational speed of the shaft 610 , the electromagnetic actuator 600 is equipped with a Hall-Effect sensor 630 embedded into the axial surface of the magnetic bias flux return pole 603 adjacent to the axial face of the actuator target extension 608 . Alternatively, the Hall-Effect sensor 630 may be mounted in the axial air gap 609 separating the magnetic bias flux return pole 603 from the actuator target extension 608 . Further, the axial face of the actuator target extension 608 adjacent to the Hall-effect sensor 630 has a feature, such as notch 631 , interrupting the continuity of the face and radially collocated with the Hall-effect sensor 630 .
[0031] Because the level of the magnetic bias flux 605 is maintained nearly constant due to the magnetic saturation of the magnetic bias flux return pole 603 , the magnetic field measured by the Hall-effect sensor 630 at each specific orientation of the notch 631 will be nearly the same regardless the operating temperature, control currents in the windings 617 a - 617 d and other factors. Therefore, all those factors will not affect the sensor operation.
[0032] Similar to the speed sensor shown in FIG. 1 , the speed sensor shown in FIG. 5 can also benefit from using programmable Hall-effect sensors and a differential sensor arrangement similar to the one shown in FIG. 3 .
[0033] In some aspects, the proposed integrated rotational speed sensor may be used as a part of an Active Magnetic Bearing (AMB) system supporting a rotor of a rotational machine without a mechanical contact. In particular, when an AMB system is used in rotating machinery, the rotational speed sensor may deliver information about the rotational speed of the machine necessary for AMB operation and monitoring purposes. Since the sensor is integrated into a radial AMB design it does not require any additional space producing a more compact design with better rotordynamic characteristics. FIG. 6 shows an example of using an AMB system with an integrated speed sensor in an electric rotational machine 700 . The rotational electric machine 700 can be, for example, an electric motor 704 driving an impeller 706 (e.g., liquid and/or gas impeller) mounted directly on the motor shaft 708 . The electric motor 704 shown in FIG. 6 has a rotor 710 and a stator 712 . Alternatively, the impeller 706 can be driven by a flow of gas or liquid and spin the rotor 710 attached to it through the shaft 708 . In this case the motor 704 can be used as a generator which would convert the mechanical energy of the rotor 710 into electricity.
[0034] In embodiments, the rotor 710 of the electric machine 700 can be supported radially and axially without mechanical contact by front and rear radial AMBs 714 and 716 . The front AMB 714 provides an axial suspension of the rotor 710 and a radial suspension of the front end of the rotor, whereas the rear AMB 716 provides only radial suspension of the rear end of the rotor 710 . The rear AMB 716 is equipped with a rotational speed sensor per the concepts herein which includes a Hall-effect sensor 730 embedded into the cylindrical surface of a magnetic bias flux return pole 703 adjacent to the shaft 710 or mounted in the air gap 707 separating the magnetic bias flux return pole 703 from the shaft 710 . Further, the shaft 710 has a feature, such as notch 731 , interrupting the continuity of its cylindrical surface and axially collocated with the Hall-effect sensor 730 .
[0035] When the AMBs 714 and 716 are not working, the rotor rests on the mechanical backup bearings 720 and 722 . The front backup bearing 720 may provide the axial support of the rotor 710 and a radial support of the rotor front end, whereas the rear backup bearing 722 may provide radial support of the rear end of the rotor 710 . There are radial clearances between the inner diameters of the mechanical backup bearings 720 , 722 and the outer diameters of the rotor portions interfacing with those bearing to allow the rotor 710 to be positioned radially without touching the backup bearings 720 , 722 when the AMBs 714 and 716 are activated. Similarly, there are axial clearances between the backup bearings 720 , 722 and the portions of the rotor 710 interfacing with those bearings to allow the rotor 710 to be positioned axially without touching the backup bearings 720 and 722 when the AMBs 714 and 716 are activated.
[0036] In certain instances, the front AMB 714 may be a combination radial and axial electromagnetic actuator 701 per U.S. Pat. No. 8,482,174, combination radial/axial position sensors 724 and control electronics 750 . The electromagnetic actuator 701 may be capable of exerting axial forces on the axial actuator target 709 and radial forces on the radial actuator target 711 , both rigidly mounted on the rotor 710 . The axial force is the force in the direction of Z-axis 717 and the radial forces are forces in the direction of X-axis 718 (directed out of the page) and the direction of Y-axis 719 . The actuator may have three sets of coils corresponding to each of the axes and the forces may be produced when the corresponding coils are energized with control currents produced by control electronics 750 . The position of the front end of the rotor in space is constantly monitored by non-contact position sensors, such as combination radial/axial position sensor 724 .
[0037] Signals from the position sensors 724 may be input into the control electronics 750 , which may generate currents in the control coils of the combination electromagnetic actuator 701 when it finds that the rotor is deflected from the desired position such that these currents may produce forces pushing the rotor back to the desired position.
[0038] The rear AMB 716 is an electromagnetic actuator 728 , radial non-contact position sensors 725 , and control electronics 752 . It may function similarly to the front AMB 714 except that it might not be configured to control the axial position of the rotor 710 because this function is already performed by the front AMB 714 . Correspondingly, the electromagnetic actuator 728 may not be able to produce controllable axial force and there may be no axial position sensor.
[0039] The electromagnetic actuator 728 is equipped with a rotational speed sensor per the concepts herein which includes a Hall-effect sensor 730 embedded into the cylindrical surface of a magnetic bias flux return pole 703 adjacent to the shaft 710 or mounted in the air gap 707 separating the magnetic bias flux return pole 703 from the shaft 710 . Further, the shaft 710 has a feature, such as notch 731 , interrupting the continuity of its cylindrical surface and axially collocated with the Hall-effect sensor 730 .
[0040] When the rotor 710 spins, the Hall effect sensor 730 will see changes in the magnetic field at the sensor location whenever the notch 731 passes it producing a pulse of a positive or negative polarity. Such pulses can be counted with an external counter, which may be a part of a control unit 752 and the number of pulses per unit time can be used to calculate the rotational speed of the rotor.
[0041] The present disclosure describes embodiments of a Rotational Speed Sensor integrated into a Radial Homopolar Permanent-Magnet-Biased Electromagnetic Actuator. Other embodiments and advantages are recognizable by those of skill in the art by the forgoing description and the claims. | Radial poles are placed around a radial actuator target mounted on a body. The poles are separated from a cylindrical surface of the target by radial gaps and adapted to communicate a magnetic flux with it. The radial poles are equipped with electrical control windings and magnetically coupled to form magnetic control circuits. A flux return pole is adjacent to the body, separated from it by an air gap and adapted to communicate a magnetic flux with the radial actuator target. A permanent magnet generates a magnetic bias flux in the magnetic bias circuit formed by the radial actuator target, the radial poles and the magnetic flux return pole. A radial force is exerted on the actuator when the control windings are energized with a current. A Hall effect sensor measures bias magnetic field in the air gap between the magnetic flux return pole and the body. A feature on a body is adapted to produce a circumferentially local discontinuity in the magnetic field measured by the Hall effect sensor as the body rotates. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for managing environmental audit information. More particularly, the present invention relates to a system for managing environmental audit information based upon a set of established safety protocols, which is accessible over an internetworked system.
2. Description of the Prior Art
Environmental Health and Safety (EH&S) and Occupational Health and Safety (OH&S) audits are a critical aspect of an organization's review of its facilities. Such audits are performed with variety of methods which range from paper-based systems that are partially automated (either in a gathering of data and/or the management of the resulting information) to more sophisticated, automated methods. In large part, however, whatever method is used is apt to result in inconsistent documentation, redundant effort, lack of compatibility with existing databases and the potential for lost or inaccurate paperwork.
These audits are important for business and organizations to help insure that they are in compliance with federal, state, and local safety regulations, and to help minimize any potential liability that may arise from accidents occurring on the premises.
These audits are normally conducted by inspectors, who tour the facility and record any potential violations or issues of which they become aware. Typically, this information is recorded on paper sheets, with reference to particular regulations. These individual audit records are then complied into an audit log. As the number of facilities and areas under review increases, the audit log becomes voluminous.
Once the audit is complete, the information in the audit log must be reviewed and cataloged. This process can also take several weeks if not months to complete. Moreover, if mistakes, inaccuracies, or inconsistencies are found in the log, the area or facility may need to be reexamined for clarification. This can add even more time to the review process.
Once the review and cataloging of the log is complete, then one or more reports will be prepared documenting the results of the audit. This again can be a very time consuming process.
A number of systems have been proposed in the prior art for improving the general process of auditing information and compiling the results. For example, U.S. Pat. No. 6,154,753 to McFarland discloses a system for managing documents and conducting business quality modeling. The McFarland patent discloses a completely electronic system for entering information through a system of forms, and producing documentation to ensure compliance with the ISO 9000 quality standard.
Moreover, U.S. Pat. No. 5,864,784 to Brayton, discloses a hand held data collection and monitoring system for nuclear facilities, in which a pen based hand held computer unit has interactive software that allows the user to review maintenance procedures, collect data, compare data with historical trends and limits, and input new information at various collection sites. The system has a means to allow the automatic transfer of the collected data to a main computer base for further review reporting and distribution.
However, the systems of the prior art, such as those disclosed in the McFarland and Brayton patents, have the significant disadvantage in that they do not provide a system in which audit records can be indexed by the specific environmental or safety protocols to which they pertain. They also fail to provide for quality assurance review during the auditing process, which can be conducted remotely via an internetworked system, with the ability to restrict access as between the various inspectors and the quality assurance personnel.
SUMMARY OF THE INVENTION
The system of the present invention provides a complete solution for EH&S and OH&S audits, from the initial capture of data to the final resolution of the audit finding. The use of an automated system, as described in more detail below, improves audit performance, reduces costs of the program and reduces risks through use of a highly documented system that utilizes current technology while significantly reducing paperwork. The present invention facilitates a standard method of data collection, reporting, and tracking of audit findings, and allows this information to be analyzed and managed both locally and remotely. This provides significant advantages in cost reduction, improved quality assurance, overall reduction in audit life cycle time frame (from discovery of a finding to its final resolution) and reduced risk through better management tools and documentation.
The present invention is directed to a system for managing environmental audit information which includes receiving environmental audit information, accessing a predetermined set of environmental audit protocols, associating the audit information with at least one of the environmental audit protocols to form at least one environmental audit record, and storing the environmental audit record. The system of the present invention may also restrict access to the audit record, such that a quality assurance reviewer may review said audit record and may designate the status of that review, but may not modify the contents of the audit record.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of a preferred embodiment of the operation of the system of the present invention.
FIG. 2 is a diagram of the preferred embodiment of the system of the present invention operated remotely over a computer network.
FIG. 3 is a computer screen shot of a preferred embodiment of the home page of the client application of the system of the present invention.
FIGS. 4( a )–( h ) are computer screen shots of the preferred embodiment of the field tools of the system of the present invention accessed through the client application.
FIGS. 5( a )–( f ) are computer screen shots of the preferred embodiment of the reporting tools of the system of the present invention accessed through the client application.
FIG. 6 is a computer screen shot of a preferred embodiment of an audit summary report in accordance with the system of the present invention.
FIGS. 7( a )–( h ) are computer screen shots of the preferred embodiment of the administrative tools of the system of the present invention operated over a client application.
FIGS. 8( a )–( f ) are computer screen shots of a preferred embodiment of the client web views of the system of the present invention operated over a client application.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of preferred embodiments of the invention, which, however, should not be taken to limit the invention to a specific embodiment, but are for explanation and understanding only.
In its preferred embodiment, the present invention allows audit data to be captured using client software (allowing the user to work independent of a central database). The same functions can also be performed on the central database using a Web browser. This Web functionality may be used over a local intranet connection or through any Internet connection using the latest secure encryption technology to ensure complete data confidentiality and integrity. This functionality allows flexibility with regard to when and how data is captured and managed during the audit process. To prevent conflicts various user groups may be established, each having its own rules and rights concerning the functions, access and views that are granted.
The system of the present invention is programmed to gather and compile electronic data relating to EH&S and OH&S compliance audits. It facilitates the entry of audit information as the audit is being conducted (thereby reducing the need for paper), preferably using a computer for immediate data entry. Alternatively, information can be gathered through traditional methods (paper) and entered into the system at a later time. Once the data is entered into the system the data is immediately available for quality assurance reviews, publication of automated reports (electronic or paper) and information management. The functionality of the present invention allows information to be captured and managed using a client on a PC or through a Web browser. Transfer of data can be accomplished through, but not limited to, hard wire or wireless (wireless networks, cellular phone, satellite etc.) connections to local area networks (LAN), wide area networks (WAN), Intranets or Internet through either direct connection or dial-up. The central database can reside either locally within a LAN or WAN or hosted externally.
An important feature of the present invention is the collection of appropriate and relevant information about each facility being audited and identification of the audit issues. This allows the data to be sorted to aid in correcting the identified issues, in identifying trends, and in managing data and defining metrics.
The system of the present invention includes the several important features.
Data is entered regarding any audited discrepancy with reference to a specific regulatory citation or other defined audit criteria (protocols). This entry contains information specific to a given facility (i.e. name, contacts, address, facility classification, etc.), documentation of discrepancy and any pertinent information relating to that discrepancy (location, equipment type, serial numbers, etc.), digital image(s), classification of findings (i.e. relative to severity, cost impact, etc.), comments and potential corrective actions. All of this information is preferably maintained as part of a single audit record.
Quality assurance is an important part of the present invention. The ability to view findings (either locally or remotely) as soon as the data enters the central database allows the QA reviewer to view all components of the finding including photographs and provides a rapid assessment. All actions and comments relating to the quality assurance process are documented within the finding record indicating the comment, action taken (accept finding, reject finding, etc.), time and date of the action and the person performing the action. The record of the actions is preferably non-editable and maintained as a permanent record within the finding.
Once an audit finding is accepted as a valid finding (based on the QA process) the finding can be addressed and followed to resolution. At this point additional elements are available to be added to the finding record in order to allow the opportunity to manage the finding. These elements include, but are not limited to, assigning a finding to an individual for resolution, assignment of new priority levels, assigning due date, finding status, comments, responses and costs.
The functionality of the database of the present invention allows automated notification based on pre-established criteria with reference to specific elements within the database or actions to specified individuals or user groups. This notification can be communicated by various methods, including e-mail. The content of notification can be, by way of example, notification of past due assignments, changes in finding status, assignment of finding, etc. E-mail notifications have the capability to provide a direct Internet hyperlink directly to the finding in question.
The system of the present invention may integrate off-the-shelf components to facilitate workflow, management and development. Off-the-shelf components include, but are not limited to, computers (desktop, portable, wearable, handheld, etc.), digital cameras (still or video), voice recognition software and hardware and commercial software for application development and database management (i.e. Lotus Notes).
FIG. 1 illustrates the preferred operation of the system of the present invention. The process 100 starts with the auditor discovering a finding and submitting it to the central database 102 . At this point the QA reviewer can either accept the finding 104 or reject the finding 106 . If the finding is rejected the auditor can provide additional input and/or clarification. The auditor then resubmits the finding for additional QA review 108 . Once a finding has been accepted as part of the QA process the finding is then made available to the owner 110 . The owner can then assign the finding to the assignee, add comments, change finding status and query and sort the database to facilitate the resolution of findings while the finding status is in progress 112 . The assignee has rights to add only certain elements to the finding resolution data fields. Once resolution has been made to a finding only the owner can close the finding 114 . All of these functions can be performed through the client or Web browser.
A preferred embodiment of the system components of the present invention is shown in FIG. 2 . As shown in FIG. 2 , a laptop computer 1 (or any mobile input device, such as a PDA or the like) is used by the facility inspector to enter audit information into the system of the present invention. This information may be in the form of text, or may include digital images. Such images could be captured, for example, through the use of video unit 2 (which could also be any other means for obtaining digital images, such as a digital camera, or the like).
Once the inspector has entered the audit information into laptop computer 1 , this information is preferably transferred to a computer workstation 3 . This may be accomplished through any number of means well known to those of ordinary skill in the art, such as over an Ethernet network, via a wireless network, or via a transportable medium, such as floppy disk or writeable CD-ROM.
Information stored on computer workstation 3 is then preferably uploaded via Internet/intranet 4 to server 5 . Internet/intranet 4 may comprise not only the public Internet, but also a closed intranet system, VPN, local network, or the like. The operation of the internet and computer networks are well known to those of ordinary skill in the art and will not be elaborated upon here. Alternatively, the information inputted into laptop computer 1 may be uploaded directly to server 5 without the use of Internet/intranet 4 and computer workstation 3 . This may be accomplished in any number of ways well known to those of ordinary skill in the art, for example, through the use of a cell phone uplink, dial-up RAS, direct connection, or the like.
Server 5 then stores the audit information in data storage 6 . Data storage 6 is preferably a relational database, although not limited thereto. In the preferred embodiment of the invention discussed herein, data storage 6 is built upon the Lotus Notes platform, but is not limited thereto. Data storage 6 and server 5 are connected to Internet/intranet 4 in a conventional manner, such as via a local computer network, which may include one or more firewalls, routers, and related devices (not shown). The operation of these systems is well known to those of ordinary skill in the art.
The audit information stored in data storage 6 may be accessed through server 5 by the quality assurance inspector using computer 7 . Of course, the quality assurance inspector may also access the audit information in data storage 6 through computer 3 or by using the same laptop computer 1 as used by the facility inspector when compiling the information.
In the preferred embodiment of the invention, information is inputted into the system by the facility inspector and reviewed and commented upon by the quality assurance inspector through the use of a client/server software application that includes a series of drill down forms for inputting and extracting the information. In the preferred embodiment of the invention this client/server application is Lotus Notes, as noted above. The client portion of this software preferably operates on laptop computer 1 , computer workstation 3 , and/or computer 7 , whereas the server portion of the software is resident on server 5 , controlling access to data storage 6 .
The preferred embodiment of the software application used in connection with the system of the present invention will now be described in more detail in regard to FIGS. 2–7 .
FIG. 3 is a computer screen shot of the home page of the preferred embodiment of the software application of the system of the present invention. As shown in FIG. 3 , the software application of the system of the present invention preferably includes a set of field tools, reporting tools, administrative tools, and client web views. These will be described in more detail below. The home page of the system of the present invention may also preferably include active buttons for performing some of the more important tasks of the software application of the system of the present invention, including Create Audit Record, Add New Facility, and Add New Contact. The homepage may also preferably include active buttons for viewing records needing review and reviewing records listed by their status.
The field tools of the system of the present invention will now be described in more detail in regard to FIGS. 4( a )–( h ). As shown in FIG. 4( a ), the field tools may preferably include an active link to access all of the relevant audit records in data storage 6 that need to be reviewed by quality assurance personnel for approval or comment. The relevant audit records in data storage 6 can also be retrieved by status, by facility, by the author (e.g. the inspector inputting the audit information into data storage 6 ), by the particular facility, or by the designated contact at the facility. Of course, it would be appreciated to those of ordinary skill in the art that the manner of retrieving the relevant audit records from data storage 6 is not particularly limited to the aforementioned criteria.
As shown in FIG. 4( b ), when the quality assurance personnel selects the Need Review link on the client application running on computer 7 , server 5 accesses data storage 6 in a conventional manner and retrieves the audit records in the designated audit that need review by that quality assurance person. Access to various audits and audit records can be restricted through a multi-tier system of user access permissions. For example, a particular reviewer may only have access to certain ongoing audits, or may only be able to review information inputted into the system by a particular inspector under that reviewer's supervision.
As shown in FIG. 4( c ), by selecting that link, the user is able to retrieve audit records by their status. In the example shown in FIG. 4( c ), the status used are Not Accepted, Accepted, Resubmitted, and New. Not Accepted in this preferred embodiment of the system of the present invention refers to audit records which have previously been reviewed by the quality assurance personnel, but not deemed acceptable. In this prior review, the quality assurance person may have submitted comments back to the inspector, as described in more detail below.
Records which are deemed Accepted, of course, have been deemed acceptable by the reviewer. Resubmitted records are records for which the investigator has received comments back from the quality assurance personnel (or simply a rejection or non-acceptance of the record) and has updated and resubmitted that audit record to the system for further review. New records are records that have recently been inputted by the inspector, but which have not yet been reviewed by the quality assurance personnel.
The audit records are preferably presented in a summary list form providing relevant information, such as the aforementioned status, the control number, (or ID number) of the particular record in the system, the regulatory standard (protocol) which prompted the creation of this audit record, and statements or comments elaborating upon the particular record. The full content of the audit record may be accessed by double-clicking on the record summary or by some similar means known by those of ordinary skill in the art.
FIG. 4( d ) is an illustration of a complete audit record of the system of the present invention. While the format and information contained in the audit record is not particularly limited, in the preferred embodiment shown in FIG. 4( d ) the audit record includes the aforementioned record ID number or control number, the facility information, the date of the audit, and the audit team involved in preparing the audit.
More particularly, the audit record preferably contains a detailed set of fields correlated to the environmental regulations, rules, and provisions that are controlling for the audit. For example, such safety regulations may include the regulations and rules enforced by OSHA, as previously mentioned. These rules and regulations are also preferably stored in data storage 6 and integrated into the creation and updating of audit records, such as through the use of a series of drop down boxes and drill down menus included in the client application operating on computer 7 . Each audit record has a particular safety rule or regulation associated with it which distinguishes that audit record for the particular audit and for that particular safety criteria.
FIG. 4( e ) illustrates the retrieval of audit records by facility. As can be seen in FIG. 4( e ), the audit records are retrieved in the form of a hierarchical, expandable list, categorized, in this case, by facility. This hierarchical expandable structure is preferably applied to all of the methods of retrieving audit records so that the user can quickly and easily review the audit records to find the information they are seeking. FIG. 4( f ) illustrates the same retrieval process, except this time by author. FIGS. 3( g ) and 3 ( h ) illustrate retrievals of the facility list and facility contacts, respectively. Once again, these audit records are provided in the same convenient hierarchical, expandable list.
FIG. 5( a ) illustrates the preferred reporting tools of the system of the present invention. One of ordinary skill in the art will appreciate that the reporting tools are not limited thereto. These reporting tools allow audit records to be retrieved so that audit summary reports can be produced. The reporting tools preferably allow for audit records to be retrieved by the audit team conducting the audit, the date the records were modified, statistics by facility, and statistics by module, as illustrated in FIGS. 5( c )–( f ).
As shown in FIGS. 5( a )–( f ), an audit summary report can be generated by clicking on the appropriate link in the client application. When this link is activated, the application on server 5 retrieves the associated audit record report information from data storage 6 and generates a printable report which is returned to the client application on computer 7 .
The form of this report is not particularly limited, and can be produced by one of any number of systems well known to those of ordinary skill in the art, such as Microsoft Word, Corel WordPerfect, and the like. If the system of the present invention is being operated over the Internet, for example, the report may also preferably be provided in the form of an HTML based web page, or a PDF file.
An example of an audit summary report in the preferred embodiment of the present invention is shown in FIG. 6 . As shown in FIG. 6 , the audit summary report includes a formatted version of the selected audit record information included in the report.
FIGS. 7( a )–( f ) illustrate the preferred embodiment of the administrative tools of the system of the present invention. As can be seen in FIG. 7( a ), the administrative tools preferably include the ability to enter, update, and modify protocols, facilities, and contacts; and also the ability to delete these entries.
FIG. 7( b ) illustrates the manner in which protocols may be entered into the system. As shown in FIG. 7( b ), by clicking on the protocol entry link, a list of the relevant protocols (i.e. safety rules and regulations of the system of the present invention), are retrieved and displayed in a hierarchical, expandable manner. Protocol information may be entered and updated by highlighting and clicking on the particular protocol in question.
An example of the protocol information stored in the system of the present invention to be used in connection with the audit records is shown in FIG. 7( f ). As shown in FIG. 7( f ), the particular standard, section, and plurality of tiers are preferably included. These correspond to the particular regulatory section, subsection, and subparts to which the protocol relates. Statements or comments about the protocol may also be included for further explanation or clarification. Also, the particular regulatory citation number corresponding to the rule or regulation may also be included. This provides the significant advantage that rules and regulations can be indexed and searched quickly and accurately, and also allows for associated audit records to be similarly indexed and searched.
The severity of the rule may also be indicated, as well as the legal import. For example, statutes have a greater legal import than regulations, which are in turn more legally significant than rules, or guidelines. Similarly, a protocol may be a requirement, a simple preference, or a mere option. Information about the protocol document may also be included, such as who created the protocol record, who last edited the protocol record, and when these events took place.
Similarly, as shown in FIG. 7( c ), the information for different facilities being audited can also be retrieved and updated. Once the facilities have been retrieved by clicking on the facilities link, a particular facility record may be updated by clicking thereon.
An example of a facility record of the preferred embodiment of the system of the present invention is shown in FIG. 7( g ). As shown in FIG. 7( g ), the facility information may contain a facility ID number for accurate indexing of the information, the name of the facility, the type of facility, the location of the facility, and contact information. Of course, one of ordinary skill in the art will appreciate that the particular facility information to be included is not limited to the embodiment shown herein, and can include a variety of other facility related information.
The retrieval of contact information may occur in a similar manner as shown in FIG. 7( d ). An example of a contact record is shown in FIG. 7( h ), and can include information along the same lines as the facility information, such as an ID number, name, and contacting information.
Records which have been deleted, but not permanently deleted can be viewed by clicking on the deletions link in the administrative tools, as shown in FIG. 7( e ). The particular information for the audit record can be accessed by clicking on the record in question. This retrieves the audit record information described above. The deletion portion of the client application of the system of the present invention also preferably includes the ability to permanently delete records from the system, after which time they will no longer be accessible.
All of the aforementioned functionality of the system of the present invention may be accessed using a client application operating on computer 7 working in conjunction with a server application resident and operating on server 5 to access data storage 6 . However, the present invention also provides the ability to perform the same functionality using a web browser operating over the internet. The client web views are illustrated in FIGS. 8( a )–( f ). Using a web browser, the user operating at computer 7 may access the system of the present invention to review facility information and protocol information in the manner described above.
In addition, the user may review audit information by a designated priority, the date the audit record information is to be completed. The user may also view which audit records and audits are currently opened and which are closed and the level of progress of each.
The ability to enter, view, review, and updated and modify the audit, audit record, facility, and contact information stored in the system of the present invention may be restricted through the use of multiple layers of user access permissions. For example, the inspector who is creating an audit record may only have the ability to enter audit record information in a predetermined set of protocols at a predetermined number of facilities for which he or she is given access. In contrast, a quality assurance reviewer may only be allowed to review audit records from one or more particular inspectors, or from particular facilities or based upon particular protocols for which that quality assurance personnel has particular experience. The creation and updating of protocols and establishment of the facilities to be audited and the audit records to be imputed based upon the protocols may be restricted to administrative personnel only, or some overseeing supervisor to the quality assurance personnel and the inspector. Of course, these are only examples of the way in which user access may be restricted.
Although this invention has been described with reference to particular embodiments, it will be appreciated that many variations may be resorted to without departing from the spirit and scope of the invention. For example, although the preferred embodiment of the invention was described in connection with the software application Lotus Notes, it is certainly not limited thereto and may be implemented with any interactive data storage and retrieval application. Moreover, the system may be operated over a public network such as the Internet, or over a virtual private network or local network system. | The present invention is directed to a system for managing environmental audit information which includes receiving environmental audit information, accessing a predetermined set of environmental audit protocols, associating the audit information with at least one of the environmental audit protocols to form at least one environmental audit record, and storing the environmental audit record. The system of the present invention may also restrict access to the audit record, such that a quality assurance reviewer may review said audit record and may designate the status of that review, but may not modify the contents of the audit record. | 8 |
This application claims the benefit of U.S. Provisional Application No. 60/115,218, filed Jan. 8, 1999.
FIELD OF THE INVENTION
This invention generally relates to synthetic nonwoven materials fabricated by wet-laid processes. In particular, the invention relates to a paper-like web made with polyester fibers which is useful as a thermoformable liner material for framed structures, such as an office partition.
BACKGROUND OF THE INVENTION
A typical office partition construction involves laminating several different components together, with each component providing a specific functionality to the structure. Most of such structures use fiberglass mats which have been impregnated with phenolic or other thermosetting saturants to impart the desired rigidity to the structure. Such laminated structures are unnecessarily complicated and are not completely recyclable. There is a need for an improved office partition construction having fewer components.
An improved office partition comprises a rigid frame, e.g., a wooden panel, and a woven fabric which is attached to the wooden panel. There is a need for completely recyclable and environmentally friendly means for attaching the woven fabric to the wooden panel.
SUMMARY OF THE INVENTION
The present invention is a rigid thermoformable recyclable nonwoven liner material which is formed by a wet process on a papermaking machine. The wet-laying process is most suitable for this application as compared to other existing forming technologies due to the resulting uniformity in structure and tight construction. This invention also has the benefit of eliminating the manufacturing costs associated with dry web formation. The rigid thermoformable nonwoven liner material is intended to be laminated to a woven fabric and then thermomolded around a wooden panel to form an office partition. The paper-like construction is most beneficial in order to meet the tackability (i.e., tack-holding) requirement for the substrate.
The wet-laying process may consist entirely of conventional steps. The fiber furnish includes thermoplastic matrix fibers and thermoplastic binder fibers. In accordance with the preferred embodiment, the matrix fibers are made of polyester and the binder fibers are bicomponent fibers having co-polyester sheaths and polyester cores. The use of polyester is advantageous in that polyester is considered to be flame retardant in nature. The bicomponent fibers serve two purposes. First, the low melting point of the co-polyester enables bonding and therefore provides sufficient strength for on-line processing and handling during substrate manufacture. Second, the co-polyester sheath material is moldable at a lower temperature compared to the matrix polyester fibers.
In accordance with one preferred embodiment of the method of manufacturing a nonwoven liner material for use as a thermoformable liner in an office partition, the web of fibers coming off the papermaking machine is passed through a first binder application station, which applies a water-based solution, emulsion or foam having binder dispersed therein to one side of the web. In accordance with the preferred embodiment, the binder consists of polyvinyl chloride. The polyvinyl chloride binder features a curing mechanism which is activated by heat. The curing temperature of polyvinyl chloride is in the range of 225° to 280° F. Curing above 250° F. imparts the wet strength and the rigidity desired for the product. Alternatively, the binder can be polyvinylidene chloride or polyester.
The treated web exits the first binder application station and enters an infrared dryer comprising a plurality of infrared heaters which remove moisture from the web. Additional moisture is removed by passing the web through a first section of dryer cans. The dryer cans are heated to a temperature of about 300° F. Since the polyester sheath of the binder fiber has a melting point in the range of 225° to 240° F., the binder fibers are activated, i.e., the sheaths are melted, as the web passes over the dryer cans. Also the binder, which has a film forming temperature of 150° F. and a curing temperature ranging from 225° to 240° F., is activated.
After drying in the first section of dryer cans, the web passes through a second binder application station, which again applies a water-based solution, emulsion or foam to the web. The water-based solution, emulsion or foam has the same type of binder particles as those applied during the first binder application. The web is then passed through a second section of dryer cans to again remove moisture. The temperature of the dryer cans in the second section is about 300° F. Again the binder fiber sheath material is melted and the binder is activated as the web passes over the dryer cans. Upon cooling of the web, the binder fiber sheath material is fused to neighboring matrix fibers. The web is then wound on a winder roll. Optionally, the dried web is calendered using unheated calender rolls prior to winding.
The final product is a 100% recyclable, 100% thermoplastic nonwoven liner material. Being 100% thermoplastic in nature, the final product can be molded in a wide range of temperatures ranging from 225° to 300° F.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of apparatus for preparation of stock or furnish for manufacture of the composite material of the invention.
FIG. 2 is a diagrammatic view of apparatus for formation of a web by the wet-laying process and a first application of a binder.
FIG. 3 is a diagrammatic view of apparatus for drying the web and a second application of binder in accordance with the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with a first preferred embodiment of the invention, the fiber furnish comprises 20 wt. % of 2.0 denier×5 mm Type N-720H bicomponent (co-polyester sheath/polyester core) binder fiber supplied by Kuraray (sheath melting temp. 225° F.); 20 wt. % 1.5-denier×0.5″ Type 103 polyester staple fibers supplied by Hoechst/Celanese (melting temp. 480° F.); 40 wt. % 6.0-denier×1.0″ Type 103 polyester staple fibers supplied by Hoechst/Celanese (melting temp. 480° F.); and 20 wt. % 15.0-denier×1.5″ Type 103 polyester staple fibers supplied by Hoechst/Celanese (melting temp. 480° F.). All of the foregoing fiber types are sized by the respective manufacturer. It will be readily appreciated, however, that other polyester staple fibers could be used in place of the Hoechst/Celanese fibers specified above. Also the fiber deniers and lengths can be varied from those set forth above. Strength and porosity characteristics are imparted to the composite by the combination of polyester fibers employed in the invention. In particular, the strength of the composite can be improved by varying the polyester fiber content in accordance with the following functional relations: (a) as the polyester denier increases at constant length and amount, the porosity, bulk and stiffness of the composite increase and the amount of fiber entanglement decreases; and (b) as the polyester length increases at constant denier and amount, the tensile and tear strengths in the MD and CD directions and the Mullen burst strength increase and the stiffness decreases.
In accordance with other preferred embodiments, the amount of 2.0 denier×5 mm Type N-720H bicomponent binder fiber can be varied from about 0 to about 40 wt. %; the amount of 1.5 denier×0.5″ Type 103 polyester staple fibers can be varied from about 10 to about 30 wt. %; the amount of 6.0 denier×1.0″ Type 103 polyester staple fibers can be varied from about 20 to about 60 wt. %; and the amount of 15.0 denier×1.5″ Type 103 polyester staple fibers can be varied from 0 to about 60 wt. %.
Using a fiber furnish of the type described above, a high-strength nonwoven material is formed by a wet-laying process on a conventional papermaking machine. FIG. 1 illustrates an apparatus for preparation of stock or furnish for manufacture of the composite material. The wet-laid forming process begins with stock preparation to make an evenly dispersed mixture of the polymeric fibers. The polymeric fibers are opened (separated) and dispersed in a mixing tank 10 . The mixing tank 10 is equipped with an agitator which provides the shear energy required to effect good fiber separation and dispersion throughout the mix volume. Water, chemicals and fibers are added to the mixing tank 10 in controlled amounts to obtain a desired stock consistency. From an operational point of view, thicker stock consistencies are desirable to minimize preparation time and save on chemical usage. The consistency level should be chosen so that the forming process can be operated at its optimal speed for a particular grade of fabric.
With the completion of the stock preparation, the thick stock furnish is transferred to a holding or surge tank 12 , so that the next batch of stock can be prepared. The surge tank 12 is equipped with an agitator to keep the thick stock uniformly mixed. The surge tank 12 meters stock into a web forming machine via a pump 14 . The web forming machine 22 (shown in FIG. 2) may be of the type known as a Fourdrinier or a Rotoformer. The stock is fed to a head box 24 in the forming machine 22 where it is diluted with water to a lower consistency and brought to a forming zone of an endless wire (mesh) 26 moving in a machine direction. In the forming zone, water from the diluted stock is applied to the wire 26 is drawn through the wire, leaving behind the fiber web or sheet. The drained water is then recirculated through a primary water circuit. The temperature to which the polymeric fibers are exposed on the wet-laying machine 22 lies in the range of 325-365° F. During the wet-laying process, the co-polyester sheath materials of the N-720H bicomponent binder fibers (which sheath material has a melting point of 225° F.) melts and then fuses upon cooling to lend strength to the web during further processing.
After formation, the web W is transported to a first binder application station 30 by a transfer wire 28 . The first binder application station may comprise any conventional means for applying a water-based solution, emulsion or foam having binder dispersed therein, e.g., a saturator or a foam press.
In accordance with preferred embodiments of the invention, the binder is polyvinyl chloride. A preferred water-based emulsion of polyvinyl chloride is Vycar 460×95 (50% solids), which is commercially available from B.F. Goodrich Chemical Company. The Vycar 460×95 polyvinyl chloride binder has a curing temperature of 250-260° F. TN-810 or equivalent polyvinyl chloride binder can be used. The TN-810 polyvinyl chloride binder is commercially available from B.F. Goodrich Chemical Company and has a glass transition temperature greater than 130° F. The TN-810 is moldable in a temperature range of 225° to 300° F. Alternatively, the binder can be polyvinylidene chloride or polyester having a melting point lower than the melting point of the polyester matrix fibers.
Referring to FIG. 3, the foam-treated web exits the first binder application station 30 and enters an infrared dryer 32 comprising a plurality of infrared heaters which remove moisture from the web. Then the web is passed through a dryer section 34 comprising a multiplicity of dryer cans 54 , where additional moisture is removed. The dryer cans are heated to a temperature of about 300° F. Since the polyester sheath of the binder fiber has a melting point in the range of 225° to 240° F., the binder fibers are activated, i.e., the sheaths are melted, as the web passes over the dryer cans. Also the binder, which cures at a temperature of 225° to 280° F., are activated. After drying in the first section of dryer cans, the web passes through a second binder application station 38 , which applies a water-based solution, emulsion or foam of binder to the web. The same binder is applied by the first and second binder application stations.
The web W is then passed through a second section 40 of dryer cans 36 to again remove moisture following the second binder application. The temperature of the dryer cans in the second section is about 300° F. Again the co-polyester binder fiber sheath material is melted and the polyvinyl chloride binder is activated as the web passes over the dryer cans. Upon cooling of the web, the binder bonds to neighboring matrix fibers. The web is then wound up on a reel 48 for further processing. Optionally, the dried web is calendered, prior to winding, in a calendering section 42 using unheated calender rolls 44 and 46 .
The final product is a 100% recyclable, 100% thermoplastic nonwoven liner material. Being 100% thermoplastic in nature, the final product can be molded in a wide range of temperatures ranging from 225° to 300° F. The amount of polyvinyl chloride binder in the final product can be in the range of 25 to 40 wt. % of the total weight of the fibers in the nonwoven web. The first preferred embodiment (described above) has 40 wt. % binder add-on. In this case, with the base furnish weighing 4 oz./yd 2 , the final weight is around 5.6 oz./yd 2 . When samples of the first preferred embodiment were manufactured, the samples had an average stiffness in the machine direction of 2,308.5 mg.
The foregoing preferred embodiments have been described for the purpose of illustration only and are not intended to limit the scope of the claims hereinafter. Variations and modifications of the composition and method of manufacture may be devised which are nevertheless within the scope and spirit of the claims appended hereto. For example, the deniers of the various polyester matrix fibers can be varied depending on the molding conditions to be employed. In other words, the invention does not require the specific combination of deniers used in the preferred embodiments described above. Also a lower-melting-point polyester fiber, e.g., made of undrawn or amorphous polyester, can be used as the binder fiber, instead of polyester/copolyester bicomponent fiber, in a proportion from 0-40 wt. % of the total fiber furnish. In addition, bicomponent fibers having geometries other than the sheath/core geometry can be utilized. Depending on the degree of rigidity desired, a small amount of cross-linking agent (up to 10 wt. % of the binder) may be added to the polyester binder. If very high rigidity is desired, a B-stageable formaldehyde-free binder, such as HF-O5 supplied by Rohm & Haas Company, could be used. Other variations in web composition will be apparent to persons skilled in the art. | A rigid thermoformable recyclable nonwoven liner material is formed by a wet process on a papermaking machine. The rigid thermoformable nonwoven liner material is intended to be laminated to a woven fabric and then thermomolded around a wooden panel to form an office partition. The wet-laying process may consist entirely of conventional steps. The fiber furnish includes polyester matrix fibers and co-polyester/polyester bicomponent binder fibers. The web of fibers coming off the papermaking machine is passed through a foam press, which applies a water-based medium having polyvinyl chloride binder dispersed therein. The web is dried, treated again with a water-based medium having polyvinyl chloride binder dispersed therein and then dried again. The final product can be molded in a wide range of temperatures ranging from 225° to 300° F. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. provisional patent application Ser. No. 60/743,454, filed Mar. 10, 2006, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to above-the-floor cleaning attachments for vacuum cleaners. In one of its aspects, the invention relates to a cleaning tool that is adaptable for different types small constricted areas.
2. Description of the Related Art
In addition to having floor suction nozzles for on-the-floor cleaning, vacuum cleaners commonly have cleaning attachment tools that used for above-the floor cleaning operations, where the attachment tool is connected to a vacuum hose on a vacuum cleaner. When performing above-the-floor cleaning, surfaces to be cleaned in small, narrow and/or constricted areas are notoriously difficult to clean because many attachment tools are too large to fit into these areas. Crevice tools specifically developed for cleaning surfaces in small, narrow and/or constricted areas often fail as well since crevice tools are traditionally long, straight, and stiff, and cannot be fit into curved spaces very easily. More over, these crevice tools often require a user to bend over or stoop to achieve a proper orientation between the crevice tool and the surface to be cleaned, which can be painful to many users.
SUMMARY OF THE INVENTION
According to the invention, an accessory tool for a vacuum cleaner comprises a body having an attachment end for attachment to a suction hose and an elongated portion having a nozzle opening for ingestion of debris-containing air and a plurality of spaced furrows formed transverse to a longitudinal axis of the body, whereby the furrows are shaped and the elongated portion is made of a material that is selected to impart flexibility to the elongated portion transversely to the longitudinal axis.
In one embodiment, the furrows can be circumferentially formed around the elongated portion. The nozzle opening can comprise a rim that lies in a plane at an acute angle to the longitudinal axis of the body. The furrows can lie in planes that are parallel to the plane of the rim.
In another embodiment, the body can be integrally molded in one piece. The elongated portion can have an elongated cross-sectional configuration perpendicular to the longitudinal axis of the body. The elongated portion can be oval in cross-sectional configuration. The elongated portion can taper toward the nozzle opening.
In yet another embodiment, at least the elongated portion can be made of one of nitrile rubber, thermoplastic urethane, polypropylene, and polyurethane. The longitudinal axis of the elongated portion can be bent about a radius up to 45° without kinking or breaking. In a preferred embodiment, the longitudinal axis of the elongated portion can be bent about a radius up to 90° without kinking or breaking.
Further according to the invention, an accessory tool for a vacuum cleaner comprises a body having an attachment end for attachment to a suction hose and an elongated portion that has an elongated cross-sectional configuration perpendicular to a longitudinal axis and has a nozzle opening for ingestion of debris-containing air wherein the elongated portion is made of a material and is so designed to impart flexibility to the elongated portion transversely to the longitudinal axis so that the longitudinal axis of the elongated portion can be bent about a radius through an angle up to 45° without kinking or breaking.
In one embodiment, the longitudinal axis of the elongated portion can be bent about a radius through an angle up to 45° without kinking or breaking in a direction transverse to and laterally of elongated cross-sectional configuration.
In another embodiment, a wire is affixed to or within the elongated portion, wherein the wire has sufficiently stiffness and malleability so that the elongated portion can be formed to and can releasably remain in bent position.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a perspective view of a flexible crevice tool according to the present invention coupled with a vacuum cleaner.
FIG. 2 is a perspective view of the flexible crevice tool from FIG. 1 .
FIG. 3 is a cross-sectional view taken through line 3 - 3 of FIG. 2 .
FIG. 4 is a side view the flexible crevice tool from FIG. 1 .
FIG. 5 is a top view of the flexible crevice tool from FIG. 1 , illustrating the side-to-side flexing of the crevice tool.
FIG. 6 is a side view of the flexible crevice tool from FIG. 1 , illustrating the up-and-down flexing of the crevice tool.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and in particular to FIG. 1 , a cleaning attachment tool for a vacuum cleaner 100 is provided. The cleaning attachment tool comprises a flexible crevice tool 10 that can be coupled with a vacuum hose 200 connected to the vacuum cleaner 100 for above-the-floor vacuum cleaning. The crevice tool 10 can be used with any type of vacuum cleaner, including, but not limited to, upright vacuum cleaners (illustrated), canister vacuum cleaners, stick-type vacuum cleaners, hand-held vacuum cleaners, etc.
Referring to FIGS. 2-4 , the flexible crevice tool 10 comprises an elongated hollow body comprising an elongated portion 12 that is made of a flexible material that allows the crevice tool 10 to bend or deform as needed, without kinking, so that when a user is cleaning a surface in a hard-to-reach area, for example underneath or behind furniture. The crevice tool 10 can further be flexed to a wide range of curved configurations which requires the user to bend over or stoop less often to achieve a desired cleaning orientation between the crevice tool 10 and the surface to be cleaned. The material has sufficient resilience to otherwise retain a relatively straight shape. The flexible material preferably has a durometer in the range of 75-90 Shore A. Some non-limiting examples of flexible materials that can be used to construct the elongated portion 12 include nitrile rubber, thermoplastic urethane, polypropylene, and polyurethane.
As illustrated, the elongated portion 12 has a length L and includes a pair of spaced, generally straight side walls 14 , 16 joined by a curved upper wall 18 and a curved lower wall 20 . The elongated portion 12 has an elongated cross-sectional configuration, whereby the distance between the upper wall 18 and the lower wall 20 is greater than the distance between the side walls 14 , 16 . As illustrated, the cross-sectional configuration is roughly oval, although other cross-sectional configurations are possible. The walls 14 , 16 , 18 , 20 define an exterior surface 17 and an interior surface 19 of the elongated portion 12 . The interior surface 19 can be substantially smooth. The elongated portion 12 has a nozzle rim 21 at one end defining a nozzle opening 22 through which air containing dirt and debris is ingested. The nozzle rim 21 can be formed so that it lies in a plane P N that is at an acute angle to a longitudinal axis X of the crevice tool 10 , such that a user can hold the crevice tool 10 in an ergonomic manner while maintaining the nozzle opening 22 relatively flat against a surface being cleaned.
An attachment end 24 is positioned opposite the nozzle opening 22 and is sized to couple with a vacuum hose, such as the vacuum hose 200 , by a friction fit. As best seen in FIG. 4 , the attachment end 24 has a rim 25 defining an opening (not shown) that extends along a normal axis N of the crevice tool 10 . It is noted that the circumferential flange 26 on the attachment end 24 provides a stop for the end of the vacuum hose 200 . The attachment end 24 can be continuously molded with the elongated portion 12 . Alternately, the attachment end 24 can be made of a stiffer material than the elongated portion 12 to prevent flexing at the junction between the crevice tool and the vacuum hose, and can be attached to the elongated portion 12 using any suitable means. The material chosen for the elongated portion 12 preferably has suitable tear strength to withstand repeated flexing of the elongated portion 12 without separating from the attachment end 24 .
As illustrated, the attachment end 24 has a roughly circular cross-sectional configuration. Since the preferred cross-sectional configuration of the elongated portion 12 is oval, a transition portion 28 is formed between the elongated portion 12 and the attachment end 24 , where the cross-sectional configuration of the crevice tool 10 changes from oval to circular. The length L of the elongated portion 12 can be defined between the nozzle rim 21 and the transition portion 28 .
An air flow channel 30 is defined by the interior surface 19 through the crevice tool 10 between the nozzle opening 22 and the attachment end 24 . The elongated portion 12 is preferably slightly tapered, so that the air flow channel increases in area from the nozzle opening 22 to the attachment end 24 . The narrowing of the air flow channel 30 near the nozzle opening 22 increases suction at the nozzle opening 22 .
The elongated portion 12 can further be formed with a plurality of circumferential furrows 32 . As illustrated, the furrows 32 can be formed in the exterior surface 17 of the elongated portion 12 . Preferably, the furrows are formed on substantially the entire length of the elongated portion 12 . The furrows 32 are spaced from one another by a distance S, and preferably, the distance S is roughly equal between each furrow 32 . The furrows 32 have a width W, which is relatively narrow in comparison with the distance S. The furrows 32 are formed transverse to the longitudinal axis X of the crevice tool 10 , and can lie in an series of planes P F that are parallel to the plane P N of the nozzle rim 21 . It is further noted that that the planes P F and P N lie at an acute angle to the normal axis N. This configuration imparts the greatest amount of flexibility of the elongated portion 12 while holding the crevice tool 10 in an ergonomic manner.
The furrows 32 function to increase the flexing of the crevice tool 10 as illustrated by FIGS. 5 and 6 , whereby the elongated portion 12 of the crevice tool 10 can be flexed in multiple directions as indicated by the phantom line drawings of the crevice tool 10 . As shown in FIG. 5 , the elongated portion 12 of the crevice tool 10 can be flexed laterally (side-to-side) such that the longitudinal axis X of the crevice tool 10 at the nozzle opening 22 is orientated at a bend angle up to 90° to the longitudinal axis X at the attachment end 24 , without kinking or breaking of the elongated portion 12 . As shown in FIG. 6 , the elongated portion 12 of the crevice tool 10 can be flexed longitudinally (up and down) such that the longitudinal axis X of the crevice tool 10 at the nozzle opening 22 is orientated at a bend angle up to 90° to the longitudinal axis X at the attachment end 24 , without kinking or breaking of the elongated portion 12 . As illustrated, the bend angle of the crevice tool 10 is substantially equal whether flexing the elongated portion 12 laterally or longitudinally. The elongated portion 12 of the crevice tool 10 can further be flexed in a combination of lateral and longitudinal flexing. Moreover, since the furrows 32 are formed on substantially the entire length of the elongated portion 12 , the elongated portion 12 can flex along substantially its entire length.
The crevice tool 10 can optionally comprise a wire (not shown) affixed to or molded within the elongated portion 12 . The wire is sufficiently flexible or malleable so that the elongated portion 12 can be formed to and can remain in a desire arc without having to apply flexing pressure to the crevice tool 10 .
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that the description is by way of illustration of one embodiment of the invention and not of limitation. Reasonable variation and modification are possible within the forgoing description and drawings without departing from the scope of the invention which is defined in the appended claims. | An accessory tool for a vacuum cleaner comprises an elongated body having a plurality of furrows for imparting flexibility to the accessory tool. The elongated body is further be made of a material that is selected to impart flexibility to the accessory tool so that the longitudinal axis of the elongated portion can be bent about a radius through an angle up to 45° without kinking or breaking in a direction transverse to and laterally of elongated cross-sectional configuration. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a microwave oven, and more particularly, to an apparatus and a method for heating a container containing food or the like in a microwave oven by judging a quantity of food in the container on the basis of a change of an initial temperature of the food and compensating for variations between a detected temperature and a cooking temperature.
In a general method for heating a container in the microwave oven, the container is heated in a heating mode until the temperature detected by an infrared sensor is raised to the prescribed temperature.
FIG. 1 is a block diagram showing the structure of the conventional microwave oven.
In the conventional microwave oven, as shown in FIG. 1, the cooking chamber 1 has an opening 4 formed at the upper portion of its side wall. An infrared sensor 5 for sensing the temperature of the container 7 is set therein through the opening 4. Further, the microwave oven includes a heating unit 3 generating microwaves on the basis of the temperature detected by the infrared sensor 5 and a judging unit 6 controlling the operation of the object.
In the lower portion of the cooking chamber 1, a motor 8 is provided to drive a turntable 2 according to a control signal for the judging unit 6. The turntable 2 is rotatably mounted within the cooking chamber 1 on the upper portion of the shaft of the motor 8. On the turntable 2, the container 7 containing the food to be cooked is located.
The judging unit 6 controls operation of the heating unit 3 and the motor 8 after a heat starting key is actuated. The judging unit 6 includes the structure indicated in FIG. 2. This structure is described in detail as follows. The judging unit 6 comprises a key input unit 6a for setting a cooking temperature corresponding to the selected food or for inputting a starting signal; a set temperature storing unit 6b for storing the set cooking temperature; a current temperature storing unit 6c for temporarily storing the current temperature detected by the infrared sensor 5; a display unit 6d including a liquid crystal display to indicate the set and current temperature; and an output controlling unit 6e for comparing the set temperature with the current temperature to thereby control the output.
With the signal detected by the sensor 5, the current temperature is judged by the judging unit 6. When the detected current temperature is lower than the set temperature, the judging unit 6 operates the heating unit 3 until the current temperature reaches the set temperature for completion of cooking.
The cup 7 within the cooking chamber 1 is heated by the microwaves generated by the heating unit 3. When starting the heating operation, the turntable 2 is rotated to evenly apply the microwaves to the container 7.
Hereinafter, the operation of the conventional microwave oven is described in detail accompanying the drawings.
FIG. 3 is a flow chart illustrating a cooking operation of a conventional microwave oven.
The container 7 is first put on the turntable 2 in the cooking chamber 1, the key input unit 6a is operated to set the appropriate cooking temperature, and the cooking start key is actuated. The set cooking temperature is memorized in the set temperature storing unit 6b. When the cooking starting key is activated, the heating unit 3 is driven according to a controlling signal from the output controlling unit 6e. As a result, microwaves are generated by the heating unit 3 so that the container 7 with food therein is heated. Because of the heating operation of the heating unit 3, the temperature of the container 7 gradually increases.
On the other hand, the temperature of the container 7 is detected by the infrared sensor 5 through the opening 4.
The output controlling unit 6e reads the temperature stored in the current temperature storing unit 6c and the cooking temperature stored in the set temperature storing unit and compares them (step 110). When the detected current temperature is lower than the cooking temperature, the heating unit 3 is continuously driven by the output controlling unit 6e to heat the container 7. When the current temperature is raised to at least the set cooking temperature, the output controlling unit 6e stops operation of the heating unit 3 for completion of cooking (step 120).
The container 7 located in the cooking chamber 1 may include a cup containing a food such as water or milk. Since the container is heated by the microwaves generated by the heating unit 3, the practical temperature of the food 9 in the container 7 can be higher than the cooking temperature when the current temperature is detected by the infrared sensor 5. Particularly, when a small amount of food 9 is in the container, the difference between the actual temperature of the food 9 and the set cooking temperature is larger.
This difference is caused by heat conduction. That is, the heat of the food 9 is transmitted to the container 7 so that the food 9 is at a higher temperature than that of the container. Further, the temperature deviation between the various parts of the container 7 and the food causes a temperature difference between the container 7 and the food according to quantity of the food present.
For example, when the container is heated to a set cooking temperature of 50° C.,
if the amount of food in the container is 100 ml, its temperature is 73° C.;
if the amount of food in the container is 150 ml, its temperature is 69° C.;
if the amount of food in the container is 200 ml, its temperature is 63° C.;
if the amount of food in the container is 250 ml, its temperature is 51° C.;
if the amount of food in the container is 300 ml, its temperature is 51° C.; and
if the amount of food in the container is 350 ml, its temperature is 43° C.
In the conventional method of heating a container in the microwave oven using the infrared sensor 5, a small quantity of food is blocked from the sensing region of the infrared sensor 5 by the sides of the container since the infrared sensor 5 is mounted at the upper portion of the side wall (as shown in FIG. 4).
In the conventional microwave oven, therefore, the actual food temperature is in the container has the great difference temperature from the set cooking temperature. As a result, there is some inconvenience for the user.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus and a method for heating a cup or container in a microwave oven in which a difference between the temperature of the food within the container and the set cooking temperature can be minimized.
In order to achieve this object, the method according to the present invention comprises detecting a change in temperature for an initial uniform time period, judging the quantity of food on the basis of the detected change in the temperature, estimating the raised temperature on the basis of quantity of food, comparing the estimated temperature with the temperature detected by sensor to select the higher temperature of the two as a current temperature, and continuing cooking until the current temperature is raised to the set cooking temperature.
Further, an apparatus according to the present invention comprises means for storing a temperature gradient dependent upon the change in temperature detected by the sensor for the initial uniform time period; a first storing means for storing a temperature detected by the sensor; a second storing means for storing an estimated temperature, the estimated temperature being in inverse proportion to the temperature gradient stored the gradient storing means and in proportion to the current time; and means for comparing temperatures stored in the first and second storing means to heat the container at the higher temperature.
In the apparatus and the method of heating the cup according to the present invention, variations in the detected temperature of the food may be compensated, because the infrared sensor cannot accurately detect the temperature of small quantities of food subject matter in the cup.
For large variations of the initial temperature, (that is, for large quantities of the food), the change in temperature for the food is directly detected by the infrared sensor so that the estimated temperature is raised with a certain low temperature gradient.
For small variations of the initial temperature, (that is, for small quantities of food), the change in temperature for the food cannot be measured by the infrared sensor so that the estimated temperature is raised with a prescribed high temperature gradient.
Thus, the detected temperature is compensated according to the quantity of the food in the container. The temperature deviation for quantity of the food can be minimized by comparing the compensated current temperature with the set cooking temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing the conventional microwave oven;
FIG. 2 is a block diagram showing the judging unit of FIG. 1;
FIG. 3 is a flow chart showing a method of heating a cup of food in the conventional microwave oven;
FIG. 4 is a view showing how the temperature of a small quantity of food is sensed by the sensor to the present invention;
FIG. 5 is a block diagram showing the judging unit for temperature compensation control according to the present invention;
FIG. 6 is a flow chart showing the method of heating a container of food according to the present invention; and
FIG. 7 and FIG. 8 are graphs showing the characteristics of the temperature compensation according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention is described in detail accompanying the drawings.
The entire structure of the microwave oven is illustrated in FIG. 1 and the judging unit is illustrated in FIG. 5.
The microwave oven comprises a rotatable turntable 2 provided at the center of the cooking chamber 1, a heating unit 3 for generating microwaves to heat a container 7 containing food of the like, a temperature sensor 5 of thermopile type for detecting the temperature of the container 7 in the cooking chamber 1 in on-contact manner (through the opening 4 formed at the upper portion of the side wall in the cooking chamber 1), and the judging unit 6 for controlling operation of the circuit unit including the heating unit 3 according to the detected temperature.
The judging unit 6 comprises key input unit 6a by which the cooking temperature of the selected food is set to an appropriate temperature and by which the heating operation is started (with a "start" key). Set temperature storing unit 6B stores the set cooking temperature. First current temperature storing unit 6C stores the current temperature as detected by the sensor 5. Display unit 6D displays the set cooking temperature, the current temperature, and the time. Further, the judging unit 6 includes output controlling unit 6E for controlling the output by comparing the current temperature with the set cooking temperature, a timer 6F for measuring the cooking time, a first storing unit 6G for storing the gradient of the change in the initial temperature of container 7, and a second current temperature storing unit 6H for estimating and storing the current estimated temperature of the food 9 in the container 7.
In the above structure, when a user operates the key input unit 6 to heat the container 7, the heating unit 3 heats the container 7 for the initial set time period under the control of the output controlling unit 6E. When the container 7 is heated for this set time period, the change in temperature over time is detected. At this time, the detected gradient (or rate of change) of the temperature change is stored in the storing unit 6H. The output controlling unit 6E judges the quantity of the food in the container 7 by this gradient and estimates the raised temperature according to this quantity.
At this time, an initial time period (which is a part of the total heating time) is selected. If the change in the detected temperature is large during the initial time period, this means that the change of the temperature is directly detected by the infrared sensor 5, as shown in FIG. 1. In this case, the food or the like in the container 7 is more than an appropriate quantity. That is, the food temperature is rapidly raised at the initial state of the heating, so the temperature change sensed by the infrared sensor 5 becomes large.
If the change of the detected temperature is small during the initial time period, this means that the temperature change is not directly detected by the infrared sensor 5, as shown in FIG. 4. In this case, the heat is conductivity transmitted to the container 7 after the food in the container 7 is heated. Thus, the temperature of the container in the initial heating state is barely different from the temperature before heating. As a result, since the temperature of the container 7 is held at a low temperature during initial time period, the change in the temperature detected by the infrared sensor 5 during the initial time period is small. As described above, when the change in the temperature detected by the infrared sensor 5 during the initial time period is small, the infrared sensor 5 does not directly detect the temperature of the food so that a small quantity of food or the like is judged to be present.
By the above method, the output controlling unit 6E judges the amount of the food or the like in the container 7 and estimates the temperature of the food on the basis of its quantity. Further, the output controlling unit 6E compared the thus estimates temperature with the set cooking temperature to operate in the cooking mode until the estimates temperature is raised to the cooking temperature.
Hereinafter, the operation of the present invention is described in detail relative to FIG. 7.
FIGS. 7 and 8 are graphs showing the characteristics of the temperature compensation in the heating method.
First, the user puts a container 7 containing water or milk or food on the turntable 2 and actives the heat starting key of the key input unit 6A. When the heat starting key is activates the turntable driving motor 8.
On the other hand, the cooking temperature is set by the user through the key input unit 6A before activating the heat starting key, and this set cooking temperature is stored in the set temperature storing unit 6B. This means that the cooking temperature is set by the user according to the kind of the food to be cooked. For some food, however, the cooking temperature is previously stored in the set temperature storing unit 6B so that the output controlling unit 6E reads the previously stored cooking temperature to drive the motor 8 and the heating unit 3 accordingly. In other words, the output controlling unit 6E recognizes the current cooking temperature.
Similarly, the cooking time is also set by the user through the key input unit 6A before activating the heat starting key. Further, a previously set cooking time can be recognized by the output controlling unit 6E by selecting an automatic cooking mode.
As described above, the output controlling unit 6E recognizes the cooking temperature and the cooking time when the heating unit 3 starts to oscillate.
When the heating unit 3 is operating, the time counted by the timer 6F is continuously inputted to the output controlling unit 6E so that the output controlling unit 6E judges that, for example, 30 second after start of the heating has elapsed (step 201). In the step 203, the change of the temperature is detected for an initial constant time period (for example, the 30 second). Therefore, it is not necessary for the initial constant time period to be limited to 30 seconds. According to the kind of the food, the initial constant time periods can be long or short corresponding to a long or short total cooking time so as to detect the change of the temperature.
Thus, the output controlling unit 6E detects the temperature gradient process from the start of the heating operation to the expiration of the initial constant time period (about 30 seconds) by step 201. The current temperature detected by the infrared sensor 5 is temporarily stored in the current temperature storing unit 6C. This stored current temperature is repeatedly compared with the previously detected temperature to detect the temperature gradient according to the change of the temperature over the constant time period (step 203).
In the step 203, the temperature gradient is detected differently in the following two cases. The first case is when the change in cooking temperature during the 30 seconds after starting the heating process (i.e., the initial constant time period) is large, as shown in FIG. 7. The second case is that the change in the cooking temperature for the initial constant time period is comparatively small as shown in FIG. 8.
If the temperature gradient during the initial constant time period (about 30 seconds, which should be a multiple of the turntable rotating period to detect correctly the variation degree of the temperature) is steep as shown in FIG. 7, the infrared sensor 5 directly detects the temperature of the food 9 in the container 7 as shown in FIG. 1.
In this case, the container 7 contains a large quantity of food, so that the output controlling unit 6E estimates a temperature which is in proportion to the cooking time and in inverse proportion to the gradient detected in the step 203. After the initial constant time period, the output controlling unit 6E estimates the cooking temperature with the following equation (1).
estimating temperature=a/b(current time-30 seconds)+c (1)
where a is a certain constant.
On the basis of the highest temperature (c) detected over, for example, 30 seconds, the output controlling unit 6E obtains an estimated temperature, which is in inverse proportion to the gradient change of the initial temperature obtained in the step 203 (a/b), and in proportion to the cooking time (current time-30 seconds). At this time, since the estimated temperature is calculated by the lower gradient than the gradient obtained in the step 203, the rate of change of the estimated temperature is small. Thus, the rate of change of the estimated temperature is less steep than the temperature during the initial period shown in FIG. 8 (step 205).
As shown in FIG. 8, when the gradient of the temperature for initial constant time period (about 30 seconds, which should be determined in the multiple of the rotating period to detect correctly the change in temperature) is less steep than the gradient shown in FIG. 7, the infrared sensor 5 cannot directly detect the temperature of the food 9 in the container 7.
In this case, the container 7 contains the small quantity of food, so that the output controlling unit 6E estimates a temperature thereof which is in proportion to the cooking time and in inverse proportion to the detected temperature gradient. In this time, also, the current temperature is estimated with equation 1. The temperature to be estimated rises with a larger gradient than the initially calculated gradient (because of the inverse proportionality between the two). In this case, therefore, the gradient is steeper than the gradient shown in FIG. 7 (step 205).
When the current temperature is estimated in the step 205, the output controlling unit 6E compares the estimated temperature dependent upon the cooking time with the temperature detected by the sensor 5 (step 207).
If the detected temperature is higher than the estimated temperature, the output controlling unit 6E selects the detected temperature as the current temperature (step 213). In the detected temperature is lower than the estimated temperature, the output controlling unit 6E selects the estimated temperature as the current temperature (step 209).
That is, the output controlling unit 6E selects the higher temperature amongst the detected temperature and the estimates temperature as the current temperature. As shown above, since the higher temperature of the two is selected as the current temperature of the food 9 in the container 7, the temperature deviation that is dependent upon the quantity of the food 9 is decreased. Further, the selected current temperature and the set cooking temperature are compared each other (step 211).
Until the selected current temperature is raised to the cooking temperature, the heating unit 3 is driven. When the current temperature reaches the cooking temperature reaches the cooking temperature, the heating unit 3 is stopped by the output controlling unit 6E (step 215).
In the present invention, as described above, it is judged that the cup contains a large quantity of food when the change of the initial temperature is large. Thus, the current estimated temperature rises with a small gradient. In case of a small change of the initial temperature, however, it is judged that the container contains a small quantity of food so that the estimated temperature rises with a large gradient. By comparing the calculated temperature with the set cooking temperature, temperature deviations dependent upon the amount of food in the container can be minimized.
As shown above, the present invention estimates the detected temperature by judging the quantity of the food in the container and this estimated temperature is compared with the set cooking temperature for cooking. Therefore, the cooking temperature may be controlled precisely, so that the user is able to obtain well-cooked food. | The present invention relates to a microwave oven, and more particularly to an apparatus and a method for heating food or the like in a container using a microwave oven by judging a quantity of food in the container based on a change in initial temperature and compensating for variations between a detected and a cooking temperature. The method of heating the cup according to the present invention comprises the steps of detecting variation degree of the temperature for initial uniform time period, judging the quantity of the subject matter on the basis of the detected variation degree of the temperature, estimating the raised temperature on the basis of quantity of the subject matter, comparing the estimated temperature with the temperature detected by sensor to determine the higher temperature as a current temperature, and executing the cooking mode until the current temperature is raised to the set cooking temperature. | 7 |
RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 10/758,339 entitled, “VALVE SECURITY DEVICE,” filed Jan. 15, 2004 now U.S. Pat. No. 6,920,894.
BACKGROUND OF THE INVENTION
The present invention relates to valve security devices and, more particularly, to a device that is adaptable for use on a wide variety of fluid flow valves, both liquid and gas, to prevent access to the valve actuating key with varying degrees of security depending on the particular application.
Different levels of security are desirable in valve protection devices depending on the nature of the fluid flow line in which the valve is being used. For example, to provide a security device for a valve on a fire hydrant, it generally would be undesirable to employ a security device that could not be forcibly circumvented with conventional equipment such as a heavy-duty bolt cutter. If such a device was used and the only key that could unlock the device to provide access to the actuating key on the hydrant was lost or temporarily misplaced, firefighters could be prevented from accessing the water in a time of acute emergency. However, some form of locking or security device on fire hydrants is desirable in many areas, particularly in areas where the hydrants may be subject to malicious mischief and rural and farming areas where water may be in short supply and great demand. Such situations have led to increasing incidences of water theft. In such areas prone to water theft, some form of protective device that would provide greater security than a simple deterrent to mischief, yet still could be forcibly removed in an emergency, would be desirable. On other water lines which are not used for emergency applications such as firefighting, a greater degree of security would be desirable. Main water valves for residential housing is another example of where an economical yet efficient valve security device would be very desirable in order to prevent non-paying customers from simply disabling the lock typically placed on such valves by the water company with a simple hammer. In hazardous chemical lines and other applications, maximum security protection devices for the valves would be desired wherein the application of virtually any degree of force would still leave the valve disabled and inoperable. It would be highly desirable if a valve security device could be developed that would meet these different needs. Such a device would be readily adaptable for providing different levels of security for different applications. It would also be desirable if such a security device could be readily modified for use with different valve configurations. The present invention provides such a security device.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises a fluid flow valve security device that fits about and is secured to the actuating key on a valve head to selectively prevent access thereto and the unauthorized opening of the valve. The security device includes an inner body portion, an outer body portion, a protective sleeve, a valve cap and an operating pin assembly. The inner body portion is disposed about and operatively coupled to the valve actuating key such that rotation of the inner body portion effects corresponding rotation of the key to open and close the valve. The outer body portion of the security device is disposed about and rotatably mounted on the inner body portion. The valve cap is mounted atop the outer body portion for rotational movement therewith and defines a secondary actuating key thereon preferably corresponding in configuration to the actuating key on the valve head. The protective sleeve is secured between and freely rotatable about the interface of the inner and outer body portions and the actuating key on the valve head so as to prevent unauthorized access thereto.
The security device of the present invention is controlled by an operating pin assembly that is manually movable between an extended position and a retracted position. In its extended position, the pin assembly couples the outer body portion of the security device to the inner body portion thereof such that the secondary actuating key is operatively coupled to the actuating key on the valve head whereby the valve can be opened and closed by the secondary actuating key. If desired, with the operating pin assembly in the extended position the valve cap can be removed from the outer body portion to disassemble and remove the security device from the valve head. In the retracted position, the outer body portion is uncoupled from the inner body portion of the device and the valve cap is coupled to the outer body portion such that the outer body portion and valve cap are free wheeling on and about the inner body portion and the valve cap can not be removed from the outer body portion. Thus, with the operating pin assembly in the retracted position, the security device can not be removed from the valve head and the secondary key on the valve cap is not operatively coupled to the valve head key, totally disabling the fluid flow valve. The protective sleeve is also freely rotatable about the interface of the inner and outer body portions, preventing one from obtaining unauthorized access to said interface or the valve head actuating key in an effort to remove or overpower the security device.
To prevent unauthorized movement of the operating pin assembly from the retracted position to the extended position to open the valve and to inhibit the unauthorized locking of the valve in the operative mode, a channel is provided in an extended portion of the outer body of the device adjacent the operating pin assembly which, with the assembly in the retracted position, is adapted to receive the shackle of a padlock or tamper-proof lock having an inaccessible shackle, depending on the application. With the shackle extending through the channel, the operating pin assembly is held in the retracted position disabling the valve. With the operating pin assembly in the extended position, the channel is blocked by the pin assembly preventing the insertion of a lock shackle and the disabling of the valve.
Through the aforesaid configuration, when the valve security device of the present invention is used to secure a valve of the type that might need to be opened in an emergency situation such as a fire hydrant, a conventional padlock could be used to secure the operating pin assembly and a fireman, policeman or other person, in an emergency, could cut or saw through the shackle of the padlock to remove the lock and reestablish control over the valve head. For those applications in which higher security is required, a tamper-proof lock employing, for example, an inaccessible T-shaped shackle could be utilized which would prevent one from overcoming the lock without the key. Thus, the present invention provides a highly versatile locking device for use in a wide variety of applications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the valve security device of the present invention in place on a valve head. The valve security device is illustrated in FIG. 1 in the operative position, allowing the valve head to be moved between an open and closed position.
FIG. 2 is a top plan view of the locking device of the present invention in place on a valve head in the operative position, utilizing solid and phantom lines to show the movement of the device between a valve open position (solid lines) and valve closed position (phantom lines).
FIG. 3 is a perspective view of the valve head without the locking device mounted thereon, utilizing solid and phantom lines to illustrate the movement of the actuating key on the top of the valve head between the valve open position (solid lines) and valve closed position (phantom lines).
FIG. 4 is a sectional view of the valve security device of the present invention secured to the valve head and disposed in the operative position.
FIG. 5A is a partial sectional view taken along the line 5 A— 5 A in FIG. 4 .
FIG. 5B is a partial sectional view similar to 5 A but illustrating the valve security device in the inoperative position.
FIG. 6 is an exploded perspective view illustrating the components of the valve security device disposed above a valve head and including alternate embodiments of the valve cap showing the use of a handle and wheel for opening and closing the valve.
FIG. 7 is a perspective view of the valve head with only the inner body portion of the security device in place thereon.
FIG. 8 is a perspective view of the locking device of the present invention in place on a valve head with the valve cap removed.
FIG. 9 is a top plan view of the components illustrated in FIG. 8 .
FIG. 10 is a perspective view of the valve security device of the present invention secured on the valve head and locked in the disabled or free spinning or secured position.
FIG. 11 is a sectional view taken along the line 11 — 11 in FIG. 10 .
FIG. 12 is a sectional view taken along the line 12 — 12 in FIG. 11 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
The valve security device 10 is shown in the accompanying drawings secured to a conventional residential angle stop valve head 12 of the type that is widely used by the Department of Water and Power in the Southern California area and elsewhere. It is to be understood, however, that the security device of the present invention is readily adaptable for use with a variety of fluid flow valves. The valve head 12 includes a water inlet 14 , outlet 16 and a key or actuator 18 for actuating the internal valve components (not shown) to regulate the water flow therethrough. The open valve position is illustrated in FIG. 3 in solid lines and the closed position is illustrated in phantom lines.
The individual components of the valve security device 10 are perhaps best illustrated in the exploded view of FIG. 6 . Those components include an inner body 20 which is adapted to fit over and engage the actuator key 18 on the valve head 12 . As seen in FIG. 4 , the interior of inner body 20 is configured to engage and, as shown, preferably mate with the surfaces of the valve actuator key 18 . For valves having differently sized and/or configured actuators, the inner body portion 20 of the security device 10 would have correspondingly sized and configured interior contact surfaces. For the valve shown in the drawings, a retention pin 22 and a pair of set screws 24 provide the securement of the inner body 20 to the valve head 12 such that rotation of the inner body 20 effects corresponding rotation of the valve actuator 18 . The retention pin 22 extends through aperture 23 in the inner body portion 20 of the security device and through an aperture 25 formed in the valve actuator 18 to prevent the inner body 20 from being pulled from the valve head. This securement is also illustrated, for example, in FIG. 4 . The inner body 20 also defines a recess or slot 26 which is adapted to selectively receive the inner head portion 27 of the operating pin 28 to effect an operative coupling of the inner body to the outer body 34 of the security device 10 for rotation of the valve head actuator 18 with the security device 10 in place as will be described.
A threaded aperture 30 is provided in an upwardly projecting boss 31 on the inner body 20 which is adapted to receive an Allen screw 32 for securement of the outer body 34 to the inner body 20 . A washer 36 is disposed between boss 31 and the head of fastener 32 . Alternatively, the head of screw 32 could be enlarged to effect the securement of the outer body of the security device 10 to the inner body. A free spinning protective cylindrical metal sleeve 38 is provided between the valve head 12 and the outer body 34 to prevent unauthorized access to valve head area 40 (see FIG. 6 ) which might otherwise be gripped by a suitable tool and forcibly rotated to effect unauthorized opening of the valve head 12 . An anti-friction disc 41 formed of Teflon® or similar low friction material is provided on the annular flat surface 43 of the inner body 20 for reasons to be noted later herein. A valve cap 42 is secured to the upper end of the outer body 34 to prevent unauthorized disassembly of the valve security device and to provide a secondary key or actuator 44 for the opening and closing the valve head 12 . The valve cap 42 is secured to the outer body by a threaded fastener 46 and by means of a cap retaining pin 48 . The secondary actuator 44 carried by cap 42 can be of the identical configuration as the valve head actuator 18 or, if desired, of an elongated or circular configuration (also shown in FIG. 6 ), or of any other desired shape.
As perhaps best seen in FIGS. 4 and 5 , the valve cap retaining pin 48 projects from the underside of the valve cap 42 , through an aperture 50 in the upper end of the outer body 34 and into an interior area 52 proximate the slot 26 in the inner body 20 . The outer body 34 of the security device 10 additionally includes a hollow, radially projecting arm portion 54 defining an elongated interior chamber 56 communicating with interior area 52 . The operating pin 28 is slidably disposed within chamber 56 and area 48 as seen in FIGS. 4 and 5 . A lubrication nipple 58 threadably engages the extended end of arm portion 54 so as to close the outer end of chamber 56 such that a coil spring 62 can extend between the lubrication nipple 58 and a seat 64 formed in outer end portion 65 of the operating pin 28 . So disposed, the coil spring 62 continually urges the operating pin 28 to the inner or extended position seen in FIG. 5 . A handle 66 for selectively moving the operating pin 28 between an inner and outer position is threadably secured to the operating pin. An L-shaped slot 68 is provided in the arm portion 54 of the outer body 34 to accommodate handle 66 and hold the operating pin 28 in the outer or retracted position when the handle is pushed downwardly into the offset portion 68 ′ of slot 68 .
The operating pin 28 defines a reduced diameter portion 70 between its head portion 27 and end portion 65 . Similarly, the vertically disposed cap retaining pin 48 defines a reduced diameter portion 72 intermediary of its ends. The reduced diameter portion 72 of the cap retention pin 48 is disposed within the interior area 52 of the outer body as seen in FIG. 4 . In the fully extended position illustrated in FIGS. 4 and 5A , the head portion 27 of the operating pin 28 projects into the slot 26 in the inner body 20 , operatively connecting the outer body 34 to the inner body 20 . In the fully retracted position, see FIGS. 5 B and 10 – 12 , the head portion of the operating pin is withdrawn from slot 26 , allowing the outer body 34 to rotate freely about the inner body 20 .
Referring again to FIGS. 4 and 5A , the outer body 34 is secured to the inner body 20 by virtue of the projection of the head portion 27 of operating pin 28 into the slot 26 in the inner body. The valve cap 42 is in turn secured to the outer body by virtue of threaded fastener 46 and cap retaining pin 48 . Accordingly, engaging the actuator 44 defined by valve cap 42 with the appropriate tool and rotating the cap will effect corresponding rotation of the outer body 34 and inner body 20 . The engagement of the valve head actuator 18 by the inner body 20 effects corresponding rotation of the valve head actuator 18 such that the valve head 12 can be effectively operated by the actuator 44 on the valve cap 42 . As indicated above, the key-shaped actuator 44 could be replaced by a suitable handle, valve wheel or other configuration as seen in FIG. 6 .
In the above described operative mode, the valve cap 42 can be readily removed to disengage the security device 10 from the valve head 12 for repair and replacement purposes. This is accomplished by simply unscrewing the threaded fastener 46 and lifting the valve cap vertically off the outer body 34 . Such removal is permitted due to the positioning of the reduced diameter portion 70 of the operating pin 28 relative to the reduced diameter portion 72 of the cap retaining pin 48 such that the operating pin does not obstruct the upward movement of the retaining pin. If the larger diameter head portion 27 of the operating pin were in the path of pin 48 , as is the case in the inoperative mode when the operating pin is in the retracted position (see FIG. 5B ), the head of the operating pin would prevent withdrawal of the retaining pin 48 preventing removal of the valve cap 42 .
To lock the valve security device 10 such that the valve head cannot be opened without authorization, the operating pin 28 is urged outwardly against the force of spring 62 by means of handle 66 , disengaging the head portion 27 of pin 28 from the slot 26 in the inner body portion 20 . By pressing the handle 66 downwardly in the retracted position, the handle will move into the offset portion 68 ′ of the L-shaped slot 68 so as to hold the operating pin 28 in its retracted position. Because of the reduced diameter portion 72 of the cap retaining pin 48 , pin 48 does not obstruct the outward movement of the operating pin 28 as just described. With the operating pin in the retracted position, the locking channel 80 formed in the arm portion 54 of the outer body 34 is no longer partially obstructed by the end portion 65 of the operating pin 28 as is the case when the pin is in the extended position (see FIGS. 5A and 5B ). This allows the bar, pin or shackle 82 on a lock 84 to be inserted through channel 80 and locked in place as seen in FIGS. 10–12 . For low security applications, a conventional padlock would be used with the valve security device and the shackle of the lock would be inserted through the locking channel 80 as is shown in the drawings. It is to be understood that higher security locks would be utilized with security device 10 for higher security applications, as will be later discussed. The operation of the valve security device 10 will be discussed with reference to a lock 84 and its associated locking bar 82 although it is to be understood that the term “locking bar” or “bar” is intended to include shackles, pins, locking bolts, etc. so as not to unduly restrict the types of locks with which the security device 10 of the present invention can be used.
With the lock 84 in place, the outer body 34 of the security device, the lock 84 and the valve cap 42 are free wheeling about the inner body 20 . Thus, rotation of the actuator 44 on the valve security device 10 simply rotates the outer body 34 of the device but does not effect corresponding rotation of the inner body 20 . The outer body 34 and lock 84 cannot be lifted from the inner body 20 due to the threaded engagement of the hidden fastener 32 which, while allowing relative rotation between the inner and outer bodies, holds the outer body to the inner body. Upon removal of the exposed threaded fastener 46 , the valve cap 42 is still held in place, preventing access to fastener 32 , due to the interference created between the head portion 27 of the operating pin 28 and the cap retaining pin 48 . The cap retaining pin 48 is prevented from being withdrawn from outer body 34 through aperture 50 therein by the larger diameter head portion of the operating pin as shown in FIGS. 11 and 12 . Because of the interference created by the operating pin, the cap cannot be removed and thus the valve head 12 is effectively disabled due to the free spinning cap and outer body and the lack of any operative engagement of the cap 42 to the inner body 20 .
The inclusion of the low friction disc 41 on the flat annular surface 43 of the inner body will prevent one from being able to operate the valve head by using an elongated lever arm on actuator 44 and attempting to torque one side of the cap 42 and outer body 34 downwardly with respect to the inner body 20 such that underside of the outer body would bear against surface 43 with sufficient force to enable one to actually turn the inner body and thus circumvent the security device. With the low friction disc 41 covering inner body surface 43 , sufficient friction could not be generated on the inner body to operate the valve head in such a manner.
In order to reconnect the operative engagement between the valve security device 10 and the valve head 12 , it is necessary to remove the lock 84 . With the lock in place, the locking bar 82 prevents the larger diameter outer end portion 65 of the operating pin 28 from passing thereby and thus prevents any inward movement of the pin 28 into engagement with the inner body 20 . With the lock removed, the coil spring 62 will urge the operating pin 28 against the inner body 20 . By simply rotating the outer body 34 relative to the inner body, the head portion 27 of the operating pin will come into alignment with the slot 26 in the inner body 20 , whereupon the coil spring 62 will urge the head 27 of the operating pin 28 into slot 26 , reestablishing the operative connection between the inner and outer bodies of the security device.
The removal of lock 84 from device 10 can be accomplished in its intended way through the use of the lock key. Alternatively, in an emergency situation, a fireman, policeman or other person, could cut or saw through the locking bar of the lock to remove the lock and reestablish control over the valve head 12 assuming that a lower security lock such as a convention padlock were used to secure device 10 . The ability to reestablish such a connection when the key is not available is quite important in many applications where an emergency situation dictates reactivation of the valve head. For those applications in which higher security is required, a tamperproof lock employing, for example, a T-shaped locking bar could be utilized which would prevent one from overpowering the lock without the key without destroying the valve as well. Such applications would be for very high security applications where the use of the key was deemed absolutely necessary by the end user.
Various changes and modifications also may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the purview of the appended claims, they are to be considered as part of the present invention. | A valve security device for releasably securing a fluid flow valve in an inoperable position including an inner body adapted to be disposed about the valve actuator such that rotation of the inner body effects corresponding rotation of the actuator to open and close the valve and an outer body rotatably mounted about the inner body. A valve cap defining a secondary actuator is mounted on the outer body. An operating pin assembly is carried by the outer body which, in an extended position, operatively couples the outer body to the inner body such that the valve can be controlled by the secondary actuator. In a retracted position, the pin assembly uncouples the outer and inner bodies such that the outer body is freely rotatable on the inner body. A lock secures the operating pin assembly in the retracted position thereby releasably securing the valve in an inoperable position. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to signalling devices for vehicles of the type in which steering is accomplished by varying the speed and/or reversing the rotation of wheels or other propelling elements on separate sides of the vehicle, and more particularly to a signal actuating device for hydrostatically propelled vehicles of the skid-steer type.
2. Description of the Prior Art
The prior art includes Albright et al., U.S. Pat. No. 4,043,416, of common assignee, that discloses both the general vehicle and the mechanical elements thereof that cooperate with elements of the present invention.
SUMMARY OF THE INVENTION
In accordance with the broader aspects of this invention, there is provided a signal actuating device for a vehicle of the type having left and right rotary propelling elements that preferably comprise wheels and that are proximal to opposite sides of the vehicle, a source of power that preferably comprises an internal combustion engine, means, which preferably comprises hydrostatic propulsion units, for supplying power to the propelling elements or wheels, and first and second manual control devices that preferably comprise first and second manual control levers or hand levers, and that are connected to the means for supplying power. The first and second manual control devices control both the direction of rotation and the rotational speed of respective ones of the rotary propelling elements in response to the direction of movement and the magnitude of movement of manual control signals that are applied to respective ones of the hand levers, thereby selecting forward or reverse motion, selecting speed of motion, and providing steering control.
The first and second manual control devices, in addition to the manual control levers, include a pair of spaced-apart control bars that connect the manual control levers to the hydrostatic propulsion units.
The signal actuating device includes a summing bar that senses and sums the respective positions of the control bars, and an electrical switch that is actuated in accordance with the summed positions of the control bars.
It is a first object of the present invention to provide a signal actuating device for vehicles of the type wherein steering is achieved by separately varying the speed and/or the direction of propulsion of opposite sides of a vehicle.
It is a second object of the present invention to provide a signal actuating device for hydrostatically propelled vehicles of the type wherein steering is achieved by separately varying the speed and/or direction of rotation of fluid motors that provide propulsion power to opposite sides of the vehicle.
It is a third object of the present invention to provide a signal actuating device which mechanically senses and mechanically sums parameters that are indicative of the direction of rotation and rotational speed of propelling devices on opposite sides of a vehicle and which actuates a switch or other device according to predetermined conditions of rotational direction and speed.
It is a fourth object of the present invention to provide a signal actuating device which comprises a transversely disposed summing bar that senses the positions of two parallel disposed control bars and that actuates a switch or other device according to predetermined combinations of locations of the control bars.
These and other advantages and objects of the present invention will be readily apparent when referring to the following detailed description wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a mobile shovel loader of the wheeled skid-steer type which is described for use with, and as a part of, the present invention;
FIG. 2 is a schematic view of the hydrostatic propulsion system and manual control devices for the vehicle of FIG. 1, taken substantially as a top elevation, but with a portion of the manual control devices shown in perspective for better clarity;
FIG. 3 is a top view of a portion of the manual control devices with the tandem pumps of the hydrostatic propulsion unit shown in phantom lines, taken substantially as shown in the schematic drawing of FIG. 2;
FIG. 3A is a partial and enlarged view of FIG. 3, showing the maneuver signalling switch and mounting bracket thereof;
FIG. 3B is a partial and enlarged view of FIG. 3, showing a portion of one of the control bars and one of the actuating cams; and
FIG. 4 is a side elevation of a portion of the manual control devices with the tandem pumps of the hydrostatic propulsion unit shown in phantom lines, taken substantially as shown by view line 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, vehicle 10 includes a frame 12 having a first side 14 and a second side 16, first and second rotary propelling elements or wheels 18a and 20a, and first and second manual control levers or hand levers, 22 and 24.
Referring now to FIG. 2, vehicle 10 of FIG. 1 includes a hydrostatic propulsion system 26 which includes a tandem pump 28 having a first variable and reversible flow fluid pump 30 and a second variable and reversible flow fluid pump 32 and which includes both a first fluid motor 34 and a second fluid motor 36 that are connected to respective ones of the pumps 30 and 32 by conduits 38. Tandem pump 28 is connected to and driven by a source of mechanical power 40 which preferably comprises an internal combustion engine. The fluid motor 34 drives the wheel 18a by a chain 41a and a wheel 18b is driven by a motor 34 and a chain 41b. In like manner, the fluid motor 36 drives the wheel 20a by a chain 42a and drives a wheel 20b by a chain 42b.
The pumps 30 and 32 are of the axial piston type in which both the displacement and direction of fluid flow are controlled by manually positioning a swash plate (not shown) that controls the stroke of the pistons (not shown). This type of pump is well-known in the art and does not constitute a part of the present invention. In FIG. 2, bell cranks 44 and 46 are schematically illustrated as the mechanical means for controlling the angular positions of the swash plates (not shown).
Referring again to FIG. 2, vehicle 10 of FIG. 1 includes a first manual control device 48 and a second manual control device 50. The manual control device 48 includes the manual control lever or hand lever 22, a torque shaft or torque tube 52, a bell crank 54, an elongated control bar 56 which is symbolically illustrated by a phantom line in FIG. 2 and which is shown in FIGS. 3 and 4, and the bell crank 44. In like manner, the second manual control device 50 includes the control lever 24, a torque shaft or torque tube 57, a bell crank 58, an elongated control bar 60 which is illustrated by a phantom line in FIG. 2 and which is shown in detail in FIGS. 3 and 4, and the bell crank 46.
Referring now to FIGS. 3 and 4, the variable and reversible flow fluid pumps 30 and 32 of the tandem pump 28 are shown in phantom lines with the exception of swash plate shafts 62 and 64 which are shown by solid lines. The bell cranks 44 and 46 are positioned in upstanding directions and are clamped to respective ones of the swash plate shafts 62 and 64 by bolts 66. The first elongated control bar 56 is connected to the bell crank 44 distal from the swash plate shaft 62 by a bolt 67; and the elongated control bar 60 is connected to the bell crank 46 distal from the swash plate shaft 64 by a bolt 68. The control bar 56 is also connected to the bell crank 54 by links 70 and the control bar 60 is connected to the bell crank 58 by links 72.
The control bars 56 and 60 are preferably of substantially rectangular cross-sections, each having a pair of narrow sides 59 and each having a pair of wide planar sides 61. The control bar 56 includes a slot 74 that allows the control bar 56 to move independently of the control bar 60 even though the bolt 68 projects through the control bar 56.
The preceding elements are explained in greater detail in U.S. Pat. No. 4,043,416 of common assignee which is included in the present specification by reference herein thereto. Lugs 71, bracket 73, and spring 75 which cooperate to provide a centering force for the swash plate shafts 62 and 64, and the interconnection of the control lever 24 and the torque tube 57 which includes a push rod 76 and which is generally depicted at 78, do not form a part of the present invention and so are not described herein.
Referring now to FIGS. 3, 3A, 3B, and 4, a signal actuating device 80 includes the manual control devices 48 and 50 which in turn include respective ones of the control levers 22 and 24 (FIGS. 1 and 2), the torque tubes 52 and 57, the bell cranks 54 and 58, the control bars 56 and 60, and the bell cranks 44 and 46.
The signal actuating device 80 further includes a switch actuator means 82 which comprises a summing bar 84 having ends 86 and 88 and having a hole 87 intermediate of the ends 86 and 88, a first actuating cam 90, a second actuating cam 92, hole or elongated slot 94 in the control bar 56, and an identical hole or elongated slot 96 in the control bar 60.
The signal actuating device 80 further comprises a mechanically actuated signalling switch or maneuver signalling switch 98 having a switch body 100, having a rotary actuating shaft 102 that is mounted in the switch body 100 for rotation about an actuating shaft axis 104, and having a switch actuating lever 106 which is secured to the rotary actuating shaft 102. The switch 98 includes a bracket 99 and a bolt 101 secures the switch 98 to a structural angle 103, the switch 98 being positioned with the actuating lever 106 extending upwardly through the hole 87 of the summing bar 84.
The cams 90 and 92 are each made from a substantially rectangular strip of sheet metal and each includes a hole 108 in a mid portion 110, a camming portion 112 that is bent outwardly, and a reduced width portion or tang 113 that is bent inwardly to engage a respective one of the elongated slots 94 and 96. Thus the cams 90 and 92 can be moved longitudinally, and can be secured by bolts 116, to engage the summing bar 84 at predetermined positions of the control bars 56 and 60, engaging the switch actuating lever 106 by the periphery of the hole 87 in the summing bar 84, through which the switch actuating lever 106 extends.
Referring now to FIGS. 2, 3, and 4, in operation, the levers 22 and 24 are actuated in the direction of arrow 118 to actuate the bell cranks 44 and 46 to a position that inclines the swash plate shafts 62 and 64 for forward propulsion of the vehicle 10. At this time, the length and position of the elongated slots 94 and 96 allow movement of the control bars 56 and 60 without interaction between the slots 94 and 96 and the summing bar 84. When the control levers 22 and 24 are moved in the direction of an arrow 120, the swash plate shafts 62 and 64 are positioned to reverse the flow of fluid from the pumps 30 and 32 to respective ones of the motors 34 and 36, rotating the wheels 18a and 20a in the reversedirection. At this time, the actuating cams 90 and 92 engage the summing bar 84 intermediate of the hole 87 and respective ones of the ends 86 and 88 of the summing bar 84, rotating the switch actuating lever 106 in the direction of an arrow 122 and closing an electrical contact (not shown) in the switch body 100.
Since the summing bar 84 is effective to sum the mechanical movements of the control bars 56 and 60, it can be seen that the actuating cams 90 and 92 can be positioned with respective ones of the bolts 116 to actuate the switch 98 under predetermined conditions of backing or backward turns.
While only a single embodiment of the present invention has been described in detail, it will be understood that the detailed description is intended to be illustrative only and that various modifications and changes may be made to the present invention without departing from the spirit and scope of it. Therefore the limits of the present invention should be determined from the attached claims. | A signal actuating device is provided for vehicles of the skid-steer type. The actuating device includes a summing bar that mechanically sums the positions of two manual control bars and that actuates a switch to warn pedestrians when the vehicle is backing up or doing other maneuvers that are potentially dangerous to pedestrians. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 12/898,436 filed Oct. 5, 2010 that in turn claims priority of U.S. Provisional Patent Application Ser. No. 61/248,636 filed Oct. 5, 2009, the contents of these applications are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention in general relates to a one part polymerizable formulation well suited for coatings and in particular to free radical initiated polymerizable formulations that are stabilized in part through solvent dilution.
BACKGROUND OF THE INVENTION
The protection of a surface with a polymeric coating requires extensive removal of surface debris, grease, and other liquids from the surface, else the applied coating will have poor adhesion that reduces the coating lifetime and exposes the substrate to environmental exposure. These difficulties are compounded when higher molecular weight polymer precursors are used that, owing to size and conformational limitations, are unable to permeate well into a porous or scaly substrate. A further complication of coating a surface with a polymerizable formulation entails mixing of a two part formulation to initiate the polymerization reaction and coating formation. As a result, the formulation must be applied on a timetable consistent with cure rate and also take into account the ever-increasing viscosity of the formulation upon combination of the formulation parts. The use of a two part polymerizable formulation largely precludes spray application as curing tends to foul spray nozzles. Additionally, upon initiating polymerization of a two part formulation, any unused formulation is wasted.
Owing to these limitations, there exists a need for a one part, storage stable polymerizable formulation. Such a formulation is amenable to spray, roll or brush application.
SUMMARY OF THE INVENTION
A one part, storage stable polymerizable formulation is provided that includes an ethenically unsaturated polymerizable compound intermixed with an optional free radical polymerization initiator and an organic solvent. The organic solvent provides storage stability and upon evaporation of the solvent, the rate of polymerization of the compound accelerates independent of addition of a second part. The formulation includes at least 30 total weight percent solids upon cure. Optional additives to the formulation include at least one of a cure accelerator, a filler, a plasticizer, a colorant, and a cure inhibitor. A process for forming a polymerized coating on an article involves the application of this formulation to the substrate of an article and allowing sufficient time for the solvent to evaporate to form the polymerized coating on the article. The substrate of the article forms a corrosion barrier even without prior removal of a native corrosion layer on a surface of the substrate of the article.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has utility as a polymerizable formulation from which a coating is formed upon application to a substrate. According to the present invention, storage stability is obtained in a one part polymerizable formulation through the inclusion of a quantity of solvent sufficient to dilute an ethenically unsaturated polymerizable compound and an initiator and/or catalyst to concentrations at which the polymerization is arrested. As a result, consistent viscosity formulation is applied and only upon dissipation of the organic solvent and exposure to air does polymerization of the inventive formulation kinetically accelerate. As a result, an inventive formulation is applied with a consistent viscosity and unused formulation is readily stored for further usage. Through selection of monomeric ethenically unsaturated polymerizable compounds, an inventive formulation is able to penetrate the surface of a fouled substrate prior to polymerization thereby allowing for protective coating to be applied to a substrate with lessened or no substrate preparation prior to application of the inventive formulation. Representative fouled substrates to which an inventive formulation are directly applied illustratively include corroded metals such as rusted steel, oxidized aluminum, anodized aluminum, pickled steel, stainless steel, painted metals, and hot dipped galvanized steel, Galfan, Galvalume, Zincalume; cement; concrete; wood substrates such as painted wood, partially rotted wood, fabrics, drywall and plastics with porous surfaces as well as fiberboard. An inventive formulation is particularly well suited for formulation as an aerosol with a propellant. An attribute of a coating produced by an inventive formulation is that an air and moisture barrier is formed that inhibits subsequent corrosion of a substrate, even when already overlayered with a corrosion layer.
An ethenically unsaturated polymerizable compound operative in the present invention includes a carbon-carbon double bond referred to synonymously herein as point of ethenic unsaturation. Operative moieties found within an inventive ethenically unsaturated polymerizable compound include allylic moieties of the formula:
Y—X—(CR 2 —RC═CR) n —R (I)
where R in each occurrence is independently H, C 1 -C 4 alkyl, C 1 -C 4 perfluoroalkyl, C 6 aryl, C 6 aryl having at least one substituent of C 1 -C 4 alkyl; n is an integer of 1 to 50; and X is oxygen or R, Y is a nullity or a polymeric resin backbone of acrylic, oligomeric ester of up to 30 repeat units, polyester, epoxy, polyether, alkyd, polyurethane. It is appreciated that an oligomer or resin backbone may contain only a single allylic moiety, two or multiple such moieties per structure (I) in the context of the present invention. In a preferred embodiment R in each occurrence is H.
Acrylate moieties are also operative in an ethenically unsaturated polymerizable compound of an inventive formulation and have the general formula:
Y—R—O(O)C—RC═CR 2 (II)
where R and Y are defined as above with respect to Formula (I). Methacrylate moieties of the formula YRO(O)C—CH 3 C═CH 2 are particularly preferred in an inventive formulation and noted to have a reduced reactivity relative to a corresponding purely protonated allylic and acrylate compound. As a general trend of reactivity allylic>acrylate>alkyl acrylate>aryl acrylate. Reactivity rates of a given ethenically unsaturated polymerizable compound are a factor in controlling storage stability of a formulation.
It is appreciated that inclusion of a mixture of compounds per structure (I) are readily prepared as an inventive formulation to optimize initial viscosity, storage stability, cure time, resultant coating hardness, and substrate adhesion characteristics. By way of example, an epoxy of formula (I) is noted to be well suited to improve adhesion to clean metal substrates such as aluminum and steel.
Representative ethenically unsaturated polymerizable compounds operative herein illustratively include methyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, trimethyl cyclohexyl methacrylate, cyclohexyl methacrylate, methacrylic acid, isobornyl methacrylate, ethoxyethyl methacrylate, 2-ethylhexyl methacrylate, and dicyclopentenyl oxyethyl methacrylate. Typical polyfunctional monomers include, but are not limited to, methacrylate esters of polyethylene glycols, such as the esters of triethylene glycol 1,6-hexane dial, polypropylene glycol, 1,3- and 1,4-butylene glycol and 1,12-dodecanediol, trimethylol propane trimethacrylate, ethoxylated bisphenol A dimethacrylate.
Representative ethenically unsaturated materials may also include a suitable unsaturated alkyd. Alkyds are prepared from polyols, dibasic acids and fatty acid. They are essentially oil modified polyesters. Alkyds are classified into oxidizing or nonoxidizing types. Oxidizing alkyds cross-link through air oxidizing polymerization. Alkyds can be further segmented into the amount of saturated or unsaturated oil that is used. For example, alkyds with an oil length of greater than 60% are long oil alkyds, oil lengths between 40 and 605 are known as medium oil alkyds and alkyds with less than 40% are known as short oil alkyds. Examples of unsaturated fatty acids for use to form alkyds that may be combined with suitable polyols and dibasic acids include soya, safflower and sunflower. Alkyds that contain suitable unsaturated fatty acid drying oils or other suitable ethenically unsaturated materials can be used in conjunction with other ethenically unsaturated compounds in subject invention.
Polymerization initiator is provided in an inventive formulation to commence a free radical polymerization reaction so as to form covalent bonds between the ethenically unsaturated polymerizable compounds. Free radical initiators operative herein illustratively include ketone peroxide, diacyl peroxide, perester, perketals, diacyl peroxides, peroxydicarbonates, and hydroperoxide. Selection of a given initiator from among those listed above is dependent on factors such as the desired activation temperature of the inventive formulation, solubility of the initiator inventive formulation through appreciation that soluble initiators undergo homogeneous reaction catalysis that tends to be faster than that of insoluble initiators; and initiator degradation products. With respect to these factors, it is appreciated that initiator stability is dependent on energy activation associated with steric hindrance and resonant structure stability. With respect to products of degradation, initiators typically degrade to reduced product less an abstracted oxygen atom. Stability of the substrate towards this degradation product represents a consideration in creation of an inventive formulation. By way of example, dibenzoyl peroxide generates a primary degradation product of benzoic acid. Additionally, creating an inventive formulation, the inclusion of water within an organic solvent diluent is also a consideration as water typically reduces the effective cure rate and is often less volatile than an organic solvent. By way of an example, a free radical polymerization initiator having solubility in both water and organic solvent tends to be more stable and therefore less reactive in the presence of water. Representative initiators operative herein illustratively include those organic hydroperoxides having the formula ROOH wherein R 6 is a hydrocarbon radical containing up to about 18 carbon atoms, preferably an alkyl, aryl, or aralkyl radical containing from one to 12 carbon atoms. Typical examples of such hydroperoxides are cumene hydroperoxide, tertiary butyl hydroperoxide, methyl ethyl ketone peroxide, and hydroperoxides formed by the oxygenation of various hydrocarbons, such as methylbutene, cetane, and cyclohexene, and various ketones and ethers. Other examples of useful initiators include hydroperoxides such as p-methane hydroperoxide, 2,5-dimethylhexane, and 2,5-dihydroperoxide. The initiator is typically present from 1 to 6 weight percent of the polymerizable compound, with from 2 to 4 weight percent of the polymerizable compound being preferred.
An organic solvent is present in an inventive formulation as a nonreactive diluent for the ethenically unsaturated polymerizable compound and free radical initiator so as to impart storage stability to the mixture of polymerizable compound and initiator. A suitable organic solvent is nonreactive with the polymerizable compound and initiator under storage and polymerization conditions. Preferably, the organic solvent is not a volatile organic compound (VOC) as defined by the U.S. Environmental Protection Agency. Suitable organic solvents operative herein illustratively include methyl acetate, methyl ethyl ketone, toluene, tetrahydrofuran, aromatic 100, C 2 -C 6 acetates such as n-propyl acetate, t-butyl acetate, and n-hexyl acetate, and other ketone and ester based oxygenated solvents. The organic solvent is selected so as to impart solubility on the polymerizable compound and preferably on the free radical initiator as well. Preferably, an acetate constitutes a majority component of the organic solvent present. The organic solvent is typically present from 1 to 40 weight percent of a fully formulated inventive formulation. Organic solvent or mixture of solvents is selected not only to solubilize the polymerizable compound but also to volatilize rapidly relative to the polymerization rate as residual solvent can diminish the barrier properties of a coating formed from an inventive formulation. Preferably, the organic solvent is present from 1 to 50 total weight percent. More preferably, the organic solvent is solely an acetate present from 5 to 40 total weight percent. In the event that water is optionally added to the organic solvent, water is typically present from 1 to 10 total weight percent and preferably from 2 to 8 total weight percent.
Optionally, a cure accelerator is provided to modify the kinetics and progression of the polymerization process. Accelerators operative herein include salts of transition metals such as vanadium, molybdenum, cobalt, iron, zirconium, or copper. Of these transition metals, a combination of cobalt and manganese is known to the art to promote surface cure relative to through cure while zirconium or a combination of cobalt and zirconium facilitates through cure. Cobalt accelerators, zirconium accelerators, and a combination thereof are known to induce oxidation. Suitable accelerator salts operative herein include naphthenates, acetyl acetonates, and 2-ethyl hexanoic acid. Accelerators, if present, are found in an inventive formulation in an amount from 0 to 10 total weight percent and preferably between 0.01 and 1 total weight percent of the transition metal salt itself.
In instances when an accelerator is present, an anti-skinning agent such as an aliphatic keto oxime is provided to control surface oxidation associated with transition metal accelerator. Other anti-skinning agents are available as well as phenolics as well as nonphenolics and oxime free anti-skinning agents from suppliers such as OMG trade named Ascinin may also be used. Representative aliphatic keto oximes include methyl ethyl keto oxime, methyl propyl keto oxime, methyl terbutyl keto oxime, and methyl isobutyl keto oxime. Typically, an aliphatic keto oxime is present from 0.2 to 3.0 total weight percent and is preferably present in concert with a cobalt-based accelerator. Cobalt-aliphatic keto oxime combinations are also known in the art to accelerate cure rates.
Other optional additives to an inventive formulation illustratively include fillers, plasticizers, colorants, and cure inhibitors.
Fillers operative in an inventive formulation illustratively include particulate of silica, glass microspheres, calcium carbonate, talc, mica clay, diatomaceous earth, glass microspheres, polymeric microspheres, and combinations thereof. A filler is typically present from 0 to 20 total weight percent of a formulation. Fillers are appreciated to affect the hardness of a resultant coating formed from an inventive formulation and modify the rheology of the formulation.
An optional plasticizer is provided to modify the hardness of a resultant coating formed from an inventive formulation. A plasticizer is typically present from 0 to 10 total weight percent and preferably from 1 to 5 total weight percent. Plasticizers operative herein include phthalates such as diethyl, dibutyl, dibenzyl, and mixed benzyl-alkyl, and combinations thereof.
An optional colorant is provided to modify the hardness of a resultant coating formed from an inventive formulation. A colorant is typically present from 0 to 50 total weight percent and preferably from 2 to 25 total weight percent. Colorants operative herein include organic, inorganic and mixed metal oxide pigments such as carbon black, titanium oxide, phthalol blue, quinacridone red, red iron oxide, copper chrome black, as well as soluble or insoluble dyes and combinations thereof.
An optional cure inhibitor is provided to modify the hardness of a resultant coating formed from an inventive formulation. A cure inhibitor is typically present from 0 to 5 total weight percent and preferably from 0.1 to 3 total weight percent. Cure inhibitors operative herein include phthalates such as diethyl, dibutyl, dibenzyl, and mixed benzyl-alkyl, and combinations thereof.
An inventive formulation is able to penetrate a corrosion overlayer and bond to an underlying substrate. Preferably, the cross-linking density is such that an inventive coating forms an air and moisture barrier to inhibit subsequent corrosion. To achieve such a result, preferably an inventive formulation is greater than 30 total weight percent solids as measured by heat cured weight relative to the as-applied formulation. More preferably, the formulation is greater than 50 total weight percent solids upon cure and most preferably is between 60 and 92 total weight percent solids. It is appreciated that higher percent solids formulations tend to have higher initial viscosities and higher coating densities relative to lower percent solids.
It is appreciated that only a thin coating of between 10 and about 500 microns is needed to adequately protect a typical substrate. While an inventive formulation is readily applied to a substrate by swabbing or pump spray, it is appreciated that coating uniformity is readily obtained by application from a spray aerosol, such as from a can. As such, a propellant is optionally added in a range from 5 to 95 total weight percent with the proviso that the propellant and diluent solvent together do not exceed 97 total weight percent of the formulation. Suitable propellants include those that are unreactive towards the capped silanol fluid and illustratively include alkanes such as butane, pentane, isobutane, propane; ethers such as dimethyl ether, diethyl ether, nitrogen; halogenated hydrocarbons; carbon dioxide and combinations thereof. The resultant formulation inclusive of a propellant is sealed within a conventional metal aerosol canister and applied by spray application.
Upon complete cure, typically greater than 72 hours, an inventive coating is amenable to reapplication of an inventive formulation or a conventional paint application. Suitable paints include oil-based, latex, and water-based paints.
The present invention is further detailed with respect to the following nonlimiting examples.
Example 1
Thirty-five grams of trimethylol propane trimethacrylate are combined with 30 grams of 2 mol ethoxylated bisphenol A dimethacrylate and 20 grams of polyallyl glycidyl ether diluted with 10 grams of toluene. One gram of methacryloxypropyl trimethoxysilane is added along with 60 milligrams of cobalt 2-ethyl hexanate and 60 milligrams of zirconium 2-ethyl hexanate. Three grams of cumene hydroperoxide are added to the solvent diluted ethenically unsaturated compound mixture. One gram of methyl ethyl keto oxime is mixed into the inventive formulation. The inventive formulation is storage stable for more than 1 month at ambient temperature fluctuating between 10° and 28° Celsius. The resultant formulation readily penetrates a rusted steel object and forms a coating upon cure. A peel test on the cured coating performed at 20° Celsius attached the rust layer and exposed clean steel substrate.
Example 2
The formulation of Example 1 is repeated with an allyl functional aliphatic urethane replacing the ethoxylated bisphenol A methacrylate and t-butyl peroxy benzoate replacing cumene hydroperoxide at equivalent weight levels. The resultant formulation cured upon toluene volatilization on a corroded steel substrate to achieve a comparable coating.
Example 3
The formulation of Example 1 is repeated with toluene being replaced with 6 grains of methyl acetate and 4 grams of methyl ethyl ketone. A comparable coating is obtained upon dissipation of the methyl ethyl ketone and methyl acetate solvents on a rusted steel substrate.
Example 4
The formulation of Example 1 is repeated increasing the quantity of trimethylol propane trimethacrylate to 50 grams with a decrease in the amount of ethoxylated bisphenol A dimethacrylate to 22 grams. A comparison of formulation properties between Example 1 and Example 4 24 hours after formulation in a sealed container at 20° Celsius, 2 hours after application to a wood substrate at 600 Celsius, and on wood after 24 hours exposed to the environment at 20° Celsius is provided.
TABLE 1
Comparative Formulation
Properties
24 h @ 20° C.
2 h @ 60° C.
24 h @ 20° C.
Formulation
(sealed)
(wood)
(wood)
Example 1
liquid
hard
cured
Example 4
Gel
hard
cured
Example 5
The formulation of Example 1 is repeated with toluene being replaced with 24.5 grams of t-butyl acetate and the inclusion of 2.4 grams of carbon black. The resultant formulation is storage stable for more than 1 month at an ambient temperature fluctuating between 10° and 28° Celsius. The resultant formulation has a density of 1.03 kilograms per liter.
Example 6
Twelve grams of trimethylol propane trimethacrylate are combined with 31 grams of a long oil soya alkyd, and 10 grams of 2 mol ethoxylated bisphenol A dimethacrylate and 6 grams of polyallyl glycidyl ether diluted with 16 grams of t-butyl acetate. 0.6 gram of methacryloxypropyl trimethoxysilane is added along with 51 milligrams of cobalt 2-ethyl hexanate and 81 milligrams of zirconium 2-ethyl hexanate. 13 milligrams grams of methyl ethyl ketoxime are added to the solvent diluted ethenically unsaturated compound mixture. 7 grams of a carbon black pigment dispersion containing about 30% pigment is then added to the mixture. The inventive formulation is storage stable for more than 1 month at ambient temperature at 25° Celsius as well as 7 days at 120° Fahrenheit. The resultant formulation readily penetrates a rusted steel object and forms a coating upon cure. A peel test on the cured coating performed at 200 Celsius attached the rust layer and exposed clean steel substrate.
Example 7
The formulation of Example 6 is applied to cold rolled steel and is cured at 60° Celsius with complete cure at 16 hours. Temperature cure is noted in between 16 and 24 hours with the resultant inventive coating covered steel coupons being subjected to various tests. For comparison, the same steel coupons are coated with a conventional corrosion inhibition coating commercially available from Eastwood Company (Pottstown, Pa.). The Eastwood rust prevention solution is noted to dry in less than 8 hours to a comparable level of surface hardness and to be completely tack and fingerprint free. The test coupons were subjected to the following tests on separate coupons to determine coating attributes:
tensile hardness of cured film 72 hours after application via ASTM D3363 methyl ethyl ketone (MEK) double rub solvent resistance rub test per ASTM D4752 cyclic corrosion test per ASTM D6899 for 30 days through cycles of moisture, salt, and acid rain high humidity and temperature test 150 hours at 100% condensing humidity at 49° Celsius for 150 hours repeat of high humidity and temperature test for formulations applied on pre-rusted steel
A summary of the environmental coating testing is provided below in Table 2
TABLE 2
Summary of Environmental Coating Testing: Inventive
Coating (Example 5) and Comparative Coating
Example 6
Comparative
Pencil Hardness*
H
3B
MEK Double Rub
>100
3
Cyclic Corrosion
naked eye
rust, loss of
visually unchanged
adhesion, blistering
High Humidity/
naked eye
tarnish, rust
High Temperature
visually unchanged
Pre-rusted High Humidity/
naked eye
rust, loss of
High Temperature
visually unchanged
adhesion, blistering
*Pencil hardness hardest to softest: 6H > 5H > 4H > 3H > 2H > H > F > HB > B > 2E > 3B
Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.
The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention. | A one part, storage stable polymerizable formulation is provided that includes an ethenically unsaturated polymerizable compound intermixed with a free radical polymerization initiator and an organic solvent. The organic solvent provides storage stability and upon evaporation of the solvent, the rate of polymerization of the compound accelerates independent of addition of a second part. The formulation includes at least 30 total weight percent solids upon cure. Optional additives to the formulation include at least one of a cure accelerator, a filler, a plasticizer, a colorant, and a cure inhibitor. A process for forming a polymerized coating on an article involves the application of this formulation to the substrate of an article and allowing sufficient time for the solvent to evaporate to form the polymerized coating on the article. The substrate of the article forms a corrosion barrier even without prior removal of a native corrosion layer on a surface of the substrate of the article. | 2 |
FIELD OF THE INVENTION
The present invention is directed to pigment compositions, thick film black pigment compositions, conductive single layer thick film compositions, black electrodes made from such black conductive compositions and methods of forming such electrodes, more specifically the present invention is further directed to the use of such compositions, electrodes, and methods in flat panel display applications, including alternating-current plasma display panel devices (AC PDP).
BACKGROUND OF THE INVENTION
While the background of the present invention is discussed in terms of plasma display panel (PDP) applications, it is understood that the present invention is also useful in flat panel display applications, in general, as well as in black ceramic dielectrics.
The PDP typically comprises a pair of forward and backward insulation substrates arranged in opposition to each other to form a plurality of cells as display elements each defined by the insulation substrates supported with a constant interval and cell barriers arranged between the insulation substrates, two crossing electrodes disposed on internal surfaces of the insulation substrates with a dielectric layer interposed between the electrodes which cause electric discharge in a plurality of cells by application of an alternating current. Due to this application of alternating current, phosphor screens formed on the wall surface of the cell barrier emit light and display images which are passed through the transparent insulation substrate (typically called the front glass substrate or plate).
One area of concern for PDP manufacturers is display contrast, which affects the ultimate picture viewed by the consumer. To improve the display contrast, it is essential to decrease the reflection of external light from the electrodes and conductors arranged on the front glass substrate of the PDP device. This reflection decrease can be accomplished by making the electrodes and conductors black as viewed through the front plate of the display. The black pigments are used to improve cosmetics of applied circuitry by masking the circuit behind a layer of black enamel. In display applications, compositions containing black pigments are deposited in a way that enhances the contrast between the lighted pixels and the unlit areas of the display when the panel is being actively viewed.
Another area of concern for PDP manufacturers is of an environmental nature and is the lead and cadmium contained in some conventional black conductor compositions and black electrodes used in PDP devices. It is desirable to reduce and/or eliminate the lead and cadmium contained in the black conductor compositions and electrodes while still maintaining the required physical and electrical properties of the compositions and electrodes.
U.S. Pat. Nos. 5,851,732 and 6,075,319 to Kanda et al. disclose a photoformable black electrode comprising a conductive layer of at least one of RuO 2 , ruthenium based polynary oxide or mixtures thereof formed between the substrate and conductor electrode arrangement.
Bismuth ruthenium pyrochlore and lead bismuth ruthenium pyrochlore, and other chemical compounds, have been used as black pigments.
U.S. Patent Publication No. 2006-0231806 A1, discloses the use of bismuth glasses and bismuth ruthenium pyrochlore, copper bismuth ruthenium pyrochlore, and gadolinium bismuth pyrochlore as pigments, preferably with surface areas less than 20 m 2 /g.
Additionally, some prior art compositions have utilized “spinels” as pigment. Spinels, as used herein, are mineral oxides defined by the formula AB 2 O 4 , where A and B represent cations. While the ideal spinel formula is MgAl 2 O 4 , some 30 elements, with valences from 1 to 6, are known to substitute in the A or B cation sites, resulting in well over 150 synthetic compounds having the spinel crystal structure. Spinels have a pointed octahedral, crystal habit, and also form a dendritic snowflake form (i.e., a mineral crystallizing in another mineral in the form of a branching or treelike mark) in rapidly chilled high-temperature slags and lavas. The named spinel minerals that have so far been recorded in nature are oxides that occur as a matrix of A 2+ versus B 3+ cations.
Rangavittal N. et al., Eur. J. Solid State Inorg. Chem., v. 31, p. 409 (1994) have prepared and reported the cation distributions of several derivatives of the cubic oxide γ-Bi 2 O 3 , where the Bi atoms are replaced by any one of the following metals Co, Mn, Fe, Ti, Ni, or Pb. In particular, they showed that it was possible to prepare a wide range of compounds where a substantial portion of the bismuth could be replaced with cobalt.
The present inventors have developed novel pigment compositions that improve display contrast and avoid the above described environmental problems.
SUMMARY OF THE INVENTION
The present invention concerns a pigment composition of the formula
Bi 26-x-y Mn x Co y O 40-z
1. wherein the sum of x and y is between 7.8 and 20.8, and x or y is at least 1.3. In some embodiments the sum of x and y is between 13 and 20.8, where x or y is at least 2.6. In other embodiments the sum of x and y is between 15.6 and 20.8 and x or y is at least 5.
The invention further concerns s thick film black composition comprising:
(a) black pigment of the formula
Bi 26-x-y Mn x Co y O 40-z
wherein the sum of x and y is between 7.8 and 20.8, and x or y is at least 1.3; (b) one or more glass frits with a softening point in the range of 400° C. to 600° C.; (c) organic polymer binder; and (d) organic solvent.
The invention is further directed to AC PDP devices themselves. In some embodiments, the invention is directed to single layer bus (SLB) electrodes, their use in flat panel display applications, and the use of particular novel thick film compositions in the formation of such electrodes. Alternatively, in some other embodiments, the invention is directed to multilayer bus electrodes.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 details a trilinear contour plot the fitted quadratic model of L* color index in the bismuth oxide, manganese dioxide, and ferric oxide system.
FIG. 2 details a trilinear contour plot the fitted quadratic model of L* color index in the bismuth oxide, cobalt oxide, and ferric oxide system
FIG. 3 details a trilinear contour plot the fitted quadratic model of L* color index in the bismuth oxide, manganese dioxide, and cobalt oxide system.
FIG. 4 details a trilinear contour plot the fitted cubic model of L* color index in the bismuth oxide, manganese dioxide, and cobalt oxide system.
FIGS. 5 A,B show the x-ray diffraction pattern of a commercial copper chromite black spinel pigment compared with lines and intensities reported for copper chromite spinel.
FIGS. 6 A,B show the x-ray diffraction pattern of a commercial black cobalt oxide pigment compared with lines and intensities reported for cobalt oxide in the spinel structure.
FIGS. 7 A,B show the x-ray diffraction pattern of Example 17 compared with lines and intensities reported for a bismuth cobalt oxide of similar bismuth content in the γ-Bi 2 O 3 structure.
FIGS. 8 A,B show the x-ray diffraction pattern of the pigment from Example 17 contrasted to the pattern of a commercial copper chromite black spinel.
DETAILED DESCRIPTION OF THE INVENTION
A. Black Pigment(s)
The current invention discloses a novel family of black pigments based on Mn/Co substitutions for Bi in γ-Bi 2 O 3 .
The pigment(s) can generally be described by the formula
Bi 26-x-y Mn x Co y O 40-z
wherein the sum of x and y is between 7.8 and 20.8, and x or y is at least 1.3. Up to ⅓ of the total manganese and cobalt may be substituted by a variety of one or more other metals, for example Ni, Cu, Al, Ce, Pb, Ga, Mg, In, V, Li, P, Fe, Ti, Cr, Zn, Ge, Ni, Cd, Si, and other metals, especially in the +2, +3, or +4 valence state, and to a lesser degree in the +1 and +5 valence states.
Using established methods to prepare high surface area oxides, a series of mixed metal oxides have been prepared based on γ-bismuth oxide (Bi 26 O 40 ), where a portion of the bismuth is replaced by one or more metal ions. These pigments are easily prepared by mixing aqueous or acid solutions containing stoichiometric amounts of the appropriate metal nitrates, and then precipitating the pigment with the addition of excess 30% sodium hydroxide solution and 3% aqueous hydrogen peroxide. The precipitate is washed with de-ionized water to remove the soluble species (Na + , NO 3 − , and OH − ) and is then collected by filtration. After filtration, powder may be obtained by drying excess water from the filtrate by hot air drying, freeze drying, or spraying drying, or other applicable methods. The pigment powders prepared in this way have very high surface areas, often over 100 m2/g, and are amorphous to x-ray diffraction.
Alternatively, the pigments may be prepared by heating finely divided and well mixed constituent oxides in air at 600 C-1000 C for 16 hrs. Then subsequently regrinding the mixture and heating again to ensure complete reaction. As the amount of bismuth in the compounds decreases, it becomes increasing difficult to assure single phase products in this kind of high temperature reaction, as a small fraction of unreacted cobalt or manganese oxide, or their spinel persists even after multiple firings.
After preparing the compounds, the powders were characterized by measuring their x-ray diffraction patterns, determining semi-quantative elemental analysis with a Rigaku ZSX Mini 11 x-ray fluorescence spectrometer and measuring their color using a Minolta CR-300 calorimeter.
As seen in the FIGS. 5 A,B through 8 A,B the new pigments are not simply mixtures of previously known pigments in the spinel structure. FIGS. 5 A,B and 6 A,B show the x-ray diffraction patterns of commercially available black pigments in the spinel structure, together with the lines and intensities of the corresponding compound reported by the International Centre for Diffraction Data. In contrast, FIGS. 7 A,B show the x-ray pattern of the a new pigment described in Example 17. This pattern matches well with a Bi—Co oxide of similar bismuth content in the γ-Bi 2 O 3 structure. A visual contrast of the patterns in FIGS. 5 A,B and FIGS. 7 A,B is shown in FIGS. 8 A,B.
Many of the compounds prepared were yellow to brown in color, but surprisingly the combination of manganese and cobalt simultaneously substituted into the γ-bismuth oxide resulted in a fairly wide range of previously undisclosed black pigments with L* color below 15.
The remarkable and unexpected portion of this work is that the combination of the simultaneous substitution of cobalt and manganese in the γ-Bi 2 O 3 structure results in very dark brown to black pigments (L*=<4 to 10), while the substitution of either Co or Mn alone in the structure result in pigments which are significantly less dark (L*>10). Useful black pigments can be prepared by including additional metal substitutions for bismuth in γ-Bi 2 O 3 , as long as a significant portion of the substitution is the Mn/Co combination.
When the pigments are formed in thick film compositions, Items B and C below, and optionally further Items D, E, and F are incorporated to form the thick film composition. As used herein, the terms “thick film” and “thick film paste” refer to dispersions of finely divided solids in an organic medium, which are of paste consistency or tape castable slurry consistency and have a rheology suitable for screen printing and spray, dip, ink jet or roll-coating. As used herein, the term “thick film” means a suspension of powders in screen printing vehicles or tape castable slurry, which upon processing forms a film with a thickness of several microns or greater. The powders typically comprise functional phases, glass and other additives for adhesion to the substrate. The vehicles typically comprise organic resins, solvents and additives for rheological reasons. The organic media for such pastes are ordinarily comprised of liquid binder polymer and various rheological agents dissolved in a solvent, all of which are completely pyrolyzable during the firing process. Such pastes can be either resistive or conductive and, in some instances, may even be dielectric in nature. The thick film compositions of the present invention contain an inorganic binder as the functional solids are required to be sintered during firing. A more detailed discussion of suitable organic media materials can be found in U.S. Pat. No. 4,536,535 to Usala, herein incorporated by reference. Depending on the application, fired thick film layers are on the order of 0.5 to 300 microns for a single print or tape layer, and all ranges contained therein. In Ag and black 2-layer electrode PDP applications the fired thickness may be in the range of 0.5 to 10 microns; for dielectric layers in PDP applications, the thickness of the fired dielectric thick film layer may be in the range of 0.5 to 20 microns.
B. Glass Frits
The glass binder (glass frit) used in the present invention promotes the sintering of pigment and/or conductive component particles. The present invention, when formed into a thick film composition, may comprise one or more glass frits with a softening point in the range of 400° C.-600° C.
In one embodiment, the glass binder used in the present invention is a lead-free, low-melting glass binder. In a further embodiment, the glass binder is a lead-free and cadmium-free Bi based amorphous glass. Other lead-free, low-melting glasses are P based or Zn—B based compositions, which may be useful in the present composition. However, P based glass does not have good water resistance, and Zn—B glass is difficult to obtain in the amorphous state, hence Bi based glasses are preferred. Bi glass can be made to have a relatively low melting point without adding an alkali metal and has little problems in making a powder. In the present invention, Bi glass having the following characteristics is most preferred.
(I) Glass composition
55-85 wt % Bi 2 O 3 0-20 wt % SiO 2 0-5 wt % Al 2 O 3 2-20 wt % B 2 O 3 0-20 wt % ZnO 0-15 wt % one or more of oxides selected from BaO, CaO, and SrO (in the case of an oxide mixture, the maximum total is up to 15 wt %). 0-3 wt % one or more of oxides selected from Na 2 O, K 2 O, Cs 2 O and Li 2 O (in the case of an oxide mixture, the maximum total is up to 3 wt %).
(II) Softening point: 400-600° C.
In this specification, “softening point” means the softening point determined by differential thermal analysis (DTA). In the present invention, the glass binder composition and softening point are important characteristics for ensuring a good balance of all the properties of a black electrode are obtained. When the softening point is below 400° C., melting of the glass may occur while organic materials are decomposed, allowing blisters to occur in the composition. Therefore it is preferred that the softening point of the glass is >400° C. On the other hand, the glass must soften sufficiently at the firing temperature employed. For example, if a firing temperature of 550° C. is used, then the softening point should be 520° C., if the softening point exceeds 520° C. electrode peeling occurs at the corners and properties such as resistance, etc., are affected, compromising the balance of the electrode properties. If a higher firing temperature is used (depending on substrate) glass with softening point up to 600° C. can be used.
The glass binders used in the present invention preferably have a D 50 (i.e., the point at which ½ of the particles are smaller than and ½ are larger than the specified size) of 0.1-10 μm as measured by a Microtrac. More preferably, the glass binders have a D 50 of 0.5 to 1 μm. Usually, in an industrially desirable process, a glass binder is prepared by the mixing and melting of raw materials such as oxides, hydroxides, carbonates, etc., making into a cullet by quenching, mechanical pulverization (wet, dry), then drying in the case of wet pulverization. Thereafter, if needed, classification is carried out to the desired size. It is desirable for the glass binder used in the present invention to have an average particle diameter smaller than the thickness of the black conductive layer to be formed.
A combination of glasses with different softening point may be used in the present invention. High softening point glasses can be combined with low softening point glasses. The proportion of each different softening point glass is determined by the precise balance of the electrode properties required. Some portion of the glass binder may be comprised a glass(es) with a softening point above 600° C.
Based on the overall composition weight, the glass binder content should be 0.5 to 20 wt %. When the glass binder content is too small, bonding to the substrate is weak. In one embodiment, the glass binder is present in the range of 2 to 10 weight percent total black composition.
(C) Organic Matter
The compositions of the present invention may also comprise organic matter. Organic matter is present in the composition in the range of 25-59 wt %, based on total composition. The organic matter included in the present invention may comprise an organic polymer binder and organic medium, including solvent. The organic matter may further comprise photoinitiators, photocurable monomers, oligomers, or unsaturated organic polymers designed to allow the formation of patterns using actinic radiation. These are explained below.
(D) Organic Polymer Binders
The polymeric binders are important in the compositions of the present invention and should be selected considering the water-based developability and high resolution. Such requirements are satisfied by the following binders. Such binders may be copolymers and interpolymers (mixed polymers) made from (1) non-acidic comonomers such as C 1-10 alkyl acrylates, C 1-10 alkyl methacrylates, styrene, substituted styrene, or combinations thereof, and (2) acidic comonomers including an ethylenically unsaturated carboxylic acid in at least 15 wt % of the total polymer weight.
The presence of the acidic comonomers in the compositions is important in the technology of the present invention. With such an acidic functional group, development in an aqueous base such as a 0.4 wt % sodium carbonate aqueous solution is possible. If the acidic comonomer content is less than 15 wt %, the composition may not be washed off completely by the aqueous base. If the acidic comonomer content is above 30%, the composition has low stability under the development conditions and the image area is only partially developed. Suitable acidic comonomers may be ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, etc.; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, vinylsuccinic acid, maleic acid, etc., their half esters (hemiesters), as well as sometimes their anhydrides and mixtures. For clean burning under a low-oxygen atmosphere, methacrylic polymers are preferred over acrylic polymers.
When the non-acidic comonomers are alkyl acrylates or alkyl methacrylates described above, the non-acidic comonomer content in the polymeric binders should be at least 50 wt %, preferably 70-75 wt %. When the non-acidic comonomers are styrene or substituted styrene, the non-acidic comonomer content in the polymeric binder should be 50 wt %, with the remaining 50 wt % being an acid anhydride such as maleic anhydride hemiester. The preferred substituted styrene is α-methylstyrene.
While not preferred, the non-acidic portion of the polymeric binder may contain less than about 50 wt % of other non-acidic comonomers substituting the alkyl acrylate, alkyl methacrylate, styrene, or substituted styrene portion of the polymer. For example, they include acrylonitrile, vinyl acetate, and acrylamide. However, in such cases, complete combustion is more difficult, thus such a monomer content should be less than about 25 wt % of the overall polymeric binder weight. Binders may consist of a single copolymer or combinations of copolymers fulfilling various standards described above. In addition to the copolymers described above, other examples include polyolefins such as polyethylene, polypropylene, polybutylene, polyisobutylene, ethylene-propylene copolymer, etc., as well as polyethers such as lower alkylene oxide polymers including polyethylene oxide.
These polymers can be prepared by solution polymerization technology commonly used in the acrylic acid ester polymerization field.
Typically, the acidic acrylic acid ester polymers described above can be obtained by mixing an α- or β-ethylenically unsaturated acid (acidic comonomer) with one or more copolymerizable vinyl monomers (non-acidic comonomer) in an organic solvent having a relatively low boiling point (75-150° C.) to obtain a 10-60% monomer mixture solution, then adding a polymerization catalyst to the monomer, followed by polymerization. The resulting mixture is heated under ambient pressure at the reflux temperature of the solvent. After completion of the polymerization reaction, the resulting acidic polymer solution is cooled to room temperature. A sample is recovered and measured for the polymer viscosity, molecular weight, and acid equivalent.
The acid-containing polymeric binder described above should have a molecular weight below 50,000.
When such compositions are coated by screen printing, the polymeric binder should have a Tg (glass transition temperature) exceeding 60° C.
(E) Photoinitiators
Suitable photoinitiators are thermally inert but generate free radicals when exposed to actinic radiation at a temperature below 185° C. These photoinitiators are compounds having two intramolecular rings inside a conjugated carbon ring system and include (un)substituted polynuclear quinines, e.g., 9,10-anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, octamethylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, benz[a]anthracene-7,12-dione, 2,3-naphthacene-5,12-dione, 2-methyl-1,4-naphthoquinone, 1,4-dimethylanthraquinone, 2,3-dimethylanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, retenquinone[transliteration], 7,8,9,10-tetrahydronaphthacene-5,12-dione, and 1,2,3,4-tetrahydrobenz[a]anthracene-7,12-dione. Other useful photoinitiators are described in U.S. Pat. No. 2,760,863 [Of these, some are thermally active at a low temperature of 85° C., such as vicinal ketaldonyl alcohols, e.g., benzoin and pivaloin; acyloin ethers such as benzoin methyl or ethyl ether; α-methylbenzoin, α-allylbenzoin, α-phenylbenzoin, thioxanthone and its derivatives, hydrogen donors, hydrocarbon-substituted aromatic acyloin, etc.]
For initiators, photo-reducible dyes and reducing agents may be used. These are described in U.S. Pat. Nos. 2,850,445, 2,875,047, 3,097,096, 3,074,974, 3,097,097, and 3,145,104 and include phenazine, oxazine, quinones, e.g., Michler's ketone, ethyl Michler's ketone, and benzophenone, as well as hydrogen donors including leuco dyes-2,4,5-triphenylimidazolyl dimmer and their mixtures (U.S. Pat. Nos. 3,427,161, 3,479,185, and 3,549,367). The sensitizers described in U.S. Pat. No. 4,162,162 are useful with the photoinitiators and photoinhibitors. The photoinitiators and photoinitiator systems are present at 0.05-10 wt % based on the overall weight of the dry photopolymerizable layer.
(F) Photocurable Monomer
The photocurable monomer component used in the present invention has at least one polymerizable ethylene group and contains at least one addition-polymerizable ethylenically unsaturated compound.
These compounds initiate polymer formation by free radicals and undergo chain-extending addition polymerization. The monomeric compounds are not gaseous, i.e., having boiling point higher than 100° C., and have plasticizing effects on the organic polymeric binders.
Preferred monomers that can be used alone or in combination with other monomers include t-butyl(meth)acrylate, 1,5-pentanediol di(meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexamethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, decamethylene glycol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, 2,2-dimethylolpropane di(meth)acrylate, glycerol di(meth)acrylate, tripropylene glycol di(meth)acrylate, glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, compounds described in U.S. Pat. No. 3,380,381, 2,2-di(p-hydroxyphenyl)propane di(meth)acrylate, pentaerythritol tetra(meth)acrylate, triethylene glycol diacrylate, polyoxyethylene-1,2-di(p-hydroxyethyl)propane dimethacrylate, bisphenol A di[3-(meth)acryloyloxy-2-hydroxypropyl]ether, bisphenol A di[2-(meth)acryloyloxyethyl]ether, 1,4-butanediol di(3-methacryloyloxy-2-hydroxypropyl)ether, triethylene glycol dimethacrylate, polyoxyporpyltrimethylolpropane triacrylate, butylenes glycol di(meth)acrylate, 1,2,4-butanediol [sic]tri(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, 1-phenylethylene 1,2-dimethacrylate, diallyl fumarate, styrene, 1,4-benzenediol dimethacrylate, 1,4-diisopropenylbenzene, and 1,3,5-triisopropenylbenzene [(meth)acrylate means both acrylate and methacrylate].
Useful are ethylenically unsaturated compounds having molecular weights below 300, e.g., an alkylene or polyalkylene glycol diacrylate prepared from an alkylene glycol or polyalkylene glycol, such as a 1-10 ether bond-containing C 2-15 alkylene glycol, and those described in U.S. Pat. No. 2,927,022, such as those containing a terminal addition-polymerizable ethylene bond.
Other useful monomers are disclosed in U.S. Pat. No. 5,032,490, herein incorporated by reference.
Preferred monomers are polyoxyethylenated trimethylolpropane tri(meth)acrylate, ethylated pentaerythritol acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol monohydroxypentacrylate, and 1,10-decanediol dimethacrylate.
Other preferred monomers are monohydroxypolycaprolactone monoacrylate, polyethylene glycol diacrylate (molecular weight: about 200), and polyethylene glycol dimethacrylate (molecular weight: about 400). The unsaturated monomer component content is 1-20 wt % based on the overall weight of the dry photopolymerizable layer.
(G) Organic Medium
The organic medium is mainly used for the easy coating of dispersions containing a finely pulverized composition on ceramics and other substrates. Thus, first, the organic medium should be capable of dispersing the solid components in a stable manner and, second, the rheological property of the organic medium is to impart good coatability to the dispersion.
In the organic medium, the solvent component that may be a solvent mixture should be selected from those capable of complete dissolution of polymers and other organic components. The solvents are selected from those that are inert (not reactive) with respect to the paste composition components. Solvents are selected from those that have a sufficiently high volatility, thus evaporate well from the dispersion even when coated under ambient pressure at a relatively low temperature, while in the case of the printing process, the volatility should not be too high, causing rapid drying of the paste on the screen at room temperature. Solvents that can be favorably used in the paste compositions should have boiling point below 300° C. under ambient pressure, preferably below 250° C. Such solvents may be aliphatic alcohols or their esters such as acetic acid esters or propionic acid esters; terpenes such pine resin, α- or β-terpineol, or mixtures thereof; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol esters such as butyl Cellosolve acetate; butyl Carbitol and Carbitol esters such as butyl Carbitol acetate and Carbitol acetate; Texanol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), and other suitable solvents.
The compositions of the present invention may also contain additional components described below, in addition to the components described above.
(H) Additional Components
These are dispersants, stabilizers, plasticizers, releases, stripping agents, defoamers, wetting agents, etc., that are well known in the art. Common materials are disclosed in U.S. Pat. No. 5,032,490 herein incorporated by reference.
(I). Optional Conductive Metal Particles
Optional conductive metal particles are utilized in the formation of electrode layer compositions. The optional conductive metal particles may be selected from the group comprising gold, silver, platinum, palladium, copper, ruthenium dioxide, polanary oxides of ruthenium and mixtures thereof; may also be utilized in the invention.
Application of Pigments in Non-Photoimageable Thick Film Composition
Using these new pigments, thick film electronic compositions have been made using a standard ethyl cellulose medium and commercially available bismuth-containing oxide glasses. When these compositions are applied in a layer on a substrate and fired between 400 and 600 C, the resulting films are generally black in color, with L* between 4 and 10.
Modeling of L* Color Index in Composition Space
Pigment colors were explored in the bismuth oxide, ferric oxide, manganese dioxide system using a designed experiment. The mixture experiment included patent examples 1, 2, 5, 7, as well as bismuth oxide, manganese dioxide, and ferric oxide. L* color indices were fit to a quadratic mixture model using Minitab-14. The L* model, fit with a quadratic mixture model to an R 2 of 99% is shown plotted as a contour plot in FIG. 1 . The tri-linear axis, are shown as mole % metal in the oxides. For example, Bi 13 Mn 13 O 40 is can be plotted on the diagram as Bi, 0.5; Mn, 0.5; Fe, 0.0. The colors are largely represented by linear combinations of the L* indices component oxides (bismuth oxide, manganese dioxide, and ferric oxide). The color is darkest in the vicinity of manganese dioxide, less dark near ferric oxide and gradually approaches pale yellow near bismuth oxide.
FIG. 2 shows the corresponding tri-linear contour plots in the bismuth oxide, cobalt oxide, ferric oxide system. In this case the quadratic model for L* (fit with an R 2 of 99% to patent examples 2,3,4, and 6, as well as the corners represented by bismuth oxide, ferric oxide, and cobalt oxide) is quite similar to that shown in FIG. 1 . Again the L* color is lowest (darkest) near cobalt oxide, and gradually becomes larger (lighter) as the pigment composition moves toward ferric oxide and/or bismuth oxide.
In the case of the bismuth oxide, cobalt oxide, manganese dioxide system however we see a different and unexpected pattern. The quadratic mixture model fit (R 2 =86%) to the L* indices of patent examples 1, 3, 4, 8, 9, 12 thru 33, as well as the corner points represented by bismuth oxide, cobalt oxide, and manganese dioxide is shown in FIG. 3 . A large compositional area exits between 10 and 70 mol % bismuth where the combination of manganese, cobalt, and bismuth oxides combine to form dark pigments L*<20, where the darkness is largely independent of the manganese/cobalt ratio. The fit can be improved by including the full set of cubic terms in the mixture model. Shown in FIG. 4 , this model (R 2 =99%), the areas of lowest L* values in the center of the diagram are bounded by areas of higher L* when the manganese or cobalt content is reduced to below about 5 mol %. The area of lowest L* indices is in the center of the diagram roughly centered at 33 mol % cobalt and 33 mol % manganese (34 mole % bismuth).
EXAMPLES
X-ray diffraction scans of the oxide powders that were formed in the precipitations have been run, but they have invariably been amorphous powders. Consistent with this finding are SEM micrographs that show the inherent particle size of the powders to be about 30 nm in diameter. The surface area of these powders is very high, usually in excess of 100 m 2 /g. To confirm that these materials are in fact based on substituted γ-Bi 2 O 3 , a few examples were prepared using standard high temperature approaches. The x-ray diffraction pattern of Example 17, closely matches the pattern of Bi 10 Co 16 O 40 measured by Rangvitall, et al. and it's L* a* b* color indices closely match those of the precipitated compound of the same composition (Example 16). Similarly, the x-ray diffraction pattern of Example 25 matches well the pattern of Bi 10 Co 16 O 40 reported by Rangvitall. In the literature report, a small amount (5%) of unreacted CO 3 O 4 was persistent, and in our high temperature synthesis, a similarly small amount of manganese-cobalt spinel was observed. The L* indices are not quite as low for the high temperature material, but are still similar enough that we believe the substituted γ-Bi 2 O 3 is an appropriate assignment for the precipitated powder.
In a separate attempt to produce more crystalline powders from the precipitation reactions, a precipitated solid of composition Bi 13 Mn 6.5 Co 6.5 O 40 was prepared and was then left in the basic sodium nitrate solution, stirred and heated at 80 C for 5 days. The Ostwald-ripened powder was then filtered, washed, and air dried. The x-ray diffraction pattern of this powder was more crystalline, showing a series of broad diffraction peaks that corresponded well to the Bi 10 Co 16 O 40 pattern found by Rangivittal, et al. The L* color of this more crystalline powder matches closely the L* color of the amorphous powder made by directly filtering, washing, and drying the precipitate.
Because of the lack of definitive x-ray diffraction patterns, it is difficult to establish the lowest bismuth content where only substituted γ-Bi 2 O 3 forms in the Bi—Co—Mn oxide precipitates. But the mixture of what are believed to be Co—Mn spinels and the substituted γ-Bi 2 O 3 phases are nonetheless effective black pigments.
After precipitation, the surface area of the pigment powders is typically >100 m2/g. As is known in the art, such high surface area powders can be difficult to adequately disperse in organic medium. The powders may be calcined above 300° C. to sinter the particles and reduce the surface area. A typical profile for calcining pigment powders is 520 C for 3 hours, which reduces the original surface area to about 20 m2/g.
A summary of the example pigment compositions and colors prepared during this work is shown in Table 1. Table 2 lists a comparison of the theoretical metal content of the powders (total metal=100%) and the compositions as determined using the semiquantitative analytic method of x-ray fluorescence spectroscopy.
TABLE 1
Powder Compositions and Color Indices
CIELAB 1976 L* a* b* Color
nominal
Indices
composition
L*
a*
b*
Example 1
Bi 13 Mn 13 O 40
18.25
2.08
0.69
Example 2
Bi 13 Fe 13 O 40
33.08
11.84
12.84
Example 3
Bi 13 Co 13 O 40
16.05
1.43
0.31
Example 4
Bi 10 Co 16 O 40
24.93
2.11
1.14
Example 5
Bi 13 Mn 6.5 Fe 6.5 O 40
21.58
2.95
1.35
Example 6
Bi 8 Co 9 Fe 9 O 40
8.15
1.54
0.00
Example 7
Bi 8 Mn 9 Fe 9 O 40
10.37
1.62
0.29
Example 8
Bi 5.2 Co 20.8 O 40
11.02
1.37
−0.02
Example 9
Bi 5.2 Mn 20.8 O 40
10.12
1.39
−0.10
Example 10
Bi 11 Co 7.5 Cu 7.5 O 40
25.12
1.92
1.12
Example 11
Bi 11 Mn 7.5 Cu 7.5 O 40
20.40
2.29
0.80
Example 12
Bi 20.8 Mn 2.6 Co 2.6 O 40
30.64
1.59
1.73
Example 13
Bi 18.2 Mn 5.2 Co 2.6 O 40
14.80
1.45
0.31
Example 14
Bi 18.2 Mn 2.6 Co 5.2 O 40
13.00
1.40
0.09
Example 15
Bi 18.2 Mn 3.9 Co 3.9 O 40
15.57
1.51
0.34
Example 16
Bi 15.6 Mn 5.2 Co 5.2 O 40
5.44
0.56
−0.40
Example 17
Bi 15.6 Mn 5.2 Co 5.2 O 40
6.77
0.08
−0.93
Example 18
Bi 13 Mn 6.5 Co 6.5 O 40
4.52
0.48
−0.42
Example 19
Bi 13 Mn 6.5 Co 6.5 O 40
4.00
0.44
−0.42
Example 20
Bi 13 Mn 6.5 Co 6.5 O 40
3.81
0.42
−0.41
Example 21
Bi 13 Mn 9.75 Co 3.25 O 40
7.65
1.05
−0.29
Example 22
Bi 13 Mn 3.25 Co 9.75 O 40
7.12
0.91
−0.32
Example 23
Bi 13 Mn 6.5 Co 6.5 O 40
4.53
0.49
−0.41
Example 24
Bi 8.67 Mn 8.67 Co 8.67 O 40
4.44
0.47
−0.45
Example 25
Bi 8.67 Mn 8.67 Co 8.67 O 40
11.27
0.39
−0.91
Example 26
Bi 6.5 Mn 13 Co 6.5 O 40
4.39
0.53
−0.38
Example 27
Bi 6.5 Mn 6.5 Co 13 O 40
4.67
0.54
−0.39
Example 28
Bi 5.2 Mn 10.4 Co 10.4 O 40
4.38
0.57
−0.42
Example 29
Bi 5.2 Mn 18.2 Co 2.6 O 40
4.54
0.59
−0.37
Example 30
Bi 5.2 Mn 2.6 Co 18.2 O 40
6.68
0.97
0.37
Example 31
Bi 5.2 Mn 19.5 Co 1.3 O 40
5.94
0.90
−0.33
Example 32
Bi 5.2 Mn 1.3 Co 19.5 O 40
7.97
1.05
−0.26
Example 33
Bi 2.6 Mn 11.7 Co 11.7 O 40
4.42
0.52
−0.40
Example 34
Bi 11 Mn 5 Co 5 Al 5 O 40
5.13
0.33
−0.41
Example 35
Bi 11 Mn 5 Co 5 Ce 5 O 40
11.30
1.37
−0.04
Example 36
Bi 11 Mn 5 Co 5 Cu 5 O 40
4.54
0.39
−0.27
Example 37
Bi 11 Mn 5 Co 5 Ni 5 O 40
4.49
0.48
−0.48
Example 38
Bi 11 Mn 5 Co 5 Fe 5 O 40
4.97
0.43
−0.35
Example 39
Bi 11 Mn 5 Co 5 Nd 5 O 40
5.10
0.18
−0.41
TABLE 2
X-ray Fluorescence Semi-quantitative Analysis of Examples
Calculated and Actual Metal Content (100% Metal basis)
Bi
Co
Mn
Other
nominal composition
calc
act
calc
act
calc
act
Metal
calc
act
Example 1
Bi 13 Mn 13 O 40
79.2
81.4
20.8
18.6
Example 2
Bi 13 Fe 13 O 40
78.9
81.6
Fe
21.1
18.4
Example 3
Bi 13 Co 13 O 40
78.0
79.8
22.0
20.2
Example 4
Bi 10 Co 16 O 40
68.9
72.8
31.1
27.2
Example 5
Bi 13 Mn 6.5 Fe 6.5 O 40
79.1
81.3
10.4
9.6
Fe
10.6
9.1
Example 6
Bi 8 Co 9 Fe 9 O 40
61.8
59.6
19.6
21.1
Fe
18.6
19.2
Example 7
Bi 8 Mn 9 Fe 9 O 40
62.6
63.5
18.8
15.9
Fe
18.5
20.6
Example 8
Bi 5.2 Co 20.8 O 40
47.0
50.0
53.0
50.0
Example 9
Bi 5.2 Mn 20.8 O 40
48.7
50.8
51.3
49.1
Example 10
Bi 11 Co 7.5 Cu 7.5 O 40
71.5
73.5
13.7
13.1
Cu
14.8
13.4
Example 11
Bi 11 Mn 7.5 Cu 7.5 O 40
72.1
73.6
12.9
12.8
Cu
15.0
13.6
Example 12
Bi 20.8 Mn 2.6 Co 2.6 O 40
93.6
94.8
3.3
2.7
3.1
2.5
Example 13
Bi 18.2 Mn 5.2 Co 2.6 O 40
89.7
90.7
3.6
3.2
6.7
6.1
Example 14
Bi 18.2 Mn 2.6 Co 5.2 O 40
89.4
90.2
7.2
6.3
3.4
3.5
Example 15
Bi 18.2 Mn 3.9 Co 3.9 O 40
89.5
90.3
5.4
4.9
5.0
4.8
Example 16
Bi 15.6 Mn 5.2 Co 5.2 O 40
84.6
85.8
8.0
7.3
7.4
6.9
Example 17
Bi 15.6 Mn 5.2 Co 5.2 O 40
84.6
79.2
8.0
10.2
7.4
10.6
Example 18
Bi 13 Mn 6.5 Co 6.5 O 40
78.6
11.1
10.3
Example 19
Bi 13 Mn 6.5 Co 6.5 O 40
78.6
11.1
10.3
Example 20
Bi 13 Mn 6.5 Co 6.5 O 40
78.6
11.1
10.3
Example 21
Bi 13 Mn 9.75 Co 3.25 O 40
78.9
80.1
5.6
5.3
15.6
14.6
Example 22
Bi 13 Mn 3.25 Co 9.75 O 40
78.3
79.5
16.6
15.4
5.2
5.0
Example 23
Bi 13 Mn 6.5 Co 6.5 O 40
78.6
79.7
11.1
10.2
10.3
10.0
Example 24
Bi 8.67 Mn 8.67 Co 8.67 O 40
64.7
66.7
18.3
16.5
17.0
16.7
Example 25
Bi 8.67 Mn 8.67 Co 8.67 O 40
64.7
64.9
18.3
16.9
17.0
18.1
Example 26
Bi 6.5 Mn 13 Co 6.5 O 40
55.3
56.0
15.6
15.0
29.1
29.0
Example 27
Bi 6.5 Mn 6.5 Co 13 O 40
54.7
56.8
30.9
29.3
14.4
13.9
Example 28
Bi 5.2 Mn 10.4 Co 10.4 O 40
47.9
52.8
27.0
25.7
25.2
21.8
Example 29
Bi 5.2 Mn 18.2 Co 2.6 O 40
47.2
49.9
6.2
6.6
46.6
43.4
Example 30
Bi 5.2 Mn 2.6 Co 18.2 O 40
48.5
49.4
6.8
6.6
44.6
44.0
Example 31
Bi 5.2 Mn 19.5 Co 1.3 O 40
48.6
52.5
3.4
3.1
47.9
44.4
Example 32
Bi 5.2 Mn 1.3 Co 19.5 O 40
47.1
49.0
49.8
47.6
3.1
3.4
Example 33
Bi 2.6 Mn 11.7 Co 11.7 O 40
29.0
33.8
36.8
34.8
34.3
31.4
Example 34
Bi 11 Mn 5 Co 5 Al 5 O 40
76.6
79.9
9.8
9.1
9.2
9.7
Al
4.5
1.2
Example 35
Bi 11 Mn 5 Co 5 Ce 5 O 40
64.4
68.4
8.3
7.5
7.7
7.6
Ce
19.6
16.6
Example 36
Bi 11 Mn 5 Co 5 Cu 5 O 40
72.2
74.2
9.3
7.9
8.6
9.6
Cu
10.0
8.2
Example 37
Bi 11 Mn 5 Co 5 Ni 5 O 40
72.7
75.5
9.3
7.7
8.7
8.5
Ni
9.3
8.3
Example 38
Bi 11 Mn 5 Co 5 Fe 5 O 40
73.0
76.9
9.4
5.9
8.7
9.1
Fe
8.9
8.1
Example 39
Bi 11 Mn 5 Co 5 Nd 5 O 40
64.0
66.4
8.2
7.0
7.7
7.3
Nd
20.1
19.3
It is evident from the literature that the γ-bismuth oxide structure is amenable to substitution by a wide range of metal ions. So it would not be surprising that similar metal ions could be substituted into the Co/Mn-containing bismuth oxide pigments described here.
Several compounds described in Examples 34 through 39 were prepared where about ⅓ of the Co—Mn content was replaced with other metals known to substitute in the γ-bismuth oxide structure. Each of these examples produced a relatively dark pigment with L* indices ranging from 4 to 11. These examples can be contrasted with Examples 5, 10, and 11, where at an approximately comparable Bi level, the pigments are much less dark in the absence of the combination of Mn and Co.
To demonstrate the utility of the new black pigments a series of compositions were prepared incorporating the black pigment into an electronic composition with bismuth borosilicate glasses, dispersed in an ethyl cellulose-based medium. The preparation of these compositions, are described in Examples 40 thru 43. After completely dispersing the pigments and frits into the organic vehicle, test parts were prepared and fired as described. After firing, L* a* b* color indices on each individual part was measured through the glass slide on the glass/pigmented composition interface. A summary of the results is listed in Table 3. At 400 C, all parts are noticeably gray because of the lack of frit sintering and wetting of the pigment. As the firing temperature increases, most compositions, notably Example 41 and 42 become darker in color as shown by the lower L* indices. Example 40 with the highest Bi content reaches it's darkest color at 450 C, and then gradually lightens, perhaps because of decomposition or solubility of the pigment into the Bi glasses. Example 43, which has the lowest Bi content in the pigment appears to inhibit sintering at low firing temperatures but is nearly as dark as the Examples 42 and 43 at 600 C.
TABLE 3
Example 40-43 Color indices vs firing temperature
Example 40
Example 41
Example 42
Example 43
400 C.
L*
27.1
30.7
24.4
25.1
a*
0.42
0.55
0.72
0.99
b*
−0.23
0.01
−0.1
0.14
450 C.
L*
5.1
5.6
6.4
15.3
a*
0.33
0.38
0.45
0.70
b*
−0.6
−0.61
−0.58
−0.27
500 C.
L*
5.3
5.4
5.1
10.9
a*
0.35
0.46
0.33
0.60
b*
−0.68
−0.67
−0.68
−0.46
550 C.
L*
7.7
4.8
4.9
6.1
a*
1.15
0.51
0.32
0.32
b*
−0.49
−0.50
−0.51
−0.60
600 C.
L*
21.4
5.3
4.4
5.3
a*
3.04
0.64
0.37
0.25
b*
0.84
−0.51
−0.46
−0.54
Example 45 shows the use of a new black pigment composition in a photosensitive black paste designed to be used in conjunction with a paste containing silver powder as described by Kanda, et al. The paste was prepared by dispersing the inorganic frit and pigment into an organic vehicle described by Kanda. The composition was then screen printed onto a glass slide and dried. Subsequently a layer of photoimageable silver conducts was printed over the black layer and dried. Then the two layers were exposed at 400-800 mJ using a UV exposure units and developed in 1% sodium carbonate solution at 85 F for about 15 sec. The resulting patterned conductor was subsequently fired forming a conductive network with sintered Ag over an opaque black layer, useful in display manufacture, per Kanda, et al.
