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FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to an ink jet recording apparatus, which records by jetting ink droplets onto recording medium. It also relates to a method for controlling the temperature of an ink jet recording head.
[0002] As an image forming apparatus which records on recording medium such as paper, OHP sheet, etc., various image forming apparatuses which employ one or more recording heads have been proposed. There are various recording methods for a recording head, for example, recording methods of the wire dot type, thermal type, thermal transfer type, ink jet type, etc. A recording apparatus which uses an ink jet recording method (which hereafter will be referred to as ink jet recording apparatus) directly jets ink from its recording head onto recording medium. Therefore, it is low in operational cost, and is superbly quiet during a recording operation.
[0003] An ink jet recording head has multiple nozzles through which ink droplets are jetted. It has been known that the performance of an ink jet recording apparatus is affected by ink temperature. That is, the properties, more specifically, diameter, which the ink in the recording head will have as it is jetting out in the form of an ink droplet, is affected by the ink temperature. Further, in the case of a recording apparatus which uses thermal energy to jet ink, it does not occur that all of energy given to ink works for jetting ink. In other words, a certain portion of the thermal energy given to the ink in an ink jet recording head to cause the ink to jet out of the recording head remains stored in a recording head, accumulating therein. Therefore, an ink jet recording head tends to increase in temperature if it is continuously used. This fact has also been known. As an ink jet recording head increases in temperature, it changes in the amount by which each of its nozzles jets ink per jetting, which will result in a change in the diameter of the dot each ink droplet will form as it lands on recording medium. The change in the diameter of each dot changes an image in density. Thus, it is possible that as an ink jet recording apparatus is continuously used, it changes in the density level at which it forms an image. Further, when the ink in an ink jet recording head is low in temperature, it is low in viscosity. Thus, when the temperature of an ink jet recording head is low, the ink therein is low in viscosity, and therefore, the ink is not going to be normally jetted at the beginning of a recording operation, sometimes causing the ink jet recording head to form an unsatisfactory image. Thus, in order to enable an ink jet recording apparatus to yield a satisfactory image from the very beginning of a recording operation, the ink jet recording apparatus is controlled in recording head temperature before the recording operation is started.
[0004] Registered Japanese Patent 2731274 discloses a technology for controlling the temperature of an ink jet recording head. According to this technology, after an ink jet recording apparatus is turned on, its ink jet recording head is heated to a preset temperature level, at which the temperature of the recording head is kept until recording signals begin to be inputted. Then, as soon as recording signals begin to be inputted, the recording head is heated in such a manner that the temperature of the recording head virtually instantly increases to the final level at which the recording head temperature should be, before the actual recording begins. This document discloses another technology for controlling the temperature of an ink jet recording head. This technology is for solving the problem that, because the increase in the recording head temperature caused by a heater of a large capacity is too rapid relative to the response time of a recording head temperature detecting device, the recording head becomes nonuniform in temperature. According to this technology, an ink jet recording apparatus is provided with two heaters for heating the recording head. One of the heaters is placed in the adjacencies of the openings of the ink nozzles, and the other is placed in the adjacencies of the temperature sensor. The two heaters are placed in the adjacencies of where the nozzles are open. Further, the two heaters are used, individually or in combination, according to the reason for heating the recording head.
[0005] If a heating element of the recording head of an ink jet recording apparatus is controlled to very quickly generate a large amount of heat to increase the temperature of the recording head to a preset level before the start of a recording operation, the portion of the recording head, which is immediately next to the heating element becomes different in temperature from the portion of the recording head, which is not next to the heating elements. This is a problem. That is, the portion of the recording head, which is not next to the heating element, sometimes fails to reach the temperature level at which proper recording is possible, by the time the portion of the recording head, which is next to the heating element reaches the temperature level at which proper recording is possible. If an image begins to be recorded while the recording head is in the above described condition, that is, before the entirety of the recording head is heated to the proper temperature level, it is possible that the recording head will fail to properly jet ink, and therefore, an unsatisfactory image will be yielded.
[0006] On the other hand, there was the problem that when an attempt was made to control the heating element so that it very quickly generates a large amount of heat to very quickly increase the temperature of the entirety of the recording head to the proper level for recording, the portion of the recording head, which is next to the heating element, became excessively high in temperature. If a recording operation is started while the ink jet recording head is in this condition, the recording head fails to be fully refilled for continuously jetting ink, because the amount by which ink is jetted by an ink jet recording head increases as the recording head temperature increases. Thus, as the recording operation continues, the amount by which ink is jetted per jetting by the recording head gradually reduces to an unsatisfactory level. If the heaters for jetting ink are also used as the means for heating the recording head immediately before the start of a recording operation, closer attention must be paid to this problem.
[0007] One of the methods for ensuring that both the temperature of the portion of the recording head, which is next to the heating element, and the temperature of the portion of the recording head, which is not next to the heating element, rise to a preset level virtually at the same time is to gradually heat a recording head by using less intensive pulse to drive the heating elements. This method, however, requires a long time to ensure that the temperatures of both the abovementioned portions of the recording head, which are next to, and not next to, the heating element, rise to the preset temperature level at the same time. Thus, this method is problematic in that it reduces an ink jet recording apparatus in throughput.
[0008] Another method for ensuring that the entirety of an ink jet recording head becomes uniform in temperature at a preset level before the start of a recording operation is to heat the recording head to the preset temperature level immediately after the recording apparatus is turned on, and then, keep the temperature of the recording head at this level until recording signals begin to be inputted. This method, however, is problematic in that it increases the amount of electric power consumed while the recording apparatus is kept on standby until recording signals begin to be inputted.
SUMMARY OF THE INVENTION
[0009] The present invention was made to solve the above described problems, which the methods, in accordance with the prior art, for controlling the recording head temperature before the start of a recording operation have, and its primary object is to provide an ink jet recording apparatus which forms high quality images from the very beginning of a recording operation while being just as high in throughput as an ink jet recording apparatus in accordance with the prior art, and the method for forming high quality images from the very beginning of a recording operation without reducing an ink jet recording apparatus in throughput.
[0010] According to an aspect of the present invention, there is provided an ink jet recording apparatus for effecting recording using a recording head for ejecting ink, said ink jet recording apparatus comprising heating means for heating said recording head; detecting means for detecting a temperature of said recording head; setting means for setting a target temperature of said recording head, control means for controlling the target temperature of said recording head at or above a target temperature; wherein said control means controls the temperature by heating control for heating said recording head and by diffusing control for diffusing the heat supplied by the heating control.
[0011] According to another aspect of the present invention, there is provided an ink jet recording apparatus for effecting recording using a recording head for ejecting ink, said ink jet recording apparatus comprising heating means for heating said recording head; detecting means for detecting a temperature of said recording head; and control means for effecting different temperature controls to provide a predetermined temperature of said recording head prior to start of the recording operation.
[0012] According to a further aspect of the present invention, there is provided a temperature control method for a recording head for effecting recording by ejecting ink, comprising a heating step of heating said recording head; a detection step of detecting a temperature of said recording head; a setting step of setting a target temperature of said recording head; and a control step of controlling a temperature of said recording head at or above a target temperature, wherein said control step controls the temperature by heating control for heating said recording head and by diffusing control for diffusing the heat supplied by the heating control.
[0013] According to a further aspect of the present invention, there is provided a temperature control method for a recording head for effecting recording by ejecting ink, comprising a heating step of heating said recording head; a detection step of detecting a temperature of said recording head; control means for effecting different temperature controls to provide a predetermined temperature of said recording head prior to start of the recording operation; and control means for effecting different temperature controls to provide a predetermined temperature of said recording head prior to start of the recording operation.
[0014] The present invention, which is related to the temperature control of a recording head, makes it possible to quickly increase the recording head temperature to a desired level without creating the problems attributable to the overheating of the recording head. Thus, it makes it possible to provide a recording apparatus which forms images of excellent quality from the very beginning of a recording operation, regardless of ambient conditions, without declining in productivity.
[0015] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a perspective view of the ink jet recording apparatus in the first embodiment of the present invention.
[0017] FIG. 2 is a block diagram of the control system of the ink jet recording apparatus in the first embodiment.
[0018] FIG. 3 is a schematic drawing of the recording head in the first embodiment of the present invention.
[0019] FIG. 4 is a flowchart of the recording heat temperature control sequence to be carried out before the start of a recording operation, in the first embodiment.
[0020] FIG. 5 is a flowchart of the first temperature control stage in the recording head temperature control sequence in the first embodiment of the present invention.
[0021] FIG. 6 is a flowchart of the second temperature control stage in the recording head temperature control sequence in the first embodiment of the present invention.
[0022] FIGS. 7( a ) and 7 ( b ) are tables for setting the target value for the recording head temperature, and the target value for the length of time the recording head temperature is maintained at a preset level, respectively.
[0023] FIG. 8 is a graph showing the relationship between the temperature of an ink jet recording head and the ink jetting performance of the ink jet recording head.
[0024] FIG. 9 is a flowchart of the first temperature control stage in the second embodiment of the present invention.
[0025] FIG. 10 is a flowchart of the second temperature control stage in the second embodiment of the present invention.
[0026] FIG. 11 is a table for setting the target values for the recording head temperature, in the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the appended drawings.
<General Description of Recording Apparatus>
[0028] First, a typical ink jet recording apparatus to which the present invention is applicable will be described regarding its general structure and operation.
[0029] FIG. 1 is a schematic drawing of the entirety of the typical ink jet recording apparatus to which the present invention is applicable.
[0030] Referring to FIG. 1 , the ink jet recording apparatus is structured so that a recording medium 102 is pinched by the paper conveyance roller 101 , and the pair of rollers which oppose the paper conveyance roller 101 . As the paper conveyance roller 101 is rotated, the recording medium 101 is conveyed in the secondary scan direction, or the direction indicated by an arrow mark Y in the drawing. The recording head 105 is removably attached to the carriage 104 . It is provided with multiples nozzles from which ink droplets are jetted; the opening of each nozzle is at the surface of the recording head 105 , which faces the platen. The carriage 104 is reciprocally movable in the primary scan direction, or the direction indicated by an arrow mark X, by an unshown carriage driving means, while being guided by the primary carriage guides 103 . As the recording head 105 on the carriage 104 jets ink droplets while the carriage 104 is moved relative to the recording medium 102 in a manner to scan (which hereafter will be referred to as primary scan) the recording medium 102 , an image is effected on the recording medium 102 . The recording head 105 is connected to an ink container in which ink is stored, or an ink supplying apparatus, so that the recording head 105 is supplied with the ink from the ink container or ink supplying apparatus. The platen 106 is located below the recording head 105 . It is long enough to reach one end of the recording range of the recording head 105 to the other. The distance between the recording head 105 and platen 106 is such that when the recording medium 102 is on the platen 106 , the gap between the recording medium 102 and recording head 105 is proper for recording.
[0031] Although not shown in FIG. 1 , this ink jet recording apparatus is provided with a recording medium feeding means, which feeds the recording medium 102 into the recording apparatus so that the recording medium 102 can be conveyed further by the paper conveyance roller 101 . It is also provided with: a recovery means for keeping the recording head 105 in the proper condition for jetting ink, and/or restoring the recording head 105 in ink jetting performance; and a recording medium discharging means for discharging the recording medium 102 out of the ink jet recording apparatus after the completion of the recording of an image on the recording medium 102 by the recording head 105 . There are various recovering means: a capping means which covers the surface of the recording head 105 , which has the nozzle openings, a cleaning means which wipes clean the surface of the recording head 105 , which has the nozzle openings, a suctioning or pressurizing means which removes the ink in the recording head 105 , a preparatory ink jetting means which causes the recording head to jet ink droplets which do not contribute to the actual recording of an image (recording operation based on image data). These recovering means are effective for keeping the ink jetting performance of the ink jet recording head (apparatus) stable at a satisfactory level.
[0032] The recording operation of the ink jet recording apparatus shown in FIG. 1 is as follows:
[0033] As the ink jet recording apparatus 105 receives a recording start command (signal) from an external apparatus (host computer or the like) connected to the ink jet recording apparatus 105 , one of the recording mediums 102 is conveyed from the upstream side of the recording apparatus, in terms of the secondary scan direction, by the recording medium feeding-and-conveying means, until the leading edge of the recording medium 102 reaches the location of the paper conveyance roller 101 . Then, the recording medium 102 is conveyed further by the paper conveyance roller 101 , in response to a recording signal, so that the recording start point on the recording medium 101 lines up with the recording head 105 . Then, the recording head jets ink while the carriage on which the recording head is borne is moved in the primary scan direction. As a result, a part of the intended image is effected on the recording medium 102 . Then, the recording medium 102 is conveyed forward by a preset distance by the paper conveyance roller 101 (hereafter, this conveyance of recording medium by paper conveyance roller will be referred to as recording medium conveyance operation). Then, the recording head 105 jets ink while the carriage on which the recording head 105 is borne is moved in the primary scan direction. This operation for causing the recording head to jet ink while it is moved in the primary scan direction by the carriage, and the abovementioned recording medium conveyance operation, are alternately repeated until the entirety of the intended image is effected on the recording medium 102 . Thereafter, the recording medium 102 is discharged from the downstream side of the ink jet recording apparatus, in terms of the secondary scan direction. Ordinarily, paper is used as the recording medium. However, recording media other than paper may be used as the recording medium 102 . For example, an OHP sheet, a compact disc, etc., may be used. Moreover, in the case of a DNA chip manufacturing apparatus or a display manufacturing apparatus, which employs an ink jet head, any substance may be used as the recording medium 102 as long as the substance is suitable as the material for the substrate.
[0034] FIG. 2 is a block diagram of the control system of the recording apparatus.
[0035] As will be evident from FIG. 2 , the control system 57 has an internal interface 30 , which interfaces between a printer (recording apparatus 105 ) and a host computer. The interface 30 is provided with a signal path through which it receives recording data and commands from the host computer. The ROM 33 stores the control programs which are carried out by the CPU 35 . The DRAM 31 stores various data while the CPU 35 carries out the programs in the ROM 33 . It also stores the recording data to be supplied to the recording head 105 . The gate array 36 controls the recording data which are sent from the RAM 31 to the recording head 105 . It also controls the data transfer among the interface 30 , CPU 35 , and RAM 31 .
[0036] The carriage motor driver 25 drives the carriage motor 27 in order to move the recording head 105 to the preset recording point in the recording range in terms of the primary scan direction in response to the signals which are outputted from the control system 57 (or CPU 35 ). Similarly, the recording head driver 24 drives and controls the recording head 105 , and the paper conveyance motor driver 28 drives and controls the paper conveyance motor 29 , in order to record an image on the recording medium 102 and conveys the recording medium 102 .
[0037] Further, the gate array 36 and CPU 35 of this control system 57 receive the recording signals, such as picture data and control commands, from the host computer through the interface 30 , and convert the received recording signals into recording data. Then, they store the recording data in the RAM 31 . Further, the control system 57 synchronously drives the motor drivers 24 , 25 , and 28 to make the recording head 105 carry out a recording operation, to make the paper conveyance roller convey the recording medium 102 , and also, to make the carriage (recording head 105 ) reciprocally move in the primary scan direction so that an image is effected on the recording medium 102 .
[0038] The ink jet recording apparatus in this embodiment of the present invention jets ink by generating thermal energy for boiling the ink, by driving the electrothermal transducing element in each of the multiple nozzles of the recording head 105 in response to the electrical signals which are sent from the head driver 24 . The amount by which ink is jetted per jetting from each of the nozzles of the recording head 105 is affected by the temperature of the recording head 105 . Therefore, it is very important to know the temperature of the recording head 105 . Thus, the recording apparatus is provided with a thermistor 40 for measuring the ambient temperature of the recording apparatus (which may be called environmental temperature), and a head diode 58 for measuring the recording head temperature. Both are calibrated at the beginning. Incidentally, the recording apparatus may be provided with a sensor capable of measuring the humidity as well as temperature, instead of the thermistor 40 which measures only the environmental temperature. It may be outside the recording apparatus, or relatively close to the recording head, for example, on the carriage, where the thermistor 40 is positioned. Moreover, the recording apparatus may be set up so that the environmental temperature is estimated based on the temperature detected by the head diode located near the nozzle openings of the recording head.
[0039] FIG. 3 is a schematic drawing of the recording head 105 .
[0040] FIG. 3 is a drawing for conceptually describing the heater board 70 of the recording head 105 , which is on the silicon wafer, and ink jetting nozzles which are on the heater board 70 . The heater board 70 is shared by the multiple rows of ink nozzles (or nozzle groups) of the recording head 105 , which are different in the color of the ink they jet. Thus, for the sake of simplification, only a single row of ink nozzles is shown.
[0041] There are multiple heating elements on the heat board 70 . The heating elements are arranged so that they are in the ink nozzles (which may be referred to simply as nozzles), one for one.
[0042] Incidentally, in FIG. 3 , the entirety of the multiple heating elements (heaters) which are in the nozzles, one for one, is designated with a referential number 74 . In order to make it easier to conceptually understand the ink jet recording system, FIG. 3 shows a smaller number of ink nozzles, which are represented by small circles, than the actual number. That is, some ink jet recording heads have as many as 1,280 nozzles per color (per row). Designated by a referential number 79 is a common ink chamber through which ink is supplied to each nozzle. The common ink chamber 79 also serves as an ink storage chamber in which the ink to be supplied to each of the nozzles is stored.
[0043] In this embodiment, the recording head 105 is provided with a pair of head diodes 58 for measuring the temperature of the recording head. The head diodes 58 are located near the ends of the recording head 105 , in terms of the direction in which the openings of the nozzles of each nozzle row are aligned. The recording head 105 is heated by driving the heating elements in the nozzles in such a manner that the amount of heat generated by the heating elements is not enough to cause ink to be jetted, but, is enough to heat the recording head.
[0044] The primary characteristic of the present invention is that the present invention makes it possible to heat a recording head before the starting of a recording operation, in such a manner that the ink in the adjacencies of the heating elements, the ink in the common ink chamber, and the ink in the ink passages, increase in temperature to a proper level for a recording operation, without making the recording head temperature excessively high.
<Temperature Control of Recording Head>
[0045] FIG. 4 is a flowchart of the pre-operational recording head temperature control sequence, which characterizes the present invention.
[0046] As a recording signal is detected in Step S 200 , the ambient humidity (environmental humidity) of the recording apparatus is obtained in the following step (S 201 ). Then, the conditions which need to be set for the first and second temperature control stages are obtained in Step S 2002 . These conditions for the first and second temperature control stages are: the target temperature level for each of the two operations; pulse specification for each of the two operations; and the length of the second temperature controlling operation. In the next step (S 203 ), the counter for measuring the length of time the recording head temperature is maintained at a preset level, is reset. Then, the steps (Step 204 and Step 205 ) in the pre-operational recording head temperature control sequence, which characterize the present invention, are carried out in succession. Thereafter, a recording operation is started in Step S 206 .
[0047] Incidentally, adding a pre-jetting step, that is, a step in which ink is jetted for a preparatory purpose, between the second temperature controlling sequence (Step S 204 ) and the starting of a recording operation is useful to ensure that ink is satisfactorily jetted from the very beginning of a recording operation, although this pre-jetting step is not shown in FIG. 4 .
[0048] Hereafter, the present invention, which relates to the first and second temperature control stages in the pre-operational recording head temperature control sequence, will be described in detail with reference to the preferred embodiments of the present invention. The various values set in the following preferred embodiments of the present invention are simply examples, and are not intended to limit the present invention in scope.
Embodiment 1
[0049] In this embodiment, the first temperature control stage is the stage for continuously heating the recording head until the recording head temperature reaches the target level, that is, the temperature level to which the recording head temperature needs to reach before the start of a recording operation. The second temperature control stage is the stage for allowing the heat provided in the first temperature control stage to spread to make uniform in temperature the entirety of the recording head, including the portion of the recording head in the adjacencies of the heating elements. If necessary, the heating elements are driven to maintain the temperature of the recording head at the target level, even in the second temperature control stage which comes after the temperature of the portion of the recording head in the adjacencies of the heating elements reaches the target temperature. FIGS. 5 and 6 are flowcharts of the first and second temperature control stages in this embodiment of the present invention.
[0050] Referring to FIG. 5 , first, various conditions necessary for the first temperature control stage are set in Step S 300 , according to the environmental information, more specifically, ambient temperature and humidity, obtained in Step S 201 in FIG. 4 . More specifically, the proper value for the target temperature level for the second temperature control stage is obtained based on Table A in FIG. 7 , which shows the relationship among the environmental temperature and humidity, and the target temperature, and the obtained environmental temperature and humidity information. Then, the target temperature level for the second temperature control stage is set to this value. This table which shows the relationship among the temperature, humidity, and target temperature is stored in the ROM (memory) 33 . The temperature level selected in this step is the temperature level at which the temperature of the recording head needs to be before the starting of a recording operation. Next, the values for the parameters of the pulse which is to be applied to drive the heating element to heat the recording head to the target temperature level are set. Then, in Step S 301 , the heating elements of the recording head are driven, using the pulses specified in the preceding step, so that the temperature of the recording head increases to the target temperature level. In Step S 302 , the temperature of the recording head is detected by the head diode, and then, it is determined whether or not the temperature of the recording head has reached the target level. If it is determined that the temperature of the recording head has not reached the target level, the control stage returns to Step S 301 , in which the heating elements are continuously driven. On the other hand, if it is determined in Step S 302 that the temperature of the recording head has reached the target level, the driving of the heating elements is stopped in the following step, or Step S 303 , ending thereby the first temperature control stage. As soon as the first temperature control stage ends, the second temperature control stage is started.
[0051] The first temperature control stage simply increases the temperature of the portion of the recording head in the adjacencies of the heating elements, to the target level. Thus, after the heating of the recording head through the first temperature control stage, the temperature of the ink in the ink chamber located a small distance away from the heating elements is lower than the target level. In other words, the recording head is nonuniform in temperature. If a recording operation is started when the recording head is in this condition, the recording head fails to continuously jet ink in a proper manner; the recording head fails to satisfactorily perform. In order to enable the recording head to satisfactory perform even when the recording head is nonuniform in temperature, it is necessary to continuously heat the recording head as it is in an ink jet recording apparatus in accordance with the prior art. In order to continuously heat the recording head even after the temperature of the portion of the recording head in the adjacencies of the heating elements, the target temperature level must be set to a value higher than the proper value. If the target temperature level is set to a value higher than the proper value, it is possible that the portion of the recording head in the adjacencies of the heating element will be overheated, and therefore, the recording head will fail to satisfactorily jet ink.
[0052] In this embodiment, therefore, in order to enable the recording head to satisfactorily jet ink from the beginning of a recording operation without increasing the temperature of the recording head to a level higher than a proper level, the recording head is made uniform in internal temperature by the second temperature control stage which is carried out immediately after the end of the first temperature control stage.
[0053] Referring to FIG. 6 , first, various conditions necessary for the second temperature control stage are set in Step S 400 , according to the environmental temperature and humidity information obtained in Step S 201 in FIG. 4 . More specifically, the value for the target temperature level, value for the length of time the recording head temperature is to be maintained at a preset level, and values for the parameters of the heating element driving pulse, for the second temperature control stage, are selected, based on the environmental temperature and humidity information obtained in Step S 201 , and Table B in FIG. 7 , which shows the relationship among the environmental temperature and humidity, and the length of time the recording head temperature is to be maintained at a preset level. Then, the target temperature level, the length of time the recording head temperature is to be maintained at the preset level (which hereafter will be referred to length of temperature maintenance), and the parameters of the heating element driving pulse are set to the selected values. This table which shows the relationship among the temperature, humidity, and the length of time the recording head temperature is to be maintained at the preset level, is stored in the ROM 33 . FIG. 7( b ) does not include the information regarding the target temperature. In this embodiment, therefore, the target temperature for the second temperature control stage is set to the same value as that for the first temperature control stage. However, the recording apparatus may be configured so that the first and second temperature control stages are different in target temperature level.
[0054] Next, the counter for measuring the length of temperature maintenance is turned on, and the routine for keeping constant the temperature of the recording head is started (Steps S 401 and S 402 ). Step S 402 in this temperature maintaining routine is such a step that if the recording head temperature, which is continuously obtained, is higher than the target temperature level, the heating of the recording head is stopped, and if the recording head temperature is lower than the target level, the driving of the heating elements is continued or restarted as long as the second temperature control stage is continued. If it is determined in Step S 400 , in which the recording head temperature detected by the head diode 58 is compared to the target temperature level, that the detected recording head temperature is lower than the target level, the heating elements are driven by the abovementioned temperature maintaining routine. If it is determined in Step S 403 that the detected temperature is higher than the target level, the counter for recording the duration of the temperature maintaining routine is increased in value (counted up) in the following step, or Step S 404 . Then, in Step S 405 , it is determined whether or not the length of the duration of the temperature maintaining routine, which is shown in the counter, is greater than a preset value. When the value (temperature maintaining routine duration count) in the counter is no greater than the preset value, the second temperature control stage reverts to Step S 403 . If it is determined that the value in the counter is no less than the preset value, the second temperature control stage is ended, and the recording operation shown in FIG. 4 is started (Step S 406 ). In this embodiment, the recording head is set up so that instead of measuring the length of time the temperature maintaining routine is continued since the beginning of the second temperature control stage, the number of times it is determined that the recording head temperature is higher than the target level is counted. With the employment of this setup, it is possible to maintain the recording head temperature at the preset level for a proper length of time regardless of the ambience of the recording apparatus. Although, in this embodiment, the number of times the recording head temperature is found to be higher than the target level is counted, the length of time the recording head temperature is found to be higher than the target level, that is, the length (preset length) of time the recording head temperature is kept at the temperature level at which the recording head can properly jet ink, can be obtained because the steps S 404 -S 405 are carried out with preset intervals.
[0055] FIG. 7 shows the examples of the values to which the various parameters are set in the steps in the flowcharts in FIGS. 5 and 6 . FIG. 7( a ) is a table to be used for setting the target temperature value according to the environmental conditions, and FIG. 7( b ) is a table to be used for setting the target value for the length of time the temperature maintaining routine is to be continued, according to the environmental conditions.
[0056] Referring to FIG. 7 , the values for the target temperature level are set according to the various combinations between the environmental temperature ranges (−18° C./19-28° C./29° C.-) and humidity ranges (−35%/36-65%/66%-). The values provided in FIG. 7( b ) for the length of the temperature maintaining routine do not represent the actual length of time, but, the number of times the recording head temperature is found to be higher than the target level, concurring with the second temperature control stage shown in FIG. 6 . The interval with which the recording head temperature is read during this temperature control stage is set to 30 ms. Thus, when the environmental condition is in Combination A, for example, the duration of the temperature maintaining routine is slightly longer than 3 seconds.
[0057] FIG. 8 shows the relationship between the recording head temperature and the ink jetting performance of the recording head. This relationship is used to create the tables in FIG. 7 .
[0058] Referring to FIG. 8 , the horizontal axis represents the recording head temperature, and the vertical axis represents the ink jetting performance of the recording head at the beginning of a recording operation. The bold black line represents an ink jetting performance level of 1.4, which is the borderline level. That is, if the ink jetting performance of the recording head is no higher than 1.4, it is determined that the recording head is unsatisfactory in ink jetting performance. The ink jetting performance level is calculated based on the length of time it took for the ink jetting performance of the recording head to decline to a level at which the recording head fails to satisfactorily jet the first ink dot droplet after the completion of the pre-recording operation recording head controlling sequence. The graph shows that the greater the numerical value, the better the ink jetting performance of the recording head at the beginning of a recording operation. The ink jetting performance of the recording head is affected by the ambience of the recording head. Thus, FIG. 8 shows the relationships between the ink jetting performance of the recording head and recording head temperature when the environmental condition of the recording head is Combination A (−18° C./−35% in environmental temperature and humidity), and when it is Combination E (19-28° C./36-65% in environmental temperature and humidity). From FIG. 8 , in Condition A, as the recording head temperature is no less than roughly 55° C., the ink jetting performance of the recording head is greater than 1.4, above which the performance is normal. Therefore, when the environmental condition is Combination A, the target temperature level should be set to 55° C. Similarly, when the environmental condition is Combination E, the target temperature level, that is, the temperature level above which the recording head is normal in ink jetting performance, is to be set to 45° C.
[0059] However, in the situation in which control must be executed to increase the recording head temperature, there is an undesirable possibility that a problem will occur because the temperature of the recording head becomes excessively high. The studies made by the inventors of the present invention revealed that in the case of a recording head, such as the recording head, the characteristics of which are shown in FIG. 8 , if the recording head temperature is higher than 50° C., it tends to form abnormal images at the beginning of a recording operation, which had been known from another study. On the other hand, the studies revealed that even if the target temperature level is the same, that is, 50° C., the provision of the temperature maintaining routine, can improve the ink jetting performance of the recording head, as indicated by an arrow mark in the drawing, without raising the recording head temperature to 55° C. In other words, the problem that an ink jet recording apparatus yields unsatisfactory images because of the excessive increase in the recording head temperature can be prevented by combining the heating operation for increasing the recording head temperature to a target temperature, with the heating operation for maintaining the recording head temperature at the target temperature, instead of abruptly increasing the recording head temperature immediately before the start of a recording operation. The heat given to the recording head before the start of a recording operation is diffused during the temperature maintaining period provided during the control stage referred to as temperature maintenance routine in the present invention. Therefore, the recording head becomes uniform in internal temperature at the target level for the satisfactory jetting of ink, making it unnecessary for the recording head to be heated to a temperature level higher than the target level.
[0060] Incidentally, the above described pre-recording operation temperature control sequence is to be carried out for all the recording heads employed by the recording apparatus. However, it was described with reference to only one of the recording heads. That is, in the case of a printer having multiple ink jet recording heads, the above described pre-recording operation head temperature control sequence is carried out for the multiple recording heads at the same time. However, the multiple recording heads will be different in the point of time at which the sequence ends. For the purpose of ensuring that the printer performs at its highest level, it is desired that a recording operation is started after the pre-recording operation head temperature control sequence is completed for all the recording heads. That is, even if the temperature of a given recording head reaches the target level through the first and second temperature control stages, the temperature of this recording head must be maintained at the target level. Therefore, while this recording head is kept on standby, the temperature maintaining routine is desired to be continued for this recording head even after the second temperature control stage for this recording head is completed. Thus, in the case of an ink jet recording apparatus having multiple recording heads, a step in which it is determined whether or not the temperature maintenance counts of all the recording heads have exceeded the target value, must be added as the next step to Step S 404 in FIG. 4 , before the completion of the second temperature control stage.
[0061] The relationship shown in FIG. 8 is affected by what kind of ink is used for a recording operation. Therefore, it is desired that the values for the parameters for the first and second temperature control stages are set according to the characteristics of the ink used for the recording operation. The first and second temperature control stages may be the same or different, in the values of the parameters (voltage, width, frequency, etc.) of the pulse used for driving the heating elements. However, from the standpoint of productivity (shorter in duration of temperature control routine), and/or the prevention of the problem attributable to the excessive heating of a recording head, it is desired that the first and second temperature control stages are different in the values of the parameters of the heating element driving pulse; the values for the parameters are to be switched during the transition from the first temperature control stage to the second so that for the first temperature controlling stage, the parameters are set to more aggressively heat the recording head than in the second temperature control stage, to make the temperature of the recording head quickly rise, whereas for the second temperature control stage the parameters are set to moderately heat the recording head to keep the temperature of the recording head stable at the target level.
[0062] Further, it is desired that the values for the parameters (target temperature, temperature maintenance routine duration and/or heating element driving pulse specification) for the first and second temperature control stages are set according to the length of the time having elapsed since the last printing operation. That is, it is reasonable to think that when two recording operations are continuously carried out, the entirety of the recording head is uniform in temperature at a level close to the target temperature level because of the preceding recording operation. In such a case, it is desired that the parameters are set according to the condition of the recording head immediately before the starting of the second recording operation; for example, the recording head temperature maintaining routine is reduced in duration.
[0063] Incidentally, in this embodiment, the heating elements used for the first and second recording head temperature control stages are the same as those used for jetting ink. However, the recording head may be provided with heating element dedicated to the heating of the recording head. In the case that the recording head is provided with the heating elements (sub-heaters) dedicated to the heating of the head in addition to the heating elements (primary heaters) for jetting ink, an operational arrangement may be made so that for the purpose of heating the recording head, both the primary and subordinate heaters are used, whereas for the purpose of jetting ink, only the primary heaters are used. Further, the first and second head temperature control stages may be different in the heaters used therefore.
Embodiment 2
[0064] In the first embodiment, in order to achieve two objects of preventing the problem that unsatisfactory images are yielded because of the overheating of the recording head attributable to aggressive heating of the recording head, and preventing the problem that carrying out the first and second head temperature control stages reduces an ink jet recording apparatus in productivity, the first and second head temperature control stages are not differentiated in target temperature level, and the head temperature maintaining routine was provided. In the second embodiment, however, instead of providing the head temperature maintaining routine, the first and second heat temperature control stages are made different in target temperature level, so that the final target temperature level is reached in two stages. More specifically, in the first temperature control stage, the recording head is heated so that its temperature quickly reaches a target temperature level (first temperature level), which is different from the final target level (second temperature level), and in the second temperature control stage, which immediately follows the first temperature control stage, the recording head is gradually heated from the first temperature level to the second temperature level to prevent the recording head from being overheated. FIGS. 9 and 10 are flowcharts of the first and second recording head temperature control stages in the second embodiment, and are for describing the second embodiment.
[0065] The first temperature control stage shown in FIG. 9 is not different from the first temperature control stage in the first embodiment, except for the value set for the target temperature level (first temperature level). That is, in the first temperature control stage in this embodiment, in order to increase the recording head temperature in a short time, the parameters of the heating element heating pulse are set in a manner to intensify the pulse, or the target temperature level (first target temperature level) is set to a value higher than the ideal final target level obtainable from FIG. 8 so that the parameters of the heating element driving pulse are set to make the pulse slightly stronger than the pulse used in the first temperature control stage in the first embodiment. The target temperature level (first level) for the first temperature control stage in this embodiment, which is to be set in Step S 701 , is desired to be as close as possible to the final target value, within a range in which no problem occurs at the beginning of a recording operation.
[0066] In the second temperature control stage shown in FIG. 10 , the value for the final target temperature level is set, and the parameters of the heating element driving pulse are reset so that the recording heat temperature is more gradually increased until the final target temperature level is reached.
Embodiment 3
[0067] In the first embodiment, the target temperature level and duration of temperature maintenance routine are set according to the condition of the ambience of the recording apparatus. However, the recording head temperature fluctuates due to the changes in printing conditions, such as print width, print duty, etc., during a recording operation. Therefore, it is desired that the parameters such as the target temperature level and duration of temperature maintenance routine are reset in response to the changes in the printing conditions such as print width, print duty, etc. In this embodiment, the adjustment is made in response to the changes in print width and print duty. However, for the simplification of description of this embodiment, only the adjustment to be made to the target temperature level will be described.
[0068] FIG. 11 is a table which shows the relationship among the basis target temperature levels which correspond to the environmental temperature and humidity levels, and the amounts by which the basis target temperature levels are to be adjusted according to the paper width. The value for each final target temperature level is the total of the basis target temperature value and the adjustment amount. In FIG. 11 , four values are provided for the amount by which the target temperature level is preset according to the combination of environmental temperature and humidity ranges is to be adjusted according to recording paper width. When a narrow recording medium (recording paper) is used for a recording operation, the length of time it takes to scan (recording scan) is short. Therefore, the conditions are relaxed for the temperature maintenance routine carried out immediately before the start of a recording operation to ensure that the recording head satisfactorily jets ink per scan. In comparison, in the case of the table in FIG. 7( a ), which is used in the first embodiment, the target temperature level is set to a value obtainable by adding the adjustment amount, in FIG. 11 , for a recording medium (paper) which is no less than 700 mm in width, to the basis target temperature value in FIG. 11 , in order to ensure satisfactory ink jetting performance regardless of recording medium (paper) width.
[0069] Incidentally, the target temperature values in FIG. 11 are such values that were not calculated in consideration of the estimated print duty in the following scan. In reality, if the section of an image, which is to be printed during the following scan, is high in print duty, not only does the head temperature quickly increase, but also, ink is jetted from the nozzles as the head temperature quickly increases. Therefore, the conditions for temperature maintaining routine can be relaxed. Given below is an example of the mathematical equation for obtaining the amount by which the target temperature level is to be adjusted. The choices of the adjustment method do not need to be limited to the one based on this equation. For example, an adjustment amount table may be provided for each print duty or an equation different from the following one may be used:
[0000] T=Ta−Tb× print duty (%),
[0070] wherein, “Ta” stands for the basic adjustment amount for each of different types of recording media (paper), which is adjusted by the “Tb× print duty (%)” to compensate for the difference in print duty. “Tb” stands for the coefficient of temperature requirement relaxation relative to print duty. It may be calculated from the data regarding the relationship between the increase in the recording head temperature and print duty, or may be deduced from the results of the evaluation of the ink jetting performance of the recording head made at the beginnings of a number of recording operations different in print duty. “T” stands for the final amount by which the target temperature level is adjusted for the recording medium (paper) to be used for the following recording operation. In other words, the final target temperature level is set to the value obtained by adding “T” to the basic target temperature value.
[0071] As described above, in this embodiment, the recording head temperature is controlled in consideration of the width of the recording medium, and/or print duty. Therefore, the temperature of the recording head remains at a more proper level, enabling thereby the recording head (image forming apparatus) to form an image of higher quality than in the preceding embodiments. Further, recording media different in type are different in ink absorbency. Therefore, some ink jet recording apparatuses are enabled to adjust themselves in the amount by which they make each of their nozzles to jet ink per jetting.
[0072] In the case of these ink jet recording apparatuses, the manner in which the recording head temperature increases is affected by what type of recording medium is used, and therefore, the type of the recording medium may be taken into consideration as one of the printing conditions when setting a value for the target temperature.
[0073] In the above, the first to third preferred embodiments of the present invention were described. However, these embodiments are not intended to limit the present invention in scope. Further, these embodiments may be implemented in combination.
[0074] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
[0075] This application claims priority from Japanese Patent Applications Nos. 098006/2006 and 055761/2007 filed Mar. 31, 2006 and Mar. 6, 2007, respectively, which are hereby incorporated by reference. | An ink jet recording apparatus for effecting recording using a recording head for ejecting ink, the ink jet recording apparatus including a heating section for heating the recording head, a detecting unit for detecting a temperature of the recording head, a setting unit for setting a target temperature of the recording head, and a controller for controlling the target temperature of the recording head at or above the target temperature. The controller controls the temperature by heating control for heating the recording head and by diffusing control for diffusing the heat supplied by the heating control. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a facsimile apparatus having an image memory capable of storing image information of a document.
Among various facsimile apparatuses, there is known a facsimile having an image memory capable of storing image information of a document.
For the aforesaid facsimile, the following examples of image memory applications are considered.
In one example, when a time-designated transmission mode or a same-information transmission mode is selected, image information of a document is read and then stored in the image memory before the start of transmission of the document for both cases. Then, after the completion of storage of the image information of the last document, an operator starts transmitting the stored image information.
In another example, a specific key is determined to be a key for memory-in use (a memory key) and image information of a document is stored in the aforesaid image memory when operating the memory key. Also in this case, the stored image information is transmitted through an operation by an operator.
When document-reading is started, without operating the memory-in key, the mode becomes an ordinary transmission mode. Therefore, when the circuit of a partner is not connected, connection to the circuit of the partner is a predetermined number of times. If the two apparatus still can not be connected, the document is ejected.
When the circuit of a partner is not connected during a transmission procedure in which a memory key is not used as stated above, the document is ejected after a certain period of time. Therefore, the operator is required to set up the same transmission procedure again after a certain period of time. Thus the transmission procedure is troublesome.
Further, when the image information of a document is stored in the image memory by the use of a memory key, there is no way for an operator to confirm that the documents' information has been transmitted without fail. This is because completion stamping, which is used for the purpose of confirming that the documents' information has been transmitted to the partner without fail after an ordinary transmission, is not carried out.
Further, when a same-information transmission mode is selected, completion-stamping is not carried out because processing is made without checking whether the partner is in use.
During the call for the circuit in the transmission when a memory key is not used, the document is not ejected. Therefore, it is not possible to transmit another document for the period until the suspension of the calling action by the completion of re-dialing action. Therefore, the utilization efficiency (the rate of operation) of the apparatus is very low.
The invention, therefore, offers a facsimile apparatus wherein the aforesaid problems have been solved by a simple structure, a simplification of the transmission procedure, and an improvement in the utilization efficiency.
SUMMARY OF THE INVENTION
In order to solve the aforesaid problems, the facsimile apparatus of the invention is characterized as an image memory capable of storing the image information of a document, the image information of the document is stored in the image memory when the apparatus is not connected to the circuit of a partner, and the image information stored in the image memory is transmitted automatically when the apparatus is connected to the partner circuit.
When connection cannot be made with the circuit of a partner, the image information of a document is stored in the image memory. Therefore, when a document is fed into the main body of the apparatus, optical reading of the document is carried out and the image information is stored in the image memory. As a result, when the image information of all documents is stored, there are not any un-processed documents on the document stacker of the facsimile apparatus.
After the image information of a document is stored in the image memory, the circuit of the partner for transmission is checked again to find out whether it is occupied or not. When connection is made, the image information stored is transmitted automatically to the partner.
When the circuit can not be connected despite re-dialing, the period when the facsimile apparatus can not be used is only the re-dialing period, which means that other queuing time can be utilized for transmitting other documents to other partners.
Therefore, it is possible to obtain a high utilization efficiency (the rate of operation) of the apparatus.
When the partner circuit is available, transmission is started directly without storing the image information in the image memory. In this case, it is possible to verify the state of transmission based on the completion stamp or the verification stamp because transmission completion-stamping is carried out on the document.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram showing an example of a communication control means of the facsimile apparatus of the invention.
FIG. 2 is a flow chart showing an example of a transmission procedure routine related to the invention.
FIG. 3 is a flow chart showing another example according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
An example of the facsimile apparatus of the invention will be explained in detail, and illustrated in the accompanying drawings.
FIG. 1 is a schematic flow diagram showing an example of the communication control means 10 incorporated in the facsimile apparatus of the invention having an image memory.
The communication control means is provided with CPU 1 which controls the document-reading, the control of telecommunication lines and transmitted-document-recording.
The image information of a document is read by reading means 2, the image information thus read is inputted into CPU 1 through interface 3, and then is transmitted to the partner via net control circuit (NCU) 4 and communication line (telephone line, leased line etc.) 5, after the necessary image processing is made on the image information.
The image information read by reading means 2, is stored, when necessary, in RAM 9 which forms an image memory. The image information thus stored can be transmitted.
The received image information signals, after being processed by CPU 1, are supplied to the recording means 7 via the interface device 6, and then the received image information is recorded onto heat-sensitive recording paper.
Numeral 8 represents ROM wherein various kinds of control programs are stored. The transmission program related to the invention is stored in ROM 8. The numeral 9, on the other hand, represents RAM which can be used as an image memory as stated above.
Further, the input from the keys of operation portion 12 provided on the facsimile apparatus main body is fed into CPU 1 via interface device 13, and thereby processing operation corresponding to the input is carried out. Numeral 15 represents a display portion and the state of display thereon is controlled through the interface device 14.
The display portion 15 is used for the display corresponding to the input from operation portion 12 as well as for the display of warnings such as that for overflow of image memory 9.
Similarly, buzzer 17 is also controlled, via interface device 16, by the command signals from CPU 1. Buzzer 17 is also used as a means for informing an operator of an insufficient capacity, such as an occurrence of an overflow of image memory 9.
FIG. 2 is a flow chart showing an example of a transmission program related to the invention. In this transmission program routine 20, the transmission-start key is operated (step 21) when the documents are placed on the document-stacker provided on the main body of the apparatus.
Following this, connection to the partner circuit is attempted, and immediately upon connection, a document is fed and the document's image information is transmitted to the partner. After that, a completion stamp is affixed on each document (steps 22-24).
If, however, the partner circuit is occupied, a determination is made as to whether the image information on the document needs to be stored in image memory 9. When an operator does not set the key operation for storing the image information, namely when the check key is not operated, the document is ejected without any processing (steps 25 and 26). In this case, therefore, the document information is transmitted after the same transmission procedure is conducted again.
When the check key is operated, on the other hand, the document's information may be stored in the image memory 9 when the documents are fed sheet by sheet. A predetermined time after the image information on the last document is stored in image memory 9, the partner circuit is checked again to determine whether it is occupied (steps 27 and 28).
When it becomes possible to transmit, following attempted connections, the image information from image memory 9 is read out and is then transmitted. However, when the partner circuit is occupied during retransmission the partner circuit is checked again, after the period of predetermined time (step 29).
Thus, the partner circuit is checked to determine whether it is occupied, as in the conventional procedure, but it is also possible to use the facsimile apparatus in the period before the re-dialing procedure in step 28, because no un-processed documents are on the document-stacker. Therefore, it is possible to transmit other documents to other partners through an ordinary procedure. After other such transmissions and after the predetermined time has elapsed the partner circuit is checked again to determine whether it is occupied. If it is not occupied, the image information is transmitted.
Therefore, the utilization efficiency of the apparatus is improved.
When the partner circuit is not occupied, as stated above, the documents' information is transmitted without storing it in image memory. This assures that completion stamping is carried out without fail. It is possible, therefore, to easily confirm the documents which have been transmitted.
When the partner circuit is occupied, on the other hand, the image information of documents may be stored in image memory 9 through the operation of a check key. Image information is then transmitted to the partner after the storage of all information is completed.
In the present invention, it is also possible to automatically store the image information in image memory 9, whether or not the check key is operated when the partner circuit is occupied. It is also possible, in the example in FIG. 2, to determine whether to store in image memory 9 in step 25.
In the automatically storing case, after the transmission-start key is operated, everything is done automatically. When the partner circuit is not occupied, the stored image information is read out and transmitted automatically. Thus the operation by an operator becomes very simple because documents are transmitted without requiring special operation.
An explanation will now be made on a monitoring system for use in the above facsimile apparatus according to the invention. When a communication line of a partner circuit is occupied, image information on documents is stored in image memory 9, and then the stored image information is transmitted to the partner circuit when the communication line is connected by a redialing operation carried out a predetermined time later. Through this monitoring system, it is preferable to enable a user to confirm operation results wherein the operation results relating to the image information-storing operation, the transmission operation, and so on are indicated on display portion 15 and/or printed by recording means 7.
FIG. 3 is a flow chart showing an example of a transmission procedure in a facsimile machine incorporating the monitoring system. In FIG. 3, the same operations as those in FIG. 2 are represented by the same step numbers.
According to this embodiment, when documents are fed to reading means 2 to read image information due to occupation of a partner circuit and the read image information has been stored in image memory 9, some suitable messages representing the reading and storing results are indicated with an ID. No. of the documents on the display portion and/or printed on a receiving slip by recording means 7 (step 30).
During the course of storing the image information in image memory 9, when an overflow takes place in image memory 9, an overflow warning indication appears on the display portion 15 and buzzer 17 sounds, telling an operator of an insufficient capacity for the memory.
In this case, some of the documents remain unstored due to the insufficient storage. It is also possible, however, to indicate on display portion 15 the number of pages for which the information has already been stored. In this case, after transmitting the stored information corresponding to the aforesaid number of document pages, the unprocessed documents may be stacked again for transmission. It is naturally possible, in the case of the insufficient storage, to cancel all of the image information stored in image memory 9 and to take the same transmission procedure again.
The image information stored in image memory 9 at step 27 is subjected to redialing operation a predetermined time later by the same manner as mentioned in FIG. 2, (step 28). In this step, a working situation of a communication line of a partner circuit is checked, and when it is detecled that the line is unoccupied, the apparatus then is connected to the partner circuit, and the stored image information is transmitted.
In step 29, transmission results are checked. When the transmission operation for the stored image information has been completed, messages representing the completion of transmission operation are printed with the ID. No. of the corresponding documents on a transmission slip and the transmitted image information is deleted from image memory 9, (steps 31 and 32).
When the image information has not been transmitted, a judgment is made as to whether the transmission failure is caused by a machine error in the partner circuit, such as a shortage of recording paper, machine failures and so on, (step 33).
As a result, when the transmission failure is not caused by the machine error, the cause of it is deemed due to the occupation of the partner circuit. Accordingly, a check is made on the number of times the partner circuit has been redialed (step 34). When the number of redialing times has not reached a specified maximum number, process in the flow chart as shown in FIG. 3 returns to step 28 and re-transmission is attempted again by redialing operation carried out a predetermined time later.
In the case where the machine error is detected in step 33 or the number of redialing times is detected to reach the specified maximum number in step 34, the transmission to the partner circuit is deemed impossible. Thus the stored image information is deleted from image memory 9 and error messages are printed with an ID number of the corresponding document on the transmission slip.
As mentioned above, according to the invention, operation results with respect to image information are checked by the monitoring system. Then monitoring results are indicated as suitable messages on the display portion or printed on a slip by the recording means. Therefore operations required by the user may be simplified.
An explanation will now be made on an embodiment wherein a message with respect to an operation result, such as a storing result of reading and storing image information on document into image memory 9, a transmission result of dialing and transmitting the stored image information to a partner circuit and so on, is indicated on display portion 15 or printed by recording means 7. According to this embodiment of the invention, an operator may confirm the operation result through the message.
In the invention, as stated above, when the partner circuit is occupied, the image information on documents are stored once in the image memory and when the partner circuit is available and connected, the image information is read out of the image memory for the automatic transmission.
Owing to the aforesaid arrangement, when the partner circuit is not occupied, it is possible to transmit without utilizing image memory 9. Therefore, it is possible to conduct the completion stamping and easily verify whether the transmission has been carried out or not. Even when image memory 9 is used, the processes thereafter are all conducted automatically. Thus the operating procedure is greatly simplified.
Even when the circuit is occupied, it is possible to transmit other documents to other partner circuit except during the period for re-dialing the partner circuit, because no unprocessed documents are stacked on the document-stacker.
As a result, it is possible to vastly improve the utilization efficiency of a facsimile apparatus, which is an outstanding feature. | A facsimile apparatus is provided having a image reader for photoelectrically reading information on a document and a communication device for calling a recipient and for transmitting the read information through a communication line. There is further provided a memory for storing the information. In this configuration, when the communication line of the recipient is detected as being occupied, the communication device stores the read information into memory once, and when the communication line is connected with that of the recipient by redialing operation, the communication device transmits the stored information from the memory. | 8 |
There are no related patent applications.
This application did not receive any federal research and/or development funding.
TECHNICAL FIELD
Generally, the present invention relates to a safety device used in training firefighters and other damage control personnel. More specifically, the invention is a strap device that attaches to a hose nozzle and prevents a bale of the hose nozzle from being inadvertently opened during training exercises. The strap device comprises a plurality of loops arranged around a handle of the nozzle, the nozzle body and the bale to prevent fire fighting material from being discharged from the nozzle. One or more of the loops may include a fastener means that quickly detaches to decouple the loop from the nozzle part about which it is arranged. The device may also comprise a visual indicator, such as a flag, that is attached to the device to indicate that it has been visually inspected during a training exercise.
BACKGROUND OF THE INVENTION
Damage control and firefighting personnel periodically perform training operations to train for fighting fires. During these training operations, the personnel practice deploying firefighting equipment, such as hose gear and nozzles. In the modern Navy, all sailors are trained in damage control and firefighting operations.
During these training exercises, problems arise when personnel inadvertently open a bale on a nozzle to allow water, foam, or other firefighting agent to flow from the hose nozzle. Currently, many naval personnel use bungee cords, or other such elastic bands, wrapped around the firefighting nozzle during training exercises to prevent inadvertently opening it. Industrial sized paper clips with attached rags are typically utilized to indicate that a hose crew has been inspected. Other problems arise when these bungee cords and paper clips break, are lost, or fall off during the training exercise.
The instant invention overcomes the problems associated with the aforementioned prior art by providing a safety device that prevents the bale from the hose nozzle from being inadvertently opened. A visual indicator device is also provided for assisting inspectors in verifying that a hose crew has been inspected and passed the inspection. Moreover, the safety device may be easily removed by disengaging a detachable loop from the bale. The bale may be operated and the safety device is removed from the hose nozzle.
SUMMARY OF THE INVENTION
A nozzle safety training device includes a plurality of straps, preferably two, arranged around a hose nozzle to prevent the bale from being inadvertently opened during training exercises. An agent test satisfactory indicator is arranged on the device for simulating an agent being expelled from the nozzle during damage control training. The indicator may be a flag of a specific color fastened at an end of the device. For example, a green indictor may simulate salt water agent or a white flag may mean an aqueous filming agent.
The device is preferably formed from a plurality of cloth strips or webbing and preferably includes permanent stitching that fastens the cloth strips together. One of the strips of webbing includes a fastener, preferably of hook and loop material, that forms a dis-engageable or detachable loop which fastens to a bale of a hose nozzle for securing it in a closed or off position. Another loop of material or webbing is arranged at an opposite end of the device for fastening the device to a handle of the hose nozzle. The nozzle includes a flow end that passes through a further loop of material to secure the device to the body of the nozzle.
It is an object of the invention to provide a nozzle safety training strap device that prevents the bale of a nozzle, on which the device has been deployed, from being inadvertently opened during a training exercise.
It is another object of the invention to teach a safety training device that is an agent test satisfactory indicator that shows when a hose crew has passed an inspection.
It is a further object of the invention to provide a safety training device for use in training exercises. The safety training device includes a pair of loops that are connected together via at least one strap. The first loop surrounds a handle on the nozzle handle and the second loop surrounds the body of the nozzle. A strip of material extends from one side of the second loop to the other side to pass across the end of the nozzle from which water or fire fighting agent is expelled or discharged. A third loop includes a fastener and is detachable to allow the third loop to be easily and quickly fastened or coupled to the bale to prevent the nozzle from being accidentally actuated during training exercises. However, the bale third loop may be decoupled from the bale by pulling a loose end to disengage the fastener.
It is another object of the invention to teach a safety training device that is made from common materials such as strips of cloth or webbing that are stitched to create a pair of permanent loops of material for attaching the device to a hose nozzle. A fastener is included for creating a loop that surrounds the bale to prevent it from being inadvertently actuated during a training exercise. In a preferred embodiment, two strips of webbing are used. A permanent loop is formed at one end of a longer strip of webbing via stitching. The second end of the longer strip includes a fastener such as hook and loop material that forms a non-permanent loop. A fastener is also provided at the tip of the second end for securing a visual indicator thererto. The shorter strip of webbing is formed into a circular loop and fastened to the longer strip between the first and second ends. Permanent stitching preferably secures the circular loop to the longer strip.
The above and further objects, details and advantages of the invention will become apparent from the following detailed description, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the instant invention.
FIG. 2A is a perspective view of the instant invention affixed to a nozzle that is in a closed position.
FIG. 2B is perspective view of the instant invention affixed to a nozzle that is in the open position.
FIG. 3 is a perspective view of the invention on a nozzle and including a visual indicator attached to the device indicating that the hose crew has been inspected.
FIG. 4A is a prior art nozzle in the closed position.
FIG. 4B is a prior art nozzle in the open position.
DETAILED DESCRIPTION OF THE INVENTION
The embodiments of the invention and the various features and advantageous details thereof are more fully explained with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and set forth in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and the features of one embodiment may be employed with the other embodiments as the skilled artisan recognizes, even if not explicitly stated herein. Descriptions of well-known components and techniques may be omitted to avoid obscuring the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those skilled in the art to practice the invention. Accordingly, the examples and embodiments set forth herein should not be construed as limiting the scope of the invention, which is defined by the appended claims. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.
In a preferred embodiment of the invention, as shown in FIG. 1 , the device 1 includes a first strip of material 10 having two ends 10 A and 10 B . The first strip of material 10 is formed into a first loop 12 via permanent stitching 25 at a first end 10 A thereof. The handle 103 of the nozzle 100 is inserted into the first loop 12 of material 10 . The second end 10 B of the first strip of material 10 includes a fastener 29 , having complementary portions 29 A and 29 B that arranged on respective portions of material 10 , as shown in FIG. 2B . These complementary portions 29 A, 29 B engage one another to create a dis-engageable loop 13 that fastens about the bale 105 of the hose nozzle 100 . The second end 10 B of the first strip of material 10 is tugged on to detach the dis-engageable loop 13 from the bale 105 . A second strip of shorter material 15 is formed in a loop 16 . The flow end 101 of the hose nozzle 100 passes through this loop 16 and into a basket end 17 of the device 1 that includes a basket comprising the loop 16 and a basket strip of material 14 that is formed to partially encapsulate flow end 101 . The second strip of material 15 is fastened in two places to the first strip of material 10 via permanent stitching 25 using a square pattern as shown. Fastener element 29 B is preferably attached on a top end of the material 10 where it overlaps the loop 16 . A second set of permanent stitching 25 is provided along a bottom of the loop 16 to secure it to the first strip of material 10 . The region of material between these permanent stitching 25 comprises strip of material 14 which encapsulates a portion of flow end 101 . As indicated by the drawings, one of the complementary portions 29 A, 29 B of the fastener 29 is arranged near or atop the area of permanent stitching that couples the first 10 and second 15 strips of materials together. The strips of material may be a nylon webbing, cloth or other such durable material that can be fastened with permanent stitching.
As indicated, FIG. 1 shows a safety training device 1 that preferably includes a pair of strips of webbing 10 , 15 that are formed to include a basket 17 which comprises the loop 16 formed from a shorter strip of material 15 and strip 14 of a longer strip of webbing 10 . The flow end 101 of hose nozzle 100 rests within this basket 17 when the hose nozzle 100 is being inspected or when not in use. An indicator flag 40 , as shown in FIG. 3 , may be included on the second end 10 B of the first strip of webbing. The indicator flag includes a complementary strip of fastening material that fastens to fastener strip 30 A.
Strip fastener 30 A is arranged at the second end 10 B of first strip of webbing 10 . This end 10 B is pulled upwards to separate fastener 29 into complementary portions 29 A and 29 B. These complementary portions 29 A, 29 B are permanently fastened to the same face of the material 10 via stitching 25 . When mated together, the fastener 29 creates loop 13 that secures about bale 105 to prevent it from being opened, as shown in FIG. 2A .
Permanent stitching 25 that secures complementary fastener 29 B to one face of material 10 also preferably secures material 10 to material 15 . That is, one half of fastener 29 is arranged directly above where one of material 10 , 15 overlaps the other and is permanently stitched together. Permanent stitching 25 is also provided on a bottom of the loop 16 to secure materials 10 , 15 together. Another loop 12 is formed at a first end of the material 10 , as shown.
As can be understood by FIG. 2A , which is a perspective view of the instant invention affixed to a nozzle that is in a closed position, the device 1 is arranged around a hose nozzle 100 . In this instance, the handle 103 is passed through loop 12 . Discharge end 101 passes through loop 16 and into basket 17 . The second end 10 B of material 10 is passed through an opening 102 of the bale 105 . The complementary strips 29 A, 29 B of fastener 29 are brought together to create the detachable loop 13 around bale 105 . This loop 13 prevents bale 105 from being inadvertently opened. Loop 13 is disengaged by tugging on end 10 B to decouple complementary strips 29 A, 29 B from one another, as shown in FIG. 2B . Bale 105 may be pulled rearward to allow fire retardant to flow from discharge end 101 . As can be understood from FIG. 2B , discharge material will cause basket 17 to be removed from discharge end 101 . The operator can then slip loop 12 downward and away from handle 103 .
FIG. 3 is a perspective view of the invention 1 on a nozzle 100 and including a visual indicator 40 attached to the device 1 indicating that the hose crew has been inspected. In this instance, the visual indicator 40 includes a complementary fastener strip 30 B (not shown) that mates with fastener strip 30 A to couple the visual indicator 40 to the second end 10 B of material 10 . Visual indicator 40 may be provided in a variety of colors. The visual indicator is used as an agent test satisfactory indicator and is arranged on the device for simulating an agent being expelled from the nozzle during damage control training. The visual indicator may be a flag of a specific color fastened at an end of the device. For example, a green indictor may simulate salt water agent or a white flag may mean an aqueous filming agent. Other identification indicia may be provided on each visual indicator.
FIG. 4A is a prior art nozzle in the closed position. FIG. 4B is a prior art nozzle in the open position. In FIG. 4B , the nozzle 100 includes a discharge end 101 that discharges fire retardant material (not shown) when the bale 105 is forced rearward away from the discharge end 101 . A hose end 104 is coupled to a hose that provides pressurized fire retardant that flows through nozzle 100 . In FIG. 4A , the bale 105 is shown in the open position to correspond with FIG. 2A when the device 1 is typically installed on the hose nozzle 100 . The body of the nozzle includes that part of the nozzle to which the bale 105 and the handle 103 attach. A valve is arranged within the body to be closed when the bale 105 is in a defined position such as the forward position shown when the nozzle is in the closed position.
While the invention has been described with respect to preferred embodiments, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in limiting sense. From the above disclosure of the general principles of the present invention and the preceding detailed description, those skilled in the art will readily comprehend the various modifications to which the present invention is susceptible. Therefore, the scope of the invention should be limited only by the following claims and equivalents thereof. | A safety device includes a first loop arranged around a handle of a nozzle. via a first strip of material. A second strip of material extends across the second A second loop is arranged around a body of the nozzle and adjoins the first loop loop. A first strip of material includes a fastener for creating a third loop that prevents a bale of the nozzle from being opened. The safety device may include a visual indicator arranged at a free end of the first strip of material for indicating that a firefighting crew maintaining the nozzle has passed inspection and the type of agent the fire hose expels. | 8 |
FIELD OF THE INVENTION
This invention relates to the analytical testing of the coolant water circulating throughout a water cooled and moderated nuclear fission reactor plant. The invention comprises an improvement in such analytical testing including a preanalysis adjustment of water specimens sampled for testing.
BACKGROUND OF THE INVENTION
Typical boiling water and pressurized water nuclear fission reactor plants comprise a nuclear fission reactor having an enclosed body of heat producing fissionable fuel which is associated with steam driven turbines for propelling electrical generators. Reactor coolant water is continuously circulated through the system during normal operation to carry the produced heat energy away from the fuel core for the formation of steam to be expended in work driving a turbine. The thus utilized coolant water and/or steam condensate is in turn cycled back into the nuclear reactor to repeat its heat energy transferring circuit substantially endlessly. This repeated circulation of coolant water throughout a vast network of vessels and conduits composed of different materials, chemical and physical conditions including temperatures, pressures and radiation, and products of radiation commonly containing corrosive agents, requires constant monitoring of the chemistry of the circulating coolant water from different locations throughout the system.
Common analytical testing procedures for nuclear fission reactor coolant water comprises sequentially sampling individual water specimens from many diverse locations throughout the nuclear reactor coolant water circulating system. The sampled coolant water specimens are each transferred through a network of coolant water sample conveying conduits or tubes to a central or consolidated water analyzing instrument. The water testing instrument analyses each specimen in sequence for determining the presence of designated constituents such as chloride, sodium, potassium, sulphate, etc. and their concentrations dissolved within the coolant water samples. This soluble constituent data derived from various coolant water samples provides a basis for modifying the water chemistry as a means of controlling the content of components causing corrosion or radiation and the like potentially deleterious conditions within the coolant water circulating system.
Typical of nuclear reactor coolant water testing or monitoring apparatus and water analysis procedures is the disclosure of U.S. Pat. No. 4,472,354, issued Sep. 18, 1984. The disclosure and contents of the aforesaid U.S. Pat. No. 4,472,354 is incorporated herein by reference.
SUMMARY OF THE INVENTION
This invention constitutes an improvement in an analytical testing procedure wherein samples of nuclear reactor coolant water are sequentially collected at different locations throughout the coolant circulation system and each sample specimen conveyed to an analytical instrument for evaluation. The improvement of the invention includes a preanalysis adjustment in the pH value of the sampled coolant water specimens to stabilize ion concentrations.
OBJECTS OF THE INVENTION
It is a primary object of this invention to provide an improved means for testing the soluble contents of nuclear reactor coolant water.
It is an additional object of this invention to provide an analytical testing procedure which more accurately evaluates soluble ions within the coolant water of a nuclear fission reactor cooling system.
It is another object of this invention to provide a method of testing for the soluble contents of coolant water from different locations throughout the coolant circuit.
It is still another object of this invention to provide a procedure for analyzing nuclear reactor coolant water for its soluble contents which inhibits unbalancing of an equilibrium in solution of the coolant with any metal ion solutes derived from contact with metal vessels and conduits.
It is also an object of this invention to provide a method of testing for the soluble ion contents of nuclear reactor coolant water comprising preconditioning test samples to a pH level for stabilizing ion equilibriums.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 of the drawings comprises a flow diagram of a nuclear fission reactor illustrating a system for taking samples of coolant water from throughout the coolant circuit and testing the water samples in an analytical instrument;
FIG. 2 of the drawings comprises a cross sectional view of one type of apparatus for carrying out the improvement of this invention; and
FIG. 3 of the drawing comprises a cross sectional view of another type of apparatus for carrying out the improvements of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 in particular, a water cooled and moderated nuclear fission reactor plant 10 comprises a reactor pressure vessel 12 housing a core of heat producing fissionable fuel (not shown). The heat producing fuel core is submerged within coolant water which continuously cycles through a reactor coolant circuit 14 for the purpose of carrying heat energy away from the fuel core in the form of pressurized hot water or steam to perform work.
Typically the heat energy transferring reactor coolant circuit 14 includes a steam conduit 16 for conveying steam generated from coolant water within the pressure vessel 12 to a steam driven turbine 18 which in turn rotates a generator 20 for producing electrical power. Spent steam and any condensation water therefrom is passed to steam condenser 22 to transform all water vapor to liquid, whereupon the condensation water is returned through return conduit 24 to the reactor pressure vessel 12, completing the cycle and for reuse as coolant water and moderator.
The coolant water/steam repeats this circuit substantially endlessly to continuously transfer heat energy from the fuel core to a means for converting it into work throughout a normal operating term.
There is an inevitable formation and accumulation of water born contaminants comprising corrosive agents and products, and fission produced and radioactive components, as well as other potentially detrimental ingredients throughout the coolant water and its circuit. This progressive concentration of contaminants within the coolant circuit system presents a potentially damaging condition with respect to equipment, especially valves and pumps, and/or can result in a build up of radioactive material which is hazardous to operating personnel.
In order to evaluate and deal with such accumulations of damaging water born containments it has become customary to routinely analyze the soluble contents of the coolant water from several different locations throughout the coolant circuit of a nuclear reactor plant. Coolant water testing means have evolved into the use of a common or consolidated water analyzing instrument provided with a network of sample drawing and conveying conduits or tubes for taking water specimen samples from multiple significant locations throughout the coolant water circulating system and transferring the specimens to the common instrument 26. For example, referring to FIG. 1 of the drawing, a series of conduits such as 28, 30, 32, 34 and 36, are provided for taking sample specimens of coolant water sequentially from a variety of different locations within the coolant water circuit and conveying the sampled water specimens to a common conduit 28 for sequential introduction into a single analytical water testing apparatus 26 for their respective evaluations.
Such a water testing arrangement provides for sequential taking of sample water specimens at different locations, and conveying streams of these sampled water specimens to and sequentially through the analytical water testing instrument for evaluation of predetermined likely solute ingredients carried in the reactor coolant water.
In the employment of nuclear reactor coolant water testing means such as described above, it was discovered that the pH levels of high purity sample specimen streams affects equilibriums established between the sample carrying conduit walls and solute ions, such as copper and zinc, contained in the flowing water or liquid solvent phase. Specifically as the pH of the conveyed water drops, namely becomes more acid, the ions affected are released from the metal conduits. Conversely, as the pH of the conveyed water increases, namely becomes more basic, the affected ions deposit/absorb/adsorb on the exposed surfaces of metal conduits. This pH induced condition has been determined to cause erroneous transients in on-line chemistry instrumentation, or when using grab sampling techniques. This shortcoming can be significant when undertaking to monitor multiple sample streams conveyed through a common conduit when the pH values vary from sample specimen to sample specimen.
This invention constitutes an improvement in analytical testing procedures wherein samples of nuclear reactor coolant water are collected at different locations throughout the overall reactor coolant circuit and sequentially conveyed to an analytical testing instrument for evaluation. Examples of such procedures are given above and in the previously cited U.S. patent. The improvement of the invention includes a preanalysis adjustment in the pH values of the sampled water specimens.
Specifically this invention comprises a system and procedure for acidifying or lowering the pH level of a flowing sample specimen of nuclear reactor coolant water, or process stream thereof, while being carried within a conduit or tube from the sampling site to the analytical testing apparatus. The means of this invention comprise injecting an acidifying gas, such as carbon dioxide, or liquid acids, into the flowing stream of the sampled water specimen. Thus, as the applied acidifying gas dissolves within the coolant water specimen, the pH level of the water is lowered, thereby reducing deposition of cations on the walls of any downstream conduit, tubing or sample bottles. The pH level is controlled by the partial pressure of the acidic gas administered in the injected/absorbed gas mixture. The pH range should be thus adjusted to about 3.0 pH to about 5.5 pH, and preferable about 4.0 pH to about 4.5 pH.
Acidic gases suitable for lowering the pH level of coolant water specimens include carbon dioxide, hydrogen sulfide, chlorine, etc. An effective acidifying gas is one that will not contaminate the coolant water sample specimen with additional ions of those that are being monitored by the test. Carbon dioxide gas (CO 2 ) is ideal in meeting all such requirements, and is preferred. Carbon dioxide is readily soluble in water, forming a bicarbonate-carbonic acid equilibrium which effectively lowers the pH level of the water. The following equation illustrates this equilibrium reaction:
2H.sub.2 O+CO.sub.2 ⃡H.sub.2 O+H.sub.2 CO.sub.3 ⃡H.sub.3 O.sup.+ +HCO.sub.3.sup.-
Laboratory evaluations of this procedure of the invention have demonstrated that the memory effect for metal ions such as copper, can be reduced to negligible levels within a specimen of coolant water following through either stainless steel or teflon tubing by means of injecting carbon dioxide gas directly into the specimen. Other acidifying gases, such as H 2 S, Cl 2 , HNO 3 , etc., or aqueous solutions thereof, have shown similar effects in reducing ion memory.
FIG. 2 of the drawing illustrates a schematic plan for a pH reducing device 38 in accordance with this invention. As shown in this figure, coolant water sample specimens pass from the nuclear reactor coolant circuit 14 through a conduit such as 30 or 32 or 34 to conduit 28 entering the pre-conditioning, pH adjusting device 38. A suitable acidifying gas such as carbon dioxide is thus injected into the coolant water specimen flowing through device 38 thereby lowering the pH level of the water test specimen. The pre-conditioned water specimen passes from the device 38 to a gas removing device 40 through conduit 42 to expel excessive gas from the specimen. The gas removing device 40 eliminates excessive gas by means of a gas permeable, tubular membrane. The pre-conditioned specimen flows from the device 40 through conduit 44 into the analytical water testing apparatus 26 for routine determination of certain ions pursuant to convention analytical practices.
FIG. 3 of the drawings illustrates one means for injecting an acidifying gas such as carbon dioxide into a specimen of sampled coolant water flowing through a pre-conditioning, pH adjusting device 38. This embodiment of the invention comprises a gas impermeable instrument housing 46 having a passage for the flow of a coolant water specimens therethrough. The housing 46 includes a coolant water specimen inlet 48 and outlet 50 from the housing 46, and a gas permeable tubing 52 connecting the inlet and outlet 48 and 50 and passing across the housing 46 for transporting a flow of a water specimen from conduit 28 therethrough. Gas impermeable housing 46 additionally contains a gas inlet connection 54 and a gas outlet connection 46 for the introduction of an acidifying gas into the interior of the housing and the discharge of the gas therefrom. Thus a flow of an acidifying gas can be passed through the gas impermeable instrument housing 46, and around exterior of the gas permeable tube 52 carrying therein the flowing coolant water specimen passing through the housing 46. The acidifying gas permeates through the permeable tubing 52 becoming absorbed into the water passing therethrough, reducing the pH level thereof.
EXAMPLE
An example of the problem and resolution for the practice of this invention is as follows: Two categories of samples were prepared in two liter teflon bottles. A blank (specimen 1) was drawn from the same ultrapure water supply as the standard (specimen 2). The standard was prepared by adding neutral salts to give a concentration of 5 parts per billion each for copper, zinc and nickel. The pH of each specimen was adjusted to approximately 7 and a slight over pressure of nitrogen was in each specimen bottle to prevent carbon dioxide adsorption.
The sample specimens were selected by an automatic valve which was located as close as practical to the bottles. An acidification chamber was located immediately down stream of the valve. Carbon dioxide was introduced in the bottom of the chamber and bubbled through a small volume of the water specimen samples and vented to atmosphere for the acidification test.
A coil of teflon tubing (1/8" 0.D.×1/16" I.D.×70 ft.) was used as being the most inert test material available. This tubing represents the common specimen carrying duct between the sample manifold and the water testing or analysising ion chromatograph apparatus.
Excess specimen flow was removed at the inlet to the ion chromatograph sample pump and measured for pH. Total flow was approximately 6 ml per minute with exactly 1.5 ml per minute of the flow through the pump.
The sample sequence was programmed to alternate between blank and standard specimen sets. Each specimen set consisted of five analysis, and the data was plotted. The "before" acidification copper results are an excellent demonstration of the phenomenon of "ion memory effect" whereby absorbed metal ions are released into solution will desorb from conduit walls when solutions of a lower concentration of the same ions passes therethrough, resulting in inaccurate readings. The effect of this phenomenon was greatly reduced for the "after" acidification when carbon dioxide was bubbled through the water specimen at a rate of approximately 2 cc per minute.
This invention has an apparent buffering effect on pH and a constant flow carbon dioxide will result in a relatively stable pH when the water flow rate is varied by a factor of 4. Observed values have been pH 4.0 to 4.3 when specimen flows of 6 ml per minute to 24 ml per minute.
The means of this invention are contamination free in terms of trace metals, easy to store and have a long shelf life, and safer to handle than acids.
This invention provides an uncomplicated and reliable means for achieving pH level reductions on-line with minimal contaminations of a sample specimen. This means at best eliminates or at least reduces the ion memory effect of sample specimens. Moreover, the invention controls the pH of a coolant water stream independent of flowrate, and improves the accuracy and precision for on-line sample specimen monitoring instrumentation. The preferred acidifying gas carbon dioxide is non-toxic, acidic or basic and requires minimum precautions for safe handling, and the pH reduction achieved with this gas is limited by the solubility of carbon dioxide in water and the partial pressure of carbon dioxide in the acidifying gas thereby providing an easily controllable procedure. | Water testing means for monitoring circulating water coolant in service within a water cooled nuclear reactor system is disclosed. The invention is an improvement in such water testing means and comprises a preconditioning of selected sample specimens of water with a pH adjustment for inhibiting unbalancing an equilibrium in solution of water coolant with ion solutes. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a wireless communication method of communication time adjustment in Bluetooth devices, and more particularly, to a wireless communication method of a wireless communication device for performing one-to-multi Bluetooth communication by adjusting a time period for a communication between a master device and slave devices when the master device intends to communicate with the slave devices. The present application is based on Korean Patent Application No. 2002-51520, filed Aug. 25, 2001, which is incorporated herein by reference.
[0003] 2. Description of the Related Art
[0004] The Bluetooth technology enables transmission of information such as text data, voice data and video data at a maximum speed of 1 Mbps within a distance range of 10-100 m.
[0005] Bluetooth devices, which can communicate with one another through the Bluetooth communication method, construct a communication connection through processes like inquiry scan, page, page scan, etc. During these processes, master and slave devices are determined according to functions thereof.
[0006] In order to construct a new connection with another Bluetooth device, each Bluetooth device has to adjust its operational clock and frequency pattern with each other. And among the processes for constructing a new connection among the Bluetooth devices, the inquiry process is that the master device repeatedly sends out its operational frequencies to the slave devices in order to have the slave devices adjust their frequency patterns to the master device.
[0007] The inquiry scan is performed by the slave devices, in which the slave devices detect the received frequencies and synchronize to the detected frequencies. The page is the process in which the master device sends out a clock signal so that the slave devices can adjust to the operational clock of the master. In the page scan, the slave devices detect the received clock and synchronize to it. Through these processes, a connection called a ‘piconet’ is constructed, having more than one slave device connected to the master device.
[0008] According to the currently suggested Bluetooth communication method, one master device can connect to up to seven slave devices in an active state, for bilateral communication. Further, in order to connect a new slave device to the piconet, the master device first disconnects one of seven active slave devices from the piconet and then connects the new slave device to the piconet in an active state.
[0009] According to the Bluetooth communication method, the master and slave devices operate in several modes, i.e., in an active mode in which the master device communicates with the slave devices on a regular basis, and hold, sniff and park modes for power saving. Usually, the hold mode is used when there is no need to send data in a relatively long period of time. In sniff mode, the master and slave devices transmit and receive data only for a predetermined period of time. During the park mode, the slave device periodically communicates with the master device in order to ask for maintenance of synchronization with the master device and shift to the active mode.
[0010] The slave device, which operates in one of the hold, sniff and park modes, repeatedly operates in its communication mode according to a predetermined cycle. Although the slave device operating in hold mode actually operates one time, since the slave device in hold mode wakes up at a predetermined time to communicate with the master device, it is considered that the slave device in hold mode also operates periodically like slave devices in other modes.
[0011] When all the connected slave devices shift their modes, the master device determines communication time of the respective slave devices through communication and negotiation with the slave devices. Accordingly, through the negotiation with the master device, all the connected slave devices are set to operate according to a predetermined periodical cycle. That is, according to the conventional communication method, the master and slave devices communicate for a time and according to a cycle that are fixed by mutual negotiations among the master and slave devices until the slave devices shift their modes.
[0012] Here, the operational cycles of each slave device in each mode can vary according to the negotiation with the master device. Accordingly, although the slave devices begin communication with the master device at different times and according to different cycles in the one-to-multi communication of the Bluetooth communication, different communication of the respective slave devices sometimes causes coincidental overlap of communication of a plurality of slave devices within a certain period of time. And the slave devices communicating with the master device simultaneously may cause interference in the communication with the master device. Accordingly, due to the communication interference among the slave devices, the slave devices can be disconnected from the master device.
SUMMARY OF THE INVENTION
[0013] The present invention has been made to overcome the above-mentioned problems of the related art, and accordingly, it is an object of the present invention to provide a wireless communicating method that uses a wireless communication device, by which a master device shifts operational mode and communicates in the shifted mode with slave devices that are set to be controlled by the master device, and the slave devices of different communication time and cycles in the respective modes are prevented from communication interferences and cut-off.
[0014] The above object is accomplished by a wireless communication method according to the present invention, comprising the steps of a) determining whether communication parameters satisfy a precondition for communication before a master device communicates with a slave device in a corresponding mode, the communication parameters being required for the slave devices to communicate with the master device, the precondition being that the slave devices should communicate with the master device without overlapping of communication time thereof; and b) controlling the communication of the slave devices according to the corresponding mode by differently setting operation information of the slave devices according to the corresponding mode, when determining that the communication parameters satisfy the precondition for communication.
[0015] Preferably, after the step a), there is provided the step of a-1) changing the communication parameters according to the master device negotiations with the slave devices so that the communication parameters can satisfy the precondition, when determining that the communication parameters do not satisfy the precondition; and a-2) determining whether new communication parameters changed through negotiations with the slave devices fall within a range that is changeable by the slave devices. The step b) is performed when it is determined that the new communication parameters fall within the range changeable by the slave devices.
[0016] According to the wireless communication method according to a preferred embodiment of the present invention, there is provided a step c) of transmitting a message to a user and to the slave device requesting the communication, indicating that it is impossible to control according to the corresponding mode of the slave device requesting the communication, when determining in the step a-2) that the new communication parameters do not fall within the range changeable by the slave device.
[0017] The corresponding mode between the master device and the slave devices include at least one of a power save, an inquiry, an inquiry scan, a page and page scan. The power save corresponding mode includes at least one of a park mode, a hold mode and a sniff mode. Also, the communication parameters include at least one of a start point of operation, a time of operation, and a cycle of the corresponding mode, for the communication between the master device and the slave devices.
[0018] There are three preconditions for communication. The first precondition is that a total sum of the time of operation and the cycle of the slave devices have to satisfy a predetermined value. The second precondition is that the cycle of slave devices according to the communication parameters has to be as integral-number of times greater than a minimum cycle, the minimum cycle being a base value of the cycle. The third precondition is that the minimum cycle has to be greater than a total sum of 1) a total sum of the operation time and 2) a total sum of maximum time for the slave device to re-receive a certain packet or to receive a next packet from the master device, while the minimum cycle is less than a supervision timeout value which is a maximum allotment of time for the determined slave device to connect to the master device.
[0019] Meanwhile, after the step b), there is provided a step of maintaining a connection between the slave device and the master device until the communication completes, when the time of operation of the slave devices ends due to the corresponding mode shift in a condition that the communication is not completed between the master device and the slave device.
[0020] According to the present invention, by determining the potential for each slave device to operate based on the precondition for communication, setting the communication parameters for the corresponding slave device to satisfy the precondition, and by differently setting the communication start points of the corresponding slave devices, the interference and cut-off of communication with the slave devices of different communication time and cycle in corresponding mode can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above-mentioned object and the feature of the present invention will be more apparent by describing the preferred embodiment of the present invention by referring to the appended drawings, in which:
[0022] [0022]FIG. 1 is a block diagram showing the status of connection between a master device and slave devices in respective modes;
[0023] [0023]FIG. 2 is a flowchart showing a wireless communication method that is capable of preventing communication interference and cut-off in a one-to-multi wireless communication between the master device and slave devices according to the present invention; and
[0024] [0024]FIG. 3 is a view showing one example in which the master device sets operation start points of respective slave devices according to the step S 18 of FIG. 2 for periodic communications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] From now on, the present invention will be described in great detail by referring to the appended drawings.
[0026] [0026]FIG. 1 is a block diagram showing the status of connection between a master device and slave devices in respective modes according to the Bluetooth method. The master device 10 performs an inquiry process in which the master device 10 sends out its operational frequencies through a channel (i.e. through the air) to peripheral slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 . The slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 perform an inquiry scan process in which they are synchronized to the master's operational frequencies received from the master device 10 . Next, the master device 10 performs a page process, sending out its driving timing clock to the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 . Accordingly, the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 perform a page scan process in which they are synchronized to the master's driving timing clock received from the master device 10 .
[0027] Accordingly, the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 connected to the master device 10 through mutual negotiations are divided into active slave devices 21 and 24 that perform an active communication and power save slave devices 22 , 23 , 25 , 26 and 27 that are in a mode that saves power consumption during non-communication periods. The slave devices 22 , 23 , 25 , 26 and 27 in power save mode are again divided into park slave devices 22 and 27 operating in a park mode, hold slave devices 23 and 26 operating in a hold mode and a sniff slave device 25 operating in a sniff mode.
[0028] While the master device 10 and the active slave devices 21 and 24 synchronously communicate in one-to-one basis, the master device 10 can also transmit data to desired slave devices with broadcast packets.
[0029] The park slave devices 22 and 27 communicate with the master device 10 to maintain the synchronization to the master device 10 , and also to ask to shift to the active mode. The communication between the master device 10 and the park slave devices 22 and 27 periodically takes place, and it takes only a very small portion of the total communication time of the master device 10 .
[0030] The hold slave devices 23 and 26 are the devices that shifted to the hold mode through the negotiations with the master device 10 since there was no need for the master device 10 to transmit data for some time. The master device 10 and the hold slave devices 23 and 26 transmit and receive data in a certain amount of time that is pre-arranged in the communication time of the master device 10 . The master device 10 and the sniff slave device 25 communicate by using the time when the communication in active mode does not occur.
[0031] After the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 shift to the respective modes through the mutual negotiations with the master device 10 , again through the mutual negotiations, communication parameters for communication are set according to the communication modes. Accordingly, the master device 10 and the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 in the respective modes perform the communication. The communication parameters include start points of respective modes, operation time for respective modes and cycles of respective modes.
[0032] The park slave devices 22 and 27 , the hold slave devices 23 and 26 and the sniff slave device 25 perform communication with the master device 10 according to their own cycles. Also, the inquiry, inquiry scan, page and page scan, which are performed by the master device 10 and the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 for the connection therebetween, are also performed according to a predetermined cycle.
[0033] [0033]FIG. 2 is a flowchart showing a wireless communication method for performing mutual communications between the master device 10 and the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 in the respective modes, in which the master device 10 adjusts a communication time with the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 for a synchronized connection of the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 . First, before performing a periodic communication with the slave devices 22 , 23 , 25 , 26 and 27 , the master device 10 sets a precondition for communication in such a manner that the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 do not overlap with each other during communication (step S 10 ). After setting the precondition in S 10 , the master device 10 determines whether the currently connected slave device is in the cyclical mode, i.e., any mode that the slave device communicates according to a certain cycle (step S 12 ).
[0034] More specifically, the precondition for communication is that the communications of the periodically communicating slave devices 22 , 23 , 25 , 26 and 27 do not overlap while the slave devices 22 , 23 , 25 , 26 and 27 periodically communicate with the master device 10 according to their own cycles. The first precondition for communication is that, whether they are in operation or will be, the total sum of the communication time of the slave devices 22 , 23 , 25 , 26 and 27 in each mode and according to its cycle should be less than ‘1’. The relation is expressed by the following formula:
Cp 1 Tp 1 + Ch Th + Cs Ts + Ci Ti + Cis Tis + Cp 2 Tp 2 + Cps Tps < 1 [ Formula 1 ]
[0035] where, C is an operation time of slave device in a certain communication mode,
[0036] T: Cycle of slave device in the certain communication mode,
[0037] Cp 1 : Operation time of park slave device,
[0038] Tp 1 : Cycle of park slave device,
[0039] Ch: Operation time of hold slave device,
[0040] Th: Time of time-out of hold slave device,
[0041] Cs: Operation time of sniff slave device,
[0042] Ts: Cycle of sniff slave device,
[0043] Ci: Operation time of slave device in inquiry operation,
[0044] Ti: Cycle of inquiry of slave device,
[0045] Cis: Operation time of slave device in inquiry scan operation,
[0046] Tis: Cycle of inquiry scan of slave device,
[0047] Cp 1 : Operation time of slave device in page operation,
[0048] Tp 1 : Cycle of page of slave device,
[0049] Cps: Operation time of slave device in page scan operation, and
[0050] Tps: Cycle of page scan of slave device.
[0051] If
Cp 1 Tp 1 + Ch Th + Cs Ts + Ci Ti + Cis Tis + Cp 2 Tp 2 + Cps Tps
[0052] equals ‘1’, it means the master device 10 keeps communication with the slave devices along a temporal axis without a pause. And it also means that there is no time to vary the communication parameters including the communication cycle of the slave devices 21 , 22 , 23 , 24 , 25 , 26 and 27 . In order to prevent a communicational problem, therefore, the formula 1 always has to be met.
[0053] The second precondition of communication is that the cycles of the slave devices 22 , 23 , 25 , 26 and 27 should be an integral-number of times greater than the predetermined minimum periodic cycle (Tb). The relation is expressed by the formula 2:
[0054] [Formula 2]
Ti=NTb
[0055] where, T is a cycle of slave device,
[0056] i: Operational modes of slave devices (park, hold, sniff, inquiry, inquiry scan, page, page scan),
[0057] N: Natural number, and
[0058] Tb: Predetermined minimum cycle.
[0059] The third precondition of communication is that the predetermined minimum cycle Tb should be greater than a total time value (Ta), while it should be less than a supervision timeout value sTo (Formula 3). Here, the Ta is the sum total of the maximum time T 2 required for a certain slave device to re-receive a certain packet or a next packet from the master device 10 . Also, the sTo is the maximum allotment of time required for the slave devices 22 , 23 , 25 , 26 and 27 to connect to the master device 10 .
[0060] [Formula 3]
Ta<Tb<sTo
[0061] where, Ta: T 1 +T 2 .
[0062] If it is determined that the slave device does not operate according to a certain cycle in S 12 , the master device 10 and the slave device communicate according to the mode corresponding to the non-cyclical communication mode (step S 14 ). If it is determined in S 12 that the slave device operates according to a certain cycle, the master device 10 determines whether the communication parameters, which are set according to the negotiations with the slave device, satisfy the precondition of communication (step S 16 ).
[0063] If it is determined that the communication parameters as set satisfy the precondition of communication in S 16 , the master device 10 sets communication start points differently according to the communicational connection to the corresponding slave devices in the respective communication modes (step S 18 ). When the communication start points of the slave devices are set differently in S 18 , the master device 10 controls the slave devices so that the communication can be performed periodically according to the corresponding communication modes and also based on the differently-set start points of the slave devices (step S 20 ).
[0064] When it is determined that the communication parameters as set in S 16 do not satisfy the precondition of communication, the master device 10 varies the communication parameters stored in the master device 10 according to the precondition of communication (step S 22 ). At this time, the master device 10 determines whether the communication parameters, which are varied through the negotiation with the slave device, are in the range that is changeable (step S 24 ).
[0065] When it is determined that the communication parameters as changed fall within the changeable range in S 24 , the master device 10 and the slave device set the changed parameters for communication with each other in a certain communication mode (step S 28 ). When the communication parameters for the master device 10 and the slave device are set in S 28 , the master device 10 performs steps S 18 and S 20 . When it is determined that the changed communication parameters exceed the changeable range in S 24 , the master device 10 transmits a message to the corresponding slave device, indicating that it is impossible for the slave device to shift mode and operate in a new mode (step S 26 ).
[0066] Accordingly, the communications of the respective slave devices do not overlap, and until the completion of the communication by the slave device in active mode, the slave device is not disconnected from the master device 10 which mainly occurs due to supervision timeout, i.e., the maximum timeout allotted for the communication connection.
[0067] [0067]FIG. 3 is a view showing one example, in which the master device 10 controls the communication start points of the slave devices so that the slave devices can periodically communicate. FIG. 3 shows the park slave device 22 of minimum cycle Tb, the hold slave device 23 having a periodic timeout value 2Tb twice as long as the minimum cycle of the park slave device 22 and the sniff slave device 25 having a cycle three times as long as the minimum cycle of the park slave device 22 , transmitting data packets periodically under the control of the master device 10 . In this situation, the master device 10 sets communication points of the slave devices differently according to their initial modes.
[0068] Accordingly, the slave devices can communicate with the master device 10 in the respective modes, without an overlap of communication.
[0069] According to the present invention, before communicating with the slave devices in cyclical modes, the master device 10 determines whether the communication parameters for controlling the communication between the master device 10 and the slave devices satisfy the communicational prerequisite. If satisfying, the master device 10 sets different communication start points for the respective slave devices and performs the communication with the slave devices. Thus, the communication interference and cut-off, that sometimes happen during the communications of the slave devices of different communication start points and cycles, can be prevented.
[0070] So far, the preferred embodiment of the present invention has been illustrated and described. However, the present invention is not limited to the preferred embodiment described here, and someone skilled in the art can modify the present invention without departing from the spirit of the present invention claimed in the claims section. | A wireless communication method capable of preventing communication interference and cut-off in one-to-multi wireless communication. The wireless communication method has the steps of: determining as to whether communication parameters satisfy a precondition for communication before a master device communicates with a slave device in a corresponding mode, the communication parameters being required for the slave devices to communicate with the master device, the precondition being that the slave devices should communicate with the master device without overlapping of communication time thereof; controlling the communication of the slave devices according to the corresponding mode by differently setting operation information of the slave devices according to the corresponding mode, when determining that the communication parameters satisfy the precondition for communication; and maintaining a connection between the slave device and the master device until the communication completes, when the time of operation of the slave devices ends due to the corresponding mode shift when the communication is not completed between the master device and the slave device. Accordingly, the interference and cut-off of communication with the slave devices of different communication times and cycles in corresponding mode can be prevented. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to liquid valves and, more particularly, to a miniature valve which is applied to a liquid control system and is used for switching the direction of the liquid flow, or communicating and blocking the liquid flow.
[0003] 2. Discussion of the Related Art
[0004] Miniature valves includes multiple types. Based on the valve structure, they can be generally divided into isolated mode and non-isolated mode; while based on the driving structure, it can be divided into direct-acting mode, lever mode and priority mode. A sealed mode of the miniature valve generally refers to annular seal. Conventional isolated mode, lever-structure and annularly sealed valves are disclosed in U.S. Pat. Nos. 6,003,552, 5,205,323 and 5,199,462. A conventional isolated mode, direct-acting and annularly sealed valve is disclosed in U.S. Pat. No. 4,944,487.
[0005] However, these valves disclosed in U.S. Pat. Nos. 6,003,552, 5,205,323 and 5,199,462 have following shortcomings. Firstly, the liquid chambers thereof have a rather complicated shape, thus resulting in leftover and large dead areas therein. Secondly, when switched, the movement of the valve films in these valves results in rather violent liquid fluctuations in pipelines. Thirdly, these valves can be driven by solenoid only. The valve disclosed in U.S. Pat. No. 4,944,487 is subjected to such shortcomings as poor capability of enduring liquid pressure, solenoid drive and narrower application scope.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide an improved miniature valve without interior dead area and having slight effect on liquid fluctuation when switching channels.
[0007] The present invention realizes the above object by providing a miniature valve, which includes a valve body and a driver positioned thereon. The valve body includes a supporting device, a valve seat, a valve film and a rocker. The valve seat has a first partition wall and defines a first channel and a second channel. The first channel and the second channel are spaced by the first partition wall. The supporting device and the valve seat are connected and together define a chamber therebetween. The valve film, an elastic film set in the chamber, divides the chamber into a liquid chamber and an installing chamber. The valve film has size configured to cover the two channels and the first partition wall. The rocker having a lever structure is rotatablely positioned in the chamber via a shaft and has a force-receiving end and a first force-exerting end, wherein the first force-exerting end is configured to be able to press against the valve film. The force-receiving end and the first force-exerting end respectively locate at two sides of the shaft. The rocker defines a first position and a second position. When the rocker locates at the first position, the first force-exerting end presses a portion of the valve film facing the first partition wall on the first partition wall so as to separate the liquid chamber from the first channel and communicate the liquid chamber with the second channel; when the rocker locates at the second position, the pressed portion of the valve film disengages from the first partition wall so that the first channel, the liquid chamber and the second channel communicate.
[0008] The rocker further comprises a second force-exerting end locating at the same side of the shaft as the first force-exerting end, and the second force-exerting end is configured to be able to press against the valve film.
[0009] The valve seat further defines a third channel adjacent to and communicating with the second channel and further defines a second partition wall spacing the second channel and the third channel. The valve film has a size configured to cover the third channel and the second partition wall. When the rocker locates at the second position, the second force-exerting end presses a second portion of the valve film facing the second partition wall on the second partition wall.
[0010] The shape of the rocket is approximately in a Y-shape, with the first force-exerting end and the second force-exerting end locating at one end of the rocket, while the force-receiving end locating at the other end of the rocket. The mid portion of the rocket rotatablely engages with the shaft.
[0011] The supporting device tightly presses a periphery of the valve film on the valve seat.
[0012] Each of the partition walls has a plane configured for contacting the valve film when the valve film is pressed thereon.
[0013] The miniature valve further comprises a driven bar as a transmission element, wherein the driven bar movably installed in the installing chamber moves along a direction perpendicular to the axis direction of the shaft, with one end thereof connecting to one end of an elastic element and the other end thereof connecting to an output portion of the driver. The other end of the elastic element presses against a chamber wall of the installing chamber. The driven bar is connected with the force-receiving end of the rocker at approximately the mid portion via a pivot, and the rocker is configured to swing back and forth between the first utmost position and the second utmost position depending on a drive force of the driver and a restoring force of the elastic element.
[0014] The driver is selected from the group consisting of a solenoid-driving device and a cylinder-driving device.
[0015] Each of the channels is configured to form a streamline flow channel together with the liquid chamber in a communicating state.
[0016] The present invention further provides a miniature valve, which includes a valve body comprising an inflow channel, an outflow channel and a liquid chamber; and a close assembly connecting to the valve body and configured to selectively close the inflow channel and the outflow channel. The close assembly comprises a driver, a rocker and a valve film. The rocker is driven by the driver to move, so that the movement of the rocker acts on the valve film to make the valve film selectively close the channel.
[0017] The rocker and the valve film are separate components, and the valve film is elastic, which locates in the liquid chamber and has a size configured to cover the inflow channel and the outflow channel. It should be pointed out that the term “separate” used herein is in contrast with the interconnected rocker and valve film in the prior art. Though the rocker and valve film according to the present invention are not fixedly interconnected, they may contact with each other at certain positions.
[0018] One end of the rocker connects to a transmission element of the driver via a pivot, and the other end of the rocker is configured to exert pressure on the valve film, so that the valve film being tightly pressed on the wall of a selected channel separates the liquid communication between the selected channel and the liquid chamber.
[0019] The outflow channel comprises a first outflow channel and a second outflow channel. The rocker in an approximate Y-shape comprises a force-receiving end connected to the driver and two force-exerting ends configured to selectively exert a pressure on the valve film. The force-receiving end can be driven by the driver to move towards a first direction, thereby driving the force-exerting ends to move, so that the force-exerting end adjacent to the first outflow channel tightly presses the corresponding portion of the valve film on a wall of the first outflow channel and thereby separate communication between the first outflow channel and the liquid chamber. The force-receiving end can also be driven by the driver to move towards a direction opposite to the first direction, thereby driving the force-exerting ends so that the force-exerting end adjacent to the second outflow channel tightly presses the corresponding portion of the valve film on a wall of the second outflow channel and thereby separate communication between the second outflow channel and the liquid chamber.
[0020] The driver is selected from a solenoid-driving device and a cylinder-driving device.
[0021] The miniature valve further comprises an elastic element arranged at one side of the force-receiving end of the rocker. When the driver is unactuated, the elastic element presses the rocker to a default position which may be a position either for separating the first outflow channel or a position for separating the second outflow channel.
[0022] The periphery of the valve film is liquid-hermetically fixed at the periphery of the liquid chamber.
[0023] The present invention achieves the following advantageous effect: 1) the flow chamber communicates at least with one channel at the first and the second positions, as a result of which there is no dead area inside the valve. Besides, as the switch of channels is realized by way of elastic distortion occurring when pressure is exerted upon the valve film, and as the valve film moves a short distance during the switch, the influence upon the flowing liquid in the channels is significantly reduced, so that violent fluctuation of the flowing liquid is avoidable. 2) As the periphery of the liquid chamber is sandwiched between the supporting device and the valve seat, the valve film has improved capability of enduring liquid pressure; 3) It is possible to drive the valve via a solenoid-driving device as well as a cylinder-driving device, the valve may be more widely applied. 4) The streamline shape of the liquid channel reduces the flowing resistance.
[0024] Other and further objects of the invention will be apparent from the following drawings and description of preferred embodiments of the invention in which like reference numerals are used to indicate like parts in the various views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Many aspects of the present miniature valve 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 miniature valve. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0026] FIG. 1 is a cross-sectional view of a miniature valve in accordance with the first preferred embodiment of the present invention.
[0027] FIG. 2 is a cross-sectional view of a valve body of the miniature valve of FIG. 1 .
[0028] FIG. 3 is a cross-sectional view of the valve body of the miniature valve of FIG. 1 , showing a rocker of the valve body is in the first position.
[0029] FIG. 4 is a cross-sectional view of the valve body of the miniature valve of FIG. 1 , showing the rocker of the valve body is in the second position.
[0030] FIG. 5 is a cross-sectional view of a valve film and a first partition wall of the miniature valve of FIG. 1 , showing the valve film and the first partition wall are in a disengaging state.
[0031] FIG. 6 is a cross-sectional view of the valve film and the first partition wall of the miniature valve of FIG. 1 , showing the valve film and the first partition wall are in an impacted state.
[0032] FIG. 7 is a cross-sectional view of a miniature valve in accordance with the second preferred embodiment of the invention.
[0033] FIG. 8 is a cross-sectional view of a miniature valve in accordance with the third preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Reference will now be made to the figures to describe the present invention in detail.
[0035] Referring to FIGS. 1 to 6 , a miniature valve in accordance with the first preferred embodiment of the invention is shown. In this embodiment, the miniature valve as shown is a three-way valve comprising a valve body and a driver 23 positioned at a side of the valve body. The driver 23 is advantageously a solenoid acting as a dynamical source. The valve body can switch liquid pipelines under drive of the driver 23 .
[0036] The valve body includes a supporting device 17 , a valve seat 15 , a rocker 5 , a driven bar 1 and a valve film 16 . The supporting device 17 is tightly pressed against the valve seat 15 and defines a chamber together with the valve seat 15 therebetween. The valve film 16 , an elastic quadrate slice, is tightly sandwiched between the supporting device 17 and the valve seat 15 . The valve film 16 divides the chamber into two parts, i.e., a liquid chamber 8 and an installing chamber 24 . The liquid chamber 8 faces to the valve seat 15 and the installing chamber 24 is opposite to the valve seat 15 . Because the valve film 16 can generate distortion upon pressure, the volume of the liquid chamber 8 is variable. In this embodiment, the surface on which the supporting device engages with the valve seat is concave so as to define an installing slot 7 , and the periphery of the valve film 16 is firmly embedded in the installing slot 7 .
[0037] The valve seat 15 defines a first channel 14 , a second channel 12 and a third channel 11 , which channels are juxtapositional (i.e., parallel each other) and communicate with the liquid chamber 8 . The first channel 14 and the second channel 12 are spaced by a first partition wall 13 , while the second channel 12 and the third channel 11 are spaced by a second partition wall 21 . The valve film 16 is large enough to entirely cover the three channels and the two partition walls. It should be noted that the term “cover” herein does not mean to cut off the communication between the channels and the liquid chamber. In order to decrease flow resistance, each of the channels 14 , 12 and 11 is connected with the liquid chamber 8 in a manner that a streamline flow channel is formed. One or two of the three channels can be defined as inflow channel(s), and correspondingly the remaining as outflow channel(s), if necessary. In this embodiment, the second channel 12 is advantageously an inflow channel, and the first channel 14 and the third channel 11 are advantageously outflow channels.
[0038] The supporting device 17 has a shaft 4 positioned therein. The rocker 5 is arranged in the installing chamber 24 and engages with the shaft 4 to construct a lever structure. Specifically, the rocker 5 is approximately in a Y-shape and includes a force-receiving end 3 , a first force-exerting end 18 and a second force-exerting end 6 . The force-receiving end 3 and the force-exerting ends 18 , 6 respectively locate at two sides of the shaft 4 . The first force-exerting end 18 and the second force-exerting end 6 are substantially symmetrical with relation to the shaft 4 , respectively adjacent to the first partition wall 13 and the second partition wall 21 . The force-receiving end 3 is configured (i.e., structured and arranged) for receiving drive force. The valve film 16 locates between the rocker 5 and the two partition walls 13 , 21 , and also locates at the moving tracks of the force-exerting ends 18 , 6 , i.e., the force-exerting ends 18 , 6 is configured to be able to press against the valve film. The rocker 5 has a first utmost position and a second utmost position along its moving track. When the rocker 5 swings between the first utmost position and the second utmost position, the force-exerting ends 18 , 6 alternately press the valve film 16 to contact the two partition walls 13 , 21 . During contacting, surfaces 10 , 9 whereby the two partition walls 13 , 21 joint with the valve film 16 are sealed, and the sealed surfaces 10 , 9 are coplanar.
[0039] The driven bar 1 is installed in the installing chamber 24 and can move along a lengthways direction perpendicular to the shaft 4 and parallel to the sealed surfaces 10 , 9 of the two partition walls 13 , 21 . The driven bar 1 is connected to the force-receiving end 3 of the rocker 5 via a hinge 2 so that the movement of the driven bar 1 can drive the rocker 5 to swing around the shaft 4 in a certain angle range. One end of the driven bar 1 connects to one end of a compression spring 19 , and the other end of the driven bar 1 connects to an output portion 22 of the driver 23 . The other end of the compression spring 19 presses against a chamber wall of the installing chamber 24 so that the compression spring 19 can compel the driven bar 1 to move towards the driver 23 . The driver 23 can compel the driven bar 1 to overcome a force of the compression spring 19 and move towards the compression spring 19 .
[0040] In this embodiment, the sliding direction of the driven bar 1 is defined as the x-axis direction, the axis direction of the shaft 4 as the y-axis direction, and the flowing direction of the liquid in the channels 14 , 12 and 11 as the z-axis direction. A plane defined by the moving track of the rocker parallels to the x-z plane.
[0041] In operation, when the driver 23 drives the rocker 5 to rotate to the first utmost position via the driven bar 1 , the valve film 16 is tightly pressed on the sealed surface 10 of the first partition wall 13 by the first force-exerting end 18 of the rocker 5 , and the valve film 16 disengages from the sealed surface 9 of the second partition wall 21 . As a result, the opening of the first channel 14 is completely blocked by the valve film 16 so that the first channel 14 and the second channel 12 are separated. At the same time, the second channel 12 and third channel 11 are communicated through the liquid chamber 8 . In addition, a bottom surface of the supporting device 17 can support the valve film 16 when the valve film 16 is pressed by a liquid, so that the valve film 16 has enhanced capability of enduring liquid pressure.
[0042] When the driver 23 drives the rocker 5 to rotate to the second utmost position via the driven bar 1 , the valve film 16 is tightly pressed on the sealed surface 9 of the second partition wall 21 by the second force-exerting end 6 of the rocker 5 , and the valve film 16 disengages from the sealed surface 10 of the first partition wall 13 . As a result, the opening of the third channel 11 is completely blocked by the valve film 16 so that the third channel 11 and the second channel 12 are separated. At the same time, the first channel 14 and second channel 12 are communicated through the liquid chamber 8 .
[0043] When the rocker 5 swings back and forth between the first utmost position and the second utmost position depending on a drive force of the driver 23 and a restoring force of the compression spring 19 , the first force-exerting end 18 and the second force-exerting end 6 alternately press the valve film 16 on the first partition wall 13 and the second partition wall 21 . Therefore, communications and switch between different channels are achieved. It is to be understood that other elastic elements, such as elastic rubber etc., can be used instead of the compression spring 19 . Further, the driver 23 can also be used independently for driving the rocker 5 back and forth without the compression spring 19 .
[0044] Referring to FIG. 7 , a miniature valve in accordance with the second preferred embodiment of the invention is shown. The second embodiment, essentially similar to the first embodiment, only differs in that the driver 23 ′ is a cylinder driver that can be hydraulically driven.
[0045] Referring to FIG. 8 , a miniature valve in accordance with the third preferred embodiment of the invention is shown. The third embodiment, essentially similar to the first embodiment, only differs in that the miniature valve of the third embodiment is a two-way valve. Specifically, the valve seat 15 ′ of the miniature valve defines a first channel 14 ′ and a second channel 12 ′, which are spaced by a first partition wall 13 ′.
[0046] In operation, when the driver (e.g., the driver 23 or 23 ′) of the miniature valve drives the rocker 5 ′ to rotate to the first utmost position via the driven bar 1 ′, the valve film 16 ′ is tightly pressed on a sealed surface of the first partition wall 13 ′ by a first force-exerting end 18 ′. As a result, the opening of the first channel 14 ′ is completely blocked by the valve film 16 ′ so that the first channel 14 ′ and the second channel 12 ′ are separated. When the driver drives the rocker 5 ′ to rotate to the second utmost position via the driven bar 1 ′, the valve film 16 ′ disengages from the sealed surface of the first partition wall 13 ′ and the second force-exerting end 6 ′ presses down the valve film 16 ′, such that the first channel 14 ′ and second channel 12 ′ are communicated.
[0047] Each of the above-mentioned miniature valves has following advantages. Firstly, because the liquid chamber communicates with at least one of the channels, there is no dead area inside the miniature valve. Secondly, the switching of the channels is achieved through the elastic distortion of the valve film, the valve film has a small moving distance, so the miniature valve has a slight effect on liquid fluctuation when switching channels.
[0048] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | The present invention relates to a miniature valve, which includes a valve body comprising an inflow channel, an outflow channel and a liquid chamber, and a close assembly comprising a driver, a rocker and a valve film. The close assembly connects to the valve body and is configured to selectively close the inflow channel and the outflow channel. The rocker can be driven by the driver to move, so that the movement thereof acts on the valve film and makes the valve film selectively close the channel. The rocker and the valve film are separate components. The valve film, an elastic film locating in the liquid chamber, has a size configured to cover the inflow channel and the outflow channel. The miniature valve according to the present invention doesn't have interior dead area and has a slight effect on liquid fluctuation when switching channels. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to “IO Clamping circuit Method Utilizing Output Driver Transistors”, U.S. patent application Ser. No. 10/145,408, filed May 14, 2002, by Benzer.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] [Not Applicable]
SEQUENCE LISTING
[0003] [Not Applicable]
MICROFICHE/COPYRIGHT REFERENCE
[0004] [Not Applicable]
BACKGROUND OF THE INVENTION
[0005] The present invention relates to a system and method for protecting sensitive circuitry from an electrical voltage overstress. More specifically, the present invention relates to a system and method for protecting sensitive circuitry from an electrical voltage overstress by employing an IO clamping circuit utilizing output driver transistors.
[0006] Many integrated circuits or ICs include bi-directional Input/Output Pads (alternatively referred to as “IO PADs” or “PADS”) coupled to the sensitive IC core logic circuitry. Such sensitive circuitry must be protected from electrical voltage overstress that appears on the IO PADs when driven by external circuitry via a bus. Known solutions have included using a variety of active or passive clamps that may occupy a large amount of silicon area. This invention attempts to utilize existing circuitry to provide voltage clamp protection against electrical voltage overstress, thereby reducing the overall die area consumed.
[0007] The problem of electrical voltage overstress becomes significantly worse when using technologies where only low voltage devices (less than about 3.0V maximum operating voltage, more specifically about 2.5V for example) are available. In addition, advancements in integrated CMOS technologies lead to smaller gate lengths and thinner oxides, thereby reducing the operating voltages of the transistors to less than or below many existing design specification requirements. One such example is the 4.6V electrical voltage overstress specified for the USB 1.1 transceiver. Some of the known active and passive clamping devices do not sufficiently protect low voltage devices under conditions as defined in such design specification requirements.
[0008] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0009] Features of the present invention may be found in limiting the voltage seen at the IO PAD of an integrated circuit, thus preventing voltage overstress. More specifically, the present invention relates to using the output driver devices of an integrated circuit as a clamping circuit. Using the output devices as a clamping circuit limits the voltage seen at the IO PAD, thereby preventing a voltage overstress on the low voltage (2.5V for example) output transistors.
[0010] In one embodiment, a first voltage comparator detects when the PAD voltage exceeds the positive rail or VDD and sends a control signal to enable a p-channel output driver device, thereby providing a clamp to the positive rail. Conversely, if the PAD voltage falls below the negative rail or VSS, a second voltage comparator detects this condition and enables an n-channel output driver device, thereby providing a clamp to the negative rail. If the output driver devices have a sufficiently low on resistance (i.e., large current carrying capability), voltage overstress protection may be obtained while minimizing the additional die area that would otherwise be required.
[0011] An embodiment of the present invention relates to a clamping circuit adapted to prevent voltage overstress. In this embodiment, the clamping circuit comprises a comparator device adapted to detect when at least one voltage passes at least one or more voltage levels (two or more voltage levels for example). It is contemplated that, in one embodiment, the comparator device is adapted to detect when the voltage exceeds a first predetermined voltage level, and, in another embodiment, the comparator device is adapted to detect when the voltage falls below a second predetermined voltage level.
[0012] It is contemplated that the first or second voltage comparators may be separate devices or a single device adapted to detect when one or more voltages fall outside of a pre-determined range. The first voltage comparator is adapted to detect when a voltage exceeds a first predetermined voltage, while the second voltage comparator is adapted to detect when the voltage falls below a second predetermined voltage, thereby preventing voltage overstress on the devices.
[0013] One embodiment of the present invention relates to a clamping circuit for protecting against voltage overstresses. In this embodiment, the clamping circuit comprises first and second voltage comparators. The first voltage comparator is adapted to detect when a selected voltage exceeds a first predetermined voltage. The second voltage comparator is adapted to detect when the selected voltage falls below a second predetermined voltage.
[0014] It is contemplated that one embodiment of the clamping circuit may further comprise an output driver circuit adapted to be enabled by a signal transmitted by the first and/or second voltage comparators. The output driver circuit may further comprise one or more output driver devices. Said output driver device(s) may comprise a transistor device adapted to provide a path to a first voltage rail (a p-channel transistor device adapted to provide a clamp to a positive rail for example) or a path to a second voltage rail (an n-channel transistor device adapted to provide a clamp to a negative rail for example).
[0015] Yet another embodiment of the present invention relates to an integrated circuit. In this embodiment, the integrated circuit comprises a PAD and a clamping circuit. In this embodiment, the clamping circuit comprises at least one comparator device adapted to detect when at least one voltage passes one or more voltage levels, thereby preventing overstress on the PAD.
[0016] Yet another embodiment of the present invention relates to an integrated circuit comprising a PAD and a clamping circuit. In this embodiment, the clamping circuit comprises a first voltage comparator adapted to detect when a voltage exceeds a first predetermined voltage and a second voltage comparator adapted to detect when the voltage falls below a second predetermined voltage, thereby preventing a voltage overstress on the PAD.
[0017] It is contemplated that one embodiment of the integrated circuit may further comprise drive logic circuitry communicating with a data node. Moreover, the integrated circuit may comprise a pre-driver circuit, including one or more pre-drive transistor devices, communicating with at least the clamping circuit.
[0018] Yet still another embodiment of the present invention relates to an integrated circuit. In this embodiment, the circuit comprises a driver logic circuit, a pre-driver circuit communicating with at least the driver logic circuit, a PAD and a clamping circuit communicating with at least the PAD and the pre-driver circuit. Furthermore, the clamping circuit comprises a first voltage comparator adapted to detect when a PAD voltage exceeds a first predetermined voltage and a second voltage comparator adapted to detect when the PAD voltage falls below a second predetermined voltage, thereby preventing voltage overstresses on at least the PAD.
[0019] Another embodiment of the present invention relates to a method of protecting a device against voltage overstress. In this embodiment, the method comprises detecting when a voltage passes one or more voltage levels, thereby preventing voltage overstress on the device.
[0020] Yet another embodiment of the present invention relates to a method of protecting a device against voltage overstress. In this embodiment, the method comprises detecting when a voltage exceeds a first predetermined voltage, and detecting when the voltage falls below a second predetermined voltage, thereby preventing voltage overstress on the device.
[0021] Yet still another embodiment of the present invention relates to method of protecting a device against voltage overstress. In this embodiment the method comprises determining an operating range of a PAD voltage and operating the IO PAD in a normal mode if the PAD voltage is less than a first voltage but greater than a second voltage. The method further comprises clamping the PAD voltage to a first rail if the PAD voltage is greater than a first voltage level and clamping the PAD voltage to a second rail if the PAD voltage is less than a second predetermined voltage level. In one such embodiment, the first voltage is VDD and the second voltage is VSS.
[0022] These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0023] FIG. 1 illustrates a circuit diagram of an integrated circuit having an output stage of an IO PAD;
[0024] FIG. 2 illustrates a circuit diagram of an integrated circuit similar to that of FIG. 1 having an output stage of an IO PAD and using diodes as clamping devices;
[0025] FIG. 3 illustrates a circuit diagram of an integrated circuit similar to that of FIG. 1 having an output stage of an IO PAD and using transistor devices as clamping devices;
[0026] FIG. 4 illustrates a circuit diagram of a portion of an integrated circuit using one embodiment of a clamping circuit in accordance with the present invention;
[0027] FIG. 5 illustrates a high level flow chart of one method of protecting a device from overstress voltage in accordance with the present invention; and
[0028] FIGS. 6A and 6B illustrate a detailed flow chart of one method of protecting a device from overstress voltage in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The following description is made with reference to the appended figures.
[0030] In accordance with one embodiment of the present invention, the output driver devices of an integrated circuit are used as a clamping circuit. Using the output driver devices as a clamping circuit limits the voltage seen at the IO PAD and prevents voltage overstresses on the low voltage (2.5V for example) devices coupled to the IO PAD.
[0031] FIG. 1 illustrates a circuit 10 comprising two transistor devices, a PMOS device 12 , and an NMOS device 18 coupled to output PAD 20 . In this example, these devices form a sensitive tri-stated output driver circuit. One or more pre-driver devices pull the gate of device 12 up to VDDO (i.e., P=VDDO) and pull the gate of device 18 to VSS (i.e., N=VSS) to tri-state the output. It is contemplated that PAD 20 is coupled to, and may be driven by, external circuitry via a bus (not shown).
[0032] Such circuit 10 must be protected from electrical overstresses that appear on PAD 20 when driven by the external circuitry. The problems associated with electrical voltage overstresses increase as geometries decrease in advanced sub-micron technologies In one example illustrated in FIG. 1 , the voltage on PAD 20 (alternatively referred to as the “PAD voltage”) may range from about −1V to about 4.6V according to the USB 1.1 specification, the complete subject matter of which is incorporated herein by reference in its entirety.
[0033] FIG. 2 illustrates circuit 200 similar to that illustrated in FIG. 1 comprising two transistor devices, a PMOS device 212 , an NMOS device 218 , and output PAD 220 . PAD 220 is shown connected to circuit 200 . Again, it is contemplated that PAD 220 is coupled to, and may be driven by, external circuitry via a bus (not shown).
[0034] FIG. 2 further illustrates one example of a known clamping device (a diode 222 having a threshold voltage or V D of about 0.7V for example). In the illustrated embodiment, the PAD voltage needs to be ≧VDDO+V D for the diode 222 to turn on and clamp the PAD voltage to prevent voltage overstresses. For example, if the diode V D =0.7V and VDDO=3.6V then the PAD voltage must be ≧VDDO+V D or 3.6V+0.7V=4.3V for the diode 222 to turn on and clamp the PAD voltage. If PAD=4.2V for example and VDDO=3.6V, then in this example, the voltage across the diode=PAD−VDDO or 4.2V−3.6V=0.6V. However, as this voltage across the diode is less than the diode threshold voltage, the diode will not turn on, and thus the clamping circuit in this example will not operate.
[0035] FIG. 2 further illustrates one example of a known clamping device (a diode 224 having a threshold voltage or V D of about 0.7V for example). In the illustrated embodiment, the PAD voltage needs to be ≦VSS−V D for the diode 224 to turn on and clamp the PAD voltage to prevent voltage overstresses. For example, if the diode V D =0.7V and VSS=0V then the PAD voltage must be ≦VSS−V D or −0.7V for the diode 224 to turn on and clamp the PAD voltage to VSS. If PAD=−0.6V for example and VSS=0V, then in this example, the voltage across the diode=−0.6V. However, as this voltage across the diode is less than the diode threshold voltage, the diode will not turn on, and thus the clamping circuit in this example will not operate.
[0036] FIG. 3 illustrates circuit 300 similar to that illustrated in FIGS. 1 and 2 comprising two transistor devices, a PMOS device 312 , an NMOS device 318 , and output PAD 320 . PAD 320 is shown connected to circuit 300 . Again, it is contemplated that PAD 320 is coupled to, and may be driven by, external circuitry via a bus (not shown).
[0037] FIG. 3 further illustrates one example of a known clamping device (a PMOS transistor device 324 having a threshold voltage or V TP of about 0.6V for example). In the illustrated embodiment, the PAD voltage needs to be ≧VDDO+V TP for device 324 to turn on and clamp the PAD voltage to prevent voltage overstresses.
[0038] FIG. 3 further illustrates one example of a known clamping device (an NMOS transistor device 326 having a threshold voltage or V TN of about 0.6V for example). In the illustrated embodiment, the PAD voltage needs to be ≦VSS−V TN for device 326 to turn on and clamp the PAD voltage to prevent voltage overstresses.
[0039] Embodiments of the present invention relate to a clamping circuit comprising at least one but generally two or more voltage comparators, an integrated circuit including a clamping circuit comprising at least one but generally two or more voltage comparators and a method of protecting against electrical voltage overstresses. Integrated circuits typically include one or more IO PADS, where such IO PADS generally contain an output driver circuit comprising at least a pull-up device or a pull-down device (or some combinations thereof). Pre-driver devices may drive these pull-up and pull-down devices according to logic states generated by driver logic circuitry.
[0040] FIG. 4 illustrates a circuit diagram of a portion of an integrated circuit 400 having PAD 440 and using one embodiment of a clamping circuit 410 in accordance with the present invention. In the illustrated embodiment, the integrated circuit 400 includes one or more transistor devices, a PMOS or p-channel pull-up transistor device 414 and an NMOS or n-channel pull-down transistor device 412 (alternatively referred to as “clamping pre-drive transistor devices”). The integrated circuit 400 further comprises an output driver circuit 426 comprising two transistor devices, one PMOS or p-channel transistor device 428 and one NMOS or n-channel transistor device 430 . While two devices 428 and 430 are illustrated, it is contemplated that output driver circuit 426 may comprise only one of the two illustrated devices, one device that performs the functions of the illustrated devices, both devices or some other combination (more than two devices for example).
[0041] A pre-driver circuit 416 drives devices 428 and 430 according to logic states generated by driver logic circuitry 418 , which is, in one embodiment, coupled to a data node 420 of the integrated circuit. In one embodiment, the pre-driver circuit 416 comprises at least one but generally two or more pre-driver devices 422 and 424 . While two devices 422 and 424 are illustrated, it is contemplated that the pre-driver circuit 416 may comprise at least one of the illustrated devices, one device that performs the functions of the illustrated devices, both devices or some other combination (i.e., more than two devices for example).
[0042] In accordance with one embodiment of the present invention, the transistor devices 412 and 414 are controlled by one or more signals that are a function of the output of the clamping circuit 410 . In one embodiment, the clamping circuit 410 comprises at least one but generally two or more voltage comparators 432 and 434 . The outputs of the voltage comparators 432 and 434 are used to control the clamping pre-drive transistor devices 412 and 414 respectively, which in turn are used to control the output driver transistors 428 and 430 during an overvoltage or undervoltage condition on the PAD. While two comparators and two clamping pre-drive transistors are illustrated, other embodiments are contemplated comprising one comparator device that compares one or more voltages alone or in some combination with one or more clamping pre-drive transistors, two comparator devices alone or in some combination with one or more clamping pre-drive transistors, three comparator devices alone or in some combination with one or more clamping pre-drive transistors, etc.
[0043] In one embodiment, the positive input of each comparator is connected to PAD 440 and the negative inputs of the first and second comparators 432 and 434 are connected to the positive rail (alternatively referred to as “VDD”) and the negative rail (alternatively referred to as “VSS”), respectively. The comparators may be operational at any time; however, the most critical mode of operation occurs when the output driver transistors (i.e., transistors 428 and 430 ) are tri-stated (i.e., in a high impedance state) and PAD is being driven by an external circuit that may potentially damage the circuitry associated with the tri-stated IO PAD.
[0044] In one embodiment, the first comparator 432 detects when the PAD voltage exceeds the positive rail (VDD) and sends a control signal to enable the p-channel output device 428 (via transistor 412 for example), thereby providing a clamp to the positive rail. Conversely, if the PAD voltage falls below the negative rail (VSS), the second comparator detects this condition and enables the n-channel output device 430 (via transistor 414 for example), thereby providing a clamp to the negative rail. If the output devices have a sufficiently low on resistance (i.e., a large current carrying capability), voltage overstress protection may be obtained while minimizing the additional die area that would otherwise be required using known clamping circuits.
[0045] FIG. 5 illustrates a high level flow chart of one method 500 of limiting the voltage seen at the IO PAD and protecting sensitive circuitry (the output transistors in an integrated circuit for example) from overstress voltages in accordance with the present invention. It is contemplated that, in accordance with one embodiment of the present invention, if VDD>PAD>VSS as illustrated by diamond 510 , the PAD voltage is within the range of normal operation as illustrated by block 512 and the clamping pre-drive transistor devices are off.
[0046] If however, PAD>VDD as illustrated by diamond 513 , a low-impedance path is provided between the output or PAD and VDD, thereby acting as a clamp to VDD as illustrated by block 514 . If PAD<VSS as illustrated by diamond 516 , a low-impedance path is provided between the output or PAD and VSS, thereby acting as a clamp to VSS as illustrated by block 518 .
[0047] FIGS. 6A and 6B illustrate a detailed flow chart of one method 600 of protecting a device (the output transistors in an integrated circuit for example) from overstress voltages in accordance with the present invention. It is contemplated that, in one embodiment, the PAD voltage range may be divided into three regions: (1) VDD>PAD>VSS; (2) PAD>VDD; or (3) PAD<VSS.
[0048] When the PAD voltage is in the first range (i.e., when VDD>PAD>VSS as illustrated by diamond 610 ) the PAD voltage is in the normal operating range as illustrated by block 612 . The clamping pre-drive transistor devices 412 and 414 are off as illustrated by block 614 . In this range, the pre-driver devices 422 and 424 control the output driver transistors 428 and 430 , as illustrated by block 618 .
[0049] If the PAD voltage is not in the first region, it may be in one of the other regions. When the PAD voltage is in the second region in accordance with the present invention (i.e., PAD>VDD as illustrated by block 620 ), the PAD voltage exceeds the positive rail (VDD) and the output of device 432 is high as illustrated by block 622 . When the output of device 432 is high, it pulls the gate of device 412 high, which then pulls the gate of the p-channel output driver 428 low as illustrated by blocks 624 and 626 respectively. Device 428 turns on as illustrated by block 628 , providing a low-impedance path between the output or PAD and VDD, thereby acting as a clamp to VDD as illustrated by block 630 . In this region, the output of comparator 434 is high and device 414 is off.
[0050] When the PAD voltage is in the third region (when PAD<VSS as illustrated by diamond 632 ), the PAD voltage falls below the negative rail and the output of 434 is low as illustrated by blocks 634 and 636 respectively. This pulls the gate of transistor device 414 low which pulls the gate of the n-channel output driver 430 high as illustrated by blocks 638 and 640 . This turns transistor device 430 on as illustrated by block 642 . Turning transistor device 430 on provides a low-impedance path between the output or PAD and VSS, thereby acting as a clamp to VSS as illustrated by block 644 . In this region, the output of comparator 432 is low and device 412 is off.
[0051] It is contemplated that the pre-driver devices (i.e., circuits 422 and 424 ) may try to drive the gates of the output driver transistors to a voltage that opposes the clamping pre-drive transistor devices (i.e., transistors 412 and 414 ) during an overvoltage or undervoltage condition. In one embodiment of the present invention, the pre-driver devices and the clamping circuitry are not active simultaneously thus preventing the pre-driver devices from driving the gates of the output driver transistors to a voltage that opposes the clamping pre-drive transistor devices.
[0052] It is contemplated that noise may exist on the power and ground rails that may falsely activate the clamping circuit. One embodiment of the present invention includes an offset and/or hysteresis in the voltage comparators in the clamping circuit to accommodate such noise on the power and ground rails without activating the clamping circuitry. It is also contemplated that the addition of an offset and/or hysteresis in the comparators in the clamping circuit enables flexibility in adjusting the activation point of the clamping circuitry for a particular application.
[0053] It is contemplated that the clamping circuit, the integrated circuit including a clamping circuit and a method of protecting against electrical voltage overstresses in accordance with aspects of the present invention provides/includes one or more of the following advantages and features: (1) potential die area savings; (2) supplemental or complete protection against electrical voltage overstresses that appear at the IO PADs of an integrated circuit; (3) potentially eliminates the need for alternate clamping devices that tend to have higher clamping voltages and consume more die area; and (4) enables low voltage devices to be used in designs where electrical overstress voltage requirements exceed the maximum operating voltage of the low voltage devices.
[0054] Many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as described hereinabove. | Systems and methods are disclosed for a clamping circuit for protecting against voltage overstresses. One embodiment of the system comprises a first voltage comparator adapted to detect when a selected voltage exceeds a first predetermined voltage and a second voltage comparator adapted to detect when the selected voltage falls below a second predetermined voltage, thereby preventing voltage overstresses. | 7 |
This invention relates to improvements in methods for making mats of fiberous material. More particularly, the invention relates to a method for making continuous strand mats using reciprocating strand feeders while independently controlling both the rate of reciprocation and the rate at which the strands are deposited from the feeders onto a moving conveyor so as to form mats of uniform density and thickness. Still more particularly, the invention relates to the production of improved continuous fiber glass strand mats using the reciprocating devices to be described herein.
BACKGROUND OF THE INVENTION
Glass fibers and glass fiber strands have been used before in the art to produce various types of glass fiber mats for use as reinforcement material. The basic principles of mat-making are well known in the art and are fully described in the book entitled "The Manufacturing Technology of Continuous Glass Fibers" by K. L. Lowenstein, published by the Elsevier Publishing Company, 1973 at pages 234 to 251. Typical processes for making mats of continuous fiber glass strands are also described in U.S. Pat. Nos. 3,883,333 (Ackley) and 4,158,557 (Drummond).
Typically, the mats formed by these processes are needled in order to provide sufficient mechanical integrity to the them. In the needling operation, rapidly reciprocating barbed needles are used to cause the individual glass strands which make up the mat to become entangled with one another thus resulting in a mat that can be subsequently handled and processed. The needling operation typically used is described in U.S. Pat. Nos. 3,713,962 (Ackley), 4,277,531 (Picone) and 4,404,717 (Neubauer, et al.) Mechanical integrity can also be imparted to the mat by depositing a resin on its surface and curing or melting the resin so that individual strands are bonded together.
A particular utility for glass fiber mats is in the reinforcement of resinous or polymeric materials. The presence of a glass fiber mat provides increased strength over that of the unreinforced material. Usually, the mat and molten resin are processed together to form a thermosetting or thermoplastic laminate. Thermoplastic laminates are particularly attractive for use in the aircraft, marine, and automotive industries since they may be reheated into a semi-molten state and then stamped into panels of various shapes such as doors, fenders, bumpers and the like. It is of the utmost importance, however, that the glass mat used to make the laminate be as uniform as possible in both its thickness and fiber density as measured in units of ounces per square foot. If a non-uniform mat is used for reinforcement purposes, the reinforced products produced therefrom may have a substantial variation in their strength since some areas may be weaker due to the lack of glass fiber reinforcement while others may be stronger. Even more important is the need to insure that the glass reinforcement flows or moves freely within the thermoplastic laminate during the stamping operation in order to produce uniform strength properties in the final component.
In the production of continuous strand mats by the aforementioned patented processes, a plurality of strand feeders are positioned above a moving belt or conveyor. The conveyor is typically a flexible stainless steel chain. The strand feeders are reciprocated back and forth above the conveyor parallel to one another and in a direction generally across the width of the moving conveyor. Strands of multiple glass fiber filaments are fed to the feeders from a suitable supply source such as a plurality of previously made forming packages held in a support rack generally known in the art as a creel. Each feeder apparatus provides the pulling force necessary to advance the strand from the supply source and deposit it on the surface of the moving conveyor. In a typical production environment, as many as 12 to 16 such strand feeders have been used simultaneously with one another so as to produce a mat with as uniform a density distribution as possible.
It is also well known in the art that the feeder can act as an attenuator to attenuate glass fibers directly from a glass fiber-forming bushing and eventually deposit the strands so formed directly onto a conveyor as described by Lowenstein, supra at pages 248 to 251 and further illustrated in U.S. Pat. Nos. 3,883,333 (Ackley) and 4,158,557 (Drummond).
An example of a simple traversing mechanism is a feeder mounted on a track where the feeder is caused to reciprocate back and forth by an electric motor capable of reversing directions. The equipment used within this type of configuration has inherent limitations on its mechanical durability. First, the feeders are quite heavy, usually weighing between 30 to 50 pounds. When this heavy apparatus is traversed across the width of the conveyor, the traverse speed is limited due to the momentum of the moving feeder and the impact forces which must somehow be overcome or absorbed upon each reversal of direction. This limitation on the speed at which the feeder may traverse across the width of the conveyor may also limit the rate of mat production. Secondly, this constant reciprocating motion of the feeders causes vibration to occur and this can result in a great deal of wear on the feeder mechanisms and their guides which may eventually lead to mechanical failure.
In U.S. Pat. No. 3,915,681 (Ackley), a reduction in the vibration normally associated with the reversal of a feeder was accomplished by the use of a traversing system in which a feeder was caused to reciprocate back and forth along a track. The feeder was advanced by a continuous chain driven by a motor. The chain had affixed to it an extended member or pin which engaged a slot milled into the carriage of the feeder. The slot was positioned so that its length was parallel to the direction of motion of the chain and had a length substantially greater than the diameter of the pin. Thus, the feeder was caused to reciprocate by the continuous motion of the chain since, as the feeder traveled in one direction, the pin exerted the force necessary to advance the feeder by pressing against the periphery of the slot. When the feeder reversed its direction, the pin slid until it contacted the opposite periphery of the slot at which point motion of the feeder was reversed. When the feeder approached the termination point of its reciprocating stroke, it contacted a shock absorber which decelerated it and absorbed the impact due to the change in momentum. Later, as an improvement on the basic design, these shock absorber members were replaced with gas pistons and a reservoir capable of storing the absorbed energy was used to help accelerate the feeder in the opposite direction (See U.S. Pat. No. 4,340,406 (Neubauer, et al.)).
Although such designs were successful in reducing some of the vibration associated with the reciprocation of the feeders, the pin and slot arrangements introduced additional mechanical components that could fail and cause an interruption in the mat-making process. Also, the shock absorbers and gas pistons were mechanical devices inherently incapable of precise and repeatable acceleration and deceleration rates.
A second problem with the systems taught by the prior art was the inconsistency of the mat produced. In the deceleration/acceleration cycle of the feeders, more glass fibers tended to accumulate on the surface of the conveyor near the terminal end of each traverse stroke thus forming a mat tending to be thicker near its edges than in the more central portions thereof.
The reason for the buildup of glass fibers near the mat edges was because that each time the feeder reversed its direction, it was locally resident for a greater duration of time over those portions of the mat where the deceleration/acceleration cycle occurred, i.e., the edges, than it was anywhere else. As long as the feeder was paying out glass strand at a constant rate during the entire duration of the turnaround cycle, then the edges of the mat could do nothing but accumulate a greater thickness of glass than was present in the interior.
In order to produce a finished mat having a more uniform density, it was often necessary to trim the mat as it left the conveyor. This reduced the efficiency of the process by a significant degree since material lost due to trimming was wasted.
Thus, despite the advances made by the prior art, there still exists a need to (1) more rapidly reverse the feeder apparatus during its turnaround cycle, (2) minimize the mechanical vibration associated with a rapid turnaround of the feeder apparatus, and (3) better control mat uniformity and density.
As will now become evident from the remainder of the disclosure, an improved mat making method is provided which satisfies these needs.
SUMMARY OF THE INVENTION
In accordance with the instant invention, an improvement in methods used to make continuous fiber strand mat using controlled reciprocating strand feeders is disclosed. In particular, the instant invention employs the use of conventional reciprocating strand feeders adapted to independently control both the rate of reciprocation and the rate at which the strands are deposited from the feeders onto a moving conveyor so that mats of more uniform density and thickness are formed. Still more particularly, the invention relates to improvements in the production of two continuous fiber glass strand mats, one having uniform mechanical properties while the other possesses directionally dependent ones.
The use of reciprocating strand feeders to produce mats of strand fibers is well known in the art, however, the typical configuration of the equipment used places inherent limitations on its mechanical durability. First, the traverse speed of the feeders is limited due to their momentum and the impact forces which must somehow be overcome or absorbed upon each reversal of direction. Secondly, this constant reciprocating motion of the feeders causes vibration to occur and this can result in a great deal of wear on the feeder mechanisms and their guides which may eventually lead to mechanical failure.
A second problem has been in the consistency of the mat produced using conventional methods. In the deceleration/acceleration cycle of the reciprocating feeders, more fibers tend to accumulate on the surface of the conveyor near the terminal end of each traverse stroke thus forming a mat which is thicker near its edges than in the more central portions thereof.
In order to produce a finished mat having a more uniform density, it was often necessary to trim the mat as it left the conveyor. If the feeders were traversed more rapidly to avoid thickness build-up near the edges of the mat, then the vibration associated with the turnaround cycle would become more severe.
Therefore, it is an object of the instant invention to minimize the mechanical vibration associated with a rapid turnaround of the feeder apparatus and to better control the uniformity of mat density and thickness across the surface of the mat.
This has been accomplished by the use of electronically controlled brushless stepper motors capable of generating enough torque to overcome the momentum associated with the reciprocating feeders in order to reverse their direction quickly and smoothly. Also provided is a variable speed electric motor used in conjunction with a programmable logic controller and frequency inverter to adjust the rate at which strand is deposited by the feeders onto the moving conveyor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general view of a conventional fiber glass forming process showing a bushing, an applicator and a winder.
FIG. 2 is a perspective view of a bushing, its associated fin coolers, individual tips and fibers emerging therefrom.
FIG. 3 is a perspective view of a typical mat line used to produce needled continuous strand mat.
FIG. 4 is a perspective view of the front end of the mat line of FIG. 3 looking into Section 4--4 also showing in detail various components used in the control of the reciprocating feeders.
FIG. 5 is an elevational view of a reciprocating feeder, stationary deflector and strand being deposited onto a moving conveyor.
FIG. 6 illustrates, in block diagram form, the electrical circuit used to control the acceleration and deceleration of each reciprocating feeder.
FIG. 7 illustrates, in block diagram form, the electrical circuit used to control the rate at which strand is deposited from each reciprocating feeder onto a moving conveyor.
FIG. 8 is a front elevational view of a typical mat line taken along Section 8--8 of FIG. 3 further illustrating the orientation of the components associated with each reciprocating feeder.
FIG. 9 is a side elevational view of a typical mat line configured for making a mat comprised of a layer of randomly oriented strands needled to a layer uniformly oriented, parallel strands.
DETAILED DESCRIPTION OF THE DRAWINGS
With reference to the drawings, FIGS. 1 and 2 illustrate a conventional continuous direct draw process for the production of glass fibers wherein molten glass is fed into the top of a bushing assembly (1) and exits from a plurality of tips or orifices (2) to form individual glass cones or jets which are then cooled and attenuated. The drawing force for the attenuation of the cone or jet into an additional filament may be supplied by either an appropriately powered rotating winder (3) or a reciprocating belt attenuator which grips the glass and projects it onto a desired surface such as a continuous conveyor as disclosed in U.S. Pat. Nos. 3,883,333 (Ackley) and 4,158,557 (Drummond).
The individual glass fibers or filaments (4) (hereinafter referred to simply as "fibers"), once they have been cooled sufficiently so as to essentially solidify, are contacted with a roller applicator (5) which coats them with a liquid sizing composition. This sizing composition helps to impart lubricity to the individual fibers and also usually contains a binder which provides a bonding agent. The chemical characteristics of the sizing composition and binder are such that they are compatible with the intended final use of the glass fibers. When a resin such as a thermoplastic resin is to be reinforced with the fibers, then the binder and/or size normally will also include a thermoplastic resin. On the other hand, when the resin to be reinforced is a thermoset resin, the binder and/or size will also normally include one. Resins such as polyesters, polyurethanes, epoxies, polyamides, polyethylenes, polypropylenes, polyvinyl acetates, and the like may also be used.
Two notable resins which are typically reinforced with continuous glass strand mat are polypropylene and nylon. A preferred binder/size system for glass fibers intended to be used for the reinforcement of polypropylene is the size system disclosed in U.S. Pat. No. 3,849,148 (Temple). When continuous glass strand mat is to be used to reinforce a nylon resin, a preferred binder/size system is that disclosed in U.S. Pat. No. 3,814,592 (McWilliams, et al.).
The fibers (4) are then gathered into single or multiple strands (6) by passing a plurality of individual fibers (4) over a gathering shoe (17). The gathering shoe (7) is typically a graphite cylinder or disc having cut therein a plurality of circumferential grooves equal to the number of individual strands to be formed from the fibers produced by a single bushing. Strand (6) is then wound over a rotating spiral (8) and onto a cardboard forming tube (9) which is rotated by an appropriately powered winder (3). The winder (3) may cause either the forming tube (9), spiral (8) or both to reciprocate back and forth along their axis of rotation so that the strand (6) passing over the spiral (8) is laid down along the length of the forming tube (9). Cooling fins (10) are inserted between adjacent rows of tips (2) with one end of each fin being attached to a manifold (11) through which a cooling fluid, such as water, is pumped. The fins (10) are positioned so as to absorb radiative heat from the individual glass cones and conduct it to the manifold (11) where it is removed by the cooling fluid. The fins also remove some heat radiated by the tip plate (12).
FIG. 3 depicts a conveyor (13) which is an endless perforated belt, preferably a stainless steel chain, continuously driven by spaced drive rollers (14). In commercial applications, chain speeds of up to 12 ft/min or greater have been used. Strands (6) are shown being projected downwardly onto the surface of the conveyor by means of a plurality of strand feeders (15). While only five such strand feeders are shown in the drawing, this is for illustrative purposes only, and the actual number used can be greater or lesser. Feeders in excess of those shown may be employed and, in fact, the applicants have successfully employed as many as 16 such individual strand feeders to lay strand onto the conveyor (13).
As is indicated in FIG. 3, each feeder (15) is traversed across a predetermined width of the conveyor (13) until the conveyor is completely covered with strand. Individual strands (6) may be drawn from a plurality of previously made forming packages (9) or from glass fiber bushings in the manner illustrated in U.S. Pat. Nos. 3,883,333 (Ackley) and 4,158,557 (Drummond).
Loose mat (16) is formed by depositing successive layers of strand (6) onto the moving conveyor (13). The conveyor then passes in the direction shown by the arrow through an oven (17) and into a needling loom (18).
In the prior art, strand (6) was deposited from each feeder apparatus (15) directly onto the moving conveyor. While this technique did produce an acceptable mat, it was later found that the strand so deposited often tended to assume a preferred orientation. To overcome this, the use of deflector plates rigidly attached to each feeder apparatus in such a fashion that the strand would impinge upon them and be deflected randomly onto the conveyor was adopted. This produced a mat having more uniform strength. See, U.S. Pat. No. 4,345,927 (Picone). Another type of rigidly attached deflector such as that disclosed in U.S. Pat. No. 4,615,717 (Neubauer, et al.) was later developed to divide the strand into a plurality of filamentary arrays that would be deflected and deposited onto the surface of the conveyor in the form of elongated elliptical loops.
More recently, it has been shown that the use of adjustable stationary deflectors (19) attached to the frame of the mat-making apparatus resulted in an improvement over the prior art while also reducing the momentum associated with the moving feeders (15). (See, U.S. patent application Ser. No. 07/418,005 (Schaefer, et al.) filed Oct. 6, 1989.)
To remove any excess moisture from the strand, the mat is continuously passed through an oven (17). The oven (17) is connected to a duct (20) and provided a heater (not shown) to heat a gas passed through it. The heated gas, preferably air heated to between 70° F. and 140° F., is passed through the hood (21) of the oven (17) which completely covers the width of the conveyor (13) and extends a sufficient distance along it to produce a residence time sufficient to reduce the moisture content of the mat to an acceptable level, usually between 1 to 0.5 percent.
After emerging from the oven (17), the loose mat (16) is usually conveyed from the surface of the conveyor (13) to a needling loom (18). The mat is advanced through the loom by a drive roller (22) which exerts a pulling force on it. The loom (18) has a needle board (23) to which are affixed a plurality of barbed needles (24) typically arranged in rows parallel to one another. The loom (18) is provided with a stripper plate (25) having holes drilled therein so that the needles (24) can be readily reciprocated therethrough. A bed plate (26) on which the mat (16) rests as it passes through the loom (18) is provided which also has a plurality of appropriately sized holes so that the reciprocating needles may pass through them. A tray (27) is also provided to catch any broken glass filaments. The needle board (23) reciprocates up and down as depicted by the arrows so as to push the needles partially through the loose mat (16), stripper (25) and bed plate (26) thereby causing the loose glass strands forming the mat to become entangled with one another.
Turning now to FIG. 4, the individual strands (6) are guided through a plurality of ceramic eyelets (not shown) so as to pass into each feeder (15) where they are projected downwardly from the feeder and deposited onto the surface of the moving chain conveyor (13). A plurality of strands may be provided to each individual feeder (15). The exact number of strands will be determined by the speed of the conveyor (13), number of feeders in operation, and the desired density or thickness of the finished mat.
In the preferred embodiment of the instant invention, adjustable stationary deflectors (19) positioned above the conveyor in such a manner that strands projected from each feeder impinge upon their surface and then fall toward the surface of the moving conveyor, where the strands assume a random orientation, are used.
The feeders (15) are caused to reciprocate or traverse back and forth across the conveyor (13) by means of a chain or cable (28) which is driven by a belt (29) connected to a reversible electric motor (30), preferably an indexing or brushless stepper motor described below. Each feeder (15) rides within a track (31) as it reciprocates across the moving conveyor (13). Typically, the speed of reciprocation of the feeder across the width of the conveyor is within the range of about 75 to 200 feet per minute and the feeder traverses in a direction generally perpendicular to the direction of motion of the conveyor surface (13). The pay-out rate of strand (6) from each feeder (15) is typically within the range of about 1000 to 5000 feet per minute.
Turning to FIG. 5, a detailed view of the strand feeder is illustrated. Strand (6) provided from previously made forming packages is guided by a plurality of ceramic eyelets (32) so as to pass along the outside surface of a flexible belt (33). The exact width of the belt may vary to accommodate the number of individual strands to be advanced by the feeder. The belt (33) and strand (6) are passed around a rotating cylindrical hub (34). The cylindrical hub (34) is driven by a variable speed electric motor (35). In the preferred embodiment, this motor is a three-phase A.C. induction motor.
As the strand (6) passes around the driven cylindrical hub (34) on the outside surface of the belt (33), the belt is caused to advance by friction generated between its inside surface and the hub (34). The belt (33) and strand (6) progress from the driven cylindrical hub (34) to a cylindrical cage (36) which is free-wheeling about a ball bearing (not shown). The cage (36) also has a plurality of pins or bars (37), protruding from its surface which run axially along its length. The strand (6) contacts these bars and is thus pinched between them and the outer surface of the belt (33). This produces the tractive force necessary to advance the strand (6) from the individual forming packages (9) which supply each feeder (15). Since the strand (6) contacts the cage (36) only at the bars (37), rather than along an entire continuous surface, the strand does not adhere to the bars (37) with the same tenacity as it would to a continuous surface. This helps prevent what are known as strand wraps which result in interruptions of the process. Since the strand (6) is carried between the outside surface of the belt (33) and the flight bars (37) while the belt is driven by the cylindrical hub (34) from its inside surface, the useful life of both surfaces of the belt is greatly increased.
DETAILED DESCRIPTION OF THE INVENTION
In the operation of the feeder, a brushless stepper motor (30) is used to cause the feeder (15) to reciprocate back and forth across the width of the conveyor as shown in FIG. 4. A flexible drive belt or chain (29) connects the output shaft of the stepper motor (30) with a first rotatable pulley or drum (38), about the circumference of which is wrapped a second flexible chain or, preferably, a stranded steel cable (28). The cable is of a length substantially twice the width of the conveyor. One end of the cable is firmly attached to one side of the frame of the feeder (39a) as shown in FIG. 5. The cable is then wrapped once or twice around the circumference of the driven drum (38), brought across the width of the conveyor and over a second free-turning idler drum (40) where the opposite end of the cable is attached to the other side of the feeder frame (39b). Thus, as the driven drum (38) shown in FIG. 4 is rotated clockwise by means of the stepper motor (30), the feeder will advance to the left. If stepper motor reverses its direction and turns the drum (38) counter-clockwise, the feeder will advance towards the right.
The brushless stepper motor (30) used to reciprocate the feeder must be capable of generating enough torque to overcome the momentum associated with the moving feeder (15) in order to reverse its direction quickly. The wire cable or chain (28) must also be capable of withstanding the stress associated with the reversal of the feeder apparatus.
A brushless stepper motor such as Model No. 112-FJ326 manufactured by Superior Electric Company of Bristol, Conn. was used in the preferred embodiment of the instant invention; however, any stepper motor capable of generating sufficient torque to overcome the momentum associated with the moving feeder apparatus may also be substituted.
Unlike a conventional A.C. or D.C. electric motor, the use of a stepper motor possesses several advantages. Among these are the fact that a stepper motor contains no brushes which must be periodically removed and cleaned; it also operates with greater speed, faster acceleration/deceleration rates, a better power to weight ratio and with greater reliability than conventional motors.
A brushless stepper motor is similar to an A.C. motor in that a moving magnetic field is produced in its stator windings while a permanent magnet is used for the rotor. As the stator windings are sequentially energized to produce a rotating magnetic field, the rotor turns and tries to keep up with it. A controller is used to switch the stator field by de-energizing one winding and energizing another. This is done by an amplified sequence of chopped D.C. current or pulses, also referred to as indexing commands, which are fed to the appropriate windings of the stepper motor in order to induce the rotation of the rotor by a fixed amount. The individual indexing commands or pulses are generated by an oscillator circuit. In the case of the motor used in the preferred embodiment, each pulse causes the rotor to advance by 1.8° and thus 200 such pulses will result in one complete revolution of the motor. Because of the particular dimensions of the belts, pulleys, etc. used in the instant invention, each revolution of the stepper motor causes the feeder to advance about two inches across the width of the conveyor. By first determining the desired width of the mat to be made and knowing the advance that each revolution of the stepper motor will cause the feeder to traverse along its track, as well as the number of indexing commands necessary to rotate the motor by one revolution, it is possible to control the motion of the feeder by determining the total number of indexing commands which must be sent to it in order to cause it to advance a specified distance. For example, if it were desired to form a mat six feet in width and it is known that the feeder advances two inches across the width of the conveyor per revolution of the motor, then it is necessary to send 7,200 index commands from the oscillator to the stepper motor in order to cause the feeder to advance six feet.
Another particularly attractive feature of stepper motors is their rapid acceleration and deceleration characteristics. For example, the motor used in the preferred embodiment can be accelerated from 105 to 3000 rpm in about 370 milliseconds. This rapid rise time, as well as the high torque output of the motor, makes since it possible to rapidly and smoothly reverse each of the moving feeders (15) without excessive jerking, vibration, or the need to rely upon mechanical devices such as shock absorbers or gas pistons.
The electrical circuit used to control the stepper motor is illustrated in FIG. 6 in block diagram form. An EPTAK 700 programmable controller (41) was used to determine the number of pulses necessary to advance the feeder a given distance across the width of the conveyor surface. The EPTAK 700 is a form of a programmable logic controller manufactured by the Eagle Signal Corporation. The actual distances that the feeder must traverse both left and right of an imaginary centerline are entered into the EPTAK through a plurality of thumb wheel switches which convert this information into binary coded decimal (BCD) form. The EPTAK internally calculates the total number of indexing commands or pulses necessary to advance the feeder back and forth in much the same manner as described above. This BCD information is then supplied to an indexer module (42) by means of a digital bus (43) and an internal oscillator within the indexer module generates the appropriate number of indexing commands to turn the stepper motor (30) in a clockwise or counter-clockwise direction. In the preferred embodiment, the indexer module is also capable of altering the frequency or repetition rate of the indexing commands so that the feeder may be accelerated or decelerated near the ends of each traverse cycle. In the instant invention, the indexer module used was a Slo-Syn Preset Indexer Module Type PIM153, manufactured by Superior Electric Company of Bristol, Conn. However, any such similar commercially available device for controlling the motion of a stepper motor may also be used.
The index commands or pulses generated by the internal oscillator of the indexer module are amplified to increase their voltage prior to being applied to the stator windings of the stepper motor. In the preferred embodiment, an amplifier, also known in the art as a translator, is a Slo-Syn TM600U translator (44), also manufactured by Superior Electric Company. However, because of the actual physical distances between the location indexer module and amplifier used in the instant invention, a buffer (45) was also used to isolate the pulse signals from any extraneous noise and reduce the output impedance of the indexer module to zero. A buffer chip, such as SN75451BP, manufactured by Motorola, was used in the instant invention to accomplish this although any such similar device may be substituted to achieve the same results.
Located above the conveyor on each feeder track (31) and midway across the width of the conveyor surface is an electromagnetic proximity switch or sensor (46). Each time the feeder (15) passes the proximity sensor causing it to close, a signal is transmitted to the EPTAK controller (14), which is interpreted as meaning that the feeder has completed one-half of a traverse cycle. In commercial applications where up to 12 feeders have been used to work in harmony with one another in order to produce mat having a uniform density distribution, the controller (41) may be programmed to recognize a preset sequence of signals from the centerline sensors associated with each individual feeder. Should the signal sequence detected by the controller (41) not be in agreement with the preprogrammed one, then the controller will interpret this as a malfunction in one of the feeders (15) and take corrective action. For example, if the controller were preprogrammed to expect a certain sequence of cross-over signals from feeders 1, 3 and 2 (in that order), and instead it only acknowledged the receipt of a signal from feeders 1 and 2, then the controller (41) would recognize that the receipt of a cross-over signal from feeder 2 where one was expected from feeder 3 instead meant that a potential problem may exist, such as a stalled motor or jammed feeder which caused the sequence to be other than the one expected. The controller would then signal the startup of an extra feeder located at a position further down the conveyor in order to make up for the amount of strand not deposited on it due to the failure of the third feeder. In commercial applications, up to 12 active feeders have been used simultaneously with as many as four additional make-up feeders.
In order to ensure the proper startup and sequencing of the feeders when many are used simultaneously with one another, a limit switch (47) located on one side of the track (31) is provided for each feeder. The purpose of the this limit switch (47) is to indicate a home position for the feeders (15) by sending a signal to the EPTAK controller (41). Once the controller senses that the feeders are in their home position as indicated by the status of each home limit switch (47), the controller (41) will cause the indexer module (42) to jog each feeder into an appropriate starting position prior to their beginning an automatic traverse of the conveyor. The controller (41) will then issue a command at the appropriate time to cause each feeder to begin independently traversing the width of the conveyor. The feeders are preferably started and timed in such a sequence such that strands thrown from immediately adjacent feeders do not overlap each other.
Three other electromagnetic proximity sensors are also used to indicate the relative position of each feeder during its traverse across the conveyor. These proximity sensors are used to control the rate at which strand (6) is advanced through the feeder from the supply source and onto the conveyor. Two sensors (49 and 50) are located at opposite ends of the track just short of the edges of the mat while the third (51) is located PG,21 near the centerline of the chain conveyor (13). In order to avoid non-uniform strand density near the mat edges, the use of these proximity sensors permits the feeder motor (35) and thus the throw rate of the strand to be slowed. This automatic reduction in the throw rate is accomplished by means of a second programmable logic controller (52) and an A.C. frequency inverter (53). The details of this arrangement can best be understood by consulting FIG. 7, which illustrates the circuit in block diagram form.
When an "off-on-off" signal sequence from the central sensor (51) is followed by an "off-on-off" signal from either one of the side sensors (49 or 50), the programmable logic controller (52) (hereinafter referred to as a "PLC") sends an output signal to the inverter to drop to a digitally adjustable preset frequency. This slows down the feed rate of the feeder motor (35), which is a conventional 480 volt electric A.C. three-phase induction motor. When an "off-on-off" signal from one of the side sensors is then immediately followed by an "off-on-off" signal from the same sensor, the PLC triggers the inverter to return to operating at its higher, original, digitally preset frequency. When this signal is then immediately followed by an "off-on-off" signal again from the central sensor (51), the PLC resets itself to again decrease the feed rate by lowering the inverter frequency upon receiving an "off-on-off" signal from the other side sensor. This control logic is repeated with every traverse of the feeder mechanism across the conveyor. In the instant invention, an Allen-Bradley SLC-100 programmable logic controller was used to control the inverter and to perform the appropriate switching functions according to the logic sequence just described. The PLC is a device programmable using conventional relay-ladder language. The inverter used was an Allen-Bradley 1333-AAB inverter capable of powering a one horse-power, 480 volt, three-phase A.C. induction motor over a frequency range of 0.5 to 70 Hz at a ratio of 7.6 v/Hz.
The use of the instant invention in the production of two different types of glass fiber mats will now be illustrated in detail.
EXAMPLE 1
In a typical application of the instant invention to produce a needled fiber glass continuous strand mat having uniform mechanical properties, glass strands are deposited onto the conveyor by a plurality of reciprocating strand feeders as illustrated in FIG. 8. Forming packages (9) of strand were held by means of a creel (54). Multiple strands (6) are passed through ceramic eyelet guides (55) and through a guide bar (56). The strands (6) are then passed to the strand feeders (15). Between the time of their leaving the creel (54) and entering the feeder (15), the strands may be wet with water or some other liquid antistatic agent to reduce the buildup of static electricity. Typically, the strands should have between about a 5 to 15 percent moisture content by weight. This helps to reduce any tendency of the strand to break and wrap itself around the belt-driven feeder. Generally, the use of an antistatic agent such as Triton X-100 which is a nonionic octylphenoxy polyethoxy ethanol surfactant is recommended when the strand is supplied from extremely dry forming packages which have been stored for several months.
An oven (17) is used to evaporate any excess moisture. Mat exiting the oven is then passed to a needling loom (18) where the strand is needled together in order to entangle it and impart sufficient mechanical integrity to allow the subsequent processing and handling of the finished mat.
In the fiber glass strand mat which was produced, randomly deposited strands of "T" fibers were supplied from T11.5 forming packages having about 400 fibers per strand with one pound containing about 1150 yards of strand. (The use of this designation is well known in the art and indicates that each individual glass fiber has a diameter on the order of 90 to 95 microns.)
The conveyor surface moved at a uniform rate of about 12 feet per minute and stationary deflectors (19) were also employed.
The feeders were reciprocated once every 6 seconds back and forth over a distance of about 90 inches at a mean velocity of about 160 to 165 feet per minute. The induction motor (35) contained in the feeder advanced the continuous strand supplied by the forming packages at a rate of between 1250 to 1300 feet per minute and preferably at about 1270 feet per minute. The terminal proximity sensors (49 and 50) used to trip each inverter were each located on the track about 9 inches just after the start, and about 9 inches just before the termination of, the 90-inch traverse stroke. Tripping the inverter caused the frequency and voltage supplied to the feeder motor (35) to drop so that the feed rate of the glass strand was reduced by 80 percent to between 250 to 260 feet per minute, preferably about 254 ft/min.
A total of 12 reciprocating feeders were used although only two were equipped with the variable speed induction motors (35) since it was found that this number of feeders provided sufficient compensation for the others so as to achieve mat of essentially uniform thickness. In order to produce a mat having a density of about 3 ounces per square foot, 6 ends of T11.5 strand were provided to each feeder so that about 1348 lb/hr of glass was deposited onto the surface of the conveyor. In order to produce a mat having a density of about 2 ounces per square foot, 4 ends of strand were provided so that only 905 lb/hr was deposited on the conveyor.
An oven (17) heated to about 105° F. and enclosing about a 20-foot length of the conveyor was used to evaporate excess moisture from the loosely formed mat. The mat was then stretched and passed to a needle loom (18) at a speed of about 16 ft/min. The needle loom (18) had a lineal needle density of about 114 needles per inch. The needles were reciprocated to yield a penetration density of about 140 penetrations per square inch to a depth of about 0.45 inches.
EXAMPLE 2
It has been found desirable in some applications to produce a mat having anisotropic or uni-directional material properties. A mat having directionally dependent mechanical properties such as tensile strength may be used to subsequently reinforce laminates which are used in the production of tire rims, automotive bumpers, or any structure in which it is desired that one direction have an enhanced tensile strength.
In the production of a mat having such directionally dependent mechanical properties, several thousand individual filaments in the form of strand were fed out onto the moving conveyor (13) and pulled along in the same direction of motion as the conveyor and in such a manner so as to lie substantially parallel to one another. As shown in FIG. 9, the strand (6) may be supplied from individual forming packages held by a creel (57) located at the front of the conveyor, however, the use of heavier strand in the form of roving packages is preferred. The strands (6) are passed through a plurality of ceramic eyelets (58) located on the creel (57) and brought through an eyeboard (59) also located at the front of the conveyor (13). The strands are then pulled through both the eyeboard and the tines of an accordion-like precision adjustable comb (60) also located just in front of the conveyor. The comb is used to provide a uniform number of strands per inch across the width of the mat and may also be adjusted to provide different lineal strand densities depending upon the particular mat being made.
Additional strands (6) are supplied to each reciprocating feeder (15) from some other source such as a fiber glass bushing or individual forming packages (9) as illustrated in FIG. 8. As these strands are advanced toward the surface of the conveyor (13) by the feeders (15), the weight of their build-up atop the first layer of strnds which are already moving in the direction of the conveyor tends to hold and maintain them in a substantially parallel orientation. It is preferred that the strands projected by the reciprocating feeders (15) be impinged upon the surface of a stationery deflector (19) just prior to their being deposited onto the conveyor. This results in a loosely bound mat having an upper layer of randomly oriented continuous strand and a bottom layer of substantially parallel strand. These loosely bound layers may then be passed through an oven (17) similar to that described in Example 1 to remove any excess moisture. Mat exiting the oven is then passed to a needling loom (18) where the upper and lower layers are needled together in order to entangle the strands and impart sufficient mechanical integrity to them to allow the subsequent processing and handling of the finished mat.
The mat may have a weight content of anywhere from 40 to 60 percent of aligned parallel strand fibers and anywhere from abuot 60 to 40 percent of randomly deposited continuous strand. In the fiber glass strand mat which was produced, about 55 percent of the mat contained aligned parallel strand and the remaining 45 percent was randomly deposited by the variable rate feeders (15) described herein. The parallel strand was supplied from direct-draw T2.50 roving packages having about 1600 "T" fibers per strand. (The use of this designation is well known in the art and indicates that each individual glass fiber has a diameter on the order of 90 to 95 microns and that one pound of this particular roving contains about 250 yards of strand.) The precision adjustable comb (60) was set to provide anywhere from about 7 to 8 strands per inch across about a 100-inch width of the conveyor surface. The randomly deposited strand was also a "T" fiber supplied from T11.5 forming packages having about 400 fibers per strand with one pound containing about 1150 yards of strand.
The conveyor surface moved at a uniform rate of about 12 feet per minute and stationary deflectors (19) were also employed.
The feeders were reciprocated once every 6 seconds back and forth over a distance of about 90 inches with a mean velocity of about 160 to 165 feet per minute. The induction motor (35) carried by the feeder advanced the continuous strand supplied from the forming packages at a rate of between 1250 to 1300 feet per minute and preferably at about 1270 feet per minute. The terminal proximity sensors (49 and 50) used to trip each inverter were each located on the track about 9 inches just after the start, and about 9 inches just before the termination of, the 90-inch traverse stroke. Tripping the inverter caused the frequency and voltage supplied to the feeder motor (35) to drop so that the feed rate of the glass strand was reduced by 80 percent to between 250 to 260 feet per minute, preferably about 254 feet per minute.
A total of 12 reciprocating feeders were used although only two were equipped with the variable speed induction motors (35) since it was found that this number of feeders provided sufficient compensation for the others so as to achieve mat of essentially uniform thickness. In order to produce a mat having a density of bout 3 ounces per square foot, 3 ends of T11.5 strand were provided to each feeder so that about 607 lbs/hr of glass was deposited onto the surface of the conveyor.
An oven (17) heated to about 105° F. and enclosing about a 20-foot length of the conveyor was used to evaporate excess moisture from the loosely formed mat. The mat was then passed to a needle loom (18) at a speed of about 12.1 ft/min. The needle loom (18) had a lineal needle density of about 114 needles per inch. The needles were reciprocated to yield a penetration density of about 140 penetrations per square inch to a depth of about 0.45 inches.
Test samples cut from the needled mat described herein had about a 3 to 4 percent improvement in the coefficient of variation of mat density by reducing it from 7 to about 4 percent or lower.
Although, the above examples have relied upon the needling of the strands in order to impart mechanical integrity to the loose mat structure, it is a common practice well known in the art to deposit powdered resin particles onto the mat and then subsequently heat it in order to bond the strands and resin together rather than rely upon mechanical bonding produced by needling. In order to impregnate a continuous glass strand mat, it is usually sufficient to deposit the resin by sprinkling it directly upon the mat by means of a trough and an agitator, also well known in the art, just prior to the point where the mat enters the oven and is heated to a temperature sufficient to melt the resin. The mat and resin are then solidified by means of chill rollers, also well known in the art. The use of a resin such as ATLAC-300, manufactured by ICI-USA, Inc. is particularly well suited for this application. It is contemplated that the methods described above used to control the strand feeders may also be used to produce resin-bonded mats having similarly reduced density and thickness variations.
While the mats described in the disclosure and proceeding examples have all been illustrated as being made from fiber glass strand, it is not intended that the methods of the instant invention is necessarily limited thereto. For example, the same methods described herein may be used in the production of mats made from any other natural or synthetic fibers as well as glass. Strands composed of nylon, polyester, and the like, may also be substituted or mixed with one another as well as with packages carrying glass fibers.
Also, while the use of certain specific electrical components has been described, it is not intended that they be necessarily limiting since all are commercially available devices and other similar devices may be readily substituted to achieve substantially the same results. For example, the use of electro-magnetic proximity sensors to detect the moving feeders and trip the inverters also contemplates the use of magnetic proximity sensors, photo-electric sensors, electro-optical sensors, and mechanical limit switches. Also the use of a frequency inverter to control the speed of an electric motor is not strictly limited to the control of a three-phase induction motor since any two or three-phase electric motor capable of varying its speed in response to a frequency inverter is contemplated as well.
Therefore, while this invention has been described with respect to certain specific embodiments and components and illustrated with its application to the production of certain products, it is not intended to be so limited thereby except insofar as set forth in our accompanying claims. | This invention relates to improvements in making mats of continuous fiber strand using controlled reciprocating strand feeders. More particularly, the invention relates to improvements in making continuous fiber glass strand mats having more uniform density by electronically controlling both the rate of reciprocation and the rate at which strands are deposited onto the surface of a moving conveyor while also reducing the vibration associated with the feeders. Still more particularly, the invention relates to improvements in the production of two continuous fiber glass strand mats, one having uniform mechanical properties while the other possesses directionally dependent ones.
In the preferred embodiment, brushless stepper or indexing motors are used to reverse the direction of reciprocating strand feeders quickly and smoothly so as to minimize their vibration. Also provided are variable speed electric motors in conjunction with a programmable logic controller and frequency inverter to adjust the rate at which strand is deposited by the feeders onto the moving conveyor.
It is shown, by way of example, that these improvements result in increased uniformity of both mat density and thickness. | 3 |
TECHNICAL FIELD
[0001] The disclosed inventive concept relates generally to the riveting of a workpiece. More particularly, the disclosed inventive concept relates to a system for riveting from opposite sides of a workpiece.
BACKGROUND OF THE INVENTION
[0002] The automobile manufacturing industry is constantly faced with new challenges in a wide array of areas including vehicle safety, reliability, durability and cost. Perhaps the greatest challenge faced by the automobile industry today is the need to improve fuel mileage to both decrease carbon emissions and increase fuel economy for both environmental and cost reasons, all without compromising safety, power or durability. In 2011, new fuel economy requirements were imposed that establish a US vehicle fleet average of 54.5 miles per gallon by 2025. As the industry moves to that target year fuel annual economy requirements will be ramped up for different-sized vehicles.
[0003] Efforts have been made to increase fuel economy for vehicles. These efforts can be divided into two approaches: the “supply” side and the “demand” side.
[0004] On the supply side attention is drawn to improving energy conversion efficiency through use of, for example, electric or hybrid-electric drive trains. In addition, new vehicle drive trains, including smaller engines and more efficient transmission having multiple gears and transfer cases, are being developed and employed. Other technologies, including start-stop and engine cylinder deactivation strategies, are also proving effective at decreasing fuel consumption. Improved transmissions with multiple gears are also important elements to increased fuel consumption efficiencies.
[0005] On the demand side weight reduction is key, though other aspects, such as improved aerodynamics and drag reduction, are also important. Conventional vehicles, particularly trucks, rely on steel components. For over 100 years the material of choice for most vehicles is steel. Today steel makes up about 60% of the average car by weight.
[0006] Despite the improvement in steel composition the weight of steel regardless of type remains significant. It is also possible to reduce vehicle weight when steel is used by reducing component thickness. However, at a certain point it is no longer practical to reduce steel thickness regardless of the steel grade used. The use of high strength steel or advanced, high strength steel does not improve the realization that there are limits to how much vehicle weight can be reduced by steel thickness reduction without compromising vehicle performance.
[0007] Thus as the automotive industry continues to focus on light weighting vehicles to meet customer expectations on fuel economy and CAFE requirements, interest in alternative materials including aluminum intensive vehicle applications has increased. This is because vehicle weight reduction is most directly accomplished through substituting lighter materials for currently used steel parts. However, a limited variety of materials are available as a substitute for automotive steel. One such material is carbon fiber which is both lightweight and strong.
[0008] While carbon fiber offers certain performance advantages, replacement of the steel body-in-white with carbon fiber is expensive and brings with it a relatively slow production process.
[0009] Accordingly, much attention is drawn to the use of aluminum which is about ⅓ the weight of steel. Aluminum is not a new material for automotive use and has been used as a material for castings for over 100 years. The use of aluminum not only provides weight reduction but also results in good crash performance. Research has shown that in collisions aluminum can perform as well as conventional steel and demonstrates the ability to absorb twice the crash energy per pound of mild steel, having good buckling and energy absorption characteristics.
[0010] In body-in-white structures, joining methods have traditionally relied on resistance-spot welding (e.g., in steel structures). In the case of aluminum intensive vehicles and other mixed metal joining applications, self-piercing rivet (SPR) technology prevails. One advantage of self-piercing rivet technology is that it is a high production volume assembly process. Further, it is compatible with an adhesive, where both methods can be used in conjunction.
[0011] The challenge often faced when using the self-piercing rivet to fasten together multiple layers is that the substrate material must have sufficient thickness to enable a satisfactory mechanical interlock between the rivet and the bottom layer while simultaneously avoiding a rivet break-through out of the lower layer. Production downtime due to rivet break-through can be exacerbated for applications which contain adhesive as the glue can contaminate the rivet equipment. Additionally, material stack-ups that are three layers (3T) and greater can be especially challenging to rivet as the bottom layer thickness relative to the total stack is too small to provide adequate interlock.
[0012] In cases where riveting a 3T application is not possible due to no interlock, the situation may be remedied occasionally by using a rivet having a greater length. In some instances, however, a solution is not found prior to causing break-through when increasing the length of the rivet. Conversely, when break-through occurs there are applications where using a shorter rivet will result in no interlock, resulting in a joint having no mechanical strength.
[0013] As in so many areas of vehicle technology there is always room for improvement related to the mechanical fastening of the materials through self-pierce riveting.
SUMMARY OF THE INVENTION
[0014] The disclosed inventive concept overcomes the problems associated with known systems for riveting a material stack-up of at least three layers. The system includes a material stack-up comprising an upper layer, an intermediate layer and a lower layer, a first rivet attaching the upper layer and the intermediate layer, and a second rivet attaching the lower layer and the intermediate layer. The first rivet attaches the upper layer to the intermediate layer through the upper layer and the second rivet attaches the lower layer to the intermediate layer through the lower layer.
[0015] The first and second rivets are alternatingly positioned in a spaced apart relationship. The rivets are selected from the group consisting of self-piercing rivets, blind rivets and solid rivets. When self-piercing rivets are used, the first rivet includes rivet tail and the second rivet includes rivet tail. The rivets are alternatingly positioned such that the tail of the first rivet are adjacent the tail of the second rivet when the layers of material are attached by the rivets.
[0016] Optionally, an adhesive may be included between the upper layer and the intermediate layer. Alternatively or additionally, an adhesive may also be included between the intermediate layer and the lower layer.
[0017] By alternating rivets according to the disclosed inventive concept, only two layers are joined from each side, thereby avoiding difficulties such as “break-through” of the bottom layer where adhesive is exposed and can contaminate the rivet die and associated equipment and the “no interlock” result between layers where the rivet has not splayed sufficiently to lock the layers together. Accordingly, the disclosed inventive concept enables greater application of rivet joining, particularly self-piercing rivet joining, and more particularly in difficult stacks, such as where thin layers are on the bottom of the sheet metal stack-up.
[0018] The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention wherein:
[0020] FIG. 1A is a schematic illustration of the first step of a self-piercing rivet process according to the prior art in which the blankholder and the punch are in position above the rivet prior to pressure being applied to the punch;
[0021] FIG. 1B is a schematic illustration of the second step of the self-piercing rivet process according to the prior art in which initial pressure has been applied to the punch;
[0022] FIG. 1C is a schematic illustration of the third step of the self-piercing rivet process according to the prior art in which the rivet has pierced the upper layer and is interlocked into the lower layer;
[0023] FIG. 1D is a schematic illustration of the fourth step of the self-piercing rivet process according to the prior art in which the rivet process has been completed and the punch and blankholder have been removed;
[0024] FIG. 2A is a cross-section view of a self-piercing rivet joint illustrating a break-through on the lower layer according to the prior art;
[0025] FIG. 2B is a plan view of the lower layer where the self-piercing rivet joint has broken through according to the prior art;
[0026] FIG. 3A is a cross-section view of a self-piercing rivet joint illustrating a rivet that has not splayed sufficiently to lock layers of sheet-metal together according to the prior art;
[0027] FIG. 3B is a cross-section view of a self-piercing rivet joint illustrating a rivet that has splayed sufficiently to lock layers of sheet-metal together according to the prior art; and
[0028] FIG. 4 is a cross-section view of a rivet arrangement according to the disclosed inventive concept in which the rivets are inserted in alternating directions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] In the following figures, the same reference numerals will be used to refer to the same components. In the following description, various operating parameters and components are described for different constructed embodiments. These specific parameters and components are included as examples and are not meant to be limiting.
[0030] The disclosed inventive concept may find use in any number of applications where plural layers of the same or dissimilar materials are being attached. Accordingly, the disclosed inventive concept may be used in the production of automotive vehicles and trucks.
[0031] The use of self-piercing rivets in the assembly of plural components is a known technique as illustrated in FIGS. 1A through 1D . These figures schematically show steps involved in the self-piercing rivet process. As the rivet is inserted into the stack. the material deforms into the die and the resultant form is called a “button.”
[0032] As illustrated in FIG. 1A , the first step of a self-piercing rivet process according to the prior art is illustrated. A first layer is shown in position over a second layer 12 . A rivet 14 is illustrated in position over the first layer 10 . A punch 16 and a blankholder 18 are illustrated in position with the rivet 14 prior to pressure being applied to the punch 16 . A die 20 is in position beneath the second layer 12 .
[0033] In FIG. 1B , the second step of the self-piercing rivet process according to the prior art is illustrated. In this step, initial pressure has been applied to the punch 16 and the rivet 14 is shown beginning to deform the first layer 10 and the second layer 12 .
[0034] In FIG. 1C , the third step of the self-piercing rivet process according to the prior art is illustrated. In this step, the punch 16 has been fully inserted through the blankholder 18 such that the rivet 14 pierced the first layer 10 and forms the second layer 12 .
[0035] In FIG. 1D , the fourth step of the self-piercing rivet process according to the prior art is illustrated. In this step, the rivet 14 is shown fully inserted through the first layer 10 and a button is formed in the second layer 12 . The punch 16 and the blankholder 18 have been moved out of contact with the first layer 10 .
[0036] While a valuable mechanical fastener in many automotive and other assembly applications, use of the self-piercing rivet is occasionally challenged by the fact that the substrate material must have sufficient thickness to enable mechanical interlock between the rivet and the bottom layer while simultaneously avoiding a condition known in the industry as “rivet break-through.” This condition is illustrated in FIGS. 2A and 2B .
[0037] Referring to FIG. 2A , a cross-section view of a self-piercing rivet joint is shown and is generally illustrated as 30 . The self-piercing rivet joint 30 includes a material stack-up 32 and a self-piercing rivet 34 . The material stack-up 32 includes a first or upper layer 36 , a second or middle layer 38 , and a third or lower layer 40 . Thus the second or middle layer 38 is sandwiched between the first or upper layer 36 and the third or lower layer 40 . An upper adhesive layer 42 is formed between the first or upper layer 36 and the second or middle layer 38 . A lower adhesive layer 44 is formed between the second or middle layer 38 and the third or lower layer 40 .
[0038] When riveted, the rivet joint 30 may experience “break-through” where some of the lower adhesive layer 44 is exposed at a breach 46 formed through the third or lower layer 40 . The breach 46 is shown more fully in FIG. 2B which is a plan view of the third or lower layer 40 . In the event that the breach 46 is formed, a portion of the adhesive of the lower adhesive layer 44 is exposed and may contaminate the self-piercing rivet die and installation equipment, thus exacerbating production downtime due to rivet break-through in material stack-ups where adhesive is used as glue between layers.
[0039] Self-piercing rivets suffer from shortcomings in other applications as well. Referring to FIG. 3A , a cross-section view of a self-piercing rivet joint, generally illustrated as 50 , is shown. The self-piercing rivet joint 50 includes a material stack-up 52 and a self-piercing rivet 54 . The material stack-up 52 includes a first or upper layer 56 , a second or middle layer 58 , and a third or lower layer 60 . Thus the second or middle layer 58 is sandwiched between the first or upper layer 56 and the third or lower layer 60 . The self-piercing rivet 54 includes a pair of spaced-apart and opposed tails 62 and 62 ′.
[0040] When riveted, the rivet joint 50 may suffer from a “no interlock” condition in which tails 62 and 62 ′ do not splay sufficiently as illustrated. Under such a circumstance, the self-piercing rivet 54 fails to lock together the first or upper layer 56 , the second or middle layer 58 , and the third or lower layer 60 .
[0041] The failed results of the rivet joint 50 may be compared with an acceptable interlock illustrated in FIG. 3B in which a cross-section view of a self-piercing rivet joint, generally illustrated as 70 , is shown. The self-piercing rivet joint 70 includes a material stack-up 72 and a self-piercing rivet 74 . The material stack-up 52 includes a first or upper layer 76 and a second or middle layer 78 . The self-piercing rivet 74 includes a pair of spaced-apart and opposed tails 80 and 80 . As illustrated, because the material stack-up 72 includes only two layers as opposed to three layers of the material stack-up 52 of FIG. 3A , the self-piercing rivet 74 has less material to pierce and thus the tails 80 and 80 ′ can more easily splay to their proper position in which an acceptable interlock can be achieved as shown in FIG. 3B . Accordingly, material stack-ups which are three layers (3T) and greater can be especially challenging to rivet as the bottom layer thickness relative to the total stack is too small to provide adequate interlock.
[0042] The disclosed inventive concept combines the relative effectiveness of riveting two layers of material with the advantage of using rivets to attach material stack-ups having three or more layers while preventing lower layer “break-through” and consequent adhesive exposure and while also preventing a “no interlock” condition that is often found when three layers of material are riveted using a single rivet.
[0043] Particularly, and referring to FIG. 4 , a cross-section view of a self-piercing rivet joint according to the disclosed inventive concept is shown and is generally illustrated as 90 . The self-piercing rivet joint 90 includes a material stack-up 92 and self-piercing rivets 94 , 94 ′, 94 ″ and 94 ′″ that are alternatingly positioned on the self-piercing rivet joint 90 such that the self-piercing rivets 94 and 94 ″ enter the self-piercing rivet joint 90 through one side while the self-piercing rivets 94 ′ and 94 ′″ enter the self-piercing rivet joint 90 through the opposite side. Any number of self-piercing rivets may thus be used provided that some degree of alternating directions between one side and the other is employed. Furthermore, while self-piercing rivets are illustrated, it is to be understood that other types of rivets, such as blind rivets and solid rivets, may be employed as well,
[0044] The material stack-up 92 includes a first or upper layer 96 , a second or middle layer 98 , and a third or lower layer 100 . Thus the second or middle layer 98 is sandwiched between the first or upper layer 96 and the third layer or lower layer 100 . However, it is to be understood that more than three layers of material may be included in the material stack-up. The first or upper layer 96 , the second or middle layer 98 and the third or lower layer 10 may be any of a variety of materials including metals such as steel or, more particularly, carbon steel grade (DP800) or carbon-fiber composites. An adhesive may be applied between said first or upper layer 96 and said second or middle layer 98 prior to assembly. In addition or alternatively, an adhesive may be applied between said third or lower layer 100 and said second or middle layer 98 prior to assembly,
[0045] Thus arranged, each of rivets 94 , 94 ′, 94 ″ and 94 ′″ join only two layers. Specifically, and as illustrated, the self-piercing rivets 94 and 94 ″ join the first or upper layer 96 and the second or middle layer 98 while the self-piercing rivets 94 and 94 ′″ join the third or lower layer 100 and the second or middle layer 98 . When all of the rivets 94 , 94 , 94 ″ and 94 ′″ are considered in combination, the resulting monolith represented as the self-piercing rivet joint 90 is robustly joined. The disclosed inventive concept may be extended to material stack-ups having more than three layers.
[0046] The disclosed inventive concept enables greater application of rivet joining. particularly self-piercing rivet joining, and more particularly in difficult stacks, such as where thin layers are on the bottom of the sheet metal stack-up. The disclosed inventive concept also avoids the weakening of such joints via other solutions such as “scalloping,” or separating the application into two two-layer stack-ups, thus potentially eliminating adhesive applicability, saving both material and labor costs.
[0047] For at least the above reasons the disclosed invention as set forth above overcomes the challenges faced by known methods for riveting multiple layers of material by rivets inserted with alternating directions. However, one skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following cairns. | A system for attaching layers of a material stack-up of at least three layers together using rivets alternatingly place on each side of the stack-up is disclosed. The system includes a material stack-up comprising an upper layer, an intermediate layer and a lower layer, a first rivet attaching the upper layer and the intermediate layer, and a second rivet attaching the lower layer and the intermediate layer. The first rivet attaches the upper layer to the intermediate layer through the upper layer and the second rivet attaches the lower layer to the intermediate layer through the lower layer. The first and second rivets are alternatingly positioned in a spaced apart relationship. The rivets are selected from the group consisting of self-piercing rivets, blind rivets and solid rivets. When self-piercing rivets are used, the first rivet includes rivet tail and the second rivet includes rivet tail. | 5 |
RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 08/613,951, filed Mar. 11, 1996, entitled "Method and System for Providing Data Files That Are Partitioned by Delivery Time and Data Type," by inventor Galen C. Hunt, now abandoned. Priority to the filing date of that application is hereby claimed.
TECHNICAL FIELD
The present invention relates generally to computer systems and, more particularly, to file formats used in computer systems.
BACKGROUND OF THE INVENTION
Servers must often provide audio and video data to a client computer. In most conventional systems, the audio data and the video data are stored as separate files and are transferred from the server to the client via commands. The file formats for the audio data file and the video data file do not indicate the delivery time for the data and do not explicitly set forth synchronization between the audio data and video data. Generally, a user must identify how much audio data is to be transferred per a frame of video data. The commands are then used to synchronize and complete the transfer of data from the server to the client.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, a method is practiced on a computer system that has a server, a client and one or more output devices. A sequence of data is partitioned in a file at the server into units of delivery time. The data is delivered in the sequence to the client according to the units of delivery time. The data is then rendered at the output device independently of when the data was delivered.
In accordance with another aspect of the present invention, a file is stored on a storage device in a computer system. The file is logically organized into channels such that each channel holds data of a given data type. Each channel is logically partitioned into corresponding units of delivery time such that for each unit of delivery time each channel holds any data that is to be delivered during that unit of delivery time. The data from the file is transferred to the destination by concurrently transferring data from each of the channels on a per delivery time basis. In particular, for each unit of delivery time, any data in each of the channels for the unit of delivery time is concurrently delivered to the destination.
In accordance with a further aspect of the present invention, video data is stored in a file on a storage device such that the video data is logically partitioned at the units of delivery time. Audio data to accompany the video data is also stored in the file. The audio data is similarly logically partitioned into units of delivery time. The audio data is transferred with the video data to a destination on a logical unit of time basis such that for each successive unit of delivery time any of the audio data and the video data for that unit of delivery time is transferred.
In accordance with yet another aspect of the present invention, a file is stored on a storage device of a server in a distributed system. The file is logically partitioned into channels wherein each channel holds data of a given data type. Each channel is logically partitioned into corresponding units of delivery time such that for each unit of delivery time each channel holds any data that is to be delivered during the unit of delivery time. Channel handlers are provided on the client to process data in a channel of a specific data type. The data from the file at the server is transferred to the client by concurrently transferring data from each of the channels in a per delivery time basis such that for each unit of delivery time any data in each of the channels for the unit of delivery time was concurrently delivered to the client. The transferred data is a process of the client using the channel handlers.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will be described below relative to the following figures.
FIG. 1 is a block diagram of a distributed system that is suitable for practicing the preferred embodiment to the present invention.
FIG. 2 depicts the logical organization of an example synchronized presentation format file in accordance with the preferred embodiment to the present invention.
FIG. 3 illustrates the organization of a synchronized presentation format file.
FIG. 4 illustrates the field in an index entry of a synchronized presentation format file.
FIG. 5 is a flow chart illustrating the high level steps that are performed in transferring a synchronized presentation format file from a server to a client.
FIG. 6 is a flow chart illustrating how data is transferred in blocks for a synchronized presentation format file.
FIG. 7 is a flow chart illustrating the steps that are performed to determine label width for a synchronized presentation format file.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention provides a synchronized presentation format for data files in which logical data channels and units of delivery time are explicit in the file format. The delivery time of data in the file is independent of when the data is rendered so as to enable the available bandwidth of the delivery mechanism to be better exploited. The synchronized presentation format allows the storage of multiple data channels in a file wherein each data channel constitutes a single complete unit of deliverable media. For example, a device independent bitmap may be stored in a first channel of a file and a WAVE file may be stored in a second channel of a file. Each of the data channels is divisible into logical units of delivery time (denoted as "ticks"). Data fragments from all channels marked for the same tick are delivered and processed within the tick. This organization facilitates the determination of the requisite bandwidth required for the data held in the synchronized presentation format file, and explicitly sets forth the delivery sequence and synchronization. This file organization greatly simplifies the transfer of related multiple media to a client by explicitly setting forth delivery times and by relieving the server of synchronization responsibilities.
FIG. 1 is a block diagram illustrating a suitable computer system 10 for practicing the preferred embodiment of the present invention. The computer system 10 includes a server 12 and a client 14, which may be implemented as separate computers. The server 12 includes a storage 16 that holds a synchronized presentation format file 18. The server 12 is coupled to the client 14 via network connection 21. The client 14 also includes a storage 22 that holds one or more channel handlers 24. As will be described in more detail below, each channel handler is responsible for processing data of a given channel data type. Those skilled in the art will appreciate that the computer system configuration shown in FIG. 1 is intended to be merely illustrative, and that the present invention may be practiced with other computer system configurations.
The logical organization of the synchronized presentation format file of the preferred embodiment of the present invention may be illustrated by way of example. FIG. 2 shows an example of the logical organization of such a file. The file shown in FIG. 2 is divisible into five channels. Each channel has a unique label that identifies the data type held within the channel and a numerical identifier. Thus, the "WAVE channel 1" is the first data channel that holds a WAVE sequence of audio data. The "WAVE channel 2" channel holds a second sequence of WAVE data. The "DIB channel 1" and "DIB channel 2" channels hold device independent bitmaps. "INFO channel 1" holds copyright information. The preferred embodiment of the present invention supports a number of different channel types. These channel types include a WAVE channel type for holding WAVE audio data, a DIB channel type for holding device independent bitmaps of still frame video, an INFO channel type for holding copyright information, a file channel type for holding files that are to be downloaded, and an execution channel type for holding information that tells a client to take a file that has been downloaded and to run the file. Those skilled in the art will appreciate that these channel types are intended to be merely illustrative and not limiting of the present invention.
As can be seen in FIG. 2, each of the data channels is divisible into ticks. As was mentioned above, a tick is a logical unit of delivery time. For example, a tick may correspond with one second or with another predetermined fixed duration of time. In the preferred embodiment of the present invention, all ticks have a like duration, and the duration of a tick is fixed per file. The ticks are organized sequentially such that tick 0 precedes tick 1, which in turn precedes tick 2, etc. The X's shown in FIG. 2 indicate that the data channel has data to be delivered during the corresponding tick. For example, during tick 0, "WAVE channel 1," "INFO channel 1" and "WAVE channel 2" all have data to be delivered. "DIB channel 1" and "DIB channel 2," however, do not have data to deliver during tick 0.
FIG. 3 shows the actual file organization of a synchronized presentation format file 18. Each synchronized presentation format file 18 includes an initial index fragment 26 that is followed by one or more data fragments 28. The index fragment is composed of a number of index entries. Each index entry describes either an index fragment or a data fragment. The index entries are especially useful to the channel handlers in processing transferred data. As shown in FIG. 4, each index entry 30 includes five fields. The channel label field 32 is the sequence of ASCII characters that describe the type of data in the channel. For example, the channel labels may include "WAVE," "INFO," "DIB," "FILE," "EXEC" and "spf".
The index entry 30 also includes a render field 34 that specifies whether data in the associated fragment is to be rendered or, alternatively, is to be cached for future use. The delivery priority field 36 specifies the numerical priority of the associated fragment. A normal priority for data fragments is zero (which is the lowest priority). In contrast, the normal priority for an index priority is the highest priority, because the index fragment must be delivered before the subsequent data fragments may be processed.
The channel number field 38 specifies the number of the channel as an unsigned integer. Channels of like data types are numbered in sequential order beginning with 1. The fragment data size field 40 holds a value that specifies the size in bytes of the associated fragment. The render field 34, delivery priority field 36, channel number 38 and fragment data size field 40 are packed together into a single unsigned integer, known as the value label 41, that has the same number of bytes as the channel label field 32.
In order to gain a better appreciation of the synchronized presentation format, it is helpful to consider an example. The following is an example of a portion of a file in the synchronized presentation format:
______________________________________File Position Description______________________________________0 Index Fragment Fragment Label Render Priority Channel # Data Size0 spf\0 0 Maximum 1 1608 WAVE 0 0 1 1816 INFO 1 0 1 5424 tick 0 0 0 132 WAVE 1 0 1 102440 DIB 0 0 1 1348 tick 0 0 0 256 WAVE 1 0 1 76864 DIB 1 0 1 51272 tick 0 0 0 380 WAVE 1 0 1 102496 DIB 0 0 2 512104 tick 0 0 0 4112 WAVE 1 0 1 768120 DIB 1 0 2 512128 18 bytes of WAVE 1 unrendered data for tick 0.146 54 bytes of INFO 1 data for tick 0.200 1024 bytes of WAVE 1 data for tick 1.1224 13 bytes of DIB 1 data for tick 11337 768 bytes of WAVE 1 data for tick 2.______________________________________
In the example given above, the first four bytes of the synchronized presentation format file, like all synchronized presentation format files, contain the values "s", "p", "f", "\0", respectively. Assuming a label width of four bytes, the next four bytes contain the value label for the index fragment, "spf\0". The index fragment entry is immediately followed by index entries for all the data channels in the synchronized presentation file format. In the example above, each index entry is eight bytes in length. Thus, in the example given above, the index fragment entry is followed by an index entry for WAVE channel 1. The next index entry is an index entry for INFO channel 1. The two index entries that follow the index fragment entry are for initialization fragments for the channels. These entries are, in turn, followed by index entries for respective ticks. As is illustrated above, a separate index entry is provided for each tick. The tick index entry is followed by an index entry for each channel that has data to be delivered during the associated tick.
The index entries are followed sequentially by the data fragments that are labeled by the index entries. Thus, the initialization data fragments are the first data fragments that follow the index entries.
The synchronized presentation format for files is especially helpful when transferring data from a server to a client across a network. FIG. 5 shows a flowchart that illustrates the high level steps that are performed in such a transfer. Initially, the data is passed from the server 12 to the client 14 over the network connection 21 (step 42 in FIG. 5). The client computer then passes the data based on data type to the appropriate channel handlers 24 (step 44 in FIG. 5). The channel handlers process the data to render it or cache the data (step 46). For example, a WAVE channel handler may output the data to an audio output device, such as a loudspeaker. On the other hand, a DIB channel handler may display the device independent bitmap on a video display.
When a synchronized presentation format file is delivered across the network connection 21, it is delivered in blocks where each block holds data for a fixed number of ticks that is equal to the block delivery time. For example, a block may hold the data for two ticks. FIG. 6 is a flowchart that illustrates the steps that are performed to transmit the data from the server to the client (see step 42 in FIG. 5). Initially, the data for the block that is to be transmitted is packaged into a block (step 48 in FIG. 6). The packaging may occur on a per demand basis or, alternatively, may be completed before any blocks are transmitted. The block is then transmitted over the network connection (step 50). The system checks whether there are any more blocks to be transmitted (step 52). If there are additional, blocks to be transferred, the next block is packaged and transmitted (see steps 48 and 50 in FIG. 6).
An example is helpful to illustrate how the data is packaged into blocks. An example of the packaging of blocks with a block play time of two ticks for the previously given synchronized presentation format file is set forth below.
______________________________________Block 0: (Initialization Tick)File Position Description______________________________________0 Index Fragment Fragment Label Render Priority Channel # Data Size0 spf\0 0 Maximum 1 248 WAVE 0 0 1 1816 INFO 1 0 1 5424 18 bytes WAVE 1 unrendered data for tick 0.42 54 bytes of INFO 1 data for tick 0.96 End of block.______________________________________
______________________________________Block 1:File Position Description______________________________________0 Index Fragment Fragment Label Render Priority Channel # Data Size0 spf\0 0 Maximum 1 568 tick 0 0 0 116 WAVE 1 0 1 102424 DIB 0 0 1 1332 tick 0 0 0 240 WAVE 1 0 1 76848 DIB 1 0 1 51256 1024 bytes of WAVE 1 rendered data for tick 1.1080 13 bytes of DIB 1 unrendered data for tick 1.1093 768 bytes of WAVE 1 rendered data for tick 2.1861 512 bytes of DIB 1 rendered data for tick 2.2373 End of block.______________________________________
______________________________________Block 2:File Position Description______________________________________0 Index Fragment Fragment Label Render Priority Channel # Data Size0 spf\0 0 Maximum 1 568 tick 0 0 0 316 WAVE 1 0 1 102424 DIB 0 0 2 51232 tick 0 0 0 440 WAVE 1 0 1 76848 DIB 1 0 2 51256 1024 bytes of WAVE 1 rendered data for tick 3.1080 512 bytes of DIB 2 unrendered data for tick 3.1592 768 bytes of WAVE 1 rendered data for tick 4.2360 512 bytes of DIB 2 rendered data for tick 4.2872 End of block.______________________________________
As can be seen from the above example, each block includes an index fragment that includes index entries for the index fragment and data fragments in the block. These blocks are followed by the data fragments. Each block is terminated by an end of block indicator. The blocks are transmitted in sequence until all of the blocks have been transmitted.
When the client computer 14 receives data for a synchronized presentation format file, it is not certain how many bytes are contained in the channel label. The size of the channel label may vary. In order to determine the label width, the client performs the steps shown on the flowchart of FIG. 7. Initially, the client assumes that the label width is four bytes (the smallest possible label width). In FIG. 7, the variable N is set to have a value of 4 in step 54. The variable N specifies the current guess in bytes of the label width. If the label width is four bytes, the four bytes that follow the first four bytes (i.e., bytes N+1 through 2N) will be non-zero. Thus, in step 56, it is determined whether these bytes are zero. If the bytes are not zero, the label width is four bytes (step 60). However, if these bytes are zero, the estimate of label width is doubled by multiplying the value of N (step 58 in FIG. 7). It is then checked whether the N+1 through 2N bytes are zero or not (step 56). When N is eight, the ninth through sixteenth bytes are examined to determine if they are zero. If these bytes are non-zero, the label width is eight bytes (step 60). This process is repeated until the non-zero bytes are located.
While the present invention has been described with reference to a preferred embodiment thereof, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the intended scope of the invention as defined in the appended claims. | A file is logically partitioned into data channels where each data channels holds a sequence of data of a particular data type. The data channels are logically partitioned into delivery times. The format of the file explicitly sets forth the synchronization between the data channels and the delivery times of data held within the channels. The file format is especially well adapted for use in a distributed environment in which the file is to be transferred from a server to a client. Channel handlers are provided at the client to process respective data channels in the file. The channel handlers are data type specific in that they are constructed to process data of an associated data type. The data in the file may be rendered independently of the delivery time of the data. | 7 |
FIELD OF THE INVENTION
This invention concerns a device to apply cord thread or ribbons onto fabrics, simple or padded, in a quilting machine.
The invention also concerns a quilting machine, advantageously but not exclusively a multi-needle machine, equipped with this device.
The invention also concerns a method to apply a ribbon or cord thread onto fabrics, simple or padded, both continuously and also alternated with segments of simple sewing, in a quilting machine.
The invention is applied in the textile field and refers to the automatic application, by means of stitches suitable to achieve a desired pattern or ornamental design, of a cord thread, ribbon or trimming onto simple, multi-layer or padded fabrics fed continuously from rolls.
The invention is applied preferentially, but not exclusively, to multi-needle quilting machines, of the type which makes both knotted stitches and chain stitches.
The invention is characterized by the fact that it includes at least one pressure plate, co-operating with the needle-bearing bar, which supports a plurality of devices equipped with at least a rotary element with alternating or simple motion, able to direct the ribbons or trimming into a position which is always in front of the needle with respect to the direction of sewing, or to interweave around the needle and fix cord thread, trimming or ribbons, fed from appropriate reels, so that the cord thread, ribbons or trimmings are fixed onto the fabric by means of stitches, either continuously or alternated with simple stitches according to a defined working program.
BACKGROUND OF THE INVENTION
In the field of embroidering machines the state of the art includes the use of devices to automatically apply ribbons or cord thread onto fabrics cut into pieces.
These devices serve to make particular types of embossed embroidery; they work on pieces of a limited length, particularly on pieces worked on the tambour frame, in a discontinuous work pattern which gives limited productivity.
Moreover, the ornamental designs made by these devices are isolated, considerably distant from each other and discontinuous.
When these devices are used the embroidery machines have a very low working speed, in the region of 120 stitches a minute at most.
State of the art devices of this type, as they are used at present, are therefore not suitable for use on electronically controlled machines which continuously work fabric supplied from a roll, with speeds of at least 450 stitches a minute and which can reach up to 600+700 stitches a minute.
Such conventional devices are used only to apply large section cord thread or ribbons or chenille or embroidery thread (therefore unable to pass through the eye of a needle), on a base fabric.
In such devices the ribbons or embroidery threads are not made to pass through the fabric and are not fixed thereon by means of stitches made by needles which perforate them; they are fixed to the fabric by means of the stitches of a thin thread which passes above them and is anchored to the fabric once on one side and once on the opposite side of the embroidery threads (see for example FIG. 1 in CH-A-563.486).
In such devices, for this purpose, suitable wheels are provided equipped with an alternate rotary movement, generally produced by rectilinear racks; each wheel is provided with a central hole through which the needle with the fixing thread passes and an eccentric hole of a suitable diameter, through which passes the cord thread or the embroidery thread which has to be attached on the fabric.
While the needles carrying the fixing thread perform a normal stitching action, the alternating rotations of the wheels cause the cord threads or embroidery threads to be positioned alternately on one side and the other of the needles, and therefore cause the stitches made thereby to pass alternately from one side to the other above the cord threads or embroidery threads, thus fixing them to the fabric.
Among these conventional devices, the one described in CH-A-563.486 describes a device able to modify the position of the eccentric hole though which the embroidery thread passes, according to the orders to move given by an automatic embroidery machine commanded by a perforated belt, according to the rotation of the direction of stitching backwards-forwards-left-right, so that the rotation in one direction and the other of the wheels has its center, on each occasion, in the correlated main direction of stitching backwards-forwards-left-right.
In document FR-A-467.481 there are wheels with pins on the outer circumference, commanded by a perforated flexible belt into the holes of which the pins enter, instead of the rectilinear rack.
However, these documents refer to embroidery machines, not to multi-needle quilting machines.
Quilting machines, as we have said, have a working speed at least in the range of 450 stitches per minute, compared with a maximum speed in embroidery machines of about 120 stitches per minute.
Moreover, whereas in embroidery machines the fabric is cut into pieces, attached manually onto appropriate frames before the embroidery operation, and removed always manually when the work is finished, in quilting machines the fabric or the sandwich of material which is to be quilted is unwound continuously from rolls, with a huge saving in time and effort for the workers.
In embroidery machines the needles work in a horizontal direction, whereas in quilting machines they work in a substantially vertical direction.
In quilting machines there is at least a pressure plate on which the wheels through which the thread passes are mounted, with the respective command organs, whereas in embroidery machines there is no pressure plate whatsoever.
The final products obtained from quilting machines are essentially quilted bed-covers which can also be embroidered, whereas in embroidery machines the final products consist of any type of embroidery or decoration on single-layer fabrics of a decorative type.
Conventional devices, moreover, do not give the possibility of carrying out step by step, with the position of the wheels, the desired program of embroidery; therefore they do not allow to achieve designs of absolute precision with the cord threads, ribbons or additional threads; nor do they allow to alternate on command segments where the cord thread or ribbon is applied with segments of simple stitching to achieve particular ornamental patterns according to a pre-determined sewing program.
In conventional devices, moreover, it is not always possible, at every step of the program, to direct the hole through which the embroidery thread passes perfectly in front of the needle according to the direction of sewing, with discrepancies of a fraction of a degree; nor is it possible to exclude the alternate rotation of the wheels.
This does not allow these conventional devices to sew exactly in the center, whatever may be the direction of sewing, ribbons, tapes and flat trimmings and to attach them on the basic fabric, nor to alternate segments where ribbon or cord thread is applied with segments of simple stitching, thus limiting the applications and possibilities.
The Applicant has devised and embodied this invention in order to overcome this shortcoming of the state of the art, which has never provided or hypothesised applications of this type on multi-needle quilting machines, given the difficulty of using embroidery techniques previously employed only on machines which were operationally and technologically completely different, and to obtain further advantages as shown hereafter.
SUMMARY OF THE INVENTION
The invention is set forth and characterized in the respective main claims, while the dependent claims describe other characteristics of the main embodiment.
The purpose of the invention is to provide a device, and the relative method, to apply cord thread, ribbons or trimming, suitable to be applied onto a quilting machine, particularly a multi-needle machine, in order to work fabrics fed continuously from a roll with a speed in the region of 450 stitches a minute and which can reach 600 to 700 stitches a minute.
A further purpose is to achieve a quilting machine including the device described above, suitable to continuously work fabrics, simple and padded, obtaining any ornamental design whatsoever of the stitches by means of electronic control.
A quilting machine on which the device according to the invention is applied comprises at least a needle-bearing bar, on which a plurality of needles are mounted in alignment.
The needle-bearing bar is equipped with alternate ascending/descending motion to take every needle to co-operate with a mating lower sewing element, consisting of a shuttle, a rotary crochet or a movable hook also equipped with alternating motion mating with the movement of the needle-bearing bar.
The co-operation between the needles, each of which is fed with its own thread called needle thread, and the lower sewing elements causes stitches to be made on the fabric, fed continuously from rolls and located between the sewing organs.
The quilting machine according to the invention also comprises at least a pressure plate equipped with movement mating with the movement of the needle-bearing bars.
According to the invention, a plurality of devices, able to apply ribbon or cord thread onto the fabric according to a desired ornamental pattern, are mounted on the pressure plate in correspondence with pre-selected specific needles or specific groups of needles.
Each of these devices consists of a fixed assembly part, solid with the relative pressure plate, and a movable part suitable to be made to rotate by drive means according to a desired, variable angle.
The drive means may be commanded mechanically, electrically, pneumatically, hydraulically, magnetically or otherwise.
The movable part is equipped with at least a hole or eyelet through which, according to the individual case, the ribbon or the cord thread to be applied pass, supplied by suitable feeding reels. In a preferential embodiment of the invention, the eyelet is eccentric with respect to the axis of rotation of the movable part.
In a preferential embodiment, the movable part consists of a detachable insert, equipped with at least a hole and at least an eyelet which are eccentric with respect to the hole through which the needle passes.
According to whether the application concerns ribbon or cord thread, the insert may be detached and re-attached directed in a different manner with respect to the fixed assembly part, so that it is possible to cover both options with a single element.
According to a variant, the insert can be replaced according to the diameter of the ribbon and/or the cord thread to be applied.
According to a further variant, the insert has a plurality of holes and/or eyelets in order to cover a range of diameters of ribbons and/or cord threads with a single, directable element.
During normal sewing operations, made with alternate movements of the needle-bearing bar and the mating pressure plate, the moving part of the application device is made to rotate alternately around its own axis of rotation by alternately activating the respective drive means.
The rotation of the movable part, carried out in co-ordination with the vertical, alternating movement of the sewing needles, may take place with angles of different amplitude with reference to the direction of sewing.
In the case of ribbons being applied, which are sewn directly onto the fabric by the needle thread, the angles of rotation determined by the command program of the machine are such as to keep the eyelet through which the ribbon passes in a position which is always in front of the needle according to the direction of sewing of the various steps of the pattern to be achieved.
In this way the stitching is always made perfectly in the center of the ribbon.
In the case of cord threads or yarns of the Lurex® type being applied, the invention not only directs the position of the eyelet, or hole, to a position which is always in front of the needle according to the direction of sewing; it is also possible, with this invention, to impart to the movable part alternate, symmetrical rotations in the two directions with respect to this basic position, with angles which are programmed in such a manner that the cord thread or Lurex® yarn, which pass through the eyelet or hole, wind alternately in a spiral around the relative sewing needle.
In this case, the cord thread is not sewn directly by the needle thread but winds around said thread and is attached to the fabric between two consecutive sewing stitches.
The angles of alternate rotation of the movable part may be of variable amplitude, for example in the range of about 80°, to ensure that the cord thread winds around the sewing needle.
The rotation of the movable part also confers a torsion which binds the needle thread and the cord thread together.
The cord thread wound around the needle is sewn in this way, with every sewing cycle, by the needle thread and is fixed to the fabric fed continuously to the machine.
A variant of the invention provides that, during the application of the ribbon or cord thread, the rotation of the movable part may be interrupted on command at pre-determined points of the pattern being formed, in a position such that it does not create interference with the sewing needle, and subsequently re-started at other points. In this way, we achieve segments where the ribbon or cord thread is applied in alternation with segments of simple sewing with the needle thread, in order to achieve ornamental designs characterized by such alternation.
During the sewing cycle, the fabric is subjected to controlled displacements—to-and-fro, right-left—by the command unit of the sewing machine according to the pattern to be made.
By properly programming the movement of the fabric, any type whatsoever of ornamental pattern can be made, from the simplest, with a linear development, to the most complex, substantially comparable to an embroidery.
With the device according to the invention it is possible to apply ribbon, cord thread or similar onto continuously fed fabric, according to the pattern made by the machine, with a much higher speed and with much thicker and more continuous patterns compared with those made in any other type of machine known in the state of the art, with an obvious advantage in terms of productivity and variety of application.
The machine which adopts the device according to the invention can be used as a normal quilting machine, for example a multi-needle quilting machine, by excluding the device; or as an embroidery machine to apply ribbon, cord thread or similar onto simple or padded fabrics fed continuously; or again as a machine which simultaneously achieves quilts and also the application of the ribbon, cord thread or similar, thus obtaining mixed patterns with innovative and original characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other characteristics of the invention will become clear from the following description, given as a non-restrictive example, of some preferential forms of embodiment of the invention with reference to the attached drawings wherein:
FIG. 1 is a schematic view of an electronically commanded multi-needle quilting machine of the type suitable to comprise a device to apply a ribbon or cord thread according to the invention;
FIG. 2 is a schematic view of four devices to apply a ribbon or cord thread according to the invention suitable to co-operate with two relative needle-bearing bars of the quilting machine shown in FIG. 1 ;
FIG. 3 shows the device in FIG. 2 during the working step;
FIGS. 4 a and 4 b show a plane and a raised view of a possible embodiment of the device according to the invention;
FIGS. 5 a – 5 g show some examples of patterns which can be obtained with the machine according to the invention;
FIG. 6 shows in a detail a preferential embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an electronically controlled multi-needle quilting machine 10 of a general type which is substantially known. The quilting machine 10 comprises, as its essential parts, an inlet assembly 10 a , a sewing assembly 10 b and an outlet assembly 10 c.
The inlet assembly 10 a is used to feed the textile material 11 which has to be worked. The inlet assembly 10 a is managed and controlled by software and is therefore able to move the textile material 11 in any direction whatsoever, to-and-fro or right-left, in order to achieve any type of pattern, even extremely complex ones.
The sewing assembly 10 b comprises upper sewing organs 12 and lower sewing organs 15 of a conventional type.
The upper sewing organs 12 consist, in this case, of two parallel needle-bearing bars 13 , respectively 13 a and 13 b , on which respective aligned needles 14 are assembled, each co-operating with a respective thread 16 , called the needle thread, fed from respective reels 116 arranged in the upper part of the machine 10 .
The needle-bearing bar 13 includes needle-positioning seatings 38 associated with means 39 to clamp the needles 14 into position. For a better understanding of the invention, FIG. 2 shows only a few needles 14 , as it is obvious that according to the type of stitch to be done all the seatings 38 can house a relative needle 14 .
The needle-bearing bars 13 a and 13 b are equipped with alternate ascending-descending motion to take the needles 14 into co-operation with the respective lower sewing organs 15 , consisting of shuttles, rotary crochets or alternately moving hooks, in a conventional manner.
The co-operation between the sewing organs 14 and 15 causes a plurality of stitches 18 to be made simultaneously on the textile material 11 ; according to the movement imparted to the textile material 11 , the stitches 18 achieve desired patterns to obtain the quilted textile product which is collected by the outlet assembly 10 c.
During the sewing cycle the needle-bearing bars 13 co-operate with a pressure plate 19 , also equipped with an alternate ascending-descending motion correlated to the movement of the needle-bearing bars 13 .
The function of the pressure plate 19 , in this case, is to descend and compress the padded textile materials 11 as the stitch is being formed, in order to improve the quality of the stitches 18 ; it re-ascends immediately afterwards to allow the material 11 to move.
There are a plurality of holes 20 made on the pressure plate 19 and arranged in correspondence with the needles 14 in order to allow them to pass when the needle-bearing bar 13 is in the descending step.
In this case, a plurality of devices 24 are mounted on the pressure plate 19 in suitable reciprocal positions and are suitable to apply ribbon 31 a , cord thread 31 or similar onto the textile material 11 subjected to sewing, the ribbon 31 a or cord thread 31 being fed from their own reels 40 installed on the machine 10 , and controlled by suitable thread-brakes, which are not shown here, able to ensure that they are constantly under tension.
Each device 24 consists of a stationary assembly flange 25 , made solid with the pressure plate 19 by means of screws 36 , inside which an annular bearing 26 is mounted on which a ring 27 is suitable to rotate.
The ring 27 is solidly connected with a toothed pulley 28 associated with drive means.
In this case, the drive means consist of one or more brushless motors 21 , managed by the electronic command program of the quilting machine 10 by means of suitable drives.
In this case, the brushless motor 21 is fixed in a central position to the cross-piece of the quilting machine 10 by means of screws 35 and is equipped with a telescopic grooved shaft 42 which makes a rotary toothed pulley 43 rotate, with bearings, on a support 44 attached to the pressure plate 19 , of which the pulley 43 follows the vertical, alternating, ascending-descending movements.
Two toothed belts 45 are engaged on the pulley 43 ; in turn, one towards the right and one towards the left in co-operation with appropriate return and tensioning rollers 46 , the toothed belts 45 command two other toothed pulleys 143 , rotating on bearings on relative supports 144 attached to the pressure plate 19 .
On each of the pulleys 143 two other toothed belts 145 are engaged, which command, one towards the right and one towards the left, two other toothed pulleys rotating with bearings on relative supports attached to the pressure plate 19 and so on.
A toothed pulley 22 is attached to the lower part of each toothed pulley 43 , 143 , . . . , rotating with bearings on the relative supports 44 , 144 , . . . attached to the pressure plate 19 .
The toothed pulley 22 is able to draw a belt 23 into rotation; the belt 23 , in this case, winds around the respective toothed pulleys 28 of two application devices 24 .
There are return and tensioning rollers 33 in co-operation with the belt 23 .
A replaceable insert 27 a is inserted into the rotary ring 27 and has a substantially central through hole 29 , which allows the relative needle 14 to pass when the bar 13 is lowered to make the stitch. An eccentric eyelet 30 a and an eccentric hole 30 are respectively made on the insert 27 a ; selectively and according to the specific application, these have the function of allowing to pass respectively the ribbon 31 a or the cord thread 31 which have to be sewn or attached by the thread 16 onto the textile material 11 .
In practice, according to the type of application, the insert 27 a will be assembled on the relative ring 27 in such a manner as to selectively locate either the eyelet 30 a or the hole 30 in the working position, according to whether the process concerns a ribbon 31 a or a cord thread 31 . According to the variation in the diameters of said elements 31 , 31 a , the insert 27 a can be replaced by another, analogous insert but equipped with holes or eyelets of different diameters.
It also comes within the field and scope of the invention to provide the insert 27 a with a plurality of holes 30 or eyelets 30 a of different diameter according to the diameter of the element 31 , 31 a which is to be applied.
During the stitching cycle of the ribbon 31 a , the brushless motor 21 is made to rotate and, by means of the toothed pulleys 43 , 143 , the toothed belts 45 , 145 , the toothed pulleys 22 , the belts 23 , the toothed pulleys 28 and the relative rings 27 and inserts 27 a , said eyelets 30 a in which the ribbons 31 a pass are directed, with every sewing stitch, into a position which is always in front of the needle with respect to the direction of stitching.
In this way, the stitching is always perfectly in the center of the ribbon 31 a.
During the stitching cycle of the cord thread 31 , the brushless motor 21 is made to rotate alternately, making the toothed pulleys 43 , 143 , the toothed belts 45 , 145 , and the toothed pulleys 22 rotate.
The alternate motion of rotation is transmitted through the belt 23 to the toothed pulleys 28 and from them to the relative rings 27 and inserts 27 a.
The alternate rotation of the rings 27 and the relative inserts 27 a causes the cord thread 31 to be wound in a spiral, passing through the eccentric hole 30 , around the relative needle 14 and its thread 16 , through an angle determined by the angle of rotation of the rings 27 .
The amplitude of the angle of alternate rotation of the rings 27 is variable and, in this case, is equal to about 80° with a base position at every stitch always in front of the needle 14 with respect to the direction of sewing, to ensure that the cord thread 31 winds around the relative needle 14 .
In this condition the cord thread 31 is then drawn downwards by the descending movement of the needle 14 , and sewn onto the textile material 11 together with the needle thread 16 , according to the ornamental pattern or design programmed on the machine 10 .
FIGS. 5 a – 5 g show some possible patterns which can be made with the method and device according to the invention.
FIGS. 5 a and 5 b refer to simple designs, wherein the needle thread 16 is applied respectively in a zigzag and linearly, and the cord thread 31 is positioned alternately on one side and the other thereof for each stitch 37 .
FIGS. 5 c and 5 d refer to more complex designs, to create particular ornamental patterns substantially similar to embroidery.
As the cord thread 31 is wound in a spiral around the needle 14 and its thread 16 , this causes a torsion which binds the cord thread 31 and the thread 16 closely together.
FIGS. 5 e and 5 f refer to simple and complex designs wherein the ribbon 31 a is applied with a stitch by the thread 16 onto the textile material 11 .
FIG. 5 g refers to particular, elaborate designs which can be obtained with the invention wherein, according to the specific ornamentation to be carried out, it is possible to alternate segments wherein the cord thread 31 or the ribbon 31 a is applied with segments wherein this application is momentarily interrupted to perform simple stitching with sewing thread 16 .
This allows, for example, to achieve designs with outer perimeters formed by additional cord thread 31 and inner portions filled with simple stitches made by the sewing thread 16 ( FIG. 5 g ).
During the steps of simple sewing with thread 16 , the stop position of the eccentric holes or eyelets 30 a and 30 of the inserts 27 a is programmed so that the cord thread 31 or the ribbon 31 a are always in a position opposite to the direction of sewing, so that they are not sewn or accidentally attached to the fabric.
Moreover, the thread-brakes which co-operate with the respective cord threads or ribbons are activated to impart thereto a constant tension; this prevents them from floating freely during the steps of normal sewing, so that they are not accidentally sewn or attached by the sewing thread 16 .
FIG. 4 b is a bird's eye view of a pressure plate 19 on which two devices as shown in FIG. 2 are assembled.
It is obvious that, according to an evolution of the invention, these devices can be displaced on the plate 19 into the desired positions in relation to the pattern to be made.
FIG. 4 b shows an embodiment wherein a single brushless motor 21 simultaneously commands four devices 24 thanks to the configuration of the belt 23 and the three return and tensioning rollers 33 .
It is also obvious that the devices 24 can be driven, instead of by the brushless motor 21 , by any suitable drive means—pneumatic, mechanical, hydraulic or otherwise.
For example, a rack may be provided, driven by a pinion provided for the purpose, suitable to co-operate with the respective toothed pulleys 28 of all the devices 24 arranged in a row, there being included another independently driven rack for the devices 24 located in another row.
Or, there may be a pneumatic actuator for pairs or fours of devices 24 . Again, the movement may be imparted by alternately activating an electromagnetic device, a hydraulic device or otherwise.
Moreover, even though this description refers to two needle-bearing bars 13 a and 13 b , the invention can also be applied in the case of three or more needle-bearing bars.
The machine 10 described above therefore allows to continuously work textile material 11 supplied from rolls at an extremely high speed, up to 600÷700 stitches a minute and more, obtaining the desired ornamental patterns, from the simplest to the most complex.
Moreover, the machine 10 is extremely versatile in that it allows to make simple quilting by excluding the devices 24 , to simply apply the ribbon 31 a or cord thread 31 if only the needles 14 , in correspondence with which the devices 24 are present, are used, applications of ribbon 31 a or cord thread 31 alternated with simple stitching by alternating on command the rotation and arrest of the devices 24 , and to make combined products if both the needles 14 co-operating with the devices 24 , and also those not co-operating with them, are used.
The machine 10 according to the invention is also easy to prepare since, to support and position the devices 24 , it uses elements such as the pressure plate 19 which are already included in a normal quilting machine. | A device for applying an embroidery material onto a textile fabric including a device for feeding the textile material; an upper sewing organ having a needle bearing bar and a plurality of needles; a lower sewing organ selected from the group consisting of shuttles, rotary crochets and moving hooks cooperating with the upper organ. At least one pressure plate for compressing the material and having embroidery devices thereon and a drive for providing rotational motion to the embroidery devices, wherein the drive device includes a hole for each needle to pass through and a second hole for the embroidery material to pass through, and wherein the rotational motion is in a single direction so as to direct the second hole in a position that is in front of the needle to obtain stitches on the textile fabric and to fix the embroidery material. | 3 |
TECHNICAL FIELD
The present invention is related a safety device for a vehicle comprising front and side facing brake lights which alert a crossing motorist or pedestrian that the oncoming vehicle is applying the brakes.
BACKGROUND
The use of lights to indicate the intentions, or actions, of the operator in a motor vehicle are well know. Brake lights and turn signals are now common place on vehicles. Of particular interest for the present invention are brake lights.
There is little argument that the utilization of brake lights severely limits the number of accidents. Particularly, brake lights on the rear of a vehicle alert following operators that the vehicle brake is engaged. The operator of the following vehicle can then also apply the brake thereby reducing the likelihood that the vehicles will collide.
A large number of collisions between vehicles, or between a vehicle and pedestrian, occur at intersecting roads. It is not uncommon for a vehicle to travel through a stop signal while either totally ignoring the signal or attempting to get through the intersection prior to cars entering the intersection from a different direction. This is especially a problem when other cars at the intersection assume that the cars approaching the intersection are applying the brakes. Unfortunately, the application of the brakes is not easily determined from the front of a vehicle.
Yet another problem is associated with pedestrians attempting to cross at an intersection. It is common practice to await the appearance of a red signal light for approaching vehicles prior to crossing the intersection. If, however, a vehicle does not stop the pedestrian may step into the street and be struck by the vehicle crossing through the intersection.
There are other examples where a person, or vehicle, may incorrectly interpret the actions of an approaching vehicle and stray into the path of the approaching vehicle only to be struck by the vehicle. If these types of collisions could be eliminated, or even mitigated, the number of injuries and fatalities occurring by vehicle traffic would diminish.
One approach to solving this problem is the use of a forward facing brake, or indicator, light. Descriptions of this approach are many.
U.S. Pat. No. 1,553,959 to Pirkey describes a stop signal which may be readily visible to drivers in the front and back of the vehicle. It is apparent to even a casual observer that the utilization of front brake lights has not been considered useful in the approximately 80 years since the issuance of the Pirkey patent.
U.S. Pat. No. 3,364,284 to Dankert describes a speed controlled signal system which indicates the drivers actions. Not only does the system of Dankert provide information regarding a stop but also the change in speed of vehicle. The complexity of the lighting system has never reached widespread acceptance.
U.S. Pat. No. 5,788,358, issued to Davis, describes a forward facing brake light which is attachable to a rear view mirror. Among other problems the reflection of the light may be a distraction to the driver. Furthermore, in many vehicles the upper portion of the windshield glass is tinted to act as a sun shield. This sun shield would limit the ability of a person forward of the vehicle to easily distinguish the light. If the light is lower than the mirror it would obscure the visibility of the driver which has obvious bad consequences.
U.S. Pat. No. 5,798,691 describes a brake light system for the front of a vehicle which utilizes LED's. The device is easily attached to the grill of a vehicle.
U.S. Pat. No. 5,966,073 describes a combination brake/turn signal light. The complicated utilization of various color schemes has not reached wide spread acceptance.
The prior art all considers the same general solution to the problem of alerting the intentions of the driver to observers forward of the car. In general, the prior art adapts a light, like the rear brake light, to the front of the vehicle in some fashion. This application has never materialized into widely accepted practice.
While not restricted to any theory, applicants submit that part of the lack of utilization of forward facing brake lights is that the lights, contrary to the wide held belief in the art, could create additional hazards. For example, when a vehicle approaches an intersection the light may transition from green to amber to red. It is not uncommon for an operator to initially attempt to stop, or slow down, by applying the brakes momentarily thereby illuminating any brake indicator lights on the vehicle. After applying the brakes it is not uncommon for the operator to realize that the distance required for stopping exceeds the distance to the intersection and the operator then lifts the brake and coast, or accelerates, through the intersection. If an observer, pedestrian or other vehicle operator, sees the brake light illuminate they assume that the vehicle will stop and proceed into the intersection. The operator of the approaching vehicle may then enter the intersection after the aborted stop and collide with the pedestrian or other vehicle. In this unfortunate, but realistic, scenario the intentions of the operator provide a false indication thereby increasing the likelihood of a collision due to the aborted stop.
There has been a long felt desire in the art for an apparatus which can alert an observer of the intentions of a vehicle operator to stop the vehicle. There has been an even greater desire to provide such an indication without providing false indications which may be worse, in many situations, than no indication. The present invention provides a novel approach to the problems described herein at a reasonable cost.
SUMMARY
It is an object of the present invention to provide a safety feature for a vehicle which is capable of decreasing the number of collisions between vehicles and between vehicles and pedestrians.
It is another object of the present invention to provide a forward facing brake light which decreases the occurrence of false indications of operator intentions.
A particular feature of the present invention is the incorporation of a delay period between the time the brake mechanism is engaged and the time the front light is illuminated.
Another particular feature of the present invention is the simplicity and the ability to utilize the invention in existing vehicles or to incorporate the invention in cars during manufacture.
A particular advantage is the economical implementation of the present invention.
These and other objects, features and advantages will be realized from the description wherein provided is an accessory brake light system for a vehicle comprising a secondary brake light attached to a front of said vehicle. A power source is provided for supplying power to a primary brake light. The primary brake light is attached to the rear of the vehicle. A switch connects the power to the primary brake light when the brake is engaged by an operator which causes the primary brake light to illuminate. A delay mechanism is provided which is capable of determining a delay period after the brake is engaged and the power is connected to the secondary brake light after te delay period thereby illuminating the secondary brake light.
Yet another embodiment is provided in an accessory brake light system for a vehicle. The vehicle comprises a front, a rear, a brake engagement switch and a brake light attached to the rear which illuminates when the brake engagement switch is activated. The system comprises a secondary brake light attachable to the front of the vehicle. A delay mechanism capable of determining a delay period is provided. When the brake engagement switch is activated the delay period passes prior to the secondary brake light illuminating.
Yet another embodiment is provided in an accessory for attachment to a vehicle. The vehicle comprises an electrical circuit comprising a brake engagement switch and a power source. The accessory comprises a couple attachable to the circuit. A secondary circuit is connecting to the couple and to a brake light wherein the brake light is attachable to the front of the vehicle. A delay mechanism is provided which is capable of delaying illumination of the secondary brake light for a delay period from when the brake engagement switch is activated.
DESCRIPTION OF DRAWINGS
FIG. 1 is a front perspective view of an embodiment of the present invention as incorporated on a vehicle
FIG. 2 is a schematic representation of a circuit diagram of the present invention.
FIG. 3 is a schematic representation of another circuit diagram of the present invention.
FIG. 4 is a perspective exploded view of a preferred light assembly of the present invention.
DETAILED DESCRIPTION
The present invention provides a forward brake light on a car which has a built in delay period between activation of the brake and illumination of the light. The delay period decreases the likelihood of a false indication that a vehicle operator is intending to stop the vehicle.
The invention is described with reference to the various figures wherein similar elements are numbered accordingly. The figures represent preferred embodiments and do not limit the scope of the invention.
An embodiment of the present invention is provide in FIG. 1 . In FIG. 1, a vehicle, generally represented at 1 , comprises a front, 2 , rear, 3 , and sides, 4 , as commonly defined for vehicles. The transition between the sides, 4 , and front, 2 , may be rounded to decrease wind resistance or for aesthetics. Attached to the front, 2 , of the vehicle, 1 , is at least one forward facing head lamp, 5 , which has the primary function of illuminating the road during night driving. In the present invention at least one secondary brake light, 6 , is provided which is observable from in front of the vehicle. In an alternate embodiment at least one tertiary brake light, 7 , is provided. The tertiary brake light, 7 , is towards the side of the vehicle and is therefore visible from in front of the vehicle, such as in the path of travel, or from the side of the vehicle, such as out of the path of the vehicle but forward of the front wheel, 8 , or rear wheel, 9 .
The secondary brake light, 6 , and optional tertiary brake light, 7 , are characterized by their illumination which occurs at least 0.1 seconds after the brake mechanism is engaged by the driver. In a more preferred embodiment the secondary, and optional tertiary brake light, illuminate at least 0.2 seconds after the brake mechanism is engaged by the driver. It is most preferred that the secondary and optional tertiary brake light illuminate at least 0.5 seconds after the brake mechanism is engaged by the driver. It would be apparent from the description herein that the delay period between engagement of the brake pedal and illumination of the secondary or optional tertiary brake light is sufficiently long to insure that the brake mechanism is not simply tapped but is engaged in a manner to stop the vehicle. If, for example, the vehicle operator initially engages the brake pedal but then decides to proceed the secondary brake light would preferably not illuminate thereby avoiding the inaccurate indication that the operator intends to stop the vehicle. It would also be apparent that the delay period must be sufficiently short that the light is illuminated prior to stopping. It is most preferred that the delay period between engaging the brake mechanism and illumination of the secondary and optional tertiary brake light be no more than 1.5 seconds. More preferably, the delay period is no more than 1 second and most preferably the delay period is no more than 0.75 seconds. In a particularly preferred embodiment the delay period between activation of the brake mechanism and illumination is between 0.5 and 0.75 seconds. The delay period may also be variable and a function of the speed of the vehicle. For example, if the vehicle is traveling faster the delay period may be longer to insure that the vehicle operator does not abort the stop in close proximity to the intersection. It is also contemplated that the secondary brake light have a delay period which differs from the delay period of the tertiary brake lights. For example, the secondary brake light may illuminate after a first delay period and the tertiary brake lights may illuminate after a second delay period. It is most preferable that the second delay period be longer than the first delay period.
The secondary brake light is preferably located on the front of the vehicle centrally located between the forward facing head lamps. If multiple secondary brake lights are employed they may be symmetrically placed about the center line of the vehicle. It is preferred that the secondary brake light be either below or above the line defined by the center of the headlights to avoid visual interference between the light emitted by the forward facing head lamps and the secondary brake light. In one embodiment the secondary brake light is below the line defined by the center of the headlights. This is preferred since the light emitted by the secondary brake light would be less distracting to the vehicle operator. In another embodiment the secondary brake light is above the line defined by the center of the headlights. In this embodiment it is most preferred that the secondary brake light have a light shield to decrease the amount of light which is emitted towards the vehicle which could distract the vehicle operator.
A representative circuit diagram of the present invention is provided in FIG. 2 . In FIG. 2, the brake switch, 20 , is closed when the brake mechanism is activated, or engage by the operator, and open when the brake mechanism is not activated as common in the art. The operational details of the brake switch are not limited herein and may include any of the commonly employed switches employed to illuminate a vehicle brake light. It is most preferred that the brake switch be between the various components and the power source, 21 , with the exception of an optional but preferred fuse, 22 , which may be on either side of the switch, and before or after any component. A delay, 23 , delays the time between the closing of the brake switch, 20 , and the illumination of the light, 24 , as described previously. An optional, but preferred, delay controller, 25 , allows the delay period to be altered or programmed if desired. The circuit is typically grounded at 26 as known in the art of circuit design.
An alternate circuit diagram is provided in FIG. 3 . In FIG. 3, the existing rear brake light circuit may be employed. Existing rear brake light circuits comprise a brake switch, 20 , which closes the circuit between the power source, 21 , and ground, 26 , thereby illuminating the light of the brake light assembly, 29 . A couple, 27 , attached to the wires, 28 , allows the power to the brake light assembly to be similarly sent to a secondary circuit comprising an optional fuse, 22 , delay, 23 , optionally with an associated delay controller, 25 , and light, 24 . The embodiment illustrated in FIG. 3 is preferred due to the ease with which existing vehicles could be retrofitted with the inventive braking light system. Many vehicles currently employ a factory installed couple just prior to the brake light assembly. In a particularly preferred embodiment the couple is a t-connection wherein the factory installed couple connects with the couple associated with the inventive device. T-couples are well known to provide a junction in a wiring circuit. The factory installed couple is disengaged and re-engaged into each side of a t-connection couple of the present. A particularly preferred embodiment has a molded t-connection component with wires integral thereto. The wires would then be run along the frame, or other suitable location of the vehicle, to a location suitable for mounting the light, 24 .
A preferred light assembly is illustrated in perspective exploded view FIG. 4 . In FIG. 4, the light assembly, generally represented at 30 , comprises a base, 31 . The base, 31 , receives a bulb, 32 , in a bulb void, 33 . The bulb, 32 , reversible engages with a socket, 34 . The bulb and socket may utilize mating threads, post and slots, or tension based reception techniques as known in the art of vehicle lights. The base, 31 , may be secured to the vehicle by securing devices, 35 , such as threaded members, rivets, and the like or the securing devices may include adhesives, snap fittings, hoop and latch systems and the like. A lens, 36 , preferably snap fits into a recession, 37 , of the base, 31 .
The shape of the secondary brake light is preferably rounded or elliptical. An elliptical light is more preferred for aesthetics and due to the increased ability to rapidly distinguish an elliptical shaped light in an environment where many lights are in the field of visual view. A particularly preferred secondary brake light is in shape commonly referred to as “cat-eye” which is approximately equivalent to the overlap region of two similar circles.
The light is not particularly limiting in the present invention. Filament based lights are typically employed for brake lights and these would be suitable for the present invention. Diodes, halogen lights, or laser based lighting methods may be employed without departing from the scope of the present invention.
The color of the secondary brake light is typically controlled by the choice of lens color or the color of the light bulb. Most preferably, white emitting light bulbs are employed with colored lens. It is most preferably that the secondary brake light not be white since this is easily confused with headlights and would not be distinguishable. Red lights are commonly employed for brake lights and universally signal danger. Red emitting secondary brake lights are a preferred embodiment. Amber lights are also a preferred embodiment due to the distinction between amber lights and other lights commonly employed in a vehicle.
The delay mechanism may be a single component or the light may comprise a delay mechanism which is integral thereto. The delay mechanism may provide a fixed delay dependent on current, amperage or other electrical signals or the delay mechanism may be controlled by a controller.
The delay controller may provide vehicle attributes upon which the delay period is based. Particularly preferred attributes include vehicle speed or change therein. For example, the delay period may increase with vehicle speed. Momentum sensors may be employed wherein rapid stopping alters the delay period. Momentum sensors are commonly employed for trailer brake activation and the mechanisms are well documented and commercially available. Mechanisms which detect the angle of the vehicle relative to the road could also be employed. A rapid change in angle may indicate a panic stop which may be utilized to lengthen the delay period, for example. The delay controller preferably does not delay the time between the brake mechanism disengagement and the termination of illumination of the secondary brake light. In one embodiment the delay controller may be a device which can be accessible for entering a delay period such as a keypad, digital or analog dial or other devices commonly employed for altering an electronic device.
The invention has been described with particular reference to preferred embodiments. It would be apparent from the description herein that other embodiments could be employed without departing from the scope of the invention which is set forth in the claims which are appended hereto. | An accessory brake light system for a vehicle comprising a secondary brake light attached to a front of said vehicle. A power source is provided for supplying power to a primary brake light. The primary brake light is attached to the rear of the vehicle. A switch connects the power to the primary brake light when the brake is engaged by an operator which causes the primary brake light to illuminate. A delay mechanism is provided which is capable of determining a delay period after the brake is engaged and the power is connected to the secondary brake light after te delay period thereby illuminating the secondary brake light. | 1 |
FIELD OF THE INVENTION
[0001] This invention pertains generally to the field of charge pumps and more particularly to methods of governing the rate of recovery in charge pumps.
BACKGROUND
[0002] Charge pumps use a switching process to provide a DC output voltage larger than its DC input voltage. In general, a charge pump will have a capacitor coupled to switches between an input and an output. During one clock half cycle, the charging half cycle, the capacitor couples in parallel to the input or power supply voltage so as to charge up to the input voltage. During a second clock cycle, the transfer half cycle, the charged capacitor couples in series with the input voltage so as to provide an output voltage twice the level of the input voltage. This process is illustrated in FIGS. 1 a and 1 b. In FIG. 1 a, the capacitor 5 is arranged in parallel with the input voltage V IN to illustrate the charging half cycle. In FIG. 1 b, the charged capacitor 5 is arranged in series with the input voltage to illustrate the transfer half cycle. As seen in FIG. 1 b, the positive terminal of the charged capacitor 5 will thus be 2*V IN with respect to ground.
[0003] Charge pumps are used in many contexts. For example, they are used as peripheral circuits on flash memory and other non-volatile memories to generate many of the needed operating voltages, such as programming or erase voltages, from a lower power supply voltage. A number of charge pump designs are known in the art and these use a regulation scheme to provide the desired output level. As the accuracy of the output can be important for the application in which it is being used, and as the accuracy of the output level depends on the regulation of the charge pump, there are consequently often needs to improve the ability of the regulation to track the output level.
SUMMARY OF THE INVENTION
[0004] An exemplary embodiment presents a method of setting a frequency of a clock for a charge pump system including the clock and a charge pump. This includes setting an initial value for the frequency of the clock and, while operating the charge pump system using the clock running at the initial frequency value, determining the ramp rate of an output voltage for the charge pump during a recovery phase. The frequency of the clock is then adjusted so that the ramp rate of the output voltage for the charge pump during the recovery phase falls in a range not exceeding a predetermined maximum rate.
[0005] According to another aspect, a charge pump system is presented. The system includes a clock circuit to provide a clock signal, a charge pump to provide an output voltage, where the charge pump is connected receive the clock signal and operate at the clock circuit's frequency, and a regulator circuit connected receive the output voltage and provide a regulation voltage derived from the output voltage to the charge pump. The system also includes a register having a settable value, where the clock frequency is responsive to the register value, and count and comparison circuitry connectable to receive the output voltage and the clock signal and determine from them the number of clock cycles the charge pump uses to recover from a reset value to a predetermined value.
[0006] Various aspects, advantages, features and embodiments of the present invention are included in the following description of exemplary examples thereof which description should be taken in conjunction with the accompanying drawings. All patents, patent applications, articles, other publications, documents and things referenced herein are hereby incorporated herein by this reference in their entirety for all purposes. To the extent of any inconsistency or conflict in the definition or use of terms between any of the incorporated publications, documents or things and the present application, those of the present application shall prevail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The various aspects and features of the present invention may be better understood by examining the following figures, in which:
[0008] FIG. 1 a is a simplified circuit diagram of the charging half cycle in a generic charge pump.
[0009] FIG. 1 b is a simplified circuit diagram of the transfer half cycle in a generic charge pump.
[0010] FIG. 2 is a top-level block diagram for a regulated charge pump.
[0011] FIG. 3 illustrates how a possible read disturb can occur from a charge pump having too rapid a ramp rate during its recovery phase.
[0012] FIG. 4 illustrates a method of determing the recovery time in a charge pump system.
[0013] FIG. 5 shows an exemplary flow for the trimming of the clock rate for a charge pump.
[0014] FIG. 6 shows some components in an exemplary embodiment of a trimmable charge pump system.
DETAILED DESCRIPTION
[0015] In a typical charge pump system, the charge pump will have several stages and the rate at which these switch between the charging half cycle of FIG. 1A and the transfer half cycle of FIG. 1B is set by the clock frequency supplied to the pump. As the pump system is intended to supply a certain output voltage at a sufficient current level, and quickly return to and maintain these levels when the output is applied to a load, the pump system is designed to meet the required specification. In contrast to a typical pump system, which is designed to recover to the prescribed levels above a certain rate, the system and methods described here present a charge pump system where the clock frequency is trimmable so that the rate of recovery does not recover too rapidly.
[0016] Due to the differ location and conditions on a circuit being supplied by a charge pump, as well as die-to-die variations, the actual ramp rate of the level supplied from the pump output when it arrives at different elements can vary significantly. In the typical current design, the pump designer will need to guarantee that the ramp rate meets a minimum value in the spec for the “slowest” elements for performance proposed. However, meeting this minimum performance for the “slowest” elements makes the ramp rate in the “fastest” supply condition very fast. (For example, in the case of a non-volatile memory device where the various elements of the memory array will, due to path differences from the pump output to different memory cells, experience slower or faster ramp rates when driven by the pump. Different parts of the array would get different level from same pump.) It has been observed that if the ramp rate is too fast, this can lead undesirable results.
[0017] To stay with the non-volatile memory device example, it has been observed in silicon that too a fast ramp rate on a charge pump's output could cause some issues read disturbs such as hot electron injection into memory cells. In an exemplary embodiment, to resolve such hot electron injection related failures, the system uses a slowed down (relative to maximum available value) pump clock such that the ramp rate is slower. Thus, rather than just considering a ramp rate above some minimum value, a maximum ramp rate is also considered and the pump clock adjusted accordingly. In most applications, this may also lead to the timing budget being elongated due to the ramp rate of pump output being is too slow for the slowest elements using the pump output. As the ramp rate can be controlled by the pump clock frequency, instead of having a fixed pump clock frequency for every die, according to one aspect presented here, the system uses a trimmable clock frequency, trimming the pump clock frequency by checking the ramp rate of the output.
[0018] In one exemplary embodiment for the current pump design, a voltage detector circuit generates a “flag” signal to count how much time it takes for this flag signal to generate. If it is slower than expectation, the pump clock frequency is increased to place the ramp rate into a desired range—that is, increased to be high enough, but also not too fast. Hence, the design can have a consistent ramp rate of pump output across die-to-die or lot-to-lot transistor variations.
[0019] FIG. 2 is a top-level block diagram of a typical charge pump arrangement. As shown in FIG. 201 , the charge pump 201 has as inputs a clock signal and a voltage Vreg and provides an output Vout. The voltage Vreg is provided by the regulator 203 , which has as inputs a reference voltage Vref and Vout. The regulator block 203 regulates the value of Vreg such that k*Vout−Vref, where, by adjusting the value of k, the desired value of Vout can be obtained. The value k can be implemented as, for example, a resistor ratio and is typically adjusted through a digital to analog converter, as will be familiar in the art. (Although not shown, the regulator ( 203 ) will also be connected to receive the voltage Vext from the external power supply to the chip.) Regulator 203 can take other supply voltages, not just Vext. Vref is a fixed reference value, such as provided by band-gap generator (not shown) with a voltage of, say, 1.2 volts. Clock_High is a clock (not shown) input to the Pump 201 .
[0020] More information on prior art charge pumps, such Dickson type pumps and charge pumps generally, can be found, for example, in “Charge Pump Circuit Design” by Pan and Samaddar, McGraw-Hill, 2006, or “Charge Pumps: An Overview”, Pylarinos and Rogers, Department of Electrical and Computer Engineering University of Toronto, available on the webpage “www.eecg.toronto.edu/˜kphang/ece1371/chargepumps.pdf”. Further information on various other charge pump aspects and designs can be found in U.S. Pat. Nos. 5,436,587; 6,370,075; 6,556,465; 6,760,262; 6,801,454; 6,922,096; 7,030,683; 7,135,910; 7,372,320; 7,368,979; 7,443,735; and 7,440,342; US patent publications 2007-0139099-A1 and 2008-0024096-A1; and application Ser. No. 10/842,910 filed on May 10, 2004; Ser. No. 11/295,906 filed on Dec. 6, 2005; Ser. No. 11/303,387 filed on Dec. 16, 2005; Ser. No. 11/497,465 filed on Jul. 31, 2006; Ser. No. 11/523,875 filed on Sep. 19, 2006; Ser. Nos. 11/845,903 and 11/845,939, both filed Aug. 28, 2007; Ser. Nos. 11/955,221 and 11/995,237, both filed on Dec. 12, 2007; and Ser. No. 12/135,945, filed Jun. 9, 2008.
[0021] When operating, the charge pump tries to accurately maintain Vout at the desired level as part of the regulation process. However, when the output is initially connected to drive a load, Vout will typically drop below the desired value and then come back up and recover to the desired value (the recovery phase). Once back up to the desired range for Vout, the pump tries to maintain the output in this range (the regulation phase). In the prior art, pumps are generally designed to recovery as quickly as is practically possible—or, perhaps more typically, to at least recover more quickly than some minimum value—since the purpose of the charge pump is to maintain the desired Vout value while supply the needed current.
[0022] The output of the pump will be typically be used by many elements on a device. Thus, in previous charge pump arrangements, the pump design would be optimized to meet a given recovery specification for the worst case conditions. All of the timing parameters would correspondingly be optimized in these worst conditions, as having too slow a recovery specification would negatively affect device performance. As noted above, however, as the output of the charge pump is delivered to elements of the circuit with differing loads and connected to the pump by different paths, the resultant ramp rate for a given pump clock frequency can differ; and, as also noted above, it is found that too fast a ramp rate could affect the reliability of a device. FIG. 3 can be used to illustrate an example of this effect.
[0023] FIG. 3 shows some EEPROM memory cells arranged into a NAND string. (More detail for various examples of non-volatile memory systems with such an arrangement of cells can be found in U.S. Pat. No. 7,120,051 or U.S. patent application Ser. No. 11/759,909, for example, which are wholly incorporated by reference here and which can referred to in order to provide context for the simplified discussion given here.) In FIG. 3 , a string of, here, five floating gate transistors ( 311 , 313 , 321 , 315 , and 317 ) are arranged in series on a substrate 301 between a pair of select transistors 303 and 305 . In a read operation of the cell 321 , the select gates 303 and 305 on either end of the string are turned on using a select gate voltage of Vsg. In FIG. 3 , the memory cell selected for sensing is cell 321 in the center of the string. In this example, a voltage BR is applied to the control gate of cell 321 . In order to the conduction of cell 321 at this control gate voltage, the other memory cells ( 311 , 313 , 315 , 317 ) in the string must be turned fully on, regardless of the data pattern stored on these cells, so that they do not affect the determination of the state on selected cell 321 . The voltage applied to these non-selected cells 311 , 313 , 315 , 317 is labeled Vread. As the value of Vread should be sufficiently high enough to turn on a memory cell for any of the data levels (here corresponding to amount of charge stored on the floating gate) the cells may hold, this level is often provided by a charge pump.
[0024] In actual implementation, the voltage level on the non-selected memory cells will naturally not instantaneously go to Vread. As the voltage is supplied from the pump, the output of the pump will be pulled down as this load is applied, go into recovery mode, and ramp back up to regulated level of Vread. As the path (through selection circuits, multiplexers, etc.) from the pump to the corresponding word lines may not all be the same, the actual values on the non-selected cells as they ramp up to Vread can vary. This difference in ramp rate between different wordlines can lead to a localized boosting, particularly for some data patterns. This can lead to a large drain-source voltage difference across some devices, with a boosted voltage Vboost on one side while the other side is at ground, and lead to punch-through and hot carrier injection into cell 313 . To resolve this type of read disturb possibility, the pump clock frequency can be set slower, so that the maximum such ramp rate of the pump output is controlled by the pump, instead of just being limited by RC parasitics between the pump and the control gate of the cells. In addition to setting the pump clock frequency, optimization of the device may also include altering other timing parameters on the device accordingly.
[0025] An exemplary method determination of the ramp rate for the charge pump can be illustrated using FIG. 4 . In FIG. 4 , the waveform 401 represents Vout from the charge pump. Between t 0 and t 1 the pump is in recovery phase, ramping up to level at the regulation phase from where it had dropped to when connected to the load. To determine how long it takes for the pump output to recover, the number of clock cycles (the waveform elk 403 ) between t 0 and t 1 are counted. This can be done by a counter which is started when an enable signal (the waveform en_elk_counter 405 ) is asserted at t 0 and de-asserted when it determines the regulation level has been reached at t 1 . As the clock frequency is known, the recovery time can be determined and adjusted as needed to put the ramp rate into the desired range by a process such as that of the flow of FIG. 5 .
[0026] FIG. 5 is an exemplary flow for setting the pump clock frequency. In this embodiment, the trimming process starts with the clock frequency slow enough so that maximum ramp rate is not exceeded and then incrementally increased as needed to be above the minimum rate, where the step size of increment is small enough to avoid overshooting the upper rate.
[0027] After starting the process, the pump and the counter are enabled at 501 . This correspond to the signal en_clk_counter 403 of FIG. 4 going high at time t 0 . Once the output of the pump reaches the desired output, corresponding to time t 1 of FIG. 4 , the counter is stopped at 503 . As both the number of clock cycles needed for the pump output to recover and the clock frequency are known, the ramp rate can be determined and compared with the desired ramp rate at 505 . The maximum and minimum ramp rates can be predetermined values, or, in some embodiments, can be dynamically determined; for example, these values could be determined by the controller's firmware based, say, on the rate of read disturbs. If the ramp rate is determined to be faster than the minimum end of the desired range, the clock frequency is acceptable and the process ends ( 507 ). If not, the clock frequency is adjusted, the pump reset, and the ramp rate checked again.
[0028] In the flow of FIG. 5 , the pump is reset at 511 and the clock frequency adjusted at 513 . Although FIG. 5 shows the pump reset first, more generally the order of 511 and 513 can be changed or both can be done at the same time, as long as the are both done before returning to 501 . As the embodiment of FIG. 5 starts with clock frequency slow enough so that the ramp rate will not exceed the maximum desired rate, the clock frequency is increased at 513 , with the increment size being small enough the it will not cause overshoot. Once the pump is reset and the frequency adjusted, the process goes through 501 , 503 , 505 again, either ending at 507 or going through another iteration if needed.
[0029] A number of variations on the process of FIG. 5 could alternately be used. For example, the initial clock frequency could be taking high enough to have the ramp rate above the minimum of the desired range and then checked at 505 to see whether ramp is below the maximum. In this case, the clock rate would instead be incrementally decreased at 513 if the comparison of 505 found the ramp rate too fast. More generally, the comparison of 505 could check the ramp rate against both the upper and lower values for the desired range and adjust either up or down at 513 as appropriate. In any of the variations, the step size for the increment at 513 can be fixed for all needed iterations or variable, but in any case the change should not be so great so at to take the ramp rate from too slow to too fast (or vice versa) in a single iteration of 513 . Also, the process here is primarily described in terms of an initial trimming operation done before the device is sent out to users, it can also be implemented as part of a dynamic process. For example, going back to the exemplary application as a peripheral circuit on a non-volatile memory, if the controller finds a relatively large amount of error that could be due to read disturb, the trimming process could be invoked and the pump clock frequency reset as needed. As noted above, there may be other parameters on the system where the charge pump is being used that would be adjusted based on the clock frequency, but as these will be specific to application, these are not included in the flow of FIG. 5 .
[0030] FIG. 6 is a bock diagram of some of the elements in an embodiment of a pump system with a trimmable clock frequency. The pump 601 and regulator 603 respectively correspond to pump 201 and regulator 203 of FIG. 2 and can be any of the various designs, such as those in the references cited above. The clock CLK 605 provides the clock signal to the pump at a frequency dependent of the value set in the register 609 . Both pump output Vout and the clock frequency are supplied to the compare/count block 607 , which can implemented in hardware, firmware, or some combination of these. When the en_clk_counter signal ( 403 , FIG. 4 ) is asserted at t 0 , the pump 601 ramps up while the compare/count block 607 keeps track of the number clock cycles while comparing Vout against the reference value, outputting the value CNT to indicate the number cycles between t 0 and t 1 . (The connection of the control signal en_clk_counter to pump 601 and compare/count element 607 is not shown.) As the number of clock cycles and the clock frequency are known, the ramp rate can be determined and the value of the register 609 adjusted as needed, indicated by the input SET. The discussion here has mainly been in the context of an initial trimming process, where the CNT signal is read out and the SET value for the register 609 set from outside. In other embodiments, the value of SET could be determined on the system itself: for example, this function could be schematically included in the block 607 , which would provide SET to the register 609 . (Although shown combined in FIG. 6 , the various functions described for block 607 could be distributed over several elements according to the implementation.)
[0031] Although the charge pump system described above can implemented as a separate circuit, it will typically occur as a peripheral element on a larger system. Returning to the example of a non-volatile memory system, such system are commonly formed of a controller chip and one or more memory chips. Although the charge pump can be on the controller or a separate chip, it is more commonly formed as a peripheral element on one or more memory chips. As all of the memory chips are usually the same, they would all have a pump circuit, although some of these may be disabled so that one or more of the chips will supply other chips. In such system, the pump 601 , regulator 603 , and maybe also the clock CLK 605 and register 609 could be placed on a memory chip, with the compare/count elements on either the controller or the memory chip, although other embodiments can distribute these elements differently.
[0032] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. Consequently, various adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as encompassed by the following claims. | A method is presented of setting a frequency of a clock for a charge pump system including the clock and a charge pump. This includes setting an initial value for the frequency of the clock and, while operating the charge pump system using the clock running at the initial frequency value, determining the ramp rate of an output voltage for the charge pump during a recovery phase. The frequency of the clock is then adjusted so that the ramp rate of the output voltage for the charge pump during the recovery phase falls in a range not exceeding a predetermined maximum rate. A charge pump system is also described that includes a register having a settable value, where the charge pump clock frequency is responsive to the register value, and count and comparison circuitry is connectable to receive the pump's output voltage and the clock signal and determine from them the number of clock cycles the charge pump uses to recover from a reset value to a predetermined value. | 6 |
This is a continuation of application Ser. No. 640,702 filed Dec. 15, 1975 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a holding apparatus, in which a holding mechanism is movably supported by an elastic mechanism and, more particularly, to an apparatus for holding a first member, which is coupled to a positioning mechanism for assembling the first and a second members.
An automatic assembly system for automatically assembling a first member such as a piston and a second member such as a cylinder has been proposed in U.S. Pat. No. 3,824,674, in which various holding apparatus have been described. All those holding apparatus provide springs placed parallel to a center axis of a drive shaft, which is coupled with a holding mechanism through springs, so as to detect a displacement or a deflection of the holding mechanism from the drive shaft, even if a small force in comparison with a total weight of the holding apparatus and a first member held thereby is effected to the first member. In a case that the first member, however, is relatively heavy in weight, the springs must be large in size and in elastic modulus. Accordingly, if a sensitivity of a detector for the displacement or the deflection is constant, the springs must be longer in length in order to produce a minimum value of the displacement or the deflection which the detector can detect, so that the holding apparatus may become large and may not be sensitive in its operation, whereas if the springs are constant in size and in elastic modulus, a detector having high sensitivity is required so that the holding apparatus may have a high cost. Further, it is more difficult to insert the piston into the cylinder when the springs become large in size and in elastic mechanism.
SUMMARY OF THE INVENTION
An object of this invention is to provide a holding apparatus being compact, in which detectors for displacement or deflection are not needed with a high sensitivity.
Another object of this invention is to provide a holding apparatus being sensitive in its operation.
In order to achieve the above objects, a holding apparatus of this invention provides a holding mechanism which assembles a first member held by the holding apparatus and a second member held by others. The holding mechanism is coupled with a drive shaft through the elastic mechanism which comprises at least two independent springs, one of which movably supports the holding mechanism in the axial direction of the drive shaft and the other of which movably supports the holding mechanism in a different direction from the axial direction thereof, whereby the holding mechanism is movably coupled with the drive shaft.
The above and other objects, features and advantages of this invention will become more apparent from the following description in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a conventional holding apparatus.
FIG. 2 is a diagram for explaining a principle of this invention.
FIG. 3 is a schematic sectional view of an embodiment of this invention.
FIG. 4 is an enlarged sectional view in a main portion of an embodiment of this invention, and
FIGS. 5 and 6 are sectional views taken along respective lines V--V and VI--VI shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a casing 100 with an opening 102 which is provided on the lower wall 103 thereof, is securely fixed to a drive shaft 101 through an upper wall 104 of the casing 100. Arms 105 of a holding mechanism are pivoted to a member 106 which is fixed to a supporting plate 107 suspended by the upper and the lower walls 104 and 103 of the casing through springs 108. The arms 105 hold a first member 109 such as a piston which is assembled to a second member such as a cylinder. A detector 110 for detecting displacement or deflection of the supporting plate 107 with respect to the drive shaft 101 is provided at a position being apart from and facing to the supporting plate 107 in the casing 100. In the above conventional holding apparatus, the reason why it becomes difficult to insert the piston into the cylinder when the springs 108 become large in size and in elastic modulus, will be explained in connection with FIG. 2. In a positioning mechanism for assembling the piston 109 and the cylinder 200, it is very difficult for the center axis 201 of the piston 109 to be placed in coincidence with the center axis 202 of the cylinder 200. So, in this status as shown in FIG. 2, it is necessary to insert the piston 109 into the cylinder 200. In this case, whether or not the piston 109 can be inserted into the cylinder 200 depends on the direction of a force F applied to the piston 109, wherein the piston 109 can be inserted easier to the cylinder 200 when the direction of the force F gets nearer to the direction Z 1 which is equal to the axial direction of the cylinder 200. When the holding apparatus holds the heavy piston, for instance, the springs 108 having a large elastic modulus are designed, so that a large force is necessarily needed in order that the supporting plate 107 is deviated in the X- or Y- directions of X-, Y- and Z- coordinates shown in FIG. 2. Accordingly, the component F X of the force F increases in comparison with the component F Z thereof, where the component F Z is of the Z- direction and the component F X is of the direction perpendicular to the Z direction. As a result, the direction of the force F is deflected from the Z 1 direction.
A principle of this invention is to use two kinds of springs, one of which is different in elastic modulus from the other, so that the component F X of the Force F applied to the piston 109 can be small in comparison with the component F Z thereof. Namely, the interference between the springs is decreased.
Referring to FIG. 3, a casing 300 with an opening 301 through which a member 302 is inserted into the casing 300, is securely fixed to a drive shaft 303. Arms 304 of a holding mechanism are pivoted to the member 302 which is fixed to a supporting plate 305. The arms 304 hold a first member 306 such as a piston which is to be assembled to a second member such as a cylinder. A detector 307 for detecting displacement or deflection of the supporting plate 305 from the drive shaft 303 is provided at a position being spaced from and facing to the supporting plate 305 in the casing 300. The supporting plate 305 is movably supported by side wall portion 308 of the casing 300 through springs 309 and 310, and sliders 311 and 312 through bearings 313 and 314, whereby the supporting plate 305 can be movable in the direction perpendicular to the axial direction of the drive shaft 303. The strength of the springs 309 and 310 may be so designed that the supporting plate 305 is shifted to the center position against a friction force due to the bearings 313 and 314 when the assembling operation for the piston and the cylinder has finished. In addition, the sliders 311 and 312 are placed on lower wall 315 through cylinders 316 and 317, and are supported by springs 318 and 319, whereby the supporting plate 305 can be movable in the axial direction of the drive shaft 303. Although the two pairs of springs 309 and 310, and 318 and 319 placed on the X- and Z- coordinates plane are shown in FIG. 3, it is needless to say that the respective pair of springs (not shown) can be placed on the Y- and Z- coordinates plane.
In the instant embodiment, the four springs arranged at right angles with respect to the axial direction of the drive shaft 303 and the four springs arranged parallel with the axial direction of the drive shaft 303 have been described, but this invention is not limited to these arrangements. Three springs, for instance, may be utilized in order to movably support the supporting plate 305 in the direction perpendicular to the axial direction of the drive shaft 303, each of which is placed on a position shifted by 120° from each other, as well as three springs, for instance may be utilized in order to movably support the supporting plate 305 in the axial direction of the drive shaft 303.
Referring now to FIGS. 4, 5 and 6, the construction of the holding apparatus of this invention will be explained in more detail. For easy understanding, the sectional view taken along lines IV--IV of FIGS. 5 and 6 is shown in FIG. 4. A casing 400 comprises an upper wall 401, a lower wall 402 with an opening 405 and a side wall 403. A drive shaft 404 is securely fixed to the upper wall 401 of the casing 400. A supporting plate 406 is securely fixed to a member 407 which is connected with a holding mechanism and is inserted into the casing 400 through the opening 405. The supporting plate 406 provides four cut portions 408 as shown in FIG. 5. Four coil springs 409 are placed in the cut portions 408, respectively, each of which is connected at one end thereof with the supporting plate therein. The respective other ends of the springs 409 are connected to respective screws 410 provided within the side wall 403 in order to adjust the strength of the springs 409, whereby the supporting plate 406 can be movable in the direction perpendicular to the axial direction of the drive shaft 404, the center axis of which is placed in registration with the center axis thereof. Further, the supporting plate 406 provides hole portions 411 and pieces 412 such as iron embeded therein. Detectors 414 for detecting the deflection of the supporting plate 406 from the drive shaft 404 are placed in the upper wall 401 and at the each position corresponding to the each piece 412, each of which comprises a permanent magnet 415 and a Hall element 416 such as a conventional Hall detector. The deflection of the supporting plate 406 is detected by the change of the magnetic flax through the Hall element 416 when the gap between the supporting plate 406 and the Hall element 416 is changed.
The combination of each hole portion 411 and each projection 413 placed on the inner surface of the upper wall 401 operates to prevent the supporting plate 406 from deflecting over the predetermined deflection which depends on the sensitivity of the detector 414. In this embodiment, the gap between the hole portion 411 and the projection 413 is a range of 1.0˜1.5 mm.
The supporting plate 406 is supported by sliders 417 through bearings 418. The respective sliders 417 are coupled with respective cylinders 419 placed on the lower wall 402 in such a manner that each slider 417 can be slid in each cylinder, and are supported by respective coil springs 420 which are coupled with respective screws 421, whereby the supporting plate 406 can be movable in the axial direction of the drive shaft 404. Each screw 421 is provided within the lower wall 402 in order to adjust the strength of the respective springs 420.
A clamping mechanism comprises plate members 422 and 423 coupled with a shaft 424 which is fixed on the lower wall 402, such as a hinge, coil springs 425 and a rod 426. Both ends of the coil springs 425 are connected with the plate members 422 and 423 through an opening 427 which is provided in the member 407 so that the plate members 422 and 423 are pressed against the member 407 with a predetermined pressure. The rod 426 is connected with a piston 429 through a joint 428, which is moved by an actuator 430 such as an air cylinder in the direction shown by an arrow mark 431. When the rod 426 is moved to the left, the member 407 is locked by the plate members 422 and 423 since they are pressed against the member 407. When the rod 426 is moved to the right, the member 407 becomes free from the plate members 422 and 423, since the distance between the plate members 422 and 423 is extended by the rod 426. The clamping mechanism is used in cases where the holding apparatus holds a first member such as a piston and positions it to a predetermined position, etc., except the assembling operation. In the above embodiment, the cylinders 419 fixed on the lower wall 402 have been explained, but, the cylinders 419 fixed on the supporting plate 406 may be so constructed that it is coupled to the lower wall 402 through the sliders 417 and the bearings 418.
While only a few forms of this invention have been shown and described, many modifications will be apparent to those skilled in the art within the spirit and scope of this invention as set forth in the appended claims. | A holding apparatus coupled to a drive shaft provides a holding mechanism. An elastic mechanism coupling the holding mechanism to the drive shaft and detectors for detecting a deflection of the holding mechanism with respect to the drive shaft. The holding mechanism holds a first member which is assembled to a second member and is controlled in response to a representative signal generated by the detectors. The elastic mechanism comprises two independent springs, one of which supports elastically the holding mechanism in the axial direction of the shaft and the other of which supports elastically the holding mechanism in the direction perpendicular to the axial direction thereof, whereby the holding mechanism is movably coupled with the drive shaft. | 8 |
DESCRIPTION OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention is directed to a novel design and implementation of chimney flue sections comprised of titanium and its alloys to provide a combination of lower weight, corrosion resistance and flexibility in varied operating environments.
[0003] 2. Background of the Invention
[0004] Power station and other industrial boiler chimneys typically consist of an approximately cylindrical concrete windshield 15 to 20 m diameter and 50-300 m tall, within which are one or more approximately cylindrical flues. When the gas is fed directly from the boiler to the flue it is warm (100° C. to 200° C.) and dry, and a conventional mild steel flue shows insignificant corrosion during operation under these conditions.
[0005] If the boiler is burning medium to high (1% or more) sulfur coal, or high sulfur oil, flue gas desulfurization (FGD) is required. This is to minimize the release of sulfur-containing and nitrogen-containing oxides into the environment, and hence minimize the formation of acid rain. In the most common form of FGD, water is sprayed into the flue gas stream, and the resulting sulfur-containing acid-rich solution is neutralized with lime or limestone. The resulting gas stream is cooler (0° C. to 100° C.) and carries moisture and residual acid, which can rapidly corrode mild steel flues, particularly if the dew point is reached under various adverse circumstances.
[0006] In order to protect the steel structure, a variety of linings have been employed. These include borosilicate brick, fibre reinforced polymer (FRP) coatings, nickel alloy linings, or titanium linings. Systems with low (50° C.) flue gas temperatures have alternatively been fitted with replacement flues constructed of factory built FRP cylinders, which are stacked in place to form the new flue.
[0007] The metallic linings have a useful life of about 15 years, and a reputation for robust and trouble-free operation and low maintenance, given appropriate alloy selection and installation. The nickel alloys used for lining flues have an advantage of simplicity of installation, since they can be welded directly onto an existing steel flue structure. Titanium alloys should not be welded to steel structures and thus another installation method is required.
[0008] From 1984 to 1998, resistance brazing titanium claddings to steel backing sheets or batten bars was used for flue installations. These batten bars or sheets can be welded directly to the steel flue structure. Titanium strips are then welded in place to cover gaps between the titanium liner sheets where the steel is exposed. This is considered to be a disadvantage with respect to this practice of the method, since the extensive on-site requires specialist trained personnel, and slows down the installation.
[0009] An alternative method was used in the 1990's, where existing brick lined flues were lined with titanium directly, being held in place by a combination of bolts into the brick and mastic between the titanium and the brick. This method requires that the pre-existing brick lining to the flue to be in good condition, and is comparatively slow and laborious.
SUMMARY OF THE INVENTION
[0010] The invention relates to a flue for use in industrial chimneys to provide corrosion resistance to the passage of corrosive gas through the chimneys. The flue comprises a plurality of formed sections hung from the top of a chimney. These sections may comprise commercially pure titanium or a titanium-base alloy. These sections are connected to each other to form an integral flue.
[0011] The plurality of formed and connected sections may include cylindrical sections.
[0012] Each cylindrical section may include butt welded edges for completion thereof.
[0013] The cylindrical sections may be joined end-to-end to form the flue. This may be achieved by welding.
[0014] Alternately, each section may include flanges connected by bolts to adjacent sections using a gasket between the sections for sealing off corrosive gas.
[0015] The titanium-base alloy may be a high-strength titanium alloy.
[0016] When a new or replacement flue is being installed irrespective of material used, flue foundations are prepared and then a hoist is installed at the top of the concrete windshield. The topmost section of the flue, with as much lining as possible in place, is then placed on the flue foundation, then hoisted up to sufficient height to allow the next highest section to be placed underneath it. The top section is then lowered onto the second section and secured to it, e.g., by bolting flanges or welding together. This process is repeated until the flue reaches the required height. The hoist is then disconnected, leaving the flue substantially freestanding, with some braces to minimize lateral movement.
[0017] In order to obtain the advantages of the corrosion resistance and light weight of titanium alloy flue linings, while avoiding the installation and quality assurance issues associated with titanium linings, one must design a flue constructed solely from titanium alloys. The flue is to be designed to be substantially suspended from a device resting on, and transferring load to, the top of the concrete windshield. This could be described as a ‘Chinese Lantern’ design.
[0018] If appropriate, the design could utilize cables or tie rods running between the flanges to bear the weight of the flue, rather than carrying the load through the sheet metal walls. Design of the flue is to be made up of cylindrical sections that can be prefabricated in a workshop. The fabrication method is envisaged to uncoil titanium strip from a coil, and form it into cylinders of the flue diameter, with a butt weld to complete each cylinder. Seam welds are to be made between these cylinders in order to build up master cylinders of a height approximately equal to the flue diameter. A ring rolled titanium section is installed by welding it to the top and bottom of each master cylinder to act as a flange and facilitate assembly of the master cylinders to form the flue.
[0019] As part of the workshop manufacture, low density insulation is installed onto the outside of the master cylinders to minimize heat loss of the flue gas during operation and facilitate inspection of the chimney. All metallic parts retaining insulation are to be made of titanium to eliminate galvanic (metal-to-metal)
[0020] The flue is installed by either bolting the flanges of the spool piece “cylinders” together or welding the spool piece cylinders together under an argon atmosphere using known TiG welding techniques for titanium. This approach leaves the flue under top tension. Side supports can be installed from the inside wall of the windshield to the outside wall of the flue if needed.
[0021] Other design variations are possible to increase the load bearing capacity of the flue such as using corrugated titanium sheets or titanium bars or rods as stiffeners in either the axial or circumferential directions. By these methods it should be possible for the flue to withstand sub-atmospheric pressure within the flue.
[0022] It may be found desirable to use standard steel cables and fittings to bear the load of the flue. These would run from flange to flange down the outside of the flue, and be tensioned to bear the load. In this case a plastic sleeve or coating may be required to protect the steel cables, and a non-metallic fitting would be used to prevent direct contact between the steel fittings and the titanium flanges. For new chimneys, additional fixtures in the height of the chimney could be utilized to transfer the weight of the flue to the concrete windshield.
[0023] Additionally, bellows sections could be incorporated as appropriate to accommodate expansion and contraction as the flue heats and cools. This might include roll forming a shallow angle down the centreline of some titanium strips, making each master cylinder a ‘fold in the Chinese lantern’.
[0024] Various titanium alloys could be utilized in different locations in the flue to minimize the cost and maximize the durability. For example, higher strength alloys would be used near the top of the flue where the load is greatest and Pd or Ru bearing grades would be used where the corrosion conditions are predicted to be most severe.
[0025] The method of seam welding could be by TIG; Plasma; laser; etc. Alternatively, it may be adequate for some seams to use lock seam joints, as used in the installation of sheet metal roofing. In principle, the above method of flue design and construction could be used for other metallic or non-metallic materials, or a combination of both. Titanium does offer particular advantages in both corrosion resistance and lower density than other metals.
[0026] For retrofit chimneys, the flue spool piece section approach also works well. When the segments between vertical brick overlaps inside the chimney is about 9 m spacing, the flue sections should be pre-fabricated to about an 8 m tall ‘can’ in 2-4 cylindrical segments (depending on transportation issues) and constructed with small flanges directed in towards the inside of the cylindrical flue sections. A Teflon gasket can be inserted between the flanges of two adjacent sections to provide a seal. All the holes could be pre-drilled so that assembly of the flue would go quickly when attaching and fastening nut and bolt fasteners. Since there would be the brick for support, the flange could be formed integrally or welded onto the cylindrical ‘can’. The flanges at the top and bottom also are directed inward towards the inside of the cylinder. Pre-made expansion joints are installed between the bottom flange of one can and the top flange of the other can that bridge the offset in the brick. This is similar to the above design for new construction, except the flange would be on the inside of the cylindrical sections instead of on the outside. The expansion joint could be fabricated from titanium or another suitable inert material such as Teflon on-site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is an elevation view in partial cross-section showing the assembly sequence for the construction of a flue in accordance with the invention;
[0028] FIG. 2 is an elevation view in partial cross-section showing an assembled flue in accordance with the assembly sequence of FIG. 1 ;
[0029] FIG. 3 is a view showing joined sections in accordance with the assembly of the flue in accordance with the invention and shown in FIG. 2 ; and
[0030] FIG. 4 is an enlarged view of a portion of the joined sections of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Each 8 m can fabricated from 1.5 mm strip would weigh just over 2,300 lbs (for a 6 m diameter flue). The flanges can be welded onto the parts of the cylindrical sections of the flue in the workshop and a final titanium weldment can be made on-site to complete the fabrication of a single cylindrical spool piece section. The flanges can be bolted together on-site as the upper section is lowered onto the lower section. It might also be possible to rest each individual can or spool piece cylinder on the concrete support coming out from the chimney, thereby eliminating almost any hanging stresses and would make each brick/titanium segment a single unit.
[0032] It is estimated that the total installed cost of the titanium flue should be lower than that of a steel flue lined to resist wet FGD conditions using borosilicate bricks or nickel alloys. The high corrosion resistance of titanium under these conditions, and the low maintenance required will ensure advantageous life cycle costs. In the event of a small leak of flue gas through a minor fabrication defect there will be no corrosion damage to the structure since the flue is made entirely of titanium.
[0033] With reference to the drawings, and for the present to FIG. 1 , a flue, in accordance with the invention, designated generally as 10 is formed of a plurality of titanium cylindrical sections 12 , which are joined and hung from the top portion of the chimney 14 from hanger 16 . When assembly is completed, the resulting flue structure is as shown in FIG. 2 .
[0034] With reference to FIGS. 3 and 4 , cylindrical sections 12 may be provided with a gasket 18 . As shown in FIG. 4 , each cylinder 12 to be joined may be provided with a flange 20 to result in the mating flange structure shown in FIG. 4 . A bolt 22 may connect these flanges, as shown in FIG. 4 , to complete the joining of the cylindrical sections 12 .
[0035] The term “higher strength titanium alloys” as used herein is defined as a titanium alloy containing additive elements to increase tensile strength to that above the tensile strength of ASTM B265 Grade 2. Examples include Ti Grade 9 and Ti Grade 12. | A novel flue design using titanium sections, affording rapid construction, corrosion resistance for low maintenance and inertness over a wide range of operating conditions. The lower density of titanium versus steel or nickel alloys makes this flue design structurally possible and results in lower cost flues compared to flues of other alloys. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application Ser. No. 61/600,850, filed Feb. 20, 2012, the contents of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to mattress covers and, more particularly, to a mattress cover capable of accommodating mattresses having a variety of different thicknesses or depths. Still more particularly, the present invention is directed to a mattress cover which will fit securely on mattresses of various thicknesses without migrating upward and off.
BACKGROUND
Mattresses today are available in a wide variety of sizes and styles. Among the most popular sizes are twin, queen and king. Although the mattresses in each of these size groups have more or less the same nominal length and width dimensions, the thickness or depth dimension of the mattresses often differs substantially among mattresses within the same size group based upon such factors as the construction of the mattresses, their style, the amount of padding, etc.
In view of the large range of thicknesses in which mattresses are available, it is difficult to make a mattress cover which will fit snugly on all of the mattresses within a given size group. For example, a conventional mattress cover, also known as a bed sheet or fitted sheet, typically includes top panel, a skirt extending from the periphery of the top panel and an elastic band along the lower edge of the skirt intended to fit under the mattress to hold the mattress cover in place. Mattress covers of this type typically fit poorly on thin mattresses so that, even with extensive tucking, such mattress covers sag, wrinkle and hang loosely when in use, such that the mattress cover often slips relative to the mattress. At the other extreme, these conventional mattress covers frequently will have a skirt portion which is not sufficiently deep to reach below mattresses which are relatively thick, and therefore will frequently slip off of these mattresses.
To address the foregoing problems, a wide array of systems have been developed for securely holding mattress covers to mattresses within a wide range of thicknesses, as shown, for example in U.S. Pat. No. 5,249,322 to Seago and U.S. Pat. No. 5,479,664 to Hollander. These systems have met with little success, often introducing problems which did not exist with conventional mattress covers. For example, one device includes elastic anchor bands attached diagonally across each corner of the panel for engaging below the corners of the mattress. These mattress covers do not engage the mattress securely, and the anchor bands tend to disengage the mattress easily. As a result, the skirt migrates upward while in use to the point that it no longer engages the sides of the mattress and no longer effectively covers the mattress. This is particularly inconvenient when a person is sleeping on the mattress.
A further drawback to prior art mattress covers has been that the placement of discernible indicia on the mattress covers has been visually objectionable. In this regard, any discernible indicia placed on either the top panel of the mattress cover or the skirt portion thereof would ordinarily be visible through a sheet placed over the mattress cover, and would therefore detract from the aesthetic appearance of the sheet. This problem has made it difficult for manufacturers and other businesses to place ornamentation, particularly their trademarks, logos or other symbols, on the mattress covers.
There thus exists a need for a mattress cover which is simple in construction and inexpensive to produce, yet which is capable of accommodating the wide range of mattress thicknesses within a given size group with a proper fit which is neither too loose so as to look sloppy, or too tight so as to easily slip off of the mattress. There also exists a need for a mattress cover to which ornamentation, including indicia of source and other symbols, can be applied without interfering with the aesthetic appearance of a sheet placed over the mattress cover.
SUMMARY
Disclosed herein is a mattress cover comprising a top panel, a skirt extending downward from the periphery of the top panel, a securing belt attached to the skirt and a means of adjusting the length of the belt. The securing belt may be integrated into the skirt by various methods including but not limited to a pocket or sleeve looping around the center or bottom of the skirt, the securing belt may also be integrated by means of lacing in and out, an integrated channel, a plurality of belt loop structures or the like. The length of the belt may be adjusted by means of an adjusting buckle, a knot, a hook and grommet device, Velcro, button snaps or the like.
Accordingly, the primary object of the present invention is to provide a mattress cover that overcomes the disadvantages of the prior art.
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
FIG. 1 is a perspective view of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 2 is a perspective view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 3 is an enlarged view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 4 is an enlarged view of an alternative embodiment of a mattress cover having a securing beltin accordance with the principles of the present invention;
FIG. 5 is a perspective view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 6 is a perspective view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 7 is a perspective view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention;
FIG. 8 is a perspective view of an alternative embodiment of a mattress cover having a securing belt in accordance with the principles of the present invention.
DETAILED DESCRIPTION
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.
Knitted elastic is a fabric made out of any flexible material woven together that will allow the fabric to stretch. The knitted elastic belt used within a fitted sheet, or mattress cover, will create a tight and snug fit around the mattress. Once incorporated into the fitted sheet or mattress cover, the belt will adjust and secure into place. The elastic belt will loop around and come through a middle section around the fitted sheet though a hole, the two ends of the belt will exit either on the shorter or longer side of the fitted sheet and connect or fasten with a buckle, magnet, Velcro® and/or any other device capable of adjusting and securing the length of the belt. This new securing system may be hidden within the fitted sheet, or mattress cover with access given through a middle section covered by a flap.
Depending on where the belt is placed, fabric may be sewn on top of the knitted elastic so the belt is not shown. This may be done for aesthetic purposes and several fabrics may be used. The secured fitted mattress cover may be sized for all sizes including, twin, full, queen and king size beds. It may similarly be used for pet beds, children's mattresses, sofa beds, murphy beds or other mattresses.
FIG. 1 shows a mattress cover in accordance with the principles of the present invention. Mattress cover 30 may have a top panel 32 and a skirt 33 . Sleeve 36 may extend about the entire perimeter of the mattress cover 30 and may be incorporated into skirt 33 . A securing belt 34 may extend through the entire length of the sleeve 36 and may be adjusted by means of buckle 38 . The securing belt 34 maybe elastic or inelastic. Buckle 38 may be of any design that allows adjustment of the overall length of securing belt 34 . It may be desirable to use a plurality of belt loops, rather than a sleeve 36 in order to hold securing belt 38 in place.
FIG. 2 is an enlarged view of a mattress cover skirt 40 very similar to the one shown in FIG. 1 . FIG. 2 shows an alternative configuration in accordance with the principles of the invention. Skirt 40 may have a sleeve 42 that may extend its entire perimeter. Belt 44 may extend the length of the sleeve 42 . The length of belt 44 may be adjusted by means of buckle 46 . Flap 48 may be attached to sleeve 42 . Flap 48 may have sufficient dimensions to completely cover the portion of the belt 44 that is not physically within sleeve 42 . Snap 50 and 52 may be used to removably affix flap 48 over the exposed portion of the belt 44 and buckle 46 .
FIG. 3 shows the mattress cover skirt 40 of FIG. 2 where flap 48 is snapped into place by means of snap 50 in order to cover belt 44 . When the flap 48 is snapped into place, the belt 44 is no longer visible. Flap 48 may optionally include a placard 51 that may include one or more ornamental features, for example, a trademark, logo or other attractive design. The flap 48 used in conjunction with a mattress cover skirt and a sleeve may be used whether it is located on the long or short sides of a mattress cover skirt. The material of flap 48 may be the same or different from the material of sleeve 42 . Placard 51 may be comprised of any material, including but not limited to, metal, plastic, carbon fiber, cotton, and vinyl. Optionally placard 51 may be removable such that alternative placards may be incorporated with the flap 48 . FIGS. 2 and 3 show a snap 50 and 52 used to removably affix the flap 48 to cover the belt 44 . Other suitable means of affixing the flap 48 to the sleeve 42 may be utilized. Other means include, but are not limited to, a button, a magnetic clasp, laces, Velcro® and the like.
FIG. 4 shows a mattress cover 10 having a top panel 14 and a skirt 16 . A flat fabric sewn onto the skirt 16 of the mattress cover 10 may create a sleeve 12 that runs the entire perimeter of the mattress cover 10 . The sleeve 12 and the flat piece of fabric creating it may be any design. A securing belt 18 may be incorporated into the skirt within the sleeve 12 in a manner similar to that of a string within an elastic band commonly used in sweat pants or men's bathing suits which may be adjusted by a buckle, such as a slider buckle, as commonly used on the straps of backpacks. Securing belt 18 may optionally be elastic, or inelastic. The skirt 16 may incorporate elastic material as well. Buckle 20 may be used to adjust the securing belt 18 to an appropriate length.
A knitted elastic belt may be interwoven through the skirt of a mattress cover having a top panel. The belt may loop in and out of the skirt of the mattress cover sheet through a plurality of slits. The ends of the knitted elastic belt may exit either on short or longer side of the fitted sheet. The two ends may of the belt may fasten onto a buckle having a placard similar to the placard of FIG. 4 . A mattress cover may have a top panel and a skirt that overlays the sides of a mattress. A securing belt may be integrated throughout the entire skirt. The securing belt may be laced repeatedly between the inside and outside of the skirt by means of a plurality of slits for the entire length of skirt. A securing belt may include a buckle that may facilitate adjustment of the securing belt. By tightening the securing belt by means of the buckle, the mattress cover may firmly engage the entire mattress, thereby preventing the skirt from riding upwards and becoming disengaged with a mattress.
The buckle may also include a placard that may optionally be used to display a logo or other image. Optionally, the buckle itself may be used as an indicia of source or be ornamental in nature. The securing belt may be made of a variety of materials and may be elastic, comprised of lycra or other material, or may be inelastic and comprised of a fabric such as cotton, leather, or other material. The securing belt may be of a knitted elastic as described above, or may be comprised of any suitable material, elastic or inelastic and may be chosen in part based upon aesthetic reasons. The belt may be comprised of a wide range of materials, even metal or chain may be used. The skirt may include an elastic band upon its bottom. It may be preferable that the belt is positioned on the outside of the skirt at the corners. This may decrease the tendency of a mattress cover to ride upward while the mattress is in use. Optionally, a plurality of belt loop structures may be placed about the skirt to engage the belt with the skirt, as an alternative to the lacing in and out of the skirt.
Any buckle design may be used to adjust the length of a securing belt. Other methods of adjustment may also be suitable, such as, for example, replacing the securing belt with one of a suitable length, tying a knot instead of using a buckle, using a securing belt having one or more hooks for attaching to an eyelet or grommet in the skirt, the securing belt or the mattress itself.
FIG. 5 shows a mattress cover 80 having a top panel 82 and a skirt 84 . A belt 86 may be sewn onto the skirt 84 . The belt 86 may be of any design. Alternatively, the belt 86 may be glued around the mattress cover's skirt 84 . A portion 88 of the belt 86 may not be glued so that it may be adjusted. The length of the free portion 88 of the belt 86 may be adjusted by means of a buckle 90 . In this embodiment, the free portion 88 of belt 86 and the buckle 90 are located on the long side of the mattress covers skirt 84 . However, the free portion 88 and buckle 90 may optionally be located on the short side of the skirt 84 .
FIG. 6 shows an alternative embodiment of a mattress cover 100 and accordance with the principles of the invention. Mattress cover 100 may have a top panel 101 and a skirt 102 . A belt 104 extends the length of the skirt 102 on the inside. The belt 104 may be stitched or glued or otherwise attached to the inside of skirt 102 . Alternatively, the belt 104 may be attached to the inside of skirt 102 by a series of belt loops. Belt 104 exits to the outside of skirt 102 by means of slits 108 . A buckle 106 on the exterior of skirt 102 allows for adjustment of the belt 104 .
FIG. 7 shows another alternative embodiment of a mattress cover 110 in accordance with the principles of the invention. Mattress cover 110 may include a top panel 112 and a skirt 114 . A belt 116 may extends along the entire length of the skirt 114 and be adjustable by means of buckle 118 . As with the other embodiments, the buckle may be located anywhere along the skirt, but for simplicity has been shown on the long side of the skirt 114 . All four corners 119 of the mattress cover 110 may include a plurality of belt loops 120 . The belt loops 120 may hold the belt 116 in place about the corners 119 . Along the sides of the skirt 114 between the corners 119 . The belt 116 may be glued or sewn securely to the skirt 114 or may be free and not otherwise attached to the skirt 114 . No one 16 may be elastic or inelastic.
FIG. 8 shows an alternative embodiment of a mattress cover 130 in accordance with the principles of the invention. The mattress cover 130 may have a top panel 132 and a skirt 134 . At the bottom of skirt 134 may be a belt 136 that may extend the entire length of the skirt 134 . Belt 136 may have a buckle 138 or similar device for providing an adjustment of the length of the belt 136 . The belt 136 may be glued and/or sewn onto the skirt 134 . Alternatively, the bottom of skirt 132 may be provided with a plurality of belt loops that hold the belt into place. The securing belt may be integrated into the skirt by various methods including but not limited to a pocket or sleeve looping around the center or bottom of the skirt, the securing belt may also be integrated by means of lacing in and out, an integrated channel, a plurality of belt loop structures or the like.
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. | A mattress cover includes a securing belt about its skirt to aid in engaging and fixing the skirt to a mattress, thereby minimizing the tendency of a skirt to migrate upward on the mattress during use. The belt may be attached to the skirt by means of a sleeve extending the length of the skirt, lacing, belt loop structures, an integrated channel, Velcro® or similar devices. The belt may be adjusted by means of a buckle, a knot or other similar devices. | 0 |
RELATED APPLICATIONS
[0001] This application is a continuation application of US patent application entitled “SOFTWARE ARCHITECTURE FOR DUAL MODE PHONE AND METHOD OF USE” Ser. No. 11/467,081, docket number TUTL 00061, filed on Aug. 24, 2006, and incorporated by reference in its entirety, herein.
TECHNICAL FIELD
[0002] The present invention generally relates to wireless communication devices and more particularly relates to efficient use of processor and memory resources one dual mode wireless communication devices.
BACKGROUND
[0003] Conventional dual mode wireless communication devices are inefficient in their use of resources, in particular during dual mode operation. One significant disadvantage of these conventional devices is the inefficient software architecture employed by these devices that inherently cause the device to operate inefficiently. Additionally, conventional dual mode devices lack the ability to seamlessly transition between different air interface modes of operation when the network for a first air interface cannot be acquired or when the signal strength is too low to maintain a connection on the first or second air interface. Accordingly, what is needed is a system and method that addresses these problems with the conventional dual mode communication devices and their methods of use.
SUMMARY
[0004] Described herein are software architectures for a dual mode wireless communication device and a method of use for the architecture and device that provides efficient and effective use of the processor and memory capabilities of a first air interface and the processor and memory capabilities of a second air interface on the dual mode wireless communication device. Various architectures are described that efficiently spread a plurality of operational modules across first and second air interface processors for efficient dual mode operation of a dual mode wireless communication device. Additionally disclosed are procedures for transitioning from a first air interface mode to a second air interface mode and vice versa based on user preferences, environmental variables, and factors such as signal strength or availability.
[0005] Among others, certain advantages of the software architectures and method of use include: (1) flexibility for future modifications based on the modular and extensible architecture; (2) minimal changes to the existing user interface and applications; (3) abstractions to third party interfaces; and (4) simplified portability to various air interface chip solutions. Other features and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts.
[0007] FIG. 1 is a high level block diagram illustrating an example dual mode wireless communication device according to an embodiment of the present invention.
[0008] FIG. 2 is a block diagram illustrating a plurality of modules of an example dual wireless communication device according to an embodiment of the present invention.
[0009] FIG. 3 is a block diagram illustrating an example software architecture for a dual mode wireless communication device according to an embodiment of the present invention.
[0010] FIG. 4 is a block diagram illustrating an example alternative software architecture for a dual mode wireless communication device according to an embodiment of the present invention.
[0011] FIG. 5 is a block diagram illustrating an example architecture for a plurality of modules and interfaces in a dual mode wireless communication device according to an embodiment of the present invention.
[0012] FIG. 6 is a flow diagram illustrating an example process for efficient dual mode communication according to an embodiment of the present invention.
[0013] FIG. 7 is a flow diagram illustrating an example process for call handoff from a first air interface to a second air interface according to an embodiment of the present invention.
[0014] FIG. 8 is a flow diagram illustrating an example process for acquiring a second air interface connection when no first air interface signal is available according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0015] Certain embodiments as disclosed herein provide for an efficient architecture for a dual mode wireless communication device and methods of use for dual mode operation of the device. For example, one embodiment provides for a dual mode wireless communication device to acquire a connection from a second air interface when a first air interface connection is unavailable or when the second air interface connection is preferred.
[0016] After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. In particular, the primary embodiment described herein references a dual mode wireless communication with air interfaces for a code division multiple access (“CDMA”) network and an 802.11(x) (“WiFi”) network. However, in alternative embodiments the air interfaces of the dual mode wireless communication device may provide access to other cellular networks such as GSM and other data networks such as WiMax. Accordingly, it should be understood that the primary embodiment described herein is presented by way of example only, and should not be construed to limit the scope or breadth of the present invention.
[0017] FIG. 1 is a high level block diagram illustrating an example dual mode wireless communication device 15 according to an embodiment of the present invention. In the illustrated embodiment, the dual mode device 15 comprises CDMA processor 20 and WiFi processor 30 . Device 15 is also configured with data storage area 17 .
[0018] Wireless communication device 15 can be any of a variety of wireless communication devices, including a cell phone, personal digital assistant (“PDA”), personal computer (“PC”), laptop computer, PC card, special purpose equipment, or any combination of these and other devices capable of establishing a wireless communication link over a wireless communication network (not shown). The wireless communication device 15 may also be referred to herein as a handset, wireless device, mobile device, device, wireless unit, or mobile unit.
[0019] A wireless communication network may include a plurality of networks including private, public, circuit switched, packet switched, personal area networks (“PAN”), local area networks (“LAN”), wide area networks (“WAN”), metropolitan area networks (“MAN”), or any combination of the these. Other network types may also be included as needed to facilitate wireless communications by device 15 on a CDMA network or a WiFi network.
[0020] Data storage area 17 that is configured with wireless communication device 15 can be any sort of internal or external memory device and may include both persistent and volatile memories. The function of data storage area 17 is to maintain data for long term storage and also to provide efficient and fast access to instructions for applications that are executed by the respective device or module.
[0021] FIG. 2 is a block diagram illustrating a plurality of modules of an example dual wireless communication device 15 according to an embodiment of the present invention. In the illustrated embodiment, handset 15 configured for dual mode operation comprises user interface call module 50 , user interface network browser module 55 , user interface WiFi module 60 , CDMA stack module 65 , TCP/UDP/IP stack module 70 , SIP stack module 75 , RTP stack module 80 , voice codec module 85 , jitter buffer module 90 , WiFi stack module 95 , WiFi supplicant module 100 , CDMA stack interface module 105 , SIP stack interface module 110 , RTP stack interface module 115 , TCP/UDP/IP stack interface module 120 , WiFi stack interface module 125 , and CDMA and WiFi interface driver module 130 .
[0022] In combination, the various modules 50 through 130 provide handset 15 with the capability to communication over a CDMA network and also a WiFi network. The various user interfaces, module interfaces, communication stacks, and other modules facilitate a functional dual mode handset in operation.
[0023] FIG. 3 is a block diagram illustrating a first example software architecture for dual mode handset 15 according to an embodiment of the present invention. In the illustrated embodiment, handset 15 comprises CDMA processor 20 and WiFi processor 30 . The various modules that comprise a dual mode handset as previously described in FIG. 2 are distributed for execution and operation on the two processors.
[0024] CDMA processor 20 comprises operating system module 60 and BREW module 50 . BREW module 50 is configured to execute user interface WiFi module 60 when the user is communicating over the WiFi network.
[0025] Operating system module 60 is configured to execute user interface call module 50 , user interface network browser module 55 , CDMA stack module 65 , SIP stack module 75 , WiFi supplicant module 100 , CDMA stack interface module 105 , SIP stack interface module 110 , RTP stack interface module 115 , TCP/UDP/IP stack interface module 120 , WiFi stack interface module 125 , and CDMA and WiFi interface driver module 130 .
[0026] WiFi processor 30 is configured to execute TCP/UDP/IP stack module 70 , RTP stack module 80 , voice codec module 85 , jitter buffer module 90 , WiFi stack module 95 , RTP stack interface module 115 , TCP/UDP/IP stack interface module 120 , WiFi stack interface module 125 , and CDMA and WiFi interface driver module 130 . Although CDMA processor 20 and WiFi processor 30 redundantly execute some of the modules, this redundancy provides an efficient scheme for robust communications in either CDMA mode or WiFi mode. Advantageously, CDMA processor 20 and WiFi processor 30 each execute CDMA and WiFi interface driver module 130 , which provides a communication interface between the two processors and modes of operation.
[0027] FIG. 4 is a block diagram illustrating an alternative example alternative software architecture for dual mode handset 15 according to an embodiment of the present invention. In the illustrated embodiment, handset 15 comprises CDMA processor 20 and WiFi processor 30 . The various modules that comprise a dual mode handset as previously described in FIG. 2 are distributed for execution and operation on the two processors.
[0028] In the illustrated architecture, the majority of the modules are advantageously deployed on CDMA processor 20 (which comprises operating system module 60 and BREW module 50 ) and enabled by operating system module 60 . BREW module 50 is configured to execute user interface WiFi module 60 when the user is communicating over the WiFi network.
[0029] Operating system module 60 is configured to execute user interface call module 50 , user interface network browser module 55 , user interface CDMA stack module 65 , TCP/UDP/IP stack module 70 , SIP stack module 75 , RTP stack module 80 , voice codec module 85 , jitter buffer module 90 , WiFi supplicant module 100 , CDMA stack interface module 105 , SIP stack interface module 110 , RTP stack interface module 115 , TCP/UDP/IP stack interface module 120 , WiFi stack interface module 125 , and CDMA and WiFi interface driver module 130 .
[0030] In the illustrated architecture, the modules deployed on WiFi processor 30 are advantageously reduced such that WiFi module 60 is configured to execute WiFi stack module 95 , WiFi stack interface module 125 , and CDMA and WiFi interface driver module 130 . Accordingly, redundancy of module execution is reduced in the illustrated embodiment to improve the efficiency and robustness of communications in either CDMA mode or WiFi mode. Additionally, CDMA processor 20 and WiFi processor 30 each execute CDMA and WiFi interface driver module 130 , which provides a communication interface between the to processors and modes of operation.
[0031] FIG. 5 is a system diagram illustrating an example architecture for a plurality of modules and interfaces in a dual mode handset 15 according to an embodiment of the present invention. In the illustrated embodiment, the handset 15 comprises a CDMA processor 200 and a WiFi processor 210 . For example, CDMA processor 200 can be a mobile station modem (“MSM”) single chip solution and the WiFi device 210 can be a Marvell® card that is integrated with the handset 15 .
[0032] In the illustrated embodiment, the CDMA processor executes a plurality of application modules, interface modules, and WiFi modules. It also executes a CDMA stack and abstraction layer modules for the operating system and sockets. The application modules include a browser for network browsing, a WiFi client, and a native user interface. Additionally the applications include a BREW module and an OEM module that support respective application modules. Certain WiFi specific extensions are provided in a WiFi extensions module that operates in conjunction with the BREW module and the OEM module.
[0033] The interface modules include a sound module, a data services module, a dual mode controller module, a call manager module, and a wireless message system module. WiFi specific extensions are added to the data services module, the call manager module, and the wireless message service module to allow for interoperability between the CDMA processor 200 and the WiFi processor 210 .
[0034] The WiFi modules include a WiFi audio module, a WiFi sockets module, a WiFi main controller module, a WiFi message module, a WiFi supplicant module, a MUX module, an secure digital input output (“SDIO”) module, and a session initiation protocol (“SIP”) client module.
[0035] Additionally, a plurality of interfaces communicatively connect the various modules. For example, interface A between the WiFi client module and the BREW module provides an application programming interface (“API”) to the WiFi client for performing 802.11 related procedures, interface B between the WiFi main controller module and the SIP client module provides an API to the WiFi main controller module for performing call related procedures using the SIP client, interface C between various clients and the operating system abstraction layer provides an API for operating system services, interface D between various clients and the socket abstraction layer provides an API for socket services, interface E between the SIP client module and the MUX module provides an API to the SIP client module to send and receive proprietary commands and responses via the SDIO module, interface F between the WiFi supplicant module and WiFi message module provides an API to the supplicant for performing 802.11 related security procedures, and interface G between the CDMA processor and the WiFi processor via the SDIO module provides a messaging API between the WiFi modules on the CDMA processor and the various modules on the WiFi processor.
[0036] Additional interfaces are also provided. For example, interface 1 between the call manager module and the WiFi main controller module provides an API for call related procedures, interface 2 between the WiFi audio module and the sound module provides an API for periodically sending and receiving PCM data (e.g., every 20 ms), interface 3 between various clients and the MUX module provides an API for clients that want to read and write data to the WiFi processor via the SDIO module, interface 4 between the MUX module and the SDIO module provides an API for DAL to read and write data via the SDIO module, interface 5 between the BREW module and the WiFi main controller module provides an API for communication between the BREW module and the WiFi messages module for performing 802.11 procedures, interface 6 between various clients and the WiFi sockets module provides an API for the data services module and the socket abstraction layer to perform socket related activities via the SDIO module, interface 7 between the WiFi main controller and the WiFi audio module provides an API for the WiFi main controller module to start and stop audio, interface 8 between the WiFi main controller and the WiFi sockets module provides an API for the WiFi main controller module to communicate with the WiFi sockets module for socket clean up, interface 9 between the dual mode controller module and the WiFi main controller module provides an API for the dual mode controller to communicate with the WiFi main controller, interface 10 between the dual mode controller module and the call manager module provides an API for the dual mode controller to communicate with the call manager module, and interface 11 between the dual mode controller module and the data services module provides an API for the dual mode controller to know the current state of the handset 15 .
[0037] In one embodiment, the native user interface module provides the user interface subsystem for the handset 15 , the browser module provides the user interface for network browsing, the WiFi client module controls and determines access to a WiFi network, the wireless message system module interacts with the user interface module to provide SMS functionality, the dual mode controller module interacts with the call manager module, data services module, and WiFi main controller modules to provide DCMA and WiFi access control, the call manager module interacts with the user interface module for call related features, the data services module interacts with the user interface module for data related features, the sound module handles the transmission and reception of user voice to and from the microphone and speaker on the handset 15 , the WiFi main controller module interacts with the call manager module, the dual mode controller module, and the SIP client module to provide WiFi services for the handset 15 , the WiFi sockets module interacts with the data services module and the socket abstraction layer module to provide socket APIs via the SDIO module to the TCP/UDP/IP stack on the WiFi processor, the WiFi audio module interacts with sound module to periodically send and receive PCM coded voice data (e.g., every 20 ms) and encode and decode the voice data over SDIO, the WiFi message module encodes and decodes WLAN messages to and from the firmware on the WiFi processor 210 , the WiFi supplicant module provides key generation for encryption and decryption of data sent over a wireless link between the handset 15 and an access point, the SIP client module implements the functionality described in various related requests for comments, the software multiplexer/demultiplexer module abstracts the SDIO driver and makes the various WiFi modules independent of the hardware interface and also buffers the outgoing and incoming data using queues, the SDIO module provides the hardware interface and drivers between the CDMA processor and the WiFi processor, the operating system abstraction layer abstracts the services of the operating system so that various modules (e.g., third party modules) can be easily integrated, and the socket abstraction layer abstracts various socket APIs so that various software modules (e.g., third party modules) can be easily integrated.
[0038] In one embodiment, certain variables are advantageously maintained by the handset 15 to facilitate efficient dual mode operation. For example, the machine identification number (“MIN”) can be maintained for use by the SIP client module, in addition to password information and display name information that can also be maintained for use the SIP client module. Additionally, SIP server information can be maintained including the IP address and port number of the SIP server and the fully qualified domain name of the server. Other advantageous information that can be maintained in one embodiment includes certain parameters or limits, e.g., the number of retries for CDMA acquire when WiFi mode is available, the number retries for downloads, the time period for periodic registration, whether WiFi mode is enabled or disabled, the mode preference (CDMA or WiFi), whether dynamic IP address assignment is enabled, and user defined parameters, for example IP configuration information including IP address, netmask, broadcast IP address, default gateway information, and domain name server information, just to name a few.
[0039] Advantageously, one embodiment may provide functionality in the user interface by including an annunciator module configured to display the WiFi icon on the screen of the handset 15 and display the signal strength for the WiFi signal. The user interface may also include a settings module that provides a submenu for enabling and disabling WiFi mode, establishing a mode preference and dynamic host configuration protocol (“DHCP”) settings, and IP address configuration (if DHCP is not enabled). Other message modules may also be provided that give status updates during firmware downloads, the SIP registration process, and other WiFi enabled states. An idle screen module can also be provided that displays the WiFi profile selected by the WiFi client module and displays the name of the internet service provider or WiFi network provider. Additional functionality can also be provided through a service handling module that allows the user to add WiFi as a service on a field deployed handset 15 .
[0040] In the illustrated embodiment, the WiFi client module is configured to operate as a dynamically loadable BREW application that can run in the background. The various WiFi extension modules can be implemented as static extensions to their respective underlying modules.
[0041] FIG. 6 is a flow diagram illustrating an example process for efficient dual mode communication according to an embodiment of the present invention. The illustrated process can be carried out in alternative embodiments by devices such as the dual mode handsets previously described with respect to FIGS. 2 through 5 . Initially, in step 350 the handset is initialized, for example during power up or a reset procedure. Next, in step 355 the handset acquires the CDMA signal. Once the CDMA signal has been acquired the handset checks to determine if WiFi access is configured to be enabled, as shown in step 360 . In one embodiment, a variable may be set by the user that instructs the handset to automatically enable WiFi access. Alternatively, WiFi access may be the preferred mode for the handset. As determined in step 360 , if WiFi is not to be enabled, then in step 365 the handset enters a state where there is CDMA traffic or CDMA is idle. The handset may be configured to periodically check back to see if WiFi should be enabled, which would return the process to step 360 . Alternatively, a user may manually instruct the handset to enable WiFi, which would also return the process to step 360 .
[0042] As determined in step 360 , if WiFi is to be enabled, then in step 370 the handset checks to see if there is currently active CDMA traffic. If there is active CDMA traffic, then in step 375 the handset waits for the CDMA call to end or fail, at which time the CDMA traffic ends. When there is no CDMA traffic, as determined in step 370 , the handset performs a session initiation protocol (“SIP”) registration in step 380 to enable voice communications on the WiFi network. In one embodiment, SIP registration includes updating a voice over internet protocol (“VoIP”) server that associates an IP address with a phone number so that calls to the telephone number for the handset are correctly routed to the IP address of the handset on the WiFi network as VoIP calls.
[0043] After the handset has registered then it is available for VoIP traffic and maintains a state where it may be idle or active with respect to VoIP traffic, as shown in step 385 . Advantageously, the handset periodically checks in step 390 to determine whether the WiFi signal strength remains above a certain threshold. The threshold may be set so that a certain level of signal strength is maintained while the handset is available for VoIP traffic. If, as determined in step 390 , the WiFi signal strength is adequate, handset maintains its state. If the WiFi signal strength is too low, however, then the handset deregisters in step 395 and returns to step 355 where the handset re-acquires the CDMA signal. In this fashion, a handset may efficiently and seamlessly transition between CDMA and WiFi modes during operation.
[0044] FIG. 7 is a flow diagram illustrating an example process for call handoff from a first air interface to a second air interface according to an embodiment of the present invention. The illustrated process may be carried out in various embodiments by dual mode handsets such as those previously described with respect to FIGS. 2 through 5 . Initially, in step 450 the handset is in WiFi mode and is actively engaged in sending and receiving VoIP traffic. During this active state, in step 455 the handset periodically checks the signal strength of the WiFi signal to ensure that the signal remains strong enough to maintain the VoIP traffic. If the signal strength is not too low, the process returns to step 450 and the handset remains in WiFi mode processing VoIP traffic. If, as determined in step 455 , the WiFi signal is too low, the handset hands off the call to the CDMA mode, as shown in step 460 . If the hand off was successful, as determined in step 465 , then the voice traffic transitions over to the CDMA mode in step 470 . Alternatively, if the handoff was not successful then the handset returns to the CDMA enabled ready state in step 475 , where it is available for CDMA traffic.
[0045] FIG. 8 is a flow diagram illustrating an example process for acquiring a second air interface connection when no first air interface signal is available according to an embodiment of the present invention. The illustrated process may be carried out in various embodiments by dual mode handsets such as those previously described with respect to FIGS. 2 through 5 . Initially, in step 500 the handset attempts to acquire the CDMA signal. If, as determined in step 505 , the CDMA acquisition is successful, then the handset moves into the state where it is CDMA enabled and available for CDMA traffic, as shown in step 510 .
[0046] However, if the CDMA acquisition is not successful, then in step 515 the handset checks to see if it is configured and authorized (or instructed, e.g., by the setting of a system parameter or preference) to enable WiFi. If not, then in step 520 the handset determines if it has reached the maximum number of retry attempts for CDMA acquisition. If it has not reached the maximum number, the handset returns to step 500 where it attempts to acquire the CDMA signal again and the process continues. If the maximum number of retry attempts has been reached, then in step 525 the handset goes into low power mode in order to conserve resources while it is unable to acquire a signal.
[0047] If the handset determines in step 515 that it should enabled WiFi, then in step 530 the handset attempts to acquire the WiFi signal. If the signal is successfully acquired, as determined in step 535 , then in step 540 the handset moves into the WiFi enabled state and it is available for WiFi traffic such as VoIP calls. If the signal was not acquired, then in step 545 the handset determines if it has reached the maximum number of retry attempts for WiFi acquisition. If it has not reached the maximum number, the handset returns to step 530 where it attempts to acquire the WiFi signal again and the process continues from there. If, however, the maximum number of retry attempts has been reached, then the handset goes into low power mode in step 525 in order to conserve resources while it is unable to acquire a signal.
[0048] In one embodiment, depending on the preferences or other configuration parameters of the handset, when it is in low power mode the handset may periodically attempt to acquire the CDMA signal by resetting the maximum number of retry attempts for CDMA acquisition to zero and returning to step 500 . Alternatively, the handset may reset the maximum number of retry attempts for WiFi acquisition to zero and return to step 530 .
[0049] It should be noted that those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and method steps described in connection with the above described figures and the embodiments disclosed herein can often be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled persons can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the invention. In addition, the grouping of functions within a module, block, circuit or step is for ease of description. Specific functions or steps can be moved from one module, block or circuit to another without departing from the invention.
[0050] Moreover, the various illustrative logical blocks, modules, and methods described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (“DSP”), an ASIC, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
[0051] Additionally, the steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium including a network storage medium. An exemplary storage medium can be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can also reside in an ASIC.
[0052] The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly limited by nothing other than the appended claims. | Alternative software architectures for a dual mode wireless communication device and methods of use are provided for efficient and effective use of the processor and memory capabilities of first and second air interface processors on a dual mode wireless communication device. The alternative architectures efficiently distribute a plurality of operational modules across the processors for efficient dual mode operation of a dual mode wireless communication device. Procedures for transitioning into a second air interface mode from a first air interface mode and vice versa are also disclosed. These seamless transitions can be based on user preferences and/or real time environmental variables such as signal strength or availability. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation of co-pending U.S. patent application Ser. No. 11/691,353, filed on Mar. 26, 2007, entitled “Meta-Application Architecture For Integrating Photo-Service Websites For Browser-Enabled Devices,” now U.S. Pat. No. ______, which is a Continuation of co-pending U.S. patent application Ser. No. 09/752,082, filed on Dec. 29, 2000, also entitled “Meta-Application Architecture For Integrating Photo-Service Websites For Browser-Enabled Devices,” now U.S. Pat. No. 7,197,531, each of which is commonly owned with this application and herein incorporated by reference. The present invention is also related to co-pending U.S. patent application Ser. No. 09/698,777, entitled “Meta-Application Architecture For Integrating Photo-Service Websites,” filed on Oct. 27, 2000, now U.S. Pat. No. 6,453,361, commonly owned with this application and herein incorporated by reference.
FIELD OF INVENTION
[0002] The present invention relates to manipulating digital images over the Internet, and more particularly to providing an architecture for integrating photo-service-based websites for access by client devices.
BACKGROUND
[0003] As the popularity of digital cameras grows, the desire of digital camera users to share their images with others will also continue to grow. The best approaches to photo-sharing take advantage of the Internet. Several Internet companies now offer an even more convenient approach by providing photo-sharing websites that allow users to store their images for free and to arrange the images into web-based photo albums. Once posted on a photo-sharing website, others may view the images over the Internet.
[0004] The assignee of the present invention has developed a system for uploading images to the Internet, directly from the camera, as described in U.S. Pat. No. 6,636,259 entitled “Automatically Configuring A Web-Enabled Digital Camera To Access The Internet” issued Oct. 21, 2003.
[0005] In this system, cameras connect to a gateway server on the Internet via a service provider, which may include a wireless carrier and/or an Internet service provider (ISP). In order to create a camera that requires no configuration to connect to the Internet, the camera is provided with a software application that is pre-configured to establish communication with the ISP and the gateway server. Upon establishing a connection, the camera sends the user's account ID and password to the gateway server. The user account information is then stored on the camera for use the next time the electronic device accesses the website. Thus, the user does not have to enter account information in order to establish the ISP connection or the website account before accessing the Internet.
[0006] The gateway performs two basic services for the client. First, it is the camera's home base, which provides authentication services (user and device) and configuration services (it updates the camera's configuration, so the user doesn't have to). Second, it receives and responds to the camera application's requests using a protocol both understand. Services available to a camera may include the ability to send images from the camera to a specific photo-service service and the ability to send emails with links to uploaded images.
[0007] The current gateway solution is built on traditional client-server architecture, where a software application on the camera communicates with a software application on the server. Client-server architecture requires custom software on all three tiers of the current architecture; the camera, the gateway, and the photo-service site. In addition, the current gateway solution only enables communication with digital cameras, not other mobile devices.
[0008] A newer model for application deployment on the Internet today is server-based (i.e., ASP model), where a client device equipped with a web browser communicates with a web server. Browser-based devices simply download web pages from the server, which provides the application function and data. The deployment of web applications using this new server-based architecture is growing much faster than the deployment of client-server based applications because browser-based clients do not require a gateway that “speaks” the client application's protocol. Thus, browser-based clients may connect to the photo-service sites directly, since the devices are browser-based. In addition, browser-based clients also do not require embedded custom software for requesting imaging services from the photo-service sites. Instead, once connected, users of these devices could interact with the photo-services sites directly using the device's browser to display web applications from the photo-service sites if the sites support the specific browsers in these devices, or indirectly via a transcoding gateway.
[0009] A transcoding gateway converts the sites' HTML to a format suitable for the various browser types. Transcoding products exist today that can support multiple browser-based clients that are both wireless and wired. Transcoding technology takes a formatted input stream (typically HTML) from a web server and converts it to an output stream in another format (e.g., WML for WAP phones, cHTML for i-mode phones, etc) of a particular type of browser-based device. Digital cameras will soon be equipped with browsers, just as PDA's and cellphones are, and such transcoding products allow, or soon will allow, browser-based devices to access the images and image services of photo-services sites.
[0010] There are two main problems with equipping digital cameras with web browsers for communication with photo-service sites and for running their web applications. One problem is making the presentation of the web applications palatable to the various types of browser-based devices, given the variety of display characteristics and browser technologies. There are two approaches to addressing this presentation problem.
[0011] One approach is for each photo-service site to build custom web pages for each specific device/browser type. That is, the photo-service site would need to provide web pages formatted in HTML, WML, cHTML, and so on, and preprocess images to suit the device display capabilities. This is both labor intensive to initially setup and difficult to maintain as changes are made to the site's data and services.
[0012] A second approach is to use a transcoding product, such as a WAP gateway or Oracle's Portal-to-Go. The problem with the transcoder approach is that it tries to solve a very broad problem, making all HTML encoded information presentable in a number of other different formats. Consequently, transcoders often produce unsatisfactory results. Transcoders thus serve as a temporary solution while photo-service sites build support for each of the various devices directly into their sites.
[0013] As digital imaging grows in popularity, there will be a need for disparate photo-service sites to integrate their offerings (e.g., photo-hosting from one, and printing from another). This requires that two photo sites wishing to become partners must each enable their sites to communicate. Neither of the two approaches described above addresses the requirement of integrating the services that span the sites of multiple photo-service providers. Since there is no standard for inter-site communication for photo-service sites, this effort must be undertaken for each new partner a site agrees to work with.
[0014] The second problem with equipping digital cameras with web browsers for displaying web applications from photo-service sites is the limitations inherent in web browsers, which is that browsers typically do not allow web applications to have access to content of the requesting device. Using a PC environment as an example, assume a user wants to upload images to a photo-sharing site on the Internet using a browser. To upload images, the user navigates to the photo sharing site and clicks an “upload” button. In response, the photo sharing site sends an upload web page to the user's PC. Because the web browser does not allow the upload web page to access to the hard drive, the upload page displays several blank image name fields for the user to fill-in. If the user does not know the names of the images, the user must click a “browse” button on the web page in order to search the directories on the PC for the desired image files. Once the user navigates to the correct directory and selects one of the images files, the name of the image file is then inserted into one of the image name fields on the web page. The process is then repeated for each image the user wants to have uploaded.
[0015] Due to limitations imposed by web browsers on web applications with respect to the ability to access the internal storage of the requesting device, the process of manipulating images over the Internet via web browsers is burdensome and inefficient.
[0016] Accordingly, what is needed is a method and system for integrating web photo-services for browser-enabled client devices. The present invention addresses such a need.
SUMMARY OF THE INVENTION
[0017] The present invention provides a method and system for integrating web photo-services for a browser-enabled device. The method and system include providing a server that communicates with the device over a network, and associating images stored on at least one photo-service site with a user account. Thereafter, an inventory of images stored on the device is received from the device, and an image-related web application is provided to the device over the network, where the web application requires access to the user's images. The method and system further include providing a list of the images associated with a user's account to the web application, wherein the list of images includes an image reference for each image and an indication of whether each image is stored on the device or on the photo-service site, such that the web application may perform at least one function on the user's images regardless of where the images are stored.
[0018] According to the present invention, the function of the web application is extended by allowing the web application to have access to references to the user's images, but not to the images themselves. Thus, the present invention overcomes the limitations imposed on the web application by the web browser and allows the web application to make intelligent decisions about what functions to perform on the user's images regardless of the images' storage locations.
DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a block diagram illustrating a meta-application architecture for an online system in accordance with a preferred embodiment of the present invention.
[0020] FIGS. 2A and 2B are a flow chart illustrating a process for allowing a web application to access image files stored on both a client device and distributed across remote locations in a preferred embodiment of the present invention.
[0021] FIG. 3 is a diagram illustrating an example image list sent from the gateway server to the web application contracting with the browser of the client device.
[0022] FIG. 4 is a flow chart illustrating the process of uploading images from a web-enabled client device using a web application that is accessed through the image gateway in accordance with a preferred amount of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention relates to an online digital imaging architecture. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features described herein.
[0024] The present invention provides a meta-application architecture for allowing photo-service websites to receive and send images to and from a wide range of client device types, and for integrating the services of the photo-service sites 14 for access by users of the client devices. The present invention also allows web applications running in a web browser on the client devices to access all of the user's image files regardless of whether the image files are stored on the client device or on sites on the Internet, thereby enhancing imaging services provided to the client devices.
[0025] FIG. 1 is a block diagram illustrating a meta-application architecture for an online system 10 in accordance with a preferred embodiment of the present invention. The system 10 includes multiple client devices 12 that request imaging services from multiple online photo-service sites 14 . The photo-service sites 14 are sites on the Internet that provide different types of digital imaging services. For example, one photo-service site 14 may provide an image hosting service, while another photo-service site 14 provides image printing services, for instance.
[0026] A client device 12 refers to an electronic device capable of capturing and/or displaying digital images and communicating over a network, such as the Internet. Such electronic devices include devices that store digital images, such as PCs and photo kiosks, and image capture devices such as digital cameras and PDAs, and cellphones that have lens attachments, for example. In a preferred embodiment, the client devices 12 are browser-based, although non-browser-based devices may also be supported. The client devices 12 communicate over the Internet via a wireless, or wired connection, but because they incorporate different browser types, the client devices 12 communicate data in different formats. For example, some client devices 12 such as PCs may communicate data in HTML format. Other client devices 12 such as cellphones, may use data formats such as Wireless Markup Language (WML), which is a streamlined version of HTML for small screen displays, cHTML which is a subset of HTML, and Handheld Device Markup Language (HDML), for instance.
[0027] In one embodiment, the client devices 12 connect to the Internet via a service provider 16 , which may include a wireless carrier and/or an Internet service provider (ISP). Once connected to the Internet, the client devices 12 have the capability of uploading the digital images to the online photo-service sites 14 for storage and/or for receiving digital images from the photo-service sites 14 for display.
[0028] One aspect of the present invention provides a meta-application 22 architecture that provides a common communication framework for integrating photo-service sites 14 and services for client devices 12 . The meta-application architecture includes a site on the Internet, referred to as the image gateway 18 , that interfaces between the client devices 12 and the photo-service sites 14 . In a preferred embodiment, the image gateway 18 includes a gateway server 20 , a software meta-application 22 , and a set of site adapter software 24 that provide a set of standard APIs and data formats that the photo-service sites 14 use so that the image gateway 18 can present data and services from the sites 14 to the various client devices 12 . These same APIs and data formats allow the image gateway 18 to present the services of multiple photo-services 14 in one integrated application, and allow communication among the photo-services sites 14 . For example, the image gateway 18 enables a user with images stored on one photo-host site to access to the services of all print service providers who also use the image gateway 18 . The photo-hosting site 14 would not need to make any special effort in order to work with the print service providers since they are all bound together by the meta-application.
[0029] The gateway server 20 performs the function of a web server, while the meta-application 22 performs the function of an application server. The meta-application 22 may reside on the same or different computer from the gateway server 20 , and one of the photo-service sites may be part of the image gateway 18 . The gateway server 20 provides client device 12 connectivity and is primarily responsible for detecting the client device 12 type and its browser type and display characteristics. The gateway server 20 may also provide security, configuration, and administration services, including the collection of usage statistics.
[0030] In a preferred embodiment, the gateway server 20 passes the data and service requests of the client devices 12 and from the meta-application 22 in a device independent fashion.
[0031] One reason that there is no standard for communication between photo-service sites 14 is because each photo-service site 14 represents its own data and services in different formats. For example, all photo-hosting web sites 14 organize a user's images in a nested tree-like structure similar to a file directory, but the names of the nodes in these trees vary across sites. For instance, some of the terms used include “album,” “pholio,” “page,” and “shelves”.
[0032] According to the present invention, the meta-application 22 abstracts the underlying data model and the function provided by the photo-service sites 14 , which is common across the photo-service sites 14 , to define a common data model format for the data, referred to here as a meta photo-service model. In a preferred embodiment, the meta photo-service model is implemented using XML.
[0033] Since each photo-service site 14 may use its own data model and define its own API or protocol for accessing the site's functionality, respective site adapters 24 are used to convert between the data and service formats of each photo-service site 14 and the meta photo-service model 26 .
[0034] In a preferred embodiment, the image gateway 18 is provided with a database 32 for supporting the aggregation of data and services across the various photo-service sites 14 . This enables the image gateway 18 to support a single login for a particular client device 12 and enables data sharing, such as billing information, across photo-service sites 14 . This data sharing eliminates the need for users to reenter this information for each site, but requires that the database 32 be synchronized with the data stored on the photo serving sites.
[0035] According to a further aspect of the present invention, developers who have registered with the image gateway 18 may post web applications 42 on the image gateway 18 for access by the client devices 12 . In a preferred embodiment, the web applications 42 are imaging related and allow the users of the client devices 12 to manipulate their images in some manner. Examples of such imaging-related web applications 42 that may be provided include an upload image application that uploads images from the client device 12 to a photo-hosting service 14 via the image gateway 18 , and a search application that searches for the user's images, for instance.
[0036] It should be noted that although the terms images as used herein includes media types such as still images, burst images, and time lapse images, the term images also encompasses media types such as movies, sound annotations, animations, and clip art, for instance.
[0037] In a preferred environment, the web applications 42 are implemented as server-side processes that allow web pages to interact with databases and other applications. Examples of such server-side processes include active server pages (ASPs), CGI scripts and JavaServer Pages (JSPs), which are web pages that contains HTML and embedded programming code that is executed by a server. When a web browser makes a request from the web application 42 for a web page, the server executes the embedded program, and the HTML provides the page layout that will be returned to the web browser. The programming code provides the processing for the page, such as delivering search data entered on a web page to the database for lookup. It would also format the results of that search as HTML and send it back to the client device 12 for display.
[0038] When a user attempts to work with his or her images on the browser-enabled client device 12 using one of the web applications 42 , the user's images may be stored in one of three ways; 1) on the client device 12 , 2) on one or more photo-service sites 14 , or 3) on both the client device 12 and one or more photo-service sites 14 .
[0039] Displaying the user's images on the client device 12 using a conventional browser may be accomplished in one of two ways. First, the images stored locally on the client device 12 could be displayed by storing an HTML page that references those images in the device 12 and then opening the HTML page in the web browser. Second, the images that are stored on a web server could be displayed by the web server by sending an HTML page referencing those images to the web browser on the device 12 . Where the conventional browser fails is where the HTML page is being sent from the server to the device 12 , but the image files that need to be referenced are stored on the client device 12 . Thus, if the web application 42 needs to access images stored both in the device 12 and on the server, a problem arises because the browser on the client device 12 will typically not allow the web application 42 access to the contents of the client device 12 . In addition, the web application 42 would have no way of knowing about the user's images that are stored on other photo-service sites 14 .
[0040] Besides providing a method for integrating web photo-services for a browser-enabled device, the present invention also allows a web application 42 sent from one server to know about files stored in locations other than that server. More specifically, the meta-application architecture of the present invention provides web applications 42 (under strict control and security) access to the user's images, which may be stored both locally on the client device 12 and distributed across photo-service sites 14 .
[0041] FIGS. 2A and 2B are a flow chart illustrating a process for allowing a web application 42 to access image files stored on both a client device and distributed across remote locations in a preferred embodiment of the present invention. The process begins by providing a gateway server 20 that communicates with the client device 12 and associates images from the client device 12 with a user account in step 100 . As described above, the user's previously uploaded images may be distributed across various photo-service sites 14 .
[0042] The client device 12 is also provided with software that is capable of reporting the image contents of the device to the gateway server 20 in step 102 . The software may report the image contents of the device either automatically, or at the request of the user or the image gateway 18 . In a preferred enlightenment of the present invention, the software that reports the image contents to the gateway server 20 is a customized web browser. In an alternative embodiment, the underlying software in the client device 12 that establishes the connection to the gateway server 20 is responsible for reporting the images in the client device 12 to the gateway server 20 . In the second embodiment, the browser itself need not know about the images directly, but only through references provided via downloaded pages from the gateway server 20 .
[0043] Once communication between the client device 12 and the image gateway 18 has been established, the client device displays a web page from the gateway server 20 indicating what web applications 42 are available to user in step 104 . In a preferred environment, the available web applications 42 are displayed via hyperlinks. For example, the web page displayed to the user may display links such as “Upload Images,” and “Search For Images,” which link to corresponding web applications 42 .
[0044] In response to the user selecting a web application, the gateway server 20 connects the client device with the selected web application 42 in step 106 . Those with ordinary skill in the art will appreciate that the connection is preferably established with a secure handshake mechanism.
[0045] When the web browser in the client device 12 begins interacting with the web application 42 , the web application 42 sends a request to the gateway server 20 asking what images are available for the user in step 108 . In a preferred embodiment, the web application 42 identifies the user to the gateway server 20 using the user account or user ID, which was provided to the web application 42 when the connection was made to the application 42 by the gateway server 20 . In response, the gateway server 20 prepares and returns a list of image references and other information corresponding to the user's images in step 110 .
[0046] FIG. 3 is a diagram illustrating an example image list 50 sent from the gateway server 20 to the selected web application 42 interacting with the browser 54 on the client device 12 through the gateway server 20 . In a preferred embodiment, the image references in the list 50 comprise image identifiers (IDs) 56 that uniquely identify each image. The image IDs 56 may comprise a number or a name, or an internal disk reference (e.g., file path). The information included in the list may include the location 58 of each image (e.g., the device or a server), and may even include information about which server. The information may also include metadata 60 corresponding to each image. The metadata 60 is data associated with an image that is either embedded within the image file or separately in a file or database. Examples of metadata 60 include values for parameters such as f-stop, zoom factor, focus distance, category tags, image name, camera manufacturer and model number, and so on. Specific metadata may be requested by the web application to be included in the list, including custom user metadata.
[0047] According to the present invention, the web application 42 interacting with the browser on the client device 12 is not given access directly to the user's images, instead the web application 42 is only given access to information about the images via the image list 50 . The information in the list 50 returned to the web application 42 is sufficient to allow the web application 42 to sort and select the images to carry out its function.
[0048] Referring again to FIGS. 2A and 2B , after receiving the image list 50 , the web application 42 selects a set of images to reference for display and/or to perform a function on in step 112 . As shown in FIG. 3 , the web application 42 places these references in web pages that are returned to the device browser 54 through the gateway server 20 .
[0049] Referring again to FIG. 2B , for images that are identified in the list 50 as being stored locally on the client device 12 in step 114 , the web application 42 generates a reference that comprises a file path or other pointer to the image in the client device 12 along with a resize command in step 116 . Preferably, this translation from image ID to the file path is performed by the gateway server 20 when the web page containing the ID passes through on its way from the web application 42 to the client device 12 .
[0050] For images that are identified in the list 50 as being stored on a photo-service site 14 or other server in step 118 , the web application 42 makes a request for the image from the gateway server 20 using the image ID in step 120 . The gateway server 20 then fetches the image from the indicated location, resizes and converts the image to the required format, and passes a URL to the resulting resized image file back to the web application 42 in step 122 . The web application 42 then inserts this URL into to the web page that is transmitted to the device browser 54 in step 124 . Alternatively, the translation from image ID to a URL to a resized, converted image file is performed at the gateway server 20 when the web page containing the ID passes through on its way from the web application 42 to the client 12 . For image viewing, there is no actual requirement for the web application 42 to have a copy of the image or images being displayed on the client device 12 .
[0051] The entire viewing function can be done with image references, along with appropriate gateway functions and browser requests for local files. However, when a web application 42 wishes to perform an operation on an image, such as color balance, contrast enhancement, rotate, etc., an actual copy of the image is required at the web application 42 . Thus, the web application can request a copy of the image from the gateway server 20 in any resolution up to full image resolution. In this case, the web application 42 will perform whatever function desired, and create any versions of the image, such as thumbnails, within its own file system for reference by the browser 54 . The modified images can be temporary or permanent. For permanent images, the web application 42 must request that the gateway server 20 store the resulting image in an appropriate location, depending on the user's account information.
[0052] The web application 42 may also need to delete images selected by the user. For example, if a modification is performed, and the user wants to keep the modification and not the original, a delete function is required. If images are uploaded from the client device 12 to a photo hosting/sharing service, the user may wish the copies in the device 12 be deleted, thus eliminating duplicate storage. However, allowing the web application 42 to delete images is a dangerous practice. It is assumed that all destructive operations are carried out over secure connections to prevent unauthorized access, but even with this protection, additional security protection is required.
[0053] The preferred embodiment is for the delete function to be handled by the gateway server 20 . In this case, any image delete functions must be requested by the web application 42 . The gateway server 20 would be responsible for issuing the appropriate warning to the user via the browser 54 or its underlying software. Additionally, the gateway server 20 may cache copies of all deleted files for a period of time or until the user “empties the trash,” thus preventing the user from accidentally destroying valuable images. This is especially true for deletes of original images when image modifications are done. It is good practice to never delete the original image, and carry modifications via additional files.
[0054] The present invention will now be explained by way of a particular example where the web application 42 provides an image upload function for the user of the browser-enabled client device 12 .
[0055] FIG. 4 is a flow chart illustrating the process of uploading images from a web-enabled client device 12 using a web application 42 that is accessed through the image gateway 20 in accordance with a preferred embodiment of the present invention. During normal operation of the client device 12 , the user may be shown a homepage of the image gateway 20 , which displays a selection of image-related functions the user may want to use in step 200 . In response to user selecting the choice to upload images to a photo-service site 14 , the gateway server 20 connects the client device 12 to a corresponding upload web application 42 in step 202 . The gateway server also provides the upload web application 42 with the image list 50 identifying the user's images in step 204 . As described above, the image list 50 will identify both images present in the client device 12 as well as images stored on the client device and the image gateway 18 and other photo service sites 14 .
[0056] The upload web application 42 will then automatically select images stored on the client device from the image list 50 and present corresponding thumbnail images to the client browser via HTML tags in step 206 . In a preferred environment, the HTML tags incorporate the image IDs and/or file paths from the image list 50 and may also include height and width tags for resizing the original image into the thumbnail image.
[0057] The browser 54 on the client device 12 then interprets the HTML and renders the images presented by the web application 42 (resizing the original images if necessary) in step 208 . Since the images are local, no web traffic is required to service the image tags—they are accessed locally and resized locally. The web applications 52 allows the user to select which of the displayed images to upload in step 210 . In response, the web application 42 uploads the selected images to the gateway server 20 in step 212 , where they are then transmitted on to the selected photo-service site 14
[0058] After successful completion of the upload, the web application 42 may ask the user if the device resident copies of the uploaded images should be deleted. If the user selects YES, a request for deletion is issued by the web application 42 to the gateway sever 20 . The gateway server 20 performs the appropriate deletion function, typically including getting confirmation from the user before proceeding. The confirmation may come from the gateway server 20 , or may come from underlying software in the client device 20 , which is designed to intercept any delete requests from the browser or internet connection.
[0059] As a further example, assume that a developer provides a search web application 42 , which when run on the browser 54 of the client device 12 allows the user to enter search criteria, and in response, the search web application 42 returns and displays a set of images meeting those criteria. In operation, the gateway server 20 would provide the web application 42 with a list 50 of the user's images. As described above, the image list 50 would include for each image an image ID 56 , the location 58 of the image, and any metadata 60 associated with the image. The metadata 60 could be specifically requested, based on the user criteria. The web application 42 would then use this information to find the images matching the user's search criteria. For the found images that are stored in locations other than the client device 12 , the web application 42 would request that the gateway server 20 fetch, resize, and convert these images for access by the browser 54 in the client device 12 . The web application 42 would thus combine the images found on the client device 12 with the images transmitted from the gateway server 20 and display them to the user through the browser 54 .
[0060] According to the present invention, the meta-application architecture provides a service that extends the functionality of web applications 52 that function through the browser on the client device. Image-related web applications 52 can now operate on all of a user's images without regard to where the images are stored and can make intelligent services available to the user. The intelligence for handling where the images are located and what to do with the images to make them display in the client device 12 is performed by the image gateway 18 for the web application 42 . Since most photo-service sites 14 today do not have the ability to interact directly over the Internet with client devices 12 , the present invention provides a service that allows an interface designed for the LCD screen of the client device 12 to access the photo-service sites 14 that don't have that capability, and brings all the user's images under one service and one access point.
[0061] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | A method and system for integrating web photo-services for a browser-enabled device is disclosed. The method and system include providing a server that communicates with a browser-enabled device over a network. Further, an image-related web application is provided to the device over the network, the web application executable on the device. The web application receives a list of images stored on the device from the device and a list of images stored at a remote location from the server. The method and system further include providing, by the web application, content combining the lists of images received from the device and the server, wherein the content is presentable on the device and includes an image reference for each image included in the combined lists of images and an indication of whether each image is stored on the device or at the remote location. | 7 |
FIELD OF THE INVENTION
This invention relates to magnetic locks for movable closures such as doors, gates, or the like, including arrangements for determining the secure or not secure status of the magnetic lock by altering the voltage level to the electromagnet and measuring the counter electromotive force (EMF) induced in the electromagnet.
BACKGROUND OF THE INVENTION
Magnetic locking assemblies are widely used to prevent removal or relative motion between parts. For example, such assemblies may be used as locks to secure movable closures such as doors, gates, or the like. Magnetic locking assemblies are also commonly used as magnetic fasteners, mounting structures, lifters, couplings, theft protection contrivances, and the like. To secure a door, a typical electromagnetic lock includes an electromagnet body mounted on a door frame, and a ferrous metal armature plate mounted on the door. When energized, the electromagnet generates a sufficient magnetic attractive force to firmly hold the armature plate and the door against the electromagnet. This energized condition defines a locked condition. The door may be conveniently unlocked by switching off the electrical current to the electromagnet by any one of a number of devices such as a digital keypad or a card reader.
Two requirements should be met for an electromagnetic lock to properly secure a door. First, the electromagnetic lock should be sufficiently energized to generate a holding force adequate to prevent a forced opening of the door. Secondly, the electromagnet should be properly mated to the armature plate. The electromagnetic lock is considered “locked” when these two requirements are met.
To enhance security within a facility equipped with an electromagnetically locked door, the status of the door and/or electromagnetic lock can be monitored by one or more devices which define part of the building security system and which are tied into the building security system wiring. Door status (whether the door is opened or closed) is very commonly detected by magnetic contacts mounted on the door. These magnetic contacts change state as the door opens and closes. Electromechanical plunger switches can also perform the function of detecting door status. Higher order security information, however, is provided by various methods of detecting whether the electromagnetic lock is securing the door. Although the door may be closed, this does not necessarily mean that the door is properly secured. The facility therefore has a clear interest in detecting that the door is secured rather than merely closed. Accordingly, prior art electromagnetic locks have included lock status detection system to provide this important information to the building security system.
In facilities where a high level of security must be maintained, such as a prison or bank, it can be expected that intruders and saboteurs will attempt to defeat the magnetically locked door without alerting the building security system. Prior art magnetic lock status detection systems have weaknesses when they are employed in higher security facilities in that they are relatively easy to defeat. Several devices are currently available to determine the lock status of electromagnetic locks. However, each of the prior art has associated shortcomings.
One attempt to satisfy the needs discussed above is disclosed in U.S. Pat. No. 4,287,512 issued to Combs. Combs teaches mounting a Hall-effect device within the magnetic lock adjacent to the magnetic core. The Hall-effect device is able to detect varying intensities of a magnetic field. The field adjacent to the magnetic core will be more intense when the lock is not secured, i.e., when the electromagnet is not coupled with an armature plate. When the electromagnetic lock is secure, the magnetic field from the electromagnetic core is directed into the armature plate, thus diminishing the intensity of the magnetic field at the point at which the Hall-effect device is positioned.
A similar method found in commercially available products replaces the Hall-effect device with a magnetic reed switch which is also able to detect an alteration in the magnetic field intensity adjacent to the core of the electromagnet.
The monitoring systems utilizing a Hall-effect device (as disclosed in Combs) or a magnetic reed switch may also be defeated. The Hall-effect device or the reed switch is generally positioned at one end of the magnetic core. In the event that an intruder places an object creating an air gap at the other end of the electromagnetic lock, the armature can be made to tilt away from the magnet body at this other end. The resultant air gap is sufficient to reduce the holding force of the electromagnetic lock to the point where it is not secure. However, since the armature plate rests against the core at the end where the Hall-effect device or reed switch is mounted, the magnetic field is still diverted into the armature at that point, and the status detection system is, thereby, defeated. This method of defeating the monitoring system may be counteracted by mounting multiple Hall-effect devices or magnetic reed switches around the periphery of the magnetic core, but this increases the cost and complexity of the system.
Another effective method of defeating the monitoring system disclosed in Combs is the introduction of a powerful permanent magnet to the outside of the electromagnet body. The localized interaction of the permanent magnet's magnetic field can be positioned so as to null the electromagnetic field when it increases in intensity owing to the decoupling of the electromagnet body from the armature plate. In this event, the status detection circuit will continuously report secure even when the door is fully opened.
In addition to being vulnerable to the defeating methods described above, the monitoring systems disclosed in Combs and the magnetic reed switch techniques also have incorporated with it issues of sensitivity. The Hall-effect device or magnetic reed switch must be carefully positioned in controlled proximity to the magnetic core in order to reliably detect the secure status of the electromagnetic lock. The positioning cannot be allowed to shift with time, so the Hall-effect device or magnetic reed switch is generally secured by permanently potting the core in a material such as epoxy. Thus, the Hall-effect device or magnetic reed switch is usually unrepairable. In the event of failure of this component, the entire electromagnet assembly must be replaced. This also creates the commercial disadvantage of two different models of electromagnetic lock being offered: one with status detection and one without.
Reference is also made to U.S. Pat. No. 4,516,114 issued to Cook in which the magnetic core of the electromagnet acts as a status detection switch. The core is divided into three segments. When the armature is pulled strongly down against the core by the power of the electromagnetic field, a circuit is closed between the armature plate itself and the two isolated segments of the core. This circuit closure is employed to detect and report to the building security system that the electromagnetic lock is holding secure.
The status detection system disclosed in Cook may be defeated by placing a nonferrous, but electrically conductive material between the armature plate and the electromagnet body such as a thin aluminum plate or aluminum foil. With the door closed, a circuit would be closed between the two segments of the magnetic core and the intervening aluminum plate or foil which is being pressed against the magnetic core by the armature plate. The building security system would read the lock as secure. However, the intervening aluminum creates an air gap sufficiently large to substantially reduce the holding power the electromagnetic lock. For example, an air gap of 0.015 inch may allow an intruder to easily push the door open.
Accordingly, a need exists for an improved magnetic lock status detection method which will be resistant to tampering.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a security device for securing a closure that is movable within a support frame from a secured position to an unsecured position and back is provided. In general, the closure is secured through the use of an electromagnetic lock and status detection system. In the exemplary embodiment, the magnetic armature plate is mounted on a door, and an electromagnet is mounted onto a support frame of the door.
When a ferrous body such as the armature of a door is brought into proximity with the electromagnet, the magnetic field is concentrated, and the inductance of the electromagnet coil is increased. Thus, the inductance of the electromagnet is indicative of door status. A relatively low inductance means that no armature is near the coil of the electromagnet, i.e., that the door is open. A relatively high inductance means that the armature plate properly abuts the electromagnet, thus indicating that the door is fully closed and secured. The inductance of the electromagnet is one component of its reactance. Thus, whether the armature is closely and properly coupled to the electromagnet can be detected by sensing a reactive response characteristic of the electromagnet.
In a preferred embodiment of the present invention, a status detection unit according to the present invention is placed in series between an electromagnet power supply and the respective plus and minus leads of the electromagnet. At periodic intervals the status detection unit switches off the power to the electromagnet for a short period of time. The power to the electromagnet is switched off about once every two minutes for about 15 milliseconds (ms). The holding force of the door is not significantly decreased when the power is switched off due to the magnetic inertia of the electromagnet. During the 15 milliseconds, the collapsing magnetic field induces a counter electromotive force (EMF) in a coil of the electromagnet which, together with the electromagnet core and the armature if an armature is present, has an appreciable inductance. At the moment just prior to restoring power to the electromagnet, the status detection unit measures the counter EMF induced in the coil. Because the counter EMF detected at the 15 ms time point is a function of the inductance of the coil and hence is a function of how close the armature is to the electromagnet, measuring the counter EMF at the 15 ms point provides an indication of whether the door is fully closed and properly secured, whether the door is fully open and unsecured, or whether the door is closed and unsecured. The door may be closed and unsecured when a small gap air gap exists between the electromagnet and the armature.
Other objects, features, and advantages of the present invention will become apparent from a consideration of the following detailed description and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electromagnetic lock and status detection system used to secure a door in accordance with the present invention;
FIG. 2 is a close up perspective view of the electromagnetic lock and status detection system shown in FIG. 1;
FIG. 3 is a schematic circuit diagram of the status detection unit shown in FIG. 2; and
FIG. 4 is a graph illustrating the decay rates of the counter electromotive force depending on the lock status of the electromagnetic lock shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to an electromagnetic lock and status detection system. The lock and detection system is suited to prevent removal or relative motion between parts. In the particular embodiment shown in the drawings and herein described, the lock and detection system is designed to secure a door. However, it should be understood that the principles of the present invention are equally applicable to virtually any lock and detection system which prevents removal or relative motion between parts. Therefore, it is not intended to limit the principles of the present invention to the specific embodiment shown and such principles should be broadly construed.
Referring to FIG. 1, an electromagnetic lock and status detection system 10 is configured to secure a door 12 . The lock and detection system 10 includes an electromagnet 14 and an armature plate 16 . The electromagnet 14 is suspended under a door frame 18 , and the armature plate 16 is mounted on the door 12 . When the door 12 is closed, the armature plate 16 contacts the electromagnet 14 and secures the door 12 .
Referring now to FIG. 2, an enlarged view of the lock and detection system 10 is shown to further include a status detection unit 20 and an electromagnet power supply 22 coupled to the electromagnet 14 . The electromagnet 14 has an electromagnetic core 24 which magnetically couples with the armature plate 16 . The status detection unit 20 includes a circuit board 26 . The circuit board 26 is operatively connected between the power supply 22 and the electromagnet 14 by power lines 28 , 30 , 32 , 34 . The power supply 22 converts the building line voltage to an appropriate DC voltage of either 12 or 24 volts. It is noted that any appropriate voltage other than 12 or 24 volts may be used as long as the electromagnet is properly energized. Furthermore, a battery may be used to energize the electromagnet and power the status detection unit.
FIG. 3 is a detailed schematic of a preferred embodiment of the electromagnetic lock and status detection system 50 . The system 50 comprises a logic unit 52 , DC bias unit 54 , a first comparator unit 56 , a second comparator unit 58 , a relay unit 60 , and an electromagnet unit (not shown). The LOCK+ and LOCK− signals are connected to power leads 32 and 34 of electromagnet 14 .
Input power (shown as “V”) from a power supply is connected to several points in the schematic shown in FIG. 3 . In operation, when power is first applied to the system 50 , a voltage regulator 62 powers up a microprocessor 64 . The microprocessor 64 then begins to execute its stored program and immediately turns on the electromagnet by activating pin P 2 of the microprocessor 64 which turns on a field effect transistor 66 , thereby switching on the electromagnet. The system 50 remains in this state (the electromagnet remaining “on”) for two minutes in the case of the preferred embodiment. Although this dwell time could be set as one would wish in the embedded software of the microprocessor 64 . The relay 68 is also energized when pin P 5 of the microprocessor 64 turns on a bipolar transistor 70 which controls the relay 68 . At the end of two minutes, the microprocessor 64 turns “off” power to the electromagnet for a period of 15 milliseconds. This time period is insufficient for the holding force of the electromagnet to appreciably diminish due to the magnetic inertia of the electromagnet. It is noted that the present invention is not limited to a time period of 15 milliseconds. Depending on the configuration of the electromagnet, the time period may be less than or greater than 15 milliseconds.
At the end of the 15 millisecond time period, the microprocessor 64 repowers the electromagnet. Immediately prior to repowering, the counter EMF has been developed by the partial collapse of the magnetic field. The magnitude of the counter EMF is simultaneously measured by a first operational amplifier 72 and a second operational amplifier 74 , wherein the magnitude of the counter EMF is largely dependent upon the inductance of the electromagnet. The status of the electromagnet can be determined by measuring the counter EMF because holding force is dependent upon the inductance of the electromagnet.
If the counter EMF is less than a level 1 (120 volts for an exemplary embodiment), neither the first operational amplifier 72 nor the second operational amplifier 74 will turn on. This condition will arise when the inductance of the electromagnet is substantially below that which would be expected with a properly coupled armature plate (not shown) or a nearly properly coupled armature plate. In this condition, neither operational amplifier 72 , 74 will turn “on”, and the “off” status of both operational amplifiers 72 , 74 is respectively communicated to the microprocessor 64 via pins P 7 , P 6 . The microprocessor 64 will then determine that the system 50 is not secure and will turn “off” the bipolar transistor 70 . The bipolar transistor 70 will in turn deenergize the relay 68 , and the relay 68 will interface with the building security system to announce a breach of security.
If the counter EMF voltage is greater than the aforementioned level 1, but is less than a level 2 (130 volts in an exemplary embodiment), the first operational amplifier 72 will be “on” and the second operational amplifier 74 will be “off”. This logic condition will be read by the microprocessor 64 as indicating a level of inductance which indicates that the electromagnet is properly coupled to the armature plate. Accordingly, the relay 68 will be left in its energized state and report to the building security system that the electromagnetic lock and status detection system 50 is secured.
In the event that the counter EMF is greater than the aforementioned level 2, a minor obstruction such as a thin piece of paper is present between the armature plate and electromagnet. In this condition, the electromagnet is not secured to the armature plate at the full holding force and the system 50 is considered partially insecure. This logic condition is detected by the microprocessor 64 , and the microprocessor 64 turns off the bipolar transistor 70 so as to de-energize the relay 68 and report to the building security system that the electromagnetic lock and status detection system 50 is not secured.
As long as the electromagnetic lock and status detection system 50 is powered, the embedded program of the microprocessor 64 instructs the system 50 to automatically test the securement status every two minutes. A failure of any test will be immediately reported to the building security system via the output of the relay 68 , and the relay 68 will continue to be held in its deenergized the (system 50 is not secure) condition until a subsequent test indicates that the security of the system 50 has been restored.
The functional relationship between the counter EMF and the locking status of the electromagnetic lock system 10 can be better understood with reference to FIGS. 2 and 4. FIG. 4 graphs counter EMF against time. At time =0 millisecond, the power to the electromagnet 14 is switched “off”. For purposes of clarity, only a portion of the traces 100 , 102 , 104 , 106 are shown. When the electromagnet 14 is deenergized, the counter EMF develops rapidly to a very high peak and then decays at different rates. The different traces 100 , 102 , 104 , 106 are produced by the armature plate 16 being separated by different distances from the electromagnetic core 24 .
As shown in FIG. 4, trace 100 represents a state where inductance is at its lowest value because the armature plate 16 is completely separated from the electromagnetic core 24 . In this instance, the counter EMF declines to zero prior to the 15 millisecond test period, and the counter EMF is read as zero by the operational amplifiers 72 , 74 . Trace 102 illustrates an electromagnet 14 with a large air gap between the electromagnetic core 24 and the armature plate 16 , on the order of about 0.010 inch. Such a large air gap substantially reduces the holding force of the lock system 10 , typically by more than 50 percent. Since the inductance of the electromagnet 14 increases when the separation distance is reduced from a complete separation to a relative large air gap, the counter EMF at the 15 millisecond test period is approximately 90 volts (see trace 102 ). At 90 volts, both operational amplifiers 72 , 74 remain “off” and the lock system 10 reports that the electromagnet 14 is not properly secured to the armature plate 16 .
As shown in FIG. 4, trace 104 represents a state where the lock system 10 is fully coupled and holding at full force. The counter EMF at the detection time of 15 milliseconds is read as 125 volts which is within the “secure” window. When the counter EMF is within the “secure” window range, the first operational amplifier 72 turns “on” and the second operational amplifier 74 remains “off”.
Trace 106 represents a state where a relatively small air gap exists between the electromagnetic core 24 and armature plate 16 such as would be caused by a piece of paper covering a small area of the core/armature interface surface. Although inductance is lower than in the case of trace 104 , the interaction of circuit reactance in this instance delays the decline of counter EMF so that it stands at 150 volts at the measurement time of 15 milliseconds. In this instance, both operational amplifiers 72 , 74 turn “on”, and this logic condition is read as not secure by the microprocessor 64 . It is noted that the position of trace 106 relative to the other traces 100 , 102 , 104 is counter-intuitive. However, an appropriate time and voltage can be determined for any given electromagnetic lock system without undue experimentation by simply measuring the counter EMF as a function of time under the various secured and unsecured conditions. That is, the response characteristics can be empirically determined by simple testing for any given electromagnet and armature combination. Once the reactive response characteristics of the electromagnet and armature have been characterized, an appropriate time to sample the EMF and an appropriate voltage range can be determined, to ensure that the electromagnetic lock is properly secured.
In an alternative embodiment, the status check unit may include a circuit board similar to the circuit illustrated in FIG. 3 with the exception that only a single operational amplifier is used. The electromagnetic lock would be considered secure any time the operational amplifier is turned “on”. In this embodiment, a modest cost savings is achieved, but the security function is lessened. At the 15 millisecond test period, the circuit would only be able to detect a large air gap and would not detect small reductions in holding force. If the measurement time is extended from 15 to 30 milliseconds, for example, detection would become more sensitive. Returning to FIG. 4, trace 104 declines less steeply than trace 106 past the 15 millisecond point so that it reports a higher counter EMF at 30 milliseconds. This can be reliably detected by a single operational amplifier. One of the problems which may be encountered when switching “off” the power to the electromagnet for a 30 millisecond interval is that is that the magnetic inertia is no longer substantially sufficient to keep the door secure, and the door may “pop” open if the secured room is under a positive pressure. Accordingly, the preferred embodiment is cost justified for the majority of applications.
In another embodiment, the input voltage to an electromagnet is reduced (not completely switched “off” as described in the previous embodiments), and an induced counter EMF resulting from the voltage reduction may be measured to determine the status of the electromagnetic lock. Furthermore, the status of the electromagnetic lock may also be determined by increasing input voltage to the electromagnet and measuring the counter EMF resulting from the voltage increase. Still further, in the preferred embodiment described above where power to the electromagnet is switched off, the counter EMF may be measured when power is restored to the electromagnet. The counter EMF values measured in these alternative embodiments may be compared to a determined threshold value to determine whether the lock system is secured or unsecured.
Even more generally, the present invention takes advantage of the fact that the proximity of the armature to the electromagnet causes a change in the reactive response characteristics of the electromagnet. This change in the reactive response characteristics can be sensed using any input voltage which varies according to time, such as switching the current completely off as in the preferred embodiment, or by using a square wave, a sine wave, or any other wave whose DC component is non-zero. The reactive characteristics can also be measured using a variety of techniques, including measuring back EMF as in the preferred embodiment, by measuring the current flow immediately after the input voltage has been increased, or in various other ways that will be apparent to one skilled in the art.
It can be seen that the lock status detection method of the present invention is extremely difficult if not impossible to defeat as it is directly measuring the coupling between the electromagnet and the armature plate by sampling the resultant inductance. If the lock is to be physically defeated, the armature plate needs to be broken loose from the electromagnetic core and this can only occur with a consequent drop in inductance. The methods which are used to defeat the prior art status detention techniques such as inserting obstructions between the electromagnetic core and armature plate and utilizing external permanent magnets will not defeat the present invention.
Although the present invention has been described in detail with reference to the exemplary embodiment and drawings thereof, it should be apparent to those skilled in the art that various adaptations and modifications of the present invention may be accomplished without departing from the spirit and scope of the invention. Accordingly, the invention is not limited to the precise embodiment shown in the drawings and described in detail hereinabove. | An electromagnetic lock and status detection system and method therefor includes an armature, an electromagnet, and a status detection unit. The electromagnet is magnetically attracted to the armature into a mating relationship. A relatively high inductance is established in the electromagnet when the electromagnet is properly mated with the armature, and a relatively low inductance is established in the electromagnet when the electromagnet is not properly mated with armature. The status detection unit is coupled to the electromagnet to monitor the locking strength between the electromagnet and the armature. The unit monitors the locking strength by altering voltage level provided to the electromagnet and measuring the counter EMF induced in the electromagnet. | 4 |
BACKGROUND OF THE PRESENT INVENTION
[0001] 1. Field of the Present Invention
[0002] The present invention relates to a method of forming a floating gate and to a method of manufacturing a non-volatile semiconductor memory device comprising a floating gate.
[0003] 2. Description of the Related Art
[0004] Semiconductor memory devices are generally divided into volatile semiconductor memory devices and non-volatile semiconductor memory devices. In the volatile semiconductor memory device, data stored in the cell is dissipated when power is not applied. However, in the non-volatile semiconductor memory, stored data in the cell is retained even when power is not applied thereto. Because non-volatile semiconductor memory devices can store data for long periods of time, they are used to meet the current high demand for flash semiconductor memory devices such as EEPROMs (Electrically Erasable and Programmable Read Only Memories).
[0005] Meanwhile, flash semiconductor memory devices can be generally categorized as stacked flash semiconductor memory devices and split gate flash semiconductor memory devices. The split gate type of flash semiconductor memory device has a structure wherein a floating gate and a control gate are separated from each other, and the floating gate is electrically insulated from the outside. Information is stored in a memory cell of the split gate type of flash semiconductor memory device using the yprinciple that current in a memory cell changes depending on electron injection (programming)/electron discharge (erasing) into/from the floating gate. In the electron injection, hot electrons are injected into the floating gate by a channel hot electron injection (CHEI) mechanism. The electron discharge is accomplished by Fowler-Nordheim (F-N) tunneling through a tunnel insulation layer between the floating gate and the control gate of the split gate type of flash semiconductor memory device. In connection with the electron injection (programming) and electron discharge (erasing), a voltage distribution may be explained as an equivalent capacitor model. Recently, the split gate type of flash semiconductor memory device has been widely used for the purpose of storing data.
[0006] The efficiency of the split gate type of flash semiconductor memory deviceeasy transferenceis required depends on the ease in which electrons can be transferred from the floating gate to the control gate. Therefore, various research into the structure of the floating gate aims at improving the efficiency of electron transference in the hope of realizing a floating gate having a small cell and, in turn, a non-volatile semiconductor memory device having lower power consumption, and an excellent ability to be integrated with a logic device.
[0007] For example, U.S. Pat. No. 5,029,130 discloses a method of manufacturing a floating gate capable of promoting the transference of electrons from the floating gate to a control gate. The method entails oxidizing an upper portion of the floating gate to increase the sharpness of the edge of the floating gate. However, the sharpness is increased only at the upper portion of the floating gate. Accordingly, the speed at which electrons can be transferred from the floating gate to the control gate is still rather limited.
[0008] Korean Laid-Open Patent Publication No. 2001-91532 discloses a method of manufacturing a split gate type of flash semiconductor memory device in which a gate oxide is formed on a silicon substrate, and then a polysilicon layer and a nitride layer are sequentially formed on the substrate including over the gate oxide. The nitride layer is selectively etched by a photolithographic process to form a nitride mask pattern. Then, an oxide layer is formed on the polysilicon layer. The polysilicon layer and the nitride mask pattern are removed by etching to leave a portion of the polysilicon layer beneath the oxide layer. After an interpoly tunnel insulation layer is formed, a control gate is formed on the oxide layer, the interpoly tunnel insulation layer and the gate oxide. Impurities are implanted between the polysilicon layer and the oxide layer to form source/drain regions, whereby the split gate type flash semiconductor memory device is completed. According to the above-mentioned publication, the split gate flash semiconductor memory device has enhanced programming and erasing efficiencies and improved endurance in terms of its programmability and erasability.
[0009] Meanwhile, Japanese Laid-Open Patent Publication No. 1999-26616 discloses a split gate type of memory device including an insulation layer for a floating gate formed on a semiconductor substrate, an insulation layer on the floating gate, a sidewall silicon oxide layer covering the sidewall of the floating gate, and a control gate insulated from the floating gate by the insulation layer and the sidewall silicon oxide layer. In this split gate type of memory device, the floating gate comprises polysilicon, and a silicon oxide layer is substituted for at least a portion of the polysilicon near the sidewall of the floating gate electrode. According to the publication, data writing and holding characteristics of the split gate type of memory device are improved without causing variations in the threshold voltage at the control gate, and data from being excessively erased.
[0010] However, in the methods described above, additional processes are required for forming the insulation layer between the floating gate and the control gate, and the gates may not be precisely aligned. Therefore, problems still remain, such as excessive cell size and the difficulty of integrating the memory device with a logic device.
SUMMARY OF THE INVENTION
[0011] An feature of the present invention is to provide a method of forming a floating gate having enhanced electron discharging and injecting efficiencies.
[0012] Another feature of the present invention is to provide a method of manufacturing a non-volatile semiconductor memory device having a floating gate that is accurately aligned with a control gate.
[0013] In accordance with one aspect of the present invention, an edge portion of a conductive pattern, constituting a floating gate, is provided with a high degree of sharpness. To this end, first, a conductive layer is formed on a semiconductor substrate. Next, the conductive layer is patterned using a photolithographic process to form a conductive a pattern on the semiconductor substrate. Then, a first insulation layer is formed on a sidewall of the conductive pattern in such a way that the sharpness of the edge portion of the conductive pattern is increased. Subsequently, a second insulation layer is formed at the upper portion of the conductive pattern so that the edge portion of the conductive pattern is even further increased.
[0014] In accordance with another aspect of the present invention, an underlying structure including a first conductive pattern is formed on a semiconductor substrate. A first insulation layer is formed on a sidewall of the first conductive pattern. Subsequently, a second conductive pattern that will serve as a control gate is formed on the first insulation layer. Preferably, the second conductive pattern is formed by etching conductive material using a dry etching process. Then, a second insulation layer is formed on the second conductive pattern.
[0015] In accordance with still another aspect of the present invention, a first insulation layer and a first conductive layer are sequentially formed on a semiconductor substrate. Then, the first conductive layer is etched to pattern the same in a first direction. A second insulation layer is formed on the etched first conductive layer. The first insulation layer and the etched first conductive layer are etched to pattern the same in a second direction and thereby form a first conductive pattern on the first insulation layer. A sidewall of the first conductive pattern is oxidized to form a first oxide layer on the sidewall of the conductive layer. A second conductive layer is formed on the semiconductor substrate including over the first conductive pattern and the second insulation layer. The second conductive layer is then patterned to form a second conductive pattern. Preferably, the patterning of the second conductive layer is performed using a dry etching process. Subsequently, a source region is formed in the semiconductor substrate adjacent the first conductive pattern. Then, the second insulation layer is etched away. An upper portion of the first conductive pattern is oxidized to form a second oxide layer. Finally, a drain region is formed in the semiconductor substrate adjacent the second conductive pattern.
[0016] According to the present invention, the sharp edge portion of the floating gate enhances the efficiencies of electron discharging and injecting. In addition, the alignment between the floating gate and the control gate is ensured by forming the control gate using a dry etching process. Furthermore, the split gate type of flash semiconductor memory device of the present invention can be produced with a, a higher degree of integration than a conventional flash semiconductor memory device resulted whose cell size is 2-Tr. Still further, the split gate type of flash semiconductor memory device of the present invention, when used in a logic circuit, facilitates a high speed reading and writing of data without consuming a large amount of power.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other objects, features and advantages of the present invention will become more readily apparent by referring to the following detailed description thereof made in conjunction with the accompanying drawings.
[0018] [0018]FIG. 1 is a flowchart illustrating one embodiment of a method of manufacturing a floating gate according to the present invention;
[0019] [0019]FIGS. 2A to 2 C are cross-sectional views of a substrate, illustrating the method of forming the floating gate of a non-volatile semiconductor memory device according to the present invention as outlined in FIG. 1;
[0020] [0020]FIG. 3 is a plan view of a non-volatile semiconductor memory device according to the present invention;
[0021] [0021]FIG. 4 is a flowchart illustrating another embodiment of a method of manufacturing a non-volatile semiconductor memory device according to the present invention;
[0022] [0022]FIGS. 5A to 5 C are cross-sectional views of a substrate, illustrating the method of manufacturing the non-volatile semiconductor memory device according to the embodiment outlined in FIG. 4;
[0023] [0023]FIG. 6 is a flowchart illustrating still another embodiment of a method of manufacturing a non-volatile semiconductor memory device according to the present invention; and
[0024] [0024]FIGS. 7A to 7 K are cross-sectional views of a substrate, illustrating still another embodiment of a method of forming a non-volatile semiconductor memory device according to present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present invention now will be described more fully hereinafter with reference to the accompanying drawings. Note, like reference numbers designate like elements throughout the drawings. Also, the relative thickness of layers may be exaggerated in the drawings for clarity in illustrating the present invention.
[0026] [0026]FIG. 1 outlines a first embodiment of a method of manufacturing a floating gate according to the present invention.
[0027] Referring to FIG. 1, a conductive layer of silicon (Si), e.g., amorphous silicon, polysilicon, or silicon doped with impurities, is formed on a semiconductor substrate (step S 11 ). Then, the conductive layer is patterned using a photolithographic process to form a conductive pattern on the semiconductor substrate. Alternatively, the conductive layer may comprise a metal such as copper (Cu), tungsten (W), aluminum (Al), titanium (Ti), and the like.
[0028] Next, a first insulation layer is formed on a sidewall of the conductive pattern so that an edge portion of the conductive pattern has a first sharpness (step S 12 ). More specifically, the first insulation layer is formed by oxidizing the sidewall of the conductive pattern.
[0029] Then, a second insulation layer is formed at an upper portion the conductive pattern so that the edge portion of the conductive pattern becomes even sharper (step S 13 ). The second insulation layer is also formed by oxidizing the conductive pattern but this time at the upper portion thereof.
[0030] [0030]FIGS. 2A to 2 C illustrate, in detail, the first embodiment of a method of forming a floating gate of a non-volatile semiconductor memory device according to the present invention.
[0031] Referring to FIG. 2A, a conductive layer is formed on a semiconductor substrate 10 . The conductive layer is patterned by a photolithographic process to form a conductive pattern 20 on the semiconductor substrate 10 . The conductive pattern 20 constitutes an underlying structure such as an electrode, a plug, a bit line or a word line. Preferably, however, the conductive pattern 20 constitutes a floating gate of a flash semiconductor memory device.
[0032] When the conductive pattern 20 constitutes the floating gate of a flash semiconductor memory device, the conductive pattern 20 is formed of amorphous silicon, polysilicon or silicon doped with impurities by a low pressure chemical vapor deposition (LPCVD) process. When the conductive pattern 20 is formed using polysilicon, the conductive pattern 20 may have a polycide structure in which a metal silicide film is formed on a polysilicon film. Alternatively, when the conductive pattern 20 is formed using polysilicon or amorphous silicon, the conductive pattern 20 may be doped with impurities by a PCl 3 diffusion process, an ion implantation process, or an in-situ doping process.
[0033] Also, an insulation layer comprising an oxide or nitride layer may be formed on the semiconductor substrate 10 before the conductive pattern 20 is formed. Then, the conductive layer is formed on the insulation layer. In this case, the conductive layer is formed on the semiconductor substrate 10 by a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process or a sputtering process. The conductive layer is patterned to form the conductive pattern 20 on the insulation layer.
[0034] Referring to FIG. 2B, a first insulation layer 22 is formed on a sidewall of the conductive pattern 20 by oxidizing only the sidewall of the conductive pattern 20 . As a result, the edge portion 23 of the conductive pattern 20 becomes cuspate, subtending a first angle Θ 1 with a vertical axis (an axis perpendicular to substrate 10 ). That is, the sidewall of the conductive pattern 20 becomes concave, whereby the edge portion 23 of the conductive pattern 20 becomes more pointed, in accordance with the formation of the first insulation layer 22 on the sidewall of the conductive pattern 20 .
[0035] In the present embodiment, the first insulation layer 22 is formed on the sidewall of the conductive pattern 20 by merely oxidizing the sidewall of the conductive pattern 20 , i.e., without an additional process such as a CVD process or a PVD process. More specifically, the first insulation layer 22 is formed by a simple thermal oxidation process or a local oxidation of silicon (LOCOS) process. As a result, the first insulation layer 22 is rounded to thereby form the cuspate edge portion 23 of the conductive pattern 20 . The edge portion 23 thus has a first sharpness corresponding to the first angle Θ 1 .
[0036] Note, also, a nitride layer may be formed at an upper portion of the conductive pattern 20 as an oxidation blocking layer before the first insulation layer 22 is formed on the sidewall of the conductive pattern 20 .
[0037] Referring to FIG. 2C, a second insulation layer 26 is formed at the upper portion of the conductive pattern 20 by oxidizing the upper portion of the conductive pattern 20 . The oxidizing process forms a concavity in the upper portion of the conductive pattern 20 such that the second insulation layer 26 has a slightly rounded shape. As a result, the edge portion of the conductive pattern 20 becomes even more cuspate, as designated by reference numeral 27 , subtending a second angle Θ 2 with a horizontal axis (parallel to the substrate 10 ). That is, the edge portion 27 of the conductive pattern 20 attains a second sharpness greater than that of the first sharpness.
[0038] In the present embodiment, the second insulation layer 26 is formed at the upper portion of the conductive pattern 20 by a thermal oxidation process or an LOCOS process, i.e., without a complex additional process such as a CVD process or a PVD process.
[0039] Referring to FIG. 3, a non-volatile semiconductor memory device of the present invention includes an insulation region and active regions, and a floating gate 220 and a control gate 320 disposed on both sides of the insulation region. The direction A-A′ in FIG. 3 across the floating gate 220 will hereinafter be referred to as the “first direction” while the direction B-B′ across the active regions and the insulation region will be hereinafter referred to as the “second direction”.
[0040] According to the present embodiment, both the upper portion and the sidewall of the floating gate are oxidized to form a sharp edge portion. Thus, the edge portion of the floating gate is much sharper than that of the conventional floating gate in which only the sidewall is oxidized. The sharper edge portion allows electrons to move more efficiently from the floating to a control gate. Accordingly, the characteristics of a non-volatile semiconductor memory device employing the floating gate of the present invention are enhanced.
[0041] [0041]FIG. 4 outlines a method of manufacturing a non-volatile semiconductor memory device according the present invention.
[0042] Referring to FIG. 4, an underlying structure, including a first conductive pattern, is formed on a semiconductor substrate (step S 21 ). Then, a first insulation layer is formed on a sidewall of the conductive pattern (step S 22 ).
[0043] Next, a second conductive pattern serving as a control gate is formed on the first insulation layer (step S 23 ). Then, a second insulation layer is formed on the second conductive pattern (step S 24 ).
[0044] [0044]FIGS. 5A to 5 D illustrate in detail the method of manufacturing the non-volatile semiconductor memory device according to the present invention. FIGS. 5A to 5 D are each a sectional view as taken along line B-B′ in FIG. 3.
[0045] Referring to FIGS. 3 and 5A, an underlying structure 40 including a first conductive pattern 50 , which corresponds to a floating gate of the non-volatile semiconductor memory device, is formed on a substrate 30 . Note, also, an underlying insulation layer 45 comprising an oxide or nitride layer may be formed between the substrate 30 and the first conductive pattern 50 . In that case, the underlying insulation layer 45 is formed by a CVD process, a PVD process, or a sputtering process using an oxide, a nitride or oxynitride.
[0046] The first conductive pattern 50 is formed of amorphous silicon, polysilicon, silicon doped with impurities or polysilicon having a metal silicide formed thereon by an LPCVD process. The first conductive pattern 50 is produced by forming a first conductive layer (not shown) on the substrate 30 , primarily etching the first conductive layer to pattern the same in the first direction, and by then secondarily etching first conductive layer to pattern the same in the second direction.
[0047] More specifically, after the first conductive layer is formed on the substrate 30 , an oxide layer (not shown) or a nitride layer (not shown) is formed on the first conductive layer to define the active region. A photoresist pattern is formed on the oxide layer or the nitride layer, and then the first conductive layer is patterned in the first direction using a photolithographic process. The patterning of the first conductive layer in the first direction prevents the active region and the first conductive pattern corresponding to the floating gate from being misaligned. Subsequently, an insulation layer (not shown) is formed on the etched first conductive layer. Preferably, the insulation layer comprises nitride. After a photoresist pattern is formed on the insulation layer, the etched first conductive layer is patterned in the second direction using the photoresist pattern as an etching mask.
[0048] Referring to FIG. 5B, a first insulation layer 52 is formed on a sidewall of the first conductive pattern 50 . The first insulation layer 52 is an oxide layer formed by oxidizing the sidewall of the first conductive pattern 50 , i.e., without an additional process such as a CVD process or a PVD process. More specifically, the first insulation layer 52 is formed from the first conductive pattern 50 by a simple thermal oxidation process or a local oxidation of silicon (LOCOS) process. As a result, the first insulation layer 52 is rounded, i.e., is crescent-shaped. Accordingly, the sharpness of the edge portion of the first conductive pattern 50 is increased.
[0049] Referring to FIG. 5C, a second conductive pattern 60 corresponding to a control gate of the non-volatile semiconductor memory device is formed on the first insulation layer 52 . The second conductive pattern 60 is formed of a layer of amorphous silicon, polysilicon, silicon doped with impurities or polysilicon having a metal silicide thereon. The layer is then anisotropically etched (dry etched) to pattern the same and thereby complete the forming of the second conductive pattern.
[0050] According to the present embodiment, the second conductive pattern 60 is formed in the shape of a spacer by an anisotropic dry etching process. To this end, a plasma etching process or a reactive ion etching (RIE) process may be used. Unlike a photolithographic process whose degree of resolution is limited, the dry etching process prevents a misalignment between the first conductive pattern 50 and the second conductive pattern 60 , thereby ensuring that the non-volatile semiconductor memory deviceperforms well.
[0051] Referring to FIG. 5D, a second insulation layer 54 is formed on the first conductive pattern 50 . The second insulation layer 54 is an oxide layer formed by oxidizing an upper portion of the first conductive pattern 50 . In particular, the second insulation layer 54 is formed at the upper portion of the first conductive pattern 50 by a thermal oxidation process or an LOCOS process without a complex extra process such as a CVD process or a PVD process. Accordingly, the second insulation layer 54 is interposed between the first conductive pattern 50 and the second conductive pattern 60 . As a result, the edge portion of the first conductive pattern 50 becomes even sharper.
[0052] In this embodiment as well, both the upper portion and the sidewall of the first conductive pattern 50 are oxidized to increase the sharpness at the edge portion thereof. When the non-volatile semiconductor memory device employs the first conductive pattern 50 as a floating gate, electrons migrate efficiently from the floating gate to the control gate.
[0053] In the embodimentas described above, the second insulation layer 54 is formed at the upper portion of the first conductive pattern 50 by oxidizing the upper portion of the first conductive pattern 50 , after the second conductive pattern 60 is formed. Alternatively, the second insulation layer 54 may be formed before the second conductive pattern 60 is formed on the first conductive pattern 50 .
[0054] [0054]FIG. 6 outlines another method of manufacturing a non-volatile semiconductor memory device according to the present invention.
[0055] Referring to FIG. 6, a first insulation layer and a first conductive layer are formed sequentially on a semiconductor device (step S 30 ). Then, the first conductive layer is etched so as to be patterned in the first direction (step S 31 ). Subsequently, a second insulation layer is formed on the first conductive layer (step S 32 ).
[0056] Next, the first insulation layer and the first conductive layer are etched so as to be patterned in the second direction to form a first conductive pattern on the first insulation layer (step S 33 ). A sidewall of the first conductive pattern is oxidized to form a first oxide layer on the sidewall of the first conductive layer (step S 34 ).
[0057] A second conductive layer is then formed on the semiconductor substrate including over the first conductive pattern and the second insulation layer (step S 35 ). The second conductive layer is patterned to form a second conductive pattern (step S 36 ). After the second conductive pattern is formed, a source region is formed in the semiconductor substrate adjacent the first conductive pattern (step S 37 ).
[0058] Next, the second insulation layer is etched (step S 38 ). Then, the upper portion of the first conductive pattern is oxidized to form a second oxide layer at the upper portion of the first conductive pattern (step S 39 ). Subsequently a drain region is formed in the semiconductor substrate adjacent the second conductive pattern (step S 40 ).
[0059] [0059]FIGS. 7A to 7 K illustrate in more detail the method of forming the non-volatile semiconductor memory device as outlined above. More specifically, FIGS. 7A to 7 C are cross-sectional views of the substrate taken in the first direction in FIG. 3, and FIGS. 7D to 7 K are cross-sectional views of the substrate taken in the second direction in FIG. 3.
[0060] Referring to FIG. 7A, a first insulation 110 and a first conductive layer 200 are sequentially formed on a semiconductor substrate 100 . The first insulation layer 110 is an oxide, nitride, or oxynitride layer, and the first conductive layer 200 comprises polysilicon, amorphous silicon, silicon doped with impurities, or polysilicon having a metal silicide thereon. The first conductive layer 200 is formed by a CVD process, a PVD process or a sputtering process as
[0061] Referring to FIG. 7B, the first conductive layer 200 is etched so as to be patterned in the first direction. In particular, an oxide layer (not shown) or a nitride layer (not shown) is formed on the first conductive layer 200 . After a photoresist pattern is formed on the oxide layer or the nitride layer, the first conductive layer 200 is patterned in the first direction by a photolithographic process. This prevents misalignment in the first direction between the active region and the first conductive pattern 201 constituting the floating gate.
[0062] Referring to FIG. 3 and FIG. 7C, a second insulation layer 220 is formed on the first conductive pattern 201 . Preferably, the second insulation layer 220 comprises a nitride, e.g., Si 3 N 4 , SiN x , SiONI. In particular, the second insulation layer 220 is formed by a CVD process, a plasma enhanced chemical vapor deposition (PECVD) process, a PVD process or a sputtering process.
[0063] Referring to FIG. 7D, the first insulation layer 110 and the first conductive pattern 201 are secondarily etched so as to be patterned in the second direction. In particular, a photoresist pattern is formed on the second insulation layer 220 , and the first conductive pattern 201 and second insulation layer 220 are etched using the photoresist pattern as a mask.
[0064] Referring to FIG. 7E, a sidewall of the first conductive pattern 201 is oxidized to form a first oxide layer 240 on the sidewall of the first conductive pattern 201 . Accordingly, an edge portion of the first conductive pattern 201 has a slightly rounded shape at the sidewall of the first conductive pattern 201 , whereby the sharpness of the edge portion is increased. And, as with the embodiments described above, the first oxide layer 240 is formed by merely oxidizing the sidewall of the first conductive pattern 201 , i.e., without a complex additional process such as a CVD process or a PVD process. That is, the first oxide layer 240 is formed by a simple thermal oxidation process or an LOCOS process. Furthermore, the second insulation layer 220 functions as an anti-oxidant layer during the forming of the first oxide layer 240 , preventing the upper portion of the first conductive pattern 201 from oxidizing while allowing only the sidewall of the first conductive pattern 201 to be oxidized.
[0065] Referring to FIG. 7F, a second conductive layer 300 is formed on the semiconductor substrate 100 including over the first conductive pattern 201 and the second insulation layer 220 . The second conductive layer 300 is advantageously formed by an LPCVD process and comprises polysilicon, amorphous silicon, silicon doped with impurities or polysilicon having a metal silicide thereon. The second conductive layer 300 is etched to form a control gate of the flash semiconductor memory device.
[0066] Referring to FIG. 7G, a second conductive pattern 320 is formed in the shape of a spacer by etching the second conductive layer 300 . In particular, the second conductive pattern 320 is formed by an anisotropic dry etching process. To this end, a plasma etching process, a reactive ion etching (RIE) process, may be used for forming the second conductive pattern 320 . A misalignment between the first conductive pattern 201 and the second conductive pattern 320 is prevented because the second conductive pattern 320 is formed by an anisotropic dry etching process, and not by a photolithographic process whose degree of resolution is rather limited. In addition, the anisotropic dry etching process removes part of the second conductive layer 300 to facilitate the forming of a source region.
[0067] Referring to FIG. 7H, the source region 400 is formed in the semiconductor substrate 100 adjacent the first conductive pattern 201 . The source region 400 is formed by doping impurities into the semiconductor substrate 100 using an ion implantation process.
[0068] Referring to FIG. 7I, the second insulation layer 220 on the first conductive pattern 201 is removed. To this end, the second insulation layer 220 is treated with an etching solution containing phosphoric acid (H 3 PO 4 ) at a temperature of about 180° C.
[0069] Referring to FIG. 7J, a second oxide layer 260 is formed by oxidizing the upper portion of the first conductive pattern 201 . Accordingly, the edge portion of the first conductive pattern 201 becomes slightly rounded at the upper portion of the first conductive pattern 201 , i.e., relative a horizontal direction or a direction parallel to the semiconductor substrate 100 .
[0070] According to the present embodiment, both of the upper portion and the sidewall of the first conductive pattern 201 are oxidized to form a sharp edge portion where the sidewall and the upper portion of the first conductive pattern 210 meet. That is, the edge portion of the first conductive pattern 201 will be much sharper than that of the conventional floating gate. As a result, electrons will move more efficiently from the floating to the control gate, thereby significantly enhancing the characteristics of the non-volatile semiconductor memory device.
[0071] Referring to FIG. 7K, a drain region 420 is formed in the semiconductor substrate 100 adjacent the second conductive pattern 320 . The drain region 420 is formed by implanting impurities into the semiconductor substrate 100 using an ion implantation process.
[0072] A wiring (not shown) and a drain contact (not shown) are formed at the upper portion of and adjacent the second conductive pattern 320 by a silicidation process and a metallization process to complete the flash semiconductor memory device.
[0073] Compared to the conventional non-volatile semiconductor memory device, such as a stacked type of flash semiconductor memory device, the split gate type of flash semiconductor memory device manufactured according to the method of the present invention is less prone to problems such as over-erasing and high power consumption in a data writing mode. Also, the split gate type of flash semiconductor memory device can be manufactured according to the present invention to have a lower integration density than a conventional flash semiconductor memory device having a cell size of 2-Tr. Furthermore, the split gate type of flash semiconductor memory device of the present invention can be readily integrated with a logic circuit to produce a device that can read and write of data, at a high speed and yet consume a relatively low amount of power in doing so.
[0074] Finally, although the present invention has been described in connection with the preferred embodiments thereof, the present invention is not so limited. Rather, various changes to and modifications of the preferred embodiments are seen to be within the true spirit and scope of the present invention as hereinafter claimed. | A method of manufacturing a floating gate provides an enhancement for the efficiencies of electron discharge and injection. First, a conductive pattern, constituting the arefloating gateforeon, is formed on a substrate. A first insulation layer is formed on a sidewall of the conductive pattern, and then a second insulation layer is formed at an upper portion of the conductive pattern in ways that each increase the sharpness of an edge portion where the sidewall and upper portions of the conductive pattern meet. Therefore, electron transference from the floating gate to a control gate is facilitated. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reader having a plurality of photosensors and, more particularly, to an image reader having a means for correcting variations in photoelectric conversion outputs from photosensors.
An image reader according to the present invention is widely applied to an image input apparatus such as a facsimile system, a digital copying machine, or the like, and input units for other image processing apparatuses.
2. Related Background Art
In an image reader, an original as an object to be read is irradiated with light, so that reflection light or transmission light becomes incident on a plurality of photosensors so as to be ready by them. Thus, image information of the original is output as an electrical signal.
In this case, photoelectric conversion characteristics of these photosensors slightly vary from each other. As emphasized on the graph in FIG. 4(A), photoelectric conversion outputs from the photosensors vary even with an identical original concentration.
In a conventional image reader, in order to correct the output variations and to obtain an electrical signal accurately corresponding to image information of an original, a reference white original is read, and a photoelectric conversion output is stored as correction reference data. A photoelectric conversion output of a normal original is corrected using the correction reference data, thereby obtaining a uniform output.
However, in the conventional image reading, an original which is approximate to reference white does not cause variations in outputs, and an image of the original can be accurately converted to an electrical signal. However, when an original has a high concentration and a low reflectivity or when an output is attenuated due to a change in temperature or aging, variations in output levels after correction become large, and an electrical signal which precisely corresponds to the image of the original cannot be obtained.
As shown in the graph in FIG. 4(B), since the photoelectric conversion outputs are corrected with reference to the reference white, they can be accurately corrected according to the correction reference data, and output levels among the photosensors are rendered uniform. However, as the concentration of an original becomes high and its reflectivity is decreased or as the outputs are decreased due to a change in temperature or aging, the outputs cannot be accurately corrected by the correction reference data, and variations in output levels among the photosensors become large. For this reason, image reading is inaccurate, and this results in poor reliability.
SUMMARY OF THE INVENTION
An image reader according to the present invention comprises:
a plurality of photosensors which photoelectrically convert incident light from an object to be read;
memory means for storing, as correction reference data, data corresponding to photoelectric conversion outputs from the photosensors when the object to be read presents a uniform halftone image; and
correction means for obtaining uniform photoelectric conversion output levels from the photosensors using the correction reference data.
Data corresponding to the photoelectric conversion outputs from the photosensors when the object is a uniform halftone image is used as the correction reference data. Therefore, variations in output levels among the photosensors after correction can be minimized, and an electrical signal accurately corresponding to an image of an object to be read can be obtained.
FIG. 5 is a graph showing the relationship between an original concentration and a photoelectric conversion output which is corrected using the correction reference data according to the present invention.
As shown in FIG. 5, since a photoelectric conversion output corresponding to a halftone original between white and black is used as the correction reference data, variations in corrected output levels with respect to a change in reflectivity of an original, a change in temperature, aging, or the like can be suppressed. Therefore, when the correction reference data is set at an optimal level with respect to an object to be read, as will be described later, reliable image reading can be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram schematically showing an image reader according to a first embodiment of the present invention;
FIG. 2 is a block diagram schematically showing a second embodiment of the present invention;
FIG. 3 is a block diagram schematically showing a third embodiment of the present invention;
FIG. 4(A) is a graph showing variations in photoelectric conversion characteristics among photosensors, and FIG. 4(B) is a graph showing the relationship between an original concentration and a photoelectric conversion output which is corrected using correction reference data with reference to a white original in a conventional image reader; and
FIG. 5 is a graph showing the relationship between an original concentration and a photoelectric conversion output which is corrected using correction reference data according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings.
FIG. 1 is a block diagram schematically showing an image reader according to a first embodiment of the present invention.
Referring to FIG. 1, a plurality of photosensors (e.g., photoelectric conversion type sensors) are one- or two-dimensionally arranged on a photosensor unit 1, so that photoelectric conversion outputs from the respective photosensors are sequentially output by a driver (not shown). Light from a light source (e.g., an LED) 3 becomes incident on the photosensor unit 1 through an original 2 as an object to be read. The incident light need only carry image information of the original 2 in any form, and can be light reflected by the orignal 2 or light transmitted through the original 2.
A drive voltage is applied from a sensor power source unit 5 to the photosensor unit 1 through a switch 4. The sensor power source unit 5 has a normal voltage terminal used in a reading mode and a low voltage terminal of a voltage lower than a normal voltage, which is used in a setting mode for generating correction reference data. The low voltage can be set at a desired value, and is determined in accordance with the level of correction reference data, as described above.
The switch 4 is operated in accordance with the respective modes. Thus, the normal voltage is applied to the photosensor unit 1 in the reading mode and the low voltage is applied to the photosensor unit 1 in the setting mode. Note that FIG. 1 illustrates the state of the reading mode.
Photoelectric conversion outputs from the photosensor unit 1 are amplified by an amplifier 6, and are output to a correction data generating circuit 8 or a correction circuit 9 through a switch 7. The switch 7 is synchronized with the switch 4. The switch 7 outputs the photoelectric conversion outputs amplified by the photosensor unit 1 to the correction circuit 9 in the reading mode, and outputs them to the correction data generating circuit 8 in the setting mode.
In the setting mode, the correction data generating circuit 8 converts the input photoelectric conversion outputs into digital data, and stores the digital data as correction reference data in a programmable/erasable memory unit 10.
In the reading mode, the correction circuit 9 corrects the input photoelectric conversion outputs using the correction reference data stored in the memory unit 10, and outputs the corrected electrical signal.
The operation of this embodiment having the above arrangement will now be described.
A reference white original 2 is set, and the switches 4 and 7 are switched to the setting mode, so that a low voltage is applied from the sensor power source unit 5 to the photosensor unit 1. In this embodiment, since the photoelectric conversion type sensors are used as the photosensors, a photo current is decreased upon a decrease in application voltage. Therefore, a photoelectric conversion output which is equivalent to that obtained when a halftone original is read is input to the correction data generating circuit 8, and is stored in the memory unit 10 as the correction reference data. More specifically, when the low voltage from the sensor power source unit 5 is changed, the correction reference data can be set at a desired halftone level, as shown in FIG. 5.
After the correction reference data is stored in the memory unit 10 in this manner, the original 2 to be input is set, and the switches 4 and 7 are switched to the reading mode, so that a normal voltage is applied to the photosensor unit 1. Thus, image information on the original 2 is read and the photoelectric conversion outputs therefrom are amplified by the amplifier 6 and are then input to the correction circuit 9 through the switch 7.
The correction circuit 9 corrects the input photoelectric conversion outputs using the correction reference data stored in the memory unit 10, and outputs an electrical signal accurately corresponding to the image information on the original 2.
The correction reference data stored in the memory unit 10 can be updated each time the setting mode operation is performed upon changing of a low voltage from the sensor power source unit 5. Therefore, optimal correction reference data can be set in accordance with the state (reflectivity or the like) of the original 2.
Variations caused by offset outputs in the case of a low-reflectivity original can be minimized, and gradation errors of a halftone or dark original can be eliminated.
FIG. 2 is a block diagram schematically showing a second embodiment of the present invention. Note that the same reference numerals in this embodiment denote the same parts as in the first embodiment, and a detailed description thereof will be omitted.
A plurality of photosensors of a desired type are aligned on a photosensor unit 1, and a constant voltage for image reading is applied from a sensor power source unit 11 to the photosensor unit 1.
A normal or low voltage is applied from a power source 13 to a light source 3 through a switch 12. The switch 12 is synchronized with a switch 7, so that a normal voltage is applied to the light source 3 in the reading mode and a low voltage is applied thereto in the setting mode. More specifically, when the normal voltage is applied from the power source 13 to the light source 3, an illuminance necessary for the reading operation of an original 2 can be obtained. When the low voltage is applied from the power source 13 to the light source 3, an illuminance lower than that in the reading mode can be obtained. The light source 3 can comprise a light source, e.g., an LED, whose amount of light can be controlled.
In this embodiment having the above arrangement, a reference white original 2 is set, and the switches 12 and 7 are switched to the setting mode, so that the low voltage is applied from the power source 13 to the light source 3. Thus, since the light source 3 illuminates the reference white original 2 at a low illuminance, photoelectric conversion outputs equivalent to those when a halftone original is read are input to a correction data generating circuit 8, and are stored in a memory unit 10 as correction reference data. More specifically, when the low voltage from the power source 13 is changed, the correction reference data can be set at a desired halftone level.
After the correction reference data is stored in this manner, the reading mode operation is performed in the same manner as in the first embodiment.
FIG. 3 is a block diagram schematically showing a third embodiment of the present invention.
In this embodiment, a constant voltage in a reading mode operation is applied to a photosensor unit 1 and a light source 3.
Photoelectric conversion outputs from the photosensor unit 1 are output to an amplifier 6 through a switch 14. Meanwhile, the outputs are divided by series-connected resistors R1 and R2, and the voltagedivided outputs are also output to the amplifier 6 through the switch 14. The switch 14 is synchronized with a switch 7, so that photoelectric conversion outputs are output to a correction circuit 9 in the scanning mode, and photoelectric conversion outputs which are voltage-divided by the resistors R1 and R2 are output to a correction data generating circuit 8.
In this embodiment having the above arrangement, a reference white original 2 is set, and the switches 14 and 7 are switched to the setting mode. Thus, the voltage-divided photoelectric conversion outputs, i.e., photoelectric conversion outputs equivalent to those when a halftone original is read are input to the correction data generating circuit 8, and are then stored in a memeory circuit 10 as correction reference data. Therefore, when the resistances of the resistors R1 and R2 are changed, the correction reference data can be set at a desired halftone level, as shown in FIG. 5.
After the correction reference data is stored as described above, the reading mode operation is performed in the same manner as in the first embodiment.
As described above, in the image reader according to the above embodiments, data corresponding to photoelectric conversion outputs from the photosensors when an object to be read is a uniform holftone image is used as correction reference data, so that variations in output levels among the photosensors after correction can be suppressed, and an electrical signal accurately corresponding to an image of the object can be obtained. For this reason, even if the object has a low reflectivity, or outputs are decreased due to a change in temperature or aging, a reliable image reading operation can be performed. | An image reader, comprises a plurality of photosensors which photoelectrically convert incident light from an object to be read, a memory for storing, as correction reference data, data corresponding to photoelectric conversion outputs from said photosensors when said object to be read presents a uniform halftone image, and a correction circuit for obtaining uniform photoelectric conversion output levels among said photosensors using the correction reference data. | 7 |
FIELD OF THE INVENTION
This invention relates to magnetic fluid conditioning and more particularly to conditioning or treating fluids such as liquids, and especially water, by the use of permanent magnets. Furthermore, this invention relates to the magnetic treatment of water to encourage plant growth.
BACKGROUND OF THE INVENTION
Prior to this invention, it has been well known and documented that magnetic treatment of water can be very helpful in softening water and in helping to discourage the formation of scale associated with the handling of calcarious waters which deposit scales or encrustation on heat exchanger and conduit surfaces, such as found in water supply lines in industrial and residential situations. Also, it is known that such treated waters may be used to eliminate previously deposited scales from surfaces contacted by untreated waters.
Prior art patents relating to magnetic water conditioning techniques which utilize permanent magnets have proposed the use of everything from simple elongated bar magnets that are polarized along their longitudinal axes, to cylindrical discs that are polarized along their diameters. In some instances, elongated bar magnets that are polarized along their diameters have been advocated, and the facial polarization of disc type magnets along their axes of symmetry has also been advocated. Included with the various different types of permanently magnetized structures and their arrangements are structures which require fluid flow parallel to the polar axes of the magnets, structures which direct the fluid perpendicular to the polar axes, as well as other and various complicated and expensive structural arrangements that have advocated other desired flow characteristics. In particular, the inventor is aware of the following U.S. patents which disclose various different types of devices for magnetically conditioning water: U.S. Pat. No. 2,65 2,925 to Vermeiren; U.S. Pat. No. 2,939,830 to Green et al.; U.S. Pat. No. 3,228,878 to Moody; U.S. Pat. No. 4,146,479 to Brown; U.S. Pat. No. 4, 153,559 to Sanderson; U.S. Pat. No. 4,210,535 to Risk; and U.S. Pat. No. 4,605,498 to Kulish.
These prior art arrangements for providing the seemingly desired flow paths relative to the flux fields are expensive to incorporate into commercial designs for water conditioning and are devised primarily to prevent or remove scaling of pipes and equipment.
United States, Canadian and European investigations have also confirmed that the magnetic treatment of water can be extremely beneficial in helping to promote plant growth. These studies show healthier, richer lawn growth and increased vegetable and fruit yields. Magnetically treated water, free (neutralized) from harmful chemicals, enhances fertilizer and passes more readily through compacted topsoil. The "smaller" molecules associated with magnetically treated water are absorbed more easily through capillary action in plants and vegetable roots, and can carry beneficial nutrients to more areas than non-treated water. This results in a stronger and more well-developed root system, which in turn allows more nutrients for development of above-ground growth where photosynthesis takes place.
Even though it has been recognized that magnetic treatment can have beneficial effects on plant growth characteristics, there has not been developed, to the best of the inventor's knowledge, an effective and economical apparatus which can be easily used to treat water, or any other liquids, inexpensively by using permanent magnets.
OBJECTS OF THE INVENTION
With the above background in mind, it is a primary object of the invention to magnetically treat liquids, especially water, in a more efficient and economical manner than has been previously possible.
It is an object of this invention to magnetically treat liquids, especially water, to enhance the growth characteristics of plants.
It is a further object of the invention to provide a liquid treatment device which can be easily assembled and easily attached to a liquid source for treatment of the liquid by permanent magnets.
It is yet another object of the invention to provide a device which will have a high strength harmonic magnetic field for the treatment of liquid passing therethrough by varying the distance between magnetic poles in the treatment device in relation to the flow of liquid therethrough.
It is a still further object of the invention to provide a method of treating liquids, especially water, wherein the molecular clusters comprising the liquid being treated are subjected to a high strength variable harmonic magnetic field in order to break down the molecular clusters.
SUMMARY OF THE INVENTION
An apparatus is provided for magnetically treating a fluid comprised of non-polar molecular clusters, such as water, by having the fluid flow therethrough. The apparatus includes a housing with an inlet and an outlet, the housing being adapted to permit the fluid to flow therethrough between the inlet and the outlet within the interior of the housing. Permanent magnet means are associated with the housing to provide a harmonic magnetic field within the housing, the strength of the harmonic magnetic field being variable in response to the flow of fluid through the housing.
In a first embodiment, the magnet means includes a plurality of permanent magnets positioned within the housing. A first magnet is stationarily positioned transverse to the fluid flow direction and has first and second sides of opposite polarity. There is also an opening through the first magnet. Positioned adjacent the first magnet is a second magnet. The second magnet is spaced from the first magnet and has an outer circumference spaced from the interior surface of the housing. The second magnet also has first and second sides of opposite polarity. The first and second magnets are parallel to each other with sides of opposite polarity facing each other. The first and second magnets are spaced from each other by a plug member which fits into an opening through the second magnet and which extends into the opening of the first magnet. The plug member spaces the first and second magnets from each other and has channels therethrough to permit fluid to flow around the second magnet, through the channels and into the central opening of the first magnet.
The second magnet is further held in position within the housing by means of various resilient supports and a resilient spacer between the first and second magnet. In this manner, fluid flow through the housing causes the second magnet to move within the housing under the influence of the fluid flow therefrom. The movement between the first and second magnets establishes a harmonic magnetic field through which the fluid can flow.
In the first preferred embodiment, a third magnet is positioned adjacent the first magnet on the side of the first magnet opposite the second magnet and is held within the housing in the same manner as the second magnet.
In a second embodiment of the invention, the housing is a hollow pipe with magnets positioned diametrically opposite each other on the outside of the pipe. The interior of the pipe is filled with a plurality of spherical isotropic magnets which are moveable with respect to each other under the influence of fluid flowing through the housing or pipe.
A method is also taught herein wherein non-polar molecular clusters are magnetically treated. A confined flow path is provided and a harmonic magnetic field capable of having variable magnetic strength within and along the confined flow path is created using permanent magnets. The strength of the harmonic magnetic field is variable along the length of the flow path in response to fluid passing therethrough. By passing fluid to be treated through the flow path and through the harmonic magnetic field, the magnetic field strength varies in response to the flow characteristics of the fluid and causes the non-polar molecular clusters to reorient in a polar manner and break apart.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and many of the attendant advantages of the instant invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
FIG. 1 is a cross-sectional view of one embodiment of a magnetic fluid treatment device of the present invention showing fluid flow therethrough;
FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is an isometric view of one of the spacer plugs which space the magnets as shown in FIG. 1;
FIG. 5 is a cross-sectional view and partially cut-away view of a second embodiment of a magnetic fluid treatment device of the present invention; and
FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring now in greater detail to the figures of the drawings wherein like reference characters refer to like parts, a magnetic fluid treatment device of the present invention is shown generally at 10 in FIG. 1. In the first embodiment shown in FIG. 1, the treatment device comprises a housing 100 surrounding a magnet assembly 200 through and around which the fluid being treated passes. A support structure 300 positions and holds the magnet assembly 200 within the housing. Further provided at the inlet 102 into the housing 100 is a coupling device 400 for joining the treatment device to a fluid source.
As shown in FIG. 1, the housing 100 comprises an inlet housing member 104 and an outlet housing member 106. Both of the housing members are preferably molded plastic and sealingly joined together at a seam 105 by any suitable means, for example by heat or adhesive sealing. The inlet housing member 104 has the reduced diameter inlet portion 102, and the outlet housing member 106 has a reduced diameter outlet portion 110. The two housing members 104, 106 in the preferred embodiment have a circular cross-section and are coaxially aligned when the two members are joined. The housing members are preferably made of high-strength, non-magnetic material, such as plastic, which is capable of withstanding the pressure of fluid flow therethrough. Likewise, the inlet 102 and the outlet 110 in the preferred embodiment have circular cross-sections and are coaxially aligned when the two housings members are joined.
The magnet assembly 200 in the first embodiment includes, as shown in FIG. 1, three circular, planar, permanent magnets 202, 204, 206. The magnets are each magnetically oriented with the magnetic poles on the planar surfaces thereof. As shown in FIG. 1, the first magnet 202 has its negative (north) pole surface adjacent and spaced from the positive (south) pole surface of the second magnet 204. The positive (south) pole surface of the third magnet 206 is adjacent and spaced from the negative (north) pole surface of the second magnet 204 opposite the first magnet 202. All of the magnets 202, 204, 206 are cylindrical disc-shaped magnets, and each has a circular opening 210, 212, 214, respectively, therethrough.
As shown in FIG. 1, the support structure 300 which holds and maintains the magnet assembly 200 within the housing 100 includes a pair of first plugs 302, 304 that, when positioned within the openings 210, 214 of the first and third magnets and in opposite sides of the opening 212 in the central magnet, join the three magnets together in a spaced relationship. The support structure 300 further includes a plurality--in this preferred embodiment, six--of magnet holders 306, 308, 310, 312, 314 and 316 (not shown in the cross section of FIG. 1 ) which extend inwardly from the inside surface of the two housing members 104, 106 toward and against the positive pole surface 211 of the first magnet 202 and toward and against the negative pole surface 213 of the third magnet 206. The magnet holders 306-316 each have positioned thereover a base member or cap 306, 308a, 310aa, 312a, 314a and 316a (not shown in cross section of FIG. 1 ), respectively, and as shown in cross section in FIG. 1 at 312a, 308a. The magnet holders are preferably integrally molded with the inside of the inlet and outlet housing members 104, 106 at equidistant locations around each housing member (FIG. 2), and the base members or caps over the magnet holders 306-316 urge against the outer planar surfaces of the first and third magnets as discussed above. The base members or caps are comprised of compressible elastomeric material, such as synthetic rubber or plastic which allows flexibility of compression and expansion.
The plugs 302, 304 are preferably made of molded plastic material, fit securely within the openings 210, 214 in the first and third magnets 202, 206 and prevent fluid flow therethrough, and project into each side of the opening 212 through the second magnet 204. As can bee seen in FIGS. 3 and 4, each of the plugs 302, 304 has four circumferentially positioned extensions 303a-d and 305a-d, respectively.
These projections 303a-d, 305a-d each have at a right angle thereto a second projection or knob 307a-d, 309a-d and slip-fitted around each knob is a cap 311a-d, 313a-d, respectively. Each cap has an outside thickness "A" that, when the plugs 302, 304 are in position, spaces the first and third magnets from each side of the second magnet by a distance "A." Furthermore, when the plugs and associated projections are positioned within the respective openings through the first, second and third magnets, a plurality of channels are formed between the caps on the projections 307a-d, 309a-d. These channels, as will be discussed, permit fluid which fills the spaced distance between the first and second magnets to flow through the opening 212 and into the spaced distance between the second and third magnets. As shown in FIG. 1, when the plugs 302, 304 are in position within the respective openings in the first and third magnets and extend into the opening 212 through the second magnet, the three magnets are co-axially aligned.
The central first magnet 204 is preferably surrounded by a molded plastic material 205 which is molded to form an outer rim 207 around the magnet 204. This rim is preferably heat sealed or adhesively fixed to the housing, e.g., inlet housing member 104, in such a manner as to prevent fluid flow around the magnet 204.
As further shown in FIG. 1, the reduced diameter outlet portion 110 of the housing member 106 is threaded 112 on its circumference thereof to accept a threaded coupling (not shown). The reduced diameter inlet portion 102 has an internally threaded coupling 114 rotatably mounted between a bushing insert 115 mounted within the circumference of the inlet portion 102 and the end of the inlet portion. This threaded coupling 114 is rotatable and allows the device 10 to be connected to a standard externally threaded faucet or hose.
When the device is connected to a fluid source, such as a water source, the fluid flow enters through the inlet portion 102, flows around the interior circumference of the inlet housing 104, around the exterior of the first magnet 202 and into the space 116 between the first and second magnets 202,204. From the space 116 between the magnets, the fluid flows through the channels created between the capped projections 307a-d and into the opening 212 in the second magnet 204. The fluid continues through the central opening 212 outwardly through the channels created between the capped projections 309a-d, into the space 118 between the second and third magnets 204, 206 and into the interior of the housing surrounding the third magnet 206. The fluid, after having traveled around the first magnet 202, through the second magnet 204 and lastly around the third magnet 208, exits the device through the outlet 110.
While the present invention has as a primary goal the magnetic treatment of water, it is also possible to use this device to treat other fluids comprised of non-polar clusters such as: water-based solutions, e.g., milk, syrups, creams, yogurt, etc.; alcohol-based solutions, e.g., alcohol, liquors, beer, etc.; organic and inorganic chemical liquids, solutions and suspensions, including energy-producing liquids, e.g., gasoline, kerosene, diesel fuels, etc., anti-friction liquids, e.g., oil and petroleum jellies, and cooling and heat transfer liquids, e.g., water- or oil-based coolants.
Because the three magnets 202, 204, 206 are positioned with opposite polarity poles adjacent each other, the compressible caps 311a-d, 313a-d mounted on the plugs 302, 304 keep the first and second and the second and third magnets which are magnetically attracted to each other distanced from each other. However, because the caps 311a-d, 313a-d are comprised of resilient elastomeric material, the magnetic attraction of the opposite poles squeezes the interposed caps. Also, because the base members or caps 306a, 308a, 310a, 312a, 314a, 316a on the rods are made of elastomeric material, they, too, can expand to keep a constant force against the outer planar surfaces 211, 213, respectively, of the first and third magnets when the first and third magnets are attracted to the opposite polarity of the second magnet 204. On the other hand, when fluid under pressure flows into the spaces 116, 118 between the first and second and second and third magnets, respectively, the fluid pressure urges the magnets apart, which compresses the base portions or caps 306a-316a and allows the caps 311a-d, 313a-d to expand. The significance of this expansion and contraction within the device will be appreciated more in light of discussions to follow.
It is theorized that the magnetic fluid treatment device of the present invention treats fluid (in this example, water) passing through the device by utilizing the harmonic magnetic fields of the permanent magnets 204, 206, 208 spaced from each other within the device. As best described in conjunction with the illustration of FIG. 1, these magnets create a unique sequence of energy cycles which polarize the fluid comprised of molecular clusters, as they are known, and breaks them apart into smaller molecules.
The positive-negative, positive-negative and positive-negative in-line orientation of the magnets 202, 204, 206 establishes a harmonic magnetic field within the device. Moreover, because the side magnets 202, 206 are not stationarily mounted within the device, rather they are mounted on the elastomeric supports 302, 304, the speed of the water through the device, as well as the pressure of the water into and through the device, cause the magnets 202, 206 to move with respect to the central magnet 204 and, in a sense "to vibrate," and thereby set up a dynamic system within the device. The change in the distance between the magnets affects the amplitude, or the magnetic strength, between the magnets: the closer together the magnets, the higher the amplitude, and this variation in distance due to fluid dynamic forces creates a variable harmonic field within the device.
As the amplitude changes with the fluid pressure, there is established a very special effect within the device which causes the fluid (water) molecular clusters to break apart. As shown in FIG. 1, non-polarized water clusters 220 enter the device at the inlet 102. The clusters proceed around the first magnet 202, and the non-polarized clusters begin to elongate and polarize. This polarization of the non-polarized clusters is first shown at the circumference of the first magnet 202, where the clusters 222 begin to arrange themselves with distinct positive and negative orientations. Thereafter, as the polarized clusters 222 further flow through the variable harmonic field of the device (created by the varying distances between the magnets and the speed of the molecules through the device), the elongated clusters eventually break apart into multiple polarized molecules 224. These polarized molecules 224 can retain their de-polarized state for up to approximately five hours.
It is important to note that of the magnetic amplitudes within the device are functions not only of the strength of the magnets, but also the speed and pressure of the fluid through the device, which affect the distance between the magnets. For example, if the fluid pressure is low, a stronger magnetic field is necessary, because the there is very little free energy in the slow moving low pressure molecules, and thus the cluster reactions with the magnets are slower. As the fluid pressure increases, the free energy of the fluid molecules/clusters increases and the reaction time is quicker, thus permitting lower magnetic strength to be provided. In the present invention, under low pressure conditions, the magnetic attraction between the magnets 202, 204, 206 causes the magnets to draw closer together and thereby increase the magnetic field strength therebetween. Under higher fluid pressure, with more flow between the magnets, the magnets are urged apart and the field strength is decreased.
Accordingly, under the effect of this harmonic variable strength magnetic field of this device there is reduced intermolecular attraction and surface tension, thus making the water more effective as a solvent for minerals contained in topsoil or fertilizer applied to the soil. The magnetic treatment of water by the device further reduces the pH of the water and the harmonically re-polarized and molecules "neutralize" chemicals such as salt (NaCl), chlorine or fluorine, all of which are harmful to plant growth.
The cross-section as shown in FIG. 5 is a second embodiment of the invention of the present application which also provides a harmonic variable strength magnetic field for the polarization, and thus the breaking apart of, non-polarized fluid e.g., (water) clusters which pass therethrough. As shown generally at 20 in FIG. 5, this embodiment of the invention utilizes a longitudinal tube or pipe 400 of non-magnetic material which creates a confined flowpath for the fluid to be treated. This pipe acts a housing for a plurality of spherical isotropic magnets 500. Along the outside of the pipe 400 are a plurality of spaced permanent magnets 600 arranged so that their magnetic polarities are alternating.
In this second embodiment, the permanent magnets 600 are retained in two containers 602, 604, preferably of molded plastic material, positioned opposite each other along the pipe 400. As shown in FIG. 5, a plurality of individual permanent magnets 606a-d, 608a-d are positioned in such a manner that the faces of the magnets having opposite polarity are adjacent each other. For example, in the top container 602, the first pair of magnets 606a,606b have their north and south polar faces opposite and attracting each other. Likewise, the second pair of magnets 606c,606d have their north and south polar faces opposite each other and further have their polar faces opposite the polar faces of opposite polarity in the first pair of magnets 606a, 606b. A magnetically conductive bar 610 bridges the two pairs of magnets and forms a magnetic circuit between the three spaced pairs of magnets and a biasing strip 612 positioned between the bridge 610 and the underside of the cover 603 of the container 602 urges against the bridge and securely holds the magnets in position within the container.
As can be seen in FIG. 5, the lower container 604 also contains two pairs of magnets 608a-d arranged with opposing polarities in the same manner as those magnets in the top housing 602. Furthermore, the polarities of the magnets in the lower housing are opposite the polarities of the magnets diametrically spaced across the pipe in the first container, e.g. the polarity orientation of magnet 606b is opposite to that of magnet 608a.
Inside the pipe 400 are the numerous spherical ceramic isotropic magnets 500 which are maintained in place within the pipe under the influence of the magnetic fields created by the magnets 606a-d, 608a-d opposite each other at the circumference of the pipe.
While the small spherical magnets 500 are necessary to insure that the magnetic strength of the surrounding magnets 606, 608 extends sufficiently into the pipe to affect treatment of fluid flowing through the pipe and around the magnets 500, the real importance of this plurality of spherical magnets is the motion these magnets produce under the influence of the fluid flow in the pipe. As discussed in conjunction with regard to the first embodiment of the invention described above, it is the variable harmonic strength created by the interactive movement of the magnets, in this embodiment the spherical magnets, which causes the non-polar clusters flowing through the spherical magnets to magnetically orient themselves and break apart. Without the spherical magnets within the pipe, all that would exist would be the plurality of magnets surrounding the pipe, not unlike many other patented inventions which attempt to create magnetic fields within pipes with a static--rather than variable--magnetic strength. Furthermore, in the prior types of devices, the magnetic strength is localized at the edge of the pipe. Since the purpose of the present invention is not to attempt to "magnetize" the water flowing therethrough, but rather to polarize the non-polarized clusters and thus cause them to separate or break apart into their molecular components, a static magnetic configuration is insufficient for the purpose of this invention.
When the treatment device 20 of the second embodiment is at rest, i.e. there is no fluid flow therethrough, the magnetic flux is static (i.e., does not vary) along the length of the outside magnets. However, under the influence of fluid passing through the pipe, the spherical magnets are urged closer together or further apart as the case may be in the same manner the magnets of the first embodiment move toward and away from each other under the influence of the fluid flow through the housing. A vibratory motion is created within the mass of spherical magnets that causes the harmonic magnetic strength or amplitude to vary along the length of the pipe surrounded by the magnets 606a-d, 608a-d, thereby causing the non-polarized clusters to polarize during their passage around and between the spherical magnets and to separate into their polarized molecules.
On opposite sides of the top container 602, and projecting downward therefrom are male and female projections 626, 628, respectively. Similar projections 630, 632 extend upwardly from the bottom container 604. The male projections 626, 630 have a lip 634, 636 at the end thereof which is adapted to slip inside and catch within an opening 638, 640 in its corresponding female projection (see FIG. 6), whereby the male and female projections can engage and securely hold each other. Because the containers 602, 604 and the male and female projections extending therefrom are preferably of molded plastic-type material, the male and female projections are resilient enough to slip into and engage each other when the containers are positioned around the pipe.
As further shown in FIGS. 5 and 6, each container 602, 604 has a lid 603, 605, respectively. The lids 603, 605 have openings 607a and b, 609a and b at each end thereof, respectively, which engage prongs 611a and b and 613a and b on the sidewalls of the containers. When the lids are placed over the sidewalls of the containers and the prongs are engaged within the openings, the lids are securely held in position. Furthermore, the biasing member 612, in this case a leaf spring, is interposed between the underside of each lid and each plate member 610. These leaf springs urge against the plate members 610 and hold the plates and magnets thereunder snugly within each container.
Although FIG. 5 shows only two pairs of spaced magnets within each container, it is envisioned that the containers may be enlarged lengthwise to accommodate more pairs of magnets spaced along the pipe 400. Indeed, in a preferred embodiment, three such pairs of magnets are provided in each container. Also, it is permissible to have each set of stack magnets comprise more than two magnets as long as the magnetic poles are alternated (as shown with regard to the pairs in FIG. 5).
Though not shown in the drawings, the containers 602, 604 can also be provided with projections extending from the bottom or sides of each container which extend from each container along and tangential to the pipe 400 in order to help to stabilize the containers when locked by the male and female members around the pipe. Also, even though the bottom of each container adjacent the pipe 400 is flat, as shown in FIG. 6, an accurate projection or projections (again, not shown) may be provided which extend from each flat bottom of each container to partially surround the circumference of the pipe. These accurate projections further help to stabilize the containers around the pipe when engaged together.
Finally, as shown in FIGS. 5 and 6, the containers 602, 604 have pairs of dividing vanes 616a, 616b (not shown in cross section) and 618a, b and 620a, b (not shown in cross section), 622a, b integrally molded therein to position and space the magnets within each container.
Without further elaboration the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service. | An apparatus for magnetically treating fluid comprised of non-polar molecular clusters, such as water, flowing therethrough is provided. The apparatus includes a housing having an inlet and an outlet, which housing is adapted to permit fluid flow therethrough between the inlet and the outlet within the interior thereof. In the two embodiments disclosed, a magnet arrangement is positioned either totally within or partially surrounding and associated with magnets within the housing to provide a harmonic magnetic field within the housing. The strength of the harmonic magnet field is variable along the housing in response to fluid flow therethrough. In addition, a method of magnetically treating non-polar fluids comprised of cluster molecules, such as water, is disclosed. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to an offset duplicator. In particular, the invention relates to an offset duplicator which is capable of process color offset printing.
The printing industry has reached high levels of sophistication over the past several years as many businesses and other fields have placed increasingly greater demands on the quality of their printed materials. From the industry's early beginnings in straightforward black-and-white reproduction, printing has followed a gradual development in terms of techniques, quality, and output which has led to the current state of the printing art. Users of printed materials cover a wide range of interests and fields. Virtually every commercial and noncommercial entity uses the print media for a variety of purposes.
In order to satisfy the need for printed materials a wide variety of printing apparatus has been developed. Such equipment has typically been developed to satisfy particular printing needs. Thus a typewriter may be used to provide a single, high quality copy, but it would not generally be used if a number of copies were required. In such cases, a photocopier would typically be used to provide a relatively limited number of high quality copies, whereas a mimeograph machine or a spirit copier might be used to provide a relatively limited number of less expensive, but poorer quality, copies.
When large numbers of high quality copies are required, some type of offset printing equipment is typically used. The features desired by a particular user largely determine the particular type of printing equipment required for use on a job. Thus, a user of a large number of copies, who did not need to reproduce full color items, would conventionally use an offset duplicator.
As used herein, the term "full color" refers to items which include arbitrary colors, such as photographs, rather than items which may include a plurality of colors, such a line copy. While line copy may be printed in multiple colors, the separation processes required for "full color" or "process color" printing are not needed.
When factors such as printing in full color, cost per copy, number of copies per plate, and speed of operation are critical, as they are in a large printing operation, the type of equipment available to perform the required services becomes limited, and the cost of such equipment becomes quite large. For example, to fill the need for printing a large number of items in full color, the only printing equipment heretofore available has been the rotary offset printing press. Such equipment is capable of producing a fine quality product and is the type of equipment which is generally used to print full color.
Rotary offset color presses of the type in common use include many features which insure that they will have a very high quality product. Unfortunately, these items result in a very high acquisition cost. By way of example, in order to be able to spread a thin layer of ink onto the printing plate used in such a press, a so-called "tower" is located over each plate cylinder the press. Within that tower, there are typically more than fifty ink rollers. Their purpose is to thin out the viscous ink used in printing. A very thin layer of ink is required on the printing plate, because the plate used for each color is comprised of a very dense arrangement of dots. Those skilled in the art recognize that in a full color or "process color" printing press, the original item to be reproduced first undergoes a "color separation" procedure in which the colors of the original are separated into constituent colors which, when recombined, result in the colors of the original. Each of the constituent colors is printed separately. The physical separation is accomplished through the use of a screen having a very dense pattern of dots. The higher the dot density, the closer together the different colored dots will be on the ultimate print, and consequently the higher the resolution of the ultimate print.
Thus, the rotary offset color presses heretofore known have had to include a mechanism for insuring that when a high dot density screen is used in preparing the printing plates, i.e. one typically having from about 150 to about 200 dots or "lines" per inch, the ink applied to the plates will not fill in the spaces between the image dots. As should be obvious, if the ink layer were not applied to the plate as a very thin film, a muddled print would result.
Naturally, the preparation of the plates with the high resolution described above, the so-called "high etch" plates, involves a very exacting and precise process. This further increases the expense of producing high quality printed output on an offset press.
An additional feature of the conventional rotary offset color press is the use of so-called "transfer cylinders" to move sheets of paper from one print head to another. The transfer cylinders insure very accurate registration of sheets of paper at different locations within the press. Such registration is required in order to insure accurate color reproduction.
Unfortunately, there have been a variety of applications in which color printing has heretofore been desirable, but too costly, due to the cost of conventional color offset printing presses. The user who has not needed absolutely accurate color reproduction could not heretofore find a machine capable of process color offset printing, providing relatively good color, simple operation, and inexpensive purchase and maintenance costs.
In addition, the cost of setting up a job for a conventional rotary offset color press has been so high that it has not heretofore been economical to print small jobs in full color. Thus, the user who needs a relatively small number of color copies, i.e. less than about 2500 copies, has typically found it too expensive to have the job run by a print shop.
Instead, the user of a relatively small number of copies has been limited to a much less expensive device, such as an offset duplicator, and has had to give up color reproduction. The term "duplicator" is used herein to refer to printing equipment of the type described more fully in U.S. Pat. No. 2,821,911 entitled INTERRUPTER FOR ROTARY OFFSET PRINTING MACHINE; U.S. Pat. No. 2,846,220 entitled SHEET FEEDER FOR PRINTING PRESS; U.S. Pat. No. 2,859,692 entitled SHEET DELIVERY MEANS FOR ROTARY OFFSET PRINTING PRESSES; U.S. Pat. No. 2,890,884 entitled MULTIPLE SHEET EJECTING MECHANISM; U.S. Pat. No. 2,899,202 entitled OFFSET PRINTING MACHINE AND SHEET GAGE; U.S. Pat. No. 2,915,970 entitled INKING AND DAMPENING MEANS FOR AN OFFSET PRINTING MACHINE; and U.S. Pat. No. 2,929,321 entitled INK FOUNTAIN ROLL. Each of the foregoing U.S. patents is incorported herein by reference.
While an offset duplicator is an offset printing apparatus, and it uses many of the same principles as the rotary offset color press described above, it is not designed for process color printing. Thus, while more than one color may have heretofore been printed on a single item using an offset duplicator, as described more fully in U.S. Pat. No. 2,845,860 entitled TWO-COLOR OFFSET PRINTING PRESS, full color printing on an offset duplicator has not been accomplished heretofore. In other words, the different colored inks were not separated by a color separation process, because an offset duplicator is inherently incapable of providing the fine ink layer on a plate and the accurate sheet transfer that the rotary offset color press is designed for. Heretofore, no one had designed a color separation printing process which could be used in an offset duplicator to bring its simplicity, and lower price, to the public.
SUMMARY OF THE INVENTION
A process color offset printing duplicator manufactured in accordance with the present invention includes a plurlity of offset duplicator heads, each of which prints a single color onto a single piece of sheet stock. The duplicator heads are arranged serially, such that the print output of the first duplicator head is fed into the second duplicator head for printing the second color. Using a novel color subtractive process designed to compensate for the inherent limitations of an offset duplicator, plates for the process color offset printing duplicator of the present invention can be constructed. In one embodiment of the invention, three print heads, which print cyan, yellow, and magenta, are used. A preferred embodiment of the invention would include a fourth duplicator head which prints black, in order to increase the contrast of the final product.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is an illustration of the equipment used to expose the negatives which are used to make the plates required for use with the process color offset printing duplicator of the present invention;
FIG. 2 is a side view of the process color offset printing duplicator of the preferred embodiment of the invention with much of the detail removed for clarity;
FIG. 3 is a side view of a duplicator head of the type used in the process color offset printing duplicator of the preferred embodiment of the invention;
FIG. 4 is a side view of a portion of the adjustment used on the final ink feeding roller of the color offset printing duplicator of FIG. 2;
FIG. 5 is a side view of the registration plate used on the plate cylinder of the present invention; and
FIG. 6 is a top view of the registration plate shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the present invention, a process color offset printing duplicator 40, is shown in FIG. 2. The process color offset printing duplicator 40 includes a plurality of duplicator heads 42, 44, 46, 48 to provide good quality color prints. In order to accomplish that result, a series of plates, each of which is used as an offset plate in a particular one of the duplicator heads, must first be produced. Accordingly, while the present invention is a process color offset printing duplicator, in order to gain a complete and proper understanding of the invention, reference must first be made to FIG. 1 which illustrates the method of preparing the plates, i.e. the so-called "color separation" process, used in the process color offset printing duplicator 40 of the present invention.
Referring to FIG. 1, the color separation process begins with an object 10, which may be line copy, artwork, a photograph, a half-tone, or some similar object, placed into a holder 12 on a copyboard 14. The object 10 is affixed with appropriate registration indices in order to permit the ultimate registration of elements, such as acetate elements, which are used in a proofing step, or printing plates, which are used in the ultimate duplicating step.
Typically, the object 10 is illuminated by at least two remotely spaced light sources 18, 20. Light reflected from the object 10 is collected by an optical system 22, which includes lenses 21, 23, or a similar device which must be capable of focusing the reflected light onto a series of planar elements, each of which will be referred to by reference numeral 24. The original planar element 24 which is used is a ground glass plate on which the image of the object 10 is brought into focus. Then, the ground glass plate is replaced by a film holder 24 which is adapted to hold a sheet of sensitive panchromatic film. For example, if a three-color process, without black ink for contrast, is being used, the panchromatic film must be sensitive to the colors which will be used in the process. Typically, in a three-color process, the inks used will be cyan, yellow, and magenta. Accordingly, the film used to prepare the duplicator plates must be sensitive to the "negatives" of those colors, i.e. red, blue, and green. Kodak Graphic Arts Film, No. 2568, has been found to be suitable for use in this process.
In order to expose each of the three sheets of film needed for the three plates, a film sheet is placed into the film holder 24 and a filter 30 is placed into a filter holder 32 in the path of the light being reflected by the object 10. In addition, a pre-angled dot screen 34 is typically placed in front of the film holder 24 in order to improve the visual clarity and definition of the ultimate image.
Continuing with the present example, a series of three exposures will be made. Since the focusing has already been achieved using the ground glass element, no further focusing is required when the ground glass element is replaced by the film holder as the planar element 24. A pre-angled dot screen 34, which typically comprises an array of elliptical dots with a density of from about 120 to 150 dots per linear inch, is placed in contact with the sheet of film in the film holder 24, such that each sheet of film will be exposed through the dot screen 34. The dot density of the screens used to prepare each of the negatives in a particular process must, of course, be identical.
The step of preparing the negative for the cyan plate proceeds with a red filter 30, such as a Kodak No. 25 filter, in the filter holder 32. Depending upon the object being copied, varying light intensities, lens openings, and exposure times may be used. In a typical exposure, a light intensity of about 64,000 foot candles is present at the optical system 22, and a lens opening of f/22 is used. A typical exposure time for preparing the negative for the cyan plate is about 50 seconds. Typically, the angle of dots on the dot screen 34 will be 105 degrees.
Similarly, the step of preparing the negative for the yellow plate proceeds with a blue filter 30, such as a Kodak No. 47 filter, in the filter holder 32, an exposure time of about 60 seconds, and a dot screen angle of 90 degrees; and the step of preparing the negative for the magenta plate proceeds with a green filter 30, such as a Kodak No. 58 filter, in the filter holder 32, an exposure time of about 70 seconds, and a dot screen angle of 75 degrees. If additional contrast is desired, a black printing plate can be utilized in addition to the three plates already described. The negative for the black printing plate can be prepared using a yellow filter 30, such as a Kodak No. 8 filter, in the filter holder 32, an exposure time of about 25 seconds, and a dot screen angle of 75 degrees.
Following the separate exposure steps, each film sheet is developed in a high quality developer, such as Naccolith 611, with the operator carefully monitoring the gradually darkening Stouffer scale. Depending upon the desired output, varying darkening stages can be used. In a typical process, the developing will be stopped, using a stop bath, when the No. 1 dot on the Stouffer scale becomes solid black. This is a useful guide for evaluating the exposure time needed by each of the exposure steps. The negative is then fixed, washed, and dried in accordance with standard photographic processes.
Next, appropriate masking sheets for the three colors used in the process are aligned using the registration indices that had been placed on the original artwork. A so-called "proofing" step, to determine the precise color quality of each negative can be accomplished, if desired. Such a step involves mounting each negative on a color key sheet and photographically preparing a separate color keyed member, or acetate, for each of the negatives. Thereafter, the acetates are mounted in layers and registered with respect to each other, and the relative color content of the composite product is tested. If any color revisions are needed, they may be done at this point in the process. However, for the purpose of explaining the present invention, it suffices to say that these steps may be accomplished, if desired.
For each of the negatives, a suitable plate, of the type used in subtractive printing processes, is prepared. The preparation of each plate involves exposing the plate through one of the negatives, such that the exposing light removes or "burns" away all of the plate's surface, except where the negative image is located. In those locations, the material used for the ultimate contact printing step will remain. An exposure step is accomplished for each of the negatives in order to produce a plate which is used in the process color offset printing duplicator of the present invention. As will be obvious to those skilled in the art, the step of preparing the plates is identical to the proofing step described above, except that the plates are not transparent and the acetates are.
Referring now to FIG. 2, the process color offset printing duplicator 40 is shown. The preferred embodiment of the process color offset printing duplicator 40 comprises a series of four duplicator heads 42, 44, 46, 48. As used herein the term "duplicator head" refers to the portion of a duplicator machine, of the type heretofore known, which does the actual printing of ink onto a sheet of stock fed through the process color offset printing duplicator 40. The process color offset printing duplicator 40 further comprises a sheet feeding mechanism 50, of the type well known in the art. The sheet feeding mechanism 50 includes a suction feeder 52 which lifts sheets of paper 54 and places them on a first delivery table 56. The printing process involves printing a separate ink color on each sheet in each of the duplicator heads 42, 44, 46, 48 in a manner to be explained hereinafter and then depositing the completed work into a hopper 58.
The process color offset printing duplicator 40 is driven by a motor 60, which turns a drive shaft 62. A series of transmission units 64 drive chains 66, and the chains 66 power the duplicator heads 42, 44, 46, 48. The duplicator heads 42, 44, 46, 48 are substantially identical, so a description of the first duplicator head 42, will serve to describe the elements of the other duplicator heads 44, 46 and 48.
Referring, therefore, to FIG. 3, the first duplicator head 42 comprises a plate cylinder 68, around which a first printing plate 70 is mounted by means of registration pins 72. The registration pins 72 are machined to fit registration holes formed in the plate 70. They differ from the holding pins normally found on standard offset duplicators in that the registration pins 72 are specifically fitted to the registration holes on the plate 70 without any play, whereas the holding pins of the prior art have a substantial amount of play in the holes which are preformed in standard plates. As will be understood by those of ordinary skill in the art, while the duplicator heads 42, 44, 46, 48 of FIG. 2 may be identical, in a typical printing operation, the plate 70, mounted on the first duplicator head 42, will be different from the plates mounted on the second, third, and fourth duplicator heads 44, 46, 48.
With continued reference to FIG. 3, the first duplicator head 42 further comprises a water supply 74 and an ink supply 76. The water supply 74 comprises a reservoir, such as the inverted bottle 78, which provides a flow of water 80 to water feed rollers 82, 84, 86, 88. The feeding roller 82 receives water 80 from the reservoir, and feeds it onto roller 84. Roller 84 feeds water onto roller 86, and roller 86 feeds water onto roller 88. Finally, roller 88 feeds water onto the plate 70.
The plate 70 is prepared in a manner, well known in the art, which makes its non-image portions, i.e. its non-printing portions, receptive to water, but not to grease or ink. Accordingly, the water 80 which roller 88 feeds onto the plate 70 will be received by the non-image portions of the plate 70.
Similarly, ink 90 from the ink supply 76 is fed onto the plate 70 by a series of ink feeding rollers 92, 94, 96, 98, 100, 102. Oscillator rollers 104, 106 serve to help spread the ink evenly over the ink feeding rollers. The plate 70 is, of course, prepared in a manner well known in the art, which makes its image portions, i.e. its printing portions, receptive to grease or ink, but not to water. Accordingly, the ink 90 which roller 102 ultimately feeds onto the plate 70 will be received by the image portions of the plate 70, but not by its non-image portions. Accordingly, the pressure of the final inking roller 102 upon the plate 70 must be light enough to prevent the roller 102 from forcing ink into the non-image areas of the plate 70. This light pressure between the final inking roller 102 and the plate 70 constitutes an important difference from what is found in duplicators of the type known in the prior art. In the present invention, the light pressure is designed to help to spread a thin film of ink 90 onto the plate 70. On the other hand, duplicators of the type heretofore known were not used for printing process color. Accordingly, they use a relatively high pressure between their final ink roller and their plate. In view of the fact that the plate used in a standard offset duplicator is not exposed through a dot screen of the type used for color separation, the high pressure is not a problem. When a standard offset duplicator is used for making half-tones, any extra ink imparted by the inking roller serves merely to degrade the half-tone image. However, in a color printing process of the type with which the present invention is used, any extra ink will prevent proper color printing from taking place.
Referring to FIG. 4, the final ink roller 102 is shown. The final ink roller 102 rotates around a shaft 104. The shaft 104 passes through a housing 106 which is attached to a bracket 108 by means of a pressure adjustment means, such as adjustment screw 110.
Referring back to FIG. 3, the presence of ink 90 on the image portions of the plate 70 and water 80 on its non-image portions results in the transfer of an offset image, i.e. a reversed image, onto a blanket roller 112 which rotates in contact with the plate 70. A piece of sheet stock, such as a sheet of paper 114, which is fed into the duplicator head 42 on the first delivery table 56, will receive an inked image from the blanket roller 112. The sheet of paper 114 is held in contact with the blanket roller 112 by an impression cylinder 116 having a series of paper holding grippers 118. Following the printing of the image onto the sheet of paper 114, the sheet of paper 114 is moved by a feeding mechanism, such as a chain gripper apparatus 118, which includes grippers 120 which receive the sheet of paper 114 and transport it to the next delivery table (not shown).
As will be recognized by those skilled in the art, when a plurality of colors are printed in a full color process, the quality of the ultimate print will be determined to a large extent by the registration of the colors with respect to one another. In the process color offset printing duplicator 40 of the present invention, the two types of registration which are important are vertical registration and horizontal registration. The term "vertical registration" refers to the registration of the print along the vertical axis of a sheet of paper, whereas the term "horizontal registration" refers to the registration of the print along the horizontal axis of a sheet of paper.
Vertical registration is controlled by the timing of each sheet of paper 114 as it is grabbed by grippers 122, which are part of the impression cylinder 116, upon entering into each duplicator head. With continued reference to FIG. 3, a stop mechanism 124 at the end of the deliver table 56 receives each sheet of paper 114 before the sheet 114 is grabbed by the grippers 122 of the impression cylinder 116. The step mechanism 124 may include a micrometer adjustment 126, or similar means, for accurately aligning the top edge of the sheet 114, so that its position, as it is grabbed by the grippers 122, is accurately determined.
Horizontal registration is controlled by the side-to-side location of the sheet 114. Horizontal registration in an offset duplictor is typically controlled by a pair of paper guides, such as the guide 128 which is visible in FIG. 3. As each sheet 114 enters into the paper pick-up area adjacent the stop mechanism 126, its presence is signalled when it lifts a microswitch 130, causing the paper guides on either side of the sheet 114 totake action which aligns the sheet 114. In a standard duplicator, of the type heretofore known, the paper guides travel towards one another, thereby squaring up the sheet 114.
In the present invention, it is critical for horizontal registration to have one edge of each sheet of paper 114 located in the same relative position as it enters each of the duplicator heads 42, 44, 46, 48. Accordingly, the sheet guides are adjusted to urge each sheet of paper toward one side of the delivery table. That is preferably accomplished by using the type of sheet guides which include grippers 132, 134 to pull the paper 114 to one side of the delivery table 56, rather than the type which push each sheet toward the center of the delivery table. Alternatively, the sheet guides on one side of the delivery table can be adjusted so that they push each sheet much harder than the sheet guides on the opposite side of the delivery table. In any event, it is critical to horizontal registration to have one side of each sheet fixed in a known location as it enters each of the duplicator heads. The most accurate horizontal registration results from using paper guides which pull the sheet 114 to one side. However, if push guides are used, accurate horizontal registration can be obtained if one of the guides is either fixed in position or is adjusted to move with less force than the other guide.
As will be obvious to those skilled in the art, it is very important that the sheet 114 be properly aligned as it is picked up by the impression cylinder in each of the duplicator heads 42, 44, 46, 48. Accordingly, the paper guides and the stop mechanism in each duplicator head is independently adjustable.
In addition to the vertical alignment provided by the stop mechanisms and the horizontal alignment provided by the paper guides, additional features of the preferred embodiment of the invention which help to guarantee proper alignment include gross vertical alignment means, such as Allen screws 136, 138 which attach the plate cylinder 68 to its shaft 140. The Allen screws 136, 138 permit rotational movement of each of the plate cylinders of the various duplicator heads on their respective shafts in order to allow each plate cylinder to be registered with respect to each of the other plate cylinders. Once each plate cylinder is registers, it is fixed into position on its shaft. It is contemplated that this type of registration will be carried out when a machine is placed into service, and periodically thereafter, if necessary.
In order to accomplish the original alignment, a test sheet is printed with ink in the first and second duplicator heads 42, 44, and the plate cylinder in the second duplicator head 44 is aligned with respect to the plate cylinder in the first duplicator head 42. Then, the same thing is done with the plate cylinder in the third duplicator head 46, and, finally, with the plate cylinder in the fourth duplicator head 48. In that manner, the original vertical registration can be accomplished.
In addition to the original vertical registration, it is necessary to perform a "set up" or "make ready" for each print run. In the "set up", the stop mechanism for the sheets entering each duplicator head is adjusted in order to compensate for irregularities in the manner in which the sheets were originally cut, i.e. if they were not properly squared when cut. In addition, the horizontal adjustments, made using the paper guides, are performed.
If further adjustment, i.e. to remove skew is required, a fine adjustment means, such as the micrometer adjustable registration plate 142, shown in FIGS. 5 and 6 is used. The registration plate 142 holds the registration pins 54. The registration plate 142 is attached to the plate cylinder 68 by means of screws 144 having shafts 146 narrower in diameter than holes 148 bored through the registration plate 142. The plate cylinder 68 is tapped to receive the screws 144, and the heads of the screws 144 are recessed into openings 146 formed in the surface of the registration plate 142. Micrometer adjustment means 150, 152 permit very fine adjustment of the registration plate 142 on the plate cylinder 68 when the screws 144 are loosened. After such adjustments are completed, the screws 144 are tightened to hold the registration plate 142 in the proper position for a particular run. For example, the micrometer adjustment means 150 is used for fine horizontal alignment, and the micrometer adjustment means 152 is used for fine vertical alignment. Together, they can be used to correct skew errors.
Synchronization of the various duplicator heads 42, 44, 46, 48 with respect to one another is important to prevent paper jams which would result if the duplicator heads 42, 44, 46, 48 did not rotate at the same rate. As shown in FIG. 2, the synchronization of rotation of the various duplicator heads 42, 44, 46, 48, with respect to one another, is assured through the use of chain drives 66 which rotate each of the parts of the various duplicator heads 42, 44, 46, 48 simultaneously when they are driven by a drive shaft 62, which in turn is driven by motor 60. | A process color offset duplicator uses a plurality of duplicator heads arranged serially to print full process color. The duplicator heads are adapted to apply a thin layer of ink onto plates held on their respective plate cylinders, in order that plate cylinders which are prepared using a dot screen can be used. The plate cylinders further include registration pins, whereby tha various ones of said plates can be mounted in relative alignment on different ones of said plate cylinders. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority 35 U.S.C. §119 to European Patent Publication No. EP 12196778.0 (filed on Dec. 12, 2012), which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments relate to a battery system and a method for producing a battery system. The battery system has a plurality of battery cells, a covering plate provided on and/or over the battery cells to cover the battery cells, and cell connectors configured to electrically connect battery cells. The cell connectors are arranged in receiving regions of the covering plate.
BACKGROUND
[0003] Cell connectors may be installed for connecting, by way of example, in a parallel or series manner, battery cells of a battery system having a plurality cells, in other words, of high voltage batteries. The cell connectors must be connected in an electrically conductive manner to suitable connection points, typically the cell poles, of in each case at least two battery cells. The cell connectors are mainly screwed to the cell poles.
[0004] German Patent Publication No. DE 19847190 A1 discloses an injection moulded plate having conductor rails cast therein for connecting several batteries. The conductor rails in each case represent a connection to two batteries. The conductor rails are connected to electrodes of the batteries by way of screws.
[0005] German Patent Publication No. DE 10 2010 035 114 A1 discloses a battery unit, having adjacent cell units, wherein each cell unit comprises several accumulator cells and wherein electrodes of the cell units are connected by way of bus-bars. Bus-bar equipping spaces are embodied on an upper housing part and said bus-bar equipping spaces comprise openings for cathode connectors and anode connectors. Bus-bars are provided in the bus-bar equipping spaces and are connected to the electrode connectors of the cells, in particular are welded thereto.
[0006] Screw connections are encumbered with disadvantages. For instance, the loading force of the screw connections may thus decrease in the course of time which leads to an increased transfer resistance between cells and cell connectors and consequently to increased resistance and increased temperature. The exterior dimensions of the battery system also increase as a result of using screws having a screw head. Furthermore, the production of a battery system of this type is problematic since the screw heads must be easily accessible for a screwing tool.
[0007] Solutions using non-screwed cell connectors cannot be efficiently produced in mass production and/or they cannot generally be produced in a process reliable manner. It is thus difficult by way of example to handle several cell connectors that are only placed on a covering plate.
SUMMARY
[0008] In accordance with embodiments, a battery system and a method for producing a battery system is provided and which is simple and reliable to produce whilst having compact dimensions.
[0009] In accordance with embodiments, a battery system may include at least one of: a plurality of battery cells; a covering plate provided on and/or over the battery cells to cover the battery cells, and cell connectors configured to electrically connect battery cells and which are arranged in receiving regions of the covering plate, wherein the receiving regions have a first holding surface as a first planar section of the covering plate, and which is on a first face of the covering plate that faces the battery cells, and a second holding surface as a second planar section that is on the second face of the covering plate, and which is remote from the battery cells, and wherein the cell connectors in each case are held between the first holding surface and the second holding surface.
[0010] Embodiments relate to a method for producing such a battery system that includes at least one of: inserting the cell connectors between the first and second holding surfaces of the covering plate; placing the holding plate on the battery cells after inserting the cell connectors; and connecting the cell connectors by, for example, a welded process, to the poles of the battery cells.
[0011] Embodiments relate to a method for producing such a battery system that includes at least one of: inserting cell connectors between first and second holding surfaces of a covering plate; arranging the covering plate over a plurality of battery cells; and establishing an electrical connection between the cell connectors and poles of the battery cells, wherein: the covering plate includes receiving regions each having the first holding surface at a face of the covering plate that is adjacent to the battery cells, and the second holding surface at a lower face of the covering plate that is remote from the battery cells; and the cell connectors respectively extend through the receiving regions and are respectively held between the first holding surface and the second holding surface.
[0012] In accordance with embodiments, the covering plate may have receiving spaces that are delimited by holding surfaces both towards the battery cells as well as in the opposing direction typically towards the exterior of the battery system. In this way, the cell connectors may be arranged in the receiving regions of the covering plate and may be secured in their position by way of the holding surfaces. The term “holding surface” in accordance with embodiments refers to a planar, but three dimensional section of the covering plate, not just the two dimensional surface of the corresponding section. Embodiments having holding surfaces renders it possible to fit a covering plate in accordance with embodiments at an earlier stage prior to the assembly on battery cells using cell connectors. The cell connectors are also held in position without additional positioning devices during the production of the battery system. The correct position of the cell connectors and possible lines that are connected thereto may be tested by way of example prior to assembling the covering plate on the battery cells and may be corrected if necessary.
[0013] The holding surfaces must cover a sufficiently large surface of the respective receiving region in order to achieve a secure holding of the cell connectors and in order to prevent the cell connectors falling out by way of example during rotation of the covering plate. It is preferred, therefore, that each holding surface covers one of: greater than 3%, 5%, 10%, 20% or 30% of the surface of its receiving region.
[0014] In accordance with embodiments, the first holding surfaces may be formed in each case by way of a first extension and a second extension that lies opposite the first extension, so that the cell connectors on the first face of the covering plate that faces the battery cells are connected to the battery cells on edges of the cell connectors by the first and second extensions and said cell connectors may be electrically connected in the centre of the cell connectors to poles of the battery cells. By virtue of the fact that the laterally lying extensions form the first holding surface that faces the battery cells, it is possible by way of example to weld the cell connectors to the poles of the battery cells centrally. The word “laterally” in the framework of this application is always understood as relating to the narrow sides of the covering plate, in other words, on sides that lie perpendicular to the first face that faces the battery cells and the second face of the covering plate that is remote from the battery cells.
[0015] In accordance with embodiments, the first extensions may be shorter in size than the second extensions. Accordingly, the extensions may not have an identical length. As a consequence, it is possible to install and remove a cell connector on sides of the shorter extensions in a simpler manner and to improve the manner in which the cell connector is held by way of the longer extension.
[0016] In accordance with embodiments, the receiving regions may be arranged in at least two rows immediately adjacent to one another. This construction is advantageous for a typical sequence of in particular similar battery cells whose positive and negative poles come to lie behind one another, in other words forming rows.
[0017] In accordance with embodiments, the first and second extensions may be arranged in a first row of receiving regions in a manner that is symmetrical, i.e., mirrors, the first and second extensions in a second row of receiving regions that is adjacent to the first row. The mirror symmetry relates to a plane perpendicular to a straight connecting line between a receiving region of the first row and a receiving region of the second row. By way of example, the left-hand extension of a row of receiving regions that lies on the left-hand side in the battery system may be shorter than the extension of the same receiving regions that lies on the right-hand side and the left-hand side extension of a row of receiving regions that lies on the right-hand side in the battery system may be longer than the extension of the same receiving regions that lies on the right-hand side. As a consequence, it is possible to install and remove cell connectors in the covering plate, in each case by way of the side of the shorter extension in a relatively effortless manner as long as the covering plate is not connected to the battery cells. As soon as, by way of example, the cell connectors are connected to the poles of the battery cells, neither the cell connectors may be removed from the covering plate nor may the covering plate be detached from the battery cells in a non-destructive manner, since it is not possible to detach the covering plate by way of the short extensions of the first holding surface as a result of the geometric shape.
[0018] In accordance with embodiments, the second holding surfaces may include in each case an assembly opening, so that the cell connectors are accessible from the exterior through the assembly openings. A cell connector may in particular be welded to a cell pole by virtue of this assembly opening.
[0019] In accordance with embodiments, the second holding surfaces in each case may be folded away by way of a hinge. As a consequence, in the case of a second holding surface that is folded away it is particularly simple to insert a cell connector into the receiving region. A clip contact may be provided, by way of example, to close a second holding surface that is folded together.
[0020] In accordance with embodiments, at least one insertion opening may be provided on and/or over a front face of the covering plate for laterally inserting at least one cell connector. As a consequence, as an alternative or in addition to further possibilities for inserting cell connectors it is possible to insert cell connectors laterally into the receiving regions of the holding plate.
[0021] In accordance with embodiments, at least one insertion opening for inserting a cell connector may be arranged perpendicular to one of the rows of receiving regions and/or that at least one insertion opening for inserting a cell connector is arranged in the direction of a row of receiving regions. In other words, the cell connectors may be inserted, by way of example, in the direction of the rows of receiving regions so that a whole row of cell connectors preferably including electrically non-conductive separating elements may be pushed collectively into the receiving regions. Alternatively or in addition to, cell connectors may also be pushed in perpendicular to a row of receiving regions. Separating elements, such as the covering plate, may be provided at an earlier stage between the receiving regions.
[0022] In accordance with embodiments, a battery system may also include a voltage tapping unit having measuring lines, wherein the measuring lines are connected to the cell connectors in a detachable manner, in particular, by way of clamp connections.
[0023] In accordance with embodiments, the ends of the measuring lines may include contact surfaces and the contact surfaces are clamped in each case between a holding surface and the cell connector. Measuring lines of a unit for tapping voltages, by way of example, of a cell monitoring unit may be pre-positioned in this manner on the battery cells in the respectively allocated receiving region at an earlier stage prior to the assembly of the covering plate. For this purpose, one of the holding surfaces, preferably the first holding surface, is used in order to clamp in a contact surface of the measuring line.
[0024] In accordance with embodiments, a battery system may include a voltage tapping unit having measuring lines, the measuring lines being fixed to the covering plate in a detachable manner, in particular, by way of holding elements that include the covering plate. As a consequence, the measuring lines by way of example are secured by way of holding elements on the covering plate in addition to the contact surfaces being clamped in the receiving regions.
[0025] In accordance with embodiments, the cell connectors may be inserted between the first and second holding surfaces of the covering plate for the purpose of producing a battery system in accordance with embodiments, subsequently the covering plate is placed on and/or over the battery cells and subsequently the cell connectors are welded to the poles of the battery cells.
[0026] In accordance with embodiments, measuring lines, if present, may be secured to the covering plate prior to inserting the cell connectors. The covering plate that is already pre-equipped with measuring lines and cell connectors is placed on to the battery cells and subsequently the cell connectors are welded to the poles of the battery cells.
DRAWINGS
[0027] Embodiments will be illustrated by way of example in the drawings and explained in the description below:
[0028] FIG. 1 illustrates a front schematic illustration of a battery system in accordance with embodiments.
[0029] FIG. 2 illustrates a three-dimensional schematic illustration of a battery system in accordance with embodiments.
[0030] FIG. 3 illustrates a front schematic illustration of a battery system in accordance with embodiments.
[0031] FIG. 4 illustrates a front schematic illustration of a battery system in accordance with embodiments.
[0032] FIG. 5 illustrates a front schematic illustration of a battery system in accordance with embodiments.
DESCRIPTION
[0033] FIG. 1 illustrates a battery system in accordance with embodiments, and which may include a plurality of battery cells 1 . A covering plate 2 is provided on and/over the battery cells 1 to cover the battery cells 1 . The covering plate having a plurality of cell connectors 3 that are in electrical communication with poles 8 of the battery cells 1 , and are mechanically connected thereto, for example, by a weld to establish such electrical communication. The cell connectors 3 may be arranged in open receiving regions of the covering plate 2 that are delimited in each case by a first holding surface 4 on the first face of the covering plate 2 that faces the battery cells 1 , and by a second holding surface 5 on the second face of the covering plate 2 that is remote from the battery cells 1 . The cell connectors 3 are held in each case between the first holding surface 4 and the second holding surface 5 . The first holding surface 4 is formed by way of two lateral extensions 6 , 7 of which the first extension 6 is shorter than the second extension 7 on the opposite lying side of the receiving region.
[0034] Corresponding receiving regions are illustrated in FIG. 1 by way of a first pole 8 arranged on the left hand-side and a second pole 8 arranged on the right hand-side, wherein for the sake of clarity, the corresponding reference numerals are disclosed in each case only on one side of the illustration. The extensions 6 , 7 of the first holding surface 4 that is allocated to a left-hand row of receiving regions are arranged in a manner that mirrors, i.e., is symmetrical, the extensions 6 , 7 of a first holding surface 4 that is allocated to a right-hand row of receiving regions so that the shorter first extension 6 is located in the left-hand row to the left of the respective pole 8 and in the right-hand row to the right of the respective pole 8 . The second holding surfaces 5 may have assembly openings 11 , by way of which it is possible, by way of example, to establish an electrical connection of the cell connectors 3 to the poles 8 using a welding device.
[0035] FIG. 2 illustrates how the receiving regions that are allocated to a pole 8 that is illustrated in each case on the left-hand side form a first row 9 and the receiving regions that are allocated to a pole 8 that is illustrated in each case on the right-hand side form a second row 10 . The covering plate 2 has insertion openings 13 on one of the end sides 12 . Cell connectors 3 may be inserted, by way of example, in each case alternating with non-electric separating elements in the direction of the first and second rows 9 , 10 of receiving regions and are held in their position by the first holding surfaces 4 and second holding surfaces 5 .
[0036] As is illustrated in FIGS. 3 and 4 , the second holding surfaces 5 in particular may be equipped with a hinge 18 so that they may be folded up and render it possible to insert the cell connectors 3 in a particularly simple manner. A latching mechanism may be used for closing the second holding surfaces 5 .
[0037] As illustrated in FIG. 5 , a voltage tapping unit 14 may be arranged on and/or over the covering plate 2 . The voltage tapping unit 14 may have an electrical connection to the poles 8 of the battery cells 1 by way of measuring lines 15 , the ends of which measuring lines form the contact surfaces 16 . The ends may be allocated to the cells. For this purpose, the contact surfaces 16 may in each case be clamped between a first holding surface 4 and a cell connector 3 . The measuring lines 15 may be fastened in addition by way of holding elements 17 to the covering plate 2 .
[0038] In order to produce a battery system in accordance with embodiments, measuring lines 15 of a voltage tapping unit 14 may be arranged on and/or over the covering plate 2 , by way of example, by way of holding elements 17 and/or by way of inserting contact surfaces 16 in the receiving regions for cell connectors 3 . The cell connectors 3 are subsequently inserted between the first and second holding surfaces 4 , 5 of the covering plate 2 . The covering plate 2 is then placed on and/or over the battery cells 1 and subsequently the cell connectors 3 are connected by way of assembly openings 11 to the poles 8 of the battery cells 1 .
[0039] The term “coupled” or “connected” may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms “first,” “second,” etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.
[0040] Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments may be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.
LIST OF REFERENCE SIGNS
[0000]
1 Battery Cell
2 Covering Plate
3 Cell Connector
4 First Holding Surface
5 Second Holding Surface
6 First Extension
7 Second Extension
8 Pole
9 First Row
10 Second Row
11 Assembly Opening
12 End Side
13 Insertion Opening
14 Voltage Tapping Unit
15 Measuring Line
16 Contact Surface
17 Holding Element
18 Hinge | A battery system and a method for producing a battery system. The battery system has a plurality of battery cells, a covering plate provided on and/or over the battery cells to cover the battery cells, and cell connectors configured to electrically connect battery cells. The cell connectors are arranged in receiving regions of the covering plate | 8 |
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of materials technology, and more particularly to processes for depositing a cladding material by melting a powdered material on a substrate surface with an energy beam.
BACKGROUND OF THE INVENTION
[0002] Selective laser melting (SLM) and electron beam melting (EBM) are known additive manufacturing processes whereby a powdered feed material is melted and fused into a homogeneous mass by the application of an energy beam in a layer-by-layer process for forming a three dimensional object. These processes are useful for creating intricate shapes by melting small filler material particles (e.g. 20-100 microns) with a small diameter beam at focus (e.g. 50 microns) with precise computer controlled movement of the beam. However, these processes tend to be slow and expensive, and they produce only small grain sized equiaxed and polycrystalline microstructures. Moreover, they are limited to depositing material onto a top surface of a component where the component does not project above the processing plane, since the powder is typically applied to the processing plane by a wiper action which spreads the feed material across the processing plane. Accordingly, improved powder deposition processes are needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The invention is explained in the following description in view of the sole drawing that shows an embodiment of an improved selective laser melting process.
DETAILED DESCRIPTION OF THE INVENTION
[0004] The present inventors have developed an improved process for depositing a powdered feed material onto a substrate surface which overcomes many of the limitations of prior art SLM and EBM processes. In addition to the application of heat energy with an energy beam as is provided in known processes, the present invention advantageously incorporates the use of vibratory mechanical energy. The vibratory mechanical energy may be applied to the powder and/or to the substrate before, during and/or after the application of the beam energy in various embodiments of the invention, as described more fully below.
[0005] The sole FIGURE illustrates aspects of the invention. A substrate material 10 is supported in a bed of powdered material 12 within a container 14 . A layer 16 of the powdered material is distributed over a surface 18 of the substrate 10 , and is being melted by an energy beam 20 being traversed over the surface 18 in the direction of the arrow. The melted powder forms a traveling melt pool 22 which then cools and solidifies to form a layer of clad material 24 on the substrate 10 . The energy beam may be a light beam, a laser beam, a particle beam, a charged-particle beam, an electron beam, a molecular beam, etc. The powdered material is typically a metal alloy, but may include ceramic, flux, plastic, glass, composite, and/or other powdered ingredients and mixtures thereof.
[0006] In one embodiment, the layer 16 of the powdered material is distributed over the surface 18 by vibratory mechanical energy applied to the bed of powdered material 12 . The vibratory mechanical energy 27 may be imparted to the bed of powdered material 12 by an electro-mechanical transducer 26 in contact with a surface the container 14 . Alternatively, a similar transducer 28 may be used in direct contact with the substrate 10 to apply the energy 29 , or a pencil head shaker 30 may be submerged into the bed of powdered material 12 to apply the energy 31 . The vibratory mechanical energy functions to loosen or “fluidize” the bed of powdered material 12 and to cause it to form a horizontally level upper surface 32 . The height of the support structure 34 for the substrate 10 may be adjusted or the quantity of the powdered material within the container 14 may be controlled such that the level upper surface 32 of the bed of powdered material 12 forms a desired thickness for layer 16 over the substrate surface 18 .
[0007] The vibratory mechanical energy may be applied at a single frequency or over a range of frequencies, including from low frequencies (e.g. 50 Hz or less) to ultrasonic frequencies (above 18 kHz). The use of vibratory mechanical energy to move powder onto the processing plane advantageously eliminates the need for a wiper arm as is commonly provided in prior art SLM machines. This makes it possible to apply clad material 24 onto a substrate 10 having a portion 36 which extends above the working plane of the surface 18 being coated.
[0008] The vibratory mechanical energy may be provided intermittently or continuously as desired to achieve a desired distribution of the powdered material over the surface 18 . Continuous powder delivery has the potential for significantly increasing the speed of the deposition process by allowing the powder delivery and melting to proceed concurrently. Moreover, directional solidification of the deposited clad material 24 is now possible by continuously feeding and melting material over a broad area, such as by applying heat energy with a diode laser or by rapidly scanning a high power laser beam. The application of vibratory mechanical energy to the bed of powdered material 12 will result in some preheating of the powder, in particular if ultrasonic energy is used, thereby reducing an amount of heat that must be applied via the beam 20 in order to achieve melting. A chill plate 38 may be utilized to influence the direction of heat transfer from the melt pool 22 in order to facilitate the directional solidification of the clad material 24 , including the deposition of single crystal material. The chill plate may further incorporate sides (e.g. of zirconia) extending above its surface that laterally insulate the deposit made thereon. By discouraging lateral heat conduction, these insulating features would further enhance uniaxial heat extraction and ensure directional solidification.
[0009] The vibratory mechanical energy may be applied as the weld pool 22 material solidifies in a manner effective to break up dendrites that may be forming during the solidification, thereby providing grain refinement and improved mechanical properties to the deposited clad material 24 . Effective vibration frequencies may vary depending upon the alloy of the substrate 10 . For example, magnesium alloys have been cited to benefit from frequencies up to about 16 Hz while steels have been cited to benefit from frequencies up to about 400 Hz. Furthermore, a component may benefit from application of resonant frequencies that are dependent on its specific geometry. To this end, a vibration sensor(s) 40 may be useful in detecting such resonances and thereby providing feedback to adjust vibrator speeds that optimize vibrational effect.
[0010] The vibratory mechanical energy may be applied after the clad material 24 is solidified in a manner effective to introduce stress relief. For example, large amplitudes of vibration that induce stresses approaching the fatigue limit of the material being processed can effect significant relief of residual stresses.
[0011] In embodiments where the clad material 24 includes a difficult to weld superalloy material, the layer of powdered material 16 may include a powdered flux material, as described in commonly owned United States patent application publication number US 2013/0136868 A1, incorporated by reference herein. The melted flux material will form an uppermost layer of slag material as part of the deposited clad material 24 , and the slag material must most normally be removed prior to the deposition of the next layer of clad material. In such embodiments, vibratory mechanical energy may be applied in a manner effective to release the slag from the substrate 10 by mechanically breaking the layer of slag and loosening it from the underlying deposited superalloy material. Frequencies effective in achieving such detachment are likely similar to those common in mechanical tools such as chipping hammers and needle guns (e.g. up to hundreds on Hz) but may beneficially extend up to up to the kilohertz range.
[0012] While the vibratory mechanical energy may be applied to the powder and/or to the substrate before, during and/or after the application of the beam energy, it need not be applied in the same manner, at the same frequency, or from the same location during these different phases of the deposition process. For example, preheating of the powder may be accomplished with ultrasonic energy applied by the pencil head shaker 30 until a desired powder temperature is achieved, then movement of the powder may be further stimulated by the application of vibratory mechanical energy at a lower frequency applied by the transducer 26 , and then still lower frequency vibratory mechanical energy may be applied by transducer 28 during and/or after the melting and solidification steps. Standing or moving waves may be induced in the bed of powdered material 12 or the substrate 10 in order to accomplish movement of powder, control of dendrite formation, slag removal and/or stress relief. The process and powder bed may or may not be further assisted by fluidizing gas, inert cover gas or general process space vacuum.
[0013] In a further embodiment, powdered material 12 may include at least two distinct types of particles, such as different size particles, different shaped particles, different density particles, etc. The vibratory mechanical energy may be controlled to preferentially react with one type of particle in favor of another type of particle, such as using different frequencies of vibratory mechanical energy to preferentially heat particles of metal alloy more than particles of flux material. In another example, metallic alloy and ceramic particles may be moved onto substrate surface 18 by using multiple frequencies of mechanical vibratory energy simultaneously; then the different types of particles may be segregated into respective layers on the surface 18 by further vibratory mechanical energy of a single frequency which promotes the “floating” of the ceramic above the metallic alloy. Similarly, relatively smaller particles may be induced to migrate into cracks or openings in the surface 18 while relatively larger particles are retained on the surface 18 .
[0014] While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims. | A method for depositing clad material ( 24 ) onto a substrate ( 10 ) by melting a layer of powdered material ( 16 ) using an energy beam ( 20 ), and also applying vibratory mechanical energy ( 27, 29 and/or 31 ). The vibratory mechanical energy may be applied before, during or after the melting and solidification of the powdered material in order to preheat the powder, to distribute powder over a top surface ( 18 ) of the substrate, to control the formation of dendrites in the clad material as the melt pool ( 22 ) solidifies, to remove slag, and/or to perform stress relief. Simultaneous application of beam energy and vibratory mechanical energy facilitates the continuous deposition of the clad material, including directionally solidified material. | 1 |
[0001] This invention is a Continuation-in-part of U.S. patent application Ser. No. ______, filed ______, based on International Patent Application Serial No. PCT/CA01/01358, filed Sep. 27, 2000.
FIELD OF THE INVENTION
[0002] This invention relates to methods for secondary processing of plant material and in particular for the recovery of valuable products such as fiber including beta-glucan, starch, protein and ethanol solubles from plant material containing starch and fiber. In particular, the invention relates to the preparation of high viscosity beta-glucan products through methods including alcohol slurrying, as well as enzyme treatments and/or sonication/sonification processing steps.
BACKGROUND OF THE INVENTION
[0003] Plant materials including grains contain a number of valuable components such as starch, protein, mixed linkage 1-4, 1-3 beta-D-glucan (hereinafter “beta-glucan” or “BG”), cellulose, pentosans, tocols, etc. These components, and products derived from these components, have many food and non-food uses. Consequently, there is a strong and continued industry interest for the processing of such plant materials.
[0004] Dietary fibre is generally accepted as having protective effects against a range of diseases predominant in Western developed countries including colorectal cancer, coronary heart disease, diabetes, obesity, and diverticular disease. The term ‘dietary fiber’ is commonly defined as plant material that resists digestion by the secreted enzymes of the human alimentary tract but may be fermented by the microflora in the colon. Increased fiber consumption is associated with lowering total serum cholesterol and LDL cholesterol, modifying the glycemic and insulinemic response and protecting the large intestine from disease. BG, a non-starch polysaccharide, is a water-soluble component of dietary fibre and thus contributes such health benefits.
[0005] BG has been extensively researched and has been found to have a number of positive health benefits including reducing cholesterol levels, regulating glycemic response, and immune system enhancement. In particular, consumption of beta-glucan is believed to increase the viscosity of intestinal contents, thus slowing down the movement of dietary cholesterol and glucose as well as bile acids towards the intestinal walls leading to reduced absorption. These benefits have led to the U.S. Food and Drug Administration (FDA) approving a health claim indicating that four daily servings of oat products containing 0.75 grams/serving of soluble oat fibre may reduce the risk of heart disease.
[0006] Cardio-Vascular Disease (CVD) is considered the principal cause of death in all developed countries, being responsible for 20% of deaths worldwide. 1 In the United States 59.7% of people had some form of CVD in 1997, 2 and in Canada, 8 million people are estimated to be suffering from CVD. 3 An estimated 102 million American adults have total blood cholesterol levels of 200 milligrams per deciliter (mg/dL) and higher. Of these, about 41 million have levels of 240 mg/dL or above. In adults, total cholesterol levels of 240 mg/dL or higher are considered high risk. Levels from 200 to 239 mg/dL are considered borderline high risk. Low-density lipoprotein (LDL) cholesterol levels of 130 mg/dL or higher is associated with increased risk of coronary heart disease and occurs in approximately 45% of Americans. Approximately 18% of Americans have LDL cholesterol levels of 160 mg/dL or higher. High LDL cholesterol levels are associated with a higher risk of coronary heart disease (CHD).
[0007] Not only is CVD the number one cause of death, it also is the most expensive disease in most developed countries. In the U.S. in 2002, the disease cost $329.2 billion in direct and indirect costs. Direct costs were $199.5 billion, with drug costs totalling $31.8 billion. 4 Canadian cost statistics are only as recent as 1993, but at this time total CVD costs were $19.7 billion. Direct costs amounted to $7.3 billion, with drugs accounting for $1.6 billion of this total. 5 These statistics demonstrate the importance of reducing the risk of CVD through dietary means. Increased consumption of soluble fiber, especially through the incorporation of beta-glucan concentrate as an ingredient into a variety of food products can contribute significantly towards this goal. However, it is crucial for the beta-glucan to have high-viscosity characteristics to achieve the claimed health benefits since there is growing evidence that links health benefits of beta-glucan to its viscosity.
[0008] Until now, BG has been restricted to high value markets such as cosmetics, medical applications, and health supplements due to the high cost of extraction, which has prohibited its use as an ingredient in the food industry. Current food products in the marketplace contain low concentrations of BG, requiring consumption of unrealistic amounts of such products in order to satisfy the parameters of the health claim.
[0009] In the extraction of BG from grains, a number of investigations at laboratory and pilot scale have been carried out on the fractionation of these grains including barley. In general, conventional processes utilize water, acidified water and/or aqueous alkali (i.e. NaOH, Na 2 CO 3 or NaHCO 3 ) as solvents for the slurrying of whole cracked barley, barley meal (milled whole barley) or barley flour (roller milled barley flour or pearled-barley flour). These slurries are then processed by techniques such as filtration, centrifugation and ethanol precipitation to separate a slurry into various components. This conventional process for barley fractionation has a number of technical problems and whilst realizing limited commercial feasibility has been limited by the expense of the product particularly for food applications.
[0010] In particular, technical problems arise because the beta-glucan in barley flour is an excellent water-binding agent (a hydrocolloid) and as such, upon addition of water (neutral, alkali or acidic environment), the beta-glucan hydrates and tremendously thickens (increases the viscosity) the slurry. This thickening imposes many technical problems in the further processing of the slurry into pure barley components (i.e. starch, protein, fiber, etc.), including clogging of the filter during filtration and inefficient separation of flour components during centrifugation.
[0011] Usually, these technical problems are minimized, if not eliminated, by the addition of a substantial quantity of water to the thick/viscous slurry in order to dilute and bring the viscosity down to a level where further processing can be carried out. However, the use of high volumes of water leads to several further problems including increased effluent water volumes and the resulting increased disposal costs. In addition, the beta-glucan, which solubilizes and separates with the supernatant (water) during centrifugation, is usually recovered by precipitation with ethanol. This is done by the addition of an equal volume of absolute ethanol into the supernatant. After the separation of precipitated beta-glucan, the ethanol is preferably recovered for recycling. However, recovery requires distillation, which is also a costly operation from an energy usage perspective.
[0012] Furthermore, the aqueous alkali solubilization and subsequent precipitation of beta-glucan in ethanol (and centrifugation steps in between) is believed to contribute to the breakdown of the beta-glucan chains that results in a lower-grade, lower-viscosity beta-glucan product.
[0013] Still further, the use of these past techniques also is believed to support both the growth of microorganisms and increased enzyme activity that may contribute to hydrolysis of the beta-glucan chains. These problems are particularly manifested in larger batch operations where it may become difficult to control enzyme activity and thus lead to problems of batch-to-batch consistency.
[0014] Accordingly, there is a need for efficient processes for the fractionation of grains that overcomes the particular problems of slurry viscosity and water-usage. Moreover, there is a need for a process that provides a high purity, high-viscosity beta-glucan product in a close to natural state wherein the BG product has decreased starch and protein content.
[0015] Thus, there continues to be a need for techniques which improve the yield and quality of beta-glucan products extracted from the cell walls of grains including oats and barley that overcome problems of water-based extraction techniques.
[0016] A review of the prior art reveals that beta-glucan products having improved rheological properties have not been disclosed.
[0017] Moreover, sonication/sonification/ultrasonication/ultrasonification (hereinafter “sonication”, “ultrasonication” and “US”) techniques have not been applied to processes for the extraction of beta-glucan from barley and oats in an alcohol slurry.
[0018] For example, while the use of ultrasonication has been described in the production of konnyaku powder (See Kimura, T., Sugahara, T and Goto, M. 2000. Improvement of a method for production of konnyaku powder using ultrasonic treatment. Journal of the Japanese Society for Food Science and Technology (Nippon Shokuhin Kagaku Kogaku Kaishi). 47 (8):604-612), this reference is silent with respect to the extraction of beta glucan.
SUMMARY OF THE INVENTION
[0019] In accordance with the invention, a fractionation technology produces BG concentrate that maintains high quality functional characteristics including improved viscosity characteristics. In the context of this invention, improved viscosity characteristics of BG relates to the increased viscosity or high viscosity of solutions of fiber residues of BG prepared in accordance with the methodologies of the invention in comparison to the viscosity characteristics of BG solutions prepared in accordance with the prior art wherein both solutions incorporate equivalent concentrations of BG.
[0020] The process greatly reduces production time and improves process efficiency, therefore realizing significant cost savings in the extraction and purification of BG. High BG varieties of grains increase the yield of BG extracted thus also reducing the overall cost of extraction and purification.
[0021] More specifically and in accordance with the invention, there is provided a method of preparing a beta-glucan (BG) product comprising the steps of:
[0022] a) mixing a flour and an alcohol to form a flour/alcohol slurry;
[0023] b) separating a fiber residue from the alcohol, wherein the fiber residue has a high BG content;
[0024] c) subjecting the fiber residue from step b) to at least one additional treatment step, the additional treatment step including mixing the fiber residue from step b) with an alcohol to form a fiber residue/alcohol slurry and subjecting the fiber residue/alcohol slurry to a sonication, protease or amylase treatment step or a combination of a sonication, protease or amylase treatment step and thereafter separating a final fiber residue from the fiber residue/alcohol slurry.
[0025] Furthermore, and in various embodiments the method includes a sonication treatment step, a sonication and protease treatment step, a sonication and amylase treatment step, a protease and amylase treatment step or a sonication, protease and amylase treatment step.
[0026] The invention also provides a method of preparing high viscosity BG products whose viscosities can be characterized as high viscosity by comparing solubilized BG fiber residues prepared in accordance with the above methodology in comparison to the viscosities of solubilized BG fiber residues derived from prior art methods.
[0027] More specific embodiments of the invention include providing a final fiber residue having a composition wherein the BG content is greater than 25% (w/w, dry matter basis) for particular varieties of source flour and greater than 35% (w/w, dry matter basis) for other varieties of source flour. Furthermore, the invention provides a method wherein the final fiber residue has a composition having less than 40% (w/w, dry matter basis) starch content and preferably less than 20% (w/w, dry matter basis) starch content.
[0028] The invention also provides fiber residues having a high beta-glucan (BG) content and a high viscosity, the high viscosity characterized wherein a 0.5% (w/w) BG solution prepared from the fiber residue has a viscosity greater than 200 mPa·s, greater than 350 mPa·s or greater than 500 mPa·s at a shear rate of 12.9 s −1 at 20° C.
[0029] In one embodiment the BG content of the fiber residue is preferably greater than 35% (w/w).
[0030] The method preferably utilizes pearled grains wherein the pearling is greater than 20% and more preferably 25-40%. Flour particle sizes are preferably less than 250 microns.
[0031] When subjected to a protease or amylase treatment, it is preferred that the fiber residue/alcohol slurry is incubated with 0.1-3% (w/w, protein or starch weight basis) of a protease or amylase and wherein the protease may be selected from any one of or a combination of papain, bromelain, microbial protease and the amylase may be selected from any one of or a combination of microbial, plant or animal amylase.
[0032] When subjected to a sonication treatment step it is preferred that the fiber residue/alcohol slurry be sonicated for 3-15 minutes at a power level of 2.5-3.5 kW or at a power selected to minimize fragmentation of BG.
[0033] In another embodiment, the invention provides for the use of ultrasonication to produce a beta glucan product high in beta glucan content from a slurry of a flour and an alcohol.
[0034] In a more specific embodiment, the invention provides a method of preparing a high viscosity beta-glucan product comprising the steps of:
[0035] a) mixing a flour in aqueous ethanol to produce a first flour-alcohol slurry;
[0036] b) filtering the flour-alcohol slurry to produce an alcohol filtrate and a first fiber residue;
[0037] c) mixing the first fiber residue with aqueous ethanol to form a fiber residue/alcohol slurry;
[0038] d) filtering the fiber residue/alcohol slurry to produce a second alcohol filtrate and a second fiber residue containing high viscosity beta-glucan;
[0039] wherein either or both of the flour/alcohol or fiber residue/alcohol slurries are subjected to an ultrasonication treatment.
[0040] In further embodiments, the aqueous alcohol in steps a and c is 8-100% (w/w), 40-95% (w/w) or 50% (w/w) and/or the flour:aqueous ethanol is 1:5 to 1:8 (w/w).
[0041] In a still further embodiment, the invention provides a method of controlling the degree of fragmentation of beta-glucan (BG) within an aqueous alcohol BG fiber residue solution by subjecting the aqueous alcohol BG fiber residue solution to a sonication treatment wherein the ratio of water:alcohol in the solution is selected on the basis of the desired fragmentation of beta glucan within the solution wherein a lower water:alcohol ratio is selected to decrease the level of fragmentation of beta glucan within the solution and a higher water:alcohol ratio is selected to increase the level of fragmentation of beta glucan within solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The invention is described with reference to the following drawings wherein:
[0043] [0043]FIG. 1A is an overview of the methodologies of the invention for preparing improved beta-glucan products.
[0044] [0044]FIG. 1B is an overview of preferred methodologies for preparing improved beta-glucan products.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The invention is described with reference to FIGS. 1A and 1B. FIG. 1A is an overview of the methodologies of the invention for preparing improved beta-glucan products and FIG. 1B is an overview of preferred methodologies for preparing improved beta-glucan products.
[0046] With reference to FIG. 1A, pearl grain flour 1 is mixed with alcohol 2 to form a flour/alcohol slurry which may include optional sonication 5 , protease 6 and amylase treatments. The slurry is filtered 3 to separate fiber residue (FR 1 ) from the filtrate 4 . The mixing and filtering steps are repeated as desired (pathways B-E) again with optional sonication 5 , protease 6 and amylase 7 treatments to produce fiber residues FR 2 -FR 6 and filtrates b-e.
[0047] More specifically and with reference to FIG. 1B, a preferred methodology 10 for preparing BG fiber residues is described as general steps I-VI and detailed steps 18 - 78 . Step I refers to a first ethanol wash, Step II refers to a second ethanol wash, Step III refers to a sonication step, Step IV refers to a protease treatment step, Step V refers to an amylase treatment step and Step VI refers to a final ethanol wash. It is understood that in accordance with the invention that Step I can be combined with any combination of Steps II-V with it being preferred that Step VI complete the process.
[0048] The following describes three studies undertaken in the preparation of high viscosity BG fiber residues from pearled grain flours of CDC-Candle barley, HiFi oats and Antoine to determine the effect of individual processing steps on the yield of fiber residue (FR) as well as the purity of the beta-glucan within the FR.
[0049] Materials and Methodology
[0050] Barley and oat flours were prepared by pearling whole barley or oat groats (10-35%) and milling the pearled grains to <250 μm using a pin mill.
[0051] Study #1: The Effect of Various Processing Steps of FIG. 1B on the Viscosity of Fiber Residues Prepared at A) a Laboratory Scale and B) a Pilot Plant Scale.
[0052] A) Laboratory Scale Study
[0053] The following fibre residues were prepared in the lab according to selected steps in FIG. 1B using 100 g of flour as a starting material:
[0054] Blank (ethanol washing) (FIG. 1B—Steps I, II, and VI)—Two washings in 50% ethanol (30 min each), recovery of fiber residue and final wash in absolute ethanol.
[0055] US (Ultrasonication) (FIG. 1B—Steps I, II, III and VI)—Two ethanol washings as similar to blank, recovery of fiber residue, US treatment for 10 min in 50% ethanol, recovery of fiber residue and final absolute ethanol wash. One methodology of ultrasonication is explained in greater detail below.
[0056] PT (protease treatment) (FIG. 1B—Steps I, II, IV and VI)—Two ethanol washings as similar to blank, recovery of fiber residue, protease treatment for 8 hours in 50% ethanol, recovery of fiber residue and final absolute ethanol wash.
[0057] US+PT (US and PT) (FIG. 1B—Steps I, II, III, IV and VI)—Two ethanol washings as similar to blank, recovery of fiber residue, US treatment for 10 min, protease treatment for 8 hours, recovery of fiber residue and final absolute ethanol wash.
[0058] PT+TT (PT and thermostable alpha-amylase treatment (TT)) (FIG. 1B—Steps I, II, IV, V and VI)—Two ethanol washings as similar to blank, protease treatment to the fiber residue for 8 hours, recovery of fiber residue, TT treatment to the fiber residue for 1 hour in 50% ethanol, recovery of fiber residue and final absolute ethanol wash.
[0059] US+PT+TT (US, PT and TT treatments) (FIG. 1B—Steps I, II, III, IV, V and VI)—Two ethanol washings as similar to blank, US treatment for 10 min, recovery of fiber residue, protease treatment to the fiber residue for 8 hours, recovery of fiber residue, TT treatment to the fiber residue for 1 hour, recovery of fiber residue and final absolute ethanol wash.
[0060] In addition, a high purity BG sample (78% w/w, dry wt basis) obtained from barley flour was prepared in the laboratory using aqueous alkali extraction and ethanol precipitation methodology of the prior art (referred to hereinafter as LAB gum). This process consists of mixing flour and water and adjusting the pH to an alkali pH (preferably pH 9) through addition of sodium carbonate. The extraction is continued for 1 hour at 55° C. The pH of the mixture is adjusted to pH 4.5 to precipitate protein, which is then separated from the solution by centrifugation. BG in the supernatant is precipitated through the addition of absolute ethanol and the BG is recovered by centrifugation and subsequently dried.
[0061] Beta-Glucan Solution Preparation
[0062] The dried fiber residue (beta glucan concentrate) was then used in the preparation of aqueous beta glucan solutions (0.5%, w/w). The amount of dried fiber residue required was calculated to contain 100 mg of beta-glucan based on the beta-glucan content of the fiber residues determined according to the Megazyme procedure (Megazyme International Inc., Bray, Ireland). A beaker containing 20 g water was placed on a heater-stirrer. The fiber residue was mixed into the water with vigorous stirring. Heat stable amylase (35 μL of Termamyl 120 L obtained from Novozyme, Toronto, Ontario) enzyme was added to hydrolyze remaining starch and minimize the influence of starch on subsequent viscosity measurements.
[0063] The beaker was covered with A1-foil and the contents of the beaker was quickly brought to boiling and stirred on the hot plate for ≧1 hr at ˜80° C. The solution was then cooled, weight adjusted with distilled water to compensate for any loss during heating to a final beta glucan concentration of 0.5% (w/w), stirred for about 30 sec and transferred into pasteurized 50 mL tubes. The tubes were then centrifuged (Centra MP4, International Equipment Company, USA) at 4000 rpm for 10 min and the supernatant used for viscosity measurements.
[0064] Viscosity Measurements
[0065] The viscosity of the supernatant was measured using a PAAR Physica UDS rheometer (Glenn Allen, Va.). The supernatant (7.05 g±0.01 g) was pipetted directly into a DG 27 cup and viscosity was determined at 1-100 rpm (shear rate=1.29-129 s −1 ) and 20° C. in the Controlled Shear Rate mode.
[0066] B) Pilot Scale Study
[0067] The pilot scale study prepared Candle barley and Antoine oat fiber residues using 5 kg and 200 kg batches of flour as the starting material in accordance with Steps I, II, III, V and VII as described above and with reference to FIG. 1B. Viscosity was determined according to the same methodology as for the laboratory study.
[0068] Study #2: Yield, Recovery (BG) and Composition of Fiber Residue as Influenced by the Degree of Pearling and Ultrasonication—Laboratory Study
[0069] Candle barley and HiFi oat flours were used in this study. Grain pearling was performed to 10-35%. Fiber residues were prepared in the laboratory by ultrasonication according to Steps I, II, III and VI.
[0070] Fiber residue yield is based on the weight of fiber residue relative to the weight of the starting flour. BG recovery is based on the weight of BG in the recovered fiber residue relative to the weight of BG in the starting flour. The BG, protein and starch content of the raw and recovered fiber residue were determined by standard techniques (AACC 2000) and is the wt % of each within the recovered fiber residue.
[0071] Study #3: Viscosity of Beta-Glucan in Oat and Barley Fiber Residues as Influenced by Ultrasonication When Carried Out in Aqueous-Ethanol Slurry and 100%-Aqueous Solution
[0072] Candle barley and HiFi oat flours were used in this study. Grain pearling was performed to 30%. Fiber residues were prepared in the laboratory by ultrasonication according to Steps I, II, III and VI and viscosity determination was performed as described above. In order to perform the ultrasonication of BG in 100% aqueous media, the dry fiber residue obtained through Steps I, II, III and VI was solubilized in water to prepare a uniform solution and ultrasonication performed at 80% amplitude for 10 minutes.
[0073] Results and Discussion
[0074] Study #1 (Tables 1 and 2)
[0075] Viscosity of fresh solutions (containing 0.5% BG (w/w)) (Table 1) prepared in the laboratory from fiber residues obtained from the above methodologies as in FIG. 1B (two steps of 50% ethanol wash (blank) and various combinations of US, protease treatment (PT) and amylase treatment (TT) steps) were determined. The viscosities of two other beta-glucan gums (commercial oat gum and barley LAB gum) obtained with conventional aqueous alkali extraction are also shown for comparison purposes. The commercial oat gum had a purity 58% BG (w/w, dry matter basis) and the high viscosity barley LAB gum had a purity of 78% BG (w/w, dry matter basis).
[0076] The viscosities of Candle barley, HiFi oat, and Antoine oat fiber residues as shown in Table 1 were superior to high viscosity LAB gum and commercial oat gum. As expected, the fiber residue solutions exhibited pseudo-plastic or shear-thinning behaviour, where the viscosity drops with increased shear rate from 12.9 s −1 to 129 s −1 . At 129 s −1 the viscosity of fiber residues approached that of LAB gum.
[0077] The data in Table 2 shows the aqueous solution viscosities of fibre residue (combination of US and TT treatments) obtained in the pilot plant from Candle barley and Antoine oat flours. These results are comparable to those obtained from the laboratory study indicating that there is no damage to BG viscosity during scale-up using industrial equipment.
[0078] Study #2 (Tables 3 and 4)
[0079] Tables 3 and 4 show yield, recovery (BG) and composition of fiber residue as influenced by the degree of pearling and ultrasonication for HiFi Oat and Candle Barley, respectively.
[0080] The yield of fiber residue (flour dry weight basis) showed a marginal decrease (<1.5%) as the degree of pearling increased. The recovery of beta-glucan ranged from 80-94%. The β-glucan content of the fiber residue increased by up to 2.4% as the degree of pearling increased. With an increased level of pearling, protein content decreased in the fiber residue for both oat and barley, whereas the starch content increased in barley but was marginally changed in oat.
[0081] Thus, an increased level of pearling does not show a significant advantage from a yield perspective. However, the level of pearling showed a noticeable effect on the color/brightness of the fiber residue wherein samples at greater than 25% pearling were substantially brighter than samples with less than 20% pearling.
[0082] Sonicated samples showed substantially higher (up to 12%) beta-glucan content as compared to the blank samples (produced without US). As shown in Table 3, the Hi-Fi flour sample prepared from 35% pearled grain resulted in a fiber residue containing 28.4% (w/w) beta-glucan whereas the comparable sonicated fiber residue had 40.1% (w/w) beta glucan. Similar improvements in BG concentration were observed with Candle barley upon sonication as shown in Table 4.
[0083] These results demonstrate the effectiveness of ultrasonication in concentrating beta-glucan with high recovery. It is believed that ultrasonication is particularly effective in breaking up the plant cell wall structure thereby enhancing the separation of beta-glucan from the rest of the cell materials in a form that is close to native state.
[0084] Study #3 (Table 5)
[0085] Table 5 shows the effect of sonication on the viscosities of BG solutions when carried out in aqueous ethanol slurry and 100% aqueous solutions.
[0086] Fiber residues prepared by ultrasonication in 50% ethanol media had comparable viscosities to those of the blanks, indicating that ultrasonication is not detrimental to beta-glucan quality in the presence of ethanol. However, if ultrasonication is applied in the absence of ethanol but with 100% water, where beta-glucan is completely hydrated and solubilized, then there was a significant decrease in viscosity indicating that the beta-glucan molecule in aqueous media is highly sensitive to damage, perhaps being fragmented upon sonication. Thus, the use of sonication is also effective as a tool in controlling the viscosity of the beta-glucan by selection of the slurry media. That is, selection of a high water-content slurry media results in a lower viscosity product through the sonication treatment whereas a high alcohol content slurry media results in a higher viscosity product.
TABLE 1 Aqueous solution viscosity of fiber residue obtained in the laboratory from Candle barley, Hi Fi and Antoine oat flours 1 . Concentration of solution used for viscosity measurements is 0.5% beta-glucan by weight. Viscosity (mPa · s) at 20° C. Variety and Treatment @ shear rate 12.9 s −1 @ shear rate 129 s −1 Candle barley Blank 617 168 US 530 147 PT 490 141 US + PT 525 140 PT + TT 396 125 US + PT + TT 500 147 HiFi oat Blank 736 145 US 960 171 PT 551 136 US + PT 443 117 PT + TT 646 126 US + PT + TT 714 146 Antoine oat Blank 700 136 US 586 115 PT 468 117 US + PT 442 124 PT + TT 520 104 US + PT + TT 526 110 LAB Gum 2 192 108 Commercial Oat Gum 3 33 31
[0087] [0087] TABLE 2 Aqueous solution viscosity of fiber residue obtained in the pilot plant from Candle barley and Antoine oat flours 1 . Concentration of solution used for viscosity measurements is 0.5% beta-glucan by weight. Viscosity (mPa · s) at 20° C. Variety and Treatment @ shear rate 12.9 s −1 @ shear rate 129 s −1 5 kg batch Candle barley 368 109 US + TT Antione oat 538 124 US + TT 200 kg batch Candle barley 557 140 US + TT Antione oat 553 132 US + TT LAB Gum 2 192 108 Commercial Oat Gum 3 33 31
[0088] [0088] TABLE 3 Yield, Recovery (BG) and Composition of HiFi oat fiber residue Treat- ments (Degree of β-Glucan Composition of fiber residue pearl- in flour, Yield 1 Recovery 2 (%, w/w, dry matter basis) ing, %) % (w/w) % % β-Glucan Protein Starch Without Ultrasonication (Blank) 15.2 5.9 19.7 91.6 28.8 20.4 27.1 23.9 5.9 18.9 88.7 29.2 20.7 29.6 30.0 6.2 19.4 85.0 28.0 20.3 30.7 35.3 6.0 18.8 85.5 28.4 19.8 28.2 With Ultrasonication 15.2 5.9 13.6 84.9 38.6 18.2 18.1 23.9 5.9 13.5 85.8 39.8 19.1 16.3 30.0 6.2 13.2 84.2 41.2 18.4 18.8 35.3 6.0 12.5 80.1 40.1 17.9 15.4
[0089] [0089] TABLE 4 Yield, Recovery (BG) and Composition of Candle Barley fiber residue Treat- ments (Degree of β-Glucan Composition of fiber residue pearl- in flour, Yield 1 Recovery 2 (%, w/w dry matter basis) ing, %) % (w/w) % % β-Glucan Protein Starch Without Ultrasonication (Blank) 10.2 7.1 32.7 91.1 19.8 13.4 47.6 15.4 7.0 31.8 90.4 20.3 12.3 47.1 24.7 7.0 31.5 94.3 21.2 10.3 48.5 29.7 6.9 31.7 91.8 20.5 11.3 49.6 35.0 6.9 31.3 93.1 20.9 10.4 48.5 With Ultrasonication 10.2 7.1 22.2 87.0 27.9 13.0 33.4 15.4 7.0 21.7 90.5 29.8 12.3 36.8 24.7 7.0 21.5 91.9 30.2 10.2 34.2 29.7 6.9 21.4 90.2 29.7 11.1 36.1 35.0 6.9 20.8 90.3 30.3 10.1 39.9
[0090] [0090] TABLE 5 Viscosity of fiber residue obtained from Candle barley and HiFi oat flours 1 after processing with and without sonication. Viscosity (mPa · s) at 20° C. Variety and Treatment @ shear rate 12.9 s −1 @ shear rate 129 s −1 Candle Blank (no sonication) 530 147 Ultrasonication of flour 617 168 slurry in aqueous EtOH media Ultrasonication of aqueous 25 14 beta-glucan solution HiFi Blank (no sonication) 736 145 Ultrasonication of flour 960 171 slurry in aqueous EtOH media Ultrasonication of aqueous 32 12 beta-glucan solution LAB Gum 2 192 108 Commercial Oat Gum 3 33 31 | This invention relates to methods for secondary processing of plant material and in particular for the recovery of valuable products such as fiber including beta-glucan, starch, and ethanol solubles from plant material containing starch and fiber. In particular, the invention relates to the preparation of high viscosity beta-glucan products through methods involving sonication/sonification and enzymes. | 2 |
RELATED APPLICATIONS
The present application claims priority from U.S. Provisional Patent Application No. 60/776,693, filed on Feb. 27, 2006, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The field of the invention relates to an improved process for preparing montelukast and salts thereof.
BACKGROUND OF THE INVENTION
(R-(E))-1-(((1-(3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(2-(1-hydroxy-1-methylethyl)phenyl)propyl)thio)methyl)cyclopropaneacetic acid sodium salt, also known by the name montelukast sodium, is represented by the structural formula I below:
Montelukast sodium is a leukotriene antagonist, and is thus useful as an anti-asthmatic, anti-allergic, anti-inflammatory and cytoprotective agent. Montelukast sodium is currently indicated for the treatment of asthma and allergic rhinitis.
Montelukast sodium, formulated as tablets (containing 10.4 mg montelukast sodium), chewable tablets (containing 4.2 or 5.2 mg montelukast sodium) or oral granules (in a packet containing 4.2 mg montelukast sodium), is typically given once daily to the patients for the treatment of asthma and seasonal allergic rhinitis. Montelukast sodium is marketed in the United States and other countries by Merck & Co., Inc. under the trade name Singulair®.
Montelukast sodium and related compounds were first disclosed in European Patent No. EP 480,717. The synthesis of montelukast sodium, as taught in patent EP 480,717, involves coupling methyl 1-(mercaptomethyl)cyclopropaneacetate (IIa) with 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-(methanesulfonyloxypropyl) phenyl-2-propanol (III) followed by hydrolysis of the resulting montelukast methyl ester so as to form a free acid, which is followed by conversion of this montelukast free acid to a corresponding sodium salt, isolated as an amorphous material by freeze-drying.
U.S. Pat. No. 5,523,477 describes the formation of montelukast and its subsequent conversion into the dicyclohexyl ammonium salt, which is converted to montelukast sodium.
U.S. Pat. No. 5,614,632 teaches a method of preparing crystalline montelukast sodium, which involves the preparation of the dilithium dianion of 1-(mercaptomethyl)cyclopropaneacetic acid (IV), using butyl lithium, followed by condensation thereof with the mesylate alcohol (III) to yield montelukast acid as a viscous oil. The resulting montelukast acid is converted, via the corresponding dicyclohexyl ammonium salt, to crystalline montelukast sodium.
The extra purification step via the dicyclohexyl ammonium salt, which is disclosed in U.S. Pat. Nos. 5,523,477 and 5,614,632, is necessitated from the difficulties encountered in obtaining crystalline materials. Thus, the crude acid is purified via the dicyclohexylamine salt by reacting it with dicyclohexylamine in ethyl acetate, followed by addition of hexanes to effect crystallization of the dicyclohexylamine salt, or by the crystallization from toluene/heptane. It is mentioned by the inventors of patent U.S. Pat. No. 5,614,632, that the crystalline montelukast dicyclohexylamine salt offers an efficient method for the purification of montelukast, which circumvents the need to use chromatographic purification.
Another process for preparing montelukast sodium is provided in patent application WO 2005/105751 (hereinafter the '751 application). It is stated in the '751 application that butyl lithium is a dangerous and expensive material, hence there is a need for another method which avoids the use of this reagent. Thus, the '751 application provides a process for preparing montelukast sodium comprising reacting 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl(phenyl)-3(hydroxypropyl)phenyl-2-propanol (V) with methanesulfonyl chloride to obtain 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-(methanesulfonyloxypropyl)phenyl-2-propanol (III), which is subsequently reacted with 1-(mercaptomethyl)cyclopropaneacetic acid alkyl ester (e.g., compound IIa or IIb) in a solvent and in the presence of a co-solvent and a base such as NaOH, followed by hydrolysis of the resulting product of the previous step to obtain montelukast sodium.
The synthesis of the 1-(mercaptomethyl)cyclopropaneacetic acid alkyl esters, according to the '751 application, as taught in examples 1 and 2 therein, is depicted in Scheme 1 below.
However, using one of the reagents belonging to the group of compounds 1-(mercaptomethyl)cyclopropaneacetic acid alkyl esters adds an extra synthetic step to the total synthesis of montelukast sodium, because these esters are obtained from the corresponding 1-(mercaptomethyl)cyclopropaneacetic acid.
Thus, there is still a need in the art for a method of preparing montelukast sodium, which has no additional synthetic steps in comparison to the original process described in patent U.S. Pat. No. 5,614,632 on one hand, and avoiding the use of butyl lithium on the other hand.
SUMMARY OF THE INVENTION
In one embodiment, the present invention provides a process for preparing montelukast acid and salts thereof. The process comprises reacting the compound 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl(phenyl)-3(hydroxypropyl)phenyl-2-propanol (V) with methanesulfonyl chloride to provide the mesylate alcohol (III), which is consequently reacted with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) to obtain a montelukast acid or an ammonium salt thereof e.g., the cyclohexyl, cycloheptyl or cyclooctyl ammonium salt. The isolated ammonium addition salt can be purified and converted to montelukast sodium.
Thus, the process for preparing montelukast acid and salts thereof, preferably includes:
reacting 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(hydroxylpropyl)phenyl)-2 propanol (V) with methanesulfonyl chloride to obtain 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(methanesulfonyloxypropyl)-phenyl-2-propanol (III); reacting compound (III) with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) in a solvent mixture containing a base; optionally isolating montelukast acid or adding an organic amine and isolating an addition ammonium salt thereof; and optionally converting the montelukast ammonium salt to montelukast sodium.
Reacting compound (V) with methanesulfonyl chloride preferably includes:
admixing compound (V) with an organic solvent; optionally cooling to reduced temperature and adding a base; adding methanesulfonyl chloride, optionally in several portions, and reacting for sufficient time period to allow completing the reaction; filtering the thus formed suspension and obtaining a filtrate containing the crude product; and optionally using the filtrate in the next reaction.
Reacting compound (III) with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) in a solvent mixture and in the presence of a base preferably includes:
admixing 1-(mercaptomethyl)cyclopropaneacetic acid (IV) with an organic solvent under stirring; admixing a base and optionally a co-solvent to afford a suspension; admixing the solution of compound (III) in an organic solvent, thus a solvent mixture containing the base is formed; stirring for sufficient time period to allow completing the reaction; and optionally isolating montelukat acid as an oil.
In another embodiment, there is provided a process for preparing an ammonium salt of montelukast. The process comprises admixing an amine and the reaction product of compound (IV) and compound (III) to obtain an ammonium salt of montelukast, and optionally purifying the ammonium salt of montelukast. Non-limiting examples of an amine include cyclohexylamine, cyclopentylamine, cycloheptylamine, cyclooctylamine, cyclododecylamine, and phenethylamine.
In another embodiment, there is provided a process for preparing the sodium salt of montelukast from an ammonium salt, the process comprising:
admixing the ammonium salt, an acid, an organic solvent, and water; separating the water; adding a base and water; distilling off at least part of the organic solvent and obtaining an aqueous mixture of the final product; and drying the resulting aqueous mixture to obtain montelukast sodium.
The process disclosed herein enables obtaining Compound (I) in a total yield of about 70%. The purity is at least 98.5%, and can be more than 99%, or greater than 99.5% (as determined by HPLC).
DETAILED DESCRIPTION OF THE INVENTION
The inventors of the present invention have surprisingly discovered that it is not necessary to react 1-(mercaptomethyl)cyclopropaneacetic acid alkyl ester (e.g., compounds IIa or IIb) with the mesylate 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-methanesulfonyloxypropyl)phenyl-2-propanol (III), for preparing montelukast or a salt thereof and 1-(mercaptomethyl)cyclopropaneacetic acid (IV) may be used instead, without the need to use butyl lithium, and thus an extra synthetic step (of preparing the corresponding ester) can be eliminated.
In one embodiment, the present invention provides a process for preparing montelukast acid and salts thereof, which is depicted in Scheme 2 below. The process comprises reacting the compound 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl-(phenyl)-3(hydroxypropyl)phenyl-2-propanol (V) with methanesulfonyl chloride to provide the mesylate alcohol (III), which is consequently reacted with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) to obtain a montelukast acid or an ammonium salt thereof, e.g., the cyclohexyl, cycloheptyl or cyclooctyl ammonium salt. The isolated ammonium addition salt can be purified and converted to montelukast sodium.
Thus, the process for preparing montelukast acid and salts thereof, preferably includes:
reacting 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(hydroxylpropyl)phenyl)-2 propanol (V) with methanesulfonyl chloride to obtain 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenl)-3-(methanesulfonyloxypropyl)phenyl-2-propanol (III); reacting compound (III) with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) in a solvent mixture containing a base; optionally isolating montelukast acid or adding an organic amine and isolating an addition ammonium salt thereof; and optionally converting the montelukast ammonium salt to montelukast sodium.
Reacting compound (V) with methanesulfonyl chloride preferably includes:
admixing compound (V) with an organic solvent; optionally cooling to reduced temperature and adding a base; adding methanesulfonyl chloride, optionally in several portions, and reacting for sufficient time period to allow completing the reaction; filtering the thus formed suspension and obtaining a filtrate containing the crude product; and optionally using the filtrate in the next reaction.
The organic solvent used in the reaction can be toluene, xylenes, tetrahydrofuran (THF), 2-methyltetrahydrofuran, acetonitrile, and mixtures thereof. In some cases the organic solvent comprises THF.
The base used in the reaction is typically an organic amine. Amines contemplated for use in the process include, but are not limited to, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, N,N-diisopropylethylamine (DIEA), N,N-dimethylaniline, or combinations thereof. In a specific embodiment, the base comprises N,N-diisopropylethylamine.
Reacting compound (III) with 1-(mercaptomethyl)cyclopropaneacetic acid (IV) in a solvent mixture and in the presence of a base preferably includes:
admixing 1-(mercaptomethyl)cyclopropaneacetic acid (IV) with an organic solvent under stirring; admixing a base and optionally a co-solvent to afford a suspension; admixing the solution of compound (III) in an organic solvent, thus the solvent mixture containing a base is formed; stirring for sufficient time period to allow completing the reaction; and optionally isolating montelukat acid as an oil.
The organic solvent is typically a polar solvent. Organic solvents contemplated for use in the process include, but are not limited to, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), N-methyl-pyrrolidone (NMP), tetrahydrofuran (THF), 2-methyltetrahydrofuran, acetonitrile, acetone, or mixtures thereof.
The organic solvent can be mixed with a co-solvent, such as water. The amount of the co-solvent is at least 1% by volume, and can be about 3% to about 10%, or about 4% to about 6% by volume, relative to the volume of the organic solvent.
Not bound by theory, it is postulated that a polar solvent, e.g., NMP with optional addition of about 5% water, efficiently dissolves the dianion of compound (IV) (e.g., a disodium dianion) and allows for better reaction between compound (IV) and compound (III).
The base is typically an inorganic base selected from alkaline and alkaline earth hydroxides, C 1 -C 4 alkoxides and hydrides. Specific bases contemplated for use include, but are not limited to, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydride, sodium methoxide, and potassium methoxide. In a specific embodiment the base is sodium hydroxide, e.g., solid NaOH or NaOH solution.
The methansulfonyl chloride can be added to the cooled mixture of base and compound (V). The addition can be drop-wise or at least two portions. The methanesulfonyl chloride can be added in three portions, four portions, five portions, or six portions.
Montelukast acid can be isolated from the reaction of compound (IV) and compound (III) by adding an acid to the mixture. The acid can be either an inorganic acid or an organic acid. Specific organic acids contemplated for use include, but are not limited to, acetic acid, propionic acid, oxalic acid, benzoic acid, maleic acid, malonic acid, fumaric acid, tartaric acid, malic acid, citric acid, and combinations thereof. In a specific embodiment the organic acid comprises tartaric acid.
A process for preparing an ammonium salt of montelukast is disclosed herein. The process comprises admixing an amine and the reaction product of compound (IV) and compound (III) to obtain an ammonium salt of montelukast, and optionally purifying the ammonium salt of montelukast. Non-limiting examples of an amine include cyclohexylamine, cyclopentylamine, cycloheptylamine, cyclooctylamine, cyclododecylamine, and phenethylamine.
An organic solvent can be added to the reaction mixture prior to purifying the ammonium salt of montelukast. The organic solvent can be methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, chloroform, dichloromethane, toluene or mixtures thereof. Preferably, the organic solvent comprises toluene or ethyl acetate.
Purifying can be any means to remove impurities from the ammonium salt of montelukast, including, but not limited to, crystallizing the ammonium salt of montelukast, using chromatography or other separation techniques, extracting the ammonium salt of montelukast from impurities, filtering the ammonium salt of montelukast, or combinations of any two or more of these techniques. When crystallizing is used, the reaction mixture can optionally be seeded with a crystal of the ammonium salt of montelukast.
Crystallizing the ammonium salt of montelukast typically comprises adding an organic solvent to the ammonium salt of montelukast in order to promote crystallization. Typical organic solvents used include, but are not limited to, methanol, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, toluene, and mixtures thereof. In some cases, the organic solvent comprises toluene or toluene having up to 5% methanol.
Further disclosed herein is a process for producing the sodium salt of montelukast from an ammonium salt, the process comprising:
admixing the ammonium salt, an acid, an organic solvent, and water; separating the water; adding a base and water; distilling off at least part of the organic solvent and obtaining an aqueous mixture of the final product; and drying the resulting aqueous mixture to obtain montelukast sodium.
According to one aspect of the present invention, the drying can be via spray-drying. The organic acid used can be any organic acid compatible with the process, but is typically acetic acid, propionic acid, oxalic acid, benzoic acid, maleic acid, malonic acid, fumaric acid, tartaric acid, malic acid, citric acid, or combinations thereof. In a specific embodiment, the organic acid is citric acid. Non-limiting examples of the organic solvent include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, chloroform, dichloromethane, toluene and mixtures thereof. Preferably, the organic solvent comprises dichloromethane.
The process disclosed herein enables obtaining Compound (I) in a total yield of about 70%. The purity is at least 98.5%, and can be more than 99%, or greater than 99.5% (as determined by HPLC).
Reference is now made to the following examples, which together with the above descriptions, illustrate the invention in a non-limiting fashion. Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.
EXAMPLES
Example 1
Preparation of 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(methanesulfonyloxypropyl)phenyl-2-propanol (III)
A 500 ml 3-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 3 g (0.0065 moles) of 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(hydroxylpropyl)phenyl)-2-propanol (V) in 16 ml of anhydrous THF under stirring and cooled to about −15° C. 2.6 ml of N,N-diisopropylethylamine (DIEA) was added in portions followed by addition of 1.0 ml (0.013 moles) of methanesulfonyl chloride in portions, and stirring was maintained at about −15° C. for about 2 hours. A sample was withdrawn and checked by HPLC to ensure that no more than 1% of the starting material was present in the reaction mixture. The cold suspension containing the product 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(methanesulfonyloxypropyl)phenyl-2-propanol (III), was filtered at −15° C. and the cake was washed with cold anhydrous THF. The combined filtrate containing the product was used in the next step (example 2).
Example 2
Preparation of Montelukast Acid Cyclohexyl Ammonium Salt in a Solvent Mixture of DMF and THF Containing NaOH 47%
A 500 ml 3-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 1.8 g (0.0123 moles) of 1-(mercaptomethyl)cyclopropaneacetic acid and 16 ml of DMF under stirring and under nitrogen atmosphere to obtain a solution. 1.8 ml of NaOH 47% (0.032 moles) was added drop-wise and stirring was maintained for 10 minutes to afford a suspension. The solution of compound (III) in 20 ml THF (from example 1) was added in portions at 25° C. After completing the addition, the mixture was stirred for 2 hours at 25° C. and reaction completion was checked by HPLC. 43 ml of ethyl acetate was added to the reaction mixture along with 43 ml of 5% sodium chloride solution. The mixture was stirred at 25° C. for 15 minutes. Then, the layers were separated and 28 ml of 0.5M tartaric acid was added to the upper layer and stirring was maintained at 25° C. for 15 minutes. The layers were separated and the upper layer was washed with 14 ml of water and again separated. The organic layer was distilled to dryness to afford an oily residue.
34 ml of ethyl acetate was added to the residue under stirring to obtain a solution. 0.8 ml of cyclohexylamine was added and stirring was maintained for few minutes at 25° C. and the solution was seeded with crystalline montelukast acid cyclohexyl ammonium salt. Stirring was maintained at 25° C. to afford a suspension, which was filtered off to obtain a cake. The cake was washed with ethyl acetate and dried at 40° C. in vacuum to afford 2.9 g of dry crude montelukast acid cyclohexyl ammonium salt in 65% Yield. The HPLC purity was 99%.
Example 3
Preparation of Montelukast Acid Cyclohexyl Ammonium Salt in a Solvent Mixture of DMF and THF Containing Solid NaOH
A 500 ml 3-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 1.8 g (0.0123 moles) of 1-(mercaptomethyl)cyclopropaneacetic acid and 16 ml of DMF under stirring and under nitrogen atmosphere to obtain a solution. 1.4 g of NaOH pellets (0.035 moles) was added in portions and stirring was maintained for 1 hour to afford a suspension. Then, the solution of compound (III) in 20 ml THF (from example 1) was added in portions at 25° C. After completing the addition, the mixture was stirred for 5 hours at 25° C. and reaction completion was checked by HPLC. 43 ml of ethyl acetate was added to the reaction mixture along with 43 ml of 5% sodium chloride solution. The mixture was stirred at 25° C. for 20 minutes. Then, the layers were separated and 28 ml of 0.5 M tartaric acid was added to the upper layer and stirring was maintained at 25° C. for 15 minutes. The layers were separated and the upper layer was washed with 14 ml of water and again separated. The organic layer was distilled to dryness to afford an oily residue.
34 ml of ethyl acetate was added to the residue under stirring to obtain a solution. 0.8 ml of cyclohexylamine was added and stirring was maintained for few minutes at 25° C. and the solution was seeded with crystalline montelukast acid cyclohexyl ammonium salt. Stirring was maintained at 25° C. to afford a suspension, which was filtered off to obtain a cake. The cake was washed with ethyl acetate and dried at 40° C. in vacuum to afford 3.1 g of dry crude montelukast acid cyclohexyl ammonium salt in 70% Yield. The HPLC purity was 99%.
Example 4
Preparation of Montelukast Acid Cycloheptyl Ammonium Salt in a Solvent Mixture of DMF and THF Containing NaOH 47%
A 500 ml 3-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 1.8 g (0.0123 moles) of 1-(mercaptomethyl)cyclopropaneacetic acid and 16 ml of DMF under stirring and under nitrogen atmosphere to obtain a solution. 2.0 ml of NaOH 47% (0.035 moles) was added drop-wise and stirring was maintained for 10 minutes to afford a suspension. A solution of 3 g of compound (III) in 20 ml THF was added in portions at 25° C. After completing the addition, the mixture was stirred for 2 hours at 25° C. and reaction completion was checked by HPLC. 43 ml of ethyl acetate was added to the reaction mixture and 43 ml of 5%. sodium chloride solution. The mixture was stirred at 25° C. for 15 minutes.
Then, the layers were separated and 28 ml of 0.5 M tartaric acid was added to the upper layer and stirring was maintained at 25° C. for 15 minutes. The layers were separated and the upper layer was washed with 14 ml of water and again separated. The organic layer was distilled to dryness to afford an oily residue.
34 ml of ethyl acetate was added to the residue under stirring to obtain a solution. 0.89 ml of cycloheptylamine was added and stirring was maintained for few minutes at 25° C. and the solution was seeded with crystalline montelukast acid cycloheptyl ammonium salt. Stirring was maintained at 25° C. to afford a suspension, which was filtered to obtain a cake. The cake was washed with ethyl acetate and dried at 40° C. in vacuum to afford 2.7 g of dry crude montelukast acid cycloheptyl ammonium salt in 65% yield, having a purity of 98% (according to HPLC).
Example 5
Preparation of Montelukast Sodium
A three-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 9.06 g (0.0198 moles) of 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(hydroxylpropyl)phenyl)-2-propanol (V) in 48 ml of anhydrous THF under stirring and cooled to about −20° C. 4.8 ml (0.028 moles) of N,N-diisopropylethylamine (DIEA) was added in portions followed by addition of 1.86 ml (0.024 moles) of methanesulfonyl chloride in portions, and stirring was maintained at about −20° C. for about 2 hours. The cold suspension containing the product 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)ethenyl)phenyl)-3-(methanesulfonyloxypropyl)phenyl-2-propanol (III), was filtered off at −20° C. and the cake was washed with cold anhydrous THF. The combined solutions of compound (III) in THF was kept aside at 5° C.
Another three-necked flask equipped with a thermometer, a nitrogen inlet and a magnetic stirrer was charged at room temperature with 6.7 g (0.0459 moles) of 1-(mercaptomethyl)cyclopropaneacetic acid and 48 ml of NMP under stirring and under nitrogen atmosphere to obtain a solution. 4.5 g of NaOH flakes (0.1125 moles) was added in one portion at room temperature followed by addition of 2.4 ml of water, and stirring was maintained for 1 hour to afford a suspension. The solution of compound (III) in about 50 ml THF, which was kept at 5° C., was added in portions at ambient temperature. After completing the addition, the mixture was stirred for 2 hours and reaction completion was checked by HPLC. 130 ml of toluene was added to the reaction mixture along with 130 ml of 5% sodium chloride solution, and the mixture was stirred for 20 minutes. Then, the layers were separated and the upper organic layer was washed with 130 ml of 5% sodium chloride solution, and the layers were separated. 84 ml of 0.5 M tartaric acid solution was added to the upper layer and the layers were separated. The upper layer was washed with 40 ml of water and again separated. The organic layer was distilled to dryness to afford an oily residue. 90 ml of toluene was added to the residue under stirring to obtain a solution. 3.1 ml of cyclooctylamine (0.0226 moles) was added and stirring was maintained for few minutes and the solution was seeded with crystalline montelukast acid cyclooctyl ammonium salt. Stirring was maintained at room temperature to afford a suspension, which was filtered off to obtain a cake. The cake was washed with toluene and dried at 40° C. in vacuum to afford 9.88 g of dry crude montelukast acid cyclooctyl ammonium salt in 70% yield, having 98% purity (according to HPLC). The crude montelukast cyclooctyl ammonium salt was crystallized from toluene containing about 2% of methanol to obtain a product having 99% purity (according to HPLC). 30 ml of dichloromethane was added followed by addition of 17 ml of 0.5M citric acid solution. The mixture was stirred at room temperature for half an hour to afford a two phase system. The layers were separated and the organic layer (containing the montelukast acid) was washed with 3×15 ml water, the layers were separated and the aqueous layer was removed. 20 ml of water was added under stirring followed by addition of 4 ml of 1M NaOH solution and stirring was maintained for about 5 minutes. The dichloromethane was distilled off at a temperature lower than 35° C. The pH was checked and 1 M NaOH solution was added drop-wise until the pH value was about 10.5. The aqueous layer (containing the desired end product) was freeze-dried to obtain 8.3 g of montelukast sodium in 99% yield having a purity of 99.8% (according to HPLC). | The present invention provides a process for preparing highly pure montelukast and salts thereof by reacting the side-chain precursor 1-(mercaptomethyl)-cyclopropaneacetic acid with 2-(2-(3S)-(3-(7-chloro-2-quinolinyl)-ethenyl)phenyl)-3-(methanesulfonyloxypropyl)phenyl-2-propanol in a solvent mixture containing a base. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a winding and re-winding apparatus driven by a D.C. motor with an electronic commutation device. Specifically the invention pertains to control of a D.C. motor based on the polarity and absolute magnitude of a signal proportional to the deflection of a position sensing member.
2. Description of the Prior Art
Winding and re-winding devices are generally known. In such winding and re-winding apparatus a D.C. motor driving a winding or unwinding spool is controlled for the purpose of keeping constant the tension of the material being wound or unwound. Such a control must not only accelerate but also decelerate the spool if required. Therefore, the D.C. motor must be appropriately controlled by a position control. In the prior art, D.C. commutation machines have been used to drive the spool in the winding or re-winding apparatus. Control of the acceleration as well as the deceleration of the motors is possible only through the use of a closed-loop control system. This control system is switched appropriately as a function of the polarity of the position control output signal.
Due to the fact that commutation motors need constant servicing, it is advantageous to employ in their place maintenance-free brushless D.C. motors. However, a brushless D.C. motor cannot be reversed by simply reversing the polarity of the input voltage which makes impossible the simple replacement of a commutation motor by a brushless D.C. motor.
It is an object of this invention to create a winding and re-winding apparatus which is equipped with a brushless D.C. motor the speed of which can be accelerated as well as decelerated by a control loop driven by a position sensor.
SUMMARY OF THE INVENTION
According to the invention, the solution of the problem posed is found in a winding and re-winding apparatus of the above-described type by providing a D.C. motor with an electronic commutation device switched in accordance with the polarity of the position control output signal. This position control output signal is generated by a first amplifier signal which is proportional to the polarity of the position sensing output signal and by means of a second amplifier unit forming the absolute value of the position sensing output signal. These signals are then applied to the electronic commutation device which controls the speed of the brushless D.C. motor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a winding and re-winding apparatus.
FIG. 2 is an electronic schematic diagram of a position control circuit and of the first and second amplifier units succeeding it.
DESCRIPTION OF THE INVENTION
FIG. 1 shows a brushless D.C. motor 1 driving a spool 2 from which material 3 is wound or unwound. The material 3 being wound or unwound is led past a pendulum roller 5 by guide rollers 4. The pendulum roller 5 is pivoted about a shaft 6. A permanent magnet 7 with two-pole magnetization is mounted on the shaft 6. This permanent magnet is deflected in accordance with the deflection of the pendulum roller 5. The position of the permanent magnet 7 is sensed by a Hall-effect generator 8. The output signal supplied by the Hall-effect generator 8 is proportional to the position or deflection of the pendulum roller 5. The output signal of the Hall-effect generator 8 is fed to a position control circuit 10 by means of an amplifier 9. Connected to the output of the position control circuit 10 is a first amplifier unit 11 which determines the polarity of the position control output signal. The absolute value of the position control output signal is generated in a second amplifier unit 12. The output signal of the second amplifier unit is compared with the actual value of a signal proportional to the speed of the motor and the different signal is applied to a control amplifier stage 13. The output signal of the control amplifier stage 13 is applied to an electronic commutation device 14 well known in the prior art. The polarity of the commutation device 14 is controlled as a function of the first amplifier unit 11.
Shown in FIG. 2 is a schematic diagram of the position control circuit 10, the first amplifier unit 11, and the second amplifier unit 12. Signals generated by amplifier 9 are applied to the inverting input terminal(-) of operational amplifier 20 by means of a first RC circuit consisting of a capacitor 21, a series resistor 22 and a shunt resistor 19. Negative feedback from the output of operational amplifier 20 to the inverting input is provided by means of a second RC circuit consisting of a capacitor 23 and a series resistor 24. The non-inverting input of operational amplifier 20 is connected to the reference potential 0.
The output of the operational amplifier 20 which forms the output of the position control circuit 10 is connected to the inverting input of a first operational amplifier 26 by means of a first input resistor 25 and to the inverting input of a second operational amplifier 28 of the second amplifier unit 12 by means of a second input resistor 27. The output of the first operational amplifier 26 is fed back to the inverting input of operational amplifier 26 by means of a two-way rectifier circuit consisting of two diodes 29 and 30 and two resistors 31 and 32. The reference potential 0 is applied to the non-inverting input of the operational amplifiers 26 and 28. The inverting input of the second operational amplifier 28 is additionally connected at a point between the diode 29 and the resistor 31 of the two-way rectifier circuit by means of an input resistor 33. The output of the second operational amplifier 28 is fed back negatively to the inverting input by means of a feedback resistor 34. The two operational amplifiers 26 and 28 together with their circuit components form the second amplifier unit 12. With a positive input at resistors 25 and 27, amplifier 26 inverts and has a negative output. The negative output is fed back through the diode 30 and resistor 32. The diode 29 blocks. Amplifier 28, at its inverting input has an input through the resistor 27. This positive voltage at that input will be inverted by the amplifier 28 to provide a negative output. If the input voltage is negative this negative voltage is inverted through the amplifier 26 and a positive voltage appears at its output and through the diode 29. Now, amplifier 28 will have a negative input through resistor 27 and a positive input through resistor 33. If the gain of amplifier 26 is made equal to two its output will be twice its input. When this is added to the negative voltage throught the resistor 27, the net result is a positive voltage which, again, results in a negative output. Circuits of this nature are well known by those skilled in the art and are discussed, for example, in "Applications Manual for Operational Amplifiers for Modeling, Measuring, Manipulating and Much Else," published by Philbrick Nexus Research 1968. In particular, see paragraph II.42.