Examples 46 shows, that the precipitated and dried pigment powder can be calcined to reduce its surface area.
Examples 47 shows that the blackness of the resultant fired film is dependent on the surface area of the calcined pigment powder, especially when the fired film is thin. Darker color is observed with surface areas below 20 m 2 /g.
Example 1
In a 2 liter Erlenmeyer flask, 37.9 grams of bismuth nitrate pentahydrate and 8.98 grams of manganese carbonate were dissolved in 55 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 177 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 2
In a 2 liter Erlenmeyer flask, 37.8 grams of bismuth nitrate pentahydrate and 31.47 grams of ferric nitrate nonahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 74 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 3
In a 2 liter Erlenmeyer flask, 37.44 grams of bismuth nitrate pentahydrate and 22.46 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 175 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 4
In a 2 liter Erlenmeyer flask 19.28 grams of bismuth nitrate pentahydrate, and 18.51 grams of cobalt (ii) nitrate hexahydrate were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 57 ml of 30% sodium hydroxide solution and 144 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 5
In a 2 liter Erlenmeyer flask, 37.9 grams of bismuth nitrate pentahydrate, 15.76 grams of ferric nitrate nonahydrate and 4.49 grams of manganese carbonate were dissolved in 53 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 88 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 6
In a 2 liter Erlenmeyer flask, 23.20 grams of bismuth nitrate pentahydrate, 21.73 grams of ferric nitrate nonahydrate and 15.66 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 91 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting dark brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 7
In a 2 liter Erlenmeyer flask, 23.46 grams of bismuth nitrate pentahydrate, 21.97 grams of ferric nitrate nonahydrate and 18.91 grams of 51% manganous nitrate solution were dissolved in 40 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 123 ml of 30% sodium hydroxide solution and 91 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting dark brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 8
In a 1 liter Erlenmeyer flask, 10.68 grams of bismuth nitrate pentahydrate and 25.63 grams of cobalt (ii) nitrate hexahydrate were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 57 ml of 30% sodium hydroxide solution and 200 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 9
In a 1 liter Erlenmeyer flask, 10.99 grams of bismuth nitrate pentahydrate and 33.43 grams of 51% manganous nitrate solution were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 57 ml of 30% sodium hydroxide solution and 200 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 10
In a 1 liter Erlenmeyer flask, 27.67 grams of bismuth nitrate pentahydrate, and 11.32 grams of cobalt (ii) nitrate hexahydrate, and 9.04 grams of copper (ii) nitrate hydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 88 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 11
In a 1 liter Erlenmeyer flask, 27.88 grams of bismuth nitrate pentahydrate, and 13.63 grams of 51% manganous nitrate solution, and 9.12 grams of copper (ii) nitrate hydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next 114 ml of 30% sodium hydroxide solution and 86 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 12
In a 2 liter Erlenmeyer flask, 51.12 grams of bismuth nitrate pentahydrate 4.58 grams of 51% manganous nitrate solution and 3.83 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 114 ml of 30% sodium hydroxide solution and 60 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting brown precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 13
In a 1 liter Erlenmeyer flask, 36.16 grams of bismuth nitrate pentahydrate 7.41 grams of 51% manganous nitrate solution, and 3.10 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 72 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 14
In a 1 liter Erlenmeyer flask, 36.09 grams of bismuth nitrate pentahydrate 3.70 grams of 51% manganous nitrate solution, and 6.19 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 72 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 15
In a 1 liter Erlenmeyer flask, 36.13 grams of bismuth nitrate pentahydrate 5.55 grams of 51% manganous nitrate solution, and 4.64 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 72 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 16
In a 2 liter Erlenmeyer flask, 42.66 grams of bismuth nitrate pentahydrate 10.19 grams of 51% manganous nitrate solution and 8.53 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 114 ml of 30% sodium hydroxide solution and 133 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 17
47.17 grams of bismuth (iii) oxide, 5.42 grams of cobalt oxide (CO 3 O 4 ) and 7.76 grams of manganese carbonate were ground together with a mortar and pestle. The resulting mixture was placed in an alumina crucible and fired at 775 C for 20 hours twice, regrinding the powders between firings.
Example 18
In a 2 liter Erlenmeyer flask, 37.67 grams of bismuth nitrate pentahydrate, 4.46 grams of manganese carbonate and 11.30 grams of cobalt (ii) nitrate hexahydrate were dissolved in 52 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 176 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 19
In a 500 ml volumetric flask, 75.34 grams of bismuth nitrate pentahydrate 27.00 grams of 51% manganous nitrate solution and 22.60 grams of cobalt (ii) nitrate hexahydrate were dissolved in 100 ml of 70% nitric acid and 200 ml of de-ionized water. Then the solution was brought to a total of 500 ml with de-ionized water. In a separate 500 ml volumetric flask, 352 ml of 3% aqueous hydrogen peroxide was diluted to 500 ml with de-ionized water. Using a peristolic pump, the two solutions were mixed together using a Y-shaped connector and discharged over a period of about 10 minutes into a stainless steel beaker containing 280 ml of 30% sodium hydroxide solution that was being vigorously stirred. After the solution has been fully discharged into the beaker, it was stirred for a further 1 hour. The resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a stainless steel tray and frozen. The frozen precipitate was then freeze dried using a commercial freeze dryer.
Example 20
In a 2 liter Erlenmeyer flask, 37.67 grams of bismuth nitrate pentahydrate 14.78 grams of 51% manganous nitrate solution and 11.30 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 140 ml of 30% sodium hydroxide solution and 176 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a stainless steel tray and frozen. The frozen precipitate was then freeze dried using a commercial freeze dryer.
Example 21
In a 2 liter Erlenmeyer flask, 37.79 grams of bismuth nitrate pentahydrate 6.72 grams of manganese carbonate and 5.67 grams of cobalt (ii) nitrate hexahydrate were dissolved in 54 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 123 ml of 30% sodium hydroxide solution and 177 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 22
In a 2 liter Erlenmeyer flask, 37.55 grams of bismuth nitrate pentahydrate 2.22 grams of manganese carbonate and 16.90 grams of cobalt (ii) nitrate hexahydrate were dissolved in 51 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 120 ml of 30% sodium hydroxide solution and 175 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 23
In a 2 liter Erlenmeyer flask, 37.67 grams of bismuth nitrate pentahydrate 14.78 grams of 51% manganous nitrate solution and 11.30 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 140 ml of 30% sodium hydroxide solution and 176 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 24
In a 2 liter Erlenmeyer flask, 27.89 grams of bismuth nitrate pentahydrate 19.99 grams of 51% manganous nitrate solution and 16.73 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 261 ml of 30% sodium hydroxide solution and 114 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 25
54.12 grams of bismuth (iii) oxide, 18.93 grams of cobalt oxide (CO 3 O 4 ) and 26.70 grams of manganese carbonate were ground together with a mortar and pestle. The resulting mixture was placed in an alumina crucible and fired at 750 C for 20 hours twice, regrinding the powders between firings.
Example 26
In a 2 liter Erlenmeyer flask, 24.76 grams of bismuth nitrate pentahydrate 35.50 grams of 51% manganous nitrate solution and 14.85 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 114 ml of 30% sodium hydroxide solution and 347 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 27
In a 2 liter Erlenmeyer flask, 24.56 grams of bismuth nitrate pentahydrate 17.60 grams of 51% manganous nitrate solution and 29.47 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 114 ml of 30% sodium hydroxide solution and 344 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example. 28
In a 1 liter Erlenmeyer flask, 17.33 grams of bismuth nitrate pentahydrate, 24.85 grams of 51% manganous nitrate solution, and 20.80 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 327 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example. 29
In a 1 liter Erlenmeyer flask, 17.52 grams of bismuth nitrate pentahydrate 43.95 grams of 51% manganous nitrate solution, and 5.26 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 327 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example. 30
In a 1 liter Erlenmeyer flask, 17.15 grams of bismuth nitrate pentahydrate 6.15 grams of 51% manganous nitrate solution, and 36.01 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 327 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 31
In a 1 liter Erlenmeyer flask, 10.97 grams of bismuth nitrate pentahydrate 29.48 grams of 51% manganous nitrate solution, and 1.65 grams of cobalt (ii) nitrate hexahydrate were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 57 ml of 30% sodium hydroxide solution and 200 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 32
In a 1 liter Erlenmeyer flask, 10.70 grams of bismuth nitrate pentahydrate 1.92 grams of 51% manganous nitrate solution, and 24.07 grams of cobalt (ii) nitrate hexahydrate were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 57 ml of 30% sodium hydroxide solution and 200 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 33
In a 2 liter Erlenmeyer flask, 15.6 grams of bismuth nitrate pentahydrate 50.32 grams of 51% manganous nitrate solution and 42.12 grams of cobalt (ii) nitrate hexahydrate were dissolved in 50 ml of 70% nitric acid and 200 ml of de-ionized water. Next, 114 ml of 30% sodium hydroxide solution and 656 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 34
In a 1 liter Erlenmeyer flask, 29.29 grams of bismuth nitrate pentahydrate 9.54 grams of 51% manganous nitrate solution, 10.3 grams of aluminum nitrate nonahydrate, and 7.99 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 124 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 35
In a 1 liter Erlenmeyer flask, 25.36 grams of bismuth nitrate pentahydrate 8.26 grams of 51% manganous nitrate solution, 10.32 grams of cerium (iii) nitrate hexahydrate and 6.91 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 108 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 36
In a 1 liter Erlenmeyer flask, 20.22 grams of bismuth nitrate pentahydrate 6.59 grams of 51% manganous nitrate solution, 4.41 grams of cupric nitrate 2.5 hydrate, and 5.52 grams of cobalt (ii) nitrate hexahydrate were dissolved in 25 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 60 ml of 30% sodium hydroxide solution and 86 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 37
In a 1 liter Erlenmeyer flask, 28.07 grams of bismuth nitrate pentahydrate 9.15 grams of 51% manganous nitrate solution, 7.65 grams of nickel (ii), and 5.52 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 119 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 38
In a 1 liter Erlenmeyer flask, 28.18 grams of bismuth nitrate pentahydrate 9.18 grams of 51% manganous nitrate solution, 10.66 grams of ferric nitrate nonahydrate, and 7.66 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 91 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 39
In a 1 liter Erlenmeyer flask, 25.23 grams of bismuth nitrate pentahydrate, 8.22 grams of 51% manganous nitrate solution, 8.53 grams of neodymium acetate hydrate and 6.88 grams of cobalt (ii) nitrate hexahydrate were dissolved in 40 ml of 70% nitric acid and 100 ml of de-ionized water. Next, 91 ml of 30% sodium hydroxide solution and 107 ml of 3% aqueous hydrogen peroxide were simultaneously added to the solution as it was being actively stirred. The mixture was stirred for about 1 hr. Then the resulting black precipitate was filtered through a 15 cm diameter Whatman GF/B filter disk mounted in a Buchner funnel. The precipitate was washed with 10 aliquots of 100 ml of de-ionized water, then removed to a Pyrex® glass dish and dried at 90 C for 8 hrs.
Example 40
16 grams of an ethyl cellulose medium, 0.8 grams of soya lethicin, 5.6 grams of (R3838), 8.4 grams of (R3899) and 5.20 grams of the black pigment from Example 16 were mixed, and then dispersed on a 3-roll mill. A 20 um wet film of the composition was doctor bladed onto a series of glass slides. The wet film was dried for 10 minutes in a 150 C oven. Then individual glass slides were fired for 15 minutes at one of the following temperatures: 400, 450, 500, 550, and 600 C.
Example 41
16 grams of an ethyl cellulose medium, 0.8 grams of soya lethicin, 5.6 grams of (R3838), 8.4 grams of (R3899) and 5.20 grams of the black pigment from Example 8 were mixed, and then dispersed on a 3-roll mill. A 20 um wet film of the composition was doctor bladed onto a series of glass slides. The wet film was dried for 10 minutes in a 150 C oven. Then individual glass slides were fired for 15 minutes at one of the following temperatures: 400, 450, 500, 550, and 600 C.
Example 42
16 grams of an ethyl cellulose medium, 0.8 grams of soya lethicin, 5.6 grams of (R3838), 8.4 grams of (R3899) and 5.20 grams of the black pigment from Example 11 were mixed, and then dispersed on a 3-roll mill. A 20 um wet film of the composition was doctor bladed onto a series of glass slides. The wet film was dried for 10 minutes in a 150 C oven. Then individual glass slides were fired for 15 minutes at one of the following temperatures: 400, 450, 500, 550, and 600 C.
Example 43
16 grams of an ethyl cellulose medium, 0.8 grams of soya lethicin, 5.6 grams of (R3838), 8.4 grams of (R3899) and 5.20 grams of the black pigment from Example 14 were mixed, and then dispersed on a 3-roll mill. A 20 um wet film of the composition was doctor bladed onto a series of glass slides. The wet film was dried for 10 minutes in a 150 C oven. Then individual glass slides were fired for 15 minutes at one of the following temperatures: 400, 450, 500, 550, and 600 C.
Example 44
A photoimageable composition of the kind described by Kanda was prepared by mixing 33% of a vehicle (34.8% of a Copolymer of 75% methylmethacrylate and 25% methacrylic acid, Mw.about.=7000, Tg=120.degree. C., Acid No.=164; 46.6% 2,2,4 Trimethylpentanediol-1,3 monoisobutyrate; 1.5% PVP/VA S-630, ISP Corp; 8.8% Diethyl thioxanthone; 8.2% Ethyl 4-(dimethylamino)benzoate; 0.06% 1,4,4-Trimethyl-2,3-diazabicyclo[3.2.2]-non-2-ene-N,N′-dioxide), 8.0% Trimethylolpropane ethoxy triacrylate monomer, 1% malonic acid, 0.2% butylated hydroxytoluene, 6.8% 2,2,4 Trimethylpentanediol-1,3 monoisobutyrate, 27% Glass Powder BT328—Nihon Yamamura Glass, 8% Glass powder BT2602-5—Nihon Yamamura Glass, and 16% of the pigment from Example 24. The composition was dispersed using a 3-roll mill. The composition was susbsequented screen printed to a dried thickness of 4 um on glass slides, and dried in a box oven for 15 minutes at 100 C. Additionally, some of the parts were overprinted using DuPont DC204 Fodel® Ag Conductor with a dried thickness of about 10 um and dried in a box oven for 15 minutes at 100 C. The parts, either single layer or two layer structure, were then exposed through a phototool with a collimated UV exposure source. The exposed parts were developed using a conveyorized spray processor containing 1% by weight sodium carbonate in water as the developer solution. The developer temperature was maintained at .about.30.degree. C., and the developer solution was sprayed at 10-20 psi. The developed parts were dried by blowing off the excess water, after development, with a forced air stream. The dried parts were then normally fired in air using a 90 minute profile with a peak temperature of 580 C for 10 minutes. Parts were microscopically examined to show that developed lines about 40 microns wide were cleanly patterned. Subsequently, the color of the black layer from the back side of the glass slide were measured using a Minolta CR-300 colorimeter calibrated with multiple standards. The L* index of the single layer black parts was 20.0 and the L* index of the black/DC204 parts was 6.3. When the when the black composition was printed at 6 um dried thickness and processed in the same conditions, the L* index for both the black parts and the black/DC204 parts was 5.1.
Example 45
700 grams of concentrated nitric acid was added to 2 liters of de-ionized water. Then 611.1 grams of bismuth nitrate pentahydrate, 465.4 grams of 51% manganous nitrate solution, and 367.1 grams of cobalt (ii) nitrate hexahydrate were added to the acid solution and were stirred until dissolved. The solution was diluted to 5 liters with additional de-ionized water and labeled Solution A. Solution B was prepared by diluting 500 ml of 35% aqueous hydrogen peroxide with 4.5 liters of de-ionized water. The two solutions were pumped at rate of 180 ml/minute using a 2-channel peristolic pump through two channels of a Y-shaped connector and allowed to mix as it flowed through a 25 cm length of ½ tubing attached to the remaining channel of the Y-connector. The mixture was then allowed to drip into 2.4 kg of 30% sodium hydroxide solution which was actively being stirred. A black precipitate immediately formed. On conclusion of the reaction, the warm solution was allowed to stirred for an additional hour, before being transferred to a filter. The precipitate was filtered to remove most of the filtrate and was then washed with several 1 liter aliquots of de-ionized water which were consecutively removed by further filtering. The washed precipitate was then transferred to stainless steel trays, frozen, and freeze-dried using a commercially available unit. The surface area of the freeze dried powder was about 100 m2/g.
Example 46
Four 100 g samples from the powder of Example 46 were subsequently placed in an alumina crucible and calcined in a box oven at various conditions to achieve lower surface area shown in Table 4 below.
TABLE 4
Time
Temperature
Surface Area
(hours)
(C.)
m 2 /g
3
470
41.1
3
520
24.0
3
570
15.2
5
600
8.3
Example 47
Photoimageable pastes with the composition of Example 46 were prepared using the pigments in Example 46. The resulting parts were processed using the same conditions of Example 45. The L* indices of the parts were measured using a calibrated Minolta CR-300 calorimeter. The results are tabulated below in Table 5.
TABLE 5
Pigment Surface Area (m 2 /g)
8.3
15.2
24.0
41.1
Black layer thickness of 4 um dried
L* of Black
4.5
4.8
9.8
24.3
alone
L* of Black + DC204
5.0
5.7
6.9
9.7
Black layer thickness of 6 um dried
L* of Black
4.6
4.7
4.6
12.0
alone | The present invention is directed to pigment compositions, thick film black pigment compositions, conductive single layer thick film compositions, black electrodes made from such black conductive compositions and methods of forming such electrodes, and to the uses of such compositions, electrodes, and methods in flat panel display applications, including alternating-current plasma display panel devices (AC PDP). | 2 |
BACKGROUND
[0001] Immunosuppressive drugs are commonly used in transplantation and in treatment of autoimmune diseases. Production of these drugs is expensive, and the most frequently used of these drugs, namely cyclosporine A, tacrolimus and rapamycin, exhibit undesirable side-effects. The search for new immunosuppressive drugs devoid of side-effects, particularly in the class of natural peptide immunoregulators and their analogues, represents a serious challenge for medicinal chemistry.
[0002] Cyclolinopeptide A (CLA), a very hydrophobic cyclic nonapeptide, was first isolated from linen seeds in 1959. CLA is strongly immunosuppressive, with a potency comparable to that of cyclosporine A (CsA). The mechanism of action of CLA was shown to be similar to that of CsA, i.e. CLA formed a complex with cyclophilin A causing inactivation of calcineurin, albeit at much lower affinity (Gaymes et al., Febs Lett, 1997, 418, 224-227). CLA inhibited both humoral and cellular immune response and graft-versus-host reaction; prolonged survival of allogeneic skin grafts; tempered post-adjuvant polyarthritis in rats and hemolytic anemia of New Zealand Black mice; and, similarly to CsA, inhibited IL1 and IL-2 production. Unfortunately, the high hydrophobicity of CLA presents an obstacle for the potential application of the compound in therapy.
[0003] Linear CLA analogues containing alanine residue in successive positions of the peptide chain were found to be immunosuppressive (Wieczorek et al., Arch Immunol Ther Exp, 1992, 40, 213-216). It was also found that the activity of linear CLA analogues gradually decreased with shortening of the peptide chain from the N-terminus, at the same time showing an increase of activity for C-terminal tetra- and tripeptides (Siemion et al., Arch Immunol Ther Exp, 1994, 42, 459-465). The introduction of a single, hydrophilic threonine residue into the CLA molecule did not result in improved solubility in water. However, an improvement in solubility was achieved by the introduction of a sulphonic group in the para-position of the phenyl ring of one or two phenyloalanine residues, without loss of biological activity (Siemion et al., Arch Immunol Ther Exp, 1992, 40, 257-261; Cebrat et al., J Peptide Res., 1997, 49, 415-420). In addition, it has been observed that the inclusion of tetrapeptidic (Pro-Pro-Phe-Phe) or tripeptidic (Pro-Phe-Phe) fragments in longer linear peptides chains seem to have significance for immunosuppressive activity (Wieczorek et al., Arch Immunol Ther Exp, 1993, 41, 291-296; Cebrat et al., Pol. J Chem, 1997, 71, 1401).
[0004] A series of analogues in which the cis-peptide bond between proline residues was replaced with 1,5-disubstituted tetrazole ring (a good mimetic of amide bonds in cis configuration) showed immunosuppressive activity comparable to CsA. (Karczmarek et al., Biopolymers, 2002, 63, 343-357).
[0005] Synthetic CLA analogues in which leucine residues in position 5 and/or 8 were replaced with their hydroxymethyl analogue displayed a four-fold increase in solubility in water in comparison to CLA, but also showed a 25% diminution in biological activity compared to native CLA (Zubrzak et al., Biopolymers (Peptide Science), 2005, 80, 347-356).
[0006] A series of nine CLA analogues was obtained by replacement of CLA proline residues with β 2 -isoproline and β 3 -homoproline. In comparison to CsA, these CLA analogues displayed strong inhibitory properties in the cellular immune response. The majority of these analogs were practically devoid of cell toxicity (Katarzyńska et al., J Pept Sci, 2009, 14, 1283-1294).
BRIEF DESCRIPTION OF THE INVENTION
[0007] There are provided in accordance with an embodiment of the present invention compounds having the formula I:
[0000]
[0000] wherein
[0008] k, m, n and p are each independently 0, 1 or 2;
[0009] R and R′ are each independently selected from H and C 1-3 alkyl, or, when taken together, R and R′ are —CR 1 R 1′ —X—CH 2 —, wherein CR 1 R 1′ is attached to the backbone nitrogen, R 1 and R 1′ are each independently selected from H and C 1-3 alkyl, and X is selected from —CH 2 —, —CH 2 CH 2 —, —CH(OH)—, —O—, —S— and —NH—;
[0010] R″ and R′″ are each independently selected from H and C 1-3 alkyl, or, when taken together, R″ and R′″ are —CR 2 R 2′ —X′—CH 2 —, wherein CR 2 R 2′ is attached to the backbone nitrogen, R 2 and R 2′ are each independently selected from H and C 1-3 alkyl, and X′ is selected from —CH 2 —, —CH 2 CH 2 —, —CH(OH)—, —O—, —S— and —NH—; and
[0011] R 3 and R 4 are each independently selected from aryl, substituted aryl, heteroaryl and substituted heteroaryl;
[0012] or a pharmaceutically acceptable salt thereof.
[0013] In some embodiments, at least one of R 3 and R 4 is phenyl. In some embodiments, at least one of R 3 and R 4 is 4-hydroxyphenyl. In some embodiments, at least one of R 3 and R 4 is 4-t-butoxyphenyl. In some embodiments, at least one of R 3 and R 4 is 2-indolyl. In some embodiments, R 3 and R 4 are both phenyl. In some embodiments, one of R 3 and R 4 is phenyl and the other of R 3 and R 4 is 4-hydroxyphenyl. In some embodiments, one of R 3 and R 4 is phenyl and the other of R 3 and R 4 is 4-t-butoxyphenyl. In some embodiments, one of R 3 and R 4 is phenyl and the other of R 3 and R 4 is 2-indolyl. In some embodiments, the carbon to which —CH 2 —R 3 is attached has absolute (R)-stereochemistry. In some embodiments, the carbon to which —CH 2 —R 3 is attached has absolute (S)-stereochemistry. In some embodiments, the carbon to which —CH 2 —R 4 is attached has absolute (R)-stereochemistry. In some embodiments, the carbon to which —CH 2 —R 4 is attached has absolute (S)-stereochemistry. In some embodiments, one of k, m, n and p is 1, and the remainder of k, m, n and p are 0. In some embodiments, two of k, m, n and p are 1, and the remainder of k, m, n and p are 0. In some embodiments, at least one of k and m is not 0. In some embodiments, at least one of n and p is not 0. In some embodiments, at least one of k and m is not 0 and at least one of n and p is not 0. In some embodiments, both k and n are 0. In some embodiments, both k and n are 0, one of m and p is 0, and the other of m and p is 1. In some embodiments, both k and n are 0 and both m and p are 1. In some embodiments, all four amino acids are L-amino acids. In some embodiments, three of the amino acids are L-amino acids and one of the amino acids is a D-amino acid. In some embodiments, two of the amino acids are L-amino acids and two of the amino acids are D-amino acids. In some embodiments, one of the amino acids is an L-amino acid and three of the amino acids are D-amino acids. In some embodiments, all four amino acids are D-amino acids.
[0014] In some embodiments, R and R′ are taken together to form —(CH 2 ) 3 —, i.e. R and R′ are taken together to form —CR 1 R 1′ —X—CH 2 — wherein R 1 and R 1′ are both H and X is CH 2 . In some embodiments, R″ and R′″ are taken together to form —(CH 2 ) 3 —, i.e. R″ and R′″ are taken together to form —CR 2 R 2′ —X′—CH 2 — wherein R 2 and R 2′ are both H and X′ is CH 2 . In some embodiments, R and R′ are taken together to form —(CH 2 ) 4 —, i.e. R and R′ are taken together to form —CR 1 R 1 —X—CH 2 — wherein R 1 and R 1′ are both H and X is (CH 2 ) 2 . In some embodiments, R″ and R′″ are taken together to form —(CH 2 ) 4 —, i.e. R″ and R′″ are taken together to form —CR 2 R 2′ —X—CH 2 — wherein R 2 and R 2′ are both H and X is (CH 2 ) 2 . In some embodiments, R and R′ are taken together to form —CH 2 —CH(OH)—CH 2 —, i.e. R and R′ are taken together to form —CR 1 R 1′ —X—CH 2 — wherein R 1 and R 1′ are both H and X is CH(OH). In some embodiments, R″ and R′″ are taken together to form —CH 2 —CH(OH)—CH 2 —, i.e. R″ and R′″ are taken together to form —CR 2 R 2′ —X′—CH 2 — wherein R 2 and R 2′ are both H and X′ is CH(OH). In some embodiments in which R and R′ are taken together, the carbon at which R′ is attached has absolute (S)-stereochemistry. In some embodiments in which R and R′ are taken together, the carbon at which R′ is attached has absolute (R)-stereochemistry. In some embodiments in which R″ and R′″ are taken together, the carbon at which R′″ is attached has absolute (S)-stereochemistry. In some embodiments in which R″ and R′″ are taken together, the carbon at which R′″ is attached has absolute (R)-stereochemistry.
[0015] In some embodiments, the compound is selected from the group consisting of:
[0000]
[0000] In some embodiments, the compound is a compound of formula I-1. In some embodiments, the compound is a compound of formula I-2. In some embodiments, the compound is a compound of formula I-3. In some embodiments, the compound is a compound of formula I-4. In some embodiments, the compound is a compound of formula I-5. In some embodiments, the compound is a compound of formula I-6. In some embodiments, the compound is a compound of formula I-7. In some embodiments, the compound is a compound of formula I-8.
[0016] In some embodiments, the compound is selected from the group consisting of:
[0000]
[0000] In some embodiments, the compound is a compound of formula I-A. In some embodiments, the compound is a compound of formula I-B. In some embodiments, the compound is a compound of formula I-C. In some embodiments, the compound is a compound of formula I-D. In some embodiments, the compound is a compound of formula I-E. In some embodiments, the compound is a compound of formula I-F. In some embodiments, the compound is a compound of formula I-G. In some embodiments, the compound is a compound of formula I-H. In some embodiments, the compound is a compound of formula I-I. In some embodiments, the compound is a compound of formula I-J. In some embodiments, the compound is a compound of formula I-K. In some embodiments, the compound is a compound of formula I-L. In some embodiments, the compound is a compound of formula I-M. In some embodiments, the compound is a compound of formula I-N. In some embodiments, the compound is a compound of formula I-O. In some embodiments, the compound is a compound of formula I-P.
[0017] In some embodiments, one or more amino groups in the compound of Formula I are in protected form.
[0018] There is also provided, in accordance with an embodiment of the invention, a pharma-ceutical composition comprising a compound of formula I and a pharmaceutically acceptable carrier, excipient or diluent therefor. In some embodiments, the compound is a compound of formula I-1. In some embodiments, the compound is a compound of formula I-2. In some embodiments, the compound is a compound of formula I-3. In some embodiments, the compound is a compound of formula I-4. In some embodiments, the compound is a compound of formula I-5. In some embodiments, the compound is a compound of formula I-6. In some embodiments, the compound is a compound of formula I-7. In some embodiments, the compound is a compound of formula I-8. In some embodiments, the compound is a compound of formula I-A. In some embodiments, the compound is a compound of formula I-B. In some embodi-ments, the compound is a compound of formula I-C. In some embodiments, the compound is a compound of formula I-D. In some embodiments, the compound is a compound of formula I-E. In some embodiments, the compound is a compound of formula I-F. In some embodi-ments, the compound is a compound of formula I-G. In some embodiments, the compound is a compound of formula I-H. In some embodiments, the compound is a compound of formula I-I. In some embodiments, the compound is a compound of formula I-J. In some embodiments, the compound is a compound of formula I-K. In some embodiments, the compound is a compound of formula I-L. In some embodiments, the compound is a compound of formula I-M. In some embodiments, the compound is a compound of formula I-N. In some embodiments, the compound is a compound of formula I-O. In some embodiments, the compound is a compound of formula I-P.
[0019] There is also provided, in accordance with an embodiment of the invention, a method of suppressing immune response in a patient, comprising administering to a patient in need thereof an efficacious amount of a compound of formula I. In some embodiments, the immune response which is suppressed is inflammation. In some embodiments the immune response which is suppressed is transplant rejection. In some embodiments, the compound is a compound of formula I-1. In some embodiments, the compound is a compound of formula I-2. In some embodiments, the compound is a compound of formula I-3. In some embodiments, the compound is a compound of formula I-4. In some embodiments, the compound is a compound of formula I-5. In some embodiments, the compound is a compound of formula I-6. In some embodiments, the compound is a compound of formula I-7. In some embodiments, the compound is a compound of formula I-8. In some embodiments, the compound is a compound of formula I-A. In some embodiments, the compound is a compound of formula I-B. In some embodiments, the compound is a compound of formula I-C. In some embodiments, the compound is a compound of formula I-D. In some embodiments, the compound is a compound of formula I-E. In some embodiments, the compound is a compound of formula I-F. In some embodiments, the compound is a compound of formula I-G. In some embodiments, the compound is a compound of formula I-H. In some embodiments, the compound is a compound of formula I-I. In some embodiments, the compound is a compound of formula I-J. In some embodiments, the compound is a compound of formula I-K. In some embodiments, the compound is a compound of formula I-L. In some embodiments, the compound is a compound of formula I-M. In some embodiments, the compound is a compound of formula I-N. In some embodiments, the compound is a compound of formula I-O. In some embodiments, the compound is a compound of formula I-P.
[0020] There is also provided, in accordance with an embodiment of the invention, a method of treating or preventing an immune-mediated disease or condition in a patient, comprising administering to a patient in need thereof an efficacious amount of a compound of formula I. There is also provided, in accordance with an embodiment of the invention, a method for lowering the toxicity profile of a second drug, comprising administering a compound of formula I in conjunction with the second drug. In some embodiments, the immune-mediated disease or condition is selected from the group consisting of auto-immune diseases, inflam-mation processes, transplant rejection, and allergic reactions. In some embodiments, the immune-mediated disease or condition is selected from Psoriasis, lichen planus and other papulosquamous disorders. In some embodiments, the immune-mediated disease or condition is selected from eczema and dermatitis. In some embodiments, the eczemea or dermatitis is selected from eczema, atopic eczema, seborrheic dermatitis, and pompholyx. In some embodiments, the immune-mediated disease or condition is a skin reaction to sunlight. In some embodiments, the immune-mediated disease or condition selected from non-specific skin irritation and insect bite. In some embodiments, the immune-mediated disease or condition is a urticaria. In some embodiments, the immune-mediated disease or condition is selected from the group consisting of a primary skin tumor (e.g. melanoma); rheumatoid arthritis (both autoimmune and elicited by infection); Crohn's disease; inflammatory bowel disease; irritable bowel syndrome; a neurodegenerative disease (e.g. multiple sclerosis); Parkinson's disease; Graft-versus-Host reaction; severe psoriasis; and atopic dermatitis. In some embodiments, the compound of formula I is administered in conjunction with a chemotherapeutic drug in order to reduce the toxic effects of the chemotherapeutic drug. In some embodiments, the compound is a compound of formula I-1. In some embodiments, the compound is a compound of formula I-2. In some embodiments, the compound is a compound of formula I-3. In some embodi-ments, the compound is a compound of formula I-4. In some embodiments, the compound is a compound of formula I-5. In some embodiments, the compound is a compound of formula I-6. In some embodiments, the compound is a compound of formula I-7. In some embodiments, the compound is a compound of formula I-8. In some embodiments, the compound is a compound of formula I-A. In some embodiments, the compound is a compound of formula I-B. In some embodiments, the compound is a compound of formula I-C. In some embodiments, the compound is a compound of formula I-D. In some embodiments, the compound is a compound of formula I-E. In some embodiments, the compound is a compound of formula I-F. In some embodiments, the compound is a compound of formula I-G. In some embodiments, the compound is a compound of formula I-H. In some embodiments, the compound is a compound of formula I-I. In some embodiments, the compound is a compound of formula I-J. In some em-bodiments, the compound is a compound of formula I-K. In some embodiments, the compound is a compound of formula I-L. In some embodiments, the compound is a compound of formula I-M. In some embodiments, the compound is a compound of formula I-N. In some embodiments, the compound is a compound of formula I-O. In some embodiments, the compound is a compound of formula I-P.
[0021] There is also provided, in accordance with an embodiment of the invention, a kit, comprising a compound of formula I and instructions for using the compound to (a) suppress an immune response in a patient, (b) treat or prevent an immune-mediated disease or condition in a patient, or (c) lower the toxicity profile of a second drug. In some embodiments, the immune response is inflammation. In some embodiments the immune response is transplant rejection. In some embodiments, the immune-mediated disease or condition is selected from the group consisting of auto-immune diseases, inflammation processes, transplant rejection, allergic reactions. In some embodiments, the immune-mediated disease or condition is selected from Psoriasis, lichen planus and other papulosquamous disorders. In some embodi-ments, the immune-mediated disease or condition is selected from eczema and dermatitis. In some embodiments, the eczemea or dermatitis is selected from eczema, atopic eczema, sebor-rheic dermatitis, and pompholyx. In some embodiments, the immune-mediated disease or con-dition is a skin reaction to sunlight. In some embodiments, the immune-mediated disease or condition selected from non-specific skin irritation and insect bite. In some embodiments, the immune-mediated disease or condition is a urticaria. In some embodiments, the immune-mediated disease or condition is selected from the group consisting of a primary skin tumor (e.g. melanoma); rheumatoid arthritis (both autoimmune and elicited by infection); Crohn's disease; inflammatory bowel disease; irritable bowel syndrome; a neurodegenerative disease (e.g. multiple sclerosis); Parkinson's disease; Graft-versus-Host reaction; severe psoriasis; and atopic dermatitis. In some embodiments, the instructions instruct administering the compound of formula I in conjunction with a chemotherapeutic drug in order to reduce the toxic effects of the chemotherapeutic drug. In some embodiments, the compound is a compound of formula I-1. In some embodiments, the compound is a compound of formula I-2. In some embodiments, the compound is a compound of formula I-3. In some embodiments, the compound is a compound of formula I-4. In some embodiments, the compound is a compound of formula I-5. In some embodiments, the compound is a compound of formula I-6. In some embodiments, the compound is a compound of formula I-7. In some embodiments, the compound is a compound of formula I-8. In some embodiments, the compound is a compound of formula I-A. In some embodiments, the compound is a compound of formula I-B. In some embodiments, the compound is a compound of formula I-C. In some embodiments, the compound is a compound of formula I-D. In some embodiments, the compound is a compound of formula I-E. In some embodiments, the compound is a compound of formula I-F. In some embodiments, the compound is a compound of formula I-G. In some embodiments, the compound is a compound of formula I-H. In some embodiments, the compound is a compound of formula I-I. In some embodiments, the compound is a compound of formula I-J. In some embodiments, the compound is a compound of formula I-K. In some embodiments, the compound is a compound of formula I-L. In some embodiments, the compound is a compound of formula I-M. In some embodiments, the compound is a compound of formula I-N. In some embodiments, the compound is a compound of formula I-O. In some embodiments, the compound is a compound of formula I-P.
[0022] There is also provided, in accordance with an embodiment of the invention, a method for making a compound of formula I, comprising cyclizing a compound having the formula II-1, II-2, II-3 or II-4, wherein R, R′, R″, R′″, R 3 , R 4 , k, m, n and p are as defined in formula I (collectively referred to hereinafter as compounds of formula II):
[0000]
[0000] to the corresponding compound of formula I. In some embodiments, the method further comprises synthesizing the compound of formula II-1, II-2, II-3 or II-4. In some embodiments, the compound of formula II-1, II-2, II-3 or II-4 is formed by solid-phase synthesis.
[0023] In accordance with embodiments of the invention, there are also provided compounds of formulae II-1, II-2, II-3 and II-4 per se, as well as protected versions of these compounds (e.g. in which one or more amino groups, such as the N-terminal amino group or a side chain amino group, are protected, e.g. by tert-butoxycarbonyl) and these compounds, in protected or unprotected form, when bound to a solid-phase resin. Hereinafter, unless specified otherwise or illogical in the given context, when reference is made to a compound of formula II or a sub-genus or sub-species thereof, such reference is intended to include such compound in a form in which it is (a)(i) at least partly protected or (a)(ii) completely un- or deprotected; (b)(i) bound to a resin (1) directly or (2) through a linker, or (b)(ii) not bound to a resin; or a combination of conditions (a) and (b). Furthermore, as depicted herein, for the sake of convenience, free, non-protected linear peptides are shown as neutral molecules, viz. having H 2 N— at the N-terminus and —COOH at the C-terminus; however, it will be appreciated that the actual charge on these moieties, as well as on any ionizable side chain moieties (e.g. carboxylic acid or amine moieties in the side chains) will depend on the pH of surroundings, and will not necessarily be as shown.
[0024] In some embodiments, the compound of formula II is selected from the group consisting of:
[0000]
[0000] In some embodiments the compound is a compound of formula II-4-a. In some embodiments, the compound is a compound of formula II-1-a. In some embodiments, the compound is a compound of formula II-2-a. In some embodiments, the compound is a compound of formula II-3-a. In some embodiments, the compound is a compound of formula II-4-b. In some embodiments, the compound is a compound of formula II-1-b. In some embodiments, the compound is a compound of formula II-2-b. In some embodiments, the compound is a compound of formula II-3-b. In some embodiments, the compound is a compound of formula II-4-c. In some embodiments, the compound is a compound of formula II-1-c. In some embodiments, the compound is a compound of formula II-2-c. In some embodiments, the compound is a compound of formula II-3-c. In some embodiments, the compound is a compound of formula II-4-d. In some embodiments, the compound is a compound of formula II-1-d. In some embodiments, the compound is a compound of formula II-2-d. In some embodiments, the compound is a compound of formula II-3-d. In some embodiments, the compound is a compound of formula II-4-e. In some embodiments, the compound is a compound of formula II-1-e. In some embodiments, the compound is a compound of formula II-2-e. In some embodiments, the compound is a compound of formula II-3-e. In some embodiments, the compound is a compound of formula II-4-f. In some embodiments, the compound is a compound of formula II-1-f. In some embodiments, the compound is a compound of formula II-2-f. In some embodiments, the compound is a compound of formula II-3-f. In some embodiments, the compound is a compound of formula II-4-g. In some embodiments, the compound is compound of formula II-1-g. In some embodiments, the compound is compound of formula II-2-g. In some embodiments, the compound is compound of formula II-3-g. In some embodiments, the compound is a compound of formula II-4-h. In some embodiments, the compound is compound of formula II-1-h. In some embodiments, the compound is compound of formula II-2-h. In some embodiments, the compound is compound of formula II-3-h.
[0025] In some embodiments the compound of formula II is selected from the group consisting of:
[0000]
[0026] In some embodiments, the compound is a compound of formula II-A-1. In some embodiments, the compound is a compound of formula II-A-2. In some embodiments, the compound is a compound of formula II-A-3. In some embodiments, the compound is a compound of formula II-A-4. In some embodiments, the compound is a compound of formula II-B-1. In some embodiments, the compound is a compound of formula II-B-2. In some embodi-ments, the compound is a compound of formula II-B-3. In some embodiments, the compound is a compound of formula II-B-4. In some embodiments, the compound is a compound of formula II-C-1. In some embodiments, the compound is a compound of formula II-C-2. In some embodiments, the compound is a compound of formula II-C-3. In some embodiments, the compound is a compound of formula II-C-4. In some embodiments, the compound is a compound of formula II-D-1. In some embodiments, the compound is a compound of formula II-D-2. In some embodiments, the compound is a compound of formula II-D-3. In some embodiments, the compound is a compound of formula II-D-4. In some embodiments, the compound is a compound of formula II-E-1. In some embodiments, the compound is a compound of formula II-E-2. In some embodiments, the compound is a compound of formula II-E-3. In some embodiments, the compound is a compound of formula II-E-4. In some embodiments, the compound is a compound of formula II-F-1. In some embodiments, the compound is a compound of formula II-F-2. In some embodiments, the compound is a compound of formula II-F-3. In some embodiments, the compound is a compound of formula II-F-4. In some embodiments, the compound is a compound of formula II-G-1. In some embodiments, the compound is a compound of formula II-G-2. In some embodiments, the compound is a compound of formula II-G-3. In some embodiments, the compound is a compound of formula II-G-4. In some embodiments, the compound is a compound of formula II-H-1. In some embodiments, the compound is a compound of formula II-H-2. In some embodiments, the compound is a compound of formula II-H-3. In some embodiments, the compound is a compound of formula II-H-4. In some embodiments, the compound is a compound of formula II-J-1. In some embodiments, the compound is a compound of formula II-J-2. In some embodiments, the compound is a compound of formula II-J-3. In some embodiments, the compound is a compound of formula II-J-4. In some embodiments, the compound is a compound of formula II-K-1. In some embodiments, the compound is a compound of formula II-K-2. In some embodiments, the compound is a compound of formula II-K-3. In some embodiments, the compound is a compound of formula II-K-4. In some embodiments, the compound is a compound of formula II-L-1. In some embodiments, the compound is a compound of formula II-L-2. In some embodiments, the compound is a compound of formula II-L-3. In some embodiments, the compound is a compound of formula II-L-4. In some embodiments, the compound is a compound of formula II-M-1. In some embodiments, the compound is a compound of formula II-M-2. In some embodiments, the compound is a compound of formula II-M-3. In some embodiments, the compound is a compound of formula II-M-4. In some embodiments, the compound is a compound of formula II-N-1. In some embodiments, the compound is a compound of formula II-N-2. In some embodiments, the compound is a compound of formula II-N-3. In some embodiments, the compound is a compound of formula II-N-4. In some embodiments, the compound is a compound of formula II-O-1. In some embodiments, the compound is a compound of formula II-O-2. In some embodiments, the compound is a compound of formula II-O-3. In some embodiments, the compound is a compound of formula II-O-4. In some embodiments, the compound is a compound of formula II-P-1. In some embodiments, the compound is a compound of formula II-P-2. In some embodiments, the compound is a compound of formula II-P-3. In some embodiments, the compound is a compound of formula II-P-4.
DETAILED DESCRIPTION
[0027] It has been found that compounds of formula I exhibit immunosuppressive and/or anti-inflammatory activity, while at the same time exhibiting less toxicity, than some known compounds. Thus compounds of formula I may be useful as immunosuppressive and/or anti-inflammatory agents. As used herein, the term “immune-mediated” refers to a disease or condition in which the body's immune system overreacts and/or attacks the body.
[0028] Throughout this specification the terms and substituents retain their definitions.
[0029] “Alkyl” is intended to include linear, branched, or cyclic saturated hydrocarbon structures and combinations thereof. Lower alkyl refers to alkyl groups of from 1 to 6 carbon atoms. Examples of lower alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, s- and t-butyl and the like. Preferred alkyl groups are those of C 20 or below. Cycloalkyl is a subset of alkyl and includes cyclic hydrocarbon groups of from 3 to 8 carbon atoms. Examples of cycloalkyl groups include c-propyl, c-butyl, c-pentyl, norbornyl and the like.
[0030] C 1 to C 20 hydrocarbon includes alkyl, cycloalkyl, polycycloalkyl, alkenyl, alkynyl, aryl and combinations thereof. Examples include benzyl, phenethyl, cyclohexylmethyl, camphoryl and naphthylethyl. The term “carbocycle” is intended to include ring systems consisting entirely of carbon but of any oxidation state. Thus (C 3 -C 10 ) carbocycle refers to such systems as cyclopropane, benzene and cyclohexene; (C 8 -C 12 ) carbopolycycle refers to such systems as norbornane, decalin, indane and naphthalene.
[0031] Alkoxy or alkoxyl refers to groups of from 1 to 8 carbon atoms of a straight, branched, cyclic configuration and combinations thereof attached to the parent structure through an oxygen atom. Examples include methoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy, cyclohexyloxy and the like. Lower-alkoxy refers to groups containing one to four carbons.
[0032] Oxaalkyl refers to alkyl residues in which one or more carbons has been replaced by oxygen. Examples include methoxypropoxy, 3,6,9-trioxadecyl and the like.
[0033] Acyl refers to groups of from 1 to 8 carbon atoms of a straight, branched, cyclic configuration, saturated, unsaturated and aromatic and combinations thereof, attached to the parent structure through a carbonyl functionality. One or more carbons in the acyl residue may be replaced by nitrogen, oxygen or sulfur as long as the point of attachment to the parent remains at the carbonyl. Examples include acetyl, benzoyl, propionyl, isobutyryl, t-butoxycarbonyl, benzyloxycarbonyl and the like. Lower-acyl refers to groups containing one to four carbons.
[0034] Aryl means 6-membered aromatic ring; a bicyclic 9- or 10-membered aromatic ring system; or a tricyclic 13- or 14-membered aromatic ring system. The aromatic 6- to 14-membered carbocyclic rings include, e.g., benzene, naphthalene, indane, tetralin, and fluorene.
[0035] Heteroaryl mean a 5- or 6-membered heteroaromatic ring containing 1-3 heteroatoms selected from O, N, or S; a bicyclic 9- or 10-membered heteroaromatic ring system containing 1-3 heteroatoms selected from O, N, or S; or a tricyclic 13- or 14-membered heteroaromatic ring system containing 1-3 heteroatoms selected from O, N, or S. The 5- to 10-membered aromatic heterocyclic rings include, e.g., imidazole, pyridine, indole, thiophene, benzopyranone, thiazole, furan, benzimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, tetrazole and pyrazole.
[0036] Arylalkyl refers to a substituent in which an aryl residue is attached to the parent structure through alkyl. Examples are benzyl, phenethyl and the like. Heteroarylalkyl refers to a substituent in which a heteroaryl residue is attached to the parent structure through alkyl. Examples include, e.g., pyridinylmethyl, pyrimidinylethyl and the like.
[0037] Heterocycle means a cycloalkyl or aryl residue in which from one to three carbons is replaced by a heteroatom selected from the group consisting of N, O and S. The nitrogen and sulfur heteroatoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized. Examples of heterocycles include pyrrolidine, pyrazole, pyrrole, indole, quinoline, isoquinoline, tetrahydroisoquinoline, benzofuran, benzodioxan, benzodioxole (commonly referred to as methylenedioxyphenyl, when occurring as a substituent), tetrazole, morpholine, thiazole, pyridine, pyridazine, pyrimidine, thiophene, furan, oxazole, oxazoline, isoxazole, dioxane, tetrahydrofuran and the like. It is to be noted that heteroaryl is a subset of heterocycle in which the heterocycle is aromatic. Examples of heterocyclyl residues additionally include piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxo-pyrrolidinyl, 2-oxoazepinyl, azepinyl, 4-piperidinyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, isothiazolyl, quinuclidinyl, isothiazolidinyl, benzimidazolyl, thiadiazolyl, benzopyranyl, benzothiazolyl, tetrahydrofuryl, tetrahydropyranyl, thienyl, benzothienyl, thiamorpholinyl, thiamorpholinylsulfoxide, thiamorpholinylsulfone, oxadiazolyl, triazolyl and tetrahydroquinolinyl.
[0038] Substituted alkyl, aryl, cycloalkyl, heterocyclyl etc. refer to alkyl, aryl, cycloalkyl, or heterocyclyl wherein up to three H atoms in each residue are replaced with alkyl, halogen, haloalkyl, hydroxy, loweralkoxy, carboxy, carboalkoxy (also referred to as alkoxycarbonyl), carboxamido (also referred to as alkylaminocarbonyl), cyano, carbonyl, nitro, amino, alkylamino, dialkylamino, mercapto, alkylthio, sulfoxide, sulfone, acylamino, amidino, phenyl, benzyl, heteroaryl, phenoxy, benzyloxy, or heteroaryloxy.
[0039] The term “halogen” means fluorine, chlorine, bromine or iodine.
[0040] The following abbreviations and terms have the indicated meanings throughout:
Boc=t-butyloxy carbonyl c-=cyclo DCM=dichloromethane=methylene chloride=CH 2 Cl 2 DIEA=N,N-diisopropylethyl amine DIPEA=diisopropylethylamine DMF=N,N-dimethylformamide Fmoc=9-fluorenylmethoxycarbonyl HATU=O-(7-Azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU=O-(benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HOAc=acetic acid HOAt=1-hydroxy-7-azabenzotriazole HOBt=1-hydroxybenzotriazole Hyp=4-hydroxyproline Me=methyl Pip=Pipecolic acid Phe=phenylalanine Pro=proline PyBOP=O-(benzotriazol-1-yl)-trispyrrolidinephosphonium hexafluorophosphate rt=room temperature TBTU=O-(benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate TFA=trifluoroacetic acid t-Hyp=trans-4-hydroxyproline Trp=tryptophan Tyr=tyrosine Tyr(tBu)=(O-tert-butyl)tyrosine
[0066] Furthermore, a comprehensive list of abbreviations utilized by organic chemists (i.e. persons of ordinary skill in the art) appears in the first issue of each volume of the Journal of Organic Chemistry . The list, which is typically presented in a table entitled “Standard List of Abbreviations” is incorporated herein by reference. In addition, with respect to non-naturally occurring amino acids in which an additional methylene group is present in the backbone, the notation “β 3 -Ho-” (or “beta 3-homo-”) is used herein to refer to an amino acid having an extra methylene (—CH 2 —) in the backbone between the side-chain bearing carbon atom and the terminal nitrogen atom; the notation “β 2 -Ho-” (or “beta 2-homo-”) is used herein to refer to an amino acid having an extra methylene in the backbone between the side-chain bearing carbon atom and the terminal carbon atom.
[0067] Embodiments of the present invention include compounds of formula I in the form of salts, in particular acid addition salts. Suitable salts include those formed with both organic and inorganic acids. Such acid addition salts will normally be pharmaceutically acceptable, although salts of non-pharmaceutically acceptable salts may be of utility in the preparation and purification of the compound in question. Thus, preferred salts include those formed from hydrochloric, hydrobromic, sulphuric, citric, tartaric, phosphoric, lactic, pyruvic, acetic, succinic, oxalic, fumaric, maleic, oxaloacetic, methanesulphonic, ethanesulphonic, p-toluenesulphonic, benzenesulphonic and isethionic acids. Salts of the compounds of formula I can be made by reacting the appropriate compound in the form of the free base with the appropriate acid.
[0068] The compounds of formula I in accordance with the embodiments of the invention are cyclic tetrapeptides. The synthesis of these peptides may be accomplished by cyclizing corresponding linear peptides that are themselves synthesized using methodologies known in the art; see, for example, Merrifield, J. Am. Chem. Soc., 85:2149 (1964); Houghten, Proc. Natl. Acad. Sci. USA, 82:5132 (1985); Kelley & Winkler in Genetic Engineering Principles and Methods , Setlow, J. K, ed., Plenum Press, N.Y., vol. 12, pp 1-19 (1990); Stewart & Young, Solid Phase Peptide Synthesis , Pierce Chemical Co., Rockford, Ill. (1984); Mergler et al. (1988) Tetrahedron Letters 29:4005-4008; Mergler et al. (1988) Tetrahedron Letters 29:4009-4012; Kamber et al. (eds), Peptides, Chemistry and Biology , ESCOM, Leiden (1992) pp. 525-526; Riniker et al. (1993) Tetrahedron Letters 49:9307-9320; Lloyd-Williams et al. (1993) Tetrahedron Letters 49:11065-11133; Andersson et al. (2000) Biopolymers 55:227-250; Bray, Nature Reviews 2:587-593 (2003), U.S. Pat. Nos. 4,105,603, 3,972,859, 3,842,067, 3,862,925, 6,015,881, 6,197,927, and 7,439,222. Such synthesis may be accomplish via liquid-phase or solid-phase synthesis, or by a combination of both, as is known in the art.
[0069] Liquid phase methods (often referred to as solution phase methods) of synthesis carry out all reactions in a homogeneous phase. Successive amino acids are coupled in solution until the desired peptide material is formed. During synthesis, successive intermediate peptides are purified by precipitation and/or washes.
[0070] In solid phase peptide synthesis (SPPS), a first amino acid or peptide group is bound to an insoluble support, such as a resin. Successive amino acids or peptide groups are added to the first amino acid or peptide group until the peptide material of interest is formed. The product of solid phase synthesis is thus a peptide bound to an insoluble support. Peptides synthesized via SPPS techniques are then cleaved from the resin, and the cleaved peptide is isolated.
[0071] More specifically, solid phase synthesis begins at the carboxy terminus of the putative peptide by coupling a protected amino acid to an inert solid support. The inert solid support can be any macromolecule capable of serving as an anchor for the C-terminus of the initial amino acid. Typically, the macromolecular support is a cross-linked polymeric resin (e.g. a polyamide or polystyrene resin) as shown in FIGS. 1-1 and 1-2, on pages 2 and 4 of Stewart & Young, supra. In some cases, the C-terminal amino acid is coupled to a polystyrene resin to form a benzyl ester. A macromolecular support is selected such that the peptide anchor link is stable under the conditions used to deprotect the α-amino group of the blocked amino acids in peptide synthesis. If a base-labile α-protecting group is used, then it is desirable to use an acid-labile link between the peptide and the solid support. For example, an acid-labile ether resin is effective for base-labile Fmoc-amino acid peptide synthesis as described on page 16 of Stewart & Young, supra. Alternatively, a peptide anchor link and α-protecting group that are differentially labile to acidolysis can be used. For example, an aminomethyl resin such as the phenylacetamidomethyl (Pam) resin works well in conjunction with Boc-amino acid peptide synthesis as described on pages 11-12 of Stewart & Young, supra. Guiller et al., Chem. Rev. 2000, 100, 2091-2157, reviewed linkers and cleavage strategies in solid-phase organic synthesis and combinatorial chemistry, including peptide synthesis.
[0072] After the initial amino acid is coupled to an inert solid support, the α-amino protecting group of the initial amino acid is removed with, for example, trifluoroacetic acid (TFA) in methylene chloride and neutralizing in, for example, triethylamine (TEA). Following deprotection of the initial amino acid's α-amino group, the next α-amino and sidechain protected amino acid in the synthesis is added. The remaining α-amino and, if necessary, side chain protected amino acids are then coupled sequentially in the desired order by condensation to obtain an intermediate compound connected to the solid support. Alternatively, some amino acids may be coupled to one another to form a fragment of the desired peptide followed by addition of the peptide fragment to the growing solid phase peptide chain
[0073] The condensation reaction between two amino acids, or an amino acid and a peptide, or a peptide and a peptide can be carried out according to the usual condensation methods such as the axide method, mixed acid anhydride method, DCC(N,N′-dicyclohexylcarbodiimide) or DIC(N,N′-diisopropylcarbodiimide) methods, active ester method, p-nitrophenyl ester method, BOP (benzotriazole-1-yl-oxy-tris [dimethylamino]phosphonium hexafluorophosphate) method, N-hydroxysuccinic acid imido ester method, etc, and Woodward reagent K method.
[0074] It is common in the chemical syntheses of peptides to protect any reactive side-chain groups of the amino acids with suitable protecting groups. Ultimately, these protecting groups are removed after the desired polypeptide chain has been sequentially assembled. Also common is the protection of the α-amino group on an amino acid or peptide fragment while the C-terminal carboxy group of the amino acid or peptide fragment reacts with the free N-terminal amino group of the growing solid phase polypeptide chain, followed by the selective removal of the α-amino protecting group to permit the addition of the next amino acid or peptide fragment to the solid phase polypeptide chain. Accordingly, it is common in polypeptide synthesis that an intermediate compound is produced which contains each of the amino acid residues located in the desired sequence in the peptide chain wherein individual residues still carry side-chain protecting groups. These protecting groups can be removed substantially at the same time to produce the desired polypeptide product following removal from the solid phase.
[0075] α- and ω-amino side chains can be protected, for example, with benzyloxycarbonyl (abbreviated Z), isonicotinyloxycarbonyl (iNoc), o-chlorobenzyloxycarbonyl [Z(2Cl) or 2-Cl—Z], p-nitrobenzyloxycarbonyl [Z(NO 2 )], p-methoxybenzyloxycarbonyl [Z(OMe)], t-butoxy-carbonyl (Boc), t-amyloxycarbonyl (Aoc), isobornyloxycarbonyl, adamantyloxy-carbonyl (Adoc), 2-(4-biphenyl)-2-propyloxycarbonyl (Bpoc), 9-fluorenylmethoxycarbonyl (Fmoc), methylsulfonyethoxycarbonyl (Msc), trifluoroacetyl, phthalyl (Pht), formyl (For), 2-nitro-phenylsulphenyl (Nps), diphenylphosphinothioyl (Ppt), and dimethylphosphinothioyl (Mpt) groups, and the like. Additional examples of side chain protecting groups include acetyl (Ac), benzoyl (Bz), tert butyl (t-Bu), triphenylmethyl (trityl, Trt), tetrahydropyranyl, benzyl (Bzl), 2,6-dichlorobenzyl, nitro, p-toluenesulfonyl (Tos), xanthyl (Xan), benzyl, methyl, ethyl, and t-butyl ester, and aromatic or aliphatic urethan-type protecting groups, photolabile groups such as nitro veratryl oxycarbonyl (Nvoc), and fluoride labile groups such as trimethylsilylethyloxycarbonyl (TEOC).
[0076] Examples of amino terminal protecting groups (also referred to herein as N-terminal protecting groups) include: (1) acyl-type protecting groups, such as formyl, acrylyl (Acr), benzoyl (Bz) and acetyl (Ac); (2) aromatic urethan-type protecting groups, such as benzyloxy-carbonyl (Z) and substituted Z, such as p-chlorobenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-bromobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl; (3) aliphatic urethan protecting groups, such as t-butyloxycarbonyl (BOC), diisopropylmethoxycarbonyl, isopropyloxycar-bonyl, ethoxycarbonyl, allyloxycarbonyl; (4) cycloalkyl urethan-type protecting groups, such as 9-fluorenyl-methyloxycarbonyl (Fmoc), cyclopentyloxycarbonyl, adamantyloxycarbonyl, and cyclohexyloxycarbonyl; and (5) thiourethan-type protecting groups, such as phenylthio-carbonyl. Preferred protecting groups include 9-fluorenylmethyloxycarbonyl (Fmoc), 2-(4-biphenylyl)-propyl(2)oxycarbonyl (Bpoc), 2-phyenlpropyl(2)-oxycarbonyl (Poc), and t-butyloxycarbonyl (Boc).
[0077] Protective groups for the carboxy functional group are exemplified by benzyl ester (OBzl), cyclohexyl ester (Chx), 4-nitrobenzyl ester (ONb), t-butyl ester (Obut), 4-pyridylmeth-yl ester (OPic), and the like. It is often desirable that specific amino acids such as arginine, cysteine, and serine possessing a functional group other than amino and carboxyl groups are protected by a suitable protective group. For example, the guanidino group of arginine may be protected with nitro, p-toluenesulfonyl, benzyloxycarbonyl, adamantyloxycarbonyl, p-meth-oxybenzesulfonyl, 4-methoxy-2,6-dimethylbenzenesulfonyl (Nds), 1,3,5-trimethylphenysul-fonyl (Mts), and the like. The thiol group of cysteine can be protected with p-methoxybenzyl, trityl, and the like.
[0078] While it may be possible for the compounds of formula Ito be administered as the raw chemical, it is preferable to present them as a pharmaceutical composition. According to a further aspect, there are provided in accordance with embodiments of the present invention a pharmaceutical composition comprising a compound of formula I or a pharmaceutically acceptable salt or solvate thereof, together with one or more pharmaceutically carriers thereof and optionally one or more other therapeutic ingredients. The carrier(s) must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
[0079] The formulations include those suitable for oral, parenteral (including subcutaneous, intradermal, intramuscular, intravenous and intraarticular), rectal and topical (including dermal, buccal, sublingual and intraocular) administration. The most suitable route may depend upon the condition and disorder of the recipient. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Methods for making such formulations include the step of bringing into association a compound of formula I or a pharmaceutically acceptable salt or solvate thereof (“active ingredient”) with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation.
[0080] Formulations in accordance with embodiments of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.
[0081] A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, lubricating, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide sustained, delayed or controlled release of the active ingredient therein.
[0082] Formulations for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient. Formulations for parenteral administration also include aqueous and non-aqueous sterile suspensions, which may include suspending agents and thickening agents. The formulations may be presented in unit-dose of multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of a sterile liquid carrier, for example saline, phosphate-buffered saline (PBS) or the like, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
[0083] Formulations for rectal administration may be presented as a suppository with the usual carriers such as cocoa butter or polyethylene glycol.
[0084] Formulations for topical administration in the mouth, for example buccally or sublingually, include lozenges comprising the active ingredient in a flavoured basis such as sucrose and acacia or tragacanth, and pastilles comprising the active ingredient in a basis such as gelatin and glycerin or sucrose and acacia.
[0085] Preferred unit dosage formulations are those containing an effective dose, as hereinbelow recited, or an appropriate fraction thereof, of the active ingredient.
[0086] It should be understood that in addition to the ingredients particularly mentioned above, the formulations in accordance with embodiments of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavoring agents.
[0087] As stated, in accordance with embodiments of the invention, compounds in accordance with embodiments of the invention may be used for the treatment or prevention of certain diseases or conditions. The term “preventing” as used herein refers to administering a medicament beforehand to forestall or obtund an attack. The person of ordinary skill in the medical art (to which the present method of use claims are directed) recognizes that the term “prevent” is not an absolute term. In the medical art it is understood to refer to the prophylactic administration of a drug to substantially diminish the likelihood or seriousness of a condition, and this is the sense intended in applicants' claims. The reader's attention is directed to the Physician's Desk Reference, a standard text in the field, in which the term “prevent” occurs hundreds of times. No person of skill in the medical art construes the term in an absolute sense. Similarly, where it is stated that compounds in accordance with embodiments of the invention may be used to suppress an immune response, “suppress” will be understood to include reducing the degree of the response, and not necessarily absolutely preventing the response.
[0088] It may be found upon examination that compounds that are not presently excluded from the claims are not patentable to the inventors in this application. In that case, the exclusion of species and genera in applicants' claims are to be considered artifacts of patent prosecution and not reflective of the inventors' concept or description of their invention. The invention, in a composition aspect, is all compounds of formulae I and II, except those that are in the public's possession.
[0089] Embodiments of the invention will be better understood with reference to the figures, in which:
[0090] FIG. 1 shows antigen-specific increase of the ear thickness derived from the experiment described in Example 2;
[0091] FIG. 2 shows total numbers of cells in the parotid lymph nodes observed in the experiment described in Example 2;
[0092] FIG. 3 shows the content of viable and dead cells in the parotid lymph nodes described in Example 2;
[0093] FIG. 4 presents number and participation of cell types in the draining lymph nodes registered in the experiment described in Example 2;
[0094] FIG. 5 presents toxicity of the compound of formula IA against mononuclear cells from human blood in as described in Example 3;
[0095] FIG. 6 presents effects of the intraperitoneal administration of the compound of formula IA on the humoral immune response of mice to sheep erythrocytes as described in Example 4;
[0096] FIG. 7 shows effects of the intraperitoneal administration of the compound of formula IA on the cellular immune response to ovalbumin as described in Example 5;
[0097] FIGS. 8A and 8B show the effects of peptides in accordance with embodiments of the invention on PMBC survival in vitro;
[0098] FIGS. 9A and 9B show the effects of peptides in accordance with embodiments of the invention on PHA-induced PBMC proliferation in vitro;
[0099] FIGS. 10A and 10B show the effects of several compounds on changes in ear thickness in response to antigenic challenge, as described in Example 7;
[0100] FIG. 11 shows the permeability of capillary blood vessels in the Evans blue test, as described in Example 7;
[0101] FIG. 12 shows the total number of cells in the draining lymph nodes, as described in Example 7;
[0102] FIG. 13 shows the effects of the compounds on the numbers of circulating leukocytes, as described in Example 7;
[0103] FIG. 14 which shows the types of leukocytes present in different cases, as described in Example 7; and
[0104] FIG. 15 provides morphometric data on the number and composition of cells in mouse auricles, as described in Example 7.
Example 1
Synthesis of Cyclic Tetrapeptides
[0105] Cyclic tetrapeptides according to embodiments of the invention can be synthesized by the use of known peptide synthesis methods, such as solution-phase or solid-phase methods. In general the synthesis involves two consecutive steps: (1) synthesis of a linear tetrapeptide and (2) cyclization to yield the cyclic tetrapeptide. The linear tetrapeptide may be prepared in protected form and then deprotected prior to cyclization.
[0106] To illustrate, the synthesis of linear tetrapeptides on a solid support (Fmoc-L-phenylalanine attached to a Wang-type resin, or either L-beta-3-homophenylalanine or L-proline attached to a 2-chloro trityl resin) was conducted according to the following protocol:
[0000] 1. The resin was swelled in dimethylformamide (DMF) (0.25 mmol, 10 ml/g resin) for 15 min.
2. The Fmoc group was removed with a 20% solution of piperidine in DMF (2×20 min).
3. The resin was washed with DMF (3×2 min)
4. The resin was washed with methanol (MeOH) (3×2 min)
5. The resin was washed with dichloromethane (DCM) (3×2 min)
6. Amino acid or peptide amino groups on the resin were acylated by shaking with a mixture of Fmoc-protected amino acid (4 eq), HBTU or TBTU (4 eq) and DIPEA (4 eq) dissolved in anhydrous DMF (4 ml/mmol), for 20 hours.
7. The resin was washed with DCM (3×2 min)
8. The resin was washed with MeOH (3×2 min)
9. The resin was washed with DCM (3×2 min)
10. The Kaiser test (for all amino acids except proline) was used to estimate if all amino groups were acylated.
[0107] If the result of the Kaiser test was negative, the resin was washed with DMF (1×2 min.) and a new coupling cycle started from point 2 of the protocol. If the result of the Kaiser test was positive, acylation was repeated with half the amount of the reagent used for the first coupling. In the case of acylation of proline, the Kaiser test is not sensitive enough to determine the degree of acylation, and for that reason in the case of proline the coupling procedure was repeated with the half amount of reagents. In the case of repeated acylation, the following washings were carried out:
[0000] 7A. Washing with DCM (3×2 min)
8A. Washing with MeOH (3×2 min)
9A. Washing with DCM (3×2 min)
[0108] After the last coupling the resin was washed according to points 3-5 of the protocol. The Fmoc group was removed from the peptide as described in point 2, and the resin was washed again with DMF, MeOH and DCM as in points 3-5. Before the cleavage of the peptide from the polymeric support, the resin was dried overnight in a desiccator over KOH pellets under reduced pressure at room temperature.
[0109] Peptides were cleaved from the dried, Wang-type resin with a mixture of trifluoroacetic acid/water/triisopropylsilane 95:2.5:2.5 (v/v/v; 10 ml/1 g of peptidyl-resin). The solution obtained was partially evaporated at room temperature under reduced pressure and peptide was precipitated with 10 volumes of ether. After being filtered off, the crude peptide was dissolved in 0.05 M aqueous HCl and evaporated to dryness. The residue was dissolved in water and lyophilized.
[0110] Peptides were cleaved from 2-Cl-trityl resin by treatment with a 1:3:1 mixture of acetic acid/dichloromethane/trifluorethanol (v/v/v; 10 ml/1 g of peptidyl-resin). The resulting cleavage solution plus collected washings were filtered, evaporated to dryness at ambient temperature and reduced pressure, and the residue dissolved in a minimal volume of DCM, diluted with 20 volumes of hexane and re-evaporated (twice). Crude detached peptide was dissolved in water and lyophilized.
[0111] After lyophilized peptide was dried in a desiccator under vacuum over KOH and P 2 O 5 , it was ready for cyclisation.
[0112] In a typical synthesis following the above protocol, starting with Fmoc-Phe attached to the Wang resin (278 mg, 0.2 mmol, 0.72 mmol/g) and after sequential coupling of Fmoc-L-β 3 -homoPhe-OH, Fmoc-Pro-OH and again Fmoc-Pro-OH, the yield after lyophylization was 91 mg (82%) of crude linear peptide with a purity of 94% (HPLC).
[0113] Crude peptides were cyclized in DCM solution (peptide concentration 2×10 −4 millimoles/Liter) with the aid of PyBOP/HOAt/2,4,6-collidine (3:3:5), with disappearance of linear precursors being traced by injecting samples of reaction solutions on an analytical reverse-phase (RP)HPLC column. At the end of the cyclization, the solution was evaporated to dryness under reduced pressure and the residue was partitioned between ethyl acetate (1000 ml of solvent per 1 millimole of peptide and 0.5 N HCl in water (100 ml of solution per 1 millimole of peptide). Organic phase was washed consecutively with 0.5 N HCl in water (2×), water (1×), 1M NaHCO 3 (3×) and water (1×). Organic solvent was removed under reduced pressure and the residual solid was dissolved in dioxane and freeze-dried. The crude product was purified on a preparative Vydac C 18 or Kromasil C 8 reversed-phase column (250 mm/22 mm, 100 A, 10 μm) using an elution gradient of solvent B (0.038% TFA in 82% acetonitrile/water) in solvent A (0.05% TFA in water).
[0114] As an example of a cyclization reaction, a solution of H-Pro-Pro-β 3 -hPhe-Phe-OH×HCl (55.7 mg, 0.1 mmol) in 500 ml DCM was treated with PyBOP (157 mg, 0.3 mmol) and HOAt (40 mg, 0.3 mmol) in the presence of 2,4,6-collidine (67.5 μL, 0.5 mmol), yielding after work-up and purification 13.5 mg (27%) of the cyclic tetrapeptide with purity 99% as determined by HPLC.
[0115] In this manner, compounds of formulae I-A through I-P were synthesized. The following Table 1 provides some data for the compounds of formulae I-A through I-P.
[0000]
TABLE 1
HPLC (Vydac C 18 250 × 4.6 mm, 5 μm,
300 A, 1 mL/min, 45-75% B in 15 min.
A: 0.05% TFA/water, B: 0.038%
TFA/82% Acetonitrile/water)
MS (MH + )/MW
Purity
No.
calculated
t R (min)
(%, λ 214 nm)
I-A
503.45/502.6
4.79
99.35
I-B
503.47/502.6
5.96
99.00
I-C
517.49/516.6
5.26
99.00
I-D
503.25/502.6
5.10
98.12
I-E
503.20/502.6
5.83
97.15
I-F
503.25/502.6
6.70
99.08
I-G
503.25/502.6
5.87
98.71
I-H
503.26/502.6
6.23
98.79
I-J
503.30/502.6
4.80
100.0
I-K
503.27/502.6
4.65
97.44
I-L
542.1/541.6
4.72
99.47
I-M
519.3/518.6
5.81
100.0
I-N
575.3/574.7
7.25
98.43
I-O
517.3/516.6
6.52
97.05
I-P
MS + Na + = 541.47,
9.15
99.00
MS + K + = 557.44/
(C-8 Kromasil col.,
518.25
gradient 40-80%
B in 15 min)
Example 2
Therapeutic Efficacy of the Peptide as a 0.1% Ointment in the Model of Contact Sensitivity to Oxazolone in BALB/c Mice
[0116] The aim of this experiment was to verify the therapeutic action of compound I-A and its toxicity in a generally accepted animal model. In the experiment described below, the compound of formula I-A was applied as a therapeutic preparation in the form of 0.1% wt/wt ointment based on a commonly used pharmaceutical vehicle, namely an ointment composed of 50% vaseline and 50% lanoline. The usefulness of the preparation in reduction of the effector phase of the contact sensitivity to oxazolone in mice, in comparison with reference preparations such as tacrolimus (Protopic®) and pimecrolimus (Elidel®), widely used for treatment of skin diseases, was studied.
Materials and Methods
[0117] Mice: BALB/c female mice, 8-10 week-old, delivered by the Institute of Laboratory Medicine, ódź, Poland, were used for the study. The mice were fed a commercial, pelleted food and water ad libitum. The local ethics committee approved the study.
[0118] Reagents: Water-in-oil cream and ointment were delivered by Nepentes. Cyclic tetrapeptide (compound I-A) was synthesized as described above. Protopic® (tacrolimus) was purchased from Astellas, Ireland; Elidel® (pimecrolimus) was purchased from Novartis; Hydrocortisonum® (hydrocortisone) was purchased from Aflofarm Farmacja Polska, Poland. DMSO was obtained from Fluka; oxazolone, acetone, Evans blue, Giemsa, May-Grünwald, and formalin were from Sigma.
[0119] Contact Sensitivity to Oxazolone:
[0120] The test was performed according to Noonan et al. ( Int. Arch. Allergy Appl. Immunol., 1978, 56, 523-532), with some modifications. Mice were shaved on the abdomen (2×2 cm area) and after 24 h 100 μl of 0.5% oxazolone in acetone was applied to the shaved area. The contact sensitivity reaction was elicited 5 days later by application of 50 μl of 1% oxazolone in acetone on both sides of the ears. Ear edema was measured 48 h later using a spring caliper. The results were presented as antigen-specific increase of ear thickness (i.e. the background (BG) ear thickness of mice was subtracted from the measured thickness).
[0121] Application of Compounds:
[0122] In the experiment shown, the compound of formula I-A was applied topically as a 0.1% ointment on both sides of the ears (total volume of 50 μl per ear), at 24 h and 26 h after elicitation of the reaction with the second dose of oxazolone. Reference compounds were used in a similar fashion in the form of commercially available preparations.
[0123] Determination of Lymph Node Cell Numbers:
[0124] Superficial parotid, mandibular and accessory mandibular lymph nodes were isolated, homogenized by pressing against a stainless screen into phosphate buffered solution (PBS), washed twice and re-suspended in PBS containing 0.2% Trypan blue. The total and nonviable cell numbers were determined using a light microscope and Bürker's hemocytometer. Mice treated only with the eliciting dose of antigen served as a background control.
[0125] Determination of Circulating Leukocyte Number and Blood Picture:
[0126] Mice were subjected to halothane anesthesia and bled from the retro-orbital plexus, followed by cervical dislocation. The number of blood leukocytes was determined by dilution of blood in Türk's solution and counting the cells in a hemocytometer. Blood smears were prepared on microscope glass, dried and stained with Giemsa and May-Grünwald reagents. The smears were subsequently reviewed histologically. The circulating leukocyte numbers were presented per 1 mm 3 and the blood cell compositions as a percentage of a given cell type. Mice treated only with the eliciting dose of antigen served as a background control.
[0127] Histological Analysis:
[0128] The auricles were fixed in 4% formalin solution for 48 h, washed for 24 h, dehydrated in an alcohol series and embedded in paraffin. The paraffin blocks were sliced in a Micron HM310 microtome into 6 μm sections. The sections were stained with haematoxylin and eosin and with toluidine blue. The histological analysis was performed in a Nikon Eclipse 801 light microscope. On the histological slides containing cross-sections of auricles, the morphometric estimations of neutrophils, macrophages, lymphocytes and mast cells in the perivascular and subepithelial connective tissue were performed. The cells were counted on the area of 0.07 mm 2 at 400× magnification. Morphometric analysis was done with the aid of imagine software NIS-Elements (Nikon). For every examined group, 25 enumerations of neutrophils, macrophages, lymphocytes and mast cells were carried out.
[0129] Statistics:
[0130] The results are presented as mean values±standard error (SE). Brown-Forsyth's test was used to determine the homogeneity of variance between groups. When the variance was homogenous, analysis of variance (one-way ANOVA) was applied, followed by post hoc comparisons with the Tukey's test to estimate the significance of the differences between groups. Nonparametric data were evaluated with the Kruskal-Wallis' analysis of variance, as indicated in the text. Significance was determined at p<0.05. Statistical analysis was performed using STATISTICA 7 for Windows. The statistical analysis applies to all data shown in this description.
Results:
[0131] The data included in FIG. 1 show the therapeutic efficacy of compound of formula I-A (labeled “4B8M” in FIG. 1 and subsequent figures) and the reference preparations in mice with fully developed contact sensitivity reaction to oxazolone. The preparations were applied topically as described in the Methods. FIG. 1 presents only antigen-specific increases of the ear thickness (as a result of subtracting background values measured in non-sensitized mice which were given only the eliciting dose of antigen). Compound I-A caused about 80% inhibition of the ear edema; Protopic® and Elidel® respectively caused about 30% and 50% inhibition.
[0132] The intensity of inflammatory processes in the ears should correlate with cell numbers in the draining lymph nodes. Therefore, inhibition of inflammation should be associated with a decrease of cell number in the draining lymph nodes. FIG. 2 shows that both the compound of formula I-A as well as Elidel® decreased the numbers of lymphocytes in the draining lymph nodes to the level registered in non-sensitized mice. However, in mice treated with Protopic® the number of lymph node cells was similar to that in untreated mice.
[0133] FIG. 3 shows the proportions of viable and dead cells in the draining lymph nodes, expressed in percentages. The compound of formula I-A exhibits a negligible toxic effect as compared to the control, non-treated mice. A higher toxic effect is caused by Elidel®, and Protopic® is exceptionally toxic with regard to lymph node cells.
[0134] Complementary information regarding the therapeutic efficacy of the preparations may be derived from histological analysis of the cell number and composition in the inflamed auricles. FIG. 4 depicts the numbers and participation of basic cell types involved in the local inflammatory process. In FIG. 4 , Mast=mastocytes, L=lymphocytes, MØ=macrophages, Ne=neutrophils. The auricles from untreated mice (K+) are characterized by a high infiltration of neutrophils. Application of the compound of formula I-A almost entirely reversed the changes observed in control mice (normalization of neutrophil number with some increase in the macrophage content). Protopic®, in turn, caused some changes in the proportion of respective cell types with no reduction of the total cell infiltrate. Elidel® caused a moderate diminution of the total cell number.
Example 3
The Toxicity of Compound I-A Versus that of Cyclolinopeptide Against Human Blood Mononuclear Cells
[0135] For evaluation of toxicity of the compound of formula I-A, human peripheral mononuclear blood cells (PBMC) were chosen. This fraction consists of approximately 80% lymphocytes and 20% monocytes. As a reference compound, cyclolinopeptide (CLA) was selected since the compound of formula I-A shares a part of the sequence of CLA. CLA exhibits immunosuppressive properties comparable to that of cyclosporine A, but is less toxic.
Materials and Methods
[0136] The Cytotoxic Test:
[0137] Venous blood from a single donor was taken into heparinized syringes, diluted twice with phosphate buffered saline (PBS) and applied onto Lymphoprep® (Polfa, Kutno, Poland) (density of 1.077 g/ml). After centrifugation at 1200×g for 20 min, the mononuclear cells from the interphase were harvested and washed 3 times with PBS. The cells were re-suspended in a standard culture medium consisting of RPMI-1640 medium, L-glutamine, sodium pyruvate, 2-mercaptoethanol, 100 μg/ml each of streptomycin and penicillin, and 10% fetal calf serum. The cells were distributed to in 96-well flat-bottom culture plates at density of 2×10 5 /100 μl. The compounds (formula I-A and CLA) were initially dissolved in DMSO (5 mg/500 μl) and subsequently in the culture medium. DMSO, appropriately diluted with the culture medium, was used as a control. After 24 h incubation in a cell culture incubator, cell viability was determined by a colorimetric method (Hansen et al., J Immunol Methods, 1989, 119, 203-210).
[0138] The results are shown in FIG. 5 , presented as mean optical density values from quadruplicate wells (cell cultures)±SE. As can be seen in FIG. 5 , the compound of formula I-A (listed as “4B8M”) did not show appreciable toxicity in the concentration range of 10 to 100 μg/ml. CLA, on the other hand, showed a statistically significant cytotoxic effect at 40 μg/ml.
Example 4
Effect of Peptide on the Humoral Immune Response to SRBC In Vivo
[0139] CBA female mice, 8-12 weeks old, were delivered by The Institute of Laboratory Medicine, ódź, Poland. The mice had free access to water and pelleted food. The local ethics committee approved the study. Sheep erythrocytes (SRBC) were delivered by Wroclaw University of Life and Environmental Sciences, Poland, and maintained on RPMI-1640 medium.
[0140] The Primary Humoral Immune Response to SRBC In Vivo:
[0141] Mice were immunized with 0.2 ml of 5% SRBC suspension (0.5 ml of SRBC pellet re-suspended to a volume of 10 ml of 0.9% NaCl), intraperitonelly. After 4 days the number of antibody-forming cells (AFC) in the spleens was determined using an assay of local hemolysis in agar gel (per Mishell et al., J Exp Med, 1967, 126, 423-442). The results are presented in FIG. 6 as a mean value of 5 mice±standard error and expressed as AFC number per 10 6 of viable splenocytes.
[0142] Mice were immunized with SRBC as described above and after 2 h were given 10 or 100 μg of the compound of formula I-A. Cyclosporin A (CsA) served as a reference drug. The number of antibody-forming cells to SRBC was measured after 4 days. As shown in FIG. 6 , the compound of formula IA was more inhibitory at both doses than CsA.
Example 5
Effect of Peptide on the Cellular Immune Response In Vivo to Ovalbumin
[0143] Male CBA mice 8-12 weeks old were delivered by The Institute of Laboratory Medicine, ódź, Poland. The mice had free access to water and pelleted food. Ovoalbumin was from Sigma and the adjuvants from Difco.
[0144] Delayed Type Hypersensitivity (DTH) Test:
[0145] Mice were sensitized subcutaneously with 5 μg of ovalbumin (OVA) emulsified in Freund's complete adjuvant in the tail base. After 4 days the mice were challenged with 50 μg of OVA in Freund's incomplete adjuvant in the hind footpads. Following the next 24 hours, the footpad thickness was measured using a caliper. Controls (background response mice) were not sensitized but received the challenging dose of OVA. The compound of formula I-A and the reference compound were administered to mice in two 100 μg intraperitoneal doses, 2 h before and 24 h after the sensitizing dose of antigen. The results, presented in FIG. 7 as a mean value of antigen-specific increase of footpad thickness measured in 5 mice and expressed in DTH units (one DTH unit=10 −2 cm)±standard error, show that the compound of formula I-A, given in two doses, 2 h and 24 h after immunization, inhibited the delayed-type hypersensitivity reaction to OVA. That suppressive action was stronger than those of CLA and CsA.
Example 6
[0146] Cyclic tetrapeptides were tested in vitro for their effects on phytohemagglutinin A (PHA)-induced proliferation of human peripheral blood mononuclear cells (PBMC) and for lipopolysaccharide (LPS)-induced production of tumor necrosis factor alpha (TNF-α) production by whole blood cell cultures at 1-100 μg/ml concentration range. Compounds were also tested for cell toxicity at 1-100 μg/ml concentration range against human PBMC.
Materials and Methods:
[0147] Reagents:
[0148] RPMI-1640 medium (Cibi/Life Technologies, UK), fetal calf serum (FCS, Gibco), DMSO, phytohemagglutinin A (PHA), lipopolysaccharide (LPS) from E. coli strain 0111:B4 (Sigma), 93-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), SDS and DMF (Sigma). The culture medium consisted of RPMI-1640, 10% addition of FCS, L-glutamine, sodium pyruvate, 2-mercaptoetanol and antibiotics (streptomycin and penicillin). Cyclic tetrapeptides were initially dissolved in DMSO (5 mg/ml), the dissolved in the culture medium to the desired concentration.
[0149] Isolation of PBMC:
[0150] Venous blood was taken from a single donor (a male, 62-years old) into heparinized syringes and diluted twice with phosphate-buffered saline (PBS). PBMC were isolated by centrifugation on Ficoll-uropoline gradient (density 1.077 g/ml) (Lymphoprep; PAA Laboratories), at 800×g for 20 min at 4° C. The interphase cells, consisting of lymphocytes (20%) and monocytes (80%) were then washed three times with Hanks' medium and re-suspended in the culture medium at density of 2×10 6 cells/ml.
[0151] The Proliferative Response of PBMC to PHA:
[0152] The isolated PBMC were distributed into 96-well flat-bottom plates in 100 μl aliquots (2×10 5 cells/well). PHA was used at concentration of 5 μg/ml. The compounds were tested at concentrations of 1, 10 and 100 μg/ml. DMSO at appropriate dilutions served as control. After a four-day incubation in a cell culture incubator, the proliferative response of cells was determined by the colorimetric MTT method (Hansen et al., J. Immunol. Methods, 1989, pp. 203-210). The data are presented as a mean OD value from quadriplicate wells±standard error (SE). The cultures “Control (−)” contained no mitogen (PHA). The cultures “Control (PHA)” contained PHA but not cyclic tetrapeptides.
[0153] Toxicity Test:
[0154] PBMC, at a density of 2×10 5 /100 μl/well, re-suspended in the culture medium, were cultured for 24 h in a cell culture incubator with the cyclic tetrapeptides at concentrations of 1, 10 and 100 μg/ml concentrations. Cell survival was determined by the MTT colorimetric method (Hansen et al., J. Immunol. Methods, 1989, pp. 203-210). The data are presented as a mean OD value from quadriplicate wells±standard error (SE). The cultures “Control (−)” contained only cells in the culture medium.
[0155] The Determination of TNF Alpha Activity (Per Espevik et al., J. Immunol. Methods, 95 (1986):99-103):
[0156] Human whole blood was diluted 10-fold with RPMI-1640 medium and distributed to 24-well culture plates in 1 ml aliquots. LPS was added to the culture at a concentration of 1 μg/ml. The studied peptides were used at concentrations of 1, 10 and 100 μg/ml. After overnight incubation, the supernatants were harvested and frozen at −20° C. until cytokine determination. TNF-α activity was determined using a bioassay. Briefly, WEHI 164.13 cells (ATCC CRL 1751) were seeded at a concentration of 2×10 4 cells/well in quadriplicate. Increasing dilutions of the assayed supernatant were mixed with the target cells in the presence of actinomycin D (1 μg/ml). After 20 h of incubation, MTT was added into the wells, and the cultures were incubated for an additional 4 h. Next, a lysing buffer (20% SDS with 50% DMF, pH 4.7) was added and the optical density at 550 nm with the reference wavelength of 630 nm in a Dynatech 5000 spectrophotometer was measured after 24 h. The detection limit of the assay was about 2.5 pg/ml. One unit of TNF-α activity was defined as an inverse of supernatant dilution where 50% cell death took place. The cultures labeled “Control (−)” contained no LPS. The cultures labeled “Control (LPS)” contained LPS and none of the studied compounds. Statistical analysis was not applied since the data derive from single cultures (wells).
[0157] Colorimetric MTT Assay for Cell Growth and Kill:
[0158] The assay was performed per Hansen et al., J. Immunol. Methods, 1989, 119 pp. 203-210. Briefly, 25 μl of MTT (5 mg/ml) stock solution was added per well at the end of cell incubation and the plates were incubated for 3 h in a cell culture incubator. Then, 100 μl of the extraction buffer (20% SDS with 50% DMF, pH 4.7) was added. After additional overnight incubation, the optical density was measured at 550 nm (Dynatech 5000).
[0159] Where applicable, results are presented as mean values±standard error (SE). Brown-Forsyth's test was used to determine the homogeneity of variance between groups. When the variance was homogenous, analysis of variance (one-way ANOVA) was applied, followed by post hoc comparisons with the Tukey's test to estimate the significance of the differences between groups. Significance was determined at P<0.05. Statistical analysis was performed using STATISTICA 6.1 for Windows.
Results
[0160] Effects of the Compounds on Survival of PBMC:
[0161] The effects of the peptides on PMBC survival in 24 h culture are presented in FIGS. 8A and 8B . Peptide 4B8M (compound I-A) was included as a reference compound. Appropriate dilutions of DMSO were added to control cultures. The results showed no signs of toxicity of the compounds in the studied concentration range. In the figures, P01=compound I-D, P02=compound I-E, P03=compound I-F, P04=compound I-G, P05=compound I-H, P06=compound I-J, P07=compound I-K, P08=compound I-L, P10a=compound I-M, P10b=compound I-N, and P11=compound I-O.
[0162] FIGS. 8A and 8B show the effects of the tested peptides on the survival of PBMC. FIG. 8A : Statistics (all comparisons vs. DMSO at appropriate dilutions): 100 μg/ml: 4B8M NS (P=0.9999); P01 NS (P=1.0000); P02 NS (P=1.0000); P03 NS (P=1.0000); P04 NS (P=0.9047); P05 NS (P=1.0000); P06 NS (P=0.9999); P07 NS (P=1.0000); 4B8M NS (P=1.0000); P01 NS (P=1.0000); P02 NS (P=1.0000); P03 NS (P=1.0000); P04 NS (P=0.9999); P05 NS (P=1.0000); P06 NS (P=1.0000); P07 NS (P=1.0000); 1 μg/ml: 4B8M NS (P=1.0000); P01 NS (P=1.0000); P02 NS (P=1.0000); P03 NS (P=1.0000); P04 NS (P=1.0000); P05 NS (P=1.0000); P06 NS (P=0.8253); P07 NS (P=1.0000) (ANOVA). FIG. 8B : Statistics (all comparisons vs. DMSO at appropriate dilutions): 100 μg/ml: 4B8M NS (P=0.0669); P08 NS (P=0.9957); P10b NS (P=1.0000); 10 μg/ml: 4B8M NS (P=0.9999); P08 NS (P=1.0000); P10b NS (P=1.0000); 1 μg/ml: 4B8M NS (P=0.3176); P08 NS (P=0.9999); P10b NS (P=1.0000) (ANOVA).
[0163] Effects of the Peptides on PHA-Induced PMBC Proliferation:
[0164] The effects of the peptides on the proliferative response of PMBC are presented in FIGS. 9A and 9B . Peptide 4B8M was included as a reference compound. Appropriate dilutions of DMSO were added to control cultures.
[0165] FIG. 9A : Effects of the peptides on PHA-induced PBMC proliferation: Statistics (all comparisons vs. DMSO at appropriate dilutions): 1 μg/ml: 4B8M NS (P=0.9995); P01 NS (P=1.0000); P02 NS (P=1.0000); P03 NS (P=1.0000); P04 NS (P=0.9047); P05 NS (P=0.5198); P06 NS (P=1.0000); P07 NS (P=0.1445); 10 μg/ml: 4B8M NS (P=1.0000); P01 NS (P=0.9999); P02 NS (P=1.0000); P03 NS (P=0.9930); P04 NS (P=0.4297); P05 NS (P=1.0000); P06 NS (P=1.0000); P07 NS (P=0.8647); 100 μg/ml: 4B8M NS (P=1.0000); P01 NS (P=1.0000); P02 NS (P=0.9982); P03 P=0.0001; P04 NS (P=0.9970); P05 NS (P=0.2037); P06 NS (P=0.1257); P07 NS (P=1.0000) (ANOVA).
[0166] FIG. 9B : Effects of the peptides on PHA-induced PBMC proliferation: Statistics (all comparisons vs. DMSO at appropriate dilutions): 1 μg/ml: 4B8M NS (P=0.9919); P08 NS (P=0.9999); P10b NS (P=1.0000); 10 μg/ml: 4B8M NS (P=1.0000); P08 NS (P=1.0000); P10b NS (P=0.2763); 100 μg/ml: 4B8M NS (P=0.4941); P08 NS (P=1.0000); P10b NS (P=0.9933) (ANOVA).
[0167] Effects of the Peptides on LPS-Induced TNF-α Production in Whole Blood Cell Cultures:
[0168] The effects of the peptides on LPS-induced TNF-α production in whole blood cell cultures are presented in Tables 2A and 2B. Peptide 4B8M was included as a reference compound. Appropriate dilutions of DMSO were added to control cultures.
[0000]
TABLE 2A
Effects of peptides on LPS-induced TNF-α production
compound
concentration
TNF-α
% inhibition
Compound
(μg/ml)
(pg/ml)
vs. DMSO
Control (—)
—
92
—
Control (LPS)
—
6668
—
DMSO
1
8167
—
Only
10
8006
—
100
196
—
4B8M
1
7364
9.8
(compound I-A)
10
7176
10.4
100
178
9.2
P01
1
7016
14.1
(compound I-D)
10
5757
28.1
100
141
28.1
P02
1
6614
19.0
(compound I-E)
10
6346
20.7
100
176
10.2
P03
1
6052
25.9
(compound I-F)
10
5222
34.8
100
76
61.2
P04
1
5463
33.1
(compound I-G)
10
5302
33.8
100
58
70.4
P05
1
7123
12.8
(compound I-H)
10
7203
10.0
100
110
43.9
P06
1
8033
1.6
(compound I-J)
10
7658
4.4
100
203
0.0
P07
1
6453
21.0
(compound I-L)
10
7284
9.0
100
163
16.8
[0000]
TABLE 2B
Effects of the peptides on LPS-induced TNF alpha production
compound
% of
concentration
TNF alpha
inhibition
Compound
(μg/ml)
(pg/ml)
vs. DMSO
Control (—)
—
223
—
Control (LPS)
—
4260
—
DMSO
1
4550
—
Only
10
4351
—
100
854
—
4B8M
1
4097
10.0
(compound I-A)
10
4416
—
100
979
—
P08
1
4039
11.2
(compound I-M)
10
3363
22.7
100
269
68.5
P10b
1
3792
16.7
(compound I-O)
10
3739
14.0
100
282
67.0
Example 7
Inhibitory Effect of Compound I-A on Toluene Diisocyanate-Induced Ear Inflammation in Mice
[0169] The efficacy of the compound I-A in suppressing ear inflammation in BALB/c mice which was induced with toluene diisocyanate (TDI). Commercially available Protopic® (tacrolimus) and Elidel® (pimecrolimus) served as reference drugs.
Materials and Methods
[0170] Mice:
[0171] BALB/c female mice, 8-10 weeks old, were delivered by the Institute of Laboratory Medicine, ódź, Poland. The mice were fed a commercial, pelleted food and water ad libitum. The local ethics committee approved the study.
[0172] Reagents.
[0173] Compound I-A was synthesized as described above; Protopic® (tacrolimus) was from Astellas, Ireland; Elidel® (pimecrolimus) from Novartis; DMSO from Fluka; TDI, acetone, Evans blue, Trypan blue, Giemsa, May-Grünwald, haematoxylin, eosin, toluidine blue and formalin were from Sigma.
[0174] Immune Response to TDI.
[0175] The test was performed according to Yamamoto, Eur. J. Pharmacol., 2006, 550, 166-172, with minor modifications. Mice were shaved on the abdomen (2×2 cm area) and after 24 h 100 μl of 3% TDI in acetone was applied through 3 consecutive days. After 14 days the reaction was elicited by application of 50 μl of 0.3% TDI on both sides of the ears. The procedure was repeated 5 times every 3 days. Ear thickness was measured using a spring caliper (Mitutoyo) 5 h and 24 h after each challenge with TDI.
[0176] Application of Compounds.
[0177] Compound I-A was applied topically in the form of 0.1% ointment on both sides of the ears (total volume of 100 μl−50 μl per ear), one hour after each challenge with TDI. The reference drugs were applied in a similar way.
[0178] Determination of Lymph Node Cell Numbers.
[0179] Superficial parotid, mandibular and accessory mandibular lymph nodes were isolated, homogenized by pressing against a stainless screen into PBS, washed 2× with PBS and re-suspended in PBS containing 0.2% Trypan blue. The total and nonviable cell numbers were counted using a light microscope and Bürker's hemocytometer.
[0180] Determination of Circulating Leukocyte Number and Blood Picture.
[0181] Mice were subjected to halothane anesthesia and bled from the retro-orbital plexus, followed by the cervical dislocation. The number of blood leukocytes was determined by dilution of blood in Türk's solution and counting the cells in a hemocytometer. Blood smears were prepared on microscope glass, dried and stained with Giemsa and May-Grünwald reagents. The smears were subsequently reviewed histologically. The cell numbers were presented per 1 μl and the blood cell compositions as a percentage of a given cell type.
[0182] Evans Blue Test.
[0183] Mice were given 1 mg of Evans blue in 0.2 ml of 0.9% NaCl, intravenously. After 30 min mice were sacrificed, the ears were cut off, weighed and immersed in 50 μl of 1M KOH for 18 h at 37° C. The dye was extracted from the ears using 450 μl of 0.2 M phosphate acid and acetone (5:13 ratio). The samples were centrifuged at 3,000 rpm for 15 min. The optical densities (OD) of the supernatants were measured at 630 nm. The amount of Evans blue (μg/ml) was determined based on a standard curve. The results were presented as the amount of Evans blue per 100 mg of wet tissue. Mice treated only with the eliciting dose of antigen served as a background control.
[0184] Histological Analysis.
[0185] The auricles were fixed in 4% formalin solution for 48 h, washed for 24 h, dehydrated in an alcohol series and embedded in paraffin. The paraffin blocks were sliced in a Micron HM310 microtome into 6 μm sections. The sections were stained with haematoxylin and eosin and with toluidine blue. Histological analysis was performed using a Nikon Eclipse 801light microscope. Morphometric estimations of neutrophils, macrophages, lymphocytes and mast cells in the perivascular and subepithelial connective tissue were performed on the histological slides containing cross-sections of auricles. Cells were counted on an area of 0.07 mm 2 at 400× magnification. Morphometric analysis was performed using an imagine software NIS-Elements (Nikon). For every preparation examined, 25 enumerations of neutrophils, macrophages, lymphocytes and mast cells were carried out.
[0186] Statistics.
[0187] The results in FIGS. 10A and 10B are presented as mean values±standard error (SE). Brown-Forsyth's test was used to determine the homogeneity of variance between the groups. When the variance was homogenous, analysis of variance (one-way ANOVA) was applied, followed by post hoc comparisons with the Tukey's test to estimate the significance of the differences between groups. Nonparametric data were evaluated with the Kruskal-Wallis' analysis of variance, as indicated in the text. Significance was determined at P<0.05. Statistical analysis was performed using STATISTICA 7 for Windows.
Results
[0188] Effects of the Compounds on the Ear Thickness.
[0189] The humoral immune response to TDI was elicited as described in the Methods. Mice were treated topically with the tetrapeptide (formula I-A, labeled 4B8M in FIGS. 10A and 10B ) and the reference compounds one hour after each challenge with antigen. The effects of the treatments are presented in FIGS. 10A and 10B , which show ear thickness measure 5 h ( FIG. 10A ) and 24 h ( FIG. 10B ) after administration on the day of the test indicated in the figure. Control responses to TDI gradually elevated after each antigen challenge (best seen in the 5 h measurement). The results showed differentiated efficacy of the compounds in reducing the ear swelling.
[0190] FIG. 10A : Day 14: Control vs 4B8M P=0.0005; Control vs Protopic® P=0.0002; Control vs Elidel® P=0.0152; 4B8M vs Protopic® NS; 4B8M vs Elidel® NS; Day 17: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0377; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0002; Day 20: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® NS; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0001; Day 23: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® NS; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0001; Day 27: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0001; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0001 (ANOVA). FIG. 10B : Day 14: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0004; 4B8M vs Protopic® NS; 4B8M vs Elidel® NS; Day 17: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0023; Control vs Elidel® P=0.0004; 4B8M vs Protopic® NS; 4B8M vs Elidel® NS; Day 20: Control vs 4B8M P=0.0006; Control vs Protopic® P=0.0003; Control vs Elidel® P=0.0156; 4B8M vs Protopic® NS; 4B8M vs Elidel® NS; Day 23: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0039; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0027; Day 27: Control vs 4B8M P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0023; 4B8M vs Protopic® NS; 4B8M vs Elidel® P=0.0016 (ANOVA).
[0191] Effects of the Compounds on Permeability of Skin Vessels:
[0192] The permeability of capillary blood vessels is presented in FIG. 11 , which shows the permeability of capillary blood vessels in the Evans blue test. The procedure, as described aboved, was performed 24 h after the fifth challenge with TDI (on day 28). As shown in the FIG. 11 , the rates of blood vessel permeability were strictly correlated with the effects of the compounds on ear thickness in the respective mouse groups. Statistics: BG vs Control P=0.0248; Control vs 4B8M (I-A) P=0.030; Control vs Protopic® NS; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® NS; 4B8M (I-A) vs Elidel® NS (ANOVA).
[0193] Effects of the Compounds on Number of Cells in Draining Lymph Nodes:
[0194] FIG. 12 shows the total number of cells in the draining lymph nodes. As shown in FIG. 12 , the treatment of mice with compound I-A resulted in a reduction of the lymph node cell numbers almost to the background levels (non-sensitized mice). Statistics: BG vs Control P=0.0001; Control vs 4B8M (I-A) P=0.0001; Control vs Protopic® NS; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® P=0.0183; 4B8M (I-A) vs Elidel® P=0.0001 (ANOVA of Kruskal-Wallis).
[0195] Effects of the Compounds on the Numbers of Circulating Leukocytes.
[0196] FIG. 13 shows the effects of the compounds on the numbers of circulating leukocytes; the application of the studied preparations lowered the numbers of circulating leukocytes to the levels observed in control, unsensitized mice. Statistics: BG vs Control P=0.0001; Control vs 4B8M (I-A) P=0.0001; Control vs Protopic® P=0.0001; Control vs Elidel® P=0.0001; 4B8M (I-A) vs Protopic® NS; 4B8M (I-A) vs Elidel® NS (ANOVA).
[0197] Effects of Compounds on Blood Cell Composition:
[0198] The blood composition in control mice with fully developed reaction to TDI was characterized by an increased content of neutrophils and eosinophils compared to control, background mice ( FIG. 14 , which shows a breakdown of the types of leukocytes in each case). The blood picture was normalized upon application of 4B8M (I-A) (a reduction of neutrophil and eosinophil contents) but not following administration of Protopic® or Elidel®. Statistics: Bands (B): BG vs Control NS; Control vs 4B8M (I-A) NS; Control vs Protopic® P=0.0500; Control vs Elidel® P=0.0500; 4B8M (I-A) vs Protopic® NS; 4B8M vs Elidel® NS (ANOVA of Kruskal-Wallis); Segments (S): BG vs Control P=0.0131; Control vs 4B8M (I-A) NS; Control vs Protopic® NS; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® P=0.0163; 4B8M (I-A) vs Elidel® NS (ANOVA of Kruskal-Wallis); Eosinophils (E): BG vs Control P=0.0001; Control vs 4B8M (I-A) P=0.0001; Control vs Protopic® NS; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® NS; 4B8M vs Elidel® P=0.0146 (ANOVA of Kruskal-Wallis); Lymphocytes (L): BG vs Control P=0.0001; Control vs 4B8M (I-A) P=0.0043; Control vs Protopic® NS; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® P=0.0345; 4B8M (I-A) vs Elidel® NS (ANOVA of Kruskal-Wallis).
[0199] The Effects of the Compounds on Cell Composition in the Auricles:
[0200] FIG. 15 provides morphometric data on the number and composition of cells in the auricles. The composition of cell types within the auricles differed among the studied mouse groups is presented in FIG. 15 . The predominant, residing cell types in control non-sensitized mice are mastocytes and neutrofils (10 and 5 cells per the analyzed area, respectively). In sensitized, control mice, untreated with the therapeutics, the number of mastocytes increased twofold and neutrophils almost 5-fold (20 and 23 cells, respectively). Protopic® and Compound I-A were effective in reducing the cell numbers to 14 and 14.8. Statistics: Ne (neutrophils): BG vs Control P=0.0001; Control vs 4B8M (I-A) P=0.0151; Control vs Protopic® P=0.0001; Control vs Elidel® NS; 4B8M vs Protopic® NS; 4B8M (I-A) vs Elidel® P=0.0003 (ANOVA of Kruskal-Wallis); MØ (macrophages): BG vs Control P=0.0144; Control vs 4B8M (I-A) NS; Control vs Protopic® NS; Control vs Elidel® P=0.0255; 4B8M vs Protopic® NS; 4B8M (I-A) vs Elidel® P=0.0031 (ANOVA of Kruskal-Wallis); L (lymphocytes): BG vs Control NS; Control vs 4B8M (I-A) NS; Control vs Protopic® NS; Control vs Elidel® P=0.0023; 4B8M vs Protopic® NS; 4B8M (I-A) vs Elidel® P=0.0001 (Anova of Kruskal-Wallis); Mast (mastocytes): BG vs Control P=0.0001; Control vs 4B8M (I-A) NS; Control vs Protopic® P=0.0001; Control vs Elidel® NS; 4B8M (I-A) vs Protopic® NS; 4B8M (I-A) vs Elidel® P=0.0001 (ANOVA of Kruskal-Wallis).
Example 8
In Vitro Tests of Compounds I-B and I-C
Methods
[0201] Proliferative Response of Splenocytes to Concanavalin A (ConA):
[0202] Spleens were pressed against a plastic screen into 0.83% NH 4 Cl solution to lyse erythrocytes (5 min incubation at room temperature). The cells were then washed twice with Hanks' medium, passed through glass wool column to remove debris, and re-suspended in the culture medium, referred to below as the “culture medium”, consisting of RPMI-1640, supplemented with 10% of fetal calf serum, L-glutamine, sodium pyruvate, 2-mercaptoethanol, streptomycin and penicillin (100 μg/ml). The cells were then distributed into 96-well flat-bottom tissue culture plates (Nunc) at a density of 2×10 5 cells/100 μl/well. Con A (2.5 μg/ml) was added to induce cell proliferation. The compounds were added to the cultures at doses of 1-100 μg/ml. After a three-day incubation, cell proliferation was determined using the colorimetric MTT method (Hansen M B, J Immunol Methods, 1989, 119, 203-210). The results were presented as the mean optical density (OD) at 550 nm±SE from quadriplicate determinations (wells).
[0203] Secondary Humoral Immune Response In Vitro to Sheep Erythrocytes (SRBC):
[0204] Mice were sensitized intraperitoneally with 0.2 ml of 5% (v/v) SRBC suspension. After four days spleens from these mice were isolated and single cell suspensions prepared by homogenization in PBS solution. After washing the cells in PBS by centrifugation, the cells were re-suspended in the culture medium at a density of 5×10 6 cells/ml. The cells were subsequently distributed to 24-well culture plates in 1 ml aliquots and 0.05 ml of 0.005% SRBC was added as the antigen to each well. The compounds were added to the cultures at the beginning of the four-day incubation period at concentration ranges of 1-100 μg/ml. The number of antibody-forming cells (AFC) in the cultures was determined using a method of local hemolysis in agar gel according to Mishell et al., J Exp Med, 1967, 126, 423-442.
[0205] Toxicity Test:
[0206] Splenocytes, at a density of 2×10 5 cells/100 μl/well, re-suspended in the culture medium, were cultured for 24 h in a cell culture incubator with the compounds (1-100 μg/ml). Cell survival was determined by MTT colorimetric method. The results were presented as mean optical density (OD) at 550 nm from 4 wells. The viability of cells in respective compound concentrations was compared to appropriate DMSO control groups (100% survival), corresponding to respective compound concentrations.
Results
[0207] At 50-100 μg/ml concentrations, compound I-C showed a strong inhibitory effect on concanavalin A-induced mouse splenocyte proliferation. At 100 μg/m, this compound showed 70% toxicity to splenocytes. At 10 μg/m and 100 μg/m, compound I-C showed 33% and 80% suppression, respectively, in the model of in vitro humoral immune response to SRBC in mouse splenocyte cultures. In the model of delayed type hypersensitivity to ovalbumin, compound I-C showed 26.9% inhibition at the dose of 100 μg, compared to 72.7% inhibition by compound I-A.
[0208] At 100 μg/ml concentration, compound I-B demonstrated a weak antiproliferative effect on concanavalin A-induced splenocyte proliferation; no such effect was observed at lower concentrations. Compound I-B had 30% toxicity at this concentration.
[0209] Although the foregoing invention has been described in some detail for purposes of illustration, it will be readily apparent to one skilled in the art that changes and modifications may be made without departing from the scope of the invention described herein. | There are provided compounds of formula I wherein k, m, n, p, R, R′, R″, R′″, R3 and R4 are as defined in the application. Other embodiments are also disclosed. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a karaoke system, and more particularly to a karaoke system wherein music for a karaoke performance is incorporated in a story.
The term “karaoke” is generally defined to be “a form of entertainment, offered typically at bars or clubs, in which people take turns to sing popular songs into a microphone over pre-recorded backing tracks” (The New Oxford Dictionary of English published by Oxford University Press in 1998).
Recently, karaoke has constituted one of most popular amusements without distinction of age and sex and gained a firm position in the industrial world. Thus, karaoke equipment manufacturers have a fierce competition with others in order to permit their own karaoke system to be advantageously differentiated from those of other manufacturers. For this purpose, each of the manufacturers devotes itself to addition of any significant value to its own karaoke system. For example, it is proposed that a karaoke system is provided with a marking function. More particularly, a karaoke system is proposed which is constructed so as to make a variety of developments depending on results of marking obtained by the marking function.
However, such a marking function becomes old-fashioned nowadays, thus, the marking function fails to make a differentiation between karaoke systems. Also, the conventional karaoke systems were mainly developed for adults including students, resulting in them failing to be applied to children and/or youths.
SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing disadvantage of the prior art.
Accordingly, it is an object of the present invention to provide a karaoke system which is capable of creating significant value added.
It is another object of the present invention to provide a karaoke system which can be conveniently used by children and/or youths.
In accordance with the present invention, a karaoke system is provided. The karaoke system generally includes a main unit operatively connectable to a display unit through a wire or by wireless. The main unit feeds the display unit with image data for displaying words of a music piece on the display unit and music data for playing accompaniment music of the music piece, thereby a karaoke performance being carried out according to the words displayed on the display unit and the accompaniment music outputted from the display unit. The karaoke system generally constructed as described above is featured in that the main unit is constructed so as to permit the display unit to display images constituting at least one story in order and so as to output words and accompaniment music of a music piece associated with the story to the display unit during the course of the story.
In a preferred embodiment of the present invention, the story may be constructed so as to progress while being ramified into a plurality of branches. The branches are set so as to permit a user to select the branches as desired and each have a musical piece which is associated therewith set therein.
In a preferred embodiment of the present invention, a selection menu for selecting the story may be displayed in the form of a picture.
In a preferred embodiment of the present invention, the system further includes a memory cartridge detachably mounted in the main unit. The memory cartridge has data for the musical piece and data for the story stored therein. Such construction permits replacement of the cartridge, so that the karaoke system may be accommodated to a variety of requests by users.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and many of the attendant advantages of the present 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:
FIG. 1 is a schematic perspective view showing an embodiment of a karaoke system according to the present invention;
FIG. 2A is a fragmentary front elevation view showing an essential part of a main unit incorporated in the karaoke system shown in FIG. 1;
FIG. 2B is a fragmentary rear view of the essential part of the main unit shown in FIG. 2A;
FIG. 3 is a diagrammatic view showing an electrical circuit incorporated in the karaoke system of FIG. 1;
FIG. 4 is a flow chart showing a manner of operation of the karaoke system shown in FIG. 1 by way of example;
FIG. 5 is a flow chart showing a manner of operation of the karaoke system shown in FIG. 1 in a talk mode;
FIG. 6 is a pictorial view showing a menu image displayed during the course of a karaoke performance by way of example; and
FIGS. 7A, 7 B and 7 C are pictorial views each showing an image displayed during the course of the karaoke performance by way of example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now, a karaoke system according to the present invention will be described with reference to the accompanying drawings.
Referring first to FIG. 1, an embodiment of a karaoke system according to the present invention is illustrated. A karaoke system of the illustrated embodiment generally includes a main unit 1 , a TV acting as a display unit 3 and connected to the main unit 1 through an audio/video cable (hereinafter referred to as “AV cable”) 2 , and a cartridge 4 detachably mounted in the main unit 1 . Alternatively, the main unit 1 may be operatively connected to the display unit by wireless.
The main unit 1 is formed to have a rod-like shape of a thickness sufficient to permit a user to grip it by one hand and includes a head portion which has a microphone 5 integrally incorporated therein, through which a voice of a user or performer is inputted to the main unit 1 of the karaoke system. The main unit 1 is provided on an upper portion of a front surface thereof with an operation section 6 including a variety of operation keys or buttons. Also, the main unit 1 is mounted on a lower end thereof with the AV cable 2 through which the main unit 1 is connected to the TV acting as the display unit 3 . Further, the main unit 1 is provided on a rear surface thereof with a connector 7 in which the cartridge 4 is detachably fitted, as shown in FIG. 2 B.
The operation section 6 , as shown in FIG. 2A, includes a display 10 including light emitting diodes for two figures or digits each constituted of seven segments, tempo keys or buttons 11 for variably controlling a reproducing speed or tempo of music being performed in accordance with the user's choice, volume keys or buttons 12 for variably controlling a volume of a reproduced sound of the music being performed, an echo key or button 13 for setting echo time (delay time) at a desired length, an effect key or button 14 for varying a frequency of an output voice with respect to a frequency of a voice inputted from the microphone 5 thereto to change the input voice into a male voice, a female voice or the like, a cancel key or button 15 for canceling various kinds of setting, selection keys or buttons 16 used for selection operation, a decision key or button 17 for confirming results selected by the selection keys or buttons 16 to be effective, and the like.
Now, an electrical structure of the karaoke system of the illustrated embodiment will be described with reference to FIG. 3 . In FIG. 3, reference numeral 20 designates a control section, which functions to control an audio signal processing section 22 and a video signal processing section 23 according to an operation signal inputted from the operation section 16 and a control program stored in a memory 21 . For this purpose, the control section 20 is constructed so as to read data from the cartridge 4 fitted in the connector 7 to output a performance signal of music selected to the audio signal processing section 22 and output an image signal indicating a title of the music and words thereof to the video signal processing section 23 .
The audio signal processing section 22 is configured so as to subject a sound signal inputted thereto from the microphone 5 and an accompaniment signal outputted from the control section 20 to both mixing and amplification to prepare an audio signal, which is then outputted through the AV cable 2 to the TV 3 . The video signal processing section 23 functions to output, in the form of a video signal, image information for displaying a title of music, words thereof and the like inputted thereto from the cartridge 4 to the TV 3 through the AV cable 2 . Also, the video signal processing section 23 functions to output, in the form of a video signal, a variety of guide information for guiding setting of the keys or buttons arranged on the operation section 6 , such as, for example, an echo, a level of a key, a speed of performed music, a voice change and the like.
The video signal and audio signal thus outputted are inputted to an AV input terminal 25 of the TV 3 acting as an output unit. The video signal thus inputted is displayed in the form of an image on a monitor of the TV 3 . The audio signal is outputted from a loudspeaker of the TV 3 .
The cartridge 4 has a read only memory (ROM) incorporated therein, which has data on musical pieces for a karaoke performance and data on stories to be displayed stored therein. The data on each of the musical pieces include performance information for synthesizing the musical piece (MIDI information), information on a title of music thereof and information on words thereof. The data on each of the stories include a program, image data and letter data.
Now, a manner of operation of the karaoke system of the illustrated embodiment will be described with reference to FIGS. 4 and 5 by way of example.
First, the cartridge 4 is inserted in the connector 7 of the main unit 1 and then a power supply is turned on. This results in a menu image being displayed on the TV 3 (a step ST 1 ). The menu image indicates that any one of a talk mode and a karaoke mode should be selected. Thus, a user may select desired one of the modes by means of the selection keys or buttons 16 and then push the decision key or button 17 (a step ST 2 ).
When the “karaoke mode” is selected, the operation or procedure is transferred to a step ST 3 , so that karaoke mode processing may be carried out. In the karaoke mode processing, titles of musical pieces stored are displayed, thus, the user may select a musical piece which he or she desires to sing for a karaoke performance. Then, when the user pushes the decision button 17 , a melody of the musical piece selected is outputted from the TV 3 and words thereof are displayed thereon. Thus, the user may sing a song of the piece in accordance with the melody. When performance of the musical piece is finished, the operation is turned to the menu image of the step ST 1 .
When the “talk mode” is selected, the operation or procedure is advanced to a step ST 4 , to thereby carry out “talk model” processing. In the talk mode processing, a menu image for the talk mode is displayed on the TV 3 (a step ST 10 ). The menu image is displayed in the form of a picture rather than letters. By way of example, as shown in FIG. 6, the menu image may be displayed in the form of a picture which permits a talk associated with houses, fields and mountains located on an island, as well as a boat floating on a sea to be imagined.
Every time the selection buttons 16 are pushed, a character 30 is moved as indicated by dotted lines and solid lines, following the arrows shown in FIG. 6, so that a genre of a talk associated with a place where the character 30 is positioned is displayed in the form of letters on a display corner 31 defined on an upper left location of a screen of the TV 3 (a step ST 11 ). A genre of a talk displayed on the TV is associated with a place of the character 30 indicated at solid lines. Thus, in FIG. 6, the genre is associated with a sea. Then, the decision button 17 is pushed when a genre of a talk which the user desires to hear is displayed on the TV 3 . When the decision button 17 is thus pushed (a step ST 12 ), any one of two story progress patterns is randomly selected (a step ST 13 ).
When a first one of the two story progress patterns is selected, a talk selected in the step ST 11 is displayed in the form of a combination of pictures and letters like a picture book on the TV 3 (a step ST 14 ). Then, a title of a musical piece associated with the talk is displayed thereon, followed by playing of music of the musical piece (a step ST 15 ). When the playing is finished (a step ST 16 ), the operation is returned to the step ST 10 , so that the menu image may be displayed again.
When a second one of the story progress patterns is selected, the “talk” selected in the step ST 11 is displayed in the form of a combination of pictures and letters like each of pages or leaves of a picture book on the TV 3 (a step ST 17 ). Subsequently, the operation is advanced to a step ST 18 , so that an image or selection menu which asks items to be selected for ramifications such as, for example, “take a boat”, “chat with gulls” or the like may be displayed on the TV 3 . Thus, the user may select a desired one of the items by means of the section buttons 16 , followed by operation of the decision button 17 , so that an image associated with the selected item may be displayed on the TV 3 as if leaves or pages of a picture book are turned over, as shown in FIG. 7 B. This permits the “talk” to be displayed in the form of a combination of pictures and letters on the TV 3 (a step ST 19 ). Then, when a period of time sufficient to permit the user to read through the “talk” elapses, a title of a musical piece associated with the talk is displayed. In the illustrated embodiment, when “chat with gulls” is selected, music of which a title is “Gull Sailors” is displayed on the TV 3 as shown in FIG. 7 C.
Then, a melody of the music is outputted from the TV 3 and words thereof are displayed thereon (a step ST 20 ), so that the user may sing a song in conformity to the melody while confirming the words being on the TV as in the conventional karaoke system. When performance of the music is completed (a step ST 21 ), the operation is returned to the menu image of the step ST 10 .
When another item is selected in the step ST 18 , the operation is advanced to a step ST 22 , so that a “talk” relating to the item selected may be displayed on the TV 3 , a melody of a musical piece relating thereto may be outputted from the TV 3 and words of the musical piece may be displayed on the TV 3 (a step ST 23 ). Thus, the user may sing a song in conformity to the melody while confirming the words being displayed on the TV 3 . When performance of the musical piece is finished (a step ST 24 ), the operation is returned to the menu image of the step ST 10 .
Thus, the illustrated embodiment permits all information to be displayed by not only letters but pictures associated with a story, so that a user or child may associate the image displayed on the TV with the story. Also, the illustrated embodiment permits the music associated with the story to be performed while progressing the story as if a picture book is read. This permits the karaoke system of the illustrated embodiment to stimulate a user's imagination and provide children or youths with much enjoyment.
As can be seen from the foregoing, the karaoke system of the present invention permits a user to enjoy a karaoke performance according to music associated with a story while ensuring development of the story as if leaves of a picture book are turned over. Also, the above-described construction of the present invention permits the karaoke system to be conveniently used by youths and children excluded from the conventional karaoke system.
Also, the karaoke system of the present invention permits music associated with a story to be played between talks, to thereby create an environment which permits a user to not only sing a song merely but sing a song as he or she is reading a fairy tale with his or her mother, resulting in it effectively contributing to culture of sentiments.
Further, the present invention may be configured so as to permit progress of a story to be ramified into branches and music associated with each of the branches to be set. This prevents the story from being rendered simple or monotonous and leads to a variation in music depending on progress of the story, so that a user may enjoy a karaoke performance without losing interest.
In addition, the menu image or selection menu may be displayed in the form of pictures as well as letters. This results in a user associating the pictures with a story and/or music, so that he or she may enhance his or her creative power and thinking power, as well as his or her singing capability.
Moreover, in the present invention, data on music and stories may be stored in the memory cartridge detachably mounted in the main unit. Such construction results in the number of music pieces and stories stored being substantially infinite, so that the karaoke system of the present invention may be accommodated to a variety of requests by users.
While a preferred embodiment of the invention has been described with a certain degree of particularity with reference to the drawings, obvious modifications and variations 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 karaoke system which can be conveniently used by children and youths and help to enhance their creative power and thinking power. The karaoke system includes a main unit connectable to a display unit through a wire or by wireless. The main unit feeds the display unit with image data for displaying words of a music piece on the display unit and music data for playing accompaniment music of the music piece, thereby a karaoke performance being carried out according to the words displayed on the display unit and the accompaniment music outputted from the display unit. In the karaoke system thus constructed, the main unit is constructed so as to permit the display unit to display images constituting at least one story in order and so as to output words and accompaniment music of a music piece associated with the story to the display unit during the course of the story. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 11/047,080, filed Jan. 31, 2005, now abandoned.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention generally relates to tools such as scrapers for removing residual material from cans, buckets or similar containers, and also generally relates to trowels for spreading materials on a surface.
The use of scrapers and trowels to remove various materials such as adhesives, grouts, cements, plaster, resin, stucco, paint and the like from cans, buckets or other containers is well known in the prior art. Examples of such scrapping tools are shown for example in U.S. Pat. Nos. 4,355,432; 4,627,128; 4,987,635; and 5,875,515. When using such scrapping tools to apply a material, some material is removed from the container with the tool, then the material is deposited upon the surface to which the material is to be applied such as a surface to be tiled. The user must then put the scrapping tool away and pick up a different tool such as a trowel which is then used to spread the material on the surface. This process of switching from one tool to another then back again can be time consuming and tedious. A tool which functioned to improve the efficiency of this process would be desirable.
SUMMARY OF THE INVENTION
The present invention is a combination squeegee (i.e., a scraper) and hand trowel tool. The tool can be conveniently used to first remove a material from a can, bucket or other material container and then used to spread the material evenly on a surface or substrate. The tool has a substantially flat blade having a continuous arcuate curved edge portion substantially conforming to a portion of an interior wall of a container for efficiently removing residual material from the interior wall of containers such as cans or buckets and a separate notched edge portion (preferably with indentations or serrations) for evenly spreading the material on a surface. The invention further contemplates a method of using the tool to remove material from a can, bucket or container and applying the material to a surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a combination squeegee and hand trowel constructed in accordance with the present invention.
FIG. 2 is a cross-sectional view of the combination squeegee and hand trowel of FIG. 1 taken along line 2 - 2 thereof.
FIG. 3 is a cross-sectional view of the combination squeegee and hand trowel of FIG. 1 taken along line 3 - 3 thereof.
FIG. 4 is a plan view of another embodiment of a combination squeegee and hand trowel constructed in accordance with the present invention.
FIG. 5 is a plan view of another embodiment of a combination squeegee and hand trowel constructed in accordance with the present invention.
FIG. 6 is a plan view of another embodiment of a combination squeegee and hand trowel constructed in accordance with the present invention.
FIG. 7 is a perspective view yet another embodiment of a combination squeegee and hand trowel constructed in accordance with the present invention.
FIG. 8 is a side cross-sectional view showing the use of the tool of FIG. 1 for removing material from an interior wall of a container.
FIG. 9 is a top plan view illustrating a curved edge portion of the combination squeegee and hand trowel disposed substantially adjacent an interior wall of a container.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIGS. 1-3 , shown therein is a combination squeegee and hand trowel 10 constructed in accordance with the present invention. The combination squeegee and hand trowel 10 (hereinafter also referred to as tool) is provided with a substantially flat blade 12 having an upper surface 14 and a lower surface 16 . A handle 18 is connected to the flat blade 12 so as to extend upwardly from the upper surface 14 of the blade 12 so that a person can grasp the handle 18 . The handle 18 can be releaseably or non-releaseably connected to the blade 12 of the tool 10 .
As shown in FIG. 1 , the blade 12 has a semi-circular configuration (i.e. the shape of a half-circle) and has a curved edge 20 and a notched edge 22 . The curved edge 20 is a continuous arc which extends from a first end 24 of the notched edge 22 to a second end 26 of the notched edge 22 . That is, the blade 12 is provided with a continuous arcuate curved edge 20 and the curved edge 20 of the blade 12 is sized to substantially correspond to a portion of a curved interior sidewall of the container for which the blade 12 is used to remove material from the interior sidewall of the container as will be described in more detail hereinafter.
The notched edge 22 includes a plurality of notches 28 , only a portion of which are specifically indicated by a reference numeral. The configuration of the notched edge 22 can vary widely and will depend, to a large extent, on what the tool 10 is to be used for. For example, the notched edge 22 is shown in FIG. 2 as being crenelate, a desired configuration when using the tool 10 to apply an adhesive to a surface, such as when laying tile.
The blade 12 has a length 30 and a width 32 which extends perpendicularly from a center point 33 of the notched edge 22 to the curved edge 20 . The length 30 and width 32 of the blade 12 will vary depending on the size of the container with which the blade 12 is used to scrape material from the sidewall of the container. That is, the blade 12 is provided with a sufficient length 30 and a sufficient width 32 so that the curved edge 20 of the blade 12 can be disposed substantially adjacent a portion of the curved interior surface or wall of the container whereby a material on the sidewall can be removed by the tool 10 . For example, when using the tool 10 to remove material from the sidewall of a conventional five gallon bucket, desirable results have been obtained wherein the blade 12 of the tool 10 is provided with a length of about 10.25 inches and a width of about 6.75 inches.
As previously stated, the curved edge 30 of the blade 12 has a continuous curvature which conforms to or compliments the curvature of an inner surface of a side wall of a container with which the tool 10 is anticipated to be used. That is, the curved edge 30 of the blade 12 is void of any straight line segments. Thus, the particular size of the blade 12 of the tool 10 will be determined based upon the size of the container with which the tool 10 is to be used. Further, the material removed from the container can be tile adhesives, grouts, stucco, plaster, or other bonding materials as well as paints which are used in construction. Such containers are well known in the art. Thus, no further discussion concerning the size of such containers or the nature of such containers is deemed necessary.
As noted above, the handle 18 of the tool 10 is sized to permit a person to grip the handle so that the tool 10 can be used to scrape material from the inner surface of the sidewall of the container. Thus, the handle 18 has a length 34 , a width 36 and a height 38 . The length 34 , width 36 and height 38 of the handle 18 can vary widely depending on the size of the blade 12 . For example, desirable results have been obtained wherein the length 34 of the handle 18 is about 6.75 inches, the width 36 is about 1 inch and the height 38 is about 1.5 inches.
To enhance removal of material from the interior surface of the sidewall of the container, the curved edge 20 of the blade 12 is desirably beveled substantially as shown. The degree of beveling of the curved edge 20 of the blade 12 can vary widely. However, desirable results have been achieved wherein the curved edge 20 of the blade 12 has a bevel height 40 of about 0.125 inch and a bevel width 42 of about 0.25 inch.
As previously noted, the notched edge 22 of the blade 12 is provided with a plurality of notches 28 . Each notch 28 has a notch width 44 . The notched edge 22 of the blade 12 shown in FIGS. 1-3 has a crenelate shape. The distance between the notches 28 of the notched edge 22 can vary widely depending on the intended use of the tool 10 , as can the width of the notches 28 . For example, the notches 28 can be provided with a notched width 40 of about 0.25 inches.
Referring now to FIGS. 4-6 , shown therein are three additional embodiments of a tool constructed in accordance with the present invention wherein the notched edges of the tools have alternate notch patterns. Shown in FIG. 4 is a tool 10 a having a flat blade 12 a . The blade 12 a has a handle 18 a connected to an upper surface 14 a of the blade 12 a such that the handle 18 a extends upwardly therefrom. The blade 12 a has a semi-circular configuration, and as such has a curved edge 20 a and a notched edge 22 a . The curved edge 20 a is a continuous arc which extends from a first end 24 of the notched edge 22 a to a second end 26 a of the notched edge 22 a . Thus, with exception of the configuration of the notched edge 22 a , the blade 12 a of the tool 10 a is similar in construction and functioned to the blade 12 of the tool 10 hereinbefore described with reference to FIGS. 1-3 . That is, the notched edge 22 a of the blade 12 a of the tool 10 a has a serrated or “toothed” pattern rather than the notched pattern of the blade 12 of the tool 10 .
Referring now to FIG. 5 , shown therein is a tool 10 b constructed in accordance with the present invention. The tool 10 b is provided with a flat blade 12 b having a handle 18 b connected to an upper surface 14 b of the blade 12 b such that the handle 18 b extends upwardly therefrom. The blade 12 b has a semi-circular configuration and as such has a curved edge 20 b and a notched edge 22 b . The curved edge 20 b is a continuous arc which extends from a first end 24 b of the notched edge 22 b to a second end 26 b of the notched edge 22 b . Thus, with exception of the configuration of the notched edge 22 b , the blade 12 b of the tool 10 b is similar in construction and function to the blade 12 of the tool 10 hereinbefore described with reference to FIGS. 1-3 . That is, the notched edge 22 b of the blade 12 b of the tool 10 b has a crenelate or scalloped pattern which is “curved” or “wavy”.
Referring now to FIG. 6 , shown therein is a tool 10 c constructed in accordance with the present invention. The tool 10 c has a flat blade 12 c . The blade 12 c has a handle 18 c connected to an upper surface 14 c of the blade 12 c such that the handle 18 c extends upwardly therefrom. The blade 12 c has a semi-circular configuration and as such has a curved edge 20 c and a notched edge 22 c . The curved edge 20 c is a continuous arc which extends from a first end 24 c of the notched edge 22 c to a second end 26 c of the notched edge 22 c . Thus, with exception of the configuration of the notched edge 22 c , the blade 12 c of the tool 10 c is similar in construction and function to the blade 12 of the tool 10 hereinbefore described with reference to FIGS. 1-3 . That is, the notched edge 22 c of the blade 12 c of the tool 10 c has a pattern wherein smaller notches 28 c alternate with larger notches 28 cc.
While certain patterns for the notched edge of the tools hereinbefore described have been shown, it will be readily apparent to those skilled in the art that other notch patterns can be employed in the construction of the notched edge of the tool of the present invention.
As noted before, the handle 18 of the tool 10 may be releaseably connected, i.e. detachable, from the blade 12 . Shown in FIG. 7 is a tool 10 d which includes a blade 12 d , a handle 18 d and a connector assembly 47 for connecting the handle 18 d to the blade 12 d . The blade 12 d is provided with a curved edge 20 d and a notched edge 22 d . The blade 12 d of the tool 10 d may be the same as the blade of any other tool described herein. The tool 10 d differs from the tools 10 - 10 c described herein in that the handle 18 d is detachably connected to the blade 12 d.
The connector assembly 47 includes a female connector 48 and a male connector 49 . The female connector 48 is formed integrally with the blade 12 d so as to extend outwardly from an upper surface 14 d of the blade 12 d substantially as shown. The male connector 49 is formed on one end of the handle 18 d and is adapted to matingly engage the female connector 48 so that the handle 18 d can be connected to the blade 12 d.
Any suitable mechanism can be used as the connector assembly 47 . For example, the female connector 48 can include a housing having an opening therein with internally disposed threads and the male connector 49 can be a threaded portion on one end of the handle 18 which can be inserted within the housing for mating engagement with the threads in the housing of the female connector 48 substantially as shown. Thus, the handle 18 d can be operably connected or disconnected from the blade 12 d via the connector assembly 47 .
Any of the tools 10 - 10 d contemplated herein or alternate embodiments of them may be constructed of materials known to be used in the construction of trowels, squeegees, scrapers, or the like, including metals, polymers, plastics (including thermoplastics), rubber, wood, wood products, cardboard, or combinations thereof. The tools 10 - 10 d may be flexible or rigid. The tools described herein, such as tools 10 - 10 c , may be formed as an integral one piece construction molded from a thermoplastic material, although the tool 10 d is shown as constructed of separate materials such as a separate blade 12 d and a separate handle 18 d which are connected together via the connector assembly 47 hereinbefore described.
Referring now to FIGS. 8 and 9 , the manner of usage and operation of the combination squeegee and hand trowel of the present invention will now be described with reference to the tool 10 . Once a cylindrically shaped container 50 , such as a gallon bucket, a 5 gallon bucket or a 10 gallon bucket has been opened, the tool 10 is inserted into the container 50 to remove material therefrom. Once the container 50 has been substantially emptied the curved edge 20 of the tool 10 , which is arcuately shaped to substantially correspond to an arc configuration of a segment of an inner surface 52 of a sidewall 54 of the container 50 , is positioned adjacent the segment of the inner surface 52 of the sidewall 54 and the interior surface 52 of the sidewall 54 is scraped with the curved edge 20 of the tool 10 to remove residual material from the inner surface 52 of the sidewall 54 . The scraping motion utilizing the curved edge 20 of the tool 10 is repeated until substantially all the material has been removed from the inner surface 52 of the sidewall 54 of the container 50 . It should be noted that the tool 10 may also be used to remove residual amounts of material from the bottom of the container 50 or from beneath an interior rim of the container 50 . As such, removal of substantially all material within the container 50 can be effected utilizing the tool 10 (or any other tool of the present invention). Furthermore, the tools described herein can be utilized to spread or otherwise apply material removed from a container, such as the container 50 , to a surface or substrate in a manner appropriate for the material. That is, the notched edge 22 of the blade 12 of the tool 10 can be utilized to effectively spread material removed from the container 50 as required for a particular application.
The size of the container 50 can vary widely but the container 50 will typically be of a size used in various manners of construction and remodeling. Further, the size of the tool 10 and any other tools described herein, will vary and desirably be sized and configured to enhance removal of material from the interior surface 52 of the sidewalls 54 of the container 50 .
It is to be understood that the dimensional relationships of the materials from which the tools 10 - 10 d and the handles 18 and 18 d are fabricated, and the components of the tools 10 - 10 d of the invention such as the blades 12 - 12 d or the handles 18 and 18 d , can vary, as well as the configuration of the handles 18 and 18 d of the tools 10 - 10 d.
Therefore, the foregoing is considered as illustrative only of the tools 10 - 10 d of the present invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the tools 10 - 10 d and their uses are not limited to the exact construction and operation shown and described, and all suitable modifications and equivalents of the tools 10 - 10 d described herein may be resorted to, and fall within the scope of the present invention. | The present invention is a combination squeegee (i.e., a scraper) and hand trowel tool. The tool can be conveniently used to first remove a material from a can, bucket or other material container and then used to spread the material evenly on a surface or substrate. The tool has a blade having a curved edge portion for removing material from cans or buckets and a separate notched edge portion (preferably with indentations or serrations) for evenly spreading the material on a surface. The invention further contemplates a method of using the tool to remove material from a can, bucket or container and applying the material to a surface. | 4 |
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 10/057,260, filed Oct. 29, 2001 now U.S. Pat. No. 6,605,596 which claims the benefit of priority from U.S. provisional application No. 60/244,469, filed Oct. 31, 2000, the contents of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
This invention relates to synthetic indolocarbazole analogues and uses thereof. More particularly, this invention relates to compounds having modifications of the core structure 12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione, containing substitutions consisting of a 2,3,9-trihydroxy pattern, particularly cyclic and acyclic ethers at the 2- and 3-hydroxy positions. The present invention further relates to compounds having modifications of the indolocarbazole core structure by introducing an additional ring structure. The present invention also relates to compositions and methods of using such indolocarbazole analogues for the inhibition of topoisomerase I activity, which are useful in inhibiting the proliferation of tumor cells.
BACKGROUND OF THE INVENTION
Human topoisomerase I (Topo I) is an enzyme critical to the viability of cellular function that is an attractive target for the design and development of anticancer therapeutics. Currently there are two anticancer agents approved by the Food and Drug Administration for the clinical treatment of cancers: topotecan (Hycamtin) and CPT-11 (Camptosar), both of which are structural analogues of the natural product camptothecin.
Eukaryotic DNA Topoisomerase I (Topo I) is an essential nuclear enzyme responsible for the organization and modulation of the topological dilemmas in DNA, such as overwinding, underwinding and catenation. Topo I plays a critical role in allowing a cell to appropriately replicate, transcribe, repair genetic information, and perhaps carry out other DNA processes such as chromatin assembly, recombination and chromosome segregation. 1,2
Topo I is a 100 kD monomeric protein that catalyzes changes in the topological state of double-stranded DNA (dsDNA) in increments of one linking number. 3 The three-dimensional structure of human Topo I has been reported. 4 The mechanism by which Topo I acts is believed to proceed through induction of a transient single-stranded break in dsDNA via formation of a covalent protein-DNA adduct referred to as the cleavable complex, so named because these complexes are detected as DNA breaks upon treatment with denaturing agents or alkali. The cleavable complex is formed upon transesterification of a DNA phosphodiester linkage by the active site tyrosine-723 residue on human Topo I, resulting in an ester linkage between the enzyme and the 3′-phosphoryl end of the broken DNA strand. This allows free rotation of the protein-bound 3′ end of the broken DNA strand about the intact complementary DNA strand, resulting in relaxation of the duplex in increments of one linking number. Religation of the broken strand (via a second transesterification reaction) and subsequent dissociation of topoisomerase I completes the catalytic cycle.
Topoisomerase I poisons act via stabilization of the cleavable complex, mediated by formation of a ternary complex consisting of drug, topoisomerase I and DNA. 5 Agents such as camptothecin (the prototype topoisomerase I poison) do not bind to DNA directly, nor to topoisomerase I alone, but only to topoisomerase I complexed with DNA. It has been postulated that the stabilized DNA-protein-drug complex causes lethal DNA strand breaks upon collision with the advancing replication fork. It is by this mechanism that the topoisomerase I poison converts the enzyme into a DNA damaging agent, resulting in disruption of DNA replication and, eventually, cell death. This postulate is supported by the fact that camptothecin is highly phase-specific, only killing cells in S-phase.
It has been reported that intracellular levels of topo I are elevated in a number of human solid tumors, relative to the respective normal tissues, suggesting that variations in topo I levels are tumor type specific. 6-8 Thus, topo I represents a promising target for the development of new cancer chemotherapeutic agents against a number of solid tumors. Development of anti-topo I agents offers a new approach to the multi-regimental arsenal of therapies currently used in the clinic for the treatment of cancer.
In addition to the camptothecins, indolocarbazoles have also demonstrated potent antitumor activity via the poisoning of topoisomerase I activity, 9-12 most notably ED-110, 13 NB-506, 14 and J-107088. 15 The indolocarbazole analogue bearing a 3,9-dihydroxy substitution pattern was found to have superior topoisomerase I poisoning capability as well as superior in vitro antitumor activity relative to the other “symmetrical” dihydroxylated regioisomers. 16 The 3,9-dihydroxy analogue also exhibited impressive in vivo antitumor activity against the DU-145 human prostate tumor line xenotransplanted into nude mice.
SUMMARY OF THE INVENTION
The present invention relates to compounds, compositions and methods for the inhibition of topoisomerase I activity.
Accordingly, one object of the invention is to provide compounds of the general formulas I and II,
R 1 is selected from the group consisting of H, OH, NH 2 , NO 2 , SO 2 NRR′, COR, CO 2 R and CONRR′, alkylcarbonyl, alkylcarbonyloxy, C 1-6 alkyl, C 1-6 alkyloxy, C 1-6 alkylamino, di(C 1-6 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyl, di(C 1-6 alkyl)amino-C 1-6 alkyl, or cyclo(C 3-6 )alkyl, C 1-6 alkylsulphinyl, C 1-6 alkylsulphonyl, wherein said alkyl is straight-chained or branched, saturated or unsaturated, and is optionally substituted with one or more substituents selected from the group consisting of halogen, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or aryl, aryl-C 1-6 alkyl, aryloxy, aryl-C 1-6 alkyloxy, arylcarbonyloxy, arylamino, di(aryl)amino, aryl-C 1-6 alkylamino, di(aryl-C 1-6 alkyl)amino, arylsulphinyl, arylsulphonyl, wherein said alkyl is defined as above; aryl comprises six membered aromatic carbocycles such as phenyl or a polycyclic aromatic hydrocarbon such as naphthyl, phenanthracenyl, indanyl, indenyl, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or heterocycle, (heterocycle)C 1-6 alkyl, (heterocycle)oxy, (heterocycle)-C 1-6 alkyloxy, (heterocycle)carbonyloxy, (heterocycle)amino, di(heterocycle)amino, [(heterocycle) C 1-6 alkyl]amino, di[(heterocycle)C 1-6 alkyl]amino, wherein said alkyl is defined as above; heterocycle comprises 3–8 membered heterocycles such as oxirane, aziridine, pyrrole, pyrroline, pyrrolidine, pyrrolidone, pyrrolindione, pyrazole, imidazole, imidazoline, triazole, (1,2,4)-triazine-3,5-dione, furan, tetrahydrofuran, thiophene, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, piperidine, piperazine, pyran, morpholine, azepine, or polycyclic systems such as indole, indoline, indolizine, isoindole, indazole, benzthiophene, isobenzthiophene, benzofuran, isobenzofuran, benzimidazole, benzoxazole, benzothiazole, benzotriazole, quinoline, isoquinoline, quinazoline, benzotriazine, flavone, phenanthridine, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or carbocycle, carbocycle-C 1-6 alkyl, (carbocycle)oxy, (carbocycle)C 1-6 alkyloxy, (carbocycle)carbonyloxy, (carbocycle)amino, di(carbocycle)amino, [(carbocycle)C 1-6 alkyl]amino, di[(carbocycle) C 1-6 alkyl]amino, wherein said alkyl is defined as above; carbocycle comprises 3–8 membered carbocycles such as cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, cycloheptane, cyclooctane, or polycyclic systems such as bicycle[1.1.0]butane, bicycle[3.2.1]octane, spiro[4.5]decane, pinane, norpinane, norbornane, perhydronaphthalene, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or carbamate of the formula —NH—CO—R″, wherein R″ comprises H, C 1-6 alkyl, aryl-C 1-6 alkyl, (heterocycle)C 1-6 alkyl, wherein said alkyl, aryl and heterocycle are defined as above,
or aryl carbamate of the formula —NH—CO—Ar, wherein said aryl is defined as above,
or heterocycle carbamate of the formula —NH—CO-heterocycle, wherein said heterocycle is defined as above,
or carbocycle carbamate of the formula —NH—CO— carbocycle, wherein said carbocycle is defined as above,
or sulfonamide of the formula —NH—S(O) n R, wherein said n is 1 or 2,
R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from the group consisting of H, halogen, CN, OH, SH, NH 2 , N 3 , NO 2 , CO 2 R, CONRR′, SO 3 R, SO 2 NRR′, alkylcarbonyloxy, alkylcarbamate, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulphinyl, C 1-6 alkylsulphonyl, C 1-6 alkylamino, di(C 1-6 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyl, di(C 1-6 alkyl)amino-C 1-6 alkyl, or cyclo(C 3-6 )alkyl, wherein said alkyl is straight-chained or branched, saturated or unsaturated, and is optionally substituted with one or more substituents selected from the group consisting of halogen, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or aryl, aryl-C 1-6 alkyl, aryloxy, aryl-C 1-6 alkyloxy, arylsulphinyl, arylsulphonyl, aryl-C 1-6 alkylsulphinyl, aryl-C 1-6 alkylsulphonyl, arylcarbonyloxy, arylcarbamate, arylamino, di(aryl)amino, aryl-C 1-6 alkylamino, di(aryl-C 1-6 alkyl)amino, wherein said alkyl is defined as above; aryl comprises six membered aromatic carbocycles such as phenyl or a polycyclic aromatic hydrocarbon such as naphthyl, phenanthracenyl, indanyl, indenyl, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or heterocycle, (heterocycle)C 1-6 alkyl, (heterocycle)oxy, (heterocycle)C 1-6 alkyloxy, (heterocycle)sulphinyl, (heterocycle)sulphonyl, heterocycle-C 1-6 alkylsulphinyl, heterocycle-C 1-6 alkylsulphonyl, (heterocycle)carbonyloxy, (heterocycle)amino, di(heterocycle)amino, [(heterocycle)C 1-6 alkyl]amino, di[(heterocycle)C 1-6 alkyl]amino, wherein said alkyl is defined as above; heterocycle comprises 3–8 membered heterocycles such as oxirane, aziridine, pyrrole, pyrroline, pyrrolidine, pyrrolidone, pyrrolindione, pyrazole, imidazole, imidazoline, triazole, (1,2,4)-triazine-3,5-dione, furan, tetrahydrofuran, thiophene, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, piperidine, piperazine, pyran, morpholine, azepine, or polycyclic systems such as indole, indoline, indolizine, isoindole, indazole, benzthiophene, isobenzthiophene, benzofuran, isobenzofuran, benzimidazole, benzoxazole, benzothiazole, benzotriazole, quinoline, isoquinoline, quinazoline, benzotriazine, flavone, phenanthridine, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or carbocycle, carbocycle-C 1-6 alkyl, (carbocycle)oxy, (carbocycle)-C 1-6 alkyloxy, (carbocycle)carbonyloxy, (carbocycle)amino, di(carbocycle)amino, [(carbocycle)C 1-6 alkyl]amino, di[(carbocycle) C 1-6 alkyl]amino, wherein said alkyl is defined as above; carbocycle comprises 3–8 membered carbocycles such as cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, cycloheptane, cyclooctane, or polycyclic systems such as bicycle[1.1.0]butane, bicycle[3.2.1]octane, spiro[4.5]decane, pinane, norpinane, norbornane, perhydronaphthalene, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′
or R 2 and R 3 , R 4 and R 5 , or R 3 and R 4 together form a non-aromatic 5–8 membered cyclic or heterocyclic rings;
R 8 , R 9 , R 10 and R 11 are independently selected from the group consisting of H, OH, NH 2 , alkylcarbonyloxy, alkylcarbamate, C 1-6 alkyl, C 1-6 alkyloxy, C 1-6 alkylamino, di(C 1-6 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyl, di(C 1-6 alkyl)amino-C 1-6 alkyl, cyclo(C 3-6 )alkyl, aryl, carbocyclic or heterocyclic, wherein said alkyl, aryl, carbocyclic and heterocyclic are defined above; R 8 and R 9 together, R 10 and R 11 together can independently form ═O;
R 12 represents an optionally substituted pentose or hexose group or said pentose and/or hexose may be linked to form an oligosaccharide,
or H, OH, NH 2 , SO 2 NRR′, CO 2 H, CONRR′, C 1-12 alkylcarbonyl, C 1-12 alkyloxycarbonyl, C 1-12 alkylcarbonyloxy, C 1-12 alkyl, C 1-12 epoxyalkyl, C 1-12 alkyloxy, C 1-6 alkyloxy-C 1-6 alkyl, C 1-6 alkylthio-C 1-6 alkyl, C, 1-12 alkylamino, di(C 1-12 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyl, di(C 1-6 alkyl)amino-C 1-6 alkyl, C 1-6 alkyloxy-C 1-6 alkylamino, di(C 1-6 alkyloxy-C 1-6 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyloxy, di(C 1-6 alkylamino)-C 1-6 alkyloxy, cyclo(C 3-6 )alkyl, C 1-12 alkylsulphinyl, C 1-12 alkylsulphonyl, C 1-6 alkylsulphinyl-C 1-6 alkyl, C 1-6 alkylsulphonyl-C 1-6 alkyl, polyethyleneglycole (PEG), polyamine, wherein said alkyl is straight-chained or branched, saturated or unsaturated, and is optionally substituted with one or more substituents selected from the group consisting of halogen, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or aryl, aryl-C 1-6 alkyl, aryloxy, aryl-C 1-6 alkyloxy, arylcarbonyloxy, arylamino, di(aryl)amino, aryl-C 1-6 alkylamino, di(aryl-C 1-6 alkyl)amino, arylsulphinyl, arylsulphonyl, arylsulphinyl-C 1-6 alkyl, arylsulphonyl-C 1-6 alkyl, wherein said alkyl is defined as above; aryl comprises six membered aromatic carbocycles such as phenyl or a polycyclic aromatic hydrocarbon such as naphthyl, phenanthracenyl, indanyl, indenyl, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or heterocycle, (heterocycle)C 1-6 alkyl, (heterocycle)oxy, (heterocycle)C 1-6 alkyloxy, (heterocycle)carbonyloxy, (heterocycle)amino, di(heterocycle)amino, [(heterocycle)C 1-6 alkyl]amino, di[(heterocycle)C 1-6 alkyl]amino, wherein said alkyl is defined as above; heterocycle comprises 3–8 membered heterocycles such as oxirane, aziridine, pyrrole, pyrroline, pyrrolidine, pyrrolidone, pyrrolindione, pyrazole, imidazole, imidazoline, triazole, (1,2,4)-triazine-3,5-dione, furan, tetrahydrofuran, thiophene, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, piperidine, piperazine, pyran, morpholine, azepine, or polycyclic systems such as indole, indoline, indolizine, isoindole, indazole, benzthiophene, isobenzthiophene, benzofuran, isobenzofuran, benzimidazole, benzoxazole, benzothiazole, benzotriazole, quinoline, isoquinoline, quinazoline, benzotriazine, flavone, phenanthridine, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or carbocycle, (carbocycle)C 1-6 alkyl, (carbocycle)oxy, (carbocycle)C 1-6 alkyloxy, (carbocycle)carbonyloxy, (carbocycle)amino, di(carbocycle)amino, [(carbocycle)C 1-6 alkyl]amino, di[(carbocycle)C 1-6 alkyl]amino, wherein said alkyl is defined as above; carbocycle comprises 3–8 membered carbocycles such as cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, cycloheptane, cyclooctane, or polycyclic systems such as bicycle[1.1.0]butane, bicycle[3.2.1]octane, spiro[4.5]decane, pinane, norpinane, norbornane, perhydronaphthalene, and is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
or carbamate of the formula —NH—CO—R″, wherein R″ comprises H, C 1-6 alkyl, aryl-C 1-6 alkyl, heterocycle-C 1-6 alkyl, wherein said alkyl, aryl and heterocycle are defined as above,
or aryl carbamate of the formula —NH—CO—Ar, wherein said aryl is defined as above,
or heterocycle carbamate of the formula —NH—CO-heterocycle, wherein said heterocycle is defined as above,
or carbocycle carbamate of the formula —NH—CO-carbocycle, wherein said carbocycle is defined as above,
or sulfonamide of the formula —NH—S(O) n R, wherein said n is 1 or 2,
X 1 , X 2 and X 3 are independently selected from the group consisting of O, N, S, NH, (CH) n , (CH 2 ) n , CO, wherein said n is 1, 2 or 3, and the hydrogen atom in NH, CH, CH 2 is optionally substituted with one or more substituents selected from the group consisting of halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R and CONRR′,
Z is selected from the group consisting of CH 2 , NH, O, S; R and R′ are independently selected from the group consisting of H, C 1-12 alkyl, aryl, heterocyclic, carbocyclic, and cyclo(C 3-6 )alkyl, wherein said alkyl is optionally substituted with one or more substituents selected from the group consisting of halogen, OH, NH 2 , N 3 , SH, CN, CO 2 H, CO 2 (C 1-3 alkyl), S(C 1-3 alkyl), O(C 1-3 alkyl), NH(C 1-3 alkyl), NH(C 1-3 alkyl) 2 , and is saturated or unsaturated; or R and R′ together with the nitrogen atom to which they are attached form a non-aromatic 5–8 membered heterocycle containing one or two of the same or different heteroatoms selected from the group consisting of O, N, and S;
or a pharmaceutically acceptable salt thereof.
Pentoses in the compounds of the invention include, without limitation, ribose, arabinose, xylose, 2-deoxyribose, 2,3-dideoxypentofuranose, 2,3-didehydro-2,3-dideoxypentofuranose, and derivatives thereof. Hexoses in the compounds of the invention include, without limitation, allose, glucose, mannose, galactose, glucosamine, galactosamine, 2-deoxyglucose, 4-O-methylglucose, rhamnose, and glucuronic acid, and derivatives thereof. R 12 can include pentoses and hexoses that are linked together to form oligosaccharides such as 6-O-α-D-2-deoxy-4-aminoribosyl-β-D-4-methylglucopyranose disaccharide. The pentoses and hexoses may be optionally substituted as follows. The hydrogen and hydroxy groups of the pentose and hexose groups may be independently replaced with one or more substituents independently selected from H, halogen, R, N 3 , CN, NO 2 , SR, OR, NRR′, SOR, SO 2 R, SO 3 R, SO 2 NRR′, COR, CO 2 R, CONRR′, alkylcarbonyloxy, alkylcarbamate, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulphinyl, C 1-6 alkylsulphonyl, C 1-6 alkylamino, di(C 1-6 alkyl)amino, C 1-6 alkylamino-C 1-6 alkyl, di(C 1-6 alkyl)amino-C 1-6 alkyl, cyclo(C 3-6 )alkyl, aryl, carboncyclic, and heterocyclic, wherein said alkyl, aryl, carbocyclic and heterocyclic groups are as defined above. In addition, one or more hydroxyl groups of pentose and hexose may be derivatized or oxidized to form, for example, esters, amides, or ethers, or reduced to form unsaturated groups. One or more ring atoms of pentose and hexose may also be optionally replaced with CH 2 , CHR, CR 2 , O, S, NH, or NR.
Another object of the invention is to provide a method of inhibiting toposisomerase I activity in a mammal comprising administering to a mammal in need of inhibition of topoisomerase I activity an effective amount of a compound of the formula I or II.
Yet another object of the invention is to provide compositions for inhibiting topoisomerase I activity in a mammal in need of inhibition of topoisomerase I activity an effective amount of at least one compound of the formulas I and II.
These and other objects of the invention will be clear in light of the detailed description below.
DETAILED DESCRIPTION OF THE INVENTION
The description of the invention herein should be construed in congruity with the laws and principals of chemical bonding. It is to be understood that the present invention includes any and all possible stereoisomers, geometric isomers, diastereoisomers, enantiomers and anomers, unless a particular description specifies otherwise.
The compounds of this invention can exist in the form of pharmaceutically acceptable salts. Such salts include addition salts with inorganic acids such as hydrochloric acid and sulfuric acid, and with organic acids such as acetic acid, citric acid, methanesulfonic acid, toluenesulfonic acid, tartaric acid amd maleic acid. Further, in case the compounds of this invention contain an acidic group, the acidic group can exist in the form of an alkali metal salt such as a potassium salt and a sodium salt; an alkaline earth metal salts such as magnesium salt and calcium salt; and salts with organic bases such as triethylammonium salt and an arginine salt. The compounds of the present invention may be hydrated ot non-hydrated.
The compounds disclosed in the present invention are useful as antitumor agents for the treatment and/or prevention of cancer, either alone or with a carrier. Cytotoxic agents are often employed as anticancer agents to control or eradicate tumors. Topo I poisons are useful cytotoxic agents, and two Topo I poisons related to camptothecin, Camptosar and Hycamtin (topotecan) are currently used clinically for the treatment of tumors. Indolocarbazoles are a different class of Topo I poison that represent useful agents for the treatment of tumors. In particular, Topo I-poisoning compounds disclosed in this invention were shown to be highly cytotoxic against human ovarian and prostate tumor cells.
Indolocarbazole analogues of this invention may be formulated as a solution of lyophilized powders for parenteral administration, including, but not limiting to, intravenous, cutaneous, subcutaneous, intramuscular and intraperitoneal routes. Powders may be reconstituted by addition of a suitable diluent or other pharmaceutically acceptable carrier prior to use. The liquid formulation is generally a buffered, isotonic, aqueous solution. Examples of suitable diluents are normal isotonic saline solution, standard 5% dextrose in water or in buffered sodium or ammonium acetate solution. Such formulation is especially suitable for parenteral administration, but may also be used for oral administration. It may be desirable to add excipients such as polyvinylpyrrolidone, gelatin, hydroxycellulose, acacia, polyethylene glycol, mannitol, sodium chloride, or sodium acetate.
Alternatively, the compounds of the present invention may be encapsulated, tableted, or incorporated into an emulsion (oil-in-water or water-in-oil) syrup for oral administration. The dosage forms can be pills, powders, granules, elixirs, tinctures and suspensions, and can be designed as a sustained release or timed release. Pharmaceutically acceptable solids or liquid carriers, which are generally known in the pharmaceutical formulary arts, may be added to enhance or stabilize the composition, or to facilitate preparation of the composition. Solid carriers include starch (corn or potato), lactose, calcium sulfate dihydrate, terra alba, croscarmellose sodium, magnesium stearate or stearic acid, talc, pectin, acacia, agar, gelatin, maltodextrins and microcrystalline cellulose, or colloidal silicon dioxide. Liquid carriers include syrup, peanut oil, olive oil, corn oil, sesame oil, saline, and water. The carrier may also include a sustained release material such as glyceryl monostearate or glyceryl distearate, alone or with a wax. The amount of solid carrier varies but, preferably, will be between about 10 mg to about 1 g per dosage unit.
In addition, compounds of this invention may be given by inhalation, intranasal, rectal, vaginal, urethral, ocular, transdermal, transpulmonary, mucosal, transmucosal, topical, intratumoral and irrigation administration.
One aspect of the present invention involves administration of the compounds of the present invention, or pharmaceutically acceptable salts or solvates thereof, to a mammal implanted with a tumor or susceptible to cancer formation. The dosage ranges for administration of indolocarbazole analogues disclosed in this invention are those to produce the desired affect. The dosage will generally vary with age, body weight, extent of the disease, and contraindications, if any. The dosage will also be determined by the existence of any adverse side effects that may accompany the compounds. It is always desirable, whenever possible, to keep adverse side effects to a minimum. One skilled in the art can easily determine the appropriate dosage, scheduling, and method of administration for the exact formulation of the composition being used in order to achieve the desired effective concentration in the individual patient. However, the dosage can vary from between about 1 mg/kg/day to about 500 mg/kg/day, and preferable from between about 1 mg/kg/day to about 50 mg/kg/day.
Preferred compounds of formula I include those wherein Z is NH.
Preferred compounds of formula I include those wherein R 2 , R 3 , R 4 and R 5 are each H.
Preferred compounds of formula I include those wherein R 2 , R 3 and R 4 are each H and R 5 is OH or F.
Preferred compounds of formula I include those wherein R 2 , R 3 and R 5 are each H, and R 4 is OH, NH 2 , Br, or F.
Preferred compounds of formula I include those wherein R 2 is OH, NH 2 , or F, and R 3 , R 4 and R 5 are each H.
Preferred compounds of formula I include those wherein R 2 and R 5 are both H, and R 3 and R 4 are both OH.
Preferred compounds of formula I include those wherein R 2 , R 4 , and R 5 are each H, and R 3 is CH 3 , N 3 , NO 2 , NH 2 , Br, or F.
Preferred compounds of formula I include those wherein R 2 and R 5 are both H, and R 3 and R 4 are both F.
Preferred compounds of formula I include those wherein R 2 and R 3 are both F, and R 4 and R 5 are both H.
Preferred compounds of formula I include those wherein R 2 is H, and R 3 , R 4 , and R 5 are each F.
Preferred compounds of formula I include those wherein R 4 is H, and R 2 , R 3 , and R 5 are each F.
Preferred compounds of formula I include those wherein R 2 , R 3 , R 4 , and R 5 are each F.
Preferred compounds of formula I include those wherein R 3 and R 5 are both H, R 2 is OH and R 4 is F.
Preferred compounds of formula I include those wherein R 3 and R 4 are both H, R 2 is OH and R 5 is F.
Preferred compounds of formula I include those wherein R 2 and R 5 are both H, R 3 is OH and R 4 is F.
Preferred compounds of formula I include those wherein R 2 and R 5 are both H, R 3 is F and R 4 is OH.
Preferred compounds of formula I include those wherein R 12 is selected from the group consisting of:
Preferred compounds of formula I include those wherein R 8 and R 9 together form ═O.
Preferred compounds of formula I include those wherein R 10 and R 11 together form ═O.
Preferred compounds of formula I include those wherein R 1 is H.
Preferred compounds of formula I include those wherein X 1 and X 3 are both O and X 2 is (CH 2 ) n , wherein n=1, 2, or 3.
Preferred compounds of formula I include those wherein when R 12 is β-D-glucopyranosyl, R 8 and R 9 together and R 10 and R 11 together form ═O, X 1 and X 3 are O and X 2 is (CH 2 ) n (n=1, 2, 3), then R 2 , R 4 , R 5 , R 6 and R 7 are not H at the same time.
Preferred compounds of formula II include those wherein Z is NH.
Preferred compounds of formula II include those wherein R 2 , R 3 , R 4 and R 5 are each H.
Preferred compounds of formula II include those wherein R 2 , R 3 and R 4 are each H and R 5 is OH or F.
Preferred compounds of formula II include those wherein R 2 , R 3 and R 5 are each H, and R 4 is OH, NH 2 , Br, or F.
Preferred compounds of formula II include those wherein R 2 is OH, NH 2 , or F, and R 3 , R 4 and R 5 are each H.
Preferred compounds of formula II include those wherein R 2 and R 5 are both H, and R 3 and R 4 are both OH.
Preferred compounds of formula II include those wherein R 2 , R 4 , and R 5 are each H, and R 3 is CH 3 , N 3 , NO 2 , NH 2 , Br, or F.
Preferred compounds of formula II include those wherein R 2 and R 5 are both H, and R 3 and R 4 are both F.
Preferred compounds of formula II include those wherein R 2 and R 3 are both F, and R 4 and R 5 are both H.
Preferred compounds of formula II include those wherein R 2 is H, and R 3 , R 4 , and R 5 are each F.
Preferred compounds of formula II include those wherein R 4 is H, and R 2 , R 3 , and R 5 are each F.
Preferred compounds of formula II include those wherein R 2 , R 3 , R 4 , and R 5 are each F.
Preferred compounds of formula II include those wherein R 3 and R 5 are both H, R 2 is OH and R 4 is F.
Preferred compounds of formula II include those wherein R 3 and R 4 are both H, R 2 is OH and R 5 is F.
Preferred compounds of formula II include those wherein R 2 and R 5 are both H, R 3 is OH and R 4 is F.
Preferred compounds of formula II include those wherein R 2 and R 5 are both H, R 3 is F and R 4 is OH.
Preferred compounds of formula II include those wherein R 12 is selected from the group consisting of:
Preferred compounds of formula II include those wherein R 8 and R 9 together form ═O.
Preferred compounds of formula I include those wherein R 10 and R 11 together form ═O.
Preferred compounds of formula II include those wherein R 1 is H.
Preferred compounds of formula II include those wherein X 1 and X 3 are both O and X 2 is (CH 2 ) n , wherein n=1, 2, or 3.
Preferred compounds of formula II include those wherein when R 12 is β-D-glucopyranosyl, R 8 and R 9 together and R 10 and R 11 together form ═O, X 1 and X 3 are O and X 2 is (CH 2 ) n (n=1, 2, 3), then R 2 , R 4 , R 5 , R 6 and R 7 are not H at the same time.
One skilled in the art will recognize that modifications may be made in the present invention without deviating from the spirit or scope of the invention. The invention is illustrated further by the following examples, which are not to be construed as limiting the invention in spirit or scope to the specific procedures or compositions described in them.
Synthesis of Target Molecules
The required 5,6-indolodioxan and 5,6-indolodioxole precursors can be prepared starting from 4-methylcatechol, as illustrated in Scheme A for 5,6-ethylenedioxyindole (4). Protection of the ortho-dihydroxy function was achieved using 1,2-dibromoethane, dichloromethane, and acetone, respectively. Nitration using fuming nitric acid followed by indole formation using the Batcho-Leimgruber protocol 17 afforded the desired indoles.
Construction of indolocarbazole analogues can be conducted as illustrated in Scheme B for Ia. N-Benzyloxymethyl-3,4-dibromomaleimide was prepared as previously described. 18 Reaction with an appropriate indole, which had been pre-treated using an organometallic, preferably but not limited to methylmagnesium halide or lithium hexamethyldisilazide, afforded the bromoindolomaleimide intermediates represented by 5. Glucosidation at the indole nitrogen was achieved with 2,3,4,6-tetra-O-benzyl-D-glucose under Mitsunobu conditions 14 (3 equivalents each of the glucose, PPh 3 , and diisopropylazodicarboxylate (DIAD), followed by reversed-phase purification to afford 6. Introduction of the second indole unit was conducted under conditions similar to introduction of the first indole unit, providing the bis-indolylmaleimides represented by 7. Oxidative cyclization of the bis-indolylmaleimides was achieved using either palladium(II) trifluoroacetate in DMF, or via photochemical cyclization, providing indolocarbazoles represented by 8. Others 19 reported oxidative cyclization using alternative reagents such as CuCl 2 and PdCl 2 , but these failed to catalyze the reaction in our hands. Hydrogenolysis of the protective groups (palladium hydroxide, HOAc) afforded the 6-N-hydroxymethyl derivatives represented by 9, which were readily converted to the desired final products, represented by Ia, using ammonium acetate in methanol. All compounds provided spectral and analytical characteristics ( 1 H NMR, 13 C NMR, MS and elemental analysis) consistent with the targeted structures.
The same synthetic strategy described in Scheme B can be extended for the preparation of compounds of general formula I and II, as illustrated in Scheme C and Scheme D.
A versatile method has been reported for the synthesis of indoles containing both hydroxyl and fluorine 20 (Scheme E). Examples of indoles are shown in FIG. 1.
The representative pentose and hexose moieties of R 12 are listed in FIG. 2.
The following examples are illustrative of the invention but do not serve to limit its scope.
EXAMPLE 1
Synthesis of 2,3-ethylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Ia)
Step A: Preparation of 6-methyl-1,4-benzodioxane (1)
A mixture of 4-methylcatechol (33.04 g, 266.1 mmol), 1,2-dibromoethane (100 g, 532.3 mmol), K 2 CO 3 (75.4 g, 545.5 mmol) and sodium iodide (0.2 g, 1.33 mmol) in ethylene glycol (500 mL) was heated to 130° C. under nitrogen for five hours. The solution was allowed to cool to ambient temperature and stirred overnight. After the mixture was filtered through celite, the solution was diluted with brine (800 mL) and extracted with organic solvents (CH 2 Cl 2 /hexane/EtOAc: 1:3:1,3×500 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated to provide a crude oil. Flash silica gel chromatography eluting with hexane (100%) gradient to ether/hexane (8:2) afforded the title intermediate as a colorless oil 20.0 g (50%).
Step B: Preparation of 6-methyl-7-nitro-1,4-benzodioxane (2)
To a solution of 1 (20.0 g, 133.3 mmol) in acetic acid (135 mL) was added a solution of fuming HNO 3 (10 mL) in acetic acid (50 mL) dropwise over 30 minutes. The mixture was stirred at ambient temperature for 10 minutes, then poured into a beaker containing ice to give a crystalline precipitate, which was collected by vacuum filtration and washed with water to afford the product (25.8 g, 99.2%) as an off-white solid.
Step C: Preparation of (E)-4,5-ethylenedioxy-2-nitro-1-pyrrolidinostyrene (3)
A solution of 2 (19.5 g, 100 mmol), N,N-dimethylformamide dimethyl acetal (23.63 g, 198.3 mmol) and pyrrolidine (14.1 g, 198.3 mmol) was heated to 110° C. and stirred for 24 hours under nitrogen. The reaction mixture was cooled, and 250 mL absolute methanol was added. The product crystallized as a bright red solid. Recovery by suction filtration afforded the product (24.3 g, 88.0%).
Step D: Preparation of 4,5-ethylenedioxyindole (4)
To a solution of 3 (24.0 g, 87.0 mmol) in methanol and THF (240 mL, 1:1) was added Raney nickel (2.0 mL) and hydrazine hydrate (3×3.6 mL, 348 mmol) every half hour at ambient temperature under nitrogen. Then, the solution was heated at 45° C. for two hours. The mixture was cooled to room temperature and the catalyst is removed by filtration through a bed of Celite and washed three times with methylene chloride. The filtrate was evaporated and the residue dried by evaporating with toluene (100 mL) to give a crude oil. Flash silica gel column purification eluting with hexane (100%) gradient to ethyl acetate/hexane (40/60%) afforded the title intermediate as an off-white solid (7.0 g, 46.1%).
Step E: Preparation of 2-bromo-3-(5-benzyloxy-1H-indol-3-yl)-N-benzyloxymethylmaleimide (5)
To a solution of 5-benzyloxyindole (8.93 g, 40 mmol) in benzene (150 mL) was added methylmagnesium iodide (14.7 mL, 44.0 mmol, 3 M in ether) at 0° C. The solution was stirred for one hour, and then a solution of N-benzyloxymethyl-3,4-dibromomaleimide (15.0 g, 40 mmol) in benzene (50 mL) and THF (100 mL) was added. The reaction mixture was stirred at 0° C. for 30 minutes and then warmed to room temperature and stirred for one hour. The mixture was diluted with EtOAc (350 mL) then washed with HCL (150 mL, 0.3 N), NaHCO 3 (200 mL) and H 2 O (200 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Crystallization of the crude oil with methanol afforded the title intermediate as a yellow solid (12.50 g, 66.0%).
Step F: Preparation of 2-bromo-3-[5-benzyloxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethylmaleimide (6)
A solution of 5(15.0 g, 29.0 mmol), 2,3,4,5-tetra-O-benzyl-D-glucopyranose (47.02 g, 87.0 mmol) and triphenylphosphine (22.8 g, 87.0 mmol) in THF (800 mL) was cooled to −78° C. Diisopropylazodicarboxylate (17.14 mL, 87.0 mmol) was added dropwise, maintaining the temperature at −78° C., and then stirred for three hours. The solution was warmed to 0° C. with the aid of an ice-water bath and stirring was continued for two hours. The mixture was diluted with EtOAc (1200 mL), washed with HCl , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated. The crude mixture was applied to a reversed-phase Biotage cartridge and eluted with a CH 3 CN/H 2 O (50/50) gradient to CH 3 CN (100%) afforded the title intermediate as a yellow solid 22.3 g (74.0%).
Step G: Preparation of 3-(4,5-ethylenedioxy-1H-indol-3-yl)-4-[5-benzyloxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethyl maleimide (7)
To a solution of 4 (303.2 mg, 1.73 mmol) in THF (35 mL) was added lithium hexamethyldisilazide (LiHMDS, 3.46 mL, 3.46 mmol, 1 M in THF) at 0° C., and the resulting solution stirred for 40 minutes. A solution of 6 in THF (20 mL) was added slowly to the above mixture, followed by stirring for 20 minutes at 0° C. The mixture was diluted with EtOAc (300 mL), washed with HCl (2 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude mixture. Flash silica gel chromatography eluting with a hexane (100%) gradient to EtOAc/hexane (40/60) afforded the title intermediate as a red solid 1.20 g (73.2%).
Step H: Preparation of 2,3-ethylenedioxy-6-benzyloxymethyl-9-benzyloxy-12-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (8)
To a solution of 8 (550 mg, 0.485 mmol) in DMF (28 mL) was added palladium(II) trifluoroacetate (338.5 mg, 1.18 mmol), and stirred at 80° C. for one hour. The solution was cooled to room temperature, diluted with EtOAc (280 mL), and washed with HCl (1 M), NaHCO 3 , brine (150 mL) and H 2 O (3×120 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography eluting with EtOAc/hexane (3:7) afforded 404 mg (73.6%) as a yellow solid.
Step I: Preparation of 2,3-ethylenedioxy-6-hydroxymethyl-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4c]carbazole-5,7-dione (9)
To a solution of 8 (140 mg, 0.1236 mmol) in HOAc (25 mL) was added palladium hydroxide [Pd(OH) 2 , 140 mg]. The reaction was shaken under a hydrogen atmosphere (50 psi) at ambient temperature for 63 hours. The mixture was filtered through an Acrodisc syringe filter and concentrated in vacuo to give a crude solid. Flash chromatography eluting with MeOH/HOAc/EtOAc (12/1/87) afforded 42.0 mg (57.5%) as a yellow solid.
Step J: Synthesis of 2,3-ethylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Ia)
To a solution of 9 (5.0 mg, 0.00845 mmol) in MeOH (0.5 mL) was added NH 4 OH (1.5 mL). The mixture was stirred at ambient temperature for 3 hours, then concentrated in vacuo to give a crude solid. Recrystallization with MeOH/hexane/CHCl 3 afforded 4.3 mg (90.5%) as a yellow solid.
EXAMPLE 2
Synthesis of 2,3-methylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo [3,4-c]carbazole-5,7-dione (Ib)
Step A: Preparation of 3,4-methylenedioxytoluene (10)
A mixture of 4-methylcatechol (26.0 g, 209.4 mmol) and NaOH (18.4 g, 461.0 mmol) in CH 2 Cl 2 (40.0 mL) was heated to 100° C. under nitrogen for 2 hours. The solution was allowed to cool to ambient temperature and diluted with ethyl acetate (500 mL). The mixture was washed with NaHCO 3 (200 mL) and H 2 O (2×200 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude oil. Flash chromatography eluting with hexane (100%) gradient to ether/hexane (1:1) afforded the title intermediate as a colorless oil 20.5 g (71.9%).
Step B: Preparation of 2-nitro-4, 5-methylenedioxytoluene (11)
To a solution of 10 (19.0 g, 139.6 mmol) in acetic acid (180 mL) was added a solution of fuming HNO 3 (10 mL) in acetic acid (70 mL) dropwise over 30 minutes. The mixture was stirred at ambient temperature for 10 minutes, then poured into a beaker containing ice to give a crystalline precipitate, which was collected by vacuum filtration and washed with water to afford the crude product. Further purification via recrystallization from CH 2 Cl 2 /hexane gave the pure product (16.3 g, 64.4%).
Step C: Preparation of (E)-4,5-methylenedioxy-2-nitro-1-pyrrolidinostyrene (12)
A solution of 11 (15.7 g, 86.74 mmol), N,N-dimethylformamide dimethyl acetal (15.5 g, 130.1 mmol) and pyrrolidine (9.25 g, 130.1 mmol) was heated to 110° C. and stirred for 3 hours under nitrogen. The reaction mixture was cooled, and a mixture of absolute methanol and ethanol (1:1; 250 mL) was added. The product crystallized as a bright red solid. Recovery by suction filtration afforded the product (16.2 g, 71.4%).
Step D: Preparation of 5,6-methylenedioxyindole (13)
To a solution of 12 (15.7 g, 59.92 mmol) in methanol and THF (200 mL, 1:1) was added Raney nickel (1.5 mL) and hydrazine hydrate (3×2.56 mL, 240 mmol) in three equal portions every half hour at ambient temperature under nitrogen. The solution was then heated at 45° C. for two hours. The mixture was cooled to room temperature and the catalyst was removed by filtration through a bed of Celite, then washed three times with methylene chloride. The filtrate was evaporated and the residue dried by azeotroping with toluene (100 mL) to provide a crude oil. Flash silica gel column chromatography eluting with hexane (100%) gradient to ethyl acetate/hexane (30/70%) afforded the title intermediate as an off-white solid (5.1 g, 52.9%).
Step E: Preparation of 2-(4,5-methylenedioxy-1H-indole-3-yl)-3-[5-benzyloxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethyl maleimide (14)
To a solution of 13 (279.0 mg, 1.73 mmol) in THF (35.0 mL) was added lithium hexamethyldisilazide (LiHMDS, 3.46 mL, 3.46 mmol, 1 M in THF) at 0° C. and stirred for 40 minutes. A solution of 6 in THF (20 mL) was added slowly to above mixture, followed by stirring for 20 minutes at 0° C. The mixture was diluted with EtOAc (350 mL), washed with HCl (1 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude mixture. Flash silica gel column chromatography eluting with hexane (100%) gradient to ethyl acetate/hexane (40/60%) afforded the title intermediate as a red solid 0.73 g (45.3%).
Step F: Preparation of 2,3-methylenedioxy-6-benzyloxymethyl-9-benzyloxy-12-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosysl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (15)
To a solution of 14 (650 mg, 0.58 mmol) in DMF (36 mL) was added palladium(II) trifluoroacetate (405 mg, 1.22 mmol), and the reaction was stirred at 80° C. for one hour. The solution was cooled to room temperature and diluted with EtOAc (350 mL), then washed with HCl (1 M), NaHCO 3 , brine (150 mL) and H 2 O (3×150 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel column chromatography eluting with EtOAc/hexane (3:7) afforded 248 mg (38.2%) as a yellow solid.
Step G: Preparation of 2,3-methylenedioxy-6-hydroxymethyl-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (16)
To a solution of 15 (150 mg, 0.1341 mmol) in HOAc (10 mL) was added palladium hydroxide (150 mg). The reaction was shaken under an atmosphere of H 2 (50 psi) at ambient temperature for 60 h. The mixture was filtered through an Acrodisc syringe filter and concentrated in vacuo to give a crude solid. Flash silica gel column chromatography eluting with MeOH/AcOH/EtOAc (12/1/87) afforded 56.2 mg (76.7%) as a yellow solid.
Step H. Synthesis of 2,3-methylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Ib)
To a solution of 16 (30.0 mg, 0.052 mmol) in MeOH (2.0 mL) was added NH 4 OH (4.0 mL). The mixture was stirred at ambient temperature for 3 hours, then concentrated in vacuo to give a crude solid. Flash silica gel column chromatography eluting with MeOH/AcOH/EtOAc (12/1/87) afforded 26.1 mg (91.1%) as a yellow solid.
EXAMPLE 3
Synthesis of 2,3-(isopropylenedioxy)-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Ic)
Step A: Preparation of 4-methyl-2′,2′-dimethyl-1,3-benzodioxole (17)
A mixture of 4-methylcatechol (75.0 g, 604.2 mmol, Aldrich), phosphorous pentoxide (85.8 g, 302.3 mmol) in acetone (200 mL) and toluene (200 mL) was refluxed under nitrogen for 50 hours. The solution was allowed to cool to ambient temperature and diluted with ether (500 mL). The mixture was washed with 2 M NaOH (2×200 mL) and H 2 O (2×200 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude oil. Flash chromatography eluting with hexane (100%) gradient to ether/hexane (1:1) afforded the title intermediate as a colorless oil (82.0 g, 82.7%).
Step B: Preparation of 4-methyl-5-nitro-2′,2′-dimethyl-1,3-benzodioxole (18)
To a solution of 17 (65.0 g, 395.9 mmol) in HOAc (450 mL) was added a solution of fuming HNO 3 (35 mL) in acetic acid (100 mL) over 30 minutes. The mixture was stirred at ambient temperature for 10 minutes, then poured into a beaker containing ice to give a crystalline precipitate which was collected by vacuum filtration and washed with water to afford the crude product (77.1 g, 93.8%).
Step C: Preparation of (E)-4,5-(isopropylenedioxy)-2-nitro-1-pyrrolidinostyrene (19)
A solution of 18 (45 g, 215.1 mmol), N,N-dimethylformamide dimethyl acetal (38.45 g, 322.7 mmol) and pyrrolidine (22.95 g, 322.7 mmol) were heated to 110° C. and stirred for 16 hours under nitrogen. The reaction mixture was cooled, and a mixture of absolute methanol and ethanol (1:1; 600 mL) was added. The product crystallized as a bright red solid. Recovery by suction filtration afforded the product (51.0 g, 81.5%).
Step D: Preparation of 5,6-(isopropylenedioxy)indole (20)
To a solution of 19 (50.0 g, 171.7 mmol) in methanol and THF (400 mL, 1:1) was added Raney nickel (4.0 mL) and hydrazine hydrate (3×7.13 mL, 686.6 mmol) in three equal portions every 30 minutes at ambient temperature under nitrogen. The solution was heated at 45° C. for two hours. The mixture was cooled to room temperature and the catalyst was removed by filtration through a bed of Celite, then washed three times with methylene chloride. The filtrate was evaporated and the residue dried azeotropically with toluene (100 mL) to give a crude oil. Flash silica gel column chromatography eluting with hexane (100%) gradient to ethyl acetate/hexane (30/70%) afforded the title intermediate as an off-white solid, which was futher purified via recrystallization with benzene/petroleum ether (2:8) to give the pure product (15.1 g, 46.2%).
Step E: Preparation of 3-[(4,5-isopropylenedioxy-1H-indol-3-yl)]-4-[5-benzyloxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethyl maleimide (21)
To a solution of 20 (2.27 mg, 12.02 mmol) in THF (150 mL) was added lithium hexamethyldisilazide (LiHMDS, 12.02 mL, 12.02 mmol, 1 M in THF) at 0° C. and the solution was stirred for 40 minutes. A solution of 6 (5.0 g, 4.81 mmol) in THF (50 mL) was added slowly to the above mixture, followed by stirring for 20 minutes at 0° C. The mixture was diluted with EtOAc (400 mL), then washed with HCl (1 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude mixture. Flash silica gel column chromatography eluting with hexane (100%) gradient to ethyl acetate/hexane (40/60%) afforded the title intermediate as a red solid (3.02 g, 54.71%).
Step F: Preparation of 2,3-isopropylenedioxy-6-benzyloxymethyl-9-benzyloxy-12-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (22)
To a solution of 21 (1.60 g, 1.39 mmol) in DMF (85 mL) was added palladium(II) trifluoroacetate (657 mg, 2.93 mmol), and the solution was stirred at 80° C. for two hours. The solution was cooled to room temperature and diluted with EtOAc (250 mL), then washed with HCl (1 M), NaHCO 3 , brine (150 mL), and H 2 O (3×150 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel column chromatography eluting with EtOAc/hexane (3:7) afforded 1.02 g (63.7%) as a yellow solid.
Step G: Preparation of 2,3-isopropylenedioxy-6-hydroxymethyl-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (23)
To a solution of 22 (280 mg, 0.244 mmol) in HOAc (12 mL) was added palladium hydroxide (100 mg). The reaction was shaken under an atmosphere of H 2 (50 psi) at ambient temperature for 60 h. The mixture was filtered through an Acrodisc syringe filter and concentrated in vacuo to give a crude solid. Flash silica gel column chromatography eluting with MeOH/AcOH/EtOAc (12/1/87) afforded 135 mg (91.4%) as a yellow solid.
Step H: Synthesis of 2,3-isopropylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Ic)
To a solution of 23 (100.0 mg, 0.165 mmol) in MeOH (7.0 mL) was added NH 4 OH (6.0 mL). The mixture was stirred at ambient temperature for 2 hours, then concentrated in vacuo to give a crude solid. Flash silica gel column chromatography eluting with MeOH/HOAc/EtOAc (12/1/87) afforded 81.0 mg (85.3%) as a yellow solid.
EXAMPLE 4
Synthesis of 2,3-dimethoxy-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Id)
Step A: Preparation of 3-[(4,5-dimethoxy-1H-indol-3-yl)]-4-[5-benzyloxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethyl maleimide (24)
To a solution of 5,6-dimethoxyindole (441 mg, 2.49-mmol) in THF (50 mL) was added lithium hexamethyldisilazide (LiHMDS, 4.98 mL, 4.98 mmol, 1 M in THF) at 0° C. and the solution was stirred for 40 minutes. A solution of 6 (2.25 g, 2.16 mmol) in THF (30 mL) was added slowly to the above mixture, followed by stirring for 20 minutes at 0° C. The mixture was diluted with EtOAc (250 mL), then washed with HCl (1 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give a crude mixture. Flash silica gel column chromatography eluting with hexane (100%) gradient to ethyl acetate/hexane (60/40%) afforded the title intermediate as a red solid (2.79 g, 98.6%).
Step B: Preparation of 2,3-dimethoxy-6-benzyloxymethyl-9-benzyloxy-12-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7dione (25)
To a solution of 24 (1.50 g, 1.32 mmol) in DMF (60 mL) was added palladium(II) trifluoroacetate (923 mg, 2.77 mmol), and the solution was stirred at 80° C. for two hours. The solution was cooled to room temperature and diluted with EtOAc (250 mL), then washed with HCl (1 M), NaHCO 3 , brine (150 mL), and H 2 O (3×150 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel column chromatography eluting with EtOAc/hexane (3:7) afforded 769 mg (51.4%) as a yellow solid.
Step C: Synthesis of 2,3-isopropylenedioxy-9-hydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (Id)
To a solution of 25 (600 mg, 0.529 mmol) in HOAc (25 mL) was added palladium hydroxide (600 mg). The reaction was shaken under an atmosphere of H 2 (50 psi) at ambient temperature for 60 hours in a Parr shaker. The solution was filtered through an Acrodisc syringe filter and concentrated in vacuo to provide a solid. The solid was dissolved in MeOH (150 mL) and aqueous NH 4 OH (50 mL). The mixture was stirred at ambient temperature for 1.5 hours, then concentrated in vacuo to provide the crude product. Flash silica gel chromatography eluting with MeOH/HOAc/EtOAc (12/1/87) afforded 166 mg (60.0%) of desired product as a yellow solid.
EXAMPLE 5
Synthesis of 2,3-ethylenedioxy-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (IIa)
Step A: Preparation of 3-bromo-4-(4,5-ethylenedioxy-1H-indol-3-yl)-N-benzyloxymethylmaleimide (26)
To a solution of 4 (2.1 g, 12.0 mmol) in benzene (100 mL) was added methylmagnesium iodide (4.4 mL, 13.19 mmol, 3 M in ether) at 0° C. After stirring for one hour, a solution of N-benzyloxymethyl-3,4-dibromomaleimide (4.5 g, 12.0 mmol) in benzene (30 mL) and THF (50 mL) was added slowly. The reaction mixture was stirred at 0° C. for 30 minutes and then warmed to room temperature for one hour. The mixture was diluted with EtOAc (250 mL), then washed with HCL (100 mL, 0.3 M), NaHCO 3 (100 mL) and H 2 O (100 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography, eluting with a hexane gradient to EtOAc/hexane (3:2) afforded the title intermediate as a yellow solid (2.83 g, 50.5%).
Step B: Preparation of 3-bromo-4-[4,5-ethylenedioxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethylmaleimide (27)
To a solution of 26 (2.7 g, 5.75 mmol), 2,3,4,5-tetra-O-benzyl-D-glucopyranose (9.33 g, 17.26 mmol) and triphenylphosphine (4.53 g, 17.26 mmol) in THF (150 mL) at −78° C. was added diisopropylazodicarboxylate (DIAD) (3.4 mL, 17.26 mmol) dropwise. Stirring was continued at −78° C. for 3 hours, then the solution was warmed to 0° C. with the aid of a ice-water bath and stirring continued for 2 hours. The mixture was diluted with EtOAc (300 mL), then washed with HCL, brine and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography, eluting with a toluene gradient to toluene/EtOAc (25:1) afforded the title intermediate as a yellow solid 3.15 g (55.3%).
Step C: Preparation of 3-(5-benzyloxy-1H-indol-3-yl)-4-[4,5-ethylenedioxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucoyranosyl)-1H-indol-3-yl]-N-benzyloxymethylmaleimide (28)
To a solution of 5-benzyloxyindole (1.52 g, 6.8 mmol) in THF (70.0 mL) was added lithium hexamethyldisilazide (LiHMDS, 6.8 mL, 6.8 mmol, 1 M in THF) at 0° C., and the solution stirred for 30 minutes. A solution of 27 in THF (80 mL) was added slowly to the above mixture, followed by stirring for 30 minutes at 0° C. The mixture was diluted with EtOAc (300 mL), then washed with HCl (1 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to give the crude product. Flash silica gel chromatography eluting with a hexane (100%) gradient to EtOAc/hexane (2:3) afforded the title intermediate as a red solid 1.62 g (52.6%).
Step D: Preparation of 2,3-ethylenedioxy-6-benzyloxymethyl-9-benzyloxy-13-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (29)
To a solution of 28 (1.0 g, 0.882 mmol) in DMF (50 mL) was added palladium(II) trifluoroacetate (615.4 mg, 1.85 mmol), and the solution was stirred at 80° C. for 1 hour. The solution was cooled to room temperature and diluted with EtOAc (350 mL), then washed with HCl (1 M), NaHCO 3 , brine (150 mL) and H 2 O (3×150 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography eluting with EtOAc/hexane (3:7) afforded 471.0 g (47.2%) of desired product as a yellow solid.
Step E: Synthesis of 2,3-ethylenedioxy-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (IIa)
To a solution of 29 (350 mg, 0.309 mmol) in HOAc (12 mL) was added palladium hydroxide (350 mg). The reaction was shaken under an atmosphere of H 2 (50 psi) at ambient temperature for 62 hours in a Parr shaker. The solution was filtered through an Acrodisc syringe filter and concentrated in vacuo to provide a solid. The solid was dissolved in MeOH (200 mL) and aqueous NH 4 0H (10 mL). The mixture was stirred at ambient temperature for 3 hours, then concentrated in vacuo to provide the crude product. Flash silica gel chromatography eluting with MeOH/HOAc/EtOAc (12/1/87) afforded 164 mg (94.5%) of desired product as a yellow solid.
EXAMPLE 6
Synthesis of 2,3-methylenedioxy-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (IIb)
Step A: Preparation of 3-bromo-4-(5,6-methylenedioxy-1H-indol-3-yl)-N-benzyloxymethylmaleimide (30)
To a solution of 13 (2.7 g, 16.75 mmol) in benzene (100 mL) was added methylmagnesium iodide (6.14 mL, 18.42 mmol, 3 M in ether) at 0° C. The solution was stirred for 1 hour, and then a solution of N-benzyloxymethyl-3,4-dibromomaleimide (6.28 g, 16.75 mmol) in benzene (30 mL) and THF (50 mL) was added slowly. The reaction mixture was stirred at 0° C. for 30 minutes, then warmed to room temperature and stirred for 1 hour. The mixture was diluted with EtOAc (200 mL), then washed with HCL (100 mL, 0.3 M), NaHCO 3 (100 mL) and H 2 O (100 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Crystallization of the crude oil with MeOH afforded the title intermediate as a yellow solid (2.92 g, 38.2%).
Step B: Preparation of 3-bromo-4-[5,6-methylenedioxy-1-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethylmaleimide (31)
To a solution of 30 (2.3 g, 5.05 mmol), 2,3,4,5-tetra-O-benzyl-D-glucopyranose (8.2 g, 15.2 mmol) and triphenylphosphine (4.0 g, 15.2 mmol) in THF (150 mL) at −78° C. was added diisopropylazodicarboxylate (DIAD) (2.98 mL, 15.2 mmol) dropwise. The solution was stirred at −78° C. for 3 hours, then warmed to 0° C. and stirred further for 2 hours. The mixture was diluted with EtOAc (300 mL), then washed with HCl, brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography eluting with a toluene gradient to toluene/EtOAc (25:1) afforded the title intermediate as a yellow solid 3.05 g (61.8%).
Step C: Preparation of 3-(5-benzyloxy-1H-indol-3-yl)-4-[5,6-methylenedioxy-1-(2,3,4,5tetra-O-benzyl-β-D-glucopyranosyl)-1H-indol-3-yl]-N-benzyloxymethylmaleimide (32)
To a solution of 5-benzyloxyindole (822.0 mg, 3.68 mmol) in THF (35 mL) was added lithium hexamethyldisilazide (LiHMDS, 3.68 mL, 3.68 mrol, 1 M in THF) at 0° C., and the resulting solution was stirred for 40 minutes. A solution of 31 in THF (20 mL) was added slowly to the above mixture, followed by stirring for 20 minutes at 0° C. The mixture was diluted with EtOAc (300 mL), then washed with HCl (1 M), NaHCO 3 , brine, and H 2 O. The organic layer was dried over Na 2 SO 4 , filtered and concentrated to provide the crude product. Flash silica gel chromatography eluting with a hexane (100%) gradient to EtOAc/hexane (2:3) afforded the title intermediate as a red solid (1.56 g, 91.2%).
Step D: Preparation of 2,3-methylenedioxy-6-benzyloxymethyl-9-benzyloxy-13-(2,3,4,5-tetra-O-benzyl-β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (33)
To a solution of 32 (1.45 g, 1.294 mmol) in DMF (75 mL) was added palladium(II) trifluoroacetate (904 mg, 2.72 mmol), and the solution was stirred at 80° C. for 1 hour. The solution was cooled to room temperature and diluted with EtOAc (350 mL), then wash with HCl (1 M), NaHCO 3 , brine, and H 2 O (3×150 mL). The organic layer was dried over Na 2 SO 4 , filtered and concentrated. Flash silica gel chromatography eluting with EtOAc/hexane (3:7) afforded 1.05 g (72.6%) of the desired product as a yellow solid.
Step E: Synthesis of 2,3-methylenedioxy-9-hydroxy-13-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (IIb)
To a solution of 33 (300 mg, 0.268 mmol) in HOAc (14 mL) was added palladium hydroxide (300 mg). The reaction was shaken under an atmosphere of H 2 (50 psi) at ambient temperature for 60 hours in a Parr shaker. The solution was filtered through an Acrodisc syringe filter and concentrated in vacuo to provide the crude product as a solid. The solid was dissolved in MeOH (20.0 mL) and aqueous NH 4 OH (30.0 mL), stirred at ambient temperature for 2 hours, and then concentrated in vacuo to provide the crude product. Flash silica gel chromatography eluting with MeOH/HOAc/EtOAc (12/1/87) afforded 92.0 mg (62.7%) as a yellow solid.
EXAMPLE 7
Typical Experimental Procedure for the Synthesis Compounds with the Following General Formula
To a solution of the anhydride YPX-2-21 (32 mg, 0.05834 mmol) in DMF (1.8 mL) was added appropriate hydrazide or amine [0.5834 mmol] (see Table 1). The reaction was placed under atmosphere of nitrogen at 95° C. for 2 h. The mixture was diluted with water (12 mL) and stirred at 0° C. for two h. The precipitate was filtered and washed with water and ethyl ether to obtain the product (see Table 1 for yields).
TABLE 1
Modofication at the Imide Ring
S. No.
R
Yield %
1
—NH 2
72
2
27.4
3
68
4
76
5
87.2
6
90.2
7
66.4
8
27.4
9
52
10
84
11
100
12
69.4
13
70.4
14
54
15
67.6
16
—CHO
76
EXAMPLE 8
Biological Evaluation
a.) Topoisomerase I assay. Reaction buffer (10.3 μL H 2 O, 2.0 μL 10×buffer, 1.5 μL 100 μM MgCl 2 , and 3.2 μL 500 mM KCl) was prepared and kept on ice. 10×Buffer was prepared by mixing 2 mL 2M Tris pH 7.5, 15.3 μL 10% DTT, 100 μL 0.5 M EDTA, 75 μL 20 mg/mL BSA, and 7.935 μL H 2 O. Test poisons were prepared in DMSO at such concentrations that the final incubation mixture was 5% DMSO. DNA mix was prepared by dissolving 55 mL of pHOT1 DNA solution (0.25 μg/μL) with 715 μL reaction buffer. Topo I mix was prepared by mixing 14 μL of Topo I solution (2 units/μL) with 266 μL of reaction buffer. Proteinase K solution was prepared fresh as 10 mg/mL in 1% SDS. Gel loading buffer was prepared by dissolving 1 mg bromophenol blue in 100 μL H 2 O, then adding 900 μL 50% glycerol. Topotecan (Camptosar) and 3,9-dihydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione 11 (ALS-007) were used as positive controls.
The assay was conducted as follows. DNA mix (14 μL) was added to sample tubes containing 1 μL of test poison solution and stored on ice. Next, 5 μL of Topo I mix was added, the solution was mixed with the pipettor, then incubated with gentle rocking in a 37° C. water bath for 30 minutes. The reactions were stopped via addition of 2 μL of proteinase K solution, and incubation was continued for another 30 minutes, then placed on ice. 2.2 μL of 5 M NaCl and 75 μL of EtOH were added to the tubes, the tubes were vortexed briefly, then placed on dry ice for 1 hour. The DNA was pelleted by centrifugation at 16,000×g for 10 minutes at 4° C. EtOH was removed from each tube using a gel loading pipette tip, and the DNA pellet was resuspended in 18 μL of reaction buffer and 2 μL of gel loading buffer. The samples were vortexed briefly, then spun for 15 seconds in a micro-centrifuge to force all the liquid to the bottom of the tubes. The samples were loaded onto a 1% agarose gel made with 1×TBE containing 2 μg/mL chloroquine. The gels were run at 35 V for 15 hours in 1×TBE. Gels were stained with 0.5 μg/mL ethidium bromide in 1×TBE for 1 hour, then destained for 30 minutes in H 2 O. Gels were photographed with a digital camera, and the digitized images analyzed using NIH software. IC 50 values were determined by comparing supercoiled DNA band density (negative controls containing 5 μL reaction buffer in place of Topo I mix) with the supercoiled DNA bands remaining in the test samples.
TABLE 2
Poisoning of Human Topoisomerase I by Indolocarbazole Analogues
Agent
IC 50 (μM)
Topotecan
31.3
ALS-007
20.9
9
3.9
16
3.6
Ia
5.4
lb
3.6
23
130
Ic
8.1
Iia
>400
Iib
>400
b.) In vitro Cytotoxicity Assay. 96-Well tissue culture cluster plates were seeded with 100 μL of cell suspension (5×10 3 cells/mL), and incubated overnight for cell anchorage and acclimation. Cells were propagated under sterile conditions in RPMI 1640 or DMEM with 10% fetal bovine serum, 2 mM L-glutamine, and sodium bicarbonate (complete medium), and incubated at 37° C. The test compounds were prepared in DMSO and then diluted in complete media. A range of eight concentrations was used for each test drug to establish cytotoxicity, with eight replicates for each concentration. All dosing was conducted using a Biomek 2000 robotic liquid handler. The plates were incubated at 37° C. with 5% CO 2 and 95% relative humidity. The data were analyzed for cytotoxicity using the MTS assay 3–5 days (depending upon the growth rate of the cell lines) after commencement of treatment. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium is bio-reduced by viable cells into a soluble formazan that absorbs at 490 nm, allowing simple spectrophotometric measurement of viable cells. Topotecan (Camptosar) and 3,9-dihydroxy-12-(β-D-glucopyranosyl)-6,7,12,13-tetrahydroindolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione 11 (ALS-007) were used as positive controls.
c.) MTS Assay. A solution of 40 μL of MTS/PES solution (purchased from Promega Corporation) was added to each well, and incubated for one to four hours. The absorbance of formazan in each monolayer was measured at 490 nm on a Coulter microplate reader. The data were processed in a spreadsheet program to provide a dose-response curve, allowing determination of the IC 50 .
TABLE 3
Growth-Inhibitory Activity Against Various Human Tumor Cell Lines
IC 50 (μM)
Agent
HT-29 Colon
DU-145 Prostate
OVCAR-3 Ovarian
Topotecan
0.533
0.030
<0.003
ALS-007
9.96
0.338
<0.01
9
>10
0.718
<0.01
16
>10
0.549
<0.01
Ia
>10
0.845
<0.01
Ib
>10
0.460
<0.01
23
>10
3.52
0.043
Ic
>10
2.36
0.036
As illustrated by the results in Table 2, in a side-by-side comparison, the compounds disclosed in this invention provide a stronger poisoning effect against human Topo I than the control compounds, topotecan (a clinically-used Topo I poison/antitumor agent) and ALS-007, an experimental indolocarbazole previously disclosed 11 . Additionally, in a side-by-side comparison, the compounds disclosed in this invention exhibit in vitro cytotoxicity profiles against a series of three human tumor cell lines similar to the two control compounds (Table 3).
CITATIONS
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20. Blair, J. B.; Kurrasch-Orbaugh, D.; Marona-Lewicka, D.; Cumbay, M. G.; Watts, V. J.; Barker, E. L.; Nichols, D. E. J. Med. Chem. 2000, 43, 4701–4710. | The present invention relates to anti-tumor compounds, compositions and methods. In particular, the invention relates to indolocarbazole analogues of the following general formulas that inhibit topoisomerase I activity | 2 |
BACKGROUND OF THE INVENTION
This invention relates to signaling devices which are used to indicate the opening of a door in a retail establishment. There are many devices which have been used to indicate opening and closing of doors. These include bells, either mounted on the door or positioned to be engaged by the opening motion of the door, switches have also been provided in the door frame which are activated by movement of the door to open or close electrical circuits.
SUMMARY OF THE INVENTION
The door chime according to the present invention is a self-contained, electrically actuated device which forms a part of an advertising display that is adhesively secured to the door. A principal feature of the invention is the provision of a self-contained, audio signal unit which provides a signal whenever the door is moved.
A further feature of the invention is the provision of a predetermined time delay to allow the door to close without a continuous signal.
Another feature of the invention is the provision of a time controlled audio signal that provides a predetermined signal in the time delay interval.
Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of the advertising display in which the audio signal assembly according to the invention is mounted.
FIG. 2 is a view of the battery and circuit board for the audio signal assembly.
FIG. 3 is a circuit diagram of the printed circuit assembly shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The advertising display case 10 is shown in our co-pending design application Ser. No. 07/020,656, filed on Mar. 2, 1987, entitled Door Tone. The display case generally includes a housing 12 having a compartment 14 in the upper end in which the audio signal assembly 16 is mounted. The housing includes a panel 18 on which advertising may be provided and also a panel 20 on the compartment to indicate entry or exit instructions. The case is mounted on the inside of a door by means of adhesive strips 21 provided on the back of the side support members 24. If the case is mounted on a glass door advertising can also be placed on the back of panel 18 and housing 20.
In accordance with the invention, the audio signal assembly 16, as seen in FIG. 2, includes a printed circuit board 26 and a battery 22. The circuit board 26 includes an on and off switch SW1 for activating the signal circuit, a motion switch SW2 which responds to the motion of the door and a piezoelectric audio indicator BUZ1. SW1 is closed to activate the circuit which is then responsive to the motion switch SW2. On movement of the door, SW2 closes to trigger a dual precision monostable multivibrator U1A-U1B (CD4538B National Semi-Conductor). When triggered, the first half of the multivibrator U1A will operate for a fixed time period during which time the circuit ignores further motion inputs. The second half of the multivibrator, U1B, is triggered simultaneously for a time period during which the pulse generator U2 may operate and thus determines the number of tones produced on each activation of the circuit. The pulse generator U2 (LM555 National Semi-Conductor) is a timer configured to generate pulses, generally two output pulse cycles, during the preset time period. The pulses are sent to the piezoelectric audio indicator BUZ1 (KPE-133 Kingstate) to provide two short sound tones.
More specifically and referring to FIG. 3, a schematic circuit diagram is shown for the electrical circuit. The circuit is powered by a 9-volt battery 22 which is connected to terminals B1 and B2 as described above. Switch SW1 is provided as a means for interrupting power when the device is not in use. The switch circuit is protected by means of a diode D1 to prevent damage to the circuit if an attempt is made to install the battery in reverse polarity position. Means in the form of a capacitor C2 is provided to support the power supply voltage during short pulses of high current, such as when the tone generator BUZ1 is activated.
The circuit is activated upon movement of the door by means of a motion sensitive switch SW2 which is of the type having a mercury bead positioned in a sealed tube with contacts at one end which are closed by the movement of the bead into the end of the tube. Switch SW2 is held in a horizontal position by locating tabs molded as part of the case 10. Terminal 11 of the first half of the multivibrator U1A is maintained at a voltage V+ by a resistor R8 until the switch SW2 closes in response to motion of the door. Upon closing terminal U1-12 is shorted to common. The first half of the multivibrator U1A is configured to respond to the falling edge of a trigger pulse via terminal 11. When triggered, terminal 10 will go high (logic 1) for a fixed time period equal to the resistance R4 times the capacitor C4, (i.e. 1.5E6 * 10E-6=15 seconds). This establishes the time period during which the circuit ignors further motion of the mercury bead in the switch SW2.
Means is provided to interrupt power to all portions of the circuit following the first half of the multivibrator U1A in order to minimize battery drain when the circuit is in the standby mode. This is accomplished by means of a semi-conductor Q2 which is driven off of terminal U1A-10 via resistence R9. The semi-conductor Q2 provides a path to common for all circuits associated with timer U2 and semi-conductor Q1.
The time period during which the pulse generator U2 may operate is determined by means of the second half of the multivibrator U1B. In this regard the multivibrator U1B is configured to respond to the leading edge of a trigger pulse via terminal 4 from multivibrator U1A terminal 10. Multivibrator U1B terminal 7 goes low (logic 0) for a time period determined by resistence R3 times capacity C3 (470E3 * 1E-6=0.47 seconds). During this period of time two tones from tone generator BUZ1 are initiated.
The pulse generator U2 is a timer configured to generate pulses. The pulse generator is enabled to cycle whenever multivibrator U1B-7 is low (logic 0) and is disabled, via diode D4, whenever U1B-7 is high (logic 1). The pulse generator U2 can, therefore, produce pulses during the 0.47 second period of the multivibrator U1B operation. Although it has been described as producing two output pulse cycles in this time period, it should be noted that this can be adjusted according to the requirements of the user.
The tone generator BUZ1 is a piezoelectric audio indicator of the externally excited type. The tone generator BUZ1 is driven by a semi-conductor Q1 which together comprise an oscillator operating at 3,600 hertz (cycles per second). This circuit is enabled to operate whenever the output of pulse generator U2 (terminal 3) is high (logic 1). This circuit is disabled whenever pulse generator U2 (terminal 3) is low (logic 0) via resistence R7. Diode D3 is provided to prevent high voltage spikes produced by the tone generator BUZ1 from exceeding the reverse break down voltage of the semi-conductor Q1's base-emmitter function. | An audio signal device for a door mounted advertising display, the device includes a signal unit, a battery connected to said signal unit, the unit including a tone generator, a pulse generator connected to control the tone generator, a timer connected to control the time of operation of the pulse generator, and a motion switch connected to energize the timer in response to the motion of the door, the timer further including a circuit for preventing reactivation of the timer for a predetermined period of time. | 6 |
This is a continuation of application Ser. No. 08/098,530, filed on Jul. 28, 1993, now U.S. Pat. No. 5,419,096.
FIELD OF THE INVENTION
This invention relates to packages for food products which are adapted for gaseous exchange to extend the life of the food product. Particularly, this invention relates to such packages, packaging methods, and packaging apparatus adapted to contain relatively large meat products such as whole chickens, roasts, or other large meat products.
BACKGROUND OF THE INVENTION
Domed meat packages have been used in the past to contain large cuts of meats such as chickens or roasts. However, these packages have suffered from a number of drawbacks.
It is desirable to control the atmosphere within the meat package to delay the aging of the food product and to extend its shelf life in the supermarket. For example, by providing low oxygen environments, the shelf life of the food product can be extended from a few days to as long as two weeks or more perhaps.
In order to make the customer feel comfortable with the food packaging, the customer should be able to view a substantial portion of the food product. In order to maintain a desired atmosphere around the package, a package which is somewhat larger than the food product is required. However, with a large, relatively heavy meat product it is difficult to allow for spacing around the food product and yet maintain the product in an attractive fashion within the container.
Moreover, since the consumer would normally desire that he or she be able to see the food product, the spacing becomes visible to the consumer. The consumer may believe that the package is too large and wasteful. Moreover, if the product is substantially larger than the food product, the food product may move around during transportation and handling, and the package itself may be indented or otherwise damaged.
In the past, deep draw packages may have been used for this type of packaging. However, deep draw packages become difficult to form at large sizes and may experience significant deformation of the packaging material. These packages are particularly susceptible to the formation of thin spots and to the indenting and collapsing of the corner regions.
Thus, the present applicant has appreciated that it would be desirable to form a domed package rather than to use the deep draw plastic forming technique. With the domed package, the product may protrude above the sealing flanges that connect the upper and lower package portions. It is also possible to form the package portions from different materials adapted to particular packaging needs. For example, it may be desirable to form the bottom portion out of foam material and the top out of transparent plastic.
The requirements of a relatively large package made of relatively rigid packaging material seem to be incompatible with the necessity of extra space within the package for conventional gas exchange techniques to extend the shelf life. Thus, most conventional, large food products are simply overwrapped with plastic wrap, and the supermarket endures the additional costs that result from meat loss.
Therefore, it would be highly desirable to provide a relatively rigid domed food package, packaging method, and packaging apparatus which allows relatively large cuts of meat to be efficiently packaged in a desirable gas environment.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, an apparatus for facilitating gas exchange packaging includes a reciprocatable device for displacing a preformed upper package portion from a first position in contact with a lower package portion to a second position in spaced separation from a preformed lower package portion. The upper and lower package portions are thereby completely separated from one another to permit gas exchange through the opening created between upper and lower package portions. The reciprocatable device is reciprocatable from the second position back to the first position to allow the upper package portion to again rest in abutment on the lower package portion after gas exchange has been accomplished.
In accordance with another aspect of the present invention, a method for facilitating gas exchange packaging includes the step of positioning a lower preformed package portion in an apparatus capable of supporting the lower preformed package portion. The upper preformed package portion is positioned atop the lower preformed package portion. The upper preformed package portion is raised over the lower package portion using the reciprocatable device to completely remove the upper package portion from the lower package portion. The gas within the package is exchanged with a desired atmosphere through the opening created by the reciprocatable device. The reciprocatable device reciprocates downwardly to allow the upper package portion to again rest in abutment on the lower package portion.
In accordance with still another aspect of the present invention, an apparatus for facilitating gas exchange packaging comprises a reciprocatable device for displacing a preformed upper package portion in spaced separation from a lower package portion to permit gas exchange in one position of the device. A reciprocatable device is reciprocatable to a second position to allow the upper package portion to rest in abutment on the lower package portion. A plurality of guide portions are adapted to guide the upper package portion into a desired position with respect to the lower package portion. The guide portions control the extent of upward reciprocation of the reciprocatable device.
In accordance with another aspect of the present invention, an apparatus for facilitating gas exchange packaging includes a reciprocatable device for displacing a preformed upper package portion in spaced separation from a preformed lower package portion to permit gas exchange in one position of the device. The reciprocatable device is reciprocatable to a second position to allow the upper package portion to rest in abutment on the lower package portion. A bar pushes the device downwardly to the second position and a package sealing device reciprocates with the bar.
In accordance with another aspect of the present invention, a method for facilitating gas exchange packaging includes the step of positioning a lower preformed package portion in an apparatus capable of supporting that portion. An upper preformed package portion is positioned atop a reciprocatable device which maintains the upper package portion in spaced displacement over the lower package portion. Gas within the package is exchanged with a desired atmosphere through the opening created by the reciprocatable device. The reciprocatable device is simultaneously pressed downwardly to cause the upper and lower package portions to come into abutment and contact the upper package portion with a sealing device.
Still another aspect of the present invention involves a method for facilitating gas exchange packaging that includes the step of positioning a lower preformed package portion in an apparatus capable of supporting the lower preformed package portion. An upper preformed package portion is positioned atop a reciprocatable device which maintains the upper package portion in spaced displacement over the lower package portion. Gas within the package is exchanged with a desired atmosphere through the opening created by the reciprocatable device. The reciprocatable device reciprocates downwardly to a second position to allow the upper package portion to rest in abutment on the lower package portion. The guide members guide the upper package portion into position. The guide members also control the upward movement of the reciprocatable device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a-1c are a simplified cross-sectional view showing three stages in one embodiment of a packaging process in accordance with the present invention;
FIG. 2 is a partial, enlarged, top plan view of the package shown in FIG. 1a;
FIG. 3 is a partial, enlarged, top plan view of the package shown in FIG. 1b;
FIG. 4 is an enlarged, cross-sectional view of one embodiment of a packaging apparatus for accomplishing the process steps shown in FIG. 1b;
FIG. 5 is an enlarged, cross-sectional view of the packaging apparatus of FIG. 4, shown in position to accomplish the process steps shown in FIG. 1c; and
FIG. 6 is an enlarged, top plan view of another embodiment of the package shown in the position illustrated in FIG. 1b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing wherein like reference characters are used for like parts throughout the several views, a packaging process for packaging a large meat product "A" is shown in FIG. 1 and includes the steps a, b, and c. In step a, the food product "A" is shown contained within a dish-shaped plastic package portion 10 which is supported by a peripheral flange 12 on a member 14.
The package portion 10 may be formed of a variety of conventional materials including any known plastic packaging material. In many instances, it may be desirable to form the lower package portion 10 of molded foamed plastic so that the package portion will be relatively rigid.
Referring to FIG. 1, step b, an upper package portion 18 is shown in spaced relation to the lower package portion 10 over the food product "A". The package portion 18 is domed and includes a peripheral flange 20. Like the package portion 10, the upper package portion 18 may be formed of a variety of conventional plastic materials. However, in many instances, it may be desirable to form the upper package portion 18 out of relatively rigid, molded transparent plastic material. This allows the food product "A" to be viewed within the food package. Advantageously, both the portions 10 and 18 are preformed of relatively rigid, molded plastic material.
As shown in FIG. 1, step c, the upper and lower package portions 18 and 10 may be joined along their peripheral flanges 20 and 12 by an apparatus 22 which presses the flanges 20 of the portion 18 downwardly onto the flanges 12 of the package portion 10. If desired, the apparatus 22 may be a heat seal machine which causes heat sealing of the juxtaposed flange portions thereby connecting the materials.
The advantage of holding the upper domed portions 18 in spaced juxtaposition with the lower portion 10 is that the gaseous environment within the package may be transformed prior to the sealing step c shown in FIG. 1. For example, the air inside the package may be exhausted, and a desired gas may be supplied in its place. The desired gas may be one which is relatively low in oxygen content so that the shelf life of the food product may be extended. For example, the gas may be relatively higher in either carbon dioxide and/or nitrogen than normal atmospheric air in order to prevent or diminish the oxidation processes that shorten the life of the meat product "A".
As shown in FIG. 2, the lower package portion 10 may be maintained in a desired arrangement by a set of two pairs of opposed guides 24. Each of the guides 24 is arranged in a substantially tangential arrangement to the curved sides of the lower package portion 10 so as to abut with the sealing region 26. The sealing region 26 provides the point of attachment to the upper package portion 18. It can also be seen in FIG. 2 that the lower package portion 10 may include an outwardly extending flange portion 28 on either of two opposed ends of the package 10. While the package 10 shown in FIG. 2 has an oblong configuration, the cross-sectional configuration of the package may assume one of a variety of different shapes.
FIG. 3 shows the positioning of the upper package portion 18 over the lower package portion 10. The upper package portion 18 includes a pair of opposed bluntly pointed end flanges 34 which interact with and are constrained between each set of guides 24. The outwardly extending flange portions 34 extend over the tubes 30 such that the tubes 30 do not generally guide the positioning of the upper package portion 18 in the horizontal plane. This accomplished substantially by the guides 24. In the regions 36, the flanges 34 extend past the edges 32 of the flanges 28 so that there is a region of overhang of the flange 34 over the lower package portion 10.
FIG. 4 shows a packaging machine for achieving the package operation shown in FIG. 1b. In order to illustrate that a variety of package shapes may be utilized, the package 38 shown in FIG. 4 is of a slightly different shape than the package shown in FIG. 1. In particular, the lower package portion 10 is deeper than the package portion 10 shown in FIG. 1, and the abruptness of both the lower and the upper package portions 18 and 10 is greater in the embodiment shown in FIG. 4.
The lower package portion 10 rests in a conforming tray 40 which conforms to its outside configuration and supports the flange 12. The upper package portion 18 has its flange portion 36 resting atop the filling tube 30.
The filling tube 30 is reciprocal up and down within a slot 42. However, the extent of its upward extension is controlled by the overhanging edge 44 of the adjacent guide 24. Each tube 30 includes an outer cylinder 30a and an inner cylinder 30b.
The outer cylinder 30a includes a set of "O" rings 46 which prevent leakage around the tube 30. A pin 48 is provided to control the extent of downward movement of the tube 30 and to prevent its rotation about its lengthwise axis. Within the center of the tube 30 is a bore 50 which is capable of conveying gas to or from the interior of the package to or from the passageway 52. Thus, gas may pass via the passageway 52 to or from the interior of the package shown in the configuration of FIG. 4.
A pressurized gas supply passageway 72 is connected to a source (not shown) of pressurized gas. When desired, pressurized gas may be communicated via the passageway 72 to act on the lower end of the outer cylinder 30a. This causes the tube 30 to move to its upper position shown in FIG. 4.
Juxtaposed over the upper package portion 18 is a pusher bar 54 and a sealing bar 56. The sealing bar 56 may be a conventional heat sealing bar which heat seals the flanges of the upper package portion 18 to those of the lower package portion 10.
The vacuum chamber cover 90 seals to the lower chamber 92 through inner and outer peripheral seals 94 and 96 and the abutment of gasket 98 on the lower chamber 92. A valved passage 100 is provided for pulling a vacuum inside the chamber defined by the cover 90.
FIG. 6 shows an alternate embodiment in which a gas exchange system is provided on the upper package portion 18. The gas exchange portion 58 is constructed generally in accordance with the teaching of applicant's co-pending patent application Ser. No. 08/064,700, filed May 20, 1993, hereby expressly incorporated by reference herein. The portion 58 includes one or more holes 60 formed in the package portion 18. These holes are covered by a first circular plastic film layer 62 which may be permeable to atmospheric air. The layer 62 is sealed to the package portion 18 at 64. Attached over the portion 62 is an upper fluid impermeable plastic film 66 which is sealed at 68 to the upper package portion 18. When desired, the layer 66 may be peeled away to allow gas exchange through the lower layer 62 via the holes 60.
The method and apparatus of the present invention may be implemented in the following fashion. The lower package portion 10, loaded into the conforming tray 40, is supported by its flanges 12. Then a meat product "A", if not already loaded, may be loaded inside the package portion 10. Next, the relatively rigid top or upper portion 18 is aligned over the lower package portion 10 but resting on the top of the filling tubes 30 as shown in FIG. 4.
Initially, the air within the package is exhausted through both the passage 100 and the bore 50 to the passageway 52. Then, with the passage 100 closed, a desired gaseous environment is passed through the passageway 52 and the bore 50 into the package. This gaseous environment may be one which is relatively poor in its concentration of oxygen and relatively higher (with respect to normal ambient atmosphere) with respect to its carbon dioxide and/or nitrogen content. The result of such an environment is to extend the shelf life of a meat product. This is because the presence of oxygen causes the meat product to age and discolor.
After the desired environment has been established, the gas filling tubes 30 are pushed downwardly by the pusher bar 54 into their passageways 42 until the pins 48 engage the top of the slots 80. In this position, shown in FIG. 5, the upper package portion 18 is in abutment with the lower package portion 10. At this point, the sealing regions 26 are likewise in abutment. The package is thereafter sealed along the regions 26 of the upper and lower package portions 10 and 18 to provide an air tight seal between the two package portions. This is accomplished through the sealing bar 56 which may, in one advantageous embodiment, cause heat sealing of the components together. The sealing bar 56 reciprocates with the pusher bar 54. However, the pusher bar 54 pushes the tubes 30 below the flanges to insure that, regardless of the package thickness, the tubes 30 do not interfere with the sealing process.
The completed package 38 may be removed by raising the cover 90 with the sealing bar 56 and pusher bar 54. The package 38 may be removed from the conforming carder 40. This may be accomplished in batch or continuous fashion as desired.
The cycle may be repeated after the gas tubes 30 are reciprocated to their upper position. This is achieved by supplying air pressure to the upper cylinders 30a. The air pressure is released through a relief valve (not shown) when the tubes 30 are pushed downwardly by the pusher bar 54.
The positioning of the upper and lower packaging portions 10 and 18 with respect to one another is assured by the provision of the guides 24 and the filling tubes 30 which interact with the special package shape to ensure exact juxtaposed position of the parts relative to one another. Moreover, the flange portions 36 of the upper package portion 18 maintain the separation of the package when they abut with the filling tubes 30.
Firstly, the lower package portion 10 is inserted into the conforming carrier 40, guided by tubes 30 and guides 24. Then, the upper package portion 18 is located on the tubes 30, positioned by the guides 24. Thereafter, the cover 90 is closed and the process may be repeated.
In many applications, particularly those involving red meat, it may be desirable to withdraw the low oxygen atmosphere from the container at the point of sale. Otherwise, the package with its low oxygen environment will cause the meat to have a purplish color. Thus, in the supermarket, the upper fluid impermeable film 66 may be peeled back. This allows ambient atmosphere to enter the package so that the meat will take on a reddish color.
The provision of the overhang 36 of the upper package portion 18 over the lower package portion 10 facilitates the removal of the domed upper package portion 18 in use. Moreover, the concealed location of the overhang 36 diminishes the possibility of accidental opening.
Thus, it is apparent that there has been provided, in accordance with the invention, a package, a method, and a packaging apparatus that satisfies the aims, objects, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such embodiments, alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. | A package, packaging method, and packaging apparatus for facilitating the packaging of large meat products and exchanging the ambient atmosphere to establish a desired gaseous atmosphere that extends the shelf life of the product. The package includes a pair of preformed relatively rigid plastic domed or cupped members which abut along a sealing surface. The upper and lower package portions include flanges which are adapted to facilitate not only the formation of the package but its subsequent opening. A reciprocatable filling tube maintains the separation between the upper and lower package portions to permit gas exchange and then may be reciprocated downwardly to allow the upper package portion to abut atop the lower package portion for sealing connection. | 1 |
TECHNICAL FIELD
[0001] This invention relates to a method and a device for locating a fault location within a section of a three-phase power transmission system having three terminals and by using only limited measurements.
BACKGROUND OF THE INVENTION
[0002] Power transmission lines carry electric power from generating sources to users. The power transmission lines are typically high voltage lines and the electric voltage is typically transformed down to a lower voltage at a power substation, before being distributed to individual electric power users such as homes, business buildings etc. At many power substations, protective relays are included.
[0003] The detection of a fault involves measuring critical system parameters and, when a fault occurs, quickly making a rough estimate of the fault location and of certain characteristics of the fault so that the faulted line can be isolated from the power grid as quick as possible. A fault occurs when a transmission line, typically due to external causes, diverts electrical current flow from its normal path along the transmission line.
[0004] The major types and causes of faults are insulation faults, caused by design defects, manufacturing defects, improper installation, and aging insulation; electrical faults, caused by lightning surges, switching surges, and dynamic overvoltages; mechanical faults, caused by wind, snow, ice, contamination, trees, and animals; and thermal faults, caused by overcurrent and overvoltage conditions.
[0005] A transmission line typically includes three phase lines, however, a transmission line may also contain one phase, or some other number of phases.
PRIOR ART
[0006] The issue of locating faults in three-terminal lines has been considered in the prior art. It is then considered that the vicinity of the three-terminal line is equivalent with three active systems located behind the respective line terminals. In such cases the active systems are in the form of the sources with EMFs (Electro Motive Force) and internal impedances. The arrangement of a three-terminal line with all active sources is treated as the standard in considering the problem of locating faults. If the tap node of the two-terminal line, dividing the line into the sending and receiving side, is used only for supplying, via power transformer, the passive load then such arrangement is also considered as a three-branches network, but with two active branches and one passive branch, see U.S. Pat. No. 6,466,030.
[0007] In Girgis (A. A., Hart D. G., Peterson W. L., “A new fault location technique for two-and three-terminal lines”, IEEE Trans. Power Delivery, Vol. 7, No. 1, pp. 98-107, January 1992) the use of complete measurements of three-phase currents and voltages from all three terminals of the line has been considered for fault location. Both the synchronized and unsynchronized measurements have been considered there.
[0008] Similarly, the availability of complete three-terminal measurements has been considered by Aggarwal (Aggarwal R. K., Coury D. V., Johns A. T., Kalam A., “Computer-aided design and testing of accurate fault location for EHV teed feeders”, in Proc. 1993 International Conference on DPSP, York, pp. 60-64.)
[0009] In the U.S. Pat. No. 6,256,592 the fault location system for application to three-terminal line has been disclosed. It also considers complete measurements at all terminals. However, in order to limit the amount of information, which has to be sent by the communication channels, the following minimal information sent by each relay, the measurements are considered as performed by digital relays installed at all three terminals, to each of the other relays is:
magnitude and angle of the phasor of the negative sequence current, magnitude and angle of the phasor of the calculated negative sequence voltage at the tap node.
[0012] Y. Lin et al (Y. Lin, C. Liu, C. Yu, “A new fault locator for three-terminal transmission lines using two-terminal synchronized voltage and current phasors”, IEEE Trans. Power Delivery, Vol. 7, No. 3, pp. 452-459, 2002.) has disclosed a fault locator for three-terminal transmission lines using incomplete, i.e. two-terminal synchronized voltages and current phasors.
[0013] Yet another limited application of measurements on a three-terminal line has been considered by Minambres (Minambres J. F., Zamora I., Mazon A. J., Zorrozua M. A., Alvarez-Isasi R., “A new technique, based on voltages, for fault location on three-terminal transmission lines”, Electric Power Systems Research 37 (1996), pp 143-151) and by Sukumar (Sukumar M. Brahma, “Fault Location Scheme for a Multi-Terminal Transmission Line Using Synchronized Voltage Measurements”, IEEE Trans. on Power Delivery, Vol. 20, No. 2, April 2005, pp. 1325-1331.) where the fault location is designed with use only voltages measured at all the terminals.
[0014] In U.S. Pat. No. 6,466,030 is disclosed a method for locating faults on a two-terminal line with a single tapped load (the arrangement also constituting of three branches) and the two-terminal unsynchronized voltage and current measurements is applied. The synchronization angle used for providing a common time base for the measurements is calculated with use of the available measurements.
[0015] The fault locator disclosed in U.S. Pat. No. 4,559,491 is designated for locating faults only on two-terminal lines. It can be easily extended for application to three-terminal line, however only if the tap of the line is of the form of the branch of the passive nature. In contrast, the presented invention of the fault locator suits for a more general case, i.e. for three-terminal lines having active systems at all the terminals.
SUMMARY OF THE INVENTION
[0016] The object of the present invention is to solve the problems related to known methods and prior art, and to create an improved, simple and reliable method and device for locating faults in a three-terminal power line.
[0017] In contrast to the approaches presented in the prior art this new method uses very limited number of measurements. It is considered that the fault location on three-terminal line is performed basically with use of three phase currents and voltages acquired at the bus where the fault locator is installed. Additionally, pre-fault flow of currents (pre-fault phasors of currents) in the remote remaining line sections is used. However, determination of this pre-fault flow does not require use of the measurement equipment for phasor measurement. The pre-fault phasors of currents can be determined analytically using the load currents flow programs or, as is proposed, can be calculated with using magnitudes of load currents in the remote sections. Information on magnitudes of load currents is usually available and thus can be included as the fault locator input data.
[0018] The important features of the invention is that limited measurements are used compared to earlier known methods. One-ended measurements of currents and voltages and additional information on amplitudes of load (pre-fault) currents from the remaining sections of the line are utilized only. Detailed impedance data of the network has to be provided as the fault locator input data. The method is based on the symmetrical components approach and thus is intended for application to the transposed lines. In case of the untransposed lines the presented algorithm has to be rewritten down using the phase co-ordinates description.
[0019] The algorithm considers that at each terminal there is an active system (with generation), however it operates correctly for the case with the passive load at the particular terminal (or terminals). It can be also extended for application to the lines with more terminals. The presented technique can be applied for fault location in distribution feeders in the presence of distribution generation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For better understanding of the present invention, reference will be made to the below drawings/figures.
[0021] FIG. 1 illustrates a schematic diagram of fault location on three-terminal line with limited measurements
[0022] FIG. 2 illustrates a circuit diagram of the network for faults in a section AT, for the incremental positive sequence.
[0023] FIG. 3 illustrates an equivalent circuit diagram of the network for faults in the section AT, for the negative sequence.
[0024] FIG. 4 illustrates an equivalent circuit diagram of the network for faults in the section BT, for the incremental positive sequence.
[0025] FIG. 5 illustrates an Equivalent circuit diagram of the network for faults in the section BT, for the negative sequence.
[0026] FIG. 6 illustrates an equivalent circuit diagram of the network for faults in the section BT, for the zero sequence.
[0027] FIG. 7 equivalent circuit diagram of the network for faults in the section CT, for the incremental positive sequence.
[0028] FIG. 8 illustrates an equivalent circuit diagram of the network for faults in the section CT, for the negative sequence.
[0029] FIG. 9 illustrates an equivalent circuit diagram of the network for faults in the section CT, for the zero sequence.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] It is well known that in order to assure high accuracy for locating faults, the use of communication means for sending the measurement data acquired at different network terminals is applied in modern microprocessor-based fault locators. However, the multi-terminal measurements are not always the case. Even if the multi-terminal measurements are at our disposal, it is advisable that the designed fault locator is equipped with the procedure utilizing basically the one-ended measurements. This since the loss of communication with the remote terminals may occur in reality. Of these reasons the fault location algorithm for a three-terminal line (see FIG. 1 ) with use of the limited measurements. Use of one-ended measurements of three phase voltages and currents, from the local terminal A, where the fault locator is installed, and additional information on pre-fault flow of currents in the remote sections, is proposed. It has been found that providing amplitudes of pre-fault currents from the other remote terminals (B and C) make possible determination of the pre-fault flow of currents. Impedance data for the whole network has also to be provided as the input parameters of the presented fault location algorithm. Information on fault such as:—fault type,—fault incipience and clearing time is also utilised.
[0031] The fault location algorithm comprises three subroutines: SUB_A, SUB_B, SUB_C (see FIG. 1 ), which are designated for locating faults in particular sections: AT, BT, CT of the line. Depending on the fault type, the respective fault-loops are considered by the all three subroutines.
[0032] In order to achieve good accuracy of the fault location the compensation for the reactance effect is incorporated in the subroutines. It is distinctive, that in case of locating faults in the sections LB, LC, which are not adjacent to the main measurement terminal A, the analytical shift of the measurements to the tap point T is applied. After considering these three hypotheses—according to the subroutines: SUB_A, SUB_B, SUB_C, the valid subroutine is selected.
[0033] Fault Location—Subroutine: SUB_A
[0034] FIG. 1 illustrates a schematic diagram of fault location on three-terminal line with limited measurements. Assuming the hypothesis that a fault happens within the section LA the following generalized fault loop model is formulated:
V _ Ap - d FA Z _ 1 LA I _ Ap - R FA ( a _ F 1 Δ I _ A 1 k _ FA 1 + a _ F 2 I _ A 2 k _ FA 2 + a _ F 0 I _ A 0 k _ FA 0 ) = 0 ( 1 )
where:
d FA —distance to fault (p.u.), counted at the bus A up to a fault point FA in the line section AT, R FA —fault resistance, V AP , I Ap —fault loop voltage and current composed according to the fault type—Table I, Z ILA =R ILA +jX ILA —impedance of the line section AT for the positive sequence, Δ I A1 = I A1 − I A1 pre —incremental (superimposed) positive sequence component of currents from the terminal A, I A2 , I A0 —negative and zero sequence currents from A, k FA1 , k FA2 , k FA0 —fault current distribution factors for the positive, negative, zero sequences, respectively, a F1 , a F2 , a F0 —share coefficients (Table II).
[0043] The fault loop signals are further uniformly expressed in terms of the sequence quantities (the last subscript denotes the respective sequence):
V _ Ap = a _ 1 V _ A 1 + a _ 2 V _ A 2 + a _ 0 V _ A 0 ( 2 ) I _ Ap = a _ 1 I _ A 1 + a _ 2 I _ A 2 + a _ 0 Z _ 0 LA Z _ 1 LA I _ A 0 ( 3 )
where:
a 1 , a 2 , a 0 —weighting coefficients (Table I).
[0045] In general, there is certain freedom in setting the share coefficients. It has been proposed to utilize that for limiting adverse influence of uncertainty with respect to zero sequence impedance data upon the fault location accuracy. Therefore, for further application the set with the share coefficient for the zero sequence equal to zero (Table II) is taken. In consequence, there is a need for considering the flow of currents for the incremental positive and for the negative sequences only (see FIGS. 2 and 3 ). Note that in FIG. 3 and further on, the negative sequence and the positive sequence impedances are marked identically ( Z 2LA = Z 1LA ).
[0046] The performed analysis for the circuit of FIG. 2 , illustrating an Equivalent circuit diagram of the network for faults in the section AT, for the incremental positive sequence, has yielded the following form of the fault distribution factors for the positive (negative) sequences:
k _ FA 1 = k _ FA 2 = K _ A 1 d FA + L _ A 1 M _ A 1
where :
K _ A 1 = Z _ 1 LA
L _ A 1 = ( Z _ 1 LB + Z _ 1 SB ) ( Z _ 1 LC + Z _ 1 SC ) Z _ 1 LB + Z _ 1 SB + Z _ 1 LC + Z _ 1 SC
M _ A 1 = L _ A 1 + Z _ 1 SA ( 4 )
TABLE I Weighting Coefficients in Fault Loop Signals (2)-(3) Fault type a 1 a 2 a 0 a-g 1 1 1 b-g a 2 a 1 c-g a a 2 1 a-b 1 − a 2 1 − a 0 a-b-g a-b-c a-b-c- g b-c a 2 − a a − a 2 0 b-c-g c-a a − 1 a 2 − 1 0 c-a-g a _ = exp ( j 2 π / 3 ) j = - 1
[0047]
TABLE II
Chosen set of share coefficients in (1), (6)
Fault type
a F1
a F2
a F0
a-g
0
3
0
b-g
0
3a
0
c-g
0
3a 2
0
a-b
0
1 − a
0
b-c
0
a − a 2
0
c-a
0
a 2 − 1
0
a-b-g
1 − a 2
1 − a
0
a-b-c-g,
a-b-c
b-c-g
a 2 − a
a − a 2
0
c-a-g
a − 1
a 2 − 1
0
[0048] Taking into account the share coefficients from Table II and substituting (4) into (1) results after rearranging in the following quadratic equation for complex numbers:
A _ 2 d FA 2 + A _ 1 d FA + A _ 0 + A _ 00 R FA = 0
where :
A _ 2 = Z _ 1 LA K _ A 1
A _ 1 = Z _ 1 LA L _ A 1 - Z _ Ap K _ A 1
A _ 0 = Z _ Ap L _ A 1
A _ 00 = M _ A 1 ( a _ F 1 Δ I _ A 1 + a _ F 2 I _ A 2 ) I _ Ap
Z _ Ap = V _ Ap I _ Ap - apparent impedance of the fault loop . ( 5 )
[0049] The complex formula (5) can be resolved into the real and imaginary components giving the respective two equations for real numbers. In consequence, it is possible to get the solution for both unknowns: d FA —distance to fault (counted from the bus A), R FA —fault resistance.
[0050] Subroutine: SUB_B
[0051] Again, the shunt capacitances of the lines are neglected at this stage. However, in order to improve fault location accuracy they can be accounted for further. In case of the subroutine SUB_B, designated for faults in the section BT, the following generalized fault loop model is formulated:
V _ Tp - ( 1 - d FB ) Z _ 1 LB I _ TBp - R FB ( a _ F 1 Δ I _ TB 1 k _ FB 1 + a _ F 2 Δ I _ TB 2 k _ FB 2 ) = 0 ( 6 )
where:
[0052] Fault loop voltage transferred to the tap point T:
V TP = a 1 V T1 + a 2 V T2 + a 0 V T0 (7)
[0053] Fault loop current transferred to the tap point T (from the side of the section BT— FIG. 1 ):
I _ TBp = a _ 1 ( Δ I _ TB 1 + I _ TB 1 pre ) + a _ 2 I _ TB 2 + a _ 0 Z _ 0 LB Z _ 1 LB I _ TB 0 ( 8 )
a 1 , a 2 , a 0 —weighting coefficients (Table I)), k FB1 , k FB2 —fault current distribution factors for the positive, negative sequences, respectively, a F1 , a F2 , a F0 —share coefficients (Table II).
[0057] Transfer of the fault loop voltage from the bus A to the tap point T can be accomplished as follows:
[ V _ T 1 V _ T 2 V _ T 0 ] = [ V _ A 1 V _ A 2 V _ A 0 ] - [ Z _ 1 LA I _ A 1 Z _ 1 LA I _ A 2 Z _ 0 LA I _ A 0 ] ( 9 )
[0058] In the weighted sum (8) there are symmetrical components of the transferred current. In case of the positive sequence the component is taken as the sum of the incremental positive sequence current Δ I TB1 and its pre-fault value I TB1 pre .
[0059] The currents: Δ I TB1 , I TB2 , I TB0 (incremental positive, negative and zero sequence currents at the transfer point (at the end of the section BT, connected to the tap point T— FIG. 4 )) is determined by considering the respective equivalent circuit diagrams. Knowledge of the measured currents: Δ I A1 , I A2 , I A0 ; voltages: Δ V A1 , V A2 , V A0 and impedance data of the network are required for that.
[0060] For example, FIG. 4 may result in:
Δ I _ TB 1 = Δ I _ A 1 - V _ A 1 - Z _ 1 LA Δ I _ A 1 ( Z _ 1 LC + Z _ 1 SC ) ( 10 )
[0061] Analogously, one obtains for the other symmetrical components:
I _ TB 2 = I _ A 2 - V _ A 2 - Z _ 1 LA I _ A 2 ( Z _ 1 LC + Z _ 1 SC ) ( 11 ) I _ TB 0 = I _ A 0 - V _ A 0 - Z _ 0 LA I _ A 0 ( Z _ 0 LC + Z _ 0 SC ) ( 12 )
[0062] In fact, in order to assure proper accuracy of fault location, the transferring of fault loop signals (8)-(9) has to be done with using the distributed parameter line model, see FIG. 4 showing an equivalent circuit diagram of the network for faults in the section BT, for the incremental positive sequence.
[0063] The pre-fault positive sequence current I TB1 pre at the transfer point (8) can be determined with use of the measured current I A1 pre and amplitudes of currents from the buses B, C: | I B1 pre |, | I C1 pre |, which are considered as the input data of the fault locator ( FIG. 1 ). From FIG. 1 results:
I A1 pre − I TB1 pre − I TC1 pre =0 (13)
[0064] Resolving (13) into the real and imaginary parts yields:
real( I A1 pre )−real( I TB1 pre )−real( I TC1 pre )=0 (14)
imag( I A1 pre )−imag( I TB1 pre )−imag( I TC1 pre )=0 (15)
[0065] The extra two relations involving the pre-fault amplitudes of currents from the buses B and C can be written down as:
[real( I B1 pre )] 2 +[imag( I B1 pre )] 2 =| I B1 pre | 2 (16)
[real( I C1 pre )] 2 +[imag( I C1 pre )] 2 =| I C1 pre | 2 (17)
[0066] Since shunt capacitances of the line are here neglected, then the pre-fault currents at both ends of each section are identical and therefore in (16)-(17) the subscripts: B1, C1 can be changed to: TB1, TC1, i.e. as in (14)-(15)
[0067] Finally, one obtains the set of 4 equations: (14)-(17) in four unknowns: real( I TB1 pre ), imag( I TB1 pre ), real( I TC1 pre ), imag( I TC1 pre ), which after solving gives the required pre-fault phasors of currents from the remote terminals B and C.
[0068] The fault current distribution factor for the positive (negative) sequence can be obtained analysis of the flow of currents in the circuit diagram from FIG. 3 :
k _ FB 1 = k _ FB 2 = K _ B 1 d FB + L _ B 1 M _ B 1
where :
K _ B 1 = Z _ 1 LB
L _ B 1 = Z _ 1 SB
M _ B 1 = ( Z _ 1 LA + Z _ 1 SA ) ( Z _ 1 LC + Z _ 1 SC ) Z _ 1 LA + Z _ 1 SA + Z _ 1 LC + Z _ 1 SC + Z _ 1 LB + Z _ 1 SB ( 18 )
[0069] Substitution of the fault current distribution factors (18) into the general fault model (6) results in the quadratic formula for complex numbers, analogously as for the case of faults occurring in the section AT (5). Its solution is also straightforward.
[0070] Subroutine: SUB_C
[0071] Formulation of the remaining subroutine SUB_C can be performed analogously as it was presented for the subroutine SUB_B. For this purpose the equivalent circuit diagrams as in FIGS. 7, 8 , 9 are considered.
[0072] Selection Procedure
[0073] The final step in the fault location algorithm relies on selecting the valid subroutine, i.e. on indicating which the subroutine yields the results corresponding to the real distance to fault and fault resistance.
[0074] The subroutine, which yields distance to fault outside its line section, and/or negative fault resistance, is surely false and has to be rejected. If this is not so, the other criteria have to be considered. In the carried out study the following criteria quantities were utilized:
total fault currents in faulted phases (ought correspond to the measured currents), amplitudes of tbtal fault current in healthy phases (ought to be close to zero).
[0077] It is noted that while the above disclosure describes and exemplifying embodiments of the invention, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention as defined in the appended claims. | A method for locating a fault in three terminal power line, having sections located in front of or behind of the tap point and which assumes occurrence of the fault in at least one of those sections. Three phase currents and voltages are measured at one end of the power lines system. The amplitudes of load currents in the remaining sections of the power lines system are measured before a fault occurs. The measurements of the amplitudes of load currents are stored in the remaining sections of the power lines system. Impedance data of the network are determined. The symmetrical components approach is used when calculating the location of the fault. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/108,736, filed on Jan. 28, 2015. The foregoing provisional application is incorporated by reference herein in its entirety.
BACKGROUND
[0002] Rolls of labels are converted on high speed label presses. A master roll is loaded into the press and feed through a series of ink rollers, image rollers, dryers, die cutting rollers and slitter to a rewinder. The rewinder typically can be set to sense a number of labels on the web or footage of media it is winding, when the target number of labels is reached. The rewinder automatically cuts the web and starts the roll onto a new core. This creates a conventional roll of labels ( FIG. 3 ) with labels from the start to the end of the liner on a roll. A typical manufacturer who uses labels, will have to remove 1 to 4 feet of labels from the roll, so that the labels can be threaded through a bar code printer or label applicator. Leaving the labels on the roll and feeding them through a machine can cause the labels to stick to components within the machines, such as rollers, guides, creating a mess that requires extra time to correct. Thus, most manufacturers have to take the time remove the labels manually and dispose of the them, which can be a costly problem with conventionally rolled labels.
[0003] Some label suppliers will manually remove the labels, and charge an increased cost to the manufacturers for this service. The label supplier will use a crew of people to manually count and remove each label from the roll. For production runs of 100,000 or more labels, this becomes a substantial task.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Features, aspects, and advantages of the present invention will become apparent from the following description and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.
[0005] FIG. 1 is a perspective view of a roll of labels with the labels extending to the end of the roll.
[0006] FIG. 2 is a perspective view of a roll of inside wound labels with a number of labels removed automatically, according to an exemplary embodiment.
[0007] FIG. 3 is a perspective view of a roll of outside wound labels with a number of labels removed automatically, according to an exemplary embodiment.
[0008] FIG. 4 is a perspective view of a label removal apparatus in an inactive state, according to an exemplary embodiment.
[0009] FIG. 5 is a perspective view of the label removal apparatus of FIG. 4 , in an active state to remove labels from the label sheet.
[0010] FIG. 6 is a side view of the label removal apparatus of FIG. 4 in an inactive state.
[0011] FIG. 7 is a side view of the label removal apparatus of FIG. 4 in an active state.
[0012] FIG. 8 is a side view of the label removal apparatus of FIG. 4 in an inactive state and installed in a label converting press, according to an exemplary embodiment.
[0013] FIG. 9 is a side view of the label removal apparatus of FIG. 4 in an active state and installed in a label converting press, according to an exemplary embodiment.
[0014] FIG. 10 is a side view of a label removal apparatus in an inactive state, according to another exemplary embodiment.
[0015] FIG. 11 is a side view of the label removal apparatus of FIG. 10 in an active state.
[0016] FIG. 12 is a side view of the label removal apparatus of FIG. 10 in an inactive state and installed in a label converting press, according to an exemplary embodiment.
[0017] FIG. 13 is a side view of the label removal apparatus of FIG. 10 in an active state and installed in a label converting press, according to an exemplary embodiment.
DETAILED DESCRIPTION
[0018] It is to be understood that the following detailed description are exemplary and explanatory only, and are not restrictive of the invention.
[0019] It should be noted that the term “exemplary” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).
[0020] References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.
[0021] A label removal apparatus automatically removes labels from the backing web while the labels are being processed, such as in a conversion press. The web and remaining labels may be wound in another device to creates a roll of labels with labels automatically removed to form a leader.
[0022] Referring to FIG. 1 , labels 10 may be affixed to a web 12 (e.g., liner, backing sheet, etc.) and provided in a roll 14 . The labels 10 are formed from a flexible material (e.g., film, paper, laminate) and include an adhesive applied to the back side of the labels 10 . The web 12 may be coated with a material, such as silicone, that allows for the easy removal of the labels 10 from the web 12 . The web 12 with the labels 10 may be provided in the form of a roll 14 wrapped around a core 15 . The roll 14 be configured with the labels 10 affixed to the inside surface of the web 12 ( FIGS. 1 and 2 ) (i.e., inside wound) or on the outside surface of the web 12 ( FIG. 3 ) (i.e., outside wound). As shown in FIGS. 2 and 3 , a number of labels 10 may be removed from the free end 16 of the roll 14 such that a length of the web 12 lacks labels 10 to form a leader 18 . Such a roll 14 may be utilized, for example, in a mechanism where it is desirable to feed the leader 18 through the mechanism without the possibility of labels 10 becoming dislodged from the web 12 and disrupting the mechanism.
[0023] Referring to FIGS. 4-9 , a label removal apparatus 20 is shown according to an exemplary embodiment. The label remover apparatus 20 is configured to automatically remove a number of labels 10 from the web 12 while the labels 10 are being processed to form the roll 14 . In this way, the roll 14 may be produced with a number of labels 10 already removed from the end of the roll 14 to form a leader 18 , negating the need for an end user or a manufacturer to manually remove the labels 10 to form the leader 18 . The label removal apparatus 20 includes a frame 22 , a plate 24 that is moveable relative to the frame 22 , an actuator 26 configured to move the plate 24 between a first position and a second position, one or more rollers 28 , a removal device, a sensor device 32 , and a controller 40 configured to control the actuator 26 and the removal device.
[0024] The plate 24 is mounted below the web 12 passing through the label removal apparatus 10 . As shown in FIGS. 6-7 , the plate 24 is coupled to the frame 22 at the leading edge with a pinned connection 23 . The plate 24 is coupled to the actuator 26 at the trailing edge with a pivoting joint 25 . The frame 22 is a stationary body that is coupled to a structure that is generally fixed vertically relative to the ground (e.g., the floor, a base, another mechanism, etc.). The actuator 26 is shown as a pair of pneumatic cylinders mounted on either side of the plate 24 with one end coupled to the plate 24 and the opposite end coupled to the frame 22 . In other embodiments, the actuator 26 may include any number of linear or rotary actuators (e.g., hydraulic cylinders, motor driven devices, or any other devices). The actuator 26 moves the plate 24 between a first position (e.g., lowered position, horizontal position, home position, inactive position, etc.) and a second position (e.g., raised position, angled position, active position, etc.). The plate 24 may be limited by one or more mechanical stops 29 . The positions of the stops 29 may be adjustable. In the first position, the plate 24 is lowered in a horizontal orientation such that the web 12 can pass over the plate 24 unencumbered through the label removal apparatus 10 . In the second position, the actuator 24 moves the trailing edge of the plate 24 upward. The pinned connection 23 and the pivoting joint 25 allow the plate 24 to be angled relative to horizontal in the second position. In the second position, the plate 24 reroutes the web 12 and labels 10 to another angle. The web 12 engages one or more rollers 28 , which are coupled to the frame 22 , such that displacement of the web 12 by the plate 24 is localized and the web 12 enters and exits the label removal apparatus 10 at the same points whether the plate 24 is in the first position or the second position.
[0025] According to an exemplary embodiment, the removal device is a vacuum take away device 30 that uses a vacuum to pull the labels 10 off of the web 12 . The vacuum take away device 30 is configured to selectively remove or peel off the labels 10 from the web 12 . The angle of the web 12 proximate the vacuum take away device 30 (i.e., the peel angle) may be adjusted to facilitate the removal of the labels 10 from the web 12 . For example, the vacuum take away device 30 may be able to more easily remove the labels 10 as the angle increases. The peel angle may be adjusted via the mechanical stops 29 , to limit the angle.
[0026] The vacuum take away device 30 may be connected to an existing vacuum system in use with the mechanisms processing the labels 10 before or after the label removal apparatus 20 . The labels 10 removed from the web 12 by the vacuum take away device 30 may be routed to a vacuum duct and automatically discarded in a receptacle for disposal.
[0027] The actuator 26 is controlled by a controller 40 that monitors the passage of the labels 10 and web 12 through the label removal apparatus 20 and determines how many labels 10 to remove from the web 12 . In an exemplary embodiment, the control system 40 includes a processor 42 , a memory device 44 , a user input device 46 , and an output device 48 . According to an exemplary embodiment, components of the control system 40 may be housed in an industrial cabinet to protect the components from the elements.
[0028] The processor 42 can be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components. In another exemplary embodiment, the control system 40 may include a controller lacking a processor or memory. For example, the control system may be a linear circuit.
[0029] The memory device 44 (e.g., memory, memory unit, storage device, etc.) is one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present application. The memory device 44 may be or include volatile memory or nonvolatile memory. The memory device 44 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present application. According to an exemplary embodiment, the memory device 44 is communicably connected to the processor via the processing circuit and includes computer code for executing (e.g., by processing circuit and/or processor) one or more processes described herein.
[0030] The input device 46 is one or more devices that allow a user to input commands and control variables for the label removal apparatus 20 (e.g., timing changes as required for different size labels 10 , different desired leader lengths, etc.). The input device 46 may be, for example, a touch screen monitor, a keyboard or keypad, push buttons, dials, switches, or any combination of devices. The output device 48 is one or more devices that allow a user to monitor the properties of the label removal apparatus 20 and may be integrated with the input device 46 . The output device 48 may be, for example, a monitor, a touch screen monitor, a text display, a numeric display, or a combination of devices.
[0031] The controller 40 monitors the passage of the labels 10 through the label removal apparatus 20 with the sensor device 32 . The sensor device 32 detects the difference between the labels 10 and the web 12 (e.g., the gaps between the labels 10 ) to determine the rate with which the labels 10 and web 12 are passing through the label removal apparatus and the number of labels 10 . The sensor device 32 transmits a signal to the controller 50 . According to an exemplary embodiment, the sensor device 32 is a photoelectric eye. In other exemplary embodiments, the sensor device 32 may be any suitable device capable of detecting the labels 10 and/or the gaps between the labels 10 and transmitting a signal to the controller 50 , such as a mechanical switch or a laser sensor.
[0032] As the labels 10 path beneath sensor device 32 , the sensor device 32 transmits a signal or trigger to the controller 50 . The controller 50 counts the number of triggers it receives. Once a predetermined count has been reached, the controller 50 activates the actuator 26 to raise the plate 24 from the first position to the second position. In the second position, the plate 24 locally deflects the web 12 at an angle (i.e., the peel angle) to bring it closer to the vacuum take away device 30 , which peels or otherwise removes the labels 10 from the web 12 .
[0033] The sensor device 32 continues to send signals to the controller 50 with the plate 24 in the second position. After the predetermined number of labels 10 have been removed from the web 12 by the vacuum take away device 30 , the controller 50 activates the actuator 26 to lower the plate 24 to the first position. The cycle repeats until the operator stops the apparatus.
[0034] Referring now to FIGS. 8-9 , the label removal apparatus 20 is shown mounted in line with a label converting press 60 configured to print and cut a plurality of labels 10 on the web 12 and a turret rewinder 70 configured to wind the labels 10 and web 12 into the roll 14 .
[0035] The label converting press 60 , for example, may include a roll 62 of label media comprising a strip of label material and web. The label media is routed through multiple idle rollers 65 . A print roller 64 prints the text and/or graphic designs on the labels 12 and a die cutter 66 cuts the label material into individual labels 10 while leaving the web 12 uncut. The label material removed to form the gaps between the labels 10 may be removed with a vacuum take away system 68 .
[0036] The web 12 exit the label converting press 60 . Instead of being routed directly to the turret rewinder 70 , the web 12 is run through the label removal apparatus 20 where a desired number of labels 10 are removed from the web 12 . After exiting the label removal apparatus 20 , the web 12 is run through the turret rewinder 70 .
[0037] The turret rewinder 70 , for example, may include a web cutter 72 configured to cut the web 12 into discreet lengths with the portion of the web 12 lacking the predetermined number of labels 10 and forming the leader 18 on one end. The web 12 is wound onto a core mounted to a turret 74 . Once the roll 14 is completely wound, the turret 74 is advanced so that a new roll 14 can be started and the finished roll 14 removed. The controller 50 controls the web cutter 72 and the turret 74 to produce a finished roll 14 with a desired number of labels 10 and a leader 18 of a desired length.
[0038] Referring now to FIGS. 10-13 , a label removal apparatus 20 is shown according to another exemplary embodiment in which the removal device is a drum accumulator 80 . Such a drum accumulator 80 includes a cylindrical drum 82 with an array of vacuum holes 84 disposed, about the circumference of the drum 82 . A vacuum is drawn on the drum 82 and the labels 10 are held against the drum 82 at the vacuum holes 82 . The drum 82 rotates to bring the labels 10 away from the web 12 until they reach an accumulation roller 86 . According to an exemplary embodiment, the accumulator roller includes a discardable core 88 that is formed from a material to which the labels 10 will adhere (e.g., cardboard, etc.). The labels 10 are held on the drum 82 with the adhesive side facing outward. As the labels 10 reach the accumulation roller 86 , the labels sticks to the core 88 , overcoming the force of the vacuum and removing the labels 10 from the drum 82 . The core 88 may periodically be removed as a number of labels 10 are collected and replaced with a fresh core 88 .
[0039] A vacuum blocker plate 85 may be disposed on the interior of the vacuum drum 82 opposite of the side of the drum on which the labels 10 travel from the web 12 to the accumulation roller 86 . The vacuum blocker plate 85 is curved to match the interior surface of the drum 82 and includes sealing elements (e.g., gaskets, etc.) to form a seal against the interior surface of the drum 82 . The vacuum blocker plate 85 minimizes vacuum losses on the side of the drum 82 on which the vacuum holes 82 are not covered by the labels 10 .
[0040] The drum accumulator 80 may be utilized for a label removal apparatus 20 installed in line with an apparatus lacking an existing vacuum disposal system. A vacuum need only by applied to the drum accumulator 80 with the labels 10 disposed manually through the removal of the core 88 .
[0041] The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.
[0042] It is important to note that the label removal apparatus as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention. | A method of manufacturing a roll of adhesive labels. The method includes the step of providing a plurality of adhesive labels fixed to a backing sheet. A predetermined number of labels are removed from the backing sheet to thereby form a leading edge of the sheet that only includes the backing sheet and no labels. The leading edge includes no labels to thereby facilitate mounting the sheet of carrier material on a printing or applicator machine. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 61/882,448 entitled “Projector Device for Rail Applications” filed on Sep. 25, 2013, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The present disclosure generally relates to systems and methods for use in track corrections, such as lifting, aligning, cross-leveling and/or applying geometric corrections (generally referred to as “surfacing and lining” operations) to railroad tracks.
BACKGROUND
Railroads are typically constructed to include a pair of elongated, substantially parallel rails, which are coupled to a plurality of laterally extending ties. The ties are disposed on a ballast bed of hard particulate material such as gravel. Over time, normal wear and tear on the railroad may cause the rails to deviate from a desired geometric orientation.
Rail maintenance processes for addressing such concerns typically involve the use of a tamping machine with a buggy, which cooperate with each other to provide a three-point reference system to measure the position of the track prior to applying the desired corrections to the track. A typical correction process involves lifting rail with mechanical clamps, aligning the track by shifting it to a calculated position, and then tamping the ballast under each tie to hold the track in place. This work sequence is typically repeated at each tie during the course of the correction process.
Known reference systems often utilize light beams or lasers either alone or in combination with tensioned wires. In such systems, a buggy vehicle is equipped with a light source or laser projector, a shadow board extends from the rail maintenance vehicle, and a pair of receivers, each positioned over corresponding rail, are positioned at the rear of the tamping machine.
The reference points are used to establish a geometry of the track at the particular location being worked. That is, the recorded values are used to triangulate the geometry of the section of track being worked, while an onboard computer compares the previous section of track already corrected to the current section and makes the calculations for the required corrections to be made at the work heads. Similar recording and corrections are made with four point reference systems, i.e., the recorded geometry is calculated and corrected using different formulas that result in correction of the track to a desired position.
However, known reference systems are subject to a variety of outside influences and factors that may prevent the track from being returned to the desired geometric orientation, thereby reducing the efficiency of a railroad vehicle traveling along the track. For example, the receiver pairs may be tuned to search for a specific frequency of light that may be negatively affected by ambient light (i.e., sunlight) when the buggy vehicle is spaced apart from the rail maintenance vehicle. In addition, the tensioned wires may be affected by wind and weather, may become tangled or caught, and may be difficult to keep taut. Accordingly, an improved system for use in carrying out surfacing and/or lining operations on railroad tracks is desired.
BRIEF SUMMARY
The present disclosure is directed to improved systems and methods for use in rail track corrections such as surfacing and/or lining operations on railroad track. The systems and methods may comprise a projector device positioned on a first rail vehicle and a pair of receiver devices positioned on a second rail vehicle. The projector may include a Fresnel lens and a plurality of light emitting diodes (LEDs) arranged to emit a light beam. In some embodiments, the LEDs are infrared LEDs and the Fresnel lens is replaced with a convex lens or other optical lens that cooperates with the LEDs to collimate the light source In some embodiments, the projector device may be positioned on a buggy vehicle deployed ahead of a rail maintenance vehicle, such as a tamping machine. The rail maintenance vehicle may be equipped with receiver pairs disposed on each side of the machine as well as a receiver pair disposed on top of the machine.
In practice, the projector device is activated to provide a beam that provides a uniform “spot” (i.e., a uniform beam). The light beam is then modulated in such a manner that the receivers can detect the light source. For example, the light emitted from the projector device may be modulated in a range of between about 50 Hz and 2200 Hz. In this manner, the light intensity and frequency of wavelength of light received into each receiver of a receiver pair is substantially equal. Recorded values may be used to triangulate the geometry of the section of track being worked, while a computer (e.g., disposed on the rail maintenance vehicle) compares the previous section of track already corrected to the current section and makes calculations for desired corrections to be made at work heads on the rail maintenance vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments are illustrated by way of example in the accompanying figures, in which like reference numbers indicate similar parts, and in which:
FIG. 1 illustrates a perspective view of a first rail vehicle having a projector device and a second rail vehicle having a receiver device for rail correction applications, in accordance with one embodiment of the present disclosure;
FIG. 2 illustrates a top view of the first rail vehicle and the second rail vehicle depicted in FIG. 1 , in accordance with one embodiment of the present disclosure;
FIG. 3 illustrates a side view of the first rail vehicle and the second rail vehicle depicted in FIG. 1 , in accordance with one embodiment of the present disclosure;
FIG. 4 illustrates a front view of the projector device of FIG. 1 , in accordance with one embodiment of the present disclosure;
FIG. 5 illustrates a perspective view of the projector device depicted in FIG. 4 , in accordance with one embodiment of the present disclosure;
FIG. 6 illustrates a side view of a lens casing of the projector device of FIG. 1 , in accordance with one embodiment of the present disclosure;
FIG. 7 illustrates a perspective view of the lens casing depicted in FIG. 6 , in accordance with one embodiment of the present disclosure;
FIG. 8 illustrates a perspective view of the receiver device depicted in FIG. 1 , in accordance with one embodiment of the present disclosure;
FIG. 9 illustrates a perspective view of the first rail vehicle and a plurality of projectors, in accordance with one embodiment of the present disclosure;
FIG. 10 illustrates a perspective view of the first rail vehicle having the projector device and the second rail vehicle having the receiver device in operation, in accordance with one embodiment of the present disclosure;
FIG. 11 illustrates a top view of the first rail vehicle having the projector device and the second rail vehicle having the receiver device in operation, in accordance with one embodiment of the present disclosure;
FIG. 12 illustrates a side view of the first rail vehicle having the projector device and the second rail vehicle having the receiver device in operation, in accordance with one embodiment of the present disclosure; and
FIG. 13 illustrates a data processing system for carrying out methods according to one embodiment of the present disclosure.
DETAILED DESCRIPTION
While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the disclosure and do not limit the scope of the disclosure.
To facilitate the understanding of this disclosure, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present disclosure. Terms such as “a”, “an”, and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the disclosure, but their usage does not limit the disclosure, except as outlined in the claims.
Various embodiments of systems and methods of rail track corrections according to the present disclosure are described. It is to be understood, however, that the following explanation is merely exemplary in describing the devices and methods of the present disclosure. Accordingly, several modifications, changes and substitutions are contemplated.
FIG. 1 illustrates a perspective view, FIG. 2 illustrates a top view, and FIG. 3 illustrates a side view of a first rail vehicle 100 having one or more projector devices 102 and a second rail vehicle 104 having one or more receiver devices 106 for use in rail correction applications, in accordance with one embodiment of the present disclosure. In an embodiment, the first rail vehicle 100 may comprise a buggy and the second rail vehicle 104 may comprise a tamping vehicle. The first rail vehicle 100 may be tethered to the second rail vehicle 104 or the first rail vehicle 100 may be a drone vehicle separate from the second rail vehicle 104 .
The second rail vehicle 104 may further comprise one or more shadow boards 108 operable to work in conjunction with the one or more projector devices 102 and the one or more receiver devices 106 . The projector devices 102 , the receiver devices 106 , and the shadow boards 108 may be configured for rail leveling, rail lining, or a combination of the two. In the leveling configuration, a projector device 102 may be positioned on top of the first rail vehicle 100 and a corresponding shadow board 108 and pair of receiver devices 106 may be positioned on top of the second rail vehicle 104 . In the lining configuration, a projector device 102 may be positioned on either (or both) side(s) of the first rail vehicle 100 , proximate to the rail, and a corresponding shadow board 108 and receiver device 106 may be positioned on the corresponding side of the second rail vehicle 104 , also proximate to the rail. During operation, in both rail lining and rail leveling configurations, the first rail vehicle 100 and the one or more projector devices 102 are spaced at a distance from the second rail vehicle 104 and the one or more receiver devices 106 , and the one or more shadow boards 108 are positioned between the one or more projector devices 102 and the one or more receiver devices 106 . The shadow boards 108 may be located proximate to the receiver devices 106 and are operable to block a light beam emitted from one or more projector devices 102 and prevent the one or more receiver devices 106 from receiving the light beam.
FIG. 4 illustrates a front view and FIG. 5 illustrates a perspective view of the projector device 102 of FIG. 1 , in accordance with one embodiment of the present disclosure. The projector device 102 may include a casing 112 and a plurality of infrared light-emitting diodes or “LEDs” 110 arranged in a circular configuration about an inner edge of the casing 112 . Of course, other embodiments are contemplated in which the LEDs 110 are arranged in other configurations, such as rectangular or square configurations. Also, other types of LEDs may be employed other than infrared LEDs. The LEDs 110 are positioned within the casing 112 having a detachable face 114 . The detachable face 114 may be secured to the casing 112 via connectors 116 , such as threaded screws. The detachable face 114 further comprises a lens 115 disposed over the LEDs 110 for generating the desired light beam. In some embodiments, the lens 115 may be a Fresnel lens, a convex lens, or lens of another shape that collimates the light source. The LEDs 110 and the lens 115 may be housed in a removable lens casing 117 .
FIG. 6 illustrates a side view and FIG. 7 illustrates a perspective view of the lens casing 117 of the projector device of FIG. 1 , in accordance with one embodiment of the present disclosure. The lens casing 117 houses the lens 115 and the LEDs 110 . The lens 115 used according to the present disclosure may be thin (e.g., between about 0.2 and 0.3 inches) and may be adapted to produce a substantially uniform light source. The combination of the circular array of LEDs and the lens creates a homogenous light “spot,” regardless of the number of individual LEDs used in the array.
FIG. 8 illustrates a perspective view of the receiver device 106 depicted in FIG. 1 , in accordance with one embodiment of the present disclosure. The receiver device may comprise a housing 118 and one or more optical lenses 120 positioned about the housing 118 and one or more optical filters positioned proximate to and behind the optical lenses 120 . The optical lenses 120 may be optimized for a desired range of light intensity and frequency of wavelength of light, e.g., near infrared or infrared light. In an embodiment, each receiver device 106 may comprise two optical lenses 120 operable to receive lights from the projectors and convert the light into an electrical system that may be directed to a computerized control system. In an embodiment, the receiver device 106 may be positioned on the second rail vehicle in either a substantially vertical orientation on top of the second rail vehicle for leveling operations or in a substantially horizontal orientation on the sides of the second rail vehicle for lining operations.
FIG. 9 illustrates a perspective view of the first rail vehicle 100 and a plurality of projectors 102 , in accordance with one embodiment of the present disclosure. In an embodiment, the first rail vehicle 100 may comprise a frame structure 122 that extends from proximate to the rails upward to a height substantially equal to a height of the second rail vehicle. In an embodiment, a projector device 102 may be positioned on top of the first rail vehicle 100 for leveling operations.
The frame structure 122 may comprise a plurality of wheels 124 that allow the first rail vehicle 100 to move along the rail. The frame structure 122 may further comprise a lining projector carrier 126 operable to extend below the frame structure 122 and travel along the rail independently of the plurality of wheels 124 . The lining projector carrier 126 may be operable to receive one or more projector devices 102 , and the one or more projector devices 102 may be extended outwardly from the frame structure 122 . In an embodiment, one or more projector devices 102 may be positioned on the sides of the first rail vehicle 100 for lining operations.
FIG. 10 illustrates a perspective view, FIG. 11 illustrates a top view, and FIG. 12 illustrates a side view of the first rail vehicle 100 distant from the second rail vehicle 104 , in accordance with one embodiment of the present disclosure. As shown in FIG. 10 , the first rail vehicle 100 and the second rail vehicle 104 may be configured for both lining and leveling operations.
In operation, the one or more projector devices 102 may be positioned on the first rail vehicle 100 , i.e., the buggy vehicle, deployed ahead of the second rail vehicle 104 , i.e., a rail maintenance vehicle, such as a tamper vehicle. The buggy vehicle may be tethered to the rail maintenance vehicle, or in some embodiments, the buggy vehicle may operate as a drone vehicle (i.e., untethered from the rail maintenance vehicle). The first rail vehicle 100 and the second rail vehicle 104 may be spaced 40′ to 200′ or more apart from each other during lining and leveling operations. The light source generated by the one or more projector devices 102 may be received at one or more receiver devices 104 disposed substantially adjacent to one another (i.e., a “receiver pair”). In some embodiments, additional receiver device 104 pairs are disposed at different points along the second rail vehicle 104 , e.g., a first receiver device 106 pair disposed on a first side of the tamper vehicle, a second receiver device 106 pair disposed on a second side of the tamper vehicle, and third and fourth receiver device 106 pairs disposed at a top of the tamper vehicle. In some embodiments, lining operations may only require one receiver device 106 per projector device 102 , while leveling operations may require two receiver devices 106 per projector device 102 .
The one or more projector devices 102 may be adapted to produce a uniform light source 124 resulting in a uniform “spot” such that the light intensity received into each receiver device 106 of a receiver pair is substantially equal. That is, each receiver device 106 of a receiver pair is adapted to receive substantially the same intensity of light 124 . In addition, the light source 124 is modulated in such a manner that each receiver device 106 of a receiver pair can detect the light source 124 . In this manner, the light source 124 has a predefined signature, which is detected by each receiver device 106 of a receiver pair. In some embodiments, the receiver pair may be tuned to work with a range of frequency and wavelength, e.g., substantially between 50 Hz and 2200 Hz. Accordingly, upon activation of the projector device 102 and receipt of the light source 124 at the receiver device 106 , the system of the present disclosure may recognize such light 124 as being emitted by the projector device 102 due to the amount of frequency and intensity of the light source. This is helpful for purposes of excluding other light sources, such as ambient light sources.
In some embodiments, the rail maintenance vehicle may be equipped with a plurality (e.g., three) shadow boards 108 generally positioned at an area adjacent to one or more work heads, such as linear actuators. In a surfacing operation, the track is lifted via clamps and actuators until the top shadow board 108 shields the light beam 124 emitted from the projector device 102 and the light 124 is not received at a pair of corresponding receiver devices 106 . Jacking/lifting would occur at the actuators until the shadow board 108 intersects the infrared light beam 124 . At this time, the lifting ceases while the work heads tamp the particular tie being worked upon. The total lift that is applied to the track may be controlled by changing the position of receiver device 106 . The position may be changed manually by using an up/down button on an operator keypad or automatically by a computer controlled surface ramp. Likewise, lining operations may also be performed in which the amount of correction is determined by the laterally placed (i.e., side) shadow boards 108 shielding the light beam 124 from reaching receiver device 106 pairs laterally disposed on the rail maintenance vehicle.
FIG. 13 illustrates a data processing system 200 for carrying out methods according to one embodiment of the present disclosure. The data processing system 200 may include a processor 202 configured to execute at least one program 204 stored in a memory 206 for the purposes of processing data to perform one or more of the techniques that are described herein. The processor 202 may be coupled to a communication interface 208 to receive remote sensing data. The processor 202 may also receive the sensing data via an input/output block 210 . In addition to storing instructions for the program, the memory 206 may store preliminary, intermediate, and final datasets involved in the techniques that are described herein. Among its other features, the computer or data processing system 200 may also include a display interface 212 and a display 214 that displays the various data that is generated as described herein. It will be appreciated that the computer or data processing system 200 shown in FIG. 12 is merely exemplary (for example, the display may be separate from the computer, omitted, etc.) in nature and is not limiting of the systems and methods described herein.
While various embodiments in accordance with the principles disclosed herein have been described above, it should be understood that they have been presented by way of example only, and are not limiting. Thus, the breadth and scope of the invention(s) should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.
It will be understood that the principal features of this disclosure can be employed in various embodiments without departing from the scope of the disclosure. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this disclosure and are covered by the claims.
Additionally, the section headings herein are provided for consistency with the suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a “Field of Invention,” such claims should not be limited by the language under this heading to describe the so-called technical field. Further, a description of technology in the “Background of the Invention” section is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Summary” to be considered a characterization of the invention(s) set forth in issued claims. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein.
The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.
As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.
As used herein, words of approximation such as, without limitation, “about”, “substantial” or “substantially” refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skilled in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as “about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%.
The term “or combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.
All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims. | Systems and methods for use in carrying out rail track corrections. A projector device is positioned on a vehicle deployed ahead of a rail maintenance vehicle and includes a Fresnel lens and a plurality of light emitting diodes arranged to provide a light beam that provides a uniform “spot.” The projector device modulates the light beam in such a manner that a pair of receiver receivers disposed on the rail maintenance vehicle can detect the light source and the light intensity and frequency of wavelength of light received into each receiver of a receiver pair is substantially equal. Recorded values may be used to triangulate the geometry of the section of track being worked, while a computer compares the previous section of track already corrected to the current section and makes calculations for desired corrections to be made at work heads on the rail maintenance vehicle. | 4 |
FIELD OF THE INVENTION
The present invention relates to an abrasive article including a backing plate and fastener press fit into the backing plate.
BACKGROUND OF THE INVENTION
A variety of abrasive articles are used to abrade or polish various substrates, including steel and other metals, woods, wood-like laminates, engineered boards, plastic, fiberglass, leather and ceramics. The abrasive articles are in any of a variety of forms, including sheets, discs, belts, wheels, and bands.
Many abrasive articles are used as discs in grinding assemblies. A typical abrasive sanding or grinding assembly includes: an annular back-up pad made from a resilient and reinforced material such as rubber or plastic and an abrasive disc having a backing plate and an abrasive surface (e.g., as provided by coated abrasive discs and non-woven abrasive discs) that includes abrasive material (e.g., abrasive grains and abrasive slurries). The abrasive disc and the back-up pad are typically mounted on a rotatable shaft of a tool and a retaining nut is used to secure the abrasive disc and back-up pad to the tool shaft. The shaft of the tool is inserted through holes in the center of the abrasive disc and back up pad. Frictional pressure is applied to the abrasive disc by screwing the nut onto the shaft to rotationally mount the disc to the back up pad by squeezing the abrasive disc against the back-up pad. In use, the shaft of the assembly is rotated and the abrasive surface of the disc is pressed against a substrate or workpiece with considerable force, to facilitate abrading of the substrate or workpiece. During the grinding process, the disc is subjected to severe stresses.
The abrasive material may completely cover or alternatively may only partially cover the surface of the backing plate. One particular style of abrasive disc uses an annular ring of abrasive material applied to the backing plate such that the inner radial boundary of the abrasive material is concentric with the backing plate. Examples of abrasive discs having an annulus of abrasive material include flap discs, non-woven surface conditioning discs, and grinding wheels.
The backing plates used in the abrasive articles (e.g., discs) are typically made of paper, certain polymeric materials such as phenolic impregnated fiberglass, cloth, nonwoven materials, vulcanized fiber, or combinations of these materials. Many of these materials, however, are not appropriate for certain applications because they are not of sufficient strength, flexibility, or impact resistance. Further, some of these materials age too rapidly. In some instances the materials are sensitive to liquids which are used as coolants and cutting fluids. As a result, a short useful product life can occur in certain applications.
One common backing plate material is vulcanized fiber. Vulcanized fiber backing plates are typically heat resistant and strong, which are advantageous characteristics when the coated abrasive is used in a grinding operation that imposes severe conditions of heat and pressure. For example, vulcanized fiber is used in certain grinding operations, such as weld grinding, contour grinding, and edge grinding, wherein the coated abrasive can be exposed to temperatures greater than 140° C. Vulcanized fiber backing plates, however are expensive, as well as hygroscopic, and thus sensitive to humidity.
Under extreme conditions of humidity (i.e., conditions of high and low humidity) vulcanized fiber typically either expands or shrinks, due, respectively, to water absorption or loss. As a result, an abrasive article made of vulcanized fiber tends to cup, causing a coated abrasive disc to curl either in a concave or a convex fashion. When this cupping or curling occurs, the affected abrasive disc does not lay flat against the back-up pad or support pad. This can effectively render the abrasive disc not useful.
To overcome the cupping and curling problems, other types of backing plate materials have been used, such as phenolic reinforced fiber backing plates. While these backing plates were typically more resistant to cupping or curling, the use of this type of material has led to other problems (e.g., cracking).
It is desirable to design abrasive discs to be quickly and easily removable from the rotatable shaft. One common technique for securing an abrasive disc to the shaft is typically accomplished by screwing a nut onto the rotary shaft of a tool, (thereby compressing the disc onto the back up pad). It is typically necessary to use tools (e.g., wrenches) to loosen and tighten the nut every time it is desirable to change the abrasive disc. The time required to change the abrasive disc can significantly limit the efficiency of the grinding task. To address this problem, other fasteners have been used. Unfortunately, such fasteners have not been conducive to quick and easy mounting and removal.
For example, a phenolic reinforced backing plate has been utilized in combination with an insert bonded or attached to a center hole formed through the back up pad. Another example is a metal grommet or nut that is adhesively bonded or mechanically attached to the backing plate. The manufacturing methods for making commercially useful embodiments utilizing either of these two types of mounting arrangements is relatively expensive. In part this expense can be attributed to the difficulty in drilling or punching holes or riveting the insert or grommet into backing plate without cracking the relatively brittle backing plate.
When relatively flexible backing plate materials are used, the backing plate tends to undesirably curl or otherwise become misshapen. Further, it can be more difficult to adequately secure the fastener to the backing plate.
There is a continuing need to develop manufacturing processes which provide an abrasive disc having adequate strength to withstand relatively harsh grinding environments which can be easily manufactured and mounted to and unmounted from a tool.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides an abrasive article comprising (a) a backing plate (e.g., generally circular backing plate) having a first major surface and a second, major surface opposite the first major surface, wherein the backing plate includes a central aperture extending therethrough, and wherein the backing plate comprises a thermoplastic binder material and fibrous reinforcing material, (b) an abrasive layer secured to the first major surface of the backing plate, and (c) a fastener press fitted to the backing plate so as to define the central aperture.
In another aspect the present invention provides a method of making an abrasive article comprising applying adhesive to a backing plate having a central aperture wherein the backing plate comprises a thermoplastic binder material and fibrous reinforcing material, disposing abrasive material onto the adhesive, disposing the backing plate onto a jig, disposing a fastener having tines so as to be concentric with the central aperture, and pushing the tines through the backing plate and folding the tines so as to fixably attach the fastener to the backing plate.
In another aspect, the present invention provides a method of abrading a surface, the method comprising:
providing an abrasive article comprising:
a backing plate having a first major surface and a second, major surface opposite the first major surface, wherein the backing plate includes a central aperture extending therethrough, and wherein the backing plate comprises a thermoplastic binder material and fibrous reinforcing material;
an abrasive layer secured to the first major surface of the backing plate; and a fastener press fitted to the backing plate so as to define the central aperture; attaching the abrasive article to a shaft (e.g., a rotating shaft of a tool) through the central aperture of the abrasive article; contacting at least a portion of the abrasive layer with a surface of a workpiece; and moving (e.g., rotating the shaft) the abrasive article relative to the surface of workpiece such that at least a portion of the workpiece is abraded by at least a portion of the abrasive layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further explained with reference to the drawing figures referenced below, wherein like structure in different embodiments of the invention is referred to by like numerals throughout the several views.
FIG. 1 is a perspective view of an exemplary abrasive article according to the present invention 10 mounted to a tool.
FIG. 2 is a plan view of the exemplary abrasive article according to the present invention as shown in FIG. 1 .
FIG. 3 is a cross-sectional view of the abrasive article shown in FIG. 2 , as taken along lines 3 — 3 .
FIG. 4 is a cross-sectional view of an additional exemplary abrasive article according to the present invention.
While the above-identified drawings set forth preferred embodiments of the present invention, other embodiments of the present invention are also contemplated, as noted in the discussion. This disclosure presents illustrative embodiments of the present invention by the way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within scope and spirit of the principles of this invention.
DETAILED DESCRIPTION
A perspective view of an exemplary abrasive disc according to the present invention is shown in FIG. 1 . Abrasive disc 10 is shown mounted to tool (as shown, an angle grinder) 12 . Abrasive disc 10 is threaded onto threaded shaft 14 of tool 12 . Shaft 14 defines a longitudinal axis 15 extending through the center of abrasive disc 10 . Abrasive disc 10 has an annular ring of abrasive material 20 (flap disc as shown) fixably mounted to generally circular backing plate 22 . Although abrasive disc 10 is shown mounted to angle grinder 12 , it would be understood that any tool having a rotational shaft could be used in conjunction with abrasive disc 10 (e.g., a drill). By “generally circular” it is meant that the abrasive disc is round in shape, and is typically circular, however other shapes (e.g., hexagonal) can be used without departing from the spirit and scope of the invention.
FIG. 2 shows a plan view of abrasive disc 10 according to the present invention. Fastener 24 is mounted to backing plate 22 so as to allow threading of abrasive disc 10 to shaft 14 of tool 12 . Backing plate 22 has grinding surface 22 A and tool surface 22 B (shown in FIG. 3 ). Fastener 24 can be, for example, a “threadless fastener” or sheet metal nut as is known in the art, as well as a Tinnerman nut fastening device, as described, for example, in U.S. Pat. No. 2,156,002 (Tinnerman), the disclosure of which is incorporated herein by reference. While the Tinnerman nut is the preferred fastening device, other types of fasteners may be used without departing from the spirit and scope of the invention. Preferred fastener 24 is a 1.5 inch (38.1 mm) quick-change button for mating with a ⅝ inch diameter by 11 thread per inch shaft (15.875 mm diameter by 0.43 threads per mm), manufactured by Metal Products Engineering, Los Angeles, C&A. Fastener 24 can be formed, for example, from 28 gauge steel, although other materials (e.g., brass or aluminum) may be used without departing from the spirit and scope of the invention. Central aperture 26 (shown in dotted lines in FIG. 2 ) extends through the center of backing plate 22 . Fastening apertures 29 are disposed coaxially about central aperture 26 , are radially spaced about central aperture 26 , and extend through fastener 24 .
A cross section of abrasive disc 10 shown in FIG. 2 is shown in FIG. 3 . Tool shaft 14 (in the dotted lines) is shown threaded into fastener 24 for illustrative purposes. The fastener includes annular flange 28 which is positioned so that top surface 30 of flange 28 engages grinding surface 22 A of backing plate 22 . Longitudinal engaging cylinder 31 , integral with annular flange 28 extends through central aperture 26 . Typically, back up pad assembly 14 A (shown in dotted lines) is used to support abrasive disc 10 when it is mounted on shaft 14 . Shaft 14 of the tool is threaded onto annular ring 31 A on cylinder 31 . Annular ring 31 A allows abrasive disc 10 to be quickly threaded on and off shaft 14 .
Abrasive material 20 is adhered to grinding surface 22 A of backing plate 22 . Abrasive material 20 can be shaped, for example, to form annulus 32 concentric with central aperture 26 . Annulus 32 has radially inner edge 34 and radially outer edge 36 . Adhesive 38 is disposed between abrasive material 20 and backing plate 22 to fix annulus 32 of abrasive material 20 to backing plate 22 . Inner bead 40 of adhesive 38 is disposed along the inner edge 34 of the annulus 32 , where the inner edge 34 is most proximate to backing 22 .
Fastener 24 is fixed to backing plate 22 by tines 46 which are integral with annular flange 28 . Tines 46 are bent through fastening apertures 29 , extending from grinding side 22 A of backing plate 22 to tool surface 22 B of backing plate 22 . That portion of each tine 46 which extends beyond tool surface 22 B is then bent inwardly (or outwardly) so as to extend radially along tool surface 22 B of backing plate 22 . Thus, tines 46 engage backing plate 22 so that fastener 24 is fixed, both rotationally and axially, to backing plate 22 . Fastening apertures 29 in backing plate 22 are typically formed when fastener 24 is mounted to backing plate 22 , as discussed below. Thus, fastener 24 should be formed from a material which is hard enough to push tines 46 through backing plate 22 while being flexible enough so that tines 46 can be bent along tool surface 22 B.
Mounting fastener 24 to backing plate 22 using tines 46 to secure fastener 24 in place allows the method of assembly of abrasive disc utilizing the present invention to be simplified. Abrasive disc 10 can be manufactured, for example, by selecting backing plate 22 either manually or automatically (using a machine) and placing backing plate 22 on a rotating spindle. The spindle can be rotated at a constant speed to facilitate the application of the adhesive. The adhesive can be applied, for example, manually or automatically. The amount of adhesive applied can be controlled, for example, by the speed of rotation, time of application, adhesive flow rate, and number of rows to be added to plastic backing plate 22 . Such factors can be influenced, for example, by the diameter of the backing plate and the type of abrasive material being adhered to the backing plate. Plastic backing plate 22 can then be indexed to another station, for example, manually or automatically, where, for example, depending on the type of abrasive disc to be formed, rectangular flaps of abrasive are added to the backing plate to form a flap disc, an abrasive ring of material is placed on the backing plate, or abrasive material is otherwise added to the backing plate. The abrasive material can be centered, or otherwise positioned, on the backing plate using, for example, a jig or press. Typically, the adhesive is a curable material which is cured prior to, or after, fastener 24 is added, for example, manually or automatically through central aperture 26 of backing plate 22 .
The backing plate 22 is placed in a riveting jig to orient central aperture 26 . Fastener 24 is placed in central aperture 26 and oriented to be substantially concentric with the circumference defined by aperture 26 . Pressure is applied to a riveting fixture (not shown) that functions to hold backing plate 22 and fastener 24 in place while pushing tines 46 through backing plate 22 , and to fold over tines 46 to effect a positive attachment between the backing plate 22 and fastener 24 .
The above described method is an exemplary method for fitting a fastener into the backing plate. It is understood that other methods are known in the art and may also be used without departing from the spirit and scope of the invention. For example, the fastener can be extended through the central aperture from the tool surface to the grinding surface. Additionally, for example, a Grit-Lock type fastener, as described for example, in U.S. Pat. No. 4,245,438, (van Buren, Jr.), the disclosure of which is incorporated herein by reference, can be mounted to the backing plate in substantially the same fashion as described above. Additionally, the order of assembly steps need not occur exactly as described above (e.g., fastener 24 can be secured to backing plate 22 before affixing the abrasive material).
Press fitting the fastener into the backing plate allows a quick change fastener to be economically inserted into the abrasive disc. The fastener is lightweight, concentric and rotationally fixed with respect to the disc so that the entire disc can be rotated to thread and unthread the fastener from the shaft, rather than by using wrenches, as was previously required. The result is a significant improvement in user convenience, allowing quick change of abrasive discs, which is desirable when each disc becomes worn or when a disc having different abrasive media is needed. Previous backing plates were made of relatively stiff, inflexible materials that could withstand the harsh grinding environment, however, attempts to press fit fasteners into these previous backing plates resulted in cracking the backing plates.
Although FIGS. 1-4 are representative of abrasive articles according to the present invention, other constructions having other shapes and forms are contemplated without departing from the spirit and scope of the invention. Abrasive articles (e.g., a disc) according to the present invention can possess a wide variety of backing plate shapes depending upon the end uses of the abrasive article. For example, the backing plate can be tapered so that the center portion of backing plate is thicker than the outer portions. The backing plate can have a uniform or non-uniform thickness. The backing plate can be embossed. The center of the backing plate can be depressed, or lower, than the outer portions. The edges of backing plate can be purposely bent to make a “cupped” disc if so desired. The edges of backing plate can also be smooth or scalloped.
The backing plate is sufficiently tough and heat resistant under severe grinding conditions such that the backing plate does not significantly disintegrate or deform from the heat generated during use (e.g., during a grinding, sanding, or polishing operation). One embodiment of a backing plate can operably withstand a temperature at the abrading interface of a workpiece of at least about 200° C. The phrase “at the abrading interface” in the context of temperature and pressure refers to the instantaneous or localized temperature and pressure the backing plate experiences at the contact point between the abrasive material on the article and the workpiece. Thus, the equilibrium or overall temperature of the backing plate can typically be less than the instantaneous or localized temperature at a contact point between the abrasive material and the workpiece during operation.
The backing plate is sufficiently tough such that it will not significantly crack or shatter from the forces encountered during manufacturing of the abrasive article as well as during use. That is, the backing plate is preferably able to operably withstand press fit insertion of the fastener as well as use in a grinding operation conducted with a pressure at the abrading interface of a workpiece of at least about 7 kg/cm 2 , preferably at least about 13.4 kg/cm 2 . Embodiments of the present invention utilize a backing plate that exhibits sufficient flexibility to withstand typical grinding conditions, and preferably severe grinding conditions. By “sufficient flexibility” it is meant that the backing plate can be bent and returned to its original shape without significant permanent deformation. That is, for some grinding operations, a “flexible” backing plate is one that is capable of flexing and adapting to the contour of the workpiece being abraded without permanent deformation of backing plate, yet is sufficiently strong to transmit an effective grinding force when pressed against the workpiece.
Embodiments of the present invention utilize a backing plate that possesses a flexural modulus of at least about 9000 kg/cm 2 under ambient conditions, with a sample size of 25.4 mm (width)×50.8 mm (span across the jig)×0.8-1.0 mm (thickness), and a rate of displacement of 4.8 mm/min, as determined by following the procedure outlined in the American Society for Testing and Materials (ASTM) D790 (published 1991) test method, the disclosure of which is incorporated herein by reference. Some embodiments of the backing plate possess a flexural modulus of between about 9000 kg/cm 2 and about 141,000 kg/cm 2 . Flexural moduli less than about 9000 kg/cm 2 are typically too low to provide the desired level of abrading performance. A backing plate with a flexural modulus greater than about 141,000 kg/cm 2 is generally too stiff to sufficiently conform to the surface of the workpiece.
Briefly, the ASTM D790 test method involves the use of either a three-point loading system utilizing center loading by means of a loading nose, which has a cylindrical surface, midway between two supports, each of which have a cylindrical surface; or a four-point loading system utilizing two load points equally spaced from their adjacent support points, with a distance between load points of either one-third or one-half of the support span. The specimen is deflected until rupture occurs or until the maximum strain has reached 0.05 mm/mm (i.e., a 5% deflection). The flexural modulus (i.e., tangent modulus of elasticity) is determined by the initial slope of the load vs. deflection curve.
Embodiments of the present invention utilize a backing plate that exhibit sufficient flexural toughness. By “sufficient flexural toughness” it is meant that backing plate is sufficiently stiff to withstand insertion of the fastener during assembly of the abrasive article as well as grinding conditions, but not undesirably brittle such that cracks are formed in the backing plate, thereby decreasing its structural integrity.
The desirable toughness of backing plate can also be demonstrated by measuring the impact strength of the backing plate. The impact strength can be measured by following the test procedures outlined in ASTM D256 (published 1990, version b) or D3029 (published 1990) test methods, the disclosures of which are incorporated herein by reference. These methods involve a determination of the force required to break a standard test specimen of a specified size. The backing plate preferably has an impact strength (i.e., a Gardner Impact value) or mean failure energy of at least about 0.4 Joules for a 0.89 mm thick sample under ambient conditions. More preferably, a backing plate utilized in the present invention has a Gardner Impact value of at least about 0.9 Joules for a 0.89 mm thick sample under ambient conditions, and most preferably at least about 1.6 Joules for a 0.89 mm thick sample under ambient conditions.
Embodiments of the present invention utilize a backing plate having desirable tensile strength. Tensile strength is a measure of the greatest longitudinal stress a substance can withstand without tearing apart. It demonstrates the resistance to rotational failure and “snagging” as a result of high resistance at discontinuities in the workpiece that the abrasive article might contact during operation. A desirable tensile strength is defined as at least about 17.9 kg/cm of width at about 150° C. for a sample thickness of about 0.75-1.0 mm.
Embodiments of the present invention utilize a backing plate that exhibits appropriate shape control and are sufficiently insensitive to environmental conditions, such as humidity and temperature. By this it is meant that preferred backing plates possess the above-listed properties under a wide range of environmental conditions. Preferably, the backing plate possess the above-listed properties within a temperature range of about 10-30° C., and a humidity range of about 30-50% relative humidity (RH). More preferably, the backing plate possess the above-listed properties under a wide range of temperatures (i.e., from below 0° C. to above 100° C.) and a wide range of humidity values (i.e., from below 10% RH to above 90% RH).
Under extreme conditions of humidity (i.e., conditions of high humidity, greater than about 90% RH, and low humidity, less than about 10% RH), the backing plate is not significantly affected by either expansion or shrinkage due, respectively, to water absorption or loss. As a result, abrasive articles utilized in the present invention will not significantly deform (e.g., cup or curl in either a concave or a convex fashion).
The backing plate contains a thermoplastic binder material ( 25 as shown in FIG. 3 ) and an effective amount of a fibrous reinforcing material ( 27 as shown in FIG. 3 ). By an “effective amount” of a fibrous reinforcing material, it is meant that the backing plate contains a sufficient amount of the fibrous reinforcing material to impart at least improvement in heat resistance, toughness, flexibility, stiffness, shape control, etc., discussed above.
Preferably, the amount of the thermoplastic binder material in the backing plate is within a range of about 60-99%, more preferably within a range of about 62-95%, and most preferably within a range of about 65-85%, based upon the total weight of the backing plate. The remainder of a typical, backing plate is primarily the fibrous reinforcing material with few, if any, voids throughout the hardened backing plate composition. Although there can be additional components added to the binder composition, the backing plate utilized in the present invention primarily contains a thermoplastic binder material and an effective amount of a fibrous reinforcing material.
Typically, the higher the content of the reinforcing material, the stronger backing plate is. If there is too much fibrous reinforcing material, however, the backing plate may be too brittle for desired applications. By proper choice of thermoplastic binder material and fibrous reinforcing material, such as, for example, a polyamide thermoplastic binder and glass reinforcing fiber, considerably higher levels of the binder can be employed to produce a hardened backing plate composition with few if any voids and with the properties as described above.
Optionally, the hardened material forming the backing plate possesses a void volume of less than about 0.1%. Herein “void volume” means a volume within the backing plate filled with air or gas (i.e., absent solid material). The percent void volume can be determined by comparing the actual density (mass/volume) of the hardened backing plate composition to the total calculated density of the various components. That is, the percent void volume equals [1-(actual density/calculated density)]×100.
A thermoplastic binder material is a polymeric material (e.g., an organic polymeric material) that softens and melts when exposed to elevated temperatures and generally returns to its original condition (i.e., its original physical state) when cooled to ambient temperatures. During the manufacturing process, the thermoplastic binder material is heated above its softening temperature, or in some instances above its melting temperature, to cause it to flow and form the desired shape of the abrasive article. After the backing plate is formed, the thermoplastic binder is cooled and solidified. In this way the thermoplastic binder material can be molded into various shapes and sizes.
The backing plate can be formed, for example, by shaping or molding the thermoplastic material using conventional molding techniques such as injection molding. Use of such molding techniques can reduce the amount of materials wasted in construction, relative to conventional “web” processes. Injection molding can also allow for the backing plate to be more concentric than what was previously available. Making the backing plate concentric aids in minimizing or eliminating wobbling during use of the abrasive disc. Additionally, for example, a concentric backing plate may allow tighter manufacturing tolerances to be kept (i.e., when mounting the abrasive material and the fastener). Additionally, for example, higher concentricity of the abrasive disc can minimize or prevent curling of the edges which can occur during grinding, thereby increasing the efficiency of the abrasive disc.
Molding technologies can also allow for controlling shrinkage of the backing plate during manufacturing, and allow for molding structural members (e.g., ridges) into the backing plate, (as is known in the art), to help minimize or prevent warpage.
Web manufacturing processes can also be used to form the backing plate. In a typical web manufacturing process, the backing plate for the abrasive disc is made in a continuous web form and then cut into the desired disc shape. Although injection molding techniques can be used to produce backing plates for the backing plates utilized in the present invention (to provide tighter manufacturing tolerances as well as avoid waste) this is not intended to mean that conventional “web” processes cannot be used. On the contrary, using conventional web processes to form the backing plate may be necessary when using certain embodiments of the backing plate (e.g., thermoplastic impregnated cloths).
Moldable thermoplastic materials utilized in the present invention include those having a high melting temperature, good heat resistance properties, and good toughness properties such that the hardened backing plate composition containing these materials operably withstands abrading conditions and mechanical insertion of the fastener without substantially deforming or disintegrating.
Hardened backing plate compositions include those that can withstand a temperature of at least about 200° C. and a pressure of at least about 7 kg/cm 2 , preferably at least about 13.4 kg/cm 2 , at the abrading interface of a workpiece. Moldable thermoplastic materials include those having a melting point of at least about 200° C., preferably at least about 220° C. Additionally, the melting temperature of the tough, heat resistant, thermoplastic material is preferably sufficiently lower (i.e., at least about 25° C. lower) than the melting temperature of the fibrous reinforcing material. In this way, the fibrous reinforcing material is not adversely affected during the molding of the binder. Suitable thermoplastic materials also include those that are generally insoluble in an aqueous environment, at least because of the desire to use the abrasive disc on wet surfaces.
Examples of thermoplastic materials suitable for preparations of backing plates in abrasive articles according to the present invention include polycarbonates, polyetherimides, polyesters, polysulfones, polystyrenes, acrylonitrile-butadiene-styrene block copolymers, acetal polymers, polyamides, and combinations thereof. Polyamide materials are preferred thermoplastic binder materials, at least because they are inherently tough and heat resistant, typically provide good adhesion to the preferred adhesive resins without priming, and are relatively inexpensive.
A preferred thermoplastic material from which the backing plate is formed is a polyamide resin material, which is characterized by having an amide group, i.e., —C(O)NH—. Various types of polyamide resin materials (i.e., nylons) can be used, such as nylon 6/6 or nylon 6. Nylon 6/6 is a condensation product of adipic acid and hexamethylenediamine. Nylon 6/6 has a melting point of about 264° C. and a tensile strength of about 770 kg/cm 2 . Nylon 6 is a polymer of ε-caprolactam. Nylon 6 has a melting point of about 223° C. and a tensile strength of about 700 kg/cm 2 .
Examples of commercially available nylon resins useable as backing plates in articles according to the present invention include those available under the trade designations “VYDYNE” from Monsanto, St. Louis, Mo.; “ZYTEL” and “MINLON” both from DuPont, Wilmington, Del.; “TROGAMID T” from Huls America, Inc., Piscataway, N.J.; “CAPRON” from Allied Chemical Corp., Morristown, N.J.; “NYDUR” from Mobay, Inc., Pittsburgh, Pa.; and “ULTRAMID” from BASF Corp., Parsippany, N.J. Although a mineral-filled thermoplastic material can be used, such as the mineral-filled nylon 6 resin available under the trade designation “MINLON.”.
Once again, besides the thermoplastic binder material, backing plates utilized in the present invention include an effective amount of fibrous reinforcing material. As discussed, an “effective amount” of a fibrous reinforcing material is a sufficient amount to impart at least improvement in the physical characteristics of the backing plate (i.e., heat resistance, toughness, flexibility, stiffness, shape control, etc.). Additionally, not so much fibrous reinforcing material is used as to give rise to any significant number of voids and detrimentally affect the structural integrity of the backing plate. Preferably, the amount of the fibrous reinforcing material in the backing plate is within a range of about 1-45%, more preferably within a range of about 5-40%, and most preferably within a range of about 15-35%, based upon the weight of the backing plate.
The fibrous reinforcing material can be in the form of individual fibers or fibrous strands, or in the form of a fiber mat or web. The fibrous reinforcing material can be, for example, in the form of individual fibers or fibrous strands for advantageous manufacture. Fibers are typically defined as fine thread-like pieces with an aspect ratio of at least about 100:1. The aspect ratio of a fiber is the ratio of the longer dimension of the fiber to the shorter dimension. The mat or web can be either in a woven or nonwoven matrix form. A nonwoven mat is a matrix of a random distribution of fibers made by bonding or entangling fibers by mechanical, thermal, or chemical means.
Examples of useful reinforcing fibers in applications of the present invention include metallic fibers or nonmetallic fibers. The nonmetallic fibers include glass fibers, carbon fibers, mineral fibers, synthetic or natural fibers formed of heat resistant organic materials, or fibers made from ceramic materials. Preferred fibers for applications of the present invention include nonmetallic fibers, and more preferred fibers include heat resistant organic fibers, glass fibers, or ceramic fibers.
“Heat resistant” organic fibers, refer to organic fibers that are resistant to melting, or otherwise breaking down, under the conditions of manufacture and use of the backing plates. Examples of useful natural organic fibers include wool, silk, cotton, or cellulose. Examples of useful synthetic organic fibers include polyvinyl alcohol fibers, polyester fibers, rayon fibers, polyamide fibers, acrylic fibers, aramid fibers, or phenolic fibers. The preferred organic fiber for applications of the present invention is aramid fiber. Such fiber is commercially available from the DuPont Co., Wilmington, Del. under the trade designations of “KEVLAR” and “NOMEX.”
Generally, any ceramic fiber is useful in applications of the present invention. Examples of ceramic fibers suitable for the present invention include those marketed under trademark designations “NEXTEL 312,440,610,650 and 720” by the 3M Company, St. Paul, Minn.
The most preferred reinforcing fibers for applications of the present invention are glass fibers, at least because they impart desirable characteristics to the coated abrasive articles and are relatively inexpensive. Furthermore, suitable interfacial binding agents exist to enhance adhesion of glass fibers to thermoplastic materials. Glass fibers are typically classified using a letter grade. For example, E glass (for electrical) and S glass (for strength). Letter codes also designate diameter ranges, for example, size “D” represents a filament of diameter of about 6 micrometers and size “G” represents a filament of diameter of about 10 micrometers. Useful grades of glass fibers include both E glass and S glass of filament designations D through U. Preferred grades of glass fibers include E glass of filament designation “G” and S glass of filament designation “G.”Commercially available glass fibers are available, for example, from Specialty Glass Inc., Oldsmar, Fla.; Owens-Corning Fiberglass Corp., Toledo, Ohio; and Mo-Sci Corporation, Rolla, Mo.
If glass fibers are used, it is preferred that the glass fibers are accompanied by an interfacial binding agent (i.e., a coupling agent, such as a silane coupling agent) to improve the adhesion to the thermoplastic material. Examples of silane coupling agents include those marketed under the trade designations “Z-6020” and “Z-6040,” by Dow Corning Corp., Midland, Mich.
Advantages can be obtained through use of fiber materials of a length as short as 100 micrometers, or as long as needed for one continuous fiber. Preferably, the length of the fiber is from about 0.5 mm to about 50 mm, more preferably from about 1 mm to about 25 mm, and most preferably from about 1.5 mm to about 10 mm. The fibrous reinforcing material denier, i.e., degree of fineness, for preferred fibers ranges from about 1 to about 5000 denier, typically between about 1 and about 1000 denier. More preferably, the fiber denier will be between about 5 and about 300, and most preferably between about 5 and about 200. It is understood that the denier is strongly influenced by the particular type of fibrous reinforcing material employed.
The fibrous reinforcing material can be distributed throughout the thermoplastic material (i.e., throughout the body of the backing plate, rather than merely embedded in the surface of the thermoplastic material). This is for the purpose of imparting improved strength and wear characteristics throughout the body of the backing plate. A construction wherein the fibrous reinforcing material is distributed throughout the thermoplastic binder material of the backing plate body can be made using either individual fibers or strands, or a fibrous mat or web structure of dimensions substantially equivalent to the dimensions of the finished backing plate. Although in this preferred embodiment distinct regions of the backing plate may not have fibrous reinforcing material therein, it is preferred that the fibrous reinforcing material be distributed substantially uniformly throughout the backing plate.
The fibrous reinforcing material can be oriented as desired for advantageous applications of the present invention. That is, the fibers can be randomly distributed, or they can be oriented to extend along a direction desired for imparting improved strength and wear characteristics. Typically, if orientation is desired, the fibers should generally extend transverse (±20°) to the direction across which a tear is to be avoided.
The backing plates can further include an effective amount of a toughening agent. This will be preferred for certain applications. A primary purpose of the toughening agent is to increase the impact strength of backing plate. By “an effective amount of a toughening agent” it is meant that the toughening agent is present in an amount to impart at least improvement in backing plate toughness without it becoming too flexible. Backing plates utilized in the present invention preferably include sufficient toughening agent to achieve the desirable impact test values listed above.
Embodiments of the present invention can utilize a backing plate comprising between about 1% and about 30% of the toughening agent, based upon the total weight of the backing plate. Preferably, the toughening agent (i.e., toughener) is present in an amount of about 5-15 wt- %. The amount of toughener present in a backing plate may vary depending upon the particular toughener employed. For example, the fewer elastomeric characteristics a toughening agent possesses, the larger the quantity of toughening agent may be required to impart desirable properties to the backing plates.
Examples of toughening agents that impart desirable stiffness characteristics to backing plate of the present invention include rubber-type polymers (e, natural rubber and synthetic elastomers) and plasticizers.
Examples of toughening agents (i.e., rubber tougheners and plasticizers) include: toluenesulfonamide derivatives (such as a mixture of N-butyl- and N-ethyl-p-toluenesulfonamide, commercially available, for example, from Akzo Chemicals, Chicago, Ill., under the trade designation “KETJENFLEX 8”); styrene butadiene copolymers; polyether backbone polyamides (commercially available, for example, from Atochem, Glen Rock, N.J., under the trade designation “PEBAX”); rubber-polyamide copolymers (commercially available, for example, from DuPont, Wilmington, Del., under the trade designation “ZYTEL FN”); and functionalized triblock polymers of styrene-(ethylene butylene)-styrene (commercially available, for example, from Shell Chemical Co., Houston, Tex., under the trade designation “KRATON FGI901”); and mixtures thereof. Of this group, rubber-polyamide copolymers and styrene-(ethylene butylene)-styrene triblock polymers are more preferred, at least because of the beneficial characteristics they impart to backing plates and the manufacturing process of the present invention. Rubber-polyamide copolymers are the most preferred, at least because of the beneficial impact and grinding characteristics they impart to backing plates utilized in the present invention.
If the backing plate is made by injection molding, typically the toughener is added as a dry blend of toughener pellets with the other components. The process usually involves tumble-blending pellets of toughener with pellets of fiber-containing thermoplastic material. A more preferred method involves compounding the thermoplastic material, reinforcing fibers, and toughener together in a suitable extruder, pelletizing this blend, then feeding these prepared pellets into the injection molding machine. Commercial compositions of toughener and thermoplastic material are available, for example, under the designation “ULTRAMID” from BASF Corp., Parsippany, N.J. Specifically, “ULTRAMID B3ZG6” is a nylon resin containing a toughening agent and glass fibers that is useful in the present invention.
Besides the materials described above, the backing plate utilized in the present invention can include effective amounts of other materials or components depending upon the end properties desired. For example, the backing plate can include a shape stabilizer (i.e., a thermoplastic polymer with a melting point higher than that described above for the thermoplastic binder material). Suitable shape stabilizers include, but are not limited to, poly(phenylene sulfide), polyimides, and polyaramids. An example of a preferred shape stabilizer is polyphenylene oxide nylon blend commercially available, for example, from General Electric, Pittsfield, Mass., under the trade designation “NORYL GTX 910.” If a phenolic-based make coat and size coat are employed in the coated abrasive construction, however, the polyphenylene oxide nylon blend is not preferred because of nonuniform interaction between the phenolic resin adhesive layers and the nylon, resulting in reversal of the shape-stabilizing effect. This nonuniform interaction results from a difficulty in obtaining uniform blends of the polyphenylene oxide and the nylon.
Other such optional materials that can be added to the backing plate for certain applications of the present invention include inorganic or organic fillers. Inorganic fillers are also known as mineral fillers. A filler is defined as a particulate material, typically having a particle size less than about 100 micrometers, preferably less than about 50 micrometers. Examples of useful fillers for applications of the present invention include carbon black, calcium carbonate, silica, calcium metasilicate, cryolite, phenolic fillers, or polyvinyl alcohol fillers. If a filler is used, it is theorized that the filler fills in between the reinforcing fibers and may prevent crack propagation through the backing plate. Typically, a filler would not be used in an amount greater than about 20%, based on the weight of the backing plate. Preferably, at least an effective amount of filler is used. Herein, the term “effective amount” in this context refers to an amount sufficient to fill but not significantly reduce the tensile strength of the hardened backing plate.
Other useful optional materials or components that can be added to the backing plate for certain applications of the present invention include pigments, oils, anti-static agents, flame retardants, heat stabilizers, ultraviolet stabilizers, internal lubricants, antioxidants, and processing aids. One would not typically use more of these components than needed for desired results.
Other examples of suitable materials for the backing plate are described in U.S. Pat. No. 5,316,812, (Stout et al.) and U.S. Pat. No. 5,669,941 (Peterson), the disclosures of which are incorporated by herein by reference.
Utilizing the binder in combination with the fibrous reinforcing material provides strength and flexibility to the backing plate material which allows it to be thinner and lighter than backing plates used in previous abrasive discs (e.g., thermoplastic impregnated cloth). The mechanical properties of the backing plate in the inventive abrasive disc allow the fastener to be press fitted into the backing plate without cracking the backing plate while the backing plate remains strong enough to withstand the harsh grinding environment.
Preferably, the backing plate is between 3 inches (7.62 cm) to 7 inches (17.78 cm) in diameter and is substantially circular in shape, since these are standard industry sizes for abrasive discs. However, a person skilled in the art would realize that other sizes may be contemplated without departing from the spirit and scope of the invention. The backing plate is typically formed to a thickness of from approximately 20 mils (0.51 mm) to approximately 70 mils (1.78 mm), more preferably from approximately 40 mils (1.02 mm) to approximately 55 mils (1.40 mm), and most preferably to approximately 50 mils (1.27 mm).
Thin backing plates have additional advantages. For example, making an abrasive disc with a thin, strong backing plate decreases the weight of the abrasive disc. Higher RPM's are required in many industrial grinding applications. With a lighter abrasive disc, the force required to spin the abrasive disc is reduced. Thus, the revolutions per minute (RPM's) which can be generated by the same amount of force is increased. Additionally, decreasing the weight of the abrasive disc will reduce the weight borne by the operator, reducing worker fatigue. Finally, thinner backing plates require less material to produce, and are inherently cheaper.
Backing plates utilized in the present invention can allow the use of lightweight threadless fasteners that can be punched into the backing plate. Molding structural members into the backing plate increases the structured strength of the backing plate without substantially increasing the weight of the backing plate. All these features allow decreased overall weight of the tool, decreasing worker fatigue.
Abrasive material used in abrasive articles according to the present can be shaped to form an annulus of material mounted on the backing plate. In one embodiment of the inventive abrasive disc, abrasive material is coated onto individual flaps ( 50 shown in FIG. 2 ) which are overlapped and adhered to the backing plate, forming a “flap disc” as is known in the art and illustrated in FIG's 1 - 3 . The flaps are arranged such that when the abrasive disc is attached to the tool ( 12 as shown in FIG. 1 ) and brought into contact with a work surface the rotation of the abrasive disc causes the abrasive flaps to abrade the work surface.
Other embodiments of abrasive articles according to the present invention can use different abrasive material such as coated abrasives, bonded abrasives and non-woven abrasives, all of which are known in the art.