The circuit shown labelled as 11 generates a signal proportional to the polarity of the signal from amplifier 9. This function can be performed by a limit switch i.e. a comparator or by a bistable flip-flop, but the preferred embodiment of unit 11 consists of an operational amplifier 35 to the inverting input of which the reference potential 0 is applied. The non-inverting input is connected with the output of the position control circuit 10 or operational amplifier 20 by means of a fourth input resistor 36. The output of this operational amplifier 35 is connected to the non-inverting input by means of a feedback resistor 37. This results in a positive feedback as is well known by those skilled in the art. By so coupling an operational amplifier it acts as a comparator. The inverting input is referenced to zero volts. If a positive input is applied to the non-inverting input a positive output results. As this is fed back it causes the amplifier to go more positive until saturation is reached. Thus, the amplifier will go to its maximum output voltage. Similarly for a negative input voltage, a negative output will result. Once again the positive feedback will cause the amplifier to go into saturation. Thus, any deviation from zero will result in an output from amplifier 35 of one or the other polarity depending on its input.
The device functions as follows. If through whatever influence the winding or unwinding speed of the material 3 being wound or unwound is altered, the pendulum roller 5 is deflected about the shaft 6. In accordance with this deflection the Hall-effect generator 8 transmits to the amlifier 9 a signal which is applied to the position control circuit 10. The signal received is amplified by the position control signal having a transfer function defined by the ratio of the feedback and feedforward impedances. The output of the positive control circuit 10 is applied to the first and the second amplifier units 11 and 12. The first amplifier unit 11 determines the polarity of the position control output signal and switches the commutation device 14 accordingly. In consequence of the switching of the commutation device 14, the individual phases of the stator windings of the brushless D.C. motor 1 will be energized in different sequence, thereby accomplishing a reversal of the stator field direction.
In the second amplifier unit 12 the absolute value of the position control output signal is formed. This absolute value is compared with a signal proportional to the motor's speed and fed to the control amplifier 13. Control amplifier 13 provides a magnitude signal to the commutation device 14 which applies the signal to the stator winding of the brushless D.C. motor 1.
Due to the switching of the commutation device 14 as a function of the polarity of the putput signal of the position control unit 10, the brushless D.C. motor is accelerated or decelerated. In addition the control amplifier 13 can function independently of the polarity of the output signal loop of the formation of the absolute value of the output signal of the position control circuit 10. Thus there has been shown novel apparatus for the control of a brushless D.C. motor in either a decelerating or accelerating mode. | This invention pertains to a D.C. motor with an electronic commutation device provided as the reversible D.C. motor used in winding and re-winding apparatus. The electronic commutation device polarity is determined in accordance with the polarity of a position control output signal. Furthermore, the absolute value of the position control output signal is formed and applied to regulate the speed of the D.C. motor. | 1 |
This is a division of application Ser. No. 07/379,656 filed July 11, 1989 (issued as U.S. Pat. No. 4,918,054 on Apr. 17, 1990) which is a continuation of application Ser. No. 06/813,617 filed Dec. 26, 1985 (abandoned).
BACKGROUND TO THE INVENTION
The present invention relates to new antibiotics, which we have called "chloropolysporins B and C", to a process for their preparation by the cultivation of a microorganism and to their use, both therapeutic, in the treatment and prophylaxis of infections caused by bacteria, and as a growth-promoting agent for animals.
As resistance to conventional antibiotics becomes increasingly established in common strains of pathogenic bacteria, the need for a wider variety of antibiotics for use in the fight against such bacteria becomes ever more crucial. Moreover, various antibiotics, for example chloramphenicol, aureomycin, vancomycin and avoparcin, have been administered, or have been proposed for administration to poultry and other farm animals, including the ruminants and pigs, for the prophylaxis of disease or to promote growth or milk production. However, an inherent disadvantage of the use of antibiotics in this way is that there is some risk that traces of the antibiotics or of metabolic products thereof may be found in animal products intended for human consumption (such as eggs, milk or meat); the alleged dangers of such residues are increasingly criticized by some sections of the community There is, accordingly, a considerable desire amongst farmers for an antibiotic substance which will have the desired growth-promoting effect but which will leave no or no significant residues in animal products.
In U.S. patent application Ser. No. 627,439, filed July 3, 1984 which issued as U.S. Pat. No. 4,557,933, on Dec. 10, 1985 assigned to the present assignees, there is disclosed an antibiotic, there referred to as "chloropolysporin", which was isolated from the culture medium of a microorganism identified as Micropolyspora sp. SANK 60983.
We have now discovered that the same microorganism, and hence others of the genus Micropolyspora, produces a further two new antibiotic substances that are highly effective against gram-positive bacteria and that show considerable promise for use as growth-promoting agents in animals. It is believed that these substances may have been present in the chloropolysporin of the prior Application.
BRIEF SUMMARY OF INVENTION
The new antibiotic substances of the invention are called "chloropolysporin B" and "chloropolysporin C" and, since their structures have not been completely elucidated, they may be characterized by their properties.
Chloropolysporin B, as its sulfate, is characterized by the properties:
(a) it takes the form of an amphoteric white powder, soluble in water;
(b) specific rotation: [α] 25 -64.5° (C=1.04, 0.1 N aqueous hydrochloric acid, sodium D-line);
(c) elemental analysis:
C, 48.33%: H, 5.05%; N, 5.48%; C1, 5.11%; S, 1.00%;
(d) on acid hydrolysis it yields:
neutral saccharides: glucose, mannose and rhamnose; amino acids: 3-chloro-4-hydroxyphenylglycine and N-methyl-p-hydroxyphenylglycine
(e) ultraviolet absorption spectrum:
as illustrated in FIG. 1 of the accompanying drawings, having an absorption maximum λ max at 280 nm (E 1cm =51) in a 0 1 N solution of hydrochloric acid, the absorbence, E, being measured at a concentration of 1% w/v;
(f) infrared absorption spectrum:
the infrared absorption spectrum (υ cm -1 ) measured on a KBr disc is as shown in FIG. 2 of the accompanying drawings;
(g) nuclear magnetic resonance spectrum:
the nuclear magnetic resonance spectrum (δ ppm). measured at 270 MHz in deuterated dimethyl sulfoxide using tetramethylsilane as the internal standard, is as illustrated in FIG. 3 of the accompanying drawings;
(h) solubility:
soluble in water and methanol, sparingly soluble in acetone, and insoluble in ethyl acetate, chloroform and benzene;
(i) color reactions:
positive in Ninhydrin and Rydon-Smith reactions;
(j) thin layer chromatography:
Rf value=0.65 using a cellulose sheet (Eastman) as adsorbent and a 15:10:3:12 by volume mixture of butanol, pyridine, acetic acid and water as the developing solvent;
(k) high voltage paper electrophoresis: using Toyo's filter paper No. 51A in a 0.1 M tris-hydrochloric acid buffer solution of pH 7.5 (3300 volt/60 cm, 1 hour); the migration distance (detected by bioautography with Bacillus subtilis PCI 219) from the origin to the cathode was 4 cm;
(1) molecular formula: C 83 H 89 O 34 N 8 Cl 3 ·0.5H 2 SO 4 ·10H 2 O
(m) molecular weight:
the molecular weight, measured by FAB-MS, was 1846 (MH + , 1847)
"FAB-MS" is Fast Atom Bombardment Mass Spectroscopy.
Chloropolysporin C, as its sulfate, may be characterized by the following properties:
(a) it takes the form of an amphoteric white powder, soluble in water;
(b) specific rotation: [α] 25 -64.4° (C=1.08, 0.1 N aqueous hydrochloric acid, sodium D-line);
(c) elemental analysis:
C, 50.53%; H, 4.69%; N, 6.14%; Cl, 5.62%; S, 1.12%;
(d) on acid hydrolysis it yields:
neutral saccharides: glucose and mannose; amino acids: 3-chloro-4-hydroxyphenylglycine and N-methyl-p-hydroxyphenylglycine;
(e) ultraviolet absorption spectrum:
as illustrated in FIG. 4 of the accompanying drawings, having an absorption maximum λ max at 280 nm (E 1cm =57) in a 0.1 N solution of hydrochloric acid, the absorbence, E, being measured at a concentration of 1% w/v;
(f) infrared absorption spectrum:
the infrared absorption spectrum (λ cm -1 ) measured on a KBr disc is as shown in FIG. 5 of the accompanying drawings;
(g) nuclear magnetic resonance spectrum:
the nuclear magnetic resonance spectrum (δ ppm), measured at 400 MHz in deuterated dimethyl sulfoxide using tetramethylsilane as the internal standard, is as illustrated in FIG. 6 of the accompanying drawings;
(h) solubility:
soluble in water and methanol, sparingly soluble in acetone, and insoluble in ethyl acetate, chloroform and benzene;
(i) color reactions:
positive in Ninhydrin and Rydon-Smith reactions;
(j) thin layer chromatography:
Rf value=0.65, using a cellulose sheet (Eastman) as adsorbent and a 15:10:3:12 by volume mixture of butanol, pyridine, acetic acid and water as the developing solvent;
(k) molecular formula:
C 77 H 79 O 30 N 8 Cl 3 . 0.5H 2 SO 4 . 5H 2 O;
(1) molecular weight the molecular weight, measured by FAB-MS, was 1700 (MH + , 1701).
The present invention provides these compounds for the first time in a form suitable for medicinal or veterinary use, free from native impurities.
The invention also provides pharmaceutically acceptable salts of these compounds.
The invention also provides a process for producing chloropolysporin B or chloropolysporin C and salts thereof by cultivating a chloropolysporin B- or C-producing microorganism of the genus Micropolyspora in a culture medium therefor and isolating chloropolysporin B or C or a salt thereof from the cultured broth.
The invention still further provides a pharmaceutical or veterinary composition comprising such chloropolysporin B or C or a salt thereof in admixture with a pharmaceutical or veterinary carrier or diluent.
The invention still further provides a method for the treatment or prophylaxis of bacterial infections by administering such chloropolysporin B or C or a salt thereof to an animal which may be human or non-human.
The invention still further provides a method of promoting the growth of a farm animal by the oral administration of such chloropolysporin B or C or a salt thereof to said animal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the ultraviolet absorption spectrum of chloropolysporin B is the invention;
FIG. 2 is the infrared absorption spectrum of chloropolysporin B of the invention;
FIG. 3 is the NMR spectrum of chloropolysporin B of the invention;
FIG. 4 is the ultraviolet absorption spectrum of chloropolysporin C;
FIG. 5 is the infrared absorption spectrum of chloropolysporin C; and
FIG. 6 is the NMR spectrum of chloropolysporin C.
DETAILED DESCRIPTION OF INVENTION
The invention is based upon the discovery and isolation of chloropolysporin B and chloropolysporin C and salts thereof, each free from contamination by other products of cell metabolism, and preferably free from each other.
Chloropolysporins B and C are produced by the cultivation of a Micropolyspora strain herein identified as Micropolyspora sp. SANK 60983 , which was isolated from a soil sample collected in Tochigi Prefecture, Japan.
The microorganism, Micropolyspora sp. SANK 60983 has the characteristics described hereafter and is as described in U.S. patent application No. 627,439, referred to above. These characteristics were determined by cultivation on various media prescribed by the ISP (International Streptomyces Project) or with the media recommended by S. A. Waksman in Volume 2 of "The Actinomycetes", in all cases at a temperature of 28° C.
1. Morphological Characteristics
Strain SANK 60983 grows relatively well on various media. The aerial mycelium is hardly visible on almost all media but may occasionally be visible on glycerol-asparagine agar or on potato extract-carrot extract agar. The aerial and vegetative mycelia bear, at the top and the middle, short chains of spores, normally from 1 to 20, although occasionally more than 20, spores. No distinct fragmentation of the hyphae is observed with the strain although it may be observed during later stages of the culture.
2. Culture Characteristics
Strain SANK 60983 can produce pale yellow, yellowish brown or yelloWish gray colors. Aerial hyphae are not observed on most media, although white aerial hyphae are produced on some media. No soluble pigment is produced. Table 1 shows the results obtained after cultivation for 14 days at 28° C. on various standard culture media. The color names and numbers used were assigned according to the "Guide to Color Standard", a manual published by Nippon Shikisai Kenkyusho, Tokyo, Japan.
TABLE 1______________________________________ Aerial SolubleMedium Growth Mycelium Reverse Pigment______________________________________Yeast Abundant, None Yellowish- Noneextract- raised, brownmalt wrinkled, (8-8-8)extract yellowish-agar brown(ISP 2) (8-8-8)Oatmeal Good, None Dull Noneagar smooth, yellow(ISP 3) dull (8-8-9) yellow (8-8-9)Inorganic Abundant, None Yellowish- Nonesalt- smooth, graystarch yellowish- (2-9-10)agar gray to pale(ISP 4) (2-9-10) yellowish- to pale brown yellowish- (6-8-9) brown (6-8-9)Glycerol- Good, Poor, Yellowish- Noneasparagine wrinkled, white brownagar yellowish- (2-9-10)(ISP 5) brown (2-9-10)Peptone- Moderate, None Pale Noneyeast smooth, yellowish-extract- pale browniron agar yellowish- (4-8-9)(IPS 6) brown (2-8-9)Tyrosine Abundant, None Dull Noneagar raised, yellow(ISP 7) wrinkled, (10-8-8) pale yellowish- brown (14-8-9)Sucrose Abundant, None Pale Nonenitrate raised, yellowish-agar wrinkeld, brown pale (4-8-8) yellow (12-8-10)Glucose- Moderate None Yellowish- Noneasparagine smooth, grayagar yellowish- (2-9-10) gray (2-9-10)Nutrient Moderate None Pale Noneagar smooth, yellowish-(Difco) pale brown yellowish- (6-8-9) brown (6-8-9)Water Poor, None Yellowish- Noneagar smooth, gray yellowish- (1-9-10) gray (1-9-10)Potato Moderate Poor, Yellowish- Noneextract- smooth, white graycarrot yellowish- (2-9-10)extract grayagar (2-9-10)______________________________________
3. Physiological Properties.
The physiological properties of strain SANK 60983 are shown in Table 2.
TABLE 2______________________________________Decomposition: Adenine - Casein + Xanthine - Hypoxanthine + Urea +Hydrolysis of starch ±Liquefaction of gelatin +Coagulation of milk -Peptonization of milk -Reduction of nitrate +Secretion of +deoxyribonucleaseMelanin formation ISP 1 - ISP 6 - ISP 7 -Acid production from: Sodium Acetate - Sodium Succinate - Sodium Citrate - Sodium Pyruvate - Sodium Tartarate - --D-Glucose + .sub.-- L-Arabinose + --D-Xylose + Inositol + --D-Mannitol + --D-Fructose + .sub.-- L-Rhamnose + Sucrose + Raffinose ±Utilization of --D-Glucose +carbon sources: .sub.-- L-Arabinose + --D-Xylose + Inositol + --D-Mannitol + --D-Fructose + .sub.-- L-Rhamnose + Sucrose + Raffinose ±Growth in NaCl: 3% w/v + 5% w/v ± 7% w/v ± 10% w/v -Range of growth 10° C. -temperature: 20° C. + 28° C. + 37° C. + 45° C. -______________________________________
In the above Table, "+" means positive, "-" means negative and "+" means slightly positive.
Although coagulation and peptonization of milk are both reported as negative, they may occasionally turn positive after long-term culture.
4. Whole Cell Components
Acid hydrolyzates of bacterial cells were assayed by paper chromatography, using the method of M. P. Lechevalier et al. ["The Actinomycetes Taxonomy", page 225 (1980)]. meso-Diaminopimelic acid, arabinose and galactose were found to be present in the cell walls, which are thus of Type IV, whilst the whole cell sugar pattern is of Type A. The characteristic acyl group of the cell wall was also investigated by the method of Uchida et al. [J. Gen. Appl. Microbiol, 23,249 (1977)] and found to be the acetyl group.
None of the known genera of actinomycetes has been reported to be capable of forming spores in the middle of the hyphae. However, from a comparison of other characteristics, the new strain is clearly related to the genera Actinopolyspora, Saccharopolyspora, Pseudonocardia and Micropolyspora. However, both Actinopolyspora and Saccharopolyspora allow spores to grow only on the tips of aerial hyphae, and the former is a highly halophilic genus, whilst the characteristic acyl group of the cell wall of the latter is the glycolyl group. For these reasons, the new strain SANK 60983 cannot be assigned to either of these genera. Although strains of the genus Pseudonocardia can grow spores on the aerial hyphae and on the vegetative mycelium, as does strain SANK 60983, the site of its growth takes place only at the tip of the hyphae and, moreover, its hYphae characteristically grow by budding; thus, strain SANK 60983 cannot be assigned to the genus Pseudonocardia.
The only difference between the genus Micropolyspora and strain SANK 60983 is that the site of growth of spores of Micropolyspora is limited to the tips of the hyphae, whereas that of SANK 60983 is at both the tip and the middle of the hyphae.
At the present time, when there has been virtually no discussion in learned circles as to the implications for taxonomy of differences of this type, it would seem inappropriate to differentiate between genera solely on the basis of differences in the site of growth of their spores. Accordingly, it seems most satisfactory to regard the strain SANK 60983 as representative of a new species of the genus Micropolyspora and it has, accordingly, been named Micropolyspora sp. SANK 60983. It should, however, be remembered that assignment of a strain of microorganism to any particular species, genus or even family is largely a matter of consensus amongst those experienced in the study of the particular class of microorganism involved and the original assignment of a microorganism can be, and not infrequently is, changed after wider discussion.
The strain SANK 60983 has been deposited with the Fermentation Research Institute, Agency of Industrial Science and Technology. Ministry of International Trade and Industry, Japan, on Mar. 10, 1983 under the accession No. FERM P-6985 and was re-deposited in accordance with the conditions stipulated by the Budapest Treaty with said Fermentation Research Institute on June 8, 1984 under the accession No. FERM BP-538.
It has been established that strain SANK 60983 produces chloropolysporins B and C. However, as is well known, the properties of microorganisms falling within the general category of the actinomycetes can vary considerably and such microorganisms can readily undergo mutation, both through natural causes and as the result of induction by artificial means. Accordingly, the process of the present invention embraces the use of any microorganism which can be classified within the genus Micropolyspora and which shares with the strain SANK 60983 the characteristic ability to produce chloropolysporins B and C.
The cultivation of microorganisms of the genus Micropolyspora in accordance with the present invention to produce chloropolysporins B and C can be performed under conditions conventionally employed for the cultivation of actinomycete species, preferably in a liquid culture, and desirably with shaking or stirring and aeration. The nutrient medium used for the cultivation is completely conventional and contains such constituents as are commonly used in the cultivation of the actinomycetes. Specifically, the medium should contain an assimilable carbon source, suitable examples of which include glucose, maltose, sucrose, mannitol, molasses, glycerol, dextrin, starch, soybean oil and cottonseed oil; an assimilable nitrogen source, suitable examples of which include soybean meal, peanut meal, cottonseed meal, fish meal, corn steep liquor peptone, meat extract, pressed yeast, yeast extract, sodium nitrate, ammonium nitrate or ammonium sulfate; and one or more inorganic salts, such as sodium chloride, phosphates, calcium carbonate and trace metal salts. Where cultivation is effected in a liquid medium, it is generally desirable to incorporate an anti-foaming agent (for example silicone oil, vegetable oil or a suitable surfactant) in the medium.
The cultivation is suitably performed at a substantially neutral pH value and at a temperature of from 24° to 30° C., more preferably at about 28° C.
The production of chloropolysporins B and C as cultivation proceeds may be monitored by a variety of conventional microbiological assay techniques for monitoring the production of antibiotics (when they are produced by microbial culture) and which require little or no elaboration here. A suitable technique might be the paper disc-agar diffusion assay (using, for example, a paper disc of diameter about 8 mm produced by Toyo Kagaku Sangyo Co. Ltd) and using, for example, Bacillus subtilis PCI 219 or Staphylococcus aureus FDA 209P JC-1 as the test organism.
The amount of chloropolysporins B and C produced normally reaches a maximum after cultivation has proceeded for 55-70 hours and it is clearly desirable to separate the chloropolysporins from the culture medium no later than the time when this maximum has been reached. However, this period may vary depending upon the cultivation conditions and techniques, and a shorter or longer period may be appropriate, depending upon the circumstances. The correct cultivation time may readily be assessed for every case by routine experiment, using suitable monitoring techniques, e.g. as described above.
Chloropolysporins B and C are mainly released into the liquid portion of the cultured broth and can thus be recovered by removing solid matter, including the mycelium, for example by filtration (preferably using a filter aid such as diatomaceous earth) or by centrifugation. It can then be recovered from the separated liquid portion by conventional techniques and, if desired, then purified.
Chloropolysporins B and C are preferably separated from other products in said liquid portion by means of an adsorbent, either by adsorbing the impurities or by absorbing the chloropolysporins or by adsorbing both separately or together and then eluting the chloropolysporins. A wide range of adsorbents may be used; examples which we have found to be particularly satisfactory include: activated carbon; and adsorbing resins such as AMBERLITE (registered trade mark) XAD-2, XAD-4 or XAD-7 (products of Rohm and Haas), DIAION (registered trade mark) HP 10, HP 20 CHP 20P or HP 50 (products of Mitsubishi Chemical Industries Co., Ltd.) and polyamide gels (a product of Woelm Pharma, West Germany). The impurities present in the liquid portion may be removed by passing the solution containing the chloropolysporins through a layer or column of one or more of the aforementioned adsorbents or by adsorbing the chloropolysporins on one or more of the adsorbents and then eluting the chloropolysporins, either separately or together, with a suitable eluent. Suitable eluents include mixtures of methanol, acetone or butanol with water.
The chloropolysporins B and C thus obtained may be further purified by various means. Suitable methods include: partition column chromatography using a cellulose product, such as AVICEL (a registered trade mark for a product of Asahi Chemical Industry Co., Ltd.) or SEPHADEX LH-20 (a registered trade mark for a product of Farmacia Sweden); reverse phase column chromatography using a carrier for the reverse phase; extraction based on the differences in distribution in solvents between chloropolysporins B and C and their contaminating impurities; or the counter-current distribution method. These purification techniques may be used singly or in combination and may, if needed, be repeated one or more times.
Chloropolysporins B and C are preferably separated from each other by chromatography. A preferred system for this purpose is System 500 (a product of Waters Co.), using the Preppack C 18 cartridge. A suitable eluent is a buffered mixture containing acetonitrile and maintained at a slightly acidic pH value.
Depending upon the culture conditions chloropolysporins B and C can exist in the mycelium from the culture broth and can be extracted therefrom by conventional techniques. For example, they can be extracted with a hydrophilic organic solvent (such as an alcohol or acetone), and then the solvent removed from the extract to leave a residue, which is dissolved in an aqueous medium. The chloropolysporins can be extracted from the resulting solution and purified as described above.
Chloropolysporins B and C thus obtained have, as their sulfates the physical and chemical properties described above. They are normally and preferably separated from the culture broth in the form of a water-soluble salt and are most conveniently characterized in the form of such a salt, i.e., as herein, in the form of the sulfate, since chloropolysporins B and C themselves (i.e. the free bases) are insoluble in water.
Since chloropolysporins B and C are amphoteric in character, they form salts and these salts also form part of the present invention. The nature of such salts is not critical, except that, where they are to be used for medicinal or veterinary purposes, they must be medicinally acceptable, i.e. they must not, or must not to a significant extent, either have increased toxicity or have reduced activity, as compared with the free base. Examples of suitable acids for the formation of such salts include: inorganic acids, such as hydrochloric acid, sulfuric acid or phosphoric acid: organic carboxylic acids, such as acetic acid, citric acid, tartaric acid, malonic acid, maleic acid, malic acid, fumaric acid, itaconic acid, citraconic acid or succinic acid; and organic sulfonic acids, such as methanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid or p-toluenesulfonic acid.
Where the chloropolysporin B or C is isolated in the form of a salt, it may be converted to the free base by conventional means, such as the use of ion-exchange resins or of adsorbents for reverse phase chromatography. An aqueous solution of a salt will normally have an acidic pH value; adjustment of this pH value to approximate neutrality will result in mainly precipitation of the free base, which may then be collected by suitable means, e.g. filtration or centrifugation. This product will, howeVer, normally be contaminated by impurities, including minor proportions of the relevant salts, and will, therefore, normally require further purification. Accordingly a more preferred method is by using, for example, a suitable ion-exchange resin or an adsorbent for reverse phase chromatography. These compounds, however, share with known glycopeptide antibiotics such as avoparcin, the property of being very difficult to isolate in the form of the free base [see e.g. W. J. McGahren et al., Journal of Antibiotics, XXXVI, 12. 1671 (1983)]and they are, accordingly, preferably isolated and employed in salt form.
It is currently believed that chloropolysporins B and C may be represented by the planar structural formula: ##STR1## in which: for chloropolysporin B,
R 1 represents a ristosamine residue;
R 2 represents a mannose residue;
R 3 represents a glucose residue; and
R 4 represents a rhamnose residue;
for chloropolysporin C,
R 1 represents a ristosamine residue;
R 2 represents a mannose residue;
R 3 represents a glucose residue; and
R 4 represents a hydrogen atom.
Accordingly, chloropolysporins B and C differ only in the substituent represented by --OR 4 in the above formula.
It is probable that the various assymetric carbon atoms shown in the above formula adopt, in chloropolysporins B and C, specific configurations, but these have not, to date, been elucidated.
The minimal inhibitory concentrations (MIC) of chloropolysporins B and C against various gram-positive and gram-negative bacteria were determined by the two-fold agar dilution method, using a Mueller-Hinton agar medium (produced by Difco); the MIC against anaerobic bacteria was determined using a GAM agar medium (produced by Nissui). The results are shown in Tables 3 and 4.
TABLE 3______________________________________ MIC (μg/ml) ChloropolysporinTest strain B C______________________________________Staphylococcus aureus FDA 209P JC-1 1.56 1.56Staphylococcus aureus SANK 70175 3.13 1.56Staphylococcus aureus Smith 12.5 6.25Staphylococcus SANK 71575 3.13 3.13epidermidisEnterococcus faecalis SANK 71778 1.56 1.56Bacillus subtilis PCI 219 0.78 0.78Mycobacterium smegmatis ATCC 607 25.0 12.5Escherichia coli NIHJ JC-2 >100 >100Klebsiella pneumoniae PCI 602 >100 >100Pseudomonas aeruginosa NCTC 10490 >100 >100Serratia marcescens SANK 73060 >100 >100Proteus mirabilis SANK 70461 >100 >100______________________________________
TABLE 4______________________________________ MIC (μg/ml) ChloropolysporinTest strain B C______________________________________Bacteroides fragilis >100 >100Eubacterium cylindroides 6.25 3.13Fusobacterium necrophorum >100 >100Peptostreptococcus saccharoliticus 6.25 3.13Peptostreptococcus parvulus 0.78 0.39Propionibacterium acnes 0.78 0.39Clostridium symbiosum 1.56 0.39Clostridium ramosum 1.56 1.56Clostridium perfringens 0.20 0.10Clostridium difficile 0.78 0.39______________________________________
From the results given in the above Tables, it can be seen that chloropolysporins B and C are effective against aerobic gram-positive bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Bacillus subtilis and Mycobacterium smegmatis, and against anaerobic gram-positive bacteria, such as Eubacterium cylindroides, Peptostreptococcus saccharoliticus, Propionibacterium acnes, Clostridium symbiosum, Clostridium perfringens and Clostridium difficile.
Comparison of the properties, chemical, physical and biological, given above of chloropolysporins B and C with those of known antibiotics leads to the conclusion that they belong to the class of glycopeptide antibiotics containing chlorine, such as v ancomycin, a voparcin α and β, actinoidins A and B or A-35512 B. However, chloropolysporins B and C can be clearly distinguished from these known antibiotics on the basis of the differences shown in the following Table 5. Specifically they have different neutral saccharide components and different amino acids are produced on acid hydrolysis. Moreover, they move a different distance on high voltage paper electrophoresis (HVPE,3300 volts/60 cm, 1 hour, pH 7.5 in 0.1 M tris-hydrochloric acid buffer solution), and they have different chlorine contents.
TABLE 5______________________________________ Neutral ChlorineAnti- saccha- contentbiotic ride Amino acid Distance (%)______________________________________Van- Glucose Aspartic acid 4.89comycin N-methylleucineAvo- Glucose, 4-Hydroxyphenyl- 9.4 cm 1.85parcin α Mannose, glycine, .sub.-- N-methyl- Rhamnose -p-hydroxyphenyl- glycineAvo- Glucose, 3-Chloro-4-hydroxy- 9.4 cm 3.65parcin β Mannose, phenylglycine, .sub.-- N- Rhamnose methyl- -p-hydroxy- phenylglycineActi- Glucose, 4-Hydroxyphenyl- 2.02noidin A Mannose glycine, Phenyl- alanineActi- Glucose, 2-Chloro-3-hydroxy- 3.96noidin B Mannose, phenylglycine, PhenylalanineA-35512B Glucose, 1.82 Mannose, Rhamnose, FucoseActa- Glucose, 1.96planin Mannose RhamnoseRisto- Glucose, 0cetin A Mannose Rhamnose ArabinoseRisto- Glucose, 0cetin B Mannose, RhamnoseChloro- Glucose, 3-Chloro-4- 4 cm 5.11poly- Mannose, hydroxyphenyl-sporin B Rhamnose glycine, .sub.-- N-methyl- -p-hydroxyphenyl- glycineChloro- Glucose, 3-Chloro-4- 4 cm 5.62poly- Mannose hydroxyphenyl-sporin C glycine, .sub.-- N- methyl- -p-hdroxy- phenylglycine______________________________________
The value reported above as "Distance" is the distance of movement on high voltage paper electrophoresis, measured using bioautography with Bacillus subtilis PCI 219 as the test organism.
From the above findings, it can be seen that chloropolysporins B and C can be used as antibiotics against various diseases caused by bacterial infections. The route of administration can vary widely and may be parenteral (e.g. by subcutaneous intravenous or intramuscular injection or by suppository) or oral (in which case it may be in the form of a tablet, capsule, powder or granule). The dose will, of course, vary with the nature of the disease to be treated, the age, condition and body weight of the patient and the route and time of administration; however, for an adult human patient, a daily dose of from 0.1 to 1.0 grams is preferred and this may be administered in a single dose or in divided doses.
Moreover, in view of the strong activity of chloropolysporins B and C against infectious bacteria of the genus Clostridium, they can be expected to be valuable growth-promoting agents for veterinary use. Bacteria of the genus Clostridium, particularly Clostridium perfringens and Clostridium difficile, are often present in the intestines of farm animals and are the cause of diarrhoea. Since chloropolysporins B and C have a strong activity against such microorganisms, they would suppress the growth of such microorganisms in the intestines and thus improve the microbial balance of the intestines. This, in turn, would improve feed efficiency thus contributing to weight gain and improved milk production in various farm animals, including ruminants, pigs and poultry. Moreover, chloropolysporins B and C, in common with the other glycopeptide antibiotics, are likely to have a low rate of absorption through the digestive organs and as a result, where the chloropolysporin B or C is administered in the feed little will remain in the animal body and hence in animal products, such meat, milk or eggs. When the chloropolysporin B or C is used as a growth-promoting agent for animals, it is preferably administered orally. Although it may be formulated into an edible composition with any suitable carrier or diluent, it is particularly convenient to administer it in admixture with an animal feed or with drinking water. When the chloropolysporin B or C is used as a feed additive, it may be mixed alone with the feed or it may be mixed in combination with other non-toxic edible excipients, nutrient supplements (e.g. vitamins, minerals or amino-acids), other antibiotics, anticoccidial agents or enzymes. For administration to animals as a growth-promoting agent, the chloropolysporin B or C need not necessarily be in a completely purified form and it may be used in a crude or partially purified form, as obtained at any desired stage during the extraction and purification described above. For use as a growth-promoting agent, chloropolysporin B or C is preferably employed in an amount of from 1 to 200, more preferably from 5 to 60, ppm by weight on the basis of the feed, drinking water or other carrier to which it is added; where an impure form of chloropolysporin B or C is employed, a concentration having equivalent activity is used.
Animals to which chloropolysporin B or C can be administered include farm mammals (e.g. cattle, horses, swine, sheep and goats). poultry (e.g. chickens, turkeys and ducks) and pet animals (e.g. dogs, cats and birds). Most significantly, when chloropolysporin B or C is administered orally to animals, their growth is effectively promoted, but it is little absorbed from the gastro-intestinal tract and it exhibits low retention in animal tissues: thus, there is an almost complete absence of chloropolysporin B or C residues in the products (e.g. milk, meat or eggs) of animals to which it has been administered, which is a great advantage from the view point of food hygiene.
The invention is further illustrated by the following examples.
EXAMPLE 1
Preparation of Chloropolysporins B and C
One loopful growth of Micropolyspora sp. SANK 60983 was inoculated into a 500 ml Erlenmeyer flask containing 80 ml of medium A, which has the following composition percentages are by weight):
______________________________________MEDIUM A______________________________________Glucose 3%Pressed yeast 1%Soybean meal 3%Calcium carbonate 0.4%Magnesium sulfate 0.2%Anti-foaming agent (Nissan CB-442) 0.01%Water the balance(adjusted to pH 7.0)______________________________________
The microorganism was then cultured for 84 hours at 28° C., using a rotary shaker at 220 r.p.m.
25 ml of the resulting seed culture were inoculated into each of four 2 liter Erlenmeyer flasks, each containing 500 ml of medium B which has the following composition. (percentages are by weight):
______________________________________MEDIUM B______________________________________Glucose 5%Yeast extract 0.1%Soybean meal 1%Polypepton (a Product of Daigo 0.4%Eiyo Co. Ltd., Japan)Beef extract 0.4%Sodium chloride 0.25%Calcium carbonate 0.5%Anti-foaming agent (Nissan CB-442) 0.01%Water the balance(adjusted to pH 7.2)______________________________________
The microorganism was then cultured at 28° C. for 24 hours, using a rotary shaker at 220 r.p.m.
The resulting cultured broths were combined. 750 ml of this broth were then inoculated into each of two 30 liter jar fermentors, each containing 15 liters of medium B and the microorganism was then cultured at 28° C. for 69 hours. Whilst aerating at the rate of 15 liters per minute and stirring.
At the end of this time, batches of cultured broth separately cultivated as described aboVe were combined to give a total of 30 liters of cultured broth. CELITE 545 (a registered trade mark for a product of Johns-Manville Products Corp, New Jersey, U.S.A.) a diatomaceous filter aid was added to the cultured broth and the mixture was filtered, to give 30 liters of a filtrate. This filtrate was adsorbed on 3 liters of DIAION HP 20 (a product of Mitsubishi Chemical Industries Co., Ltd ), and the adsorbent was washed with water and then eluted with 50% v/v aqueous acetone. Acetone was evaporated from the combined active fractions by evaporation under reduced pressure; and the concentrate thus obtained was lyophilized, giving 44 g of a crude powder.
41 g of this powder were dissolved in water and adsorbed onto 1.8 liters of DIAION HP 20, washed with 5 liters of water and 2 liters of 10% v/v aqueous acetone and then eluted with 4 liters of 50% v/v aqueous acetone. The active fractions from the elution were collected and condensed to a volume of 1 liter by evaporation under reduced pressure. The condensate was centrifuged at 5000 r.p.m. and the resulting precipitate was dried, to give 9.6 g of crude powder containing chloropolysporins B and C.
This crude powder was dissolved in 1 liter of 50% v/v aqueous methanol and then adsorbed onto 200 ml of acidic alumina (a product of Woelm Pharma, West Germany), which had previously been equilibrated with 50% v/v aqueous methanol. The adsorbed product was then eluted with the same solvent, and the active fractions, a total of 1.1 liters, were collected. The combined active fractions were passed through 60 ml of Dowex 21 K (OH - ), and eluted with water. The active fractions from this elution, a total volume of 1.2 liters, were collected and then condensed by evaporation under reduced pressure to a volume of 30 ml. This condensate was lyophilized, to give 1.23 g of powder. The powder was dissolved in aqueous hydrochloric acid of pH 4.0 and then adsorbed onto 56 g of polyamide filled with water (a product of Woelm Pharma, West Germany). This was subjected to gradient elution with 400 ml of water and 1 2 liters of methanol, in 20 ml fractions up to fraction 80 . Fractions 30-60 were collected and combined. The methanol was distilled off under reduced pressure and the resulting concentrate was lyophilized, to give 738 mg of a white powder containing chloropolysporins B and C.
4.4 g of this crude white powder containing chloropolysporins B and C were dissolved in 80 ml of a mixed solvent consisting of 15 parts of acetonitrile and 85 parts of a buffer solution (containing 0.2% w/v sodium heptanesulfonate. 2.5% w/v acetic acid and 0.5% w/v concentrated aqueous ammonia); the solution was then adsorbed on a System 500 chromatography system (a product of Waters Co), using a Preppack C 18 cartridge. This Was developed and eluted with the same mixed solvent as mentioned above at a flow rate of 100-150 ml per minute. Chloropolysporin B was eluted in the solvent after between 800 ml and 1700 ml of the eluant had passed through the cartridge, whilst chloropolysporin C was eluted after between 1700 and 4700 ml of the eluant had passed.
The active fractions containing chloropolysporin B were collected and adjusted to a pH value of 7.0. They were then concentrated by evaporation under reduced pressure, to distill off the acetonitrile. The resulting concentrated solution was adsorbed on a DIAION HP 20 column (100 ml) washed with water, and then eluted with 500 ml of 70% v/v aqueous acetone. The eluate was condensed by evaporation under reduced pressure, and the residue was lyophilized to afford chloropolysporin B heptanesulfonate as a powder.
200 mg of this powder were dissolved in 5 ml of water, and then 1 ml of a 10% w/v aqueous solution of sodium dodecylsulfate was dropped into the resulting solution. The precipitate which formed was collected by centrifugation at 3000 rpm for 10 minutes. This precipitate was suspended in water and the suspension was again centrifuged at 3000 rpm for 10 minutes to wash the precipitate. This operation was repeated a further three times to wash the precipitate. The precipitate was then dissolved in 3 ml of methanol and the insoluble residue was filtered off. 2 ml of a 0.5 M methanolic solution of triethylamine sulfate were added dropwise and the resulting precipitate was collected by centrifugation at 3000 rpm for 10 minutes. This precipitate was suspended in a small amount of methanol and again centrifuged at 3000 rpm for 10 minutes. This was repeated a further three times to wash the precipitate. The precipitate was then dissolved in 1.5 ml of water and the insoluble residue was filtered off. Lyophilization of the filtrate gave 65 mg of chloropolysporin B sulfate.
The active fractions containing the chloropolysporin C were collected and adjusted to a pH value of 7.0. They were then concentrated by evaporation under reduced pressure to distill off the acetonitrile, and the concentrate was adsorbed on a DIAION HP 20 column (50 ml). washed with water, and then eluted with 300 ml of 70% V/v aqueous acetone. The eluate was condensed by evaporation under reduced pressure, and the residue was lyophilized to afford 1.0 g of a powder containing chloropolysporin C heptanesulfonate. This powder was dissolved in 10 ml of a mixed solvent consisting of 15 parts of acetonitrile and 85 parts of a buffer solution (containing 0.2% w/v sodium heptanesulfonate, 2.5% w/v acetic acid and 0.5% w/v concentrated aqueous ammonia) and each 2 ml of the resulting solution was adsorbed on a Lobar column RP-18 (size B, a product of Merck and Co). This was developed and eluted at 13 ml per minute with the same mixed solvent, and the chloropolysporin C was eluted 30-40 minutes after commencement of the elution, whilst the contaminating chloropolysporin B was eluted between 18 and 20 minutes. This operation was repeated a total of 5 times.
The chloropolysporin C fractions were collected and adjusted to a pH value of 5.8. They were then concentrated by evaporation under reduced pressure. The concentrate was adsorbed onto 40 ml of DIAION HP 20, washed with water and eluted with 200 ml of 50% v/v aqueous acetone. The eluate was condensed by evaporation under reduced pressure, and the residue was lyophilized, to give 250 mg of a crude chloropolYsporin C-containing powder. This powder was dissolved in 5 ml of 50% v/v aqueous methanol, and the solution was adsorbed on 150 ml of Toyopearl HW40F (a product of Toyo Soda Co Ltd), which had previously been equilibrated with 50% v/v aqueous methanol. The column was developed and eluted with 50% v/v aqueous methanol at a flow rate of 0.6 ml per minute. The eluate was collected in fractions of 2.5 ml each, and the chloropolysporin C heptanesulfonate was found to be present in fractions 51-64.
These fractions were combined and then condensed under reduced pressure, and then 1 ml of a 10% w/v aqueous solution of sodium dodecylsulfate was added dropwise. The resulting precipitate was collected by contrifugation at 3000 rpm for 10 minutes. The precipitate was then suspended in water and washed by centrifugation at 3000 rpm for 10 minutes. These operations were repeated a further three times. The precipitate was then dissolved in 3 ml of methanol and the insoluble residue was filtered off. 2 ml of a 0.5 M methanolic solution of triethylamine sulfate were then added dropwise to the filtrate and the resulting precipitate was collected by centrifugation at 3000 rpm for 10 minutes. This precipitate was suspended in methanol and washed by centrifugation at 3000 rpm for 10 minutes. This operation was repeated a further three times. The resulting precipitate was dissolved in 1.5 ml of water, the insoluble residue was removed, and the solution was lyophilized to afford 54 mg of chloropolysporin C sulfate.
The chloropolysporin B sulfate and chloropolysporin C sulfate obtained as described above had the properties heretofor described.
EXAMPLE 2
1 loopful growth of Micropolyspora sp. SANK 60983 was inoculated into a 500 ml Erlenmeyer flask containing 80 ml of medium A, having the composition described in Example 1. It was then cultivated at 28° C. for 72 hours, using a rotary shaker at 220 rpm. 25 ml of this seed culture were inoculated into each of six 2 liter Erlenmeyer flasks, each containing 500 ml of medium B, having the composition described in Example 1, and cultivated for 24 hours at 28° C.
The whole of the cultured broth was then inoculated into a 100 liter tank containing 60 liters of medium B and cultivated at 28° C. for a fur(her 24 hours.
15 liters of the resulting seed culture were then inoculated into each of two 600 liter tanks, each containing 300 liters of medium B, and the microorganism was cultivated, whilst stirring, for 67 hours at 28° C., with aeration at the rate of 300 liters per minute, with an internal pressure of 1.0 kg/cm 2 and with 3-5 ppm of dissolved oxygen.
At the end of the cultivation period, a Celite 545 filter aid was added to the culture and the culture was filtered, to afford 550 liters of filtrate. This filtrate was passed through a DIAION HP 20 column (60 liters) to adsorb the chloropolysporin B. The column was washed with water and eluted with 50% v/v aqueous acetone, yielding 570 liters of active fractions. The acetone was then distilled off under reduced pressure, leaving 280 liters of a concentrate. This concentrate was extracted twice, each time with 200 liters of butanol to remove the impurities, and the residual aqueous layer was condensed to 5 liters by evaporation under reduced pressure. The concentrated solution was adjusted to a pH value of 5 8 by the addition of 1 N aqueous sodium hydroxide, and then the solution was adsorbed on a column containing 4.2 liters of polyamide gel (a product of Woelm Pharma, West Germany), and developed and eluted with water. The eluate was separated in fractions of 1 liter each, and chloropolysporin B was eluted in fractions 3-9. These fractions were combined, and adjusted to a pH value of 4.0 by the addition of 1 N aqueous hydrochloric acid. The resulting 7 liters of active fractions were condensed by evaporation under reduced pressure, and the residue was lyophilized to give 42 g of chloropolysporin B hydrochloride.
Elemental analysis:
Calculated for
C 83 H 89 O 34 N 8 Cl 3 .0.5HCl.4H 2 O:
C, 51.41%; H, 5.07%; N, 5.78%; Cl, 6.40%
Found:
C, 51.05%; H, 5.37%; N, 6.36%; Cl, 6.90%.
Following the same procedure as described in Example but employing the chloropolysporin C-containing fractions, chloropolysporin C hydrochloride was also produced.
Elemental analysis:
Calculated for
C 77 H 79 O 30 N 8 Cl 3 .HCl.9H 2 O:
C, 48.64%; H, 5.19%; N, 5.89%; Cl, 7.45%.
Found:
C, 48.48%; H, 5.13%; N, 5.81%; Cl, 7.78%.
EXAMPLE 3
Capsules for Oral Use
The following ingredients were mixed:
______________________________________Chloropolysporin B hydrochloride 100 mgLactose 100 mgCorn starch 148.5 mgMagnesium stearate 1.5 mg______________________________________
The mixture was sieved through a 30 Tyler standard mesh sieve, giving 350 mg of a fine powder, which was put into a No. 2 gelatin capsule.
EXAMPLE 4
The procedure described in Example 3 was repeated, except that chloropolysporin C hydrochloride was employed in place of chloropolysporin B hydrochloride. | Novel compounds, called chloropolysporins B and C, and salts thereof have antibiotic properties and would appear to be members of the class of glycopeptide antibiotics containing chlorine. They may be produced by cultivating a suitable strain of microorganism of the genus Micropolyspora, especially Micropolyspora sp. SANK 60983 (FERM BP-538). They may be combined with conventional pharmaceutically acceptable carriers or diluents for therapeutic use or incorporated into edible excipients, such as feed or water, for use as a growth-promoting agent, especially for farm animals. | 2 |
RELATED APPLICATION DATA
This application is a divisional patent application of patent application Ser. No. 11/352,755, filed 13 Feb. 2006, entitled THERMALLY INSULATED PHASE CHANGE MEMORY DEVICE AND MANUFACTURING METHOD, which application is incorporated herein by reference, which claims the benefit of U.S. Provisional Patent Application No. 60/736,721, filed 15 Nov. 2005, entitled THERMALLY CONTAINED/INSULATED PHASE CHANGE MEMORY DEVICE AND METHOD.
PARTIES TO A JOINT RESEARCH AGREEMENT
International Business Machines Corporation, a New York corporation; Macronix International Corporation, Ltd., a Taiwan corporation, and Infineon Technologies A.G., a German corporation, are parties to a Joint Research Agreement.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to high density memory devices based on programmable resistive memory materials, including phase change materials and other materials, and to methods for manufacturing such devices.
2. Description of Related Art
Phase change based memory materials are widely used in read-write optical disks. These materials have at least two solid phases, including for example a generally amorphous solid phase and a generally crystalline solid phase. Laser pulses are used in read-write optical disks to switch between phases and to read the optical properties of the material after the phase change.
Phase change based memory materials, like chalcogenide based materials and similar materials, also can be caused to change phase by application of electrical current at levels suitable for implementation in integrated circuits. The generally amorphous state is characterized by higher resistivity than the generally crystalline state; this difference in resistance can be readily sensed to indicate data. These properties have generated interest in using programmable resistive material to form nonvolatile memory circuits, which can be read and written with random access.
The change from the amorphous to the crystalline state is generally a lower current operation. The change from crystalline to amorphous, referred to as reset herein, is generally a higher current operation, which includes a short high current density pulse to melt or breakdown the crystalline structure, after which the phase change material cools quickly, quenching the phase change process, allowing at least a portion of the phase change structure to stabilize in the amorphous state. It is desirable to minimize the magnitude of the reset current used to cause transition of phase change material from crystalline state to amorphous state. The magnitude of the reset current needed for reset can be reduced by reducing the size of the phase change material element in the cell and by reducing the size of the contact area between electrodes and the phase change material, so that higher current densities are achieved with small absolute current values through the phase change material element.
One direction of development has been toward forming small pores in an integrated circuit structure, and using small quantities of programmable resistive material to fill the small pores. Patents illustrating development toward small pores include: Ovshinsky, “Multibit Single Cell Memory Element Having Tapered Contact,” U.S. Pat. No. 5,687,112, issued Nov. 11, 1997; Zahorik et al., “Method of Making Chalogenide [sic] Memory Device,” U.S. Pat. No. 5,789,277, issued Aug. 4, 1998; Doan et al., “Controllable Ovonic Phase-Change Semiconductor Memory Device and Methods of Fabricating the Same,” U.S. Pat. No. 6,150,253, issued Nov. 21, 2000; Chen, “Phase Change Memory Device Employing Thermally Insulating Voids,” U.S. Pat. No. 6,815,704 B1, issued Nov. 9, 2004.
Problems have arisen in manufacturing such devices with very small dimensions, and with variations in process that meet tight specifications needed for large-scale memory devices. It is desirable therefore to provide a memory cell structure having small dimensions and low reset currents, and a method for manufacturing such structure.
SUMMARY OF THE INVENTION
A first aspect of the invention is directed to a thermally insulated memory device comprising a memory cell access layer and a memory cell layer, operably coupled to the memory cell access layer. The memory cell layer comprises a memory cell, the memory cell comprising: first and second electrodes having opposed, spaced apart electrode surfaces; a via extending between the electrode surfaces; a thermal insulator within the via, the thermal insulator comprising a sidewall structure in the via defining a void extending between the electrode surfaces; and a memory material such as a phase change material, within the void electrically coupling the electrode surfaces. The thermal insulator helps to reduce the power required to operate the memory material. In some embodiments the memory cell layer comprises an inter-electrode insulator made using a dielectric material through which the via extends, and the thermal insulator has a thermal insulation value greater than a thermal insulation value of the dielectric material of the inter-electrode layer. The thermal insulator may define a sidewall structure having an inside surface tapering inwardly from the electrode surface of the second electrode towards the electrode surface of the first electrode so that a cross-sectional area of the insulated via is smaller at the first electrode than at the second electrode, forming a void having a constricted region near the first electrode member, the memory material element filling the constricted region. The memory cell access layer may comprise an outer surface and an electrically conductive plug extending to the outer surface from underlying terminals formed for example by doped regions in a semiconductor substrate, the plug having a plug surface, the plug surface constituting a portion of the outer surface of the electrode layer. The first electrode overlies at least a substantial portion of the plug surface; whereby at least some imperfections at the plug surface are accommodated by the first electrode. In embodiments described herein, the electrode surface first electrode is substantially planar, in the region of the via, where the substantially planar surface can be formed for example by chemical mechanical polishing or other planarizing procedures that intend to improve the planarity of the electrode surface relative to the electrode material as deposited over the imperfections, and prior to planarization.
A second aspect of the invention is directed to a method for making a thermally insulated memory device. A memory cell access layer is formed on a substrate, the memory cell access layer comprising an upper surface. A first electrode layer is deposited and planarized on the upper surface. An inter-electrode layer is deposited on the first electrode layer. A via is created within the inter-electrode layer. A thermal insulator having an open region is formed within the via, by for example forming sidewall structures on sidewalls of the via. A memory material is deposited within the open region. A second electrode layer is deposited over and in contact with the memory material. According to some embodiments the material of the thermal insulator has a thermal insulation value greater than (or stated oppositely, thermal conductivity less than) the thermal insulation value of the dielectric material used for the inter-electrode layer.
A third aspect of the invention is directed to plug-surface void-filling memory device comprising a memory cell access layer comprising an outer surface and an electrically conductive plug extending to the outer surface, the plug having a plug surface, the plug surface constituting a portion of the outer surface, the plug surface having an imperfection; and a memory cell layer contacting the memory cell access layer, the memory cell layer comprising a memory cell. The memory cell comprises first and second electrodes having opposed, spaced apart electrode surfaces, the first electrode contacting at least a substantial portion of the plug surface; and a memory material electrically coupling the electrode surfaces to create a memory material element; whereby the imperfection at the plug surface is accommodated by the first electrode. In some embodiments a void-type imperfection at the plug surface is filled by depositing and planarizing the material used to form the first electrode.
A fourth aspect of the invention is directed to a method for accommodating an imperfection in an outer surface of an electrically conductive plug of a semiconductor device. The method comprises depositing an electrode on the outer service of the plug.
The method described herein for formation of the phase change element for use in a memory cell in a phase change random access memory (PCRAM) device, can be used to make small phase change elements, bridges or similar structures for other devices.
Various features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross-sectional view of a phase change memory device made according to the invention;
FIGS. 2-11 illustrate a method for making phase change memory devices, such as the device of FIG. 1 ;
FIG. 2 illustrates the final stages for making the memory cell access layer of FIG. 1 ;
FIG. 3 illustrates the deposition of a first electrode layer on top of the memory cell access layer of FIG. 2 ;
FIG. 4 illustrates the result of depositing an inter-layer dielectric onto the first electrode layer of FIG. 3 ;
FIG. 5 shows vias formed in the inter-layer dielectric of FIG. 4 ;
FIG. 6 illustrates thermal insulators deposited as sidewall structures within the vias of FIG. 5 ;
FIG. 7 shows phase change material deposited within the open regions of the thermal insulators of FIG. 6 ;
FIG. 8 illustrates a second electrode layer deposited onto the structure of FIG. 7 ;
FIG. 9 illustrates the formation of a lithographic mask overlying certain areas on the second electrode layer for memory cell isolation;
FIG. 10 illustrates the result of etching the structure of FIG. 9 ; and
FIG. 11 shows the structure of FIG. 10 after deposition of a dielectric fill within the etched regions.
FIG. 12 illustrates an alternative embodiment of a phase change memory device.
DETAILED DESCRIPTION
The following description of the invention will typically be with reference to specific structural embodiments and methods. It is to be understood that there is no intention to limit the invention to the specifically disclosed embodiments and methods but that the invention may be practiced using other features, elements, methods and embodiments. Like elements in various embodiments are commonly referred to with like reference numerals.
FIG. 1 is a simplified cross-sectional view of a phase change memory device 10 made according to one embodiment of the invention. Device 10 comprises broadly a memory cell access layer 12 formed on a substrate, not shown, and a memory cell layer 14 formed on top of access layer 12 . Access layer 12 typically comprises access transistors; other types of access devices may also be used. Access layer 12 comprises first and second polysilicon word lines acting as first and second elements 16 , 18 , first and second plugs 20 , 22 and a common source line 24 all within a dielectric fill layer 26 . A memory cell overlies the plug 20 in the access layer, and comprises bottom electrode member 57 , thermally insulating sidewalls structures 42 , programmable resistive material element 46 and top electrode member 59 . Overlying bit line structures 62 are coupled to the top electrode member 59 .
Phase change memory device 10 and its method of manufacturer will be described with reference to FIGS. 2-11 . Referring now to FIG. 2 , memory cell access layer 12 is seen to have a generally flat upper surface 28 , the upper surface being interrupted by voids 30 formed in plugs 20 , 22 and by void 32 formed in common source line 24 . Voids 30 , 32 , or other surface imperfections, are formed for example as an artifact of the deposition process used for formation of tungsten plugs within small dimension vias. Deposition of a memory material directly onto the upper surfaces 33 of plugs 20 , 22 can create a distribution problem, that is create an increased variance in the operational characteristics of the devices, and in the amount of memory material in each memory element due to the existence of voids 30 .
FIG. 3 illustrates the results of TiN deposition to create a first electrode layer 34 and chemical mechanical polishing CMP of layer 34 to create a planarized surface 36 . Layer 34 is preferably about 100 to 800 nm thick, typically about 500 nm thick after planarization. First electrode layer 34 fills voids 30 , 32 to effectively eliminate the distribution problem that could be created by the voids or other surface imperfections. Planarization removes artifacts of the voids that result from deposition of the electrode material layer 34 over the imperfections. An inter-electrode layer 38 , see FIG. 4 , is deposited on layer 34 . Layer 38 may comprise one or more layer of an electrical insulator such as silicon dioxide, or variants thereof, is preferably about 40 to 80 nm thick, typically about 60 nm thick for the illustrated example. Vias 40 , see FIG. 5 , are formed in inter-electrode layer 38 , typically using an appropriate lithographic mask, not shown, generally centered, within alignment tolerances of the manufacturing processes, above plugs 20 , 22 . Vias 40 have a diameter of about the technology node, that is about 90 to 150 nm, typically about 130 nm for a technology node having a minimum lithographic feature size of 0.13 microns.
A thermal insulator 42 is formed within each via 40 , using a conformal deposition process such as chemical vapor deposition (CVD). Thermal insulator 42 is a better thermal insulator than the material of inter-electrode layer 38 , preferably at least 10% better. Therefore, when the inter-layer dielectic comprises silicon dioxide, the thermal insulator 42 preferrably has a thermal conductivity value “kappa” of less than that of silicon dioxide which is 0.014 J/cm*K*sec. Representative materials for thermal insulator 42 include materials that are a combination of the elements silicon Si, carbon C, oxygen O, fluorine F, and hydrogen H. Examples of thermally insulating materials which are candidates for use as thermal insulator 42 include SiCOH, polyimide, polyamide, and fluorocarbon polymers. Other examples of materials which are candidates for use for thermal insulator 42 include fluorinated SiO 2 , silsesquioxane, polyarylene ethers, parylene, fluoro-polymers, fluorinated amorphous carbon, diamond like carbon, porous silica, mesoporous silica, porous silsesquioxane, porous polyimide, and porous polyarylene ethers. In other embodiments, the thermally insulating structure comprises a gas-filled void lining the walls of via 40 . A single layer or combination of layers can provide thermal insulation.
Thermal insulator 42 is preferably formed as sidewall structure to create the generally conical, downwardly and inwardly tapering central open region 44 shown in FIG. 6 . For example, the thermal insulator 42 can be formed by depositing a conformal layer of the material over the vias, and anisotropically etching the layer to expose the bottom electrode surface leaving the sidewall structures, with open region 44 to define a thermally insulated via. Open region 44 could have other constricting shapes, such as an hourglass shape, a reverse conical shape or a staircase or otherwise stepped shape. It may also be possible to make open region with a constant, appropriately small cross-sectional size and thus without a constricted area. The shape of open region 44 may be the result of the deposition process chosen for the deposition of thermal insulator 42 ; the deposition of thermal insulator 42 may also be controlled to result in the desired, typically constricting, shape for open region 44 . Processing steps may be also undertaken after deposition of thermal insulator 42 to create the desired shape for open region 44 . FIG. 7 illustrates a result of depositing a phase change material 46 within central open region 44 , followed by chemical mechanical polishing to create a surface 47 . Phase change material 46 is thermally insulated from layer 38 by thermal insulator 42 . The downwardly and inwardly tapering shape of thermal insulator 42 creates a narrow transition region 48 of change material 46 to create a phase change element 49 at region 48 . Phase change material 46 is typically about 130 nm wide at surface 47 and about 30 to 70 nm, typically about 50 nm, at transition region 48 .
Both the smaller size of phase change element 49 at transition region 48 and the use of thermal insulator 42 reduce the current needed to cause a change between a lower resistivity, generally crystalline state and a higher resistivity, generally amorphous state for phase change element 49 .
FIG. 8 illustrates the results of TiN deposition and chemical mechanical polishing to create a second electrode layer 50 having a planarized surface 52 . Lithographic mask 54 is shown in FIG. 9 positioned overlying first and second plugs 20 , 22 and their associated thermal insulators 42 and phase change materials 46 . FIG. 10 illustrates the results of etching steps in which portions of second electrode layer 50 , silicon dioxide layer 38 and first electrode layer 34 not covered by mask 54 are removed using appropriate etching recipes according to the composition of the layers to create etched regions 56 and first and second electrode members 57 , 59 . Lithographic mask 54 is sized so that portions 61 of inter-electrode layer 38 are left surrounding thermal insulators 42 after the etching steps of FIG. 10 to prevent etching of thermal insulator 42 , which could be caused by conventional tolerances associated with conventional manufacturing steps.
FIG. 11 illustrates the results of a dielectric fill-in step in which an fill 58 , such as silicon dioxide, is deposited within etched regions 56 , reconstituting the inter-electrode layer 48 and filling between the memory cells, and followed by CMP to create planarized surface 60 . Thereafter, an electrically conductive material 62 is deposited on surface 60 and patterned to create bit lines for the phase change memory device 10 , including memory cells 64 , shown in FIG. 1 . Electrically conductive material 62 is typically copper or aluminum, or alloys thereof, but it also may be tungsten, titanium nitride or other materials and combinations of materials.
In an alternative embodiment, as shown in FIG. 12 , the bottom electrode 57 comprises a multilayer structure. As shown in FIG. 12 , the electrode 57 includes a first layer 57 A corresponding to bottom electrode 57 of FIG. 11 , and a second layer 57 B. Second layer 57 B separates first layer 57 A from phase change element 49 at region 48 of phase change material 46 .
Electrodes 57 , 59 in the illustrated embodiments are preferably TiN. Although other materials, such as TaN, TiAlN or TaAlN, or composite structures comprising copper or tungsten for example with thin film diffusion barriers made of TiN or other materials, may be used for electrodes 57 , 59 . TiN is presently preferred because it makes good contact with GST (discussed below) as phase change material 46 , it is a common material used in semiconductor manufacturing, and it provides a good diffusion barrier at the higher temperatures at which phase change material 46 transitions, typically in the 600-700° C. range. Plugs 20 , 22 and common source line 24 are typically made of tungsten or other suitable materials.
Embodiments of the memory cell include phase change based memory materials, including chalcogenide based materials and other materials, for phase change material 46 . Chalcogens include any of the four elements oxygen (O), sulfur (S), selenium (Se), and tellurium (Te), forming part of group VI of the periodic table. Chalcogenides comprise compounds of a chalcogen with a more electropositive element or radical. Chalcogenide alloys comprise combinations of chalcogenides with other materials such as transition metals. A chalcogenide alloy usually contains one or more elements from column six of the periodic table of elements, such as germanium (Ge) and tin (Sn). Often, chalcogenide alloys include combinations including one or more of antimony (Sb), gallium (Ga), indium (In), and silver (Ag). Many phase change based memory materials have been described in technical literature, including alloys of: Ga/Sb, In/Sb, In/Se, Sb/Te, Ge/Te, Ge/Sb/Te, In/Sb/Te, Ga/Se/Te, Sn/Sb/Te, In/Sb/Ge, Ag/In/Sb/Te, Ge/Sn/Sb/Te, Ge/Sb/Se/Te and Te/Ge/Sb/S. In the family of Ge/Sb/Te alloys, a wide range of alloy compositions may be workable. The compositions can be characterized as TeaGebSb100-(a+b).
One researcher has described the most useful alloys as having an average concentration of Te in the deposited materials well below 70%, typically below about 60% and ranged in general from as low as about 23% up to about 58% Te and most preferably about 48% to 58% Te. Concentrations of Ge were above about 5% and ranged from a low of about 8% to about 30% average in the material, remaining generally below 50%. Most preferably, concentrations of Ge ranged from about 8% to about 40%. The remainder of the principal constituent elements in this composition was Sb. These percentages are atomic percentages that total 100% of the atoms of the constituent elements. (Ovshinsky '112 patent, columns 10-11.) Particular alloys evaluated by another researcher include Ge 2 Sb 2 Te 5 , GeSb 2 Te 4 and GeSb 4 Te 7 . (Noboru Yamada, “Potential of Ge—Sb—Te Phase-Change Optical Disks for High-Data-Rate Recording”, SPIE v. 3109, pp. 28-37 (1997).) More generally, a transition metal such as chromium (Cr), iron (Fe), nickel (Ni), niobium (Nb), palladium (Pd), platinum (Pt) and mixtures or alloys thereof may be combined with Ge/Sb/Te to form a phase change alloy that has programmable resistive properties. Specific examples of memory materials that may be useful are given in Ovshinsky '112 at columns 11-13, which examples are hereby incorporated by reference.
Phase change alloys are capable of being switched between a first structural state in which the material is in a generally amorphous solid phase, and a second structural state in which the material is in a generally crystalline solid phase in its local order in the active channel region of the cell. These alloys are at least bistable. The term amorphous is used to refer to a relatively less ordered structure, more disordered than a single crystal, which has the detectable characteristics such as higher electrical resistivity than the crystalline phase. The term crystalline is used to refer to a relatively more ordered structure, more ordered than in an amorphous structure, which has detectable characteristics such as lower electrical resistivity than the amorphous phase. Typically, phase change materials may be electrically switched between different detectable states of local order across the spectrum between completely amorphous and completely crystalline states. Other material characteristics affected by the change between amorphous and crystalline phases include atomic order, free electron density and activation energy. The material may be switched either into different solid phases or into mixtures of two or more solid phases, providing a gray scale between completely amorphous and completely crystalline states. The electrical properties in the material may vary accordingly.
Phase change alloys can be changed from one phase state to another by application of electrical pulses. It has been observed that a shorter, higher amplitude pulse tends to change the phase change material to a generally amorphous state. A longer, lower amplitude pulse tends to change the phase change material to a generally crystalline state. The energy in a shorter, higher amplitude pulse is high enough to allow for bonds of the crystalline structure to be broken and short enough to prevent the atoms from realigning into a crystalline state. Appropriate profiles for pulses can be determined, without undue experimentation, specifically adapted to a particular phase change alloy. A material useful for implementation of a PCRAM described herein is Ge 2 Sb 2 Te 5 , commonly referred to as GST. Other types of phase change materials can also be used.
Other programmable resistive materials may be used in other embodiments of the invention, including N 2 doped GST, Ge x Sb y , or other material that uses different crystal phase changes to determine resistance; Pr x Ca y MnO 3 , PrSrMnO, ZrOx, or other material that uses an electrical pulse to change the resistance state; 7,7,8,8-tetracyanoquinodimethane (TCNQ), methanofullerene 6,6-phenyl C61-butyric acid methyl ester (PCBM), TCNQ-PCBM, Cu-TCNQ, Ag-TCNQ, C60-TCNQ, TCNQ doped with other metal, or any other polymer material that has bistable or multi-stable resistance state controlled by an electrical pulse. For example, another type of memory material that in some situations may be appropriate is a variable resistance ultra thin oxide layer.
For additional information on the manufacture, component materials, use and operation of phase change random access memory devices, see U.S. patent application Ser. No. 11/155,067, filed 17 Jun. 2005, entitled Thin Film Fuse Phase Change Ram And Manufacturing Method.
The invention has been described with reference to phase change materials. However, other memory materials, also sometimes referred to as programmable materials, can also be used. As used in this application, memory materials are those materials having electrical properties that can be changed by the application of energy; the change can be a stepwise change or a continuous change or a combination thereof.
The above descriptions may have used terms such as above, below, top, bottom, over, under, et cetera. These terms are used to aid understanding of the invention are not used in a limiting sense.
While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that modifications and combinations will occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims.
Any and all patents, patent applications and printed publications referred to above are hereby incorporated by reference. | A thermally insulated memory device includes a memory cell, the memory cell having electrodes with a via extending therebetween, a thermal insulator within the via and defining a void extending between the electrode surfaces. A memory material, such as a phase change material, is within the void and electrically couples the electrodes to create a memory material element. The thermal insulator helps to reduce the power required to operate the memory material element. An electrode may contact the outer surface of a plug to accommodate any imperfections, such as the void-type imperfections, at the plug surface. Methods for making the device and accommodating plug surface imperfections are also disclosed. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to a vehicle detection device which detects the presence or absence of a peripheral vehicle based on an image captured by an on-vehicle camera, a vehicle detection method and a vehicle detection program. More particularly, the present invention relates to a vehicle detection device which detects a peripheral vehicle located anterior to or posterior to the vehicle itself, a vehicle detection method and a vehicle detection program.
BACKGROUND ART
[0002] Conventionally, some devices capable of detecting a vehicle being in peripheral of the vehicle itself by using an on-vehicle camera and notifying the driver of the presence thereof, have been disclosed. As a typical algorism of a vehicle detection technology for detecting a peripheral vehicle from an image captured by the on-vehicle camera, a method using pattern matching, with which the features of the vehicle previously set in an image format or a vector format are compared with various partial regions in the image and the presence or absence of the vehicle is determined, is known.
[0003] In such a method, however, if checking for the entire region of the image is performed even when there are numerous shapes and sizes of the features of vehicles, large amounts of calculation for checking are needed. Therefore, it has been difficult to detect a vehicle in real time.
[0004] In view of this, a vehicle detection technology has been known, and with this method, an assumed region which is assumed to be corresponding to a vehicle in an image is detected by using an algorism having less calculation amount and pattern matching is applied for only this assumed region.
[0005] As algorisms for detecting the assumed region used in the foregoing vehicle detection technology, an algorism for extracting a pair of vertical edges corresponding to both sides of a vehicle from the image and detecting an assumed region based on that, an algorism for extracting a black region from the image and detecting an assumed region based on the shape thereof, and an algorism for extracting a portion where the luminance variation is large in the longitudinal direction from the image and detecting an assumed region based on a variance value of a pixel value within a local region set so as to include the portion, are cited.
[0006] As the algorism for extracting a pair of vertical edges, Patent document 1 discloses a method for detecting a vehicle by verifying how much a pair of vertical edge line segments and horizontal edge line segments existing therebetween satisfies a reference relating to a vehicle respectively. Further, Non-patent document 1 discloses the method for determining whether it is a vehicle or not by voting for positions in a Hough space corresponding to the center position of a pair of vertical edge line segments and inputting the image of the partial region near the position getting a lot of votes into a neutral network discriminator.
[0007] As the algorism for extracting a black region, Patent documents 2 and 3 disclose a method for binarizing a monochrome image, after expanding the black region of the monochrome image so as to divide into a black region and a white region, and determining whether or not the black region corresponds to a vehicle based on the area, the barycenter position, the aspect ratio and the like of the black region after a denoising processing.
[0008] As the algorism for extracting a portion in which luminance variation is large in the longitudinal direction, Patent document 4 discloses the method for detecting a longitudinal axis coordinate that a pixel value indicating luminance changes drastically in a longitudinal direction, and determining that, if a variance value of a pixel value within a partial region set so as to include the longitudinal axis coordinate is larger than a reference value, the partial region corresponds to a vehicle. Patent document 4 described that this method is capable of discriminating a shadow of the vehicle from shadows of trees and the like by being based on the variance value in the partial region.
[0009] Non-patent document 1: “Vehicle Detection Technology Using Method of Feature Space Projection of Edge Pair”, VIEW 2005, Proceedings of Vision Engineering Workshop, by The Japan Society for Precision Engineering p. 160-165
[0010] Patent Document 1: Japanese Patent No. 3072730
[0011] Patent Document 2: Japanese Patent Application Laid-open No. H09-016751
[0012] Patent Document 3: Japanese Patent Application Laid-open No, H09-128548
[0013] Patent Document 4: Japanese Patent No. 3069952
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0014] However, the methods disclosed in Non-patent document 1 and Patent document 1 assume that there is luminance difference between pixels corresponding to a vehicle to be detected and pixels corresponding to the background region.
[0015] As shown in FIG. 11 , when there is a building 1201 having a low luminance value because it is in the shade, or when there is a black vehicle 1202 in front of roadside trees, or when vehicles 1203 and 1204 having the same body color are captured with an overlap, as luminance difference between pixels of the vehicle and the background becomes slight, there has been an inconvenience that a vertical edge may not be extracted.
[0016] Further, in the methods disclosed in Patent documents 2 and 3, the black regions such as shadows of roadside trees or buildings facing the road are extracted. Consequently, there has been inconvenience that the excessive number of partial regions is extracted as assumed regions if these shadows exist on the road surface.
[0017] The invention recited in Patent document 4 is capable of distinguishing shadows of vehicles from shadows of roadside trees or buildings facing the road and capable of limiting an assumed region more effectively, compared to the other methods described above. However, it is very difficult to set a reference value for determining whether or not it is an assumed region because a luminance distribution of pixels included in a partial region changes variously depending on circumstances. Further, the assumed region is extracted by determining whether or not it is the shadow of a vehicle by a valiance value, so there has been such an inconvenience that a partial region including road paints such as a crosswalk having strong contrast with the road is extracted as an assumed region by error.
[0018] It is therefore an object of the present invention to solve the problem described above and to provide a vehicle detection device which is capable of detecting exactly an assumed region which can be assumed to be representing a vehicle in an image captured by an on-vehicle camera and determining whether or not the assumed region is the image of a vehicle, and a vehicle detection method and a vehicle detection program.
Means for Solving the Problems
[0019] In order to achieve such an object, a vehicle detection device according to the present invention is a device for detecting the presence or absence of a peripheral vehicle based on an image captured by an on-vehicle camera and includes: a luminance creating unit for creating a brightness distribution of the captured image; a luminance threshold specifying unit for estimating and outputting an upper limit for a luminance value corresponding to the region of the vehicle bottom side of a peripheral vehicle by analyzing the brightness distribution of the image created by the luminance creating unit; and a vehicle detecting unit for deciding a vehicle assumed region including the vehicle bottom side having the luminance value not greater than the upper limit and for determining whether or not the image of the vehicle assumed region corresponds to a vehicle by a pattern matching method.
[0020] The present invention is established as a vehicle detection device as hardware, however, it is not limited to that. The present invention may be established as a vehicle detection program as software or a vehicle detection method.
[0021] A vehicle detection method according to the present invention is a method for detecting the presence or absence of a peripheral vehicle based on an image captured by an on-vehicle camera, and includes: creating a brightness distribution of the captured image; estimating and outputting an upper limit for a luminance value corresponding to the region of the vehicle bottom side of a peripheral vehicle by analyzing the brightness distribution of the image; and deciding a vehicle assumed region including the vehicle bottom side having the luminance value not greater than the upper limit and determining whether or not the image of the vehicle assumed region corresponds to a vehicle by a pattern matching method.
[0022] A vehicle detection program according to the present invention causes a computer configuring a vehicle detection device for detecting the presence or absence of a peripheral vehicle based on an image captured by an on-vehicle camera to execute: a function of creating a brightness distribution of the captured image; a function of estimating and outputting an upper limit for a luminance value corresponding to the region of the vehicle bottom side of a peripheral vehicle by analyzing the brightness distribution of the image created by the luminance creating unit; and a function of deciding a vehicle assumed region including the vehicle bottom side having the luminance value not greater than the upper limit and determining whether or not the image of the vehicle assumed region corresponds to a vehicle by a pattern matching method.
Effects of the Invention
[0023] According to the present invention, effective detection of a peripheral vehicle can be achieved by focusing on the fact that illuminance of a road surface and a tire running surface at the bottom side of a vehicle is lower than all other regions including shadows of roadside trees or buildings around the road in an image captured by an on-vehicle camera.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0024] Hereinafter, exemplary embodiments of the invention will be explained with reference to the drawings.
Exemplary Embodiment 1
[0025] FIG. 1 is a block diagram showing a configuration of a vehicle detection device according to a first exemplary embodiment of the invention.
[0026] As shown in FIG. 1 , the vehicle detection device according to the first exemplary embodiment of the invention includes: a luminance creating unit ( 12 ) for creating a brightness distribution of the image captured by an on-vehicle camera; a luminance threshold specifying unit 13 for estimating and outputting an upper limit for a luminance value corresponding to the region of the vehicle bottom side of a peripheral vehicle by analyzing the brightness distribution of the image created by the luminance creating unit ( 12 ); and a vehicle detecting unit 16 for deciding a vehicle assumed region including the vehicle bottom side having the luminance value not greater than the upper limit and for determining whether or not the image of the vehicle assumed region corresponds to a vehicle by a pattern matching method.
[0027] In the exemplary embodiment shown in FIG. 1 , a luminance histogram creating unit 12 for creating a luminance histogram of the captured image as the brightness distribution of the image is used as the luminance creating unit. In FIG. 1 , 1 means an image inputting unit 11 for inputting an image captured by an on-vehicle camera.
[0028] The vehicle detecting unit 16 includes a low luminance pixel extracting unit 14 and a vehicle assumed region extracting unit 15 . The low luminance pixel extracting unit 14 extracts low luminance pixels having the luminance value not greater than the upper limit output by the luminance threshold specifying unit 13 from the captured image. The vehicle assumed region extracting unit 15 decides the vehicle assumed region in which the low luminance pixels are included in the vehicle bottom side based on the preset positional relationship between the vehicle bottom side and the vehicle region.
[0029] The luminance histogram creating unit 12 shown in FIG. 1 creates a luminance histogram indicating a luminance distribution of an input image. The input image includes a grayscale image showing luminance or a color image. In the case of a color image, the luminance histogram creating unit 12 may create the luminance histogram by calculating the luminance value from the color information, or may create the luminance histogram by using a green component value which is contributing the most to the luminance value in place of the luminance value in order to omit the calculation of the luminance component and to speed up.
[0030] The luminance threshold specifying unit 13 presets the number of pixels of the shadow area of the road surface at the bottom side of the vehicle in the case of assuming that the vehicle to be detected is captured in the largest size in the image. And, the luminance threshold specifying unit 13 calculates percentage of the preset number of pixels for the total number of pixels of the input image, and then calculates the threshold so that the calculated percentage becomes equal to the percentage of cumulative pixels, which is accumulated from the lowest luminance up to the threshold in the luminance histogram, for the total number of pixels.
[0031] The estimation process of the threshold of the luminance by the luminance threshold specifying unit 13 will be explained with reference to FIG. 2 . FIG. 2 is a diagram showing an image captured by an on-vehicle camera.
[0032] In FIG. 2 , a tire running surface 203 of a vehicle 201 and a road surface 202 with which the tire running surface 203 is in contact are located at the bottom side of the vehicle 201 . A space 204 between the vehicle 201 and the road surface 202 is normally as short as a few dozens of centimeter. A direct light 205 of sun is blocked off by the vehicle 201 , and so amount of incident of the direct light 205 to the sides of the tire running surface 203 and the road surface 202 is extremely limited. Further, an indirect light 206 reflected from nearby objects is also blocked off by the vehicle 201 , and amount of incident of the indirect light 206 to the sides of the tire running surface 203 and the road surface 202 is very small. Therefore, regardless of the weather such as sunny, cloudy or rainy weather, the brightness of the road surface 202 and the tire running surface 203 located at the bottom side of the vehicle 201 becomes dark compared to the brightness of the region to which the direct light 205 and the indirect light 206 are directly incident. If the image region corresponding to the road surface and the tire running surface at the bottom side of the vehicle in the input image shall be the vehicle bottom region, a luminance value of pixels corresponding to the vehicle bottom region is limited below a certain value when camera parameters are fixed. This value shall be a first upper limit for a luminance value.
[0033] In the case of being captured by an on-vehicle camera, the captured image includes the road surface 202 and the tire running surface 203 at the bottom side of the vehicle, which has small amount of incident, the region outside of the vehicle 201 to which the direct light 205 and the indirect light 206 are directly incident, a shadow of roadside tree 207 on the road and a shadow 208 being the side of the vehicle itself. In this case, the illuminance within the image range captured by the on-vehicle camera becomes the lowest at the tire running surface 203 and the road surface 202 , at the bottom side of the vehicle, which has the smallest amount of incident of the direct light 205 and the indirect light 206 because of being blocked off by the vehicle 201 .
[0034] The luminance threshold specifying unit 13 therefore calculates in advance percentage of the area of the regions of the vehicle bottom sides ( 202 and 203 ) in the captured image size on condition that the area takes the maximum value. And then, the luminance threshold specifying unit 13 regards a luminance value at which the percentage of an accumulated luminance histogram, which is accumulated from the lower side of the luminance in the captured image, is equal to the percentage of the area on condition that the area of the vehicle bottom region takes the maximum value as a second upper limit for a luminance value, and calculates the smaller one of the first and the second upper limits for the luminance value as a threshold. In the case where a plurality of vehicles could be included in the captured image, the second upper limit for the luminance value may be obtained based on the percentage of the area summing up the vehicle bottom region of each vehicle in the size of the captured image.
[0035] The low luminance pixel extracting unit 14 shown in FIG. 1 extracts low luminance pixels indicating a luminance value below a threshold specified by the luminance threshold specifying unit 13 from each pixel in the input image, and stores the location information. As a storing format of the locations of the low luminance pixels, a binary image in which a low luminance pixel 301 is represented as 1 and the other pixels are represented as 0 may be formed as shown in FIG. 3A . Further, as shown in FIG. 3B , a list format indicated by x, y coordinates may be used for storing.
[0036] The vehicle assumed region extracting unit 15 extracts one or more vehicle assumed regions based on the locations of the extracted low luminance pixels. The extraction process of the vehicle assumed region by the vehicle assumed region extracting unit 15 will be explained with reference to FIG. 4 .
[0037] As shown in FIG. 4 , when a low luminance pixel 401 is extracted by the low luminance pixel extracting unit 14 , the vehicle assumed region extracting unit 15 sets a vehicle assumed region 402 which is assumed to be an image of a peripheral vehicle. More specifically, the vehicle assumed region extracting unit 15 divides the rectangular vehicle assumed region 402 into quarters so as to be arranged in the longitudinal direction (shown with a dotted line) and sets the vehicle assumed region 402 , in which the low luminance pixel 401 is located, within a range region 403 that is the lowest part of the divided vehicle assumed region 402 .
[0038] Here, the height of the range region 403 shown in FIG. 4 shall be a quarter of the height of the vehicle assumed region 402 . However, it is not limited to that. A percentage that the vehicle bottom region accounts for in the heightwise direction in the image of the vehicle may be calculated preliminary, and the height of the range region 403 may set to be a height corresponding to the percentage.
[0039] Further, in the first exemplary embodiment, the vehicle assumed region 402 is set so as to include the low luminance pixel 401 more than a certain number in the range region 403 . However, it is not limited to that. Instead of the configuration in FIG. 4 , the vehicle assumed region 402 may be set so as to include the low luminance pixel in regions 501 which are the both end sides of the range region 403 divided into quarters so as to be arranged in the widthwise direction, as shown in FIG. 5 . Thereby, the setting condition of the vehicle assumed region 402 becomes strict, so the number of pixels of the vehicle assumed region 402 to be set can be limited. Moreover, as a standard relating to the included low luminance pixels, it may be a certain number regardless of the location in the image. For the bottom part of the input image in which the area of the vehicle bottom region tends to become large, the vehicle assumed region may be set in the region which includes more low luminance pixels compared to the region near the center of the input image.
[0040] The vehicle assumed region 402 is set with various sizes and at various locations to satisfy the condition. In this regard, however, in the case where it is known that the road and the vehicle are captured in the image as shown in FIG. 2 , as the captured size of the vehicle relates to the longitudinal location in the image, the size of the vehicle assumed region 402 is to be set corresponding to the location in the image based on the relation. In other words, the more low luminance pixel 401 exists near the bottom of the input image, the larger the vehicle assumed region 402 is to be set, and, the more low luminance pixel 401 exists near the center of the input image, the smaller the vehicle assumed region 402 is to be set.
[0041] The vehicle detecting unit 16 shown in FIG. 1 compares the image of each extracted vehicle assumed region 402 and an actual vehicle image (template), performs pattern matching and determines whether or not the image of the vehicle assumed, region 402 corresponds to a vehicle. As a learning/discrimination apparatus used for pattern matching, a neutral network as recited in Non-patent document 1 may be used, or a support vector machine, a learning vector quantization method, a subspace method and the like may be used. Further, as a feature amount used for a learning/discrimination, a pixel value of a luminance image or a Gabor wavelet feature may be used.
[0042] Next, a case of detecting a vehicle by using the vehicle detection device according to the first exemplary embodiment will be explained.
[0043] First, the image inputting unit 11 inputs an image captured by an on-vehicle camera ( FIG. 6 : step s 61 ) and then outputs the input image to the luminance histogram creating unit 12 . When the luminance histogram creating unit 12 obtains the input image, it creates a luminance histogram of the input image ( FIG. 6 : step s 62 , luminance histogram creating step). The luminance threshold specifying unit 13 specifies a threshold of luminance for extracting pixels corresponding to the vehicle bottom region based on the luminance histogram created by the luminance histogram creating unit 12 ( FIG. 6 : step s 63 , luminance threshold specifying step).
[0044] As to the luminance histogram creating step and the luminance threshold specifying step described above, the contents may be programmed and may be executed by a computer as a luminance histogram creating processing and a luminance threshold specifying processing.
[0045] Subsequently, the low luminance pixel extracting unit 14 measures luminance of each pixel in the input image, extracts low luminance pixels indicating luminance below a threshold and stores the location information thereof ( FIG. 6 : step s 64 , low luminance pixel extracting step). The vehicle assumed region extracting unit 15 sets and extracts a vehicle assumed region in the input image based on the locations of the low luminance pixels extracted by the low luminance pixel extracting unit 14 ( FIG. 6 : step s 65 , vehicle assumed region extracting step). The vehicle assumed region extracting unit 15 sets the vehicle assumed region at the locations of the low luminance pixels corresponding to the tire running surface 203 and the road surface 202 at the bottom side of the vehicle respectively. The vehicle detecting unit 16 performs pattern matching for the image of each vehicle assumed region set by the vehicle assumed region extracting unit 15 and determines whether or not the image of each vehicle assumed region is an image of a peripheral vehicle ( FIG. 6 : step s 66 , vehicle detecting step).
[0046] In the case where a vehicle is detected in a plurality of vehicle assumed regions having overlap, the vehicle detecting unit 16 integrates extraction results so as to employ only a detection result corresponding to a maximum value in similarity ( FIG. 6 : step s 67 ), performs pattern matching for the images of all vehicle assumed regions and ends the processing.
[0047] As to the low luminance pixel extracting step, the vehicle assumed region extracting step and the vehicle detecting step described above, the contents may be programmed and may be executed by a computer as a low luminance pixel extracting processing, a vehicle assumed region extracting processing and a vehicle detecting processing.
[0048] According to the first exemplary embodiment as described above, because of specifying an upper limit for luminance value of pixels assumed to correspond to the image of shadow area at the bottom side of the peripheral vehicle by analyzing a luminance histogram of the input image, it is possible to set a threshold being an upper limit adaptively and to extract a low luminance region which is assumed to be the shadow area at the bottom side of the peripheral vehicle favorably.
Exemplary Embodiment 2
[0049] Next, a vehicle detection device according to a second exemplary embodiment of the invention will be explained.
[0050] FIG. 7 is a block diagram showing a configuration of the vehicle detection device according to the second exemplary embodiment of the invention.
[0051] As shown in FIG. 7 , the second exemplary embodiment includes a road surface region extracting unit 77 in addition to the configuration of the first exemplary embodiment shown in FIG. 1 .
[0052] The road surface region extracting unit 77 extracts a road surface region which is an image region indicating a road surface from an image captured by an on-vehicle camera. As the method for extracting of the road surface region by the road surface region extracting unit 77 , the method for extracting a region sandwiched between right and left white lines as a road region after detecting the white lines by using a white line detection method may be used, as recited in a document (“A White Road Line Recognition System using the Model-Based recognition method”, by The Institute of Electronics, Information and Communication Engineers, Technical Report PRMU99-211). Also, as disclosed in Patent document (Japanese Patent Application Laid-open No. 2001-101420), the method for detecting a road surface directly may be used without detecting a white line.
[0053] A luminance histogram creating unit 72 shown in FIG. 7 creates a luminance histogram indicating a luminance distribution of the road surface region extracted by the road surface region extracting unit 77 . A luminance threshold specifying unit 73 specifies an upper limit (threshold) for luminance value of pixels which is assumed to be a vehicle bottom region, based on the luminance histogram. In other words, comparing to the first exemplary embodiment shown in FIG. 1 , the second exemplary embodiment is different in that the luminance histogram to be analyzed is a brightness distribution of only a road surface region.
[0054] In this way, by limiting a summary range of the luminance histogram to be created to only a road surface region, it becomes possible to speed up the processing to specify a threshold. Further, even if there is a region having a luminance value comparable to the luminance of the vehicle bottom region due to a particular structure of buildings facing a road, when the region is outside of the road surface region, it is possible to specify an upper limit (threshold) for a luminance value of pixels assumed to be the vehicle bottom region without being affected by the region outside.
[0055] A low luminance pixel extracting unit 74 shown in FIG. 7 extracts low luminance pixels indicating luminance below the threshold specified by the luminance threshold specifying unit 73 from each pixel within the road surface region and stores the location.
[0056] A vehicle assumed region extracting unit 75 sets and extracts a vehicle assumed region based on the locations of the low luminance pixels, as well as the first exemplary embodiment shown in FIG. 1 . A vehicle detecting unit 76 determines whether or not the image of the vehicle assumed region is an image of a peripheral vehicle by performing pattern matching, as well as the first exemplary embodiment shown in FIG. 1 .
[0057] Next, the case of detecting a vehicle by using the vehicle detection device according to the second exemplary embodiment of the invention will be explained.
[0058] FIG. 8 is a flowchart showing a processing operation of the vehicle detection device of the second exemplary embodiment.
[0059] First, an image inputting unit 71 inputs an image captured by an on-vehicle camera ( FIG. 8 : step s 81 ). The road surface region extracting unit 77 extracts a road surface region from the input image ( FIG. 8 : step s 82 , road surface region extracting step).
[0060] The luminance histogram creating unit 72 creates a luminance histogram of the road surface region extracted by the road surface region extracting unit 77 ( FIG. 8 : step s 83 , luminance histogram creating step). The luminance threshold specifying unit 73 specifies a threshold of luminance for extracting pixels corresponding to the vehicle bottom region based on the luminance histogram created by the luminance histogram creating unit 72 ( FIG. 8 : step s 84 , luminance threshold specifying step).
[0061] As to the road surface region extracting step, the luminance histogram creating step and the luminance threshold specifying step described above, the contents may be programmed and may be executed by a computer as a road surface region extracting processing, a luminance histogram creating processing and a luminance threshold specifying processing.
[0062] The low luminance pixel extracting unit 74 measures luminance of each pixel within the road surface region extracted by the road surface region extracting unit 77 , extracts low luminance pixels indicating luminance below a threshold and stores the location ( FIG. 8 : step s 85 , low luminance pixel extracting step).
[0063] The vehicle assumed region extracting unit 75 sets a vehicle assumed region at various locations and extracts it based on the locations of the low luminance pixels extracted by the low luminance pixel extracting unit 74 ( FIG. 8 : step s 86 , vehicle assumed region extracting step). The vehicle detecting unit 76 determines whether or not the image of each vehicle assumed region is an image of a peripheral vehicle by performing pattern matching for the image of each vehicle assumed region extracted by the vehicle assumed region extracting unit 75 ( FIG. 8 : step s 87 , vehicle detecting step). The vehicle detecting unit 76 integrates extraction results so as to employ only a detection result corresponding to maximum value in similarity, in the case where a vehicle is detected in a plurality of vehicle assumed regions having overlap ( FIG. 8 : step s 88 ), performs pattern matching for the images of all vehicle assumed regions and ends the processing.
[0064] As to the low luminance pixel extracting step, the vehicle assumed region extracting step and the vehicle detecting step described above, the contents may be programmed and may be executed by a computer as a low luminance pixel extracting processing, a vehicle assumed region extracting processing and a vehicle detecting processing.
[0065] According to the second exemplary embodiment as described above, the vehicle detecting processing is performed for only the image region of the road surface in the captured image. Therefore, a processing time is reduced comparing to the detecting processing for the entire captured image. Further, as an object similar to a vehicle, other than a vehicle, is less likely to be captured in the road surface region, an error detection ratio is reduced.
Exemplary Embodiment 3
[0066] Next, a vehicle detection device according to a third exemplary embodiment of the invention will be explained with reference to FIG. 9 .
[0067] In the exemplary embodiments described above, the vehicle assumed region extracting unit decides the vehicle assumed region based on the information from the low luminance pixel extracting unit. However, it is not limited to that. The vehicle assumed region extracting unit may extract a partial region, which has a possibility of corresponding to a peripheral vehicle, from the captured image as the vehicle assumed region and may perform the verification in another step. This example will be explained as the third exemplary embodiment.
[0068] As shown in FIG. 9 , the third exemplary embodiment includes: an image inputting unit 91 for inputting an image captured by an on-vehicle camera; a luminance histogram creating unit 93 for creating a luminance histogram of the input image; a luminance threshold specifying unit 94 for specifying an upper limit (threshold) for luminance value of pixels assumed to be a vehicle bottom region by analyzing the luminance histogram; and a vehicle detecting unit 95 for deciding the vehicle assumed regions ( 202 and 203 ) including the vehicle bottom region having the luminance value not greater than the upper limit and for determining whether or not the image of the vehicle assumed region corresponds to a vehicle by using a pattern matching method.
[0069] The vehicle detecting unit 95 includes a low luminance pixel extracting unit 96 , a vehicle assumed region extracting unit 92 and a verifying unit 97 . Note that the low luminance pixel extracting unit 96 has the same configuration as the low luminance pixel extracting unit 14 shown in FIG. 1 .
[0070] The vehicle assumed region extracting unit 92 extracts a partial region, which has a possibility of corresponding to a peripheral vehicle, from the image captured by an on-vehicle camera as the vehicle assumed region. More specifically, the vehicle assumed region extracting unit 92 may extract the partial region determined as a vehicle image by performing pattern matching for the entire input image, or may calculate distance information from a stereo image which is obtained by using an on-vehicle stereo camera as a capturing unit and then may extract a region that the shape of the distance information is similar to a vehicle. Further, the vehicle assumed region extracting unit 92 may make location information obtained by using a millimeter wave sensor or a laser radar sensor correspond to the location in the captured image, may detect the location where an obstacle exists by the millimeter wave sensor or the laser radar sensor, and then may extract a partial region corresponding to the location in the input image.
[0071] The luminance threshold specifying unit 94 shown in FIG. 9 analyzes a luminance histogram of the input image and calculates an upper limit (threshold) for luminance value of pixels assumed to be a vehicle bottom region, as well as the first exemplary embodiment shown in FIG. 1 .
[0072] The verifying unit 97 measures whether or not low luminance pixels indicating a luminance value below a threshold is included more than predetermined pixels at the bottom of the vehicle assumed region extracted by the vehicle assumed region extracting unit 92 , and if included, determines the vehicle assumed region is an image of a peripheral vehicle. Thereby, whether or not the vehicle assumed region is an image of a peripheral vehicle is determined finally.
[0073] Next, the case of detecting a vehicle by using the vehicle detection device according to the third exemplary embodiment of the invention will be explained.
[0074] FIG. 10 is a flowchart showing a processing operation of the vehicle detection device of the third exemplary embodiment.
[0075] First, the image inputting unit 91 input an image captured by an on-vehicle camera ( FIG. 10 : step s 101 ). The vehicle assumed region extracting unit 92 extracts a partial region which has a possibility of a peripheral vehicle image as a vehicle assumed region ( FIG. 10 : step s 102 , vehicle assumed region extracting step).
[0076] The luminance histogram creating unit 93 creates a luminance histogram of the input image as well as the first exemplary embodiment shown in FIG. 1 ( FIG. 10 : step s 103 , luminance histogram creating step). The luminance threshold specifying unit 94 analyzes the luminance histogram created by the luminance histogram creating unit 93 and specifies an upper limit (threshold) for luminance value of pixels corresponding to a vehicle bottom region ( FIG. 10 : step s 104 , luminance threshold specifying step)
[0077] The verifying unit 97 measures whether or not low luminance pixels indicating luminance below a threshold are included more than predetermined pixels at the bottom of the vehicle assumed region extracted by the vehicle assumed region extracting unit 92 based on the output data from the vehicle assumed region extracting unit 92 and the low luminance pixel extracting unit 96 , and outputs the final determination result whether or riot the image of the vehicle assumed region is an image of a peripheral vehicle.
[0078] The vehicle detecting unit 95 determines whether or not the image of the vehicle assumed region verified by the verifying unit 97 corresponds to a vehicle by using a pattern matching method, based on the data output from the verifying unit 97 ( FIG. 10 : step s 105 , vehicle detecting step) and measures the presence or absence of low luminance pixels for all vehicle assumed regions and then ends the processing.
[0079] As to the vehicle assumed region extracting step, the luminance histogram creating step, the luminance threshold specifying step and the vehicle detecting step described above, the contents may be programmed and executed by a computer as a vehicle assumed region extracting processing, a luminance histogram creating processing, a luminance threshold specifying processing and a vehicle detecting processing.
[0080] According to the third exemplary embodiment described above, even if the vehicle assumed region extracting unit 92 extracts an image region having a shape similar to a vehicle, for example, images of a container-like object on the road, a square window frame or the like, as a vehicle assumed region by error, the bottoms of these objects does not have structure to which a direct right of sun and an indirect light from peripheral objects are not incident, and low luminance pixels are not included in the detected image. Therefore, by measuring that the low luminance pixels are not included in the detected image, it is possible to determine that the vehicle assumed region is detected by error.
[0081] As above, the present invention has been explained with reference to the exemplary embodiments (and examples) However, the present invention is not limited to the exemplary embodiments (and examples) described above. The configurations and details of the present invention can be made various modifications that one skilled in the art is able to understand within the scope of the present invention.
[0082] This application claims priority from Japanese Patent Application No. 2006-223597 filed Aug. 18, 2006, which is incorporated herein in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0083] FIG. 1 is a block diagram showing the configuration of a vehicle detection device according to a first exemplary embodiment of the invention.
[0084] FIG. 2 is a diagram showing an example of an image captured by an on-vehicle camera of the exemplary embodiment shown in FIG. 1 .
[0085] FIG. 3 is a diagram showing a storing format of the location of a low luminance pixel extracted in the exemplary embodiment shown in FIG. 1 .
[0086] FIG. 4 is a diagram showing an example of a vehicle assumed region set in the exemplary embodiment shown in FIG. 1 .
[0087] FIG. 5 is a diagram showing another example of the vehicle assumed region set in the exemplary embodiment shown in FIG. 1 .
[0088] FIG. 6 is a flowchart showing an operation of the vehicle detection device of the exemplary embodiment shown in FIG. 1 .
[0089] FIG. 7 is a block diagram showing the configuration of a vehicle detection device according to a second exemplary embodiment of the invention.
[0090] FIG. 8 is a flowchart showing an operation of the vehicle detection device of the exemplary embodiment shown in FIG. 7 .
[0091] FIG. 9 is a block diagram showing the configuration of a vehicle detection device according to a third exemplary embodiment of the invention.
[0092] FIG. 10 is a flowchart showing an operation of the vehicle detection device of the exemplary embodiment shown in FIG. 9 .
[0093] FIG. 11 is a diagram showing an example of an image captured by a common on-vehicle camera.
DESCRIPTION OF SYMBOLS
[0000]
11 , 71 , 91 image inputting unit
12 , 72 , 93 luminance histogram creating unit
13 , 73 , 94 luminance threshold specifying unit
14 , 74 low luminance pixel extracting unit
15 , 75 vehicle assumed region extracting unit
16 , 76 vehicle detecting unit
77 road surface region extracting unit
92 vehicle assumed region extracting unit
95 vehicle detecting unit | Attention is paid on the phenomenon that substantially no direct sun light or no reflected light from surrounding objects is applied, to a vehicle bottom side and tire travel surfaces and the vehicle bottom side and the tire travel surfaces have lower luminance values than all the other portions including the shades of trees or buildings along the road in an on-vehicle camera image. Luminance threshold specifying unit ( 13 ) analyzes an image luminance histogram and specifies the upper limit of the pixel luminance which can be assumed as a region of the vehicle bottom side. Vehicle assumed region extracting unit ( 15 ) assumes that the pixel position having a luminance value not greater than the upper limit is the region of the vehicle bottom side and sets a vehicle assumed region, thereby verifying presence/absence of a vehicle in the vicinity. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to color picture tubes, and more particularly a color picture tube of an in-line dot type intended for fine and high-quality display of characters with an improved purity and completeness of the picture image over the whole screen.
In the color picture tube of in-line dot type used, for example, as a video data terminal unit, as well known in the art, a fluorescent screen consisting of a plurality of phosphor dots is formed on the inner surface of a panel of a glass bulb serving as a vacuum envelope. A dot type shadow mask having circular apertures which are arrayed horizontally and vertically is spaced apart from the fluorescent screen by a predetermined distance. Mounted in the envelope is an in-line type three-electron-gun structure which opposes the shadow mask. Beams of electron emitted from the electron gun structure pass through apertures of the shadow mask and impinge upon the fluorescent screen to establish trios of electron beams.
With the in-line dot type color picture tube, when the electron beam is scanned in horizontal and vertical directions, three electron beams pass through one of the apertures in the shadow mask to form a trio of electron beams on the fluorescent screen. The arrangement of such a trio of electron beams is distorted at points on each scanning line as indicated in FIG. 1 due to the surface geometry of the panel and the deflecting magnetic field characteristics of the deflection yoke. As a result, a line connecting the beam trio is inclined by an inclination angle φ in respect of the horizontal line. This tendency is aggravated at four corners of the screen.
In a conventional shadow mask, however, apertures at the central portion and apertures at the corner are aligned horizontally and this horizontal arrangement is straightforward. When trios of electron beams are established at the corners through such a shadow mask, the interdistance between adjacent electron beams on the fluorescent screen becomes irregular as shown in FIG. 2 with the result that tolerance for color purity is degraded. More particularly, when taking trios of electron beams 20b 1 , 20g 1 and 20r 1 ; 20b 2 , 20g 2 and 20r 2 ; 20b 3 , 20g 3 and 20r 3 ; and 20b 4 , 20g 4 and 20r 4 for example, beams 20g 1 , 20r 1 and 20b 3 are spaced from each other at an equi-distance, thereby forming an approximate equilateral triangle and do not degrade the purity tolerance. However, the interdistance between adjacent beams 20r 1 and 20b 2 is extended whereas the interdistance between adjacent beams 20b 2 and 20g 3 is narrowed. Consequently, the interdistance between some of adjacent electron beams becomes irregular and the purity tolerance becomes considerably degraded as compared to one that will fully be capable of utilizing the dimensions of the trio of dots on the fluorescent screen and electron beams. The limitations on the purity tolerance cannot be eliminated whatever design correction lens is used when forming the phosphor dots.
Thus, it was the practice in the conventional art to place an inner shield inside the bulb to cure the effect of the earth magnetism, or to decrease the aperture diameter through the shadow mask. Alternatively, the difference in grading for the shadow mask is increased as compared with that of a shadow mask for the other types, i.e., electron gun and stripe shadow mask type and delta electron gun and dot shadow mask type.
However, if the difference in grading is increased, the completeness of the picture image throughout the screen becomes impaired, and hence, the quality of the picture image becomes degraded, thus imposing disadvantages on the graphic display. Decreased aperture diameter at the central portion for the overall completeness of the picture image will decrease utilization efficiency of the electron beams. On the other hand, the otherwise unnecessary excessive current flow will be needed in order to obtain the predetermined brightness, which deteriorates the focusing, damages the high resolution required of the high definition tube and increases the burden on the cathode electrode, thus shortening lifetime.
SUMMARY OF THE INVENTION
The present invention contemplates elimination of the prior art drawbacks and has for its object to provide a color picture tube which can improve purity characteristics throughout the picture screen.
Another object of the present invention is to provide a color picture tube having high utilization efficiency of the electron beams.
According to the present invention, in a color picture tube comprising a fluorescent screen formed on the inner surface of the panel and consisting of a plurality of trios of phosphor dots, a dot type shadow mask having circular apertures which are arrayed horizontally and vertically and spaced from the fluorescent screen by a predetermined distance, and an in-line type three-electron-gun structure for emitting beams of electron which pass through apertures of the shadow mask and impinge upon the fluorescent screen to establish trios of electron beams, the horizontal arrangement of the apertures of the shadow mask is such that the interdistance between adjacent electron beams on the fluorescent screen based on beams of electrons passing through apertures at the corners of the shadow mask is made substantially equal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an arrangement of trios of electron beam distorted at the time of beam deflection;
FIG. 2 is a diagram useful in explaining the irregular interdistance between adjacent electron beams at the corner of a prior art shadow mask;
FIG. 3 is a plan view of an essential portion of one example of a shadow mask according to the present invention;
FIG. 4 shows an arrangement of electron beams obtained by using a shadow mask of the present invention;
FIG. 5 shows the correlation between the tangent of the inclination relative to the horizontal line formed by the beam trio arrangement and the coordinates x and y when x is fixed;
FIG. 6 is a similar graph in which y is fixed;
FIG. 7 shows the horizontal arrangement of shadow mask apertures according to the teachings of FIG. 3;
FIG. 8 shows the arrangement of circular apertures at the corner of a shadow mask where vertical pitch is determined independent of the horizontal pitch;
FIG. 9 shows the arrangement of phosphor dots corresponding to the mask shown in FIG. 8; and
FIG. 10 shows a corner part of a shadow mask of another embodiment according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 3, a shadow mask 30 for use in a color picture tube (not shown) which embodies the present invention is constructed by aligning apertures 31 in the direction of B in which electron beams 20b, 20g and 20r on each scanning line are aligned depending on the geometry of the panel at the corner (right-lower corner) of the screen. More particularly, the horizontal (U-direction) arrangement of the apertures 31 is inclined with respect to horizontal axis X of the shadow mask 30 by an electron beam arrangement distortion angle φ as shown in FIG. 1 where φ is a variable function of position as given in FIGS. 5 and 6.
In this case, the arrangement of electron beams on each scanning line may be made geometrically ideal in respect of the purity properties as shown in FIG. 4 if the arrangement of the apertures of the shadow mask 30 is suitably designed. By using a suitable correction lens such as a continuous correction lens or multi-lens for exposure, the optimum arrangement of trios of phosphor dots may be aligned with the direction B of the electron beam arrangement, thus providing a greater purity tolerance than in the prior art.
The angle φ between the horizontal axis x and the beam trio arrangement direction B will be detailed herein. FIG. 5 shows by a broken line the relation between vertical position y of the beam trio arrangement and tan φ on a vertical line as defined by fixing horizontal position x at x=-132 mm when the origin of Cartesian coordinates coincides with the center of the picture screen. FIG. 6 similarly shows the relation between horizontal position x and tan φ on a horizontal line of y=99 mm. The broken line curves in these figures are obtained by plotting values measured in respect of 13 V 90° deflection type tube. The above relations can be approximated by a linear equation, ##EQU1## which is illustrated at solid lines in the figure. In this approximation,
A=-4.6×10.sup.-6
is obtained for the color picture tube of the type mentioned above.
If the arrangement of apertures in the shadow mask is forced to line along the horizontal line by neglecting such a distortion, the tolerance in color purity is drastically reduced, brightness becomes different at the center and the corner of the screen, and the quality of picture is deteriorated, as described above. Accordingly, inclining the horizontal arrangement of apertures 31 by the angle φ in accordance with the present invention as mentioned above is aligning the horizontal arrangement of the shadow mask apertures with the arrangement of trios of deflected beams which has an inclination relative to the horizontal axis growing toward the corners of the screen. Therefore, coordinates (x, y) of the phosphor dots correspond to those of the shadow mask apertures according to the present invention.
In general, alignment curves may be obtained from differential equation (2), ##EQU2## where m is an integer and Pv represents the vertical pitch between apertures of the shadow mask at (0, 0). But, since errors are negligible even with f (x, y)=Axy as indicated in FIGS. 5 and 6, the approximation pursuant to equation (1) is maintained. Then, by solving equation (2), the aperture arrangement curve expressed by equation (3) is obtained. ##EQU3## where ε is the base for natural logarithms.
Accordingly, by determining the horizontal arrangement of apertures of the shadow mask, it is possible to make uniform the interdistance between adjacent electron beams on the fluorescent screen based on beams of electrons which pass through apertures at the shadow mask corners upon deflection of electron beam.
Incidentally, as is clear from equation (3), when the horizontal arrangement of apertures of the shadow mask is aligned with the direction of the beams arranged at the time of beam deflection, y becomes smaller at positions near the horizontal edge than at the center, naturally making the aperture vertical pitch near the edge shorter than at the central portion.
A color picture tube comprising an in-line type three-electron gun structure and a dot type shadow mask (unlike the usual vertical stripe type) can be utilized for character display in a video data terminal unit and the number of scanning lines may be increased as desired in order to improve the resolution. When the number of horizontal scanning lines is increased, the vertical pitch between apertures must be decreased so as to prevent moire pattern arising from interference. When three electron guns are arranged in in-line, freedom to allowance for the vertical pitch variation is large unlike the delta type arrangement; however, there exists such a limitation that the horizontal pitch should be √3 times as large as the vertical pitch if regularly circular phosphor dots of R, G, and B are arranged in a regular triangle configuration or with the greatest density to obtain high utilization efficiency of the electron beam.
However, if the horizontal pitch is reduced to agree with the above condition in compliance with the decrease in the vertical pitch, so-called q size or the distance between the shadow mask and the fluorescent screen on the inner surface of the panel and the curvature of the mask should be altered in order to achieve the optimum condition for beam landing. This will require a new die for shaping a curved surface of the shadow mask. Thus, many difficulties are encountered in increasing the number of horizontal scanning lines and reducing the vertical pitch in the aperture arragement.
Considering the fact that the production of this type of color picture tubes is smaller than that of the color TV picture tubes, it is practical to set the vertical pitch in the aperture arrangement independently of the horizontal pitch so as not to require changes in the horizontal pitch, since the die for the curved mask surface and the correction lens may be used without any modification. The arrangement of the apertures in a shadow mask in this case may be expressed by equation (4); ##EQU4## where n is an integer, (m+n) should be an even number and P H is the horizontal pitch at the center of the shadow mask.
However, if the arrangement of circular apertures as in the FIG. 3 embodiment is applied to a shadow mask in accordance with equation (4), the apertures are arranged at the corner as shown in FIG. 8 while the arrangement of the phosphor dots corresponding thereto becomes as shown in FIG. 9. Distances a and b in FIG. 9 are different and accordingly, the tolerance for color purity varies in different directions and the high density arrangement of phosphor dots cannot be realized. Therefore, the diameter of an aperture of regular circle has to be designed to meet the shortest distance b. Consequently, the phosphor dot arrangement cannot be of high density, failing to make full use of the purity tolerance.
In another embodiment of the present invention, therefore, for the purpose of improving the beam utilization efficiency by making highly dense the phosphor dot arrangement, the vertical aperture pitch is made independent of the horizontal aperture pitch and in addition thereto, the shape of the aperture is specified. More particularly, the circular aperture is gradually changed into an ellipse aperture as the arrangement of phosphor dots deviates from the desired condition of the closest density. The longer diameter L of the ellipse apertures is aligned with the direction of the beam trio arrangement at the time of beam deflection and the ratio of the shorter diameter S to the longer diameter L is reduced corresponding to the horizontal deviation X=nP H from the center of the mask as expressed in equation (5). ##EQU5##
FIG. 10 shows the arrangement of apertures near the four corners of the shadow mask in accordance with this embodiment.
In general, assuming that peripheral apertures have a diameter ratio as expressed by η(x, y) in comparison with the center aperture and that the diameter of the center aperture is D, the function defined by equation (6) is obtained.
√SL=η(x, y)D (6)
Then, by providing an ellipse aperture having the longer diameter L and the shorter diameter S which satisfy equations (4), (5) and (6), it is possible to easily produce a shadow mask having a desired beam transmission distribution and an excellent beam utilization efficiency from an existing die for curved surface of the shadow mask and correction lens.
As described above, this embodiment ensures easy design and production of a shadow mask by using a conventional shadow mask shaper die, the shadow mask of this embodiment being free from moire interference and capable of realizing the desired beam utilization with the closest density when used in a shadow mask type display color picture which is different from the usual color picture tube in the number of horizontal scanning lines. This embodiment further achieves such an effect as to freely control grading all over the screen. | In a color picture tube especially incorporating an in-line dot type shadow mask, the horizontal arrangement of the apertures of the shadow mask is determined to make substantially equal the interdistance between adjacent electron beams formed on the fluorescent screen based on beams of electron passing through apertures at the corners of the shadow mask, thereby making full use of the purity tolerance. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a method of predetermining the gloss of a polyvinyl chloride (PVC) compound. In particular, it relates to preparing samples of a PVC compound having different molecular weight (MW) distributions, making articles from the samples, measuring the gloss of the articles, determining the relationship between the MW distribution and the gloss, and selecting a MW distribution from that relationship that will give the desired gloss.
PVC articles are made by molding PVC powders and plastisols. To enhance the appearance of the articles, manufacturers want to be able to control their gloss, so that their surfaces are as shiny or dull as desired. Gloss can be controlled by mixing PVC powders of different particle size distributions and by incorporating specialty resins or gloss control additives into the resin. These methods increase the cost of the materials needed to make the article and the number and complexity of the steps in the manufacturing process.
SUMMARY OF THE INVENTION
We have discovered that the gloss of articles made from mixtures of two PVC resins of different MWs falls to a minimum then increases again as the ratio of the resins in the mixture changes from 100% of one resin to 100% of the other resin. Remarkably, the minimum gloss is less than the gloss of articles prepared from 100% of either of those two resins. These results are surprising because it was expected that the gloss of articles made from such mixtures would be linearly proportional to the amount of each resin in the mixture (with the end points being the gloss of 100% of either resin). Because of this discovery, it is now possible to achieve a predetermined amount of gloss without using different particle size distributions, specialty resins, or gloss control additives.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph giving the results of Example 1, where the ordinate is 60 degrees gloss and the abscissa is the ratio of the higher MW resin to the lower MW resin.
FIG. 2 is a graph giving the results of Example 2, where the ordinate is 60 degrees gloss and the abscissa is the ratio of the higher MW resin to the lower MW resin.
FIG. 3 is a graph giving the results of Example 3, where the ordinate is gloss and the abscissa is the ratio of the higher MW resin to the lower MW resin.
FIG. 4 is a graph giving the results of Example 4, where the ordinate is gloss and the abscissa is the ratio of the higher MW latex to the lower MW latex.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention is applicable to any PVC compound. The PVC resin used in the PVC compound can be a homopolymer or a copolymer containing up to 15 wt % of another monomer, such as a vinylacetate, maleate, or acrylate. The resin, a powder, can have a particle size from about 0.1 to about 200 microns; a preferred particle size is about 0.2 to about 2 microns. The resin is used to make PVC compounds, such as plastisols, organosols, or aquasols, by the inclusion of various additives such as plasticizers, diluents, thermal stabilizers, pigments, fillers, and specialty surfactants. Examples of plasticizers that can be used include phthalates, dibenzoates, polymerics, and trimellitates.
An article made from a PVC compound that has a predetermined amount of gloss on its surface can be made according to a method of this invention. First, it is necessary to determine the relationship between the MW distributions of the resins one wishes to use and the amount of gloss on a surface of an article made from compounds containing those resins. This can be done by preparing at least two samples of compounds made from resins having different MW distributions. About 2 to about 5 samples are preferred, but more samples may be needed under particular circumstances. The samples can be prepared by mixing various ratios of two resins that have different MWs, where the two resins are otherwise chemically the same or chemically different (i.e., the surfactants in the resins are different or a different amount of an surfactant is used). Samples can also be prepared by blending latices of different MWs to make a single dispersion resin.
The greater is the difference between the MWs of the two resins (i.e., the wider the MW distribution of the mixture of the two resins), the greater will be the maximum decrease in the gloss of the article. To express this another way, if two resins of different MWs are mixed, the resulting MW distribution will be bimodal (or unimodal with a higher dispersity) and the gloss of the article will decrease as the distance between the peaks of the two modes increases (or as the polydispersity increases). For example, compared to the minimum gloss of either resin in the mixture, a difference in the peak MWs of two resins of only about 5 K (where “K” means the K value, which is a measure of MW) may decrease the gloss of the article 10 gloss units at the minimum gloss, but a difference in peak MWs of about 20 K may decrease the gloss of the article 40 gloss units at the minimum gloss. Best results are achieved if the two resins differ in MW by at least about 5 K and preferably at least about 12 K.
While samples made by mixing two resins of different MWs in increasing 15 ratios of one resin to the other resin will not have two peaks at various distances apart, the size of the two peaks will change from a high peak and a low peak to equal peaks to a low peak and a high peak, which means that the standard deviation of the MW distribution will increase to a maximum, then decrease again. (With most commercial PVC resins, the standard deviation will increase, but two distinct peaks will not be discernable.) Since the maximum decrease in gloss is usually at a weight ratio of higher MW resin to lower MW resin between about 1 and about 20, samples can advantageously be prepared that include at least one ratio within that range.
Articles are then made from the samples, by casting a film or by a molding process such as die molding or cavity molding. The gloss on a surface of the articles is measured, for example, by using a gloss meter. The resulting data can be arranged on a graph using Cartesian coordinates with the ratio of the two resins in the mixture gradually increasing on one coordinate and the gloss at a ratio tested given on the other coordinate. The data points can be joined, for example, by hand or by mathematically fitting a curve to them, to give the relationship between MW distribution and gloss. The gloss is inversely related to the width of the MW distribution. That is, the gloss decreases as the standard deviation of the MW distribution increases, except that the maximum decrease in gloss may not coincide with the maximum standard deviation of the MW distribution. As illustrated by the drawings, the relationship is a U-shaped curve where the gloss decreases as the ratio of the lower MW resin to the higher MW resin increases, then increases again after reaching a minimum at a particular ratio. The curve can be approximately fitted to the equation c(x−R) 2 =y−m, where x is the ratio of the higher MW resin to the lower MW resin, y is the gloss, R is the ratio of the higher MW resin to the lower MW resin at the minimum gloss, m is the minimum gloss, and c is a constant. Once this relationship is determined, one can select the amount of gloss desired, then, from the curve, find the (usually) two ratios of the two resins that give that amount of gloss, and use one of those ratios to make articles having the desired amount of gloss.
Since the MW distribution of the resin may affect properties of the compound in addition to its gloss, it may be desirable to alter the MW distribution no more than is necessary to achieve the desired amount of gloss. This can be accomplished by reducing the difference between the MWs of the two resins (i.e., reducing the standard deviation of the MW distribution) until the desired gloss is the minimum gloss.
The following examples further illustrate this invention. The resins used in the examples are made and sold commercially by Occidental Chemical Corporation. The following table gives the MW of the resins:
Resin
MW(K)
“Oxy 80HC”
80
“Oxy 75HC”
75
“Oxy 68HC”
68
“Oxy 605”
62
“Oxy 625”
67
EXAMPLE 1
Six PVC compounds were prepared by mixing various ratios of two PVC resins, “Oxy 80HC” and “Oxy 68HC,” which are chemically-identical but have different MWs. The formulations used were 100 parts by weight (pbw) resin in the ratios given in FIG. 1, 50 pbw phthalate plasticizer, 5 pbw aliphatic diluent, and 3 pbw thermal stabilizer. Films were cast and fused on a glass plate at 200° C. The gloss of the films was determined using a Byk Gardener micro Trigloss meter. FIG. 1 gives the results and shows that the minimum gloss occurred at a ratio of the higher to the lower MW resin of about 75/25.
EXAMPLE 2
Example 1 was repeated using two chemically-identical PVC resins with less difference in MW, “Oxy 80HC” and “Oxy 75HC.” FIG. 2 gives the results and shows that the gloss is reduced by 5 points at a 90:10 ratio of “Oxy 80HC” to “Oxy 75HC.” Comparing FIGS. 1 and 2 shows that the decrease in gloss was greater when the difference between the MWs of the two resins was greater.
EXAMPLE 3
Example 1 was repeated using two chemically-different PVC resins, except that 20 pbw of “Oxy 567,” a blending resin, was used in the compounds. In Curve A the dispersion resins were “Oxy 80HC” and “Oxy 605”; in Curve B the dispersion resins were “Oxy 75HC” and “Oxy 605”; in Curve C the dispersion resins were “Oxy 75HC” and “Oxy 68HC”; and in Curve D the resins were “Oxy 80HC” and “Oxy 68HC.” Films were cast and fused on a black/white Leneta Card at 200° C. FIG. 3 gives the results and shows that a minimum gloss occurred as before.
EXAMPLE 4
Example 3 was repeated using single dispersion PVC resins made by blending latices of different K values,.except that 20 pbw of “Oxy 567” was used in these compounds. FIG. 4 gives the results. In Curve A, the resins were “Oxy 80HC” and “Oxy 625” and in Curve B, the dispersion resins were “Oxy 80HC” and “Oxy 605.” FIG. 4 shows that producing a single dispersion resin having a wide MW distribution has the same effect as blending dry resins having different MWs. FIG. 4 also shows that the greatest reduction in gloss occurs when the difference between the MWs of the resins used is the greatest. | A method of making an article from polyvinyl chloride compound that has a predetermined amount of gloss is disclosed. Samples of the resin are prepared that have different molecular weight distributions. Articles are made from the samples and the gloss of the articles is measured. The relationship between the molecular weight distributions of the samples and the gloss of the articles made therefrom is determined. From that relationship, an article is made from a resin selected such that its molecular weight distribution corresponds to the predetermined amount of gloss. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to electronic circuits designed to exercise a control function by turning on small motors, heaters, water valves, etc. related to car washing machinery, laundry machinery, fluid dispensers or any other unattended equipment which can be controlled by deposit of coins for sale of a service of predetermined duration.
2. Description of the Prior Art
In the past and to a great extent at present, appliance controls requiring timed on-off cycles incorporate composite electromechanical switches consisting usually of a time-delay secondary relay controlling a primary contactor which accomplishes the power switching function. Design of the secondary relay depends on time interval considerations. Orificed pneumatic or hydraulic dash-pot arrangements are used for delays of 30 seconds to several minutes while switch contactors driven by synchronous clock motors can be used for "on" or "off" cycles of 30 seconds to weeks or even months. Bimetallic thermal switches with fixed or variable time intervals based on thermal inertia have also been successfully used for secondary controls.
As highly reliable and comparatively low-priced semiconductor products became available, it became practical to construct all electronic counterparts of many types of electromechanical controllers. Such electronic counterparts are in most cases cheaper and more reliable. These solid state controls also show promise of long, maintenance-free lifetimes and high resistance to degrading environmental factors such as temperature, humidity and exposure to dirt and grease. These features are important considerations with regard to controls for laundry and related machinery or other equipment operating under similar environmental conditions.
Accordingly, a need is perceived to exist for an electronic circuit which can be incorporated into a hermetically sealed container with a 550 watt "on" cycle subject to a nearly unlimited choice of time intervals and with the "on" cycle initiated by momentary closure of an external circuit with less than 10 volts of lead-to-lead potential and with less than one-half milliampere of current at the moment of circuit closure. It is believed that an electronic switching module with these characteristics will have a variety of industrial control applications.
SUMMARY OF THE INVENTION
Accordingly, a general object of this invention is to provide a novel and reliable electronic switching circuit for turning on a 550 watt, 115 volt AC resistive or inductive load for a predetermined time period after which power to the load is turned off without further action by the operator or user.
A specific object of the invention is to provide a switching circuit which can be hermetically encapsulated in a conveniently sized module.
Another object of the invention is to provide a switching module with six color-coded flexible leads to facilitate permanent connection of the module to the AC supply with correct polarity and to simplify connections to the load and control lines.
Other objects and further features of the invention will be apparent from the following detailed description of the preferred embodiments of the invention when read in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of the inventive switching circuit; FIG. 2 is a detailed schematic diagram showing interconnections between and value of components used in the switching circuit; and
FIG. 3 is a perspective view of the encapsulated module containing the switching circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The block diagram shown in FIG. 1 illustrates the basic functions of the switching circuit. The D.C. power supply 10 is derived from the AC input by means of a one-half wave rectifier circuit and dropping resistors. Part of the supply feeding an integrated circuit in control logic 12 and timing capacitor 14 is regulated to ten volts by a zener diode. The time control logic circuit 12 consists of a Quad two input Schmitt trigger NAND gate. Only three of the four gates in the IC are used. Two gates are connected to function as an R-S flip-flop. One gate is used to reset the flip-flop upon completion of an "on" cycle.
A COS/MOS NAND gate IC is used for this application because of its negligible quiescent current and because the regenerative character of the Schmitt trigger makes the set and reset switching modes stable and reliable. The timing capacitor 14 is a commercial grade 220 ufd. aluminum electrolytic capacitor. When used in conjunction with an adjustable resistor, capacitor 14 is large enough to provide an "on time" of up to 15 minutes. The dual triac switch 16 consists of a combination of a small current triac which turns on a 5 amp load control triac and keeps the power triac on until the time delay logic 12 signals that the "on" cycle is completed.
A detailed schematic diagram of the switching circuit is shown in FIG. 2. Terminals for connection of the switching circuit to an AC source, a load and the control line are shown at 20 and 22, 26 and 24 respectively. A black lead is connected to terminal 20 which in turn is connected to the high or hot side of the 115 volt supply. A white lead connected to 22 is for connection to the neutral or low side of the AC supply source. The black supply connection must always be connected to the high side of the AC line. If the switching circuit is used in conjunction with a plug-in AC source, the plug should be polarized to prevent reverse connection of the AC line. The two terminals at 24 are for connection to a pair of green leads which are the "on" control lines. Momentary closure of the green leads turns the switching circuit on. The two terminals at 26 are connected to two red leads which serve the switched AC load.
The AC rail which extends from terminal 20 to one of the terminals at 26 is linked to the D.C. loads through, for example, a 1N4005 power diode CR1 and resistor R1 which is a 620 ohm 1/2 watt resistor supplying the unregulated D.C. voltage connected to the collector of transistor Q2 and the gate of driver triac Q3 through 18 k-ohm 1 watt, resistor R9. The unregulated D.C. supply is filtered by 1 ufd capacitor C1. C1 is a 150 volt elctrolytic capacitor connected from D.C. plus to the ground rail and is also connected to the AC neutral at 22. The unregulated D.C. supply is connected to the regulated supply through 27 k-ohm regulator resistor R2. Voltage regulation is provided by CR2 which may be a 10 volt 1N5240A zener diode or alternatively a 1N758A zener diode connected between the regulated D.C. plus rail and ground.
The D.C. 10 volt supply is connected to integrated circuit IC-1 at pin 14(V DD ). Circuit IC-1 is, for example, an RCA COS/MOS dual input quad NAND gate-type CD4093. The 10 volt supply is also connected to pin 8 of IC-1 through R4, a 33 k-ohm 1/4 watt resistor which is shunted by a 0.01/uf 50 volt capacitor C3. Pin 8 is also connected to one terminal of the control circuit pair 24. The other terminal of the control circuit 24 is connected to the ground rail 22. Unused gate inputs at pins 12 and 13 of IC-1 are also connected to the regulated D.C. supply. Pin 11 of IC-1 is allowed to float. Pin 5 of IC-1 is connected to pin 6 which is also connected to the junction of 22 ohm resistor R7, 500 k-ohm adjustable resistor R13 and the positive terminal of a 220 ufd capacitor C2. Pin 1 of IC-1 is connected to pin 4 through a 33 k-ohm 1/4 watt resistor. Pin 1 of IC-1 is also connected to the ground rail through R3 which is a 330 k-ohm 1/4 watt resistor shunted by a 0.01 ufd 50 volt capacitor C4. Pin 2 of IC-1 is connected to pin 10. Pin 3 of IC-1 is connected to pin 9. Pin 9 is also connected to the base of transistor Q1 through R6 which is a 68 k-ohm 1/4 watt resistor and to the base of transistor Q2 through R10 which is a 68 k-ohm resistor.
Transistors Q1 and Q2 are NPN-type such as a 2N5088, or alternatively a MPSA05. The regulated 10 volt supply is connected to the positive terminal of C2 through R8 and R13. The negative terminal of C2 is connected to the ground rail. Resistor R13 is a 500 k-ohm adjustable resistor and R8 is a 560 k-ohm 1/4 watt resistor. Capacitor C2 is a 220 ufd 10 volt electrolytic capacitor which serves as the storage capacitor to control the "on time" of the switching circuit. The positive terminal of C2 is connected to the collector of Q1 through a 22 ohm 1/4 watt resistor R7.
As previously stated, the positive terminal of C2 is also connected to pin 5 and pin 6 of IC-1. The emitter of Q1 and the emitter of Q2 are both connected to the ground rail 22. Terminal MT1 of driver or pilot triac Q3 is connected to the ground rail through a 1000 ohm 1/4 watt resistor R12. MT1 of driver triac Q3 is also connected to the gate of output triac Q4. Terminal MT1 of the output triac is connected to the ground rail. MT2 of the output triac is connected to the low side of the pair of controlled output terminals 26. MT2 of the output triac Q4 is also connected to MT2 of the driver triac Q3 through a 100 ohm 1/4 watt resistor R11. Driver triac Q3 is, for example, a type L200E3 by TECCOR and output triac Q4 is, for example, a type Q2015L5 also by TECCOR.
The output triac Q4 is housed in a plastic flat pack counterpart of the TO66. The triac pellet is electrically insulated but thermally coupled to the metal heat radiator support element. For this reason, the output triac Q4 is mounted on the underside of the printed circuit board, so the metal heat radiator is flush with the bottom of the encapsulated switching circuit. When the switching module is bolted in place, any metal mounting surface serves as a heat sink. Resistors used in the switching circuit assembly have a tolerance of 5%.
The potting cup used to house the switching circuit printed circuit board is shown in FIG. 3. A high quality, non-hygroscopic, high dielectric two-part epoxy potting compound is used for encapsulation. The black AC (hot) lead is shown at 20. The white AC neutral lead is shown at 22. The green pair for the "on" contactor is shown at 24 and the red lead connection wires are shown at 26.
MODE OF OPERATION
As mentioned in the specification which describes the schematic diagram shown in FIG. 2, operation of the switching circuit is based on two Schmitt trigger NAND gates connected as an R-S flip-flop which is set by a momentary ground on one input and reset by a third NAND gate connected to perform the transfer function. The flip-flop circuit is made up of two dual input gates in IC-1, 28A and 28B in FIG. 2. Gate input pin 1 is connected to the ground rail through a 330 k-ohm resistor R3 shunted by a 0.01 ufd capacitor C4 and also to pin 4 of transfer gate 30 through resistor R5, 33 kilo-ohms. Gate input pin 2 is connected to pin 10, the output of the opposite gate 28B. The output pin 3 of gate 28A is connected to input pin 9 of gate 28B and to the bases of transistors Q1 and Q2 through resistors R6 and R10, each 66 k-ohms. The other input, pin 8 of gate 28B is connected to the regulated 10 volt supply through a 33 kilo-ohms resistor R4 shunted by 0.01 ufd capacitor C3. Pins 5 and 6 of transfer gate 30 are connected to the positive terminal of the 220 ufd. timing capacitor C2. The 10 volt regulated DC is applied to pin 14 (V DD ) of IC-1 and pin 7 is connected to the ground rail (V SS ).
Power consumed internally by the switching circuit which is mainly current through zener diode CR-2 and current through transistors Q1 and Q2 and gate current to driver triac Q3 is less than ten milliamps in both the "off" and the "on" modes. Current consumed by the CMOS integrated circuit is negligible. The largest source of heat on the printed circuit board is from the voltage drop in resistor R9.
In the "off" or "standby" mode, the output of gate 28A (pin 3) is at 10 volts positive as is the input (pin 9) of gate 28B. The high output at pin 3 of gate 28A is applied to the bases of transistors Q1 and Q2 which are biased into heavy conduction. The voltage at the positive terminal of timing capacitor C2 is very nearly zero and the voltage at the collector of transistor Q2 is too low to trigger the gate of triac Q3 which holds triac Q4 off and keeps the AC load connected to 26 isolated.
As mentioned, pin 8, the second input to gate 28B is connected to the regulated 10 volt supply through resistor R4; thus, it has a voltage of nine volts in both the "off" and "on" circuit modes. Pin 8 also provides the means for switching the circuit on, and for this reason pin 8 is connected to one side of the control line 24 (FIG. 2). The other control line lead is connected to the ground rail.
A momentary ground on pin 8 (on the order of one to ten milliseconds) will cause gate 28B to conduct, so output pin 10 goes to 10 volts. Pin 10 which is connected to pin 2 of gate 28A shuts off 28A so pin 3, the output of gate 28A, goes to zero volts thus removing the positive voltage from the base of transistors Q1 and Q2. Thus, a voltage appears at the gate of triac Q3 sufficient to turn on Q3 which in turn switches on power triac Q4 and activates whatever AC load is connected to output 26 (FIG. 2). With the base voltage removed from transistor Q1, the external loading on timing capacitor C2 is greatly reduced. The voltage on capacitor C2 which is derived from the 10 volt regulated supply through resistors R8 and R13 starts to rise. When the voltage on C2 which is also applied to pins 5 and 6 of the transfer gate 30 reaches about 6 volts, the output (pin 4) of transfer gate 30 goes low.
Pin 4 is connected to input pin 1 of gate 28A through 33 k-ohm resistor 5. When pin 1 of gate 28A goes low, the gate output at pin 3 goes to nine volts. Pin 3 of gate 28A is connected to input pin 9 of gate 28B which is simultaneously turned off. The positive voltage on pin 3 which is also connected to the bases of transistors Q1 and Q2 switches them into conduction, removing the residual voltage on timing capacitor C2 and on pin 5 and 6 of the transfer gate whose output, pin 4 goes high. Conduction in transistor Q2 removes the gate voltage on triac Q3 which switches off triac Q4, disconnecting the A.C. load. The switching circuit is thus returned to the initial "off" or "standby" mode available for reactivation by a momentary contact across control terminals 24 (FIG. 2).
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that changes in the form and details may be made therein without departing from the spirit and scope of the invention. For example, by substitution of a larger power triac at Q4, it would be possible to increase the maximum of AC current controlled to 25 or more amperes with only a minimum of modifications to the printed circuit board used as a basis for the switching circuit module. Additionally, as described in the specification, the combination of resistors R8 and R13 with timing capacitor C2, permit an AC load "on" time of 5 to 15 minutes to be preselected by adjustment of R13 prior to encapsulation of the module. Other combinations of C2 and R8 will permit considerable latitude in selection of longer or shorter "on" times for various applications. Arrangements for facilitating adjustment of circuit "on" time after or during installation can be made by installing an insulating bushing over the screw driver adjustment on R13, so it can be adjusted after the circuit is potted. A plug of silicone wax could then be used to keep moisture and dirt out of the R13 adjustment hole. | This relates to an electronic circuit which is designed to supply 115 volts AC power to loads of up to 550 watts for a predetermined time period of wide latitude. An "on" cycle is initiated by momentary closure of an external control line pair with a closed contact current flow of less than one half milliampere. The "on" controller may be located at any convenient distance from the load switching circuit and may be a coin operated switch. The electronic power control circuit is fabricated from discrete components including one integrated circuit installed on a printed circuit board (17/8"×27/8") which is finally encapsulated in a hermetically sealed 2"×3" module suitable for operation in a moist or corrosive environment. | 7 |
TECHNICAL FIELD
[0001] This invention relates to methods and apparatus for use in the separation of fluids into components having different specific gravities. The invention finds particular utility in the centrifugal separation of the components of blood.
BACKGROUND
[0002] Centrifugal separation of blood into components of different specific gravities, such as red blood cells, white blood cells, platelets, and plasma is known from U.S. Pat. No. 5,707,331 (Wells). The apparatus shown in that patent employs a disposable processing tube having two chambers, and blood to be separated into components is placed in one of the chambers. The processing tube is placed in a centrifuge, which subjects the blood to centrifugal forces to separate the components. The supernatant is then automatically decanted into the second of the chambers.
[0003] To retain, principally, the red blood cells during the decant of the supernatant, the apparatus disclosed in the Wells patent includes a shelf placed in the first chamber at the expected level of the interface between the red blood cells and the less-dense components, including the plasma. One problem with the arrangement shown in the '331 Wells patent, however, is that the position of the interface varies with the particular proportions of the components (e.g., the hematocrit) of the blood to be processed. Thus, if the shelf is placed at the expected position of the interface for blood of average hematocrit, and the hematocrit of the particular blood being processed is low, the shelf will be above the interface after separation. Such a position of the shelf will hinder the flow of the components near the interface during decanting, thus retaining significant amounts of these components in the first chamber and reducing the separation efficiency of the system.
SUMMARY OF THE INVENTION
[0004] In accordance with the invention, a movable separator disk, which automatically positions itself at the interface between the separated components, is placed in the first chamber. In the preferred embodiment, the disk is capable of moving vertically and is designed to position itself automatically at the interface between red blood cells and the remaining components in the centrifugal separation of blood.
[0005] Decant of the supernatant can be either by gravity drain or by centrifugal transfer, and a main function of the disk is to restrict the flow of the component below it, e.g., red blood cells, during decant. This ensures that the supernatant is not contaminated and increases the efficiency of the process.
[0006] The invention contemplates two embodiments for the disk. In one embodiment, the disk is supported on a central shaft such that an annulus is formed between the perimeter of the disk and the interior surface of the first chamber. The dimensions of the annulus are such that the flow of red blood cells through it during decant is restricted such that they do not contaminate the decanted supernatant to any significant degree.
[0007] In another embodiment, the disk is arranged on the shaft such that, when the chamber is tilted for gravity decanting, the disk rotates such that one edge of the disk engages the wall of the chamber to block flow of red blood cells.
[0008] In either of these embodiments, the specific gravity of the disk and its shape may be chosen so that a major part of the upper surface lies just below the interface, thus facilitating release of the supernatant from the disk during decanting. This upper surface is also preferably curved to match the cylindrical shape the interface assumes during centrifugation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 a is a longitudinal cross-section of a portion of a processing tube chamber and a separator disk in accordance with a first embodiment of the invention.
[0010] FIG. 1 b is a transverse cross section taken along line 1 b - 1 b of FIG. 1 a.
[0011] FIG. 2 a is a longitudinal cross-section of the embodiment of figures 1 a and 1 b when the separator disk is tilted during decanting.
[0012] FIG. 2 b is a transverse cross section taken along line 2 b - 2 b of FIG. 2 a.
[0013] FIG. 3 a is a longitudinal cross-section of a second embodiment of the invention.
[0014] FIG. 3 b is a transverse cross section taken along line 3 b - 3 b of FIG. 3 a.
[0015] FIG. 4 is a longitudinal cross-section of a third embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] With reference to FIGS. 1 and 2 , one chamber 2 of a processing tube, such as that shown in the '331 Wells patent has a separator disk 4 in accordance with the invention supported therein by a central shaft 6 . The shaft 6 is designed to direct fluid introduced into the chamber to the bottom of the chamber. This precludes the formation of an air bubble at the bottom of the chamber, particularly when the bottom of the chamber is tapered. Thus, fluid is introduced into the chamber by inserting a cannula attached to a syringe containing blood into the shaft 6 and discharging the blood from the syringe into the chamber. A central opening 8 in the disk receives the shaft 6 in such a manner that the disk easily slides along the shaft.
[0017] The shaft 6 may not be necessary in all instances, for example, when the bottom of the processing tube is flat. In that instance the disk does not have a central hole.
[0018] The disk is preferably made of material having a specific gravity that allows the disk to float at the interface with red blood cells. In the preferred embodiment that specific gravity is about 1.04 (e.g., polystyrene), which is just less than the specific gravity of red blood cells at 70% hematocrit. Thus, when the blood is centrifuged, the disk moves to the interface between the red blood cells and the other components.
[0019] The interface will naturally assume a cylindrical shape with a cylindrical radius equal to the distance to the center of rotation of the centrifuge. The disk may be cylindrical, to match the shape of the interface.
[0020] In the embodiment shown in FIGS. 1 a , 1 b , 2 a and 2 b , the diameters of the hole 8 and the shaft 6 are such that an annular gap 10 is formed between the outer surface of the shaft and the interior surface of the hole 8 . Similarly, an annular gap 12 is provided between the perimeter of the disk and the interior surface of the tube 2 .
[0021] FIGS. 1 a and 1 b illustrate the position of the disk during centrifugation, and it will be appreciated that the gaps 10 and 12 are large enough to allow passage of the descending heavier components, e.g., red blood cells and the ascending lighter components, e.g., plasma. According to this embodiment, however, the diameter of the central opening 8 is large enough whereby during decanting the disk 4 rotates as shown in the figures. Thus, when the processing tube is rotated to the decant position, the more dense red blood cells, illustrated at 14 , that have accumulated below the disk exert a force against the bottom of the disk as they try to flow through the gap 12 . This causes the disk 4 to rotate, as shown in FIGS. 2 a and 2 b , until a portion of the lower outer edge 16 of the disk and also the upper outer edge 18 engage the inner surface of the chamber 2 . This engagement between the edge 16 of the disk and the interior of the chamber effectively forms a valve that prevents flow of the red blood cells, allowing decant of the plasma supernatant without contamination by red blood cells. It will be appreciated that this embodiment requires the transverse dimension of the disk between edges 16 and 18 to be greater than the internal diameter of the tube so that the edges engage the interior of the tube when tilted.
[0022] A second embodiment is shown in FIGS. 3 a and 3 b . According to this embodiment, the gap 10 is made to be small whereby the disk does not rotate appreciably during decant, in contrast to the embodiment of FIGS. 1 and 2 . It will be appreciated that an annular channel is formed by the gap 12 , this channel having a width equal to the radial dimension of the gap and a length equal to the thickness of the disk at the edge. The rate of flow of a fluid through this channel is a function of the dimensions of the channel, and the dimensions of the disk of this embodiment are such that the red blood cells will not flow appreciably through the channel at 1 G. In the preferred embodiment, the width of the gap is about 0.005 inch to about 0.020 inch, and the length is about 0.1 inch to about 0.3 inch.
[0023] Thus, the components of the blood flow through the channel during centrifugation (i.e., at 1000 G), but do not flow appreciably through the channel during decanting at 1 G. This allows the supernatant to be decanted without significant contamination by the red blood cells.
[0024] FIG. 4 illustrates a preferred shape of the disk 4 . In this embodiment, the top surface 20 of the disk is concave, preferably cylindrical, and the disk is provided with an elongated central portion 22 . The specific gravity of the disk material is selected so that the concave surface 20 is located just below the interface. That is, the thickness of the outer edge, the length of the portion 22 , and the specific gravity of the material are chosen so that the center of buoyancy of the disk is just above the concave surface, and that surface will be just below the interface 26 with red blood cells. This arrangement allows a small layer 24 of the red blood cells to form on the upper surface.
[0025] The layer of red blood cells 24 reduces the surface tension between the platelets at the interface 26 and the surface 20 of the disk and facilitates release of the platelets from the disk. This is important to ensure that all of the platelets are decanted, and the small amount of red blood cells that may be decanted along with the supernatant does not generally represent a significant contamination of the supernatant.
[0026] Modifications within the scope of the appended claims will be apparent to those of skill in the art. | A separator disk for use in centrifugal separation of components is designed to automatically position itself during separation at the interface between the supernatant and the remaining components. Preferably the interface is between plasma and red blood cells. | 1 |
FIELD
Example embodiments relate to methods for estimating an attenuation map in a positron emission tomography and magnetic resonance system (MR-PET).
BACKGROUND
Positron emission tomography (PET) is being used alongside magnetic resonance tomography (MR) in medical diagnostics. While MR is an imaging method for representing structures and slices inside the body, PET allows in vivo visualization and quantification of metabolic activities.
PET uses special properties of positron emitters and positron annihilation in order to quantitatively determine the function of organs and/or cell regions. With this technique, appropriate radiopharmaceuticals marked with radionuclides are administered to the patient prior to the examination. As they decay, the radionuclides emit positrons which after a short distance interact with an electron, causing annihilation to occur. This results in two gamma quanta which fly apart in opposite directions (offset by 180°). The gamma quanta are detected by two opposing PET detector modules within a specific time window (coincidence measurement), as a result of which the annihilation site is localized to a position on the line connecting said two detector modules.
In the case of PET, the detector module generally covers a greater part of a gantry arc length for the purpose of detection. The detector module is subdivided into detector elements having a side length of a few millimeters. On detecting a gamma quantum, each detector element generates an event record that specifies the time and the detection location. This information is passed to a fast logic unit and compared. If two events coincide within a maximum time interval, it is assumed that a gamma decay process is taking place on the connecting line between the two associated detector elements. The PET image is reconstructed using a tomography algorithm, for example, back projection.
In a PET system, such as an MR-PET system, the gamma quanta are attenuated by anything situated between the site of origin of the respective gamma quanta and the PET detector. The attenuation must be taken into account in the reconstruction of PET images in order to prevent image artifacts. Situated between the site of origin of the gamma quantum in the patient's body and the acting PET detector are objects such as tissue within the patient's body, air, and a part of the MR/PET system itself, for example, a patient positioning table. The attenuation values of the objects between the site of origin of the gamma quantum and the acting PET detector are taken into account and compiled into attenuation maps (p maps).
An attenuation map contains attenuation values for each volume element (voxel) of the volume under examination. Thus, for example, an attenuation map can be produced for the patient positioning table. The same applies to, for instance, local coils attached to the patient for MR examinations. In order to produce the attenuation map, the attenuation values are determined and combined. They can be determined by means of, for example, a CT recording or PET transmission measurement of the respective component. Attenuation maps of said kind can be measured on a once-only basis, since the attenuation values do not change over the life of the respective component.
Methods are known by which attenuation values of the patient's body can be determined from anatomical MR images and can be added to the attenuation map. In this case special MR sequences are used by means of which different attenuating tissue classes (e.g., lung tissue), for example, can be identified. With the aid of the MR images it is then possible, based on the position of the attenuating tissue class, to assign appropriate attenuation values to the attenuation map.
However, a transaxial MR field of view is generally smaller than the PET field of view. Therefore, a portion of an object to be examined is only in the PET field of view. Consequently, obtaining attenuation values outside the MR field of view becomes difficult.
MR based estimation of a PET attenuation map may be done either by segmenting the MR image into different tissue types and assigning corresponding attenuation values to the different tissue types. However, this approach does not address the scanned areas outside of the MR field of view.
Recently, maximum-likelihood expectation maximization (MLEM algorithms) has been used to simultaneously reconstruct emission and attenuation maps from PET sinogram data. The PET sinogram data may be referred to as PET raw data, PET counts or PET count data. The term “image” is an image reconstructed from the PET sinogram data. An attenuation map from an MR based segmentation or another known method can be used to initialize the MLEM algorithm.
Other approaches for MR based attenuation correction include the use of an atlas, model or reference image with a known attenuation such as a coregistered corresponding CT, PET transmission image or body contours derived from optical 3D scanning. The actual MR image is then registered to the atlas or reference with known attenuation and the actual attenuation map is deduced from the registration information and additional post-processing methods.
SUMMARY
Example embodiments are directed to model based estimation of a complete or partial PET attenuation map using MLEM.
At least one example embodiment discloses a method of correcting attenuation in a MR scanner and a PET unit. The method includes acquiring PET sinogram data of an object within a field of view of the PET unit and producing an attenuation map based on a maximum likelihood expectation maximization (MLEM) of a parameterized model instance and the PET sinogram data.
At least another example embodiment provides for a method of correcting attenuation in a MR scanner and a PET unit. The method includes acquiring PET sinogram data of an object within a field of view of the PET unit and acquiring MR data of the object within a field of view of the MR scanner. An attenuation map is produced based on a maximum likelihood expectation maximization (MLEM) of a parameterized model instance and the PET sinogram and MR data. The MLEM is constrained by model parameters of the parameterized model instance.
Another example embodiment provides for an apparatus including a positron emission tomography (PET) unit having a plurality of detection units and configured to acquire PET sinogram data of an object within a field of view of the PET unit. A magnetic resonance (MR) scanner is configured to acquire MR data of the object within a field of view of the MR scanner. A computer is configured to produce an attenuation map based on a maximum likelihood expectation maximization (MLEM) of a parameterized model instance and the acquired PET sinogram and MR data, the MLEM being constrained by model parameters of the parameterized model instance.
BRIEF DESCRIPTION OF THE DRAWINGS
Example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. FIGS. 1-4 represent non-limiting, example embodiments as described herein.
FIG. 1 illustrates a device for superimposed MR and PET image representation that may be used in the example embodiments;
FIG. 2 illustrates a method of estimating a complete PET attenuation map using MLEM to reconstruct a PET image according to an example embodiment;
FIG. 3 illustrates a method of estimating a complete PET attenuation map using an MR based attenuation map and MLEM to reconstruct a PET image according to an example embodiment; and
FIG. 4 illustrates a method of refining an initial attenuation map using MLEM according to an example embodiment.
DETAILED DESCRIPTION
Various example embodiments will now be described more fully with reference to the accompanying drawings in which some example embodiments are illustrated. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity.
Accordingly, while example embodiments are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but on the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the example embodiments. Like numbers refer to like elements throughout the description of the figures.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element; without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
Spatially relative terms, e.g., “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or a relationship between a feature and another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the Figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, for example, the term “below” can encompass both an orientation which is above as well as below. The device may be otherwise oriented (rotated 90 degrees or viewed or referenced at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Portions of the example embodiments and corresponding detailed description are presented in terms of software, or algorithms and symbolic representations of operation on data bits within a computer memory. These descriptions and representations are the ones by which those of ordinary skill in the art effectively convey the substance of their work to others of ordinary skill in the art. An algorithm, as the term is used here, and as it is used generally, is conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of optical, electrical, or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
In the following description, illustrative embodiments will be described with reference to acts and symbolic representations of operations (e.g., in the form of flowcharts) that may be implemented as program modules or functional processes include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types and may be implemented using existing hardware. Such existing hardware may include one or more Central Processing Units (CPUs), digital signal processors (DSPs), application-specific-integrated-circuits, field programmable gate arrays (FPGAs) computers or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, or as is apparent from the discussion, terms such as “processing” or “computing” or “calculating” or “determining” of “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical, electronic quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Note also that the software implemented aspects of the example embodiments are typically encoded on some form of program storage medium or implemented over some type of transmission medium. The program storage medium may be magnetic (e.g., a floppy disk or a hard drive) or optical (e.g., a compact disk read only memory, or “CD ROM”), and may be read only or random access. Similarly, the transmission medium may be twisted wire pairs, coaxial cable, optical fiber, or some other suitable transmission medium known to the art. The example embodiments are not limited by these aspects of any given implementation.
The term model may mean any kind of attenuation atlas, anatomical attenuation model, attenuation reference image of an object, or any other reference used to estimate a PET attenuation map. Moreover, a deformable model may be implemented which may capture all reasonable shapes of an attenuating object and capture all possible attenuation values at respective spatial positions. The deformable model may vary in shape and appearance.
The term attenuation appearance model of a model refers to the collection of all possible attenuation coefficients at a spatial position within an object such that each spatial position may have a set of potential attenuation coefficients that may occur. An instance of the attenuation appearance model is a specific setting of attenuation coefficients, one for each spatial position of the object.
FIG. 1 shows a device 1 for superimposed MR and PET image representation that may be used in the example embodiments. The device 1 includes a known MR scanner 2 . The MR scanner 2 defines a longitudinal direction z that extends orthogonally to the drawing plane of FIG. 1 .
As shown in FIG. 1 , a PET unit having a plurality of PET detection units 3 arranged in opposing pairs about the longitudinal direction z is disposed coaxially inside the MR scanner 2 . The PET detection units 3 include an APD photodiode array 5 preceded by an array of cerium doped lutetium orthosilicate (LSO) crystals 4 and an electrical amplifier circuit (AMP) 6 . However, example embodiments are not limited to the PET detection units 3 having the APD photodiode array 5 preceded by an array of LSO crystals 4 , but other kinds of photodiodes, crystals and devices can equally be used for detection purposes.
Image processing for superimposed MR and PET image representation is performed by a computer 7 .
Along its longitudinal direction z, the MR scanner 2 defines a cylindrical first field of view. The plurality of PET detection units 3 defines, along the longitudinal direction z, a cylindrical second field of view. According to example embodiments, the second field of view of the PET detection units 3 essentially coincides with the first field of view of the MR scanner 2 . This is implemented by appropriately adapting the arrangement density of the PET detection units 3 along the longitudinal direction z.
FIG. 2 illustrates a method of estimating a complete PET attenuation map using MLEM to reconstruct a PET image. The MLEM may be any known MLEM. The method of FIG. 2 may be implemented in any PET device or hybrid device with PET modality such as the device 1 illustrated in FIG. 1 .
As shown in FIG. 2 , a statistical model is generated at S 200 . While a statistical model is used for illustrative purposes, it should be understood that any other model that may be parameterized may be used in other example embodiments.
The statistical model may be built by performing principal component analysis of deformation fields and attenuation maps resulting from coregistrations of data sets. Data sets may be obtained from scans of multiple individuals and either simple attenuation maps or, corresponding pairs of MR image data and an image from which an attenuation map can be induced (e.g., MR and CT image pairs from each individual). By coregistering data sets, statistical variations of a shape (e.g., an arm) and attenuation values may be captured. Principal component analysis allows for a more compact representation of the parameter space to be developed.
Principal components may be obtained from principal axis transformations of a covariance matrix of input data such as deformation parameters and attenuation parameters. The principal components are the principal Eigen vectors of the covariance matrix of the input data. Transforming the input data to the principal axis produces a compact linear representation of the input data, from which new instances of the model can be generated by linear combinations. Varying linear combination coefficients of the principal components produce other instances of the statistical model.
It should be understood that statistical analysis methods other than principal component analysis, such as clustering analysis, may be used to reduce dimensionality.
The statistical model may be of the complete body or of any arbitrary body part. For example, the statistical model may be a kinematic arm model in combination with an attenuation map of human arms or a statistical atlas and statistical attenuation map of the complete body, for example. The statistical model may be similar to the model described in Rueckert et al. “Automatic Construction of 3D Statistical Deformation Models Using Non-rigid Registration.” Lecture Notes in Computer Science , vol. 2208 (2001), 77-84 or Fenchel et al. “Automatic Labeling of Anatomical Structures in MR FastView Images Using a Statistical Atlas.” Lecture Notes in Computer Science , vol. 5241 (2008), 576-84, except that these models are based on grey value images instead of attenuation maps.
The statistical model is parameterized by deformation parameters d i and attenuation appearance parameters a i for each instance i. The deformation parameters d i parameterize the shape of the object. The attenuation appearance parameters a i parameterize the attenuation coefficients at the spatial positions. Examples of attenuation appearance parameters a i are attenuation values of different tissue types at their respective spatial position at 511 keV, for example, lung tissue attenuation 0.018/cm.
Both the deformation parameters and the attenuation appearance parameters are obtained from the coregistered data sets. The covariance matrix over all input instances is then computed. From covariance matrices of the parameters, principal components are extracted. An instance of the statistical model can then be described by a linear model:
μ = ∑ i = 0 ( p i * w i ) ( 1 )
where μ is the instance of the statistical model, p i are the principal components and w i is the coefficient for the i-th principal component in the linear equation. Generally, the coefficients are selected from an interval of three sigma of the principal values. The coefficients w i may be the deformation parameters d i for 1<i<m and w i may be the attenuation appearance parameters a i for m+1<i<n.
Therefore, arbitrary instances may be created by assigning different coefficients. While the example embodiment of generating and parameterizing a statistical model is described above, it should be understood that other methods may be used for other models.
Affine parameters A i , including spatial transformation parameters like such as rotation and translation, may be used to arbitrarily align and scale the statistical model in space. Moreover, A i can be used to setup a matrix M and a translation vector t by which each spatial position may be transformed to:
A ( x )= M*x+t (2)
after deformation, where x is a vector of a spatial position.
It should be understood that the statistical model may be parameterized by other parameters instead of, or, in addition to the deformation parameters, the attenuation appearance parameters and the affine parameters.
Based on the statistical model, a PET attenuation map given by the model instance μ is created at S 210 (e.g., an average model). The PET attenuation map given by the model instance μ may be estimated by the computer. More specifically, the attenuation map for the model instance μ may be a function of d i , a i and A i and is defined as:
μ(d i ,a i ,A i ) (3)
L is a log likelihood of an emission image (emitter distribution) L(λ,μ) where λ is an emission image (the spatial distribution of the positron emission). The emission image λ is based on an initial emitter distribution image that is computed from PET sinogram data, for example, by back projection. The attenuation map given by the model instance μ is a function of the deformation parameters d i and the attenuation appearance parameters a i the affine parameters A i , as shown above. Therefore,
(λ, μ ( d i ,a i ,A i ))=arg max ( L (λ, μ ( d i ,a i ,A i ))) (4)
becomes the parameter setting for the maximum likelihood. Furthermore, it should be understood that the emission image λ may also be parameterized by a model, for example, the statistical model. Moreover, it should be understood that other measures may be integrated into an extended likelihood. For example, if a statistical distribution of the model parameters is known or can be approximated, the likelihood of the model instance itself could be integrated into the likelihood measure.
The larger the amount of data sets, the more comprehensive the statistical model will be and thus, the more generalized the statistical model will be. It should be understood that the statistical model is a possible embodiment of a deformable model and that each instance i of the statistical model is a function of the model parameters for that instance. For example, the deformation parameters d i and the attenuation appearance parameters a i the affine parameters A i are model parameters.
PET sinogram data of an object within a field of view of a PET unit is acquired at S 215 . The PET sonogram data may be acquired by the PET unit shown in FIG. 1 . Based on the PET sinogram data, the emission image λ (PET image) is computed simultaneously with the model parameters. Alternatively, the emission image λ and the statistical model may be computed alternatively by first keeping the emission image λ fixed and updating the statistical model, then keeping the statistical model fixed and updating the emission image.
The emission image λ and the model parameters for that instance are optimized at S 220 based on the PET sinogram data. The emission image λ and the model parameters for that instance are optimized in an iterative fashion. During optimization, the emission image λ is computed, the statistical model is updated and the emission image λ is recomputed until optimization has been reached. The model parameters may be the deformation parameters d i , the attenuation parameters a i and the affine parameters A i .
At S 220 , the PET attenuation map given by the model instance μ and the emission image λ are reconstructed simultaneously based on a MLEM function. The computer shown in FIG. 1 may reconstruct the emission image λ and the PET attenuation map given by the model instance μ. The emission image λ and the PET attenuation map given by the model instance μ may be reconstructed and optimized based on the log-likelihood of the (un-truncated) measured PET emission which is defined as follows:
L ( λ , μ ( d i , a i , A i ) ) = ∑ i = 0 ( y 1 * log ( y i ′ ) - y 1 ′ ) ( 5 )
where y i is the measured PET sinogram data and y i ′ is the estimated y i value. y i ′ is estimated by forward projecting the emission image λ and correcting attenuation by the attenuation map given by the model. L can then be optimized as a function of the parameters d i , a i and A i and λ. Here, constraining the MLEM to the parameter space of the model is used to estimate the complete attenuation map. The parameter space means all possible values of the parameterized statistical attenuation model. In the example embodiment shown in FIG. 2 , the parameter space may include all model parameters, for example, all deformation, attenuation appearance and affine transformation parameters.
The model parameters are optimized in an iterative fashion until a maximum likelihood has been reached. The optimum can be found by any common optimization algorithm. The optimum is the parameter setting for which the maximum likelihood reaches a maximum value. The optimum defines the most likely instance of the parameterized model for attenuation and emitter image.
When the optimization algorithm at S 220 has converged, the optimum maximum likelihood has been reached. The attenuation map is then obtained directly from the model instance and the PET image from the emission image at S 225 . It should be understood that the emission image obtained at S 225 may be discarded when another PET image reconstruction is triggered using the attenuation map.
FIG. 3 illustrates a method of estimating a complete PET attenuation map using an MR based attenuation map and MLEM to reconstruct a PET image according to an example embodiment. The method of FIG. 3 may be implemented in any PET device or hybrid device with PET modality such as the device 1 illustrated in FIG. 1 .
As shown in FIG. 3 , a statistical model is generated at S 300 . S 300 is the same as S 200 . Therefore, a detailed description of S 300 will be omitted for the sake of clarity and brevity.
At S 305 a , an object is scanned by an MR unit within the field of view of the MR unit to acquire MR data. The MR scanner shown in FIG. 1 may be used to acquire the MR data.
Once the object is scanned, an MR based attenuation map is produced at S 305 b . The MR based attenuation map may be generated by any known method of generating an MR based attenuation map and may be produced by the computer shown in FIG. 1 .
Based on the MR based attenuation map and the statistical model, a PET attenuation map for a model instance μ is created at S 310 . S 310 is the same as S 210 , except that the PET attenuation map for the model instance μ is constrained by the MR based attenuation map. Therefore, a detailed description of S 310 will be omitted for the sake of clarity and brevity.
PET sinogram data of an object within a field of view of a PET unit is acquired at S 315 . S 315 is the same as S 215 .
At S 320 , the model parameters for the instance are optimized. S 320 is the same as S 220 . The model parameters are optimized until a maximum likelihood has been reached.
Once a maximum likelihood of the PET attenuation map for the model instance μ and the emission image λ has been reached, the attenuation map for the model instance μ defines an optimal attenuation map for the model instance μ at S 325 . The reconstructed PET image is also produced at S 325 , but may be discarded when the optimal attenuation map for the model instance μ can be used in another reconstruction process to obtain a PET image. Methods of combining MR based attenuation maps and PET attenuation maps are known in the art. Therefore, for the sake of clarity and brevity, they will not be discussed.
FIG. 4 illustrates a method of refining an initial attenuation map using MLEM according to an example embodiment. The method of FIG. 4 may be implemented in any PET device or hybrid device with PET modality such as the device 1 illustrated in FIG. 1 . As shown in FIG. 4 , at S 400 , a statistical model is generated in the same mariner as in FIGS. 2 and 3 .
At S 402 , the statistical model being parameterized is adapted to an initial attenuation map. The initial attenuation map may be generated beforehand from a low-resolution MR image or a transmission scan, for example. In another example embodiment, a parameterized model that includes anatomy which frequently extends outside a MR field of view (e.g., a kinematic model of the human arms) may be added to the initial attenuation map or may be used to complete the initial attenuation map.
At S 405 , an object is scanned by an MR unit within the field of view of the MR unit to produce an MR image. At S 410 , a model instance is created. The model instance is created based on a best fit of the initial attenuation map with respect to a least squares approach. For statistical models, the best fit may be computed by performing an orthogonal projection of the initial attenuation map to the linear space of the statistical model, for example. Thus, the model that is created is an average instance of the statistical model scaled to the initial attenuation map.
At S 415 , PET sinogram data is scanned and then the model parameters of the attenuation map for the model instance μ are optimized at S 420 . S 415 and S 420 are the same as S 215 and S 220 , respectively. Therefore, S 415 and S 420 will not be described in greater detail, for the sake of clarity and brevity. At S 420 , the initial attenuation map is refined using MLEM.
At S 425 , a refined attenuation map is produced based on the maximum likelihood of the attenuation map for the model instance μ. A PET image is also produced.
As described above, the methods may be used for estimating a complete attenuation map of an object based on a model using MLEM reconstruction and/or to complete missing parts of an attenuation map which is computed with other methods before by means of a model. Moreover, the example embodiments may be used for refining an attenuation map such as attenuation maps computed from MR-based attenuation map computation methods including initialization of the model and refinement to the data. The example embodiments aid in avoiding local maxima and generate valid and meaningful instances of a model within its parameter space, atlas or reference image.
Example embodiments 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 example embodiments, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the example embodiments. | Example embodiments are directed to a method of correcting attenuation in a magnetic resonance (MR) scanner and a positron emission tomography (PET) unit. The method includes acquiring PET sinogram data of an object within a field of view of the PET unit. The method further includes producing an attenuation map based on a maximum likelihood expectation maximization (MLEM) of a parameterized model instance and the PET sinogram data. | 0 |
BACKGROUND OF THE INVENTION
A well known method of shaping a waistband or belt (hereinafter referred to as belt) is that of attaching the lower portion, formed to have a larger radius than the upper portion, to an article of clothing so that its assembled configuration will conform generally to the natural curve of a person's pelvis.
Shaped belts are presently formed by two pieces of fabric that correspond in both length and shape and which are sewn together by means of a single row of stitches applied to the upper and lower edges thereof.
Belts are also formed by folding an elongated and preformed section of fabric end to end and then sewing single lines of stitches along opposite sides thereof.
With both methods of shaping belts the single seams on each side are separately sewn on a sewing machine of the single needle type due to the fact that the lower line of stitches is of greater length than the upper line of stitches.
Frequently, the seam formed along the lower portion of a belt is also utilized for the purpose of attaching said belt to an article of clothing.
The present invention has substantially simplified the method of shaping a belt by providing a means whereby the upper and lower parallel lines of stitching can be simultaneously formed with a sewing machine of the double needle type.
SUMMARY OF THE INVENTION
The improved feeding machanism according to the present invention is applicable to a sewing machine having two needles which operatively associated with the machine's lower stitch forming instrumentalities are effective in simultaneously forming a single line of stitches adjacent both the upper and lower sides of a belt.
The mechanism includes first and second fabric feeding devices which are effective upon the upper and lower sides respectively of a belt.
Additionally, the first feeding device has a length of stroke movement which is different from that of the second feeding device and provides the means for forming a longer line of stitches on one side of the belt relative to the opposite side.
These and other features of the present invention will be made apparent in the course of the following description of a preferred embodiment thereof provided with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a part of the sewing machine according to the present invention; and
FIG. 2 is a diagrammatic view of an embodiment of a belt.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 a throat plate 1 is shown mounted on a work bed plate 2 of a conventional sewing machine (not shown).
A first feed dog 3 disposed in operative association with a needle 4 projects from the throat plate 1 and a second feed dog 5 laterally spaced from and in alignment with said first feed dog 3 is disposed in operative association with a needle 6 both of which are effective in advancing a workpiece in the direction of the indicating arrow 7.
A first roller 8 is located rearwardly of and in alignment with the first feed dog 3 and a second roller 9 is disposed rearwardly of and in alignment with the second feed dog 5.
Both of the rollers 8 and 9 are fixed on a shaft 10 which is driven by any suitable means not shown so as to cause rotatable indexing of said rollers.
The two feed dogs 3 and 5 are independently driven in well known rectangular movements by conventional means (not shown).
The indexing movement of the first roller 8 corresponds to the feed advancement stroke of the feed dog 3 and similarly, the indexing movement of the second roller 9 corresponds to that of the feed dog 5. With both rollers being fixed on the same shaft 10, the difference in indexing movements of the rollers is accomplished by providing rollers with different diameters and, more specifically, the diameter of the roller 8 is larger than that of the roller 9.
The difference in the diameter of the rollers 8 and 9 must be proportional to the stroke difference between the two feed dogs 3 and 5.
The two rollers 8 and 9 are continually urged by conventional biasing means (not shown) either toward the work bed plate 2 or underlying idle rollers (also not shown). With reference to FIG. 2, the above-described machine is adapted to form shaped belts from a rectilinear strip 11.
The strip is inserted in a well known guide means (not shown) which is adapted to fold the strip in a desired manner.
The folded strip 11 is then advanced by the feed dog 3 and the roller 8 which form a first feeding mechanism and by the feed dog 5 and the roller 9 which form a second feeding mechanism.
Two spaced lines of stitches 12 and 13 are produced by the combinations of the two feeding mechaniss, the needles 4 and 6 and the lower stitching instrumentalities (not shown). The different advancement strokes of the two feeding mechanisms cause the rectilinear strip 11, for forming a belt 14, to assume a shape in which the lower line of stitches 12 are of greater length than the upper line of stitches 13.
With the above-described apparatus it is possible to form a shaped belt 14 independently or during fabrication thereof to simultaneously attach the belt to an article of clothing 15 by means of the lower line of stitches 12.
The above-described apparatus can also be utilized to fabricate a shape belt 14 by utilizing a strip of material that has been pre-formed to produce the desired belt configuration.
With one feeding mechanism having a longer feed stroke than the other, two parallel lines of stitches can be formed simultaneously and the line of stitches adjacent the lower edge of the belt will be of greater length than the one adjacent the upper edge thereof.
In the above description specific reference has been made to belts adapted for attachment to slacks or skirts in which the lower edge is of larger diameter than the upper edge so as to conform to the body shape of the wearer.
In the case of shaped belts to be attached, for example, to bodices, in which the upper part must be of a larger diameter than the lower, the means for displacing the feed dog 3 must be such that its advancement stroke is shorter than the advancement stroke of the feed dog 5 and the diameter of the roller 8 must also be less than the diameter of the roller 9.
Accordingly, the first feeding mechanism requires a shorter feed advancement stroke than that of the second feeding mechanism.
Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention and the appended claims. | An improved feeding mechanism for a sewing machine for producing shaped belts in which two needles are used to effect simultaneous stitching of each side of the belt to be formed and which utilizes separate feeding means for advancing the fabric to the needle area, the feeding means being adapted to effect different rates of advancement of the fabric in the sewing zone. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of semiconductor memories. More specifically, the present invention relates to managing data addressing in a semiconductor memory.
2. Description of the Related Art
In semiconductor memory devices, and in particular non-volatile electrically programmable memories, “flash” memories find various applications. The cells of a flash memory typically consist of floating gate MOS transistors, and they are adapted to store a logic value defined by the threshold voltage of the MOS transistors, which depends on the electric charge stored in the floating gate. The cells of a flash memory are individually programmable (i.e., they can be “written”), while erasing occurs simultaneously for a great number of cells; typically, the cells of a flash memory are organized in memory sectors, each of which is individually erasable.
For example, in bi-level flash memories, where each cell is adapted to store one bit of information, in an erased condition the generic cell has a low threshold voltage (the logic value 1 is typically associated therewith); the cell is programmed by the injection of electrons into its floating gate; in this condition the cell has a high threshold voltage (the logic value 0 is typically associated therewith). In multilevel flash memories, each cell is adapted to store more than one bit of information, and it can be programmed in a selected one among a plurality of different states, which correspond to respective threshold voltage values.
For retrieving or storing data, the memories comprise a system for decoding address codes (in the following, for the sake of brevity, addresses) and for selecting corresponding memory locations. In particular, the memory cells are typically arranged according to a plurality of rows and a plurality of columns so as to form a so-called matrix, and the decoding and selecting system comprises a row selector, adapted to decode row addresses and to select one or more matrix rows, and a column selector adapted to decode column addresses and to select one or more columns.
Typically, the flash memories implement a decoding and selecting system suitable to apply positive voltages to the matrix rows during programming operations, and negative voltages during erasing operations. In particular, for programming and erasing, the decoding system has to be adapted to manage voltages (in absolute value) quite higher (for example, for the erasing operation voltages of the order of −9 V can be needed, while for the programming operation 12 V may have to be supplied) than the supply voltages of the device (typically, 1.8 V to 3.3 V).
In single-supply voltage devices, the voltages needed to perform programming and erasing operations are generated inside the memory, starting from the supply voltage, by suitable circuits. Alternatively, such voltages can be provided to the device from the outside, through suitable terminals.
The row selector of a flash memory typically comprises, for each sector, low-voltage pre-decoding and decoding circuits (i.e., operating at voltages of the order of the supply voltage), and level shifters for shifting the signals necessary for the selection of the rows in the programming and erasing operations to the required voltages; for example, for the programming operation the level shifters have to shift the row selection signals to a high voltage.
The row selector of a flash memory generally occupies a wide area of the integrated circuit chip.
In particular, a wide portion of the area of the row selector is occupied by the level shifters, which, for their structure, require the use of relatively large transistors for each sector. The problem becomes greater as the number of sectors present in the memory increases.
This contrasts the increasing request for optimizing the ratio between area of the device and data storage capability.
BRIEF SUMMARY OF THE INVENTION
One embodiment of the present invention proposes a solution that is based on the idea of modifying the structure of the memory cell selector inside the memory of, for example, the matrix rows, in order to reduce the area occupied by the selector itself and, accordingly, the overall size of the memory device.
In particular, an embodiment of the present invention proposes a memory device including: a plurality of memory cells, said memory cells being grouped in at least two memory sectors, a respective memory cell address signal line being associated with each alignment; a first decoding circuit adapted to receive an address code of the memory cells and, in response thereto, to assert a plurality of decoding and selecting signals common to said at least two memory sectors; associated with each one of said at least two memory sectors, a respective second decoding circuit operatively coupled to the first decoding circuit and adapted to generate driving signals of said address lines depending on said decoding and selecting signals. The device further comprises voltage boosting blocks adapted to receive said common decoding and selecting signals and to shift them in voltage to a shifted voltage level for generating respective shifted decoding and selecting signals common to the at least two memory sectors, and to provide them to the second decoding circuits for the generation of the driving signals.
Another embodiment of the present invention provides a corresponding method of operation of a memory device.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The elements that characterize the present invention are indicated in the appended claims. Moreover, the invention, as well as further features and the advantages thereof, will be better understood with reference to the following detailed description, provided merely by way of non-limiting examples, to be read in conjunction with the attached figures. In particular:
FIG. 1 shows a schematic block diagram of a memory device according to an embodiment of the present invention, referencing blocks of interest in the understanding of the invention.
FIG. 2 shows in greater detail a portion related to a sector of the memory device shown in FIG. 1 , according to an embodiment of the present invention.
FIG. 3 shows an example implementation of a voltage booster block according to an embodiment of the present invention.
FIG. 4 shows a portion of a block for generating control signals of row driving circuits, in which the solution according to an embodiment of the present invention may be utilized.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , a memory device 100 is represented in a simplified way, in terms of the circuit blocks of interest in the understanding of the embodiment of the invention described herein. In the embodiment described herein, the memory device 100 is a non-volatile memory device, in particular of the electrically programmable and erasable type and, even more particularly, a flash memory device, which comprises a plurality of flash memory cells MC. The flash memory cells MC are grouped in a plurality of memory sectors S 0 , . . . , S Ns-1 each one individually erasable. For example, 32 sectors of flash memory cells MC can be provided.
Each memory sector S 0 , . . . , S Ns-1 comprises a bi-dimensional arrangement of flash memory cells MC, arranged in memory cell rows and memory cell columns (hereinafter referred to as rows and columns for short).
In particular, the memory cells of a same column are connected to a bit line, while the cells of a same row are connected to a word line. In detail, the generic memory sector comprises a plurality of word lines WL 0 , . . . , WL Nw1-1 and a plurality of bit lines BL 0 , . . . , BL Nb1-1 . In the memory device 100 , a power-supply managing unit 140 and an output block 150 are also provided. The power-supply managing unit 140 provides the voltages (indicated in general herein as Vin) used for managing the various operations on the memory device 100 , for example a voltage of about 12 V for the programming operations of the cells, a voltage of about −9 V for the erasing operations of the sectors; the voltages Vin are generated (for example, by charge pumps) starting from a supply voltage Vdd provided from the outside (typically, a voltage that can assume values in the range from about 1.8 V to about 3.3 V). The output block 150 comprises the circuitry (such as, for example, the sense amplifiers and the input/output data interface—“buffer”—circuits) necessary for the retrieval of the data stored in the matrix of flash memory cells MC and their outputting from the memory.
For the selection of the memory cells MC, the memory device 100 is adapted to receive, through addressing signals ADD, address codes of the cells.
In particular, the memory device 100 provides a pre-decoding circuit 110 of the addressing signals ADD, a voltage booster block 117 included in a row and column decoding and selection circuit 115 ; the row and column decoding and selection circuit 115 comprises a plurality of row decoder and selector blocks 120 r 0 , . . . , 120 r Ns-1 and a plurality of column decoder and selector blocks 120 c 0 , . . . , 120 c Ns-1 . In particular, the generic row decoder and selector block and the generic column decoder and selector block interface with the corresponding sector.
Furthermore, the memory device 100 provides a sector voltage booster block 130 r 0 , . . . , 130 r Ns-1 and a column voltage booster block 130 c 0 , . . . , 130 c Ns-1 for each row decoder and selector 120 r 0 , . . . , 120 r Ns-1 and for each column decoder and selector 120 c 0 , . . . , 120 c Ns-1 , respectively.
As it will be better described in the following, the voltage booster blocks 117 , 130 r 0 , . . . , 130 r Ns-1 and 130 c 0 , . . . , 130 c Ns-1 are adapted to bootstrap the voltages at their input (typically of the order of the supply voltage Vdd, i.e., for example, voltages in the range between 1.8 V and 3.3 V) to output voltages of the order of the voltages Vin necessary for the programming and erasing operations, and then, for example, 12 V in the case of a programming operation.
Each row decoder and selector 120 r 0 , . . . , 120 r Ns-1 comprises a respective block 160 for generating control signals of row driving circuits, included in a respective row driving block 170 .
In particular, the row driving block 170 of the generic row decoder and selector 120 r 0 , . . . , 120 r Ns-1 comprises a plurality of said row driving circuits WLD 0 , . . . , WLD Nw1-1 , each one including a CMOS inverter (as shown in FIG. 4 , that will be described in detail in the following); the generation block 160 of the generic row decoder and selector 120 r 0 , . . . , 120 r Ns-1 comprises a plurality of circuits GENG 0 , . . . , GENG Ngp-1 for generating gate signals for the MOSFETs of the CMOS inverters forming the row driving circuits WLD 0 , . . . , and a plurality of supply signal generator circuits GENS 0 , . . . , GENS Nsp-1 for said CMOS inverters (for example, as shown in FIG. 4 , signals to be applied to the source terminals of the p-channel MOSFETs of the CMOS inverters).
During operation, the memory device 100 receives an address, for selecting the location, or the set of locations of the memory device, which shall undergo conventional operations, such as programming, reading and/or erasing; the address, supplied by the addressing signals ADD, is provided in input to the pre-decoding circuit 110 .
The pre-decoding circuit 110 manages the switching-on, starting from the received address, of groups LSLV, LXLV, LYLV, LZLV, PLV and QLV of pre-decoding signal lines, which, for example, can assume voltage values equal to the reference voltage GND or to the supply voltage Vdd, depending on their switching on/off state.
In greater detail, the group of lines LSLV comprises a plurality of lines LSLV 0 , . . . , LSLV Ns-1 , each one corresponding to one among the sectors S 0 , . . . , S Ns-1 and adapted to the selection of the desired sector. For this purpose, each line of the group LSLV 0 , . . . , LSLV Ns-1 is provided in input to a corresponding sector voltage booster block 130 r 0 , . . . , 130 r Ns-1 , which, through a corresponding sector selection line LSHV 0 , . . . , LSHV Ns-1 shifted in voltage, provides a sector selection signal, properly shifted in voltage, of the order of the voltages Vin to the respective row decoder and selector 120 r 0 , . . . , 120 r Ns-1 . For example, when, during a programming operation, it is desired to select the generic sector, for programming the memory cells thereof, the voltage of the corresponding line LSHV 0 , . . . , LSHV Ns-1 assumes a relatively high value (for example, 12 V) while the remaining lines of the group LSHV are typically kept at ground.
The groups LXLV, LYLV, PLV, and QLV of signal lines comprise respective pluralities of signal lines LXLV 0 , . . . , LXLV X-1 ; LXLV 0 , . . . , LYLV Y ; PLV 0 , . . . , PLV P-1 ; and QLV 0 , . . . , QLV Q-1 to which correspond respective pluralities of voltage-shifted signal lines LXHV 0 , . . . , LXHV X-1 ; LYHV 0 , . . . , LYHV Y-1 ; PHV 0 , . . . , PHV P-1 and QHV 0 , . . . , QHV Q-1 , belonging to groups LXHV, LYHV, PHV, and QHV of voltage-shifted signal lines, respectively. In greater detail, the voltage booster block 117 receives in input the signal lines LXLV 0 , . . . , LXLV X-1 ; LYLV 0 , . . . , LYLV Y-1 ; PLN 0 , . . . , PLV P-1 ; and QLV 0 , . . . , QLV Q-1 provided by the pre-decoding circuit 110 , and in output it drives the voltage-shifted signal lines LXHV 0 , . . . , LXHV X-1 ; LYHV 0 , . . . , LYHV Y-1 ; PHV 0 , . . . , PHY P-1 and QHV 0 , . . . , QHV Q-1 .
In particular, the signal lines LXHV 0 , . . . , LXHV X-1 ; LYHV 0 , . . . , LYHV Y-1 ; PHV 0 , . . . , PHV P-1 and QHV 0 , . . . , QHV Q-1 are adapted to select a set of word lines (for example, a single word line at a time), to which the cells to be submitted to conventional operations inside the selected memory sector are connected. In fact, during the operation of the memory device 100 , the generic row decoder and selector 120 r 0 , . . . , 120 r Ns-1 corresponding to the selected sector receives the signals supplied by the groups of signal lines LXHV, LYHV, PHV and QHV and, starting from the latter, it generates, by way of the generation block 160 , the control signals of the row driving circuits of the driving block 170 .
Under the control of the generation block 160 , the row driving block 170 properly biases the word lines of the selected memory sector. In particular, the biasing voltage of a generic word line WL 0 , . . . , of the selected sector is set by the corresponding driving circuit WLD 0 , . . . , WLD Nw1-1 and it assumes a different value depending on the operation which has to be performed, and on whether the word line is selected or not. For this purpose, a number of driving circuits [is] are provided, equal to the number of word lines of the sector. For example, during a programming operation the word line WL 0 , . . . , WL Nw1-1 , to which a gate terminal of the selected cell MC is connected, receives a suitable row programming voltage from the corresponding driving circuit WLD 0 , . . . , WLD Nw1-1 , for example equal to about 12 V. The other word lines of the sector are kept at a reference voltage to inhibit the programming operation of the cells connected thereto (typically, ground). By contrast, during an erasing operation of a selected sector, all the word lines belonging to the sector receive a suitable erasing voltage, for example equal to −9 V.
For example, in the case of a memory device having 32 sectors (i.e., with Ns=32), each one including, for example, 256 word lines, the group LSHV of signal lines comprises 32 signal lines, and the groups of LXHV, LYHV, PHV and QHV of signal lines comprise (as shown in FIG. 2 ) the signal lines LXHV 0 , . . . , LXHV 3 , LYHV 0 , . . . , LYHV 3 , PHV 0 , . . . , PHV 3 and QHV 0 , . . . , QHV 3 (i.e., in the considered example it is X=4, Y=4, P=4 and Q=4), respectively. Each word line is identified by way of a suitable switching-on combination of the lines LXHV 0 , . . . , LXHV 3 , LYHV 1 , LYHV 3 , PHV 0 , . . . , PHV 3 , and QHV 0 , . . . , QHV 3 .
The group of lines LZLV comprises a plurality of lines LZLV 0 , . . . , LZLV Z-1 which are provided to a corresponding column voltage booster block 130 c 0 , . . . , 130 c Ns-1 , which, through a corresponding group of voltage-shifted column selection lines LZHV 0 , . . . , LZHV Z-1 , provides column selection signals properly shifted in voltage and consistent with the considered voltage values in the specific operation that is performed on the memory to the related column decoder and selector 120 0 , . . . , 120 Ns-1 . For example, when, during a programming operation, it is desired to select the bit line of the cell to be programmed, the voltage of the corresponding line LZHV 0 , . . . , LZHV Z-1 assumes a relatively high value (for example, 5 V), while the remaining lines of the group LZHV are typically kept at ground, or left floating.
With reference to FIG. 2 , an example structural diagram of a portion of the device 100 is shown, in which the plurality of word lines WL 0 , . . . , WL Nw1-1 of the selected sector S i (a generic sector among the above-mentioned sectors S 0 , . . . , SNs- 1 ) comprises, for example, 256 word lines WL 0 , . . . , WL 255 (Nw 1 =256). The word lines are ideally divided into a plurality Ngp (in the example at issue, Ngp=16) of packets P 0 , . . . , P 15 each one including a number of word lines equal to Nsp (in the example at issue, Nsp=16). A corresponding driving circuit WLD 0 , . . . , WLD Nw1-1 , belonging to the row driving block 170 , is associated with each generic word line WL 0 , . . . , WL 255 .
In FIG. 2 the voltage booster block 117 and the generation block or row driving signal generator block 160 corresponding to the selected sector S i are also shown.
The voltage booster block 117 comprises a plurality of elemental voltage booster blocks 210 . In particular, one among the elemental voltage booster blocks 210 corresponds to each signal line belonging to the groups of signal lines LXLV, LYLV, PLV and QLV.
In particular, the number (indicated by the index m) of elemental voltage booster blocks 210 included in the memory device 100 is given by: m=X+Y+P+Q in which X, Y, P, and Q represent the number of signal lines comprised in the groups of signal lines LXLV, LYLV, PLV and QLV (in the example considered in FIG. 2 , m=16), respectively.
It is noted that the number of elemental voltage booster blocks 210 included in the voltage booster block 117 depends on the type of implemented row decoding, i.e., on the number of pre-decoding levels and on the number of the pre-decoding signal lines.
In the example at issue, since each group of signal lines LXLV, LYLV, PLV and QLV comprises the four signal lines LXLV 0 , . . . , LXLV 3 , LYLV 1 , . . . , LYLV 3 , PLV 0 , . . . , PLV 3 , and QLV 0 , . . . , QLV 3 , the number of elemental voltage boosters 210 is equal to 16.
During the operation of the memory device 100 , for example, during a programming operation of the desired cell MC belonging to the selected sector S i , the voltage booster block 117 receives the low-voltage signals (for example, depending on the switching-on state, assuming voltages equal to ground or to the supply voltage Vdd, for example 3.3 V or even 1.8 V) by means of the signal lines LXLV 0 , . . . , LXLV 3 ; LYLV 0 , . . . , LYLV 3 ; PLV 0 , . . . , PLV 3 ; QLV 0 , . . . , QLV Q-1 ; and it provides as output signals shifted to a high voltage (for example, depending on the switching-on state, assuming voltages equal to ground or to 12 V) by means of the signal lines LXHV 0 , . . . , LXHV 3 ; LYHV i , . . . , LYHV 3 ; PHV 0 , . . . , PHV 3 and QHV 0 , . . . , QHV 3 . In particular, each elemental block booster 210 receives the corresponding low-voltage signal and shifts it in voltage providing it in output from the corresponding line.
The row driving signal generator block 160 receives [in] as input the voltage-shifted signals supplied by the signal lines LXHV 0 , . . . , LXHV 3 , LYHV 0 , . . . , LYHV 3 , PHV 0 , . . . , PHV 3 QHV 0 , . . . , QHV 3 and, starting from the latter, generates a plurality Ngp (in the example at issue, Ngp=16) of gate driving signals GP 0 , . . . , GP 15 for driving the MOSFETs of the CMOS inverters forming the row driving circuits WLD 0 , . . . , WLD 255 , and a plurality Nsp (in the example at issue, Nsp=16) of supply signals SP 0 , . . . , SP 15 for supplying the CMOS inverters.
In particular, the number Ngp of the gate driving signals GP 0 , . . . , GP 15 and the number Nsp of the supply voltage signals SP 0 , . . . , SP 15 generated by the block for generating row driving signals 160 are such that: Nw 1 =Ngp*Nsp in which, as already mentioned, Nw 1 indicates the number of word lines comprised in the selected sector S i .
In this way, each one among the gate signals GP 0 , . . . , GP 15 corresponds to a respective word line packet P 0 , . . . , P 15 and drives all the driving circuits related to the corresponding word line packet. Furthermore, the generic voltage signal SP 0 , . . . , SP 15 supplies a driving circuit for each word line packet P 0 , . . . , P 15 .
It is noted that each driving circuit WLD 0 , . . . , WLD 255 belonging to the generic packet drives the voltage of the corresponding word lines of the packet depending on the voltage level of the gate signal and of the supply signal received from the block 160 .
With reference to FIG. 3 , a circuit scheme of the generic elemental voltage booster block 210 is shown, which in particular is adapted to boost a voltage signal supplied by a generic one among the lines of the group LXLV, for example, the line LXLV 0 ; the remaining elemental voltage booster blocks have identical structure. The elemental voltage booster block 210 comprises an inverter 310 (or equivalently an odd number of inverters), for example, of CMOS type, and a voltage-shifter block 315 .
The inverter 310 has an input terminal connected to the signal line LXLV 0 and an output terminal connected to the shifter block 315 . Furthermore, the inverter 310 is supplied by the supply voltages Vdd and GND.
The voltage-shifter block 315 has a latch structure, which comprises two p-channel MOSFET transistors P 2 and P 3 and two n-channel MOSFET transistors N 2 and N 3 . The transistors P 2 and P 3 have the corresponding source terminals adapted to receive a biasing voltage POSV which, depending on the operation to be performed, can be equal to the supply voltage Vdd or higher, for example 12V in the case of the programming operation. The transistors N 2 and N 3 have the corresponding drain terminals connected to the drain terminals of the transistors P 2 and P 3 , respectively. The gate terminal of the transistor P 2 is connected to the drain terminal of the transistor P 3 and the gate terminal of the transistor P 3 is connected to the drain terminal of the transistor P 2 that is in turn connected to an output terminal connected to the voltage-shifted signal line LXHV 0 . The transistors N 2 and N 3 have the source terminals receiving the reference voltage GND. The gate terminal of the transistor N 3 is connected to the input terminal of the inverter 310 and receives a low-voltage signal (for example, equal to ground or to 3.3 V or 1.8 V, depending on the switching-on state of the signal) from the signal line LXLV 0 . The transistor N 2 has the gate terminal connected to the output terminal of the inverter 310 , thus receiving a signal LXLV 0# that is the logic complement of the signal LXLV 0 .
Furthermore, the connections of the body terminals of all the transistors are such that [their] the correct operation of the transistors is assured in any situation, and such that the PN junctions of the transistors are not forward biased.
When the signal line LXLV 0 is switched on, and the logic signal it carries is asserted to the high logic value, the signal line reaches the supply voltage Vdd, for example, 3.3 V or even 1.8 V; the inverter 310 provides as an output the complementary signal LXHV 0# at the low logic value (i.e., in terms of voltage, at ground GND). In such conditions, the transistor N 3 is kept turned on, while the transistor N 2 is kept turned off. The transistor N 2 is in series to the transistor P 2 , and, since no current can flow in the circuit branch formed by the transistors P 2 and N 2 (because the transistor N 2 is turned off), the transistor P 2 , turned on because the circuit node corresponding to its gate terminal is kept at ground by the transistor N 3 , brings the voltage of its drain terminal at the biasing voltage POSV. In such conditions, also the transistor P 3 is turned off, and then the transistor N 3 can actually keep its drain terminal (and then the voltage of the signal LXHV 0 ) at ground GND.
On the other hand, when the signal line LXLV 0 is not switched on, that is, it is at the low logic value (i.e., in terms of voltage, at ground GND), the drain voltage of the transistor P 3 and, then, the signal line LXHV 0 reaches the voltage POSV.
In this way, the elemental block booster 210 shifts the low input voltage on the signal line LXLV 0 to higher output voltage levels, which are adapted to correctly drive the CMOS inverter of the corresponding driving circuit by means of the shifted signal line LXHV 0 .
The voltage-shifter block 315 occupies a relatively wide integrated circuit area. In fact, while the transistors N 2 and N 3 are driven by the voltages provided by the signal lines LXLV 0 and LXLV 0 #, respectively, which are relatively low (i.e., of the order of the supply voltages Vdd), the transistors P 2 and P 3 are driven by the biasing voltage POSV that, in the case, for example, a programming operation is being performed, is of the order of the voltages Vin (for example, 12 V). Then, the driving voltage of the transistors P 2 and P 3 is quite a bit higher than the driving voltage of the transistors N 2 and N 3 . In order for the latch structure to be correctly moved towards the desired direction, so that the voltages at the drain terminals of the transistors P 2 and P 3 can be brought to the desired values (i.e., to POSV and GND), the n-channel transistors N 2 and N 3 need to be sized in such a way that the greater driving capability of the p-channel transistors P 2 and P 3 , due to the greater driving voltage across P 2 and P 3 can be opposed with a complementary opposing voltage.
The solution of the present invention according to the embodiment just described greatly reduces the area occupied by the level shifters inside the semiconductor material chip, where the memory device is integrated.
In fact, the structure of the row and column decoding and selection circuit, according to the solution of the present invention, provides, for all the sectors S 0 , . . . , S Ns-1 (or at least for groups of two or more sectors), a single group of level shifter blocks, shared by the various sectors. This permits a significant reduction in terms of area of the device, thanks to the plurality of elemental voltage booster blocks 210 common to all the sectors (or to groups of sectors), and the generated signals are used from time to time by the selected sector Si. On the contrary, a solution, in which each row decoder and selector 120 r 0 , . . . , 120 r Ns-1 receives the signals LXLV 0 , . . . , LXLV X-1 ; LYLV 0 , . . . , LYLV Y-1 ; PLV 0 , . . . , PLV P-1 ; and QLV 0 , . . . , QLV Q-1 and includes a respective voltage booster for shifting in voltage such pre-decoding signals, could require a substantial increase of the area of the device.
In particular, with respect to this last case, according to embodiments of the present invention, it is possible to obtain a significant reduction, up to one third, of the area occupied by the decoding and selection circuit inside the semiconductor material chip.
With reference to FIG. 4 , in connection with the exemplifying scheme of FIG. 2 , two generic gate voltage generators, in the example at issue GENG 0 and GENG 1 , and a generic supply voltage generator GENS 0 are shown, properly connected to the corresponding driving circuits WLD 0 and WLD 16 , in the example connected to the word lines WL 0 and WL 16 of two adjacent word line packets P 0 and P t .
Both the driving circuits WLD 0 and WLD 16 receive the supply voltage from the supply signal SP 0 and the gate voltages from the gate driving signals GP 0 and GP 1 provided by the supply voltage generator GENS 0 and by the two gate voltage generators GENG 0 and GENG 1 , respectively.
In particular, the gate voltage generator circuit GENG 0 comprises a NAND logic gate 410 having three input terminals and an output terminal connected to an input of a first inverter 415 , with a second inverter 420 in cascade there to whose output constitutes the driving gate signal GP 0 . The output terminal of the first inverter 415 makes available a complementary driving gate signal GP 0# .
The three input terminals of the NAND gate 410 of the generic gate voltage generator circuit are connected to corresponding signal lines belonging to the groups of lines PHV, LSHV and QHV. For example, the NAND gate 410 of the gate voltage generator GENG 0 receives in input the signal lines PHV 0 , QHV 0 and LSHV 0 , while the gate voltage generator GENG 1 receives in input the signal lines PHV 1 , QHV 1 and LSHV 0 .
The NAND gate 410 and the two inverters 415 and 420 are supplied by three biasing voltages POSV, PREDECS and DECS, which are supplied by three supply voltage lines, respectively, indicated in the following description by the same reference numeral. The biasing voltages POSV, PREDECS and DECS vary depending on the operations to be performed on the memory cells; for example, in the programming operation the voltage POSV assumes a relatively high value, for example 12V, while the voltages PREDECS and DECS are kept at ground. In the erasing operation, on the other hand, the voltages DECS and POSV assume relatively low values (for example, equal to −9 V and 0 V, respectively), while the voltage PREDECS remains at ground. The output of the inverter 420 of the gate voltage generator circuit GENG 0 constitutes the gate signal GP 0 that is provided to the corresponding driving circuit WLD 0 . The gate voltage generator circuit GENG 1 has a structure analogous to that of the gate voltage generator circuit GENG 0 .
The supply voltage generator circuit GENS 0 comprises a NAND logic gate 425 and, in cascade thereto, an inverter 430 . The NAND logic gate 425 has three input terminals, each one connected to corresponding signal lines LXHV 0 , LXHV 0 and LSHV 0 . The NAND gate 425 and the inverter 430 are supplied by the biasing voltages POSV, PREDECS and DECS. The output of the inverter 430 constitutes the supply voltage signal SP 0 , which is provided to the corresponding driving circuits WLD 0 and WLD 16 .
In the example shown in FIG. 4 , the NAND logic gates and the inverters are of CMOS type; however, this is not to be intended as a limitation of the present invention, and other logic families could be used.
The row driving circuits WLD 0 and WLD 16 (and in general each driving circuit WLD 0 , . . . , WLD 255 ) comprise a voltage pull-up p-channel MOSFET transistor P 1 0 and P 1 16 , respectively, connected in series to a voltage pull-down n-channel MOSFET transistor N 1 0 and N 1 16 , respectively, so as to faun a CMOS inverter, supplied by the biasing voltage DECS and by the supply signal SP 0 , which assume different values depending on the operation to be performed. For example, during the programming operation the biasing voltage DECS assumes a value equal to the reference voltage GND (i.e., ground) and the supply voltage of the inverter SP 0 is equal to a programming voltage (i.e., equal to about 12 V), while during an erasing operation the biasing voltage DECS assumes a low value (for example −9 V) and the supply signal SP 0 is typically kept at ground.
Both the transistors N 1 0 and P 1 0 have the gate terminal receiving the driving voltage supplied by the driving gate signal GP 0 provided by the corresponding gate voltage generator circuit and the drain terminals connected to the corresponding word line (i.e., WL 0 ). Similarly, the driving circuit WLD 16 has the transistors N 1 16 and P 1 16 that have the gate terminal receiving the driving voltage supplied by the driving signal GP 1 provided by the corresponding gate voltage generator circuit and the drain terminals connected to the word line WL 16 .
During the programming operation for a selected cell, the word line corresponding to the cell (in the example at issue, the word line WL 0 ) is supplied at a programming voltage (for example, equal to about 12 V). The remaining word lines (for example, the word line WL 16 ) of the sector are kept at the reference voltage GND.
For this purpose the signal lines LSHV 0 , LXHV 0 , LYHV 0 , PHV 0 , and QHV 0 are switched on at the high logic level (i.e., supplied at a biasing voltage POSV). In such a condition, the driving gate signal GP 0 is at the low logic level, corresponding to a voltage supplied by the line DECS (in the example at issue the reference voltage GND), and the supply signal SP 0 is at the high logic level, corresponding to a biasing voltage POSV that, in the case of the programming operation, is equal to a programming voltage and then, for example, equal to about 12 V. Thanks to this, the pull-up transistor P 1 0 of the driving circuit WLD 0 brings its drain terminal and, then, the word line WL 0 to a programming voltage (for example equal to about 12 V).
Simultaneously, the signal lines PHV 1 and QHV i are kept at the low logic level, corresponding to a voltage GND, thus bringing the driving gate signal GP 1 to the high logic level (corresponding to a programming voltage supplied by the supply voltage line POSV). In such conditions, the pull-down transistor N 1 16 of the driving circuit WLD 16 brings its drain terminal and, then, the word line WL 16 to the reference voltage GND (typically, ground). In this way, the word lines are biased at the voltages correct for the programming operation (in turn, the column decoder properly biases the bit lines).
Naturally, in order to satisfy contingent and specific requirements, a person skilled in the art may apply many modifications and alterations to the above-described solution. In particular, although the present invention has been described with a certain degree of details with reference to preferred embodiments thereof, it is apparent that various omissions, substitutions and changes in the form and in the details, as well as other embodiments, are possible.
For example, analogous considerations apply if the memory device has a different structure, or if it includes equivalent elements (for example, with multilevel memory cells).
Furthermore, although described with reference to a non-volatile electrically programmable memory device, and more particularly a flash memory, nothing prevents one from applying the solution of the invention in other memory devices, also not programmable, for example, in order to boost (with respect to the supply voltage of the memory device) the voltages applied to the word lines during a reading operation.
Furthermore, the number of memory sectors and/or the size of the memory sectors can be different.
Moreover, also the number of word lines included in each sector can vary.
Furthermore, although in the preceding description reference has been made to a row decoder and selector, nothing prevents one from applying the solution of the invention also to a column decoder and selector. In particular, a single column voltage booster common to all the sectors could be provided, or, at least, to two or more sectors.
Moreover, it is possible that a general variation of the proposed solution is applicable to the managing of negative signals during the erasing operations on the memory device.
Furthermore, as yet mentioned, instead of having a single voltage booster circuit for all the memory sectors, it is possible to have two or more booster circuits, each one associated with two or more respective memory sectors. | A memory device having a plurality of memory cells grouped in at least two memory sectors is disclosed. A first decoding circuit operable to receive address codes of the plurality of memory cells and to generate a plurality of decoding and selecting signals in response to the address codes. A plurality of second decoding circuits are coupled to the first decoding circuit and operable to generate driving signals for the memory cell address signal lines based at least in part on the plurality of decoding and selecting signals. A voltage shifting circuit is operable to generate a shift in the voltage of the plurality of decoding and selecting signals for generating a plurality of shifted voltage decoding and selecting signals and to provide the shifted decoding and selecting signals to the plurality of second decoding signals for generating the drive signals. | 6 |
This application is a continuation-in-part application of my copending application Ser. No. 312,892, filed Dec. 7, 1972, now abandoned.
The present invention concerns a method and a device for cleaning, cutting and drilling holes in various substances, and also for studying rapidly and in a comparative way the reaction and characteristics of several samples of substances subjected to erosion by drops, such as radomes, helicopter rotor blades and turbine blades.
The method which is the object of the invention consists essentially in the producing of a high-speed jet of liquid, divided into droplets before being scattered by high-frequency vibrations concentrated in a judiciously chosen place.
A device for implementing the method consists in using a chamber for putting the liquid under very high pressure, ended by an injector having a suitable form to obtain a fast and high-quality jet over a length equal to a certain number of times its diameter. The discharge supply flows into the chamber. An ultrasonic generator having a judicious shape enables a high-frequency field to be made to converge at a given point at the level of the origin of the jet producing the high-frequency vibration which divides the latter into droplets.
In a variation of an embodiment, the high-frequency vibration is produced at the level of the origin of the jet by means of a magnetostrictive element situated at that place.
The premature disintegration of the jet of droplets may be avoided by a concentric jet of air or by a gas having the same speed as the drops.
In order to apply the method to the studying of the reaction of a sample subjected to the impact of drops thus produced, the jet of air is directed towards the sample placed in a container in which a vacuum is produced in order to have only the vapor pressure of the liquid used for reducing considerably the aerodynamic braking effect.
The maximum efficiency of the jet corresponds to fragmentation lengths of the jet equal to the diameter of the output nozzle.
To obtain such fragmentation, for a given speed of the jet, the frequency of the pulses must be inversely proportional to the diameter of the output nozzle.
These and other features, objects and advantages of the present invention will become more readily apparent from a consideration of the included specification and drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial cross-sectional view of a device according to the invention;
FIG. 2 is an axial cross-sectional view of the device depicted in FIG. 1, arranged for studying a sample;
FIG. 3 is a variation of the embodiment of a device according to the invention;
FIG. 4 is an axial cross-sectional view of another variation of the device according to the invention, including a cylindrically shaped chamber with its interior wall through which the output orifice passes being perpendicular to the jet axis and an output orifice with outwardly diverging sides when seen in axial cross-section as depicted in the figure;
FIG. 5 is an axial cross-sectional view of yet another variation of the device according to the invention;
FIG. 6 is an axial cross-sectional view of the device in FIG. 4, arranged for studying a sample; and
FIG. 7 is an axial cross-sectional view of still another variation of the device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The device in FIG. 1 comprises a chamber 1 supplied with liquid under high pressure by a pump connected to the orifice 2, that chamber ending in an interchangeable injector 3 intended for providing a fast jet.
The orifice 2 of chamber 1 can be either a single inlet or plural inlets, but should be parallel to the longitudinal axis of the chamber as depicted in the figure in order to avoid turbulence in chamber 1 such as that caused by rotation of the liquid therein, and to enable proper control of a coherent jet of droplets. Orifice 2 being parallel to the longitudinal axis of chamber 1, avoids both rotation of liquid in the chamber and the production of an uncontrollable spiral jet of droplets of uncontrollable size which might otherwise immediately disintegrate.
An ultrasonic device 4 supplied by a high-frequency generator 5 supplies an ultrasonic field, whose frequency is chosen as a function of the dimension of the drops which are to be obtained and focusses that field at a point chosen close to the narrow portion of the injector.
The jet coming from the output orifice of the injector 3 in droplets 6 whose dimensions depend on the frequency of the generator 5 are thus divided.
For example, with a 1-mm injector nozzle diameter and an initial jet speed of 200 m/s, drops of 1 mm may be obtained with a frequency of 200 Kc/s.
The invention operates with the liquid in chamber 1 being under high pressure, the jet of droplets 6 emerging from the chamber with high velocity in the range of 100 meters/second at 750 psi in the chamber to 600 meters/second at 3000 psi in the chamber. It should be appreciated, therefore, that the pressures employed in the device are quite high considering, for example, that normal atmospheric pressure is approximately 14.7 psi.
This device enables cleaning, cutting, and drilling of various substances.
Premature disintegration of the jet may be avoided by a concentric jet of air or of a gas having the same speed as the drops.
FIG. 2 shows an adjunction to the device in FIG. 1, enabling the studying of the reaction of diverse substances under the effect of the impact produced by high-speed droplets produced by the device according to the invention.
A sample 7 to be studied is placed in the test container 8 arranged in the extension of the chamber 1. It is borne by the plate 9 driven by the motor 10 whose shaft, which is eccentric in relation to the axis of the injector, makes it possible to define accurately a ring of impacts of the droplets. The discharging of the liquid is ensured by the tube 11. The test container 8 is put under a partial vacuum by means of a pipe 12 connected to an appropriate vacuum pumping arrangement.
Test container 8 is preferably used when high-speed droplets with a velocity in the neighborhood of 200 meters/second and above are produced. Such high speed droplets emerge into evacuated container 8 in order to avoid disintegration of the jet.
The variation in FIG. 3 shows a device comprising a chamber 1 supplied with liquid under high pressure by a pump, connected to the orifice 2, that chamber ending in an interchangeable injector 3 intended for providing a fast jet, that injector being provided, at its output 13, with a magnetostrictive element 14 comprising electrodes 15 and 16 connected to a high-frequency pulse generator 17, which thus sets the magnetostrictive element vibrating.
That arrangement makes it possible to divide the jet which comes from the orifice 13 in droplets 6 whose dimensions depend on the frequency of the generator 17.
FIG. 4 depicts an embodiment of the invention in which chamber 1 is of cylindrical shape, the longitudinal axis of the cylinder being parallel to and in line with both orifice 2 and the jet of droplets 6.
Since the invention provides drops having a velocity in the range of 100 meters/second at 750 psi to 600 meters/second at 3000 psi, it has been determined that to avoid turbulence which would disintegrte the jet and to provide proper control of both the size and velocity of the jet of droplets, the output orifice of chamber 1 and the chamber should take the shape depicted in FIG. 4.
As illustrated in FIG. 4, the chamber is cylndrically shaped. Its interior wall through which the output orifice passes is perpendicular to the jet axis. Each of the walls of the chamber, including the vertical inside wall through which the output orifice passes, is of sufficient thickness to withstand the high pressures existent within the chamber, these high pressures being in the neighborhood of 750 psi and greater. The output orifice is thin-lipped and has outwardly diverging sides when seen in axial cross-section as depicted in the figure. The output orifice forms a reverse taper toward the exterior side of the chamber such that it is narrower at the interior side of the wall through which it passes than at the exterior side of the injector, as depicted in the figure.
An output orifice taking the particular shape depicted in FIG. 4 enables the device to avoid any undesirable turbulent action which might otherwise be caused by the orifice wall. Additionally, this particular output orifice shape permits a suitable distribution of velocity in the interior of the jet. In order to obtain the thin-lip of the output orifice, the orifice is outwardly tapered toward the exterior of the chamber, as previously described.
In the embodiment depicted in FIG. 4, in order to provide a jet of droplets having velocity in the neighborhood of 100 meters/second, for example, while maintaining in low liquid velocity within the chamber to prevent undesirable turbulence, the diameter of the chamber can be 20 mm. To provide a jet of droplets having velocity in the range of 100 meters/second to 600 meters/second, for example, and still maintain low liquid velocity within the chamber to prevent undesirable turbulence, the diameter of the chamber can be 300 mm. The length of the chamber for these various values would fall in the range of 80 mm to 300 mm.
The relationships between the diameter of the nozzle, the velocity of the jet and the frequency of the vibration can be expressed by the formula: ##EQU1## where N is the frequency of the vibrations in Khz, V is the velocity of the jet of droplets in meters/second, and φ is the diameter of the nozzle in millimeters.
In the embodiment of the invention depicted in FIG. 4, just as in the FIG. 1 embodiment, orifice 2 of chamber 1 can be either a single inlet or plural inlets, but should be parallel to the longitudinal axis of the chamber as depicted in the figure in order to avoid turbulence in the chamber such as that caused by rotation of the liquid therein, and to enable proper control of a coherent jet of droplets.
FIG. 5 illustrates apparatus which insures the avoidance of premature disintegration of the jet of droplets by providing a concentric jet of air or gas A surrounding the drops which has the same high velocity as that of the drops. Jet A is formed by introducing air or gas into chamber C of circular shape, for example, via pipe B. Chamber C has an outlet D through which the jet A of air or gas surrounding the drops 6 is forced to move axially and outwardly at the same high velocity as the drops 6 in order to protect the drops 6 from premature disintegration.
Although the apparatus for protecting the jet of droplets from premature disintegration has specifically been illustrated with an embodiment of the invention as depicted in FIG. 4, the apparatus for protecting the drops can also be used with each of the other disclosed embodiments to obtain the same beneficial results.
Since the device is often used to produce a jet of droplets having velocity in the neighborhood of 200 meters/second and above, vacuum chamber 8 illustrated in FIG. 6 is provided to avoid disintegration of the jet. FIG. 6 shows the invention including test container 8 disposed adjacent injector 3 where a cylindrical chamber 1 having its interior wall through which the output orifice passes being perpendicular to the jet axis and thin-lipped outlet orifice forming a reverse taper toward the exterior side of the chamber are included; however, test container 8 can be used with each of the other disclosed embodiments of the invention in order to obtain similar beneficial results.
FIG. 7 depicts another embodiment of the device which permits the jet of droplets 6 emitted from orifice 13 to have dimensions dependent upon the frequency of generator 17. In this embodiment, magnetostrictive element 14 is surrounded by electric coil 18 which is connected through electrodes 15 and 16 to high frequency generator 17 for vibrating magnetostrictive element 14. Chamber 1 can take a cylindrical shape and have its interior wall through which the droplets pass being perpendicular to the axis of the jet as illustrated, and orifice 13 as depicted in the figure can be thin-lipped and reverse tapered toward the exterior of the chamber.
While I have shown and described only several embodiments in accordance with the present invention, it is understood that the same is not limited thereof but is susceptible of numerous changes and modifications as known to those skilled in the art. For example, although chamber 1 was depicted as being of cylindrical shape in only several embodiments of the invention, the chamber in the other embodiments could also assume the same shape. Similarly, although the outlet orifice has only been shown in several embodiments as forming a reverse taper toward the exterior side of the chamber such that it is narrower at the interior side of the wall through which it passes than at the exterior side of the injector, the orifice in the other embodiments could also assume the same shape to obtain the same beneficial results. Similar comments apply to the disclosed apparatus providing a concentric jet of air or gas surrounding the drops and the vacuum chamber 8. I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modificatins as are encompassed by the scope of the appended claims. | A method and apparatus for producing a very fast succession of identical well-defined drops, driven at very high speed, in which a jet of liquid which is divided into droplets by high-frequency vibration is produced at very high speed. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a placement and routing method for clock distribution circuits, a clock distribution circuit manufacturing method, a semiconductor device manufacturing method, a clock distribution circuit and a semiconductor device, and particularly to an improvement for precisely and easily adjusting the clock skew.
2. Description of the Background Art
In an LSI (Large-Scale Integrated Circuit), it is not easy to supply a clock at the same time to all sequential elements (e.g. flip-flops) included in the circuitry without causing time differences in arrival of the clock among the sequential elements receiving it. These time differences are called clock skew. Particularly, operating LSIs at high speed requires highly precise clock skew control in order to reduce the clock skew to a very small value.
Factors contributing to the clock skew include non-uniformity of positions of the sequential elements and non-uniformity of the interconnection capacitances due to differences in interconnection length among adjacent interconnections or differences in intersection ratio among inter-layer interconnections. Therefore, in order to design a clock distribution circuit with a small clock skew, it is desirable to first conduct the placement and routing of the circuitry which is supplied with the clock (the circuitry is referred to as load circuit in this specification) and then design the clock distribution circuit. However, since the clock distribution circuit is distributed over the entire area of the semiconductor chip, there is a basic contradiction that the placement and routing cannot be finally settled until the clock distribution circuit has been designed.
Known conventional layout design methods for clock distribution circuit include the technique described in Japanese Patent Application Laid-Open No. 9-269847 (1997). In this conventional technique, two or more driver elements having different characteristics are placed in each of the positions of the driver elements in the clock distribution circuit and the clock skew is controlled by selecting one of the two or the more.
FIG. 10 is a circuit diagram showing the structure of a clock distribution circuit before the clock skew has been adjusted by this conventional technique. In this clock distribution circuit, the input clock CLK is distributed through the predriver circuit 1 having cascade-connected driver elements 4 a , 4 b and 4 c to the main driver circuit 2 having driver elements 4 d to 4 i . The main driver circuit 2 supplies the clock to the load circuit 3 having sequential elements 7 a to 7 g and clock interconnections connecting the main driver circuit 2 and the sequential elements 7 a to 7 g . The predriver circuit 1 in the first stage and the main driver circuit 2 in the final stage are cascade-connected.
FIG. 11 is a circuit diagram showing the structure of the clock distribution circuit obtained after the clock skew adjustment. In the example shown in FIG. 11, in order to adjust the clock skew, the driver elements 4 d and 4 e belonging to the main driver circuit 2 have been replaced by driver elements 5 a and 5 b having a larger driving capability and a larger input capacitance and the driver elements 4 g and 4 h have been replaced by driver elements 6 a and 6 b having a smaller driving capability and a smaller input capacitance.
FIG. 12 is a flowchart showing the procedure of placement and routing method for the above-described clock distribution circuit according to the conventional technique. In this method, the clock distribution circuit is designed first (S 1 ) and the placement and routing of the entire chip including the clock distribution circuit follows (S 2 ). In the step S 2 , the placement and routing of the clock distribution circuit is a temporary one. Next, the clock skew value is calculated (S 3 ) and then whether the calculated clock skew exceeds a target value is checked (S 4 ).
If the step S 4 decides that the clock skew exceeds the target value, some of the driver elements are replaced with other driver elements having different driving capabilities and different input capacitances to adjust the clock skew (S 5 ). Then the placement and routing is corrected as required by the replacement of the driver elements (S 6 ) and then whether the clock skew exceeds the target value is checked again (S 3 , S 4 ). The process ends if the step S 4 shows that the clock skew has become equal to or smaller than the target value. In this way, the conventional technique adjusts the clock skew through replacements between driver elements having different driving capabilities and different input capacitances.
In the conventional technique, since a driver element is replaced by another driver element having a different input capacitance, the circuit characteristic varies seen from the preceding circuit. As a result, the replacement of the driver elements may require correction of the preceding circuit. Furthermore, the driver elements are generally exchanged between elements having their input pins and output pins laid out in different positions, so that replacing the driver elements requires correction of the interconnections. Thus, the placement and routing may have to be largely corrected every time a driver element is replaced, which increases the time required for the design. Moreover, correcting the placement and routing changes factors contributing to the clock skew, which makes it difficult to precisely adjust the clock skew.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above-described problems of the conventional technique, and an object of the present invention is to obtain a placement and routing method for a clock distribution circuit, a clock distribution circuit manufacturing method, a semiconductor device manufacturing method, a clock distribution circuit and a semiconductor device which allow the clock skew to be adjusted highly precisely and easily.
A first aspect of the present invention is directed to a placement and routing method for a clock distribution circuit which receives a clock and supplies the clock to a load circuit. According to the first aspect, the method comprises the steps of: (a) temporarily placing and routing a group of elements having a common input capacitance to form the clock distribution circuit; and (b) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of an element belonging to the group of elements among a plurality of elements having a common input capacitance and selected from a group consisting of a plurality of driver elements having different driving capabilities, a driver element having an opened output pin and a capacitance element interposed between an input pin and a stable potential line.
Preferably, according to a second aspect, in the placement and routing method for a clock distribution circuit, the step (b) makes the selective replacement of an element belonging to the group of elements between a first driver element and a second driver element identical to the first driver element and having an opened output pin until the evaluated value of clock skew becomes equal to or smaller than the target value.
Preferably, according to a third aspect, in the placement and routing method for a clock distribution circuit, the step (b) makes the selective replacement of an element belonging to the element group between a driver element and a capacitance element sharing a common input capacitance with the driver element and interposed between an input pin and a stable potential line until the evaluated value of clock skew becomes equal to or smaller than the target value.
Preferably, according to a fourth aspect, in the placement and routing method for a clock distribution circuit, the step (b) makes the selective replacement of an element belonging to the element group among a plurality of driver elements having different driving capabilities and a common input capacitance and having their input pins placed in equivalent positions and their output pins placed in equivalent positions until the evaluated value of clock skew becomes equal to or smaller than the target value.
A fifth aspect is directed to a placement and routing method for a clock distribution circuit which receives a clock and supplies the clock to a load circuit. According to the fifth aspect, the method comprises the steps of: (a) temporarily placing and routing a group of driver elements having their input pins placed in equivalent positions and their output pins placed in equivalent positions to form the clock distribution circuit; and (b) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of a driver element belonging to the group of driver elements among a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and output pins placed in equivalent positions.
A sixth aspect is directed to a method of manufacturing a clock distribution circuit which receives a clock and supplies the clock to a load circuit. According to the sixth aspect, the clock distribution circuit manufacturing method comprises the steps of: (A) performing a placement and routing of the clock distribution circuit comprising the steps of (A-1) temporarily placing and routing a group of elements having a common input capacitance to form the clock distribution circuit, and (A-2) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of an element belonging to the group of elements among a plurality of elements having a common input capacitance and selected from a group consisting of a plurality of driver elements having different driving capabilities, a driver element having an opened output pin and a capacitance element interposed between an input pin and a stable potential line; and (B) fabricating the clock distribution circuit obtained through the step of placement and routing in a semiconductor substrate.
Also, a method of manufacturing a clock distribution circuit which receives a clock and supplies the clock to a load circuit comprises the steps of: (A) performing a placement and routing of the clock distribution circuit comprising the steps of (A-1) temporarily placing and routing a group of driver elements having their input pins placed in equivalent positions and their output pins placed in equivalent positions to form the clock distribution circuit, and (A-2) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of a driver element belonging to the group of driver elements among a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions; and (B) fabricating the clock distribution circuit obtained through the step of placement and routing in a semiconductor substrate.
According to a seventh aspect, a method of manufacturing a semiconductor device comprises the steps of: (A) performing a placement and routing of a clock distribution circuit which receives a clock and supplies the clock to a load circuit comprising the steps of (A-1) temporarily placing and routing a group of elements having a common input capacitance to form the clock distribution circuit, and (A-2) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of an element belonging to the group of elements among a plurality of elements having a common input capacitance and selected from a group consisting of a plurality of driver elements having different driving capabilities, a driver element having an opened output pin and a capacitance element interposed between an input pin and a stable potential line; and (B) fabricating, in a semiconductor substrate, the clock distribution circuit obtained through the step of placement and routing and the load circuit which is supplied with the clock from the clock distribution circuit.
Also, a method of manufacturing a semiconductor device comprises the steps of: (A) performing a placement and routing of a clock distribution circuit which receives a clock and supplies the clock to a load circuit comprising the steps of (A-1) temporarily placing and routing a group of driver elements having their input pins placed in equivalent positions and their output pins placed in equivalent positions to form the clock distribution circuit, and (A-2) until an evaluated value of clock skew becomes equal to or smaller than a target value, making a selective replacement of a driver element belonging to the group of driver elements among a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions; and (B) fabricating, in a semiconductor substrate, the clock distribution circuit obtained through the step of placement and routing and the load circuit which is supplied with the clock from the clock distribution circuit.
According to an eighth aspect, a clock distribution circuit which receives a clock and supplies the clock to a load circuit comprises a plurality of elements having a common input capacitance and selected from a group consisting of a plurality of driver elements having different driving capabilities, a driver element having an opened output pin and a capacitance element interposed between an input pin and a stable potential line.
Preferably, according to a ninth aspect, in the clock distribution circuit, the plurality of elements comprise a first driver element and a second driver element identical to the first driver element and having an opened output pin.
Preferably, according to a tenth aspect, in the clock distribution circuit, the plurality of elements comprise a driver element and a capacitance element sharing a common input capacitance with said driver element and interposed between an input pin and a stable potential line.
Preferably, according to an eleventh aspect, in the clock distribution circuit, the plurality of elements comprise a plurality of driver elements having different driving capabilities and a common input capacitance and having their input pins placed in equivalent positions and their output pins placed in equivalent positions.
According to a twelfth aspect, a clock distribution circuit which receives a clock and supplies the clock to a load circuit comprises a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions.
According to a thirteenth aspect, a semiconductor device comprises: (A) a clock distribution circuit which receives a clock, the clock distribution circuit comprising a plurality of elements having a common input capacitance and selected from a group consisting of a plurality of driver elements having different driving capabilities, a driver element having an opened output pin, and a capacitance element interposed between an input pin and a stable potential line; and (B) a load circuit which is supplied with the clock from the clock distribution circuit.
Also, a semiconductor device comprises: (A) a clock distribution circuit which receives a clock, the clock distribution circuit comprising a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions; and (B) a load circuit which is supplied with the clock from the clock distribution circuit.
According to the method of the first aspect, the clock skew is adjusted through a replacement among elements having different driving capabilities and a common input capacitance. Accordingly the replacement of elements does not affect the preceding circuit and the clock skew can be adjusted easily and precisely.
According to the method of the second aspect, the clock skew is adjusted through a replacement between a first driver element and a second driver element identical to the first driver element and having an opened output pin, in other words, by selectively disconnecting or connecting the interconnection connected to the output pin of the driver element. Accordingly there is little need to change the placement and routing and the clock skew can be adjusted easily in a short time.
According to the method of the third aspect, the clock skew is adjusted through a replacement between a driver element and a capacitance element having a common input capacitance. Accordingly there is little need to change the placement and routing and the clock skew can be easily adjusted in a short time. Furthermore, using a capacitance element free from short-circuit current as an element not contributing to the transfer of clock reduces the current dissipation.
According to the method of the fourth aspect, the clock skew is adjusted through a replacement among a plurality of driver elements having different driving capabilities and a common input capacitance and having their input pins placed in equivalent positions and their output pins placed in equivalent positions. Accordingly there is little need for changing the placement and routing and the clock skew can be easily and more precisely adjusted in a shorter time. Further, this method can be applied to a wide range of clock distribution circuits including those of the clock tree type.
According to the method of the fifth aspect, the clock skew is adjusted through a replacement among a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions. Accordingly there is little need for changing the placement and routing and the clock skew can be easily adjusted in a shorter time. Further, this method can be applied to a wide range of clock distribution circuits including those of the clock tree type.
According to the method of the sixth aspect, a clock distribution circuit is manufactured by fabricating a clock distribution circuit obtained through the placement and routing of the invention in a semiconductor substrate. A clock distribution circuit with precisely adjusted clock skew can thus be obtained.
According to the method of the seventh aspect, a semiconductor device is manufactured by fabricating, in a semiconductor substrate, a clock distribution circuit obtained through the placement and routing of the invention and a load circuit supplied with a clock from it. A semiconductor device with precisely adjusted clock skew can thus be obtained.
A plurality of elements having different driving capabilities and a common input capacitance are mixed in the device of the eighth aspect. This can realize precisely adjusted clock skew.
A first driver element and a second driver element identical to the first driver element and having an opened output pin are mixed in the device of the ninth aspect. This can realize precisely adjusted clock skew with a simple structure.
A driver element and a capacitance element having a common input capacitance are mixed in the device of the tenth aspect. This can realize precisely adjusted clock skew with a simple structure.
A plurality of driver elements having different driving capabilities and a common input capacitance and having their input pins placed in equivalent positions and their output pins placed in equivalent positions are mixed in the device of the eleventh aspect. This can realize more precisely adjusted clock skew.
A plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions are mixed in the device of the twelfth aspect. This can realize precisely adjusted clock skew.
The device of the thirteenth aspect has a clock distribution circuit of the invention and a load circuit which is supplied with a clock from it. This can realize a semiconductor device with precisely adjusted clock skew.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart showing a placement and routing method according to a first preferred embodiment.
FIG. 2 is a diagram used to explain the placement and routing method of the first preferred embodiment.
FIG. 3 is a flowchart showing another example of the placement and routing method of the first preferred embodiment.
FIG. 4 is a flowchart showing a method for manufacturing a semiconductor device according to the first preferred embodiment.
FIG. 5 is a flowchart showing a placement and routing method according to a second preferred embodiment.
FIG. 6 is a diagram used to explain the placement and routing method of the second preferred embodiment.
FIG. 7 is a flowchart showing a placement and routing method according to a third preferred embodiment.
FIG. 8 is a diagram used to explain the placement and routing method of the third preferred embodiment.
FIG. 9 is a diagram used to explain a placement and routing method according to a fourth preferred embodiment.
FIGS. 10 and 11 are diagrams used to explain a conventional placement and routing method.
FIG. 12 is a flowchart showing the conventional placement and routing method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Preferred Embodiment
FIG. 1 is a flowchart showing the procedure of a placement and routing method for clock distribution circuits according to a first preferred embodiment. In this method, the clock distribution circuit is designed first (S 1 ) and the placement and routing of the entire chip including the clock distribution circuit follows (S 2 ). In the step S 2 , the placement and routing of the clock distribution circuit is a temporary one. The clock distribution circuit in this stage is the same as that shown in FIG. 10, for example. In FIG. 10, the clock distribution circuit adopts the en bloc driving system and all driver elements belonging to the main driver circuit 2 have their outputs short-circuited.
Next, the clock skew value is calculated (i.e. evaluated; S 3 ) and whether the calculated clock skew (i.e. evaluated value) exceeds a target value is checked (S 4 ). When the step S 4 decides that the clock skew exceeds the target value, then the outputs of some driver elements are selectively disconnected to adjust the clock skew (S 51 ). More specifically, considering non-uniformity of elements in the load circuit, e.g. a storage device, or non-uniformity of the interconnection capacitances, etc., the outputs of driver elements having unnecessarily large driving capability are disconnected to remove unwanted driving capability in order to adjust the clock skew.
Subsequently, it is checked again whether the clock skew exceeds the target value (S 3 , S 4 ). The process ends when the step S 4 shows that the clock skew has become equal to or smaller than the target value. FIG. 2 is a circuit diagram showing an example of the structure of the clock distribution circuit obtained as a result of this process. In FIG. 2, the outputs of the driver elements 4 g and 4 h belonging to the main driver circuit 2 are disconnected.
Referring to FIG. 1 again, the outputs of driver elements which were once disconnected may be connected again in the step S 51 . Further, in the step S 2 , a clock distribution circuit in which some of the driver elements are disconnected, e.g., the clock distribution circuit shown in FIG. 2, may be used in place of the clock distribution circuit of FIG. 10 as a clock distribution circuit obtained after the temporary placement and routing.
Disconnecting the output of a driver element is to remove or cut the interconnection connected to the output pin of the driver element. At the same time, this is equivalent to a replacement of the driver element with a driver element having the same structure and configuration but having an opened output pin. Thus, the process of the step S 51 is equivalent to a replacement between driver elements and other driver elements having the same structure and configuration as those driver elements but having their output pins opened.
When the outputs of some driver elements get disconnected or connected, their input capacitance remains unchanged before and after the step S 51 . Therefore, when the driver elements whose outputs are disconnected or connected belong to the main driver circuit 2 of FIG. 2, for example, the input capacitance distribution of the main driver circuit 2 remains unchanged seen from the predriver circuit 1 . Hence the process of the step S 51 does not require changing a circuit, e.g. the predriver circuit 1 , which precedes the driver elements processed in the step S 51 . In the example of FIG. 2, driver elements other than those belonging to the main driver circuit 2 may be processed in the step S 51 ; the driver elements belonging to the predriver circuit 1 may be the targets for the processing.
Furthermore, there is little need to change the interconnections of the clock distribution circuit, since the step S 51 just disconnects or connects driver elements, in other words, since it just makes a replacement between driver elements having connected output pins and identical driver elements having opened output pins.
As described above, the method of this preferred embodiment does not require changing the circuit which precedes the driver elements whose outputs have been disconnected or connected. Furthermore, there is little need to change the clock interconnections (i.e. the interconnections belonging to the clock distributions circuit). Accordingly, the placement and routing of the clock distribution circuit can be easily achieved in a shorter time. Moreover, placement and routing which will affect the clock skew is hardly changed, so that the clock skew can be adjusted very precisely through a reduced number of trials; that is to say, the clock skew can be adjusted in a shorter time by repeating the loop of the steps S 3 , S 4 and S 51 a smaller number of times.
As already stated about the conventional technique, it is originally desirable to perform the placement and routing of the load circuit before designing the clock distribution circuit. Accordingly the procedure shown by the flowchart of FIG. 3 may be used in place of the procedure shown in FIG. 1; in the flowchart of FIG. 3, the placement of the load circuit (S 21 ) precedes the design of the clock distribution circuit (S 1 ), and which is followed by the placement and routing of the clock distribution circuit and the routing of the load circuit (S 22 ).
The processing shown in FIG. 1 or FIG. 3 is conducted on a computer, and then a semiconductor process completes a semiconductor device as a product, reflecting the result of the processing of FIG. 1 or FIG. 3 on a semiconductor substrate. FIG. 4 is a flowchart showing the outline of this procedure. In manufacture of the semiconductor device, the load circuit is designed first (S 100 ) and the process shown in FIG. 1 or FIG. 3 follows (S 101 ). Next the semiconductor process is performed to apply various processings to the semiconductor substrate (S 102 ).
In this semiconductor process, a clock distribution circuit obtained through the placement and routing by the process of FIG. 1 or FIG. 3 and a load circuit supplied with a clock from this clock distribution circuit are fabricated in a semiconductor substrate. A semiconductor device with precisely adjusted clock skew can thus be obtained. The semiconductor substrate is not limited to a bulk semiconductor substrate but it may be an SOI substrate, for example.
Second Preferred Embodiment
FIG. 5 is a flowchart showing the procedure of a placement and routing method for clock distribution circuits according to a second preferred embodiment. This method characteristically differs from the method shown in FIG. 1 in that, when the step S 4 decides that the clock skew exceeds the target value, some of the driver elements are replaced by capacitance elements having the same input capacitance as the driver elements to adjust the clock skew (S 52 ).
FIG. 6 is a circuit diagram showing an example of the structure of a clock distribution circuit obtained as a result of the process of FIG. 5; in this example, the circuit shown in FIG. 10 is used as a clock distribution circuit obtained after the temporary placement and routing (S 2 ). In FIG. 6, the two driver elements 4 g and 4 h belonging to the main driver circuit 2 have been replaced by capacitance elements 43 a and 43 b . The capacitance elements 43 a and 43 b substituted for the driver elements 4 g and 4 h are interposed between a stable potential line and the input pins which are used when driver elements are placed there. The stable potential line is an interconnection which holds a constant potential difference with respect to power-supply potential lines, or it may be a power-supply potential line itself; FIG. 6 shows a ground potential line, one of the power-supply potential lines, as an example.
In the step S 52 , a capacitance element once substituted may be replaced by a driver element again. Further, in the step S 2 , the clock distribution circuit obtained through the temporary placement and routing may be a clock distribution circuit in which some of the driver elements have been replaced by capacitance elements, e.g. the clock distribution circuit shown in FIG. 6, in place of the clock distribution circuit of FIG. 10 . Accordingly, the step S 52 can be generally represented as a process of making a selective replacement of elements belonging to the clock distribution circuit between driver elements and capacitance elements interposed between input pins and a stable potential line, the driver elements and capacitance elements having a common input capacitance.
As stated about the step S 51 in the first preferred embodiment, the input capacitance of the exchanged elements remains unchanged before and after the step S 52 . Accordingly, when elements belonging to the main driver circuit 2 of FIG. 6 are replaced, for example, the input capacitance distribution of the main driver circuit 2 remains unchanged seen from the predriver circuit 1 . Further, there is little need to change the interconnections of the clock distribution circuit since the step S 52 only makes a replacement between driver elements and capacitance elements. In the example of FIG. 6, elements other than those belonging to the main driver circuit 2 may be replaced in the step S 52 ; elements belonging to the predriver circuit 1 may be replaced.
Thus, according to the method of this preferred embodiment, there is no need to change the circuit which precedes the replaced elements, and there is little need to change the clock interconnections, so that the placement and routing of the clock distribution circuit can be easily achieved in a short time. Moreover, the placement and routing which will affect the clock skew is hardly changed, so that the clock skew can be adjusted very precisely with a reduced number of trials; that is, the number of repetitions of the loop of the steps S 3 , S 4 and S 52 can be reduced to shorten the time required for the adjustment of the clock skew. In addition, the capacitance elements, unlike the driver elements, are free from short-circuit current, and therefore the current dissipation can be reduced as compared with the clock distribution circuit of the first preferred embodiment.
Needless to say, the processes of the steps S 1 and S 2 of FIG. 5 can be replaced by the steps S 21 , S 1 and S 22 shown in FIG. 3 in the first preferred embodiment. Further, a semiconductor device having a clock distribution circuit reflecting the result of the process of FIG. 5 and a load circuit supplied with a clock from it can be manufactured by performing the process of FIG. 5 as the process of the step S 101 shown in FIG. 4 in the first preferred embodiment.
Third Preferred Embodiment
FIG. 7 is a flowchart showing the procedure of a placement and routing method for clock distribution circuits according to a third preferred embodiment. This method characteristically differs from the method shown in FIG. 1 in that, when the step S 4 decides that the clock skew exceeds the target value, some driver elements are replaced by other driver elements having different driving capabilities and having their input pins placed in equivalent layout positions and their output pins placed in equivalent layout positions, so as to adjust the clock skew (S 53 ).
FIG. 8 is a circuit diagram showing an example of the structure of a clock distribution circuit obtained as a result of the process of FIG. 7; the circuit shown in FIG. 10 is used as the clock distribution circuit obtained through the temporary placement and routing (S 2 ). In FIG. 8, the two driver elements 4 d and 4 e belonging to the main driver circuit 2 have been replaced by other driver elements 41 a and 41 b having a higher driving capability and other two driver elements 4 g and 4 h have been replaced by other driver elements 42 a and 42 b having a lower driving capability.
In the step S 53 , a driver element once substituted may be replaced by the original driver element again. Further, in the step S 2 , the clock distribution circuit obtained after the temporary placement and routing may be a clock distribution circuit in which some of the driver elements have been replaced by other driver elements, e.g. the clock distribution circuit shown in FIG. 8, in place of the clock distribution circuit of FIG. 10 . Thus, the step S 53 can be generally represented as a step of making a selective replacement of elements belonging to the clock distribution circuit between a plurality of driver elements having different driving capabilities and a common input capacitance and having their input pins placed in equivalent positions and their output pins placed in equivalent positions.
As stated about the step S 51 in the first preferred embodiment, the input capacitance of the exchanged elements remains unchanged before and after the step S 53 . Accordingly, when elements belonging to the main driver circuit 2 of FIG. 8 are replaced, for example, the input capacitance distribution of the main driver circuit 2 remains unchanged seen from the predriver circuit 1 . Further, there is no need to change the interconnections of the clock distribution circuit since the step S 53 only makes a replacement between driver elements between which input pins and output pins are laid out in common positions. In the example of FIG. 8, elements other than those belonging to the main driver circuit 2 may be replaced in the step S 53 ; elements belonging to the predriver circuit 1 may be replaced.
As described above, the method of this preferred embodiment requires neither changing the circuit which precedes the replaced elements nor changing the clock interconnections, so that the placement and routing of the clock distribution circuit can be easily achieved in a short time. Moreover, placement and routing which will affect the clock skew is hardly changed, so that the clock skew can be adjusted very precisely with a reduced number of trials; that is, the number of repetitions of the loop of the steps S 3 , S 4 and S 53 can be reduced to shorten the time required for the adjustment of the clock skew.
Further, making a replacement between driver elements having various driving capabilities allows finer adjustment of the clock skew. That is, the clock skew can be adjusted more precisely.
Needless to say, the processes of the steps S 1 and S 2 of FIG. 7 can be replaced by the steps S 21 , S 1 and S 22 shown in FIG. 3 in the first preferred embodiment. Further, a semiconductor device having a clock distribution circuit reflecting the result of the process of FIG. 7 and a load circuit supplied with a clock from it can be manufactured by performing the process of FIG. 7 as the process of the step S 101 shown in FIG. 4 in the first preferred embodiment.
Further, in the step S 53 , the selective replacement of elements belonging to the clock distribution circuit may be made between a plurality of driver elements having different driving capabilities and a common input capacitance. Specifically, the input and output pins may be laid out in different positions between driver element exchanged for each other. This still provides the advantage resulting from the fact that the exchanged driver elements have a common input capacitance.
Similarly, in the step S 53 , the selective replacement of elements belonging to the clock distribution circuit may be made between a plurality of driver elements having different driving capabilities and having their input pins placed in equivalent positions and their output pins placed in equivalent positions. That is to say, the input capacitance may differ between exchanged driver elements. This still provides the advantage resulting from the fact that the input pins and output pins are laid out in common positions between the exchanged driver elements.
Fourth Preferred Embodiment
The method shown in FIG. 7 in the third preferred embodiment is applicable not only to clock distribution circuits based on the en bloc driving system as shown in FIGS. 10 and FIG. 8 but also to clock distribution circuits based on the clock-tree system. FIG. 9 is a circuit diagram showing an example of structure of a clock distribution circuit obtained after the process shown in FIG. 7; in the drawing, a clock distribution circuit based on the clock-tree system is adopted as the clock distribution circuit obtained through the temporary placement and routing of FIG. 7 (S 2 ).
In the clock distribution circuit shown in FIG. 9, a plurality of driver elements are cascade-connected in tree form and the elements belonging to the load circuit 3 are arranged so that the driver elements belonging to the main driver circuit portion 2 are uniformly loaded. In the example of FIG. 9, as a result of the process of FIG. 7, one driver element in the main driver circuit 2 has been replaced by another driver element 41 a having a higher driving capability and another driver element has been replaced by another driver element 42 a having a lower driving capability.
Needless to say, also in applications to clock-tree type clock distribution circuits, the processes of the steps S 1 and S 2 of FIG. 7 can be replaced by the steps S 21 , S 1 and S 22 shown in FIG. 3 in the first preferred embodiment. Further, a semiconductor device having a clock-tree type clock distribution circuit reflecting the result of the process of FIG. 7 and a load circuit supplied with a clock from it can be manufactured by performing the process of FIG. 7 as the process of the step S 101 shown in FIG. 4 in the first preferred embodiment.
Further, also in applications to clock-tree type clock distribution circuits, the step S 53 can make a selective replacement of elements belonging to the clock distribution circuit between a plurality of driver elements having different driving capabilities and a common input capacitance, or between a plurality of driver elements having different driving capabilities and having input pins placed in equivalent positions and output pins placed in equivalent positions.
Modifications
The steps S 51 to S 53 in the first to fourth preferred embodiments may be simultaneously or selectively performed in the placement and routing of a single clock distribution circuit. Specifically, in general, while repeating the step S 51 of FIG. 1 or FIG. 3, one of the steps S 51 to S 53 may be selectively performed in place of the step S 51 , or the steps S 51 to S 53 may be performed at the same time. Performing the steps at the same time means replacing a driver element with a capacitance element while replacing another driver element with a driver element having a higher driving capability, for example.
Such a process like a further generalized version of the steps S 51 to S 53 can be represented as a process of making a selective replacement of elements belonging to a clock distribution circuit between a plurality of elements having a common input capacitance and selected from the group consisting of a plurality of driver elements having different driving capabilities, driver elements having opened output pins, and capacitance elements interposed between input pins and a stable potential line. While such a general process is advantageous in that the selection can be made in a wide range, the methods of the first to fourth preferred embodiments are advantageous in that the processing is simpler and therefore the clock skew can be adjusted more easily in a shorter time.
While the invention has been described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is understood that numerous other modifications and variations can be devised without departing from the scope of the invention. | An object of the present invention is to enable precise and easy adjustment of clock skew. A clock distribution circuit is designed and the placement and routing of the entire chip including the clock distribution circuit follows. Then the clock skew value is calculated and whether the calculated clock skew exceeds a target value is checked. When the clock skew exceeds the target value, the outputs of some driver elements are disconnected or connected to adjust the clock skew. The steps disconnecting or connecting the outputs of the drivers are repeated until the clock skew becomes equal to or smaller than the target value. | 6 |
BACKGROUND
1. Field of Invention
The present invention generally relates to a holding device. More particularly, the present relates to a holding device for eyeglasses that can be attached to clothing, such as a shirt pocket, clothing accessories, such as waist belts or purse straps, and flat surfaces, such as automobile visors.
2. Description of Prior Art
Many people have poor vision requiring them to wear eyeglasses or spectacles. For these people it is frequently convenient to take their eyeglasses off and place them in a pocket. This is particularly true for those who are required by law to wear prescription eyeglasses while operating a vehicle but prefer to take them off and carry them when no longer operating the vehicle. Also, people generally pay high prices for designer sunglasses and prescription eyeglasses and then are forced to hide them in a pocket or in a purse when not in use. Lastly, people wearing sunglasses frequently take them off once indoors or leave them inside the automobile while not driving.
Whether putting one's primary eyeglasses, a pair of sunglasses, or extra glasses in a pocket is convenient, there are associated problems. The most obvious problem is that if the glasses are not held securely in a shirt pocket, they will fall out and break. Further, it would be advantageous if the eyeglasses could be held in a selected position or location such as outside a shirt pocket, thereby increasing the ease of access, preventing them from moving around (particularly while engaged in sporting events), and still display the expensive appeal.
The problem identified in the preceding paragraph is well known, particularly to those who use eyeglasses of various sorts. Various types of eyeglass holders have been disclosed in the prior art purporting to solve the problem. In U.S. Pat. No. 305,185 to Hawkes an eyeglass case having a clothing fastening means attached thereto is shown. Eyeglass holders that engage the bridge of a pair of eyeglasses are also disclosed in the prior art. Exemplary of this type of eyeglass holders are U.S. Pat. No. 727,204 to Rogers: U.S. Reissue Pat. No. 12,771 to Dripps; U.S. Pat. No. 2,637,080 to Nemser; and U.S. Pat. No. 2,876,513 to McIntosh. Eyeglass holders substantially formed from wire frame members have also been disclosed in prior art. U.S. Pat. No. 171,681 to Meyer discloses a wire frame having paired clamp hooks which engage the lens frames of the eyeglasses. U.S. Pat. No. 730,633 to Jordan discloses an eyeglass holder having a bent hook attached to a hair pin. In U.S. Pat. No. 3,956,795 to Kosakai an ornamental brooch having a slidably mounted wire frame attached to the rear surface of the brooch and extending downwardly for receipt of the temples of eyeglasses is shown. A curved wire frame eyeglass holder having end loops that engage the temples of eyeglasses is disclosed in U.S. Pat No. 4,458,384, to Arnold. A further example of the prior art is shown in U.S. Pat. No. 2,818,621 to Pretz where an eyeglass holder having a tubular member pivotally disposed below an ornamental pin for receipt of the temple of eyeglasses is disclosed. Eyeglass holders that engage the temple of an eyeglass by means of a moveable grip and a stationary grip are shown in U.S. Pat. No. 4,771,515 to Guarro. An eyeglass holder having a vertical transverse cross-section holding means to engage one temple piece is disclosed in U.S. Pat No. 5,033,612 to Bivins. Eyeglass holders with an actuating clamp to engage a temple piece is disclosed in U.S. Pat. No. 5,351,098 to McDaniels. An eyeglass holder folded into a U-shaped clip to push in eyeglass temples is disclosed in U.S. Pat. No. 4,949,432 to Wisniewski. An eyeglass holder folded into a U-shaped clip with an additional leg section folded into the clip to push in eyeglass temples is disclosed in U.S. Pat. No. 5,408,728 to Wisniewski.
OBJECTS AND ADVANTAGES
As can be seen from the foregoing, numerous devices have been considered to provide means for temporarily holding a pair of eyeglasses to clothing and the like. However, these devices of the prior art do not provide the advantages of the present invention. For an eyeglass holder to be most effective during almost any activity, it must be capable of simultaneously securing both temple pieces to prevent flapping of the eyeglasses which can damage the temple hinges while still engaged by the eyeglass holder. Securing both temple pieces should further prevent slipping out from the holder which can break the glasses. The eyeglass holder should be capable of receiving and securing a variety of eyeglass sizes and styles with minimal effort by the wearer. The eyeglass holder should be capable of being pressed open for insertion of the eyeglass temples to prevent scratching or damaging the eyeglass temples and to ease inserting the eyeglass temples, a feature especially needed due to the variety of positions and places the holder can be attached. The eyeglass holder desirably should be rotatable to increase the variety of placement positions of the eyeglass holder. Since the eyeglass holder is usually displayed by the wearer, it should provide an aesthetic appeal such as jewelry, and desirably, a means for changing the eyeglass holders'0 appearance as the wearers clothes and jewelry change. The eyeglass holder also should be inexpensive to manufacture. All these requirements are the objects and advantages fulfilled by the eyeglass holder of the present invention. Further advantages of the invention will become apparent from a consideration of the drawings and ensuing description.
DRAWING FIGURES
In the drawing figures, closely related figures have the same number but different alphabetic suffixes.
FIGS. 1A to 1E show an eyeglass holder With alternate embodiments of an article fastening means.
FIGS. 2A to 2E show an eyeglass holder with alternate embodiments of a temple holding means.
FIGS. 3A to 3B show an eyeglass holder with alternate embodiments of a cover.
______________________________________Reference Numerals In Drawings______________________________________10 Article Fastening Means 40 Guides12 Spring Clip 41 Slits14 Base 42 Urging Means16 Temple Holding Means 44 Shaft18 Temple Clips 46 Torsion Spring20 Clip End 48 Fastening Lug21 Longer Clip End 50 Parallel Fastening Lug22 Face 52 Locking Ring24 Gap 54 Plate26 Opening 56 Compressible Supporting Element28 Cover 58 Extended Shaft End30 Connection 60 Receiver32 Recess 62 Rails34 Nodule 64 Snap36 Pivot 66 Cut-outs38 Pin 68 Notch39 Hook______________________________________
DESCRIPTION
FIG. 1A illustrates in a perspective view a preferred embodiment of an eyeglass holder of the present invention. The holder may be formed from many different materials or combination thereof. It is anticipated that either a metal may be used, such as silver, or a resilient plastic may be used for economic reasons. The holder comprises of an article fastening means 10, a temple holding means 16, and a plate 54. Article fastening means 10 is depicted as a spring clip 12, such as a money clip, having a generally rectangular side as a face 22, attached to temple holding means 16. Spring clip 12 is attached to temple holding means 16 by any suitable means, such as spot welding, soldering, or gluing. Temple holding means 16 is depicted as temple clips 18 separated by a distance of generally 11/2". Temple clips 18 are generally S-shaped with longer free clip ends 21 extending along face 22 for attachment. Clip ends 20 of temple clips 18 extend perpendicularly towards plate 54 for attachment. This forms lateral gaps 24 near face 22 along a side of the holder for eyeglass temple insertion. Temple holding means 16 is attached to cover 28 by any means as previously mentioned such as gluing. Although plate 54 may take any variety of shapes and sizes, plate 54 is generally rectangular in shape having a flatlike surface for attachment of temple holding means 16 and small enough to allow the simultaneous insertion of both eyeglass temples of a set of folded eyeglasses through gaps 24 without obstruction to eyeglass lenses or hinges. Operation of the eyeglass holder in FIGS. 1A and 1E is accomplished by sliding spring clip 12 onto the top edge of a typical pocket. Plate 54 is pressed thereby pivoting on temple holding means 16 and opening gaps 24. With both eyeglass temples in a folded position, both eyeglass temples are inserted simultaneously through gaps 24. Because both eyeglass temples now can be secured instead of just one temple, flapping of the eyeglasses against a wearer's chest is prevented. Thus, temple hinge damage and constant repositioning of the second eyeglass temple piece is also prevented. Securing both eyeglass temples is a distinctive advantage of the present invention.
FIG. 1B depicts in a perspective view a second embodiment of article fastening means 10. Article fastening means 10 is attached to temple holding means 16 to allow rotation of temple holding means 16. Face 22 has a centerly positioned opening 26 for receiving a connection 30. Connection 30 may be formed from a small segment of cylindrical piping. Connection 30 is received by a centerly positioned opening 26 on a base 14. Although base 14 may take a variety of shapes and sizes, base 14 is generally rectangular and flat taking the shape and size of face 22. The tightness of base 14 against face 22 is such that, as base 14 were rotated to any position, excessive rotational movement would be prevented. Base 14 and face 22 may be secured onto connection 30 by any suitable means such as widening each end of connection 30 or placing locking rings, not necessarily illustrated, at each end of connection 30.
FIG. 1C depicts in a perspective view a third embodiment of article fastening means 10. Face 22 includes nodules 34 in a circular pattern around opening 26. Base 14 includes recesses 32 around opening 26. Nodules 34 are received by recesses 32 when face 22 and base 14 are received by connection 30. As base 14 is rotated about connection 30, nodules 34 are received into recesses 32 for consistent repositioning of temple holding means 16 to various angles by the wearer.
FIG. 1D depicts in a perspective view a fourth embodiment of article fastening means 10. Article fastening means 10 comprises of a pivot 36, a pin 38, a hook 39, and face 22. Face 22 has opposing L-shaped guides 40 perpendicularly mounted. Base 14 has semicircular slits 41 arcing about the center of base 14 for insertion of guides 40. Guides 40, once inserted through semicircular slits 41, are bent tightly onto face 22. Temple holding means 16 now can be rotated about article fastening means 10 and remain at the selected position without excessive play.
Operation of holders depicted in FIGS. 1B, 1C, and 1D is accomplished by rotating article fastening means 10 to the desired angle with respect to temple holding means 16. Then the holder is fastened onto an article, such as an automobile visor, and the temple pieces are inserted and secured as previously stated for FIG. 1A. This rotational ability is another advantage of the present invention since a purse strap also may be the desired attachment area. For example, referencing FIG. 1B, the spring clip 12 may be rotated 90 degrees with respect to temple holding means 16. Spring clip 12 may then be fastened perpendicularly to the purse strap. Because a purse strap is generally worn over a shoulder and parallel to a wearer's arm, temple holding means 16 is parallel to the arm, and thus also the eyeglasses. Advantageously, the eyeglasses now may be suspended securely, conveniently, and decoratively on the purse strap without causing obstruction to the arm.
The article fastening means of the present invention has been described as a spring clip, or a pivot, pin, and hook arrangement in the previous embodiments. However, an article fastening means may consist of numerous other devices such as an elongated pin and pin-cover arrangement or a leather strap and button arrangement. Further descriptions presenting these embodiments are common to the art and not deemed instructive.
FIG. 2A depicts in a top plan view a second embodiment of temple clips 18. Temple clips 18 are generally U-shaped. Prior to the clip ends 20, are smaller U-shapes forming lateral gaps 24 along a side of the holder for eyeglass temple insertion.
FIG. 2B depicts in a perspective view a third embodiment of a temple clip 18. The singular elongated temple clip 18 is generally shaped in the same manner as a temple clip 18 depicted in FIG. 1A. However, the length of the singular temple clip 18 extends approximately the distance between the top edge of the upper temple clip 18 and the bottom edge of the lower temple clip 18 as described for FIG. 1A. This forms an elongated lateral gap 24 along a side of the holder for eyeglass temple insertion. FIG. 2C in a top plan view and FIG. 2D in a side plan view depict a fifth embodiment of temple holding means 16. Temple holding means 16 is comprised of compressible supporting elements 56 extending horizontally along a generally rectangular plate 54 and base 14. Compressible supporting elements 56 form lateral gaps 24 along a side of the holder for eyeglass temple insertion. Compressible supporting element 56 is preferably rubber, although various other materials may be used such as foam wrapped by plastic. Plate 54 and base 14 are forced together by an urging means 42 comprising of a torsion spring 46 pivotally mounted on a shaft 44. Shaft 44 is received through holes in fastening lugs 48 that are attached to base 14 and plate 54. Shaft 44 may be secured by means of a locking ring 52. Temple holding means 16 may by opened for insertion of the eyeglass temples through the lateral gaps 24 by either pressing on plate 54 near shaft 44, or lifting plate 54 near gaps 24.
FIG. 2E depicts in a perspective view an alternate embodiment of temple holding means 16 of FIGS. 2C and 2D whereby each end 58 of shaft 44 is extended perpendicularly from urging means 42 along the width of face 22 ending at the opposite side on face 22. This forms lateral gaps 24 located on a side of the holder for eyeglass temple insertion. Shaft 44 may be encased by a compressible supporting element 56 to prevent scratching of the eyeglass temples if a rigid material, such as metal, is used to form shaft 44. Plate 54 is secured to shaft 44 providing resistance to torsion spring 46. Operation of holder in FIG. 2E is performed by either pressing on plate 54 or lifting shaft ends 58.
The urging means of the present invention has been described as a torsion spring and shaft arrangement in the previous embodiments. However, an urging means may be constructed from numerous other devices to reap the benefits of this invention such as a leaf spring bent in a U-shape arrangement or a leaf spring bent in a V-shape and pivot arrangement. Further descriptions presenting these embodiments are common to the art and not deemed instructive.
FIG. 3A depicts an embodiment of a cover 28. Cover 28 is an ornamental object that comprises of parallel rails 62 and cut-outs 66 located underneath. A receiver 60, generally rectangular in shape, is attached to temple holding means 16. Edges underneath receiver 60 comprise of notches 68. Cover 28 is received by sliding rails 62 onto the edges of receiver 60 and temporarily secured when notches 68 are received by cut-outs 66.
FIG. 3B depicts an alternate embodiment of cover 28. Cover 28 is a circular-shaped ornamental object with a snap 64 located underneath. Receiver 60 is bent H-shaped. Each end of the two longitudinal sections of receiver 60 are attached to temple holding means 16. The lateral section of receiver 60 has parallel rails 62 with curved edges. Cover 28 is temporarily attached to receiver 60 by snapping on snap 64 within rails 62 of receiver 60.
The attachment means for a cover onto a temple holding means has been presented as permanent, such as soldering, and releasable, such as a slide-on or snap-on arrangement. Numerous other cover attachment means may be employed to accomplish this interchangeable-cover advantage of the invention, such as: an adhesive pad arrangement; a releasable hinge and snap arrangement; or a flattened hook and detente arrangement. Further descriptions presenting these embodiments are common to the art and not deemed instructive.
The shapes, sizes, and designs of the cover and receiver arrangement are only limited by the imagination. The cover is an advantage of the present invention since the cover conceals the mechanical aesthetics of the holder and provides an area for inscriptions, logos, jewelry, and the like. A wearer may attach a diamond-shaped, gem-studded silver cover to aesthetically match a silver watch. The next day, the wearer may attach a gold, cat-shaped cover to match a set of gold earrings. Thus, the wearer may have several covers for various outfits and need only one eyeglass holder.
Although the descriptions above contain many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of the presently preferred embodiments of this invention. | A holder for eyeglasses and the like is provided. The holder is designed to be attached to articles of clothing, clothing accessories, automobile visors, or other areas whereby it is available for conveniently receiving and retaining a pair of eyeglasses. The eyeglass holder desirably can be rotated for awkward areas of attachment, or convenient areas of placement such as a purse strap. Notably, the holder can be pressed open by the wearer for ease of eyeglass temple bar insertion or removal. The holder can desirably have a releasable cover for a wearer to have a variety of choices of holder aesthetics. The holder broadly comprises of a clip or a pin, pivot, and hook arrangement; a cylindrical connection or a slit and guide connection; and a frontal elongate plate member pivotally mounted onto a base member; and, optionally, a removable cover. | 8 |
BACKGROUND OF THE INVENTION
Up to this time, wooden materials have been used for producing columns and beams and braces. These wooden components are framed together to form a building skeleton. However, in order to improve the strength, stability, and durability of the components, use of steel materials has also been considered. Applicant of this application proposed a composite beam which is formed of a steel material and a wooden material (Japanese patent laid open TOKUKAIHEI 8-13690). This composite beam is illustrated by the perspective views shown in FIG. 1 a and FIG. 1 b . As shown in these figures, this composite beam is formed of a steel beam ( 3 ) and a wooden member ( 4 ). The cross section of the steel beam is I-shaped. Namely, a pair of flat plate members ( 1 ) are lined in parallel and are connected each other by a perpendicular plate member ( 2 ) at the central position of the flat plate members ( 1 ). On the outer surfaces of the flat plate members ( 1 ), wooden members ( 4 ) are attached. Under this configuration, the strength, stability, and durability of the component is increased due to the use of the steel beam member ( 3 ), and the application of conventional wood-working processing to the beam becomes possible due to the attachment of the wooden members ( 4 ).