Another example of an exemplary abrasive disc according to the present invention is shown in FIG. 4 . Abrasive disc, 110 includes abrasive material 122 , fastener 124 , and adhesive 138 (including inner bead 140 of adhesive 138 ) as described with respect to FIGS. 1-3 . Abrasive article 120 in FIG. 4 is illustrated as a nonwoven abrasive. Nonwoven abrasive products (illustrated, for example, in FIG. 4 ) typically include an open porous lofty polymer filament structure having abrasive grains distributed throughout the structure and adherently bonded therein by an organic binder. Examples of filaments include polyester fibers, polyamide fibers, and polyaramid fibers.
Techniques for making abrasive layers, materials, etc., are known in the art, as are materials for making the same (see, e.g., U.S. Pat. No. 4,314,827 (Leitheiser et al.); U.S. Pat. No. 4,518,397 (Leitheiser et al.); U.S. Pat. No. 4,623,364 (Cottringer el al.); U.S. Pat. No. 4,744,802 (Schwabel); U.S. Pat. No. 4,770,671 (Monroe et al.); U.S. Pat. No. 4,881,951 (Wood et al.); U.S. Pat. 5,011,508 (Wald et al.); U.S. Pat. No. 5,139,978 (Wood); U.S. Pat. No. 5,201,916 (Berg et al.); U.S. Pat. No. 5,366,523 (Rowenhorst et al.); U.S. Pat. No. 5,429,647 (Larmie); U.S. Pat. No. 5,498,269 (Larmie); U.S. Pat. No. 5,551,963 (Larmie); U.S. Pat. No. 4,311,489 (Kressner); U.S. Pat. No. 4,652,275 (Bloecher et al.); U.S. Pat. No. 4,799,939 (Bloecher et al.); U.S. Pat. No. 4,734,104 (Broberg); U.S. Pat. 4,737,163 (Larkey); U.S. Pat. No. 5,203,884 (Stout et al.); U.S. Pat. No. 5,496,386 (Broberg et al.); U.S. Pat. No. 5,609,706 (Benedict et al.); U.S. Pat. No. 5,961,674 (Gagliardi et al.); U.S. Pat. No. 4,543,107 (Rue); and U.S. Pat. No. 2,958,593 (Hoover et al.), the disclosures of which are incorporated herein by reference).
Suitable organic binders for making abrasive layers include thermosetting organic polymers. Examples of suitable thermosetting organic polymers include phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, urethane resins, acrylate resins, polyester resins, aminoplast resins having pendant α,β-unsaturated carbonyl groups, epoxy resins, acrylated urethane, acrylated epoxies, and combinations thereof. The binder and/or abrasive product may also include additives such as fibers, lubricants, wetting agents, thixotropic materials, surfactants, pigments, dyes, antistatic agents (e.g., carbon black, vanadium oxide, graphite, etc.), coupling agents (e.g., silanes, titantates, zircoaluminates, etc.), plasticizers, suspending agents, and the like. The amounts of these optional additives are selected to provide the desired properties. The coupling agents can improve adhesion to the abrasive particles and/or filler. The binder chemistry may be thermally cured, radiation cured or combinations thereof. Additional details on binder chemistry may be found, for example, in U.S. Pat. No. 4,588,419 (Gaul et al.), U.S. Pat. No. 4,751,137 (Tumey et al.), and U.S. Pat. No. 5,436,063 (Follett et al.), the disclosures of which are incorporated herein by reference.
Typically, the abrasive particles have a moh's hardness of at least 5, 6, 7, 8, 9, or even 10. Suitable abrasive grains include fused aluminum oxide (including white fused alumina, heat-treated aluminum oxide and brown aluminum oxide), silicon carbide, boron carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina-zirconia, and sol-gel-derived abrasive particles, and the like. The sol-gel-derived abrasive particles may be seeded or non-seeded. Likewise, the sol-gel-derived abrasive particles may be randomly shaped or have a shape associated with them, such as a rod or a triangle. Examples of sol gel abrasive particles include those described in U.S. Pat. No. 4,314,827 (Leitheiser et al.), U.S. Pat. No. 4,518,397 (Leitheiser et al.), U.S. Pat. No. 4,623,364 (Cottringer et al.), U.S. Pat. No. 4,744,802 (Schwabel), U.S. Pat. No. 4,770,671 (Monroe et al.), U.S. Pat. No. 4,881,951 (Wood et al.), U.S. Pat. No. 5,011,508 (Wald et al.), U.S. Pat. No. 5,090,968 (Pellow), U.S. Pat. No. 5,139,978 (Wood), U.S. Pat. No. 5,201,916 (Berg et al.), U.S. Pat. No. 5,227,104 (Bauer), U.S. Pat. No. 5,366,523 (Rowenhorst et al.), U.S. Pat. No. 5,429,647 (Larmie), U.S. Pat. No. 5,498,269 (Larmie), and U.S. Pat. No. 5,551,963 (Larmie), the disclosures of which are incorporated herein by reference. The abrasive grains may also be present in the form of abrasive agglomerates.
For the embodiments of the abrasive discs shown in FIGS. 1-4 , the abrasive material 20 and 120 is adhered to the backing plate 22 and 122 by adhesive 38 and 138 . Radial and axial thickness of the abrasive 20 and 120 may vary according to the desired application and the type of abrasive material.
Abrading with abrasive articles according to the present invention may be done dry or wet. For wet abrading, the liquid may be introduced or supplied in the form of a light mist to complete flood: Examples of commonly used liquids include: water, water-soluble oil, organic lubricant, and emulsions. The liquid may serve to reduce the heat associated with abrading and/or act as a lubricant. The liquid may contain minor amounts of additives such as bactericide, antifoaming agents, and the like.
Abrasive articles according to the present invention may be used to abrade workpieces such as aluminum and aluminum alloys, carbon steels, mild steels, tool steels, stainless steel, hardened steel, brass, titanium, glass, ceramics, wood, wood-like materials, plastics, paint, painted surfaces, organic coated surfaces and the like.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | Abrasive article including a backing plate. Backing plate has a first major surface and a second opposite major surface. A central aperture extends through backing plate. An abrasive layer is secured to the first major surface of backing plate. A fastener is press fit to backing plate so as to define the central aperture. | 1 |
OBJECT OF THE PATENT
The object of the patent is to furnish a lightning conduction system for current wind turbine blades. The new lightning system is achieved by adding a device that reduces the current fraction of the lightning transmitted through the carbon fiber laminates.
BACKGROUND OF THE INVENTION
Given the height of the wind turbines and their erection in elevated regions lacking other elements having similar heights, there is a high risk of being struck by lightning, especially in the blades. With this in mind, blades must be equipped with a lightning protection system, and any other additional system installed in the blade containing conductor elements (metal parts, sensors, beacon systems, etc.) must be protected against direct impacts of lightning bolts and indirect effects of the electromagnetic field induced by the bolt current.
The primary components of the lightning protection system for wind turbine blades are a series of metal receptors mounted on the surface of the blade and a cable conductor to transit the bolt from the receptors to the blade root.
The evolution of wind turbines together with the growth in their provided power have led to new generations of wind turbines having ever-increasing dimensions insofar as tower height and rotor diameter. Blade lengthening necessitates an increase in rigidity. The use of a larger quantity of carbon fiber-based laminates in blade production is common to achieve this rigidity. However, carbon fiber laminates are conductors and must therefore be connected in parallel with the lightning protection system conductor cable to prevent internal arcing between the cable and the laminates and direct lightning bolt strikes on the carbon laminate.
In this regard, international patent WO2006051147, which presents a “lightning conductor system for wind generator blades comprising carbon fibre laminates”, can be cited since the use of carbon fiber in blade beam construction requires that this material be equipotentialized with the lightning conductor system. To do so, the primary cable of the lightning conductor system is furnished with bypasses for connections directly with the carbon fiber laminates. These auxiliary cables are connected with a bolted joint to a metal plate in direct contact with the carbon fiber layers. The electrical connection can be improved with the use of additional conductor resins in the joint area.
Notwithstanding this solution, the distribution of current transmitted across the cable and carbon laminates are not controlled, which could make the transfer of current across the carbon without damaging it even more difficult, thus necessitating a device to connect the carbon fiber laminates in parallel with the cable conductor of the system and to control the current circulating through the carbon fiber as in the proposal for the present invention.
DESCRIPTION
The longer lengths of blades currently in use call for suitable reinforcement of the internal blade beam (structural element withstanding the largest stresses). The beam is thus manufactured with an increasing number of carbon fiber layers which could result in a problem (since thicker and wider laminates offer less resistance to the passage of current) in conducting strong currents through the cable coming down from the lightning conductor system instead of the beam laminate.
An object of this invention is to improve the current lightning conductor system for blades of a lesser length and with a smaller amount of carbon fiber in the laminates on the blade beam.
Another object of this invention is to include a device in at least one of the existing connections between the laminates of the carbon fiber and the conductor cable of the lightning conductor system to control the current fraction of the bolt transmitted through the carbon fiber laminates.
Another object of the invention is the current control device formed by a highly conductive element, thus reducing the current fraction of the bolt transmitted through the fiber carbon laminates.
The foregoing is attained by connecting the carbon fiber laminate with the conductor cable. Thus, the lightning protection system is converted into a two-branched circuit in parallel: one branch formed by the cable conductor, of low resistance and high inductance, and the other branch formed by the carbon laminate, having high resistance and low inductance. When lightning strikes one of the receptors on the blade, the lightning protection system must evacuate bolt current, whose waveform is characterized by having a first phase in which the current rises steeply, followed by a second phase where the current drops slowly. When this current is injected into the circuit formed by the carbon laminate connect in parallel to the cable, the current is distributed as follows:
During the steep rise phase, most of the current is transmitted by the conductor with less inductance (carbon laminate) During the gradual drop phase, most of the current is transmitted by the conductor with less resistance (conductor cable)
With the current distribution described above, the carbon laminate undergoes a large current peak at the beginning of the discharge, whereas, based on the increased size of the blades, the inductance of the carbon laminates (wider and thicker) decreases. This provokes the fraction of the current conducted by the carbon to increase. The transmission of a lightning bolt discharge is simple to carry out in metal elements, yet complicated in carbon laminates, which contain resins that degenerate at temperatures between 100° C. and 200° C.).
The main advantage of using the high-inductance device placed in the connection between the carbon laminates and the conductor cable is that it reduces the passage of current through the carbon laminate and favors conduction through the metal cable.
Another advantage is that it is unnecessary to utilize a device in the two connections between the carbon and the conductor cable (at the beginning and end of the laminate); a mere device used at one of the two connections will suffice.
DESCRIPTION OF THE FIGURES
FIG. 1 represents the relative position between the carbon flanges and the cable that runs through the core in a section of the blade.
FIG. 2 shows the plate making the connection with the carbon fiber, as well as the bypasses with auxiliary cables.
FIG. 3 shows the detail of the connection between the plate and the carbon fiber, and the bypasses of the auxiliary cable to the primary cable with the inclusion of the high-inductance device.
DESCRIPTION OF THE PREFERENTIAL EMBODIMENT
As shown in FIG. 1 , the lightning conduction system in the blade ( 1 ) with carbon fiber laminates ( 2 ), object of the invention, employs a lightning conduction system based on a primary cable ( 6 ) to which, additionally, some bypasses are fitted in order to connect it directly with the carbon fiber laminates ( 2 ) thereby ensuring the equipotentiality of both systems.
As shown in FIG. 2 , the bypasses are made with two connections to each one of the two carbon fiber laminates ( 2 ), the one corresponding to the upper part of the beam ( 10 ) and the one corresponding to the lower part of the beam, represented in the previous figure. These laminates are located on the two sides that are affixed to the shells of the blade known as the flanges ( 4 ). One connection is made in the beam root area and the other at the tip area so that the flanges ( 4 ) of the beam become alternative paths for the bolt. The differentiating characteristic of the system lies in the form that connections are made between the primary cable ( 6 ) and the carbon laminates ( 2 ), this is achieved by bypasses from the primary cable ( 6 ) due to small pieces of auxiliary cable ( 5 ) connected with a bolted joint to a metal plate ( 3 ). This metal plate ( 3 ) is designed to make the direct connection with the carbon ( 2 ). The plates ( 3 ) are mounted during the beam lamination process onto the beam's layers of carbon fiber and are subsequently covered with glass or carbon fiber layers employed in the later lamination of the beam. The plates ( 3 ) adhere to the laminates in the normal curing of the beam thus achieving a mechanically robust union with the beam and electrically well connected with the carbon fiber ( 2 ).
As shown in FIG. 3 , according to the practical embodiment of the invention, this is a typical blade beam comprising two cores ( 8 ) and two flanges ( 4 ). The carbon laminates ( 2 ) used to stiffen the beam are employed in the flanges ( 4 ) of the beam ( 10 ). For this purpose, these laminates ( 2 ) are connected to the drop cable or primary cable ( 6 ) through an auxiliary conductor element ( 5 ) and connects using a bolted joint to the metal plate ( 3 ) and to the device ( 12 ) capable of reducing the passage of current across the carbon laminate ( 2 ) and thus favoring the conduction across the primary cable ( 6 ). The device ( 12 ) redistributes the current within the blade and not outside of it, hence protecting the carbon fiber ( 2 ) used in the beam of the blade ( 1 ).
The lightning conduction system device, object of this invention, is applicable to already existing lightning conduction systems. This would merely imply including the new device by cutting the existing cable and connecting it between the carbon laminate ( 2 ) and the primary cable ( 6 ). The device ( 12 ) is an inductive element whose inductance varies between 5 mH and 50 mH based on the length of the blade (which could vary between 20 and 70 meters) and is preferentially formed by coil with two terminals for ease of connection. | A lightning rod system for wind turbine blades formed by various connections set up on carbon fiber laminates on the blade, equipotentializing the surface of the flanges of the beam through the deviations of a primary cable with the respective auxiliary cables, carried out with the use of a device having terminals that are connected between the ends of the cited auxiliary cable on the connection between the carbon laminates and the conductor cable or primary cable and which has elevated inductance so that it reduces the passage of current across the carbon laminate and favors the conduction through the metal cable. | 5 |
RELATED APPLICATIONS
This application is a National Stage application of International Application No. PCT/US2010/057049 filed Nov. 17, 2010, which claims the benefit of U.S. Provisional Application No. 61/261,963, filed Nov. 17, 2009, the entire contents of which are hereby incorporated herein by reference.
TECHNICAL FIELD
The present teachings relate generally to the preparation and use of emulsifiers.
BACKGROUND
Emulsifiers are used in the food industry (and non-food industries) to form oil-in-water emulsions for the dispersion of hydrophobic components, such as nutrients (e.g., omega-3 fatty acids), flavors, regular lipids, and the like. Emulsifiers govern emulsion stability—a key factor in food quality—thereby protecting against coalescence (e.g., aggregation and creaming) and oxidation (which leads to rancidity and hazardous compounds).
Among the different types of emulsifiers, biopolymer-based emulsifiers typically exhibit a stronger capacity for emulsion stabilization than small molecule-based surfactants, forming a thick interfacial layer that allows for more effective steric repelling among oil droplets. If the biopolymer is charged, static repelling is also stronger for biopolymer-based interfacial layers. In addition, the migrations of oxidative compounds (e.g., oxygen, metal ions, and radicals) are greatly reduced due to the thick layer.
Gum arabic and starch octenyl succinate (starch-OSA) are two biopolymer-based emulsifiers that have been used in prior efforts to increase emulsion stability.
SUMMARY
The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary.
By way of introduction, a dendritic emulsifier for forming an oil-in-water emulsion includes an anhydride-modified phytoglycogen or glycogen-type material.
A method of preparing an oil-in-water emulsion includes (a) combining oil, water, and a dendritic emulsifier; and (b) mixing a combination of the oil, water, and dendritic emulsifier. The dendritic emulsifier includes an anhydride-modified phytoglycogen or glycogen-type material.
A method of preparing a dendritic emulsifier includes reacting an anhydride with a phytoglycogen or glycogen-type material in solution, thereby forming an anhydride-modified phytoglycogen or glycogen-type material. The anhydride is selected from the group consisting of succinic anhydride, octenyl succinic anhydride, and a combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a transmission electron microscopy (TEM) image of a phytoglycogen (scale bar=100 nm).
FIG. 2 shows a representative chemical scheme for the reaction of phytoglycogen (PG-OH) with an anhydride reagent.
FIG. 3 shows an illustration of interfacial layers over oil droplets in various oil-in-water emulsions, wherein the layers are formed by small molecules (upper left), macromolecules (upper right), multilayer (bottom right), and dendritic molecules (bottom left).
FIGS. 4 a and 4 b show graphs of intensity vs. particle size distribution for oil-in-water emulsions at different stages.
DETAILED DESCRIPTION
Modified phytoglycogen and glycogen-type materials with a strong capacity for stabilizing emulsions have been discovered and are described hereinbelow. The amphiphilic dendritic molecule phytoglycogen octenyl succinate (PG-OSA) has shown superior performance in forming and stabilizing oil-in-water emulsions. It was further discovered that PG-OSA has a much greater ability to stabilize emulsions than either starch octenyl succinate (starch-OSA) or gum arabic (GA). Moreover, in view of the abundant availability of phytoglycogen—which is a major carbohydrate in commercial sweet com—PG-OSA has significant potential for industrial application. In addition, it is envisioned that large-scale production of glycogen can be readily achieved by industrial fermentation of yeast.
Throughout this description and in the appended claims, the following definitions are to be understood:
The term “dendritic” refers to a highly branched chemical structure.
The phrase “phytoglycogen or glycogen-type material” refers to dendritic (i.e., highly branched) α-D-glucan and carbohydrate nanoparticles. The term “phytoglycogen” generally refers to material that is derived from plants while the term “glycogen” generally refers to material that is derived from microbials and/or animals.
By way of introduction, phytoglycogen is a water-soluble glycogen-like α-D-glucan in plants. The largest source of phytoglycogen is the kernel of the maize mutant su1, a major genotype of sweet corn. The su1 mutation leads to a deficiency in SU1, an isoamylase-type starch debranching enzyme (DBE). In the biosynthesis of starch, starch synthase (SS), starch branching enzyme (SBE), and DBE work together to produce starch granules, with the primary role of DBE being to trim abnormal branches that inhibit the formation of starch crystals and granules. When there is a lack of DBE, the highly branched phytoglycogen is formed in the replacement of starch granules. FIG. 1 shows a TEM image of phytoglycogen nanoparticles with most particles ranging in size from 30 to 100 nm.
The highly branched structure of phytoglycogen results in its unusually high molecular density in dispersion. For example, in rice, the dispersed molecular density of phytoglycogen is over 10 times that of starch. Similarly, the molecular density of phytoglycogen from maize is around 1000 g/mol/nm 3 as compared to about 50 g/mol/nm 3 for amylopectin. The high density of phytoglycogen provides structural integrity and allows for dense grafting of functional groups.
Each phytoglycogen particle contains hundreds or thousands of glucan chains forming a highly packed structure. Without wishing to be bound by a particular theory or to in any way limit the scope of the appended claims or their equivalents, it is presently believed that that the spherical phytoglycogen particle grows from the non-reducing ends on the surface by periodic branching and elongation of chains. In phytoglycogen, there is no long chain that connects individual clusters as in the case of an amylopectin molecule, which suggests a fundamental structural difference between phytoglycogen and amylopectin.
FIG. 2 shows a representative synthetic scheme for modifying a phytoglycogen in accordance with the present teachings. Among food-grade starch-related reactions, succinylation and octenyl succinylation (both allowed by the U.S. Food and Drug Administration for food applications) have been used to introduce negative charge and/or hydrophobicity. The scheme shown in FIG. 2 can be readily modified to achieve both succinylation and octenyl succinylation: when R is hydrogen, the anhydride reagent is succinic anhydride; when R is —CH═CH—(CH 2 ) 5 —CH 3 , the anhydride reagent is octenyl succinic anhydride. The surface properties of a modified phytoglycogen can be controlled by the degree of substitution (DS).
In accordance with the present teachings, the amphiphilic dendritic molecule PG-OSA shows superior performance in forming and stabilizing oil-in-water emulsions. In oil-in-water emulsions, the nature of the amphiphilic interfacial layer governs physical stability to environmental stresses, chemical stability to oxidation, and the release pattern of encapsulated lipophilic compounds. Without wishing to be bound by a particular theory or to in any way limit the scope of the appended claims or their equivalents, it is presently believed that the advantages of biopolymer-based emulsifiers—such as waxy starch octenyl succinate (WX-OSA) and gum arabic (both of which are used in the industry)—involve their capability of forming a thick interfacial layer that maintains the physical stability of the emulsion through steric repelling among individual oil droplets.
Recently, multilayer constructs ( FIG. 3 , bottom right) have been developed using emulsifiers and biopolymers (laminated layers formed by electrostatic attraction) with an aim of tailoring the thickness and permeability of interfacial layers. However, the formation of stable multilayer emulsions requires careful control over system composition and preparation procedures in order to avoid droplet aggregation. Thus, at present, it is only possible to prepare dilute emulsions due to bridging flocculation.
The illustration at the bottom left of FIG. 3 depicts a nano-layer of PG-OSA dendritic molecules at an oil-in-water interface. Compared with small molecule emulsifiers ( FIG. 3 , upper left), the PG-OSA particles provide superior steric hindrance to droplet coalescence or aggregation. Moreover, as compared to regular amphiphilic macromolecules (e.g., WX-OSA or GA), the interfacial layer formed by dendritic particles is denser and structurally more defined. Finally, as compared to a multilayer interfacial structure ( FIG. 3 , bottom right), the interfacial layer formed by dendritic particles avoids the problem of bridging flocculation due to the simplicity of formation of the nano-layer. In addition, the interfacial layer formed by dendritic particles has the added benefit of having a high layer density (and, therefore, a low permeability to oxidative compounds).
The following examples and representative procedures illustrate features in accordance with the present teachings, and are provided solely by way of illustration. They are not intended to limit the scope of the appended claims or their equivalents.
Materials and Methods
Phytoglycogen is extracted from the matured kernels of an su1-containing sweet corn cultivar, Silver Queen. To isolate native phytoglycogen, the kernels of sweet corn are ground, soaked in deionized water, and homogenized. The non-soluble materials (e.g., fiber, starch, protein, oil) are removed using repetitive filtration and centrifugation. Phytoglycogen is precipitated from the supernatant by adding 3 volumes of alcohol, which can effectively remove small, soluble molecules. The precipitate is collected by filtration and dehydrated using anhydrous alcohol and acetone. The phytoglycogen thus obtained is rather pure with a low soluble protein content. The yield of phytoglycogen ranges from 20 to 25% of dry kernels.
For the modification of phytoglycogen, a solution of phytoglycogen derivative (5% w/w) is adjusted to pH 8.5 followed by the addition of octenyl succinic anhydride (OSA) at 25 ° C. During the reaction, pH is maintained between 8.5 and 9.0. To conclude the reaction, the solution is adjusted to pH 6.5 followed by the addition of 3 volumes of ethanol. The precipitate undergoes repetitive dispersion-centrifugation washing using 80% ethanol, and is then dehydrated by anhydrous ethanol and acetone. The degree of substitution (DS), which is the molar ratio between substitution groups and glucosyl units, is determined by the titration of carboxyl group of octenyl succinate (JECFA method CXAS/1991). Briefly, PG-OSA is fully acidified using 2.5 N HCl and then treated by repetitive dispersion-centrifugation washing using 90% isopropanol to remove free HCl. A solution of AgNO 3 (0.1 N) is used to test for the presence of chloride to ensure a complete removal of HCl. After the complete removal of HCl, a solution of 0.01 N NaOH is used to determine the amount of H + (which is equal to the molar amount of grafted octenyl succinate groups). Typically, the efficiency of substitution (i.e., the molar yield of grafted groups) ranges from 30 to 70%. By controlling the amount of added OSA, the DS value distributes in the range of 0.002 to 0.20.
To prepare an emulsion (e.g., for fish oil), fish oil 5% and PG-OSA 10% (w/w based on water) are mixed with deionized water, treated with a high-speed mixer (IKA T25) at 20,000 rpm for 2 minutes, and homogenized at room temperature using a high pressure homogenizer (Nano DeBee, Bee International) at 25,000 psi. To track the susceptibility of the emulsion to coalescence during storage, immediately after homogenization and after 4 weeks at 4 ° C. storage, the emulsion is diluted by 125 times and the particle size distribution is measured using a Zetasizer Nano ZS-90 (Malvern). To evaluate lipid oxidation at different storage times, the ability of peroxides (produced by lipid oxidation) to oxidize ferrous ions to ferric ions was measured. Briefly, an aliquot of emulsion is added to isooctane-2-propanol, followed by lipid extraction using vortex and centrifugation. The lipid extraction is added with a mixture of methanol and butanol, ammonium thiocyanate, and ferrous iron acid solution. After incubation, the absorbance is measured at 510 nm against standard ferric ions curve and used to denote the extent of lipid oxidation.
FIGS. 4 a and 4 b show plots of intensity vs. size for the formation and stability of fish oil emulsions emulsified by phytoglycogen octenyl succinate (PG-6 and PG-9), waxy corn starch octenyl succinate (WX-6 and WX-9), and gum arabic (GA). In accordance with the present teachings, it was discovered that PG-OSA offers a greater capability to stabilize oil-in-water emulsions than either WX-OSA or GA. Thus, the particle size of oil droplets over a 4-week storage period is more stable with PG-OSA than with either WX-OSA or GA.
The degree of octenyl succinylation is comparable between PG-6 and WX-6 (0.023 and 0.026 respectively) ( FIG. 4 a ) and between PG-9 and WX-9 (0.050 and 0.043 respectively) ( FIG. 4 b ). The particle size distribution was measured immediately after homogenization (0 week) and after the 4-week storage at 4° C. Evidently, the droplet particle size of a PG-6 or PG-9 emulsion is much more stable than that of WX-6 or WX-9. Both PG-OSA and WX-OSA performed substantially better than GA in forming emulsion.
Table 1 shows data for the relative levels of peroxide produced due to oxidation of the fish oil after storage for around 10 weeks. Evidently, the oxidation of fish oil in emulsion was much lower for PG-6 and PG-9 than for WX-6, WX-9, and gum arabic.
TABLE 1
Relative level of peroxide produced using PG-OSA, WX-OSA, and GA
Emulsifier
PG-6
PG-9
WX-6
WX-9
Gum Arabic
Relative level of
0.448
0.533
0.894
0.936
0.935
peroxide
The following literature provides information that may be useful in accordance with the present teachings and each document is hereby incorporated by reference in its entirety, except that in the event of any inconsistent disclosure or definition from the present specification, the disclosure or definition herein shall be deemed to prevail: (1) Guzey, D., McClements, D. J. “Impact of electrostatic interactions on formation and stability of emulsions containing oil droplets coated by beta-lactoglobulin-pectin complexes,” Journal of Agricultural and Food Chemistry, 2007, 55, 475-485; (2) James, M. G., Robertson, D. S., Myers, A. M., “Characterization of the maize gene sugary1, a determinant of starch composition in kernels,” Plant Cell, 1995, 7, 417-429; (3) Klinkesorn, U., Sophanodora, P., Chinachoti, P., Decker, E. A., McClements, D. J. “Encapsulation of emulsified tuna oil in two-layered interfacial membranes prepared using electrostatic layer-by-layer deposition,” Food Hydrocolloids, 2005, 19, 1044-1053; (4) McClements, D. J., Decker, E. A., Weiss, J. “Emulsion-based delivery systems for lipophilic bioactive components,” Journal of Food Science, 2007, 72, R109-R124; (5) Myers, A. M., Morell, M. K., James, M. G., Ball, S. G. “Recent progress toward understanding the amylopectin crystal,” Plant Physiology, 2000, 122, 989-997; (6) Nakamura, Y. “Towards a better understanding of the metabolic system for amylopectin biosynthesis in plants: Rice endosperm as a model tissue,” Plant and Cell Physiology, 2002, 43, 718-725; (7) Ogawa, S., Decker, E. A., McClements, D. J. “Influence of environmental conditions on the stability of oil in water emulsions containing droplets stabilized by lecithin-chitosan membranes,” Journal of Agricultural and Food Chemistry, 2003, 51, 5522-5527; (8) Shantha, N. C., Decker, E. A. “Rapid, sensitive, iron-based spectrophotometric methods for determination of peroxide values of food lipids,” Journal of AOAC International, 1994, 77, 421-424; (9) Shin, J., Simsek, S., Reuhs, B., Yao, Y. “Glucose release of water-soluble starch-related a-glucans by pancreatin and amyloglucosidase is affected by the abundance of a-1,6 glucosidic linkages,” Journal of Agricultural and Food Chemistry, 2008, 56, 10879-10886; (10) Thompson, D. B. “On the non-random nature of amylopectin branching,” Carbohydrate Polymer, 2000, 43, 223-239; (11) Wong, K., Kubo, A., Jane, J., Harada, K., Satoh, H., Nakamura, Y. “Structures and properties of amylopectin and phytoglycogen in the endosperm of sugary-1 mutants of rice,” Journal of Cereal Science, 2003, 37, 139-149; (12) Wurzburg, O. B. “Modified Starch,” in Food Polysaccharides and Their Applications, Second Edition , edited by Stephen, A. M., Phillips, G. O., and Williams, P. A., CRC, 2006; and (13) Yao, Y. “Biosynthesis of starch,” in Comprehensive Glycoscience , edited by Hans Kamerling, Elsevier, 2007.
The foregoing detailed description and accompanying drawings have been provided by way of explanation and illustration, and are not intended to limit the scope of the appended claims. Many variations in the presently teachings will be apparent to one of ordinary skill in the art, and remain within the scope of the appended claims and their equivalents. | A dendritic emulsifier for forming an oil-in-water emulsion includes an anhydride-modified phytoglycogen or glycogen-type material. A method of preparing an oil-in-water emulsion includes: (a) combining oil, water, and a dendritic emulsifier; and (b) mixing a combination of the oil, water, and dendritic emulsifier. A method of preparing a dendritic emulsifier includes reacting an anhydride with a phytoglycogen or glycogen-type material in solution, thereby forming an anhydride-modified phytoglycogen or glycogen-type material. | 0 |
This application is a continuation of U.S. patent application Ser. No. 163,884, filed on June 27, 1980 which is now U.S. Pat. No. 4,513,107.
BACKGROUND OF THE INVENTION
This invention relates to thermally-transferable ink compositions, and processes for transferring a dry layer of a thermally-transferable ink composition from a carrier to a receptor. The present invention is particularly useful in manufacturing sign faces by transferring indicia from a carrier to a receptor in a completely dry process.
Past techniques for manufacturing sign faces have not proven entirely satisfactory. For example, these techniques have involved masking or outlining the surface of the sign face so as to provide a desired outline, followed by painting (e.g., by brushing or spraying) to obtain the desired colored design. Such techniques are time consuming, messy, and require that steps be taken to provide adequate ventilation for the hazardous solvents employed with the paints or inks. Moreover, steps must be taken to insure that the solvents used in the inks do not destroy the surface to which they are applied. Furthermore, such prior art techniques frequently require that various inks be mixed. This of course means that a color match must be made before the mixed ink can be utilized.
Processes for thermally transferring indicia from a carrier (e.g., release liner) to a receptor (e.g., a fabric such as cotton) and composition useful therewith are also known. See for example U.S. Pat. Nos. 3,361,281; 3,519,463; 3,684,545; 3,928,710; and 4,037,008. These processes and compositions generally require the use of high heat and pressure to effect transfer. Typically temperatures of 120° C. or more are required.
The use of the foregoing processes has not proven entirely satisfactory. For example, the temperatures employed require the use of large quantities of energy and limit the number of materials that can be utilized as receptors as the heat generated may degrade certain polymeric receptors. Still further, these prior art processes have not been found to provide strongly adhered images on uneven or textured and three dimensional substrates. Consequently, it is clear that a need exists for compositions, and processes for transferring thermally-transferable inks that overcome these disadvantages.
SUMMARY OF THE INVENTION
Provided herein are a novel process and composition that provides unique results. The process comprises a dry technique for transferring a thermally-transferable ink composition from a carrier to a receptor. This process eliminates the need to employ adhesives to bond the ink to the receptor. It also eliminates the need to go through the time consuming and potentially hazardous techniques described above. Furthermore, it eliminates the need for the sign fabricator to employ volatile solvents in sign preparation. Still further, the process provides the sign fabricator with almost unlimited versatility in the design of the artwork to be utilized on the sign face. Consequently, the fabricator can employ a wide variety of colors and decorative designs on the sign face.
The process of the invention comprises the steps of
(a) providing a carrier bearing a thermally-transferable ink composition;
(b) applying said ink to a receptor surface;
(c) adjusting said receptor surface so that it is free from wrinkles;
(d) evacuating substantially all of the air from the interface between said ink and said receptor surface;
(e) heating said ink and said receptor surface to a temperature, and for a time, sufficient to soften said ink and intimately bond it to said receptor, said heating occurring after substantially all of said air has been evacuated from said interface.
The novel composition provided herein is particularly preferred for use with the above-described process. It comprises a thermally-transferable ink composition having a 20% elongation temperature of less than 85° C. and an elongation at break of at least about 15%. The ink is made up of
(a) from about 36 to 95% by weight of a thermoplastic polymer selected from the group consisting of polyvinyl chloride and copolymers thereof;
(b) from about 50 to 5% by weight of a flexibilizer for said thermoplastic polymer that is compatible with said thermoplastic polymer; and
(c) up to about 40% by weight of a colorant.
Sign faces made by utilizing the novel process and composition described herein offer several advantages. For example, the ink compositions conform virtually exactly to the surface of the receptor. Thus, the ink can be applied to textured substrates and be totally adhered thereto.
Still further the inks of the invention can be utilized to fill-in openings left for indicium in a previously applied layer. The ink conforms exactly to the surface and completely fills in the opening and becomes totally adhered to the receptor. This is particularly useful in providing indicia of one color on a differently colored background.
The conformability of the inks of the invention is of particular significance in the preparation of large are flexible sign faces. These sign faces typically require that two or more sheets of the receptor be joined or seamed together. Each juncture or seam is thicker than an individual sheet of the receptor so that a mound or ridge is formed. The inks of the invention conform and adhere to both the seam and the balance of the receptor tenaciously.
This excellent adhesion and conformability is surprising, particularly with respect to the most preferred aspects of the invention, since low transfer temperatures are employed during the process. Furthermore, ink transferred in accordance with the present invention exhibit excellent flexural characteristics. Thus, when a completed pliant sign face is flexed, the ink does not crack or peel off. Moreover, when completed rigid sign faces expand and contract due to temperature changes, the ink does not crack or peel off.
Still further, the ink compositions of the invention exhibit excellent weatherability. For example, they do not show any significant fading or darkening when exposed to outdoor conditions. Moreover, they do not chip, peel, crack, etc. under these conditions.
The adhesion of the transferred ink to the receptor is demonstrated by the tape adhesion test described in ASTM D 3359-74, method B with the modification that the receptor is 0.5 mm thick.
In the tape adhesion test, a lattice cut is made so as to provide intersecting cut lines through the ink layer and into the receptor. Pressure sensitive tape is applied over the lattice and then stripped away. The ink compositions of the invention exhibit a classification number of at least 4, and preferably 5. A classification number of 4 means that virtually none of the transferred ink is removed while a classification number of 5 means that none of the transferred ink is removed.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the present invention, a thermally-transferable ink is transferred from a carrier to a receptor at a temperature sufficient to soften the ink and intimately bond it to the receptor. While any temperature sufficient to achieve this result may be utilized, the temperature is preferably in the range of 75° C.-110° C., and most preferably in the range of 85° C.-95° C.
The essential steps of the process of the invention are set forth above. Thus, a carrier bearing a dry layer of thermally-transferable ink (hereinafter referred to as the "transfer sheet") is placed on a desired receptor so that the ink contacts the receptor surface. Carriers and techniques for applying the ink thereto will be described hereinafter.
While it is not necessary to the process, it is frequently desirable to provide an image of the desired art work on the receptor prior to placing the transfer sheet on the receptor. A variety of techniques may be employed to do this. In one useful technique a reduced-size black and white photocopy of the sign face to be prepared is made. The photocopy is then utilized to make a projection transparency, which is then projected onto the desired receptor surface. The size of projected image can be readily adjusted so as to obtain the desired size of sign by techniques known to the art.
The transfer sheet may be fastened to the receptor by a variety of techniques. However, simply taping the transfer sheet is sufficient. If, it is desired to provide a differently colored background, that is a color that is different than the color of the receptor, a transfer sheet of one color may be fastened to the portion of the receptor surface desired to be differently colored followed by removing (e.g., by cutting out) the image areas from the transfer sheet. A second transfer sheet, having the color desired for the art work may then be fastened over the cut-out areas of the first transfer sheet.
Once the appropriately colored transfer sheets have been fastened to the receptor, the resulting intermediate structure is placed in a device, such as a vacuum frame, and adjusted so as to provide a wrinkle free surface. If necessary, this may be accomplished by placing the intermediate structure under tension.
A particuarly advantageous technique for providing a wrinkle-free surface is to turn on the vacuum pump of the vacuum frame with the intermediate on the vacuum bed thereof and with the top thereof up. If the intermediate does not cover the entire vacuum bed, sheets of substantially non-porous material may be placed over the uncovered portions. Wrinkles in the intermediate may then be squeezed out or otherwise removed. The non-porous sheets may then be removed (leaving the wrinkle-free intermediate) and the top lowered.
Typically the intermediate is placed in the vacuum frame so that the receptor contacts the vacuum bed and the transfer sheeting contacts the top when the top is closed. The exact vacuum frame utilized in the process of the invention is not critical to the invention as a variety of commercially available vacuum frames are useful.
Preferably the vacuum bed of the frame has a smooth surface free from ridges, lumps, etc., especially where the perforated vacuum bed meets the outer supports of the vacuum frame. Additionally, the vacuum bed is preferably covered with a porous material such as muslin.
The top of the vacuum frame contains an air bladder and, above the bladder, a lamp bank. The top is preferably hinged on one end and has locks on the other end. The hinges and locks are located so that a wide sheet of receptor can pass therebetween. A porous fabric, such as muslin, is preferably fastened to the surface of the bladder that contacts the transfer sheet. The lamp bank preferably comprises a plurality of lamps that, preferably, emit radiation in the infra red range. A temperature controller is also preferably included so as to regulate the heat input into the vacuum frame.
Once the wrinkles have been removed from the intermediate, the vacuum frame is closed and a vacuum created therein to evacuate substantially all of the air from the interface between the ink and the receptor and provide intimate contact between the receptor and the ink. It has been found that this may be accomplished by reducing the pressure in the frame to between about 0.1 to 0.25 atmosphere for from 2 to 5 minutes. Preferably the pressure is reduced to at least about 0.2 atmosphere.
The receptor surface and the ink are then heated to the predetermined transfer temperature. Heating may be accomplished by a variety of techniques, although it has been found that a bank of 300 watt incandescent light bulbs that emit radiation in the infrared range is satisfactory. The intermediate, particularly receptor surface and ink, is heated to a temperature sufficient to soften the ink and intimately bond it to the receptor. The exact temperature is dependant upon the nature of the ink and the receptor employed. The temperature must, however, be below that at which the ink and receptor degrade.
During heating, the ink and receptor surface fuse together and form an intimate bond. Preferably heating is carried on only for a time sufficient to accomplish this result. It has been found that, with the compositions of the invention, heating need only be at a temperature between about 75° to 110° C. for from 2 to 10 minutes.
Evacuating substantially all of the air from the interface between the receptor surface and the ink causes a pressure differential between the interface and the exterior of the intermediate structure. The lack of air at the interface in combination with the pressure differential makes it possible to achieve the tenacious and intimate bonding of the ink to the receptor at low temperatures. Preferably the pressure differential is at least about 0.75 atmosphere.
The vacuum is then released and the receptor and ink are cooled. This may be done by passive means or by active means, for example by blowing air over the intermediate. Once the intermediate has cooled to a temperature (e.g., a temperature of 65° C. or less) sufficient to harden the ink and cause the adhesion of the ink to the receptor to be greater than the adhesion of the ink to the carrier, the carrier is stripped from the receptor. The resultant receptor then bears indicia that are firmly anchored thereto and that conform exactly to the surface thereof.
In the event that the receptor is too large to fit entirely within the vacuum frame at one time, the above described process may be repeated in a step-wise manner until the entire sign face has been completed. During a step-wise process it is preferred that indicia (e.g., letters, numbers, etc.) to be transferred be located entirely within the frame during heating.
A wide variety of receptors may be utilized in the process of the invention. They may be polymeric or non-polymeric, flexible or rigid, and thick or thin. Moreover, the surface of the receptor may be smooth or irregular.
Receptors useful with the present invention include a variety of polymeric films including polyvinyl-chloride (e.g., Panaflex® film from National Advertising Company and Scotchal® film from 3M Company), acrylic films (e.g., Plexiglass® from Rohm and Haas), cellulose acetate butyrate film, and urethane films. Other resin films may also be employed as receptor materials. The receptor materials may be used as such or they may have their surface modified by, for example, priming, corona treatment, solvent wiping, etc.
The novel compositions described herein comprise a defined thermoplastic resin, a flexibilizer for said resin, and, optionally, a colorant, an ultraviolet light absorber, a heat stabilizer, a surfactant, a flow aid, etc. They have a 20% elongation temperature of no more than about 85° C. and preferably one in the range of 70° C. to 85° C. Additionally, they have an elongation at break of at least 15%.
The 20% elongation temperature is determined in the same manner as the ring and ball softening point described in ASTM E-2842-T except that the film thickness is 25 microns, the ball weight is 1.5 g, the ring width is 14 cm, and heating is done in air and commences at 60° C. and is raised at a uniform rate of 1.7° C. per minute. The 20% elongation temperature is that temperature at which a film of the resin has elongated 120% of its original dimension.
Elongation at break is measured according to ASTM D412-75, Method A, section 12.2. Test samples are 1.25 cm wide with a spacing of 1.25 cm. Pulling speed is 10 cm per minute. The measurement of elongation at break is set forth at section 5.2 of the test method.
The ink compositions may be readily prepared by, for example, dissolving the thermoplastic resin and flexibilizer together in a suitable screen-printing solvent, such as isophorone or cyclohexanone, followed by addition of the colorant and other ingredients. The colorant may be added directly if a dye is used. If a pigment is used, it is first preferably dispersed in a solvent, resin, or plasticizer that is compatible with the solvent used to dissolve the thermoplastic resin. Known processing techniques may be employed in preparing the compositions.
The thermoplastic resins useful in the novel compositions comprise from about 50% to 95% by dry weight of the composition, and preferably from about 65% to 95% by dry weight. They are selected from polyvinyl chloride and copolymers thereof. Specific examples include, for example, polyvinyl chloride, polyvinyl chloride-polyvinyl acetate copolymers (e.g., Bakelite® VYHH available from Union Carbide Company).
The flexibilizer employed in the novel compositions comprises from about 50 to 5% by dry weight of the composition, and preferably from about 20 to 5%. It flexibilizes the composition and is compatible with the vinyl polymer or copolymer. Moreover, it imparts conformability and elasticity to the ink composition, and improves its film strength by improving the elongation characteristics of films of the ink.
Representative classes of useful flexibilizers are selected from the group consisting of synthetic resins that are free from vinyl chloride units and that have a 20% elongation temperature of less than about 85° C., and plasticizers for polyvinyl chloride.
Specific examples of useful vinyl chloride-free resins include ethyl, methyl, and butyl methacrylate homopolymers, and copolymers of said homopolymers with methyl, ethyl, and butyl acrylate. Such resins are available from Rohm and Haas as the Acryloid® series and from DuPont as the Lucite® series.
Other useful vinyl-chloride-free resins are urethane polymers such as polyester-functional aromatic urethanes (e.g., the Estane® series from B. F. Goodrich), and polyester and polyether-functional aliphatic urethanes (e.g., respectively QI-12 and PE-192 from Quin).
Other useful thermoplastic resins include linear polyester resins (e.g., Vitel® PE-222 from Goodyear), acrylonitrile-butadiene-styrene resins (e.g., Cycolac® WA 2021 from Borg-Warner), polycaprolactam polymers (e.g., PCL-700 Union Carbide, sucrose acetate isobutyrate, available as SAIB from Eastman Chemical, ethylene vinyl acetate resin, ethyl methacrylate, and butyl methacrylate resin. Combinations of vinyl chloride-free thermoplastic resins may be utilized if desired.
Specific examples of classes of plasticizers useful in the compositions of the invention are alcohol phthalates (e.g., Santicizer® 711, a mixture of alcohol phthalates containing from 7 to 11 carbons in the phthalate chain from Monsanto); polymeric polyesters (e.g., Santicizer® 429, available from Monsanto); aromatic phthalates (e.g., Santicizer® 160, butyl benzyl phthalate from Monsanto) and mixed lower alkyl benzyl phthalates (Santicizer® 261 from Monsanto); epoxidized vegetable oils (e.g., epoxidized linseed oil, epoxidized soybean oil, epoxidized safflower oil); and phosphoric acid derivatives (e.g., Santicizer® 141, 2-ethylhexyl-diphenyl phosphate from Monsanto), and tricresyl phosphate from Monsanto.
Blends of flexibilizers e.g., combinations of one or more resins with one or more plasticizers, may be employed if desired.
Colorants useful in the compositions of the invention comprise up to about 40% by dry weight of the composition. Preferably they comprise from about 1% to 30%. Quantities of from about 1% to 15% are useful in providing light and pastel shades while quantities of from about 15% to 30% are useful in providing dark colors. The colorants may be selected from dyes or pigments, although pigments are preferred.
______________________________________Molybdate Orange Primrose YellowQuinacridone Red Phthalocyanine BlueCarbon Black Phthalocyanine GreenRutile Titanium Dioxide Carbazole VioletChrome Yellow Irgasine YellowLead Chromate Yellow Quinacridone Pink______________________________________
The pigments may be provided in dry bulk form, or as a dispersion in a solvent, liquid or solid resin, plasticizer, or combinations thereof.
A variety of other ingredients may be utilized in the compositions of the invention. Thus, for example, ultraviolet light absorbers, heat stabilizers, surfactants to aid application of the composition to a carrier, and solvents may be employed. Examples of materials useful for these purposes are known as will be understood as a result of this disclosure.
As discussed above, the compositions useful in the present invention are prepared by dissolving the ingredients together in an appropriate solvent. The solution is then filtered and coated onto a suitable carrier. Coating is preferably carried out by screen printing. Other coating techniques, such as reverse roll, knife, and rotogravure, may be utilized if desired. The solvent is removed from the coated layer by, for example, impinging the coating with air at about 80° C.
The thickness of the dry layer of thermally-transferable ink is not critical to the invention. However, it has been found that good results, in terms of transferred indicia quality, may be obtained if the layer has a thickness in the range of 5 to 50 microns. Preferably the thickness is in the range of 8 to 25 microns. Most preferably the thickness is about 25 microns.
The carrier utilized in the transfer sheet may be any material that is dimensionally stable and exhibits high release characteristics. Thus, the carrier must release from the thermally-transferable ink once it has been adhered to a receptor. The carrier usually is coated or impregnated with a suitable release material so as to facilitate this release. The carrier preferably is flexible and exhibits good hand, that is, it may be cut easily by die cutting or hand cutting techniques.
Sheeting materials that have suitable release characteristics are known. They include Warren O-Duplex, available from S. D. Warren Paper Co.; Trans-Eze® 2000 and 3000, and Kimdura, all available from Kimberly-Clark; polyethylene sheeting, and polypropylene sheeting. Silicone or other treated paper may also be employed.
The thermally-transferable ink may occur on the carrier in a variety of ways, including, for example, as a continuous layer of the ink or as one or more discrete indicium. The former type of transfer sheet may be used to provide large background areas or individually prepared indicium on sign faces. The latter type of transfer sheet may be used in applying pre-prepared indicium to a receptor.
In the process of transferring thermally-transferable ink, especially to form sign faces, described herein it is preferable, though not necessary, to apply a clear (i.e., colorless and transparent) layer over the indicium-bearing surface. The clear layer is most preferably thin (i.e., approximately 25 microns) and clear layer acts as a barrier to the loss of flexibilizer (especially plasticizer). Additionally, it reduces the ability of nutrients to come to the surface thereby reducing the growth of fungus. Still further, it serves as a moisture barrier. Furthermore, it can contain other additives such as ultraviolet light absorbers, antioxidants, fungistats, and so forth.
The clear coat may be applied by the same techniques used to transfer the ink from the carrier to the receptor. Like the ink, the clear coat is preferably provided on a material that exhibits high release characteristics. Common processing techniques can be utilized to apply the clear coat to a release material.
A useful clear coat comprises at least 95% by weight of acrylic polymers such as polymethyl methacrylate, and copolymers of methyl methacrylate with ethyl and butyl methacrylate. The remaining 5% by weight is made up of other additives such as those mentioned above. Examples of these materials include the 3900 and 4000 series of Scotchcal® resins available from 3M Company.
Known thermoplastic compositions may also be employed to provide the thermally-transferable ink in the process of the present invention. However, these materials must be combined with a flexibilizer if they are to have a combination of a 20% elongation temperature less than about 85° C. and an elongation at break of at least 15%. Examples of such commercially available formulations include the 600 Series inks from General Formulations (a division of General Research Incorporated), the G.V. series inks from Naz Dar, the 9600 series inks from Colonial Inks, the "Lov" series from Advance Screen Printing Co., and the 8000 series vinyls from Tibbetts & Westerfield.
The present invention is further described in the following examples wherein all percentages are by weight unless otherwise indicated.
EXAMPLE 1
Thermally transferable ink formulations were prepared from the following ingredients using the quantities indicated.
______________________________________ %______________________________________Polyvinyl Chloride-Polyvinyl Acetate Copolymer 18(Bakelite ® VYHH from Union Carbide,86% vinyl chloride and 14% vinyl acetate)Polymethyl Methacrylate-Ethyl Methacrylate 4Copolymer (Acryloid ® B82 from Rohm and Haas)Aliphatic Urethane (QI 12 from K. J. Quin)* 4Butyl Benzyl Phthalate (Santicizer ® 160 7from Monsanto)Mixed Alkyl Benzyl Phthalate (Santicizer ® 261 7from Monsanto)Quinacridone Red 102,2-dihydroxy-4,4-dimethoxy benzophenone 0.1Ba & Cd Stearate 0.25Epoxidized Linseed Oil 0.5Isophorone 25.1Butyl Cellosolve 7.75Mixed aromatic solvents (SC solvent 150 from 5.1Central Solvents and Chemicals)Diacetone Alcohol 7.1Cyclohexanone 4.1______________________________________ *Provided in solution, solvent evaporated and dry urethane added.
The ink solution was prepared by mixing all ingredients together until they had dissolved and the pigment has dispersed. The pigment was provided in a dispersion in cyclohexanone before addition.
The solution was then applied to the release surface of a carrier of Trans-Eze® 2000 and dried at 60° C. to remove the solvent. The thickness of the dried layer was 25 microns. The ink composition has a 20% elongation temperature of 82° C. and an elongation at break of 110%.
The resulting dry transfer sheet was applied to the surface of a polyvinyl chloride sheet that was reinforced with thermoplastic fibers so that the thermally-transferable ink contacted the polyvinyl chloride sheet. The surface of the polyvinyl chloride sheet was three-dimensional. The resulting intermediate structure was placed in a vacuum frame and adjusted to remove all wrinkles. The frame was then closed and the pressure therein reduced to 0.2 atmosphere after which the temperature therein was raised to 88° C. This pressure and temperature were maintained for 2 minutes. The pressure was then increased to atmospheric pressure and the temperature in the vacuum frame was lowered to 50° C. The carrier was then stripped from the receptor. The ink transferred completely from the carrier to the receptor. The carrier left no residue on the indicia. When the tape adhesion test was performed on the transferred ink, a classification number of 5 was obtained (i.e., no ink was removed from the receptor).
EXAMPLES 2-5
Thermally-transferable ink formulations were prepared and coated onto Trans-Eze® 2000 carrier as described in Example 1 from the following formulations. All quantities are in %.
______________________________________ 2 3 4 5______________________________________Bakelite ® VYHH 18 18 25 25Acryloid ® B82 4 4 -- --Sucrose Acetate Isobutyrate 4 4 -- --Santicizer ® 711 (mixture of 7 7 -- 6.25alcohol phthalates fromMonsanto)Santicizer ® 261 (Aromatic 7 7 -- --Phthalate Plasticizer fromMonsanto)Phthalocyanine Blue 8 -- -- --Rutile Titanium Dioxide 0.5 -- -- --Carbazole Violet 1.5 -- -- --Quinacridone Red -- 8 -- --Molybdate Orange -- 2 -- --2,2-dihydroxy-4,4-dimethoxy- 0.4 0.4 -- --benzophenoneBa & Cd Stearate 0.5 0.5 -- --Epoxidized Soy Bean Oil 1 1 -- --Dimethoxy Silicone (SF-96 0.1 0.1 -- --from General Electric)Isophorone 30 30 -- --Butyl Cellosolve 8 8 -- --Mixed aromatic solvents (SC 10 10 -- --solvent from CentralSolvents and Chemicals)Cyclohexanone -- -- 75 68.75______________________________________
The ink compositions had respective 20% elongation temperatures of 71° C., 71° C., 85° C., and 84° C., and elongations at break of 130%, 130%, 0%, and 95%.
The ink compositions of the resulting transfer sheets were transferred to a Panaflex® receptor as described in Example 1 at various temperatures. The pressure was 0.2 atmosphere. It was found that a temperature of only 82° C. was sufficient to transfer the ink composition of Example 2. A classification number of 5 was obtained in the tape adhesion test. The ink compositions of Examples 3-5 demonstrated the same classification number when transferred at a temperature of about 88° C.
When the composition of Example 4 was transferred as described above to a seam, it was found that the tape adhesion classification number was less than 4 for that portion of the ink on the seam. This demonstrates that while many ink compositions may be transferred according to the process of the invention, those of the invention provide superior results. | A process and composition are provided that provide for thermal transfer of ink compositions and eliminate the need to prepare articles such as sign faces, particularly flexible sign faces, by painting with ink compositions that contain solvents. The present process and composition permit thermal transfer from a carrier to a receptor at low temperatures with the use of vacuum pressure. The transferred ink adheres tenaciously to the receptor and is flexible. | 3 |
The present invention relates to film laminates which are particularly impermeable for gas, and to the use of these gas impermeable film laminates as wrapping material of vacuum insulation panels.
BACKGROUND OF THE INVENTION
In some special technical products, such as e.g. in the production of vacuum insulation panels (VIPs), films are needed which possess extremely low gas permeability values to guarantee that the vacuum, once applied, and thus the serviceability of the VIPs, is maintained over a very long period (10-15 years).
Conventional barrier films made of plastics, as described e.g. in EP-A 0 517 026, do not achieve the gas barrier effect needed. Composites containing an aluminium foil, while they do possess a total gas barrier, are undesirable in many applications because of the thermal conductivity of aluminium.
In addition, metallised films or films vapour-coated with SiOx are known which avoid the disadvantages relating to the thermal conductivity of the pure metal foils (as described e.g. in EP-A 0 878 298), and achieve higher barrier effects than pure plastic films, but their values are also a long way from the gas barrier values required.
Vacuum insulation panels (VIPs) here mean sheet-like objects which consist of an insulating material and/or filler and are wrapped in a high-barrier film by vacuum packing. The type, and particularly the level, of the vacuum here are dependent on the insulating material or filler used and on the insulating action required of the VIP. Over the service life of the VIP, the wrapping with a high barrier film prevents the diffusion of gases, which impair the vacuum and thus the insulating properties of the VIP. Metal foils are undesirable as the high-barrier films, since these conduct heat over the edges of the sheet-like VIP and thus reduce the insulation performance.
The object of the present invention was therefore to provide film laminates which achieve a particularly high gas barrier effect without using thermally conductive metal foils as components. At the same time, mechanical and thermal properties of the film laminate should be improved. In particular, film laminates suitable for the production of vacuum insulation panels (VIPs) should be provided.
SUMMARY OF THE INVENTION
According to the invention, this is achieved by providing of a multi-layer film laminate comprising at least 4 layers (I) to (IV), arranged directly or indirectly in the following sequence:
layer (I) as one surface layer of the film laminate comprising at least one layer vapour-coated with aluminum or SiOx or a metal oxide from the main groups 2 or 3, whereby the vapour-coated surface is adjacent to the following layer,
layer (II) as a gas barrier layer of resin,
layer (III) comprising at least one further layer vapour-coated with aluminum or SiOx or a metal oxide from the main group 2 or 3 and
layer (IV) as a heat-sealable layer, which is the other surface layer of the film laminate.
It would be expected for the gas barrier effect of the film laminate according to the invention to be provided by the gas barrier effect of the individual film with the lowest permeability, or to be calculated from the sum of the barrier effects of the individual films, but surprisingly, gas barrier effects are achieved which are not only distinctly higher than those of the individual films but are even higher than those of the sum of the individual films.
In order to obtain even further increased gas permeability values the film laminates according to the invention can contain the layer (I) and/or the layer (III) preferably more than one time, and this layer or these layers can be vapour-coated or not vapour-coated with aluminium or SiOx, with x for 1-2, preferable 1.5-1.8, or a metal oxide from main groups 2 or 3 and the vapour-coated surfaces of the layers (I) and/or (III) are preferable adjacent to each other.
DETAILED DESCRIPTION
The layers vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3 can consist of any conventional thermoplastic resins, particularly of resins of at least one polyester, polyamide, polyolefin or a copolymer thereof. These layers (I) and/or (III) can also consist of a coextrudate of different polymers, which consists of at least one layer, particularly two layers of one of the above mentioned thermoplastic resins, and a gas barrier layer of resin, particularly of a hydrolysed ethylene vinyl acetate (EVOH) with 25-45 Mol-% vinyl acetate and is sandwiched particularly between two layers of the mentioned thermoplastic resins. The thickness of the individual layers (I) and/or (III) and the each entire thickness is not essential, but can influence the gas barrier effect to a small degree and will help to determine the mechanical and thermal properties of the film laminate.
With the film laminates according to the invention oxygen permeability values of less than 0.1 cm 3 /m 2 d bar (23° C., 75% r.h.), in particularly of less than 0.05 and in particularly of ≦0.01 and water vapour permeability values of ≦0.1 g/m 2 d (38° C., 90% r.h.) can be achieved. The oxygen permeability is determined according to DIN 53380-3 and the water vapour permeability according to DIN 53122. Through the combination of different layers, not only can the gas permeability values be adjusted to the values required by the application, but it is also possible, by modifying the material of the layer vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3, to vary the mechanical and/or thermal reference values of the resulting film laminate according to the invention.
If a polyamide vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3 is arranged as the surface layer (I), the resulting film laminate is also distinguished, in addition to the low gas permeability values, by high mechanical stability, particularly by high puncture resistance which offers advantages in the handling of the film laminates according to the invention and thus prevents damages of the laminate during wrapping. The VIPs must, in some cases, withstand large mechanical loads, both during manufacture and during installation in the final application, which can lead to damage to the wrapping and thus to the gas barrier properties.
A layer based on polypropylene vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3 which is distinguished by a particularly good water vapour barrier is preferably selected as the outer layer (I). If this outer layer is combined with a layer (III) consisting of a polypropylene layer vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3, which is also distinguished by a particularly good water vapour barrier, the film laminate according to the invention formed therefrom will be distinguished both by a better water vapour barrier compared with the individual polypropylene layers and by an extremely improved oxygen barrier, since the inner gas barrier layer (II) of polyvinyl alcohol is protected from being damaged by water vapour.
One or more of the layers (I) and/or (III) vapour-coated with aluminium or SiOx or a metal oxide from main groups 2 or 3 is also preferably a coextrudate, which consists of at least one layer (a) of polyamide and at least one gas barrier layer (b) of resin. A 3-layer coextrudate as layer (I) and/or layer (III) of polyamide as the outer layers and hydrolysed ethylene vinyl acetate copolymer (EVOH) as oxygen barrier layer inbetween is particularly suitable. The gas barrier layer ensures extremely improved gas barrier values in the resulting film laminate according to the invention, and particularly when EVOH is used as the gas barrier layer the oxygen barrier values are improved.
In a particularly preferred combination, one or more of the layers (I) and/or (III) are vapour-coated with aluminium, preferably in a thickness of 30 to 80 nm.
Homo- or copolyolefins can be used as material for the heat-sealable layer (IV). Linear low density polyethylene (LLDPE), low density polyethylene (LDPE), metallocenic polyethylene, polypropylene (PP), polybutylene (PB), ethylene vinyl acetate copolymers (EVA), high density polyethylene (HDPE), ionomers (IO) and mixtures of these substances, and also amorphous polyester and amorphous polyethylene terephthalate (aPET), are preferred. A multi-layer coextrudate of the heat-sealable layer (IV) of the above materials is also possible according to the invention. The thickness of the heat-sealable layer (IV) is preferably 20 to 200 μm, particularly 50 to 100 μm.
The film laminate according to the invention used for the production of VIPs comprises preferably a heat-sealable layer (IV) of a free-flowing material, particularly an ionomer, that guarantees particularly gas-tight sealed seams under the dusty production conditions typical of VIP manufacture.
For the bond between the individual layers of the laminate according to the invention, commercial reactive adhesives, such as in particular 2-pack polyurethane adhesives, are preferably used. However, polyolefinic adhesion promoters, preferably polyethylene, ethylene ethyl acrylate (EEA) or ethylene methyl methacrylate (EMMA), can also be used. The gas barrier effect of the film laminate according to the invention is not substantially dependent on the type of bond between the individual layers, however.
In the case of the use of the two-pack polyurethane adhesives in particular, it should be ensured that the component composition is selected such that the lowest possible generation of gas takes place.
A further object of the invention is the use of the inventive film laminates as high barrier films, in other words almost gas impermeable barrier films, as wrapping of vacuum insulation panels.
A further object of the invention are vacuum insulation panels with an inventive film laminate as gas tight wrapping of an insulating material or filler. Any type of insulating materials or fillers, as conventionally used in vacuum insulation panels, is possible, particularly an insulating material of polyurethane foam or polystyrene foam each with open cells and/or a filler material of silicium oxide.
Examples of film laminates which describe the film laminates according to the invention in more detail, but which do not limit the scope of the invention, are reproduced below.
EXAMPLES
A film laminate A) of
(I) a polyamide layer vapour-coated with aluminium, vapour-coated surface facing (Ia),
(Ia) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (I),
(II) a polyvinyl alcohol layer as oxygen barrier layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (IV),
(IV) a polyethylene heat-sealable layer.
The film laminate setted out above was produced as follows:
The individual layers (I) and (Ia) vapour-coated with aluminium were first laminated with the vapour-coated sides adjacent to give a first pre-composite (VV1). Thus, the two sensitive coatings were protected from damage by the following operations. This lamination was performed by means of a solvent-containing, polyurethane-based adhesive system, the components of which (polyisocyanate and polyol) were stoichiometrically coordinated so that no CO 2 formation occurs during curing of the adhesive and the bond strength was not effected. A lamination in air-conditioned rooms with (low) defined humidity was advantageous. These peripheral conditions to be observed in principle also applied to all the other laminations.
The polyester layer (III) vapour coated with aluminium was laminated with the metallised side against the PE heat-sealable layer (IV) (pre-composite VV2).
A polyvinyl alcohol layer (II) was laminated on the already produced pre-composite VV1. This pre-composite VV3 was laminated together with the already produced pre-composite VV2 in a final step. The laminations were usually carried out at laminating speeds of between 150 and 250 m/min. Technically, any other speed is possible as these depend particularly on the technical conditions of the laminating machine used.
The film laminate according to the invention exhibited an extreme low permeability for gases and water vapour, respectively, e.g. an oxygen permeability at 23° C. and 75% relative humidity below the limit of detection of 0.05 cm 3 /m 2 d bar determined according to DIN 53380-3 and a water vapour permeability at 38° C. and 90% relative humidity of <0.05 g/m 2 d determined according to DIN 53122.
Further film laminates according to the invention with the following composition were produced in the same way as mentioned above:
B)
(I) A polyamide layer vapour-coated with aluminium, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (II),
(IV) a polyethylene heat-sealable layer.
C)
(I) A polypropylene layer vapour-coated with aluminium, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (IV),
(IV) a polyethylene heat-sealable layer.
D)
(I) A polyamide layer vapour-coated with aluminium, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polypropylene layer vapour-coated with aluminium, vapour-coated surface facing (IV),
(IV) a ionomer heat-sealable layer.
E)
(I) A co-extrudate of polyamide/EVOH/polyamide layer vapour-coated with aluminium, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (IIIa),
(IIIa) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (III),
(IV) an amorphous polyethylene terephthalate heat-sealable layer.
F)
(I) A polyamide layer vapour-coated with aluminium, vapour-coated surface facing (Ia),
(Ia) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (I),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (IIIa),
(IIIa) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (III),
(IV) a polypropylene heat-sealable layer.
G)
(I) A polyamide layer vapour-coated with SiOx, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with SiOx, vapour-coated surface facing (II),
(IV) an ionomer heat-sealable layer.
H)
(I) A polypropylene layer vapour-coated with SiOx, vapour-coated surface facing (II),
(II) a polyvinyl alcohol layer,
(III) a polyester layer vapour-coated with aluminium, vapour-coated surface facing (II),
(IV) a polyethylene heat-sealable layer.
The oxygen permeability of the film laminates B)-H) was below the limit of detection of 0.05 cm 3 /m 2 d bar determined according to DIN 53380-3. | Multi-layer film laminate is described having at least 4 layers comprising at least one layer (I) as surface layer vapor-coated with aluminum or SiOx or a metal oxide from main groups 2 or 3, a gas barrier layer (II), at least one further layer (III) vapor-coated with aluminum or SiOx or a metal oxide from main groups 2 or 3 and a heat-sealable layer (IV), wherein the vapor-coated surface of layer (I) is adjacent to the following layer.
Their use as high gas barrier films as wrapping of vacuum insulation panels is also described. | 8 |
CONTINUITY DATA
[0001] The present application is a continuation of co-pending application Ser. No. 09/828,865 filed on Apr. 10, 2001, and for which priority is claimed under 35 U.S.C. §120, the entire contents of which are hereby incorporated by reference. The present application also claims priority upon U.S. Provisional patent application, Ser. No. 60/197,677, filed Apr. 17, 2000, the entirety of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention is directed toward the field of digital television signal meta data generation, and more particularly to the non-uniform issuance of certain tables included within such meta data.
BACKGROUND OF THE INVENTION
[0003] It is known for a digital television (DTV) signal to include meta data representing information about the contents of the events, e.g., programs, movies, sports games, etc. contained in the DTV signal. For a terrestrially broadcast DTV signal, the Advanced Television Standards Committee (ATSC) has promulgated the A/65 Standard that defines such meta data. The A/65 standard refers to such meta data as program and system information protocol (PSIP) data.
[0004] The PSIP type of meta data is issued periodically. Data of greater importance in the meta data hierarchy is inserted into the DTV signal more frequently than data of lower importance.
[0005] In general, in this art it is desired to maximize the amount of available bandwidth that can be allocated to the transmission of the DTV program content. Unfortunately, meta data consumes bandwidth that otherwise could be used to transmit the corresponding DTV program content. But such meta data is a prerequisite to an A/65 compliant DTV signal, hence it cannot be eliminated to recover bandwidth.
[0006] It is a problem to reconcile the contradictory design criteria of maximizing bandwidth allocated to DTV program content and providing sufficient meta data to ensure compliance with the N65 standard.
SUMMARY OF THE INVENTION
[0007] The invention is, in part, a solution to the problem of how to insert the least amount possible of meta data into the DTV signal and yet still achieve an A/65 compliant DTV signal. In other words, the invention is, in part, a recognition that it is desirable to insert meta data into the DTV signal as infrequently as possible.
[0008] The invention is, also in part, a recognition that: the A/65 standard establishes fixed frequencies of table output for some of the program and system information protocol (PSIP) data tables, e.g., such as the Master Guide Table (MGT), the Virtual Channel Table (VCT) and the System Time Table (STT), but not for some others; and such unfixed output intervals afford opportunities to lessen meta data output thereby reducing bandwidth consumption in the form of PSIP meta data without sacrificing compliance with the A/65 standard.
[0009] The invention provides, in part, a method to determine issuance intervals for like types of tables, respectively, in a digital television packet stream having a plurality of different types of tables that do not have issuance intervals set by a governing standard. Such a method comprises: setting issuance intervals for like ones of the non-governed tables, respectively, to be non-uniform. Such non-uniform issuance intervals can be determined as a function of at least one of an amount of time in the future to which the table corresponds and a degree of probable interest to a viewer. Further, such non-uniform issuance intervals can be weighted so that an issuance interval for a table corresponding to a time nearer the present is smaller than an issuance interval corresponding to a time further in the future.
[0010] Examples of meta data PSIP tables that can benefit from the method according to the invention include extended text tables (ETTs) and event information tables (EITs).
[0011] Each issuance interval between any two instances of an i th table can be determined according to the following equation:
[0000] interval( i th table)=root_time+(increment_time)* i
[0000] where interval(i th table) is the interval between any two instances of the i th table, root_time is a predetermined interval for the table corresponding most closely in time to the present, increment_time is a non-zero scalar and i is a non-zero integer.
[0012] The invention, also in part, provides a program and system information protocol (PSIP) generator to generate tables for a digital television system packet stream, the generator comprising: an interface to receive at least one issuance parameter for like tables that do not all have an issue interval assigned by a governing standard; and a non-uniform interval calculation unit to determine non-uniform issuance intervals for unassigned-interval-ones of said like tables based upon said at least one issuance parameter. Such a PSIP generator embodies the method according to the invention, e.g., as described herein.
[0013] The invention, also in part, provides a processor-readable article of manufacture having embodied thereon software comprising a plurality of code segments to cause a processor to perform the method according to the invention.
[0014] According to an aspect of the invention, there is provided an apparatus for generating at least one table in a broadcast environment, the apparatus comprising: a generator to generate an event information table (EIT) and an extended text table (ETT), the ETT having program guide information for an n-hour span and having a transmission interval, the ETT having a transmission interval and having program description information according to the EIT, wherein the transmission interval of the EIT is shorter than the transmission interval of the ETT.
[0015] According to an aspect of the invention, there is provided a method for generating at least one table in a broadcast environment, the method comprising: generating an event information table (EIT) and an extended text table (ETT), the ETT having program guide information for an n-hour span and having a transmission interval, the ETT having a transmission interval and having program description information according to the EIT, wherein the transmission interval of the EIT is shorter than the transmission interval of the ETT.
[0016] According to an aspect of the invention, there is provided a data structure for generating at least one table in a broadcast environment, the structure comprising: an event information table (EIT) having program guide information for an n-hour span and having a transmission interval: and an extended text table (ETT) having a transmission interval and having program description information according to the EIT, wherein the transmission interval of the EIT is shorter than the transmission interval of the ETT.
[0017] Advantages of the present invention will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus do not limit the present invention.
[0019] FIG. 1 is a block diagram of a PSIP generator according to the invention in the context of typical inputs to it and outputs from it.
[0020] FIG. 2 is an image of a dialog window within a screen of a graphical user interface (GUI) generated by the PSIP data generator according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 is a block diagram of a program and system information protocol (PSIP) data generator according to the invention in the context of system 100 that can produce an Advanced Television Standards Committee (ATSC), standard A/65, compliant digital television (DTV) signal. The system 100 of FIG. 1 includes: a PSIP generator 102 according to the invention; sources of data upon which the PSIP generator operates, such as a source 108 of listing service data, a source 110 of traffic system data and a source 112 of other data; a multiplexer 114 to incorporate the PSIP data from the PSIP generator 102 into an A/65-compliant DTV signal; and a source 116 of audio data, video data, etc.
[0022] In FIG. 1 , the PSIP generator 102 includes an interface unit 104 and a non-uniform interval calculation unit 106 .
[0023] The PSIP generator 102 according to the invention can be implemented by adapting a well known PSIP generator according to the discussion herein. An example of a known PSIP generator is the PSIP BUILDER PRO brand of PSIP generator manufactured and sold by TRIVENI DIGITAL INC. The PSIP BUILDER PRO itself is based upon a programmed PC having a Pentium type of processor using the MICROSOFT WINDOWS NT4.0 operating system. The software can be written in the Java language. The other blocks of FIG. 1 correspond to known technology.
[0024] In FIG. 1 , the invention has been depicted in the context of a digital television broadcast such as a terrestrial broadcast, and more particularly one that is compliant with the Advanced Television Standards Committee (ATSC), where each event is a program, and the schedule data is PSIP data. However, the invention is readily applicable to any television format, e.g., analog terrestrial, analog cable, digital cable, satellite, etc., for which an electronic schedule is maintained and corresponding data is sent to a receiver for the purpose of presenting an electronic program guide (EPG) to a viewer.
[0025] The units 104 and 106 within the PSIP generator 102 do not necessarily correspond to discrete hardware units. Rather, the units 102 and 104 can represent functional units corresponding to program segments of the software that can embody the invention.
[0026] The interface unit 104 can generate a graphical user interface (GUI) that operates to receive at least one issuance parameter for like PSIP tables (e.g., ETTs or EITs) that do not all have an issue interval assigned by the A/65 standard. Such an interface will be described in more detail below with regard to FIG. 2 . The non-uniform interval calculation unit 106 is operable to determine non-uniform issuance intervals for ones of the like PSIP tables that do not have an assigned interval, based upon the issuance parameter(s) received via the interface unit 104 .
[0027] FIG. 2 is an example image of a dialog window 200 (a GUI) that can be generated by the interface unit 104 according to the invention. In FIG. 2 , the dialog window 200 can include: a Cycle Time Settings tab 202 ; a Miscellaneous Settings tab 204 ; a FTP Periodic Update Controls tab 206 ; an “Apply Settings” button 226 ; a “Defaults” button 228 ; a “Refresh” button 230 ; and a “Close” button 232 . The position of the cursor can be indicated via the reverse highlighting 234 . The Cycle Time Settings tab 202 can include a “Cycle Times (in seconds) for EITs:” region 208 , a “Cycle Times (in seconds) for PSIP Tables:” region 210 , a “Cycle Times (in seconds) for PSI Tables:” region 212 and a “Cycle Times (in seconds) for ETTs:” region 214 .
[0028] It is well known that EITs carry program schedule information including program title information and program start information. Each EIT covers a three-hour time span. ETTs carry text messages associated with the EITs, e.g., program description information for an EIT.
[0029] In FIG. 2 , the “Cycle Times (in seconds) for EITs:” region 208 of the dialog window 200 can include: a box 216 in which a user can enter a fixed interval for the EIT 0 table; a box 218 in which a user can enter an increment for the EIT k table; and a box 220 in which a user can enter a maximum number of EIT tables that are to be sent. Usually, the number entered in box 220 will be far smaller than the maximum number of EIT tables permitted by the A/65 standard.
[0030] Also, in FIG. 2 , the “Cycle Times (in seconds) for ETTs:” region 214 can include: a box 222 in which a user can enter a fixed interval for the ETT 0 table; and a box 224 in which a user can enter an increment for the ETT k table.
[0031] The non-uniform interval calculation unit 106 can receive the values in the boxes 216 , 218 , 220 , 222 and 224 from the regions 208 and 214 , respectively, and use them to determine the non-uniform issuance intervals of, e.g., the EIT and ETT tables. Further discussion of the operation of the unit 106 is couched in a particular non-limiting example, for simplicity.
[0032] The A/65 standard recommends a time interval for outputting the zeroith Event Information Table (EIT), i.e., EIT 0 , but provides no guidelines regarding EIT 1 through EIT 128 . For the Rating Region Table (RRT), the A/65 standard recommends a value only for the output frequency of RRT 1 . And no recommendation is made regarding the output frequencies of any of the Extended Text Tables (ETTs).
[0033] Under the A/65 standard, it is left to the discretion of the operator of a PSIP data generation system to select the frequency of table output for the unmentioned tables. The operator could specify an entry for each group of tables, but that would be burdensome because it would require a total of over 500 entries. A simple solution to the problem of unspecified output frequencies would be to set each type of table to the same output frequency, but that creates a problem in that the guidelines for bandwidth specified by the A/65 standard would be exceeded.
[0034] A further consideration to solve the problem, namely of how to insert the least amount possible of meta data into the DTV signal and yet still achieve an A/65 compliant DTV signal, is: How closely in time to the present moment does each table relate? That is, table types such as the EIT describe event information up to two weeks into the future. A user of an electronic program guide that receives such table types will typically want to view event information concerning only the next 24-48 hours. Users typically do not look farther into the future than this because (at least in part) the event schedule information two weeks into the future is much more likely to change than is event schedule information concerning the next 24-48 hours, i.e., the farther into the future, the less reliable the event information becomes.
[0035] Care must be exercised so as not to set the intervals to be too infrequent. This is because the DTV receiver can become stalled waiting for a table to arrive. If the DTV receiver is stalled for 0.5 seconds, a user might not notice or object if she did. But such a delay of, e.g., 4-5 seconds probably would be noticed by, and probably would annoy, the user. This reinforces the need to set short intervals for near term events because users are likely to want to display EPG information about them.
[0036] Again, the invention, in part, provides an interface unit 104 that defines parameters that the non-uniform interval calculation unit 106 then can use to generate the time intervals between tables of the same type. Typically (but not necessarily) the function performed by the unit 106 will be linear, e.g., with a defined start interval (the root_time) and an increment interval (increment_time). For example, if the user desires EIT 0 to be output every half second (root_time) with each succeeding EIT 1 to be output 0.25 seconds less frequently than the preceding EIT, namely EIT i-1 , the user would enter 0.5 seconds as the root_time in box 216 and 0.25 seconds as the increment_time in box 218 . The function for each table EIT-i interval would then be:
[0000]
Time
between
any
two
instances
of
table
i
=
root_time
+
(
increment_time
*
i
)
=
0.5
sec
+
(
0.25
sec
*
i
)
[0000] For example, EIT 12 can be output every 0.5 sec+(0.25 sec*12)=3.5 seconds, which is less frequent than EIT 0 . Obviously, other examples are possible, e.g., the increment_time for each of different groups of like tables can be set.
[0037] A similar calculation for ETTs can be performed by the unit 106 .
[0038] The invention has at least the following advantages: 1) it provides an easy way of entering the interval times for the tables: 2) it defines the interval times for like tables that are not all fixed to a constant interval; and 3) it provides an interval function that increases the interval for tables that represent information further out in time.
[0039] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | An apparatus, method and data structure for generating at least one table in a broadcast environment, are provided. The apparatus includes a generator to generate an event information table (EIT) and an extended text table (ETT). The ETT has program guide information for an n-hour span and has a transmission interval. The ETT has a transmission interval and program description information according to the EIT. The transmission interval of the EIT is shorter than the transmission interval of the ETT. | 7 |
TECHNICAL FIELD
The application relates to sealing of the edges of combustor heat shields to the combustor shell of a gas turbine engine.
BACKGROUND OF THE ART
The combustors of gas turbine engines have a metal support shell that is protected from the heat of combustion gases by a ceramic lining made of multiple heat shields abutting together at their adjacent edges. The combustor shells and heat shields are perforated to permit compressed cooling air to pass from a surrounding plenum through the combustor shell into an intermediate cooling chamber then through the heat shield into the hot gases within the combustor. The heat shield and flow of cooling air prevent direct contact between the metal combustor shell and the hot combustion gases. The flow of cooling air cools the combustor shell and heat shields.
The compressed cooling air contained within the intermediate cooling chamber has a higher pressure than the combustion gases to propel the cooling air into the combustor in the intended direction of flow. Since the heat shields containing the compressed cooling air are made of multiple panels with edge joints and include openings for igniters and fuel nozzles, adequate sealing of the heat shield edges and openings is necessary to ensure that the flow of cooling air is controlled. Production of compressed cooling air in the air compressor of the engine consumes energy and accordingly excessive or uncontrolled leakage of cooling air represents a loss of energy and lower engine efficiency. For example, in some gas turbine engines, significant amount of cooling air is leaked through gaps between the heat shield and combustor wall. The leaked cooling air can be used more efficiently for cooling purposes if leakage volume is reduced and controlled.
It is desirable to reduce the uncontrolled leakage of cooling air around openings and edges of the heat shield panels within a combustor to reduce the unnecessary consumption of cooling air and thereby increase engine efficiency.
SUMMARY
In accordance with a general aspect, there is provided a seal for sealing a gap between a combustor heat shield and an interior surface of a combustor shell, the seal comprising: a first sealing surface on the interior surface of the combustor shell; and a second sealing surface on a rail on an edge of a heat shield, wherein each of the first and second sealing surfaces include first and second projections defining a non-linear leakage path between the projections.
In accordance with a second aspect, there is provided a gas turbine engine combustor comprising: a combustor shell, a heat shield mounted to a combustor wall with a back face of the heat shield in spaced-apart facing relationship with an interior surface of a combustor shell to define an air gap between the heat shield and the combustor shell, a first sealing surface on the interior surface of the combustor shell; and a second sealing surface on a rail extending from the back face of the combustor heat shield, the first and second sealing surfaces having first and second projections defining a non-linear leakage path between the projections.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial cross-sectional view through an example prior art turbo-shaft gas turbine engine having a combustor including interior heat shield liner panels.
FIG. 2 is a detail axial cross-section view through the prior art combustor shell and heat shield panel of FIG. 1 , showing the edge seals of two adjacent heat shield panels with a rail sealed against the interior surface of the combustor shell where solid arrows indicate cooling air inflow and outflow and where dashed arrows indicate leakage past the rail.
FIG. 3 is a detail axial cross-section view of a first embodiment of the invention (similar to FIG. 2 ) showing a rail with two ridges on the heat shield panel and a ridge extending from the combustor shell together creating a castellated labyrinth seal configuration.
FIG. 4 is a detail axial cross-section view showing a second embodiment showing a rail on the heat shield panel with a series of triangular ridges and triangular ridges extending from the combustor shell together creating a serrated labyrinth seal configuration.
FIG. 5 is a detail axial cross-section view similar to FIG. 4 showing a third embodiment where the orientation of the triangular ridges have been reversed compared to FIG. 4 in a serrated labyrinth seal configuration.
DETAILED DESCRIPTION
FIG. 1 shows an axial cross-section through an example turbo-shaft gas turbine engine 1 . It will be understood that the invention is equally applicable to any type of gas turbine engine 1 with a combustor 7 and turbines 11 such as a turbo-fan, a turbo-prop, or auxiliary power units.
In the example, air enters the engine 1 through the intake 3 then into the low-pressure axial compressor 2 and high-pressure centrifugal compressor 4 . Compressed air exits the high-pressure compressor 4 through a diffuser 5 and is contained within a plenum 6 that surrounds the combustor 7 .
The combustor 7 in the example is a reverse flow annular combustor 7 with perforated inner and outer combustor shells 13 (see FIG. 2 ). Fuel is supplied to the fuel nozzles through fuel tubes 8 and fuel is mixed with compressed air from the plenum 6 when sprayed through nozzles into the combustor 7 as a fuel air mixture that is ignited by the igniter 9 . Hot gases from the combustor 7 pass over the nozzle guide vane 10 and drive the turbines 11 before exiting the tail of the engine as exhaust.
As seen in the detail view of FIG. 2 , the inflow of compressed air 12 from the plenum 6 passes through perforations in the combustor shell 13 and enters an intermediate chamber 14 between the combustor shell 13 and the heat shields 15 . The heat shields 15 have perforations to direct an outflow flow of cooling air 16 to enter the combustor 7 . The outflow of cooling air 16 mixes with the fuel-air mixture in the combustor 7 and immediately on exit also forms a cooling air film to cool and protect the heat shields 15 from heat and combustion gases.
The intermediate chamber 14 has a higher internal pressure than the combustor 7 and the heat shields 15 have rails 17 along their external edges to seal the intermediate chamber 14 against the surface of the combustor shield 13 . The combustor shell 13 is generally manufactured by machining of a metal alloy with a high heat resistance or more recently by direct metal laser sintering (DMLS) additive manufacturing. The heat shields 15 are generally cast of ceramic or metal alloy and can be produced by the metal injection molding (MIM) process. Due to manufacturing dimensional tolerances and fitting of two parts with mating surfaces, the assembly will always result in a gap 18 through which some compressed air leakage 19 occurs (shown as dashed arrows). Some degree of air leakage 19 is beneficial since outward air flow purges hot combustion gases that would otherwise be trapped in eddies within the edge joint area of the heat shields 15 .
However leakage through the gap 18 that is uncontrolled or excessive is detrimental since leakage 19 can decrease engine efficiency through increased use of compressed cooling air and dilution of combustion gases. Leakage 19 is especially undesirable in smaller engines since manufacturing tolerances are similar to those of larger engines, however the proportion of air leakage 19 relative to controlled air outflow 16 is greater in smaller engines. The same size of gap 18 will lead to a generally greater proportion of leaked air 19 relative to controlled air outflow 16 in a smaller engine compared to a larger engine. Hence controlling and reducing leakage 19 is desirable especially in smaller gas turbine engines.
The development of the metal injection molding (MIM) process, the direct metal laser sintering (DMLS) process and other additive manufacturing processes allow manufacture of sealing surfaces with detailed shapes and configurations which can be used to reduce cooling air leakage 19 from the intermediate chamber 14 .
FIG. 3 shows a detail of the first embodiment with a seal for sealing the combustor heat shield 15 against the interior surface of the combustor shell 13 to contain compressed cooling air within the intermediate chamber 14 and impede leakage. The seal includes a first sealing surface on the interior surface of the combustor shell having a single rectangular ridge projection 20 and a second sealing surface on the rail 17 on the edge of the heat shield 15 made of an upstream rectangular ridge projection 21 and a downstream rectangular ridge projection 22 . The ridges 20 , 21 , and 22 of FIG. 3 are a castellated series of mating rectangular ridges defining a non-linear leakage path between them.
FIG. 4 shows a second embodiment of the invention where the ridges 23 , 24 are a serrated series of mating triangular ridges. FIG. 5 shows a third embodiment of the invention where the ridges are reversed in orientation compared to FIG. 4 .
In all cases the non-linear leakage path impedes the cooling air leakage by increasing resistance to air flow. For example modelling of the castellated path shown in FIG. 3 reveals that leakage can be reduced by up to 50% or more compared to the prior art path shown in FIG. 2 .
The first projections 20 , 23 on the combustor shell are manufactured using a direct metal laser sintering (DMLS) process which deposits fine powdered metal particles on the surface and melts the particles in an additive manufacturing method. Very accurate and fine detail is possible using this method.
The second projections 21 , 22 , 24 on the rail 17 are manufactured using a metal injection molding (MIM) process which injects fine powdered metal particles in a plastic matrix into a mold. The molded part is treated to remove the plastic matrix and to bond the metal particles together. The MIM process also produces very accurate and fine detail that is not practical using machining or ceramic molding techniques common to the prior art.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. | A seal for sealing a combustor heat shield against an interior surface of a combustor shell, the seal comprising: a first sealing surface on the interior surface of the combustor shell; and a second sealing surface on a rail on an edge of a heat shield,
wherein each of the first and second sealing surfaces include first and second projections defining a non-linear leakage path between the projections. | 5 |
TECHNICAL FIELD
[0001] The present invention relates to a test kit by immunochromatography for detecting influenza A virus, using an antibody specifically causing an antigen-antibody reaction with an influenza A virus nuclear protein but not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS (sodium dodecyl sulfate)-polyacrylamide gel electrophoresis.
BACKGROUND ART
[0002] Influenza means an infectious disease caused by influenza virus. It is known that as the typical symptom, fever, headache, physical weariness, myalgia, arthralgia, and the like suddenly appear, and cough, nasal discharge, and the like follow in tandem, and it is said that these symptoms subside in around a week. As compared with other so-called cold syndromes, characteristics of influenza are the severe systemic symptoms. In order to make an accurate diagnosis, virological support is required. In the time when influenza is epidemic, it is important to make an accurate diagnosis for the patient with a cold symptom whether the patient has influenza or not, not only in view of the appropriate selection of an anti-influenza virus agent for the treatment, but also in view of the epidemiology of the precise grasp of epidemic state and the determination of the effect of influenza vaccine.
[0003] In order to make an accurate pathogen diagnosis of influenza, there is a standard technique of virus separation using a pharyngeal swab or a gargle liquid as the material, however, it takes a longtime to obtain the diagnosis. If the viral genome is detected by using polymerase chain reaction (PCR), a highly precise result can be obtained in a short period of time. However, a PCR method requires a special apparatus, and thus can be performed only in an institute for health or a limited laboratory.
[0004] In recent years, a rapid diagnostic kit with which an influenza antigen can be detected at abed side, in an outpatient care clinic, or the like becomes available on the market, and thus virological diagnosis has become performed easily in a daily clinical practice. A rapid diagnostic kit for influenza (see Patent Literatures 1 to 11), to which a principle of immunochromatography is applied, can obtain a test result by a simple operation in a short period of time using a biological sample such as nasal mucosa or pharyngeal mucosa that can be easily collected, and thus has the advantage of being less burden for both of the patient who is subjected to inspection and the health care worker who carries out the inspection. In addition, in the case where the result of “positive” is obtained, useful information can be provided for a doctor to make an accurate diagnosis. However, a rapid diagnostic kit currently available on the market does not have sufficient detection sensitivity of influenza virus, and thus even if the result of “negative” is obtained, the viral infection cannot be necessarily denied.
[0005] It is known that the amount of the influenza virus detected from nasal mucosa or pharyngeal mucosa of an influenza patient reaches the peak 2 to 3 days after the onset, then decreases rapidly, and disappears in 5 to 7 days. In order to determine as “positive” by a rapid diagnostic kit, it is necessary that the influenza virus proliferates in a living body after the infection and the amount of virus in a biological sample reaches an amount with which the detection sensitivity is available or more. There is a problem of determination of false negative that in a case of a patient in an initial stage of infection that is soon after the start of virus proliferation, a patient in which the proliferation rate of virus is suppressed due to the inoculation of vaccine, or the like, there may be a case where the sufficient amount of virus is not present in the biological sample to determine as positive, and thus the result of the rapid diagnostic kit becomes “negative” although the patient is actually infected with influenza virus. In a clinical practice, a test by a rapid diagnostic kit can stably detect the virus if 24 hours elapses after the onset and a highly precise result can be obtained, however, there may be a case where virus cannot be detected and the accurate determination cannot be obtained within 12 hours after the onset. From the situation described above, re-inspection is carried out for the patient with a result of “negative” on or after the next day depending on the other findings, and the patient has to seek medical attention again, this situation has forced the excessive burden in terms of cost and time.
[0006] In addition, also in view of the selection of an anti-influenza virus agent for treatment, the accurate diagnosis of influenza is required at the earliest possible time of the infection. At the moment, as a representative example of the therapeutic agent for influenza, a neuraminidase inhibitor such as oseltamivir phosphate (trade name: Tamiflu) and zanamivir (trade name: Relenza) is widely used. Neuraminidase plays an important role when influenza virus infects cell and propagates from cell to cell in a living body. A neuraminidase inhibitor inhibits the activity of neuraminidase, thus inhibits the influenza virus proliferated in a cell from exiting outside the cell, and exerts a therapeutic effect by suppressing the propagation of virus between cells. It is considered that an anti-influenza virus agent composed of such a neuraminidase inhibitor is effective if the agent is taken as soon as possible after the onset. It is considered that the agent is ideally taken within 12 hours after the onset, although the sufficient effectiveness can be obtained if the agent is taken within 24 hours after the onset, and the therapeutic effect becomes poor if the agent is taken more than 48 hours after the onset. However, while the treatment with an anti-influenza virus agent is required to be started at an early stage, the side effect of neuraminidase inhibitor is known, in addition, there exists a social request that an anti-influenza virus agent should be appropriately used in preparation for the explosive epidemic of influenza, accordingly the anti-influenza virus agent is required to be prescribed under the accurate diagnosis of influenza virus infection. Therefore, in a rapid diagnostic kit for influenza widely used in a clinical practice, the performance with which the detection sensitivity of influenza virus is improved and the determination of “positive” can be stably obtained with high accuracy at the earliest possible time after the onset and even if particularly within 24 hours after the onset is strongly required.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 2011-069800
Patent Literature 2: JP-A No. 2010-261912
Patent Literature 3: JP-A No. 2007-093292
Patent Literature 4: JP-A No. 2007-033293
Patent Literature 5: JP-A No. 2006-194688
Patent Literature 6: JP-A No. 2006-194687
Patent Literature 7: JP-A No. 2006-189317
Patent Literature 8: JP-A No. 2006-067979
Patent Literature 9: International Publication WO 2009/148150
Patent Literature 10: International Publication WO 2005/007697
Patent Literature 11: International Publication WO 2005/007698
SUMMARY OF INVENTION
Technical Problem
[0018] An object of the present invention is to provide a test kit for influenza A virus that is a test kit for rapid diagnosis of influenza, to which a principle of immunochromatography is applied, and in which the detection sensitivity of influenza A virus is higher than that of a conventional test kit, and the determination of “positive” can be stably obtained with high accuracy at the earliest possible time after the onset of influenza.
Solution to Problem
[0019] The present inventors carried out intensive studies in order to enhance the detection sensitivity of a rapid diagnostic kit for influenza to which a principle of immunochromatography is applied, and to use an antibody having excellent affinity for an influenza A virus nuclear protein, for an antibody immobilized to a chromatography medium and an antibody conjugated with a labeling substance. In consideration that the test kit is used in a clinical practice, it cannot be said that there is no possibility of occurrence of the denaturation of an influenza A virus nuclear protein after the collection of biological sample for test, and there is a request that the characteristics of the antibody used for a test kit are clarified as much as possible, and thus the present inventors searched the antibody not only having excellent affinity for a native influenza A virus nuclear protein but also having similarly high affinity for an influenza A virus nuclear protein that is denatured, for example, separated using SDS-polyacrylamide gel electrophoresis (also referred to as SDS-PAGE), as an antibody used for a test kit, and tried to use the antibody for a test kit. In the antibody showing high affinity even for the influenza A virus nuclear protein separated using SDS-PAGE, there is the advantage that the binding ability can be less affected by the change of the structure of a nuclear protein, and the epitope region recognized by the antibody is also easily clarified. However, even in the case where the antibody having such reactivity is used, it was extremely difficult to exceed the detection sensitivity of a conventional product.
[0020] Therefore, the present inventors have conducted intensive studies in order to develop a test kit that is excellent in exceeding the detection sensitivity of a conventional product, and thus surprisingly have found that the detection sensitivity of a test kit for influenza A virus can be drastically improved when an antibody having excellent affinity for a native influenza A virus nuclear protein but not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE is used as the antibody immobilized to a chromatography medium.
[0021] That is, the present invention relates to a kit for detecting influenza A virus to which a principle of immunochromatography is applied, and in which the antibody immobilized to a chromatography medium is an antibody causing an antigen-antibody reaction with a native influenza A virus nuclear protein but not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE.
[0022] Hereinafter, the present invention will be described in more detail as follows.
[0000] (1) A kit for detecting influenza A virus by immunochromatography, containing: a chromatography medium in which a first antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein is immobilized; and a labeling reagent in which a second antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein is conjugated with a labeling substance,
[0023] wherein the first antibody is an antibody not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-polyacrylamide gel electrophoresis, and the second antibody is an antibody causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-polyacrylamide gel electrophoresis.
[0000] (2) The kit for detecting influenza A virus by immunochromatography according to (1), wherein the first antibody is one or more monoclonal antibodies.
(3) The kit for detecting influenza A virus by immunochromatography according to (1) or (2), wherein the first antibody is an antibody obtained by immunizing a full-length nuclear protein of influenza A virus subtype H1N1.
(4) A method for detecting influenza A virus by immunochromatography, using: a chromatography medium in which a first antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein is immobilized; and a labeling reagent in which a second antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein is conjugated with a labeling substance,
[0024] wherein the first antibody is an antibody not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-polyacrylamide gel electrophoresis, and the second antibody is an antibody causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-polyacrylamide gel electrophoresis.
[0000] (5) The method for detecting influenza A virus by immunochromatography according to (4), wherein the first antibody is one or more monoclonal antibodies.
(6) The method for detecting influenza A virus by immunochromatography according to (4) or (5), wherein the first antibody is an antibody obtained by immunizing a full-length nuclear protein of influenza A virus subtype H1N1.
(7) An agent for detecting influenza A virus, containing: an antibody causing an antigen-antibody reaction with a native influenza A virus nuclear protein but not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-polyacrylamide gel electrophoresis.
(8) The agent for detecting influenza A virus according to (7), wherein the agent for detecting influenza A virus is used for a detection kit by immunochromatography.
(9) The agent for detecting influenza A virus according to (8), wherein the agent for detecting influenza A virus is immobilized to and used for a chromatography medium of a detection kit by immunochromatography.
(10) The agent for detecting influenza A virus according to any one of (7) to (9), wherein the agent for detecting influenza A virus is one or more monoclonal antibodies.
(11) The agent for detecting influenza A virus according to any one of (7) to (10), wherein the agent for detecting influenza A virus is an antibody obtained by immunizing a full-length nuclear protein of influenza A virus subtype H1N1.
Advantageous Effects of Invention
[0025] In the test kit for influenza A virus of the present invention, the detection sensitivity is high, therefore, the determination of “positive” can be obtained using less amount of virus than that in a conventional test kit, thus the determination of false negative is decreased, and the reliability of the determination of “negative” becomes extremely high. Therefore, useful information can be provided for a doctor to make an accurate diagnosis of influenza virus infection for a patient in an initial stage of infection and soon after the start of virus proliferation in the living body, and thus the treatment with an anti-influenza virus agent can be started at an early stage. In addition, even for a patient in which the proliferation rate of virus is suppressed by the inoculation of vaccine, the presence or absence of infection of the influenza virus can be accurately diagnosed, and thus the attention of spread of the infection can be drawn, further the information that is epidemiologically important in order to determine the effect of influenza vaccine can be provided.
[0026] Further, the present invention is to provide an agent for detecting influenza A virus. The diagnosis can be simply and more accurately performed by using an agent for detecting influenza A virus of the present invention, in particular, by using as the antibody immobilized to a chromatography medium of a detection kit by immunochromatography.
BRIEF DESCRIPTION OF DRAWINGS
[0027] FIG. 1 shows reaction results of antibody 1C6, 6F7, or 10G5, and a recombinant nuclear protein of influenza A virus (56 kDa) by Western blotting. M in the upper part of FIG. 1 shows a lane in which a molecular weight marker has been run, and rNP shows a lane in which a recombinant nuclear protein has been run. (a) Shows a result of a reaction of a PVDF membrane to which a full-length recombinant nuclear protein separated using SDS-PAGE has been transferred with antibody 7307. A band is detected in the range of molecular weight of 50 to 75 kDa. The reactivity of antibody 1C6, 6F7 or 10G5 and a recombinant nuclear protein was examined under the conditions that the antigen-antibody reaction of antibody 7307 and a recombinant nuclear protein is confirmed. (b) Shows a result of antibody 1C6. (c) Shows a result of antibody 6F7. (d) Shows a result of antibody 10C5. The reaction of antibody 1C6, 6F7 or 10G5 and a recombinant nuclear protein was not detected under the conditions that the reactivity of antibody 7307 is confirmed.
DESCRIPTION OF EMBODIMENTS
[0028] The present invention is a kit for detecting influenza A virus by immunochromatography using the first antibody and second antibody that cause an antigen-antibody reaction with an influenza A virus nuclear protein but does not substantially cause an antigen-antibody reaction with an influenza B virus nuclear protein, and which is characterized in that as the first antibody immobilized to a chromatography medium, an antibody causing an antigen-antibody reaction with a native influenza A virus nuclear protein but not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE is used.
[0029] Each of the first antibody and the second antibody that are used in the present invention is an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein. Influenza virus is classified into type A, type B, and the like according to the differences in the antigenicity of the nuclear protein. Further, influenza A virus has haemagglutinin (HA) and neuraminidase (NA), which are glycoproteins, on the surface of virus particles, and is classified into various subtypes according to the differences in the structure of these HA and NA. Each of the first antibody and the second antibody that are used in the present invention recognizes a nuclear protein of influenza virus, and thus is an antibody that can cause widely an antigen-antibody reaction with a nuclear protein of various subtypes of influenza A virus, and at least can cause an antigen-antibody reaction with a nuclear protein of subtype H1N1, subtype H3N2, subtype H5N1, and subtype H7N7 of influenza A virus, but does not cause an antigen-antibody reaction with a nuclear protein of influenza B virus. The influenza A virus nuclear protein with which the first antibody and second antibody of the present invention cause an antigen-antibody reaction may be a native protein separated from a virus, or may be a recombinant protein produced based on the nucleic acid sequence of the known nuclear protein gene. Further, the nuclear protein with which the first antibody and second antibody of the present invention cause an antigen-antibody reaction may be a nuclear protein separated and purified from a component of a virus or the unpurified nuclear protein, and if not separated, the nuclear protein may be a nuclear protein derived from a virus that is treated with a surfactant such that the nuclear protein is easily brought into contact with an antibody.
[0030] The “native influenza A virus nuclear protein” in the present invention may be a nuclear protein in which a conformational structure of a naturally existing influenza A virus nuclear protein, at least a conformational structure that is sufficient to maintain the antigen-antibody reaction with a specific antibody is left, and thus the nuclear protein in which a conformational structure of the naturally existing protein is destroyed by SDS-PAGE and the like, and the substantial antigen-antibody reaction of an influenza A virus nuclear protein with the antibody cannot be maintained is removed.
[0031] It can be confirmed by a well-known immunoassay method whether or not the first antibody and second antibody used in the present invention cause the antigen-antibody reaction with a nuclear protein of influenza virus. That is, when the immunoassay method is classified according to the measurement form, there are a sandwich method, a competition method, a agglutination method, and the like, and when the immunoassay method is classified according to the label to be used, there are a fluorescence method, an enzyme method, a radiation method, and the like. Any method among these immunoassay methods can be used for the confirmation of an antigen-antibody reaction. The description of “not substantially causing an antigen-antibody reaction” in the present invention means that in the immunoassay method described above, the antigen-antibody reaction is not caused at a detectable level, or even if the antigen-antibody reaction is caused, the degree of the reaction is obviously weak as compared with the degree of the antigen-antibody reaction with an influenza A virus nuclear protein, and is the same degree as that with other proteins constituting influenza virus, thus is not the specific reaction.
[0032] The first antibody of the present invention is an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein, and further may be an antibody not substantially causing an antigen-antibody reaction with the protein in which the conformational structure at a site where the antigen-antibody reaction of a naturally existing influenza A virus nuclear protein is caused is destroyed. As such an antibody, for example, an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein, and further not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE is preferred.
[0033] The “SDS-polyacrylamide gel electrophoresis” in the present invention means a separation/analysis method of protein that is conventionally used in the technical field to which the present invention pertains, and can be performed in accordance with a method of representatively, Laemmli, U.K. (Nature, 227: 680-685 (1970)), but is not limited to this method. Specifically, the SDS-polyacrylamide gel electrophoresis can be performed, for example, by the following procedures. First, separation gel composed of polyacrylamide at a concentration of 10 to 15% is placed between plates, and on which concentrated gel composed of polyacrylamide at a concentration of 3 to 5% is overlaid, and the produced gel is attached to a slab type electrophoresis apparatus. Into a solution containing an influenza A virus nuclear protein, an equal parts of a 2-fold concentrated sample buffer (125 mM Tris-HCl, 20% glycerol, 2% SDS, 2% 2-mercaptoethanol, 0.001% bromophenol blue, and pH 6.8) is added, and the resulting mixture is subjected to a heat treatment at 100° C. for 5 to 10 minutes to obtain a sample for electrophoresis. The sample for electrophoresis and a commercially available molecular weight marker are added to a lane prepared in concentrated gel, respectively, and electrophoresis is performed at a constant current of 20 mA for 30 to 90 minutes by using a buffer for electrophoresis (192 mM glycine, 0.1% SDS, 24 mM Tris, and pH 8.3). A full-length influenza A virus nuclear protein separated using SDS-PAGE can be obtained as a band corresponding to a molecular weight of around 56 kDa in the separation gel.
[0034] The solution containing an influenza A virus nuclear protein to apply to SDS-PAGE is not limited to anything as long as the amount of the influenza A virus nuclear protein is sufficient to cause an antigen-antibody reaction with an antibody in a Western blotting that is performed finally, for example, 1 to 2 mg, and further the nuclear protein may be purified or unpurified. Examples of the solution containing an influenza A virus nuclear protein include, for example, a suspension of an influenza A virus, influenza HA vaccine available on the market, and a solution of a recombinant influenza A virus nuclear protein.
[0035] In consideration that the binding amount of SDS is around 1.2 to 1.5 per 1 of the protein, SDS in a 2-fold concentrated sample buffer used for SDS-PAGE can be used by appropriately changing the concentration in the range of 0.5 to 5% by weight depending on the amount of an influenza A virus nuclear protein. Further, 2-mercaptoethanol in a 2-fold concentrated sample buffer acts as a reducing agent that cleaves the disulfide bond present in an influenza A virus nuclear protein and may be used by appropriately changing the concentration in the range of 1 to 10% by weight, and instead of which a reducing agent composed of another substance such as dithiothreitol (DTT) can be used.
[0036] The “Western blotting” in the present invention can be performed by transferring a full-length influenza A virus nuclear protein separated using SDS-PAGE on a polyvinylidene difluoride (PVDF) membrane, for example, in accordance with a method of Towbin H., et al. (Proc. Natl. Acad. Sci. U.S.A., 76: 4350-4354 (1979)), but the Western blotting is not limited to this method. Specifically, a PVDF membrane is immersed in 100% methanol for 10 seconds, further in a transfer electrode buffer (192 mM glycine, 5% methanol, 25 mM Tris-HCl, and pH 8.3) for 30 minutes, and used for transfer. The transfer apparatus is assembled as follows: a filter paper, a PVDF membrane, gel in which SDS-PAGE has been completed, and a filter paper are overlaid in this order from the bottom on an anode electrode plate; and on which a cathode electrode plate is fixed. In addition, the filter paper is immersed in a transfer electrode buffer for 2 to 3 minutes in advance. The transfer is performed at a constant current of 1.9 mA/cm 2 for 60 to 90 minutes. The PVDF membrane after the transfer is completed is subjected to a blocking operation by incubation at room temperature for 60 minutes in a blocking solution (0.5% BSA, 10 mM Tris-HCl, 140 mM NaCl, 0.01% Tween20, and pH 7.5). After the blocking is completed, the PVDF membrane is incubated for 5 minutes twice in a washing buffer (10 mM Tris-HCl, 140 mM NaCl, 0.01% Tween20, and pH 7.5) and washed, then incubated at room temperature for 90 minutes with the anti-influenza A virus nuclear protein antibody as a primary antibody and reacted with the antibody. After the reaction with a primary antibody is completed, the PVDF membrane is incubated for 5 minutes twice in a washing buffer for wash, then incubated at room temperature for 60 minutes with a secondary antibody, for example, an antibody that is labeled with a labeling substance such as an enzyme, a fluorescent substance, or a radioactive isotope and is specifically reacted with a primary antibody. After the reaction with a secondary antibody is completed, the PVDF membrane is incubated for 5 minutes twice in a washing buffer for wash, then subjected to the detection in Western blotting by the visualization of the primary antibody that is bound to an influenza A virus nuclear protein transferred in the PVDF membrane in a way the nature of a labeling substance.
[0037] The first antibody of the present invention is an antibody not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE. Herein, the description of not causing an antigen-antibody reaction by Western blotting means that the antigen-antibody reaction is not caused at a detectable level under the conditions of the antibody concentration, the antigen concentration, the substrate concentration, the reaction time, or the like in the standard Western blotting, or means that the antigen-antibody reaction is not caused specifically only with the influenza A virus nuclear protein while binding also to a protein other than the influenza A virus nuclear protein. The confirmation that the first antibody of the present invention does not cause the antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE can be performed such as the following. A commercially available antibody which is confirmed that causes the antigen-antibody reaction with an influenza A virus nuclear protein by Western blotting, for example, item stock number 7307 (manufactured by Medix Biochemica) is used as a positive control antibody. The first antibody is determined whether it cannot detect the influenza A virus nuclear protein under the conditions that the positive control antibody causes an antigen-antibody reaction with an influenza A virus nuclear protein on a PVDF membrane and can detect the nuclear protein. The first antibody of the present invention may be an antibody not causing an antigen-antibody reaction with an influenza A virus nuclear protein in the Western blotting at the same antibody concentration that a positive control antibody can detect the influenza A virus nuclear protein. The first antibody is preferably an antibody not causing the reaction with an influenza A virus nuclear protein at twice the concentration of the positive control antibody, and is more preferably an antibody not causing an antigen-antibody reaction with an influenza A virus nuclear protein at 5 times or 10 times the concentration of the positive control antibody. Further, the first antibody of the present invention may be an antibody not causing an antigen-antibody reaction with an influenza A virus nuclear protein in the Western blotting at the same antigen concentration that a positive control antibody can detect the influenza A virus nuclear protein. The preferred first antibody is an antibody not causing the reaction at twice the antigen concentration that a positive control antibody can detect, and the more preferred first antibody is an antibody not causing an antigen-antibody reaction with an influenza A virus nuclear protein at 5 times or 10 times the antigen concentration that a positive control antibody can detect.
[0038] The first antibody used in the present invention can be produced by the administration of an influenza A virus nuclear protein as an immunogen to an animal such as a mouse, a rat, a guinea pig, a canine, a goat, an ovine, a swine, a horse, and a bovine. The influenza A virus nuclear protein used as an immunogen is not particularly limited to in any form as long as the nuclear protein is present in a large amount and the function as an immunogen is exerted, however, for example, includes a suspension of influenza A virus, influenza HA vaccine available on the market, a solution of a recombinant influenza A virus nuclear protein, and the like. In order to suppress the high immunogenicity of the HA and NA contained in an immunogen, an immunogen may be used after nuclear protein purification by ultracentrifugation (see, for example, J. Biochem., 102: 1241-1249 (1987)) or a protease treatment (see, for example, J. Immunol. Methods, 180: 107-116 (1995)). The first antibody of the present invention is an antibody specifically causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with a full-length influenza A virus nuclear protein separated using SDS-PAGE. Therefore, an influenza A virus nuclear protein used as the immunogen is preferably the protein that has not been treated with a sample buffer for SDS-PAGE containing a reducing agent, is more preferably the protein that has not been treated with SDS that is an anionic surfactant, and is furthermore preferably a native influenza A virus nuclear protein. A preferred immunogen for the first antibody of the present invention is suspensions of influenza A virus in a buffer not containing an anionic surfactant, a full-length recombinant influenza A virus nuclear protein, or the like.
[0039] In the case where the first antibody used in the present invention is a polyclonal antibody, for example, the immunogen can be prepared as the following. An antiserum is prepared from an animal immunized with the influenza A virus nuclear protein described above, and the antiserum is purified, for example, by affinity chromatography using a carrier to which an influenza A virus nuclear protein is bound, and then the antiserum or an immunoglobulin fraction causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein is obtained. The antiserum or the immunoglobulin fraction is incubated with a full-length influenza A virus nuclear protein transferred on a PVDF membrane after SDS-PAGE separation, thus an antibody against the nuclear protein in the antiserum binds to the full-length influenza A virus nuclear protein on a PVDF membrane, and the antibody is separated and removed from the antiserum or the immunoglobulin fraction, accordingly an polyclonal antibody that can be used as the first antibody of the present invention can be prepared.
[0040] In the case where the first antibody used in the present invention is one or more monoclonal antibodies, for example, spleen cells are collected from an animal immunized with the influenza A virus nuclear protein described above, then the obtained spleen cells are subjected to the cell fusion with a tumor cell such as a myeloma cell in accordance with a known technique (see, for example, Nature, 256: 495-497 (1975)), and thus a hybridoma producing the first antibody used in the present invention can be obtained.
[0041] As the method for screening for the hybridoma producing the first antibody, for example, the following procedures can be performed.
[0042] In the primary screening, the hybridomas are screened for an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein in the culture supernatant.
[0043] The primary screening can be performed by a solid phase ELISA method using a purified influenza A virus nuclear protein or a recombinant influenza A virus nuclear protein as an antigen. The antigen is adsorbed to solid-phase carrier such as a microtiter plate, magnetic particles, a nitrocellulose membrane. The antigen adsorbed to the solid phase is brought into contact with the culture supernatant of the hybridoma, and the antibody that becomes to indirectly bind to the solid phase and then is detected by using an antibody labeled with a labeling substance, or the like. In the screening for the intended antibody, an influenza B virus nuclear protein can be used as a negative control antigen.
[0044] As another method of the primary screening, an antibody in a culture supernatant of hybridoma is directly or indirectly immobilized to solid-phase carrier, and then an influenza A virus nuclear protein is brought into contact with the antibody as an antigen. An antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein can be detected by the direct labeling of the antigen or by the indirect labeling of the antigen using a specific antibody or the like.
[0045] The primary screening for the antibody of the present invention can be performed by any method in which an antigen or an antibody is immobilized to a solid phase. Further, a rough selection is performed by using a solid phase to which an antigen is adsorbed, and then a more precise selection can be performed by using a solid phase to which an antibody is immobilized.
[0046] The first antibody of the present invention is an antibody that is immobilized to a chromatography medium and used, therefore, the preferable method of the primary screening is a method in which an antibody in a culture supernatant of a hybridoma is directly or indirectly immobilized to a membranous solid carrier and then an influenza A virus nuclear protein is brought into contact with the antibody since the immobilized antibody in the screening method is similar to that in the embodiment of the invention.
[0047] Antibodies obtained from the primary screening, which causing an antigen-antibody reaction with the influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein, are subjected to the secondary screening. In the secondary screening, the selected hybridoma is a hybridoma producing an antibody not causing an antigen-antibody reaction in Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE. As described above, the full-length influenza A virus nuclear protein separated using SDS-PAGE is transferred onto a PVDF membrane. A culture supernatant of the hybridoma selected in the primary screening is brought into contact with the PVDF membrane, and the detection is performed in Western blotting as described above, as a result, a hybridoma producing the intended antibody can be selected.
[0048] As described in detail in the following Examples, for 6 hybridomas that had been selected in the primary screening and caused a particularly strong antigen-antibody reaction with an influenza A virus nuclear protein, the secondary screening was performed by selecting an antibody not causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE and thus 3 hybridomas are selected. The monoclonal antibodies produced by these hybridomas were immobilized to a chromatography medium, and the detection of an influenza A virus was performed, as a result, in all of the 3 monoclonal antibodies, the determination of positive could be obtained with the detection sensitivity exceeding that of a conventional product. That is, multiple hybridomas producing a monoclonal antibody that is preferable as the first antibody of the present invention could be selected.
[0049] The first antibody of the present invention can be prepared as follows: each hybridoma described above is cultured in a culture medium that is usually used for a cell culture, and the first antibody of the present invention is recovered from the culture supernatant. In addition, the first antibody of the present invention can also be prepared as follows: each hybridoma described above is administered into an abdominal cavity of the animal from which the hybridoma is derived, the ascites is retained, and the first antibody of the present invention is recovered from the ascites.
[0050] The second antibody of the present invention is an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein, and may be an antibody having high affinity to an influenza A virus nuclear protein. In the preferred embodiment, according to the combination with the first antibody, an antibody causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE is used.
[0051] The second antibody of the present invention may be a polyclonal antibody or a monoclonal antibody. In the case of a monoclonal antibody, the second antibody may be a single kind of antibody, or may be a mixture of multiple kinds of antibodies. Further, in the case where a monoclonal antibody is used as the antibody of the present invention, the antibody can also be used as a fragment having affinity with an antigen such as Fab, or F(ab′)2.
[0052] The second antibody used in the present invention can be prepared by using an immunogen that is for the production of the first antibody described above. In the case where the second antibody of the present invention is a polyclonal antibody, blood is collected from the immunized animal, an antiserum causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein or an immunoglobulin fraction in an antiserum is purified as described above, and thus the second antibody of the present invention can be produced. In the case where the second antibody of the present invention is a monoclonal antibody, a hybridoma is produced by a known method, a hybridoma producing an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein in a culture supernatant is screened as described above, and thus the second antibody of the present invention can be produced. In the case where an antibody causing an antigen-antibody reaction by Western blotting with a full-length influenza A virus nuclear protein separated using SDS-PAGE is used as the second antibody of the present invention, the secondary screening by Western blotting is performed according to the procedures described above, an antibody in which an antigen-antibody reaction is detected is selected, and thus the intended antibody can be selected.
[0053] The detection kit of the present invention contains a chromatography medium to which the first antibody described above is immobilized. In the present invention, the first antibody immobilized to a chromatography medium forms a determination site. The chromatography medium used in the present invention is an inactive one composed of a fine porous substance showing capillarity, the material of which is not particularly limited as long as the material does not react with a labeling reagent, a component in the biological sample, and the like, and a known one can be used. Specifically, examples of the chromatography medium include a cellulose derivative such as nitrocellulose, and cellulose acetate; a nylon membrane; filter paper; and glass fiber filter paper.
[0054] The form and size of the chromatography medium is not particularly limited, and any chromatography medium may be used as long as the medium is appropriate in terms of the actual operation and the observation of the results. In order to perform the operation more simply, a support composed of plastic and the like can be provided on the back surface of a chromatography medium. The properties of this support are not particularly limited, but in the case where the observation of the detection results is performed with visual determination, the support has preferably a color that is not similar to the color provided by the labeling substance, and has more preferably colorless or white usually.
[0055] In the chromatography medium, a sample adding site to which a biological sample is added (sample pad, and the like); a site from which a solid component in a sample is removed (solid component separating site, and the like); a developer adding site to which a developer is added; an absorbing site in which a labeling reagent and a developer that have not captured in a determination site are sucked up (absorption pad and the like); a control site showing that the detection is normally performed; and the like may be arbitrarily incorporated. The members of these sites are not particularly limited as long as a sample solution or a developer can be moved by capillarity, and generally the members are selected from multiple porous substances of a nitrocellulose membrane, filter paper, glass fiber filter paper, and the like depending on the intended purpose and used to be arranged so as to be connected by capillary with a chromatography medium to which the first antibody is immobilized.
[0056] As the method of immobilizing the first antibody to a chromatography medium, there are a method of directly immobilizing the first antibody to a chromatography medium by a physical or chemical means, and a method of indirectly immobilizing the first antibody to a chromatography medium by binding the first antibody physically and chemically to a fine particle such as a latex particle and capturing the fine particle in a chromatography medium to immobilize the first antibody there; however, from the view point of the ease of sensitivity adjustment, the method of directly immobilizing the first antibody to a chromatography medium is preferable. As the method of directly immobilizing the first antibody to a chromatography medium, physical adsorption may be used, or covalent binding may be used. Generally, in the case where a chromatography medium is a nitrocellulose membrane or a mixed nitrocellulose ester membrane, the physical adsorption can be performed. In the case where covalent binding is used, the activation of the chromatography medium is performed by cyanogen bromide, glutaraldehyde, carbodiimide, and the like. The chromatography medium and the first antibody can be adsorbed or bound to each other by a method of, for example, a microsyringe, a pen with an adjustment pump, ink jet print, and the like. The form of the determination site is not particularly limited, but the determination site can be formed in a form of a circular spot, a line extending perpendicular to the development direction of a chromatography medium, a number, a letter, a symbol such as +, and −, and the like.
[0057] As needed, a chromatography medium to which the first antibody is immobilized is subjected to a blocking treatment. Examples of the blocking agent that can be used for the blocking treatment include a protein such as bovine serum albumin, skim milk, casein, and gelatin, and further a blocking agent available on the market such as Blocking Peptide Fragment (manufactured by TOYOBO CO., LTD.), and a hydrophilic high molecular polymer.
[0058] The detection kit of the present invention contains a labeling substance to which the second antibody described above and a labeling substance are conjugated. As the labeling substance used in the present invention, an enzyme or an insoluble carrier can be used. As the enzyme, there are alkaline phosphatase, horseradish peroxidase, β-galactosidase, urease, glucose oxidase, and the like, and these can be used together with a known chromogenic substrate corresponding to each enzyme. As the insoluble carrier, a metal particle in a colloidal state, such as gold, silver, and platinum; a metal oxide particle in a colloidal state, such as iron oxide; a nonmetal particle in a colloidal state, such as sulfur; a latex particle composed of a synthetic polymer; and the like can be used. Examples of the metal particle in a colloidal state and the metal oxide particle in a colloidal state include, for example, a gold particle in a colloidal state, a silver particle in a colloidal state, a platinum particle in a colloidal state, an iron oxide particle in a colloidal state, and an aluminum hydroxide particle in a colloidal state. In particular, a gold particle in a colloidal state and a silver particle in a colloidal state are preferable in the point that the gold particle in a colloidal state shows red, and the silver particle in a colloidal state shows yellow, when the particle diameter is appropriate. The average particle diameter of these metal particles in a colloidal state is 1 nm to 500 nm, preferably 10 nm to 150 nm with which particularly strong color tone is obtained, and more preferably in the range of 40 nm to 100 nm. The labeling substance used for a labeling reagent of the present invention is preferably an insoluble carrier, more preferably a metal particle in a colloidal state, and furthermore preferably a gold particle in a colloidal state.
[0059] When, for example, a gold particle in a colloidal state is used as the metal particle in a colloidal state, the gold particle in a colloidal state available on the market may be used. Alternatively, a conventional method, for example, a method in which chloroauric acid is reduced with sodium citrate, can be used to prepare the gold particle in a colloidal state.
[0060] As the method in which the second antibody used in the present invention is conjugated with a labeling substance, a known method of physical adsorption or chemical bond can be used. For example, when the second antibody is labeled with a gold particle in a colloidal state, the second antibody is added into a solution in which gold particles are dispersed in a colloidal state and physically adsorbed with the gold particle, then a bovine serum albumin solution, the above-described blocking agent available on the market, and the like are added to block the particle surface to which an antibody has not been conjugated, and thus the labeling is prepared.
[0061] The labeling reagent of the present invention can be included in a kit of the present invention as another reagent separate from the chromatography medium, however, a labeling reagent retaining portion is provided on the chromatography medium, and in which the labeling reagent can be dried and retained. When the labeling reagent is retained in the labeling reagent retaining portion, the labeling reagent is preferably retained such that the labeling reagent is promptly dissolved in a developer and moved freely by a capillary action. In order to improve the resolubility of labeling reagent, a saccharide such as saccharose, sucrose, trehalose, maltose, and lactose, and a sugar alcohol such as mannitol are added into the labeling reagent and coated, or these substances can be coated in advance, into the labeling reagent retaining portion. The labeling reagent retaining portion can be formed by the direct coating of a labeling reagent to a chromatography medium and then the drying, or a labeling reagent is coated to another porous substance separate from the chromatography medium, for example, cellulose filter paper, glass fiber filter paper, and nylon non-woven fabric, and dried to form a labeling reagent retaining member, then the chromatography medium and the retaining member can be arranged so as to be connected with capillary.
[0062] The biological sample that can be applied to a detection kit of the present invention is not particularly limited as long as it is suspected to contain the influenza A virus, but examples of the preferred sample include a nasal swab, a nasal aspirate, and a throat swab. These biological samples can be applied as it is to a kit of the present invention, however, the sample is usually suspended in or diluted with a developer to be applied.
[0063] The developer used together with a detection kit of the present invention, in general, contains preferably a buffer agent such as phosphate, tris hydroxymethyl aminomethane hydrochloride, HEPES, and a Good's buffer, and an inorganic salt such as sodium chloride, using water as a solvent. Further, as needed, a protein component such as bovine serum albumin (BSA), an antiseptic agent, and the like may be contained. Furthermore, the developer used in the present invention may contain a nonionic surfactant such that the virus particle of influenza virus is destroyed, and the first antibody and second antibody of the present invention are easily brought into contact with the nuclear protein. Examples of the nonionic surfactant to be added into a developer include, for example, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester (trade name “Tween” series), polyoxyethylene p-t-octylphenyl ether (trade name “Triton” series), and polyoxyethylene p-t-nonylphenyl ether (trade name “Triton N” series), but the nonionic surfactant is not limited to these. The content of these nonionic surfactants is not particularly limited, but these nonionic surfactants are used in the range of 0.01 to 10.0% by weight, preferably 0.1 to 5.0% by weight, more preferably 0.1 to 1.0% by weight, and furthermore preferably 0.3 to 1.0% by weight, relative to the weight of the entire developer.
[0064] Using a detection kit of the present invention, influenza A virus can be detected, for example, by the following operation.
[0065] In one embodiment of the present invention, a biological sample collected from a subject is mixed with a labeling reagent in a developer in advance, a complex of a nuclear protein and a labeling reagent is formed, and then the complex is brought into contact with a chromatography medium. The developer containing a nuclear protein-labeling reagent complex moves in a chromatography medium as a mobile phase. When the nuclear protein-labeling reagent complex moves in a determination site of the chromatography medium, the immobilized first antibody captures the complex, and the labeling reagent is indirectly bound to the determination site. The detection or determination of influenza A virus can be performed by the observation of the color development intensity of the labeling reagent present in a determination site visually or using a densitometer and the like, as follows: when the labeling substance is an insoluble carrier, the intensity is detected directly for the carrier; or when the labeling substance is an enzyme, the intensity is detected for the reaction product after the enzyme reacts with a substrate.
[0066] In a further embodiment of the present invention, the detection of influenza A virus can be performed using a chromatography medium having a labeling reagent retaining portion. When the biological sample and the developer are brought into contact with a chromatography medium, these biological sample and developer move in the chromatography medium as a mobile phase, and dissolve the labeling reagent retained in the labeling reagent retaining portion. The labeling reagent dissolved in a mobile phase forms a complex with an influenza A virus nuclear protein in a sample, and moves in the chromatography medium. The nuclear protein-labeling reagent complex that has reached the determination site of the chromatography medium is captured in the first antibody immobilized to the determination site, and thus the labeling reagent is indirectly bound to the determination site. The detection or determination of influenza A virus can be performed by the measurement of the labeling reagent present in the determination site visually, or using a densitometer and the like.
[0067] Hereinafter, the present invention will be explained more specifically with reference to Examples, however, should not be construed to be limited to the Examples.
EXAMPLES
Example 1
Production of Anti-Influenza A Virus Nuclear Protein Antibody
[0068] A recombinant nuclear protein produced based on the amino acid sequence of a nuclear protein derived from influenza A virus A/Puerto Rico/8/34 (H1N1) strain (DDBJ/GenBank database, Accession No. V01084) was used as the immunogen. An equal parts of complete Freund's adjuvant was added into and completely mixed with the immunogen, and then a BALB/c mouse was immunized 4 times in total at 2-week intervals. Spleen cells were collected from the immunized mouse three days after the last immunization, and hybridomas were produced by the fusion of the spleen cells with myeloma cells (P3U1) using a known standard technique. 10 to 15 days after the production of the hybridomas, the screening for an antibody that is specific to an influenza A virus nuclear protein was performed using a culture supernatant of the hybridoma.
[0069] In the primary screening, an antibody causing an antigen-antibody reaction with the influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein was selected by the performing of the following screening operations in series.
[0070] First, according to a solid phase ELISA method, the screening was performed using a microtiter plate as the solid phase, and using recombinant nuclear protein, which is the same protein as an immunogen, as an antigen. That is, 100 μl of a solution containing 10.0 μg/mL of a recombinant nuclear protein in a carbonic acid buffer solution was added in each well of a 96-well plate (SUMILON), and incubated at 4° C. overnight, and thus the antigen was immobilized. Next, each well was washed with PBS containing 0.1% Tween 20 (trade name) (hereinafter, referred to as PBS-Tween), 1% BSA diluted with PBS was added into the well, and the well was blocked at 4° C. overnight. Each well was washed with PBS-Tween, then 100 μL of a culture supernatant was added into the well, and the well was incubated at 37° C. for 1 hour. Each well was washed with PBS-Tween thoroughly, then an alkaline phosphatase labeled anti-mouse Igs antibody (manufactured by Funakoshi Co., Ltd.) diluted 1000 fold was added into each well, and the well was incubated at 37° C. for 1 hour. Each well was washed with PBS-Tween thoroughly, then 100 μL of p-nitrophenyl phosphate was added into each well as a substrate, and the well was incubated at room temperature for 30 minutes. 100 μL of a reaction stop solution was added into each well, and the color developing level was measured at a wavelength of 405 nm. Using a culture supernatant corresponding to a well showing high color development, the screening operation was further performed.
[0071] Next, using a nitrocellulose membrane as the solid phase, and using an influenza A virus as the antigen, the screening was performed with a measurement system of immunochromatography. That is, a culture supernatant was applied onto a nitrocellulose membrane having a size of 35 mm×5 mm, and dried at 37° C. for 1 hour, as a result, the antibody was immobilized to form a determination line. In addition, a culture supernatant and a gold colloidal solution were mixed in a 50 mM HEPES buffer solution, and thus an antibody-sensitized gold colloidal solution was produced. An influenza A virus A/New Caledonia/20/99 (H1N1) strain, or an influenza B virus B/Tokio/53/99 strain as a negative control was suspended in a sample diluent (20 mM phosphate buffer solution (pH 7.4), 0.3% skim milk, 0.3% Tween 20, and 0.15 M sodium chloride), and the suspension was added into each well of a 96-well plate (SUMILON). Further, the antibody-sensitized gold colloidal solution described above was added into each well, and was mixed well with the virus suspension. Into the mixture in each well, the end of the nitrocellulose membrane was inserted, and thus a mixture containing viruses was developed. The nitrocellulose membrane was taken out from the mixture 10 minutes after the development, the color development intensity of the gold colloid captured in the determination line was measured with an immunochromato reader (manufactured by Hamamatsu Photonics K.K.). When the color development intensity exceeds 8.0 mABs, the result was determined to be positive. The antibody used in the measurement system in which a positive result was obtained when the influenza A virus was developed and a negative result was obtained when the influenza B virus was developed, was selected as an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not substantially causing an antigen-antibody reaction with an influenza B virus nuclear protein.
[0072] For the antibody selected in the primary screening, the secondary screening was performed by Western blotting using the recombinant nuclear protein described above, and an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not causing an antigen-antibody reaction with an influenza A virus nuclear protein separated using SDS-PAGE was selected. That is, 0.01 mg/mL of the recombinant nuclear protein described above was mixed with an equal parts of a 2× Tris-Glycine SDS Sample Buffer (manufactured by TEFCO) with 10% 2-mercaptoethanol, the resultant mixture was heated at 100° C. for 10 minutes, and subjected to SDS-PAGE. The SDS-PAGE was performed in accordance with a known standard method by using Ready Gel J5-20% 12 well (manufactured by BIO-RAD). After the electrophoresis a protein was transferred from the gel to a Sequi-Blot PVDF Membrane (manufactured by BIO-RAD) with a blotting apparatus (manufactured by BIO-RAD). The PVDF membrane after the transfer was blocked with immunoblock (DS Pharma Laboratories) at room temperature for 1 hour. The blocking solution was removed, and the PVDF membrane was washed with PBS containing 0.05% Tween 20 (trade name) (hereinafter, referred to as T-PBS) for 10 minutes three times, then the resultant PVDF membrane was incubated at room temperature for 1 hour together with a culture supernatant containing the antibody selected in the primary screening. After washing with T-PBS for 10 minutes three times, the PVDF membrane was incubated at room temperature for 30 minutes with alkaline phosphatase labeled anti-mouse IgG (manufactured by SIGMA) that is diluted 5000 fold with T-PBS. After washing with T-PBS for 10 minutes three times, the PVDF membrane was incubated with 1-Step™ NBT/BCIP (manufactured by PIERCE) that is a chromogenic substrate, and the antibody bound to the PVDF membrane was visualized. A commercially available anti-influenza A virus monoclonal antibody (item stock number 7307, manufactured by Medix Biochemica) is used as the positive control. When the binding of the antibody contained in a culture supernatant cannot be detected under the condition that the binding of the positive control antibody to a PVDF membrane can be detected visually, the antibody was selected as the antibody not causing an antigen-antibody reaction with an influenza A virus nuclear protein separated using SDS-PAG. The hybridoma producing the antibody was cloned, then three independent clones were selected, and named hybridoma 1C6, hybridoma 6F7, and hybridoma 10G5, respectively. In addition, the antibodies produced by hybridoma 1C6, hybridoma 6F7, and hybridoma 10G5 were named antibody 1C6, antibody 6F7, and antibody 10G5, respectively. The subclass of the monoclonal antibody obtained from each of the three hybridoma strains was all IgG1.
[0073] Reaction results of antibodies 1C6, 6F7, and 10G5 in Western blotting with a recombinant nuclear protein of influenza A virus are shown in FIG. 1 . Each concentration of the antibodies was adjusted to 10 μg/mL, and each of the antibodies was reacted with 1.0 μg of a recombinant nuclear protein per lane. As shown in FIG. 1 , a band of 56 kDa corresponding to a full-length influenza A virus nuclear protein was detected by antibody 7307, however, when antibody 1C6, 6F7, or 10G5 was used under the same conditions, the band could not be detected. Further, the amount of the recombinant nuclear protein was increased up to 5.0 μg per lane and the same experiment was performed again, however, in the case where the antibody 1C6, 6F7, or 10G5 was used, the detectable band was not confirmed by Western blotting (data not shown).
Example 2
Production of Test Kit by Immunochromatography
(1) Production of Diluent for Capture Antibody
[0074] Isopropyl alcohol was mixed with 50 mM phosphate buffer solution (pH 7.4) so as to be diluted to 5%, and thus a diluent for the first antibody was prepared.
(2) Production of Determination Site on Chromatography Medium
[0075] One antibody, or two antibodies in combination were selected among the antibodies 1C6, 6F7, and 10G5, and diluted with a diluent for a capture antibody so as to have the total antibody concentration of 1.0 mg/mL. The antibody solution was applied on a nitrocellulose membrane (manufactured by Millipore) having a size of 25×2.5 cm using an applicator (manufactured by BioDot), and dried at 50° C. for 5 minutes, then further dried at room temperature for 1 hour, as a result, a determination site was prepared on a chromatography medium.
(3) Production of Labeling Antibody Solution
[0076] A gold colloidal suspension (manufactured by TANAKA KIKINZOKU KOGYO K.K.: average particle size of 40 nm, and gold concentration of 0.36 mM) was used as the labeling substance. Antibody 7307 alone, or a combination of antibody 7307 and any one of antibodies 1F6, 6G7, and 10G5 was diluted with a phosphate buffer solution (pH 7.4) so as to have the total antibody concentration of 0.05 mg/mL. 0.1 mL of antibody solution was added into 0.5 mL of gold colloidal suspension, and the mixture was left to stand at room temperature for 10 minutes. Next, into the resultant mixture, 0.1 mL of a phosphate buffer solution (pH 7.4) containing 1% BSA was added, and further the mixture was left to stand at room temperature for 10 minutes. After that, the mixture was stirred thoroughly, and subjected to centrifugation at 8000×g for 15 minutes. The supernatant was removed, and 2 mL of a phosphate buffer solution (pH 7.4) containing 0.5% BSA was added into the resultant mixture.
(4) Production of Test Kit by Immunochromatography
[0077] The labeling antibody solution produced in the above (3) was uniformly added into a glass fiber pad (manufactured by Millipore) having a size of 15 mm×300 mm, then dried with a vacuum dryer, as a result, a conjugation pad was produced. Next, a chromatography medium produced in the above (2) was bonded to a base material composed of a backing sheet, and further a conjugation pad, and a sample pad (manufactured by Millipore: 300 mm×30 mm) that is a sample adding site were bonded successively in the upstream of the developing direction, an absorbent pad was bonded in the downstream of the developing direction, then the bonded chromatography medium was cut into a piece having a width of 5 mm, as a result, a test kit by immunochromatography was produced. The size of the absorbent pad per kit was 26 mm×5 mm, and the gold content in the labeling antibody solution used was 1 μg.
(5) Preparation of Developer
[0078] Reagents were added into ultrapure water such that each concentration of the reagents was as follows: 10% Tween 20 was 1%, 0.1 M magnesium sulfate was 5 mM, dimethyl sulfoxide was 0.95%, 20% dextran sulphate sodium (weight-average molecular weight: 500,000) was 2%, and CE510 (manufactured by JSR Corporation) was 2%, and mixed. Further, sodium azide was added and mixed as an antiseptic agent so as to be 0.05%, and thus a developer was produced.
Example 3
Measurement of Influenza A Virus
[0079] Using a test kit produced in the above, a reactivity test with influenza A virus was performed according to the following method, and thus the performance of the test kit of the present invention was examined.
[0080] Nasal mucus was collected from a subject who had been determined to be negative in the infection test of influenza A virus (H3N2) using a PCR method. The collection of nasal mucus was performed as follows: one tube of a suction trap was inserted to the inner part of the nasal cavity of a subject, and the other tube was connected to a suction pump, and the suction pump was set to negative pressure to suck up the nasal mucus. The nasal mucus was diluted 20 fold with a developer, and thus an influenza A virus negative sample was prepared. An inactivated influenza A virus A/Panama/2007/99 (H3N2) was added to the negative sample, and thus an influenza A virus positive sample was prepared.
[0081] 150 μL of each of a positive sample and a negative sample was placed on a sample pad of the test kit and developed, and 10 minutes later these samples were determined visually. When a red line was observed in the determination site, the result was expressed as “+”; when a red line was observed more strongly, the result was expressed as “++”; when a red line was observed but the color was extremely light, the result was expressed as “±”; and when a red line was not observed, the result was expressed as “−”. The results are shown in Table 1.
Comparative Example 1
[0082] In the production of a test kit in Example 2, except that the antibody to be applied in the determination site on a chromatography medium and the antibody to be bound to gold colloid were changed, the measurement of each of a positive sample and a negative sample was performed by the same operation as in Example 3.
[0083] As the antibody applying to the determination site of the chromatography medium, antibody 7307, antibody 1C6, or a combination thereof was used in place of any one of the antibodies 1C6, 6F7, and 10G5 or a combination thereof.
[0084] As the labeling antibody to be conjugated with gold colloid, antibody 6F7 or antibody 10G5 was used in place of the antibody 7307.
[0085] The results are shown in Table 1.
Comparative Example 2
[0086] Using a commercially available test kit for influenza A virus by immunochromatography, ImunoAce Flu (trade name) (manufactured by TAUNS Laboratories, Inc.), the measurement of each of a positive sample and a negative sample was performed by the same operation as in Example 3.
[0087] The results are shown in Table 1.
[0000]
TABLE 1
Antigen concentration
Immobilized
(μg/mL)
antibody
Labeling antibody
0
10
20
40
80
Example 3
Antibody 1C6
Antibody 7307
−
−
±
+
++
Antibody 1C6
Antibody 7307
−
±
+
++
++
Antibody 10G5
Antibody 6F7
Antibody 7307
−
±
+
++
++
Antibody 10G5
Antibody 6F7
Antibody 7307
−
±
+
++
++
Antibody 10G5
Antibody 1C6
Comparative
Antibody 7307
Antibody 6F7
−
−
−
±
+
Example 1
Antibody 10G5
Antibody 7307
Antibody 6F7
−
−
−
±
+
Antibody 1C6
Antibody 10G5
Antibody 1C6
Antibody 6F7
−
−
−
−
+
Antibody 10G5
Comparative
Unknown
Unknown
−
−
−
±
+
Example 2
[0088] When an antibody causing an antigen-antibody reaction with an influenza A virus nuclear protein but not causing an antigen-antibody reaction with a nuclear protein separated using SDS-PAGE (antibody 1C6, 6F7, or 10G5) was used as the immobilized antibody of a test kit by immunochromatography, the test kit exhibited detection sensitivity for the influenza A virus several times higher than that of a test kit (Comparative Example 2) which is conventionally available on the market.
[0089] Particularly, in the case that the antibody causing an antigen-antibody reaction with a nuclear protein separated using SDS-PAGE (antibody 7307) was selected as a labeling antibody, and was used in a test kit in combination with the immobilized antibody described above, the test kit exhibited detection sensitivity higher than that of a conventional test kit.
[0090] On the other hand, when an antibody causing an antigen-antibody reaction also with a nuclear protein separated using SDS-PAGE (antibody 7307) was used as the immobilized antibody (Comparative Example 1), the detection sensitivity was equivalent to that of a conventional commercial product.
Example 4
[0091] Except that inactivated influenza A virus A/New Caledonia/20/99 (H1N1) strain, A/Brisbane/10/2007 (H3N2) strain, or A/Solomon/03/2006 (H1N1) strain was used as the sample in place of the influenza A virus A/Panama/2007/99 (H3N2) strain, the measurement of the sample was performed by the same operation as in Example 3. As the immobilized antibody, antibody 6F7 or antibody 10G5 was used, and as the labeling antibody, antibody 7307 was used.
[0092] The results are shown in Table 2.
[0000]
TABLE 2
Antigen concentration
(μg/mL)
Influenza virus strain
0
10
20
40
80
Example 4
A/Panama/2007/99 (H3N2)
−
±
+
++
++
A/NewCaledonia/20/99(H1N1)
−
±
+
++
++
A/Brisbane/10/2007(H3N2)
−
±
+
++
++
A/Solomon/03/2006(H1N1)
−
±
+
++
++
[0093] The test kit of the present invention could detect an influenza A virus with high sensitivity in spite of the differences in the subtype.
INDUSTRIAL APPLICABILITY
[0094] The test kit for influenza A virus of the present invention has higher detection sensitivity of influenza A virus than that of a conventional test kit, therefore, the determination of “positive” can be obtained using less amount of virus. Accordingly, the test kit of the present invention has extremely high reliability for the determination of “negative” and it has an industrial applicability that the useful test kit can be provided. | The present invention is a test kit for rapidly diagnosing influenza according to the principles of immunochromatography, and the purpose thereof is to provide a test kit for the influenza A virus in which the sensitivity in detecting the influenza A virus is greater than in conventional test kits, and a determination of “positive” is obtained stably and with high precision at an earlier time during the onset of influenza symptoms. The present invention pertains to a kit for detecting influenza A virus, in which an antibody that is in solid phase in the chromatographic medium enters into an antigen-antibody reaction with native nuclear proteins of the influenza A virus, but in Western blots the antibody does not enter into antigen-antibody reactions with full-length nuclear proteins of the influenza A virus that have been separated using SDS-polyacrylamide gel electrophoresis. | 6 |
This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 11/739,781 filed Apr. 25, 2007 now U.S. Pat No. 7,974,716, entitled “Preprogrammed Hearing Assistance Device with Program Selection Based on Patient Usage.”
FIELD
This invention relates to the field of hearing assistance devices. More particularly, this invention relates to a system for programming the operation of a hearing assistance device based on usage of the device by a patient.
BACKGROUND
Hearing loss varies widely from patient to patient in type and severity. As a result, the acoustical characteristics of a hearing aid must be selected to provide the best possible result for each hearing impaired person. Typically, these acoustical characteristics of a hearing aid are “fit” to a patient through a prescription procedure. Generally, this has involved measuring hearing characteristics of the patient and calculating the required amplification characteristics based on the measured hearing characteristics. The desired amplification characteristics are then programmed into a digital signal processor in the hearing aid, the hearing aid is worn by the patient, and the patient's hearing is again evaluated while the hearing aid is in use. Based on the results of the audiometric evaluation and/or the patient's comments regarding the improvement in hearing, or lack thereof, an audiologist or dispenser adjusts the programming of the hearing aid to improve the result for the patient.
As one would expect, the fitting procedure for a hearing aid is generally an interactive and iterative process, wherein an audiologist or dispenser adjusts the programming of the hearing aid, receives feedback from the patient, adjusts the programming again, and so forth, until the patient is satisfied with the result. In many cases, the patient must evaluate the hearing aid in various real world situations outside the audiologist's or dispenser's office, note its performance in those situations and then return to the audiologist or dispenser to adjust the hearing aid programming based on the audiologist's or dispenser's understanding of the patient's comments regarding the patient's experience with the hearing aid.
One of the significant factors in the price of a hearing aid is the cost of the audiologist's or dispenser's services in fitting and programming the device, along with the necessary equipment, such as software, computers, cables, hyproboxes, etc. If the required participation of the audiologist and/or dispenser and the fitting equipment can be eliminated or at least significantly reduced, the cost of a hearing aid can be significantly reduced.
The complexity and cost of fitting hearing assistance devices in general also applies in the fitting of tinnitus masking devices. Tinnitus is a condition wherein a person experiences a sensation of noise (as a ringing or roaring) that is caused from a condition (such as a disturbance of the auditory nerve, hair cells, temporal mandibular joint or medications, to name a few. Tinnitus is a significant problem for approximately 50 million people each year, and some people only find relief with tinnitus maskers. A tinnitus masker looks like a hearing aid, but instead of amplifying sensed sound, it produces a sound, such as narrow-band noise, that masks the patient's tinnitus. Some of these instruments have a trim pot that is used to change the frequency of the masking noise. Such instruments may also have a volume control so the user may select the intensity of the masking that works best.
Most tinnitus maskers are prescribed to patients who do not have significant hearing loss, and the masking sound is designed to be more acceptable to the patient than the tinnitus. For most patients that have significant hearing loss, hearing aids can also provide tinnitus relief. However, there are some patients that need both amplification and tinnitus masking.
The most appropriate masking stimuli to be generated by a tinnitus masker is usually determined by an audiologist or dispenser during a fitting procedure. Like the fitting of a hearing aid, the fitting procedure for a tinnitus masker also tends to be an iterative process which significantly increases the overall cost of the masking device.
What is needed, therefore, is a programmable hearing assistance device that does not require a fitting procedure conducted by an audiologist or dispenser. To obviate the necessity of the programming equipment and the necessity of an audiologist or dispenser fitting procedure, a programmable hearing assistance device is needed which is automatically programmed based on selections made by a patient while using the device or based on usage patterns of the patient. This need applies to hearing aids as well as to tinnitus masking devices.
SUMMARY
The above and other needs are met by a programmable apparatus for improving perception of sound by a person. In one embodiment, the apparatus includes a processor, digital-to-analog converter, audio output section and means for generating first and second control signals. The processor executes one or more available programs for processing digital audio signals based on control signals. The digital-to-analog converter generates output analog audio signals based on the digital audio signals. The audio output section receives and amplifies the output analog audio signals, generates audible sound based thereon and provides the audible sound to the person. The memory stores programs for processing the digital audio signals according to various acoustical configurations or with tinnitus masking stimuli. Based on an action by the person, a first control signal is generated for switching from one available program to another available program. Also based on an action by the person, a second control signal is generated for designating at least one of the available programs as a chosen program. Based on the first control signal, the processor ceases execution of one of the available programs and commences execution of another of the available programs. Based on the second control signal, the processor designates at least one of the available programs as a chosen program for continued use.
In preferred embodiments, the means for generating the first and second control signals comprise a momentary push button switch and a controller. When activated by the person, the momentary push button switch changes from a first state to a second state. The controller generates the control signals based on periods of time during which the momentary push button switch is held in the second state. For example, the controller generates the first control signal when the momentary push button switch is held in the second state for a period of time exceeding a first time. The controller generates the second control signal when the momentary push button switch is held in the second state for a period of time exceeding a second time.
In one embodiment, the programmable apparatus is a hearing aid device and the one or more available programs comprise acoustical configuration programs. In another embodiment, the programmable apparatus is a tinnitus masking device and the one or more available programs comprise masking stimuli programs. In yet another embodiment, the programmable apparatus is a combination hearing aid device and tinnitus masking device, and the one or more available programs comprise acoustical configuration programs and masking stimuli programs.
In some embodiments, the programmable apparatus includes a timer for timing how long each of the available programs is used in processing digital audio signals. Based on how long each of the available programs is used, the processor designates at least one of the available programs as a chosen program for continued use.
In another aspect, the invention provides a method for improving perception of sound by a person. The method includes steps of (a) storing in a memory device one or more available programs for processing digital audio signals, (b) processing the digital audio signals based on execution of the one or more available programs, (c) generating output analog audio signals based on the digital audio signals, (d) receiving and amplifying the output analog audio signals to generate audible sound based thereon, (e) generating a first control signal to switch from one available program to another available program based upon an action by the person, (f) generating a second control signal to designate at least one of the available programs as a chosen program based upon an action by the person, (g) ceasing execution of one of the available programs and commencing execution of another of the available programs based on the first control signal, and (h) designating at least one of the available programs as a chosen program based on the second control signal.
In yet another aspect, the invention provides a programmable hearing aid apparatus comprising a processor, digital-to-analog converter, audio output section, memory and a counter. The processor executes one or more available programs for processing digital audio signals. The digital-to-analog converter generates output analog audio signals based on the digital audio signals. The audio output section receives and amplifies the output analog audio signals, generates audible sound based thereon and provides the audible sound to a person using the hearing aid. The memory stores the one or more available programs for processing the digital audio signals. The counter generates a counter value based on a count of events that are indicative of the application of power to or the removal of power from the programmable apparatus. After a predetermined elapsed time, the processor determines which of the one or more available programs has been used most in processing the digital audio signals. Preferably, the determination of elapsed time is based at least in part on the counter value.
In some embodiments, the programmable apparatus includes a battery for providing power, and the counter is operable to count occurrences of events that are indicative of the removal and replacement of the battery. In one preferred embodiment, the apparatus includes a battery compartment door and a contact switch attached to the battery compartment door. The counter of this embodiment is operable to count a number of times the contact switch is electrically opened or closed.
In some embodiments, the programmable apparatus includes voltage level detection circuitry for detecting a voltage across the battery. In these embodiments, the counter is operable to count a number of times the voltage across the battery increases by a substantial amount indicating that a weak battery has been replaced with a fresh battery.
Some preferred embodiments include an on/off switch for turning the apparatus on and off. In these embodiments, the counter is operable to count a number of times the on/off switch is operated by a user.
Further details of each of these and other embodiments of the invention are provided in the drawings and in the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the invention are apparent by reference to the detailed description in conjunction with the figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
FIG. 1 depicts a functional block diagram of a hearing assistance device according to a preferred embodiment of the invention;
FIGS. 2 and 3 depict a functional flow diagram of the programming of a hearing assistance device according to a first embodiment of the invention;
FIGS. 4 and 5 depict a functional flow diagram of the programming of a hearing assistance device according to a second embodiment of the invention;
FIG. 6 depicts a functional block diagram of a tinnitus masking device according to a preferred embodiment of the invention;
FIG. 7 depicts a functional flow diagram of the programming of a tinnitus masking device according to a preferred embodiment of the invention; and
FIG. 8 depicts a functional block diagram of components of a hearing assistance device according to a preferred embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 depicts one embodiment of a hearing assistance device 10 for improving the hearing of a hearing-impaired patient. The device 10 of FIG. 1 is also referred to herein as a hearing aid. Another embodiment of a hearing assistance device is a tinnitus masking device as shown in FIG. 6 which is discussed in more detail hereinafter.
As shown in FIG. 1 the hearing assistance device 10 includes one or more microphones 12 a - b for sensing sound and converting the sound to analog audio signals. The analog audio signals generated by the microphones 12 a - b are converted to digital audio signals by analog-to-digital (A/D) converters 14 a - 14 b . The digital audio signals are processed by a digital processor 16 to shape the frequency envelope of the digital audio signals to enhance those signals in a way which will improve audibility for the wearer of the hearing assistance device. Further discussion of various programs for processing the digital audio signals by the processor 16 is provided below. Thus, the processor 16 generates digital audio signals that are modified based on the programming of the processor 16 . The modified digital audio signals are provided to a digital-to-analog (D/A) converter 18 which generates analog audio signals based on the modified digital audio signals. The analog audio signals at the output of the D/A converter 18 are amplified by an audio amplifier 20 , where the level of amplification is controlled by a volume control 34 coupled to a controller 24 . The amplified audio signals at the output of the amplifier 20 are provided to a sound generation device 22 , which may be an audio speaker or other type of transducer that generates sound waves or mechanical vibrations which the wearer perceives as sound. The amplifier 20 and sound generation device 22 are referred to collectively herein as an audio output section 19 of the device 10 .
With continued reference to FIG. 1 , some embodiments of the invention include a telephone coil 30 . The telephone coil 30 is small coil of wire for picking up the magnetic field emitted by the ear piece of some telephone receivers or loop induction systems when the hearing assistance device 10 is disposed near such a telephone receiver or loop induction system. Signals generated by the telephone coil 30 are converted to digital signals by an A/D converter 14 c and are provided to the processor 16 . As discussed in more detail below, the converted digital signals from the telephone coil 30 may be used in some embodiments of the invention for resetting or reprogramming the processor 16 , or controlling the operation of the hearing assistance device 16 in other ways.
Some embodiments of the invention also include a wireless interface 32 , such as a Bluetooth interface, for receiving wireless signals for resetting or reprogramming the processor 16 . In some embodiments, the wireless interface 32 is also used to control the operation of the device 10 , including selection of acoustical configuration programs or masking stimuli programs. The wireless interface 32 may also be used to wirelessly deliver an audio signal to the device 10 , such as a music signal transmitted from a wireless transmitter attached to a CD player, or the audio portion of a television program transmitted from a wireless transmitter connected to a television tuner. In various embodiments, the wireless interface 32 comprises a WiFi link according to the IEEE 802.11 specification, an infrared link or other wireless communication link.
As shown in FIG. 1 , a manually operated input device 28 , also referred to herein as a momentary switch or push button, is provided for enabling the wearer to control various aspects of the operation and programming of the hearing assistance device 10 . The push button 28 is preferably very small and located on an outer surface of a housing associated with the device 10 . The push button 28 is located on a portion of the housing that is accessible to the wearer while the wearer is wearing and using the device 10 .
For example, the device 10 may be configured as a behind-the-ear (BTE), in-the-ear (ITE) instrument, with the push button 28 located on an accessible surface of the BTE or ITE instrument. An example of a hearing aid having BTE and ITE portions is described in U.S. Patent Application Publication 2006/0056649, where reference number 34 of FIG. 1 of that publication indicates one possible location for a push button switch on the BTE portion of a hearing aid. The push button 28 may also be located on the ITE portion. It will be appreciated that the invention is not limited to any particular configuration of the device 10 . In various embodiments, the device 10 may comprise an open fit hearing aid, a canal hearing aid, a half-shell configuration, a BTE device, an ITE device or a completely in canal (CIC) device.
The push button 28 is electrically connected to a controller 24 which generates digital control signals based on the state (open or closed) of the switch of the push button 28 . In a preferred embodiment of the invention, the digital control signals are generated by the controller 24 based on how long the push button 28 is pressed. In this regard, a timer is included in the controller 24 for generating a timing signal to time the duration of the pressing of the button 28 . Further aspects of the operation of the controller 24 and the push button 28 are described in more detail below.
A second push button 328 may be included in embodiments of the invention that combine hearing aid functions with tinnitus masking functions. In these embodiments, a push button 328 is used to control the selection of tinnitus masking programs as described in more detail hereinafter. Alternatively, a single push button may be used for first programming the hearing aid functions and then programming the tinnitus masking functions.
Nonvolatile memory 26 , such as read-only memory (ROM), programmable ROM (PROM), electrically erasable PROM (EEPROM), or flash memory, is provided for storing programming instructions and other operational parameters for the device 10 . Preferably, the memory 26 is accessible by the processor 16 and/or the controller 24 .
According to preferred embodiments of the invention, the hearing assistance device 10 is operable in several different modes as determined by its programming. As the terms are used herein, “programs” and “programming” refers to one or more sets of instructions that are carried out by the processor 16 in shaping the frequency envelope of digital audio signals to enhance those signals to improve audibility for the wearer of the hearing assistance device 10 . “Programs” and “programming” also refers to the instructions carried out by the processor 16 in determining which of several stored enhancement programs provides the best improvement for the wearer. FIGS. 2-5 depict the process flow of some exemplary methods for selecting the most effective hearing enhancement program for the wearer.
FIGS. 2 and 3 depict a process flow according to one preferred embodiment of the invention wherein the selection of the most effective enhancement program is based upon a “trial and error” interactive and iterative method, where the wearer of the device evaluates several options for enhancement programs and chooses one or more programs that provide the best enhancement for the individual wearer. As shown in FIG. 2 , a first step in the method is to store in memory 26 some number (N) of primary acoustical configuration programs for shaping the acoustical characteristics of the hearing assistance device 10 (step 100 ). This step may be performed at the time of manufacture of the hearing assistance device 10 or at a later time, such as during a reprogramming procedure. In a preferred embodiment of the invention, seven primary acoustical characteristic configuration programs are loaded into the memory 26 (N=7). However, it will be appreciated that any number of programs may be initially loaded into memory 26 , and the invention is not limited to any particular number.
As the phrase is used herein, a “primary acoustical characteristic configuration program” is an algorithm that sets the audio frequency shaping or compensation provided in the processor 16 . These programs or algorithms may also be referred to by audiologists or dispensers as “gain-frequency response prescriptions.” Examples of generally accepted primary acoustical configuration programs include NAL (National Acoustic Laboratories; Bryne & Tonisson, 1976), Berger (Berger, Hagberg & Rane, 1977), POGO (Prescription of Gain and Output; McCandless & Lyregaard, 1983), NAL-R (NAL-Revised; Byrne & Dillon, 1986), POGO II (Schwartz, Lyregaard & Lundh, 1988), NAL-RP (NAL-Revised, Profound; Byrne, Parkinson & Newall, 1991), FIG. 6 (Killion & Fikret-Pasa, 1993) and NAL-NL1 (NAL nonlinear; Dillon, 1999). It will be appreciated that other primary acoustical configuration programs could be used in association with the methods described herein, and the above list should not be construed as limiting the scope of the invention in any way.
A “secondary acoustical characteristic configuration program” as that phrase is used herein refers to a variation on one of the primary programs. For example, in one of the primary programs, a parameter for gain at 1000 Hz may be set to a value of 20 dB which is considered to be in or near the center of a range for an average hearing loss patient. In an example of a related secondary program, the parameter for gain at 1000 Hz may be set to a value of 25 dB which is just above the “standard” value. Accordingly, another related secondary program may have the parameter for gain at 1000 Hz set to a value of 15 dB which is just below the “standard” value. There may be any number of secondary programs that include various variations of parameters which in the associated primary program are set to a standard or average value. Preferably, 2×N number of secondary acoustical configuration programs are loaded into memory at step 100 . For example, there may be two secondary programs associated with each primary program.
In the preferred embodiment of the invention, a feedback canceller algorithm is also stored in the memory 26 of the device 10 . An example of a feedback canceller algorithm is described in U.S. Patent Application Publication 2005/0047620 by Robert Fretz. As described in more detail below, such an algorithm is used to set the acoustical gain levels in the processor 16 and/or the amplifier 20 to avoid audio feedback in the device 10 .
At some point after the initial programming of the device (step 100 ), a wearer inserts the device 10 into the ear canal (in the case of an ITE device) or places the device 10 behind the ear (in the case of a BTE device) with the associated connections to the ear canal (step 102 ). Once the device 10 is in position, the wearer presses the button 28 for some extended period of time T 1 , such as 60 seconds, to activate the device 10 and initialize the feedback canceller program (step 104 ). According to a preferred embodiment of the invention, the feedback canceller program generates and stores acoustical coefficients that will be applicable to all of the primary and secondary acoustical configuration programs stored in the memory 26 .
Once the feedback canceller program has performed its initialization procedure, the wearer can cycle through the N number of available primary acoustical configuration programs and try each to determine which provides the best enhancement for the wearer's hearing loss. The wearer does this by pressing the button 28 for at least some period of time T 2 , such as one second, to switch from one program to the next (step 108 ). For example, a first program may be executed by the processor 16 when the device 10 is first powered on. When the wearer presses the button 28 for at least one second, a second program is executed by the processor 16 (step 120 ). In some embodiments, the device 10 generates two beeps (step 118 ) to indicate to the selection of the second program. When the wearer presses the button 28 again for at least one second, a third program is executed by the processor 16 (step 120 ) and the device 10 generates three beeps to indicate that the third program is selected. This continues until the wearer has cycled through the N number of programs (such as seven). If the wearer presses the button 28 again for at least one second, the first program is loaded again. This process is represented by steps 108 - 122 of FIG. 2 . To cycle through programs quickly, the wearer may press the button 28 several times consecutively until the desired program is selected. At this point, some number of beeps are generated to indicate which program is selected.
If it is determined that the button 28 is pressed for less than one second (step 110 ), then no new program is loaded and the process waits for the next button press (step 122 ). This prevents inadvertent switching from one program to the next due to an accidental press of the button 28 .
Once the wearer has had a chance to evaluate all of the available primary programs, the wearer may find that some smaller number of the programs, such as two, seem to be used most because they provide the best hearing enhancement for the user in various situations. For example, one of the programs may provide the best performance in normal quiet conversation settings. Another of the programs may provide the best performance in a noisy setting, such as in a crowded room. A preferred embodiment of the invention allows the user to eliminate programs that are not used or rarely used, and to evaluate some secondary programs that are variations on the best performing programs. As described below, this is accomplished by pressing the push button 28 for a time T 3 , such as 30 seconds, which is longer than the time T 2 .
As shown in FIG. 2 , if it is determined that the button 28 is pressed for a time T 3 or longer (step 124 ), such as 30 seconds, the processor 16 sets a flag or stores a value indicating that the currently-loaded primary program has been designated as a chosen program (step 126 ). At this point, the device 10 generates a distinctive sound (step 128 ) to indicate to the wearer that a program has been chosen. In a preferred embodiment, the device 10 allows the user to choose two of the N number of primary acoustical configuration programs. However, it will be appreciated that the device 10 could accommodate designation of more or fewer than two primary acoustical configuration programs as chosen. If it is determined at step 130 that two programs have not yet been chosen, the process waits for the next press of the button 28 (step 122 ).
In an alternative embodiment of the invention, instead of pressing the button 28 to choose a program, the wearer presses the button 28 for at least time T 3 to deactivate a non-chosen program. Thus, it will be appreciated that the invention is not limited to the manner in which programs are designated as chosen or not chosen.
If it is determined at step 130 that two primary acoustical configuration programs have been chosen, then the primary programs that have not been chosen are deactivated (step 132 in FIG. 3 ). Deactivation in this sense means that the non-chosen programs are made unavailable for selection and execution using the procedure of repeated pressing of the button 28 . Thus, at this point, two primary programs are available for selection and execution.
After the wearer has used the device 10 for some extended period of time T 4 (step 134 ), such as 80 hours, two secondary acoustical configuration programs are activated for each of the prioritized primary programs. For example, if two primary programs have been chosen by way of the user selection process of steps 124 - 130 , then four secondary programs are activated at step 136 , resulting in a total of six available programs (N=6). Activation of a program in this sense means to make a program available for selection and execution. In a preferred embodiment of the invention, each of the two newly-added secondary programs are variations on a corresponding one of the chosen primary programs. This allows the wearer to make a more refined selection so as to “fine tune” the desired acoustical response. At this point in this example, the wearer has six available programs to evaluate and the user can cycle through the six programs using the button pressing procedure depicted in steps 138 - 152 of FIG. 3 . This procedure is essentially the same as the procedure of steps 108 - 122 of FIG. 2 .
Once the wearer has had a chance to try and compare the six available programs (two primary and four secondary), the wearer can choose the two programs that provide the best performance and deactivate the rest. This is accomplished by pressing the push button 28 for a time T 3 , such as 30 seconds. As shown in FIG. 3 , if it is determined that the button 28 is pressed for a time T 3 or longer (step 154 ), the processor 16 sets a flag or stores a value indicating that the currently-loaded program has been designated as chosen (step 156 ). At this point, the device 10 generates a distinctive sound (step 158 ) to indicate to the wearer that a program has been chosen. In a preferred embodiment, the device 10 allows the user to choose two of the N number of available programs. However, it will be appreciated that the device 10 could accommodate the choice of more or fewer than two programs.
If it is determined at step 160 that two programs have not yet been chosen, the process waits for the next press of the button 28 (step 152 ). If it is determined at step 160 that two programs have been chosen, then the other four non-chosen programs are deactivated (step 162 in FIG. 3 ). At this point, the two best-performing programs as determined by the wearer are available for continued use. (N=2, step 164 .) The wearer can now switch between the two available programs using the button pressing procedure of steps 138 - 152 .
In some embodiments of the invention, there is no process for activating and choosing secondary acoustical configuration programs. In such embodiments, the wearer chooses some number of best performing primary or secondary programs (such as N=2) and the thereafter the wearer can switch between those chosen programs. This is represented by the dashed line from the box 132 in FIG. 2 with continuation at step 122 . Thus, in these embodiments, processing does not proceed to step 134 in FIG. 3 .
In preferred embodiments of the invention, the programming of the hearing assistance device 10 can be reset to default (factory) conditions by the wearer. In one embodiment, the reset is initiated by pressing the push button 28 for an extended time T 5 , such as two minutes, which is significantly longer than T 3 . In another embodiment, the reset is initiated by closing a battery compartment door while simultaneously pressing the button 28 . This embodiment includes a switch coupled to the battery compartment door, where the status of the switch is provided to the controller 24 . In another embodiment, the reset is initiated by a Dual-Tone Multi-Frequency (DTMF) telephone code received by the telephone coil 30 or microphone 12 a or 12 b . In yet another embodiment, the reset is initiated by a coded wireless signal received by the wireless interface 32 . In some embodiments, more than one of the above procedures are available for resetting the programming of the device 10 .
As described above, in preferred embodiments of the invention, a wearer switches between available programs and chooses programs using the manually operated push button 28 mounted on a housing of the device 10 . In alternative embodiments of the invention, the wearer switches between available programs and chooses programs using a wireless remote control device 33 , such as an infrared, radio-frequency or acoustic remote control. In these alternative embodiments, a push button is provided on the remote control device 33 , and the program selection and choosing process proceeds in the same manner as described above except that the wearer uses the push button on the remote control device 33 rather than a button mounted on the housing of the device 10 . In an embodiment including an acoustic remote control, coded acoustic signals, such as a series of clicks in a machine recognizable pattern, may be used to deliver commands to the device 10 . Such acoustic control signals may be received by one or both of the microphones 14 a - 14 b and provided to the processor 16 for processing.
In yet another embodiment incorporating voice recognition technology, the wearer switches between available programs and chooses programs by speaking certain “code words” that are received by one or more of the microphones 12 a - 12 b , converted to digital control signals and processed by the processor 16 to control operation of the device 10 . For example, the spoken phrase “switch program” may be interpreted by the processor 16 in the same manner as a push of the button 28 for a time T 2 , and spoken phrase “choose program” may be interpreted by the processor 16 in the same manner as a push of the button 28 for a time T 3 .
FIGS. 4 and 5 depict a process flow according to another preferred embodiment of the invention wherein the designation of the most effective enhancement programs is based upon a method wherein the wearer of the device evaluates several options for enhancement programs and the device 10 keeps track of how long the wearer uses each program. With this embodiment, the basic assumption is that the program which provides the best performance for the wearer will be the program used most during the evaluation period. As described below, a variation on this embodiment allows the wearer to “override” the time-based designation process and manually choose one or more programs that provide the best performance. This override feature may be provided as an optional operational mode.
As shown in FIG. 4 , a first step in the method is to store in memory 26 some number (N) of primary acoustical configuration programs and 2×N number of secondary programs (step 200 ). This step may be performed at the time of manufacture of the hearing assistance device 10 or at a later time, such as during a reprogramming procedure. In a preferred embodiment of the invention, seven primary programs and fourteen secondary programs are loaded into the device memory 26 (N=7, 2×N=14). However, it will be appreciated that any number of programs may be initially loaded into memory 26 , and the invention is not limited to any particular number. In the preferred embodiment of the invention, a feedback canceller algorithm is also stored in the memory 26 of the device 10 at step 200 .
At some point after the initial programming of the device (step 200 ), a wearer inserts the device 10 into the ear canal (in the case of an ITE device) or places the device 10 behind the ear (in the case of a BTE device) with the associated connection to the ear canal (step 202 ). Once the device 10 is in position, the wearer presses the button 28 for some extended period of time T 1 , such as 60 seconds, to activate the device 10 and initialize the feedback canceller program (step 204 ). According to a preferred embodiment of the invention, the feedback canceller program generates and stores acoustical coefficients that will be applicable to all of the primary and secondary acoustical configuration programs stored in the memory 26 .
Once the feedback canceller program has performed its initialization procedure, the wearer can cycle through the N number of available primary acoustical configuration programs and try each to determine which provides the best enhancement for the wearer's hearing loss. The wearer does this by pressing the button 28 for at least some period of time T 2 , such as one second, to switch from one program to the next (step 208 ). For example, a first program may be executed by the processor 16 when the device 10 is first powered on. When the wearer presses the button 28 for at least one second, a second program is executed by the processor 16 (step 220 ). In some embodiments, the device 10 generates two beeps (step 218 ) to indicate to the selection of the second program. When the wearer presses the button 28 again for at least one second, a third program is executed by the processor 16 (step 220 ) and the device 10 generates three beeps to indicate that the third program is selected. This continues until the wearer has cycled through the N number of programs (such as seven). If the wearer presses the button 28 again for at least one second, the first program is loaded again. This process is represented by steps 208 - 228 of FIG. 4 . To cycle through programs quickly, the wearer may press the button 28 several times consecutively until the desired program is selected. At this point, some number of beeps are generated to indicate which program is selected.
As with the previously described embodiment, if it is determined that the button 28 is pressed for less than one second (step 210 ), then no new program is loaded for execution and the process waits for the next button press (step 228 ). This prevents inadvertent switching from one program to the next due to an accidental press of the button 28 .
In the embodiment of FIG. 4 , a timer circuit is used to time how long each selected primary program is used (step 222 ). The total time of use of each primary program is logged in memory and is continuously updated as the wearer switches from one program to another. After the wearer has used the device 10 for some extended period of time T 5 , such as 80 hours (step 226 ), a calculation is made based on the logged time information to determine which two primary programs have been used most during the T 5 period (step 230 ). The two primary programs having the highest usage time are then designated as chosen (step 232 ) and the remaining primary programs are deactivated (step 234 ). The wearer then uses the device 10 with the two chosen primary programs activated for a period of time T 6 , such as 80 hours (step 236 ). During this time, the wearer can switch between the two programs as desired.
At the end of the T 6 period, the wearer has used the device 10 for a total time of T 5 +T 6 , such as 160 hours total. At this point, two secondary acoustical configuration programs are activated for each of the two active primary programs, resulting in a total of six available programs (N=6) (step 238 ). In a preferred embodiment of the invention, each of the two newly-added secondary programs is a variation on a corresponding one of the two most-used primary programs. This allows the wearer to make a more refined selection so as to “fine tune” the desired acoustical response. At this point in this example, the wearer has six available programs to evaluate and the wearer can again cycle through the available programs using the button pressing procedure depicted in steps 208 - 228 of FIG. 4 .
During the evaluation period of the N number of available primary and related secondary programs, the timer circuit is again used to time how long each program is loaded for use (step 222 ). The total time of use of each program is logged in memory and is continuously updated as the wearer switches from one program to another. After the wearer has used the device 10 for a total period of time T 7 (such as 240 hours, which is significantly greater than the sum of T 5 +T 6 ) (step 224 ), a calculation is made based on the logged time information to determine which two of the N number of available programs have been used most since the secondary programs were activated (step 240 ). The two programs having the highest usage time are then designated as chosen (step 242 ) and the remaining programs are deactivated (step 244 ). At this point, the two most-used programs as determined by the time-logging procedure are available for continued use. (N=2, step 246 .) The wearer can now switch between the two available programs using the button pressing procedure of steps 208 - 228 .
As mentioned above, a preferred embodiment of the invention allows a wearer to override the time-based selection process and to manually choose one or more programs that provide the best performance for the wearer. This override option is depicted in FIG. 5 and the dashed box portion of FIG. 4 . At step 248 , if it is determined that the button 28 is pressed for a time T 3 or longer, such as 30 seconds, the processor 16 sets a flag or stores a value indicating that the currently-loaded program has been designated as chosen (step 250 in FIG. 5 ). At this point, the device 10 generates a distinctive sound (step 252 ) to indicate to the wearer that a program has been chosen. In a preferred embodiment, the device 10 allows the user to choose two of the available acoustical configuration programs. However, it will be appreciated that the device 10 could accommodate the choice of more or fewer than two acoustical configuration programs.
If it is determined at step 254 that two primary programs have not yet been chosen, the process waits for the next press of the button 28 (step 228 in FIG. 4 ). If it is determined at step 254 that two primary programs have been chosen, then the non-chosen primary programs are deactivated (step 256 in FIG. 5 ). Thus, at this point, two primary programs are available for use. If the wearer has not yet used the device 10 for at least a total period of time T 6 (such as 80 hours) (step 258 ), then processing continues at step 236 of FIG. 4 .
After the wearer has used the device 10 for a time T 6 (such as 80 hours) with two primary programs designated as chosen, two secondary programs are activated for each of the two active primary programs, resulting in a total of six available programs (N=6) (step 238 ). At this point in this example, the wearer again has six available programs from which to choose, and the wearer can again cycle through the six available programs using the button pressing procedure depicted in steps 208 - 228 of FIG. 4 . In this embodiment, the time-logging processing continues as described above unless and until the wearer overrides the procedure by pressing the button 28 for longer than time T 3 (step 248 ). This transfers processing back to step 250 of FIG. 5 where the processor 16 sets a flag or stores a value indicating that the currently-loaded program has been designated as chosen. Once two programs have been chosen (step 254 ), the non-chosen primary and secondary programs are deactivated (step 256 ), leaving two programs available for selection.
At this point, the wearer has used the device 10 for at least a total period of time T 6 (such as 80 hours) (step 258 ), so that processing continues at step 246 of FIG. 4 . Two programs are now available for continued use. These two programs were chosen based on the time-logging procedure, or the override procedure, or a combination of both. The wearer can now switch between the two available programs as desired using the button pressing procedure of steps 208 - 228 . If so desired, the programming of the device 10 may be reset to default conditions as described above using the button 28 , the wireless interface 32 or the telephone coil 30 , as described above.
FIG. 6 depicts one embodiment of a hearing assistance device 300 for masking tinnitus. The device 300 , which is also referred to herein as a tinnitus masker, includes a digital processor 316 for processing digital audio signals, such as masking stimuli signals. In one preferred embodiment of the invention, the masking stimuli signals comprise narrow-band audio noise. The audio frequencies of these noise signals generally fall into the human audible frequency range, such as in the 20-20,000 Hz band. In one sense, “processing” these masking stimuli signals means accessing digital audio files (such as .wav or .mp3 files) from a digital memory device 326 and “playing” the files to generate corresponding digital audio signals. In another sense, “processing” the masking stimuli signals means to determine which digital audio files to access from memory 326 based on which frequency ranges of narrow-band noise have been designated as chosen. In yet another sense, “processing” the masking stimuli signals means to generate the masking stimuli signals using an audio masking stimuli generator program executed by the processor 316 . In any case, the masking stimuli signals are provided to a D/A converter 318 which converts them to analog audio signals. The analog audio signals at the output of the D/A converter 318 are amplified by an audio amplifier 320 where the level of amplification is controlled by a volume control 334 coupled to a controller 324 . The amplified audio signals at the output of the amplifier 320 are provided to a sound generation device 322 , which may be an audio speaker or other type of transducer that generates sound waves or mechanical vibrations which the user perceives as sound. The amplifier 320 and sound generation device 322 are referred to collectively herein as an audio output section 319 of the device 300 .
In a preferred embodiment of the invention, the masking stimuli signals comprise narrow-band noise signals. However, it will be appreciated that other types of masking stimuli could be generated according to the invention, including frequency-modulated noise or speech babble noise. Thus, the invention is not limited to any particular type of masking stimuli.
As shown in FIG. 6 , a manually operated momentary switch 328 , also referred to herein as a push button 328 , is provided for enabling the user of the device 300 to control various aspects of the operation and programming of the device 300 . The push button 328 is preferably very small and located on an outer surface of a housing associated with the device 300 . In an embodiment wherein the device 300 is worn on or in the ear of the user, the push button 328 is located on a portion of the housing that is accessible to the user while the user is wearing and using the device 300 . For example, the device 300 may be configured as a behind-the-ear (BTE) or in-the-ear (ITE) instrument, with the push button 328 located on an accessible surface of the instruments. In an alternative embodiment of the invention, the wearer switches between available masking stimuli programs and chooses programs using a wireless remote control device 333 , such as an infrared, radio-frequency or acoustic remote control.
In one alternative embodiment, the tinnitus masking device 300 is disposed in a housing suitable for tabletop use, such as on a bedside table. In this “tabletop” embodiment, the push button 328 and volume control 334 may be located on any surface of the housing that is easily accessible to the user. The sound generation device 322 of this embodiment is preferably a standard audio speaker such as may typically be used in a tabletop clock radio device. It could also have an extension pillow speaker.
The push button 328 is electrically connected to a controller 324 which generates digital control signals based on the state (open or closed) of the switch of the push button 328 . In a preferred embodiment of the invention, the digital control signals are generated by the controller 324 based on how long the push button 328 is pressed. In this regard, a timer is included in the controller 324 for generating a timing signal to time the duration of the pressing of the button 328 . Further aspects of the operation of the controller 324 and the push button 328 are described in more detail below.
Nonvolatile memory 326 , such as read-only memory (ROM), programmable ROM (PROM), electrically erasable PROM (EEPROM), or flash memory, is provided for storing programming instructions, digital audio sound files and other operational parameters for the device 300 . Preferably, the memory 326 is accessible by one or both of the processor 316 and the controller 324 .
FIG. 7 depicts a process flow according to one preferred embodiment of the invention wherein the selection of most effective masking stimulus for tinnitus masking is based upon a “trial and error” interactive and iterative method where the user of the device 300 evaluates several options for noise frequency and chooses a frequency range that provides the best masking experience for the individual user. As shown in FIG. 7 , a first step in the method is to store in memory various parameters for generating some number (N) of “programs” for generating narrow-band noise using the device 300 (step 350 ). When referring to the operation of the tinnitus masking device 300 , a “program” may refer to various stored commands, values, settings or parameters that are accessed by masking stimuli generation software or firmware to cause the software or firmware to generate masking stimuli within a particular frequency band or masking having particular spectral aspects. In another sense, “program” may refer to a specific digital audio file (.wav, .mp3, etc.) containing masking stimuli, such as audio noise in a particular frequency band or having particular spectral aspects. The step 350 may be performed at the time of manufacture of the device 300 or at a later time, such as during a reprogramming procedure.
A user of the tinnitus masking device 300 can cycle through N number of available masking stimuli programs and evaluate each to determine which provides the best masking for the user's tinnitus condition. The user does this by pressing the button 328 for at least some period of time T 2 , such as one second, to switch from one masking program to the next (step 356 ). For example, a first masking program may be activated when the device 300 is first powered on. When the wearer presses the button 328 for at least one second, a second masking program is loaded from memory 326 to the processor 316 and the device 300 generates two beeps (step 366 ) to indicate to the user that the second masking program is loaded. When the wearer presses the button 328 again for at least one second, a third masking program is loaded from memory 326 to the processor 316 and the device 300 generates three beeps to indicate that the third masking program is loaded. This continues until the user has cycled through the N number of masking programs. If the wearer presses the button 328 again for at least five seconds, the first program is loaded for execution again. This process is represented by steps 356 - 370 of FIG. 7 .
If it is determined that the button 328 is pressed for less than one second (step 358 ), then no new masking program is loaded and the process waits for the next button press (step 370 ). This prevents inadvertent switching from one masking program to the next due to an accidental press of the button 328 .
Once the user has had a chance to evaluate all of the available masking stimuli programs, the user may find that some smaller number of the programs, such as one or two, seem to be used the most because they provide the best masking performance for the user in various situations. For example, one of the masking stimuli programs may provide the best masking when the user is trying to sleep. Another of the masking stimuli programs may provide the best masking when the user is trying to concentrate while reading. A preferred embodiment of the invention allows the user to eliminate masking stimuli programs that are not used or rarely used, and to evaluate some additional masking stimuli programs that are variations on the best performing programs. This is accomplished by pressing the push button 328 for a time T 3 , such as 30 seconds, which is longer than the time T 2 , as described below.
As shown in FIG. 7 , if it is determined that the button 328 is pressed for a time T 3 or longer (step 372 ), the processor 316 sets a flag or stores a value indicating that the currently-loaded masking stimulus program has been designated as chosen (step 374 ). At this point, the device 300 generates a distinctive sound (step 376 ) to indicate to the user that a preferred masking stimulus program has been chosen. The masking stimuli programs not chosen are then deactivated (step 378 ). Deactivation in this sense means that the non-chosen programs are no longer available for selection using the procedure of repeated pressing of the button 328 .
After the user has used the device 300 for some extended period of time T 4 (step 380 ), such as 40 hours, the frequency band of the chosen program is “split” to provide two additional masking stimuli programs (step 382 ). In the preferred embodiment of the invention, the two new programs provide masking stimuli in two frequency bands that are sub-bands of the frequency band of the chosen masking stimuli program. For example, in a case where the chosen program provides masking stimuli in the 1000-3000 KHz band, one of the newly activated programs may cover 1000-2000 KHz and the other newly activated program may cover 2000-3000 KHz. At this point, three masking stimuli programs are available for continued use and evaluation (N=3, step 384 ).
The user can now switch between the three available masking stimuli programs using the button pressing procedure of steps 356 - 370 to decide which of the three provides the best masking performance. As described above, the user designates one of the three masking stimulus programs as chosen by pressing the button 328 for at least the time T 3 (step 372 ). The process steps 374 - 384 are then performed based on the newly-chosen masking stimulus program. This selection procedure may be repeated any number of times to allow the user to “tune in” on the most effective masking stimulus program.
Once the user is satisfied with a particular masking stimulus program, the user presses the button 328 for a time T 4 , such as 30 seconds (step 386 ), at which point all non-chosen masking stimuli programs are removed or deactivated (step 388 ). From this point forward, the tinnitus masking device 300 operates indefinitely using the one selected masking stimulus program.
In an alternative embodiment of the invention, instead of pressing the button 328 to choose a masking stimuli program, the wearer presses the button 328 for at least time T 3 to deactivate a non-chosen program. Thus, it will be appreciated that the invention is not limited to the manner in which masking stimuli programs are designated as chosen or not chosen.
As with the hearing assistance device 10 , the tinnitus masking device 300 may be reset to default (factory) conditions by the user. In one embodiment, the reset is initiated by pressing the push button 328 for an extended time T 5 which is significantly longer than T 4 , such as two minutes. In another embodiment, the reset is initiated by closing the battery compartment while simultaneously pressing the button 328 . In yet another embodiment, the reset is initiated using the wireless remote control device 333 .
In one alternative embodiment, the invention provides a hearing assistance device which is combination hearing aid and tinnitus masker. This embodiment comprises components as depicted in FIG. 1 , which include the push button 28 for controlling the selection of hearing aid acoustical configuration programs for the hearing aid function (as described in FIGS. 2-5 ) and a second push button 328 for controlling the selection of masking stimuli programs for the tinnitus masking function (as described in FIG. 7 ). Alternatively, a single push button may be used for first programming the hearing aid functions and then programming the tinnitus masking functions. Those skilled in the art will appreciate that the processor 16 and controller 24 may be programmed to implement the hearing aid functions and the tinnitus masking functions simultaneously.
In some preferred embodiments of the invention, instead of or in addition to using a clock signal to determine elapsed operational time of the hearing assistance device 10 (or tinnitus masking device 300 ), elapsed time is determined based on counting the number of times various events occur during the lifetime of the device. For example, since the battery of a hearing assistance device must be replaced periodically, one can count the number of times the battery is replaced to approximate the elapsed operational time of the device. Also, since hearing assistance devices are typically removed and powered down each evening, one can count the number times a device has been cycled on and off, either by opening the battery compartment or by operating an on/off switch, to approximate the elapsed operational time.
Various batteries used in hearing assistance devices have operational lifetimes ranging from about 3 days to about 30 days, where the exact lifetime depends on the capacity of the particular battery and the power demand of the hearing assistance device. Accordingly, if the expected lifetime of a particular battery in a particular hearing assistance device is 10 days, and the battery has been replaced three times, then one can estimate that the hearing assistance device has been in use for about 30 days. In a preferred embodiment of the invention, the expected lifetime of the battery is a value that is stored in the memory 26 of the hearing assistance device. This value may be updated depending on the particular model of battery in use and the expected power demand of the particular hearing assistance device.
As shown in FIG. 8 , the opening and closing of battery compartment door contacts 42 provide an indication that the battery compartment door has been opened and closed. For example, a set of electrical contacts are provided which are closed when the battery compartment door is closed and open when the compartment door is opened. A door contact detection module 44 monitors the battery compartment contacts 42 and generates an “on” or “high” logic signal when the contacts 42 are open and an “off” or “low” logic signal when the contacts 42 are closed. This logic signal is provided to a counter 40 which is incremented each time the signal goes high. A counter value of n indicates that the battery compartment door has been opened n times, indicating either n number of battery replacements or n number of times that the device has been powered down by opening the battery compartment. The counter value is preferably stored in the nonvolatile memory device 26 . For a typical device (having no separate power on/off switch) that is powered down at the end of each day by opening the battery compartment door, a value n may indicate a total use time of n days. If a device does have a separate on/off switch, and the battery is typically removed only when it is being replaced, a value n may indicate a total use time of n×x days, where x is the expected lifetime of the battery in days.
As also shown in FIG. 8 , a voltage level detection module 38 may be provided which monitors the voltage of the battery 36 . The voltage level detection module 38 may generate an “on” or “high” logic signal whenever the battery voltage increases by some number of volts, indicating that an old battery has been replaced with a fresh one. This logic signal is provided to the counter 40 which is incremented each time the signal goes high. Similar to the battery replacement example above, a counter value of n indicates that the battery has been replaced n times, which indicates a total use time of n×x days.
With continued reference to FIG. 8 , a momentary on/off switch 48 may be provided to turn the hearing assistance device 10 on and off. For example, the switch 48 may be pressed once to turn the device on and once again to turn the device off. An on/off switch detection module 46 monitors the on/off switch 48 and generates an “on” or “high” logic signal each time the switch 48 is operated. This logic signal is provided to the counter 40 which increments each time the signal goes high. A counter value of n indicates that the device 10 (or the device 300 ) has been cycled on and off n/2 times. For example, if a device is typically turned on and off once per day, a counter value of n indicates the device has been in use for 2 days.
Accordingly, in each operation depicted in FIGS. 2-5 and 7 wherein a value for the total elapsed operational time of the device is needed, this time value may be determined based on the counter value generated by the counter 40 . For example, the counter value may be used to determine the time value in step 134 of FIG. 3 , the time value in step 222 of FIG. 4 , the time value in step 258 of FIG. 5 , and the time value in step 380 of FIG. 7 .
It will be appreciated that a combination of two or more counter values may be used to calculate an elapsed operational time value. For example, one counter value may keep track of the number of times the battery compartment door contacts have opened/closed and another counter value may keep track of the number of times the battery voltage goes from a low value to a high value. In this example, if one counter value indicates that the battery compartment door has been opened/closed once and the other counter value indicates that the battery voltage has not changed significantly, this may indicate that the battery compartment door was opened to power down the device, but the battery was not replaced.
In another example, the on/off switch counter value may indicate that the device has been in operation for 30 days, and the battery voltage level counter value may indicate that the device has been in operation for 40 days. In various embodiments, an average of these two time values, the greater of these two time values, or the lesser of these two time values may be selected as the elapsed operational time value.
FIG. 8 depicts the detection modules 38 , 44 and 46 and the counter 40 as components of the controller 24 . It will be appreciated that in other embodiments, any or all of these components may be in provided in circuitry which is separate from the controller 24 .
The foregoing description of preferred embodiments for this invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled. | A programmable hearing aid apparatus includes a processor, digital-to-analog converter, audio output section, memory and a counter. The processor executes one or more available programs, which are stored in the memory, for processing digital audio signals. The digital-to -analog converter generates output analog audio signals based on the digital audio signals. The audio output section receives and amplifies the output analog audio signals, generates audible sound based thereon and provides the audible sound to a person using the hearing aid. The counter generates a counter value based on a count of events that are indicative of the application of power to or the removal of power from the apparatus. After a predetermined elapsed time, the processor determines which of the available programs has been used most in processing the digital audio signals, where the determination of elapsed time is based at least in part on the counter value. The counter may count occurrences of events indicative of the removal and replacement of the battery, such as a number of times a contact switch on a battery compartment door is electrically opened or closed. The counter may also count a number of times the voltage across the battery increases by a substantial amount indicating that a weak battery has been replaced with a fresh battery. The counter may also count a number of times an on/off switch is operated by a user. | 7 |
BACKGROUND--FIELD OF INVENTION
This invention relates to the digital processing of audio signals, specifically to the use of a suitable interconnection of linear-phase filters and sample rate decimators to perform the function of audio equalization.
BACKGROUND--DESCRIPTION OF PRIOR ART
The history of audio equalization goes all the way back to the invention of the telephone and to Maxwell's analysis which led to the creation of the telephone loading coil and perhaps earlier. Formal study of the theory of audio filters grew out of the development of electrical filters for radio frequency transmission and reception. Modern equalizers find their place every day in the fields of analog tape and disc recording, in pre-emphasis/de-emphasis filters in broadcasting, and in audio recording, mixing and reproduction, among other uses.
The first equalizers used in the commercial broadcast and film industries evolved from similar devices used in other industries such as telephone transmission. These early devices used passive components in connections called RLC networks (named after the letters electronic engineers use to represent resistance, inductance and capacitance, respectively) which was generally followed by an amplifier to "make up" the inevitable loss. As inexpensive operational amplifiers became available in the early 1970's, this "passive" technology was gradually replaced with so-called "active" filters which incorporated the amplifier stage as an integral part of the filter. The primary advantage of the active filter was that designs were discovered which did not use any actual inductors at all resulting in a substantial cost savings and somewhat less susceptibility to hum pickup from stray AC fields.
At about the same time, researchers working in various fields of weapons systems and telecommunications started to develop the theory of digital signal processing, which involved the organization of so-called sampled-data systems and the development of a whole new mathematical idiom, the z-transform, to describe their operation. It wasn't until about 1985 that the first integrated circuit implementation of a DSP device became commercially available and began to popularize the technology.
There are many ways to build a filter using DSP technology. but most of them can be classified into one of three categories: infinite-impulse response (also known as IIR), finite-impulse response (FIR), and transform-based approaches (based upon converting the signal to frequency domain and back, usually using a Fast Fourier Transform process and its inverse, or an equivalent method). Each of these methods has its strengths and drawbacks when applied to audio applications. IIR filters definitely use the fewest DSP processing cycles per filter section, but the resultant filters are non-minimum phase; in addition, when the ratio of the sampling rate selected to the nominal "corner" frequency of the filter becomes high, as happens when IIR filters are designed for the lower audio frequencies, their requirement for extremely precise coefficients generally requires that they be implemented on a 24-bit rather than a 16-bit processor, at somewhat higher cost. The FIR filters are both linear-phase and minimum-phase, so they have far fewer adverse effects on the signal; in addition, the architecture of most modern DSP's is generally optimized for efficient computation of FIR filters, so that a single "tap" or computation point of an FIR filter generally takes either one or two clock cycles whereas each point in an IIR filter may take from 20 to 50 cyles. However, FIR filters also have problems at the lower audio frequencies; since the number of points to be computed increases as the inverse of the FIR "corner" frequency, if a designer tries to implement these filters at the system sample rate (as they generally do), several thousand processing cycles per sample are necessary to calculate each filter at the lower frequencies, but current technology only supports several hundred per sample per processor (at the standard sampling rates of 44.1 or 48 kilohertz), so that these filters are seldom used in real-time applications. Fast-Fourier Transforms require a high degree of frequency precision and hence a high number of sample points per transform to avoid audible distortion, so they take even more cycles than FIR filters; their much-ballyhooed "efficiency" really only takes effect when when the need is for a linear filter resolution in absolute bandwidth, but the need in an audio equalizer is for resolution as a constant percentage of bandwidth, so that the efficiency goes down dramatically for FFT-based approaches in constant-percentage-bandwidth (constant "Q") applications.
To cite an example of the lack of efficiency in direct calculation of FIR filters, if we use the DFDP tool and ask it to generate a Parks-McClellan bandpass filter at 25 hertz when the sample rate is 44.1 kilohertz, it will tell us that well over 4000 filter taps must be used. Thus, just implementing the lowest octave on a graphic equalizer will require that over 12.000 taps be calculated for a one-third-octace filter!! Since the number of taps required goes down in rough proportion as the frequency increases, it would take approximately double this number or 24,000 multiply-accumulate instructions to be implemented in a 22.6 microsecond interval, which works out to well over 1000 MIPS! As you can see, there is no currently available digital filter bank mechanism which is linear-phase, does all one-third octave bands and requires less than, say, 600 MIPS (or roughly 20 MIPS per band "averaged", although as you can see this kind of "average" means almost nothing on a per-band basis).
OBJECTS AND ADVANTAGES
The design of a digital audio equalizer should allow the convenient adjustment of the amplitude of each individual passband with minimal interaction on other bands. It should also take into account the fact that a given audio program may in fact pass through several generations of equalizers, so that phase shift through any one particular passband should be ideally no worse than that of an absolute time delay, or degeneration of the signal may in fact be audible through multiple stages of equalization. It should also be possible to realize such a design with an amount of digital signal processing power, or its logic-based equivalent, that is small enough to be affordable, portable and reliable enough for field application.
In accordance with the description presented herein, other objectives of this invention will become apparent when the description and drawings are reviewed.
DRAWING FIGURES
FIG. 1 shows the conceptual signal flow diagram of a typical single-channel equalizer which is implemented using the techniques described herein to calculate the equalizer algorithm efficiently and thus avoid the problem of rate inversion.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The method of direct calculation for FIR filters requires too much computing power to be commercially viable using currently available programmable digital signal processors, DSP or DFDP, as a means of implementing real-time audio equalizers. The basic reason for this inefficiency lies in the fact that FIR filters are only optimally efficient when their corner frequencies are above a certain fraction of the sampling frequency; below that, most of the samples are wasted in performing a redundant anti-aliasing function which could have been accomplished more efficiently in a separate filter stage designed for such a purpose. For example, in the design of a fairly efficient filter, one filter stage could be used as an anti-aliasing filter. The DFDP products currently available including supporting software design tools may be used to formulate such a filter. For the audio frequency range of interest, a filter with a low pass filter having a sample rate of 44.1 kilohertz, pass band at 5 kilohertz, pass band ripple of 0.02 and stop band ripple of 0.00002 using the Parks-McClellan algorithm and a length of 32 taps could be realized. With this structure the maximum stop band leakage is 88.3 decibels down when allowing for 16-bit coefficient rounding. However, the corner frequency of the filter is no lower than approximately 11% of the sampling rate. If the corner frequency is reduced to 5% of the sampling rate or lower, there is a significant reduction in filter efficiency. This loss of efficiency, or phenomenon, may be described as a rate inversion, meaning that the attempt to operate the filter at such a lowered frequency has severely compromised efficiency as was discussed in the low frequency band pass filter herein.
A significant cause of the FIR filter inefficiency in use appears to be the ignoring or non-use of multiple outputs produced at each sample rate of a staged filter. The traditional design approach for filters in which the throughput must be the same as the input sample rate is to specify filter stages with down sampling or dividing by a factor of N, that is, anti-alias filtering to a new sample rate followed by decimation by N, to provide a single output resultant frequency and not N outputs. This is usually considered sufficient as all other possible outputs at the same sample rate carry the same information except for phase with the implication the phase information is virtually insignificant for the filter process. Historically, this seems to have occurred as most sampling applications have been for the intended purpose of reducing bulk storage requirements or real-time bandwidth demands for communication links. As part of such processing, in a later stage the samples must be up sampled or multiplied for the individual filter outputs using output reconstruction filters for each rate with a filter order, or number of taps, approximately equal to the orders of the filters which would be required by direct calculation. This process thus loses most of the efficiency of the calculation method.
Referring to FIG. 1, a new filter design for use of the sampling process multiple output elements at each stage of filtering and decimation is illustrated. For the preferred embodiment frequency band of interest for an audio equalizer the decimation factor has been illustrated as uniformly 2 at each filter stage and both outputs, a subset of the more general N outputs if a factor of N were used, are used for the subsequent filter stage or rank. This structure at each rank wherein the sample rate is changed after the first or 0 rank therefore resembles the polyphase filters which currently exist in filter technology. It is important to note that in implementing such a filter in a digital signal processor (1), the filter is realized in a hardware unit for which software or firmware is developed to structure the processor for executing the digital filter signal processing function. To implement this filter, an input analog multiplexer (10) and a two channel input signal analog-to-digital converter (12) are linked and condition the input signal. Likewise an output signal digital-to-analog converter (22) is illustrated.
In such a programmable digital signal processor (1) structure the busses illustrated as vertical lines at each rank or stage are implemented as a specific 32-word buffer (16), so that the collection of all buffers (16) of a given sampling rate are known as its rank (17) where a particular rank (17) which is n consists of 2 n buffers (17) and the sampling rate of any particular rank (17) which is n times 2 n is always equal to the output aggregate sample rate. However, in practice, identical coefficients are used in all filter stages rather than requiring calculation of the filter stage at the higher reference rate and using every nth coefficient in each channel. This reduces the amount of coefficient storage required and avoids the possibility of creating audible phase artifacts or discontinuities when transitioning from the prior stage of decimation to the next stage of decimation, although in practice this might only prove to be audible for decimation factors considerably greater than 2.
The preferred embodiment implementation in FIG. 1 with a 10 stage rank appears to require a matrix of 1023 buffers (16) which all must be kept updated in real time. This would be true for such a filter implementation in the current art wherein only one decimation output (15) is used and the decimation results must be reconstructed or interpellated as for example described in the article by Paul H. Kraght, Journal Audio Engineering Society, Vol. 40, No. 5, 1992, May. However, upon closer inspection it can be seen that the filter as a whole may be kept current if only one buffer (16) out of each rank (17) is updated at each sample time or period since there is only one new sample point generated per rank (17) in each sample period. Stated differently, each new sample must generate its own path through the matrix and there is only one correct next path through the matrix which will keep each filter stage updated exactly when required by each sample period.
Referring to the 10 stage illustrated filter, each filter stage has a number of low pass filters (19) equivalent to the prior stage decimator (14) count which is incremented as a binary factor in rank order. The binary factor being a function of the use of both decimator outputs (15) for all decimators (14) in each stage. Therefore, the initial rank 0 or input has a single low pass filter (19) and decimator (14) together with band pass filters (18) for the intermediate frequencies with programmed or digital potentiometers (20) to balance output. Similarly rank 1 has two low pass filters (19) and decimators (14) for processing in alternating sample periods the two decimator outputs (15) received from two circular memory buss buffers (16). This processing proceeds to increase in an ordered binaural progression in similar manner at each stage. The final product of this filter process is complete sample frequency information for each of the frequency bands of interest for equalizer control without the need to use subsequent filter stages to interpolate to the input frequency sample. This process by eliminating the need for interpolation thereby reduces the computational requirements for a signal processor by up to an order of magnitude.
In order to best realize this computational efficiency, the digital signal processor (1) must maintain information relative to the sample period times or periods to calculate the next filter update. This does not require keeping information on each stage or rank and each filter which would be a significant memory and computational burden. Determining the sample period stage can be maintained based on the total number of ranks (17) of the filter and whether the intermediate buffers (16) are implemented as linear or circular buffers.
For the preferred embodiment illustrated, there are 9 decimation filter ranks in addition to the filters operating at the input sample rate. The intermediate data is stored in circular buffers (16). The ten pointers can be computed from a special register called the system state vector by using simple Boolean algebra and by proper selection of the particular memory scheme the next value for the state vector is calculated by simply incrementing by 1. If the buffers (16) were linear instead of circular, there would be no buffer start and buffer end registers, the masks would look slightly different and the increment would of course be by 32 instead of 1. One implementation of the state vector would include memory structured in order to force the buffers into the upper 32 kilowords of a 64 kiloword memory area, in order to use exclusively off-chip and contiguous memory as would be required on a Texas Instruments TMS320C51 or similar processor. Another example of a currently known processor for implementing the process is the Motorola DSP 56362.
While the invention has been particularly shown and described with respect to the illustrated and preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. | A digital multi-bandpass audio equalizer which is comprised of an analog multiplexer (10), a two-channel analog-to-digital converter (12), a digital-to-analog converter (22), and a digital signal processor which is programmed to provide an arrangement consisting of combined anti-alias filters/sample rate decimators (14), memory buffers at various sample rates (16), bandpass filters (18), and "virtual" potentiometers (20), structured in such a way that the digital filter elements which are operated at low frequencies are implemented at correspondingly low sample rates in order to minimize the amount of calculation involved, maximize computational efficiency and avoid the phenomenon of "rate inversion". | 7 |
This is a division of Ser. No. 524,656 filed 8/19/83 and now U.S. Pat. No. 4,578,924.
BACKGROUND OF THE INVENTION
This invention relates to a bag closing and sealing machine in general and in particular to a new and novel bag closing machine for use on a stepped end adhesively sealed bag.
It is known in the prior art to provide various types of bag closing and sealing machines having the necessary feeding and creasing sections in combination with folding and heating sections and compression sections for closing and sealing a stepped end adhesively sealed bag known in the art as a pinch style bag. Bags of this type are typified by the multi-wall bags containing charcoal, ice and other heavy materials which may be purchased at various retail and commercial outlets throughout the country.
A typical bag closing and sealing machine for stepped end bags is shown in the U.S. Pat. No. 3,381,448, issued on May 7, 1968, to R. H. Ayres et al. This patent teaches an in-line elongated machine having the before-mentioned sections fixedly attached to a machine frame for the ultimate purpose of closing and sealing the pinch style bags.
This type machine, while successful in the market place, has had problems with jams occurring in the machine due to tracking problems of the various compression belts and due to the uncontrollable nature of folding of paper under high-speed bag operations. Due to these particular problems, jam-ups can occur in the machine shown in the patent and the removal of jammed bags requires a partial dismantling of portions of the machine to free the jammed bags. This condition may take as long as one to one-and-a-half hours depending upon the total complexity of the jammed condition and where it lies within the various sections of the machine.
Since paper bags will at times refuse to fold in the predetermined manner precisely as designed by the machines, it can be seen by referring to the figures of the drawings in the Ayres et al patent, how a jam in the various sections could result in a lengthy amount of down time to release the jam since the easy removal of a jammed bag has not been taken into consideration in design of the Ayres machine.
SUMMARY OF THE INVENTION
In order to overcome the before described problems in prior art bag closing and sealing machines, there has been provided by the subject invention a new and novel pinch bag closing and sealing machine which has new and unusual break away features that allow a jammed bag to be quickly and easily removed from within the machine. The applicant's new and novel machine is designed with a plurality of elongated sections that are attached to the frame of the machine. One section is fixedly attached to the frame of the machine while the other section is either pivotably mounted on the frame or slidably mounted as a modification of the preferred embodiment. The various before described sections used in a bag closing and sealing machine are then mounted partly on the fixed section and partly on the pivotable or slidable section to coact together during normal operation of the machine.
During a jam of a bag in the machine, a quick-release feature allows the pivotable section to pivot downwardly and out of the operative position so that the jam can be quickly removed from the machine. In the alternative, the non-fixed section can slide away from the fixed section thereby allowing the jammed bag to be quickly and easily removed from the area where the jam occurred.
Other important features added to the applicant's new and novel machine include an improved compression section wherein a poly V belt and pulley system are used to minimize belt walking which is one of the causes of jams in a bag sealing machine. The use of the poly V belt compression section in combination with the split axial machine design thereby reduces jams to a minimum and when a jam does occur, reduces the time taken for removal of the jam from the before described one to one-and-a-half hour down to approximately five minutes. In addition the applicant's new and novel design permits the various belts used in the invention to be changed with approximately five minutes down time being required for the change-over.
Accordingly it is an object and advantage of the invention to provide a new and novel bag closing and sealing machine which reduces jams within the machine by the use of an axial break away construction of the machine.
Another object and advantage of the invention is to provide a new and novel bag closing and sealing machine in which a portion of the components of the machine may be quickly and easily pivoted, moved or slid away from the remaining portion of the machine to allow the jammed condition in the machine to be eliminated quickly and with minimal down time.
A further object and advantage of the invention is to provide a new and novel bag closing and sealing machine in which a jammed bag condition is minimized by the use of poly V belts and pulleys in critical sections of the machine.
Another object and advantage of the invention is to provide a new and novel bag closing and sealing machine in which belt change-over time is greatly reduced due to the particular construction of the machine with its axial split section hereinbefore described.
Still yet another object and advantage of the invention is to provide a new and novel bag closing and sealing machine and method for quickly and easily releasing a jammed step end bag wherein a larger quantity of bags is able to be run through the machine before a jam occurs thereby resulting in more profit to the machine owner.
These and other objects and advantages of the invention will become apparent from a review of the drawings and from a reading of the hereinafter description of the preferred embodiment which has been given by way of illustration only.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the applicant's new and novel bag closing and sealing machine;
FIG. 2 is a top view, taken along line 2--2 of FIG. 1 of the applicant's machine;
FIG. 3 is an end view, taken along line 3--3 of FIG. 1 showing the applicant's machine;
FIG. 4 is a sectional view, taken along line 4--4 of FIG. 2 showing the one elongated section pivotably repositioned to a nonoperative position;
FIG. 5 is a top schematic view of the applicant's complete machine showing the three prime sections of the machine and showing in greater detail how the bag is creased and folded through the machine;
FIG. 6 is a side view taken along line 6--6 of FIG. 5 showing in greater detail the folding section of the machine;
FIGS. 7, 8, 9, 10, 11, 12 and 13 are cross-sectional views taken through lines 7--7 to 13--13 of FIG. 6 showing how the folding progresses in the folding section;
FIG. 14 is a cross-sectional view, taken along lines 14--14 of FIG. 1, showing in detail the mounting of the heating section on the applicant's machine;
FIG. 15 is a plan view, taken along lines 15--15 of FIG. 14 showing in greater detail the top of the heating section;
FIG. 16 is a cross-sectional view, taken along lines 16--16 of FIG. 14 showing in detail the inside of the applicant's heating section;
FIG. 17 is a sectional view, taken along line 4--4 of FIG. 2 showing a modification of the preferred embodiment wherein the one elongated section is designed to slide outwardly away from the fixed elongated section instead of pivoting downwardly and outwardly;
FIG. 18 is an end view, taken along line 18--18 of FIG. 17 showing the mounting of the modification of FIG. 17;
FIG. 19 is an enlarged sectional view, taken along lines 19--19 of FIG. 1 showing in detail the poly V pulley and belt used on the applicant's invention; and
FIG. 20 is an enlarged sectional view, taken along lines 20--20 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in general and in particular to FIG. 1 of the drawing there is shown the applicant's new and novel bag closing and sealing machine generally by the numeral 10 which comprises a frame 12 and a pivotable elongated section 14 pivotably attached to the frame 12 and in juxtaposition to a fixed elongated section 16 shown more clearly in FIG. 2 of the drawings. The fixed elongated section 16 is fixedly attached to the frame. The pivotable elongated section 14 in combination with the fixed elongated section 16 contains the three prime portions of the applicant's machine which are a feeding and creasing section shown generally by the numeral 18, a folding and heating section shown generally by the numeral 20 and a compression section shown generally by the numeral 22.
The three sections before named are positioned so that a bag entering the feeding and creasing section 18 will travel in the direction shown by the arrow 24 progressing downstream to the folding and heating section and finally through the compression section where the stepped ends of the bag are adhesively sealed together whereupon the bag is then removed from the applicant's new and novel bag closing and sealing machine.
Referring now to FIG. 5 of the drawing there is shown a top schematic view of the applicant's complete machine showing the before mentioned three prime sections of the machine and showing in greater detail how the bag passing through the machine would be creased and folded prior to entering the compression section 22. The feeding and creasing section would comprise a pair of pulleys 26 and 28 which would be attached for rotation to the fixed elongated section 16 and would be driven by a belt 29. The feeding and creasing section would also comprise a pair of pulleys 30 and 32 which would be attached for rotation to the pivotable elongated section 14 and would be driven by a belt 33 of the type known in the art. A stepped end bag entering the machine would enter in the direction shown by the arrow 34 and would pass between the two portions of the feeding and creasing section as shown in FIG. 5 of the drawing. Should a jam occur in this section, then the set of pulleys 30 and 32 along with the V belt 33 could be pivoted out of position as will be described more fully hereinafter to release the jam from this section.
After the stepped bag passes through the feeding and creasing section 18, it will pass through the folding and heating section 20 to be folded downwardly to its sealed position prior to entering the compression section. The folding and heating section 20 comprises an elongated folding rail 36 which is fixedly attached to the fixed elongated section 16 and contains a heating portion 38 which is fixedly attached to the pivotable elongated section 14.
When constructed in this manner, as a stepped end bag passes through the folding and heating section 20, should a jam occur in this section, then the heating portion 38 of the section is able to be pivoted downwardly and outwardly as will be described more clearly hereinafter to easily release the jammed bag from this section. For purposes of clarity in the schematic view shown in FIG. 5 of the drawings, only one unit of a two-heating-portioned unit 38 has been shown in solid lines in FIG. 5. A second heating portion may be used downstream of the first heating portion 38 should it be desirable to split the heating portion in two pieces. When constructed thusly the second heating portion would also be attached for rotation to the pivotable elongated section 14 and would be designed to be able to swing downwardly and outwardly away from the folding rail 36 thereby allowing a jammed bag in the folding and heating portion 20 to be quickly removed from that portion.
For purposes of clarity then FIG. 5 has been shown with the folding and heating portion 20 having at least one heating portion 38 and possibly a second heating portion 39 as desired while FIGS. 7 through 13 have been shown as if the folding and heating section 20 were constructed with a single elongated heating portion formed as a single unit encompassing heating portions 38 and heating portions 39. When the stepped end bag passes through the folding and heating section 20 it can be seen how a heating section 38 or 39 will then function as the folding rail 36 folds the bag 40 downwardly to its folded position. The heating portions 38 and 39 would have heated air passing through the central section 42 which would pass through the top portion of the heating portions 38 and 39 to be expelled out through openings in the top portion. In FIG. 7 the heated air would be numbered 44 as it passes through the openings in the top of the heating portions 38 and 39 and would serve to melt the hot-melt adhesive previously formed on stepped end bags in the bag construction operation.
As the folding rail 36 then folds the bag ends downwardly, the heating continues throughout the heating portions 38 and 39 until the bag ends are finally closed and ultimately sealed as the bag 40 passes through the compression section 22. FIGS. 7 through 13 are cross-sectional views taken along lines 7--7 through lines 13--13 of the folding rail section showing in schematic form the folding and heating to activate the stepped end bags hot-melt adhesive prior to the entering of the compression section.
The heating portions 38 and 39, constructed thusly, form hot air manifolds which are heated by separate heating elements 46 shown in greater detail in FIG. 1 of the drawing. The heating elements are capable of being raised to approximately a 1900° F. temperature by known electrical means and would circulate a plant air source 48 coming into the heating element 46 at approximately 6 PSI at a rate of 10 cubic feet per minute. The plant air 48 enters in through the air inlet 50 and through the heating element 46 where it passes through the air outlet 52 into the heating portion 38 or heating portion 39 as constructed. The normal outlet air temperature for a pinched-style bag coming through the heating portion or 38 at 44 would be in the range of 325° to 500° F. in order to activate the hot-melt adhesive on the stepped end of the pinched-style bag.
Returning now to FIG. 5 of the drawing there will be described the compression section 22 of the applicant's new and novel bag closing and sealing machine. A pair of poly V belt pulleys 54 and 56 are attached for rotation to the fixed elongated section 16 and are rotated by means of a poly V belt 57. A second set of poly V belt pulleys 58 and 60 are mounted for rotation to the pivotable elongated section 14 and are rotated by the poly V belt 61. As a bag 40 passes through the compression section 22, should a jam-up occur in this section, then the entire compression section may be quickly pivoted downwardly and outwardly as will be described more fully hereinafter to quickly and easily release the jam from that section.
When the applicant's bag machine is constructed, the pivotable elongated section 14 may be constructed in a one-piece construction so that all three prime sections 18, 20 and 22 may be pivoted as a unit as taught in the preferred embodiment. It is within the spirit and scope of the invention that the pivotable elongated section 14 may also be constructed in a one, two or three-piece construction so that each prime section 18, 20 or 22 may be pivoted downwardly and outwardly as desired either individually or in combination with other sections. Modifications may be made in the preferred embodiment as shown to accomplish this within the spirit and scope of the invention should it be desired by the purchaser of the machine to have individual pivotable sections.
In the drawings shown in this application, a single pivotable elongated section is shown and it is within the abilities of the designer to redesign the machine to provide for a split two or three-piece pivotable section having the teachings of the applicant'invention before him.
It is also within the spirit and scope of the invention that the applicant's pivotable elongated section 14 could be designed to slide or move away from the fixed elongated section 16 as will be shown in more detail hereinafter to allow the applicant's new and novel bag closing and sealing machine to function in a similar manner to the pivotable version. Should a movable version be constructed, then it is also within the spirit and scope of the invention that the movable portion could be constructed in a one, two or three-piece slidable section so that the prime sections 18, 20 and 22 can either be moved away from the fixed elongated section 16 singly or individually as desired by a purchaser of the machine.
Referring now to drawing FIGS. 2, 3 and 4 there will be shown in more detail how the applicant's pivotable elongated section 14 is positioned in juxtaposition to the fixed elongated section 16 and how the two sections function together during normal operation of the machine and during occurrence of a jam in any section of the unit.
In FIG. 2 it can be seen how a pair of break-open cylinders 62 and 64 may be positioned on or over the pivotable elongated section 14 and have elongated pins 66 and 68 connected to the cylinders designed for engagement with an extension of the frame 12. The frame extension is shown more clearly in FIGS. 3 and 4 of the drawing which comprises a pair of cantilevered arms 70, 72, 74 and 76 which would be welded to the vertical portion of the frame 12 to extend above both the pivotable elongated section 14 and the fixed elongated section 16. As has been before mentioned the fixed elongated section 16 would be fixedly attached to the cantilevered arms 70, 72, 74 and 76 by welding or bolting or some other suitable attaching means. The break-open cylinders 62 and 64 may also be positioned on the fixed elongated section 16 to function in a like manner. The break-open cylinders may also be positioned as shown in FIG. 2 and may be cantilevered off of a horizontal member (not shown) which is in turn fixed to the fixed elongated section 16.
By referring to FIGS. 3 and 4 there can be seen how the pivotable elongated section 14 is designed to pivot around a pair of pins 78 and 80 which are positioned through a series of holes formed in the ends 82 and 84 of the cantilevered arms 70, 72, 74 and 76. When positioned thusly it can be seen that the pivotable elongated section 14 is able to swing downwardly and outwardly as shown by the arrow direction 86 in order to be able to release a jammed bag from between the pivotable elongated section 14 and the fixed elongated section 16. The swinging of the pivotable elongated section 14 downwardly and outwardly in the direction by the arrow 86 may be by gravity, by a hydraulic or pneumatic cylinder and may also be by an electric motor within the spirit and scope of the invention.
It can be seen in comparing FIGS. 3 and FIGS. 4 that the normal operating position of the pivotable elongated section 14 is as shown in FIG. 3 with the dotted line representing how the pivotable elongated section 14 would be swung outwardly to relieve a jammed condition in the machine. FIG. 4 also shows the swinging of the pivotable elongated section 14 with the entire section shown in solid lines as it would be released downwardly and outwardly to free a jammed bag condition.
By referring to FIGS. 2, 3 and 4 it can then be seen how the activation of the break-open cylinders 62 and 64 by means of an activating valve 90 will permit the cylinders to retract withdrawing the elongated pins 66 and 68 from the holes 92 formed in the cantilevered arms 70, 72, 74 and 76 thereby permitting the entire pivotable elongated section 14 to swing downwardly and outwardly by gravity or other means as has been before described.
A control box 94 is mounted for easy access to the frame 12. The drive motor 96 with its attached motor drive 98 is mounted on one of the upper legs 100 attached to the frame 12. A sliding leg 102 is attached to a lower horizontal frame not shown in the drawing which rests upon the floor below the applicant's bag sealing machine. By the use of the upper leg 100 and sliding leg 102 it can be seen how the entire structure may be raised vertically to adjust to a particular bag height and the bag line in which the machine is positioned. A cross-frame 104 is welded to the upper legs 100 to reinforce the upper leg portion of the applicant's machine.
Referring now to FIG. 14 of the drawing there is shown a cross-sectional view, taken along lines 14--14 of FIG. 1, showing in detail the mounting of the heating portion 38 on the applicant's machine. As has been before mentioned, the heating section is designed to be mounted on the pivotable elongated section 14 and is designed to be carried by the air outlet 52 which is connected to the heating element 46 as is shown in greater detail in FIG. 1 of the drawing. The air outlet 52 would be formed of a pipe or tube which would be welded at 106 on the end 108 of the heating portion 38. The heating element 46 would be mounted between an upper housing 110 and a lower housing 112 with the upper housing 110 being fixedly attached to a mounting plate 114 which would in turn be bolted at 116 to the pivotable elongated section 14.
When constructed thusly it can be seen how the pivotable elongated section 14 could be pivoted in the direction shown by the arrow 118 to the dashed position shown in FIG. 14 which would be the non-operative position from which a jammed bag could be released from the machine.
Referring now to FIG. 15 of the drawing there is shown a plan view, taken along lines 15--15 of FIG. 14 showing in greater detail the top of the heating portion 38. The heating portion 38 would be formed with a top plate 120 having a plurality of holes 122 formed therein at each of the locations marked with a "+" at 124 to indicate a hole 122. Through these holes would be forced the heated air 44 as shown in FIGS. 7-13 of the drawings to activitate the heat seal on the pinch-style bag passing through the applicant's machine.
Referring now to FIG. 16 of the drawings, there is shown a cross-sectional view, taken along lines 16--16 of FIG. 14 showing in greater detail the inside of the applicant's heating portion 38. The heating portion comprises a back plate 126 and a front plate 128 fixedly attached together by side plates 130 and 132. A plurality of baffle plates 134, 136, 138 and 140 are fixedly attached to a bottom plate 142. A top plate 144 is fixedly attached to the front plate 128 and the front plate 128A and contains an inlet hole 146 where the air inlet pipe 52 is welded in position as has been shown in FIG. 14 of the drawings.
From this it can be seen that the heated air 44 passes through the air outlet 52 in the direction shown by the arrow 148 in FIG. 14 and passes upwardly through the heating portion 38 through the outlet holes 122 shown in FIG. 15 of the drawing. The plurality of baffle plates 134, 136, 138 and 140 evenly distribute the heating air within the heating portion 38 so that it is uniformly released from the heating portion through the outlet holes 122.
Referring now to FIGS. 17 and 18 of the drawing there is shown in greater detail the modification of the preferred embodiment wherein the elongated section 14 may be formed so that the elongated section may be designed to be slidable away from the fixed elongated section 16 instead of being designed to be pivotable from that section. It can be seen in FIG. 17 how the fixed elongated section 16 and the pivotable elongated section 14 are positioned below a cantilevered arm 150 and 152 which have been welded to the frame 12 of the basic machine. An elongated slot 154 is positioned within the cantilevered arms 150 and 152 and is designed to carry a plurality of cam rollers 156 and 158 as shown in FIGS. 17 and 18.
A break-open cylinder 160 would be positioned as shown in FIG. 17 and would have a rod 162 connected to the rod end 164 and to the plurality of cam rollers 156 and 158. A shaft, not shown in the drawings, would also rotatably mount the cam rollers 156 and 158 so that they could slide upon the upturned ends 166 and 168 of the cantilevered arms 150 and 152.
In this manner it can be seen how upon a jammed condition in the applicant's machine, the break-open cylinders 160 would be activated with air, hydraulics or some other activating means to slide the pivotable elongated section 14 in the direction shown by the arrow 170 to the non-operational position as shown by the dashed lines in FIG. 17 of the drawing. It is within the spirit and scope of the invention that a plurality of break-open cylinders 160 could be used to slide the elongated section 14 should it be desirable to form the elongated section in a one-piece construction. If the elongated section were formed in three separate sections as has been before mentioned when referring to the preferred embodiment, then also a plurality of break-open cylinders would be utilized with at least one break-open cylinder on each portion of the sectionalized elongated section 14. It is also within the spirit and scope of the applicant's invention that the elongated section 14 may be formed to pivot to a non-operating position, to slide to a non-operating position and to be moved to a non-operating position by other means within the applicant's basic concept. The applicant is not to be limited to the exact manner of moving the pivotable elongated section 14 from the operating position to the non-operating position since the manner shown has been shown by way of illustration only.
Referring now to FIG. 19 of the drawing there is shown an enlarged sectional view, taken along lines 19--19 of FIG. 1 showing in detail the poly V pulley and belt construction used on the applicant's basic invention. The poly V belt pulleys 60 and 56 as well as the poly V belt pulleys 58 and 54 would be constructed as shown in FIG. 19 having a series of circumferentially spaced protrusions 172 formed on the pulley which match up with similarly sized voids 174 formed on the belts 57 and 61. When formed thusly, the belts 57 and 61 will track within the poly V belt pulley thereby preventing a bag passing through the machine from riding up on the belts or having the belts ride up on the pulley. It can also be seen in FIG. 19 of the drawing and FIGS. 1 and 5 of the drawing how the belt 33 and the belt 29 of the feeding section run the entire length of the applicant's machine and run around the pulleys 176 and 178 of the machine. The pulleys 176 and 178 are rotatably attached to the shafts 180 and 182. The shafts also carry the poly V pulleys 57 and 60. The shafts 180 and 182 are rotatably mounted in the bearings 188, 190, 184 and 186 as can be seen in FIG. 19 of the drawing.
For purposes of providing more pressure through the compression section 22 of the applicant's machine there are also provided poly V pressure pulleys 192, 194 and 196 mounted on the pivotable elongated section 14 as well as poly V pulleys 198, 200 and 202 mounted on the fixed elongated section 16. For purposes of clarity these are shown by dashed lines in FIG. 2 of the drawing and have been eliminated from FIG. 5 for the same reason.
FIG. 20 is a cross-sectional view taken along line 20--20 of FIG. 1 showing more detail on the mounting of the poly V pulleys 192, 194, 196, 198, 200 and 202. FIG. 20 shows the mounting of two of the pulleys and is taken through the adjacent pulleys 192 and 198. A pair of bearings 300 and 302 are mounted with the pulley 192 rotating thereon and are carried by the shaft 304. A pair of bearings 306 and 308 are also mounted with the pulley 198 rotating thereon and are carried by the shaft 310. The belts 29 and 33 ride in separate channels 312 and 314 mounted on the aluminum bars 316 and 318. The belts 29 and 33 run free on the opposite outside ends of the bars 316 and 318. The poly V belts 57 and 61 also run free on the opposite outside portions of their matching pulleys as shown better in FIG. 2.
From the foregoing it can be seen that there has been provided by the applicant's invention a new and novel bag closing and sealing machine which is designed to allow a separation at the actual center of the machine whenever a bag jam starts to occur. The separation may be of the entire one side of the bag machine or may be of the separate three sections of the bag machine which are the feeding and creasing section, the folding and heating section and the compression section. The separation may be activated by pivoting one, two or three of these sections and may be activated by sliding or moving one, two or three of these sections or by other means within the spirit and scope of the invention. The activation may be by means of an air cylinder, a hydraulic cylinder, an electric motor worm gear drive and also other means within the spirit and scope of the invention. It can be seen that other changes may be made in the applicant's machine and method without departing from the spirit and scope and the applicant is not to be limited to the exact manners shown in the application including the drawings which have been shown by way of illustration only.
The movable elongated section 14 can also be separated from the fixed elongated section 16 by the use of a worm gear operating mechanism of the type known in the art of worm gear movement. If constructed thusly, the turning of the worm gear to move the elongated section 14 could be mechanically controlled by a handle or by electric motor or other means within the spirit and scope of the invention. The elongated section 14 could also be slid by hand away from the fixed elongated section 16 after being unlocked from its operating position by a locking device. Other variations are possible within the spirit and scope of my invention. | A bag closing and sealing machine is disclosed for closing and sealing stepped end adhesively sealed type bags. The machine is designed to allow a separation at the axial center line of the machine whenever a bag jam starts to occur. By providing for axial separation, lengthy and costly dismantling of the machine to clear a jam-up is eliminated. The machine comprises three primary sections which are a feeding and creasing section, a folding and heating section and a compression section. The various sections are fixedly attached partly to a fixed elongated frame and partly to a pivotable elongated frame in the preferred embodiment. In a modification of the preferred embodiment, the pivotable elongated frame is replaced by a slidable elongated frame to function in a similar manner. A method of quickly and easily releasing a jammed stepped end bag from the machine is also disclosed. The pivotable elongated frame may be also designed to slide or move away from the fixed elongated frame by various means such as by electric motor drive, worm gear drive, hydraulic or air cylinder drive, hand cranking or by manual pulling among other ways within the spirit and scope of the invention. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CN2007/070393, filed Jul. 31, 2007, which claims priority to Chinese Patent Application No. 200610104208.3, filed Aug. 1, 2006 and Chinese Patent Application No. 200610153985.7, filed Sep. 15, 2006, all of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the technical field of communications, and particularly to an access network system, an access device in the system, and an address resolution protocol proxy and an IP bridging forwarding method thereof.
BACKGROUND OF THE INVENTION
[0003] The Digital Subscriber Line (DSL) network architecture is evolving from the Point to Point Protocol over Asynchronous Transfer Mode (PPP over ATM) to an enabling architecture of IP Quality of Service (QoS) based on Ethernet aggregation and connection. Under this background, a general reference architecture of the DSL is illustrated in FIG. 1 .
[0004] In the DSL reference architecture as illustrated in FIG. 1 , T is a reference point between a User Equipment (UE) and a Residential Gateway (RG) in a Customer Premises Network (CPN); U is a reference point between an RG and an Access Node (AN, i.e., DSL Access Multiplexer, DSLAM); in an Access Network (AN), there is an Aggregation Network between the AN (i.e., the DSLAM) and a Broadband Remote Access Server (BRAS) or a Broadband Network Gateway (BNG); V is an Ethernet Aggregation reference point between the AN (i.e., DSLAM) and the BRAS/BNG in the access network; A 10 is a reference point between the access network and a Service Provider (SP). The reference point A 10 may connect an Application Service Provider (ASP) to a Network Service Provider (NSP) including an access network, or connect the NSP to an access network in a visiting area in the scenario of roaming. The CPN is connected with the access network in a DSL access technique. For a Passive Optical Network (PON), the AN is an Optical Line Termination (OLT), and the CPN is connected with the access network in a PON access technique, etc.
[0005] At present, as illustrated in the DSL reference architecture of FIG. 1 , there is no reference point between ANs (i.e., DSLAMs) of the DSL network, and only star or tree networking can be adopted between the ANs (i.e., DSLAMs) and the BRAS/BNG of the DSL network. In the procedure of attempting to achieve the present invention, the inventor finds that the DSL reference architecture of FIG. 1 has at least the following disadvantages:
[0006] 1. For providing multicast services such as IP TV, the BRAS/BNG and the aggregation network should support multicast copy, thereby the existing DSL network should be modified. A schematic diagram of a multicast and broadcast model of a DSL network with star or tree networking is illustrated in FIG. 2 . Because star or tree networking paths (BNG->AN 1 , BNG->AN 2 , BNG->AN 3 , . . . , BNG->ANn) are adopted to transmit multicast or broadcast data streams, which results in a large amount of multicast or broadcast traffic in the DSL network.
[0007] 2. If a network single point of failure occurs in the connection between an AN and the BRAS/BNG as illustrated in FIG. 3 , the AN disconnects with the BRAS/BNG, and all users connected to the AN are provided with service.
[0008] 3. The traffic between users covered by different ANs should be transferred by the BRAS/BNG. A path for communication between users covered by different ANs is illustrated in FIG. 4 . The path is long with a long delay. The BRAS/BNG becomes a bottleneck for the communication and can not meet the requirements of future VoIP and Peer-to-Peer communications.
SUMMARY OF THE INVENTION
[0009] The present invention is to provide an access network system, an access device in the system, an address resolution protocol proxy and IP bridging forwarding method thereof. The present invention may be applied to a digital subscriber line network and a passive optical network, so as to reduce multicast or broadcast traffic in such a network, to reduce the delay, and to shorten the communication path, thereby preventing the BRAS/BNG from becoming a bottleneck for the communication.
[0010] An object of the present invention is achieved by the following technical solutions.
[0011] An access network system includes one or more access network edge nodes, each of which connected with one or more access nodes; and the one or more access nodes, adapted to enable a user terminal to access an access network, where a reference point is introduced between the access nodes to support connections between the access nodes.
[0012] An access device in an access network system, includes (1) a user-side port module, adapted to communicate with a user terminal; (2) a network-side port module, adapted to communicate with an access network edge node; (3) an access device-side port module, adapted to communicate with another access device in the access network system; (4) an address resolution protocol proxy module, which is connected to the user-side port module, the network-side port module and the access device-side port module, adapted to proxy-forward an address resolution protocol message; and (5) an IP bridging forwarding module, which is connected to the user-side port module, the network-side port module and the access device-side port module, adapted to forward a packet.
[0013] An address resolution protocol proxy method in an access network system, applied to address resolution protocol proxy between a first access node and a second access node of multiple access nodes, includes (1) forwarding, by the first access node, an address resolution protocol request from an address resolution protocol requestor to the second access node, and sending, by the first access node, the MAC address of the first access node in a first address resolution protocol in response to the address resolution protocol request; and (2) sending, by the second access node, the MAC address of the second access node in a second address resolution protocol in response to another address resolution protocol request from the first access node.
[0014] An IP bridging forwarding method in an access network system, applied to IP bridging forwarding between a first access node and a second access node of multiple access nodes, includes (1) creating an IP bridging forwarding table in the first access node and the second access node; (2) searching, by at least one of the first access node and the second access node, in the IP bridging forwarding table according to an IP address in a received packet to obtain at least one of IP session information and IP service connection information; (3) updating, by the at least one of the first access node and the second access node, MAC frame header information in the received packet according to the at least one of IP session information and IP service connection information; and (4) forwarding, by the first access node, the updated packet to the second access node, or forwarding, by the second access node, the updated packet to the first access node.
[0015] The present invention reduces multicast or broadcast traffic in the network, reduces the delay and shortens the communication path, thereby preventing the BRAS/BNG from becoming a bottleneck for communications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The drawings provide further understanding of the present invention, and are incorporated in the present application to constitute a part of the present application. The drawings together with the description show embodiments of the present invention to make clear of the principle of the present invention.
[0017] FIG. 1 is a schematic diagram of a multimedia broadcast and multicast service function layer;
[0018] FIG. 2 is a schematic diagram of a multicast and broadcast model with star or tree networking;
[0019] FIG. 3 is a schematic diagram of a network single point of failure;
[0020] FIG. 4 is a schematic diagram of a path of the communication between users;
[0021] FIG. 5 a is a structure diagram of an access network system according to the present invention;
[0022] FIG. 5 b is a structure diagram of an access device in an access network system according to the present invention;
[0023] FIG. 6 is a flowchart of an address resolution protocol proxy method utilized in an access network system according to the present invention;
[0024] FIG. 7 is a flowchart of an IP bridging forwarding method utilized in an access network system according to the present invention;
[0025] FIG. 8 a is another flowchart of an IP bridging forwarding method utilized in an access network system according to the present invention;
[0026] FIG. 8 b is another flowchart of an IP bridging forwarding method utilized in an access network system according to the present invention;
[0027] FIG. 9 a is a further flowchart of an IP bridging forwarding method utilized in an access network system according to the present invention;
[0028] FIG. 9 b is a further flowchart of an IP bridging forwarding method utilized in an access network system according to the present invention;
[0029] FIG. 10 is a schematic diagram of a single-edge access network reference architecture according to the present invention;
[0030] FIG. 11 is a schematic diagram of a multi-edge access network reference architecture according to the present invention;
[0031] FIG. 12 a, FIG. 12 b, FIG. 12 c and FIG. 12 d are schematic diagrams of chain or ring networking multicast and broadcast models according to the present invention;
[0032] FIG. 13 a and FIG. 13 b are schematic diagrams of chain networking multicast and broadcast failure models according to the present invention;
[0033] FIG. 14 a, FIG. 14 b, FIG. 14 c and FIG. 14 d are schematic diagrams of dual-ring networking multicast and broadcast failure models according to the present invention;
[0034] FIG. 15 is a schematic diagram of a networking unicast failure model 1 according to the present invention;
[0035] FIG. 16 is a schematic diagram of a networking unicast failure model 2 according to the present invention;
[0036] FIG. 17 a and FIG. 17 b are schematic diagrams of paths for communications between users;
[0037] FIG. 18 is a schematic diagram of IP bridging in an access network reference architecture according to the present invention;
[0038] FIG. 19 is a schematic diagram of an ARP proxy in an access network reference architecture according to the present invention; and
[0039] FIG. 20 is a schematic diagram of IP bridging in reference architecture according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The present invention is described in further detail with reference to the attached drawings and embodiments as follows.
[0041] FIG. 5 a is a structure diagram of an access network system according to the present invention. The access network system includes: one or more access network edge nodes, and one or more access nodes. Each access network edge node is connected with one or more access nodes. The access node is adapted to enable user terminals to access the access network. Reference points are introduced between the access nodes for supporting connections between the access nodes.
[0042] The above access network edge node includes at least one of a broadband remote access server and a broadband network gateway.
[0043] The networking between the access network edge nodes and the access nodes may be implemented in at least one of the following modes: star, tree, chain, and ring. The access nodes may be connected with each other in a ring mode.
[0044] In the case of unicast service, the networking between the access network edge nodes and the access nodes is implemented in a star or tree mode. In the case of multicast or broadcast service, the networking between the access network edge nodes and the access nodes is implemented in a chain, ring or dual-ring mode.
[0045] The access node may be at least one of the following: an access node supporting layer-3 routing, an access node supporting layer-2, an access node supporting IP bridging, and an access node supporting address resolution protocol proxy.
[0046] In normal cases, user data is transmitted between the access nodes directly, to support the communication between users in different access nodes. If a single point of failure occurs between an access node and an access network edge node, the access node is connected with the access network edge node via another access node. If a failure occurs between an access node and another access node, the access node is connected with another access node to transmit data via a reverse ring path between the access node and a third access node.
[0047] FIG. 5 b is a block diagram of an access device of an access network system according to the present invention. As illustrated in FIG. 5 b, the access device of the access network system according to the present invention includes: a user-side port module 502 , adapted to communicate with a user terminal; a network-side port module 504 , adapted to communicate with an access network edge node; an access device-side port module 506 , adapted to communicate with one or more other access devices in the access network system; an address resolution protocol proxy module 508 , which is connected to the user-side port module, the network-side port module and the access device-side port module, adapted to proxy-forward an address resolution protocol message; and an IP bridging forwarding module 510 , which is connected to the user-side port module, the network-side port module and the access device-side port module, adapted to forward a packet. The packet is data including an IP header and a MAC frame.
[0048] The above access network edge node includes at least one of the following: a broadband remote access server and a broadband network gateway. If the access device receives an address resolution protocol request, the address resolution protocol proxy module in the access device forwards the address resolution protocol request to a next access device, and forwards the MAC address of the access device in an address resolution protocol in response to the address resolution protocol request.
[0049] The above IP bridging forwarding module stores an IP bridging forwarding table. IP session information in the above IP bridging forwarding table includes: a user-side physical port, a user IP address, and a user MAC address. IP service connection information in the IP bridging forwarding table includes: the MAC address of an access network edge node. The IP service connection information further includes at least one of the following: a network-side physical port and a virtual local area network identifier.
[0050] In the IP bridging forwarding table of the access device, the item of a user MAC address of the access device is the MAC address of a previous access device or user terminal connected with the user-side physical port.
[0051] In the IP bridging forwarding table of the access device, the item of the MAC address of the access network edge node is the MAC address of a next access device or access network edge node connected with the network-side physical port.
[0052] If the access device receives a packet from a user terminal/an access network edge node/another access device, the access device searches in the IP bridging forwarding table according to the IP address in the packet to obtain IP session information and/or IP service connection information, updates MAC frame header information in the received packet according to the IP session information and/or the IP service connection information, and forwards the updated packet to a next access device.
[0053] FIG. 6 is a flowchart of an address resolution protocol proxy method utilized in the above access network system according to the present invention. FIG. 6 illustrates an address resolution protocol proxy method between an access node 1 and an access node 2 of multiple access nodes. If packet information is transmitted from a user terminal to a network edge access node in an uplink direction, the method includes the following steps.
[0054] In step S 602 , the access node 1 forwards a first address resolution protocol request from an address resolution protocol requestor to the access node 2 , and sends the MAC address of the access node 1 in an address resolution protocol in response to the address resolution protocol request.
[0055] In step S 604 , the access node 2 sends its MAC address in an address resolution protocol in response to the address resolution protocol request from the access node 1 .
[0056] FIG. 7 is a flowchart of an IP bridging forwarding method utilized in the above access network system according to the present invention. The IP bridging forwarding method between an access node 1 and an access node 2 of multiple access nodes according to the present invention includes the following steps.
[0057] In step S 702 , an IP bridging forwarding table is created in the access node 1 and the access node 2 .
[0058] In step S 704 , the access node 1 and/or the access node 2 searches in the IP bridging forwarding table according to an IP address in a received packet to obtain IP session information and/or IP service connection information.
[0059] In step S 706 , MAC frame header information in the received packet is updated according to the IP session information and/or the IP service connection information.
[0060] In step S 708 , the access node 1 forwards the updated packet to the access node 2 , or the access node 2 forwards the updated packet to the access node 1 .
[0061] Particularly, the access node obtains the MAC address of a user device and address information obtained by an ARP proxy via a Dynamic Host Configuration Protocol (DHCP) message initiated from the user device, so as to create the IP bridging forwarding table.
[0062] The IP session information in the IP bridging forwarding table includes: a user-side physical port, a user IP address, and a user MAC address.
[0063] In the IP bridging forwarding table of the access node 2 , the item of the user MAC address corresponding to the user-side physical port connected with the access node 1 is the MAC address of the access node 1 .
[0064] The IP service connection information in the IP bridging forwarding table includes: the MAC address of an access network edge node. The IP service connection information further includes at least one of the following: a network-side physical port and a virtual local area network identifier.
[0065] In the IP bridging forwarding table of the access node 1 , the item of the MAC address of the access network edge node corresponding to the network-side physical port connected with the access node 2 is the MAC address of the access node 2 directed to the access network edge node.
[0066] As illustrated in FIG. 8 a, if a packet is sent from a user terminal to an access network edge node (in an uplink direction) and an access node 1 forwards the packet to an access node 2 , an IP bridging forwarding method may include the following steps.
[0067] In step S 802 a, the access node 1 searches in an IP bridging forwarding table according to a source IP address in the packet from the user terminal, to obtain a network-side physical port, a virtual local area network identifier and the MAC address of the access network edge node.
[0068] In step S 804 a, the access node 1 updates a destination MAC address in the packet with the MAC address of the access node 2 , updates a source MAC address in the packet with the MAC address of the access node 1 , and adds or updates the virtual local area network identifier information in the packet.
[0069] In step S 806 a, the access node 1 forwards the updated packet to the access node 2 via the obtained network-side physical port.
[0070] As illustrated in FIG. 8 b, if a packet is sent from a user terminal to an access network edge node (in an uplink direction) and an access node 2 forwards the packet to the access network edge node, an IP bridging forwarding method may include the following steps.
[0071] In step S 802 b, the access node 2 searches in an IP bridging forwarding table according to a source IP address in the packet from the user terminal, to obtain a network-side physical port, a virtual local area network identifier and a MAC address of the access network edge node.
[0072] In step S 804 b, the access node 2 updates a destination MAC address in the packet with the MAC address of the access network edge node, updates a source MAC address in the packet with the MAC address of the access node 2 , and adds or updates the virtual local area network identifier information in the packet.
[0073] In step S 806 b, the access node 2 forwards the updated packet to the access network edge node via the obtained network-side physical port.
[0074] As illustrated in FIG. 9 a, if a packet is sent from an access network edge node to a user terminal (in an downlink direction) and an access node 2 forwards the packet to the access node 1 , an IP bridging forwarding method may include the following steps.
[0075] In step S 902 a, the access node 2 searches in an IP bridging forwarding table according to a destination IP address in the packet from a network-side physical port, to obtain a user-side physical port and a user MAC address.
[0076] In step S 904 a, the access node 2 updates a destination MAC address in the packet with the MAC address of the access node 1 , and updates a source MAC address in the packet with the MAC address of the access node 2 .
[0077] In step S 906 a, the access node 2 forwards the updated packet from the obtained user-side physical port to the access node 1 .
[0078] As illustrated in FIG. 9 b, if a packet is sent from an access network edge node to a user terminal (in an downlink direction) and an access node 1 forwards the packet to the user terminal, an IP bridging forwarding method may include the following steps.
[0079] In step S 902 b, the access node 1 searches in an IP bridging forwarding table according to a destination IP address in the packet from a network-side physical port, to obtain a user-side physical port and a user MAC address.
[0080] In step S 904 b, the access node 1 updates a destination MAC address in the packet with the user MAC address, and updates a source MAC address in the packet with the MAC address of the access node 1 .
[0081] In step S 906 b, the access node 1 forwards the updated packet to the user terminal via the obtained user-side physical port.
[0082] As can be seen from the above, a reference point R is introduced between ANs according to the present invention, so that the ANs can connect with each other to constitute a new single-edge or multi-edge access network reference architecture.
[0083] For multicast or broadcast service, the present invention may adopt a chain, ring or dual-ring networking path (BNG->AN 1 ->AN 2 ->AN 3 . . . ->ANn) to transmit broadcast or multicast data streams. For unicast service, the present invention may adopt a star or tree networking path to transmit unicast data streams. The BRAS/BNG and the aggregation network do not need to support multicast copy, and multicast or broadcast service can be provided only if the ANs are connected with each other, thereby reducing multicast or broadcast traffic greatly in the network.
[0084] If a single point of failure occurs in a connection between an AN and the BRAS/BNG, the connection can be switched to another AN link because the ANs can be connected with each other, thereby implementing a multi-homing function.
[0085] The present invention can meet the requirements of future VoIP and Peer-to-Peer communications. The traffic between users covered by different ANs may be transferred at the data plane not via the BRAS/BNG but via interfaces between the ANs. Therefore, the delay can be reduced and the communication path can be shortened evidently, to prevent the BRAS/BNG from becoming a bottleneck for communications.
[0086] An AN supporting layer-3 routing or an AN supporting IP bridging may be adopted in the present invention.
[0087] Technical solutions of the present invention are described with reference to the attached drawings as follows.
[0088] According to the present invention, a reference point R is introduced between ANs, so that the ANs can connect with each other. A single-edge access network reference architecture is illustrated in FIG. 10 . In addition, a multi-edge access network reference architecture is illustrated in FIG. 11 , in which a reference point R is introduced similarly.
[0089] In the access network architecture according to the present invention, star or tree and chain or ring hybrid networking may be adopted between an AN (i.e., DSLAM or OLT) of the DSL network and the BRAS/BNG, as illustrated in FIG. 12 . As illustrated in FIG. 12( a ) and FIG. 12( b ), a chain, ring or dual-ring networking path (BNG->AN 1 ->AN 2 ->AN 3 . . . ->ANn) may be adopted to transmit multicast or broadcast data streams, and a star or tree networking path may be adopted to transmit unicast data streams. As illustrated in FIG. 12( c ) and FIG. 12( d ), a ring networking path may be adopted to transmit multicast or broadcast data streams. The BRAS/BNG and the aggregation network do not need to support multicast copy, and multicast or broadcast service can be provided only if the ANs are connected with each other, thereby reducing multicast or broadcast traffic greatly in the network.
[0090] For multicast or broadcast service, assuming that if a single point of failure occurs on the BNG->AN 1 path as illustrated in FIG. 13( a ) and FIG. 13( b ), a chain networking path (BNG->AN 2 ->AN 3 . . . ->Ann; AN 2 ->AN 1 ) according to the present invention may be adopted to transmit multicast or broadcast data streams, here AN 2 is a multicast copy point; or as illustrated in FIG. 14( a ) and FIG. 14( b ), a second ring networking path of a dual-ring (BNG->ANn-> . . . AN 3 ->AN 2 ->An 1 ) may be adopted to transmit multicast or broadcast data streams; if a single point of failure occurs on the AN 1 ->AN 2 path as illustrated in FIG. 14( c ) and FIG. 14( d ), an inverse networking path of a ring (BNG->AN 1 ->ANn . . . AN 3 ->AN 2 ) may be adopted to transmit multicast or broadcast data streams. This shows the flexibility of chain or ring networking which supports multicast or broadcast service.
[0091] For unicast service, if a single point of failure occurs on the BNG->AN 1 path as illustrated in FIG. 15 , a networking path (BNG->AN 2 ->AN 1 ) according to the present invention may be adopted to transmit unicast data streams to implement a multi-homing function; or as illustrated in FIG. 16 , a networking path (NSP 2 ->BNG->AN 2 ->AN 1 ) according to the present invention may be adopted to transmit unicast data streams to implement a multi-homing function.
[0092] For meeting the requirements of future VoIP and Peer-to-Peer communications, for the traffic between users covered by different ANs, control signaling may still passes through the BRAS/BNG, but packet data on the data plane may be transferred not via the BRAS/BNG but via interfaces between the ANs directly as illustrated in FIG. 17( a ) and FIG. 17( b ). Therefore, the delay can be reduced and the communication path can be shortened evidently, to prevent the BRAS/BNG from becoming a bottleneck of communications.
[0093] In the unicast models in FIG. 15 and FIG. 16 , ANs supporting layer-3 routing or ANs supporting IP bridging may be adopted. As illustrated in FIG. 18 , assuming that the RG is a layer-2 bridging device, the IP address of UE 1 is IPa, the IP address of BNG/ER is IPr (a default gateway of a user), the IP address of a party peer to the UE (the Server in FIG. 18 ) is IPx, the MAC address of UE 1 is MAC 1 , the MAC address of AN 1 is MAC 2 , the MAC address of AN 2 is MAC 3 , the MAC address of BNG/BRAS/ER is MAC 4 ; the interworking port n of AN 1 is connected with the interworking port m of AN 2 , the AN 1 user port connected with the UE 1 is port x, the AN 1 is connected uplink via the port t, the AN 2 is connected uplink via the port r. If a single point of failure occurs on the BNG->AN 1 path, the connection will be switched to the BNG->AN 2 path.
[0094] The AN provides an Address Resolution Protocol Proxy (ARP Proxy) function. As illustrated in FIG. 19 , the AN 1 forwards an ARP request (ARP-req) from the AN 1 user port x to the AN 2 , and the AN 2 responds an ARP reply (ARP-reply) including the MAC address MAC 3 of AN 2 to the AN 1 ; the AN 2 forwards an ARP request (ARP-req) from the port r to the AN 1 , the AN 2 responds an ARP reply (ARP-reply) including the MAC address MAC 3 of AN 2 via the port r, and the AN 1 responds an ARP reply (ARP-reply) including the MAC address MAC 2 of AN 1 to the AN 2 .
[0095] The AN may obtain the MAC address of a user device and address information obtained by an ARP proxy via a Dynamic Host Configuration Protocol (DHCP) message initiated by the user device, so as to create an IP bridging forwarding table. Therefore, an IP bridging forwarding table based on IP session in the AN, as illustrated in tables 1 to 2 Particularly, the IP session is represented by a use-side physical port, a user IP address and a user MAC address; an IP service connection is represented by a network-side physical port, a virtual local area network identifiers S-VLAN and the BNG MAC address.
[0000] The S-VLAN may be configured statically or dynamically. In table 1, the MAC address corresponding to the IP address of a user connected with the interworking port m of AN 2 is not the user's MAC address, but the MAC address of the AN covering the user. In table 2, the MAC address corresponding to the IP address of a user connected with the interworking port n of AN 1 is not the MAC address of the BNG which the user belongs to, but the MAC address of the AN connected with the interworking port n of AN 1 .
[0000]
TABLE 1
IP bridging forwarding table of AN2
IP session
IP service connection
User-side
BNG
physical
User IP
User MAC
Network-side
MAC
port
address
address
physical port
S-VLAN
address
m
IPa
MAC2
r
1011
MAC4
(MAC
address of a
next AN)
y
. . .
. . .
r
1011
MAC4
[0000]
TABLE 2
IP bridging forwarding table of AN1
IP session
User-side
User
IP service connection
physical
User IP
MAC
Network-side
BNG MAC
port
address
address
physical port
S-VLAN
address
. . .
. . .
. . .
t
1011
MAC4
x
IPa
MAC1
n
0111
MAC3
(MAC
address of a
next AN)
[0096] The IP bridging procedure in the access network reference architecture according to the present invention is illustrated in FIG. 20 , in which the parentheses denote a packet of a certain layer. Particularly, the packet including IP addresses is an IP packet, and the packet including MAC addresses is a MAC frame.
In the Uplink Direction:
[0097] For a packet (including a MAC frame and an IP packet header) from a user-side port of the AN 1 , the AN 1 searches in an IP bridging forwarding table of the AN 1 (i.e., table 2) according to a source IP address of the IP packet (IPa in this example) to obtain a network-side physical port (port n in this example), S-VLAN (0111 in this example) and a BNG MAC address (MAC 3 in this example), modifies a destination address of the MAC frame of the packet to MAC 3 , modifies the source address to the MAC address of AN 1 , MAC 2 , and adds or modifies the S-VLAN in the MAC frame to ‘0111’; then forwards the packet to the AN 2 via the port n, thereby accomplishing IP bridging at this node. Alternatively, the port n is bound with a specific S-VLAN value in a default manner, e.g., ‘0111’. The IP service connection is represented only by the S-VLAN and the BNG MAC address. If the S-VLAN ‘0111’ is obtained by search, it is default that the packet is forwarded by the port n; if another S-VLAN is obtained by search, it is default that the packet is forwarded by the port t.
[0098] For a packet (including a MAC frame and an IP packet header) from a user-side port of the AN 2 , the AN 2 searches in an IP bridging forwarding table of the AN 2 (i.e., table 1) according to a source IP address of the IP packet (IPa in this example) to obtain a network-side physical port (port r in this example), S-VLAN (1011 in this example) and a BNG MAC address (MAC 4 in this example), modifies a destination address of the MAC frame of the packet to MAC 4 , modifies the source address to the MAC address of AN 2 , MAC 3 , and adds or modifies the S-VLAN in the MAC frame to ‘1011’; then forwards the packet to the BNG via the port r, thereby accomplishing IP bridging at this node.
In the Downlink Direction:
[0099] For a packet (including a MAC frame and an IP packet header) from a network-side port of the AN 2 , the AN 2 searches in an IP bridging forwarding table of the AN 2 (i.e., table 1) according to a destination IP address of the IP packet (IPa in this example) to obtain a user-side physical port (port m in this example) and a user MAC address (MAC 2 in this example), modifies a destination address of the MAC frame of the packet to MAC 2 , modifies a source address of the MAC frame to the MAC address of AN 2 , MAC 3 , and forwards the packet to the AN 1 via the port m, thereby accomplishing IP bridging at this node.
[0100] For a packet (including a MAC frame and an IP packet header) from a network-side port of the AN 1 , the AN 1 searches in an IP bridging forwarding table of the AN 1 (i.e., table 2) according to a destination IP address of the IP packet (IPa in this example) to obtain a user-side physical port (port x in this example) and a user MAC address (MAC 1 in this example), modifies a destination address of the MAC frame of the packet to MAC 1 , modifies a source address of the MAC frame to the MAC address of AN 1 , MAC 2 , and forwards the packet to the user via the port x, thereby accomplishing IP bridging at this node.
[0101] The above description is for the embodiments of the present invention, which shall not limit the scope of the present invention. It is apparent to those skilled in the art that various variations and substitutes may be easily made to the present invention within the scope of the present invention as defined in the appended claims. | An access network system, an address resolution protocol proxy method and an IP bridging forwarding method for the access network system are disclosed. The access network system comprises: one or more access network edge nodes that connect to one or more access nodes; one or more access nodes that connect to user terminals to the access network, and a reference point that is introduced between two adjacent access nodes for the access nodes interconnection. With this system, the multi-cast or broadcast flow in the network can be reduced and the communication delay and path can also be decreased. Therefore the communication bottleneck brought by BRAS/BNG can be avoided. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] Disclosed herein is subject matter that is entitled to the filing date of U.S. Provisional Application No. 60/779,656, filed 6 Mar. 2006.
FIELD OF THE INVENTION
[0002] The following invention pertains to exercise equipment, and more specifically to treadmill apparatus which enables the user to exercise the upper body while simultaneously reducing the level of exercise exertion of the lower body.
BACKGROUND OF THE INVENTION
[0003] The apparatus herein described enables a treadmill user to grasp a rigid member, such as a bar, and exert a force in a generally downward direction, thus exercising bicep, clavicle, deltoid, pectoralis, brachialis, brachioradialis, and other body muscles. The rigid member (bar) may be restrained to some degree in the transverse and longitudinal directions with respect to the treadmill, wherein the longitudinal direction corresponds with the front/rear, and transverse corresponds to a side to side direction.
SUMMARY OF THE INVENTION
[0004] One of the benefits in utilizing the present invention while simultaneously walking on a treadmill is that the user would be able to have a direct influence on, or effect a change, in the portions of the body that the user wishes to exercise. Furthermore, the user is enabled to reduce spine weight and fatigue at the lower body while the upper body is anxious to exert itself. In such a manner, the constraints imposed at the handle bar allow, for example, the user to grasp said bar, perform a “lat pull-down”, or some form of a lat pull-down, with or without the handle bar(s) being in motion. The dynamics thus available enable the user to perform a wide variety of exercises new in the art. Additionally, an inherent advantage, particularly when walking on a moving surface, is that while grasping the hand grips the user has an instant non visual sense of the user's relative position upon the treadmill belted region, primarily with regard to lateral restraints imposed on said bar. Also to be noted is that the right and left portions of the body may be exercised dependently or independently. For example, a user with an injured foot, ankle, or leg would nevertheless be able to exercise on a treadmill because of the potential to reduce weight at all, or at a specific region, of the lower body, whereas with prior art such a user had only limited types of exercise equipment suitable to use when in such a physical condition.
[0005] The prior art does not disclose the novel features of the invention disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a first embodiment shown with a user and a typical treadmill.
[0007] FIG. 2 is another perspective view of the first embodiment shown with a user and a typical treadmill.
[0008] FIG. 3 is another perspective view of the first embodiment, however the user and the treadmill is omitted. The reader will note that the present invention may be used without a treadmill.
[0009] FIG. 4 is a side view of the first embodiment shown with a user and a typical treadmill.
[0010] FIG. 5 is a top view of the first embodiment shown with a user and a typical treadmill.
[0011] FIG. 6 is a back view of the first embodiment shown without a user, and without a typical treadmill.
[0012] FIG. 7 is a zoomed fragmentary perspective view of a portion of the mechanism of the first embodiment.
[0013] FIG. 8 is a perspective view of a second embodiment shown with a user and a typical treadmill.
[0014] FIG. 9 is another perspective view of the second embodiment shown with a typical treadmill.
[0015] FIG. 10 is a perspective view of a third embodiment shown with a user and a typical treadmill.
[0016] FIG. 11 is another perspective view of the third embodiment shown with a typical treadmill.
[0017] FIG. 12 is another perspective view of the third embodiment shown with a user and a typical treadmill.
[0018] FIG. 13 is a perspective view of a fourth third embodiment shown with a user and a typical treadmill.
[0019] FIG. 14 is another perspective view of the fourth embodiment shown with a user and a typical treadmill.
[0020] FIG. 15 is a perspective view of a fifth embodiment.
[0021] FIG. 16 is a perspective view of a sixth embodiment.
[0022] FIG. 17 is a perspective view of a seventh embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to the figures, and first to the first embodiment shown in FIG. 1 through FIG. 7 , the apparatus is shown being used in conjunction with treadmill 50 . Right and left frame portions 1 10 of this first embodiment may be adjusted to accommodate a wide range of treadmill widths available on the market today. Specifically, this embodiment is designed to accommodate treadmills that range in widths from 30-44 inches wide (W 100 shown in FIG. 3 ).
[0024] While walking on the treadmill, the operable interface with the user occurs at handgrips which are normally biased up or alternatively fixedly secured, such that the user may reach up to head level or above, and subsequently grasp and pull either of the hand grips and exert downward force at the handgrip in a manner which in some respects may provide for the exercise activity known as lat pull-downs. However, because of the optional independent, right versus left action possible, and furthermore because motion may also be initiated at the hand grips themselves, the analogy of “lat pull-down” form of exercise is not entirely accurate. More will be discussed about this later.
[0025] Continuing with FIG. 1 , handgrips 170 are secured to handle bar 160 , and upon loosening knob 159 , the handle bar 171 will telescope in or out of handle bar receiver tube 150 when making adjustments to accommodate the different sizes of users and/or longitudinal dimensions of treadmills. Handle bar receiver tube 150 is secured to socket 160 , wherein socket 160 is rotatably connected to the machine frame stanchion 180 about axis D 100 at bearing pairs 165 and 166 , and wherein socket 160 is connected to resistance element(s) of this embodiment. In order to accommodate different heights of users, or alternatively to define a particular form of exercise, an adjustment of circumferential nature is provided between said handle bar receiver tube 150 and said socket 160 . In order to facilitate such adjustment, threaded bolt having knob 158 may be loosened, followed by lifting spring 163 ( FIG. 7 ) loaded pin 155 radially outward, adjusting handle bar receiver tube 150 by moving hand grip in a circumferential direction relative to axis D 100 , allowing spring loaded pin 155 to bias radially inward and lock said receiver tube 150 to said socket 160 , and then finally tightening knob 158 . Socket 160 has internal splines, or in this instance, a female square receiver tube which cooperates with a smaller male square tube of rocker 140 in a telescoping manner while the exercise machine is set up and adjusted to accommodate different treadmill widths. Tightening of hex bolts 169 fixes the machine width constant. Rocker 140 is rigidly connected to said male square tube as a weldment, or other means, such that transmission of force from the user may be transmitted to the resistance element, or in this instance, weight member 120 .
[0026] In this embodiment, intermediate between said rocker 140 and said weight member 120 is connector member 130 . An upper distal end of connector member 130 is rotatably connected to rocker 140 about axis C 100 ; and a lower distal end of connector member 130 is rotatably connected to weight member 120 about axis B 100 . Weight member 120 is rotatably connected to the machine frame 110 about axis A 100 , wherein weight member 120 is normally down at rest against stop pad 122 . Shocks are optional and in this embodiment allow controlled ascent of the handlebars. This speed of ascent of the handgrips 170 may be constant velocity damper control or force dependent damper control. Continuing now, a lower end of shock 125 is rotatably connected to the machine frame 110 at axis F 100 , and an upper end of shock 122 is rotatably connected to said weight member 120 at axis E 100 . Generally, the weight member will seldom be required to have an angular range of motion beyond 40 degrees, which corresponds coincidentally to approximately 40 inches of hand grip 170 travel. Typically, 10 inches or so of hand grip 170 motion perhaps is all that is most commonly desirable. Continuing now, the transverse distance between right and left weight member 120 is determined when the machine is set up and the frame 110 width is established. In addition to the telescopic relationship which exists for this purpose between socket 160 and rocker 140 , telescopic elements 112 and 182 also exist to permit adjustment of the machine frame width.
[0027] While exercising in the independent mode, interesting forms of exercise are possible of an asymmetrical nature. Additionally, while exercising in the dependent mode, completely different forms of exercise are possible, including those which involve the user lifting one's self off of the treadmill belted surface. In order to switch to dependent mode, the user aligns both right and left female square receiver tubes 162 and 161 respectively, of sockets 160 , and inserts synchronization lock key 195 . In this embodiment, the weight load may be modified by changing the weight stack 115 . The amount of weight present at each side of the machine corresponds approximately to a one to one ratio (1:1) with the upward resistive force present at the hand grips 170 . For example, if 200 pounds are installed in each weight basket, a 400 pound user could perform a lat pull-down without the weight member 120 being lifted. Continuing now, when changing individual weight plates, retaining pins 117 and 118 may be withdrawn and reinserted in this process. If the user intends to use the full range of motion, employment of the retaining pins is suggested, if however the user only intends to use approximately 10 inches of hand grip motion, then the retaining pins 117 and 118 are not necessary. Other variations in weight load securement may be suitable and in some instances preferable. Also to be considered is to provide means to limit the range of motion of the hand grips 170 upon contact with un-illustrated stops and the like. In this regard, the range of motion of the hand grips 170 may be reduced to zero.
[0028] Directing attention now to the second embodiment shown in FIG. 8 and FIG. 9 , the mechanism is shown situated proximate treadmill 50 and having a central weight load 215 which exerts resistance to a dependent form of hand grip 270 motion. Handle bar 270 is adjusted telescopically relative to handle bar receiving member 250 , wherein handle bar 250 is rotatably secured to machine frame 210 about axis A 200 . Rocker 251 is rigidly connected to handle bar 250 . Pulleys 220 are rotatably connected to the machine frame 210 about axes B 200 and C 200 . A first end of cable 216 is connected to said weight load 215 , and a second end of said cable 216 is connected to a lower distal end of said rocker 251 at connection 217 . Intermediate said cable 216 ends said cable 216 is routed around said pulleys 220 . Adjustment of handle bar 250 relative to rocker 251 is accomplished upon removal, adjustment, and subsequent insertion of pin 234 into holes 233 of holey yoke 230 , wherein said pin 234 engages both said handle bar 250 and said holey yoke 230 .
[0029] Referring now to the third embodiment shown in FIG. 10 , FIG. 11 , and FIG. 12 , a mechanism is shown which allows the user to alter the position of the handle bar 360 pivot axis B 300 . Frame 310 rigidly secures stanchion 312 , wherein adjustable support member 340 may be pivoted about axis A 300 , and subsequently locked in place with unillustrated elements. Resistance to motion of hand grips 370 is provided by torsion springs 376 . The magnitude of the resisting torsion spring 376 may be adjusted as desired by using a spanner wrench, for example, at spring hub 372 , and locking said hub with hex nut 374 . In order to accommodate different treadmills 50 and/or different user leverage against said torsion spring 376 , handle bar 360 may be telescoped in or out of handle bar receiver member 350 upon loosening, adjusting, and subsequently tightening lock bolt 359 . Referring specifically to FIG. 10 , the handgrips are generally constrained to travel vertically. Referring to FIG. 11 , the handgrips are constrained to travel both longitudinally and vertically. Referring to FIG. 12 , the adjustable support members 340 have been established in a non parallel relationship, and thus the hand grips 370 are independent and also able to move in distinct circumferential arcs when viewed from the machine side, thus exhibiting additional characteristics of asymmetrical operation.
[0030] Direction attention now to the fourth embodiment shown in FIG. 13 and FIG. 14 , treadmill 51 has display console secured at tubular member 52 . Stanchion 412 is rigidly secured to frame 410 . An upper portion of said stanchion 412 rigidly secures horizontal grab bar 471 and cross beam 460 . Sway bar 469 is pivotally secured to cross beam 460 about axis B 400 . Handle bar 470 is rotatably secured to sway bar 469 about axis A 400 . Typically, when the user grasps and manipulates handle bar 470 during treadmill activity, the dual axes of A 400 and B 400 perform in combination to simulate geometry which exhibits characteristics in which the user would sense the presence of qualities of caster. Caster is a design condition that serves to cause the handle bar 470 to want to track straight rearward as longitudinal rearward forces are exerted against said handle bar 470 . In the event this effect is desired to be enhanced such that downward vertical forces at the handle bar 470 also tend to cause transverse self centering of axis A 400 relative to the treadmill 51 belted walking surface, then an inclined kingpin may be introduced wherein either or both axes A 400 and B 400 are non vertical, and generally inclined upwardly and rearwardly. This aspect, as noted earlier, gives the user a sense of being centrally located on the treadmill belt, while still having the flexibility of performing a wide variety of upper body exercises. Additionally, having a vertical axis that cooperates with a central region of the handle bar 470 enables the user to change direction readily by initiating a 180 degree spin, and walk backward for example, while grasping said handle bar 470 , if it is desired to exercise a different combination of lower body muscles.
[0031] Directing attention now to a fifth embodiment shown FIG. 15 , frame 512 rigidly secures stanchion 514 . Vertical extension 513 may be adjusted in height and secured when using a combination of un-illustrated pin(s) and hole(s). Alternatively, a simple coil compression spring, a gas spring, or a spring damper 515 having a lower end connected at pin 531 and an upper end connected to pin 532 , may be employed such that vertical movement of vertical extension 513 is possible while being biased upwardly. Boom 511 is rigidly attached to vertical extension 513 . Handle bar 570 is rotatably connected to boom 511 about axis A 500 . Axis A 500 may be vertically orientated, or may be inclined upwardly and rearwardly in order to introduce the inherent advantages discussed earlier of a self centering handle bar 570 . Furthermore, the handle bar 570 may be optionally configured in a circuitous route such that the effect of an inclined axis A 500 is thereby amplified.
[0032] Referring now to the sixth embodiment shown in FIG. 16 , a collapsible treadmill apparatus is shown which may be readily stored into a low profile during periods of inactivity. Frame 612 rotatably secures side props 620 about axis A 600 . Upper distal ends of said side props 620 are rotatably connected to adjustable stanchion 645 at axis B 600 . The adjustable stanchion 645 has a lower distal boss 660 which engages any one of a plurality of angular slots 650 while establishing the preferred height of handle bar 670 . When collapsed for storage, said bosses 660 are disengaged from said slots 650 , and the stanchion 645 is collapsed parallel against frame 612 .
[0033] Referring finally now to a seventh embodiment shown in FIG. 17 , frame 712 rotatably secures a lower distal end of prop 720 about axis A 700 , and an upper distal end of prop 720 is rotatably secured to adjustable stanchion 745 about axis B 700 . When adjusting the handle bar 770 for height, rotation of knob 785 causes boss 760 to move fore and aft along linear race 790 . With the threaded means illustrated, a threaded swivel joint having an axis coincident with axis C 700 cooperates with said boss 760 and said linear race 790 while adjusting or collapsing the mechanism for operation or storage.
[0034] In conclusion, a few general comments are in order and may pertain to one or more embodiments of this invention:
[0035] 1 Portions of the machine, such as any pivot joint (or joint connected to the machine frame), and/or any cable pulley, may be moved as desired in any direction in order to allow the operator to alter the specific exercise.
[0036] 2 Remote control electric and/or mechanical actuators may be utilized such as solenoids, servo motors, and/or hydraulic and/or pneumatic components, elastic bands, or other means without departing from the spirit and scope of the invention. Furthermore, a user interface device may be mounted at the console, and a switch provided within reach of a person applying force against the handle bar. Additionally, the user may make the exercise arm strokes longer or shorter, at different resistance levels, simply by communicating with a circuit, or pushing a button or effecting a switch. In this instance, the hand grips or handle bar of this treadmill apparatus may exhibit programmable and/or interactive force and motion characteristics with the user.
[0037] 3 In the embodiments which provide movable hand grips or handle bars and wherein pivotal members are present, a remote flywheel may connected to such movable members for purpose of inertia by means of sprag or one-way clutches and the like, in order to provide a cyclic rhythm of the users arm motion. Alternatively, an electric motor may or may not be used in substitution to, or in conjunction with said movable members.
[0038] 4 The user may face any direction and may use this mechanism with or without a treadmill, or while on other categories of exercise equipment machines such as skiers or elliptical machines.
[0039] Thus, improved mechanisms are shown which provides the operator with motion and force characteristics new in the art. While preferred embodiments of these inventions have been shown and described, it will be apparent to those skilled in the art that changes and modifications can be made in these embodiments without departing from the principles and spirit of the invention. | A treadmill apparatus comprising a rigid member movably supported overhead of a user wherein the rigid member has guiding arrangement for guiding a handle of the rigid member through a path having a vertical component, and wherein said handle has a biasing arrangement for biasing the handle toward an upper end of the path. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 08/808,135, filed Feb. 28, 1997, now U.S. Pat. No. 5,864,281, which is a file wrapper continuation of application Ser. No. 08/257,586, filed Jun. 9, 1994, now abandoned. This application is also related to commonly assigned U.S. application Ser. No. 08/121,717, filed Sep. 15, 1993, by Siden, Thompson, Zhang and Fang now abandoned, to commonly assigned U.S. application Ser. No. 07/910,950, now abandoned, filed Jul. 9, 1992, by Graves, Zhang, Chandler, Chan and Fang, now abandoned, and the corresponding PCT Application US93/06480, filed Jul. 8, 1993, and to the commonly assigned U.S. application Ser. No. 08/242,916 filed by Zhang and Fang on May 16, 1994, now abandoned in favor of continuation application Ser. No. 08/710,925, filed Sep. 24, 1996, now U.S. Pat. No. 5,831,510. The entire disclosure of each of those US and PCT applications is incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices comprising conductive polymer elements, in particular electrical devices such as circuit protection devices in which current flows between two electrodes through a conductive polymer element.
2. Introduction to the Invention
It is well known to make compositions which comprise a polymeric component and, dispersed therein, electrically conductive particles. The type and concentration of the particles may be such that the composition is conductive under normal conditions, e.g. has a resistivity of less than 10 6 ohm-cm at 23° C., or is essentially insulating under normal conditions, e.g. has a resistivity of at least 10 9 ohm-cm at 23° C., but has a non linear, voltage-dependent resistivity such that the composition becomes conductive if subjected to a sufficiently high voltage stress. The term “conductive polymer” is used herein to describe all such compositions. When the polymeric component comprises a crystalline polymer, the composition will usually exhibit a sharp increase in resistivity over a relatively narrow temperature range just below the crystalline melting point of the polymer, and such compositions are described as PTC compositions, the abbreviation “PTC” meaning positive temperature coefficient. The size of the increase in resistivity is important in many uses of PTC compositions, and is often referred to as the “autotherm height” of the composition. PTC conductive polymers are particularly useful in circuit protection devices and self-regulating heaters. Conductive polymers can contain one or more polymers, one or more conductive fillers, and optionally one or more other ingredients such as inert fillers, stabilizers, and anti-tracking agents. Particularly useful results have been obtained through the use of carbon black as a conductive filler.
For details of known or proposed conductive polymers and devices containing them, reference may be made, for example, to the documents incorporated herein by reference in the Detailed Description of the Invention below.
When a melt-processed, sintered, or otherwise shaped conductive polymer element is to be divided into smaller pieces, this has in the past been achieved by shearing (also referred to as “dicing”) the conductive polymer element. For example, many circuit protection devices are made by shearing a laminate comprising two metal foils and a laminar PTC conductive polymer element sandwiched between the foils.
SUMMARY OF THE INVENTION
We have discovered that in many cases, important advantages can be obtained by dividing a conductive polymer mass into a plurality of parts by a process in which at least part of the division is effected by causing the conductive polymer element to break, along a desired path, without the introduction of any solid body into the conductive polymer element along that path. The resulting cohesive failure of the conductive polymer produces a surface (referred to herein as a “fractured” surface) which is distinctly different from that produced by a shearing process, which necessarily results in deformation of the conductive polymer by the cutting body. In order to control the path along which the conductive polymer element breaks, we prefer to provide one or more discontinuities which are present in one or more members secured to the conductive polymer, and/or in the conductive polymer itself, and whose presence causes the conductive polymer to fracture along desired paths which are related to the discontinuities.
The invention preferably makes use of assemblies in which a conductive polymer element is sandwiched between metal members having corresponding physical discontinuities in the form of channels. When such an assembly is bent in the regions of the channels, the conductive polymer element will fracture along paths which run between the corresponding channels in the metal members. However, the invention includes the use of other types of physical discontinuity and other kinds of discontinuity which will interact with a physical or other force to cause fracture of the conductive polymer along a desired path.
We have found the present invention to be particularly useful for the production of devices from a laminar assembly comprising a laminar PTC conductive polymer element sandwiched between metal foils. We have found that, such devices, especially when they are small (e.g. have an area of less than 0.05 inch 2 ), have a slightly higher resistance and a substantially higher autotherm height than similar devices produced by the conventional shearing process. The invention is particularly useful for the production of devices of the kind described in Ser. Nos. 08/121,717 and 08/242,916.
In one preferred aspect, the present invention provides a device comprising an element which
(a) is composed of a composition which comprises (i) a polymeric component and (ii), dispersed in the polymer, electrically conductive particles, and
(b) has at least one fractured surface.
A preferred embodiment of this aspect of this invention is a device which comprises
(1) a laminar conductive polymer element which
(a) is composed of a composition which comprises (i) the polymeric component and (ii) the electrically conductive particles in an amount such that the composition has a resistivity at 23° C. of less than 10 6 ohm-cm, and
(b) has a first principal face, a second principal face parallel to the first face, and at least one transverse face which runs between the first and second faces and at least a part of which has a fractured surface;
(2) a first laminar electrode which has (i) an inner face which contacts the first principal face of the conductive polymer element, and (ii) an outer face; and
(3) a second laminar electrode which has (i) an inner face which contacts the second principal face of the conductive polymer element, and (ii) an outer face.
In another preferred aspect, the present invention provides a method of making a device, which method comprises
(1) making an assembly which (a) comprises an element composed of a composition comprising (i) a polymeric component, and (ii), dispersed in the polymeric component, electrically conductive particles, and (b) has one or more discontinuities in or adjacent to the conductive polymer element; and
(2) separating the assembly into two or more parts by a treatment which causes cohesive failure of the conductive polymer element along a path which is related to the discontinuity.
A preferred embodiment of this aspect of the invention is a method wherein the assembly comprises
(A) a laminar conductive polymer element which
(a) is composed of a composition which comprises a polymeric component and, dispersed in the polymeric component, electrically conductive particles in an amount such that the composition has a resistivity at 23° C. of less than 10 6 ohm-cm, and
(b) has a first principal face and a second principal face parallel to the first face,
(B) a plurality of upper laminar conductive members, each of which has (a) an inner face which contacts the first principal face of the conductive polymer element and (b) an outer face, the upper conductive members defining, with intermediate portions of the conductive polymer element, a plurality of upper fracture channels, and
(C) a plurality of lower laminar conductive members, each of which has (a) an inner face which contacts the second principal face of the conductive polymer element, and (b) an outer face, the lower conductive members defining, with intermediate portions of the conductive polymer element, a plurality of lower fracture channels; and
wherein step (2) of the process comprises applying physical forces to the assembly which cause the conductive polymer element to fracture along a plurality of paths each of which runs between one of the upper fracture channels and one of the lower fracture channels.
In another preferred aspect, this invention provides an assembly which can be divided into a plurality of devices by method of the invention, and which comprises
(A) a laminar conductive polymer element which
(a) is composed of a composition which comprises a polymeric component and, dispersed in the polymeric component, electrically conductive particles, and
(b) has a first principal face and a second principal face parallel to the first face,
(B) a plurality of upper laminar conductive members, each of which has (a) an inner face which contacts the first principal face of the conductive polymer element and (b) an outer face, the upper conductive members defining, with intermediate portions of the conductive polymer element, a plurality of upper fracture channels, and
(C) a plurality of lower laminar conductive members, each of which has (a) an inner face which contacts the second principal face of the conductive polymer element, and (b) an outer face, the lower conductive members defining, with intermediate portions of the conductive polymer element, a plurality of lower fracture channels.
A BRIEF DESCRIPTION OF THE DRAWING
The invention is illustrated in the accompanying drawing, in which
FIG. 1 is a diagrammatic plan view, and FIGS. 2 and 3 are diagrammatic partial cross-sections, at right angles to each other, of an assembly of the invention which can be converted into devices of the invention by the method of the invention;
FIGS. 4-6 are diagrammatic partial cross-sections through assemblies of the invention in successive stages of a process for producing a device as described in Ser. No. 08/242,916 except that the edges thereof are fractured instead of sheared;
FIGS. 7-10 are diagrammatic cross-sections through devices of the invention; and
FIGS. 11-13 are diagrammatic plan views of assemblies of the invention showing different patterns of fracture channels which can be employed to make devices having different shapes.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described below chiefly by reference to PTC circuit protection devices which comprise a laminar PTC element composed of a PTC conductive polymer and two laminar electrodes secured directly to the PTC element, and to methods for producing such devices in which a laminar element having surface discontinuities is subjected to physical forces which bend the element so as to cause cohesive failure of the conductive polymer. It is to be understood, however, that the description is also applicable, insofar as the context permits, to other electrical devices containing conductive polymer elements and to other methods.
As described and claimed below, and as illustrated in the accompanying drawings, and as further described and illustrated in the documents incorporated herein by reference, the present invention can make use of a number of particular features. Where such a feature is disclosed in a particular context or as part of a particular combination, it can also be used in other contexts and in other combinations, including for example other combinations of two or more such features.
Conductive Polymers
Any conductive polymer can be used in this invention, providing it is present in the form of an element which can be subjected to physical and/or other forces which will cause the element to undergo the cohesive failure which results in a fractured surface. The more brittle the conductive polymer, the easier it is to obtain this result. We have obtained excellent results using conductive polymers containing high proportions of carbon black, e.g. at least 40% by weight of the composition. When the conductive polymer will not snap easily, a variety of expedients can be used to assist in achieving the desired result. For example, the composition can be reformulated to include ingredients which render it more brittle, or it can be shaped into the element in a different way. The lower the temperature, the more brittle the conductive polymer, and in some cases it may be desirable to chill the conductive polymer element to a temperature below ambient temperature before breaking it, e.g. by passing it through liquid nitrogen. Compositions in which the polymeric component consists essentially of one or more crystalline polymers can usually be fractured without difficulty at temperatures substantially below the crystalline melting point. If the polymeric component consists of, or contains substantial amounts of, an amorphous polymer, the element is preferably snapped at a temperature below the glass transition point of the amorphous polymer. Crosslinking of the conductive polymer can make it more or less brittle, depending upon the nature of the polymeric component, the type of crosslinking process, and the extent of the crosslinking. The quantity of carbon black, or other conductive filler, in the conductive polymer must be such that the composition has the required resistivity for the particular device. The resistivity is, in general, as low as possible for circuit protection devices, e.g. below 10 ohm-cm, preferably below 5 ohm-cm, particularly below 2 ohm-cm, and substantially higher for heaters, e.g. 10 2 -10 8 , preferably 10 3 -10 6 ohm-cm.
Suitable conductive polymer compositions are disclosed in U.S. Pat. Nos. 4,237,441 (van Konynenburg et al), 4,388,607 (Toy et al), 4,470,898 (Penneck et al), 4,534,889 (van Konynenburg et al), 4,545,926 (Fouts et al), 4,560,498 (Horsma et al), 4,591,700 (Sopory), 4,724,417 (Au et al), 4,774,024 (Deep et al), 4,775,778 (van Konynenburg et al), 4,859,836 (Lunk et al), 4,934,156 (van Konynenburg et al), 5,049,850 (Evans et al), 5,178,797 (Evans et al), 5,250,226 (Oswal et al), and 5,250,228 (Baigrie et al), and in pending U.S. application Nos. 07/894,119 (Chandler et al, filed Jun. 5, 1992), now U.S. Pat. No. 5,378,407, 08/085,859 (Chu et al, filed Jun. 29, 1993), now U.S. Pat. No. 5,451,919, 08/173,444 (Chandler et al, filed Dec. 23, 1994), now abandoned and 08/255,497 (Chu et al, filed Jun. 8, 1994, now U.S. Pat. No. 5,582,770. The disclosure of each of these patents and applications is incorporated herein by reference.
Conductive Polymer Elements
The conductive polymer is preferably present in the form of a laminar element having two principal faces which are parallel to each other and to which metal members are preferably attached. In many cases, the metal members are metal foils. Particularly suitable metal foils are disclosed in U.S. Pat. Nos. 4,689,475 (Matthiesen) and 4,800,253 (Kleiner et al), and in copending commonly assigned U.S. application No. 08/255,584 (Chandler et al, filed Jun. 8, 1994, now abandoned in favor of continuation application Ser. No. 08/672,496, filed Jun. 28, 1996, which is now abandoned in favor of continuation application Ser. No. 08/816,471, filed Mar. 13, 1997, the disclosure of each of which is incorporated herein by reference. The laminar conductive polymer element can be of any thickness which can be snapped, but is preferably less than 0.25 inch, particularly less than 0.1 inch, especially less than 0.05 inch, thick.
Discontinuities
The discontinuities which are present in the assemblies of the invention are preferably present in members which are secured to the principal faces of the conductive polymer element, so that, in the devices prepared from the assembly, the transverse faces of the conductive polymer element consist essentially of fractured surfaces. Preferably the discontinuities are continuous channels produced by etching a metal member so that it is separated into distinct segments, with the conductive polymer exposed at the bottom of the channel. However, the invention includes the use of discontinuities which are entirely within or formed in a surface of the conductive polymer, or which extend from members secured to the conductive polymer element into the conductive polymer element, for example channels routed through a metal member and partially into a conductive polymer element to which it is attached. In such cases, the transverse face will be partially sheared and partially fractured.
When there is a metal member secured to only one of the principal faces of the conductive polymer element, there need be discontinuities on one side only of the assembly. When there are metal members secured to both principal faces, discontinuities are needed in each metal member, positioned so that the conductive polymer will fracture along a path between the discontinuities. The discontinuities can be directly opposite to each other, so that the transverse fractured face meets the principal faces at a right angle, or offset from each other so that the transverse fractured face meets one of the principal faces at an angle less than 90°, e.g. 30° to 90°, preferably 45° to 90°, particularly 60° to 90°, and the other principal face at the complementary angle which is greater than 90°, e.g. 90° to 150°. The increased path length will influence the electrical properties of the device.
Devices
The invention can be used to make a wide variety of devices, but is particularly useful for making small devices, in which the edge properties of the conductive polymer element play a more important part than in large devices. The invention is especially useful for making circuit protection devices, e.g. those disclosed in U.S. Pat. Nos. 4,238,812 (Middleman et al), 4,255,798 (Simon), 4,272,471 (Walker), 4,315,237 (Middleman et al), 4,317,027 (Middleman et al), 4,329,726 (Middleman et al), 4,330,703 (Horsma et al), 4,426,633 (Taylor), 4,475,138 (Middleman et al), 4,472,417 (Au et al), 4,689,475 (Matthiesen), 4,780,598 (Fahey et al), 4,800,253 (Kleiner et al), 4,845,838 (Jacobs et al), 4,857,880 (Au et al), 4,907,340 (Fang et al), 4,924,074 (Fang et al), 4,967,176 (Horsma et al), 5,064,997 (Fang et al), 5,089,688 (Fang et al), 5,089,801 (Chan et al), 5,148,005 (Fang et al), 5,166,658 (Fang et al), and in co-pending, commonly assigned U.S. application Nos. 07/837,527 (Chan et al, filed Feb. 18, 1992), abandoned in favor of continuation application Ser. No. 08/087,017, now U.S. Pat. No. 5,436,609, 07/910,950 (Graves et al, filed Jul. 9, 1992), now abandoned in favor of continuation application Ser. Nos. 08/152,070, filed Nov. 12, 1993, and 08/121,717 (Siden et al, filed Sep. 15, 1993), now abandoned, the subject matter of both of the Graves et al and Siden et al applications being incorporated in a continuation-in-part application No. 08/302,138, filed Sep. 7, 1994, abandoned in favor of continuation application No. 07/727,869, filed Oct. 8, 1996, abandoned in favor of continuation application No. 08/900,787, filed Jul. 25, 1997, now U.S. Pat. No. 5,852,397, and 08/242,916 (Zhang et al, filed May 13, 1994) abandoned in favor of continuation application No. 08/710,925, filed Sep. 24, 1996, now U.S. Pat. No. 5,831,510. The disclosure of each of these patents and applications incorporated herein by reference.
Other devices which can be made are heaters, particularly sheet heaters, including both heaters in which the current flows normal to the plane of the conductive polymer element and those in which it flows in the plane of the conductive polymer element. Examples of heaters are found in U.S. Pat. Nos. 4,761,541 (Batliwalla et al) and 4,882,466 (Friel), the disclosures of which are incorporated herein by reference.
The conductive polymer element in the devices of the invention can have a single, curved, transverse face, as for example when the device is circular or oval, or can have a plurality of faces, as for example when the device is triangular, square, rectangular, rhomboid, trapezoid, hexagonal, or T-shaped, all of which shapes have the advantage that they can be produced without waste through the use of appropriate patterns of discontinuities. Circular and oval shapes can also be obtained by the present invention, but the residues of the fracturing process are generally not useful.
When the conductive polymer element has different electrical properties in different directions in the plane of the element, it is often possible to obtain devices which have significantly different properties by changing the orientation of the discontinuities relative to those directions.
The invention is illustrated in the accompanying drawings, in which the size of the apertures and channels and the thicknesses of the components have been exaggerated in the interests of clarity.
FIGS. 1-3 show an assembly which is ready to be divided into a plurality of devices by snapping it along the broken lines. The assembly contains a laminar PTC element 7 composed of a PTC conductive polymer and having a first principal face to which a plurality of upper metal foil members 30 are attached and a second principal face to which lower metal foil members 50 are attached. The upper members are separated from each other by upper fracture channels 301 running in one direction and upper fracture channels 302 at right angles thereto. The lower members are separated from each other by lower fracture channels 501 running in one direction and lower fracture channels 502 at right angles thereto.
FIGS. 4 to 6 are diagrammatic partial cross-sections through a laminated plaque as it is converted into an assembly which can be divided into a plurality of individual devices of the invention by snapping it along the broken lines and along lines at right angles thereto (not shown in the Figures).
FIG. 4 shows an assembly containing a laminar PTC element 7 composed of a PTC conductive polymer and having a first principal face to which upper metal foil members 30 are attached and a second primary face to which lower metal foil members 50 are attached. A plurality of round apertures, arranged in a regular pattern, pass through the assembly. An electroplated metal forms cross-conductors 1 on the surfaces of the apertures and metal layers 2 on the outer faces of the members 30 and 50 . The metal foil members are separated from each other by narrow fracture channels 301 , 302 , 501 , 502 as in FIGS. 1-3 (only channels 302 and 502 being shown in the drawing) and by relatively wide channels 306 and 506 parallel to channels 302 and 502 . FIG. 5 shows the assembly of FIG. 4 after the formation, by a photo-resist process, of (a) a plurality of parallel separation members 8 which fill the channels 306 and 506 and extend over part of the outer faces of the adjacent members 30 or 50 and (b) a plurality of parallel masking members 9 which fill some of the fracture channels and which are placed so that adjacent separation and masking members define, with the PTC element 7 , a plurality of contact areas. FIG. 6 shows the assembly of FIG. 5 after electroplating it with a solder so as to form layers of solder 61 and 62 on the contact areas and also layers of solder on the cross-conductors and in the fracture channels not filled by the masking members. It will be seen that the contact areas are arranged so that when an individual device is prepared by dividing up the assembly, the solder layers overlap only in the vicinity of the cross-conductor, so that if any solder flows from top to bottom of the device, while the device is being installed, it will not contact the layer of solder on the second electrode.
FIG. 7 shows a device obtained by snapping the assembly of FIGS. 1-3 along the fracture channels. The device has four transverse faces 71 (two of which are shown in FIG. 7 ), each of which has a fractured surface.
FIG. 8 shows a device similar to that in FIG. 7 but in which each of the transverse faces 72 meets one of the principal faces at an angle of less than 90° and the other principal face at an angle of more than 90°. Such a device can be made from an assembly as in FIGS. 1-3 except that the upper and lower fracture channels are offset from each other.
FIG. 9 shows a device similar to that in FIG. 8 except that the laminar PTC conductive polymer element has three layers, the outer layers 76 being composed of a PTC conductive polymer having one resistivity and the center layer 77 being composed of a PTC conductive polymer having a higher resistivity.
FIG. 10 shows a device obtained by snapping the assembly of FIG. 6 along the fracture channels. In FIG. 10 the device includes a laminar PTC element 17 having a first principal face to which first metal foil electrode 13 is attached, a second principal face to which second metal foil electrode 5 is attached, and four transverse fractured faces 71 (only two of which are shown in FIG. 10 ). Also attached to the second face of the PTC element is an additional metal foil conductive member 49 which is not electrically connected to electrode 15 . Cross-conductor 51 lies within an aperture defined by first electrode 13 , PTC element 17 and additional member 49 . The cross-conductor is a hollow tube formed by a plating process which also results in platings 52 , 53 and 54 on the surfaces of the electrode 13 , the electrode 15 and the additional member 49 respectively which were exposed during the plating process. In addition, layers of solder 64 , 65 , 66 and 67 are present on (a) the first electrode 13 in the region of the cross-conductor 51 , (b) the additional member 49 , (c) the second electrode 15 , and (d) the cross-conductor 51 , respectively.
FIGS. 11-13 show other patterns of fracture channels which can be employed to produce devices having, respectively, hexagonal, rhomboid and T-shape devices.
EXAMPLE
A plaque containing a laminar PTC conductive polymer element sandwiched between two nickel foils was prepared as described in the Example of Ser. No. 08/121,717. The plaque was converted into a large number of devices by the procedure described in the Example of copending commonly assigned application filed May 16, 1994 by Zhang and Fang, except for the following differences.
(1) The photo resists used to produce masks over the plated foils exposed not only the parallel strips corresponding to the gaps between the additional conductive members and the second electrodes, but also strips about 0.004 inch wide corresponding to the edges of the devices to be produced. The etching step, therefore, produced not only the channels between the additional conductive members and the second electrodes, as in the earlier application, but also upper and lower fracture channels in the metal foils.
(2) After the masking material and the solder had been applied, the plaque was not sheared and diced into individual devices but was instead broken into individual devices by placing the plaque between two pieces of silicon rubber, placing the resulting composite on a table, and then rolling a roller over the composite first in one direction corresponding to one set of fracture channels and then in a direction at right angles to the first. The composite was then placed on the table with its other side up, and the procedure repeated. When the composite was opened up, most of the devices were completely separated from their neighbors, and the few which were not completely separated could easily be separated by hand. | Electrical devices, particularly circuit protection devices, contain conductive polymer elements whose edges are formed by breaking the conductive polymer element, along a desired path, without the introduction of any solid body into the element. The resulting cohesive failure of the conductive polymer produces a distinctive fractured surface. One method of preparing such devices involves etching fracture channels in the electrodes of a plaque containing a PTC conductive polymer element sandwiched between metal foil electrodes, and then snapping the plaque along the fracture channels to form individual devices. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an exhaust heat recovery boiler, particularly, capable of reducing and removing a nitrogen oxide (NOx) contained in an exhaust gas.
[0002] In recent years, in order to improve an efficiency of power generation in the light of energy conservation, in addition to power generation by a gas turbine, there is a tendency of employing a combined cycle power generation plant which recovers an exhaust heat of the exhaust gas of the gas turbine so as to generate a steam and performs power generation by a steam turbine with the use the generated steam. Further, in order to improve an efficiency of power generation and a power generation output, the combined cycle power generation plant tends to be further made into a large capacity.
[0003] In the combined cycle power generation plant, an exhaust heat recovery boiler is employed to recover an exhaust heat and to generate a steam. The exhaust heat recovery boiler recovers a heat of the exhaust gas discharged from, for example, a gas turbine or diesel engine, and then, generates and supplies a driving steam for a steam turbine and a process steam hot water. Further, taking environmental protection into consideration, the exhaust heat recovery boiler includes a denitrator for reducing a harmful nitrogen oxide contained in the exhaust gas. In particular, recently, there is a tendency of providing a high performance denitrator which can remove 90% or more of the nitrogen oxide contained in the exhaust gas, in the exhaust heat recovery boiler.
[0004] A conventional exhaust heat recovery boiler will be described hereunder with reference to FIG. 22 which is a side view schematically showing the exhaust heat recovery boiler, and FIG. 23 which is a top plan view of an ammonia injection section (unit) of the exhaust heat recovery boiler.
[0005] As shown in these figures, a horizontal natural circulation type exhaust heat recovery boiler is a reheat dual pressure type boiler, which is opertively connected to, for example, a gas turbine G, diesel engine, or the like. A boiler duct 14 is provided therein with heat transfer pipes of a high pressure secondary superheater 15 , a reheater 16 , a high pressure primary superheater 13 , a high pressure evaporator 4 , a low pressure superheater 17 , a high pressure economizer 18 , a low pressure evaporator 19 and a low pressure economizer 20 , which are located successively in the described order in the boiler duct from the upstream side to the downstream side along an exhaust gas flow direction. Further, the boiler duct 14 is provided therein with an ammonia injection section 1 and an NOx removal reactor 5 , and the upper portion of the boiler is provided with a high pressure drum 6 and a low pressure drum 21 . A reference numeral 2 denotes an ammonia injection section support member, a reference numeral 3 denotes a high pressure drum downcomer pipe, a reference numeral 7 denotes an ammonia injection pipe, and a reference numeral 8 denotes an ammonia injection nozzle.
[0006] Further, it is to be noted that, in the above description, the some members or units are disposed to be adaptable for high and low pressures, but in an equipment having relatively small capacity, these members or units may be utilized as one member or unit, respectively.
[0007] Next, an operation of the aforesaid exhaust heat recovery boiler will be described hereunder.
[0008] An exhaust gas flowing into the exhaust heat recovery boiler successively passes through the high pressure secondary superheater 15 , the reheater 16 and the high pressure primary superheater 13 , and then, is mixed with ammonia in the ammonia injection section 1 . Then, the exhaust gas passes through the high pressure evaporator 4 , and thereafter, nitrogen oxide contained in the exhaust gas is removed by means of the NOx removal reactor (denitration reactor or denitrator) 5 including a catalyst layer facilitating a reduction reaction. Further, the exhaust gas successively passes through the low pressure superheater 17 , the high pressure economizer 18 , the low pressure evaporator 19 and the low pressure economizer 20 , and then, is discharged to the atmospheric air.
[0009] The ammonia injection section 1 of the exhaust heat recovery boiler is arranged on an upstream side of the high pressure evaporator 4 with respect to the exhaust gas flow direction. Further, ammonia needs to be uniformly mixed with the exhaust gas, and for this reason, the ammonia injection section 1 is arranged at a position separated from the denitration reactor 5 to some degree in a manner that the high pressure evaporator 4 is interposed between the injection section 1 and the denitration reactor 5 . When passing through the high pressure evaporator 4 having many heat transfer pipes regularly arranged, the ammonia and the exhaust gas are uniformly mixed. The ammonia is oxidized at a temperature of 490° C. or more, and then, a nitrogen oxide is generated. For this reason, it is not preferable to properly keep an NOx removal efficiency. Thus, a proper exhaust gas temperature is required, and then, in order to satisfy these conditions, the ammonia injection section 1 is arranged on a downstream side of the high pressure primary superheater 13 from the exhaust gas flow direction and on the upstream side of the high pressure evaporator 4 , and a planned gas temperature is about 470° C. In this manner, in the exhaust heat recovery boiler, a harmful nitrogen oxide contained in the exhaust gas is removed while heat exchange being made by the heat transfer pipes.
[0010] [0010]FIG. 24 is a view showing the ammonia injection section of FIG. 22 in the case of viewing from the exhaust gas flow direction.
[0011] In FIG. 24, the ammonia injection section 1 includes an ammonia injection pipe(s) 7 , an ammonia injection section support member(s) 2 and a number of ammonia injection nozzles 8 formed to the ammonia injection pipe 3 . The ammonia is mixed with an air in a mixer 22 , and then, passes through an ammonia injection section inlet connecting pipe 23 , an ammonia injection section header 24 and an ammonia injection section inlet pipe 25 , and thus, flows into an ammonia injection pipe 7 supported by the ammonia injection section support member 2 . The ammonia flowing into the ammonia injection pipe 7 is injected from many ammonia injection nozzles 8 provided on the ammonia injection pipe 7 , and then, is mixed with an exhaust gas. These many ammonia injection nozzles 8 are vertically alternately provided on the ammonia injection pipe 7 so that the ammonia is uniformly mixed with the exhaust gas. Further, the flow rate of ammonia is controlled by means of ammonia flow control valves 26 so that the ammonia is uniformly mixed with the exhaust gas. As described above, the ammonia injection section is constructed in a manner that ammonia is uniformly injected to the overall section of exhaust gas passage in the boiler duct.
[0012] As described above, the combined cycle power generation plant has a tendency of being made into a large capacity, and for this reason, the exhaust heat recovery boiler is also made into a large size. Thus, this is a factor of causing an increase in an installation space, cost and a unit price of power generation. In order to avoid the above disadvantage, there is a need of saving a space of the exhaust heat recovery boiler and making low cost design. The conventional exhaust heat recovery boiler has a problem of requiring a large space around the ammonia injection section and a drum downcomer pipe and increasing the entire length of the boiler.
[0013] Further, the combined cycle power generation plant is made into a large capacity, thus increasing the gas turbine power output while the exhaust gas temperature rising up. Accordingly, the exhaust heat recovery boiler has also a tendency of being made into high temperature and large capacity. For this reason, in the light of environmental conservation, it is obliged for the exhaust heat recovery boiler to include a high performance denitrator.
[0014] However, in the conventional exhaust heat recovery boiler, the exhaust gas temperature rises up, and also, the temperature of the ammonia injection section rises up depending upon a system for supplying a cooling steam to a gas turbine. For this reason, there is the possibility that ammonia injection is not performed at a proper temperature. In other words, there is a problem that it is difficult to realize high NOx removal efficiency in the exhaust heat recovery boiler which is made into a high temperature and large capacity.
SUMMARY OF THE INVENTION
[0015] An object of the present invention is to eliminate defects or drawbacks encountered in the prior art mentioned above and to provide an exhaust heat recovery boiler capable of saving and effectively utilizing an installation space for the exhaust heat recovery boiler by arranging an ammonia injection section to an optimal position and capable of effectively removing a nitrogen oxide contained in an exhaust gas in accordance with a high temperature and large capacity exhaust heat recovery boiler.
[0016] This and other objects can be achieved according to the present invention by providing, in one aspect, an exhaust heat recovery boiler in which an exhaust gas discharged from, for example, gas turbine, into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas so as to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising:
[0017] a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side;
[0018] a superheater disposed inside the boiler duct at an upstream side of the exhaust gas flow;
[0019] an evaporator disposed downstream side of the superheater superheater;
[0020] a denitration reactor disposed downstream side of the evaporator;
[0021] an economizer disposed downstream side of the evaporator;
[0022] a drum disposed outside the boiler duct and connected to the evaporator;
[0023] a downcomer pipe unit extending from the drum into the boiler duct; and
[0024] an ammonia injection unit disposed inside the boiler duct for injecting ammonia,
[0025] the ammonia injection unit being disposed upstream side of the evaporator closely to the downcomer pipe unit on either one of upstream side and downstream side of the downcomer pipe unit.
[0026] In another aspect, there is provided an exhaust heat recovery boiler in which an exhaust gas discharged from, for example, a gas turbine, into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas so as to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising:
[0027] a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side;
[0028] a superheater disposed inside the boiler duct at an upstream side of the exhaust gas flow;
[0029] an evaporator unit disposed downstream side of the superheater, the evaporator unit including a primary evaporator and a secondary evaporator disposed downstream side of the primary evaporator;
[0030] a denitration reactor disposed downstream side of the evaporator unit;
[0031] an economizer disposed downstream side of the evaporator unit;
[0032] a drum disposed outside the boiler duct and connected to the evaporator unit;
[0033] a downcomer pipe unit extending from the drum into the boiler duct; and
[0034] an ammonia injection unit disposed inside the boiler duct for injecting ammonia,
[0035] the ammonia injection unit and the downcomer pipe unit being disposed between the primary and secondary evaporators, the ammonia injection unit being arranged closely to the downcomer pipe on either one of upstream side and downstream side of the downcomer pipe unit.
[0036] In a further aspect, there is provided an exhaust heat recovery boiler in which an exhaust gas discharged from, for example, a gas turbine, into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas so as to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising:
[0037] a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side;
[0038] a superheater disposed inside the boiler duct at an upstream side of the exhaust gas flow;
[0039] an evaporator disposed downstream side of the superheater;
[0040] a denitration reactor disposed downstream side of the evaporator;
[0041] an economizer disposed downstream side of the evaporator;
[0042] a drum disposed outside the boiler duct and connected to the evaporator;
[0043] a downcomer pipe unit extending from the drum into the boiler duct; and
[0044] an ammonia injection unit disposed inside the boiler duct for injecting ammonia,
[0045] the evaporator being composed of a plurality of heat transfer tubes which are arranged in parallel to each other, the ammonia injection unit being arranged in parallel to the heat transfer pipes and being supported at upper and lower ends thereof by means of upper and lower headers.
[0046] In a still further aspect, there is provided an exhaust heat recovery boiler in which an exhaust gas discharged from, for example, a gas turbine, into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas so as to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising:
[0047] a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side;
[0048] a superheater disposed inside the boiler duct at an upstream side of the exhaust gas flow;
[0049] an evaporator disposed downstream side of the superheater;
[0050] a denitration reactor disposed downstream side of the evaporator;
[0051] an economizer disposed downstream side of the evaporator;
[0052] a drum disposed outside the boiler duct and connected to the evaporator;
[0053] a downcomer pipe unit extending from the drum into the boiler duct; and
[0054] an ammonia injection unit disposed inside the boiler duct for injecting ammonia,
[0055] the ammonia injection unit being disposed upstream side of the evaporator and arranged between the downcomer pipe unit and the superheater and the ammonia injection unit being supported at upper and lower ends thereof by means of upper and lower headers.
[0056] In preferred embodiments of the above various aspect, the ammonia injection unit is disposed on the upstream side or downstream side of the downcomer pipe unit.
[0057] The ammonia injection unit includes a plurality of ammonia injection pipes, a plurality of ammonia injection pipe supporting members and a number of ammonia injection nozzles, and the downcomer pipe unit includes a plurality of downcomer pipes, the ammonia injection pipe supporting members being disposed in parallel to the downcomer pipes with respect to the exhaust gas flow. The ammonia injection nozzles are formed to two ammonia injection pipes, which are arranged in the same level with respect to the exhaust gas flow, the injection nozzles being formed in a manner that injection nozzles formed to one ammonia injection pipe and injection nozzles formed to another one ammonia injection pipe are arranged alternately with respect to the exhaust gas flow direction.
[0058] The ammonia injection pipe supporting members are arranged between adjacent downcomer pipes, respectively. The ammonia injection pipe supporting members may be mounted to the downcomer pipes. The downcomer unit may commonly serve as the ammonia injection pipe supporting members.
[0059] The evaporator unit is composed of a plurality of heat transfer tubes arranged in parallel to each other.
[0060] According to the characters and structures of the exhaust heat recovery boiler of the present invention mentioned above, the ammonia injection unit (section) is arranged at the same position as the drum downcomer pipe unit when viewing from the exhaust heat recovery boiler. Thus, a dimension is reduced in the exhaust gas flow direction of the exhaust heat recovery boiler, and therefore, there can be provided a compact exhaust heat recovery boiler which can save a space with low cost design. Further, the ammonia injection section is supported by the downcomer pipe, so that the above effects will be enhanced.
[0061] Furthermore, the evaporator may be divided, and the ammonia injection unit and the boiler downcomer pipe unit are interposed between the divided evaporators. Thus, even if the exhaust gas temperature rises up due to a rise of the combustion temperature of the prime mover, heat exchange is made up to a proper temperature, and thereafter, ammonia is injected, and then, it is possible to remove a nitrogen oxide. Therefore, space saving is achieved in the exhaust heat recovery boiler, and the exhaust heat recovery boiler is provided at a low cost. Further, a nitrogen oxide can be sufficiently removed in a high temperature and large capacity exhaust heat recovery boiler as compared with the conventional arrangement, and it is possible to sufficiently take measures for environmental protection in the high temperature and large capacity exhaust heat recovery boiler.
[0062] Still furthermore, since no downcomer pipe is arranged on the pipe group outlet of the vaporizer, the mixed gas smoothly flows into the denitrator, and the catalyst is effectively acted. Therefore, it is possible to improve the NOx removal efficiency even with the same quantity of catalyst as compared with the conventional case.
[0063] The nature and further characteristic features of the present invention will be made more clear from the following descriptions of preferred embodiments made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] In the accompanying drawings:
[0065] [0065]FIG. 1 is a side view showing an ammonia injection section (unit) according to a first embodiment of the present invention;
[0066] [0066]FIG. 2 is a top plan view of the ammonia injection section as viewed from an arrow II-II in FIG. 1;
[0067] [0067]FIG. 3 is a view showing the ammonia injection section shown in FIG. 1 or FIG. 11 viewing it from an exhaust gas flow direction (arrow III);
[0068] [0068]FIG. 4 is a side view showing an ammonia injection section according to a modified embodiment of the first embodiment of the present invention;
[0069] [0069]FIG. 5 is a top plan view showing the ammonia injection section as viewed from an arrow V-V in FIG. 4;
[0070] [0070]FIG. 6 is a side view showing an ammonia injection section according to a second embodiment of the present invention;
[0071] [0071]FIG. 7 is a top plan view of the ammonia injection section as viewed from an arrow VII-VII in FIG. 6;
[0072] [0072]FIG. 8 is a view showing the ammonia injection section shown in FIG. 6 viewing it from an exhaust gas flow direction (arrow VIII);
[0073] [0073]FIG. 9 is a side view showing an ammonia injection section according to a modified embodiment of the second embodiment of the present invention;
[0074] [0074]FIG. 10 is a top plan view showing the ammonia injection section as viewed from an arrow X-X in FIG. 9;
[0075] [0075]FIG. 11 is a side view showing an ammonia injection section according to a third embodiment of the present invention;
[0076] [0076]FIG. 12 is a top plan view showing the ammonia injection section as viewed from an arrow XII-XII in FIG. 11;
[0077] [0077]FIG. 13 is a side view showing an ammonia injection section according to a modified embodiment of the third embodiment of the present invention;
[0078] [0078]FIG. 14 is a top plan view showing the ammonia injection section as viewed from an arrow XIV-XIV in FIG. 13;
[0079] [0079]FIG. 15 is a side view showing an ammonia injection section according to a fourth embodiment of the present invention;
[0080] [0080]FIG. 16 is a top plan view showing the ammonia injection section as viewed from an arrow XVI-XVI in FIG. 15;
[0081] [0081]FIG. 17 is a side view showing an ammonia injection section according to a modified embodiment of the fourth embodiment of the present invention;
[0082] [0082]FIG. 18 is a top plan view showing the ammonia injection section as viewed from an arrow XVIII-XVIII in FIG. 17;
[0083] [0083]FIG. 19 is a side view showing an ammonia injection section according to a fifth embodiment of the present invention;
[0084] [0084]FIG. 20 is a view showing the ammonia injection section shown in FIG. 19 viewing it from an exhaust gas flow direction (arrow XX);
[0085] [0085]FIG. 21 is a side view showing an ammonia injection section according to a sixth embodiment of the present invention;
[0086] [0086]FIG. 22 is a side view schematically showing a conventional exhaust heat recovery boiler;
[0087] [0087]FIG. 23 is a top plan view showing an ammonia injection section as viewed from an arrow XXIII-XXIII in FIG. 22; and
[0088] [0088]FIG. 24 is a view showing the ammonia injection section of the exhaust heat recovery boiler shown in FIG. 23 viewing it from an exhaust gas flow direction (arrow XXIV).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0089] Embodiments of the present invention will be described below with reference to FIGS. 1 to 21 of the accompanying drawings, in which like reference numerals are added to units or members corresponding to those shown in FIG. 22 and the detailed description of the common members are omitted herein, and that is, hereunder, only the essential portions of the exhaust heat recovery boiler of the present invention are mentioned for the sake of convenience.
[0090] FIGS. 1 to 3 are views showing an ammonia injection section according to a first embodiment of the present invention.
[0091] As shown in these figures, in this first embodiment, the ammonia injection section (unit) 1 is arranged on an upstream side of a high pressure evaporator 4 with respect to the exhaust gas flow direction in the boiler duct 14 and at the same position as a high pressure drum downcomer pipe of a high pressure drum 6 , and usually, a plurality of downcomer pipes are arranged so as to extend in parallel to each other. Further, the high pressure drum downcomer pipe 3 and an ammonia injection section support member 2 are arranged in parallel to the boiler horizontal direction, normal to the exhaust gas flow direction in the boiler duct. The ammonia injection section 1 includes plural pairs of ammonia injection pipes 71 , 72 , each pair including two pipes arranged side by side, a plurality of ammonia injection pipe support members 2 and a number of ammonia injection nozzles formed to the respective ammonia injection pipes. The two ammonia injection pipes 71 and 72 are arranged in parallel to each other in the exhaust gas flow direction. The ammonia injection nozzles 8 are alternately provided on each of the ammonia injection pipes 71 and 72 in the exhaust gas flow direction. Thus, an exhaust gas is mixed with ammonia in the ammonia injection section 1 , and then, passes through the high pressure evaporator 4 , and thereafter, a nitrogen oxide is removed by means of an NOx removal reactor 5 which functions as a denitration reactor or denitrator.
[0092] According to this embodiment, the ammonia injection section 1 is arranged on an upstream side of a high pressure evaporator 4 with respect to the exhaust gas flow direction in the boiler duct 14 and at the same position as a high pressure drum downcomer pipe 3 of a high pressure drum 6 . Thus, it is possible to save a space in the exhaust gas flow direction. Further, the exhaust gas flows from the ammonia injection section 1 into the denitration reactor 5 via the high pressure evaporator 4 , which is composed of a plurality of heat transfer pipes arranged in parallel to each other, so that a nitrogen oxide can be removed in a state that ammonia and exhaust gas are uniformly mixed with each other. Furthermore, a mixed gas smoothly flows into the denitration reactor 5 because no high pressure drum downcomer pipe 3 is provided on a pipe group outlet of the high pressure evaporator 4 , and therefore, catalyst is effectively activated, so that the NOx removal efficiency can be improved even the same quantity of catalyst as compared with the conventional case.
[0093] [0093]FIGS. 4 and 5 are views showing an ammonia injection section according to a modified embodiment of the first embodiment of the present invention.