In the above-described composite beam structure, there are provided two bolts ( 5 ) for connecting the column ( 6 ) to the beam, protruding upward from the upper surface of the wooden member ( 4 ). In order to connect the columns with the beam member ( 3 ), the two bolts ( 5 ) are inserted into two holes among four holes formed at the bottom of the column ( 6 ). In addition, an H-shaped metal bracket ( 7 ) is attached across the wooden member ( 4 ) and the column ( 6 ). In order to secure the joint between the two components, the metal bracket ( 7 ) is firmly fixed to the composite beam by driving nails ( 8 ) into the wooden member ( 4 ) and the column ( 6 ) on both sides of the wooden member ( 4 ) and the column ( 6 ).
According to the above described conventional joined structure of the composite beam and column as shown in FIGS. 1 a and 1 b , however, one must drive the nails ( 8 ) through the bracket ( 7 ) to join the two members, making it time-consuming and labor-intensive. Also, in order for a construction worker to work efficiently, four holes need to be created at the four corners of the square bottom surface of the column ( 6 ) so that he/she does not need to find whether the column ( 6 ) is positioned in a right direction in which the two bolts ( 5 ) can be inserted into the bottom holes of the column ( 6 ). This increases the labor for processing the column ( 6 ). In addition, because the bracket ( 7 ) is fixed across the sides of the wooden member ( 4 ) and the column ( 6 ) and therefore is exposed, it is inevitable that the attached bracket ( 7 ) contacts with other surrounding components such as the metal fittings or furring strips, causing excess time and labor during construction works of the building skeleton.
SUMMARY OF THE INVENTION
In general, in one aspect, the present invention is a joint structure for joining a composite beam and a column. The composite beam comprises an I-beam and a pair of wooden members, each attached to one of two opposing flat plate members of the I-beam. The joint structure further comprises a mortise pin provided on the composite beam and protruding beyond a outer surface of one of the wooden members, which mortise pin is provided with a through-hole at a predetermined position therein, a bottom hole provided at a bottom surface of the column, which bottom hole is adapted to receive the mortise pin, and a horizontal hole provided at a side face of the column at a position corresponding to the through-hole of the mortise pin. The composite beam is connected to the column by inserting the mortise pin into the bottom hole of the column and inserting a locking pin into the through-hole of the mortise pin and the horizontal hole of the column such that the joint of the composite beam and the column is firmly secured.
In general, in another aspect, the present invention is a method of joining a composite beam and a column, which composite beam comprises an I-beam and a pair of wooden members, each attached to one of two opposing flat plate members of the I-beam. The method comprises providing a mortise pin on the composite beam such that the mortise pin protrudes beyond a outer surface of one of the wooden members, which mortise pin is provided with a through-hole at a predetermined position therein, providing a bottom hole at a bottom surface of the column, which bottom hole is adapted to receive the mortise pin, providing a horizontal hole at a side face of the column at a position corresponding to the through-hole of the mortise pin, connecting the composite beam with the column by inserting the mortise pin into the bottom hole of the column, and inserting a locking pin into the through-hole of the mortise pin and the horizontal hole of the column such that joint of the composite beam and the column is firmly secured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a perspective view of a disassembled prior art joint structure of a composite beam and a column showing a prior art of the present invention.
FIG. 1 b is a respective view of the assembled joint structure of FIG. 1 a.
FIG. 2 a is a perspective view of a disassembled joint structure of a composite beam and a column showing an embodiment of the present invention.
FIG. 2 b is a perspective view of the assembled joint structure of the embodiment o FIG. 2 a.
FIG. 3 a is a perspective view of a disassembled joint structure of a composite beam and a column showing an embodiment of the present invention.
FIG. 3 b is a perspective view of an assembled joint structure of the embodiment of FIG. 3 a.
FIG. 4 a is a perspective view of a disassembled joint structure of a composite beam and a column showing an embodiment of the present invention.
FIG. 4 b is a perspective view of an assembled joint structure of the embodiment of FIG. 4 a.
FIG. 5 is a perspective view of the important part showing another form of cutout as an embodiment of the present invention.
FIG. 6 a is a cross-sectional view of the major part of the joint structure of a composite beam an a column wherein a shock-absorber is installed.
FIG. 6 b is a cross-sectional view of the major part of the joint structure of a composite beam and a column wherein a shock-absorber is installed.
DETAILED DESCRIPTION
Referring now to the drawings wherein like reference characters are used for like parts throughout the several views, the present invention is explained in detail as follows.
FIGS. 2 a and 2 b are perspective views of the joint structure of a composite beam and column showing an embodiment of the present invention.
FIG. 2 a shows a disassembled state, and FIG. 2 b shows an assembled state. As shown in FIG. 2 a , a metal mortise pin ( 10 ) is provided upright on a flat plate member ( 1 ) of the steel beam member ( 3 ). The metal mortise pin ( 10 ) protrudes upward beyond the upper surface of the wooden member ( 4 ) through a mortise hole ( 14 ) which is formed through the wooden member ( 4 ) at a position corresponding to the position of the metal mortise pin ( 10 ). The metal mortise pin ( 10 ) is provided with a through-hole ( 9 ). The through-hole ( 9 ) horizontally penetrates the metal mortise pin ( 10 ) in a longitudinal direction of the steel beam member ( 3 ) at a predetermined height from the surface of the flat metal plate ( 1 ). A bottom hole ( 11 ) is formed at the bottom of the column ( 6 ) having a predetermined depth in a longitudinal direction of the column ( 6 ). Also, a horizontal hole ( 12 ) is formed through the column ( 6 ) in a longitudinal direction of the steel beam member ( 3 ) at a height corresponding to the height of the through-hole ( 9 ) of the metal mortise pin ( 10 ). Under this configuration, the column ( 6 ) is connected with the composite beam by inserting the metal mortise pin ( 10 ) into the bottom hole ( 11 ). Then, a locking pin ( 13 ) is inserted into the horizontal hole ( 12 ) of the column ( 6 ) and the through-hole ( 9 ) of the metal mortise pin ( 10 ) so that the metal mortise pin ( 10 ) inserted into the bottom hole ( 11 ) is locked by the locking pin ( 13 ) at that position. For the locking pin ( 13 ), a drift-pin can be preferably used. By using a drift-pin for the locking pin ( 13 ), the locking pin ( 13 ) can be reliably inserted into the through-hole ( 9 ) of the mortise pin ( 10 ) and the horizontal hole ( 12 ) of the column ( 6 ) even when there is a slight deviation between the horizontal hole ( 12 ) of the column ( 6 ) and the through-hole ( 9 ) of the metal mortise pin ( 10 ).
Under this configuration, the composite beam ( 3 ) can be connected with the column ( 6 ) without using nails, thereby saving the labor needed to drive the nails into the composite beam and the column ( 6 ). At the same time, because the metal mortise pin ( 10 ) and the locking pin ( 13 ) are not exposed outside, the problem of hitting or contacting surrounding components caused by having the attachment, such as the bracket ( 7 ) shown in FIG. 1, is avoided. Moreover, because only a single metal mortise pin ( 10 ), mortise hole ( 11 ), and horizontal hole ( 12 ) are needed for connecting the composite beam ( 3 ) with the column ( 6 ), the labor required for processing the column ( 6 ) for connecting the components is greatly reduced. Also, because of the elimination of nailing work and the problem caused by the contact between the joint structure and other surrounding components, workability of this joint structure of the composite beam and column is greatly improved compared to the joint structure shown in FIGS. 1 a and 1 b.
According to the joint structure of a composite beam and a column of the present invention, there are a plurality of embodiments in connection with the methods for providing a mortise pin on the composite beam.
According to an embodiment shown in FIGS. 2 a and 2 b , the metal mortise pin ( 10 ) is welded onto the surface of the flat plate member ( 1 ) of the composite beam. A mortise hole ( 14 ) is formed through the wooden member ( 4 ) at a position corresponding to the metal mortise pin ( 10 ). The wooden member ( 4 ) is attached on the flat plate member ( 1 ) such that the metal mortise pin ( 10 ) protrudes beyond the upper surface of the wooden member ( 4 ) through the mortise hole ( 14 ) thereof. An advantage of this embodiment is that the metal mortise pin ( 10 ) can be easily provided on the flat plate member ( 1 ) of the steel beam member ( 3 ) by using a welding process.
According to an embodiment shown in FIGS. 3 a and 3 b , the metal mortise pin ( 10 ) is provided on a flat metal plate ( 15 ) in a manner that the metal mortise pin ( 10 ) is fixed standing upright on the flat metal plate ( 15 ). Then, the flat metal plate ( 15 ) is fixedly attached on the upper surface of the wooden member ( 4 ). The metal mortise pin ( 10 ) can be fixed on the flat plate metal ( 15 ) by using a welding process or by screwing bolts. In order to firmly fix the mortise pin ( 10 ) on the flat metal plate ( 15 ), screwing bolts is preferred. The flat metal plate ( 15 ) can be fixedly attached on the wooden member ( 4 ) by a method, such as nailing, using nuts and bolts. In order to firmly fix the flat metal plate ( 15 ), a bolt hole ( 18 ) is formed through the wooden member ( 4 ) and the flat plate member ( 1 ), and the bolt is inserted into this bolt hole ( 18 ) such that the top end of the bolt protrudes beyond the opposite side of the flat plate member ( 1 ). Then the protruding top end of the bolt is fixed by using a nut ( 17 ) as shown in FIG. 3 a.
It is also possible that the flat metal plate ( 15 ) be directly fixed on the flat plate member ( 1 ). In this case, the metal flat plate ( 15 ) can be fixedly attached to the flat metal member ( 1 ) by a method, such as welding, using nuts and bolts. In order to firmly fix the flat metal plate ( 15 ), it is preferable that a bolt hole ( 18 ) be formed through the flat plate member ( 1 ), and thereafter the bolt is inserted into this bolt hole such that the top end of the bolt protrude beyond the opposite side of the flat plate member ( 1 ), and then the protruding top end of the bolt be fixed by using a nut ( 17 ) as shown in FIG. 3 a.
According to an embodiment shown in FIGS. 4 a and 4 b , a mortise hole ( 14 ) is formed through the wooden member ( 4 ) at a position corresponding to the position of the metal mortise pin ( 10 ). The metal mortise pin ( 10 ) is inserted into the mortise hole ( 14 ) such that the top end of the metal mortise pin ( 10 ) protrudes beyond the upper surface of the wooden member ( 4 ), similarly to the embodiment shown in FIG. 2 . In this embodiment, however, the flat metal plate ( 15 ) is positioned between the flat plate member ( 1 ) and the wooden member ( 4 ). A cutout ( 19 ) is formed at the bottom of the wooden member ( 4 ), the width and thickness of which is adjusted to that of the flat metal plate ( 15 ), such that the flat metal plate ( 15 ) can be stored in a space formed by the cutout ( 19 ).
Although the embodiment shown in FIG. 2 does not cause too much problem with regard to the contact with other surrounding components, the upper face portion of the flat metal plate ( 15 ) is exposed outside. Therefore, it is possible that the flat metal plate ( 15 ) contacts with the surrounding components. Contrary, according to the configuration of this embodiment of FIG. 4, the flat metal plate ( 15 ) is accommodated in the cutout space, not exposed outside, and therefore does not contact with other surrounding components. For this reason, this embodiment is particularly advantageous in that it can effectively avoid contact of the joint structure with other surrounding components.
According the configuration shown in FIG. 4, the cutout ( 19 ) is formed throughout the entire width of the wooden member ( 4 ). However, the cutout ( 19 ) may be formed in a manner that side edges are left uncut as shown in FIG. 5 . Under such configuration, the outside view of the joint structure is almost the same as that of the embodiment shown in FIG. 2 b . Because the flat metal plate ( 15 ) is not exposed to the outside, the contact of the flat metal plate ( 15 ) with the surrounding components is completely prevented.
Under the configuration of the joint structure of composite beam and column as described in the above-described embodiments, a shrinkable shock absorbing member can be provided between the bottom surface of the column ( 6 ) and the top surface of the wooden member ( 4 ) or the flat metal plate ( 15 ). For example, in the embodiment shown in FIG. 2 or 4 , the shock absorbing member can be provided between the bottom surface of the column ( 6 ) and the upper surface of the wooden member ( 4 ). In the embodiment shown in FIG. 3, the shock absorbing member can be provided between the bottom surface of the column ( 6 ) and the upper surface of the flat metal plate ( 15 ).
FIG. 6 shows a cross sectional view of the embodiment shown in FIG. 4 or 6 having the shock absorbing member ( 20 ) between the column ( 6 ) and the wooden member ( 4 ). Owing to cumulative imprecision of processing of the column ( 6 ) or other joint components, deviation of the relative position between the through hole ( 9 ) of the metal mortise pin ( 10 ) and the horizontal hole ( 12 ) of the column ( 6 ) may occur as shown in FIG. 6 b . If the deviation between the horizontal hole ( 12 ) and the through hole ( 9 ) becomes large, it becomes difficult to insert the locking pin ( 13 ) through the horizontal hole ( 12 ) and the through-hole ( 9 ) even if a drift pin is used for the locking pin ( 13 ). If the locking pin ( 13 ) is forced into the horizontal hole ( 12 ) and the through-hole ( 9 ), there is a danger that the locking pin ( 13 ) may exert excessive force against an inside face of the horizontal hole ( 12 ) and eventually cause a crack of the column ( 6 ). As a measure to prevent such occurrence, a shrinkable shock absorbing member ( 20 ) can be provided between the bottom face of the column ( 6 ) and the upper surface of the wooden member ( 4 ) or that of the metal plate ( 15 ). By having that shrinkable shock absorbing member ( 20 ) between the two members, the deviation between the through hole ( 9 ) and the horizontal hole ( 12 ) can be effectively adjusted so that the locking pin ( 13 ) is prevented from getting lodged inside the column ( 6 ) or eventually causing crack of the column ( 6 ). Although the material which can be used for that shrinkable shock absorbing member is not restricted to any specific material, ethylene-propylene copolymer (EPDM) or styrene butadiene rubber (SBR) can be used.
While the present invention has been described with respect to a limited number of preferred embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. The appended claims are intended to cover all such modifications and variations which occur to one of ordinary skill in the art. | A joint structure for joining a composite beam and a column is disclosed. The composite beam includes an I-beam and a pair of wooden members. The joint structure includes a mortise pin provided on the composite beam and protruding beyond an outer surface of one of the wooden members. The mortise pin is provided with a through-hole at a predetermined position. A bottom hole is provided at a bottom surface of the column in a manner that the bottom hole is adapted to receive the mortise pin. A horizontal hole is provided at a side face of the column at a position corresponding to the through-hole of the mortise pin. The composite beam is connected with the column by first inserting the mortise pin into the bottom hole of the column and then inserting a locking pin into the through-hole of the mortise pin and the horizontal hole of the column such that joint of the composite beam and the column is firmly secured. A method of joining a composite beam and a column is also disclosed. | 8 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
The concurrently filed commonly assigned U.S. patent application Ser. No. 147,251, filed May 6, 1980, for Microprogrammed Digital Data Processing System Employing Tasking at a Microinstruction Level, D. R. Kim and J. H. McClintock, inventors, contains subject matter related to this application.
INTRODUCTION
The present invention relates to improved means and methods for performing data processing operations in a microprogrammed electronic digital computer. More particularly, the present invention relates to improved means and methods for controlling the execution and sequencing of microinstructions in a manner such that pipelined multiprocessing is provided at a microinstruction level.
BACKGROUND OF THE INVENTION
A particular architectural concept that has allowed for more flexibility in computer design and also in computer programming has been the concept of microinstructions. Initially, a microinstruction was thought of as merely a set of control bits employed within a macroinstruction format. Such control bits were, for example, employed to provide a corrective measure during the execution of a multiplying instruction or shift instruction and the like. Gradually, as the microprogramming concept enlarged, the macroinstruction specified the particular routine to be performed, such as the addition of two operands. The execution of the macroinstruction was then accomplished through a sequence of executions of microinstructions, each of which specified the particular gates to be set thereby. Since a plurality of macroinstructions could be implemented by a finite set of microinstructions, it was then apparent that these same microinstructions could be stored in a separate storage to be addressed in a particular sequence upon the execution of different macroinstructions. It was further recognized that various sequences of microinstructions could be formulated to carry out the particular operations and separately stored in any memory. Thus, a great variety of sequences of microinstructions could be created to carry out a great variety of routines.
The concept of microinstructions or microprograms, then, became one of providing sub-instructional sets which were masked or hidden from the programmer, thus, simplifying the writing of particular programs by minimizing the number of individual specific steps that had to be called for by the programmer. Furthermore, the concept of microprogramming allows the computer designer to design a more inexpensive computer system that could provide a great variety of routines to the computer user without the requirement of individual functions being implemented in hard-wired circuitry.
Microprogramming may thus be broadly viewed as a technique for designing and implementing the control function of a digital computer system as sequences of control signals that are organized on a word basis and stored in a fixed or dynamically changeable control memory. Detailed examples of some known approaches to the design of microprogrammed digital computers can be found in U.S. Pat. No. 3,886,523, Ferguson et al., issued May 27, 1975, U.S. Pat. No. 4,155,120, Keefer and Kim, issued May 15, 1979, U.S. Pat. No. 4,181,935, Feeser and Gerhold, issued Jan. 1, 1980 and U.S. Pat. No. 4,038,643, Kim, issued Jul. 26, 1977; in the book by S. S. Husson, "Microprogramming: Principles and Practices", Prentice-Hall, Inc. (1970); in the book "Foundations of Microprogramming", Argrausala, et al., Academic Press, Inc., 1976; in the article "Microprogramming--Another Look at Internal Computer Control", M. J. Flynn, I.E.E.E. Proc., Vol. 63, No. 11, Nov. 1975, pp. 1554-1567; and in the article "Microprogramming: A Tutorial and Survey of Recent Developments", I.E.E.E. Transactions on Computers, Vol. C-29, No. 1, Jan. 1980.
In recent years the concept of microprogramming has been extended for use in conjunction with pipelined architectures as described, for example, in the article "The Microprogramming of Pipelined Processors, P. M. Kogge, 4th Annual Symposium on Computer Architecture, Mar. 1977, pp. 63-69; and also in the article "A Pipeline Architecture Oriented Towards Efficient Multitasking", F. Romani, Euromicro, Oct. 1976, Vol. 2, No. 4, North-Holland Publishing Co., Amsterdam.
SUMMARY OF THE PRESENT INVENTION
An important feature of the present invention is to further extend the advantages of microprogramming by providing for pipelined multiprocessing at a microinstruction level in a microprogrammed computer system.
Another feature of the present invention is to provide a microprogrammed data processing system employing pipelining and microinstruction tasking in a manner which permits advantage to be taken of both multiprocessing and multiprogramming at a microinstruction level.
A further feature of the present invention is to provide a microprogrammed data processing system which provides for dynamic resource allocation in conjunction with microinstruction tasking and pipelined multiprocessing so as to further enhance the capability and advantages derivable from microinstruction tasking.
In a preferred embodiment of the invention, a microprogrammed data processor is provided with a three-stage pipelined architecture having the capability of managing and dynamically allocating resources for up to sixteen activated tasks while concurrently providing for the execution of three dynamically selectable task microinstructions, each task being executed as a result of the performance of one or more task microinstructions. In the preferred embodiment, the three-stage pipelined architecture is implemented so as to in effect provide three separate processors operating 120° out of phase with one another and sharing the same physical hardware. Each processor is capable of executing task microinstructions in any desired intermixed order regardless of the particular task to which they belong, thereby providing a multiprogramming capability for each processor. Since, in the preferred embodiment, there are in effect three separate processors having this multiprogramming capability, the added capability of multiprocessing is advantageously achieved. A task controller serves to manage and dynamically select the tasks to be executed as well as to dynamically allocate resources for activated tasks as required.
The specific nature of the invention as well as other objects, features, advantages and uses thereof will become evident from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an overall computer system in which the present invention may be incorporated.
FIG. 2 is a block diagram of the MLP Processor illustrated in FIG. 1.
FIG. 3 is a block diagram of the Processing Element PE in FIG. 2.
FIG. 4 diagrammatically illustrates the basic manner in which tasks are managed in a preferred embodiment.
FIG. 5 illustrates an example of how the preferred embodiment dynamically allocates resources for activated tasks in performing the calculation (A+B)-(1+C).
FIG. 6 illustrates an example of how task microprogramming may be provided in the preferred embodiment.
FIG. 7 illustrates how tasks are performed using the three-stage pipeline architecture provided for the preferred embodiment.
FIG. 8 illustrates an example of how the preferred embodiment employs tasking microprogramming, and multiprocessing for concurrently performing the three calculations (A+B)+(C+D)=H; (A+B)-E=I; and (C+D)-E=J.
FIG. 9 is a block diagram illustrating a preferred embodiment of the Program Controller PE of FIG. 3.
FIG. 10 is a block diagram illustrating a preferred embodiment of the Task Controller TC of FIG. 3.
FIG. 11 is a block diagram illustrating a preferred embodiment of the Stored Logic Controller SLC in FIG. 3.
FIG. 12 is a block diagram illustrating a preferred embodiment of the Auxiliary Control Memory ACM in FIG. 11.
FIG. 13 is a block diagram illustrating a preferred embodiment of the Sequence Control Memory SCM in FIG. 11.
FIG. 14 is a block diagram illustrating a preferred embodiment of the main Data Path DP in FIG. 3.
FIG. 15 is a block diagram illustrating a preferred embodiment of the Address and State Unit ASU in FIG. 3.
FIG. 16 is a flow chart illustrating the operation of the ASU Change Queue ASU-CQ in FIG. 15.
FIG. 17 is a block diagram illustrating a preferred embodiment of the Memory System MS in FIG. 2.
GENERAL DESCRIPTION
Overview (FIG. 1)
In a preferred embodiment, the present invention may be incorporated in an overall system comprised of one or more MLP simplex systems, such as illustrated in FIG. 1. Each simplex system typically comprises an MLP Processor, a Maintenance Processor, and an I/O Subsystem with its associated peripherals P. These simplex systems are interconnected by an Exchange EX and a Global Memory GM which allows the system software to determine the degree of coupling between the simplex systems.
The I/O subsystem in FIG. 1 contains the user input/output devices and storage for complete sets of program and data segments. The Global Memory GM permits processor interconnection and contains program and data segments shared by the multiple processors. Each MLP processor has a local memory subsystem containing those program and data segments being processed on the MLP processor.
In the preferred embodiment, the MLP processor is an integrated hardware and firmware system which implements a high-level virtual instruction set. The instructions of this set are individually programmed by a set of firmware instructions which execute on lower-level MLP hardware. An important feature of the invention is that the MLP processor uses multiprogramming and multiprocessing techniques at the hardware (microinstruction) level to achieve a high degree of parallelism between the execution of the firmware instructions corresponding to multiple high-level instructions.
In accordance with the present invention, the MLP processor considers a sequence of the applied high-level virtual instructions as a set of tasks to be performed. It will be understood that each of these tasks can be performed by executing one or more microinstructions on a low-level processor. Some of these tasks may need to use data which is prepared by preceding tasks. However, for typical data processing applications, a substantial number of the tasks do not have such dependencies. Thus, some or all of the performance of the tasks can be overlapped. This potential for overlap is used to particular advantage by the MLP processor of the present invention which provides for both multiprogramming and multiprocessing at the hardware (microinstruction) level.
MLP Processor Organization (FIG. 2)
In the preferred embodiment being considered herein, the MLP processor is partitioned into hardware modules as shown in FIG. 2. The Processing Element PE contains both the basic data path and the storage for the processor microcode. The Memory Subsystem MS contains both the local memory of the processor and the processor's interface to the Global Memory GM (FIG. 1). MS also preferably contains a cache module to improve the average access time and the bandpass of the local memory. The Host Dependent Port HDP provides the processor's interface to the I/O (FIG. 1). HDP is controlled by a task initiated by microinstructions from PE as well as a request from HDP. In the preferred embodiment, this HDP task is one of the multiple tasks that may be executed concurrently with other processor tasks. The Host Console Port HCP is the processor's interface with the system port of the Maintenance Processor MP (FIG. 1) through which the maintenance and control of the processor is performed. HCP has read-write access to all components of the processor state for initialization and maintenance.
Processing Element PE (FIG. 3)
As illustrated in FIG. 3, a preferred implementation of the Processing Element PE comprises five major components:
1. A Program Controller PC which parses program code words into operators and parameters and, in response to each operator, determines one or more tasks to be performed along with the resource requirements for each task.
2. A Task Controller TC which manages the tasks and controls the sequence in which tasks are performed.
3. A main Data Path DP which stores the primary data items for the tasks along with manipulation facilities for performing logical and arithmetic operations on these data items.
4. An Address and State Unit ASU which contains the storage for memory addresses along with facilities for their manipulation. ASU also stores most of the state of the high-level architecture.
5. A Stored Logic Controller SLC which stores the microcode used for executing tasks. In response to TC, DP and ASU, SLC issues microinstructions to the various components of PE in the proper sequences to perform the tasks applied thereto by TC. A task may require one or more microinstructions for its performance.
It will thus be understood that operator-level data, memory addresses and state are stored in DP and ASU, and that SLC issues microinstructions which causes these units to select the operations and data required in order to perform each task. During task execution, selected conditions are provided which flow to SLC and affect microinstruction sequencing, thereby completing the basic feedback loop in PE.
In order to achieve high performance, the preferred embodiment employs several levels of concurrency in the performance of PE operations as follows:
1. PC and TC operations (fetching, converting of operators into tasks by PC and managing and activating of tasks by TC) are concurrent with the performance of microinstructions by SLC, DP, and ASU.
2. SLC, DP and ASU operate concurrently with each other, so that during each clock cycle a microinstruction is executed by DP and ASU while a new microinstruction and state is generated by SLC.
3. SLC, DP and ASU are implemented with a multiple-stage pipeline architecture which permits multiple tasks to be concurrently performed in a manner which takes advantage of both multiprogramming and multiprocessing techniques. As is well known, multiprogramming is a technique in which the execution of multiple programs is interleaved on a single processor, whereby time intervals during which one program is waiting (i.e., not ready to execute) are used to execute portions of other programs. As is also well known, multiprocessing is a technique in which multiple processors are used to execute one or more programs.
Basic Operation of the Processor Element PE (FIG. 3)
Before considering specific implementations of the MLP Processor, some basic operating features will first be presented.
Generation of tasks
The generation of tasks in the Processor Element PE is performed by the Program Controller PC and the Task Controller TC. PC examines the sequence of raw words of code derived from applied high-level instructions, determines the sequence of high-level operators to be performed, and, for each of these operators, determines one or more tasks to be performed. Each task, along with its resource requirements, is forwarded to TC. PC also decodes any parameters which may be provided for each operator, and forwards these to the main Data Path DP.
TC either inserts the task into the active mix or enters a holding state if sufficient resources are not available for its insertion. The reasons why TC may not be able to insert the task include the following:
1. The mix may be full (that is, the hardware limit on the number of active tasks has been reached), in which case PC must wait for the termination of the Oldest Active Task (OAT);
2. Sufficient free registers may not exist to satisfy the task's requirements in which case PC must wait for other tasks to free enough registers;
3. One or more of the change queues required by the task (to be described later) may be locked, in which case PC must wait for them to become unlocked.
PC may also be used for the detection of external interrupt conditions and, with the aid of the Maintenance Processor MP (FIG. 1), also detects alarm interrupt conditions. Typically, these conditions may be handled by special tasks which PC inserts into the mix.
Management of waiting tasks and wait conditions
During processor operation, every active task is in one of four states: (1) Executing (task is presently being executed), (2) Writing (task is not ready for execution until some condition has been satisfied), (3) Ready (task is ready to be executed--that is, the task is not waiting on any condition), or (4) End Of Task (EOT) (task waiting to be terminated). The Task Controller TC keeps track of the state of each task. At the completion of each task microinstruction, TC is presented with an appropriate task status condition for use in determining whether the Executing state of the task should be continued, or the task put in another state (e.g. Waiting or (EOT)). FIG. 4 diagrammatically illustrates the manner in which the task states are managed in the preferred embodiment in which, for example, there may be a maximum of 16 active tasks and a maximum of three tasks being executed at any one time.
Selection of Ready tasks
On each clock cycle, the Task Controller TC selects one task microinstruction to be executed from among the Ready tasks. This selected task microinstruction may be the first microinstruction of a newly activated task or a second, third, etc. microinstruction of a previously activated task which was previously put in a Waiting state (e.g. because not all the data required for the next task microinstruction was not available at that time). TC marks the selected task as "in execution" so that it will not select it again on the next clock cycle. This is done because, in the preferred embodiment, execution of each task microinstruction is performed in three stages requiring three clock cycles.
If there are no Ready tasks (i.e. all active tasks are either Waiting, Executing, or at (EOT)), then TC selects a special null task microinstruction which is always Ready. The null task microinstruction is never marked "in execution", so that it may be selected on the next clock cycle, if necessary. The null task microinstruction may, for example, simply be a loop of "null" operations.
If there is more than one Ready task, TC may, for example, make its selection according to a simple, static, two-level priority system. The distinction between high priority and low priority tasks may be indicated by the programmer of the instruction flow. Among tasks of the same priority, the selection by TC is arbitrary.
Synchronization of tasks and dynamic register assignment
For the preferred embodiment being considered, a conventional stack-oriented operator set may be assumed. A basic understanding of how one or more stacks may be employed in a data processing system can be obtained, for example, by reference to the article E. A. Hauck and B. A. Dent, "Burroughs B 6500/7500 Stack Mechanism", AFIPS Conference Proceedings, 1968 SJCC, p. 245; and also to the series of articles in Computer, May 1977, pp. 14-52, particularly the articles entitled: "Stack Computers: An Introduction", D. M. Bulman, pp. 18-28 and "Exploring a Stack Architecture", R. P. Blake, pp. 30-39. The contents and teachings of these articles are to be considered as incorporated herein.
The Burroughs 6800 computer system is an example of the use of a stack-oriented operator set. As is conventional in such a system, at least one stack is provided for operation in a manner such that communication between microinstructions normally occurs via the top of the stack. In order to further enhance this important communication mechanism, the present invention additionally provides a substantial number of "floating" top-of-stack register pairs. Operation is then caused to be such that the stack items which an operator takes as its input and the stack items which a task produces as its outputs are stored in register pairs which are assigned dynamically to the task when it is initiated into the mix of tasks. Each register pair has an associated validity bit, which indicates whether the corresponding stack item has been "produced". If a task microinstruction requires it to "consume" one of its input stack items which has not yet been produced, the task is put into a Waiting state by the hardware. It is put back into the Ready state when the stack item is produced.
The Task Controller TC keeps track of a virtual "top-of-stack image", which is a list of register pairs. This list indicates the top-of-stack configuration. TC also keeps a list of "free" (unassigned) register pairs. These lists are updated whenever a task is initiated or terminated.
As an example of the above, assume that the calculation (A+B)-(1+C) is to be performed using tasks T1, T2, T3, T4, T5, T6 and T7 assigned as follows:
______________________________________Tasks Operators______________________________________T1 VALC AT2 VALC BT3 ADD: (A + B) = S1T4 ONET5 VALC CT6 ADD: (1 + C) = S2T7 SUBTRACT: (S1 - S2)______________________________________
It will also be assumed for this example that no other tasks are active, that the top-of-stack list is empty, and that the free register list comprises eight registers R0, R1, R2, R3, R4, R5, R6 and R7 which are not currently assigned. The initial state of the Processing Element PE for this example is thus:
______________________________________Task mix: No active tasksTop-of-stack list: No registers assigned (empty)Free register list: R0, R1, R2, R3, R4, R5, R6, R7______________________________________
Assume now that task T1 (VALC A) is initiated. Task T1 requires no input from any of the top-of-stack registers, but requires one top-of-stack register for output A of task T1. Accordingly, the Task Controller TC assigns register R0 for output A. The state of the Processing Element PE thus becomes:
______________________________________Task mix: T1T1 input(s): None; T1 output(s): R0Top-of-stack list: R0Free register list R1, R2, R3, R4, R5, R6, R7______________________________________
The next task T2 (VALC B) likewise requires no top-of-stack register for input, but requires one top-of-stack register for output B of task T2. Accordingly, the Task Controller TC assigns register R1 for output B. The state of the Processing Element PE thus becomes:
______________________________________Task mix: T1 and T2T1 input(s): None; T1 output(s): R0T2 input(s): None: T2 output(s): R1Top-of-stack list: R0, R1Free register list R2, R3, R4, R5, R6, R7______________________________________
The next task T3 (ADD: S1=A+B) requires as inputs the A output of task T1 (in register R0) and the B output of task T2 (in register R1). Task T3 also requires one top-of-stack register for the output S1=A+B of task T3 for which the Task Controller TC assigns register R2. The state of PE now becomes:
______________________________________Task mix: T1, T2 and T3T1 input(s): None; T1 output(s): R0T2 input(s): None; T2 output(s): R1T3 input(s): R0, R1; T3 output(s): R2Top-of-stack list: R2Free register list: R3, R4, R5, R6, R7______________________________________
The next task T4 (ONE) requires no top-of-stack register for input, and one top-of-stack register for the "1" output of task T4 for which the Task Controller TC assigns register R3. The state of PE now becomes:
______________________________________Task mix: T1, T2, T3 and T4T1 input(s): None; T1 output(s): R0T2 input(s): None T2 output(s): R1T3 input(s): R0, R1; T3 output(s): R2T4 input(s): None; T4 output(s): R3Top-of-stack list: R2, R3Free register list R4, R5, R6, R7______________________________________
The next task T5 (VALC C) requires no top-of-stack register for input, but requires one top-of-stack register for output C of task T5 for which the Task Controller TC assigns register R4. The state of PE thus becomes:
______________________________________Task mix: T1, T2, T3, T4 and T5T1 input(s): None; T1 output(s): R0T2 input(s): None; T2 output(s): R1T3 input(s): R0, R1 T3 output(s): R2T4 input(s): None; T4 output(s): R3T5 input(s): None; T5 output(s): R4Top-of-stack list: R2, R3, R4Free register list: R5, R6, R7______________________________________
The next task T6 (ADD: S2=1+C) requires as inputs the "1" output of task T4 (in register R3) and the C output of task T5 (in register R4). Task T6 also requires one top-of-stack register for the output S2=(1+C) of task T6 for which the Task Controller TC assigns register R5. The state of PE becomes:
______________________________________Task mix: T1, T2, T3, T4, T5 and T6T1 input(s): None; T1 output(s): R0T2 input(s): None; T2 output(s): R1T3 input(s): R0, R1; T3 output(s): R2T4 input(s): None; T4 output(s): R3T5 input(s): None; T5 output(s): R4T6 input(s): R3, R4; T6 output(s): R5Top-of-stack list: R2, R5Free register list: R6, R7______________________________________
The final task T7 (SUBTRACT: S3=S1-S2) for this example requires as inputs the S1=(A+B) output of task T3 (in register R3) and the S2=(1+C) output of task T6 in register R5. Task T7 also requires a top-of-stack register for output S3=S1-S2 of task T7 which constitutes the result of this subtraction and (for which the Task Controller TC assigns register R6. The final state of PE for this example thus becomes:
______________________________________Task mix: T1, T2, T3, T4, T5, T6 and T7T1 input(s): None; T1 output(s): R0T2 input(s): None; T2 output(s): R1T3 input(s): R0, R1; T3 output(s): R2T4 input(s): None; T4 output(s): R3T5 input(s): None; T5 output(s): R4T6 input(s): R3, R4; T6 output(s): R5T7 input(s): R2, R5; T7 output(s): R6Top-of-stack list: R6Free register list: R7______________________________________
As an aid in understanding the above example, reference is directed to FIG. 5 which summarizes the above-described activity involved in the performance of the exemplary calculation (A+B)-(1+C). Note that tasks T1, T2, T4 and T5 have no mutual dependencies and, thus, their performance may be overlapped. The performance of tasks T3 and T6 may also be overlapped, while the performance of task T7 must wait for its inputs until they have been produced by tasks T3 and T6.
Termination of tasks
As each task is completed, the Task Controller TC records this occurrence by marking the task as having achieved end of task EOT.
When the Oldest Active Task (OAT) has reached (EOT) and its change queue entries have all been completed, it may be "terminated". To terminate a task, TC marks it as not active and advances the Oldest Active Task designation (OAT) to its successor. This termination of the oldest active task frees the Program Controller PC to insert another task if it was Waiting because of a full mix of tasks.
Register space allocated for "temporaries" is returned to the free list when a task reaches (EOT). However, register space for "inputs" is not returned to the free list until the task is actually terminated (this restriction improves the capability of restarting tasks in case of transient error conditions). Register space allocated for "outputs" is not returned directly to the free list. Output registers are added to the top-of-stack image and are used as inputs by subsequent tasks.
Multiple tasks per instruction
Typically, some of the high level instructions can be conveniently split into multiple tasks to be performed on the low-level processor. In this way, additional concurrency may be provided, and the overall performance of the system thereby improved.
Synchronization of changes to state
Aside from changes to the top of the stack, most other effects that an operator can cause are changes to state such as to main memory. These state changes are synchronized by means of two change queues, the Memory Change Queue and the Address and State Unit Change Queue. These change queues (which will be described in more detail hereinafter) impose three kinds of order on the otherwise unordered execution of tasks.
First, consider the case of two tasks, T1 and T3 where T1 logically precedes T3. If T1 were to abort (for example, T1 may be an Add operator and may detect an exponent overflow condition), then any state changes attempted by T3 must not be allowed to occur.
Second, consider the case in which T1 and T3 both are to write in the same location in memory, but neither task aborts. In this case, the final result (after the execution of T3) must be that the value written by T3 should be in that memory location.
Third, consider tasks T1, T2, T3, and T4 (in that logical order). As before, assume that T1 and T3 both write to the same memory location. Also assume that T2 and T4 both read from that same location. In such a case, T2 must get the value written by T1, and T4 must get the value written by T3, regardless of the actual order of execution of the tasks.
In all three of the above cases, the required synchronization is accomplished by the use of change queues. Each of these change queues typically provides storage for a small number of "entries" arranged in a first-in-first-out queue. Each entry keeps information on a single state change. The entries are inserted into the queues by tasks in order to effect changes to the state of the system; the entries are removed by the hardware as the changes are actually made. A change is actually made to the state only when the task which originated the change has become the Oldest Active Task (OAT).
In order to guarantee that the changes to state are made in the same order as the logical task sequence, entries are placed into a change queue one task at a time, which is enforced by providing a "lock" on each queue. The Program Controller PC assigns the necessary locks to each task upon initiation. The locks are released by the task when it has inserted all of its entries into the queues. The Program Controller PC must, of course, wait until the previous task has released a lock before assigning it to another task.
Each entry to the change queue typically includes (1) a new value for some piece of state, (2) an address of that piece of state, and (3) validity bits for each of these components. The entries in the queue may be incomplete, as indicated by their validity bits. The task which inserts the entry into the queue may supply the address and the value separately, in either order.
When a task attempts to read a portion of the state, the appropriate change queue is checked by the hardware, in the following manner:
1. If the change queue is locked by a preceding task, then the reading task is put into a Waiting state until it is unlocked. If it is locked by the reading task or by a succeeding task, then the reading task may continue with the next step;
2. If the change queue contains any entries belonging to preceding tasks which have invalid addresses, then the reading task is put into a Waiting state until they are made valid. Entries belonging to the reading task or its succeeding tasks are ignored;
3. If the change queue contains any entries belonging to preceding tasks which have valid addresses which match the address the reading task is trying to read, then the most recently entered entry which meets this condition is checked further. If this entry has a valid value component, then this value is returned to the reading task as the desired value. If this entry has an invalid value component, then the reading task is put into a Waiting state until it is made valid;
4. If none of the above conditions holds, then the task reads the state directly.
Discontinuation of tasks and "backing-up"
Under normal circumstances, the Program Controller PC and the Task Controller TC will attempt to keep as many tasks in the task "mix" as resources allow. Because error conditions typically occur only infrequently on a dynamic basis, PC and TC assume that error conditions will not occur and continue to initiate tasks. It is possible, therefore, that tasks may need to be discontinued if a logically preceding task detects an error condition after the initiation of its successor tasks.
Because changes to state are controlled by the change queues such that only the changes initiated by the Oldest Active Task (OAT) are ever actually made to state, it is relatively easy to discontinue unwanted tasks. All that is required is to remove them from the mix, delete their entries from the change queues (if any), and "back up" the register assignments to the point at which the error was detected.
Task Execution
As was pointed out previously, important features of the preferred embodiment of the invention being described herein reside in the employment of a multiple stage pipelined architecture whereby multiple tasks can be concurrently executed in a manner which permits advantage to be taken of both multiprogramming and multiprocessing techniques at a microinstruction level. A preferred manner for achieving these features in accordance with the invention will now be presented.
In the preferred embodiment of the invention, the implementation of the Processor Element PE in FIG. 3 is, for example, chosen to be such that a maximum of sixteen tasks may be active at one time. A preferred manner in which the Task Controller TC assigns resources for each activated task has already been described in connection with the exemplary calculation (A+B)-(1+C) summarized in FIG. 5. It has also been described in connection with FIG. 4 how the activated tasks are managed with respect to the one of four possible states--Ready, Waiting, Executing and End of Task (EOT)--in which each activated task may reside.
It will now be described how the preferred embodiment of the Processor Element PE provides for the concurrent execution of multiple activated tasks in a manner so as to achieve the advantages of both multiprogramming and multiprocessing at a microinstruction level. A first step in this regard is to provide for the performance of each task as a result of the sequential execution of a particular one or more task microinstructions accessed from the Stored Logic Controller SLC. For example, a task T 1 may be performed by executing three task microinstructions designated as T 1 m 1 , T 1 m 2 and T 1 m 3 . As will be evident from the previous description with regard to task management (e.g., see FIG. 4), task microinstructions may be executed in any order regardless of the particular task to which each corresponds. Thus, a single processor can provide multiprogramming on a microinstruction level, since, while one task is Waiting for a condition which will permit its first or next task microinstruction to be made Ready for execution by the Task Controller TC, the processor is able to go ahead and execute other task microinstructions which are Ready. For example, assume that the three tasks T 1 , T 2 and T 3 are active wherein: T 1 is a two-microinstruction task T 1 m 1 , T 1 m 2 requiring a wait between T 1 m 1 and T 1 m 2 ; T 2 is a three-microinstruction task T 2 m 1 , T 2 m 2 , T 2 m 3 requiring a wait between T 2 m 1 and T 2 m 2 ; and T 3 is a one-microinstruction task T 3 m which requires completion of task T 1 before it can be made Ready. A single processor is then able to provide execution in a multiprogramming manner by, for example, providing for executing these task microinstructions in the following sequence: T 1 m 1 , T 2 m 1 , T 1 m 2 , T 3 m 1 , T 2 m 2 , T 2 m 3 , as illustrated in FIG. 6. Preferably (and as indicated by the "Executing" circle in FIG. 4), when a particular task microinstruction is being executed, it is normally preferable to permit this task to continue and execute its next microinstruction, if Ready, even though other tasks may also have Ready microinstructions.
Having described how the preferred embodiment provides for the execution of task microinstructions using a single processor in a manner so as to take advantage of multiprogramming, it will next be described how multiprocessing is additionally provided in a particularly advantageous manner in accordance with the invention. Basically, this additional multiprocessing capability is achieved in the preferred embodiment by the employment of a three-stage pipeline architecture which is implemented so as to in effect provide three separate processors operating 120° out of phase and sharing the same physical hardware. In order to take advantage of this 3-processor implementation the preferred embodiment not only provides for multiprogramming (as described above) by permitting task microinstructions from different tasks to be executed in intermixed fashion, but also, the preferred embodiment advantageously provides for multiprocessing by permitting a Ready task microinstruction to be selected for execution by any one of the three processors.
The preferred embodiment achieves this combined multiprogramming and multiprocessing of task microinstructions by providing an implementation having the following characteristics (1) and (2) set forth below:
(1) Provision is made for implementing SLC, DP and ASU in FIG. 3 so that the execution of each task microinstruction is performed in three stages requiring three consecutive clock periods. Typical 3-stage operation is such that, in the first clock period (first stage) of a task microinstruction, a Read operation is performed to prepare for execution of a selected microinstruction which includes reading out from storage the appropriate operand data to be used during microinstruction execution and also reading out the condition select data for use in determining the next microinstruction address. In addition, during this first clock period, appropriate fields of the microinstruction are used to derive control signals for use in controlling data path functions during the second clock period. In the second clock period (second stage) of a task microinstruction, a Compute operation is performed during which the selected microinstruction is executed and the selected conditions are tested to produce next microinstruction data. During the third clock period (third stage) of a task microinstruction, a Write operation is performed during which the results of microinstruction execution are written into storage and the next microinstruction data is used by the Task Controller to select the microinstruction to be performed during the next clock period.
(2) In addition to the characteristics set forth in (1) above, the preferred embodiment also provides for the concurrent performance during each clock period of a Read operation for a first task microinstruction, a Compute operation for a second task microinstruction, and a Write operation for a third task microinstruction, whereby to achieve the effect of three different task microinstructions being concurrently performed by three different processors operating 120° out of phase with one another, as illustrated in FIG. 7 for task microinstructions T x m 1 , T y m 1 and T z m 1 . The three-stage Read, Compute and Write operations respectively occurring for each task microinstruction in three consecutive clock periods (as described in (1) above) are respectively indicated in FIG. 7 by the letters R, C and W.
The multiprogramming capability illustrated in FIG. 6 for a single processor is utilized in the preferred embodiment in conjunction with the 3-processor multiprocessing capability illustrated in FIG. 7 so as to permit task microinstructions to be performed in a particularly expeditious manner which takes advantage of both capabilities. FIG. 8, for example, illustrates the performance of the three calculations (A+B)+(C+D)=H; (A+B)-E=I; and (C+D)-E=J using, for example, ten tasks T A through T J assigned by the Task Controller TC as follows:
______________________________________Tasks Operators______________________________________T.sub.A = T.sub.A m.sub.1 w T.sub.A m.sub.2 VALC AT.sub.B = T.sub.B m.sub.1 w T.sub.B m.sub.2 VALC BT.sub.C = T.sub.C m.sub.1 w T.sub.C m.sub.2 VALC CT.sub.D = T.sub.D m.sub.1 w T.sub.D m.sub.2 VALC DT.sub.E = T.sub.E m.sub.1 w T.sub.E m.sub.2 VALC ET.sub.F = T.sub.F m ADD (A + B) = FT.sub.G = T.sub.G m ADD (C + D) = GT.sub.H = T.sub.H m SUBTRACT F - G = HT.sub.I = T.sub.I m SUBTRACT F - E = IT.sub.J = T.sub.J m SUBTRACT G - E = J______________________________________
It is assumed for the example shown in FIG. 8 that the "operand fetch" tasks T A -T E each require two task microinstructions with at least a three clock wait period (indicated by "w" above) therebetween. It is also assumed that each of the "ADD" and "SUBTRACT" tasks T F -T J require only one clock period (indicated above and in FIG. 8 by "m" having no subscript). Also note in FIG. 8 that a "No-Op" microinstruction is provided when there are no Ready task microinstructions.
DETAILED DESCRIPTION
The construction and arrangement of the preferred embodiment of the present invention will now be considered in more detail with reference to particular preferred implementations.
Program Controller PC (FIGS. 3 and 9)
As described previously in connection with FIG. 3, the Program Controller PC accesses program code words from the Memory System MS (FIG. 2), parses them into operators, and then decodes each operator to determine one or more tasks to be performed along with the resource requirements for each task. This decoded information, including a unique microinstruction entry address for the Stored Logic Controller SLC, is passed to the Task Controller TC so that a task may be assigned and initiated to perform each operator. At the same time, operator parameters, if any, are passed directly to the Main Data Path DP. Since the Task Controller TC manages the actual execution of tasks and coordinates multiple tasks, PC is free to scan ahead in the code stream, thereby minimizing the effect of its operations on processor performance.
In a preferred implementation, the Program Controller PC provides the following major functions:
1. Program word buffering.
2. Program word indexing.
3. Maintaining back-up for program indexing.
4. Operator decoding and parameter handling (Operator Decoder OD).
5. Program Controller and Task Controller HOLD/GO control.
6. Pseudo-opcode generating.
7. Initiating routines to handle external interrupt and alarm error conditions.
The manner in which the above functions are provided in a preferred implementation of PC will now be described with particular reference to FIG. 9.
Program Word Buffering
The Program Controller PC provides two program buffer registers P and Q for program word handling. Associated with each is a "register occupied flag", PROF and QROF, respectively. The P and Q registers can be indexed and the appropriate operator and parameter syllables selected. The "next" program word is pre-fetched into Q concurrently with decoding from P.
Program Word Indexing
PC has a Program Word Index Register PWI and a Program Syllable Index Register PSI which together function as a program counter. PSI, for example, may select using a Syllable Selector SS one of six opcode syllables from a program word in P for decoding by an Operator Decoder OD. When a word boundary is crossed, the "next" program word in Q is transferred to P, PWI is incremented, and a "Fetch" request is sent to the Address and State Unit ASU (FIG. 3). The output of PSI is also provided to ASU to calculate a memory address and initiate a memory read. When the new program word is loaded into Q, QROF is set by the memory. PWI and PSI can be loaded with different values (for program branching, etc.) from the Main Data Path DP (FIG. 3).
Program Index Backup File (PIBF)
Because of the multi-tasking capability provided in accordance with the invention, the performance of the tasks corresponding to one or more operators may sometimes have to be discontinued after they have been initiated. PC is thus provided with the capability of backing-up in the program stream, i.e., to return PWI/PSI to a previous value and to initiate a Fetch if PWI no longer points to the current program word. To effect this, PC provides a Program Index Backup File PIBF (FIG. 9) which records the values of PWI and PSI for all tasks. Upon receiving a back-up indication from TC, PC enters a HOLD state while reading PIBF to obtain the values of PWI and PSI which pointed to the syllable corresponding to the task causing the back-up. The PWI and PSI registers are then loaded with these values. An executing task has the capability of reading PIBF to obtain the values of PWI and PSI which existed at the time of its initiation.
Operator Decoding and Parameter Selection
The opcode syllable indexed by PSI is decoded by the Operator Decoder OD (FIG. 9) which typically yields operator characteristics such as:
1. The number by which PSI must be incremented to point to the next opcode syllable.
2. The number of succeeding syllables which are to be used as operator parameters.
3. Whether or not the operator is one of certain special operators which require special handling.
4. Whether or not PC should HOLD after initiating a task for the operator.
5. Whether or not the operator can be entered in Restart mode (thereby providing a pseudo-opcode for that purpose).
6. Task setup information and resource requirements.
Parameters
Parameters are selected from the output of the Syllable Selector SS in FIG. 9. After appropriate formatting by a Parameter Handler PH, the parameters are transferred to the Main Data Path DP (FIG. 3).
Restart Mode
A "Restart" flag in the Program Controller PC can be set from the Stored Logic Controller SLC (FIG. 3). It remains set until the next occurrence of a legitimate operator in which case it is reset and that operator is initiated in "Restart Mode" (accomplished by temporarily entering HOLD state and substituting a pseudo-opcode for the original opcode.)
Task Setup Information
The following information is typically provided to initiate a task for an operator and is passed to the Task Controller TC (FIG. 3) via the Task Setup Register (FIG. 9) TSR to which the output of the Operator Decoder OD is applied.
1. The number of inputs to be consumed from the stack controlled by the Task Controller TC.
2. The number of output and temporary registers to be assigned.
3. Initial WAIT condition--whether or not the task should wait for the topmost stack register to become valid before being made ready for execution.
4. Alternate WAIT condition--whether or not the task should wait on the "earliest of two registers" (the two topmost stack registers) to become valid.
5. Whether or not the task should be given priority in being selected for execution.
6. Whether or not the stack should be adjusted so that only the task's inputs are in the top-of-stack.
7. Whether or not the task changes "state".
8. Whether or not the task belongs to a set representing a multi-task operator.
9. Whether or not the task represents a pseudo-operator.
10. Initial Task Microinstruction Address ITCA for SLC (FIG. 3).
11. ASU Change Queue ACQ lock request.
12. Memory Change Queue MCQ lock request.
HOLD/GO Control
As described previously, the Program Controller PC and Task Controller TC (FIG. 3) work in tandem to generate a continuous stream of tasks to be performed. As also described previously, PC determines the characteristics of a task and loads this information into the Task Setup Register TSR (FIG. 9). Further responsibility is then assumed by TC, including the assignment of an actual task number and initiation of the task.
A number of conditions can prevent immediate initiation of a task using the information in TSR. Consequently, PC has the capability of placing itself and TC in a HOLD state. These conditions are:
1. Waiting for a program word fetch.
2. HOLD signal from SLC or Operator Decoder OD.
3. PC detects an external interrupt or alarm error and must insert a pseudo-op to handle it.
Other conditions, originating in TC, may also prevent immediate initiation of a task. These conditions are:
4. The number of output and temporary registers required for the next task (as specified by TSR) is greater than the number of registers available. (HOLD condition will persist until a currently active task releases some of its registers).
5. The number of outputs which the next task will place on the stack, after allowing for the inputs used by the task, is greater than the number of unoccupied positions in the Top of Stack List. (HOLD while PC inserts a "push task.")
6. The number of inputs required by the next task is greater than the number of entries in the Top of Stack List. (HOLD while the PC inserts a "pop task.")
7. The next task requires that only its inputs be in the Top-of-Stack. (HOLD while PC inserts a "push" or "pop task.")
8. TC has reached its limit for concurrent tasks. (HOLD until a task terminates.)
9. An ACQ lock request occurs and the ASU Change Queue is locked.
10. An MCQ lock request occurs and the Memory Change Queue is locked.
Pseudo-Opcode Generation
Pseudo-ops may be inserted into the code stream by a Pseudo-Opcode Generator POG (FIG. 9) or independently by an SLC microinstruction. PC will use pseudo-ops to perform control functions such as stack push/pop and interrupt handling. Pseudo-ops may also be used for functions such as handling operator-dependent interrupts and generating other than the first task of multi-task operators.
The pseudo-opcode is either generated internally by POG based on the specific function to be performed or obtained from DP upon receipt of an appropriate SLC microinstruction. When a pseudo-op is to be inserted, the HOLD state is first invoked. This prevents a task from being initiated using the setup information currently in TSR. Selection (for operator decoding) of the opcode syllable indexed by PSI is over-ridden by selection of the pseudo-syllable. New setup information is loaded into TSR, HOLD is removed and a task is initiated. The pseudo-op does not increment PSI so TSR is again loaded with setup information for the operator which was preempted by the pseudo-op. If no further HOLD condition exists, task initiation then proceeds in the usual manner.
For certain sequences of operators, the insertion of a pseudo-op is not permitted. For example, insertion of a pseudo-op is not permitted when PC has been placed in a HOLD state by SLC or by the HOLD output of the Operator Decoder OD. This insures the correctness of the PWI/PSI values which are associated with the pseudo-op by preventing insertion in such situations as (1) while PWI/PSI are being changed--due to a branching operator, or (2) between the separate tasks of a multi-task operator. (Operators which cause unconditional branching invoke the HOLD state at initiation time via TSR, as does the first task of a multi-task set; conditional branching operators may invoke a HOLD state using an SLC microinstruction).
Task Controller (TC) (FIGS. 3 and 10)
The Task Controller TC assigns a task in response to the task data or pseudo-operator supplied by the Program Controller PC. It manages the utilization of processor resources in such a way as to achieve a high level of concurrency of operator execution, while maintaining sequential order where required. The Task Controller TC coordinates the execution of numerous tasks in various stages of completion so that no task is unnecessarily delayed when resources are available for its independent operations.
The major functions of the Task Controller TC are set forth below:
1. Register allocation
2. Top-of-Stack control
3. Task initiation
4. Task termination
5. HDP task initiation and termination
6. Discontinuing successor tasks (back-up)
7. Task Wait conditions and Ready task selection
8. Microinstruction address selection
The manner in which the above functions are provided in a preferred implementation of TC will now be described with particular reference to FIG. 10.
Register Allocation
As generally described previously, the Main Data Path DP (FIG. 3) of the Processing Element PE contains pairs of working registers which may be allocated to tasks according to their needs, the number of input, output, and temporary registers required by a task being specified by the Program Controller PC via the Task Setup Register TSR (FIG. 9). The Task Controller TC maintains a register allocation list in a Register Allocation File RALF (FIG. 10) which dynamically tracks the register use status (registers assigned vs. free registers available). More specifically, TC first determines if there are enough free registers available to meet the needs of the next task. If so, TC then performs the following functions:
1. Assigns the required number of registers for outputs and temporaries while selecting the proper number of inputs from the Top-Of-Stack, the specific assignments then being written into the Register Map RMAP of DP (FIG. 14);
2. Records the register use status as it existed prior to initiation of the task by writing the register allocation list into the Register Allocation File RALF (for "back-up" purposes); and
3. Updates the register allocation list to provide current status to a subsequent task.
If, on the other hand, there are not enough free registers, TC is then placed in a HOLD state until enough registers become available, while PC is also signalled to HOLD.
The registers assigned to a task by TC are de-allocated (by updating the register allocation list) at two different times. Temporary registers are released when the task reaches the "EOT" condition and inputs are released when the task is terminated. Output registers, however, are passed to a successor task as its inputs (by adding them to the Top-Of-Stack) and reassigned to that task via RMAP of DP (FIG. 14).
Top-of-Stack Control
The Top-Of-Stack TOS is formed by a dynamically-allocated group of registers in RALF of the Main Data Path DP (FIG. 14) which is a logical extension of the in-memory stack of the process currently being executed. Registers designated as being in the Top-Of-Stack will previously have been assigned by the register allocation mechanism.
The Top-Of-Stack TOS may typically comprise seven registers. TC updates TOS each time a new task is initiated based on the number of inputs and outputs which are specified by PC via the Task Setup Register TSR (FIG. 10). A task's inputs are obtained from TOS and its outputs placed in TOS ("push" and "pop" tasks are unlike other tasks in that they access the bottom-most entry in the top-of-stack).
TC includes a Top-Of-Stack Control TOSC (FIG. 10) which dynamically tracks the Top-Of-Stack status by maintaining a TOS list and a TOS number. The TOS list is a list of the registers currently in TOS, while the TOS number indicates the number of registers currently in TOS. TC uses the TOS list and TOS number to determine if all the inputs for the next task are in TOS. If so, these input registers are provided to RMAP (FIG. 14) in DP for assignment. If all inputs are not in TOS, TC is placed in a HOLD state and PC is signalled that a "pop task" must be inserted before the corresponding task can be initiated. If a task will leave more outputs on the stack than it will consume inputs, TC determines if the Top-Of-Stack limit will be exceeded. If so, TC is placed in a HOLD state and PC is signalled that a "push task" must be inserted.
For back-up purposes, TC also functions to maintain a record of the status of TOS as it existed prior to initiation of the task by writing the TOS list and TOS number into a TOS file contained in TOSC (FIG. 10), while also updating the TOS list and TOS number to provide current status to a subsequent task.
When a push or pop task is inserted, PC and TC are released from HOLD state. Since HOLD prevents PSI (FIG. 9) from being incremented, a second attempt is made to initiate a task for the operator. It is again subject to the previously described conditions and additional push or pop tasks may be inserted. (Note that each push task removes one register from the top-of-stack and each pop task adds one register).
Task Initiation
When an operator's characteristics are specified by the Task Setup Register TSR of PC (FIG. 9), the "next" task, as it has been previously referred to, is really only a potential next task. It is only when it has been determined that the necessary resources are available and that no HOLD condition exists does the potential next task become the actual next task and is referred to thereafter as the "initiated task". Sometimes a potential next task turns out not to be the next task at all, as in the case where a HOLD is imposed and tasks are inserted to perform pseudo-ops.
When a task is initiated, it is assigned a task number. The limit on the number of concurrent tasks may, for example, be 16. Task numbers are typically assigned to "ordinary tasks" on a "round-robin" basis. All such tasks (excluding HDP and null) are subject to order-of-precedence. This order is insured by also maintaining a record of the "Oldest Active Task" OAT. The successor/predecessor relationship between any two tasks can, for example, be determined by comparing their task numbers A and B with OAT as follows: ##EQU1##
The Task Controller TC in FIG. 10 also includes an Initiation Task Register ITR which contains the number of the task which was initiated on the previous clock. ITR operates to address a Next Address Register File NARF for writing in the initial task microinstruction address for the task just initiated. ITR also addresses the Register Map RMAP in DP (FIG. 14) for recording register assignments, and also addresses a Special Purpose Register File SPRF in DP for recording parameters (extracted from the code stream) which are to be associated with the task just initiated.
The Task Controller TC in FIG. 10 additionally maintains a Valid Task File VALT which keeps track of which tasks have been initiated and are in some stage of completion. When the task limit has been reached, a HOLD condition will exist in TC and be signalled to PC, preventing further initiation of tasks until a task terminates.
At initiation time, TC may also record certain special characteristics of each task obtained from PC which become pertinent, for example, when tasks are being discontinued. Such characteristics may, for example, indicate whether or not the task changes "state" information, and whether or not the task is a member of a set representing a multi-task operator.
Task Termination
A task is terminated by marking it "not valid" in the Valid Task File VALT (FIG. 10). Before a task can be terminated it must satisfy the following conditions:
1. The task must have reached End-Of-Task (EOT) and signalled that condition by an SLC microinstruction.
2. The task must be the Oldest Active Task (OAT), to insure the sequential order of the program segment being performed.
3. The task must have no entries in the Change Queue of ASU (FIGS. 3 and 15) and MS (FIGS. 2 and 17) for which a write has not been initiated.
When the above three conditions are satisfied, the task is marked "not valid", input registers are returned to the pool of free registers, the loop timer is reset, and the immediate successor of (OAT) becomes the new (OAT).
HDP Task Initiation and Termination
When an HDP task from HDP (FIG. 2) is inserted into the mix by PC, it is initiated in the usual way by TC with the exception that it is always assigned a predetermined task number. If the HDP task is already valid, no action will occur. The HDP task will remain valid until it is terminated by TC. Termination is not subject to the same conditions as for ordinary tasks with respect to (OAT) and the change queues. Reaching (EOT) is all that is required.
Discontinuing Successor Tasks ("Back-up")
At some point in the performance of a particular task, a situation may occur which renders the results of successor tasks incorrect or unnecessary (e.g., operator-dependent interrupts or assumed branch paths not taken). When this happens, a task will communicate its intention to discontinue successor tasks by requesting a DS lock provided in TC. If the DS lock is already locked, the task will be "put to sleep" until the lock is free. The task which has the lock (DS lock owner) will cause TC to perform the following actions by the command DS successors:
1. Go into HOLD state and signal PC to HOLD also; put all tasks to sleep (HDP task excluded).
2. Discontinue all successors of the DS lock owner (by marking them "not valid" in the Valid Task File VALT (FIG. 10) and signalling other controllers to do likewise.
3. Reset (EOT) flags of all discontinued tasks.
4. Back-up the Register Allocation List RALL (FIG. 10) to indicate the register use status just before the DS lock owner was initiated.
5. Back-up the TOS list and the TOS number maintained by TOSL (FIG. 10) to indicate the Top-Of-Stack status just before the DS lock owner was initiated.
6. Signal PC to back-up PWI and PSI by loading from PIBF (FIG. 9).
7. Make the "next task" to be initiated the immediate successor of the DS lock owner (i.e., set the Next Address Register File NARF (FIG. 7) to the appropriate successor task number).
8. Free the DS lock and wake up tasks.
The actions which result from DS lock and DS successors (and all other SLC microinstructions as well) are inhibited if a present cycle abort is indicated. Tasks may also be discontinued by TC as a result of an error. In this circumstance, TC will use the DS lock to prevent conflict. If the DS lock is already locked, TC will wait until the lock is free.
Task Wait Conditions and Ready Task Selection
Once a task has been initiated, it is made Ready for performance unconditionally, if no initial Wait condition is specified, or conditionally, if an "initial Wait condition" or "alternate Wait condition" is invoked via the Task Setup Register TSR (FIG. 9). The initial Wait condition is the validity of the task's input register which is topmost on the stack. The alternate Wait condition is that of waiting on the "earliest of two" input registers (the two topmost on the stack) to become valid. If the register specified by the initial or alternate Wait condition is valid at initiation time, or if no initial Wait condition was specified, the task is Ready and may be selected for execution. The "validity" of each register is indicated by a stack item available flag which is located in TC. After a task has been selected for performance, it may at any time be put into the Wait state ("put to sleep") either explicitly by a microinstruction or implicitly by hardware conditions which exist at the time a microinstruction is executed.
Typical explicit Wait conditions are:
1. Memory-complete--Each task has its own MAC (Memory Action Complete flag) which is set when a memory operation has been successfully completed.
2. Myself-equal-OAT--Wait until task is the Oldest Active Task OAT.
3. HDP-complete--Wait until HDP (FIG. 2) has completed an independent operation in progress. (This Wait condition applies to HDP task only).
Typical implicit Wait conditions are:
1. ACQ-change--Wait until the ASU Change Queue ASU-CQ (FIG. 15) has changed states. (This Wait condition is invoked dynamically if a task attempts to get a slot in ASU-CQ and a slot is not available.
2. MCQ-slot-available--Wait until slot is available in the Memory Change Queue MCQ (FIG. 17).
3. DS lock-free--Wait until the DS lock (provided by TC) is not locked.
Special Wait condition:
If a task has not been put to sleep, it remains Ready and may be selected for performance. A task will receive priority over other Ready tasks if priority was specified via the Task Setup Register TSR (FIG. 9). From the set of all Ready tasks of equal priority, one task microinstruction is selected for execution during each clock period that the processor is not halted. Since execution of a task microinstruction requires multiple clock cycles (see FIG. 7), TC marks the selected task as "in execution" to prevent selecting it again on the next clock cycle. Whenever there are no Ready tasks and the processor is not halted, the null task microinstruction is selected and is equivalent to a No-Op.
Microinstruction Address Selection
When a task microinstruction is selected, a microinstruction address is read out of the Next Address Register File NARF (FIG. 10) and sent to the Stored Logic Controller SLC (FIG. 3). For the first microinstruction of a task, this address will be the initial task microinstruction address recorded at initiation time. During the Write clock period (see FIG. 9) of each task microinstruction, a next selected address is determined by SLC and sent back to TC to replace the previous address in NARF (FIG. 10). NARF is best thought of as a file of microinstruction address registers, one per task, which is used in implementing multiprogramming in accordance with the invention.
In addition to storing the next selected microinstruction address in NARF for an executing task, TC also places it in an Address Recycle Register ARR (FIG. 10). This register is used for optimization purposes and allows for overriding the Ready task selection operations performed by a Ready Task Selector RTS (FIG. 10) to give an executing task top priority to continue to the next task microinstruction as long as it does not encounter a Wait condition. After examining Wait conditions during each clock cycle, TC selects the next microinstruction address either from ARR for the current task (if Ready), or from NARF for a Ready microinstruction of a different task.
When no task is currently being performed and no other task microinstructions are in the Ready state, the null task is selected, as previously mentioned. The null task addresses the slot in NARF which is loaded with the microinstruction address provided at system initialization time. This address corresponds to a microinstruction which performs a No-Op function with respect to the code stream being processed by PC. However, if desired the null task could be used to perform some system control or monitoring function.
The Stored Logic Controller SLC (FIGS. 3 and 11-15)
The Stored Logic Controller SLC is that part of the Processing Element PE (FIG. 3) which contains the task microinstructions and uses these microinstructions to control the performance of the other parts of the processor as required for performing each task. SLC typically comprises a Microinstruction Memory MM (FIG. 11), a Microinstruction Register MR for receiving microinstructions read out from MM, a Sequence Control Memory SCM (FIGS. 11 and 13), an Auxiliary Control Memory ACM, a Next Address Selector NAS, and a Subroutine Control Circuit SCC.
The Microinstruction Memory MM may, for example, be a random access memory containing stored microinstructions. The Sequence Control Memory SCM is a logical extension of MM and contains branching information respectively corresponding to microinstructions stored in MM. (For example, see the aforementioned U.S. Pat. No. 4,155,120). The Auxiliary Control Memory ACM typically contains mask and rotate values for the Main Data Path DP (FIG. 14). These values may be selected statically, by addresses from MM, or dynamically, by addresses obtained from DP.
The Next Address Selector NAS operates to determine the next microinstruction address in response to sampling selected conditions indicative of the state of the rest of the processor. Both conditional and unconditional dynamic and static branching are typically performed.
The Subroutine Control Circuit SCC permits efficient sharing of microinstruction subroutines. It may typically comprise a stack of microinstruction addresses. A subroutine is "entered" by pushing the present microinstruction address plus an offset onto the subroutine stack and branching to the first instruction of the subroutine. A subroutine is "exited" by branching to the microinstruction address on top of the subroutine stack and popping that address from the stack.
The various components of SLC will now be considered in further detail.
Microinstruction Memory (FIG. 11)
During the Write operation performed during the terminal portion of each clock cycle, Microinstruction Memory MM (in response to a microinstruction address provided by TC) reads out a selected task microinstruction into the Microinstruction Register MR for use in the next clock cycle. A microinstruction typically comprises a series of control fields which provide control signals to various portions of the processor during task execution.
Auxiliary Control Memory ACM (FIGS. 11 and 12)
As illustrated in FIG. 12, the Auxiliary Control Memory ACM typically comprises various control devices and associated registers. During the Read operation portion of each clock cycle, these control devices receive patterns (from MR and other registers) for use in controlling various functions of the Main Data Path DP (FIGS. 3 and 14) during the next following Compute operation portion of the clock cycle. These control devices are addressed during the Read operation by multiplexing fields from the Microinstruction Register MR (FIG. 11) (static) and also by fields from Special Purpose Registers SPR (dynamic) contained in the Main Data Path DP (FIG. 14).
G and H Rotate and Mask Stores GHS (FIG. 12)
The G and H Rotate Stores GHS of ACS supply rotate values and mask patterns for DP (FIG. 14) and are addressed by either a field from MR (FIG. 11) (static), or by a field from the DP's SPR (dynamic).
N Bus Mask Store NMS (FIG. 12)
The N Bus Mask Store NMS contains patterns to control masking into the Data Register File DRF in DP (FIG. 14). The N Bus Mask Store NMS is addressed (via an N Mask Address Register NMAR) by a field from MR (static) or directly by a field from the DP's SPR (dynamic).
SPR Mode Control Store MCS (FIG. 12)
The SPR Mode Control Store MCS is addressed by a field in MR and contains the patterns to control SPR mode operations in DP (FIG. 14) and also the selection of data to be applied thereto.
Sequence Control Memory SCM (FIGS. 11 and 13)
The Sequence Control Memory SCM contains sequencing information for use in determining which microinstruction in the Microinstruction Memory MM (FIG. 11) will be executed next. More detailed information with regard to such means is disclosed in the aforementioned U.S. Pat. No. 4,155,120. SCM is addressed by an address field contained in a microinstruction residing in the Microinstruction Register MR (FIG. 11). The addressed information from SCM is read into a Sequence Control Register SCR. This information from SCM typically comprises an Alternate Address field ALTA, a Branch Address Index field BAI, and a Condition Select field CS which, as indicated in FIG. 13, are read into respective registers ALTA, BAI and CS.
Next Address Selector NAS (FIG. 11)
The Next Address Selector NAS is used in determining the next microinstruction address. During the Compute operation of each clock cycle, NAS uses the Condition Select field in CS (FIG. 13) to select four possible branch conditions from the many possible branch conditions applied to NAS from other parts of the Processing Element. The actual values of these four selected branch conditions are concatenated together to form a four-bit value which is used to select one of 16 subfields from the Branch Address Index field in BAI (FIG. 13). Each subfield contains a branch address index and a present cycle abort indication. The branch address index of the selected subfield is in turn used to select one of eight next microinstruction addresses, four of which are provided by ALTA (FIG. 13). NAS applies the selected next microinstruction address to the Next Address Register File NARF in TC (FIG. 10). Then, during the next following Write operation in the current clock cycle, this selected next address determined during the Compute portion of the clock cycle is used to address the Microinstruction Memory MM (FIG. 11) so as to read out into MR the selected microinstruction to be used in the next cycle.
Present Cycle Abort
The Stored Logic Controller SLC (FIG. 10) contains a feature to prevent the execution of a microinstruction if the conditions of the hardware are not as were expected. For example, when attempting to add two single precision operands, if one turns out to be double precision, SLC will indicate a Present Cycle Abort and select one of the alternate addresses provided by ALTA (FIG. 13) rather than continue in the expected sequence. This action is referred to as static Present Cycle Abort and is determined by the microinstruction. Other conditions can also cause a microinstruction to abort for example, when execution of an add microinstruction occurs and one of the registers expected to contain an operand is not valid. In this case the present address will be used as the next MM address and thus allow the microinstruction to be re-executed. This is referred to as dynamic Present Cycle Abort. If static and dynamic Present Cycle Abort occur simultaneously, the static abort will take precedence.
Subroutine Control Circuit (FIG. 11)
The Subroutine Control Circuit SCC of SLC provides for sharing common microinstruction sequences (subroutines). Multi-level subroutine structure is allowed by utilizing a stack which may typically accommodate as many as 15 levels of entry. A stack is used to store the subroutine return address. Typically 16 stacks may be provided, one for each task.
The Main Data Path DP (FIGS. 3 and 14)
The purpose of the main Data Path DP is to store the primary data items for all of the tasks in the mix and to perform the logical and arithmetic operations on these data items during the Compute operation portion of each clock cycle in response to the applicable microinstruction fields. DP typically comprises a Data Register File DRF for storing data (including top-of-stack data), a Utility Register File URF for storing input/output data, a Register Mapper RMAP for converting task-relative addresses for DRF into absolute addresses according to register assignments made by the Task Controller TC (FIG. 10), an Arithmetic Logic Unit ALU for performing arithmetic and logical operations on applied data, and Special Purpose Registers SPR for auxiliary counting and data-manipulation functions.
During a clock cycle typical operation of DP is as follows. During the initial Read operation portion of the clock cycle, two words in DRF (selected by appropriate microinstruction fields in MR (FIG. 11)) are accessed, appropriately aligned and masked, and then applied to ALU. During the next following Compute operation portion of the cycle, ALU performs arithmetic and/or logical operations on the applied words as determined by control signals from ACM (FIGS. 11 and 12) of SLC and also from SPR. During the terminating Write operation portion of the clock cycle, the results provided by ALU are written back, via the N-Bus, into DRF and/or applied to other units, such as MS, HDP, or HCP (FIG. 2).
Data Register File DRF (FIG. 14)
DRF may typically be a random access memory having an Address input, two read ports (G-Bus and H-Bus), one write port for N-Bus input data, and also an input for Memory data, each addressed independently via a microinstruction from SLC. To facilitate the manipulation of partial fields within a word of data, rotation and masking facilities are provided for the G-Bus and H-Bus outputs of DRF, and write-control masking is provided for the Write port of DRF. In addition, the Write port of DRF typically includes an associated write-control mask facility which allows only selected bits of an ALU result word to be written, all other bits of the addressed word in DRF remaining unchanged.
Register Mapper RMAP (FIG. 14)
The Register Mapper RMAP is used to convert the logical register addresses used by a microinstruction to the physical register addresses that have been assigned to a task. The register assignments for a task being initiated are generated by the Task Controller TC (FIG. 10) and written into a task number associated location in RMAP.
When a Task is selected by the Task Controller TC, its task number is used to index into RMAP to obtain the addresses of its physical registers in DRF.
Utility Register File URF (FIG. 14)
The Utility Register File URF is used to hold data from HDP (FIG. 2) and other non-task-dependent data. Typically, three write ports are provided into URF, one for N-Bus data, one for HDP data, and one for HCP data. SLC, via the N-Bus, supplies a URF address, which is used for both reading and writing.
Arithmetic Logic Unit ALU (FIG. 14)
The Arithmetic Logic Unit ALU performs arithmetic and/or logical operations on the data appearing on its G-Bus and H-Bus inputs during the Compute operation portion of a clock cycle and applies the result to the N-Bus.
Special Purpose Registers SPR (FIG. 14)
The Special Purpose Registers SPR in DP are used (among other purposes) for storing those data items on which dynamic fields are dependent. Under control of SLC, selected portions of SPR can be used to control rotation and/or masking (including write-control masking) independently for the three ports of DRF.
Data items are loaded into SPR from ALU, and the data in SPR may be used as one of the ALU inputs. In addition, SPR may provide various counting and shifting operations which can be applied to it concurrently with other operations of DP. This allows temporary data values such as loop counters to be stored in SPR, with loop control functions (such as decrementing and testing for zero) performed concurrently with the loop body. The operations applied to the contents of SPR during each clock cycle are determined by the applicable microinstruction. SPR may also be used for a variety of other functions. For example, it may supply new microinstruction addresses to PC (FIG. 9) when high-level branching operations occur, and it may also supply a value to SLC (FIG. 11) which can be used for low-level dynamic branching.
The Special Purpose Registers SPR may typically comprise three separate register files, one for use in each of the three Read, Compute and Write operations (stages 1, 2, and 3, respectively) occurring during a clock cycle. The Stage 1 SPR Register File may contain, for example, 16 register locations, each register being keyed to a task number. The Program Controller PC (FIG. 9), when decoding an OP, will also decode the parameters from the program word. These parameters are written into the Stage 1 SPR Register File by TC (FIG. 10) when the task is initiated. Data may also be written into the Stage 1 SPR Register File from the SPR files of other stages.
When a Ready Task is selected from the Task Controller TC (FIG. 10), its task number is used to index into the Stage 1 SPR Register File in order to read its parameters or data (if any). During Stage 1 (Read operation), SPR data is routed to the Address and State Unit ASU (FIGS. 3 and 15) for register addressing, to SLC (FIG. 11) for dynamic addressing for the G/H Rotate and Mask stores of ACM, and also for dynamic branching. During Stage 2 (Computer operation), SPR data is applied as input to ALU of DP (FIG. 14) and to SLC (FIG. 11) for dynamic N-mask addressing.
The Stage 3 SPR has internal rotate, count, and shift capabilities. These are used to process the data kept in SPR. This processing is controlled by SLC. Stage 3 SPR data is routed during a Write operation (Stage 3) to PC (FIG. 9) for use as pseudo-OPs and for setting PWI and PSI, and is also routed to the Stage 1 SPR. Also available from the Stage 3 SPR are certain late conditions which are generated after the SPR Stage 3 operation has been completed, and are routed to SLC for use as branch conditions in the next cycle.
Address and State Unit ASU (FIG. 15)
A primary purpose of the Address and State Unit ASU is to calculate and check addresses and to store these addresses along with other state values of the high-level architecture in an ASU register file ASU-RF. The storing into ASU-RF is controlled through an ASU Change Queue ASU-CQ to insure proper updating and sequencing. ASU also includes an ASU Arithmetic Logic Unit ASU-ALU for performing address calculations, a Limit Checker LC for making address calculation limit checks, and an Address Decoupler AD for performing decoupling functions. Typical types of address computations performed by ASU are as follows:
1. Address computations from "address couples".
2. Address computations of the form "base+offset", where the base address is a piece of state stored in ASU and the offset is either a small literal value or a value provided by DP (FIG. 14).
3. Address computations of the form "base+offset", where the base address and offset are provided by DP.
4. Address computations of the form "base+offset" for PC (FIG. 9), where the base address is a piece of state stored in ASU and the offset is provided by the PC.
Address Decoupler AD (FIG. 15)
The Address Decoupler AD uses SPR data from the Main Data Path DP (FIG. 14) to perform computations on address couples for providing an index value to the ASU Arithmetic Logic Unit ASU-ALU.
ASU Register File ASU-RF and ASU Change Queue ASU-CQ (FIG. 15)
The ASU Register File ASU-RF is used to hold various states and/or registers. All changes to ASU-RF are queued through the ASU Change Queue ASU-CQ. Any time a task wishes to access data in ASU-RF the state of ASU-CQ is checked. When a task reads ASU-RF, the contents of ASU-CQ are checked to find any new entries for that address that may have been written by a predecessor task. When a task wishes to update the contents of ASU-RF, the write is first queued through ASU-CQ. The address used for designating the write location is the same address as would be used in reading. In the present implementation, reads from one location and writes into another location in ASU-RF cannot be done within the same clock cycle. An address select field from SLC (FIG. 11) designates if the results of the address decouple are being used, if the ASU may be used for PC fetch, and also designates the address source for reading and updating ASU-RF.
The ASU Change Queue ASU-CQ may typically comprise a "Lock" and, for example, two slots. Each slot typically contains fields for the task number, the address of the location in ASU-RF, a base value, and a limit value. The Lock indicates the task number that has the Lock set. When the Lock is not set, this value is typically zero.
ASU Change Queue ASU-CQ (FIG. 15)--Typical Read Operation (FIG. 16)
If a task does a read, CONDITIONS within ASU-CQ are checked in the logical order set forth below causing the ACTION listed with each condition to occur. Refer also to the typical read flow for ASU-CQ illustrated in FIG. 16.
______________________________________CONDITION: Predecessor task has Lock.ACTION: Read Task put to sleep waiting on "change to ASU". SLC will generate a Present Cycle Abort (PCA).CONDITION: Predecessor task has invalid address in address field of slot.ACTION: Read task put to sleep waiting on "change to ASU". SLC will generate a Present Cycle Abort (PCA).CONDITION: Predecessor task has the same address as that being read by present task, but data is invalid.ACTION: Read task put to sleep waiting on "change to ASU". SLC will generate a Present Cycle Abort (PCA).CONDITION: Predecessor task has same address and valid data.ACTION: Contents read from ASU Change Queue.CONDITION: All predecessor tasks have different addresses.ACTION: Contents read from ASU Register File.______________________________________
Note with respect to FIG. 16 and the above listing that, when both slots contain valid data for the requested address, then the latest copy is given the read task. Also note that, when a task becomes active after having been put to sleep, then the FIG. 16 flow is again checked.
ASU Change Queue ASU-CQ (FIG. 15)--Typical Unload Operation
Once a Task has reached Oldest Active Task (OAT) and the contents of the slot are marked valid (address and data), then that slot may be written into ASU-RF. When the slot contents have been successfully written into ASU-RF, the slot is made available--that is, the task number is set to zero and the validity bits for the address and data are reset. The Task Controller TC (FIG. 10) monitors the condition "OAT not in ASU-CQ". This is one of the conditions used by TC for termination of the task.
ASU Change Queue ASU-CQ (FIG. 15)--Typical Write Operation
If a task is to write new values into ASU-RF then, at the initiation of that task by PC (FIG. 9), the ASU Lock is set with that task number. A task must have the Lock in order to acquire an ASU Change Queue slot. If the Lock is already set by a preceding task, then PC is stopped until the Lock is unlocked. The Lock can then be set for this next task and PC started. When a task requests a slot, ASU will verify that a slot is available. If a slot is not available, that task is put to sleep waiting on a "change to ASU". When the slot is acquired, the task number is written into the slot. The address and data components may be supplied independently or together, at any time. The value component is obtained from ASU-ALU and LC. Writing into the ASU Change Queue is performed during the Write operation of each clock cycle (Stage 3). If a Present Cycle Abort (PCA) condition occurs, the writing is inhibited. A "Change to ASU" is caused by unloading of a slot, making the address and data in ASU-CQ valid, and unlocking of the ASU-CQ.
ASU Arithmetic Logic Unit ASU-ALU (FIG. 15)
ASU-ALU performs simple arithmetic and logical operations on two operands applied thereto. These two operands, designated the "base" and the "index", are usually, but not always, memory addresses. The base input can come from ASU-RF or from ASU-CQ, and also from DRF of DP (FIG. 14). The index input can come from AD, DRF of DP, or from PC (FIG. 9). The output of ASU-ALU is provided to the Limit Checker LC, to the Memory System MS (FIG. 2) (as a memory address), and to DP (to be written into SPR or DRF). The output of ASU-ALU can also be written into the base portion of a word in ASU-RF via ASU-CQ.
Limit Checker LC (FIG. 15)
The Limit Checker LC performs address comparison, provides branch conditions to SLC (FIG. 11) based on this comparison, and can optionally cancel a memory request based on the comparison. One of the two inputs to the Limit Checker LC is from ASU-ALU. The other input comes from the limit portion of the word which supplied the base input to ASU-ALU.
Memory System MS (FIGS. 2 and 17)
With reference to FIG. 17, the Memory System MS (illustrated in block form in FIG. 2) may typically comprise the following: a plurality of Memory Modules MM; a Memory Exchange MEX serving as an expansion module to interface to MM and GM; and a Memory Control MC (including a Cache Memory CHM and a Memory Change Queue MCQ) serving as an interface to MM and the Global Memory GM (FIG. 1) from the Processing Element PE (FIG. 3).
The Cache Memory CHM is typically a very high-speed memory which contains redundant copies of recently accessed blocks of words in MM. Memory read requests are satisfied by reading words from CHM if the appropriate block is present therein, thus avoiding the greater time required for an MM access. However, if the appropriate block is not present in CHM, it is fetched from MM and replaces some other block in CHM. Memory write operations are always written to MM and are also written to CHM if the appropriate block is present. Thus, CHM data is always identical to MM data, and no updating of MM is necessary when a CHM block is replaced.
The Memory Change Queue MCQ is used to queue changes to MM in a basically similar manner to that described previously for ASU-CQ (FIG. 15). The Memory Change Queue MCQ is used for accessing operations with respect to both MM and the Global Memory GM.
A task (other than the HDP task) makes a request for a memory write operation by entering a complete entry into the Memory Change Queue MCQ. As described previously with regard to the ASU-CQ, a requesting task is required to own the change queue lock in order to gain entry to MCQ, this lock being acquired for the requesting task by the Program Controller PC (FIG. 9) before task initiation. The information for entry to MCQ may be supplied at the same time that the entry is placed in MCQ, or may be supplied at a later time. After entry has been completed, MS will initiate operation for a requesting task when the task has reached the top of MCQ and has become the Oldest Active Task (OAT).
A task makes a read memory request by supplying the memory address obtained from the output of the ASU Arithmetic and Logic Unit ASU-ALU (FIG. 15) along with the converted address obtained from the Register Mapper RMAP of DP (FIG. 14). The task may then continue processing if it has something else to do while the addressed data is being accessed from memory. If not, the task is put into a Waiting state. Each requesting task also involves a Memory Action Complete (MAC) condition. This condition is cleared at the beginning of every memory request by that task and is set by the memory subsystem when the request has been satisfied. This signals the Task Controller TC (FIG. 10) to return the task to Ready status if it has been in a Waiting State because of this condition.
Although the description of the invention provided herein has been primarily directed to particular illustrative embodiments in order to clearly demonstrate the basic principles of the invention and the manner in which it may be readily practiced so as to take advantage of the stated features and advantages, it is to be understood that many modifications and variations in structure, arrangement, components, operation and use are possible within the contemplated scope of the invention without departing from the spirit of the invention. The appended claims are accordingly intended to cover and embrace all such possible modifications and variations within the true spirit and scope of the invention. | A pipelined microprogrammed data processing system is provided having a three-stage pipelined architecture implemented so as to in effect provide for the execution of a plurality of microinstructions using three separate processors operating 120 degrees out of phase with one another and sharing the same physical hardware. Synchronized microinstruction tasking and dynamic resource allocation are also provided in the system to provide both multiprogramming and multiprocessing on a microinstruction level. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 11/371,309 filed 9 Mar. 2006, which is a Reissue of U.S. patent application Ser. No. 09/647,057 filed 20 Dec. 2000 (U.S. Pat. No. 6,708,145), which is a National Phase entry of PCT Patent Application Serial No. PCT/SE00/00159 filed 26 Jan. 2000.
TECHNICAL FIELD
[0002] The present invention relates to source coding systems utilising high frequency reconstruction (HFR) such as Spectral Band Replication, SBR [WO 98/57436] or related methods. It improves performance of both high quality methods (SBR), as well as low quality copy-up methods [U.S. Pat. No. 5,127,054]. It is applicable to both speech coding and natural audio coding systems. Furthermore, the invention can beneficially be used with natural audio codecs with- or without high-frequency reconstruction, to reduce the audible effect of frequency bands shut-down usually occurring under low bitrate conditions, by applying Adaptive Noise-floor Addition.
BACKGROUND OF THE INVENTION
[0003] The presence of stochastic signal components is an important property of many musical instruments, as well as the human voice. Reproduction of these noise components, which usually are mixed with other signal components, is crucial if the signal is to be perceived as natural sounding. In high-frequency reconstruction it is, under certain conditions, imperative to add noise to the reconstructed high-band in order to achieve noise contents similar to the original. This necessity originates from the fact that most harmonic sounds, from for instance reed or bow instruments, have a higher relative noise level in the high frequency region compared to the low frequency region. Furthermore, harmonic sounds sometimes occur together with a high frequency noise resulting in a signal with no similarity between noise levels of the highband and the low band. In either case, a frequency transposition, i.e. high quality SBR, as well as any low quality copy-up-process will occasionally suffer from lack of noise in the replicated highband. Even further, a high frequency reconstruction process usually comprises some sort of envelope adjustment, where it is desirable to avoid unwanted noise substitution for harmonics. It is thus essential to be able to add and control noise levels in the high frequency regeneration process at the decoder.
[0004] Under low bitrate conditions natural audio codecs commonly display severe shut down of frequency bands. This is performed on a frame to frame basis resulting in spectral holes that can appear in an arbitrary fashion over the entire coded frequency range. This can cause audible artifacts. The effect of this can be alleviated by Adaptive Noise-floor Addition.
[0005] Some prior art audio coding systems include means to recreate noise components at the decoder. This permits the encoder to omit noise components in the coding process, thus making it more efficient. However, for such methods to be successful, the noise excluded in the encoding process by the encoder must not contain other signal components. This hard decision based noise coding scheme results in a relatively low duty cycle since most noise components are usually mixed, in time and/or frequency, with other signal components. Furthermore it does not by any means solve the problem of insufficient noise contents in reconstructed high frequency bands.
SUMMARY OF THE INVENTION
[0006] The present invention addresses the problem of insufficient noise contents in a regenerated highband, and spectral holes due to frequency bands shut-down under low-bitrate conditions, by adaptively adding a noise-floor. It also prevents unwanted noise substitution for harmonics. This is performed by means of a noise-floor level estimation in the encoder, and adaptive noise-floor addition and unwanted noise substitution limiting at the decoder.
[0007] The Adaptive Noise-floor Addition and the Noise Substitution Limiting method comprise the following steps:
At an encoder, estimating the noise-floor level of an original signal, using dip- and peak-followers applied to a spectral representation of the original signal; At an encoder mapping the noise-floor level to several frequency bands, or representing it using LPC or any other polynomial representation; At an encoder or decoder, smoothing the noise-floor level in time and/or frequency; At a decoder, shaping random noise in accordance to a spectral envelope representation of the original signal, and adjusting the noise in accordance to the noise-floor level estimated in the encoder; At a decoder, smoothing the noise level in time and/or frequency; Adding the noise-floor to the high-frequency reconstructed signal, either in the regenerated high-band, or in the shut-down frequency bands. At a decoder, adjusting the spectral envelope of the high-frequency reconstructed signal using limiting of the envelope adjustment amplification factors. At a decoder, using interpolation of the received spectral envelope, for increased frequency resolution, and thus improved performance of the limiter. At a decoder, applying smoothing to the envelope adjustment amplification factors. At a decoder generating a high-frequency reconstructed signal which is the sum of several high-frequency reconstructed signals, originating from different lowband frequency ranges, and analysing the lowband to provide control data to the summation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will now be described by way of illustrative examples, not limiting the scope or spirit of the invention, with reference to the accompanying drawings, in which:
[0019] FIG. 1 illustrates the peak- and dip-follower applied to a high- and medium-resolution spectrum, and the mapping of the noise-floor to frequency bands, according to the present invention;
[0020] FIG. 2 illustrates the noise-floor with smoothing in time and frequency, according to the present invention;
[0021] FIG. 3 illustrates the spectrum of an original input signal;
[0022] FIG. 4 illustrates the spectrum of the output signal from a SBR process without Adaptive Noise-floor Addition;
[0023] FIG. 5 illustrates the spectrum of the output signal with SBR and Adaptive Noise-floor Addition, according to the present invention;
[0024] FIG. 6 illustrates the amplification factors for the spectral envelope adjustment filterbank, according to the present invention;
[0025] FIG. 7 illustrates the smoothing of amplification factors in the spectral envelope adjustment filterbank, according to the present invention;
[0026] FIG. 8 illustrates a possible implementation of the present invention, in a source coding system on the encoder side;
[0027] FIG. 9 illustrates a possible implementation of the present invention, in a source coding system on the decoder side.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] The below-described embodiments are merely illustrative for the principles of the present invention for improvement of high frequency reconstruction systems. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the impending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein.
Noise-Floor Level Estimation
[0029] When analysing an audio signal spectrum with sufficient frequency resolution, formants, single sinusodials etc. are clearly visible, this is hereinafter referred to as the fine structured spectral envelope. However, if a low resolution is used, no fine details can be observed, this is hereinafter referred to as the coarse structured spectral envelope. The level of the noise-floor, albeit it is not necessarily noise by definition, as used throughout the present invention, refers to the ratio between a coarse structured spectral envelope interpolated along the local minimum points in the high resolution spectrum, and a coarse structured spectral envelope interpolated along the local maximum points in the high resolution spectrum. This measurement is obtained by computing a high resolution FFT for the signal segment, and applying a peak- and dip-follower, FIG. 1 . The noise-floor level is then computed as the difference between the peak- and the dip-follower. With appropriate smoothing of this signal in time and frequency, a noise-floor level measure is obtained. The peak follower function and the dip follower function can be described according to eq. 1 and eq. 2,
[0000]
Y
peak
(
X
(
k
)
)
=
max
(
Y
(
X
(
k
-
1
)
)
-
T
,
X
(
k
)
)
∀
1
≤
k
≤
fftSize
2
eq
.
1
Y
dip
(
X
(
k
)
)
=
min
(
Y
(
X
(
k
-
1
)
)
+
T
,
X
(
k
)
)
∀
1
≤
k
≤
fftSize
2
eq
.
2
[0000] where T is the decay factor, and X(k) is the logarithmic absolute value of the spectrum at line k. The pair is calculated for two different FFT sizes, one high resolution and one medium resolution, in order to get a good estimate during vibratos and quasi-stationary sounds. The peak- and dip-followers applied to the high resolution FFT are LP-filtered in order to discard extreme values. After obtaining the two noise-floor level estimates, the largest is chosen. In one implementation of the present invention the noise-floor level values are mapped to multiple frequency bands, however, other mappings could also be used e.g. curve fitting polynomials or LPC coefficients. It should be pointed out that several different approaches could be used when determining the noise contents in an audio signal. However it is, as described above, one objective of this invention, to estimate the difference between local minima and maxima in a high-resolution spectrum, albeit this is not necessarily an accurate measurement of the true noise-level. Other possible methods are linear prediction, autocorrelation etc, these are commonly used in hard decision noise/no noise algorithms [“Improving Audio Codecs by Noise Substitution” D. Schultz, JAES, Vol. 44, No. 7/8, 1996]. Although these methods strive to measure the amount of true noise in a signal, they are applicable for measuring a noise-floor-level as defined in the present invention, albeit not giving equally good results as the method outlined above. It is also possible to use an analysis by synthesis approach, i.e. having a decoder in the encoder and in this manner assessing a correct value of the amount of adaptive noise required.
Adaptive Noise-Floor Addition
[0030] In order to apply the adaptive noise-floor, a spectral envelope representation of the signal must be available. This can be linear PCM values for filterbank implementations or an LPC representation. The noise-floor is shaped according to this envelope prior to adjusting it to correct levels, according to the values received by the decoder. It is also possible to adjust the levels with an additional offset given in the decoder.
[0031] In one decoder implementation of the present invention, the received noise-floor levels are compared to an upper limit given in the decoder, mapped to several filterbank channels and subsequently smoothed by LP filtering in both time and frequency, FIG. 2 . The replicated highband signal is adjusted in order to obtain the correct total signal level after adding the noise-floor to the signal. The adjustment factors and noise-floor energies are calculated according to eq. 3 and eq. 4.
[0000]
noiseLevel
(
k
,
l
)
=
sfb_nrg
(
k
,
l
)
·
nf
(
k
,
l
)
1
+
nf
(
k
,
l
)
eq
.
3
adjustFactor
(
k
,
l
)
=
1
1
+
nf
(
k
,
l
)
eq
.
4
[0000] where k indicates the frequency line, l the time index for each sub-band sample, sfb_nrg(k,l) is the envelope representation, and nf(k,l) is the noise-floor level. When noise is generated with energy noiseLevel(k,l) and the highband amplitude is adjusted with adjustFactor(k,l) the added noise-floor and highband will have energy in accordance with sfb_nrg(k,l). An example of the output from the algorithm is displayed in FIG. 3-5 . FIG. 3 shows the spectrum of an original signal containing a very pronounced formant structure in the low band, but much less pronounced in the highband. Processing this with SBR without Adaptive Noise-floor Addition yields a result according to FIG. 4 . Here it is evident that although the formant structure of the replicated highband is correct, the noise-floor level is too low. The noise-floor level estimated and applied according to the invention yields the result of FIG. 5 , where the noise-floor superimposed on the replicated highband is displayed. The benefit of Adaptive Noise-floor Addition is here very obvious both visually and audibly.
Transposer Gain Adaptation
[0032] An ideal replication process, utilising multiple transposition factors, produces a large number of harmonic components, providing a harmonic density similar to that of the original. A method to select appropriate amplification-factors for the different harmonics is described below. Assume that the input signal is a harmonic series:
[0000]
x
(
t
)
=
∑
i
=
0
N
-
1
a
i
cos
(
2
π
f
i
t
)
.
eq
.
5
[0033] A transposition by a factor two yields:
[0000]
y
(
t
)
=
∑
i
=
0
N
-
1
a
i
cos
(
2
×
2
π
f
i
t
)
.
eq
.
6
[0034] Clearly, every second harmonic in the transposed signal is missing. In order to increase the harmonic density, harmonics from higher order transpositions, M=3, 5 etc, are added to the highband. To benefit the most of multiple harmonics, it is important to appropriately adjust their levels to avoid one harmonic dominating over another within an overlapping frequency range. A problem that arises when doing so, is how to handle the differences in signal level between the source ranges of the harmonics. These differences also tend to vary between programme material, which makes it difficult to use constant gain factors for the different harmonics. A method for level adjustment of the harmonics that takes the spectral distribution in the low band into account is here explained. The outputs from the transposers are fed through gain adjusters, added and sent to the envelope-adjustment filterbank. Also sent to this filterbank is the low band signal enabling spectral analysis of the same. In the present invention the signal-powers of the source ranges corresponding to the different transposition factors are assessed and the gains of the harmonics are adjusted accordingly. A more elaborate solution is to estimate the slope of the low band spectrum and compensate for this prior to the filterbank, using simple filter implementations, e.g. shelving filters. It is important to note that this procedure does not affect the equalisation functionality of the filterbank, and that the low band analysed by the filterbank is not re-synthesised by the same.
Noise Substitution Limiting
[0035] According to the above (eq. 5 and eq. 6), the replicated highband will occasionally contain holes in the spectrum. The envelope adjustment algorithm strives to make the spectral envelope of the regenerated highband similar to that of the original. Suppose the original signal has a high energy within a frequency band, and that the transposed signal displays a spectral hole within this frequency band. This implies, provided the amplification factors are allowed to assume arbitrary values, that a very high amplification factor will be applied to this frequency band, and noise or other unwanted signal components will be adjusted to the same energy as that of the original. This is referred to as unwanted noise substitution. Let
[0000] P 1 =[p 11 , . . . , p 1N ] eq. 7
[0000] be the scale factors of the original signal at a given time, and
[0000] P 2 =[p 21 , . . . , p 2N ] eq. 8
[0000] the corresponding scale factors of the transposed signal, where every element of the two vectors represents sub-band energy normalised in time and frequency. The required amplification factors for the spectral envelope adjustment filterbank is obtained as
[0000]
G
=
[
g
1
,
…
,
g
N
]
=
[
p
11
p
21
,
…
,
p
1
N
p
2
N
]
.
eq
.
9
[0036] By observing G it is trivial to determine the frequency bands with unwanted noise substitution, since these exhibit much higher amplification factors than the others. The unwanted noise substitution is thus easily avoided by applying a limiter to the amplification factors, i.e. allowing them to vary freely up to a certain limit, g max . The amplification factors using the noise-limiter is obtained by
[0000] G lim =[min( g 1 ,g max ), . . . , min( g N ,g max )]. eq. 10
[0000] However, this expression only displays the basic principle of the noise-limiters. Since the spectral envelope of the transposed and the original signal might differ significantly in both level and slope, it is not feasible to use constant values for g max . Instead, the average gain, defined as
[0000]
G
avg
=
∑
i
P
1
i
∑
i
P
2
i
,
eq
.
11
[0000] is calculated and the amplification factors are allowed to exceed that by a certain amount. In order to take wide-band level variations into account, it is also possible to divide the two vectors P 1 and P 2 into different sub-vectors, and process them accordingly. In this manner, a very efficient noise limiter is obtained, without interfering with, or confining, the functionality of the level-adjustment of the sub-band signals containing useful information.
Interpolation
[0037] It is common in sub-band audio coders to group the channels of the analysis filterbank, when generating scale factors. The scale factors represent an estimate of the spectral density within the frequency band containing the grouped analysis filterbank channels. In order to obtain the lowest possible bit rate it is desirable to minimise the number of scale factors transmitted, which implies the usage of as large groups of filter channels as possible. Usually this is done by grouping the frequency bands according to a Bark-scale, thus exploiting the logarithmic frequency resolution of the human auditory system. It is possible in an SBR-decoder envelope adjustment filterbank, to group the channels identically to the grouping used during the scale factor calculation in the encoder. However, the adjustment filterbank can still operate on a filterbank channel basis, by interpolating values from the received scale factors. The simplest interpolation method is to assign every filterbank channel within the group used for the scale factor calculation, the value of the scale factor. The transposed signal is also analysed and a scale factor per filterbank channel is calculated. These scale factors and the interpolated ones, representing the original spectral envelope, are used to calculate the amplification factors according to the above. There are two major advantages with this frequency domain interpolation scheme. The transposed signal usually has a sparser spectrum than the original. A spectral smoothing is thus beneficial and such is made more efficient when it operates on narrow frequency bands, compared to wide bands. In other words, the generated harmonics can be better isolated and controlled by the envelope adjustment filterbank. Furthermore, the performance of the noise limiter is improved since spectral holes can be better estimated and controlled with higher frequency resolution.
Smoothing
[0038] It is advantageous, after obtaining the appropriate amplification factors, to apply smoothing in time and frequency, in order to avoid aliasing and ringing in the adjusting filterbank as well as ripple in the amplification factors. FIG. 6 displays the amplification factors to be multiplied with the corresponding subband samples. The figure displays two high-resolution blocks followed by three low-resolution blocks and one high resolution block. It also shows the decreasing frequency resolution at higher frequencies. The sharpness of FIG. 6 is eliminated in FIG. 7 by filtering of the amplification factors in both time and frequency, for example by employing a weighted moving average. It is important however, to maintain the transient structure for the short blocks in time in order not to reduce the transient response of the replicated frequency range. Similarly, it is important not to filter the amplification factors for the high-resolution blocks excessively in order to maintain the formant structure of the replicated frequency range. In FIG. 9 b the filtering is intentionally exaggerated for better visibility.
Practical Implementations
[0039] The present invention can be implemented in both hardware chips and DSPs, for various kinds of systems, for storage or transmission of signals, analogue or digital, using arbitrary codecs. FIG. 8 and FIG. 9 shows a possible implementation of the present invention. Here the high-band reconstruction is done by means of Spectral Band Replication, SBR. In FIG. 8 the encoder side is displayed. The analogue input signal is fed to the A/D converter 801 , and to an arbitrary audio coder, 802 , as well as the noise-floor level estimation unit 803 , and an envelope extraction unit 804 . The coded information is multiplexed into a serial bitstream, 805 , and transmitted or stored. In FIG. 9 a typical decoder implementation is displayed. The serial bitstream is de-multiplexed, 901 , and the envelope data is decoded, 902 , i.e. the spectral envelope of the high-band and the noise-floor level. The de-multiplexed source coded signal is decoded using an arbitrary audio decoder, 903 , and up-sampled 904 . In the present implementation SBR-transposition is applied in unit 905 . In this unit the different harmonics are amplified using the feedback information from the analysis filterbank, 908 , according to the present invention. The noise-floor level data is sent to the Adaptive Noise-floor Addition unit, 906 , where a noise-floor is generated. The spectral envelope data is interpolated, 907 , the amplification factors are limited 909 , and smoothed 910 , according to the present invention. The reconstructed high-band is adjusted 911 and the adaptive noise is added. Finally, the signal is re-synthesised 912 and added to the delayed 913 low-band. The digital output is converted back to an analogue waveform 914 . | Methods and an apparatus for enhancement of source coding systems utilizing high frequency reconstruction (HFR) are introduced. The problem of insufficient noise contents is addressed in a reconstructed highband, by using Adaptive Noise-floor Addition. New methods are also introduced for enhanced performance by means of limiting unwanted noise, interpolation and smoothing of envelope adjustment amplification factors. The methods and apparatus used are applicable to both speech coding and natural audio coding systems. | 6 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The field of the invention relates, in general, to an exercise sleeve containing weights to provide weight resistance for a user to increase the benefits of exercise. More particularly, the exercise sleeve is adjustable and can be interchangeably worn on either the hand and wrist area or the foot and ankle area.
2. Discussion of Prior Art
In today's health conscious society, the benefits of regular, moderate exercise are almost universally recognized. One of the most popular and effective forms of exercise is training utilizing weight resistance. This type of training can be pure weight training such as using barbells and other very heavy weights to provide weight resistance. Another form of weight training combines aspects of aerobic exercise with moderate weight resistance. It is this second form of aerobic exercise combined with moderate weight resistance for which the present invention is particularly suited.
Various types of aerobic training combined with moderate weight resistance are exercise regimens as follows: walking or jogging combined with ankle or wrist weights; step aerobics with ankle or wrist weights; swimming with hand weights; bicycling with ankle weights. Almost any form of aerobic exercise can be combined with ankle or wrist weights to increase the benefits of the exercise.
In view of the fact that aerobic training with moderate weight resistance is such a popular and beneficial exercise regimen, there exists a need for an adjustable exercise sleeve that can be worn on either the hand and wrist or foot and ankle area of the user. The present invention provides for a weighted adjustable exercise sleeve that can easily be worn on the hand and wrist area or quickly converted for use on the foot and ankle area of the user.
The prior art has heretofore afforded various apparatuses to provide moderate weight resistance for the foot or hand. However, these apparatus are specifically designed for either the foot or hand area. The present invention is distinct because it is specifically designed to be adjustable so that it can be interchangeably worn on either the hand and wrist area or the foot and ankle area.
Prior art examples of weight resistance apparatuses are discussed below.
The patents to Tarbox et al. (U.S. Pat. Nos. 4,556,215 and 4,575,075) provide for a weighted hand exercise sleeve including an opening through which the thumb is inserted when the sleeve is secured to the hand.
The patents to Schwartz (U.S. Pat. Nos. 4,247,097 and 5,300,000) provide for exercise sleeves for the hand and wrist that have removable weights in pockets on the outside of the sleeve.
The patent to Holmes (U.S. Pat. No. 5,169,371) provides for a weighted glove fastened to the hand by hook and loop material or straps with buckles.
The patent to Hoffman (U.S. Pat. 5,004,227) provides for an exercise apparatus for strapping weights to a user's hand for swimming or jogging.
The patent to White (U.S. Pat. No. 4,322,072) provides for an exercise apparatus for attachment to a foot that includes pockets for receiving weights.
The patent to Mason (U.S. Pat. No. 3,406,968) provides for an isometric exercise boot with weighted pockets.
The prior art does provide for various weighted exercise sleeve apparatuses for either the hand and wrist area or the foot and ankle area. However, none of the prior art apparatuses provides for an exercise sleeve that can be adjusted and interchangeably worn on either the hand and wrist area or the foot and ankle area as per the present invention.
It is common in the prior art to include various means to secure weighted exercise sleeves to the user including straps, hook and loop fasteners and other similar securing means. However, these securing means are designed with specific configurations which provide attachment to the hand and wrist area or the foot and ankle area but not both. The present invention is distinguishable from the prior art because the exercise sleeve can be interchangeably worn on either the hand and wrist area or the foot and ankle area and the securing means of the present invention is adjustable so that the exercise sleeve will have a proper, comfortable fit in either arrangement.
The prior art provides for various types of weights that can be used for exercise sleeve apparatuses including lead shot, metals or other materials. The present invention utilizes these and other types of weights.
The prior art does provide for reclosable weight pockets for exercise sleeves wherein the closure means are hook and loop fasteners, zippers, straps and other devices. The present invention utilizes these and other closure means to reclose the weight pockets.
SUMMARY OF THE INVENTION
As shown by the prior art, there exists a need for an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area.
It is therefore an object of the invention to provide an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area.
It is another object of the invention to provide for an adjustable securing means that can be arranged to secure a proper, comfortable fit for the weighted exercise sleeve on either the hand and wrist area or the foot and ankle area.
It is another object of the invention to provide for an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area wherein the amount of weight in the exercise sleeve can be varied by increasing or decreasing the number of weighted pockets of material.
It is another object of this invention to provide for an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area wherein the pockets containing the weight materials are reclosable so that weights can be inserted or removed as desired by the user.
The instant invention solves the aforementioned problem by providing an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area.
These and other objects of the invention will become evident when taken in conjunction with the drawings, claims and description of the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an external view of the preferred embodiment in an unattached and open position.
FIG. 2 illustrates an inside view of the configuration of FIG. 1.
FIG. 3a illustrates the invention, as shown in FIGS. 1 and 2, secured to the hand and wrist area of a user.
FIG. 3b illustrates the invention secured to the hand and wrist area of a user with the weights shifted towards the wrist area.
FIG. 3c illustrates the invention with weights located both on the hand and wrist sections.
FIG. 3d illustrates the invention with a longer wrist section with additional weighting sections.
FIG. 4a illustrates a front view of the invention as it would be configured to be secured to the foot and ankle area of a user.
FIG. 4b illustrates a side view of the invention secured to the foot and ankle area of a user.
FIG. 4c illustrates a side view of alternative embodiment of the invention as it would appear secured to foot and ankle area of a user with adjustable weight enclosures.
FIG. 4d illustrates an alternative embodiment of the invention secured to the foot and ankle area of a user with an extended ankle/shin section and additional weight sections thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the preferred embodiment of the present invention comprising an exercise sleeve 1 in an open position and lying flat. The exercise sleeve 1 is constructed of a durable flexible, water resistant material that can be readily secured to the hand and wrist area or foot and ankle area of a user. The exercise sleeve 1 can be made of any durable, flexible, expansible, water resistant material such as neoprene, rubber, nylon, LYCRA®, SPANDEX®, terry cloth, elastic, cotton, plastic or combinations of the above materials. The invention should not be limited to the above listed materials but may be interchanged with comparable materials.
The exercise sleeve 1 has weight pockets 2 and 3 on the outside of sleeve 1 that contain weight materials. The weight materials can be lead shot, lead beads, lead pellets, clay, water, gel substances, metal pellets, metal shavings, metal bars, metal ingots, plastic or combinations of the above materials or equivalents thereof.
Fixed weight pocket 2 is factory sealed and contains a predetermined amount of weight material. Weight pocket 3 is shown in an alternative embodiment with a weight varying opening. Weight pocket 3 is reclosable by reclosing member 4. Reclosing member 4 can be hook and loop fastener (VELCRO®), zippers (as shown), clamps (metal, plastic or other), clips (metal, plastic or other), tied fabric or combinations of the above reclosing members. Variable weight pocket 3 has a reclosing member 4 so that the user of the exercise sleeve 1 can increase or decrease weight resistance by adding to or subtracting weight materials from the variable weight pocket 3. Thus, the user of the sleeve 1 can customize the weight resistance to suit his particular needs.
FIG. 2 illustrates the reverse side of the preferred embodiment as shown in FIG. 1. Exercise sleeve 1 is secured to the user by wrapping sleeve 1 around the area for which weight resistance is desired. Sleeve 1 has a securing means 8 comprising a hook and loop fastener (VELCRO®) patch on the outside of the sleeve. Sleeve 1 has securing means 9, 10 on the inside of sleeve 1. Securing means 9, 10 comprise patches of hook and loop fastener (VELCRO®) on the inside of sleeve 1.
FIGS. 3a and 3b illustrate the exercise sleeve attached to a user's hand. Sleeve 1 has an opening 5 through which the user's fingers are placed. Opening 5 is surrounded by the main body of sleeve 1 and the stirrup stabilizer band 6. The stirrup stabilizer band 6 is the part of sleeve 1 that positions sleeve 1 in a proper manner on the user's body. After sleeve 1 is wrapped around a user's hand and wrist area, securing means 9 on the inside of sleeve 1 is attached to securing means 8 on the outside of the sleeve 1. Opening 25 is formed upon connecting securing means 8 to securing means 9 for the purpose of retaining the user's thumb. By proper alignment the apparatus will fit securely around the wrist area. The stirrup stabilizer band 6 has a tension adjustment strap assembly 7a, with buckle and strap 7b which can be fed through the buckle and folded back against an opposing VELCRO® receiving section so that band 6 can be tightened or loosened to secure a proper fit through the thumb webbing area.
As discussed above, when the invention is used with the hand and wrist area, securing means 9 is attached to securing means 8. Used in this manner, the sleeve 1 would have an extra portion of the sleeve 1 where securing means 10 is located hanging unattached to any other part of sleeve 1. In order to secure this portion of sleeve 1, a hook and loop fastener (VELCRO®) patch 11 is placed on the outside of sleeve 1 opposite securing means 10. Hook and loop fastener (VELCRO®) patch 11 is then folded back to come into contact with hook and loop fastener (VELCRO®) patch 12 to secure this portion of sleeve 1.
FIG. 3b shows the invention with a slightly lengthened wrist section and has the weights 2 and 3 shifted to the wrist area.
FIG. 3c illustrates a combination of embodiments 3a and 3b with weights 2 and 14 located on both the hand and wrist with extended wrist section 13.
FIG. 3d illustrates an extended wrist section 15 with many weights 16 but with no hand section weights as shown originally by elements 2 and 3 of FIGS. 1 and 2, etc. The wrist section may contain weight varying openings as per original element 4.
FIGS. 4a-4d illustrate various embodiments of the invention when attached to the foot and ankle area. In the preferred embodiment, the configuration as shown in FIGS. 1, 2 and 3a is now secured as shown in FIGS. 4a or 4b.
The user places the toes of his foot through opening 5 so that band 6 is around the heel/arch area. Tension adjustment strap assembly 7a and 7b can be attached to band 6 (FIG. 4a) or may be reversed and folded back without threading through the buckle of 7a as shown in FIG. 4b. Strap 7 is adjustable in order to tighten or loosen band 6 to properly fit the user.
When sleeve 1 is wrapped around user's foot and ankle area, hook and loop fastener (VELCRO®) securing means 10 on the inside of sleeve 1 is attached to hook and loop fastener (VELCRO®) receiving means 8 on the inside of the sleeve 1. Hook and loop fastener (VELCRO®) securing means 9 is located closer to the center of sleeve 1 than securing means 10 and can be used for a user with a small diameter ankle area. As in the above discussion with respect to extra material, the hook and loop fastener (VELCRO®) patch 11 is then folded back to come into contact with hook and loop fastener (VELCRO®) patch 12 to secure this portion of sleeve 1.
FIG. 4c illustrates a side view of an alternative embodiment of the invention as it would appear secured to foot and ankle area of a user with adjustable weight enclosures.
FIG. 4d illustrates an alternative embodiment of the invention secured to the foot and ankle area of a user with an extended ankle/shin section and additional weight sections thereon.
CONCLUSION
A system and method has been shown in the above embodiments for the effective implementation of an adjustable weighted exercise sleeve that can be interchangeably worn on either the hand and wrist area or the foot and ankle area of a user. While various preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims. The invention should not be limited by size, shape and/or materials. In addition, the weight materials, securing means and reclosable members may be of any known type in the art that accomplishes the desired purpose. Sleeve 1 can be varied in size to accommodate numerous weight pockets and any combination of fixed weight pockets 2 and variable weight pockets 3. | An adjustable weighted exercise sleeve that fits over the hand or foot and is secured thereto enabling the user to accomplish various exercises with the benefit of weight resistance. The adjustable weighted exercise sleeve has adjustable straps secured by hook and loop fasteners to provide a comfortable fit for the user. The configuration of the exercise sleeve and adjustable straps allows the user to interchangeably wear the exercise sleeve on the hand and wrist or foot and ankle. The exercise sleeve uses variable weighting arrangements to allow the user to choose a weight resistance for optimum comfort and physiological benefit. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to paper web formation analyzers. Such structures of this type, generally, can be employed both on paper machines operating at high speed and on cut samples as a desk top unit, so as to unify formation evaluation for both situations.
2. Description of the Related Art
It is well known, in the paper making industry, to make use of various sheet material characteristic measuring devices. Exemplary of such prior art is U.S. Pat. No. 3,936,665 ('665) to J. F. Donoghue, entitled "Sheet Material Characteristics Measuring, Monitoring and Controlling Method and Apparatus Using Data Profile Generated and Evaluated by Computer Means". While the '665 patent teaches the control of primary paper properties such as basis weight, moisture and caliper, the focus of the '665 patent is more for control of primary properties than in evaluating sheet formation. Consequently, a more advantageous analyzer, then would be presented if sheet formation could also be evaluated.
It is also known, to employ a single point measuring technique to measure sheet formation as well as other primary paper properties, such as, paper strength. Exemplary of such prior art is U.S. Pat. No. 5,104,488 ('488) to L. M. Chase, entitled "System and Process for Continuous Determination and Control of Paper Strength", U.S. Pat. No. 4,707,223 ('223) to J. Sabater et al., entitled "Apparatus for Measuring the State of Formation of a Sheet of Paper", U.S. Pat. No. 4,648,712 ('712) to I. F. Brenholdt, entitled "Apparatus and Method for Analyzing Parameters of a Fibrous Substrate", and U.S. Pat. No. 4,644,174 ('174) to R. J. Ouellette et al., entitled "Apparatus for Analyzing the Formation of a Paper Web". While the '488, '223, '712, and '174 patents teach the use of an apparatus to measure sheet formation, these employ a single point sensor to infer overall sheet formation. This single point sensor, typically, is either fixed or scanning, but at any point in time, only a single area is being studied. Consequently, a still further advantageous analyzer, then would be presented if a wider inspection area can be studied, while giving a quantitative picture of what is going on with respect to a paper formation.
It is apparent from the above that there exists a need in the art for a paper web formation analyzer which can provide a wide inspection area while giving a better quantitative picture of paper formation, but which at the same time is capable of being used both on operating paper machines and on cut samples. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
Generally speaking, this invention fulfills these needs by providing an online/offline paper web formation analyzer, comprising a paper web having first and second sides, a paper web translating means, a plurality of paper web illumination means substantially located adjacent to the first side of the paper web, a plurality of paper web formation detection means located substantially adjacent to the second side of the paper web and across from the illumination mean, and a paper web translating rate measurement and illumination/detection synchronization means operatively connected to the paper web translating means, the illumination means and the detection means.
In certain preferred embodiments, the paper web translating means is a pinch roller drive having a nip. Also, the paper web translating rate measurement means is a tachometer. The illumination means are preferably fiber optic, reflected-light sources. Finally, the web formation detection means may take the form of an array of linescan cameras arranged across the moving web.
In another further preferred embodiment, the paper web formation analyzer can be used both on paper machines operating at high speed and on cut samples as a desk top unit to unify formation evaluation for both situations.
The preferred analyzer, according to this invention, offers the following advantages: the ability to analyze paper web formation; the ability to be used both online/offline; the ability to unify formation evaluations; good stability; good durability; and excellent economy. In fact, in many of the preferred embodiments, these factors of paper web formation analysis, use for both online/offline, unification of formation evaluations, and excellent economy are optimized to an extent that is considerably higher than heretofore achieved in prior, known paper web formation analyzers.
The above and other features of the present invention, which will become more apparent as the description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying drawings, wherein like characters represent like parts throughout the several views and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a unified online/offline paper web formation analyzer, according to the present invention;
FIG. 2 is an isometric view of the paper web formation analyzer being employed online on a paper machine, according to the present invention; and,
FIG. 3 is an isometric view of the paper web formation analyzer being used offline as a desk top unit, according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Sheet formation is a measure of the relative uniformity of a light transmitted through the sheet. Localized variations of light transmission can be due to fiber flocs and voids. The smaller and more uniform these variations, the better the formation. In the limiting case, the "perfect" sheet would transmit exactly the same amount of light uniformly throughout its total area, thereby giving a milky appearance.
One can envision quantifying localized light variations from an 8.5" by 11" sample on a 0.030" by a 0.030" grid of gray-scale values where 0 is pure black and 255 is pure white, with values in between. The average of the grid points might be 200, for example, but the values at grid points can range from 185 to 215.
Imagine building a histogram with intensity values on the x-axis and number of grid point occurrences on the y-axis. A conventional off-line formation tester as discussed earlier determines a "formation index" based on the histogram peak height divided by the histogram band width.
With reference to FIG. 1, there is illustrated a unified online/offline paper web formation analyzer 2. Analyzer 2 includes, in part, paper web/sheet 4, light array cabinet 6, a plurality of lights 8, light sensor 10 and conventional tachometer 12.
Preferably, cabinet 6, lights 8 and sensor 10 employ a fiber optic light source and linescan camera, such as, that manufactured by Isys of Midlothian, Va., under the Isys Controls Vision System. However, for the present invention, the fiber optic light source and linescan camera will be placed in a transmitted light configuration.
During the operation of the analyzer 2, the linescan camera or sensor 10 records a linear array of 2,048 gray scale values, which would be spread across the cross-direction (CD) of paper sample 4. Input from tachometer 12, which will be discussed later, from a set of given controllers (for the offline device) serves to trigger the camera 10 to record line after line of data. Each line of data is transmitted to a conventional computer (not shown), where a two-dimensional array is formed. After recording (enough) data on the down web (MD) direction, the formation analysis would begin.
To develop this even further, the method for determining paper web formation would be as follows:
1.) Feed a sample 4 into the analyzer 2.
2.) The computer specifies the light source intensity of light cabinet 6 to an "average" value.
3.) Perform a scan analysis of sheet 4 with the specified light source intensity by moving sheet 4 through the linescan area.
4.) Compute the average gray scale value of received light.
5.) Was the gray-scale value within the specified target average (for example, 180-190)?
6.) If no, increase (or decrease) light source intensity and repeat step 2 by backing up sample 4 through analyzer.
7.) If yes, record the gray scale matrix of received intensities.
8.) Perform the computations in the computer and report the result.
With reference to FIG. 2, there is illustrated an on-line version 20 of analyzer 2. In particular, on-line analyzer 20 includes, in part, paper web 4, light cabinet 6, light source 8, camera 10, tachmometer 12, camera cabinet 22, conventional bracket 24, conventional fasteners 26, and pinch rollers 28.
During the operation of analyzer 20, an array of cameras 10 (only one camera being shown for convenience) is arranged across the moving web 4 and intercepts the light reflected off of web 4 in a single thin 0.010" line in the cross-direction (CD). Tachometer 12 mounted on pinch rollers 28 having a nip provides a synchronized pulse to make camera 10 intercept line after line of intensity data to form up a continuous two-dimensional reflected light gray-scale image. In this manner, the machine tachometer 12 drives the camera speed to obtain a two-dimensional gray-scale image over a specified down web (MD) distance.
The formation mathematics are worked out in the computer (not shown) and displayed for that distance. That image will be flushed from computer memory, then the data gathering and computation processes will be repeated, providing a psuedo-continuous measure of sheet formation.
Finally, FIG. 3 illustrates an off-line version 30 of analyzer 2. In particular, off-line analyzer 30 includes, in part, paper sheet 4, light source 8, camera 10, tachometer 12, cabinet 32, and pinch rollers 34 having a nip.
During the operation of off-line analyzer 30, a single sample 4 to be tested would be fed into analyzer 30. Pinch rollers 34 would grab sample 4 at the nip and feed sample 4 through the test position at a constant speed, fixing camera sample speed as discussed earlier. Once the entire image is recorded, the formation mathematics would be determined by a computer and the results would be displayed as discussed earlier.
Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims. | Paper web formation analyzers can be employed both on operating paper machines at high speed and on cut samples as a desk top unit, so as to unify formation evaluation for both situations. | 3 |
FIELD OF THE INVENTION
This invention relates to rotary reciprocating piston pumps, and more particularly to a ceramic rotary reciprocating piston pump of modular form having capability of automatically returning the liquid displacement flow adjustment to an initial calibrated position after priming and/or cleaning.
BACKGROUND OF THE INVENTION
Precision liquid metering and dispensing apparatus in the field utilize various devices to meter liquids precisely in a dispensing process. Mechanisms used to meter liquids in microliter or milliliter quantities include time per pressure liquid displacement systems, positive liquid displacement pumps, peristaltic tubing pumps, and others. The positive displacement pump is known to be the most accurate and robust device for use in small volume dispensing applications.
There are various positive displacement devices which can be used to move and deposit liquids in a dispensing process. They include diaphragm pumps, piston pumps, gear pumps, syringe pumps and various other mechanisms. The ceramic rotary reciprocating piston pump is the mechanism which is the basis of this invention.
A ceramic rotary reciprocating piston pump offers several advantages over other positive displacement liquid dispensers. One of the advantages results from using the rotary motion of the piston with an integral valving feature to perform the valve function. This method of valving a pump is advantageous in that it eliminates peripheral valving mechanisms that can slow the cycling time of the pump or otherwise be a detriment to the pump's performance. Additionally, the use of a thermally and mechanically stable ceramic material in the construction of the piston and cylinder permits an extremely close running fit to be created thus eliminating the need for secondary seals. The resulting system offers excellent repeatability and long-term reliability as a result of its simplicity of design and limited use of moving parts.
Traditional displacement adjustment of a ceramic rotary reciprocating piston pump utilizes an angularly offset drive. This method allows the magnitude of the piston stroke to be changed by adjusting the relative angular relationship of the piston to the driving motor and its output spindle. U.S. Pat. No. 3,168,872 to H. E. Pinkerton issued Feb. 9, 1965 and entitled "POSITIVE DISPLACEMENT PISTON PUMP" is exemplary of a rotary reciprocating piston pump utilizing an angularly offset drive. The pump of this patent employs a ducted piston which reciprocates and rotates synchronously in a bi-ported cylinder. The piston duct is arranged to connect the ports alternately with the pumping chamber. One port communicates with the pumping chamber on the down stroke of the piston, while the other port is arranged to be exposed to the chamber on the piston upstroke. A piston-cylinder assembly is coupled to the output of a drive motor through an interposed collar or yoke. The piston includes at its outer end a laterally projecting arm having a ball bearing which is adapted to ride in a socket in the collar to thereby provide a universal joint between these parts. A cylinder conveniently receives the piston and is mounted on a bracket rotatable about a vertical axis. The cylinder is provided with at least one pair of ports both of which communicate with the cylinder pumping chamber. When the axis of the collar and that of the piston and cylinder are substantially coaxial, the piston does not reciprocate in the cylinder during the rotation of the collar. As such, no pumping action occurs. When the cylinder is angled about its pivot, the piston will reciprocate at an amount proportional to the angular displacement. The direction of rotation, that is either clockwise or counterclockwise determines the direction of fluid feed. The magnitude of the angular displacement of the piston and cylinder determines the amplitude of piston stroke and consequently flow rate. In a variation, the yoke rather than the cylinder is pivotal. In the past, the adjustment of the angular relationship of the piston to the driving motor and output spindle, collar or yoke is accomplished with a threaded mechanism such as a micrometer. It should be noted that in priming and purging of air from a liquid metering apparatus of this type maximizing the piston's stroke is advantageous. In addition, a long piston stroke provides increased liquid turbulence within the pumping chamber, a proven benefit for clean in place systems. In order to achieve a long piston stroke, the angular relationship of the piston to the drive spindle must be increased to its maximum limit. After successfully priming or cleaning the pumping apparatus, a time consuming adjustment and calibration procedure is required to restore the pump's output to a desired volumetric displacement.
Traditional rotary reciprocating pump designs accelerate the liquids they are displacing in a manner fixed by the mechanical relationship of the pump to the drive motor and spindle. The displacement of liquid by the piston is a cosine function with the velocity of the liquid at the beginning and end of the intake and discharge strokes being zero. As a result of this velocity profile, the pumping apparatus is unable to eject small volumes of liquid from the dispensing tip.
It is therefore the primary object of the present invention to provide a rotary reciprocating pumping apparatus with a positive two position adjustment feature which will allow the piston's stroke to be preferably automatically increased to a maximum and repeatably, preferably automatically returned to a second, calibrated dispensing position, thereby eliminating time consuming adjustments required with traditional rotary reciprocating pump designs.
An additional object of the invention is to provide such rotary reciprocating pumping apparatus with an adjustable liquid displacement velocity profile to achieve an increase in the velocity of the liquid at the end of the pump's discharge cycle to enable ejection of small amounts of liquid from a dispensing tip, thereby eliminating the inaccurate and time consuming operation of "touching off" a small volume drop of liquid characterizing known pumping systems.
It is a further object of the invention to provide a rotary reciprocating pump having enhanced fluid performance with increased ease of use during pump priming and cleaning.
Other objects and advantages will become apparent from the following detailed description which is to be taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a rotary reciprocating pumping apparatus forming a preferred embodiment of the invention.
FIG. 2 is a perspective view of the pumping apparatus of FIG. 1, partially in section, showing the internal components thereof.
FIG. 3 is a perspective view of the pumping apparatus of FIG. 1, partially in section, showing the pumping module coupled with the drive spindle and motor.
FIG. 4 is a perspective view, partially in section, of the pumping module of FIG. 3, coupled to the drive spindle and angularly oblique thereto similar to that of FIG. 2.
FIG. 5 is a perspective view of the pumping module of FIG. 4 with the drive spindle rotated and the piston slightly retracted from the condition of FIG. 4.
FIG. 6 is a perspective view of the pumping module with the drive spindle further rotated clockwise from that of FIG. 5 and with the piston in full retracted position within the cylinder.
FIG. 7 is a similar perspective view to that of FIG. 6 with the piston further rotated clockwise and extended axially within the cylinder and completing a pumping discharge stroke of the pumping cycle.
FIG. 8 is a graph of piston displacement velocity profile of the piston pump of the pumping apparatus of FIG. 1 superimposed by a displacement velocity profile to modify the normal displacement velocity and the resultant velocity profile effected by such modification.
FIG. 9 is an exploded view of the pump module stabilizing ring assembly and the pump mounting plate of the rotary reciprocating pumping apparatus of FIG. 1, illustrating the mechanism for achieving modification of the velocity profile of the piston pump.
FIG. 10 is a perspective view of the pump module stabilizing ring assembly coupled to the pump mounting plate under conditions in which the pumping apparatus has a modified velocity profile of the piston pump, as illustrated by curve E of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a positive displacement piston pump module forming a preferred embodiment of this invention is shown mounted to a motor and base assembly indicated generally at 2. The motor and base assembly 2 is composed of a suitable inverted T-shaped base bracket 4, to which is attached a drive motor 3, a mounting block 6, and an integral magnet hall effect vane sensor 31.
A drive spindle assembly is composed of a spherical bearing 37, fixedly installed in a radial bore 38A, FIG. 3, of a cylindrical spindle hub 38, and a slotted rotary vane 29 is attached to a reduced diameter boss extending concentrically from the spindle hub 38 via three socket head cap screws 30. The drive spindle assembly is attached to the motor output shaft 44 and secured in place by means of a set screw 39.
Two radially slotted conical pivot bearings 11, one as shown and one (not shown) on a side opposite thereto, are positioned and aligned coaxially with the spherical bearing 37, with the spherical bearing 37 being positioned as shown in FIG. 2. The slotted conical pivot bearings 11 include a narrow radial slot 11A over the axial length thereof, and are thus free to expand and contract radially, are attached to the mounting block 6 with flat head screws 16 which in turn are torqued to expand the radial pivot bearings 11 thereby creating a shake free rotary fit with the surrounding axially aligned bores 10A of the respective side plates 10. The flat head screws 16 are locked in place axially with right angle set screws 32 in tapped bores 32A, after the torque adjustment is made.
The two side plates 10, one as shown and one (not shown) on the side opposite, pivotably mount the pivot bearings 11 and are fixed, respectively, to respective opposite edges 9B of a pump mounting plate 9 with flat head socket cap screws 17. The pump mounting plate 9 on bearing 11 is tiltably adjusted away from the vertical face of mounting block 6 via a fine thread, spherical end thumb screw 14 inserted through a similarly threaded tapped hole 80 in the pump mounting plate 9, with spherical end 14A resting in contact with end 7A of adjustment piston 7. The thumb screw 14 is locked in this calibrated position with a thumb nut 13, threadably mounted on the external threads of thumb screw 14. Tension springs 8, FIG. 1, affixed at one end to the mounting block 6 and at the opposite end to the pump mounting plate 9 provide a biasing force which holds the spherical end 14A of the thumb screw in contact with the end surface 7A of the adjustment piston 7. Loops on the tension springs 8 have transverse small diameter pins 24 passing therethrough, the pins 24 carrying a pair of short length cylinders 25 which fit within a circular recess 83, FIG. 1, to opposite sides of the end loop of each spring 8 to maintain the springs centered. The ends of the pins are received within a longitudinal groove 84 within the front face 9C of the pump mounting plate 9. Each of the tension springs 8 to opposite sides of the thumb screw 14 are so mounted.
The adjustment piston 7, FIG. 2, is stepped with an integral enlarged diameter portion 7B having an annular groove machined into the periphery thereof, fitted with an appropriate elastomeric seal 28. The adjustment piston 7 and seal 28 assembly is slidably fitted into a smooth cylindrical bore 53 and counterbore 55 within mounting block 6. The bore is counterbored at 55 over a given length to an appropriate diameter allowing the seal 28 to create a sliding seal between the adjustment piston 7, radially enlarged piston 7B and the mounting block counterbore 55 and the counterbore 55 terminates in radial shoulders 55A and 55B. Provided in the base bracket 4 and located coaxially with the adjustment piston 7, is a cylindrical chamber 56 with a port hole 5 extending through and to the outer surface of the base bracket 4. Pressurization of this chamber with compressed air, as per arrow B, causes the adjustment piston 7 to be pushed forward, to the right in FIG. 2, in the direction of shoulder 55B, tilting the pump mounting plate 9 about pivot axis A through the center of the flat head screws 16, which in turn positions the piston pump module indicated generally at 1 for maximum piston stroke displacement determined by the length of slots 10B in side plates 10 and the diameter of the shank portions of screws 12. When the chamber 56 is depressurized and the compressed air vented to the atmosphere, the pump mounting plate 9 is pulled back to its calibrated position, to the left in FIG. 2, with the adjusting piston radially enlarged portion 7B abutting shoulder 55A, by the two tension springs 8 which in turn push the adjusting piston 7 back to its maximum retracted position via the spherical end 14A of thumb screw 14.
A stabilizing ring 27 is fitted into a cylindrical counterbore 9A in the face 9C of the pump mounting plate 9 and clamped in place with four circumferentially spaced button head cap screws 19. The stabilizing ring 27 may be angularly positioned about its axis so that its axis is coincident with the axis of the bore and counterbore 9A within pump mounting plate 9. Additionally, the stabilizing ring 27 may be mounted at a predetermined angle to the axis of the aligned pivot bearings 11 to create a predetermined, modified piston displacement velocity profile such as that graphically illustrated at E in FIG. 8.
Two socket head shoulder screws 12, one as shown in FIG. 1 and one on the side opposite, are inserted through slots 10B in the side plates 10, FIG. 1, and threadably attached to the mounting block 6. These shoulder screws serve two functions. First, the shoulder screws 12 provide a feature which limits the angular tilt of the pump mounting plate 9 depending on the length of the slots 10B within side plates 10, through which the shanks of screws 12 pass, in this embodiment 10, when the pump mounting plate 9 is pivoted around the aligned axes A of the pivot bearings 11. Secondly, when the shoulder screws 12 are torqued down, they clamp the side plates to the mounting block 6, thus locking the pumping apparatus in its calibrated position.
As best seen in FIG. 2, the piston pump module, indicated generally at 1, is composed of a pump case 21, a ceramic cylinder 41 carried thereby, an end cap 34, an O-ring 35, an end cap retainer 15, and a ceramic piston 36. The ceramic cylinder 41 is provided with an axial bore 41A which slidably, concentrically, sealably and rotatably carries the piston 36. Additionally, diametrically opposed, small diameter radial passages are formed within the cylinder 41 terminating at flats 58 on the peripheral surface of the ceramic cylinder 41 defining an intake port 57A and a discharge port 57B for the pump. The pump case 21 is provided with an axial counterbore 59 into which the ceramic cylinder 41 is mounted. Threaded, diametrically opposed radial passages 60 to which the intake and discharged ports of the cylinder open are formed within the pump case 21. The ceramic cylinder 41 abuts a shoulder 61 at one end of the counter bore 59, and is closed off by an end cap 34 at the opposite end. The end cap 34 is received within a counterbored recess 62 in the end cap retainer 15 which retainer is held in abutment with the pump case by four screws 26. An O-ring 35 abuts a shoulder at the bottom of a counterbored recess 62 in the end cap retainer 15 and is compressed against the end cap 34 thereby providing the force required to sealably hold the end cap 34 in contact with the end of the ceramic cylinder 41. Liquid supply and discharge tube flanges are sealably connected to the ceramic cylinder 41 by compression fittings (not shown) threaded into the radial passages 60 of the pump case 21.
A laterally projecting drive pin 40 secured to one end of the piston 36 is slidably inserted into the bore of the spherical bearing 37, and the pump module, indicated generally at 1, is mounted to the stabilizing ring 27 with two socket head cap screws, indicated generally at 42, FIG. 1. A reduced diameter boss extends concentrically from the pump case 21 and provides coaxial alignment of the pump module 1 to the drive shaft 44 of the motor 3 when the pump module 1 is inserted into the inner bore of the stabilizing ring 27. A pin 33 affixed to and protruding from the surface of the stabilizing ring 27 ensures the proper angular orientation of the pump module's intake and discharge ports 57A, 57B, respectively.
Referring now to FIG. 3, similar to U.S. Pat. No. 3,168,872 with the piston 36 in a coaxial relationship with the spindle hub 38, the piston will not reciprocate when the motor 3 rotates the spindle hub. With the pumping apparatus in such alignment, no pumping action takes place. Referring to FIG. 4, when the piston pump module is pivoted negatively about axis z, which is coaxial with the pivot bearings 11 (FIGS. 1 and 2), the pump piston 36 will be pivoted in a like manner. Assuming the depicted rotation of the motor shaft 44, the path of travel of the spherical bearing 37, and the resultant reciprocation of the piston 36 will cause fluid to be taken into the pumping chamber through inlet or intake port 57A and to be discharged from the chamber through outlet or discharge port 57B.
FIGS. 4-7 illustrate the cycle of operation of the pumping apparatus when positioned as previously described. In FIG. 4, the piston 36 will be at the end of its forward stroke with both the intake 57A and the discharge 57B ports sealed isolating the pumping chamber from the liquid circuit. As the spindle hub 38 rotates in a counterclockwise direction from motor 3 end, a flatted area 64 on the forward end of the piston 36 will rotate in a like manner opening the pumping chamber 65 to the intake port 57A as the piston 36 is retracted through its intake stroke. FIG. 5 shows the spindle hub 38 rotated 90° counterclockwise, viewed from motor 3, and as a result the piston 36 is positioned one half way through its intake stroke. When the spindle hub 38 and piston 36 rotate to the position illustrated in FIG. 6, the pump piston 36 is at its fully retracted position and both the intake 57A and discharge 57B ports are sealed, isolating the pumping chamber 65, defined by piston 36 and the bore 41A within ceramic cylinder 41, FIG. 6, from the liquid circuit. Continuing to rotate the spindle hub 38 and piston 36 in a counterclockwise direction will bring the flatted area of the piston 36 into communication with the discharge port 57B while the piston 36 extends through its discharge stroke, the chamber 65 decreasing in volume. FIG. 7 shows the piston 36 positioned one half of the way through its discharge stroke.
The present invention is directed to a rotary reciprocating liquid dispensing pump provided with an adjustment mechanism to alter the pump piston displacement profile to ensure that the pumped liquid is moving at significant velocity during pump liquid discharge.
Referring to FIG. 10, the pumps' ceramic cylinder is fixedly assembled into a bore 59, FIG. 2, in the pump case 21, and the end of the cylinder is closed off by an end cap 34, FIG. 2, held in place by an end cap retainer 15, referred to as the pump module 1 in all figures. In turn, this pump module is fixedly attached to a stabilizing ring 27 with socket head cap screws 42, defining a pump module stabilizing ring assembly 1A, FIG. 9.
In the exploded perspective view of FIG. 9, pump mounting plate 9 has a cylindrically counterbored recess 9A centrally located in its face 9C. The pump mounting plate 9 has two circumferentially spaced, raised, sector shaped bosses 77 located on the bottom surface 71 of the cylindrically counterbored recess 9A. Additionally, a cylindrical locating pin 76 protrudes outwardly from the same bottom surface 71 of recess 9A.
In FIG. 9, certain machined in features in the stabilizing ring 27 include a mouse hole shaped notch indicated at 73 within face 27A, radially inwardly of the periphery and diametrically opposed thereto, a second mouse hole shaped notch 73A, two circumferentially spaced, arc shaped corner relief peripheral recesses indicated at 74 to opposite sides of notch 73.
The rotary reciprocating liquid dispensing pump of this invention further includes certain features to allow the pumping mechanism to be assembled in a manner so as to alter the profile of the normal liquid flow velocity curve enabling small liquid volumes to be ejected from the dispense tip at relatively high velocity, the tip being at the outlet end of a tube or the like connected directly to the discharge port of the pump.
Referring again to FIG. 10, the pump module stabilizing ring assembly 1A, FIG. 9, is fitted into the cylindrical counterbore 9A in the face 9C of the pump mounting plate 9 and is clamped in position with four button head cap screws 19, threadably carried by plate 9, FIG. 10. When stabilizing ring 27 is mounted into the pump mounting plate in the orientation shown, the two arc shaped corner relief recesses 74 provide for clearance of the stabilizing ring around the two raised bosses 77 in the bottom 71 of the counterbored recess 9A of the pump mounting plate 9, such that flat face 27A of stabilizing ring 27 lies flush against the bottom 71 of counterbore recess 9A, with notch 73A receiving pin 76.
With the pump module stabilizing ring assembly 1A mounted to the pump mounting plate 9 as per FIG. 9, the pump module 1 operates in accordance with curve C, FIG. 8, and the velocity of the pump liquid at valve cross over is zero. Referring to FIG. 10, the four button head cap screws 19 may be loosened to release the clamping pressure they exert on stabilizing ring 27. Once screws 19 have been loosened, the pump module stabilizing ring assembly 1A can be rotated 180° in either direction and notch 73 may be positioned to receive pin 76.
Referring now to FIG. 10, the mouse hole shaped notch 73 through the stabilizing ring 27 functions in the position of assembly 1A as a keying feature which closely surrounds the cylindrical locating pin 76 protruding from the recessed bottom surface 71 of the pump mounting plate 9. This is after the assembly 1A is first rotated 180° from that of FIG. 9 to that of FIG. 10. The pump module stabilizing ring assembly 1A oriented as shown is then fitted into the cylindrically counterbored recess 9A in the pump mounting plate 9. With the pump module stabilizing ring assembly 1A mounted into the pump mounting plate 9 as shown, the rear or back surface 27A of the stabilizing ring 27 to the side opposite the locating pin 76 is supported by the two raised bosses 77. Raising one side of the stabilizing ring laterally of the axis of the pump assembly serves to tilt the entire pump module stabilizing ring assembly 1A along the X and Z plane, FIG. 3, approximately 0.70 about a displaced axis y at the contact point of the stabilizing ring's outer periphery with the counterbore of the pump mounting plate 9 in the illustrated embodiment. Once raising is achieved, the stabilizing ring 27 is clamped in position in the same fashion against the bottom 71 of counterbore 9A within pump mounting plate 9 as that previously described with respect to the orientation and arrangement of FIGS. 9 and 10 by screwing down the four button head screws 19. Mounting the pump module 1A in this angled position serves to create a piston displacement modifier curve D graphically depicted in FIG. 8. When this modifier curve D is added to the normal displacement curve C, a resultant curve E with a higher flow velocity at the time of valve closure is produced. Closing the discharge valve at the end of the discharge stroke and stopping the flow of liquid when the liquid is at this higher velocity produces a liquid shear required at the dispense tip coupled to exhaust port 57B to eject controlled, set, very small volumes of liquid, thereby enhancing speed of dispensing, while ensuring repeated accurately dispensed microliter sized liquid volumes.
The pump stabilizing ring can be adjusted to achieve the resultant curve E of FIG. 8 through other methods. For example, the lateral tilt of the pumping module stabilizing ring assembly 1A (approximately 0.7°) can be achieved by machining surfaces of the bottom 71 of counter bore 9A and face 27A of stabilizing ring 27 with a 0.35° angle along the X and Z plane with respect to the axis x of the pump module. When the pump module stabilizing ring assembly 1A is mounted to place 9 as described in FIG. 9, these two angled surfaces will offset one another to achieve the normal displacement depicted by curve C in FIG. 8. When stabilizing ring assembly 1A is rotated 180° from that of FIG. 9, the 0.35° angles will combine to produce the 0.7° displaced axis and the resultant curve E as depicted in FIG. 8. Yet another method to achieve the resultant curve E of FIG. 8 is to mount motor 3 of FIG. 1 at a 0.7° angle along the X and Z plane with respect to the axis x of the pump module.
While the description above is to a preferred embodiment and contains specific parameters and connection details, these should not be construed as limitations on the scope of the invention and the system in the various figures is exemplary only. The scope of the invention is determined not by the illustrated embodiment, but by the appended claims and their legal equivalents. As may be further appreciated, various changes may be made to the pump, the pumps being of modular form may be incorporated in a structural assembly of several or more pumps operating under similar principles, but having cyclic pump cycle variations with different modified displacement velocity profiles keyed to repetitive, high speed accurate ejection dispensing of microliter sized volumes of liquid at the discharge port of the pump and thus at the dispense tip at relatively high liquid velocity. | A rotary reciprocating pumping apparatus is provided with a positive two position adjustment feature which allows the piston stroke to be increased to a maximum and repeatably, automatically, returned to a second calibrated dispensing position. Such rotary reciprocating pump is further provided with an adjustable liquid displacement velocity profile to maintain sufficient velocity of liquid flow at the end of the pump discharge cycle to enable injection of small volumes of liquid through a pump exhaust port, thereby eliminating the inaccurate and time consuming operation of touching off a small volume of liquid as a drop characterizing known rotary reciprocating pumping systems. A stabilizing ring of the cylindrical pump case is flush mounted within a counterbore of a pump mounting plate with one side of the ring directly abutting the bottom of the counterbore and a diametrically opposite side and abutting one or more standoffs to set the axis of the pump case and the pumping chamber at a slight angle in a transverse plane to the axis of the counterbore within the pump mounting plate, thereby modifying the pump piston liquid velocity profile to ensure significant fluid velocity at termination of the pump piston discharge stroke. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a pillow construction employed to control a distribution of pressure due to the body weight of a part of a person at rest on the pillow and, more particularly, to such a pillow construction offering the functionally of elastic response to different elastic excursions by the applied pressure of a user's neck and head to consistently maintain a neutral spine alignment of a user in diverse horizontal orientations.
[0004] 2. Description of the Prior Art
[0005] The pillow construction of the present invention maintains the traditional convexly shaped pillow appearance but designed to elastically function in a beneficial manner. FIG. 1 schematically illustrates an individual I in a horizontally orientated, rest position using a conventional pillow P for head and neck support. The pillow is comprised of an elastic mass such as feathers or foamed rubber of which newer materials are foamed latex. The pillow is elastically compressed substantially uniformly along a contact area A 1 by the weight of the head H. Compression of the pillow dramatically increases in area A 2 underlying the neck N and reaches a maximum compression in area A 3 across the area of the shoulder S of the individual because the predominate weight of the shoulder is much greater than that of the head. The pillow compression is greatest under the body weight of the shoulder and as a result there is an over flexion of the neck through an angle a. There is also an inward curvature of the shoulders reducing lung capacity by a narrowing of the airway thus increasing the likelihood of apnea because of poor neck support. When the individual rotates 90 degrees in the horizontal rest position, the unit pressure on the pillow is decreased due to the increased surface area of the side facial area combined with the area of the head. The compression of the pillow is reduced thus raising the head to an elevated location relative to the shoulders producing a forward rotation of the upper torso causing a misalignment. There is the lack of a clear airway which reduces the lung capacity. A need therefore exists for an improved pillow construction to overcome these short comings and disadvantages.
[0006] The pillow of the present invention is a diversion from prior art pillow constructions that feature a sewn or otherwise permanently shaped resilient mass to provide a preformed pillow configuration. Examples of such prior art pillow constructions are disclosed in U.S. Pat. Nos. 2,700,779; 5,088,141; 5,528,784; 5,708,998; 6,003,177; 6,226,818; 6,513,179; 6,539,568; 6,574,809; and 6,629,324. Such prior art pillow constructions may result in rectangular borders but always an irregular shape to the elastic volume containing the special features of one or more depressed sites relative to other resilient areas usually intended to support or otherwise contact the load bearing area of the user's head and sometimes also the user's neck. The designated specific support site or sites provided by such preformed pillow constructions are usually the cause for a required relative positioning of the pillow and the user. The lack of freedom of movement due to the required fixed positioning of the user relative the pillow can cause fatigue and discomforts in the course of sleep. Additionally, improper support for the user's head and neck may interfere with neutral alignment of the body and promote sleep apnea. The preformed construction of such known pillows also produces a differential to the elevation of support for the head and neck of an individual. Generally, there is a very small if any resiliency to adjust the elevation of support for an individual's head when lying in different horizontal orientations. Preformed pillows also fail to adequately support the head at an elevation to prevent forward rotation of the shoulders thus failing to clear the airway with torsionally misalignment and a reduced lung capacity.
[0007] Accordingly, it is an object of the present invention to provide a pillow especially useful for providing support for the head and neck support in a manner designed to maintain the head and body of a person in neutral alignment both laterally and torsionally.
[0008] It is a further object of the present invention to provide a pillow especially useful for providing head and neck support and extension for back sleeping while maintaining musculoskeletal support as well as a clear airway.
[0009] It is a another object of the present invention to provide a pillow especially useful for providing a head and neck support in a state to maintain ease of respiration and reduce torque on the shoulder.
[0010] It is a further object of the present invention to provide a pillow especially useful for providing a head and neck support while maintaining tactility comfort and a luxurious profile.
[0011] It is a further object of the present invention to provide a pillow especially useful for providing a head and neck support useful independent of the orientation of the pillow on a support surface.
SUMMARY OF THE INVENTION
[0012] According to the present invention, there is provided a pillow with convex surface contours along each of a length and a width of a rectangular shaped elastic pillow body containing an internal cavity defined by spaced apart confronting faces bounded by a peripheral margin formed by cavity side walls, the pillow body including internal hinged segments each underlying a parting line generally overlying one of the cavity side walls for altering elastic compression of the elastic pillow body along the convex surface contours between the spaced apart parting lines in response to elastic excursions into the internal cavity by an applied load of a user's neck and head.
[0013] More particularly, the pillow of the present invention comprises a rectangularly shaped elastic pillow body with ellipsoidal surface contours along each of a length and a width divided along a central plane forming divided ellipsoidal parts with plainer faces, and a rectangular shaped elastic spacer having a length and a width corresponding to the length and width of the rectangularly shaped elastic pillow body, the rectangular shaped elastic spacer having a window containing sidewalls with protruding arcuate corners for forming an internal cavity, the divided ellipsoidal parts having elongated internal hinged segments each underlying one of spaced apart parting lines extending in a lengthwise direction of the rectangularly shaped elastic pillow body generally overlying a longitudinal cavity side wall of the internal cavity for varying the compression of the ellipsoidal surface contours transversely of the length thereof between the spaced apart parting lines during elastic excursions into the internal cavity by a user's neck and head.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] The present invention will be more fully understood when the following description is read in light of the accompanying drawings in which:
[0015] FIG. 1 is an elevation partly in section illustrating a prior art from of a pillow;
[0016] FIG. 2 is an isometric illustration of a first embodiment of an elastic pillow body incorporating the features of the present invention;
[0017] FIG. 3 is a sectional view taken along lines III-III of FIG. 2 illustrating the ellipsoidal configuration along the length of the elastic pillow body;
[0018] FIG. 4 is a sectional view taken along lines IV-IV of FIG. 2 illustrating the ellipsoidal configuration along the width of the elastic pillow body;
[0019] FIG. 5 is an isometric illustration of a second embodiment of the present invention;
[0020] FIG. 6 is a elevation view partly in section illustrating the operation of the pillow according to the present invention; and
[0021] FIG. 7 is a partial sectional view taken along lines VII-VII of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0022] In FIG. 2 , there is illustrated a pillow 10 according to the first embodiment of the present invention and includes a pillow case 12 suitably dimensioned to receive a rectangular shaped elastic pillow body 14 . The pillow body is preferably a molding of expanded latex containing uniformly spaced tubular relief penetrating the entire thickness of the molded mass. The pillow body can take the form of a unitary structure comprised of the construction and arrangement of structure for altering elastic compression of the elastic pillow body along the convex surface contours as will be described in greater detail. The physical properties of the material for producing the pillow case 12 are particularly important to wholly utilize the structured elastically responsive support by the pillow body 14 . Also, the elastic response by the pillow body 14 to the applied load is highly dependent on the use of a fabric with elastic properties for constructing the pillow cover to transmit the elastic changes by the pillow to the user. The use of stretch cotton is one suitable material to form the pillow case 12 .
[0023] Preferably, and for the purposed of disclosing the preferred embodiment of the present invention, the pillow body 14 is made up of three discrete components, namely face components 16 and 18 having a rectangular, hemi ellipsoidal compression face 20 and 22 , respectively, each terminating at one of the generally plainer faces 24 and 26 . A rectangular elastic frame 28 contains a window 30 defined by rectangular sidewalls 32 merging at junction areas with protruding actuate corners 34 . The planar faces 24 and 26 are adhered to opposite sides of the rectangular elastic frame 28 by the use of a suitable adhesive well known whereby the rectangular, hemi ellipsoidal compression faces 20 and 22 protrude in opposite directions, one of which forms a load bearing surface for contact with the head and neck areas of the user and the other for support by a mattress or other horizontally arranged surface. The present invention allows any of various shaped pillow bodies within a rectangular shaped perimeter. FIGS. 3 and 4 illustrate the geometry applied across the length and width to the pillow for the defining a standard, well known ellipsoidal shape of which the major radii R 1 have much greater lengths than the lengths of the minor radii R 2 . As a result, the pillow exhibits a symmetrical configuration both longitudinal and transverse of the rectangular pillow body which avoids a requirement for turning the pillow to accommodate normal movement of the users head from side to side as well as a need for constant readjustments to the positions of the pillow and the head.
[0024] FIGS. 2-4 illustrate further details of construction of the pillow by the provision of spaced apart and parallel longitudinal cut lines 36 and 38 and spaced apart and parallel transverse cut lines 40 and 42 that extend in the direction of the width of the pillow. These cut lines reside in marginal areas spaced inward from the terminal pillow edges to overly but, terminating remote to the rectangular side walls 32 of the rectangular elastic frame 28 . The distance 44 separating the cut lines forms an internal, natural hinge linking the central load bearing area 46 of the pillow body bordered by the cut lines and overlying the natural hinges. Area 46 is not only compressible but also the compressed area of the pillow mass is displaceable into the area of the internal cavity 30 and thereby provide a depressed area to maintain displaced head and neck support areas in the pillow body. The cuts lines overlying each hinge function to form a barrier to the propagating elastic compression caused by the forces imposed on the pillow by the body and to reduce the surface tension in the convex surface of the pillow. The decreased surface tension also reduces direct facial contact pressure. The reduction in surface tension provides a more stable contour providing torsionally support as well as a more neutral alignment. The construction of the pillow of the present invention may be dimensioned and shaped the same as a conventional 24″×17″×5″ rectangular pillow including the initial tactile response. The support for the head and neck on the pillow is distinct from the an actual physical relief in prior art forms of pillows due to the pillow design responsive to the internal cavity reactive to the cut lines and the natural internal hinges.
[0025] FIG. 5 illustrates a further embodiment of the present invention which differs from the embodiment shown in the FIGS. 2-4 essentially by constructing the rectangular elastic frame 28 A with the rectangular sidewalls 32 A with a thickness T with a materially greater thickness of the sidewalls 32 . An illustrative example of the thickness T is a dimension in the range of between two and three inches whereas the thickness of the frame 28 can be in the rang of one an one and one half inches. The volume of the widow 30 A is increased for providing added capacity to alter the elastic compression of the elastic pillow body 14 A along the convex surface contours between the spaced apart cut lines 36 A, 38 A, 40 A and 42 A in response to elastic excursions into the internal cavity by an applied load of a user's neck and head.
[0026] FIGS. 6 and 7 illustrate the support provided by for the head neck and shoulder of an individual by the pillow of the present invention. FIG. 6 schematically illustrates an individual I in a horizontally orientated, rest position using the pillow 14 for head and neck support. The pillow is elastically compressed to a varying extent as shown along contact area generally comprising the central load bearing area 46 . The longitudinal and transverse internal hinged segments 44 each underlying one of parting lines 36 , 38 , 40 and 42 function to allow an elastic compression of the central load bearing area 46 and elastic displacement of the compressed area into the internal cavity provided by the window 30 . The actuate corners 34 provide torsionally stability under the jaw and forehead, especially for people who move forward on the pillow. The cut under the neck seals shut under direct pressure and has no negative function. Only the cut above the head is operational. The parting lines allow for varying the compression of the ellipsoidal surface contours transversely of the length thereof between the spaced apart parting lines by the user's neck and head. Also as shown, the compression of the pillow body in the area of the shoulders is allowed independently by the compression of the pillow by the head preventing flexion of the neck and thereby avoiding restrictions to the airway by maintaining a relaxed extension to the head and neck forming an angle B which clears the airway and provides and expanded lung capacity particularly by the position of the shoulders rearward of the chest cavity. With this sleep posture there is a decreased chance of sleep apnea and reduced likelihood of muscular pressure because of good neck support. When the individual rotates 90 degrees in the horizontal rest position as shown in FIG. 7 , the pillow of the present invention undergoes decreased elastic compression thus maintaining the head at an elevation that avoids a torso twisting of the shoulders causing the unwanted forward rotation of the upper torso causing a misalignment produced in a pillow according to prior art. The pillow of the present invention also allows a more accurate conformation of either the rear of the head or the side of the head during side sleeping.
[0027] While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating there from. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims. | A pillow with ellipsoidal surface configurations between each of a length and a width of a rectangularly shaped peripheral boundary. An elastic frame provides an internal cavity between sidewalls joined by protruding arcuate corners for receiving an elastically displaced overlying internal mass. This mass is bounded by elongated internal hinged segments terminating at spaced apart parting lines extending in the direction of the length and width of the rectangular pillow boundary. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for producing optically active 3-substituted-2-norbornanones which are useful as starting materials for several kinds of physiologically active materials, and to the intermediates, optically active 2-hydroxy-2-norbornanecarboxylic acid and to a method for producing these intermediates. As an example, a thromboxane A 2 receptor antagonist useful as an anticoagulant can be synthesized from the above norbornanone. (Narisada et al., J. Med. Chem., 31, 1847(1988), Hamanaka et al., Tetrahedron Lett., 30, 2399(1989)).
2. Description of the Prior Art
Recently the synthesis of physiologically active materials as optically active compounds has become important. When a material has optical isomers, the activities are generally different among isomers. However, only one isomer usually shows strong activities and the other isomers show weak activities or undesired toxicity in many cases. Accordingly, when the plysiologically active materials are especially synthesized for medical supplies, it is required that desired optical isomers are selectively synthesized in order to develop sufficient physiological activities in safety.
To efficiently synthesize optically active 3-substituted-2-norbornanones of the present invention, it is necessary to efficiently obtain optically active 2-norbornanones. As for the synthesis of optically active 2-norbonanones, (1) a optical resolution method of racemic endo- or exo-2-norbornanol by using a diastereomer process (Winstein et al., J. Am. Chem. Soc., 74, 1147(1952), Berson et al., ibid., 83 3986(1961).), (2) a method of asymmetric oxidation or asymmetric reduction of racemic exo-2-norbornanol or 2-norbornanone with a horse liver alcohol dehydrogenase (Irwin et al., J. Am. Chem. Soc., 98, 8476(1976) and the like are reported. However, the method (1) is not efficient because recrystallization of the product should be repeated to improve the optical purity. The method (2) is not practical because a reagent to be used is expensive and the asymmetric yield of the product is low.
As described above, all of these cases are not satisfactory to practice on an industrial level.
For the above reasons, development of a simple process for producing optically active 3-substituted-2-norbornanone widely useful as synthetic intermediates of physiologically active materials has been long-desired.
SUMMARY OF THE INVENTION
The inventors of the present invention had a research for attaining an object to efficiently obtain a large amount of optically active 3-substituted-2-norbornanone, so that they found a production method for efficiently obtaining a large amount of optically active 3-substituted-2-norbornanones represented by the formula (II) below by using intermediates, such as optically active 2-hydroxy-2-norbornane carboxylic acids represented by the formula (III) below. The optically active 2-hydroxy-2-norbornane carboxylic acids are found by the inventors of the present invention, and these compounds are new. Although the synthesis of racemates of these compounds was reported (K. B. Wiberg (ed.), Oxidation in Organic Chemistry, Part A, Chapter I (page 2), Academic Press, New York/London), efficient synthesis of optically active compounds of the present invention which is industrially excellent is not yet known.
The present invention provides a method for producing an optically active 3-substituted-2-norbornanone represented by the formula: ##STR1## wherein R 4 is an alkyl, alkenyl, alkynyl, aryl or aralkyl group comprising reacting an optically active acrylic ester represented by the formula: ##STR2## wherein R 1 is a member selected from the group consisting of ##STR3## (wherein R 2 and R 3 are alkyl of 1-6 carbon atoms, cycloalkyl or aryl, respectively, or cyclic alkyl of 6 or less carbon atoms in combination, and * shows an asymmetric carbon) with cyclopentadiene, and applying the obtained compound to five steps consisting of hydrolysis, catalytic hydrogenation, oxidation, oxidative decarboxylation and alkylation.
Further, the present invention provides method for producing an optically active 2-hydroxy-2-norbornane carboxylic acid represented by the formula: ##STR4## comprising reacting an optically active acrylic ester represented by the formula: ##STR5## wherein R 1 is ##STR6## (wherein R 2 and R 3 are alkyl of 1-6 carbon atoms, cycloalkyl or aryl, respectively, or cyclic alkyl of 6 or less carbon atoms in combination, and * shows an asymmetric carbon) with cyclopentadiene, and applying the obtained compound to three steps consisting of hydrolysis, catalytic hydrogenation and oxidation. Further, the present invention provides the final product, namely, optically active 2-hydroxy-2-norbornane carboxylic acid.
In addition, the present invention provides an optically active 2-norbornanone represented by the formula: ##STR7## which is obtained from an optically active 2-hydroxy-2-norbornane carboxylic acid represented by the formula: ##STR8##
The method for producing the optically active compounds of the present invention is described in more detail below.
Optically active 3-substituted-2-norbornanone (II) of the present invention can be produced by the following reaction processes. ##STR9## wherein R 1 is ##STR10## (wherein R 2 and R 3 are alkyl of 1-6 carbon atoms, cycloalkyl or aryl, respectively, or cyclic alkyl of 6 or less carbon atoms in combination, * shows an asymmetric carbon), R 4 is alkyl, alkenyl, alkynyl, aryl or aralkyl, and M is hydrogen or a metal atom selected from the group consisting of lithium, sodium, potassium and the like.
The starting compound (I) of the present invention having excellent optical purity can be obtained by a reaction of acrylic chloride with (S)-lactate, (R)-(-)-pantoyl lactone, (S)-(-)-N-methyl-2-hydroxysuccinimide or the like (Poll et al., Tetrahedron Lett., 25, 2191(1984); 30, 5595(1989).).
The compound (V) can be synthesized by a Diels-Alder reaction of cyclopentadiene with the compound represented by the formula (I) in the presence of a Lewis acid catalyst. As the catalyst used in the reaction, titanium tetrachloride can be exemplified. As a reaction solvent, a halogen type solvent such as methylene chloride, chloroform or dichloroethane or a mixture solvent of the halogen type solvent and a hydrocarbon type solvent such as pentane, hexane, heptane or petroleum ether can be used. The reaction temperature is suitably -78° C. to room temperature, especially preferably -20° to 0° C.
The compound represented by the formula (V) can be easily converted into the compound (VI) by hydrolysis under basic conditions.
Lithium hydroxide, sodium hydroxide and potassium hydroxide can be exemplified as the bases used in the reaction. An ether type solvent such as tetrahydrofuran, or a mixture solvent of the ether type solvent and an alcohol type solvent such as methanol, ethanol or solmix can be used as the reaction solvent. The reaction temperature is suitably 0° to 50° C., and especially preferably about 20° to 30° C.
The compound represented by the formula (VII) can be easily obtained by catalytic hydrogenation of the compound (VI). As the catalyst used in the reaction, palladium-carbon can be exemplified. Water, an alcohol type solvent such as methanol, ethanol or solmix, or a mixture thereof can be used as the reaction solvent. The reaction temperature is suitably 0° to 50° C., and preferably room temperature.
The compound represented by the formula (III) can be obtained by oxidizing the compound (VII). As the oxidizing agent used in the reaction, potassium permanganate can be exemplified. As the reaction solvent, water, or two phases of water and a hydrocarbon type solvent such as pentane, hexane, heptane or petroleum ether can be used. The reaction temperature is suitably 0° to 100° C., and especially preferably a temperature from room temperature to 70° C.
By the above operation, optically active 2-hydroxy-2-norbornanecarboxylic acid (III) can be prepared.
Moreover, the compound represented by the formula (IV) can be easily obtained by oxidizing the compound (III). As the oxidizing agent used in the reaction, sodium bismuthate-phosphoric acid, lead tetraacetate, chromic acid-sulfuric acid can be exemplified. These oxidizing agents can be used by a common method. As an example, when sodium bismuthate-phosphoric acid is used as the oxidizing agent, water may be used as a reaction solvent and the reaction temperature is preferably a temperature of from room temperature to 60° C.
The compound represented by the formula (II) can be easily obtained by enolization of the compound (IV) and then reaction with a halogenated alkyl. As the base used in the enolization, lithium diisopropyl amide (LDA) or lithium bis(trimethylsilyl)amide can be exemplified. As the halogenated alkyls, methyl chloride, methyl bromide, methyl iodide, allyl chloride, allyl bromide, allyl iodide, benzyl chloride, benzyl bromide, benzyl iodide, vinyl chloride, vinyl bromide, vinyl iodide, etc. can be exemplified. An ether type solvent such as tetrahydrofuran can be used as the reaction solvent. The reaction temperature is suitably -78° C. to room temperature, especially preferably -20° to 0° C.
By the above operation, optically active 3-substituted-2-norbornanone (II) can be prepared.
Typical compounds of obtained optically active 3-substituted-2-norbornanones are as follows:
(+)-3-methyl-2-norbornanone, (+)-3-ethyl-2-norbornanone,
(+)-3-allyl-2-norbornanone, (+)-3-vinyl-2-norbornanone,
(+)-3-benzyl-2-norbornanone, (+)-3-phenyl-2-norbornanone,
(-)-3-methyl-2-norbornanone, (-)-3-ethyl-2-norbornanone,
(-)-3-allyl-2-norbornanone, (-)-3-vinyl-2-norbornanone,
(-)-3-benzyl-2-norbornanone, (-)-3-phenyl-2-norbornanone, etc.
Optically active 2-hydroxy-2-norbornane carboxylic acid of the present invention is a new compound which is firstly prepared by the inventors of the present invention. From the compound, a large amount of optically active 3-substituted-2-norbornanones which are useful for synthetic intermediates for physiologically active materials can be efficiently obtained. As an example, from optically active 3-allyl-2-norbornanone, thromboxane A 2 receptor antagonists (VIII) and (IX) useful for a blood coagulation inhibitor can be prepared via several steps. The (+)-type compound shows the highest activity. Concerning the compound (VIII), the activity of the racemate is one-third of that of the (+)-type compound and the activity of the (-)-type compound is only one-thirtieth of that of the (+)-type compound (Narisada et al., J. Med. Chem, 31, 1847(1988)). Accordingly, in order to obtain sufficient activity, it is essential to synthesize an optically active compound, especially a (+)-type compound. According to the present invention, (+)-3-allyl-2-norbornanone having high optical purity can be easily prepared with easily available asymmetric sources, low-priced materials and reagents.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the present invention more specifically, but the present invention is not limited by these examples.
Example 1
Preparation of (+)-2-hydroxy-2-norbornanecarboxylic acid
Step 1
To a mixture of 69.5 g (538 mmol) of (S)-(-)-N-methyl-2-hydroxysuccinimide, 70.8 g (700 mmol) of triethylamine and 400 ml of methylene chloride, 63.4 g (700 mmol) of acryloyl chloride was dropwise added at a temperature of -25° C., and the mixture was stirred for 4.5 hours at -20° to -25° C. 170 ml of 1N hydrochloric acid was added to the reaction mixture on an ice bath to separate an organic layer and an aqueous layer, and the aqueous layer was extracted with methylene chloride (200 ml×3). After combining organic layers, the organic solution was washed with 150 ml of a saturated aqueous solution of sodium bicarbonate and then with 150 ml of a saturated aqueous solution of sodium chloride. After the organic solution was dried on anhydrous magnesium sulfate, the solvent was filtered off and 96.8g of crude acrylic acid ester was obtained.
The product was purified by silica gel chromatography (elution with ethyl acetate), and 72.2 g (394 mmol) of (S)-(-)-N-methyl-2-propenoyloxysuccinimide was obtained. Yield: 73%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ2.6-3.5 (m, 2H), 3.0 (s, 3H), 5.5-5.7 (m, 1H), 5.8-6.7 (m, 3H).
Step 2
72.2 g (394 mmol) of (S)-(-)-N-methyl-2-propenoyloxysuccinimide was dissolved in 580 ml of a mixture solvent of methylene chloride-petroleum ether (7:1), and 4.4 ml (40.1 mmol) of titanium tetrachloride in 30 ml of petroleum ether was added at -15° C. After the mixture was stirred at -10° to -15° C. for 30 minutes, 32.4 g (490 mmol) of cyclopentadiene prepared prior to the use was added dropwise and the mixture was stirred at the same temperature for 3.5 hours. After adding 50.1 g (175 mmol) of sodium carbonate 10 H 2 O powder in limited amounts to the mixture, the temperature was slowly raised to room temperature, and the mixture was stirred for one hour. Insoluble materials were filtered and washed with methylene chloride (250 ml×3). The filtrate and the washed liquid were distilled off, and 99.6 g of crude Diels-Alder adduct was obtained. The adduct was recrystallized from 600 ml of a mixture solvent of heptane-ethyl acetate (5:3) to obtain 67.0 g (269 mmol) of a purified Diels-Alder adduct. Yield: 68%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-2.2 (m, 4H), 2.4-3.4 (m, 5H), 3.0 (s, 3H), 5.3-5.5 (m, 1H), 5.8-6.0 (m, 1H), 6.1-6.3 (m, 1H).
Further, the physical property values are as follows.
Melting point: 134.9°-136.6° C.
Specific rotation: +85.2° (c 1.037, CHCl 3 ).
Step 3
67.0 g (269 mmol) of the Diels-Alder adduct was dissolved in 1040 ml of a mixture solvent of tetrahydrofuran-water (5:2), 70.5 g (1.08 mol) of potassium hydroxide (85%) in 300 ml of water was added on ice cooling, and the mixture was stirred at room temperature for 24 hours. After distilling out tetrahydrofuran, the product was neutralized with 94 ml of concentrated hydrochloric acid and extracted with a mixture solvent of hexane-methylene chloride (98:2) (200 ml×4). The extract was dried on anhydrous magnesium sulfate, the solution was filtered, and the solvent was distilled off to obtain 38.8 g of crude 5-norbornene-2-carboxylic acid. Crude yield: 100%.
The product was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following:
1 H-NMR: δ1.1-1.6 (m, 3H), 1.7-2.1 (m, 1H), 2.7-3.3 (m, 3H), 6.0 (dd, 1H), 6.2 (dd, 1H), 11.4 (brs, 1H).
Further, a part of the product was purified by distillation. The physical property values are as follows:
Melting point: 84° C./1 mmHg
Specific rotation: +142.0° (c 5.02, EtOH).
Step 4
38.8 g (269 mmol) of crude 5-norbornene-2-carboxylic acid was dissolved in 740 ml of solmix, 1.92 g of 5% palladium-carbon powder was added and the mixture was stirred for 17.5 hours under an atmosphere of hydrogen. The catalyst was filtered off, the solvent was distilled away, and 38.0 g of crude 2-norbornanecarboxylic acid was obtained. Crude yield: 100%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following
1 H-NMR: δ1.1-1.9 (m, 8H), 2.2-2.4 (m, 1H), 2.5-3.0 (m, 2H), 11.0 (brs, 1H).
Further, a part of the product was purified by distillation. The physical property values are as follows:
Boiling point: 96° C./2 mmHg
Specific rotation: +38.5° (c 1.933, CHCl3).
Step 5
107 g (1.63 mol) of potassium hydroxide (85%) and 85.7 g (542 mmol) of potassium permanganate were dissolved in 380 ml of water, and 37.9 g (271 mmol) of crude 2-norbornanecarboxylic acid in 380 ml of petroleum ether was added dropwise on ice cooling. After heating and refluxing for eight hours, the mixture was stirred at room temperature for 18 hours. The reaction mixture was slowly added to 544 ml of 6N sulfuric acid, to obtain acidified mixture, then 272 ml of an aqueous solution of 62.2 g of sodium bisulfite was added, and the mixture was stirred at room temperature for one hour. After the reaction mixture was extracted with ethyl acetate (200 ml×4), the extract was dried over anhydrous magnesium sulfate. The extract was filtered, the solvent was distilled off and 38.5 g of crude 2-hydroxy-2-norbornanecarboxylic acid was obtained. Crude yield: 92%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.0-2.3 (m, 10H), 7.4 (brs, 2H).
Further, the physical property values are as follows:
Melting point: 90°-94° C.
Specific rotation: +27.7° (c 1.076, EtOH).
Example 2
Production of (+)-2-hydroxy-2-norbornanecarboxylic acid
Step 1
5.00 g (20.0 mmol) of the Diels-Alder adduct obtained in Step 2 of Example 1 was suspended in 40 ml of a mixture solvent of tetrahydrofuran-methanol (1:1), 1.86 g (43.3 mmol) of sodium hydroxide (93%) in 4 ml of water was added, and the mixture was stirred for 24 hours. Then, 280 mg of 5% palladium-carbon powder was added, and the mixture was stirred for 5 hours under an atmosphere of hydrogen. The catalyst was filtered off, the solvent was distilled off, and the residue was diluted with water. The solution was acidified with concentrated hydrochloric acid and extracted with a mixture solvent of hexane-methylene chloride (98:2) (50 ml×4). The extract was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 2.67 g of crude 2-norbornanecarboxylic acid was obtained. Crude yield: 95%.
The compound was identified by 1 H-NMR chart analysis.
Step 2
9.59 g (68.4 mmol) of crude 2-norbornanecarboxylic acid obtained by the above step was dissolved in 50 ml of water, 4.55 g (68.9 mmol) of potassium hydroxide (85%) was added on ice cooling, and the mixture was stirred for six hours. The reaction solution was added dropwise in a mixture of 30.0 g (456 mmol) of potassium hydroxide (85%), 23.4 g (148 mmol) of potassium permanganate and 50 ml of water. After heating and stirring at 40°-50° C. for nine hours, the mixture was stirred at room temperature for 18 hours. The product was treated by the same method as described in Step 5 of Example 1, and 9.51 g of crude 2-hydroxy-2-norbornanecarboxylic acid was obtained. Crude yield: 89%.
The compound was identified by 1 H-NMR chart analysis.
Example 3
Production of (+)-2-hydroxy-2-norbornanecarboxylic acid
Step 1
5.00 g (20.0 mmol) of the Diels-Alder adduct obtained by the step 2 of Example 1 was dissolved in 45 ml of a mixture solvent of tetrahydrofuran-water (5:4), 1.85 g (43.0 mmol) of sodium hydroxide (93%) was added on ice cooling, and the mixture was stirred at room temperature for 24 hours. After tetrahydrofuran was distilled off, the reaction mixture was neutralized with concentrated hydrochloric acid. Then, 280 mg of 5% palladium-carbon powder was added and the mixture was stirred for 30 hours under an atmosphere of hydrogen. The catalyst was filtered off, the filtrate was acidified with concentrated hydrochloric acid and extracted with a mixture solvent of hexane-methylene chloride (98:2) (50 ml×4). The extract was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 2.66 g of crude 2-norbornanecarboxylic acid was obtained. Crude yield: 95%.
The compound was identified by 1 H-NMR chart analysis.
Step 2
1.83 g (13.1 mmol) of crude 2-norbornanecarboxylic acid obtained by the above step was dissolved in 10 ml of water, 0.87 g (13.1 mmol) of potassium hydroxide (85%) was added on ice cooling, and the mixture was stirred for six hours. The reaction solution was added dropwise in a mixture of 5.22 g (79.5 mmol) of potassium hydroxide (85%), 4.57 g (28.9 mmol) of potassium permanganate, 10 ml of water and 20 ml of hexane. After heating and stirring at 40°-50° C. for eight hours, the mixture was stirred at room temperature for 18 hours. The product was treated by the same method as described in Step 5 of Example 1, and 1.74 g of crude 2-hydroxy-2-norbornanecarboxylic acid was obtained. Crude yield: 85%.
The compound was identified by 1 H-NMR chart analysis.
Example 4
Production of (+)-5-norbornene-2-carboxylic acid
Step 1
To a mixture of 59.0 g 499 mmol) of (S)-(-)-ethyl lactate, 55.7 g (550 mmol) of triethylamine and 200 ml of methylene chloride, 49.8 g (550 mmol) of acryloyl chloride in 100 ml of dichloroethane was added dropwise at a temperature of -20° C., and the mixture was stirred at -20° C. for 4.5 hours. On ice cooling, the reaction mixture was separated into an organic layer by adding 1N hydrochloric acid, and an aqueous layer was extracted with methylene chloride. Organic layers were combined, and washed with successive, saturated sodium bicarbonate solution, water, and saturated sodium chloride solution.
The product solution was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 75.0 g of crude (S)-ethyl 2-propenoyloxypropionate was obtained.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.3 (t, 3H), 1.5 (d, 3H), 4.2 (q, 2H), 5.1 (q, 1H), 5.8-6.6 (m, 3H).
Further, a part of the product was purified by distillation. The physical property values are as follows:
Boiling point: 68° C./8 mmHg
Specific rotation: -38° c 2.1, CHCl 3 ).
Step 2
67.5 g (382 mmol) of crude (S)-ethyl 2-propenoyloxypropionate was dissolved in 150 ml of methylene chloride, and 5.0 ml (45.6 mmol) of titanium tetrachloride in 30 ml of hexane was added at a temperature of -20° C. The mixture was stirred at -10° C. for 30 minutes, 31.1 g (470 mmol) of cyclopentadiene in 50 ml of methylene chloride which was prepared just prior to the use was added dropwise, and the mixture was stirred at the same temperature for two hours. After adding 20.0 g (69.9 mmol) of sodium carbonate 10 H 2 O powder in limited amounts, the temperature of the mixture was slowly raised to room temperature, and the mixture was stirred overnight. Insoluble materials were filtered and washed with methylene chloride. The filtrate and the washed liquid were combined, and the solution was washed with successive, saturated sodium bicarbonate, and water. The solution was dried over magnesium sulfate and filtered, the solvent was distilled off, and 95.0 g of crude Diels-Alder adduct was quantitatively obtained.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-1.5 (m, 10H), 2.6-3.1 (m, 3H), 4.3 (q, 2H), 5.1 (q, 1H), 6.0-6.2 (m, 2H).
Step 3
95.0 g (382 mmol) of the Diels-Alder adduct obtained in the above step was dissolved in 950 ml of tetrahydrofuran, 103 g (1.57 mol) of potassium hydroxide (85%) in 760 ml of water was added on ice cooling, and the mixture was stirred at room temperature for 24 hours. After tetrahydrofuran was distilled off from the reaction mixture, the residue was neutralized with 138 ml of concentrated hydrochloric acid, and the solution was extracted with a mixture solvent of hexane-methylene chloride (98:2) (200 ml×4). The extract was dried over anhydrous magnesium sulfate and filtered, the distilled off, and 45.0 g of crude 5-norbornene-2-carboxylic acid was obtained. Crude yield: 83%.
The compound was identified by 1 H-NMR chart analysis.
Further, the steric configuration of the compound was a (+)-compound by the sign of the optical rotation.
Example 5
Production of (+)-5-norbornene-2-carboxylic acid
Step 1
To a mixture of 10.1 g (58.5 mmol) of cyclohexyl (s)-(-)-lactate, 8.1 g (80.4 mmol) of triethylamine and ml of methylene chloride, 5.7 ml (70.2 mmol) of acryloyl chloride was added dropwise at a temperature of -20° C., and the mixture was stirred at -20° C. for 5.5 hours. On ice cooling, 1N hydrochloric acid was added to the reaction mixture to separate an organic layer, and an aqueous layer was extracted with methylene chloride. Organic layers were combined and washed with successive, saturated sodium bicarbonate solution, water, and saturated sodium chloride solution. The solution was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 13.5 g of crude (S)-cyclohexyl 2-propenoyloxypropionate was obtained.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.1-2.2 (m, 10H), 1.5 (d, 3H), 4.7-5.0 (m, 1H), 5.1 (q, 1H), 5.8-6.6 (m, 3H).
Step 2
13.5 g (58.5 mmol) of crude (S)-cyclohexyl 2-propenoyloxypropionate was dissolved in 60 ml of a mixture solvent of methylene chloride-hexane (5:1), and 0.7 ml (6.4 mmol) of titanium tetrachloride was added at a temperature of -20° C. The mixture was stirred at -10° C. for 30 minutes, 6.1 g (92.6 mmol) of cyclopentadiene prepared just prior to the use was added dropwise, and the mixture was stirred at the same temperature for 4.5 hours. After adding 8.1 g (28.4 mmol) of sodium carbonate 10 H 2 O powder in limited amounts to the mixture, the temperature was slowly raised, and the mixture was stirred at room temperature overnight. Insoluble materials were filtered and washed with methylene chloride. The filtrate and the washed liquid were combined, and the solution was washed with successive, saturated sodium carbonate, and water. The solution was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 19.1 g of crude Diels-Alder adduct was quantitatively obtained.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.1-2.2 (m, 14H), 1.5 (d, 3H), 2.6-3.4 (m, 3H), 4.2-5.0 (m, 1H), 5.0 (q, 1H), 5.8-6.3 (m, 2H).
Step 3
19.0 g (58.5 mmol) of the Diels-Alder adduct was dissolved in 115 ml of tetrahydrofuran, 12.9 g (300 mmol) of sodium hydroxide in 140 ml of water was added on ice cooling, the mixture was stirred at room temperature for 24 hours. After distilling off tetrahydrofuran, the product was neutralized with 27 ml of concentrated hydrochloric acid and extracted with a mixture solvent of hexane-methylene chloride (98:2) (100 ml×4). The extract was dried over anhydrous magnesium sulfate, the solution was filtered, and the solvent was distilled off to obtain 8.3 g of crude 5-norbornene-2-carboxylic acid.
The compound was identified by 1 H-NMR chart analysis.
Further, the steric configuration of the compound was a (+)-compound by the sign of the optical rotation.
Example 6
Production of (+)-exo-3-allyl-2-norbornanone
Step 1
38.5 g (247 mmol) of crude 2-hydroxy-2-norbornanecarboxylic acid and 90.6 g (259 mmol) of sodium bismuthate (80%) were dissolved in 400 ml of water, 83.9 g (728 mmol) of phospholic acid (85%) was added dropwise, and the mixture was stirred at 45° to 50° C. for six hours and then at room temperature for 18 hours. The reaction mixture was extracted with ethyl acetate (200 ml×4), and the extract was washed with successive, saturated sodium bicarbonate solution, water and saturated sodium chloride solution (each 200 ml), and dried over anhydrous magnesium sulfate. After ethyl acetate was distilled off at atmospheric pressure, and the residue was distilled to obtain 14.8 g (134 mmol) of (+)-2-norbornanone. Yield 50%.
The compound was identified by 1 H-NMR chart analysis The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-2.3 (m, 8H), 2.5-2.9 m, (2H).
Further, the physical property values are as follows:
Boiling point: 174° C.
Specific rotation: +29.0° (c 1.51, CHCl 3 ).
Step 2
To 194 ml (388 mmol) of a 2M solution of lithium diisopropyl amide in tetrahydrofuran-hexane, 50 ml of a solution of 38.9 g (353 mmol) of (+)-2-norbornanone in tetrahydrofuran was added dropwise at -40° C., and the mixture was stirred at -20° C. for 30 minutes. Then, 30 ml of a solution of 47.0 g (388 mmol) of allyl bromide in tetrahydrofuran was added dropwise, the mixture was stirred at -20° C. for 30 minutes, the temperature of the mixture was raised to room temperature, and the mixture was stirred for one hour. On ice cooling, the reaction mixture was poured into 300 ml of 2N hydrochloric acid, and the mixture was extracted with toluene (200 ml×4). The extract was washed with successive, saturated sodium bicarbonate solution, water, saturated sodium chloride (each 200 ml), and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was distilled off to obtain 77.6 g of crude 3-allyl-2-norbornanone. The crude product was purified by distillation, and 42.5 g (134 mmol) of (+)-exo-3-allyl-2-norbornanone was obtained. Yield: 80%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-2.8 (m, 11H), 4.9-5.3 (m, 2H), 5.6-6.1 (m, 1H).
Further, the physical property values are as follows:
Boiling point: 71°-72.5° C./3 mmHg
Specific rotation: +87.3° (c 1.08, CHCl 3 ).
Example 7
Production of (-)-2-hydroxy-2-norbornanecarboxylic acid
Step 1
To a mixture of 46.8 g (360 mmol) of (R)-(-)-pantoyllactone, 54.7 g (541 mmol) of triethylamine and 300 ml of methylene chloride, 41.2 g (455 mmol) of acryloyl chloride was added dropwise at -25° C., and the mixture was stirred at -20° to -25° C. for five hours. On ice cooling, 500 ml of 0.5N hydrochloric acid was added to the reaction mixture to separate an organic layer, and an aqueous layer was extracted with methylene chloride (150 ml×3). Organic layers were combined and washed with successive, saturated sodium bicarbonate solution, water, and saturated sodium chloride solution (each 250 ml). The solution was dried over magnesium sulfate and filtered, and the solvent was distilled off to obtain 64.5 g of crude acrylic acid ester. The product was purified by silica gel column chromatography (hexane-ethyl acetate 3:1), and 61.3 g (333 mmol) of (R)-dihydro-3-propenoyloxy-4,4-dimethyl-2(3H)-furanone was obtained. Yield: 93%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.1 (s, 3H), 1.3 (s, 3H), 4.0 (s, 2H), 5.5 (s, 1H), 5.9-6.7 (m, 3H).
Step 2
25.1 g (136 mmol) of (R)-dihydro-3-propenoyloxy-4,4-dimethyl-2(3H)-furanone was dissolved in 200 ml of a mixture solvent of methylene chloride-petroleum ether (7:1), and 1.6 ml (14.6 mmol) of titanium tetrachloride was added at -15° C. The mixture was stirred at -10° to -15° C. for 30 minutes, 11.9 g (180 mmol) of cyclopentadiene prepared just prior to the use was added dropwise to the mixture, and the mixture was stirred at the same temperature for three hours. After adding 17.3 g (60.4 mmol) of sodium carbonate 10 H 2 O powder in limited amounts to the reaction mixture, the temperature was slowly raised, and the mixture was stirred at room temperature for 30 minutes. Insoluble materials were filtered and washed with methylene chloride (100 ml×3). The filtrate and the washed liquid were combined and distilled off to obtaine 34.0 g of crude Diels-Alder adduct was obtained. The crude product was recrystallized from 125 ml of a mixture solvent of heptane-ethyl acetate (5:3) to obtain 27.5 g (110 mmol) of a pure product. Yield: 81%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following:
1 H-NMR: δ1.0-2.2 (m, 4H), 1.1 (s, 3H), 1.2 (s, 3H), 2.8-3.3 (m, 3H), 4.0 (s, 2H), 5.3 (m, 1H), 5.8-6.0 (m, 1H), 6.2-6.4 (m, 1H).
Further, the physical property value is as follows:
Melting point: 114°-115° C.
Step 3
27.5 g (110 mmol) of the Diels-Alder adduct obtained in the above step was dissolved in 420 ml of a mixture solvent of tetrahydrofuran-water (5:2), on ice cooling, 30.0 g (455 mmol) of potassium hydroxide (85%) in 120 ml of water was added, and the mixture was stirred at room temperature for 24 hours. After distilling off tetrahydrofuran, the residue was neutralized with 40 ml of concentrated hydrochloric acid, and the solution was extracted with a mixture solvent of hexane-methylene chloride (98:2) (150 ml×4). The extract was dried over anhydrous magnesium sulfate and filtered, the solvent was distilled off, and 15.7 g of crude 5-norbornene-2-carboxylic acid was obtained. Crude yield: 100%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following:
1 H-NMR: δ1.1-1.6 (m, 3H), 1.7-2.1 (m, 1H), 2.7-3.3 (m, 3H), 6.0 (dd, 1H), 6.2 (dd, 1H), 11.4 (brs, 1H).
Step 4
15.7 g (110 mmol) of crude 5-norbornene-2-carboxylic acid was dissolved in 300 ml of ethanol, 1.55 g of 5% palladium-carbon powder was added, and the mixture was stirred under an atmosphere of hydrogen for 24 hours. After the catalyst was filtered off, the solvent was distilled off, and 14.5 g of crude 2-norbornanecarboxylic acid was obtained. Crude yield: 94%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.1-1.9 (m, 8H), 2.2-2.4 (m, 1H), 2.5-3.0 (m, 2H), 11.0 (brs, 1H).
Step 5
24.1 g (367 mmol) of potassium hydroxide (85%) and 18.9 g (120 mmol) of potassium permanganate were dissolved in 84 ml of water, on ice cooling, 8.36 g (59.6 mmol) of crude 2-norbornane carboxylic acid in 84 ml of petroleum ether was added dropwise. After heating and refluxing for six hours, the mixture was stirred at room temperature for 18 hours. On ice cooling, the reaction mixture was slowly added into 120 ml of 6N sulfuric acid, 60 ml of an aqueous solution of 13.0 g of sodium bisulfite was added to the acid mixture, and the solution was stirred at room temperature for one hour. The solution was extracted with ether (100 ml×4), and the extract was dried over anhydrous magnesium sulfate and filtered. The solvent was distilled off, and 8.34 g of crude 2-hydroxy-2-norbornanecarboxylic acid was obtained. Crude yield: 90%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.0-2.3 (m, 10H), 7.4 (brs, 2H).
Example 8
Production of (-)-exo-3-allyl-2-norbornanone
Step 1
8.25 g (52.8 mmol) of crude 2-hydroxy-2-norbornanecarboxylic acid and 19.5 g (55.7 mmol) of sodium bismuthate (80%) were dissolved in 85 ml of water, 18.0 g (156 mmol) of phospholic acid (85%) was added dropwise, and the mixture was stirred at 40° to 50° C. for eight hours and then at room temperature for 18 hours. The reaction mixture was extracted with ether (100 ml×4), and the extract was washed with successive, saturated sodium bicarbonate solution, water and saturated sodium chloride solution (each 100 ml), and dried over anhydrous magnesium sulfate. After ether was distilled off at atmospheric pressure, and the residue was distilled to obtain 3.09 g (28.1 mmol) of (-)-2-norbornanone. Yield 53%.
The compound was identified by 1 H-NMR chart analysis The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-2.3 (m, 8H), 2.5-2.9 (m, 2H).
Further, the physical property values are as follows:
Boiling point: 174° C.
Specific rotation: -28.5° (c 1.55, CHCl 3 ).
Step 2
To 3.4 ml (6.8 mmol) of a 2M solution of lithium diisopropyl amide in tetrahydrofuran-hexane, 1 ml of a solution of 500 mg (4.54 mmol) of (-)-2-norbornanone in tetrahydrofuran was added dropwise at -40° C., and the mixture was stirred at -20° C. for 10 minutes. Then, 1 ml of a solution of 540 mg (4.46 mmol) of allyl bromide in tetrahydrofuran was added dropwise, the mixture was stirred at -20° C. for 30 minutes, the temperature of the mixture was raised to room temperature, and the mixture was stirred for one hour. On ice cooling, the reaction mixture was poured into 20 ml of 1N hydrochloric acid, and the mixture was extracted with toluene (50 ml×4). The extract was washed with successive, saturated sodium bicarbonate solution, water, saturated sodium chloride (each 50 ml), and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was distilled off to obtain 980 mg of crude 3-allyl-2-norbornanone. The product was purified by distillation, and 550 mg (3.66 mmol) of (-)-exo-3-allyl-2-norbornanone was obtained. Yield: 81%.
The compound was identified by 1 H-NMR chart analysis. The data of 1 H-NMR (CDCl 3 ) are shown in the following.
1 H-NMR: δ1.2-2.8 (m, 11H), 4.9-5.3 (m, 2H), 5.6-6.1 (m, 1H).
Further, the physical property values are as follows:
Boiling point: 70°-73° C./3 mmHg
Specific rotation: -89.1° (c 0.972, CHCl 3 ). | The present invention provides a method for producing optically active 3-substituted-2-norbornanones which are useful as starting materials for several kinds of physiologically active materials, and to their intermediates, optically active 2-hydroxy-2-norbornanecarboxylic acid and to a method for producing these intermediates. | 2 |
RELATED APPLICATIONS
The following related applications are each incorporated by reference herein:
U.S. application Ser. No. 10/308,548 of Hugh S. Njemanze et al., entitled “Modular Agent For Network Security Intrusion Detection System,” filed: Dec. 2, 2002.
U.S. application Ser. No. 10/308,584 of Hugh Njemanze et al., entitled “Method For Aggregating Events To Be Reported By Software Agent,” filed Dec. 2, 2002.
U.S. application Ser. No. 10/821,459 of Kenny Tidwell et al., entitled “Comparing Events From Multiple Network Security Devices,” filed Apr. 9, 2004.
U.S. application Ser. No. 10/975,962 of Debabrata Dash, entitled “Security Event Aggregation At Software Agent,” filed Nov. 27, 2004.
U.S. application Ser. No. 11/070,024 of Hector Aguilar-Macias et al., entitled “Message Parsing In A Network Security System, ” filed Mar. 1, 2005.
TECHNICAL FIELD
The disclosed embodiments relate generally to monitoring of network activity. More particularly, the disclosed embodiments relate to a system and method for merging multiple entries representing related network activity.
BACKGROUND
It is desirable to monitor log entries received from various devices and pieces of software in a network. Frequently, those other devices or pieces of software may create several logging messages for reasons of convenience, speed, or reliability. This is done, for example, so that some information will reach the central point for the event, even if not all information does. For instance, it may be desirable to send a log message before the work is completed to make sure something is recorded even if the system later crashes before completely finishing the work in question.
In addition, certain types of log events occur in the device over time. It is considered desirable to send loggable events as they occur, instead of waiting until all loggable occurrences have happened for an event at a device.
If multiple devices send log entries to one or more central collection points in the network, the log entries for the various events from the various devices will most likely arrive interspersed with each other. The various log entries may not be adjacent in the log. They may be interleaved with very similar events. They may be spread across several log files. The sequence of entries may not be complete (perhaps the sensor crashed before the operation was completed).
What is needed is a way to automatically collect high-level event information from log entries that were generated under the problematic conditions described above.
SUMMARY
Preferred embodiments of the present invention define an agent containing a parser, a grouping tracker module, and a mapping module. The parser separates arriving log entries into tokens. The grouping tracker analyzes these tokens to determine which merged events the tokens belong to (if any). In the described embodiment, the grouping tracker operates in accordance with configurable merge properties, although other embodiments may have these properties hard-coded. The merge properties allow configuration of various properties associated with the act of grouping the log entries into high-level merged events. In the described embodiment, these properties include some or all of: what types of log entries will be considered for each merged event, which IDs are used to identify each merged event, which entries begin and end a merged event, a timeout value that automatically ends collection of entries for an existing merged event, even if no end entry is found.
In the described embodiment, the mapping module receives log entries associated with specific merged events and maps them to fields in the merged event data structure in accordance with mapping properties (although these mapping properties could also be hard-coded).
The described embodiments of the invention use regular expressions in the merge properties to describe values that are searched for in the received log entries. For example, a regular expression may define which entries are part of a multi-entry event, may detect the first entry in a multi-entry event, and may detect the last entry in a multi-entry event. The merge properties also declare which field in the entries must contain the same values in order to be merged (for instance, the entries might both have the same numeric id or mention the same ip address). The described embodiment of the present invention can process log entries for events that are interspersed with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a system in accordance with an embodiment of the present invention.
FIG. 2 is a flowchart of an embodiment of a method performed to process log entries in accordance with merge properties.
FIG. 3 is a flow chart of an embodiment of a method performed to add a log entry to a merged event in accordance with mapping properties.
FIG. 4 is a flow chart showing a oneOf function used in the mapping properties in an embodiment of the present invention.
FIG. 5 shows an example in which multiple merged events are being constructed, as interspersed log entries for the various merged events are received.
FIG. 6 shows an example format of one merged event.
DESCRIPTION OF EMBODIMENTS
Embodiments of the present invention are now described with reference to the figures where like reference numbers indicate identical or functionally similar elements.
FIG. 1 shows a block diagram of a system 100 in accordance with an embodiment of the present invention. System 100 preferably contains an agent 104 in one or more central points in a network. Agent 104 receives log entries from multiple devices and pieces of software over a network, such as the internet, a LAN, WAN, wireless network, mobile network, or any other appropriate mechanism that allows remote devices to send log entries to agent 104 .
Log entries are received by a parser 102 and parsed into tokens in a manner known to persons of ordinary skill in the art. In another embodiment, parsing is performed as described in U.S. application Ser. No. 11/070,024 of Hector Aguilar-Macias et al., entitled “Message Parsing In A Network Security System,” filed Mar. 1, 2005, which is herein incorporated by reference.
The received log entries can be any appropriate format that parser 102 is able to parse. Parser 102 outputs tokens based on the received log entries. These tokens are received by a grouping tracker module 110 .
Grouping tracker module 110 is connected to receive merge properties from a memory or other storage module or device 112 . The merge properties specify how received log entries are to be interpreted as they are used to build merged events. Grouping tracker module outputs log entries that are associated with specific merged events into a mapping module where the log entries are mapped into merged events that are being built up from the received log entries. This mapping occurs in accordance with mapping properties 122 . The output of mapping module 120 is one or more merged events resulting from multiple log entries. The process generally described in FIG. 1 will be described in more detail below in connection with an example.
EXAMPLE
Here is an example of how event merging works in an embodiment of the invention:
Assume the following lines of log entries (these are also sometimes called “messages”):
[18/Jul./2005:12:30:20-0400] conn=8 op=0 msgId=82-BIND uid=admin
[18/Jul./2005:12:30:25-0400] conn=7 op=−1 msgId=−1-LDAP connection from 10.0.20.122 to 10.0.20.12.
[18/Jul./2005:12:30:30-0400] conn=8 op=0 msgId=82-RESULT err=0
Parser 102 parses these received log entries into key-value pairs. For each log entry this yields a set of tokens. For example, the log entry:
[18/Jul./2005:12:30:20-0400]] conn=8 op=0 msgId=82-BIND uid=admin
Yields tokens having the following key/value pairs:
Date=18/Jul./2005 12:30:20
Connection=8
Operation=0
MessageId=82
OperationName=BIND
UserId=admin
Similarly, the other two log entries yield their own key/value pairs:
[18/Jul./2005:12:30:25-0400]] conn=7 op=−1 msgId=−1-LDAP connection from 10.0.20.122 to 10.0.20.12
Date=18/Jul./2005 12:30:25
Connection=7
Operation=1
MessageId=−1
OperationName=LDAP
Source=10.0.20.122
Destination=10.0.20.12
[18/Jul./2005:12:30:30-0400]] conn=8 op=0 msgId=82-RESULT err=0
Date=18/Jul./2005 12:30:30
Connection=8
Operation=0
MessageId=82
OperationName=RESULT
ResultCode=0
FIG. 2 is a flowchart 200 of an embodiment of a method performed to process received log entries in accordance with merge properties 112 . In a preferred embodiment, the method is performed by grouping tracker module 110 . If a timeout 202 is reached for a merged event currently being built, the merged event is ended 204 and control returns to element 202 . Thus, even if no explicit ending log entry is found, a merged event will be closed when its timeout occurs. The timeout value may differ for different types of logging devices and for different merged events from a single device. As described below, the timeout value is contained in the merge properties.
Element 206 receives a next log entry to process. If the log entry is to be considered for merging 208 (as defined in merge properties 112 ), the processing continues, otherwise a single event is sent 209 and processing returns to element 202 .
If the log entry is a beginning log entry for a new merged event 210 (as defined in merge properties 112 ), a new merged event is opened 212 (see FIG. 5 for an example of multiple merged events in the process of being built). In some embodiments, the timeout clock for the merged event is started 212 .
If the log entry is not a beginning log entry, but it contains an ID of an existing merged event currently being built 214 , then an exception is logged and a single event is sent 215 . Otherwise, processing continues and the tokens and log entry are passed 220 to the mapping module so that its information can be added to the merged event. In an embodiment, an ID can be a single field in the log entry or can be multiple fields in the log entry that have common values for all log entries of a merged event.
If the log entry is an end log entry for a new merged event 216 (as defined in merge properties 112 ), an existing merged event is ended and removed 218 from the grouping tracker module (see FIG. 5 for an example of multiple merged events in the process of being built). If a log entry indicates an event end, the corresponding merged event will be ended and removed from the structure of FIG. 5 .
To continue the example, the merge properties 112 in this example are defined as:
merge.count=1
merge[0].pattern.count=1
merge[0].pattern[0].token=OperationName
merge[0].pattern[0].regex=(BIND|RESULT)
merge[0].starts.count=1
merge[0].starts[0].token=OperationName
merge[0].starts[0].regex=BIND
merge[0].ends.count=1
merge[0].ends[0].token=OperationName
merge[0].ends[0].regex=RESULT
merge[0].id.tokens=Connection,Operation,MessageId
merge[0].timeout=60000
First we indicate that we have only 1 merge operation:
merge.count=1
Then we define that we want all the messages with OperationName set to BIND or RESULT to be considered for merging:
merge[0].pattern.count=1
merge[0].pattern[0].token=OperationName
merge[0].pattern[0].regex=(BIND|RESULT)
Now we specify that the messages that have an OperationName set to BIND will start the merge operation:
merge[0].starts.count=1
merge[0].starts[0].token=OperationName
merge[0].starts[0].regex=BIND
And that the merge operation will end once we find a message OperationName set to RESULT:
merge[0].ends.count=1
merge[0].ends[0].token=OperationName
merge[0].ends[0].regex=RESULT
We also need to define how to identify that events belong to the same group, we do that by specifying that the values of Connection, Operation and MessageId must be identical (forming an ID for the merged event):
merge[0].id.tokens=Connection,Operation,MessageId
Finally we define a timeout so that if we do not get the message with OperationName set to RESULT after 60 seconds, then we will send the event as is:
merge[0].timeout=60000
FIG. 3 is a flow chart of an embodiment of a method performed to add a log entry to a merged event in accordance with mapping properties. Received log entries and their tokens have already been identified as being relevant to at least one merged event being built. Mapping module 120 maps information in the log entries to one or more merged events being built (see FIG. 5 for an example of multiple merged events being built. See FIG. 6 for examples of a format for a merged event.)
In this example, mapping properties 122 are defined as:
event.deviceReceiptTime=Date
event.name=_oneOf(mergedevent.name,OperationName)
event.deviceAction=ResultCode
event.destinationUserId=UserId
These properties indicate that we will use the Date as the timestamp for the event, the ResultCode as the device action and the UserId as the destination user id. The name is defined as:
event.name=_oneOf(mergedevent.name,OperationName)
Because this framework also allows you to refer to the “tracking” event that is being used to store the final data. In this case the operation means that either we should use the OperationName or the name of the “tracking” event (if any). For example, the first event will contain the following key-values:
[18/Jul./2005:12:30:20-0400]] conn=8 op=0 msgId=82-BIND uid=admin
Date=18/Jul./2005 12:30:20
Connection=8
Operation=0
MessageId=82
OperationName=BIND
UserId=admin
And a new “tracking” event will be created that will end up with the following mappings:
mergedevent.name=BIND
mergedevent.deviceReceiptTime=18/Jul./2005 12:30:20
mergedevent.destinationUserId=admin
The name of the mergedevent will be BIND because this is a new mergedevent, so mergedevent.name does not exist and the value of OperationName is used (BIND). Now when the second event for the merging group is processed:
[18/Jul./2005:12:30:30-0400]] conn=8 op=0 msgId=82-RESULT err=0
Date=18/Jul./2005 12:30:30
Connection=8
Operation=0
MessageId=82
OperationName=RESULT
ResultCode=0
The merged event will be mapped as follows:
mergedevent.name=BIND
mergedevent.deviceReceiptTime=18/Jul./2005 12:30:30.
mergedevent.destinationUserId=admin
mergedevent.deviceAction=0
Notice that mergedevent.name will be set to BIND because when this event is processed there was already a “tracked” event (mergedevent) with the name set to BIND, so in this case OperationName will NOT be used and the mergedevent keeps the value BIND. Notice how the mergedevent.deviceReceiptTime now was set to 18/Jul./2005 12:30:30 that is because by default the values of mergedevent will be replaced, so deviceReceiptTime will assume the newer value.
FIG. 4 is a flow chart 402 showing the oneOf function 400 used in the mapping properties in an embodiment of the present invention. To process the oneOf function for, for example, an event name, if the event name is currently blank 404 , the current token name is used 406 . If the name is not blank, the non-blank name is retained 408 .
It will be understood that _oneOf is only an example of operations that can be used in the mappings component. The mapping component may contain other “operations” that can make reference to the merged event fields. _oneOf is just an example, in the actual mapping framework Other examples of operations include _concatenate, type conversion operations and others.
FIG. 5 shows an example 500 in which multiple merged events are being constructed, as interspersed log entries for the various merged events are received.
FIG. 6 shows an example format 550 of one merged event. For example, each of the various merged events of FIG. 5 will have this format, although not all the values may be filled in for each merged event. Various implementations of the present invention will contain other examples of merge operations including concatenate, type conversion, counting, and others. Other embodiments include merged event aggregation so that statistics can be kept for numbers of various types of merged events. These aggregated data can be sent to a monitor alone or as part of a combination of other sent data.
The following paragraphs provide a short description of example merge properties 112 included in one embodiment of the invention:
merge.count
Defines the number of merge operations that will be defined.
merge[{mergeindex}].pattern.count
Defines how many patterns will be defined. Merge operations require patterns to define which events will be considered in the merge operation, if no patterns are given then ALL events will be considered.
merge[{mergeindex}].pattern[{patternindex}].token
Defines the token that will be used for this pattern.
merge[{mergeindex}].pattern[{patternindex}].regex
Defines the regular expression to use for this pattern.
merge[{mergeindex}].starts.count
Defines how many start patterns will be defined. Merge operations require start patterns to define which events will start a merge operation, if no patterns are given then ALL events will start a merge operation. Once the operation has been started it can only be ended via a timeout or an end pattern match.
merge[{mergeindex}].starts[{patternindex}].token
Defines the token that will be used for this start pattern.
merge[{mergeindex}].starts[{patternindex}].regex
Defines the regular expression to use for this start pattern.
merge[{mergeindex}].ends.count
Defines how many end patterns will be defined. Merge operations require end patterns to define which events will end the merge operation, if no patterns are given then no event will end a merge operation, the operation will only end via a timeout.
merge[{mergeindex}].ends[{patternindex}].token
Defines the token that will be used for this end pattern.
merge[{mergeindex}].ends[{patternindex}].regex
Defines the regular expression to use for this end pattern.
merge[{mergeindex}].timeout
Defines the timeout in milliseconds for the merging operation. If the timeout is reached then the merge operation will end and the events will be sent. Be aware that these events will be sent via a different thread, so event order is not guaranteed.
merge[{mergeindex}].id.tokens
Defines the list of tokens that will be used to group the events. This property is required.
merge[{mergeindex}].id.delimiter
Defines an optional delimiter to use for the list above, if it is not defined then the delimiter is a comma (,).
merge[{mergeindex}].sendpartialevents
This property is optional and set to false by default. Basically it specifies if each event in the merge operation must be sent individually as it is merged with other events.
merge[{mergeindex}].capacity
This property is optional and set to 1000 by default. An event merging operation requires a cache of events that hold the merged results. This defines how big the cache will be, if the cache overflows then events will be sent as they are and an error will be logged.
Reference in the specification to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Some portions of the above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps (instructions) leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical, magnetic or optical signals capable of being stored, transferred, combined, compared and otherwise manipulated. It is convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. Furthermore, it is also convenient at times, to refer to certain arrangements of steps requiring physical manipulations of physical quantities as modules or code devices, without loss of generality.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or “determining” or the like, refer to the action and processes of a computer system, or similar electronic computing device,.that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Certain aspects of the present invention include process steps and instructions described herein in the form of an algorithm. It should be noted that the process steps and instructions of the present invention can be embodied in software, firmware or hardware, and when embodied in software, can be downloaded to reside on and be operated from different platforms used by a variety of operating systems.
The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, application specific integrated circuits (ASICs), or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. Furthermore, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.
The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any references below to specific languages are provided for disclosure of enablement and best mode of the present invention.
While the invention has been particularly shown and described with reference to a preferred embodiment and several alternate embodiments, it will be understood by persons skilled in the relevant art that various changes in form and details can be made therein without departing from the spirit and scope of the invention.
Finally, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. | A system and method for building merged events from log entries received from multiple devices. Multiple log events generally contribute to a single merged event. In the described embodiment, the mapping module receives log entries associated with specific merged events and maps them to fields in the merged event data structure in accordance with mapping properties. The described embodiments of the invention use regular expressions in the merge properties to describe values that are searched for in the received log entries. A described embodiment of the present invention gives the mapping module access to the event under construction. A new conditional operator, _oneOf, is introduced that selects the first token that is bound to a value out of a list of tokens. | 8 |
BACKGROUND OF THE INVENTION
Conventional gun systems, and particularly such gun systems as are utilized in helicopters, other aircraft and air defense gun systems, where the operator is "in the loop" for at least a portion of the functioning modes of the system, have conventionally not provided for closed-loop aim error correction. In some instances, the operator may be provided with a visual indication of the projected line of flight for the projectile, in a "heads- up display", to enable more accurate manual aiming. However, to date, such aiming systems have not been capable of achieving aim accuracies much less than 10 milliradians.
The search for more accurate gun aiming systems has led to the proposal or development of various closed-loop error correction systems for use in anti-aircraft and other gun systems. Such closed-loop systems have usually been based on the use of radar to track the target and to measure the angle between target centroid and bullet path centroid at the target's range. However, radar closed-loop gun control systems are relatively complex and high in cost, and further, may impose an excessive weight penalty in certain applications. Additionally, radar closed-loop systems cannot be easily adapted to include gunner observations in the fire control sequence. Finally, such systems are particularly deficient when severe ground clutter environments are encountered.
Thus, it is desirable to have a closed-loop gun control system that is relatively light in weight and low in cost. Such a closed-loop system is particularly desirable when it provides an accuracy improvement over the 10 milliradian accuracy available with conventional aiming techniques and which is passive so as not to provide signals that may be utilized by opposing forces to neutralize the gun system.
SUMMARY OF THE INVENTION
An exemplary embodiment of the invention incorporates an optical sight with provision for converting invisible optical radiation to visible signals, observable by the gunner and generating control signals utilizable by the gun control system in applying closed loop differential tracking air correction. In the exemplary embodiment, a helmet-mounted sight incorporating the principles of the invention is utilized in a system including provision for translating helmet movements into signal corresponding to the visual line of sight. However, it is to be understood that the system is equally applicable to fixed and other mobile gun systems, with or without independent gunner targeting. Further, it is to be understood that the detectors described in connection with the gunner's sights may be duplicated on a sight system located on, or in connection with, the gun mount so that the system may alternatively be commanded by the gunner-provided signals, or be directed by the signals from the gun-mounted sight.
The sight system includes a plurality of optical energy detectors. Choice of the optical filtering and detector type for use in the system make the system responsive to several different optical energy wave lengths simultaneously. The detectors are multi-element and are divided into sectors so that the activation of the element in a particular sector on the detector matrix indicates that there exists a pre-determined angular difference between the energy from a selected source and the bore-sight axis of the sight. The bore-sight axis in the gunner-controlled sight corresponds to the visual line of sight. The gunner's field of view includes a pipper display for aiming. The display is focused at infinity. The sight also displays, at infinity, a light signal in a sector of the gunner's sight scene, corresponding to the sector of the detector that sensed invisible radiation.
At least one of the detected bands is sensitive to the spectrum in which muzzle flash and hot body radiation predominates. Other detection bands are responsive to the radiation peaks of the timed and impact flashes of the gun projectile. In addition to wave length discrimination, the signals are processed to discriminate by pulse width. For example, the pulse width of a laser designator is utilized in distinguishing it from the impact flash. Non-pulsating sources such as continuous hot-body radiation as might emanate from an aircraft or land vehicle is passed through a chopper to tranduce the continuous radiation into pulses.
The cooperative ammunition round utilized with the invention includes a timed pyrotechnic flash at a predetermined interval after firing. The timed flash is useful where there is not impact flash as may be the case in airborne targets or where the impact flash is not observable due to terrain.
The impact flash included in the cooperative round is distinguishable from the timed flash by the radiation wave length selected for the two pyrotechnic flashes.
In a typical engagement, the operator acquires the target visually and centers the bore-sight pipper on the target. A typical open-loop gun pointing solution is accomplished and the operator fires the gun. The path of flight of initial rounds is detected from the timed or impact flash. A signal corresponding to the angular error of the impact flash sensor is delivered to the gun fire control computer. The fire control computer commands a corrected aim to compensate for the detected error. The correction reduces the angular error after the initial detected round, for all subsequent rounds, to within 2 milliradians or less for systems with low dead zone and accurate gun pointing. Where the impact flash is not observable, the timed flash is utilized to indicate an angular deviation for the flight path of the round from the visual line of sight to the target. The gun aim is corrected on the basis of this angular error until impact flashes are observed, or the target is destroyed.
Targets may also be acquired by the cooperative radiation emissions emanating from them. For example, the muzzle flash of a firing target may be utilized to locate the target position. The muzzle flash is observable to the gunner through conversion of the radiation which is predominately in the infrared spectrum, to visible radiation from one of the light emitting sources in the invisible-to-visible converter. The observed angular relationship may be utilized by the gunner to center the bore-sight pipper on the location of the target emissions and thereby either visually acquire the target or commence firing at the assumed target location. A similar sequence is utilized in the case of a laser illuminated target. The gun sight system detects the radiation from a target illuminated by friendly forces. The gunner may turn the helmet sight to the indicated location for the laser illuminated target and proceed as described above in the muzzle flash example, or may select the automatic mode whereby the gun mount is automatically turned to eliminate the angular error between the bore-sight and the indicated direction for laser illumination. Reactive gun fire may then proceed until the target is destroyed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the helmet mounted sight.
FIG. 2 is an enlarged sectional view taken on line 2--2 of FIG. 1.
FIG. 2a is a face view of a chopper disc used in FIG. 2.
FIG. 3 is a face view of a multiple element laser/impact flash detector and similar infrared detector.
FIG. 4 is a face view of a timed flash quadrature detector.
FIG. 5 is a face view of the invisible-to-visible converter.
FIG. 6 is a block diagram of a typical system utilizing the sight.
FIG. 7 is a block diagram of the gun sight system.
FIG. 8 is a diagram of a typical use of the sight.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2 of the drawings, there is illustrated a helmet mounted sight 10 including an upper body portion 12 and lower body portion 14. The upper body portion 12 houses and mounts the detectors 18, 22 and 24. Radiant optical energy is focused on these detectors by a lens 15, for example. Lens 15 receives light from the dichroic mirror 34, which diverts a portion of the sight scene to lens 15. A first portion of the energy is reflected by dichroic mirror 16 and dichroic mirror 20 into the impact flash and laser detector 22. The energy passes through bandpass filter 108 to exclude energy in other than the bandwidth of interest, as will be described more fully hereinafter. A secondary portion of the energy passes through dichroic mirror 20 and bandpass filter 110 to the muzzle flash and hot body radiation detector 24. A light chopper 36 is positioned to intercept the energy impinging on detector 24 and is utilized to pulse continuous hot body radiation in a manner to be described more fully hereinafter. A portion of the energy incident on dichroic mirror 16 passes through and is focused upon the timed flash detector 18 through bandpass filter 112. Energy from the invisible-to-visible converter (light display) and pipper 26 is focused at infinity to the observer 53 by lens 28, and reflected on mirrors 30 and 32 and the rear face of mirror 34.
Referring now to FIG. 3, the configuration for the multiple element detectors 22 and 24 is illustrated. The detector configuration 50 is illustrated as being made up of a plurality of quadrants, as exemplified by quadrant 52, around a central quadrature of elements typified by element 51. The four center detectors are quadrature detectors for providing precision tracking. The detectors are multi-element for the purpose of converting the information handled by these detectors into visible information via the invisible-to-visible converter 26. The total detection field of view is divided into sectors. The sector upon which the applicable energy is impinged will signal the invisible-to-visible converter to display a signal to the gunner in that corresponding sector. The central portion of the detector 50 includes processed segments 51 which produce an output signal that varies in intensity in proportion to the displacement from the common center 55. By combining the signals in an amplitude monopulse fashion from the four sectors and normalizing the output to eliminate amplitude variations, a signal which is representative of the angular variation and displacement from the optical center axis is produced for any signal impinging on these sectors 51. This feature is important in providing accurate guidance to the gun aiming system.
Referring now to FIG. 4, the detector 18 is illustrated. Detector 18 is intended to produce a signal in response to the timed flash. Detector 18 is divided into four quadrants 56 processed in the manner previously described for the elements 51 in detector 50. Therefore, detector 18 is capable of providing signals to the gun fire control system which corresponds to the angular error between the line of sight and the location of the projectile at the instant of the timed flash.
Referring now to FIG. 5, the configuration for the invisible-to-visible converter display 26 is illustrated. The display 26 includes a plurality of light emitting diodes (LED) 62 which are spaced at the centroide of the quadrants of corresponding detectors 24 and 22. The central quadrant 64 corresponds to the four inner quadrants 51 in FIG. 3. A bore-sight pipper or aim point is provided by the central LED 60.
Referring now to FIG. 6, the system block diagram for an embodiment of the invention is illustrated. The system incorporates a gunner's sight 10 and a gun-mounted sight 70. These sights are similar excepting that the gun-mounted sight does not include provision for visual display of information. Either sight may provide information to the electronic gun control 74 which commands aim changes to gun system 71. The gunner's sight is illustrated as being directed along a visual line of sight 82 to visually acquired target 91. An exemplary first round is illustrated as passing along trajectory 76 and emitting timed flash 78 and impact flash 80. Impact flash 80 is illustrated as being short of the target. Thus the gunner's sight would sense the impact flash 80 along sight line 84.
The use of the gun mounted sight is illustrated in conjunction with a laser designator 90 which is illuminating target 91. The reflected laser illumination is detected by the gun mounted sight along aim line of sight 86. The first round is detected via the impact flash 80 along flash line of sight 88.
The angular error for either system of aim is converted by the electronic control 74 into aim change commands to produce a subsequent round which is correctly aimed within 2 milliradians, for example.
Referring to FIG. 7, the system block diagram for the entire gun control system is illustrated. The optics 10 provide focused radiation which passes through bandpass filters 112, 108 and 110 to illuminate the detectors 18, 22, and 24, respectively. Filter 112 eliminates wave lengths not in the bandpass between 0.6 and 0.7 microns. This bandpass includes the maximum intensity portion of the radiation in the timed flash. A silicon multi-element detector is utilized for the detector 18, for example, and the monopulse output of the detector, from the four center sectors 51 of the multiple element detector 50 in FIG. 3, is delivered to the timed flash monopulse electronics network 114. Timed flash monopulse electronics network 114 converts the signal into a signal representative of the angular magnitude and orientation for the error.
The light energy incident on filter 108 is limited to the bandpass of approximately 0.81 to 1.07 microns. This bandpass includes the peak strength wave lengths in the impact flash and is also inclusive of the laser radiation wave lengths. Thus, the signal from the silicon (for example) detector 22 may be from either an impact flash or laser. This ambiguity is resolved by virtue of the different pulse length for these two sources of radiation in the impact flash and laser monopulse electronics networks 120 and 122. Since the laser does not include any radiation in the visible wave length, it is delivered to the pulse shaping digital display converter 134 and the signal is regularized and amplified so that it may be delivered to the invisible-to-visible converter display (light display) 26 to to illuminate the appropriate LED.
Radiation in the 3 to 5 micron wave length range is passed by bandpass filter 110 to detector 24 which may be a lead selenide detector, for example. This bandpass includes muzzle flash and hot body radiation. A chopper 124 is utilized to reduce the continuous hot body radiation to pulsed form. Thus the output of detector 24 is a pulsed signal. The pulse width determines whether the information will be processed by electronics network 130 or by network 132. In the case of muzzle flash pulse width, the information is processed and delivered to the logic network 136 by the long wavelength IR monopulse electronics network 130 for eventual display through the invisible-to-visible converter 26. Hot body and monopulse electronics network 132 detects the precise pulse width to determine the angular displacement from center of the hot body radiation. The pulse width varies with the displacement from center, in accordance with the transparent portions 40 of chopper 36 illustrated in FIG. 2a. It is also possible to use the phase relationship between the rotational frequency of the chopper and the phase of the pulsed hot body radiation signal from the detector 24 to resolve the angular orientation of the radiation. Since the primary strength of the radiation may be in the invisible range, this information is also delivered to the pulse shaping digital converter 134 via the logic network 136 for eventual display on the invisible-to- visible converter 26. Logic network 136 establishes a target signature priority of display and input to the fire control computer 140 so that only the most pertinent information is displayed as an illuminated LED in display 26. The logic network 138 sends the impact flash angle data to the fire control computer 140 when that is available, and utilizes the timed flash only when the impact flash is not detected by the detector 22. The output of the logic network 136 is used in conjunction with the output of the timed flash/impact flash network 138 to generate in the fire control computer 140 a differential error signal between the centroid of the target and the centroid of the bullet pattern. In addition, helmet angle data, shown as block 139 in FIG. 7, is fed into the fire control computer 140. Such angle data could be obtained from a pantagraph or servoed gimbal devices in other systems, for example. The result of the foregoing is a closed-loop solution that is not affected by small imperfections in the target tracking. Thus the fire control computer 140 receives information on the relative orientation between the target location and the line of flight of the projectile. This differential angular error between these two positions results in closed-loop gun aim orders to reduce the error for subsequent rounds. Closed-loop corrections are in addition to a standard director fire control system.
The amplitude monopulse electronics networks 114, 120, 122, 130 and 132 are of the type used in radar systems which derive angle-error information on the basis of a single pulse. This radar tracking technique is also called "simultaneous lobing" by those skilled in the art. Conventional digital techniques are used in the logic networks 136 and 138 with such circuits as a read-only memory, NAND gates, etc., which, in effect, form a truth table. As is known, a truth table is a table that describes a logic function by listing all possible conbinations of input values and indicating for each such combination the true output values. The fire control computer 140 is a general purpose digital computer which uses the outputs of the logic networks 136 and 138 for the solution of the fire control equation.
OPERATION
The use of the system of the invention in a typical operational environment is illustrated in FIG. 8. A helicopter gun ship 150 is provided with a gun mounted sight 151 and helmet mounted sight 155. Target 91 is illustrated as being illuminated by a laser designator 90 along illumination path 160. The laser designator is visually aimed by an observer 152 who has visually acquired the target. Communications between the observer and the helicopter gun ship indicate the general vicinity of the target so that the vehicle is turned to bring the target within the optical field of view of this sight. As soon as the laser return along light paths 154 or 156 is detected, the gunner 161 in the helicopter gun ship 150 will be provided with a signal corresponding to the angular error between the line of sight and the target location. The gunner turns his head and/or the turret 173 gimbals to align the optical line of sight with the target location. The gun 175 is then fired resulting in a projectile path 143 and an impact designated by impact flash 80. The impact flash return along line 158 is detected by the gun sight optics 151, and the angular error between the laser return indicating the target location on line 154, and the impact flash return on line 158 is sensed. The angular deviation and orientation of the sensed error results in commands to gun 175 to a new aim orientation. Subsequent rounds are fired and detected until the target is destroyed.
In the exemplary application of a helicopter gun ship, the system of the invention may be employed against enemy gun fire. The invention can be used in conjunction with a prime threat detector or without. A prime threat detector determines the general location of the gun that is firing the bullets coming closest to the aircraft at a particular instant. This information is used by the gunner with his helmet mounted sight, via head movements, to include the opposing fire location within the field of view of the system. The muzzle flashes from the firing gun will be detected at detector 24 and decoded as muzzle flashes by the monopulse muzzle flash electronics network 130. The muzzle flash signal from the network 130, if the muzzle flash is the highest priority target detected, will be coded with a distinguishing repetitive rate and pulse length by the pulse shaping digital display converter 134. From the converter 134 the coded pulses are fed to the invisible-to-visible converter 26, causing the light emitting diode in the corresponding sector of the light display to be illuminated. For example, LED 62 would be illuminated to indicate a muzzle flash in that direction and distance. The light from LED 62 is superimposed on the gunner's sight scene and appears at infinity by the effect of lens 28. Thus the operator is capable of turning the sight to center the pipper 60 on the location of the muzzle flashes. When the muzzle flashes are bore-sighted, an indication will be provided on all four lights 64. The central portions of the detector 51 are providing a proportional signal throughout the aiming process indicating the angular error and orientation for use in the gun control computer and gun aiming system. At this stage, the gunner may elect to commence firing based on the visual line-of-sight, or can turn the system over to the gun-mounted sight, allowing the system to automatically update the aim based on continuing muzzle flashes and upon the angular error as evidenced by impact flashes.
In the case of a cooperative target, that is a target which is either illuminated by a laser designator or a target emitting hot body or muzzle flash radiation, it is not necessary to visually track the target. The aim information is provided by the cooperative radiation, and the aim is updated by commands from the gun fire control computer 140 in response to the angular error. The angular error may be derived from the impact flash, as in air-to-ground engagements, where the location of the impact flash is visible from the aircraft. However, where the impact flash is not visible, due to impact beyond the line of sight, or as in air-to-air engagements, the system logic commands corrective response to the timed flash. The timed flash is set to radiate a 1 millisecond pulse, for example, at a predetermined timed interval from firing such as 1/2 second. The interval is selected to be equivalent to a nominal range or, for example, one half of the effective range of the system. In this manner, it is possible to obtain a rough approximation of range by determining whether or not the timed flash has radiated prior to impact when used against ground targets. Whereas the timed flash is not a precise measurement of angular error at the target distance, due to the trajectory of the projectile, it is a sufficient approximation to close the aim error and eventually result in an impact flash due to target hits or hits in the immediate vicinity of a ground target. | A sight system for providing closed-loop differential tracking control over gun aiming, utilizing visual and non-visual optical radiation to assist the gunner in acquiring and destroying targets as well as providing information to the gun control computer for automatic acquisition and firing. The sight is used in conjunction with a cooperative ammunition round which emits pulsed flashes at a timed interval after firing and upon impact. Portions of these signals are in the non-visible spectrum, and an invisible-to-visible converter is utilized to signal the relative location of the flashes to the gunner. A similar conversion is utilized to provide information on laser designator illumination and other non-visible radiation emanating from the target. | 5 |
CROSS REFERENCE
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/280,348 filed Oct. 25, 2002, currently allowed, which claimed priority based on U.S. Provisional Application Ser. No. 60/343,106 filed Oct. 25, 2001 and entitled “LOAD RESTRAINING DEVICE.”
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to securement of loads and in particular to securement of loads for transport by railcar, and is more particularly directed toward a system for restraining loads in box cars or other transportation vehicles by use of a web strap net and ratchets.
[0004] 2. Description of Related Art
[0005] Loads being transported generally require some type of restraint system in order to prevent damage to both the load and the transportation vehicle. Loads on rail cars need to be restrained from shifting under the various loads imposed by draft, buff, and rocking of the car.
[0006] For particular types of loads, such as large rolls or coils of sheet material, or palletized loads, tensioning mechanisms using straps and anchors are advantageous. When cargoes contained on racks, in boxes or bags, and arranged on pallets or slip-sheets, are loaded into railcars, some form of cargo restraint is required. One presently known form of load restraint is a movable bulkhead or “door” that can be placed in selected positions along the length of a box car. This bulkhead is held in place by locking pins inserted into floor tracks and ceiling tracks. Adjustment of bulkhead position is facilitated by rollers on a ceiling carriage that engages a ceiling rail or track.
[0007] This bulkhead approach has become less popular in recent years due to high maintenance. A bulkhead unit will frequently fail because the unit ceases to roll well, or fails to lock properly. There is also a safety concern, since bulkheads can disengage from the top track and fall, causing injury or death to workers, and damage to railcars and cargoes.
[0008] A form of bulkhead restraint system implemented with web strapping and ratchets has been tried on railcars and highway trailers. In this prior art system, the web connects to a side wall via a wall anchor and hook, extends outwardly at an angle of about 90 degrees to a point on the opposite wall of the car or trailer. This portion of the web is connected to the opposite wall via similar wall anchors and hooks. To provide tension in this “bulkhead web,” ratchets are provided on the netting itself.
[0009] This system has a number of disadvantages, among which are an inherent “cross-car” load distribution that has a tendency to pull car walls in. In addition, the bulkhead web is not easily positioned or adjusted to prevent undesired load shift. Accordingly, a need arises for a load restraining device that is dependable and safe in operation, as well as being economical to install and relatively maintenance-free. The load restraining device should be capable of providing appropriate load tension to prevent load shift, as well as keeping the load centered in the car or trailer to eliminate the need for so-called “center-void” fillers.
SUMMARY OF THE INVENTION
[0010] These needs and others are satisfied by the load restraining device of the present invention, in which the known bulkhead restraint system is replaced by web strap netting and ratchets in a unique arrangement. Briefly stated, the load restraint system of the present invention does not rely on the traditional method of a wall anchor and hook, but instead provides a system in which straps extending from one side of a web strap arrangement initially run parallel to the wall to which they are connected, as opposed to extending perpendicular to the wall as in the prior art. The anchor itself is a horizontal wall member running longitudinally along the wall of the railcar or trailer. An adjustable anchor is used to permit moving the attachment point several inches to allow for load variations. The attachment of the netting is normally 14″ to 18″ behind the face of the load. Unlike previous systems, this provision of anchor points behind the load effectively “encapsulates” the load rather than merely providing a bulkhead. The side of the railcar or trailer that includes these adjustable anchors is termed the “fixed” side and has no ratchets.
[0011] The netting is similar to known web strap netting. It has horizontal and vertical web straps (3″ wide is used but other widths are possible). It features ends on one side that fit into nut bolts in the wall anchor on the fixed side. The net runs behind the load to these anchoring points, and then around the load in front and over the top if needed. The other side of the net runs behind the load and the straps are fed into rings, which allow the strap ends to be fed into ratchets for tightening. The web strap is not normally secured to the ceiling or floor, but such features could be incorporated under unique circumstances.
[0012] The netting of the present invention also features a multitude of vertical straps in positions corresponding to the “corners” of the load (where the netting wraps around the load). This “soft corner protector” provided by this unique web strap geometry is to prevent the horizontal straps from digging into the load at the corners. This soft corner protection feature may also be implemented by providing canvas or other fabric at the sides of the net, about 12″ to 18″ in width, and extending the full height of the net. Preferably, the canvas or fabric would not extend over the full width of the net as in previous designs. There are no ratchets positioned along the netting itself as in previous systems.
[0013] Along the wall opposite the “fixed” anchors is a series of ratchets mounted on the wall horizontally and parallel to the wall. The ratchets may be mounted either permanently or in such a way as to allow easy removal by unscrewing, unbolting or tack weld cutting. Damaged ratchets can thus be removed easily for repair or replacement, if needed.
[0014] The netting is connected to the ratchets by taking the horizontal loose strap ends and feeding them around pins, or through adjustable rings, mounted on a horizontal rail parallel to the wall. The rings or pins are preferably located about 10″ to 18″ behind the load face. This results in the net “encapsulating” the load along the face that abuts the net. The loose ends are then fed into the ratchet and reel bars, and pulled tight to remove any slack, then the ratchet handle is “pumped” to tighten the load to the desired “preload” tension. At unloading, the tension is released, in this case by rotating the ratchet handle 180 degrees. The ratchet is mounted far enough from the load face to permit this operation. Upon unloading and loosening of the net, it is stored on a hanger provided on the same wall as the “fixed” anchors.
[0015] Using a web strap netting that starts behind the load instead of the traditional “straight across” method allows the web strap net to pull the load toward the center of the railcar or trailer to prevent load shift. “Behind the load” securement allows load-shifting forces to be taken down the length of the car instead of across the car. This eliminates the potential to pull car walls in. It also keeps the load centered in the car, and thus eliminates the need for center void fillers.
[0016] An alternative embodiment utilizing multiple restraining net portions and flush-mounted anchors is also described. In accordance with one embodiment of the present invention, a load restraining system adapted for installation in a cargo transportation vehicle comprises a cargo restraining net including horizontal and vertical strap elements attached at their intersections, and an extension portion proximate an upper edge, the extension portion adapted to engage with one or more corners of a cargo being restrained, a plurality of anchors affixed to a first sidewall of the transportation vehicle, a plurality of strap adjustment mechanisms affixed to an opposing sidewall of the transportation vehicle, a first plurality of web straps extending from a first side of the cargo restraining net and affixed to the plurality of anchors, and a second plurality of web straps extending from a second side of the cargo restraining net and engaged with the plurality of strap adjustment mechanisms. The cargo restraining net firmly restrains the cargo when the strap adjustment mechanisms apply tension to the web straps, each of the first and second plurality of web straps extending from the cargo restraining net to the anchors and strap adjustment mechanisms is substantially parallel to the first and second sidewalls of the transportation vehicle, and the extension portion of the cargo restraining net engages the corners of the cargo to prevent horizontal strap damage to cargo corners.
[0017] In accordance with an alternative embodiment of the invention, a removable load restraining system adapted for installation in a cargo transportation vehicle comprises first and second cargo restraining net portions including horizontal and vertical strap elements attached at their intersections, a plurality of anchors substantially flush-mounted to interior sidewalls of the transportation vehicle, web straps extending from a first side of the first cargo restraining net portion and from a second side of the second cargo restraining net portion, the web straps removably engaged with the plurality of anchors, a plurality of strap adjustment mechanisms affixed proximate a first side of the second cargo restraining net portion, and a plurality of web straps extending from a second side of the first cargo restraining net portion and removably engaged with the plurality of strap adjustment mechanisms. The cargo restraining net portions meet along the cargo load face and firmly restrain the cargo when the strap adjustment mechanisms apply tension to the web straps, and each of the web straps extending from the first side of the first cargo restraining net portion and from the second side of the second cargo restraining net portion, in removable engagement with the plurality of anchors, is substantially parallel to the first and second sidewalls of the transportation vehicle.
[0018] In yet another alternate embodiment, web strap netting is used without ratchets. In accordance with this embodiment, a load restraining system for installation in a transportation vehicle comprises a plurality of cargo restraining straps to engage the face of the cargo being restrained, attached to a plurality of anchors affixed to the sidewalls of the vehicle. The web strap netting having a loop at each end of horizontal web strap elements that engage with an anchor fastener securing it to the anchor. The web strap is attached behind the face of the load so that the strap runs along the sidewall of the vehicle before engaging the face of the load.
[0019] Further objects, features, and advantages of the present invention will become apparent from the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a partial plan view of a railroad box car interior;
[0021] FIG. 2 is a section view of the box car of FIG. 1 , along section lines 2 - 2 ;
[0022] FIG. 3 is an elevational view of a portion of the interior wall of the box car of FIG. 1 ;
[0023] FIG. 4 is a top view of the wall portion of FIG. 3 ;
[0024] FIG. 5 is an elevational view of another portion of the interior wall of the box car of FIG. 1 ;
[0025] FIG. 6 is a top view of the wall portion of FIG. 5 ;
[0026] FIG. 7 is an enlarged view of a hanger assembly provided on an interior wall of the box car of FIG. 1 ;
[0027] FIG. 8 is a partial plan view of the box car of FIG. 1 , illustrating load restraining devices in accordance with the present invention;
[0028] FIG. 9 is a partial section view of the box car of FIG. 8 along section lines 9 - 9 ;
[0029] FIG. 10 is a partial section view of the box car of FIG. 8 , along section lines 10 - 10 ;
[0030] FIG. 11 is an elevational view of a wall anchor in accordance with the present invention;
[0031] FIG. 12 is a plan view of the wall anchor of FIG. 11 ;
[0032] FIG. 13 is an end view of the anchor of FIG. 11 ;
[0033] FIG. 14 is a plan view of a ratchet anchor in accordance with the present invention;
[0034] FIG. 15 is an elevational view of the ratchet anchor of FIG. 14 ;
[0035] FIG. 16 is a section view of the ratchet anchor of FIG. 15 along section lines 16 - 16 ;
[0036] FIG. 17 illustrates web strap netting prior to the final fabrication step;
[0037] FIG. 18 depicts the web strap netting of FIG. 17 in its final form;
[0038] FIG. 19 is an elevational view of a hanger;
[0039] FIG. 20 is an end view of the hanger of FIG. 19 ;
[0040] FIG. 21 is a top view of the hanger of FIG. 19 ;
[0041] FIG. 22 is an expanded view of a portion of the interior of the box car of FIG. 8 , illustrating operation of a load restraining device in accordance with the present invention;
[0042] FIG. 23 illustrates an alternative embodiment of web strap netting prior to the final fabrication step;
[0043] FIG. 24 depicts the web strap netting of FIG. 23 in its final form;
[0044] FIG. 25 is a top plan view of a complete ratchet assembly;
[0045] FIG. 26 is a side elevational view of the ratchet assembly of FIG. 25 ;
[0046] FIG. 27 illustrates an alternative web strap arrangement in accordance with the present invention;
[0047] FIG. 28 shows an alternative web strap arrangement designed to interconnect with the web strap of FIG. 27 ;
[0048] FIG. 29 depicts yet another alternative web strap arrangement in accordance with the present invention;
[0049] FIG. 30 is a perspective, partially cut-away view of a railcar illustrating anchor placement;
[0050] FIG. 31 is a top plan view of a web strap in engagement with an anchor; and
[0051] FIG. 32 is a side elevational view of the web strap and anchor of FIG. 31 .
[0052] FIG. 33 is a perspective view of an alternate embodiment of the load restraining device without ratchet assemblies that is fixed at one end of a load.
[0053] FIG. 34 is a perspective view of an alternate embodiment of the load restraining device without ratchet assemblies that is adjustable at one end of a load.
[0054] FIG. 35 is a perspective view of an anchor channel and fulcrum bolt of the embodiment of FIG. 33 .
[0055] FIG. 36 is a perspective view of an anchor channel and anchor bolt of the embodiment of FIG. 33 .
[0056] FIG. 37 is an exploded perspective view of the embodiment of FIG. 33 .
[0057] FIG. 38 is an elevation view of yet another alternative web strap arrangement in accordance with the present invention.
[0058] FIG. 39 is a detail of a loop at the end of a web strap of the embodiment of FIG. 38 .
[0059] FIG. 40 is a perspective view of yet another alternate embodiment of the present invention depicting the fixed portion of the load restraining device.
[0060] FIG. 41 is a perspective view of the adjustable portion of the load restraining device of FIG. 40 .
[0061] FIG. 42 is a perspective view showing an alternative embodiment of a fulcrum fastener of the load restraining device of FIGS. 40 and 41 .
[0062] FIG. 43 is a perspective view of an alternate embodiment of an anchor channel and anchor pin assembly of the embodiments of FIGS. 40 and 41 .
[0063] FIG. 44 is a plan view of the embodiment of FIGS. 40 and 41 showing the side of a vehicle to which a load has shifted.
[0064] FIG. 45 is a plan view of the embodiment of FIGS. 40 and 41 showing the side of a vehicle away from which a load has shifted.
DETAILED DESCRIPTION
[0065] While the disclosure is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and have herein been described in detail. It should be understood, however, that there is no intent to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as expressed by the following numbered features and elements.
[0066] FIG. 1 is a partial plan view of the interior portion of a railroad box car 100 that illustrates in detail the anchoring system for the load restraining device of the present invention. Of course, the instant load restraining device is equally useful in a trailer of the type generally used for over-the-road transport, and may have applications in other types of carriage, so it should be understood that the railroad box car installation is set forth as an exemplary embodiment, and is not intended to limit the scope of the invention in any way.
[0067] The railroad box car 100 includes vertical members 102 that provide structural integrity for the side wall of the car. The vertical members 102 are substantially equally spaced along each of the opposing railcar sidewalls, and may be formed from wood, steel, or aluminum, for example. Generally, interior walls 101 for the railcar 100 are constructed from plywood sheets that are attached to the vertical supports by conventional means, such as nails, screws, or other known fasteners. The railroad box car 100 also includes doors 106 located approximately centrally along each sidewall. Of course, the presence of doors 106 and their locations have no particular impact on the present invention.
[0068] The anchoring system has been devised such that there are four “fixed side” anchors 103 and four “ratchet side” anchors 104 for each load restraining device installation. There are four such load restraining devices contemplated for the standard railroad box car installation, but there could be more or fewer depending upon the specific application, and the type of transport vehicle into which the devices are installed. For the box car application, there are preferably two retraining devices installed on each side of the railcar lateral centerline (labeled A in FIG. 1 ).
[0069] FIG. 2 is a section view of the box car 100 of FIG. 1 , along section lines 2 - 2 . FIG. 2 provides an indication of the preferred vertical separation of the anchors. As can be appreciated from an examination of FIG. 2 , the anchors are installed such that the lowest anchor position is about 14″ above the floor of the box car 100 , with the next anchor about 40″ above the floor, the third about 66″ above the floor, and the topmost anchor about 92″ above the floor (i.e., the anchors are 26″ apart). Of course, these spacings are designed for a particular type of load, specifically salt containers that measure about 40″×48″×33″ and are arranged in groupings of six, stacked three high by two across. Other vertical spacings of the anchor assemblies 103 , 104 may be more suitable for other types of loads.
[0070] Hangers 201 (shown in a closer view in FIG. 7 ), for easy storage of the restraining devices, are provided on the railcar doors 106 . Of course, the hangers 201 may be positioned in other convenient locations within the transportation vehicle as well. FIGS. 19-21 illustrate a suitable configuration for the hangers 201 . A pair of steel hanger plates 2101 , preferably from ⅛″ stock and curved outward slightly at one end, are attached (such as by welding, for example) to a transverse steel retainer plate 2102 . Holes 2103 are provided through the hanger plates 2101 and retainer plate 2102 for attachment to a door or interior wall of a transportation vehicle.
[0071] FIGS. 3 through 6 illustrate how the anchor assemblies 103 , 104 are mounted. On the fixed side ( FIGS. 5 and 6 ), a single anchor 103 is mounted between the vertical members 102 of the railcar. It is acknowledged that at least a portion of the interior wall material 101 ( FIG. 1 ) may have to be removed to facilitate installation. The anchor 103 may be bolted or bracketed to the vertical members 102 , or even tack welded if the vertical member 102 is formed from steel or other suitable material to facilitate a welding installation. On the ratchet side ( FIGS. 3 and 4 ), the anchor assemblies 104 are of two-part construction. The first part of the ratchet side anchor 104 is the same as the fixed side anchor 103 . Adjacent to this first anchor 103 , a second anchor, comprising a ratchet support assembly 105 , is disposed between the next set of vertical support members 102 . Construction of both types of anchors is described below.
[0072] Each of the fixed side anchors 103 , illustrated in FIGS. 11-13 , is preferably formed from steel channel stock, C4X5.4 (ASTM A36), although the anchors 103 could be made from other suitable materials of similar strength and structural integrity. Each of the anchors 103 is preferably cut to a length of about 42″ for interposition between the vertical support members 102 of the railcar or trailer in which they are installed. Of course, custom length dimensions may be indicated for specific kinds of installations. In their preferred form, sets of eight holes 1101 are provided along the length of the anchor 103 . The holes 1101 are designed to accommodate bolts (ø¾, 10×6, grade 8, preferably, although not shown in the drawings) to secure the web strap netting 801 at the fixed end. One of the holes 1101 in each set may be threaded to accommodate a threaded bolt for greater security, although this would not always be necessary. This aspect of the present invention will be discussed in detail in a subsequent paragraph.
[0073] As mentioned previously, the “ratchet side” requires one of the fixed side anchors 103 and a ratchet support assembly 105 , which is depicted in detail in FIGS. 14-16 . The ratchet support assembly is preferably formed from a length of steel channel stock 1401 of the same specifications as that of the fixed anchor 103 , and cut to the same length. A pair of ratchet support brackets 1402 is affixed to the front face of the channel 1401 , and provided with holes 1404 therethrough for attachment of the ratchet itself (not illustrated in the figure). A support plate 1403 is also affixed to the channel 1401 adjacent to the brackets 1402 . Attachment of the brackets 1402 and plate 1403 may be accomplished by welding or other suitable means.
[0074] FIGS. 25 and 26 illustrate the way in which the ratchet 2202 is mounted on the ratchet support assembly 105 . A securing bracket 2502 is engaged behind support plate 1403 , and a ratchet locating and securing bolt 2501 is then passed through the ratchet support bracket 1402 (and also through securement holes provided on the ratchet 2202 ), and a tack weld 2505 is formed to hold the ratchet 2202 in place.
[0075] FIGS. 8-10 illustrate load restraining devices in operation. As can be appreciated from an examination of the figures, the anchor assemblies 103 , 104 are used to bring a web strap net 801 to bear upon the face 803 of the load 802 . As discussed above, the configuration illustrated is particularly advantageous when employed with a packaged salt load 802 that is arranged in layers of six packages that are stacked three high. It will become clear in light of the subsequent description of operation how the web strap net 801 provides effective load restraint, that applies a restraining force away from the car centerline A, while avoiding a cross-car load that may tend to bow the car sidewalls inward.
[0076] The configuration of the web strap net 801 itself is shown in FIG. 17 . Preferably, the net 801 is constructed from polyester web straps of varying lengths and widths that are sewn together at their intersections as illustrated. In its preferred form, the web strap net 801 is based around four horizontal straps 1706 that are about 206″ long and 3″ wide. Approximately 18″ from one end (the “fixed” end) of these horizontally arranged straps 1706 , a 12″ wide section of web strap 1709 is sewn to the horizontal straps 1706 such that the horizontal straps 1706 are spaced apart by about 26 inches. This vertical strap 1709 is allowed to overlap the uppermost horizontal strap 1706 by about 13″ for a reason that will become clear in the subsequent section.
[0077] A second vertical 12″ strap 1705 is laterally spaced from the first vertical strap 1709 by about 96 inches, and is also arranged to overlap the uppermost horizontal strap. The interior portion of the web strap net is comprised of a series of vertical straps 1701 , approximately 2″ wide and spaced about 14″ apart, in conjunction with a similar arrangement of horizontal 2″ straps 1704 , spaced apart at the same distance. The vertical straps 1701 are also allowed to extend beyond the topmost horizontal strap 1706 by about 13 inches, and an additional 3″ strap 1707 is sewn to the ends of these vertical straps 1701 and allowed to overlap on the ends by about 12 inches.
[0078] As shown in FIG. 18 , the short extensions of the horizontal strap 1707 are folded over and sewn to the uppermost of the long horizontal straps 1706 . This operation creates a region 1801 in the finished net 801 that includes a multitude of vertical strap sections secured to the upper strap 1706 by short oblique strap sections 1802 , 1803 . This folded over section 1801 provides a network of vertical straps that settle over the upper edge and upper corners of a load 802 , serving as corner protectors that forestall the tendency of the horizontal straps 1706 to “dig” into load corners.
[0079] The horizontal straps 1706 include short extensions 1702 that extend beyond the first vertical strap 1709 by about 18 inches, and are terminated in loops or eyes 1708 that are formed by folding over the strap material 1702 and sewing the material together in the “sewing area” illustrated in FIG. 17 . The opposing ends 1703 of the horizontal straps 1706 extend beyond the nearest vertical strap 1705 by about 92 inches. These longer extensions 1703 are intended to interconnect with the ratchet anchor assemblies 104 provided on the side of the transport vehicle opposite the fixed side.
[0080] In an alternative form, the strap ends 1702 can also be equipped with steel rings 2301 , as shown in FIGS. 23 and 24 . The steel rings 2301 are securely sewn onto the straps, preferably by folding the strap around the ring and sewing it securely. Of course, the rings 2301 could also be fastened to the straps by other, equally secure, methods.
[0081] FIG. 22 illustrates the load restraining device of the present invention in operation. Each of the shorter web straps 1702 (terminating in loops 1708 , or rings 2301 , for example) is attached to its corresponding fixed anchor 103 by passing a bolt 2201 through the loop 1708 or ring 2301 and attaching the bolt to the anchor 103 . It should be noted that the net 801 is then led around the face 803 of the load 802 , and the strap extensions 1703 on the opposite side of the net 801 are led around bolts 2201 suitably positioned in anchor assemblies 103 on the opposing wall. These straps 1703 are then led into ratchets 2202 mounted on the ratchet support assemblies 105 . The straps are tightened to apply a restraining force to the load face 803 away from the lateral centerline of the box car in which the load is being transported. The bolts 2201 are positioned “behind” the load face 803 (on the side opposite the car centerline for box car installations). The straps 1703 are disposed parallel to the interior walls 101 of the railcar 100 , thus ensuring that the restraining force applied to the load 802 will not induce a cross-car load that could bow the railcar walls inward.
[0082] In operation (referring also to FIGS. 25 and 26 ), the straps 1703 are fed through the reel bars 2503 of the ratchets 2202 in order to eliminate slack. The handle of the ratchet 2202 is then operated back and forth until the webbing is properly tensioned. Preferably, the reel bars 2503 have at least two wraps of webbing to help ensure that no slippage occurs. To release tension on the webbing, a pawl provided on the handle is pulled back, and the handle is rotated over center to the full open position.
[0083] Of course, the use of the load restraining device is not limited to railcar applications. The inventive system is readily adaptable to over-the-road trailers, even those where cargoes are loaded and unloaded through a single rear door. In those applications, the bolts 2201 are disposed on the side of the load face 803 that is away from the rear door of the trailer. Thus, the load restraining device will forestall undesirable shifting of cargoes toward the loading door in such over-the-road trailer installations.
[0084] Of course, there are situations in which the permanent mounting of ratchet assemblies to the interior sidewalls of transport vehicles (such as railcars) cannot be tolerated. This is true, for example, for multiple use railroad boxcars that may carry various types of loads. Permanently installed ratchets would protrude into the cargo space and could cause damage to some types of cargoes, as well as interfering with the loading of certain cargoes that actually require the entire boxcar width for proper accommodation.
[0085] FIG. 27 depicts a web strap net that forms a portion of a completely removable restraint system that satisfies the constraints introduced above. The web strap net of FIG. 27 features a pair of horizontally disposed 4-inch polyester web straps 2701 , with ratchet assemblies 2704 affixed to first ends thereof. 12-inch wide vertical web straps 2705 are secured to the horizontal straps 2701 . Because this alternative restraint system is designed to be removable, each of the components is constructed so as to be relatively light in weight. Consequently, the web strap net of FIG. 27 is preferably only about 80 inches long. At the strap ends 2702 opposite the ratchet assembles 2704 , securement pins 2703 , preferably of steel construction, are affixed within a tapered end of the web strap so that the ends of the pins 2703 protrude. Preferably, the pins 2703 are installed by looping the fabric of the strap 2701 around the pin 2703 and sewing securely, although other methods of securing the pins 2703 in position may also be devised.
[0086] As noted, because this alternative restraint system is designed to be removable, the web strap nets themselves are provided in sections. The large nets described above in conjunction with the previous embodiment would simply be too heavy, once encumbered with ratchet assemblies, to function satisfactorily in a removable environment. Consequently, the web strap net configuration illustrated in FIG. 28 is designed to mate with the net of FIG. 27 .
[0087] Since the web strap net of FIG. 28 does not include ratchets (these are provided on the mating structure of FIG. 27 ), this particular web strap net of FIG. 28 is intended to be the longer of the two removable sections. Preferably, the web strap net of FIG. 28 is about fourteen feet in length. The web straps 2801 are preferably formed from 4-inch polyester material. 12-inch wide vertical strap sections 2803 are secured to the horizontal straps 2801 . At first ends of the straps 2801 , securement pins 2703 are attached to the straps 2801 in much the same fashion described in conjunction with FIG. 27 . The anchor mechanism used with the securement pins 2703 will be described in more detail below.
[0088] The vertical strap sections 2803 are positioned relatively close to the securement pin 2703 ends of the straps 2801 . The wide vertical straps 2803 are employed because of uncertainty regarding the precise corner locations for various cargoes, and it is believed that this structure provides a wide range of corner support to meet most eventualities. A relatively long run of free strap ends 2802 is designed to extend along the cargo frontage and mate with the ratchet assemblies 2704 of the mating web strap section. Since the ratchet assembles 2704 and the free strap ends will mate and engage with each other at a point along the frontage (or face) of the cargo, it is contemplated that a cushioning material, such as cardboard dunnage sheets, for example, will be inserted between the ratchets and the load face in order to avoid damage to the cargo.