[0094] As shown in these figures, this embodiment differs from the first embodiment in that the ammonia injection pipes 71 and 72 and the ammonia injection nozzle 8 are arranged on a down stream side of the high pressure drum downcomer pipe 3 with respect to the exhaust gas flow direction in the boiler duct 14 , and other construction is substantially the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components or units as those of the first embodiment, and the overlapping explanation is omitted.
[0095] According to this embodiment, the ammonia injection section 1 and the high pressure drum downcomer pipe 3 are arranged at the same position when viewing the side of the exhaust heat recovery boiler. Thus, it is possible to save a space in the exhaust gas flow direction. Further, the exhaust gas flows from the ammonia injection section 1 into the denitration reactor 5 via the high pressure evaporator 4 , so that a nitrogen oxide can be removed in a state that ammonia and exhaust gas are uniformly mixed with each other. Furthermore, the mixed gas smoothly flows into the denitration removal reactor 5 because no high pressure drum downcomer pipe 3 is provided on a pipe group outlet of the high pressure evaporator 4 , and therefore, catalyst is effectively activated, so that the NOx removal efficiency can be improved even the same quantity of catalyst as compared with the conventional case.
[0096] FIGS. 6 to 8 are views showing an ammonia injection section according to a second embodiment of the present invention.
[0097] As shown in these figures, this second embodiment differs from the first embodiment in that the high pressure drum downcomer pipe 3 functions as the ammonia injection section support member 2 in order to eliminate the ammonia injection section support member, and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0098] In this second embodiment, like the first embodiment, the exhaust gas is mixed with ammonia in the ammonia injection section 1 , and then, passes through the high pressure evaporator 4 , and thereafter, a nitrogen oxide is removed by means of the denitration reactor 5 . Further, the high pressure drum downcomer pipe 3 functions as the ammonia injection section support member 2 , so that the ammonia injection section support member is dispensed. Therefore, the number of components can be reduced.
[0099] [0099]FIGS. 9 and 10 are views showing an ammonia injection section according to a modified embodiment of the second embodiment of the present invention.
[0100] As shown in these figures, this embodiment differs from the second embodiment in that the ammonia injection pipes 71 and 72 and the ammonia injection nozzle 8 are arranged on a down stream side of the high pressure drum downcomer pipe 3 with respect to the exhaust gas flow direction in the boiler duct 14 , and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0101] According to this embodiment, the ammonia injection section 1 and the high pressure drum downcomer pipe 3 are arranged at the same position when viewing the side of the exhaust heat recovery boiler. Thus, it is possible to save a space in the exhaust gas flow direction. Further, the exhaust gas flows from the ammonia injection section 1 into the denitration reactor 5 via the high pressure evaporator 4 , so that a nitrogen oxide can be removed in a state that ammonia and exhaust gas are uniformly mixed with each other. Furthermore, the mixed gas smoothly flows into the denitration reactor 5 because no high pressure drum downcomer pipe 3 is provided on a pipe group outlet of the high pressure evaporator 4 , and therefore, catalyst is effectively activated, so that the NOx removal efficiency can be improved even with the same quantity of catalyst as compared with the conventional case.
[0102] [0102]FIGS. 11 and 12 are views showing an ammonia injection section according to a third embodiment of the present invention.
[0103] As shown in these figures, this third embodiment differs from the first embodiment in that the high pressure evaporator 4 is divided into a first high pressure evaporator section 9 and a second high pressure evaporator section 10 and that the ammonia injection section 1 and the high pressure drum downcomer pipe 3 are interposed between these first and second high pressure evaporator sections 9 and 10 , and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0104] In this third embodiment, the ammonia injection section 1 and the high pressure drum downcomer pipe 3 are arranged at the same position when view the side of the exhaust heat recovery boiler, like the first and second embodiments. Further, the high pressure drum downcomer pipe 3 and the ammonia injection section support member 2 are arranged in parallel in the horizontal direction, like the first embodiment. The exhaust gas passes through the first high pressure evaporator section 9 , and then, is mixed with ammonia in the ammonia injection section 1 . Further, the exhaust gas passes through the second high pressure evaporator section 10 , and thereafter, a nitrogen oxide is removed by means of the denitration reactor 5 . Therefore, according to this third embodiment, it is possible to improve the NOx removal efficiency as compared with the conventional case.
[0105] [0105]FIGS. 13 and 14 are views showing an ammonia injection section according to a modified embodiment of the third embodiment of the present invention.
[0106] As shown in these figures, this embodiment differs from the third embodiment in that the ammonia injection pipes 71 and 72 and the ammonia injection nozzles 8 are arranged on a down stream side of the high pressure drum downcomer pipe 3 with respect to the exhaust gas flow direction in the boiler duct 14 , and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0107] According to this embodiment, as the ammonia injection pipes 71 , 72 and the ammonia injection are arranged on a downstream side of the high pressure drum downcomer pipe 3 with respect to the exhaust gas flow direction, in addition to reduction in space, in the exhaust gas flow direction, of the exhaust heat recovery boiler, the exhaust gas passes more heat transfer pipe groups than the conventional one before it reaches the ammonia injection section 1 so that the exhaust gas reaches the ammonia injection section 1 after the heat exchanges are performed many times.
[0108] Further, since the temperature difference between the inlet of the exhaust heat recovery boiler and the ammonia injection section 1 becomes large, if the temperature of the exhaust gas at the inlet of the exhaust heat recovery boiler is higher than the conventional one, the temperature of the exhaust gas is reduced up to a proper temperature so that the exhaust gas can be guided into the ammonia injection section 1 . Accordingly, it is possible to increase the exhaust heat recovery efficiency and denitration efficiency.
[0109] [0109]FIGS. 15 and 16 are views showing an ammonia injection section according to a fourth embodiment of the present invention.
[0110] As shown in these figures, this fourth embodiment differs from the third embodiment in that the high pressure drum downcomer pipe 3 also functions as the ammonia injection section support member 2 in order to eliminate the ammonia injection section support member, and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0111] In this fourth embodiment, like the third embodiment, the exhaust gas is mixed with ammonia in the ammonia injection section 1 , and then, passes through the high pressure evaporator 4 , and thereafter, a nitrogen oxide is removed by means of the denitration reactor 5 . Further, the high pressure drum downcomer pipe 3 also functions as the ammonia injection section support member 2 , so that the ammonia injection section support member is dispensed. Therefore, the number of components can be reduced.
[0112] [0112]FIGS. 17 and 18 are views showing an ammonia injection section according to a modified embodiment of the fourth embodiment of the present invention.
[0113] As shown in these figures, this embodiment differs from the fourth embodiment in that the ammonia injection pipes 71 and 72 and the ammonia injection nozzles 8 are arranged on a down stream side of the high pressure drum downcomer pipe 3 with respect to the exhaust gas flow direction in the boiler duct 14 , and other construction is the same as that of the first embodiment. Thus, like reference numerals are used to designate the same components as those of the first embodiment, and the overlapping explanation is omitted.
[0114] According to this embodiment, like the third embodiment, it is possible to improve an exhaust heat recovery and an NOx removal efficiency, and further, the support member is dispensed, so that the number of components can be reduced.
[0115] [0115]FIGS. 19 and 20 are views showing an ammonia injection section according to a fifth embodiment of the present invention.
[0116] As shown in these figures, in this fifth embodiment, the ammonia injection section 1 is constructed in a manner that the ammonia injection pipe 7 is connected with the use of an upper pipe header 11 and a lower pipe header 12 . Further, the ammonia injection section 1 is inserted from the vertical direction, and is arranged on an intermediate portion of the high pressure evaporator 4 which is composed of a plurality of heat transfer pipes as mentioned before.
[0117] According to this fifth embodiment, in the ammonia injection section 1 , upper and lower pipe headers 11 and 12 are used as like a heat transfer pipe, so that the ammonia injection section can be located from the vertical direction. Further, like the third and fourth embodiments, a space in the exhaust gas flow direction is saved, and it is possible to perform ammonia injection at a proper exhaust gas temperature.
[0118] [0118]FIG. 21 is a view showing an ammonia injection section according to a sixth embodiment of the present invention.
[0119] As shown in FIG. 21, like the fifth embodiment, the ammonia injection section 1 is constructed in a manner that the ammonia injection pipe 7 is connected with the use of an upper pipe header 11 and a lower pipe header 12 . Further, the ammonia injection section 1 is inserted from the vertical direction and is arranged on the downstream side of the high pressure primary superheater 13 with respect to the exhaust gas flow direction. Further, the ammonia injection pipe 7 and the ammonia injection nozzle 8 have the same arrangement as that of the fifth embodiment of FIG. 20.
[0120] According to this sixth embodiment, like the fifth embodiment, the ammonia injection section 1 is constructed with the use of upper and lower pipe headers 11 and 12 . Therefore, a space in the exhaust gas flow direction is saved, and it is possible to perform ammonia injection at a proper exhaust gas temperature.
[0121] Further, it is to be noted that the present invention is not limited to the described embodiment and many other changes, modifications and combinations may be made without departing from the scopes of the appended claims.
[0122] For example, in the aforementioned various embodiments, although some units or members, such as superheater, evaporator, drum, downcomer and economizer, are utilized for high and low pressures, in the case of an equipment of relatively small capacity, only one unit or member may be utilized, respectively. That is, in the described embodiments, the units or members for low pressure may be eliminated. | An exhaust heat recovery boiler in which an exhaust gas discharged from a gas turbine into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising: a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side; a superheater; an evaporator; a denitration reactor; and an economizer, which are disposed inside the boiler duct in this order from the upstream side to the downstream side of the exhaust gas flow therein. A drum is disposed outside the boiler duct and connected to the evaporator and a downcomer pipe extending from the drum into the boiler duct. An ammonia injection unit is disposed inside the boiler duct for injecting ammonia, and the ammonia injection unit is disposed upstream side of the evaporator closely to the downcomer pipe unit on either one of upstream side and downstream side of the downcomer pipe unit. | 5 |
BACKGROUND OF THE INVENTION
[0001] Potassium citrate is used clinically to treat kidney stones by alkalizing the urinary pH and increasing urinary citrate concentration. However, its therapeutic efficacy is limited by its gastrointestinal complications such as irritation and ulcerations. Extended-release tablets of potassium citrate could minimize these side effects and have been shown to lead to sustained elevation of urinary pH and citrate concentration (Pak et al., 1984).
[0002] Considerable difficulties have been encountered in the preparation of extended-release matrix tablets containing potassium citrate. Potassium citrate is very soluble in water and the dosage required is very high. The only way to extend the release of potassium citrate tablet while keeping the tablet size acceptable for swallowing is to use a hydrophobic wax matrix, such as carnauba wax, wherein the total amount of inactive ingredients is below 25% w/w.
[0003] When the drug content is low, the carnauba wax can be dry mixed with the drug and other inactive ingredients prior to compression. For example, U.S. Pat. No. 4,904,478 teaches an extended-release wax matrix tablet of a highly water-soluble drug, sodium fluoride, wherein the carnauba wax, present at 35-70% w/w of the tablet weight, is dry mixed with the drug and other inactive ingredients prior to compression.
[0004] In the case of potassium citrate, because the drug dosage is high, the inactive ingredients including the extended-release agent(s) must be kept below 25% w/w to keep the tablet size acceptable for swallowing. If carnauba wax is used at less than 25% w/w, prior art teaches that the drug and carnauba wax should be heated until the carnauba wax liquefies, as described in Example 1 of US 2008/0131504 A1 (Mission Pharmacal, San Antonio, Tex., USA) to give an acceptable extended-release profile and friability. Friability is a measure of the durability of the tablet from the time it is compressed, to packaging, and to the time of use.
[0005] The process of US 2008/0131504A1 for making extended-release potassium citrate tablet containing carnauba wax is difficult. Heating until the carnauba wax liquefies requires a lot of time and then there is the problem of discharging the molten potassium citrate-carnauba wax mixture from the mixer. The cooled mass is extremely hard; therefore the molten mass must be poured into molds so that the cooled mixture is of appropriate size for feeding into a comminuting machine.
[0006] A simpler process for making the extended-release potassium citrate tablet is described in PCT/PH2012/000013, which surprisingly found that extended-release potassium citrate tablets containing carnauba wax could be produced without melting the wax. The potassium citrate-carnauba wax mixture is heated to a temperature below the temperature at which carnauba wax liquefies, and then discharged from the mixer as granules. The temperature is preferably higher than 55° C., and most preferably higher than 60° C. The cooled granulate can then be fed directly into a comminuting machine for size reduction, after which a lubricant is added, and the final mixture compressed into tablets. The tablet produced according to PCT/PH2012/000013 has the same dissolution profile as tablet produced by totally melting the wax. Hereafter, we will use melt-granulation and heat-granulation to refer to the processes described in US 2008/0131504A1 and PCT/PH2012/000013, respectively.
[0007] Mission Pharmacal, the innovator of the extended-release potassium citrate tablet, sells the tablet under the brand name Urocit-K, in three strengths: 5-meq, 10-meq, and 15-meq tablets. The daily dose of Urocit-K is 30-60 meq, which requires 6-12 tablets of the 5-meq, 3-6 tablets of the 10-meq, and 2-4 tablets of the 15-meq. Urocit-K is a wax matrix tablet containing potassium citrate, carnauba wax as extended-release agent, and magnesium stearate as lubricant.
[0008] Because of the large daily dose of potassium citrate, the preferred strength is the high dose 15-meq tablet. However, the 15-meq Urocit-K tablet, the only high dose tablet commercially available, has difficulty complying with the USP dissolution requirement. There is therefore a need for a robust high dose extended-release potassium citrate tablet that consistently passes USP dissolution requirement and with acceptable friability.
SUMMARY OF THE INVENTION
[0009] We have surprisingly found that high dose extended-release potassium citrate tablets can be produced by replacing a portion of the melt- or heat-granulated potassium citrate with non-granulated potassium citrate. Contrary to expectation, replacing a portion of the melt- or heat-granulated potassium citrate with non-granulated potassium citrate does not lead to tablets with poorer friability. The tablet of this instant invention has good friability and consistently passes the USP dissolution. Further, because melt- or heat-granulation is the most difficult step of the production process, replacing a portion of the melt- or heat-granulated potassium citrate with non-granulated potassium citrate increases production capacity and reduces production cost.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Extended-release potassium citrate tablet must comply with USP 35. Dissolution is performed in 900 ml water, apparatus 2 at 50 rpm, and must comply with the following dissolution specifications:
[0000]
TABLE 1
(dissolution, 12 units)
Time
All Units
Average
30 min
30-60%
35-55%
1 hour
45-75%
50-70%
3 hour
≧75%
≧80%
[0011] Friability was measured in an Erweka TAR20. Briefly, ten tablets were placed inside a baffled 287 mm ID drum. The drum was rotated at 25 rpm for 4 minutes. The difference in the total tablet weight before and after rotating the drum divided by the initial tablet weight is the friability. The desired friability for high dose extended-release potassium citrate tablet is not more than 3%.
Comparative Example 1
[0012] Three different commercial lots of 10-meq Urocit-K tablets were purchased, and subjected to USP 35 dissolution. The results are as follows:
[0000]
TABLE 2
Lot 1 (dissolution, 12 units)
Time
Range
Average
30 min
43.6-47.6%
45.2%
1 hour
57.9-61.1%
60.4%
3 hour
87.9-97.4%
91.7%
[0000]
TABLE 3
Lot 2 (dissolution, 12 units)
Time
Range
Average
30 min
41.2-44.5%
43.3%
1 hour
54.7-58.9%
57.7%
3 hour
82.5-89.4%
87.7%
[0000]
TABLE 4
Lot 3 (dissolution, 12 units)
Time
Range
Average
30 min
42.8-44.7%
43.6%
1 hour
56.4-59.0%
57.4%
3 hour
85.5-88.4%
86.5%
[0013] All three lots comply with USP 35 requirement for extended-release potassium citrate tablet. The average dissolution at 30 min and 1 hour are close to the mean values of the USP specifications at 45% and 60%, respectively.
Example 2
[0014] Three batches of 10-meq tablets were prepared by using the heat-granulation technique of PCT/PH2012/000013. Each batch is 100,000 tablets. The formulation is given in Table 5.
[0000]
TABLE 5
Ingredient
mg/tablet
% w/w
Potassium citrate•H2O
1080
85
Carnauba wax
177
14
Magnesium stearate
13
1
[0015] The procedure is as follows:
1. The potassium citrate was comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 8. 2. The comminuted potassium citrate from #1 was mixed with carnauba wax in a sigma mixer for 20 minutes. 3. The granule from #2 was comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 12. 4. The granule from #3 was heated in a jacketed sigma mixer, with continued mixing. Heating was continued until the temperature reached 70° C., which is below the melting point of carnauba wax. 5. The granule from #4 was discharged into plastic drums and allowed to cool to room temperature. 6. The cooled granule from #5 was comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 16. 7. Magnesium stearate was passed through mesh 30 and mixed with the comminuted granule of #6 in a sigma mixer for 2 minutes. 8. The granule from #7 was compressed into 18.9×8.6 mm elliptical tablet in a Stokes-Pennwalt rotary tablet press model 900.
[0024] Tablet hardness was 11-13 kp, and the friability for the three batches was less than 3%. The dissolution profile is as follows:
[0000]
TABLE 6
Batch 1 (dissolution, 12 units)
Time
Range
Average
30 min
43.5-48.8%
46.8%
1 hour
59.6-63.8%
61.9%
3 hour
89.9-94.7%
92.8%
[0000]
TABLE 7
Batch 2 (dissolution, 12 units)
Time
Range
Average
30 min
44.2-45.7%
44.8%
1 hour
59.4-62.6%
61.0%
3 hour
91.2-98.6%
93.5%
[0000]
TABLE 8
Batch 3 (dissolution, 12 units)
Time
Range
Average
30 min
44.0-45.2%
44.7%
1 hour
58.9-59.7%
59.3%
3 hour
88.0-89.8%
89.1%
[0025] All three batches comply with USP 35 requirement for extended-release potassium citrate tablet. The average dissolution at 30 min and 1 hour are close to the mean values of the USP specifications at 45% and 60%, respectively.
Comparative Example 3
[0026] Three different commercial lots of 15-meq Urocit-K tablets were purchased. The tablet weight of the 15-meq is 1.5× of the 10-meq Urocit-K tablet indicating that the two strengths are multiples of each other. The USP dissolution results are as follows:
[0000]
TABLE 9
Lot 1 (dissolution, 12 units)
Time
Range
Average
30 min
36.7-42.2%
39.1%
1 hour
49.9-53.2%
51.4%
3 hour
74.8-82.4%
77.9%
[0000]
TABLE 10
Lot 2 (dissolution, 12 units)
Time
Range
Average
30 min
37.1-40.2%
38.7%
1 hour
50.9-61.0%
55.2%
3 hour
79.7-82.8%
80.8%
[0000]
TABLE 11
Lot 3 (dissolution, 12 units)
Time
Range
Average
30 min
35.2-39.0%
37.2%
1 hour
49.9-52.2%
51.1%
3 hour
74.2-82.8%
79.2%
[0027] Two of the three lots fail USP dissolution. Further, the average values for the 30 min and 1 hour are close to the lower limits of the USP dissolution of 35% and 50%, respectively, indicating the formulation is not robust.
Example 4
[0028] Three batches of 15-meq tablets were prepared by using the heat-granulation technique of PCT/PH2012/000013. Each batch is 67,000 tablets. The formulation in w/w percent is the same as Example 2, except that the tablet weight is 1.5× (1905 mg). The process of preparation is the same as Example 2 except that the granule was compressed into 22.5×9.3 mm elliptical tablets with hardness of 11-14 kp. Friability was less than 3% for the three batches. Dissolution was performed according to USP 35. The results are as follows:
[0000]
TABLE 12
Lot 1 (dissolution, 12 units)
Time
Range
Average
30 min
37.9-41.5%
39.5%
1 hour
51.6-56.2%
54.5%
3 hour
82.1-87.3%
84.5%
[0000]
TABLE 13
Lot 2 (dissolution, 12 units)
Time
Range
Average
30 min
36.1-38.2%
37.1%
1 hour
48.9-53.2%
50.2%
3 hour
73.2-80.9%
76.8%
[0000]
TABLE 14
Lot 3 (dissolution, 12 units)
Time
Range
Average
30 min
35.6-39.6%
37.0%
1 hour
49.9-52.1%
51.2%
3 hour
74.0-82.9%
78.2%
[0029] Two of the three batches fail USP dissolution. Further, the average values for the 30 min and 1 hour are close to the lower limits of the USP dissolution of 35% and 50%, respectively, indicating that this high dose extended-release tablet prepared according to prior art is not robust.
Example 5
[0030] Three formulations of 15-meq tablets with varying concentrations of carnauba wax were prepared by using the heat-granulation technique of PCT/PH2012/000013. The formulations are given in Table 15:
[0000]
TABLE 15
15-meq Tablets (mg/tablet)
Ingredient
Example 5A
Example 5B
Example 5C
Potassium citrate•H2O
1620
1620
1620
Carnauba wax
223 (12%)
182 (10%)
133 (7.5%)
Magnesium stearate
19
18
18
[0031] The Process of preparation is the same as Example 2. The granules were compressed into 22.5×9.3 mm elliptical tablets. The results are as follows:
[0000]
TABLE 16
Example 5A (dissolution, 12 units)
Time
Range
Average
30 min
39.3-43.8%
40.2%
1 hour
53.2-57.7%
54.6%
3 hour
85.1-87.4%
86.7%
[0032] The tablet hardness was about 10 kp, and friability was less than 3%. Note that reducing the carnauba wax from 14% in Example 4 to 12% in Example 5A did not change the mean dissolution values for the 30 min and 1 hour time points significantly.
[0000]
TABLE 17
Example 5B (dissolution, 12 units)
Time
Range
Average
30 min
47.0-50.1%
48.5%
1 hour
62.2-65.6%
63.7%
3 hour
95.4-100.0%
96.9%
[0033] The maximum tablet hardness was 8.9 kp. While this formulation with 10% heat-granulated carnauba wax passes USP dissolution, the friability of 5.8% was not acceptable.
[0000]
TABLE 18
Example 5C (dissolution, 12 units)
Time
Range
Average
30 min
53.2-56.7%
54.8%
1 hour
70.3-74.1%
71.9%
3 hour
95.9-100.0%
98.1%
[0034] The maximum tablet hardness was 7.0 kp, and these tablets with 7.5% heat-granulated carnauba wax failed friability (capped tablets) and USP dissolution.
[0035] The examples of the prior art—Comparative Example 3, Example 4, Example 5A, Example 5B, and Example 5C—show that it is difficult to achieve a good balance of friability and robust dissolution for high dose extended-release potassium citrate tablet when all of the potassium citrate is melt- or heat-granulated with the carnauba wax.
Example 6
[0036] Three formulations of 15-meq tablets with varying ratios of non-granulated and heat-granulated potassium citrate were prepared. The heat-granulated potassium citrate was prepared according to steps 1-6 of Example 2. This potassium citrate-carnauba wax heat-granulate is 85.9% potassium citrate and 14.1% carnauba wax.
[0037] To prepare the non-granulated potassium citrate for dry addition, potassium citrate was comminuted in a Fitzmill D6, knives forward, medium speed using perforated screen mesh 14.
[0038] The heat-granulated potassium citrate, and non-granulated potassium citrate were combined according to Table 19:
[0000]
TABLE 19
15-meq Tablets (mg/tablet)
Example 6A
Example 6B
Example 6C
85/15
80/20
75/25
Heat-granulated potassium
1603 mg
1509 mg
1414 mg
citrate-carnauba wax
Non-granulated potassium
243 mg
324 mg
405 mg
citrate monohydrate
Magnesium stearate
19 mg
19 mg
18 mg
[0039] The heat-granulated potassium citrate and the non-granulated potassium citrate were mixed in a Sigma mixer for 20 minutes. Magnesium stearate (passed thru mesh 30) was then added, and mixed for 3 minutes. The final granule was compressed into 22.5×9.3 mm elliptical tablet in a Stokes-Pennwalt rotary tablet press model 900.
[0040] Example 6A contains 15% non-granulated potassium citrate, Example 6B contains 20% non-granulated potassium citrate, and Example 6C contains 25% non-granulated potassium citrate. The formulations of Table 19 in percent w/w is given in Table 20:
[0000]
TABLE 20
15-meq Tablets in mg/tablet (% w/w)
Ingredient
Example 6A
Example 6B
Example 6C
Potassium citrate•H2O
1620 (86.9%)
1620 (87.5%)
1620 (88.2%)
Carnauba wax
226 (12.1%)
213 (11.5%)
199 (10.8%)
Magnesium stearate
19 (1%)
19 (1%)
18 (1%)
[0041] These tablets were subjected to USP dissolution. Results are as follows:
[0000]
TABLE 21
Example 6A (dissolution, 12 units)
Time
Range
Average
30 min
42.4-45.6%
43.6%
1 hour
57.5-59.5%
58.2%
3 hour
88.9-92.9%
90.4%
[0042] The tablet of Example 6A passes the USP dissolution, with the 30 min and 1 hour data close to the mean values of the USP dissolution specifications of 45% and 60%, respectively. The tablet hardness was 10 kp and friability was 1.9%. This example shows that combining heat-granulated potassium citrate and non-granulated potassium citrate according to this instant invention leads to high dose extended-release potassium citrate with good friability and robust dissolution.
[0000]
TABLE 22
Example 6B (dissolution, 12 units)
Time
Range
Average
30 min
41.8-47.1%
44.3%
1 hour
55.8-59.5%
58.1%
3 hour
88.7-93.0%
90.9%
[0043] The tablet of Example 6B passes the USP dissolution, with the 30 min and 1 hour data close to the mean values of the USP dissolution specifications of 45% and 60%, respectively. The tablet hardness was 11 kp and friability was 1.4%. This example shows that combining heat-granulated potassium citrate and non-granulated potassium citrate according to this instant invention leads to high dose extended-release potassium citrate with good friability and robust dissolution.
[0000]
TABLE 23
Example 6C (dissolution, 12 units)
Time
Range
Average
30 min
44.2-50.3%
46.2%
1 hour
58.5-65.6%
62.2%
3 hour
97.5-100.0%
98.2%
[0044] The tablet of Example 6C passes the USP dissolution, with the 30 min and 1 hour data close to the mean values of the USP dissolution specifications of 45% and 60%, respectively. The tablet hardness was 11.5 kp and friability was 1.8%. This example shows that combining heat-granulated potassium citrate and non-granulated potassium citrate according to this instant invention leads to high dose extended-release potassium citrate with good friability and robust dissolution.
Example 7
[0045] Three additional large production-scale batches of 15-meq tablets according to Example 6B were prepared. Each batch is 83,000 tablets. Tablet hardness of the three batches was 10-12 kp, and friability was 1-2%. Dissolution was performed according to USP 35. The results are as follows:
[0000]
TABLE 24
Example 7 - Batch 1 (dissolution, 12 units)
Time
Range
Average
30 min
45.4-47.1%
46.2%
1 hour
59.6-62.9%
61.2%
3 hour
89.3-95.4%
92.9%
[0000]
TABLE 25
Example 7 - Batch 2 (dissolution, 12 units)
Time
Range
Average
30 min
44.7-45.9%
45.3%
1 hour
60.5-62.9%
61.4%
3 hour
93.3-97.0%
95.3%
[0000]
TABLE 26
Example 7 - Batch 3 (dissolution, 12 units)
Time
Range
Average
30 min
44.8-48.1%
46.3%
1 hour
59.2-61.5%
60.3%
3 hour
89.9-93.3%
92.1%
[0046] The above data clearly shows robust batch-to-batch dissolution and friability of the high dose extended-release potassium citrate tablets prepared according to this instant invention.
Example 8
[0047] A melt-granulate of potassium citrate-carnauba wax was prepared according to the formulation of Table 27:
[0000]
TABLE 27
Ingredient
% w/w
Potassium citrate•H2O
85.9
Carnauba wax
14.1
[0048] The procedure is as follows:
1. The potassium citrate was comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 8. 2. The comminuted potassium citrate from #1 was mixed with carnauba wax in a sigma mixer for 20 minutes. 3. The granule from #2 was comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 12. 4. The granule from #3 was heated in a jacketed sigma mixer, with continued mixing. Heating was continued until the carnauba wax was fully melted (above 80° C.), and for an additional 10 minutes thereafter. 5. The liquid mass from #4 was poured into 2″×2″×2″ molds, and allowed to cool to room temperature. 6. The blocks from #5 were comminuted in a Fitzmill D6, knives forward, using perforated screen mesh 16.
Example 9
[0055] Two large production-scale batches of 15-meq tablets according to Example 6B were prepared, but replacing the heat-granulated potassium citrate-carnauba wax with the melt-granulate of Example 8. Each batch is 83,000 tablets. Tablet hardness of the two batches was 10-12 kp, and friability was less than 3%. Dissolution was performed according to USP 35. The results are as follows:
[0000]
TABLE 24
Example 9 - Batch 1 (dissolution, 12 units)
Time
Range
Average
30 min
45.3-47.4%
45.7%
1 hour
58.9-62.8%
61.6%
3 hour
90.4-95.7%
92.7%
[0000]
TABLE 25
Example 9 - Batch 2 (dissolution, 12 units)
Time
Range
Average
30 min
45.4-48.0%
46.5%
1 hour
61.1-65.1%
62.7%
3 hour
89.4-94.6%
92.3%
[0056] The above data clearly shows robust batch-to-batch dissolution and friability of the high dose extended-release potassium citrate tablets prepared according to this instant invention. Further, melt-granulated potassium citrate-carnauba wax can be used in place of the heat-granulated potassium citrate-carnauba wax, with the same results.
[0057] This instant invention encompasses all the combinations of melt-/heat-granulated potassium citrate and non-granulated potassium citrate, where the melt-/heat-granulated potassium citrate can contain carnauba wax levels different from the above embodiments. It is within the capability of a person ordinarily skilled in the art to conduct simple experiments to determine the optimum ratio of melt-/heat-granulated and non-granulated potassium citrate to arrive at a formulation with robust batch-to-batch dissolution and friability. | The present invention relates to a high dose extended-release potassium citrate tablet containing carnauba wax, which contains a first portion of melt- or heat-granulated carnauba wax and potassium citrate; and a second portion of non-granulated potassium citrate. The high dose extended-release potassium citrate tablet of this invention has robust batch-to-batch dissolution and friability; and leads to improved production capacity and reduced production cost. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an elastic roller for fixing electrophotographic images, and more specifically, to an image fixing elastic roller which is used as a pressure roller for uniformly pressing an image support sheet relative to an image fixing heating roller.
2. Description of the Prior Art
In general, fixing devices of conventional electrophotographic copying machines or the like are structured such that a non-fixed toner image transferred onto an image support sheet, such as a paper sheet, is heat-pressed between a non-adhesive heating roller and an elastic pressure roller so as to be melted and fixed thereon.
Conventional toner image fixing devices are generally, formed by providing a heat-resisting elastic layer, such as silicone sponge, around a metal core, and further providing a non-adhesive layer, such as a fluoroplastic, on the outer periphery of the elastic layer to prevent the adhesion of toner to the pressure roller.
Since it is common to operate such a fixing device intermittently, it is desired that the heating roller rapidly increases its surface temperature to start the fixing operation within a short period of time after the fixing device is brought into operation. Similarly, it is also desired that the pressure roller approaches the surface temperature of the heating roller within a short period of time after the fixing device is brought into operation. In view of this, the elastic layer of the pressure roller is generally formed of a sponge layer having a relatively low heat capacity and low heat conductivity.
However, there has been a problem such that it has been difficult to fix high-quality images on a number of paper sheets continuously in accordance with the prior art fixing devices, since paper wrinkles are easily formed with a lapse of operating time after the activation of the fixing device.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved image fixing elastic roller capable of preventing the deterioration of image quality by suppressing the generation of paper wrinkles, notwithstanding the continuous fixing of images, thereby providing a large number of high-quality fixed images in a successive manner.
According to a first aspect of the present invention, an image fixing elastic roller comprises a metal core; a sponge layer provided around the metal core; and a fluoroplastic layer provided around the sponge layer, wherein the fluoroplastic layer is provided with a plurality of distributed holes.
According to a second aspect of the present invention, an image fixing elastic roller comprises a metal core; a sponge layer provided around the metal core; and a fluoroplastic layer provided around the sponge layer, wherein the fluoroplastic layer is provided with a plurality of distributed holes, and a distribution density of which is made larger at a central portion of the roller than at end portions thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood from the detailed description given hereinbelow and from the accompanying drawings of the preferred embodiments of the present invention, which are given by way of example only, and are not intended to limit the present invention.
FIG. 1A is a front view of an image fixing elastic roller for illustrating first and second preferred embodiments of the present invention, as compared with a comparative example; and
FIG. 1B is a side view of the image fixing elastic roller of FIG. 1A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Preferred embodiments of the present invention will be described hereinbelow with reference to the accompanying drawings. In FIGS. 1A and 1B, there are shown the front and side views of an image fixing elastic roller for explaining first and second preferred embodiments of the present invention and also a comparative example.
First, the comparative example will be described. Referring to FIG. 1B, an iron core 1 having a diameter of 12 mm was applied with a primer. Thereafter, the primer applied iron core 1 was then coated with a foaming silicone rubber composition by extrusion, and then heated to expand and vulcanized so as to form a foamed silicone rubber sponge layer 2 having 32 degrees of Asker C-type hardness (load =300 g) with an expansion ratio of 170% and a thickness of approximately 6 mm.
Subsequently, the surface of the sponge layer 2 was abraded and applied with a bridged type adhesive, and then was coated with a PFA (perfluoroalkoxyl) plastic tube, which is made adhesive at the inner side and has a thickness of 50μm, and heated for adhesion. Hence, an elastic roller having an outer diameter of 20 mm and a length of 225 mm with fluoroplastic layer 3 at the outermost and an Asker C-type hardness (load =300 g) of 45 degrees was produced.
The first preferred embodiment will be described hereinbelow.
Embodiment 1
The surface of the elastic roller of the sample was pricked with a needle, which has a length of 3 mm and a diameter of 0.6 mm, at an interval of 10 mm with margin of 12.5 mm from both ends of the elastic roller and along 8 straight lines, which are in parallel and 45 degrees apart with respect to a longitudinal center axis of the elastic roller. As a result, an elastic roller of the first preferred embodiment having the fluoroplastic layer 3 provided with 21 holes A aligned on each of 8 straight lines and in total of 168 holes was produced.
The second preferred embodiment will now be described hereinbelow.
Embodiment 2
The surface of the elastic roller of the first embodiment was further pricked with a needle, which has a length of 3 mm and a diameter of 0.6 mm, at an interval of 10 mm with margin of 67.5 mm from both ends of the elastic roller for providing 10 holes per each of 8 additional straight lines inbetween the 8 straight lines of the first embodiment and in total of 80 holes B. As a result, an elastic roller of the second preferred embodiment having the fluoroplastic layer 3 provided with 10 additional holes B aligned on each of 8 additional straight lines and thus arranged are 248 holes (A and B) in total in a zigzag fashion at the central portion thereof for providing a higher distribution density of the holes at a central portion than at end portions thereof.
A test has been carried out with an electrophotograph fixing device by incorporating the fixing elastic rollers of the present invention. By activating the device, electrophotographic copying was successively performed in the following order:
a: copied black solid images on 2 sheets of copying paper of 60 g;
b: copied character images on 30 sheets of copying paper of 60 g; and
c: copied black solid images on 2 sheets of copying paper of 60 g.
The copying operation was repeated with respect to 5 rollers for each of the example, first preferred embodiment and second preferred embodiment. Evaluation of the copying was implemented by utilizing the copied black solid images whether or not there were any presence of paper wrinkles, whereas the first sheet of the black solid image copied by step a is designated as a1 and that the second sheet is a2, and the first sheet of the black solid image copied by step c is designated as c1 and that the second sheet is c2. The results of the evaluation are set forth in Table 1. Each figure represents the total points for each of the 5 elastic rollers, wherein 2 points indicate no paper wrinkles, 1 point indicates earthworm-like wrinkles, and 0 points indicate paper wrinkles.
TABLE 1______________________________________elastic roller a1 a2 c1 c2comparative 10 10 3 3exampleembodiment 1 10 10 5 8embodiment 2 10 10 10 8______________________________________
As apparent from Table 1, the preferred embodiments of the invention, wherein the image fixing elastic rollers are provided with holes, provide considerably improved image quality after repeated copying vis-a-vis the comparative example. This present invention effectively suppresses the formation of paper wrinkles.
Accordingly, in the fixing device incorporating the elastic rollers of the preferred embodiments of the present invention, the stable fixing operation can be performed immediately after the heating roller is warmed to a required temperature, and paper wrinkles are effectively suppressed even upon successive image fixing operations. Further, in accordance with the present invention, the stable fixing operation can be continued reliably for a large number of high-quality images on copying paper.
As further apparent from Table 1, according to the second preferred embodiment, the image fixing elastic roller having concentrated holes A and B at the central portion further improves the image quality after repetition of copying vis-a-vis the comparative example.
It is to be understood that this invention is not to be limited to the preferred embodiments and modifications described above, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. | An image fixing elastic roller includes a metal core, a sponge layer provided around the metal core, and a fluoroplastic layer provided around the sponge layer, in which the fluoroplastic layer is formed with a plurality of holes in a predetermined distribution for suppressing paper wrinkles from causing, and further, to improve the performance, the fluoroplastic layer is formed with additional holes for providing a higher distribution density at a central portion thereof than at end portions thereof. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a digital camera, and more particularly, to a system in or usable with the digital camera for assisting the capture of text images. The system may be applied to handheld cameras and to mounted cameras.
2. Description of Related Art
It is well known to use scanners, such as flatbed scanners, to capture and convert bitmap images of documents to text or structured documents. An entire image can either be captured at maximum resolution, or a low-resolution pre-scan can be performed for selection of text regions, followed by a high resolution re-scan of the specified regions. In such a case, the document will always have a fixed optical relation to the scanner, and the resolution of the scanner is such that most documents can be captured with adequate resolution for optical-character-recognition (OCR) processing to convert the image to text.
However, a problem can occur for users of mounted or handheld digital cameras when capturing images of text documents. This is a relatively new area of use of digital cameras, of which not many users have experience. The problem is that the resolution of such cameras tends to be substantially less than that of flatbed scanners, and care is required to ensure that the captured image has sufficient resolution for OCR. There is a significant difference between the minimum resolution (visual resolution) at which a user can read the text in an image of a document, and the minimum resolution (OCR resolution) at which OCR will perform satisfactorily. The minimum OCR resolution is much greater than the minimum visual resolution.
For a camera, the size (or resolution) of the text characters in the image is directly dependent on the distance between the camera and the document being captured. Although experienced users may be able to judge this themselves, this tends to be a severe problem for novice users of the camera. For example, a novice user may be tempted to position the camera at a height at which he can just read the text in the field of view indicator. This would be too small for good OCR results, but the user would not find this out until he came to process the captured images. The image capture will be useless if the captured images cannot be processed for OCR. Moreover, once a user has encountered such a critical problem using a digital camera for the first time (instead of a traditional scanner), it is likely that he will never attempt to use the same system again.
Additionally, even when experienced users of digital cameras are confronted with a document with an extreme font size, they will often waste a lot of time repeatedly repositioning the camera until they achieve satisfactory results.
U.S. Pat. No. 6,473,523, filed May 4, 1999, entitled “Portable Text Capturing Method And Device Therefor”, which is incorporated herein by reference, discloses a system in which a handheld camera can provide feedback to the user about the suitability of an image for OCR. However, the suggested feedback is based on limited factors, which might not be directly representative if the text size in all cases. One of the problems is that the user generally requires an indication rapidly (in real time image capture), and so any processing must be performed very quickly. The described technique is to detect the spacing between lines of text. This can be processed relatively quickly, but as mentioned above, might not give an accurate determination of the text size in all cases. Moreover, the described feedback does not provide any guide as to better or corrective action the user should take to improve the image quality.
SUMMARY OF THE INVENTION
In one aspect, it would be desirable to improve the indication provided to a user of a digital camera, of the suitability of an image for OCR.
Broadly speaking, a first aspect of the invention is to provide an indication to the user of whether the resolution (size) of text characters in the image is smaller than a desired minimum for OCR, or whether the resolution is larger than a desired maximum.
Preferably, the indication includes a guide as to the corrective action the user should take to improve the quality of the image for OCR. For example, if the resolution is too small, the indication may be a “down” indicator to indicate that the user should move the camera closer to the document object, to increase the image resolution. Alternatively, if the resolution is too large, the indication may be an “up” indicator to indicate that the user should move the camera further from the document object, to decrease the image resolution.
In a second aspect, it would be desirable to improve operation of the camera, to provide automatic capture at an optimum resolution.
Broadly speaking, the second aspect of the invention is to control an electronic zoom lens of the camera in response to the detected image resolution (or the detected size of text characters in the image). For example, if the resolution is determined to be too small, then a zoom control signal can be generated to control the zoom lens to increase the zoom magnification (equivalent to moving the camera closer to the document). If the resolution is determined to be too large, then the zoom control signal can be generated to control the zoom lens to decrease the zoom magnification (equivalent to moving the camera further from the document).
In a third aspect, it would be desirable to improve the techniques for detecting the suitability of an image for OCR.
Broadly speaking, in accordance with the third aspect, the resolution (size) of text in the image is determined by identifying the heights of text lines in the image (in contrast to the technique of identifying the line spacing as in U.S. patent application Ser. No. 09/304,659).
The text height is calculated by: determining the run lengths of runs of pixels in the image; and analyzing the run lengths to identify a predominant length corresponding to the average character height (in pixels).
Preferably, the method is repeated for each of two axes of the image, the axes being determined so as to be parallel to, and perpendicular to, the direction of the lines of text. Such a determination of axes is effective to resolve the image for skew, and any suitable deskewing method may be used.
The above aspects may be used independently. However, additional advantages are achieved by combining two or more in combination.
The above aspects may be implemented within a camera, or by an external system coupled to a camera.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic block diagram of the functional components in a first embodiment of a digital camera imaging system for documents;
FIG. 2 is a flow diagram showing the process steps for analyzing the suitability of the image for OCR;
FIG. 3 is a schematic diagram illustrating the calculation of skew in the image;
FIG. 4 is a flow diagram showing the detailed process steps for determining the height of text characters in the image;
FIGS. 5 ( a ) and ( b ) are schematic diagrams showing example captured images at high and low resolutions, respectively;
FIGS. 6 ( a ) and ( b ) are schematic diagrams showing a gray-scale profile taken in a vertical direction through the image of FIGS. 5 ( a ) and ( b ) respectively (continuous line is the gray-scale profile; broken line is a thresholded profile after equalizing and thresholding);
FIGS. 7 ( a ) and ( b ) are schematic histograms for the thresholded profiles of FIGS. 6 ( a ) and ( b );
FIGS. 8 ( a )-( d ) are schematic illustrations of the display icons for correcting the position of the camera;
FIG. 9 is a perspective view of a second embodiment of digital camera;
FIG. 10 is a block diagram of functional components of the camera of FIG. 9 ; and
FIG. 11 is a flow diagram showing the processing steps for processing an image to determine its suitability for OCR.
DETAILED DESCRIPTION
Referring to FIG. 1 , a digital document capture system 10 comprises a digital camera 12 mounted above a surface 14 by means of a stand 16 , for viewing a paper document 18 placed on the surface 14 . The stand may be free-standing (such as a tripod frame), or it may consist of one or more legs integral with, or coupled to, the case of the camera. In the present embodiment, it is preferred that the height of the stand be adjustable; for example, the legs may be telescopically extendable, although this is not essential if the camera has an adjustable zoom lens.
A suitable digital camera 12 is the Vesta Pro camera made by Philips.
The output of the digital camera 12 is coupled as an input to a computer 20 , running an application program for displaying and/or processing the document image captured by the camera 12 . A suitable application program is, for example, PageCam produced by Xerox Corporation. However, those skilled in the art will be aware of many other suitable programs for display and processing captured digital document images.
The computer 20 may be a stand-alone computer, or it may be coupled to a network (not shown) for transmitting document images, or converted text documents, to the network. Preferably, the application program includes OCR processing to convert a document image to text characters (or to a structured document). However, it will be appreciated that (in the case of a networked system) such conversion could be performed by another computer, which may be in communication over the network.
One of the problems for users is the setting of the height of the camera 12 relative to the document 18 , to ensure that the text in the document image has sufficient resolution for OCR. As explained previously, the minimum resolution for satisfactory OCR is significantly greater than the image resolution readable by the human eye. In other words, the mere fact the image is legible on the computer screen does not mean that it is suitable for OCR. Particularly for inexperienced users, it is difficult to judge the camera distance suitable for a document to ensure reliable OCR, while also capturing as much of the document as possible within the image. It will be appreciated that, generally, it is not possible to perform the OCR instantly or even at a rate as high as the incoming frame rate from the camera 12 (typically about five frames or more per second). Therefore, the OCR has to be performed as a separate operation after image capture.
In the present embodiment, the application program on the computer 20 is modified to assess the suitability of an image for OCR, and to provide feedback to the user about how to modify the camera position (or camera zoom setting) to improve the quality of the image for OCR.
FIG. 2 shows the general processing steps required for assessing the suitability of the image for OCR. In general, it should be remembered that the processing is preferably adapted so that it can be carried out quickly, to provide the user with an indication rapidly if the image is not suitable for OCR.
Ideally, the following analysis steps would be best carried out on a binary image (i.e. an image in which pixels are either “on” or “off”). However, it would be very time consuming to convert an input image into a binary image, in view of the potentially huge variation in resolution and blur in an input image. Therefore, the processing is carried out instead on a gray-scale (luminance) profile. Accordingly, a first step 22 in FIG. 2 is to extract the gray-scale (luminance) component of the input signal, and to store this in a region of buffer memory.
At step 24 , the image is resolved for skew. Generally, the user will not have aligned the document perfectly with the horizontal and vertical axes of the field of view of the camera (i.e. with the axes of the image “window”). In some cases, the lines of text may also be slightly inclined on the document. Therefore, for either reason, the second step 24 is preferably carried out to identify the skew angle, so that the text lines can be analyzed in a predictable manner.
Various skew detection/correction algorithms are know to those skilled in the art, for example, see for example U.S. Pat. No. 6,178,270, the contents of which are incorporated herein by reference, and the above incorporated U.S. patent application Ser. No. 09/304,659. The present embodiment uses a variance-maximization technique, based on the extracted gray-scale profiles.
Referring to FIG. 3 , the variance between adjacent scan-lines is calculated for different angles of inclination θ of the scan-lines. The calculation may either be performed by rotating the image in the memory, or by mathematically addressing the memory along lines at the angle θ. If the deskewing technique is carried out merely for the purpose of the determining the suitability of the image for OCR, then a high accuracy of θ is generally not required, and so it is preferred to increment θ by increments of at least 1°, more preferably about 3°. The larger the increment, then the less repeated calculation that needs to be carried out, and the quicker the de-skewing process.
For many documents, there is a 90° ambiguity in the skew angle (due to text layout in blocks or in columns, etc.). Therefore, at step 24 two distinct peaks in the variance are selected at roughly 90° to each other, and subsequent processing is repeated for both of these candidate angles.
At step 26 , a routine is carried out to estimate the height of characters (in pixels). The principle is to determine the character heights by statistically analyzing the “run-lengths” in the values of adjacent pixels in each of the perpendicular scan-line directions determined in step 24 . Characters of the same height, and including a vertical stroke will tend to produce a prominent stroke length, i.e. a run of adjacent pixels of a similar value (below, or above, a certain gray-scale threshold value, or differing by less than a certain gray-scale threshold value). Since the two scan directions determined in step 24 are perpendicular, one will correspond to the horizontal direction of the text, and the other will correspond to the vertical direction (in which the vertical stroke length can be detected).
The processing in step 26 is additionally refined, as will be apparent from the following description, with reference to FIGS. 4-7 . FIG. 4 shows the steps of the height estimation routine; FIGS. 5 ( a ) and ( b ) show sample relative high and relatively low resolution images; FIGS. 6 and 7 show examples of the statistical analysis of the image processing.
Referring to FIG. 4 , a first step 30 is to equalize the gray-scale profiles in the image for different lighting conditions (e.g. shadows), and different colors of objects captured within the image. For example, both FIGS. 5 ( a ) and 5 ( b ) include regions of shadow 32 . In FIGS. 6 ( a ) and ( b ), the solid line 34 represents the gray-scale profile in a vertical direction in the corresponding image in FIG. 5 . It can be seen that the average gray scale intensity 34 generally increases from left to right in FIG. 6 , corresponding from top to bottom in FIG. 5 , due to the lighting conditions.
Additionally, the image in FIG. 5 ( b ) includes a portion of the desktop surface 14 on which the document 18 is resting, which further complicates the gray-scale profile.
To equalize the image, the image is divided into segments which are processed to de-emphasize background effects. In this embodiment, the image is divided into strips perpendicular to the scan direction, i.e. in rows and columns. The width of each segment is typically about 60 pixels, although this can vary in other embodiments. A local average of the pixel value (over a 121 pixel width) is calculated and is subtracted from the pixels in the segment. The local average value will vary according to variation in the local tones and shades, to de-emphasize the unwanted “background” effects, and thereby emphasize the more important foreground text “detail”.
At step 36 , the gray-scale profiles are thresholded to binarize the gray-scale profiles, to distinguish the pixels of the characters from the background. This can either be done by comparing the pixel values to an absolute threshold value, or by detecting changes in the pixel values above a certain delta-threshold. In order to be fully versatile, in this embodiment, the process is repeated for several different thresholds, and the results from each threshold are processed to determine which provides the most reliable result (according to a confidence or quality factor Q explained in more detail below).
In the case of the Philips Vesta Pro camera, which generates an 8-bit gray-scale output, four different delta-threshold values are used (preferably 2, 3, 5 and 8 gray-levels). It will be appreciated that a low delta-threshold value is more “sensitive” for detecting faint text colors, but is also more prone to noise. A higher delta-threshold value is less prone to noise, but might not detect faint text detail reliably.
It will be appreciated that the threshold values used in this embodiment for thresholding a profile, are relatively small, compared to the contrast between foreground and background gray-levels in the original image (which is typically a contrast of at least 50 gray-values). This is because a value from a profile is an average of the gray-values along a line through the image. Such a line typically contains more background points than foreground points even if it goes through the middle of a text line. Therefore, the difference between profiles through text lines, and profiles through white-space, is generally much less then the difference between foreground and background gray-levels, thus requiring the threshold values to be smaller to differentiate two such profiles.
In FIGS. 6 ( a ) and ( b ), a “typical” thresholded profile is represented by the broken line 38 . A high section represents “dark” text pixels, and a low section represents “light” paper background pixels. (For the sake of clarity only one thresholded profile is shown, although it will be appreciated that the several different threshold values used will each produce its own profile shape).
At step 40 , the thresholded profiles are processed into a run-length histogram. Each “bin” in the histogram (horizontal axis) represents a run-length of similar pixels. The vertical axis represents the number of “runs” having that run-length. FIGS. 7 ( a ) and ( b ) illustrate the run-length histograms for the respective thresholded profiles in FIGS. 6 ( a ) and ( b ).
It will be appreciated that steps 36 and 40 may be combined into a single step, but they are described here separately for the sake of explanation.
The run-length histograms contain peaks which represent the frequently occurring “runs” of adjacent pixels in the images, corresponding to characteristic “stroke” lengths in the characters, as explained above. If desired, a characteristic character height may be determined simply by selecting the highest value. For example, in FIG. 7 ( b ), there is a clear peak value 42 , which does correspond to the mean character height. (It will be appreciated that such a high peak would not occur in the histogram for the horizontal direction).
However, although not apparent in FIG. 7 ( b ), there are several factors which may confuse the histogram, and the selection of the appropriate peak:
(a) The peaks from the different histograms for different threshold values might not correspond. Therefore, a selection needs to be made of which peak to use as the “best” peak.
(b) A peak in the run-length histogram does not always correspond to the character height. When text is scanned at high resolution relative to its font size (FIG. 5 ( a )), a sort of “resonance” phenomenon is observed in the histogram (FIG. 7 ( a )). It is common to see one or more peaks 44 in the histogram for short run-lengths that correspond to the width of individual strokes, as well as a peak 42 for long run-lengths that corresponds to the height of the characters. The short run-length peak(s) 44 may often be larger than the long run-length peak 42 (although in FIG. 7 ( a ) it is just lower, due to sparseness of the histogram). A selection needs to be made of which peak to use.
(c) Given two images of the same size in pixels, one of high resolution (FIG. 5 ( a )), and one of low resolution (FIG. 5 ( b )), it is expected that there will be more text lines in the low resolution image, leading to higher peaks. For the low resolution image, the number of text lines is smaller, leading to generally lower peaks.
In the present embodiment, these issues are addressed by a selection algorithm (step 46 in FIG. 4 ) for selecting a peak based on a confidence or quality factor Q for the peak. The Q factor is calculated for each histogram as follows:
Step 46 a: Identify n(L) being the number of runs observed of length L, which is the maximum n in the histogram (i.e. choose the maximum peak). When several different lengths L achieve this maximum (or achieve a similar maximum within a limited range), then choose the larger or largest value of L. This takes in to account that run-lengths caused by noise or by character-widths tend to be short (i.e. small L), whereas the run length corresponding to the character height is relatively long (i.e. large L).
Step 46 b: Determine a value w being the half-range of the histogram peak: that is, the distance between the closest point to the left and to the right of the peak for which a number of runs less than or equal to n/2 are observed. Let a be a parameter that increases with the amount of runs due to noise in the histogram (parameter a is consider to have a unit of length in pixels).
Step 46 c: If the peak is not:
sufficiently high (for some threshold t high ): n>t high (a+L) and sufficiently sharp (for some threshold t wide ): w<t wide /(a+L) then return Q=0 (confidence is zero for this histogram peak).
Step 46 d: To identify short resonance peaks, then if L is shorter than some threshold L short :L<L short (e.g. the peaks 44 in FIG. 7 ( a )), then try to identify another peak for a longer length, at least kL, for some parameter k>1 (e.g. the peak 42 in FIG. 7 ( a )).
If this longer peak is sufficiently high and sufficiently sharp (i.e. satisfies the tests of step 46 c ), then use this longer peak. Otherwise, use the previously selected peak.
Step 46 e: Return the confidence factor Q=n, the height (population) of the selected peak.
Preferred values for the parameters in the above steps are: a=2.0; t high =74; t wide =0.55; L short =6; and k=3.5. However, it will be appreciated that the parameters may vary for other embodiments.
At step 48 , the histogram having the highest Q factor is chosen. The value L for this peak represents the character height in pixels. It will be appreciated that the four different threshold values create four different histograms each having its own Q factor, and the 90° ambiguity in the skew causes the processing to be repeated in both the horizontal and vertical directions, resulting in a total of 8 different histograms.
At step 50 (FIG. 2 ), a test is carried out to determine the ratio of the determined character height L to an ideal character height for OCR, L ideal , chosen to give a reasonable trade-off between OCR rate and the amount of text that may be fitted within the field of view of the camera. For the Philips Vesta Pro camera, L ideal is preferably 9 pixels. At step 52 , feedback is generated to the user, for example by the generation of an information icon in the computer's display.
Referring to FIG. 8 ( a ), when the ratio is about 1, the camera is positioned at the appropriate height. An “OK” icon 54 is displayed.
Referring to FIG. 8 ( b ), when the ratio is less than 1, this means that the character height is too small, so the user is prompted to move the camera down (or closer to the document 18 ) by the generation of a “down” icon 56 . If the camera has a manually variable zoom setting, then the user may alternatively increase the amount of zoom to achieve the same effect.
Referring to FIG. 8 ( c ), the present embodiment also provides an indication if the character size is too large, in which case the ratio will be greater than a maximum value r max . This maximum value is selected to correspond to a point where either sufficient focus of the camera is near impossible, or where the size of characters would violate assumptions made by subsequent binarization or OCR algorithms. For the Philips Vesta Pro camera, r max is preferably about 6 , corresponding to the camera being 12 cm/2 cm from 10 pt Times new Roman text and scanning resolutions of 140 dpi/840 dpi. If the ratio exceeds r max , then the user is prompted to move the camera up (or further from the document 18 ) by the generation of an “up” icon 58 . Again, if the camera has a manually variable zoom setting, then the user may alternatively reduce the amount of zoom to achieve this distancing.
Referring to FIG. 8 ( d ), if the text height determination algorithm has failed, i.e. all of the histograms have returned a confidence factor of zero, then a blank icon (or a failed icon) 60 is displayed. This may occur if, for example, the document is not a text document.
As a modification of the above embodiment, step 52 may additionally generate a control output (output 62 shown in phantom in FIG. 1 ) for controlling a zoom mechanism of the camera, if the camera has a variable zoom, which can be controlled electronically. This would enable automatic “hands-free” operation of the zoom setting to ensure that documents are scanned at a sensible resolution without the user having to control the camera.
The techniques described above are advantageous in being able to provide reliable results rapidly. When running on a 600 MHz computer 20 , the technique can accommodate about 5 frames per second, which is sufficient to keep up with the incoming video frame rate. Moreover, the techniques are versatile and robust in being applicable to a wide range of documents, without making severely limiting assumptions about the text or text layout.
In the above embodiment, the processing to determine OCR suitability is performed in a computer 20 to which the camera 12 is coupled. In a second embodiment, the processing is carried out in the camera itself, to provide a more versatile arrangement for portable hand-held cameras.
Referring to FIGS. 9-11 , a digital camera 70 comprises a case 72 on which are mounted an objective lens 74 , an electronic display 76 (such as an LCD display), a shutter release switch 78 , and one or more other manually operable control buttons 80 . The case 72 houses a photoelectric imaging device 82 (such as a CCD) for capturing digital images, and which communicates with other internal circuitry via an information bus 84 .
The internal circuitry also includes a processor 86 (which may be a microprocessor or a microcontroller), a display driver 88 for driving the display 76 , and a memory 90 . The memory may include one or more of semiconductor memory, optical memory and magnetic memory. The bus 84 is also coupled to an interface port 92 through which data can be uploaded from the camera, or downloaded into, the camera, and to an audible alarm generator 94 for generating alarms to alert a user to one or more alarm conditions.
In use, operation of the camera is controlled by the processor 86 , which detects user inputs via the shutter release switch 78 and the other controls 80 , and directly controls the capture of a digital image through the imaging device 82 , and the storage of the captured image in the memory 90 . The processor 86 also controls the display driver 88 for generating images on the display 76 . Generally, the display driver 88 can be controlled to display an image obtained from the imaging device 82 (e.g. in a real-time viewfinder mode), or to display previously captured images stored in the memory 90 . The processor 86 also controls any information messages on the display 76 , such as the amount of free memory, or a state of auto-focus. Additionally, the processor 84 controls the generation of the audible alarm generator 94 , for example for generating alarm tone if the camera is not focused.
The processor 86 also performs certain image processing operations on the captured images, and may also control operation of the interface port 92 .
In a similar manner to the first embodiment, one of the operations carried out by the processor 86 is to determine whether a current image (e.g. an image about to be captured) is suitable for subsequent OCR.
FIG. 11 shows the general processing steps required for assessing the suitability of the image for OCR. The process is initiated at step 100 when the processor detects that the user has partially pressed the shutter release button 78 to a “half-pressed position”. (In FIG. 9 , the shutter release button 78 has two outputs, one corresponding to depression to a “half-press” position, and the other corresponding to full depression of the button). At step 102 , an image is captured using the imaging device 82 , and is stored (at least temporarily) in the memory 30 .
At steps 104 and 106 , processing is carried out in the same manner as that of the first embodiment (and so is not described again in detail). In particular, the image is processed to resolve skew (step 104 ) and to identify the character height (step 106 ) on the basis of a most common run-length in a certain direction of the image.
At step 108 , the determined character height is compared with an ideal height, to calculate a ratio of the actual/ideal heights (in the same manner as step 50 of the first embodiment). At step 110 , a feedback icon is displayed to show the camera user whether or not the image is suitable for OCR, or whether adjustment of the camera is needed. The feedback icons are the same as those described above in FIGS. 8 ( a )-( d ).
Additionally, if the image resolution is too small (FIG. 8 ( b )), or too large (FIG. 8 ( c )), or optionally if no determination is possible (FIG. 8 ( d )), then an alarm tone can be generated through the audible alarm device 94 to alert the user.
In a modified form of the above embodiment, the camera includes an electrically controlled zoom lens (denoted by 112 in FIG. 10 ). At step 110 , a control output 114 is generated from the processor to the zoom lens 112 , to adjust the zoom setting if the image is determined to be too small or too large for optimum OCR (in the same manner as the control output 62 in FIG. 1 ).
Although the profiles-based method described previously (for determining the resolution of text in the image) is currently preferred, it will be appreciated that other embodiments may use different methods within the scope of the present invention. The following alternatives are described for the sake of completeness. The detailed steps for implementing such alternative methods will be apparent to those skilled in the art from the description below (taking into account the foregoing detailed description):
Alternative 1
Instead of using profiles, the image may be directly binarized into only black and white pixels. In a similar manner to that of the preferred embodiment, the run lengths of runs of black pixels may be determined and histogrammed. The peaks in the histogram may then be analyzed in a similar manner to that described previously, to approximate the resolution.
Alternative 2
In alternative 1, instead of histogramming the run lengths of black pixels, the binarized image may be processed to locate connected components in the image, and to compute bounding boxes or bounding ellipses around the connected components. The widths, or the lengths of principal axes of the bounding shapes are then computed and histogrammed, and the peaks in the histogram are analyzed as described above.
Alternative 3
The image may be processed to identify one or more predefined shapes in the gray-level image. For example, this may be done by having a predefined dictionary of some gray-level character shapes at various resolutions, fonts, and orientations. Such an approach is practical because it may be necessary only to store the appearances of one or two commonly occurring characters, such as “i” and “e”. The matching process can be accomplished, for example, using the “hit-and-miss transform” such as that described in the reference: D. S. Bloomberg and L. Vincent, “Blur Hit-Miss Transform and its use in Document Image Pattern Detection”, in Proceedings Document Recognition II, SPIE Vol. 2422, San Jose, February 1995, pp. 278-292.
This method could also be applied to a binary image, for example, if the image is binarized into black and white pixels.
The resolution is determined by identifying the most common matching resolution.
Alternative 4
As in the preferred method, gray-scale profiles are computed in the image. However, instead of binarizing the profiles to determine segments that correspond to text lines, an alternative characteristic may be determined. For example, the distance may be computed between the closest neighboring pairs of points where the gradient of the profile exceeds some threshold. It will be appreciated that other characteristics will be apparent to those skilled in the art.
It will be appreciated that the foregoing description is merely illustrative of preferred forms of the invention, and that many equivalents and modifications will occur to those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the appended claims are intended to be broadly construed. | A device and method are described for capturing an image of a document using a digital camera. The invention includes a resolution analyzer for analyzing the resolution of text characters in the image, to assess whether the resolution is suitable for OCR. In one aspect, if the resolution is too small or too large, an indicator is generated to guide the user as to the corrective movement of the camera to improve the resolution for OCR. In a second aspect, an electronic zoom control is controlled to alter the magnification of the captured image, to correct the resolution. In a third aspect, a method is described for analyzing the image to determine the resolution according to the height of text characters in the image. The method includes analyzing the run lengths of pixels in the image to identify a predominant length corresponding to the average character height (in pixels). | 6 |
TECHNICAL FIELD
[0001] The present invention relates to a method for refueling of gas into a pressurized gas tank with repeated adjustment of a target pressure for the refueling,
BACKGROUND OF THE INVENTION
[0002] When gas is filled into a pressurized tank, the compression heat from the compression of the gas causes the temperature of the gas inside the tank and, consequently, also the temperature of the tank material to increase significantly.
[0003] Such gas tanks typically have a certain upper temperature limit. For instance, a hydrogen tank for use in a vehicle normally has an upper temperature limit of 85° C., which may not be exceeded by the hydrogen temperature inside the tank at any time during the refueling of the tank.
[0004] The increase of the temperature of the gas inside the tank is highly dependent on the refueling time, i.e. time used for filling the tank. The longer the refueling time, the more heat energy will be transferred from the gas inside the tank through the tank material to the environments during the refueling. Consequently, a fast refueling results in a higher gas temperature inside the gas tank than a slow refueling.
[0005] In order to avoid that the upper temperature limit is exceeded, the refueling time is normally adjusted so that the upper temperature limit will only be reached in the most extreme case, known as the “hot case”. Thus, if the conditions in the gas tank are not extreme, the temperature of the gas therein will stay below the upper temperature limit at any time during the refueling. The “hot case” conditions are normally calculated from a model taking into consideration different parameters of which the ambient temperature is one of the most important.
[0006] For a gas tank with a fixed volume, the density (p) of the gas therein is directly proportional to the mass of the gas and, thereby, to the amount of gas in the tank. The density of a given type of gas depends only on the pressure (P) and the temperature (T) of the gas.
[0007] Thus, when the temperature and the pressure of the gas within a tank of a well-defined volume is known, the density of the gas and, thereby, also the amount of gas in the tank is completely defined. This means that, if the refueling is stopped at a certain target pressure, the amount of gas in the tank depends on the temperature of the gas.
[0008] The term “State Of Charge” (SOC) is normally used for quantifying the actual amount of gas inside a gas tank. SOC is defined as the ratio between the actual gas density and a nominal density, where the nominal density is the density at the Nominal Working Pressure (NWP) at a certain reference temperature (typically 15° C.). Thus
[0000]
SOC
[
%
]
=
ρ
P
,
T
ρ
NWP
,
15
°
C
.
·
100
(
1
)
[0009] This equation states that the gas tank is full, if the gas density inside the tank equals the nominal density. If SOC exceeds 100%, the tank is overfilled.
[0010] In refueling situations at which the vehicle does not communicate the gas tank pressure and temperature to the refueling station, a suitable stop criterion is needed in order to stop the refueling process at an appropriate stage. Typically, a predefined target pressure is used to stop the refueling before the vehicle tank is overfilled. This target pressure can be defined in several different ways, but typically it depends on the ambient temperature and the start pressure within the gas tank before the refueling. Due to the lack of communication from the vehicle, the tank temperature is unknown, which means that the SOC will also be unknown to a certain extent, even if the refueling is stopped exactly at the predefined target pressure.
[0011] The target pressure is normally defined by calculations and/or measurements prior to the refueling. This means that a number of assumptions, including the refueling time and corresponding refueling time tolerances, have to be made when defining the target pressure. When calculating the target pressure, the so-called “cold case” conditions are used. This means that the target pressure is defined as the pressure which, at the gas temperature resulting from the longest possible refueling time within the defined tolerances, results in an SOC of 100%. If the refueling takes place faster than defined by the “cold case” conditions, the increase of the gas temperature will be larger, and target pressure will be reached and the refueling will be stopped before the SOC reaches 100%.
[0012] As long as the actual refueling time corresponds to the assumed refueling time within the corresponding tolerances, a safe refueling with a gas temperature below the upper temperature limit and an SOC not exceeding 100% is ensured. If, however, the refueling time falls outside the tolerances, problems may occur. If the refueling time is too short, the upper temperature limit may be exceeded, and if the refueling time is too long, the tank may be overfilled.
[0013] This means that, if the refueling is too slow, it has to be stopped before the target pressure has been reached because there is a risk of overfilling the vehicle tank. This is unfortunate and inconvenient for the customer, who would normally rather experience a slow refueling than not having his vehicle refueled at all.
[0014] One of the most likely reasons for slow refueling with the refueling time exceeding the tolerances is low refueling station capacity. Consequently, there is typically a lower limit for the refueling station capacity, below which the refueling station is not able to perform a refueling within the defined refueling time tolerances, and a certain part of the refueling station capacity cannot be utilized. This is both an inefficient and unnecessarily expensive situation.
BRIEF SUMMARY
[0015] The disclosure provides a method for refueling vehicles from a gas refueling station without this above-mentioned disadvantage.
[0016] The present invention relates to a method for refueling of gas into a pressurized gas tank with repeated adjustment of a target pressure for the refueling, said method comprising the steps of: recording starting conditions for the refueling, establishing a mathematical relation between the recorded starting conditions, the actual refueling time passed and the target pressure for the refueling, starting the refueling, and repeatedly calculating the target pressure corresponding to the actual refueling time passed and measuring the nozzle pressure of the refueling station, until the calculated target pressure has been reached.
[0017] The introduction of a repeatedly adjusted target pressure eliminates the need for a lower refueling time tolerance and, thereby, the risk of interruption of the refueling due to time-out because this time tolerance is exceeded. This means that the full capacity of the refueling station can be utilized, which is beneficial for the operator thereof. Furthermore, it is beneficial for the customer, who will obtain a full gas tank even if the capacity of the refueling station is low.
[0018] In an embodiment of the invention, the pressurized gas tank is a gas tank of a vehicle.
[0019] In an embodiment of the invention, the refueled gas is hydrogen.
[0020] In an embodiment of the invention, the target pressure is calculated at equal time intervals controlled by a timer.
[0021] In an embodiment of the invention, the time interval between two subsequent calculations of the target pressure is between 0.1 seconds and 10 seconds, preferably between 0.5 seconds and 5 seconds, most preferably between 1 second and 2 seconds.
[0022] Calculating the actual target pressure at equal time intervals within the described ranges is advantageous for obtaining a safe and reliable refueling procedure without any risk of overfilling the gas tank.
[0023] In an embodiment of the invention, the recorded starting conditions for the refueling included the ambient temperature and/or the gas tank starting pressure.
[0024] Tests have shown that recording the ambient temperature and the gas tank starting pressure is sufficient for obtaining reliable mathematical relations between the actual refueling time and the target pressure.
[0025] In an embodiment of the invention, the mathematical relation is a linear function, a logarithmic function or a polynomial-regression function correlating the target pressure to the actual refueling time.
[0026] In an embodiment of the invention, the mathematical relation expresses the target pressure as a function of the actual refueling time and comprises one or more coefficients depending on the recorded starting conditions for the refueling.
[0027] In an embodiment of the invention, the coefficients of the mathematical relation is found by looking up in a table after recording the starting conditions for the refueling, the coefficients in the table being found by making a number of refueling simulations with different starting conditions and refueling times.
[0028] In an embodiment of the invention, linear interpolation, logarithmic interpolation or other types of interpolation between the coefficients in the table is used for finding the coefficients corresponding to the actual starting conditions for the refueling and the actual refueling time.
[0029] As long as there is a consistent relation between the chosen representation and the simulated target pressure values, there are no constraints on the methods used for representing the target pressure values.
BRIEF DESCRIPTION OF THE FIGURES
[0030] A few exemplary embodiments of the invention is described in more detail in the following with reference to the figures, of which
[0031] FIG. 1 illustrates schematically the time-pressure curve for a gas tank during hot and cold refueling, respectively,
[0032] FIG. 2 illustrates an example of a refueling window for a hydrogen refueling,
[0033] FIG. 3 a illustrates schematically the time-pressure curve for a gas tank during refueling using methods known in the art,
[0034] FIG. 3 b illustrates the same curve as FIG. 3 a with refueling time tolerances added,
[0035] FIG. 4 a illustrates schematically a time-pressure curve for a gas tank during slow refueling using a method according to the invention,
[0036] FIG. 4 b illustrates schematically a time-pressure curve for a gas tank during fast refueling using a method according to the invention,
[0037] FIG. 5 illustrates schematically the time-pressure curves for three different refueling simulations,
[0038] FIG. 6 illustrates schematically the relations between the refueling time and the target pressure for three different starting pressures, and
[0039] FIG. 7 is a flow chart of a refueling procedure according to an embodiment of the invention.
DETAILED DESCRIPTION
[0040] FIG. 1 illustrates schematically the time-pressure curve for a gas tank during hot refueling HR and cold refueling CR, respectively.
[0041] The two curves HR, CR illustrate the time-pressure relationships for a first refueling, which increases the tank pressure from a given start pressure Pstart to a given end pressure Pend during a refueling time beginning at t_start and ending at t_hot, and for a second refueling with the same start pressure Pstart, end pressure Pend and start time t_start but a later end time t_cold, respectively.
[0042] The time-pressure curve relating to the first and fastest refueling is marked with the letters HR (hot refueling), whereas the time-pressure curve for the second and slower refueling is marked with the letters CR (cold refueling). This is due to the fact that, if the refueling time is shorter, less time is available for heat energy to be transferred from the gas through the tank material to the environments, and the temperature increase in the gas during the refueling is larger.
[0043] This has to be taken into consideration when refueling a gas tank, because most gas tanks have an upper temperature limit (normally 85° C.), below which the temperature of the gas within the tank must be kept at all times. Furthermore, gas tanks also have an upper pressure limit, which may not be exceeded by the gas within the tank.
[0044] Together with the requirement that the State Of Charge (SOC) as defined above must not exceed 100%, the temperature and pressure limitations of the gas tank define a so-called refueling window for a given gas tank. FIG. 2 illustrates an example of such a refueling window for hydrogen refueling of a 70 MPa tank with an upper pressure limit of 87.5 MPa.
[0045] FIG. 2 illustrates how situations with overpressure OP and overheat OH occur, if the upper pressure limit of 87.5 MPa and the upper temperature limit of 85° C., respectively, are exceeded. Furthermore, the line SOC100 indicates the corresponding values of the gas temperature and pressure at which the State Of Charge is exactly 100%, corresponding in this case to a nominal density of the hydrogen of 40.2 kg/m 3 at 15° C. If, for any given temperature of the gas, the pressure of the gas is higher than indicated by the SOC100 line, the gas tank is overfilled OF.
[0046] In situations where the vehicle does not communicate the pressure and temperature of the gas in the tank to the refueling station, a stop criterion is needed for stopping the refueling before the vehicle tank is overfilled (SOC>100%). Typically, a predefined target pressure Ptarget depending on the ambient temperature and on the gas tank start pressure Pstart before the refueling is used. Thus, the end time for the refueling t_end is defined at the time at which the pressure of the gas within the tank reaches the target pressure Ptarget as indicated schematically in FIG. 3 a . However, as the temperature of the gas within the tank is unknown in the situation without communication from the vehicle, also the actual State Of Charge is unknown to a certain extent, even if the refueling is stopped precisely when the predefined target pressure Ptarget has been reached.
[0047] In systems known in the art, the target pressure Ptarget is defined by calculations or test prior to the refueling. This means that a number of assumptions have to be made, including the refueling time and corresponding refueling time tolerances LRTT, URTT as illustrated schematically in FIG. 3 b.
[0048] This figure corresponds to FIG. 3 a with the addition of a lower refueling time tolerance LRTT and an upper refueling time tolerance URTT. The upper refueling time tolerance URTT defining the shortest allowable refueling time and, thereby, the fastest allowable refueling is chosen to ensure that the gas tank is not overheated (the so-called “hot case” assumption). The lower refueling time tolerance LRTT, on the other hand, defines the longest allowable refueling time and, thereby, the lowest possible final gas temperature, known as the “cold case”. This cold case is used for defining the target pressure Ptarget, which is therefore the gas pressure which, in combination with the lowest possible final gas temperature results in a State Of Charge of 100%. Thus, the combination of the refueling time (including lower and upper tolerances LRTT, URTT) and the target pressure ensures a safe refueling without neither overheating nor overfilling of the gas tank.
[0049] However, a consequence of using a lower refueling time tolerance LRTT is that, if this lower refueling time tolerance LRTT is exceeded, the refueling has to be stopped because there is a risk of overfilling the vehicle tank. Stopping the refueling because it is too slow is unfortunate and inconvenient for the customer, who typically prefers a complete (although slow) refueling rather than an incomplete refueling of the vehicle tank.
[0050] One of the most likely reasons for exceeding the lower refueling time tolerance LRTT is low refueling station capacity resulting in a slower refueling. This means that, typically, there will be a lower limit for the refueling station capacity below which no refueling can be done. Consequently, a certain part of the refueling station capacity cannot be utilized, which is inefficient and adds unnecessary expenses to the operation of the refueling station.
[0051] The present invention addresses this problem by making the target pressure Ptarget dependent on the actual refueling time in addition to the ambient temperature and the vehicle tank start pressure, thereby eliminating the need for a lower refueling time tolerance LRTT. Thus, the target pressure Ptarget is no longer a fixed value defined prior to the refueling. Rather, it is adjusted continuously during the refueling as indicated schematically in FIGS. 4 a and 4 b for a slow and a fast refueling, respectively. As can be seen from FIGS. 4 a and 4 b , the target pressure Ptarget is constant until the starting time t_start of the refueling, because the adjustment of the target pressure Ptarget takes place only during the actual refueling, i.e. when gas is flowing into gas tank.
[0052] The upper refueling time tolerance URTT is still relevant for avoiding an overheat situation and also for defining the shortest possible refueling time for which the target pressure Ptarget is defined. The cold case assumptions also still have to be considered for avoiding overfilling of the vehicle tank. However, rather than considering only a single refueling time, a refueling time range has to be considered. Optimally, this refueling time range should stretch from the upper refueling time tolerance URTT (defining the fastest possible refueling according to the hot case assumption) to an infinitely long refueling time. For practical reasons, however, the refueling time must be limited either by decreasing the target pressure or by other features of the refueling station.
[0053] In order to be able to define the target pressure Ptarget in dependency of the ambient temperature, the gas tank starting pressure Pstart and the actual refueling time, several refueling simulations are needed to create an overview of the relations between these parameters. All these simulations are based on the cold case assumptions, meaning that the stop criterion is a SOC of 100%. Thus, each of the refueling simulations will stop when 100% SOC is reached and the end pressure Pend is recorded as the target pressure Ptarget for that particular refueling simulation. FIG. 5 illustrates schematically how three different end pressures P 1 , P 2 , P 3 are recorded for three simulations reaching 100% SOC after refueling times t 1 , t 2 and t 3 , respectively.
[0054] In order to cover the relevant sample space, each of the three parameters (gas tank starting pressure, ambient temperature and refueling time) must be varied with appropriate steps across specified ranges, while any other parameters are kept constant. For instance, for constant gas tank starting pressure and ambient temperature, variation of the refueling time accounts for different temperature developments of the gas in the tank (longer refueling time results in lower gas temperature and vice versa).
[0055] For refueling of a 35 MPa hydrogen tank, the ranges and steps can, for instance, be defined as follows:
Gas tank starting pressure [MPa]: 2; 10; 20; 30 Ambient temperature [° C.]: −20; −10; 0; 10; 20; 30; 40 Refueling time [s]: 100; 150; 200; 250; 500; 750; 1000
[0059] Similar ranges and steps can be defined for a 70 MPa refueling, as the present invention is independent of the nominal working pressure of the pressure tank.
[0060] In the above example, 4 different starting pressures, 7 different ambient temperatures and 7 different refueling times results in a total of 4*7*7=196 simulated refueling and, consequently, 196 different target pressure values.
[0061] For a simpler example with 3*3*3=27 simulated refueling, the results may be presented in a table like the following:
[0000]
Tamb,1
Tamb,2
Tamb,3
Pstart
t_refueling
Pend
SOCend
Pend
SOCend
Pend
SOCend
Pstart,1
t1
Pend,1
100%
Pend,10
100%
Pend,19
100%
Pstart,1
t2
Pend,2
100%
Pend,11
100%
Pend,20
100%
Pstart,1
t3
Pend,3
100%
Pend,12
100%
Pend,21
100%
Pstart,2
t1
Pend,4
100%
Pend,13
100%
Pend,22
100%
Pstart,2
t2
Pend,5
100%
Pend,14
100%
Pend,23
100%
Pstart,2
t3
Pend,6
100%
Pend,15
100%
Pend,24
100%
Pstart,3
t1
Pend,7
100%
Pend,16
100%
Pend,25
100%
Pstart,3
t2
Pend,8
100%
Pend,17
100%
Pend,26
100%
Pstart,3
t3
Pend,9
100%
Pend,18
100%
Pend,27
100%
[0062] Typical target pressure values range from 30-40 MPa for a 35 MPa hydrogen refueling and from 62-78 MPa for a 70 MPa hydrogen refueling.
[0063] Data sets like the above relate the target pressure Ptarget to the gas tank starting pressure, the ambient temperature and the actual refueling time. Plotting the target pressure Ptarget as a function of the actual refueling time t 1 , t 2 , t 3 for different gas tank starting pressures at a given ambient temperature reveals that there is a consistent relation between the target pressure Ptarget and the refueling time t 1 , t 2 , t 3 .
[0064] FIG. 6 illustrates schematically such a relation between the target pressure Ptarget and the refueling times t 1 , t 2 , t 3 at a given ambient temperature for three different gas tank starting pressures represented by the symbols x, Δ and □, respectively. Thus, for each ambient temperature step and each gas tank starting pressure, correlations can be made that relate the target pressure Ptarget to the actual refueling time t 1 , t 2 , t 3 . This results in a number of different functions for each ambient temperature.
[0065] In other words, the target pressure Ptarget can be expressed as a function of the actual refueling time, wherein coefficients of the function depend on the ambient temperature and the gas tank starting pressure. These functions may be linear, logarithmic, polynomial-regression functions or similar mathematical expressions, such as for instance the following logarithmic function:
[0000] f ( t _refueling)= a x,x ·ln( t _refueling)+ b x,x (2)
[0066] The number of coefficients depend on the function which best represents the correlation between the simulated target pressure values Ptarget and refueling times t 1 , t 2 , t 3 . The coefficients may be presented in a table like the following:
[0000]
Target pressure function coefficients, f(t_refueling)
Pstart, 1
Pstart, 2
Pstart, 3
Pstart, 4
Pstart, 5
Tamb, 1
a 1, 1 ,
a 1, 2 ,
a 1, 3 ,
a 1, 4 ,
a 1, 5 ,
b 1, 1 , . . .
b 1, 2 , . . .
b 1, 3 , . . .
b 1, 4 , . . .
b 1, 5 , . . .
Tamb, 2
a 2, 1 ,
. . .
. . .
b 2, 1 , . . .
Tamb, 3
a 3, 1 ,
. . .
b 3, 1 , . . .
Tamb, 4
a 4, 1 ,
. . .
b 4, 1 , . . .
Tamb, 5
a 5, 1 ,
. . .
. . .
. . .
. . .
b 5, 1 , . . .
[0067] Interpolations (linear, logarithmic or similar) can be used for finding coefficients corresponding to ambient temperatures and gas tank starting pressures between the ones used in the simulations.
[0068] A flow chart of a refueling procedure according to an embodiment of the invention using the logarithmic target pressure function defined by Equation 2 above is shown in FIG. 7 . This flow chart comprises five method steps S 0 -S 4 and a single decision step T 1 :
[0000] S 0 : Start of refueling procedure
S 1 : Prepare the refueling
Record the ambient temperature Tamb. Record the gas tank starting pressure Pstart. Look-up the target pressure function coefficients a x,x and b x,x corresponding to the recorded ambient temperature Tamb and gas tank starting pressure Pstart in a table. If necessary, interpolate between the coefficients in the table to define the correct coefficients.
S 2 : Start the refueling
Start the refueling. Start a timer measuring the actual refueling time t_refueling.
S 3 : Calculate the target pressure
Wait for a predefined period of time (for instance 1 second). Calculate the actual target pressure Ptarget corresponding to the actual refueling time t_refueling using the equation:
[0000] P target= a x,x ·ln( t _refueling)+ b x,x
[0000] T 1 : Decision step:
Measure the actual nozzle pressure of the refueling station. If the actual target pressure P is reached, continue to step S 4 . Otherwise, return to step S 3 .
S 4 : End of refueling procedure
[0079] In the above example, the target pressure function coefficients are looked up in a 2-dimensional table. In other embodiments, coefficient tables with higher dimensions can be used, or a mathematical function calculating the target pressure directly from the ambient temperature, the gas tank starting pressure and the actual refueling time without the above-described table based approach may be used:
[0000] P target= f ( T amb, P start, t _refueling) (3) | A method for refueling of gas into a pressurized gas tank with repeated adjustment of a target pressure (Ptarget) for the refueling is disclosed, said method comprising the steps of: recording starting conditions for the refueling, establishing a mathematical relation between the recorded starting conditions, the actual refueling time (t_refueling) passed and the target pressure for the refueling, starting the refueling, and repeatedly calculating the target pressure corresponding to the actual refueling time passed and measuring the nozzle pressure of the refueling station, until the calculated target pressure has been reached. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to an openable guide for sewing machines for attaching circular elastic bands or rings to garments. The guide includes a folding means consisting of two opposed elements which are separatable from one another and which are operatively interconnected. One of these elements is connected to a control means which is biased toward a position in which the two elements are disposed in contiguous relation whereby their inner surfaces form a shaped channel within which an elastic ring forming the band is caused to slide. The control means is actuated in opposition to a biasing means and is effective in separating the two elements for the purpose of completing the sewing operation of one band and to facilitate the insertion of another elastic ring to be sewn onto the next workpiece.
In the manufacture of certain types of garments, more particularly, those having an elastic waist band, it is common knowledge to sew a closed elastic ring onto a garment which has been folded along its edges to form a belt with an internal cavity which, if necessary can be used to incorporate an additional piece of elastic. The operations of folding and attaching the belt to the garment are effected simultaneously be opposed folding guides that are selectively separable so as to permit insertion of elastic ring between the open elements of the guide and to complete the final portion of each sewing operation prior to removing the sewn garment from the machine.
It is necessary for the guides intended for this type of work to be separable because the elastic rings as such possess neither a beginning nor an end and it is therefore impossible to insert them in the guide in the conventional manner and the two edges of the elastic ring must be inserted within the two elements forming the shaped channel of the folding device along a section of corresponding length to the guide per se. As mentioned above, guides which are formed to define opposed channels that are located in an accessible position are known but they have certain limitations considered to be undesireable.
With certain types of conventional guides only one of the component elements is movable with respect to the other which remains fixed in the zone in which the elastic ring is slidable during the stitching operation. As a result, the available space between the two elements is limited making it difficult to insert a ring to be sewn which must be arranged therein in accordance with its width. The stationary element which is not movable from its fixed position obstructs the feed movement which the sewing machine operator performs with one hand during the final stages of the sewing operation. In other types of known guides the stationary element is formed by two members in such a way that the upper portion which forms a part of the channel in which the elastic ring slides, can be raised by tilting it outwardly. A counterbalanced handle is provided for tilting this upper portion of the stationary element.
The presence of a handle projecting from the upper part of the guide and the face that this portion of the guide is manually displaceable is considered to be a desireable feature. However, even with this feature it is not possible to overcome the limited space created by the size of the fixed portion which is fixed in the zone through which the elastic ring is caused to advance. With another conventional form of guide both of the opposed elements of the guide are horizontally movable with respect to one another, one part moving in one direction and the other in the opposite direction.
However, this form of guide also has its disadvantages due to the fact that the width of the passage cannot be increased so as to simplify the passage to feed the workpiece by the operator and at the same time minimize the height of the unit formed by the two elements of the guide.
There is no possibility of increasing the mutual displacement of these elements due to the fact that their movements are linear. If mechanisms were designed to provide additional displacement such mechanisms would require an excessively large lever system.
The object of the present invention is to obviate the above disadvantages by providing maximum freedom in the zone in which the guide according to the invention is operative and also to ensure that when the guide is open, the half channels provided in each of the elements forming the guide are located in the most advantageous position for receiving the edges of the elastic ring.
The technical problem to be solved in achieving this object is that of providing a guide of the aforementioned type in which the two opposed elements in addition to being movable with respect to one another for the purpose of inserting the elastic ring are also capable of reducing the height of the guide in the zone located forwardly of the sewing machine's presser foot.
SUMMARY OF THE INVENTION
The guide according to the invention is provided with a pair of opposed folding elements mounted on support members individually supported for pivotal movement with the axes thereof being disposed parallel to the direction of advancement of the workpiece. The elements are simultaneously moveable in opposite directions to one another about their respective horizontal axis by a guide control means. When separated one from the other these elements are disposed in an inclined position which is lower than the position of said elements when they are in contact or their so-called closed position. The open or inclined position facilitates insertion of the edges of the elastic rings in the folding channels of these elements.
The most important feature provided by the present invention is that which is derived from the arched movement effected by the two folding elements forming the guide as they are separated one from the other.
When the support members are rotated slightly, they are displaced largely horizontally relative to the folding elements carried thereon.
As a result of the aforementioned rotation, the folding elements are not only moved into a lower position through rotation of the support members but the two half channels forming a part thereof which are adapted to receive the sides of the elastic ring are also inclined.
This feature substantially improves the task of inserting the edges of the elastic ring which are guided by the operator during the preliminary operations, and the ring assumes an arched shape over its entire width with its edges acquiring the same inclination as the half channels into which they are guided.
Other objects, features and advantages of the present invention will be made apparent in the following detailed description thereof provided with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a sewing machine showing a guide according to the invention applied thereto.
FIG. 2 is a sectional view of the guide taken along line 11--11 in FIG. 1.
FIGS. 3 and 4 are views similar to FIG. 1 showing the guide in both its closed and open positions.
FIG. 5 is a perspective view of the pivotable support members for the guide showing a manually operable control means for actuating the support members.
FIG. 6 is a view similar to FIG. 5 but showing a pneumatic control means for actuating the support members.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 the guide according to the invention is identified generally by numeral 10 and is mounted on a sewing machine having a base 11 the upper surface of which defines a workpiece support surface 12. An upright support 13 extends upwardly from the base to support a bracket arm (not shown) that terminates in a known form of head 14. A conventional needle bar 15 and a presser bar 16 are slidably mounted in the head 14, and extend downwardly therefrom. The needle bar 15 supports a number of needles 17 which are operatively associated with the conventional lower sewing elements (not shown) with which they cooperate to form stitches. The presser bar 16 has a presser foot 18 assembled thereon which cooperates with the conventional feed element (not shown) that is adapted to advance the workpiece during stitch formation.
The sewing machine is also provided with an additional rear feed means 19 which is intended for use when sewing elastic materials. An elastic ring 22 folded to form a belt for attachment to garments such as underpants and shorts extends between rollers 20 and 21 of the rear feed means 19.
The sewing machine also includes an upper tension roller 23 which is adjustably mounted on a slotted arm 24 which permits this roller to be selectively located at different distances from the base 11 so necessary adjustment can be made to accommodate different size elastic rings.
Additionally the sewing machine is provided with a tension roller 25 which is disposed in the lower part of the base 11 and serves to complete the path for the elastic ring.
The tension rollers serve to stretch the elastic ring 22 so that it can be sewn onto the garment in the fully elongated state. The garment itself is also stretched so that when the stitching operation has been completed and the workpiece finished, it will be elastically extensible thereby eliminating the possibility of tears developing at the seams.
Due to the fact that the belt or band for the garments is formed as a closed ring and which accordingly does not have an end or starting point, the guide 10 which is used to fold the ring along its edges to produce a belt, is adapted to be opened to permit insertion of said edges into the shaped internal channel of said guide which provides the ring with the desired fold.
The use of a guide which can be selectively opened is also necessary for finishing the sewing operation when the belt has nearly completed its rotation about the base of the machine and the starting point of the seam is approaching the mouth of the guide. As the sewn belt cannot slide through the shaped channel, the guide must be opened so as to allow the belt to slide outside of the guide until the final portion of the sewing operation has been completed.
The guide 10 is located on the workpiece support surface 12 forwardly of the presser foot 18 and to permit the garment, to which the belt 22 is being attached, to slide freely. A plate 26 having a curved leading edge 27 is provided immediately adjacent to said guide.
Additionally the guide 10 is provided with a control means 28 that is selectively operable to open the guide and hold it open during the initial and final sewing operations.
Referring now to FIGS. 2 and 3, the guide 10 includes two opposed elements 29 and 30 the internal surfaces of which define a shaped channel 31 which forms the shape of the cross-section of the elastic ring 22 to be attached to a garment "A". The shaped channel 31 is formed by the combination of the internal surfaces of both the elements 29 and 30 with each of the latter defining a half channel within which the edges of the elastic ring 22 are inserted during the initial sewing stage when the elements 29 and 30 are in their open position. To permit correct positioning of the ring 22 on the garment, the lower part of the lefthand element 29 is provided with a passage 32 defined by a vertical wall 33 (FIG. 2) against which the garment "A" is caused to slide during the sewing operation.
When an elastic ring 22 for forming the belt or band is to be inserted in the guide 10, the latter is opened by moving the elements 29 and 30 apart from one another as shown in FIG. 4, thereby breaking the continuity of the shaped channel 31 and rendering the two half channels 34 and 35 readily accessible. The half channel 35 is formed by the combination of the righthand element 30 and the central portion 36, that is an integral part of the lefthand element 29, and which is positioned within said element 30 when the guide is closed. The guide 10 is opened by moving an arm 37 of the control means 28 to the left as viewed in FIG. 5 which effects axial movement of an actuating rod 38 which, in turn compresses a coil spring 39 by means of a ring 40 fixed on the rod 38.
The coil spring 39 is provided to return the elements 29 and 30 to the closed position corresponding to the rest position of the guide when the force exerted on the control means 28 has been terminated. Referring now to FIG. 5 the control means 28 also includes a transversal shaft 41 that is operatively connected to a downwardly extending rod 42. This rod 42 supports a plate member 43 which the operator actuates with her knee in order to open and close the guide 10.
The rod 38 is supported for axial movement in aligned apertures provided in a support member 44 and has a connector 45 fixed on one end that includes a laterally extending pin 46 which is adapted to lock said rod 38, upon full movement to the left, in that position corresponding to the open position of the guide. The retaining means is identified by numeral 47 and includes a latch member 48 which is pivotally mounted on a pin 49 which is fixed in and extends from a bracket 50 assembled in the support member 44.
A spring 51 is mounted on the pin 49 with one of its arms 52 being diposed so as to apply a clockwise biasing force on the latch member 48. The other arm of spring 51 is identified by numeral 53 and is fixed in a conventional manner to the bracket 50.
The latch member 48 is provided on that end adjacent the pin 46 with an inclined face 54 on which said pin 46 is adapted to slide whenever the rod 38 is moved towards the left. This movement causes upward pivotal movement of the latch member 48 causing the pin 46 to move beyond the inclined face 54 and to enter into a central opening 55 provided in said latch member 48 which is formed intermediate the ends of the latter. The opening 55 serves to permit the latch member 48 to pivot back to its initial position under the influence of spring 51 and to engage the pin 46 in a manner so as to prevent rod 38 from effecting its return movement towards the right.
One end of a connecting rod 56 is pivotally connected to a support means 57 of the guide 10 and the opposite end is pivotably mounted on the connector 45 by means of connecting rod 56. The axial movements of the rod 38 are transmitted to the support means 57 in a manner to cause pivotal movement of the latter.
More specifically the connecting rod 56 is connected to a first support 58 which is pivotably mounted in a substantially vertical position on a horizontal pin 59 that is attached to the support member 44 and extends therefrom parallel to the direction in which the workpiece is advanced
A second support 60 is also disposed in a substantially vertical position and is pivotably mounted on a horizontal pin 61 which extends parallel with and is spaced apart from pin 59. Like pin 59 pin 61 is also attached to the support member 44.
The movements of the first support 58 are transmitted to the second support 60 by means of the transmission device consisting of an arm 62 integrally formed on said first support which includes a laterally extending pin 63 operatively disposed in a groove or bifurcation 64 provided in an integrally formed arm 65 of said second support 60. It can easily be seen that any pivotal movement of support 58 on pin 59 is transmitted to support 60 causing the latter to pivot in the opposite direction of said support 60. With element 29 being mounted on support 58 and element 30 of the guide 10 being mounted on the support 60, the opening and closing of the guide 10 can be selectively controlled.
When the pin 46 is caused to enter the central opening 55 after the rod 38 has been moved to the left, said pin 46 becomes located in the space identified by numeral 66 thus preventing the return of rod 38 to its initial position.
With an additional movement toward the left on the part of the rod 38 the pin 46 is caused to move beyond a projecting portion 67 of the latch member 48 and to a position of alignment with a groove 68 provided behind the projecting portion 67. The base of the groove 68 is inclined with the deeper portion disposed on the lefthand side of the opening 55 and the shallower portion of the righthand side. When the pin 46 becomes aligned with and enters this groove, it moves the latch member 48 outwardly so as to displace it from its normal position. This movement causes pin 46 to be disengaged from the latch member 48 and the rod 38 and then move to the right to its initial position under the influence of the coil spring 39. The movement of the rod 38 towards the right causes elements 29 and 30 to pivot toward each other so as to close the guide 10.
The control means can also be pneumatically actuated such as by a plunger 69 slidably mounted in a conventional cylinder 70 which is pivotally mounted on the support member 44 by means of a pin 71 (FIG. 6).
In FIG. 6 the rod 38 is shown forming the stem of the plunger 69 and the coil spring 39 disposed so as to urge said rod 38 toward its rest position. The coil spring 39 is disposed within the cylinder 70 intermediate its end wall and the plunger 69 such that when the latter is displaced by the compressed air entering the cylinder through a conduit 72 it compresses said coil spring in the same manner as the ring 40. Additionally the coil spring 39 is effective in moving the plunger 69 and rod 38 to the right of their rest position when the force of the compressed air is terminated.
The open position of the guide 10 is obtained by continuously directing compressed air into the cylinder 70.
By exerting slight pressure on a knob 73 of a control valve 74, the compressed air which is supplied through the supply line 75 via a conventional group filter-manometer-lubricator unit 76 which is located in the conduit 77, is able to pass into the control conduit 78 subsequent to temporary switching of the control valve 74, thus activating a flip-flop valve 79. The flip-flop valve 79 is located in the circuit supplying the cylinder 79 for it can maintain the position determined for it by means of the control valve 74 for an indefinite period of time without having to keep the knob 73 depressed. When open, the flip-flop valve 79 allows compressed air contained in the conduit 77 to pass into a conduit 80 that is connected to a stroke regulator 81, which is in turn connected to the conduit 72 leading to the cylinder 70.
The stroke regulator 81 is adapted to permit compressed air to move unrestricted to the cylinder 70 so as to obtain rapid opening of the guide 10 and to regulate the rate at which the compressed air contained in the cylinder is discharged after the supply has been interrupted by the application of pressure on the knob 73 which effects switching of the valve 79.
Consequently, by regulating the return rate of the plunger 69, it is possible to control the closing rate of the guide as desired.
When pneumatic control means are utilized, it is possible to vary the displacement rates of elements 29 and 30, thus providing the advantage of being able to accelerate the operation of removing the finished workpiece from the sewing machine. This is made possible because the guide can be opened rapidly and the operation of inserting another elastic ring is facilitated by the fact that the guide can be closed more slowly, thus enabling the operator to arrange the ring in the shaped channel without interrupting the closing movement of the guide, which is effected automatically by a servo control means.
A further advantage provided by the pneumatic control means is that of controlling the distance the plunger is permitted to move toward the left so as to regulate the width of the opening of the guide 10. To achieve this, a stop 82 (FIG. 6) is provided which is selectively positionable in a slot 83 provided in the support member 44 adjacent the first support 58. The groove 83 extends parallel to the direction of displacement of the rod 38 and depending on the distance of the stop 82 from the support 58, the movements towards the left of the latter, and consequently the movements towards the right of the second support 60 can be controlled as desired.
Although the present invention has been described in connection with a preferred embodiment and a modification thereof, it is to be understood that other 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 the appended claims. | A guide for guiding elastic bands in a sewing machine for attachment to garments having a pair of opposed elements mounted on pivotable support members individual thereto. The combination of the internal surfaces of the opposed elements define a shaped channel for folding and maintaining the bands in the desired configuration for and during attachment to a garment. A control device is operatively connected to the opposed elements to permit selective movement of the latter in opposite directions. The elements can be moved between positions of contiguous relation, which serves to guide the bands and a spaced apart inclined position that serves to complete the final stages of each sewing operation and to facilitate insertion of a new band for the next sewing operation. | 3 |
TECHNICAL FIELD
[0001] The present invention relates to strollers, and, more particularly, the present invention relates to an improved tow-type walking, running or jogging stroller.
BACKGROUND ART
[0002] Jogging strollers (also referred to as running strollers, walking carriages, jogging carriages and running carriages) are a popular means by which adult attendants can take their babies, toddlers and small children along when the adult attendants are engaged in walking, jogging, or running exercises. The vast majority of commercially available jogging strollers are pushed by the attendant. Push-type strollers require that the attendant use one or both of his or her arms and hands to propel and control the stroller during operation. This requirement restricts arm swing that naturally occurs in humans during walking and running. Arm swing during running, at any speed, affects factors such as center of mass; forward propulsion; and various components of angular momentum. Therefore, restricted arm swing can affect critical factors that mediate the biomechanical efficiencies inherent in human locomotion.
[0003] Steering mechanisms employed by push-type strollers may compromise the safety of the child and the attendant at higher travel velocities. Steering designs often employed by push-type strollers include front wheels that swivel or caster to allow the attendant to steer the stroller while maintaining wheel contact with the ground at all times. Similar to shopping cart wheels, the front caster(s) used for push-type strollers tend(s) to “shimmy” as the stroller is propelled at higher velocities and could create lateral instability localized at the front end of the stroller. This instability could result in loss of steering control at increased travel speeds and thus compromise the child's safety. When subjected to uneven travel surfaces or obstacles along the path, such as a pebble, the direction of the affected caster tends to deviate from the path of progression, potentially resulting in abrupt changes in stroller direction that may further compromise control of the stroller. Strollers designed for higher jogging speeds often employ three wheels with a non-caster front wheel. To steer this type of stroller, the front wheel must be lifted away from the ground. This maneuver requires that the runner press downwardly on the rear stroller handle, using the rear wheel axle as a fulcrum by which to lift the front wheel up and away from the ground sufficiently to turn the stroller laterally, either completely or incrementally, in the desired direction. The weight of the stroller and the occupant is borne over the rear axle and is solely dependent on the stability and strength of the attendant's arm(s) to maintain balance during this maneuver. Some manufacturers offer front wheel designs that may be placed in either the fixed or swivel position but recommend that users lock the wheel in the “forward” position when operating the stroller at higher jogging speeds for the safety reasons stated above.
[0004] The vertical load component of known “hands-free” stroller designs result in decreased biomechanical running efficiencies due to the additional vertical load(s) placed on the attendant, and produce a jarring interaction between attendant and carriage (and child) generated by the attendant's movements, especially at higher running velocities.
[0005] When walking, jogging, or running, a person typically exhibits some lateral motion that can be translated to the carriage (and therefore the child passenger) via the tow bar. Control of this motion is especially critical for two wheeled vehicles, given the possibility that the resulting side-to-side carriage motion, as it periodically changes direction of the carriage's inertia (from left to right and right to left), could achieve a resonant frequency that could result in loss of steering control or, at minimum, result in a jarring motion for both the attendant and the child.
[0006] Furthermore, the attendant's walking/jogging/running motion may create anterior/posterior impulses between the attendant and the carriage during operation. In bipedal human locomotion, whether walking or running, the attendant's COG accelerates upon “push off” and decelerates upon “heel contact” of each step. This anterior/posterior acceleration/deceleration is translated to the carriage assembly and occupant via the tow bar—albeit asynchronously. Upon “push off,” the attendant's COG accelerates along the path of progression and the carriage experiences a corresponding acceleration. Upon heel contact, the attendant's COG decelerates. Due to the inertia of the carriage, however, the corresponding carriage deceleration will lag behind that of the attendant's deceleration, thus establishing a cycle by which the acceleration/deceleration of the carriage and attendant will be out of phase. This repetitive action generates a jarring impulse experienced at each end of the tow bar by both the attendant and the carriage at each of the attendant's steps.
DISCLOSURE OF INVENTION
[0007] Disclosed herein is a tow-type two-wheeled jogging stroller that employs a dropped axle design, whereby the carriage frame, wheels, occupant seat and body engaging means are arranged such that the degrees of freedom of each component, relative to each other, are limited to a rotation in the saggital plane about a single axis of rotation, and the load bearing components of the carriage assembly are arranged such that the center of gravity of the carriage load is borne below the single axis of rotation. The body engaging means, comprising a tow bar assembly, a cross bar, an articulated assembly and a waist belt, is configured such that the attendant tows and steers the carriage assembly without the use of the attendant's arms or hands.
[0008] In preferred embodiments, the tow bar assembly provides a resilient means by which the anterior/posterior and medial/lateral impulses generated between the carriage and the attendant during operation are mediated. Thus, as will be described in more detail below, the carriage assembly and tow assembly components of the stroller are arranged to minimize the vertical and horizontal loads borne by the attendant, to attenuate the impulses imparted on the carriage assembly, and to maximize the safety of the child occupant consequential to the mechanical interaction between the carriage assembly and attendant during walking or running.
[0009] In general, embodiments of the invention include a carriage assembly, a tow bar, and a harness. The carriage assembly includes a seat for accommodating a passenger and two wheels having an axis of rotation. The tow bar assembly has first and second ends, the first end coupled to the carriage assembly, and the second end being coupled to the harness, which may be adjustably configured to be connected to the attendant. The components are coupled together such that when the carriage assembly is in use, the COG is located below the axis of rotation of the wheels. Moreover, the seat preferably is positioned such that when a child is seated therein, a combined center of gravity of the child and the carriage assembly is located below the axis of rotation while the stroller is in use. To facilitate positioning the center of gravity below the axis of rotation, the carriage assembly may be provided with two axles, a first axle associated with a first of the two wheels and a second axle associated with a second of the two wheels, the first and second axles being separate and substantially collinear.
[0010] The carriage assembly may include a carriage frame. Preferably, the carriage frame is rotatably coupled to the wheels and adjustably coupled to the seat. More preferably, the carriage frame, wheels, and seat are rotatably coupled together about a single axis of rotation. The carriage frame may define a plurality of connection points configured to be coupled to the seat, the connection points providing a plurality of locations to which the seat can be coupled to the carriage frame. Thus, the seat may be repositioned as desired.
[0011] The carriage assembly may also include an elongate cross bar. Preferably, the cross bar is fixedly coupled to the carriage assembly along the wheel axis of rotation at first and second ends thereof, and rotatably coupled to the tow bar at an intermediate location thereof. The carriage assembly may further include one or more stops to limit the rotation of the cross bar relative to the frame.
[0012] The tow bar preferably is configured to attenuate acceleration of the harness relative to the carriage assembly. To this end, the tow bar may include a first member coupled to the carriage assembly, a second member coupled to the harness, and a damping element coupled to the first and second members. The first and second members are coupled together so as to allow relative movement therebetween, and the damping element is configured to provide resistance to such movement. These elements may be positioned in a variety of ways. For example, the first and second members may be substantially parallel with the damping element being substantially parallel to the first and second members when the tow bar assembly is in a neutral, compressed or extended position. As another example, the first and second members may be substantially parallel with the damping element being substantially perpendicular to the first and second members.
[0013] The combination and assembly of the components disclosed below provide a number of benefits over previous tow-type stroller designs, including without limitation: (1) minimized overall vertical load bearing by the attendant while walking or running; (2) reduced vertical movement as experienced by the carriage assembly occupant; (3) attenuated anterior/posterior impulses experienced by the attendant and carriage assembly occupant; (4) minimized lateral carriage assembly movement imparted by attendant's side-to-side motion during walking or running; and (5) improved occupant safety by means of a seat provided with safety roll bars, which is situated such that the center of gravity is below the wheel axis. The disclosed arrangement of components also provides improved biomechanical efficiency over conventional push-type strollers by permitting natural arm swing during walking/running, as well as improved steering stability at higher jogging/running speeds.
[0014] The major carriage assembly components are configured to permit the seat to be quickly engaged/disengaged from the carriage frame, the distance of the seat's center of gravity to be adjusted relative to the wheel axis, and the tow bar assembly to be quickly engaged/disengaged from the carriage assembly and from the body engaging means located at the rear of attendant's lower back. Furthermore, the wheel assembly may be quickly engaged/disengaged from the carriage frame or may be rotated along an axis perpendicular to wheel hub axis to and about the carriage assembly to substantially reduce the size and volume of the carriage assembly to facilitate easier storage when it is not in use.
BRIEF DESCRIPTION OF DRAWINGS
[0015] The present invention is described with reference to the accompanying drawings, which illustrate exemplary embodiments and in which like reference characters reference like elements. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
[0016] FIG. 1 shows a tow-type stroller in a use position, in accordance with one embodiment of the present invention, while the stroller is being propelled and controlled by an attendant.
[0017] FIG. 2 shows a front view of the carriage assembly of the tow-type stroller of FIG. 1 .
[0018] FIG. 3 shows an exploded view of the connection of the carriage assembly and cross-bar components of the tow-type stroller of FIG. 1 .
[0019] FIG. 4A shows a single seat assembly of the tow-type stroller of FIG. 1 .
[0020] FIG. 4B shows an alternative means of connecting the single seat assembly shown in FIG. 4A to the axle sleeve of the tow-type stroller shown in FIG. 1 .
[0021] FIG. 5 shows a side view of another embodiment of the carriage assembly component of the tow-type stroller of FIG. 1 .
[0022] FIG. 6A shows an exploded view of the carriage assembly of FIG. 5 .
[0023] FIG. 6B shows the detail of a latch mechanism associated with the carriage assembly shown in FIG. 6A .
[0024] FIG. 7 shows an example of a tow bar assembly of the tow-type stroller of FIG. 1 .
[0025] FIGS. 8 a and 8 b show graphs illustrating the states of transition between compression and extension in the tow bar assembly of the tow-type stroller of FIG. 1 .
[0026] FIG. 9 shows an alternate tow bar assembly of the tow-type stroller of FIG. 1 .
[0027] FIG. 10 shows a schematic illustrating the tow bar assembly function when elastic members connected to the tow bar components are arranged to permit an extended neutral zone in the tow bar assembly.
[0028] FIGS. 10 a , 10 b and 10 c show various states of the tow bar assembly of FIG. 9 .
[0029] FIGS. 11 a and 11 b illustrate an example of an alternative crossbow arrangement of a tow bar assembly having a cantilever type spring for creating a neutral compression/extension zone.
[0030] FIG. 12 shows a crossbar component of the tow-type stroller of FIG. 1 .
DETAILED DESCRIPTION
[0031] FIG. 1 illustrates a tow-type stroller being propelled and controlled by an attendant while the attendant is jogging. It should be understood, however, that embodiments of the present invention may also be beneficially used while the attendant is merely walking. Certain embodiments may also be configured to attach to a bicycle or other vehicle, so as to permit the attendant to bring a baby, small child or toddler along for the ride. As shown in FIG. 1 , the stroller includes two wheels 1 , each with a wheel hub 2 , a carriage frame 3 , a seat assembly 4 to accommodate a child occupant, a cross bar 5 , a tow bar assembly 6 , an articulating assembly 7 , and a waist belt 8 .
[0032] FIG. 2 depicts a carriage frame 3 provided with two supporting wheels 1 spaced apart along the wheel axis 9 in a direction laterally of the direction of movement of the carriage frame 3 where each of two wheel axle 10 means is secured directly to the carriage frame 3 . Both wheel axle means 10 are coaxial to the wheel axis 9 and together bear the carriage assembly load such that all of the load supporting base of the carriage frame 3 is suspended from the axle means below the wheel axis (dropped axle) and the load base portion is positioned below a horizontal plane including the wheel axis at all times during normal use of the carriage assembly, including when the carriage is at rest and in transporting position. The purpose of this configuration is to position the load center of gravity (COG) 12 below the wheel axis 9 .
[0033] FIG. 3 shows an exploded view of the connection of the carriage frame 3 and cross-bar 5 components of the tow-type stroller of FIG. 1 . For the sake of simplicity, only one of the connections is shown in exploded view in FIG. 3 . As shown in FIGS. 2 and 3 , the axle means 10 is comprised of an axle sleeve 13 permanently affixed to the carriage frame 3 . Each axle sleeve 13 is secured to a lateral portion of the carriage frame 3 and is located along the carriage frame 3 such that the bottom most portion of the carriage frame 3 does not contact the travel surface (ground) during operation.
[0034] Each axle sleeve 13 accepts a wheel spindle 15 , which is rotatably connected to the wheel hub 2 . One or both ends of the spindle 15 may be threaded to accept a locknut 16 . The locknut 16 provides a means to prevent lateral travel of the wheel spindle 15 when the locknut abuts the wheel hub 2 . Alternatively, one end of the spindle 15 could be formed into a head to similarly prevent lateral travel of the wheel spindle 15 when the locknut abuts the wheel hub 2 . Perpendicular to the axis of the spindle, a groove 17 may be machined along the length of the spindle 15 . There are a variety of ways by which the spindle 15 may be secured within the axle sleeve 13 . In this illustration, a toggle clamp 18 is shown as a possible means to detachably connect said spindle 15 within the axle sleeve 13 . The toggle clamp 18 is connected to the carriage frame 3 such that when the toggle clamp plunger 19 is extended, it passes through a hole 20 drilled in the anterior portion of the carriage frame 3 and a hole 21 drilled perpendicular to the axis of the axle sleeve 13 . The wheel spindle 15 is accepted into the axle sleeve 13 such that the wheel spindle groove 17 lines up with the two holes 20 and 21 . When the toggle clamp plunger 19 is extended, it passes through said holes 20 and 21 and is pressed and seated within the wheel spindle groove 17 when the wheel spindle 15 is located within the axle sleeve 13 .
[0035] The lengths of the axle sleeves 13 that protrude through the interior portions of the carriage frame 3 provide a means to connect a detachable crossbar 5 . When connected, the crossbar 5 rotates freely about the wheel axis 9 .
[0036] Referring again to FIG. 1 , one end of the tow bar assembly 6 is connected to the crossbar 5 . The other end of the tow bar assembly 6 is connected to the attendant for the purpose of towing the carriage assembly. There are numerous means by which to detachably connect the tow bar assembly to the cross bar. As an example, a hole 22 may be drilled through the center portion of the crossbar 5 (the bottom of the “U”) to accept one end of the tow bar assembly 6 such that the axis of the tow bar assembly 6 is perpendicular to the wheel axis 9 whenever it is connected to the crossbar 5 . In this example, a toggle clamp assembly 23 is used to detachably connect the tow bar assembly 6 to the crossbar 5 in a manner similar to the method by which the toggle clamp 18 is utilized to detachably connect said spindle 15 within the axle sleeve 13 .
[0037] Beneficially, the carriage frame 3 , cross bar 5 , axle sleeves 13 and wheel hub 2 components are configured relative to each other such that all relative motion between said components is limited to single degree of rotational movement in the saggital plane about a single wheel axis 9 .
[0038] Excessive forward rotation of the carriage frame 3 about the wheel axis 9 could result in the front most portion of the carriage assembly striking the travel surface. Similarly, excessive rearward rotation could cause the back portion of the carriage assembly to contact the travel surface. Excessive rotation as described above may be controlled via a rotation limiter. There are numerous means by which to govern excessive rotation. One possible means to govern the rotation of the carriage assembly about the wheel axis is shown and includes an upward limiting arm 24 and a downward limiting arm 25 . The upward limiting arm 24 is rotatably connected to a post 26 . The axis of said post is oriented in the direction of travel and is connected to the carriage frame 3 . The position of the upward limiting arm 24 may be maintained onto the post 26 via a retaining clip and is oriented such that that the upward limiting arm 24 contacts the superior aspect of the crossbar 5 and resists the forward rotation of the carriage frame 3 at a rate and magnitude of force determined by the properties of a governing device such as a torsional spring 27 as shown in the illustrated embodiment. Similarly, a downward limiting arm 25 provides a means to resist the backward rotation of the carriage frame 3 .
[0039] FIG. 4A illustrates a single seat assembly 4 for a child occupant. The seat assembly may be detachably connected to the load supporting portions of the carriage frame 3 either along the interior bottom portions of the carriage frame 3 or the lateral interior portions of the carriage frame 3 . In another embodiment, a bracket 28 connected to the exterior and lateral portion of the seat assembly 4 provides a means to adjustably connect the seat assembly to the axle sleeve 13 such that the seat assembly rotates about the wheel axis 9 . In this example, the bracket provides a plurality of holes 29 each of which can accept the protruding end of the axle sleeve 13 for the purpose of adjusting the relative position of the COG 12 from the wheel axis 9 . (See FIG. 2 ).
[0040] Alternatively, and as illustrated in FIG. 4B , the function of adjusting the COG position relative to the wheel axis may be accomplished by connecting a bracket 30 to the exterior and lateral portion of the seat assembly 4 as shown. A sliding connector comprised of a sliding member 31 that can be positioned and secured along the length of the bracket 30 and a locking pin 32 , which is connected to the sliding member 31 . A coupling mechanism 33 is secured to the end portion of the axle sleeve 13 and oriented so that the portion of the coupling mechanism 33 that accepts the locking pin 32 faces the locking pin. In this example, the locking pin 32 is secured within the coupling mechanism 33 by a latching mechanism 34 when said latching mechanism 34 is in the locked position. The locking pin 32 is released from the coupling mechanism 33 when the latching mechanism 34 is in the open position.
[0041] Due to the single axis arrangement, it is desirable to minimize the saggital plane rotation of the seat assembly 4 to thus reduce excessive forward or backward tipping of the carriage assembly during operation. Maximum rotational stability of the assembly may be achieved by localizing the COG directly below the axis line 9 . As the body mass distribution of differently sized occupants (children) may result in a varying COG location of the seated occupant, it is desirable to provide a means for adjusting the COG such that it is directly beneath the axis line.
[0042] In the example, the seat assembly 4 , is comprised of a rigid bottom and a back support and provides a foot rest 35 specially modified in connection with the seat assembly 4 to provide for relative adjustment to accommodate a range of occupant lower limb lengths. The foot rest assembly is comprised of two supporting members 36 each with one end rotatably connected to an exterior portion of the seat assembly 4 and the other end constructed to accept the ends of the foot rest 35 , said footrest 35 being generally oriented horizontally with respect to the ground. During operation, the structure of the footrest 35 prevents a seated child's feet from contacting the travel surface. A flexible or a rigid barrier 37 connected between the lengths of the supporting members 36 prevents the seated child's lower limbs from contacting the travel surface.
[0043] The leading portion of the footrest 35 has a slight upward angle with respect to ground in the sagittal plane such that the bottom portion of said footrest 35 provides a rigid skid to engage the edge portion of a step, curb, or abutment (curb) to facilitate movement of the carriage assembly thereacross. As the front- and bottommost portion of the skid engages the curb, the carriage frame 3 and seat assembly 4 rotate about the wheel axis 9 permitting unobstructed forward travel of the stroller until the wheels 1 engage the edge portion of the curb. As the stroller is propelled forward, the wheels 1 surmount the curb and thus lift the entire carriage assembly over the curb without further contact between the curb and other portions of the stroller.
[0044] A headrest 38 is attached to the back support portion of the seat assembly such that the vertical position of the headrest may be adjusted relative to the seat back to accommodate a variety of seated occupant body heights.
[0045] Attached to the seat assembly 4 is a restraining apparatus wherein one or more flexible, strap-like members 39 can be engaged with the body of the child prevent, restrain, or limit movement of the child relative to the seat assembly 4 should the stroller sharply decelerate, collide with another object, or be involved in any sudden, unexpected movement or termination of movement.
[0046] Attached to the seat assembly 4 is/are one or more bar arrangements 40 extending over and around the occupant compartment, such bars or bar arrangement 40 designed to protect the occupant should the vehicle overturn.
[0047] Attached to the seat assembly 4 and/or the bar arrangements 40 is a flexible film, cloth, mesh, or solid material barrier 41 that prevents the child from accidentally placing any part of the child's body near moving parts of the carriage assembly.
[0048] FIG. 5 illustrates an alternative embodiment of the carriage assembly and is heretofore referred to as the cage frame assembly 42 . The cage frame assembly 42 is comprised of a bar arrangement to protect the occupant and includes a structural means to connect the supporting wheels 1 and the seat assembly 4 . In this example, the wheels 1 are rotatably connected to the cage frame assembly 42 via a horizontal bar member 43 . The illustration shows how the crossbar 5 is connected directly to the wheel axle and the tow bar assembly 6 is connected to the crossbar.
[0049] FIG. 6A shows the cage frame assembly 42 is comprised of one or more light-weight tubes fashioned to provide a rigid support for two wheels 1 spaced apart along the wheel axis 9 in a direction laterally of the direction of movement of the cage frame assembly 42 such that the COG 12 is maintained below the wheel axis 9 (See FIG. 2 ) at all times during normal use, including when the carriage assembly is at rest and in the transporting position as previously described.
[0050] As an example of utilization of the cage frame assembly 42 as a means of supporting the wheels 1 , the illustration shows that the threaded end of the wheel spindle 15 protrudes through the exterior portion of the wheel hub and through the end portion of the crossbar 5 (only half of the crossbar is shown to simplify the drawing) and connected to a locknut 16 . The other end of the spindle 15 supports part A 65 A of a latch mechanism so that the cage frame may be quickly engaged/disengaged from the crossbar and wheel assembly. FIG. 6B shows the detail of the latch mechanism. As shown in FIG. 6B , part B 65 B of the latch mechanism is comprised of a structural member 72 fashioned such that it provides support for: a striker 67 ; a means to slide along the horizontal bar member 43 (in this illustration by way of holes 71 on the lateral portions of the structural member 72 ); a type of plunger 66 such that when the striker is engaged in the receiving notch 74 of part A 65 A of the latch mechanism, both arms 73 of the structural member 72 engage around the lateral portion 69 of part A 65 A of the latch mechanism to prevent lateral movement of part B 65 B relative to part A 65 A of the latching mechanism. Part A 65 A of the latching mechanism is comprised of a structural member 69 which is fashioned such that it provides a means to connect to the wheel spindle through the hole 75 shown. Part B 65 B of the latch mechanism is connected to the horizontal bar member 43 via the holes 71 such that part B 65 B of the latch mechanism can slide back and forth along the length of the horizontal bar member 43 in the direction of travel. Furthermore, the position of part B 65 B of the latch mechanism along the length of the horizontal bar member 43 may be fixed via a plunger 66 that secures part B 65 B to the horizontal bar member 43 via a plurality of holes 44 along the top of the horizontal bar member 43 . The purpose of this sliding and locking function of part B along the horizontal bar member 43 is to provide a means to adjust the distance of the COG relative to the wheel axis 9 . Ideally, the attendant can perform this adjustment with minimal effort. However, the position of the final adjustment must remain secured without the possibility of a change in the adjustment position during operation of the stroller. The materials used for the members of this assembly must provide a rigid structure for maintaining a fixed relative position between the wheels 1 .
[0051] This alternative cage frame assembly 42 provides a means of incorporating a footrest 46 comprised of a rigid structure with two ends each bent at a certain angle to generally form a “U” shape along a certain plane. The ends of said foot rest are further bent away from the plane at a certain angle (theta) that the front end of the footrest 46 structure forms and upwardly angled rigid skid to engage the edge portion of a step, curb, or abutment that may be encountered during operation similar in function to the footrest 35 previously described.
[0052] The height, relative to the ground, of each of sliding means 47 attached to the lower front portion of the carriage frame 42 may be raised or lowered. Each sliding means 47 can accept one end of a rigid tube member 48 of a certain length. Each of two rigid tube members 48 is oriented generally in the direction of travel and at a certain angle relative to the ground. The ends of the footrest member 46 can accept an end of the rigid tube member 48 such that the distance between the footrest 46 and the cage frame 42 may be adjusted and secured into place by the user and to provide a means to adjust for different limb lengths of a child occupant.
[0053] FIG. 7 shows an example of a resilient tow bar assembly 6 which is comprised primarily of two elongated tubes: the first tube 49 and the second tube 50 are arranged to slide longitudinally with respect to each other either coaxially (telescopically) or collocated as shown in the illustration and parallel to the direction of travel. In this example, the means by which both tubes 49 and 50 are connected to each other permits a free, sliding movement between the tubes with the first tube 49 detachably connected to the cross bar 5 and the second tube 50 is detachably connected to the articulating assembly 7 . The length of the portion of the second tube 49 that is accepted into the drilled hole 22 in the crossbar 5 is limited by the location of a limiting collar 51 along the length of the first tube 49 .
[0054] In the example shown, brackets 52 A and 52 B span across both of the tubes 49 and 50 such that one portion of each bracket is directly affixed to the first tube 49 and the other portion of each bracket is fixed to a linear bearing 53 A and 53 B. Each linear bearing is coaxially connected to the second tube 50 . When the first tube 49 is connected to the cross bar 5 , the resulting assembly arrangement constrains movement of the second tube 50 to slide only back and forth in the direction of travel towards and away from the cross bar 5 . A simplified resilient means by which to mediate the anterior/posterior impulses generated between the carriage and the attendant during operation is illustrated by coupling the pair of tubes with a pair of elastic members 54 A and 54 B. The elastic members are arranged such that they restrict the relative linear motion between both of the tubes 49 and 50 . A simplified example of a connecting means by which to couple the elastic members to the tow bar assembly 6 is shown. In this example a connecting means 55 A is attached to one end of the second tube 50 . One end of elastic member 54 A is attached to connecting means 55 A. The other end of the elastic member 54 A is attached to connecting means 55 B. Connecting means 55 B is connected to bracket 52 A. When the first tube 49 is connected to the cross bar 5 , the resilient assembly described above resists the overall compression of the tow bar assembly 6 and moderates the rate of displacement of the second tube 50 towards the cross bar 5 and thus, the carriage assembly. Similarly, the overall extension of the tow bar assembly 6 is moderated via a resilient assembly where a connecting means 55 C is connected to bracket 52 B. One end of the elastic member 54 B is attached to connecting means 55 C. The other end of elastic member 54 B is attached to connecting means 55 D. Connecting means 55 D is connected to the other end of the second tube 50 .
[0055] Preferably, both elastic members 54 A and 54 B are attached to the respective pair of connecting means such that the elastic members are placed in a particular amount of tension when there is no axial load on the tow bar assembly. Preferably, the connecting means 55 A, and 55 D may be repositioned along the second tube 50 to increase or decrease the tension placed on each of the elastic members 54 A and 54 B. Alternatively, the overall resistance to extension and compression of the tow bar assembly 6 can be modified via selection of elastic members possessing either an increased or a decreased modulus of elasticity.
[0056] The resilient tow bar assembly 6 serves two primary functions: 1) to connect the carriage assembly and attendant so that the attendant may propel and control the carriage assembly velocity and direction, and 2) to attenuate the forward and backward impulses along the tow bar assembly 6 resulting from the accelerations and decelerations associated with walking or running as the attendant propels the carriage assembly. The resilient tow bar assembly 6 includes two rigid, elongated members which may be arranged either concentrically or in parallel and are connected to each other by means of either bushings or bearings such that the free movement between the two members is restricted to a linear motion along the axis of said members if arranged concentrically or along parallel axes if arranged in parallel. One end of the first elongated member is connected to the cross bar and the other end of said member is connected to the second elongated member. One end of the second elongated member is connected to the first elongated member and the other end of the second elongated member is connected to the attendant via an articulated assembly and a belt assembly.
[0057] The overall length of the tow bar assembly 6 varies with the position of the two elongated members 49 and 50 relative to each other. When connected to the attendant and to the carriage assembly, the overall length of the tow bar assembly extends or compresses in proportion to the distance between the carriage assembly and the attendant as the attendant either accelerates away from the carriage assembly when propelling it in the forward direction (extension) or when the attendant decelerates and the carriage continues to travel in the direction of the attendant due to the carriage's momentum (compression). Thus, the state of the tow bar assembly may be defined as being in extension or compression depending on the instantaneous overall length of the tow bar assembly. A third state, the length of the tow bar assembly at which the transition between extension and compression occurs may be defined as “neutral.”
[0058] The forward and backward impulses transmitted through the tow bar assembly 6 and experienced by the attendant and the carriage assembly as the attendant propels the stroller may be attenuated by controlling the rates at which the tow bar assembly 6 extends and compresses. This may be achieved by connecting one or more elastic or damping members to the components of the tow bar assembly 6 in an arrangement that permits said elastic or damping members to moderate the extension or compression motions of the tow bar assembly 6 and thus, the rate at which the tow bar assembly 6 extends or compresses.
[0059] The forward end of the tow bar assembly 6 is detachably connected to an articulating assembly 7 . In this example, a toggle clamp assembly 56 is shown as a possible means to quickly connect and disconnect one end of the second tube 50 to a connector tube 57 . The articulating assembly 7 provides four degrees of freedom of movement at the point of connection between the tow bar assembly 6 and the attendant (vertical translation and rotation in the saggital plane, lateral translation and rotation in the transverse plane) relative to the carriage assembly during operation. The articulating assembly 7 comprises a belt 58 of material sufficient in strength to support the towing loads during operation having at least two holes 59 to accept standoffs 60 ; a single, horizontally oriented tube 61 parallel to the ground supported by said standoffs 60 ; a slider tube 62 fitting over said horizontally oriented tube 61 with an inner diameter greater than the outer diameter of the horizontally oriented tube 61 to permit said slider tube 62 to travel laterally and to follow the path of the horizontally oriented tube 61 ; a swivel pin 63 connected to the slider tube such that the axis of rotation created by the swivel pin is normal to the ground; and a connector tube 57 of which one end is connected to said slider tube 62 by means of the swivel pin 63 and the other end connects telescopically within the second tow bar assembly tube 50 providing a means to selectively vary the running distance between the attendant and the carriage assembly. The function of the swivel pin 63 serves to facilitate turning of the carriage assembly by the attendant during operation by permitting rotation of the attendant's body in the transverse plane when changing the direction of travel.
[0060] FIG. 7 shows that the articulating assembly 7 is secured to the rear portion of a waist belt 58 which is, in turn, used to connect to the attendant's waist or hips. A harness or vest may also be used in place of the waist belt provided that said harness or belt adequately distribute the anterior/posterior forces involved in propelling the carriage assembly across the attendant's torso. The belt or vest may be comprised of any variety of materials but preferably of those materials that provide the strength necessary to withstand said anterior/posterior forces involved in operation while permitting ventilation means to transfer heat away from the interior of the belt nearest the attendant's body to the incident environment. Further, the belt should provide for facile circumferential adjustment around the attendant's waist or hips to minimize movement between the articulating assembly 7 and the attendant's torso.
[0061] The tightness of the waist belt 58 around the attendant's waist provides sufficient friction around the attendant's waist to support the vertical and horizontal loads generated, in all three planes, during operation of the loaded carriage assembly.
[0062] As previously described, one of the functions of the resilient tow bar assembly is to attenuate the forward and backward impulses along the tow bar assembly resulting from the accelerations and decelerations associated with walking or running as the attendant propels the carriage assembly. Attenuation of said impulses may be accomplished by various means. The exemplary tow bar assembly shown in FIG. 7 utilizes elastic members 54 A and 54 B that are connected to the components of the tow bar assembly in an arrangement such that one or more of the elastic members are maintained in a state of tension irrespective of the amount of tow bar extension or compression. The graph in FIG. 8 a illustrates the relationship between the resistive forces exerted by said elastic members as a function of the tow bar compression/extension. In the graph, the horizontal axis represents the measure of the tow bar assembly extension (increasing to the right) and compression (increasing to the left), the point of origin where the axes intersect represents the transition point between tow bar assembly extension/compression (neutral position), and the vertical axis represents the amount of resistance to the compression or extension movement exerted by the elastic members on to the tow bar assembly. It is important to note that in this arrangement, there exists a single transition point between extension and compression states.
[0063] The relationship between tow bar compression/extension and resistive force may be modified from the example above through an alternate configuration wherein the elastic members may be connected to the components of the tow bar assembly in an arrangement such that the state of transition between compression/extension is expanded and bounded by a certain interval along the horizontal axis as shown in FIG. 8 b . This represents a different function than the previous example where the transition between compression and extension states were limited to a single point along the horizontal axis as shown in the graph in FIG. 8 a . Expanding the length of the neutral state creates a “neutral zone” along the horizontal axis. The graph in FIG. 8 b shows a neutral zone defined by an interval length along the horizontal axis in which the resistance to the extension or compression of the tow bar assembly is reduced or negligible. This configuration serves to reduce or to uncouple anterior and posterior forces between carriage and attendant whenever the tow bar assembly length is within the neutral zone, thus reducing or eliminating impulses that occur when the tow bar assembly transitions between states of compression and extension. There are several arrangements by which elastic members may be connected to the tow bar assembly components to accomplish the function of creating a “neutral zone” as described above.
[0064] FIG. 9 illustrates an example of such an arrangement where a first elongated member 80 of the tow bar assembly with one end connected to the cross bar 5 and the other end detachably connected to a second elongated member 81 of the tow bar assembly by means of a linear bearing assembly 82 . Said bearing assembly is permanently connected to one end of the second elongated member 81 . Said second elongated member 81 is connected to the attendant via articulated assembly 7 and belt 58 . The first elongated member 80 is permitted to slide axially within the linear bearing assembly 82 such that no lateral movement between the first and second elongated members is permitted. Furthermore, along a certain portion of body of the first elongated member 80 which corresponds approximately to the neutral position as previously defined, is a connecting means for connecting to one end of an elastic member such as a spring, latex tubing, resistance band, bungee cord, etc. shown as connection A which may be comprised of an eye hook traversing the body of the first elongated member 80 such that the elongated member is permitted to freely slide within the linear bearing assembly 82 .
[0065] A cross bracket 83 is permanently connected to the linear bearing assembly 82 such that the elongated portions of the cross bracket extend away from the linear bearing assembly in a direction which is perpendicular to the general axis of the tow bar assembly. The purpose of the cross bracket is to provide a rigid structure upon which to support connection points for the elastic members 84 and 85 as shown in the illustration. In this example, the cross bracket 83 is comprised of a rigid, elongated member of a certain length that is fixedly connected to the linear bearing 82 , said linear bearing 82 is connected to the second elongated member 81 of the tow bar assembly. The cross bracket 83 is oriented such that the elongated portion of the bracket is perpendicular to the axis of the tow bar assembly and the ends of the bracket are equidistant from the axis of the tow bar assembly.
[0066] A means for connecting elastic members 84 and 85 to the tow bar assembly components are located at each end of the elongated portion of the cross bracket shown as connection B and C, respectively. The means for connecting to the elastic members 84 and 85 to the cross bracket 83 may include, but are not limited to, an eye hook as previously described.
[0067] The schematics in FIG. 10 illustrate the tow bar assembly function when the elastic members connected to the tow bar assembly components are arranged to permit an extended “neutral zone” whereby said elastic components provide little or no resistance to the extension and compression motion of the tow bar assembly. FIG. 10 a shows that each elastic member 84 and 85 increasingly resists the extension of the tow bar assembly as the first elongated member 80 is translated from the neutral zone towards the direction of increased extension relative to the position of the second elongated member 81 . Similarly, but in the opposite sense, the compression of the tow bar assembly is resisted by the same elastic members 84 and 85 as the first elongated member 80 proceeds from the neutral zone towards the direction of increased compression (relative to second elongated member 81 ) as shown in FIG. 10 b . FIG. 10 c shows the state of the tow bar assembly is neutral when connection point A on the first elongated member 80 is in line with connection points B and C on the cross bracket 83 . This position is defined as the neutral point. When the tow bar assembly length is at the neutral point, the elastic members exert no resistance to the movement between the components of the tow bar assembly. This is because each elastic member can provide resistance only in the direction axial to the elastic member. This holds true even when the elastic members are connected to their respective connection points under tension. While the position of connection A is within the “neutral zone”, the elastic members impart minimal resistance because the magnitude of the axial resistive force component as compared to magnitude of the perpendicular resistive force component is relatively small. However, as connection point A travels beyond the “neutral zone” in either direction, the elastic members exert an increasingly significant resistance to the extension and compression movements of the tow bar assembly. This is because the magnitude of the axial resistive force component becomes increasingly comparable to the magnitude of the perpendicular resistive force component.
[0068] An alternate design by which to create a “neutral zone” for the tow bar assembly utilizes, in place of axial elastic members, a resistive component such as a leaf spring to control the rate of extension and compression of the tow bar assembly. Unlike the axial resistance provided by the elastic members described above, a leaf spring provides resistance in a direction which is perpendicular to the elongated axis of said leaf spring.
[0069] FIG. 11 a illustrates an example of an alternative arrangement for creating a “neutral zone” as described above; a cantilever type spring connected to the tow bar assembly components in an arrangement to provide resistance to the extension and compression movements of the tow bar assembly. Unlike the elastic members previously described which provide axial resistance, the cantilever type spring provides resistance to lateral deflection of said cantilever spring. A crossbow is an example of a cantilever spring.
[0070] As shown in FIG. 11 a , this arrangement includes a cantilever spring 87 connected to the tow bar assembly to provide increasing resistance to the extension and compression movement of the tow bar assembly as the state of the tow bar assembly moves increasingly away from the “neutral zone”. The figure shows a first elongated member 80 of the tow bar assembly with one end connected to the cross bar 5 and the other end detachably connected to a second elongated member 81 of the tow bar assembly by means of a linear bearing assembly 82 . Said bearing assembly is rigidly connected to one end of the second elongated member 81 . The other end of the second elongated member is connected to the attendant via articulated assembly 7 and belt 58 . The first elongated member 80 is permitted to slide axially within the linear bearing assembly 82 such that no lateral movement between the first and second elongated members is permitted. Furthermore, along a certain portion of body of the first elongated member which corresponds approximately to the neutral position, as previously described, a means is provided for connecting to the first elongated member 80 a flexible material with high tensile strength, such as a wire. Said means, connection A, may be comprised of an eye hook, wire rope sling, or other wire rope assembly for the purpose of connecting to the first elongated member 80 either the ends of two separate wire lengths or the midpoint of a single length of wire. Alternatively, connection A may be comprised of a pin oriented perpendicular to the ground to provide a means of connecting to the first elongated member 80 a pair of rigid elongated members such as two metal rods so that the motion of each of the rods is limited to rotation in the transverse plane about connection A. For purposes of this discussion, either the wire or the pair of metal rods, previously described, which are attached to connection A are referred as the Cantilever Spring Hitch 86 . In either of the configurations, connection A must be of sufficient strength to withstand the forces involved in propelling the carriage and occupant under a variety of loading situations and must be connected to the first elongated member 80 such that the first elongated member 80 may freely slide in either direction within the linear bearing 82 .
[0071] FIG. 11 a shows the middle portion of a cantilever spring 87 rigidly connected to the linear bearing 82 such that the elongated portions of the cantilever spring 87 extend away from the linear bearing assembly 82 in a direction which is perpendicular to the general axis of the tow bar assembly. FIG. 11 b shows the ends of the cantilever spring 87 when deflected in either the compression or extension direction along the transverse plane. At each end of the cantilever spring 87 connections B and C provide a means for connecting to the Cantilever Spring Hitch 86 . Connections B and C are comprised of an eye hook, turnbuckle, or other such means that when said means are connected to the Cantilever Spring Hitch 86 act to deflect the ends of the cantilever spring 87 in the direction of travel of connection A as connection A travels increasingly towards either the elongation or compression state. In this arrangement, a cantilever spring type is connected to the components of the tow bar assembly to provide a “neutral zone” in which said cantilever spring offers negligible resistance to the extension and compression of the tow bar assembly while connection A is within said zone, however, said cantilever spring exerts increasing resistance to the tow bar assembly extension or compression as connection A travels further towards either of said states.
[0072] FIG. 12 shows the crossbar 5 described in FIG. 3 is comprised of a “U” shaped member with each arm connected to the interior aspect 11 of each hub. As an example of an alternative arrangement of the carriage components described above, an axle sleeve is shown in this illustration that would accept the spindle 15 as a means of rotatably connecting to the axle sleeve 66 the wheel hubs 2 . Said axle sleeve is comprised of a two tubes perpendicular to each other where the axle tube 66 a is perpendicular to the direction of travel and the connecting tube 66 b is parallel to the direction of travel. In this example, the threaded portion of the spindle 15 is accepted by the axle tube 66 a and secured on each side of the axle tube 66 a by two nuts 70 . The hub 2 accepts the non threaded portion of the spindle and is rotatably secured to the axle tube such that the exterior aspect 14 of the hub is adjacent to the axle tube 66 b . Each end of the crossbar 65 shown in this illustration accepts the connecting tube 66 b , as the diameter of the crossbar tube 65 is greater than that of the connecting tube 66 b.
[0073] A slot or groove is machined into the side of the connecting tube 66 b to accept a sliding pin 68 which is secured to the side of the crossbar 65 as shown. The slot is comprised of three sections. Section 67 a allows the sliding pin to travel axially along connecting tube 66 b . Section 67 b allows the sliding pin to travel transversely to connecting tube 66 b . When the connecting tube 66 b is accepted by the end of the crossbar 65 , the sliding pin travels along the slot or groove just described to permit the wheel axle to be inserted, rotated, and locked into position. A collar clamp 69 may be used to clinch the outer tube of the crossbar 65 to the connecting tube 66 b and thus securing the axle sleeve, spindle and wheel hub to the crossbar such that the arms of the crossbar are connected to the exterior portion 14 of the wheel hubs.
[0074] The purpose of this design alteration would be to substitute the structural support function of the carriage frame member 3 shown in FIG. 3 with the crossbar 5 shown in FIG. 8 , providing that the cross bar member material is of sufficient strength and stiffness, thus eliminating the need for the carriage frame 3 . The crossbar, by connecting its arms to the exterior aspects of the hubs 14 , would serve to protect the wheels from coming in contact with obstacles that may be encountered during operation of the carriage.
[0075] While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. Furthermore, while certain advantages of the invention have been described herein, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. | A two-wheeled stroller is disclosed and claimed. The stroller is a tow-type stroller to enable a child to accompany an attendant who is engaged in walking or running activity over a variety of ground surfaces and grades at various walking and running velocities. The stroller includes a carnage assembly, a tow bar assembly, and a harness assembly. The carnage assembly includes a seat upon which the child being transported is seated and two wheels, with the center of gravity of the carriage assembly and child (if present) positioned below the wheel axis of rotation. The harness assembly is adjustably affixed to the attendant, and is connected to the carriage assembly by the tow bar assembly. | 1 |
This Application is the U.S. National Phase of International Number PCT/GB2009/051515 filed on Nov. 11, 2009, which claims priority to Great Britain Application Number 0900097.7 filed on Jan. 7, 2009, and U.S. Provisional Application No. 61/114,141 filed on Nov. 13, 2008.
The present invention relates to Hybrid Riser Towers, and in particular to reduction of the problem of vortex induced vibration on Hybrid Riser Tower structures.
Hybrid Riser Towers are known and form part of the so-called hybrid riser, having an upper portions (“jumpers”) made of flexible conduit and suitable for deep and ultra-deep water field development. U.S. Pat. No. 6,082,391 (Stolt/Doris) proposes a particular Hybrid Riser Tower (HRT) consisting of an empty central core, supporting a bundle of (usually rigid) riser pipes, some used for oil production some used for injection of water, gas and/or other fluids, some others for oil and gas export. This type of tower has been developed and deployed for example in the Girassol field off Angola. Insulating material in the form of syntactic foam blocks surrounds the central core and the pipes and separates the hot and cold fluid conduits. Further background has been published in paper “Hybrid Riser Tower: from Functional Specification to Cost per Unit Length” by J-F Saint-Marcoux and M Rochereau, DOT XIII Rio de Janeiro, 18 Oct. 2001. New versions of such risers have been proposed in WO 02/053869 A1. The contents of all these documents are incorporated herein by reference, as background to the present disclosure.
The phenomenon of Vortex-induced vibrations (VIV) is a known problem for HRTs, and indeed for offshore oil exploration and production risers in general. VIV are motions induced on bodies, such as an installed riser, facing an external flow by periodical irregularities on this flow. As a result of these periodical irregularities and the slowing of the flow around the riser, vortices are formed. These vortices change the pressure distribution along the riser surface and when not formed symmetrically around the riser cause different lift forces to develop on each side of the riser, thus leading to motion transverse to the flow. VIV is an important source of fatigue damage to risers. These elongate slender structures experience both current flow and top-end vessel motions, which give rise to the flow-structure relative motion and cause VIV. The top-end vessel motion causes the riser to oscillate and the corresponding flow profile appears unsteady.
It is known to equip individual risers with strakes, or other protrusions, to disrupt the cylindrical profile and reduce VIV. Difficulties arise, however, when addressing the problem of VIV for a bundle of risers such as required for a HRT, as current fabrication does not make allowance for the fitting of said strakes.
Consequently, it is an aim of the invention to address some or all of the above mentioned issues.
In a first aspect of the invention there is provided a riser tower structure of a type comprising a plurality of elongate objects, said riser tower structure being provided with blocks along at least part of its length, said blocks providing said riser tower with a substantially circular cross-sectional profile, wherein one or more strakes are provided on the outside of said blocks.
Said strakes may be helical in shape. More than one strake may be provided on a single block, circumferentially offset from one another.
Said blocks may comprise insulation and/or buoyancy modules. They may be formed out of a plurality of parts. In one embodiment said blocks may comprise a plurality of main sections, preferably two, which are attached together around one of said elongate elements, forming a channel therefor. Said main parts may further comprise recesses, around their periphery and along their length for the location of the remaining of said plurality of elongate objects, said blocks further comprising closing pieces to retain said elongate objects when in place.
Said blocks (when assembled together if necessary) may be provided with one or more inserts, each for the location therein of said one or more strakes. Said insert may follow the intended footprint of its corresponding strake.
Said strakes may be made of the same material than said blocks.
One of said elongate objects may comprise a central core. Said plurality of elongate objects may comprise a plurality of conduits arranged around the central core. Additionally, other elongate objects may make up the riser, such as umbilical and control lines. Said riser tower structure may comprise said blocks along the majority of the riser length. Said riser tower may comprise guide frames along its length, to guide the risers. Said blocks may be provided between successive guide frames.
In a further aspect of the invention there may be provided a method of constructing a riser tower structure comprising:
attaching blocks around a central core of a riser tower structure, said blocks being provided with recesses, around their periphery and along their length. locating conduits and/or other elongate objects in said recesses; closing said recesses with a closing piece, thus providing said riser tower structure with a substantially circular cross sectional profile along its length; and attaching at least one strake to the outside of said riser tower structure.
Said riser tower structure maybe any one of those described with the first aspect of the invention.
Said riser tower is preferably fabricated in sections, each of said sections being fabricated according to the first aspect of the invention and then assembled together. Each section may be greater than 100 meters long, and may lie between 100 meters and 300 meters in length. In a main embodiment they will be between approximately 150 and 200 meters.
Said strake may be attached to the blocks. Said method may comprise the providing of an insert for each strake during fabrication of said blocks.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which:
FIG. 1 shows a known type of hybrid riser structure in an offshore oil production system;
FIG. 2 shows a riser bundle having buoyancy blocks adapted for the addition of strakes;
FIG. 3 shows the riser bundle of FIG. 2 , with strake ready for attachment; and
FIG. 4 shows the riser bundle of FIG. 2 with two strakes attached.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring to FIG. 1 , the person skilled in the art will recognise a cut-away view of a seabed installation comprising a number of well heads, manifolds and other pipeline equipment 100 to 108 . These are located in an oil field on the seabed 110 .
Vertical riser towers are provided at 112 and 114 , for conveying production fluids to the surface, and for conveying lifting gas, injection water and treatment chemicals such as methanol from the surface to the seabed. The foot of each riser, 112 , 114 , is connected to a number of well heads/injection sites 100 to 108 by horizontal pipelines 116 etc.
Further pipelines 118 , 120 may link to other well sites at a remote part of the seabed. At the sea surface 122 , the top of each riser tower is supported by a buoy 124 , 126 . These towers are pre-fabricated at shore facilities, towed to their operating location and then installed to the seabed with anchors at the bottom and buoyancy at the top.
A floating production unit (FPU) 128 is moored by means not shown, or otherwise held in place at the surface. FPU 128 provides production facilities, storage and accommodation for the fluids from and to the wells 100 to 108 . FPU 128 is connected to the risers by flexible flow lines 132 etc arranged in a catenary configuration, for the transfer of fluids between the FPU and the seabed, via riser towers 112 and 114 .
Individual pipelines may be required not only for hydrocarbons produced from the seabed wells, but also for various auxiliary fluids, which assist in the production and/or maintenance of the seabed installation. For the sake of convenience, a number of pipelines carrying either the same or a number of different types of fluid are grouped in “bundles”, and the riser towers 112 , and 114 in this embodiment comprise each one a bundle of conduits for production fluids, lifting gas, water and gas injection, oil and gas export, and treatment chemicals, e.g. methanol. All the component conduits of each bundle are arranged around a central core, and are held in place relative to each other (in the two lateral dimensions, longitudinal movement not being prevented) by guide frames attached to the central core.
FIG. 2 shows a part of a riser bundle having buoyancy blocks adapted for the addition of strakes to counteract the issue of vortex induced vibration (VIV). Shown is a central core 200 , which may or may not double as a fluid conduit with riser conduits (or umbilicals etc.) 210 arranged therearound. Buoyancy blocks, formed in two halves 230 a , 230 b are assembled (possibly bolted together) around the core pipe 200 , said blocks forming a channel 220 for said core 210 . Said blocks may be specifically designed to be within the outside diameter of the riser tower.
Recesses are formed in the periphery of the buoyancy blocks 230 a , 230 b , each for the locating therein of the individual riser conduits 210 (in this example; in other embodiments, recesses may be shared by more than one conduit or umbilical etc.). Closing gates 240 are provided to form closed channels for each riser conduit 210 , while providing the structure with a largely unbroken cylindrical cross section (these may be bolted, or bonded in place with adhesive, or both). These gates 240 may be made from the same material as the buoyancy blocks 230 a , 230 b . Both the central core 200 and risers 210 are loose inside their channels, with the buoyancy force imparted onto the central core via guide frames (not shown) located at various points along the riser bundle.
A strake insert 250 is provided onto each of said riser buoyancy blocks 230 during their fabrication. A template may have been used to ensure perfect match with the strake to be inserted therein. The two buoyancy block halves 230 a , 230 b should be correctly paired together during installation, which ensures continuity of the strake insert 250 .
FIG. 3 shows the assembled riser bundle of FIG. 2 with strake 300 shown, ready to be attached. In an embodiment, the strake is made from the same material as the buoyancy blocks 230 a , 230 b , and is specifically matched to a particular pair of buoyancy blocks 230 a , 230 b . Said strake should be substantially continuous and allow no, or minimal water passage between it and the buoyancy block.
FIG. 4 shows the assembled riser bundle with two strakes 300 attached, circumferentially offset from one another, one of said strakes in place in said insert 250 . Of course, the other strake 300 will have its own corresponding insert 250 . The strakes may be bolted in place, and/or bonded with adhesive. The inserts 250 may therefore be provided with threads to receive the bolts.
There are a number of advantages of this arrangement over the fabrication of steel strakes attached onto the guiding frames. These would be both heavier and less efficient, as there would be a gap between the strake and buoyancy block. Furthermore, the above embodiment allows for efficient fabrication and assembly. Essentially the foam blocks (with inserts for the strakes), closing gates and strakes can be fabricated at the same time from the same material. Each set of the above should be identified to go together and not be mixed.
Consequently the installation of the strakes can become a standard procedure, to take place once the buoyancy blocks and closing gates have been assembled to the riser bundle.
The above embodiments are for illustration only and other embodiments and variations are possible and envisaged without departing from the spirit and scope of the invention. For example, the riser arrangements depicted are simply for illustration and may be varied, and in particular the number of strakes may be varied. Strakes do not necessarily have to be helical in shape. | Disclosed is a riser tower structure including a plurality of elongate objects. The riser tower structure is provided with blocks, preferably of buoyant material, along at least part of its length. The blocks provide the riser tower with a substantially circular cross-sectional profile, wherein one or more strakes are provided on the outside of the blocks. The strakes in a main embodiment are helical. Also disclosed is a corresponding method of constructing such a riser tower structure. | 4 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of the German patent application No. 102015122308.2 filed on Dec. 18, 2015, the entire disclosures of which are incorporated herein by way of reference.
BACKGROUND OF THE INVENTION
The invention relates to a process for the recycling of material comprising unhardened prepreg wastes to produce fiber-containing press compounds (BMC).
Prepregs are fiber products in sheet form or in strand form which comprise glass fibers or carbon fibers and which have been treated with reactive resin. Resin used can be epoxy resin. The epoxy resins used are formulated in such a way that they harden at a particular temperature. Epoxy resins used in aircraft construction mostly harden at 180° C.; curing temperatures of the epoxy resins used in other technical sectors are usually different, mostly being significantly lower. Because the reactive resin of the prepregs has limited shelf life, it can be necessary to cool prepregs during storage. After a particular period of exposure of these prepregs to higher temperatures (for example room temperature) they are subject to usage limitations, because the resin has already reacted to an unacceptable extent, and cures. It is naturally desirable that this material that has exceeded its shelf life is recycled. Carbon prepregs in particular are, moreover, very expensive.
Lay-up procedures, for example AFP processes or ATL processes (automated fiber placement, automated tape laying) moreover produce offcut material. On the prepreg rolls there can, moreover, be prepreg residues that cannot be used for lay-up (roll ends). The final cutting-to-size of a workpiece prior to hardening can also produce single- or multilayer wastes.
Fiber-containing press compounds are composed of short glass fibers or short carbon fibers and a matrix resin, and are known as bulk molding compounds (BMC). BMC can be processed in the hot-press process. For this, the BMC is inserted centrally into a heated, divided mold. Closure leads to distribution of the BMC within the mold cavity. BMC can also be processed by injection molding.
BMC can be composed of a mixture of from 10 to 35% of resin, from 10 to 50% of fibers and from 0 to 70% of fillers and/or additives.
Production of BMC from prepreg wastes can begin with removal of the resin, for example by pyrolysis. The resin-free fibers can then be comminuted and mixed with fresh resin, fillers and additives.
DE 19514543 C1 discloses a process for the reclamation and recycling of offcut material wastes from webs made of resin that is still reactive, where the offcut material wastes are chopped in a particular way, the viscosity of the resin is reduced by heating or addition of solvent, and mechanical shear stress is used to produce a mixture of separated fibers and resin which is then used as raw material for further processing.
SUMMARY OF THE INVENTION
It is an object of the present invention to recycle offcut wastes of prepreg material made of unhardened prepregs without first removing the resin. The person skilled in the art could not have anticipated what has now been found: that the disadvantages of the prior art are eliminated by a process for the recycling of wastes from webs or strands made of carbon fibers and/or glass fibers (prepreg wastes) respectively comprising reactive resin A, characterized by the following steps:
a) homogenization of webs or strands made of carbon fibers and/or glass fibers (prepreg wastes) respectively comprising reactive resin A, where the prepreg wastes are comminuted,
b) dispersion of fillers and/or additives in reactive resin B,
c) mixing of resin B, homogenized carbon fibers and/or glass fibers respectively comprising reactive resin A, and optionally of fillers and/or additives, where the reactive resins A and B are mutually compatible or identical,
d) further processing of the mixture of resin, fillers and/or additives and prepreg wastes to produce molded workpieces. Prepreg wastes can thus be recycled to produce fiber-containing press compounds without any requirement for prior separation of the fibers from the resin. The process of the invention permits easy handling of the tacky prepreg wastes, processing of large quantities of the waste materials, and indeed in specific cases continuous recycling, and finally the re-use of these wastes as raw material.