[0089] Alternative web strap net configurations are also provided. FIG. 29 illustrates a web strap net having three horizontal 4-inch polyester web straps 2901 , unequally spaced at 21 inches and 23 inches apart. Of course, many different spacings may be selected without diminishing the effectiveness of the present restraint system. The web strap net of FIG. 29 includes a plurality of 12-inch wide vertical web straps 2902 secured to the horizontal straps 2901 . At first ends of the web straps 2901 , ratchet assemblies 2704 are provided, while at the strap ends opposite from the ratchets 2704 , securement pins 2703 are provided in the manner described above. A three-strap net configuration similar to the net of FIG. 28 (except with three horizontal straps arranged in the same vertical spacing as those of FIG. 29 ) is contemplated, but is not illustrated in a drawing figure. It is believed that utilizing more that three horizontal straps in a web strap net, particularly for the section having ratchet assemblies, renders the net too heavy for easy removability.
[0090] FIG. 30 depicts a railroad boxcar 3000 in a perspective, cut-away view that permits the flush-mounted wall anchors 3001 to be seen on the interior walls of the railcar. Construction and operation of these flush mounted anchors is described in detail in U.S. Pat. No. 6,422,794, issued Jul. 23, 2002, and fully incorporated by reference thereto as if fully set forth herein.
[0091] FIGS. 31 and 32 depict a web strap 2801 of a web strap net secured to the anchor 3001 . It can be appreciated that the securement pin 2701 holds the web strap in the anchor 3001 , and clip member 3101 prevents the securement pin 2701 from rotating and slipping through the anchor 3001 . Of course, the anchor shown is intended to be exemplary, and other flush-mounted anchor systems that firmly secure the web strap nets in position while permitting easy removability may function adequately in the restraint system described.
[0092] Using the web strap nets described above, removable restraint configurations can be easily achieved featuring various combinations of horizontal straps to accommodate a variety of loads. For example, using the plurality of anchors provided in the railcar of FIG. 30 , one could devise a removable restraint system in which a pair of lower web strap nets having three horizontal straps each, combined with a pair of upper web strap nets having a pair of horizontal straps each, provides a total of 5 horizontal straps across the cargo being secured, but is still easily removable, and is relatively light in weight because it is provided in four sections. Other configurations of horizontal straps, such as single 2- or 3-strap nets, or a six-strap net comprised of two pairs of three-strap nets, are easily installed and removed after use utilizing the restraint system of the present invention.
[0093] FIGS. 33 through 39 show another embodiment of the load restraining device of the present invention. This embodiment has two nets, a fixed net and an adjustable net, located at either end of a load within railcar 100 . This embodiment is similar to that previously described except that there are no ratchets. Without ratchet assemblies, anchor assemblies similar to the fixed side anchor assemblies 103 , described above, are attached to both sides of the car.
[0094] FIG. 33 depicts a fixed end net assembly 3300 . The fixed net assembly is comprised of a web strap net 3800 , as shown in FIG. 38 , having a plurality of horizontal web straps 3802 and vertical straps 3804 fixed to a plurality of anchor assemblies 3320 . Each anchor assembly 3320 comprising a channel section 3322 made of steel or other suitable material having a top flange 3324 and a bottom flange 3326 . A plurality of holes 3328 are provided in each of the top and bottom flanges. The holes in the top and bottom flanges are substantially aligned to receive a bolt or other fastener therethrough. Each anchor assembly has an anchor bolt 3330 and a fulcrum bolt 3332 the functions of which are described below. The anchor bolt and the fulcrum bolt are each threadedly engaged and secured by a hex nut 3334 .
[0095] FIG. 34 depicts an “adjustable end” net assembly 3400 . The adjustable net assembly is essentially the same as the fixed net assembly except that the anchor assemblies 3420 are longer than anchor assemblies 3320 to allow for positioning the web strap net at a range of positions. Each anchor assembly 3420 comprising a channel section 3422 made of steel or other suitable material having a top flange 3424 and a bottom flange 3426 . A plurality of holes 3428 are provided in each of the top and bottom flanges. The holes in the top and bottom flanges are substantially aligned to receive a bolt or other fastener therethrough. Each anchor assembly has an anchor bolt 3430 and a fulcrum bolt 3432 the functions of which are described below. The anchor bolt and the fulcrum bolt are each threadedly engaged and secured by a hex nut 3334 .
[0096] FIG. 35 is a detail of anchor assembly 3320 showing fulcrum bolt 3332 , although the arrangement is typical of anchor assembly 3420 and fulcrum bolt 3432 as well. As can be seen extended portion 3806 of the horizontal web strap wraps around fulcrum bolt 3332 running substantially parallel to the sidewall of the vehicle within the channel 3322 . Fulcrum bolt 3332 is threadedly engaged and secured by a hex nut 3334 within a pair of holes 3328 in anchor assembly 3320 .
[0097] FIG. 36 is a detail of anchor assembly 3420 showing anchor bolt 3430 , although the arrangement is typical for anchor assembly 3320 and anchor bolt 3330 as well. Extended portion 3806 runs substantially parallel to the vehicle sidewall within channel 3422 . A loop 3808 on the end of the extended portion 3806 of the horizontal web strap element 3802 is positioned between a pair of holes in channel 3422 . An anchor bolt passed through the pair of holes 3428 and through the loop 3808 of the web strap. A hex nut 3434 threadedly engages anchor bolt 3430 securing the anchor bolt and the web strap to the anchor assembly.
[0098] FIG. 37 is an exploded view showing the fixed end anchor assemblies and net of FIG. 33 showing the web strap net 3800 in cooperation with anchor assemblies 3300 . The arrangement for the adjustable end restraining system of FIG. 34 (not shown) is similar. At the fixed end the anchor assembly channels 3320 are 49″ long with four attached to each side of the car. The extended strap ends 3806 of the net are run between the anchor channel and the fulcrum bolt 3314 . The fulcrum bolt is secured to the anchor channel 3320 by a hex nut 3334 . The loop 3808 on each strap is secured to the anchor assembly by an anchor bolt 3330 which is placed through the loop and fastened with a hex nut 3334 or other suitable fastener.
[0099] Anchor assemblies 3330 , 3430 comprise a channel, preferably made of 4⅝″×2 ⅝″× 5/16″ steel, though other materials may also be suitable. Each channel has a number of holes 3328 , 3428 sized to accommodate a 1″-8×6″ hex bolt. Preferably, the holes are 1 1/16″ dia. spaced on 6″ centers.
[0100] A web strap net is secured to the anchor assemblies. As shown in FIG. 38 , the web strap net 3800 is configured with a plurality of horizontal web straps 3802 and vertical web straps 3804 . The horizontal straps 3802 are made of 4″ wide woven nylon, polyester, or other suitable material, and are joined by sewing or other suitable means to 8″ wide vertical web straps 3804 . Each horizontal strap has an extended portion 3806 located outside of the vertical straps 3804 extending outside the vertical straps 3804 for approximately 34″. The vertical straps act as corners to secure cargo, in this case racks. Generally, a larger number of straps is required the greater the load being restrained. For example, a web strap net having four horizontal straps is designed for a load of 96,000 pounds. Seven horizontal straps could handle a load of up to 168,000 pounds, while eight horizontal straps would be sufficient for a load of 186,000 pounds. As should be apparent, the web strap net may be configured to have any number of vertical or horizontal straps. Additionally, a plurality of web straps may be used in a horizontal configuration without vertical straps.
[0101] At the end of each horizontal strap extended portion 3806 is a loop 3808 . As can be seen in FIG. 39 , the loop 3808 is formed by folding the end of strap 3802 back and securing it to itself by stitching or other suitable means. The loop 3808 is secured to the anchor 3320 , 3420 by an anchor bolt 3330 , 3430 and a hex nut 3334 , 3434 .
[0102] In the embodiment shown, the anchor channels 3320 and 3420 are arranged four-high and are located with the first anchor being 12″ above the floor of the box car 100 , with the second anchor 54″ above the floor, the third anchor 96″ above the floor, and the fourth anchor 138″ above the floor. In other words, in this embodiment, the anchor assemblies 3320 and 3420 are spaced 42″ apart vertically. These spacings are designed for a particular type of load, specifically a three-high stack of auto parts racks each measuring 96″×48″×60″. Other vertical spacings of the anchor assemblies may be more suitable for different types of loads. Also, it should be noted that for arrangements having a different number of horizontal web straps, different numbers of anchor assemblies may be arranged at heights appropriate for the particular application.
[0103] At the adjustable end, the anchor channels 3420 are 193″ long. Holes 3428 are provided 6½″ from each end of the channel and spaced along the channel 6″ apart. Similar to the fixed end, each strap on the net is run between the channel and the fulcrum bolt and secured by an anchor bolt and hex nut. In this way, the attachment points for the net are positioned behind the face of the load at each end. If the load shifts in transit, the fulcrum bolt redirects the force of the shifting load along the length of the anchor channel, and reduces inward pull of the car walls.
[0104] The embodiment of FIGS. 33 and 34 , is used to retain racks containing auto parts. The racks measure 96″×48″×60″ and are stacked three-high. In this case, the anchor assemblies 103 are 193″ long. The anchor assemblies have a plurality of 1 1/16″ diameter holes starting 6½″ from each end and spaced at 6″ centers to allow for positioning the web strap net based on the number of racks to be loaded into the railcar.
[0105] FIG. 40 through FIG. 45 show another alternate embodiment of the present invention. In this embodiment, pins are used instead of bolts for the anchor fastener and the fulcrum fastener. A fulcrum pin 4032 is positioned within a pair of holes in the anchor channel 4020 and retained by a cotter pin (not shown). A link 4052 defining an aperture is attached to a sleeve 4050 . The fulcrum pin in inserted through a hole in the anchor channel 4020 , through the sleeve 4050 , and through the opposite hole in the channel. The fulcrum pin is secured by a cotter pin (not shown) allowing the sleeve 4050 with link 4052 to rotate about the fulcrum pin.
[0106] As shown in FIG. 42 , the web strap 3806 is fed through the aperture in the link 4052 of the fulcrum assembly. The web strap 3806 is secured by an anchor pin 4030 positioned through a pair of holes 4028 in the anchor channel 4020 and through the loop 3808 in the strap and fastened with a cotter pin (not shown). This arrangement provides the benefit of some play in the straps for when a load shifts in transit.
[0107] As shown in FIG. 44 and FIG. 45 , when a load 802 shifts away from one sidewall of railcar 100 , the load 802 pulls web strap 3802 causing link 4052 and sleeve 4050 to rotate about fulcrum pin 4032 away from anchor channel 4020 as shown in FIG. 45 . On the side of the railcar 100 to which the load has shifted, the link 4052 and sleeve 4052 rotate about fulcrum pin 4032 towards the anchor channel 4020 . As load 802 shifts from side to side during transit, the sleeves and links rotatably connected to the fulcrum pins rotate back and forth maintaining contact between the face of the load and the web strap without transferring the lateral load to the car side.
[0108] The load restraining device of FIGS. 33 through 45 is mounted in a transportation vehicle, for example a railcar, with a door located in the side wall of the car. A fixed end web strap net assembly 3300 is positioned at one end of the rail car. An adjustable end web strap net assembly 3400 is positioned at the opposite end of the railcar based on the calculated length of the cargo to be loaded into the car. Markings may be provided on the interior wall of the railcar to assist in positioning the adjustable assembly 3400 . Cargo is loaded through the door in the side of the railcar towards one of the ends of the car, then to the opposite end. Once both ends of the car have been loaded, the final piece of cargo is loaded between the cargo already loaded in either end of the car packing the cargo between the fixed assembly and the adjustable assembly to secure the load.
[0109] There has been described herein a load restraining device that offers distinct advantages when compared with the prior art. It will be apparent to those skilled in the art that modifications may be made without departing from the spirit and scope of the invention. For example, the illustration and description of the present invention in a railcar installation is not intended to limit the invention to railcar applications alone. | A load restraining device that provides a system in which straps extending from one side of a web strap arrangement initially run parallel to the wall to which they are connected, as opposed to extending perpendicular to the wall as in the prior art. The anchor itself is a horizontal wall member running longitudinally along the wall of the railcar or trailer. An adjustable anchor is used to permit moving the attachment point several inches to allow for load variations. The attachment of the web strap arrangement is normally 14″ to 18″ behind the face of the load. Unlike previous systems, this provision of anchor points behind the load effectively “encapsulates” the load rather than merely providing a bulkhead effect. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
A modification and improvement of the respirating pump structure disclosed in Applicants' simultaneously filed METHOD FOR SAMPLING AIR IN PROPORTION TO RESPIRATION (Ser. No. 901,654 filed May 1, 1978). Other copending applications are Ser. No. 901,861 and Ser. No. 901,862, both filed May 1, 1978.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
Although a considerable variety of instrumentation such as impingers, cascade impactors, battery powered air samplers, diffusion collectors and gas-stain detector tubes has been developed for application in monitoring ambient and industrial atmospheres, none may be considered to measure the exposure of an individual to noxious airborne components. All electrically powered and diffusion collection devices fail to measure the varied intake of undesirable gases and particulates which are inhaled into the lungs of an individual, as diverse demands for oxygen are met in response to a range of physiological activities. Thus, exposure to deleterious gases or particulates during periods of high levels of physical activity which result in deep and rapid inspiration are weighed equally in a statistical sense, with periods of shallow breathing in a clean environment by collection devices which sample air in uniform rates. For more accurate correlation with health phenomena it is highly desirable that air sampling for analytical determinations be proportional to the ventilation rate of the individuals under study.
2. Description of the Prior Art:
Being submitted separately under the provisions of 37 C.F.R. 1.97.
SUMMARY OF THE INVENTION
Method for sampling air pollution in proportion to respiration, comprising supporting an air sampling monitor adjacent the mouth of a respirant human, pumping air through the sampler, according as the respirant's thoracic cavity expands and contracts and gauging the amount of pollutants collected within the air sampling monitor as the amount of pollutants actually inhaled by the respirant during a given period. The suggested device includes a floating piston pump with air sampling inlet. The pump is supported adjacent the thoracic cavity and displays the volume of air being pumped in digital readout, as a function of total volume of air being inhaled by the respirant. The total volume of air is correlated with the amount of pollutants collected within the air sampling inlet during the given period.
A modified personal monitor utilizes a foam-filled belt or envelope which is fastened around the torso. Inhalation is accompanied in this device by forcing air under a floating piston which exhausts sampled air from the upper side of a cylindrical pump configuration. Exhalation draws air through a standard sampler tubing into the top of the cylinder.
In this device the expansion and contractions of the torso diameter are sensed by a soft, foam filled belt, or an air inflated belt or pad. This section is fastened at the rear of the torso with an adjustable coupling in order to accomodate various body circumferences. The belt or pad may be supported by a harness which has straps which pass over the shoulders. The harness may also have leg straps or belt connectors for use when motion is sufficiently vigorous to cause displacement of the belt.
The belt is adjusted to fit the wearer during an exhalation. During inhalation when the diameter of the wearer increases, air is forced from the belt into the bottom or inner section of a cylinder housing. As the air enters it forces a floating cylinder which is sealed by a rolling diaphragm to move outwardly. During this movement air is exhausted from the outer section of the cylinder through an exhaust valve. As the piston passes its position of maximum displacement and starts to return to its original position, the pressure differential closes the exhaust valve and opens an intake valve which is connected to the sampling section and its connecting tubing. During the return stroke, air is drawn through the sampling section into the outer portion of the cylinder housing. This action controls sample introduction into the absorbent or particle filter sections. Air flow is controlled by two rubber poppet valves each of which consists of rubber discs sealing against rubber O-rings. These valves are relatively large in area and are closed by weak compression springs. A very small force is required to open each one. The inlet valve is positioned so that it opens when the pressure within the cylinder housing falls below atmospheric. The exhaust valve operates in the opposite fashion; it closes when the internal pressure is lowered.
Movement of the floating piston which is controlled by air pressure from the belt is recorded during its movement toward the base of the cylinder housing. All movements of the piston are transmitted to a digital counter by means of metal tape and a tape pulley positioned upon a counter shaft. A torsion spring is used to assist the return of the tape pulley to its original position. The digital counter, which is operated by the pulley and tape, registers piston movement in one direction, during exhalation. This selectivity is achieved by inclusion of a micro scale clutch and brake on the counter shaft. Thus, the counter is not in motion during the portion of the cycle corresponding to inhalation, when air is forced into the cylinder housing by the respiration of the wearer is directly determinable in terms of the revolution counter reading, multiplied by a fixed calibration factor. A volume of 100 ml of gas is drawn into the sampler for each 1" travel of the piston.
In order to avoid problems associated with slow leakage from the belt envelope or associated fittings, the connection between the belt and the inner section of the cylinder housing contains an equalization valve. The function of this valve is to allow the pressure within the belt volume to equilibrate with atmospheric pressure. Like the intake and exhaust valves in the sampling system it is fabricated of rubber and retained in position by a weak compression spring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary front elevation of a floating piston pump housing secured by an adjustable belt, and supporting both an air sampling tube and a five digit counter display;
FIG. 2 is a fragmentary horizontal section of the pump housing; and
FIG. 3 is a vertical elevation of a conventional air sampling tube, containing in this case silver wool, and attachable to the air inlet in the pump housing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A mechanical configuration for the floating piston pump is shown in FIGS. 1 and 2. Belt 1 is comprised of a flexible plastic material which is filled with a porous plastic foam. The foam filled belt forms a sealed envelope 2 which forces air through the inlet 3 to diaphragm 6 through a belt-to-diaphragm tube 4 and equalization valve 26 when the torso of the wearer expands during inhalation. As the air from belt 1 is forced into the expandable zone 10 between base plate 5 and rolling diaphragm 6, the transferred volume forces piston 7 to move axially within the cylinder housing 8. Additional support for cylinder housing 8 may be in the form of shoulder strap 27, shown fragmentarily in FIG. 1. Also, support loops 28 may be provided for securing the housing extensions 27 to the belt. Piston 7 moves outwardly against the pressure supplied by compression spring 9 until the air pressure within the belt envelope 2 and expansion zone 10, as well as the compressive forces of spring 9, are equal. This movement is accomplished by reducing gas volume 11 which is under piston 7. During this outward movement of piston 7, air is ejected through the exhaust valve 12. As wearer inhalation ceases, exhaust valve 12 closes and the inlet valve 13 opens, drawing air through the sample inlet tube 14. Sample inlet tube 14 may be of the type illustrated in FIG. 3, in the form of 1/2" I.D. plastic tubing containing a silver wool filling, a 0.5 microporous filter or an inner coating such as sodium bicarbonate. This sampling stroke continues until piston 7 is reseated at the bottom of the cylinder housing 8 with compression spring 9 at full extension.
Piston 7, which draws sample air through sample inlet tube 14, is loosely fitted into cylinder housing 8. No dimensional tolerances are required to obtain the pumping action of piston 7. The rolling diaphragm 15 supercedes all needs for careful fitting of the mechanical parts. Diaphragm 15 may be of the "Bellofram" type, having a one inch stroke upon a volume of 100 cc. of air. However, to keep piston 7 centered within housing 8, piston 7 is moved upon guide rod 16, secured at one end to base plate 5 and at its other end to cylinder housing 8. A guide bushing 17 is fitted into piston 7, so as to engage guide rod 16 and provide reproducible motion in the horizontal plane. Gas leakage between the expandable volume 10 and piston volume 11 is avoided by use of a Teflon O ring seal 18.
For determination of that volume of gas which is drawn into the volume 11 under piston 77, a five digit counter 19 is mounted within cylinder housing 8, so that rotation of the counter in one direction serves as a cumulative indicator of piston 7 travel.
The counter subassembly consists of counter 19 mounted upon shaft 28, an internal clutch 20 and brake 21, a metal tape 22, a tape pulley 23 and a torsion spring 24. As piston 7 moves away from base plate 5 during inhalation, the counter brake 21 is engaged, preventing the counter from rotating. However, clutch 20 is disengaged allowing the tape pulley 23 to rotate to collect metal tape 22. Torsion spring 24 acts to wind the metal tape 22 onto the tape pulley 23. When piston 7 reaches its position of maximum travel away from base plate 5 in each stroke, counter brake 21 releases, the shaft clutch 20 engages and the counter dial 25 rotates, while piston 7 returns to base plate 5. During this action, torsion spring 24 rewinds to its maximum torsion while the compression spring 9 exerts its minimum pressure. Thus, movement of piston 7 is recorded, while an air sample is being drawn through air sample inlet tube 14. By calibration against a dry test meter, the volume equivalent to a one digit change in the counter dial 25 has been determined. For example, for a 2.69 inch (o.d.) piston 7 operating in a 3.0 inch (i.d.) cylinder housing a travel of 1 inch corresponds to drawing a sample of 100 ml of air through the sampling tube. This would give a counter reading change of 10 units. That is, each counter unit is equivalent to 10 cc sample volume in this example.
The vertical display of the pump and counter is shown in the lower portion of FIG. 1. The air inlet tube 4 from belt envelope 2 to the gas space 10 under piston 7 may be provided with an in-line pressure equalization valve 26. | Device for sampling air in proportion to respiration, particularly the collection of air pollutants in proportion to the actual respiration of the wearer. The pump is supported adjacent the thoracic cavity by means of a harness and is activated by the expansion and contraction of the thoracic cavity during respiration, so as to draw air through an air sampling monitor. | 6 |
REFERENCE TO PRIOR APPLICATION
This application claims priority of U.S. provisional application Ser. No. 60/192,977, filed Mar. 28, 2000, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to network computing and, more particularly, to a distributed environment that supports massive groupware streaming and pier-to-pier packetized communications.
BACKGROUND OF THE INVENTION
Computer games and simulations, like most computer applications, have traditionally been limited to single play units (i.e. a single console which creates the display and is operated through one or several control devices or pads). The PC, because it can be networked via modems, on local network, or the internet, has opened up the possibility of games in which multiple player interact with each other.
Earlier work in this area describes one player connected to a single other player with simple modems. U.S. Pat. Nos. 5,292,125 and 5,350,176 to Hochstein and U. S. Pat. No. 5,538,255 to Barker describe computer game systems which can allow synchronized play between two players connect by a modem.
Later work, like U.S. Pat. Nos. 5,558,339, 5,896,444, and 5,956,485 to Perlman, describe small scale “client-server” models where a client came connects to a game server through a network. Because of game play models of this type being limited in the number of players which must be supported, most current PC games of this type allow a small number of players to interact, perhaps 10-30 players on a local area computer network. For small scale client-server games, the server can be simple and need not be optimized for the number of communication connections nor for quick/efficient access to game/client specific parameters.
Several newly release games, like Ultima Online and Everquest have expanded network player counts to the 1000-10,000 level. To achieve this level of multiple player interaction, these games use specialized central servers (or server clusters which are closely linked) which run programs that understand about all the players and how they interact with each other, thus, the individual player game systems are not complete without the central servers or server clusters. This technology has been described in the patent literature by U.S. Pat. No. 5,659,691 to Durward; U.S. Pat. No. 5,664,778 to Kikuchi and U.S. Pat. No. 5,668,950. U.S. Pat. No. 5,828,866 Hao et al. use the same concepts to distribute data in distributed CAD applications.
For the last several years, an alternative model for massive distributed play has been developed by elements of the U.S. Department of Defense and its contractors. This model is call “distributed simulation” because in its pure implementation, each client broadcasts its internal state changes (for instance object motions) to the network and reads all state changes from other clients to depict simulation changes which are computed on other client systems. Thus, no central server is needed to make the distributed system operate. The significant advantage of the distributed approach is that there is not a bottleneck at a central server (or server cluster), because each client can send data to another without going directly through a server.
The basics of this method of connecting applications into a network were refined from about 1985 to 1990 in a program generally name SIMNET. SIMNET technology was later renamed as DIS or Distributed Interactive Simulation. Some same publications from that period include Kraemer et al. (1987), Alluisi (1991), the DIS Steering Committee (1994), Calvin et al. (1995), Cosby (1995), Pullen et al. (1995) and later formal specifications documents from the IEEE (1278.1 and 1278.2 published in 1993 and 1995). Current Defense Department standards pertaining to distributed simulation, called the High Level Architecture or HLA, are published by the Defense Modeling and Simulation Office (1996).
In reality, some centralized functions still remain like finding all the players currently operating in the same distributed simulation space (so that the client can send and receive from them, the client needs to know their Internet or IP address). U.S. Pat. No. 5,685,775 to Bakoglu describes implementation of system like SIMNET but for operation via standard dial-up phone networking (SIMNET, DIS, and HLA have always assumed Interent LAN/WAN network architectures for higher state exchange rates). U.S. Pat. No. 5,775,996 to Othmer and U.S. Pat. No. 5,956,485 to Perlman describe brokering mechanisms which were similar to those integral to SINET systems as early as 1989. U.S. Pat. No. 5,899,810 to Smith and U.S. Pat. No. 6,006,254 to Waters et al. are examples of commercially targeted systems which were influenced by the DIS and HLA architecture.
Similarly, it may be advantageous to access certain centralized databases and files (like common descriptions of play area virtual terrain). These centralized functions, however, are characterized as being needed when a new client joins the simulations and when it leaves it. Thus, the more limited server is usually called a simulation broker, and can actually be implemented as part of the first client which initiate s new simulated space. Centralized database distributions are described in U.S. Pat. No. 5,659,691 to Durward; U.S. Pat. No. 5,984,786 to Ehrrman; and U.S. Pat. No. 6,006,254 to Waters et al., but none of these focus only on data needed only for joining, and rather, in the spirit of client-server multiplay, provide databases from centralized points which interact intimately with on-going game playing.
For simulations like those performed in military training, over relatively high-speed networks, this advantage can be realized. However, if the simulation client is operating through a lower performance link like a dial-up modem, replicating packets to all other clients in a large pool (potentially including 1000+ clients) is not practical (i.e. the speed of transmission over the slow link precludes sending to many clients at once). This problem at the client communication end has motivate ? most of the client-server type solutions referenced (Hochstein 5,292,125 and 5,350,176, Barker 5,538,255 -only two players at a time; Periman 5,558,339, 5,896, 444, 5,956,485, Durward et al. 5,659,691, Kikuchi et al. 5,664,778, 5,668,950, Bakoglu et al. 5,685,775, Barrus 5,736,990 -small numbers of players over bandwidth limited networks; Smith 5,899,810, Ehrman 5,984,786, Water et al. 6,006,254, Vange et al. 6,050,898, Kappler 6,064,677 -combination of distributed, client-server, and message priority queuing to improve performance in the network and on the central server). Work to overcome aspects of the problems which arise because of poor server or network performance are described by Barrus et. al. 5,736,990, Othmer et al. 5,775,996, O′Callaghan 5,820,463, Waters 5,920,862, Lambright et al. 6,015,348, Vange et al. 6,050,898, and Kappler 6,064,677.
One solution to this problem is inserting a repeater router, which reads packets from each client and resends them to all relevant other clients which need to see the particular state change. In a simple form this has already been defined for the Internet using a concept called multicast. In multicast, a source client and all of its destination peers establish a multicast connection so that when the client sends its packet once into the Internet, properly featured Internet routers (which are really in this case servers with repeater routers) replicate that packet and route it to all destination clients without the source client sending the data out multiple times.
Some replication methods used in multicast have described by Chen et al. U.S. Pat. No. 5,666,360 and in numerous Internet published Request For Comment (RFC—these publicly distributed papers describe all interoperability standards used to implement the modem Internet and its protocols for data exchange; RFC are solicited and published by the Internet Society). Some RFC and papers defining details of Internet Protocol (IP) based multicasting are defined in Deering, RFC 1112, Pullen et al. (1995), Armitage RFC 2022 and RFC 2191, Fenner RFC 1112, Talpade et al. RFC 2149, and Pullen et al. RFC 2502 and RFC 2490.
Multicast, as built into some Internet routers and backbones, is conceptually very simple. One packet from a source goes in and multiple packets to multiple clients go out (more or less by copying or replicating the input packet). The service as currently designed has been built for replication data from one point in to many out to deliver media like digital video or digital audio (the digital Internet equivalent to broadcast TV or radio). For this type of use, there is no way to reduce replication effort through knowledge of the data being sent-if a client is “tuned” to a digital TV station, it needs copies of the packets being sent from that station (or packet source).
Some of the RFC disclosed applications specific streaming protocols for audio, video, and other data are defined in Schulzrinne, “RTP Profile for Audio and Video Conferences with Minimal Control,” RFC 1890; Schulzrinne et al., “RTP: A Transport Protocol for Real-Time Applications,” RFC 1889 and Real Time Streaming Protocol (RTSP),”RFC 2326; Defense Modeling and Simulation Office, High Level Architecture Riles Version 1.0; Handley et al., “SDP: Session Description Protocol,” RFC 2327, and Arango et al., “Media Gateway Control Protocol (MGCP) Version 1.0,” RFC 2706.
In Pullen et al., “A Simulation Model for IP Multicast with RSVP,” RFC 2490, the authors points out a number of deficiencies in using current IP multicast to service distributed simulation. These center around the difficulty in allowing a specific simulation client into and out of multicast groups (i.e. groups which will need the clients state broadcast packets) quickly (presumably due to some application culling rule changes as a client simulation executes). This presumes that making and breaking multicast group membership is the best way to optimize packet flows.
However, rather than making multicast more efficient (which is certainly a good idea, especially for applications independent uses) in distributed simulation and gaming, an alternative of making the routing system more intelligent about what and where data is needed can also have a significant impact on overall group or federation performance. Consider that quite a bit of knowledge is available about the source and destination clients and the objects being simulated or displayed on these clients. For instance, if the object on a client station which represent client avatar (or player self) in the game is in one place, it will not be able to see another object being simulated by another client if that object is (1) behind a wall, (2) too far away, (3) moving too quickly, (4) obscured by smoke or weather, to name a few simple culling rules.
Similarly, since each object is a depiction of something with acceleration and mass properties, it cannot change is location, velocity, or acceleration outside of some operating envelope. This means that each client can track objects and predict within some error bound where they will be at each point in the future. If the predicted value is close enough to the value from the client where the object is being created (and probably controlled by a player), its state changes need not be sent to other clients which can used the predicted location. Updates are only required when predictions are different from actual location by a large enough amount to effect the quality of play.
Culling rules based on proximity in the network [Seaman U.S. Pat. No. 5,644,571], proximity in virtual space [Barrus et al. U.S. Pat. No. 5,736,990], [Waters et al. U.S. Pat. No. 5,841,980], [Waters U.S. Pat. No. 5,920,862], and [Lambright et al. U.S. Pat. No. 6,015,348], and priority [Vange et al. U.S. Pat. No. 6,050,098] and [Kappler et al. U.S. Pat. No. 6,064,677] have been used in client-server systems. However, these concepts have not been extended into IP multicast or conventional routers.
The advantages of putting application-specific information actually into the routing system are many. Backbone routers provide the highest level of access to the Internet. Thus, routing data from lower echelon networks (and client-point-to-router connections) into an upper echelon router, which in turn, determines routing quality of service based on the needs of the federation (i.e. the needs based on source and destination state data which is available to the router because of the record of past packet traffic through it), can substantially reduce overall traffic over the backbone. Since network traffic is directly translatable to cost and performance, utilizing application (game) specific data routing performance and packet traffic reduction rules reduces cost and while improving multiplay game play performance. Culling rules inserted into the router is a specific instance of the concept of inserting portable applications or applets into the route. This is analogous to adding special purposed functionality to a general purpose web by adding applets (which might be downloaded into it).
SUMMARY OF THE INVENTION
This invention broadly resides in a network computing environment and method that facilitates many-to-many data streaming with substantial message culling as well as more standard network optimization such as conventional multicast and Internet host packet routing. The approach allows a very large (i.e., greater than 100,000) number of client applications to communicate logically through a multicast cloud over a common carrier such as the Internet to implement massive groupware configurations including distributed simulations, games, and client selectable/controllable data services used to broadcast audio, video, or other digital data.
According to a preferred embodiment, the technology utilizes three primary components; namely: client software, lobby management, and specialized routing functions. The client software, preferably through an applications programming interface, or API, connects a game client to a lobby manager or broker to initiate entry or joining of a federation (or a game cloud made up of all active players). The lobby manager or brokering software accepts initial client connection, provides a means for validating the client's simulation software (i.e. checks databases and code bases for compatibility with the federation) and provides a means for downloading data to correct deficiencies.
One or more routing systems accept attachments by clients upon direction of one or several lobby managers. The routing systems are able to apply game-specific packet culling rules to and from clients based on programmed logic supplied by qualified programming stations (central router control stations, game lobby managers and/or clients depending on security considerations). Thus, a router can exhibit application stream-specific behaviors in addition to normal packet routing behaviors.
The technology in the preferred embodiment is designed to implement massive distributed games and simulations, however, the technology is equally valuable in implementing other massive groupware Internet applications which benefit from special purpose applets which can be downloaded and executed within the router triggered as part of router message flow control. An example is the distribution of user customizable video, audio, or other digitized information (like medical data).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the structure of the RTI implemented per the DMSO specification;
FIG. 2 shows the invention's use of a separated routing function and a lobby manager function;
PROGRAM LISTING 1 illustrates the use the “HelloWorld” example from DMSO to illustrate how a client application is built according to the invention;
PROGRAM LISTING 2 illustrates how a client publishes and subscribes to a objects and their data using “PublishAndSubscribetoObjects”;
FIG. 3 is a diagram that illustrates how processes for the same federation on various router machines are able to communicate and route client messages from one to another;
FIG. 4 shows a sample network connecting seven clients to one of two repeater routers through a single LobbyManager;
FIG. 5 is a diagram that shows how a status update need not need to be done 10 times for each client connected to repeater router 2 between the repeater routers;
FIG. 6 shows how, if one starts with “CybemetBaseEntity”, which consists of double Altitude, double Latitude, and double Longitude, one can define a culling “member function called “CheckCube” for “CybemetBaseEntity”;
FIG. 7 shows how a new FederationHost process is launched according to the invention;
FIG. 8 shows how a federation is joined by a new client assuming that the repeater router is not overloaded;
FIG. 9 shows how a federation is joined by a new client assuming that the repeater router is overloaded and must start a new process on a new router;
FIG. 10 shows how packets are forwarded to other FederationHosts;
FIG. 11 shows how a routing system according to the invention scales with the total number of connections, which are typically distributed in hardware located across the larger Internet; and
FIG. 12 shows how a user controlled client application might provide controls for selection of different channels from one or many different sources.
DETAILED DESCRIPTION OF THE INVENTION
This invention broadly resides in a network computing environment and method that facilitates many-to-many data streaming with substantial message culling as well as more standard network optimization such as conventional multicast and Internet host packet routing through insertion of message traffic or application-specific applets into the message routing system (or into routers). The approach allows a very large (i.e., greater than 100,000) number of client applications to communicate logically through a multicast cloud over a common carrier such as the Internet to implement massive groupware configurations including distributed simulations, games, and client selectable/controllable data services used to broadcast audio, video, or other digital data.
Key innovations of the method include the following:
1) To insert a repeater router (or server cluster) into the Internet backbone to eliminate client packet output replication in favor of sending output packets to the repeater router, which in turn, replicates the packets to the relevant clients. This function with no packet culling is equivalent to multicast implemented by Internet routers that support multicast, but in networks without multicast routers, this function can be implemented by plug-in server which accepts packets and replicates each pack from a particular input client (i.e. IP address) to a list of output clients (i.e. output IP addresses). The address list for each input client is established through a connection protocol that allows the client or a third-party brokering server to associate an output IP address list with each input IP address.
2) To insert rules (or message flow triggered applets) into the repeater router which can decode input packet data and use this information to control replication (i.e. applications-specific programming code which implements packet routing service quality, routing, and culling). Examples of such culling rules include the following: (a) Each client can continuously predict where an object simulated by another client will be absent of control input. If the error between prediction and actual is small enough, the repeater router need not forward any state change packets from source client to destination client. (b) If the destination client has a viewing port then no data from source clients which are outside of the destination client view port need be forwarded. (c) If the destination client is beyond a certain range from the source client no data need be forwarded from out-of-range source clients need be forwarded.
3) To provide a brokering server (or server cluster) which can provide to the repeater router address lists which connect each source client to its destination clients and provide the applets (in the specific case, the packet decoding and culling rules) to the repeater router which allow the repeater router to only forward packets needed based on destination client visibility requirements. Culling rules or code can be provided by any qualified host, client, broker, or a designated network control host.
The communications system for implementing distributed simulation specifically, and other applications where the routing element includes applications data stream dependent information in its routing decisions, is based on extending the concepts defined by the High Level Architecture” (HLA) defined in Defense Modeling and Simulation Office, High Level Architecture Rules Version 1.0, US Dept. of Defense, August 1996. HLA in its defined form is a general purpose architecture for simulation reuse and interoperability. It consists of three parts: (1) HLA Rules, (2) HLA Interface Specification, and (3) Object Model Template Specification. HLA in a client applications is implement through the applications programming interface embodied by the Run Time Infrastructure or RTI.
HLA rules define HLA, its components, and the responsibilities of federates and federations. The HLA Interface Specification is a language independent specification for the HLA functional interfaces between federates and the runtime infrastructure (RTI). An simulation client, or one of many simulations which are joined in their execution, is called a federate. A group of these client together is called a federation. HLA defined interoperability of federates (i.e. how a federation works), and allows for multiple execution of simultaneous federations.
To support its general goals, the HLA requires that federations and individual federates be described by an object model which identifies the data exchanged at runtime in order to achieve federation objectives. This is called the Object Model Template Specification(OMT). The HLA OMT provides a template for documenting HLA-relevant information about classes of simulation or federation objects and their attributes and interactions. This common template facilitates understanding and comparisons of different simulations and federations, and provides the format for a contract between members of a federation on the types of objects and interactions that will be supported across its multiple interoperating simulations.
The implementation of The RTI or Run-Time Infrastructure software provides a set of services which are used by federates to coordinate their operations and data exchange during a runtime execution. The first RTI enable client also serves as a federation broker to help new federates join the federation (or leave it). The RTIs within the federation share federate contact data so the federation will persist as long as any single federate stays connect into it.
Like DMSO's HLA specification, this invention includes an RTI, or run time interface, to the client simulation application. In small local area simulations, our RTI can operate just as the DMSO version does (i.e. no centralized or specialized communications processes—just a community of federates endowed with a common RTI). However, when federations which span the Internet are contemplated, two additional functions are present. FIG. 1 shows the structure of the RTI implemented per the DMSO specification. FIG. 2 shows an implementation which contains a separated routing function and a lobby manager function.
The lobby manager function or broker takes charge of joining and exiting federations. The routing function which accepts all communications to and from a federate with its federation. The routers are aware of all connected federates within a federation and can be replicated and placed at convenient points within the Internet backbone (typically within data centers). Since each router services or concentrates communication to and from a maximum number of federates, the routers also know how to package and route data to and from each other simulating the total multicast connectivity assumed in the original DMSO implementation of HLA. In addition, since each router sees the data streams to and from all of its assigned federates, it can operate quality of service rules which control routing performance based on application-dependent rules. This substantially reduces backbone (between routers) and federate connection (from router to federate or simulation client) bandwidth.
The preferred RTI (the “Cybernet RTI”) can be used under with any simulation operating system including Microsoft Windows 9x, Windows NT, and Windows 2000. The RTI is implemented by two distinct code modules: the HLA-RTI.DLL (in Windows systems a file with suffix DLL is a code library) and LobbyManager.exe (in Windows a file with suffix .exe is an executable program or process—in this case it implements the lobby manager function).
LobbyManager.exe is a command line application. It maintains a list of running federations. Applications can call LobbyManager.exe by remote procedure calls (RPC calls to get information such as a complete list of running federations, the host machine for each federation, etc. Alternative implementation of remote messaging and request for procedure execution, perhaps through direct socket connections from called process to LobbyManager process will be possible and acceptable. HLA-RTI.DLL is linked into the client application or federate at build or run time.
When hosting a federation (typically within a local network-type setting), it can maintain a list of federates in the federation, or (typically in the Internet setting) can let a FederationHost process spawned by LobbyManager to maintain this list. The host (either HLA RTI.DLL itself or the FederationHost process) reads and parses the FED file to initialize a list of message object classes as well as to define a list of interaction classes. Subsequently the HLA RTI.DLL or FederationHost process maintains these lists for the federation and keeps track of published and subscribed object and interactions of each federate. When reliable data transmission is required, the HLA RTI.DLL or FederationHost process distributes data to each federate. One or the other (implementing the lobby manager function) also acts as a client federate for the local computer that is doing the hosting. When acting as a client federate, the lobby manager function connects to the federation host, and provides all RTI interface API's to the application.
The FED file in this implementation is labeled with a suffix of “.FED”. This file is compatible with the DMSO FED file format so it can be created and edited with “Object Model Development Tool (OMDT)” from Aegis Research or simply as an ASCII file with any text editor. An example of what goes in this file to define objects and interaction classes is “HelloWorld.fed” from DMSO available from http://hla.dmso.mil. The following values (stored in the registry in a Windows system) can be modified to customize the installation into a federate by functions provided in the HLA DLL Library (i.e. from in the Software Development Kit or SDK). The implementer of a client application might provide the means for a game user to modify these parameters (for instance by including a dialog box in the application to allow end user to modify parameters). These represent typical parameters an implementer might change:
1 Address. IP address for the machine on which the LobbyManager runs. For example, 192.168.0.2 2. Port. Port that LobbyManager uses. The default is “2000”. It is a string value. 3. Address. Multicast IP address. The default is 224.9.9.1. 4. Port. Multicast port base value. The default is 22500. It is a DWORD value. This base address is used by LobbyManager to acknowledge its own existence. Each federation receives a multicast port address from the LobbyManager, which is larger than the base value and smaller than or equal to the maximum port number. 5. MaxPort. Maximum multicast port number. The default is 23500. When all ports between the base port and this port are used up, no more federations can be created. 6. TTL. Multicast TTL. 7. NICAddress. Network interface card IP address. This can be useful when multiple NICs are in a machine. 8. QueueSizeLimit. Multicast is used for “best effort” communication. Multicast packets are placed in a queue when they arrive. If the queue size has reached this limit, new packets will be abandoned. 9. Address. This is a network interface card IP address that is used when hosting a federation. It can be useful on a multiple NIC machine. 10. Port. This is used for TCP connections while hosting a federation.
The LobbyManager process must be started either as a stand-alone application (which would be typical for Internet play— FIG. 2 ) or by spawning it from a client application (the first federate on a local network for localized play— FIG. 1 ). The process reads the LobbyManager start-up values (on a Windows implementation in the LobbyManager section in the registry). Other than setting up these values if they need to be changed from their defaults, client code does not need to do anything more for LobbyManager for local play. Starting the LobbyManager replaces the “rtiexec” or “fedex” commands used in the DMSO implementation.
In the client or federate code, a HLA 13 RTI::CLobbyManager class must be created, making sure that this class is present at startup time as well as shutdown time. At startup time, its “Init” member function is called to initialize it, and at shutdown time, its “DeInit” member function is called to clean up. The prototype of the Init function is BOOL Init(BOOL fsearch, DWORD dwTime, BOOL fUseLocalAddress), where “BOOL fsearch” specifies whether to search for LobbyManager.exe via multicast ping.
If the LobbyManager.exe has already started (as is the case when joining Internet play), it is spawned by the first federate, fsearch should be set to FALSE. “DWORD dwTime” specifies how long to wait for a search to complete if fsearch is TRUE. If “BOOL fljseLocalAddress” is TRUE, it is assumed that LobbyManager.exe is running locally. Otherwise the assumption is that it is running at IP address specified in the registry. “DeInit” does not take any parameters. Functions available after “Init” is called and before “DeInit” is called, are the same as those defined in the standard DMSO RTI (examples are provided by DMSO, such as the “Hello world” sample program).
The Cybernet RTI is an SDK is compiled and linked with C++applications, for instance, within Windows environments. It includes a setup program that installs the necessary components for a developer. The CybernetRTI example implementation is to be used with Microsoft Visual C++ version 6.0. The code generated with CybernetRTI will run under Microsoft Windows 9x, Windows NT 4.0, and Windows 2000.
The C++ header files that are included into client applications are RTI.hh, RTITypes.hh, LobbyManager.h, and HLA_RTIProfile.h. They are placed in the <Installation Directory>\include. The only difference between RTI.hh, RTITypes.hh and the comparable versions from DMSO is that static functions use “fastcall” declaration specifications. Other include files are that same as those available from the DMSO distribution of HLA.
There is one lib(brary) file that is linked into the client application. This is HLA_RTI.lib. It is placed in <Installation Directory>\lib. Following we use the “HelloWorld” example from DMSO to illustrate how the client application is built. In a client application that uses RTI, the first few things the client includes are declarations for a HLA_RTI::CLobbyManager class, a CFederateAmbassador class (see PROGRAM LISTING 1), and a text string char *szFederateName that uniquely identifies the federate.
The CFederateAmbassador FedAmb class is derived from RTI: :FederateAmbassador, and overloads some of the RTI: :FederateAmbassador member functions. These overloaded functions are callback functions. When something happens on the network, one of the callback functions will be called. Some of the most useful ones are listed below:
void CFederateAmbassador::startRegistrationForObjectClass
( RTI::ObjectClassHandle theObjectClass)
throw (RTI::ObjectClassNotPublished, RTI::FederateInternalError) ;
This function is called within a federate when another federate on the network is interested receiving data from objects of this class which the first federate publishes. A federate registers for objects in this class to signal to another federate which publishes in the class that it wishes to see state updates as they publish.
void CFederateAmbassador: :stopRegistrationForObjectClass(
RTI::ObjectClassHandle theObjectClass)
throw (RTI::ObjectClassNotPublished, RTI::FederateInternalError) ;
This function is called when no client on the network is interested in receiving data from objects in this class which a federate publishes. A federate can unregister objects in this class published by another.
VoidCFederateAmbassador::turnInteractionsOn(RTI::InteractionClassHan-
dle theInteraction)
throw(RTI::InteractionClassNotPublished, RTI::FederateInternalError) ;
This function is called when a federate on the network is now interested in the interaction another has published. A federate updates interactions in this class that is publishes.
VoidCFederateAmbassador::turnInteractionsOff(RTI::InteractionClassHan-
dle theInteraction)
throw(RTI::InteractionClassNotPublished, RTI::FederateInternalError) ;
This function is called when no client on the network is interested in the interaction another publishes. A client stops updating interactions in this class that it publishes.
void
CFederateAmbassador::discoverObjectInstance(RTI::ObjectHandle
theObject,
// supplied C1 RTI::ObjectClassHandle
theObjectClass,
// supplied C1
const char *theObjectName) // supplied C4
throw(RTI::CouldNotDiscover, RTI: :ObjectClassNotKnown,
RTI::FederateInternalError) ;
This function is called when an object of a class to which a client subscribes is registered on the network. The client creates an object locally and stores “theObject.”
void CFederateAmbassador::reflectAttributeValues(RTI::ObjectHandle
theObject,
// supplied C1
const RTI::AttributeHandleValuePairSet& theAttributes,
//
supplied C4 const char *theTag)
//
supplied C4
throw(RTI::ObjectNotKnown, RTI::AttributeNotKnown,
RTI::FederateOwnsAttributes, RTI::InvalidFederationTime,
RTI::FederateInternalError) ;
This function is called when an object which a client had previously discovered is updated. The updated values are in “theAttributes.” The object is identified by “theObject,” as specified in the previous function.
void CFederateAmbassador::reflectAttributeValues(RTI::ObjectHandle theObject, // supplied C1 const class RTI::AttributeHandleValuePairSet &theAttributes, const class RTI::FedTime &theTime, const char *theTag, struct RTI::EventRetractionHandle_s) throw (RTI: ObjectNotKnown, RTI::AttributeNotKnown, RTI::FederateOwnsAttributes, RTI::FederateInternalError) ;
This function is the same as the previous one except it includes a time input.
void
CFederateAmbassador::receiveInteraction(RTI::InteractionClassHandle
theInteraction, const class
RTI::ParameterHandleValuePairSet &theParameters, const char
*theTag)
throw(RTI::InteractionClassNotKnown, RTI::InteractionParame-
terNotKnown,
RTI::InvalidFederationTime, RTI::FederateInternalError) ;
This function is called when an interaction which applies for a class to which a client has subscribed is updated on the network. The updated values are in “theParameters.”
void
CFederateAmbassador::receiveInteraction(RTI::InteractionClassHandle
the Interaction,
const class RTI::ParameterHandleValuePairSet &theParameters,
const class RTI::FedTime &theTime, const char * theTag, struct
RTI: EventRetractionHandle_s theHandle)
throw (RTI::InteractionClassNotKnown, RTI::InteractionParame-
terNotKnown,
RTI::FederateInternalError) ;
This function is the same as the previous one except it includes a time input.
void CFederateAmbassador::removeObjectInstance(RTI::ObjectHandle
theObject,const char *theTag)
throw (RTI::ObjectNotKnown, RTI::InvalidFederationTime,
RTI::FederateInternalError);
This function is called when an object that a client previously discovered is removed. The object is identified by “theObject,” as specified in “discoverObjectlnstance.”
void CFederateAmbassador::removeObjectInstance(RTI::ObjectHandle
theObject,const class RTI::FedTime &,const char *theTag, struct
RTI::EventRetractionHandle_s)
throw(RTI::ObjbectNotKnown, RTI::FederateInternalError) ;
This function is the same as the previous one except it includes a time input.
void
CFederateAmbassador::provideAttributeValueUpdate(RTI::ObjectHandle
theObject, const class RTI::AttributeHandleSet &theAttributes)
throw(RTI::ObjectNotKnown,
RTI::AttributeNotKnown,RTI::AttributeNotOwned,
RTI::FederateInternalError) ;
This function is called when a federate on the network requests that another subscriber update data for an object that has been already registered. The object is identified by “theObject,” as specified in “discoverObjectlnstance.”
void
CFederateAmbassador::turnUpdatesOnForObjectInstance(RTI::Object
Handle theObject,const class RTI::AttributeHandleSet
&theAttributes)
throw(RTI::ObjectNotKnown,
RTI::AttributeNotOwned,RTI::FederateInternalError) ;
This function is called when a client on the network is now interested in data from an object that the sourcing client previously registered. The object is identified by “theObject,” as specified in “discoverObjectlnstance.” The sourcing client application starts updating of this object on the network.
void
CFederateAmbassador::turnUpdatesOffForObjectInstance(RTI::ObjectH
andle theObject,const class RTI::AttributeHandleSet
&theAttributes)
throw(RTI::ObjectNotKnown,
RTI::AttributeNotOwned,RTI::FederateInternalError) ;
This function is called when no client on the network is interested in an object that sourcing client has previously registered. The object is identified by “theObject,” as specified in “discoverObjectlnstance.” The sourcing client stops updating of this object on the network.
PROGRAM LISTING 2 illustrates how a client publishes and subscribes to a objects and their data usingf “PublishAndSubscribetoObjects.”
The CheckExitSignal function's prototype is “BOOL CheckExitSignal(void);”. It is a very simple function that may be used in a command line application or it may be simply used as follows
BOOL CheckExitSignal(void){ return (_kbhit() == 0) ; }
If it is a GUI application, it may be used as:
BOOL CheckExitSignal(void){ return fExit; }
where BOOL fExit=FALSE initially and is set to TRUE when WM_QUIT is received.
The following are descriptions of key Interface Classes. The HLA_RTI:Cprofile class is declared in HLA_RTIProfile.h. All members in this class are static. All registry section name strings and entry name strings, along with default profile values are declared within it. The following are examples:
static UINT MS_FASTCALL GetInt(LPCTSTR lpszSection,LPCTSTR
lpszEntry, int nDefault) ;
Example:
DWORD dwMaxPort =
HLA_RTI:CProfile::GetInt(HLA_RTI:CProfile::m_szMCastSection
,HLA_RTI: CProfile::m_szMCastMaxPortEntry,
DEFAULT_MAX_MCASTPORT) ;
static CString MS_FASTCALL GetString(LPCTSTR
lpszSection,LPCTSTR
lpszEntry,LPCTSTR lpszDefault) ;
Example:
CString szLobbyManagerAddress
=HLA_RTI:CProfile::GetInt(HLA_RTI:CProfile::m_szLobbySectio
n,HLA_RTI:CProfile:: m_szLobbyAddrEntry, “192.168.0.1”) ;
static BOOL MS_FASTCALL WriteInt(LPCTSTR lpszSection,
LPCTSTR lpszEntry, int nValue) ;
Example:
HLA_RTI:CProfile::WriteInt(HLA_RTI:CProfile::m_szMCastSec
tion,HLA
_RTI:CProfile::m_szMCastMaxPortEntry, dwMaxport) ;
static BOOL MS_FASTCALL WriteString(LPCTSTR lpszSection,
LPCTSTR
lpszEntry, LPCTSTR lpszValue) ;
Example:
HLA_RTI:CProfile::WriteString(HLA_RTI:CProfile::m_szLobbySec
tion,
HLA_RTI:Cprofile:: m_szLobbyAddrEntry,
szLobbyManagerAddress) ;
The HLA_RTI:CLobbyManager class is declared in
LobbyManager.h.
void DeInit(void) ;
This function is called when exiting RTI code.
BOOL Init(BOOL fSearch, DWORD dwTime, BOOL
fUseLocalAddress) ;
This function is called when initiating RTI code. BOOL fsearch: specifies whether to search for LobbyManager.exe via multicast ping or not. If the caller knows a LobbyManager.exe has already been started, or it is going to start it, the caller can set fsearch to FALSE. DWORD dwTime: is used if fsearch is TRUE to specify how long to wait for a response from the LobbyManager to the search request. BOOL fUseLocalAddress is TRUE, if the caller assumes that LobbyManager.exe is running locally (on the same machine making the call). Otherwise the caller assumes that the LobbyManager is running at an IP address specified as a start-up value (in the registry for Windows).
static BOOL MS_FASTCALL IsLobbyManagerRunning(void) ;
This function checks to determine if LobbyManager.exe is running.
static void MS_FASTCALL ShutDown(void) ;
This function will shutdown LobbyManager.exe.
The extensions provided by this invention modify the functionality of the LobbyManager and support multiple routing functions which aggregate traffic to and from clients and forward that traffic to other clients or routers based on application dependent evaluation of the messaging streams (based on culling rules). The changes and extensions to implement this functionality are described in this section.
In DMSO version of the RTI, a list of active federation executions is maintained by an executable called rtiexec. Every federation execution is created and destroyed by rtiexec. In Cybemet's version of RTI, described in the previous section, rtiexec is replaced by LobbyManager. Besides simply replacing rtiexec, LobbyManager also has the following extended features:
Additional APIs Additional Runtime Options Mtunnel/FederationHost functionality
LobbyManager can be called directly from an RTI enabled client application or federate by RPC (Remote Procedure Call or other equivalent communication mechanism) to obtain information about the list of active federation executions. The following are member functions of HLA_RTI::CLobbyManager class, which is declared in LobbyManager.h:
static BOOL FedexExist(const char *pExecutionName);
This function can be called to see if a federation named with pExecutionName already exists. It returns TRUE if it exists, and FALSE otherwise.
static int FindLobbyMember(const char *pLobbyMemberName,
_SLobbyMember *pLobbyMember);
This function can be called to retrieve information about a federation named with pLobbyMemberName. It returns TRUE if successful, and FALSE otherwise. The requested information is returned in pLobbyMember. The memory space of pLobbyMember is provided by the caller.
static CString * GetHostID(const char *pszHostName);
This function retrieves the application-specified ID of a host of a federation named with pszHostName. It returns NULL if failed.
static BOOL GetHostInfo(const char *pExecutionName, unsigned char
szAddress[16], unsigned char szPort[8]);
This function retrieves information needed for making a TCP connection to the host of a federation named with pExecutionName.
static CString *GetModelName(const char *pszHostName, const char
*pszID);
This function retrieves the application-specified model name of an object with ID specified by pszID in a federation hosted by pszHostName. It returns NULL if failed.
static BOOL GetFederateList(const char *pLobbyMemberName,
CTypedPtrList<CPtrList, CString *> *pStringList);
This function retrieves the list of federates in a federation hosted by pLobbyMemberName.
static int GetLobbyMemberCount(void);
This function retrieves the number of hosts available.
static int GetLobbyMemberNames(long lBufferSize, char *pBuffer);
This function retrieves the names of all available hosts. Each name is a string of 32 bytes in length with NULL-termination.
static CString * GetScenarioTitle(const char *pszHostName);
This function retrieves the application specified scenario title of a federation hosted by pszHostName.
BOOL JoinGameLobby(const char *pszModelName, const char *pszID,
const char *pszScenarioTitle, CFederateList &FederateList);
This function is called implicitly if not called explicitly before creating a new federation. Calling it directly before creating a new federation gives the application option to store additional information about a federation into the federation list maintained by LobbyManager.
void
SetHostListChangeCallbackProc(HostListChangeCallbackProc
pProc);
This function allows application to setup a callback function. When there is a change in the list of federations, the application will be notified via the callback function. Additional run-time features which support Internet gaming allow the LobbyManager to be placed on a “broker server” computer to manage larger networks of federations over the Internet. The first feature for such purpose is user authentication. An application can use the “Login” member function of HLA_RTI::CLobbyManager class to login to LobbyManager, and the “Logoff” member function to log off. HLA_RTI::CLobbyManager is declared in LobbyManager.h. Alternatively the user “login” can be accomplished via a game-specific web site which is authenticated as a site when the site (through CGI) logs into the LobbyManager through a secure command line interface.
LobbyManager can keep track of a list of “repeater router” machines. Each “repeater router” machine is running a copy of MTunnel to be discussed later. One task of MTunnel is to launch new processes on designated repeater router machines which are placed in data centers distributed about the Internet (based on backbone and client-to-routing machine load balancing considerations) for LobbyManager.
If a user requests to create a new federation, or to join an existing federation that already has too many members, a new federation host process will be launched on a repeater routing machine. All FederationHost processes for the same federation on various router machines are able to communicate and route client messages from one to another and each has information about each entire federation within which it operates. FIG. 3 provides a process flow of these operations.
For example, if a client requests LobbyManager to create a federation called “Fed 1 ”, LobbyManager makes sure that there is no federation called “Fed 1 ” on its network and then it creates a hosting process for the federation “Fed 1 ” on repeater router 1 which might be called “FederationHost 1 ”. When another client requests to join “Fed”, it will be assigned to FederationHost 1 on repeater router 1 . As more and more clients join “Fed 1 ,” the LobbyManager at some point will decide to create another process called “FederationHost 2 ” on repeater router 2 to host the same federation, namely “Fed 1 ,” and will direct newer clients to FederationHost 2 as the host. “FederationHost 1 ” and “FederationHost 2 ” share the same client list, the same object list, etc. Each will perform culling functions for the connected clients for which it is responsible.
Suppose that a client requests to create another federation called “Fed 2 .” The LobbyManager makes sure that there is no federation called “Fed 2 ” already defined on its network. Then it find the least busy Mtunnel router, say repeater router and creates a new FederationHost process called FederationHost 2 on repeater router 1 . When another client requests to join “Fed 2 ,” it will be assigned to FederationHost 2 on repeater router 1 . Router support for “Fed 2 ” will be grown based on the number of new connections just as it was for “Fed 1 .” FIG. 4 shows a sample network connecting seven (7) clients to one of two repeater routers, through a single LobbyManager. Because FederationHost 1 is implemented across the two repeater routers, they must be in communications to route messages from Fed 1 clients on one to the other as needed.
When managing a large network of federations over the Internet, LobbyManager will spawn as many FederationHost processes as needed to host a federation.
FederationHost is an executable, but it cannot be run by itself. It is always launched on a free router by LobbyManager through a process named MTunnel.
FederationHost performs all the host functions defined in the RTI code previously described. When there are multiple FederationHosts for a given federation, they communicate with each other via both TCP/IP connections and IP multicast. They will each maintain a complete list of federates, but each will communicate directly with a limited number of these clients.
Exactly which clients will communicate with a given FederationHost is determined by LobbyManager. The client code in HLA_RTI.DLL receives the IP address of an Mtunnel router and a port address of a FederationHost Process from the LobbyManager after it logs in. Then the client code will establish a TCP connection with the FederationHost (for reliable messages)as well as a UDP connection (for lower priority state change messages).
Because clients do not communicate directly with each other, network traffic is greatly reduced. For example, if FederationHost 1 on repeater router 1 is hosting 10 users, and FederationHost 1 on repeater router 2 is hosting 10 users, for the update of the status of a single client connected to repeater router 1 , there is going to be one and only one transmission of data from repeater router 1 to repeater router 2 . The status update does not need to be done 10 times for each client connected to repeater router 2 between the repeater routers. This is diagrammed in FIG. 5 .
FederationHost also performs the function of message culling to further reduce network traffic. Culling functions, which are typically application dependent, are defined as “member functions” of various attribute sets in FED files, which reside on repeater routers. These attribute set definitions are provided by the repeater router builder or applications developer in a FOM (Federation Object Model) library. Each function can be turned on and off at run-time. Certain culling functions can have parameters to be set at run time as well. Because one can derive new attribute sets from existing ones, modeling C++class derivation with single inheritance, we can create other attribute sets, and are not limited to what has been included in the base FOM library. Some culling functions slow down message service if two clients are far from each other in virtual space (i.e. do not need frequent position updates because position changes over short periods are small relative to mutual distance). Some culling functions exploit the fact that clients project new object positions as a function of last position, velocity, and acceleration. Thus, if an object is both subject to a significant control action, the difference between communicated state messages and the estimated position might be slight enough that the messages need not be forwarded. Other mutual visibility considerations generate culling rules, depending on the application. For instance, sometimes it is useful t divide the game space into zones. Within a localized zone, locations can be coded relative to the zone origin, and visibility might be restricted to only other objects in the same zone. Any and all of these culling functions can be implemented into the member functions in the FOM.
Referring to FIG. 6 , if we start with “CybernetBaseEntity”, which consists of double Altitude, double Latitude, and double Longitude, we can define a culling “member function called “CheckCube” for “CybernetBaseEntity”, which is defined as “Altitude-Altitude 0 >=a 1 and Altitude-Altitude 0 <=a 2 and Latitude-Latitude 0 >=b 1 and Latitude-Latitude 0 <=b 2 and Longitude-Longitude 0 >=c 1 and Longitude-Longitude 0 <=c 2 ”, where (Altitude 0 , Latitude 0 , Longitude 0 ) is a “CybernetBaseEntity” that belongs to the receiving federate. Also a new member function, namely EableCulling, is added to RTI::RTIAmbassador class. It allows applications to turn certain culling rules on and off.
The MTunnel is an executable process running on a repeater router. Each router has one and only one MTunnel process running. When LobbyManager needs to launch a new FederationHost process on a repeater router, it connects to MTunnel process on that repeater router using TCP/IP, and sends the request. MTunnel will launch the requested new FederationHost process and return the status of the new process to LobbyManager, so that a client application such as a game simulator can connect with the FederationHost process. FIG. 7 shows how a new FederationHost process is launched. FIG. 8 shows how a federation is joined by a new client assuming that the FederationHost router is not overloaded. FIG. 9 shows shows how a federation is joined by a new client assuming that the FederationHost machine (repeater router) is overloaded and must start a new FederationHost process on a new router. The game shown in the figures is OpenSkies, but this game can be replaced with any other.
Besides acting as a process launcher, Mtunnel also forwards IP multicast traffic from one repeater router to another using unicast, simulating multicast routing between Mtunnels, when an IP multicast connection is not available between routers. It selects routes of least travel for all forwarded data. FIG. 10 shows how packets are forwarded to other FederationHosts.
Combining FederationHost with Mtunnel processes, we can reduce network traffic through the Internet backbone considerably. If the topology amongst routers is such that a datagram can reach every node with a single pass on every connection segment, the amount of data sent across the Internet is simply proportional to the number of clients. Consider the example of a flight simulator. An aircraft needs to transmit its altitude, latitude, longitude in doubles, heading, pitch, bank in floats, and ID in 32 bit integer for a total of 76 bytes at 30 Hz, i.e., 220 bytes/sec, in UDP datagrams. This number can be further reduced by not sending the high 32 word of each double every frame, for example. So the number becomes 64 bytes at 30 Hz, i.e., 192 bytes/sec. If there are 100 players, the amount of data sent across the Internet backbone is 100*192 bytes/sec=19.2 kilobytes/sec. For 500 users, it is about 96 KB/sec.
Local traffic at each router will still be n-squared times 192 bytes/sec with the absence of culling. However, due to the limited bandwidth that is available to each end user, we further rely on culling to significantly reduce the amount of data sent to each user. Assume that the user is using a 56 kb/sec modem, the number of aircraft it can handle is about 10-15. Since we must leave room for infrequently transmitted data, plus things such as missiles and other projectiles, culling will limit the number of planes to 10. Cybernet FOM library is implemented to support substantial network traffic culling. Therefore, unlike general-purpose attribute set definitions, each variable type is specified. The only deviation in the preferred embodiment described here from the DMSO FED specification is the addition of culling rules and specification of variable types.
The following is a example list of the content of Cybemet FOM library in alphabetical order. Other culling rules in addition to CheckSquare and CheckCube can be defined on an application specific basis withing this framework.
1.
CBaseEntity2D
(class CBaseEntity2D
(attribute x besteffort receive)
(attribute y besteffort receive)
(culling CheckSquare double x double y)
)
2.
CBaseEntity. Derived from CBaseEntity2D.
(class CBaseEntity
(attribute z besteffort receive)
(culling CheckCube double x double y double z)
)
key innovation in the system implemented as the preferred embodiment is that the distributed network of client applications communicate to each other through reapter routing systems. These systems provide a means for connecting/disconnecting from the federation of simulation network (the LobbyManager) and for routing messages from client to client through the mediation of the routers (Mtunnel and FederationHost processes). The LobbyManager scales by simulation network (i.e. application or game and the number of “parallel” game universes or federations defined by the game operator or the players, depending on how the application space is implemented by its developer). The routing system scales with the total number of connections, and as shown in FIG. 11 , is typically distributed in hardware located across the larger Internet (or alternatively can be co-located in a single location of network). Spreading of the routing resources optimized transmission bandwidth lower by:
(1) providing points of concentration so that all clients need not connect directly to each other (2) providing intelligent gateways which can apply culling rules so that messages which would not be relevant to a particular client can be sent a a reduced quality of service or not at all
The technology in the preferred embodiment- is designed to implement massive distributed games and simulations, however, the technology is equally valuable in implementing other massive groupware Internet applications with similar characteristics. These characteristics are:
(1) many source clients producing messages or data streams for many destination clients (2) many messages produced will not be useful at destination client depending on setting or controls which are available to the destination user, but not directly to the source (3) routing points through which each source client sends and each destination receives and between which a concentrator or routing protocol can be used (to move bulked messages between routers when the source and the destination connect through different ones) (4) algorithms or culling rules which can eliminate or reduce quality of service to specific message streams to specific destination clients based on the contents of streams from the source and destination clients (since both destination and source clients communicate through the router which implements the rules, both can be consider sources for the purpose of rule execution).
Another example of an application which fits this model is distribution of user customizable video, audio, or other digitized information (like medical data). The user controlled client application might provide controls for selection of different channels from one or many different sources ( FIG. 12 ). Only a single feed need be forwarded through the repeater router based on the router's understanding of the controls settings made by the user's player application. For instance, assume ten (10) video capture servers code video streams from ten alternate viewing locations at a sporting event. The user selects at his/her viewing station which stream(s) are relevant to him/her. All streams are sent to a router for distribution (because different users may select views from any of the streams), but because the router knows which views are relevant to which viewers, only some data is forwarded through the router to each user client. This technology might be implemented via conventional multicast routing optimized for fast multicast group joint and unjoin functions, but the preferred embodiment in this disclosure is a preferred application when there are hundreds and perhaps thousands of sources and millions of destinations. In that setting the disclosed approach reduces total aggregate bandwidth orders of magnitude. | A method is described which allows a very large (greater than 100,000) number of applications to communicate logically through a many-to-many multicast cloud on the common carrier Internet efficiently by exploiting characteristics of the applications' data streams which allow substantial message culling as well as more standard routing optimization (conventional multicast and optimization standard to normal Internet routing systems). The method describes the function and type of three types of systems which operate together to implement the method. The first is a network enabled client application, such as a distributed simulation or game, which joins an application cloud or federation and communicates its internal state changes into the cloud via a communication applications programming interface. The second is a lobby manager or broker which accepts entry into a communication cloud or federation and provides information to the federation and the client application for establishing communications between them. And third, is a applications-specific routing system which provides the normal function of routing packets between Internet hosts (client applications running on these hosts), but also allows the routing functions to affected by modules in the router which are associated with the distributed application or simulation being implemented. These application “personalized” routing modules implement substantial application-specific message culling through message omission, rerouting, and other quality of service modifications to substantially reduce overall federation communication traffic and at the same time still effectively implement a point-to-multipoint distributed communications model between clients. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a manufacturing method for an organic optoelectronic thin film, and more particularly to a manufacturing method for an organic optoelectronic thin film that adds a polymer oxide to a semiconductor layer, and transfers the semiconductor layer to a conductive polymer layer.
2. Description of the Related Art
In the past, organic solar cells were generally manufactured by a solution manufacturing process. In the solution manufacturing process, a layer of solvent is coated onto a substrate first, and then the solvent is coated with poly(3-hexylthiophene) (P3HT) and phenyl C61-butyric acid methyl ester (PCBM). In the manufacturing process, the solvent will dissolve with P3HT and PCBM to cause various problems.
To overcome the aforementioned problem of dissolving solvents during the solution manufacturing process, R.O.C. Pat. No. I318334 by Kumar, A. and Whitesides, G. M. et al. as well as M. L. Chabinyc, et al. disclosed a micro-contact printing technology in 2004, and such technology is illustrated in FIGS. 1A˜1D .
In FIGS. 1A˜1D , the procedure of the micro-contact printing technology are demonstrated. In FIG. 1A , a silicon substrate 11 , whose surface is plated with a gold thin film 12 is shown. In FIG. 1B , a design pattern etched onto a surface is provided, and a layer of ink molecules 14 such as alkanethiol is formed on a poly(dimethylsiloxane) (PDMS) print mold 13 . The alkanethiol solution is poured onto the print mold 13 to ink the PDMS print mold 13 . In FIG. 1C , the gold plated silicon substrate 11 is in contact with the inked PDMS print mold 13 , the ink molecules 14 of alkanethiol on the print mold 13 are combined with gold atoms on the substrate 11 through the covalent bonding to form a self assembled monolayer. In FIG. 1D , after the PDMS print mold is removed, a layer with the design pattern is printed onto the gold plated silicon substrate 11 by the self assembled monolayer 15 with the covalent bonding of alkanethiol.
In the aforementioned manufacturing process of the PDMS print mold, the manufacturing process of the PDMS print mold is too complicated and time consuming. In addition, when the PDMS print mold is processed appropriately during the use of the PDMS is used, the number of times of using the PDMS print mold is also limited.
Therefore, it is the main subject for the present invention to simplify the solar cell manufacturing process and overcome the problem of dissolving solvents and using the PDMS print mold.
SUMMARY OF THE INVENTION
In view of the aforementioned problem, the present invention provides a manufacturing method for organic optoelectronic thin film, and the manufacturing method adds PEG into a semiconductor layer, and the semiconductor layer is transferred to a conductive polymer layer to solve the problems of the conventional solution manufacturing process that the solvents are dissolved by using the PDMS print mold of the micro-contact printing technology.
Therefore, it is a primary objective of the present invention to overcome the aforementioned shortcomings of the prior art by providing a manufacturing method for an organic optoelectronic thin film, and the manufacturing method comprises the steps of: providing a substrate and a first electrode; forming a semiconductor layer on the substrate, and the semiconductor layer including a polyethylene glycol; coating a conductive polymer layer on the first electrode; placing the substrate and the semiconductor layer on the conductive polymer layer, and attaching the semiconductor layer with the conductive polymer layer; removing the substrate; and evaporating a second electrode on the semiconductor layer to form the organic optoelectronic thin film; wherein a first adhesion is generated between the semiconductor layer and the substrate, and a second adhesion is generated between the semiconductor layer and the conductive polymer layer, and the second adhesion is greater than the first adhesion, such that when the substrate is removed, the semiconductor layer is still attached onto the conductive polymer layer.
In summation, the manufacturing method for an organic optoelectronic thin film in accordance with the present invention has one or more of the following advantages:
(1) The invention simplifies the manufacturing process, and saves the trouble of manufacturing the PDMS print mold to achieve the same transfer effect.
(2) The invention uses a roll-to-roll manufacturing process to coat the solution onto the flexible substrate quickly and easily, so as to further simplify the manufacturing process and reduce the manufacturing time for an easier entry of a mass production.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A˜1D show a procedure of a micro-contact printing technology;
FIGS. 2A˜2F show a procedure of a manufacturing method of a solar cell in accordance with a preferred embodiment of the present invention;
FIG. 3 is a graph of voltage versus current density of a solar cell manufacturing by a transfer method and a coating method of the semiconductor layer containing PEG and a coating method of a semiconductor layer of a solar cell without containing any PEG at 100 mW/cm 2 and with a standard solar energy simulated light of AM 1.5 G; and
FIG. 4 is a schematic view of a roll-to-roll manufacturing process of a solar cell in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The foregoing and other objectives, characteristics and advantages of the present invention will become apparent by the detailed description of a preferred embodiment as follows.
With reference to FIGS. 2A˜2F for the procedure of a manufacturing method of a solar cell 2 in accordance with a preferred embodiment of the present invention, the manufacture of the solar cell 2 as shown in FIG. 2A firstly provides a substrate 21 . The substrate 21 is one selected from the group consisting of a glass substrate, a polymer plastic substrate and an electronic circuit substrate, and the electronic circuit substrate is a silicon substrate. The polymer plastic substrate is made of a material selected from the group consisting of polyethylene teraphthalate (PET) and polycarbonate. In this preferred embodiment, the substrate 21 is, for example, the silicon substrate.
Secondly, a p-type semiconductor material and an n-type semiconductor material are used for producing a solution, and a poly(ethylene glycol) (PEG) of different molecular weights is added into the solution.
Finally, the substrate 21 is rinsed, and a spin-coating or deposition method is used for forming the solution onto the substrate 21 to form a semiconductor layer 22 .
The p-type semiconductor material is one selected from the group consisting of polythiophene, polyfluorene, polyphenylenevinylene, polythiophene derivative, polyfluorene derivative, polyphenylenevinylene derivative, conjugated oligomer and small molecule, and the polythiophene derivative is poly(3-hexylthiophene) (P3HT); the polyfluorene derivative is poly(dioctylfluorene); the polyphenylenevinylene derivative is poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene]; the conjugated oligomer is sexithiophene, and the small molecule is one selected from the group consisting of pentacene, tetracene, hexabenzcoronene, phthalocyanine, porphyrines, pentacene derivative, tetracene derivative, hexabenzcoronene derivative, phthalocyanine derivative, and porphyrin compound derivative.
The n-type semiconductor material is one selected from the group consisting of C60, C60 derivative, C70, C70 derivative, carbon nanotube, carbon nanotube derivative, 3,4,9,10-perylene tetracarboxylic-bis-benzimidazole (PTCBI), N,N′-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide (Me-PTCDI), 3,4,9,10-perylene tetracarboxylic-bis-benzimidazole (PTCBI) derivative, N,N′-dimethyl-3,4,9,10-tetracarboxylic acid dimide derivative, polymer and semiconductor nanoparticle; the C60 derivative is phenyl C61-butyric acid methyl ester (PCBM); the polymer is one selected from the group consisting of poly(2,5,2′,5′-tetrahexyloxy-7,8′-dicyano-di-p-phenylenevinylene) (CN-PPV) and poly(9,9′-dioctylfluorene-co-benzothiadiazole (F8BT); the carbon nanotube is a multi-walled carbon nanotube or a single-walled carbon nanotube, and the cross-sectional diameter of the carbon nanotube is smaller than 100 nm; and the semiconductor nanoparticle is one selected from the group consisting of titanium dioxide, cadmium selenide and cadmium sulfide.
In this preferred embodiment, the p-type semiconductor material is preferably P3HT, and the n-type semiconductor material is preferably PCBM, and the ratio by weight of P3HT and PCBM is 1:1, and they are mixed into a solution with a percentage by weight of 2%. In the meantime, the PEG of different molecular weights and P3HT have a specific ratio by weight. For example, the weight ratio of PEG and P3HT is 1:5˜1:5, and preferably 1:20.
After the semiconductor layer 22 is processed by a solvent annealing process for at least 2 hours, the semiconductor layer 22 is processed by a thermal annealing process at 110° C. for 15 minutes.
In FIG. 2B , a patterned first electrode 23 is provided, and the first electrode 23 is a transparent conductor or a semi-transparent conductor; the transparent conductor is made of indium tin oxide (ITO) or indium zinc oxide; the semi-transparent conductor is a metal thin film, and the metal thin film is made of a material selected from the group consisting of silver, aluminum, titanium, nickel, copper, gold, and chromium.
After the first electrode 23 is rinsed, a conductive polymer layer 24 is coated onto the first electrode 23 by a spin-coating process, and then the conductive polymer layer 24 and the first electrode 23 are baked dry at 120° C. for 60 minutes.
The electrically conductive polymer of the conductive polymer layer 24 is made of a material selected from the group consisting of 3,4-polyethylenedioxythiophene-polystyrenesulfonate (PEDOT:PSS), polyaniline, polypyrrole and polyacetylene. The additive is a surfactant, and the surfactant is poly(oxyethylene tridecyl ether). In this preferred embodiment, the conductive polymer layer 24 is preferably made of PEDOT: PSS.
In FIG. 2C , a transfer procedure takes place. Before the transfer, the conductive polymer layer 24 is heated at 110° C. for 5 minutes, and then the substrate 21 and the semiconductor layer 22 are placed on the conductive polymer layer 24 , and the semiconductor layer 22 is attached with the conductive polymer layer 24 . After the attachment, a uniform pressure is exerted onto a junction of the semiconductor layer 22 and the conductive polymer layer 24 as shown in FIG. 2D . A first adhesion is generated between the semiconductor layer 22 containing PEG of different molecular weights and the substrate 21 and a second adhesion is generated between the semiconductor layer 22 containing PEG of different molecular weights and the conductive polymer layer 24 .
Since the PEG is deposited at a position near the substrate 21 or the PEG is distributed on the contact surface with the substrate 21 , therefore the adhesion between the semiconductor layer 22 and the substrate 21 is weaker than the adhesion between the semiconductor layer 22 and the conductive polymer layer 24 . In other words, the strength of the second adhesion is greater than the strength of the first adhesion. The weaker adhesion between the semiconductor layer 22 and the substrate 21 causes a weaker binding.
Then, the substrate 21 is removed. Since the first adhesion is smaller than the second adhesion, therefore the semiconductor layer 22 will still be attached onto the conductive polymer layer 24 as shown in FIG. 2E to complete the transfer.
In FIG. 2F , after the semiconductor layer 22 is transferred, a thermal evaporation method is used to evaporate a second electrode 25 onto the semiconductor layer 22 to complete manufacturing of the solar cell 2 .
The second electrode 25 is a single-layer structure or a double-layer structure, and the single-layer structure is made of magnesium-gold alloy, and the double-layer structure is made of lithium/aluminum or calcium/aluminum.
With reference to FIG. 3 for a graph of voltage versus current density of a solar cell manufacturing by a transfer method and a spin-coating method of the semiconductor layer containing PEG and a coating method of a semiconductor layer of a solar cell without containing any PEG at 100 mW/cm 2 and with a standard solar energy simulated light of AM 1.5 G, the characteristics of solar cells manufactured by using the transfer method and using the spin-coating method are similar, and it shows that the method of the present invention can be used for manufacturing the solar cells successfully by the transfer method.
In addition, Table 1 shows the parameters of the solar cells manufactured by using a semiconductor layer containing PEG and a transfer method of (PEG600 (5%) (Transfer)), a spin-coating method of (PEG600 (5%) (Spin)), and using a semiconductor layer containing no PEG by a spin coating method of (P3HT and PCBM (Spin)).
Parameters of each component of the solar cell are defined first. With infinite load resistance of the solar cell, the voltage is called open circuit voltage (VOC) when the external current is disconnected (or the current is equal to zero). When the voltage is zero, the current density is called short circuit current density (JSC). In the graph of the current density versus the voltage of the solar cell, the output power (P) at any working point is equal to the product (P=V×J) of the corresponding voltage (V) and current density (J) of the working point, wherein one of the working points (Vm, Jm) has the maximum output power (Pm, Pm=Vm×Jm). The ratio of the maximum output power and the product of the open circuit voltage and the short circuit current density is defined as a filling factor (FF) and FF=(Vm×Jm)/(VOC×J SC)).
For solar cells with better component properties, the filling factor should be close to 1, in addition to the required high open circuit voltage and short circuit current density. The filling factor represents level of the maximum output power approaching the product of the open circuit voltage and close circuit current density. The power conversion efficiency (η=(V OC×J SC×FF)/P in) of the solar cell is defined as the ratio of the output power and the input light energy (P in), such that when the filling factor value is approaching to 1, the power conversion efficiency becomes increasingly higher.
TABLE 1
Power
Open circuit
Short circuit
conversion
Filling
voltage
current density
efficiency
Factor
VOC (V)
Jsc (mA/cm 2 )
η(%)
(FF)
P3HT and PCBM
0.47
8.21
2.02
0.52
(SPIN)
PEG600
0.51
9.47
2.25
0.47
(5%)(SPIN)
PEG600 (5%)
0.53
7.86
2.16
0.52
(TRANSFER)
From Table 1, the solar cell with the semiconductor layer containing no PEG has an open circuit voltage of 0.47V, a power conversion efficiency of 2.02%, and the solar cell with the semiconductor layer containing PEG and manufactured by the spin-coating method has an open circuit voltage increased to 0.51V, and a power conversion efficiency increased to 2.25%, and the solar cell with the semiconductor layer containing PEG and manufactured by the transfer method has an open-circuit voltage increased to 0.53V and a power conversion efficiency increased to 2.16%. Table 1 shows that the solar cell with the semiconductor layer containing PEG has a better function and effect than the solar cell with the semiconductor layer containing no PED, regardless of its manufacture by the spin-coating manufacturing process or the transfer manufacturing process.
With reference to FIG. 4 for a schematic view of a roll-to-roll manufacturing process of a solar cell in accordance with the present invention, the roll-to-roll manufacturing process replaces the process of coating a solution onto the substrate as shown in FIG. 2A .
In FIG. 4 , the roll-to-roll manufacturing process includes at least one roller 32 and a flexible substrate 31 , and further includes a solution 33 made by a p-type semiconductor material, an n-type semiconductor material and PEG. The surface of the roller 32 is made of a material similar to silicon dioxide, and with an appropriate pattern. When the surface of the roller 32 is rotating, the surface of the roller 32 is in contact with the solution 33 , such that the solution 33 is coated onto the flexible substrate 31 .
The roll-to-roll manufacturing process makes use of the characteristic of the weaker contact force between the organic material and the surface of the roller, the solution can be coated quickly and easily onto the flexible substrate, so as to simplify the manufacturing process and reduce the manufacturing time for an easier entry of a mass production.
The manufacturing method for an organic optoelectronic thin film in accordance with the present invention is not limited for the use of manufacturing solar cells only, but it can also be applied for manufacturing light emitting diodes, thin film transistors and flexible solar cells and modules.
The manufacturing method for an organic optoelectronic thin film in accordance with the present invention can achieve the effects of simplifying the manufacturing process and saving the trouble of manufacturing the PDMS print mold to achieve the same transfer effect. | Disclosed is a manufacturing method for an organic optoelectronic thin film comprising the steps of providing a substrate and a first electrode; forming a semiconductor layer on the substrate, wherein the semiconductor layer includes polyethylene glycol (PEG); forming a conductive polymer layer on the first electrode; disposing the substrate and the semiconductor layer on the conductive polymer layer and adhering the semiconductor layer to the conductive polymer layer; and removing the substrate; and forming a second electrode on the semiconductor layer. A first adhesion between the semiconductor layer and the substrate is generated. A second adhesion between the semiconductor layer and the conductive polymer layer is generated. The second adhesion is greater than the first adhesion so that while the substrate is removed, the semiconductor layer and the conductive polymer layer are still adhered. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority of U.S. provisional patent application Ser. No. 62/138,865 filed Mar. 26, 2015, which is incorporated by reference into this application in its entirety.
TECHNICAL FIELD
The present disclosure is related to the field of modular stops for valves, in particular, ball valves used in drill stem safety valves in a drill string.
BACKGROUND
Drill stem safety valves (“DSSV”) typically have two primary purposes: a) they are safety devices that can be closed to prevent mud and/or well fluid from flowing back up the interior of the drill pipe in the event of an unbalanced pressure in the mud column; and b) they can be used as a flow control device to turn on and off the flow of mud while making and breaking connections during drilling operations for top drives.
When used for blow out prevention, these valves are only used during testing or in emergencies. However, in mud control, they can be operated several hundred times in the drilling of a single well.
Drilling mud is an abrasive, highly engineered fluid that is used to balance pressure in the string against pressure in the pay zone upon point of penetration. The abrasiveness of the fluid is due to entrained solids such as sand. Well fluids are any hydrocarbons in the pay zone, and can include a mixture of oil, gas and solids.
To operate a DSSV, it is simply turned from the open to closed position and back again, by applying torque to the DSSV stem. This torque can be applied manually, or by an actuator. The stem in the valve is a part which penetrates the pressure envelope. It typically has a hexagonal interface to receive a wrench that can be used to open or close the valve.
The body of the valve is the part which houses all the internal parts. The body is typically constructed of high strength carbon steel alloy due to the extremely high pressure, torque and tension it is subjected to as part of the drill string. This type of alloy is selected for its strength, but as such is not very corrosion resistant and cannot be welded because welding introduces localized hardening that can cause premature failure under high loads.
Under pressure, the valve takes a significant amount of torque to operate. Some valves require upwards of 2000 foot-pounds (“ft-lbs”) to operate. This torque can be applied manually by wrench, or by actuator. Because of this, there is substantial load on the hexagonal stem, and conversely when the valve reaches its full travel, this load is transferred to the “valve stop”.
The stops in the valve are the contact areas between the stem and, typically, a stop ring or the body itself. The stops must have enough surface area to withstand the load applied either by wrench or by actuator. The ability of these stops to handle the loads applied is critical to proper function of the valves. If the stops are too weak, i.e. there is not enough “stopping power”, they will quickly yield under load. As the stops yield, they allow the ball to travel further and further from its optimal position in both the open and closed direction. This is referred to as “over travel”. Any over travel can have significant, negative effects on valve performance and life, and can result in infantile failure.
Currently, for any DSSV, the correct alignment of the ball in the open and closed position is critical to optimal valve life. Without correct alignment in the open position, the leading edge of the ball and the trailing edge of the lower seat will be exposed to abrasive mud flow, causing premature wear and potentially vortices that can accelerate erosion. The resulting deflected flow path and resulting accelerated erosion can lead to infantile failure.
There are several methods to ensure alignment of the ball in the open and closed positions. Early stop systems incorporated a “stop ring”. This ring is a removable ring on the interior of the valve exposed to the drilling fluid, usually adjacent to the upper seat, which provides a flat surface for the stem to come into contact with. Due to the nature and design of the ring, the amount of surface area available to stop against is typically very low. Because of the low amount of surface area, these stop rings cannot resist significant amounts of torque and therefore do not have much stopping power. After only a few uses, any yielding in the stop area will allow the ball to over travel in the open and closed direction. However, one advantage of using stop rings is that they are replaceable. Any yielding of the ring can easily be fixed by simply replacing the ring during regular service.
To improve stopping power, “cam style” stops were invented. These types of stops are typically used in higher pressure valves, and are typically single sided (as opposed to dual stops mentioned below). Typically, these types of stops comprise a cam lobe incorporated into the stem, which mates with a cam feature milled directly into the body. The utilization of a cam allows for much more surface area in the stop, resulting in more accurate, reliable and repeatable alignment under high torque applications. However, by incorporating or integrating the stop into the body itself, either by machining or fabricating the stop in the valve body, they are difficult to inspect, not very corrosion-resistant and non-repairable because they cannot be welded. If the body wears out, it must be replaced which shortens the useful life of the valve at great expense.
A recent innovation to cam style stops is the Dual Stop™ stem, as manufactured by Hi-Kalibre Equipment Limited of Edmonton, Alberta, Canada. In this design, the stem lobes are doubled, for double the stopping power. While this provides even further reliability and improved life in the field, these lobes are still difficult to inspect, not very corrosion resistant and when they eventually wear out, they cannot be repaired.
It is, therefore, desirable to provide a stop mechanism for DSSVs that overcomes the shortcomings of the prior art.
SUMMARY
A modular stop can be provided that incorporates the stops into a removable part. The stops can be integrated into a stem insert. The material of the stem insert can be made from more corrosion resistant alloys, to improve or lengthen the service life of the stop.
In some embodiments, the stops can be manufactured to be either single-sided, or dual-sided. In some embodiments, the modular stop can still comprise a cam and, thus, can provide as much stopping power as conventional cam style stems. In addition, they can have the same repeatability and reliability as the current state of the art.
In some embodiments, the modular stops can be easily removed for inspection or replacement. Replacement of a worn modular stop with a new modular stop can return the valve travel to normal as the wear is contained in the removable insert, which will eliminate replacement of the valve body due to integral stops being worn.
In some embodiments, existing prior art valves can be upgraded or retrofitted to incorporate the modular stop. By machining existing bodies to receive a modular stop, the modular stop can be incorporated into previously manufactured equipment, using the same stems and a new insert and, thus, extend the service life of the valve and improve the accuracy of its operation.
Broadly stated, in some embodiments, a modular stop can be provided for use in a valve, the valve comprising a tubular body and at least one opening disposed through a sidewall thereof, the at least one opening providing communication to a valve chamber disposed within an interior of the body, the at least one opening providing access to a stem configured for turning a ball valve disposed in the tubular body, the stem comprising a cylindrical portion comprising a longitudinal axis extending therethrough, and a cam plate disposed on one end of the cylindrical portion wherein the cam plate is substantially perpendicular to the longitudinal axis, the cam plate comprising at least one cam lobe, the body further comprising a first relief disposed around the at least one opening in the interior adjacent to the valve chamber, the modular stop comprising: a tubular neck portion comprising a first end and a second end, the first end configured for slidable fit into the at least one opening when inserted therein, the tubular neck portion defining a first passageway between the first and second ends, the first passageway configured for slidable fit with the cylindrical portion of the stem when the cylindrical portion is inserted therein; and a base portion disposed on the second end, the base portion larger in diameter than the tubular neck portion, the base portion configured for insertion into the first relief when the tubular neck portion is inserted into the at least one opening, the base portion comprising a second relief configured for receiving the cam plate when the cylindrical portion is inserted into the first passageway, the second relief further comprising at least one stop configured for contacting the at least one cam lobe wherein the stem is limited to approximately 90 degrees of rotational movement about the longitudinal axis when inserted into the modular stop.
Broadly stated, in some embodiments, a valve can be provided for use with a drill string, the valve comprising a tubular body and at least one opening disposed through a sidewall thereof, the at least one opening providing communication to a valve chamber disposed within an interior of the tubular body, the at least one opening providing access to a stem configured for turning a ball valve disposed in the body, the stem comprising a cylindrical portion comprising a longitudinal axis extending therethrough, and a cam plate disposed on one end of the cylindrical portion wherein the cam plate is substantially perpendicular to the longitudinal axis, the cam plate comprising at least one cam lobe, the body further comprising a first relief disposed around the at least one opening in the interior adjacent to the valve chamber, the valve comprising a modular stop further comprising: a tubular neck portion comprising a first end and a second end, the first end configured for slidable fit into the at least one opening when inserted therein, the tubular neck portion defining a first passageway between the first and second ends, the first passageway configured for slidable fit with the cylindrical portion of the stem when the cylindrical portion is inserted therein; and the modular stop further comprising a base portion disposed on the second end, the base portion larger in diameter than the tubular neck portion, the base portion configured for insertion into the first relief when the tubular neck portion is inserted into the at least one opening, the base portion comprising a second relief configured for receiving the cam plate when the cylindrical portion is inserted into the first passageway, the second relief further comprising at least one stop configured for contacting the at least one cam lobe wherein the stem is limited to approximately 90 degrees of rotational movement about the longitudinal axis when inserted into the modular stop.
Broadly stated, in some embodiments, the modular stop can further comprise a seal disposed between it and the tubular body.
Broadly stated, in some embodiments, the second relief can comprise a first stop and a second stop to define the start and stop of the rotational movement.
Broadly stated, in some embodiments, the modular stop can further comprise means for preventing rotation of the base portion when inserted into the first relief.
Broadly stated, in some embodiments, the means can comprise the base portion comprising a cross-sectional shape that is non-circular, wherein the first relief is configured to receive the base portion wherein the modular stop cannot substantially rotate when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, the rotation preventing means can comprise an interference fit between the base portion and the body when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, the rotation preventing means can comprise complimentary splines disposed on the base portion and in the first relief wherein the complimentary splines mesh with each other when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, the rotation preventing means can comprise at least one pin disposed between the body and the base portion wherein the modular stop cannot substantially rotate when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, a method can be provided for manufacturing a valve for use with a modular stop wherein the valve comprises a tubular body and at least one opening disposed through a sidewall thereof, the at least one opening providing communication to a valve chamber disposed within an interior of the tubular body, the at least one opening providing access to a stem configured for turning a ball valve disposed in the body, the stem comprising a cylindrical portion comprising a longitudinal axis extending therethrough, and a cam plate disposed on one end of the cylindrical portion wherein the cam plate is substantially perpendicular to the longitudinal axis, the cam plate comprising at least one cam lobe, the method comprising the steps of: fabricating a first relief disposed around the at least one opening in the interior adjacent to the valve chamber; providing a modular stop, further comprising: a tubular neck portion comprising a first end and a second end, the first end configured for slidable fit into the at least one opening when inserted therein, the tubular neck portion defining a first passageway between the first and second ends, the first passageway configured for slidable fit with the cylindrical portion of the stem when the cylindrical portion is inserted therein, and a base portion disposed on the second end, the base portion larger in diameter than the tubular neck portion, the base portion configured for insertion into the first relief when the tubular neck portion is inserted into the at least one opening, the base portion comprising a second relief configured for receiving the cam plate when the cylindrical portion is inserted into the first passageway, the second relief further comprising at least one stop configured for contacting the at least one cam lobe wherein the stem is limited to approximately 90 degrees of rotational movement about the longitudinal axis when inserted into the modular stop; inserting the tubular neck portion into the at least one opening, wherein the base portion is substantially seated in the first relief; and inserting the cylindrical portion into the first passageway, wherein the cam plate is substantially disposed in the second relief.
Broadly stated, in some embodiments, a method can be provided for retrofitting an existing valve for use with a modular stop wherein the valve comprises a tubular body and at least one opening disposed through a sidewall thereof, the at least one opening providing communication to a valve chamber disposed within an interior of the tubular body, the at least one opening providing access to a stem configured for turning a ball valve disposed in the body, the stem comprising a cylindrical portion comprising a longitudinal axis extending therethrough, and a cam plate disposed on one end of the cylindrical portion wherein the cam plate is substantially perpendicular to the longitudinal axis, the cam plate comprising at least one cam lobe, the method comprising the steps of: fabricating a first relief disposed around the at least one opening in the interior adjacent to the valve chamber; providing a modular stop, further comprising: a tubular neck portion comprising a first end and a second end, the first end configured for slidable fit into the at least one opening when inserted therein, the tubular neck portion defining a first passageway between the first and second ends, the first passageway configured for slidable fit with the cylindrical portion of the stem when the cylindrical portion is inserted therein, and a base portion disposed on the second end, the base portion larger in diameter than the tubular neck portion, the base portion configured for insertion into the first relief when the tubular neck portion is inserted into the at least one opening, the base portion comprising a second relief configured for receiving the cam plate when the cylindrical portion is inserted into the first passageway, the second relief further comprising at least one stop configured for contacting the at least one cam lobe wherein the stem is limited to approximately 90 degrees of rotational movement about the longitudinal axis when inserted into the modular stop; inserting the tubular neck portion into the at least one opening, wherein the base portion is substantially seated in the first relief; and inserting the cylindrical portion into the first passageway, wherein the cam plate is substantially disposed in the second relief.
Broadly stated, in some embodiments, the methods can further comprise the step of fabricating at least one O-ring groove disposed around the tubular neck portion and installing an O-ring into the at least one O-ring groove prior to inserting the tubular neck portion into the at least one opening.
Broadly stated, in some embodiments, the methods can further comprise the step of fabricating a first stop and a second stop in the second relief, to define the start and stop of the rotational movement, prior to seating the base portion in the first relief.
Broadly stated, in some embodiments, the methods can further comprise the step of providing means for preventing rotation of the base portion when inserted into the first relief.
Broadly stated, in some embodiments, the methods can further comprise the steps of: fabricating the base portion to comprise a cross-sectional shape that is non-circular; and fabricating the first relief to receive the base portion wherein the modular stop cannot substantially rotate when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, the methods can further comprise the step of fabricating the base portion such that there is an interference fit between the base portion and the first relief when the base portion is inserted into first relief.
Broadly stated, in some embodiments, the methods can further comprise the step of fabricating complimentary splines disposed on the base portion and in the first relief wherein the complimentary splines mesh with each other when the base portion is inserted into the first relief.
Broadly stated, in some embodiments, the methods can further comprise the step of providing a pin disposed between the body and the base portion wherein the modular stop cannot substantially rotate when the base portion is inserted into the first relief.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side elevation view depicting a ball valve comprising modular stops.
FIG. 2 is a front elevation view depicting one embodiment of a modular stop comprising a single-sided stop.
FIG. 3 is a side elevation view depicting the modular stop of FIG. 2 .
FIG. 4 is a bottom plan view depicting the modular stop of FIG. 2 .
FIG. 5 is a perspective view depicting the modular stop of FIG. 2 .
FIG. 6 is a front elevation view depicting another embodiment of a modular stop comprising a dual-sided stop.
FIG. 7 is side elevation view depicting the modular stop of FIG. 6 .
FIG. 8 is a bottom plan view depicting the modular stop of FIG. 6 .
FIG. 9 is a perspective view depicting the modular stop of FIG. 6 .
FIG. 10 is a cross-sectional side elevation view depicting a valve comprising the modular stop of FIG. 2 .
FIG. 11 is a cross-sectional side elevation view depicting a valve comprising the modular stop of FIG. 6 .
DETAILED DESCRIPTION OF EMBODIMENTS
Referring to FIG. 1 , one embodiment of modular stops 10 are shown installed in valve 11 . In some embodiments, modular stop 10 can be inserted into opening 30 disposed through sidewall 31 of tubular valve body 32 , wherein base portion 36 of modular 10 can seat in relief 58 disposed in sidewall 31 . In some embodiments, stem 12 can be disposed in passageway 48 disposed through modular stop 10 .
In some embodiments, stem 12 can be mechanically connected to ball valve 18 via u-joint 16 , which can be position in valve chamber 28 and held in position by lower ball seat 20 and upper ball seat 22 , which can be further held in position by split ring 24 and lock ring 26 . In some embodiments, u-joint 16 can comprise key 17 that can fit into key slot 19 of ball valve 18 . Similarly, u-joint 16 can comprise another key (not shown) configured to fit into a corresponding key slot 56 (as shown in FIG. 8 ) as well known to those skilled in the art, wherein ball valve 18 can be rotated to close valve 11 by inserting a hex wrench (not shown) into hex opening 14 and rotating the hex wrench approximately 90 degrees to close off passageway 15 extending through valve body 32 .
Referring to FIGS. 2 to 5 , one embodiment of modular stop 10 is shown, wherein this embodiment can comprise a singular or single-sided stop. In this embodiment, modular stop 10 can comprise neck portion 34 and base portion 36 , which can be larger in diameter than neck portion 34 . In some embodiments, modular stop 10 can comprise a seal placed between it and valve body 32 and/or relief 58 to provide means to prevent produced substances, such as fluids and gases from passing through opening 30 when modular stop 10 is installed therein. In some embodiments, this seal can comprise neck portion 34 comprising at least one O-ring groove 38 disposed therearound to receive an O-ring (not shown), as well known to those skilled in the art, to provide sealing means when neck portion 34 is inserted into opening 30 of valve body 32 . Stem 12 can comprise cylindrical portion 13 , which can be configured to be inserted into passageway 48 disposed through neck portion 34 . In some embodiments, stem 12 can comprise key 52 extending outwardly from cam plate 40 , which can serve as means to engage key slot 19 on ball valve 18 without the need of u-joint 16 . In some embodiments, base portion 36 can comprise cam profile or relief 44 , which can be configured to receive cam plate 40 . In this embodiment, cam plate 40 can comprise a single cam lobe 42 , which can be configured to contact stops 46 when stem 12 is rotated approximately through 90 degrees of rotation about longitudinal axis 60 from one stop 46 to the other stop 46 . As shown in FIG. 4 , stem 12 can rotate in a clockwise direction from contacting right-hand stop 46 to left-hand stop 46 , which represents approximately 90 degrees of rotation about longitudinal axis 60 . In some embodiments, to prevent modular stop 10 from rotating when inserted into relief 58 disposed in valve chamber 28 of valve body 32 , base portion 36 can comprise a cross-sectional shape that is non-circular, as represented by reference numeral 50 , that can be inserted into relief 58 , wherein relief 58 can be configured to receive cross-sectional shape 50 of base portion 36 and prevent the rotation thereof about longitudinal axis 60 .
Referring to FIGS. 6 to 9 , another embodiment of modular stop 10 is shown, wherein this embodiment can comprise a dual or double-sided stop. In this embodiment, modular stop 10 can comprise neck portion 34 and base portion 36 , which can be larger in diameter than neck portion 34 . In some embodiments, modular stop 10 can comprise a seal placed between it and valve body 32 and/or relief 58 to provide means to prevent produced substances, such as fluids and gases from passing through opening 30 when modular stop 10 is installed therein. In some embodiments, this seal can comprise neck portion 34 comprising at least one O-ring groove 38 disposed therearound to receive an O-ring (not shown), as well known to those skilled in the art, to provide sealing means when neck portion 34 is inserted into opening 30 of valve body 32 . Stem 12 can comprise cylindrical portion 13 , which can be configured to be inserted into passageway 48 disposed through neck portion 34 . In some embodiments, stem 12 can comprise key slot 56 extending across cam plate 40 , which can serve as means to engage u-joint 16 that, in turn, can engage key slot 19 on ball valve 18 , as shown in FIG. 1 . In some embodiments, base portion 36 can comprise cam profile or relief 44 , which can be configured to receive cam plate 40 . In this embodiment, cam plate 40 can comprise two cam lobes 42 , which can be placed diagonally opposed to each other across cam plate 40 , as shown in FIG. 8 . In some embodiments, cam lobes 42 can be configured to contact stops 46 when stem 12 is rotated approximately through 90 degrees of rotation about longitudinal axis 60 from one stop 46 to the other stop 46 . As shown in FIG. 8 , stem 12 can rotate in a clockwise direction from contacting stops 46 located on the upper right and lower left of FIG. 8 , to stops 46 located on the upper left and lower right, wherein the rotation represents approximately 90 degrees of rotation about longitudinal axis 60 . In some embodiments, to prevent modular stop 10 from rotating when inserted into relief 58 disposed in valve chamber 28 of valve body 32 , base portion 36 can comprise a cross-sectional shape that is non-circular, as represented by reference numeral 50 , that can be inserted into relief 58 , wherein relief 58 can be configured to receive cross-sectional shape 50 of base portion 36 and prevent the rotation thereof about longitudinal axis 60 .
In some embodiments, the non-circular cross-sectional shape of base portion 36 can represent means for preventing the rotation of modular stop 10 when inserted into relief 58 . In some embodiments, the rotation prevention means can comprise an interference fit between base portion 36 and relief 58 when modular stop 10 is inserted into relief 58 . In other embodiments, the rotation prevention means can comprise complimentary splines disposed about base portion 36 and in relief 58 , as well known to those skilled in the art, wherein the complimentary splines engage each other when base portion 36 is inserted into relief 58 . In other embodiments, the rotation prevention means can comprise at least one pin disposed between modular stop 10 and valve body 32 when base portion 36 is inserted into relief 58 , wherein the at least one pin is configured to engage both modular stop 10 and valve body 32 and prevent the rotation of modular stop 10 about longitudinal axis 60 .
Referring to FIG. 10 , an illustration of a single-sided modular stop 10 installed in relief 58 of valve body 32 is provided. As shown in FIG. 10 , stem 12 can rotate in a counter-clockwise direction from contacting upper stop 46 to lower stop 46 , wherein the rotation represents approximately 90 degrees of rotation about longitudinal axis 60 , and wherein key 52 would move from a substantially horizontal orientation to a substantially vertical orientation.
Referring to FIG. 11 , an illustration of a double-sided modular stop 10 installed in relief 58 of valve body 32 is provided. As shown in FIG. 11 , stem 12 can rotate in a counter-clockwise direction from contacting stops 46 located on the upper left and lower right of FIG. 11 , to stops 46 located on the upper right and lower right, wherein the rotation represents approximately 90 degrees of rotation about longitudinal axis 60 , and wherein key slot 56 would move from a substantially horizontal orientation to a substantially vertical orientation.
In some embodiments, modular stop 10 can be comprised of bronze, as well as other wear-resistant materials, such as copper alloys, stainless steel, monel and iconel as well known to those skilled in the art. In so doing, modular stop 10 can be manufactured of materials that have better wear characteristics than the high strength carbon steel used in the manufacture of valve body 32 . In some embodiments, stem 12 can be comprised of 17-4 stainless steel, as well as other wear-resistant materials, such as copper alloys, bronze alloys, monel and iconel as well known to those skilled in the art.
Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications can be made to these embodiments without changing or departing from their scope, intent or functionality. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the invention is defined and limited only by the claims that follow. | A modular stop is provided for ball valves, such as those used as drill stem safety valves. The modular stop can be a replaceable component in valves for use with stems used to rotate a ball valve in the valve's body. The modular stop can bear the wear associated with the operation of ball valves and when the modular stop has exceeded its usable service life, it can be replaced without replacing the whole of the valve body. The modular stop can be used in new valve manufacture as well as in the retrofitting or remanufacturing of existing valves. | 5 |
This is a Continuation-In-Part of U.S. patent Ser. No. 08/986,852 filed Dec. 8, 1997 titled TRASH CONTAINER LIFTING AND TRANSPORTING DEVICE invented by Robert L. Cummins now U.S. Pat. No. 6,033,178.
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates generally to lifting devices and, more particularly, to an apparatus for lifting and transporting a standard residential trash container.
Portable refuse containers or trashcans are a well known fixture of modern residential life. Every homeowner is familiar with the weekly chore of transporting the trashcan to the curbside for pickup by the trash disposal service. This presents a difficult problem for the homeowner whose residence is a substantial distance from the curb.
Although many trash disposal services provide a wheeled container for this purpose, it remains a cumbersome task when the full container must be maneuvered for a substantial distance.
Thus, the present invention has been developed to provide a trash can lifting device which can be conveniently attached to a motor vehicle for transporting a trash container to the curb for pickup.
2. Description of Related Prior Art
U.S. Pat. No. 3,740,097 to Shirley L. Parker et al. discloses a vehicle dump bed for vehicles such as a pickup truck which can be easily mounted on and removed from the vehicle bed. The dump bed is provided with fixtures for lifting a refuse container as the bed is lowered and for transporting the container from one place to another.
U.S. Pat. No. 3,376,986 to H. Farber discloses a detachable garbage can carrier comprising a fixture that is adapted for engaging the handles of a standard cylindrical trash can. The detachable carrier can be mounted on any suitable cart such as a two-wheel shopping cart for transporting the trashcan to the curbside.
U.S. Pat. No. 4,944,434 to Kenneth B. Hamilton discloses an automobile portable hauler for transporting supplies and equipment on the exterior of a conventional motor vehicle. The portable hauler uses brackets that are adapted to fit over the door of the vehicle when the window is open and in a down position.
U.S. Pat. No. 4,298,151 to Brian J. O'Connor discloses a carrier rack for mounting and carrying bicycles on a motor vehicle which includes structures for clamping the rack between the trunk and trunk lid or between some other opening in the automobile and a closure appending to that opening.
U.S. Pat. No. 2,338,955 to Hollis H. Metcalf discloses an automobile carrier adapted for mounting on the rear bumper and trunk of a vehicle which can be positioned to carry various loads thereon.
U.S. Pat. No. 2,409,103 to J.C.A. Cameron discloses an automobile luggage carrier including fixtures for clamping the carrier to the rear bumper and window frame of the vehicle. However, no lifting mechanism is disclosed in this patent.
U.S. Pat. No. 2,663,474 to Edward J. Kelly discloses an outboard motor carrier including fixtures for clamping the carrier between the trunk and trunk lid of a motor vehicle. However, no lifting mechanism is disclosed in this patent.
U.S. Pat. No. 4,252,492 to Clinton Y. Scothern discloses a detachable lift unit for pickup trucks wherein the lifting is readily attached to and detached from the end of the bed of a pickup truck without the use of tools or other apparatus.
Finally, U.S. Pat. No. 5,221,173 to Kevin P. Barnes discloses a multi-vehicle transport system for bulk materials including a primary vehicle operable to go to remote areas and discharge the contents of a standard bin into a hopper, and a secondary load vehicle operable using a hydraulically actuated forklift system to lift and discharge the contents of the hopper from the primary load vehicle into the secondary load vehicle.
SUMMARY OF THE INVENTION
After much research and study of the above described problem, the present invention has been developed to provide a trash container lifting device which can be mounted on the tailgate of a standard pickup truck to engage and lift the trash container for transport by the vehicle.
The lifting device is supported by a pair of J-shaped members which are hung over the tailgate of the pickup truck without the use of tools or other apparatus. The lifting mechanism comprises an articulating frame that pivots downwardly to engage the trash container on the ground and upwardly to lift the container for transport.
The reciprocal lifting movement is accomplished by an elongated handle extending between the support frame and the articulating frame and is assisted by heavy-duty extension springs which provide a mechanical advantage in lifting the load.
In view of the above, it is an object of the present invention to provide a trash container lifting device which will provide a homeowner with a convenient means of lifting and transporting a trash container which could not otherwise be lifted by a single individual.
Another object of the present invention is to provide a trash container lifting device which may be conveniently mounted on a motor vehicle such as a pickup truck without the use of tools or other apparatus.
Another object of the present invention is to provide a trash container lifting device which utilizes a plurality of heavy-duty extension springs to gain a mechanical advantage in lifting the trash container.
Another object of the present invention is to provide a trash container lifting device which is adaptable for use with various standard sized trash containers.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1. is a perspective view of the trash container lifting device of the present invention shown mounted on the tailgate of a pickup truck;
FIG. 2. is a an enlarged perspective view of the trashcan lifting device showing the lifting mechanism in disengaged relationship to a trash container;
FIG. 3. is a side elevational view of the trash container lifting device engaging a trash container on the ground surface; and
FIG. 4. is a side elevational view of the trash container lifting device shown in a raised position after lifting the trash container off the ground surface;
FIG. 5 is a perspective view of a modified trash container lifting device mounted on a receiver type trailer hitch;
FIG. 6 is a side elevational view showing the modified lifting mechanism engaging a trash container; and
FIG. 7 is a side elevational view showing the trash container lifted by the modified lifting mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With further reference to the drawings, there is shown therein a trash container lifting device in accordance with the present invention, indicated generally at 10 and illustrated in FIG. 1. The lifting device 10 is shown installed on the tailgate 32 at the rear end of a pickup truck, indicated generally at 30, in phantom outline.
In the preferred embodiment, the lifting device 10 is comprised of a supporting frame, indicated generally at 16; an articulating frame, indicated generally at 20; a pair of extension springs 25 and a hand lever indicated generally at 28.
The supporting frame 16 includes a pair of inverted J-shaped members 14 and 15 secured in generally parallel relation by cross members 12 and 13 extending therebetween and being fixedly attached thereto by weldment or attaching hardware.
Each of the J-shaped members 14 and 15 are comprised of a long leg member 14a and 15a, a short leg member 14b and 15b, and a stop member 14c and 15c respectively.
In the preferred embodiment the J-shaped members 14 and 15 are fabricated from rectangular tubing such as steel, aluminum or other suitable material and the component members thereof are joined together by welding.
The short leg members 14b and 15b are fabricated to a predetermined length such that the long leg members 14a and 15a are disposed in generally vertical relation to the ground surface when the supporting frame 16 is positioned over the tailgate 32 of the pickup truck 30 as shown in FIG. 1.
The articulating frame 20 is generally rectangular and comprised of a pair of vertically opposed, tilting brackets 18 and 19 which are interconnected by the upper and lower lift brackets 21 and 22 extending transversely therebetween and being fixedly attached thereto by weldment or attaching hardware.
In the present invention the articulating frame 20 is adapted for reciprocal upward/downward movement in a plane generally parallel to that plane defined by the supporting frame 16 in order to lift a trash container 40 of the type depicted in phantom outline in FIGS. 3 and 4.
The lifting mechanism of the present invention will now be described in detail. The articulating frame 20 is mechanically coupled to the supporting frame 16 by a pair of upper arm brackets 23 and 24 and a pair of lower arm brackets 26 and 27 respectively as illustrated in FIG. 1. More particularly, the upper arm bracket 23 and the lower arm bracket 26 are pivotally attached at one end thereof to the long member 14a of J-shaped member 14 by machine bolts 29 which are inserted through coaxial pivot holes (not shown) formed therein.
The opposite ends of the upper arm bracket 23 and the lower arm bracket 26 are also pivotally attached to the tilting bracket 18 by use of machine bolts 29 extending through coaxial pivot holes (not shown) formed therein.
In similar fashion, the upper arm bracket 24 and the lower arm bracket 27 are pivotally attached at one end thereof to the long member 15a of J-shaped member 15 by the use of machine bolts 29 which extend through coaxial pivot holes (not shown) formed therein.
Similarly, the opposite ends of upper arm bracket 24 and lower arm bracket 27 are pivotally attached to the tilting bracket 19 by the use of machine bolts 29 which extend through coaxial pivot holes (not shown) formed therein.
Of course, other suitable attaching hardware may be utilized to secure the articulating frame 20 to the supporting frame 16 and the embodiment described hereinabove is merely illustrative and is not intended to be restrictive in any sense.
It will be noted that an elongated hand lever 28 is provided which consists of a long member 28a and short member 28b as more clearly shown in FIG. 2. In the preferred embodiment the hand lever 28 is also fabricated from a generally rectangular tubing fabricated from steel, aluminum, or other suitable material.
It will be noted that the long member 28a and the short member 28b are joined at a predetermined angle A to provide the optimal lifting leverage to a user of the lifting device 10.
As shown in FIGS. 1 and 2, the short member 28b of the hand lever 28 is pivotally attached in parallel relation to the upper arm bracket 24 by machine bolts 29. In this arrangement it will be appreciated that upward/downward movement of hand lever 28 by a user will produce a corresponding movement of the articulating frame 20 critical to the present invention.
In the preferred embodiment a pair of coiled extension springs 25 are attached at one end thereof to the upper cross member 12 and at an opposite end thereof to the lower lift bracket 22 using suitable attaching hardware.
It will be appreciated by those skilled in the art that the extension springs 25 are fabricated to a predetermined load capacity and overall length to provide a user with the maximum lifting capability during use of the present lifting device.
Since such extension springs are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary.
Still referring to FIG. 1 it can be seen that each of the upper and lower lift brackets 21 and 22 is provided with a foot bracket 33 and 34 respectively which projects outwardly in generally perpendicular relation thereto. In the preferred embodiment each of the foot brackets 33 and 34 are fabricated from a generally rectangular plate of a metal material. Each foot bracket may include a bead or lip as at 33a formed along a forward edge thereof which functions to engage a recessed portion 39 of the trash container 40 as shown in FIG. 2.
Thus, in practical use of the present invention, a user will initially position the lifting device 10 over the tailgate 32 of a pickup truck or other similar vehicle such that the stop members 14c and 15c engage the tailgate 32 and support the lifting device 10 in the position shown.
Next, a trash container 40 is maneuvered into position in proximity to the foot bracket 33 as shown in FIG. 2. It will be appreciated that the box-shaped trash container 40 illustrated in the drawings is of a type often utilized in residential trash disposal service having a capacity ranging from 30 to 95 gallons.
Of course, the lifting device 10 can be adapted to fit various types of trash containers such as cylindrical containers (not shown) with minor modification to the foot brackets 33 and 34.
Such modifications to fit specific trash containers are considered to be within the scope and intended purpose of the present invention.
Next, in the preferred arrangement the user will push downwardly on the hand lever 28 to position the foot bracket 33 at the appropriate vertical height to engage the recess 39 or other mating feature of the trash container 40 as shown in FIG. 3. It will be appreciated by those skilled in the art that in this position the springs 25 are extended and placed under maximum tension by the downward force against the hand lever 28.
Thereafter, the user will push the hand lever 28 upwardly as shown by the directional indicator 36 using manual arm strength in combination with the contraction of springs 25 to raise the trash container 40 to the position illustrated in FIG. 4.
In the embodiment illustrated in FIGS. 3 and 4, it can be seen that the upper foot bracket 33 bears the load of the trash container 40 as the lower foot bracket 34 functions to guide and steady the trash container as it is lifted into position.
Once the trash container 40 has been lifted to the position shown in FIG. 4, a latch 38 is utilized to engage the hand lever 28 to secure it in position. In the preferred embodiment latch 38 is comprised of an elongated steel bar that is pivotally attached to the short member 15b of J-shaped member 15 by a machine bolt 29 extending through coaxial pivot holes (not shown) formed therein.
Latch 38 includes a U-shaped notch 39 formed therein which engages a latch pin 37 projecting from the hand lever 28 in a predetermined position. In this arrangement the latch 38 engages and holds the hand lever 28 supporting the trash container 40 in the raised position shown in FIG. 4.
In the position shown in FIG. 4, the trash container 40 may be conveniently transported by the vehicle to the curbside location for pickup. The user will release the latch 38 and lower the trash container 40 to the ground surface controlling the weight of the load manually with the assistance of the spring resistance provided by the springs 25.
Thereafter, the trash container 40 is easily disengaged from the upper foot bracket 33 and returned to the latched condition shown in FIG. 4 until needed.
In the alternative, the lifting device 10 can be simply removed from the tailgate 32 and placed in the bed of the pickup truck or elsewhere for future use.
Receiver type trailer hitches are well known to those skilled in the art and sometimes are referred to as the Reese® Hitch. A connector having the trailer hitch ball mounted on one end slides into the receiver and a quick-release pin holds the two parts together. By simply pulling the pin, the connector can be removed.
The modified trash container lifting device, indicated generally at 10' includes a hitch connector 50 adapted to slide into the trailer hitch receiver 51. This receiver type trailer hitch is well known to those skilled in the art, and further detailed discussion of the same is not deemed necessary.
On the outer end of the connector 50 is a vertical sleeve 52 secured thereto by weldment or other suitable means.
Aligned openings are provided in the sleeve 52 and are adapted to receive a quick-release pin 53. Since quick-release pins and the use of the same are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary.
A vertical member 54 is adapted to slidingly mount in vertical sleeve 52. A series of aligned openings 55 are provided in vertical member 54 and are adapted to receive the quick-release pin passing through the vertical sleeve 52. Thus it can be seen that the height of the vertical member above the vertical sleeve can be incrementally adjusted.
In the mid portion of the vertical member 54 is a T-shaped trash container engaging bracket 56 secured to such member and rearwardly projecting therefrom. The outer end of the horizontal portion 56' of bracket 56 has a trash container engaging pad 57 attached thereto.
The depending portion 56" of T bracket 56 is adapted to also engage the exterior of the trash container 40' as can clearly be seen in FIGS. 6 and 7.
A U-shaped arm 58 straddles the vertical member 54 and is pivotally mounted thereon as indicated at 59. A counter-balance spring 25' is connected to and extends between the central portion of U-shaped arm 58 and vertical member 54 as clearly seen in FIGS. 6 and 7. Since counter-balance springs are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary.
An upper opening 60 and lower opening 61 are provided above and below pivot 59. A locking pin 62 is mounted on one side of the U-shaped arm 58 and passes therethrough for engagement within the upper or lower lock opening 60 and 61. Locking pin 62 includes a spring 63 which biases said locking pin toward locking engagement with the respective upper and lower openings 60 and 61. Thus it can be seen that the pivoting relationship of the U-shaped arm can be locked either in the down position shown in FIG. 6 for loading of the trash container 40' or can be locked in the carrying position shown in FIG. 7 as will hereinafter be described in greater detail.
A pull cable 64 is connected to the outer end of locking pin 62 and terminates in a pull loop 65. The operation of a locking pin and pull cable will hereinafter be described in greater detail.
One end of an L-shaped arm 66 is fixedly mounted on U-shaped arm 58 as clearly seen in FIG. 5. The opposite end of arm 66 has an outwardly projecting handle 67 mounted thereon. The leg of arm 66 that mounts handle 67 has an opening in the same adjacent the juncture of the legs of such arm with pull cable 64 passing therethrough with pull loop 65 being disposed on the outside thereof, again as clearly seen in FIG. 5. On the open end of the U-shaped arm 58 is an L-shaped-in-cross-section lift bracket 33' fixedly secured thereto. This lift bracket is adapted to engage the notch 39' in the trash container 40' as hereinabove described in conjunction with lifting device 10.
To use the modified trash container lifting device 10' of the present invention, the handle 67 is used to move the L-shaped arm to the position shown in FIGS. 5 and 6 and the pull cable is manipulated so that locking pin 62 is in engagement with lower opening 61 in vertical member 54 with biasing spring 63 holding the locking pin in place.
The trash container 40' is wheeled up to the lift device 10' with the notch 39' of such container coming to engagement with lift bracket 33'. The locking pin 62 is pulled out of engagement with opening 61 in vertical member 54 by pulling loop 65 of cable 64. Handle 67 is then used, through L-shaped arm 66 and counter-balance spring 25', to pivot the lift bracket 33' connected to U-shaped arm 58, from the position shown in FIG. 6 to the position shown in FIG. 7 with locking pin 63 in alignment with opening 60 in vertical member 54. Pressure is then released on pull cable 64 which allows biasing spring 63 to push locking pin 62 into locking engagement with said opening 60.
In this position, the trash container 40' has adequate ground clearance to allow transport by vehicle 30' to the pickup location as hereinabove described for lift 10.
From the above it can be seen that the trash can lifting device of the present invention provides the user with a tool for lifting and transporting a residential trash container over substantial distances to the curbside for pickup.
The trash container lifting device provides the homeowner with a mechanical advantage in lifting a heavy trash container which would otherwise be an unmanageable load for a single person.
The trash container lifting device can be adapted for use with various residential and commercial trash containers which are available in different sizes and configurations.
The terms "upper", "lower", "side", and so forth have been used herein merely for convenience to describe the present invention and its parts as oriented in the drawings. It is to be understood, however, that these terms are in no way limiting to the invention since such invention may obviously be disposed in different orientations when in use.
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of such invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | A trash container lifting device adapted for attachment to a motor vehicle for lifting and transporting a filled trash container to a remote site for pickup is disclosed. The lifting device includes a supporting frame which is attached to the motor vehicle, such as a pickup truck, sport utility vehicle or the like without tools or attaching hardware. The supporting frame is mechanically coupled to an articulating frame for engaging a trash container on the ground surface and lifting it with a manual lever to a raised position for transport by the vehicle. At least one spring extends between the supporting frame and the articulating frame to provide the user with a mechanical advantage in lifting a loaded container which would otherwise be an unmanageable task for a single individual. The lifting device is adaptable to trash containers of various sizes and configurations with minor modifications. | 1 |
[0001] This U.S. Patent application is a Continuation of U.S. patent application Ser. No. 12/908,100 filed on Oct. 20, 2010, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to program debuggers, and more specifically to a program debugger that provides remote watch and modify features by providing a registration facility.
[0004] 2. Description of Related Art
[0005] Debuggers are used in both development and field environments to determine if program code is operating properly, and to investigate faults that cause improper program behavior that is apparent, such as non-terminating behavior. Debuggers generally provide views of the various aspects of internal program function and structure, such as traces of program execution path and views of program variables, in addition to hardware observation capabilities such as register and memory value snooping.
[0006] In order to provide the capabilities pointed out above, development systems typically provide the program developer with the capability of generating a debugging version of program code, which contains information allowing a debugging program to determine symbolic links to the program code and data storage areas. The symbol information may be embedded in the debug version of the program, or may be stored in one or more external files. A non-debug version of the program code is typically devoid of symbolic information.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention is embodied in a method, computer system and computer program product that provide for observing data values within storage locations of a computer program during execution of the computer program within the computer system. The method is a method of operation of the computer system and the computer program product is a set of program instructions embodied in tangible form in computer readable storage media such as optical, magnetic or electrical removable or non-removable memory.
[0008] The computer program registers individual storage locations that store the data values with a debugging module located in the same address space as the computer program. The debugging module receives requests from an external program that specify data values corresponding to storage locations that have been registered by the registering. In response to the requests, the debugging module retrieves or modifies the particular data values and for read requests, sends the particular data values from the debugging module to the external program, where the data values are displayed.
[0009] The foregoing and other objectives, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiment of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of the invention when read in conjunction with the accompanying Figures, wherein like reference numerals indicate like components, and:
[0011] FIG. 1 is a block diagram illustrating a processing system in which program code according to an embodiment of the present invention is generated and executed.
[0012] FIG. 2 is a memory diagram illustrating program code and data organization in accordance with an embodiment of the present invention.
[0013] FIG. 3 is a flow chart depicting a method in accordance with an embodiment of the present invention.
[0014] FIG. 4 is a flow chart depicting a method in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention relates to methods and programs that provide remote debugging capability by permitting an external debugging program to view and/or modify program variables (i.e., data values stored in program storage locations). The viewable/modifiable program variables are restricted to variables that have been registered with a debugging module located in the same memory space as the computer program. The debugging module can be selectively linked with the program, so that non-debug versions of the program do not contain the debugging module and the calls to register the program variables can either be stubbed or conditioned on a debugging constant so that the non-debug version can be generated from the same program code as the debug version. Permissions are supported by the debug module, so that the program may register some program variables as read-only and others as read-write (read-modify). Since no breakpoints are required to observe or modify the program variables, the debugging scheme is suitable for debugging real-time systems such as control systems. Also, by providing/altering the program values from within the program space using a debugging module, no overhead is present unless the debug module is actually retrieving or modifying a program variable, which also makes the debugging scheme useful in debugging real-time systems. Further, by registering only key variables, both security and compactness are achieved, since only those variables the programmer wishes to expose are exposed. The compactness of the scheme is suitable for embedded systems, in which the large amount of memory required for complete symbol tables may exceed the resources available.
[0016] Referring now to FIG. 1 , a computer system in which techniques in accordance with an embodiment of the present invention are practiced, is shown. The depicted computer system includes a workstation computer system 10 coupled to a debugger platform 10 A. The depicted computer system configuration is illustrative, and processing systems in accordance with other embodiments of the present invention include special purpose computer systems in place of workstation 10 , and/or other systems in which the debugger is executed by the same computer system. A processor 11 is coupled to a memory 12 , which contains program instructions implementing a computer program executed by processor 11 that, in at least a debug version, includes debug functionality in accordance with an embodiment of the present invention as described in detail below. Debugger platform 10 A includes a processor 11 A that is coupled to a memory 12 A for storing data and program code implementing a debugger that communicates with one or more debug modules in the computer program executed by workstation computer system 10 . Processor 11 in workstation computer 10 is also coupled to a storage interface 13 , which couples processor 11 and memory 12 to storage devices such as hard disc drive 15 and an optical drive 14 . Embodiments of the invention include computer program products that contain the debug module of the present invention stored in memory 12 as well as stored on tangible media such as a CD-ROM 16 that may be inserted into optical drive 14 to transfer computer program and other programs memory 12 for execution by processor 11 . Similarly, debugger platform 10 A includes hard disk drives 15 and optical drives 14 for accepting media such as optical storage 16 A containing the debugger program and other data and/or program code. The illustrated workstation computer system also includes input/output (I/O) interfaces and devices 19 such as mice and keyboards for receiving user input and graphical displays for displaying information, such as user interfaces constituting output of the computer program being debugged. Further, debugger platform 10 A also includes input/output (I/O) interfaces and devices 19 A such as mice and keyboards for receiving user input and graphical displays for displaying information, such as user interfaces of the debugger, that in particular, displays values of program variables of a program executing within workstation computer 10 .
[0017] Workstation computer system 10 is coupled to debugger platform 10 A by an interface 18 that couples to interface 18 A, through a wired, optical or wireless connection that may be proprietary, or take the form of a standardized serial or parallel bus such as an Ethernet connection. Debugger platform 10 A sends commands to workstation computer system 10 . The commands include commands to examine program variables of a program executing within workstation computer system 10 and commands to modify those program variables, among other commands. While the system illustrated in FIG. 1 is a remote computer debugging arrangement, it is understood that in accordance with other embodiments of the present invention, the debugger may be executed within workstation computer system 10 . Further, in other architectures such as in a distributed processing system, portions of the target program, i.e., the computer program being debugged, and the debugger program that communicates with the target program may be executed by multiple processors within the distributed processing system and may be partially executed by the same processor and partially executed by different processors. Therefore, the terms remote and local as used herein are referring generally to the local program, local tables of variables and local debug module in the sense that they are associated with and locate generally in the same memory space as the computer program, while the remote tables and remote debugger are generally located in at least a different memory space, if not in a separate computer system.
[0018] Referring now to FIG. 2 , an arrangement of program code and data within memory 12 of workstation computer system 10 and program code and data within memory 12 A of debugger platform 10 A is shown in accordance with an embodiment of the present invention. The computer program 20 is located in memory 12 is executed by workstation computer system 10 , and includes program variables 22 , which in the sense of the present invention may include constants and other data space such as allocated memory blocks referred to by pointers or other reference. Debugger 28 is executed by debug platform 10 A and communicates with a debug module 24 associated with computer program 20 . In the depicted embodiment, debug module 24 is linked with computer program 20 and forms part of the loadable image of computer program 20 . However, in other embodiments of the present invention, debug module 24 may be a dynamic library or other operating facility that is not part of the loadable image of computer program 20 .
[0019] In order to make a program variable accessible to debugger 28 executable code within computer program 20 calls an application programming interface (API) of debug module 24 that registers program variables for debugging purposes. Therefore, computer program 20 has complete control over which variables are exposed to debugger 28 . The API used to register program variables of computer program 20 is illustrated as register( ) which may be of the form:
register(variable_name, variable_reference, size_type, flags),
where variable_name is the name of the program variable, variable_reference is the storage location of the program variabl, the size_type field is an indication of the size and/or type of the program variable, and flags are access and handling flags such as read permission, write permission and whether the program variable is being registered under its human-comprehensible name or whether a hash or index should be used instead. In general, embodiments of the present invention will either implement hashing/indexing of program variable names, or will use the variable names as references, but as illustrated above for generality, anonymity can be selected on an individual basis. If indexing is used, the anonymized variables will be maintained in a separate list by index, and the variable_name argument is not needed. The register( ) API call thus may alternatively be of the form:
register(variable_reference, size_type, flags).
The variable_reference argument is needed in systems in which or variable for which a pointer or other reference must be passed for the debug module to be able to access the storage location containing the program variable. In other systems, such as interpretive languages or scripting languages, the reference is made entirely by the variable name. Therefore, in such systems, the variable_name argument and not the variable_reference argument would be supplied to the register( ) API:
register(variable_name, size_type, flags).
[0023] A collection of all of the program variables registered by computer program 20 is maintained in a local table 26 , which may be contained within debug module 24 , within a data area of computer program 20 or may be in a separate location accessible by debug module 24 . An exemplary table suitable for use as local table is shown in Table I below, in which the first row is merely explanatory and not required.
[0000] TABLE I Variable Name Storage Location Size (or type) Flags icount 00894400A0000100 8 +r, +w user_data[0] 00894400A00001A0 1024 +r profile 00894400A0000400 64 +r, +w
The first column contains the variable name, which is used to look up variables for which access is requested by debugger 28 , which are shown as request(read) and request(modify) requests in the illustration. Alternatively, as pointed out above, Table I can contain anonymized values for accessing the program variables, such as an index as illustrated in Table II below:
[0000] TABLE II 0 00894400A0000100 8 +r, +w 1 00894400A00001A0 1024 +r 2 00894400A0000400 64 +r, +w
or a hash value as illustrated in Table III below:
[0000] TABLE III soenirto#472 00894400A0000100 8 +r, +w to2es%{circumflex over ( )}&12 00894400A00001A0 1024 +r 23st@352s1 00894400A0000400 64 +r, +w
For interpretive and scripting languages, as noted above, the storage location is not directly used by the debug module, and references are made by variable name. In such implementations local table 26 may be of the form shown in Table IV below:
[0000]
TABLE IV
Variable Name
Size (or type)
Flags
icount
8
+r, +w
user_data[0]
1024
+r
[0024] Debugger 28 also has an associated table, remote table 26 A, that may match local table 26 , or may be different, in that the flags value is not needed, nor is the actual pointer to the storage location either needed to function, nor desirable to expose external to computer program 20 . In one embodiment, remote table 26 A is not needed, if the values in local table 26 are stored by index and it is desirable to display values only by index on the output display of debugger 28 . In general, remote table 26 A will contain human-readable names and optionally an index, hash or other identifier to be supplied with the read or modify requests sent to debug module 24 from debugger 28 . The received read or modify requests are then satisfied by debug module 24 using a look-up of a storage location based on the index/hash or variable name provided by debugger 28 from remote table 26 A, or for interpretive/scripting languages, by evaluating the value specified by the variable name provided by debugger 28 or a look-up of the variable name using an index, hash or other alias used in remote table 26 A to represent an entry in local table 26 . The information in remote table 26 A can be loaded from a computer-readable media, or transmitted to debugger 28 from local table 26 (or other data source) through interface 18 A that couples debugger 28 to workstation computer 10 , which may be performed when a connection is established between debugger 28 and debug module 24 , or at initialization of computer program 20 . In one embodiment of the invention, in addition to the register( ) API, debug module 24 can support an unregister( ) API, in which case, a transmission to update remote table 26 A may be required, unless it is desirable to merely fail requests to access program variables that are no longer registered. Further, while the exemplary embodiment above indicates that program variables would be registered generally at startup, and that in general, local table 26 would have a fixed set of entries, it is possible for computer program 20 to call the register API (and optionally the unregister API) on the fly to add or remove entries from local table 26 . If such techniques are employed, it would generally be desirable to synchronize remote table 26 A with local table 26 via update transmissions, and in particular if indexes are used and reassigned, such synchronization would be necessary. An example of such a use of on-the-fly program variable registration would be to only register variables in a region of program code that should not be entered under normal operating conditions. Such operation makes it possible to only expose selected program variables and only at certain times or when certain conditions, such as errors, have been encountered.
[0025] Debugger 28 retrieves and modifies values of program variables 22 within program 20 by transmitting read and modify commands to debug module 24 , which then performs the requested operations if permissions are proper. The read command may take the form <cmd_read><index> or <cmd_read><variable_name> where index and variable_name are the identifiers and cmd_read is a constant identifying the command as a read command. In response, debug module 24 returns a packet of data containing the contents of the storage location associated with the program variable that was requested, which may be formatted with a header providing identifying information associated with the command that was sent, in order to permit asynchronous and buffered transmissions of requests. To modify a program variable, debugger sends a modify command, which may take the form <cmd_modify><index><data><size> or <cmd_modify><variable_name><data><size>, where cmd_modify is a constant identifying the command as a modify command, where index and variable_name are the identifiers as above, data is the value to be written to the storage location associated with the program variable to be modified, and size is an optional value that provides a check as to whether the size of data matches the size of the variable to me modified.
[0026] Referring now to FIG. 3 , a method for registering program variables with debug module 24 in accordance with an embodiment of the present invention is shown. When debug module 24 receives a request to register a program variable (step 30 ), if debug module 24 is not present (decision 32 ), then the request is not processed, which is accomplished by a stub or other technique as described above. If debug module 24 is present (decision 32 ) if anonymizing is selected (decision 34 ), an index, hash or other anonymous identifier is generated and associated with the program variable (step 38 ), and the storage location of the program variable, the identifier, the program variable size and permission flags are added to local table 26 (step 39 ). Otherwise, if anonymizing is not selected (decision 34 ), the storage location of the program variable, the program variable name, the program variable size and permission flags are added to local table 26 (step 40 ). While the method illustrated in FIG. 3 provides an example of how to register program variables in accordance with an embodiment of the present invention, other techniques may be employed as well, in accordance with other embodiments of the present invention.
[0027] Referring now to FIG. 4 , a method for reading and modifying variables from debugger 28 , in accordance with an embodiment of the present invention, is shown. When debugger 28 transmits a request to debug module 24 (step 40 ), if debug module 24 is not present (decision 41 ), then the request is not received (step 42 ) and no processing occurs. If the debug module 24 is present (decision 41 ), the request is received and the storage location is looked up in local table 26 from the variable name or identifier provided with the request (step 43 ). If the request is a modify request (decision 44 ), the permissions are checked to determine whether permission to modify the program variable was set (decision 45 ). If modify permission was not set, then the request is failed (step 46 ), which may require a response to debugger 28 in some environments so that debugger 28 does not reflect an incorrect value for the program variable due to a failed modify operation. If modify permission was set for the program variable (decision 45 ), the new value supplied with the request is written into the storage location (step 47 ). If the request is a read request (decision 44 ), the value of the storage location is read (step 48 ) and is transmitted to debugger 28 (step 49 ). While the method illustrated in FIG. 4 provides an example of how to read and modify program variables in accordance with an embodiment of the present invention, other techniques may be employed as well, in accordance with other embodiments of the present invention.
[0028] As noted above, all or portions of the present invention may be embodied in a computer program product, which may include firmware, an image in system memory or another memory/cache, or stored on a fixed or re-writable media such as an optical disc having computer-readable code stored thereon. Any combination of one or more computer readable medium(s) may store the program in accordance with an embodiment of the invention. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
[0029] In the context of the present application, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0030] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details may be made therein without departing from the spirit and scope of the invention. | A remote debugging technique provides anonymity of program variables and selective debugging capability by providing a registration facility by which program variables are registered locally with a debugging module. An external program then communicates with the debugging modules and observes and/or modifies the program variables by specifying either an index or a variable name. The need to publish symbols is thereby averted and only the variables that a developer is interested in observing need be registered. | 6 |
FIELD OF THE INVENTION
The invention is directed to guidewires. More particularly, the invention relates to guidewires having a relatively longitudinally stiff proximal portion, and a relatively laterally flexible distal portion.
BACKGROUND OF THE INVENTION
It is often desirable to combine a number of performance features in a guidewire. For example, it is often desirable that a guidewire be relatively laterally flexible at certain points along its length, for example, near its distal end.
SUMMARY OF THE INVENTION
The invention is directed to guidewires. One embodiment includes a guidewire including a first tip member and a second tip member. The first tip member has a first end, and a second end. The second tip member has a distal portion and a proximal portion. The two tip members are coupled together, preferably in an arrangement that can effect the flexibility of the guidewire at certain points along its length.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a guidewire in accordance with an exemplary embodiment of the invention;
FIG. 2 is a partial cross-sectional view of a distal tip portion of the guidewire of FIG. 1;
FIG. 3 is a partial cross-sectional view of a distal tip portion of a guidewire in accordance with an additional exemplary embodiment of the invention;
FIG. 4 is an additional partial cross-sectional view of a distal tip portion of the guidewire of FIG. 3;
FIG. 5 is an additional partial cross-sectional view of a distal tip portion of the guidewire of FIG. 3;
FIG. 6 is a perspective view of a distal tip portion of the guidewire of FIG. 3;
FIG. 7 is an additional perspective view of a distal tip portion of the guidewire of FIG. 3;
FIG. 8 is a partial cross-sectional view of a distal tip portion of a guidewire in accordance with an additional exemplary embodiment of the invention; and
FIG. 9 is a partial cross-sectional view of a distal tip portion of a guidewire in accordance with an additional exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered in like fashion. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. In some cases, the drawings may be highly diagrammatic in nature. Examples of constructions, materials, dimensions, and manufacturing processes are provided for various elements. Those skilled in the art will recognize that many of the examples provided have suitable alternatives which may be utilized.
FIG. 1 is a plan view of a guidewire 100 in accordance with the invention. Guidewire 100 includes an elongate proximal portion 102 terminating at a proximal end 110 and distal tip portion 104 terminating at a distal end 112 . Elongate proximal portion 102 comprises an elongate body member 106 . Distal tip portion 104 includes an atraumatic tip 108 and a sheath 120 . In a preferred embodiment, the distal end of sheath 120 is fixed to atraumatic tip 108 and the proximal end of sheath 120 is fixed to elongate body member 106 .
The sheath 120 comprises a wire 122 forming a plurality of turns 124 . In a preferred embodiment, adjacent turns 124 are disposed in close proximity to one another. In a particularly preferred embodiment, adjacent turns 124 contact each other across substantially their entire length. In this particularly preferred embodiment, sheath 120 has a high level of longitudinal pushability and a high level of lateral flexibility.
FIG. 2 is a partial cross-sectional view of distal tip portion 104 of guidewire 100 of FIG. 1 . In FIG. 2, it may be appreciated that atraumatic tip 108 of guidewire 100 is fixed to a distal end 134 of a first tip member 126 that extends distally from a body taper 130 of elongate body member 106 . An intermediate portion 132 of first tip member 126 extends between distal end 134 of first tip member 126 and a proximal end 136 of first tip member 126 . Intermediate portion 132 of first tip member 126 comprises a proximal segment 138 , a distal segment 140 , and a tapered portion 142 extending between proximal segment 138 and distal segment 140 .
Distal tip portion 104 of guidewire 100 also includes a second tip member 128 . In a preferred embodiment, a proximal portion 144 of second tip member 128 is coupled to end 136 of first tip member 126 . Proximal portion 144 of second tip member 128 is fixed to body taper 130 of elongate body member 106 such that second tip member 128 is coupled to first tip member 126 via body taper 130 . Second tip member 128 may be fixed to body taper 130 of elongate body member 106 in various ways. Some examples of suitable methods of fixing second tip member 128 to elongate body member 106 include soldering, brazing, adhesive bonding, welding and the like. It is to be appreciated that various welding processes may be utilized without deviating from the spirit and scope of the present invention. Examples of welding processes that may be suitable in some applications include LASER welding, resistance welding, TIG welding, and microplasma welding. LASER welding equipment that may be suitable in some applications is commercially available from Unitek Miyachi of Monrovia, Calif. and Rofin-Sinar Incorporated of Plymouth, Mich. Resistance welding equipment that may be suitable in some applications is commercially available from Palomar Products Incorporated of Carlsbad, Calif. and Polaris Electronics of Olathe, Kans. TIG welding equipment that may be suitable in some applications is commercially available from Weldlogic Incorporated of Newbury Park, Calif. Microplasma welding equipment that may be suitable in some applications is commercially available from Process Welding Systems Incorporated of Smyrna, Tenn.
The distal portion of slope 150 and/or tong 148 can be attached to the first tip member 126 using adhesives, for example polyurethane, silicone, cyanoacrylates, epoxies, and the like.
A distal portion 146 of second tip member 128 is disposed about intermediate portion 132 of first tip member 126 . Preferably, distal portion 146 of second tip member 128 includes a slope 150 and a tong 148 that extends distally from second tip member 128 . It should be noted that embodiments of second tip member 128 are possible in which distal portion 146 does not include tong 148 . In a preferred embodiment, second tip member 128 comprises a tubular wall defining a lumen.
Preferably, the shape of the distal portion 146 is arranged and configured such that the distance that the first tip member 126 deflects in a first direction before engaging the distal portion 146 of the second tip member 228 is different than the distance that the first tip member 126 deflects in a second direction before intermediate portion 132 of the first tip member 126 engages second tip member 128 . Preferably, the lateral stiffness of the distal portion 146 of the guidewire 100 changes when the first tip member 126 engages the second tip member 128 .
In a preferred embodiment, second tip member 128 comprises a shape memory material. Examples of shape memory materials which may be suitable in some applications include shape memory polymers and shape memory alloys. Examples of shape memory alloys which may be suitable in some applications include nitinol. The word nitinol was coined by a group of researchers at the United States Naval Ordinance Laboratory (NOL) who were the first to observe the shape memory behavior of this material. The word nitinol is an acronym including the chemical symbol for nickel (Ni), the chemical symbol for titanium (Ti), and an acronym identifying the Naval Ordinance Laboratory (NOL). Nitinol is commercially available from Memry Technologies (Brookfield, Conn.), TiNi Alloy Company (San Leandro, Calif.), and Shape Memory Applications (Sunnyvale, Calif.). In an especially preferred embodiment, second tip member 128 comprises superelastic nitinol.
In FIG. 2, it may be appreciated that wire 122 of sheath 120 of distal tip portion 104 has a generally circular cross-sectional shape. The term “wire”, as used in describing wire 122 , should not be mistaken as limiting wire 122 to elements having a circular cross section. The cross section of wire 122 may be any number of shapes. For example, the cross section of wire 122 could be rectangular, elliptical, and the like. Likewise, the term “wire”, as used in describing wire 122 , should not be mistaken as being limited to metallic materials. In fact, wire 122 may be comprised of many metallic and non-metallic materials. Examples of metallic materials that may be suitable in some applications include stainless steel, nitinol, tantalum, gold, and titanium. Examples of non-metallic materials that may be suitable in some applications may be found in the list immediately below which is not exhaustive: polycarbonate, poly(L-lactide) (PLLA), poly(D,L-lactide) (PLA), polyglycolide (PGA), poly(L-lactide-co-D,L-lactide) (PLLA/PLA), poly(L-lactide-co-glycolide) (PLLA/PGA), poly(D, L-lactide-co-glycolide) (PLA/PGA), poly(glycolide-co-trimethylene carbonate) (PGA/PTMC), polyethylene oxide (PEO), polydioxanone (PDS), polycaprolactone (PCL), polyhydroxylbutyrate (PHBT), poly(phosphazene), polyD,L-lactide-co-caprolactone) (PLA/PCL), poly(glycolide-co-caprolactone) (PGA/PCL), polyanhydrides (PAN), poly(ortho esters), poly(phoshate ester), poly(amino acid), poly(hydroxy butyrate), polyacrylate, polyacrylamid, poly(hydroxyethyl methacrylate), polyurethane, polysiloxane and their copolymers. Embodiments of the present invention have also been envisioned in which wire 122 has a tubular cross section.
FIG. 3 is a partial cross-sectional view of a distal tip portion 204 of a guidewire 200 in accordance with an additional exemplary embodiment of the invention. In FIG. 3 , it may be appreciated that distal tip portion 204 of guidewire 200 includes a first tip member 226 having a first end 252 , a second end 254 , and an intermediate portion 232 extending therebetween. First end 252 of first tip member 226 is fixed to an atraumatic tip 208 of guidewire 200 . Second end 254 of first tip member is fixed to an elongate body member 206 of guidewire 200 .
Distal tip portion 204 of guidewire 200 also includes a second tip member 228 . In a preferred embodiment, a proximal portion 244 of second tip member 228 is coupled to the second end 254 of first tip member 226 . Proximal portion 244 of second tip member 228 is fixed to body taper 230 of elongate body member 206 such that second tip member 228 is coupled to first tip member 226 via body taper 230 . Second tip member 228 may be fixed to body taper 230 of elongate body member 206 in various ways. Methods of fixing second tip member 228 to elongate body member 206 that may be suitable in some applications include soldering, brazing, adhesive bonding, welding, and the like.
A distal portion 246 of second tip member 228 is disposed about intermediate portion 232 of first tip member 226 . In a preferred embodiment, first tip member 226 and second tip member 228 are configured such that intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 after a pre-selected deflection of first tip member 226 . For example, intermediate portion 232 of first tip member 226 may seat against and/or couple with distal portion 246 of second tip member 228 . In a preferred embodiment, the lateral stiffness of distal tip portion 204 of guidewire 200 changes when intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 .
It is to be appreciated that embodiments of distal tip portion 204 are possible in which an adhesive joint is disposed between intermediate portion 232 of first tip member 226 and distal portion 246 of second tip member 228 . Embodiments of distal tip portion 204 are possible in which a soft polymer tube is disposed between first tip member 226 and second tip member 228 .
Distal portion 246 of second tip member 228 includes a slope 250 . In a preferred embodiment, the shape of distal portion 246 may preferably be selected so that the distance that first tip member 226 deflects in a first direction before engaging second tip member 228 is different than the distance that first tip member 226 deflects in a second direction before intermediate portion 232 of first tip member 226 engages second tip member 228 .
FIG. 4 is an additional partial cross-sectional view of distal tip portion 204 of guidewire 200 of FIG. 3 . First tip member 226 has been deflected in a first direction 256 such that first end 252 has been displaced by a first distance 258 . In FIG. 4, it may be appreciated that intermediate portion 232 of first tip member 226 is seated against distal portion 246 of second tip member 228 . In a preferred embodiment, first tip member 226 and second tip member 228 are configured such that intermediate portion 232 of first tip member 226 engages distal portion of second tip member 228 after a pre-selected deflection in first direction 256 . Also in a preferred embodiment, the lateral stiffness of distal tip portion 204 of guidewire 200 changes when intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 .
FIG. 5 is an additional partial cross-sectional view of distal tip portion 204 of guidewire 200 of FIG. 3 . First tip member 226 has been deflected in a second direction 260 such that first end 252 has been displaced by a second distance 262 . In FIG. 5, it may be appreciated that intermediate portion 232 of first tip member 226 is seated against distal portion 246 of second tip member 228 . In a preferred embodiment, first tip member 226 and second tip member 228 are configured such that intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 after a pre-selected deflection in second direction 260 . Also in a preferred embodiment, the lateral stiffness of distal tip portion 204 of guidewire 200 changes when intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 .
FIG. 6 is a perspective view of first tip member 226 and second tip member 228 of guidewire 200 of FIG. 3 . For purposes of simplicity and clarity, only first tip member 226 and second tip member 228 are shown in FIG. 6 . In the embodiment of FIG. 6, first tip member 226 has been deflected in a third direction 264 such that first end 252 has been displaced by a third distance. In FIG. 6, it may be appreciated that intermediate portion 232 of first tip member 226 is seated against distal portion 246 of second tip member 228 . In a preferred embodiment, first tip member 226 and second tip member 228 are configured such that intermediate portion 232 of first tip member 226 engages distal portion of second tip member 228 after a pre-selected deflection in third direction 264 . Also in a preferred embodiment, the lateral stiffness of distal tip portion 204 of guidewire 200 changes when intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 .
FIG. 7 is a perspective view of first tip member 226 and second tip member 228 of guidewire 200 of FIG. 3 . For purposes of simplicity and clarity, only first tip member 226 and second tip member 228 are shown in FIG. 7 . First tip member 226 has been deflected in a fourth direction 266 such that first end 252 has been displaced by a fourth distance. In FIG. 7, it may be appreciated that intermediate portion 232 of first tip member 226 is seated against distal portion 246 of second tip member 228 . In a preferred embodiment, first tip member 226 and second tip member 228 are configured such that intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 after a pre-selected deflection in fourth direction 266 . Also in a preferred embodiment, the lateral stiffness of distal tip portion 204 of guidewire 200 changes when intermediate portion 232 of first tip member 226 engages distal portion 246 of second tip member 228 . In the embodiment of FIG. 6 and FIG. 7, the third distance is preferably substantially equal to the fourth distance.
FIG. 8 is a partial cross-sectional view of a distal tip portion 304 of a guidewire 300 in accordance with an additional exemplary embodiment of the invention. In FIG. 8, it may be appreciated that distal tip portion 304 of guidewire 300 includes a first tip member 326 having a first end 352 , a second end 354 , and an intermediate portion 332 extending therebetween. First end 352 of first tip member 326 is fixed to an atraumatic tip 308 of guidewire 300 . Second end 354 of first tip member is fixed to an elongate body member 306 of guidewire 300 . Intermediate portion 332 of first tip member 326 comprises a proximal segment 338 , a distal segment 340 , and a tapered portion 342 extending between proximal segment 338 and distal segment 340 .
Distal tip portion 304 of guidewire 300 also includes a second tip member 328 which is disposed about first tip member 326 . In a preferred embodiment, a proximal portion 344 of second tip member 328 is coupled to second end 354 of first tip member 326 . A proximal portion 344 of second tip member 328 is fixed to a body taper 330 of elongate body member 306 such that second tip member 328 is coupled to first tip member 326 via body taper 330 . Second tip member 328 may be fixed to body taper 330 of elongate body member 306 in various ways. Methods of fixing second tip member 328 to elongate body member 306 that may be suitable in some applications include soldering, brazing, adhesive bonding, welding, and the like.
A distal portion 346 of second tip member 328 is disposed about intermediate portion 332 of first tip member 326 . Second tip member 328 comprises a tubular wall defining a lumen. Distal portion 346 includes a necked portion 368 . In a particularly preferred embodiment, second tip member 328 comprises nitinol. In an especially preferred embodiment, second tip member 328 comprises superelastic nitinol. When second tip member 328 comprises nitinol, necked portion 368 of second tip member 328 preferably provides a smooth transition in the lateral stiffness of distal tip portion 304 of guidewire 300 .
FIG. 9 is a partial cross-sectional view of a distal tip portion 404 of a guidewire 400 in accordance with yet another exemplary embodiment of the invention. In FIG. 9, it may be appreciated that distal tip portion 404 of guidewire 400 includes a distal tip member 470 having a first end 452 , a second end 454 , and an intermediate portion 432 extending therebetween. First end 452 of distal tip member 470 is fixed to an atraumatic tip 408 of guidewire 400 .
Second end 454 of distal tip member 470 is fixed to a distal portion 446 of a second tip member 472 . A proximal portion 444 of second tip member 472 is fixed to a body taper 430 of an elongate body member 406 of guidewire 400 . Methods of fixing second tip member 472 to elongate body member 406 that may be suitable in some applications include soldering, brazing, adhesive bonding, welding, and the like.
In a preferred embodiment, second tip member 472 comprises a tubular wall defining a lumen. A distal portion 446 of second tip member 472 includes a slope 450 and a tong 448 that extends distally from intermediate tip member 472 . In a particularly preferred embodiment, second tip member 472 comprises nickel and titanium. In an especially preferred embodiment, second tip member 472 comprises nitinol.
Guidewires embodying the invention can be utilized in a wide variety of medical procedures. For example, guidewires are often utilized to assist in advancing the intravascular catheter through the vasculature of a patient. A guidewire may be inserted into the vascular system of the patient at an easily accessible location and urged forward through the vasculature until the tip of the guidewire is proximate the target site. A proximal end of the guidewire may then be inserted into a guidewire lumen of a catheter. The tip of the catheter may be advanced along the length of the guidewire until it reaches the target site.
Typically, the guidewire enters the patient's vasculature at a convenient location such as a blood vessel in the neck or near the groin. Once the distal portion of the guidewire has entered the patient's vascular system, the physician may urge the distal tip forward by applying longitudinal forces to the proximal portion of the guidewire. For the guidewire to effectively communicate these longitudinal forces, it is desirable that the guidewire have a high level of pushability and kink resistance, particularly near its proximal end.
The path taken by a guidewire through the vascular system is often tortuous, requiring the guidewire to change direction frequently. In some cases, it may even be necessary for the guidewire to double back on itself. In order for the guidewire to conform to a patient's tortuous vascular system, it is desirable that guidewires be laterally flexible, particularly near the distal end.
While advancing the guidewire through the tortuous path of the patient's vasculature, physicians often apply torsional forces to the proximal portion of the guidewire to aid in steering the guidewire. To facilitate the steering process, the distal portion of the guidewire may be bent by the physician. Torsional forces applied on the proximal end must translate to the distal end to aid in steering. It is therefore desirable that the proximal portion of a guidewire have a relatively high level of torqueability to facilitate steering.
The distance between the access site and the target site is often in excess of 100 cm. The inside diameter of the vasculature at the access site is often less than 5 mm. In light of the geometry of the patient's body, it is desirable to combine the features of torqueability, pushability, and flexibility into a guidewire that is relatively long and has a relatively small diameter.
Ideally, the distal end of a guidewire will be adapted to reduce the probability that the vascular tissue will be damaged as the guidewire progresses through the vascular system. This is sometimes accomplished by fixing a rounded tip member to the distal end of the guidewire.
After the guidewire has been navigated through the patient's vascular system so that its distal end is adjacent the target site, an intravascular catheter may be advanced over the guidewire. The catheter may be used for various diagnostic and/or therapeutic purposes. One example of a diagnostic use for a catheter is the delivery of radiopaque contrast solution to enhance fluoroscopic visualization. In this application, the catheter provides a fluid path leading from a location outside the body to a desired location inside the body of a patient.
Examples of therapeutic purposes for catheters include percutaneous transluminal angioplasty (PTA) and percutaneous transluminal coronary angioplasty (PTCA). These angioplasty techniques typically involve the use of a balloon catheter. During these procedures, the distal end of the guidewire is often positioned in the ostium of the coronary artery. The balloon catheter may then be advanced over the guidewire such that the balloon is positioned proximate the restriction in the diseased vessel. The balloon is then inflated and the restriction in the vessel is opened. In this application, it is desirable that the guidewire provide a low friction path for the balloon catheter.
One additional example of a useful therapeutic application of catheters is the treatment of intracranial aneurysms in the brain. An aneurysm which is likely to rupture, or one which has already ruptured may be treated by delivering an embolic device to the interior of the aneurysm. The embolic device encourages the formation of a thrombus inside the aneurysm. The formation of a thrombus reduces the probability that an aneurysm will rupture. Or, in cases where an aneurysm has already ruptured, the formation of a thrombus will reduce the probability that the previously ruptured aneurysm will re-bleed. One commonly used embolic device comprises a tiny coil of wire.
When treating an aneurysm with the aid of a catheter, the catheter tip is typically positioned proximate the aneurysm site. The embolic device is then urged through the lumen of the catheter and introduced into the aneurysm. Shortly after the thrombus agent is placed in the aneurysm, a thrombus forms in the aneurysm and is shortly thereafter complemented with a collagenous material that significantly lessens the potential for aneurysm rupture.
Having thus described some embodiments of the present invention, those of skill in the art will readily appreciate that yet other embodiments may be made and used within the scope of the claims hereto attached. Numerous advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The invention's scope is defined in the language in which the appended claims are expressed. | Methods and devices relating to guidewires. In one embodiment, a distal tip portion of a guidewire comprises a first tip member and a second tip member. The first tip member has a first end, and a second end. The second tip member has a distal portion and a proximal portion. The first and second tip members are coupled together, preferably in an arrangement that can effect the flexibility of the guidewire at certain points along its length. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/862,883 entitled “Low Cost, High Pin Count, Wafer Sort Automated Test Equipment (ATE) Device under Test (DUT) Interface for Testing Electronic Devices in High Parallelism” filed Oct. 25, 2006 which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention is related generally to electronic device testing. More specifically, the present invention is related to device-under-test (DUT) interface for mating to a probe card used in testing electronic devices.
BACKGROUND
[0003] Complexity levels of electronic device testing vary tremendously, from simple manual low-volume/low-complexity testing performed with perhaps an oscilloscope and voltmeter, to personal computer-based medium-scale testing, to large-scale/high-complexity automated test equipment (ATE). Manual and personal computer-based testing are typically applied to testing discrete devices, specific components of an integrated circuit, or portions of a printed circuit board. In contrast, ATE testing is used to test functionality of a plurality of complex integrated circuits such as memory circuits or hundreds of dice on a wafer prior to sawing and packaging.
[0004] When testing ICs on a wafer, it is cost effective to test as many devices as possible in parallel, thus reducing the test time per wafer. Test system controllers have evolved to increase the total number of channels and hence the number of devices that can be tested in parallel. However, a test system controller with increased test channels is typically a significant cost factor for a test system, as is a probe card with complex routing lines used to accommodate multiple parallel test channels. Thus, an overall probe card architecture that allows increased test parallelism without requiring increased test system controller channels and without increased probe card routing complexity and cost is desirable.
[0005] FIG. 1 shows a block diagram of an automated test system 100 . The test system 100 includes a test system controller 101 , a test head 105 , and a test prober 107 . The test system controller 101 is frequently a microprocessor-based computer and is electrically connected to the test head 105 by a communication cable 103 . The test prober 107 includes a stage 109 on which a semiconductor wafer 111 may be mounted, and a probe card 113 for testing DUTs on the semiconductor wafer 111 . The stage 109 is movable to contact the wafer 111 with a plurality of test probes 115 on the probe card 113 . The probe card 113 communicates with the test head 105 through a plurality of channel communications cables 117 .
[0006] In operation, the test system controller 101 generates test data which are transmitted through the communication cable 103 to the test head 105 . The test head in turn transmits the test data to the probe card 113 through the plurality of communication cables 117 . The probe card then uses these data to probe DUTs (not shown explicitly) on the wafer 111 through the plurality of test probes 115 . Test results are then provided from the DUTs on the wafer 111 back through the probe card 113 to the test head 105 for transmission back to the test system controller 101 . Once testing is completed and known-good dice are identified, the wafer is 111 diced.
[0007] Test data provided from the test system controller 101 are divided into individual test channels provided through the communications cable 103 and separated in the test head 105 so that each channel is carried to a separate one of the plurality of test probes 115 . Channels from the test head 105 are linked by the channel communications cables 117 to the probe card 113 . The probe card 113 then links each channel to a separate one of the plurality of test probes 115 .
[0008] With reference to FIG. 2 and continued reference to FIG. 1 , a cross-sectional view of components contained within the probe card 113 indicate routing of mechanical and electrical couplings between the wafer 111 and the test head 105 . The probe card 113 provides both electrical pathways and mechanical support for the plurality of test probes 115 that will directly contact the wafer 111 . Electrical pathways on the probe card 113 are provided through a printed circuit board (PCB) 201 , an interposer 203 , and a space transformer 205 . Test data from the test head 105 are provided through the channel communications cables 117 typically connected around the periphery of the PCB 201 . A plurality of channel transmission lines 207 distribute signals from a plurality of electrical interconnects 209 (only two electrical interconnects are shown for clarity) mounted on the PCB 201 to match the routing pitch of pads on the space transformer 205 . The interposer 203 includes a substrate 211 with a plurality of spring probe electrical contacts 213 disposed on both sides. The interposer 203 electrically connects individual pads on the PCB 201 to pads forming a land grid array (LGA, not shown explicitly) on the space transformer 205 . A plurality of electrical traces 215 in a substrate 217 of the space transformer 205 distribute or “space transform” connections from the LGA to the plurality of test probes 115 , configured in an array. The space transformer substrate 217 is typically constructed from either multi-layered ceramic or organic-based laminates. The space transformer substrate 217 with embedded circuitry, probes, and LGA is referred to as a probe head.
[0009] Mechanical support for the electrical components is provided by a back plate 219 , a probe head bracket 221 , a probe head stiffener frame 223 , a plurality of leaf springs 225 , and leveling pins 227 . The frame 223 surrounds the probe head and maintains a close tolerance to the bracket 221 such that lateral motion is limited.
[0010] The leveling pins 227 complete the mechanical support for the electrical elements and provide for leveling of the space transformer 205 . The leveling pins 227 are adjusted so that brass spheres 229 provide a point contact with the space transformer 205 . The spheres 229 contact outside the periphery of the LGA of the space transformer 205 to maintain electrical isolation from electrical components. Motion of the leveling pins 227 is opposed by the plurality of leaf springs 225 so that the spheres 229 are kept in contact with the space transformer 205 .
[0011] The complexity of the automated test system 100 an the probe card 113 demonstrates an inherent potential problem in contemporary ATE systems. For example, a critical component of the probe card 113 is the plurality of electrical interconnects 209 . All generated test data and resulting DUT data are funneled through the plurality of electrical interconnects 209 . In contemporary ATE systems, the plurality of electrical interconnects 209 are designed using pogo pins, coaxial cables, zero insertion force clamp assemblies, or other expensive interconnect technologies. Pogo pins suffer from reliability problems associated with repeatable contact resistance. Coaxial cables are large in diameter and can not be contained in a small volume of space. Zero insertion force clamp assemblies are mechanically complex and mechanics associated with operations of the assembly occupy valuable real estate which could otherwise be used for more interconnects.
[0012] Therefore, what is needed is a simple, economical, and robust means of interacting bidirectional electrical signals between the test head and probe card. Such an interface should have individually replaceable contact points with a sufficient z-dimension deformational stroke to allow for slight misalignment errors or irregularities in the surface of the probe head. Further, the interface should reduce a deflection in the probe card by minimizing an applied load to compress the contact points. The reduced deflection allows a large contactor array to be mounted on the probe card, further increasing parallelism.
SUMMARY OF THE INVENTION
[0013] In an exemplary embodiment, the present invention is an interface device to communicate electrical signals from a probe card used to test electronic circuits. The interface device includes at least one interposer configured to electrically couple to the probe card and a plurality of mechanical springs mechanically coupled to the at least one interposer. Each of the plurality of mechanical springs is removably arranged such that one or more of the plurality of mechanical springs may be removed. A flexible circuit is electrically coupled to the plurality of mechanical springs. The flexible circuit is further configured to mechanically couple to the at least one interposer.
[0014] In another exemplary embodiment, the present invention is an interface device to communicate electrical signals from a probe card used to test electronic circuits. The interface device includes a plurality of interposers configured to be electrically coupled to the probe card and a plurality of mechanical springs mechanically coupled to each of the plurality of interposers. Each of the plurality of mechanical springs is at least partially formed from an electrically conductive material. Each of the plurality of mechanical springs further has a stroke of at least 100 μm and is removably arranged such that one or more of the plurality of mechanical springs may be removed for replacement. A plurality of flexible circuits is configured to be mechanically coupled to select ones of the plurality of interposers and electrically couple to select ones of the plurality of mechanical springs.
[0015] In another exemplary embodiment, the present invention is an interposer for communicating electrical signals from a probe card used to test electronic circuits. The interposer includes a plurality of mechanical springs mechanically coupled to the interposer and arranged in a matrix. Each of the plurality of mechanical springs is at least partially formed from an electrically conductive material. Each of the plurality of mechanical springs further has a stroke of at least 100 μm and is removably arranged such that one or more of the plurality of mechanical springs may be removed for replacement. At least one flexible circuit is configured to be mechanically coupled to the interposer and electrically coupled to select ones of the plurality of mechanical springs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of an ATE system of the prior art.
[0017] FIG. 2 is a cross-sectional view of a prior art probe card contained in the system of FIG. 1 .
[0018] FIG. 3 is a simplified block diagram of an exemplary embodiment of the present invention.
[0019] FIG. 4 is a perspective view of an exemplary probe card of the present invention.
[0020] FIG. 5 is a plan view of an exemplary interposer of the present invention used to interface electrical signals to the probe card of FIG. 4 through a plurality of mechanical springs.
[0021] FIG. 6 is an elevation view showing a specific embodiment with optional daughter cards mounting on the probe card of FIG. 4 .
DETAILED DESCRIPTION
[0022] With reference to FIG. 3 , a portion of a DUT interface 300 includes a probe card 301 , a probe card interposer 303 , and a mechanical backing plate 305 electrically and mechanically connected to a flex circuit 309 . Electrical communication is provide between the mechanical backing plate 305 and the probe card interposer 303 through a plurality of mechanical springs 307 . Ideally, each of the plurality of mechanical springs 307 should be designed to be individually field-replaceable with a sufficient stroke (i.e., greater than 100 μm) to allow for any misalignment error or surface irregularities between the probe card interposer 303 and the mechanical backing plate 305 . Additionally, the plurality of mechanical springs 307 may be mounted on either the probe card interposer 303 , the mechanical backing plate 305 , or both (i.e., a spring-to-spring contact). No connectors are required to be mounted directly on the probe card 301 . Each of the plurality of mechanical springs may take various forms known in the art and include various compressional spring types such as volute, helical, coil, cantilever, or leaf springs. Both macro-mechanical and micro-mechanical methods for producing various forms of spring elements are also known in the art. The probe card interposer is described in more detail with reference to FIG. 5 , below.
[0023] The flex circuit 309 may either be a simple flat cable interconnect or it may be a flexible electronic interconnect containing active and passive device circuitry. Flex circuits of the latter type involve fabricating various device types on plastic, such as a polyethyleneterephthalate (PET) substrate. PET substrates are commonly employed in lightweight circuit applications, such as a cellular telephone or personal data assistant (PDA). Such circuits are known in the art and electronic devices are formed on, for example, a PET substrate deposited with silicon dioxide and polysilicon followed by an excimer laser annealing (ELA) anneal step. In a simple case, flexible electronics can be made using similar components used on rigid printed circuit boards.
[0024] The flex circuit 309 is electrically and mechanically connected to a pin electronic board 313 through a pin board interposer 311 . The pin board interposer 311 is fastened to the pin electronic board 313 by, for example, mechanical fasteners 315 . The mechanical fasteners 315 may be screws, rivets, wire bails, or other fastening means known in the art.
[0025] The flex circuit 309 may be routed to the probe card 301 and bent by, for example, 90 degrees to lay substantially horizontal to a plane of the probe card 301 . The probe card interposer 303 may be placed on top of the flex circuit 309 . The probe card interposer 303 may be floating on top of mechanical springs to allow greater compliance along the vertical axis. The probe card 301 is clamped against or is otherwise attached to the mechanical backing plate 305 , which applies a load required to compress the probe card interposer 303 . The probe card interposer 303 may have its own set of springs to allow compression over an interface area of the probe card due to any surface irregularities or warpage of the probe card 301 caused by load and temperature. Hence, mechanical springs may be used to allow each of a plurality of the probe card interposers 303 to float individually.
[0026] In FIG. 4 , a top perspective view of the probe card 301 showing an exemplary arrangement includes a plurality of probe card interposers 303 and a plurality of optional daughter board edge connectors 401 . Mounting of the daughter board edge connectors 401 is described in more detail with reference to FIG. 6 , below. A probe tip 403 is located on the bottom side of the probe card 301 . Due to the relatively small size of each of the plurality of probe card interposers 303 , a larger probe tip 403 array may be used to contact more devices on a substrate (e.g., a wafer) in parallel. In a specific exemplary embodiment, there are 64 probe card interposers 303 DUT interface and an equal number of daughter board edge connectors 401 interspersed with the probe card interposers 303 . Other arrangements and numbers could readily be envisioned by a skilled artisan based on layouts disclosed herein. Continuing with the specific exemplary embodiment, a diameter, D pc , of the probe card 301 is 510 mm and a diameter, D pt , of the probe tip is 400 mm. Each of these dimensions may be changed based on relative sizes needed for substrates probed (e.g., probing a next generation silicon wafer may require a 450 mm probe tip 403 ).
[0027] In FIG. 5 , a detailed plan view of the spring contact side of the probe card interposer 303 includes a plurality of mechanical springs 307 . In a specific exemplary embodiment, the plurality of mechanical springs is laid out in an 8 column by 52 row matrix (thus, there are 416 mechanical springs 307 ). The matrix has a 1 mm by 1.25 mm pitch respectively for the columns and rows. Consequently, an overall size of the probe card interposer 303 is 9 mm×66.25 mm.
[0028] Depending upon spring type chosen, each of the plurality of mechanical springs 307 requires a force of only about 30 N (Newtons) or a total force of 12,480 N per each of the probe card interposers 303 . Thus, the total force on a probe card is significantly less than required under the prior art, allowing more interconnects to be used per probe card with less overall deflection. One field-replaceable spring type that may be used with the present invention is employed in the InterCon cLGA® land grid array socket system (manufactured by Amphenol InterCon Systems, Inc., Harrisburg, Pa.). The Amphenol spring has a beryllium copper base with a gold over nickel-plated overcoat.
[0029] Significantly, the probe card interposer 303 allows for a much smaller footprint than the prior art since ZIF connectors or similar large and expensive connectors are not required. Thus, more interposers may be used, allowing a higher number of DUTs to be tested in parallel. The probe card interposer 303 may be mounted and remain permanently on the probe card 301 ( FIG. 3 ). In the specific exemplary embodiment described above with 64 probe card interposers 303 per probe card 301 and 416 mechanical springs 307 per interposer, a total of 26,624 signal I/O, ground, power, and sense locations are available per DUT interface.
[0030] In FIG. 6 , an elevation view of a portion of the probe card 301 indicates how each optional daughter card 601 may be mounted orthogonally through the use of the edge connector 401 . Contacts on the edge connector 401 (not shown) electrically connect to a plurality of edge fingers 603 mounted on an edge of the daughter card 601 . In a specific exemplary embodiment, the optional daughter card 601 is 6 mm thick with an area of 25 mm by 45 mm. Electronic devices may be mounted on one or both sides of the daughter card 601 .
[0031] The probe card interposers 303 of the present invention provide significant advantages over the prior art. For example, due to the relatively small size of the probe card interposers 303 , a large printed circuit board may be employed for improved routing of high frequency traces, more space is available for mechanically clamping the probe card to a DUT interface, and sufficient volume is present to mount a large number of orthogonal daughter boards on the tester side of the probe card. Daughter boards may be used for additional circuitry to aid in increasing the number of DUTs which can be tested in parallel. Also, a larger footprint is available for mounting electronic circuitry on the probe card and a high ratio of power supply contacts to signal contacts may be used. This high ratio is especially advantageous for testing low pin count devices (e.g., memory devices). Further, no mechanical tooling holes need be drilled in the area of the probe card where traces need to be routed thus both reducing a layer count of the probe card and increasing the number of the DUTs that can be tested in parallel.
[0032] In the foregoing specification, the present invention has been described with reference to specific embodiments thereof. It will, however, be evident to a skilled artisan that various modifications and changes can be made thereto without departing from the broader spirit and scope of the present invention as set forth in the appended claims. For example, various types of conducting materials may be used for the spring contacts. Alternatively, non-conductive spring materials may be employed which have a conductive outer layer, such as gold plating. Also, various fabrication technologies, such as micro-electromechanical systems (MEMS), may be employed in future generations of probe card interposers to manufacture spring contacts. These and various other embodiments and techniques are all within a scope of the present invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | An interference device to communicate electrical signals from a probe card used to test electronic circuits. The interface device includes at least one interposer configured to electrically couple to the probe card and a plurality of mechanical springs mechanically coupled to the at least one interposer. Each of the plurality of mechanical springs is removably arranged such that one or more of the plurality of mechanical springs may be removed. A flexible circuit is electrically coupled to the plurality of mechanical springs. The flexible circuit is further configured to mechanically couple to the at least one interposer. | 6 |
This is a continuation of International Application No. PCT/GB97/02560 filed Sep. 22, 1997 (now expired), the entire disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The invention is in the field of needleless injectors which use a capsule for containing a liquid drug to be injected, and needle-type hypodermic syringe bodies.
BACKGROUND OF THE INVENTION
Needleless injectors are used as an alternative to conventional hypodermic injectors to deliver medicaments through the patient's skin into the underlying tissues. Such injectors use a high pressure piston pump to dispense a jet of liquid drug with sufficient force to penetrate the skin, and thereafter deposit the drug into the dermal, subcutaneous or muscular tissues.
The drug is dispensed from a cylindrical chamber, having a fine orifice at one end through which the drug is discharged. A piston is slidingly and sealingly located in the chamber, and the drug is contained within the space between the orifice and piston. To make an injection, the orifice is placed on the skin, and by operating a release mechanism, the piston is acted upon by a force which may be derived from a spring, pressurised gas or chemical reaction.
The capsule may be filled by the user, or may be prefilled and pre-assembled to an actuator. In the latter case particularly, the materials from which the capsule and piston are constructed must be inert to the drug—i.e. they must not react with the drug chemically, nor physically, and must not contain harmful extractives that might contaminate the drug. The choice of materials is small: borosilicate glass is the most favoured capsule material when drugs must be stored for more than a few hours. If an alternative material is selected for the capsule, years of testing must be done to validate that material, whereas borosilicate glass has a known compatibility with most drugs.
During the injection, the pressure generated in the capsule is at least 100 bars, and it is preferable, in order to avoid leakage during injection, that the orifice is integral with the cylindrical chamber. Furthermore, the form and dimension of the orifice is critical to the injection performance, and for repeatable results these features should be made to close tolerances. However, glass is a difficult material to mould and maintain such close tolerances over many millions of components. One traditional method is to work the heated and softened end of a glass tube on a lathe, and by applying a shaping wheel or paddle, to close up one end onto a mandrel to form the orifice. This is a relatively crude method, and the only parameters that may be controlled accurately are the orifice diameter and the diameter of the surrounding glass: the length and entry profile of the orifice are left to chance because the process shapes only the outside of the tube and the orifice diameter. An alternative process is moulding, whereby a hot “gob” of molten glass is moulded in a die. This process is suitable for large components, but needleless injector capsules are seldom larger than 1 ml capacity, and such a small gob of glass loses its heat rapidly and is difficult to mould. Also the surface finish inside a moulded tube is not smooth enough for this application, nor is the bore parallel. Drawn tubing, which has an excellent surface finish and form, is the preferred starting material, but current working methods, as described, do not provide control of both inside and outside dimensions.
Conventional glass hypodermic syringes are made on automatic lathes from glass by working heat-softened tube, as previously described. Low cost disposable glass syringes are generally made with the hollow needle glued into a precisely formed hole in one end of the syringe body. The manufacturing process is relatively primitive, with low production rates and high reject rates.
OBJECT OF THE INVENTION
The present invention seeks to overcome the drawbacks of current glass tube forming methods by providing a means of forming the orifice, and the inside and outside profiles of a needleless injector capsule or hypodermic syringe body, which means has excellent repeatability and is capable of high speed production.
SUMMARY OF THE INVENTION
According to the invention there is provided a method of making an article from a formable material, the article having a cavity communicating with the exterior via an orifice, wherein a blank having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool while an end region of the blank adjacent the said open end is in a condition to permit it to be formed, one of the said tools having a pin extending therefrom, and the said one tool and the other of said tools are brought together to form the said end region into a desired shape, with the pin defining the said orifice.
The invention further provides an apparatus for making an article from a formable material, the article having a cavity communicating with the exterior via an orifice, comprising a first forming tool for receiving an open-ended blank, and a second forming tool for engaging an end region of the blank adjacent the open end thereof to form the same, one of the said tools having a pin extending therefrom, the tools being so arranged that when they are brought together to form the said end region into a desired shape the pin defines the said orifice.
The pin can be on either of the forming tools, though in the embodiments described below it is preferably on the first forming tool.
In a preferred embodiment of the invention, a glass tube, cut to length, is placed onto a mandrel having a profile to which the glass may be formed. The mandrel has a pin at its extreme for forming the orifice. The glass is rotated and heated on the end to be formed. When it is at the optimum forming consistency, a form tool having a profile to which the outside of the tube is to be formed, is applied to the exterior of the glass tube and presses the softened glass onto the mandrel and pin. Immediately before forming, the rotation of the glass tube is stopped; alternatively the external forming tool is rotated at the same speed as the tube, so that there is no relative movement between the tube and external form tool.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention will now follow, with reference to the accompanying drawings, in which:
FIG. 1 shows a centreline section through a typical glass capsule, assembled to the nose of an actuator or power source;
FIG. 2 shows a glass tube placed on a mandrel, with external form tool adjacent;
FIG. 3 depicts the form tools in position having pressed the glass into the required shape;
FIGS. 4 and 5 show modified forming methods that will accommodate wide tolerance glass tube;
FIG. 6 shows a hypodermic syringe body;
FIGS. 7 a and 7 b show a further modified method of forming a capsule; and
FIGS. 8 a and 8 b show yet another modified method of forming a capsule.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, capsule 1 is a cylinder containing drug 2 , and a piston 3 in contact with drug 2 . The capsule 1 is retained in the nose 4 of a needleless injector actuator by retaining cap 5 bearing on shoulder 8 of the capsule 1 . Cap 5 may be retained by screw threads 10 , snap means or other suitable device. The discharge end of the interior of capsule 1 is characterised by a frusto-conical form 7 leading into the orifice 6 . When the injector is operated, a ram 9 biassed in direction Y is released so as to engage and drive the piston 3 to discharge the drug 2 through orifice 6 .
The ratio of the orifice length to diameter should be as small as practicable, and it is desirable that this should be no more than 2:1. This ratio has a significant effect on the flow resistance of the orifice: too high and the orifice resembles a tube with a corresponding increase in flow resistance. Typically, the orifice diameter may be within the range of 0.1 mm to 0.5 mm, with corresponding lengths within the range of 0.2 mm to 1.0 mm.
When performing an injection, the face 11 of the retainer 5 is pressed lightly on the patient's skin, and the area of face 11 provides sufficient support to prevent the injector capsule assembly sinking into the tissues. If the face 12 is flush or slightly behind face 11 , the orifice is in very light contact with the skin, and an intradermal injection will result; a firm contact—i.e. face 12 protrudes slightly from face 11 —will result in a subcutaneous injection; and if face 12 protrudes considerably from face 11 thereby displacing and compressing adipose tissue, then the injection may be intramuscular. This is, of course, a generalisation, since other factors such as pressure and orifice size may be adjusted to achieve the required injection characteristics. Nevertheless, the relationship of the capsule face and retainer face must be controlled to achieve repeatable high quality injections.
The purpose of the frusto-conical form 7 which joins the cylindrical section of capsule 1 to the orifice 6 is to reduce turbulent energy losses as the drug is forced into the orifice 6 , and also to minimise during injection the stresses within the glass walls of capsule 1 as the cylindrical bore reduces to the orifice 6 .
The foregoing description covers the essential design requirements of a needleless injector capsule: there may be small variations but the great majority of injectors use a capsule having a form similar to that described.
Referring now to FIG. 2, the material for the capsule 1 is a length of glass tube 1 a , which is located over mandrel 20 and rests on tube support 23 . The mandrel 20 has a frusto-conical form 7 a , terminating in a pin 21 . Located concentrically above the mandrel 20 is a form tool 22 , which has a forming surface 27 . A hole 24 in the form tool 22 is a close clearance fit relative to pin 21 .
The forming process commences by heating the tube 1 a in the area of the frusto-conical section 7 a of mandrel 20 to a temperature sufficient to soften the glass. Preferably, at least the mandrel 20 is rotated, (and more preferably the tube support 23 and mandrel 20 are rotated in unison, i.e. at the same speed and in the same direction), together with the glass tube 1 a , during heating, so that the temperature of the glass is evenly distributed. Alternatively, the parts may remain stationary, the glass being heated by a ring burner. When the optimum temperature is reached, the form tool 22 is pressed onto the softened glass as shown in FIG. 3, and thus shapes the glass tube 1 a to form the capsule 1 . This is done either with the support 23 and mandrel rotating together in unison, or with both stationary. The lengths of the orifice 6 and other features are controlled by the face 26 of the form tool 22 abutting face 25 of tube support 23 , but other stop means may be equally effective.
The process described and illustrated by FIGS. 2 and 3 is idealised and would require an exact volume of glass tubing to be presented to the form tool. In practice, the dimensional tolerances of glass tube are quite large, and even if an accurate bore tubing is specified, the variation in wall thickness results in a wide variation in the outside diameter. FIG. 4 shows a method of overcoming this problem. The form tool 22 a has a hole 24 a which is substantially larger in cross-section than the corresponding pin 21 a . This pin is shorter than the pin shown in FIG. 2 . In the illustration, hole 24 a is frusto-conical, and has a substantially larger cross-section than the pin 21 a at least for that length of the hole over which the pin extends. In other words, there is a substantial clearance between the pin and the surface defining the hole. The glass tube is cut so that the volume is slightly greater than required for the finished capsule, and during forming, any excess material is forced along hole 24 a to form a blob 40 , whereby the hole formed by pin 21 a is closed. After removing the formed tube from the mandrel and tube support, the blob 40 is cut at X—X and the cut face is flame polished to remove sharp edges and to smooth out any surface roughness. If necessary, after cutting, the face may be ground before flame polishing.
FIG. 5 shows another method of dealing with excess material. Again, the volume of the glass tube is slightly more than the finished capsule, and during forming, the excess glass is allowed to spread into the form tool to make a rim 50 , the length Z of which may vary according to the amount of excess glass. This method has the additional advantage that the diameter of the rim 50 is controlled, regardless of the wall thickness tolerance.
It is important that the orifice is formed without any glass “flash”, and whilst FIGS. 3 and 5 show pin 21 entered into hole 24 , the annular clearance between pin and hole must be very small to prevent the ingress of molten glass which would form a thin skin or “flash” across the orifice 6 . As a result, the alignment of the forming tool and mandrel is critical in FIGS. 3 and 5 to ensure that the pin 21 enters hole 24 without bending or jamming. This requires accurate and costly tools.
FIGS. 7 a and 7 b show a method of preventing flash formation around the orifice without the necessity of very accurate tool alignment. Plunger 60 is a sliding fit within forming tool 22 b and a compression spring 64 bears on plunger 60 which carries a collar 63 fixed thereto. The total sliding movement permitted is controlled by the faces of the collar 63 and abutment faces 65 and 67 within a cavity 66 in the forming tool 22 b . The mandrel 20 b carries a pin 21 b which has a flat distal face 62 , and plunger 60 has a flat distal face 61 . When the glass is formed, substantially as already described, the faces 61 and 62 cooperate to form a tight “shut-off” to prevent molten glass forming a thin skin over the end of the orifice in the capsule. The force of the shut-off is determined by the spring 64 .
FIGS. 8 a and 8 b show a similar arrangement, but in this case the pin 21 c is spring loaded by a compression spring 64 c and slides in mandrel 20 c . When the forming tool 22 c and the mandrel 20 c are brought together to form the glass, a face 70 of pin 21 c cooperates with a face 71 of the forming tool 22 c to form a tight shut-off.
The foregoing methods of forming the glass tube may be applied with equal efficacy to the production of glass syringes, as shown in FIG. 6 . In this case, the diameter of hole 100 may be required to be closely controlled to accept a hollow needle: the needle may be bonded into the glass with a minimum thickness of adhesive. Alternatively, the frusto-conical tip 200 may be dimensioned to accept a so-called Luer-fitting needle, i.e. a needle with an adaptor having a co-operating internal taper by which means the needle may be frictionally retained on the syringe tip.
The method of forming tubing to make needleless injector capsules and hypodermic syringes may be applied to materials other than glass where conventional forming methods are inappropriate. | A method and apparatus are described for making an article such as the body of a needleless injector capsule, from a formable material, such as glass, the article having a cavity communicating with the exterior via an orifice. A blank ( 1 a ) having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool ( 22 ) while an end region of the blank ( 1 a ) adjacent the open end is in a condition to permit it to be formed. One of the tools ( 7 a ) has a pin ( 21 ) extending therefrom, and when the tools are brought together to form the end region into the desired shape of the pin ( 21 ) defines the orifice. | 1 |
FIELD OF THE INVENTION
[0001] Generally, the field of art of the present disclosure pertains to a power feed entry circuit for telecommunication applications, and especially high power telecommunication applications, and more particularly, to a power feed entry circuit that includes hybrid active Or-ing and return current balance features.
BACKGROUND OF THE INVENTION
[0002] Some telecommunication (telecom) carriers now target a twenty percent power reduction per year for the equipment that they deploy. This is in response to increasing power consumption in central offices (COs), which is due to higher bandwidth capacities, increasing line card port densities, more intelligent processing requirements, more complex chip implementations, and the like. Higher power consumption equates to higher operating costs for telecom providers, and leads to more complex engineering challenges for equipment suppliers in dealing with thermal management, for example. Providers sometimes require equipment suppliers to conduct energy efficiency testing on the products that they purchase. For example, some providers require equipment suppliers to generate a Telecommunication Equipment Energy Efficiency Rating (TEEER). Other providers are waiting for the Alliance for Telecommunication Industry Solutions (ATIS) to complete an energy efficiency standard for products before they adopt a similar energy efficiency requirement standard. The more power a system draws with the data rate processed remaining the same, the lower the product is rated and the less competitive the product is.
[0003] High power telecommunication systems are typically made up of numerous subsystem modules that are required to meet various facility power interface requirements, including power feed and return isolation for the carrier-provided redundant power feeds and returns. The technique used to provide this isolation involves the enforcement of directional current flows on each of the individual feed and return paths, such that current from one feed source cannot flow in a reverse direction towards another feed source, with corresponding measures taken for the respective return paths. This technique is commonly referred to as Or-ing, and is based on the common reference for a diode topology that fulfills this requirement. Presently, there are two primary circuit designs available to product manufacturers that provide these feed and return Or-ing isolation functions for modules used in telecom applications, namely conventional passive diode Or-ing circuits and active Or-ing circuits.
[0004] Conventional passive diode Or-ing circuits include a diode placed in series with each source feed and return leg. These circuits are considered by most telecom power circuit designers to be very reliable, although they have significant associated power losses. Active Or-ing uses one or more power MOSFETs (metal-oxide-semiconductor field-effect transistors) with active Or-ing controllers in place of each series path diode. The present state-of-the-art active Or-ing approach is much more efficient, but has numerous limitations that present problems which must be overcome when considering high power, high availability telecomm applications. These challenges with the conventional active Or-ing include limited load capability, lack of adequate transient and fault immunity, high probability of traffic impact if an Or-ing subcircuit component failure occurs, and alarm indication issues. With respect to limited load capabilities, typical active Or-ing circuits are limited to less than 300 W. With respect to alarm indication issues, present state of the art active Or-ing circuits do not include a capability to detect negative feed fuse openings at controller inputs.
[0005] Conventional power entry circuits used for high power telecom modules use high power Schottky diodes in an Or-ing circuit configuration for the feed and corresponding return line isolation function, as this type of diode offers the lowest forward voltage drop and thus lowest losses for the conventional approach. Modern switching interface line modules switch up to 500 GB/s, resulting in per-module power loads often in excess of 500 W. The use of the latest technology (i.e. lowest voltage drop) diodes in such applications may result in a contribution to module power losses of over 12 watts (due to diode losses only) for a 500 W module and significant increases in the temperatures of both the printed circuit board (PCB) and environmental ambient. These temperature increases result in additional power losses for collocated high power components, such as field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and power conversion devices that may draw significantly more current at higher ambient temperatures. Operation of all of these components at elevated temperatures also reduces the device mean time between failures (MTBF) of the components, affecting system reliability and long term operational and replacement costs. In addition, the higher aggregate system module temperatures require an increase in system fan speed. Operation of fans at higher speeds further increases system power losses, as well as reduces the life of the fans, with additional impact to both system costs and MTBF. Thus, even with best-available Schottky diodes, the incurred dissipation becomes a competitive limitation for current generation high power telecom modules.
[0006] Another major limitation of the Or-ing diodes currently used for feed isolation is that if a failure occurs, such as a short circuit failure in one or more of the four diodes, there is no failure indication, as this condition is very difficult to detect and the loss of power bus feed isolation may be present, but undetected, with the potential for both EMC and safety compliance failures (including potential human safety hazards for service or operational personnel). If the diode failure occurs with any diode in an open circuit mode, then power is absent from the corresponding feed, possibly without indication to the system and, upon opposite feed removal, may be traffic-affecting. The present state-of-the-art active Or-ing circuits using MOSFETs have output load current capability that is limited to approximately 5 A, corresponding to significantly less than 300 W deliverable power per module. This 300 W limit is far less than that required for many applications. The present state-of-the-art active Or-ing circuits also do not contain adequate protection to prevent failure of controllers when exposed to line or load faults or transient feed voltages. The present state-of-the-art active Or-ing circuits further do not include features for negative feed fuse detection for the opening of fuses located at the MOSFET inputs. Many carriers require that all fuse failures be detected and reported though system alarms. The direct measurement of a failure of either negative feed fuse at the controller input is not detectable using any available negative controllers due to problems introduced by feedback within the negative controller devices. The present state of the art active OR-ing circuits do not include fail-safe power path circuitry such that power is not interrupted to the critical module circuitry in the event of a MOSFET open-circuit failure or MOSFET drive circuit failure. Additionally, state of the art circuits do not include means of return current power path control such that return current flows only back to the active source in the event that one of the two redundant input sources fails or is switched off at the CO.
BRIEF SUMMARY OF THE INVENTION
[0007] In an exemplary embodiment, a power feed entry circuit includes inputs coupled to redundant power feeds; outputs coupled to components on a module; a first circuit coupled to the inputs and the outputs, wherein the first circuit is configured for power connections, return isolation relays, diode Or-ing, and output fuse light emitting diodes (LEDs); a second circuit coupled to the first circuit, the inputs, and the outputs, wherein the second circuit is configured with a hot swappable controller and for common-mode and differential mode power line filtering; a third circuit coupled to the first circuit, wherein the third circuit is configured for alarm monitoring of the first circuit and the second circuit; and a fourth circuit coupled to the first circuit and the third circuit, wherein the fourth circuit comprises a dual feed high and low active field effect transistor Or-ing circuit; wherein the first circuit, the second circuit, and the fourth comprise high voltage and high current circuits, and wherein the third circuit comprises a high and low voltage and low current circuit. The power feed entry circuit is configured for loads in excess of 500 W with a corresponding power dissipation by the first circuit, the second circuit, and the third circuit of less than 2 W. The fourth circuit can include a plurality of Or-ing metal-oxide-semiconductor field-effect transistors (MOSFETs), and wherein the third circuit is configured to monitor voltage drops across the MOSFETs source-to-drain nets for comparison to programmed controller alarm voltage thresholds and for raising alarms based thereon. The third circuit can be configured to monitor a plurality of components in the first circuit, the second circuit, and the fourth circuit for operational status and for raising alarms based thereon. The fourth circuit can include a fail-safe alternate power path using power diodes connected in parallel across each MOSFET. The power diodes can be arranged in a hybrid parallel diode architecture that provides the capability of supplying power under power path component fault conditions. The first circuit can include an active power feed return current balance to isolate the return current when a feed is removed.
[0008] In another exemplary embodiment, a module for use in high powered telecom applications includes a board including a plurality of connectors to a backplane; and the power feed entry circuit coupled to some of the plurality of connectors for receiving power feeds and coupled to at least one component on the board for providing isolated power thereto. In yet another exemplary embodiment, a daughter board for use in a high powered telecom module includes a printed circuit board including the power feed entry circuit, wherein the printed circuit board is mounted on the high powered telecom module. This provides an added feature of modular replaceability in the event of a failure as well as board layout-efficiency benefits due to the daughter board providing extra component surface area over the main board.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0009] Exemplary and non-limiting embodiments of the present disclosure are illustrated and described herein with reference to various drawings, in which like reference numbers denote like method steps and/or system components, respectively, and in which:
[0010] FIG. 1 is a functional block diagram of a power feed entry circuit;
[0011] FIG. 2 is a circuit schematic of power connectors, return isolation relays, diode Or-ing, and output fuse LEDs;
[0012] FIG. 3 is a circuit schematic for a dual feed high and low active FET Or-ing circuit;
[0013] FIGS. 4-5 are circuit schematics of six status monitor circuits using optoisolators and LED for monitoring of active Or-ing FET, controllers, and fuses (both visible and electrical outputs are provided);
[0014] FIG. 6 is a circuit schematic of a relay status monitor circuit;
[0015] FIG. 7 is a circuit schematic of a relay fuse status monitor circuit;
[0016] FIG. 8 is a circuit schematic of the host module interface circuit connections.
[0017] FIG. 9 is a circuit schematic of a hot swap controller, including low voltage battery disconnect (LVD), overvoltage cutoff, and recovery functionality, as well as common-mode/differential mode (CM/DM) power line filtering;
[0018] FIG. 10 is a perspective view of an exemplary implementation of the power feed entry circuit; and
[0019] FIG. 11 is a perspective view of the power feed entry circuit installed on a host module.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In various exemplary embodiments, a power feed entry circuit, an active Or-ing module, and a daughterboard (collectively referred to herein as a power feed entry circuit) are described with hybrid active Or-ing, return current balance and fail-safe power path preservation features. The power feed entry circuit provides a unique, high-power active Or-ing implementation designed to meet the environmental, regulatory, reliability, and high-availability demands of a state-of-the-art telecom, datacom, etc. power-entry application. This power feed entry circuit provides high-power MOSFET-based active Or-ing for minimal power losses while maintaining fault tolerance through an innovative hybrid diode structure with a unique circuit implementation for both self-fault monitoring and maintenance of the critical power path in the event of a fault. In addition, the power feed entry circuit provides a level of monitoring functionality that would normally not be available in present state-of-the-art designs. The power feed entry circuit includes extensive protective features for robustness and reliability for sustained operation in the harsh telecom environment as well as active power feed return isolation for prevention of reverse current flow on non-energized input feeds. This design provides a uniquely-adapted implementation that addresses the compound demands of a telecomm carrier-grade power-entry solution. The power feed entry circuit is designed to provide failure indications and take up as little space as possible. The power feed entry circuit is designed to meet all customer compliance requirements including, without limitation, NEBS GR63, GR1089, GR-78 Issue 2, ATT-TP-76450 and ATT-TP-76200
[0021] Referring to FIGS. 1-9 , in an exemplary embodiment, a functional block diagram illustrates a power feed entry circuit 10 in FIG. 1 with associated circuit diagrams illustrated in FIGS. 2-9 . Specifically, the power feed entry circuit 10 can be a module or daughterboard that is used on another type of module to reduce the power loss associated with providing power feed isolation while maintaining reliability and providing alarm functions required for the intended applications including connections to Telecommunications Central Office power. Exemplary module types can include, without limitation, optical transceivers, switch modules (e.g., packet, time division multiplexed, combinations thereof, etc.), data line blades, control modules, etc. The power feed entry circuit 10 includes various functional components implemented in circuitry with each of the following functional components include inputs and/or outputs as −48 VDC/RTN (return) of about 15 A (denoted by lines 12 ), −48 VDC/RTN (return) of less than 1 A (denoted by lines 14 ), or low voltage of less than 1 A (denoted by lines 16 ). Further, each of the functional components can be classified as high voltage (denoted by white boxes), low voltage (denoted by black boxes), or both high and low voltages (denoted by gray boxes).
[0022] The power feed entry circuit 10 is wired to A & B feeds 20 for inputs and provides module DC/DC input 22 as outputs. Specifically, the feeds 20 can be redundant, A and B power feeds from a power device collocated with the power feed entry circuit 10 . The power device can provide two separate −48 VDC feeds to the power feed entry circuit 10 and can be referred to as a power distribution unit (PDU), a bank of batteries, generator, rectifier unit, etc. The module DC/DC input 22 provides return isolated power to its associated module or device. The power feed entry circuit 10 assembly is designed to reduce the power loss associated with providing the power feed isolation, filtering and hot swap control functions for telecom module assemblies that are at the load of the PDUs that supply modules with Negative 48 VDC Central Office power. The power feed entry circuit 10 is installed on the modules near the module backplane power connectors to serve as the interface circuit between the feed protection fuses and the module isolated DC/DC converter inputs as illustrated by the module block diagram in FIG. 1 . The power feed entry circuit 10 was also designed to provide failure indications, easy removal and take up as little space as possible. The power feed entry circuit 10 is field replaceable and uses parts meeting all requirements of the application specifications for safety and EMC including ATT-TP-76450, ATT-TP-76200 and GR-78 Issue 2.
[0023] The feeds 20 and the inputs 22 interface to a power nets and power inputs and outputs circuit 24 which connects to a power input distribution circuit 26 which connections to a return relay isolation and fuse circuit 28 which connects to a diode Or-ing circuit 30 which connects to an output fuse and light emitting diode (LED) circuit 32 . Each of the circuits 24 , 26 , 28 , 30 , 32 is a high voltage circuit with high current therebetween. FIG. 2 illustrates an exemplary circuit implementation of the circuits 24 , 26 , 28 , 30 , 32 , namely FIG. 2 is a circuit schematic of power connectors, return isolation relays, diode Or-ing, and output fuse LEDs. FIG. 2 includes both high current (e.g., 15 A) paths illustrated in bold lines and low current paths (e.g., <1 A) illustrated normally. FIG. 2 shows the power feed entry circuit 10 has inputs from the PDU such as via backplane (BP) connectors into a module hosting the power feed entry circuit 10 , and outputs providing isolated power to the module. Using the features shown in FIG. 2 , the circuit 10 provides A and B return bus balanced current flow with associated feeds for dual power source applications as required for ATT-TP-76200 compliance. FIG. 2 shows connections between the high power input circuit of modules and the disclosed circuits including the return isolation connections, parallel hybrid protection diodes as well as input to active Or-ing.
[0024] The return relay isolation and fuse circuit 28 connects to a fuse and sensor circuit 34 which connects to a bi-polar transient voltage suppressor (TVS) Zener diode circuit 36 which connects to an active FET Or-ing circuit 38 . Each of the circuits 34 , 36 , 38 is a high voltage circuit with high current therebetween. FIG. 3 illustrates an exemplary circuit implementation of the circuits 34 , 36 , 38 , namely FIG. 3 is a circuit schematic for a dual feed high and low active FET Or-ing circuit. FIG. 3 shows connections to the active Or-ing circuit inputs and outputs including controller alarm as well as fuse-fail detection circuits. Using the circuit features shown in FIG. 3 , the circuit 10 for the A and B feed −48V power and return connections for modules that present a total load in excess of 500 W for either feed present or with both feeds together.
[0025] The bi-polar fuse and sensor circuit 34 connects via low current to an alarm isolation and circuit status circuit 40 which is both a high and low voltage circuit. The alarm isolation and circuit status circuit 40 connects at low voltage to an active Or-ing circuit and fuse status output driver/LED circuit 42 . The circuits 40 , 42 are illustrated in an exemplary circuit implementation of FIGS. 4-5 . Specifically, FIGS. 4-5 are schematics of optoisolators and LED circuits for active Or-ing FET, controllers, and fuse status indication. FIG. 4 is the positive controller fuses and FIG. 5 is the negative controller fuses. Note, the circuits 40 , 42 are both high and low voltage with an isolation boundary between high voltage (HV) parts and low voltage (LV) parts. FIG. 4 is a positive control fault detection circuit with the LED being green, for example, unless there is an excessive FET drop or an input supply failure. FIG. 5 is a negative control fault detection circuit that has the LED normally off but the LED can be on, e.g. red, if the FET has failed in either a shorted or open mode.
[0026] The active Or-ing circuit and fuse status output driver/LED circuit 42 connects to an alarm control circuit 44 . The power input distribution circuit 26 and the return relay isolation and fuse circuit 28 connect via low current to a feed/relay monitor/fuse alarm isolation and circuit status circuit 46 . The feed/relay monitor/fuse alarm isolation and circuit status circuit 46 connects to a feed status output drivers, LED, and revision identification circuit 48 which connects to the alarm control circuit 44 . The alarm control circuit 44 can connect to a module control circuit 50 external to the circuit 10 such as on the module in which the circuit 10 is included. FIGS. 6-8 include exemplary circuit implementations of the circuits 44 , 46 , 48 . Specifically, FIG. 6 is a monitor relay out circuit, FIG. 7 is a relay fuses circuit, and FIG. 8 is a module control interface circuit. In FIGS. 6-8 , the high voltage components form the high voltage part of the circuit 46 and the low voltage components form the low voltage circuits 44 , 48 .
[0027] The output fuse and LED circuit 32 connects to a differential mode (DM) electromagnetic interference (EMI) filter circuit 52 which connects to an output common mode (CM) EMI filter circuit 54 which connects to an output filter capacitor circuit 56 . FIG. 9 illustrates an exemplary circuit implementation of the circuits 52 , 54 , 56 each of which is a high voltage circuit. Further, high current is illustrated in FIG. 9 with bold lines. FIG. 9 is a hot swappable CM/DM power line filter, overvoltage cutoff, and low voltage battery disconnect (LVD) and recovery circuit.
[0028] In the event of an active Or-ing circuit failure (such as a shorted MOSFET, controller or other active Or-ing component), the power feed entry circuit 10 provides a visual LED indication as well as isolated alarm signals to its associated module while still delivering power to the module through the parallel Or-ing diodes. The alarms and status LED can be displayed on the front of the module with various green/red LEDs for positive controller, negative controller, A & B return, A & B relays, and A & B monitoring. Thus, the power feed entry circuit 10 eliminates the potential for silent failure as noted with failed diodes present in conventional high power modules. This prevents optical data interruption as well as Electromagnetic Compatibility (EMC) and safety compliance failures. The power feed entry circuit 10 includes features for Reverse Power Connection Protection.
[0029] Referring to FIGS. 10-11 , in an exemplary embodiment, perspective views illustrates an exemplary implementation of the power feed entry circuit 10 as a daughterboard or plug in module to another module 100 . Specifically, FIG. 10 is a perspective view of the power feed entry circuit 10 , and FIG. 11 is a perspective view of the power feed entry circuit 10 on the module 100 . The components used in the power feed entry circuit 10 take up less than 3 square inches of PCB space and are less than 1 inch tall including the heat sink. In FIG. 10 , the circuit 10 includes a PCB 102 with the various circuits and components described in FIGS. 1-9 contained thereon. The circuit 10 includes various hardware for mounting to the module 100 as well as heat sinks The hardware can include retainer plates 104 with retainer screws 106 received therethrough, mounting and heat sink material 108 , and thermal interface material 110 . Mounting screws 112 mount the circuit 10 to the module 100 via the material 108 and mounting standoffs 114 . As described herein, the module 100 can be a high-powered telecom or datacom device. It may also be any computing device. The module 100 also includes a PCB 120 on which the circuit 10 is mounted. The module 100 can include backplane connectors 130 which can include power connectors 132 . The circuit 10 is configured to connect to the power connectors 132 via the PCB 120 and to provide isolated DC/DC power to other components (not shown) on the module 100 .
[0030] The unique advancements achieved and problems resolved by the power feed entry circuit 10 include the following:
[0031] 1. Present state-of-the-art diode Or-ing circuits dissipate in excess of 12 W when supporting loads up to 500 W while the active Or-ing circuit components in the power feed entry circuit 10 dissipate less than 2 watts. The active Or-ing circuits described herein incorporate features that provide dual feed interface circuits that support loads greater than 500 W with either one or both of the feeds present and result in a greater than 85% reduction in Or-ing function power loss as compared to conventional approaches. The Or-ing function power loss alone may correspond to an approximate 400 W reduction in worst case application diode power for a typical telecom system comprised of multiple modules as described. The collocated component power loss reduction, as well as the fan speed reduction associated with the disclosed circuit usage further contribute to the reduction in the total power loss.
[0032] 2. Present state-of-the-art diode Or-ing circuits do not have the capability to detect failed components while the active Or-ing circuit described in the power feed entry circuit 10 detects failed components and issues alarms. The circuit 10 monitors the performance and operational health of all four Or-ing MOSFETs by monitoring the voltage drops across the MOSFET drain-to-source nets and comparing these to programmed controller alarm voltage thresholds. The various other circuit characteristics of most critical circuit components including controllers, alarm interface devices, and transient protectors are also monitored and ported to the alarm circuits. If a failure occurs with the active Or-ing circuit, a system alarm is issued. If the failure results in the interruption of a MOSFET power path, the circuit 10 includes a failsafe alternate power path using power diodes connected in parallel across each MOSFET. Thus, the design approach of the circuit 10 overcomes several of the greatest limitations of present state-of-the-art circuits by issuing comprehensive alarms in the event of a failure while reliably maintaining the load power path under fault conditions. This unique combination of features provided by this hybrid protection scheme is not found in other state-of-the-art Or-ing circuits.
[0033] 3. Present state-of-the-art diode Or-ing circuits result in ambient temperature rise and PCB temperature rises in excess of 60 C when supporting loads of 500 W. This excessive temperature rise causes other components on the same PCB to experience a temperature rise as well and requires system fans to run faster for cooling. These problems further increase the system power loss as well as reduced the system reliability due to shorter fan life and component aging. The active Or-ing circuit components in the power feed entry circuit have a much lower temperature rise that is less than 20 C under a 500 W load condition. Also, the temperature rise of the disclosed active Or-ing transistors as well as the controllers is not significant with loads above 500 W even under single feed conditions when compared to diode Or-ing.
[0034] 4. Present active MOSFET Or-ing circuits do not contain circuitry to prevent return path current flow when the corresponding feed is removed while the power feed entry circuit 10 provides this capability. The circuit 10 contains additional features for power feed return isolation and current flow balancing. These features assure that no current flow may occur on the power return path when the corresponding feed source is not present. The lack of this circuit that isolates return current flow when one feed is removed may present safety requirement compliance concerns (see ATT-TP-76200), including current overload in source-to-source potential-equalizing wiring, which may not be adequately rated to support the source-to-load current level. The circuit 10 incorporates an active power feed return current balance feature to isolate the return current when a feed is removed. This feature includes transient protection to assure reliable operation in all application environments.
[0035] 5. Present state-of-the-art active Or-ing circuits can only support loads of less than 300 W while the power feed entry circuit 10 can support over 500 W loads. The present state-of-the-art active Or-ing circuits using MOSFETs have output load current capability that is limited to approximately 5 Amps, corresponding to significantly less than 300 W deliverable power per module. This 300 W limit is far less than that required for many applications. The circuit 10 has proven to be effective and reliable when powering loads in excess of 500 W under all intended application operating conditions. This is achieved though the unique use of low RDS(on) MOSFETs in combination with ballast resistive networks and fuses in combination with the connections to the active Or-ing controller control and alarm circuits.
[0036] 6. Present state-of-the-art active Or-ing circuits lack adequate transient and fault immunity to prevent component damage when subjected to line side surge and/or transient conditions as well as line or load side faults per regulatory telecomm compliance standards. The power feed entry circuit 10 is very robust and has been subjected to faults as required for Network Equipment-Building System (NEBS) GR1089 compliance as well as all required line surge, transient or EFT tests at levels including in excess of 500V without any component damage. The circuit 10 contains line and load electrical filter circuits using custom magnetic parts to limit both differential and common mode conducted emission levels that could be present. The circuit 10 also has transient and fault protection devices to prevent all component hard failures that may occur when the circuit is subjected to events required for compliance with potential carrier application requirements. In addition, the circuit 10 includes features to process all associated alarm features and provide visual, as well as software driven, indications of any problems.
[0037] 7. Present state-of-the-art active Or-ing circuits lack the ability to provide power to the load in the event of a component failure while the circuit 10 has a hybrid parallel diode architecture that provides the capability of supplying power under power path component fault conditions. The power feed entry circuit 10 includes the negative fuse fail detection capability that provides fuse fail detection of the fuses needed to isolate the MOSFET circuit from the corresponding parallel diode circuit. Many telecom providers, carriers, etc. require that all fuse failures be detected and reported though system alarms. The direct measurement of a failure of either negative feed fuse at the controller input is not detectable using any available negative controllers due to problems introduced by feedback within the negative controller devices. One potential approach to this problem is to not use fuses at the negative controller MOSFET inputs, but to locate the fuses on the line side of the MOSFET feed nets, but in that case a feed fuse failure (such as one caused by a shorted MOSFET or controller chip) would cause the parallel diode to also be removed from the circuit and therefore would eliminate the advantages of the hybrid protection scheme provided by the parallel diodes. An alternative approach is the use of GMT fuses to detect negative controller feed fuse failures, but this approach requires an excessive PCB board area and relatively expensive components. Thus, the negative fuse fail detection circuit in the circuit 10 uses unique rail-to-rail comparator circuits in combination with protection circuits that interface through the negative controller to detect the opening of either of the miniature feed protection fuses.
[0038] Although the present disclosure has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present disclosure and are intended to be covered by the following claims. | A power feed entry circuit, a module with the power feed entry circuit, and a daughter board with the power feed entry circuit include a first circuit coupled to inputs and outputs, wherein the first circuit is configured for power connections, return isolation relays, diode Or-ing, and output status-indication light-emitting diodes (LEDs); a second circuit coupled to the first circuit, the inputs, and the outputs, wherein the second circuit is configured with a hot swappable controller and provides common-mode and differential mode power line filtering; a third circuit coupled to the first circuit, wherein the third circuit is configured for alarm monitoring of the first circuit and the second circuit; and a fourth circuit coupled to the first circuit and the third circuit, wherein the fourth circuit comprises a dual feed high and low active field effect transistor Or-ing circuit. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the United States national phase of International Application No. PCT/EP2014/050474 filed Jan. 13, 2014, and claims priority to German Patent Application No. 10 2013 101 132.2 filed Feb. 5, 2013, the disclosures of which are hereby incorporated in their entirety by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a method for the hot-dip coating of metal strip, in particular steel strip, in a metallic melting bath, in which method the metal strip to be coated is heated in a continuous furnace and is introduced into the melting bath through a snout which is connected to the continuous furnace and which is immersed into the melting bath.
Description of Related Art
The hot-dip coating of metal strip, in particular steel strip, is a method that has been known for many years for the surface finishing of fine sheet-metal strip in order to protect it against corrosion. FIG. 3 illustrates, in a vertical sectional view, a section of a conventional installation for the hot-dip coating of a metal strip 1 . A steel strip (fine sheet-metal strip) which is to be correspondingly finished is, for this purpose, initially cleaned, and subjected to recrystallization annealing, in a continuous furnace 2 . Subsequently, the strip 1 is subjected to hot-dip coating by being led through a molten metal bath 3 . As coating material for the strip 1 , use is made for example of zinc, zinc alloys, pure aluminum or aluminum alloys.
The continuous furnace 2 typically comprises a directly heated preheater and indirectly heated reduction and holding zones, and also downstream cooling zones. At the end of the cooling zone, the furnace 2 is connected via a port (snout) 6 to the melting bath 3 . A diverting roller (Pott roller) 7 arranged in the melting bath 3 causes the strip 1 entering the melting bath from the snout 6 to be diverted into a substantially vertical direction. The layer thickness of the metal layer which serves for anti-corrosion protection is normally set by way of stripping jets 5 .
As a steel strip 1 passes through the melting bath 3 , an alloy layer composed of iron and the coating metal is formed on the surface of the strip. Above this, the metal layer is formed whose composition corresponds to the chemical analysis of the metal melt situated in the melting bath vessel 4 .
Depending on the melt composition, the coating has different characteristics, in particular with regard to mechanical and anti-corrosion protection characteristics. Also, the melt composition has an influence on the reliability of a process with regard to surface quality of the coated strip. In practice in the prior art, it is therefore the case that a corresponding composition of the metallic melting bath is selected in a manner dependent on the desired characteristics, that is to say, with a compromise solution, there is always a balancing act between the requirements such as, for example, the mechanical characteristics for the subsequent deformation of the coated fine metal sheet with the avoidance of cracks in the coating or peeling of said coating, on the one hand, and reliable anti-corrosion protection, on the other hand.
SUMMARY OF THE INVENTION
The present invention is based on the object of improving a method of the type mentioned in the introduction such that, with said method, the requirements placed on the coated strip with regard to good deformability of the strip or of a blank produced therefrom, as far as possible without cracking and peeling, and with regard to high anti-corrosion protection can be satisfied in an, as it were, effective and reliable manner.
To achieve said object, a method having the features of claim 1 is proposed. Preferred and advantageous embodiments of the method according to the invention are specified in the subclaims.
The method according to the invention is characterized in that, in the region delimited by the snout, a melt is used which is intentionally implemented differently, in terms of its chemical composition, than the chemical composition of the melt used in the melting bath. The invention thus proposes that melts of different composition (analysis) be used in the region delimited by the snout and in the rest of the melting bath. In this way, it is possible to set particular desired alloy coating characteristics in a highly variable and reliable manner.
It has been recognized by the inventors that, through the supply of alloy substances or correspondingly enriched coating metal directly into the port defined by the snout, it is possible for the melt composition in the port to be decoupled from the melt composition in the rest of the melting bath vessel. For example, it is the case here that the melt in the snout has a composition (analysis) which permits good mechanical deformability, whereas the melt in the rest of the melting bath vessel has a composition (analysis) which yields a good corrosion-resistant top layer.
A further advantage of the invention consists in that, owing to the relatively small volume of the melt in the snout and the process-induced consumption of said volume, the composition of the melt in the snout can be adapted or varied within a very short reaction time.
In this context, a preferred embodiment of the method according to the invention provides that the concentration of at least one chemical constituent of the melt used in the snout is monitored, and the chemical composition of said melt is adapted to a target value of the chemical composition in a manner dependent on the result of the monitoring. Said monitoring and the adaptation of the chemical composition of the melt are preferably performed automatically by means of a suitable monitoring and dosing device.
A further advantageous embodiment of the method according to the invention is characterized in that, as a snout, use is made of an elongated snout which ends at a distance in the range from 100 mm to 400 mm, preferably 100 mm to 300 mm, from the shell surface of a diverting roller which is arranged in the melting bath and which causes the strip entering the melting bath from the snout to be diverted into a substantially vertical direction. In this way, the melt that is supplied to the snout or used therein can be more reliably decoupled from the melt used in the rest of the melting bath vessel, giving rise, in the snout, to a volume region of at least adequate size in which the melt that is supplied or used there does not mix with the different melt used in the rest of the melting bath vessel.
A further advantageous embodiment of the method according to the invention provides that, as a snout, use is made of a snout whose immersed section is equipped with a narrowing portion and/or whose inner width or inner height tapers, at least over a length segment, in the direction of an outlet opening. In this way, too, the melt that is used in the snout can be decoupled from the melt used in the rest of the melting bath vessel, such that at least a volume region of adequate size of the melt supplied to the snout substantially does not mix with the different melt used in the rest of the melting bath vessel.
The elongated snout, which tapers in the direction of the outlet opening at least over a length segment, has the effect in particular of increasing the turbulence of the melt at and close to the metal strip. This turbulence promotes the decoupling of the melt that is supplied to the snout from the different melt used in the rest of the melting bath vessel.
To prevent an excessive amount of the melt that is used in the snout from being introduced into the rest of the melting bath, or to prevent mixing of the different melts, a further embodiment of the method according to the invention provides that, as a snout, use is made of a snout whose immersed section is equipped with a separating device or seal which prevents mixing of the melt situated in the snout and of the melt situated in the melting bath.
An advantageous embodiment of the method according to the invention is characterized in that an aluminum alloy comprising silicon is used as a melt in the region delimited by the snout, whereas a melt composed of pure aluminum is used in the melting bath. The pure aluminum in the melting bath is free from silicon, aside from inevitable impurities. In this way, it is possible to realize a hot-dip coated product, in particular steel strip, which firstly has a relatively thin alloy layer and is thus adequately ductile even for relatively intense deformations, and which secondly exhibits excellent corrosion resistance owing to the cover coating of pure aluminum.
Another advantageous embodiment of the method according to the invention consists in that an aluminum-zinc alloy comprising silicon is used as melt in the region delimited by the snout, whereas an aluminum-zinc alloy with a relatively reduced silicon content, or without silicon, is used as melt in the melting bath. In this way, too, it is possible to realize a hot-dip coated product, in particular steel strip, which, owing to the addition of silicon, has a relatively thin alloy layer and is thus adequately ductile for relatively intense deformations, and which exhibits excellent corrosion resistance owing to the surface layer formed from an aluminum-zinc alloy with reduced silicon content, or without silicon. If, in this case, an aluminum-zinc alloy without silicon is used as melt in the melting bath, it is self-evident that said melt is free from silicon aside from inevitable impurities.
A further advantageous embodiment of the method according to the invention is characterized in that a zinc-magnesium alloy is used as melt in the melting bath, whereas a zinc-magnesium alloy with a relatively reduced zinc, aluminum and/or magnesium content is used as melt in the region delimited by the snout. In this way, it is possible to realize a hot-dip coated metal strip, in particular steel strip, which is distinguished by particularly high surface quality and good mechanical deformability.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be discussed in more detail below on the basis of a drawing, which illustrates several exemplary embodiments. In the drawing, in each case schematically:
FIG. 1 shows a vertical sectional view of a melting bath vessel with an elongated snout, a diverting roller and a stabilizing roller;
FIG. 2 shows a further exemplary embodiment of a device according to the invention, having a melting bath vessel, which is illustrated in vertical section, and two stabilizing rollers arranged therein;
FIG. 3 shows a device for the hot-dip coating of metal strip as per the prior art, in a vertical sectional view;
FIG. 4 shows a sub-region of a melting bath, with an indication of flow conditions in the case of a device according to the invention in the region of a snout elongation piece;
FIG. 5 shows a melting bath of a device for the hot-dip coating of metal strip as per the prior art;
FIG. 6 shows a melting bath of a device according to the invention for the hot-dip coating of metal strip;
FIG. 7 shows a cross-sectional view of a section of a steel strip coated by immersion in an AlFeSi melt;
FIG. 8 shows a cross-sectional view of a section of a steel strip coated by immersion in a pure aluminum melt; and
FIG. 9 shows a cross-sectional view of a section of a metal strip coated by immersion in two different metallic melts.
DESCRIPTION OF THE INVENTION
In the exemplary embodiments, illustrated in FIGS. 1, 2 and 4 , of a device according to the invention for the hot-dip coating of metal strip, in particular steel strip, the snout 6 of a generic coating installation, which may correspond or corresponds substantially to the coating installation as per FIG. 3 , is designed such that the immersed section of the snout 6 can have coating material B and/or at least one alloy additive LZ supplied to it separately. The device according to the invention is thus designed such that, in the region delimited by the snout 6 , a melt can be implemented or used which is implemented differently, in terms of its chemical composition, than the chemical composition of the melt used in the melting bath 3 .
For this purpose, the snout 6 is preferably equipped with a shaft-shaped snout elongation piece 6 . 1 for increasing the snout immersion depth. The snout elongation piece 6 . 1 has an attachment section 6 . 11 into which the lower end of the snout 6 projects. The attachment section 6 . 11 has a basin- or trough-shaped receiving chamber 6 . 12 , the encircling side wall of which is fastened to a support 6 . 13 mounted on the upper edge of the melting bath vessel 4 . In the base of the attachment section 6 . 11 or receiving chamber 6 . 12 , there is formed an elongate opening 6 . 14 through which the metal strip 1 to be coated runs into the shaft-shaped snout elongation piece 6 . 1 .
The snout 6 or the snout elongation piece 6 . 1 is preferably designed such that its clear inner width or clear inner height tapers toward the outlet opening 6 . 15 at least over a length segment. The tapering of the inner width or inner height arises from the fact that the walls 6 . 16 , 6 . 17 , facing toward the top side and bottom side of the strip 1 , of the snout 6 or snout elongation piece 6 . 1 converge in the direction of the outlet opening 6 . 15 . The inner width or inner height of the snout or snout elongation piece 6 . 1 is preferably characterized, in these exemplary embodiments, by a continuous tapering.
The outlet opening 6 . 15 , or narrowest point of the snout elongation piece 6 . 1 , preferably has a clear inner width of at most 120 mm, particularly preferably at most 100 mm. Furthermore, the snout elongation piece 6 . 1 is dimensioned so as to end at a distance A in the range from 100 mm to 400 mm, preferably 100 mm to 300 mm, from the shell surface of the diverting roller 7 . The distance A between the lower end of the snout elongation piece 6 . 1 and the shell surface of the diverting roller 7 amounts to for example approximately 200 mm.
As is known per se, the diverting roller 7 is assigned a stabilizing roller 8 in order to ensure that the strip 1 passes in flat form, and in vibration-free fashion, through the flat jets 5 , of the jet stripping device, arranged above the melt bath. The support arms of the diverting roller 7 and of the stabilizing roller 8 are denoted in FIG. 1 by 7 . 1 and 8 . 1 . Furthermore, the stabilizing roller 8 may be combined with a guide or pressing roller 9 which is likewise arranged so as to be immersed (cf. FIG. 2 ).
In the exemplary embodiments of the device according to the invention illustrated in FIGS. 1 and 2 , the attachment section 6 . 11 of the snout elongation piece 6 . 1 and the snout 6 define at least one feed duct 6 . 18 via which coating material B and/or at least one alloy additive LZ can be supplied separately into the immersed section of the snout 6 and/or into the snout elongation piece 6 . 1 .
The elongation, according to the invention, of the snout 6 serves to realize the most extensive possible decoupling of the melt that is implemented or used in the snout 6 from the melt that is implemented/used in the rest of the melting bath vessel 4 , which differs in terms of its chemical composition from the melt that is implemented/used in the snout 6 . This gives rise, in the melting bath 3 , to regions with different melt compositions, in order to implement particular desired alloy coating characteristics. This will be discussed in more detail below with reference to FIGS. 7 to 9 .
In the case of conventional hot-dip coating of steel strip with an aluminum melt which comprises approximately 10 wt % silicon, a relatively thin alloy layer 11 is formed at the interface between steel and coating metal ( FIG. 7 ). The thickness of the alloy layer 11 amounts to for example approximately 4 μm. The alloy layer 11 is followed by the surface layer 12 , situated thereabove, composed of aluminum and ferrosilicon inclusions. This coating, known under the trade name FAL type 1 ,is, owing to the thin alloy layer 11 , ductile enough to permit satisfactory realization of desired deformations of the coated steel strip 1 or steel sheet. The anti-corrosion protection realized by means of this coating is however not as good as that realized in the case of a pure aluminum coating, with the trade name FAL type 2 .
FIG. 8 shows a cross-sectional view of a section of a steel strip 1 coated by immersion in a pure aluminum melt. This lining provides excellent anti-corrosion protection. 12 ′ denotes the surface layer composed of pure aluminum. Owing to the absence of silicon in the melt, a relatively thick alloy layer 11 ′ forms at the interface between steel and coating metal. The thickness of the brittle alloy layer 11 ′ may in this case amount to for example up to 20 μm. The brittle alloy layer 11 ′ exhibits a tendency for crack formation, and for peeling of the metal coating, during the deformation of the coated steel strip 1 or steel sheet. Owing to the restricted ductility, this product (FAL type 2 ) is suitable only for simple components which do not require any intense deformations.
The device according to the invention illustrated in FIG. 1 or FIG. 2 , in which the snout 6 and the attachment section 6 . 11 of the snout elongation piece 6 . 1 define at least one feed duct 6 . 18 , makes it possible, for example, to enrich a melt comprising silicon in the snout 6 , leading to a thin alloy layer 11 similar to the alloy layer of the product FAL type 1 . For example, an AlFeSi coating material may be supplied to the snout 6 via the basin-shaped attachment section 6 . 11 of the snout elongation piece 6 . 1 and the feed duct 6 . 18 . By contrast, it is preferably the case that a pure aluminum melt is used in the melting bath vessel 4 itself, such that a surface layer 12 ′ composed of pure aluminum is obtained. This product (“FAL type 3 ”), which is depicted in FIG. 9 , combines the advantages of the products FAL type 1 and FAL type 2 . This is because, in this way, a product is obtained which, owing to the thin alloy layer 11 , is ductile enough that desired relatively intense deformations can be realized, and which, furthermore, owing to the surface layer 12 ′ composed of pure aluminum, exhibits excellent anti-corrosion protection characteristics.
Instead of a pure aluminum melt, it is also possible for some other metallic melt to be used in the melting bath vessel 4 . For example, an aluminum-zinc melt may be used in the melting bath vessel 4 , whereas, in the region delimited by the snout 6 , a melt is used which is likewise based on an aluminum-zinc melt but which additionally has, or has had, silicon added to it for the purpose of suppressing or reducing the alloy layer, whereby improved deformability is attained.
A further example for the use, according to the invention, of melts with different chemical compositions is the use of a zinc-magnesium melt in the melting bath vessel 4 , whereas a melt with reduced zinc, aluminum and/or magnesium content is used in the snout 6 . In this way, it is possible to reduce instances of insufficient wetting in the coating of the strip 1 , and thus to improve the surface quality of the hot-dip coated strip.
In the case of prior art coating systems as per FIG. 3 , it is sometimes the case that slag 10 accumulates on the surface of the melt 3 within the snout 6 , which slag can lead to flaws in the coating of the metal strip 1 . Tests have shown that such slag-induced coating flaws can be prevented by increasing the depth of immersion of the snout 6 in conjunction with a tapering of the inner width or inner height of the immersed snout elongation piece 6 . 1 toward the outlet opening 6 . 15 . The tapering of the snout elongation piece 6 . 1 in the direction of the outlet opening 6 . 15 furthermore contributes to the decoupling of the different melts that are used in the snout 6 and in the rest of the melting bath vessel 4 .
In FIGS. 5 and 6 , the speed distribution of the melt flow encountered in the melting bath vessel during the operation of a prior art coating device ( FIG. 5 ) and during the operation of a coating device according to the invention ( FIG. 6 ) is depicted. A comparison of FIGS. 5 and 6 shows that, by means of the snout elongation 6 . 1 , the flow in the snout 6 , in particular in that region 3 . 1 of the melting bath surface enclosed by the snout 6 , is intensified, which results in a continuous exchange of the melt at the melting bath surface in the snout 6 . In this way, no slag, which causes surface flaws in the coating of the strip 1 , can accumulate in that region 3 . 1 of the melting bath surface which is enclosed by the snout 6 .
The embodiment of the invention is not restricted to the exemplary embodiments illustrated in the drawing. Rather, numerous variants are conceivable which make use of the invention specified in the appended claims even in the case of a different design. For example, it also falls within the scope of the invention for the inner width or inner height of the immersed snout elongation piece 6 . 1 to taper in the direction of its outlet opening 6 . 15 at least over a length segment in stepped form by way of one or more step changes in inner width or inner height, and/or by way of snout wall sections which are angled differently relative to one another. The snout elongation piece 6 . 1 may for example be assembled from multiple walls or wall sections which face toward the top side and bottom side of the strip 1 . The (continuous) tapering of the inner width or inner height of the snout elongation 6 . 1 may thus also extend only over a length segment thereof. | A method for the hot-dip coating of metal strip, in particular steel strip, in a metallic melting bath ( 3 ) is disclosed. In the method, the metal strip ( 1 ) to be coated is heated in a continuous furnace ( 2 ) and is introduced into the melting bath ( 3 ) through a snout ( 6 ) which is connected to the continuous furnace and which is immersed into the melting bath. To be able to satisfy the requirements placed on the coated strip ( 1 ) with regard to good deformability of the strip, as far as possible without cracking and peeling, and with regard to high anti-corrosion protection in a more effective and reliable manner, the disclosure proposes that, in the region delimited by the snout ( 6 ), a melt is used which is intentionally implemented differently, in terms of its chemical composition, than the chemical composition of the melt used in the melting bath ( 3 ). | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to production of principally hydrocarbon liquid and low molecular weight gaseous hydrocarbon products from organic carbonaceous solids by countercurrent flow of hydrogen-containing gas with the solids through a reactor, the solids passing sequentially through a preheat and pretreatment zone, a reaction zone and a hydrogen-containing gas preheat zone. Hydrocarbon liquid and low molecular weight gaseous hydrocarbon products, particularly useful as fuels, may be produced from organic carbonaceous materials such as oil shale, coal, peat and biomass.
2. Description of the Prior Art
The worldwide energy shortage has encouraged consideration and improvement of various processes for production of hydrocarbon fuels which do not involve petroleum products. Non-petroleum materials such as oil shale, coal, peat and biomass represent a large potential energy resource.
The production of hydrocarbon fuels by hydroconversion of oil shale has been known. For example, U.S. Pat. No. 4,003,821 teaches production of liquid hydrocarbons from oil shale by passing a hydrogen-rich gas stream countercurrent to a packed moving bed or fluidized bed of oil shale particles. The '821 patent teaches use of hydrogen sufficient to meet chemical requirements and the desirability of a sufficient excess of hydrogen to convert all of the hydrocarbons and carbon monoxide produced to methane. U.S. Pat. No. 3,922,215 teaches production of liquid hydrocarbons from oil shale by passing a hydrogen-rich gas stream in contact with oil shale particles in a moving bed. The '215 patent teaches the preferability of passing the hydrogen-rich gas stream in cocurrent relation with the oil shale particles to avoid condensation of hydroretorted liquids. The problems of condensation of liquids on the solid particles has been recognized by the prior art, for example, in U.S. Pat. No. 3,619,405. U.S. Pat. Nos. 3,891,403 and 3,929,615 teach production of high methane content gas from oil shale by hydrogasification.
Several patents teach various methods of retorting hydrocarbonaceous solids utilizing moving solids beds wherein gas passes countercurrently, such as U.S. Pat. Nos. 3,841,992; 3,619,405; 3,503,869; 2,899,365 and 3,297,562.
Free fall oil shale hydrogasification is taught by U.S. Pat. No. 3,421,868. The '868 patent teaches production of relatively high Btu gas from oil shale by passing freely falling oil shale in contact with hydrogen which is passed either cocurrent with or countercurrent to the free falling shale. The '868 patent teaches the desirability of low hydrogen to shale ratios and flow rates of hydrogen gas much lower than flow rates of shale solids, resulting in much longer gas residence time than solids residence time within the reactor. The process of the '868 patent does not require heat input to the reaction zone. The '868 patent teaches that the disclosed free falling shale process substantially reduces decomposition of mineral carbonates while providing substantially the same gaseous yield as previous moving bed processes.
U.S. Pat. No. 4,012,311 teaches a process for high yield of coal tars by contacting coal in a series of free fall reaction zones with a cocurrent flow of hydrogen followed by quick quenching and removal of coal tar prior to entry to the next reaction zone. The '311 patent teaches low hydrogen to coal ratios and the importance of very rapid heat-up, short residence time, and quenching.
SUMMARY OF THE INVENTION
This invention relates to a process for increased production of liquid and gaseous hydrocarbons from solid organic carbonaceous materials of the type having a sufficiently high density, such as oil shale, coal, peat and biomass, to free fall in a lean solids stream countercurrent to a hydrogen-containing gas stream. The liquid and gaseous hydrocarbon products formed according to the process of this invention are especially suitable for fuels. The process of this invention involves the solid organic carbonaceous material passing in free fall countercurrent flow relation to hydrogen-containing gas sequentially through a preheat and pretreatment zone, a reaction zone, and a hydrogen-containing gas preheat zone. A high hydrogen to organic carbon ratio of about 10 to about 30 Standard Cubic Feet of hydrogen per pound of carbonaceous material is maintained in the reaction zone, providing a lean solids stream. Further, short gas residence times, as compared to solid residence times, are provided by the hydrogen-containing gas moving countercurrently to the organic carbonaceous solids at a higher flow rate than the solid material. A solids residence time in the reaction zone of about 20 to about 200 seconds at temperatures of about 800° to about 2000° F. predominately forms the desired liquid and gaseous hydrocarbon products which are removed from the upper portion of the vertical reactor vessel and the spent carbonaceous material is removed from the lower portion of the reactor vessel. For preferential liquid production, the reaction zone temperatures are about 800° to about 1300° F. and for preferential gas production about 1400° to about 2000° F.
The process of this invention in one embodiment provides that the solid organic carbonaceous material and the hydrogen-containing gas is introduced at about ambient temperatures. The problems of liquid condensation and clogging previously encountered in moving bed reaction processes, is considerably reduced or eliminated in the process of this invention, thereby providing a higher useful yield of the more desired saturated liquid hydrocarbon products. Variation of process conditions within specified limits provides for utilization of a wide variety of organic carbonaceous containing feed solids.
It is an object of this invention to provide a process for production of liquid and gaseous hydrocarbons from solid carbonaceous materials having a sufficiently high density to free fall in a lean solids stream countercurrent to a hydrogen-containing gas stream by passing the carbonaceous material in free fall countercurrent flow relation to hydrogen-containing gas in a single vertical reactor.
It is another object of this invention to provide a process for production of liquid hydrocarbon products from heavy organic carbonaceous materials in a free fall countercurrent flow reactor free from clogging problems experienced in prior moving bed reactors.
It is yet another object of this invention to provide a process for production of liquid fuels from carbonaceous materials in which prior problems of liquid condensation in moving bed reactors is greatly reduced or eliminated.
These and other objects and advantages will become apparent upon reading the detailed description of preferred embodiments with reference, to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a reactor vessel according to one embodiment of this invention and suitable for carrying out the process of this invention; and
FIG. 2 is a cross-sectional view of the upper portion of a reactor of another embodiment for use in the process of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Carbonaceous materials useful as feed materials in this invention are solid organic carbonaceous materials having sufficiently high density to cause solid particles of a size providing reasonably high reactive surface area to fall in a lean solids stream countercurrent to a hydrogen-containing gas stream. The particle size may vary over quite wide ranges dependent upon the density of the solids. Suitable particle sizes are generally about -10 to about +200 U.S. Sieve. Suitable solid organic carbonaceous material is selected from the group consisting of oil shale, coal, peat and biomass.
Oil shales of the Eocene period generally found in the, western United States, particularly the northwestern area of Colorado and in the adjoining areas of Utah and Wyoming are suitable for use in this invention. These oil shales have an organic carbon to hydrogen weight ratio typically of less than 8/1 and usually of 7/1 to 8/1 and Modified Fischer Assays in the order of 25 gallons per ton or more. Oil shales have large quantities of "Black Shale" from deposits such as Devonian and Mississippian, generally found in the eastern portion of the United States are especially suitable for use in this invention. These oil shales have been found to have organic carbon to hydrogen weight ratios typically in the order of 10/1 up to about 13/1 and Modified Fischer Assays of less than 10 gallons of oil per ton and frequently as low as less than 5 gallons of oil per ton. The Modified Fischer Assays have been found to not represent the organic carbon actually present in the "eastern" type shale having the higher organic carbon to hydrogen weight ratios. Further, the inorganic carbon present in the "eastern" type oil shales is lower than that of the "western" type oil shales by a factor of greater than 10 and up to 30 to 40. The following table gives estimated compositions of both the organic and inorganic portions of a typical "eastern" and "western" oil shale.
TABLE I______________________________________ Source of Oil Shale Clark County, Ind. Colorado (Eastern) (Western) Weight Percent______________________________________OrganicCarbon 13.7 13.6Hydrogen 1.2 1.9Sulfur 0.3 0.3Nitrogen 0.4 0.5Oxygen 1.0 1.7Carbon/Hydrogen 11.4 7.2InorganicCarbon Dioxide 0.5 15.9Water 4.0 1.8Sulfur 4.4 0.2Ash 78.3 66.8Modified Fischer Assaygal/ton 10 30______________________________________
The excess of the totals over 100 percent is thought to be due to weight gain by oxidation of metals in the mineral component during ashing. It is readily observed from Table I that while the organic carbon content of the two oil shales is almost identical, the Modified Fischer Assay varies by a factor of 3. Oil shale having the properties set forth above as typical of "eastern" shale are particularly preferred for use in the process of this invention. Suitable coal for use in the process of this invention includes anthracite, bituminous and lignite. Peat suitable for use in this invention includes new peat and old peat.
Biomass materials suitable for use in this invention include heavy biomass materials such as organic solid sanitary and agricultural wastes and woods.
Suitable sizes for introduction of the solid organic carbonaceous material are about -10 to about +200 U.S. Sieve, about -55 to +200 U.S. Sieve being preferred. The size of the particles is dependent upon the density of the particle so as to provide desired free fall velocity against the countercurrent gas flow with a net velocity as set forth further herein. The solid organic carbonaceous materials useful as feed stock in this invention generally have a density of about 50 to about 200 pounds per cubic foot.
Referring to FIG. 1, the solid organic carbonaceous material may be pretreated in any desired fashion, such as reduction of moisture content, and provided to solids storage hopper 21 which, together with solids introduction conduit 22 and solids introduction feed means 23, make up solids feeding means 20. Any suitable solids feeding means as known to the art may be used. The feed solids are introduced to reactor 10 through vessel top bell 14 and pass over solids distribution baffles 24 to provide even distribution of the introduced solids across the area of the reactor. The solids pass downwardly by gravity and pass sequentially through solids preheat and pretreatment zone I, reaction zone II, heat addition zone III and hydrogen containing gas preheat zone IV. Heat addition zone III is provided between hydrogen-containing gas preheat zone IV and reaction zone II to provide the necessary addition of heat to maintain the reaction zone II at temperatures of about 800° to about 2000° F. The spent solids leave the reactor by spent solids discharge conduit 19 through reactor vessel bottom 16.
Hydrogen-containing gas passes upward through reactor 10 countercurrent to the downward passage of the solid organic carbonaceous material. Hydrogen-containing gas at or near ambient temperature conditions may be introduced to the lower portion of the reactor vessel through gas introduction conduit 31 controlled by valve V 1 and pass upwardly through gas distributor plate 32 and through hydrogen-containing gas preheat zone IV wherein the free falling solid particles transfer heat to the countercurrent flowing gas stream. The hydrogen-containing gas stream is further heated in heat addition zone III which may be considered, and is meant to be considered for the purpose of this disclosure and claims, as the lower portion of reaction zone II since further reaction may take place in zone III. Hot hydrogen-containing gas or hot non-reactive solids may be introduced through hot gas/solids conduit 44 controlled by valve V 4 . Any suitable means may be used to distribute the hot gas or hot solids generally uniformly across the reactor cross section. The amount of heat necessary to add in heat addition zone III is that amount sufficient to maintain the reaction zone II at desired temperatures of about 800° to about 2000° F. In preferred embodiments the temperatures in reaction zone II are maintained at about 800° to about 1200° F. for the production of liquids and at about 1400° to about 2000° F. for the production of gases. In one embodiment of this invention, the spent particles removed through discharge conduit 19, particularly when coal or peat is used as feed solids, may be combusted in a separate combustion process to heat the hydrogen-containing gas or non-reactive solids for introduction through conduit 44. It will be apparent that the amount of hydrogen-containing gas introduced through each of conduits 31 and 44 may be advantageously adjusted to provide the desired heat to reaction zone II. Thermal energy may also be provided to heat addition zone III by addition of combustible material through conduit 41 controlled by valve V 3 and mixing with oxygen-containing gas, such as air, introduced through conduit 42 controlled by valve V 2 in an amount sufficient for internal combustion within heat addition zone III to provide the desired temperatures in reaction zone II. Hydrogen may be combusted in heat addition zone II and such combustion may be controlled by control of the addition of oxygen.
The upwardly flowing hydrogen-containing gas stream entering reaction zone II is in an amount of about 10 to about 30 Standard Cubic Feet of hydrogen per pound of raw carbonaceous material in countercurrent flow thereto. It is preferred that the hydrogen-containing gas is introduced to the reaction zone in an amount of about 15 to about 25 Standard Cubic Feet of hydrogen per pound of the countercurrent flowing carbonaceous material. The solid carbonaceous material moves downwardly through the reaction zone at about 0.5 to about 2 feet per second, preferably about 1 to about 1.5 feet per second, while the hydrogen-containing gas moves counter-currently upward at a higher flow rate and about 1 to about 5 feet per second, preferably about 2 to about 4 feet per second, providing solids residence time in the reaction zone of about 20 to about 400 seconds. In a preferred embodiment, the solids residence time in the reaction zone is about 50 to about 200 seconds.
The upwardly flowing hydrogen-containing gas stream leaving reaction zone II passes upwardly through preheat and pretreatment zone I. In the solids preheat and pretreatment zone, thermal transfer between the hydrogen-containing gas and carbonaceous solids takes place cooling the gas and heating the solids. The hydrogen-rich gas pretreats the organic carbonaceous material by contact with it in such a manner as to improve obtention of desired substantially saturated liquid and gaseous hydrocarbon products in the reaction zone. The upwardly moving hydrogen-containing gas stream also carries the gaseous and vaporized liquid products from hydroconversion of the solid organic carbonaceous material in the reaction zone. The height of the solids preheat and pretreatment zone may be sufficient to allow substantial thermal exchange to take place which heats the free falling solids to near the desired temperature of the reaction zone and for pretreatment of solid organic carbonaceous material to render it more suitable for conversion of the organic carbonaceous component to liquid and gaseous hydrocarbon products in the reaction zone. This is practical due to the lean solids phase which will continue to flow uniformly even in the presence of condensation and refluxing of liquids on the solid particles. The lean phase solids virtually eliminates any problem of clogging due to condensation as encountered by the prior art with moving bed reaction systems. The gas stream passes upwardly from the solids preheat and pretreatment zone to a solids/gas separator means 33 located in upper zone 12 of the reactor. Solids/gas separator means may be conventionally used cyclones as are well known to the art or any other means for separation of entrained solids from the product gas. The solids/gas separator means is preferably located within the reactor vessel so that the solids may be returned directly to the solids preheat and pretreatment zone for recycle. Hydrogen containing gas with entrained product vapor and gases passes from the reaction system through product conduit 34.
The product stream comprises hydrocarbon liquids and low molecular weight paraffinic gases. The desired hydrocarbon liquids produced by the process of this invention are especially suited for further processing, such as production of naphtha, gasoline, kerosene, jet fuel, diesel oil and light fuel oils, and other low boiling distillate oils as well as for conversion to high methane content pipeline quality gas. The desired low molecular weight paraffinic gas products include molecules of 4 and less carbon atoms, namely, methane, ethane, propane butane and isobutane. When liquid product is desired, the process may be adjusted as described above so that less than about 20 percent of the organic carbonaceous material is converted to the gas form.
The terminology "hydrogen-containing gas" throughout this description and claims, means gases having sufficient hydrogen partial pressure to effect high organic carbon hydroconversion from the organic carbonaceous feed material. Such hydrogen-containing gases may be obtained by a number of processes well known in the chemical process industry. It is preferred to use hydrogen containing gas having a partial pressure of hydrogen greater than about 100 psia. The upper operating pressures are limited only by equipment and economic considerations. Higher hydrogen partial pressures allow higher reaction rates and thus smaller reactors. Total operating pressures throughout the process system are usually substantially the same. Normally, the process of this invention may be carried out at total pressures of about 40 to 1500 psia, preferably about 500 to 1000 psia.
A particularly well suited reactor for carrying out the process of this invention is shown in FIG. 1. Vertical reactor vessel 10 has substantially vertical walls 11 through its central portion, the walls extending outwardly shown as expanded vessel walls 12 forming an expanded volume in the upper portion of the reactor. A bell-shaped reactor top 14 has depending walls 17 substantially in line with the reactor vessel walls 11 and extend downwardly in the expanded volume having their bottom ends spaced from reactor walls 11 forming an annular solids/gas separation zone between depending walls 17 and expanded vessel walls 12. Depending walls 17 define a solids distribution zone having solids distribution baffles 24 capable of distributing the feed solids substantially evenly across the area of the reactor vessel. Solids feed means 20 introduces feed solids into the upper portion of the solids distribution zone and may be any suitable feed means capable of supplying solids to the pressurized vessel. Solids/gas separator means 33 are located within the annular solids/gas separation zone and may feed the solids directly back to the straight wall portion of the reactor vessel. Product conduit 34 is in communication with the gas exit of the solids/gas separator means 33 and conveys the products from the reactor. In the lower portion of the reactor, gas distribution means 32 is capable of distributing passing gas across the cross section of the reactor vessel. Gas introduction and supply means 31 allows the entry of hydrogen-containing gas to the portion of the reactor vessel below gas distribution means 32. While with some organic carbonaceous feed materials the ash will be carried out with the product stream, spent solids discharge conduit 19 with valve 5 is provided in case of spent solids which are too large to be removed with the product gas. The process of this invention requires addition of heat. A particularly suitable means for introduction of heat to a heat addition zone in the lower portion the reaction zone is shown in FIG. 1 wherein upwardly extending expanded vessel wall 13 and downwardly extending vessel wall 15 form an annular volume around the heat addition zone to provide for introduction of hot particulates, hot gases or combustible materials for internal combustion within the heat addition zone.
FIG. 2 shows another preferred embodiment for solids introduction and distribution substantially evenly across the area of the reactor vessel. Fluidized bed support 25 extends across the lower portion of depending walls 17 and a plurality of overflow tubes 27 extend from the height of the fluidized bed 26 downwardly through support plate 25 distributing solids substantially evenly across the area defined by reactor vessel walls 11. It is preferred that the lower ends of overflow tubes 27 have baffles 29 to prevent entry of product vapor.
The apparatus of this invention may be constructed of materials apparent to those skilled in the art upon reading this disclosure and are principally dependent upon desired operating temperatures and pressures as well as overall reactor size.
While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention. | A process and apparatus for production of liquid and gaseous hydrocarbon products from solid organic carbonaceous materials by reacting free falling solids with a countercurrent hydrogen-containing gas stream. The process is conducted with a lean solids phase which provides good process control and uniform flow of solids even in the presence of condensation and refluxing of liquids on the solid particles. Oil shales of the Eocene period having Modified Fischer Assays of less than about 9 gallons of oil per ton and representing less than half the organic carbon present in the oil shale are particularly well suited for the process of this invention. A reactor particularly suited for conducting reactions between free falling solids and countercurrent flowing gas streams is disclosed together with preferred methods for introduction of solid feeds to the top of the reactor including distribution baffles and fluidized bed feed distribution systems. | 2 |
This application is a continuation of U.S. application. Ser. No. 11/599,443 filed Nov. 15, 2006, which is a continuation of U.S. application Ser. No. 10/323,656 filed. Dec. 20, 2002 (now U.S. Pat. No. 7,205,107), which claims priority from U.S. Provisional Application Ser. No. 60/341,832 filed Dec. 21, 2011. The entirety of of these applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to diagnostic method and apparatus based upon a functional polymorphism in the promoter of a gene encoding macrophage migration inhibitory factor (MIF). More specifically, this invention relates to a method for diagnosis of predisposition to certain disease states, by screening for the presence of this promoter polymorphism. The invention also relates to apparatus for screening for the polymorphism, MIF genes containing the polymorphism and to a probe therefor.
2. Background of the Technology
A number of experimental studies have led to the concept that macrophage migration inhibitory factor (MIF) functions as a physiological counter-regulator of glucocorticoid action within the immune system. In this role, MIF's position within the cytokine cascade is to act in concert with endogenous glucocorticoids to control the set point and the magnitude of the inflammatory response (1). MIF also has several direct, pro-inflammatory roles in inflammatory diseases such as rheumatoid arthritis (2), sepsis (3, 4), acute respiratory distress syndrome (5), and glomerulonephritis (6).
MIF was originally described over 30 years ago as a T-lymphocyte-derived factor that inhibited the migration of peritoneal macrophages (7), but it is now known that several other cell types, including macrophages themselves, are important sources of MIF (8), MIF levels are elevated in the serum and synovial fluid of patients with rheumatoid arthritis (2, 9), and within the synovial joint MIF immunostaining can be localized to the synovial lining CD14+ macrophages and fibroblast-like synoviocytes (2). Upon release MIF is directly pro-inflammatory by activating or promoting cytokine expression (TNFα (8, 10), IL-1β, IL-2 (11), IL-6 (8,12), IL-8 (13) and IFNγ (11, 14)), nitric oxide release (15), matrix metalloproteinase (MMP) expression (16, 17), and induction of the cyclooxygenase-2 (Cox-2) pathway (18). MIF's capacity to induce to sustained activation of the p44/p42 (ERK-1/2) MAP kinase pathway (18) and to inhibit p53-dependent apoptosis (19, 20) also suggest that this mediator may play a key role in initiation of rheumatoid pannus.
U.S. Pat. No. 6,030,615 to Bucala. et al. discloses a combination method for treating diseases caused by cytokine-mediated toxicity, comprising administering an effective amount of (a) an MIF inhibitor, such as an antibody that binds to an MIF polypeptide, wherein the MIF polypeptide has a molecular weight of about 12.5 kDa in combination with (b) anti-TNFα, anti-IL1, anti-IFN-γ, IL-1RA, a steroid, a glucocorticoid, or IL-10.
The concept that polymorphisms in immune response genes contribute to the pathogenesis of certain human autoimmune/inflammatory diseases has received increasing interest over the last several years. At present, very few gene polymorphisms have been shown to be functionally significant and to be of prognostic value in specific disease states. Previously defined examples include polymorphisms in TNFα and IL-1ra that have been shown to have certain prognostic significance in malaria and ischaemic heart disease respectively (24,25). Similarly, a number, of polymorphisms in TNFα and IL-β have been reported to be associated with rheumatoid arthritis severity (26-28).
SUMMARY OF THE INVENTION
The present invention is based in part upon identification of a novel polymorphism in the human Mif gene that consists of a tetra-nucleotide CATT repeat located at position −817 of the Mif promoter. As disclosed herein, this promoter polymorphism is functionally significant in vitro, and analysis of a cohort of patients with rheumatoid arthritis indicates that this CATT repeat is associated with disease severity.
One object of this invention, therefore, is to provide a method of diagnosis comprising determining the genotype of a human Mif promoter.
Another object of this invention is to provide diagnostic means, comprising a means for determining the genotype of a human Mif promoter.
Accordingly, the invention relates to a method of diagnosis of severity of a non-infectious inflammatory disease or of a predisposition to severity of a non-infectious inflammatory disease comprising detecting a polymorphism in a human Mif promoter that correlates with an increase or decrease in MIF polypeptide expression. In this method the non-infectious inflammatory disease is, for instance, autoimmunity, graft versus host disease, or preferably rheumatoid arthritis, and preferably detection of the polymorphism is indicative of the severity of the disease or predisposition to severity of the disease. Preferably, this polymorphism in a human Mif promoter that correlates with an increase or decrease in MIF polypeptide expression is a CATT-tretranucleotide repeat polymorphism at position −817 of the human Mif gene, selected from the group consisting of 5, 6, 7 and 8 repeat units, where presence of the 5 repeat unit indicates occurrence of or predisposition to low disease severity.
The diagnostic method of of the invention preferably comprises a step of amplifying the Mif promoter using a PCR technique. For this purpose, the invention provides a PCR primer set selected to amplify a region of a human Mif promoter. For instance, the PCR primer set may be selected from the group consisting of: (i) MIF-F (−1024) and MIF-R (−421); (ii) MIF-F (−441) and MIF-R (+4); (iii) MIF-F (−13) and MIF-R (+395); and (iv) MIF-F (+379) and MIF-R (+1043), as shown in Table 1, infra. The invention also relates to a method of using a primer set of the invention to detect a polymorphism in a human Mif promoter region, and an article of manufacture (such as a diagnostic kit) comprising a PCR primer set of the invention.
The invention further relates to nucleic acid molecule comprising a human Mif promoter sequence in which the CATT-tetranucleotide at position −817 is repeated 5, 6, 7 or 8 times. Preferably, the nucleic acid molecule is an isolated DNA molecule, particularly an isolated genomic DNA fragment that has been amplified from a DNA sample of a human subject. In preferred embodiments, the isolated nucleic acid molecule of the invention comprises a portion of a human Mif promoter that comprises a CATT-tretranucleotide repeat polymorphism at position −817 of the human Mif gene.
Another aspect of the present invention relates to a method of inflammatory disease therapy comprising screening an individual for severity of a non-infectious inflammatory disease or of a predisposition to severity of a non-infectious inflammatory disease. This method comprises: detecting in a human subject a polymorphism in a human Mif promoter that correlates with an increase or decrease in MIF polypeptide expression, where detection of the polymorphism is indicative of the severity of the disease or predisposition to severity of the disease. This method of inflammatory disease therapy further comprises treating the human subject to prevent or reduce the severity of the inflammatory disease or to delay the onset of the inflammatory disease. For instance, the therapy may comprise treating the human subject by administering an effective amount of at least one agent selected from the group consisting of an MIF inhibitor, an anti-TNFα antibody, an anti-IL1 antibody, and anti-IFN-γ antibody, IL-1RA, a steroid, a glucocorticoid, and IL-10.
In a preferred embodiment of the invention method of inflammatory disease therapy the inflammatory disease is rheumatoid arthritis and the polymorphism in a human Mif promoter is a CATT-tretranucleotide repeat polymorphism at position −817 of the human Mif gene.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a schematic representation of the human Mif promoter region. Putative transcription factor binding sites and areas of interest are boxed. The polymorphic CATT repeat region (−817 to −797/−785) is indicated by a lack of shading.
FIG. 2 shows the basal transcriptional activity of human Mif promoter polymorphic variants in Cos -7 cells. MIF promoter activity was determined by dual luciferase assays with results expressed as relative light units (RLU). Cos -7 cells were transiently co-transfected with 800 ng of test DNA vector: pGL3-basic (negative control), pMIF-5, pMIF-6, pMIF-7, or pMIF-8 (5, 6, 7, or 8-CATT repeat polymorphism specific MIF promoter-luciferase constructs) and 200 ng of control pRLTK vector. After 48 hours, the cells were lysed and luciferase activity was determined in relation to renilla activity using a dual luciferase kit (Promega) and a TD 20/20 luminometer. The data represent the mean of four individual experiments each carried out in duplicate±STDEV. * indicates P<0,03 vs. activity of pMIF-5 construct.
FIG. 3 shows the effect of CATT-repeat polymorphic variation on Mif promoter responses to serum and forskolin stimulation in Cos -7 cells. MIF promoter activity was determined by dual luciferase assays with results expressed as relative light units (RLU). Cos -7 cells were transiently co-transfected with 800 ng of test DNA vector: pGL3-basic (negative control), pMIF-5, pMIF-6, pMIF-7, or pMIF-8 (5, 6, 7, or 8-CATT repeat polymorphism specific MIF promoter-luciferase constructs) and 200 ng of control pRLTK vector. After 24 hours of transfection, the cells were washed in PBS and then cultured in serum free media overnight. The cells were then either left unstimulated (serum starved) or treated with 2% fetal calf serum (FCS) or 1 μM forskolin (“1 uM FSK”). After a further twelve hour incubation luciferase activity was determined as in FIG. 2 . The data represent the mean of four individual experiments each carried out in duplicate STDEV. * indicates P<0.03 vs. activity of pMIF-5 construct.
FIGS. 4A and 4B depict the nucleic acid sequence for human MIF (SEQ ID NO: 12). The nucleotide position designated as -817 in the figure is position 259 of SEQ ID NO: 12.
DETAILED DESCRIPTION OF THE INVENTION
The novel Mif gene polymorphism identified herein is associated with reduced MIF promoter activity, and the presence of this genotype in the homozygous state appears to be associated with a reduced risk of severe rheumatoid arthritis.
MIF has been shown to promote TNFα secretion and to enhance IFNγ induced nitric oxide secretion from macrophages (8). In addition, MIF is an important autocrine regulator of macrophage (8), T-cell (11) and fibroblast activation (18). These data have led to numerous investigations of the potential role for MIF in chronic inflammatory conditions such as rheumatoid arthritis.
MIF protein levels circulate in higher levels in serum of rheumatoid arthritis patients and cellular MIF expression is enhanced within the synovium (2, 9). Cultured synovial fibroblasts obtained from patients with rheumatoid arthritis secrete significant quantities of MIF spontaneously in culture, and secretion increases further following pro-inflammatory stimulation (2). MIF stimulation of rheumatoid synovial fibroblasts results in increased expression of matrix metalloproteinases (16), as well as the induction of phospholipase A 2 (PLA 2 ) and COX-2 expression (29). Immunoneutralization of MIF activity in synoviocyte cultures also has been shown to inhibit IL-Iβ induced expression of COX-2 and PLA 2 mRNA (29). The administration of a neutralizing anti-MIF antibody also delays the onset and decreases the severity of type-11 collagen induced arthritis in mice (30) and profoundly inhibits the development of adjuvant-induced arthritis in rats (31). Thus, there is considerable evidence implicating MIF in the pathogenesis of inflammatory arthritis.
Disclosed herein is a significant association between patients that are homozygous for the low expressing, 5-CATT allele and less aggressive rheumatoid disease. Only 1/79 (1.2%) patients with severe rheumatoid arthritis inherited this genotype, compared with 101105 (9.5%) of patients with milder, non-progressive disease. This suggests that a genetic predisposition to low expression of MIF protects against persistent inflammation and/or joint destruction. It is unknown at present which transcription factors may be involved in modulating the transcriptional effects of the polymorphic region, but the 5-CATT allele shows reduced responses in vitro to both serum and forskolin stimulation as well as reduced basal activity. A CATT repeated element also exists in the promoter of human granulocyte-macrophage colony-stimulating factor (GM-CSF), and is required for promoter activity (32, 33). It has been shown that the nuclear factor YY1 34 , and more recently the factors AF-1 and SP-1, can form complexes with this region of the GM-CSF promoter (35). Whether any of these same factors also influence the activity of the MIF CATT repeat remains to be determined.
The CATT-repeat region within the Mif gene contains several putative Pit-1 transcription factor binding sites. Pit-1 is a pituitary-specific transcription factor that is critical for the expression of pituitary hormones such as prolactin and growth hormone (36). The anterior pituitary gland is an important source of MIF in rodents (3) and secretes MIF in response to physiological or infective stress (37). Corticotrophin-releasing factor (CRF) also has been shown to be a potent inducer of MIF expression in cultured pituitary cells. A recent functional analysis of the murine MIF gene-promoter using rat pituitary cells and the pituitary cell line AtT-20 demonstrated that CRF-induced gene expression is dependent upon a cAMP responsive element binding protein (38). Interestingly, reports of linkage of the CRF locus to rheumatoid arthritis have recently appeared in the literature, and there is some evidence that the hypothalamic pituitary-adrenal (HPA) axis may play a role in the pathogenesis of rheumatoid arthritis in certain patients. Patients with active rheumatoid arthritis have been shown to have abnormally low diurnal cortisol levels in the face of normal pituitary and adrenal function, suggesting a defect at the hypothalamic level (40). Given MIF's capacity to counter-regulate glucocorticoid action within the immune system (reviewed by Bucala (1)), the expression of MIF by the anterior pituitary gland may be important to the development of inflammatory diseases such as rheumatoid arthritis.
Since the initiation of these studies, a −173*G/C single nucleotide polymorphism (SNP) in the Mif gene promoter has been reported by Donn, et al. (41) and was shown to be associated with systemic-onset juvenile idiopathic arthritis (systemic-onset JIA). The possession of at least one 173*C allele was seen in 36.8% of patients with systemic-onset JIA compared to 20.3% of the normal population (41). However, there is no information concerning the effect of this SNP on gene expression. A preliminary analysis by the present inventors indicates that the 173*C allele cannot explain the present association data or results of promoter assays; indeed, there is no evidence of positive linkage disequilibrium between the 173*C allele and the 5-CAAT allele (data not shown).
TNFα is considered to be a critical effector cytokine in rheumatoid arthritis, and anti-TNFα therapy has emerged to have high efficacy in the treatment of this diseaese (42). Of note, there is a close relationship between MIF and TNFα. MIF appears to act as an important upstream regulator of TNFα expression. MIF promotes secretion of TNFα from macrophages and overrides the ability of glucocorticoids to suppress macrophage TNFα production (43). Immunoneutralization of MIF also reduces circulating levels of TNFα (3). In a clinical setting, the analysis of MIF polymorphisms provides a prognosticator of disease severity, particularly in inflammatory diseases and more particularly in rheumatoid disease, and can assist in the selection of interventional therapy. The data herein also reaffirm the potential importance of MIF as a therapeutic target in rheumatoid arthritis and possibly other inflammatory diseases.
EXPERIMENTAL
Materials and Methods
Patients: DNA samples were obtained from the Wichita Rheumatic Disease Data Bank and were representative of Caucasian patients followed in a rheumatology practice since 1974. The rheumatoid arthritis patients were divided into 2 groups using the following criteria: A) Severe (n=79); mean age at onset 55 years, mean disease duration of 13 years, mean Larsen score rate of 4.0, mean RF titer of 339.24 and a mean HAQ score of 1.36. B) Mild (n=105); mean age at onset 45 years, mean disease duration of 15 years, mean Larsen score of 1.0, mean RF titer of 362.84 and a mean HAQ score of 0.93, Healthy Caucasian volunteers provided genomic DNA that was used as the normal control group (n=159),
DNA extraction: DNA was extracted from whole blood using the G Nome kit (Bio 101 Inc., CA, USA) and from the buccal brushes using the Pure Gene Kit® (Gentra Systems Inc., MN, USA).
Mif gene Sequencing and Polymorphism analysis: The Mif gene (GenBank Accession number: L19686, hereby incorporated in its entirety herein by reference) is located on chromosome 22qll.2 (44). The gene is 2167 bp long and has 3 exons separated by 2 introns of 189 bp and 95 bp. Four sets of primers were used to span the entire gene (Table 1, below).
TABLE 1 Primer sequences and conditions for PCR of the Mif Gene Annealing PCR PCR Primer Primer Sequences Temp Special Product Set Locations (5′-3′) (° C.) Conditions Size SET MIF-F (−1074) TGCAGGAACCAATACCCATAGG 58.1 654 bp 1 (SEQ. ID NO: 1) MIF-R (−421) TGCGTGAGCTTGTGTGTTTGAG (SEQ. ID NO: 2) SET MIF-F (−441) TCAAACACACAAGCTCACGCA 60.8 10% DMSO 445 bp 2 (SEQ. ID NO: 3) MIF-R (+4) TGGTCCCGCCTTTTGTG (SEQ. ID NO: 4) SET MIF-F (−13) CACAAAAGGCGGGACCACA 62.3 25% 7-Deaza 408 bp 3 (SEQ. ID NO: 5) GTP in 1.25 MIF-R (+395) ACTGCGAGGAAAGGGCG mM dNTP (SEQ. ID NO: 6) SET MIF-F (+379) CGCCCTTTCCTCGCAGT 10% DMSO 665 bp 4 (SEQ. ID NO: 7) MIF-R (+1043) TAGAATGGAAAGACACTGGG (SEQ. ID NO: 8)
The PCR reaction consisted of 1× PCR buffer II (Perkin Elmer, CA, USA), 20 ng DNA, 1.5 mM MgCl 2 , 20 pmoles each of forward and reverse primers and 0.5 units of Amplitaq Gold® polymerase (Perkin Elmer—Applied Biosystems, CA, USA). The dNTP were used at a concentration of 0.2 mM except for set 3, where the 0.2 mM dNTP had 0.05 mM of 7-Deaza GTP in a 20 μl PCR reaction, The PCR conditions were as follows: 95° C./12 min, followed by 40 cycles of 95° C./30 sec, annealing temp (Table 1)/30 sec, 72° C./60 sec and 72° C./10 min. The PCR products were resolved using a 1% agarose gel stained with ethidium bromide.
The PCR products from 6 normal controls and 6 rheumatoid arthritis patients were sequenced using the Big Dye Terminator® cycle sequencing ready reaction kit (Perkin Elmer—Applied Biosystems). The sequences from all four primer sets were compiled to represent the entire Mif gene and were compared to analyze differences between the rheumatoid arthritis group and the normal controls.
Rapid screening for CATT repeat polymorphism: The forward primer from Set 1 (SEQ. ID. NO: 1) was used with the reverse primer MIF-R −728 (5′-AATGGTAAACTCGGGGAC-3′; SEQ. ID NO: 9). The reverse primer was fluorescently labeled with TET to allow detection of the PCR products using capillary electrophoresis (45).
The PCR conditions were 1× PCR Buffer II, 1.5 mM MgCl 2 , 0.2 mM dNTP, 0.75 pmoles of each primer, 1 ng DNA, 0.05 μl AmpliTaq Gold polymerase in a 10 μl PCR reaction. The PCR cycling conditions used were the same as described above except for annealing conditions of 53.8° C./30 sec. 1 μl of diluted PCR product was added to 12 μl of deionized formamide containing 0.5 μl GS-500 TAMRA size standard (Perkin Elmer—Applied Biosystems). Samples were denatured before being resolved using an ABI 310 Genetic Analyzer (Perkin Elmer—Applied Biosystems). DNA samples from homozygous individuals that previously had been fully sequenced were used as controls for the repeat sizes obtained by capillary electrophoresis.
MIF Promoter cloning and Reporter Assays: Genomic DNA obtained from the primary screening that contained the 5, 6, 7, or 8-CATT tetranucleotide repeat polymorphism was used as a PCR template for initial cloning into the pCR2.1-TOPO vector (Invitrogen, CA, USA). The following primers were used to generate a 1173-1189 bp PCR product representing 1071-1087 bp of the upstream flanking region of the MIF coding sequence plus the first 102 bp of exon I (see FIG. 1 ):
Forward primer:
(SEQ. ID NO: 10)
5′-CTCGAGCTGCAGGAACCAATACCCAT-3′;
Reverse primer:
(SEQ. ID NO: 11)
5′-AAGCTTGGCATGATGGCAGAAGGACC-3′.
After complete sequencing, the promoter region was excised from the pCR2.1 vector and cloned into the XhoI/HindIII sites of the pGL3-Basic luciferase vector (Promega, WI, USA). This vector contains the CDNA encoding a modified version of firefly luciferase in the absence of eukaryotic enhancer or promoter elements. Luciferase constructs directly regulated by the MIF promoter, containing the 5, 6, 7, or 8-CATT polymorphism, were generated. Transient transfections were carried out using 3 μl Fugene 6 (Roche, NJ, USA) and 1 μg of DNA per well of a six well plate as per manufacturers directions. Cell lines used included Cos -7 (monkey kidney fibroblast), A549 (human lung epithelium) and CCD-19LU (primary human lung fibroblast). Data were normalized in relation to an internal control of Renilla luciferase that was regulated by the Herpes simplex virus thymidine kinase promoter (PRL-TK vector—Promega, WI, USA). Subsequently, each transfection consisted of 800 ng of test DNA (MIF-promoter regulated Luciferase gene) combined with 200 ng of PRL-TK control vector DNA. Luciferase assays were measured using a TD-20/20 luminometer (Turner Designs, CA, USA) and the Dual Luciferase Reporter System (Promega, WI, USA). Basal promoter activity was determined by measuring luciferase activity 36 hours after transfection. In some cases, cells were stimulated for the last 20 hours of culture prior to measurement of promoter activity.
Genotype and statistical analysis: The data were analyzed using Genotype® 2.1 software (Perkin Elmer—Applied Biosystems, CA, USA). The relationship between the genotypes and disease status (normal, mild or severe) was examined using the chi-square test and Fishers exact test. Gene reporter assays were repeated 3 to 10 times in duplicate. Data are presented as mean±STDEV and compared by non-parametric Mann-Whitney U tests. Significance was defined as P<0.05.
Results
Identification of a Microsatellite Repeat in the Mif Promoter. Genomic DNA from six normal volunteers and six rheumatoid patients was utilized for full sequencing of the Mif gene. Due to the high GC content of this gene, the analysis was carried out in four sections. Alignment of all twelve sequences identified a tetra-nucleotide CATT repeat polymorphism in the upstream promoter region at position −817 ( FIG. 1 ). Individuals having 5, 6, 7 or 8-CATT repeat alleles in their sequences were found. Individuals were either heterozygous or homozygous for these alleles, although no 7-CATT homozygotes were found in the normal population and no 8-CATT homozygotes were found in either population studied.
For rapid screening of the promoter polymorphism, a fluorescently labeled reverse primer that was proximal to the tetranucleotide repeat units was designed in order to amplify a smaller PCR fragment (340-352 bp). This fragment then was analyzed using capillary electrophoresis on an ABI 310 Genetic analyzer. The DNA of individuals previously sequenced was used as a template to generate control DNA fragments in order to correlate the fragment size observed on the ABI 310 analyzer with the number of CATT repeats in the test samples. Accordingly, the 4 PCR product sizes were 340, 344, 348, and 352 bp in length, and these corresponded to five, six, seven, and eight-CATT repeats, respectively. The genotypes observed were: 5,5; 5,6; 5,7; 6,6; 6,7; 7,7; 5,8; and 6,8. The 8,8 genotype was not seen in either the normal (rr159) or patient (n=184) populations; and the 7,7 genotype was not seen in the normal population, but was observed in one patient within the rheumatoid arthritis group.
Distribution of Mif Alleles in Normal Controls and Rheumatoid Arthritis Patients. The distribution of the different Mif alleles in normal controls, mild rheumatoid arthritis and severe rheumatoid arthritis patients are shown in Table 2, below.
TABLE 2
Distribution of MIF genotypes and the frequency of 5-CATT allele
in normal and rheumatoid arthritis (RA) popluations.
Frequency of
5-CATT allele
5,5 or
MIF-Genotype
5,X
X,X
Population
5,5
6,6
7,7
5,6
5,7
6,7
5,8
6,8
alleles
alleles
Normal
8
53
0
61
10
25
1
1
80
79
(u-159)
(5.03%)
(33.33%)
(38.36%)
(6.3%)
(15.72%)
(0.63%)
(0.63%)
(50.31%)
(49.69%)
Wichita
10
49
1
23
8
14
0
0
41
64
Mild RA
(9.52%)
(46.67%)
(0.95%)
(21.91%)
(7.62%)
(13.33%)
(39.05%)
(60.95%)
(u-105)
Wichita
1
40
0
20
4
13
0
1
25
54
Severe RA
(1.27%)
(50.63%)
(25.31%)
(5.06%)
(16.46%)
(1.27%)
(31.65%)
(68.35%)
u = 79
The number of individuals carrying at least one 5-CATT allele decreases from 50.31% in the normal population to 31.65% in the severe rheumatoid arthritis population (Table 2). The difference between the severe rheumatoid arthritis patients and controls is statistically significant (p<0.02). The cases and controls analyzed in this study were not closely matched for geographic and ethnic origin, hence the data must be interpreted with some caution. A comparison of specific genotypes between the mild and severe rheumatoid arthritis populations was therefore carried out, as shown in Table 2. The 5,5 genotype is observed in 9.5% of the patients with mild rheumatoid arthritis, but is significantly decreased to 1.3% in the patients with severe disease (p=0.0252 by Fisher's exact test). These data indicate that a homozygous 5-CATT allele is protective for the development of severe disease.
Effect of the CATT repeat polymorphism on MIF promoter activity. To investigate whether the CATT repeat polymorphism was associated with functional regulation of MIF expression, a gene reporter assay was developed and studied under defined conditions in vitro. Gene reporter assays have been widely employed to study transcriptional regulation, or as readouts to monitor transcription factor (21,22),
Transfection of the Mif promoter-regulated luciferase constructs into Cos-7 cells, A549 cells, and CCD-19Lu cells was associated with strong basal promoter activity, as indicated by high luciferase production, when compared to control vector (pGL3-Basic) ( FIG. 2 and data not shown). Promoter activity was increased by forskolin (an inducer of CAMP synthesis 23) and serum stimulation ( FIG. 3 ), as well as phorbol ester stimulation (data not shown). In general, basal promoter activity was high in each of the cell lines tested when compared to negative (empty pGL3 vector) and positive (pRL-TK) controls, and these data appeared to correlate with the high level of endogenous MIF protein expression that was observed in these cell lines (data not shown). Of note, in each of the cell lines tested, the 5-CATT repeat MIF promoter construct showed significantly lower transcriptional activity when compared to the 6, 7, or 8-CATT repeat promoter constructs.
Reference List
The following documents are cited parenthetically by number in the specification above.
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All patents, patent applications and publications mentioned hereinabove are hereby incorporated by reference in their entirety.
While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention and appended claims. | Describe herein is a novel CATT-tetranucleotide repeat polymorphism at position −817 of the human Mif that functionally affects the activity of the Macrophage Inhibitory Factor (MIF) promoter in gene reporter assays. Four genotypes are described which comprise 5, 6, 7, or 8-CATT repeat units. Of these, the 5-CATT allele has the lowest level of basal and stimulated MIF promoter activity in vitro. The presence of the low expressing, 5-CATT repeat allele correlated with low disease severity in a cohort of rheumatoid arthritis patients. Methods, compositions and apparatus for detecting this CATT-tetranucleotide repeat polymorphism at position −817 of the human Mif gene, and for using same for assessing predisposition to severe inflammatory disease, are also disclosed. | 2 |
The present invention relates in general to structural foundation repair and in particular to a method and apparatus for drilling a supporting pier to lift and support a structure from a foundation side.
BACKGROUND
Many types of structures, such as residential homes, commercial buildings and industrial equipment, are erected on foundations that are in turn supported by unstable soil rather than a load bearing formation such as rock. These foundations are typically concrete slabs and may include a footing that is wider than the foundation to spread the load of the foundation and carried structure. Ultimately the structural integrity and the level of the foundation and the carried structure are dependent on the stability of the underlying soil. Over time the stability of the underlying soil may change. These changes may include shifting of the soil and or subsidence of the underlying soil or portions of the supporting soil. Shifting of the soil may be caused by various geological and environmental conditions and/or the load carried by the structure. The changes in the supporting soil often result in damage to the structural integrity of the foundation and the carried structure and/or producing a non-level foundation. Left uncorrected the settling of the soil and lack of stability of the foundation may result in loss of part or all of the value of the foundation and carried structure. Due to the frequency of damage to foundations from soil settlement many systems have been attempted to stabilize the foundation and to correct positioning of the foundation.
The majority of methods and systems utilized to correct foundation damage is costly and often only provides a temporary solution or an incomplete solution. Many of the prior art foundation repair systems consist of driving piers into the underlying soil until refusal of insertion is attained. It is desired that the piers be driven until bedrock is reached or until the frictional resistance to driving of the pier corresponds to the compression weight of the supported structure. Once the piers are positioned in the ground hydraulic jacks are utilized to lift the foundation relative to the ground level. When the desired raised level is achieved the pier is connected to the foundation to secure the foundation in place, at least for the short term. Another constant aspect of the prior art foundation lifting systems is the utilization of brackets, or supports, that connect to the underneath side of the foundation. This positioning of the brackets on the underside of the foundation requires that a portion of the underlying soil be excavated from beneath the foundation.
In various situations it is necessary to raise and support the foundation within the perimeter of the foundation. Prior art methods and systems require cutting away a portion of the foundation and then excavating the soil from beneath the intact foundation to connect the lifting and supporting apparatus to the underside of the foundation. This additional excavation of the soil from beneath the intact foundation increases the time and cost of the project and increase the risk to workers as they position connections beneath the foundation.
Driving of piers, pilings or piles into the soil is a source of some of the most severe drawbacks of the prior art systems. Piers are typically driven into the ground utilizing a hydraulic mechanism until refusal and/or until the frictional resistance of the pier corresponds to the compression load of the foundation and structure. Very often bedrock is not encountered and the driven pier is supported by an unstable formation. It is also the case that the driven piers may pass through formations such as shale or other tight soils increasing the frictional force of driving the pier thereby providing misleading information as to contact with a suitable supporting formation. These geological formations may only provide temporary lifting and support of the foundation. Over time, changes in soil moisture content and other geological conditions may result in reduced or increased skin friction at the soil pier interface in these formations resulting in loss of stability from this formations.
Another problem with pier driving systems is maintaining a vertical alignment of the driven pier when the soil contains small boulders or other hard obstructions. As the pile is driven it may encounter several different soil formations and other material that will cause the pier to deviate from vertical. Piers may be twisted and even turned so that a portion extends horizontal relative to the intended pier path. These occurrences make it appear as though the pier has encountered a load bearing strata such as bedrock. The result being an expensive temporary solution or even another source of foundation problems.
Further, pier driven systems are limited on the diameter of pipe that may be used as a pier, thus decreasing the load strength of each pier. In addition, pier driven systems do not facilitate testing of the depth to the bedrock before driving the pier.
It is thus a desire to provide a method and apparatus for lifting and stabilizing a foundation that addresses some of these and other shortcomings of the prior art. It is a desire to provide a method and apparatus for lifting and stabilizing a foundation wherein a pier is placed in a substantially vertical position from a foundation to an underlying rock formation. It is a further desire to provide method and apparatus for lifting and stabilizing a foundation wherein a foundation may be lifted and stabilized from a periphery of the foundation. It is a still further desire to provide method and apparatus for lifting and stabilizing a foundation wherein lifting and supporting of a foundation may be from the edge of the foundation. It is a still further desire to provide a method and apparatus for lifting and stabilizing a foundation that does not require maintenance. It is a still further desire to provide a method and apparatus for lifting and stabilizing a foundation that does not require special soils be placed around the foundation to maintain its future performance. It is a still further desire to provide a method and apparatus for lifting and stabilizing a foundation that does not require drainage corrections around the foundation for performance.
SUMMARY OF THE INVENTION
In view of the foregoing and other considerations, the present invention relates to foundation repair wherein a foundation may be raised and stabilized from a stable geological formation, such as bedrock or other hard rock, without driving a pier.
It is a benefit of the present invention to provide a method and apparatus for lifting and stabilizing a foundation by drilling a hole from the foundation to a stable geological formation for placement of a pier.
It is a further benefit of the present invention to provide a method and apparatus for lifting and stabilizing a foundation from the periphery of the foundation.
It is a still further benefit of the present invention to provide a method and apparatus for lifting and stabilizing a foundation that does not require maintenance for continual support of a structure.
Accordingly, a method and apparatus for lifting and stabilizing a foundation is provided. The foundation and lifting system includes a pier having a top end and a bottom end, the pier being disposed in shaft drilled proximate the foundation to a desired underground formation suitable for supporting the foundation; a slab bracket connected to a side of the foundation and not supporting the foundation from the underside thereof, a jacking bracket attached to the top end of the pier and positioned below the slab bracket; and means for supporting the foundation positional between the jacking bracket and the slab bracket. This to rock support system prevents settling without regard to the supporting soil.
For brevity and clarity the present invention is described in relation to common residential and commercial structures supported on concrete slabs, and bedrock. However, it should be realized that the present invention may be applied to any structure or foundation, and any hard geological formation sufficient to support the structure may be utilized. For example, the present system and method may be utilized for construction and support of a deck or other structure proximate a hillside house adjacent a creek. A carbide bit may be used to drill a shaft into a rock formation at the bottom of the creek and the jacking bracket may be bolted to the wood beam to support the structure. Another example is utilization of the present invention is in the support of a retaining wall on a hillside experiencing slope failure. Utilizing the present invention the retaining wall is prevented from settling or sliding down the hill.
It is desirable to drill the shaft to an underground rock formation, such as bedrock, sufficient for stable and long term support of the foundation. Using a dirt drill bit a shaft is drilled to and into a geological formation until the formation does not allow a shaft to be created. Utilizing the dirt bit until drilling operations are prevented from making hole by the formation assures the acquisition of a formation suitable for support of the structure.
The pier, having a top end and a bottom end, is placed in the drilled shaft. It may be desired to clean any silt, cuttings or soughed material from the bottom of the hole before placement of the pier. It may be desired to drive the pier through any material at the bottom of the shaft. A cup may be connected to the bottom end of the pier to prevent the pier from cutting into the formation.
A slab bracket is provided for attachment to a side of the foundation to be supported. The side of the foundation may be exposed at the soil surface, by excavating soil from the perimeter of the foundation or cutting through the foundation. The present invention does not require support of the foundation from the underside of the foundation. The slab bracket is positioned above the drilled shaft and the positioned pier.
The slab bracket includes a face plate adapted for placement against the face of the foundation to be raised and a support plate extending outwardly from the face plate and foundation. The slab bracket may be connected to the foundation with bolts extending through the faceplate into the foundation. It may further be desired to utilize a cementing agent, such as an epoxy, to secure the bolts within the foundation. It may further be desired to have stabilizing legs positioned between the faceplate and the support plate of the slab bracket.
A jacking bracket is functionally connected to the top end of the pier and positioned below the support bracket of a slab bracket. The jacking bracket includes a shelf that may be connected by welding to a main post having a diameter for snugly disposing a portion of the top end of the pier therein. The jacking bracket may be connected to the pier in various manners including disposing a portion of the pier into the jacking bracket, welding the jacking bracket to the pier or threading the jacking bracket on the pier or a combination of methods. It is desirable to have a jacking bracket readily connectable to the pier after positioning the pier at a desired height. The current system desirably allows placement and securement of the pier in the shaft, and then a top portion of the pier may be removed at a level to attach the jacking bracket to achieve a sufficient spacing between the jacking and slab bracket for positioning of lifting and/or securement mechanisms.
It is desired to provide a space between the jacking and slab bracket for providing mechanisms for lifting and securing the foundation. The space provided allows the placement of a lifting mechanism such as, but not limited to, a hydraulic jack for raising the foundation to a desired location. Once the foundation is positioned in a desired location a supporting mechanism may be placed and/or connected between the jacking bracket and the slab bracket to maintain the foundation in a position relative to the supporting formation. The supporting mechanism may include concrete blocks and/or metal shims.
The present invention accomplishes placement of a pier between a foundation to be supported and a desired supporting ground formation by confirming existence of the supporting formation and the depth to the supporting formation. The present invention provides support a structure irrelevant of the characteristics of the soil or medium immediately underlying the structure.
The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic of the foundation lifting and supporting system of the present invention;
FIG. 2 is a perspective view of a slab bracket of the present invention;
FIG. 3 is a perspective view of a jacking bracket of the present invention; and
FIG. 4 is a schematic of an example of the foundation lifting and supporting system.
DETAILED DESCRIPTION
Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
FIG. 1 is a schematic drawing of the system for lifting and supporting foundation of the present invention generally designated by the numeral 10 . System 10 includes a drilled pier 12 , a jacking bracket 16 and a slab bracket 18 .
Pier 12 is desirably a pipe having a sufficient length to reach from a foundation 20 , such as a slab, to be raised and bedrock 22 . Pier 12 is positioned in a drilled shaft 14 drilled from the surface of the soil into bedrock 22 . Pier 12 may be a single stand of pipe or multiple connected stands of pipe connected by welding, threading or other known methods of connection. The schedule of pipe chosen is based on the load to be supported by pier 12 . Unlike driven pier systems any desired diameter of pipe may be used. Pier 12 has a top end 24 and a bottom end 26 . If may be desired to connect an end cap 28 to bottom end 26 of pier 12 to increase stability of pier 12 and to prevent pier 12 from cutting into bedrock 22 .
As will be more readily understood throughout the description, the jacking bracket of the present invention can be constructed in varying embodiments for the particular project. An embodiment of jacking bracket 16 , shown in detail in FIG. 3, is connected to top end 24 of pier 12 for supporting a lifting mechanism for lifting foundation 20 . With additional reference to FIG. 3 jacking bracket 16 is shown having a shelf 30 , main post 32 and gussets 34 . Shelf 30 is desirably constructed of a metal sheet having sufficient strength to lift a portion of foundation 20 and any carried structure without substantial deformation. Support post 32 is connected to and extends downward from the center point of the underside of shelf 30 for connecting to pier 12 and to transfer the load carried on shelf 30 to pier 12 . To increase the strength and stability of shelf 30 gussets 34 may be connected between support post 32 and shelf 30 .
Jacking bracket 16 is connected atop pier 12 to provide a surface for lifting slab 20 and transferring the load to pier 12 and to bedrock 22 . In a preferred embodiment support post 32 has a diameter sufficient to dispose top end 24 and a portion of pier 12 therein. Jacking bracket 16 may be further secured to pier 12 by tack welding or other methods. This type of connection permits the cutting off of a portion pier 12 to a desired length and providing a stable connection between pier 12 and jacking bracket 16 . Other methods of connecting jacking bracket 16 to pier 12 without departing from the scope of the invention may be utilized.
Slab bracket 18 is adapted to be connected to a side 36 of slab 20 and in a preferred embodiment is not connected to the underside 38 of slab 20 . Side 36 of slab 20 may be the periphery of slab 20 or a portion of slab 20 cut away. Slab bracket 18 is connected to slab 20 utilizing anchoring bolts 40 . It is desirable to secure anchoring bolts 40 with an adhesive such as Hilti HIT HY-150, a fast curing two-part adhesive anchor system for concrete.
With reference to FIGS. 1 and 2 varying embodiments of slab bracket 18 are shown. Slab bracket 18 includes a face plate 42 , support plate 44 and a pair of legs 46 . Face plate 42 is a substantially vertical member for disposing on slab side 36 . Support plate 44 extends substantially horizontally away from face plate 42 . Support plate 44 is adapted to be connected to jacking plate 16 by lifting mechanisms during the lifting operations and by support mechanisms after lifting operations are completed. Lifting and supporting mechanisms are not shown in detail but are generally designated by the box labeled 48 . Support plate 44 may further be strengthened by legs 46 . As shown in FIGS. 1 and 2, support plate 44 may be extend from face plate 42 in varying locations to facilitate the transfer of load from slab 20 to pier 12 and directing the forces into slab 20 as opposed to pushing bracket 18 away from slab 20 .
FIG. 4 is schematic of a foundation lifting and support method and system of the present invention. System 10 was utilized in a limited access manufacturing facility wherein there were both vertical and horizontal space limitations and an extremely heavy load requirement. Slab 20 is an interior foundation for equipment requiring lifting and leveling. The depth to rock 22 was twelve feet and slab 20 is four feet thick. Thirteen individual systems 10 a are shown spaced around the periphery of slab 20 . Four inch shafts 14 were drilled spaced approximately six feet apart. Eleven of the systems 10 a utilized 2¾ inch pipe for piers 12 and two of the systems utilized 3 inch pipe for piers 12 . Jacking brackets 16 were constructed to correspond to the appropriate pier 12 size. Slab brackets 18 were fabricated for a 4 feet thick slab 20 . The estimated lifting weight per pier was 35,000 pounds.
A method of lifting and supporting a foundation is now described with reference to FIGS. 1 through 4. A foundation 20 is evaluated to determine the remedial action that must be taken such as lifting and leveling. The load to be lifted and the thickness of the foundation is determined. Locations for piers 12 are determined. If a pier 12 is to be positioned within the perimeter of slab 20 , a hole is cut through slab 20 to expose slab side 36 and the underlying soil. A portion of soil 15 is excavated so as to expose slab side 22 and to a depth and width sufficient for drilling and placement of jacking bracket 16 and slab bracket 18 . A hole or shaft 14 is drilled, substantially vertically, from the surface of the soil 15 to bedrock 22 or other desired supporting formation. It is desirable to drill shaft 14 partially into formation 22 utilizing a dirt bit until creation of a shaft is prevented by the foundation. It may be determined that the desired formation 14 has been encountered by viewing and/or testing the cuttings removed from shaft 14 and by prevention of drilling by the formation. Once the total depth of shaft 14 is achieved it is desirable to remove the debris in shaft 14 . Pipe is run into shaft 14 to form a pier 12 . The pier may be driven through the silt and material in the bottom of shaft 14 . It may be desired to connect an end cap to the bottom end 26 of pier 12 to prevent pier 12 from cutting into formation 22 . Pier 12 can then be leveled and secured, such as by back fill, in shaft 14 . A portion of the top end 24 of pier 12 may be cut to achieve the desired height of pier 12 .
Jacking bracket 16 is connected to top end 24 of pier 12 by disposing support post 32 over pier 12 . Jacking bracket 16 may be further secured to pier 12 .
Slab bracket 18 is connected to slab side 36 by anchoring bolts 40 and desirably with an adhesive to further secure bolts 40 depending on the foundation material. Slab bracket 18 is connected so that support plate 44 extends out from slab side 36 and is positioned over shelf 30 of jacking bracket 16 .
A lifting mechanism 48 , such as a hydraulic jack, is placed between shelf 30 of jacking bracket 16 and support plate 44 of slab bracket 16 . Lifting mechanism 48 is operated until slab 20 has been raised to the desired level. Once the desired restoration of foundation 20 is achieved the lifting mechanisms may be replaced with support mechanisms 48 . The system and method of the present invention provides a stable and secure support between a desired supporting formation 22 .
From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a method and system for lifting and supporting a foundation has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow. For example, a slab is not limited to a concrete foundation but may include a wood, steel or other type of supporting structure. | A method and apparatus for lifting and stabilizing a foundation including a pier having a top end and a bottom end, the pier being disposed in shaft drilled proximate the foundation to a desired underground formation suitable for supporting the foundation, a slab bracket connected to a side of the foundation and not supporting the foundation from the underside thereof, a jacking bracket attached to the top end of the prier and positioned below the slab bracket, and means for supporting the foundation positional between the jacking bracket and the slab bracket. | 4 |
BACKGROUND
The present disclosure relates to swimming pools and more particularly to the retainment of a water tight liner used in the construction of swimming pools. More particularly, the present disclosure relates to a locking tab used to secure the liner to a stair assembly of a swimming pool.
SUMMARY
In accordance with the present disclosure, a swimming pool liner is provided to be secured to a stair assembly of a swimming pool through the use of one or more locking tabs secured to an underside of the pool liner. The locking tabs are configured to be attached to the underside of the pool liner at predetermined locations that correspond to channels formed in the stair assembly, the locking tabs including a free-hanging tab extension that can be inserted into the channels to secure the pool liner against the stair assembly.
In illustrative embodiments, the pool stair assembly includes one or more step members. Each step member includes a riser panel, a tread panel extending behind and away from the riser, and a connection flange coupled to the tread panel. The connection flange of a first step member is placed in parallel alignment with the riser panel of a second, adjoining step member when multiple step members are coupled together to create a multi-step stair structure. A plurality of spacers is located between the connection flange of the first step member and the riser panel of the second step member such that a channel is formed when the connection flange and riser panel are coupled together, the channel being parallel with a back edge of the tread panel of the first step member. One or more detents extend into the channel and are spaced apart from each other along the channel.
In illustrative embodiments, locking tabs secured to an underside of the pool liner are located at predetermined positions to generally align with the channel formed in the stairs when the swimming pool liner is aligned correctly with the stair assembly. When the locking tab is inserted into the channel, a lip of the locking tab is compressed to allow the lip and a tab extension, coupled to the lip, to move past the detent when sufficient downward force is applied. The lip will be naturally biased back to its original position after passing the detent, abutting against a bottom side of the detent to prevent removal of the locking tab from the channel.
Additional features of the disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description particularly refers to the accompanying figures in which:
FIG. 1 is an front partial perspective view of a swimming pool with a stair assembly in accordance with the present disclosure;
FIG. 2 is a front perspective view of a series of step members of the stair assembly of FIG. 1 , the step members coupled together to form a multi-step stair structure;
FIG. 3 is a cross-sectional view of a pool liner and a locking tab coupled to the bottom of the pool liner, the pool liner and locking tab configured to be coupled together with the step members of FIG. 2 to form the stair assembly of FIG. 1 ;
FIG. 4 is an exploded perspective view of the stair assembly of the present disclosure, the stair assembly including spacers molded into a step member to form a channel between the step members, the channel configured to receive a locking tab;
FIG. 5 is an assembled perspective view of the stair assembly of FIG. 4 ;
FIG. 6 is an exploded perspective view of an alternative embodiment of the stair assembly of the present disclosure, the stair assembly including spacers stamped into the step member to form a channel to receive the locking tab;
FIG. 7 is an exploded perspective view of an alternative embodiment of the stair assembly of the present disclosure, the stair assembly including separate spacers to form a channel to receive the locking tab;
FIG. 8 is a cross-sectional side view of the stair assembly of FIG. 4 prior to assembly;
FIG. 9 is a cross-sectional side view of the stair assembly of FIG. 4 after the step members are assembled together to form the channel but prior to insertion of the locking tab into the channel;
FIG. 10 is a cross-sectional side view of the stair assembly of FIG. 4 after the locking tab has been inserted into the channel and a lip of the locking tab abuts against a detent extending into the channel, blocking upward movement of the locking tab;
FIG. 11 is a cross-sectional side view of a portion of the step member of FIG. 6 , showing the step member includes a detent and spacer formed from a stamping process;
FIG. 12 is a cross-sectional view of a portion of the step member of FIG. 4 , showing the step member includes a detent and spacer formed from a molding process;
FIG. 13 is a cross-sectional view of a portion of the step member of FIG. 7 , showing the step member includes a detent formed from a stamping process, a separate spacer being secured to the step member;
FIG. 14 is a detailed view of the interaction between the locking tab and the detent of FIG. 10 ; and
FIG. 15 is an exploded full view of the stair assembly of FIG. 4 .
DETAILED DESCRIPTION
In illustrative embodiments, a pool stair assembly 10 includes one or more step members 12 , a pool liner 14 secured to step member 12 , and a locking tab 16 coupled to a bottom surface 28 of pool liner 14 to secure liner 14 to step members 12 . As illustrated in FIGS. 1 and 2 , step members 12 are configured to be coupled together to allow stair assembly 10 to ascend from a first level 111 aligned with a base 102 of a swimming pool 100 to a higher second level 112 aligned with a surface 104 of the area surrounding swimming pool 100 . As illustrated in FIGS. 4 and 5 , locking tab 16 is configured to be inserted into a channel 11 between step members 12 when step members 12 are coupled together. Once inserted into channel 11 , locking tab 16 is difficult to remove from step members 12 , preventing pool liner 14 from unintentionally slipping or moving with respect to step members 12 .
Each step member 12 of pool stair assembly 10 includes a tread panel 20 , a riser panel 22 coupled to tread panel 20 , and a connection flange 24 coupled to tread panel 20 at a point spaced away from where riser panel 22 couples to tread panel 20 , as illustrated in FIG. 15 . In the illustrative embodiments, tread panel 20 is generally parallel with base 102 of swimming pool 100 . Riser panel 22 and connection flange 24 are generally parallel with each other and generally perpendicular to base 102 of swimming pool 100 and tread panel 20 .
Tread panel 20 includes a top surface 40 , a bottom surface 42 , a front edge 44 , and a back edge 46 , as illustrated in FIGS. 4 and 15 . Riser panel 22 includes a front surface 50 , a back surface 52 , a top edge 54 , and a bottom edge 56 , as illustrated in FIGS. 4 and 15 . Connection flange 24 includes a front surface 60 , a back surface 62 , a top edge 64 , and a bottom edge 66 , as illustrated in FIG. 4 . In illustrative embodiments, top edge 54 of riser panel 22 is coupled to front edge 44 of tread panel 20 , and back edge 46 of tread panel 20 is coupled to top edge 64 of connection flange 24 . Each step member 12 is generally identical to other step members 12 in stair assembly 10 .
When two step members 12 a and 12 b are coupled together, stair assembly 10 is formed to include channel 11 between back edge 46 a of tread panel 20 a of a first step member 12 a and riser panel 22 b of a second step member 12 b , as illustrated in FIGS. 4-10 . In an illustrative embodiment and as illustrated in FIG. 7 , channel 11 may be formed by including a plurality of spacers 18 between connection flange 24 a of first step member 12 a and riser panel 22 b of second step member 12 b . In another illustrative embodiment, channel 11 may also be formed by molding or stamping riser panel 22 b to form a plurality of spacers 18 that bulges out from front surface 50 b of riser panel 22 b into channel 11 to abut against back surface 62 a of connection flange 24 a , as illustrated in FIGS. 4 , 6 , and 8 - 10 . Similarly, channel 11 may also be formed by molding or stamping connection flange 24 a to form a plurality of spacers 18 that bulges out from back surface 62 a of connection flange 24 a into channel 11 to abut against front surface 50 b of riser panel 22 b . Other known methods of forming channel 11 when connection flange 24 is coupled to riser panel 22 may be applicable or apparent to those skilled in the art in view of the foregoing description.
In a first illustrative embodiment, front surface 50 of riser panel 22 includes a detent 48 near bottom edge 56 that is configured to extend partially into channel 11 , as illustrated in FIG. 9 . When connection flange 24 is coupled to riser panel 22 , detent 48 is located between bottom edge 56 of riser panel 22 and top edge 54 of connection flange 24 a . Detent 48 may be located between spacer 18 and top edge 54 of connection flange 24 a . In a second, alternative illustrative embodiment, back surface 62 of connection flange 24 may include detent 48 near top edge 64 , detent 48 similarly configured to extend partially into channel 11 .
Locking tab 16 includes an elongated web 30 , a free-hanging tab extension 32 coupled to elongated web 30 , and a lip 34 coupled to tab extension 32 . As illustrated in FIGS. 3 and 8 - 10 , elongated web 30 includes a bonded section 36 and a free section 38 . Bonded section 36 is coupled to bottom surface 28 of pool liner 14 at predetermined positions along pool liner 14 to align tab extension 32 with channel 11 when liner 14 is placed over step members 12 to assemble pool stair assembly 10 . Free section 38 is spaced away from bottom surface 28 of pool liner 14 . Elongated web 30 may be coupled to bottom surface 28 by any known means of coupling or bonding, including but not limited to welding, adhesive or application of heat between elongated web 30 and bottom surface 28 . In illustrative embodiments, free-hanging tab extension 32 , elongated web 30 , and lip 34 may be formed of one unitary piece such that locking tab 16 is one molded component.
Free-hanging tab extension 32 is coupled to free section 38 of elongated web 30 such that free section 38 extends between bottom surface 28 and tab extension 32 , as illustrated in FIG. 3 . Tab extension 32 is configured to be inserted into channel 11 when connection flange 24 a of first step member 12 a is coupled to riser panel 22 b of second step member 12 b . Tab extension 32 includes a connection panel 70 and an insertion tang 72 , as illustrated in FIG. 3 . Connection panel 70 is coupled to free section 38 such that insertion tang 72 is spaced away from free section 38 when tab extension 32 is coupled to elongated web 30 . Insertion tang 72 has a first side wall 74 and a second side wall 75 , with the distance between first side wall 74 and second side wall 75 being D2, as illustrated in FIG. 3 . Similarly, connection panel 70 has a first side wall 76 and a second side wall 77 , the distance between first side wall 76 and second side wall 77 being D1. Second side wall 75 of insertion tang 72 and second side wall 77 of connection panel 70 may be coplanar and formed as a unitary surface.
As illustrated in FIGS. 3 , 8 - 10 , and 14 , lip 34 of locking tab 16 is coupled to first side wall 74 of insertion tang 72 and extends outward and away from first side wall 74 . A tip 58 of lip 34 and insertion tang 72 define a pocket 80 of locking tab 16 . In the natural state of lip 34 , the distance between tip 58 of lip 34 and second side wall 77 is configured to be D3, with D3 being a greater than distance D2, as illustrated in FIG. 3 . Lip 34 is configured to be generally flexible with respect to insertion tang 72 and is configured to move into pocket 80 when compression force is applied to lip 34 .
In use of stair assembly 10 , channel 11 is configured to have a width W1, where width W1 is measured as the distance between front surface 50 of riser panel 22 and back surface 62 of connection flange 24 , as illustrated in FIG. 9 . As illustrated, detent 48 may be coupled to front surface 50 of riser panel 22 such that detent 48 extends into channel 11 , creating a distance W2 between detent 48 and back surface 62 of connection flange 24 , as illustrated in FIG. 9 . In an alternative embodiment, detent 48 may be coupled to back surface 62 and extend into channel 11 such that distance W2 may exist between detent 48 and front surface 50 of riser panel 22 . W2 is configured to be less than W1.
Width W2 is configured to be equal to or slightly larger than distance D2 so to allow insertion tang 72 of tab extension 32 to fit inside channel 11 in a snug manner such that walls 74 and 75 of insertion tang 72 frictionally engage with detent 48 and front surface 50 in illustrative embodiments. As locking tab 16 is inserted into channel 11 , lip 34 is compressed into pocket 80 by engagement with detent 48 , causing the distance between tip 58 of lip 34 and second side wall 77 to decrease to approximately the distance D2. Once lip 34 is compressed, insertion tang 72 can slide further into channel 11 and past detent 48 . As illustrated in FIG. 10 , after insertion tang 72 has slid past detent 48 , the natural bias of lip 34 will bias lip 34 out of pocket 80 , allowing the distance between tip 58 of lip 34 and second side wall 77 to return to the distance D3. As such, tip 58 of lip 34 will abut against a bottom side 49 of detent 48 , blocking locking tab 16 from upward movement out of channel 11 .
In alternative embodiments, connection flange 24 may be coupled to riser panel 22 b of step member 12 b instead of tread panel 20 a of step member 12 a . In such an embodiment, connection flange 24 b may be coupled to bottom edge 56 b of riser panel 22 b to be perpendicular to riser panel 22 b and extend in a direction towards back edge 46 b of tread panel 20 b . Connection flange 24 b would be generally parallel to tread panel 20 a of neighboring step member 12 a , and would be coupled to tread panel 20 a to form channel 11 between connection flange 24 b and tread panel 20 a . Thus, channel 11 may be formed in either vertical or horizontal planes of step members 12 to provide means for locking tab 16 to be inserted into channel 11 for securement of pool liner 14 . In another alternative embodiment, connection flange 24 may be a separate component from riser panel 22 and tread panel 20 of step members 12 , with connection flange 24 being coupled to either riser panel 22 or tread panel 20 during installation of step member 12 to form stair assembly 10 . Other methods of forming a gap or channel 11 between step members 12 may be known to one skilled in the art in light of this disclosure. Lip 34 may be coupled to one side of locking tab 16 to configure lip 34 to engage with detent 48 if detent 48 is located on the front surface 50 of riser panel 22 or on the opposite side of locking tab 16 to configure lip 34 to engage with detent 48 if detent 48 is located on the back surface 62 of connection flange 24
Step members 12 may be coupled together in any known method of coupling. In illustrative embodiments and as illustrated in FIGS. 4-10 , riser panel 22 and connection flange 24 may be coupled together by means of a fastener assembly 120 . Fastener assembly 120 may be located between the bottom edge 56 of riser panel 22 and detent 48 and extend through channel 11 . Fastener assembly 120 may include a bolt 121 that extend through apertures 123 formed in riser panel 22 and connection flange 24 and is secured by a nut 122 ′, as illustrated in FIGS. 4-10 . Fastener assembly 120 may also include other mechanical means of connecting step members 12 . Further, spacer 18 may be secured between riser panel 22 and connection flange 24 by fastener assembly 120 . Other embodiments of fastener assembly 120 are also envisioned.
The configuration of locking tab 16 and its attachment to bottom surface 28 of pool liner 14 at predetermined locations enables a substantial portion of locking tab 16 to be inserted into channel 11 when pool liner 14 is coupled to step members 12 . When pool liner 14 is coupled to step members 12 , a bend 15 is naturally created in pool liner 14 as pool liner 14 covers tread panel 20 and riser panel 22 that are perpendicular to each other. In illustrative embodiments, bend 15 is located generally above channel 11 . As illustrated in FIGS. 10 and 14 , the configuration of locking tab 16 to enable a substantial portion of locking tab 16 to be inserted into channel 11 enables bend 15 of pool liner 14 to have a relatively smooth concave surface free of any interruptions as it extends over tread panel 20 , across channel 11 , and over riser panel 22 .
In accordance with the present disclosure, a pool stair assembly 10 is provided comprising a first step member 12 a having a first tread panel 20 a , a first riser panel 22 a that is generally perpendicular to the first tread panel 20 a , and a connection flange 24 a coupled to the first tread panel 20 a ; a second step member 12 b having a second tread panel 20 b and a second riser panel 22 b that is generally perpendicular to the second tread panel 20 b ; a pool liner 14 having a top surface 26 and a bottom surface 28 ; a locking tab 16 coupled to the bottom surface 28 of the pool liner 14 ; wherein the connection flange 24 a of the first step member 12 a is adapted to be coupled to the second riser panel 22 b of a second step member 12 b to form a channel 11 therebetween, the channel 11 configured to accept the locking tab 16 coupled to the pool liner 14 to retain the pool liner 14 against the stair assembly 10 to prevent unwanted movement of the pool liner 14 with respect to the first and second step members 12 a , 12 b ; and wherein the locking tab 16 is configured to be coupled to the bottom surface 28 of the pool liner 14 at predetermined locations that correspond with the channel 11 , the locking tab 16 configured to allow the pool liner 14 above the channel 11 to form a smooth concave bend 15 as it extends from the first tread panel 20 a to the second riser panel 22 b across the channel 11 .
The pool stair assembly 10 includes a detent 48 that extends into the channel 11 from either the second riser panel 22 b or the connection flange 24 a to retain the locking tab 16 in the channel 11 , and the detent 48 may be stamped or molded into the second riser panel 22 b or the connection flange 24 a . The detent 48 extends approximately one-half the distance of the width W1 of channel 11 . The detent 48 may be located closer to the first tread panel 20 a of the first step member 12 a than a bottom edge 56 b of the second riser panel 22 b of the second step member 12 b when the first step member 12 a and second step member 12 b are coupled together. A series of spaced apart detents 48 may extend into channel 11
The channel 11 of pool stair assembly 10 may be formed between the second riser panel 22 b and the connection flange 24 a by a spacer 18 located between the second riser panel 22 b and connection flange 24 a when the second riser panel 22 b and the connection flange 24 a are coupled together. The spacer 18 may be stamped from or molded with the second riser panel 22 b or the connection flange 24 a . The spacer 18 may be located between a bottom edge 56 b of the second riser panel 22 b and the detent 48 extending into the channel 11 . The second riser panel 22 b and connection flange 24 a may be coupled together by a fastener assembly 120 located between the bottom edge 56 b of the second riser panel 22 b and the detent 48 .
The locking tab 16 of pool stair assembly 10 may include an elongated web 30 and a free-hanging tab extension 32 . The elongated web 30 may be coupled to the bottom surface 28 of the pool liner 14 and the tab extension 32 may be coupled to the elongated web 30 to be free-hanging. The tab extension 32 may include a connection panel 70 and an insertion tang 72 , and the elongated web 30 may be coupled to the connection panel 70 such that the insertion tang 72 is spaced away from the elongated web 30 . A lip 34 may be coupled to the insertion tang 72 to extend away from the insertion tang 72 . The lip 34 may engage with the detent 48 extending into the channel 11 to retain the locking tab 16 within the channel 11 .
The locking tab 16 may be coupled to the pool liner 14 after the pool liner 14 has been fully assembled. The locking tab 16 may be welded to the pool liner 14 or may be connected to the pool liner 14 by any other means known in the art.
In alternative embodiments, locking tab 16 and pool liner 14 may be configured to be secured to different components of a swimming pool 100 that are similar in shape to step member 12 , such as a bench or sun ledge. Locking tab 16 may be configured to be received by any components that include a means for forming a channel 11 when coupled together.
Although directional language may be used throughout the specification, such directions are intended to convey the scope of the present disclosure rather than limit the scope of the present disclosure. It should be understood that a direction, such as up, down, back, front, etc., may change depending on the orientation of one or more components of the travel golf bag disclosed herein.
Various features of the disclosure have been shown and described in connection with the illustrated embodiment, however, it is understood that these arrangements merely illustrate, and that the disclosure is to be given its fullest interpretation. | A pool stair assembly includes step members having riser panels and tread panels, the step members joined together to form a multi-step structure. In illustrative embodiments, a spacer is located between a connection flange of a first step member and a riser panel of a second step member to form a channel therebetween, with one or more detents extending into the channel. A swimming pool liner includes locking tabs at predetermined locations that correspond to the channel, the locking tabs insertable into the channel to secure the liner to the step members. When the locking tab is inserted, a lip of the locking tab is compressed against the detent to move the locking tab past the detent when sufficient downward force is applied. The lip naturally biases back to its original position after passing the detent, preventing removal of the locking tab from the channel. | 4 |
FIELD OF THE INVENTION
This invention relates generally to a method of constructing a plated pile knit fabric on a circular knitting machine and to the sinkers used thereon, and more particularly to such a method wherein the sinkers are obliquely movable and include a forward end portion having a throat to define a sinker nose positioned above the throat and a horizontally extending upper pile position control edge positioned rearwardly of the nose for engaging a pile yarn and a sinker top knitting ledge defined by a lower surface of the throat for engaging a ground yarn so as to properly position the ground yarn onto a knitting needle and ensuring plating of the fabric.
BACKGROUND OF THE INVENTION
In conventional single unit circular knitting machines, the sinkers include a nose which is in a high position thereon for knitting a plated pile fabric. The position of the nose and a control ledge on the sinker determines the desired length of the pile because as the pile yarn engages the nose and is caught thereon the yarn is spaced a set distance to the lower ledge defined by the sinker throat so as to establish the height of the formed pile. Typically, in a pile knitting machine, two yarns, a ground yarn and pile yarn, are fed during one cycle of a knitting operation. The two yarns serve as respective upper and lower yarns and are fed by means of appropriate yarn feeders and guides. In accordance with conventional methodology, the first yarn is fed to the needle while the second yarn is fed to the sinker top knitting ledge. Both yarns are caught by the needle hook when the sinker is pushed forward. The lower yarn is received onto the sinker top knitting ledge and the upper yarn is received onto the sinker nose positioned above the sinker top knitting ledge so as to aid in forming the desired height of the plated pile fabric.
As the needle is lowered to a distance below the sinker top knitting ledge, the two yarns received on the sinker form two sinker loops which are spaced according to the vertical distance between the respective parts of the sinker into which the yarns are received. The sinker loop of the upper yarn becomes the pile knit loop and the lower yarn, commonly referred to as the ground yarn, forms the ground knit loop. To knit a plated pile fabric as described above, the ground yarn must be fed to the needle hook and moved by the advancing sinker against the inner side of the needle hook. Additionally, the pile yarn received onto the sinker nose must be retained on the outer side of the needle hook adjacent the latch by the sinker. To form the plated pile fabric, it is necessary to stably position both the pile yarn and ground yarn onto the needle hook.
In accordance with the prior art, three methods conventionally have been used for stable positioning of the ground yarn onto the inner side of the needle hook. In the first prior art method, the sinker includes a throat which forcibly pushes the ground yarn toward the inner side defined by the needle hook so as to position the yarn thereat to form the plated pile knit fabric. In the second method, one of two sinkers inserted into one sinker groove positions the ground yarn onto the inner side defined by the needle hook. The sinker forcibly pushes the yarn to force the yarn into a stable position against the inner side of the needle hook. In the third method, the sinker includes an inclined surface on a top portion thereof which engages the ground yarn to draw the yarn downward. The sinker moves back and forth in a radial direction of the cylinder and forcibly positions the ground yarn onto the inner side of the needle hook. As the ground yarn is forcibly pushed against the inner side of the needle hook, it is stably positioned thereat.
The first and second methods cause yarn breakage in many instances. Additionally, associated knots or lints can be knitted into the fabric to create unacceptable defects. Also, as the ground yarn is positioned on the inner side of the needle hook, it usually is brought into this position by the sinker throat so that the yarn is nipped or caught by the sinker throat and needle. Additionally, if the knit density or the type of yarn must be changed, a skilled operator must make the finite adjustments to the sinker cam for establishing the distance in which the sinker is pushed and for establishing the timing movement of the sinker. This manual operation typically takes a prolonged period and any mistake made in the adjustment of the sinker cam effects the plating property yielded by the pile and ground yarns. Typically, knitting bars also appear along the course direction of the knit. In the third method, the inclined surface of the sinker top knitting ledge pushes the ground yarn. This also can create knitting bars, especially when the distance the sinker travels is incorrectly adjusted.
SUMMARY OF THE INVENTION
It is therefor an object of this invention to provide a method of constructing a plating pile knit fabric where manual adjustment of the sinker cam for effecting changes to the travel distance of the sinker or timing thereof is not necessary when the knitting density or type of yarn is changed.
It is another object of this invention to provide a sinker for use on a circular knitting machine which is novel in shape and adapted to produce a plated pile knit fabric having low piles.
These and other objects and advantages of the present invention are accomplished by the method of constructing a plated pile knit fabric on a circular knitting machine which is adapted for feeding a ground yarn and a pile yarn. The knitting machine includes sinkers obliquely movable from an advanced, innermost lower position to a receded, outermost upper position for aiding in forming low piles during the construction of the knit fabric. Each sinker includes a forward end portion having a throat extending transversely inwardly thereat to define a sinker nose positioned above the throat. A substantially horizontally extending upper pile position control ledge is positioned rearwardly of the nose for engaging a pile yarn and determining a height of the formed pile yarn loop. A sinker top knitting ledge is defined by the lower surface of the throat for engaging a ground yarn and properly positioning the yarn onto a knitting needle and insuring plating of the knit fabric.
A ground yarn and pile yarn are fed to a raised, open latch needle having previously formed ground yarn loops and pile yarn loops positioned on the needle stem. The needle is lowered so that the previously formed ground yarn loops and pile yarn loops retained on the needle rise on the needle stem and close the needle latch onto the ground and pile yarns fed thereto. Additionally, the sinker is obliquely advanced so that the pile yarn is received onto the upper pile position control ledge of the sinker. The ground yarn is received into the sinker throat and onto the sinker top knitting ledge. Both yarns are positioned higher than the hook of the needle.
The ground yarn is transferred to the inner side of the needle hook by further advancing the sinker as the needle is lowered so that the ground yarn received in the sinker throat is moved forwardly toward the inner side of the needle hook as the sinker advances. The needle is lowered to clear the previously formed ground and pile yarn loops from the needle while tightening the cleared loops with the sinker by advancing the sinker to the most advanced, innermost lower position. The needle is raised so that the formed pile and ground loops are transferred to the needle stem and the sinker is receded after the needle reaches a desired safety level so that as the needle is raised, the upper pile position control ledge and the sinker top knitting ledge is positioned lower than the needle hook. The formed pile loop received onto the pile position control ledge is then cleared therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages will appear as the description proceeds when taken in connection with the accompanying drawings, in which
FIG. 1 is a vertical sectional view through the needle cylinder of the knitting machine and illustrating the manner in which the sinkers are mounted for radial sliding movement along a downwardly inclined path of travel relative to the needles;
FIG. 2 is a side elevational view of one of the special type of sinkers utilized in the present invention;
FIG. 3 is a fragmentary side elevational view of the forward yarn engaging end of the sinker in accordance with the present invention and showing schematically a comparison with a conventional type of sinker, the conventional type of sinker being shown in dashed-dot lines;
FIG. 4 is an enlarged side elevational view of the needle and showing the position of the ground and pile yarns caught therewithin;
FIG. 5 is a somewhat schematic developed elevational view showing the paths of travel of the needles and the associated sinkers at the ground and pile yarn feeding positions;
FIG. 6 is a fragmentary side elevational view of a needle and the forward yarn engaging end of an associated sinker;
FIGS. 7-14 are side elevations of the upper portions of the needles and associated sinkers showing their relationship during the successive steps of forming the plated pile knit fabric in accordance with the present invention and the shedding of the previously formed ground and pile yarn loops from the needles, and being taken along the respective section lines 7-14 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a rotating needle cylinder 1 is supported by a driven ring gear 12. The outside surface of the needle cylinder surface 1 is provided with the usual needle slots 1a in which hooked latch needles, broadly indicated at 2, are supported for vertical movement parallel to the axis of rotation of the needle cylinder 1. Each knitting needle is provided with a pivoted latch 2a, operating butt, as indicated at 2c (FIG. 1), and a hook 2b (FIG. 4). A conventional knitting control cam 4 is provided for engaging the butts 2c and imparting vertical movement to the knitting needles 2. The control cam 4 is supported on the inner surface of a cam holder ring 3 which is fixed on a cam ring plate 5.
A sinker nose support ring 6 is fixed on the upper inner surface of the needle cylinder 1 and is provided with a downwardly inclined surface 6a defined by the lower surfaces of sinker slots 6b provided in the upper end of the sinker nose support ring 6. A sinker support bed 7 is fixed to the exterior to the upper end of the needle cylinder 1 and is provided with a downwardly inclined sinker sliding surface 7a defined by the lower ends of sinker slots formed in the sinker bed 7 and at the same downwardly inclined angle as the sinker sliding surface 6a of the sinker nose ring 6.
Special types of sinkers, broadly indicated at 8 in FIG. 2, cooperate with the needles 2 to form knit loops and are supported for movement in a radial direction and along a downwardly inclined path of travel between the needles 2. The inward and outward radial sliding movement of the sinkers 8 along the downwardly inclined path of travel is controlled by sinker cams 10 supported in a fixed position on a sinker cap 9. The sinker cams 10 engage butts 8j on the sinkers to control the downwardly inclined inward and outward movement thereof. The sinker cap 9 is supported on a sinker cap ring 11 which is supported at spaced-apart locations on the upper ends of support standards 13 surrounding the needle cylinder 1. As Will be noted, the sinker cams 10 are supported in a downwardly inclined position at the same downwardly inclined angle as the inclined sliding surfaces 6a and 7a of respective nose ring 6 and sinker bed 7. The sinker sliding surfaces 6a and 7a are illustrated in FIG. 1 as being downwardly inclined at an angle of 20° relative to a line perpendicular to the vertically disposed needles 2. While this 20° downwardly inclined angle is preferred, the present invention is not limited to this particular angular inclination but may be positioned at an angle of from 5° to 60°, and preferably within the range of 10° to 45°.
As best seen in FIG. 2, the special sinker 8 in accordance with the present invention includes an elongate body portion having a main planer sliding edge 8h adapted to rest upon and slide along the inclined surface 7a of the sinker bed 7, and an inner lower additional planer sliding edge 8b adapted to rest on and slide along the inclined sliding surface 6a of the sinker nose ring 6. The forward end of the sinker includes a throat 8c extending transversely inwardly thereat to define a sinker nose 8d positioned above the throat and a substantially horizontally extending pile position control ledge 8f positioned rearwardly of the nose. Positioned forward to the pile position control ledge 8f is a vertical edge 8g. A sinker top knitting ledge 8a is defined by a lower surface of the throat, and as will be explained later in detail, engages a ground yarn to properly position the ground yarn onto a knitting needle for ensuring plating of the knit fabric. An upstanding operating butt 8j is provided on the outer end portion of the elongated body portion of the sinker 8. The butt 8j extends upwardly at a right angle from the body portion of the sinker 8 and is adapted to be engaged by the sinker cams 10 to impart the required inward and outward radial movement to the sinkers 8.
Referring now more particularly to FIG. 3, an enlarged view of the forward yarn engaging portion of the sinker 8 is illustrated. A conventional sinker is depicted in a dash-dot line configuration so as to compare the configuration of the conventional sinker and the sinker 8 in accordance with the present invention. As illustrated, the sinker top knitting ledge 8a declines with respect to the needle as compared to the more conventional sinker. Additionally, the pile position control ledge 8f which determines the height of the pile, extends horizontally in a manner similar to the conventional sinker. As illustrated, the vertical edge 8g and bending point of the nose 8d are positionally lower than the more conventional sinker. Thus, the distance from the bending point of the nose 8d to the pile position control ledge 8f is longer than that of the conventional sinker and permits the pile position control ledge 8f to be positioned correspondingly lower. In accordance with the present invention, a sinker height H1, i.e. the distance between the pile position control ledge 8f and the knitting face, i.e., sinker top knitting ledge 8a, can range under 1.4 millimeters, and more particularly, can range from 1.0 to 1.4 millimeters so as to insure low pile formation. A sinker height H2 of the more conventional sinker ranges approximately from 1.5 to 3.8 millimeters. The construction of the sinker in accordance with the present invention allows low pile formation during construction of the plated pile knit fabric.
Referring now more particularly to FIG. 5, a diagrammatic view illustrating the loci of movements of the cylinder needle and sinker on the knitting machine is shown. FIGS. 7 through 14 are sectional views taken along lines 7--7 through 14--14 in FIG. 5 and illustrate the knitting operation in accordance with the present invention. The solid horizontal transverse line 57 indicates the upper edge surface of the sinker nose ring 6. The continuous line 50 indicates the locus of movement of the hook tip 2b of needle 2. The alternate long and two dashed line 51 indicates the locus of movement of the sinker throat 8c. The alternate long and dashed line 52 indicates the locus of movement for tip of the pile position control ledge 8f. The dotted line 53 indicates the locus of movement of the sinker nose 8d. Reference numerals 54 and 55 indicate feeding positions of respective ground and pile yarns. The yarns 54, 55 are fed to the needles 2 by a respective yarn carrier 18 (FIGS. 1 and 6).
Method of Operation
As the needles 2 successively approach the knitting station, they are successively raised to the clearing level along the solid line 50 in FIG. 5 to a position where the previously formed loops surrounding the shank of the needle are lowered below the tip of the latch (FIG. 14). As a needle 2 is lowered, the corresponding sinker 8 is moved inwardly and downwardly along the downwardly inclined path of travel between the needles so that the fabric is moved inwardly by the nose 8d to maintain the previously formed stitch loop below the tip of the latch 2a and in tight engagement with the shank of the needle as shown in FIG. 8. At this time, the ground yarn 54 is fed through the vertical hole 18a of the yarn carrier 18. The pile yarn 55 is fed through the transverse hole 18b when the needle is at the position shown between FIGS. 7--7 and 8--8 of FIG. 5 during its locus of movement. As the needle is lowered, the ground yarn 54 begins to turn to the closed position by the old loop on the needle shank. The ground yarn 54 is received into the sinker throat 8c and the pile yarn 55 is received onto the pile position control ledge 8f (FIG. 9).
As the needle is lowered further, the old loops close the latch 2a. Both the ground yarn 54 received in the sinker throat 8c and the pile yarn 55 received onto the pile position control ledge 8f are caught by the needle hook 2b. As the needle is further lowered (FIG. 10), the pile yarn 55 is drawn downward by the needle. The sinker 8 advances in an inwardly declining direction and the ground yarn 54 is transferred to the inner side of the needle hook by the sinker top knitting ledge 8a. The advancing sinker 8 engages the ground yarn 54 and positions the yarn on the inner side of the needle hook in a more exact positional relationship with the pile yarn 55 positioned to the outer side in the needle hook (FIG. 4). When the needle is lowered to its lowermost position as shown in FIG. 11, the old loops are shed from the needle. At this point, the ground yarn 54 and the pile yarn 55 are lowered further and loops of respective yarns are formed in accordance with the desired loop length. The old loops cleared therefrom are tightened by the vertical edge 8g as the sinker advances.
The needle 2 then is raised slightly (FIG. 12). When the needle rises, the loops held in the needle are slightly loosened. These loops are tightened by the sinkers 8 which advance to the most oblique, advanced position toward the inner side. The needle further rises (FIG. 13) and the loops held within the needle hook 2b pass the breast of the needle to open the latch 2a. The sinker recedes outwardly therefrom, and the pile loop 55 received onto the pile position control ledge 8f is cleared from the sinker nose 8d and drops therefrom. The sinker rises to its uppermost position (FIG. 14) and the loops which have passed along the breast of the needle 2 slide downwardly along the needle stem and over the tips of the latch 2a. At this point the needle has reached the highest position in the knitting operation.
When the needle is lowered, the loops on the needle stem are positioned inside of the latch 2a as shown in FIG. 7. Another cycle of the knitting operation is begun again. The yarn carrier 18 feeds a new ground yarn 54 and pile yarn 55 to begin again the knitting operation to construct the plated pile knit fabric. Alternatively, a compound needle instead of the preferred latch needle may be used with the requisite modifications made to the knitting machine as needed.
In accordance with the present invention, the oblique movement of the sinker enables exact positioning of the ground yarn and pile yarn toward the respective inner and outer sides of the inner space defined by the needle hook so that when the needle catches these yarns, the yarns are positioned in the needle to ensure proper construction of a plated pile knit fabric. The method in accordance with the present invention includes advantages over prior art methods which require the ground yarn to be pushed toward the inner side of the needle hook or a change in timing movement of the sinker each time the knitting density or kind of ground yarn is modified. Additionally, because the pile position control ledge 8f extends horizontally with respect to the inclination of the sinker in a manner similar to a conventional sinker, and the sinker top knitting ledge 8a declines with respect to the needle as compared to a more conventional sinker, the sinker height can range from 1.0 to 1.4 mm and the bending point between the pile position control ledge and the sinker nose can be positioned lower than that in the conventional sinker.
In the drawings and specification there has been set forth the best mode presently contemplated for the practice of the present invention. Although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims. | A method of constructing a plated pile knit fabric and sinker therefor is disclosed. The sinker is adapted for low pile formation in the construction of the plating pile knit fabric. Each sinker is obliquely movable from an advanced, lower position to a receded, upper position. A pile position control ledge extends horizontally with respect to the incline of the sinker. The distance between the sinker nose and sinker pile position control ledge is more extended than in a conventional sinker, and as a result, the sinker nose can be positioned lower than that in a conventional sinker so as to form low piles. | 3 |
TECHNICAL FIELD
[0001] The present invention relates generally to portable gas skillets and, in particular, to a portable gas skillet having a foldable base for easy transportation and storage.
BACKGROUND ART
[0002] Gas grills are quite popular, especially for backyard or patio cooking. However, they are typically too large, heavy, or awkward to be easily transported, such as to a sporting event for a tailgate party. Many charcoal grills are smaller and lighter and are, therefore, more easily transported. However, charcoal can take a long time to come to grilling temperature from the time it is ignited and the hot coals are difficult and may be dangerous to dispose of after the grilling is finished. Moreover, neither gas grills nor charcoal grills are conducive to being used to cook food in a skillet.
[0003] Camping stoves are relatively portable and allow one to cook food with a skillet. However, they are typically too small to be used to cook for a large number of people at one time.
SUMMARY OF THE INVENTION
[0004] In one embodiment, a portable cooking unit is provided, comprising a frame having an open configuration and a closed configuration. The frame comprises first, second, third, and fourth legs positioned in a rectangular configuration; first and second horizontal braces connected between the first and second legs at vertically spaced apart lower and upper locations, respectively; third and fourth horizontal braces connected between the third and fourth legs at the lower and upper locations, respectively; fifth and sixth horizontal braces connected between the first and fourth legs at the lower and upper locations, respectively; seventh and eighth horizontal braces connected between the second and third legs at the lower and upper locations, respectively. Each of the fifth, sixth, seventh, and eighth horizontal braces comprises first and second sections, both sections having an inner end and an outer end; a hinge joining the first and second sections at their respective inner ends; and first and second pivot brackets at the outer ends of both of the first and second sections, the first and second pivot brackets connecting the first and second sections to the respective legs; whereby, when the frame is in the open configuration and the fifth, sixth, seventh, and eighth horizontal braces are lifted at their respective hinges, the frame moves to the closed configuration. The cooking unit further comprises a firebox removably secured to tops of the first, second, third, and fourth legs of the frame when the frame is in the open configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1A is a side perspective view of an embodiment of a portable gas cooking unit of the present invention;
[0006] FIG. 1B is a side perspective view of the cooking unit of FIG. 1A with the base doors removed;
[0007] FIG. 2A is a top perspective view of an embodiment of a firebox that may be used with the cooking unit of FIG. 1A ;
[0008] FIG. 2B is a bottom perspective view of the firebox of FIG. 2A ;
[0009] FIG. 2C is a side perspective view of the firebox of FIG. 2A being placed onto the base of the cooking unit of FIG. 1A ;
[0010] FIG. 3A is a top perspective view of an embodiment of a burner unit that may be used with the firebox of FIG. 2A ;
[0011] FIG. 3B is a top perspective view of an alternative embodiment of a burner unit that may be used with the firebox of FIG. 2A ;
[0012] FIG. 4A is a top perspective view of an embodiment of a skillet pan that may be used with the cooking unit of FIG. 1A ;
[0013] FIG. 4B is a bottom perspective view of the skillet pan of FIG. 4A ;
[0014] FIG. 5A is a side perspective view of an embodiment of a base that may be used with the cooking unit of FIG. 1A , with the doors opened;
[0015] FIG. 5B is a side perspective view of the base of FIG. 5A with the doors and sides removed;
[0016] FIG. 5C is a side perspective view of a portion of a hinged brace;
[0017] FIG. 5D is a bottom perspective view of the portion of the hinged brace of FIG. 5C ;
[0018] FIG. 5E is an exploded view of the portion of the hinged brace of FIG. 5C ;
[0019] FIG. 5F is a side perspective view of one side of the frame in a partially folded or collapsed position;
[0020] FIG. 5G is a top perspective view of the lower portion of the base of FIG. 5A , including the tank support;
[0021] FIG. 6A is a side perspective view of the base of FIG. 5A in a partially closed or collapsed configuration; and
[0022] FIG. 6B is a side perspective view of the base of FIG. 5A in its fully closed or collapsed configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
[0024] The present invention provides a portable cooking unit with a collapsible or foldable base. Referring to FIG. 1A , the cooking unit 100 may include a firebox 200 , a skillet 400 , and a base 500 . The base 500 may include a rectangular frame 510 ( FIG. 1B ) and, optionally, two hinged doors 502 A, 502 B (collectively identified as 502 ) on two opposing sides of the frame 510 and two fixed panels 504 A, 504 B (collectively identified as 504 ) on the other two opposing sides of the frame 510 . One door 502 A and one panel 504 A are identified in FIG. 1A ; the frame 510 is illustrated without the doors 502 or panels 504 in FIG. 1B ; and the base 500 is illustrated in FIG. 5A with the doors 502 in their open positions resting against the adjacent panels 504 . The frame 510 may include a support 540 to hold a tank 10 which will be out of sight behind the doors 502 and panels 504 when the cooking unit 100 is in use. For convenience in moving the cooking unit 100 , wheels 506 may be secured to the bottom of the base 500 .
[0025] Referring to FIGS. 2A and 2B , the firebox 200 may include a housing 202 and a burner 300 within the housing 202 . The firebox 200 may also include controls, such as a button 204 to push to light the burner 300 and dials 206 used to adjust the flame. It will be appreciated that the controls 204 , 206 and their arrangement that are described and illustrated are meant to be illustrative and not limiting. For example, the burner 300 illustrated in FIG. 2A and in FIG. 3A is comprised of three concentric elements and each element may have its own adjustment dial 206 . In contrast, the burner 310 illustrated in FIG. 3B comprises a single spiral element and therefore uses a single adjustment dial 206 .
[0026] The bottom of the firebox 200 may include feet 208 that may fit into openings at the top of the legs (collectively identified as 512 ) of the frame 510 , as illustrated in FIG. 2C , thereby removably securing the firebox 200 to the base 500 . The firebox may also include handles 210 to provide a convenient way to place the firebox 200 onto the base 500 and to lift the firebox 200 off of the base 500 .
[0027] FIG. 3A illustrates one embodiment of a burner 300 that may be used in the firebox 200 . The burner 300 may include a number of concentric elements, such as three elements 302 A, 302 B, 302 C. FIG. 3B illustrates another embodiment of a burner 310 having a single, spiral element 312 . As will be appreciated, burners having other configurations may be used in the firebox 200 .
[0028] FIGS. 4A and 4B illustrate an embodiment of a skillet 400 that may be used with the cooking unit 100 . The diameter of the skillet 400 may correspond to the diameter of the opening of the firebox 200 . To secure the skillet 400 onto the firebox 200 , tabs or pins 402 may be spaced apart around a rim 404 on the bottom 406 of the skillet. The pins 402 may engage slots 212 ( FIG. 2A ) spaced around the top of the opening of the firebox 200 . When the skillet is then turned (counterclockwise in FIG. 2A ), the pins may secure the skillet 400 to the firebox 200 and prevent the skillet 400 from being dislodged while it is being used to cook food on the cooking surface 408 . The skillet 400 may also include handles 410 spaced apart around the rim to easily move the skillet 400 , especially when it is hot.
[0029] Referring to FIG. 5A , one door 502 A may be secured to one of the legs 512 A of the frame 510 with hinges 520 . The other door 502 B may be secured to the diagonally opposite leg 512 C with hinges (not shown). In their closed positions, the first door 502 A closes against one of the adjacent legs 512 D and the other door 502 B closes against the adjacent leg 512 B (see FIG. 1A ). In FIG. 5A , one door 502 A is shown in its fully open position, having been pivoted approximately 270 degrees from its closed position ( FIG. 1A ) to rest against or adjacent to the outer surface of one of the fixed panels 504 A. The other door 502 B is likewise shown in its fully open position against the outer surface of the other fixed panel 504 B. While the doors 504 are illustrated as being secured to their respective legs 512 with three hinges 508 , it will be appreciated that they may be secured with any number of hinges that is appropriate for the size and weight of the doors 504 . The doors 502 may be kept in their closed position with any type of latch, such as a magnetic latch 514 .
[0030] FIG. 5B illustrates the frame 510 of the base 500 with the doors 502 and fixed panels 504 removed. Four vertical legs 512 A, 512 B, 512 C, 512 D are arranged in a rectangular configuration. Two horizontal fixed braces 516 A, 516 D may be connected between two adjacent legs 512 A, 512 D at upper and lower locations, respectively. Similarly, another two horizontal fixed braces 516 B, 516 C may be connected between the other two adjacent legs 512 B, 512 C at the upper and lower locations, respectively.
[0031] Two horizontal hinged braces 518 A, 518 D may be connected between two adjacent legs 512 A, 512 B at the upper and lower locations, respectively. Similarly, another two horizontal hinged braces 518 B, 518 C may be connected between the other two adjacent legs 512 C, 512 D at the upper and lower locations, respectively. Each hinged brace 518 A, 518 B, 518 C, 518 D may include two sections ( 518 A- 1 and 518 A- 2 , 518 B- 1 and 518 B- 2 , 518 C- 1 and 518 C- 2 , 518 D- 1 and 518 D- 2 , respectively) connected to each other with a hinge at their inner ends and connected to the legs with a hinged bracket at their outer ends.
[0032] In the FIGs., the lower location is approximately at the bottom of the legs 512 and the upper location is approximately one-third of the length of the legs 512 from the top. However, the upper and lower locations may be at other positions along the legs 512 . Additional sets of fixed and hinged braces may also be used depending on the size and weight of the cooking unit 100 .
[0033] FIGS. 5C and 5D are close up views of a portion of two sections 518 A- 1 , 518 A- 2 of a representative hinged brace 518 A. The two sections 518 A- 1 , 518 A- 2 are connected to each other with a hinge 520 at their respective inner ends. The outer ends of the two sections 518 A- 1 , 518 A- 2 are connected to the legs (only one of which 512 B is shown in FIGS. 5C and 5D ) with a hinged bracket 522 . A plate 524 may be secured to the top of the inner end of one of the sections 518 A- 1 of the hinged brace 518 . A pin 526 inserted through a hole 528 in the plate and through a hole 530 in the inner end of the other section 518 A- 2 of the hinged brace 518 A ( FIG. 5E ) locks the two sections 518 A- 1 , 518 A- 2 together in their open position and prevents the hinge 520 from pivoting. When the pin 526 is removed from the holes 528 , 530 and the inner ends of the two sections 518 A- 1 , 518 A- 2 are lifted upward, as illustrated in FIG. 5F , the hinge 520 and hinged brackets 522 pivot and the connected legs 512 A, 512 B are pulled together. When all of the hinged braces 518 A, 518 B, 518 C, 518 D are unlocked and lifted, the two sides of the frame 510 with the fixed braces 516 A, 516 B, 516 C, 516 D move towards each other and the base 500 may be placed in its closed or collapsed position as illustrated FIGS. 6A and 6B .
[0034] FIG. 5G illustrates the lower portion of the frame 510 of the base 500 . The lower portion may include a tank support 540 that may include two fixed braces 542 A, 542 B extending between the hinged braces 518 C, 518 D of the frame 510 , one on each side of the hinges. The tank support 540 may also include two hinged braces 544 A, 544 B extending between the two fixed braces 542 A, 542 B of the tank support 540 . The hinged brace 544 A has two sections 544 A- 1 , 544 A- 2 and the other hinged brace 544 B has two sections 544 B- 1 , 544 B- 2 . As with the hinged braces 518 A, 518 B, 518 C, 518 D of the frame 510 , the two sections of each hinged brace 544 A, 544 B of the tank support 540 may be connected to each other at their inner ends with a hinge and may be connected at their outer ends to the fixed braces 542 A, 542 B with hinge brackets. A clamp, such as a screw clamp 546 , may be used to secure a bottom flange of the tank 10 to the tank support 540 .
[0035] In one embodiment, the skillet 400 has an outer diameter of about 44 inches and the cooking surface 408 has a diameter of about 33 inches. The firebox 200 is about 33 inches on each side; the opening of the firebox 200 has a diameter of about of about 28 inches. The concentric burner elements 302 A, 302 B, 302 C of the embodiment of the burner 300 have diameters of about 28 inches, 20 inches, and 13 inches, respectively. The spiral burner element 310 of another embodiment has an outer diameter of about 28 inches. The legs 512 of the base 500 are about 24 inches high and the fixed braces 516 are about 21 inches long. The hinged braces 518 are about 21 inches long and each section is about 10.5 inches long. The braces 542 A, 542 B of the tank support 540 are located about 5.625 inches from the lower fixed braces 516 D, 516 C, respectively; the hinged braces 544 A, 544 B between the fixed braces 542 A, 542 B of the tank support 540 are about 8.25 inches long and are located about 7 inches from the lower hinged braces 518 D, 518 C, respectively. The doors 502 A, 502 B and the panels 504 A, 504 B are about 21 inches high by about 23 inches wide. It will be appreciated that these dimensions are merely representative and not limiting.
[0036] The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A portable cooking unit is provided comprising a frame having an open configuration and a closed configuration. The frame comprises legs positioned in a rectangular configuration and sets of hinged and fixed horizontal braces connected between the legs at vertically spaced apart lower and upper locations. The hinged braces comprise first and second sections, both sections having an inner end and an outer end, a hinge joining the first and second sections at their respective inner ends, and pivot brackets at the outer ends connecting the first and second sections to the legs. When the frame is in the open configuration and the hinged braces are lifted at their hinges, the frame moves to the closed configuration. The cooking unit further comprises a firebox removably secured to tops of the legs of the frame when the frame is in the open configuration. | 5 |
This is a continuation of application(s) Ser. No. 07/637,013 filed on Jan. 3, 1991.
FIELD OF THE INVENTION
This invention relates generally to a communications system for carrying telemetry data and more particularly to a system that provides a ubiquitous telemetry or data network utilizing existing telephone outside plant comprising twisted pair copper without adversely impacting or otherwise affecting the plain old telephone service provided on the outside plant. Telemetry data includes site alarm conditions such as fire or unauthorized entry which are typically detected by one or more electronic surveillance devices such as smoke detectors, infrared heat detectors, sonar or infrared intrusion detectors and the like. Telemetry data also includes utility metering information produced by the water, gas or electricity meters. Telemetry data could also include other low speed data originating at the subscriber site such as control information intended to have effect at a location remote from the subscriber site.
BACKGROUND OF THE INVENTION
In the past, these devices have been connected to the public switched telephone network by obtaining a telephone line from the phone company and providing the site to be monitored with a telephone dialler device which is activated by the alarm condition signalled by the above-noted detectors. These prior art monitoring systems communicate with a central site which displays the alarm condition signalled by the monitored site and the operator of the central site contacts the site owners or appropriate civic authority (ie police, fire department etc.) to deal with the alarm condition. Such a scheme requires the installation of an additional telephone line to provide for the service to be carried without interfering with any existing telephone service which the subscriber may have.
The present invention seeks to provide an improved telemetry communications network that does not require a separate telephone line to be operated and can be operated continuously over an existing telephone line without interfering with any use of that line. That is the telemetry communications network will operate irrespective of whether a telephone call is being initiated by rotary or dual tone multi frequency (DTMF) signalling, or is being carried on, or is terminated.
SUMMARY OF THE INVENTION
In one of its aspects the invention provides a data communications system having a plurality of subscriber data interface elements each having at least one data input port and a data output port, said output port adapted to be electrically connected to a subscriber line of the telephone network to transmit data thereon without interfering with any telephone service that may be present on said subscriber line; and a network data interface element, corresponding to each subscriber data interface element, having a data input port and a data output port, said input port adapted to be electrically connected to a subscriber line of the telephone network and in communication with said subscriber data interface element thereover; and at least one data collection unit having a data storage means and a plurality of data input ports, each said data input port for connection to the data output port of a corresponding network data interface element and capable of communicating therewith for collecting and storing the data received from said network data interface elements and assembling the data into a data frame; and a data communications network for carrying the data frames produced by the data collection unit to at least one data processing facility.
In another of its aspects the invention provides a data communications system having a plurality of subscriber data interface elements each having at least one data input port and a data output port, said output port adapted to be electrically connected to a subscriber line of the telephone network to transmit data thereon without interfering with any telephone service that may be present on said subscriber line; and a network data interface element, corresponding to each subscriber data interface element, having a data input port and a data output port, said input port adapted to be electrically connected to a subscriber line of the telephone network and in communication with said subscriber data interface element thereover; and at least one data collection unit having a data storage means and a plurality of data input ports, each said data input port for connection to the data output port of a corresponding network data interface element and capable of communicating therewith for collecting and storing the data received from said network data interface elements and assembling the data into a data frame; and a data communications network for carrying the data frame produced by the data collection unit to at least one data processing facility; and a network control monitor interconnected to said data communications network to monitor traffic on said data communications network and capable of communicating with said data collection unit and said data processing facilities to set configuration parameters of same.
In yet another of its aspects, the invention provides a method of communicating telemetry data including the steps of encoding meter readings into a stream of binary coded electrical signals; periodically, at predetermined intervals, storing each meter reading and processing the meter reading to form a data frame by adding link protocol data, network protocol data and a frame check sequence; forwarding the meter reading to a data processing site.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a functional block diagram of a telemetry network in accordance with the present invention.
FIG. 2 is a functional block diagram of a subscriber data interface in accordance with the present invention.
FIG. 3 is a functional block diagram of a network data interface in accordance with the present invention.
FIG. 4 is a schematic diagram of a data frame produced by the subscriber data interface.
FIG. 5 is a detailed functional block diagram of a telemetry network in accordance with the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1, the major functional elements of the universal telemetry network are shown. The telemetry network is comprised of two major functional elements referred to as the gathering subsystem and the data network. The gathering subsystem is used by the telemetry network to collect subscriber telemetry data and relay this data to the data network which will then carry the data to processing points for final disposition. Looking in more detail at the gathering subsystem, each subscriber premises 10 is served by a telephone line 12. The telephone line 12 is a typical twisted pair of copper wires also known as a telephone pair.
Located at the subscriber premises is a telephone subscriber data interface unit 14 which is connected to the telephone line 12. The telephone subscriber data interface 14 connects to the telephone line but does not interfere with the provision of telephone service to the subscriber premises by utilizing "voice over data" communications. That is, the telephone interface unit operates at frequencies above 4 KHz to prevent interference with any telephone conversations that may be carried on the telephone line 12. Telephone subscriber data interface 14 is provided with high-pass filters which have a cut off frequency at no less than 3.5 to 4 KHz to prevent any voice signals from entering into the telephone interface unit and to prevent any significant impedance changing effects to the telephone system at the voice frequency thereby avoiding any interruption or interference with the telephone service provided on the telephone line 12.
The first point of collection in a telephone distribution network is typically a serving area concept (SAC) box which serves 400-600 subscribers. This first point of collection is the preferable location to place the remote data collection unit (RDCU) 18 as this will normally ensure that the network data interface 16 in the RDCU 18 will be within 2 kilometers of the telephone subscriber data interface 14. It is preferable to have the distance between the telephone subscriber data interface 14 and the network data interface 16 be 2 KMs or less to ensure that telephone line 12 does not have loading coils on it which would present a high impedance path to the frequencies used by the instant system. It is preferable to use a carrier frequency above the telephone audio range of 3.5 KHz to prevent tones from being heard by the subscriber when using the telephone. In the preferred embodiment, a carrier frequency in the range of 20 KHz is used; which is out of the range of hearing by an individual and signalling is accomplished by frequency shift keying (FSK).
Input to the telephone subscriber data interface 14 can be provided by several classes of devices. The first such class would be devices intended to trigger an alarm condition or other "exceptional" condition which occurs out of the ordinary. Devices of this class would include fire and intrusion alarms or conditions out side the range of acceptable limits ie. temperature too low or too high etc. A second class of devices would be state devices which signal a state that is to be monitored; such as temperature or utility metering values, ie. water meter, gas meter, power meter etc. A third class of devices would be remote control devices that would be used to control or signal a device at a remote location such as a movie request device for activation of a movie machine such as a VCR to play a movie with the pause, fast-forward, rewind, stop etc. functions available to the users of the remote control devices. As will be explained in more detail below, other devices may be connected to the subscriber data interface 14 to effect classes of signalling or control not yet envisioned.
The signalling from the subscriber data interface 14 is carried to a remote data collection unit 18 using one-way single duplex communications over existing telephone line 12. The subscriber data interface 14 produces data for transmission to the remote data collection unit periodically several times a minute. This data transmission scheme allows several repetitions of slower data, such as meter readings, to be sent to the remote data collection unit 18; thus ensuring that, out of the many redundant copies of the data forwarded to the remote data collection unit, a valid copy of the data will be forwarded to the remote data collection unit 18 even where the existing telephone line 12 is electrically noisy.
Remote data collection unit 18 forwards the data collected to one or more data processing facilities generally designated 24 over a suitable data network 22. The data network may be a simple point to point dial up network using modems and long (virtually permanent) connect times over the public switched telephone network. Preferably, the data network is a public or private X.25 packet switched network. An X.25 network is an international standard for packet switched networks and is fully defined in the CCITT (The International Telegraph and Telephone Consultative Committee) Study Group VII Blue Book published following the 9th Plenary Assembly in Melbourne, Australia, 1988 as Volume VIII--Fascicle VIII.2 which contains recommendations X.1 through X.32. Using an X.25 network for the data network 22 is preferable to provide error free data communication and to allow multiple data processing facilities 24 with a minimum of physical communications facilities. The data processing facility 24 may be a single physical system providing services for each of the users of the data collected by the network, ie. meter reading processing for natural gas, electricity, water and alarm processing for fire, burglary etc. Alternately, and preferably, the data processing facility 24 will be several physical sites as required to meet the needs of the meter reading utilities and alarm service companies.
It will be understood that the apparatus and method of data communications in accordance with the present invention is continuous in that the data signalling may be accomplished over the telephone line 12 at all times irrespective of whether a phone service is being delivered on the line or not. That is to say, the data signalling will be operable without interfering with any telephone conversation that may be carrying on over the telephone, and the data signalling will be operable without interfering with any dialling of the telephone whether by rotary pulsing or dual tone multi-frequency (DTMF) dialling, and the signalling will be operable without interfering with any ring signalling that may be present on the telephone line. As a result, "real time" processes may be controlled by use of this system. For example, FIG. 1 shows an audio/video source 20 which may be a Video Cassette Recorder (VCR) or Video disc player that could be paused or rewound by the subscriber from subscriber site 10.
A data collection network architecture in accordance with the present invention provides a network suitable for secure carriage of meter reading or alarm data to the processors of the data. The elements of data security include both the accurate transmission of the meter readings themselves and the certainty to which data can be attributed back to a specific premises and source. The data collection network achieves data integrity by transmitting data frames using a redundant bits to create a frame check mechanism such that each data frame contains information bits as well as redundant bits calculated from the information bits in accordance with a predefined algorithm. Corruption of the data frame is detected when the receiver of the data frame calculates a redundant bit pattern based on the received information bits. The calculated redundant bit pattern is then compared with the bit pattern actually received in the data frame. Any differences in redundant bit patterns indicate a transmission error. The data collection network achieves data security by providing a physical link to specific premises thus ensuring that the origin of the data is known.
Referring now to FIG. 2, which shows a functional block diagram of a subscriber data interface 14 in accordance with the present invention, it is understood that the subscriber data interface 14 transmits data from the subscriber premises into the data collection network. Each subscriber data interface is provided with a data input port 30 which enables devices to be electrically connected to the subscriber data interface 14 to input data into the network. The data to be transmitted is shown, by way of example, to be meter information from gas, water and power meters, through meter input interface lines designated generally as line group 32. The data input port 30 also provides a general purpose interface line (GPIO) 34 which can be used to provide data input from any other manner of device sought to be connected to the network. The meter reading data is read periodically (ie. is polled) by microprocessor 36 which selects the meter input interface line (ie. one line in the group 32) and obtains the data from the selected meter and converts the selected data to a data frame form for transmission. Alternately, data may be presented on the general purpose interface (GPIO) line 34 and the microprocessor (CPU) 36 will read the data from the GPIO line 34 and transmit it as soon as practicable. The real time transmission of the GPIO data is accomplished by one of two methods: the microprocessor 36 can be interrupted when data is present on GPIO line 34, or the microprocessor 36 can check the GPIO line very frequently (ie 5-10 times per second) and frame and transmit any data that is presented on the GPIO line 34. The format of the data frame will be explained in more detail subsequently with reference to FIG. 4. The data frame is then modulated using frequency shift keying (FSK) by FSK modulator 38. The so modulated signal is injected onto existing telephone line 12 through data output port 40 which is essentially a high pass filter that presents a very high impedance to signals in the voice band (ie less than 3-4 KHz) so as not to interfere with conventional use of the telephone. Data output port 40 is provided with a balanced output amplifier to amplify the data signal to permit it to travel the required distances over telephone line 12. A balanced output is used to prevent crosstalk of the signalling to other telephone lines in the cable bundle serving other subscribers in the area. Preferably the data output port capacitively couples to the telephone line 12 using 100 nanofarad capacitors which enable good coupling of the data signal in the 20-30 KHz range and good filtering of the voice band signals which may be present on telephone line 12. The above described subscriber data interface 14 is preferably connected to the telephone line 12 in the subscriber premises after the lightening protection block (not shown) which eliminates the need to have lightening protection in the subscriber data interface 14 thereby reducing the expenses of the device.
FIG. 3 is a functional block diagram of a network data interface in accordance with the present invention. The network data interface is electrically connected to the telephone line 12 at a convenient access point in the outside plant of the telephone network, preferably within 2 kilometers of the subscriber. This access is conveniently provided in telephone access networks at the telephone serving area concept cross connect facility (SAC box). In an urban environment the telephone SAC box will typically be located within 2 KMs of the subscriber. Each telephone SAC box serves in the neighbourhood of 600 subscribers. Located proximate to the telephone SAC box is the remote data collection unit RDCU 18 shown in FIG. 1. Each subscriber line 12 is bridged to a network data interface element 16 using signal coupling capacitors 42 as explained with reference to the subscriber data interface 14 with reference to FIG. 2. Since no lightening protection is provided at the SAC box, it is preferable to isolate the network data interface element 16 from voltage transients on subscriber line 12 using lightening protectors 44. Any suitable lightening protector typical of that used in the telephone industry is acceptable and well known to those skilled in the art. The signal induced in the network data interface element 16 is next high pass filtered by high pass filter 46 As with the subscriber data interface 14, the data input port of the network data interface capacitively couples to the telephone line 12 using 100 nanofarad capacitors which enable good coupling of the data signal in the 20-30 KHz range and good filtering of the voice band signals which may be present on telephone line 12. The data input port may further be provided with a low pass filter 47 having a cut off frequency of about 35 KHz (or any suitable cut off frequency above the data carrier frequency) which eliminates any high frequency noise from entering the demodulator FSK demodulator 48. FSK demodulator 48 is preferably provided with 2 outputs. The first is data line 50 where the data frames received over telephone line 12 and demodulated by demodulator 48 are output for further processing as described below with reference to FIG. 5. The second output is control line 52 which signals the presence of the data carrier on telephone line 12. The control line allows continuous monitoring of the operation of the FSK modulator 38 in subscriber data interface 14 by looking for the carrier signal and providing a signal on the control line 52 indicating the presence or absence of the carrier signal on telephone line 12. The signal on the control line could be a TTL logic level of say 0 volts for no carrier and +5 volts for carrier present. This carrier detection allows the RDCU to raise an alarm condition if the carrier disappears on a telephone line 12 which would be useful where the subscriber has burglar alarms that must be continuously verified to make sure the subscriber line 12 has not been tampered with.
FIG. 4 is a schematic diagram of a data frame produced by the subscriber data interface. The data frame contains 4 elements of information. At the start of each data frame is a Link Protocol Data Unit (LPDU), followed by a Network Protocol Data Unit (NPDU), followed by the Information data unit of variable size, all followed by a Frame Check Sequence. The LPDU can be one byte (8 bits) long with a predefined flag and frame sequence contained therein. The frame sequence number could take up 4 bits of the byte providing a modulo 16 frame sequence number which would be incremented each time a data frame is sent. The receiving station could use the data frame sequence number to monitor link quality by being able to determine how many data frames are being lost. The NPDU can be one byte (8 bits) long having 4 bits to specify the originating port in the subscriber interface unit 14, for example, "0000" for port 0--the water meter, "0001" for port 1--the gas meter, "0010" for port 2--the electric meter, "0011" for port 4--the GPIO port, "1111" for a supervisory message etc. The remaining 4 bits of the NPDU could then be used to specify the length of the IDU in bytes, ie. a range of 0-15 bytes in length. The IDU would contain any information to be transmitted by the meters or devices attached to the subscriber data interface 14, ie data messages containing meter readings or alarm conditions, etc. or supervisory messages relaying information on the status condition of the subscriber data interface unit 14 itself: ie "01010101"--I'm doing just fine, "10000000"--can't read port 0, "10000001"--can't read port 1 etc. The FCS portion of the data frame would be extra bits calculated from the preceding bits in the data frame. For example, the FCS could be a simple parity bit, or a parity byte. The FCS thus can be recalculated at the receiving station and compared to the FCS actually received to give an independent check on whether the data frame was corrupted in transmission.
Referring now to FIG. 5 which shows a detailed functional block diagram of a telemetry network in accordance with the present invention. Each of the subscriber data interface units 14 is connected to a corresponding remote data collection unit 18 via existing subscriber telephone line 12. Data from the RDCU 18 is communicated to the data network 22 using a data network interface 26. The data network interface 26 is preferably an X.25 packet assembler disassembler which works very closely with the network control monitor 28. The data network interface 26 converts the data frames into addressed data packets in accordance with the X.25 standard and moves the data frames from the RDCU 18 into the data network 22 and is responsible for detecting the presence or absence of carrier on the network data interface element 16. When carrier is detected, the data network interface 26 could be configured to establish a virtual channel over the data network 22 to one or more of the data processing facilities 24 to allow data to be forwarded to the appropriate data processing facility for processing (ie. electric meter data carried over a virtual circuit to the "Electrical" data processing facility, alarm data carried over a virtual circuit to the "Alarm" data processing facility. A loss of carrier indicated by the network data interface element 16 may cause the data network interface 26 to tear down the virtual circuits and log it for action by the network control monitor 28. The RDCU 18 is provided with storage means capable of storing the data frames received for each subscriber connected to it. The RDCU 18 is capable of receiving instructions from network control monitor 28 to process the data frames received by each network data interface element 16 to forward all data frames as received or forward only data frames that changed from the previous data frame (ie a water meter reading arriving at the RDCU 18 ever 15 minutes might only be given to the data network interface 26 for framing and delivery when a new meter reading arrived) or forward data only when requested from the appropriate data processing facility 24 (ie. forward water meter readings only on request by the "Water" data processing facility). Thus the RDCU 18 is provided with a remotely programmable data filter process which decreases the amount of data loaded onto the data network 22 as controlled by the network control monitor 28 or as controlled by the appropriate data processing facility 24. The data network interface 26 is responsible for appending address information to each data packet (as described with reference to FIG. 4) which will route the packet to the proper data processing facility 24 and will indicate to that facility where the packet originated from.
The network control monitor 28 is responsible for logging and accessing statistics on the data network 22 performance and errors; and reporting and logging network alarm conditions (ie RDCU 18 or data network interface 26 stoppages due to cut lines etc.); and maintaining a data structure containing the configuration database for the data network 22 to allow configuration updates to be sent to the appropriate RDCU 18 and data network interface 26 and data processing network interface 54. The network control monitor 28 is also provided with a debug facility to allow supervisory communications with any data processing facility 24 or RDCU 26 to make status inquiries and corrective updates as well as monitor data packet contents and traffic on data network 22 to maintain operation of the network.
Each data processing facility 24 is provided with a data processing network interface 54 which sends and receives data packets from the data network 22 that are needed for processing at the facility. The data processing facility 24 is provided with storage means for maintaining a data structure equating the data network address of each subscriber with the customer billing data maintained by the utility provider so that usage billing may be produced. Also each data processing facility 24 is given the ability to introduce data packets into the data network 22 to allow the facility to query the RDCU 18 for the current meter reading of a particular subscriber 10 (see FIG. 1).
Now that the invention has been disclosed and illustrative embodiments have been described herein with reference to the accompanying drawings, the present invention is not limited to these particular embodiments. Various changes and modifications may be made thereto by persons skilled in the art without departing from the spirit or scope of the invention, which is defined by the appended claims. | A data communications system which comprises at least one group of subscriber data interface elements, with each interface element having at least one data input port and a data output port, and each output port being electrically connectable to a subscriber line of the telephone network to transmit data thereon without interfering with any telephone service that may be present on these subscriber line. A network data interface element, for each group of subscriber data interface elements, being located within a short distance from the farthest subscriber data interface element. Each subscriber data interface element having a data input port and a data output port, and each input port being electrically connectable to a subscriber line of the telephone network and in communication with these subscriber data interface elements thereover. A data collection unit having a data storage mechanism and a plurality of data input ports, with each data input port being connectable to the data output port of a corresponding network data interface element and capable of communicating therewith for collecting and storing the data received from these network data interface elements and assembling the data into a data frame. A data communications network for carrying the data frames produced by the data collection unit to at least one data processing facility. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The priority benefit of U.S. Provisional Patent Application No. 61/608,985, filed Mar. 9, 2012, is hereby claimed and the entire contents thereof are incorporated herein.
FIELD OF THE DISCLOSURE
[0002] The present disclosure is directed to a system for tuning the acoustic envelope of a designated space and, more particularly, to a dynamic system for tuning the acoustic envelope within a designated space.
BACKGROUND
[0003] Within the field of contemporary acoustic design, numerous products and systems have been developed that may be added to the interior of an existing space to modify the sound reflecting and sound absorbing characteristics of that space. Evidence of this work is ubiquitous and typically involves reflector panels, variable absorption curtains, and/or electro-acoustic systems often operating in tandem to produce the desired acoustic outcomes. Dynamic “sound clouds” offer a computationally-controlled set of sound reflecting surfaces that can be digitally actuated in response to changing acoustic demands by virtue of variations in their physical deployment and orientation.
[0004] “Responsive Envelopes” constitute an area of architectural research that pursues the design of multi-functional surfaces that adjust their formal configuration in response to varying environmental conditions in order to transform the envelope's impact upon its environment. While there have been few efforts to synthesize variable acoustic response into single geometric surface-based systems capable of producing modifications in aural characteristics, there has not been the development of a composite envelope-based system that possesses the capacity for predictive volumetric and surficial performance variation based on the alteration of its surface and/or volumetric characteristics while simultaneously configuring electro-acoustic amplification within the system.
SUMMARY
[0005] One aspect of the present disclosure provides a system including an acoustic shell, a plurality of hinges, a plurality of surficial actuators, and a control system. The acoustic shell comprises a plurality of panels arranged in a tessellated pattern relative to one another, the plurality of panels including at least one sound reflecting panel and at least one sound absorbing panel. The at least one sound reflecting panel has an exposed surface a majority of which comprises a sound reflecting surface. The at least one sound absorbing panel has an exposed surface a majority of which comprises a sound absorbing surface. The plurality of hinges connect edges of at least some of the panels to edges of immediately adjacent panels such that each panel is movably connected to at least one other panel. Each of plurality of surficial actuators is connected between at least two of the plurality of panels for moving the two panels relative to each other such that the plurality of surficial actuators can manipulate the plurality of panels to change the overall sound reflecting and sound absorbing properties of the acoustic shell. The controller is for at least controlling the surficial actuators.
[0006] Another aspect of the present disclosure provides a venue comprising a housing, an acoustic shell, a plurality of hinges, a plurality of surficial actuators, and a control system. The housing defines a space having ambient properties. The acoustic shell is suspended within the space of the housing, and includes a plurality of panels arranged in a tessellated pattern relative to one another. The plurality of panels include at least one sound reflecting panel and at least one sound absorbing panel. The at least one sound reflecting panel has an exposed surface a majority of which comprises a sound reflecting surface. The at least one sound absorbing panel has an exposed surface a majority of which comprises a sound absorbing surface. The plurality of hinges connect edges of at least some of the panels to edges of immediately adjacent panels such that each panel is movably connected to at least one other panel. Each of the plurality of surficial actuators is connected between at least two of the plurality of panels for moving the two panels relative to each other such that the plurality of surficial actuators can manipulate the plurality of panels to change the overall sound reflecting and sound absorbing properties of the acoustic shell. The controller is for at least controlling the surficial actuators.
[0007] Another aspect of the present disclosure provides a method of controlling the acoustics of a space. The method includes determining a set of desired acoustic characteristics for a space. The method additionally includes determining a desired sound absorbing property of a tessellated acoustic shell that is suspended within the space, the tessellated acoustic shell comprising a plurality of panels, the plurality of panels including at least one sound reflecting panel and at least one sound absorbing panel, the at least one sound reflecting panel having an exposed surface a majority of which comprises a sound reflecting surface, the at least one sound absorbing panel having an exposed surface a majority of which comprises a sound absorbing surface. The method further includes determining a desired sound reflecting property of the tessellated acoustic shell. Still further, the method includes adjusting actual sound absorbing and sound reflecting properties of the tessellated acoustic shell toward the desired sound absorbing and reflecting properties by moving at least one of the plurality of panels of the tessellated acoustic shell relative to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of one example of a system constructed in accordance with the principles of the present disclosure;
[0009] FIG. 2 is a perspective view and partial exploded perspective view of an acoustic shell of the system of FIG. 1 ;
[0010] FIG. 3 is a partial perspective view an partial exploded view of the acoustic shell of FIGS. 1 and 2 ;
[0011] FIG. 4 is a schematic diagram of one example of a control system for an acoustic system constructed in accordance with the principles of the present disclosure;
[0012] FIG. 5 is a schematic diagram of another example of a control system for an acoustic system constructed in accordance with the principles of the present disclosure;
[0013] FIG. 6 is a schematic representation of an origami pattern utilized in the system of FIGS. 1 to 3 ;
[0014] FIGS. 7A-7C are sectional perspective views of another example of a system constructed in accordance with the principles of the present disclosure;
[0015] FIG. 8 is a schematic representation of an alternative origami pattern for use in accordance with the principles of the present disclosure; and
[0016] FIG. 9 is a schematic representation of another alternative origami pattern for use in accordance with the principles of the present disclosure.
GENERAL DESCRIPTION
[0017] The present disclosure is directed to a dynamic responsive acoustic tuning envelope system that, in one example, includes a continuous composite membrane-connected set of cells, each possessing sound reflecting, sound absorbing, or electro-acoustic properties that are assembled according to the principles of rigid origami. So configured, the system is capable of both localized surficial deformation to alter the percentage material surface exposure, transform its textural profile, and alter the enclosed volume of space in a single material envelope. The panelized system is unified by its connection to the continuous composite flexible membrane, to which leading edge exposed surfaces and framed backpanels are affixed. The connection to the membrane can be achieved by way of adhesive or by way of mechanical fixtures such as clamps or other devices. One example of the system could include the following types of panels: (i) solid sound reflecting panels including a total material thickness of 1¼″ and possessing a material density of 2.5 psf, (ii) sound absorbing panels consisting of a ¼″ thick face panel perforated to provide a minimum of 25% exposure to, and backed with 2″ of porous extruded polypropylene milled to meet the geometric requirements of the overall system limitations in extreme conditions of flat-folding, and, optionally, (iii) electro-acoustic panels consisting of an internally milled 3/16″ resonating panel equipped with a piezoelectric acoustic transducer. In this way, the panel becomes a Distributed Mode Loudspeaker (DML), in which sound is produced by inducing uniformly distributed vibration modes in the panel through a special electro-acoustic exciter. DMLs function differently than most other speakers, which typically produce sound by inducing pistonic motion in the diaphragm. Exciters for DMLs include, but are not limited to, moving coil and piezoelectric devices, and are placed to correspond to the natural resonant model of the panel.
[0018] The specific geometric configuration and percentage of each panel within the total envelope design of the present disclosure are determinate of desired overall system performance of a specific space. Localized deformation of the system surface geometry can be achieved via a number of linear actuators—determined by the degrees of freedom of the geometric configuration, mounted to the reverse surface (e.g., back side) of the sound absorbing panel (or other panel) assemblies and causes localized contraction (and expansion) of the corresponding facial exposure of each panel. By virtue of rigid origami structures, these actions are conveyed to other locations within the envelope through a determinate number of degrees of freedom. In addition to this localized surficial deformation, gross deformation to alter the overall acoustic volume enclosed by the system can be achieved through triangulated cable-stayed suspension linked to a frame mounted stepper motor array above, or through any other suitable device. Actuation controls and system signals can be sent to the envelope wirelessly through a control system capable of utilization towards a variety of performance goals.
[0019] Potential applications of the system range from large scale field deployment in the design of musical performance venues with multiple performance types (e.g., musical content and audience configuration), flexible entertainment venues with varying spatial and performance demand (e.g., convention centers, auditoria, etc.), specialized venues for multimedia presentations (e.g., boardrooms, meeting rooms, etc.), lecture halls, gymnasiums, classrooms, work spaces that benefit from environmental acoustic control, highly specialized experimental music performance venues where multichannel playback through electro-acoustic panels can be paired with dynamic real-time actuation of the system, and virtually an unlimited number of other types of similar venues and spaces. The system may also be capable of responding to occupancy (e.g., the presence or the lack of presence of individuals in the space) and noise levels through material exposure (e.g., in educational spaces, galleries, restaurants, etc.).
DETAILED DESCRIPTION
[0020] Turning now to the figures, various representative examples of systems and methods in accordance with the principles of the present disclosure will be described.
[0021] FIG. 1 depicts one example of a system 10 based on the principles of the present disclosure that includes one (1) to three (3) acoustic shells 100 a , 100 b , 100 c suspended from a ceiling 102 of a space 104 (e.g., auditorium, gymnasium, lobby, concert venue, classroom, etc.). The acoustic shells 100 a , 100 b , 100 c depicted in FIG. 1 are essentially identical in construction, and therefore, the reference numeral 100 will be used generically to refer to any one of the shells 100 a - 100 c . Each shell 100 includes a plurality of panels 106 arranged in a tessellated pattern and pivotally connected to each other such as to allow localized surficial deformation of the acoustic shell 100 . The plurality of panels 106 of the example depicted in FIG. 1 include sound reflecting panels 106 a and sound absorbing panels 106 b . Additionally, in this example, one of the shells includes at least one electronics panel 106 c as part of a control system, as will be described. The electronics panel 106 c may or may not possess a sound reflecting or sound absorbing property. In the depicted example, the panels 106 are configured in accordance with the geometric properties of rigid origami utilizing two different sizes of triangles. More specifically, the sound reflecting panels 106 a include triangles of a first size, while the sound absorbing panels 106 b include triangles of a second size that is smaller than the first size. This is merely one example, however, and other sizes and shapes of panels can be used, as will be discussed more below. Additionally, as can be seen, the sound absorbing panels 106 b of this example are arranged in clusters 107 (one of which is highlighted in FIG. 1 with a darkened perimeter line) that themselves define larger triangles.
[0022] So configured, and as can be seen in FIG. 1 , the foremost and middle acoustic shells 100 a , 100 b are depicted in partially opened/partially closed configurations, whereby the sound reflecting panels 106 a are completely exposed to the space and the sound absorbing panels 106 b are partially exposed to the space. Said another way, the sound absorbing panels 106 b are partially folded such that each cluster 107 defines a variable interior volume of space in the form of a recess in the shell 100 . By comparison, the rear-most acoustic shell 100 c is depicted in a fully opened flat configuration, whereby the sound reflecting panels 106 a and the sound absorbing panels 106 b are completely exposed to the space and occupy a common flat plane. The foremost and middle shells 100 a , 100 b depicted in FIG. 1 therefore possess distinctly different sound reflecting and absorbing properties than the rear-most acoustic shell 100 c because the orientation of exposed sound sound reflecting panels 106 a and exposed sound absorbing panels 106 b is different. Moreover, the angular orientation of the sound absorbing panels 106 b and the magnitude of the internal volumes defined by the clusters 107 impact the way that sound is reflected and absorbed by each of the shells 100 a , 100 b , 100 c.
[0023] As mentioned, each shell 100 is capable of localized surficial deformation such that in FIG. 1 , for example, any of the shells 100 a , 100 b , 100 c can be expanded to occupy the opened configuration such that is by the rear-most shell 100 c , or can be contracted to occupy a closed configuration, whereby the sound absorbing panels 106 b are collapsed upon each other in a manner that the only exposed surfaces of the shell 100 include those of the sound reflecting panels 100 a . In such a configuration, the clusters 107 of sound absorbing panels 106 b are essentially closed upon themselves such that the previously existent recesses are of zero volume. To achieve this local deformation, the shells 100 are equipped with a plurality of mechanical actuators (not seen in FIG. 1 ).
[0024] FIG. 2 depicts one of the shells 100 of FIG. 1 from a top side 108 (i.e., the side facing the ceiling 102 in FIG. 1 ). FIG. 2 additionally includes an exploded perspective view of each of the various panels 106 of the shell 100 .
[0025] As mentioned above, the individual panels 106 of the shell 100 are pivotally connected to each other such as to allow for localized surficial deformation. In one example, the panels 106 have chamfered side edges to provide for the necessary free range of motion and are connected to each other by way of mechanical or chemical means of mating adjacent elements across the system so as to produce continuity of the membrane and flexural hinge system. In one example, the flexible membrane can include a rubber or other synthetic material adhered to a front side of supporting frames of the panels 106 , as will be described, via an adhesive such as 3M™ VHB™ Tape or mechanical clamping detail mating face plate to frame element and integral membrane. So configured, the flexible membrane can serve as a flexural hinge between the panels 106 . Preferably, the flexible membrane can be cut to include openings and appropriate geometries not to interfere with the acoustic properties of the panels 106 themselves. In other examples, the shell 100 does not use a flexible membrane for the hinge, but rather another type of hinge such as a barrel hinge or other mechanical coupler enabling the desired range of movement could be used. In yet another example, the hinge could be provided for by a piece or sheet of shape memory alloy, for example, creating a foldable joint between adjacent panels 106 . The shape memory alloy may then be manipulated between an at least partially folded state and a flat state depending on the magnitude of an electric charge applied to the alloy to move (e.g., pivot) the panels 106 relative to each other.
[0026] As shown in FIG. 2 , the top side 108 of each shell 100 includes a plurality of actuators 110 arranged for imparting localized surficial deformation of the shell 100 . In the present example, each actuator 110 attaches between two adjacent sound absorbing panels 106 b generally perpendicular to the joint between the panels 106 b . This allows for the localized contraction and expansion of the sound absorbing panels 106 b , the movement of which naturally results in movement of the sound reflecting panels 106 a to accomplish the various configurations of the shell 100 as discussed above with reference to FIG. 1 . In one example, the actuators 110 include linear actuators that are electrically driven, magnetically driven, or otherwise suitable for the intended purpose. Other types of actuators can also be used. While the actuators 110 are described in this example as being connected to the sound absorbing panels 106 b , the other examples could alternatively or additionally include the actuators 110 connected to the sound reflecting panels 106 a depending of the origami pattern utilized and the desired functional objectives.
[0027] Still referring to FIG. 2 , the upper portion illustrates exploded views of the sound reflecting panels 106 a , the sound absorbing panels 106 b , and the electronics panel 106 c of the shell 100 . Additionally, as will be described below, FIG. 2 depicts an exploded view of an optional electro-acoustic panel 106 d , one or more of which could be included in the shell 100 . As can be seen, each of the panels 106 comprises a composite structure.
[0028] The sound reflecting panels 106 a include an exposed surface layer 112 , a backing frame 114 , a solid infill panel 116 , and a backing layer 118 . In FIG. 2 , the exploded view of the sound reflecting panel 106 a is also depicted as including a portion 115 of the aforementioned flexible membrane disposed between the exposed surface layer 112 and the backing frame 114 . Although the membrane 115 is illustrated as being cut to the size of the panel 106 a , this is only for the sake of illustration to show the sandwiched positional relationship of the membrane relative to the other components of the panel 106 a . In practice, the portion 115 constitutes a segment, which is aggregated with other similar portions through the incorporation of adhesive seams, for example, to form a continuous sheet of the flexible membrane, which also forms part of the composite structure of the other panels 106 of the shell 100 , as will be described.
[0029] With continued reference to FIG. 2 , the solid infill panel 116 is disposed within the backing frame 114 and may be in contact with or in close proximity to the exposed surface layer 112 across a majority of the area of the exposed surface layer 112 . The backing layer 118 assists in holding the solid infill panel 116 in position. In one example, the exposed surface layer 112 , backing frame 114 , and backing layer 118 can be constructed of wood, bamboo, aluminum, plastic, or any other suitable material and can be secured together with any suitable fastener (e.g., a mechanical fastener, an adhesive fastener, or otherwise). The solid infill panel 116 can be constructed of any one of a variety of materials having a combination of material characteristics and dimensional thickness constituting an overall material density of 2.5 psf. In one example, the solid infill panel 116 can be a 1 and ¼″ thick piece of bamboo plywood, but other materials having different thicknesses can be used to achieve the desired objective.
[0030] Still referring to FIG. 2 and in combination with FIG. 3 , the sound absorbing panels 106 b of the shell 100 include a perforated surface layer 120 , a backing frame 122 , a sound absorbing fill panel 124 , and a backing layer 126 . In FIG. 2 , the exploded view of the sound absorbing panel 106 b is also depicted as including a portion 125 of the aforementioned flexible membrane disposed between the perforated surface layer 120 and the backing frame 122 . Similar to that described above with respect to the sound reflecting panels 106 a , although the portion 125 of the membrane is illustrated as being cut to the size of the sound absorbing panel 106 b , this is only for the sake of illustration to show the sandwiched positional relationship of the membrane relative to the other components. In practice, the portion 125 constitutes a segment, which is aggregated with other segments by way of adhesive seams, for example, to form a continuous sheet of the flexible membrane that also includes portion 115 . As such, the membrane connects the sound reflecting and absorbing panels 106 a , 106 b together, as discussed above.
[0031] With continued reference to FIG. 2 and with reference to FIG. 3 , the perforated surface layer 120 of the sound absorbing panel 106 b is bonded to the backing frame 122 with the portion 125 of the flexible membrane (shown in FIG. 2 ) sandwiched therebetween. The sound absorbing fill panel 124 is formed such as to fit within the backing frame 122 and have a surface that lies in contact with or in close proximity to the perforated surface layer 120 . As shown in FIG. 2 , the sound absorbing fill panel 124 also defines a recess 128 , in which the backing layer 126 is received and affixed. The backing layer 126 provides a solid panel for securing to the actuators 110 , as shown in FIG. 3 , for example. In one example, the perforated surface layer 120 , the backing frame 122 , and backing layer 126 can be constructed of wood, bamboo, aluminum, plastic, or any other suitable material. The sound absorbing fill panel 124 can be constructed of a porous expanded polypropylene material or some other material having suitable acoustic absorption properties.
[0032] As mentioned, the sound reflecting and absorbing panels 106 a , 106 b of the present application include sound reflecting and absorbing characteristics. The sound reflecting and absorbing characteristics of the sound reflecting and absorbing panels 106 a , 106 b , respectively, can both be expressed in terms of sound absorption coefficients. Table 1, set forth immediately below, provides sound absorption coefficients across a range of frequencies for each of the panels 106 a , 106 b of one example of the system of the present disclosure.
[0000]
TABLE 1
—
Frequency (Hz)
—
125
250
500
1k
2k
4k
Sound Absorbing
5-10
15-25
75-85
80-90
85-95
80-90
Material-Absorption
Coefficients (×10 −2 )
Sound Reflecting Panel-
Absorption
10
15
10
5
5
5
Coefficients (×10 −2 )
[0033] Referring back to FIG. 2 , the electronics panel 106 c for the shell 100 of the present example is similar to the sound reflecting panels 106 a in that it includes an exposed surface layer 128 , a backing frame 130 , and a backing layer 132 . Also, like the sound reflecting and absorbing panels 106 a , 106 b discussed above, the electronics panel 106 c includes a portion 135 of the aforementioned flexible membrane disposed between the exposed surface layer 128 and the backing frame 130 . Although the membrane 135 is illustrated as being cut to the size of the panel 106 c , this is only for the sake of illustration to show the sandwiched positional relationship of the membrane relative to the other components of the panel 106 c . In practice, the portion 135 constitutes a segment, which is aggregated with other segments by way of adhesive seams, for example, to form a continuous sheet of the flexible membrane, which also includes the portions 115 , 125 of the sound reflecting and absorbing panels 106 a , 106 b . Finally, as shown, the electronics panel 106 c includes an electronics set 134 that constitutes a portion of the control system for controlling the localized surficial deformation of the shell 100 including controlling the actuation of the actuators 110 . The individual components of the electronics set 134 will be described more fully below, and the exposed surface layer 128 , backing frame 130 , and backing layer 132 essentially serve to accommodate the storage of the electronics set 134 . That is, the backing frame 130 is bonded to and sandwiched between the exposed surface later 128 and backing layer 132 such that a cavity is formed for containing the electronics set 134 .
[0034] Finally, as mentioned, the shell 100 of the present example may optionally include one or more electro-acoustic panels 106 d . The electro-acoustic panel 106 d is constructed generally identical to the electronics panel 106 c , in that it includes an exposed surface layer 136 , a backing frame 138 , a backing layer 140 , and a portion 145 of the flexible membrane. However, instead of including the electronics set 134 , the electro-acoustic panel 106 d includes an acoustic transducer 142 (also depicted in FIG. 3 ) that turns the electro-acoustic panel into a Distributed Mode Loudspeaker (DML). The acoustic transducer 142 is mounted to the backing layer 140 (as shown in FIG. 3 ) of the electro-acoustic panel 106 d to produce the desired functionality.
[0035] As discussed above, the sound absorbing panels 106 b of the present example are movable (e.g., pivotable) relative to one another and relative to the sound reflecting panels 106 a by way of the actuators 110 to change, alter, and adjust the acoustic properties of the shell 100 . Moreover, in examples that include one or more electro-acoustic panels 106 d , those panels 106 d become acoustic generators that can further influence acoustic properties of the shell 100 and any space in which the shell 100 is suspended.
[0036] To achieve the desired controls, any system 10 of the present application can be equipped with a control system 200 such as that depicted in FIG. 4 . The control system 200 includes a programmed logic controller (PLC) 202 , a logic transmitter 204 , an optional audio transmitter 206 (for shells 100 that include electro-acoustic panels 106 d ), the electronics set 134 carried by the electronics panel 106 c described above, the actuators 110 , and one or more optional acoustic transducer 142 (for shells 100 that include electro-acoustic panels 106 d ), each carried by one or more optional electro-acoustic panels 106 d . The electronics set 134 carried by the electronics panel 106 c includes a controller 208 , a power supply 210 , and an optional amplifier 212 (for shells 100 that include electro-acoustic panels 106 d ). The PLC 202 can be a personal computer for example. The logic transmitter 204 can be a wireless transmitter in data communication with the controller 208 , which in turn, is in data communication with the actuators 110 either via wires or wirelessly. In one example, the logic transmitter can include an XBee wireless transmitter and the controller 208 can include an Arduino FIO controller. In examples that include electro-acoustic panels 106 d , the audio transmitter 206 communicates wirelessly with the amplifier 212 , which in turn, communicates either via wires or wirelessly with the DMLs. The power supply 210 on the electro-acoustic panel 106 d provides power to the electronics set 134 and to the actuators 110 and acoustic transducers 142 , if necessary.
[0037] So configured, in order to adjust the configuration of the panels 106 of the shell 100 , the PLC 202 sends instructions to the on-board controller 208 via the logic transmitter 204 , for actuating any one or more of the actuators 110 to arrive at the desired configuration of the shell 100 . Additionally, in examples that include the electro-acoustic panels 106 d , the PLC 202 sends audio signals to the on-board amplifier 212 via the audio transmitter 206 . The on-board amplifier 212 then amplifies the audio signal and supplies it to the desired acoustic transducers 142 , which then function to resonate their respective panels and create the desired audio output. The aforementioned logic for controlling the actuators 110 may be logic that is pre-programmed in the PLC 202 to achieve a desired acoustical result based on some pre-determined parameters. For example, if the shell 100 is included within a concert hall that is hosting a rock concert, the PLC 202 might be manually instructed (e.g., by a sound engineer) to apply a first set of logic to actuate the actuators 110 and configure the shell 100 in a first configuration. However, if subsequently, the same concert hall was hosting the concert of a classical pianist, the PLC 202 might be manually instructed (e.g., by a sound engineer) to apply a second set of logic to actuate the actuators 110 and configure the shell 100 in a second configuration that is distinct from the first.
[0038] Alternatively, the shell 100 could be equipped with a more sophisticated control system 300 (e.g., shown in FIG. 5 ) for controlling the configuration of the shell 100 based on real-time changes in the acoustical environment in which the shell 100 resides. More specifically, the shell 100 could include a control system 300 that is capable of changing the configuration of the shell 100 based on one or more determinations made as a function of the ambient properties of the environment. For example, as depicted in FIG. 5 , such a control system 300 could include a programmed logic controller (PLC) 302 , a logic transmitter 304 , the electronics set 134 carried by the electronics panel 106 c described above, the actuators 110 , and one or more optional acoustic transducers 142 (for shells 100 that include electro-acoustic panels 106 d ), each carried by one or more optional electro-acoustic panels 106 d , and any one or more of a plurality of sensors 306 . The electronics set 134 carried by the electronics panel 106 c includes a controller 308 , a power supply 310 , and one or more optional amplifiers 312 (for shells 100 that include electro-acoustic panels 106 d ).
[0039] The PLC 302 can be a personal computer, for example. The logic transmitter 304 can be a wireless transmitter in communication with the personal computer and in data communication with the controller 308 , which in turn, is in data communication with the actuators 110 either via wires or wirelessly. In one example, the logic transmitter 304 can include a wireless transmitter and the controller 308 can include a wireless receiver, each operating in accordance with the Narada multicast protocol. The one or more sensors 306 can include at least one of an acoustic pressure sensor for sensing sound in the space, an infrared projector for irradiating infrared light waves into the space, a digital camera for sensing profiles of reflective light in the space, a temperature sensor for detecting temperatures or temperature profiles in the space, and/or any other suitable type of sensor capable of obtaining information suitable for the intended purpose. In one example, the one or more sensors 306 utilizes a combination of infrared and camera-based technologies such as that implemented in the Kinect™ technology to sense the occupancy and/or movement of individuals in the space around and/or below the shell 100 . In examples that include electro-acoustic panels 106 d , the logic transmitter 304 can also communicate wirelessly with the amplifiers 312 , through the logic receiver 308 . The amplifiers 312 thereby, in turn, communicate either via wires or wirelessly with the acoustic transducers 142 . The power supply 310 on the electro-acoustic panel 106 d provides power to the electronics set 134 and to the actuators 110 and acoustic transducers 142 , if necessary.
[0040] With this alternative control system 300 , the system 10 of the present disclosure can be capable of detecting in real-time the ambient properties of the space and adjusting the configuration of the one or more shells 100 to have a desired acoustic effect. For example, through the use of acoustic pressure sensors, the control system 300 can determine that a room has too much or too little reverberation and it can adjust the configuration of one or more shells 100 that are suspended in the space accordingly. Furthermore, through the use of Kinect™ technology, the control system 300 can determine where in a room a crowd of people may or may not be gathered, and thereby the system 300 can adjust the configuration of one or more shells 100 that are suspended in the space to achieve a desired acoustic effect.
[0041] As illustrated in FIGS. 1 and 2 , each shell 100 of the system 10 thus far described has a finite number of panels 106 . For example, in FIG. 2 , the shell 100 includes fifty-four (54) total panels including 42 sound absorbing panels 106 b , one (1) electronics panel 106 c , and the remaining eleven (11) panels 106 can all be sound reflecting panels 106 a , or one or more of them may optionally include electro-acoustic panels 106 d . This shell 100 , however, is merely one example of a system 10 constructed in accordance with the present disclosure. In fact, due to the repeatability of the rigid origami construct employed, the number of panels 106 in any given shell 100 can be limitless. This is exhibited by the schematic illustration depicted in FIG. 6 , as well as FIGS. 7A , 7 B, and 7 C.
[0042] The dark outlined central portion of the tessellated pattern shown in FIG. 6 constitutes an area equal to the number of panels of the shell 100 described above, but any shell 100 can be expanded to include any number of panels 106 , as illustrated. Thus, the size and range of configurations of any shell 100 constructed in accordance with the present disclosure is limitless. Moreover, while in FIG. 1 , each of the panels 106 are depicted as being easily distinguishable with the human eye, advances in micro-control technology could allow for the panels 106 to be reduced in size such that entirety of the shell 100 appears to be a single continuous fluid-like body with pivoting joints that could only be detected upon close inspection.
[0043] With this understanding, FIGS. 7A-7C depict another embodiment of a system 1000 including a shell 1100 suspended from a ceiling 1002 of a space (e.g., a concert hall) by way of a suspension system 1200 . The shell 1100 can be constructed in accordance with the teachings for the shells 100 described above, with the only difference being the number of panels 106 . However, instead of having multiple shells 100 occupying a common space, as depicted in FIG. 1 , the system 1000 of FIGS. 7A-7C includes a single shell 1100 of much larger gross dimensions. As shown, the suspension system 1200 can include a series of vertical suspension members 1204 for hanging the shell 1100 , as well as one or more gross displacement actuators 1206 for adjusting the position of different portions of the shell 1100 relative to the ceiling 1002 . The suspension members 1204 might include cables, wires, rack and pinion structures, or any other suitable component. The gross displacement actuators 1206 might include motors, pulleys, etc. By comparing FIGS. 7A , 7 B, and 7 C, actuation of the various gross displacement actuators 1206 adjusts the position of various portions of the shell 1100 relative to the ceiling 1002 , thereby adjusting the magnitude and shape of the volume of the space located beneath shell 1100 , which in turn, directly impacts the acoustics. This gross motor deformation of the shell 1100 , combined with the localized surficial deformation described above provides another layer to the adjustability and dynamically tunable environment that the present disclosure enables.
[0044] While the shells 100 and 1100 thus far disclosed have been described as including panels 106 having two different size triangles in accordance with the rigid origami pattern depicted in FIGS. 1 , 2 , and 6 , for example, this patter is only a single example and the disclosure is not limited thereto. For example, the shells 100 , 1100 could include panels 106 comporting to any suitable contractable/expandable rigid origami patter such as those depicted in FIGS. 8 and 9 . In FIG. 8 , each of the sound absorbing panels 106 b are equally sized triangles, while the sound reflecting panels 106 a are square panels. In FIG. 9 , the panels 106 include a combination of triangular panels 106 a and hexagonal panels 106 b . Any suitable configuration of panels is within the scope of the disclosure. Moreover, in any of the foregoing examples, the identification of which panels are sound reflecting and which are sound reflecting is only by way of example. In FIG. 1 , for example, the shells 100 could be reconfigured such that the larger panels constituted the sound absorbing panels and the smaller panels constituted the sound refleting panels, or still further, some large and small panels could be sound absorbing and/or some large and small panels could be sound absorbing.
[0045] From the foregoing, the various systems and methods of the present disclosure offer advantages by packaging an acoustic solution into a lightweight system capable of aggregation, and can be customized within overarching geometries by substituting panel types into a range of existing spaces and configuration. The dual-actuation capacity (i.e., the surficial and gross volumetric deformations) allows for significant variation in spatial volume. Back-mounted operation via the actuators and suspension systems permit uncluttered exposed surface areas exposed to view and can be constructed to be aesthetically appealing and functional. The system design offers the control of both early acoustic energy (i.e., the sound reflections occurring shortly after the direct sound at both the listener and the performer locations) and late acoustic energy (i.e., diffusion and reverberation) through the sound absorbing and sound reflecting panels as well as dynamic electro-acoustic amplification simultaneously in a single system.
[0046] Finally, the present disclosure is not limited to the examples disclosed in the specification above, but rather, is defined by the spirit and scope of the pending claims and is intended to encompass all variations and substitutions that fall within the claims, as well as the disclosure including the drawings. | A dynamic responsive acoustic tuning envelope system that includes a movably connected set of cells, each possessing sound reflecting, sound absorbing, and/or electro-acoustic properties, and which are assembled according to the principles of rigid origami. So configured, the system is capable of both localized surficial deformation to alter the material surface exposure, transform its textural profile, and alter the enclosed volume of space in a single material envelope, thereby tuning the acoustics of the environment in which the system resides. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of improving the surface insulation resistance of an electrical steel having an insulative surface coating thereon, and more particularly to the subjecting of an electrical steel to at least one electrochemical treating step to remove small metallic particles, nodules or the like extending through or protruding above the insulative coating and which can result in increased watt loss in laminated magnetic structures excited with alternating current because of reduced resistance to interlaminar current flow.
2. Description of the Prior Art
The present invention is applicable to oriented silicon steels with a mill glass coating, carbon steels for electrical uses having an insulative coating thereon, and cold rolled non-oriented silicon steels with an applied insulative coating. The terms "electrical steel" or "electrical steels," as used herein and in the claims, is to be interpreted as encompassing the above noted types of steels. For purposes of an exemplary showing, the present invention will be described in its application to the manufacture of oriented silicon steels. As used herein and in the claims, the term "oriented silicon steel" refers to silicon steel wherein the body-centered cubes making up the grains or crystals are oriented in a cube-on-edge position, designated (110) [001] in accordance with Miller's indices.
Oriented silicon steels are well known in the art and have been chosen for purposes of an exemplary teaching of the present invention because in their typical applications, as for exmaple in the manufacture of transformer cores and the like, surface insulation resistance is of considerable importance.
In recent years prior art workers have devised various routings for the manufacture of oriented silicon steel which have resulted in markedly improved magnetic characteristics. As a result, such oriented silicon steels are now considered to fall into two general catagories. The first catagory is usually referred to as high permeability oriented silicon steel and is made by routings which consistently produce a product having a permeability at 796A/m of greater that about 1850 and typically greater than about 1900. U.S. Pat. No. 3,287,183; 3,636,579; 3,873,234 are typical of those which teach routings for high permeability oriented silicon steel. The second catagory is generally referred to as regular oriented silicon steel and is made by those routings normally producing a permeability of less than about 1850. U.S. Pat. No. 3,764,406 is typical of those which set forth routings for regular oriented silicon steel. The teachings of the present invention are applicable to both types of oriented silicon steel.
With both types of oriented silicon steel the basic steps of the manufacturing process or routing include casting a melt into ingots which are rolled into slabs or continuously casting the melt into slab form. The slabs are reheated, hot rolled to hot band thickness, annealed and cold rolled to final gauge in one or more stages. Following cold rolling, the silicon steel is subjected to a decarburizing step, provided with an annealing separator and subjected to a final box anneal during which the desired final magnetic characteristics are for the most part achieved.
While the above lists the basic steps of the routings for oriented silicon steel, other steps may be included and the precise nature of the routing does not constitute a limitation on the present invention.
In the manufacture of high permeability oriented silicon steel an exemplary melt composition in weight percent may be stated as follows:
Si 2%-4%
C less than 0.085%
Al (Acid-soluble) up to 0.065%
N 0.003%-0.010%
mn 0.02%-0.2%
S and/or Se 0.015%-0.07%
B up to 0.012%
Cu up to 0.5%
Similarly, in the manufacture of regular oriented silicon steel, a typical melt composition by weight percent may be set forth as follows:
C less than 0.085%
Si 2%-4%
S and/or Se 0.015%-0.07%
Mn 0.02%-0.2%
In the manufacture of either type of oriented silicon steel the most common practice is to provide, prior to the final anneal, an annealing separator which (during the final anneal) will form an insulative glass film on the surfaces of the oriented silicon steel. Magnesia, for example, is a typical annealing separator which forms an insulative glass film, as taught in U.S. Pat. Nos. 2,385,332 and 2,906,645. Other exemplary annealing separators are set forth in U.S. Pat. Nos. 3,544,396 and 3,615,918. The insulative glass coating formed by such annealing separators is generally known in the art as a "mill glass". For purposes of this description, such insulative coatings will be termed "primary coatings".
In the manufacture of carbon steels for electrical applications and cold rolled non-oriented silicon steels, a surface insulative coating may be applied. This coating may be of the type caught in U.S. Pat. Nos. 2,501,846 and 3,996,073, or an organic type as taught in U.S. Pat. Nos. 3,865,616; 3,853,971 and 3,908,066. These coatings, which are applied to improve the interlaminar resistance, are intended to be included in the term "primary coatings," as used herein and in the claims.
Excellent surface insulation resistance, or low amperes by the ASTM test method A717 (commonly referred to as the Franklin resistivity test method) is impaired by the presence of small metallic particles or the like extending through or protruding above the surface of the primary insulative coating. The present invention is based upon the discovery that if the oriented silicon steel, having a mill glass formed thereon, is subjected to a continuous electrochemical treatment step, an improvement in surface insulation will occur by virtue of the fact that any small metallic particles extending through or protruding above the mill glass are removed without harming the insulative characteristics of the primary insulative coating or mill glass. Depending upon the quality of the primary insulative coating, average surface insulation resistance improvements equivalent to a change in current of from about 0.67 to about 0.34 amps by ASTM test method 717 may be achieved.
In addition, it is usual practice in the manufacture of transformer cores and the like to provide a secondary coating over the primary coating. Exemplary secondary coatings are taught in U.S. Pat. Nos. 2,501,846 and 3,996,073. A primary function of such applied secondary coatings is to reduce interlaminar eddy currents. With the practice of the present invention less secondary coating may be required since there will be no metallic particles or the like extending through or protruding above the surface of the primary insulative coating. This results not only in a savings of material, but also in the improvement of the space factor characteristics of the oriented silicon steel. A heavy secondary coating is to be avoided since it results in increased cost, a tendency to powder, drying problems, furnace maintenance problems and pimpling of the secondary coating.
SUMMARY OF THE INVENTION
The surface insulation resistance of electrical steels having an insulative coating thereon is improved by subjecting the electrical steels to an electrochemical treatment as a part of the routing thereof.
The electrochemical treatment step may be performed on oriented silicon steel, for example, after the final anneal wherein the desired magnetic characteristics are largely achieved and during which a mill glass is usually formed. The electrochemical treatment step improves the surface insulation resistance of the primary insulative coating or millglass. The strip is caused to continuously pass through an aqueous solution of sodium nitrate or sodium chloride and constitutes the anode. The electrochemical treatment step is followed by rinsing and drying steps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In its simplest form, the invention is practiced upon a cube-on-edge oriented silicon steel strip having a mill glass formed thereon. After the final high temperature anneal during which the desired magnetic properties are largely developed and during which the mill glass is formed, the steel is scrubbed to remove any excess annealing separator. Thereafter, the strip is caused to pass continuously through an electrolyte bath provided with a cathode of stainless steel or the like, the strip, itself, serving as the anode.
To reduce current requirements, two electrolyte baths may be provided, one for each side of the strip. Under these circumstances only one side of the strip will serve as the annode and will be treated in each bath. It will be understood by one skilled in the art that it is within the scope of the invention to treat both sides of the strip simultaneously; to treat the sides of the strip differentially; or to treat only one side of the strip. For purposes of clarity herein and in the claims the examples given and the discussion of current densities are set forth in terms of both sides of the strip being treated simultaneously and equally.
While any appropriate and well known electrolyte may be used, for purposes of an exemplary showing the invention will be discribed in terms of the use of an aqueous solution of sodium nitrate or sodium chloride as an electrolyte. The electrolyte concentration may be up to about 600 grams per liter of water for sodium nitrate and up to about 300 grams per liter of water for sodium chloride. The primary effect of the electrolyte concentration is on the conductivity of the electroyte. The higher the level of concentration, the higher the conductivity and the lower the electrical resistance. This effect of electrolyte concentration, however, decreases as the concentration is increased beyond the recommended concentrations given above. While the conductivity of the electrolyte solution has very little effect on the amount of material removed from the anode during the electrochemical treatment process, it is important when considering the amount of power dissipated during the electrochemical treatment process. The amount of power dissipated can be reduced both by increasing the electrolyte concentration and by decreasing the spacing between the cathode and the oriented silicon steel strip being treated.
During the electrochemical treatment step metal hydroxide, usually insoluble, is formed in the solution as the metal ions leave the anode. In small quantities the metal hydroxide does not significantly affect the process. If allowed to accumulate in large quantitites, however, the metal hydroxide can cause inefficiency and failure of the process. The metal hydroxide precipitate can be removed from the electrolyte through the use of centrifuge separators or gravity settling tanks, as is well known in the art.
In the process of electrochemical treatment, the quantity of metal ions liberated at the anode is independent of the temperature of the electrolyte, the type of electrolyte used or the concentration of the electrolyte. The amount of metal removed from the anode during the electrochemical treatment step is a function of electric current, time and the valence of the metal being treated.
In the practice of the present invention on electrical steels, a theoretical rate of removal can be calculated where the time of immersion in the electrolyte, the current and the valence of the substance being treated is known. The calculated rate of removal should be considered to be only a rough guide since actual valence changes do occur during the electrochemical treatment step. The oriented silicon steel to be treated may be considered, for this purpose, to be pure iron since the silicon of the steel is removed mechanically rather than electrolytically and the other elements of the silicon steel can be ignored due to the practical amounts present. Under these circumstances, the amount of material removed from the silicon steel (i.e. the anode) may be approximated using the following formula:
grams removed = AIt/ZF
where:
A = atomic weight = 55.84 for iron
I = current in amps
t = time in seconds
Z = valance = 2 for iron
F = ne = Faraday's constant = 96500 coulombs
N = avogadro's number = 6.025 × 10 23
e = electron charge = 1.602 × 10 -19
Thus, using a current of 15 amps for an immersion time of 10 seconds, the amount of pure iron removed at the annode in 10 seconds would be:
[(55.84) (15) (10)/(2) (96500)] = 0.043 grams
In the laboratory five series of samples designated A through E were selected, each representing a different quality of mill glass. Series A and B were regular oriented silicon steel, the remaining series C through E being high permeability silicon steel.
Each sample series contained nine strips measuring approximately 3 × 17 × 0.0305 centimeters. The strips of each series were divided into two groups. For example, in series A the first five strips were designated A2-6 and the remaining four strips were designated A7-10. The remaining series were similarly divided. All strips numbered 2 through 6 were electrochemically treated (both sides simultaneously) in a sodium chloride electrolyte and all strips designated 7 through 10 were electrochemically treated (both sides simultaneously) in a sodium nitrate electrolyte. The electrochemical treatment step was performed on all of the strips for a time of 10 seconds at a current of 15 amps. Each strip was weighed to the nearest miligram and a measurement of surface insulation resistance was taken from each surface before treatment by ASTM test method A717. The strips were reweighed and retested for surface insulation resistance after treatment, again using ASTM test method A717. Approximately 12.5 centimeters of the length of each strip was immersed in the electrolyte so that, for the surface area treated, this resulted in a charge density of 2 coulombs/cm 2 (current density of 2000 amps per square meter). The results of this experiment are summarized in the following table.
TABLE I______________________________________Sample Elect-Group W1 W2 W3 Wc I.sub.1 I.sub.2 % olyte______________________________________A2-6 52.759 52.597 .162 .217 .316 .045 85.8 NaClA7-10 43.284 43.097 .187 .174 .394 .045 88.6 NaNO.sub.3B2-6 49.546 49.367 .179 .217 .597 .058 90.3 NaClB7-10 39.458 39.277 .181 .174 .603 .026 95.7 NaNO.sub.3C2-6 56.984 56.764 .220 .217 .486 .240 50.6 NaClC7-10 45.900 45.701 .199 .174 .641 .221 65.5 NaNO.sub.3D2-6 56.597 56.383 .214 .217 .489 .114 76.7 NaClD7-10 44.452 44.266 .186 .174 .493 .046 90.7 NaNO.sub.3E2-6 59.770 59.553 .217 .217 .831 .675 18.8 NaClE7-10 50.502 50.312 .190 .174 .776 .330 56.6 NaNO.sub.3______________________________________
where
W1 = total weight in grams of the samples of each group before treatment.
W2 = total weight in grams of the samples of each group after treatment.
W3 = total weight in grams of material removed from the samples of each group.
Wc = total calculated weight in grams of material removed from the samples of each group.
I 1 = average current in amperes (by ASTM test method A717) of the samples of each group before treatment.
I 2 = average current in amperes (by ASTM test method A717) of the samples of each group after treatment.
% = average percent improvement in amperes of the samples of each group.
For convenience the average percent improvement in amperes by ASTM test method A717 can be used to reflect the surface insulation resistance improvement. The relationship between the ampere reading (I) from ASTM test method A717 and the interlaminar Resistance (Rs) in ohm-cm 2 /lamination is given by the following equation: ##EQU1##
The difference in mill glass quality of the various sample groups is reflected in column I1 of Table I above. The table also shows that the total calculated weight in grams of material removed from the samples of each group roughly approximates the total weight in grams of material actually removed from the samples of each group. In general, the electrochemically treated strips demonstrated marked improvement in surface insulation resistance. The strips which were treated in the sodium nitrate electrolyte demonstrated a greater improvement in surface insulation resistance than the strip treated in the sodium chloride electrolyte. Furthermore, the amount of improvement in surface insulation resistance is related to the quality of the mill glass on the oriented silicon steel. In the above tests a stainless steel cathode was used.
In another test a series of samples were obtained from a single high permeability oriented silicon steel coil. The coil prior to the final anneal during which the majority of its magnetic properties were developed was provided with a magnesia annealing separator. The coil was chosen because the mill glass formed during the final anneal was of excellent quality.
The coil was sheared into samples 15.24 centimeters long and 7.7 centimeters wide which were immersed in a sodium nitrate electrolyte up to about 10.75 centimeters of their length. The samples were divided into groups designated A through D and were tested (both sides simultaneously) at a current of 20 amps and a current density of 1200 amps/m 2 as follows:
TABLE II______________________________________SAMPLEGROUP TREATMENT CHARGE DENSITY______________________________________A. 20 amps/or 30 seconds 3.63 coulombs/cm.sup.2B. 20 amps/or 45 seconds 5.45 coulombs/cm.sup.2C. 20 amps/or 90 seconds 10.89 coulombs/cm.sup.2D. 20 amps/or 180 seconds 21.79 coulombs/cm.sup.2______________________________________
Again, surface insulation resistance measurements (by ASTM test method A717) were made for each sample before and after the electrochemical treatment. The results of this test are summarized in Table III below.
TABLE III______________________________________SAMPLE I.sub.1 I.sub.2 % t______________________________________A. .688 .272 60.5 30B. .677 .165 75.6 45C. .767 .066 91.4 90D. .640 .075 88.3 180______________________________________
Where:
I1 = average current in amperes (by ASTM test method A717) of the samples of each group before treatment.
I2 = average current in amperes (by ASTM test method A717) of the samples of each group after treatment.
% = average percent improvement in amperes of the samples of each group.
t = treatment time in seconds
An improvement in surface insulation resistance was achieved with respect to each sample after the electrochemical treatment. After a treatment at a charge density of 3.63 coulombs/cm 2 an average improvement in surface insulation resistance of 60.5% was recorded. At treatments at a charge density greater than 3.63 coulombs/cm 2 the improvement in surface insulation resistance increased, but at a less pronounced rate. Finally, at treatments at a charge density greater than 1089 coulombs/cm 2 improvement in the surface insulation was not significant. On the other hand, at treatments at a charge density greater than 10.89 coulombs/cm 2 metallic removal began in regions of exposed base metal forming small pits. Metal removal then spread to adjacent regions beneath the glass film creating voids thereunder.
In view of the above, the present invention may be successfully practiced utilizing, for example, either a sodium nitrate or sodium chloride electrolyte. For sodium chloride-containing electrolytes, a concentration of up to 300 grams per liter of water may be used and it is preferred that the concentration be at or near 300 grams per liter of water to reduce the amount of power dissipated by the electrochemical treatment step. A sodium nitrate electrolyte is preferred and concentrations up to about 600 grams per liter of water may be used. Again it is preferred that the concentration be at or near 600 grams per liter of water for power dissipation considerations.
While the container for the electrolyte may serve as the cathode, it is preferred, for reasons of safety to provide a cathode of stainless steel or the like. Again for purposes of power conservation, it is preferable that the distance between the cathode and the oriented silicon steel being treated be minimized as much as is practical.
The current densities and length of time at which the electrochemical treatment is conducted should be selected largely on the basis of the quality of the insulative film on the oriented silicon steel being treated. This is well within the skill of the worker in the art and is based upon a trade-off between improvement in surface insulation resistance and possible damage to the base metal underlying the coating. Such damage, where severe, is harmful to the physical appearance and the magnetic properties of the oriented silicon steel. Also, when such damage is severe, adherance of a secondary applied coating may be poor in the damaged areas.
The fewer the number of metallic particles extending through or protruding above the surface of the primary insulative coating, the shorter the required time for effective treatment. With shorter times, there is less chance for damage due to over-treatment.
The electrochemical treatment step, should not exceed a charge density of about 10.89 coulombs/cm 2 because improvements in surface insulation resistance at charge densities thereabove are not significant. For most purposes, the electrochemical treatment step may be conducted at charge densities of from about 3.63 couloumbs/cm 2 to about 5.45 coulombs/cm 2 . If the insulative coating is relatively free of metallic particles extending therethrough or thereabove, a current density of up to about 3.63 coulombs/cm 2 will normally suffice.
In practice, once a current density and length of treatment time (i.e. charge density) have been established to produce optimum results, the current density and time of treatment may be adjusted to different values and still produce the same results. It may be necessary to make the above mentioned adjustments in order to facilitate a particular method of electrochemical treatment for mill glass material. For example, if the maximum time of treatment was limited to 10 seconds, but the optimum time was 30 seconds at a current density of 1200 amps/m 2 . (i.e. a charge density of 3.6 coulombs/cm 2 ), a new value for current density may be calculated for 10 second treatment time using the following.
where:
Q = 1200 amps/m 2 times 30 seconds = optimum value
t = time of treatment = 10
Id = New current density
Id = Q/I = 3600 amps/m2 at 10 seconds = a charge density of 3.6 coulombs/cm 2
In regular commercial practice it would be normal procedure to maintain a constant line speed and vary the current to achieve the desired charge density.
The electrochemical treatment of the present invention will be followed by a water rinse step and a drying step. Such rinsing and drying steps are well known in the art. The drying step may be accomplished, for example, by air blowing.
Modifications may be made in the invention without departing from the spirit of it. | A method of improving the surface insulation resistance of electrical steels having an insulative coating thereon by subjecting the electrical steels to electrochemical treatment as part of the routing thereof, to remove small metallic nodules, particles and the like extending through or protruding above the insulative coating. Following the electrochemical treatment, the electrical steels are rinsed and dried. | 7 |
TECHNICAL FIELD
[0001] The invention relates generally to a multi-channel wavelength division multiplexer/demultiplexer. More particularly, the invention relates to a multi-channel wavelength division multiplexer/demultiplexer, which can increase the number of the wavelength channel of inputted wavelength-multiplexed optical signals through a band splitting filter or a 50:50 optical intensity splitter to minimize the optical loss of wavelength channels.
BACKGROUND OF THE INVENTION
[0002] Conventional wavelength division multiplexers/demultiplexers typically used an arrayed waveguide grating (hereinafter called “AWG”), a multi-channel optical filter using a thin film filter, or a cascade type Mach-Zehnder interferometer filter. As the above three types of optical devices used for conventional wavelength division multiplexer/demultiplexer have limited number of channels between 16 channels to 32 channels. Thus, the conventional wavelength division multiplexer/demultiplexer has a problem that it may not meet the need of increased wavelength channels.
[0003] Recently, in order to cope with the need for the rapidly-increasing communication traffic, tera-bit optical transmission is required. For this purpose, several hundreds of wavelength channels are also required. Due to this, there is an increasing need for a device that can effectively couple and separate a plurality of wavelength division multiplexed (WDM) optical signals using a single wavelength division multiplexer/demultiplexer having limited number of channels.
[0004] [0004]FIG. 1 is a block diagram of a conventional single wavelength division demultiplexer. Referring now to FIG. 1, the operation of conventional demultiplexer and multiplexers will be explained below. It can be assumed that the operation and structure of the multiplexer is an inversed version of those of the demultiplexer. Thus, only the operation and structure of the demultiplexer will be explained for simplicity. As shown in FIG. 1, if the WDM optical signals (λ 1 ˜λ n ) are inputted to the wavelength division demultiplexer 100 , the demultiplexer 100 divides the inputted WDM optical signals into respective wavelength and then outputs the results to corresponding output terminals. As this type of the wavelength division multiplexer/demultiplexer has a very limited number (less than 32) of wavelength channels into which the optical signals can be separated, it is difficult for the multiplexer/demultiplexer to handle wavelength optical signals of several hundreds of channels.
[0005] As another technology, there is a multi-channel (over 32) wavelength division demultiplexer for overcoming the shortcomings of the single wavelength division demultiplexer as shown in FIG. 1. The multi-channel wavelength division demultiplexer includes one 1×M optical intensity splitter in the conventional single wavelength division demultipliexer, as shown in FIG. 2.
[0006] [0006]FIG. 2 is a block diagram of a conventional multi-channel wavelength division demultiplexer. The multi-channel wavelength division demultiplexer 220 includes one 1×M optical intensity splitter 210 and the M units of demultiplexers 220 . The multi-channel wavelength division demultiplexer divides the wavelength multiplexed optical signals (λ 1 ˜λ n ) inputted to the 1×M optical intensity splitter 210 into M components according to their light intensity and input the results to the M units of demultiplexer 220 . Then, the demultiplexer 220 separates the inputted optical signals into multiple channels (optical signal provided to each channel consists of n wavelength multiplexed optical signals) and then outputs the separated optical signal to corresponding output terminals. Though this type of multi-channel wavelength division demultiplexer can increase number of channels to the number of wavelength channel, there is a disadvantage that optical loss (10×logM) is also increased as the number of channel is increased.
[0007] Another technology regarding the wavelength channel selector was disclosed in an article by F. Ebisawa et al., “High speed 32-channel optical wavelength selector using PLC hybrid integration” Proceeding of OFC '99, ThB1, 1999, pp. 8-20. The high-speed 32-channel optical wavelength selector consists of a 32-channel wavelength separator and a wavelength combiner using a single AWG, and the corresponding wavelength channels of the two devices are connected to semiconductor amplifier optical switches. Although this technology constitutes a wavelength channel selector using a single AWG, there is a disadvantage that the number of channel is limited to 32 channels.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to unlimitedly extend the number of wavelength channels of continuous wavelength multiplexed optical signal using a optical intensity splitter and a band splitting filter (BSF). Further, the present invention has an object to provide a multi-channel wavelength division multiplexer/demultiplexer capable of significantly increasing the number of available wavelength channels while minimizing optical loss of respective wavelength channels.
[0009] In order to accomplish the above objects, present invention provides a multi-channel wavelength division multiplexer/demultiplexer for coupling/separating inputted wavelength multiplexed optical signals characterized by comprising band splitting means for splitting the band of wavelength multiplexed optical signals (λ 1 ˜λ n ) into M bands, demultiplexing means for separating each band split by the band splitting means into a plurality of single wavelength channels, and multiplexing means for coupling said single wavelength channels separated by said demultiplexing means.
[0010] Also, a multi-channel wavelength division multiplexer/demultiplexer for coupling/separating inputted wavelength multiplexed optical signals according to the present invention is characterized in that it comprises optical intensity splitting means for reducing the intensity of inputted wavelength multiplexed optical signals (λ 1 ˜λ n ) by half, band splitting means for splitting the band of the wavelength multiplexed optical signals provided by the optical intensity splitting means into even-number bands and odd-number bands, demultiplexing means for separating the wavelength channels of each band split by the band splitting means into a plurality of single wavelength channels, and multiplexing means for coupling said single wavelength channels separated by the demultiplexing means.
[0011] In another aspect of the invention, the present invention provides a wavelength channel selector for selecting desired wavelength channels from the wavelength channels of inputted wavelength multiplexed optical signals characterized by comprising a band splitting means for splitting the band of wavelength multiplexed optical signals (λ 1 ˜λ n ) into M bands, a demultiplexing means for separating the wavelength channels of each band split by the band splitting means into a plurality of single wavelength channels, a wavelength channel selecting means for selecting desired single wavelength channels from the wavelength channels separated by the demultiplexing means; and a multiplexing means for coupling the single wavelength channels selected by the wavelength channel selecting means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The aforementioned aspects and other features of the present invention will be explained in the following description, taken in conjunction with the accompanying drawings, wherein:
[0013] [0013]FIG. 1 is a block diagram of a conventional single wavelength division demultiplexer;
[0014] [0014]FIG. 2 is a block diagram of a conventional multi-channel wavelength division demultiplexer;
[0015] [0015]FIG. 3 a is a block diagram of a multi-channel wavelength division demultiplexer using an 1×M band splitting filter (BSF) according to one embodiment of the present invention, and FIG. 3 b is a diagram illustrating the band pass characteristic of the 1×M BSF shown in FIG. 3 a;
[0016] [0016]FIG. 4 a is a block diagram of a multi-channel wavelength division demultiplexer using a 50:50 optical intensity splitter and two BSF's according to another embodiment of the present invention, and FIG. 4 b is a diagram illustrating the band pass characteristic of the two BSF's; and
[0017] [0017]FIGS. 5 a and 5 b illustrate a wavelength channel selector using a multi-channel wavelength division multiplexer/demultiplexer according to embodiments of the present invention, and FIG. 5 c illustrates a detailed structure of the wavelength selectors in FIG. 5 b.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention will be described in detail by way of a preferred embodiment with reference to accompanying drawings, in which like reference numerals are used to identify the same or similar parts.
[0019] [0019]FIG. 3 a is a block diagram of a multi-channel wavelength division demultiplexer using a band splitting filter (BSF) according to one embodiment of the present invention, and FIG. 3 b is a diagram illustrating the band pass characteristic of the two BSF's shown in FIG. 3 a.
[0020] The multi-channel wavelength division demultiplexer in FIG. 3 a includes an 1×M band splitting filter 310 for dividing the bands of inputted wavelength multiplexed optical signals into M bands, instead of the 1×M optical intensity splitter 210 shown in FIG. 2. The 1×M optical intensity splitter 210 , however, can cause more optical loss as the number of wavelength channels increases. Using the band splitting filter in place of the optical intensity splitter, the present invention may prevent the optical loss caused by the increased number of wavelength channels.
[0021] The operation of the multi-channel wavelength division demultiplexer having this structure will be explained below. The wavelength division multiplexed optical signals (λ 1 ˜λ n ) are inputted to the 1×M band splitting filter 310 , where they are then separated into M bands. The wavelengths of the optical signals are inputted to the M units of demultiplexers 320 , where the optical signals are separated into respective wavelength channels.
[0022] The term of “band” used in the present invention means a set of a certain number of different types of continuous single wavelength. For example, a bundle of continuous single wavelengths from wavelength λ 1 to λ 32 constitute one band. The present invention assumes that there exist M bands.
[0023] [0023]FIG. 3 b illustrates the band pass characteristic of the 1×M BSF shown in FIG. 3 a. As shown in FIG. 3 b, in the multi-channel wavelength division demultiplexer using the 1×M band division filter 310 , the M band covers the entire wavelength region of the optical signals. Therefore, the multi-channel wavelength division demultiplexer can prevent the loss of input optical signal due to the increased number of channels. In the multi-channel wavelength division demultiplexer in FIG. 3, however, the intensity of the optical signals between wavelength channels may vary due to the low transmitted intensity at the start and end portions of each of band.
[0024] [0024]FIG. 4 a is a block diagram of a multi-channel wavelength division demultiplexer using a 50:50 optical intensity splitter according to another embodiment of the present invention and FIG. 4 b illustrates the band pass characteristic of the BSF 1 and the BSF 2 of FIG. 4 a.
[0025] The multi-channel wavelength division demultiplexer according to a second embodiment of the present invention is characterized in that it comprises a single 50:50 optical intensity splitter 410 and two band splitting filters 420 and 420 ′, compared to the multi-channel wavelength division demultiplexer using the band splitting filter as shown in FIG. 3 a.
[0026] The operation of the multi-channel wavelength division demultiplexer according to a second embodiment of the present invention will be explained below. First, the intensity of wavelength multiplexed optical signals (λ 1 ˜λ n ) inputted to the 50:50 optical intensity splitter 410 is bisected as the optical signals pass through the optical intensity splitter 410 . Then, the optical signals are respectively inputted to the first and second band splitting filters 420 and 420 ′. In other words, the wavelength multiplexed optical signals (λ 1 ˜λ n ) the intensity of which is reduced by half are respectively inputted to the first and second band splitting filter 420 and 420 ′.
[0027] Then, the first and second band splitting filters 420 and 420 ′ divide the inputted optical signals (λ 1 ˜λ n ) into each bands. That is, the first band splitting filter 420 divides odd-numbered bands (1, 3, . . . , M-3, M-1) among the entire bands (M) of the inputted optical signals. On the other hand, the second band splitting filter 420 ′ divides the remaining even-numbered bands (2, 4, . . . , M-3, M) among the entire bands (M) of the inputted optical signals. Therefore, the bands of the inputted wavelength multiplexed optical signals are divided into optical signals of even-numbered bands and odd-numbered bands. Thereafter, the optical signals divided into two types of bands are inputted to the M units of demultiplexer 430 . At this time, the optical signals of the even-numbered bands are inputted to the even-numbered demultiplexers while the optical signals of the odd-numbered bands are inputted to the odd-numbered demultiplexers, respectively. Next, the optical signals are separated into respective wavelength channels by the demultiplexers 430 .
[0028] [0028]FIG. 4 b illustrates the band pass characteristic characteristic of the BSF 1 and BSF 2 of FIG. 4 a. The multi-channel wavelength division demultiplexer according to a second embodiment of the present invention prevents optical loss occurring at the start and end portions of each bands as shown in FIG. 3 b because the band ranges of the optical signals demultiplexed by the odd-numbered and even-numbered demultiplexers partially overlap with each other as shown in FIG. 4 b. Thus, the intensity of signals between wavelength channels does not vary. This is because the transmission band of the two band splitting filters 420 and 420 ′ has an asymmetric characteristic that is wider than a block band.
[0029] Although the multi-channel wavelength division demultiplexer having this characteristic prevents a total loss of a certain wavelength signal, it may still cause optical loss of about 3dB due to use of the 50:50 optical intensity splitter 410 . However, this is only a theoretical numeral and an actual optical loss becomes the sum of the optical loss of 3dB, the insertion loss due to the band splitting filter, and the insertion loss due to the optical coupler.
[0030] [0030]FIGS. 5 a and 5 b illustrate a wavelength channel selector using the multi-channel wavelength division multiplexer/demultiplexer having the above-mentioned characteristic. FIG. 5 a illustrates a wavelength channel selector according to a first embodiment of the present invention using the multi-channel wavelength division multiplexer/demultiplexer shown in FIG. 3 a. FIG. 5 b illustrates a wavelength channel selector according to a second embodiment of the present invention using the multi-channel wavelength division multiplexer/demultiplexer shown in FIG. 4 a.
[0031] First, as shown in FIG. 5 a, the wavelength channel selector includes two 1×M band splitting filters 510 and 510 ′ and M units of wavelength selectors 520 . Each wavelength selector 520 includes a demultiplexer 521 , an optical switch 522 and a multiplexer 523 .
[0032] The operation of the wavelength channel selector having this structure will be explained below. First, wavelength multiplexed signals inputted to the first band splitting filter 510 are divided into every M bands. At this time, each band consists of different single 32 wavelengths. Then, the even-numbered bands (2, 4, . . . , M-2, M) among the divided bands are inputted to the demultiplexers of corresponding even-numbered wavelength selectors while the odd-numbered bands (1, 3, . . . , M-3, M-1) among the divided bands are inputted to the demultiplexers of corresponding odd-numbered wavelength selectors, respectively. Thereafter, the wavelengths of the optical signals of even-numbered and odd-numbered bands inputted to the demultiplexers are separated into each wavelength channel. Among the optical signals demultiplexed into separate wavelength channels, only wavelength channels selected by the optical switch 522 are outputted. Next, one or more wavelength channels selected in each band are inputted to respective multiplexer 523 . The selected wavelength channels of each band are multiplexed for each band by means of the multiplexers 523 , so that the wavelength channels selected within the entire bands (even and odd bands) are outputted by the second band splitting filter 510 ′.
[0033] At this time, the 1×M band splitting filters 510 and 510 ′ used in the wavelength channel selectors having this characteristic may include a thin film interference filter. Also, the wavelength division multiplexer/demultiplexer 521 and 523 may include an AWG, a thin film interference filter, or a Mach-Zehnder interferometer filter connected in series.
[0034] [0034]FIG. 5 b illustrates a wavelength channel selector that has a little optical loss but a good transmission characteristic and that can use all the bands of received wavelength multiplexed optical signals. The wavelength channel selector is different from the wavelength channel selector shown in FIG. 5 a in that it comprises 50:50 optical intensity splitters 530 and 530 ′ and two sets of band splitting filters 540 , 540 ′ and 560 , 560 ′.
[0035] The operation of the wavelength channel selector having the above structure will be explained below. First, the intensity of input wavelength multiplexed optical signals is bisected as they pass through the 50:50 optical intensity splitter 530 . The optical signals are inputted to two band splitting filters 540 , 540 ′. Each of the band splitting filters 540 , 540 ′ splits the input optical signals into M bands. Preferably, each of M bands consists of 32 different single wavelengths. In FIG. 5 b, band splitting filter 540 provides odd-number band to the odd-number wavelength selector 550 and band splitting filter 540 provides even-number band to the even-number wavelength selector 550 ′.
[0036] [0036]FIG. 5 c illustrates a detailed structure of the odd-number wavelength splitter 550 connected between the band splitting filters 540 and 560 . The even-number wavelength splitter 550 ′ has the same structure as the odd-number wavelength splitter 550 , thus the explanation on the even-number wavelength splitter 550 ′ is omitted.
[0037] As shown in FIGS. 5 b and 5 c, odd-number bands among the M bands divided by the first band splitting filter 540 are inputted to the respective demultiplexers of odd-number wavelength selectors 550 . The odd-number wavelength selectors consist of wavelength selectors 1, 3, . . . , M-1 and they respectively receive odd-number bands 1, 3, . . . , M-1 from the band splitting filter 540 . In the same manner, even-number wavelength selectors 550 ′ consist of wavelength selectors 2, 4, . . . , M and they respectively receive even number bands 2, 4, . . . , M from the band splitting filter 540 ′. Thereafter, each band of optical signals inputted to each of the wavelength selectors are separated into a plurality of wavelength channels (e.g. 32 channels) by a demultiplexer 521 . Among the separated single wavelength channels, only one or more single wavelengths selected by the optical switches 552 are outputted. Then, the optical signals for each band consisting of a plurality of thus selected wavelengths are multiplexed by the multiplexer 523 and outputted to corresponding output terminals. Thereafter, the optical signals of each band, which is outputted by multiplexing selected wavelengths, are divided two groups of bands (i.e. optical signals of even-number bands and odd-numbered bands) by means of the two band splitting filters 560 , 560 ′. Then, the intensity of wavelength multiplexed optical signals of even-number bands and odd-number bands provided by the two band splitting filters 560 , 560 ′ is bisected by half while passing through the 50:50 optical intensity splitter 530 ′. Thus, multiplexed optical signals of a plurality of selected wavelengths are outputted.
[0038] The band splitting filters 540 , 540 ′, 560 , 560 ′ used in the wavelength channel selector having this characteristic may use a thin film interference filter. Also, the wavelength division multiplexer/demultiplexer 521 and 523 may use an AWG, a thin film interference filter, or a Mach-Zehnder interference filter connected in series.
[0039] As can be understood from the above description, the present invention employs an optical intensity splitter for dividing the intensity of inputted optical signals and two band splitting filters for splitting the inputted optical signals into a plurality of bands. Thus, the present invention can minimize the optical loss of each wavelength channels and loss of certain wavelength signals due to poor transmission characteristic. Further, the present invention can increase the number of available wavelength channels without a limit.
[0040] The present invention has been described with reference to a particular embodiment in connection with a particular application. Those having ordinary skill in the art and access to the teachings of the present invention will recognize additional modifications and applications within the scope thereof.
[0041] It is therefore intended by the appended claims to cover any and all such applications, modifications, and embodiments within the scope of the present invention. | The present invention relates to a multi-channel wavelength division multiplexer/demultiplexer capable of efficiently coupling or separating wavelength multiplexed optical signals. The multi-channel wavelength division multiplexer/demultiplexer according to the present invention comprises a band splitting means for splitting the band of wavelength multiplexed optical signals (λ 1 ˜λ n ) into M bands, a demultiplexing means for separating each band split by the band splitting means into a plurality of single wavelength channels, and a multiplexing means for coupling the single wavelength channels separated by the demultiplexing means. Therefore, the present invention can significantly increase the number of available wavelength channels while minimizing optical loss of wavelength channels. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to memory devices and, more particularly, to methods and circuits for reading information into and out of the memory device.
[0003] 2. Description of the Background
[0004] Computer designers are continually searching for faster memory devices that will permit the design of faster computers. A significant limitation on a computer's operating speed is the time required to transfer data between a processor and a memory circuit, such as a read or write data transfer. Memory devices such as dynamic random access memories (DRAMs), synchronous dynamic random access memories (SDRAMs), flash memories, etc. typically include a large number of memory cells arranged in one or more arrays, each array comprised of rows and columns. Each memory cell provides a location at which the processor can store and retrieve one bit of data, sometimes referred to as a memory bit or m-bit. The more quickly the processor can access the data within the memory cells, the more quickly it can perform a calculation or execute a program using the data.
[0005] [0005]FIG. 1 shows, in part, a typical computer system architecture. A central processing unit (CPU) or processor 10 is connected to a processor bus 12 , which in turn is connected to a system or memory controller 14 . The memory controller 14 may be connected to an expansion bus 16 . The memory controller 14 serves as interface circuitry between the processor 10 and a memory device 18 . The processor 10 issues a command and an address which are received and translated by the memory controller 14 . The memory controller 14 applies the translated command signals on a plurality of command lines 20 and the translated address on a plurality of address lines 22 to the memory device 18 . These command signals are well known in the art and include, in the case of a DRAM, RAS (row address strobe), CAS (column address strobe), WE (write enable) and OE (output enable), among others. A clock signal is also provided on CLK lines 24 . Corresponding to the processor-issued command and address, data is transferred between the controller 14 and the memory 18 via datapath lines 26 .
[0006] Methods exist to enable memory devices, such as DRAM memory 18 , to appear to external devices to be operating faster than the time it takes for the memory device to retrieve data from the array. These methods include pipeline and prefetch methods of operation. The pipeline method divides internal processing into a number of stages and sequentially processes information relating to one unit of data through each stage. Processing in each stage is carried out simultaneously in parallel, such that the rate at which data can be output from the device can be greater than the rate at which data is retrieved from the array. In the prefetch method, all internal processing is carried out in parallel, and parallel to serial conversion is performed at the input/output section.
[0007] Both the pipeline and prefetch methods can be used to support, for example, a burst mode of operation. The burst mode of operation is a mode of operation in which the starting address for a data string is provided to the memory device. The data string to be read out of the memory or written into the memory is then synchronously output or input, respectively, with a clock signal.
[0008] Historically, synchronous DRAMs have supported both an interleaved and a sequential burst mode of operation. Advance DRAM technology standards are being defined with an 8-bit external prefetch and capability to support a 4-bit or 8-bit internal prefetch. With a 4-bit internal prefetch, the sequential read or write crosses a boundary and is therefore difficult to implement as illustrated by the following table, Table 1.
TABLE 1 Starting Internal Bits Internal Bits Address [0 1 2 3] [4 5 6 7] 0 0 1 2 3 4 5 6 7 1 1 2 3 4 5 6 7 0 2 2 3 4 5 6 7 0 1 3 3 4 5 6 7 0 1 2 4 4 5 6 7 0 1 2 3 5 5 6 7 0 1 2 3 4 6 6 7 0 1 2 3 4 5 7 7 0 1 2 3 4 5 6
[0009] As seen from Table 1, except for starting addresses 0 and 4, the sequential burst cannot be executed without an 8-bit internal burst, adding cost, or a dual prefetching, which adds latency.
[0010] The existing interleave burst mode supports a 4-bit internal prefetch but some applications still use a sequential type of access burst mode. One solution is to always start the read burst at index 0 and sequence through the data. That solution is acceptable only when the word stored at index 0 is the next critical word. If the critical word is indexed at any other location, latency is introduced.
[0011] Thus, the need exists for a method and apparatus for enabling both 8-bit and 4-bit internal prefetches for new architectures without adding cost or latency to the new architecture.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a memory device comprising a plurality of arrays of memory cells and peripheral devices for reading information out of and for writing information into the memory cells. The peripheral devices include a decode circuit responsive to a first portion of address information for identifying an address and is further responsive to a second portion of the address information for identifying an order. The address may be a read address or a write address, and the order may be the order for reading data or writing data, respectively.
[0013] The present invention also includes a read sequencer circuit or both a write sequencer circuit and a read sequencer circuit for reordering bits to be written to or read from, as the case may be, the memory in response to another portion of the address information. The necessary address information is routed to the sequencer circuits by an address sequencer.
[0014] The present invention is also directed to a method of reading a word from a memory array in at least two prefetch operations, wherein the order of the prefetch operations is controlled by an address bit, or writing a word in two n-bit bytes under the control of the address bit.
[0015] In one implementation of the present invention, the new burst sequence splits, for example, an 8-bit burst into two 4-bit bursts with a sequential interleave within each burst sequence. That enables each of the 4-bit bursts to be output from a memory array before the 8-bit burst is required to be output from the memory device. To implement that operation, the most significant column address bits (for example CA 3 -CAi) identify which 8-bit burst is selected. Those address bits may be referred to as a first portion of the address information. Address bit CA 2 , referred to as a second portion of the address information, identifies which of the two 4-bit bursts are fetched first from the memory array. CA 0 and CA 1 may then be used to identify which of the prefetched 4-bits are to be asserted first, with the remaining 3 bits output in sequential order from the first bit.
[0016] The present invention allows sequential type of interleaves for applications requiring them and provides access to the most critical word first without adding any latency to the system. Those, and other advantages and benefits, will become apparent from the detailed description of the preferred embodiments hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For the present invention to be easily understood and readily practiced, the present invention will now be described, for purposes of illustration and not limitation, in conjunction with the following figures, wherein:
[0018] [0018]FIG. 1 is a functional block diagram of a computer system architecture;
[0019] [0019]FIG. 2 is simplified block diagram of an architecture for implementing the present invention;
[0020] [0020]FIGS. 3A and 3B are timing diagrams comparing a 4-bit prefetch to an 8-bit prefetch, respectively; and
[0021] [0021]FIG. 4 is a simplified block diagram of a computer system in which the present invention may be used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Advanced DRAM technology (ADT) specifies an 8-bit external prefetch and supports either a 4 or 8-bit internal prefetch. Typical DRAMs support a sequential and an interleaved burst mode of operation. However, a sequential interleave is not compatible with a DRAM having a double pumped 4-bit internal prefetch DRAM architecture. The present invention allows for a new burst ordering sequence to support a multiple internal prefetch architecture for applications requiring a sequential-like burst sequence. The present invention allows sequential types of interleaves for applications requiring them, and provides access to the most critical word first.
[0023] Turning now to FIG. 2, FIG. 2 illustrates a simplified block diagram of an architecture for a DRAM capable of implementing the present invention. The DRAM memory device 29 is comprised of a command/address input buffer 30 responsive to a command bus or command lines and an address bus or address lines. A command decoder and sequencer 32 and an address sequencer 34 are each responsive to the command/address input buffer 30 .
[0024] A bank address decoder 36 is responsive to the address sequencer 34 while bank control logic 38 is responsive to the bank address decoder 36 . A series of row latch/decoder/drivers 40 is responsive to the bank control logic 38 and the address sequencer 34 . One row latch/decoder/driver 40 is provided for each memory array 42 . Illustrated in FIG. 2 are four memory arrays labeled bank 0 through bank 3 . Accordingly, there are four row latch/decoder/driver circuits 40 each responsive to one of bank 0 through bank 3 .
[0025] A column latch/decode circuit 44 is responsive to the address sequencer 34 . The column latch/decode circuit 44 receives the most significant bits of the column address CA 3 -CAi, where “i” in the present example equals 9. The most significant bits CA 3 -CAi may be thought of as a first portion of the address and is used for identifying a word to be read. The column latch/decode circuit 44 also receives one of the least significant column address bits CA 0 -CA 2 ; in the present example, the column latch/decode circuit 44 receives the column address bit CA 2 which may be referred to as a second portion of the address. The identified word which is to be read may be, for example, an 8-bit word. The word will be read in two 4-bit bytes, and the second portion of the address identifies which of the first or the second n-bit bytes is to be read first.
[0026] An I/O gating circuit 46 is responsive to the column latch/decode circuit 44 for controlling sense amplifiers within each of the memory arrays 42 .
[0027] The DRAM 29 may be accessed through a plurality of data pads 48 for either a write operation or a read operation. For a write operation, data on data pads 48 is received by receivers 50 and passed to input registers 52 . A write sequencer circuit 54 orders the two 4-bit bytes comprising each 8-bit byte in response to, for example, column address bits col 0 - 1 . The ordered bytes are then input to a write latch and driver circuit 56 for input to the memory arrays 42 through the I/O gating circuit 46 . Data which is to be read from the memory arrays 42 is output through the I/O gating circuit 46 to a read latch 58 . From the read latch 58 , the information is input to a read sequencer circuit 60 which orders the read data in response to, for example, column address bits col 0 - 1 . The ordered data is then output to an output mux 62 and then onto the data pads 48 through drivers 64 .
[0028] The command/address input buffer 30 , command decoder and sequencer 32 , address sequencer 34 , bank address decoder 36 , bank control logic 38 , the row latch/decoder/drivers 40 , column latch decode circuit 44 , I/O gating circuit 46 , the receivers 50 , input registers 52 , write sequence circuit 54 , write latch and driver circuit 56 , read latch 58 , read sequence circuit 60 output mux 62 and drivers 64 are considered to be a plurality of peripheral devices for reading information out of and writing information into the memory cells of the arrays. The description of the forgoing elements as a plurality of peripheral devices is intended to provide a description of the presently preferred embodiment, and is not intended to limit the scope of the invention to only the recited devices. Those of ordinary skill in the art will recognize that other combinations of devices may be used to implement the plurality of peripheral devices, particularly where other memory architectures are used.
[0029] In general terms, the purpose of the read sequencer circuit 60 is to reorder the prefetched portions of the read word in response to certain the least significant address bits CA 0 -CA 2 ; in this example CA 0 and CA 1 are used.
[0030] The first n-bit prefetch (in this example, the first 4-bit prefetch identified by CA 2 ) reordered according to the start address identified by CA 0 and CA 1 as follows:
Starting Internal Bits Internal Bits Address [0 1 2 3] [4 5 6 7] 0 0 1 2 3 4 5 6 7 1 1 2 3 0 5 6 7 4 2 2 3 0 1 6 7 4 5 3 3 0 1 2 7 4 5 6 4 4 5 6 7 6 1 2 3 5 5 6 7 4 1 2 3 0 6 6 7 4 5 2 3 0 1 7 7 4 5 6 3 0 1 2
[0031] In operation, when a read command is received, the value on the bank address inputs BA 0 and BA 1 (not shown) selects one of the memory arrays 42 . Address information is then received which identifies a row or rows within each array 42 . The address provided on inputs CA 3 through CAi (where “i” in the present example equals 9) selects the starting column location. Referring to FIG. 2, CA 3 -CA 9 are input to the column latch/decode circuit 44 to identify a word to be read. CA 2 is also input to the column latch/decode circuit 44 for the purpose of identifying which portion of the word is to be read first. The bits CA 0 and CA 1 are input to the read sequencer circuit 60 . That information identifies the start address such that the bits can be reordered thereby enabling the most critical word to be output first by the mux 62 .
[0032] For a write operation, the bank is identified in the same manner as for a read operation. Similarly, the starting column address is identified in the same manner. The signals available at inputs CA 0 -CA 2 are input to write sequencer 54 which reorders the bits as described. Although FIG. 2 shows both a write sequencer circuit 54 and a read sequencer circuit 60 , the memory can operate with just the read sequencer circuit 60 .
[0033] [0033]FIG. 3A illustrates a timing diagram for an 8-bit external prefetch using a 4-bit internal prefetch. As can be seen, after the read latency period, the data available at the output pads appears as an 8-bit byte, although the word was constructed from two 4-bit bytes. While the first 8-bit byte is made available at the data pads, a next 8-bit byte can be processed internally in two 4-bit prefetches as shown in the figure. In contrast, in FIG. 3B, the 8-bit byte is prefetched from the memory in one step.
[0034] The timing diagram illustrated in FIG. 3A is the timing diagram for a 4-bit double pumped array. The array runs at a frequency of ¼ that of the IO frequency. Because not all 8 bits of data may be available for data scramble prior to the memory device outputting data to the external data pads, a data scramble must be performed on the 4 bit boundaries. That places a limit on the maximum data frequency that can be supported.
[0035] The timing diagram illustrated in FIG. 3B illustrates an 8-bit single pumped array. That array runs at a frequency of ⅛ of that of the data frequency. All 8 bits are available for data scramble prior to outputting data to the data pads, such that the output scramble may be completed on an 8 bit byte. The maximum data frequency is scaleable (the core is not a limiting factor) at the expense of die size.
[0036] Advantages of the present invention include the ability to support 4-bit internal prefetches at low cost with no addition to device latency, the critical word needed by the system is output first, and a sequential type burst for applications not supporting interleaved bursts is possible.
[0037] The present invention is also directed to a method of reading a word from a memory array in at least two prefetch operations, wherein the order of the prefetch operations is controlled by at least one address bit. The present invention is also directed to a method of outputting an n-bit word in two ½ n-bit prefetch steps from a plurality of memory arrays in response to an address bit. The present invention is also directed to a method comprised of prefetching the first portion of a word from a memory array and prefetching a second portion of the word from the memory array in an order determined by an address bit.
[0038] [0038]FIG. 4 is a block diagram of one example of a computer system 110 in which the present invention may be implemented. The computer system 110 includes a processor 112 , a memory subsystem 114 , and an expansion bus controller 116 . The memory subsystem 114 and the expansion bus controller 116 are coupled to the processor 112 via a local bus 118 . The expansion bus controller 116 is also coupled to at least one expansion bus 120 , to which various peripheral devices 121 - 123 such as mass storage devices, keyboard, mouse, graphic adapters, and multimedia adapters may be attached. Processor 112 and memory subsystem 114 may be integrated on a single chip.
[0039] The memory subsystem 114 includes a memory controller 124 which is coupled to a plurality of memory modules 125 , 126 via a plurality of signal lines 129 , 130 , 129 a , 130 a , 129 b , 130 b , 129 c and 130 c . The plurality of data signal lines 129 , 129 a , 129 b , 129 c are used by the memory controller 124 and the memory modules 125 , 126 to exchange data DATA. Addresses ADDR are signaled over a plurality of address signal lines 132 , clock signals CLK are applied on a clock line 133 , and commands CMD are signaled over a plurality of command signal lines 134 . The memory modules 125 , 126 include a plurality of memory devices 136 - 139 , 136 ′- 139 ′ and a register 141 , 141 ′, respectively. Each memory device 136 - 139 , 136 ′- 139 ′ may be a high speed synchronous memory device. Although only two memory modules 125 , 126 and associated signal lines 129 - 129 c , 130 - 130 c are shown in FIG. 5, it should be noted that any number of memory modules can be used.
[0040] The plurality of signal lines 129 - 129 c , 130 - 130 c , 132 , 133 , 134 which couple the memory modules 125 , 126 to the memory controller 124 are known as the memory bus 143 . The memory bus 143 may have additional signal lines which are well known in the art, for example chip select lines, which are not illustrated for simplicity. Each column of memory devices 136 - 139 , 136 ′- 139 ′ spanning the memory bus 143 is known as a rank of memory. Generally, single side memory modules, such as the ones illustrated in FIG. 4, contain a single rank of memory. However, double sided memory modules containing two ranks of memory may also be used.
[0041] Read data is output serially synchronized to the clock signal CLK, which is driven across a plurality of clock signal lines, 130 , 130 a , 130 b , 130 c . Write data is input serially synchronized to the clock signal CLK, which is driven across the plurality of clock signal lines 130 , 130 a , 130 b , 130 c by the memory controller 124 . Commands and addresses are also clocked using the clock signal CLK which is driven by the memory controller 124 across the registers 141 , 141 ′ of the memory modules 125 , 126 , respectively, to a terminator 148 . The command, address, and clock signal lines 134 , 132 , 133 , respectively, are directly coupled to the registers 141 , 141 ′ of the memory modules 125 , 126 , respectively. The registers 141 , 141 ′ buffer those signals before they are distributed to the memory devices 136 - 139 , 136 ′- 139 ′ of the memory modules 125 , 126 , respectively.
[0042] While the present invention has been described in conjunction with preferred embodiments thereof, those of ordinary skill in the art will recognize that many modifications and variations are possible. Such modifications and variations fall within the scope of the present invention which is limited only by the following claims. | A memory device is comprised of a plurality of arrays of memory cells and peripheral devices for reading information out of and for writing information into the memory cells. The peripheral devices include a decode circuit responsive to a first portion of address information for identifying an address and is further responsive to a second portion of the address information for identifying an order. The address may be a read address or a write address, and the order may be the order for reading data or writing data, respectively. The peripheral devices may also include a read sequencer circuit or both a write sequencer circuit and a read sequencer circuit for reordering bits to be read or written, as the case may be, in response to another portion of the address information. The necessary address information is routed to the sequencer circuits by an address sequencer. Methods of operating such a memory device are also disclosed. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This claims the benefit under 35 U.S.C. §119(e) to U.S. Provisional Application Serial No. 60/262,899, filed Jan. 19, 2001. This is also a continuation-in-part of U.S. Ser. No. 09/518,365, filed Mar. 3, 2000, which is a continuation of U.S. Pat. No. 6,056,059, which is a continuation-in-part of U.S. Pat. No. 5,944,107, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Nos. 60/013,227, filed Mar. 11, 1996, 60/025,033, filed Aug. 27, 1996, and 60/022,781, filed Jul. 30, 1996, all hereby incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates generally to subsurface tools used in the completion of subterranean wells and, more particularly, provides an apparatus and method for use in multilateral completions.
BACKGROUND
[0003] Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, such as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore has been drilled, the well must be completed before hydrocarbons can be produced from the well. A completion involves the design, selection, and installation of equipment and materials in or around the wellbore for conveying, pumping, or controlling the production or injection of fluids. After the well has been completed, the production of oil and gas can begin.
[0004] It is increasingly commonplace within the industry to drill and complete multilateral wells. These are wells that contain one or more lateral wellbores that extend out from a main wellbore running to the earth's surface. These lateral wellbores can increase the production capacity and ultimate recovery from a single productive formation, or may allow multiple reservoirs to be depleted from a single well. This is particularly true when drilling from an offshore platform where multiple wells must be drilled to cover the great expenses of offshore drilling.
[0005] Standard completion practices are to complete the lateral wellbores separately. This requires separate trips into the well to perform the completion operations, with each trip resulting in significant costs of money and time.
[0006] There is a need for apparatus and methods to reduce the time and expense of completing multilateral wells.
SUMMARY OF THE INVENTION
[0007] In general, according to an embodiment, a downhole assembly comprises a casing junction assembly adapted to be installed at a junction of plural wellbores, the casing junction assembly defining plural outlets to respective plural lateral wellbores, and the casing junction assembly having an integrated diverter providing plural guide surfaces proximate corresponding outlets.
[0008] A method of completing a well at a junction of plural wellbores comprises providing a casing junction assembly having plural outlets for establishing communication with respective plural wellbores, and providing a diverter integrated with the casing assembly, with the diverter having plural guide surfaces. A tool having plural conduits is engaged with the casing junction assembly, and the conduits are guided into respective outlets with the plural guide surfaces.
[0009] Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a schematic of an example embodiment of a casing assembly installed in a multilateral well.
[0011] FIGS. 2 - 4 show further completion of the multilateral well of FIG. 1.
[0012] [0012]FIG. 5 shows an alternate embodiment of the invention.
[0013] FIGS. 6 - 10 show longitudinal and cross section illustrations of various embodiments of the present invention.
[0014] FIGS. 11 - 13 show alternate embodiments of the present invention within a multilateral well.
[0015] FIGS. 14 - 15 show section views of an embodiment of the casing junction.
[0016] FIGS. 16 - 22 show an alternate embodiment of a landing tool.
[0017] [0017]FIG. 23 shows an alternate embodiment of the present invention.
[0018] FIGS. 24 - 25 show another longitudinal section view of the landing tool illustrated in FIGS. 16 - 22 .
DETAILED DESCRIPTION
[0019] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
[0020] As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
[0021] Referring to FIG. 1, a multilateral well, shown generally as 10 , includes a main wellbore 12 that is drilled into a subterranean zone 14 . The main wellbore 12 is stabilized by inserting a string of casing 20 that is cemented 22 in place. The casing 20 may include a casing junction assembly 28 , which may be cemented in place concurrently with the remainder of the casing 20 . A first lateral wellbore 16 and a second lateral wellbore 18 are shown that have been drilled from the main wellbore 12 and from the casing junction 28 assembly. The lateral wellbores may have smaller diameters than the main wellbore. However, that is not necessarily the case in other embodiments. The casing junction assembly 28 thus completes a junction of plural wellbores. As used here, the term “wellbore” or “bore” refers to either a main wellbore or a lateral wellbore.
[0022] [0022]FIG. 2 shows a multilateral well 10 having a casing junction assembly 28 set within the main wellbore 12 and other junction equipment installed in the casing junction assembly 28 . The casing junction assembly 28 provides the connection of the main wellbore 12 and the lateral wellbores 16 , 18 . The casing junction assembly 28 is attached to the remainder of the casing 20 and run into the well and cemented with the remainder of the casing 20 (cement layer shown at 22 ). The casing junction 28 can be run into the well in a collapsed or collapsed configuration and expanded to its final configuration prior to being cemented in place, as described in U.S. Pat. No. 6,283,216, which application is incorporated herein by reference.
[0023] The lateral wellbores 16 and 18 are drilled after the casing 20 and the casing junction 28 are cemented in place. Once a lateral wellbore is drilled, a liner 96 , 98 can be run into the lateral wellbore 16 , 18 and set in place with a packer type device, also known as a liner hanger. Packers 24 , 26 attached to liners 96 , 98 are shown located within the first and second branch legs 15 , 17 of the casing junction assembly 28 . In alternative embodiments, the packers 24 , 26 can be set directly within the first and second lateral wellbores 16 , 18 . The first and second legs 15 , 17 are aligned to communicate with the first and second lateral wellbores 16 , 18 .
[0024] The casing junction assembly 28 includes a first guide surface 30 that serves to deflect items towards the first leg 15 and the first lateral wellbore 16 , and a second guide surface 32 that serves to deflect items towards the second leg 17 and the second lateral wellbore 18 . The casing junction assembly 28 shown also includes a projection 34 that extends upwardly. The first guide surface 30 , second guide surface 32 , and projection 34 are part of a diverter 68 . Since the casing junction assembly 28 can be symmetrical in shape and includes the diverter 68 , a separate tool, such as a typical whipstock, is not needed to deflect a tubing string into each of the legs and lateral wellbores. The packers 24 , 26 include polished bore receptacles 36 , 38 and are located above the zones to be produced.
[0025] The diverter 68 is an “integrated” diverter; that is, it is part of the casing junction assembly 28 , as contrasted with a diverter that is run in separately for engagement with the casing junction assembly 28 . The diverter 68 can either be integrally formed with the casing junction assembly 28 , or the diverter 68 can be affixed permanently to the casing junction assembly 28 by an attachment mechanism. The diverter is integrated in the sense that it is part of the casing junction assembly 28 when the casing junction assembly 28 is installed at the junction to be completed.
[0026] Referring to FIG. 3, an embodiment of the invention where a landing tool 40 is placed within the main wellbore 12 is shown. After the casing 20 and the casing junction assembly 28 have been cemented in place, the lateral wellbores 16 , 18 are drilled and the first and second packers 24 , 26 are set in place within the first and second legs 15 , 17 , respectively. An assembly including a landing tool 40 , a first tubing string 42 , and a second tubing string 44 may be connected to a deployment string 500 and inserted into the main wellbore 12 . The first tubing string 42 includes a seal assembly 48 , extends from the landing tool 40 , and is generally aligned with the first leg 15 and first lateral wellbore 16 . The second tubing string 44 includes a seal assembly 50 , extends from the landing tool 40 , and is generally aligned with the second leg 17 and the second lateral wellbore 18 . The landing tool 40 is lowered into the well casing 20 and is aligned with respect to the lateral wellbores in a manner discussed below. Once the landing tool 40 is set and locked in place, a weight may be placed down on the deployment string 500 to simultaneously extend the tubing strings 42 , 44 out from the landing tool 40 to enter the first and second legs 15 , 17 and engage in the polished bore receptacles 36 , 38 of respective packers 24 , 26 .
[0027] Although the Figures show that the landing tool 40 is set and locked in place within the casing junction assembly 28 , the landing tool 40 may be set and locked in place in the casing 20 above the casing junction assembly 28 in other embodiments.
[0028] In one embodiment, the deployment string 500 can then be disconnected from the landing tool 40 and removed to the earth's surface. In this embodiment, the remaining completion equipment is deployed in another downhole trip, resulting in two trips being performed to complete the well. In an alternative embodiment, the deployment string 500 comprises permanent completion tubings and/or components that remain downhole after the extension of the tubing strings 42 , 44 . Thus, in this alternative embodiment, only one trip is required to complete the well.
[0029] The landing tool 40 is fixed in place by a setting element 66 that restricts any longitudinal or rotational movement of the landing tool 40 . The setting element 66 includes slips that extend out to engage the inner wall of the casing junction assembly 28 (see FIG. 5) or casing 20 . Other forms of the setting element 66 , such as locking elements/dogs 200 (see FIGS. 16 - 22 ), can be used in other embodiments. The setting element 66 (or locking elements/dogs 200 ) are examples of landing elements engageable with landing profiles at the junction.
[0030] Once the landing tool 40 is correctly oriented in relation to the lateral wellbores 16 , 18 , the landing tool 40 is then locked in position by the setting element 66 . The setting element 66 is engaged by exerting a downward force onto the tool that breaks a shear element and extends slips to engage with the casing junction 28 or casing 20 .
[0031] After the tool is locked in place by the setting element 66 , a further downward force can be exerted onto the tool that will break yet another shear element and will enable the extension of the tubing strings, as shown in FIG. 4. As the tubing strings 42 , 44 extend from the landing tool 40 , the diverter 68 deflects each of the tubing strings 42 , 44 into its respective casing junction leg 15 , 17 . Specifically, as the first tubing string 40 extends from the landing tool 40 , it contacts first guide surface 30 . First guide surface 30 then serves to guide the first tubing string 40 towards the first leg 15 . Concurrently, as the second tubing string 42 extends from the landing tool 40 , it contacts second guide surface 32 . Second guide surface 32 then serves to guide the second tubing string 42 towards the second leg 17 . The first tubing string 42 and the second tubing string 44 proceed until they seat in their respective polished bore receptacles 36 , 38 . The diverter 68 is located between the two tubing strings 42 , 44 , thus preventing them from both going into a single leg or lateral wellbore. It is noted that the tubing strings 42 , 44 can be connected in some way, such as by a pin or strap that can be broken as the tubing strings are deflected away from each other by the diverter 68 .
[0032] As shown in FIG. 23, the tubing strings 42 , 44 can be constructed in a manner so as to be biased away from each other when not connected. The tubing strings 42 , 44 can be connected, such as by a pin or strap 201 . In this way, when the connection 201 is broken as shown by the dashed lines in FIG. 23, the tubing strings 42 , 44 naturally deflect from each other based on the bias to facilitate the separation and insertion of the tubing strings into the legs 15 , 17 . The connection 201 can be broken into parts 202 , 203 , such as by the separation induced by the diverter 68 . In this embodiment, the diverter 68 cooperates with the biasing of the tubing strings 42 , 44 to induce deflection of the tubing strings into the lateral wellbores 16 , 18 .
[0033] In the embodiment shown in FIG. 4, the deployment string 500 is removed and dual production tubing strings 52 , 54 are run into the main wellbore 12 and attached to the landing tool 40 so as to establish fluid communication with the first and second tubing strings 42 , 44 , respectively. In an alternative embodiment, the deployment string 500 includes the dual production tubing strings 52 , 54 and so the landing tool 40 is run downhole together with the dual production tubing strings 52 , 54 .
[0034] In the discussion above, the landing tool 40 is described as being capable of orienting the string, setting the string within the casing, and also extending the tubing strings. These different operations can be separated from each other and performed by two or more separate tools. For example, a completion assembly may include three separate tools: one tool used for orienting the completion assembly, a second tool used to set the completion assembly within the casing to prevent any longitudinal or rotational movement, and a third tool used to extend the tubing strings through the junction and into their respective lateral wellbore. This description is not meant to limit the manner in which these operations can be performed.
[0035] [0035]FIG. 5 illustrates an alternate embodiment where a single production tubing string 56 is used, instead of the dual tubings 52 , 54 as shown in FIG. 4. In one embodiment, a swivel 58 is connected between the tubing 56 and a wireline reentry tool 60 , which has two relatively short sections of production tubing or “tubing subs” 62 , 64 for engagement with the landing tool 40 and the tubing strings 42 , 44 . In this embodiment, the wireline reentry tool 60 is deployed after the retrieval of the deployment string 500 . In another embodiment, the deployment string 500 includes a Y-block mechanism connected at its bottom to the dual production tubing strings 52 , 54 and at its top to the single production tubing string 56 . In this embodiment, the deployment string 500 is not retrieved after the landing tool 40 is set.
[0036] If it is desired pull the landing tool 40 and tubing strings 42 , 44 out of the well 10 , the tubing strings 42 , 44 can be withdrawn from the packers 24 , 26 and pulled back into their pre-extended configuration. An upward force can then be exerted on the landing tool 40 by pulling on the deployment string 500 until yet another shear element is broken, which causes the setting element 66 to retract and release the landing tool 40 to be pulled out of the well 10 .
[0037] Referring to FIGS. 6 and 7, the landing tool 40 according to one embodiment includes a body 80 and an orienting key 82 that is biased outwardly, for example, by one or more springs 84 . The orienting key 82 is disposed within a first recess 86 in the body 80 . The orienting key 82 is capable of radial movement within the first recess 86 . A locking key 88 is movably secured to the body 80 , and is biased outwardly, for example by a leaf spring 92 , which may be secured to the locking key 88 . The locking key 88 can be disposed within a second recess 94 in the body 80 and is coupled to the body 80 by a hinge pin 96 , for example.
[0038] [0038]FIG. 8 shows an illustration of the casing 20 or casing junction assembly 28 (recall that the landing tool 40 may be set either in the casing junction assembly 28 or in the casing 20 above the casing junction assembly 28 ) in a particular embodiment of the apparatus. The casing 20 or casing junction assembly 28 includes an orienting slot 70 , a locking slot 72 and an orienting profile 74 that can be used in conjunction with the landing tool 40 (FIGS. 6 and 7). The profile 74 , orienting slot 70 and locking slot 72 may be formed as part of the well casing 20 or casing junction 28 , or as a separate component (sometimes called a “muleshoe” or a “discriminator” 76 ), that is attached to the casing 20 /casing junction assembly 28 .
[0039] [0039]FIGS. 9 and 10 illustrate the landing tool 40 engaged within the well casing 20 /casing junction assembly 28 . As the landing tool 40 is inserted into the well casing 20 /casing junction assembly 28 , a lower edge 83 of the orienting key 82 (FIG. 6) contacts the profile 74 (FIG. 8). Continued downward movement of the landing tool 40 causes the orienting key 82 to move along the profile 74 and into engagement with the orienting slot 70 , thereby rotating the landing tool 40 , and any attached items, into alignment with the diverter 28 and the first and second lateral wellbores 16 , 18 (FIGS. 3 and 4). The lower edge 83 of the orienting key contacts a lower ledge 71 of the orienting slot 70 , which restricts any further downward movement. As the orienting key 82 moves into the orienting slot 70 , the locking key 88 is longitudinally and radially aligned with the locking slot 72 . As the lower edge 83 of the orienting key bottoms out on the lower ledge 71 of the orienting slot 70 , the locking key 88 will be moved into the locking slot 72 under force from the locking key spring 92 . Any upward movement is then prevented by contact of the upper edge 89 of the locking key 88 with the upper edge 73 of the locking slot 72 .
[0040] [0040]FIG. 11 shows a multilateral well 10 having packers 24 , 26 located within the first and second lateral wellbores 16 , 18 . A diverter 168 , which is a part of the casing junction assembly 28 , is shown set within the main wellbore 12 proximal the junction of the main wellbore 12 and the lateral wellbores 16 , 18 . The diverter 168 can be positioned within the well in numerous ways. For example, the diverter 168 can be retrievably set in a manner such as a packer, the diverter 168 can be cemented in place, or the diverter 168 can be included as an integral part of the casing 20 . The diverter 168 has a first guide surface 130 that serves to deflect items towards the first lateral wellbore 16 , and a second guide surface 132 that serves to deflect items towards the second lateral wellbore 18 . The diverter 168 shown also includes a projection 134 that extends upwardly from the diverter 168 . The packers 24 , 26 include polished bore receptacles 36 , 38 and are located above the zones to be produced.
[0041] Referring to FIG. 12, another embodiment is shown. After the casing 20 has been cemented in place, first and second packers 324 , 326 are set in place within the lateral wellbores 16 , 18 , respectively. An assembly including a landing tool 340 , a first tubing string 342 and a second tubing string 344 is connected to a deployment string (not shown) and inserted into the main wellbore 12 . The first tubing string 342 includes a seal assembly 348 , extends from the landing tool 340 , and is aligned with the first guide surface 330 of a diverter 368 . The second tubing string 344 includes a seal assembly 250 , extends from the landing tool 340 , and is aligned with the second guide surface 332 . The first lateral wellbore 16 contains a first packer 324 having a receptacle 336 and a sand screen assembly 346 . The second lateral wellbore 18 contains a second packer 326 having a receptacle 338 and a sand screen assembly 348 . The landing tool 340 is lowered into the well casing 20 and is aligned with respect to the lateral wellbores. Once the landing tool 340 is set in place, a weight may be placed down on the deployment string (not shown) to simultaneously extend the tubing strings 342 , 344 out from the landing tool 340 to contact the diverter 368 . The extended tubing strings enter the lateral wellbores 16 , 18 and engage with their respective packers 324 , 326 . The deployment string (not shown) can then be disconnected from the landing tool 340 and removed to the earth's surface.
[0042] [0042]FIG. 13 shows yet another embodiment. A landing tool 440 is fixed in place by a setting element 466 that restricts any longitudinal or rotational movement of the landing tool 440 . A first tubing string 442 and second tubing string 444 extend from the landing tool 440 . The first tubing string 442 is separated from the second tubing string 444 by the projection 434 . The first tubing string 442 is deflected by the first guide surface 430 into the first lateral wellbore 16 where it seats in the receptacle 436 of a first packer 424 . The second tubing string 444 is deflected by a second guide surface 432 into the second lateral wellbore 18 until it seats in a receptacle 438 of a second packer 426 .
[0043] Phrases such as “separation of tubing strings by a diverter projection” are meant to mean that the diverter projection is located between the two tubing strings thus restricting them from both going into a single lateral wellbore and aligning them in respect to the applicable guide surface. The phrase is not meant to imply a physical attachment between them that is being broken, although that is possible. In the embodiment of FIG. 13, the deployment string (not shown) has been removed and dual production tubings 452 , 454 have been run into the main wellbore 12 and attached to the landing tool 440 , so as to establish fluid communication with the first and second tubing strings 442 , 444 , respectively.
[0044] [0044]FIG. 14 is an overhead view of an embodiment of the casing junction assembly 28 . The two legs 15 , 17 that form the starting point of lateral wellbores 16 and 18 are shown as cylindrical tubes. The projection 34 having guide surfaces 30 , 32 is located between the two legs 15 , 17 .
[0045] [0045]FIG. 15 is a longitudinal sectional side view of the casing junction assembly of FIG. 14. The legs 15 , 17 can be seen to project outward to provide communication to the lateral wellbores 16 and 18 . The projection 34 is shown to extend above the openings of the lateral legs 15 , 17 . The diverter 68 portion of this embodiment is shown to be between the two legs 15 , 17 . The guide surfaces 30 , 32 are shown sloping towards the respective lateral wellbore.
[0046] FIGS. 16 - 22 illustrate one embodiment of the landing tool 40 in greater detail. Similar to the landing tool 40 depicted in FIGS. 6 and 7, the landing tool 40 of this embodiment includes a body 80 ′ (FIG. 16B) and at least one orienting key 82 ′ that is biased outwardly, for example, by one or more leaf springs 84 ′. The orienting key 82 ′ is disposed within a first recess 86 ′ in the body 80 ′. The orienting key 82 ′ is held within the first recess 86 ′ by at least one retainer 301 and is capable of radial movement within the first recess 86 ′. The orienting mechanism of this embodiment functions in the same manner as the orienting mechanism of the landing tool 40 embodiment depicted in FIGS. 6 - 9 .
[0047] The landing tool 40 of FIGS. 16 - 22 further includes at least one locking element 200 (similar to setting element 66 of FIGS. 3 and 4) movably secured to the body 80 ′. The body 80 ′ can include a plurality of locking elements 200 , each element 200 biased outwardly by one or more springs 202 and held within corresponding one or more second recesses 204 by at least one retainer 303
[0048] The body 80 ′ may include a first body part 206 and a second body part 208 that may slide in relation to each other. In one embodiment, the orienting key 82 ′ is located on the first body part 206 , and the locking elements 200 are located on the second body part 208 . First body part 206 includes at least one protruding element 210 , such as at least one finger, extending from its bottom portion. Protruding element 210 may also be a sleeve in other embodiments. The fingers 210 may or may not be integral with the remainder of the first body part 206 . Each finger 210 is housed and can slide in a slot 212 formed on the second body part 208 . Each second recess 204 is part of a slot 212 . The fingers 210 , the slots 212 , the locking elements 200 , and the second recess 204 are constructed so that each finger 210 can slide into a second recess 204 and next to a locking element 200 , thereby preventing further radial movement of such locking element 200 .
[0049] Body 80 ′ further includes two passages 300 (FIG. 20B) therethrough. Note that the longitudinal sectional view of FIGS. 20 A- 20 C is taken along a plane perpendicular to that of the longitudinal sectional view of FIGS. 16 A- 16 C. Dual production tubing strings 52 , 54 may be passed through the passages 300 . The production tubing strings 52 , 54 are attached to the first and second tubing strings 42 , 44 . In the embodiment shown in FIGS. 20 A- 20 C, the production tubing strings 52 , 54 are attached to the first and second tubing strings 42 , 44 within the passages 300 .
[0050] FIGS. 16 A-C show the landing tool 40 in its run or deployment position. In this position, the fingers 210 are not abutting the locking elements 200 and are instead located above the locking elements 200 within their respective slots 212 . The first body part 206 and the second body part 208 are attached to each other in this configuration by way of shear pins, such as first shear pins 214 shown in FIG. 21. As the landing tool 40 is run downhole, the orienting key 82 ′ interacts with a matching orienting slot (not shown but similar to orienting slot 70 ) to orient the landing tool 40 within the casing 20 or casing junction 28 , as previously discussed. As the orienting key 82 ′ comes to its final position in the orienting slot, each locking element 200 becomes longitudinally and radially aligned with a matching locking slot 72 ′ (similar to locking slot 72 , albeit different in shape) and the springs 202 bias the locking elements 200 into the locking slots 72 ′. The locking slots 72 ′ and locking elements 200 include mating straight surfaces 216 that prevent further downward movement of the landing tool 40 . At this point, the landing tool 40 is landed within the locking slots 72 ′ and is appropriately oriented.
[0051] FIGS. 17 A- 17 C show the landing tool 40 locked in position to prevent inadvertent longitudinal motion. To lock the landing tool 40 in place, a downward force is exerted on the landing tool 40 by way of dual production tubing strings 52 , 54 , for example. If high enough, the downward force acts to shear the first shear pins 214 and allows the downward motion of the first body part 206 in relation to the second body part 208 . It is noted that the second body part 208 remains stationary due to its engagement with the locking slots 72 ′ by way of locking elements 200 . As the first body part 206 slides, the fingers 210 become wedged next to the locking elements 200 , thereby preventing any radial inward movement of the locking elements 200 and thus effectively locking the second body part 208 in place. In addition, once the first body part 206 slides a sufficient distance, openings 222 on the second body part 208 become aligned with openings 224 on the fingers 210 to allow locking pins 220 that are spring loaded within the openings 222 to be biased partially into the openings 224 . Once the locking pins 220 are located within the openings 222 , 224 , the locking pins 220 lock the first and second body parts 206 , 208 together.
[0052] FIGS. 18 A-D show the landing tool 40 with the first and second tubing strings 42 , 44 extended in the direction of the first and second lateral wellbores. For purposes of clarity, the landing tool 40 of this embodiment is shown without placement in a main wellbore including lateral wellbores. To extend the first and second tubing strings 42 , 44 , a downward force is exerted on the landing tool 40 by way of the dual production tubing strings 52 , 54 , for example. If high enough, the downward force acts to shear a set of second shear pins 218 (see FIGS. 20B and 22) that attach the first and second tubing strings 42 , 44 (or the dual production tubing strings 52 , 54 ) to the body 80 ′ (and more particularly to the first body part 206 ). Once the second shear pins 218 are sheared, the first and second tubing strings 42 , 44 can be extended within/through passages 300 and out of landing tool 40 . As previously discussed, the first and second tubing strings 42 , 44 are then guided in the direction of the first and second lateral wellbores by the diverter 68 .
[0053] As best seen in FIG. 20C, the lower end of each of the first and second tubing strings 42 , 44 may include an inclined surface 302 . The inclined surface 302 cooperates with the diverter 68 to more easily facilitate the extension and diversion of the first and second tubing strings 42 , 44 into the first and second legs 15 , 17 .
[0054] FIGS. 19 A- 19 C show the landing tool 40 in its unset and retrieval position. Once the operator is ready to retrieve the landing tool 40 , an upward force is exerted on the landing tool 40 by way of the dual production tubing strings 52 , 54 , for example. If high enough, the upward force acts to shear the locking pins 220 (compare FIGS. 18B and 19B) that attach the first and second body parts 206 , 208 . Once the locking pins 220 are sheared, continued upward force on the dual production tubing strings 52 , 54 acts to pick up first body part 206 by way of internal shoulder 226 (FIG. 20B). As the first body part 206 slides in relation to the second body part 208 (which is still locked in place), the fingers 210 slide out of abutment with the locking elements 200 , thereby allowing the locking elements 200 to be biased radially both inwardly and outwardly.
[0055] As the first body part 206 continues to be pulled upward, the first body part 206 eventually picks up and supports the second body part 208 . FIGS. 24 and 25 show a longitudinal cross-sectional view of the landing tool 40 shown in FIGS. 16 - 22 taken along a different phase of the body 80 ′. FIG. 24 shows the tool 40 in the deployment position, and FIG. 25 shows the tool 40 in the retrieval configurations. As can be seen in the Figures, first body part 206 includes at least one radial slot 500 therein, and second body part 208 includes a pin 502 slidingly disposed within each slot 500 . Each pin 502 is securely attached to the second body part 208 . When the landing tool 40 is in the deployment position (FIG. 24), the pin 502 is proximate the upper end 504 of the slot 500 . As the first body part 206 is pulled up during retrieval (FIG. 25), the lower end 506 of the slot 500 eventually abuts and picks up its corresponding pin 502 , thereby also picking up the second body part 208 .
[0056] With the slots and pins 500 , 502 providing a secure connection between the first and second body parts 206 , 208 , continued upward movement of the first body part 206 retrieves the second body part 208 and the first and second tubing strings 42 , 44 from the wellbore. Due to the mating angles of the locking element 200 and locking slots 72 ′ and because the locking element 200 can now be biased within second recess 204 , the connection between the locking elements 200 and the locking slots 72 ′ does not prevent upward movement of the landing tool 40 .
[0057] In addition, the upward movement of the first body part 206 (during the initial retrieval process) results in the mating of a teeth profile 228 (FIG. 19B) located on an inner surface 230 of each finger 210 with a teeth profile 232 located on ratchet keys 234 . The ratchet keys 234 are located within grooves 236 on second body part 208 and are biased outwardly by springs 236 , for instance. The mating teeth profiles 228 , 232 are designed so that they do not allow relative motion in the downward direction, but allow relative motion in the upward direction. This is desirable so that, if the landing tool 40 becomes stuck in the wellbore as it is being retrieved, an operator may push and/or pull on the relevant retrieving tool/string without fear of inadvertently locking the locking elements 200 and the landing tool 40 within the wellbore once again. In this manner, regardless of the direction of the jarring force exerted by the operator, the mating teeth 228 , 232 prevent the fingers 210 from sliding downwardly and wedging against the locking elements 200 (and thereby locking the locking elements 200 ).
[0058] It is noted that in the run-in position (FIG. 16B), the ratchet keys 234 are covered by a sleeve 238 , which is secured to the second body part 208 by way of a set of shear pins 240 . As the fingers 210 slide down to lock the landing tool 40 in place (FIG. 17B), the fingers 210 push the sleeve 238 downwardly, shearing the shear pins 240 , and uncovering the ratchet keys 234 .
[0059] It is noted that the shear pins used in the landing tool 40 should be rated to enable the sequence previously described. Thus, for instance, the first set of shear pins 214 are rated lower than the second set of shear pins 218 .
[0060] The discussion and illustrations within this application refer to a vertical main wellbore that has casing cemented in place. The present invention can also be utilized to complete wells that are not cased entirely and likewise to wells that contain main wellbores that have an orientation that is deviated from vertical.
[0061] The particular embodiments disclosed herein are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction, operation, materials of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. | A method and apparatus for completing a junction of plural wellbores includes providing a casing junction assembly having plural outlets for communicating with corresponding wellbores. A tool has plural extendable conduits for engaging in the outlets. The casing junction assembly has an integral diverter with guiding surfaces to guide the conduits into the outlets. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Application Ser. No. 08/876,120, filed Jun. 13, 1997, incorporated by reference herein. This application also claims priority to U.S. Provisional Application Ser. No. 60/065,577, filed Nov. 12, 1997, U.S. Provisional Application Ser. No. 60/085,786, filed May 18, 1998, and U.S. Provisional Application Ser. No. 60/090,164, filed Jun. 22, 1998, all of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] Molecular chirality plays an important role in science and technology. The biological activities of many pharmaceuticals, fragrances, food additives and agrochemicals are often associated with their absolute molecular configuration. While one enantiomer gives a desired biological function through interactions with natural binding sites, another enantiomer usually does not have the same function and sometimes has deleterious side effects.
[0003] A growing demand in pharmaceutical industries is to market a chiral drug in enantiomerically pure form. To meet this fascinating challenge, chemists have explored many approaches for acquiring enantiomerically pure compounds ranging from optical resolution and structural modification of naturally occurring chiral substances to asymmetric catalysis using synthetic chiral catalysts and enzymes. Among these methods, asymmetric catalysis is perhaps the most efficient because a small amount of a chiral catalyst can be used to produce a large quantity of a chiral target molecule. During the last several decades, great attention has been devoted to discovering new asymmetric catalysts and more than a half-dozen commercial industrial processes have used asymmetric catalysis as the key step in the production of enantiomerically pure compounds. The worldwide sales of chiral drugs in 1997 was nearly S90 billion.
[0004] Many chiral phosphines (as shown in FIG. 1) have been made to facilitate asymmetric reactions. Among these ligands, BINAP is one of the most frequently used bidentate chiral phosphines. The axially dissymmetric, fully aromatic BINAP ligand has been demonstrated to be effective for many asymmetric reactions. DUPHOS and related ligands have also shown impressive enantioselectivities in numerous reactions. However, there are many disadvantages associated with these ligands which hinder their applications.
[0005] These phosphines are difficult to make and some of them are air sensitive. For DIPAMP, the phosphine chiral center is difficult to make. This ligand is only useful for limited application in assymmetric hydrogenation. For BPPM, DIOP, and Skewphos, the methylene group in the ligands causes conformational flexibility and enantioselectivities are moderate for many catalytic asymmetric reactions. DEGPHOS and CHIRAPHOS coordinate transition metals in five-membered rings. The chiral environment created by the phenyl groups is not close to the substrates and enantioselectivities are moderate for many reactions.
[0006] BINAP, DuPhos, and BPE ligands are good for many asymmetric reactions. However, the-rotation of the aryl-aryl bond makes BINAP very flexible. The flexibility is an inherent limitation in the use of a phosphine ligand. Furthermore, because the phosphine of BINAP contains three adjacent aryl groups, it is less electron donating than a phosphine that has less aryl groups. This is an important factor which influences reaction rates. For hydrogenation reactions, electron donating phosphines are more active. For the more electron donating DUPHOS and PBE ligands, the five-membered ring adjacent to the phosphines is flexible.
[0007] In co-pending application Ser. No. 08/876,120, the inventors herein disclosed, inter alia, the (2,2′)-bis(diorganophosphino)-(1,1′)-bis(cyclic) family of chiral ligands, the (2,2′)-bis(diorganophosphinoxy)-(1,1′)-bis(cyclic) family of chiral ligands, and the family of chiral ligands comprising a rigid, fused phosphabicyclo[2.2.1]heptane structure named PennPhos, after Penn State University where the ligand was created. The common feature of these ligands is that they contain rigid ring structures which restrict conformational flexibility and promote efficient chiral transfer from the rigid ligand to desired products.
SUMMARY OF THE INVENTION
[0008] An object of the invention is to provide new chiral ligands.
[0009] A further object of the invention is to provide a detailed synthetic plan for making chiral ligands.
[0010] A further object of the invention is to provide methods of carrying out asymmetric synthesis using the chiral phosphine ligands of the present invention.
[0011] A further object of the invention is to provide methods for the efficient asymmetric synthesis of alcohols by enantioselective hydrogenation of ketones catalyzed by the chiral ligands of the invention.
[0012] A further object of the invention is to provide methods of using selected additives to improve the yield and enantioselectivity of selected asymmetric reactions.
[0013] Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0014] To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a chiral bisphosphinite ligand having restricted conformational flexibility, wherein said ligand comprises an enantiomer of a substituted or unsubstituted (2,2′)-bis(diarylphosphinoxy)-(1,1′)-dicyclo compound having saturated carbons at the 2,2′, 1, and 1′ positions.
[0015] Exemplary embodiments of said ligand include (2S, 2′S)-bis (diphenylphosphinoxy)-(1R, 1R′)-dicyclopentane and (2R, 2′R)-bis (diphenylphosphinoxy)-(1R, 1R′)-dicyclopentane. These ligands are sometimes referred to herein as (S, S′) BICPO, and (R, R′) BICPO, respectively, or simply as BICPO.
[0016] The invention also comprises a chiral bisphosphine ligand for performing asymmetric synthesis, wherein said ligand is an enantiomer of a (2, 2′)-bis (diarylphosphino)-(1, 1′)-dicyclo compound having saturated carbons at the 2, 2′, 1, and 1′ positions. In certain preferred embodiments, the ligand comprises an enantiomer of a (2, 2′)-bis(diarylphosphino)-(1, 1′)-dicyclo compound having saturated carbons at the 2, 2′, 1, and 1′ positions, and each aryl is 3, 5-alkyl substituted or 4-alkyl substituted. These ligands are sometimes referred to herein as modified BICP.
[0017] The invention comprises various methods for performing chiral synthesis using catalysts comprising the ligands disclosed in this application, and in the parent Application Ser. No. 08/876,120, including methods for synthesis of a chiral product in an enantiomeric excess from an organic substrate, comprising metal catalyzed asymmetric hydrogenation, wherein said asymmetric hydrogenation comprises the step of reacting an organic substrate in the presence of a catalyst, wherein the catalyst comprises a transition metal and a chiral ligand, and said chiral ligand comprises a phosphabicyclo[2.2.1] heptyl compound.
[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 shows prior art chiral ligands.
[0021] [0021]FIG. 2 shows a scheme for synthesis of the PennPhos Ligand.
[0022] [0022]FIG. 3 shows the BICPO ligand with contemplated phosphine groups.
[0023] [0023]FIG. 4 summarizes the results of asymmetric hydrogenation of various simple ketones with Rh-Me-PennPhos complexes.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The ligands of the present invention are generally used with transition metals. Specifically, transition metals known to be useful in organic synthesis are used. Examples of the transition metals used are the group VIII metals, such as rhodium, iridium, ruthenium, and nickel. More preferably, transition metal catalyst precursors are used in conjunction with the ligands to make a catalyst suitable for asymmetric synthesis. Suitable transition metal catalyst precursors include, but are not limited to, [Rh(COD)Cl] 2 , [Rh(COD) 2 ]X, or [Ir(COD)Cl] 2 , [Ir(COD) 2 ]X, or Ni(ally)X wherein X is BF 4 , CIO 4 , SbF 6 , CF 3 SO 3 , or equivalents, and COD is cyclooctadiene. The catalysts can be, for example, Ru(RCOO) 2 (diphosphine), RuX′2(diphosphine), where X′ is chlorine or bromine. Other group VII catalysts with chiral phosphines besides those mentioned above are known to those of skill in the art.
[0025] As used herein, enantiomeric excess refers to the excess of one enantiomer over another in the reaction product.
% enantiomeric excess = [ R ] - [ S ] [ R ] + [ S ] × 100
[0026] In general, the catalyst systems of the present invention produce chiral products with higher enantiomeric excess than in the prior art. In some instances, depending on the reaction involved, enantiomeric excess was found to be greater than about 70%. In still other cases, the enantiomeric excess of the product was greater than about 80%. The enantiomeric excess of still other reaction products has been found to be greater than about 90%, even approaching 100% enantiomeric excess in the case of some reactions disclosed herein.
[0027] BICP and BICPO
[0028] The BICP and BICPO ligands can be synthesized as set forth in co-pending application Ser. No. 08/876,120, with variations set forth below and with other variations as would be obvious to one of ordinary skill in the art.
[0029] One example of BICP is shown below in scheme (I). The scheme (I) below is exemplary only. The cycles of the bis(cyclic) structure may comprise alkyl and aryl substituents and may further contain fused substituents.
[0030] The synthesis of BICP is set forth under Section VI, “Experimental” below.
[0031] A modified variation of the BICP ligand comprises substituents on the diarylphosphinostructure. In one embodiment, the aryl substituent is 3,5-alkyl substituted or 4-alkyl substituted, as shown above in scheme I. In a preferred embodiment, the diarylphosphino structures are 3,5-dimethyl substituted, although other structures are possible, as would be apparent to one of ordinary skill in the art.
[0032] The chiral bisphosphinite ligand family (2S, 2′S)-bis(diarylphosphinoxy)-(1R, 1′R)-dicyclo compounds, and more particularly (2S, 2′S)-bis(diphenylphosphinoxy)-(1R, 1′R)dicyclopentane) (sometimes hereinafter referred to as “(1R, 1′R, 2S, 2′S)-BICPO” or simply “BICPO”) is easily made from chiral (1R,1′R)-bicyclopentyl-(2S, 2′S)-diol in high yield as illustrated below (scheme II):
[0033] In an advantageous modification, the BICPO ligand comprises diarylphosphine groups or diaryloxy phosphine groups in place of the diphenylphosphine groups shown above. As shown in Scheme 3, the ligand may comprise a biphenyl group having oxygens bonded at the 2 and 6′ positions, wherein a phosphorus in each diarylphosphinoxy group is bonded to said oxygens, and wherein the 3, 5, 3′, and 5′ positions of said biphenyl group are substituted with alkyl or alkoxy substituents. In a preferred embodiment, the 3, 5, 3′ and 5′ positions are substituted with methyl, tert-butyl or methoxy substituents. Biphenyl substituents with oxygens at the 2 and 6′ positions are known per se from U.S. Pat. No. 5,491,266, incorporated by reference herein.
[0034] Highly Enantioselective Rhodium-Catalyzed Hydrogenation of Dehydroamino Acids with Chiral Bisphosphinites
[0035] In contrast to many chiral phosphines reported in the literature, phosphinites used in metal complexes for asymmetric reactions are generally rather poor ligands. However, although phosphinites are less electron donating than phosphines, they can be excellent ligands for asymmetric hydroformylation and hydrocyanation reactions. Clearly, it is worthwhile to search for new chiral phosphinites for asymmetric catalysis. Taking advantage of the relatively rigid bis-cyclopentane backbone of BICP, we made the corresponding chiral bisphosphinite, (2S, 2′S)-bis(diphenylphosphinoxy)-(1R, 1′R)-dicyclopentane (abbreviated (1R, 1′R, 2S, 2′S)-BICPO). We have also synthesized (2R, 2′R)-bis(diphenylphosphinoxy)-(1R, 1′R)-dicyclopentane (abbreviated (1R, 1′R, 2R, 2′R)-BICPO. Rhodium complexes of these ligands are excellent catalysts for asymmetric hydrogenation of α-(acylamino)acrylic acids, giving up to 96% enantiomeric excess. These phosphinite ligands contain two cyclopentane rings which restrict their conformational flexibility, and high enantioselectivity in asymmetric hydrogenation can be achieved despite the formation of a nine-membered ring metal-ligand complex.
[0036] The cationic Rh(I)-complex [Rh(COD)(BICPO)]BF 4 , prepared in situ by mixing [Rh(COD) 2 ]BF 4 with 1.1 molar equivalents of (1R, 1′R, 2S, 2′S)-BICPO under an inert atmosphere, is a highly effective catalyst for the hydrogenation of α-acetoamidocinnamic acid at ambient temperature under 1 atmosphere of H 2 . Scheme III below was carried out at room temperature under 1 atm of hydrogen for 24 hours.
[0037] The ratio of substrate (0.5 mmol. 0.125 M):[Rh(COD) 2 ]BF 4 :ligand(1R, 1′R, 2S, 2′S BICPO) was equal to 1:0.01:0.011. The reaction mixture was treated with CH 2 N 2 , then concentrated in vacuo. The residue was passed through a short silica gel column to remove the catalyst. The enantiomeric excesses were measured by capillary GC or HPLC. The absolute configuration of products was determined by comparing the observed rotation with the reported value.
[0038] Table 1 summarizes the results of hydrogenation of α-acetoamidocinnamic acid under a variety of experimental conditions. The reaction medium significantly affects the catalyst activity and enantioselectivity of the product. Unlike our early observation on the additive effect of triethylamine with the BICP system, the enantioselectivity and reactivity of the hydrogenation decreased drastically in the presence of a catalytic amount of triethylamine (Rh:(1R, 1′R, 2S, 2′S)-BICPO]:Et 3 N=1:1.1:50). For example, α-acetoamidocinnamic acid was completely reduced with 89.1% enantiomeric excess in MeOH in the absence of Et 3 N while only 30% was reduced with 20.7% enantiomeric excess with a catalytic amount of Et 3 N under 1 atmosphere of H 2 (entry 3 vs 2 , entry 5 vs 4 ). Asymmetric hydrogenation in alcoholic solvents (entries 4 , 6 , and 8 - 9 ), except with CF 3 CH 2 OH (entry 7 ) gave better selectivities than in THF (entry 2 ) and CICH 2 CH 2 CI (entry 1 ). Among several common alcohol solvents, the highest enantioselectivity (94.7% enantiomeric excess, S) for the hydrogenation of α-acetoamidocinnamic acid was achieved in i PrOH under 1 atm of H 2 at ambient temperature (entry 9 ). The best result (96.1% enantiomeric excess, 100% conversion) for the hydrogenation of α-acetamidocinnamic acid was obtained when (1R, 1′R, 2S, 2′S)-BICPO was used in ′PrOH under 1 atmosphere of H 2 at 0° C. (entry 10 ). A neutral rhodium catalyst formed in situ from (1R, 1′R, 2S, 2′S) BICPO and [Rh(COD)CI] 2 is less effective than the cationic [Rh(COD) 2 ]BF 4 described above (entry 11 ).
TABLE 1 Rh-Catalyzed Asymmetric Hydrogenation of α-Acetamidocinnamic Acid Entry Solvent Et 3 N (%) Con. (%) ee (%) 1 ClCH 2 CH 2 Cl — 100 88.2 2 THF — 100 89.1 3 THF 50 30 30.9 4 MeOH — 100 92.4 5 MeOH 50 100 67.9 6 EtOH — 100 92.0 7 CF 3 CH 2 OH — 100 80.3 8 t BuOH — 100 91.1 9 1 PrOH — 100 94.7 10 c 1 PrOH — 100 96.1 11 d 1 PrOH — 86.6 63.9
[0039] Percent conversion and percent enantiomeric excess were determined by GC using a Chirasil-VAL III FSOT column on the corresponding methyl ester. The S absolute configuration was determined by comparing the optical rotation with the value reported in Burk, M. J., et al., J. Am. Chem. Soc. 1993, 115, 10125, incorporated herein by reference.
[0040] The absolute configurations at the 2, 2′-positions are opposite in (1R, 1′R, 2R, 2′R) BICP and (1R, 1′R, 2S, 2′S) BICPO, but in the asymmetric hydrogenation of α-acetoamidocinnamic acid, both gave the same amino acid: S-N-acetylphenylalanine. These results suggest that these reactions, promoted by a seven membered (1R, 1′R, 2R, 2′R)-BICP-Rh complex and a nine membered (1R, 1′R, 2S, 2′S)-BICPO-Rh complex, may proceed via different pathways. It is apparent that there must be careful matching of the catalyst chiral environment to the substrate in order to obtain high selectivity.
[0041] Using (1R, 1′R, 2R, 2′R)-BICPO as the ligand under the conditions that gave the best results for hydrogenation with (1R, 1′R, 2S, 2′S)-BICPO, α-acetoamidocinnamic acid was reduced completely to give (R)-N-acetylphenylalanine as the product with slightly lower enantioselectivity (83.51% enantiomeric excess).
[0042] Several dehydroamino acids were hydrogenated with the Rh-(1R, 1′R, 2S, 2′S)-BICPO catalyst according to the following general reaction:
[0043] The results are tabulated below in Table 2. High selectivity was achieved for the hydrogenation of α-(acetoamido) acrylic acid (94.8% enantiomeric excess, entry 1 in Table 2). Over 90% enantiomeric excesses have been obtained for many substituted a-acetoamidocinnamic acids. The enantioselectivity for the hydrogenation of dehydro-N-acetylleucine was lower than for other substrates (entry 11 in Table 2). The overall enantioselectivities are comparable or slightly lower than the enantioselectivities attained previously with the best chiral bisphosphines or bisphosphinites, which form five to seven-membered ring complexes with transition metals. However, compared with the nine-membered chelated bidentate ligands reported in the prior art our new bisphosphinites (1R, 1′R, 2S, 2′S) BICPO and (1R, 1′R, 2R, 2′R) BICPO display the highest reactivities and enantioselectivities in the rhodium-catalyzed asymmetric hydrogenation of α-(acylamino)acryic acids.
TABLE 2 Asymmetric Hydrogenations of Dehydroamino Acid Derivatives Entry Substrate % ee a 1 R = H, R′ = CH 3 94.8 2 R = Ph, R′ - CH 3 94.7 3 R = Ph, R′ = Ph 89.2 4 R = m-Br—Ph, R′ = CH 3 93.5 5 R = o-Cl—Ph, R′ = CH 3 92.9 6 R = p-F—Ph, R′ = CH 3 91.1 7 R = p-MeO—Ph, R′ = CH 3 93.2 b 8 R = p-OAc-m-OMePh, R′ = 95.0 b CH 3 9 R = 2-naphthyl, R′ = CH 3 91.4 10 R = 2-thienyl, R′ = CH 3 90.1 11 R = i-Pr, R′ = CH 3 45.7
[0044] The mechanism of asymmetric hydrogenation of dehydroamino acids has been examined intensively. It is generally accepted that a chiral ligand which can form a rigid ligand-metal complex is essential for effective chiral recognition. The presently disclosed new class of BICPO phosphinites, which form nine membered chelated complexes with rhodium, gave remarkably high selectivities for the hydrogenation of dehydroamino acids. The key element of this system is that the two cyclopentane rings in the backbone restrict the conformational flexibility of the nine-membered ring, and the four stereogenic carbon centers in the backbone dictate the orientation of four P-phenyl groups.
[0045] Additive Effects in the Rh-PennPhos Catalyzed Asymmetric Hydrogenation of Acetophenone
[0046] New chiral bisphosphines based on the 1,2-bis{(2,5-endo-dialkyl-1-7-phosphabicyclo[2.2.1]heptyl} benzene skeleton (sometimes hereinafter abbreviated as “PennPhos”) were synthesized. A rhodium complex with (R, S, R, S) Me-PennPhos is an excellent catalyst for asymmetric hydrogenation of acetophenone, giving up to 96% enantiomeric excess of the (S) alcohol. These ligands contain a conformationally rigid phosphabicyclo[2.2.1]heptane framework, which dictates the approach of ketone substrates and thus leads to high enantioselectivity in asymmetric reactions. Detailed studies reveal the presence of catalytic amounts of additives is important for achieving high conversion and enantioselectivity in the hydrogenation reaction. Compared with prior art Rh catalysts, this catalytic system gives higher enantioselectivity in acetophenone reduction.
[0047] We have designed conformationally rigid 2,5-endo-dialkyl-7 phosphabicyclo[2.2.1]heptanes as new chiral ligands and have demonstrated that these monophosphine species can be more effective for some asymmetric reactions than the conformationally flexible phosphacyclopentane. Herein we report the synthesis, and application of novel conformationally rigid chiral bisphosphines. 1,2-bis(2,5-endo-dialkyl-7-phosphabicyclo [2.2.1 ]heptyl)benzene (abbreviated as PennPhos).
[0048] The synthesis of PennPhos is illustrated in Scheme 2. These ligands are air-stable solids and can be handled easily on the bench top. These characteristics are in stark contrast to the DuPhos ligand, known to the prior art, which is conformationally flexible, a liquid at room temperature and unstable in air.
[0049] We have devoted much attention to enantioselective hydrogenation of simple ketones—one of the most fundamental reactions in organic chemistry—as a showcase for the development of new applications based on transition metal catalysts. Among the known group VII transition metal complexes, the most effective catalyst for hydrogenation of simple aromatic ketones is the Ru-BINAP-chiral diamine-KOH system disclosed, for example, in X. Zhang, et al. J. Am. Chem. Soc., 1993, 115, 3318, which . produced an enantiomeric excess on the order of 87-99%. Much lower enantioselectivities were reported with Rh and other metal catalysts bearing chiral bisphosphines. Development of a truly efficient catalytic system for enantioselective hydrogenation of simple ketones remains a challenging goal in synthetic chemistry. Since PennPhos ligands are more electron rich than triaryl phosphines, Rh-PennPhos catalysts have good activity towards asymmetric hydrogenation of simple ketones.
TABLE 3 Equiv. of Additive vs Rh-Catalyst Conversion (% ee) Entry Additive 0.0 0.1 0.15 0.2 0.3 1.0 1 NaOMe 45(57) 56(70) 69(83) 71(88) 41(80) 25(15 R) 2 NaOH 79(84) 85(91) 43(86) 23(25 R) 3 NaOPh 67(77) 80(87) 54(28) 16(28 R) 4 LiOBu t 80(91) 58(89) 19(78) 20(23 R) 5 LiCl 49(66) 46(70) 47(72) 44(67) 6 KF 78(84) 87(91) 73(90) 39(87) 7 KBr 74(80) 82(88) 85(89) 89(92) 8 Kl 71(81) 77(86) 73(90) 15(73) 9 Et3N 78(92) 28(82) 18(4 R) 10 DBU 81(90) 39(84) 18(26 R) 11 Proton Sponge 75(86) 84(90) 31(81) 10(21 R) 12 Pyridine 56(77) 47(74) 33(70) 13(55) 13 2-Me-Imidazole 86(87) 94(94) 79(92) 12(1) 14 DABCO 78(87) 84(90) 88(95) 55(92) 9(63) 15 2,6-Lutidine 72(83) 84(90) 94(94) 97(95) 93(95) 16 2,4,6-Collidine 82(88) 90(92) 97(95) 96(96) 75(95)
[0050] Table 3 outlines the asymmetric hydrogenation results using acetophenone as a typical substrate and a rhodium complex of 1,2-bis(2,5-endo-dimethyl-phosphabicyclo[2.2.1]heptyl) benzene (Me-PennPhos) as the catalyst according to the following:
[0051] The reaction was carried out at room temperature under 30 atm of H 2 for 24 hours. The ratio of substrate (0.5 mmol. 0.125 M):[Rh(COD)CI] 2 :ligand was 1:0.005:0.01. Conversion and percent enantiomeric excess were determined by GC with a Supleco β-DEX 120 column. The absolute configuration was determined by comparing the optical rotation of the product with values reported in the literature.
[0052] Initial extensive screening of catalytic conditions shows that the asymmetric hydrogenation gives good enantioselectivity and activity using [Rh(COD)CI] 2 as the precursor under 30 atm of H 2 in MeOH. A significant finding in our study is the dramatic effect of additives in the catalytic system. Not only does the enantioselectivity strongly depend on the additives used, but catalytic activity also varies to a great extent.
[0053] Three major classes of additives have been screened in the catalytic system: ionic bases (entries 1 - 4 ), halide (entries 5 - 8 ) and neutral bases (entries 9 - 16 ).
[0054] The enantioselectivity of the reaction is a useful probe for understanding the reaction mechanism of the Rh-catalyzed hydrogenation. In the absence of additives, asymmetric hydrogenation of acetophenone catalyzed by the Rh-Me-PennPhos complex is sluggish and gives the secondary alcohol in only 57% enantiomeric excess (entry 1 ). In the presence of catalytic amounts of additives (0.1 - 0.2 equiv vs. Rh), both reactivity and enantioselectivity are increased.
[0055] Depending on the additives and the amount of the additives introduced, different effects are observed. For the four ionic bases (entries 1 - 4 ), addition of 1 equiv. of base to Rh shuts off the reaction and surprisingly gives alcohol with the opposite enantioselectivity. The halide effect was studied using different salts (entries 5 - 8 ). The presence of excess chloride shows little effect on the catalyst activity and selectivity (entry 5 ). Addition of iodide or fluoride ion initially accelerates the reaction and gives higher enantioselectivity (0.1-0.3 equiv). However, both enantioselectivity and activity drop when 1 equiv. of halide is used (entries 6 and 8 ). Interestingly, bromide can enhance both enantioselectivity and rate of the reaction over the entire concentration range (0.1 to 1 equiv., entry 7 ). Common organic amine bases (Et 3 N (entry 9 ), DBU (entry 10 ), and proton spronge (entry 11 )) were also examined as additives. Higher conversion and better enantioselectivity were observed when less than 0.2 equiv of base was present in the catalytic system. Using more than 0.3 equiv of the base causes a decrease in reactivity and enantioselectivity. The reaction gives the opposite enantioselectivity with low conversion when using 1 equiv. of the amine base (entries 9 - 11 ). 2-methyl-imidazole and DABCO (entries 12 - 14 ) also goes through first enhancement and then erosion of both the reactivity and selectivity. However, we found that 2,6-lutidine and 2,4,6- collidine have a different effect. Both enantioselectivity and conversion are increased when 0.1 to 1 molar equivalent of these bases are used in the catalytic system (entries 15 - 16 ). Up to 96% enantiomeric excess is observed for the hydrogenation of acetophenone, which is the highest enantioselectivity achieved with a group VIII transition metal hydrogenation catalyst. Thus, we have found that bromide ion, 2,6-lutidine and 2,4,6-collidine are useful promoters for the Rh-catalyzed enantioselective hydrozenation of acetophenone. Preferred concentrations of these additive range between 0.1 and 1.0 molar equivalents with respect to the transition metal used. Most preferred amounts of additive are 0.2 to 0.3 molar equivalents of the additives with respect to the transition metal.
[0056] Highly Enantioselective Hydrogenation of Simple Ketones Catalyzed by a Rh-PennPhos Complex
[0057] (R, S, R, S) Me-PennPhos was used as an effective ligand for asymmetric hydrogenation of simple ketones. Up to 96% enantiomeric excess has been obtained in the hydrogenation of many alkyl aryl ketones catalyzed by the Me-PennPhos-Rh compound. Furthermore, enantiomeric excesses ranging from 73% to 94% were achieved with a variety of alkyl methyl ketones. The Me-PennPhos-Rh catalyst offers higher enantioselectivity than was available with the hydrogenation catalysts of the prior art.
[0058] Asymmetric reduction of ketones to secondary alcohols is one of the most fundamental molecular transformations in organic chemistry. While efficient transition metal-catalyzed asymmetric hydrogenation systems for functionalized ketones have been realized, highly enantioselective hydrogenation with simple ketones that lack heteroatoms which can anchor the transition metals is not fully developed. Much effort have been focused on this active research area. Stoichiometric and catalytic hydride reduction, transfer hydrogenation, hydrosilylation and direct hydrogenation have been investigated extensively. Highly enantioselective reduction systems include boron reagents, alumina reagents, and oxazaborolidine catalysts. Although some of these systems have been widely used in academic labs and in industry, they are still far from a desirable “green” process in terms of reactivity because large amounts of waste are generated when using these stoichiomeric reducing agents or catalysts with low turnovers. Prompted by the high catalytic turnovers for the reduction of ketones based on transition metal catalysts, many groups have devoted their efforts to search new catalytic systems. Among the direction hydrogenation catalysts, promising results were achieved for asymmetric hydrogenation of aromatic ketones facilitated by a BINAP-Ru(II)-chiral diamine-KOH complex. In this complicated system, chiral diamine serves as an important stereochemistry controlling element as chiral BINAP. So far, none of simple metal-chiral bisphosphine complexes can be used for highly enantioselective hydrogenation of simple ketones. Furthermore, reduction of simple alkyl ketones generally gives low enantioselectivity in all systems with a few exceptions. To develop an efficient hydrogenation catalyst for simple ketones, we have recently made a novel conformationally rigid chiral bisphosphine, 1,2-bis{(1R, 2S, 4R, 5S)2.5-endo-dimethyl-7phosphabicyclo[2.2.1]heptyl}benzene (abbreviated as (R. S, R, S) Me-PennPhos), as disclosed herein.
[0059] Searching proper conditions for asymmetric reactions often is tedious and challenging work. Extensive screening on catalytic conditions shows that the asymmetric hydrogenation gives good enantioselectivity and activity using [Rh(COD)Cl] 2 as the precursor under 30 atm of H 2 in MeOH. We have found that bromide and 2,6-lutidine are important promoters for the Rh-catalyzed enantioselective hydrogenation of simple ketones. The major function of 2,6-lutidine may be to deprotonate Rh-H while the conjugated acid or MeOH can hydrolyze the Rh-OR bond.
[0060] [0060]FIG. 4 summarizes the asymmetric hydrogenation results using various simple ketones as substrates and a Rh-I complex as the catalyst. Two sets of reaction conditions were applied to achieve high enantioselectivity: introduction of 0.4 equiv of 2,6-lutidine vs Rh or addition of both 0.8 equiv of 2,6-lutidine and 1 equiv of KBr vs Rh. For most aryl methyl ketones (entries 1-3, entries 6-9 and entries 13-15), constant high enantioselectivities (% enantiomeric excess ranging from 93 to 96) were observed. The reactivity and enantioselectivity drop with aryl methyl ketones which have an ortho substituted alkyl on the aryl group (entry 4 ). However, hydrogenation of potential chelating ketones (entry 9 and 15 ) gives high enantioselectivity. Presence of both 2,6-lutidine and KBr accelerates the enantioselectivy and activity (entry 5 vs 4 ; entry 7 vs 6 ; entry 11 vs 10 ). This condition was then used for the hydrogenation reaction of other ketone substrates. Increasing the bulk of the methyl group to ethyl or isopropryl in the alkyl aryl ketones dramatically decreases the activity and enantioselectivity (entry 1 vs entry 10 , entry 11 vs entry 12 ). This clearly indicates that the chiral environment in Rh-1 can effectively discriminate methyl against other alkyl groups. To confirm this assumption, we have carried out asymmetric hydrogenation of several alkyl methyl ketones (entries 16 - 21 ). Up to 94% enantiomeric excess for t-butyl methyl ketone (entry 19 ) and 92% enantiomeric excess for cyclohexyl methyl ketone (entry 21 ) were obtained. The enantioselectivity decreases when the size of alkyl group becomes smaller. With isopropryl methyl ketone and isobutyl methyl ketone, 84% ee (entry 20 ) and 85% ee (entry 18 ) were achieved, respectively. However, even with unbranched alkyl groups in the alkyl methyl ketones, high enantioselectivities (73% ee, entry 16 ) and (75% ee, entry 17 ) are still achievable. To the best of our knowledge, asymmetric hydrogenation of alkyl methyl ketones catalyzed by Rh-PennPhos gives higher enantioselectivity compared with other hydrogenation catalysts.
[0061] In conclusion, we have developed the PennPhos system as a highly enantioselective hydrogenation catalyst for both alkyl aryl ketones and alkyl methyl ketones.
EXPERIMENTAL
[0062] In all of the syntheses described herein, unless otherwise indicated, all reactions were carried out under nitrogen. THF and ether were freshly distilled from sodium benzophenone ketyl. Toluene and 1,4-dioxane were freshly distilled from sodium. Dichloromethane and hexane were freshly distilled from CaH 2 . Methanol was distilled from magnesium and CaH 2 . Reactions were monitored by thin-layer chromatography (TLC) analysis. Column chromatography was performed using EM silica gel 60 (230- 400 mesh). 1H NMR were recorded on Bruker ACE 200, WP 200, AM 300 and WM 360 spectrometers. Chemical shifts are reported in ppm downfield from tetramethylsilane with the solvent resonance as the internal standard (CDCl 3 , δ 7.26 ppm). 13 C, 31 P and 1 H NMR spectra were recorded on Bruker AM 300 and WM 360 or Varian 200 or 500 spectrometers with complete proton decoupling. Chemical shifts are reported in ppm downfield from tetramethylsilane with the solvent resonance as the internal standard (CDCl 3 , δ 77.0 ppm). Optical rotation was obtained on a Perkin-Elmer 241 polarimeter. MS spectra were recorded on a KRATOS mass spectrometer MS {fraction (9/50)} for LR-EI and HR-EI. GC analysis were carried on Helwett-Packard 5890 gas chromatograph with a 30-m Supelco β-DEX™ column. HPLC analysis were carried on WatersTM 600 chromatograph with a 25-cm CHIRALCEL OD column.
[0063] Synthesis of BICP
[0064] 1,1′-Dihydroxy-1,1′-dicyclopentyl (1) was synthesized from cyclopentanone as follows:
[0065] Mercuric chloride (20 g, 73 mmol) and benzene (300 ml) were added to a 2 L three-necked round bottom flask. Coarse aluminum powder (40 g, 1.48 mol) was added to this mixture at a rate sufficient to keep benzene at reflux. The mixture was stirred at room temperature for 15 min. Cyclopentanone (200 g , 2.4 mol) was added dropwise to the suspension of Al-Hg alloy in benzene (˜8 h) and the mixture was stirred for an additional 2 hours. The reaction mixture was cooled at 0° C. and iced water (100 mL) was added. Diethyl ether (300 mL) was added to extract products. The mixture was filtered through a celite and the filtrate was washed with ether. The combined organic phase was dried over Na 2 SO 4 and evaporated under vacuum. 1,1′-Dihydroxy-1, 1′-dicyclopentyl (1) (120 g) was obtained as a white solid, yield 56%.
[0066] 1,1′-dicyclopentyl (2) was synthesized from (1) as follows:
[0067] Pyridine (84 mL, dried over NaOH), POC1 3 (17 mL) and 1, 1′-Dihydroxy- 1, 1′-dicyclopentyl (1) (17 g ) were added to a 250 mL Schlenk flask under N 2 . The mixture was heated until the reaction took place (vigorous initiation as an exothermic reaction). The mixture was then cooled in an ice bath to prevent overheating. The mixture was heated to 100° C. for 6 hours. Ice water (300 mL) was added to this mixture and stirred at room temperature for 30 minutes. The mixture was extracted with pentane (3×200 mL) and the pentane extract was washed with 10% hydrochloric acid (3×20 mL), aqueous sodium bicarbonate (30 mL) and water (30 mL) and then dried over sodium sulfate. Removal of the pentane followed by distillation gave the product (55° C. at 1 mm) as a light yellow liquid. The yield was 81%.
[0068] The data for the 1, 1′-dicyclopentyl (2) product were 1 H NMR (CDCl3): 5.6 (s, 4H), 2.52-2.41 (m), 1.96-1.83 (m) ppm.
[0069] From 1, 1′-dicyclopentyl(2), the synthesis of BICP may proceed as follows:
[0070] (1 R, 1′R)-Bicyclopentyl-(2S, 2′S)-diol was synthesized by asymmetric hydroboration of bi-1-cyclopenten-1-yl using (+)-monoisopinocampheylborane (sometimes referred to hereinafter as “(+)-IpcBH 2 ” or simply “lpcBH 2 ”) according to the procedure described in H. C. Brown, et al., J. Org. Chem. 1982, 47, 5074, incorporated by reference herein. It may be noted that a product having the opposite enantiomeric configuration would be produced using the (−)-IpcBH 2 . The solution of enantiomerically pure (+)-IpcBH 2 (0.6 M, 200 mmol, 300 mL in ether) was cooled to −20° C. and HCl in ether (200 mL, 1.0 M, 200 mmol) was slowly added to this solution. The mixture was stirred for 30 min at 0° C. and then was cooled to −25° C. 1,1′-dicyclopentyl (10 g, 75 mmol) was added and the mixture was stirred at −25° C. for 24 hours. The mixture was warmed to 0° C. and stirred for another 24 hours. The reaction was quenched with methanol at −25° C. Hydroperoxide work-up was performed as described in the abovementioned H. C. Brown article. The crude mixture was purified by chromatography (first hexanelethyl acetate (5/1) and then hexanelethyl acetate (3/1)). The first component eluted is pinene alcohol, the second component is the desired diol (2.56 g, yield 18.3%, 93% enantiomeric excess) and the third component is meso diol (7.3 g, yield 58%). The absolute configuration of the diol was assigned based on the asymmetric hydroboration of trisubstituted olefins (e.g. methylcyclopentene) using (+)-IpcBH 2 .
[0071] Data for the diol were as follows: 1 H NMR (CDCl 3 , 300 MHz) δ 4.04(br, 2 H), 3.84 (m, 2 H), 2.02 (m, 2 H), 1.66-1.22 (m, 10 H), 1.21 (m, 2 H); 13 C NMR δ 78.6, 52.2, 33.6, 29.2, 20.5; MS m/z 170 (M+, 0.35), 152, 134, 108 , 95, 84, 68, HRMS calcd for C10111802: 170.1307(M+); found: 170.1315. Enantiomeric excess was determined by a chiral capillary GC column (Supelco TM y-DEX 225, 160° C. t meso diol=19.88 min, (IR, 1′R, 2S, 2′S) diol=20.92 min, (1S, 1′S, 2R, 2′R) diol=21.42 min).
[0072] (1 R,1′R)-Bicyclopentyl-(2S,2′S)-diol bis(methanesulfonate) was synthesized from the above diol. To a solution of (1 R, 1′R)-bicyclopentyl-(2S, 2′S)-diol (0.8 g, 4.65 mmol) and triethylamine (1.68 mL, 12.09 mmol) in CH 2 Cl 2 (30 mL), was added dropwise a solution of methanesulfonyl chloride (0.76 mL, 9.92 mmol) in CH 2 Cl 2 (2 mL) at 0° C. The reaction mixture was stirred at 0° C. for 30 min, and at room temperature for 2 h, then quenched by saturated aqueous ammonium chloride solution (25 mL). The aqueous layer was extracted with CH 2 Cl 2 (3×20 mL) and the combined organic solution was dried over Na 2 SO 4 . After evaporation of the solvent, a white solid was obtained, which was used directly for the next step.
[0073] Data for the diol-methanesulfonate were 1 H NMR (CDCl 3 , 200 MHz) δ 5.01 (m, 2H), 3.04 (s, 6 H), 2.17 (m, 2 H), 2.15-1.65 (m, 10 H), 1.43-1.52 (m. 2 H); 130 NMR δ 86.8, 48.2, 38.4, 32.8, 27.4, 22.5.