For clarification, it should be noted that it is difficult to draw a clear distinction between the terms “fillers” and “additives.” For the purposes of the invention, therefore, the term “fillers and/or additives” is used with the intention of encompassing all such additions without differentiating between fillers and additives. The fillers and/or additives can in particular be incorporated successfully into the resin B by using a disperser disc, and it is also advantageous here that the resultant mixture exhibits homogeneous dispersion of the fillers and/or additives, can be produced without agglomerates, and is heated to 70° C. via introduction of mechanical energy, with resultant improved flow properties. A particularly elegant homogenization method of the process of the invention uses an enclosed space in which conveying action and shear action, for example provided by a screw, allow both comminution and mixing of the prepreg wastes. The ratio by weight of resin B to prepreg wastes is preferably from 2:1 to 1:5, particularly preferably from 1:1 to 1:2. The ratio by weight of the entirety of fillers and/or additives to prepreg wastes is preferably from 2:1 to 1:5, particularly preferably from 1:1 to 1:2. Formulations that have proved successful comprise, in each case based on the compound, from 1/3 to 1/2 of prepreg wastes, from 1/3 to 1/4 of resin B and from 1/3 to 1/4 of the fillers and/or additives. It is moreover preferable that the homogenization of the prepreg wastes is achieved with a guillotine, screw-type extruder, twin-screw extruder, injection-molding machine, dicer, portal-controlled ultrasound cutter, rotary cutter or rolling crusher. In the case of unidirectional fibers, the guillotine here is oriented in such a way that its blade is in essence perpendicular to the fiber direction. In the case of multiaxial laid scrims, there can be a rotary cutter orthogonal to the guillotine, in order that fibers oriented in essence parallel to the guillotine blade are likewise comminuted. The guillotine can be of the type seen at (http://www.pierret.com/de/produits/coupeuses/) (a copy of which is filed herewith). If a screw-type extruder, twin-screw extruder or injection-molding machine is used, the following operating parameters must be selected and balanced with respect to one another in such a way that the shear forces arising in the composition made of resin A and fibers comminute the fibers to the desired dimensions: screw geometry, rotation rate and conveying length. When a dicer is used, the dimensions of the comminuted fibers can be determined very easily via the dimensions of the grid. A portal-controlled ultrasound cutter is usually part of an AFP system. In the AFP procedure the laid-up fibers are thus cut to the desired length dimension. The unwanted parts of the fibers beyond the desired length can likewise be chopped in a manner that makes them directly suitable for use in a process of the invention. This type of cutter can also be operated independently of an AFP system. Rotary cutters can be used in machinery, or else manually. Rolling crushers can be successful in comminuting the prepreg wastes when the wastes are brittle. Brittleness can generally be increased, and the comminution procedure can thus be facilitated, by using cooled prepreg wastes, for example by adding a coolant that evaporates to leave no residue (liquid nitrogen, dry ice) to the homogenization apparatus. This is not possible when extruders and injection-molding machines are used. Another possibility is prior cooling of the prepreg wastes to temperatures below −18° C. The fiber length is advantageously selected in such a way that the flow properties of the resultant product are appropriate for the component to be produced: longer fibers provide greater stability to a component; shorter fibers permit better flow of the press compound and thus production of geometries with greater complexity. It is preferable to comminute the prepreg wastes in such a way that the fiber length is at most 50 mm, preferably from 6 to 30 mm, particularly preferably from 10 to 24 mm; 95% of the fibers by mass here are intended to be within the stated range. When a screw-type extruder, twin-screw extruder or injection-molding machine is used, the scattering range can be controlled via the following operating parameters: screw geometry, rotation rate and conveying length. It is preferable that the fillers and/or additives comprise CaCO3, preferably marble, talc powder, aluminum hydroxide or magnesium hydroxide, MgO, silica gel, pigments and/or silica. Aluminum hydroxide is also termed aluminum trihydrate, and has flame-retardant effect. Very particular preference is given to talc powder and aluminum trihydrate. It is moreover particularly preferable that a portion of the fillers and/or additives is added in step a). This reduces the tackiness of the prepreg wastes that have been homogenized and are to be homogenized. It is preferable that 10% of all of the fillers and/or additives to be added are added in step a). It is moreover particularly preferable that the steps a) to d) are carried out in their alphabetic sequence. It is moreover particularly preferable that the chronological separation between step c) and d) is at most 2 months. The shelf life of the reBMC product of the invention at −18° C. is up to 2 months. It is moreover particularly preferable that step c) takes place at a temperature of at most 80° C., preferably at most 60° C. This avoids any significant hardening of the resin, because that requires at least 160° C. and is usually achieved at 180° C. If the process of the invention is intended for prepreg wastes which cure at lower temperatures, a temperature sufficiently different from this temperature must be maintained during the steps a), b) and c) which involve thermal stress. It is moreover particularly preferable that step c) is carried out in a screw-type kneader, sigma kneader, wing kneader or high-speed mixer. The mixing procedure is usually carried out batchwise for from 5 to 15 minutes, preferably from 10 to 15 minutes. There are known continuous compounding processes for the production of BMC, and these can likewise be used for the purposes of the process of the invention. It is moreover particularly preferable that step e) takes place in the hot-press process or injection-molding process.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE shows a process flow diagram of the method of the invention with process variants.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The prepreg waste ( 1 ) collected must comprise as yet unhardened matrix resin. Materials that can be used are prepreg strips, mats, sections, and residues, which may be unidirectional or woven fabrics, single-ply or multiple-ply. Other requirements are fillers and/or additives ( 2 ) and resin B ( 3 ).
The prepreg waste is subjected to a homogenization step: homogenization is achieved either by cutting ( 4 ) or by shearing ( 5 ). In the case of homogenization by cutting ( 4 ), the prepreg waste is comminuted to produce strips or small fragments. A guillotine or a dicer can be used to achieve this. Another possible pretreatment method is homogenization by shearing ( 5 ). In the case of homogenization by shearing ( 5 ) the prepreg waste is, by way of example, extruded in a screw-type extruder or twin-screw extruder. The temperature here is set in such a way that no hardening of the matrix resin occurs. The resultant homogenized prepreg waste ( 7 ) can comprise short fibers of length from 5 to 20 mm, randomly orientated.
Resin B ( 3 ) and fillers and/or additives ( 2 ) can be introduced into the process in various ways. One possible method introduces resin B ( 3 ) and fillers and/or additives ( 2 ) into a mixing apparatus (d), (f) and disperses ( 6 ) the fillers and/or additives ( 2 ) in the resin B ( 3 ). A disperser disc or a dissolver can be used to achieve this. This produces the dispersion of resin B with fillers and/or additives ( 8 ). A second possible method introduces resin B ( 3 ) and fillers and/or additives ( 2 ) into a mixing apparatus (c), (e) into which the homogenized prepreg waste ( 7 ) is also introduced. In variants of both processes, a portion of the fillers and/or additives ( 2 ) is introduced into the apparatus (a) in which homogenization is achieved by cutting ( 4 ), or a portion of the fillers and/or additives ( 2 ) is introduced into the apparatus (b) in which homogenization is achieved by shearing ( 5 ).
Resin ( 3 ), fillers and/or additives ( 2 ), and also the homogenized prepreg waste ( 4 ) are fed into a mixing apparatus ( 9 ). As described, it is possible either to feed all three components directly or to add a dispersion ( 8 ) of fillers and/or additives ( 2 ) in resin ( 3 ). A particularly suitable mixing apparatus ( 9 ) is a twin-screw kneader. The nature of the resin must be such that it is compatible with the matrix of the prepreg waste. In particular, it is amenable to homogeneous mixing therewith and to successful hardening. Hexply M21E epoxy-resin-containing carbon prepregs from the company Hexcel, as used in aircraft construction, are by way of example compatible with the resins RTM6, M21 and DLS1791 which are likewise marketed by the company Hexcel. Additional resin is required to fill cavities in the randomly oriented fibers; these additional cavities can be attributable to the fact that the randomly oriented fibers comprise more cavities or require more space, and therefore absorb more resin than unidirectionally orientated fibers.
Particular fillers and/or additives ( 2 ) that can be used are flow improvers, for example CaCO3 (chalk or marble), preferably with particle size from 5 to 50 micrometers, and/or magnesium hydroxide or aluminum hydroxide, silica or silica gel; it is moreover possible to use release agents, pigments, stabilizers, catalysts and/or inhibitors.
Quantities that can be used, based on the final BMC products, are from 40 to 70% by weight of prepreg wastes, from 10 to 50% by weight of resin, from 10 to 30% by weight of flow improvers, up to 5% by weight of release agents, up to 10% by weight of pigments and/or up to 10% by weight of catalysts and/or inhibitors.
It can be advantageous to begin by charging resin ( 3 ) or resin dispersion ( 8 ) to the mixing apparatus ( 9 ), optionally mixing this with fillers and/or additives ( 2 ), and only then adding the homogenized prepreg wastes ( 7 ). The mixture is re-homogenized in the mixing apparatus ( 9 ), and after from 5 to 15 minutes recycled BMC ( 10 ) (reBMC) is obtained as intermediate product. This can then be further processed in the hot-press process ( 11 ) to produce workpieces.
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
KEY
( 1 ) Prepreg waste
( 2 ) Fillers and/or additives
( 3 ) Resin B
( 4 ) Homogenization by cutting
( 5 ) Homogenization by shearing
( 6 ) Dispersion
( 7 ) Homogenized prepreg waste
( 8 ) Dispersion made of resin B with fillers and/or additives
( 9 ) Mixing apparatus
( 10 ) Recycled BMC
( 11 ) Further processing
(a) Addition during homogenization by cutting
(b) Addition during homogenization by shearing
(c) Addition to the mixing apparatus
(d) Addition with dispersion
EXAMPLES
Example 1: Production of reBMC with an Extruder
500 kg of residues of offcut Hexcel Hexply M21E prepreg materials—comprising only resin and fiber—with no separating film or other foreign substances are charged to an extruder, which can be a single-screw or twin-screw extruder as desired.
The material is comminuted in the extruder at about 70 rpm on a conveying screw (not a plastifying screw) with length about 1 m, L/D ratio >30 and maximal temperature 70° C.
The prepreg is charged at the ingoing end of the screw; the following are added by way of another addition slot at about 1/3 of the length: Hexcel RTM6 resin (200 kg) and further fillers, e.g. Nabaltec Apyral 40 or Magnesia 7287 (300 kg).
The remaining 2/3 of the screw length serves for mixing of the compound and homogenization of fiber length.
The material is discharged at the outgoing end of the extruder.
Finally, the material is consolidated in a press procedure in a heatable vertical press (platen press) in a divided mold (upper mold and lower mold) (cf. SMC/BMC) to produce the final component (press pressure from 120 to 140 bar, temperature 180° until material can be demolded).
Example 2: Production of reBMC with Cutter and Kneader
500 kg of residues of offcut Hexcel Hexply M21E prepreg materials, without separating film or other foreign substances, are processed in a guillotine cutter, for example an N45 from the manufacturer Pierret, to produce a generally uniform fiber length: fiber length from 12 to 24 mm. For single-ply prepreg (e.g., roll residues) it is preferable to use a cutter.
Hexcel RTM6 resin component and Nabaltec Apyral 40 or Magnesia 7287 fillers are then mixed in a Niemann Kreis-Dissolver (200 kg of resin and by way of example 300 kg of further fillers). The mixing of resin and fillers can also alternatively be achieved directly in the kneader, but the quality of the mixture is then poorer.
Premixed resin and cut prepreg are charged to a sigma kneader and mixed at from 60 to 100 rpm for about 10 min.
Finally, the material is consolidated in a press procedure in a heatable vertical press (platen press) in a divided mold (upper mold and lower mold) (cf. SMC/BMC) to produce the final component (press pressure from 120 to 140 bar, temperature 180° until material can be demolded).
Example 3: Production of reBMC with Extruder and Kneader
500 kg of residues of offcut Hexcel Hexply M21E prepreg materials, without separating film or other foreign materials, are charged to an extruder, which can be a single-screw or twin-screw extruder, as desired, and are processed therein at about 70 rpm and at most 70° C. to produce a generally uniform fiber length (stochastical fiber length distribution around a value defined via these process parameters).
Hexcel RTM6 resin component and Nabaltec Apyral 40 or Magnesia 7287 fillers are then mixed in a dissolver (for example Niemann Kreis-Dissolver) (200 kg of resin and by way of example 300 kg of further fillers). The mixing of resin and fillers can also alternatively be achieved directly in the kneader, but the quality of the mixture is then poorer.
Premixed resin and cut prepreg are charged to a sigma kneader, for example K II 450 from the manufacturer Linden, and mixed at from 60 to 100 rpm for about 10 min.
Finally, the material is consolidated in a press procedure in a heatable vertical press (platen press) in a divided mold (upper mold and lower mold) (cf. SMC/BMC) to produce the final component (press pressure from 120 to 140 bar, temperature 180° until material can be demolded). | A process for the recycling of wastes from webs or strands made of prepreg wastes comprising a first reactive resin, having the following steps: homogenization of prepreg wastes, dispersion of fillers and/or additives in a second reactive resin, mixing of the second resin, homogenized prepreg wastes and further processing of the mixture of resin, fillers and/or additives and prepreg wastes to produce molded workpieces. | 2 |
BACKGROUND OF THE INVENTION
This invention relates generally to joints in concrete slabs, and more particularly to an improved joint and method of installation to prevent concrete surface deterioration caused by spalling at edges of the joint spaces.
Concrete floor slabs having exposed surfaces subjected to repeated impact loads, such as those produced by hard wheel tires on industrial lift trucks, are susceptible to localized failure at unprotected edges of cracks and joint spaces because of the inherent brittleness and weakness of concrete in both tension and shear. The breakage and crushing type failure at the unprotected edges is generally referred to in the art as "spalling". To reduce the likelihood of edge spalling, joint spaces and cracks are routinely filled with sealant materials in an effort to avoid edge exposure. In today's market, various liquid plastics including epoxies, urethanes and polysulfides are available as joint fillers. Nevertheless, floor joints and cracks in concrete surfaces subjected to hard-wheeled traffic continue to eventually break down because of spalling, regardless of the joint or crack filler material utilized.
Concrete slab shrinkage is a well known ongoing process because of hydration and drying within the concrete mass, and is manifested by steady growth in the width of joint spaces and cracks. The filler material selected must therefore accommodate such long-term slab shrinkage by virtue of its elastic and adhesive bonding properties. While the stresses induced by slab shrinkage are resisted both in the body of certain rigid types of filler materials and at their bonding interfaces with the concrete, eventually the tensile strength of adjacent layers of concrete is exceeded to cause adjacent layer fracture or "re-cracking". Such re-cracking phenomenon creates the very same condition the filler was intended to prevent or repair, i.e., concrete edge exposure. In an attempt to avoid re-cracking failure resulting from induced stresses, a semi-rigid, low-adhesive type of filler material has been formulated, wherein the concrete bonding interfaces of the filler are adhesively weaker than the tensile strength of the filler or the concrete alone, so as to preclude re-cracking of the concrete in spaced adjacency to the filler, as aforementioned. However, filler separation or fracture at the concrete bonding interfaces then occurs in response to shrinkage induced stress resulting in edge exposure and spalling under repeated impact loading.
Various joint filler modifications other than changes in material formulation have been proposed in an effort to deal with the foregoing spalling problem, including the use of plastic divider strips in an enlarged spalling repair patch, or insert elements embedded in the filler during joint installation. For example, a filler body is held compressed by an insert element during joint installation, for subsequent expansion within the joint space according to U.S. Pat. Nos. 3,276,334 and 3,255,680 to Rhodes and Cooper et al, respectively. According to U.S. Pat. No. 4,699,540 to Gibbon, a preformed cylindrical insert is utilized to relieve any strain at the concrete bonding interfaces of the filler caused by concrete expansion. However, none of the foregoing joint filler modifications provides a completely reliable solution to the problem of eventual failure by spalling at filled joint spaces and cracks, related to the aforementioned re-cracking phenomenon caused by long term slab shrinkage.
SUMMARY OF THE INVENTION
In accordance with the present invention, the filler within a concrete crack or joint space has an insert embedded therein with means on one side thereof to enhance bonding to the filler material so as to establish a path along the other low adhesive side of the insert for separation from the filler in response to stress induced in the concrete by long-term shrinkage, for example. The adhesive strength of the bond between the insert and the filler is accordingly arranged to be less than that of the concrete bonding interfaces.
When installed, the insert has means for maintaining at least its low adhesive side spaced throughout from the side wall surfaces of the crack or joint space to be filled by the filler, in order to avoid any fracture or separation capable of weakening the concrete bonding interfaces of the filler and to ensure the maintenance of concrete edge protection by the filler against spalling. According to one embodiment, insert spacing from the concrete bonding interfaces is established by lateral projections from the insert contacting the concrete side walls of the joint space. In another embodiment, a narrow retention slot is initially cut to receive and hold the insert in position while the slot is partially widened to the joint space dimension.
Pursuant to the present invention, the aforementioned insert is embedded within the filler during establishment of the joint to prevent spalling of the concrete edges at such joint, as distinguished from repair treatment of spalling damage at an existing joint, involving enlargement of the joint space to remove the damaged surface portions of the concrete. As a result of the treatment provided by the present invention, the only separation or re-cracking occurring because of induced stress is located within the joint itself and in spaced relation to the concrete edges so that the filler edge protection remains intact.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
FIG. 1 is a side section view through a concrete slab and expansion joint in accordance with a prior art arrangement, showing spalling damage under loading and stress-induced cracking conditions.
FIG. 2 is a side section view through a concrete slab showing an expansion joint in accordance with the present invention, under loading and stress-induced cracking conditions, similar to those shown in FIG. 1, but without spalling damage.
FIGS. 3A-3D are section views of a concrete slab showing different stages in the formation of the joint shown in FIG. 2.
FIG. 4 is a partial perspective view of the insert to be embedded in the filler of the joint shown in FIGS. 2 and 3D, in accordance with one embodiment of the invention.
FIG. 5 is an enlarged partial section view taken substantially through a plane indicated by section line 5--5 in FIG. 4.
FIG. 6 is a side section view of the same joint shown in FIGS. 2 and 3D, installed between two abutting slabs.
FIGS. 7A, 7B and 7C are side section views showing different stages in the formation of an expansion joint in a concrete slab, in accordance with another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates by way of example a horizontal, concrete floor slab, generally referred to by reference numeral 10, having an upper exposed surface 12 to which moving impact loads are applied through a hard wheel 14 rolling over the surface. In an effort to pre-establish the location of all shrinkage induced fractures, such as the crack 16 shown in FIG. 1, narrow expansion joints were heretofore provided in the slab either during installation or by subsequent repair treatment, such as the expansion joint generally referred to by reference numeral 18. The expansion joint 18 is formed by a slot or joint space 20 in the concrete slab, cut to a predetermined depth and width and filled with a semi-rigid epoxy sealant material or laminant 22 in accordance with standard practice. The laminant or filler material 22 when fully cured exhibits a relatively high impact-resistant strength because of its resiliency, and completely fills the joint space so that its rigidity protects the surface edges 24 of the concrete at the intersections of the surface 12 with the side walls of the joint spaces. Low adhesive bonding interfaces 26 are formed between the filler 22 and the concrete side walls of the joint space so that re-cracking of adjacent layers of concrete is avoided. Such type of joint space filler is marketed as "MM-80 Semi-Rigid Epoxy Joint Filler" by the Metzger/McGuire Company of Concord, N.H.
The foregoing known type of expansion joint 18, while preventing stress-induced surface fracture between joints, is susceptible to adhesive rupture of the bonding interface at one side of the filler 22. Therefore, under impact loading of hard wheel traffic by wheels 14, for example, the concrete edge exposed at the surface 12 by separation or fracture 28 along one bonding interface, will rupture as shown by the spalled zone 30 in FIG. 1. If the filler material were made more adhesive and elastic to avoid fracture and separation at the bonding interface, it will not be sufficiently rigid to protect the concrete edges 24 from impact loads and spalling will also eventually occur.
In order to avoid such spalling failure, the stress-induced surface fracture is relocated within the epoxy filler itself despite its high tensile strength, in accordance with the present invention. Thus, fracture 28' as an extension of the underlying crack 16 is spaced from both of the concrete bonding interfaces 26, as shown in FIG. 2 with respect to a modified form of expansion joint 18'. The expansion joint 18' is modified in accordance with the present invention by the provision of a plastic separation strip or insert 32 extending between the lower end surface and the upper exposed end surface of a filler 22' which may be made of the same material as described for filler 22 shown in FIG. 1, or may alternatively be made of a more rigid and more adhesive material. When installed, one side 34 of the insert is roughened to enhance bonding to the filler 22' leaving the other side 36 with an adhesive bond to the filler that is less than that of the concrete bonding interfaces 26, aforementioned. Fracture 28' along such lesser adhesive side 36 of the insert 32 thereby ensures that the concrete edges 24 remain protected by the filler 22' of joint 18', to prevent spalling.
The joint 18' is formed during concrete slab installation, in accordance with the present invention, rather than as a repair treatment. As shown in FIG. 3A, the slab 10 has the joint space 20 cut therein, after which the insert 32 is positioned therein as shown in FIG. 3B. The filler 22' is then poured into the joint space and cured to its final state with the insert embedded therein, as shown in FIG. 3C. The insert 32 and filler 22' when installed project above the surface 12 as shown, and are subsequently cut flush with the surface 12 as shown in FIG. 3D. In actual practice, it may be convenient to reverse the order of insert and filler installation. That is, the filler 22' may first be poured into the joint space, with the insert 32 being pushed down into the joint while filler 22 is still liquid.
It is essential that the side surface 36 of the insert 32 be spaced throughout from the bonding interfaces 26 when the filler is installed. Toward that end, spacing projections or dimples 38 are formed on the insert and extend laterally therefrom for contact with the side walls of the joint slot 20 as more clearly seen in FIG. 3B, pursuant to one embodiment of the invention. The projections are spaced from each other and are non-aligned on opposite sides of the insert as shown in FIGS. 4 and 5 so as to accommodate free flow of the filler material in a fluent state when poured into the joint slot 20 during installation. In the particular embodiment of insert 32 shown in FIGS. 4 and 5, the insert body is made of polypropylene, with the dimple projections 38 struck out therefrom. The side surface 34 of the insert is roughened to enhance bonding by the formation of dovetail striations 42 therein.
FIGS. 7A and 7B show another method of maintaining an insert 32' spaced throughout from the concrete bonding interfaces, without any lateral projections from the insert body. Initially, a narrow retention slot 40 is cut into the slab 10 to a depth 42 as shown in FIG. 7A, dimensioned to receive the insert 32'. The slot 40 is widened to a depth 44 above 42 to form the joint space 20', as shown in FIG. 7B. The filler is then installed within joint space 20' bonding to the concrete and the insert to complete the joint 18", as shown in FIG. 7C, having the properties hereinbefore described with respect to FIGS. 2-5.
The same joint 18' as hereinbefore described with respect to FIGS. 2-5, is shown installed between abutting concrete slabs 10' and 10" in FIG. 6. The joint 18' will accordingly accommodate expansion or strain of the abutting slabs along gap 16', while protecting the concrete edges 24 against spalling by restricting formation of any fracture separation to the weaker adhesive side 34 of insert 32 as hereinbefore described.
The foregoing is considered as illustrative only of the principles of the invention. Further since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | Joint spaces within structural concrete bodies are filled with semi-rigid fillers to avoid adjacent concrete layer re-cracking and protect the concrete surface edges of the joint spaces against spalling by repeated impact loading. Inserts embedded in the fillers locationally restrict stress-induced fracture to the joint spaces and in spaced relation to the concrete bonding interfaces of the fillers so as to maintain filler protection for the concrete edges against spalling damage. | 4 |
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60/402,081 filed 9 Aug. 2002 and Ser. No. 60/442,063 dated 24 Jan. 2003.
FIELD OF THE INVENTION
[0002] This invention relates to novel photochromic and electrochromic monomers and polymers based on 1,2-dithienylcyclopentene derivatives and methods of using and synthesizing same.
BACKGROUND OF THE INVENTION
[0003] Molecules that toggle between two distinct forms when exposed to specific external stimuli, where each form exhibits unique physical properties, are promising candidates for fabricating controllable nano-devices. 1 Photochromic devices exhibit reversible variations in color when stimulated by light. 2 Few photochromic compounds possess the favourable properties displayed by the 1,2-dithienylcyclopentene skeleton, which interconverts between its colorless ring-open and colored ring-closed isomers with a high degree of fatigue resistance and bistability. 3 Photochromic compounds have many potential applications including high-density optical information storage systems, photoregulated molecular switches, reversible holographic systems, ophthalmic lenses, actinometry and molecular sensors, photochromic inks, paints and fibers and optoelectronic systems such as optical waveguides, Bragg reflectors and dielectric mirrors. 4
[0004] Electrochromic molecules which change color when electrochemically oxidized or reduced are also known in the prior art. 5 For example, electrochromic systems are used in optical display and optical shutter technology and are useful as variable-transmission filters. Electrochromic displays (ECDs) are potentially superior to cathode ray tube (CRT) and liquid crystal displays (LCDs) since they consume comparatively little power, exhibit display memory effects (i.e. persistence of an image after power is removed), and provide greater opportunities for varying image tone by applying a greater electrical charge. ECDs are also very flexible since the alignment of layers in a multi-layer device is not as critical. Composite electrochromic systems providing more flexibility in color may be readily designed. ECDs may also potentially be more useful than CRT and LCD technology for large-area displays and transmissive light modulators, such as windows and optical shutters.
[0005] Heretofore “dual mode” compounds based on 1,2-dithienylcyclopentene skeleton that are both photochromic and electrochromic due to induced ring-closing/ring-opening reactions have not been described in the prior art. 6 Such dual mode compounds would offer the opportunity to fabricate more sophisticated and versatile control systems for regulating the optical properties of products. For example, composite systems comprising multiple layers can pose particular technical challenges. If all of the layers are solely photochromic, the light energy will be filtered once the first surface layer is colored and the likelihood of light penetrating all of the interior layers is low. Moreover, an interior layer cannot be independently addressed using light alone unless the system is capable of two-photon-mode photochromism. Electrochromism provides a means to access each layer individually since a multilayer device can be constructed of individual insulated electrode films. Many other applications may envisaged where it would be convenient to reversible change the color of a product by both photochromic and electrochromic means. It would be particularly advantageous if the electrochromic trigger could be implemented in a catalytic electrochemical process to minimize the required energy input.
[0006] The need to incorporate photochromic and electrochromic molecules into workable materials such as films, sheets, fibers or beads demands them to be in polymeric rather than monomeric forms. 7 Ring-Opening Methathesis Polymerization (ROMP) is an ideal method for synthesizing functional polymers with narrow molecular weight distributions due to the mild reaction conditions needed and its compatibility with a wide range of functional groups. 8 In addition, the polymer chain length can be readily tailored by varying the catalyst/monomer ratio. The versatility of ROMP for generating photochromic polymers, including polymers having a variety of pendant functional groups, is described in the Applicant's PCT application No. PCT/CA01/01033 (WO 02/06361) which is hereby incorporated by reference. As described in the '033 application, homopolymers (i.e. polymers derived from one species of monomer) are more desirable than copolymers as they will have an increased density of the photochromic unit within the material. 9 This translates into a greater amount of information expressed or stored per unit volume or surface. While the photochromic homopolymers described in the '033 application are very useful, the density of the homopolymers is limited by the fact that the active photochromic component is located on a side chain of the polymer. In order to create ultra-high density homopolymers it would be desirable if the active component could be arranged directly on the main-chain or backbone of the polymer. A need has therefore arisen for dual mode compounds having physical properties which may be controlled be controlled both photochemically and electrochemically and improved homopolymers having a more dense arrangement of active chromic components, both in solution and in solid-state forms.
SUMMARY OF THE INVENTION
[0007] The invention relates to a compound selected from the group consisting of compounds reversibly convertible under photochromic and electrochromic conditions between a ring-open isomer (I) and a ring-closed isomer (II):
wherein R 1 is selected from the group consisting of H and a halogen; R 2 is selected from the group consisting of H, a halogen, CH═CH and a polymer backbone; R 3 is selected from the group consisting of H, a halogen, CO 2 Y (Y=H, Na, alkyl, aryl), and
(X=N,O,S); R 4 is selected from the group consisting of alkyl and aryl; and R 5 is selected from the group consisting of H, alkyl and aryl. In one embodiment of the invention R 1 and R 2 are preferably F. In another embodiment R 1 is H and R 2 forms part of a cyclic structure (i.e. R 2 is CH═CH).
[0008] The compounds of the group described above are “dual mode” since they are both photochromic and electrochromic under appropriate conditions. For example, a selected compound may be convertible from the ring-open isomer (I) to the ring-closed isomer (II) under photochromic conditions and from the ring-closed isomer (II) to the ring-open isomer (I) under electrochromic conditions. Conversely, the compound may be convertible from the ring-closed isomer (II) to the ring-open isomer (I) under photochromic conditions and from the ring-open isomer (I) to the ring-closed isomer (II) under electrochromic conditions. Moreover, the interconversion between the isomeric forms may be both photochromic and electrochromic depending upon what reaction conditions are selected. For example the compound may be convertible from the ring-closed (II) isomer to the ring-open isomer (I), or vice versa, under both photochromic and electrochromic conditions.
[0009] Preferably the electrochromic interconversion is catalytic. For example, oxidation of the ring-closed isomer (II) may result in the formation of a radical cation. The cation undergoes a rapid ring-opening reaction to produce the radical cation of the ring-open isomer (I) which in turn readily accepts an electron from another molecule of the ring-closed molecule (II). Continuation of this oxidize/ring-open/reduce cycle will eventually result in the complete conversion of (II) to (I).
[0010] The compounds of the invention may be in either a monomeric or polymeric form. The polymeric form may be a homopolymer produced by ring-opening methathesis polymerization (ROMP). The homopolymer may include the active photochromic component as either a side-chain or the main-chain of the polymer. In the latter case the central ring of the photochromic 1,2-bis(3-thienyl)cyclopentene may be incorporated directly into the polymer main-chain to form an ultra-high density polymer interconvertible between isomeric forms (III) and (IV) as shown below:
where R 3 is as described above and may, for example, consist of halogen, CO 2 CH 3 or CO 2 H.
[0011] Methods of synthesizing the compounds of the invention and using the compounds in photonic and/or optoelectronic applications are also described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In drawings which illustrate embodiments of the invention but which should not be construed to limit the scope of the invention:
[0013] FIG. 1 is a graph of changes in the UV-Vis absorption spectrum of a CH 2 Cl 2 solution of 1,2-bis(2,5-bis(2-thienyl)-3-thienyl)hexafluorocyclopent-1-ene (compound 1) (2×10 −5 M) upon irradiation with 365 nm light. Irradiation periods are every 5 seconds until a 50 second period was reached. The dotted trace ( . . . ) is the spectrum after photobleaching the solution by irradiation with >490 nm light.
[0014] FIGS. 2 ( a )- 2 ( c ) are cyclic voltammograms of a CH 3 CN solution (1×10 −3 M) of (a) compound 1 and (b) compound 1′ at a scan rate of 200 mV/s with 0.1 M NBu 4 PF 6 as the supporting electrolyte. Graph (c) shows the partial cyclic voltammogram of a CH 3 CN solution (1×10 −3 M) of 1′ at scan rates of 50, 100, 150, 200, 250, 300, 350, 400, 450, and 500 mV/s. A platinum disk working electrode, a Ag/AgCl (in saturated NaCl) reference electrode and a platinum wire counter electrode were used. Ferrocene was added as an internal reference (0.405 V vs SCE).
[0015] FIG. 3 is a graph of the UV-Vis absorption spectra of a CH 2 Cl 2 solution (2×10 −5 M) containing 75% of 1′ before addition of the radical cation [(4-BrC 6 H 4 ) 3 N][SbCl 6 ]( - - - ) and after addition of one mole % [(4-BrC 6 H 4 ) 3 N][SbCl 6 ](—).
[0016] FIG. 4 is a series of photographs showing a gradual color change of a CH 2 Cl 2 solution of compound 1 containing 75% of the ring-closed isomer 1′ when treated with a catalytic amount of [(4-BrC 6 H4) 3 N][SbCl 6 ].
[0017] FIG. 5 is a graph of the UV-VIS absorption spectra of 1,2-bis(2,2′-bithien-3-yl)hexafluorocyclopent-1-ene (compounds 2 and 2′) at the photostationary state containing 38% 2′. The spectra were of CH 2 Cl 2 solutions at 2×10 −5 M. The photostationary state was obtained by irradiating a solution of 2 with 313 nm light until no spectral changes were observed.
[0018] FIG. 6 are cyclic voltammograms of compounds 2 (top) and 2′ (bottom) using 1×10 −3 M CH 3 CN solutions of both isomers at a scan rate of 200 mV/s with 0.1 M NBu 4 PF 6 as the supporting electrolyte. A platinum disk working electrode, a Ag/AgCl (in saturated NaCl) reference electrode and a platinum wire counter electrode were used.
[0019] FIGS. 7 ( a ) and ( b ) are graphs showing the UV-Vis absorption spectra of CH 2 Cl 2 solutions (2×10 −5 M) of the ring-open (—) and ring-closed ( - - - ) forms of (a) 2-bis(2,5-diphenylthien-3-yl)-hexafluorocyclopent-1-ene (compound 3) and (b) 1,2-bis(2-phenyl-3-thienyl)hexafluorocyclopent-1-ene (compound 4). The ring-closed forms were generated by irradiating with 365 nm (compound 3) and 313 nm (compound 4) light until the photostationary state was reached which consisted of 42% and 27% of the ring-closed 3′ and 4′, respectively.
[0020] FIGS. 8 ( a ) and ( b ) are cyclic voltammograms of (a) a CH 2 Cl 2 solution (1×10 −3 M) of 3 before irradiation (top) and after irradiation (bottom) with 365 mm light for 5 minutes and (b) a CH 3 CN solution (1×10 −3 M) of compound 4 before irradiation (top) and after irradiation (bottom) with 313 nm light for 2 minutes. All voltammograms were performed at a scan rate of 200 mV/s with NBu 4 PF 6 as the supporting electrolyte. The inset in (a) magnifies the region of the bottom voltammogram between 0.7 and 1.20 V. The inset in (b) magnifies the region of the bottom spectrum between 0.7 and 1.02 V. A platinum disk working electrode, a Ag/AgCl (in saturated NaCl) reference electrode and a platinum wire counter electrode were used.
[0021] FIG. 9 is a graph of the UV-Vis absorption spectra of a CH 2 Cl 2 solution of 1,2-bis(2-methyl-5,5′-dithiophen-3-yl)perfluorocyclopent-1-ene (compounds 5 and 5′) at the photostationary state containing >97% 5′. The spectra were of CH 2 Cl 2 solutions at 2× 10 −5 M. The photostationary state was obtained by irradiating a solution of 5 with 365 nm light until no spectral changes were observed.
[0022] FIGS. 10 ( a ) and 10 ( b ) are cyclic voltammograms of a CH 3 CN solution (1×10 −3 M) of (a) compound 5 (top trace), 5′ (bottom trace), (b) compound 6 (top trace) and 6′ (bottom trace). The inset in (a) shows the cyclic voltammogram of five redox cycles of 5. In all cases, a scan rate of 200 mV/s was used. A platinum disk working electrode, a Ag/AgCl (in saturated NaCl) reference electrode and a platinum wire counter electrode with 0.1 M NBu 4 PF 6 as the supporting electrolyte were used.
[0023] FIGS. 11 ( a )-( d ) are UV-Vis absorption spectra showing changes in the spectra upon irradiation of (a) 2,3-bis(3-(2-methyl-5-carboxymethylthienyl))bicyclo[2.2.1]hept-2,5-diene (monomer 8) in solution (THF), (b) polymer 11 in solution (THF), (c) polymer 11 cast as a film, and (d) polymer 12 in solution (pH 7 KH 2 PO 4 /K 2 HPO 4 buffer) with 313 nm light (254 nm for monomer 8). Irradiation periods for the solution studies are 0, 2, 6, 12, 20, 30, 45, 65, 90 and 120 s. Irradiation periods for the studies on the polymer film are 0, 2, 6, 12, 20, 30, 45, 65, 90, 120, 155, 195, 240, 290 s.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Throughout the following description specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the present invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
[0025] This application relates to 1,2-dithienylcyclopentene derivatives having the general structure shown in Scheme 1 below:
[0026] As described in detail below, this application also relates to methods of synthesizing and using the compounds, including both polymer and monomer precursors.
[0027] The compounds are reversibly convertible between the ring-open isomer (I) and the ring-closed isomer (II) under photochemical and/or electrochemical conditions. For example, reversible photocyclization between the ring-open and ring-closed forms (I, II) may occur when the compounds are irradiated with the appropriate wavelengths of light or electrochemically oxidized or reduced. For example, some compounds undergo photochemical ring-closing (with UV light) and both photochemical (with visible light) and electrochemical (oxidation) ring-opening. Conversely other compounds undergo photochemical ring-opening under photochemical conditions and ring-closing under both photochemical and electrochemical conditions. Accordingly, some of the compounds exhibit a dual-mode action combining both photochromism and electrochromism. As used in this patent application “photochromism” refers to the capacity of a compound to reversibly change color when subjected to radiant energy and “electrochromism” refers to the capacity to change color when subjected to a positive or negative charge. The general methodology for synthesizing the fluorinated derivatives of the invention is shown in Scheme 2. In this case octafluorocyclopentene is used as a reagent and R 1 and R 2 are F.
[0028] As shown Table 1, and as described in detail below, the following fluorinated monomeric compounds have been shown synthesized using the methodology of Scheme 2 and have been shown to exhibit both photochromic and electrochromic properties
TABLE 1 Compound R 1 , R 2 R 3 R 4 R 5 1 F H x = S x = S 2 F H H x = S 3 F H 4 F H H 5 F CH 3 H x = S 6 F CH 3 H x = S
[0029] As discussed above, the need to incorporate these compounds into workable materials such as films, sheets, fibers or beads demands that the compounds be in polymeric rather than monomeric forms. The fluorinated compounds may be polymerized using ring-opening methathesis polymerization (ROMP) as described in Patent Cooperation Treaty application No. PCT/CA01/01033 (WO 02/06361) and as shown generally in Scheme 3 below:
[0030] Another significant advantage of the invention is that the electrochromism of the photochromic compounds described herein is catalytic as shown in Scheme 4 below.
[0031] In particular, in an electrochemical cell the ring-closed form (II) loses an electron to the anode (i.e. it is oxidized) and forms its radical cation. This radical cation undergoes a rapid ring-opening reaction to produce the radical cation of isomer (I). Because the neutral form of isomer (I) requires a substantially more positive potential to undergo oxidation (1.27 V), its radical cation immediately oxidizes a neighboring molecule of (II) and is effectively neutralized. Accordingly, only a small amount of the ring-closed form (II) needs to be oxidized because this will ring-open to (I), which will subsequently remove an electron from another molecule of (II) regenerating its radical cation. The continuation of this oxidize/ring-open/reduce cycle will eventually result in the complete conversion of (II) to (I).
[0032] The fact that the conversion between photochromic forms may be catalysed electrochemically may be advantageous in many applications of the invention, such as thin film displays. First, the need for diffusion of counterions is minimized which is often a kinetic bottleneck in conventional electrochromic systems. For example, in the case of an oxidation process, anions must be incorporated from the surrounding medium or cations must be ejected from the film to maintain charge balance. Typically this is accomplished by adding a secondary electrochrome and a charge-carrying layer to the system. This step is not required in the present case. The catalytic system needs minimal movement of ions because there is no net change in charge in the reactions or a buildup of charge. As described above, when the radical cation of the ring-open isomer forms, it removes an electron from a neighbouring molecule of the ring-closed isomer and hence the process will propagate throughout the entire system. Secondly, the catalytic process is very energy efficient since only a small amount of charge needs to be applied to initiate the catalytic cycle. Thirdly, the colouration value will be very large. The colouration value is proportional to the change in absorpitivity and inversely proportional to the charge injected per unit area. This is particularly important when constructing devices from indium tin oxide (ITO) electrodes which are semiconducting and have a very small number of charge carriers. In the case of films, very thin films such as monolayers do not contain a sufficient amount of active material to generate a satisfactory change in optical absorbance. Thicker films would require the diffusion of ions through all of the layers. The catalytic system of the present invention does not require diffusion since the transfer process can be relayed throughout the entire film. In other words the electrochemical trigger does not need to be highly efficient since it is only required to initiate the catalytic cycle.
[0033] The general methodology for synthesizing the non-fluorinated dithienylalkene derivatives using 2,3-dibromobicyclo[2.2.1]hepta-2,5-diene as a reagent is shown in Scheme 5 below.
[0034] As shown in Table 2, and as described in detail below, the following non-fluorinated monomeric and polymeric compounds have been shown synthesized using the methodology of Scheme 5.
TABLE 2 Compound R 1 R 2 R 3 R 4 R 5 7 H HC═CH Cl CH 3 H 8 H HC═CH CO 2 CH 3 CH 3 H 9 H HC═CH CH 3 H x = S 10 H HC═CH Cl CH 3 H polymer backbone 11 H HC═CH CO 2 CH 3 CH 3 H polymer backbone 12 H HC═CH CO 2 H CH 3 H polymer backbone 13 H HC═CH polymer backbone CH 3 H x = S
[0035] An important advantage of the polymerization approach shown in Scheme 5 (for example, yielding polymerized compounds 10, 11 12 and 13) is that the cyclopentene ring of the 1,2-bis(3-thienyl)cyclopentene unit is incorporated directly into the polymer backbone. This results in a polymer having an ultra-high density of active photochromic/electrochromic components (i.e. higher densities are achieved by decreasing the size of the linker that connects the dithienylethene to the polymer backbone). Higher density polymers offer the opportunity to express or store a greater amount of information per unit volume or surface area. For example, the percent mass of the active photochromic component in the side-chain polymers shown in Scheme 3 ranges from 60-68%. By way of comparison, the new generation main-chain polymers of Scheme 5 have a percent mass of the active photochromic component ranging up to 93%. This is primarily due to the ROMP reaction of the strained olefin producing the requisite cyclopentene backbone that has been shown to be very versatile. As described below, both lipophilic and hydrophilic versions of the polymers have been prepared.
[0036] As described below, the photochromic polymers of Table 2 have been shown to undergo induced isomerization both in solution and in solid state form. These functional polymers are therefore well suited for incorporation into workable materials such as films, sheets, fibers or beads.
EXAMPLES
[0037] The following examples will further illustrate the invention in greater detail although it will be appreciated that the invention is not limited to the specific examples.
Experimental Methods
[0038] All solvents were dried and degassed by passing them through steel columns containing activated alumina under nitrogen using an MBraun solvent purification system. Solvents for NMR analysis (Cambridge Isotope Laboratories) were used as received. All synthetic precursors were purchased from Aldrich with the exception of Pd(PPh 3 ) 4 and bis(tricyclohexylphosphine)benzylidene ruthenium(IV)dichloride (Grubb's catalyst) which were purchased from Strem. Octafluorocyclopentene was obtained from Nippon Zeon Corporation. Column chromatography was performed using silica gel 60 (230-400 mesh) from Silicycle Inc.
[0039] 1 H NMR characterizations were performed on a Bruker AMX 400 instrument working at 400.103 MHz. 13 C NMR characterizations were performed on a Bruker AMX 400 instrument working at 100.610 MHz. Chemical shifts (δ) are reported in parts per million relative to tetramethylsilane using the residual solvent peak as a reference standard. Coupling constants (J) are reported in Hertz. FT-IR measurements were performed using a Nexus 670 or a Nicolet Magna-IR 750 instrument. UV-VIS measurements were performed using a Varian Cary 300 Bio spectrophotometer. Low resolution mass spectrometry measurements were performed using a HP5985 with isobutane as the chemical ionization source.
[0040] Standard lamps used for visualizing TLC plates (Spectroline E-series, 470 μW/cm 2 ) were used to carry out the ring-closing reaction of all photochromic compounds using a 365-nm, a 313-nm or a 254-nm light source when appropriate. The compositions of all photostationarty states were detected using 1 H NMR spectroscopy. The ring-opening reactions were carried out using the light of a 150-W tungsten source that was passed through a 490-nm or a 434-nm cutoff filter to eliminate higher energy light.
[0041] As used herein, a bold numeral (e.g. 1) denotes the ring-open isomeric form of a compound and a bold, primed numeral (e.g. 1′) denotes the ring-closed isomeric form of the same compound.
Example 1
1.1 Synthesis of 1,2-bis(2,5-bis(2-thienyl)-3-thienyl)hexafluorocyclopent-1-ene (Compound 1)
[0042]
[0043] A solution of 3′-bromo-2,2′;5′2′terthiophene (0.749 g, 2.3 mmol) in anhydrous Et 2 O (25 mL) cooled to −20° C. was treated with n-BuLi (0.91 mL of a 2.5 M solution in hexane) dropwise under an argon atmosphere. After stirring the solution for 30 min, octafluorocyclopentene (0.13 mL, 1.15 mmol) was added dropwise using a cooled gas tight syringe and the solution immediately turned dark red in colour. After stirring for 1 h, the cooling bath was removed and the solution was allowed to warm to room temperature and stirred for 16 h when it was quenched with 5% HCl (10 mL). The aqueous layer was separated and extracted with Et 2 O (2×10 mL). All organic extracts were combined, washed with H 2 O (2×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 175 mg of pure product as a yellow crystalline solid. Yield: 23%.
[0044] M.p. 116-117° C.; 1 H NMR (300 MHz, CD 2 Cl 2 ) δ7.30 (dd, J=5, 1 Hz, 2H), 7.19 (dd, J=5, 1 Hz, 2H) 7.11 (dd, J=4, 1 Hz, 2H), 7.04 (dd, J=5, 4 Hz, 2H), 6.83 (dd, J=5, 3 Hz, 2H), 6.74 (dd, J=3, 1 Hz, 2H), 6.41 (s, 2H); 13 C NMR (125 MHz, CD 2 Cl 2 ) δ 137.9, 136.3, 136.2, 133.0, 128.3, 128.2, 127.9, 127.0, 125.7, 125.0, 124.9, 123.8 (12 of 15 carbons found); FT-IR (CHCl 3 cast) 3105, 1695, 1685, 1651, 1644, 1616, 1576, 1561, 1538, 1505, 1467, 1415, 1384, 1328, 1274, 1244, 1225, 1191, 1130, 1096, 1046, 1028, 976, 952, 877, 833, 757, 696, 581, 553, 472, 458 cm −1 ; HRMS (EI) Calcd for M + (C 29 H 14 F 6 S 6 ): 667.9324. Found: 667.9337.
1.2 Synthesis of the Ring-Closed Form 1′.
[0045]
[0046] Compound 1 (5 mg) was dissolved in CH 2 Cl 2 (20 mL) and placed in a quartz glass cell. The solution was irradiated at 365 nm for 10 min. The solvent was evaporated off under reduced pressure and the crude product was recrystallized (hexanes) to afford the pure product as a blue powder.
[0047] 1 H NMR (500 MHz, CD 2 Cl 2 ) δ 7.49 (d, J=5 Hz, 2H), 7.38 (dd, J=4, 1 Hz, 2H), 7.30 (dd, J=5, 1 Hz, 2H), 7.28 (d, J=4 Hz, 2H), 7.07 (dd, J=5, 4 Hz, 2H), 6.92 (dd, J=5, 4 Hz, 2H), 6.58 (s, 2H).
1.3 UV-VIS Spectroscopy of Compound 1
[0048] Irradiation of a CH 2 Cl 2 solution (2×10 −5 M) of compound 1 with 365 nm light resulted in an immediate increase in the absorption band in the visible spectral region (λ max =632 nm) due to the production of the ring-closed isomer 1′ of compound 1 ( FIG. 1 ). A visual change in colour from light yellow to blue accompanied this transformation. Subsequent irradiation of the solution with visible light (greater than 490 nm) resulted in the complete disappearance of the absorption band at 632 nm and regeneration of the original UV-VIS absorption trace representing the ring-open isomer 1.
1.4 Thermal Stability of the Ring-Closed Isomer 1′
[0049] The thermal stability of the ring-closed isomer 1′ was studied by storing a sample containing 80% of the ring-closed isomer 1′ (i.e. the photostationary state) in CD 2 Cl 2 at room temperature in the dark. 1 H NMR analysis was performed on this solution periodically and the ring-closed isomer 1′ was thermally stable at 25° C. for over one month.
1.5 Cyclic Voltammetry of 1 and 1′
[0050] The cyclic voltammogram of ring-open isomer 1 shows an irreversible oxidation peak at 1.27 V for all scan rates tested (50-3000 mV/s) ( FIG. 2 a ). The voltammogram of the ring-closed isomer of compound 1′, obtained after irradiation of a CH 3 CN (1×10 −3 M) solution of compound 1 with 365 nm light for 5 minutes, showed a very small irreversible oxidation peak at 0.85 V that is almost too small to measure ( FIG. 2 b ). Increasing the sweep rate in the cyclic voltammetry experiments resulted in a subsequent increase in the intensity of the oxidation peak at 0.85 V. However, there is insignificant growth in the reduction peak on the return sweep ( FIG. 2 c ). This implies that the rate of the ring-opening reaction of the radical cation compound 1′ (+•) is faster than the limitations of our instrument. The sweep rate was increased up to a maximum speed of 5000 mV/s without a significant change in the intensity of the reduction peak on the return sweep.
1.6 Catalytic Ring-Opening of Compound 1′ Monitored Using UV-VIS Absorption Spectroscopy
[0051] A CH 2 Cl 2 solution of ring-open isomer 1 was irradiated with 365 nm light until 75% of the ring-closed form 1′ was produced as determined by 1 H NMR spectroscopy. The UV-VIS absorption spectrum of a CH 2 Cl 2 solution containing 75% of the ring-closed isomer 1′ is shown in FIG. 3 . An aliquot of a CH 2 Cl 2 solution (2×10 −5 M) of the one-electron-accepting radical cation [(4-BrC 6 H 4 ) 3 N][SbCl 6 ] (E ox =1.15 V), corresponding to one mol % was added to the blue CH 2 Cl 2 solution containing 75% of the ring-closed isomer 1′. The V-VIS absorption spectrum taken immediately after the addition of one mol % of [(4-BrC 6 H 4 ) 3 N][SbCl 6 ] showed the complete disappearance of the absorption band in the visible region (λ max =632 nm) corresponding to the ring-closed isomer 1′ and regeneration of the spectrum that is consistent with the ring-open isomer 1 ( FIG. 3 and FIG. 4 ). Irradiation of the solution with 365 nm light resulted in no change of the UV-Vis spectrum, which would accompany the formation of the ring-closed product, since the radical cation [(4-BrC 6 H 4 ) 3 N][SbCl 6 ] still remained in solution. Inducing the ring-opening reaction using a catalytic amount of the chemical oxidant was very efficient since only a small percent was needed to initiate the ring-opening process.
1.7 π-Conjugation
[0052] The π-electrons are delocalized throughout the photochromic backbone only in the ring-closed state 1′ due to the linearly π-conjugated pathway that is created upon photocyclization. On the other hand, these electrons are forced to reside on the two thiophene rings in the ring-open form 1 due to the lack of linear π-conjugation between the two heterocycles. Therefore, any π-electrons of the two R 3 groups can only interact with each other through the conjugated pathway in the ring-closed state 1′. Accordingly, incorporating the photochromic dithienylethene backbone into polyene molecular wires should permit the reversible switching of conductive properties by photoirradiation. Although there are several reports that describe how this structural modification can regulate electronic communication between various R 3 substituent groups, the inventors are unaware of any that take advantage of the skeletal alteration between the groups R 3 and R 4 within the two isomers: upon photochemical ring closure, the two carbon atoms involved in forming the new single bond (the 2′-positions of the heterocycles) change their hybridization from sp 2 to sp 3 .
[0053] In accordance with the invention two terthiophene units have been modified so that the central thiophene rings of each make up the photochromic dithienylethene backbone. Because oligo and polythiophenes display promising semi-conducting properties and are being considered as prototype molecular-scale wires, the inventors chose to use terthiophene as a model oligothiophene to incorporate into the photochromic 1,2-dithienylcylcopentene. Complete delocalization of the π-electrons in this manner results in the ring-closed structure 1′. Using this approach, π-conjugation is not just regulated on command, but also re-routed.
[0054] Single crystals of compound 1 suitable for X-ray crystallographic analysis were grown by slowly cooling a hot hexane solution of the compound. The structure of 1 in the crystal reveals that the two peripheral heterocycles of each terthiophene are rotated an average of 20° and 48° for the outer and inner rings respectively. Despite this deviation from coplanarity with the central heterocycle in the solid-state, the recorded UV-Vis absorption spectra, described above, show that, in solution, π-conjugation is still extended throughout each terthiophene arm of the photochromic system.
[0055] This work clearly demonstrates that while the ring-open isomer 1 has two π-conjugated terthiophene arms, the ring-closed isomer 1′ has the linearly π-conjugated pathway extending throughout the backbone of the photochrome. The original conjugated pathways have been destroyed. This is clearly evidenced by the similarity of the absorption spectrum in the visible region between the ring-closed forms of 1′ and 5′ (described further below), the latter possessing an identical linear π-conjugation backbone but is lacking the additional thiophene heterocycles. The absorption spectra of ring-open 1 and 5 are different due to the extended conjugation in 1 as compared to 5.
[0056] Similar principles apply in respect of the other compounds described below where R 3 and R 4 are aryl.
Example 2
2.1 Synthesis of 1,2-bis(2,2′-bithien-3-yl)hexafluorocyclopent-1-ene (compound 2).
[0057]
[0058] A solution of 3-bromo-[2,2′]bithiophenyl (0.500 g, 2.3 mmol) in anhydrous Et 2 O (25 mL) cooled to −20° C. was treated with n-BuLi (0.82 mL of a 2.5 M solution in hexane) dropwise under an argon atmosphere. After stirring the solution for 30 min, octafluorocyclopentene (0.13 mL, 1.0 mmol) was added dropwise using a cooled gas tight syringe and the solution immediately turned dark red. After stirring at this temperature for 1 h, the cooling bath was removed and the reaction mixture was allowed to warm to room temperature and stirred for 16 h when it was quenched with 5% HCl (5 mL). The aqueous layer was separated and extracted with Et 2 O (2×10 mL). All organic extracts were combined, washed with H 2 O (2×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 75 mg of pure product as a white solid. Yield: 8%.
[0059] M.p. 160-162° C.; 1 H NMR (400 MHz, CD 2 Cl 2 ) δ 7.23 (dd, J=5, 1 Hz, 2H), 7.03 (d, J=5 Hz, 2H), 6.89 (dd, J=5, 4 Hz, 2H), 6.64 (dd, J=4, 1 Hz, 2H), 6.41 (d, J=5 Hz, 2H); 13 C NMR (125 MHz, CDCl 3 ) δ 137.1, 133.2, 127.7, 127.5, 126.9, 126.3, 125.4, 124.3 (8 of 11 carbons found); FT-IR (CH 2 Cl 2 cast) 3110, 2924, 2841, 1337, 1275, 1241, 1189, 1130, 1088, 963, 942, 852, 737, 699, 651 cm −1 ; LRMS (CI) Calcd for M + (C 21 H 10 F 6 S 4 ) 504. Found: 505 [M+H] + . Anal. Calcd for C 21 H 10 F 6 S 4 : C, 49.99; H, 2.00. Found: C, 50.40; H, 2.11.
2.2 Synthesis of the Ring-Closed Form 2′
[0060]
[0061] Compound 2 (10 mg) was dissolved in CH 2 Cl 2 (20 mL) and placed in a quartz glass cell. The solution was irradiated with 313 nm light for 4 min. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes:CH 2 Cl 2 , 9:1) to afford pure 2′ as a purple solid.
[0062] 1 H NMR (600 MHz; CD 2 Cl 2 ) δ7.42 (dd, J=3.6, 1.2 Hz, 2H), 7.34 (dd, J=4.8, 1.2 Hz, 2H), 7.14 (d, J=6.0 Hz, 2H), 6.96 (dd, J=5.4, 1.2 Hz, 2H), (d, J=5.4 Hz, 2H), 6.28 (d, J=6.0 Hz, 2H).
2.3 UV-VIS Spectroscopy of Compound 2.
[0063] The bis(dithiophene) 2 exhibits a low-energy absorption band at λ max =320 nm ( FIG. 5 ). The absorption band of bis(dithiophene) 2′ appears at λ max =545 nm after irradiation of a CH 2 Cl 2 solution (2×10 −5 M) with 313 nm light and reaches a photostationary state of 38% in CD 2 Cl 2 (1×10 −3 M) as monitored by 1 H NMR spectroscopy ( FIG. 5 ).
2.4 Cyclic Voltammetry of Compound 2
[0064] The voltammogram of 2 shows an irreversible oxidation peak at 1.54 V. Irradiation of the solution of 2 with 313 nm light generated 38% of the ring-open isomer (as determined by 1 H NMR spectroscopy) and the cyclic voltammogram shows a small irreversible oxidation peak at 1.16 V due to the ring-closed isomer 2′ ( FIG. 6 ).
Example 3
3.1 Synthesis of the 1,2-bis(2,5-diphenylthien-3-yl)-hexafluorocyclopent-1-ene (compound 3)
[0065]
3.1.1 Synthesis of 3-bromo-2,5-diphenylthiophene (BT1)
[0066] Phenylboronic acid (0.756 g, 6.2 mmol) was added to flask containing deoxygenated THF (10 mL) and a 20% w/w Na 2 CO 3 solution (10 mL) under a nitrogen atmosphere and stirred vigorously. 2,3,5-tribromothiophene (1.022 g, 3.1 mmol) and Pd(PPh 3 ) 4 (0.107 g, 0.096 mmol) were added and the solution was heated at reflux under a nitrogen atmosphere for 24 h. The heat source was removed, the reaction mixture was allowed to cool to room temperature and extracted with CH 2 Cl 2 (3×20 mL). The combined organic extracts were washed with H 2 O (2×20 mL) followed by brine (2×20 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 0.553 g of pure product as a white solid. Yield: 57%.
[0067] M.p. 43-44° C.; 1 H NMR (400 MHz, CD 2 Cl 2 ) δ7.72-7.69 (m, 2H), 7.63-7.60 (m, 2H), 7.49-7.32 (m, 7H), 7.31 (s, 1H); 13 C NMR (100 MHz; CDCl 3 ) δ 143.2, 137.3, 133.1, 132.8, 129.0, 128.9, 128.5, 128.3, 128.2, 127.4, 107.9 (11 of 16 carbons found); FT-IR (CH 2 Cl 2 cast) 3062, 3014, 1600, 14844, 1443, 1326, 1076, 1028, 825, 759, 756, 690 cm −1 ; LRMS (CI) Calcd for M + (C 16 H 11 BrS): 314. Found: 317 ([M+H] + , [ 81 Br], 100%), 315 ([M+H] + , [ 79 Br], 94%); Anal. Calcd for C 16 H 11 BrS: C, 60.96; H, 3.32. Found: C, 61.11; H, 3.56.
3.1.2 Synthesis of the 1,2-bis(2,5-diphenylthien-3-yl)-hexafluorocyclopent-1-ene (compound 3)
[0068] A solution of 3-bromo-2,5-diphenylthiophene (0.200 g, 0.63 mmol) in anhydrous Et 2 O (10 mL) cooled to −20° C. was treated with n-BuLi (0.25 mL of a 2.5 M solution in hexane) dropwise under a nitrogen atmosphere. A white precipitate formed after stirring for 5 min. This reaction mixture was stirred at −20° C. for a total of 15 min followed by addition of octafluorocyclopentene (40 μL, 0.31 mmo) using a cooled gas tight syringe. The precipitate remained therefore anhydrous THF (3 mL) was added to dissolve the precipitate. After stirring for 30 min, the cooling bath was removed and the reaction was allowed to warm to room temperature and stirred for 1 h when it was quenched with 5% HCl (5 mL). The aqueous layer was separated and extracted with Et 2 O (2×10 mL). All organic extracts were combined, washed with H 2 O (2×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 59 mg of pure product as a yellow crystalline solid. Yield: 30%.
[0069] M.p. 223-225° C.; 1 H NMR (400 MHz, CD 2 Cl 2 ) δ 7.38 (m, 8H), 7.33 (m, 2H), 7.09 (m, 6H), 7.01 (m, 6H), 6.31 (s, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ 144.3, 143.7, 133.3, 132.3, 128.7, 128.7, 128.0, 127.8, 127.8, 125.6, 124.4, 122.8 (12 of 15 carbons found); FT-IR (CH 2 Cl 2 cast) 3069, 3014, 2924, 1600, 1490, 1448, 1324, 1269, 1186, 1124, 1097, 979, 924, 751, 690 cm −1 ; LRMS (CI) Calcd for M + (C 37 H 22 F 6 S 2 ): 644. Found: 645 [M+H] + . Anal. Calcd for C 37 H 22 F 6 S 2 : C, 68.93; H, 3.44. Found: C, 69.20; H, 3.50.
3.1.3 Synthesis of the Ring-Closed Form 3′
[0070]
[0071] Compound 3 (0.8 mg) was dissolved in CD 2 Cl 2 (1.2 mL) and placed in an NMR tube. The solution was irradiated with 365 nm light for 4 min. This resulted in a photostationary state containing 42% of the ring-closed isomer 3′.
[0072] 1 H NMR (600 MHz, CD 2 Cl 2 ) δ 7.80 (d, J=7.2 Hz, 4H), 7.44 (d, J=6.0 Hz, 4H), 7.40-7.38 (m, 8H), 7.23 (m, 2H), 6.69 (s, 2H).
3.2 UV-VIS Absorption Spectroscopy of Compound 3
[0073] Upon irradiation of a CH 2 Cl 2 solution (2×10 −5 M) of compound 3 using 365 nm light, the colourless ring-open isomer 3 (λ max =292 nm) was converted to the blue ring-closed isomer 3′ (λ max =604 nm) ( FIG. 7 a ). 1 H NMR spectroscopic analysis of the ring-closing reaction determined that the photostationary state contained 42% of the ring-closed isomer 3′ when a CD 2 Cl 2 solution of 3 was irradiated with 365 nm light for 2 minutes.
3.3 Cyclic Voltammetry of 3
[0074] The cyclic voltammogram of a CH 2 Cl 2 solution (1×10 −3 M) of compound 3 shows an irreversible oxidation peak at 1.62 V due to the oxidation of the ring-open isomer ( FIG. 8 a ). Irradiation of the solution with 365 nm light generated the blue ring-closed isomer and the cyclic voltammogram of this solution showed a very small irreversible oxidation peak at 0.89 V which is assigned to the ring-closed isomer 3′.
3.4 Electrochemical Ring-Opening of 3′
[0075] Electrolysis of CD 3 CN solutions (1×10 −3 M) containing the blue ring-closed isomer 3′ at 1.0 V resulted in decolourization of the solutions and 1 H NMR analysis showed that complete conversion from the ring-closed isomer 3′ to the ring-open isomer 3 resulted. Addition of only 2 mol % of the catalyst [(4-BrC 6 H 4 ) 3 N][SbCl 6 ] to a solution containing 3′ at the photostationary state (as determined by UV-VIS spectroscopy) resulted in complete conversion to the ring-open isomer 3 indicating that the ring-opening process of this molecule is also catalytic.
Example 4
4.1 Synthesis of 1,2-bis(2-phenyl-3-thienyl)hexafluorocyclopent-1-ene (compound 4)
[0076]
[0077] A solution of 3-bromo-2-phenylthiophene (0.4565 g, 1.9 mmol) in anhydrous Et 2 O (25 mL) cooled to −20° C. was treated with n-BuLi (0.76 mL of a 2.5 M solution in hexane) under a nitrogen atmosphere. After stirring for 45 min, a white precipitate formed. Octafluorocyclopentene (0.119 mL, 0.95 mmol) was added via a cooled gas-tight syringe and the solution was stirred at −20° C. for 1 h. The cooling bath was removed, the reaction mixture was allowed to slowly warm to room temperature and the mixture was stirred for 16 h when it was quenched with 5% HCl (10 mL). The aqueous layer was separated and extracted with Et 2 O (2×10 mL). All organic extracts were combined, washed with H 2 O (2×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 83 mg of pure product as a white solid. Yield: 19%.
[0078] M.p. 117-118° C.; 1 H NMR (500 MHz, CD 2 Cl 2 ) δ 7.26-7.18 (m, 6H), 6.92 (m, 4H), 6.90 (d, J=5 Hz, 2H), 6.15 (d, J=5 Hz, 2H); 13 C NMR (125 MHz, CD 2 Cl 2 ) δ 145.6, 133.0, 129.0, 128.5, 128.2, 127.6, 125.6, 123.8 (8 of 13 carbons found); 19 F NMR (470 MHz, CD 2 Cl 2 ) δ-107.20 (q, J=5 Hz, 2F), −112.67 (t, J=5 Hz, 4F); FT-IR (CH 2 Cl 2 cast) 3057, 1651, 1600, 1493, 1445, 1384, 1338, 1278, 1237, 1188, 1130, 1087, 1074, 1023, 1000, 965, 941, 842, 761, 746, 711, 692, 668, cm −1 ; HRMS (EI) Calcd for M + (C 25 H 14 F 6 S 2 ): 492.0441. Found: 492.0445. Anal. Calcd for C 25 H 14 F 6 S 2 : C, 60.97; H, 2.87. Found: C, 60.94; H, 2.99.
4.2 Synthesis of the Ring-Closed Form 4′
[0079]
[0080] Compound 4 (˜5 mg) was dissolved in CH 2 Cl 2 (20 mL) and placed in a quartz glass cell. The solution was irradiated with 313 nm light for 5 min. The solvent was removed under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes:CHCl 3 , 9:1) to afford 4′ as a purple solid.
[0081] 1 H NMR (300 MHz, CD 2 Cl 2 ) δ 7.69 (dt, J=7, 2 Hz, 4H), 7.39-7.22 (m, 5H), 7.01 (d, J=6 Hz, 2H), 6.22 (d, J=6 Hz, 2H).
4.3 UV-VIS Absorption Spectroscopy of Compound 4
[0082] Upon irradiation of a CH 2 Cl 2 solution (2×10 −5 M) of 4 with 313 nm light, the colourless ring-open form 4 (λ max =251 nm) was converted to the purple ring-closed isomer 4′ (λ max =541 nm) ( FIG. 7 b ). 1 H NMR spectroscopic analysis determined that the photostationary state contained 27% of the ring-closed isomer 4′ when a CD 2 Cl 2 solution (1×10 −3 M) of 4 was irradiated with 313 nm light for 2 minutes. The ring-opening reactions of both 3′ and 4′ could be done by irradiating the solutions with light using wavelengths greater than 490 nm.
4.4 Cyclic Voltammetry of Compound 4
[0083] The cyclic voltammogram of a CH 3 CN solution (1×10 −3 M) of 4 shows an irreversible oxidation peak at 1.86 V due to the oxidation of the ring-open isomer ( FIG. 8 b ). Irradiation of the solution with 313 nm light generated the purple ring-closed isomer and the cyclic voltammogram of this solution showed a very small irreversible oxidation peak at 1.05 V which is assigned to the ring-closed isomer 4′.
4.5 Electrochemical Ring-Opening of 4′
[0084] Electrolysis of a CD 3 CN solution (1×10 −3 M) of 4′ containing 27% of the ring-closed isomer 4′ at 1.1 V for 10 minutes resulted in the decolourization of the solution and subsequent regeneration of the 1 H NMR spectrum of the ring-open isomer 4. Addition of 8 mol % of the one-electron accepting radical cation [(4-BrC 6 H 4 ) 3 N][SbCl 6 ] to a CD 2 Cl 2 solution (1×10 −5 M) of 4′ at the photostationary state (as determined by UV-VIS spectroscopy) resulted in the complete disappearance of the absorption band in the visible region of the UV-VIS absorption spectrum and regeneration of the spectrum for the ring-open 4 indicating that the ring-opening process of this molecule is also catalytic.
Example 5
5.1 Synthesis of 1,2-bis(2-methyl-5,5′-dithiophen-3-yl)perfluorocyclopent-1-ene (compound 5)
[0085] Method 1
5.1.1 Synthesis of 1,2-bis(5-bromo-2-methylthien-3-yl)-perflourocyclopent-1-ene (DTE-Br).
[0086] A solution of dichloride DTE-CL (0.500, 1.14 mmol) in anhydrous Et 2 O (40 mL) cooled to −78° C. was treated with t-BuLi (1.34 mL of a 1.7 M solution in pentane) dropwise under an argon atmosphere. After stirring for 30 min, a solution of Br 2 (0.117 mL, 2.29 mmol) in anhydrous Et 2 O (10 mL) was added dropwise and the mixture was stirred for 20 min at −78° C. The cooling bath was removed and the reaction mixture was allowed to warm to room temperature. The reaction mixture was washed with H 2 O (2×15 mL) followed by brine (15 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 0.452 g of the pure product as a colorless crystalline solid. Yield: 75%
[0087] M.p. 146-148° C.; 1 H NMR (300 MHz, CDCl 3 ) δ 6.99 (s, 2H), 1.87 (s, 6H); 13 C NMR (100 MHz, CDCl 3 ) δ 143.3, 129.1, 125.2, 110.0, 14.4 (5 of 8 carbons found); FT-IR (CH 2 Cl 2 cast) 3110, 3076, 2924, 1514, 1425, 1322, 1220, 1152, 1079, 1003, 839, 812, 785, 692 cm −1 ; LRMS (EI) Calcd for M + (C 15 H 8 Br 2 F 6 S 2 ): 524. Found: 524 (M + , [ 79 Br][ 79 Br], 52%), 526 (M + , [ 79 Br][ 81 Br], 100%), 528 (M + , [ 81 Br][ 81 Br], 58%). Anal. Calcd for C 15 H 8 Br 2 F 6 S 2 : C, 34.23; H, 1.53. Found: C, 34.07; H, 1.56.
5.1.2 Synthesis of 1,2-bis(2-methyl-5,5′-dithiophen-3-yl)perfluorocyclopent-1-ene (compound 5)
[0088] A solution of 2-bromothiophene (0.080 g, 0.50 mmol) in anhydrous Et 2 O (10 mL) was treated with magnesium turnings (0.014 g, 0.57 mmol) and heated at reflux for 45 min. The heat source was removed and the reaction mixture was allowed to cool to room temperature when it was added to a solution of dibromide DTE-Br (0.100 g, 0.20 mmol), Pd(dppf)Cl 2 (0.6 mg, 0.004 mmol) and anhydrous Et 2 O (10 mL) cooled to 0° C. dropwise via a canula. The reaction was stirred at this temperature for 1 h, then allowed to come to room temperature and stirred for 16 h when it was quenched with 5% HCl (10 mL). The aqueous layer was separated and extracted with Et 2 O (3×10 mL). All organic extracts were combined, washed with H 2 O (3×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 0.056 g of pure product as a white solid. Yield: 55%
Method 2
5.2.3 Synthesis of 4-bromo-5-methyl-[2,2′]bithienyl (BT2)
[0089] A solution of 2-bromothiophene (1.44 g, 8.8 mmol) in anhydrous Et 2 O (25 mL) was treated with magnesium turnings (0.257 g, 10.6 mmol) and heated at reflux for 45 min under a nitrogen atmosphere. The heat source was removed and the reaction mixture was allowed to cool to room temperature when it was added to a cooled (0° C.) solution of 3,5-dibromo-2-methylthiophene (2.0 g, 8.8 mmol), Pd(dppf)Cl 2 (13 mg, 0.018 mmol) and anhydrous Et 2 O (10 mL) dropwise via a canula. The reaction was stirred at this temperature for 1 h, the cooling bath was removed, the mixture was allowed to slowly come to room temperature and stirred for 16 h when it was quenched with 5% HCl (10 mL). The aqueous layer was separated and extracted with Et 2 O (2×20 mL). All organic extracts were combined, washed with H 2 O (3×20 mL), followed by brine (20 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 1.69 g of pure product as a white solid. Yield: 78%.
[0090] M.p. 36-37° C.; 1 H NMR (400 MHz, CD 2 Cl 2 ) δ 7.24 (dd, J=5, 1 Hz, 1H), 7.13 (dd, J=4, 1 Hz, 1H), 7.02 (dd, J=5, 4 Hz, 1H), 7.00 (s, 1H), 2.39 (s, 3H); 13 C NMR (100 MHz, CDCl 3 ) 136.4, 133.1, 127.8, 125.9, 124.6, 123.7, 109.5, 14.7 (8 of 9 carbons found); FT-IR; LRMS (CI) Calcd for M + (C 9 H 7 BrS 2 ): 258. Found: 261 ([M+H] + , [ 81 Br], 92%), 259 ([M+H] + , [ 79 Br], 100%). Anal. Calcd for C 9 H 7 BrS 2 : C, 41.71; H, 2.72. Found: C, 41.96; H, 2.66.
5.2.4 Synthesis of 1,2-bis(2-methyl-5,5′-dithiophen-3-yl)perfluorocyclopent-1-ene (compound 5)
[0091] A solution of 4-bromo-5-methyl-[2,2′]bithienyl BT2 (0.395 g, 1.5 mmol) in Et 2 O (20 mL) cooled to −20° C. was treated with n-BuLi (0.61 mL of a 2.5 M solution in hexane) dropwise under a nitrogen atmosphere. After stirring for 30 min at this temperature, octafluorocyclopentene (95 μL, 0.7 mmol) was added using a cooled gas-tight syringe and the solution immediately turned dark red in color. The reaction was stirred at −20° C. for 1 h, the cooling bath was removed, the solution was slowly warmed to room temperature and stirred for an additional 16 h at this temperature. The reaction was quenched with 5% HCl (10 mL), the layers were separated and the aqueous layer was extracted with Et 2 O (2×10 mL). The combined organic extracts were washed with H 2 O (2×10 mL), brine (1×10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes). The isolated product was recrystallized (hexanes) yielding 0.115 g of pure product as a white crystalline solid. Yield: 30%.
[0092] M.p. 126-127° C.; 1 H NMR (600 MHz, CD 2 Cl 2 ) δ 7.28 (dd, J=5, 1 Hz, 2H), 7.16 (dd, J=3.6, 1.2 Hz, 2H), 7.15 (s, 2H), 7.03 (dd, J=5.1, 3.6 Hz, 2H), 1.97 (s, 6H); 13 C NMR (125 MHz, CDCl 3 ) δ 140.8, 136.2, 135.5, 127.9, 125.5, 124.9, 124.1, 122.8, 14.4 (9 of 12 carbons found); FT-IR (CH 2 Cl 2 cast) 3117, 3076, 2952, 2910, 1440, 1426, 1338, 1275, 1192, 1138, 1115, 1053, 986, 837, 818, 742, 696 cm −1 ; LRMS (CI) Calcd for M + (C 23 H 14 F 6 S 4 ): 532. Found: 533 [M+H] + ; Anal. Calcd for C 23 H 14 F 6 S 4 : C, 51.87; H, 2.65. Found: C, 52.05; H, 2.59.
5.2.4 Synthesis of the Ring-Closed Form 5′
[0093]
[0094] Compound 5 (5 mg) was dissolved in CH 2 Cl 2 (50 mL) and placed in a quartz glass cell. The solution was irradiated at 365 nm for 10 min. The solvent was evaporated off under reduced pressure and the crude product purified using HPLC (hexanes) to afford the pure product 5′ as a blue powder.
[0095] 1 H NMR (300 MHz, CD 2 Cl 2 ) δ 7.51 (dd, J=5, 1 Hz, 2H), 7.31 (dd, J=4, 1 Hz, 2H), 7.11 (dd, J=5, 4 Hz, 2H), 6.54 (s, 2H), 2.16 (s, 6H).
5.3 UV-VIS Absorption Spectroscopy of Compound 5
[0096] A solution of 5 (2×10 −5 M) in CH 2 Cl 2 appears at λ max =316 nm ( FIG. 9 ). Irradiation of 5 with 365 nm light produces 5′ with an absorption band at λ max =625 nm. The photostationary state upon irradiation of a solution (1×10 −3 M) in CD 2 Cl 2 of 5 with 365 nm light is >97%. Irradiation with light greater than 490 nm resulted in the loss of colour and regeneration of the spectrum corresponding to 5.
5.4 Electrochemical Ring-Closing of Compound 5
[0097] The voltammogram of a CH 3 CN solution (1×10 −3 M) of 5 shows an irreversible oxidation peak at 1.41 V ( FIG. 10 a , top trace). The voltammogram of 5′ performed on a CH 3 CN (1×10 −3 M) solution of 5 after irradiation with 365 nm light for 6 minutes shows a clear reversible anodic wave at 0.85 V due to the oxidation of the ring-closed isomer 5′ ( FIG. 10 a , bottom trace). When the cyclic voltammetry experiment of the ring-open isomer 5 is swept through several oxidation/reduction cycles, a reversible peak appears at the same potential as that for the ring-closed isomer 5′ ( FIG. 10 a , inset) revealing that the ring-closing reaction is induced electrochemically.
Example 6
6.1 Synthesis of 1,2-bis-(2-methyl-5,2′-dithiophen-3-yl)perfluorocyclopentene (compound 6)
[0098]
[0099] A solution of 2-bromo-5-methylthiophene (0.124 g, 0.70 mmol) in anhydrous Et 2 O (10 mL) was treated with magnesium turnings (0.02 g, 0.83 mmol) and heated at reflux for 45 min under a nitrogen atmosphere. The heat source was removed and the reaction mixture was allowed to cool to room temperature when it was added to a cooled (0° C.) solution of dibromide DTE-Br (0.15 g, 0.29 mmol), Pd(dppf)Cl 2 (0.6 mg, 0.004 mmol) and anhydrous Et 2 O (10 mL) dropwise via a canula. The reaction was stirred at this temperature for 1 h, then allowed to come to room temperature and stirred for 24 h when it was quenched with 5% HCl (10 mL). The aqueous layer was separated and extracted with Et 2 O (3×10 mL). All organic extracts were combined, washed with H 2 O (3×10 mL), followed by brine (10 mL), dried (Na 2 SO 4 ) and filtered. The solvent was evaporated under reduced pressure and the crude product was purified using column chromatography through silica gel (hexanes) yielding 0.116 g of pure product as a white solid. Yield: 72%
[0100] M.p. 124-125° C.; 1 H NMR (400 MHz, CD 2 Cl 2 ) δ 7.05 (s, 2H), 6.94 (d, J=4 Hz, 2H), 6.69 (dq, J=3, 1 Hz, 2H), 2.47 (d, J=1 Hz, 6H), 1.94 (s, 6H); 13 CNMR (125 MHz, CDCl 3 ) δ 140.2, 139.7, 135.9, 133.9, 126.0, 125.4, 123.9, 122.0, 15.3, 14.4 (10 of 13 carbons found); FT-IR (microscope) 3081, 3063, 2956, 2923, 2859, 2740, 1720.1622, 1580, 1559, 1536, 1500, 1441, 1380, 1338, 1308, 1264, 1241, 1225, 1183, 1160, 1132, 1097, 1050, 987, 901, 867, 849, 839, 827, 817, 794, 747, 738, 697, 678, 662, 623 cm −1 ; HRMS (EI) Calcd for M + (C 25 H 18 F 6 S 4 ): 560.0196. Found: 560.01982. Anal. Calcd for C 25 H 18 F 6 S 4 : C, 53.56; H, 3.24. Found: C, 53.47; H, 3.26.
6.2 Synthesis of the Ring-Closed Form 6′
[0101]
[0102] Compound 6 (1 mg) was dissolved in CD 2 Cl 2 (2 mL) and placed in an NMR tube. The solution was irradiated at 365 nm for 7 min. This resulted in a photostationary state consisting of >97% of the ring-closed isomer 6′. No attempts were made to isolate 6′.
[0103] 1 H NMR (600 MHz, CD 2 Cl 2 ) δ 7.09 (d, J=5.4 Hz, 2H), 6.77 (dq, J=5.4, 1.2 Hz, 2H), 6.42 (s, 2H), 2.52 (s, 6H), 2.12 (s, 6H).
6.3 Cyclic Voltammetry of Compound 6
[0104] Compound 6 showed similar behaviour as compound 5 as described above. The voltammogram of 6 shows an irreversible oxidation peak at E ox =1.26 V ( FIG. 10 b , top trace). Irradiation of the solution with 365 nm generated the ring-closed form 6′ which shows a reversible anodic wave at E 1/2 =0.74 V ( FIG. 10 b , bottom trace).
6.4 Electrochemical Ring-Closing of Compound 6
[0105] A colourless solution of 6 was electrolyzed at 1.35 V. Immediately after the electrolysis reaction was started, a red species was generated in the solution surrounding the platinum coil working electrode. After several seconds of electrolysis, the entire solution turned deep red in colour. Although the red species produced upon electrolysis has not been characterized, we believe this to be the oxidized ring-closed form. Reduction of the solution by applying a voltage of 200-400 mV or simply opening the reaction to the atmosphere resulted in a colour change of the solution from red to blue, suggesting that the neutral ring-closed isomer was produced. The deep blue solution of 6′ which was generated electrochemically can be photochemically bleached upon exposure to greater than 490 nm light for 15 minutes. Thus compound 6 is reversibly convertible between a colourless form, a red form and a blue form. This is potentially important with respect to high-density data storage media, where the three colours can represent three digital states (0, 1, 2) at the same storage location on the medium. This way more information can be stored at a single site.
Example 7
7.1 Synthesis of 2,3-bis(3-(2-methyl-5-chlorothienyl))bicyclo[2.2.1]hept-2,5-diene (compound 7)
[0106] A solution of 2-methyl-3-bromo-5-chlorothiophene in anhydrous ether (75 mL) was treated with n-butyllithium (3.6 mL, 2.5 M in hexane, 9.0 mmol) dropwise at −78° C. under an N 2 atmosphere. The resulting yellow solution was stirred for 30 min at this temperature then it was treated with a solution of anhydrous ZnCl 2 (1.23 g, 9.00 mmol) in anhydrous ether (10 mL) in one portion via a cannula (Scheme 5, above). After stirring for an additional 30 min at −78° C., the cooling bath was removed and the reaction mixture was transferred via a cannula into a frame-dried flask containing 2,3-dibromobicyclo[2.2.1]hepta-2,5-diene (750 mg, 3.00 mmol), Pd(PPh 3 ) 4 (100 mg, 0.087 mmol) and anhydrous THF (50 mL). The resulting pale yellow solution was allowed to warm slowly to room temperature and heated at reflux for 18 h under an N 2 atmosphere. The heating source was removed, the reaction was allowed to slowly cool to room temperature and quenched with saturated NH 4 Cl (50 mL). The aqueous layer was removed and extracted with ether (3×50 mL). The combined organic layers were dried (Na 2 SO 4 ), filtered and concentrated to dryness in vacuo. The crude product was purified by column chromatography (hexanes) yielding 0.65 g of dichloride monomer 7 as a pale yellow solid. Yield: 62%.
[0107] M.p. 67-69° C.; 1 H NMR (CDCl 3 , 400 MHz) δ 6.93 (m, 2H), 6.58 (s, 2H), 3.70 (m, 2H), 2.32 (dt, J=6, 2 Hz, 1H), 2.09 (dt, J=6, 2 Hz, 1H), 1.85 (s, 6H), 13 C NMR (CDCl 3 , 100 MHz) δ 145.8, 142.9, 134.6, 132.6, 125.9, 71.6, 56.3, 14.1. FT-IR (KBr-cast) 2970, 2864, 1545, 1463, 1294, 1023, 970, 820, 709, 646, 468 cm −1 ; MS (CI isobutane) m/z=353 [M+H] + ; Anal. Calcd for C 17 H 14 Cl 2 S 2 ; C, 57.79; H, 3.99; N, 0.00. Found: C, 57.39; H, 3.84; N, 0.00.
Example 8
8.1 Synthesis of 2,3-bis(3-(2-methyl-5-carboxymethylthienyl))bicyclo[2.2.1]hept-2,5-diene (compound 8)
[0108] As shown in Scheme 5, above, a solution of dichloride monomer 7 (300 mg, 0.85 mmol) in anhydrous THF (40 mL) was treated dropwise with t-butyllithium (1.40 mL, 1.7 M in pentane, 2.40 mmol) at −78° C. until no starting material was detected by TLC. After stirring at −78° C. for 30 min, the cooling ice bath was removed and dry CO 2 gas was bubbled through the solution for 30 min. A white suspension immediately formed. The reaction mixture was concentrated to dryness in vacuo and re-suspended in acetone (40 mL). Solid K 2 CO 3 (236 mg, 1.7 mmol) was added, followed by dimethylsulfate (0.2 mL, 2.13 mmol). The reaction was heated at reflux under an N 2 atmosphere for 18 h. The heating source was removed, the reaction was allowed to slowly cool to room temperature and quenched with water (20 mL). The acetone was removed in vacuo and the remaining aqueous solution was extracted with ether (5×30 mL). The combined organic layers were washed sequentially washed with saturated NaHCO 3 (10 mL) and brine (10 mL), dried (Na 2 SO 4 ), filtered and evaporated to dryness in vacuo. The crude product was purified by column chromatography (9% EtOAc/hexane) yielding 150 mg of diester monomer 8 as a white solid. Yield: 44%.
[0109] M.p. 102-103.5° C. 1 H NMR (CDCl 3 , 400 MHz) δ 7.49 (s, 2H), 6.97 (m, 2H), 3.84 (s, 6H), 3.75 (m, 2H), 2.37 (d, J=3 Hz, 1H,), 2.12 (d, J=3 Hz, 1H), 1.86 (s, 6H); 13 C NMR (CDCl 3 , 100 MHz) δ 162.6, 146.2, 143.0, 142.1, 136.4, 134.5, 129.5, 71.8, 56.7, 52.0, 14.7; FTIR (KBr-cast) 2945, 2848, 1717, 1648, 1469, 1303, 1255, 1082, 745, 717 cm −1 . MS (CI isobutane) m/z=401 [M+H] + , 369 [M-OCH 3 ] + ; Anal. Calcd for C 21 H 20 O 4 S 2 : C, 62.98; H, 5.03; N, 0.00. Found: C, 62.64; H, 5.31; N, 0.00.
Example 9
9.1 Synthesis of 2,3-bis(4-(5,5′-dimethyl-2,2′-bithienyl))bicyclo[2.2.1]hepta-2,5-diene (compound 9)
[0110]
9.1.1 Synthesis of 4-bromo-5,5′-dimethyl-2,2′-bithienyl (BT3)
[0111] A solution of 2-bromo-5-methylthiophene (4.00 g, 22.6 mmol) in anhydrous ether (10 mL) was treated with magnesium turnings (0.577 g, 23.7 mmol) and heated at reflux for 45 min under an N 2 atmosphere. The heat source was removed and the reaction mixture was slowly allowed to cool to room temperature when it was transferred to a flame-dried addition funnel via a cannula. A solution of 3,5-dibromo-2-methylthiophene (5.49 g, 21.5 mmol) and Pd(dppf)Cl 2 (16.5 mg, 0.023 mmol) in 75 mL anhydrous ether was treated dropwise with the solution of the Grignard reagent over 30 min at 0° C. under an N 2 atmosphere using an addition funnel. The resulting solution was allowed to slowly warm to room temperature and stirred for 72 h under an N 2 atmosphere, when it was quenched with saturated NH 4 Cl (50 mL). The aqueous layer was separated and extracted with ether (3×75 mL). The combined organic layers were dried over Na 2 SO 4 , filtered and evaporated to dryness in vacuo. The crude product was purified by flash chromatography (hexanes) yielding 4.32 g of pure BT3 as a white solid. Yield: 74%.
[0112] M.p. 80-81° C.; 1 H NMR (CDCl 3 , 400 MHz) δ 6.89 (m, 2H), 6.64 (m, 1H), 2.47 (s, 3H), 2.37 (s, 3H); 13 C NMR (CDCl 3 , 100 MHz) δ 139.5, 134.9, 132.5, 125.9, 125.2, 123.5, 109.3, 15.3, 14.7 (9 of 10 carbons found). MS (CI isobutane) m/z=273 [M+H] + .
9.1.2 Synthesis of 2,3-bis(4-(5,5′-dimethyl-2,2′-bithienyl))bicyclo[2.2.1]hepta-2,5-diene (compound 9)
[0113] A solution of 4-bromo-5,5′-dimethyl-2,2′-bithienyl BT3 (1.50 g, 5.49 mmol) in anhydrous ether was treated dropwise with n-butyllithium (2.2 mL, 2.5 M in hexane, 5.5 mmol) at −40° C. under an N 2 atmosphere. The resulting yellow solution was stirred for 30 min at this temperature, then it was treated with a solution of anhydrous ZnCl 2 (0.75 g, 5.5 mmol) in anhydrous ether (10 mL) in one portion via a cannula. After stirring for an additional 30 min at −40° C., the cooling bath was removed and the reaction mixture was transferred via a cannula into a flame-dried flask containing 2,3-dibromo[2.2.1]hepta-2,5-diene (0.500 g, 2.00 mmol), Pd(PPh 3 ) 4 (46 mg, 0.040 mmol) and anhydrous THF (50 mL). The resulting solution was allowed to slowly warm to room temperature and heated at reflux for 18 h under an N 2 atmosphere. The heat source was removed, the reaction was allowed to slowly cool to room temperature and quenched with saturated NH 4 Cl (50 mL). The aqueous layer was removed and extracted with ether (3×75 mL). The combined organic layers were dried over Na 2 SO 4 , filtered and evaporated to dryness in vacuo. The crude product was purified by flash chromatography (hexanes) and crystallized from 30% hexanes in ether yielding 500 mg of monomer 9 as white platelets. Yield: 54%.
[0114] M.p. 129-130° C.; 1 H NMR (CD 2 Cl 2 , 400 MHz) δ 6.98 (t, J=6 Hz, 2H), 6.83 (d, J=4 Hz, 2H), 6.61 (m, 2H), 3.77 (m, 2H), 2.43 (d, J=1 Hz, 6H), 2.36 (dt, J=6, 2 Hz, 1H), 2.09 (dt, J=6, 2 Hz, 1H), 1.89 (s, 6H); 13 C NMR (CDCl 3 , 100 MHz) δ 145.7, 143.0, 138.5, 136.0, 135.3, 133.7, 132.7, 125.7, 122.9, 122.8, 71.5, 56.4, 15.3, 14.2.
Example 10
10.1 General Polymerization Procedure
[0115] A solution of bis(tricyclohexylphosphine)benzylidene ruthenium(IV)dichloride (0.003-0.01 mmol) dissolved in dry deoxygenated THF (2 mL) was added through a cannula into a THF solution of the appropriate monomer (0.2-0.5 mmol) as shown in Scheme 5 above. The final monomer concentrations were 0.05 M. After stirring at room temperature for 18 h under a N 2 atmosphere, excess ethyl vinyl ether was added and the resulting solutions were stirred while exposed to the atmosphere for 30 min. The crude reaction mixtures were evaporated to dryness in vacuo. To isolate the polymers in high purity the solid residues were re-dissolved in THF (2 mL), triturated with cold methanol or ether and the precipitate collected by vacuum filtration.
10.2 Dichloride Polymer (Compound 10)
[0116] Dichloride monomer 7 (137 mg, 0.37 mmol) was polymerized with 0.02 molar equivalents of bis(tricyclohexylphosphine)benzylidene ruthenium(IV)dichloride (6.1 mg, 0.007 mmol) to afford 105 mg of polymer 10 as an off-white solid. Yield: 80%.
[0117] 1 H NMR (CDCl 3 , 400 MHz) δ 6.5 (br s), 5.4 (br s), 3.7 (br s), 3.5 (br s), 2.5 (br s), 1.8-1.6 (m).
Example 11
11.1 Diester Polymer (Compound 11)
[0118] Diester monomer 8 (150 mg, 0.38 mmol) was polymerized with 0.02 molar equivalents of bis(tricyclohexylphosphine)benzylidene ruthenium(IV)dichloride (6.2 mg, 0.008 mmol) to afford 92 mg of polymer 11 as an off-white solid. Yield: 60%.
[0119] 1 H NMR (CDCl 3 , 400 MHz) δ 5.3-5.4 (m), 3.5 (br s), 3.8 (br s), 2.5 (br s), 1.9-1.7 (m).
Example 12
12.1 Dicarboxylic Acid Polymer (Compound 12)
[0120] A solution of diester polymer 11 (31 mg) in deoxygenated THF (3 mL) was treated with deoxygenated water (1.5 mL), followed by an aqueous KOH solution (0.3 mL, IM). The resulting solution was heated at reflux under an N 2 atmosphere for 5 h, the heat source was removed, the reaction was allowed to cool slowly to room temperature and stirred there for 18 h. The crude reaction mixture was concentrated to 1 mL, and acidified with 3M HCl (3 drops). The resulting precipitate was collected by vacuum filtration, washed sequentially with cold water (3 mL), Et 2 O (3 mL) and CHCl 3 (3 mL) and dried in vacuo yielding 25 mg of dicarboxylate polymer 12 as an off-white solid. Yield: 83%.
[0121] 1 H NMR (CH 3 OD, 400 MHz) δ 7.3 (br s), 5.4 (br s), 4.2-3.4 (m), 2.5 (br s), 1.8 (br s).
[0122] Representative UV spectra from typical photoisomerization studies are illustrated in FIG. 11 in respect of monomer 8 and polymers 11 and 12. All solutions were prepared at 2×10 5 M in the active photochromic component. Polymer films were spin-coated onto 1 cm×2 cm quartz substrates as CHCl 3 solutions using a Laurell WS400A-6NPP/Lite spin-coater.
[0123] Table 3 below shows the results of GPC analysis on selected compounds described above. With respect to the polymers reported in Table 1. The glass transition temperatures and melting temperatures of polymers 10 and 11, measured by differential scanning calorimetry (DSC), are also included. Themogravimetic analysis of polymers 10 and 11 indicated they are stable at high temperature.
[0124] The absorption spectra of THF solutions ( FIG. 11 and Table 3) of polymers 10 and 11 shows that in each case the λ max values of the ring-closed form of the polymers are red-shifted when compared to the corresponding monomers 7 and 8 respectively. This effect can be attributed to the relief of ring-strain in the polymer, a direct result of the ROMP process.
[0125] The results of the photoinduced isomerization studies, carried out by irradiating the THF solutions at 254 nm or 313 nm with a hand-held UV lamp, are shown in FIG. 11 . Within the first 10 seconds of irradiation, absorption bands appear between 500 and 600 nm as the photochromic monomers and polymers are converted from their colorless ring-open to their colored-closed forms.
TABLE 3 Monomer and Polymer Characterization PDI T g T m λ max /nm (ε × 10 −4 L mol −1 cm −1 ) compd M w M n (M w /M n ) (° C.) (° C.) ring-open form ring-closed form a 10 19200 15000 1.28 84 164 237 (3.03) 455 (1.33) 7 — — — — — 226 (2.22) 422 (0.65) 11 22100 15400 1.44 80 166 252 (3.15) 556 (1.35) 8 — — — — — 244 (2.97) 504 (1.20) 12 b — — — — — 248 (2.31) 527 (1.25) a Photostationary states obtained by irradiating (254 nm for 7, 8, and 10 and 313 nm for 11 and 12) THF solutions of the ring-open forms for 30 seconds. b In aqueous phosphate buffer (pH 7).
[0126] After 120 seconds of irradiation at the concentration used, the increases in the visible absorption bands level off. The resulting colored solutions can be decolorized by irradiating them with broad-band light greater than 490 nm (434 nm for 7 and 10) resulting in the complete disappearance of absorption bands in the visible region. However, long irradiation times result in a small degree of photodegradation and the absorption spectra corresponding to the ring-open forms cannot be fully regenerated. This result is not surprising as we have reported how some non-fluorinated dithienylalkene derivatives are substantially less photo-fatigue resistant than their fluorinated counterparts. FIG. 11 also shows the photochromic behavior of hydrophilic polymer 12 in aqueous solution (phosphate buffer, pH 7, 25° C.). This polymer can also be reversibly colorized and decolorized.
[0127] Polymers 10 and 11 retain their photochromic behavior when spin-coated from CHCl 3 solutions onto quartz substrates ( FIG. 11 ). Irradiation of the films with UV light (254 nm for 10 and 313 nm for 11) resulting in the immediate change in color indicating that the photochromic properties of the polymers were conserved in the processed state The changes in the UV-Vis absorption spectrum of each polymer were similar to those obtained in solution, with the exception that slightly longer irradiation times were required to reach the photostationary states (290 seconds compared to 120 seconds for polymer 11, for example). The percent mass of the active photochromic component in our original side-chain polymers ranges from 60-68%. The new generation main-chain polymer ranges from 93%. This is due to the ROMP reaction of the strained olefin producing the requisite cyclopentene backbone that has been shown to be so versatile.
Example 13
13.1 Dithiophene Polymer 13
[0128] Monomer 9 (99 mg, 0.21 mmol) was polymerized as shown in Scheme 5 with 0.02 molar equivalents of bis(tricyclohexylphosphine)benzylidene ruthenium(IV)dichloride (3.4 mg, 0.004 mmol) to afford 40 mg of polymer 13 as an off-white solid (40%). 1 H NMR (CDCl 3 , 400 MHz) δ 6.8-6.5 (m), 5.4 (br s), 3.8 (br s), 3.5 (br s), 2.5-2.3 (m), 1.8-1.6 (m).
[0129] It is expected polymer 13 will be electrochromic based on its structural similarity to compound 6 described above.
[0130] Polymer 12 is hydrophilic. Polymers 10, 11, and 13 are lipophilic.
[0131] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. | This invention relates to novel photochromic and electrochromic monomers and polymers based on 1,2-dithienylcyclopentene derivatives and method of using and synthesizing same. The compounds are reversibly interconvertible between different isomeric forms under suitable photochromic or electrochromic conditions. The electrochromic conversion may be catalytic. The application also relates to ultra-high density homopolymers prepared using ring-opening methathesis polymerization (ROMP) where the central ring of the 1,2-bis(3-thienyl)-cyclopentene is incorporated directly into the polymer backbone. The monomer units may be readily functionalized to enable the synthesis of polymers with diverse structural and electronic properties. The compounds have many potential applications including high-density optical information storage systems, photoregulated molecular switches, reversible holographic systems, ophthalmic lenses, actinometry and molecular sensors, photochromic inks, paints and fibers and optoelectronic systems such as optical waveguides, Bragg reflectors and dielectric mirrors. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to food storage containers and specifically to a novel container cover with integrated compartments for storing separate food items.
[0003] 2. Related Art
[0004] Traditionally, food items such as take out, packed lunch, frozen dinners, and the like have been stored in individual containers for convenient and spill free transport. For example, some known containers for food items include bags, foil, wax paper, plastic or other rigid or semi-rigid containers. These traditional containers may be well suited for storing and transporting food items. However, they are not well suited for and generally not designed to preserve the quality, taste, freshness of certain mixed food items stored therein. This is especially so for food items with sauces, dressing, and the like.
[0005] For example, salad with dressing cannot be stored in a traditional container for more than a short period of time because the dressing will quickly cause the salad to lose its crispness. Likewise, cereal with milk cannot be stored in a traditional container because the cereal will rapidly become soggy. In other situations, it may be desirable to keep hot and cold food items or dry and liquid food items separate until the items are ready to be eaten.
[0006] It is known that this may be accomplished by utilizing separate and distinct containers to store food items. At the time of consumption a person may then open each separate container and combine the food items. In this manner, the taste, freshness, and quality are preserved. However, this requires separate individual containers which wastes material and is inconvenient. In addition, when traveling or taking out food from a restaurant, one of the multiple containers may be left behind or forgotten thereby leaving a food item without its associated sauce, dressing, or the like. In this case, a person may decide the food item is not edible and the food item may be wasted or a return trip is required.
[0007] Thus, what is disclosed herein is a novel container cover with integrated compartments for storing separate food items.
SUMMARY OF THE INVENTION
[0008] A container cover for storing and transporting one or more food items is provided herein. The container cover may be used to store food items such that they remain separated until use. The container cover allows separate food items to be transported easily without the requirement of multiple individual containers.
[0009] In one embodiment, the container cover comprises a body configured to cover a container, and one or more compartments extending downward from the body. The compartments may comprise an opening to allow one or more food items to be placed within the one or more compartments, and a penetrable portion below the opening configured to release a food item into the container. A cap configured to cover the opening of the compartments may be provided as well. It is noted that in some embodiments the container cover may comprise a rim around its planar body configured to fit on the container.
[0010] One or more related food items complimentary to a food item in the container may be provided in the compartments of the container cover. It is contemplated that the related food items are the same type of food item having different flavors. Of course, unrelated food items may be stored with the container cover as well. In fact, it is also contemplated that any type of food item may be stored with the container cover.
[0011] The planar body may be configured in various ways. In one embodiment, the planar body may be removed from the container and reconnected to the container. The planar body may be configured to form a friction fit with the container.
[0012] The compartments may be configured in various ways as well. For example, the one or more compartments may comprise a releasable portion and a hinge whereby the releasable portion is attached by the hinge. In addition, the penetrable portion of the one or more compartments may comprise a puncturable material. Further, the penetrable portion of the one or more compartments may comprise at least one score line.
[0013] In another embodiment, the container cover comprises a container having a mouth and storing a first food item, a planar body attached to the container covering the mouth, a plurality of compartments extending from the planar body, and at least one cap attached to the planar body configured to seal the one or more compartments. The one or more compartments may be configured to release at least one second food item into the container when opened.
[0014] The compartments may be configured to release food items in various ways. For example, the compartments may comprise at least one puncturable portion which allow the compartments to be punctured. The compartments may also or alternatively comprise at least one score line. Further, the compartments may comprise a releasable portion and a hinge whereby the releasable portion is attached by the hinge.
[0015] A method for consuming a plurality of food items using a container cover is also provided herein. In one embodiment, the method comprises placing one or more food items in a container, covering the container with a container cover comprising one or more compartments, placing one or more other food items in the one or more compartments through an opening of the one or more compartments, and covering the opening of the one or more compartments with one or more caps. It is contemplated that the one or more other food items may be complementary to the one or more food items in the container and are placed separately in the one or more compartments.
[0016] The food items may then be subsequently eaten. For instance, in one embodiment the method includes removing the one or more caps to access the one or more compartments, opening the one or more compartments to release the one or more other food items into the container, removing the container cover, and eating the one or more food items and the one or more other food items from the container.
[0017] If it is desired that the food items be mixed, the one or more caps may be reconnected to cover the one or more compartments and the one or more food items and the one or more other food items may be agitated in the container to mix the one or more food items and the one or more other food items together.
[0018] According to the method, the compartments may be opened in various ways. For example, opening the one or more compartments may comprise puncturing the one or more compartments with an implement. Also, opening the one or more compartments may comprise tearing the one or more compartments along one or more score lines. Furthermore, opening the one or more compartments may comprise pushing open a releasable portion of the one or more compartments.
[0019] Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
[0021] FIG. 1 is an exploded perspective view of an exemplary container cover according to the invention;
[0022] FIGS. 2A-2B are top views of exemplary container covers having various compartments according to the invention;
[0023] FIGS. 3A-3C are cross section side views of exemplary container covers according to the invention;
[0024] FIGS. 4A-4C are cross section side views of exemplary compartments according to the invention; and
[0025] FIGS. 5A-5C are cross section side views illustrating an exemplary container cover in use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In the following description, numerous specific details are set forth in order to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention.
[0027] The container cover disclosed herein is generally configured to securely store one or more food items in one or more separate compartments. The container cover may also be configured to cover an opening or mouth of an existing container thus providing a lid for the container. In this manner, the container cover stores one or more food items in its separate compartments while sealing an opening of a container. It is contemplated that the container cover may be used with any container, now known or later developed, which has an opening that may be covered or sealed by the container cover, such as but not limited to, bowls, cups, saucers, plates, pots, pans, TUPPERWARE® (trademark of Tupperware Brands Corporation), and the like. This is because the container cover may comprise a rim and/or have a shape which allows it to cover or seal a variety of containers, as will be described further below.
[0028] Generally, a food item is any edible material, flavoring, ingredient, or the like. Though described herein with specific examples of food items, it is noted that all manner of food items and combinations thereof may be stored by the container cover. In addition, it is contemplated that, in one or more embodiments, the container cover may be used with related food items such as a meal and its condiments; different courses of the same meal; sauces, flavorings, or seasonings for a meal; or a combination thereof. The related food items will typically be food items that are complementary to one another in that they provide a better or more desirable taste to a user. It is also noted that food items in various states, such as frozen, raw, cooked, steamed, cold, warm, or hot, may be stored by the container cover.
[0029] The container cover provides many advantages. As stated, the container cover securely stores one or more food items in addition to securing food items in a container. The container cover may comprise one or more compartments and thus the food items may be stored separate from one another and separate from any food items in a container. This is advantageous in that the one or more food items can remain separate until a user decides to mix or eat the food items. For instance, dry items may remain separate from wet items, hot items separate from cold items, differently flavored items may remain separate, or a combination thereof. In this manner, the quality, crispness, freshness, and taste of one or more food items is preserved.
[0030] In the case of a salad for example, the dressing, croutons, tomatoes, etc. . . . may be stored separately while the lettuce is stored in the container. The container cover, in this embodiment, would provide separate compartments for the dressing, croutons, tomatoes, etc. . . . and provide a lid to secure the lettuce in the container. In this manner, the crispness of the lettuce and croutons are preserved and the user may enjoy a fresh salad at his or her convenience.
[0031] Another advantage which will be discussed below is that the container cover may include one or more compartments which a user may puncture or otherwise open to release the food items stored therein. The one or more compartments are beneficial in that the user may open a compartment to mix one or more food items together prior to eating them. To illustrate, in the above example, the dressing compartment may be opened so that the dressing may be mixed with the lettuce.
[0032] The one or more compartments are also beneficial in that one or more separate food items may be stored by a single container cover. With traditional containers, food items, even when they are intended to be eaten together, are stored in separate containers. This is undesirable because it is inconvenient to carry multiple individual containers. In addition, the individual containers may be forgotten or otherwise become separated, making the food items inedible or at least undesirable. For example, ketchup or other sauce for french fries may be forgotten or lost making the fries less desirable to some. The container cover herein prevents such a situation by storing one or more separate food items within its attached compartments. In this manner, individual compartments and thus the food items therein cannot be forgotten or lost.
[0033] It is contemplated that the container cover may be resistant to hot and cold temperatures in one or more embodiments. In this manner, the container cover may be microwave safe, freezer safe, or even safe to use over the stove. This is yet another advantage in that the container cover may be used to prepare, such as by heating up, one or more food items for consumption without first removing the food items.
[0034] The container cover will now be described according to the figures. FIG. 1 is an exploded perspective view illustrating an exemplary container cover 108 , a cap 112 , and a container 104 . As can be seen, the container cover 108 is configured to cover the container's 104 opening or mouth 132 and store one or more food items in one or more compartments 116 . As stated, the compartments 116 may be used to store various food items. It is contemplated that the compartments 116 may also be used to store non-food items such as but not limited to one or more napkins, straws, utensils, and the like.
[0035] In one or more embodiments, the container cover 108 may comprise a body 120 . In general, the body 120 supports the compartments 116 of the container cover. The compartments 116 may be integrally formed into the body 120 or may be attached to the body in one or more embodiments. The cup 112 may be ridged plastic or paper, or flexible plastic as foil.
[0036] The body 120 may be a planer structure and may be sufficiently rigid to support the weight of the compartments 116 and any food items within the compartments. It is contemplated that the body 120 may be a non-rigid or flexible material as well. In these embodiments, the body 120 may be tensioned across the mouth 132 of a container 104 such that the body, though flexible, can support one or more compartments 116 and their food items. It is contemplated that the body 120 may be formed from various materials including but not limited to plastic, metal, and paper.
[0037] The container cover 108 may also comprise a rim 124 in one or more embodiments. In general, the rim 124 allows the container cover 108 to attach to a container 104 . In one embodiment, the rim 124 is sized and shaped to form a friction fit with a container 104 . For example, the rim 124 may form a friction fit similar to that of known lids such as TUPPERWARE® lids. In another embodiment, the rim 124 may include one or more threads which conform to threads of a container 104 . In this manner, the container cover 108 may be attached to a container 104 by screwing the container cover onto the container. It is contemplated that the rim 124 may also be used to reinforce the structure or rigidity of the container cover 108 in one or more embodiments. In one or more embodiments, the rim 124 allows the container cover 108 to be reusable, such as described below, by allowing the container cover to be removed from and then reconnected on various containers.
[0038] It is noted that a rim 124 may not be provided in some embodiments because the container cover 108 may be directly attached to a container 104 . An example of this is shown in FIG. 3A . For example, a container cover 108 may be attached by one or more adhesives, welds, or other fasteners to a container 104 such that the container cover covers the container's mouth 132 . In one or more embodiments, the body 120 of the container cover 108 , or a portion thereof, may be adhered, welded, or otherwise attached to a container 104 .
[0039] The compartments 116 may be configured in various ways. In general, a compartment 116 will comprise a structure having sides and a bottom into which one or more food (or other) items may be placed. A compartment 116 may be a variety of shapes. For example, the compartments 116 of FIG. 1 are bowl-like shapes. It will be understood that a compartment 116 may be configured in any shape capable of storing a food item, such as but not limited to those shown in FIG. 2A-2B .
[0040] FIGS. 2A-2B are top views of exemplary container covers 108 having compartments 116 in a variety of shapes. As can be seen, the compartments 116 may be shaped and sized to store various quantities and types of food items. It is contemplated that, in one or more embodiments, a compartment 116 may be configured such that its shape conforms to the food (or other) item to be stored therein. It is also contemplated that one or more compartments 116 of any various shapes and sizes may be provided on a single container cover 108 such as shown in FIGS. 2A-2B . FIGS. 4A-4C , discussed in greater detail below, illustrate embodiments with rounded and rectangular cross sections. Of course, cross sections of other shapes, including shapes that conform to food or other items, may be used as well.
[0041] In one or more embodiments, the compartments 116 are water or air tight to prevent leakage of liquid food items, to preserve the freshness of one or more items, or both. In other embodiments, the compartments 116 may include one or more holes to allow ventilation for certain types of food items. It will be understood that a compartment 116 may be formed from various materials such as but not limited to plastic, metal, paper, or a combination thereof. It is contemplated that a compartment 116 may be formed from food safe materials and that the material chosen to form a compartment may be selected based on one or more characteristics of the food item(s) to be stored. For instance, plastic or aluminum foil may be selected for a compartment 116 used to store liquid food items while wax paper or other paper may be selected for dry food items. Any combination is contemplated.
[0042] As shown in FIG. 1 , each compartment 116 may comprise an opening 128 which allows food items to be placed in a compartment. To prevent food items from leaking or falling out of a compartment's 116 opening 128 , a cap 112 may be provided to cover the opening of one or more compartments. A cap 112 may be configured to cover a plurality of openings 128 . For instance, the cap 112 of FIG. 1 is large enough to cover the openings 128 of all the compartments 116 when placed over the container cover 108 . It is noted, that a cap 112 may also be configured to cover a single opening 128 . For example, a cap 112 may be a similar size and shape as a compartment's 116 opening 128 . In one or more embodiments, a plurality of caps 112 may be provided to cover one or more compartments 116 of a single container cover 108 . A cap 112 may be formed from any material capable of securing a food item within a compartment 116 such as the materials used to form a compartment. It is noted that by covering an opening, a cap may also seal the opening such that food items cannot leak, spill, or otherwise come out of the opening.
[0043] A cap 112 may attach to a container cover 108 in various ways. In one embodiment, such as the embodiment of FIG. 3A , a cap 112 may be attached by one or more adhesives, welds, or both. The cap 112 may also be taped to a container cover 108 . In these embodiments, the cap 112 may be a planar sheet adhered, welded, or taped to a container cover 108 . The cap 112 may generally conform to the size and shape of the container cover 108 to cover all openings 128 of a container cover, or may be sized and shaped to cover one or more individual openings. To illustrate, the cap 112 of FIG. 1 has a similar shape and size to its associated container cover 108 thus allowing it to cover all the openings 128 of the cover.
[0044] In another embodiment, the cap 112 may be attached by friction such as by a threaded connector or a snap or other friction fit such as shown in FIG. 3B . In these embodiments, the cap 112 may be a planar structure having a lip 304 where the lip has features allowing the cap 112 to frictionally attach to a container cover 108 . For example, the lip 304 may include threads which conform to threads of a container cover 108 or an opening. The lip 304 may alternatively provide a snap or other friction fit similar to known removable lids such as TUPPERWARE® lids. In one embodiment, like the embodiment of FIG. 3B , the lip 304 may be configured to provide a snap or other friction fit to the rim 124 of a container cover 108 . The center area of the cap 112 may have raised portions that correspond to the openings 116 to seal the openings.
[0045] Various combinations of caps 112 may be used with a container cover 108 . For instance, in one embodiment, one or more caps 112 are provided to seal the openings of the compartments 116 while an additional cap is provided to cover the container cover 108 . It is contemplated that the additional cap 112 may be a removable and reconnectable cap while the other caps may be planar sheets that may only be removed to access food items within the compartments 116 . In this manner, the openings of the compartments are covered by at least two caps 112 . This is illustrated in FIG. 3C which shows caps 308 covering the openings of the compartments 116 and an additional cap 312 configured to cover the container cover 108 . The additional cap 312 allows the container to be covered even after one or more of the other caps 308 have been removed or even punctured or opened because the additional cap may be reconnectable in one or more embodiments.
[0046] It is contemplated that a cap 112 may comprise one or more gaskets in some embodiments. The gaskets may conform to the openings of the one or more compartments 116 to allow the cap 112 to better cover the compartments. The gaskets may be formed from flexible materials such as rubber, plastic, silicon, or the like to allow the gaskets to form a tight seal around the opening of a compartment. It is also contemplated that the cap 112 may be configured to be removed from and reconnected to a container in one or more embodiments. For example, the cap 112 may be attached by resilient adhesives or a friction fit which allow the cap 112 to be reconnected the container cover after it has been removed.
[0047] Once sealed into a compartment 116 by a cap 112 , the food items may be stored for future release by a user. Typically, the food items will be released by puncturing or otherwise opening a compartment 116 . As will be described further below, compartments 116 may be configured to facilitate their opening by a user in various ways. In another embodiment, the compartment 116 may comprise portions that may be punctured, removed such as a removable cup, or opened. For example, a compartment 116 or a portion thereof may be formed from penetrable material that can be torn, cut, punctured, or pierced to release a food item.
[0048] A compartment 116 may also include perforations, creases, or one or more thinner sections which allow a portion of the compartment to be opened. For example, a compartment 116 may be opened by puncturing, tearing, or removing a portion of the compartment. In some embodiments a compartment 116 may not be closable once it is opened such as where the compartment is opened by puncturing or tearing. In these embodiments, the container cover 108 may be configured for a single use (i.e. be disposable). It is noted that a single use container cover 108 is well suited for fast food or take out because both the container 104 and container cover may be thrown away or recycled after use.
[0049] Of course, the container cover 108 may be configured for more than a single use (i.e. be reusable) in one or more embodiments. As will be described below, these embodiments will typically include compartments 116 that may be repeatedly opened and closed to allow for multiple uses. It will be understood that single use and multiple use container covers 108 may be interchangeably used with both disposable and non-disposable containers 104 . Typically, but not always, reusable embodiments of the container cover 108 will be formed from materials that can be cleaned for subsequent uses.
[0050] FIGS. 4A-4C are cross section side views of exemplary compartments 116 having score lines 404 which allow the compartments to be more easily opened. The score lines 404 may be perforations, creases, or thinner/weaker sections of the compartment 116 . It is noted that perforations may not be desired in embodiments where a food item, such as a liquid food item, would be able to escape through the perforations. Applying a force directly or indirectly to the score lines 404 may cause a releasable portion 408 of a compartment 116 to at least partially detach from the remainder of the compartment. In this way, the food items inside the compartment 116 may be released.
[0051] For example, in the embodiments of FIGS. 4A-4B , a user may apply a force to the releasable portion 408 , such as with a utensil, blade, or other implement, to at least partially detach the releasable portion from the remainder of the compartment 116 . As will be described further below, the utensil or other implement may be inserted through the compartment's 116 opening 128 to reach the releasable portion 408 . Of course, the user may puncture, tear, cut, or otherwise open the compartment 116 in areas besides the releasable portion 408 . It is noted that one or more score lines 404 may be provided in a single compartment 116 to the compartment to be easily opened. In addition, a score line 404 may extend a portion or the entire perimeter or circumference of a compartment 116 in one or more embodiments.
[0052] In multiple use embodiments, such as the embodiment of FIG. 4C , a compartment 116 may include a releasable portion 408 which may be opened and closed multiple times. In one embodiment, the releasable portion 408 may comprise a hinge 416 which allows the releasable portion to open and close. It is noted that the hinge 416 may be any structure which allows the releasable portion 408 to open and close while preventing the releasable portion from becoming detached from the container cover 108 . For example, the hinge 416 may comprise one or more sections of flexible plastic or the like. The hinge 416 may also prevent the releasable portion 408 from contacting or falling into food items when a compartment is opened. Though beneficial for the above reasons, a hinge 416 is not required in all embodiments.
[0053] In one embodiment, such as a reusable embodiment, the releasable portion 408 includes or forms one or more seals 420 which allow the releasable portion to attach to the remainder of the compartment 116 . The seal 420 may also seal the releasable portion 408 to the remainder of the compartment 116 to prevent food items from leaking out. It is contemplated that the seal 420 may be broken and then resealed. The seal 420 may comprise a portion of the releasable portion 408 configured to frictionally fit the remainder of the compartment 116 . For example, the releasable portion may have an edge like that of a removable lid, such as like that of a TUPPERWARE® or other lid.
[0054] One advantage of the container cover 108 and its compartments 116 is that food items are cleanly released into the container 104 . With traditional containers, a user must first open the separate container, and carefully pour food items prior to mixing them. The configuration of the compartments 116 ensures that food items only release into the container 104 . It is noted that in some embodiments the user may remove some of a food item prior to releasing it into the container 104 . In this manner, only the desired amount of a food item is released. For example, if only a small amount of dressing is desired the user may remove some of the dressing from the top of a compartment and then release the remaining dressing into the container 104 below.
[0055] Another advantage of the container cover 108 and its compartments 116 is that the user may be provided a choice of which food items to release and which to leave in their compartments. For example, a salad may be provided with multiple dressings in separate compartments 116 and the user may choose which dressing or dressings to use with his or her salad.
[0056] Referring back to FIG. 1 , it can be seen from the above that the container cover 108 may be used to secure one or more food items within a container 104 by covering a mouth 132 of the container. The container cover 108 also stores one or more food items separately within one or more compartments 116 . The compartments 116 may then be sealed by one or more caps 112 to prevent food items from falling or leaking out of the compartments. In this manner, the food items in the container 104 and the one or more compartments 116 can be stored in a single food storage apparatus comprising a container cover 108 , a container 104 , and a cap 112 . The food items may then be transported together while remaining stored separately the one or more compartments 116 .
[0057] Operation of the container cover 108 will now be described with regard to FIGS. 5A-5C . FIG. 5A illustrates an exemplary container cover 108 with two compartments 116 sealed by a cap 112 . The container cover 108 is attached to a container 104 . A first food item 504 is stored in the container 104 while a second food item 508 and a third food item 512 are stored in separate compartments 116 of the container cover 108 . The terms first, second, and third are used herein to give a name to the food items to aid in the description that follows. Thus, the first, second, and third food items may be the same or different types of food items and there may be multiple first, second, and third food items in one or more embodiments.
[0058] The food items, when provided to a user, may already be secured in the container 104 and compartments 116 by a container cover 108 and cap 112 . For example, if used in a take out or to go setting, a restaurant may place and secure one or more food items into a container 104 and one or more compartments 116 . Similarly, if the container cover 108 is used for frozen foods, the food items may be placed, secured, and then frozen for later consumption by a user. It is noted that the user may also place and secure food items into a container 104 , one or more compartments 116 , or both to store the food items in some embodiments.
[0059] When a user is ready to eat, he or she may release the food items in the compartments 116 and consume them with food items in the container 104 . FIG. 5B illustrates the release of food items according to one embodiment. As shown, the third food item 512 has been released by the user opening one of the compartments 116 with an implement 516 such as eating wear. As described above, the implement 516 may be used to apply a force which punctures, tears, or otherwise opens a compartment 116 . In FIG. 5B , the user has forced the implement through a portion of the compartment 116 thus releasing the third food item 512 into the container 104 below. The second food item 508 has been released into the container 104 as well. As can be seen, the first food item 504 , second food item 508 , and third food item 512 are now combined in the container 104 . The container cover 108 may now be removed to allow the user unhindered access to the food items. The user may then stir, mix, or just consume the food items.
[0060] In some embodiments, such as the embodiment of FIG. 5B , a cap 112 may be removed prior to releasing food items from their compartments 116 . The user may then have access to the compartments 116 . As stated above, the user may then release the food items from their compartments 116 . In one embodiment, once the cap 112 is removed the user may push an implement into the bottom or other area of the compartment 116 until the compartment is punctured or otherwise opened, releasing its food items into the container 104 below. In another embodiment, a cap 112 may be punctured rather than removed. For example, the user may puncture the cap 112 near or at the opening of a compartment. The user may then access and/or puncture the compartment 116 through the punctured area of the cap 112 . In one embodiment, a user may push an implement through the cap 112 and then into a compartment 116 until the compartment is punctured.
[0061] The cap 112 may be reconnected, such as shown in FIG. 5C to allow the food items to be tossed or mixed within the container 104 . For example, with a salad, the cap 112 may be reconnected to cover the open compartments 116 and the container's mouth 132 . Then the salad may be mixed by tossing or shaking it within the container 104 . In this manner, any salad ingredients such as dressing or croutons are mixed into the salad quickly and easily. Of course, other food items may be mixed in a similar manner once the cap 112 is reconnected. It is noted that, if desired, the container cover 108 may be removed prior to reconnecting the cap 112 to prevent and food items from getting caught in the open compartments 116 .
[0062] It is noted that once the cap 112 is removed a user may have access to the food items within the container cover's 108 compartments 116 , and that the user may immediately consume these food items if desired. For example, one or more of the compartments 116 may contain an appetizer which the user may consume prior to consuming the food items stored in the container 104 . This illustrates another benefit of the container cover 104 . Namely, that an entire meal may be stored using the container cover 104 . For example, one or more compartments 116 may contain an appetizer, while one or more other compartments contain portions or sauces of the main course stored in the container. Dessert may also be stored in one or more of the compartments 116 . In this manner, an entire meal may be easily transported.
[0063] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. In addition, the various features, elements, and embodiments described herein may be claimed or combined in any combination or arrangement. | The container cover and method of consuming food items allows a plurality of food items to be stored, transported, and consumed in a convenient package. The container cover secures food items in a container by covering an opening of the container while providing one or more compartments to store other food items. The compartments may comprise an opening to allow food items to be placed within the compartments. The compartments can be opened such that the food items stored therein are released into the container with little or no risk of spillage. The compartments may be opened in various ways such as by puncturing, tearing, or pushing open a portion of the compartments. A cap may be used to cover the opening of one or more compartments. | 1 |
This is a continuation of application Ser. No. 07/731,784, filed Jul. 18, 1991, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an image pickup apparatus, particularly to the image pickup apparatus with zooming function.
FIG. 1 shows a known image pickup apparatus capable of autofocusing with zooming function, which has an optical system 10 provided with a front lens section 1, a zoom lens section 2 and an imaging lens section 3.
A light beam depicted by an arrow A from an object is incident, via the optical system 10, to an image pickup device (such as a charge coupled device) 4 which converts the light beam to an electric signal. The signal is then applied to a camera circuit (not shown).
The electric signal is further applied, via a gain control circuit and a band pass filter and like, to a rectifier (all of them not shown) which picks up a specific high frequency component of the signal, and outputs the rectified high frequency component as a foucsing signal. When just-focusing, the focusing signal becomes maximum. The focusing signal is applied to an autofocusing (AF) circuit 5 which drives a motor 6 to slide the imaging lens section 3 to a just-focus point on an optical axis.
If further telephotographing is required, a conversion lens 17 for telephotographing should be attached in front of the front lens section 1.
Problems with the above apparatus are that attachment of the conversion lens to the apparatus takes time and if a conversion lens provided with more than two lenses is attached, the apparatus will become bulky. Further close-photographing under the telephotographing-mode will be impossible, if the conversion lens is attached.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an image pickup apparatus which is compact, capable of further telephotographing without such a conversion lens and close-photographing under the telephotographing-mode.
In carrying out the present invention in one preferred mode, there is provided an image pickup apparatus comprising an optical system, having an optical axis, for forming an image of an object to be taken by receiving light from the object, a photoelectric conversion device for converting the image into an electric signal, a judging section for extracting a high frequency component from the electric signal to determine if the image is in focus by means of level of the high frequency component and a control section responsive to a result of the judgement, for varying a distance between a part of the optical system and the photoelectric conversion device so that the image is in focus, wherein the optical system comprises a first lens section, provided as linearly slidable on the optical axis and having a plurality of click stop positions, for stepwise changing a focal length of the optical system and a second lens section, provided as slidable on the optical axis, for continuously changing the focal length of the optical system, and the control section further varies said distance between the part of the optical system and the photoelectric conversion device in response to a movement of the first lens section among the click stop positions and a slide of the second lens section so that the image is kept in focus.
Other objects and advantages of the present invention will become apparent from the detailed description to follow taken in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a conventional image pickup apparatus;
FIG. 2 is a block diagram of a preferred embodiment of an image pickup apparatus for taking photographs according to the present invention;
FIG. 3 is a graph showing a general relationship between focal lengths and slidable distances of an image pickup device; and
FIG. 4 is a block diagram of another preferred embodiment of the apparatus according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 shows a preferred embodiment of the image pickup apparatus according to the present invention. An optical system 300 shown in the figure comprises a front lens section 30 of convex lens, a zoom lens section 31 having concave lenses 31a and 31b and a fixed imaging lens section 32 having a convex lens 32a, concave lens 32b and convex lens 32c, aligned in order.
A light beam A from an object is, via the optical system 300 and a crystal lowpass filter 33, imaged on an image pickup device (a solid-state image pickup device) 34. The light beam A is converted to an electric signal in the device 34 and the electric signal is applied, via an amplifier 36, to a video circuit 37 where the electric signal is processed so as to be handled as a video signal.
The electric signal is further applied to a band pass filter (BPF) 38 where a high frequency component of the electric signal is extracted for judging if an image on the image pickup device 34 is in focus.
The high frequency component is applied to a gain control amplifier (GCA) 39 where the high frequency component is amplified if amplitude of the component is small, and is then applied to an area sensing circuit 41 where the portion, of the high frequency component, corresponding to a specific image area is extracted and rectified.
The rectified signal is applied, as a focusing signal, to an analog-to-digital converter (A/D) 42 where the focusing signal is converted into a digital focusing signal. The digital focusing signal is then applied to a control circuit 43.
To the control circuit 43, a position signal from a position sensor 44 which detects the position of the image pickup device 34 and other position signals, from position sensors 45 and 46, related to focal length of the zoom lens section 31 and front lens section 30, are also applied.
The focusing signal with respect to slide of the image pickup device 34 in a direction of the optical axis is sampled per field (image) from start of focusing and digitized by the A/D convertor 42 and applied to the control circuit 43.
In the control circuit 43, each focusing signal per field is compared with a next focusing signal in their magnitude one after another to output a differential signal.
Magnitude and polarity of the differential signal are used, with the position signals from the position sensors 44, 45 and 46 to determine the just-focusing position by a known method such as hill climbing method to output a control signal C 1 . The signal C 1 is supplied to a drive circuit 47 which drives a motor 48 to slide the image pickup device 34 to the just-focusing position on the optical axis.
FIG. 3 is a graph showing general relationships between positions of the image pickup device 34 and focal lengths of a compound lens composed of the front lens section 30, zoom lens section 31 and imaging section 32 when images of objects at respective constant distances (object distances) are in focus while the zoom lens section 31 is sliding and the front lens section 30 is on such as the point P 1 in FIG. 2.
The graph teaches that the just-focusing position of the image pickup device 34 varies in finite object distance. The rate of change of the just-focusing position by zooming varies in accordance with the object distance. The nearer the object, the larger the just-focusing point varies.
Therefore, it is required that a focusing point of the image pickup device 34 is corrected by sliding the device 34 in accordance with zooming.
The data-table corresponding to FIG. 3 is previously stored in the control circuit 43. How to use this data-table is explained below.
In FIG. 3, Xa is a position of the image pickup device 34 when the image of an object at a distance of two meters is in focus under a focal length fa. When a zooming switch 49 in FIG. 2 is switched to a zoom-mode for telephoto side from the above state, the control circuit 43 produces a control signal C 2 for sliding the concave lenses 31a and 31b, by referring to the position signal from the position sensor 45.
The concave lenses 31a and 31b are held in a lens-barrel (not shown) in a way that both lenses are relatively slid in the barrel along a cam channel curve formed therein. By detecting a rotational angle of the lens-barrel, the position signal of the concave lenses 31a and 31b are obtained.
The control circuit 43 then supplies the control signal C 2 to a drive circuit 50 which drives a motor 51 to slide the concave lenses 31a and 31b to the positions of a focal length fa' in FIG. 3 in the optical axis direction.
The position signals of the image pickup device 34 and front lens section 30 from the position sensors 44 and 46 are also supplied to the control circuit 43. By means of these signals, the distance of the object, when the focal length is fa and the image pickup device 34 is on the just-focusing position Xa, is determined with referring to the data-table.
Based on the determined distance, the control signal C 1 is supplied to the drive circuit 47 for sliding the image pickup device 34 to the just-focusing position Xa'. Another arrangement can be considered such that the concave lens 32b of the imaging lens section 32 may be slid to the just-focusing position instead of the imaging device 34.
The front lens section 30 is configured such that is is movable among three click stop positions P 1 , P 2 and P 3 on the optical axis and usually set at the position P 1 .
If further telephotographing is desired, a switch 52 is turned on to produce an ON 1 signal which is supplied to the control circuit 43. Based on the ON 1 signal, a drive signal is produced in the circuit 43 and is supplied to a drive circuit 53 which drives a motor 54. The motor 54 quickly and linearly slides the front lens section 30 from the position P 1 to the position P 2 on the optical axis. The front lens section 30 may be manually slid by shutting out a transfer mechanism (not shown) communicated to the motor 54 by such as a clutch mechanism.
All the curves shown in FIG. 3 are shifted to a direction Z with some deformation in accordance with the slide from P 1 to P 2 of the front lens section 30. Because, those curves are established when the front lens section 30 is on the point P 1 as described before.
Values corresponding to that shift and correction values modified by the shift values are previously stored in the table of the control circuit 43. The ON 1 signal from the switch 52 and the location of the front lens 30 which is on the point P 2 are detected to read out one correction value from the table. Based on the correction value, the drive circuit 47 supplies the control signal C 1 to the motor 48 which slides the image pickup device 34 to the just-focusing position on the optical axis.
If macro-photographing is further desired under telephotographing, the switch 52 is turned on again. This produces a second ON 1 signal and the control circuit 43, based on the second ON 1 signal, supplies the drive signal to the drive circuit 53. The drive circuit 53 drives the motor 54 which linearly slides the front lens section 30 to the position P 3 on the optical axis.
Accordingly, all the curves shown in FIG. 2 are further shifted to the direction Z than when the front lens section 30 is positioned on the position P 2 . Because of this, curves (depicted by dash-dotted lines) in a macro area located outer the slidable area of the image pickup device 34, where photographing is impossible are shifted to the area where photographing is possible.
Values corresponding to the shift of the curves when the front lens section 30 is slid to the position P 3 and correction values modified by the shift values are also previously stored in the table in the control circuit 43. One correction value is read out from the table based on the second ON 1 signal from the switch 52 and a detection signal produced when the front lens section 30 on the position P 3 . By the correction value, the image pickup device 34 is slid to the just-focusing position to enable macro-photographing.
If the front lens section 30 is desired to be returned rightward in the figure, a switch 57 is turned onto produce an ON 2 signal which is supplied to the control circuit 43, accordigly causing the drive motor 54 to slide the front lens section 30 from P 3 to P 2 or from P 2 to P 1 . And the image pickup device 34 is slide by a correction opposite to the above cases.
According to the preferred embodiment, the front lens 30 is slid for changing the magnification of the image and the imaging lens section 32 or the image pickup device 34 is slid for just-focusing so that a conversion lens for telephotographing is eliminated and telephotographing function is improved.
Furthermore, lens-diameter of each lens section is made shorter and number of lenses is made less compared to when the conversion lens is attached.
Since, the front lens section 30 is provided as the lens for changing the magnification of the image, it is suitable for manual operation. Actually, the front lens section 30 is arranged as linearly slidable such that it quickly responds to manual operation.
Macro-photographing is made possible under telephotographing, when the front lens section 30 is slid to the position P 3 .
When focusing is done by a motor not manual operation, the correction values corresponding to the slide of the image pickup device 34 based on the curves shown in FIG. 2 and the shift corresponding to switching among the positions P 1 , P 2 and P 3 are stored in the table of the control circuit 43. Quick auto-focusing is thus conducted as described in the above preferred embodiment.
Arrangement of the image pickup device 34 such that it is slid for focusing instead of the optical system 300 allows space between the lenses in the system 300, to be shortened. This makes the apparatus according to the present invention be more compact than that in which an imaging lens section is slid in the case of focusing.
FIG. 4 shows another preferred embodiment of the apparatus according to the present invention. Reference numerals in FIG. 4 which are the same as shown in FIG. 2 designate like or equivalent elements, so that explanation of those elements is omitted.
In FIG. 4, an optical system 300a comprises a fixed front lens section 60, a zoom lens section 31 having concave lenses 31a and 31b and an imaging lens section 62 having a convex lens 62a, a concave lens 62b (combination of both lenses exhibiting the characteristics of convex lens) and a convex lens 62c.
In usual telephotographing, switching of a zoom switch 49 to a zoom-mode allows the lenses 31a and 31b of the zoom lens section 31 to be slid in a specific direction to obtain a closed-up image.
The concave lens 62b of the imaging lens section 62 is configured such that it slides to three click stop positions P 1 , P 2 and P 3 for changing the magnification of the image. The position P 1 is for normal telephotographing.
If further telephotographing is desired, a switch 64 is turned on. This produces an ON 3 signal which is supplied to a drive circuit 66 to drive a motor 68. The lens 62b is slid to the position P 2 on the optical axis.
This slide to the position P 2 is detected by a position sensor 69 which produces a position signal. This position signal is supplied to a control circuit 43.
By means of the position and ON 3 signals, a correction value which is prestored in a data-table of the control circuit 43 and modified by the shift of the lens 62b is read out from the table.
The image pickup device 34 is slid to a just-focusing position, based on the correction value, to obtain a closed-up image which is bigger than one under the normal telephotographing.
Next, when the switch 64 is turned on again, the concave lens 62b is slid to the position P 3 . Like the former embodiment, the curves (depicted by dash-dotted lines) in macro area located outside of the slidable area of the image pickup device 34 are shifted in the direction Z in FIG. 3 to enable macro photographing under the telephotographing mode.
When the concave lens 62b is desired to be returned from P 3 to P 2 or from P 2 to P 1 , a switch 65 is turned on.
The operation of the control circuit 43 and use of the data-table provided therein are the same as explained in the former embodiment. Difference between the former and later embodiments is that the front lens section 30 in the former is to be slid among the three click stop points P 1 , P 2 , and P 3 while the imaging lens section 62 is in the latter.
The concave lens 62b of the imaging lens section 62 is arranged as the lens for changing the magnification of the image in the latter embodiment. Compared to the former case in which the front lens section is used for changing the magnification of the image, configuration of the lens section 62 is made compact so that a small power motor is available and also power consumption is made less if the apparatus of the present invention is battery-powered.
The above two embodiments are for telephotographing. Not only that, the present invention can be applied to wide-range photographing in which a multi-mode lens section is slid in a reverse direction to the case of telephotographing.
Furthermore, the control circuit 43 is provided for auto-focusing in the above two embodiments, manual focusing is available by a known mechanism.
While the presently preferred embodiments of the present invention have been shown and described, it is to be understood these disclosures are for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | There is provided an image pickup apparatus with zooming function, which is equipped with a photoelectric converter for converting an image of an object to be taken by an optical system into an electric signal. The optical system and photoelectric converter are provided as separately slidable on an optical axis. A high frequency component of the electric signal is extracted to determine if the image is in focus by means of level of the high frequency component. Responding to the result of the judgement, the optical system and photoelectric converter are respectively slid to click stop points on the optical axis where the image is in focus. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to and claims benefit of U.S. Provisional Patent application Ser. No. 60/496,176, docket number ABS2003-002P, filed on Aug. 19, 2003, by Derek J. Layfield.
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT STATEMENT
[0002] This invention was not developed in conjunction with any Federally sponsored contract.
MICROFICHE APPENDIX
[0003] Not applicable.
INCORPORATION BY REFERENCE
[0004] The related U.S. Provisional Patent application Ser. No. 60/496,176, docket number ABS2003-002P, filed on Aug. 19, 2003, by Derek J. Layfield, in hereby incorporated by reference in it entirety, including figures.
BACKGROUND OF THE INVENTION
[0005] In modem office buildings, business and conference centers, hotels, classrooms, medical facilities, and the like, the fitting-out of occupiable space is continuously becoming more important and ever more challenging. In the competitive business environment, cost concerns alone dictate the efficient use of interior space. Thus, the finishing or fitting-out of building spaces for offices, hotel rooms, and similar areas has become a very important aspect of effective space planning and layout. Among many factors that designers and builders must consider is sound control. In hotels, for example, the prevention of sounds originating in one room from passing through walls and into adjacent rooms is of major concern.
[0006] Sound transmission through walls is typically expressed according to one of two single-number rating systems—Sound Transmission Class (STC) and Weighted Sound Reduction Index (R w ). Both are single-figure ratings schemes intended to rate the acoustical performance of a partition element under typical conditions involving office or dwelling separation. The higher the value of either rating, the better the sound insulation. The rating is intended to correlate with subjective impressions of the sound insulation provided against the sound of speech, radio, television, music, office machines and similar sources of sound characteristic of offices and dwellings.
[0007] The first rating system is called Sound Transmission Class (STC). STC is defined by the American Society for Testing Materials (ASTM) standard E 413. To assign an STC rating to a barrier separating two rooms, a sound is generated in one of the rooms, the sound power is measured on both sides of the barrier, and the ratio between the two measurements (the transmission loss) is stated in decibels. Sixteen measurements are made in each room, at ⅓ octave intervals from 125 HZ to 4000 HZ. The higher the STC rating, the greater the sound transmission loss. The E413 standard specifies a transmission loss curve having 16 points on the same ⅓ octave intervals. From 125 to 400 Hz, the curve slopes upward, 9 dB per octave; from 400 Hz to 1250 Hz, upward 3 dB per octave, and it is flat from 1250 Hz to 4000 Hz. The curve is moved up and down until the sum of all 16 differences between the curve values is a minimum. The Minimum must be less than 32 dB, providing no single difference is more than 8 dB. The rating is then expressed as the curve's loss in decibels at 500 Hz.
[0008] The second rating system is called Weighted Sound Reduction Index (“R w ”) and is defined by International Standards Organization standard ISO 717. Test procedure for R w are similar to STC except the frequency range for R w spans 100-3150 HZ whereas, as indicated supra, STC covers a frequency range of 125-4000 Hz. STC and R w correlate very well. For architectural elements such as doors, windows and walls, differences in STC and R w are typically less than 1%.
[0009] Interior walls in offices, hotels and the like are typically made by erecting a frame that includes vertical studs, either wood or steel, on a 12″ or 16″ spacing, lining each side with gypsum board (sheet rock) panels, then finishing the wall surfaces with a variety of textures and paint. When additional thermal and/or acoustic insulation is needed, insulation medium such as fiberglass, rock wool or mineral wool will commonly be placed to fill the interior space between vertical studs and gypsum board panels. FIGS. 1 a - 1 d illustrate a cross-sectional top-down view of such constructions.
[0010] FIG. 1 ( a ) shows prior art wall construction ( 100 ) comprised of vertical 2×4 studs ( 102 ) lined on each side by ⅝″ gypsum board ( 101 ), with an air space ( 103 ) in between. The wall construction of FIG. 1 a will typically have a Rw value of 33 and will be ˜4¾″ wide between exterior surfaces.
[0011] FIG. 1 ( b ) shows prior art wall construction ( 200 ) comprised of vertical 2×4 studs ( 202 ) lined on each side by ⅝″ gypsum board ( 201 ) with insulation ( 203 ) filling the interior space. The wall construction of FIG. 1 ( b ) will typically have a Rw value of 38 and will be ˜4¾″ wide between exterior surfaces.
[0012] FIG. 1 ( c ) shows prior art wall construction ( 300 ) comprised of 3⅝″ vertical steel studs ( 302 ) lined on each side by ⅝″ gypsum board ( 301 ) with air space ( 303 ) in between. The wall construction of FIG. 1 ( c ) will typically have a Rw value of 33 and will be ˜4⅞″½″ wide between exterior surfaces.
[0013] FIG. 1 ( d ) shows prior art wall construction ( 400 ) comprised of 3⅝″ vertical steel studs ( 402 ) lined on each side by ⅝″ gypsum board with insulation ( 403 ) filling the interior space. The wall construction of FIG. 1 ( d ) will typically have a Rw value of 40 and will be ˜4⅞″ wide between exterior surfaces.
[0014] These conventional walls have proven over time to be sturdy, provide adequate privacy, and provide a surface that easily accepts wall hangings such as pictures, paintings, plaques and the like. Furthermore, as is commonly known, conventional walls can easily be repainted, retextured, and, readily patched and repaired when damaged. However, the acoustic properties of walls constructed by this method provide acoustic properties that often do not meet user needs.
[0015] To increase the sound attenuating properties of walls, numerous alternative practices have been used FIGS. 1 ( e )- 1 ( g ) provide top-down cross-sectional views of alternative constructions. It can be seen by comparison the FIGS. 1 ( a )- 1 ( d ), the wall constructions shown in FIGS. 1 ( e )- 1 ( g ) each have an overall wall thickness that
[0016] FIG. 1 ( e ) shows a prior art wall construction ( 500 ) wherein vertical 2×4 studs ( 502 ) are placed in a staggered configuration such that no direct rigid connection is made between gypsum board panels ( 501 ) lining each wall face. Insulation ( 503 ) is used to fill interior spaces. The overall wall thickness of prior art wall construction ( 500 ) typically exceeds 6″.
[0017] FIG. 1 ( f ) shows a prior art wall construction wherein vertical 2×4 studs ( 602 ) are placed in a two-wide configuration effectively doubling the overall wall thickness to ˜9″. Gypsum board ( 601 ) lines each face and insulation ( 603 ) fills interior spaces.
[0018] FIG. 1 ( g ) is similar to FIG. 1 ( f ) except the two-wide 2×4 studs are replaced by 7″ steel studs ( 702 ) and two layers of gypsum board ( 701 ) are used on one side. Insulation ( 703 ) is used to fill interior spaces. The wall constructions illustrated in FIGS. 1 ( f ) and 1 ( g ) are able to provide R w values of up to 52. The wall construction of FIG. 1 ( g ) has an overall thickness of ˜9″ and, by way of the double layer of gypsum board on one face, provides a one hour fire rating as required by many commercial applications such as hotel constructions.
[0019] Due to the ever increasing cost associated with commercial and residential construction and the subsequent need to maximize interior space while minimizing costs, there is a need in the art for economical interior wall constructions that provide both sound attenuating and fire resistance properties while minimizing wall thickness.
[0020] Further, since no two applications are identical, the need exists for such a system that provides the versatility to easily customize wall height and width to fit each individual application. The invention disclosed herein meets these needs, as well as providing a wall construction that can be made primarily of recycled materials. The invention disclosed herein represents a significant improvement over existing art.
[0021] The compressed straw panels described in the disclosure contained herein, possess structural and acoustical properties very well suited for economically constructing interior walls with superior sound attenuating and fire resistant properties.
[0022] For comparison, FIG. 1 ( h ) provides a cross-sectional top-down view of a very simple wall construction that utilizes said compressed straw panel.
[0023] FIG. 1 ( h ) shows a 2¼″ compressed straw panel ( 801 ) lined on each side by ⅝″ gypsum board ( 802 ). Attachment is typically made by means of adhesives and or conventional fasteners such as nails or screws. The wall construction illustrated in FIG. 1 ( h ) has an overall thickness of 3½″ and provides an R w value of 39.
[0024] Lacking in the art are interior wall construction methods that effectively utilize the favorable structural, acoustic and combustion properties of said compressed straw panels, especially the favorable properties achieved when used in concert with resilient channel members that define a space on one or both sides of a compressed straw panel.
SUMMARY OF THE INVENTION
[0025] The present invention relates to interior wall constructions. More particularly, the present invention relates to improved interior wall constructions that do not require vertical studs. Further, the present invention relates to improved interior wall constructions that utilize compressed straw panels in lieu of studs, either wood or otherwise. Further, said improved interior wall constructions provide improved sound attenuating properties and comparable fire resistance properties to conventional wall constructions with less wall thickness, thus better utilizing interior space.
[0026] In a preferred embodiment of subject wall construction, the present invention comprises a generally sandwich configuration with gypsum board sheets lining each of two faces of the wall. A compressed straw panel is situated between the gypsum board sheets in substantially planar orientation thereto. The compressed straw panel is connected to one of the gypsum board sheets by means of a plurality of resilient Z-channel connector members. The compressed straw panel is connected to the second gypsum board sheet by means of a rigid, non-resilient connector. Both connections define an air space located between the compressed straw panel and the gypsum board sheets attached thereto. Said air space defined by the resilient connectors is partially filled by a non-woven insulating medium. The air space defined by the non-resilient connector remains empty. Compressed straw panel edge to edge connections utilize a steel H-channel member that fully engages the ends of two straw panels. Gypsum board sheet joints are aligned adjacent to said H-channel such that the steel H-channel member acts to eliminate a burn path between abutted straw panels and abutted gypsum board sheets.
[0027] The features and advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The figures presented herein when taken in conjunction with the written disclosure form a complete description of the invention.
[0029] FIG. 1 ( a - d ) referred to supra, shows individual top-down cross-section views of prior art wall constructions.
[0030] FIG. 1 ( e - g ) also referred to supra, shows individual top-down cross-section views of prior art wall constructions.
[0031] FIG. 1 ( h ) shows an individual top-down cross-section view of a prior art wall construction utilizing a compressed straw panel.
[0032] FIG. 2 ( a ) shows an isometric cutaway view of the preferred embodiment of subject invention.
[0033] FIG. 2 ( b and c ) shows a top-down cross-section view of a wall joint of the preferred embodiment in exploded form (b) and assembled form (c).
[0034] FIG. 2 ( d ) shows a cross-section side view of the preferred embodiment.
[0035] FIG. 3 ( a ) shows an isometric cutaway view of a first alternative embodiment of subject invention.
[0036] FIG. 3 ( b ) shows a top-down cross-section view of a wall joint of the first alternative embodiment.
[0037] FIG. 3 ( c ) shows a cross-section side view of the first alternative embodiment.
[0038] FIG. 4 ( a ) shows an isometric cutaway view of a second alternative embodiment of subject invention.
[0039] FIG. 4 ( b ) shows a top-down cross-section view of a wall joint of the second alternative embodiment.
[0040] FIG. 4 ( c ) shows a cross section side view of the second alternative embodiment.
[0041] FIG. 5 ( a and b ) shows individual detailed views of a Z-channel member in an isometric view (a) and a cross-section side view (b).
[0042] FIG. 6 shows a simple cutaway isometric view of an individual compressed straw panel.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The invention herein comprises a novel combination of five elements. Said elements being a compressed straw panel, a first resilient channel member, a second resilient Z-shaped channel member, insulating medium, gypsum board sheets, and properly placed air spaces.
[0044] The improved interior wall construction disclosed herein includes a number of individual components, but is generally designed around a compressed straw panel. In the preferred embodiment, compressed straw panels such as those manufactured by Affordable Building Systems of Texas are utilized. Each compressed straw panel is composed of highly compressed straw, typically wheat, rice, oat or other recovered agricultural straw lined on all exterior sides by paper or paperboard. Compressed straw panels are typically made through a dry extrusion process wherein straw is compressed into a substantially flat continuous web, normally between 1″ and 3″ thick and between 30″ and 65″ wide. As previously mentioned, the continuous web is lined on all sides by paper or paperboard. The continuous web is then cut into rectangular panels of various lengths. FIG. 6 is an isometric cutaway view of a simple compressed straw panel ( 1 ) showing the compressed straw fibers ( 12 ) and the paperboard liner ( 11 ). The compressed straw ( 12 ) is arranged in layers with the straw fibers substantially parallel in orientation extending transversely across the panel from side to side when the panel is in a normal in-use orientation. For reference, a typical completed panel will measure 4′×8′. When used, compressed straw panels will typically be oriented such that the longer edges are substantially vertical and the shorter edges are substantially horizontal. In this orientation, said compressed straw fibers ( 12 ) will assume a generally horizontal orientation.
[0045] Further, the compressed straw panels utilized in the invention disclosed herein provide a substantial structural base around which interior walls are easily constructed. A typical 4′×8′ compressed straw panel of 2¼″ thickness has a rack load rating of 1,103 lbs.—allowable and 2130 lbs.—ultimate, and a transverse load rating of 35.1 lbs./ft 2 —allowable and 105.2 lbs./ft 2 —ultimate, as tested and rated according to ASTM E72-98. These panels are well suited for accepting nails, screws, and the like as evidenced by a nail pull rating of 109 lbs. as tested and rated according to ASTM C473-00. The strength of said compressed straw panels provide for a stud-less wall construction.
[0046] The acoustic and combustion properties of the compressed straw panels are of particular importance to the invention disclosed herein. A 2¼″ thick panel has Class A flame spread rating (FSI=10, SDI=45) as tested and rated according to ASTM E-84, and an STC and R w rating of 36 as tested and rated according to ASTM E90-99, E413-87, E1132-90, and ISO 717. The preferred embodiment herein disclosed infra, provides a one hour fire rating on both sides as tested and rated according to ASTM E-119.
[0047] The detailed description will continue with a figure by figure view of each embodiment of the subject wall construction.
[0048] FIG. 2 ( a ) shows a cutaway isometric view of the preferred embodiment. As illustrated, the wall construction disclosed herein comprises a substantially sandwich configuration wherein each component is aligned in a substantially planar relative configuration. Compressed straw panel ( 1 ) is attached on first face to a plurality of rail channels ( 5 ) via attachment means ( 10 ). Said attachment means ( 10 ) may be a penetrating fastener such as a nail or screw, a strong adhesive such as an epoxy resin, or any combination thereof. Attachment means ( 10 ) are illustrated herein as penetrating fasteners. Said rail channels ( 5 ) are then attached to a first gypsum board sheet ( 3 ) via attachment means ( 10 ). Again said attachment means ( 10 ) may be a penetrating fastener such as a nail or screw, a strong adhesive such as an epoxy resin, or any combination thereof. Said first gypsum board sheet ( 3 ) comprises a first outer face of said wall construction. Said rail channels provide a first air space ( 8 ) between compressed straw panel ( 1 ) and said first gypsum board sheet ( 3 ). Compressed straw panel ( 1 ) is attached on second face to a plurality of Z-channels ( 2 ). As illustrated, each Z-channel is then attached to a second gypsum board sheet ( 3 ) that comprises a second outer face of said wall construction. Attachment means ( 10 ) between said Z-channels ( 2 ) and said compressed straw panel ( 1 ), and between said Z-channel ( 2 ) and said gypsum board sheet ( 3 ) can comprise any conventional attachment means such as nails, screws, adhesives, or any combination thereof. Rail channels ( 5 ) and Z-channels ( 2 ) should be situated in substantially parallel, but horizontally staggered orientation, as illustrated in FIG. 2 ( a ), in order to minimize sound transmission therethrough. Further, a configuration wherein a rail channel ( 5 ) and Z-channel ( 2 ) lie in the same horizontal plane on opposing sides of compressed straw panel ( 1 ) produces an improved path for sound transmission and is therefore undesirable. For comparison, the preferred embodiment, shown by FIGS. 2 ( a - d ) provides a minimum Rw value of 57 while having an overall wall thickness of ˜5′.
[0049] Referring now to FIG. 2 ( d ), it can be seen that placed adjacent to said second face of compressed straw panel ( 1 ) is an insulation material ( 4 ). Said insulation is preferably a non-woven material made of fiberglass, rock wool or mineral wool with a density in the range of 0.7-4.0 lbs/ft 3 (11.2-64.2 kg/m 3 ). In the preferred embodiment, insulation material ( 4 ) is fiberglass with a density of 2 lbs/ft 3 and a thickness of 3 in. Importantly, said insulation ( 4 ) does not completely fill the space between compressed straw panel ( 1 ) and second gypsum board panel ( 3 ) and provides for a second air space ( 9 ) between said insulation ( 4 ) and said second gypsum board panel ( 3 ). It is recommended that said insulation ( 4 ) be attached to said compressed straw panel to insure that second air space ( 9 ) is not compromised. The preferred attachment between said insulation ( 4 ) and said compressed straw panel ( 1 ) is by adhesive. Many commercially available adhesives are suitable, and a polyvinyl acetate based adhesive is preferred.
[0050] Still referring to FIG. 2 ( d ) said first air space ( 8 ) between compressed straw panel ( 1 ) and first gypsum board panel can be seen. In the preferred embodiment, first air space ( 8 ) is approximately ½″ wide and second air space ( 9 ) is approximately 1″ wide.
[0051] Referring now to FIG. 2 ( b ), an exploded sectional top-down view of a wall joint of the preferred embodiment is shown. It can be seen that steel H-channel ( 6 ) is further comprised of first receiving channel ( 61 ) and second receiving channel ( 62 ) each of which is sized to securely accept an edge of one compressed straw panel therein. Said receiving channels ( 61 & 62 ) are preferrably sized to provide a tight fit between H-channel ( 6 ) and compressed straw panel ( 1 ) such that supplemental attachment means such as screws or nails are not needed to maintain retention after initial insertion.
[0052] FIG. 2 ( c ) shows the same wall joint in a fully assembled configuration. Importantly, FIG. 2 ( c ) illustrates that the gypsum board joints ( 7 ) between each gypsum board sheet ( 3 ) are substantially aligned with the middle of said H-channel ( 6 ) as shown. Gypsum board joints ( 7 ) wherein two gypsum board panels are aligned in an edge to edge abutted relationship create a burn through path for fires. Said alignment between gypsum board joints ( 7 ) and H-channel ( 6 ) places a steel fire resistant barrier in the burn through path, thus imparting important fire resistance properties to subject wall construction.