[0074] To synthesize (1 R, 1′R, 2R, 2′R ) -1, 1′- B is (2-diphenylphosphino) cyclopentyl bisborane, diphenylphosphine (1.25 mL, 7.0 mmol) in THF (80 mQ) was cooled to −780° C. To this solution, n-BuLi in hexane (4.1 mL, 6.6 mmol) was added via syringe over 5 min. The resulting orange solution was warmed to room temperature and stirred for 30 min. After cooling the mixture to −78° C., the above (1R, 1′R, 2S, 2′S)-1,1′-bicyclopentyl-2,2′-diol bismesylate (1.01 g, 3.1 mmol) in THF (20 mL was added over 20 min. The resulting orange solution was warmed to room temperature and stirred overnight. The white suspension solution was hydrolyzed with saturated aqueous NH 4 Cl solution. The aqueous layer was extracted with CH 2 Cl 2 (2×20 mL). The combined organic solution was dried over anhydrous Na 2 SO 4 . After removal of the solvents under reduced pressure, the residue was dissolved in CH 2 Cl 2 (50 mL), then treated with BH 3 -THF (10 mL, 10 mmol) at room temperature and the mixture was stirred overnight. The reaction mixture was added to NH 4 Cl aqueous solution, and extracted with CH 2 Cl 2 (2×50 mL). The combined organic solution was dried over anhydrous Na 2 SO 4 . After evaporation of the solvent under reduced pressure, the residue was subjected to column chromatography on silica gel, eluting with CH 2 Cl 2 /hexane (1:5) and then CH 2 Cl 2 /hexane (2:3) affording the product as a white solid. Yield: 0.36 g (21%).
[0075] Data for the compound were: 1 H-NMR (CDCl 3 ) δ 7.80-7.30 (m, 20 H, Ph), 2.55-2.35 (m, 2 H, CHP(BH 3 )Ph 2 ), 1.95-1.35 (m, 14 H, CH 2 and CH), 1.7-0.5 (broad, 6 H, BH 3 ). 31 P-NMR (CDCl 3 ): (P=17.5 (br). 13 C-NMR (CDCl 3 ) δ 133.43 (d, 2 J(PC)=8.5 Hz. C ortho ), 132.08 (d, 2 J(PC)=8.5 Hz, C ortho ), 132.08 (d, 1 J(PH)=50.0 Hz, C ipso ), 130.67 (d, 4 J(PC)=2.1 Hz, C para ), 130.57 (d, 4 J(PC)=2.1 Hz, C para ), 129.71 (d, 1 J(PC)=56.5 Hz, C ipso ), 128.39 (d, 3 J(PC)=9.4 Hz, C meta ),128.29 (d, 3 J(PC)=9.1 Hz, C meta ), 46.28 (dd, J(PC)=2.1 and 4.8 Hz, C 1, 1,), 36.26 (d, 1 J(PC)=30.6 Hz, C 2.2 ), 31.19 (CH 2 ), 29.52 (CH 2 ), 22.51 (CH 2 ); MS m/z 520 (8.95), 506 (3.55), 429(19.10), 321(100), 253(7.45), 185(26.64), 108(43.68), 91(11.99), 77(6.88), HRMS cacld for C 28 H 31 P 2 (M+−B 2 H 6 −Ph): 429.1901, found: 429.1906.
[0076] (2R, 2′R)-Bis(diphenylphosphino)(1R, 1′R)-dicyclopentane (sometimes referred to hereinafter as “(R,R) BICP”, or simply “BICP”) was synthesized by adding tetrafluoroboric acid-dimethyl ether complex (0.55 mL, 4.5 mmol) dropwise via syringe at −5° C. to a solution of the above borane complex of the phosphine (0.24 g, 0.45 mmol) in CH 2 Cl 2 (4.5 mL). After the addition, the reaction mixture was allowed to warm slowly to room temperature, and stirred for 20 hours. The mixture was diluted with CH 2 Cl 2 , and neutralized with saturated aqueous NaHCO 3 solution. The aqueous layer was extracted with CH 2 Cl 2 . The combined organic solution was washed with brine, followed by water, and dried over Na 2 SO 4 . Evaporation of the solvent gave the pure phosphine. Yield: 0.21 g (93%).
[0077] Data for the compound were: 1 H NMR (CDCl 3 , 360 MHz) δ 7.52-7.27 (m, 20 H), 2.53 (m, 2 H), 2.27 (m, 2 H), 1.93(m, 2 H), 1.72(m, 2 H), 1.70-1.43 (m, 8 H); 13C NMR (CDCl 3 ) δ139-127 (Ph), 45.9 (d, J=12.1 Hz), 45.8 (d, J=12.0 Hz), 40.34 (d, J=14.0 Hz), 30.9 (m), 23.8 (m); 31 P NMR (CDCl 3 ) δ −14.6. This phosphine was fully characterized by its borane complex.
[0078] The above example is non-limiting, and other synthetic routes for obtaining BICP are described in co-pending application Ser. No. 08/876,120.
[0079] Synthesis of (2S, 2′S)-bis(diphenylphosphinoxy)-(1R, 1′R)-dicyclopentane
[0080] (1R, 1′R)-Bicycopentyl-(2S, 2′S)-diol was made according to methods set forth in G. Zhu, et al., “Highly Enantioselective Rh-catalyzed Hydrogenations with a New Chiral 1, 4-Diphosphine Containing a Cyclic Backbon,” J. Am. Chem. Soc. 119(7), 1799-1800 (1977), incorporated by reference herein.
[0081] (2S, 2′S)-Bis(diphenylphosphinoxy)-(1R, 1′R)-dicyclopentane 1 H-NMR (CDCl 3 ) δ 7.50˜7.43 (m, 8 H), 7.36˜7.26 (m, 12 H), 4.22˜4.20 (m. 2 H), 2.15 (m. 2 H). 1.82˜1.66 (m, 8 H), 1.59˜1.53 (m. 2 H), 1.28˜1.21 (m. 2H); 31 P-NMR (CDCl 3 ): δ P=106.7; 13 C-NMR (CDCl 3 ) δ 143.18˜142.70 (m), 130.38-130.07 (m), 128.90 (s. 129.18-128.08 (m), 85.56 (d, J=17.9 Hz), 49.29 (d, J=6.52 Hz), 33.78 (d, J=5.61 Hz). 27.06 (s). 22.59 (s). MS m/z: 538, 461, 383, 353, 337, 201, 185, 151, 135, 77; HRMS calcd for C 34 H 36 O 2 P 2 (M+): 538.2190. found: 538.2156.
[0082] (1R, 1′R)-Bicyclopentyl-(2R, 2′R)-diol [α] 25 D =−54.0 (c, 1.07. CHCl 3 ): 1 H-NMR (CDCl 3 ) δ 4.30˜4.28 (m, 2H), 1.87˜1.49 (m, 14 H); 13 C-NMR (CDCl 3 ) δ 74.21. 45.59. 35.23. 28.27. 21.62. MS m/z: 152, 134, 121, 108, 67, 41, 37; HRMS calcd for C 10 H 17 O (M+−OH): 153.1279; found: 153.1238.
[0083] (2R, 2′R)-Bis(diphenylphosphinoxy)-(1R, 1′R)-dicyclopentane 1 H-NMR (CDCl 3 ) δ 7.48˜7.40 (m. 8 H), 7.35˜7.27 (m, 12 H), 4.11˜4.09 (m. 2 H), 1.86˜1.70 (m. 8 H). 1.58˜1.50 (m, 4 H), 1.50˜1.30 (m, 2H), 31 P-NMR (CDCl 3 ): δ P=106.1; 13 C-NMR (CDCl 3 ) δ 143.79˜142.70 (m), 131.19˜127.99 (m), 83.44 (dd, J 1 =2.01 Hz, J2=19.4 Hz). 46.03 (d. J=6.44 Hz), 33.42 (d, J=4.98 Hz), 28.30 (s), 21.58 (s). MS m/z: 538, 461, 383, 353, 337, 269, 201, 185, 151, 135, 77; HRMS calcd for C 34 H 36 O 2 P 2 ) (M+): 538.2190. found: 538.2159.
[0084] Determination of Enantiomeric Excess
[0085] Chiral Capillary GC. Column: Chirasil-VAL III FSOT column. Dimensions: 25 m×0.25 mm (i.d.). Carrier gas: He (1 mL/min). The racemic products were obtained by hydrogenation of substrates with an achiral catalyst. The following is the retention time for the racemic products: N-Acetylphenylalanine methyl ester (capillary GC, 1 50° C., isothermal) (R) t 1 =14.66 min. (S) t 2 =16.23 min, N-acetylalanine methyl ester (capillary GC, 100° C., isothermal) (R) t 1 =5.56 min, (S) t 2 =6.73 min; N-acetyl-m-bromophenylalanine methyl ester (capillary GC, 180° C., isothermal) (R) t 1 =14.14 min, (S) t 2 =15.09 min. N-benzoylphenylalanine methyl ester (capillary GC, 180° C., isothermal) (R) t 1 =35.65 min, (S) t 2 =37.13 min: N-Acetylleucine methyl ester (capillary GC, 110° C., isothermal) (R) t 1 =16.1 min. (S) t 2 =19.4 min. N-Acetyl-p-fluorophenylalanine methyl ester (capillary GC. 180° C. isothermal) (R) t 1 =5.02 min, (S) t 2 =5.28 min; N-Acetyl-o-chlorophenylalanine methyl ester (capillary GC, 180° C., isothermal) (R) t 1 =9.32 min, (S) t 2 −=9.78 min: N-Acetyl-3(2-naphthyl)alanine methyl ester (capillary GC, 190° C., isothermal): (R) t 1 =27.88 min. (S) t 2 ,=29.30 min; N-Acetyl-3-(2-thienyl) alanine methyl ester (capillary GC. 170° C. isothermal) (R) t 1 =7.21 min, (S) t 2 =7.54 min.
[0086] Chiral HPLC. Column: Daicel Chiralcel OJ (p-toloyl cellulose ester coated on silica gel). Particle size: 5.0 um. Column dimensions: 25 cm (length)×0.46 cm (i.d.). Column temperature: 25° C. N-Acetyl-p-methoxyphenylalanine methyl ester (HPLC, 1.0 mL/min, 10% 2-PrOH/hexane), (S) t 1 =62.52 min, (R) t 2 =72.45 min, N-Acetyl-p-acetoxy-m-methoxyphenylalanine methyl ester (HPLC, 1.0 mL/min, 10% 2-PrOH/hexane). (R) t 2 =70.75 min, (S) t 1 =73.70 min.
[0087] Synthesis of Modified BICP
[0088] To a mixture of Mg (6.70 g, 0.275 mmol) in THF (150 mL) was added a solution of 3.5-dimethylphenylbromide (50 g, 0.262 mmol) in THF (50 mL) dropwise. After addition, the mixture was cooled to room temperature, and then stirred for another hour. The reaction mixture was cooled to 0° C., a solution of PCl 3 (5.08 mL, 58 mmol) in THF (10 mL) was added slowly. Then the reaction mixture was heated at reflux for 2 hours. The reaction mixture was quenched with NH 4 Cl (sat. aq. at 0° C.). Extracted by benzene, the combined organic layer was washed by NaHCO 3 , and brine. After drying over sodium sulfate, the solvent was removed under reduced pressure. The product was obtained by recrystallization from EtOH, 10.5 g.
[0089] To a solution of triaryl phosphine (28.0 g. 80.8 mmol) in THF (210 mL) was added Li (1.17 g, 2.08 eq) in portions. Then the reaction was stirred at room temperature for two days. The reaction was quenched by adding water at 0° C., and stirred until all solid was dissolved. Extracted with ether (3×40 mL), the combined organic layer was washed with HCl (1˜2% aq., followed by water (40 mL×3). Dried over Na 2 SO 4 , after the solvent was evaporated, the product was obtained by distillation: 16.0 g, 160˜165° C./0.2 mmHg.
[0090] To a solution of (1R, 1′R-bicyclopentyl-(2S, 2′S)-diol (1 g, 5.87 mmol) and triethylamine (2.13 mL) in CH 2 Cl 2 (40 mL) was added dropwise a solution of methanesulfonyl chloride (0.973 mL) in CH 2 Cl 2 (2 mL) at 0° C. After 30 min at 0° C., the reaction mixture was stirred for additional 2 h at room temperature, then quenched by saturated aqueous ammonium chloride solution (25 mL). The aqueous layer was extracted with CH 2 Cl 2 (3×20 mL) and the combined organic solution was dried over Na 2 SO 4 . After evaporation of the solvent, a white solid was obtained, (1 R,1 ′R)-Bicyclopentyl-(2S, 2′S)-diol bis (methanesulfonate), which was used directly for the next step.
[0091] Data for the compound were as follows: 1 H NMR (CDCl 3 , 200 MHz) δ 5.01 (m, 2H), 3.04 (s, 6 H), 2.17 (m, 2H), 2.15-1.65 (m, 10 H), 1.43-1.52 (m, 2 H); 13 CNMR δ 86.8, 48.2, 38.4, 32.8, 27.4, 22.5.
[0092] To a solution of diarylphosphine (3.19 g) in THF (140 mL) was added n-BuLi in hexane (7.7 mL, 1.6 M) at −78° C. over 5 min via syringe. The resulting orange solution was warmed to room temperature and stirred for 30 min. After cooling the mixture to −78° C., (1R, 1′R, 2S, 2′S)-1,1′-bicyclopentyl-2,2′-diol bismesylate in THF (20 mL) was added over 30 min. The resulting orange solution was warmed to room temperature and stirred overnight. The white suspension solution was hydrolyzed with saturated aqueous NH 4 Cl solution. The aqueous layer was extracted with CH 2 Cl 2 (3×20 mL), and the combined organic solution was dried over anhydrous Na 2 SO 4 . After removal of the solvents under reduced pressure, the residue was dissolved in CH 2 Cl 2 (90 mL), then treated with BH 3 .THF (19 mL) at room temperature and the mixture was stirred overnight. The reaction mixture was added to NH 4 Cl aqueous solution, and extracted with CH 2 Cl 2 (3×50 mL). The combined organic solution was dried over anhydrous Na 2 SO 4 . After evaporation of the solvent under reduced pressure, the residue was subjected to column chromatography on silica gel. The product was the desired (1R, 1′R, 2R, 2′R)-1,1′Bis(2-diarylphosphino)cyclopentyl bisborane, formed with a yield of 1.0 g.
[0093] Data for the compound were as follows: [α] 25 D=−9.63 (c 1.36, ChCl 3 ); 1H NMR (CDCl 3 , 300 MHz) δ 7.25˜7.21 (m, 4H), 7.07 (s, 2H), 7.00˜6.98 (m, 4H), 6.94 (s, 2H), 2.40 (s, 12H), 2.34 (s, 12 H), 2.33˜2.19 (m, 2H), 1.83˜1.29 (m, 14 H); 13 C NMR (CDCl 3 ) δ 139.9˜125.2 (Ph), 47.6˜47.1 (m), 39.1 (d, 14.0 Hz), 30.9(m), 22.4(m), 21.4, 21.3; 31 P NMR(CDCl 3 ) 67 -16.9.
[0094] (2R, 2′R)-Bis(diarylphosphino)-(1R, 1′R)-dicyclopentane was made as follows: To a solution of the above borane complex of the phosphine (0.95 g mmol) in CH 2 Cl 2 (14.6 mL) was added tetrafluoroboric acid-dimethyl ether complex (1.79 mL) dropwise via syringe at −5° C. After the addition, the reaction mixture was allowed to warm slowly to room temperature, and stirred for 20 hours. The mixture was diluted with CH 2 Cl 2 , and neutralized with saturated aqueous NaHCO 3 solution. The aqueous layer was extracted with CH 2 Cl 2 . The combined organic solution was washed with brine, followed by water, and dried over Na 2 SO 4 . Evaporation of the solvent gave the pure phosphine.
[0095] Synthesis of PennPhos
[0096] The synthesis of PennPhos and many derivatives is described in co-pending application Ser. No. 08/876,120. Referring to Scheme 2, additional details of the synthesis are set forth below.
[0097] To synthesize 1,4-Dimethylcyclohexane-1,4-diene, 250 ml ethylamine wis charged to a 1 L flask fitted with cooling finger (−78° C.) and a stirring bar, and the solution was cooled to 0° C. Then, anhydrous p-xylene (54.9 g, 64 ml, 517 mmol) was added followed by the addition of ethyl alcohol (3×60 ml). Lithium wires (5.6 g) were added after each portion of ethyl alcohol (in total 16.8 g Lithium was added). After 3 h, the mixture was quenched with ice water (heat evolved). The aqueous layer was extracted with ether (3×150 ml), then dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporation. The residue was distilled and the product (30 g, 53.7%) was collected at 135-140° C.
[0098] (1S,2R,4S,5R)-(+)-2,5-Dimethylcyclohexane-1,4-diol was synthesized as follows. A 500 ml flask fitted with a rubber septum and a magnetic stirring bar was charged with IpcBH 2 (assumed 0.6 M, 300 ml, 18 1 mmol) in ether and cooled to −25° C. The IpcBH 2 was derived from (1 R)-(+)-α-pinene, 98%, 92+% enantiomeric excess, obtained from the Aldrich Chemical Co.; as with the previous example, the chirality of the product can be reversed using the (1 S)(−)-α-pinene. 1,4-Dimethylcyclohexane- 1,4-diene (7.5 g, 69.3 mmol) was added via syringe over 4 min. The reactants were stirred for 24 h at −25° C. and for 24 h at 0° C. The mixture was quenched with methanol (12.8 ml, 316 mmol) dropwise at −25° C. (hydrogen evolved). The solution was transferred to a 2 L flask and cooled to 0° C., then oxidized by successive slow addition of sodium hydroxide (4 M, 119 ml, 475 mmol) and hydrogen peroxide (30%, 49 mL, 475 mmol). The mixture was maintained at room temperature overnight. Two layers separated. The aqueous layer was extracted with ether (3×150 mL). The combined organic portion was dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. The oily residue was subjected to flash chromatography (Silica gel, 5:1 methylene chloride/acetone) and gave first pinene alcohol, C 1 -symmetrical diol and then desired C 2 -symmetrical diol as a white solid (5.5 g, 55%, 96% enantiomeric excess by GC using a Supleco β- 120 column).
[0099] (1S, 2R, 4S, 5R)-Dimethylcyclohexane-1,4-dimesylate was synthesized as follows. To a solution of (1S, 2R, 4S, 5R)-Dimethylcyclohexane-1,4-diol (16 g, 111 mmol) and triethylamine (37.6 mL, 267 mmol) in dry methylene chloride (500 mL) was added dropwise the solution of methanesulfonyl chloride (17.3 mL. 221.3) in methylene chloride (30 mL) at 0° C. The mixture was stirred for 30 min at 0° C. and for 2.5 h at room temperature. The reaction was quenched with saturated ammonium chloride solution (200 mL) at. 0° C. The aqueous layer was extracted with methylene chloride (3 ×150 mL). The combined organic phase was dried over anhydrous sodium sulfate and concentrated under vacuum, giving a light yellow solid. This product was passed through a short column of silica gel eluted with methylene chloride, which gave the desired product as a white solid (33.3 g, 99.9%).
[0100] To make (1R, 2S, 4R, 5S)-(+)-2,5-Dimethyl-7-phenyl-7-phosphabicyclo [2.2.1]heptane borane (FIG. 2, (5)), n-BuLi (34.5 mL of a 1.6 M solution in -hexane, 55 mmol) was added via syringe at −78° C. over 20 min to phenylphosphine (3.0 ml, 27.3 mmol) in THF (200 mL). Then the orange solution was warmed up to room temperature and stirred for 1 hr at room temperature. To the resulting orange-yellow suspension was added a solution of (1S,2S,4S,5S)-2,5-dimethycyclohexane- 1, 4-diol bis(methanesulfonate) (8.25 g, 27.5 mmol) in THF (100 mL) over 15 min. After the mixture was stirred overnight at room temperature, the pale-yellow suspension was hydrolyzed with saturated NH 4 Cl solution. The mixture was extracted with ether (2×50 mL), and the combined organic solution was dried over anhydrous sodium sulfate. After filtration, the solvents were removed under reduced pressure. The residue was dissolved in methylene chloride (100 mL), treated with BH 3 -THF (40 mL of a 1.0 M solution in THF, 40 mmol) and the mixture was stirred overni ght. It was then pured into saturated NH 4 Cl solution and extracted with CH 2 Cl 2 (3×50 mL). The combined organic solution was dried over anhydrous Na 2 SO 4 and filtered, the solvent was removed on reduced pressure. The residue was subjected to chromatography on slicon gel column, eluted with hexanes/CH 2 Cl 2 (4:1) affording the product as a white solid. Yield: 1.95 g (31%).
[0101] Data for the compound were as follows: [α] 25 D=+59.5° (c 1.07, CHCl 3 ). 1 H-NMR (CDCl 3 ) δ 7.60-7.30 (m, 5 H, C 5 H 5 ), 2.60-2.40 (m, 2 H, CHP(BH3)Ph), 2.15-2.05 (m. 1 H CH), 2.04-1.80 (m, 4 H, CH 2 ), 1.65-1.50 (m, 1 H, CH), 1.32 (d, 3 J(HH)=6.5 Hz, 3 H, CH-3), 0. 59 (d, 3 J(HH)=6.7 Hz, 3 H, CH 3 ),1.6-0.2 (br, BH 3 )- 13 C-NMR (CDCl 3 ) δ 131.74 (d, 2 J(PC)=7..3 Hz, C ortho ), 130.56 (d, 1 J(PC)=43.9 Hz, C ipso ),129.92 (d, 4 J(PC) =2.0 Hz, C para ), 128.44 (d, 3 J(PC)=8.6 Hz, C meta ), 43.07 (d, 1 J(PC)=30.5 Hz, CHP(BH 3 )Ph), 40.85 (d, 1 J(PC)=31.6 Hz,.CHP(BH3)Ph), 36.27 (CH 2 ), 36.67 (d, 3 J(PC) =13.5 Hz, CH 2 ), 35.91 (d, 2 J(PC)=3.5 Hz,CH), 34.65 (d, 2 J(PC)=9.8 Hz,CH), 20.78 (CH3) 20.53 (CH3); 31 P-NMR (CDCl 3 ) δ 36.3 (d, broad, 1 J(PB)=58.8 Hz); HRMS Calcd for C 14 H 22 BP:232.1552 (M+); found: 232.1578; C 14 H, 19 P:218-1224 (M + -BH3); found: 218.1233.
[0102] (1R, 2R, 4R, 5R)-(+)-2,5-Diisopropyl-7-phenyl-7-phosphabicyclo[2.2.1]heptane borane (FIG. 2, (6)) was synthesized using the same procedure as in the preparation of (5), with a yield of 50%.
[0103] The product was characterized as follows: [α]25 D=+25.5° (c 1.02, CHC1 3 )- 1 H-NMR (CDCl 3 ) δ 7.55-7.30 (m, 5 H, C 6 H 5 ) , 2.85-2.70 9 (m, 2 H CHP (BH 3 )Ph), 2.30-2.20 (m, I H, CH), 2.18-2.00 (m, 1 H, CH), 1.95-1.65 (m, 4 H, CH 2 ), 1.40-1.20 (m, 2 H, CH), 1.03 (d, 3 J(PH)=6.5 Hz, CH 3 ), 0.87(d, 3 J(PH)=6.7 Hz, CH 3 ), 0.85 (d, 3 J(PH)=7.4 Hz, CH 3 ), 0.53 (s, broad, 3 H, CH 3 ),1.5-0.2 (broad, BH 3 ); 13 C-NMR (CDCl 3 )δ 131.19 (d, 2 J(PC)=8.3 Hz, C ortho ) 130.71 (d, 1 J(PC)=45.2 Hz, C ipso ), 129.97 (d, 4 J(PC) =2.5 Hz, C para ), 128.45 (d, 3 J(PC)=9.5 Hz, C meta ), 50.30 (d, 2 J(PC)=2.1 Hz, CH), 48.77 (d, 2 J(PC) 9.7 Hz, CH), 38.27 (d, 1 J(PC)=30.5 Hz, CHP(BH 3 )Ph), 36.81 (CH 2 ), 36.71 (d, 1 J(PC)=31.5 Hz, CHP(BH 3 ) Ph), 34.73 (d, 3 J(PC)=13.7 Hz, CH 2 ) 31.92 (CHMe 2 ), 31.12 (CHMe2), 22.41 (CH 3 ), 21.55 (CH 3 ), 20.73 (CH 3 ), 20. 10 (CH 3 ); 3 P-NMR (CDCl 3 ) δ 36.d (d, broad, 1 J(PB)=51.4 Hz).
[0104] (1R, 2S, 4R, 5S)-(+)-2,5-Dimethyl-7-phenyl-7-phosphabicyclo[2.2.1] heptane (7). To a solution of corresponding borane complex of the phosphine (5, 1.0 g, 4.31 mmol) in CH 2 Cl 2 (22 mL) was added tetrafluoroboric acid-dimethyl ether complex (2.63 mL, 21.6 mmol) dropwise via a syringe at −5° C. After the addition, the reaction mixture was allowed to warm up slowly, and stirred at room temperature. After 20 h, 31 P NMR showed the reaction was over, it was diluted by CH 2 Cl 2 , neutralized by saturated NaHCO 3 aqueous solution. The aqueous layer was extracted with CH 2 Cl 2 . The combined organic solution was washed with brine, followed by water, and then dried over Na 2 SO 4 . Evaporation of the solvent gave a pure phosphine product, which was confirmed by NMR. Yield: 0.9 g (96%).
[0105] Data for the compound were as follows. [α] 25 D =+92.5° (c2.3, toluene); 1 H NMR (CDCl 3 , 360 MHz) δ 7.38-7.34 (m, 2H), 7.26-7.21 (m, 2H), 7.19-7.16 (m, 1H), 2.60-2.54 (m, 2H), 1.89-1.62 (m, 5H), 1.44-1.42 (m, IH), 1.16 (d, J =6.12 Hz, 3H), 0.55 (d, J=6.95 Hz, 3H); 13 C NMR (CDCl 3 ) δ 138.68 (d, J=29.3 Hz), 131.42 (d, J=13.0 Hz), 127.88 (d, J=2.35 Hz), 126.57 (s), 47.34 (d, J=13.5 Hz), 45.26 (d, J=10.2 Hz), 39.21 (d, J=6.7 Hz), 39.21 (d. J=5.3 Hz), 38.74 (d, J=6.7 Hz), 34.69 (d. 17.2 Hz), 22.37 (d, J=7.8 Hz), 21.52 (s); 31 P NMR(CDCl 3 ) δ −7.29.
[0106] Me-PennPhos: 1,2-Bis((1R,2S,4R,5S)-2,5-dimethyl-8-phenylphospha-bicyclo[2.2.1]heptyl)benzene. To the suspension of NaH (8.0 g, 333 mmol) in THF (200 ml), cooled to 0° C., was added 1,2-diphosphinobenzene (4.0 ml, 30.4 mmol), followed by HMPA (80 ml). The resulting orange suspension was stirred at 0° C. for 1 hours. (1S,2S,4S,5S)-2,5-dimethylcyclohexane-1,4-diol dimesolate (18.3 g, 60.9 mmol) in THF (150 ml) was added over 20 min. The resulting orange-red suspension was stirred at room temperature for 3.5 days, hydrolyzed with NaCl-H 2 O and then extracted with hexane (2×100 ml). The combined organic solution was dried over Na 2 SO 4 . After filtration, the solvents were removed under reduced pressure. The residue was subjected to chromatography on silica gel column, eluted with hexane. Yield: 3.0 g (27.5%).
[0107] Data for the compound were as follows: 1 H-NMR (CDCl 3 ): δ H=7.25-7.10 (IM, 2 H, aromatic), 7.08-6.95 (m, 2 H, aromatic), 3.21 (d, broad, 2 H, 2 J(PH)=14.5 Hz, PCH), 2.58 (d, broad, 2 H, 2 J(PH)=13.4 Hz, PCH), 1.90-1.60 (m, 12 H), 1.55-1.35 (m, 2 H,) 1.17 (d, 6 H, 3 J(HH)=6.3 Hz, CH 3 ), 0.60 (d, 6 H, 3 J(HH)=6.3 Hz, CH 3 ). CH. 13 C-NMR (is out of first order, CDCl 3 ): δC=143.94, 143.66, 143.48, 143.20, 131.05, 131.00, 130.93, 126.33, 46,24, 46.20, 46,17, 46.13, 45.92, 45.69, 45.61, 45.38, 40.17, 40.05, 39.89, 39.73, 39.61, 39.52, 39.33, 39.29, 39.26, 34.76, 34.61. 34.51, 34.41, 34.26, 22.69, 22.65, 22.61, 20.82. 31 P-NMR (CDCl 3 ): δP=−7.3 ppm.
[0108] i-Pr-PennPhos: 1,2-Bis{(1R,2R,4R,5R)-2,5-bis-isopropyl-8-phenylphos-phabicyclo [2.2.1] heptyl} benzene. 1,2-diphosphinobenzene (0.4 ml, 3.04 mmol) and NaH (0.9 g, 37.5 mmol) were mixed in THF (50 ml) and cooled to 0° C. HMPA (8.5 ml, 49 mmol) was added. The resulting orange suspension was stirred at 0° C. for 1 h and then (1S,2S,4S,5S)-2,5-dimethyl-cyclohexane-1,4-diol dimesolate (2.17 g, 6.08 mmol) in.THF (40 ml) was added over 10 min. The resulting orange-red suspension was stirred at room temperature for 3 days. After cooled to 0° C., it was hydrolyzed with NaCl-H 2 O, and extracted with hexane (2×50 ml). The combined organic solution was dried over Na 2 SO 4 and filtered. The solvents were removed under reduced presure. The residue was subjected to chromatography on silica gel column, eluted with hexane. Yield: 0.6 g (42%).
[0109] Data for the compound were as follows: 1 H-NMR (CDCl 3 ): δH=7.20-7.10 (m, 2 H, aromatic), 7.05-6.90 (m, 2 H, aromatic), 3.38 (d, broad, 2 H, 2 J(pH)=14.2 Hz, PCH), 2.85 (d, broad, 2 H, 2 J(PH)=13.5 Hz, PCH), 1.85-1.45 (m, 12 H), 1.30-1.08 (m, 4 H), 1.03 (d, 6H, 3 J(HH)=6.4 Hz, CH3), 0.96 (d, 6H, 3 J(HH) =5.6 Hz, CH3), 0.86 (d, 6H, 3 J(HH)=6.5 Hz, CH 3 ), 0.47 (s, 6 H, CH 3 ). 13 C-NMR (is out of first order, CDCl 3 ):δC=143.97, 143.62, 143.56, 143.50, 143.45, 143.09, 130.96, 130.90, 130.86, 126.11, 54.10, 54.06, 54.03, 48.65, 48.56, 48.46. 42.02, 41.96, 41.24, 41.20, 41.18, 41.14, 37.94, 37.77, 37.60, 37.46, 33.29, 33.27, 33.24, 31.69, 23,45, 23.40, 23.35, 22.22. 20.97, 20.54. 31 P-NMR (CDCl 3 ): δP=−8.7 ppm.
[0110] Synthesis of BICPO
[0111] Data for the phosphirite compound is as follows: 1 H-NMR (CDCl 3 ) δ 7.50˜7.43 (m, 8 H), 7.36-7.26 (m, 12 H), 4.22˜4.20 (m, 2 H). 2.15 (m, 2 H), 1.82˜1.66 (m, 8 H), 1.59˜1.53 (m, 2 H), 1.28˜1.21 (m. 2H); 31 P-NmR (CDCL 3 ): δ P=106.7; 13 C-NMR (CDCL 3 ) δ 143.18˜142.70 (m), 130.38˜130.07 (m). 128.90 (s), 128.18˜128.08 (m), 85.56 (d, J=17.9 Hz), 49.29 (d. J=6.52 Hz), 33.78 (d. J=5.61 Hz). 27.06 (s). 22.59 (s). MS m/z: 538, 461, 383, 353, 337. 201. 185. 151. 135. 77: HRMS calcd for C 34 H 36 O 2 P 2 ) (M+): 538.2190; found: 538.2156.
[0112] The enantiomer, (1R, 1′R, 2R, 2′R)-BICPO may be made by converting the absolute configurations of the 2,2′ positions of the (1R, 1′R)-bicyclopentyl-(2S, 2′S)-diol into (1R, 1′R)-bicyclopentyl-(2R, 2′R)-diol via a Mitsunobu reaction. This process is completely described by M. J. Arco, et al.,“ J. Org. Chem. 1976. 41. 2075 and D. L. Hughes, L. Org. React. 1992, 42, 387, which are incorporated by reference herein. Thus, a new bisphosphinite chiral ligand (1R, 1′R, 2R, 2′R) BICPO, having the same configuration as the original (1R, 1′R. 2R, 2′R)-BICP was made according to the above reaction scheme, but with a yield of 74.4%.
[0113] Other methods may be used to obtain the chiral product with the desired enantiomeric configuration, as described herein in connection with the BICP and in co-pending parent application Ser. No. 08/876,120. The reaction conditions and reagents employed are exemplary only, and are not intended to be limiting of the invention.
[0114] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. | This invention is to develop novel transition metal catalysts for the practical synthesis of important chiral molecules. The invention emphasizes asymmetric catalysis based on chiral bidentate phosphine ligands with cyclic ring structures which could be used to restrict conformational flexibility of the ligands and thus the efficiency of chiral transfer can be enhanced through the ligand rigidity. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a convergent-divergent turbojet nozzle. Such convergent-divergent nozzles, referred to in this text as CD nozzles, are generally fitted to military supersonic aircraft turbojets.
[0002] FIG. 1 shows diagrammatically a CD nozzle 1 of known type. This nozzle, of axis X, comprises a first ring of convergent flaps 2 and a second ring of divergent flaps 4 . Among the convergent 2 and divergent 4 flaps, the driven flaps 2 a , 4 a are distinguished from the follower flaps 2 b , 4 b.
[0003] The driven flaps 2 a , 4 a are connected to a drive mechanism 5 which is used to move them. This drive mechanism usually consists of levers, link rods, yokes, or a ring, rollers and cams. The movement of the driven flaps 2 a , 4 a enables the opening of the nozzle 1 to be modified to suit flight conditions, and for this reason the nozzle is said to be of variable section.
[0004] The follower flaps 2 b , 4 b are interposed between the driven flaps and, on either side, their lateral edges bear on the radially inner faces of the driven flaps 2 a , 4 a . The follower flaps are not connected to a drive mechanism and simply follow the driven flaps 2 a , 4 a.
[0005] The radial direction is defined in this text as the direction perpendicular to the axis X of the nozzle, and the inner face of an element as the face of the element which is nearest the axis X.
[0006] When the turbojet is running, a stream of hot gases is pouring through the nozzle 1 from the post-combustion chamber of the turbojet. By varying the opening of the nozzle, the drive mechanism 5 of the driven flaps 2 a , 4 a increases or decreases the exhaust velocity of the gaseous stream at the nozzle outlet.
[0007] The temperatures of the stream of hot gases passing through the CD nozzle are generally very high, and a number of cooling systems have been developed to limit the heating up of the radially inner faces of the nozzle flaps.
[0008] U.S. Pat. No. 5,775,589 discloses a CD nozzle for a military turbojet comprising follower divergent flaps supplied with cooling air.
[0009] This air flows through the inside of each flap before escaping through perforations, termed multi-perforations, in the inner wall of the flap. A protective film of air is thus formed against the surface of this wall, limiting the exchange of heat between the latter and said hot gases.
[0010] In one particular embodiment, the driven divergent flaps are not supplied with cooling air and therefore have no multiperforations, and only means for injecting air into the throat (the narrowest cross section) of the nozzle are provided to cool these flaps. However, such means are inadequate for properly cooling the driven divergent flaps, especially in regions of these flaps remote from said throat.
SUMMARY OF THE INVENTION
[0011] It is an object of the invention to improve the cooling of the driven flaps of a CD nozzle, especially when the driven divergent flaps are not themselves supplied with cooling air.
[0012] To achieve this object, the subject of the invention is a convergent-divergent turbojet nozzle comprising driven divergent flaps, follower divergent flaps interposed between the driven flaps, and means for supplying cooling air to the follower divergent flaps, the latter having a box structure with a radially inner wall and a radially outer wall. According to the invention, said follower divergent flaps also have lateral openings for delivering cooling air towards the inner face of said driven divergent flaps, to cool the latter.
[0013] The invention thus utilizes some of the cooling air supplied to the follower divergent flaps to cool the inner face of the driven divergent flaps. This is particularly useful when the driven divergent flaps are not themselves supplied with cooling air.
[0014] Limiting the heating up of the driven divergent flaps not only increases the life of the components of these flaps but also, in the context of military operations, helps reduce the infrared signature of the aircraft's nozzle.
[0015] In one particular embodiment of the invention, the outer and inner walls of the nozzle are fitted one inside the other along their lateral extremities but retain the freedom to slide over each other.
[0016] Thus, when the turbojet is running, the mechanical stresses within the flap are limited because said walls can slide over each other. Such mechanical stresses may result for example from differences of expansion between the outer and inner walls, owing to the fact that these walls are subjected to different temperatures.
[0017] Additionally, to optimize the performance of a CD nozzle, it is desirable to minimize the leakage of hot gases between the driven divergent flaps and the follower divergent flaps. For this reason, each follower flap must have torsional flexibility so that its lateral edges remain in contact with the inner surface of the two driven flaps on either side of it, even when there is a slight positional difference between these two flaps, which becomes frequent owing to the wear on the drive systems of these flaps. This torsional flexibility is improved by the ability of the external and internal walls to slide over each other.
[0018] Furthermore, to promote contact between the lateral edges of the follower divergent flaps and the inner surface of the driven divergent flaps, the lateral extremities of the outer and inner walls are curved.
[0019] In one particular embodiment of the invention, the outer and inner walls of the nozzle each have holes along their lateral extremities. The holes of one of the walls are aligned with the holes of the other wall when these walls are fitted one inside the other, and thus form said lateral openings.
[0020] Advantageously, the holes of one of the walls have a larger cross section than the holes of the other wall, so that the hole of smaller cross section always leads into the inside of the hole of larger cross section, whatever the position of the inner and outer walls relative to each other. This ensures the continued existence of lateral openings when the inner and outer walls slide over each other due to phenomena of expansion or twisting of the flap.
[0021] In one particular embodiment of the invention, the inner and outer walls of the follower divergent flaps each have at least one incision leading all the way in from their lateral periphery to one of said holes.
[0022] Such an incision makes it possible to reduce the mechanical stresses within the flap linked to expansion of the walls, or to twisting of the flap. Furthermore, as each incision leads into one of said holes, the development of cracks at the end of each incision is avoided.
[0023] In one particular embodiment of the invention, each follower divergent flap also comprises a spacer, situated between its inner wall and its outer wall, in the plane of symmetry of the flap. This spacer reinforces the structure of the flap and enables it to retain its shape even when the pressures exerted on its inner wall by the stream of hot gases passing through the nozzle are high.
[0024] Advantageously, each follower divergent flap of the nozzle also comprises a guide rail fixed to the outer wall of said flap, the cross section of said spacer is in the general shape of an I, the base of the spacer being fixed to the inner wall of said flap, and its upper part being able to slide in said guide rail.
[0025] This particular structure allows the inner wall of the flap to move relative to its outer wall. The invention thus succeeds in reinforcing the structure of the flap while maintaining its flexibility.
[0026] In one particular embodiment of the invention, the radially inner wall of the follower divergent flaps also has perforations through which the cooling air can escape. This makes it possible to create a protective film of air against the surface of the flap.
[0027] In another embodiment of the invention, said driven divergent flaps are not supplied with cooling air, and are therefore cooled only by the lateral openings present in the follower flaps.
[0028] This embodiment greatly simplifies the structure of the CD nozzle because it makes it possible to produce driven divergent flaps that do not have a hollow box structure that would be needed for the passage of cooling air. Instead, it is possible to produce flaps with a simple skin structure, that is a single wall. It is then easy to connect this type of driven flap to the drive members which control it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] A clearer understanding of the invention and its advantages will be gained from a reading of the detailed description of a preferred embodiment, illustrated in the following figures:
[0030] FIG. 1 is a perspective view of a CD nozzle of the prior art;
[0031] FIG. 2 is a cross section of a follower divergent flap of a nozzle according to the invention;
[0032] FIGS. 3 a and 3 b are detail views of the lateral openings of the flap of FIG. 2 ; and
[0033] FIG. 4 shows some divergent flaps of a nozzle according to the invention, viewed from the inside of the nozzle;
[0034] FIG. 5 is a perspective view of a CD nozzle according to the invention; and
[0035] FIG. 6 shows diagrammatically, in axial half-section, a CD nozzle according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The general structure of the nozzle according to the invention is similar to that of the nozzle shown in FIG. 1 and described earlier.
[0037] The nozzle 1 comprises convergent flaps 2 and divergent flaps 4 . Among the divergent flaps 4 , the driven divergent flaps 4 a are distinguished from the follower divergent flaps 4 b . Each follower divergent flap 4 b bears on the two adjacent driven divergent flaps in a region situated along its lateral edges.
[0038] The driven divergent flaps 4 a are pivoted at their upstream ends to the downstream ends of the driven convergent flaps 2 a , and the follower divergent flaps 4 b are also pivoted at their upstream ends to the downstream ends of the follower convergent flaps 2 b.
[0039] Each follower divergent flap 4 b has a box structure, and an approximately trapezoidal cross section, shown in FIG. 2 , with a radially inner wall 6 , and a radially outer wall 8 .
[0040] The lateral extremities 8 a of the outer wall 8 and the lateral extremities 6 a of the inner wall 6 are curved and the curvatures of the lateral extremities 6 a and 8 a are such that the inner and outer walls 6 and 8 can be fitted one inside the other, the extremities of the inner wall 6 a covering those of the outer wall 8 .
[0041] Also, the lateral extremities 6 a of the inner wall 6 form a slideway for the lateral extremities 8 a of the outer wall 8 , with the result that these walls can slide over each other in the axial direction.
[0042] The lateral edges of the follower divergent flap 4 b are therefore formed by the overlapping of the lateral extremities of the inner 6 and outer 8 walls.
[0043] The follower flap 4 b is also fitted with several spacers 20 distributed at regular intervals along the flap between the inner wall 6 and the outer wall 8 , in the plane of symmetry of the flap.
[0044] Each spacer 20 consists of a rectilinear web joined to a base and to an upper part, these both being perpendicular to the web, and the cross section of the spacer being in the general shape of an I. The base of the spacer is attached by welding, brazing or any other appropriate fixing means to the inner wall 6 of the flap. The upper part of the spacer 20 is composed of two arms 20 a which spread out on either side of the web of the spacer 20 , at right angles to the direction of this web.
[0045] Fixed to the outer wall 8 of the flap is an axial slideway 22 , or guide rail, containing a slot 24 lying in the plane of symmetry of the flap. The width of the slot 24 is greater than the thickness of the web of the spacer 20 , and the spacer 20 can therefore slide in the slideway 22 along the direction of the slot. The arms 20 a of the spacer 20 extend between the slideway 22 and the outer wall 8 , and are able to contact one or other of these parts to limit how far the inner 6 and outer 8 walls can come together or move apart, thereby improving the ability of the flap to maintain its shape.
[0046] As shown in FIGS. 3 a and 3 b , the inner and outer walls 6 , 8 each have holes 12 , 14 set out at regular intervals along their lateral extremities 6 a , 8 a.
[0047] When the walls 6 , 8 are fitted one inside the other, the holes 12 of the outer wall 8 are aligned with the holes 14 of the inner wall 6 , and thus form lateral openings in the structure of the follower flap 4 b.
[0048] The holes 12 of the outer wall 8 are oblong, i.e. elongated, and have a larger cross section than the circular holes 14 of the inner wall 6 . The size and shape of the oblong holes 12 are determined in such a way that the circular holes 14 are never masked, even when the outer 8 and inner 6 walls expand differently and/or when the follower flap 4 b twists and causes a displacement of the two walls 6 and 8 relative to each other.
[0049] Moreover, the inner and outer walls 6 , 8 are provided with incisions 16 and 18 , respectively, situated at regular intervals along their lateral extremities 6 a and 8 a . These incisions 16 and 18 start on the edge of the lateral extremities 6 a , 8 a and extend in at right angles to this edge all the way to the holes 12 and 14 formed in each of the walls 6 and 8 .
[0050] As shown in FIGS. 2 and 4 , the inner wall 6 of each follower flap 4 b has numerous perforations 26 in its central part. These are termed multiperforations.
[0051] Referring to FIGS. 4, 5 and 6 , when the driven flaps 4 a are not supplied with cooling air, and only the follower flaps are so supplied, the cooling of the divergent flaps of the nozzle described earlier takes place in the following manner.
[0052] The cooling air of the follower divergent flaps 4 b comes from a manifold (not shown) positioned upstream of the nozzle, referring to the direction of flow of the hot gases passing through it. The air drawn off is channelled into the follower divergent flaps 4 b , as shown diagrammatically in FIG. 6 , passing on its way under a thermally protective sleeve 30 of the turbojet upstream of the nozzle, and via a system of ducts 32 . The air then flows into the box structure of the divergent flaps 4 b and passes out through the perforations 26 and lateral openings 12 , 14 of said divergent flaps 4 b.
[0053] The cold air passing out through the perforations 26 in the direction indicated by the arrows F serves to limit the heating up of the inner walls 6 of the follower divergent flaps 4 b by creating a film of cool air on the inner face of these walls.
[0054] Cold air that passes out through the lateral openings 12 , 14 in the direction of arrows F′, on the other hand, is directed circumferentially towards the inner face of each of the driven divergent flaps 4 a and initially cools them by impact. Subsequently this cold air creates a protective film against the inner face of the driven divergent flaps 4 a , thereby attenuating the heat exchanges between the hot gases passing through the nozzle and these flaps 4 a , thus limiting the degree to which they heat up. | The present invention relates to a convergent-divergent turbojet nozzle ( 1 ) comprising driven divergent flaps ( 4 a ), follower divergent flaps ( 4 b ) interposed between the driven flaps, and means ( 32 ) for supplying cooling air to the follower flaps ( 4 b ), said follower flaps ( 4 b ) having a box structure and having lateral openings for delivering cooling air towards the inner face of said driven flaps ( 4 a ), in such a way as to limit the heating up of these flaps when the turbojet is in operation. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a filtering/separating and purifying system for purification of water and for solid-liquid separation, and particularly, to the construction of the filtering and purifying system capable of reducing the number of microorganisms such as bacteria remaining in treated water.
[0002] There is a magnetically separating and purifying system in which a fine metal net or a net knitted of polymer fibers is used as a through-flow separating membrane for the purpose of solid-liquid separation, and a flocculating agent and a magnetic powder are added to raw water containing polluting particles to be separated to thereby produce magnetic flocs. The magnetic flocs are then separated by the membrane, the magnetic flocs collected by the membrane are magnetically separated off and removed using a magnetic field-generating means, and a high-concentration sludge is recovered.
[0003] This construction is described, for example, in JP-A-2002-273261. The filtering/separating and purifying system includes a membrane separating section comprising a net formed of fine stainless steel wires or polyester fibers and having openings of an opening size of, for example, several tens micrometers. To separate a fine polluting material smaller than a projected area and a projected diameter of the openings, for example, alumina sulfate, aluminum polychloride or iron polysulfate as a flocculating agent and a magnetic powder are previously added to raw water and stirred, and a fine solid suspended matter, algae and microorganisms in the raw water are coagulated into a size on the order of several hundred micrometers by the flocculating agent to form magnetic flocs. The magnetic flocs can not pass through the openings having the opening size of several tens micrometers, and are separated and caught with a high removal rate. The water penetrated through the membrane is purified water having a high quality with the residue of the fine solid suspended matter, algae and microorganisms in the raw water being several percents.
[0004] The magnetic flocs caught on the membrane are washed away from the membrane by washing water, and thereafter, the magnetic flocs stagnating in the vicinity of water surface are attracted and magnetically separated by the magnetic force of a magnet disposed stationary in the vicinity of the water surface, and then transferred to a sludge recovery tank and eliminated by a sludge transfer means. Finally, the sludge may be burned off on a land or on a sea, or may be composted.
[0005] According to the above Patent document, bacteria having vigorous propagating power particularly under appropriate surrounding conditions, e.g., microorganisms such as colon bacilli remain in treated water at several percents of those in raw water, and colon bacilli propagate in a short time under the appropriate surrounding conditions. In a purifying system for life waste water, for example, in a ship in which the treated water is stored for a given period, the water is purified during voyaging of the ship in order to meet an effluent standard for life waste water, but there is a problem that for the period of storage of the treated water in a life waste water tank, colon bacilli in the treated water propagate for a voyaging period to deteriorate the quality of the treated life waste water beyond the effluent standard and as a result, discharging of the treated water becomes unacceptable.
BRIEF SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a filtering and purifying system capable of reducing the concentration of residual possible nutrients to remarkably reduce the propagating function of bacteria.
[0007] The above object is achieved by a filtering and purifying system comprising a production means for producing a product by coagulating matter to be removed in a fluid to be treated, chemically catching and bonding the matter, and a filtering means having an opening size through which the product provided by the production means at a size larger than that of the matter to be removed can not pass. A treating means for at least sterilizing or oxidizing the matter to be removed in the fluid to be treated is provided in the production means.
[0008] The above object is also achieved by a filtering and purifying system comprising a fluid storing means for storing a fluid to be treated, a production means for producing a product by coagulating matter to be removed in the fluid to be treated, chemically catching and bonding the matter, and a filtering means having an opening size through which the product provided by the production means at a size larger than that of the matter to be removed can not pass. A treating means for at least sterilizing or oxidizing the matter to be removed in the fluid to be treated is provided in the fluid storing means.
[0009] Further, the above object is achieved by a filtering and purifying system comprising a production means for producing a product by coagulating matter to be removed in a fluid to be treated, chemically catching and bonding the matter, a filtering means having an opening size through which the product provided by the production means at a size larger than that of the matter to be removed can not pass, and a treated-water storing means for storing treated water filtered by the filtering means. A treating means for at least sterilizing or oxidizing the matter to be removed in the fluid to be treated is provided in the treated-water storing means.
[0010] Furthermore, the above object is achieved by a filtering and purifying system comprising a production means for producing a product by coagulating matter to be removed in a fluid to be treated, chemically catching and bonding the matter, and a filtering means having an opening size through which the product provided by the production means at a size larger than that of the matter to be removed can not be pass. The production means has therein a fluid stirring means for stirring the fluid to be treated, and a treating means for at least sterilizing or oxidizing the matter to be removed in the fluid to be treated is provided in the fluid stirring means.
[0011] Yet further, the above object is achieved by a filtering and purifying system comprising a production means for producing a product by coagulating matter to be removed in a fluid to be treated, chemically catching and bonding the matter, and a filtering means having an opening size through which the product provided by the production means at a size larger than that of the matter to be removed can not pass through the filtering means. A plurality of treating means for at least sterilizing or oxidizing the matter to be removed in the fluid to be treated and a restoring means for restoring reduced sterilizing or oxidizing functions of the treating means are provided in the production means, and at least one or more of the treating means with the sterilizing or oxidizing functions restored function continuously during purifying operation.
[0012] According to the invention, it is possible to provide the filtering and purifying system capable of reducing the concentration of residual possible nutrients and remarkably reducing the propagating function of bacteria.
[0013] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0014] FIG. 1 is a flow diagram of the filtering and purifying system according to an embodiment of the invention.
[0015] FIG. 2 is a sectional view of a magnetically separating section in the embodiment of the invention.
[0016] FIG. 3 is a sectional view taken along a line A-A in FIG. 2 .
[0017] FIG. 4 is a flow diagram of the filtering and purifying system according to another embodiment of the invention.
[0018] FIG. 5 is a view for explaining a further embodiment of the present invention.
[0019] FIG. 6 is a view for explaining a still further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of the invention will be now described with reference to the drawings.
[0021] The first embodiment of the invention will be described with reference to FIGS. 1, 2 and 3 . FIG. 2 is an enlarged sectional view of a membrane separator 14 shown in FIG. 1 , and FIG. 3 is a sectional view taken along a line A-A in FIG. 2 .
[0022] Raw water 2 which is water to be treated, for example a life waste water introduced into a ship at a port visit, and from which large refuse of several millimeters has been removed, is stored in a raw water storage tank 1 , for example a life waste water tank in the ship, and the raw water 2 is fed in a predetermined amount to a pipe line 4 by a pump 3 . A magnetic powder such as iron tetroxide, a pH adjuster, a flocculating agent such as an aqueous solution of aluminum polychloride, ferric chloride or ferric sulfate which provides aluminum ion or iron ion, a polymer reinforcing agent and the like are supplied from a seeding agent adjusting device 5 through a conduit 6 into the pipe line 4 and then stirred at a high speed in a stirring tank 7 by a stirring blade 9 driven for rotation by a motor 8 , thereby producing magnetic micro flocs of several hundred micrometers.
[0023] Thereafter, a polymer reinforcing agent or the like is supplied from a polymer agent adjusting device 11 through a conduit 12 into a pipe line 10 and then stirred slowly at a low speed by a stirring blade 15 driven for rotation by a motor 14 in a stirring tank 13 , whereby the magnetic micro-floc groups are entangled and agglomerated by the polymer reinforcing agent to produce a pretreated water 17 containing magnetic flocs 16 (not shown in FIG. 1 ) having a size on the order of several millimeters.
[0024] A transparent tube for allowing passage of ultraviolet rays therethrough from the side of the atmosphere, for example a glass tube 74 , is immersed into the pretreated water in the stirring tank 13 , and a sterilizing ultraviolet lamp 74 connected to a power source 72 by a wire 73 is inserted into the glass tube 71 to apply ultraviolet rays into the pretreated water. In the stirring tank 13 , the pretreated water is mixed all over by the stirring blade 15 and hence, the ultraviolet rays are applied even to bacteria, e.g., colon bacilli, on the back side of the produced flocs as viewed from the side of the ultraviolet lamp as the flocs move, whereby the pretreated water is sterilized. Here, the pretreated water is mixed for several minutes and hence, is constantly irradiated with the ultraviolet rays. In the stirring tank 13 , polluted particles are taken into the magnetic flocs, whereby the transparency of the pretreated water is increased, and the ultraviolet rays from the ultraviolet lamp are transmittable through the entire region of the pretreated water. Therefore, most of the colon bacilli which have not been taken into the flocs are killed, and the living colon bacilli in the treated water are remarkably decreased. The pretreated water is moved all over to the vicinity of the ultraviolet lamp by the stirring blade and hence, the ultraviolet lamp having a weaker illumination intensity and a smaller power consumption can be used, leading to an effects of reducing the lamp cost and a sterilizing operational cost.
[0025] The pretreated water 17 thus produced is passed through a conduit 18 into a membrane separator 19 . The structure of the membrane separator 19 will be described below with reference to FIGS. 2, 3 . A net 21 serving as a membrane with openings having an opening size of from several micrometers to several ten micrometers and made of a small-gage wire of stainless steel, a small-gage wire of copper, polyester fibers or the like is mounted on an outer peripheral surface of a rotary drum 20 shown in FIG. 3 . The pretreated water flows into a water tank 22 and is passed through the net 21 into the drum 20 . At this time, the magnetic flocs 16 in the pretreated water are caught on an inner surface of the net 21 , and the water passed through the net 21 with the magnetic flocs separated therefrom is discharged in the form of purified water through an opening 23 shown in FIG. 1 , passed through a pipe line 24 , accumulated in the washing water tank 25 , and discharged to outside the system or stored in the life waste water tank in the ship. A power for the pretreated water to pass through the net 21 is a difference in surface level between the pretreated water 17 and the purified water in the drum 20 .
[0026] The colon bacilli in the pretreated water which could not be filtered in the net 21 remain in the treated water, but most of the colon bacilli are dead. Bacteria and organic substances having a size equal to or larger than 0.1 μm in the life waste water have been taken into the magnetic flocs and little remain in the treated water filtered by the net 21 . Thus, as there is only little living colon bacilli remaining in the treated water, and as the amount of nutriments in the treated water has been remarkably decreased, it is possible to substantially prevent the living colon bacilli from being proliferated within a period of storage of the treated water. Therefore, the treated water is note deteriorated, may maintain the water quality which met the discharge water standard at the time of the treatment, and may be discharged to the outside of the ship even after being stored.
[0027] The magnetic flocs 16 are filtered by the net 21 and deposited on its outer surface rotated in a counterclockwise direction as viewed in FIG. 2 , and exposed in the form of a deposit to the atmosphere above the liquid surface. The purified water in the washing water tank 25 of FIG. 1 is pressurized and fed through a conduit 27 to a shower pipe 28 by a pump 26 , and shower water is sprayed from apertures to the outer surface of the net 21 from the inner surface side of the net 21 . The magnetic flocs 16 accumulated on the outer surface of the net 21 are peeled off by the shower water, and the surface of the net 21 is regenerated. The magnetic flocs washed off stay on the surface of the pretreated water 17 in the water tank 22 .
[0028] A rotary magnet 29 ( FIG. 1 ) used as a magnetic field generating means for the magnetic separation has a construction in which a plurality of permanent magnet elements 31 are fixed by an adhesive or the like into a plurality of grooves in an outer surface of a rotor 30 ( FIG. 2 ) made of a non-magnetic material and the rotor 30 is rotated at a controlled rotational speed by a motor 32 ( FIG. 3 ).
[0029] On the other hand, as shown in FIG. 3 , a sludge transferring rotor 33 made of a non-magnetic material and used for transferring the magnetic flocs magnetically separated off is rotated at a control rotational speed through a shaft 34 by a motor 35 . At one end, the shaft 34 is supported on a wall of the water tank 22 by a rotary support 36 having a water-tightness, and at the other end, an outer periphery of the rotor 33 is supported on the wall of the water tank 22 through a rotary support 37 also having a water-tightness, wherein the inside of the rotary support 37 is opened to the atmosphere. The magnet 29 shown in FIG. 11 is inserted into the inside of the rotor 33 from the side of the rotor 33 opened to the atmosphere, and is placed in proximity of a location where the magnetic floc 16 groups washed off by washing water are staying, i.e., a location closer to the rotary drum.
[0030] In this embodiment, the rotors 33 and 30 are arranged with their axes offset from each other. Although not shown in the figures, the magnet 29 is fixed to a portion of the water tank 22 by bolts or the like, so that it is positioned at a predetermined location. The rotational directions of the rotors 33 and 30 are the same, and the rotors 33 and 30 are rotated in the direction for moving the magnetic floc groups magnetically attracted thereto toward the atmosphere side. The numbers of rotation of the rotors 33 , 30 may be the same or different. In the case of this embodiment, the rotation speed of the rotor 30 on the magnet side is larger than that of the rotor 33 .
[0031] The magnetic floc 16 groups washed down and staying in the vicinity of the water surface are attracted and moved toward the magnet side by the magnetic field of the magnet 29 , attach to the outer surface of the rotor 33 rotated outside the magnet 29 , and thereafter are exposed to the atmosphere with the rotation of the rotor 33 . A surplus amount of water in the magnetic floc 16 groups flows down the surface of the rotor 33 by gravitation, and the magnetic floc 16 groups are further concentrated. Here, the water content of the magnetic flocs is lowered to about 97%.
[0032] The magnetic floc groups concentrated on the surface of the rotor 33 are moved by the rotation of the rotor 33 . At this time, the axes of the rotors 30 , 33 get gradually away from the magnet 29 , since they are misaligned from each other, whereby the magnetically attracting force is rapidly decreased as they are more apart from the magnet. The magnetic floc 16 groups are peeled off from the surface of the rotor 33 by a spatula 38 supported on a portion of the water tank 22 to scrape off them, drop into a sludge recovery tank 39 by gravitation, and are collected as a sludge.
[0033] The sludge discharged is introduced through a pipe line 40 into a dewatering device 41 such as a centrifugal separator, a belt press or the like, where the sludge is concentrated into a water content equal to or lower than about 85% enough to prevent water to be leaked from the sludge during transportation of the sludge, or to a water content of a bout 75% enough to permit the activation of microorganisms for decomposing organic substances at the time of composting. The sludge of a high concentration is fed through a pipe line 42 into a sludge tank 43 and stored.
[0034] Treated sewage dewatered in the dewatering device is fed through a pipe line 44 into a sewage treating tank 45 , pressured by a pump 46 , then returned through a pipe line 47 to the raw water tank 1 , and introduced again into the pretreating step. With regard to an operation control unit 48 , a surface level, turbidity, temperature, a pH value and the like of the raw water are detected by a sensor 49 , and the information is transmitted through a signal line to the operation control unit 48 . Amounts of chemicals (the pH adjuster, the magnetic powder, the flocculating agent) to be added, which are optimal to produce good magnetic flocs, are calculated based on the information using an optimal amount calculating program previously inputted, and the resulting control information is transmitted via a signal line 51 to a chemical agent tank 5 for addition of the optimal amounts.
[0035] Further, a number of rotation of the stirring motor and a time period of staying in the stirring tank are calculated in the operation control unit 48 , and the resulting control information is transmitted via a signal line 52 to the motor 8 to rotate the stirring blade 9 at the optimum rotation speed and is transmitted via a signal line 53 to control a discharge rate of the pump 3 which decides the staying time in the stirring tank. Furthermore, an adding amount of a chemical (high molecular polymer) optimal to produce good magnetic flocs is calculated with the optimal amount calculating program previously inputted, and the resulting control information is transmitted via a signal line 54 to the chemical agent tank 11 to add the optimum amount. At the same time, a number of rotation of the stirring motor is calculated in the operation control unit 48 and transmitted via a signal line 55 to the motor 14 to rotate the stirring blade 15 at the optimum rotation speed.
[0036] In the membrane separator 19 , on the other hand, a liquid level of the pretreated water 17 in the water tank 22 is detected by a sensor 56 , and the information is transmitted via a signal line 57 to the operation control unit 48 . An optimum number of rotation of the rotary drum 20 and an appropriate rate of recovering the magnetic floc 16 groups are calculated based on the information using the optimal amount calculating program previously inputted, so that the liquid level of the pretreated water is positioned at a substantial central point of the location of placement of the magnet 29 , i.e., a point at which the average value of the magnetic field generated by the magnet 29 is maximum, and the resulting control signals are transmitted via a signal line 58 to a motor (not shown) for rotating the rotary drum and via a signal line 59 to the motor 35 , thereby controlling the motors at the optimum rotation speeds.
[0037] As can be seen from the above description, as a result of purifying the raw water such as the life waste water with the purifying system of this embodiment, the colon bacilli in the pretreated water which could not be filtered by the filter pass into the purified, treated water, but most of the colon bacilli are dead. In addition, bacteria and organic substances of a size equal to or larger than 0.1 μm in the life waste water have been taken into the magnetic flocs and hence, little remain in the treated water filtered by the filter. Therefore, the living colon bacilli scarcely remain in the treated water, nutriments in the treated water have been remarkably decreased and hence, it is possible to substantially prevent the living colon bacilli from being proliferated within a period of storage of the treated water. Thus, the quality of the treated life waste water is not deteriorated, and the effluent standard for the water quality satisfied at the time of the treatment can be maintained, leading to an effect that the treated water can be stored and then discharged to the outside of the ship.
[0038] In this embodiment, the glass tube 71 transparent to permit the transmission of ultraviolet rays therethrough from the atmosphere is inserted into the pretreated water in the stirring tank 13 , and the sterilizing ultraviolet lamp 74 is inserted into the glass tube 71 , whereby the ultraviolet rays can be emitted into the treated water. In the stirring tank 13 , the pretreated water is mixed all over by the stirring blade 15 . Therefore, the ultraviolet rays are applied even to colon bacilli on the back side of the produced flocs as viewed from the side of the ultraviolet lamp with the movement of the flocs, and the colon bacilli are killed. The mixing in the stirring tank 13 is conducted for a period of several minutes, and during this time, the ultraviolet rays are constantly applied to the pretreated water. Therefore, the sterilizing time is sufficient, a sterilizing effect is produced sufficiently even by the ultraviolet lamp having a smaller illumination intensity, and thus, most of the colon bacilli which have not been taken into the flocs are killed, leading to an effect of remarkable decreasing of the number of the living colon bacilli in the treated water.
[0039] Although the ultraviolet lamp 74 is disposed in the stirring tank 13 in this embodiment, it may be disposed in the stirring tank 7 , the membrane separator 19 or the washing water tank 25 , and even in this case, a similar effect is obtained.
[0040] In this embodiment, when the outer surface of the glass tube 71 is fouled by the treated water, resulting in a reduction in transmission of the ultraviolet rays, then the transmission can be restored by taking the glass tube 71 out of the stirring tank 13 , washing and removing the dirt. The washing and removal may be carried out automatically in the stirring tank 13 , although not shown in the figures.
[0041] The glass tube 71 and the ultraviolet lamp may be disposed in any other place as long as they do not interfere with the rotation of the stirring blade, and a plurality of glass tubes may be disposed between stirring blades, although not shown in the figures. In addition, a plurality of types of ultraviolet lamps having different frequencies and wavelengths effective for a plurality of microorganisms respectively may be disposed, although not shown in the figures.
[0042] The second embodiment of the invention is shown in FIG. 4 . This figure is different from FIG. 1 in that in place of the ultraviolet lamp 74 provided for sterilizing the colon bacilli, a predetermined amount of a chemical in a chemical agent tank 75 , for example the chemical for producing hydrogen peroxide, is added through a pipe line 76 into the stirring tank 13 . Hydrogen peroxide is produced in the pretreated water in the stirring tank 13 , by the power of active oxygen, colon bacilli which have not been taken into the magnetic flocs in the pretreated water are killed and very fine organic substances are oxidized and decomposed.
[0043] According to this embodiment, the mixing in the stirring tank 13 is conducted for a period of several minutes and during this time, the pretreated water is constantly mixed. The hydrogen peroxide is therefore spread all over in the pretreated water with no unevenness of concentration caused. Further, there is a sufficient sterilizing time. Therefore, even if the amount of chemical added is controlled to the minimum, a sufficient sterilizing effect is obtained, and most of the colon bacilli in the pretreated water which have not been taken into the flocs are killed, leading to an effect of remarkable decreasing of the number of the living colon bacilli in the treated water.
[0044] In this embodiment, parts of vary fine organic substances which have not been taken into the magnetic flocs in the pretreated water are oxidized and decomposed by the oxidizing force of the hydrogen peroxide. Therefore, the residual amount of the organic substances in the treated water as nutriments for the bacteria is further decreased, leading to a further effect of preventing proliferation of the living colon bacilli in the treated water.
[0045] In this embodiment, the sterilizing chemical is added into the treated water in the stirring tank 13 , it may be added into the raw water in the raw water tank 1 , into the pretreated water in the stirring tank 7 , into the pretreated water or the treated water in the membrane separator 19 , or into the treated water in the washing water tank 25 , and in this case, a similar effect is obtained.
[0046] Although the above description has been made on the cases where the bacterium-killing treatment and the organic substance-oxidizing treatment have been carried out by providing the ultraviolet lamp and by pouring the chemical from the sterilizing agent tank, substances functioning for sterilizing and oxidizing may be produced or added by providing any suitable device other than the ultraviolet lamp, such as an ozone generating device, an electrolytic hypochlorite-generating device or a ultrasonic wave-generating device, and in this case, a similar effect is obtained.
[0047] The third embodiment of the invention is shown in FIG. 5 . Difference in this figure from the structure of the stirring tank 13 in FIG. 1 is an arrangement in which a plurality of glass tubes each having a colon bacillus-killing ultraviolet lamp 74 therein are provided, and each glass tube is equipped with an elevator for moving it upwards and downwards between a location in the water and the water surface.
[0048] The glass tubes 77 , 78 with the colon bacillus-killing ultraviolet lamp 74 mounted therein are provided within a stirring tank 13 shown in the figure. The glass tubes 77 , 78 are supported by rods 79 , 80 , respectively, which are movable between positions in the pretreated water in the stirring tank 13 and positions in the atmosphere above the water surface by elevators 81 , 82 , respectively. The movement of the rods 79 , 80 is controlled by controlling the normal and reverse rotation of, for example, gears 83 , 84 in the elevators 81 , 82 .
[0049] An outer surface of the glass tube 78 arranged within the stirring tank 13 shown in the figure may be fouled by the pretreated water after operation for a long period of time, thereby decreasing its transmission for ultraviolet rays and reducing the sterilizing performance for killing bacteria in the pretreated water around an outer periphery of the glass tube 78 . Ultraviolet ray-transmission sensors 85 , 86 for detecting a reduction in the transmission of the ultraviolet rays are mounted on the outer peripheries of the glass tubes 77 , 78 at small distances apart from the glass tubes.
[0050] When the dirt of the outer surfaces of the glass tubes is detected by the ultraviolet ray-transmission sensor 85 , 86 , this is transmitted through signal lines 87 , 88 to a control unit (not shown), and the fouled glass tubes are moved toward the atmosphere above the water surface by the elevators 81 , 82 . FIG. 5 shows the case where the glass tube 78 has been moved.
[0051] The fouling of outer surfaces, i.e., light-receiving surfaces of the ultraviolet ray-transmission sensors 85 , 86 is removed automatically by small wipers (not shown) or the like, respectively.
[0052] The outer surface of the glass tube 78 is washed automatically during its movement by a washer 89 which is adapted to wash the glass tube outer surface, for example, with water or an acidic washing liquid and a brash, and a waste liquid after the washing is returned through a pipe line 90 to the raw water tank 1 . During this movement, the ultraviolet lamp 74 is turned off.
[0053] The glass tube 78 washed stands by as it is, and after the outer surface of the glass tube 77 is fouled and a predetermined level of fouling is detected by the ultraviolet ray-transmission sensor 85 , the glass tube 78 is replaced for the glass tube 77 and inserted into the stirring tank 13 , and the ultraviolet lamp is turned on.
[0054] On the other hand, the glass tube 77 is moved upwards toward the atmosphere with the outer surface of the glass tube 77 being automatically washed during the movement, and the waste water resulting from the washing is returned through a pipe line 91 to the raw water tank 1 .
[0055] According to this embodiment, any of the ultraviolet lamps 74 in the glass tubes may be used to continuously kill bacteria in the pretreated water 17 , having an effect that the pretreated water can be sterilized without stopping the mixing operation of the stirring tank 13 .
[0056] The fourth embodiment of the invention is shown in FIG. 6 . Difference in this figure from the structures of the stirring tanks 7 , 13 in FIG. 1 is arrangements which will be described below. The blade-type stirring tank 7 is replaced by the arrangement comprising a mixing tube 93 having a ribbon-shaped turbulent flow promoting plate 92 mounted in a flow passage, a pipe line 94 and a mixing tube 95 , and the blade-type stirring tank 13 is replaced by the arrangement comprising mixing tubes 99 , 100 which are in communicate with each other through a pipe line 101 and which are each equipped in flow passages with doughnut-type ribbon-shaped turbulent flow promoting plates 96 and glass tubes 97 , 98 each having a ultraviolet lamp 74 mounted therein.
[0057] In addition, as a standby for washing the glass tubes, a mixing tube 103 equipped, in its flow passage, with a doughnut-type ribbon-shaped turbulent flow promoting plate 96 and a glass tube 102 having a ultraviolet lamp 74 mounted therein, is provided in parallel. This is put in communication with the other mixing tubes through a pipe line 104 and valves 105 , 106 as well as a pipe line 107 and a valve 108 , and further connected to a pipe line 10 and a pipe line 18 through a pipe line 109 and a valve 110 as well as a valve 111 and a pipe line 112 .
[0058] The turbulent flow promoting plates 92 , 96 in the mixing tubes mix and stir the pretreated water within the mixing tubes with an effect similar to that provided by the stirring blade within the mixing tank, and bacteria in the pretreated water are killed in a manner similar to that in the mixing tank 13 by the application of ultraviolet rays from the ultraviolet lamps 74 in the mixing tubes 99 , 100 and 103 . The turbulent flow promoting plates 96 provided in the mixing tubes 99 , 100 and 103 are stationary, and flowing fluid is stirred and mixed by the disturbance provided by the ribbon-shaped turbulent flow promoting plates.
[0059] The outer surfaces of the glass tubes 97 , 98 and 102 disposed in the mixing tubes 99 , 100 and 103 are fouled with the operation and need washing. FIG. 16 shows a case where the glass tube 98 within the mixing tube 100 is washed.
[0060] In this case, the valve 113 in the pipe line 10 is opened, the valve 105 is closed, the valve 108 is opened, the valve 106 is closed, the valve 110 is closed, and the valve 111 is opened. In this case, the pretreatment is carried out by the mixing tubes 99 , 103 . The glass tube 98 in the mixing tube 100 which is to be washed is moved by an elevator (not shown), and the outer surface of the glass tube 98 is washed automatically by a washer 121 having air-tightness. The mixing tubes 99 , 103 are provided with washers 114 , 115 , respectively. Washing water flows through pipe lines 116 , 117 , 118 and 119 back to the raw water tank 1 .
[0061] After the washing of the outer surface of the glass tube 98 , it is moved into the mixing tube 100 by the elevator (not shown), the ultraviolet lamp is turned on, the valves 108 , 110 and 111 are closed, while the valve 106 is opened, and the ultraviolet lamp 74 in the mixing tube 103 is turned off.
[0062] When the glass tube 97 in the mixing tube 99 is to be washed, the valves 113 and 111 are closed, while the valves 105 , 110 and 120 are opened, the ultraviolet lamp 74 in the mixing tube 103 is turned on, while the ultraviolet lamp 74 in the mixing tube 99 is turned off, the glass tube 97 is moved by an elevator (not shown), and the outer surface of the glass tube 97 is washed automatically by the washer 114 having air-tightness.
[0063] After the washing of the glass tube 97 , it is moved into the mixing tube 99 by the elevator (not shown), the ultraviolet amp is tuned on, the valves 113 and 106 are opened, while the valves 105 , 110 and 120 are closed, and the ultraviolet amp 74 in the mixing tube 99 is turned off. To wash the glass tube 102 in the standby mixing tube 103 , the valves 105 , 108 , 110 and 111 are closed, the ultraviolet amp 74 in the mixing tube 103 is turned off, the glass tube 102 is moved by an elevator (not shown), and the outer surface of the glass tube 102 is washed automatically by the washer 115 having air-tightness. After the washing, the glass tube 102 is moved into the mixing tube 103 by the elevator (not shown).
[0064] In this embodiment, the pretreated water is mixed all over in meandering flows generated by the turbulent flow promoting plates in the mixing tubes. Therefore, ultraviolet rays from the ultraviolet lamps in the central glass tubes are applied all over to the pretreated water during the mixing and stirring, and the bacteria in the pretreated water are killed reliably.
[0065] This embodiment has been described above as using the doughnut-type ribbon-shaped plate as the turbulent flow promoting plate, but porous plates may be placed as the turbulent flow promoting plates at a predetermined distance in a direction of flowing of the pretreated water. Also in this case, a similar effect is obtained.
[0066] According to this embodiment, the ultraviolet lamps 74 are placed in the mixing tubes and can be used to continuously kill the bacteria in the pretreated water 17 . Therefore, even when a mixing tube is used and the outer surface of a glass tube having a infrared lamp mounted therein is fouled, there is an effect that the pretreated water can be sterilized without stopping the mixing in the mixing tube. Although the above embodiments have been described on the case where the water to be purified is the life waste water in the ship, the water to be purified may be ballast water containing plant plankton or animal plankton or bacteria such as cholera germ, colon bacilli and intestine micrococcus and even in this case, a similar effect is obtained.
[0067] It should be further understood by those skilled in the art that although the foregoing description has been made on the embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims. | In a filtering and purifying system, bacteria in raw water are sterilized efficiently with ultraviolet rays, chemicals and the like at a pretreating step. The number of microorganisms such as bacteria remaining in the treated water is reduced remarkably, and the residue of plankton and organic substances as nutrients for bacteria in treated water is reduced by a coagulating and filtering treatment. It is thus possible to solve a problem that the treated water is deteriorated with time due to propagation of the bacteria. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to venous valve replacement and, in particular, to replacement venous valves to lower extremities and a therapeutic method of treating venous circulatory disorders.
BACKGROUND OF THE INVENTION
[0002] Chronic venous insufficiency (CVI) of the lower extremities is a common condition that is considered a serious public health and socioeconomic problem. In the United States, approximately two million workdays are lost each year, and over 2 million new cases of venous. thrombosis are recorded each year. About 800,000 new cases of venous insufficiency syndrome will also be recorded annually. Ambulatory care costs of about $2,000, per patient, per month, contribute to the estimated U.S. cost of $16,000,000 per month for the treatment of venous stasis ulcers related to CVI.
[0003] It is estimated that greater than 3% of the Medicare population is afflicted by a degree of CVI manifested as non-healing ulcers. Studies have indicated that about 40% of seriously affected individuals cannot work or even leave the house except to obtain medical care: It is estimated that 0.2% of the American work force is afflicted with CVI.
[0004] Chronic venous insufficiency arises from long duration venous hypertension caused by valvular insufficiency and/or venous obstruction secondary to venous thrombosis. Other primary causes of CVI include varicosities of long duration, venous hypoplasia and arteriovenous fistula. The signs and symptoms of CVI have been used to classify the degree of severity of the disease, and reporting standards have been published. Studies demonstrate that deterioration of venous hemodynamic status correlates with disease severity. Venous reflux, measured by ultrasound studies, is the method of choice of initial evaluation of patients with pain and/or swelling in the lower extremities. In most serious cases of CVI, venous stasis ulcers are indicative of incompetent venous valves in all systems, including superficial, common, deep and communicating veins. This global involvement affects at least 30% of all cases. Standard principles of treatment are directed at elimination of venous reflux. Based on this observation, therapeutic intervention is best determined by evaluating the extent of valvular incompetence, and the anatomical distribubon of reflux. Valvular incompetence, a major component of venous hypertension, is present in about 60% of patients with a clinical diagnosis of CVI.
[0005] Endovascular valve replacement refers to a new concept and new technology in the treatment of valvular reflux. The concept involves percutaneous insertion of the prosthetic device under fluoroscopic guidance. The device can be advanced to the desired intravascular location using guide wires and catheters. Deployment at a selected site can be accomplished to correct valvular incompetence. Percutaneous placement of a new valve apparatus provides a less invasive solution compared to surgical transposition or open repair of a valve.
[0006] The modern concept of a stent was introduced in the 1960s. Subsequently, it has been successfully incorporated in the treatment of arterioral aneurysms and occlusive disease. The use of endovascular stents represents one of the most significant changes in the field of vascular surgery since the introduction of surgical graft techniques in the early 1950s.
[0007] Initially, the dominant interest of vascular specialists was application of stents in the arterial system. The venous system and venous disease were not considered an arena for stent application. The utilization of endovascular treatment in venous disease was initially confined to the treatment of obstruction, in the pelvic veins (for CVI) as well as treatment of obstructed hemodialysis access grafts and decompression of portal hypertension (TIPS). Although these procedures enjoy widespread application, the actual number of patients involved is relatively low compared to the number afflicted with CVI and related syndrome. Thus, the necessity for therapy using endovascular technology for the treatment of venous disease arose. The prevalence of CVI and the magnitude of its impact demand development of an effective alternative therapy.
BRIEF SUMMARY OF THE INVENTION
[0008] A replacement venous valve comprises a pair of support wings and a pair of valve wings. The valve wings are designed to deploy first from a catheter deployment device and provide stability while the support wings then deploy. The valve wings support the venous valve material and the support wings maintain patency of the vein above the valve while simultaneously anchoring the location and orientation of the valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic depiction of the frame of one embodiment of a replacement valve.
[0010] [0010]FIG. 2 is a generally top perspective view of one embodiment of the replacement valve.
[0011] [0011]FIG. 3 is a schematic side section view of a replacement valve in a vein.
[0012] [0012]FIG. 4 is a schematic side view of one embodiment of the angular relationship of a replacement valve structure in a vein.
[0013] [0013]FIG. 5 is a side section view of a compressed, non-deployed replacement valve in a delivery system component.
[0014] [0014]FIG. 6 is a schematic side section view of a venous valve being localized prior to release in a vein.
[0015] [0015]FIG. 7 is a schematic side section view of the valve wing release opening of a venous valve in a vein.
[0016] [0016]FIG. 8 is a schematic side section view of the stabilizer wing release of a venous valve in a vein.
[0017] [0017]FIG. 9 is a schematic side section view of a venous valve being localized prior to release in a vein.
[0018] [0018]FIG. 10 is a schematic side section view of the valve wing release of a venous valve in a vein.
[0019] [0019]FIG. 11 is a schematic side section view of the valve wing positioning and release of the stabilizer wing in a venous valve in a vein.
[0020] [0020]FIG. 12 is a schematic side section view of the valve wing positioned and the stabilizer wing being deployed in a venous valve in a vein.
[0021] [0021]FIG. 13 is a schematic side section view of the valve wing and stabilizer wing fully deployed in a vein.
[0022] [0022]FIG. 14 is a schematic side section view of the valve functioning in position in a vein.
[0023] [0023]FIG. 15 is an assembly view of an alternate embodiment replacement valve design.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Within the field of endovascular treatment, no previous technology has effectively used a replacement valve which also acts similar to a self-righting stent in a percutaneously located assembly. Indeed, recognition of the need for such a device, system and method of employment has been lacking. Attempts at venous valve repair are not common. Indeed, minimally invasive repair or replacement procedures are quite uncommon. This is due, in part, to the poor availability of properly sized and properly designed prosthetic venous valves. U.S. Pat. No. 5,500,014 has an excellent discussion of the different attempts to provide prosthetic venous valves, and such discussion is incorporated by reference herein. For the anatomy of venous valves, an excellent reference includes Venous Valves, by R. Gottlub and R. May, published by Springer Verlag, Austria, 1986.
[0025] The inventors have devised a device, system and method of deployment for a valve assembly utilizing various materials having excellent cost, biocompatibility, and ease of use. In one embodiment, a stent is assembled having excellent length and stability characteristics, as well as an improved profile for ease of placement and automatic deployment at a deployment site. The assembly does not rely only on placement at a previous valvular site but may also be utilized either proximal or distal to the incompetent valve site due to the self-expanding and self-orienting features and improved anti-migration characteristics of the assembly.
[0026] The use of the material chosen for endovascular valve leaflet portions of the replacement valve of this assembly may be selected from a variety of biocompatible substances Whether the material is formed of elastomer, sclera, small intestine sub-mucosa (SIS), other mammalian tissue, or other suitable material, the venous stent device of this invention may serve as a substitute for deteriorated venous valves which have been altered by thrombosis or congenital hypoplasia. The valve prosthesis which self-expands similar to a stent will be percutaneously introduced with a small sized catheter delivery system, but demonstrates improved self-righting and orienting within the vein.
[0027] Justification for development of this invention is based on the incidence of venous disorders that lack adequate endovascular therapy. Patients who are treated surgically undergo a more invasive method that involves greater costs and more numerous potential complications. The minimally invasive technique of this invention will decrease length of hospital stay, lower over-all costs and permit an almost immediate return to normal activity. Indeed, it is believed that the availability of this treatment will dramatically alter the lives of many people, including those who might not have been able to undergo previous surgical techniques for the repair or replacement of damaged venous valves.
[0028] [0028]FIG. 1 is a schematic depiction of one embodiment of venous valve assembly 20 with a frame having a first support wing 21 , an opposite second support wing 24 , a first valve wing 22 with its opposite second valve wing 23 . The first interlink 25 joins the support wings 21 , 24 with the valve wings 22 , 23 at a first junction. A second interlink 26 joins the support wings 21 , 24 with the valve wings 22 , 23 at a second junction. Valve 20 is preferably of unitary, single wire construction, but alternate configurations having a plurality of wires are possible.
[0029] [0029]FIG. 2 shows a venous valve assembly 20 with a first valve leaflet or flexible sheet 30 and a second valve leaflet or flexible sheet 34 with aperture 32 between the flexible sheets. It is recognized that, in operation, aperture 32 includes trailing edge portions 35 which open and closes as valve leaflets respond to the pressure and pumping action of the blood through the valve. As shown in FIG. 3, first support wing 21 and second support wing 24 provide lateral stability by exertion of outward radial force in the form of a support ring exerting outward pressure against the inner lumenal wall 44 at a venous location for the valve. In similar manner, the valve wings 22 , 23 exert similar force in the form of a valve ring force exerted outwardly against the lumenal wall 44 , and provide similar stabilizing and self-righting advantage to the valve as will be further discussed.
[0030] [0030]FIG. 4 illustrates the approximate included angle desired between each support wing 21 and each valve wing 23 as generally about 60°+/− about no more than 10° and preferably only about +/− a maximum of about 5°, and between first valve wing 23 and second valve wing 22 as their ends push into vein wall 44 .
[0031] [0031]FIG. 5 illustrates the folding of the venous valve stent 20 to a closed position within a deployment system device 50 . It is shown how the respective valve and support wings fold compactly together in an overlapping, butterfly-like relationship.
[0032] [0032]FIG. 6 illustrates the folded venous valve stent 20 inside a delivery system device 50 , such as a catheter. FIGS. 7 and 8 further illustrate the deployment sequence of the replacement valve stent 20 in relation to a vein wall 44 . The venous valve 20 is pushed toward the delivering end of the delivery system 50 until the first valve wing 23 and the second valve wing 22 spring open and engage the vein lumenal wall 44 . The delivery system 50 is withdrawn after the venous valve wings are in the desired position. With the delivery system 50 separated from the venous valve stent 20 , the first support wing 21 and the second support wing 24 then engage the vein wall 44 .
[0033] [0033]FIGS. 9-14 are simpler schematic depictions of the steps of delivering the venous valve stent 20 into a vein. The final step illustrates the position of the venous valve stent in relation to blood flow arrows and depicts the functionality of the valve leaflets.
[0034] [0034]FIG. 15 is an assembly sequence view of another embodiment of a venous valve assembly 200 in which the first support wing 140 is conjoined with the first valve wing 150 to form half of venous valve assembly 200 . The second support wing 160 is conjoined with second valve wing 170 to form the other half of venous valve assembly 200 . The two halves are attached by connectors 180 at opposite locations on the frame. The last sequence view in this figure shows the connected halves with first valve leaflet or flexible sheet 300 and second valve leaflet or flexible sheet 340 attached to the valve wings thereby forming aperture 320 with trailing edges 350 in operation.
[0035] Because numerous modifications may be made of this invention without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the following claims and their equivalents. | A replacement venous valve comprises a pair of support wings and a pair of valve wings. The valve wings are designed to deploy first from a catheter deployment device and provide stability while the support wings then deploy. The valve wings support the venous valve material and the support wings maintain patency of the vein above the valve while simultaneously anchoring the location and orientation of the valve. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention is generally directed to a remotely located manually operable control valves for operating blasting systems and is specifically directed to a pneumatic deadman valve.
[0003] 2. Discussion of the Prior Art
[0004] Deadman valves or switches are generally well known, and are used in a wide variety of industrial applications to operate devices or to prevent the operation of such devices. In fact, the Occupational Health and Safety Organization (OSHA) requires a safety system on all abrasive blasting equipment as well as on other equipment. Such safety systems usually include what is referred to in the art as a “deadman control.” A deadman control is a device that stops the machinery when the control is released. As is well known, these controls have been implemented as mechanical, pneumatic and electric deadman controls. In general, these valves or switches require prolonged actuation or actuation by a user who for one reason or another has part of his or her attention distracted from operation of the switch. Specifically, the operator is often focused on the operation of the system and takes the operability of the valve for granted.
[0005] The deadman valves are designed to function in a fail-safe mode wherein the valve or switch is automatically in the off position when certain conditions are not met. Typically, the failure to apply operating stimulus to the valve results in an immediate signal to shutdown. In a typical operation, the pneumatic deadman control system does not shut the system down immediately because of the inherent speed a pneumatic signal. The line, which could be 100 feet long, has to depressurize or vent, as well as the air cylinders in the air blast valves. While the action of the deadman venting or signal to shutoff is immediate, the time response from the air blast valve(s) is proportional to the length of signal line and the volume of the actuating cylinder or volume.
[0006] Such switches and valves are provided in many industrial applications such as blasting systems, power tools, industrial equipment and machinery and the like. The deadman valves are designed to prevent movement of the control device when the operator's attention is distracted from such a device. These valves permit operation of the device only when they are engaged and otherwise prevent the transmission of electrical, pneumatic, or hydraulic power to valves and other devices required to operate the machine.
[0007] The standard deadman valve comprises a simple push-button switch which is spring biased into its open position and which must be depressed into its actuated or closed position permitting operation of the device on which it is mounted. The typical valve is difficult to depress for extended periods of time because of fatigue.
[0008] One type of actuator for a deadman valve is the “mushroom” switch which requires less accurate positioning of the operator's hand. Another widely used configuration is the use of a control lever which is connected to the device on which the switch is mounted and which extends over the switch by a substantial distance and which may thus be more easily actuated. One such control lever is disclosed in U.S. Pat. No. 4,270,032, which issued to Dobberpuhl on May 26, 1981. The device is operated by deflecting the control lever against the biasing force of a return spring into contact with the switch, thus depressing and closing the switch and permitting operation of the machine. When the operator's hand is removed from the lever, the lever is returned to its initial position under the biasing force of the return spring, thus opening the switch and deactivating the device. Movement of the control lever in both directions is limited by a return stop.
SUMMARY OF THE INVENTION
[0009] The subject invention is directed to a pneumatic deadman valve for use in connection with pneumatic blasting equipment. It is an important feature of the invention that the lever actuated valve is ergonomically designed to reduce fatigue and strain on the operator. Specifically, the valve shaped to fit comfortably in the hand of the operator, with the spring biased lever hinged for action to fit the natural movement of the hand. The detent button is sized and positioned for easily accommodating single-handed operation.
[0010] In the preferred embodiment of the invention, the pneumatic deadman valve comprises a base having a supply port, typically air supply and a signal port, with the valve mechanism being positioned between the ports to control on and off flow. In operation, flow will occur in both directions through the signal port. ON refers to flow towards the blast unit. OFF refers to flow away from the blast unit and vented under the handle or lever through the cartridge spool assembly. When the valve is engaged, the flow passes therethrough to activate the system. When the valve is released, it automatically shuts off flow to the outlet or signal port and vents the volumes connected to the signal port to atmospheric through the base, the cartridge, and the spool. Thus, allowing the hoses and valves in communication with the outlet or signal port to release pressure. Thereby, allowing the abrasive air blast valves to shut off The base is designed to be comfortably held in one hand. The valve system includes a detent mechanism positioned in the base such that it may be engaged and depressed with a finger or thumb of the same hand holding the base. This can vary depending on the placement of the various lines or hoses connected to the valve. The actuator lever is sized to fit comfortably in the hand, with the hinge mechanism positioned at the wrist end of the hand, providing a natural movement for hand when depressing and engaging the lever, for reducing stress and fatigue. The spring for the detent button also acts indirectly through the taper on the detent button to push the handle or lever back up. The spool inside the cartridge utilizes pressure to push it up or to the OFF or vented position.
[0011] The resulting valve is an ergonomic configuration increasing the comfort level of the operator without sacrificing any functional features of the system.
[0012] In the preferred embodiment of the pneumatic deadman valve of the subject invention, the base is approximately 5.75-6.00 inches in length and between 0.75 and 1.400 inches in width for comfortably fitting in the palm of the average human hand. The actuator lever is approximately 5.00 inches long and 1.50 inches in width. The detent mechanism is a raised, rounded button approximately 0.50 inches in diameter. The full stroke of the lever is approximately 0.50 inches at the outboard end furthest from the hinge. The hinge is positioned between the detent button and the port end of the base.
[0013] Another important feature of the deadman valve of the subject invention is the reconfiguration of the valve cartridge with an offset port to produce a cyclonic flow around the spool, thereby reducing the wear on the spool, minimizing dead flow zones, and minimizing pressure drop.
[0014] The resulting valve is comfortable to handle and easy to use with single hand operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates the valve in a typical installation.
[0016] FIG. 2 is a perspective view of the valve of the subject invention.
[0017] FIG. 3 is similar to FIG. 2 with the actuator lever removed.
[0018] FIG. 4 is an exploded perspective view of the valve assembly.
[0019] FIG. 5 is a cross-sectional view of the valve cartridge and spool.
[0020] FIG. 6 is a cross-sectional view of the valve cartridge with the spool removed.
[0021] FIG. 7 is a cross-sectional view of the valve assembly, showing the cartridge installed therein.
DETAILED DESCRIPTION
[0022] The deadman valve of the subject invention generally comprise a base 10 having a supply port 12 and a signal port 14 at one end, with a hinge pin 20 mounted in the base near said one end. A typical installation is shown in FIG. 1 . The cylinder 11 is where the blast nozzles is attached. The large hose 13 , below the base 10 is the blast hose where the abrasive and air mixture is conveyed from the air blast unit to the blast nozzle. The small hoses 15 and 17 are the supply and signal lines to the air blast unit, respectively.
[0023] A lever handle 18 is connected to the hinge and movable about the hinge between an outward VENT position and an inward ON position. A valve cartridge 22 is housed in the base 10 and is in communication with the supply and signal ports, the valve cartridge including a spool 23 movable between an ON and a VENT position for opening flow between the supply and signal port and venting pressure through the signal port. The spool includes an actuator tip 24 which is in engagement with the handle 18 , whereby movement of the handle relative to the base 10 and cartridge 22 permits the spool to move between the ON and vent positions. A detent lock in the form of a spring return detent button 16 is mounted in the base 10 for fail-safe locking the lever handle and the spool in the closed or vent position. The detent is to prevent the valve from turning ON inadvertently. When the detent button is depressed, it will clear the way for the lever to swing down and push the spool to turn ON the system. If the handle 18 or lever is released, the detent button spring 28 will push the handle up thus allowing air pressure to push the spool 23 up or away from the base and vent the signal line to shut off air blast valves. The venting occurs through the cartridge 22 and spool 23 and under the handle 18 or lever.
[0024] In the preferred embodiment, the cartridge is located in the base between the hinge and the detent button. Preferably, the detent button is positioned such that it may be engaged without removing the hand from the base and handle, using the thumb or a finger.
[0025] It is desirable that the spool is designed to move axially relative to the cartridge, wherein the spool is of an hourglass shape for maximizing flow through the valve. In the preferred embodiment, the cartridge includes a flow port 42 in communication with the spool, wherein the flow port is off-center from the central axis of the spool and cartridge. More specifically, the spool and cartridge assembly includes a generally cylindrical cartridge having an internal bore, with the spool axially movable between the ON position and the OFF position in the central bore of the cartridge. The flow port in the cartridge is in communication with the spool, the flow port being off-center from the central axis of the spool and cartridge.
[0026] With specific reference to FIGS. 1-3 , it can be seen that the valve assembly of the subject invention includes an elongated base or body 10 having an integral supply port 12 and an integral signal port 14 . A spring return detent button 16 is positioned on the side of the base. An actuator lever 18 is hingedly mounted on the base by a hinge pin 20 , located near the port end of the body. As better shown in FIG. 3 , the valve cartridge 22 is positioned in the base with the spool 23 and tip 24 pressure-biased upwardly against the lever for normally holding the valve in an upward, vent or OFF position. The spool utilizes pressure to return it to the vent position when not depressed by lever. Force is created by pressure differential between the bottom and top (button and atmospheric) side of the spool. The spring 28 behind the detent button 16 pushes the button outward; thereby, pushing the handle 18 back up to allow spool 23 to lift and allow the signal port 14 to vent. The spring biased detent button 16 engages the lower edge 26 of the lever to lock the lever in this upward position.
[0027] The valve, as shown in FIGS. 2-4 , is designed to be held in the right hand with the palm on the lever 18 and the wrist toward the ports 12 and 14 . This permits the operator to engage the detent button 16 without removing his palm and fingers from the lever and base, thus permitting single-handed operation. It should be noted that in common practice, air blast operators, use two hands to securely operate and handle the air blast nozzle.
[0028] By placing the hinge 20 between the ports 12 , 14 and the detent button 16 , the valve is activated by a natural squeezing motion, making the valve more comfortable to operate and reducing fatigue. The cartridge 22 is seated in the valve body 10 in receptacle 30 . A pair of o-ring seals 31 , 32 provide a seal between the cartridge 22 and the body 10 . The spool 23 includes an outer tip 24 which is in contact with the actuating lever. A pair of spool seals 34 , 36 are provided between the spool and the cartridge.
[0029] In the preferred embodiment, the base is approximately 5.75-6.00 inches in length and between 0.75 and 1.400 inches in width for comfortably fitting in the palm of the average human hand. The actuator lever is approximately 5.00 inches long and 1.50 inches in width. The detent mechanism is a raised, rounded button approximately 0.50 inches in diameter. The full stroke of the lever is approximately 0.50 inches at the outboard end furthest from the hinge.
[0030] It is another important aspect of the invention that the cartridge and spool assembly has been reconfigured to minimize wear on the spool and extend the life of the valve. Turning now to FIGS. 4 , 5 and 6 , it can be seen that the spool 23 is generally of an hourglass configuration with the narrow mid-section 40 designed to move into and out of communication with the cartridge port 42 as the spool moves axially in the cartridge when engaged and released by the lever 18 . It should be noted that port 42 is always in communication with port 14 , the signal line. When the spool is up or towards the handle, signal port is communicated to atmospheric. When the spool is depressed by handle, port 42 is in communication with port 12 allow flow to turn on valves at air blast unit.
[0031] The hour glass cross-section permits maximum flow for the size of the valve bore. As best seen in FIG. 6 , the port 42 is off-center. This creates a cyclonic flow around the hourglass spool, reducing wear on the spool by distributing the force generated by the pressure flow through the cartridge port.
[0032] The pneumatic deadman valve of the subject invention is ergonomically designed to reduce stress and fatigue experienced by the operator. Further, the flow system of the valve has been reconfigured to maximize flow and reduce wear on the valve spool. While certain embodiments and features of the invention have been described in detail herein, it will be recognized that the invention encompasses all modifications and improvements within the scope and spirit of the following claims. | A lever actuated pneumatic deadman valve for use in connection with pneumatic blasting equipment is ergonomically designed to reduce fatigue and strain on the operator. The valve is shaped to fit comfortably in the hand of the operator, with a spring biased lever hinged for action to fit the natural movement of the hand. A detent button is sized and positioned for easily accommodating single-handed operation. Another important feature of the deadman valve is the reconfiguration of the valve cartridge with an offset port to produce a cyclonic flow around the spool for reducing the wear on the spool. | 5 |
FIELD
[0001] An embodiment of the invention relates generally to a cart for storage and transport of components. More particularly, the invention relates to an A-frame cart that can be extended and collapsed both lengthwise and across its width and that can be configured using interchangeable brackets to accommodate different storage and transport requirements of objects having different shapes and sizes.
BACKGROUND
[0002] Carts are a primary device for storing and transporting components or other objects. Since there are all sorts of different components that vary greatly in size and shape, there are also a great variety of carts available having different sizes and configurations intended to meet different component size and shape requirements. Generally, as components become larger and require more specific mounting methods, a cart intended to store and transport the larger components becomes proportionately larger and bulkier, and the cart also tends to be more specialized thereby limiting its use for components other than the components for which it is intended. Such larger carts also have limited maneuverability and take up a larger amount of space in storage areas both during and between uses.
[0003] Platform carts, which are sometimes referred to as platform trucks, are widely used due to their ability to store a variety of components. Platform carts come in a variety of sizes and configurations including basic flat platform carts, panel movers, deep retaining wall platform trucks, folding handle platform trucks, bar cradle trucks, bar and pipe trucks, luggage trucks, and the like and are typically ‘general purpose’ in that they are not designed for specific components although they may have certain features useful for certain types of components. For example, such carts may include uprights to support sheets of paneling or plywood, cradles for holding different sizes of piping, etc. but are not designed for a specific size of paneling or plywood, size of piping, etc. Generally, the components stored and transported in such platform carts merely sit at rest atop the platform and, for certain carts, may lean against an upright or be otherwise constrained by a retaining wall, a cradle, posts, etc. But, such carts typically provide no method for any specialized mounting or capturing of specific components to include sensitive components.
[0004] In order to reliably store and transport specific components, custom carts must be designed and manufactured that meet mounting requirements of the specific components. Custom designed carts tend to be costly and their specialized characteristics can result in a large number of custom carts that collectively require a significant amount of storage space.
[0005] Therefore, there is a need for an improved cart for storage and transport of components.
SUMMARY
[0006] According to one aspect of invention, there is provided a stable extendable apparatus to receive an attachable component. The apparatus includes a top structure, a bottom structure, a front structure and a rear structure. The top structure includes at least one extendable top member which defines a minimum length of the apparatus in a longitudinal retracted position and a maximum length of the apparatus in a longitudinal extended position. The front structure is coupled to the top structure. The front structure includes a first front side support, a second front side support, and an extendable front cross-support to couple the first and second side supports together. The extendable cross-support defines a minimum width of the apparatus in a lateral retracted position and a maximum width of the apparatus in a lateral extended position. Extension or retraction of the extendable front cross-support changes an angle of orientation of the first front side support relative to the second front side support.
[0007] The bottom structure is coupled to the front structure and opposed to the top structure. The bottom structure includes at least one extendable bottom member which corresponds in length with the extendable top member. The rear structure is coupled to the top structure and bottom structure. The rear structure includes a first rear side support, a second rear side support, and an extendable rear cross-support to couple the first and second rear side supports together. Extension or retraction of the extendable rear cross-support changes an angle of orientation of the first rear side support relative to the second rear side support. The first rear side support, the second rear side support, and the extendable rear cross-support correspond to positions of the first front side support, second front side support, and extendable front cross-support, respectively.
[0008] According to another embodiment of an embodiment of the invention, the apparatus includes a support arm attachable to the top structure and the bottom structure. The support arm may provide secondary support to the apparatus. The support arm may also include a plunger spring system to attach the support arm to the top and bottom structures. The support arm may also define a plurality of mounting holes to receive a respective amount of brackets.
[0009] According to further embodiment of an embodiment of the invention, the first front side support, the second front side support, the first rear side support, and the second rear side support define a plurality of mounting holes to receive a respective amount of brackets.
[0010] According to another embodiment of an embodiment of the invention, the bottom structure includes at least one moving device to move the apparatus. The moving device may include but is not limited to wheels, tires, or the like.
[0011] According to another embodiment of an embodiment of the invention, wherein the extendable front cross-support, extendable rear cross-support, extendable top member, and extendable bottom member each include a first tubing and a second tubing. The first and second tubings are insertable respectively into each other. The first and second tubings may have different cross sections or diameters so that the tubings can slide past each other. Further, the extendable front cross-support, extendable rear cross-support, extendable top member, and extendable bottom member may each further have a locking device to lock and unlock the first tubing to the second tubing. The locking device may be a quick-release pin.
[0012] According to another embodiment of an embodiment of the invention, the apparatus includes a stand or a cart, such as an A-Frame cart for storage and transport of components. An embodiment of the invention includes an A-frame cart that provides a strong, lightweight, and adjustable solution to the mounting and restraining of different components having a variety of shapes and sizes, and also accommodates special mounting requirements. The A-frame cart employs a telescopic structural-tubing design that enables the cart to be extended and collapsed both lengthwise and across its width, thereby allowing the cart to be extended to a larger size in order to accommodate larger components while being able to be collapsed to a smaller size to accommodate smaller components and also to reduce its space requirements between uses. The A-frame cart also includes a variable-position vertical support arm that allows the cart to conform to mounting requirements of smaller sized components. The A-frame cart has an interchangeable mounting bracket design that allows for the attachment of generic support brackets as well as specialized brackets designed to meet mounting requirements of specific components. Mounting holes for brackets can be found the entire length of the vertical support bars, allowing for a great number of brackets to be attached concurrently. The cart rests on wheels that enable mobility.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The subject matter of the application will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
[0014] FIG. 1A depicts an exemplary A-frame cart having been collapsed in both width and length in accordance with a first embodiment of the invention;
[0015] FIG. 1B depicts the exemplary A-frame cart of FIG. 1A having been extended in width;
[0016] FIG. 1C depicts the exemplary A-frame cart of FIG. 1A having been extended in width and in length
[0017] FIG. 1D depicts the different parts of the exemplary A-frame cart of FIGS. 1A-1C ;
[0018] FIG. 1E depicts a side view of the exemplary A-frame cart of FIGS. 1A-1C ;
[0019] FIG. 1F depicts an end view of the exemplary A-frame cart of FIGS. 1A-1C ;
[0020] FIG. 1G depicts a top view of the exemplary A-frame cart of FIGS. 1A-1C ;
[0021] FIGS. 2A-2C depict enlarged views of the circled areas A-C of FIG. 1D ;
[0022] FIG. 2D depicts a cross-sectional view of cross-section DD of FIG. 1E ;
[0023] FIG. 2E depicts an enlarged view of the circled area E of FIG. 1E ;
[0024] FIG. 2F depicts an enlarged view of the circled area F of FIG. 1F ;
[0025] FIG. 2G depicts a cross-sectional view of cross-section GG of FIG. 1G ;
[0026] FIGS. 2H-2J depict enlarged views of the circled areas H-J of FIG. 2G ;
[0027] FIGS. 2K-2M depict enlarged views of the circled areas K-M of FIGS. 1E and 2D ;
[0028] FIGS. 3A-3C depict top, side, and isometric views of an exemplary top frame in accordance with an embodiment of the invention;
[0029] FIG. 3D depicts an exemplary rotational stop in accordance with an embodiment of the invention;
[0030] FIG. 3E depicts an exemplary cross frame in accordance with an embodiment of the invention;
[0031] FIG. 3F depicts and exemplary rear male limiting collar in accordance with an embodiment of the invention;
[0032] FIG. 3G depicts an end view of an exemplary front offset support in accordance with an embodiment of the invention;
[0033] FIG. 3H depicts a cross-sectional view of cross-section AA of FIG. 3G ;
[0034] FIG. 3I depicts an exemplary top plunger in accordance with an embodiment of the invention;
[0035] FIG. 3J depicts an exemplary rotational collar in accordance with an embodiment of the invention;
[0036] FIG. 3K depicts an isometric view of an exemplary top vertical frame support in accordance with an embodiment of the invention;
[0037] FIG. 3L depicts an end view of the exemplary vertical frame support top of FIG. 3K ;
[0038] FIG. 3M depicts a cross-sectional view of cross-section AA of FIG. 3L ;
[0039] FIG. 3N depicts a side view of the exemplary top plunger of FIG. 3I ;
[0040] FIG. 3O depicts a cross-sectional view of cross-section EE of FIG. 3N ;
[0041] FIG. 4A depicts a cross-sectional view of cross-section AA of FIG. 3B ;
[0042] FIG. 4B depicts an enlarged view of the circled area B of FIG. 4A ;
[0043] FIG. 4C depicts a cross-sectional view of cross-section CC of FIG. 3A ;
[0044] FIG. 4D depicts an enlarged view of the circled area D of FIG. 4C ;
[0045] FIGS. 5A , 5 B, and 5 C depicts different side views and an isometric view of an exemplary side support in accordance with an embodiment of the invention;
[0046] FIG. 6A depicts an exemplary frame side support in accordance with an embodiment of the invention;
[0047] FIG. 6B depicts an enlarged view of the circled area A of FIG. 5A ;
[0048] FIG. 6C depicts an exemplary front male limiting collar in accordance with an embodiment of the invention;
[0049] FIG. 6D depicts an exemplary rotational collar in accordance with an embodiment of the invention;
[0050] FIGS. 7A and 7B depict side and isometric views of an exemplary an extendable top or bottom member in accordance with an embodiment of the invention;
[0051] FIG. 8A depicts a cross-sectional view of cross-section AA of FIG. 7A ;
[0052] FIG. 8B depicts an exemplary rear frame tubing in accordance with an embodiment of the invention;
[0053] FIG. 8C depicts an exemplary rear tube stopper in accordance with an embodiment of the invention;
[0054] FIG. 9 depicts an exemplary rear cross frame in accordance with an embodiment of the invention;
[0055] FIGS. 10A , 10 B, and 10 C depict different side views and an isometric view of an exemplary rear side support in accordance with an embodiment of the invention;
[0056] FIG. 11A depicts an exemplary frame side support in accordance with an embodiment of the invention;
[0057] FIG. 11B depicts an enlarged view of the circled area A of FIG. 10A ;
[0058] FIG. 11C depicts an exemplary rear female limiting collar in accordance with an embodiment of the invention;
[0059] FIG. 11D depicts an exemplary rear side support collar in accordance with an embodiment of the invention;
[0060] FIG. 12 depicts an isometric view of an exemplary middle wheel mount in accordance with an embodiment of the invention;
[0061] FIG. 13A depicts an exemplary wheel mounting plate in accordance with an embodiment of the invention;
[0062] FIG. 13B depicts a side view of the exemplary middle wheel mount of FIG. 12 ;
[0063] FIG. 13C depicts a cross-sectional view of cross-section AA of FIG. 13B ;
[0064] FIG. 14 depicts an exemplary front support in accordance with an embodiment of the invention;
[0065] FIG. 15A depicts an end view of the exemplary front support of FIG. 14 ;
[0066] FIG. 15B depicts a side view of the exemplary front support of FIG. 14 ;
[0067] FIG. 15C depicts an exemplary male cross support in accordance with an embodiment of the invention;
[0068] FIG. 16 depicts an exemplary rear cross support in accordance with an embodiment of the invention;
[0069] FIG. 17A depicts an end view of the exemplary rear cross support of FIG. 16 ;
[0070] FIG. 17B depicts a side view of the exemplary rear cross support of FIG. 16 ;
[0071] FIG. 17C depicts a cross-sectional view of cross-section AA of FIG. 17B ;
[0072] FIG. 17D depicts an isometric view of an exemplary folding sleeve insert in accordance with an embodiment of the invention;
[0073] FIG. 17E depicts a side view of the exemplary folding sleeve insert of FIG. 17D ;
[0074] FIG. 17F depicts an end view of the exemplary folding sleeve insert of FIG. 17D ;
[0075] FIG. 18 depicts another exemplary rear cross support in accordance with an embodiment of the invention;
[0076] FIG. 19A depicts an end view of the exemplary rear cross support of FIG. 18 ;
[0077] FIG. 19B depicts a side view of the exemplary rear cross support of FIG. 18 ;
[0078] FIG. 20 depicts another exemplary front support in accordance with an embodiment of the invention;
[0079] FIG. 21A depicts a side view of the exemplary front support of FIG. 20 ;
[0080] FIG. 21B depicts another side view of the exemplary front support of FIG. 20 ;
[0081] FIG. 21C depicts a cross-sectional view of cross-section AA of FIG. 21B ;
[0082] FIG. 22 depicts an isometric view of an exemplary outer wheel mount in accordance with an embodiment of the invention;
[0083] FIG. 23A depicts a side view of the exemplary outer wheel mount of FIG. 22 ;
[0084] FIG. 23B depicts a cross-sectional view of cross-section AA of FIG. 23A ;
[0085] FIG. 24 depicts an isometric view of an exemplary shelf post in accordance with an embodiment of the invention;
[0086] FIG. 25A depicts a side view of the exemplary shelf post of FIG. 24 ;
[0087] FIG. 25B depicts an end view of the exemplary shelf post of FIG. 24 ;
[0088] FIG. 25C depicts a cross-sectional view of cross-sections AA of FIGS. 25A and 25B ;
[0089] FIG. 26 depicts an isometric view of an exemplary bottom plunger in accordance with an embodiment of the invention;
[0090] FIG. 27A depicts a side view of the exemplary bottom plunger of FIG. 26 ;
[0091] FIG. 27B depicts a cross-sectional view of cross-section AA of FIG. 27A ;
[0092] FIG. 27C depicts an isometric view of an exemplary bottom vertical frame support in accordance with an embodiment of the invention;
[0093] FIG. 27D depicts a side view of the exemplary bottom vertical frame support of FIG. 27C ;
[0094] FIG. 27E depicts a cross-sectional view of cross-section AA of FIG. 27D ;
[0095] FIG. 28A depicts a top view of an exemplary strap in accordance with an embodiment of the invention;
[0096] FIG. 28B depicts a side view of the exemplary strap of FIG. 28A ;
[0097] FIG. 29A depicts an isometric view of an exemplary bottom frame tubing in accordance with an embodiment of the invention;
[0098] FIG. 29B depicts a side view of the exemplary bottom frame tubing of FIG. 29A ;
[0099] FIG. 29C depicts a cross-sectional view of cross-section AA of FIG. 29B ;
[0100] FIG. 29D depicts a cross-sectional view of cross-section BB of FIG. 29B ;
[0101] FIG. 30A depicts an isometric view of an exemplary collapsing sleeve insert in accordance with an embodiment of the invention;
[0102] FIGS. 30B and 30C depict end and side views of the exemplary collapsing sleeve insert of FIG. 30A , respectively;
[0103] FIG. 31 depicts an isometric view of an exemplary mating collar in accordance with an embodiment of the invention;
[0104] FIG. 32A-32C depict isometric, end, and side views of an exemplary stabilator configured cart assembly in accordance with a second embodiment of an embodiment of the invention;
[0105] FIGS. 33A and 33B depict enlarged views of the circled areas A and B of FIGS. 32A and 32B ;
[0106] FIGS. 34A and 34B depict isometric views of an exemplary exterior bracket assembly in accordance with an embodiment of the invention;
[0107] FIGS. 35A-C depict isometric, end, and side views of an exemplary exterior bracket in accordance with an embodiment of the invention;
[0108] FIG. 36A depicts an isometric view of an exemplary exterior stabilator mounting bracket in accordance with an embodiment of the invention;
[0109] FIG. 36B depicts an isometric view of an exemplary exterior mounting gusset in accordance with an embodiment of the invention;
[0110] FIG. 36C depicts an isometric view of an exemplary exterior mounting rib in accordance with an embodiment of the invention;
[0111] FIG. 37 depicts an isometric view of an exemplary mount rubber insert in accordance with an embodiment of the invention;
[0112] FIGS. 38A and 38B depict top and side views of an exemplary base strap assembly in accordance with an embodiment of the invention;
[0113] FIGS. 39A and 39B depict isometric and side views of an exemplary upper strap assembly in accordance with an embodiment of the invention;
[0114] FIG. 40A depicts an isometric view of an exemplary upper strap mount in accordance with an embodiment of the invention;
[0115] FIGS. 40B and 40C depict side and top views of an exemplary upper stabilator strap assembly in accordance with an embodiment of the invention;
[0116] FIGS. 41A and 41B depict isometric views of an exemplary interior bracket assembly in accordance with an embodiment of the invention;
[0117] FIGS. 42A-C depict isometric, end, and side views of an exemplary interior bracket in accordance with an embodiment of the invention;
[0118] FIG. 43A depicts an isometric view of an exemplary interior stabilator mounting bracket in accordance with an embodiment of the invention;
[0119] FIG. 43B depicts an isometric view of an exemplary interior mounting rib in accordance with an embodiment of the invention;
[0120] FIG. 44 depicts an isometric view of an exemplary base shelving assembly in accordance with an embodiment of the invention;
[0121] FIG. 45 depicts an isometric view of an exemplary secondary base shelving assembly in accordance with an embodiment of the invention;
[0122] FIG. 46A-46C depict isometric, end, and side views of an exemplary drive shaft and tail rotor configured cart assembly in accordance with a third embodiment of an embodiment of the invention;
[0123] FIGS. 47A and 47B depict enlarged views of the circled areas A and B of FIGS. 46A and 46B ;
[0124] FIG. 48 depicts an isometric view of an exemplary top drive shaft mount assembly in accordance with an embodiment of the invention;
[0125] FIG. 49 depicts an isometric view of an exemplary top drive shaft mount in accordance with an embodiment of the invention;
[0126] FIG. 50A depicts an isometric view of an exemplary top drive mounting plate in accordance with an embodiment of the invention;
[0127] FIG. 50B depicts an isometric view of an exemplary support plate in accordance with an embodiment of the invention;
[0128] FIG. 50C depicts an isometric view of an exemplary top support brace in accordance with an embodiment of the invention;
[0129] FIGS. 51A and 51B depict side and top views of an exemplary upper drive shaft strap assembly in accordance with an embodiment of the invention;
[0130] FIGS. 52A and 52B depict isometric views of an exemplary exterior shaft bracket assembly in accordance with an embodiment of the invention;
[0131] FIG. 53A depicts an isometric view of an exemplary exterior shaft bracket in accordance with an embodiment of the invention;
[0132] FIG. 53B depicts an isometric view of an exemplary strap tab in accordance with an embodiment of the invention;
[0133] FIG. 53C depicts an isometric view of an exemplary strap retainer in accordance with an embodiment of the invention;
[0134] FIGS. 54A and 54B depict isometric views of an exemplary interior tail rotor assembly in accordance with an embodiment of the invention;
[0135] FIGS. 55A and 55B depict an isometric and an end view of an exemplary interior tail rotor bracket assembly in accordance with an embodiment of the invention;
[0136] FIG. 56 depicts an isometric view of an exemplary interior tail rotor bracket in accordance with an embodiment of the invention; and
[0137] FIGS. 57A and 57B depict side and top views of an exemplary tail rotor strap assembly in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0138] An embodiment of the invention will now be described more fully in detail with reference to the accompanying drawings are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete and will fully convey the scope of embodiments of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0139] An embodiment of the invention provides stable extendable apparatus to store and transport components. An example of such apparatus may include but is not limited to a cart, a stand, or the like. In one embodiment, the apparatus is an A-frame cart as depicted in the accompanying figures. The A-frame cart comprises telescopic structural-tubing that enables the cart to be extended and collapsed both lengthwise and across its width. The A-frame cart may include one or more variable-position vertical support arms that allow the cart to conform to mounting requirements of small components. The A-frame cart allows for the attachment of generic support brackets as well as specialized brackets designed to meet mounting requirements of specific components. Mounting holes for brackets can be found the entire length of the vertical support bars, allowing for a great number of brackets to be attached concurrently.
[0140] The cart rests on a movable device that enables mobility. An example of such movable device are wheel mechanisms. In another embodiment, the wheels comprise large run-flat caster-style tires, allowing the cart to operate on both finished and rough surfaces such as terrain. The wheels or tires may include locking mechanisms that can be locked to make the cart immobile or unlocked to allow the cart to move.
[0141] The cart may be converted into a stand. For example, the A-frame cart can also be converted to an immobile yet collapsible A-frame stand by replacing the tires with feet, legs, or other standing devices intended to enable the stand to remain in a fixed position. All the wheels or tires can be replaced with a standing device or the stand can also be configured such that a portion of the stand is fixed in place on a standing device while the extendable and collapsible portions have wheels allowing the stand to be extended and collapsed more easily. For example, an outer wheel mount 113 and an inner wheel mount 108 on one side of the stand could be replaced with legs that are fixed to a surface (e.g., bolted to a floor), where the remaining wheels could be used to extend and collapse the width and length of the stand. Additionally, if additional support is needed the portion of the rear and front cross supports 110 , 112 could be configured with tubing that would be parallel to the bottom frame tubing 129 and extendable member 104 , which could also be used to support additional wheels that would be approximately half way between the back and front wheels when the cart 100 was extended in width fully.
[0142] FIG. 1A depicts an exemplary A-frame cart 100 having been collapsed in both width and length in accordance with a first embodiment of the invention. When the A-frame cart 100 has been collapsed in both width and length, the space it requires is minimized and it is easier to maneuver.
[0143] FIG. 1B depicts the exemplary A-frame cart 100 of FIG. 1A having been extended in width as indicated by the two lateral arrows 10 . By extending the width of the A-frame cart, additional stability is achieved making it less likely to tip over onto its side.
[0144] FIG. 1C depicts the exemplary A-frame cart 100 of FIG. 1A having been extended in width and in length as indicated by the three longitudinal arrows 20 . By extending the length of the A-fame cart, larger components can be stored and transported, additional components can be stored and transported, or some combination thereof. Although the A-frame cart 100 as described herein is not able to extend or collapse its side supports or its top structure or frame (as indicated by side arrows 30 and by top arrows 40 ), one skilled in the art will recognize that the telescopic structural-tubing approach described herein could also be applied to the side supports of the A-frame cart and/or to its top frame. Moreover, the cart 100 could be configured to use a single tubing instead of a top frame comprising two tubings and a cross frame. The tubing could also be a table or platform like structure. Additionally, the top frame could have additional tubings such that instead of two parallel tubings there are three or more parallel tubings.
[0145] FIG. 1D depicts the different parts of the exemplary A-frame cart 100 of FIGS. 1A-1C . Referring to FIG. 1D , A-frame cart 100 comprises a top structure or frame 101 , four side supports (a first front side support 102 , a second front side support 102 , a first rear side support 106 , and a second rear side support 106 ), at least one extendable top member and one opposing extendable bottom member 104 , a rear cross frame 105 , two middle wheel mounts 108 , at least a first and second front support 109 and 112 , a first rear cross support 110 , a second rear cross support 111 , four outer wheel mounts 113 , twelve rotational stops 114 , two shelf posts 118 , six wheels 125 , two bottom plungers 126 , four locking spring plungers 127 , four straps 128 , two bottom frame tubings 129 , and four collapsible sleeve inserts 130 . The two bottom plungers 126 are part of two moveable side support arms that can be positioned as desired on the two bottom frame tubings 129 and frame tubing of the top structure 101 in order to accommodate components of different lengths.
[0146] The two moveable side support arms do not have to be across from each other (as shown). Additional moveable side support arms can also be used and the use of such support is entirely optional. Moreover, one skilled in the art would recognize that similar supports could be used in conjunction with the at least one extendable top member and bottom member 104 . Alternatively, fixed or moveable side supports could be configured horizontally such that they attached to the vertically oriented side support 102 . Generally, all sorts of combinations are possible for use of fixed and moveable side supports. Similarly, different combinations of cross supports extending across the bottom frame tubings 129 , the bottom member 104 , the top member 104 , and/or the top structure are possible.
[0147] The telescopic structural tubing of the cart 100 of FIGS. 1A-1C is designed where a first tubing having an outer diameter fits within a second tubing having a inner diameter sized so that the first tubing will fit within the second tubing. One skilled in the art will recognize that the telescopic structural tubing of the cart 100 could include three or more such tubing sized to fit together to provide additional telescopic capabilities. In alternate embodiments, different cross-sectional shapes of the tubing may be used including circular tubing, rectangular tubing, and the like. The telescopic structural tubing of the cart 100 of FIGS. 1A-1C could alternatively be designed such that instead of the cart having one portion that collapses into the second portion from one side, the cart could have one portion that collapses into the second portion from one side and a third portion that collapses into the second portion from the other side. As such, the cart 100 would have eight wheels instead of six.
[0148] Also depicted in FIG. 1D are three circled areas A-C, which are shown in enlarged views in FIGS. 2A-2C . An extendable front cross-support comprises the first front support 109 and the second front support 112 to couple the side supports 102 . Similarly, an extendable rear cross-support opposed to the front cross-support includes a first rear cross support 110 and a second rear cross support 111 . As can be seen in FIG. 1D , the at least one extendable top member and one opposing extendable bottom member 104 are sized such they can slide within the top and bottom structures to enable the A-frame cart 100 to be extended or collapsed along its length. Similarly, the two first front supports 109 are sized to slide within the two second front supports 112 and the second rear cross support 111 is sized to slide within the first rear cross support 110 thereby enabling the A-frame cart 100 to be extended or collapsed along its width.
[0149] FIG. 1E depicts a side view of the exemplary A-frame cart 100 of FIGS. 1A-1C . Shown are side views of the middle wheel mount 108 and the outer wheel mount 113 . Also shown is a cross section DD, and circled areas E and M, which are further depicted in FIGS. 2D , 2 E and 2 M, respectively.
[0150] FIG. 1F depicts an end view of the exemplary A-frame cart 100 of FIGS. 1A-1C . Shown is a circled area F for which an enlarged view is provided in FIG. 2F .
[0151] FIG. 1G depicts a top view of the exemplary A-frame cart 100 of FIGS. 1A-1C . Shown is a cross section GG, which is also depicted in FIG. 2G .
[0152] FIGS. 2A-2C depict enlarged views of the circled areas A-C of FIG. 1D . Referring to FIG. 2A , a quick-release pin 116 is shown partially inserted into a hole in the side of the second front support 112 . A loop-tab/lanyard/wire rope assembly 119 is depicted attached to the quick-release pin 116 . In alternate embodiments, other locking mechanisms may be used in place of the quick-release pin 116 . A pan head machine screw 120 and a flat washer 121 attaching one end of the wire rope of the loop-tab/lanyard/wire rope assembly 119 to the second front support 112 thereby allowing the quick-release pin 116 to hang loose when not inserted into the second front support 112 .
[0153] Referring to FIG. 2B , a an extendable bottom member 104 is shown inserted into a rotational stop 114 . The wheel 125 is fixed onto outer wheel mount 113 , for example using a hex head cap screw 123 , a flat washer 122 , and a locknut 124 to bolt the wheel 125 . Other fixing mechanisms may be contemplated.
[0154] Referring to FIG. 2C , a collapsing sleeve insert 130 is shown inserted into a rotational stop 114 and is also shown being attached to a mating collar 132 using flat washers 133 and pan head machine screws 134 .
[0155] FIG. 2D depicts a cross-sectional view of cross-section DD of FIG. 1E . Shown are circled areas K and L for which enlarged views are provided in FIGS. 2K and 2L , respectively.
[0156] FIG. 2E depicts an enlarged view of the circled area E of FIG. 1E , whereby a part of the top structure 101 that is extending downward is shown abutting a bottom plunger 126 .
[0157] FIG. 2F depicts an enlarged view of the circled area F of FIG. 1F , where an outer wheel mount 113 is shown in front of and substantially in line with a middle wheel mount 108 . Also shown are two shelf posts 118 beneath the two front supports 109 , where the top portion of a shelf post 118 that is behind the nearest shelf post 118 can be seen as viewed from a point slightly above the nearest shelf post 118 .
[0158] FIG. 2G depicts a cross-sectional view of cross-section GG of FIG. 1G . Shown are circled areas H, I, and J for which enlarged views are provided in FIGS. 2H-2J , respectively.
[0159] FIGS. 2H-2J depict enlarged views of the circled areas H-J of FIG. 2G , which correspond to where the wheels 125 are mounted to one side of the cart 100 . Referring to FIG. 2H , a side support 102 intersects with the bottom frame tubing near a front support 109 just above and to the right of outer wheel mount 113 . Referring to FIG. 2I , a side support 102 intersects with the bottom frame tubing near a front support 109 just above and to the right of the middle wheel mount 108 . The extendable member 104 can be seen inside a collapsing sleeve insert 130 . Referring to FIG. 2J , a rear side support 106 intersects with the extendable member 104 near a rear cross support 111 just above and to the left of the outer wheel mount 113 . A rotational stop 114 , which is intended to restrain movement, is also shown about extendable member 104 .
[0160] FIGS. 2K-2M depict enlarged views of the circled areas K-M of FIGS. 1E and 2D . Referring to FIG. 2K , the enlarged view of circled area K shows the intersection of a top portion of a moveable side support with the tubing of the top structure 101 . A portion of a cross frame of the top structure 101 can be seen behind the intersection of the side support and tubing. Referring to FIG. 2L , the enlarged view of circled area L shows the intersection of a bottom portion of a moveable side support with the bottom frame tubing 129 . A portion of a shelve post 118 and a portion of the middle wheel mount 108 can be seen behind the intersection of the side support and tubing. Referring to FIG. 2M , the enlarged view of circled area M shows a side support attached to top frame such that it can rotate next to a rotational stop 114 that restricts movement. Also shown is a portion of a collapsing sleeve insert 130 .
[0161] FIGS. 3A-3C depict top, side, and isometric views of an exemplary top structure 101 in accordance with an embodiment of the invention. Top structure 101 comprises two bottom frame tubing 129 , two cross frames 302 , and two top plungers 303 , which correspond to the top portions of moveable side supports previously described. A cross section AA is shown in FIG. 3B , which is further depicted in FIG. 4A . A cross-section CC is shown in FIG. 3A , which is further depicted in FIG. 4C . Also shown in FIGS. 3A-3C are several rotational stops 114 that can be positioned as desired to restrain movement of objects associated with the bottom frame tubing. For example, in FIG. 47A , rotational stops are used to restrain movement of top drive shaft mounts.
[0162] FIG. 3D depicts an exemplary rotational stop in accordance with an embodiment of the invention. Various sizes of rotational stops having different inside inner and outer diameters are used with an embodiment of the invention to accommodate different sized tubing. Generally, rotational stops are used alongside rotating collars and the like that rotate about the tubing making up the framing of the cart, etc. The rotational stops allow rotation necessary to collapse or extend the width of the cart 100 but restrain the collars from sliding down the tubing. Rotational stops can also be used to restrain movement of other objects attached to the tubing such as the top drive shaft mounts of FIG. 47A .
[0163] FIG. 3E depicts an exemplary cross frame 302 in accordance with an embodiment of the invention, which comprises two rear male limiting collars 306 which reside on each end of a front offset support 307 .
[0164] FIG. 3F depicts and exemplary rear male limiting collar 306 in accordance with an embodiment of the invention. The notch portion of the collar 306 allows a range of movement when used with a side support 102 , where the range of movement corresponds to the rotation of the side support relative to the tubing when the width of the cart is extended or collapsed.
[0165] FIG. 3G depicts an end view of an exemplary front offset support in accordance with an embodiment of the invention. Seen in FIG. 3G is a cross-section AA, which is shown in FIG. 3H .
[0166] FIG. 3H depicts a cross-sectional view of cross-section AA of FIG. 3G .
[0167] FIG. 3I depicts an exemplary top plunger 303 in accordance with an embodiment of the invention, which comprises a rotational collar 308 and a top vertical frame support 309 . The top plunger 303 is configured to combine with bottom plunger 126 to provide a moveable side support.
[0168] FIG. 3J depicts an exemplary rotational collar 308 in accordance with an embodiment of the invention, which includes a hole for a threaded boss 310 shown in FIGS. 3I , 3 N and 3 O.
[0169] FIG. 3K depicts an isometric view of an exemplary top vertical frame support 309 in accordance with an embodiment of the invention an embodiment of the invention. The top vertical frame support has mounting holes down its length that allow for quick-release pins to be used to support various types of attachments (e.g., brackets, straps, etc.).
[0170] FIG. 3L depicts an end view of the exemplary top vertical frame support 309 of FIG. 3K . Seen in FIG. 3L is a cross-section AA, which is shown in FIG. 3M .
[0171] FIG. 3M depicts a cross-sectional view of cross-section AA of FIG. 3L .
[0172] FIG. 3N depicts a side view of the exemplary top plunger 303 of FIG. 3I , which comprises rotational collar 308 , top vertical frame support 309 , and threaded boss 310 . Seen in FIG. 3N is a cross-section EE, which is shown in FIG. 3O .
[0173] FIG. 3O depicts a cross-sectional view of cross-section EE of FIG. 3N .
[0174] FIG. 4A depicts a cross-sectional view of cross-section AA of FIG. 3B . Shown is circular region B which is enlarged in FIG. 4B .
[0175] FIG. 4B depicts an enlarged view of the circled area B of FIG. 4A . As shown, the two top plungers 303 are able to rotate around bottom frame tubing 129 . A portion of a cross frame 302 can be seen behind the two top plungers 303 .
[0176] FIG. 4C depicts a cross-sectional view of cross-section CC of FIG. 3A . Seen in FIG. 4C is a circled area D, which is enlarged in FIG. 4D .
[0177] FIG. 4D depicts an enlarged view of the circled area D of FIG. 4C , which shows the bottom frame tubing 129 within a rear male limiting collar 306 .
[0178] FIGS. 5A , 5 B, and 5 C depict different side views and an isometric view of an exemplary side support 501 in accordance with an embodiment of the invention an embodiment of the invention. The side support 501 comprises a frame side support 501 , a front female limiting collar, 502 , and a rotational collar 503 . Shown in FIG. 5A is a circled area A that is enlarged in FIG. 6B . Although the side support 501 is shown having a fixed length it could instead be configured using multiple tubing having different sizes to enable telescopic behavior.
[0179] FIG. 6A depicts an exemplary frame side support 501 in accordance with an embodiment of the invention. The side support 501 has mounting holes down its length that enable quick release pins to attach objects to the side support such as brackets and the like.
[0180] FIG. 6B depicts an enlarged view of the circled area A of FIG. 5A .
[0181] FIG. 6C depicts an exemplary front female limiting collar 502 in accordance with an embodiment of the invention. The notch portion of the collar 502 allows a range of movement when used with a cross frame 302 , where the range of movement corresponds to the rotation of the side support relative to the tubing when the width of the cart is extended or collapsed.
[0182] FIG. 6D depicts an exemplary rotational collar 503 in accordance with an embodiment of the invention. The rotational collar 503 of FIG. 6D is very similar to the rotational collar 308 of FIG. 3J except it does not include a hole for a threaded boss.
[0183] FIGS. 7A and 7B depict side and isometric views of an exemplary an extendable top or bottom member 104 in accordance with an embodiment of the invention, which comprises a rear frame tubing 701 , a rear tube stopper 702 , and a flat head machine screw 703 . Seen in FIG. 7A is a cross-section AA, which is shown in FIG. 8A .
[0184] FIG. 8A depicts a cross-sectional view of cross-section AA of FIG. 7A .
[0185] FIG. 8B depicts an exemplary rear frame tubing 701 in accordance with an embodiment of the invention.
[0186] FIG. 8C depicts an exemplary rear tube stopper 702 in accordance with an embodiment of the invention.
[0187] FIG. 9 depicts an exemplary rear cross frame 105 , in accordance with an embodiment of the invention, which is similar to the cross frame 302 except its male limiting collars have smaller inside diameters to accommodate the smaller outer diameter of the extendable member 104 .
[0188] FIGS. 10A , 10 B, and 10 C depict different side views and an isometric view of an exemplary rear side support 106 in accordance with an embodiment of the invention, which comprises a frame side support 1001 , rear female limiting collar 1002 , and rear side support collar 1003 . FIG. 10A includes a circled area A that is enlarged in FIG. 11B .
[0189] FIG. 11A depicts an exemplary frame side support 1001 in accordance with an embodiment of the invention.
[0190] FIG. 11B depicts an enlarged view of the circled area A of FIG. 10A .
[0191] FIG. 11C depicts an exemplary rear female limiting collar 1002 in accordance with an embodiment of the invention. The rear female limiting collar 1002 of FIG. 11C is similar to the rear female limiting collar 502 of FIG. 6C except it has a smaller inside diameter or cross-section intended to accommodate the smaller outer diameter or cross-section of extendable member 104 . The notch portion of the collar 1002 allows a range of movement when used with a rear cross frame 105 , where the range of movement corresponds to the rotation of the rear side support relative to the tubing when the width of the cart is extended or collapsed.
[0192] FIG. 11D depicts an exemplary rear side support collar 1003 in accordance with an embodiment of the invention. The rear side support collar 1003 of FIG. 11D is similar to the rear side support collar 503 of FIG. 6D except it has a smaller inside diameter intended to accommodate the smaller outer diameter of extendable member 104 .
[0193] FIG. 12 depicts an isometric view of an exemplary middle wheel mount 108 in accordance with an embodiment of the invention, which comprises a wheel mounting plate and wheel mount tubing.
[0194] FIG. 13A depicts an exemplary wheel mounting plate 1301 in accordance with an embodiment of the invention.
[0195] FIG. 13B depicts a side view of the exemplary middle wheel mount 108 of FIG. 12 . Shown in FIG. 31B is a cross-section AA, which is depicted in FIG. 13C .
[0196] FIG. 13C depicts a cross-sectional view of cross-section AA of FIG. 13B .
[0197] FIG. 14 depicts an exemplary front support 109 in accordance with an embodiment of the invention.
[0198] FIG. 15A depicts an end view of the exemplary front support 109 of FIG. 14 , where a male cross support 1502 is attached to a rotational collar 503 having an inside diameter sized to rotate about the bottom frame tubing. The outside diameter of the male cross support 1502 is sized to fit inside a female cross support 1702 .
[0199] FIG. 15B depicts a side view of the exemplary front support of FIG. 14 .
[0200] FIG. 15C depicts an exemplary male cross support 1502 in accordance with an embodiment of the invention.
[0201] FIG. 16 depicts an exemplary rear cross support 110 in accordance with an embodiment of the invention.
[0202] FIG. 17A depicts an end view of the exemplary rear cross support 110 of FIG. 16 , where a female cross support 1702 is attached to a rotational collar 1003 having an inside diameter sized to rotate about the extendable member 104 . The inside diameter of the female cross support 1702 is sized to accept a male cross support 1502 .
[0203] FIG. 17B depicts a side view of the exemplary rear cross support of FIG. 16 . Seen in FIG. 17B is a cross-section AA, which is depicted in FIG. 17C . The inside diameter of the rear side support collar 1003 is sized to rotate about the extendable member 104 .
[0204] FIG. 17C depicts a cross-sectional view of cross-section AA of FIG. 17B , which shows a folding sleeve insert 1703 , a pan head machine screw 1704 , and a flat washer 1705 .
[0205] FIG. 17D depicts an isometric view of an exemplary folding sleeve insert 1703 in accordance with an embodiment of the invention.
[0206] FIG. 17E depicts a side view of the exemplary folding sleeve insert 1703 of FIG. 17D .
[0207] FIG. 17F depicts an end view of the exemplary folding sleeve insert 1703 of FIG. 17D .
[0208] FIG. 18 depicts another exemplary rear cross support 111 in accordance with an embodiment of the invention.
[0209] FIG. 19A depicts an end view of the exemplary rear cross support 111 of FIG. 18 , where a male cross support 1502 is attached to a rotational collar 1003 having an inside diameter sized to rotate about the extendable member 104 . The diameter of the male cross support 1502 is sized to allow it to fit within female cross support 1702 .
[0210] FIG. 19B depicts a side view of the exemplary rear cross support 111 of FIG. 18 .
[0211] FIG. 20 depicts another exemplary second front support 112 in accordance with an embodiment of the invention.
[0212] FIG. 21A depicts an end view of the exemplary second front support 112 of FIG. 20 , where a female cross support 1702 is attached to a rotational collar 503 having an inside diameter sized to rotate about the bottom frame tubing 129 . The diameter of the female cross support 1702 is sized to accept a male cross support 1502 .
[0213] FIG. 21B depicts a side view of the exemplary second front support 112 of FIG. 20 . Seen in FIG. 21B is a cross-section AA, which is depicted in FIG. 21C .
[0214] FIG. 21C depicts a cross-sectional view of cross-section AA of FIG. 21B , which shows a folding sleeve insert 1703 , a pan head machine screw 1704 , and a flat washer 1705 .
[0215] FIG. 22 depicts an isometric view of an exemplary outer wheel mount in accordance with an embodiment of the invention, which comprises a wheel mounting plate 1301 and wheel mount tubing 1302 .
[0216] FIG. 23A depicts a side view of the exemplary outer wheel mount of FIG. 22 . Seen in FIG. 23A is a cross-section AA, which is depicted in FIG. 23B .
[0217] FIG. 23B depicts a cross-sectional view of cross-section AA of FIG. 23A .
[0218] FIG. 24 depicts an isometric view of an exemplary shelf post 118 in accordance with an embodiment of the invention.
[0219] FIG. 25A depicts a side view of the exemplary shelf post 118 of FIG. 24 . Seen in FIG. 25A is a cross-section AA, which is depicted in FIG. 25C .
[0220] FIG. 25B depicts an end view of the exemplary shelf post 118 of FIG. 24 . Seen in FIG. 25B is a cross-section AA, which is depicted in FIG. 25C .
[0221] FIG. 25C depicts a cross-sectional view of cross-sections AA of FIGS. 25A and 25B .
[0222] FIG. 26 depicts an isometric view of an exemplary bottom plunger 126 in accordance with an embodiment of the invention.
[0223] FIG. 27A depicts a side view of the exemplary bottom plunger 126 of FIG. 26 , which comprises a rotational collar 308 , a threaded boss 310 , and a bottom vertical frame support 2702 . Seen in FIG. 27A is a cross-section AA, which is depicted in FIG. 27B .
[0224] FIG. 27B depicts a cross-sectional view of cross-section AA of FIG. 27A .
[0225] FIG. 27C depicts an isometric view of an exemplary bottom vertical frame support 2702 in accordance with an embodiment of the invention. The bottom vertical frame support 2702 has mounting holes down its length for use with brackets and the like.
[0226] FIG. 27D depicts an end view of the exemplary bottom vertical frame support 2702 of FIG. 27C . Seen in FIG. 27D is a cross-section AA, which is depicted in FIG. 27E .
[0227] FIG. 27E depicts a cross-sectional view of cross-section AA of FIG. 27D .
[0228] FIG. 28A depicts a top view of an exemplary strap 128 in accordance with an embodiment of the invention.
[0229] FIG. 28B depicts a side view of the exemplary strap 128 of FIG. 28A .
[0230] FIG. 29A depicts an isometric view of an exemplary bottom frame tubing 129 in accordance with an embodiment of the invention;
[0231] FIG. 29B depicts a side view of the exemplary bottom frame tubing 129 of FIG. 29A . Seen in FIG. 29B are cross-sections AA and BB, which are depicted in FIG. 29C and FIG. 29D , respectively.
[0232] FIG. 29C depicts a cross-sectional view of cross-section AA of FIG. 29B .
[0233] FIG. 29D depicts a cross-sectional view of cross-section BB of FIG. 29B .
[0234] FIG. 30A depicts an isometric view of an exemplary collapsing sleeve insert 130 in accordance with an embodiment of the invention.
[0235] FIGS. 30B and 30C depict end and side views of the exemplary collapsing sleeve insert 130 of FIG. 30A , respectively.
[0236] FIG. 31 depicts an isometric view of an exemplary mating collar 132 in accordance with an embodiment of the invention. Mating collar 132 is attached, or mated with collapsing sleeve insert 130 as depicted in FIG. 2C .
[0237] The A-frame cart 100 of the invention can be configured using interchangeable brackets to accommodate different storage and transport requirements of objects having different shapes and sizes. Described below are two examples of how such interchangeable brackets can be used for transporting aircraft stabilator, drive shaft, tail rotor, etc. Specifically, descriptions of an exemplary cart assembly configured for transporting stabilator and of an exemplary cart assembly configured for transporting drive shaft and tail rotor are provided. One skilled in the art will recognize that in accordance with an embodiment of the invention the A-frame cart 100 can be configured in numerous other ways as appropriate to accommodate many different objects of different sizes and shapes.
[0238] FIG. 32A-32C depict isometric, end, and side views of an exemplary stabilator configured cart assembly 3200 in accordance with a second embodiment of an embodiment of the invention. Referring to FIG. 32A , the stabilator configured cart assembly 3200 comprises an A-frame cart 100 , eight exterior bracket assemblies 3202 , sixteen upper strap assemblies 3203 , eight inner bracket assemblies 3204 , a base shelf assembly 3205 , and a secondary base shelf assembly 3206 . Seen in FIG. 32A is circled area A, which is depicted in FIG. 33A . Seen in FIG. 32B is circled area B, which is depicted in FIG. 33B . Side views of stabilator components 3212 and 3214 are provided in FIG. 32C .
[0239] FIGS. 33A and 33B depict enlarged views of the circled areas A and B of FIGS. 32A and 32B , respectively. Referring to FIG. 33A , pan head machine screws 3208 and flat washers 3210 are shown being used to attach the base shelf assembly 3205 to the second front support 112 . Referring to FIG. 33B , exterior and interior bracket assemblies 3202 , 3204 are attached to a side support 102 using quick release pins 116 that are attached to lanyard/wire rope/loop tab assemblies 119 using pan head machine screws 120 and flat washers 121 in a manner like that shown in FIG. 2A .
[0240] FIGS. 34A and 34B depict isometric views of an exemplary exterior bracket assembly 3202 in accordance with an embodiment of the invention. Referring to FIGS. 34A and 34B , exterior bracket assembly 3202 comprises an exterior bracket 3401 , a rubber insert 3402 , a base strap assembly 3403 , a nylon-insert locknut 3404 , and a flat head machine screw 703 . The assembly is attached to a side support 102 using a quick release pin 116 that is attached to lanyard/wire rope/loop tab assembly 119 using a pan head machine screw 120 and a flat washer 121 .
[0241] FIGS. 35A-C depict isometric, end, and side views of an exemplary exterior bracket 3401 in accordance with an embodiment of the invention. The exterior bracket 3401 comprises an exterior stabilator mounting bracket 3501 , two mounting gussets 3502 , and two exterior mounting ribs.
[0242] FIG. 36A depicts an isometric view of an exemplary exterior stabilator mounting bracket 3501 in accordance with an embodiment of the invention.
[0243] FIG. 36B depicts an isometric view of an exemplary exterior mounting gusset 3502 in accordance with an embodiment of the invention.
[0244] FIG. 36C depicts an isometric view of an exemplary exterior mounting rib 3503 in accordance with an embodiment of the invention.
[0245] FIG. 37 depicts an isometric view of an exemplary rubber insert 3402 in accordance with an embodiment of the invention.
[0246] FIGS. 38A and 38B depict top and side views of an exemplary base strap assembly 3403 in accordance with an embodiment of the invention. Referring to FIG. 38A , the base strap assembly 3403 comprises a straight shape end mounting plate 3801 , a nylon strap 3802 , and a female buckle 3803 .
[0247] FIGS. 39A and 39B depict isometric and side views of an exemplary upper strap assembly 3203 in accordance with an embodiment of the invention. Referring to FIGS. 39A and 39B , the upper strap assembly 3203 comprises an upper strap mount 3901 , an upper stabilator strap assembly 3902 , a flat head machine screw 703 , and a nylon-insert locknut 3404 . The upper strap assembly 3203 attaches to a side support 102 using a quick-pin 116 , a lanyard/wire rope/loop-tab assembly 119 , a pan head machine screw 120 , and a flat washer 121 .
[0248] FIG. 40A depicts an isometric view of an exemplary upper strap mount 3901 in accordance with an embodiment of the invention.
[0249] FIGS. 40B and 40C depict side and top views of an exemplary upper stabilator strap assembly 3902 in accordance with an embodiment of the invention. The upper stabilator strap assembly 3902 comprises a nylon strap 4001 , a male buckle 4002 , and a strap end mounting plate 4003 .
[0250] FIGS. 41A and 41B depict isometric views of an exemplary interior bracket assembly 3204 in accordance with an embodiment of the invention. The interior bracket assembly 3204 comprises an interior bracket 4101 , an interior rubber insert 4102 , a flat head machine screw 703 , a nylon-insert locknut 3404 , and a base strap assembly 3403 .
[0251] FIGS. 42A-C depict isometric, end, and side views of an exemplary interior bracket 4101 in accordance with an embodiment of the invention. The interior bracket 4101 comprises an interior bracket 4201 , two mounting gussets 3502 , and two interior mounting ribs 4203 .
[0252] FIG. 43A depicts an isometric view of an exemplary interior stabilator mounting bracket 4201 in accordance with an embodiment of the invention.
[0253] FIG. 43B depicts an isometric view of an exemplary interior mounting rib 4203 in accordance with an embodiment of the invention.
[0254] FIG. 44 depicts an isometric view of an exemplary base shelving assembly 3205 in accordance with an embodiment of the invention. Referring to FIG. 44 , the base shelving assembly 3205 comprises a base shelf 4401 and a shelf rubber 4403 (e.g., Buna-N-Foam). Also shown in FIG. 44 are two quick release pins 116 , two lanyard/wire rope/loop-tab assemblies 119 , two pan head machine screws 120 , and two flat washers 121 that are used to attach the base shelving assembly 3205 to the bottom frame tubing 129 .
[0255] FIG. 45 depicts an isometric view of an exemplary secondary base shelving assembly 3206 in accordance with an embodiment of the invention. Referring to FIG. 45 , the secondary base shelving assembly 3206 is just like the base shelving assembly 3205 of FIG. 44 except it has a secondary base shelf 4501 in place of the base shelf 4401 used in the base shelving assembly 3205 .
[0256] FIG. 46A-46C depict isometric, end, and side views of an exemplary drive shaft and tail rotor configured cart assembly 4600 in accordance with a third embodiment of an embodiment of the invention. The drive shaft and tail rotor configured cart assembly 4600 comprises an A-frame cart 100 , two top drive shaft mount assemblies 4602 , twenty exterior shaft bracket assemblies 4603 , and eight interior tail rotor assemblies. It should be noted that the bottom plungers 126 and the top plungers 303 of the moveable side support arm are configured to provide support independent of each other, where the bottom plungers 126 have been rotated 180° such that angle outwards from the drive shaft and tail rotor configured cart assembly 4600 . Shown stored in the cart assembly 4600 are small drive shaft assemblies 4610 , shafts 4612 , large drive shaft assemblies 4614 , rotary wing blades 4616 , and fan shaft assemblies 4618 . Seen in FIG. 46A is a circled area A, which is depicted in FIG. 47A . Seen in FIG. 46B is a circled area B, which is depicted in FIG. 47B .
[0257] FIGS. 47A and 47B depict enlarged views of the circled areas A and B of FIGS. 46A and 46B , respectively. Referring to FIG. 47A , a top drive shaft mount assembly 4602 is shown attached to top structure 101 . Referring to FIG. 47B , exterior shaft bracket assemblies 4603 and an interior tail rotor assembly 4604 are attached to a side support 102 using quick release pins 116 that are attached to lanyard/wire rope/loop tab assemblies 119 using pan head machine screws 120 and flat washers 121 in a manner like that shown in FIG. 2A .
[0258] FIG. 48 depicts an isometric view of an exemplary top drive shaft mount assembly 4602 in accordance with an embodiment of the invention. Referring to FIG. 48 , top drive shaft mount assembly 4602 comprises a top drive shaft mount 4801 , two rubber inserts 3402 , an upper drive shaft strap assembly 4803 , a base strap assembly 3403 , two flat head machine screws 4810 , and two nylon-insert locknuts 3404 . The top drive shaft mount assembly 4602 attaches to the top structure 101 at four locations using a quick-pin 116 , a lanyard/wire rope/loop-tab assembly 119 , a pan head machine screw 120 , and a flat washer 121 at each location.
[0259] FIG. 49 depicts an isometric view of an exemplary top drive shaft mount 4801 in accordance with an embodiment of the invention. Referring to FIG. 49 , top drive shaft mount 4801 comprises two top shaft mounting plates 5001 , two support plates 5002 , and four top support braces 5003 .
[0260] FIG. 50A depicts an isometric view of an exemplary top drive mounting plate 5001 in accordance with an embodiment of the invention.
[0261] FIG. 50B depicts an isometric view of an exemplary support plate 5002 in accordance with an embodiment of the invention.
[0262] FIG. 50C depicts an isometric view of an exemplary top support brace 5003 in accordance with an embodiment of the invention.
[0263] FIGS. 51A and 51B depict side and top views of an exemplary upper drive shaft strap assembly 4803 in accordance with an embodiment of the invention. The upper drive shaft strap assembly 4803 comprises a nylon strap 4001 , a male buckle 4002 , and a strap end mounting plate 4003 and is a shorter version of the upper stabilator strap assembly 3902 described in relation to FIGS. 40A-40C .
[0264] FIGS. 52A and 52B depict isometric views of an exemplary exterior shaft bracket assembly 4603 in accordance with an embodiment of the invention. The exterior shaft bracket assembly 4603 comprises an exterior shaft bracket 5201 , a rubber insert 3402 , a strap tab 5203 , a strap retainer 5204 , a replacement strap 5205 , and two flat head metal screws 4810 . The exterior shaft bracket assembly 4603 is attached to a side support 102 using a quick-pin 116 , a lanyard/wire rope/loop-tab assembly 119 , a pan head machine screw 120 , and a flat washer 121 .
[0265] FIG. 53A depicts an isometric view of an exemplary exterior shaft bracket 5201 in accordance with an embodiment of the invention.
[0266] FIG. 53B depicts an isometric view of an exemplary strap tab 5203 in accordance with an embodiment of the invention.
[0267] FIG. 53C depicts an isometric view of an exemplary strap retainer 5204 in accordance with an embodiment of the invention.
[0268] FIGS. 54A and 54B depict isometric views of an exemplary interior tail rotor assembly 4604 in accordance with an embodiment of the invention. The interior tail rotor assembly 4604 comprises an interior tail rotor bracket assembly 5401 , a rubber insert 3402 , two flat head machine screws 4810 , two nylon-insert locknuts 3404 , a base strap assembly 3403 , and a tail rotor strap assembly 5506 . The interior tail rotor assembly 4603 is attached to a side support 102 using a quick-pin 116 , a lanyard/wire rope/loop-tab assembly 119 , a pan head machine screw 120 , and a flat washer 121 .
[0269] FIGS. 55A and 55B depict an isometric and an end view of an exemplary interior tail rotor bracket assembly 5401 in accordance with an embodiment of the invention. The interior tail rotor bracket assembly 5401 comprises an interior tail rotor bracket 5501 and two mounting gussets 3502 .
[0270] FIG. 56 depicts an isometric view of an exemplary interior tail rotor bracket 5501 in accordance with an embodiment of the invention.
[0271] FIGS. 57A and 57B depict side and top views of an exemplary tail rotor strap assembly 5506 in accordance with an embodiment of the invention. The tail rotor strap assembly 5506 comprises a nylon strap 4001 , a male buckle 4002 , and a strap end mounting plate 4003 and is a shorter version of the upper stabilator strap assembly 3902 described in relation to FIGS. 40A-40C and a slightly longer version of the drive shaft strap assembly 4803 of FIGS. 51A and 51B .
[0272] Under one arrangement, an A-frame cart 100 includes one or more attachment mechanisms (e.g., a trailer hitch and ball) for attaching one cart 100 to another cart 100 and/or allowing a cart to be attached to a vehicle (e.g., a fork lift). An attachment mechanism could be configured to pivot where it is attached to the cart 100 . An A-frame cart might be configured with a winch mechanism.
[0273] Under another arrangement enclosed compartments can be attached to the cart 100 and used for storage of components.
[0274] Under still another arrangement the top portion of the cart (i.e., the top frame) could be configured to be capable of spreading apart so as to allow a component to be lowered into the interior of the cart 100 . Similarly, the bottom portion of the cart could be configured to be able to capable of spreading apart so as to allow the cart to roll across and straddle a component prior to the bottom portion being secured. The cart could comprise pulleys and associated cabling.
[0275] Under a further arrangement, fixed panels can be attached to the cart 100 in various configurations to provide shelving, to constrain movement of stored components, to provide additional attachment locations (e.g., peg board), or to serve some other desired purpose. Similarly, flexible materials such as tarps, netting, and the like can be attached to the cart in various configurations to constrain movement of stored components, to provide additional attachment locations, or to serve other desired purposes. Generally, many different forms of attachment such as bungee cords, Velcro, ropes, magnets, adhesives, hooks, snaps, knobs, nuts and bolts, and the like can be used to secure objects to the cart 100 . Moreover, many different well known methods for reducing friction between parts of the cart 100 , reducing noise, increasing or decreasing visibility, and the like can be employed, as appropriate.
[0276] Under yet another arrangement, the A-frame cart 100 is equipped with a communications apparatus (e.g., a transmitter and/or receiver) for communicating its position or the status of one or more components stored on the cart 100 .
[0277] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims, an embodiment of the invention an embodiment of the invention | A stable extendable apparatus is provided which includes top, bottom, front and rear structures coupled together. The top and bottom structures each include at least one extendable member which defines a minimum length in a longitudinal retracted position and a maximum length in a longitudinal extended position. The front and rear structures each includes a first side support, a second side support, and an extendable cross-support to couple the first and second side supports together. Extension or retraction of the extendable cross-support changes an angle of orientation of the first side support relative to the second side support. The first rear side support, the second rear side support, and the extendable rear cross-support correspond to positions of the respective front supports. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation Application of, and claims the benefit of priority under 35 U.S.C. § 120 from, U.S. application Ser. No. 11/334,427, filed Jan. 19, 2006, which is a Continuation of U.S. Pat. No. 7,027,762, issued Apr. 11, 2006, which is a Continuation of U.S. Pat. No. 6,898,408, issued May 24, 2005, and claims the benefit of priority under 35 U.S.C. § 119 from Japanese Patents Applications No. 2001-374541, filed Dec. 7, 2001 and 2002-322502, filed Nov. 6, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a copier, printer, facsimile apparatus or similar image forming apparatus operable in a duplex print mode for printing images on both sides of a sheet or recording medium.
2. Description of the Related Art
It is a common practice with an image forming apparatus operable in a duplex print mode to transfer a toner image from an image carrier to one surface of a sheet, fix the toner image, turn the sheet via, e.g., a turn path, and again feed the sheet to form another toner image on the other side of the sheet. The problem with this type of apparatus is that the sheet cannot be reliably conveyed due to the switching of the sheet conveying direction and the curl of the sheet ascribable to the fixation of the toner image on one side of the sheet.
In light of the above, Japanese Patent Laid-Open Publication No. 1-209470 discloses an image forming apparatus including a first and a second image carrier for transferring toner images to both sides of a sheet and then fixing them at the same time. More specifically, in the apparatus taught in this document, a first image formed on a photoconductive element is transferred to an image transfer belt by first image transferring means. Subsequently, a second toner image formed on the photoconductive element is transferred to one side of a sheet. Thereafter, the first image is transferred from the belt to the other side of the sheet by second image transferring means. The sheet carrying the toner images on both sides thereof is conveyed to a fixing unit.
However, the procedure taught in the above document is not practicable without causing the image transfer belt to make two turns. More specifically, the second image begins to be formed only after the image transfer belt has made one full turn, resulting in lower productivity in the duplex print mode. This is particularly true when full-color images are formed on both sides of a sheet.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication No. 8-160703.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an image forming apparatus capable of executing a full-color duplex print mode without lowering productivity.
An image forming apparatus capable of forming images on both sides of a recording medium of the present invention includes a first image carrier on which a toner image to be formed, and a second image carrier to which the toner image is transferred from the first image carrier. The toner image transferred from the image carrier to the second image carrier is transferred to one side of the recording medium while a toner image is transferred from the first image carrier to the other side of the recording medium. After the toner image has been transferred from the first image carrier to the second image carrier, the running condition of the second image carrier is varied.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which:
FIG. 1 is a section showing an image forming apparatus embodying the present invention;
FIG. 2 is a section showing another specific configuration of an image forming section included in the illustrative embodiment;
FIG. 3 is a section showing still another specific configuration of the image forming section;
FIG. 4 is a section showing a modification of the illustrative embodiment;
FIGS. 5A through 5F demonstrate a specific operation of the illustrative embodiment;
FIGS. 6A through 6F demonstrate another specific operation of the illustrative embodiment;
FIGS. 7A through 7F demonstrate still another specific operation of the illustrative embodiment;
FIGS. 8A and 8B are graphs comparing the illustrative embodiment and a conventional image forming apparatus as to printing time;
FIGS. 9A through 9F demonstrate a specific operation representative of an alternative embodiment of the present invention;
FIGS. 10A through 10F demonstrate another specific operation available with the alternative embodiment;
FIG. 11 is a perspective view showing a specific configuration of a mechanism for selectively moving an intermediate image transfer belt into or out of contact with a photoconductive drum;
FIG. 12 is a perspective view showing a specific configuration of a mechanism for obviating the offset of the belt;
FIGS. 13A through 13C are side elevations showing the operation of the mechanism of FIG. 12 ;
FIG. 14 is a view showing a specific configuration of an image forming apparatus including a first image carrier implemented as a belt;
FIG. 15 is a section showing one of image forming units included in the apparatus of FIG. 14 ;
FIGS. 16A and 16B are sections showing a specific configuration for selectively moving a second image carrier included in the apparatus of FIG. 14 into or out of contact with the first image carrier;
FIGS. 17A and 17B are fragmentary sections showing another specific configuration for moving the second image carrier;
FIGS. 18A through 18C show specific timing marks formed on the second image carrier and means for sensing the timing marks;
FIG. 19 is a timing chart representative of a specific operation of the apparatus shown in FIG. 14 ;
FIG. 20 demonstrates specific speed control over a stepping motor assigned to the second image carrier;
FIG. 21 is a section showing a unit, which includes the second image carrier of the apparatus shown in FIG. 14 , in an open position;
FIG. 22 is a section showing another specific configuration of the image forming apparatus including another specific configuration of a fixing device;
FIG. 23 is a fragmentary section showing a unit, which includes the second image carrier of the apparatus shown in FIG. 22 , in an open position;
FIG. 24 is a section showing another specific configuration of the image forming apparatus;
FIG. 25 is a perspective view showing a plurality of image forming apparatuses each having any one of the configurations of FIGS. 14 , 22 and 24 and interconnected by a network;
FIG. 26 is a view showing another specific configuration of the image forming apparatus in which a first image carrier is implemented as a plurality of image carriers;
FIG. 27 is a section showing a second image carrier included in the apparatus of FIG. 26 ; and
FIG. 28 is a fragmentary view showing a specific configuration of a mechanism for moving the second image carrier of FIG. 27 into and out of contact with the first image carrier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, an image forming apparatus embodying the present invention is shown and implemented as a printer by way of example. As shown, the printer, generally 100 , includes a photoconductive drum or first image carrier 1 positioned at substantially the center of the printer body. Arranged around the drum 1 are a drum cleaner 2 , a discharger 3 , a charger 4 , and a revolver type developing unit (revolver hereinafter) 5 R. An optical writing unit 7 is positioned above the drum 1 and scans the surface of the drum 1 with a laser beam L at a position between the charger 4 and the revolver 5 R.
A belt unit 20 is arranged below the drum 1 and includes an intermediate image transfer belt or second image carrier 10 . In the illustrative embodiment, the intermediate image transfer belt (simply belt hereinafter) 10 is angularly movable into or out of contact with the drum 1 in a direction indicated by a double-headed arrow K in FIG. 1 . When image formation is not under way, the belt 10 is spaced from the drum 1 so as not to curl or otherwise deform or adversely effect the drum 1 . The belt 10 should preferably be releasable from the drum 1 in the event of jam processing as well.
The belt 10 is passed over rollers 11 , 12 and 13 . A moving mechanism, which will be described later, causes the belt 10 to angularly move about the roller 11 into or out of contact with the drum 1 in the direction K. The belt 10 is heat-resistant, coated with PFA (perfluoroalcoxy), and provided with resistance of 10 5 Ω·cm to 10 12 Ω·cm that allows toner to be transferred to the belt 10 . In the illustrative embodiment, a mark, not shown, is provided on the belt 10 for controlling the system. In the event of power-up, the timing mark on the belt 10 is sensed to bring the belt 10 to a preselected reference or initial position.
Back rollers 14 and 15 , cooling means 16 , a fixing roller 18 and first image transferring means 21 are arranged inside of the loop of the belt 10 . The fixing roller 18 accommodates a heater or similar heat source and fixes a toner image carried on a sheet. The first image transferring means 21 faces the drum 1 with the intermediary of the belt 10 for transferring a toner image formed on the drum 1 to the belt 10 or a sheet. The belt 10 is driven by a stepping motor 53 (see FIG. 11 ) via the drive roller 11 . The stepping motor 53 is independent of a motor that drives the drum 1 and other rotary members. Second image transferring means 22 , a fixing device 22 and a belt cleaner 25 are positioned outside of the loop of the belt 10 . The fixing device 30 includes a fixing roller 19 also accommodating a heater or similar heat source and fixes a toner image carried on a sheet. A mechanism, not shown, causes the fixing device 30 to angularly movable about a fulcrum 30 a into or out of contact with the fixing roller 18 with the intermediary of the belt 10 (and sheet) in a direction indicated by a double-headed arrow G.
The belt cleaner 25 assigned to the belt 10 includes a cleaning roller 25 a , a blade 25 b and toner conveying means
25 c and removes toner left on the belt 10 after image transfer. The toner conveying means 25 c conveys the toner collected in the belt cleaner 25 to a container not shown. The belt cleaner 25 is angularly movable about a fulcrum 25 d in a direction indicated by a double-headed arrow H. A mechanism, not shown, causes the belt cleaner 25 to move into or out of contact with the belt 10 in the direction H.
The drum 1 , drum cleaner 2 , charger 4 and revolver 5 R may be constructed into a single process cartridge replaceable when its life ends.
A sheet cassette 26 is positioned in the lower portion of the printer body and can be pulled out to the front in the direction perpendicular to the sheet surface of FIG. 1 . Sheets or recording media P are stacked on the cassette 26 . A pickup roller 27 is positioned above the right end, as viewed in FIG. 1 , of the sheet cassette 26 . A manual sheet feed tray 35 is mounted on the right side, as viewed in FIG. 1 , of the printer body. The manual sheet feed tray 35 includes a bottom plate 37 loaded with sheets P and constantly biased toward a pickup roller 36 .
A registration roller pair 28 is located at the right-hand side, as viewed in FIG. 1 , of the drum 1 . A guide 29 guides the sheet P fed from either one of the sheet cassette 26 and manual sheet feeder 35 toward the registration roller pair 28 . An electric unit E 1 and a control unit E 2 are positioned above the sheet cassette 26 .
A path selector 42 is positioned at the left-hand side, as viewed in FIG. 1 , of the fixing device 30 . The path selector 42 is pivotable about a fulcrum 43 to steer the sheet P coming out of the belt unit 20 to either one of a stack portion 40 positioned on the top of the printer body and a print tray 44 mounted on the side of the printer body. More specifically, a solenoid or similar actuator, not shown, moves the path selector 42 to a position shown in FIG. 1 for steering the sheet P toward the stack portion 40 or moves it in a direction indicated by an arrow J for steering the sheet P toward the print tray 44 .
A roller pair 33 is positioned above the path selector 42 for conveying the sheet P while a roller pair 34 is positioned above the roller pair 33 for driving the sheet P to the stack portion 40 . Guides 31 a and 31 b cooperate to guide the sheet P from the roller pair 33 to the roller pair 34 . A roller pair 32 is positioned at the left-hand side, as viewed in FIG. 1 , of the path selector 42 for driving the sheet P out of the printer body to the print tray 44 .
The revolver 5 R includes four developing sections 5 a through 5 d and is rotatable counterclockwise, as viewed in FIG. 1 , to locate one of the developing sections 5 a through 5 d at a developing position. The developing sections 5 a through 5 d each store toner of a particular color so as to implement full-color development. For example, the developing sections 5 a through 5 d store yellow toner, magenta toner, cyan toner and black toner, respectively. In a monochromatic. print mode, the developing section 5 d is located at the developing position.
The operation of the illustrative embodiment will be described hereinafter. First, a duplex print mode for forming images on both sides of the sheet P will be described. As for a duplex print mode, a toner image formed first and a toner image formed next will be referred to as a first and a second toner image, respectively. Also, a first and a second side of the sheet to which the first and second toner images are transferred will be referred to as a first and a second side, respectively.
On the power-up of the printer 100 , the belt or second image carrier 10 is brought to its reference position on the basis of the mark mentioned earlier. The printer 100 receives image data from a host machine, e.g., a computer. The writing unit 7 emits the laser beam L toward a polygonal mirror 7 a , which is rotated by a motor, in accordance with the image data. The laser beam L is steered by the polygonal mirror 7 a and incident to the surface of the drum 1 , which has been uniformly charged by the charger 4 , via a mirror 7 b , an f- 6 lens 7 c and so forth. As a result, a latent image corresponding to the image data, is electrostatically formed on the drum 1 .
In a monochromatic print mode, the developing section 5 d develops the latent image with the black toner for thereby producing a black toner image on the drum 1 . On the other hand, in a full-color print mode, the writing unit 7 first scans the charged surface of the drum 1 with the laser beam L in accordance with yellow image data, thereby forming a latent image. At this instant, the belt 10 is spaced from the drum 1 . The developing section 5 a located at the developing position develops the above latent image with yellow toner to thereby produce a yellow toner image. Subsequently, a magenta toner image is formed on the drum 1 over the yellow toner image. Likewise, a cyan toner image and a black toner image are sequentially formed on the drum 1 in this order over the composite toner image existing on the drum, completing a full-color toner image. The drum 1 makes four rotations for forming the full-color toner image. It is to be noted that the order of colors mentioned above is only illustrative.
The first image transferring means 21 transfers the toner image, which is monochromatic or full-color, from the drum 1 to the surface of the belt 10 , which is running in synchronism with the rotation of the drum 1 . After the image transfer, the drum cleaner 2 removes the toner left on the drum 1 . Subsequently, the discharger 3 discharges the surface of the drum 1 for thereby preparing it for the next image forming cycle.
The belt 10 , carrying the toner image or first toner image thereon, turns counterclockwise as viewed in FIG. 1 . At this instant, the second image transferring means 22 , fixing device 30 and belt cleaner 25 are maintained inoperative so as not to disturb the toner image carried on the belt 10 . For this purpose, such process units 22 , 30 and 25 may be released from the belt 10 or electric inputs thereto may be shut off.
After the entire first toner image has been transferred from the drum 1 to the belt 10 , the belt 10 is released from the drum 10 and then turned in the reverse direction, i.e., clockwise in FIG. 1 to the reference position. The distance of movement of the belt 1 is controlled on the basis of the number of steps of the stepping motor or drive means. In the illustrative embodiment, the reverse movement of the belt 10 is effected at a speed two times as high as the speed of the forward movement or usual speed. On reaching the reference position, the belt 10 is again brought into contact with the belt 10 and then moved counterclockwise, i.e., in the forward direction.
A toner image to be transferred to the second side of one sheet P, i.e., a second toner image is formed on the drum 1 in the same manner as the first toner image. At this instant, the top sheet P on the sheet cassette 26 or the manual sheet feed tray 35 is paid out by the pickup roller 27 or 36 , respectively, and conveyed to the nip between the registration rollers 28 . The registration roller pair 28 conveys the sheet P to the nip between the drum 1 and the belt 10 at a timing that matches the position of the toner image and that of the sheet P. The first image transferring means 21 transfers the second toner image from the drum 1 to the second side of the sheet P.
While the toner or second toner image is being transferred from the drum 1 to the second side of the sheet P, the other side or first side of the sheet P moves together with the toner existing on the belt 10 , i.e., with the first side contacting the first image. When the sheet P reaches the second image transferring means 22 , the transferring means 22 transfers the toner from the belt 10 to the sheet P by being applied with a voltage.
The belt 10 in movement conveys the sheet P carrying the toner images on both sides thereof to a fixing position where the fixing device 30 is located. At this instant, the fixing device 30 is angularly moved to press the fixing roller 19 against the fixing roller 18 via the belt 10 , so that the fixing rollers 18 and 19 cooperate to fix the. toner images on both sides of the sheet P. In this manner, the toner images are fixed on the sheet P with the sheet P contacting the belt 10 , so that the toner images are prevented from being disturbed. The sheet P coming out of the fixing device 30 is separated from the belt 10 at the position where the roller 11 is located. Subsequently, the path selector 42 steers the sheet P toward the stack portion 40 or the print tray 44 .
As shown in FIG. 1 , when the path selector 42 steers the sheet P toward the stack portion 40 , the sheet P is laid on the stack portion 40 with its surface to which the toner image is directly transferred from the drum 1 facing downward. Therefore, to stack consecutive prints on the stack portion 40 in order of page, it suffices to form a toner image corresponding to the second page first, transfer it to the belt 10 , form a toner image corresponding to the second page, and then directly transfer the toner image of the second page to the sheet P. In this respect, the first and second images correspond to the second and first pages, respectively. This is also true with the third page and successive pages. The crux is that when an image is present on an even page, it is formed first and transferred to the belt 10 , and then the image of an odd page preceding the even page is formed and directly transferred from the drum 1 to the sheet P.
On the other hand, when the path selector 42 steers the sheet P toward the print tray 44 , the sheet P is laid on the print tray 44 with its surface to which the toner image is directly transferred from the drum 1 facing upward. Therefore, when consecutive prints should be stacked on the print tray 44 in order of page, the first and second images correspond to the first and second pages, respectively. This is also true with the third page and successive pages. The crux is that when an image is present on an odd page, it is formed first and transferred to the belt 10 , and then the image of an even page following the odd page is formed and directly transferred from the drum 1 to the sheet P.
Usually, a reversed image or mirror image is formed on the drum 1 and then directly transferred from the drum 1 to the sheet P as a non-reversed image. However, as for image transfer from the belt 10 to the sheet P, a mirror image formed on the drum 1 would also be a mirror image on the sheet P. In light of this, the writing unit 7 scans the drum 7 such that an image to be transferred from the belt 10 to the sheet P is a non-reversed image on the drum 1 while an image to be directly transferred from the drum 1 to the sheet P is a mirror image on the drum 1 . Such an image forming sequence for page arrangement can be implemented by a conventional technology using a memory for storing image data. Also, exposure that selectively forms a reversed image or a non-reversed image can be implemented by a conventional image processing technology.
After the image transfer from the belt 10 to the sheet P, the belt cleaner 10 is angularly moved to bring the cleaning roller 25 a into contact with the belt 10 and cause the roller 25 a to remove toner left on the belt 10 . Subsequently, the blade 25 b wipes off the toner deposited on the cleaning roller 25 a . The toner collected by the blade 25 b is conveyed to the previously mentioned container by the toner conveying means 25 c.
The belt 10 moved away from the cleaning position is cooled off by the cooling means 16 that may use any conventional heat radiation scheme. For example, as for a scheme producing an air stream, it is preferable to cause air to flow after the image transfer from the belt 10 to the sheet P, thereby preventing the toner image carried on the belt 10 from being disturbed. Use may also be made of a heat pipe directly contacting the inner surface of the belt 10 . In any case, a fan F 1 discharges heat radiated from the belt 10 to the outside of the printer body.
A simplex print mode available with the illustrative embodiment for forming an image on one side of the sheet P will be described hereinafter. First, when the sheet or print P carrying an image on one side thereof, i.e., a simplex print should be driven out to the stack portion 40 , the image transfer from the drum 1 to the belt 10 is not necessary, i.e., a monochromatic or a full-color toner image is directly transferred from the drum 1 to the sheet P. In this case, a reversed image or mirror image is formed on the drum 1 and then transferred to the sheet P as a non-reversed image.
More specifically, as shown in FIG. 1 , the sheet P is conveyed to the nip between the drum 1 and the belt 10 in synchronism with the rotation of the drum 1 . The first image transferring means 21 transfers a toner image formed on the drum 1 to one side or upper surface of the sheet P facing the drum 1 . At this instant, the second image transferring means 22 does not operate. The sheet P with the toner image is conveyed by the belt 10 to the fixing device 30 , separated from the belt 10 , and then driven out to the stack portion 40 face down via the guides 31 a and 31 b and roller pair 32 , as indicated by an arrow A 1 . Consequently, even when several pages of documents are dealt with, the first page being first, the resulting prints are stacked on the stack portion 40 in order of page. Next, when the sheet or simplex print P should be driven out to the print tray 44 , the toner image formed on the drum 1 is transferred to the belt 10 by the first image transferring means 21 . After the transfer of the entire page, the belt 10 carrying the toner image is moved in the reverse direction, i.e., clockwise in FIG. 1 to the reference position. At this instant, the belt 10 is spaced from the drum 1 . On reaching the reference position, the belt 10 is again brought into contact with the drum 1 and then turned in the forward direction, i.e., counterclockwise in FIG. 1 . Subsequently, the second image transferring means 22 transfers the toner image from the belt 10 to the side or lower surface of the sheet P facing the belt 10 . Again, even when several pages of documents are dealt with, the first page being first, the resulting prints are stacked on the print tray 44 in order of page.
Even when an image is to be formed on a thick sheet, OHP (OverHead Projector) film or similar relatively hard sheet in the simplex print mode, the sheet can be substantially linearly conveyed if the manual sheet tray 35 and print tray 44 are designated. Therefore, simplex prints are achievable in order of page even with relatively thick, rigid sheets without degrading conveyance.
As stated above, after the transfer of a toner image from the drum 1 to the belt 10 , the illustrative embodiment moves the belt 10 in the reverse direction to the reference position and therefore does not have to wait until the belt 10 completes one full turn, thereby saving time. The reverse movement of the belt 10 is effective not only in the duplex print mode but also in the simplex print mode. Particularly, productivity is noticeably enhanced because the reverse movement of the belt 10 occurs at a speed two times as high as the speed of the forward movement. Stated another way, the illustrative embodiment improves productivity by varying the running condition of the belt or second image carrier 10 .
FIG. 2 shows another specific configuration of the fixing device. As shown, the fixing device, labeled 30 B, differs from the fixing device 30 , FIG. 1 , in that it does not contact the belt 10 . The fixing device 30 B fixes a toner image or toner images on the sheet with an infrared lamp, xenon lamp or similar lamp. The fixing device 30 , which does not contact the belt 10 , does not have to be angularly movable, but should only be fixed in place.
FIG. 3 shows another specific configuration of the fixing device. As shown, the fixing device, labeled 30 C is positioned outside of the loop of the belt 10 and includes the fixing rollers 18 and 19 each accommodating a respective heater. The fixing device 30 C is also fixed in place and does not have to be moved into or out of contact with the belt 10 .
FIG. 4 shows another specific configuration of the developing device. As shown, the developing device differs from the revolver 5 R in that four developing units 5 a through 5 d each storing toner of a particular color are arranged around the drum 1 . The developing device of FIG. 4 is similarly applicable to the specific configuration shown in FIG. 2 or 3 .
Reference will be made to FIGS. 5A through 5F for describing a specific image forming sequence that the illustrative embodiment effects in the duplex print mode, taking the configuration of FIG. 2 as an example. The belt 10 is shown as extending in the up-and-down direction for space reasons. In FIGS. 5A and 5E , while the drum 1 and belt 10 are shown as being spaced from each other, they are, in practice, held in contact with each other.
First, as shown in FIG. 5A , the charger 4 uniformly charges the surface of the drum 1 to negative polarity. The writing unit scans the charged surface of the drum 1 with the laser beam L to thereby form a latent image. The developing device 5 develops the latent image with negatively charged toner, which is represented by black dots in FIG. 5A , thereby producing a corresponding toner image. Subsequently, the first image transferring means 21 , which is applied with a positive voltage, transfers the toner image from the drum 1 to the belt 10 . This image transfer will be referred to as primary image transfer hereinafter.
As shown in FIG. 5B , after the primary image transfer, the belt 10 is brought to a stop. Subsequently, as shown in FIG. 5C , the belt 10 is released from the drum 1 in a direction K 1 and then moved in the reverse direction or clockwise to the reference position at the previously stated speed.
As shown in FIG. 5D , a toner image or second image of negative polarity is formed on the drum 1 while the belt 10 is again moved into contact with the drum 1 in a direction K 2 and then moved in the forward direction or counterclockwise. The sheet P is driven by the registration roller pair 28 at such a timing that the first and second images are accurately positioned on the sheet P.
As shown in FIG. 5E , the first image transferring means 21 , which is applied with a positive voltage, transfers the second image of negative polarity from the drum 1 to the sheet P. This image transfer will be referred to as secondary image transfer. At this instant, the first side of the sheet P is overlaid on the first image carried on the belt 10 .
Finally, as shown in FIG. 5F , the second image transferring means 22 , which is also applied with a positive voltage, transfers the first image of negative polarity from the belt 10 to the sheet P. This image transfer will be referred to as tertiary image transfer hereinafter. The belt 10 in movement conveys the sheet P carrying the first and second images thereon to the fixing position. The fixing means 18 and 30 B are heated, or turned on, to fix the first and second images on the sheet P. At this instant, the belt cleaner 25 is pressed against the belt 10 for removing toner left on the belt 10 . In the specific configuration shown in FIG. 3 , the sheet P separated from the belt 10 is conveyed to the fixing position.
Another specific image forming procedure available with the illustrative embodiment will be described hereinafter with reference to FIGS. 6A through 6F . Briefly, in the sequence to be described, a single image transferring means transfers the toner image carried on the belt 10 and the toner image formed on the drum 1 to both sides of the sheet P at the same time. More specifically, a charger or polarity switching device inverts the polarity of the toner image carried on the belt 10 , so that the toner image can be transferred to the sheet P at the same time as the toner image formed on the drum 1 by a single image transferring means. As for the rest of the construction, the procedure to be described is identical with the previous procedure.
The polarity of the toner image carried on the belt or second image carrier 10 may be inverted during either one of the forward movement and reverse movement of the belt 10 . First, assume that the polarity is inverted while the belt 10 is in reverse movement. The specific procedure uses the non-contact type of fixing device 30 B, FIG. 2 , by way of example.
As shown in FIGS. 6A through 6F , a polarity switching device 50 is positioned downstream of the image transferring means 21 in the direction of forward movement of the belt 10 , but upstream of the fixing device 30 B. The belt 10 is also angularly movable in the direction K, FIGS. 1 through 4 , into or out of contact with the drum 1 . The polarity switching device 50 is also movable in accordance with the movement of the belt 10 , so that the relative position of the former and latter does not change. The polarity switching device 50 is essentially identical with the second image transferring means 22 of the previous embodiment and may be implemented thereby so long as the relative position mentioned above does not change.
The procedure shown in FIGS. 6A through 6F differs from the procedure of FIGS. 5A through 5F in that it does not effect the tertiary image transfer. The belt 10 is shown as extending in the up-and-down direction for space reasons. In FIGS. 6A and 6E , while the drum 1 and belt 10 are shown as being spaced from each other, they are, in practice, held in contact with each other.
First, as shown in FIG. 6A , the charger 4 uniformly charges the surface of the drum 1 to negative polarity. The writing unit scans the charged surface of the drum 1 with the laser beam L to thereby form a latent image. The developing device 5 develops the latent image with negatively charged toner, which is represented by black dots in FIG. 6A , thereby producing a corresponding toner image. Subsequently, the image transferring means 21 , which is applied with a positive voltage, transfers the toner image from the drum 1 to the belt 10 (primary image transfer).
As shown in FIG. 6B , after the primary image transfer, the belt 10 is brought to a stop. Subsequently, as shown in FIG. 6C , the belt 10 is released from the belt 10 and then moved in the reverse direction or clockwise to the reference position at the previously stated speed. At this instant, the polarity switching device 50 is applied with a positive voltage, or turned on, to switch the polarity of the toner image on the belt 10 from negative to positive.
As shown in FIG. 6D , a toner image or second image of negative polarity is formed on the drum 1 while the belt 10 is again moved into contact with the drum 1 and then turned in the forward direction or counterclockwise. The sheet P is driven by the registration roller pair 28 at such a timing that the first and second images are accurately positioned on the sheet P.
As shown in FIG. 6E , the image transferring means 21 , which is applied with a positive voltage, transfers the toner image of negative polarity carried on the belt 10 and the second toner image of negative polarity formed on the drum 1 to the sheet P at the same time.
Finally, as shown in FIG. 6F , the belt 10 in movement conveys the sheet P carrying the first and second images thereon to the fixing position. The fixing means 18 and 30 B are heated, or turned on, to fix the first and second images on the sheet P. At this instant, the belt cleaner 25 is pressed against the belt 10 for removing toner left on the belt 10 . In the specific configuration shown in FIG. 3 , the sheet P separated from the belt 10 is conveyed to the fixing position.
Next, how the polarity is inverted while the belt 10 is in forward movement will be described with reference to FIGS. 7A through 7F . Again, the polarity switching device 50 is positioned downstream of the image transferring means 21 in the direction of forward movement of the belt 10 , but upstream of the fixing device 30 B. Also, the polarity switching device 50 may be fixed in place, if desired.
First, as shown in FIG. 7A , the charger 4 uniformly charges the surface of the drum 1 to negative polarity. The writing unit scans the charged surface of the drum 1 with the laser beam L to thereby form a latent image. The developing device 5 develops the latent image with negatively charged toner, which is represented by black dots in FIG. 7A , thereby producing a corresponding toner image. Subsequently, the image transferring means 21 , which is applied with a positive voltage, transfers the toner image from the drum 1 to the belt 10 (primary image transfer). While the belt 10 conveys the toner image forward, the polarity switching means 50 is applied with a positive voltage, or turned on, to switch the polarity of the toner image from negative to positive.
As shown in FIG. 7B , after the trailing edge of the toner image has moved away from the polarity switching device 50 , the belt 10 is brought to a stop. As a result, the entire toner image carried on the belt 10 is inverted in polarity.
Subsequently, as shown in FIG. 7C , the belt 10 is released from the belt 10 and then reversed in the clockwise direction to the reference position at the previously stated speed. Because the polarity of the toner image on the belt 10 has already been switched in polarity, it is not necessary to move the polarity switching device 50 together with the belt 10 .
As shown in FIG. 7D , a toner image or second image of negative polarity is formed on the drum 1 while the belt 10 is again moved into contact with the drum 1 and then turned in the forward direction or counterclockwise. The sheet P is driven by the registration roller pair 28 at such a timing that the first and second images are accurately positioned on the sheet P.
As shown in FIG. 7E , the image transferring means 21 , which is applied with a positive voltage, transfers the toner image of positive polarity carried on the belt 1 and the second toner image of negative polarity formed on the drum 1 to the sheet P at the same time.
Finally, as shown in FIG. 7F , the belt 10 in movement conveys the sheet P carrying the first and second images thereon to the fixing position. The fixing means 18 and 30 B are heated, or turned on, to fix the first and second images on the sheet P. At this instant, the belt cleaner 25 is pressed against the belt 10 for removing toner left on the belt 10 . In the specific configuration shown in FIG. 3 , the sheet P separated from the belt 10 is conveyed to the fixing position.
In the procedure shown in FIGS. 6A through 6F or 7 A through 7 F, in the simplex print mode, a toner image is. directly transferred from the drum 1 to the sheet P without the polarity switching device 50 being operated, i.e., in exactly the same manner as when two image transferring means are used.
In the procedure of FIGS. 6A through 6F or 7 A through 7 F, when a toner image is transferred from the drum 1 to the sheet P by way of the belt 10 in the simplex print mode, the polarity switching device 50 is operated to invert the polarity of the toner image. Such image transfer is executed in the same manner as in the duplex print mode except that the transfer of a second image to the drum 1 is not effected.
As stated above, even in the procedure in which a single image transferring means transfers a toner image carried on the second image carrier and a toner image formed on a first image carrier to both sides of a sheet at the same time, the belt 10 is moved in the reverse direction to the reference position after the transfer of the toner image to the second image carrier. It is therefore not necessary to wait until the belt 10 completes one full turn, thereby saving time. The reverse movement of the belt 10 is effective not only in the duplex print mode but also in the simplex print mode. Particularly, productivity is noticeably enhanced because the reverse movement of the belt 10 occurs at a speed two times as high as the speed of the forward movement.
In any one of the specific configurations described above, when a toner image to be transferred to the belt or second image carrier 10 has a large size in the direction of movement of the belt, the reverse movement of the belt 10 sometimes lowers productivity. For example, when the image size in the above direction is close to the circumferential length of the belt 10 , it is rather desirable to cause the belt 10 to simply complete one turn than to reverse it. In this respect, the belt 10 should preferably be selectively reversed or continuously moved forward by one turn in accordance with the image size in the direction of movement of the belt 10 . More specifically, the belt 10 should preferably be continuously moved by one turn when the image size is larger than a preselected size.
For example, assume that the maximum image size that can be transferred to the belt 10 is size A 3 in a profile position, i.e., 420 mm in the direction of movement of the belt 10 . Then, the belt 10 is reversed for image sizes smaller than A 4 in a landscape position, i.e., 210 mm in the above direction or continuously moved forward by one turn for the image size of A 4 in a landscape position or above. While the configurations using two image transferring means satisfactorily work without regard to such selective movement of the belt 10 , even the condition with a single image transferring means can cope with the selective movement by inverting the polarity of a toner image while moving the belt 10 forward. In any case, the control over the belt 10 stated above prevents productivity from being lowered when image size is large or improves productivity when image size is small.
FIGS. 8A and 8B are graphs comparing a printing time achievable with the illustrative embodiment that varies the running condition of the belt or second image carrier 10 (reverse movement and acceleration) and a printing time particular to a conventional printer. In FIGS. 8A and 8B , the maximum size that can be transferred to the belt 10 is assumed to be the A 3 profile size while the belt 10 is assumed to move at a speed of 100 mm/sec.
As shown in FIG. 8A , in the conventional printer, the printing time is fixed because a single print is produced by one full turn of a belt. Therefore, 8 seconds are necessary for images for size A 4 to be formed on both sides of a sheet. More specifically, 6 seconds are necessary even up to the end of transfer of the second image, i.e., 4 seconds for the belt to make one turn and 2 seconds for the formation of the second side.
By contrast, as shown in FIG. 8B , the illustrative embodiment needs only about 5 seconds for forming toner images of size A 4 on both sides of a sheet. More specifically, it takes 2 seconds for the first side to be formed, 1 second for the belt 10 to be moved in the reverse direction, and 2 seconds for the second side to be formed. Further, when toner images of size A 6 are to be formed on both sides of a sheet with the belt 10 being moved in the reverse direction, it takes 1 second for the first side to be formed, 0.5 second for the belt 10 to be reversed, and 1 second for the second side to be formed, i.e., about 2.5 seconds in total. In this respect, in the conventional system, 5 seconds are necessary up to the end of image transfer, i.e., 4 seconds for one turn of the belt and 1 second for the formation of the second side.
As stated above, assuming that the maximum size that can be transferred to the belt 10 is the A 3 profile size, then the illustrative embodiment reduces the printing time when the image size is smaller than the A 4 landscape size. When the image size is the A 4 profile size or above, the above-described control that does not reverse the belt 10 should only be executed in accordance with the image size.
An alternative embodiment of the present invention will be described hereinafter. The alternative embodiment accelerates, after the transfer of a toner image from the first image carrier to the second image carrier, the second image carrier while moving it forward. This acceleration corresponds to varying of the running condition of the second image carrier. The illustrative embodiment is also practicable with any one of the configurations described with reference to FIGS. 1 through 4 . Control particular to the illustrative embodiment will be described with reference to FIGS. 9A through 9F , which correspond to FIGS. 5A through 5F , respectively. In FIGS. 9A and 9E , while the drum 1 and belt 10 are shown as being spaced from each other, they are, in practice, held in contact with each other.
First, as shown in FIG. 9A , the charger 4 uniformly charges the surface of the drum 1 to negative polarity. The writing unit scans the charged surface of the drum 1 with the laser beam L to thereby form a latent image. The developing device 5 develops the latent image with negatively charged toner, which is represented by black dots in FIG. 9A , thereby producing a corresponding toner image. Subsequently, the first image transferring means 21 , which is applied with a positive voltage, transfers the toner image from the drum 1 to the belt 10 (primary image transfer).
As shown in FIG. 9B , the primary image transfer of the first toner image ends. Subsequently, as shown in FIG. 9C , the belt 10 is released from the drum 1 in the direction Ki and then moved at a speed two times as high as the previous or usual speed.
As shown in FIG. 9D , as soon as the belt 10 reaches the reference position, it is again moved at the usual speed and brought into contact with the drum 1 in the direction K 2 . On the other hand, a second toner image of negative polarity starts being formed on the drum 1 . The sheet P is driven by the registration roller pair 28 at such a timing that the first and second images are accurately positioned on the sheet P.
The movement of the belt 10 to the reference position can be sensed on the basis of a period of time to elapse since the exposure for the first toner image or the previously mentioned timing mark provided on the belt 10 . With this kind of scheme, it is possible to vary the belt speed and control belt movement. This can be done in terms of the number of steps in the case of a stepping motor.
As shown in FIG. 9E , the first image transferring means 21 , which is applied with a positive voltage, transfers the second toner image of negative polarity from the drum 1 to the sheet P (secondary image transfer. At this instant, the first side of the sheet P is overlaid on the first, image carried on the belt 10 .
Finally, as shown in FIG. 9F , the second image transferring means 22 , which is also applied with a positive voltage, transfers the first image of negative polarity from the belt 10 to the sheet P (tertiary image transfer). The belt 10 in movement conveys the sheet P carrying the first and second images thereon to the fixing position. The fixing means 18 and 30 B are heated, or turned on, to fix the first and second images on the sheet′P. At this instant, the belt cleaner 25 is pressed against the belt 10 for removing toner left on the belt 10 . In the specific configuration shown in FIG. 3 , the sheet P separated from the belt 10 is conveyed to the fixing position.
FIGS. 10A through 10F demonstrate another specific procedure available with the illustrative embodiment and uses the polarity switching device 50 like the procedure of FIGS. 7A through 7F . The polarity switching device 50 is fixed in place. Again, while the drum 1 and belt 10 are shown as being spaced from each other, they are, in practice, held in contact with each other.
First, as shown in FIG. 10A , the charger 4 uniformly charges the surface of the drum 1 to negative polarity. The writing unit scans the charged surface of the drum 1 with the laser beam L to thereby form a latent image. The developing device 5 develops the latent image with negatively charged toner, which is represented by black dots in FIG. 10A , thereby producing a corresponding toner image. Subsequently, the image transferring means 21 , which is applied with a positive voltage, transfers the toner image from the drum 1 to the belt 10 (primary image transfer). While the belt 10 conveys the toner image forward, the polarity switching means 50 is applied with a positive voltage, or turned on, to switch the polarity of the toner image from negative to positive.
As shown in FIG. 10B , when the trailing edge of the toner image moves away from the polarity switching device 50 , the entire toner image carried on the belt 10 has been inverted in polarity. Subsequently, as shown in FIG. 10C , the belt 10 is released from the belt 10 in the direction K 1 and then moved at a speed two times as high as the previous or usual speed.
As shown in FIG. 10D , when the belt 10 reaches the reference position, it is again moved at the usual speed and brought into contact with the drum 1 in the direction K 2 . On the other hand, a second toner image of negative polarity starts being formed on the drum 1 . The sheet P is driven by the registration roller pair 28 at such a timing that the first and second toner images are accurately positioned on the sheet P.
As shown in FIG. 10E , the image transferring means 21 , which is applied with a positive voltage, transfers the toner image of positive polarity carried on the belt 1 and the second toner image of negative polarity formed on the drum 1 to the sheet P at the same time.
Finally, as shown in FIG. 10F , the belt 10 in movement conveys the sheet P carrying the first and second images thereon to the fixing position. The fixing means 18 and 30 B are heated, or turned on, to fix the first and second images on the sheet P. At this instant, the belt cleaner 25 is pressed against the belt 10 for removing toner left on the belt 10 . In the specific configuration shown in FIG. 3 , the sheet P separated from the belt 10 is conveyed to the fixing position.
In the procedure shown in FIGS. 10A through 10 F, in the simplex print mode, a toner image is directly transferred from the drum 1 to the sheet P without the polarity switching device 50 being operated, i.e., in exactly the same manner as when two image transferring means are used.
In the procedure of FIGS. 10A through 10F , when a toner image is transferred from the drum 1 to the sheet P by way of the belt 10 in the simplex print mode, the polarity switching device 50 is operated to invert the polarity of the toner image. Such image transfer is executed in the same manner as in the duplex print mode except that the second image is not formed on the drum 1 .
As stated above, after the transfer of the toner image to the belt or second image carrier 10 , the illustrative embodiment accelerates the movement of the belt 10 up to the reference position. This successfully reduces a period of time necessary for the belt 10 to complete one turn and therefore the image forming time. The acceleration of the belt 10 is effective not only in the duplex print mode but also in the simplex print mode. Stated another way, the illustrative embodiment improves productivity by varying the running condition of the belt 10 .
When a toner image of maximum size is to be transferred to the belt 10 , the illustrative embodiment does not accelerate the movement of the belt 10 . This is because when such a toner image is transferred to the belt 10 , the leading edge of the toner image reaches a position adjacent the secondary image transfer position when the trailing edge of the same is transferred from the drum 1 to the belt 10 or when it moves away from the polarity switching device 50 .
So long as the image size to be transferred to the belt 10 is smaller than the maximum size, which is the A 3 profile size or 420 mm in the direction of movement of the belt 10 , the illustrative embodiment accelerates the movement of the belt 10 without exception to thereby enhance productivity. For example, the illustrative embodiment reduces the printing time to 85% with the A 4 profile size, to 80% with the B 5 profile size, to 75% with the A 4 landscape size or to 65% with the A 6 landscape size, compared to the conventional apparatus.
A specific configuration for moving the belt 10 included in any one of the illustrative embodiments into or out of contact with the drum 1 will be described hereinafter with reference to FIG. 11 . As shown, the belt unit 20 includes a box-like frame 51 supporting the belt 10 thereinside. The rollers 11 through 13 are journalled to the frame 51 while the belt 10 is passed over the rollers 11 through 13 . A tie bar or reinforcing member 51 b connects the upper ends of opposite side walls of the frame 51 . The fixing roller 18 , image transfer roller 21 and so forth not relevant to the understanding of the specific configuration are not shown in FIG. 11 .
A pulley 52 is mounted on one end of the roller 11 while a drive belt 54 is passed over the pulley 52 and a pulley mounted on the output shaft of a stepping motor 53 . The stepping motor 53 is selectively driven in the forward or the reverse direction to thereby drive the belt 10 in the forward or the reverse direction. The stepping motor 53 is independent of a motor assigned to the drum or first image carrier 1 .
The shaft of the roller 11 is journalled to the printer body or body frame, so that the belt unit 20 is angularly movable about the shaft of the roller 11 . Springs 56 constantly bias the frame 51 upward toward the drum 1 at the bottom of the roller 13 , thereby pressing the belt 10 against the drum 1 with preselected pressure. A member, not shown, included in the frame 51 abuts against a support member, which support the drum 1 , for thereby accurately positioning the belt 10 and drum 1 relative to each other.
Bosses 55 protrude sideways from the end of the frame 51 adjacent to the roller 13 and are received in notches 58 formed in a generally U-shaped yoke 57 . A shaft 59 extends throughout the intermediate portions of opposite side walls of the yoke 57 and is journalled to the body frame. A stub 60 protrudes from the end wall of the yoke 57 . A solenoid 61 is mounted on the body frame above the stub 60 and includes a plunger 62 . A spring 63 is anchored to the plunger 62 and stub 60 at opposite ends thereof.
In operation, when the solenoid 61 is energized, the plunger 62 thereof is retracted while causing the yoke 57 to angularly move counterclockwise about the shaft 59 , as indicated by an arrow M in FIG. 11 . Consequently, the bosses 55 of the frame 51 are forced downward against the action of the springs 56 and causes the belt unit 20 to bodily move about the shaft 11 clockwise, as indicated by an arrow N in FIG. 11 , thereby releasing the belt 10 from the drum 1 . When the solenoid 61 is deenergized, the plunger 62 is projected with the result that the belt unit 20 is moved in the direction opposite to the direction N by the springs 56 , again bringing the belt 10 into contact with the drum 1 . At this instant, the yoke 57 is, of course, moved in the direction opposite to the direction M.
Reference will be made to FIGS. 12 and 13A through 13 C for describing a specific mechanism for protecting the belt 10 from offset, i.e., preventing it from being dislocated sideways. In FIG. 12 , structural elements identical with the structural elements of FIG. 11 are not labeled.
As shown in FIGS. 13A through 13C , the roller 12 over which the belt 10 is passed is slightly tiltable from the horizontal position. More specifically, a slot 51 a is formed in the frame 51 through which one shaft 12 a of the roller 12 extends, allowing the roller 12 to tilt. The other shaft 12 b of the roller 12 is supported by the frame 51 via a bearing 64 . A lever 66 is connected to the shaft 12 a via a bearing 65 . As shown in FIG. 12 , the lever 66 is angularly movably supported by a shaft 67 protruding from the frame 51 .
Pins 68 and 69 are studded on opposite surfaces of the lever 66 at the end of the lever 66 remove from the roller 12 . A tension spring 70 is anchored to the pin 69 and frame 51 at its opposite ends, constantly biasing the pin 69 downward, i.e., biasing the lever 66 counterclockwise in FIG. 12 . A solenoid 72 is mounted on the frame 51 via a bracket 71 and includes a plunger 73 . A hook 74 is connected to the lower end of the plunger 73 and anchored to the pin 69 .
When the solenoid 72 is deenergized, the pin 69 of the lever 66 is pulled downward by the tension spring 70 while pulling out the plunger 73 . Consequently, the lever 66 is angularly moved clockwise in FIG. 12 to thereby lift the shaft 12 a , as shown in FIG. 13A . In this condition, the roller 12 is slightly tilted from the horizontal position, i.e., raised at the shaft 12 a side. Therefore, the belt 10 in turn tends to move toward the shaft 12 a side of the roller 12 , as indicated by an arrow in FIG. 13A .
FIG. 13B shows the belt 10 shifted to the shaft 12 a side.
As shown in. FIG. 13C , when the solenoid 72 is energized, the plunger 73 is retracted while lifting the pin 68 against the action of the spring 70 , so that the lever 66 angularly moves clockwise in FIG. 12 . As a result, the roller 12 is slightly tilted from the horizontal position, i.e., lowered at the shaft 12 a side. In this condition, the belt 10 in turn tends to move toward the shaft 12 b side, as indicated by an arrow in FIG. 13C .
Further, a spot 75 is provided on one end portion of the roller 12 adjoining the shaft 12 a . A sensor 76 is mounted on the inner surface of the frame 51 and emits a light beam toward the spot 75 . When the belt 10 is shifted toward the shaft 12 a , the belt 10 hides the spot 75 . The resulting output of the sensor 76 indicates that the belt 10 has been shifted toward the shaft 12 a . In this case, the solenoid 72 is energized to slightly lower the shaft 12 a side of the roller 12 for thereby correcting the offset of the belt 10 .
A spot and a sensor may also be located at the shaft 12 b side of the roller 12 , in which case, the solenoid 72 will be turned on or turned off in accordance with two sensor outputs.
The offset of the belt 10 can be corrected without resorting the mechanism of FIG. 12 if the belt 10 is moved in the reverse direction at a preselected timing over a preselected period of time. In any case, the offset of the belt 10 can be adequately controlled.
Some different configurations to which any one of the illustrative embodiments shown and described is applicable will be described hereinafter.
FIG. 14 shows a full-color image forming apparatus including an image forming section PU arranged substantially at the center of the apparatus body. In the image forming section PU, four image forming units SU are arranged side by side along and in contact with the lower run of an inclined, intermediate image transfer belt 60 . An optical writing unit 7 is positioned below the image forming sections SU. Because the image forming units SU are identical in configuration except for the color of toner, only one of them will be described with reference to FIG. 15 .
As shown in FIG. 15 , each image forming unit SU includes the drum 1 around which the drum cleaner 2 , discharger 3 , charger 4 and developing device 5 are arranged. The developing device 5 stores any one of cyan toner, magenta toner, yellow toner and black toner and develops a latent image formed on the drum 1 . The writing unit 7 scans the charged surface of the drum 1 with the laser beam L at the position between the charger 4 and the developing device 5 . More specifically, using conventional laser optics, the writing unit 7 forms the latent image on the drum 1 in accordance with image data corresponding in color to the toner stored in the developing device 5 . The laser optics may be replaced with an LED (Light Emitting Diode) array and focusing means, if desired. An image transfer roller 65 faces the drum 1 with the intermediary of the intermediate image transfer belt (simply belt hereinafter) 60 . The reference numeral 66 designates a back roller. The image transfer roller 65 transfers the toner image formed on the drum 1 to the belt 60 .
Referring again to FIG. 14 , the belt 60 is passed over a drive roller 61 and a driven roller 62 and caused to turn counterclockwise by the drive roller 61 . Members disposed in the loop of the belt 60 except for the image transferring means are suitably grounded via the apparatus body. The belt cleaner 25 faces the driven roller 62 via the belt 60 . A toner replenishing section TS is positioned above the belt 60 and includes toner cartridges TC, i.e., a through d each storing toner of a particular color. Powder pumps, not shown, replenish the toner of different colors from the toner cartridges a through d to the developing devices. In a full-color print mode, a cyan, a magenta, a yellow and a black toner image formed on the drums 1 by the four image forming units SU, respectively, are sequentially transferred to the belt 60 one above the other, forming a full-color image. In a monochromatic print mode, only the image forming apparatus SU storing the black toner forms a monochromatic toner image; the toner image is transferred to the belt 60 . In the configuration shown in FIG. 14 , among the four image forming units SU, the most downstream unit d stores the black toner in order to prevent productivity from being lowered in the monochromatic print mode.
Another intermediate image transfer belt or body 110 is positioned at the right-hand side of the image forming section PU. The intermediate image transfer belt (simply belt hereinafter) 110 is passed over rollers 111 , 112 , 113 and 115 . The roller 111 is a drive roller driven by a stepping motor independent of the motor assigned to the drum 1 and belt 60 , causing the belt 110 to turn. The belt 110 is angularly movable about the drive roller 111 , as indicated by a double-headed arrow K. A moving mechanism, which will be described later, so moves the belt 110 into or out of contact with the belt 60 .
The belt 10 is heat-resistant and provided with resistance that allows toner to be transferred to the belt 110 . A mark, not shown, is provided on the belt 110 for controlling the system. In the event of power-up, the mark on the belt 10 is optically sensed to bring the belt 110 to a preselected reference or initial position.
The image transfer roller or first image transferring means 21 is positioned between the opposite runs of the belt 110 in the vicinity of the roller 61 supporting the belt 60 . The heat roller 18 , back rollers 114 and 115 and a back plate BP are also arranged inside of the loop of the belt 110 . The roller 112 plays the role of cooling means at the same time. The members inside the loop of the belt 110 except for the image transferring means are suitably grounded via the apparatus body. A belt cleaner 250 , the charger or second image transferring means 22 and so forth are arranged outside of the loop of the belt 110 . The belt cleaner 250 assigned to the belt 110 includes a cleaning roller 250 A, a blade 250 B and toner conveying means 250 C and wipes off toner left on the belt 110 after the transfer of a full-color image to a sheet. The belt cleaner 250 is angularly movable about a fulcrum 250 D into or out of contact with the belt 110 . In FIG. 14 , the roller 250 A is shown as being released from the belt 110 . More specifically, the belt cleaner 250 is released from the belt 110 when a toner image to be transferred to a sheet is present on the belt 110 , but brought into contact with the belt 110 when cleaning is required.
The image transfer roller 21 , back roller 115 and roller 61 supporting the belt 60 cooperate to press the belts 60 and 110 against each other for thereby forming a preselected nip for image transfer. The charger 22 is positioned outside of the loop of the belt 110 and faces the back plate BP, which is positioned above the image transfer roller 21 .
Two sheet cassettes 26 - 1 and 26 - 2 are positioned one above the other below the image forming section PU. The pickup roller 27 associated with designated one of the sheet cassettes 26 - 1 and 26 - 2 pays out the sheets P one by one toward the registration roller pair 28 via the guides 29 .
The fixing device 30 faces the heat roller 18 with the intermediary of the belt 110 . The fixing device 30 is angularly movable as in FIG. 1 such that the fixing roller 19 selectively moves into or out of contact with the belt 110 . FIG. 14 shows the fixing roller 19 in a position where it contacts the belt 110 .
The operation of the printer shown in FIG. 14 will be described hereinafter. On the power-up of the printer, the belt 110 is brought to its reference or initial position on the basis of the mark provided thereon.
In the duplex print mode, a first toner image to be transferred to the first side of a sheet P is formed by the image forming section PU and then transferred from the belt 60 to the belt 110 , which is turning clockwise or forward. Subsequently, a second toner image is formed by the image forming section PU. At this instant, the second image transferring means 22 , fixing device 30 and belt cleaner 250 are released from the belt 110 or otherwise held inoperative so as not to disturb the toner image.
After the entire first toner image has been transferred from the drum 60 to the belt 110 , the belt 110 is reversed in the counterclockwise direction to the preselected position. The distance over which the belt 110 is reversed is controlled in terms of the number of steps of the stepping motor or drive means. In this specific configuration, the belt 110 is reversed at a speed two times as high as the speed of forward movement. The belt 110 is released from the belt 60 before the start of reverse movement. As soon as the belt 110 is returned to the preselected position, it is again brought into contact with the belt 60 and moved forward or clockwise.
On the other hand, a second toner image to be transferred to the second side of the same sheet P is formed by the image forming section PU. At the same time, the top sheet of designated one of the sheet cassettes 26 - 1 and 26 - 2 is paid out by the pickup roller 27 and conveyed toward the registration roller pair 28 .
The second toner image is transferred from the belt 60 to the second side of the sheet P conveyed by the registration roller pair 28 at the preselected timing. This image transfer is effected by the image transfer roller or first image transferring means 21 positioned inside of the loop of the belt 110 . At this time, the first image present on the belt 110 has been returned to the preselected position and is therefore overlaid on the first side of the sheet P. The sheet P carrying the second toner image on one side or second side and overlaid on the first image at the other side is conveyed by the belt 110 upward. The charger or second image forming means 22 transfers the first toner image from the belt 110 to the first side of the sheet P.
When the sheet P carrying the first and second toner images thereon reach the fixing device 30 , the fixing roller 19 and heat roller 18 fix the toner images on the sheet P. For this purpose, the fixing roller 19 is brought into pressing contact with the heat roller 18 via the belt 110 . Subsequently, the sheet P is separated from the belt 110 by curvature at the position where the roller 111 is located, and then driven out to the stack portion 40 by the roller pair 34 . The belt 110 is continuously turned forward even after the separation of the sheet P, so that the belt cleaner 250 cleans the surface of the belt 110 .
In the simplex print mode, a toner image formed by the image forming section PU is directly transferred from the belt 60 to a sheet P without the intermediary of the belt 110 . In this case, the belt 110 should only be turned forward in synchronism with the belt 60 without any reverse movement.
As stated above, a toner image formed by the image forming section PU is transferred from the belt 60 to either one of the sheet P and belt 110 . In this sense, the belts 60 and 110 play the role of the first and second image carriers, respectively.
Again, after the transfer of a toner image to the belt or second image carrier 110 , the belt 110 is reversed to the preselected position. It is therefore not necessary to wait until the belt 110 complements one full turn, promoting rapid image formation. Particularly, productivity is enhanced because the belt 110 is moved at a higher speed during reverse movement than during forward movement.
Assume that the maximum image size that can be transferred to the belt 110 is the A 3 profile size or 420 mm in the direction of rotation of the belt 110 . Then, the belt 110 is reversed if the image size is smaller than the A 4 landscape size or 210 mm, but is not done so if the image size is the A 4 landscape size or above. This successfully preserves high productivity when the image size is large or improves productivity when the image size is small.
In the specific configuration shown in FIG. 14 , the image transfer roller or first image transferring means 21 is disposed in the loop of the belt 110 and applied with a charge opposite in polarity to the toner so as to transfer the toner by attraction. Alternatively, the first image transferring means may be disposed in the loop of the belt 60 , e.g., the roller 61 may be implemented as an image transfer roller and applied with a charge of the same polarity as the toner, in which case the toner will be transferred by repulsion. In this alternative arrangement, the roller 21 in the loop of the belt 110 may be implemented as a grounded back roller.
FIGS. 16A and 16B show a specific configuration of the mechanism for moving the belt or second image carrier 110 into or out of contact with the belt 60 . As shown, the rollers over which the belt 110 is passed are journalled to a frame 120 , which is angularly movable about the shaft of the roller 111 . A spring 122 is loaded between the frame 120 and the printer body for constantly biasing the frame 120 clockwise, as viewed in FIGS. 16A and 16B . A solenoid 121 is mounted on the printer body above the frame 120 and has a plunger connected to the frame 120 .
As shown in FIG. 16A , when the solenoid 121 is deenergized, the belt is pressed against the belt 60 under the action of the spring 122 . As shown in FIG. 16B , when the solenoid 121 is energized, it causes the frame 120 to angularly move counterclockwise away from the belt 60 against the action of the spring 22 . The belt 110 is held in the position of FIG. 16 B′when reversed at the higher speed.
FIGS. 17A and 17B show another specific configuration of the moving mechanism. As shown, this moving mechanisms does not move the entire frame supporting the belt 110 , but moves only a belt support roller 115 with, e.g., a solenoid for thereby moving the belt 110 into or out of contact with the belt 60 . The image transfer roller 21 may be moved integrally with the belt support roller 115 , if desired. It is preferable to provide an arrangement that maintains the belt 110 under tension when the belt 110 is spaced from the belt 60 .
FIGS. 18A through 18C show a specific mechanism for sensing the position of the belt 110 in a top plan view, a side elevation and a front view, respectively. As shown, timing marks 123 a and 123 b are provided on the outer surface of the belt 110 adjacent opposite edges of the belt 110 in the widthwise direction. The distance between the timing marks 123 a and 123 b is selected to be one-half of the circumferential length of the belt 110 . Sensors 124 a and 124 b , which respectively sense the timing marks 123 a and 123 b , adjoin the opposite edge portions of the belt 110 and face the portion of the belt 110 adjacent the image transfer roller 21 , but slightly above the roller 21 . The timing marks 123 a and 123 b are painted in a color different from the color of the surface of the belt 110 . The sensors 124 a and 124 b may be implemented as a reflection type photosensor each.
The timing marks 123 a and 123 b and sensors 124 a and 124 b are used to control the position of the belt 110 , i.e., movement to the reference or initial position and variation of the running condition. While the position of the belt 110 can be controlled with a single timing sensor and a single sensor, two timing marks 123 a and 123 b and two sensors 124 a and 124 b are successful to extend the life of the belt 110 . Particularly, in the configuration that reverses the belt 110 and when images of small sizes are frequently formed, the timing marks 123 a and 123 b spaced from each other by the previously stated distance prevent only the same portion of the belt 110 from being repeatedly used for thereby protecting the belt 110 from deterioration
FIG. 19 is a timing chart demonstrating the operation of the printer to occur in the duplex print mode. As shown, on the elapse of periods of time T 1 a , t 1 b , t 1 c and t 1 d since the sensor 124 a or 124 b has sensed the timing mark 123 a or 123 b , the yellow, magenta, cyan and black developing sections 5 a through 5 d of the image forming unit SU, respectively, start development. On the elapse of a period of time t 2 since the sensing of the timing mark, primary image transfer is effected from the drums 1 of the image forming unit SU to the belt or first image carrier 60 by the image transferring means 65 . Further, on the elapse of a period of time t 3 since the sensing of the timing mark, secondary image transfer is effected from the belt 60 to the belt or second image carrier 110 by the image transferring means 21 .
After the secondary image transfer, the solenoid 121 of the moving mechanism is energized to release the belt 110 from the belt 60 . At the same time, the motor assigned to the belt 110 is stopped and then reversed at the higher speed. When the belt 110 is returned to the preselected position, as determined by sensing the timing mark 123 a or 123 b , the above motor is stopped and then driven forward at the lower or usual speed. Such a procedure is repeated up to the last image. On the elapse of a period of time t 4 since the end of return of the belt 110 , the registration roller 28 is driven to convey a sheet. Subsequently, on the elapse of a period of time t 5 , tertiary image transfer is effected by the image transferring means 22 .
When the belt 110 is reversed, the same number of pulses as when it is moved forward are fed to the stepping motor, but within half a period of time, thereby doubling the belt speed. Such control over the stepping motor is demonstrated in FIG. 20 .
While the configuration of FIG. 14 uses the first embodiment that reverses the belt 110 , it may alternatively use the second embodiment that accelerates the belt 110 in the forward direction. In the first embodiment, a single image transferring means and a polarity switching device may be used to transfer images to both sides of a sheet at the same time, as described with reference to FIGS. 6A through 6F or 7 A through 7 F. This is also true with the second embodiment, as described with reference to FIGS. 10A through 10F . Further, the fixing device may have the configuration shown in FIG. 2 or 3 .
As shown in FIG. 21 , the unit including the belt or second image carrier 110 is configured to be openable away from the printer body. The openable unit additionally includes the members and devices arranged inside of the loop of the belt 110 as well as the belt cleaner 250 . Upper one and lower one of the outlet rollers 34 , respectively labeled 34 a and 34 b , are mounted on the openable unit and printer body, respectively. When the openable unit is opened away from the printer body, the sheet path extending from the sheet feed section to the outlet roller pair 34 is uncovered to facilitate access in the event of a jam.
FIG. 22 shows a modification of the configuration described with reference to FIG. 14 . As shown, a fixing device 30 C is positioned outside of the loop of the belt 110 . The belt cleaner 250 assigned to the belt 110 differs in configuration and position from the belt cleaner 250 of FIG. 14 . As shown in FIG. 23 , the unit including the belt 110 is also configured to be openable away from the printer body. In the modification, the fixing device 30 C is mounted on the printer body and remains thereon when the openable unit is opened.
FIG. 24 shows another specific construction identical with the construction of FIG. 14 or 22 except for the arrangement of the image forming section PU. As shown, the belt or first image carrier 60 is passed over three rollers 61 , 62 and 63 in a triangular position. Four image forming units SU are arranged side by side along the lower run of the belt 60 . The optical writing unit 7 is located below the image forming units SU in a horizontal position. As for the rest of the configuration, FIG. 24 is identical with FIG. 22 . Again, the unit including the belt 110 is openable away from the printer body.
Referring to FIG. 25 , a specific system including two printers connected to a host computer HC by a network will be described. The two printers each may have any one of the specific configurations shown in FIGS. 14 , 22 and 24 . The network may be either wired or wireless. Labeled OP in FIG. 25 is an operation panel.
As best shown in FIG. 14 , the printer of FIG. 14 , 22 or 24 includes a cover 40 A constituting the bottom of the stack portion 40 and openable about a shaft 40 B. As shown in FIG. 25 , when the cover 40 A is opened, toner cartridges can be easily dealt with. Because the shaft 40 B adjoins the outlet roller pair 34 , prints stacked on the stack portion 40 are prevented from dropping even when the cover 40 A is opened.
As shown in FIG. 25 , a door 67 mounted on the front of each printer is openable about its left edge for uncovering the image forming section PU in the event of, e.g., maintenance. The belt 60 , four image forming units SU and members arranged therearound constituting the image forming section PU can be pulled out of the printer body with the writing unit 7 being left on the printer body. Subsequently, the belt 60 and image forming units SU can be dismounted independently of each other. The image forming section PU is guided by guide rails, not shown, so that it can be easily, surely pulled out. The door 67 is hinged to the printer body in the vertical direction, making the members arranged in the lower portion to be easily seen in the event of maintenance. Moreover, sheets can be easily replenished to the sheet cassettes 26 - 1 and 26 - 2 even when the door 67 is open. A seal member, not shown, prevents the structural elements of the writing device 7 from being smeared by toner. A controller, not shown, allows the writing device 7 to selectively form a non-reversed image or a reversed or mirror image, as needed.
The sheet cassettes 26 - 1 and 26 - 2 each can be pulled out toward the front of the printer body for the replenishment or the replacement of sheets. In the printer shown in the right part of FIG. 25 , the door 67 is opened while the sheet cassette 26 - 2 is pulled out.
A specific configuration of the printer including a plurality of first image carriers and a second image carrier movable into and out of contact with the first image carriers will be described hereinafter with reference to FIG. 26 . Either one of the first and second embodiments described above may be applied to the configuration to be described. As shown in FIG. 26 , the image forming section PU capable of forming a full-color image is located at substantially the center of the printer. Four image forming units SU are arranged side by side along the upper run of the belt 110 . The optical writing unit 7 is positioned above the image forming units SU. The image forming units SU are identical in configuration except for the color of toner. Each image forming unit SU is identical with the image forming unit shown in FIG. 15 except for the positional relation between the structural elements. In FIG. 26 , a group of image carriers made up of the four image forming units SU (a through d) constitutes a first image carrier in combination. It is to be noted that the first image carrier, or group of image carriers, may include any desired number of image forming units. For example, the black image forming unit may be omitted or may be combined with the red and blue image forming units.
In FIG. 26 , the developing device 5 of each image forming unit stores one of cyan, magenta, yellow and black toner and develops a latent image formed on the associated drum with the toner. In the monochromatic print mode, only the image forming unit assigned to black forms an image. In the specific configuration shown in FIG. 26 , the image forming unit SU-d located at the highest level or most downstream position is assigned to black so as to prevent an image from being disturbed by the other image forming units.
As shown in FIG. 27 in detail, the first image transferring means 21 are arranged in the loop of the belt 110 for transferring toner images from the drums 0 . 1 to the belt 110 or transferring them directly to the upper surface of a sheet. The second image transferring unit for transferring a toner image from the belt 110 to the lower surface of the sheet is implemented as the charger 22 located downstream of the image forming unit SU-d.
The belt or second image carrier is passed over the rollers 111 through 114 and movable counterclockwise, as viewed in FIG. 27 . Devices arranged inside of the loop of the belt 110 are suitably grounded via the printer body. A belt cleaner 250 faces the belt 110 at a position where the driven roller 113 is located. A moving mechanism, which will be described later, causes the belt 110 to selectively move about the shaft of the roller 111 into or out of contact with the in a direction K into or out of contact with the image forming units SU or first image carrier.
As shown in FIG. 26 , the two sheet cassettes 261 and 26 - 2 are stacked one above the other in the lower portion of the printer body. The pickup roller 27 associated with designated one of the sheet cassettes 26 - 1 and 26 - 2 pays out the top sheet from the cassette. Electric units E 1 and E 2 are located above the sheet cassette 26 - 1 . A toner container 70 is positioned at the top right corner of the printer body. Toner is replenished from the toner container 70 to corresponding one of developing devices via a powder pump not shown. The top of the printer body constitutes the stack portion or print tray 40 . A fixing device 30 D is located downstream of the image forming unit SU-d assigned to black and uses a belt. As shown in FIG. 27 , the belt 110 is mounted on a unit frame 67 angularly movable about the shaft of the roller 111 . An eccentric cam 68 is affixed to a shaft 69 and held in contact with the bottom of the frame 67 . When the cam 68 is caused to rotate, it moves the unit frame 67 in the direction K with the result that the belt 110 is angularly moved into or out of contact with the image forming units SU. The belt 110 may be angularly moved about the roller 112 , if desired.
More specifically, as shown in FIG. 28 , two eccentric cams 68 are mounted on opposite ends of a shaft 69 . A joint 71 is affixed to the outside surface of one of the cams 68 located at the rear side of the printer body. The joint 71 is configured to receive projections formed on one end of a shaft 72 . A gear 73 is affixed to the other end of the shaft 72 and provided with a clutch 74 . The clutch 74 is selectively coupled or uncoupled to establish or interrupt, respectively, drive transmission from a motor, not shown, to the gear 73 . A photointerrupter 76 is so positioned as to sense a feeder portion 75 included in the joint 71 .
When the motor rotates the gear 73 via the clutch 74 , the shaft 69 and therefore the cams 68 are rotated via the shaft 72 and joint 71 , raising or lowering the unit frame 67 . At this instant, the photo interrupter 76 senses the feeler portion 75 of the joint 71 and therefore the position of the eccentric cams 68 . The position of the belt 110 is controlled in accordance with the output of the photointerrupter 76 .
In FIG. 27 , the cams 68 in rotation cause the unit frame 67 to angularly move about the roller 111 in the direction K. Therefore, when each cam 68 is brought to a position indicated by a phantom line in FIG. 27 , it raises the unit frame 67 and therefore the belt 110 . Consequently, the upper run of the belt 110 contacts the four image forming units SU-e through SU-d, i.e., the drums 1 , as indicated by a phantom line in FIG. 27 . When the cam 68 is brought to a position indicated by a solid line in FIG. 27 , the unit frame 67 and therefore the belt 110 is released from the image forming units SU-a through SU-d, as indicated by a solid line in FIG. 27 .
In operation, in the full-color print mode, toner images formed in cyan, magenta, yellow and black on the drums 1 of the four image forming units or first image carrier SU are sequentially transferred to the belt 110 one above the other, completing a full-color image. In the monochromatic print mode, a black toner image is transferred from the image forming unit SU-d to the belt 110 . In any case, such image transfer is effected by the image transfer rollers or first image transferring means 21 . Of course, the belt or second image carrier 110 is held in contact with the drums 1 during image transfer.
In the duplex print mode, after the entire first toner image to be transferred to the first side of a sheet has been transferred to the belt 110 , the belt 110 is released from the image forming units or first image carrier SU and then reversed to a preselected position. The distance of reverse movement is controlled on the basis of the number of steps of the stepping motor assigned to the belt 110 . Again, the belt 110 is reversed at a speed two times as high as the speed of forward or usual movement. When the belt 110 reaches the preselected position, it is again brought into contact with the image forming units SU and caused to rotate forward, i.e., counterclockwise in FIG. 26 at the usual speed.
On the other hand, a second toner image to be transferred to the second side of the same sheet is formed by the image forming units SU. At the same time, a sheet is fed from designated one of the sheet cassettes 26 - 1 and 26 - 2 toward the registration roller pair by the pickup roller 27 . The second toner image is transferred from the image forming units SU to the second side of the sheet. In the monochromatic print mode, a black toner image is transferred from the image forming unit SU-d to the sheet. In any case, the image transfer is effected by the image transfer rollers 21 disposed in the loop of the belt 110 . At this time, the, first toner image on the belt 110 has already been returned to the preselected position and is therefore overlaid on the first side of the sheet. While the sheet carrying the two images on both sides thereof is conveyed upward by the belt 110 , the charger or second image transferring means 22 transfers the first toner image from the belt 110 to the first side of the sheet.
As stated above, after one page of toner image has been transferred to the belt 110 in the duplex print mode, the belt 110 is reversed at the higher speed for thereby enhancing productivity.
In the simplex print mode, toner images are directly transferred from the image forming units SU to a sheet being conveyed by the belt 110 one above the other. To print an image on the lower side of a sheet, it suffices to transfer a toner image to the lower side of a sheet by way of the belt 110 by use of the charger or second image transferring means 22 . In this case, the reverse movement of the belt 110 effected at high speed enhances productivity.
Again, it is rather desirable to cause the belt 10 to simply complete one turn than to move it in the reverse direction, depending on the image size. For example, assume that the maximum image size that can be transferred to the belt 10 is the A 3 profile size. Then, the belt 10 is reversed for an image size smaller than the A 4 landscape size or continuously moved forward by one turn for an image of the A 4 landscape size or above. In any case, such control over the belt 10 prevents productivity from being lowered when the image size is large or improves productivity when the image size is small.
The configuration of FIG. 27 including four image forming units arranged side by side reduces a period of time necessary for forming a full-color image, compared to the configuration that causes a single drum to make four full rotations. This, coupled with enhanced productivity implemented by the first or the second embodiment varying the belt running condition, realizes a printer achieving. a remarkable improvement in productivity in the full-color duplex print mode.
The configuration of FIG. 27 may also include the polarity switching means 50 shown in FIGS. 6A through 6F , 7 A through 7 F or 10 A through 10 F. This allows a single image transferring means 21 to transfer images to both sides of a sheet although the image transferring means should be assigned to each image forming unit.
Further, the fixing device of FIG. 3 using a heat roller may be positioned outside of the loop of the belt 110 or the fixing device of FIG. 1 or 2 may be positioned inside of the loop of the belt 110 . In addition, the first image transferring means 21 may be implemented as a charger, if desired.
In any one of the illustrative embodiments shown and described, the speed of reverse movement of the belt is not limited to a speed two times as high as the usual speed, but may be a speed that is any suitable multiple of the usual speed. The distance of reverse movement of the belt may be controlled on the basis of the output of an encoder mounted on, e.g., the output shaft of a servo motor in place of the number of steps of a stepping motor.
The reference image sized used to selectively reverse the belt is not limited to A 4 , but may be suitably selected in accordance with the circumferential length, conveyance speed and speed of reverse movement of the belt as well as the configurations of the various devices. The moving mechanism for selectively moving the first and second image carriers into or out of contact with each other is open to choice. This is also true with the mechanism for correcting the offset of the belt. The offset correcting mechanism may be applied to the belt or second image carrier 110 shown in any one of FIGS. 14 , 22 , 24 and 26 as well.
The drum may be replaced with a photoconductive belt in any one of the configurations shown in FIGS. 1 , 2 , 3 , 4 and 26 as well. The polarities of the drum, toner, image transfer voltage and so forth are only illustrative and may be reversed each.
The optical writing unit 7 may use an LED array in place of the laser optics or may even use an analog exposing system. In the case of an analog exposing system, a non-reversed image can be formed on the photoconductive element if a mirror is used.
Further, the configurations of the charging means, developing device, first and second image transferring devices, polarity switching device and fixing device shown and described are only illustrative. Of course, the present invention may be implemented as a copier or a facsimile apparatus, if desired.
In summary, it will be seen that the present invention provides an image forming apparatus having various unprecedented advantages, as enumerated below.
(1) Productivity is enhanced in both of the simplex and duplex print modes. Particularly, higher productivity is achievable at low cost in the full-color duplex print mode.
Images can be surely transferred to both sides of a sheet at the same time.
Drive means assigned to a second image carrier is independent of drive means assigned to a first image carrier, allowing the running condition of the second image carrier to be easily controlled.
When the running condition of the second image carrier is varied, the second image carrier can be accurately controlled, enhancing image quality.
Productivity is prevented from falling when image size is relatively large.
An image is free from disturbance during fixation and therefore high quality.
Jam processing and maintenance are easy to perform.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof. | An image forming apparatus including a plurality of photoconductive elements arranged on an inclined plane with respect to the ground, a plurality of developing devices, each of the plurality of developing devices corresponding to one of the plurality of photoconductive elements and configured to develop an image on a corresponding one of the plurality of photoconductive elements and a plurality of mirrors and a polygon mirror disposed inside a single housing and configured to reflect light beams to the plurality of photoconductive elements, the housing being arranged parallel to the inclining plane and below the plurality of photoconductive elements. | 6 |
FIELD OF THE INVENTION
[0001] This invention is directed to a polymer thick film conductive composition. More specifically, the polymer thick film conductive composition may be used in applications where thermoforming of the base substrate occurs. Polycarbonate substrates are often used and the silver conductor may be used without any barrier layer.
BACKGROUND OF THE INVENTION
[0002] Conductive PTF circuits have long been used as electrical elements. Although they have been used for years in these types of applications, the use of PTF silver conductors in thermoforming procedures is not common. This is particularly important in circuits where a highly conductive silver composition is needed after the severe thermoforming process. Additionally, the typical substrate used for thermoforming is polycarbonate and very often the silver is not compatible with this substrate. One of the purposes of this invention is to alleviate these issues and produce a conductive, thermoformable construction in which the printed silver conductor can be used on a substrate of choice such as a polycarbonate.
SUMMARY OF THE INVENTION
[0003] This invention relates to a polymer thick film conductive composition comprising:
[0004] (a) 30-70 wt % silver;
[0005] (b) 10-40 wt % first organic medium comprising 10-50 wt % thermoplastic urethane resin dissolved in a first organic solvent, wherein the weight percent of the thermoplastic urethane resin is based on the total weight of the first organic medium; and
[0006] (c) 10-40 wt % second organic medium comprising 10-50 wt % thermoplastic polyhydroxyether resin dissolved in an organic solvent wherein the weight percent of the thermoplastic polyhydroxyether resin is based on the total weight of the second organic medium;
[0007] wherein the weight percent of the silver, the first organic medium and the second organic medium are based on the total weight of the polymer thick film conductive composition.
[0008] In an embodiment, the polymer thick film conductive composition further comprises:
[0009] (d) 1-20 wt % of a third organic solvent, wherein the third organic solvent is diacetone alcohol and wherein the weight percent is based on the total weight of the polymer thick film conductive composition.
[0010] In one embodiment, the silver is in the form of silver flakes.
[0011] The invention is further directed to using the thermoformable conductive composition to form conductive electrical circuits for capacitive switches and, in particular, in the thermoforming of the total construction.
DETAILED DESCRIPTION OF INVENTION
[0012] The invention relates to a polymer thick conductive composition for use in thermoforming electrical circuits and, in particular, capacitive switch circuits. A layer of conductor is printed and dried on a substrate so as to produce a functioning circuit and then the entire circuit is subjected to pressure and heat that deforms the circuit to its desired three dimensional characteristics, i.e., thermoforming.
[0013] The substrates commonly used in polymer thick film thermoformed circuits are polycarbonate (PC), PVC and others. PC is generally preferred since it can be thermoformed at higher temperatures. However, PC is very sensitive to the solvents used in the layers deposited on it.
[0014] The polymer thick film (PTF) conductive composition is comprised of (i) silver, (ii) a first organic medium comprising a first polymer resin dissolved in a first organic solvent and (iii) a second organic medium containing a second polymer resin dissolved in a second organic solvent.
[0015] In an embodiment that results in no crazing or deformation of the underlying substrate onto which the PTF conductive composition is printed, the PTF conductive composition further comprises a third solvent, diacetone alcohol.
[0016] Additionally, powders and printing aids may be added to improve the composition.
[0017] Each constituent of the electrically conductive composition of the present invention is discussed in detail below.
[0018] A. Conductive Silver Powder
[0019] The silver in the present thick film composition are Ag conductor powders and may comprise Ag metal powder, alloys of Ag metal powder, or mixtures thereof. Various particle diameters and shapes of the metal powder are contemplated. In an embodiment, the conductive powder may include any shape silver powder, including spherical particles, flakes (rods, cones, plates), and mixtures thereof. In one embodiment, the silver is in the form of silver flakes.
[0020] In an embodiment, the particle size distribution of the silver powders is 1 to 100 microns; in a further embodiment, 2-10 microns.
[0021] In an embodiment, the surface area/weight ratio of the silver particles is in the range of 0.1-1.0 m 2 /g.
[0022] Furthermore, it is known that small amounts of other metals may be added to silver conductor compositions to improve the properties of the conductor. Some examples of such metals include: gold, silver, copper, nickel, aluminum, platinum, palladium, molybdenum, tungsten, tantalum, tin, indium, lanthanum, gadolinium, boron, ruthenium, cobalt, titanium, yttrium, europium, gallium, sulfur, zinc, silicon, magnesium, barium, cerium, strontium, lead, antimony, conductive carbon, and combinations thereof and others common in the art of thick film compositions. The additional metal(s) may comprise up to about 1.0 percent by weight of the total composition.
[0023] In one embodiment, the silver flakes are present at 30 to 70 wt %, based on the total weight of the PTF conductive composition. In another embodiment, the silver flakes are present at 40 to 70 wt % and in still another embodiment, the silver flakes are present at 48 to 58 wt %, again based on the total weight of the PTF conductive composition.
[0024] B. Organic Media
[0025] The first organic medium is comprised of a thermoplastic urethane resin dissolved in a first organic solvent. The urethane resin must achieve good adhesion to the underlying substrate. It must be compatible with and not adversely affect the performance of the circuit after thermoforming. In one embodiment the thermoplastic urethane resin is 10-50 wt % of the total weight of the first organic medium. In another embodiment the thermoplastic urethane resin is 15-45 wt % of the total weight of the first organic medium and in still another embodiment the thermoplastic urethane resin is 15-25 wt % of the total weight of the first organic medium. In one embodiment the thermoplastic urethane resin is a urethane homopolymer. In another embodiment the thermoplastic urethane resin is a polyester-based copolymer.
[0026] The second organic medium is comprised of a thermoplastic polyhydroxyether resin dissolved in a second organic solvent. It should be noted that the same solvent that is used in the first organic medium can be used in the second organic medium or a different solvent could be used. The solvent must be compatible with and not adversely affect the performance of the circuit after thermoforming. In one embodiment the thermoplastic polyhydroxyether resin is 10-50 wt % of the total weight of the second organic medium. In another embodiment the thermoplastic polyhydroxyether resin is 15-45 wt % of the total weight of the second organic medium and in still another embodiment the thermoplastic resin is 20-30 wt % of the total weight of the second organic medium.
[0027] The polymer resin is typically added to the organic solvent by mechanical mixing to form the medium. Solvents suitable for use in the organic media of the polymer thick film conductive composition are recognized by one of skill in the art and include acetates and terpenes such as carbitol acetate and alpha- or beta-terpineol or mixtures thereof with other solvents such as kerosene, dibutylphthalate, butyl carbitol, butyl carbitol acetate, hexylene glycol and high boiling alcohols and alcohol esters. In addition, volatile liquids for promoting rapid hardening after application on the substrate may be included. In many embodiments of the present invention, solvents such as glycol ethers, ketones, esters and other solvents of like boiling points (in the range of 180° C. to 250° C.), and mixtures thereof may be used. Various combinations of these and other solvents are formulated to obtain the viscosity and volatility requirements desired. The solvents used must solubilize the resin.
[0028] Third Organic Solvent
[0029] In one embodiment , the conductive composition further comprises a third organic solvent, diacetone alcohol. In an embodiment the diacetone alcohol is 1-20 wt % of the total weight of the PTF conductive composition. In another embodiment the diacetone alcohol is 3-12 wt % of the total weight of the PTF conductive composition and in still another embodiment the diacetone alcohol is 4-6 wt % of the total weight of the PTF conductive composition.
[0030] Additional Powders
[0031] Various powders may be added to the PTF conductor composition to improve adhesion, modify the rheology and increase the low shear viscosity thereby improving the printability.
[0032] Application of the PFT Conductor Composition
[0033] The PTF conductor, also referred to as a “paste”, is typically deposited on a substrate, such as polycarbonate, that is impermeable to gases and moisture. The substrate can also be a sheet of a composite material made up of a combination of plastic sheet with optional metallic or dielectric layers deposited thereupon.
[0034] The deposition of the PTF conductor composition is performed typically by screen printing, but other deposition techniques such as stencil printing, syringe dispensing or coating techniques can be utilized. In the case of screen-printing, the screen mesh size controls the thickness of the deposited thick film.
[0035] Generally, a thick film composition comprises a functional phase that imparts appropriate electrically functional properties to the composition. The functional phase comprises electrically functional powders dispersed in an organic medium that acts as a carrier for the functional phase. Generally, the composition is fired to burn out both the polymer and the solvent of the organic medium and to impart the electrically functional properties. However, in the case of a polymer thick film, the polymer portion of the organic medium remains as an integral part of the composition after drying.
[0036] The PTF conductor composition is processed for a time and at a temperature necessary to remove all solvent. For example, the deposited thick film is dried by exposure to heat at 140° C. for typically 10-15 min.
[0037] Circuit Construction
[0038] The base substrate used is typically 10 mil thick polycarbonate. The conductor composition is printed and dried as per the conditions described above. Several layers can be printed and dried. Subsequent steps which may include thermoforming (190° C., 750 psi) of the entire unit is typical in the production of 3D capacitive switch circuits.
EXAMPLES, COMPARATIVE EXPERIMENTS
Example 1
[0039] The PTF conductor composition was prepared in the following manner. 20.50 wt % of the first organic medium was used and was prepared by mixing 20.0 wt % Desmocoll 540 polyurethane (Bayer MaterialScience LLC, Pittsburgh, Pa.) with 80.0 wt % dibasic esters (obtained from DuPont Co., Wilmington, Del.) organic solvent. The molecular weight of the resin was approximately 20,000. This mixture was heated at 90° C. for 1-2 hours to dissolve all the resin. 53.75 wt % of a flake silver powder with an average particle size of approximately 5 microns was added to the first organic medium. A printing additive (0.25 wt %) was also added. Finally, 25.5 wt % of a second organic medium was prepared by mixing and heating as described above 27.0% of polyhydroxyether resin PKHH (Phenoxy Associates, Rock Hill, S.C.) with 73.0% dibasic esters (obtained from DuPont Co., Wilmington, Del.) and then was added to the first organic medium, flake silver powder and printing additive mixture. The wt % of the first organic medium, the flake silver powder, the printing additive and the second organic medium were based upon the total weight of the composition.
[0040] This composition was mixed for 30 minutes on a planetary mixer, and then subjected to several passes on the three roll-mill.
[0041] A circuit was then fabricated as follows. On a 10 mil thick polycarbonate substrate, a pattern of a series of interdigitated silver lines were printed using a 280 mesh stainless steel screen. The patterned lines were dried at 120° C. for 15 min in a forced air box oven. The part was inspected and minimal crazing or deformation of the underlying substrate was found. After thermoforming at 190° C., the conductive lines remained conductive and were well adhered to the substrate.
Comparative Experiment 1
[0042] A circuit was produced exactly as described in Example 1. The only difference was that the second organic medium was not used. Inspection of the substrate showed that the silver composition showed minimal crazing and deformation of the underlying polycarbonate substrate. The conductive traces remained conductive after thermoforming as well although the overall quality of the traces was somewhat reduced.
Comparative Experiment 2
[0043] A circuit was produced exactly as described in Example 1. The only difference was that the conductive composition used contained 63.0 wt % silver flake and a polyester resin in place of the urethane and polyhydroxyether resins. After thermoforming, the conductor lines were no longer conductive and did not adhere well to the substrate.
Example 2
[0044] A circuit was produced exactly as described in Example 1. The only difference was that 5 wt % of diacetone alcohol was added to the conductive composition of claim 1 .
[0045] Inspection of the substrate showed that the silver composition showed no crazing or deformation of the underlying polycarbonate substrate. A definite improvement from Comparative Experiments 1 and 2 could be seen. There was also improvement over the minimal crazing or deformation of the underlying substrate found in Example 1.
[0046] The use of the urethane and polyhydroxyether resins clearly show strikingly good results after thermoforming. Replacement with a different resin type i.e., polyester, renders the composition non-conductive after thermoforming. The additional improvement in resistance to crazing as a result of the presence of diacetone alcohol solvent is also apparent from the results shown above in Example 2. | This invention is directed to a polymer thick film conductive composition. More specifically, the polymer thick film conductive composition may be used in applications where thermoforming of the base substrate occurs as in capacitive switches. Polycarbonate substrates are often used as the substrate and the silver conductor composition may be used without any barrier layer. | 7 |
This application is a divisional of U.S. application Ser. No. 10/618,331, filed Jul. 11, 2003 now U.S. Pat. No. 7,354,569. The disclosures of the above application are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a chewable confectionery composition which reduces the presence of dental plaque from the chewing surfaces of teeth and more particularly the invention relates to a chewable confectionery composition which contains a small but effective amount of a an enzyme effective to disrupt or interfere with plaque formation and adhesion to tooth surfaces.
2. Prior Art
Oral compositions such as toothpastes, gels and mouth washes are designed to loosen and remove plaque in conjunction with a regular toothbrushing regimen. Dental plaque is present to some degree, in the form of a film, on virtually all dental surfaces. It is a byproduct of microbial growth, and comprises a dense microbial layer consisting of a mass of microorganisms embedded in a polysaccharide matrix. Plaque itself adheres firmly to dental surfaces and is removed only with difficulty even through a rigorous brushing regimen. Moreover, plaque rapidly reforms on the tooth surface after it is removed. Plaque may form on any part of the tooth surface, and is found particularly at the gingival margin, in cracks in the enamel and on the surface of dental calculus. The problem associated with the formation of plaque on the teeth lies in the tendency of plaque to build up and eventually produce gingivitis, periodontitis and other types of periodontal disease, as well as dental caries and dental calculus.
Plaque formation is an ongoing process. Although various oral care products are available to control plaque formation such as toothpastes and mouth rinse, the disadvantage of these products is that only a relatively short time during which the teeth are being brushed or the mouth is being rinsed is available for these preparations to take effect. A further disadvantage of these toothpaste and mouth rinse products is the general infrequency of use, that is, most dental hygiene products are used once or perhaps twice daily and seldom when they are most needed, e.g., after meals and snacks. Thus food deposits which build up as a result of eating throughout the day are left in the oral cavity for long periods of time thereby promoting microbial growth and formation of plaque on tooth surfaces.
It is known to the art to incorporate antimicrobial agents in oral compositions wherein these agents destroy or inhibit oral bacteria responsible for plaque formation. Other agents are also incorporated in the oral composition to reduce plaque formation on teeth. For example, it is known to incorporate enzymes such as proteases and carbohydrases in oral compositions, which enzymes disrupt or interfere with plaque formation and bacterial adhesion to tooth surfaces.
Chewable tablets and gums have been used as vehicles for introducing various chemical agents to tooth surfaces including enzymes such as amylase enzymes (U.S. Pat. No. 4,740,368) oxidoreductases such as glucose oxidase and lactoperoxidase enzymes (U.S. Pat. No. 4,564,519).
A critical requirement, however, for these compositions is that they are stable and have a long shelf-life, which requirement has limited the use of these compositions because normally, the active agents incorporated in these compositions that provide oral care benefits such as plaque reduction are not stable under ambient conditions of humidity and temperature and as a result the agents quickly become degraded to concentrations of limited efficacy and particularly, enzymes which denature during the manufacturing process.
In view of the inconvenience of using toothpaste and mouth rinse products when away from home, the art is seeking portable products in the form of chewable confections such as tablets and gums which can be used throughout the day, particularly after eating, and which provide antiplaque benefits comparable to those obtained by regular brushing with a toothpaste or use of a mouthrinse.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a chewable confectionery composition such as a chewable tablet or gum comprised of a small but effective amount of a plaque reducing enzyme, a non-cariogenic sweetener and optionally a plasticizing/softening agent.
Due to the inherent nature of the chewable tablet or gum product, prolonged contact with the tooth surfaces is achieved when the product is chewed, forming a paste with saliva containing the enzyme which coats the tooth surfaces. The delivery of the enzyme in a chewable tablet or gum form insures that an adequate dosage of the antiplaque enzyme is deliverable when the product is chewed by the user. The chewable confectionery composition of the present invention is portable and can be packaged and stored in a consumers pocket or purse for consumption anytime and anywhere.
When the chewable confectionery composition of the present invention is placed within the mouth and chewed, an effective antiplaque amount of the enzyme is released from the composition into the saliva where it can reach the surface of the teeth to prevent further plaque accumulation. The tablet or gum of the present invention is formed so as to release the enzyme over a period of 0.5 to 2 minutes. Consistent daily use of the chewable tablets or gums of the present invention will then obtain maximum plaque reduction from the teeth of the consumer.
The term “chewable confectionery composition” as used herein includes within its meaning chewing gum, and chewable and orally soluble tablets, troches and lozenges.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The composition of the present invention as stated is a chewable product which reduces plaque and contains as the active ingredient, a protease enzyme. The product is preferably sugarless.
A representative chewable antiplaque tablet in accordance with the practice of this invention contains about 0.1 to 3% by weight of an enzyme, 0.5 to 5% by weight of a combination plasticizing/softening ingredient and about 50 to about 90% by weight of a non-cariogenic sweetener. In addition to the ingredients discussed above for tablets, chewable gum compositions will contain 10 to 40% by weight of a gum base.
As water promotes the denaturization of the papain enzyme, the presence of water in the chewable confectionery product of the present invention should be at relatively low concentrations in order to impart maximum stability and shelf life to the chewable. For this purpose, it has been found essential to limit the total amount of water present in the chewable product to no more than 5% by weight.
Enzymes
The enzymes useful in the practice of the present invention include carbohydrases such as glucoamylase and enzymes extracted from natural fruit products such as proteases which breakdown or hydrolyze proteins.
Protease enzymes useful in the practice of the present invention include those extracted from natural fruit products. The proteolytic enzymes are obtained from natural sources or by the action of microorganisms having a nitrogen source and a carbon source. Examples of proteolytic enzymes useful in the practice of the present invention include the naturally occurring enzymes papain (from papaya), bromelain (from pineapple), as well as serine proteases such as chymotrypsin. Additional enzymes include ficin and alcalase. Papain is a protease enzyme preferred for use in the practice of the present invention, the papain having an activity of 150 to 939 MCU per milligram as determined by the Milk Clot Assay Test of the Biddle Sawyer Group (see J. Biol. Chem., vol. 121, pages 737-745). The protease enzymes are included in the compositions of the present invention at a concentration of about 0.1 to about 3% by weight and preferably about 0.2 to about 2% by weight.
Enzymes which may beneficially be used in combination with the proteolytic enzymes and glucoamylase enzymes include carbohydrases such as glucoamylase, alpha-amylase, beta-amylase, tannase and lipases such as plant lipase, gastric lipase and pancreatic lipase.
Glucoamylase is a saccharifying glucoamylase of Aspergillus niger origin cultivated by fermentation. This enzyme can hydrolyze both the alpha-D-1,6 glucosidic branch points and the alpha-1,4 glucosidic bonds of glucosyl oligosaccharides. Additional carbohydrases useful in accordance with this invention are alpha and beta-amylase, dextrinase and mutanase. Glucoamylase is a preferred enzyme and is incorporated in the oral composition of the present invention at a concentration of about 0.001 to 2% by weight and preferably about 0.01 to 0.55% by weight.
The lipase enzyme is derived from a select strain of Aspergillus niger , exhibiting random cleaving of the 1,3 positions of fats and oils. The enzyme has maximum lipolytic activity at pH 5.0 to 7.0 when assayed with olive oil. The enzyme has a measured activity of 120,000 lipase units per gram. The lipase may be included in the dentifrice composition at a concentration of about 0.010 to about 5.0% by weight and preferably about 0.02 to about 0.01% by weight.
The presence of tannase enzyme can be further beneficial in facilitating the breakdown of extrinsic stain. Tannase enzymes have been purified from Aspergillus niger and Aspergillus allianceus and are useful in the hydrolysis of tannins, known to discolor the tooth surface.
Other suitable enzymes which can comprise the present invention include lysozyme, derived from egg white, which contains a single polypeptide chain crosslinked by four disulfide bonds having a molecular weight of 14,600 daltons. The enzyme can exhibit antibacterial properties by facilitating the hydrolysis of bacterial cell walls cleaving the glycosidic bond between carbon number 1 of N-acetylmuramic acid and carbon number 4 of N-acetyl-D-glucosamine, which in vivo, these two carbohydrates are polymerized to form the cell wall polysaccharide. Additionally, pectinase, an enzyme that is present in most plants facilitates the hydrolysis of the polysaccharide pectin into sugars and galacturonic acid. Finally, glucanase, which may be utilized to catalyze the breakdown of complex carbohydrates to glucans and the hydrolysis of beta glucan to glucose.
Enzyme Stabilizing Agents
Enzyme stabilizing agents which protect the enzyme from inactivation by chelating metal impurities present in the chewable confectionery composition of the present invention may be incorporated in the composition include ethylene diamine tetraacetic acid (EDTA) and sodium gluconate at concentrations between 0.01 and 1% by weight, preferably between 0.1 and 0.5% by weight. Agents stabilizing the enzyme against oxidation include reducing agents such as sodium bisulfite, metal gallates, potassium stannate, sodium stannate, ammonium sulfate, 3,5,-di-tert-butyl-4-hydroxytoluene (BHT), Vitamin E (α, β, γ, forms)/Vitamin E acetate and ascorbic acid. Potassium stannate is an enzyme stabilizing agent preferred for use in the practice of the present invention. The reducing agent is present in the oral composition of the present invention at a concentration between about 0.05 to about 1.5% by weight, preferably between about 0.1 and about 0.75% by weight.
Tablets
Plasticizing/Softening Agents
Plasticizing/softening agents suitable for use in the preparation of tablets in accordance with the practice of this invention, include propylene glycol, glycerol, acetylated monoglyceride, glyceryl triacetate, glyceryl diacetate, lecithin, glycerin, and mixtures thereof. In a preferred embodiment of this invention, a combination of lecithin and glycerin is used, generally in amounts of about 0.5% to about 3.0% by weight, 0.1% to about 1.0% lecithin and about 1.0% to about 1.0% by weight glycerin by weight, based on the weight of the total chewable tablet composition.
Sweeteners
The sweetening agent ingredient used in the practice of the present invention include bulk sweeteners such as the polyols of 5 to 12 carbon atoms substituted with 5 to 9 hydroxyl groups such as sugar alcohols including xylitol, sorbitol, mannitol, Sugar alcohols provide bulk or texture to the chewable compositions of the present invention and are utilized in amounts of about 25% to about 90% by weight preferably about 40% to about 85% by weight
Artificial sweeteners include as sodium or calcium saccharin salts, cyclamate salts, such as the sodium salt and the like, and the free acid form of saccharin; dipeptide based sweetening agents such as L-aspartyl-L-phenyl-alanine methyl ester, dihydrochalcone: glycyrrhizin; and the synthetic sweetener 3,6-dihydro-6-methyl-1, 1,2,3-oxathiazine-4-one-2,2-dioxide, particularly the potassium (Acesulframe-K), sodium and calcium salts. Artificial sweeteners are present in the chewable confectionery compositions of the present invention at a concentration of about 0.1 to about 1% by weight.
Preferred bulk sweeteners include Lycasin, a commercially available mixture of sorbitol, malitol and high molecular weight dextrans disclosed in Re 26,969 and Isomalt, a sugar alcohol of a disaccharide such as alpha-D-glucopyranosyl-1,6-mannitol, its isomer, alpha, D-glucopyranosyl-1,6-sorbitol or a mixture thereof which is obtained by the hydrogenation of palatinose which is converted from sucrose as a raw material with glycosyltransferase. A preferred artificial sweetener is aspartame.
In a preferred embodiment of this invention, the sweetening agent used is a combination of an artificial sweetener such as aspartame and acesulfame and the bulk sweeteners such as Lycasin and Isomalt, the artificial sweetener being present generally in amounts of about 0.05% to about 0.3% by weight and preferably about 0.18% to about 0.22% by weight and about 40% to about 60% by weight, preferably about 45% to about 55% by weight Lycasin and about 15% to about 35(% by weight preferably about 20% to about 30% by weight Isomalt.
Flavoring Agents
One or more flavoring agents in liquid powder or encapsulated form are used in the chewable composition of this invention. A variety of flavors known in the art may be used, including essential oils, such as cinnamon, spearmint, peppermint, menthol, birch, anise wintergreen oil and eucalyptus oil. Natural fruit flavors derived from the essence of fruits, such as apple, pear, peach, strawberry, cherry, apricot, orange, watermelon, banana and the like; bean derived flavors such as coffee, cocoa and the like; wine derived curacao zin and the like, and pungent materials, such as affinin, pepper, mustard and the like. Flavoring agents are incorporated in the chewable confectionery compositions at a concentration of about 0.5 to about 5% by weight and preferably about 1.0 to about 3.0% by weight.
Other Ingredients
Calcium salts may be incorporated in the chewable compositions of the resent invention as fillers and anticavity agents. Examples of the calcium salts to be used in the present invention as the anticaries agent are, for example, calcium chloride, calcium nitrate, calcium sulfate, dicalcium phosphate dihydrate, calcium carbonate, calcium citrate, calcium hydrogen pyrophosphate, calcium gluconate, calcium glycerophosphate, calcium hydroxide, calcium oxide, calcium silicate and the like, but not limited thereto. The calcium salt is present in the tablet or gum at a concentration of about 5 to about 20% by weight and preferably 7 to 10% by weight. Alkaline agents such as sodium bicarbonate may be incorporated in the chewable confectionery composition of the present invention to provide additional cleaning and breath freshening properties to the composition.
Chewing Gum
The chewing gum of the present invention is preferably a sugarless chewing gum containing the enzyme, as sugarless gums do not promote tooth decay. Chewing gum formulations in which the enzymes of the present invention may be incorporated are well known in the art and typically contain, in addition to, a chewing gum base, one or more plasticizing agents; at least one sweetening agent and at least one flavoring agent.
Gum base materials suitable for use in the practice of this invention are well known in the art and include natural or synthetic gum bases or mixtures thereof. Representative natural gums or elastomers include chicle, natural rubber, jelutong, balata, guttapercha, lechi caspi, sorva, guttakay, crown gum, perillo, or mixtures thereof. Representative synthetic gums or elastomers include butadiene-styrene copolymers, polyisobutylene and isobutylene-isoprene copolymers.
The gum base is incorporated in the chewing gum product at a concentration of about 10 to about 40% by weight and preferably about 20 to about 35% by weight.
Plasticizing/softening agents commonly used in chewing gum compositions are suitable for use in this invention, including gelatin, waxes and mixtures thereof in amounts of 0.1 to 5% by weight.
The sweetening agent ingredient used in the practice of this invention may be selected from a wide range of materials. Bulk sweeteners include the same sweeteners used for the preparation of chewable tablets as are artificial sweeteners. The bulk sweetener is present in the chewing gum composition of the present invention in amounts of about 40 to about 80% by weight and preferably about 50 to about 75% by weight. The artificial sweetener is present in the chewing gum composition of the present invention in amounts of about 0.1 to about 2% by weight and preferably about 0.3 to 1% by weight.