[0053] Referring to FIG. 3 ( a ), an isometric cutaway view of a first alternative embodiment is shown. The first alternative embodiment also comprises a substantially sandwich configuration with each component aligned in substantially planar relative configuration. Compressed straw panel ( 1 ) is attached on first face to a plurality of Z-channel members ( 2 ) via attachment means ( 10 ). As with the preferred embodiment, said attachment means ( 10 ) may be a penetrating fastener such as a nail or screw, a strong adhesive such as an epoxy resin, or any combination thereof Said Z-channels ( 2 ) are then attached to a first gypsum board sheet ( 3 ) via attachment means ( 10 ). Again said attachment means ( 10 ) may be a penetrating fastener such as a nail or screw, a strong adhesive such as an epoxy resin, or any combination thereof. Said first gypsum board sheet ( 3 ) comprises a first outer face of said wall construction. As illustrated in FIG. 3 ( a ), the space between compressed straw panel ( 1 ) and first gypsum board sheet ( 3 ) is filled by insulation ( 4 ). In the first alternative embodiment, said insulation ( 4 ) is preferably a non-woven material made of rock wool or fiberglass and in a bat form. Compressed straw panel ( 1 ) is attached on second face to a plurality of Z-channels ( 2 ). As illustrated, each Z-channel is then attached to a second gypsum board sheet ( 3 ) that comprises a second outer face of said wall construction. Attachment means ( 10 ) between said Z-channels ( 2 ) and said compressed straw panel ( 1 ), and between said Z-channel ( 2 ) and said gypsum board sheet ( 3 ) can comprise any conventional attachment means such as nails, screws, adhesives, or any combination thereof. As illustrated, Z-channels ( 2 ) on opposite sides of compressed straw panel ( 1 ) should be substantially parallel, but horizontally staggered orientation in order to minimize sound transmission therethrough. A configuration wherein two Z-channel ( 2 ) lie in the same horizontal plane on opposing sides of compressed straw panel ( 1 ) produces an improved path for sound transmission and is therefore undesirable. In the first alternative embodiment, insulation ( 4 ) is preferably attached to compressed straw panel ( 1 ) by means of glue, adhesive or other suitable fastening means.
[0054] FIG. 3 ( b ) shows a sectional top-down view of a wall joint of the first alternative embodiment. As with the preferred embodiment, H-channel ( 6 ) fully accepts the edge of two compressed straw panels ( 1 ) therein as shown. As with the preferred embodiment, gypsum board joints ( 7 ) between each gypsum board sheet ( 3 ) are substantially aligned with the middle of said H-channel ( 6 ) to preclude a burn through path.
[0055] From FIG. 3 ( c ), a sectional side view of first alternative embodiment, it can be seen that insulation ( 4 ) is placed adjacent to both first and second face of compressed straw panel. As with the preferred embodiment, said insulation is a non-woven material made of fiberglass, rock wool or mineral wool with a density in the range of 0.7-4.0 lbs/ft 3 (11.2-64.2 kg/m 3 ). In the first alternative embodiment as illustrated, insulation ( 4 ) completely fills the space between first and second face of compressed straw panel ( 1 ) and first and second gypsum board sheets ( 3 ). The only exception being the small space above and below Z-channel ( 2 ) that is created due to the non-right angle of said Z-channel. As previously mentioned, It is recommended that said insulation ( 4 ) be attached to said compressed straw panel by adhesive or other suitable means.
[0056] Referring to FIG. 4 ( a ), an isometric cutaway view of a second alternative embodiment is shown. The second alternative embodiment also comprises a substantially sandwich configuration with each component aligned in substantially planar relative configuration. Compressed straw panel ( 1 ) is attached on first face directly to a gypsum board sheet ( 3 ) by attachment means ( 10 ). Said first gypsum board sheet comprises first outer face of wall construction. In this embodiment, attachment means ( 10 ) may be a penetrating fastener such as a nail or screw, a strong adhesive such as an epoxy resin, or any combination thereof. Compressed straw panel ( 1 ) is attached on second face to a plurality of Z-channels ( 2 ). As illustrated, each Z-channel is then attached to a second gypsum board sheet ( 3 ) that comprises a second outer face of said wall construction. Attachment means ( 10 ) between said Z-channels ( 2 ) and said compressed straw panel ( 1 ), and between said Z-channel ( 2 ) and said gypsum board sheet ( 3 ) can comprise any conventional attachment means such as nails, screws, adhesives, or any combination thereof. As illustrated, Z-channels ( 2 ) should be positioned in substantially parallel relative orientation. In the second alternative embodiment, as illustrated, insulation ( 4 ) completely fills the space between second face of compressed straw panel ( 1 ) and second gypsum board sheet ( 3 ) and is preferably attached to compressed straw panel ( 1 ) by means of glue, adhesive or other suitable fastening means.
[0057] FIG. 4 ( b ) shows a sectional top-down view of a wall joint of the second alternative embodiment. As with previous embodiments, H-channel ( 6 ) fully accepts the edge of two compressed straw panels ( 1 ) therein as shown, and gypsum board joints ( 7 ) between each gypsum board sheet ( 3 ) are substantially aligned with the middle of said H-channel ( 6 ) to preclude a burn through path.
[0058] In FIG. 4 ( c ) a sectional side view of second alternative embodiment is shown. Here it can be seen that insulation ( 4 ) is placed between second face of compressed straw panel ( 1 ) and second gypsum board sheet ( 3 ). Said insulation ( 4 ) completely fills the space therebetween except for just above and below Z-channels ( 2 ) as shown. Here again, it is recommended that said insulation ( 4 ) be attached to said compressed straw panel by adhesive or other suitable means.
[0059] An important element of this invention is the Z-channel. FIGS. 5 ( a ) and 5 ( b ) illustrate an isometric and cutaway view of the Z-channel respectively. Referring first to FIG. 5 ( a ), the Z-channel ( 2 ) is comprised of three substantially flat elements, spine member ( 20 ), first flange member ( 21 ) and second flange member ( 22 ). In the preferred embodiment, Z-channel ( 2 ) has resilient characteristics and is made light gauge steel ( 20 gauge). Z-channel ( 2 ) can be made of any material with a Young's modulus equal to or less than 30×10 6 lbs/in 2 (206.8 Gpa), and a melting temperature equal to or greater than 2500° F. (1370° C.). FIG. 5 ( b ) further illustrates the angles a and b between spine member ( 20 ) and flange members ( 21 ) and ( 22 ) respectively. In the preferred embodiment, angles a and b, which are equal, are each greater than 98°. For illustration, FIG. 5 ( b ) shows angles of 110°.
[0060] As discussed herein, the disclosure comprise improved interior wall constructions. The walls can be constructed as disclosed and repeated in planar side by side fashion to construct continuous walls of the length desired. It is recommended that the wall finished wall height constitute one panel. In other words an 8′ high wall should be constructed compressed straw panels 8′ in length placed in continuous side by side fashion with panel joints achieved as illustrated in FIGS. 2 ( c ), 3 ( b ) and 4 ( b ). Attachment of the disclosed walls at the top and bottom to a ceiling and floor respectively may be done by any conventional means and is not within the scope of this invention. Termination of the disclosed walls at an exterior wall or abutting to another interior wall may also be done by any conventional means and is not within the scope of this invention.
[0061] The gypsum board sheets referred to herein are preferably ⅝″ type-X gypsum board as commonly manufactured by most gypsum board manufacturers. As with normal drywall installation, gypsum board sheets utilized in the wall construction disclosed herein can be cut, sized, taped, bedded, textured and finished as with conventional drywall applications.
[0062] Those skilled in the art will recognize that certain variations or alternative embodiments are easily accomplished with the invention disclosed herein. For example, the individual concepts can easily be used with core panels made from alternative materials. Further, alternative materials may well be used in the various component parts without deviating from the invention claimed herein.
[0063] The embodiments shown and described above are exemplary. Many details are often found in the art and, therefore, many such details are neither shown nor described. It is not claimed that all of the details, parts, elements, or steps described and shown were invented herein. Even though numerous characteristics and advantages of the present inventions have been described in the drawings and accompanying text, the description is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the inventions to the full extent indicated by the broad meaning of the terms of the attached claims.
[0064] The restrictive description and drawings of the specific examples herein do not point out what an infringement of this patent would be, but are to provide at least one explanation of how to use and make the inventions. The limits of the inventions and the bounds of the patent protection are measured by and defined in the following claims. | An improved interior wall construction that provides both sound attenuating and fire resistant properties. The improved wall construction eliminates the need for conventional vertical studs by including at least one rigid interior structural panel comprised of compressed straw. A compressed straw panel is situated in a substantially layered configuration with conventional non-woven insulation, at least one air space and a gypsum board sheet on each face. Connection between the compressed straw panel and at least one gypsum board sheet is comprised semi-flexible substantially Z-shaped resilient channel members. The Z-shaped channel members and compressed straw panel each being capable of partially attenuating sound energy passed therethrough. | 4 |
TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to a method for the cosmetic treatment of dark spots on the skin and is intended to eliminate said dark spots on the hands, face, limbs or chest of a person suffering from such skin hyperpigmentation on the one hand and, a device for the application of said method on the other hand.
[0002] Melanogenesis, by means of specialised cells called melanocytes, at the origin of skin colour, is influenced by external factors that increase the production of melanin and, as a result, a localised darker colour. This gives rise to the formation of dark spots on the skin.
[0003] Dark spots (lentigines, actinic dermatitis) may appear as of the age of 30 years, sometimes as of adolescence, and are mainly located on the hands, face and chest. In particular, they result from over-exposure to the sun. Skin ageing refers to all of the consequences of the sun on the skin, such as blemishes, sagging skin, wrinkling, a wrinkled appearance and dry skin. This may occur on the spots by:
sun spots or “freckles”, whose number and intensity increase with exposure to ultraviolet light; solar lentigos of the areas overexposed to the sun; hyperchromia (abnormal pigmentation) such as melisma, whose intensity is directly related to exposure to ultraviolet A and B; “perfume dermatitis” resulting from photosensitisation induced by a perfume.
[0008] Intrinsic skin ageing causes atrophy accompanied by sagging skin, dryness and pigmentation disorders. The main pigment disorder is senile lentigo appearing towards the age of fifty on the exposed parts of the skin and, more specifically, on the back of the hands and sometimes on the face. Small, smooth, flat, dark spots, ranging from several millimetres to severs centimetres in diameter. The prognosis is always benign. These spots may also develop in the elderly person, due to inflammation or hormonal imbalance.
[0009] They are considered to be more or less aesthetic depending on the intensity of the hyperpigmentation. The original cause is poorly known. The physiological consequences have been better studied: (1) increase in the synthesis of melanin, (2) acceleration of the transfer of melanin from the melanosomes to the keratinocytes and finally (3) the faster migration of the melanocytes to the skin surface.
STATE OF THE PRIOR ART
[0010] Two means of treatment are possible: the reduction in the hyperpigmentation or the destruction of the melanin or the hyper-pigmented tissue.
[0011] The hyperpigmentation may be reduced by de-pigmenting agents with a pharmacological action, that act on the physiological consequences. By way of example, we can mention; hydroquinone monomethyl ether, mequinol, tretinoin or kojic acid. The length of treatment is long and the means of application are constraining (several applications per day). Therefore, the compliance is low. In addition, the risk of recurrence is very high since the original cause has not be dealt with. The patient can carry out this treatment at home and the help of a dermatologist is not necessary. The secondary and adverse effects are mainly local inflammatory reactions, allergic reactions to the active ingredients and a burning sensation with certain active ingredients.
[0012] Topical steroids have a certain depigmenting potential, especially when applied under an occlusive dressing. They are used in hydroquinone creams although this is more to reduce the irritation resulting from the preparation than to increase the efficacy. Hydroquinone monobenzyl ether should be avoided at all costs. Indeed, it is very powerful and unwieldy and often produces depigmentation at a distance from the treated area. In the past, it has resulted in severe cosmetic accidents, with definitive leukomelanoderma. Some practitioners still use it in the treatment of extensive vitiligos to complete the depigmentation of the areas of healthy skin. However, this requires two applications per day over several months with a concentration of 5 to 20%. In addition, this product may be irritating or allergenic.
[0013] The destruction of the melanin or more generally the hyper-pigmented tissue is based on cryotherapy carried out by the dermatologist, that is, the application of cold on the surface to treat by a health professional. This classic and ancient professional technique does not allow for the control of the level or length of exposure at the temperature obtained.
[0014] Indeed, the dermatologist uses a cylinder to spray gases that in general are at very low temperatures such as liquid nitrogen at −196° C., without being able to precisely control the flow and the spraying time since they mechanically trigger the opening of the cylinder of cryogenic gas. By convention, doctors have defined durations for the application of the cold based on the type of problem to treat, but without any other precision.
[0015] Therefore, the liquid nitrogen should be applied on a common wart once for 10 seconds, on a plantar wart twice between 20 and 30 seconds and on a solar lentigo once for 5 seconds. The lack of precision and control of the duration of the application of the cold and the level of the very low temperatures to apply results in a major disparity in treatments, a total lack of reproducibility and therefore, considerable variations in the efficacy obtained.
[0016] In addition, the use of liquid nitrogen (−196° C.) provokes a second-degree burn, resulting in necrosis of the entire population of the cells in the treated tissue, without any differentiation, resulting in residual scaring, increased risk of hypo-pigmentation and pain upon application.
[0017] The other techniques consist of peeling and microdermabrasion that superficially attenuate the colour of the dark spot without eliminating it, and finally, laser treatment that has the same disadvantages as that of cryotherapy.
[0018] Conventional cryotherapy is used on certain skin lesions, such as actinic lentigos. The technique is highly variable depending on the equipment used to apply the cold. Dermatologists mainly spray liquid nitrogen on the surface to destroy. The sprays may be open or closed, the nitrogen projected in neophrene cones whose size is adapted to the area to treat. This method often follows curettage of the area to treat so as to be able to take a sample for a histological examination and more precisely determine the boundaries of the extension so as to optimise the results. One or several freeze-thaw cycles are thereby carried out and, in general, two cycles are carried out.
[0019] Another method consists of applying liquid nitrogen by means of closed cryodes whose size is adapted to the target surface. Control of the intra-tissue temperature using needles, thermocouple or impedanziometry is possible but not systematically used. The existence of a freezing halo at the periphery of the target area and the freezing and thawing times are used to assess tissue destruction. This is a relatively simple, ambulatory technique that can be used to treat multiple lesions and is not counter-indicated for patients on anticoagulants. The cryonecrosis evolves over several weeks and requires the change of dressings. It may give rise to hypo- or hyper-pigmented dyschromaic sequelae.
[0020] When the dark spots are abundant or very big, a treatment with liquid nitrogen is too violent and it is preferable to use, for example, dry ice or N20.
[0021] U.S. Pat. No. 7,963,959 describes an automated device guided by a system of image acquisition for the treatment of many skin areas using a variety of fluids for cryotherapy, including CFCs. This device is intended for use in a medical setting.
[0022] Patent applications FR 2 885 059 and FR 2 885 539 describe manual devices used to apply a cryogenic fluid in a supply of aerosol on an area of the skin to be treated, via a nozzle and an ejection nozzle. A mechanical timer controls the length of exposure. These devices are designed to enable treatment outside of a hospital or medical environment. However, management of the flow of fluid and length of application have been found to be, in practice, not controlled, little reliable and difficult to reproduce. Indeed, the structure of the device itself (a large number of components), the interactions and the mechanical and thermic tolerance of the different components and the way it has been designed make the application of cryogenic fluid difficult to reproduce. Indeed, these applications give rise to significant variations in the local instantaneous temperature of the areas treated from one trial to the next due to this lack of reproducibility and do not provide the safety and efficacy expected of this type of device because of the major risk of burns and extensive necrosis.
[0023] Moreover, the implementation of prior art devices produces a non-selective cell lysis effect, that is, they produce necrosis of the entire cell population of the tissue of the treated areas, and this is undifferentiated on all cell populations (melanocytes, keratinocytes, fibroblasts, etc.). Indeed, their intrinsic nature or operating mechanisms and implementation do not enable the precise management or control of the dose delivered and the length of application of the cryogenic fluid on a given area or, as a consequent, the level of the desired temperature over the entire treated area. Since the range of temperatures actually applied on the tissue is extensive, this method does not provide a cryo-cyto-selective action on the cell populations present. However, a cryo-selective action is the ability to act specifically on a given population of cells (for example, only melanocytes), without acting on other cell populations. Therefore, the devices in the prior art do not act only on one cell population (for example melanocytes). This requires a very precise control of the temperature applied on the cells and not only at the lowest possible temperature obtained but also on the kinetics of the temperature variation. Indeed, since certain cell populations react differently to cold than others, by applying cold within a certain temperature range and according to a certain kinetics, it is then possible to act specifically on a given population of cells by provoking their lysis, without affecting other populations. The application of cold to obtain a cyto-selective effect is called cryo-cyto-selective action or cryo-cyto-selectivity.
[0024] Until now, the skilled person only looked for undifferentiated local cell necrosis since they only took into account the length of time, as they were not familiar with cryo-cyto-selectivity. As a result, the skilled person did not think and could not imagine means to obtain a cyto-selective cryogenic action for a cosmetic treatment. In addition, devices were not available for out-patient use, were not simple or fast to implement and allow for very precise automated control of the optimum temperature that was sufficient to reach the target area.
[0025] Moreover, the known traditional cryogenic devices experience problems of icing and clogging due to the sudden freezing of the water vapour present in the immediate vicinity of the nozzle when the cryogenic fluid is triggered. These problems are exacerbated by the nature of the non-hydrophobic materials used until now for the nozzle.
[0026] This phenomenon is especially of concern because the nozzle whose diameter must be very small over a considerable length is generally made of metal, for reasons of mechanical strength.
[0027] As a result, the nozzle of current cryogenic devices enabling the timing of the flow of fluid is the seat of physical phenomena of retention and conduction of the upstream cold that disrupt the operation of the means of delay, whether mechanical (springs, cams, etc.) or electronic (solenoid valve, etc.) because they are all very sensitive to low temperatures.
[0028] In addition, the skilled person is faced with technical issues of regulating the power and extent of the coolant fluid. Indeed, when they use a pressurised container, they have to trigger a lever to open or close a valve that determines the output of the coolant. The time of application is extremely variable from one spray to the next and, as a result, the dose of cold delivered cannot be controlled. Finally, a screw on the nozzle to alter the flow does not, after a change, allow the position of the earlier flow to be found.
[0029] These problems have a very significant impact on the distribution of the cryogenic fluid and, as a result, on the temperature kinetics obtained on the treated tissue. It is not possible today, with existing devices, to produce only cosmetic effects by selective cyto-cryogenics.
PRESENTATION OF THE INVENTION
[0030] In view of the techniques and products currently used, the invention aims at solving the technical problems raised by the prior art by providing:
the total elimination of dark spots and not by reducing their colour, obtaining an immediate effect, eliminating dark spots with one application obtaining the expected results without creating marks on the skin, without causing pain and redness during and after the application of the cold, eliminating all risks of frost and/or conduction of cold by the nozzle to avoid any disturbance of the system of electronic or mechanical timing of the cryogenic device, limiting and controlling the flow of coolant, perfectly mastering the temperature level to achieve and maintain at the surface of the skin over a given time (temperature kinetics), allowing easy and fast use of the device.
[0038] For this purpose, the invention provides a cosmetic treatment method according to claim 1 .
[0039] The treatment according to the invention generates a cyto-selective action through appropriate cryogenics. In the context of the invention, the term selective cyto-cryogenic action or cryo-cyto-selectivity refers to the fact of acting selectively by means of a cooling agent on a population of cells of a tissue considered, without affecting other cell populations. The cosmetic treatment method according to the invention acts only by a controlled level of cold, on melanocytes located between the stratum corneum and the basal level (dermal-epidermal junction), in the epidermis. With the stratum corneum, the epidermis is the most superficial part of the skin. Thus, this superficial action occurs without destroying the keratinocytes.
[0040] The invention provides a cyto-selective cryogenic device for the implementation of this method according to claim 10 .
[0041] Ways to carry out this method and the device in the invention are defined by the other claims.
BRIEF DESCRIPTION OF THE FIGURES
[0042] Other characteristics and advantages of the invention will emerge on reading the description that follows, with reference to the accompanying figures, which illustrate:
[0043] FIG. 1 is a schematic view in longitudinal section of an embodiment of the cyto-selective cryogenic device according to the invention;
[0044] FIG. 2 is an experimental curve showing the thermal effect obtained with the device according to FIG. 1 ;
[0045] FIG. 3 is a longitudinal section view of an alternative embodiment of the cyto-selective cryogenic device according to the invention;
[0046] FIGS. 4A, 4B and 4C represent sectional detailed views of three variants of improved nozzles that may be used in the device of the invention;
[0047] FIG. 5 shows a detailed view in longitudinal section of a variant of the nozzle used in the device in FIG. 3 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0048] Cryotherapy is a method that is considered to be painful in 64% of the patients treated when the cold is applied for over 10 seconds. If the cold is applied for under 10 seconds, 44% of the patients do not perceive any pain. The lower the time of application, the lower the pain. However, a low exposure to cold considerably reduces the efficacy of the treatment since, in such a case, only 30% of the patients are cured. It is clear that the time of cold application has a direct impact on the efficacy of the treatment and the intensity of the pain experienced.
[0049] The cooling of tissue leads to changes in the physical state and, according to the conditions for the application of the cold, its preservation or, on the contrary, its alteration. The thermal shock applied in the context of the invention is a highly considerable reduction in the temperature in a minimum of time. The procedure is implemented by very rapid freezing, followed by slow warming in which the action of the cold persists. The very sudden reduction in the temperature induces, even before the tissue is solidified, the micro-crystallisation of the intracellular water. These microcrystals induce membrane alterations, denaturation of structural proteins and enzymes, excessive concentration of ions, all conditions resulting in an adverse effect on the cells. Recrystallisation of the excess water during the heating phase further increases cell lysis. In normal conditions, the skin temperature is about 34° C. This is the temperature that must be lowed to the maximum in a minimum time.
[0050] The melanocytes are located at the dermo-epidermal junction and migrate during the fours stages of their maturation to the surface of the skin, that is, to the superficial layer of the epidermis. These melanocytes contain melanosomes, vesicles containing melanin. The maturation of the melanosomes and the melanin concentration occurs within the melanocytes. The melanosomes are then transferred to the dendrites of the melanocytes and to the keratinocytes, which integrate them in their cell structures. They place themselves above the nucleus to protect it from UV radiation. Enzymes then break down the melanosomes. The released melanin is eliminated at the epidermal surface by desquamation of the stratum corneum and in the dermis by the lymphatic route.
[0051] Hyperpigmentation results from a melanogenesis disorder, with increased activity in the melanosomes and sometimes the more extensive transfer of pigment in the keratinocytes of the stratum spinosum, or an accumulation of melanin in the dermis. It thereby consists of a hypermelanocytose, located at the basal level. The hypermelanocytose is characterised by the increase in the number of melanocytes, or an increase in the melanin synthesis by the melanocytes. The key cell and, consequently, the target cell is the melanocyte. However, the keratinocytes should not be affected since they protect the epidermal tissue from UV radiation.
[0052] The thickness of the epidermis varies according to the area concerned, from 0.02 mm on the facial skin to 0.5 mm on the soles of the feet. Its average thickness is 0.01 mm. On the hands (top of the hands), the melanocytes are located 0.1 mm from the surface of the skin.
[0053] In an epidermis subjected to cold, the melanocytes remain viable if they are subjected to a temperature between 0 and −4° C.
[0054] Between −4° C. and −7° C., granuloma lysis containing pigments is observed, that is, the melanosomes containing melanin, followed by the beginning enzyme digestion of the melanin in the melanocytes and in the keratinocytes in the deep layer of the epidermis, near the basal layer.
[0055] Between −7° C. and −30° C., the disappearance of the melanocytes is observed and, below, the melanocytes do not reappear (depigmentation disorder). The destruction of keratinocytes occurs at temperature below −20° C., with a very significant destruction of highly differentiated melanocyte populations.
[0056] The invention has shown that the efficacy of the cosmetic treatment of hyperpigmentation due to melanocytes, without significant damage to the keratinocytes, occurs at a range of −4° C. and −15° C. and preferably between −5° C. and −12° C. The cold applied to the skin should generate a temperature preferably between −5° C. and −12° C. for 2 to 10 seconds, to act on the melanocytes and the melanin cyto-selectively. Therefore, the application of a fluid at a temperature between −5° C. and −12° C. for a period of 2 to 10 seconds, acts on the melanin and the melanocytes, without damaging the keratinocytes, according to a principle of cyto-selectivity, that is, a cell selectivity by cryogenics. The balance between the benefits (action on the melanin and melanocytes between −5° C. and −12° C.) and the risks (destruction of the keratinocytes below −20° C.) is therefore high and, according to the invention, is consistent with high safety with the use of the cosmetic treatment and the absence of adverse effects (pain and scars).
[0057] The water condensation properties of certain cooling fluids are more pronounced than others. This is the case of dimethyl ether, a cryogenic fluid used in certain products to treat warts. When this mixture enters a foam tip, the water vapour in the air condenses due to the contact of the cold foam with the surrounding air. Systematically, the formation of droplets can be observed. They immediately freeze on the surface of the nozzle when the latter is held in the open air. This fluid remains longer in liquid form on the skin. It evaporates slowly, trapped in the tip. When this nozzle is applied to the skin, a certain amount of water is deposited on the treated area and this moisture greatly heightens the sensation of pain. However, difluoroethane (code 152A) evaporates very quickly, allowing the cold to penetrate more quickly into the skin. The speed of evaporation and spray without direct skin contact avoids the condensation of water and its “imprisonment”. Difluoroethane (152A) has been selected for its boiling point at −25° C., its vapour pressure of 5.3 bars at 20° C., and its low latent heat of evaporation (160 KJ/kg), to produce a highly volatile fluid to prevent the formation of drops on the skin and, as a result, the sensation of pain while providing enough cold to be effective.
[0058] When the skin is subject to a source of cold applied on its surface, it undergoes a rapid lowering of its temperature. In this case, the application of a stream of difluoroethane without direct contact on the skin produces a variation in the surface temperature of about 10 to 20° C. per second. It thereby helps reduce the temperature of the tissue from about 34° C. to −5° C. to −12° C., a difference of about 40° C., within a little more than 2 seconds and, in practice, from 2.5 to 3 seconds, due to thermal loss. An alternative embodiment of the invention uses gas 134A, that is, tetrafluoroethane.
[0059] The change in temperature progresses at a rate of 0.5 to 1 mm per second through the layers of the skin.
[0060] As a result, the temperature of the basal layer generated by the cold equals the temperature at the surface of the skin in a time interval of about 0.2 seconds.
[0061] In these conditions, in less than 1 second, the temperature of the melanocytes in the basal layer is identical to that of the skin surface. A spraying time of the cryogenic fluid of about 3 seconds is thereby optimal for the desired effect.
[0062] In a preferred embodiment, the method is implemented using a direction difluoroethane (152A) diffuser with automated timing system, pre-set at three seconds. The main components are described below.
[0063] As shown in FIGS. 1 and 3 , the components of the device are surrounded by casing 1 . This casing contains a cartridge 2 of cryogenic fluid, preferably 152A, possibly 134A (tetrafluoroethane) under a pressure of about 6 bars and a maximum of 10 bars. Cartridge 2 is connected to solenoid valve 7 via a stem 8 allowing the fluid to escape from the interior of the cartridge outwards. When the device is in rest position, stem 8 lets the fluid enter the upstream chamber of solenoid valve 7 . Casing 1 contains a power source, for example, in the form of electric batteries 3 . The power source is connected via a switch 5 to an electronic timing system 4 , which allows for the passage of fluid in solenoid valve 7 for a pre-determined time. The electronic timer 4 , and consequently solenoid valve 7 is triggered by a release button 6 . Downstream from solenoid valve 7 , a nozzle 9 is arranged. This is presented diagrammatically according to two variants in FIGS. 1 and 3 . This unit allows provides a precise and reproducible dose of cryogenic fluid being ejected via the nozzle for a pre-determined time, for example three seconds, with an accuracy of 0.1 seconds. The precision of the timing of the solenoid valve is required to secure a selective cryo-cyto action thereby avoiding reaching temperatures that are harmful for the keratinocytes.
[0064] Preferably, the end of the stem 8 , which is engaged inside the cartridge 2 , is equipped with a coaxial socket (not shown) containing longitudinal peripheral slots allowing for the passage of the cryogenic fluid under pressure.
[0065] These slots are designed to let the fluid pass through when the device is oriented vertically with cartridge 2 in the up position (head down).
[0066] This configuration prevents the use of the device in other positions for safety reasons. It also optimises the ease of handling of the device on the dark spots of the hand by a diffusion from top down, only using the other hand, without the help of a third person.
[0067] The nozzle 9 opens into a nozzle 10 arranged outside the casing 1 . Nozzle 10 , which is conical in the embodiment shown in FIG. 1 , terminates with a connector 11 with an opening allowing for the contact between the stream of cold fluid (in gas state) and the targeted skin area. The aperture may thereby have an area corresponding to the diameter of the most extensive lentigines that can be treated in a cosmetic procedure without the risk of confusion with a possible melanoma. The aperture may, for example, have a circular shape with a diameter of 6 mm. Therefore, a skin spot may be treated with a single application. The conical shape of the nozzle, its length of about 35 mm, the lateral openings and the tip are designed to focus the diffusion of the fluid on a specific area of tissue.
[0068] In the embodiment presented in FIG. 1 , the cryogenic fluid passes successively from cartridge 2 and stem 8 , where the outlet diameter may vary from 3 to 4 mm, to the solenoid valve 7 , whose input and output diameters may vary from 0.15 mm to 0.25 mm. The cryogenic fluid passes into a chamber of the solenoid valve 7 along a length, which may range from 10 to 30 mm.
[0069] At the outlet of the solenoid valve, it enters through an opening in the nozzle 9 , in which the length of the path of the fluid ranges from 3 to 12 mm, with an inner diameter of 0.15 to 3.5 mm and which may be composed of the assembly of one or several identical components of hydrophobic material and without or with a very low thermal conductivity.
[0070] This nozzle consists of an element that is long and especially narrow in which the fluid flows before it is ejected and its expansion to atmospheric pressure or to the area adjacent to the area of skin to be treated. Precisely this expansion is the endothermic phenomenon producing the cryogenic effect.
[0071] The nozzle helps reduce the initial speed of the cryogenic fluid and promotes the projection of the cold liquid sprayed on an area of skin in appropriate conditions of temperature and time set by the cosmetic care provided by the invention.
[0072] In the context of the invention, changes in the diameter, length and shape of the nozzle 9 have been found to considerably influence the flow of the gas and these modifications pay a major role, in combination with adjustments to the opening time of the solenoid valve 7 , on the temperature at the surface of the affected skin area.
[0073] In particular, and according to a particularly preferred embodiment, a nozzle in which the path length of the fluid ranges from 3 to 12 mm for a inner diameter of passage of 0.15 to 3.5 mm, in combination with a time of opening of the solenoid valve of three seconds, provides a temperature range leading to an effective cryo-cyto-selective action on the treated area of tissue.
[0074] FIG. 2 illustrates the above by showing the temperature of the skin surface obtained after three seconds of opening of the solenoid valve with (A) and without (B) the nozzle 9 of the invention. The absence of nozzle does not provide the temperature range for a cryo-cyto-selective action since a temperature would be obtained that is harmful for the keratinocytes.
[0075] In addition, in order to avoid, on the one hand, icing phenomena and protect the means for the delivery of fluid and, in particular, insulate the electronic or mechanical components of the timing system of the solenoid valve from low temperatures and limit, on the other hand, the power of the flow, the invention defines a specific nozzle to increase the resistance to the flow of the cryogenic fluid downstream from the solenoid valve 7 .
[0076] FIGS. 4A to 4C present variations of an improved nozzle according to the invention.
[0077] The nozzle 9 shown in FIG. 4A comprises a one-piece cylindrical body 91 on the upper side of which an upstream circular cavity 91 a is formed. The height of the body 91 here is between 4 and 12 mm and, preferably, 10.50 mm, and it has an outer diameter of about 12 cm while the cavity 91 a has a small depth (about 0.40 mm) and an inner diameter of about 8 mm.
[0078] This cavity is made to receive an annular seal (such as J 1 in FIG. 5 ) whose thickness roughly corresponds to the depth of the cavity 91 a.
[0079] The cavity 91 a extends downstream and within the body via an also cylindrical axial conduit 91 b for the passage of fluid whose inner diameter is 3.5 mm here and whose length is between 8 and 9 mm.
[0080] In view of the relative dimensions, the conduit 91 b forms a chamber for the transient retention and accumulation of fluid thereby ensuring, the slowing down of the flow. The fluid is then ejected downward and outward towards the skin area to be treated, successively, through an axial channel 91 c of very small diameter (between 0.15 and 0.25 mm) with respect to that of conduit 91 b and then the nozzle 10 , whose length is preferably from 0.3 to 2.4 mm.
[0081] In conduit 91 b , the stream of fluid leaving the solenoid valve 7 is at least partially liquid because the expansion is still only partial and it is subject to turbulence resulting from the impact of the stream of fluid released and sprayed from the solenoid valve 7 against the walls of the conduit. This regime of turbulence also helps slow down the flow of fluid.
[0082] Another variant of the nozzle in the invention is illustrated by FIG. 4B in connection with FIG. 5 .
[0083] The cavity 92 a , like cavity 91 b , is made to receive an annular seal (refer to J 1 , J 2 in FIG. 5 ) whose thickness substantially corresponds to the depth of this cavity.
[0084] However, unlike the conduit 91 b of FIG. 4A , the axial conduit 92 b is conical with an upstream inlet diameter between 2 and 3 mm for a length between 3 and 5 mm.
[0085] The conduit 92 b extends by an axial channel 92 c of very small diameter (between 0.15 and 0.25 mm) and very short length (between 0.3 and 2.4 mm and, preferably, 0.5 mm) that opens to the outside down the centre of an inside coaxial cavity 92 d that is identical to the upper cavity 92 a and is made to also receive an identical annular seal (refer to FIG. 5 ).
[0086] FIG. 4 c shows yet another variant of the nozzle 9 of the invention where the inner axial conduit 93 b is frusto-conical with an inlet diameter upstream between 2.0 and 3.0 mm and an inside diameter in the lower part between 1.0 and 2.0 mm.
[0087] The conduit 93 b opens into the lower cavity 93 d via a channel 93 c identical to channel 92 c of FIG. 4B .
[0088] To ensure a better thermal insulation of the solenoid valve 7 and, in particular, the electronic or mechanical system providing the time delay, with respect to the low temperatures of the fluid immediately entering downstream in the nozzle 9 , according to the invention, it is envisaged to make the body of the nozzle out of a hydrophobic material and without or with very low thermal conductivity such as PTFE, PFA, POM or a POM+PTFE mixture. Indeed, these materials do not retain drops of water (neither by absorption, nor adsorption) and thereby eliminate the risk of icing of the nozzle.
[0089] Moreover, since these materials are thermally insulating, they protect the timing system, whether electronic or mechanical, avoiding malfunction.
[0090] Advantageously, the nozzle body may be created by moulding the hydrophobic and thermally non-conductive plastic.
[0091] FIG. 5 presents a variant of the nozzle of the invention made by the assembly and connection in series of two identical bodies 92 as shown in FIG. 4B .
[0092] However, it would be possible, without departing from the scope of the invention, to provide the assembly and fluid connection of two bodies of different dimensions and profile, in particular, according to variants illustrated by FIGS. 4A to 4C .
[0093] Each of the two bodies 92 , as illustrated in FIG. 4B , is cylindrical and has a circular upstream cavity 92 a like the cavity 91 a in FIG. 4A in which at least one annular seal J 1 , J 2 is housed.
[0094] The diameter of the two bodies 92 is about 12 mm like the body 91 in FIG. 4A and their respective height is between 4.5 and 5.5 mm.
[0095] The two bodies 92 are assembled against each other in a stacked and coaxial manner overwhelming the joints J, respectively, upper J 1 and intermediate J 2 , inside the upstream compartment 12 a of a casing 12 whose dimensions are designed for this purpose.
[0096] The in series connection of the conduits 92 b , 92 c of at least two bodies 92 of nozzle 9 downstream from the solenoid valve 7 limits and/or slows down the flow of cryogenic fluid, thereby at the same time avoiding an overly sudden expansion which is likely to cause icing and a low temperature on the skin application area.
[0097] According to a preferred embodiment, the diameter of conduit 92 c is 0.17 mm over a height between 0.5 and 0.9 mm and preferably 0.5 mm.
[0098] Preferably, the casing 12 will be made in one piece with the housing 1 ( FIGS. 1 and 3 ) and is connected via a downstream compartment 12 b made in the lower part, to the nozzle 10 communicating with the end-piece 11 forming a collimator.
[0099] FIGS. 3 and 5 illustrate a method of connection of the nozzle 10 and tip 11 to the casing 12 of the nozzle 9 .
[0100] According to one variant, it would be possible to provide a releasable connection (for example, by bayonet) and/or adjustable in height (for example, by screwing) of the nozzle 10 on the casing 12 so as to adjust the position of the tip and the cryogenic fluid concentration over the target area to be treated.
[0101] In the variant shown in FIG. 3 , the end-piece 11 is designed as a perforated shell with a central opening 11 a for the focused application of the fluid on the skin area.
[0102] The lateral wall of this shell is perforated and its periphery is snapped over the peripheral edge of the lower part of the nozzle 10 .
[0103] The invention will be described in further detail in the following example for the implementation of the method of treatment.
[0104] Example of the Implementation of the Method of Cosmetic Treatment in the Invention by Cyto-Selective Cryogenics.
[0105] A study was carried out to validate the device described above. The study consisted of applying a cryogenic gas 152A on subjects with dark spots on the back of the hand. The study included 4 subjects, two men and two women, JMPAT, CDEN, AMAH and YPHIL, 50, 57, 59 and 55 years old respectively. The duration of the application of the cryogenic gas was set at 3 seconds. The subjects had the following characteristics:
JMPAT: presence of a very visible dark spot on the right hand, near the index. CDEN: presence of a visible dark spot on the right hand, between the index and the little finger. AMAH: presence of two large dark spots, on the right hand. YPHIL: presence of two dark spots, almost touching, on the right hand.
[0110] The results show that the device eliminates dark spots after one spray of 3 seconds per spot. Indeed, the treated dark spots totally disappeared in all of the patients after a period of two to three weeks after a single application. Some of the subjects enrolled in the study were already treated by a dermatologist on other similar dark spots on the back of their hand. The treatment consisted of the application of traditional cryotherapy with nitrogen or dimethyl ether.
[0111] Unlike these treatments, the surface application of cryogenic cold with the device in the invention did not induce a sensation of pain, even though the subjects felt sharp pain during the previous treatment by the dermatologist. In addition, the absence of major inflammation and tissue destruction likely to lead to marks in the form of scars or hypo-pigmentation is noted.
[0112] These observations confirm that the device really provides a cryo-cyto-selective cosmetic effect, while traditional cryotherapy with nitrogen or dimethyl ether, as carried out under medical supervision in the office of a dermatologist, did not provide such an effect. The device with its cryo-cyto-selective action does not provoke destruction by necrosis of all of the tissue, or the destruction of keratinocytes and therefore does not provoke the phenomena observed with traditional cryotherapy with nitrogen as performed in the office of a dermatologist (inflammation, severe pain, scarring, hypo-pigmentation).
[0113] Although presented in FIG. 1 in the form of an elongate diffuser designed to contain a cartridge of difluoroethane, the invention may apply to any cryogenic fluid diffuser having a boiling temperature between −20° C. and −65° C. and a latent heat evaporation between 1 and 500 KJ/Kg, equipped with a suitable focusing device on an area of skin and a pre-set or adjustable system of timing control.
[0114] As described above, the invention provides a method for the cosmetic treatment of skin tissue to obtain a cryo-cyto-selective action on melanocytes versus keratinocytes. As already noted above, the term cryo-cyto-selective action or cryo-cyto-selectivity refers to a selective action on a population of cells of a certain tissue without acting on at least one other or other populations of cells.
[0115] The invention may be applied to other types of populations of cells in other tissues. The term population of cells is understood in its broadest sense, that is, a set of cells having the same characteristics, for example, a type of cell, a cell line, stem cells, prokaryotes or eukaryotes, of all origins, human, animal or plant.
[0116] In addition, the method in the invention may also apply to the components of cells, that is, cell organelles, including but not limited to melanosomes, nucleoli, nuclei, ribosomes, vesicles, endoplasmic reticuli, Golgi, cytoskeletons, mitochondria, vacuoles, cytosols, lysosomes, centrosomes and plasma membranes. The method in the invention as described above may also apply, provided that it is possible to determine a deleterious temperature range for the cell population, structures or target organisms, and in which range another population or surrounding tissue is not affected in a noteworthy or unacceptable manner. | The invention relates to a method for cosmetically treating dark spots on the skin, wherein said method is intended for eliminating at least one of said dark spots located in a region of the hand, the face, the limbs or the chest area of a person suffering from such skin hyperpigmentation, characterised in that said method includes a step of applying a spray of cryogenic fluid to said region, which brings the skin temperature to a temperature of between −4° C. and −15° C. for a consecutive application period of from 2 to 10 seconds, in order to selectively act on the melanocytes, and to a device for carrying out said method. | 0 |
FIELD OF THE INVENTION
The present invention relates generally to railroad tank cars used to carry liquids and gases, including hazardous and flammable liquids and gases. More specifically, the present invention relates to a method of forming “2:1” ellipsoidal heads for cylindrical tanks of railroad tank cars from steel, and to railroad car tank heads made by such method. A “2:1” ellipsoidal head is shaped as an ellipsoid of revolution in which the major axis equals the diameter of the tank shell adjacent the head and the minor axis equals one-half the major axis.
BACKGROUND OF THE INVENTION
Material properties and specifications associated with tank heads used on rail tank cars are directed by the Association of American Railroads (“AAR”) under AAR Specification M-1002 entitled “AAR Manual of Standards and Recommended Practices, Section C-Part III, Specification for Tank Cars.” AAR Specification M-1002 is governed by DOT 173.31(f), which states:
(f) Special requirements for hazardous substances. (1) A tank car used for a hazardous substance listed in paragraph (f)(2) of this section must have a tank test pressure of at least 13.8 Bar (200 psig), head protection and a metal jacket, except that— (i) No metal jacket is required if—
(A) The tank test pressure is 23.4 Bar (340 psig) or higher; or (B) The tank shell and heads are manufactured from AAR steel specification TC-128, normalized; . . . .
AAR Specification M-1002 is also governed by DOT 179.100-8(b), which states: “Each tank head made from steel which is required to be ‘fine grain’ by the material specification, which is hot formed at a temperature exceeding 1700° F., must be normalized after forming by heating to a temperature between 1550° and 1700° F., by holding at that temperature for at least 1 hour per inch of thickness (30-minute minimum), and then by cooling in air.” The purpose of the normalizing heat treat practice is to ensure that the tank head has the impact toughness properties addressed in AAR M-1002, section 2.2.1.2, which requires:
Effective for cars ordered after Aug. 1, 2005, each plate-as-rolled of ASTM A516, A302, A537, and AAR TC128 steel used for pressure tank car heads and shells must be Charpy impact tested transverse to the rolling direction in accordance with ASTM A20. The test coupon must simulate the in-service condition of the material and must meet the minimum requirement of 15 ft-lb average for three specimens, with no single value below 10 ft-lb and no two below 15 ft-lb at −30° F. Plates for low temperature service described in 49 CFR 179.102 that require longitudinal impact testing at −50° F. do not require transverse testing at −30° F.
As is clear from DOT 179.100-8(b), it is industry practice to hot form railroad car tank heads. Hot forming typically involves heating a circular steel plate blank in an oven which may be above the normalization temperature, and pressing the hot steel blank in a hydraulically powered press to form an ellipsoidal tank head. This process is expensive in terms of equipment and is time consuming. The AAR standards do not contemplate or address tank car heads fabricated through a cold forming process and then heat treated after cold forming.
The impact toughness of tank heads for rail cars is of vital importance, as demonstrated by recent tragic accidents in Lac-Megantic, Quebec and Casselton, N. Dak. Lac-Megantic was the site of a train derailment in July of 2013 that killed forty-seven people. In that incident, a freight train with seventy-two tank cars filled with crude oil ran away and derailed, resulting in the fire and explosion of multiple tank cars near the town's center. In addition to the casualties, more than thirty buildings were destroyed. Just outside of Casselton, a train carrying crude oil struck wreckage from a prior derailment on Dec. 30, 2013, igniting the crude oil and causing a chain of large explosions which were heard and felt several miles away. Authorities issued a voluntary evacuation of the city and surrounding area as a precaution. The crash occurred in proximity to a populated area, and it was fortunate that no casualties resulted.
Prior methods of cold-forming tank car heads have involved a one stage cold-forming step wherein a high-force hydraulic press (e.g. a 12,000 ton hydraulic press) is operated to cold-form a steel blank into an ellipsoidal tank head by one pressure stroke or a few pressure strokes. These methods were attempted in the 1960s and earlier.
One drawback of early cold-forming approaches is that the equipment was limited to a single tank car head size specification. In order to adapt the forming equipment to manufacture a variety of tank car head sizes, a corresponding variety of dies had to be provided at high expense. Changing the set-up of the press equipment from one tank head size to another added further time and expense.
More importantly, the use of brute force to cold-form a tank car head in a very short period of time may cause material damage and introduce significant stresses in the material. Where the steel blank is over ⅜ of an inch thick, finite cracks are highly suspect in rapid cold-forming operations. Thus, rapidly cold-formed tank car heads have in the past required very careful and time-consuming inspection.
It is believed that the equipment requirements, inspection demands and quality concerns associated with rapid single stage cold-forming methods of the prior art have more than negated the benefits of faster production, thereby leading to the current acceptance of hot-forming as the industry standard for tank car head production.
Thus, there has long been a need for an improved cold-forming process for making tank car heads that avoids the drawbacks of earlier cold-forming processes. The need for an improved manufacturing process has grown urgent in view of safety concerns raised by recent accidents, including the highly publicized accidents in Lac-Mégantic and near Casselton.
SUMMARY OF THE INVENTION
The invention provides a new method of manufacturing a railroad car tank head. The method departs from prior art methodologies by adopting a two-stage cold-forming process instead of hot-forming or one-stage cold forming. In some embodiments, the method further departs from prior art methodologies by using a stress relieve heat treatment instead of a higher-temperature normalizing heat treatment.
The method of the invention generally comprises the steps of providing a circular blank of steel plate material, cold-forming the circular blank to form an intermediate ellipsoidal dish (the first cold-forming stage), cold-forming a peripheral flange region of the intermediate ellipsoidal dish to form a flanged ellipsoidal dish (the second cold-forming stage), and then heat treating the flanged ellipsoidal dish. In one embodiment, heat treating includes thermally stress relieving the flanged ellipsoidal dish by heat treating the flanged ellipsoidal dish at a temperature below the normalization temperature of the steel plate material. In another embodiment, heat treating the flanged ellipsoidal dish includes a normalizing heat treatment. The two cold-forming steps or stages may be carried out at room temperature.
The circular blank may be cut from ASTM TC128, Grade B, normalized steel plate material. The circular blank may be cold-formed using an automatic dishing press system. In one embodiment, a plurality of circular blanks are cold-formed simultaneously in a dishing press system. The intermediate ellipsoidal dish created by the dishing press system may be cold-formed in a flanging machine to provide a flanged ellipsoidal dish. The temperature of the steel may be monitored during cold-forming to prevent material heating and possible unexpected material deformation associated therewith. Where the heat treatment includes thermally stress relieving the flanged ellipsoidal dish, the dish may be held at a temperature at or just above 1100° F. (e.g. 1150° F.) for a period of time ranging from one hour up to four hours, and then cooled in a controlled manner. The dish may be stress relieved before it is welded onto the cylindrical tank, and/or after it is welded onto the cylindrical tank. Where the heat treatment includes normalizing the flanged ellipsoidal dish, the flanged dish may be held at approximately 1700° F. for more than one-half hour but less than one hour.
The present invention provides a method of making a railroad car tank head that is more efficient than prior methods, avoids the challenges of hot-forming, is easily adaptable to different tank head diameters using the same forming equipment, and aims to yield a railroad car tank head that meets safety standards.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:
FIG. 1 a flow diagram generally illustrating a process for manufacturing railroad car tank heads in accordance with an embodiment of the present invention;
FIG. 2 is a plan view of a circular blank cut from steel plate in accordance with the process of FIG. 1 ;
FIG. 3 is a cross-sectional view of the circular blank shown in FIG. 2 ;
FIG. 4 is a schematic orthogonal view of an automatic dishing press system used in a first cold-forming stage of the process, wherein a circular blank is shown transparently;
FIG. 5 is a side view of an intermediate ellipsoidal dish formed from the circular blank in accordance with the first cold-forming stage;
FIG. 6 is a schematic side view of a flanging machine used in a second cold-forming stage of the process;
FIG. 7 is a side view of a flanged ellipsoidal dish formed from the intermediate ellipsoidal dish in accordance with the second cold-forming stage;
FIG. 8 is an orthogonal view of the flanged ellipsoidal dish shown in FIG. 7 ; and
FIG. 9 is a graph illustrating Charpy impact test results for seven specimens heat treated according to various protocols.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 generally illustrates a method 10 of manufacturing an ellipsoidal head for a railroad tank car in accordance with an embodiment of the present invention. The method described herein may be used to produce tank car heads for DOT/TC Pressure Cars (Class DOT/TC-105, 112, 114 &120 tank cars). Heads for these tank car classifications are currently produced using a hot forming and normalizing process described above in the Background of the Invention section.
As an initial step indicated at block 12 , a circular blank of steel plate material is provided. The circular blank, shown in FIGS. 2 and 3 and identified by reference numeral 30 , may be cut from flat plate stock material using a plasma cutter, laser cutter, or other steel cutting technology. Circular blank 30 may be cut from ASTM TC128, Grade B, normalized steel plate, a grade intended for usage in railroad tank car fabrication (this is the only grade approved in North America and Europe for usage in railroad tank car fabrication). Steel plate used by applicant in manufacturing prototype tank car heads for testing the inventive method had a Minimum Tensile Strength, Welded Condition, of 81,000 psi (560 MPa) and a Minimum Elongation in 2″ Weld Material of 19%. The thickness of circular blank should be at least ½ inch, but is preferably slightly greater than ½ inch, for example 9/16 inch, to ensure that no portion of the tank car head is less than ½ inch thick after forming due to thickness reduction that occurs during forming. The diameter of the circular blank is chosen depending upon the specified outer diameter of the finished tank car head. By way of non-limiting example, where the outer diameter of the tank car head is specified to be 123.5 inches, the diameter of circular blank 30 may be 148 inches.
Returning to FIG. 1 , circular blank 30 is cold-formed in a two-stage cold-forming process represented by blocks 14 and 16 . The first stage, represented by block 14 , is cold-forming the circular blank to form an intermediate ellipsoidal dish. The term “intermediate” is used to indicate that the ellipsoidal dish is not in final form for use as a tank car head. The term “cold-forming” means that the temperature of the steel material is not greater than 200° F. during the forming process. The first stage of cold-forming may be performed by an automatic dishing press system, illustrated schematically in FIG. 4 and identified generally by reference numeral 32 . Automatic dishing press system 32 includes a press die 34 and an opposing fixed die 36 . Press die 34 is mounted at the end of a cylinder actuator 38 . Actuator 38 may be hydraulically powered and is controllable to raise and lower press die 34 for selectively applying pressure to circular blank 30 along a pressure axis 40 . Automatic dishing press system 32 also includes an automatic manipulator 42 for moving circular blank 30 relative to pressure axis 40 . The first stage of cold-forming the circular blank 30 includes repeatedly positioning the circular blank relative to the pressure axis and applying pressure to different localized regions of the circular blank. The operator of automatic dishing press system 32 may manually input control commands to control the pressure strokes of press die 34 and the positioning movements of circular blank 30 to gradually cold-form the circular blank into an intermediate ellipsoidal dish 50 , depicted in FIG. 5 . Intermediate ellipsoidal dish 50 may be cold-formed by forming circular blank 30 to provide a primary dish radius DR that is 90% in length relative to the intended outer diameter OD of the completed tank head. Automatic dishing press system 32 is preferably a CNC machine tool capable of recording the commands inputted by the operator, whereby an automatic program may be created and stored to eliminate the need for manual input of commands when running subsequent tank car heads of the same size and material. By way of non-limiting example, automatic dishing press system may include a Series PPM-600/5 Hydraulic Dishing Press and a Model MA-80 Automatic Manipulator for Dishing Press available from Faccin USA, Inc. of South Tampa, Fla. and Italy.
Applicant has experimented with stacking two circular blanks 30 on an automatic dishing press and cold-forming two intermediate ellipsoidal dishes simultaneously. This procedure was successful in producing two intermediate ellipsoidal dishes 50 in approximately half the time it takes to produce a single intermediate ellipsoidal dish 50 when only one circular blank 30 is loaded in the automatic dishing press.
The second cold-forming stage, represented by block 16 , is cold-forming a peripheral flange region of the intermediate ellipsoidal dish 50 to form a flanged ellipsoidal dish 70 . The second stage of cold-forming may be performed by an automatic flanging machine, illustrated schematically in FIG. 6 and identified generally by reference numeral 52 . Automatic flanging machine 52 includes a clamping axle 54 A, 54 B operable to clamp intermediate ellipsoidal dish 50 at its center and define an axis of rotation 56 about which intermediate ellipsoidal dish 50 is rotated in spinning fashion. Flanging machine 52 further includes a flanging roll 58 operable to engage an outer surface of intermediate ellipsoidal dish 50 near its rim, and a shaping roll 60 operable to engage an inner surface of intermediate ellipsoidal dish 50 . Flanging roll 58 is horizontally and vertically positionable relative to dish 50 , and has an axis of rotation that is tiltable in a vertical plane. Likewise, shaping roll 60 is horizontally and vertically positionable relative to dish 50 , and has an axis of rotation that is tiltable in a vertical plane. Flanging machine 52 may also include guide rolls (not shown) operable to engage the underside of intermediate ellipsoidal dish 50 as it rotates about axis 56 . As will be understood, as intermediate ellipsoidal dish 50 is rotated, flanging roll 58 may be positioned and its tilt angle may be adjusted as it engages the dish to alter the profile of the dish. The position and tilt angle of shaping roll 60 may also be adjusted as shaping roll engages dish 50 to assist in gradually altering the profile of dish 50 in a controlled manner. In this way, intermediate ellipsoidal dish 50 is cold-formed into a flanged ellipsoidal dish 70 as illustrated in FIG. 7 . Flanged ellipsoidal dish 70 a secondary knuckle radius KR that is 17.3% in length relative to the tank head OD, wherein the knuckle radius KR is blended with the primary dish radius DR. Flanged ellipsoidal dish 70 further includes a straight flange region 72 at the periphery of the dish. An example of an automatic flanging machine suitable for use in practicing the present invention is a Type BF 25/6 Automatic Flanging Machine available from Faccin USA, Inc. of South Tampa, Fla. This is but one example, and other flanging machines may be used without straying from the invention. Similar to the first stage of cold-forming, the second stage of cold forming may be controlled by programming automatic flanging machine 52 .
During the second stage of cold-forming, frictional contact between rollers 58 and 60 and the spinning dish 50 is converted to heat that raises the temperature of the steel. If the steel is heated above 200° F., unexpected material deformation may occur. Therefore, the temperature of the steel is monitored in conjunction with rotating dish 50 . In FIG. 1 , this is represented by blocks 18 and 20 executed simultaneously with the flanging operation. The temperature may be monitored while the dish is spinning by an infra-red thermal meter (i.e. a “heat gun”) or by thermo-melt heat sticks. Decision block 20 determines if the measured temperature is approaching the 200° F. limit. If so, a temporary pause 22 is provided in the cold-forming operation to allow heat to dissipate.
The dimensions of flanged ellipsoidal dish 70 will depend on the diameter of the railroad car tank for which the tank car head is intended. Purely by way of example, applicant has successfully tested its method in meeting a railroad tank head specification calling for an outer diameter (OD) of 123.5 inches, an overall height H of 34.251 inches, and a flange height F of 2.625 inches. While the flanged ellipsoidal dish 70 is loaded in flanging machine 52 , an edge conditioning operation may be run using a shaving tool positioned to shave the top edge of flange region 72 to achieve a desired flatness tolerance of flange region. The edge conditioning operation prepares flanged ellipsoidal dish 70 for welding to an end of a cylindrical tank by a circumferential weld.
Once the flanging stage is complete, the flanged ellipsoidal dish 70 is heat treated as represented by block 24 in FIG. 1 . In one embodiment, heat treatment may include thermally stress relieving the flanged ellipsoidal dish 70 . In another embodiment, heat treatment may include normalizing the flanged ellipsoidal dish 70 .
The thermal stress relieve procedure involves heat treating the flanged ellipsoidal dish at a temperature below the normalization temperature of the steel plate material. In an embodiment of the invention, thermal stress relieving is conducted by placing the flanged ellipsoidal dish 70 into a furnace set at not more than 800° F., ramping the furnace temperature up to 1150° F. at a rate not exceeding 400° F./hr, holding the furnace temperature at 1150° F.±50° F. for a minimum of one hour up to four hours, gradually cooling the furnace back down to 400° F. at a cooling rate not exceeding 500° F./hr, then cooling the flanged ellipsoidal dish 70 in still air. For dtress relieving, the flanged dish 70 may be supported on a fixture with the concave portion of the dish facing downward. The fixture may include internal piers and circumferential shims configured to maintain dimensional stability of the flanged dish 70 , and to allow uniform heat flow to all portions of the flanged dish for uniform heating of the steel.
In the thermal stress relieve procedure described above, the holding time is increased relative to conventional stress relieve procedures, which typically call for a holding time of one hour per inch of thickness (i.e. about half an hour for a 9/16 inch thick dish). The thermal stress relieve re-establishes good ductile to brittle impact characteristics of the cold-formed material at an equivalent level to that derived from normalizing heat treatment. In order to achieve this conclusion, the applicant conducted tests varying the holding time at one-hour increments (one, two, three and four hours). Applicant has found that the holding time greatly affects the material's ability to absorb impact energy, as measured by the Charpy impact test. This aspect is critical in tank car heads, as discussed above in relation to the specifications in AAR M-1002. FIG. 9 illustrates the effect of holding time and provides a comparison of lower temperature stress relieving heat treatments relative to higher temperature normalizing heat treatments. FIG. 9 shows the results of Charpy impact tests conducted at −50° C. on seven different specimens. Specimen AR (“as received”) is a specimen cold-formed from ASTM TC128, Grade B, normalized steel plate that was not heat treated in any way. Specimen NR1 was normalized at 1700° F. after cold-forming and gradually cooled at a controlled rate, and specimen NR2 was also normalized at 1700° F. after cold-forming but was rapidly cooled at an uncontrolled rate. Specimens SR1, SR2, SR3, and SR4 were stress relieved at 1100° F. for one hour, two hours, three hours, and four hours, respectively, and then subjected to gradual controlled cooling. As expected, NR1 easily meets the standards in AAR M-1002. Specimens SR2, SR3 and SR4 demonstrate that stress relieving the flanged ellipsoidal dish 70 at a temperature below the normalization temperature can produce a tank car head that meets the impact toughness standards of AAR M-1002, provided that the holding time is sufficiently long and controlled cooling is used. While stress relieving for a period on a range of two hours up to four hours appears to be optimal, it is possible that a shorter time of one hour will provide sufficient toughness for certain applications.
The stress relieving step may be performed before the flanged ellipsoidal dish 70 is welded onto an end of a cylindrical tank, or it may be performed after such welding. For example, an entire welded tank of the railroad tank, including a pair of flanged ellipsoidal dishes 70 at opposite ends, may be stress relieved after fabrication and welding. In this case, thermally stress relieving the tank head before welding it to the tank body may not be required.
As mentioned, heat treatment step 24 in FIG. 1 may be a normalizing heat treatment rather than a thermal stress relieving heat treatment. The normalizing process may be carried out by heating the flanged dish 70 to a temperature just into the fully austenite region of the steel. For example, in the case where material thickness is 9/16 inches, the flanged dish 70 may be normalized at 1700° F.±50° F. for more than one-half hour but less than one hour to allow recrystallization. This is followed by cooling flanged dish 70 in air at room temperature. Normalizing refines the grain size of the steel to improve its toughness.
While the invention has been described in connection with exemplary embodiments, the detailed description is not intended to limit the scope of the invention to the particular forms set forth. The invention is intended to cover such alternatives, modifications and equivalents of the described embodiment as may be included within the spirit and scope of the invention. | A method of manufacturing a railroad car tank head includes the steps of providing a circular blank of steel plate material, cold-forming the circular blank to form an intermediate ellipsoidal dish, cold-forming a peripheral flange region of the intermediate ellipsoidal dish to form a flanged ellipsoidal dish, and heat treating the flanged ellipsoidal dish. The heat treatment may be either a thermal stress relieving heat treatment or a normalizing heat treatment. The two cold-forming steps may be carried out at room temperature. The present invention provides a method of making a railroad car tank head that is more efficient than prior methods, avoids the challenges of hot-forming and single-stage cold-forming, is easily adaptable to different tank head diameters using the same forming equipment, and yields a railroad car tank head that meets safety standards. | 1 |
RELATED APPLICATION
[0001] The present disclosure relates to subject matter contained in priority Korean Application No. 10-2007-0093296, filed on Sep. 13, 2007, which is herein expressly incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a washing/drying machine, and more particularly, to a washing/drying machine which enhances an assembly structure of a front cover and a control panel.
[0004] 2. Background of the Invention
[0005] In general, a washing/drying machine includes a washing machine, a drying machine, a refresher, and the like. Hereinafter, a drum type washing machine is described as an example of the washing/drying machine.
[0006] FIG. 1 is a perspective view of a drum type washing machine. Referring to FIG. 1 , the drum type washing machine may include a box-shaped cabinet 1 forming an outer aspect of the washing/drying machine. A tub (not shown) and a drum (not shown) are disposed inside the cabinet 1 . An opening is formed in a front surface of the cabinet 1 so as to mount the tub and the drum therein.
[0007] A cover 2 is provided at one side of the opening of the cabinet 1 . And, a lower end of the cover 2 is disposed to be stopped by a lower end of the cabinet 1 or coupled to the lower end thereof.
[0008] An upper jaw 25 is formed at an upper end of the cover 2 , a second coupling portion 21 extending from the upper jaw 25 with a certain length is disposed so as to be coupled to the cabinet 1 . A plurality of second threaded holes 22 are disposed at the second coupling portion 21 for a thread coupling. In addition, a hook coupling hole 23 is formed at an approximately central portion of the upper portion of the cover 2 in a lengthwise direction.
[0009] Meanwhile, a control panel mounting portion 11 is disposed at the upper portion of the cabinet 1 so as to mount a control panel (not shown). A first coupling portion 12 extends downwardly from a lower end of the control panel mounting portion 11 with a certain length so as to be coupled to the cover 2 .
[0010] A plurality of first threaded holes 13 are provided in the first coupling portion 12 , and a hook 14 is disposed at an approximately central portion of the first coupling portion 12 in the lengthwise direction. Preferably, the hook 14 is integrally formed with the first coupling portion 12 . The hook 14 may be formed at either an upper side of the cabinet 1 or an upper end of the cover 2 .
[0011] However, in an assembly process of the drum type washing machine, an operator is required to thread-couple the cover to the cabinet while holding the cover in one hand. Accordingly, the operator may use only one hand for the thread coupling, thereby causing an inconvenience. In addition, if the operator moves a little bit, threaded holes of the cabinet and threaded holes of the cover are not aligned with each other, thereby causing a problem in thread coupling and taking a long time to assemble.
[0012] In addition, the control panel needs to be mounted after the cover is mounted at the control panel mounting portion. That is, in order to form the front surface of the drum type washing machine, a number of components need to be assembled in multiple steps.
SUMMARY OF THE INVENTION
[0013] Therefore, an object of the present invention is to provide a washing/drying machine which assembles a cover and a control panel in one operation.
[0014] Another object of the present invention is to provide a washing/drying machine having a structure in which the cover is fixed by being pressed by the control panel, thus to fix the cover when the control panel is fixed.
[0015] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a washing/drying machine, including: a cabinet forming an outer aspect of a washing/drying machine, a cover forming at least a portion of a front surface of the cabinet, and a control panel installed at the cover and having a variety of buttons, wherein the control panel is installed at a control panel mounting portion of the cover while pressing a flange formed at an upper end of the cover.
[0016] With these configurations, an inconvenience of separately assembling the cover and the control panel may be reduced, and productivity is enhanced. That is, the cover and the control panel may simultaneously be assembled, without having to assemble the control panel after assembling the cover.
[0017] Here, the control panel is fixed by a hook formed at the cover, which can prevent an inconvenience to couple a number of screws to the cover for fixing the cover.
[0018] In addition, a knob hole for mounting a rotary knob is disposed at the control panel. A knob deco disposed at a periphery of the rotary knob for indicating a manipulation of the rotary knob is mounted at the knob hole. A knob deco coupling means is provided so as to couple the knob deco to the knob hole of the control panel. As an example of the knob deco coupling means, a hook may be formed at a periphery of the knob hole of the control panel.
[0019] In addition, a stopping hook may be formed at the knob deco, or a mounting flange may be formed at an edge of the knob deco.
[0020] Meanwhile, a display window for installing a display is formed at the control panel, and the display having touch-sensitive buttons is mounted at the display window. If the cover is formed of a stainless steel material, the touch-sensitive buttons may also be formed of the stainless steel material, thus to provide a uniform external appearance.
[0021] A window flange is formed at an edge of the display. A lower end of the window flange is inserted into the control panel, and an upper end thereof is coupled by the hook formed at the control panel.
[0022] Preferably, the flange of the cover is formed at an edge of the control panel mounting portion. In order for the cover to be fixed by the control panel mounted at the control panel mounting portion, a flange needs to be formed at an edge of the control panel mounting portion. It is effective that the flange is formed to face the rear of the cover so as to prevent a protrusion of the cover or the control panel after assembling the cover.
[0023] A panel flange is formed at an edge of the control panel, and a plurality of coupling holes are formed at the panel flange. By coupling the coupling holes to a coupling means (e.g., a screw, etc.), the cover and the control panel may be firmly fixed to a plastic frame disposed rear the control panel and for installing a variety of electronic components.
[0024] Meanwhile, the cover is formed of a stainless steel material and implemented in one body. With such configuration, even though the cover is integrally formed using the stainless steel material, the assembly structure of the cover and the control panel becomes simplified, thereby increasing productivity and promoting a stylish image of a product.
[0025] In the present invention, the cover and the control panel are coupled in one assembly operation, thereby providing a washing/drying machine which can simplify an assembly process as well as increase the productivity.
[0026] In addition, the present invention employs a structure in which the cover is fixed by being pressed by the control panel, thereby providing a washing/drying machine which can assemble the cover and the control panel, without using a coupling means (e.g., a screw, etc.).
[0027] In addition, the present invention provides an assembly structure in which the cover and the control panel, which are integrally formed, are easily assembled, thereby enabling mass production of a high-quality washing/drying machine having a cover integrally formed using a stainless steel material.
[0028] In the present invention, the cover is integrally formed using the stainless steel material, thereby enhancing a stylish image of a product.
[0029] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0031] In the drawings:
[0032] FIG. 1 is a perspective view of a drum type washing machine;
[0033] FIG. 2 is a perspective view of a cover according to one embodiment of the present invention;
[0034] FIG. 3 is a front view of a control panel mounted at the cover in FIG. 2 ;
[0035] FIG. 4 is a cross-sectional view taken along line ‘IV-IV’ in FIG. 3 ;
[0036] FIG. 5 is an enlarged perspective view of a part “A” in FIG. 4 ;
[0037] FIG. 6 is a cross-sectional view taken along line ‘VI-VI’ in FIG. 3 ;
[0038] FIG. 7 is an enlarged perspective view of a part “B” in FIG. 6 ;
[0039] FIG. 8 is a cross-sectional view taken along line ‘VIII-VIII’ in FIG. 3 ; and
[0040] FIG. 9 is an enlarged perspective view of a part “C” in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0041] Description will now be given in detail of the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The following description represents many aspects that can be claimed, and constitutes a part of detailed description about the present invention.
[0042] Detailed explanation about well-known functions or configurations will be omitted so as to implement the present invention more explicitly.
[0043] Hereinafter, for the sake of convenience in explanation, a drum type washing machine as an example of the washing/drying machine will be described in detail. Configurations of the drum type washing machine, except an assembly structure of a control panel and a cover, are the same as those of the drum type washing machine described in FIG. 1 , and detailed explanations therefor are omitted.
[0044] FIG. 2 is a perspective view of a cover according to one embodiment of the present invention, and FIG. 3 is a front view of a control panel mounted at the cover in FIG. 2 .
[0045] Referring to FIG. 2 , the cover 100 according to one embodiment of the present invention may include an opening 104 disposed at an approximately central portion thereof for mounting a door (not shown), and a control panel mounting portion 101 penetratingly disposed at an upper portion thereof for mounting a control panel.
[0046] Here, the cover 100 is formed of a stainless steel material and implemented in one body. Preferably, a drawing technique is used to form the cover 100 having one body by using the stainless steel material.
[0047] In addition, in order to enhance processability of the cover 100 through the drawing technique, STS 300-series materials have been selected through the research on properties of various stainless steels.
[0048] Here, instead of the stainless steel, a bonded steel plate formed of a different material may be used. For instance, the front surface of the cover 100 may be formed of the stainless steel material, and a rear surface thereof may be formed of a material having an excellent elongation (e.g., aluminum, etc.), thus to provide a material having an external appearance of a metallic color, high elongation, and reduced work-hardening.
[0049] Here, a flange 102 is formed at an upper portion of the cover 100 , more specifically, at an edge of the control panel mounting portion 101 . As shown in FIG. 3 , a control panel 120 is mounted at the control panel mounting portion 101 while pressing the flange 102 formed at the upper portion of the cover 100 .
[0050] Accordingly, there is no need to separately assemble the cover 100 and the control panel 120 , i.e., the cover 100 and the control panel 120 are simultaneously assembled, thereby raising the productivity.
[0051] Here, a control panel frame 110 is a component for mounting a plastic frame (not shown) where a variety of electronic components are installed. The control panel frame 110 and the control panel 120 may be separately formed or integrally formed as one component. That is, the control panel frame 110 , the plastic frame and the control panel 120 may be formed as one module.
[0052] A detergent case opening 123 for pushing into and pulling out a detergent case is formed at one side of the control panel 120 . A knob hole 121 for inserting a rotary knob (not shown) is formed at almost the central portion of the control panel 120 . A display window 122 for mounting a display 130 on which operation information of the washing/drying machine is displayed is penetratingly formed at another side of the control panel 120 . In addition, a plurality of button holes (not shown) for mounting a variety of buttons may be formed.
[0053] Meanwhile, a panel flange 125 for mounting the control panel 120 to the cover 100 is formed at an edge of the control panel 120 . The panel flange 125 protrudes more rearwardly than the control panel 120 , and a plurality of coupling holes 126 are formed at the panel flange 125 . The coupling holes 126 are to thread-couple the panel flange 125 to the plastic frame (not shown) disposed rearward the panel flange 125 .
[0054] Hereinafter, description of the assembly structure of the control panel 120 and the cover 100 will be given in detail.
[0055] FIG. 4 is a cross-sectional view taken along line ‘IV-IV’ in FIG. 3 . FIG. 5 is an enlarged perspective view of a part “A” in FIG. 4 . FIG. 6 is a cross-sectional view taken along line ‘VI-VI’ in FIG. 3 . FIG. 7 is an enlarged perspective view of a part “B” in FIG. 6 . FIG. 8 is a cross-sectional view taken along line ‘VIII-VIII’ in FIG. 3 , and FIG. 9 is an enlarged perspective view of a part “C” in FIG. 8 .
[0056] Referring to FIGS. 4 and 5 , the part taken along line ‘IV-IV’ is a portion where no electronic components are installed at the rear of the control panel 120 . That is, a lower end of the control panel 120 in the part taken along line ‘IV-IV’ is configured to press the flange 102 of the control panel mounting portion 101 , and an upper end thereof is configured to be coupled to the cover 100 by the hook 127 formed at the cover 100 .
[0057] Here, the panel flange 125 formed at the edge of the control panel 120 contacts the flange 102 of the cover 100 . The flange 102 formed at the lower edge of the control panel mounting portion 101 of the cover 100 is coupled by being pressed by the lower end of the control panel 120 .
[0058] The panel flange 125 is pressed between the upper edge of the control panel mounting portion 101 of the cover 100 and the hook 127 , thereby fixing the cover 100 and the control panel 120 to each other.
[0059] Preferably, at least 6 or more hooks 127 may be provided along the panel flange 125 .
[0060] Since the cover 100 and the control panel 120 are fixed by the hooks 127 , there is no need to use a number of screws to fix the control panel 120 to the cover 100 .
[0061] Referring to FIGS. 6 and 7 , a knob hole 121 for installing a rotary knob (not shown) is formed at the control panel 120 . A knob deco 150 enclosing a circumference of the rotary knob for indicating a manipulation of the rotary knob is installed at the knob hole 121 . A knob deco coupling means 128 is provided so as to couple the knob deco 150 to the knob hole 121 of the control panel 120 . As an example of the knob deco coupling means 128 , a hook 128 may be disposed around the knob hole 121 of the control panel 120 .
[0062] Here, the knob deco 150 is fixed to the control panel 120 by the hook 128 formed at the plastic frame 140 disposed at a rear surface of the control panel 120 .
[0063] Since the hook 128 is tapered at the rear of the control panel 120 , the knob deco 150 may easily be coupled to the hook 128 when it is pushed from the rear of the control panel 120 .
[0064] In addition, the panel flange 125 of the control panel 120 may be fixed by the cover 100 .
[0065] In addition, as the knob deco coupling means, a stopping hook (not shown) or a mounting flange (not shown) may be formed at an edge of the knob deco 150 .
[0066] Referring to FIGS. 8 and 9 , the control panel 120 may include a display window 122 for installing a display screen, and a display 130 having touch-sensitive buttons 131 ( FIG. 3 ) is mounted at the display window 122 .
[0067] Here, if the cover 100 is formed of the stainless steel material, the touch-sensitive buttons 131 may be formed of the stainless steel material so as to provide a uniform external appearance.
[0068] In addition, a window flange 132 is bent at an edge of the display 130 . A lower end of the window flange 132 is inserted between the control panel 120 and the plastic frame 140 or the control panel frame 110 , and an upper end thereof is coupled by the hook 129 formed at the control panel 120 .
[0069] Here, the window flange 132 is pressed by the panel flange 125 of the control panel 120 or the cover 100 , and an end of the cover 100 is pressed by the panel flange 125 of the control panel 120 .
[0070] Since the hook 129 is formed inside the control panel 120 , the display 130 may easily be coupled to the hook 129 if the display 130 is pushed from the rear of the control panel 120 .
[0071] Meanwhile, the flange 102 of the cover 100 is formed at the edge (circumference) of the control panel mounting portion 101 . In order for the cover 100 to be fixed by the control panel 120 mounted at the control panel mounting portion 101 , the cover flange 102 should be formed at the periphery of the control panel mounting portion 101 . In order to prevent a protrusion of the cover 100 or the control panel 120 after assembling the control panel 120 , it is effective that the flange 102 is formed to face the rear of the cover 100 , i.e., the inside of the washing/drying machine.
[0072] As described above, the cover 100 is formed of the stainless steel material and implemented in one body. With such configuration, even though the cover 100 is integrally formed using the stainless steel material, the assembly structure of the cover 100 and the control panel 120 may be simplified, thereby enhancing the productivity as well as promoting a stylish image of the washing/drying machine.
[0073] The drum type washing machine has been described as an example of the washing/drying machine. However, the present invention may also be applied to a variety of electronic appliances, such as the drum type washing machine, the drum type washing/drying machine, and the drying machine as well as an integrated washing system, a refresher, a dishwasher, or the like.
[0074] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.
[0075] As the present invention may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims. | Disclosed is the washing/drying machine, including: a cabinet forming an outer aspect of a washing/drying machine, a cover forming at least a portion of a front surface of the cabinet, and a control panel disposed at the cover and having a variety of buttons, wherein the control panel is mounted at the control panel mounting portion formed at the cover while pressing the flange formed at an upper end of the cover, thereby simultaneously coupling the cover and the control panel in one operation, thus to simplify an assembly process and increase productivity. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fish catcher mounted at the end of a fishing line and more particularly to improvements in a fish catcher which is made of a bent rod which is designed to draw a hook line automatically and resiliently upward when a fish snaps at the bait of a fishing hook at the end of the hook line suspended from one end of the bent rod.
2. Description of the Prior Art
The present inventor already proposed a fish catcher of the structure substantially described above in Japanese Patent Publication No. 69187/1978 (U.S. Pat. No. 4,141,168), and the present invention is an improvement over the this prior art.
In the prior art, identified above, when a hook is brought into elastic engagement with a hook ring and a catcher is set ready for action, the elastic engagement is effected either by drawing a hook line downward with both finger tips of one hand and during the time placing fingers of another hand in the position in which to help bring both the hook and ring into engagement and then by engaging the hook with the ring or by drawing a leg rod and a leg rod close to each other with fingers of both hands in the direction of engagement. The fact, however, is that the manipulation for engagement described above is exceedingly cumbersome at a fishing place where the angler is exposed to wind, rain and snow and finds it difficult to handle a fishing tackle, and particularly in winter time the angler finds it difficult to manipulate the tackle because his fingers become stiff with cold.
When the catcher is cast into the water after completion of the elastic engagement of the hook and ring of the catcher, it sometimes happens that the collision of the catcher with the water surface, subjection thereof to underwater current or catching thereof by rocks and reefs tends to disengage the engaged catcher before a fish snaps at the bait of the catcher, bringing the intended fishing to failure.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to eliminate the above drawbacks.
According to the present invention, a hook and a hook ring are brought into definite engagement by mere operation of drawing down the hook line by fingers of one hand and it is not at all necessary to draw the hook and the hook ring close to each other at their positions of engagement by fingers or to ascertain the engagement of the hook and the hook ring visually, and the engagement of them can reliably be effected by the above operation in a blind manner. Also, the catcher at the present invention is so designed as to be in readiness for operation in such a manner that the disengagement of the hook from the hook ring is not effected after the engagement thereof before the catcher has been sunk under the water, and only when the catcher is subjected to the buoyance of the water, the hook is disengaged from the hook ring. According to the means which the invention employs for achieving the operation above, a center rod is passed through the middle of bent rod and a swing maker cooperating with a float is mounted on the center rod so as to make the float function as a guide which controls the swing of the swing maker before the catcher is subjected to the buoyancy of the water and which brings the hook into engagement with the hook ring and on the other hand a means is employed to make it reliable to effect elastic engagement by making the float move afloat away from the swing maker after the catcher has been subjected to the buoyancy of the eater and drawing a hook line downward at the time of jerking by a fish. The feature of the invention that makes it possible to provide a reliable elastic engagement before the elastically engaged hook and hook ring are sunk under the water renders the catcher of the invention adaptive for use also in surf-fishing in which a relatively strong force is applied to the end of the fishing line.
A detailed description of a preferred embodiment of the invention will now be given with reference to the accompanying drawings in which like reference characters are used for denoting like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view showing an embodiment of the fish catcher of the present invention set in a ready-to-operate position;
FIG. 2 is a plan view of FIG. 1;
FIG. 3 is a front view showing the fish catcher of the invention set under the water;
FIGS. 4A and 4B are an illustration showing the course of engagement of a hook ring with a hook;
FIGS. 4C and 4D are an illustration showing the course of disengagement of the hook ring from the hook by a jerk of a fish; and
FIG. 5 is a front view showing a state of elastic disengagement of the hook ring from the hook.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, the numeral 1 designates a bent rod obtained by bending a relatively thin elastic material e.g., a stainless steel wire, within its elastic limit and is designed to provide substantially an arcuate form by the elastic engagement (to be described later) of a hook ring 14 with a hook 6. The numeral 2 designates a center rod inserted longitudinally slideably into an eyelet 11 formed in substantially the middle of the upper portion of the bent rod 1 and into an eyelet 12 formed at one end of the bent rod 1. To the other end of the bent rod 1 is pivotally connected through an eyelet 13 an inward engagement rod 15 having a hook ring 14 at its end. In the middle of the center rod 2 is provided a bracket 3 slightly projecting toward the inward engagement rod 15 side, and on the bracket 3 is swingably attached a swing maker 4 which is equipped on the inward engagement rod 15 side with a guide ring 41 designed to loosely insert the hook ring 14 therethrough and on the opposite side with an engagement edge 42 engageable with a float 5. A hook 6 extending downwardly from the bracket 3 is provided below the swing maker 4 and immediately below the hook 6 is provided an inward ring 7 extending from the center rod 2. A float 5 is slidably passed through on the center rod 2 and, as shown in FIG. 1, when the float 5 is in its lowermost position, the float 5 is on the swing maker 4 and with respect to the force to swing the swing maker 4 to the right in the drawings, the float 5 prevents the swing maker 4 from swinging further by the engagement of the float 5 and the edge 42 of the swing maker 4, but when the float 5 moves upward afloat along the center rod 2 under the buoyance of the water, the swing maker 4 is allowed to be swung to the right in the drawings. The lower end of the rod 2 is bent outwardly to form an eyelet 21 at the end nd loosely receives one end of the bent rod 1 into the eyelet 21 and is adapted to bring the rod 1 into substantially parallel relation with the center rod 2 when the rod 1 is brought into a straightforward position (referred to as a linear rod 1') as shown in FIG. 5 by cooperation of the eyelet 11 with the eyelet 12. A hook line 8 is suspended from the base side of the hook ring 14 through a guide ring 41 and the inward ring 7. To the top of the center rod 2 is attached a fishing line 9 through an eyelet 22.
A description will be given of how the fish catcher of the present invention is used and of the operating principle of the fish catcher. Before the catcher is used, the linear rod 1' and the center rod 2 are maintained in substantially parallel relation between the eyelet 11 and the eyelet 12 as shown in FIG. 5. In setting the catcher ready for operation as shown in FIG. 4(A), a portion between the eyelets 11 and 12 of the rod is gripped by the fingers LF of one hand and the hook line 8 is drawn downward by fingers RF of another hand in the state of the float 5 being placed on the swing maker 4. Then, the rod 1' is resiliently bent into an arc to provide the bent rod 1, and the inward bent rod 15 is drawn in the direction of the guide ring 41 of the swing maker 4 in the state of maintaining pivotal movement with respect to the rod 1 with the eyelet 13 used as a pivot point. With an increase in the tension of the hook line 8, as shown in FIG. 4(B), the rod 15 passes together with its ring 14 through the guide ring 41 and collides with the hook 6, and when the rod 15 is further drawn, it pivots downward to the right with the eyelet 13 as a pivot point and comes right under the hook 6. When the drawing of the hook line 8 is stopped at this junction, the righting elasticity of the rod 1 works upon the inward engagement rod 15, to thereby reversely pivot upward to the left with the pivot point as a base point and to bring the hook ring 14 into fitting over the base of the hook 6 to bring about a ready-to-operate state of the fish catcher (FIG. 1). At this time, the swing maker 4 is prevented from swinging downward to the right by the engagement of the float 5 and the engagement edge 42, and the guide ring 41 is maintained in substantially immovable relation with respect to the hook ring 14. Accordingly, if the swing maker 4 is provided integrally with the ring 41 and the edge 42 in such a manner as the ring 41 and the edge 42 are maintained in proper position, the hook ring 14 is stable with respect to the guide ring 41 to make the catcher sink smoothly. Also, when the bent rod 1 is kept slidable (not fixed) with respect to the center rod 2 through the eyelet 11, bending of the bent rod 1 by drawing of the hook line 8 elastically bend the bent rod 1 along its overall length, resulting that resilient drawing up of the hook line 8 in time of release of the elastic engagement is very effectively carried out. This, however, does not constitute an important part of the invention and it should be understood that fixing of the bent rod 1 to the center rod 2 at the point corresponding to the eyelet 11 does not deprive the invention of its function.
Before the catcher of the invention is sunk under the water with the catcher maintained in a ready-to-operate state, application of external force to the inward engagement rod 15 in the direction of the hook ring 14 being disengaged from the hook 6 (such force as that produced by collision of the catcher with the water surface, rocks and reefs or by underwater current) makes the rod 15 push the guide ring 41 downward to the right in the drawings, but the float 5 is increased in engaging force with respect to the engagement edge 42 to thereby prevent the swing maker 4 from swinging downward to the right in the drawing, resulting that the hook ring 14 is protected against slipping out of the hook 6.
However, when the catcher is sunk under the water and subjected to the buoyancy of the water, the float 5 is moved upward along the center rod 2 and is disengaged from the edge 42 (FIG. 3). Accordingly, if the hook line 8 is pulled downward by a jerk of a fish in this state of the float having been released, the inward rod 15 is pivoted downward with the eyelet 13 as a pivot point, and presses the guide ring 41 downward on the way and swings the swing maker 4 downward to the right to detach the hook ring 14 from the hook 6 (FIG. 4C), and at this moment the hook line 8 is instantly raised right above by the righting elasticity of the bent rod 1 and hooks the mouth or its adjacent parts of a fish, thus making it possible to catch the fish unfailingly (FIG. 4D). Whenever, therefore, the fish F at this time has a bait (not shown) in its mouth or is in the act of snapping at the bait or in the preliminary act of snapping at the bait, the hook 10 is struck into the mouth and its adjacent parts of the fish F and hooks the mouth and in consequence there is no chance of the hook 10 being swallowed by the fish F. The inward ring 7 illustrated in the embodiment serves as a guide to draw the hook line 8 directly upward at time of the disengagement of the hook ring 14 from the hook 6, and this is because the inward ring 7 is provided on the rod 2 and the resilience of legs of the rod 1 opening is not directly applied to the ring 7. This state of hooking is visible either through a float (not shown) at a suitable point of the fishing line 9 or ascertained through the sense of touch which an angler feels at the end of his fishing rod, so that the angler is enabled to draw up the fishing rod and catch a fish with ease. Release of the elastic engagement makes the catcher of the invention being about the state shown in FIG. 5 and the catcher is brought onto the land as it is in the state thus brought about and enters the next step of fishing operation. In this case, where there is not buoyancy, the float 5 slides down along the center rod 2 to push the engagement edge 42 of the swing maker 4 downward to the left in the drawings and sit on the swing maker 4, and hence setting for subsequent fishing is very easy.
As will have been understood from the description given above, the present invention provides great advantages that the invention requires no troublesome manipulation by fingers or visual ascertainment in engagement of the hook ring with the hook but renders it possible to make blind elastic engagement, elastic engagement of the hook ring with the hook is not released indiscriminately where there is no buoyancy but the elastic engagement is very delicately responsive to the force to draw the hook line downward in the water where there is no buoyancy and that accordingly the invention is highly effective in solving the problems related to the previous invention A and can enhance the anglers joy by the increased number of fishes they catch, ease of setting the catcher, positive locking function of setting the catcher before the catcher is put under the water and is also adaptable for use in surf-fishing.
In addition, since the use of the fish catcher of the present invention renders it unnecessary for the angler to coordinate his fishing line in the movement of a float, but when the fishing line is lowered by the disengagement of the resiliently engaged catcher elements under the water, upward drawing of the hook line is vertically decreased to the amount of the fishing line lowered. Accordingly, the use of float is recommended to prevent such lowering and when it is used, preferably a float having a high buoyance as shown in FIG. 3 is more favorable. In the structure shown, the bracket 3, swing maker 4, hook 6, inward ring 7, inward engagement rod 15 and hook ring 14, except the bent rod 1 and center rod 2, may be made of a plastic material, as the case may be. Furthermore, the bracket 3 and hook 6 may be made integrally of a plastic material. | A fish catcher comprising, an elastic bent rod, a center rod mounted on said bent rod and connected to said bent rod at its lower end, an inward engagement rod pivotally connected to the other end of said bent rod, said engagement rod having a hook ring at its end, a bracket extending from said center rod to be secured to said engagement rod, a swing maker swingably provided on said bracket, said maker having a guide ring at its end to be engaged with said engagement rod and an engagement edge at the other end thereof, a hook provided downwardly on said bracket, an inward ring formed directly below said hook of said center rod, a float provided loosely around said center rod, and a hook line connected to said inward engagement rod and to pass through said inward ring. By thus contructing, a hook line will be automatically and resiliently drawn so that a fish would be kept hooked. | 0 |
FIELD OF THE INVENTION
The present invention concerns an ionization vacuum gauge and generally the measurement of extremely low pressures in chambers where an ultra-vacuum exists (the ultra-vacuum including the ultra-vacuum extreme limit).
BACKGROUND OF THE INVENTION
The vacuum gauges used to this effect are known to be ionization gauges which measure the pressure of the ultra-vacuum from the density of the particles the ultra-vacuum atmosphere contains, said atmosphere being itself contained in a specific recipient. The known principle for functioning of these gauges consists of ionizing one proportion of the molecules and atoms of the gas constituting this atmosphere via impact with electrons derived from a source whose flowrate is known. The gas ions formed are then collected by a measuring electrode of the system and the ionic current obtained is an analogous measurement of the pressure of the ultra-vacuum existing in the chamber.
It is also known that the formation of said molecules takes place in two different ways. In ionization vacuum gauges, known as cold cathode or Penning gauges, the ions are formed in a maintained electric discharge and at high intensity in the presence of a homogeneous magnetic field. In another category of vacuum gauges, ionization is produced via the collision with electrons emitted by a heated filament, these ionization vacuum gauges being hot cathode ionization vacuum gauges. The present invention concerns a vacuum gauge derived from a type of hot cathode vacuum gauges known under the name of Bayard-Alpert vacuum gauges, reference firstly being made to the principle associated with FIG. 1 which describes a device of the prior art.
The Bayard-Alpert gauge described in FIG. 1, which is an exploded skeleton diagram, mainly includes a chamber 1 containing the ultra-vacuum atmosphere whose pressure is desired to be determined. This chamber 1 contains the three electrodes of the system, namely a hot cathode or filament 2 intended for the emission of a flow of electrons, an anode grid 3 and, along the axis of the chamber 1, an ions collector 4. In the example shown, the anode grid surrounds the collector which is disposed along the axis of the chamber 1, but this is not strictly the case for all Bayard-Alpert type gauges. This gauge operates at low voltage and in the absence of any magnetic field. The thermoelectronic electrons emitted by the cathode 2 are accelerated in the electric field created by the polarization of the anode 3 and acquire there sufficient energy so as to ionize the gas contained in the inter-electrode system. The positive ions created by impacts are attracted by the collector 4 found at a potential close to that of the chamber and the current thus produced makes it possible to measure the pressure. The electrons are finally captured by the anode 3 which most frequently appears in the form of a helical wire. The hot cathode is a highly productive source of electrons which enables high sensitivity to be obtained, particularly at extremely low pressure. Moreover, hot cathode gauges have, as compared with cold cathode gauges, a much weaker pumping effect by an order of magnitude.
The upper pressure limit able to be measured by this system is several 10 -3 mbars; this is mainly due to the fact that, at higher pressures, electric arcs or luminous discharges may occur. The filament then may possibly burn. At lower pressures, the measurement is limited by two physical effects, namely:
the desorption effect of the anode under the influence of the electrons striking it. This effect is independent of the pressure but is proportional to the electronic emission current.
the Rontgen effect: when the electrons strike the anode, they free photons (soft X-radiation) which in turn create photoelectrons when striking various surfaces, including the collector. The photoelectrons freed by the collector flow to the anode, thus creating a current of the same direction as the ionic current. For Bayard-Alpert gauges, this effect becomes preponderant within the range of 10 -10 mbars.
The hot cathode 2 is formed of a filament located outside the volume delimited by the grid. The electrons emitted by the cathode go backwards and forwards through the grid until they are trapped. By way of example, for a vacuum of 10 -8 mbars and an electronic current of 1 mA, an ionic current of 10 pA is obtained (for a gauge factor of 10 mbars -1 ).
The main defect of hot cathode gauges derives from the systematic use of a heating filament as a source of electrons.
This type of thermoelectronic source is in fact isotropic, whereas the directivity of the beam of electrons is an important parameter as regards gauge sensitivity. In fact, it has been shown that the average length of the electron trajectories is that much longer when the latter are radial, that is directed towards the collector 4, and it is known that the probability of ionization of the gas inside the zone delimited by the grid 3 is directly proportional to this average length (the ionization probability increases with the length). It is solely to the extent that the field is fully homogeneous around the filament 2 that the beam is reconcentrated by the grid; this is why the sensitivity of the guage is highly dependent on the position of the filament 2, which in addition may move during the time period or sag under the effect of the heat (about 2000° C.), all the more so when the electrons emitted by the filament leave the latter with a kinetic energy of almost nil and without directivity. Similarly, the fact that the source is relatively extended and that all its points do not emit in a similar way renders it more difficult to reconcentrate the beam of electrons and adversely affects its regularity. These two reasons mean that the sensitivity of the gauge is time-unstable parameter and to a certain extent cannot be reproduced. In addition, the electron emission phenomenon is originally thermic and costly in energy terms, has an extremely long response time and, in certain applications, is a significant pollutive factor.
Another concept for measuring the vacuum is described in the British review "Discovery", vol. 25, No 10, October 1964, p.15-16.
This structure, able to measure vacuum absolutes, uses the emission of electrons by tungsten points, with a diameter of several thousands of Angstrom units, used as emissive cathodes and comprising the cut extremity of macroscopic metallic rods, similar to nails. These macropoints and a polarized anode are placed in the chamber where it is desired to measure the vacuum degree. An electric current is thus established between the points constituting the cathode and the polarized anode. The recommended method consists of measuring the fluctuations of this current due to the gas atoms which are fixed to the points and are regarded as representative of the number of atoms present in the chamber, that is ultimately of the pressure. Apart from the fact that, at extremely low pressure, a large amount of time (several hours) is required to be able to correctly measure the pressure, such a system is difficult to use owing to the high instability of the cathodic source established.
SUMMARY OF THE INVENTION
The present invention concerns an ionization vacuum gauge derived from Bayard-Alpert type gauges and is able to simply resolve said drawbacks.
This ionization vacuum gauge is mainly characterized in that the source of electrons is a cold micropoint cathode.
As shall be seen subsequently, the fact of replacing the heating filament with a cold micropoint cathode of the type with emission via a field effect does not imply that the ionization vacuum gauge of the invention forms part of the category of cold cathode gauges. As mentioned earlier, this denomination is normally reserved for Penning gauges which are relatively resistant, less sensitive and function according to a totally different emission principle (electric discharge in a magnetic field).
Cold micropoint cathodes are of a type fully known concerning the technique and production of electrons via a field effect from emissive micropoint cathodes and are fully described in, for example, the French patents No. 2.593.953 and 2.623.013 and corresponding U.S. Pat. Nos. 4,857,161 and 4,940,916.
When the invention is implemented in a basic structure of the Bayard-Alpert type gauge, the filament is replaced by a micropoint cathode having, for example, a width of 1 mm and sufficient height so that the emissive surface allows a current to be obtained comparable to the one available with a filament. Knowing that the average emissivity of a micropoint cathode is 1 mA/mm 2 , a height of several centimeters is adequate to obtain a significant emission level.
The cathode is disposed in such a way that the micropoints are opposite the collector so that emission is clearly radial. Its distance with respect to the grid is calculated so that it interferes as little as possible with the field existing between the anode grid and the vacuum chamber, generally connected to the ground, and inside which the gauge is mounted.
The use of a cold micropoint cathode, which is an eminently directive source of electrons, thus makes it possible, by orientating it correctly in the direction of the anode and the ions collector, to be freed of the afore-mentioned drawbacks derived from the isotropic nature of the emission of a hot cathode in the form of a filament.
Technicians in the field concerning vacuum gauges did not understand why a filament could be replaced by a micropoint cathode. In fact, technicians are generally ignorant of developments relating to micropoints, either because these micropoints are used in display (screens) or are physically used on surfaces (tunnel microscopy). An article by C. Benventuri (Extreme Vacua: Achievement and Expectations, Physica Stripta, vol. T22, pages 48-54, 1988), a specialist in vacuums at the CERN advocated the use of hot filaments, and also recognized "cold" gauges as a possible alternative without envisaging the use of micropoint cathodes, known as Spindt devices since the 1970s.
A second important point concerning the novelty of the invention is the following: everyone, or nearly everyone, believes that it is necessary to have an extremely good vacuum (better than 10 -8 bars) so that the micropoints are able to emit an electronic current via the field effect in a durable and stable way. In other words, nobody envisaged using field effect micropoints in a pressure range of about between 10 -6 to 10 -3 mbars (to properly measure this pressure). Now, the gauge of the invention has no limits differing from those of a conventional Bayard-Alpert gauge, that is it can be made to function over a range from between 10 -3 and 10 -11 mbars, indeed from 10 -2 mbars.
Furthermore, the directivity of the electronic beam derived from a micropoint cathode depends on several parameters, including the form and size of the extraction grid, as well as the cathode/anode geometry (in the invention, it is the spirally-wound grid which acts as an anode). As the sensitivity of a vacuum gauge is directly dependent on the trajectories followed by the electrons, it was not clear that the fact of replacing the filament by a micropoint cathode retains or even improves sensitivity. This has only been able to be verified after simulation and experimentation. In the case where sensitivity would have decreased by a factor of 2, the advantage of using such a gauge would have been questionable. Currently, sensitivity is at least 1.5 times better.
The invention thus uses a micropoint cathode which may be matrix cathode with n cathodic electrodes (n being a whole number so that n≧1) disposed along lines or rows and feeding micropoints and m extracting grids (m being a whole number so that m≧1) disposed along columns and isolated from the cathodic electrodes.
If several cathodic electrodes are used, this redundancy makes it possible to still have an emission of electrons, even if some of these electrodes are out of operation.
The source of electrons used may be an emissive micropoint cathode of any type, such as the one described in the document FR-A-87 15432 (now FR 2623013 and U.S. Pat. No. 4,940,016). However, so as to obtain a relatively time-stable beam of electrons, which is extremely important for reliability of the measurement, it is specially advantageous to select a micropoint cathode provided with a resistive film, as described in the document FR-A-87 15432. This resistive film inserted between the cathodic electrodes and the actual micropoints thus plays the role of a buffer resistance and makes it posible to associate with each micropoint a particular resistance, thus resulting in obtaining extremely good homogenization of electronic emission.
According to the invention, the resistive film may be selected from a material in the group including indium oxide, tin oxide, iron oxide and doped silicon.
One of the additional advantages of the use of an emissive micropoint cathode resides in the fact that all the materials constituting such a cathode, for example glass, molybdene, silica, ITO (Indium tin oxide) are compatible with use in an ultra-vacuum. Note also that if the cathode is deposited on a silicon substrate, the baking temperature could increase (required for the embodiment of the ultra-vacuum) up to 600° C., which would be impossible on a glass substrate. However, as most bakings do not exceed 350° C., the question does not arise most of the time.
The cathodic electrodes are preferably carried to a potential Vc, the extraction grids to a potential Vg and the anode grid to a potential Va so that the electrons emitted by the source all have an initial kinetic energy equal to -e. (Vg-Vc) ranging from a minimum value required for extraction of the electrons to a maximum value less than or equal to -e. (Va-Vc), e being the electron charge.
The use of electrons possessing such initial energies allows for good sensitivity of the vacuum gauge, having regard to the fact that the major part of the electrons are not trapped when they first pass through the grid, contrary to the case of electrons emitted with an almost nil energy through the heating filaments.
Preferably, the ratio of the distances between firstly the extraction grids and the chamber and secondly the anode grid and the chamber is equal to the ratio of voltages between firstly the extraction grids and the chamber and secondly the anode grid and the chamber.
This equality makes it possible to obtain a field whose norm is homogeneous inside the vacuum gauge between the anode grid and the chamber.
The invention also concerns an ionization vacuum gauge comprising an emissive micropoint cathode source of electrons, one anode grid for collecting these electrons and an ion collector, wherein it further comprises:
one first d.c. power unit to positively polarize at Vc the cathodic electrodes of the electron source with respect to the chamber,
one second d.c. power unit for polarizing at Vg the electron extraction grids to a variable positive potential with respect to the cathodic electrodes,
one third d.c. power unit for positively polarizing at Va the electron collecting anode grid with respect to the electron extraction grid, said three power units being connected in series between the chamber and the electron collection anode grid,
one first current measuring device mounted between the second and third power units for measuring the electronic current,
a second current measuring device mounted between the ions collector and the chamber so as to measure the ionic current,
processing means connected to the first and second current measuring devices so as to calculate the pressure of the ultra-vacuum existing in the chamber on the basis of the read values of the electronic current and the ionic current.
The current measuring means are ammeters, for example.
According to one particularly advantageous embodiment of the vacuum gauge of the invention, this gauge further comprises a circuit for synchronization of the second power unit which may then be pulsed and two current measuring means, also able to be pulsed, so as to embody the functioning of the device according to a time-sampling mode.
This synchronization circuit then allows for intermittent functioning according to a time-pulsed sampling mode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, previously discussed, shows a Bayard-Alpert gauge according to the prior art.
The invention shall be more readily understood by referring to the description of embodiments given by way of non-restrictive examples, together with reference to FIGS. 2 to 4:
FIG. 2 is a diagram of one preferential embodiment of an emissive micropoint cathode used in the vacuum gauge of the invention,
FIG. 3 is a general skeleton diagram of the ionization vacuum gauge of the invention,
FIG. 4 is a general diagram of the practical mounting of the vacuum gauge of FIG. 3 together with its feeding and signal processing means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The field effect emissive cathode of FIG. 2 mainly includes on a substrate 5 a silica film 6 coated with a resistive film 7. Situated on the resistive film 7 are n cathodic electrodes 8 (with n being a whole number so that n≧1) intended for feeding of the micropoints 9. A nonconducting film 10 separates the cathodic electrodes 8 from m electron extraction grid electrodes 11 (with m a whole number so that m≧1). The electron extraction grids 11 are open-worked above each micropoint 9 so as to allow for the emission of the electrons.
The advantage of the resistive film 7 concerning the homogenization of the flux of electrons has already been explained earlier.
With reference now to FIG. 3, which is a general diagram of the ionization vacuum gauge of the invention, as in FIG. 1, this figure shows the vacuum chamber 1, the emissive cathode 2, the anode grid 3 and the ions collector 4. However and in accordance with the invention, the emissive cathode 2 is no longer a heating filament but a micropoint cathode conforming to the diagram of FIG. 2 and whose primary emission direction is situated towards the anode grid 3 and the ions collector 4.
So that the electrons are not trapped by the large surface of the chamber, the reference potential Vc (potential of the micropoints or of the cathodic electrodes) from which the electrons are emitted is greater than the potential (Ve) of the chamber. A standard value of Vc-Ve is, for example, 45 V for a grounded chamber.
The extraction grids 11 are then polarized at a variable voltage (Vg-Vc) with respect to the cathodic electrodes according to the extraction intensity it is desired to obtain. It is possible to have a mean voltage of about 90 V, which means polarizing the extraction grids 11 at a voltage Vg-Ve of 135 V with respect to the chamber, generally earthed or grounded
It has been demonstrated that the probability of collision of the electrons with the gas atoms and molecules according to their energy passes through a maximum which for most gases is between 100 and 150 eV. This is why it is advantageous to polarize the anode grid 3 at a potential (Va-Vc) equal to 130 V with respect to the cathodic electrodes 8, that is to 175 V with respect to the chamber 1.
The ratio of the chamber 1-extraction grid 11 distances to the chamber 1-anode grid 3 shall then be almost 135/175.
More generally, one could say that the ratios of the chamber 1-extraction grid 11/chamber 1-anode grid 3 distances and voltages should be equal. This precaution needs to be taken as any discontinuity of the field tends to increase the kinetic moment of the electrons subjected to it and thus tends to divert them from a strictly radial trajectory, as explained earlier.
The collector 4 is a vertical wire centered in this embodiment on the axis of the gauge, this situation not always being the case. The anode grid may be a wire helical-wound around the collector 4; for a Bayard-Alpert gauge mounted on a conventional flange, it generally has a diameter of 20 mm, a height of several centimeters (between 2 and 5) and with a pitch of several millimeters (10 to 20 spires). The distance separating the grid 3 from the micropoint cathode 2 shall then, along with the previously given potential values, be 1.7 mm. The use of a micropoint cathode makes it possible to increase the internal volume of the grid 3 with respect to a conventional gauge and thus the probability of ionizing the residual gas. This volume increase is possible owing to the possibility of bringing together the micropoint cathode which, as opposed to filaments, does not heat.
The micropoint cathode may be fixed directly with the aid of rigid electric contacts 13, which also permit voltage to be supplied. Fixing may be effected by welding with contact blocks etched on the cathode or by pressure with the aid of spring blades.
With reference now to FIG. 4, there now follows a description of an example for mounting the vacuum gauge of the invention and enabling it to be used in the best possible conditions and according to two operating modes, one continuous and the other a sampling mode according to a pulsed mode.
FIG. 4 diagrammatically shows the main elements of the ionization vacuum gauge of FIG. 3, as well as the emissive micropoint cathode of FIG. 2, the elements common to FIGS. 4, 2 and 3 bearing the same reference numbers. The device of FIG. 4 further includes three electric d.c. power units 14, 15 and 16 connected in series between the ground connected to the chamber and the electron collective anode grid 3 as follows:
The power unit 14 makes it possible to positively polarize at Vc the cathodic electrodes 8 with respect to the ground. The power unit 15 polarizes at Vg the extraction grid(s) 11 at a variable positive potential with respect to the cathodic electrodes 8, the potential difference Vg-Vc being 90 V, for example.
The power unit 16 positively polarizes at Va the anode grid 3 with respect to the extraction grids 11 so that the potential difference Va-Vc is the previously defined sought-after value. Between these two power units 15 and 16, the ammeter 17 measures the electronic current collected by the grid 3. The ammeter 18 connected to the collector 4 measures the ionic current flowing to the ground. The measurement of these two electronic and ionic currents allows for measurement of the pressure with the aid of a conventional processing unit 19.
When it is desired to have sampling operation, that is when the measurement is not made continuously but solely during a short period of time, it is possible to synchronize the power unit 15, which shall then be pulsable, and the two ammeters 17 and 18 which shall also be pulsable by means of an external synchronization unit 20. For example, it is possible to limit the measurement to 1 ms with a variable repetition frequency according to requirements, ionization only taking place during the effective time of the measurement.
In an extremely sensitive system, this makes it possible to carry out a pressure measurement and retain control of knowledge of the vacuum without disturbing the latter. Certain physical experiments require that the gauges be stopped as the electronic currents disturb the detectors.
With the embodiment of FIG. 4 and for continuous functioning, a gauge coefficient is obtained of between 25 and 30 mbar -1 (for nitrogen), which is roughly twice better than most conventional Bayard-Alpert gauges.
The particular advantage of the mounting shown on FIG. 4 is of having the qualities of the Bayard-Alpert gauges whilst being freed from the problems inherent in the use of a hot cathode. Its main advantages with respect to the performances of a Bayard-Alpert gauge may be summed up as follows:
natural directivity of emission in a solid angle of π/3 centered on the normal line to the plane of the cathode and emission of electrons with a high initial speed (energy about 100 eV). As a result, centralization of the beam clearly depends less on the positioning of the source in the field.
Moreover, due to their high initial speed, the electrons penetrate into the zone delimited by the grid without being trapped by the latter, which increases the average length of the trajectories of the electrons and thus sensitivity of the gauge.
The high rigidity of the micropoint network moreover ensures an excellent mechanical stability and the cathode used ensures good regularity of the emission. All these characteristics contribute in clearly improving the stability and reproductibility of the measurements:
improvement of emissivity by the surface unit and good natural rigidity. Thus, with an equivalent emission current, the surface of the cathode is smaller than that of the filament, which makes it possible to have the best possible localized source,
apart from sampling functioning, the reaction speed of the source makes it possible to halt the measurement should a problem occur (for example, sudden rise in pressure) with effectiveness within an extremely short period of time.
Finally, there is a certain number of advantages directly linked to the replacement of a hot cathode by a cold cathode:
no infrared radiation of the source, which allows for use in a cryogenic atmosphere,
no ultraviolet radiation of the source and thus reduction of the Rontgen effect,
no creation of species of the same family by heating. The ions are thus created solely via impact with the electrons; the measurement is then more accurate,
no filament degassing and thus obtaining a more accurate measurement after ignition,
no evaporation of tungsten or pollutants, such as carbon monoxide.
All these phenomena are directly linked to heating of the filament in conventional Bayard-Alpert gauges.
suppression of thorium, a weakly radioactive and chemically dangerous element used for the production of weak electric affinity filaments, that is requiring a relatively weak work function for extracting the electrons. This compound is often used to improve the too weak emissivity of pure tungsten filaments,
low consumption, (reduction of consumption by a factor of between 10 and 100). | Ionization vacuum gauge comprising, like Bayard Alpert gauges, in a chamber (1) containing an extremely low pressure atmosphere, whose ultra-vacuum degree it is desired to be measured, an electron source cathode (2), a grid (3) for collecting these electrons and surrounding a collector (4) of ions resulting from the impact of the electrons on the gas molecules of the extremely low pressure atmosphere, wherein the electron source is a cold micropoint cathode. | 7 |
This application relates to U.S. provisional patent application Nos. 60/003,048, filed Aug. 31, 1995, and 60/008,628, filed Dec. 12, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus and methods for handling items for purchase from a store having a checkout counter. More specifically, the present invention relates to tracks for storing divider bars used to separate consumer purchases awaiting checkout. The tracks can be fitted to conveyor-type market checkout counters to accommodate various types of checkout divider bars.
2. Description of the Related Art
Many shopping stores, such as supermarkets, utilize checkout counters having conveyors. The conveyor transports the items each customer has selected for purchase from a receiving end of the conveyor toward a cash register station. Typically, the conveyor is a belt, usually made from rubberized fabric. Usually several customers can place their selected orders on the conveyor at one time.
In order to prevent intermingling of goods between customers' orders, divider bars are provided that can be placed after each customer's group of items on the conveyor. The divider bars are often made of molded plastic, and may have advertisements or other printed information displayed on them. During periods of non-use, the divider bars are usually stored in a smooth track alongside the conveyor.
As the goods move along with the conveyor and are checked through the cash register station, each divider bar in turn reaches the cashier. The cashier generally returns the divider bar to the track running alongside the conveyor. The divider bars slide along the track, usually as a result of being pushed by other divider bars, so that each divider bar eventually returns to the receiving end of the conveyor to await use by another customer.
Pursuant to applicant's U.S. Pat. No. 5,450,926, the entire disclosure of which is incorporated herein by reference, a divider bar is provided that carries and displays merchandise to be purchased. The patented display/divider bar can be filled with items such as candy, gum, novelty items, etc. The display/divider bar, and/or its contents, can be purchased along with the customer's other goods. The display/divider bar advantageously is larger than conventional divider bars presently in use, and does not fit in the storage tracks currently being used.
As a result, the need exists for a track that can be installed on conveyor checkout counters and that can accommodate the new display/divider bars. Further, the need exists for wider tracks that can be fitted to existing, conventional checkout counters without the need for removing the previously-installed, conventional tracks. In addition, the need exists for a storage track having advertising display carriers and wider surfaces that can be used for the effective presentation of advertising material.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art noted above by providing a storage track that can accommodate a larger display/divider bar. The track can be incorporated as part of a newly-installed checkout counter. Alternatively, the track fits readily on an existing, conventional checkout counter, either by removing a previously-installed track and replacing it with the track of the present invention, or by installing the track of the present invention over the previously-installed track.
Advantageously, the visible surfaces of the divider bar track can be used for displaying advertisements at the checkout counter. Accordingly, the track includes attachments for securing advertising displays to the divider bar track, either permanently or, according to a preferred embodiment, temporarily.
A fixture is also included for installation of the track on the checkout counter. Track installation also can be permanent or temporary. According to a preferred embodiment, installation of the track is temporary. The track is interchangeable with a similar track previously installed on the checkout counter, so that advertising displays can be updated or changed, as discussed more fully below in conjunction with a preferred method of advertising according to the present invention.
According to another preferred embodiment, the track of the present invention includes a bottom panel having a width, a front edge and a rear edge, a rear wall adjoining the bottom panel on the rear edge, and a front wall adjoining the bottom panel on the front edge. The track further includes a fixture for securing the track to a surface. In one embodiment, the track is secured permanently, using screws, for example. Alternatively, the track can be secured more temporarily, using hook-and-loop fasteners, for example. By temporarily securing the track, easy removal is made possible for cleaning, or for substitution of the track with another, for the purpose of updating advertising displays, for example.
In a preferred embodiment, the track has a notch running lengthwise along the bottom panel that fits over the wall of a previously-installed, conventional track. The notch divides the present invention lengthwise into two tracks, a smaller track that fits into the previously-installed, conventional narrow track, and a wider track. The wider track accommodates the applicant's patented display/divider bars, and typically extends over the conveyor. Preferably, the portion of the bottom panel accommodates the wider display/divider bars so that they rest flat in the track. For example, the track can be at least three inches in width.
The present invention also provides a method of fitting a divider bar track onto a checkout counter having a conveyor with a conventional, previously-installed track. The method includes the step of installing a track for a checkout counter display/divider bar over a previously-installed track. The track is secured to the checkout counter, either temporarily or permanently, preferably by fasteners attached, for example, to a rear wall adjoining the bottom panel on the rear edge.
The present invention also includes a method of displaying advertisements at a checkout counter. The method includes attaching an advertising display on a divider bar track, and installing the track on the checkout counter. Installing the track comprises interchanging the track with a previously-installed track of the present invention.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an end view schematic of a divider bar track according to a preferred embodiment of the present invention.
FIG. 2 shows an end view schematic of a divider bar track according to an alternative preferred embodiment of the present invention.
FIG. 3 shows a schematic side view of a divider bar track according to a preferred embodiment of the present invention.
FIG. 4 shows a schematic side view of a divider bar track according an alternative preferred embodiment of the present invention.
FIG. 5 is an end view of a checkout counter showing the placement of divider bar tracks according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1 and 2, end views of divider bar tracks 2 according to the present invention are shown. The track includes a bottom panel 4, a rear wall 6 joined perpendicularly to the bottom panel toward its rear edge, and a front wall 8 joined perpendicularly to the bottom panel on the front edge thereof.
The tracks 2 of the present invention are shown installed over a previously-installed, conventional track 10. The conventional track 10 is secured to counter 12, adjacent conveyor belt 14, shown in schematic cross-section. Alternatively, the tracks can be installed so as to replace the conventional track, as discussed below.
According to the embodiment shown in FIG. 1, the track 2 of the present invention includes a notch 16 that fits over the front wall of previously-installed, conventional track 10. Accordingly, bottom panel 4 of track 2 is divided into two tracks, the narrower track accommodating the known divider bars, for example, and the wider track accommodating wide divider bars. As shown in FIG. 1, the bottom panel is suspended approximately 1/8" above conveyor 14.
Track 2 can be secured either permanently or temporarily to the checkout counter using attachments 11. Attachments 11 can be relatively permanent, such as screws, nails, bolts, plastic anchors, adhesive, or any other type of permanent fixation system. According to an alternative embodiment, attachments 11 are for temporary fixation. Illustrative temporary attachments include hook-and-loop fasteners, double-sided tape, snaps, clips, magnets, or a press-to-fit arrangement, for example.
Advantageously, when tracks 2 are attached temporarily, the tracks can be removed readily for replacement. In a particularly preferred embodiment, tracks 2 carry advertising information displayed on the various surfaces visible to the customer. The advertisement copy can be held by various means on the track, either permanent or temporary. Illustrative examples of attachments for the advertisements to the track include hook-and-loop fasteners, double-sided tape, snaps, clips, magnets, or press-to-fit arrangements. Preferably, the advertisements are held in slots 17 formed behind transparent panels. The transparent panels can be formed of plastic or glass, for example.
Accordingly, a transparent panel is positioned to create a slot in which an advertising display can be positioned. For example, referring to FIG. 2, above bottom panel 4 transparent panel 18 is positioned to protect the advertisement and to allow the customer to read the advertisement held in slot 17. Similarly, the outer side of wall 8 is covered with another panel 18. Alternatively, the advertisement display carrier could take the form of paired notches 19 in which the advertisements are positioned and held for display. See FIGS. 1 and 2.
These advertisements can be sold on a cyclical basis, for example, for four-week periods. The temporarily-installed tracks are then readily detached and replaced at the end of each advertising cycle with a fresh set of displays having new advertisements held thereon. Alternatively, the tracks could remain in place permanently, and the advertising could be replaced.
The tracks of the present invention typically are made of metal. According to a preferred embodiment, a transparent panel is disposed above a visible surface of the track so as to create a protected space into which an advertisement can be inserted. Alternatively, the track can be made of a transparent material such as plastic, or a combination of metal and plastic, or other materials having sufficient durability.
Advertisements can printed on various materials such as paper or plastic. Where the advertisement may be exposed to damage, such as by moving divider bars, groceries, or customers, a material that will not be effected by such exposure is used.
Referring to FIGS. 3 and 4, tracks 2 are shown schematically from the side, having been installed on a counter 12 above conveyor 14 which is driven by rollers 20. In order to prevent items from becoming lodged between conveyor 14 and track 2, or between track 2 and the edge of counter 12, a guard 21 is provided as shown in FIG. 3. Guard 21 extends under the edge of counter 12 and above conveyor 14 to prevent items from becoming trapped.
A similar type of guard is shown in FIG. 4. Guard 22 is shown extending above and beyond the edge of counter 12. Guards 21, 22 can be formed as an integral extensions of track 2, or as separately-attached pieces.
Referring to FIG. 5, the track of the present invention, shown schematically, is installed on either side of the conveyor. The end view is shown of a display divider 24 stored in one of the tracks 2. As shown, tracks can be installed on both sides of the conveyor, to provide increased visibility both of advertisements provided on the tracks and of divider bars containing purchasable merchandise stored in the tracks.
FIG. 5 also illustrates the tracks of the present invention installed directly onto counter 12 above conveyor belt 14 (shown schematically). If desired, previously-installed track 26 can remain in place for storage of conventional divider bars. The installation can be permanent or temporary, using various fasteners 11, as noted above.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is to be limited not by the specific disclosure herein, but only by the appended claims. | A track (2) for storing divider bars (24) used on a checkout counter (12) having a conveyor (14). The track (2) can be fitted over or replace a previously-installed track (10), and can store display/divider bars of much greater width than those presently in use. The wider surfaces of the new track also provide areas on which advertising can be displayed. The new tracks can be secured in place temporarily for ease of replacement by tracks displaying or holding updated advertising information. | 0 |
CROSS-REFERENCE
[0001] The present application claims priority under 35 U.S.C. § 119 of Japanese Patent Application No. 2005-260028, filed on Sep. 8, 2005, the entire content of which is expressly incorporated by reference herein.
FIELD
[0002] The present invention pertains to an engine starting control device for a hybrid vehicle that constitutes a hybrid drive system in which a clutch having an adjustable torque capacity is disposed between the engine and the motor/generator and a transmission that changes the gearshift ratio continuously or in stages is disposed between the motor/generator and the drive wheels.
BACKGROUND
[0003] Conventionally, (e.g., Japanese Unexamined Patent Application Publication No. H11-82260) an engine, in a stopped state, is lift-started by temporarily releasing a second clutch disposed between a rotating motor/generator and the drive wheels. Then, a first clutch disposed between the engine and motor/generator is engaged to produce a drag torque in the first clutch that is used to lift start the engine. This procedure acts to reduce a torque fluctuation that otherwise takes place at the instant when the first clutch is engaged for coupling the engine to motor/generator for lift starting the engine while second clutch is engaged.
SUMMARY
[0004] In the case of the aforementioned engine starting control technology for a hybrid vehicle, when lift-starting the engine, one possible scenario is that the engine is lift-started in the stopped state while the motor/generator is rotating at a high rpm. In such a case, a problem occurs in which the rotational difference in the first clutch disposed between the engine and the motor/generator increases and heat is generated in the first clutch due to the slip engagement associated with a large amount of slip, resulting in possible deterioration of the durability of the first clutch.
[0005] The present invention was contrived in light of the aforementioned problem and its objective is to provide an engine starting control device for a hybrid vehicle that can suppress the deterioration of the durability of the first clutch and improve fuel consumption, while at the same time, ensuring a rotational state in which the engine can be started when switching modes to the hybrid operation mode when driving in the electric operation mode.
[0006] In order to achieve the aforementioned objective, the present invention pertains to an engine starting control device for a hybrid vehicle that constitutes a hybrid drive system in which a first clutch capable of changing the torque capacity is disposed between the engine and the motor/generator and a transmission that changes the gearshift ratio continuously or in stages is disposed between the motor/generator and the drive wheels, and that is equipped with an engine starting control means that lift-starts the engine while it is in the stopped state using the drag torque of the first clutch when there is a request to switch modes to the hybrid operation mode, which operates using the power from the engine and motor/generator as the power source, when driving in the electric operation mode in which the first clutch is released and the vehicle operates using only the motor/generator as the power source; where the engine starting control means controls the gearshift ratio of the aforementioned transmission so as to lower the transmission input rotation speed when switching modes to the hybrid operation mode when driving in the electric operation mode.
[0007] Therefore, according to the engine starting control device for a hybrid vehicle pertaining to the present invention, the engine starting control means controls the gearshift ratio of the transmission so as to lower the transmission input rotation speed when switching modes to the hybrid operation mode in accordance with the decrease in the battery charge capacity, the increase in the vehicle speed, or the drive force request made by the driver, for example, when driving in the electric operation mode. Lowering the transmission input rotation speed by controlling the gearshift ratio of the transmission when switching modes to the hybrid operation mode acts to reduce the difference between the rotational speed of the motor/generator and the rotational speed of the engine compared to when no control of the gearshift ratio of the transmission is performed. This reduces the rotational difference across the clutch located between the motor/generator and the engine and thus reduces heat generation in the clutch, thereby reducing the deterioration of the durability of the clutch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an overall system diagram of a rear-wheel drive hybrid vehicle in which the engine starting control device pertaining to Embodiment 1 has been applied.
[0009] FIG. 2 is a control block diagram showing the arithmetic-processing program for the integrated controller pertaining to Embodiment 1.
[0010] FIG. 3 is a diagram showing one example of the target drive force map used for the target drive force calculation performed at the target drive force calculation unit shown in FIG. 2 .
[0011] FIG. 4 is a diagram showing one example of the target mode map used for selecting the target mode by the mode selection unit shown in FIG. 2 .
[0012] FIG. 5 is a diagram showing one example of the target battery charge/discharge capacity map used to calculate the target battery charge/discharge power by the target battery charge/discharge calculation unit shown in FIG. 2 .
[0013] FIG. 6 is a flowchart showing the arithmetic processing used to determine each operation point by the operating point command unit shown in FIG. 2 .
[0014] FIG. 7 is a diagram showing one example of the shift map used for the target automatic transmission shift calculation step shown in FIG. 6 .
[0015] FIG. 8 is a diagram showing one example of the operation point map for when the target mode set according to the mode-setting step shown in FIG. 6 transitions from a EV mode to an HEV mode.
[0016] FIG. 9 is a diagram showing one example of the maximum engine torque map in relation to the engine rotation speed used for the target engine torque calculation step shown in FIG. 6 .
[0017] FIG. 10 is a diagram showing three mode transition patterns for when transitioning from an EV mode to a HEV mode for the engine starting control pertaining to Embodiment 1.
[0018] FIG. 11 is a time chart for the engine starting process that accompanies an upshift for the engine starting control device pertaining to Embodiment 1.
[0019] FIG. 12 is a time chart for the engine starting process that does not accompany a shift change for the engine starting control device pertaining to Embodiment 1.
[0020] FIG. 13 is a time chart for the engine starting process that accompanies a downshift for the engine starting control device pertaining to Embodiment 1.
[0021] FIG. 14 is a diagram showing one example of the operation point map for when a request is made for an upshift when the target mode set at the mode-setting step shown in FIG. 6 transitions from the EV mode to the HEV mode in relation to the engine starting control device pertaining to Embodiment 2.
DETAILED DESCRIPTION
[0022] Below is provided a description of the most favorable embodiment for realizing the engine starting control device for a hybrid vehicle pertaining to the present invention, based on Embodiments 1 and 2 shown in the Drawings.
Embodiment 1
[0023] First is provided an explanation of the constitution of the drive system for a hybrid vehicle. FIG. 1 is an overall system diagram of a rear-wheel drive hybrid vehicle in which the engine starting control device pertaining to Embodiment 1 has been applied. As shown in FIG. 1 , the drive system for the hybrid vehicle pertaining to Embodiment 1 comprises engine E, flywheel FW, first clutch CL 1 , motor/generator MG, second clutch CL 2 , automatic transmission AT, propeller shaft PS, differential DF, left drive shaft DSL, right drive shaft DSR, left rear wheel RL (drive wheel) and right rear wheel RR (drive wheel). FL refers to the left front wheel and FR refers to the right front wheel.
[0024] Engine E is either a gasoline or a diesel engine, where the valve opening of the throttle valve is controlled based on a control command from engine controller 1 , which is described below. On the engine output shaft is provided flywheel FW.
[0025] The first clutch CL 1 is the clutch disposed between the engine E and the motor/generator MG, and the engagement/release, including the slip engagement and slip release, are controlled by means of a control oil pressure generated by first clutch oil pressure unit 6 in accordance with the control command from the first clutch controller 5 described below.
[0026] The motor/generator MG is a synchronous type motor/generator that has a permanent magnet embedded in its rotor and a stator coil wrapped around its stator and is controlled by applying a three-phase alternating current generated by inverter 3 in accordance with the control command from the motor controller 2 described below. Motor/generator MG receives the supply of electric power from the battery 4 and operates as an electric motor that performs rotary drive (hereafter this state is referred to as “power running”), but can also function as a generator that generates electromotive force at both ends of the stator coil when the rotor rotates by means of an external force in order to charge battery 4 (hereafter this operating state is referred to as “regenerative power”). The rotor for motor/generator MG is linked to the input shaft of automatic transmission AT via a damper not shown in the drawing.
[0027] The second clutch CL 2 is the clutch disposed between the motor/generator MG and the right and left rear wheels RL and RR. The engagement/release of second clutch, including the slip engagement and slip release, are controlled by means of a control oil pressure generated by second clutch oil pressure unit 8 in accordance with the control command from the AT controller 7 described below.
[0028] The automatic transmission AT is a transmission that automatically switches the gearshift ratio in steps, such as 5 forward speeds and 1 reverse speed or 6 forward speeds and 1 reverse speed, in accordance with the vehicle speed and the accelerator pedal opening, and the second clutch CL 2 is not an exclusive clutch that has been newly added, but utilizes a number of friction engagement elements from a plurality of friction engagement elements that are engaged at each gear shift in the automatic transmission AT. Furthermore, the output shaft of the automatic transmission AT is linked to the left and right rear wheels RL and RR via propeller shaft PS, differential DF, left drive shaft DSL and right drive shaft DSR.
[0029] A multi-plate wet clutch that uses a proportional solenoid to continuously control the oil flow rate and oil pressure may be used for the first and second clutches CL 1 and CL 2 . In the present hybrid drive system, there are two operating modes that operate in accordance with the engagement/release of the first clutch CL 1 : an electric operation mode (hereafter referred to as “EV mode”) is used when the first clutch CL 1 is in a released state and when operating using only the power from motor/generator MG, and a hybrid operation mode (hereafter referred to as HEV mode) is used when the first clutch CL 1 is an engaged state and when operating using power from the engine E and the motor/generator MG.
[0030] Next is provided an explanation of the control system for a hybrid vehicle. As shown in FIG. 1 , the control system for the hybrid vehicle pertaining to Embodiment 1 comprises engine controller 1 , motor controller 2 , inverter 3 , battery 4 , first clutch controller 5 , first clutch oil pressure unit 6 , AT controller 7 , second clutch oil pressure unit 8 , brake controller 9 , and integrated controller 10 . Engine controller 1 , motor controller 2 , first clutch controller 5 , AT controller 7 , brake controller 9 , and integrated controller 10 are connected via a CAN communication line that allows for their mutual exchange of information.
[0031] Engine controller 1 inputs the engine rotation speed information from engine rotation speed sensor 12 and outputs the command that controls the engine operating points (Ne, Te) to a throttle valve actuator, not shown in the drawing, in accordance with the target engine torque command from integrated controller 10 . The information pertaining to the engine rotation speed Ne is supplied to the integrated controller 10 via the CAN communication line.
[0032] Motor controller 2 inputs the information from resolver 13 , which detects the rotation position of the rotor of motor/generator MG and outputs the command that controls the motor operating points (Nm, Tm) of motor/generator MG to inverter 3 in accordance with the target motor/generator torque command from integrated controller 10 . Motor controller 2 monitors the battery SOC, which indicates the charged state of the battery 4 , and the battery SOC information is not only used for the control information for motor/generator MG, but is also supplied to integrated controller 10 via the CAN communication line.
[0033] First clutch controller 5 inputs the sensor information from first clutch oil pressure sensor 14 and first clutch stroke sensor 15 and outputs the command that controls the engagement/release of first clutch CL 1 to first clutch oil pressure unit 6 in accordance with the first clutch control command from integrated controller 10 . The first clutch stroke information C 1 S is supplied to integrated controller 10 via the CAN communication line.
[0034] The AT controller 7 inputs the sensor information from accelerator pedal opening sensor 16 , vehicle speed sensor 17 , and second clutch oil pressure sensor 18 and outputs the command that controls the engagement/release of the second clutch CL 2 to the second clutch oil pressure unit 8 inside of the AT oil pressure control valve in accordance with the second clutch control command from integrated controller 10 . The accelerator pedal opening AP and vehicle speed VSP information are supplied to integrated controller 10 via the CAN communication line.
[0035] Brake controller 9 inputs the sensor information from wheel speed sensor 19 , which detects the wheel speed of each of the 4 wheels, and brake stroke sensor 20 and performs regeneration collaborative brake control in accordance with the regeneration collaborative command from integrated controller 10 so as to compensate for the insufficient mechanical braking force (fluid pressure braking force or motor braking force) when regenerative braking force alone is not sufficient in relation to the required braking force requested from the brake stroke BS when braking is performed by pressing on the brake pedal.
[0036] Integrated controller 10 manages the energy consumed by the entire vehicle and assumes the functions necessary to run the vehicle at the maximum efficiency, and therefore inputs the information obtained from motor rotation speed sensor 21 that detects the motor rotation speed Nm, second clutch output rotation speed sensor 22 that detects the second clutch output rotation speed N 2 out, second clutch torque sensor 23 that detects the second clutch torque TCL 2 , and the information obtained via the CAN communication line. Further, integrated controller 10 performs operation control of engine E by means of a control command sent to engine controller 1 , operation control of motor/generator MB by means of a control command sent to motor controller 2 , engagement/release control of first clutch CL 1 by means of a control command sent to first clutch controller 5 , and engagement/release control of second clutch CL 2 by means of a control command sent to AT controller 7 .
[0037] Below is provided an explanation of the control calculated by integrated controller 10 of Embodiment 1 using the block diagram shown in FIG. 2 . This calculation is performed at integrated controller 10 in a control cycle consisting of 10 msec intervals, for example.
[0038] Integrated controller 10 comprises target drive force calculation unit 100 , mode selection unit 200 , target battery charge/discharge calculation unit 300 , operating point command unit 400 , and transmission control unit 500 . Target drive force tFo 0 is calculated at the target drive force calculation unit 100 from the accelerator pedal opening APO and vehicle speed VSP using the target drive force map shown in FIG. 3 . The target mode is calculated at aforementioned mode selection unit 200 from the accelerator pedal opening APO and the vehicle speed VSP using the EV-HEV selection map shown in FIG. 4 . However, if the battery SOC is less than a prescribed value, the HEV mode is mandatorily set as a target mode. The target battery charge/discharge power tP is calculated at aforementioned target battery charge/discharge calculation unit 300 from the battery SOC using the target battery charge/discharge capacity map shown in FIG. 5 . The transitional target engine torque, target motor/generator torque, target second clutch torque capacity, target automatic transmission shift, and first clutch solenoid current command are calculated at aforementioned operating point command unit 400 from the accelerator pedal opening APO, the target drive force tFo 0 , the target mode, the vehicle speed and the target battery charge/discharge as the attainable targets for the operating points of these values.
[0039] The solenoid valve inside of the automatic transmission AT is drive controlled at aforementioned transmission control unit 500 from the target second clutch torque capacity and the target automatic transmission shift so as to achieve these values.
[0040] FIG. 6 is a flowchart showing the flow of the arithmetic process for calculating the operating point command executed at the operating point command unit of integrated controller 10 , and provided below is an explanation for each step of this process.
[0041] At step S 401 , the transitional target drive force tFo obtained by performing a prescribed tuning on the target drive force tFo 0 is calculated, and the process proceeds to step S 402 . The transitional target drive force tFo can be set from the output of a low-pass filter that has a prescribed time constant with the target drive force tFo 0 as its input, for example.
[0042] After the transitional target drive force calculation has been performed at step S 401 , equation (1) is used at step S 402 to calculate the target input torque tTin of the automatic transmission AT.
tTin=tFo×rt/if/iG (1)
where ‘rt’ is the radius of the tire, ‘if’ is the final gear ratio, and ‘iG’ is the gear ratio of the actual automatic transmission shift in current time.
[0043] After the target input torque has been calculated at step S 402 , at step S 403 , the shift map shown in FIG. 7 is used to calculate the target automatic transmission shift from the accelerator pedal opening APO and the vehicle speed VSP, and the process proceeds to step S 404 . In FIG. 7 , the solid line represents the upshift line and the broken line represents the downshift line.
[0044] FIG. 8 shows an example of an upshift line from the 4 th speed to the 5 th speed and a downshift line from the 5 th speed to the 4 th speed. When changing the accelerator pedal opening from point A to point A′, which cross over the downshift line, the engine is started in conjunction with a downshift. On the other hand, when a request is made to start the engine with a low battery SOC while operating steadily in the EV mode at point C, or when a request is made to start the engine due to an increase in the vehicle speed, such as the case for point B to point B′, the engine is started without making a shift change. However, the target automatic transmission gear ratio is set so that the automatic transmission input rotation speed is higher than the rotation speed in which the engine can operate for the current time vehicle speed.
[0045] After the target automatic transmission shift is calculated at step S 403 , at step S 404 , the mode selection is performed in accordance with the target mode and the process proceeds to step S 405 .
[0046] Normally, the vehicle operates in either the EV mode or the HEV mode. If the target mode becomes the HEV mode while operating in the EV mode, the mode is selected in accordance with the mode transition map shown in FIG. 10 , and the switching operation from the EV mode to the HEV mode that accompanies the starting of the engine is performed.
[0047] After the mode is set in step S 404 , at step S 405 , if operating in the HEV mode, the following equation is used to calculate the ideal engine torque tTe 0 from the target input torque tTin, the automatic transmission input rotation speed Nin, and the engine rotation speed Ne:
tTeo =( tTin×Nin−tP )/ Ne (2)
Then, the maximum engine torque that is limited by the ideal engine torque tTeo is set as the target engine torque tTe in accordance with the engine rotation speed Ne using the maximum engine torque map shown in FIG. 9 . In addition, when operating in the EV mode, the target engine torque tTe is set to zero.
[0048] After the target engine torque is calculated at step S 405 , at step S 406 , if operating in either the EV mode or the HEV mode, the target motor/generator torque tTm is calculated using the following equation:
tTm=tTin−tTe (3)
If this takes place while switching modes, the target motor/generator torque is determined according to the operation performed while switching modes described below.
[0049] After the target motor/generator torque is calculated at step S 406 , at step S 407 , if operating in the EV mode, the target first clutch torque capacity is set to zero, and if operating in the HEV mode, the target first clutch torque capacity is set to the maximum value. If this takes place while switching modes, the target first clutch torque capacity is determined according to the operation performed while switching modes described below.
[0050] After the target first clutch torque capacity is calculated at step S 407 , at step S 408 , if operating in the EV mode, the target second clutch torque capacity tcTc 12 is set as the maximum drive force equivalent evTmax for the EV mode, and if operating in the HEV mode, the target second clutch torque capacity tcTc 12 is set at the maximum value. If this takes place while switching modes, the target second clutch torque capacity tcTc 12 is determined according to the operation performed while switching modes described below and the process ends.
[0051] Next is provided an explanation of the operation. An explanation is provided of the switching control operation from the EV mode to the HEV mode that accompanies the starting of the engine using the mode transition map shown in FIG. 10 and the time charts shown in FIG. 11 through FIG. 13 .
[0052] FIG. 11 is the time chart for the starting of the engine that accompanies an upshift, FIG. 12 is the time chart for the starting of the engine that does not accompany a shift change, and FIG. 13 is the time chart for the starting of the engine that accompanies a downshift. All three of these drawings are time charts that show, in order from the top, the accelerator pedal opening APO, the rotation speed (solid line: motor/generator, broken line: automatic transmission input, dot-dashed line: engine), the torque (solid line: motor/generator, dot-dashed line: engine), the clutch torque capacity (broken line: the first clutch, solid line: the second clutch), and the drive force.
[0000] When a request to transition to the HEV mode that accompanies an upshift is made.
[0053] An explanation is now provided for the starting of the engine that accompanies an upshift using the mode transition map shown in FIG. 10 and the time chart shown in FIG. 11 .
[0054] As shown in FIG. 10 and FIG. 11 , when a request is made to transition to the HEV mode that accompanies an upshift while operating in the EV mode, the process transitions to mode 2301 a , and an upshift is performed first. When this takes place, in order to prevent a decrease in the drive force due to a switch in the engagement elements during the torque phase of the upshift, the motor/generator torque is raised so as to synchronize with the switch in the engagement elements. In addition, the change in the gearshift ratio that takes place during the inertia phase of the upshift can be assisted by the motor/generator torque.
[0055] Then, after the upshift is completed, the process transitions to mode 2302 a and the lift-start of engine E by first clutch CL 1 is performed. When this takes place, the drag torque of first clutch CL 1 is compensated for by motor/generator MG and the decrease in the drive force is suppressed. However, it is not necessary to make the point at which the upshift is completed and the point at which the engagement of first clutch CL 1 begins coincide with one another, and the lift-start of engine E by first clutch CL 1 can be performed before the upshift is completed.
[0000] When a request to transition to the HEV mode that does not accompany a shift change is made
[0056] An explanation is provided for the starting of the engine that does not accompany a shift change using the mode transition map shown in FIG. 10 and the time chart shown in FIG. 12 .
[0057] As shown in FIG. 10 and FIG. 12 , when a request is made to transition to the HEV mode that does not accompany a shift change while operating in the EV mode, the process transitions to mode 2301 b , and the lift-start of engine E by first clutch CL 1 is performed. When this takes place, the drag torque of first clutch CL 1 is compensated for by motor/generator MG and the decrease in the drive force is suppressed.
[0000] When a request to transition to the HEV mode that accompanies a downshift is made
[0058] An explanation is provided for the starting of the engine that accompanies a downshift using the mode transition map shown in FIG. 10 and the time chart shown in FIG. 13 .
[0059] As shown in FIG. 10 and FIG. 13 , when a request is made to transition to the HEV mode that accompanies a downshift while operating in the EV mode, the process transitions to mode 2301 c , and the lift-start of engine E by first clutch CL 1 is performed first. When this takes place, the drag torque of first clutch CL 1 is compensated for by motor/generator MG and the decrease in the drive force is suppressed. Then, after the starting of engine E is has been completed and first clutch CL 1 has been engaged, the process transitions to mode 2302 c and a downshift is performed. At this point, the change in the gearshift ratio that takes place during the inertia phase of the downshift can be assisted by the motor/generator torque. In addition, the increase in the drive force that takes place during the torque phase of the downshift, as shown in FIG. 13 , is permitted when a request to raise the drive force is made by pressing on the accelerator pedal.
[0000] The Engine Starting Control Operation
[0060] Conventionally, when lift-starting an engine in the stopped state using the drag torque of the first clutch disposed between the engine and motor/generator, in order to prevent the torque fluctuation that takes place when the engine is lift-started and at the instant in which the first clutch engages from being transferred to the output shaft, the engine is lift-started with the second clutch disposed between the motor/generator and the drive wheels in a temporarily released state.
[0061] However, when lift-starting the engine in such a manner, one possible scenario is that the engine is lift-started in the stopped state while the motor/generator (=transmission input axis) is rotating at a high rpm, and in such a case, the rotational difference in the first clutch disposed between the engine and the motor/generator increases and heat is generated in the first clutch due to the slip engagement accompanied by a large amount of slip, resulting in possible deterioration of the durability of the first clutch.
[0062] On the other hand, for the engine starting control device pertaining to Embodiment 1, by controlling the gearshift ratio of automatic transmission AT so that the transmission input rotation speed becomes close to the engine rotation speed that is possible for engine operation in a range in which the transmission input rotation speed is the same or more than the rotation speed that is possible for engine operation when transitioning to the HEV mode while operating in the EV mode, the deterioration of the durability of first clutch CL 1 can be suppressed, while at the same time ensuring a rotational state in which engine E can be started, and the fuel consumption can also be improved.
[0063] In other words, for the engine starting control device pertaining to Embodiment 1, the operating point command unit 400 of integrated controller 10 (the engine starting control means) controls the gearshift ratio of the automatic transmission AT so that the transmission input rotation speed becomes close to the engine rotation speed that is possible for engine operation in a range in which the transmission input rotation speed is the same or more than the rotation speed that is possible for engine operation when transitioning modes to the HEV mode in accordance with the decrease in the battery SOC, the increase in the vehicle speed, or the drive force request made by the driver when pressing down on the accelerator pedal, for example, when driving in the EV mode.
[0064] At this point, by restricting the transmission input rotation speed (=motor/generator rotation speed) to be within a range that is equal to or greater than the rotation speed that is possible for engine operation, a rotational state in which engine E can be started from a stopped state using the drag torque of first clutch CL 1 can be ensured.
[0065] In addition, when the transmission input rotation speed is higher than the rotation speed that is possible for engine operation, the gear position can be changed to the low rotation speed side by means of an upshift so that compared to when the gearshift ratio of the transmission is not controlled at all when starting the engine, the rotational difference (the difference between the motor/generator rotation speed and the engine rotation speed) in the first clutch CL 1 that takes place when lift-starting engine E can be reduced and the deterioration of the durability of first clutch CL 1 due to the generation of heat in the clutch can be suppressed.
[0066] Furthermore, since the motor/generator MG is more efficient at the high rotation-low torque side, and the engine E is more efficient at the low rotation-high torque side, when transitioning from the EV mode to the HEV mode, fuel consumption can be improved by controlling the gearshift ratio to be close to the rotation speed that is possible for engine operation and by suppressing the engine rotation speed to low rotation.
[0067] The engine starting control means for the engine starting control device pertaining to Embodiment 1 transitions from the EV mode to upshift mode 2301 a to the engine starting mode 2302 a to the HEV mode in conjunction with an upshift request, as shown in FIG. 10 , when transitioning modes to the HEV mode due to a decrease in the battery SOC or an increase in the vehicle speed while operating in the EV mode, after which it upshifts automatic transmission AT and then completes the engagement of first clutch CL 1 . Therefore, the rotational difference of first clutch CL 1 can be minimized during the time period until the lift-start of engine E is completed and the deterioration of the durability of the clutch due to heat generation in first clutch CL 1 can be further suppressed.
[0068] The engine starting control means for the engine starting control device pertaining to Embodiment 1 transitions from the EV mode to upshift mode 2301 a to engine starting mode 2302 a to the HEV mode in conjunction with an upshift request, as shown in FIG. 10 , when transitioning modes to the HEV mode due to a decrease in the battery SOC or an increase in the vehicle speed while operating in the EV mode, after which it completes the upshift at automatic transmission AT, starts the engagement of first clutch CL 1 , and lift-starts engine E while it is in the stopped state by means of the drag torque of said first clutch CL 1 . Therefore, the rotational difference of first clutch CL 1 can be minimized from the starting point of the lift-start of engine E and the deterioration of the durability of the clutch due to heat generation in first clutch CL 1 can be even further suppressed.
[0069] The engine starting control means for the engine starting control device pertaining to Embodiment 1 raises the torque of motor/generator MG in accordance with the decrease in the torque transfer ratio in automatic transmission AT that accompanies the upshift of the gearshift ratio of automatic transmission AT, as shown in the motor/generator torque characteristics at upshift mode 2301 a in FIG. 11 . Therefore, the decrease in the drive force due to the upshift is suppressed and the continuity of the drive force can be ensured, as shown by the drive force characteristics in FIG. 11 .
[0070] The engine starting control means for the engine starting control device pertaining to Embodiment 1 transitions from the EV mode to engine starting mode 2301 b to the HEV mode, as shown in FIG. 10 , when not accompanied by a gear change request and when transitioning modes to the HEV mode due to a decrease in the battery SOC or an increase in the vehicle speed while operating in the EV mode, after which it immediately begins the engagement of first clutch CL 1 , and lift-starts engine E while it is in the stopped state by means of the drag torque of said first clutch CL 1 . Therefore, when transitioning modes from the EV mode to the HEV mode, said mode transitioning from the EV mode to the HEV mode can be completed with favorable responsiveness while suppressing the generation of heat in first clutch CL 1 with a minimal rotational difference in first clutch CL 1 .
[0071] The engine starting control means for the engine starting control device pertaining to Embodiment 1 transitions from the EV mode to engine starting mode 2301 c to downshift mode 2302 c to the HEV mode in conjunction with an downshift request, as shown in FIG. 10 , when transitioning modes to the HEV mode due to an increase in the accelerator pedal opening while operating in the EV mode, after which it completes the lift-start of engine E while it is in the stopped state by means of the drag torque of the first clutch CL 1 , and begins the downshift of automatic transmission AT. Therefore, the rotational difference in first clutch CL 1 can be minimized at the time of the lift-start of engine E and the drive force can be raised by means of the downshift, as shown in the drive force characteristics at downshift mode 2302 c in FIG. 13 , while at the same time suppressing the deterioration of the durability of the clutch due to heat generation in the first clutch CL 1 . In addition, the higher the gear ratio is, the smaller the sensitivity is to the drive force fluctuation from the torque fluctuation due to the starting of the engine, so the shock experienced when starting the engine can be suppressed by starting the engine while this sensitivity is small.
[0072] When the engine starting control means for the engine starting control device pertaining to Embodiment 1 lift-starts engine E in the stopped state using the drag torque of the first clutch CL 1 , the drag torque of the first clutch CL 1 is compensated for by motor/generator MG. Therefore, the decrease in the drive force due to the drag torque of first clutch CL 1 is suppressed, and the continuity of the drive force is ensured as shown according to the drive force characteristics for engine starting mode 2302 a in FIG. 11 , the drive force characteristics for engine starting mode 2301 b in FIG. 12 and the drive force characteristics for engine starting mode 2301 c in FIG. 13 .
[0073] Next is provided an explanation of the effects. The effects listed below can be achieved for the engine starting control device for a hybrid vehicle pertaining to Embodiment 1.
[0074] (1) The aforementioned engine starting control means can suppress the deterioration of the durability of first clutch CL 1 , while at the same time ensuring a rotational state in which engine E can be started and thus improve fuel consumption when transitioning modes to the HEV mode while operating in the EV mode by controlling the gearshift ratio of automatic transmission AT so that the transmission input rotation speed becomes close to the engine rotation speed that is possible for engine operation in a range in which the transmission input rotation speed is the same or more than the rotation speed that is possible for engine operation when transitioning to the HEV mode while operating in the EV mode.
[0075] (2) The aforementioned engine starting control means can minimize the rotational difference of first clutch CL 1 during the time period until the lift-start of engine E is completed and suppress the deterioration of the durability of the clutch due to the generation of heat in first clutch CL 1 by completing the engagement of first clutch CL 1 after upshifting automatic transmission AT in conjunction with an upshift request when transitioning modes to the HEV mode while operating in the EV mode.
[0076] (3) The aforementioned engine starting control means can minimize the rotational difference of first clutch CL 1 from the time at which the lift-start of engine E is started and even further suppress the deterioration of the durability of the clutch due to the generation of heat in first clutch CL 1 by starting the engagement of first clutch CL 1 and lift-starting engine E in the stopped state using the drag torque of first clutch CL 1 after completing an upshift at automatic transmission AT in conjunction with an upshift request when transitioning modes to the HEV mode while operating in the EV mode.
[0077] (4) The aforementioned engine starting control means can suppress the decrease in the drive force due to an upshift and ensure the continuity of the drive force by raising the torque of the motor/generator MG in accordance with the decrease in the torque transfer ratio in automatic transmission AT that accompanies the upshift in the gearshift ratio of automatic transmission AT.
[0078] (5) The aforementioned engine starting control means can complete the mode transition from the EV mode to the HEV mode with a favorable responsiveness while at the same time suppressing the generation of heat in first clutch CL 1 with minimal rotational difference in first clutch CL 1 by immediately starting the engagement of first clutch CL 1 and lift-starting engine E in the stopped state using the drag torque of first clutch CL 1 when not accompanied by a gear change request when transitioning modes to the HEV mode while operating in the EV mode.
[0079] (6) The aforementioned engine starting control means can minimize the rotational difference in first clutch CL 1 when lift-starting engine E and raise the drive force by means of a downshift while at the same time suppressing the deterioration in the durability of the clutch due to the heat generated in first clutch CL 1 by starting the downshift of automatic transmission AT after completing the lift-start of engine E in a stopped state using the drag torque of first clutch CL 1 in conjunction with a downshift request when transitioning modes to the HEV mode while operating in the EV mode. In addition, the higher the gear ratio is, the smaller the sensitivity is to the drive force fluctuation from the torque fluctuation due to the starting of the engine, so the shock experienced when starting the engine can be suppressed by starting the engine while this sensitivity is small.
[0080] (7) The aforementioned engine starting control means can suppress the decrease in the drive force due to the drag torque of first clutch CL 1 and ensure the continuity of the drive force by compensating for the drag torque of first clutch CL 1 by means of motor/generator MG when lift-starting engine E in the stopped state using the drag torque of first clutch CL 1 .
Embodiment 2
[0081] Embodiment 2 is an example of when two different maps are used for the EV mode and the HEV mode as the shift maps for automatic transmission AT as compared to Embodiment 1 in which the same maps were used for the EV mode and the HEV mode as the shift maps for automatic transmission AT. With the exception of the target automatic transmission shift calculation for step S 403 performed by operating point command unit 400 shown in FIG. 6 , the steps for Embodiment 2 are the same as those for Embodiment 1, so an explanation and illustration has been omitted.
[0082] At step S 403 , when the target mode is the HEV mode, the target automatic transmission shift is calculated from the accelerator pedal opening APO and the vehicle speed VSP using the shift map shown in FIG. 7 . In addition, as shown in FIG. 14 , from the standpoint of the efficiency in the EV mode and the efficiency in the HEV mode, the upshift and downshift lines for when the target mode is in the EV mode are set more towards the high vehicle speed side than the upshift and downshift lines for the HEV mode. However, the target automatic transmission gear ratio is set so that the automatic transmission input rotation speed at the current vehicle speed is higher than the rotation speed that is possible for engine operation.
[0083] FIG. 14 shows an example of the upshift line from the 4 th speed to the 5 th speed and the downshift line from the 5 th speed to the 4 th speed. When operating at the 5 th speed in the EV mode and changing the accelerator pedal opening from point A to point A′, which cross over the downshift line, the engine is started in conjunction with the downshift. On the other hand, when operating at a lower vehicle speed than the downshift line in the EV mode, or at a higher vehicle speed than the upshift line in the HEV mode, such as point C, and the target mode becomes the HEV mode due to a decrease in the battery SOC when operating at the 4 th speed in the EV mode, the engine is started in conjunction with an upshift from the 4 th speed to the 5 th speed.
[0084] Next, is provided an explanation of the operation. For the engine starting control means for the engine starting control device pertaining to Embodiment 2, the upshift line and downshift line for when the target mode is the EV mode are set more toward the high vehicle speed side than the upshift line and downshift line for when the target mode is the HEV mode in relation to the shift map for the automatic transmission AT.
[0085] Therefore, the vehicle operating point does not change while operating in the EV mode, so when a mode transition request to transition to the HEV mode due to a decrease in the battery SOC is made, the engine can be started in conjunction with the upshift request, so the engine can be started in conjunction with an upshift request more frequently and more aggressively than was the case for Embodiment 1, the rotational difference in first clutch CL 1 that takes place when lift-starting engine E can be reduced, and the deterioration of the durability of the clutch can be effectively suppressed. The rest of the operation is the same as those described for Embodiment 1, so further explanation has been omitted.
[0086] Next is provided an explanation of the effects. In addition to the effects described in numbers (1) through (7) for Embodiment 1, the effect described below can also be achieved for the engine starting control device for a hybrid vehicle pertaining to Embodiment 2.
[0087] (8) For the aforementioned engine starting control means, since the upshift line and downshift line for when the target mode is the EV mode are set more toward the high vehicle speed side than the upshift line and downshift line for when the target mode is the HEV mode in relation to the shift map for the automatic transmission AT, the vehicle operating point does not change while operating in the EV mode, so when a mode transition request to transition to the HEV mode due to a decrease in the battery SOC is made, the engine can be started in conjunction with an upshift request more frequently and more aggressively than was the case for Embodiment 1, the rotational difference in first clutch CL 1 that takes place when lift-starting engine E can be reduced, and the deterioration of the durability of the clutch can be effectively suppressed.
[0088] Explanation has been provided for the engine starting control device for a hybrid vehicle based on Embodiments 1 and 2, but the specific constitution is not limited to these embodiments, and modifications and additions may be made to the design as long as they do not deviate from the gist of the invention pertaining the scope of claims for the present patent.
[0089] For Embodiment 1, an automatic transmission that changes the gearshift ratio in steps was used as an example for the transmission, but a continuously variable transmission in which the gearshift ratio is continuously changed may also be used. In such a case, the engine starting control means performs control to change the gearshift ratio to the upshift side or the downshift side, including making no change in the gearshift ratio, so that the transmission input rotation speed coincides with a target rotation speed that is the same or more than the rotation speed possible for engine operation when transitioning modes to the HEV mode while operating in the EV mode. So, in essence, if the engine starting control means controls the gearshift ratio of the transmission so that the transmission input rotation speed becomes closer to the rotation speed that is possible for engine operation within a range in which the transmission input rotation speed becomes the same or more than the rotation speed that is possible for engine operation in accordance with a system request that is made while operating in the EV mode and switching modes to the HEV mode, the means is not limited to Embodiment 1 or 2.
[0090] Embodiments 1 and 2 are examples of the application of the present invention to a rear-wheel drive hybrid vehicle, but it is also applicable to a front-wheel drive hybrid vehicle or a four-wheel drive hybrid vehicle. Embodiments 1 and 2 are also examples in which a clutch that was housed inside of the automatic transmission was used as the second clutch, but a second clutch may be added and disposed between the motor/generator and the transmission or added and disposed between the transmission and drive wheels (for example, Japanese Unexamined Patent Application Publication No. 2002-144921). So, in essence, the present invention can be applied to a hybrid vehicle that comprises a hybrid drive system in which a first clutch has an adjustable torque capacity is disposed between the engine and the motor/generator and a transmission that changes the gearshift ratio continuously or in steps is disposed between the motor/generator and the drive wheels. | An engine of a hybrid vehicle is lift started by reducing a rotational speed of a motor/generator of the hybrid vehicle by adjusting a gearshift ratio of a transmission coupled to the motor/generator, and engaging a clutch to couple the engine, while in a stopped state, to the rotating motor/generator for imparting the rotation to the engine. | 1 |
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