In addition to the ingredients listed above, the gum compositions may also include conventional additives such as colorants, flavoring agents and the like. For example, titanium dioxide may be utilized as a colorant. A variety of flavors known in the art may be used, including essential oils, such as cinnamon, spearmint, peppermint, menthol, birch, anise and the like; natural fruit flavors derived from the essence of fruits, such as apple, pear, peach, strawberry, cherry, apricot, orange, watermelon, banana and the like; bean-derived flavors, such as coffee, cocoa and the like. Flavoring agents are incorporated in the chewing gum formulation at a concentration of about 0.5 to about 5% by weight and preferably 1 to 3% by weight.
Method of Manufacture
The challenge in incorporating enzymes into the confectionary composition is maintaining enzymatic stability and activity during storage. Enzymes are quaternary proteins whose structure, function, and stability are sensitive to chemical environment and processing parameters. Enzymes denature in harsh chemical environment and at high temperatures. Formulation and processing procedures are optimized at low moisture and low temperature for both the enzyme chewable tablet and the enzyme gum to preserve enzymatic activity and in vivo efficacy.
The chewable composition of the present invention is made by any suitable process where the protease enzyme is incorporated into the solid base material such that no water or a limited amount of ingredients that absorb water are used that would result in undesirable amounts of water being introduced into the composition during processing or storage. Further, at the time the enzyme is introduced into ingredients used to prepare the chewable composition that the temperature at the time of addition is less then about 80° C. Therefore, it is critical to the practice of the present invention that composition contain less than 5% by weight water and preferably less than 3% by weight water and that the temperature at which processing of the enzyme occurs be less than about 80° C. The presence in the composition of water in amounts greater than 5% by weight or the use of temperatures in excess of 80° C. will act to denature the protease enzyme thereby substantially reducing the efficacy of the enzyme in effecting plaque reduction on teeth.
One method for manufacturing the composition of the invention comprises first heating the base material to a temperature sufficient to drive off any water in the composition. The base material is then cooled to a temperature at which the enzyme and other temperature sensitive ingredients such as plasticizers, other sweeteners are incorporated and mixed into the base material.
Formulations, equipment and processing techniques have been well developed in the art for preparing and packaging chewing gum and chewable tablets and lozenges. As the enzyme is subject to deterioration and inactivation under conditions such as high shear and elevated temperatures, processing conditions are controlled during the time period that the enzymes are admixed with the other ingredients of the formulation and converted into finished products so that the temperature at the time of admixture does not exceed about 80° C. for any extended period of time.
The tablets of the confectionary composition of the present invention are conventionally made by grinding the ingredients once mixed and then compressing or molding the ingredients to form a suitable means for the delivery of the enzyme. In order to produce tablets it is necessary to have a free flowing material which has good self binding properties and which will not stick to the molding or compression equipment.
An illustrative procedure for formulating the chewing gum composition is as follows: the gum base is first melted in a heated kettle at 55″-65° C. One or more of the sweeteners are then added to the gum base followed by one or more flavors, plasticizer. All ingredients are then mixed for a sufficient period of time to ensure adequate dispersion. The mixture is then allowed to cool and the enzyme is added and is cut into suitable serving sizes.
In order to enhance shelf stability, in addition to the admixture used in the preparation of the chewable product being substantially free of water, the finished product should be packaged in a manner so as to minimize exposure to air and moisture.
The following Examples are illustrative of the present invention, but it is understood that the invention is not limited thereto.
EXAMPLE 1
Enzyme (papain) containing tablet and gum compositions were prepared using conventional base ingredients as set forth in Tables I and II below.
TABLE I
CHEWABLE TABLET
Ingredient
Wt. %
Papain
0.5
Lycasin 75%
48.9
Isomalt
23.1
Hydrogenated vegetable oil
8.7
Water
4.8
Gelatin (40% solution)
2.9
Starch coated dicalcium phosphate
8.7
Mono-diglyceride mixture
0.8
Lecithin
0.3
Aspartame
0.05
Aspartame K
0.05
Vanillin
0.05
Glycerin
0.1
Sodium bicarbonate
0.10
Mint flavor
0.19
The chewable tablet of Table I was prepared by boiling the Isomalt, Lycasin, water, fat, mono and diglyceride mixture, glycerin, and lecithin to 267-268° F. (131° C.) after which glycerin was added and the mixture and cooled to 140° F. (60° C.). Thereafter sodium bicarbonate, papain., dicalcium phosphate and the remaining ingredients were added. Thereafter the mixture cooled to room temperature 72-77° F. (23° C.) was ground into powder and compressed into a tablet using a tablet press.
TABLE II CHEWING GUM Ingredient Wt. % Gum base 31.20 Sorbitol 28.08 Mannitol 5.23 Papain 1.00 Acesulfame K 0.16 Aspartame 0.16 Menthol powder 1.00 Liquid flavor 0.47 Isomalt PF 11.70 Isomalt DC 16.00 Anticaking agents* 4.00 Flavor 2.00 *Magnesium stearate, talc, silica gel.
Papain Enzyme Activity
Papain activity was measured and monitored in the papain containing chewable tablets and chewing gums using the Protease Detection kit from Panvera Corp. The activity kit quantifies protease activity using a fluorescein thiocarbamoyl (FTC)-casein substrate. FTC-casein is attacked by the protease, breaking down casein into TC-peptides. The amount of protease activity is determined by measuring the fluorescence expressed as relative fluorescence units (RFU). The fluorescence signal generated is proportioned to the level of activity of papain in the tablet or gum delivery system. For the purposes of comparison, chewable tablets designated “Tablet A” and chewing gum designated “Chewing Gum B” were prepared in which papain was not included in these compositions. The papain activities of the chewable tablet or Table I and the chewing gum of Table II are recorded in Tables III and IV below as are the papain activities of comparative tablet and gum compositions.
TABLE III
Protease Activity
Chewable Tablet Fluorescence
Composition
4 Weeks (RFU)
8 Weeks (RFU)
Table I
29,000
30,000
A
2,000
2,000
TABLE IV
Chewing Gum Fluorescence
Composition
4 Weeks (RFU)
Table II
38,000
B
1,500
The results recorded in Tables III and IV indicate that the enzyme activity in papain when incorporated in a chewable tablet or gum is retained over at least a 4 week period.
In Vivo Plaque Reduction Efficacy
The chewable tablet of Table I was tested for plaque reduction at 2-and 5- hours after chewing by human volunteers using plaque grown in vivo in an intra-oral retainer on hydroxyapatite disks. Confocal microscopy was used to visualize and quantify the changes in plaque coverage and plaque ultrastructure. Plaque removal was also measured by conventional light microscopy by staining the plaque before and after treatment with crystal violet indicator and measuring the changes in color intensity. Image Pro Analysis Software was used to perform the image analysis and the quantitative measurements. The color intensity was measured and used to determine stain removal. The greater the intensity, the greater the cleaning efficacy. These results are shown in Table V below.
TABLE V
Chewable Tablet Plaque Reduction Efficacy
% Reduction
Average Cluster
Total Area
from
Area
% Reduc-
(Microns{circumflex over ( )}2)
Baseline
(Microns{circumflex over ( )}2)
tion
Baseline
8681
—
54.45
—
2 hours
3537
59
20.10
63
5 hours
2959
66
26.18
52
Confocal images were made of the plaque before treatment (baseline) and 2 and 5 hours after treating with the tablet. Qualitatively, images showed that there is less bacterial coverage 2 and 5 hours after treatment in comparison to baseline. Image analysis was used to quantify these observations. The results recorded in Table V indicated that the total plaque area, measured by pixel counting, was significantly reduced in comparison to baseline and 2 and 5 hours after treatment. Table V also shows that the average cluster area of the plaque bacteria was significantly reduced after treatment demonstrating the significant efficacy in reducing plaque without the aid of mechanical assistance.
In a second study, the plaque before and after staining with crystal violet was viewed by conventional light microscopy. Image analysis was used to determine the white intensity measured in pixels, the higher the pixel number, the whiter the stain. The results from this study are shown in Table VI. The disks stained at baseline were more intensely colored (blue) than the disks stained 2 hours after treatment with the papain containing chewable tablet. The disks were 47.3% whiter than baseline, indicating less staining and therefore, less plaque. Similar results were observed with the papain chewing gum of Table II as shown in Table VII below.
TABLE VI
Chewable Tablet Staining Removal (White Intensity)
Improvement
*
*
*
Average
from Baseline
Baseline
125
100
—
112.5
—
Treatment
240
200
200
213.3
47.3%
*Inventors: What are these units.
TABLE VII
Chewing Gum Plaque Reduction Efficacy
% Reduction
Average Cluster
Total Area
from
Area
% Reduc-
(Microns{circumflex over ( )}2)
Baseline
(Microns{circumflex over ( )}2)
tion
Baseline
47,832
—
2897
—
2 hours
38,137
16
2446
15
5 hours
27,267
52
1398
52 | A chewable confectionery dental composition delivering to the mouth a unit dose of a plaque reducing enzyme the composition comprising an enzyme and a non-cariogenic sweetener, the enzyme being incorporated in the composition at a temperature less than about 80° C. | 8 |
FIELD OF THE INVENTION
The present invention relates to semiconductor devices and methods of manufacture, and particularly, to complementary metal oxide semiconductor (CMOS) transistors with stress in the channels.
BACKGROUND OF THE INVENTION
Each new generation of semiconductor technology demands higher performance in semiconductor devices, particularly in the performance of CMOS transistors. One of the key metrics of transistor performance is the on-current of the transistor per unit width, typically measured in hundreds of microamperes per micron of the channel width, or “gate width” as it is commonly referred to. Various methods have been considered and practiced to enhance the on-current of the CMOS transistors, that is, both PFETs (transistors wherein the minority carriers are holes, which are p-type carriers), and NFETs (transistors wherein the minority carriers are electrons, which are n-type carriers). Among them, improving the mobility of minority carriers in the channel is the most common method of enhancing the on-current of the CMOS transistors. Some of these methods utilize inherent differences in the mobility of carriers along the different crystallographic orientations of the semiconductor crystal, while some others utilize the changes in the mobility of the carriers under stress in the plane of the channel.
In the case of the latter, wherein stress within the channel of a CMOS transistor is altered, a few different approaches exist. According to a first approach, the semiconductor lattice is implanted with atoms with similar electronic properties but with different lattice constants. All of silicon, germanium, and carbon have identical electronic outer shells and the same crystal structure, namely, “the diamond structure,” with their room temperature lattice constants of 0.5431 nm, 0.565 nm, and 0.357 nm, respectively. Substitution of some of the atoms in a crystal that are made up of one type of atoms with atoms of different species fabricates a crystal with an altered natural lattice constant from that of the original crystal. Natural lattice constant herein denotes the lattice constant of the material when no stress is applied externally. For the purposes of silicon based semiconductor devices, silicon crystals with a small percentage of carbon or germanium in substitutional sites are commonly used. When substitutional alloys of such materials are epitaxially disposed on a silicon substrate, stress is applied to the material since the alloy is now forced to have the same lattice constant as the underlying silicon instead of its own natural lattice constant. However, as demonstrated in FIG. 9 in Ernst et al., “Fabrication of a novel strained SiGe:C-channel planar 55 nm n-MOSFET for High-Performance CMOS,” VLSI Symp., 2002, pp. 92-93, the substitutional atoms in the alloy serve as scattering centers and actually degrade the mobility. Similar problems are encountered with substitutional alloys of silicon and germanium.
A second approach is to build the channel of a CMOS transistor on a silicon layer that is epitaxially deposited on a crystalline silicon alloy with an altered lattice constant different from that of silicon. Specifically, the silicon layer is constructed essentially with silicon, having a low level of electrical doping as necessary but does not contain a silicon carbon alloy or a silicon germanium alloy to avoid the problems of the first approach. However, the substrate itself has an altered lattice constant. For example, a smaller lattice constant compared with that of silicon is achieved by alloying silicon with a small percentage of carbon, e.g., between 0% and 10% in atomic concentration. In this alloy, the carbon atoms are placed substitutionally, that is, replacing the silicon atoms from the structure of the crystal, as opposed to interstitially, that is, by being placed between the sites that the original silicon atoms are still occupying. In another example, a larger lattice constant compared with that of silicon is achieved by alloying silicon with germanium, e.g. between 0% and 40% in atomic concentration. In the process of manufacturing these devices, a substrate with an altered lattice constant is formed first, followed by the formation of a strained silicon layer through epitaxial deposition of silicon. Cheng et al., “Electron Mobility Enhancement in Strained-Si n-MOSFETs Fabricated on SiGe-on Insulator (SGOI) Substrates,” IEEE Electron Device Letters, Vol. 22, No. 7, July 2001 demonstrates an example of such an approach with improvement in the performance of PFETs.
While the second approach does produce devices with improved performance, such an approach faces some challenges in that the formation of a crystalline structure with an altered lattice parameter generally depends on the structural relaxation of the epitaxially grown alloy material, be it an alloy of silicon and germanium or an alloy of silicon and carbon, through the generation of misfit dislocations, which are crystalline defects in thick films. When the film is thin, the epitaxial alignment of the alloy to the underlying silicon substrate is preserved, therefore keeping the lattice constant in the plane of the epitaxial growth exactly the same as the underlying silicon substrate. Only when the alloy becomes thicker does the alloy relax and its lattice constant approaches the natural value for the alloy. Typically, the thickness required for full relaxation and reduction of the crystalline defects in the alloy to an acceptable level is on the order of 1,000 nm. Methods of improving the film quality is also known in the prior art.
As far as the performance of the CMOS transistors built with silicon channels are concerned, NFETs and PFETs require the opposite kind of stress. Specifically, the hole mobility is enhanced in a PFET when a compressive stress is applied to the channel along the direction of the movement of the holes, that is, in the direction of a line connecting the source and the drain. However, the electron mobility is enhanced in an NPFET when a tensile stress is applied to the channel along the direction of the movement of the electrons. Manufacturing both PFETs and NFETs with enhanced mobility through stress engineering on the same substrate, therefore, creates a challenge in that two types of substrate areas with an altered lattice parameter need to be fabricated. Such methods have been disclosed in the prior art, for example, in the U.S. patent application Publication No. US2005/0104131 A1 and in the U.S. patent application Publication No. US2005/0130358 A1. However, the general complexity of such processes still remains a challenge.
A third type of approach produces stress in the channel region by embedding an epitaxial alloy of silicon and carbon or, of silicon and germanium, within the source and the drain region of a transistor. Hence, they are called embedded epitaxial alloys. The most common choice of material includes an epitaxial silicon germanium alloy and epitaxial silicon carbon alloy (Si:C) on silicon substrates. According to this approach, the vertical dimensions of the alloy material in the source and the drain are much less than what is required for the alloy to generate misfit locations and relax. So the alloy material within the source and the drain maintains epitaxial alignment with the underlying silicon substrate. The lattice constant in the plane of the epitaxial alignment, which is the same as the plane in which the channel is located, remains identical to the lattice constant of the underlying silicon substrate. Since the alloy in the source and the drain has a different lattice constant than the natural lattice constant of the alloy, stress is exerted on the alloy itself and the alloy in turn exerts stress on the surrounding structures. The channel of the transistor located between a source and the drain is consequently stressed.
As noted above, the desired type of stress is different between NFET channels and PFET channels. For PFETs, the desired stress is a compressive stress along the direction of the line connecting the source and the drain. An epitaxial alloy of silicon and germanium in the source and the drain exerts such uniaxial stress on the channel. Ghani et al., “A 90 nm high Volume manufacturing Logic Technology Featuring Novel 45 nm Gate Length Strained Silicon CMOS Transistors,” Proc. IEDM , pp. 978-980, 2003 reported a successful implementation of this technology for the improvement of PFET performance. Likewise, NFETs require a tensile stress along the direction of the line connecting the source and the drain. An epitaxial alloy of silicon and carbon in the source and drain exerts such stress on the channel. Ang et al., “Thin Body Silicon-on-insulator N-MOSFET with Silicon-Carbon Source and drain regions for Performance Enhancement,” IEEE International Electron Device Meeting 2005, December 2005, pp. 503-506 reported improved NFET performance through the use of this technology.
As in the case of the second approach discussed above, a successful implementation of both PFETs and NFETs with enhanced mobility through stress engineering on the same silicon substrate requires a complex integration of processing steps. The U.S. patent application Publication No. US 2005/0082616 A1 discloses methods and structures of implementing particular versions of the PFETs and NFETs with enhanced mobility through stress engineering. In summary, for each type of CMOS transistors, the source and the drain regions of the transistors are etched and silicon alloys are epitaxially grown within the etched region. The masking of one type of transistors and etching of the other type of transistors are performed sequentially. Also, the silicon alloy material for each type of transistors is selected appropriately so that the stress exerted on the channel of the transistors enhances the mobility of the minority carriers in the channel.
During the research leading to the present invention, some problems in the manufacturing of enhanced mobility transistors as disclosed in Cheng et al., have been discovered. The first problem is a degradation of contact resistance on SiGe alloy. As the content of germanium increases, the contact resistance to the source and drain also tends to increase and degrade the performance of PFETs with embedded SiGe alloy in the source and the drain. This is because the alloy of metal silicide and metal germanide, which is formed by depositing a metal on the source and drain containing silicon and germanium and annealing the structure during the contact formation process, has inferior contact resistance to unalloyed metal silicide, that is, a metal silicide without any metal germanide mixed within. An example of an agglomeration triggered increase in the sheet resistance of the alloy of silicide and germanide was reported in Pey et al., “Thermal Reaction of nickel and Si 0.75 Ge 0.25 alloy,” J. Vac. Sci. Technol. A 20(6), November/December 2002, pp. 1903-1910, after an anneal above 700° C. in the alloy of nickel and Si 0.75 Ge 0.25 .
It has also been discovered during the course of research leading to the present invention that selective epitaxial growth of Si:C alloy produces a very rough surface with multiple facets. Metal silicides formed upon such surfaces have degraded performance compared to normal silicide formed on flat surface containing no carbon. Whatever the mechanism for this degradation may be, the selective Si:C epitaxial growth process currently available in the industry produces Si:C alloy surfaces which produces inferior silicide with higher contact resistance compared to a flat silicon surface containing no carbon.
Furthermore, it has been discovered that not only the reaction rate of the Si:C selective epitaxy process is very slow, but there is also a limit on the thickness of the Si:C films that can be grown by selective epitaxy process currently available in the industry. Apparently, the incorporation of carbon into silicon changes some of the reaction mechanism of conventional silicon epitaxy causing the thickness of the epitaxially grown Si:C film saturates in time. This means that the increase in the height of the source and the drain through the use of Si:C selective epitaxy has a limit, and that Si:C selective epitaxy is not conducive to manufacturing of NFET structures with highly raised source and drain relative to the height of the gate dielectric.
Therefore, there exists a need for a semiconductor structure and methods that produce stable and low contact resistance on SiGe alloy surfaces.
There exists another need for a semiconductor structure and methods that produce stable and low contact resistance on Si:C alloy surfaces.
Also, there exists a need for a semiconductor structure and methods that produce a thick epitaxial silicon alloy, especially a thick epitaxial Si:C alloy, above the level of the gate dielectric.
Finally, there exists a need for a semiconductor structure and methods that provide stable low resistance contacts for both mobility enhanced PFETs with embedded SiGe and mobility enhanced NFETs with embedded Si:C on the same semiconductor substrate.
SUMMARY OF THE INVENTION
The present invention addresses the needs describe above by providing structures and methods for providing stable and low contact resistance on SiGe alloy surfaces and Si:C alloy surfaces.
Specifically, the present invention addresses the needs described above by providing an epitaxially grown silicon layer on top of the epitaxially grown silicon alloys, be it a silicon germanium alloy for PFETs or an Si:C alloy for NFETs, embedded in the source and drain regions of the transistors. The epitaxially grown silicon layer, which is essentially free of germanium or carbon, produces an unalloyed silicide that does not contain any metal germanide or metal carbide.
The present invention also enables manufacture of a thick epitaxial silicon alloy, especially a thick epitaxial Si:C alloy, above the level of the gate dielectric.
Furthermore, the present invention provides semiconductor structures and methods for providing stable low contact resistance while providing mobility enhancement for both types of transistors on the same substrate.
While the present invention is described with a silicon on insulator (SOI) substrate, it should be recognized that the present invention can equally well be practiced on a bulk substrate, a silicon substrate with a thick deposited and relaxed layer of material as an Si 1-x Ge x layer, an Si 1-x C x layer, or an Si 1-x-y Ge x C y layer on the top of the substrate with some modifications. In most cases, the adjustment involves increasing or decreasing either the carbon content or germanium content during the formation of epitaxially grown sources and drains. In limiting cases where either the carbon concentration or germanium concentration approaches zero, and where either the silicon carbon alloy is replaced by pure silicon or the silicon germanium alloy is replaced by pure silicon, the present invention is also applicable as long as there is one silicon alloy present in at least one part of the sources and drains of either type of FETs.
The currently prevalent contact formation method in the semiconductor industry utilizes a blanket deposition of metal, such as nickel, nickel platinum alloy, cobalt, tantalum, tungsten, molybdenum, and titanium. This is followed by at least one thermal anneal process to facilitate the reaction of the deposited metal with the semiconductor material, including that in the source region and drain region of transistors. The prior art on the formation of carrier mobility enhanced transistors through stress engineering provides a silicon germanium alloy or silicon carbon alloy that is embedded in the source region and the drain region of transistors. According to the prior art, the metal that is deposited over the source region and the drain region for the formation of contacts reacts with the silicon germanium alloy or the silicon carbon alloy.
The interaction of the silicon alloy with the metal alters the composition of the material in the contact due to the introduction of other semiconductor material than silicon, such as carbon or germanium. When a silicon carbon alloy interacts with metal, the presence of carbon interferes with the silicide formation process. The resulting material after reaction is a mixture of metal silicide and metal carbide, metal silicide and carbon, or metal silicide, carbon, and metal carbide. The presence of other material than metal silicide and the resulting reduction in the grain size of the metal silicide contribute to the reduction in the conductivity, that is, the increase in the resistivity, of the contact material. In the case of a silicon germanium alloy, the presence of germanium results in the introduction of metal germanide into the contact material. As in the case of silicon carbon alloy, the mixture of metal silicide and metal germanide results in the reduction in the conductivity of the contact material.
The needs stated above are addressed by the methods and structures of the present invention which includes providing a silicon material onto the surface of the source and drain region before the formation of silicide.
According to a first group of embodiments in the present invention, a silicon germanium alloy and a silicon carbon alloy are first formed within the source and drain regions of transistors. Preferably, epitaxial silicon germanium alloy is embedded into the PFETs and epitaxial silicon carbon alloy is embedded into the NFETs. In general, the incorporation of the silicon germanium alloy material precedes the incorporation of silicon carbon alloy material into the silicon substrate. Preferably, the epitaxial silicon germanium alloy has a content of germanium that is greater than 0% and less than 40%. The third through sixth embodiments of the present invention in the first group, however, do allow the reversal of this order as will be described herein below.
The incorporation of the carbon into the silicon material to form an epitaxial silicon carbon alloy may be performed through conventional selective epitaxy of silicon with carbon doping as described in Cheng et al., or alternatively, performed by carbon implantation followed by an anneal. The latter is preferred for the ease and simplicity of the process methods. In both cases, the area over which the formation of silicon carbon alloy is not desired is masked to prevent unwanted silicon carbide alloys. After a carbon implantation process, the carbon atoms are incorporated into the existing crystalline structure as they move into substitutional sites during an anneal to form an Si:C alloy. Preferably, the epitaxial silicon carbon alloy has a content of carbon that is greater than 0% and less than 10% to help ensure the epitaxial structure of the alloy. Also, preferably, the anneal process for the incorporation of the carbon into the substitutional sites is a laser anneal with a peak temperature between 700° C. and 1428° C.
After the embedded silicon carbon alloy and the embedded silicon germanium alloy are introduced into the structures of the transistors, a silicon material that is essentially free of carbon or germanium is deposited by a selective silicon deposition process over the silicon alloys, including those in the source region and the drain region. Preferably, the selective silicon deposition process is a selective silicon epitaxy due to the advantageous nature of the epitaxial alignment of the new silicon material to the underlying crystal structure. The present invention is therefore described utilizing selective silicon epitaxy. However, alternative silicon deposition processes that are not a selective silicon epitaxy are also contemplated herein.
The doping of the source and drain for both PFETs and NFETs may be performed at any point after formation of the embedded silicon germanium alloy and before deposition of metal for the sake of contact formation. This point is further illustrated below in the Detailed
SUMMARY OF THE INVENTION
Metal is thereafter deposited on the surfaces of the source and drain regions of both PFETs and NFETs. All of these surfaces now contain silicon material, whether doped with conventional electrical dopants such as boron, antimony, phosphorus, and arsenic or undoped as pure silicon material. The silicon material in the source and drain regions must be contrasted with any silicon alloy material in the prior art, such as silicon carbon alloy or silicon germanium alloy, whether doped with conventional electrical dopants or not. Prior art provides silicon alloy surfaces for contact formation on transistors with embedded silicon germanium alloy in the source and drain regions. According to the first group of embodiments of the present invention, all semiconductor surfaces that come into contact with the deposited metal for the sake of contact formation contain essentially no carbon or germanium.
According to the first group of embodiments of the present invention, the newly formed silicon layer produces pure metal silicide during the contact formation process. This metal silicide is not alloyed with any other material such as carbon, metal carbide, or metal germanide. For the exclusion of other material that would adversely impact the conductivity of the contacts, the silicide material according to the first group of embodiment of the present invention is herein referred to as “unalloyed silicide.” It should be understood that above exclusion does not mean an exclusion of conventional electrical dopants, such as boron, antimony, phosphorus, and arsenic, which have long been used in the semiconductor industry to electrically dope silicon to increase its conductivity. The exclusion referred to other contact materials such as metal germanide, metal carbide, and carbon that affect the contact resistance adversely. It is possible for the silicon material in the newly formed silicon layer to be doped with conventional electrical dopants listed above. The newly formed silicon layer is, however, essentially free of carbon, metal carbide, or metal germanide.
Selective silicon epitaxy is preferably used for the selective silicon deposition as noted above. The resulting structure according to the first group of the present invention is as follows. If the metal deposited during the silicide formation process does not consume all of the silicon material in the newly formed silicon layer, the resulting structure for each of the source and drain regions includes a stack that contains an unalloyed metal silicide, an epitaxial silicon layer, and an epitaxial silicon alloy layer. If the metal deposited during the silicide formation process consumes all of the silicon material in the newly formed silicon layer, the resulting structure for each of the source and drain regions includes a stack that contains an unalloyed metal silicide and an epitaxial silicon alloy layer. The epitaxial silicon alloy layer is embedded into the body of the transistor structure.
According to a second group of embodiments in the present invention, the needs stated above are also addressed by providing a silicon material onto the surface of the source region and the drain region before the formation of silicide. In this case, an embedded silicon germanium alloy must be introduced into the source and drain regions of the transistors, if at all. Preferably, the embedded silicon germanium epitaxial alloy is embedded into the source and drain regions of the PFETs while the source and drain regions of the NFETs contain only silicon at this point.
Thereafter, a silicon material that is essentially free of carbon or germanium is deposited by a selective silicon deposition process over the silicon and silicon germanium alloy to form a new silicon layer. Since no carbon has been intentionally introduced into the source and drain regions of any transistor up to this point, the newly formed silicon layer are completely free of carbon at this point. Also, the silicon material in the newly formed silicon layer is “essentially” free of germanium since the reactants in the silicon selective epitaxy process provide only silicon material onto the existing silicon alloy surfaces. Also, compared to the rate of surface diffusion which must occur for a successful epitaxy process, the rate of bulk diffusion for germanium at a typical temperature of the silicon selective epitaxy is much lower and therefore, only a small amount of germanium, often a trace amount, diffuses into the newly formed silicon layer through the interface between the silicon germanium alloy layers and the new silicon layer. Any other material in the silicon layer that are newly formed by selective silicon epitaxy is only in minute quantities and therefore, the silicon layer can be considered essentially free of carbon or germanium at this point.
According to the second group of embodiments of the present invention, Si:C alloy is thereafter formed through conventional selective epitaxy of silicon with carbon doping as described in Cheng et al., or alternatively, performed by carbon implantation followed by an anneal. The latter is preferred for the ease and simplicity of the process. The details of the process methods for the formation of silicon carbon alloy are identical to the methods described above for the same purpose according to the first group of embodiments.
As with the first group of embodiments, the doping of the source and drain regions for both PFETs and NFETs may be performed at any point after the formation of the embedded silicon germanium alloy and before the deposition of metal for contact formation.
Metal is thereafter deposited on the surface of the source and drain regions of both PFETs and NFETs. In contrast to the first group of embodiments, two varieties of semiconductor surfaces exist at this point. The first variety of surfaces is the surfaces of a silicon layer deposited over the silicon germanium alloy, whether doped with conventional electrical dopants such as boron, antimony, phosphorus, and arsenic or undoped as pure silicon material. This is in contrast with a silicon alloy material, such as a silicon carbon alloy or a silicon germanium alloy, whether doped with conventional electrical dopants or not. Preferably, the first variety of surfaces is formed in the PFET area. The second variety of surfaces are the surfaces of Si:C alloy, whether doped with conventional electrical dopants such as boron, antimony, phosphorus, and arsenic or undoped as pure silicon material, on which metal is deposited for contact formation. The second variety of surfaces does contain carbon. Preferably, the second variety of surfaces is formed in the NFET area.
The second group of embodiments provides unalloyed silicide only over the silicon germanium alloy but not over the Si:C alloy. As with the first group of embodiments, the second group of embodiments also increases the height of the source and the drain, as defined by the interface between the contact material and the semiconductor material, significantly higher than an equivalent structure that does not utilize a selective silicon deposition during the process flow. However, since all the material deposited by selective silicon deposition turned into silicon carbon alloy under the second variety of surfaces, given the same thickness for the newly grown silicon layer, the amount of silicon carbon alloy above the gate dielectric is more according to the second group of embodiments than the corresponding amount according to the first group of embodiments. Hence, the stress enhancement is more on devices with embedded silicon carbon alloy according to the second group of embodiments.
Selective silicon epitaxy is preferably used for the selective silicon deposition as noted above. The resulting structure according to the second group of the present invention is as follows. If the metal deposited during the silicide formation process does not consume all of the silicon material in the newly formed silicon layer, the resulting structure for the source and drain regions formed with embedded silicon germanium alloy includes a stack that contains an unalloyed metal silicide, an epitaxial silicon layer, and an epitaxial silicon germanium alloy layer. If the metal deposited during the silicide formation process consumes all of the silicon material in the newly formed silicon layer, the resulting structure for the source and drain regions formed with embedded silicon germanium alloy includes a stack that contains an unalloyed metal silicide and an epitaxial silicon alloy layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing simulated results of stress in the channel as a function of the height of an epitaxially grown silicon carbon material in the source and drain regions.
FIGS. 2-7 are sequential vertical cross-sectional views of step(s) of fabricating a pair of an NFET and a PFET according to the first through twelfth embodiments of the present invention.
FIG. 8 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the first, second, eleventh, and twelfth embodiments of the present invention.
FIG. 9 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the first and second embodiments of the present invention.
FIG. 10 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the first and second embodiments of the present invention and also shows features of the eleventh and twelfth embodiments.
FIG. 11 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the first and second embodiments of the present invention.
FIG. 12 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the first embodiments of the present invention and also shows features of the third, fifth, seventh, ninth, and eleventh embodiments.
FIG. 13 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the second embodiments of the present invention and also shows features of the fourth, sixth, eighth, tenth, and twelfth embodiments.
FIG. 14 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the third through sixth embodiments of the present invention.
FIG. 15 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the third and fourth embodiments of the present invention.
FIG. 16 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the third and fourth embodiments of the present invention and also shows features of the fifth and sixth embodiments.
FIG. 17 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the seventh through tenth embodiments of the present invention.
FIG. 18 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the seventh through eighth embodiments of the present invention and also shows features of the eleventh and twelfth embodiments.
FIG. 19 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the seventh and eighth embodiments of the present invention.
FIG. 20 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the seventh embodiment of the present invention.
FIG. 21 is a vertical cross-sectional view of step(s) of fabricating a pair of an NFET and a PFET according to the eighth embodiment of the present invention.
FIGS. 22-23 are sequential vertical cross-sectional views of step(s) of fabricating a pair of an NFET and a PFET according to the ninth through twelfth embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Before describing the present invention in detail, a discussion on the advantage of increasing the height of the source and drain is provided. The height of the source and drain is defined as the vertical distance between the interface of the contact material and the semiconductor material and the interface between the gate dielectric and the channel. FIG. 1 is the result of a simulation wherein the uniaxial stress along the direction of the channel in an NFET with embedded epitaxial silicon carbon in the source and drain is plotted as a function of the height Z of the source and drain. A positive number for Z implies that the interface between the contact material, containing metal silicide, carbon, and metal carbide, and the embedded silicon carbon alloy in the source and drain is higher than the interface between the gate dielectric and the channel. A negative number for Z implies the opposite. As is obvious from the simulation results, the higher the interface between the silicon carbon alloy and the contact material, the higher the stress, hence the higher the degree of enhancement of the mobility of electrons.
This point is relevant to the present invention in that structures that produce more positive Z, that is, those wherein the contact material is located higher than and farther away from the channel are advantageous for enhancing electron mobility. As described below, the present invention may be categorized into two groups, and both groups achieve this advantage.
The present invention may also be presented in at least twelve different embodiments. All of these embodiments share some common processes and features. Therefore, the present invention is described in detail for the first embodiment, although other embodiments may also be demonstratively illustrated in the various drawings. Thereafter, differences among different embodiments of the present invention are compared and described.
In typical CMOS processing, some areas of the surface of the semiconductor substrate are used for building PFET structures. These areas are collectively called “the PFET area” herein. Similarly, some other areas of the surface of the semiconductor substrate are used for building NFET structures. They are collectively called “the NFET area” herein. An exemplary PFET structure in the PFET area and an exemplary NFET structure in the NFET area at various stages of the manufacturing sequences are described for the description of the present invention herein.
Referring to FIGS. 2-12 , structures according to a first embodiment of the present invention are sequentially shown in various stages of manufacturing. FIG. 2 shows a schematic vertical cross section of a PFET structure 301 and an NFET structure 401 immediately after the formation of gate patterns by lithography and etching. The substrate consists of a semiconductor substrate 10 , a buried oxide layer 12 , the body 120 of a PFET structure 301 , the body 220 of an NFET structure 401 , regions with PFET extension implant 140 , regions with NFET extension implant 240 , and shallow trench isolation (STI) 22 that separates the PFET structure 301 and the NFET structure 401 . A gate stack comprising a gate dielectric 30 , gate polysilicon 32 , a gate cap oxide 34 , and a gate nitride layer 36 is also provided within each of the PFET structure 301 and the NFET structure 401 . As is known in the art, the exact composition of the gate stack may be altered to optimize transistor performance. The apparent overlap of the PFET region 301 or the NFET region 401 with STI 22 is incidental and only for the sake of depicting the entirety of the body of the transistor clearly within each transistor structure. STI does not belong to either the PFET structure 301 or the NFET structure 401 .
The body 120 of the PFET structure 301 and the regions with PFET extension implant 140 are comprised of crystalline silicon that maintains contiguous single crystalline structure among adjacent elements unless separated by STI 22 . Similarly, the body 220 of the NFET structure 401 and the regions with NFET extension implant 240 are also comprised of crystalline silicon that maintains contiguous single crystalline structure among adjacent elements unless separated by STI 22 .
FIG. 3 shows a schematic vertical cross section of a PFET structure 302 and an NFET structure 402 after the formation of the first spacers 38 on the walls of the gate stacks, followed by a blanket deposition of a second spacer stack 55 . In a preferred version of the first embodiment, the second spacer stack 55 comprises a stack of an oxide layer 51 and a nitride layer 53 . However, use of one oxide layer, one nitride layer, and a stack comprising more than two dielectric layers for the second spacer stack 55 is herein contemplated also.
A first photoresist is then applied over the second spacer stack 55 and patterned to cover the portion of the second spacer stack 55 over the NFET area while exposing the portion of the second spacer stack 55 over the PFET area. A first reactive ion etch (RIE) is performed to form second PFET spacers 154 out of the second spacer stack 55 . In a preferred version of the first embodiment, the second PFET spacers 154 comprise PFET spacer oxide layers 150 and PFET spacer nitride layers 152 . The first reactive ion etch proceeds until at least the silicon surface of the PET structure 302 in FIG. 3 is exposed. Preferably, the first RIE continues further into the body 120 of a PFET structure 302 such that height of the exposed silicon surface in the source/drain region is lower than the height of the gate dielectric 30 as depicted in a PFET structure 303 in FIG. 4 . While the first RIE removes portions of the regions with PFET extension implant 140 , the remainder of the regions with PFET extension implant 140 under the gate stack is preserved on the silicon substrate. This is referred to as “intermediate PFET extensions” 142 hereafter. During the first RIE, an NFET structure 403 is covered with a first layer of photoresist 57 to prevent any etching of the material in the regions with NFET extension implant 240 . The first RIE stops before all silicon material above the buried oxide layer 12 is consumed by the etching process in the exposed source/drain area.
The first layer of photoresist 57 is then stripped leaving the second spacer stack 55 over the NFET structure 403 in the NFET area. This is because typical resist material is not capable of withstanding the relatively high temperature during a selective epitaxy process for silicon germanium alloy deposition. After suitable surface preparation such as a wet clean, selective epitaxy of silicon germanium alloy is performed to grow embedded silicon germanium alloy 160 ′ in the source and drain regions in the PFET area. The embedded silicon germanium alloy 160 ′ is epitaxially aligned to the body of the PFET 120 so that the body of the PFET 120 , the intermediate PFET extensions 142 , and the embedded silicon germanium alloy 160 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 .
A second layer of photoresist 59 is then applied and lithographically patterned to cover the PFET area and expose the NFET area as shown in FIG. 5 . At this point, a PFET structure 304 is covered by the patterned second photoresist 59 and an NFET structure 404 is covered by the second spacer stack 55 . A second RIE is performed to form second NFET spacers 254 out of the second spacer stack 55 . In a preferred version of the first embodiment, the second NFET spacers 254 comprise PFET spacer oxide layers 250 and PFET spacer nitride layers 252 . FIG. 6 shows a PFET structure 305 and an NFET structure 405 after the completion of the second RIE.
The second layer of photoresist 59 is then removed. FIG. 7 shows a PFET structure 306 and an NFET structure 406 after the removal of the photoresist 59 .
The electrical doping of the source and drain regions for the PFET area and NFET area are done at this stage using a conventional lithographic method and an ion implantation method. If desired, activation of the electrical dopants by anneal may be performed immediately after the ion implantation steps or they may be postponed to a later stage in the process flow. Conventional electrical dopants known in the art include boron, phosphorus, arsenic, and antimony. A PFET structure 307 in FIG. 8 contains P-doped silicon 162 and P-doped silicon germanium alloy 162 ′ in the source and the drain regions. The “PFET extension” 144 is the part of the intermediate PFET extensions 142 that did not receive extra dopants during the electrical doping of the source and drain regions. An NFET structure 407 in FIG. 8 contains “intermediate N-doped silicon” 261 in each of the source and the drain regions. The “NFET extension” 244 is the portion of regions with NFET extension implant 240 that did not receive extra dopants during the electrical doping of the source and drain regions. The body of the PFET 120 , the PFET extension 144 , the P-doped silicon 162 , and the P-doped silicon germanium alloy 162 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 . Likewise, the body of the NFET 220 , the NFET extension 244 , and the intermediate N-doped silicon 261 form a contiguous single crystalline structure within each area surrounded by STI 22 .
While germanium is not an electrical dopant, amorphization implant using germanium as part of the electrical doping process for the sake of improving the doping of the source and drain regions is known in the art. However, the amount of germanium according to this method is typically limited to less than 1% of the material within the source/drain region in atomic concentration. Typically, carbon or germanium above 1% in atomic concentration is not considered to be part of conventional electrical doping of the source and drain regions. These criteria are base on the ability of these dopants to change the stress in any substantial way in the source and drain regions. During the electrical doping of the source and drain regions according to the first embodiment of the present invention, no significant stress is generated within the source and drain regions.
A third layer of photoresist 175 is then applied and lithographically patterned to cover the PFET area as shown in FIG. 9 . Carbon is implanted into the NFET area to dope the source and drain regions of an NFET structure 408 as shown in FIG. 9 . A PFET structure 308 is protected from the carbon implantation by the third layer of photoresist 175 . The implantation of carbon into the NFET area changes each of the intermediate N-doped silicon 261 into two parts: N-doped silicon carbon alloy 261 ′ and N-doped silicon 262 . The photoresist 275 is thereafter removed.
The implanted carbon immediately after implantation does not necessarily occupy substitutional sites in the crystal structure. As a consequence of the implantation, the N-doped silicon 262 has crystalline structure with few defects at this point, the N-doped silicon carbon alloy 261 ′ is amorphous. By annealing the substrate at a high temperature at this point, an N-doped single crystalline silicon carbon alloy, an “N-doped Si:C alloy” 262 ′, is epitaxially regrown within the N-doped silicon carbon alloy 261 ′ with the N-doped silicon 262 as the epitaxial template. This process is called “solid phase epitaxy” (SPE) and the methods of performing a solid phase epitaxy are known in the art. In essence, the silicon and carbon atoms in the N-doped silicon carbon alloy 261 ′ align themselves epitaxially to the underlying lattice structure beginning from the interface between the N-doped silicon 262 and the original N-doped silicon carbon alloy 261 ′. During the SPE, after one atomic layer of Si:C is epitaxially aligned to the underlying single crystalline lattice, the next atomic layer of Si:C is formed. This process continues layer by layer until the entire material within the original N-doped silicon carbon alloy 261 ′ is incorporated into the single crystalline structure and form an Si:C alloy. Since the original N-doped silicon carbon alloy 261 ′ contains N-type dopants, the N-type dopants are also epitaxially incorporated into the Si:C structure and forms an N-doped Si:C alloy 262 ′.
Any of the processes known for SPE may be utilized to practice the present invention. Preferably, the anneal process is a laser anneal with a peak temperature between 700° C. and 1428° C. Once the N-doped Si:C alloy 262 ′ are formed in the source and drain regions in the NFET area, the body of the NFET 220 , the NFET extension 244 , the N-doped Si:C alloy 262 ′ and the N-doped silicon 262 form a contiguous single crystalline structure within each area surrounded by STI 22 .
Thereafter, selective silicon deposition is performed on the PFET area and the NFET area. During the selective silicon deposition, reactants containing the source material for silicon such as SiH 4 , Si 2 H 6 , SiHCl 3 , SiH 2 Cl 2 , or SiH 3 Cl are introduced into a process chamber containing a semiconductor substrate along with an etchant such as HCl or NH 4 Cl and a carrier gas such as H 2 . Sometimes, under suitable conditions, reactants that contain high atomic ratio of chlorine to hydrogen may decompose within the process chamber to provide enough etchants by themselves. The semiconductor substrate contains two types of surfaces: semiconductor surfaces and dielectric surfaces. The surfaces of silicon or silicon alloys are semiconductor surfaces. The surfaces of dielectric films such as silicon oxide, silicon nitride are dielectric surfaces. Due to the presence of etchants among the reactants, the deposition process competes with an etch process during a selective silicon deposition. Deposition of new silicon material does not occur on the dielectric surfaces since any nucleation of silicon atoms is immediately etched by the etchants. Therefore, the deposition of new silicon material occurs only on silicon surfaces or silicon alloy surfaces. In a typical transistor structure, each region of silicon alloy material or silicon material, whether it be a source region or a drain region, is surrounded by dielectric materials such as STI, and therefore, a new layer containing silicon and grown epitaxially by selective silicon deposition, to be called a “silicon layer” hereafter, is also surrounded by dielectric materials.
Depending on the mobility of the silicon atoms and the impurity levels in the ambient gas stream in the process chamber, the new silicon layer may itself be epitaxially aligned to the underlying silicon or silicon alloy or it may form polysilicon, microcrystalline silicon, or even amorphous silicon. In a preferred version of the first embodiment of the present invention, the selective silicon deposition process is a selective silicon epitaxy, wherein the new silicon layer is epitaxially aligned to the underlying silicon or silicon alloy. In this process, the substrate is typically at a high enough temperature to provide sufficient surface mobility to the silicon atoms that originate from the silicon precursors in the reactant gas stream and adsorb on the growth surface. Also, the impurity level in the gas stream is kept low to prevent impurities from landing on the growth surface and cause defects in the crystalline structure.
The epitaxial alignment of the silicon layer with the underlying silicon alloys is advantageous to the performance of the transistor because any grain boundary or crystalline defect serves as a scattering center and reduces the carrier mobility, which is the case with polysilicon, microcrystalline silicon, amorphous silicon, and a silicon material that loses epitaxial alignment with the underlying single crystalline silicon. If some of the silicon material in the silicon layer is not reacted during the formation of contacts, the remaining silicon material contains many of the crystalline defects and the scattering of electrons or holes at the defects decreases the conductivity of the source or drain region. This problem may be avoided only if all of the silicon material in the silicon layer is consumed during the formation of contacts by reacting with the deposited metal for metal silicide formation. Epitaxially aligned silicon in the silicon layer does not cause any negative impact on the contact resistance even if not all of the silicon material in the silicon layer is reacted with metal. Due to this advantages provided by epitaxial alignment of the silicon layer to the underlying crystalline structure, all the embodiments of the present invention, including the first embodiment, are described with a selective silicon epitaxy process for the selective silicon deposition.
FIG. 10 shows a PFET structure 309 and an NFET structure 409 after a selective silicon epitaxy process. The PFET structure 309 now contains silicon layer 170 over the P-doped silicon germanium alloy 162 ′, which in turn is disposed on the P-doped silicon 162 . The NFET structure 409 contains silicon layer 270 over the N-doped Si:C alloy 262 ′, which in turn is disposed on the N-doped silicon 262 . The silicon material in the newly formed silicon layer is essentially free of carbon or germanium since the reactants in the silicon selective epitaxy process provide only silicon atoms onto the existing silicon alloy surfaces. Also, compared to the rate of surface diffusion which must occur for a successful epitaxy process, the rate of bulk diffusion for germanium or carbon at the temperature of the silicon selective epitaxy is much lower and therefore, only a small amount of carbon or germanium, often a trace amount, diffuses into the newly formed silicon layer through the interface between the silicon alloy layers and the new silicon layer. Any other material in the silicon layer that is newly formed by selective silicon epitaxy is only in minute quantities and therefore, the silicon layer can be considered essentially free of carbon or germanium.
At this point, the body of the PFET 120 , the PFET extension 144 , the P-doped silicon 162 , the P-doped silicon germanium alloy 162 ′, and the silicon layer 170 over the P-doped silicon germanium alloy 162 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 . Likewise, the body of the NFET 220 , the NFET extension 244 , the N-doped silicon 262 , the N-doped Si:C alloy 262 ′, and the silicon layer 270 over N-doped Si:C alloy 262 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 .
Thereafter, the gate cap oxide 34 and the gate nitride layer 36 are removed. Metal 80 is then deposited over the silicon substrate in an ultra high vacuum chamber by physical vapor deposition (PVD). FIG. 11 shows a PFET structure 310 and an NFET structure 410 after such metal deposition. The deposited metal is reacted with the silicon in the underlying silicon layer in the source and drain regions and also with the polysilicon within the gate stack. According to the first embodiment of the present invention, only a portion of the silicon layer is consumed to form a metal silicide while the remaining portion of the silicon layer is not consumed during the formation of said contact material. Since the silicon layer deposited through selective silicon deposition, preferably selective silicon epitaxy, is essentially free of carbon or germanium, the contact material is not a mixture or alloy of metal silicide and other material, such as metal germanide, metal carbide, or even carbon. The contact material is an unalloyed metal silicide in both a PFET structure 311 and an NFET structure 411 in FIG. 12 .
In the final structure of the transistors according to the first embodiment of the present invention, the body of the PFET 120 , the PFET extension 144 , the P-doped silicon 162 , the P-doped silicon germanium alloy 162 ′, and the unreacted silicon layer 190 over the P-doped silicon germanium alloy 162 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 . Likewise, the body of the NFET 220 , the NFET extension 244 , the N-doped silicon 262 , the N-doped Si:C alloy 262 ′, and the unreacted silicon layer 290 over the N-doped Si:C alloy 262 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 .
While there is no electrical dopants in the unreacted silicon layer 190 over the P-doped silicon germanium alloy 162 ′ or in the unreacted silicon layer 290 over the N-doped Si:C alloy 262 ′ in FIG. 12 according to the present invention, one of ordinary skill in the art are cognizant of the fact that the diffusion of electrical dopants over a short distance is readily achievable through a moderate anneal. Therefore, the diffusing electrical dopants from the underlying N-doped Si:C layers or P-doped silicon germanium alloy layers through anneal to reduce the contact resistance of the source and drain regions is an obvious application of this invention. On the other hand, N-type and P-type dopants can be implanted into the top Si layer on top of Si:C and SiGe, respectively, before silicidation.
The fact that the first embodiment of the present invention provides unalloyed silicide over both the silicon germanium alloy and silicon carbon alloy in turn enables low contact resistance for devices with embedded silicon alloys in the source and drain regions. In addition, the height of the source and the drain, as defined by the interface between the contact material and the semiconductor material, is significantly higher than an equivalent structure that does not employ selective silicon deposition during the process flow. The increased height of the source and drain increases the stress on the channels of the transistors with embedded silicon alloys.
While the first embodiment of the present invention is described with lithographic steps at each stage of the process flow, those skilled in the art would recognize that some simplification of the process flow is possible by utilizing common litho masks for consecutive processes when permitted. Also, substitution of noncritical elements of the present invention with known material with similar properties would be similarly recognized.
According to the second embodiment of the present invention, all process steps and structures are identical as in the first embodiment of the present invention until the deposition of metal 80 for the purpose of contact formation is completed as in FIG. 11 . During the reaction of the metal 80 with the underlying silicon layer 170 over silicon germanium alloy 162 ′ and with the underlying silicon layer 270 over the N-doped Si:C alloy 262 ′, the metal 80 is reacted with all the silicon material that was deposited during the selective silicon deposition. The resulting structure for the PFET 321 and the resulting structure for the NFET 421 are shown in FIG. 13 . Each one of the source and drain regions for a PFET contains a stack of an unalloyed metal silicide 186 and an electrically doped epitaxial silicon germanium alloy layer 162 ′. Each one of the source and drain regions for an NFET contains a stack of an unalloyed metal silicide 286 and an N-doped Si:C alloy 262 ′. Allowing the reaction of the metal to consume a portion of the underlying doped silicon germanium alloy 162 ′ or a portion of the underlying N-doped Si:C alloy 262 ′ is also contemplated herein.
The third through the twelfth embodiments of the present invention use the elements of the first and second embodiments of the present invention with some alteration. Description of these embodiments is done first by comparing the differences across the various embodiments of the present invention and then specific features and ramifications of each embodiment are described.
The twelve embodiments are classified into two groups of embodiments. A first group of embodiments include the first through sixth embodiments. A second group of embodiments include the seventh through twelfth embodiments. Within the first group of embodiments, the formation of the embedded silicon carbon alloy in the source and drain regions of the NFET area precedes the growth by selective deposition of a silicon material of a silicon layer in the PFET area and the NFET area. Within the second group of embodiments, the growth by selective deposition of a silicon material of a silicon layer in the PFET area and the NFET area precedes the formation of the embedded silicon carbon alloy in the source and drain regions of the NFET area.
In all of the twelve embodiments, formation of an embedded silicon germanium alloy, a source and drain implant for electrical doping, formation of an embedded silicon carbon alloy, and a selective silicon deposition, and formation of contact material are included. The order and details of processing methods and resulting structures are different depending on which embodiment is pursued. While the formation of Si:C alloy is preceded by the formation of SiGe alloy most of the time, third through sixth embodiments allow a reversal of process sequences between the two processes. A summary of the differences in the order of the process flow among the various embodiments is presented in Table 1.
TABLE 1
Order of the process flow for various embodiments according to the present
invention
embodiments
First process
Second process
Third process
Fourth Process
first and second
embedded SiGe
electrical doping
embedded Si:C
selective silicon
embodiments
alloy formation
on source/drain
alloy formation
epitaxy
third and fourth
embedded SiGe
embedded Si:C
electrical doping
selective silicon
embodiments
or Si:C formation
or SiGe
on source/drain
epitaxy
formation
fifth and sixth
embedded SiGe
embedded Si:C
selective silicon
electrical doping
embodiments
or Si:C formation
or SiGe
epitaxy
on source/drain
formation
seventh and
embedded SiGe
selective silicon
electrical doping
embedded Si:C
eighth
alloy formation
epitaxy
on source/drain
alloy formation
embodiments
ninth and tenth
embedded SiGe
selective silicon
embedded Si:C
electrical doping
embodiments
alloy formation
epitaxy
alloy formation
on source/drain
eleventh and
embedded SiGe
electrical doping
selective silicon
embedded Si:C
twelfth
alloy formation
on source/drain
epitaxy
alloy formation
embodiments
Each pair of two embodiments sharing the same order of in the process flow in Table 1 contains one embodiment (odd numbered embodiment) wherein the reaction of metal 80 as in FIG. 11 is allowed to consume only a part of the silicon layer deposited during the selective silicon epitaxy and the other embodiment (even numbered embodiment) wherein the reaction of metal 80 as in FIG. 11 is allowed to consume the entirety of the silicon layer deposited during the selective silicon epitaxy. This results in differences in the final structure of the PFETs and NFETs.
The combination of the order in the process flow and the degree of reaction of metal 80 with the underlying layers results in the differences in the composition and doping of the various parts of the source and drain regions in the structure. These differences in source and drain regions of a PFET with embedded silicon germanium alloy according to the various embodiments of the present invention are tabulated in Table 2. N/A stands for “Not Applicable” and refers to a state where the relevant object does not exist.
TABLE 2
Composition and doping of a stack comprising a source/drain region in a PFET.
state of
presence and
electrical
electrical
state of
doping on
doping
unreacted
unreacted
Composition of contact
material in
portion of
portion of
material over embedded
the contact
embodiment
silicon layer
silicon layer
SiGe alloy
material
first embodiment
Yes, silicon
none
unalloyed metal silicide
none
second embodiment
No, N/A
N/A
unalloyed metal silicide
none
third embodiment
Yes, silicon
none
unalloyed metal silicide
none
fourth embodiment
No, N/A
N/A
unalloyed metal silicide
none
fifth embodiment
Yes, silicon
P-doped
unalloyed metal silicide
P-doping
sixth embodiment
No, N/A
N/A
unalloyed metal silicide
P-doping
seventh embodiment
Yes, silicon
P-doped
unalloyed metal silicide
P-doping
eighth embodiment
No, N/A
N/A
unalloyed metal silicide
P-doping
ninth embodiment
Yes, silicon
P-doped
unalloyed metal silicide
P-doping
tenth embodiment
No, N/A
N/A
unalloyed metal silicide
P-doping
eleventh embodiment
Yes, silicon
none
unalloyed metal silicide
none
twelfth embodiment
No, N/A
N/A
unalloyed metal silicide
none
Likewise, differences in the source and drain regions of an NFET with embedded silicon carbon alloy according to the various embodiments of the present invention are tabulated in Table 3. As in the first and second embodiments, even though the state of electrical doping on unreacted portion of silicon layer may initially contain no electrical dopants, the diffusion of electrical dopants over a short distance is readily achievable through a moderate anneal. Therefore, the diffusing electrical dopants from the underlying N-doped Si:C layers or P-doped silicon germanium alloy layers through anneal to reduce the contact resistance of the source and drain regions is an obvious application of this invention.
TABLE 3
Composition and doping of a stack comprising a source/drain region in an
NFET.
state of
presence and
electrical
electrical
state of
doping on
doping
unreacted
unreacted
Composition of contact
material in
portion of
portion of
material over embedded
the contact
embodiment
silicon layer
silicon layer
Si:C alloy
material
first embodiment
Yes, silicon
none
unalloyed metal silicide
none
second embodiment
No, N/A
N/A
unalloyed metal silicide
none
third embodiment
Yes, silicon
none
unalloyed metal silicide
none
fourth embodiment
No, N/A
N/A
unalloyed metal silicide
none
fifth embodiment
Yes, silicon
N-doped
unalloyed metal silicide
N-doping
sixth embodiment
No, N/A
N/A
unalloyed metal silicide
N-doping
seventh embodiment
Yes, Si:C
N-doped
metal silicide, carbon,
N-doping
metal carbide
eighth embodiment
No, N/A
N/A
metal silicide, metal
N-doping
carbide, carbon
ninth embodiment
Yes, Si:C
N-doped
metal silicide, carbon,
N-doping
metal carbide
tenth embodiment
No, N/A
N/A
metal silicide, metal
N-doping
carbide, carbon
eleventh embodiment
Yes, Si:C
none
metal silicide, metal
none
carbide, carbon
twelfth embodiment
Yes, silicon
N/A
metal silicide, metal
none
carbide, carbon
Noteworthy differences in the structures according to the third through twelfth embodiments of the present invention with respect to the first and second embodiments are described below following essential differences in the process flow. Like structures in various embodiments are labeled with the same reference number in the figures to imply that the structure and function are identical to those described in the prior embodiments. Elements with identical structural and functional equivalency are labeled with the same name in various embodiments of the present invention even when the numbers are different. Often, the differences in numbers suggest the presence of different intermediate structures prior to the step in which the element with a different number is introduced.
According to the third and fourth embodiments of the present invention, the embedded silicon germanium alloy 160 ′ in a PFET structure 507 and the embedded Si:C alloy 660 ′ in an NFET structure 607 are formed prior to the electrical doping of the source and drain regions as shown in FIG. 14 . According to a preferred version of the third and fourth embodiments of the present invention, the embedded silicon germanium alloy 160 ′ are formed in the same way as in the first and second embodiments up to the processing steps corresponding to FIG. 7 .
Then, as in FIG. 14 , a PFET structure 507 is covered with a fourth photoresist 575 and carbon is implanted into the NFET structure 607 . The fourth photoresist 575 is removed and the silicon substrate is subjected to an anneal process to form Si:C within the region of the source and the drain with carbon. Identical processes as in the first and second embodiments are employed to form undoped embedded Si:C alloy 660 ′. However, undoped embedded Si:C alloy 660 ′ is not present at any stage of processing according to the first and second embodiments of the present invention. As processing continues according to the third and fourth embodiments, the electrical doping of the source and drain regions are performed thereby producing N-doped Si:C alloy 662 ′ and N-doped silicon 662 in an NFET structure 608 shown in FIG. 15 . These structures are identical to the N-doped Si:C alloy 262 ′ and N-doped silicon 262 in FIG. 10 . Thereafter, selective silicon deposition is performed. Once again, selective silicon epitaxy is assumed for the sake of description of the present invention. A PFET structure 509 and an NFET structure 609 in FIG. 16 are identical to their counterparts in FIG. 10 except for the labels which connote the presence of different structure only prior to that stage of processing.
From the selective silicon epitaxy process on, structures and processes are identical between the first embodiment and the third embodiment. The same holds true between the second embodiment and the fourth embodiment. Obviously, these relationships hold between the final structures as well.
According to the fifth and sixth embodiments of the present invention, the formation of the embedded Si:C alloy is performed first, followed by a selective silicon deposition process, and then an electrical doping of the source and drain regions. Once again, these embodiments also assume selective silicon epitaxy. After the formation of embedded silicon germanium alloy 160 ′ in a PFET structure 507 and embedded Si:C alloy 660 ′ in an NFET structure 607 in the same manner in FIG. 14 as in the third and fourth embodiments of the present invention, a silicon layer is formed directly on the embedded silicon germanium alloy 160 ′ and on the embedded Si:C alloy 660 ′ to form a structure similar to that shown in FIG. 16 . Unlike the structure of FIG. 16 , however, the source/drain region is not doped at this point. In other words, the P-doped silicon 162 and the N-doped silicon 662 in FIG. 16 do not exist and the body 120 of the PFET and the body 220 of the NFET occupy the yet-to-be-formed P-doped silicon 162 and the N-doped silicon 662 respectively according to the fifth and sixth embodiments. Similarly, the P-doped silicon germanium alloy 162 ′ and the N-doped Si:C alloy 662 ′ in FIG. 16 are at this stage not doped with source/drain doping according to the fifth and sixth embodiments.
While these embodiments are not described with figures, in is obvious that all intermediate structures before the electrical doping of the source and drain regions are not doped with dopants. Afterwards, the source/drain doping is performed with suitable masks. The resulting structure is similar to the structure shown in FIG. 16 with the difference being that the silicon layer 170 in FIG. 16 in the third and fourth embodiments is replaced by a P-doped silicon layer and the silicon layer 270 in FIG. 16 in the third and fourth embodiments is replaced by an N-doped silicon layer according to the fifth and sixth embodiments of the present invention. Since the electrical doping of the PFETs and NFETs are performed immediately prior to the deposition of metal, the epitaxially deposited silicon material in the silicon layer is doped with electrical dopants. However, since they were deposited after the formation of silicon germanium alloys and Si:C alloys, there is no carbon or germanium in the epitaxially deposited silicon layer. So, the final structure includes unalloyed metal silicide on electrically doped silicon layer as described in Table 2 and Table 3.
According to the seventh and eighth embodiments of the present invention, the process steps are identical to those according to the first and the second embodiments up to the formation of second NFET spacers 254 as they are shown in FIG. 7 . Instead of electrical doping of the source and drain regions, a selective silicon deposition is performed immediately afterward as shown in FIG. 17 . A PFET structure 707 contains a newly grown silicon layer 770 over the embedded silicon germanium alloy 160 ′ and an NFET structure 807 contains a newly grown silicon layer 870 over the regions with NFET extension implant 240 .
Electrical doping of the source and drain regions of the PFETs and NFETs is performed thereafter. FIG. 18 shows the resulting structures. A PFET structure 708 now contains P-doped silicon 762 , P-doped silicon germanium alloy 762 ′, and a P-doped silicon layer 772 . An NFET structure 808 contains intermediate N-doped silicon 861 and an N-doped silicon layer 872 . The presence of the P-doped silicon layer 772 and the N-doped silicon layer 872 are different features of the seventh and eighth embodiments compared to the first and second embodiments. N-doped Si:C alloy layer 872 ′ is a different feature of the seventh and eighth embodiments compared to the first and second embodiments of the present invention.
Then, a PFET structure 709 is covered with a fifth photoresist 775 and carbon is implanted into the NFET structure 809 as shown in FIG. 19 . The fifth photoresist 775 is removed and the silicon substrate is subjected to an anneal process to form N-doped Si:C alloy 862 ′ within the region of the source and the drain with carbon. Through the carbon implantation and SPE, the N-doped silicon layer 872 in FIG. 18 is converted to an N-doped Si:C alloy layer 872 ′ in FIG. 19 . The N-doped Si:C alloy layer 872 ′ is a different feature of the seventh and eighth embodiments compared to the first and second embodiments. After the removal of the fifth photoresist 775 , metal 80 is deposited in a similar manner described in FIG. 11 and then reacted with the underlying N-doped Si:C alloy layer 872 ′ and the P-doped silicon layer.
According to the seventh embodiment of the present invention, the reaction of the metal 80 is controlled such that the contact formation process consumes only a portion of the N-doped Si:C alloy layer 872 ′ and the P-doped silicon layer. A PFET structure 711 and an NFET structure 811 at this stage is shown in FIG. 20 . The body of the PFET 120 , the PFET extension 144 , the P-doped silicon 762 , the P-doped silicon germanium alloy 762 ′, and the unreacted P-doped silicon layer 772 form a contiguous single crystalline structure within each area surrounded by STI 22 . Likewise, the body of the NFET 220 , the NFET extension 244 , the N-doped silicon 862 , the N-doped Si:C alloy 862 ′, and the unreacted N-doped silicon layer 874 ′ form a contiguous single crystalline structure within each area surrounded by STI 22 .
According to the eighth embodiment of the present invention, the reaction of the metal 80 is controlled such that the contact formation process consumes all of the N-doped Si:C alloy layer 872 ′ and the P-doped silicon layer. A PFET structure 721 and an NFET structure 821 at this stage are shown in FIG. 20 . These structures are like the corresponding structures in FIG. 20 according to the seventh embodiment but the unreacted P-doped silicon layer 772 and the unreacted N-doped silicon layer 874 ′ are not present.
In both the seventh and eighth embodiments, since the P-doped silicon layer 772 does not contain any germanium or carbon, the contact material formed over the PFET area is unalloyed metal silicide 786 as is the case with the first through the sixth embodiments, that is, without any metal germanide, metal carbide, or carbon. However, due to the presence of carbon in the Si:C alloy layer 872 ′, the contact material 886 formed over the NFET area is not free of carbon and metal carbide, and is therefore not an “unalloyed metal silicide” according to the definition above. It is instead an alloy of metal silicide, metal carbide, and carbon. The relative content of metal carbide and carbon may be controlled depending on the details of the process.
According to the ninth and tenth embodiments of the present invention, the process steps are identical to those according to the seventh and eighth embodiments up the selective silicon deposition as shown in FIG. 17 . Instead of electrical doping of the source and drain regions thereafter, the formation of Si:C alloy is performed instead. Identical processing methods are used as in the seventh and eighth embodiments.
As shown in FIG. 22 , a PFET structure 908 is covered with a sixth photoresist 975 and carbon is implanted into the NFET structure 1008 . This introduces carbon into the epitaxially grown silicon layer as well as into the silicon material from the substrate. The sixth photoresist 975 is then removed and the silicon substrate is subjected to an anneal process. The SPE during the anneal process produces Si:C alloy 1060 ′ and an Si:C layer 1070 ′ in the NFET structure 1008 . The lack of doping in the Si:C layer 1070 ′ in the ninth and tenth embodiments is a new feature not found in prior embodiments. Resist 975 is removed after the SPE.
Electrical doping of the source and drain regions of the PFETs and NFETs is performed thereafter. FIG. 23 shows the resulting structures. A PFET structure 909 now contains P-doped silicon 762 , P-doped silicon germanium alloy 762 ′, and P-doped silicon layer 772 . An NFET structure 1009 contains N-doped silicon 1062 , N-doped Si:C alloy 1062 ′, and N-doped Si:C alloy 1072 ′. The PFET structure 909 and the NFET structure 1009 at this stage according to the ninth and tenth embodiments are identical to the structures obtained after SPE according the seventh and eighth embodiments of the present invention. Subsequent processes are identical as well.
According to the ninth embodiment, the reaction of the metal with the underlying semiconductor material is controlled in an identical manner to that according to the seventh embodiment, and consequently, identical structure results in the end. The same relationship holds true between the eighth embodiment and the tenth embodiment.
According to the eleventh and twelfth embodiments, the electrical doping of the source and drain regions follow the formation of silicon germanium alloy. This results in the same structure as shown in FIG. 8 according to the first and second embodiments of the present invention. Instead of a formation of embedded Si:C, selective epitaxial growth of silicon layers over the source/drain regions is performed subsequently. The resulting structure is similar to that shown in FIG. 10 but does not contain any embedded Si:C. Compared to FIG. 10 according to the first and second embodiments, the structure according to the eleventh and twelfth embodiments has an intermediate N-doped silicon 861 as shown in FIG. 18 in lieu of an N-doped Si:C alloy 262 ′ in FIG. 10 . However, this structure is different from the structure shown in FIG. 18 according to the seventh and eighth embodiments. Compared to FIG. 18 according to the seventh and eighth embodiments, the structure according to the eleventh and twelfth embodiments has undoped silicon layers 170 , 270 in lieu of P-doped silicon layer 772 and N-doped silicon layer 872 .
While these embodiments are not described with figures, in is obvious that the epitaxially grown silicon layers 170 , 270 are not doped since the selective epitaxy is performed after the source/drain implantation and that all intermediate structures before the Si:C formation does not contain any embedded Si:C structures. Afterwards, the formation of Si:C follows utilizing the methods described above. The resulting structure is similar to the structure shown in FIG. 10 with the difference being that the silicon layer 270 in FIG. 10 in the first and second embodiments is replaced by an undoped Si:C silicon layer. The silicon material for the undoped Si:C layer was provided by the reactants of the selective epitaxy process and the carbon material was provided during the Si:C formation process. Thereafter, metal 80 is deposited for metallization and reacted partially according to the eleventh embodiment or reacted fully according to the twelfth embodiment. The resulting structure produces contact material that the seventh through tenth embodiments of the present invention produces with the only difference being that the contact material has less electrical dopants, which is insignificant for the performance of the contact material.
While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention and the following claims. | While embedded silicon germanium alloy and silicon carbon alloy provide many useful applications, especially for enhancing the mobility of MOSFETs through stress engineering, formation of alloyed silicide on these surfaces degrades device performance. The present invention provides structures and methods for providing unalloyed silicide on such silicon alloy surfaces placed on semiconductor substrates. This enables the formation of low resistance contacts for both mobility enhanced PFETs with embedded SiGe and mobility enhanced NFETs with embedded Si:C on the same semiconductor substrate. Furthermore, this invention provides methods for thick epitaxial silicon alloy, especially thick epitaxial Si:C alloy, above the level of the gate dielectric to increase the stress on the channel on the transistor devices. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to U.S. Provisional Application Ser. No. 60/975,375, filed on Sep. 26, 2007 and entitled “Interior Window Trim Kit,” which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to construction materials and, in particular, to window trim assemblies.
BACKGROUND
[0003] Conventional methods of installing interior window trim have several disadvantages. For example, traditional wood trim installations require the services of skilled tradesmen because precise woodworking is necessary to measure, cut, and join trim boards to each other and to the window or wall. These traditional installations require the transport of cumbersome tools to and from the job site and can result in wasted materials and lost time spent cleaning up. As a result, this method of installing trim is time consuming and expensive. This method is often used, despite these disadvantages, because the appearance and high-quality fit and finish of expert-crafted wood trim has been a desirable feature for home and building owners.
[0004] Other methods and devices for trimming a window do not use wood, but instead use extruded vinyl, aluminum, or plastic trim pieces. These pieces are usually cut to fit on site from lengths of modular extruded stock. The pieces are typically then fastened to the window frame, wall, or jamb surface using a series of clips or mounting brackets. Some of these devices have parts that snap together, slide together, or are screwed or nailed together, for example U.S. Pat. No. 4,250,673 of Hubbard and U.S. Pat. No. 5,941,033 of Adams.
[0005] At least one disadvantage of these methods and devices is that the time and skill required to measure and cut the various extruded pieces is almost as burdensome and inefficient as that required for conventional wood trim. Further, the resulting window trim has the appearance of being made from some material other than wood and lacks the professional fit and finish that expert carpenters are able to achieve by constructing custom wood trim with mitered finger joints.
[0006] Another disadvantage with these methods and devices for trimming a window is that the snap-fit clips or mounting brackets often used can fail to reliably secure the trim pieces to the wall, or can leave aesthetically undesirable gaps between adjacent surfaces.
[0007] Accordingly, there exists a need for window trim assemblies that are easy-to-install, while at the same time providing the aesthetically and functionally desirable fit and finish of expert-crafted wood trim.
SUMMARY
[0008] The present invention is directed towards an interior window trim assembly that can engage with channels found in popularly used window frames. The window trim assembly can provide a pre-assembled, easy-to-install treatment for the jamb and casing surfaces of a window and can provide the same aesthetically and functionally desirable fit and finish as wooden trim crafted on site by expert tradesmen.
[0009] In one aspect of the invention, the window trim assembly includes a generally rectangular, prefabricated casing having at least a horizontal wooden top casing element, two or more vertical wooden side casing elements and a set of extension jambs joined to the casing and extending perpendicular thereto, the jambs being adapted to engage a channel formed in a window frame and provide desired spacing between the window frame and the casing such that the casing can lie substantially flat against a finished interior wall.
[0010] The trim assembly can further include at least one bottom casing element. In one embodiment, the bottom element can take the form of traditional apron and stool members. In another embodiment, the bottom element can be similar in style to the top and side elements to form a simple “picture frame” type casing.
[0011] In another aspect of the invention, the window trim assembly can include a plurality of extension jambs adapted to engage a channel formed in a window frame and provide desired spacing between the window frame and a plurality of casing elements such that the casing elements can lie substantially flat against a finished interior wall.
[0012] The present invention provides an interior window trim assembly that can attach to extruded vinyl, aluminum, or other types of window frames. The assembly includes trim elements for both the jamb and casing surfaces of the window area so as to provide a complete interior trim solution. The elements of the trim assembly can be sanded, primed, stained, painted, or cleaned off-site so as to provide a greater ease and efficiency of installation. Alternatively, the elements of the trim assembly can be pre-finished on-site prior to installation.
[0013] In another aspect of the invention, at least some of the casing element can be connected by mitered joints, e.g., a mortise and tenon, biscuit, or other suitable joinery to achieve the same appearance and durability as wooden window trim crafted onsite by expert tradesmen.
[0014] In another aspect of the invention, the window trim assembly can be designed such that sturdy, easy to install fasteners such as nails, screws, or staples can be used to affix the assembly to the wall or window frame.
[0015] Additional objects, advantages, and novel features of the invention will be set forth in part in the description as follows and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0017] FIG. 1 is a perspective view of an interior window trim assembly constructed according to an embodiment of the present invention;
[0018] FIG. 2 is a front elevational view of a window trimmed using the interior window trim assembly of FIG. 1 ;
[0019] FIG. 3A is a cross sectional view from above of an un-finished window installed in a building wall;
[0020] FIG. 3B shows the same cross sectional view as FIG. 3A , only the window of FIG. 3B is finished using the interior window trim assembly of FIG. 1 ;
[0021] FIG. 4A is a perspective view of a mortise and tenon joint that can be used in constructing the interior window trim assembly of FIG. 1 ;
[0022] FIG. 4B is a perspective view of a biscuit joint that can be used in constructing the interior window trim assembly of FIG. 1 ; and
[0023] FIG. 5 is a front elevational view of another exemplary embodiment of the present invention where the trim design is of a simple picture frame type.
DETAILED DESCRIPTION
[0024] Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
[0025] In a typical unfinished window installation, the interior wall surface can have a ragged or rough edge where it meets the perimeter of the rough window opening. These rough edges can be unsightly and typically require some kind of finish treatment. Additionally, absent the installation of finish trim, the unsightly framing member surfaces of the window opening can be left exposed to the interior of the home or building. These surfaces are normally covered by other expensive, inefficient trimming methods. Described herein is an interior window trim assembly that can be used more easily and efficiently to finish such a window installation. The interior window trim assembly can include a casing to cover the rough edges of the interior wall surface and a plurality of extension jambs to mask the framing member surfaces of the window opening.
[0026] FIG. 1 shows an interior window trim assembly 10 . The assembly can include a pre-fabricated casing 12 that can further include a horizontal top casing element 14 and two vertical side casing elements 16 , 18 . The casing 12 can also include a bottom casing element 20 . In one embodiment, the bottom casing element 20 can include a stool member 22 and an apron member 24 . In the illustrated embodiment, stool member 22 has a rectangular cross section and extends perpendicularly from the wall surface towards the interior of the home or building. Also in the illustrated embodiment, apron member 24 has a rectangular cross section and is situated beneath stool member 22 such that it lies flat, parallel to the interior wall surface. In one embodiment, the apron member 24 can have mitered or profiled ends or returns. In an exemplary embodiment, the pre-fabricated casing 12 can be of a generally rectangular shape, however in other embodiments it can take other shapes including, but not limited to, circular, hexagonal, half-moon, or oval. A plurality of extension jambs 26 can be joined to the casing 12 and can extend perpendicularly thereto. The extension jambs 26 can be attached to the casing 12 using a variety of known fasteners, including nails, screws, staples, or glue. In the illustrated embodiment, once joined together, the casing 12 and the extension jambs 26 form a generally L-shaped cross section.
[0027] As depicted in FIG. 2 , the interior window trim assembly 10 can be installed around a window frame assembly 28 . In the illustrated embodiment, pre-fabricated casing 12 surrounds window frame assembly 28 and provides an aesthetically appealing finish treatment for the interior of the home or building.
[0028] In an exemplary embodiment, the components of the interior window trim assembly described herein can be custom sized at the factory or some other off-site location, either before being purchased or before being delivered to the user. As an example, extension jambs 26 can be custom sized at the factory to a variety of depths such that the desired spacing between the window frame assembly 28 and the casing 12 can be achieved. In one embodiment, the interior window trim assembly 10 can be custom sized at the factory to fit a variety of popular window sizes and shapes. In other embodiments, the casing 12 can be available in a number of different styles, for example Colonial and Windsor styles. The interior window trim assembly 10 can be constructed from wood in the preferred embodiment, however it can also be made from plastic, vinyl, aluminum, or other suitable material or materials in other embodiments.
[0029] The casing 12 and extension jambs 26 can be pre-fabricated and pre-assembled so that, once delivered to a work site, a quick and simple installation can be performed. Further, the interior window trim assembly 10 can be pre-finished either on-site or off-site. Additional finish work can be performed off-site, such as sanding, cleaning, priming, staining, or painting the interior window trim assembly 10 . This serves to further reduce the time and skill required to finish a window using the interior window trim assembly described herein. In one embodiment, the interior window trim assembly 10 can be shrink-wrapped using a high-grade film or other durable packaging so as to protect the interior window trim assembly 10 from water, dirt, dust, and handling damage during transport from the factory to the job site.
[0030] FIG. 3A shows a cross sectional view from above of an un-finished window installation in a building wall 30 . Building wall 30 has an interior surface 36 and an exterior surface 38 . These surfaces can be constructed from drywall, plaster, brick, wood, aluminum, vinyl, stone, or other material. Window framing members 32 define a rough window opening 33 . A window frame assembly 28 can be mounted in the rough window opening 33 by methods known in the art. In the illustrated embodiment, the window frame assembly 28 contains channels 34 . The interior surface 36 of building wall 30 can have rough edges 40 and 42 where it meets the rough window opening 33 . Further, without some kind of finish treatment, framing member surfaces 44 and 46 can be exposed.
[0031] FIG. 3B shows a cross sectional view of the same building wall 30 , this time with the interior window trim assembly described herein installed. Extension jambs 26 can provide a finished appearance for the previously exposed framing member surfaces 44 and 46 . Likewise, the casing 12 can cover the unfinished edges 40 and 42 of interior wall surface 36 . As illustrated, ends 48 and 50 of the extension jambs 26 engage the channels 34 in the window frame assembly 28 . A plurality of nails 52 can be used to affix the casing 12 to the interior wall surface 36 or the window framing members 32 . Screws, staples, double-sided adhesive members, or other means of fastening can also be employed for this purpose. In other embodiments, the interior window trim assembly 10 can be fastened to the window frame assembly 28 , or can be fastened both to the window frame assembly 28 and the window framing members 32 .
[0032] The casing elements of the interior window trim assembly described herein can be mated to each other in a variety of different ways. In an exemplary embodiment, a mitered, mortise and tenon or biscuit style joint is used wherever two casing or trim elements meet. The use of a mortise and tenon joint or biscuit style joint can provide for a stronger joint than simply gluing or otherwise mating two parallel surfaces together. In one embodiment, the casing elements are miter cut at each end to an angle between 0 and 90 degrees. In the illustrated embodiment, the side casing elements 16 and 18 and the top casing element 14 have 45 degree miter cuts at each end. The mitered ends can then be mated using a variety of different methods, for example using a biscuit or mortise and tenon style joint. One benefit of finger joint arrangements like mortise and tenon and biscuit joints is that they resist warping and bending due to moisture, heat, or cold. An additional benefit is that they help provide an expert fit and finish often desired by building and home owners. An example of a mortise and tenon joint is illustrated in FIG. 4A . A first trim element 52 can have a tenon 54 , or other male component, extending from a face 56 that can be mated to a second trim element 58 . A face 60 of the second trim element 58 can be mated with the face 56 of the first trim element 52 , and further, can contain a mortise 62 , or other female receptacle. Tenon 54 and mortise 62 are sized such that tenon 54 can be received either partially or wholly within mortise 62 . Tenon 54 can be held within mortise 62 by gluing, pinning, wedging, or other methods known in the art.
[0033] FIG. 4B illustrates an example of a biscuit joint. Two trim elements 72 and 74 can have faces 64 and 66 that can be mated to each other. Faces 64 and 66 can be machined with slots 68 and 69 . A biscuit 70 can then be sandwiched between the two trim elements 72 and 74 such that approximately half of the biscuit 70 protrudes into the slot 69 on the first trim element 72 and the other approximately half of the biscuit 70 protrudes into the slot 68 on the second trim element 74 . The biscuit 70 can be constructed of wood, plastic, or any other suitable material. The biscuit 70 can be coated with glue or other adhesive prior to assembly to secure the two trim elements 72 and 74 to each other. In one embodiment, the trim elements 14 , 16 , 18 , and 20 can be joined using biscuit joints.
[0034] FIG. 5 illustrates a front elevational view of an embodiment in which the interior window trim assembly 10 ′ has a simple picture frame configuration. In this embodiment, the bottom casing element 20 ′ is the same or similar to the top casing element 14 ′, creating a symmetrical appearance. The top casing element 14 ′ and bottom casing element 20 ′ are joined to respective ends of the side casing elements 16 ′, 18 ′ using mitered joints 76 . In exemplary embodiments, mitered joints 76 can be of a mortise and tenon or biscuit style joinery.
[0035] One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety. | The present invention is directed towards an interior window trim assembly that can engage with channels found in popularly used window frames. The window trim assembly can provide a pre-assembled, easy-to-install treatment for the jamb and casing surfaces of a window and can provide the same aesthetically and functionally desirable fit and finish as wooden trim crafted on site by expert tradesmen. | 4 |
TECHNICAL FIELD
This invention generally relates to ladders, and, more particularly to ladder attachments for positioning the ladder away from the work surface, and for increasing the effective width of the ladder to prevent the ladder from resting on doors or windows.
BACKGROUND OF THE INVENTION
A ladder is used to help people reach places they would not ordinarily be able to reach. Ladders are often used to climb onto roofs of buildings and are used when washing window or painting. In normal use, the bottom portion of the ladder rests on the ground or other surface, and the top end of the ladder typically leans against the building or work surface. The ladder is oriented at an angle which makes it easy for a user to climb up and down the ladder, and also aids in keeping the ladder from slipping.
One problem with ladders, especially when painting or cleaning the exterior of a house, is that there is an amount of lateral instability because the ladder rests on the side of the house with the only contact with the house being a small portion of the siderails of the ladder. When a person on the ladder reaches outside the rails, one rail will sometimes disengage the work surface, or both rails may slide along the work surface, creating an unstable condition. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that has lateral stability under normal working conditions.
Another problem with typical ladders is that the siderails of the ladder rest on the work surface with a very small contact area which sometimes dents, scrapes or bruises the work surface. It is desirable to have a ladder that contacts the work surface with a broad surface area that does not dent, scrape or mar the work surface.
Another difficulty with ladders is that their width is very narrow when compared to their length which increase the probability of lateral instability. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that has a large lateral dimension too improve lateral stability.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, an attachment for a ladder having first and second siderails, comprises an elongated bar having first and second end portions and a middle portion extending between the end portions with the first and second end portions angularly extending from the middle portion. A first resilient pad is pivotally connected to the first end portion of the bar. A second resilient pad is pivotally connected to the second end portion of the bar.
According to another aspect of the present invention an attachment for a ladder having first and second siderails comprises a first member having a rail portion and an end portion angularly extending from the rail portion, a second member having a rail portion and an end portion angularly extending from the rail portion, and a third member extending between said first and second members. The first and second members engage the third member and are slidably moveable relative to the third member and to one another to vary the distance between said end portions of the first and second members. The third member is attached to the siderails of the ladder.
It is an object of the present invention to provide ladder which effectively increases the lateral dimension of the ladder to improve lateral stability of the ladder.
Another object of the invention is to provide an attachment for a ladder to improve the lateral stability of the ladder.
Another object of the invention is to provide a ladder attachment that is adjustable to span various width of a work surface.
Still another object of the invention is to provide a non-slip gripping portion for a ladder that grips the work surface without damaging the work surface.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a preferred embodiment of a ladder with a stand-off brace attached in accordance with the present invention, and illustrating the adjustability of the stand-off brace.
FIG. 2 is a somewhat enlarged, partial diagrammatic view of a stand-off brace similar to the stand-off brace of FIG. 1, but illustrating another embodiment.
FIG. 3 is a diagrammatic view similar to FIG. 2, but illustrating another embodiment.
FIG. 4 is diagrammatic view of the stand-off brace similar to FIG. 2, but illustrating another embodiment.
FIG. 5 is a diagrammatic view similar to FIG. 3, but illustrating another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a ladder 10 has first and second siderails 12, 14, and a plurality of rungs 16, including a top rung 18, extending at spaced intervals between the siderails 12, 14. In the ladder 10, the length of the rungs 14, 18 is fixed and thereby fixes the width of the ladder 10. The width of the ladder 10 typically ranges from about ten to about twenty inches, while the length ranges from about ten to about forty feet or more. Thus, the ladder 10 is very long compared to its width.
A stand-off brace 20 is attached to the ladder 10. The stand-off brace 20 is preferably constructed of hollow aluminum or steel, or other strong, durable material, and conveniently has a round or rectangular cross section. The stand-off brace 20 includes a first member 22 that has a rail portion 24 and an end portion 26 angularly extending from the rail portion 24. Preferably, the end portion 26 extends from the rail portion 24 at a right angle. The transition from the rail portion 24 to the end portion 26 may be an abrupt angular change, or, more preferably, may be a curved transition. The rail portion 24 may have one or a plurality of holes 28 therein. The end portion 26 preferably includes means, such as a narrow section with a bore 30, for pivotally connecting a resilient pad assembly 32. Such a resilient pad assembly is described in detail in U.S. Pat. No. 4,754,842, which issued to the present inventor on Jul. 5, 1988, and is incorporated herein by reference.
The stand-off brace 20 includes a second member 34 that has a rail portion 36 and an end portion 38 angularly extending from the rail portion 36. Preferably, the end portion 38 extends from the rail portion 36 at a right angle. The transition from the rail portion 36 to the end portion 38 may be an abrupt angular change, or, more preferably, may be a curved transition. The rail portion 36 may have one or a plurality of holes 40 therein. The end portion 38 preferably includes means, such as a narrow section with a bore 42, for pivotally connecting a resilient pad assembly 44.
The stand-off brace 20 includes a third member 46 that has a plurality of openings 48. The third member 46 is connected to the siderails 12, 14 of the ladder 10 by attaching means, such as U-bolts 50, 52. Preferably, the third member 46 is attached to the rails 12, 14 by the U-bolts 50, 52 in the vicinity of the top rung 18 of the ladder 10. By this construction, the third member 46 may remain attached to the ladder 10 without interfering with the operation of the ladder 10 in the case of an extension ladder 10 wherein attachments sometimes interfere with extension and retraction.
Still referring to FIG. 1, the first member 22 fits into one end of the third member 46 and is slidably movable therein between a first position at which the resilient pad 32 is spaced a first, preselected maximum distance from the first siderail 12, and a second position at which the resilient pad 32 is spaced a second, preselected minimum distance from the first siderail 12 (shown in phantom in FIG. 1). The first is member 22 is fixed in position relative to the third member 46 by aligning openings 28, 48 and inserting a bolt or pin 54 therein.
Similarly, the second member 34 fits into the other end of the third member 46 and is slidably movable therein between a first position at which the resilient pad 44 is spaced a first, preselected maximum distance from the second siderail 14, and a second position at which the resilient pad 44 is spaced a second, preselected minimum distance from the second siderail 14 (shown in phantom in FIG. 1). The second is member 34 is fixed in position relative to the third member 46 by aligning openings 40, 48 and inserting a bolt or pin 56 therein.
Preferably, the brace 20 is adjusted so that the first resilient pad 32 is spaced from the first siderail 12 the same distance that the second resilient pad 44 is spaced from the second siderail 14. This equal spacing of the pad 32, 44 from the siderails 12, 14 maintains the symmetry of the ladder 10 and, more importantly, improves lateral stability of the ladder 10. The first and second members 22, 34 may be removed from the third member 46 for transport or storage.
Referring to FIG. 2, another embodiment of the stand-off brace 20' is illustrated wherein the first member 22' has a rail portion 24' and an end portion 26'. The end portion 26' has an opening 58 near its distal end. A plug 60 also has an opening 62 and is slidable into the distal end of the end portion 26' so that the openings 58, 62 are aligned. A bolt or pin may be inserted through the aligned openings 58, 62 to secure the end plug 63 to the end portion 26'. The end plug 60 has a reduced cross section portion 62 for pivotally connecting to a resilient pad assembly. The end plug 60 may be solid or hollow. Also, the end plug 60 may have a very short length to operate merely as a plug and attachment and connecting means for the resilient pad. Alternatively, the end plug 60 may be longer to act as an extension to farther stand off the brace 20' from the work surface. Further, the end plug 60 may be used in conjunction with an extension arm 64 (FIG. 3) wherein one end of the extension arm 64 fits into the distal end of the end portion 26', and the plug 60 then fits into the other end of the extension arm 64.
Referring to FIG. 4, another embodiment of the stand-off brace 20" is illustrated wherein the second member 34' has a rail portion 36' and an end portion 38'. The end portion 38' preferably has an opening 66 near its distal end. A cap 68 also has an opening 70 and is slidable over the distal end of the end portion 38' so that the openings 66, 70 are aligned. A bolt or pin may be inserted through the aligned openings 66, 70 to secure the end cap 68 to the end portion 38'. The end cap 68 has a reduced cross section portion 72 for pivotally connecting to a resilient pad assembly. The end cap 68 may have a very short length to operate merely as a cap and attachment and connecting means for the resilient pad. Alternatively, the end cap 68 may be longer to act as an extension to farther stand off the brace 20" from the work surface. The end cap 68 may be primarily hollow with internal shoulders, or may be primarily solid with hollow portions. Further, the end cap 68 may be used in conjunction with an extension arm 72 (FIG. 5) wherein one end of the extension arm 72 fits over the distal end of the end portion 38', and the cap 68 then fits over the other end of the extension arm 72.
While operation of the present invention is believed to be apparent from the foregoing description, a few words will be added for emphasis. The third member 46 of the brace 20 is attached to the ladder 10 with the U-bolts 50, 52. The pads 32, 44 are attached to the first and second members 22, 34 which are then inserted into the third member 46. The distance between the pad 32, 44 is adjusted by aligning the holes 28, 40, 48 at the width desired and fixing the position with the pins 54, 56. It is anticipated that the width will be adjusted from time to time which is handy when painting or washing windows. While extending the width to the maximum and leaving it there permanently is good for ladder stability, it is easier to handle a ladder with lesser widths. Extensions 64, 74 may be used to increase the distance the ladder stands away from the work surface.
It will be now appreciated that there has been presented a an attachment for a ladder to improve the lateral stability of the ladder. The ladder attachment is adjustable to span various widths of a work surface. The ladder attachment effectively increases the lateral dimension of the ladder to improve lateral stability of the ladder under all conditions. The ladder contacts the work surface with a broad surface area that does not dent, scrape or mar the work surface. A non-slip gripping portion of a ladder attachment engages the work surface without damaging the work surface.
While the invention has been described with particular reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiment without departing from invention. For example, the brace may consist of two members instead of three with one member slidably engaging the other member. In addition, many modifications may be made to adapt a particular situation and material to a teaching of the invention without departing from the essential teachings of the present invention.
As is evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the examples illustrated, and it is therefore contemplated that other modifications and applications will occur to those skilled the art. For example, the brace may be attached to the bottom portion of the ladder as well as the top portion. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and scope of the invention. | A stand-off brace for attachment to the top end of a ladder maintains the top end of the ladder away from the work surface against which it would ordinarily rest. The brace has a general U-shape wherein the legs are adjustable to vary the distance between the ladder and the work surface. The distance between the legs is also adjustable so that the brace spans the work surface. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for establishing humidity gradients within a single-zone air conditioned space. More particularly, the present invention relates to a method and apparatus for modulating humidity across large single-zone air conditioned spaces such as those typically found in supermarkets.
Supermarkets are highly intensive energy operations. Energy cost represents a significant share of overall operating cost, often equalling a store's annual profit. The largest share of supermarket energy cost is for refrigeration. Display cases refrigerated 24 hours a day typically account for more than half the electricity used in the store. Excess humidity causes the refrigeration system to consume more energy. Optimum dehumidification can help the efficiency of the refrigeration system and reduce the associated energy cost. In most commercial HVAC applications, the primary function of an air conditioning system is temperature control. In supermarkets, however, the emphasis is on dehumidification, because reducing the amount of moisture in the air causes the refrigeration system to operate more efficiently.
Once a lower humidity level is achieved in the supermarket, a number of operational benefits are simultaneously achieved. First, the energy expended by the refrigeration cases in removing moisture from the air is reduced. Second, the buildup of frost on the refrigeration coils is reduced, thereby reducing the insulating effect of frost on the coils and allowing the coils to be defrosted less frequently. Third, the need for anti-sweat heating of display case doors and other surfaces is reduced. In addition to reduced energy use for the anti-sweat heaters themselves, the load on the refrigerating coil is also reduced because less heat is transferred from the anti-sweat heaters into the display case.
An air conditioning zone is a space enclosed or separated from other spaces or environments. Traditionally, air conditioned zones are bounded by fixed walls or other physical separations. Such zones may also be bounded by flexible membrane barriers or high velocity streams of air known as "air curtains." System designers have heretofore recognized that temperature gradients, caused by internal heat generating sources such as lights, electrical equipment or refrigeration devices, may develop within such zones. Typically, the refrigeration cases in a supermarket are located some distance from the fresh produce section of the sales area. The ambient temperature in the area immediately surrounding the refrigeration cases is usually lower than the temperature in the other areas of the store and is often below a customer's comfort level. In the remainder of the store, temperature levels are generally acceptable, with the exception of the checkout area. Temperatures rise in the checkout area because windows, entryways, and concentrations of customers and employees are typically located there. It is also generally recognized that temperature gradients may result from vertical stratification of warmer air. To counteract these gradients and achieve temperature uniformity, return ducts located near the heat generating source and air circulation equipment such as ceiling fans are typically employed.
In contrast to temperature gradients, it is generally believed that significant humidity gradients do not and can not exist within a single zone. This belief rests in part on the rate with which moisture diffusion is thought to occur within such zones. As a result of this belief, the space conditioning control strategy recommended in professional literature specifies that large single zones such as supermarkets should be treated as a single entity, wherein fixed set points for temperature and humidity are maintained throughout the space. These set points are almost uniformly specified as 75° F. dry bulb temperature and 55% relative humidity. The operating condition defined by these set points is so well accepted by design and operating personnel in the supermarket industry that all equipment designed for the conditioned space (sales area) is rated at that operating condition. In fact, capacity and power consumption values for refrigerated cases are not published for other operating conditions. Moreover, since conventional air conditioning systems are intended primarily for temperature control, they produce relative humidities approximating the 55% level typically employed in supermarket applications. Such systems are not designed to produce lower humidity levels.
Because of the increased cost of electric power and the concern for the availability of electric power in the future, system designers and engineers have investigated the advantages of other set points. In applications such as supermarkets, wherein refrigeration cases are located within the conditioned space, significant power savings can be realized from the operation of the refrigeration cases if the ambient humidity is lessened to 30%. As explained above, this power savings results from, inter alia, the fact that it takes a refrigeration case less energy to cool dryer air, the latent load of such air having been reduced by the lower ambient humidity. Unfortunately, in the supermarket application, a lower overall humidity level within the conditioned space is unacceptable, because lower humidity levels have an adverse effect on fresh produce. Where the humidity is too low, vegetables begin wilt--requiring spraying, which acts to raise the humidity again. This condition forces system designers to opt for an overall ambient humidity level of 55%--which is not optimal for the operation of the refrigeration cases.
When conventional electric systems have been employed to control humidity in supermarkets, their performance has been less than satisfactory. When the system is operated long enough to achieve the desired 55% relative humidity level, the air in some or all of the store often becomes too cool, thus requiring heating to achieve a comfortable ambient temperature level. Several technologies, including gas fired desiccant systems and high-efficiency air conditioning systems, have been adapted and developed to help supermarket owners efficiently achieve the desired 55% relative humidity level.
Gas fired desiccant systems, which were originally developed for sensitive product shipping and warehousing applications, remove moisture from the air to achieve a lower humidity level. In recent years, this technology has been combined with conventional electric air conditioning systems for use in supermarkets. In such systems, the desiccant system first acts to dehumidify return air from the zone. Since the desiccant system also works to warm air passing through, this added heat must next be removed by electric air conditioning before the air can be passed back into the zone. The heat added by the desiccant equipment represents an additional load for the electric air conditioning system in addition to the space cooling load.
High efficiency electric air conditioning technologies cool return air to lower temperatures--approximately 40° to 45° F.--in order to remove moisture. In these systems, only a percentage of the return is cooled. More particularly, enough of the return air is cooled to achieve the required low humidity level. The remainder of the return air is allowed to bypass the cooling coil, thereby minimizing overcooling and the need to reheat the conditioned air for its return to the store.
Different air flow techniques have also been employed in connection with these new technologies to further improve system performance. In a supermarket, much of the air returning the air conditioning system from within the store may already be cool as well as low in humidity. For example, to avoid uncomfortably cold aisles, the cold, dry air escaping from refrigeration display cases is typically captured by returns under the cases and returned to the air conditioning unit. In comparison with outside air, air returned from elsewhere in the store is also relatively cool and dry. Although such air does not require significant processing, conventional air conditioning systems channel it through the cooling and dehumidification process just as if it were warm and humid air taken from outside the store.
Modern airflow techniques address these inefficiencies by channelling return air so as to bypass the cooling and dehumidification units. One such channelling technique--known as a single path system--is shown in FIG. 1. ##STR1## In such a system, the cooling unit can be sized for the smaller volume of air which will actually pass through the unit. After that air is cooled to the low temperature needed to reach the desired humidity, it is mixed with the bypassed air. This blend is typically cooler than the conditioned air normally delivered by conventional air conditioning systems, so less of it is needed to achieved the desired store temperature (75° F.) and humidity (55%).
An alternative air channelling technique--known as dual path channelling--is shown in FIG. 2. ##STR2## In the dual path system, the air is processed in two separate streams, with the outdoor air directed to a primary coil and the relatively cool and dry return air being cooled by a secondary coil only when necessary. Both the single and dual path systems allow system designers to employ smaller cooling units and circulation fans, thereby effecting significant energy savings. Other system enhancements which have been added to improve performance in the supermarket industry include heat pipe exchange and ice storage systems.
All of the above techniques share the common goal of maintaining a uniform temperature (75° F.) and humidity (55%) throughout the air conditioned zone. Although significant energy savings could result if the ambient humidity in the area around the refrigeration cases was lowered to 45%, no system to date has attempted to capitalize on this fact because an overall lower humidity level throughout the store is undesirable for certain goods such as fresh produce.
SUMMARY OF THE INVENTION
By creating a humidity gradient across a conditioned space, the present invention achieves varied humidity levels within a single conditioned zone. In the supermarket application, this gradient places less humid air in the area surrounding the refrigeration cases. The humidity level in the zone increases as one moves away from the refrigeration cases and towards the fresh produce or other sections. This operating condition results in significant power savings in the operation of the refrigeration cases, while maintaining a humidity level in the fresh produce section which is acceptable for the storing of such goods. In addition, the present invention works to reduce the overall level of air circulation within the zone, thereby reducing the power typically consumed by the air circulation fans.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a conventional air conditioning unit showing a return air channeling technique.
FIG. 2 is a schematic of a second conventional air conditioning unit which uses dual path channeling.
FIG. 3 shows the layout of a supermarket of the prior art.
FIG. 4 shows the layout of a supermarket arranged according to the present invention.
FIG. 5 is an energy consumption chart for refrigeration cases based on the supply air dew point.
FIG. 6 shows the layout of a supermarket arranged according to an alternate embodiment of the present invention.
FIG. 7 shows a further alternative supermarket layout arranged according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In applying the present invention to an existing supermarket, the existing air conditioning equipment can be retained, however, the supply and return ducts to the area of the refrigeration cases should be disconnected from the existing equipment. A desiccant dehumidification unit, such as that described in Munters, U.S. Pat. No. 3,125,157 should then be installed to supply the area of the refrigeration cases. The disclosure of Munters is incorporated herein by reference.
The desiccant unit supplies dry air to the area of the refrigeration cases, thereby improving the energy efficiency of the refrigeration cases. The dry air supplied by the desiccant unit is also warmer than the return air, thereby increasing the temperature and customer comfort level within the area of the refrigeration cases. When the desiccant system is used as described in the present invention, a temperature set point of 75° F. can be achieved in both the refrigerated and non-refrigerated areas of the conditioned zone. In addition, a humidity set point of 30% relative humidity can be achieved in the refrigerated area, while a 55% relative humidity is maintained in other areas of the zone or store.
Referring now to the figures, FIG. 3 shows the layout and load distribution of a typical supermarket of the prior art. Produce is typically located in area 11 and refrigeration cases are typically found in area 12, so as to be positioned on opposite ends of zone 10. Checkout area 13 is located in the front of zone 10. The load of zone 10 is distributed between air conditioning units 14 and 15. Supply air is injected into the front of zone 10 (checkout area 13) through supply ducts 17 and 17a, and return air is withdrawn from the back of zone 10 by return ducts 18 and 18a, thereby creating an air flow directed from the front to the back of zone 10. Unit 14 is typically connected to ducts 17 and 18, and unit 15 to ducts 17a and 18a. Alternatively, units 14 and 15 may share common supply and return paths. In a 20,000 square foot store, units 14 and 15 would each typically be a 40 ton unit having the capacity to move 24,000 CFM of air.
FIG. 4 shows the layout and load distribution of a supermarket designed in accordance with the present invention. Produce area 21 and refrigeration area 22 are located on opposite ends of zone 20, and checkout area 13 is located in the front of zone 20. The layout of the zone 20 is divided into a refrigeration space 24 and a non-refrigeration space 25. The load of zone 20 is distributed between desiccant unit 26 and air conditioning unit 27. Desiccant unit 26 draws its return air from and injects its supply air into refrigeration space 24; air conditioning unit 27 draws its return air from and injects its supply air into non-refrigerated space 25. Units 26 and 27 are connected to their respective spaces through conventional return and supply ducts located within the respective zones. More specifically, desiccant unit 26 draws return air from ducts 26a, and injects supply air through ducts 26b. Similarly, air conditioning unit 27 draws return air from ducts 27a, and injects supply air through ducts 27b.
Supply ducts 26b can descend from the ceiling in the center of a shopping aisle and, in aisles containing open (or coffin) refrigeration cases, these ducts will preferably direct the supply air parallel to the direction of the shopping aisle. In aisles containing closed door refrigeration cases, the supply air is preferably directed at the cases (or perpendicular to the direction of the aisle). Desiccant unit 26 is controlled by thermostat 26c and humidistat 26d, while air conditioning unit 27 is controlled by thermostat 27c and humidistat 27d. Both thermostats will typically be set at 75° F., humidistat 26d can then be set to achieve a 45% relative humidity (or lower) in refrigeration space 24, and humidistat 27d can be set to achieve a 55% relative humidity in non-refrigerated space 25. A Honeywell model T42 thermostat, or any other suitable model, can be used for thermostats 26c and 27c, and a Honeywell model H609A dew-point controller, or any other suitable model, can be used for humidistats 26d and 27d.
When the arrangement shown in FIG. 4 was applied to a supermarket with a sales area of approximately 20,000 square feet, wherein desiccant unit 26 was rated at 150 lbs./hour having the capacity to move 8,000 CFM of air, and air conditioning unit 27 was a 40 ton unit having the capacity to move 24,000 CEF of air, a 75° F. temperature level was generally created throughout the zone and a humidity gradient ranging from 45% to 55% relative humidity was targeted and achieved across zone 20. Dew points as low as -20° F. were also achieved in air supplied by desiccant unit 26. In addition, the energy needed for air circulation within the zone was substantially reduced.
Because the system of the present invention is capable of delivering supply air with dew points of from 40° F. to -20° F. and below, the system may be controlled to optimize the cost-efficiency of operation. Typically, heat used in regeneration of a desiccant wheel is derived from one or more of three sources: air conditioning condenser strip heat, desiccant wheel waste heat (transferred through a counter-flowing heat exchange medium such as a heat exchanger wheel), and supplementary heat derived from gas combustion or electrical resistance. The marginal energy cost of supplying air having less moisture content is the sum of all of the energy used over and above the available heat derived from normal operation of the HVAC systems.
The system of the present invention may be optimally controlled by calculating the marginal energy cost required to achieve a preselected level of dehumidification, and comparing that marginal cost against the calculated savings to be derived from lowering the moisture content of the supply air. For example, it is known that for every 1° F. reduction in dew point, a 1% reduction in energy consumption of refrigeration equipment (air conditioners, freezer cases, refrigerated cases, and the like) is achieved. This relationship holds true down to dew points near the refrigerant temperature of a given piece of refrigeration equipment.
Similarly, glass-front refrigerated cases typically use resistive heaters in their doors to prevent condensation. Such heaters (anti-sweat heaters) are activated when the surrounding air is above approximately 40° F. dew point, and each door heater typically consumes 250 W of electrical energy. In addition, each heater reflects approximately 200 W of additional load into the refrigerated case, for a total load of approximately 0.5 KW per door. The energy savings which may be realized by deactivation of the door heaters stands in addition to the linear energy savings (1° F. reduction in dew point=1% reduction in energy consumption) which holds for refrigeration equipment described above.
Other points of criticality may be factored into the dew point optimization calculation. For example, when the ambient dew point passes below the surface temperature of goods stored in open refrigerated cases, elimination of surface condensation on the goods is achieved, thereby reducing the latent (and therefore overall) load on the refrigeration system. Typically, supermarkets have separate open refrigeration cases for both medium temperature and frozen goods. In the 75° F. environment of most supermarkets, condensation is eliminated in the medium temperature cases when the dew point passes below 36° F., and in the frozen cases when the dew point passes below 5° F.
In addition, as the dew point is reduced towards the surface temperature of the cooling coils in the refrigeration cases, icing on the coils is reduced thereby reducing the frequency with which defrost cycles must be undertaken. In fact, in medium temperature cases the need for defrosting is totally eliminated when the dew point passes below 20° F., and the need for defrosting in frozen cases is eliminated below a dew point of -20° F. Since defrost cycling consumes energy, significant energy savings can be achieved by eliminating or reducing the need for defrosting. Moreover, since defrost cycles typically have a negative effect of many refrigerated goods, i.e. water contained in ice cream typically crystalizes as a result of defrost cycling, a lower ambient dew point may have the corollary benefit of improving shelf life. A graphical illustration of the overall energy consumed by the refrigeration cases versus ambient dew point is shown below:
As shown above, while some of the energy savings available are threshold events (such as deactivation of door heaters), others are both threshold and proportional (such as lengthening the interval between defrost cycles, and the complete elimination of the need for such cycles), and others are strictly proportional (such as the increase in cooling efficiency of air conditioners with decreasing moisture content of the air to be cooled). Thus, for any predetermined adjustment in ambient air dew point, the cost to achieve the target dew point must be measured against the savings from the sum of these effects.
FIG. 6 shows the layout of a supermarket arranged according to an alternate embodiment of the present invention. In this arrangement, checkout area 13 is located in the front of the zone, however, it does not extend into the refrigeration space 24. In this embodiment, cool air from other parts of non-refrigeration space 25 is redistributed within that space to checkout area 13. This redistribution may be accomplished through conventional duct work or other known means. In the embodiment shown, this redistribution is accomplished by redistribution fan 31, which acts to withdraw cool air through duct 32 and inject it back into non-refrigerated space 25 through duct 33. This embodiment is designed to counteract the higher temperature levels which typically occur within the checkout area.
Referring now to FIG. 7, there is shown a further alternative supermarket layout arranged according to the present invention. In this embodiment, refrigeration space 41 is located within the center of zone 40, with non-refrigeration space 42 surrounding refrigeration space 41. Non-refrigeration space 42 is subdivided into non-refrigerated regions 42a, 42b, 42c, 42d, 42e, 42f, 42g, 42h and 42i. In a typical supermarket, subregions 42a and 42b might contain produce, subregions 42c, 42d, 42e, 42f and 42g might represent the checkout and vestibule areas, and subregions 42h and 42i might contain general merchandise. Refrigeration space 41 is serviced by desiccant unit 43. Non-refrigeration space 42 is serviced by individual air conditioning units 44a, 44b, 44c, 44d, 44e, 44f, 44g, 44h and 44i, located within corresponding subregions 42a, 42b, 42c, 42d, 42e, 42f, 42g, 42h and 42i. Desiccant unit 43 and air conditioning units 44a-i are each controlled by a conventional thermostat and humidistat. Each of the air conditioning units have return and supply ducts (not shown) which connect the intake and output of each air conditioning unit to its respective zone.
When the arrangement shown in FIG. 7 was applied to a supermarket with a sales area of approximately 20,000 square feet, wherein desiccant unit 43 was rated at 150 lbs./hour having the capacity to move 8,000 CFM of air, and air conditioning units 44a-i were each 8 ton units having the capacity to move 4,400 CFM of air, a 75° F. temperature level was generally created throughout the zone. Moreover, a relative humidity of 45% was achieved in refrigeration space 41, while non-refrigerated space 42 remained generally at a 55% relative humidity. In this embodiment, the energy needed for air circulation within the zone was again substantially reduced. Moreover, given the smaller decentralized air conditioning units employed in non-refrigeration space 42, substantially less duct work was required for this system, thereby reducing its up-front cost.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes of the invention. Accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
STATEMENT OF INDUSTRIAL UTILITY
The method and system of the present invention may be useful for reducing energy consumption of refrigeration systems in commercial spaces such as supermarkets and the like. | A method for modulating humidity across large single-zone air conditioned spaces such as those typically found in supermarkets wherein conventional air conditioning means and a desiccant unit are combined to supply varying levels of humidity to different regions within the single-zone space. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the general art of electrical accessories, and to the particular field of surge protection equipment.
2. Discussion of the Related Art
Building safety is a major concern to any property owner or renter. One concern of anyone who owns or occupies a building is associated with a power surge in the electrical system. The power surge can result from lightning, fires, failures in the electrical system servicing the property, or the like.
A power surge can damage or destroy electrical equipment in the building, and can even start a fire in some cases. Furthermore, a power surge that is of sufficient magnitude may damage other equipment in the building.
Therefore, there is a need for a means for protecting a building against a power surge in the electrical system.
The art contains several examples of UPS equipment, power surge protection equipment, and the like. However, there does not appear to be any easily installed equipment that can protect an entire building.
Therefore, there is a need for an easily installed means for protecting a building against a power surge in the electrical system.
Still further, if the power surge is significant enough, there may be a fire in the utility connection box at which the building wiring is connected to the wiring associated with a utility. This could be a catastrophic event.
Therefore, there is a need for a means for protecting a building against a power surge in the electrical system as well as protecting against any fire that might be associated with the power surge.
PRINCIPAL OBJECTS OF THE INVENTION
It is a main object of the present invention to provide a means for protecting a building against a power surge in the electrical system.
It is another object of the present invention to provide an easily installed means for protecting a building against a power surge in the electrical system.
It is another object of the present invention to provide a means for protecting a building against a power surge in the electrical system as well as protecting against any fire that might be associated with the power surge.
SUMMARY OF THE INVENTION
These, and other, objects are achieved by a power surge protection unit that is installed in a building utility connection panel. The unit embodying the present invention includes elements that will alert someone if a breaker has been tripped. The unit further includes a system for dispersing a extinguishing agent in the utility box if a power surge is of sufficient magnitude.
Using the power surge protection unit embodying the present invention is easily installed and will generate an alert if a breaker is tripped and can protect the utility panel against fire.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a perspective view of a power surge protection device embodying the present invention.
FIG. 2 is a front elevational view of a utility panel to which the power surge protection device of the present invention is connected.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description and the accompanying drawings.
Referring to the Figures, it can be understood that the present invention is embodied in a power surge protection unit 10 . Unit 10 comprises a utility connection panel unit 12 , which connects a utility to a building via feed lines L. Utility connection panel unit 12 includes a housing 14 having an interior volume 16 . A panel 20 contains a plurality of circuit breaker elements, such as element 22 , which are located inside housing 14 and serve the functions usual to such elements. Utility connection panel unit 12 further includes a neutral connection element 24 and a ground connection element 26 .
Unit 10 further includes a power surge protection and indicating unit 40 . Unit 40 is mounted adjacent to utility connection panel unit 12 and includes a housing 42 , which has an interior volume 44 and a door 46 which covers and uncovers the interior volume 44 .
A neutral connection element 48 is located in the housing 42 of the power surge protection and indicating unit 40 and an electrical connection 50 electrically connects the neutral connection element 48 of the power surge protection and indicating unit 40 to the neutral connection element 24 of the utility connection panel unit 12 .
A ground connection element 60 is located in the housing 42 of the power surge protection and indicating unit 40 and an electrical connection 62 electrically connects the ground connection element 60 of the power surge protection and indicating unit 40 to the ground connection element 26 of the utility connection panel unit 12 .
A neutral circuit fuse element 70 is also located in the housing 42 of the power surge protection and indicating unit 40 . The neutral circuit fuse element 70 is connected to the neutral connection element 48 . A ground circuit fuse element 74 is located in the housing 42 of the power surge protection and indicating unit 40 . The ground circuit fuse element 74 is connected to the ground connection element 60 .
A neutral fault indicator element 80 is located on the housing 42 of the power surge protection and indicating unit 40 , and an electrical connection 82 is located between the neutral fault indicator element 80 and the neutral connection element 48 in the housing 42 of the power surge protection and indicating unit 40 . A ground fault indicator element 86 is located on the housing 42 of the power surge protection and indicating unit 40 , and an electrical connection 88 is located between the ground fault indicator element 86 and the ground connection element 60 in the housing 42 of the power surge protection and indicating unit 40 .
An extinguishing agent dispensing system 90 is located in housing 42 and includes a container 92 of extinguishing agent located in the housing 42 of the power surge protection and indicating unit 40 . Container 92 is electrically uncharged in a normal state. The extinguishing agent is similar to the extinguishing agents used in ABC fire extinguishers, compressed dry air or SF6 gas, which extinguishes arcs in high-voltage circuit breakers.
An electrical connection 94 is located in housing 42 and electrically connects the container 92 of the extinguishing agent to the neutral connection element 48 of the power surge protection and indicating unit 40 . The container 92 of extinguishing agent becomes negatively charged during a power surge.
A fluid connection conduit 100 is located between the container 92 of extinguishing agent and the interior of the housing 14 of the utility connection panel unit 12 and the interior of the housing 42 of the power surge protection and indicating unit 40 . The container 92 includes a valve 104 which permits extinguishing agent to flow out of the container 92 when the container 92 becomes negatively charged. Valve 104 is fluidically connected to fluid connection conduit 100 between the container 92 of extinguishing agent and the interior of the housing 14 of the utility connection panel unit and the interior of the housing of the power surge protection and indicating unit 40 .
During a power surge, extinguishing agent 110 is dispensed into housing 14 of utility connection panel unit 12 and the indicators 80 and/or 86 are activated.
It is understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangements of parts described and shown. | A device is easily connected to a utility panel of a building and includes signals to indicate improper operation in the electrical system of the building. The device further includes a system for dispersing an extinguishing agent into the utility panel box in the event a power surge is of sufficient magnitude. | 7 |
FIELD OF THE INVENTION
The present invention relates to a set of ribs in a dewatering device in a paper machine which supports and/or loads at least one wire in the paper machine and/or doctors water from an inner face of the at least one wire. The set of ribs comprises at least two cross-direction ribs, which are placed at a distance from one another in the machine direction, and whose height positions are adjustable. The ribs are interconnected in pairs by means of intermediate parts.
The present invention also relates to a twin-wire forming zone in a web former of a paper machine in which a material web is formed.
BACKGROUND OF THE INVENTION
In web formers in paper machines, a number of different forming members are used. The primary function of these forming members is to produce compression pressure and a pressure pulsation in the fibrous layer, i.e., the web, that is being formed in the web former. By means of the pressure and the pulsation, dewatering of the web that is being formed is promoted and, at the same time, the formation of the web is improved. The forming members include various forming shoes which are usually provided with a curved ribbed deck and over which the forming wires, placed one above the other with the web placed therebetween, curve. In the area of these forming shoes, water is drained from the web through the wire placed at the side of the outside curve by the effect of its tensioning pressure, and this draining is promoted further by a field of centrifugal force. Draining of water also takes place through the wire placed at the side of the inside curve (i.e., more proximate the forming shoe), which draining is generally intensified by means of negative pressure present in a suction chamber of the forming shoe. The ribbed deck of the forming shoe produces pressure pulsation, which both promotes the dewatering and improves the formation of the web.
Further, in the prior art, so-called MB units (loading element units) are known, through which two wires placed one against another run typically as a straight run. In the prior art MB units, pressure loading equipment is arranged inside the loop of one of the wires and draining equipment provided with a set of guide and draining ribs is arranged inside the loop of the other, opposite wire. In a manner known in the prior art, the MB unit is typically placed in the fourdrinier wire portion of a forming section so that the MB unit is preceded by a single-wire portion of considerable length, in which portion a substantial amount of dewatering takes place before the web passes through the MB unit.
In standard prior art MB formers, the lower unit, i.e., the unit in the loop of the lower wire, comprises a support board which includes loaded ribs. Each of these ribs is loaded separately by means of a loading hose of its own.
With regard to the prior art, reference is made to the current assignee's Finnish Patent No. 90,673, corresponding to U.S. Pat. No. 5,387,320 which is incorporated by reference herein, which describes a twin-wire web former of a paper machine. This former comprises a carrying wire and a covering wire which together form a twin-wire forming zone in which a forming unit is arranged. The forming unit comprises a forming board and a water drain box arranged in opposed relationship to the forming board. The water drain box comprises a number of spaced apart ribs whereby water is drained out of the web through the gaps or spaces defined between the ribs into the water drain box to a significant extent by the effect of negative pressure (vacuum) applied to these spaces. In the forming board placed facing the drainage box, there are a number of transverse or cross-direction loading ribs placed at a considerable distance from one another in the machine direction. In the area of the forming unit, the dewatering of the web can be arranged to take place both through the covering wire and through the carrying wire, as well as toward the forming board through the open gaps placed between its loading ribs. In the construction described in FI'673, it has been considered novel that successive loading ribs are interconnected at least in pairs by intermediate parts, and that the intermediate parts, together with the loading ribs attached to them, form ribbed shoes which can be loaded by means of loading hoses to produce a dewatering pressure in the web placed between the wires, while the ribs on the water drain box operate, in a manner in itself known, as back-up members for the loading forces.
In a manner known in the prior art, the ribs are fixedly interconnected, in which connection, when the first rib of a pair of ribs in the running direction of the web and the upper rib placed between the pair of ribs in the opposite wire loop remove water, the stock web becomes thinner, in which case the second rib of the pair of ribs must rise to a level higher than the first rib. It follows from this that the second rib must be loaded to a greater extent than the first rib, in which case the element is turned into an inclined position, and the tips of the ribs are separated from the wire as a result of the change in angle. It is a disadvantage that in such a case, at least one of the ribs does not remove water so that the loading pressure must be increased in order to bring the tip of the rib into contact with the wire. Owing to this employment of an unduly high loading pressure, the base of the paper can also be spoiled. Also, it is quite difficult to operate the second rib with a slight load. It has also been problematic that such ribs cannot be brought into an asynchronous movement.
One solution for these problems is described in the current assignee's Finnish Patent No. 95,058 (corresponding to U.S. Pat. No. 5,690,792, incorporated by reference herein), which describes a set of ribs in a dewatering device in a paper machine which are used to support/load the wire or wires in the paper machine and/or to doctor water from the inner face(s) of the wire or wires. The set of ribs comprises at least two cross-direction ribs placed at a distance from one another in the machine direction, and each of which has an adjustable height position. The ribs in the set of ribs are interconnected in pairs by means of intermediate parts. It has been considered a novel aspect of this set of ribs that the ribs are interconnected in pairs by means of four-joint articulation mechanisms placed at a distance from one another in the cross direction of the wire/wires. By means of these articulation mechanisms, the positions of the ribs in the horizontal direction remain substantially constant irrespective of the relative positions of height of the ribs. However, this construction is not entirely suitable for use in connection with a rib or equivalent in a dewatering device in a paper machine of the type described in Finnish Patent No. 95,935 (corresponding to U.S. Pat. No. 5,695,613, incorporated by reference herein).
Finnish Patent No. 95,935 describes a rib for a dewatering device in a paper machine which supports and/or loads at least one wire in a paper machine and/or doctors water from the face(s) of the at least one wire. The rib is loaded by means of the pressure of a medium. Between the rib and its frame part, a pressure space has been formed, which is defined by a flexible belt and into which the loading pressure is passed. The flexible belt defines the pressure space so that the area of effect of the loading force is independent from the movement of the rib.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a solution by whose means the problems of the prior art ribs in dewatering devices can be solved.
It is a particular object of the present invention to provide a solution which is suitable for use in connection with a rib as described in Finnish Patent No. 95,935 (U.S. Pat. No. 5,695,613) or in connection with a rib of similar type.
It is another object of the present invention to provide a new and improved twin-wire forming zone in a web former including a set of ribs in accordance with the invention.
In view of achieving the objects stated above and others, in a set of ribs for a dewatering device in accordance with the invention, the ribs are interconnected in pairs by means of crank mechanisms placed at a distance from one another in the cross direction of the wire/wires, in which connection the ribs can be loaded independently from one another.
In a loading element in accordance with the invention, the water drain ribs have been interconnected by means of an intermediate pin of a type of a crankshaft, in which connection the ribs can be loaded and displaced independently from one another.
According to a preferred exemplifying embodiment of the invention, when a crankshaft mechanism is used for attaching the ribs in pairs, the angles between the ribs do not change, in which case the faces of the ribs remain in the desired positions relative to the wire and the foil angle remains as desired in the case of each rib, in which connection the ribs can be made to remove water uniformly. Also, in this manner, an efficient and controlled ratio of dewatering/loading is achieved.
As further advantages of the invention, it is achieved that when ribs provided with a clearance angle are used, the clearance angle at each rib remains correct because the crankshaft mechanism prevents turning of one of the ribs into an oblique position.
The arrangement in accordance with the invention is in particular suitable for such dewatering taking place in the wire part in which it is desirable to regulate the loading of the ribs. The arrangement in accordance with the invention is also well suitable for use in projects of modernization of sets of dewatering ribs.
When the web becomes thinner as water is drained, by means of an arrangement in accordance with the invention an increased possibility of regulation of the loading rib is obtained, because each rib can be loaded separately. By means of the number of ribs employed during operation, the quality of the paper is affected, and a suitable number of ribs is selected depending on the paper stock, running speed, and on the thickness of the slice opening in the headbox.
In a general embodiment of the set of ribs which support and/or load at least one wire in the paper machine and/or doctor water from an inner face of at least one wire in accordance with the invention, the set of ribs comprises at least two cross-direction ribs spaced from one another in the machine direction and having adjustable height positions relative to the at least one wire, intermediate parts for interconnecting the at least two ribs in pairs such that at least one pair of interconnected ribs is formed, and at least two crank mechanisms for further interconnecting the ribs of each pair of interconnected ribs. The crank mechanisms are spaced from one another in the cross direction of the wire and structured and arranged to enable independent loading of each rib of each pair of interconnected ribs.
The set of ribs may comprise frame parts, each fixedly coupled to the paper machine and associated with one of the ribs, flexible belts, each coupling one of the ribs to a respective one of the frame parts such that a pressure space is defined between the rib, the frame part and the belt, and pressure loading means for applying a loading pressure into the pressure spaces to load the ribs in a direction toward the wire. In more specific embodiments, flexible belt means each couple one of the ribs to a respective one of the frame parts and each belt means comprises first and second elongate belt sections extending in the longitudinal direction of the respective one of the ribs. Each of the first and second belt sections has first and second longitudinally extending edge regions, the first longitudinally extending edge region of the first and second belt sections being connected to the respective rib and the second longitudinally extending edge region of the first and second belt sections being connected to the respective frame part. Each flexible belt means may further comprise attachment means for attaching the edge of the first longitudinally extending edge region of the first and second belt sections to the respective rib and the edge of the second longitudinally extending edge region of the first and second belt sections to the respective frame part. The attachment means comprise a fastening member having a shaped profile adapted to be fixedly retainable within a cavity of the respective rib and within a cavity of the respective frame part. The first and second belt sections are made of a resilient material such as rubber.
In another embodiment, each rib has first and second longitudinal faces, and the set of ribs further comprises elongate frame parts having first and second longitudinal faces, each fixedly coupled to the paper machine and associated with one of the ribs, and flexible belt means, each coupling one of the ribs to a respective one of the frame parts such that a pressure space is defined between the rib, the frame part and the belt means. Each of the belt means comprises first and second elongate belt sections extending in the longitudinal direction of a respective one of the ribs. Each of the first and second belt sections has first and second longitudinally extending edge regions, the first belt section being attached at the first longitudinally extending edge region to the first longitudinal face of the respective rib and at the second longitudinally extending edge region to the first longitudinal face of the respective frame part and the second elongate belt section being attached at the first longitudinally extending edge region to the second longitudinal face of the rib and at the second longitudinally extending edge region to the second longitudinal face of the frame part. Pressure loading means apply a loading pressure into the pressure spaces to load the ribs in a direction toward the wire.
The twin-wire forming zone in a web former in accordance with the invention comprises means for guiding a first wire in a loop, means for guiding a second wire in a loop such that at least a portion of the second wire runs together with the first wire to thereby define the twin-wire forming zone, a water drain box arranged in the loop of the first wire and comprising loading ribs for loading the first wire, and a set of ribs arranged in the loop of the second wire in opposed relationship to the water drain box such that one of the ribs of the water drain box is arranged in opposed relationship to a gap defined between an adjacent pair of the ribs of the set of ribs. The set of ribs comprises at least two cross-direction ribs spaced from one another in the machine direction and having adjustable height positions relative to the at least one wire, intermediate parts for interconnecting the at least two ribs in pairs such that at least one pair of interconnected ribs is formed, and at least two crank mechanisms for further interconnecting the ribs of each of the at least one pair of interconnected ribs. The at least two crank mechanisms are spaced from one another in the cross direction of the wire and structured and arranged to enable independent loading of each of the ribs of each of the at least one pair of interconnected ribs. The set of ribs and crank mechanism in the twin-wire zone may include all of the features described herein.
In the following, the invention will be described in more detail with reference to the figures in the accompanying drawings. However, the invention is not strictly confined to the details of the illustrated embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects of the invention will be apparent from the following description of the preferred embodiment thereof taken in conjunction with the accompanying non-limiting drawings, in which:
FIG. 1 is a schematic illustration of an exemplifying embodiment of an environment of application of the invention;
FIGS. 2A and 2B are schematic illustrations of a loading element in accordance with the invention in a loading position; and
FIGS. 3A and 3B are schematic illustrations of a loading element in accordance with the invention in a non-loaded position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-3B wherein like reference numerals refer to the same or similar elements, FIG. 1 is a schematic illustration of an environment of application of the present invention which includes a former comprising a lower wire 10 arranged to run in a loop and an upper wire 20 arranged to run in a loop. In connection with the loop of the lower wire 10, after the headbox (not shown), there is the single-wire initial portion 10a of the web forming zone in which draining elements 11a are placed and operated to dewater the stock web until the stock web W 0 attains a certain dry solids content, and at least its lower face receives a certain couching degree before the web enters into a subsequent twin-wire zone which is formed between the wires 10 and 20. The twin-wire zone starts at a breast roll 21 arranged in the loop of the upper wire 20. After the breast roll 21, the twin-wire zone includes a forming shoe 12 arranged inside the loop of the lower wire 10 and a loading unit 32 of an MB unit 30 arranged after the forming shoe 12 in the traveling or running direction of the wires 10,20. In the loading unit 32, there are loading ribs which are arranged one after the other in the machine direction, i.e., sequentially arranged and extend across substantially the entire width of the wires 10,20. At least some of the loading ribs in the loading unit 32 are interconnected in pairs, although some ribs in the loading unit 32 may also be individual ribs or connected in units of more than two.
The upper wire 20 is arranged to run over several turning/reversing rolls 16, 17, 18 and over the breast roll 21 and the lower wire 10 is arranged to run substantially parallel to the upper wire 20 underneath the upper wire 20 in the twin-wire zone. The wires 10 and 20 form a wedge-shaped inlet gap K in which the web W 0 placed on the lower wire 10 is pressed continuously between the wires 10 and 20 as the wires make progress in the direction of travel of the wires 10,20. After the wedge-shaped inlet gap K, in a transfer direction F, there is the MB unit 30 which comprises an upper dewatering or water drain box 51 and the loading units 32. The bottom of the water drain box 51 comprises ribs 52 and water is sucked or drawn out of the web W 0 through gaps or spaces defined between the ribs 52 into the dewatering box 51 by means of a vacuum and air. On its run, the upper wire 20 rests against the ribs 52. The MB unit 30 also includes the loading units 32 which permit dewatering to take place in a downward direction. On the top face of each loading unit 32, there are one or more sets of loading ribs 33. Above the sets of loading ribs 33 and inside the loop of the upper wire 20, ribs 52 are arranged to face the gaps between the ribs in the sets of loading ribs 33 and serve as backup parts for the pressure loading. Further, FIG. 1 shows a number of other parts and support structures included in the former, which parts and structures are known in themselves and will not be described in further detail in this application.
In the exemplifying embodiments shown in FIGS. 2A,2B, 3A and 3B, the set of loading ribs 33 comprises two loading ribs 41. Each loading rib 41 comprises a frame part 43 on which the loading rib 41 is supported by means of a glide rail or part 44. The loading rib 41 is arranged to move in the vertical direction while supported by the glide part 44. The planar top faces or sides of the loading ribs 41 glide against the wire 10,20 face and load the wires while water operates as a lubricant. By means of the loading ribs 41, water drained from the web W 0 is doctored off the lower face of the wire. The loading rib 41 is supported in its place of operation typically by means of a continuous glide rail 44, which is made integral with the frame part 43. Preferably, flexible belt means couple the loading rib 41 to the frame part 43 and comprise two elongate belt sections 46 extending in the direction of the loading rib 41. Each belt section 46, also referred to herein as a belt, has first and second longitudinally extending edge regions 46a,46b whereby the first longitudinally extending edge region 46a is attached to a respective one of the exterior edges or sides of the loading rib 41 and the second longitudinally extending edge region 46b is attached and to the frame part 43 at a respective side thereof so that U-shaped loops 48 are formed downwards. In other words, each first longitudinally extending edge region 46a is attached to a respective longitudinal face 41a,41b of the loading rib 41 and each second longitudinally extending edge region 46b is attached to a respective longitudinal face 43a,43b of the frame part 42. Shield plates 55 are attached to the sides of the rib 41 outside the belt 46 and restrict the movement of the belt 46 toward the sides.
In the construction shown in FIGS. 2A,2B, 3A and 3B, the loading force is produced by passing the loading pressure P a ,P b by means of a medium, for example air, into the space defined by the flexible belt 46, the rib 41, and the frame part 43. The loading pressure P a ,P b is relieved by lowering the pressure P a ,P b and the force of gravity returns the rib 41 down. The belt 46, whose thickness is, for example, from about 0.1 mm to about 3 mm, preferably from about 1 mm to about 2 mm, and which is made of rubber or any other, equivalent resilient material, is attached from its upper edge 46a to the rib 41 and from its lower edge 46b to the frame part 43 so that the U-shaped loops 48 are formed downwards, which loops permit movement of the rib 41 in a vertical direction (up and down in the illustrated embodiment). Lateral supports such as the shield plates 55 restrict the expansion of the belt 46 toward the sides, in which case the area of effect of the pressure is not changed when the rib 41 moves in the loading direction.
As shown, the ribs 41 are interconnected in pairs by means of a crank mechanism 60, and the frames 43 of the interconnected ribs are further connected by means of an intermediate part 47 attached to both ribs of the pair. More specifically, the bottom portions of the frames 43 of the rib 41 are interconnected by means of intermediate part support rods 47. The top portions of the loading ribs 41 are interconnected by means of the crank mechanism 60 which permits separate and independent loading of each rib 41, i.e., without affecting the loading of the other rib of the pair, and which further secures that the positions of the ribs 41 in relation to the web W 0 remain as desired. The crank mechanisms 60 are placed at a distance L 1 from one another in the cross direction of the machine, which distance is from about 50 mm to about 500 mm. The distance L 2 between the ribs 41 is from about 30 mm to about 300 mm.
The crank mechanism 60 comprises an arm part 61 attached to a first rib 41 of a pair of interconnected ribs and, similarly, an arm part 62 attached to the other rib 41 of the interconnected pair, and an intermediate crank arm 63, which is linked with the arm parts 61,62 by means of articulated joints 64,65. In view of the articulation of the arm parts 61,62 with respect to the crank arm 63 and the freedom of movement provided thereby, loading of one of the ribs in an interconnected pair will not significantly affect the loading of the other rib of the pair.
In the loading position shown in FIGS. 2A and 2B, the crank mechanism 60 is in the upper position, and in the stage shown in FIGS. 3A and 3B, the crank mechanism 60 is in the lower position.
In the following, the patent claims will be given, and the various details of the invention can show variation within the scope of the inventive idea defined in the claims and differ even to a considerable extent from the details stated above by way of example only. As such, the examples provided above are not meant to be exclusive and many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims. | A set of ribs in a dewatering device in a paper machine for supporting and/or loading at least one wire in the paper machine and/or doctoring water from the inner face(s) of the at least one wire. The set of ribs includes at least two cross-direction ribs placed at a distance from one another in the machine direction and whose height positions are adjustable. The ribs of the set of ribs are interconnected in pairs by intermediate parts, and by crank mechanisms placed at a distance from one another in the cross direction of the at least one wire so that the ribs are loadable independently from one another. | 3 |
RELATED APPLICATIONS
This patent application claims the benefit of priority, under 35 U.S.C. §119(e), to U.S. Provisional Application Ser. No. 61/418,508, filed Dec. 1, 2010, which is incorporated herein by reference in its entirety.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the software and data as described below and in the drawings that form a part of this document: Copyright 2009, Gracenote, Inc. All Rights Reserved.
TECHNICAL FIELD
The present disclosure relates generally to music recognition services and more specifically to using novel database indexing methods to store and retrieve information associated with music recognition.
BACKGROUND
Standard audio compact discs (“CD”) may not, and normally do not, contain any information related to the content such as artist, track, and title. The only information that is guaranteed to appear on any standard CD is the table of contents (“TOC”) which is a “header” at the beginning of each disc. The TOC marks the beginning of each track in frames which are 1/75th of a second. As such, the CD player can use this information to precisely locate the beginning of each track and to determine the precise track length. For illustrative purposes, a four track CD may contain a TOC composed as follows: [150 26570 49757 72545 94105]. “Track 1” begins at frame 150 (e.g. 2 seconds) and ends at frame 26570 (e.g. approximately 354.25 seconds). “Track 2” begins at frame 26570 and ends at 49757 . The last frame, 94105 , corresponds to the end of “Track 4” and the end of the CD program area.
Due to the precise nature of TOC frames, the likelihood of two CDs sharing the same TOC is extremely low. As such, a TOC can normally be used to uniquely identify the current CD being played. There are two methods of performing this comparison: exact matching and fuzzy matching. Exact matching requires that all frames from the inputted TOC match the frames of a reference TOC in a database. Fuzzy matching compares the inputted TOC to a subset of reference TOCs in a database and, using an algorithm, determines a correct, or closest, match. Fuzzy matching is particularly useful when exact matches cannot be found. For example, when an album has been reprinted, the TOC of this reproduced album often does not precisely match the TOC of a previously printed album.
Currently, the most common implementation of TOC lookups uses a general-purpose database engine. In many cases, high-end devices utilize a standard B-tree database. This type of database is able to meet the needs of TOC lookups (including fuzzy matches) with the principal advantage being that a general purpose engine can be dynamically updated. However, there are many disadvantages of using such a database structure due to the fixed overhead with regard to code size and performance.
As a consequence of the general-purpose indexing mechanism, a general-purpose database normally requires several disk seeks for each TOC lookup (up to thousands in some cases of fuzzy matching). This is because of the non-linear organization of database information (e.g. TOCs). A standard database normally contains separate “buckets” of information. Both exact and fuzzy matching require sifting through one of more of these buckets, and accessing each bucket requires a database access. Each database access may require a number of disk seeks and significant CPU time to traverse the index. For example, for each bucket the system must navigate through a complex indexing system to locate the address of the bucket, seek to the bucket, and finally scan through the bucket. To search a second bucket, the system must perform the same operation. This can require a substantial amount of seeks which necessitate the use of high-end hardware. On a low-end platform a fuzzy matching operation with a general-purpose indexing scheme could take up to several minutes. As such, these common databases require fast hard disk speeds, extra RAM for caching of data, and significant amounts of CPU processing time.
While this may be acceptable for a high-end hardware platform, implementing such a system and method in a low-end hardware platform would result in extremely poor performance due to limited resources (e.g. RAM and storage space) and low processing power. In many instances, the poor performance renders it unusable. Further, dynamic updates may not be required as part of a low-end solution, which suggests that the general-purpose database engine need not be utilized for TOC lookups in such cases.
In traditional indices, 20-40% of the space consumed by a B-tree index is devoted to the indexing information with the remainder being used to store the actual data itself. The overhead of a B-tree index is variable, and increases as more records are added to the index. Therefore, a variable and substantial portion of storage space is “wasted” on the indexing information rather than on the actual data. In some cases the wasted space can cost many megabytes.
SUMMARY
Example embodiment of an indexing scheme is described herein to make TOC look-ups simple and efficient enough to be employed on a low-end device e.g. a low end car CD player with no hard disk, just flash memory and a 16 bit processor that would be capable of showing basic artist, track and title information with the optional capability to show cover art. It is however to be appreciated that this disclosure is not limited to the aforementioned example embodiments
The example Static TOC indexing systems and methods described herein may allow TOC lookups in a manner which more efficiently uses resources such that it may be implemented in a low-end system with performance comparable or superior to a standard B-tree database on a high-end system. For example, the novel indexing scheme may allow a successful search with only two disk seeks as opposed to the usual hundreds of disk seeks for a more general purpose indexing mechanism. Both exact and fuzzy matching of TOCs may, for example, take 2 disk seeks. Once matches have been determined, the additional step of fetching compact disc metadata (such as album/artist/track text) requires only a single disk seek, for a total of three seeks to match a TOC and return metadata for that TOC.
An example deployment includes a called “Static TOC” using a fixed set of TOCs are being utilized in a read-only implementation. The static nature of the lookup makes it possible to enhance (ideally optimize) the data organization and code for lookups without regard for any updates to this data at a later time. Relieved of the need to add new items to the index at a later time, the index data structure can be arranged in an optimal fashion to allow seek-less, linear scans of index information once the proper scan location in the index has been identified.
An example Static TOC indexing system utilizes a simplified indexing system comprising a TOC “lookup table” and “TOC buckets.” The TOC lookup table contains two dimensions—the number of tracks on the disc and the total play time of the disc. Each coordinate in the TOC lookup table contains a pointer which references a file offset in the TOC buckets. The TOC buckets can be organized linearly based first upon the number of tracks on an album and second upon the total playtime of an album. Contained within each small bucket (e.g. bucket for 4 track, 2540 seconds) is a complete list of all TOCs for albums with the corresponding number of tracks and total play lengths (e.g. CDs with 4 tracks and a total playtime of 2540 seconds). It should be noted here that the disclosure is not limited to only CDs. The same concept, for example, can be applied to a folder of digital music files from a particular album. The indexing scheme will work so long as the number of tracks and total playing length of the album can be determined from the set of digital media files and the TOC for the album can be easily extracted.
If the TOC buckets are linearly organized, a successful search may be conducted with only two disk seeks—one seek in the lookup table to find the offset referencing the correct TOC bucket to begin searching and a second seek to the determined offset in the bucket—regardless of whether performing an exact match or fuzzy match of TOCs. Once matches have been determined, an additional step of fetching metadata related to the specific media (e.g. album/track/artist for an audio CD) requires only a single disk seek, for a total of three seeks to match a TOC and return metadata for that TOC. Because only three disk seeks may be required to generate a match, the Static TOC indexing system can be easily and efficiently implemented on a low end device.
BRIEF DESCRIPTION OF DRAWINGS
Some embodiments are illustrated by way of example and not limitation in the Figures of the accompanying drawings in which:
FIG. 1 illustrates a look-up table, in accordance with an example embodiment, configured to be indexed by track count and play length in seconds;
FIG. 2A illustrates a TOC bucket, in accordance with an example embodiment, configured to be ordered into groups based on the total number of tracks on the CD;
FIG. 2B is a more detailed illustration of a TOC bucket, in accordance with an example embodiment, showing how the TOCs are organized within the TOC bucket;
FIG. 3A is a flow diagram of a method, in accordance with an example embodiment, of determining the number of tracks and total play length of a CD;
FIG. 3B illustrates a flow diagram of a method, in accordance with an example embodiment, of making an exact or fuzzy match for the CD TOC;
FIG. 4 illustrates a flow diagram of a method, in accordance with an example embodiment, of determining whether to follow an exact-matching or a fuzzy matching procedure; and
FIG. 5 illustrates an example computer system which may perform one or more of the methodologies described herein.
DETAILED DESCRIPTION
Example systems and methods for indexing a TOC database are described using an index comprised of a lookup table and bucket file.
The following detailed description refers to the accompanying drawings that depict various details of examples selected to show how the example embodiments may be practiced. The discussion herein addresses various examples of the inventive subject matter at least partially in reference to these drawings, and describes the depicted embodiments in sufficient detail to enable those skilled in the art to practice the embodiments. Many other embodiments may be utilized for practicing the inventive subject matter than the illustrative examples discussed herein, and many structural and operational changes in addition to the alternatives specifically discussed herein may be made without departing from the scope of the inventive subject matter.
Overview
The example systems and methods described herein provide a technique for doing compact disc TOC lookups in a simple and efficient manner. As a result, TOC lookups can be performed on low-end devices to provide a user with information related to the media currently being played (e.g. album/track/title/cover art for an audio CD).
Example Embodiment
FIGS. 1 , 2 A and 2 B
The system and method described herein utilizes a two-part indexing system—a lookup table and buckets. In some embodiments, the two parts of the indexing system are contained within a single file. In some embodiments, the two parts of the indexing system may be contained in separate files.
While not limited to CDs, this particular system and method is well suited for CDs because of the nature of their layout and how they are matched. CDs can be categorized by two characteristics—total tracks and total play length. FIG. 1 is an illustration of an example embodiment of the lookup table as applied to CD TOC lookups. In this particular example, the lookup table 100 has been divided by the number of tracks on the CD and the total playtime of the entire CD. Since a CD can have anywhere between one and ninety-nine tracks, the lookup table 100 has been divided into ninety-nine rows 102 . Furthermore, in this embodiment, it is assumed that the maximum play length of a CD is 4500 seconds (75 minutes) although CD media beyond 75 minutes of playing time are now available. As such, the lookup table 100 has also been divided into 4500 columns 104 . It is convenient to index the look-up table by number of tracks and total playing time because a user will generally want to match discs with the same number of tracks and roughly the same play time. The lookup table 100 is therefore comprised of 445,500 coordinates. Each coordinate within this lookup table 100 contains a reference pointer to an offset within the TOC buckets 200 of FIG. 2A . By indexing these divisions, or “buckets”, the work of finding matches in the database is reduced significantly, as you only need to look at buckets of the correct track count and similar play length. The same idea also works for any set of digital media files that belong to a particular album. The number of digital media files provides the track count while the total playing time of the tracks provides the playtime of the entire album.
FIG. 2A is an illustration of an example embodiment of the TOC buckets 200 corresponding to the lookup table 100 . The TOC buckets 200 are first ordered into groups (e.g. 202 , 204 , 206 ) based upon the total number of tracks on the CD. These basic groups can be organized in linearly ascending orders (e.g. 1 track, 2 track, 3 track, etc.). Within each group, the TOC buckets 200 are then arranged based upon the total play length on the CD (e.g. 1 second, 2 seconds, 3 seconds, etc.). Using this specific organization method, the TOC buckets 200 can be saved in a continuous, read-only file. Other implementations are also possible whereby only some of the buckets are organized in linearly ascending fashion in memory while others are not.
FIG. 2B is a more detailed illustration of a specific segment 250 of FIG. 2A showing the TOCs themselves (e.g. element 258 ) which are contained within these TOC buckets 200 . Within this segment 250 are TOC buckets ranging from element 252 “2460 seconds” through element 256 “2540 seconds” for CDs with a total of 6 tracks. Each TOC bucket may contain a plurality of TOCs which correspond to the play length and number of tracks of the bucket. For example, all TOCs in bucket 252 , such as element 258 “TOC 6-2460-1”, are TOCs of CDs which have 6 tracks and a total play length of 2460 seconds. Element 260 “TOC 6-2460-N” is the final TOC in bucket 252 . Directly following 260 “TOC 6-2460-N” would be “TOC 6-2461-1” (not shown) which is the first TOC for a 6 track CD with total play length of 2461 seconds.
In some embodiments, each TOC, such as 258 “TOC 6-2460-1” contains one or more reference pointers to one or more separate files containing metadata (e.g. artist, track, title, various other album info, cover art, etc.) related to the corresponding album. In other embodiments, the metadata may be contained within the same file.
It should be noted that the example systems and methods described herein contemplates the use of albums with play lengths beyond 4500 seconds. As such, the lookup table need only be modified by adding additional columns as necessary to encompass extended play lengths.
The look-up table 100 is a two-dimensional array of file offsets to TOC buckets 200 , indexed by track count and play length in seconds. Locating a particular bucket requires one seek into the look-up table. Within the look-up table is the bucket offset to get to the right bucket within TOC buckets 200 . For example 106 and 108 in FIG. 1 are both offsets to the right bucket within TOC buckets 200 . Thus, two disk seeks are required—one to jump to the right entry in the look-up table and one to jump to the bucket offset found in the look-up table. When performing an exact match, only one bucket ever needs to be consulted, since potential matches can only reside in one particular bucket for any given TOC. When the correct bucket has been found, a linear scan of that bucket is performed to examine every TOC in the bucket. Thus exact matches only require exactly two disk seeks. Very little CPU power is required, since locating buckets is simply a matter of going to a known location and fetching a single file offset to seek to. This improvement represents approximately one or two orders of magnitude reduction in disk seeks over the aforementioned old method. For example, performing an exact match for a disc with 6 tracks and a play length of 2500 seconds would require seeking to coordinate 106 in look-up table 100 , followed by another seek to bucket 254 . Once bucket 254 has been found, a linear scan of the bucket is performed to find the exact TOC match. Once the exact TOC match has been found, another disk seek is required to fetch the metadata associated with that TOC.
Fuzzy matching only requires two disk seeks as well. The process of fuzzy matching requires that all TOCs with similar play length must be examined. For example, if a 10 track disc is 2500 seconds, then all 10 track discs that are between 2460 and 2540 seconds in length need to be examined. This would require looking in 81 buckets for matches. In a traditional system, this would mean 81 database operations, each of which might translate to a number of disk seeks. The new system still requires looking in 81 buckets, however, the index is arranged so that the buckets are contiguous in the index file, sorted in ascending fashion according to play length. The system would, therefore, only need to seek to coordinate 108 in look-up table 100 and use the offset from coordinate 108 to seek to bucket 252 in FIG. 2B . Subsequently, all that would be required is a linear scan through the index until bucket 254 (corresponding to 2540 second discs) is reached. This is one of more dramatic advantages of this new system, as it reduces the fuzzy matching disk seek requirements by two or three orders of magnitude over a traditional index. In the event that not all buckets are arranged contiguously, then along with the offset to the starting bucket, the look-up table also needs to store the size of the bucket it addresses. This allows the system to know when it has reached the end of a bucket and needs to seek to the start of a new bucket.
Since an exact matching operation in this scheme is essentially identical to fuzzy matching, both exact matching and fuzzy matching can be done in a single operation. When fuzzy matching takes place, the single “exact match bucket” is examined as part of the operation. As fuzzy matching is under way, if an exact match is encountered, processing can stop and the exact match returned in lieu of any fuzzy matches found up to that point. This avoids having to do the four seeks for both the exact and fuzzy matching operation (if the exact match fails).
Therefore, in certain embodiments it may be advantageous to not have different seeking methods for exact and fuzzy matches. Every search can proceed as a fuzzy match. However, this is only of benefit when the sum total size of all the buckets to be examined in the fuzzy matching operation is relatively small, so that simply doing both operations at the same time would take less time than the additional two seeks that are avoided by doing it this way. The decision can be made conditionally by determining the bucket sizes (inexpensively) before proceeding, simply by looking at the start offset of the first bucket and end offset of the last bucket in the look-up table. For example, when searching a disc with 6 tracks and 2502 seconds of playing time, the system could determine how large the buckets are between coordinate 106 and 108 . If the bucket sizes are under some threshold value, the system could simply proceed with a fuzzy match operation as opposed to an exact match. This way the added cost of proceeding first with an exact match and then doing separate disk seeks for the fuzzy match is avoided. Again, this embodiment assumes that the buckets are contiguous. For implementations where not all the buckets are contiguous, certain extra operations will needed to be performed in order to determine whether it's more expensive to proceed seeking using a fuzzy or exact matching technique.
Operation
FIGS. 3 A and 3 B
FIG. 3A is an illustration of an embodiment of the first portion of the method—determining the number of tracks and total play length of a CD. During the first step, 302 , a CD is inputted into the system. During the “TOC determination” step 304 , the system reads the TOC information contained on the CD. An example TOC 305 is illustrated in the figure. Afterwards, during the “track determination” step 306 , the system determines the total number of tracks contained on the CD by subtracting one from the total number of frames in the TOC. In the example TOC, there are 7 frames and therefore 6 tracks on the CD itself. During the “play length determination” step, the system then calculates the total play length of the CD by simply subtracting the first frame of the TOC from the last frame of the TOC and dividing by 75. In the illustrated example, the play length is 2499.96 seconds. Finally, during the “rounding” step 310 , any method of converting the number to an integer value is appropriate so long as it is consistently applied between the system and the indexing method. It should be noted that the “track determination” step 306 and “play length determination” step 308 need not be completed in this particular order. They may be performed in opposite order or concurrently.
FIG. 3B shows an embodiment of the second portion of the method corresponding to FIG. 3A . Once the total play length and the number of tracks of a CD have been determined by the system, the system must then determine whether to scan a single bucket at 350 . In some embodiments, a user may choose to perform exact matching only. Since an exact match requires that the frames of the TOC of the inputted CD precisely match all frames of a reference TOC found in the database, the system would only need to scan a single bucket. In some embodiments, the system may be configured such that it only performs exact matches.
If the system opts to scan only a single bucket, what follows is a three step process. During the first seek 360 , the system searches for the coordinate (number of tracks, total play length) in the lookup table to determine the reference pointer. For example, the system will seek to “A” 106 of the lookup table 100 . As described above with reference to FIG. 1 , this reference pointer will point to the file offset of “TOC buckets”. During the second seek 362 , the system uses the reference pointer to seek to the correct file offset within the “TOC buckets” file. In the example scenario, the system will seek to the “2500 seconds” bucket 254 . Depending on the embodiment, during the final step 364 , the system linearly scans through the entire bucket until it either (a) reaches a TOC which is an exact match (where there are multiple exact matches, the system would proceed to the last matching TOC in the bucket) or (b) reaches the end of the range. In the case where there are multiple identical TOCs, the system would know to stop after the last matching one because typically the TOCs in the index would be arranged contiguously. Where the TOCs are not arranged contiguously, the system would have to scan to the end of the range to ensure that all identical TOCs have been collected.
As will be made apparent to those particularly skilled in the art, in some embodiments, the system will not scan a single bucket as the system resource and processing requirements remain minimal when scanning multiple buckets (“wide-range scan”). For example a fuzzy matching technique would necessitate a wide-range scan. In such cases an exact match of a TOC cannot be found due to minor variances in TOCs (e.g. due to reprinting of a CD). Fuzzy matching can compare a TOC to multiple reference TOCs in a database and, using an algorithm, determine the correct match. Or it may be, as mentioned previously, that in some cases the system may be configured to perform both exact and fuzzy matching as one single operation if the bucket sizes are under some predetermined threshold value.
If the system scans through multiple buckets, what follows is a four-step process. In the first step 370 , the system determines the correct coordinate in the look-up table to get the bucket offset address from. Referring back to the previous example (6 track CD with a total play length of 2500 seconds), the system may be configured to scan a range of +/−40 seconds (2460 seconds through 2540 seconds). During the first seek 372 , the system would seek to the first bucket in this range (“beginning” bucket, e.g. “B” 108 in the lookup table 100 ) to determine the reference pointer. During the second seek 374 , the system uses this reference pointer to seek to the correct file offset within the “TOC buckets” file. In the example, the system will seek to the “2460 seconds” bucket 252 . During the final step 376 , the system will linearly scan through the entire range of buckets until it either (a) reaches a TOC which is an exact match (where there are multiple exact matches, the system would proceed to the last matching TOC in the bucket), or (c) reaches the end of the range.
As such, performing fuzzy matching also only requires two seeks and a linear scan. As mentioned previously, in certain other embodiments where the buckets are not contiguously arranged, certain extra calculations and seeks may be required.
Automatic Determination of Single-Bucket Scan
FIG. 4
Due to the requirement of only two seeks for either a single-bucket scan or a wide-range scan, it may be that doing a wide-range scan for even an exact match may be more efficient than doing 2 seeks for an exact match followed by 2 additional seeks for a fuzzy match in the event no exact match is found. In many cases, performing exact matching prior to performing fuzzy matching may be unnecessary. Therefore, in some embodiments, exact matching is performed during the fuzzy matching process. As was explained above with reference to FIG. 3B , a wide-range scan completes if an exact match is found.
However, in certain circumstances (e.g. the size of the range of buckets is large), it may be beneficial to perform exact matching prior to fuzzy matching. In some embodiments, the system may dynamically determine whether to perform a single-bucket scan prior to performing a wide-range scan. FIG. 4 is an illustration of an example embodiment which dynamically determines whether exact matching should be performed prior to fuzzy matching.
In FIG. 4 , the system has already determined the total play length of the CD, the number of tracks on the CD, and the first bucket to locate in the lookup table based upon the wide-range scan parameters. During the first seek 402 , the system searches the lookup table for the beginning bucket of the wide-range scan (e.g. “6 track, 2460 seconds”) to determine the first file offset. During the second seek 404 , the system searches the lookup table for the bucket following the last bucket of the wide range scan (e.g. last bucket is “2540 seconds”, therefore seek “2541 seconds”). During the “file offset calculation” step 406 , the system uses the file offsets (gathered from reference pointers) and calculates the difference. Through an algorithm 410 , the system determines whether it is more efficient to perform a single-bucket scan prior to a wide-range scan.
If a single-bucket scan is performed first, the system follows a procedure similar to 360 , 362 , and 364 of FIG. 3B . During step 420 , the system performs a third seek and searches for the single-bucket (the “exact” bucket) in the lookup table to locate the reference pointer. Afterwards, during the following step 422 , the system performs a fourth seek to the file offset within the “TOC bucket” file. During the linear scan step 424 , the system linearly scans through the entire bucket until it either a) reaches a TOC which is an exact match or (c) reaches the end of the range.
If no exact match is found 426 , the system then moves to step 430 . During step 430 , the system seeks to the file offset in the “TOC bucket” file to locate the “beginning” bucket of the wide-range scan. During the final step 432 , the system linearly scans through the entire range of buckets until it either (a) reaches a TOC which is an exact match, or (c) reaches the end of the range.
If the system determines that a single-bucket scan should not be performed, the system bypasses steps 420 through 426 .
Metadata Display
The album metadata associated with the static TOC index can be stored in either the same or different files. For example, the static TOC index can be associated with the album metadata stored in other static flat data files, by storing the offset of the album data in the static TOC index. When a TOC is matched, the record may contain one or more offsets into one or more associated metadata files. To fetch the metadata for a match only requires a single disk seek to the indicated location in the metadata file. This avoids yet another b-tree database access, as would be required in a more traditional implementation.
Also, in addition to the TOC metadata database with all the recognition information, one can associate with it any number of static separately indexed databases which will hold other information such as metadata, cover art etc. The TOC table can be a single flat file (or multiple flat files) containing file offsets that specify which address to jump to in, for example, the metadata table. This is why multiple disk accesses are not required because the exact location will be specified in the TOC table. One would not have to traverse trees as in standard database implementations.
TOC Hash Table
Matching using the Static TOC index can further be sped up by the addition of a TOC hash table. By hashing the TOCs (using the MD5 message digest algorithm, for example), and indexing them in a similar static index, each individual bucket is smaller, on the average. This is because a good hashing algorithm provides a more uniform distribution than the raw TOCs alone. Matches still require only two seeks, but the bucket sizes will be smaller, requiring less linear scanning of buckets on the disk (and fewer comparisons, leading to reduced CPU consumption).
Updates
Due to the read-only nature of the static TOC files (lookup tables and buckets), the static TOC files themselves are not directly updated as doing so would disrupt the organization of the file itself. For ad-hoc updates, e.g. new records perhaps hand-entered by the end user or fetched from some external online source, etc., instead of adding it to this “pre-cooked” static array of TOC values, one would simply add a second b-tree database with the updates. A user is unlikely to ever add more than a couple hundred ad-hoc CD updates, which is a small enough number such that keeping this information in a separate b-tree database to do a quick local look up before trying the embedded database would not be very costly (because of the b-tree's small size, less seeks will be required, and each seek is likely to be a short one due to the locality of disk blocks in the small database). For large, pre-built database updates, a second static TOC index would be added containing only updated information. Since the original pre-cooked table would only require 2 disk seeks to find a match, it would not be very expensive from a processing standpoint to add an additional table where you could also use up 2 disk seeks to find a match. Lookups would require searching both indexes, but would still require only 2 seeks per index (for a total of 4). One would have to get upwards of 150 disk seeks or more to approach the slowness of the current look-up algorithm. Thus, 74 additional static TOC indexes would have to be added before the system approaches the slowness of the current lookup algorithm. Presumably, large pre-built updates would be infrequent (on the order of several months apart), thus making it unlikely that lookups would ever get too slow over the life of the product. An alternate approach would be to always replace the entire static TOC index with each update, or to always replace the last update with a single updated index containing all cumulative changes since the original static TOC index was created; these two alternate approaches ensure that there are never more than two static TOC indices, regardless of the number of updates.
Compression of Index
As discussed previously, one possible additional benefit of the example embodiments may be that the new system is more compact than a traditional index e.g. b-tree index. An additional benefit of the new system is that it is more compact than a traditional index (such as a b-tree index). The overhead of a b-tree index is variable, and increases as more records are added to the index. Typically, 20-40% of the space consumed by a b-tree index is devoted to indexing information, with the remainder being used to store the actual data itself. This represents a large amount of “wasted” storage space. The overhead of the static TOC index is fixed at 445,500 values, or about 1.7 megabytes, regardless of how many records are stored in the index. This represents about 4.25% for an index of average size (about 40 megabytes), and even less for a larger index.
The index size can be further reduced by storing the TOCs in a special compressed format. Standard compression methods do not result in appreciable size reduction, because of their seemingly random nature. Random patterns confound traditional compression algorithms such as Huffman coding or Lempel-Ziv compression. To be effective, a TOC compression algorithm must be designed specifically for the task of compressing CD TOCs, based on knowledge of TOC offset frequencies; it must also be usable for matching in compressed form, to avoid the expensive task of decompressing each TOC being compared before matching can take place. TOC offsets are simply numbers representing the offset of each song on a compact disc, in frames of 75ths of a second. By subtracting adjacent offsets, the length of each song on the disc can be determined. Because the vast majority of songs are much shorter than about 7 minutes (32768 frames), most of the offsets can be stored as 15 bit integer (with the 16th bit used as a flag indicating the more rare case when a song is longer than 32768 frames). This allows storing most TOC offsets as 2-byte integers, instead of the 4 normally required to store offsets, effectively cutting the size of the TOC index in half (aside from the hash table overhead). Furthermore, because this compression method keeps the offsets in integer form, TOCs can be compared without having to decompress them first—they can be compared to each other directly in compressed form.
FIG. 5 is a block diagram of an article 500 of manufacture, including a specific machine 502 , according to various example embodiments. Upon reading and comprehending the content of this disclosure, one of ordinary skill in the art will understand the manner in which a software program can be launched from a computer-readable medium in a computer-based system to execute the functions defined in the software program.
One of ordinary skill in the art will further understand the various programming languages that may be employed to create one or more software programs designed to implement and perform the methods disclosed herein. The programs may be structured in an object-orientated format using an object-oriented language such as Java or C++. Alternatively, the programs can be structured in a procedure-orientated format using a procedural language, such as assembly or C. The software components may communicate using any of a number of mechanisms well known to those of ordinary skill in the art, such as application program interfaces or interprocess communication techniques, including remote procedure calls. The teachings of various embodiments are not limited to any particular programming language or environment. Thus, other embodiments may be realized.
For example, an article 500 of manufacture, such as a computer, a memory system, a magnetic or optical disk, some other storage device, and/or any type of electronic device or system may include one or more processors 504 coupled to a machine-readable medium 508 such as a memory (e.g., removable storage media, as well as any memory including an electrical, optical, or electromagnetic conductor) having instructions 512 stored thereon (e.g., computer program instructions), which when executed by the one or more processors 504 result in the machine 502 performing any of the actions described with respect to the methods above.
The machine 502 may take the form of a specific computer system (e.g., a vehicle audio system, a portable media player, or the like) having a processor 504 coupled to a number of components directly, and/or using a bus 516 . Thus, the machine 502 may perform any one or more of the methods described herein and define a system as herein described.
Turning now to FIG. 5 , it can be seen that the components of the machine 502 may include main memory 520 , static or non-volatile memory 524 , and mass storage 506 . Other components coupled to the processor 504 may include an input device 532 , such as a keyboard, or a cursor control device 536 , such as a mouse. An output device 528 , such as a video display, may be located apart from the machine 502 (as shown), or made as an integral part of the machine 502 .
A network interface device 540 to couple the processor 504 and other components to a network 544 may also be coupled to the bus 516 . The instructions 512 may be transmitted or received over the network 544 via the network interface device 540 utilizing any one of a number of well-known transfer protocols (e.g., HyperText Transfer Protocol). Any of these elements coupled to the bus 516 may be absent, present singly, or present in plural numbers, depending on the specific embodiment to be realized.
The processor 504 , the memories 520 , 524 , and the storage device 506 may each include instructions 512 which, when executed, cause the machine 502 to perform any one or more of the methods described herein. In some embodiments, the machine 502 operates as a standalone device or may be connected (e.g., networked) to other machines. In a networked environment, the machine 502 may operate in the capacity of a server or a client machine in server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment.
The machine 502 may comprise a personal computer (PC), audios system (e.g., a vehicle audio system, portable media player, etc) a tablet PC, a set-top box (STB), a PDA, a cellular telephone, a web appliance, server, client, or any specific machine capable of executing a set of instructions (sequential or otherwise) that direct actions to be taken by that machine to implement the methods and functions described herein. Further, while only a single machine 502 is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.
While the machine-readable medium 508 is shown as a single medium, the term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers, and or a variety of storage media, such as the registers of the processor 504 , memories 520 , 524 , and the storage device 506 that store the one or more sets of instructions 512 . The term “machine-readable medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine 502 to perform any one or more of the methodologies of the present invention, or that is capable of storing, encoding or carrying data structures utilized by or associated with such a set of instructions. The terms “machine-readable medium” or “computer-readable medium” shall accordingly be taken to include tangible media, such as solid-state memories and optical and magnetic media.
Various embodiments may be implemented as a stand-alone application (e.g., without any network capabilities), a client-server application or a peer-to-peer (or distributed) application. Embodiments may also, for example, be deployed by Software-as-a-Service (SaaS), an Application Service Provider (ASP), or utility computing providers, in addition to being sold or licensed via traditional channels.
Implementing the apparatus, systems, and methods described herein may operate to provide improved resource management, by prioritizing requests and taking advantage of associated cloud computing architectures. Increased project management efficiency, more immediate response to customer service issues, and increased user satisfaction may result.
This Detailed Description is illustrative, and not restrictive. Many other embodiments will be apparent to those of ordinary skill in the art upon reviewing this disclosure. The scope of embodiments should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b) and will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
In this Detailed Description of various embodiments, a number of features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as an implication that the claimed embodiments have more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. | A method and system is provided for doing compact disc TOC look-ups cheaply and efficiently by using a special indexing mechanism particularized to TOC look-ups. The indexing scheme allows a successful search of TOCs using as few as 2 disk seeks in contrast to the usual hundreds of disk seeks required by a general purpose indexing scheme. This performance improvement is achieved by using a static database of TOCs in a read-only implementation so that the data organization and code for lookups can be optimized without regard for any updates to this data at a later time. The index data structure is arranged in a fashion that allows for seek-less, linear scans of index information once the proper scan location in the index has been identified. | 6 |
FIELD OF THE INVENTION
[0001] The present invention provides modified microorganisms for raising host immune responses as well as vaccines and vaccine compositions comprising the same. In particular, the invention provides a modified Streptococcus , which may form the basis of an improved vaccine for treating and/or preventing diseases.
BACKGROUND OF THE INVENTION
[0002] Several species of the genus Streptococcus are the causative agents of a number of diseases in humans and animals. In humans, the most frequently-encountered pathogenic species is S. pneumoniae (the pneumococcus), which causes sinusitis and otitis media, but also life-threatening conditions including pneumonia, sepsis, osteomyelitis, endocarditis, septic arthritis and meningitis among others. Second most frequently encountered in humans is the Group A Streptococcus (GAS), S. pyogenes , which is responsible for pharyngitis, glomerulonephritis, acute rheumatic fever, scarlet fever and on occasion, necrotising fasciitis. Other species, such as S. mutans , may constitute part of the normal human microflora, yet may pose a disease risk under the right conditions.
[0003] Animal diseases caused by streptococci are no-less significant than those in humans. For example, S. suis causes respiratory disease, joint infections, skin conditions and meningitis in pigs. Furthermore, this organism is zoonotic, and may be acquired occupationally, resulting in meningitis, endocarditis and/or septicaemia. Another significant animal pathogen is S. equi , which causes strangles in horses. In the dairy industry, one of the major causes of mastitis in lactating cattle is S. uberis , while S. dysgalactiae subsp. dysgalactiae also contributes to the incidence of this disease. Likewise, S. agalactiae is also recognised as a cause of mastitis, but is also responsible for causing a range of other diseases in a diverse number of species including fish, aquatic mammals and humans.
[0004] While vaccines against some of the major Streptococci pathogens exist, many are unreliable, inducing weak, short-lived and/or ineffective immune responses. As such, there is a requirement for new vaccines against streptococci which induce immunity in human and animal hosts.
SUMMARY OF THE INVENTION
[0005] The present invention is based on the finding that microorganisms can be modified so as to express certain factors important in generating or raising host immune responses. In particular, the invention provides modified microorganisms which, when subjected to conditions which would be expected to suppress or reduce the expression, function and/or activity of certain factors, exhibit increased (often significantly increased) expression, function and/or activity of those factors. In one embodiment, the factors may be virulence factors.
[0006] The modified microorganisms provided by this invention may find application as agents for generating or raising immune responses and as vaccines or vaccine compositions to protect against a variety of diseases and/or conditions and/or to prevent or reduce host colonisation/infection by one or more pathogens.
[0007] In a first aspect, the present invention provides a modified microorganism capable of expressing at least one factor under conditions in which a wild-type (or unmodified) strain of the same microorganism, exhibits inhibited expression of the at least one factor.
[0008] It should be understood that while this invention may be described as “comprising” one or more features, the term “comprising” encompasses aspects and embodiments which “consist essentially of” or “consist of” the noted feature(s).
[0009] As such, the invention may provided a modified bacterium capable of expressing at least one factor under conditions in which a wild-type (or un-modified) strain of the same bacterium, exhibits inhibited expression of the at least one factor.
[0010] The modified bacterium may be a modified Streptococcus species wherein, under environmental conditions suppressing or inhibiting the expression of a factor or factors in a wild-type or un-modified form of the same Streptococcus species, the modified Streptococcus species express the factor or factors. It should be understood that references to “ Streptococcus species” encompass not only the specific species, S. suis and S. equi , but other species such as, for example, S. pyrogenes, S. epidermidis, S. pneumoniae, S. gordonii and/or S. mutans.
[0011] The modified Streptococcus species may be a modified Streptococcus suis or a modified Streptococcus equi wherein, under environmental conditions suppressing or inhibiting the expression of a factor or factors in a wild-type or un-modified S. suis or S. equi , the modified S. suis and S. equi express the factor or factors.
[0012] The term “factors” should be understood as encompassing proteinaceous compounds (for example proteins, peptides, amino acids and/or glycoproteins as well as small organic compounds, lipids, nucleic acids and/or carbohydrates produced by microorganisms. Many of these factors are expressed internally—i.e. within the cytoplasm of the microorganism; such factors may be classed as “internal” or “cytoplasmic”. The term “factors” may also encompass microbial factors which are secreted from the cell and/or targeted to the microbial cell wall as membrane—bound or transmembrane factors. The term “factors” may further comprise antigenic or immunogenic compounds which elicit or generate host immune responses. Such factors may include those collectively known as “virulence determinants/factors” and/or “pathogenicity factors”. One of skill will appreciate that microbial factors which are also virulence determinants/factors and/or pathogenicity factors, may comprise, for example, those which facilitate microbial attachment to host surfaces or cells and/or host cell invasion as well as those involved in toxin production and/or the toxins themselves. In view of the above, the term “factors” as used herein may comprise microbial cell wall, membrane and/or transmembrane structures such as proteins or compounds which mediate or facilitate host adherence or colonisation, pili and/or secreted enzymes, compounds and/or toxins. The term “factors” may further comprise compounds involved in metal ion acquisition.
[0013] One of skill will appreciate that in wild-type microorganisms, for example wild-type bacteria including Streptococcus species (such as, for example, S. suis and/or S. equi ), the expression, function and/or activity of one or more factor(s) may be directly or indirectly regulated by one or more exogenous and/or endogenous elements.
[0014] An endogenous element may directly or indirectly regulate the activity, expression and/or function of a microbial factor. An “endogenous” regulatory element may be a microbial element which regulates the function, expression and/or activity of one or more microbial factors. In contrast, an “exogenous” regulatory element may comprise an element which is not produced by, or is not a product of, a microorganism, but which directly or indirectly regulates the expression, function and/or activity of a factor expressed by that microorganism.
[0015] One of skill will appreciate that in some cases, exogenous and/or endogenous regulatory elements of the type described herein, act as global regulatory elements. Global regulatory elements may regulate and/or control the expression, function and/or activity of a plurality of microbial factors.
[0016] The exogenous regulatory element may comprise an environmental element. One of skill will appreciate that an environmental regulatory element may comprise a particular nutrient, compound, vitamin, metabolite, mineral, ion, electrolyte and/or salt. Additionally, or alternatively an environmental regulatory element may take the form of a physical condition such as, for example, a particular temperature, gas ratio, osmolairty and/or pH.
[0017] One of skill will readily understand that the presence and/or absence of one or more (exogenous) environmental regulatory elements may directly modulate the expression, function and/or activity of one or more microbial factor(s). In other cases, the presence and/or absence of one or more environmental regulatory element(s) may modulate the expression, function and/or activity of one or more endogenous microbial regulatory element(s) (for example an endogenous (microbial) global regulatory element) which in turn effects the expression, function and/or activity of one or more microbial factor(s).
[0018] Modified microorganisms provided by this invention may lack one or more endogenous regulatory/control elements. In one embodiment, the modified microorganisms may lack one or more environmentally—sensitive or responsive regulatory/control elements. As a consequence of these modifications, the modified microorganisms described herein are characterised by the expression/function and/or activity of one or more factors in environments (or under conditions) which would normally (i.e. in a wild-type or unmodified strain) suppress or inhibit the expression, function and/or activity of said factors.
[0019] The factors expressed by the modified microorganisms described herein may comprise factors, the expression, function and/or activity of which is normally associated with, controlled/regulated by, dependent on and/or sensitive to, the presence and/or absence of metal ions such as, for example iron (Fe 2+ ) and/or manganese (Mn 2+ ).
[0020] Advantageously, and where the invention relates to, for example, modified Streptococcus , such factors may comprise one or more Streptococcus antigens/immunogens (virulence factors) said antigens and/or immunogenes being capable of generating, raising and/or eliciting a host immune response.
[0021] Accordingly, the invention may relate to a modified species of the Streptococcus genus, expressing at least 1 factor under conditions comprising manganese and/or iron concentrations which inhibit the expression of said factor in wild-type or unmodified strains of the same organism.
[0022] The modified microorganisms provided by this invention may comprise one or more genetic modification(s) which directly and/or indirectly affect the expression, activity and/or function of one or more microbial regulatory elements (including global regulatory elements). A genetic modification which affects the expression, function and/or activity of a microbial regulatory element, may comprise one or more mutations in the sequence of a gene encoding said regulatory element. In contrast, a genetic modification which indirectly affects the expression, function and/or activity of a microbial regulatory element, may comprise one or more mutations in the sequence of a gene or genes which encode other elements or factors which themselves affect the activity, function and/or expression of the regulatory element.
[0023] A genetic modification may comprise one or more alterations in a nucleic acid sequence. For example, a nucleic acid sequence may be modified by the addition, deletion, inversion and/or substitution of one or more nucleotides of a sequence. One of skill will appreciate that a genetic modification may effect the expression, function and/or activity of the nucleic acid sequence harbouring the modification and/or the expression, function and/or activity of the protein or peptide encoded thereby.
[0024] Advantageously, modified microorganisms provided by this invention comprise genetic lesions resulting in the (“in-frame”) deletion of nucleic acid sequences. Furthermore, the modified microorganisms of this invention may lack exogenous nucleic acid—for example nucleic acids derived from vectors (for example plasmids and the like). As such, when compared to isogenic, wild-type parent strains, a modified microorganism (for example a modified Streptococcus ) of this invention may be identical except for the mutation or deletion of sequences encoding one or more regulatory elements.
[0025] In Corynebacterium diphtheriae , a number of virulence factors (including diphtheria toxin (encoded by the tox gene)) are regulated by the metal ion-activated global regulatory element, DtxR (product of the dtxR gene). Other bacterial species including, for example other Corynebacterium and Streptococcus species, comprise global regulators which are structurally and/or functionally homologous (and/or (substantially) identical) to the dtxR/DtxR gene/protein of C. diphtheriae.
[0026] Without wishing to be bound by theory, the inventors have discovered that microorganisms (for example species belonging to the Streptococcus genus) exhibiting modified expression, function and/or activity of a gene and/or protein homologous to the dtxR gene and/or DtxR protein of Corynebacterium diphtheriae , represent exemplary vaccine candidates.
[0027] In view of the above, this invention may provide modified microorganisms capable of expressing at least one factor under conditions in which a wild-type (or un-modified) strain of the same microorganism, exhibits inhibited expression of the at least one factor, wherein the modified microorganism lacks (i) a functional dtxR homologue, (ii) a gene functionally equivalent to dtxR and/or (iii) a gene or protein which is “dtxR like”. For convenience, options (i), (ii) and (iii) above will, hereinafter, be collectively referred to as “dtxR homologues”. It should be understood that dtxR homologues encompassed by this invention (including genes/proteins which are dtxR-like) may exhibit variable (perhaps low) sequence homology/identity with the dtxR gene/protein of Corynebacterium diphtheriae but a high degree of functional homology/identity with dtxR—in other words, the dtxR homologues described herein are metalo-regulators which, through binding metal ions, exert an effect on gene expression.
[0028] It should be understood any gene and/or protein being described as “functionally homologous” to the dtxR and/or DtxR gene/protein of C. diphtheriae , is a gene and/or protein which exhibits metalo-regulator activity characteristic of, or similar to the metalo-regulator activity of the dtxR/DtxR gene/protein of C. diphtheriae.
[0029] The sequence encoding the C. diphtheriae dtxR gene is provided as SEQ ID No:1, below.
[0000]
SEQ ID NO: 1
1
atgaaagatt tggtcgatac cacagaaatq tatctgcgga ccatctacga gctggaagaa
61
gagggagtaa ctccccttcg cgcacgcatc gcCgaacgcc tcgatcaqtc aggccctaca
121
gtcagCtaaa cagttgCccg catggaacgt gacgggctcg ttgtaqttgc gtctgaccgt
181
agtcttcaaa tgacgcccac tgggcgcgct ttagccatcg ccgtaatgcg taaacatcgc
241
ctcgcagagc gccttcttac agacattatt ggcttagata tccacaaggt gcacgatgaa
301
gcatgccgCt gggagcacgt catgagcgat gaagtagagc ggcggcttgt tgatgtcctc
361
gaggacgtca cccgctcccc ctttggcaac ccaatcccag gtctcgatga acttggcgtc
421
tccataaaaa agaaggaagg accgggcaaa cgtgccgtgg atgtagcccg tgccaccccc
481
agagacgtaa agattgttca aatCaacgag atattgcaag tagattctga ccagtttcag
541
gctctgatcg acgcaggcat tagaattgga acgaccgtca cgctcagcga tgtagacggt
601
cgcgtgatta ttacgcacgg tgaaaaaaca gtagaactta tcgacgacct agctcacgca
661
gtacgaatcg aagaaatcta a
[0030] An exemplary DtxR protein sequence has been deposited as accession No: YP_005162868. A sequence of the dtxR protein is given as SEQ ID NO: 2 below:
[0000]
SEQ ID NO: 2
1
mkdlvdttem ylrtiyelee egvtplrari aerleqsgpt vsqtvarmer dglvvvasdr
61
slqmtptgrt latavmrkhr laerlltdii gldinkvhde acrwehvmsd everrlvkvl
121
kdvsrspfgn pipgldelgv gnsdaaapgt rvidaatsmp rkvrivqine ifqvetdqft
181
qlldadirvg seveivdrdg hitlshngkd vellddlaht irieel
[0031] Homologous and/or identical dtxR and/or DtxR genes/proteins may encompass those encoded by nucleic acid and/or amino acid sequences which exhibit at least about 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% homology or identity with SEQ ID NOS: 1 or 2 above or fragments thereof.
[0032] The degree of (or percentage) “homology” between two or more (amino acid or nucleic acid) sequences may be determined by aligning the sequences and determining the number of aligned residues which are identical and adding this to the number of residues which are not identical but which differ by redundant nucleotide substitutions—the redundant nucleotide substitution having no effect upon the amino acid encoded by a particular codon, or conservative amino acid substitutions. The combined total is then divided by the total number of residues compared and the resulting figure is multiplied by 100—this yields the percentage homology between aligned sequences.
[0033] A degree of (or percentage) “identity” between two or more (amino acid or nucleic acid) sequences may also be determined by aligning the sequences and ascertaining the number of exact residue matches between the aligned sequences and dividing this number by the number of total residues compared—multiplying the resultant figure by 100 would yield the percentage identity between the sequences.
[0034] This invention provides a modified microorganism, wherein the modified microorganism comprises a modified dtxR/DtxR homologue. The invention may also provide modified microorganisms of the Streptococcus genus, wherein the modified microorganism of the Streptococcus genus comprises a modified dtxR/DtxR homologue. In these embodiments, the modified dtxR/DtxR homologue may exhibit a degree of homology/identity (as defined above) to the sequences disclosed as SEQ ID NOS: 1 and 2 herein.
[0035] Insofar as this specification relates to modified Streptococci, examples of dtxR/DtxR homologues to be exploited (i.e. modified) for production of a modified microorganism of this invention, may include those listed in Table 1 below.
[0000]
TABLE 1
dtxR homologues in Streptococcus species
Metal
Organism
Regulator
ion binding
Ref/Accession
S. suis
ScaR
Mn 2+
Jakubovics et al 2000
(aka SloR)
S. equi
TroR
S. pyrogenes
MtsR
Mn 2+
Jakubovics et al 2000
S. epidermidis
SirR
Mn 2+
CAA67572
S. pneumoniae
PsaR
Jakubovics et al 2000
S. gordonii
ScaR
AAF25184
S. mutans
SloR
Jakubovics et al 2000
[0036] A modified S. suis of this invention may take the form of a scaR deficient (scaR − ) strain, genetically modified to lack a functional scaR gene or product (i.e. a functional “ScaR” protein). A modified S. suis according to this embodiment of the invention may express factors (for example virulence factors) normally under the control of ScaR in a manner which is independent of the expression, function and/or activity of ScaR.
[0037] The sequence of the S. suis scaR gene (a dtxR homologue) is given below as SEQ ID No.: 3.
[0000] SEQ ID NO: 3: S. suis scaR atgacaccaaacaaagaagattacctaaaatgtatttatgaactgggtca attagaccaaaaaattaccaataaactcatcgcagagaagatggccttct ccgcaccagccgtttccgaaatgctcaaaaaaatggtagccgaagagctc atttctaaggatgccaaggcaggttatctcctcagtcaaactgcccttga aatggtagccagcctctatcgcaaacaccgcttgattgaggtattcttag ttgagcaacttggctactctccagaagaagtacatgaagaggctgagatt ttagaacacaccgtatcagatcactttatcaatcgcctagacctgctact ggaacagcctcaaacttgtcctcacgggggaagcattcctcaagcaggac aaccgctcatcgaacgctaccagacacggctgtcacagctaactgagaca gggaactaccagcttgtccgtatccatgacttctatcaactccttcagta cttggaacaacatgaattagctgtcggtgatttactaaccgccgtcccaa cagccatcgctcaacaattattcatcgaaaaaagcaatcgcccagcctaa
The sequence of the S. suis ScaR protein is given below as SEQ ID No.: 4.
[0000]
SEQ ID NO: 4: S. suis ScaR
MTPNKEDYLKCIYELGQLDQKITNKLIAEKMAFSAPAVSEMLKKMVAEEL
ISKDAKAGYLLSQTALEMVASLYRKHRLIEVFLVEQLGYSPEEVHEEAEI
LEHTVSDHFINRLDLLLEQPQTCPHGGSIPQAGQPLIERYQTRLSQLTET
GNYQLVRIHDFYQLLQYLEQHELAVGDLLTVTAFDQFAQTITIQYKDKEL
AVPTAIAQQLFIEKSNRPA
[0038] The function and/or activity of the scaR protein is sensitive and/or response to environmental manganese concentrations. Without wishing to be bound by theory, manganese present in the environment, combines and forms complexes with ScaR; in S. suis , this results in a conformational change which allows ScaR to bind specific sequences within, or associated with, the promoter regions of target genes—for example, genes encoding ScaR-regulated microbial ( S. suis ) factors. As a result of the binding between ScaR/manganese complexes and sequences (for example scaR-specific nucleic acid motifs in the vicinity of promoted sequences) associated with ScaR regulated genes (encoding S. suis factors as described herein), transcription of these genes is modulated, in some cases inhibited, suppressed or prevented. While the production of internal and/or external microbial factors may be limited in manganese-rich environments, the growth of S. suis is strong and vigorous.
[0039] In contrast, in environments where manganese is unavailable or where manganese concentrations are low, ScaR does not (or cannot) complex with manganese and remains in a confirmation that is unable to bind some target sequences. As such, in the absence of manganese, ScaR-regulated promoters are not impeded from initiating transcription. However, while microorganisms such as S. suis may be able to express certain internal and/or external factors (for example virulence determinants) in environments where metal ion (in particular manganese) availability is low, microbial growth may be poor.
[0040] The inventors have discovered that S. suis ScaR-deficient strains, such as those described herein, are able to express certain factors independently of environmental manganese levels and are thus able to be cultured in manganese rich environments so as to markedly improve growth. In this way, standard laboratory culture conditions/media may be used to produce much higher amounts/concentrations of virulence factors than would otherwise be possible through culture of wild-type S. suis (i.e. scaR + strains) under equivalent conditions.
[0041] In view of the above, the present invention provides modified S. suis which, under standard laboratory conditions is capable of expressing factors normally only expressed during an infection (i.e. in vivo). It should be understood that the term “standard laboratory conditions” may include environmental conditions comprising manganese and/or containing concentrations of manganese, sufficient to form ScaR/manganese complexes and inhibit or prevent expression of the factors described herein.
[0042] Furthermore, modified S. suis as described herein, can be grown in the presence of manganese while still retaining the ability to express a number of virulence factors normally under the control of the scaR protein. This is important as the presence of manganese promotes strong growth of the modified S. suis provided by this invention. Furthermore, one of skill will appreciate that a modified S. suis strain which can be grown under conditions which promote strong/vigorous growth, may be particularly well suited to vaccine production where large amounts of microbial material are required to produce sufficient quantities of vaccine.
[0043] Thus, an embodiment of this invention produces a S. suis scaR-deficient strain, wherein the strain expresses factors normally under the control of the ScaR protein, under conditions which comprise manganese concentrations sufficient to inhibit the expression of said factors in wild-type (or un-modified strains).
[0044] It should be understood that this invention may extend to any Streptococcus species within the Streptococcus genus. For example, where the invention relates to S. equi , the modified microorganism may be a strain lacking a functional troR/TroR gene/protein or a troR/TroR-deficient strain. The invention may also provide a S. pyogenes lacking (functional) or defincient in, mtsR/MtsR; S. epidermidis lacking (functional) or defincient in, sirR/SirR; S. pneumoniae lacking (functional) or deficient in, psaR/PsaR; gordonii lacking (functional) or deficient in scaR/ScaR; and/or S. mutans lacking (functional) or deficient in, sloR/SloR.
[0045] One of skill will appreciate that the modified ( Streptococcus ) microorganisms provided by this invention, may find application as strains from which vaccines may be produced.
[0046] The modified microorganism is not a modified Corynebacterium . In a further embodiment, the microorganism is not a modified C. pseudotuberculosis.
[0047] Accordingly, a second aspect of this invention provides a modified microorganism of the invention for use in raising an immune response in an animal. Moreover, the modified microorganisms described herein may be used to create vaccines for use in treating/preventing and/or controlling disease.
[0048] The invention may further provide vaccines for use in treating, preventing and/or controlling diseases caused and/or contributed to by Streptococcus species. In one embodiment, the invention provides a Streptococcus suis scaR/ScaR-deficient strain for use in raising an immune response in an animal and/or for use as a vaccine. It should be understood that any Streptococcus deficient in a dtxR-like gene/protein (for example an S. equi troR-deficient strain) may be used in treating, preventing and/or controlling diseases caused and/or contributed to by Streptococcus species.
[0049] It should be understood that the term “animal” may encompass mammalian animals including, for example, humans, equine, or ruminant (for example bovine, ovine and caprine) species, avian species and/or fish.
[0050] Where the vaccine provided by this invention is based on modified organisms of the Streptococcus genus (for example a modified S. suis or S. equi ), the vaccine may find application in the treatment, prevention and/or control of diseases and/or conditions caused or contributed to by one or more Streptococci, including, for example meningitis, septicaemia, respiratory disease and/or strangles.
[0051] One of skill will appreciate that the modified microorganism, for example a modified Streptococcus , provided by this invention, may be used as a whole-cell killed vaccine. In this embodiment, the vaccine may be prepared as a bacterin vaccine, comprising a suspension of killed modified microorganisms. In other embodiments, the vaccines may comprise portions and/or fragments of the modified Streptococcus , the portions or fragments being generated by fragmentation/fractionation procedures/protocols such as, for example, sonication, freeze-thaw, osmotic lysis and/or processes which isolate sub-cellular fractions or factors secreted by the modified microorganisms into the extracellular milieu.
[0052] One of skill will appreciate that the general strategy of preparing a (bacterin) vaccine using a microorganism modified so as increase the expression of virulence factors when cultured (for example, under standard laboratory conditions (in the case of S. suis , such conditions comprising quantities of manganese sufficient to enhance or encourage growth), is somewhat at odds with routine protocols which aim to down regulate or attenuate microbial virulence factors before a microorganism is provided as a live attenuated (not killed) vaccine.
[0053] A further aspect of the invention provides a method of making any of the vaccines described herein, said method comprising the step of culturing a modified microorganism provided by this invention and preparing a vaccine composition therefrom. Vaccine compositions according to this invention and/or prepared by methods described herein, may otherwise be known as “immunogenic compositions”—such compositions being capable of eliciting host immune responses.
[0054] A method of making a modified S. suis for use in treating, preventing and/or controlling specific diseases (such as those described herein) may comprise culturing the scaR/ScaR-deficient S. suis strain described herein, under conditions which comprise manganese or manganese concentrations which would otherwise inhibit wild-type ScaR activity or function, and preparing a vaccine composition therefrom. Other streptococcal species may comprise metalo-regulatory factors which are “sensitive” to other types of metal ion—for example iron. In such cases, methods for making vaccines comprising modified forms of these species may exploit iron concentrations which would otherwise alter wild-type activity and/or function of the metallo-regulatory protein such that expression of target genes (for example genes encoding virulence factors) is modified/altered (for example inhibited or reduced).
[0055] Vaccine compositions of this invention may comprise killed forms of any of the modified microorganisms described herein and/or fragments and/or portions derived from modified microorganisms of this invention. The vaccines of this invention may be formulated together, or in combination with one or more adjuvant(s), microbial components (for example one or more bacterium or a component thereof), viral components, parasitic components, pharmaceutically acceptable carrier(s), excipient(s) and/or diluent(s).
[0056] Vaccines may be formulated and/or prepared for parenteral, mucosal, oral and/or transdermal administration. Vaccines and/or immunogenic compositions for parenetral administration may be administered interdermally, intraperitoneally, subcutaneously, intravenously or intramuscularly.
[0057] The inventors have determined that the vaccines provided by this invention, particularly vaccines comprising the modified Streptococcus organisms described above, have a number of advantages over existing vaccines. In particular, vaccines comprising the modified Streptococcus strains of this invention, exhibit superior efficacy, as the enhanced expression of virulence factors improves immune reactions within the animal or human host and need to improve protective immunity.
[0058] Moreover, production of the vaccine is simple and requires established, defined and well understood (i.e. standard) culture conditions. Additionally, by avoiding the need to alter the culture conditions (relative to culture of, for example, a wild-type strain), vaccine production is safe, simple and rapid. Moreover, since the vaccine strain is used in a killed, whole-cell form, this further simplifies the production procedure and results in a safe vaccine which can readily be combined with other killed, whole-cell type vaccines, vaccines derived from portions and/or fragments of other microorganisms (for example toxoid vaccines) as well as other forms of medicament.
[0059] One of skill will appreciate that animal vaccines are subject to withdrawal periods—i.e. the period of time an animal (or products from an animal such as milk) cannot enter the human food chain following vaccination. The withdrawal period can hinder normal farming practises and result in lost production. It is not expected that a withdrawal period will be required with bacterin (comprising a suspension of killed wild-type or modified microorganisms) type vaccine.
[0060] Following vaccination with a whole-cell killed microorganism-derived vaccine, it is often difficult to distinguish vaccinated and infected subjects. This is particularly true where both the vaccine and wild-type strains of a particular microorganism produce antigens which may be used to detect the microorganism or diagnose an infection therewith.
[0061] As such, the modified microorganisms provided by this invention may be further adapted to permit detection in a sample. For example, the modified microorganisms may comprise a detectable marker which may be exploited in a diagnostic procedure to detect or confirm the presence of a modified microorganism of this invention. One of skill will appreciate that the presence of a detectable marker in a modified microorganism of this invention would permit the identification of hosts (human or animal) which have been vaccinated with any of the modified microorganisms described herein.
[0062] The modified microorganisms of this invention may be supplemented with one or more detectable factors. In one embodiment, the detectable factor may comprise a gene and/or protein encoding a detectable factor, wherein the gene and/or protein has been introduced to a modified microorganism described herein. Genes and/or proteins of this type may be referred to as “marker genes and/or proteins”.
[0063] By way of example, a marker gene and/or protein may be introduced or delivered to a microorganism by way of a vector (for example an expression vector) such as, for example, a viral vector or a plasmid. The introduction and/or delivery of vectors to the modified microorganisms of this invention may be achieved using standard laboratory cloning procedures including those detailed in Molecular Cloning : A laboratory Manual; Sambrook and Green, Cold Spring Harbor Laboratory Press.
[0064] One of skill will appreciate that modified microorganisms further modified to include some form of detectable marker may be identified and/or detected in samples by virtue of the detectable marker. In other words, a positive identification of the detectable marker in a sample may confirm the presence of a modified microorganism of this invention.
[0065] The detectable marker may comprise a gene and/or protein which has been modified or deleted from the genome of the modified microorganism—the gene and/or protein encoding a detectable factor. One of skill will appreciate that just as the presence of a particular marker from a sample may serve to verify the presence of a modified microorganism of this invention, the absence of a particular marker from a sample, or the prescence of a modified form of a particular marker from a sample, may also serve as a means to diagnose the presence of a modified microorganism of this invention.
[0066] Modified microorganisms of this invention may be further modified so as to not comprise, produce or express at least one detectable factor. In some embodiments, the detectable factor may form the basis of a standard diagnostic test.
[0067] The detectable factor may comprise or be an immunogenic protein. Advantageously, the detectable factor is one which forms the basis of a diagnostic test.
[0068] The invention provides a modified microorganism according to this invention, which modified microorganism comprises a further modification which renders it unable to express at least one other detectable factor.
[0069] One of skill will appreciate that provided the at least one other detectable factor is a factor which can be detected by some means—for example by immunological assays (for example ELISA) or molecular detection assays (for example PCR-based assays), it is possible to use the presence or absence of such a factor from samples provided or obtained from subjects to be tested, as a means of determining whether or not that subject is infected with a wild-type form of the modified microorganism (which would be expected to express the detectable factor), or has been vaccinated with the modified strain (which would have been modified to exhibit inhibited (or ablated) expression of the detectable factor). Being able to make such a distinction is important as it prevents vaccinates being mis-diagnosed as infected subjects.
[0070] The diagnostic factor may be a factor used to detect instances of infection and/or disease, caused and/or contributed to by wild-type strains of the modified microorganisms. Advantageously the diagnostic factor is an antigenic and/or immunogenic factor, and in some embodiments, the diagnostic factor may be a secreted factor.
[0071] The modified microorganisms provided by this invention may further comprise one or more detectable marker or reporter elements. The presence of such elements may further serve to distinguish vaccine strains from wild-type strains. Markers and/or reporter elements which are useful in this invention may include, for example, optically-detectable markers such as fluorescent proteins and the like.
[0072] One of skill will appreciate that while this invention relates to modified forms of Streptococci microorganisms, the teachings may be applied to other species (including species from other genera). For example, the term “modified microorganisms as used herein) may encompass modified Mycobacteria, for example modified M. tuberculosis , wherein the modified M. tuberculosis comprises a modified ideR gene and/or IdeR protein—the ideR gene and/or IdeR protein being a dtxR/DtxR homologue.
DETAILED DESCRIPTION
[0073] The present invention will now be described in detail with reference to the following Figures which show:
[0074] FIG. 1 . PCR verification of a Streptococcus suis ΔscaR mutant. Panel A: PCR using primers flanking the deleted portion of scaR allowed amplification of an expected full-sized gene fragment (1,066 bp) from the wild-type parent strain and a shorter fragment (654 bp) from the ΔscaR mutant strain, confirming the deletion was correct and of the expected size. Lanes are annotated as shown. Panel B: PCR using primers specific for an internal portion of scaR allowed amplification of the expected sized fragment (561 bp) from the wild-type parent strain and confirmed the absence of the equivalent sequence in the ΔscaR mutant strain. Lanes are annotated as shown. Panel C: PCR analysis of the pG + host9-encoded erythromycin resistance gene (˜800 bp) confirmed the absence of plasmid sequences from the ΔscaR mutant strain. Lanes are annotated as shown.
[0075] FIG. 2 . Western blot analysis of secreted proteins in a wild-type Streptococcus suis and isogenic ΔscaR deletion mutant. Strains were cultured in either THB or CDM before culture supernatants were TCA precipitated, separated by SDS-PAGE and then transferred onto Hybond ECL nitrocellulose membranes (Amersham Biosciences). Primary antibody (polyclonal IgG antibodies derived from convalescent pig serum following S. suis infection) was diluted 1:500 and rabbit anti-porcine IgG HRP conjugated secondary antibody (Sigma-Aldrich) was diluted 1:10,000. Immunodominant proteins were detected by ECL (Amersham-Biosciences) and images were captured using ImageQuant LAS4000 (GE Healthcare).
[0076] FIG. 3 : Shows the mean rectal temperature data over the study period. The control animals were injected with sterile phosphate buffered saline at Day 0 and 28, and the vaccinated group were injected with an adjuvanted bacterin vaccine derived from a scaR mutant of S. suis at the same times. All animals were challenged with a wild type S. suis strain on Day 42.
[0077] FIG. 4 . PCR analysis of the Streptococcus equi ΔtroR mutant strain.
[0078] Panel A: PCR with the primers ΔtroR_ext_fwd and ΔtroR_ext_rev, which flanked the deleted portion of troR, allowed amplification of an expected full-sized gene fragment (519 bp) from the wild-type parent strain (WT) and a shorter fragment (220 bp) from the ΔtroR mutant strain (ΔtroR), confirming that the mutation was correct and of the expected size. The recombinant plasmid pGh9-ΔtroR (Control) was included as a positive control. Panel B: PCR with the primers ΔtroR_int_fwd+ΔtroR_int_rev, specific for an internal portion of troR, allowed amplification of the expected sized fragment (253 bp) from the wild-type parent strain and confirmed the absence of the equivalent sequence in the mutant strain (ΔtroR). The recombinant plasmid pGh9ΔtroR (Control) was included as a negative control. Panel C: PCR with the primers pGh9_erm_fwd+pGh9_erm_rev, specific for the pG + host 9-encoded erythromycin resistance gene (erm; ca. 0.8 kb) confirmed the absence of this gene, and hence plasmid sequences from the mutant strain (LtroR). The recombinant plasmid pGh9ΔtroR (Control) was included as a positive control.
[0079] FIG. 5 . Western blot analysis of secreted proteins in a wild-type Streptococcus equi and isogenic troR deletion mutant (ΔtroR). Strains were cultured in VPB before culture supernatants were precipitated, separated by SDS-PAGE and then transferred onto Hybond ECL nitrocellulose membranes (Amersham Biosciences). Primary antibody (polyclonal IgG antibodies derived from convalescent horse serum following S. equi infection) was diluted 1:500 and rabbit anti-horse IgG HRP conjugated secondary antibody (Sigma-Aldrich) was diluted 1:10,000. Immune-reactive proteins were detected by ECL (Amersham-Biosciences) and images were captured using an ImageQuant LAS4000 (GE Healthcare).
EXAMPLE 1
Material, Methods and Results
General Molecular Biological Techniques and Targeted Allele-Replacement Mutagenesis
[0080] Routine molecular biological manipulations were conducted as described (Sambrook et al., 1989). Transformation of E. coli and Streptococcus suis with plasmid DNA was conducted using standard procedures (Fontaine et al., 2004; Sambrook et al., 1989). Oligonucleotide primers used for PCR are described in Table 2.
[0000] Construction of a scaR (dtxR-Like Transcriptional Regulator) Mutant in Streptococcus suis
[0081] A defined scaR mutant was constructed in Streptococcus suis type strain 9682 (DSMZ). In brief, 5′ (DNA fragment A comprising 559 bp of upstream flanking sequence up to and including the translational ATG start codon of scaR) and 3′ (DNA fragment B comprising 506 bp of downstream flanking sequence encompassing the translational TAA stop codon of scaR and subsequent downstream sequence) chromosomal regions flanking the scaR gene were amplified by PCR with Phusion polymersase (Fiinzyme) in accordance with the manufacturer's guidelines using the primers detailed in Table 2. A 12 bp complementary nucleotide overlap sequence was engineered into the internal reverse primer of fragment A (Table 2) and internal forward primer of fragment B (Table 2) to increase the specificity and efficiency of the final spliced PCR reaction. The resultant amplicons (fragments A+B) were then used as a DNA template in a third cross-over PCR reaction, and the resulting DNA fragment (Fragment C) was cloned into the temperature-sensitive allele-replacement plasmid, pG + host 9, by virtue of primer-encoded EcoRI restriction endonuclease recognition sites. The resulting construct was designated pGh9-ΔscaR. The wild-type Streptococcus suis strain was subsequently transformed with pGh9-ΔscaR and allele replacement was conducted in an equivalent manner to that described (Fontaine et al., 2003). Following the two-step mutagenesis procedure, bacteria were plated onto solid media and potential scaR mutants were screened and verified by PCR using the primers detailed in Table 2. As expected, these primers resulted in the amplification of a ca. 1006 bp fragment from the wild-type strain; however, the equivalent PCR product for the ΔscaR strain was ca. 654 bp shorter, confirming deletion of the chromosomal scaR gene ( FIG. 1 , panel A). Further verification using internal scaR primers confirmed that the scaR gene was absent in the mutant strain ( FIG. 1 , panel B). An additional verification PCR to test for the presence of the plasmid derived erythromycin resistance gene confirmed there was no plasmid present in the scaR deletion mutant ( FIG. 1 , panel C). Finally, the region spanning the deleted scaR gene was PCR amplified and confirmed by sequencing (data not shown).
[0000] TABLE 2 PCR mutagenesis and verification primers Primer purpose* Sequence (5′-3′) † Reference Amplification of scaR flanking regions scaR upstream flank F GG GAATTC GCTACAGCTACAGCTGACTTG This study scaR upstream flank R CGCTCAGCTTGTTTACATGAGAACTCGCTTT C scaR downstream flank F GAAAGCGAGTTCTCATGTAAACAAGCTGAGC This study G scaR downstream flank R GG GAATTC GACGAATGACGGATACTATC Screening and verification of scaR mutagenesis construct and deletion mutant pGh + 9 MCS screen F CCAGTGAGCGCGCGTAATACG This study pGh + 9 MCS screen F GGTATACTACTGACAGCTTCC scaR external screen F CACAGCCACTCTTGGC This study scaR external screen R GTCTTGCAGCCTTTAACC scaR internal screen F GAACTGGGTCAATTAGACC This study scaR internal screen R GAGCTCTTTGTCCTTGTAC pGh9 + erm screen F TGGAAATAAGACTTAGAAGC This study pGh9 + erm screen R CGACTCATAGAATTATTTCC *Forward primers are denoted F and reverse primers are denoted R † Underlined sequences denote EcoRI restriction sites
Immunological Detection of S. suis Secreted Proteins Using Porcine Convalescent Anti- S. suis Antibodies
[0082] In order to determine whether the abrogation of production of ScaR in the Streptococcus suis ΔscaR mutant affected the production, in vitro, of proteins normally produced in vivo during infection, a Western blot was performed using serum from a piglet challenged with Streptococcus suis . Both the scaRScaR mutant and wild-type parent strains were cultured in Todd-Hewitt Broth+1% (w/v) yeast extract (THB) or in a chemically-defined medium (CDM; Walker et al., 2011). Once mid-logarithmic growth-phase was reached, culture volumes were adjusted by measurement of absorbance at 600 nm, so that equivalent cell numbers were recovered for wild-type and mutant strains. Subsequently, cells were harvested by centrifugation and supernatant proteins were retained for further analysis. A known quantity of bovine serum albumin (BSA) was added in equivalent amounts to wild-type and mutant culture supernatants, which were then TCA-precipitated and dissolved in 1.5 M Tris-HCl (pH 7.5); the BSA subsequently served as an internal control to confirm equivalent recovery of proteins from wild-type and mutant supernatants following TCA precipitation. Equivalent volumes of wild-type and mutant-derived supernatant proteins were separated by electrophoresis through a 12% SDS-polyacrylamide gel and visualised by staining with Coomassie; equivalent amounts of BSA were observed between samples, however, several differences were observed between the secreted protein profiles of both strains (data not shown). These differences were further investigated by Western blot using polyclonal IgG antibodies derived from convalescent pig serum following S. suis infection. Results confirmed that the expression of numerous proteins was greater in the ΔscaR mutant as compared to the wild-type parent strain ( FIG. 2 ), and equivalent results were observed for both THB and CDM-cultured bacteria. It was therefore concluded that the abrogation of production of the DtxR-like protein, ScaR, in Streptococcus suis resulted in the de-repression of some genes which are normally repressed during culture in artificial laboratory media.
EXAMPLE 2
9.1 Summary of Study Design
[0083] A total of eighteen piglets of 4 weeks of age were sourced from a high health status farm and housed as two groups of nine. At approximately 4 weeks of age, a blood sample was collected from each animal then one group was administered phosphate buffered saline and the other administered a formalin killed suspension of the scaR-deficient S. suis strain adjuvanted with aluminum hydroxide by intramuscular injection. These procedures were repeated four weeks later on Day 28. On Day 42, two weeks post-booster vaccination, a blood sample was collected from each animal then they were administered 5 ml of 1% acetic acid by intranasal delivery followed 1 hour later by a 5 ml volume of the challenge material by intranasal delivery at a concentration of 2×10 8 cfu/ml. A clinical observation was carried out on the animals prior to challenge then as a minimum twice daily, for seven days. On Day 49 (or earlier if animals were euthanased early on welfare grounds) the animals were euthanased and a blood sample was collected. At necropsy samples of the brain and tonsils were removed for bacteriological assessment to determine whether the challenge isolate was present. A summary of the study design can be seen in Table 3.
[0000]
TABLE 3
Summary of Treatment Groups
Dosage/
Regime
Challenge
Concentration
End of
Group
No.
Treatment
Route
(Days)
(Day 42)
Volume
(cfu/ml)
Study
1
9
Phosphate
1 ml/IM
0 + 28
Streptococcus
5 ml
1.55 × 10 8
Day 49
buffered
suis ,
saline
Serotype 2
2
9
Vaccine
1 ml/IM
0 + 28
Streptococcus
5 ml
1.55 × 10 8
Day 49
suis ,
Serotype 2
IM = Intramuscular
Test Material
[0084]
[0000]
Name:
Streptococcus vaccine*
Dose Regime:
1 ml on two occasions (Day 0 and 28), 4 weeks
apart
Control
Name:
Sterile Phosphate Buffered Saline (PBS)
Dose Regime:
1 ml on two occasions (Day 0 and 28), 4 weeks
apart
*A defined scaR mutant constructed using Streptococcus suis type strain 9682 that has been formalin killed and adjuvanted with alhydrogel
Challenge Material
[0085]
[0000]
Name:
Streptococcus suis , Serotype 2
Method of Administration:
Intra-nasal
Anticipated Titre:
2 × 10 8 colony forming
units (cfu) total in 5 ml
Dose Regime:
5 ml on single occasion (Day 42)
Test Material Administration
[0086] On Day 0, the animals from Group 1 were administered 1 ml of the control material by intramuscular injection to the right neck. All animals from Group 2 were administered 1 ml of the vaccine by intramuscular injection to the right neck. On Day 28, the animals from Group 1 were administered 1 ml of the control material by intramuscular injection to the left neck. All animals from Group 2 were administered 1 ml of the vaccine by intramuscular injection to the left neck. A new needle and syringe was used for each animal.
Challenge Preparation
[0087] On Day 41, a microbank seed stock cryovial containing the challenge isolate was removed from −70° C. storage and placed in a pre-chilled (−70° C.±10° C.) cryoblock which was transported directly to a Microbiological Class 2 hood. Two beads were removed from the vial and streaked onto separate 5% Sheep Blood agar plates. The plates were incubated overnight for 23 hours at 37° C. Following incubation, plates were examined and confirmed as having growth consistent with that expected for the isolate. Colonies were removed from each plate and added to 4×3 ml of pre-warmed vegetable peptone broth (VPB) in bijou bottles to a turbidity of 1.5 McFarland turbidity units (McF) (density measured using a Densitometer, BioMerieux). Each 3 ml volume was added to 97 ml of pre-warmed VPB. The cultures were incubated for four hours at 37° C. on an orbital shaker set at 150 rpm. After incubation the turbidity of each culture was recorded (target was between 2.5 and 3.5 McF). 80 ml of one culture broth was removed and added to 120 ml of VPB to produce challenge material with a concentration of approximately 2×10 8 cfu/ml (1×10 9 cfu total in 5 ml). The challenge material was stored chilled prior to use (+2 to +8° C.). A sample of the pre and post challenge material (pooled challenge broth pre and post challenge) was used for the measurement of bacterial concentration.
Clinical Observations
[0088] On Day 42, clinical observations were conducted prior to challenge then as a minimum twice daily from Day 43 until the end of the study. Additional observations were conducted as necessitated by the condition of the animals. Clinical observations consisted of assessments of demeanour, behavioural/central nervous system changes and rectal temperature (° C.) according to a scoring system (see Table 4). Additional comments relating to behavioural or neurological issues were recorded as comments.
[0089] Pigs which were recumbent/moribund and/or showing signs of severe distress were euthanased immediately on humane grounds by intravenous/intraperitoneal administration of a lethal dose of Pentobarbitone Sodium BP, using a suitably sized sterile syringe and sterile needle.
Necropsy
[0090] On Day 49 (or as required following early euthanasia on welfare grounds), animals were euthanased by lethal injection. A gross pathological examination of each carcass was conducted. Samples were collected as detailed below (see “Tissue samples”.
Tissue Samples
[0091] At necropsy, tissue and brain samples were removed from each animal. Two samples were removed for each tissue type. One was placed in a container along with 10% formal saline for histopathological analysis, the second was placed in a sterile container for bacteriological assessment. All samples were removed using sterile forceps and scalpels to reduce risk of contamination between animals. The samples for bacteriological assessment were transported to the laboratory where they were processed on the day of collection as detailed below. The samples in formol saline were stored at ambient temperature prior to examination as detailed below under “Histological analysis”.
[0000] S. suis Culture from Tissue Samples
[0092] Each tissue sample was weighed, placed in a separate stomacher bag together with 9.0 ml of peptone water to provide a nominal dilution of 10 −1 and homogenised for 30 seconds in a Seward “Stomacher 80” set at high speed. The homogenate was poured into a sterile Universal Bottle labeled the 10 −1 dilution. A 20 μl aliquot of homogenate was diluted in 180 μl of peptone water in a sterile U-well micro titration plate to give a 10 −2 dilution. This dilution process was repeated until the homogenate was diluted to 10 −7 . Duplicate 10 μl aliquots of each homogenate dilution from 10 −1 to 10 −7 were placed on the surface of a well dried 5% sheep blood agar plate. After samples are dry the plates were incubated overnight (20 to 24 hours) at 37° C. (±2° C.). Plates were inspected for typical colonies of S. suis . If present, colonies were counted.
Histopathological Analysis
[0093] A total of ten sets of tissues (three from early deaths, four from controls and three from vaccinates were processed and examined following standard procedures
[0000]
TABLE 5
Summary of study schedule
Table 5: Study Schedule
Study Day
Procedure
Day 0 (Pre-Treatment)
Arrival, Blood Sample. Vet inspection
Day 0
Administration of Vaccine/Saline
Day 28
Blood Sample, Administration of
Vaccine/Saline
Day 42
Blood Sample, Clinical Observations, Pre-
Challenge Primer (Acetic acid)
Day 42 (+1 hour)
Challenge
Day 42-49
Clinical Observations
Day 49
Necropsy
Results
Rectal Temperature Data:
[0094] The rectal temperature data is summarised in FIG. 3 . There is a considerable difference between the mean rectal temperatures when the results for the controls and vaccinates are compared. During the period between Day 44 pm and Day 46 pm the difference between the groups is around 1° C. This period (between 2 and 4 days post challenge) is the peak period for infection and this is shown by the differences between the groups. A total of 27 individual observations of rectal temperatures in excess of 39.5° C. were recorded for the control animals compared to none for the vaccinates. On Day 46 am all of the control animals had temperatures in excess of 39.5° C.
Behaviour and Demeanour:
[0095] Only three animals (all from the control group) were recorded to have abnormal behaviour and demeanour during the study and all three animals were subsequently euthanased on welfare grounds. No vaccinate animals were observed to have any abnormal signs at any point during the monitoring period. On Day 45 (pm) Animal no. 0252 was observed to have tremors, was unsteady on its feet and appeared to be having fits, combined with a temperature of 39.7° C. On Day 46 at the morning clinicals, Animal no. 0254 was observed to be showing early signs of the disease with some lameness and minor tremors as well as a slightly depressed demeanour and a temperature of 40.4° C. Approximately 4 hours later, the animal had a temperature of 40.8° C., as well as a hunched appearance, tremors, unsteadiness and some seizures. The animal was euthanased on welfare grounds. On Day 47, Animal no. 0251 was observed to have a temperature of 40.4° C., was unable to rise, was fitting and was euthanased on welfare grounds.
Mortality:
[0096] The mortality rate in the vaccinate group was 0% (0 out of 9) compared to 33.3% (3 out of 9) in the control group.
Summary of Clinical Scoring:
[0097] No observations of any clinical symptoms were recorded at any stage in the vaccinate group. Only three of the control animals developed clinical symptoms following challenge, all of which were euthanased on welfare grounds. The remaining six animals in the control group all had rectal temperatures in excess of 39.5° C. on at least one occasion post challenge, suggesting that the bacteria was active within the animals, perhaps indicating a sub clinical infection, however none of these animals went on to develop clinical disease within the experimental timeframe.
Bacteriology
[0098] A summary of the bacterial findings is shown in Table 6.
[0000]
TABLE 6
Bacterial recovery from tissue samples
Brain Sample
Tonsil Sample
Animal No.
Group No.
(cfu/ml)
(cfu/ml)
0251
1
1.29 × 10 4
4.48 × 10 6
0252
1
1.67 × 10 6
2.92 × 10 6
0254
1
1.02 × 10 4
1.52 × 10 7
0256
1
0
2.29 × 10 5
0253
1
1.06 × 10 3
0
[0099] Streptococcus suis was recovered from both of the tissue samples collected from the three control animals that were euthanased prior to Day 49. A further 2 animals from the control group were also observed to have bacteria present in one tissue. The challenge bacteria could not be confirmed as present in any of the samples from the vaccinate group. The tonsil samples for the majority of the animals were heavily contaminated with other bacteria to relatively high levels and it is therefore not possible to confirm whether any of the challenge bacteria was present at lower levels. The brain samples were however clean with few if any, other bacteria present and these samples at least can be confirmed as S. suis free.
[0100] It is apparent from the data that in order for a full clinical disease to occur, sufficient numbers of S. suis must be present in the brain.
Histopathology
[0101] A total of 10 sets of samples (brain and tonsil samples from each animal) were examined. These samples consisted of 3 animals from the vaccinated group and 7 animals from the control group (three animals which were euthanased early and four animals which were euthanased at the end of the study, but had shown no signs of clinical disease other than a transient rectal temperature increase). The results of the examination are provided in Appendix 4a and 4b and are summarised below. The three animals from the control group that were euthanased on welfare grounds prior to the end of the study were all observed to have severe active sub acute or chronic active generalised meningitis with extension into the brain along with severe chronic active necro-superative tonsillitis. These signs are consistent with infection with Streptococcus suis . Of the remaining four control animals, two were observed to have a single small focus of lymphocytes present in the brain although this was not considered to be significant, the other two along with the three vaccinate animals had no significant lesions present in the brain. The tonsil samples for these seven animals (four controls and three vaccinates) were all active with large secondary follicles and tonsilar crypts containing necrotic material, macrophages and polymorphonuclear neutrophils with colonies of small bacterial cocci. In all cases however there was no evidence of infection in the brain and the tonsilar lesions were considered to be normal for conventionally raised pigs.
Discussion
[0102] The objective of the study was to determine whether the Streptococcus vaccine was efficacious in the control of an artificial Streptococcus suis challenge in pigs of approximately 10 weeks of age. The results of the study provide indications that the vaccine has efficacy in the prevention of the disease. No animals from the vaccinated group were observed to show any signs of clinical or sub-clinical disease during the study and all rectal temperatures stayed below 39.5° C. (considered to be the cut off for normality in pigs of this age) and no bacteria could be recovered from the tissue samples collected at post mortem. In comparison all of the control animals were recorded to have increased rectal temperatures during the study (indicative of infections or sub-clinical disease) on at least one occasion and three of them developed an acute clinical Streptococcus suis infection and were subsequently euthanased. The mortality in the control group was 33.3% and while this is not as high as had been anticipated (potentially due to animals of this age being better able to fight off the infection than younger animals), the results are still comprehensive.
[0103] The results show that the vaccine offered some protection against the challenge.
EXAMPLE 3 —STREPTOCOCCUS EQUI
Materials & Methods
Molecular Biological Techniques.
[0104] Routine molecular biological manipulations were conducted as described (Sambrook et al., 1989). Transformation of Escherichia coli and Streptococcus equi with plasmid DNA was conducted using standard procedures (Sambrook et al., 1989; Fontaine et al., 2004). Oligonucleotide primers used for PCR are described in Table 7.
[0000] TABLE 7 PCR mutagenesis and verification primers Primer name Description/purpose Sequence (5′-3′) † Amplification of troR flanking regions 5′-ΔtroR_fwd Amplification of 5′- CG GAATTC CTTTCACCTTCTAGGTAAATCACATCAATACC 5′-ΔtroR_rev troR and upstream GCACCCTGCGGTCTTATCCTTTACAATCCAGCCTTGTGC flanking sequence 3′-ΔtroR_fwd Amplification of 3′- GATAAGACCGCAGGGTGCATGATCACTTTGAGCTTATCC 3′-ΔtroR_rev troR and downstream CG GAATTC GTGATGTTGTTGTTGCTGATCGCTTGGTGTATC flanking sequence Screening and verification of troR mutagenesis construct and deletion mutant ΔtroR_ext_fwd Amplification of troR GCAGAGAGAATGAAGGTTTCTGCAC ΔtroR_ext_rev fragmen for mutant CTTCCTTATCTGCATAAGTGATGG screening. Primers anneal within region ΔtroR_int_fwd Amplification of CTATTATCTAACAGAGCAAGGGCAG ΔtroR_int_rev internal troR fragment TGTTTTGTTGATTTCGATTAGTGG for mutant screening pGh9_erm_fwd Amplification of TGGAAATAAGACTTAGAAGC pGh9_erm_rev pG + host 9 erm gene CGACTCATAGAATTATTTCC † Underlined sequences denote EcoRI restriction sites + Multiple Cloning Site (MCS)
Construction of a troR Mutant of Streptococcus equi.
[0105] A defined troR mutant (a partial, 358 bp, in-frame deletion of the troR gene, designated ΔtroR) was constructed in Streptococcus equi subspecies equi strain 4047 (obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures). Briefly, two DNA fragments were amplified from the S. equi chromosome by PCR using the primers 5′-ΔtroR_fwd+5′-ΔtroR_rev (Fragment A) and 3′-ΔtroR_fwd+3′-ΔtroR_rev (Fragment B); Fragment A comprised 708 bp of S. equi troR upstream flanking sequence, including the first 139 nucleotides of troR, while Fragment B comprised 680 bp of troR downstream flanking sequence, including the last 182 bp of troR (nucleotide positions 467-648 bp). An 18 bp complementary nucleotide overlap sequence was engineered into 5′-ΔtroR_rev and 3′-ΔtroR_fwd to increase the specificity and efficiency of a subsequent spliced PCR reaction. The resulting amplicons (Fragments A+B) were then used as DNA template in a third PCR using primers 5′-ΔtroR fw+3′-ΔtroR_rev, and the resulting DNA fragment (Fragment C) was cloned into the temperature-sensitive allele-replacement plasmid, pG + host 9, by virtue of primer-encoded EcoRI restriction endonuclease recognition sites, to create the recombinant plasmid pGh9-ΔtroR. The wild-type Streptococcus equi strain 4047 was transformed with pGh9-ΔtroR and allele-replacement mutagenesis was conducted as described previously (Fontaine et al., 2003). Following the mutagenesis procedure, bacteria were plated onto solid growth media and potential troR mutants were screened by PCR to identify the desired mutant. PCR with the primers ΔtroR_ext_fwd+ΔtroR_ext_rev, which flank troR, were used to confirm the presence of a deletion within the S. equi troR gene, as was evidenced by the amplification of a ca. 0.5 kb fragment from the wild-type strain and a ca. 0.2 kb fragment from the mutant strain ( FIG. 4 , Panel A). In addition, PCR with the primers ΔtroR_int_fwd+ΔtroR_int_rev, which amplify a ca. 0.25 kb region of troR which is absent within the deletion derivative, confirmed the absence of this region in the mutant strain ( FIG. 4 , Panel B). Finally, PCR using the primers pGh9_erm_fwd+pGh9_erm_rev, which amplify a portion of the erythromycin resistance determinant (erm) of pG + host 9, failed to detect this sequence confirming that the plasmid had been lost from the chromosome ( FIG. 4 , Panel C). The region spanning the deleted troR gene was then amplified by PCR and sequenced to confirm that the mutation was as expected (data not shown).
[0000] Immunological Detection of S. equi Secreted Proteins by Convalescent Serum from a Horse with Strangles.
[0106] In order to determine whether the abrogation of production of TroR in the Streptococcus equi ΔtroR mutant affected the production, in vitro, of proteins normally produced in vivo during infection, a Western blot was performed using serum from a horse that had recovered from strangles infection. Both the troR mutant and wild-type parent strain were cultured in TSE compliant Veggitone Vegetable Peptone Broth (VPB). Once mid-logarithmic growth-phase was reached, culture volumes were adjusted by measurement of absorbance at 600 nm, so that equivalent cell numbers were recovered for wild-type and mutant strains.
[0107] Subsequently, cells were harvested by centrifugation and supernatant proteins were retained for further analysis. A known quantity of bovine serum albumin (BSA) was added in equivalent amounts to wild-type and mutant culture supernatants, which were then TCA-precipitated and dissolved in 1.5 M Tris-HCl (pH 7.5); the BSA subsequently served as an internal control to confirm equivalent recovery of proteins from wild-type and mutant supernatants following TCA precipitation. Equivalent volumes of wild-type and mutant-derived supernatant proteins were separated by electrophoresis through a 12% SDS-polyacrylamide gel and visualised by staining with Coomassie Brilliant Blue stain; equivalent amounts of BSA were observed between samples; however, several differences were observed between the secreted protein profiles of both strains (data not shown). These differences were further investigated by Western blot using polyclonal IgG antibodies derived from convalescent equine serum following natural S. equi infection. Results confirmed that the expression of some proteins was greater in the ΔtroR mutant as compared to the wild-type parent strain ( FIG. 5 ) implying de-repression of target genes as a result of the genetic disruption of troR.
REFERENCES
[0000]
Fontaine, M C., Lee J J and Kehoe M (2003). Combined contributions of streptolysin O and streptolysin S to virulence of serotype M5 Streptococcus pyogenes strain Manfredo. Infect Immun 71(7): 3857-3865.
Fontaine M C, Perez-Casal J, Willson P J (2004). Investigation of a novel DNase of Streptococcus suis serotype 2 . Infect Immun 72(2):774-81.
Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989) Molecular Cloning : A laboratory manual, 2nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., pp 1.63-1.70.
Walker C A, Donachie W, Smith D G, Fontaine M C. (2011). Targeted allele replacement mutagenesis of Corynebacterium pseudotuberculosis. Appl Environ Microbiol 77(10): 3532-3535.
Sambrook, J. and Russell, D. W. 2001. Molecular cloning: a laboratory manual, 3rd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
Fontaine, M. C., Perez-Casal, J. and Willson, P. J. 2004. Investigation of a novel DNase of Streptococcus suis serotype 2 . Infect Immun 72(2):774-81. | The present invention is based on the finding that microorganisms can be modified so as to express certain factors important in generating or raising host immune responses. In particular, the invention provides modified microorganisms which, when subjected to conditions which would be expected to suppress or reduce the expression, function and/or activity of certain factors, exhibit increased (often significantly increased) expression, and/or activity of those factors. The invention provides a modified microorganism capable of expressing at least one factor under conditions in which a wild-type (or unmodified) strain of the same microorganism, exhibits inhibited expression of the at least one factor. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to novel organic compounds, and more particularly it relates to novel liquid crystal compounds useful as a component of liquid crystal materials.
2. Description of the Prior Art
As well known, liquid crystal substances not only have been applied to display elements using nematic liquid crystals having a twisted liquid crystal arrangement (the so-called TN cell), but also have been broadly applied to display elements utilizing a guest-host effect of liquid crystals or mixtures thereof containing a suitable pigment, and further, DS type display elements utilizing a dynamic scattering effect of liquid crystals, display elements utilizing a cholesteric-nematic phase transition of liquid crystals, DAP type display elements utilizing an electric field-controlling birefringence effect of liquid crystals, etc. At present, however, no single compound is existent which satisfies by itself these characteristics i.e. liquid crystal temperature range, actuation voltage, response properties, etc., and it is the present status that substances which are endurable to practical use to a certain extent have been obtained by mixing several kinds of liquid crystal compounds.
The object of the present invention is to provide compounds useful as a component constituting such superior, practical and stable liquid crystal compositions.
SUMMARY OF THE INVENTION
The present invention resides in:
5-substituted-2-(4'-substituted biphenylyl)pyrimidines and 5-substituted-2-[4'-(trans-4"-substituted cyclohexyl)phenyl]pyrimidines expressed by the general formula ##STR3##
wherein R 1 and R 2 each represent an alkyl group or an alkyloxy group having 1 to 10 carbon atoms and ##STR4## represents cyclohexane ring or benzene ring.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compounds of the formula (I) of the present invention are liquid crystal compounds having a very large anisotropy of refractive index, a low viscosity for three-rings compounds, a comparatively broad liquid crystal temperature range and a superior stability.
The compounds of the present invention have a superior compatibility with other liquid crystal compounds; hence when they are mixed with compounds of liquid crystals of one to several kinds of groups such as biphenyl group, ester group, azoxy group, cyclohexanecarboxylic acid phenyl ester group, phenylcyclohexane group, phenylmetadioxane group, phenylpyrimidine group, etc., there can be exhibited effectiveness of improving various response characteristics, contrast and sharpness and also broadening their liquid crystal temperature ranges.
As for liquid crystal compounds having pyridine ring, those having two rings such as compounds expressed by the general formula ##STR5## wherein R 1 and R 2 each represent alkyl, alkyloxy, acyl, cyano, etc., have so far been known (see DE No 2,257,588, Japanese patent publication No. 55-6632 (G.B. No. 1,473,990), Japanese patent application laid-open No. 55-157,571 (G.B. No. 2,049,692), Japanese patent application laid-open No. 56-53661 (U.S. Pat. No. 4,311,610), etc.). However, any of such compounds have narrower liquid crystal temperature ranges than those of the present invention. Further, as for liquid crystal compounds of pyrimidine group having three directly linked rings, compounds expressed by the general formulas ##STR6## wherein one of R 1 and R 2 is CN and another is alkyl, alkyloxy, etc., ##STR7## wherein ##STR8## and R is alkyl, etc., and the like, have been known (Japanese patent publication No. 55-27056 (U.S. Pat. No. 4,062,798); Japanese patent application laid-open No. 55-104270 (G.B. No. 2,042,533, U.S. Pat. No. 4,273,929); Japanese patent application laid-open No. 57-95965 (G.B. No. 2,085,877).
However, these compounds necessarily contain CN group at one end of the molecules, in order to have a large Δε value; hence they have a smaller Δn value, a higher viscosity and a lower stability than those of the compounds of the present invention. Further the above-mentioned No. 57-95965 discloses liquid crystal compounds of pyrimidine group having three directly linked rings such as those expressed by the general formula ##STR9## wherein R 1 and R 2 each represent alkyl, etc., and ##STR10## However, if pyrimidine ring is positioned at the center of the three rings, two phases i.e. a smectic phase and a nematic phase, constitute a liquid crystal phase, whereas the compounds of the present invention exhibit only a broad nematic phase; hence they are practically superior.
Next, the preparation of the compounds (I) of the present invention will be described in detail. First, its outline will be illustrated by way of the following equations: ##STR11##
In the above equations, R 1 and R 2 each represent the same meanings as defined above.
First, a commercially available compound of the formula (II) having 4-substituted cyanophenyl group as a starting raw material is dissolved in an alcohol and toluene and reacted with HCl gas to obtain a compound of the formula (III) i.e. an imide ether hydrochloric acid salt derivative, which is then reacted with ethanol solution of NH 3 to obtain a compound of the formula (IV), i.e. an amidine hydrochloric acid salt derivative, which is then subjected together with a compound of the formula (V) i.e. an alkyl or alkyloxymalonic acid diethyl ester to a cyclization reaction in the presence of sodium methoxide, to obtain a compound of the formula (VI) i.e. a 2,5-substituted-4,6-dihydroxypyrimidine derivative, which is then chlorinated with phosphorus oxychloride to obtain a compound of the formula (VII) i.e. a 2,5-substituted-4,6-dichloropyrimidine derivative, which is then reduced with hydrogen in the presence of a paradium-carbon catalyst to obtain the objective compound (I).
The present invention will be described in detail by way of Examples.
EXAMPLE 1
Preparation of 5-hexyl-2-(4'-pentylbiphenylyl)pyrimidine
First step
Commercially available 4'-pentyl-4-cyanobiphenyl (102.2 g, 0.410 mol) was dissolved in anhydrous methanol (27.9 g, 0.87 mol) and toluene (100 ml) and the solution was purged by nitrogen gas with stirring at -5° C., followed by passing HCl gas (16.5 l) through the solution for 40 minutes and then agitating at -5° C. for 6 hours.
The reaction mixture was allowed to stand at -20° C. for 2 days to deposit crystals, followed by adding ethyl ether (30 ml), filtering and drying the crystals to obtain 4-(4'-pentylphenyl)phenylimide acid methyl ester hydrochloric acid salt (yield 104.5 g, 80%). M.P.: 231° C.
Second step
Ethanol (300 ml) was added to 4-(4'-pentylphenyl)phenylimide acid methyl ester hydrochloric acid salt (104.5 g, 0.329 mol) obtained at the first step, followed by further adding NH 3 -ethanol solution (15.9% by weight) (700 ml) with stirring, agitating the mixture at 30° C. for 5 hours, further allowing it to stand at room temperature for 2 hours, filtering, distilling off ethanol in the filtrate, filtering and drying deposited crystals to obtain 4-(4'-pentylphenyl)phenylamidine hydrochloric acid salt (yield: 86.2 g, 96.5%).
Third step
Metal Na (5.0 g, 0.217 mol) was added to anhydrous methanol (100 ml) to obtain sodium methoxide, to which were then added 4-(4-pentylphenyl)phenylamidine hydrochloric acid salt (20.0 g, 0.066 mol) obtained at the second step and n-hexylmalonic acid diethyl ester (16.2 g, 0.066 mol), under ice cooling and stirring, followed by refluxing with stirring for 8 hours, then ice cooling, adding 20% hydrochloric acid (150 ml), filtering precipitates, washing crystals with water and methanol and drying to obtain 5-hexyl-2-(4'-pentylbiphenylyl)-4,6-dihydroxypyrimidine (yield: 26.2 g, 95%).
Fourth step
To 5-hexyl-2-(4'-pentylbiphenyl)-4,6-dihydroxypyrimidine (26.2 g, 0.063 mol) obtained at the third step were added phosphorus oxychloride (150 ml) and N,N'-diethylaniline (25 ml), followed by refluxing for 30 hours, then distilling off excess phosphorus oxytrichloride, pouring the reaction mixture while hot into an ice-cooled 10% aqueous solution of NaOH (500 ml), extracting the reaction mixture with toluene (200 ml), washing the toluene layer with 20% hydrochloric acid and water, then distilling off toluene, recrystallizing from n-heptane (100 ml) and drying to obtain 5-hexyl-2-(4'-pentylbiphenylyl)4,6-dichloropyrimidine (yield: 20.5 g, 72%).
Fifth step
To 5-hexyl-2-(4'-pentylbiphenylyl)-4,6-dichloropyrimidine (20.5 g, 0.0453 mol) obtained at the fourth step were added magnesium oxide (15.0 g), palladium-carbon (5%) (3.0 g), ethanol (200 ml) and water (15 ml), followed by causing the mixture to absorb hydrogen gas at room temperature till it was saturated therewith, filtering the reaction material, washing the residue with toluene, subjecting the toluene layer and the filtrate to distilling off, dissolving the residue in toluene (200 ml), washing the solution with 20% hydrochloric acid and 10% aqueous solution of NaOH, further washing with water till the liquid became neutral, distilling off toluene, and recrystallizing the residue from n-heptane (200 ml) to obtain the objective 5-hexyl-2-(4'-pentylbiphenylyl)pyrimidine (yield: 11.5 g, 66%). This compound had a C-N point of 81° C., a N-I point of 164° C., a viscosity at 20° C. η 20 of 36 cp and a Δn of 0.25. The values of elemental analysis accorded well with the theoretical values as follows:
______________________________________ Observed TheoreticalElement values values______________________________________C 83.8% 83.89%N 8.8% 8.86%H 7.2% 7.25%______________________________________
EXAMPLES 2˜34
Other compounds of the formula (I) were prepared according to Example 1. Their values of physical properties are shown in Table 1 together with the results of Example 1.
TABLE 1______________________________________In formula (I) Values of physical properties No.Example R.sub.1 ##STR12## R.sub.2 (°C.)pointCN (°C.)pointNI (cp)η.sub.20 Δn Δε______________________________________ 2 C.sub.2 H.sub.5 ##STR13## C.sub.4 H.sub.9 91 161 30 0.27 8.5 3 " " C.sub.5 H.sub.11 105 167 32 0.27 9.2 4 " " C.sub.6 H.sub.13 83 155 27 0.25 7.9 5 C.sub.3 H.sub.7 " C.sub.2 H.sub.5 150 179 28 0.30 11.2 6 " " C.sub.4 H.sub.9 87 175 37 0.27 8.5 7 " " C.sub.6 H.sub.13 83 168 36 0.25 7.9 8 C.sub.5 H.sub.11 " C.sub.5 H.sub.11 77 173 35 0.24 -- 1 " " C.sub.6 H.sub.13 81 164 36 0.25 -- 9 " " C.sub.7 H.sub.15 124 168 37 0.27 --10 C.sub.7 H.sub.15 " C.sub.3 H.sub.7 81 168 29 0.27 7.911 " " C.sub.4 H.sub.9 63 157 29 0.25 7.212 " " C.sub.6 H.sub.13 97 157 35 0.24 6.513 C.sub.2 H.sub.5 ##STR14## C.sub.2 H.sub.5 115 158 43 0.19 6.514 " " C.sub.3 H.sub.7 100 173 30 0.19 3.915 " " C.sub.4 H.sub.9 91 159 48 0.17 4.516 " " C.sub.5 H.sub.11 91 162 26 0.18 3.917 C.sub.3 H.sub.7 " C.sub.2 H.sub.5 109 184 27 0.21 6.518 " " C.sub.3 H.sub.7 97 198 32 0.20 5.919 " " C.sub.4 H.sub.9 79 179 36 0.21 3.920 " " C.sub.5 H.sub.11 92 184 39 0.19 5.221 " " C.sub.6 H.sub.13 95 170 41 0.15 6.222 " " C.sub.7 H.sub.15 106 169 -- -- --23 C.sub.4 H.sub.9 " C.sub.2 H.sub.5 106 174 46 0.20 5.924 " " C.sub.3 H.sub.7 80 187 38 0.19 5.225 " " C.sub.4 H.sub.9 83 172 38 0.17 5.226 " " C.sub.5 H.sub.11 63 173 30 0.16 3.927 C.sub.5 H.sub.11 " C.sub.2 H.sub.5 116 178 33 0.18 6.528 " " C.sub.3 H.sub.7 101 187 38 0.19 5.229 " " C.sub.4 H.sub.9 79 175 33 0.19 4.530 " " C.sub.5 H.sub.11 73 177 44 0.19 3.931 C.sub.3 H.sub.7 O ##STR15## C.sub.2 H.sub.5 146 205 56 0.32 --32 " " C.sub.5 H.sub.11 132 204 -- -- --33 " " C.sub.6 H.sub.13 123 189 54 0.27 --34 " " C.sub.7 H.sub.15 101 191 47 0.25 12.2______________________________________
EXAMPLE 35
(Use example 1)
A liquid crystal composition A consisting of
______________________________________ ##STR16## 30 parts by weight ##STR17## 40 parts by weight ##STR18## 30 parts by weight______________________________________
had a N-I point of 52.4° C., a viscosity at 20° C. η 20 of 23.1 cp and a dielectric anisotropy Δε of 11.2 (ε.sub.∥ =16.1, ε.sub.⊥ =4.9). Further, when this composition was sealed in a TN cell of 10 μm thick, the resulting threshold voltage, saturation voltage and refractive index anisotropy Δn were 1.5 V, 2.0 V and 0.120 (ne=1.612, no=1.492), respectively.
When 5-heptyl-2-(4'-pentylbiphenyl)pyrimidine of Example 9 of the present invention (10 parts by weight) was added to the liquid crystal composition A (90 parts by weight), the resulting liquid crystal composition had a N-I point raised up to 61.5° C., a η 20 slightly raised up to 24.5 cp, a Δε of 11.0 (ε.sub.∥ =15.6, ε.sub.⊥ =4.6), a threshold voltage of 1.6 V, a saturation voltage of 2.1 V and a Δn raised up to 0.135 (ne=1.629, no=1.494).
EXAMPLE 36
(Use example 2)
5-Ethyl-2-(4'-(trans-4"-propylcyclohexyl)phenyl)pyrimidine (10 parts by weight) of Example 17 of the present invention was added to the same liquid crystal composition A (90 parts by weight) as used in Example 35. The resulting liquid crystal composition had a N-I point raised up to 63.1° C., a η 20 of 24.4 cp similar to that of the composition A, a Δε of 11.1 (ε.sub.∥ =15.7, ε.sub.⊥ =4.6), a threshold voltage of 1.5 V, a saturation voltage of 2.1 V and a Δn raised up to 0.130 (ne=1.624, no=1.494).
COMPARATIVE EXAMPLE ##STR19## which is a representative compound among high temperature liquid crystals having a large Δn value, currently used was added to the liquid crystal composition A (90 parts by weight) used in Examples 35 and 36. The resulting liquid crystal composition had a N-I point raised up to 66.7° C., a Δn raised up to 0.146 and also a η 20 much raised up to 27.5 cp.
Further, when the above mixing proportion was changed to 96.5 parts by weight of the liquid crystal composition A and 3.5 parts by weight of the above high temperature liquid crystal compound, the resulting liquid crystal composition had a η 20 of 24.5 cp, but its N-I point and Δn were reduced down to 57.6° C. and 0.129, respectively. | Novel organic compounds useful as a component of liquid crystal compositions are provided which compounds are 5-substituted-2-(4'-substituted biphenylyl)pyrimidines and 5-substituted-2-[4'-(trans-4"-substituted cyclohexyl) phenyl]pyrimidines expressed by the general formula ##STR1## wherein R 1 and R 2 each represent an alkyl group or an alkyloxy group having 1 to 10 carbon atoms and ##STR2## represents cyclohexane ring or benzene ring. | 2 |
This application is a continuation-in-part of U.S. Ser. No. 07/560,561, filed Jul. 30, 1990 now U.S. Pat. No. 5,158,103.
BACKGROUND OF THE INVENTION
The invention relates to a base assembly for a column structure, particularly to an unanchored, simply-supported base assembly which is prevented from overturning by the weight of a vehicular tire pressing down upon a base plate of the base assembly, pressing the base plate against the ground or other datum.
The invention is particularly adapted for temporary support columns which would remain securely in place as long as the vehicle, which provides the tire which holds the base plate down, is stationary at the site. Typical uses for such a base assembly would be for columns holding signage or awnings adjacent to an automobile at an automobile show; for supporting a banner or display on a column adjacent an automobile at an automobile sale lot; for supporting a shelter over a boat residing on a trailer, the trailer providing the tires which hold down the base assembly which supports the columns of the structure, or for erecting a temporary shelter, such as a tent, adjacent to, or over, a vehicle.
Temporary columns for displaying signage or holding awnings or canopies usually require that the column base plates be staked or otherwise anchored into the ground. Also, guy-wires directed from the top of the columns to adjacent areas where they are staked into the ground are sometimes used. These type of anchoring systems are more difficult to use, especially where the ground is an asphalt or concrete surface where stakes can not be easily driven. The present invention provides a base assembly which requires no penetrations of such hard surfaces.
SUMMARY OF THE INVENTION
The present invention provides for an easily manufactured and field assembled column structure adjacent to a vehicle.
Objects of the present invention are:
to provide an inexpensive and effective base assembly for securely erecting temporary columns;
to provide a base assembly which requires no staking into the ground to prevent overturning;
to provide a base assembly which can be broken down into small lightweight components which can be loaded into a small volume such as the trunk of an automobile;
to provide a convenient assembly for a table to hold tools or other articles adjacent to a vehicle;
to provide a convenient base assembly for erecting a tent adjacent to a vehicle;
to provide a convenient base assembly for erecting temporary signage on a hard surface area such as a parking lot;
to provide a convenient base assembly for erecting a canopy or awning arrangement over, or adjacent to, a vehicle;
to provide a convenient base assembly to hold a column adjacent to a vehicle, the column holding signage, lights, or loud speaker accessories; and
to provide a convenient base assembly for erecting a column an adjustable distance away from a cooperating vehicle tire.
The objects are inventively achieved in that a base assembly is provided which:
comprises a lightweight assembly easily manufactured and assembled, featuring a base plate and a vertical receiving tube attached to the base plate, the base plate laying flat on the ground with the vehicular tire resting on top of the base plate, the receiving tube thereupon upright for receiving a column therein with a set screw for locking the column inside the receiving tube;
comprises in one embodiment a table top which has an inverted receiving tube attached to a bottom of the table top and oriented downward, for receiving a top of the column therein, the table top providing a table surface for setting tools, or other articles, thereon for convenience while a user or mechanic is working on a car or performing other activities near to a vehicle;
provides a secure base assembly for erecting tents or awnings adjacent to a vehicle, where tent or canopy columns can be installed at each wheel on one side of a vehicle, forming columns from which the tent or awning can be erected outwardly, thus a tent or awning can be erected quickly and easily with a minimum amount of staking, which is beneficial in hard ground areas or rocky areas;
provides an easy method to install a temporary canopy structure over a vehicle wherein four such base assemblies can be utilized, one at each tire of a four tired vehicle, allowing for four upright columns from which can be constructed a box shaped canopy enclosure for the vehicle residing therein;
comprises in one embodiment, lugs and rings mounted to the base plate for attaching knee braces and guy-wires to laterally support tall columns;
comprises in another embodiment, a base plate held beneath a vehicle tire and a separate satellite base holding a column, the satellite base held in place by telescoping arms projecting from the base plate onto the satellite base, and the column reinforced against overturning by guy-wires from the column down to the arms;
provides horizontally arranged secondary receiving tubes for the secure holding of a horizontal pole projected away from the vehicular tire, this pole usable as a lower support or brace for signage or other structures;
Other objects and advantages of the present invention will become apparent upon reference to the accompanying description when taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the base assembly holding a column holding a table top adjacent to a vehicle;
FIG. 2 is a right-side view of the base assembly of FIG. 1;
FIG. 3 is a front-view of the base assembly of FIG. 1;
FIG. 4 is a front elevational view of a column structure using the base assembly of FIG. 1;
FIG. 5 shows an alternate use of column structure of FIG. 4;
FIG. 6 is a front elevational view of a second alternate use of the column structure of FIG. 4 using two vehicles and two column structures;
FIG. 7 is a front elevational view of a third alternate use of the column structure of FIG. 4 using at least two column structures, and using one vehicle;
FIG. 8 is a side elevational view of a fourth alternate use of the column structure of FIG. 4 using two base assemblies and two column structures and one vehicle;
FIG. 9 is a top plan view of an alternate embodiment of the base assembly;
FIG. 10 is a front elevational view of the base assembly of FIG. 9, and further showing in detail the awning assembly of FIG. 8;
FIG. 11 is a front elevational view of a second embodiment of the base assembly;
FIG. 12 is a front partial elevational view of a third alternate embodiment of the base assembly;
FIG. 13 is a perspective view of another embodiment of the present invention for a base and column structure;
FIG. 14 is a right side elevational view of the base and column structure shown in FIG. 13;
FIG. 15 is a top plan view of the base assembly shown in FIG. 13;
FIG. 16 is an enlarged partial perspective view of the base and column assembly of FIG. 13; and
FIG. 17 is a right side elevational view of the base and column assembly shown in FIG. 13, slightly modified.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a base assembly 10 held firmly to the ground by a tire 20, itself connected to a vehicle 24. The base assembly 10 holds a column 28 at its lower end, the column 28 holding a table top 30 via a coupling 32. The coupling 32 is connected to the table top 30, such as by welding (not shown). The table top 30 can hold a variety of articles such as a tool box 34.
The table top 30 provides a convenient and secure location for placing tools while a mechanic is working under the hood of an automobile, or a convenient and secure location for any articles which by their nature are used adjacent to a vehicle. The table top 30 can in fact be a duplicate of the base assembly 10 but installed in an inverted orientation. Thus, manufacturing a separate table top is eliminated with resulting cost savings with regard to duplication of parts. A user can purchase two base assemblies 10 and use them for erecting two columns (as described in detail below) or use the respective second one inverted as a table top 30 as shown in FIG. 1.
The base assembly 10 comprises a base plate 40, a substantially flat plate, whereupon is connected a receiving tube 44 which holds a set screw 46. The receiving tube 44 is connected to the base plate 40, such as by welding at 48, or by any other known means. The receiving tube 44 is laterally supported by a first diagonal brace 50 and a second diagonal brace 52 which connect a top portion of the receiving tube 44 with the base plate 40. Also provided attached to the base plate 40 are receiving rings 56, 58 to be used for receiving guy-wires such as in the embodiment discussed later with respect to FIG. 4. A first lug 64 and a second lug 66 are also provided, attached to the base plate 40, for providing an attachment location for knee braces 88a, 88b also discussed with respect to FIG. 4. The base plate further provides a first tire guide 74 and a second tire guide 76 which help the vehicle driver roll the tire 20 onto the base plate in the proper location initially, and thereafter help in preventing slippage of the base plate 40 from beneath the tire 20. The first "bump" or feel tells the driver the tire 20 has passed onto the plate, and the second "bump" or feel from the second tire guide 76 tells the driver he is progressing too far, and off the base plate 40.
FIG. 2 shows the same elements as described with respect to FIG. 1.
FIG. 3 shows the same elements as described in FIG. 1, however the set screw is shown in more detail. The set screw 46 comprises a L-shaped screw member threadingly received inside a nut 84, the nut 84 welded to an outside of the receiving tube 44. By projecting the set screw 46 through the nut and through an aligned hole 44a through the receiving tube 44, and thereby abutting a forward end of the set screw 46 against the column 28, the column 28 is locked inside the receiving tube 44.
FIG. 4 shows another application of the invention. In this application, the base assembly 10 is also utilized with a column 28, and is held firmly in place by a tire 20. However, a pair of knee braces 88a, 88b (88b shown in FIG. 8) are utilized in a column structure 85. The knee braces 88a, 88b are attached to the column 28 at a clamp 90 and are attached at the base plate 40 at lugs 64, 66. The two knee braces 88a, 88b and the column 28 received inside the receiving tube 44 of the base assembly 10 form the column structure 85 having a tripod-arrangement which prevents tipping of the pole with respect to the horizontal plane.
The arrangement of FIG. 4 is shown utilized in conjunction with a tent 86. The tent shown is a typical military shaped tent having short sides 86a, 86b, front flaps 86c, 86d, sloping roof panels 87a, 87b, as well as a back portion not shown in this front elevational view. The back portion would typically be a solid fabric of a shape equivalent to the additive area of the two front flaps. The tent 86 is held upright by at least one guy-wire 100. The guy-wire is configured into a first segment 102, a second segment 104, and a third segment 106. The third segment 106 terminates at a stake 110 driven into the ground on a side of the tent 86 opposite the tire 20. The tent 86 comprises a horizontal beam 107 spanning from a front of the tent 86 to the back of the tent, and located in the corner formed by roof panels 87a, 87b. The tent 86 or column structure 85 provides a strut member 92 which connects the beam 107 with the column 28, using a strut clamp 93. Thus, at least one base assembly 10, at the tire 20 on the vehicle 24, in conjunction with a minimum amount of stakes, can effectively hold the tent erect. In the preferred embodiment the column structure 85 supports only a front end of the tent 86 with a duplicative column structure 85a supporting a rear end of the tent 86 (not shown). Additionally, duplicative guy-wire segments support the rear of the tent 86 in identical fashion with that shown in FIG. 4. The strut 92 would hold up a front end of the beam 107 and a duplicative strut 92a would hold up a rear end of the beam 107. Likewise, a second guy-wire 100a could be utilized on the duplicative column structure 85a to hold the beam 107, and hold the tent erect to a duplicative stake 110a. It is also readily apparent that each column structure 85, 85a could utilize two guy-wires attached to each base assembly 10 in a spaced apart fashion to provide lateral resistance to column overturning at each base plate 40.
FIG. 5 shows a second application of the base 10 and the column structure 85 wherein a single column structure can be utilized to hold accessories such as a loud speaker 120, a light 124 and/or a pennant 128.
FIG. 6 shows how two column structures 85, 85a engaged by two vehicle wheels 20, 20a can be utilized to hold a wire 142 between the two structures 85, 85a. The wire 142 could hold many items hanging therefrom, such as banners, signs, fencing, a volleyball net, etc. FIG. 6 shows that each column structure 85, 85a utilizes a diagonal guy-wire 102a spanning from a ring 56, 58 to a column clamp 130. As more clearly shown in FIG. 8, the use of two diagonal guy-wires 102a, 102b attached to spaced apart rings 56, 58 provides increased lateral overturning resistance. Column clamp 130 is a known type of collar clamp.
FIG. 7 shows another application of the invention wherein two column structures 85, 85a utilizing base assemblies 10 at a rear end of a vehicle, in this arrangement a boat-holding trailer 150, form a rear structural bent 152 of a shed 154. At a front end of the arrangement, two additional base assemblies 10 could be utilized with corresponding column structures to form an identical structural bent 152a (not shown). Thus, four columns are erected, one at each wheel of the vehicle 150. Side structure can be added to tie the two bents 152, 152a together and provide rigidity to the skeleton of the shed 154. The four columns hold a roof structure 170 which provides weather protection for the vehicle. Additionally, sides can be attached around the outside of the shed 154. A lightweight canvas, plastic or other appropriate material would well suit the temporary nature of this structure.
FIG. 8 shows another arrangement of the column structures 85, 85a. In this arrangement the column structures 85, 85a are utilized on the same side of an automobile, at each tire, to support the columns 28 which hold an awning 228 projecting away from the automobile 200. This arrangement can be utilized to provide a shady place to sit during various outdoor activities. The awning assembly is described further with respect to FIG. 10. The column structure 85 shows the use of the diagonal guy-wires 102a, 102b for column lateral stability.
FIG. 9 shows an alternate embodiment of the base assembly referred to as the satellite base assembly 300. In this embodiment, the satellite base assembly comprises a base plate 310 whereon is mounted tubular guides 314, 316. The tubular guides 314, 316 can have a variety of cross sections, but are substantially hollow with open ends 314a, 316a respectively. The tubular guides 314, 316 act in a fashion similar to the guides 74, 76 but serve another function as well. The satellite base assembly 300 comprises telescoping arms 320, 324 which structurally tie the base plate 310 to a satellite plate 350. The satellite plate 350 is shown in this particular embodiment as a round plate, but other shapes could also work. The telescoping arms 320, 324 have offset base portions 330, 334 which insert into the guide tubes 314, 316 respectively through the open ends 314a, 316a. The telescoping arms 320, 324 project from the base plate 310 outward to the satellite plate 350 and beyond. The telescoping arms "crisscross", with one telescoping arm 324 resting on top of the respective other telescoping arm 320. Additionally, the telescoping arms have extension arms 362, 364 which can be extracted outwardly to increase the overall length of the telescoping arms. At one end of the telescoping arms 320, 324 are attached guy-wire rings 370, 372 and at a remote end of the extension arms are attached additional guy-wire rings 366, 368. As shown more clearly in FIG. 10, a plurality of guy-wires are utilized to stabilize the column 28 against overturning. The guy-wires 380a and 382a are shown connecting guy-wire ring 372 to a column clamp 384 attached to the column 28 by a second set screw 390. Also, a guy-wire 382a is shown attaching the guy-wire ring 368 to the column clamp 384. Likewise, a guy-wire would attach the guy-wire ring 370 and 366 to the clamp 384. Thus, four guy-wires are utilized to provide a column 28 greatly resistant to overturning.
FIG. 11 shows a second alternate embodiment 400 of the base assembly wherein an elongated base plate 402 is provided with increased length so that a column 406 can be located in the front of the vehicle 24 rather than to the side. The elongated base plate 402 includes a bridge section 404 which the inventor anticipates will accomplish two functions. The bridge section 404 should help to reduce stresses in the base plate 402 caused by a high overturning moment near the connection of the base plate 402 and the receiving tube 44, and also should provide some flexibility for adjusting for ground height differences between the location of the tire 20 and the location of the receiving tube 44. Uneven surfaces can be more easily accommodated due to the inherent flexibility of the arcuate bridge portion 404.
The second alternate embodiment 400 of the base assembly utilizes a majority of the same components as the base assembly 10. The receiving tube 44 with the set screw 46 are utilized. The diagonal braces 50, 52 are also utilized (brace 52 not shown in FIG. 11). The knee braces 88a, 88b can be utilized as well as the diagonal guy-wires 102a, 102b (knee brace 88b and diagonal guy-wire 102b shown in FIG. 8). An alternate column 406 is shown in FIG. 11. The alternate column 406 is a telescoping column made up of a first column segment 406a and a second column segment 406b. The first column segment 406a has a greater diameter than the second column segment 406b, wherein the second column segment 406b can be telescopically received within the first column segment 406a. A set-clamp 408 serves two functions. First, the set-clamp 408 anchors the two knee braces 88a, 88b to the column 406. Second, the set-clamp 408 has a third set screw 408a which is threadingly received by the set-clamp 408, penetrates through a hole provided in the wall of the first column segment 406a and abuts, or alternatively also penetrates, the second column segment 406b. Thus, the telescoping column assembly provides a quickly assembled column which can be disassembled into relatively small components for storage in, for example, an automobile trunk. The guy-wires 102a, 102b are secured to the second column segment 406b at the guy-wire clamp 384 which is secured to the column with a second set screw 390.
FIG. 12 shows an alternate detail to the ring and lug configuration of FIG. 1. Rather than using a ring 56 and a lug 64, those two elements are combined in a single angle lug 420 wherein a first face 432 holds the knee brace 88a at a connection 424, and a second leg 434 has an aperture 436 therethrough to hold a knot 438 from the guy-wire 102a. This results in a simplification of the base assembly.
FIG. 13, FIG. 14 and FIG. 15 show another embodiment of the invention. A base plate 500 provides a first tire guide 502 and a second tire guide 504 attached on a top surface of a plate 506. Also attached onto the plate 506 is a retaining tube 508 arranged in an upright orientation. An outer tubular column 510 extends upward from the receiving tube 508. Knee braces 512, 514 extend from a connection 516 downward to spaced apart lugs 520, 522 respectively. The lugs 520, 522 provide a bolting connection 520a, 522a respectively. Extending downwardly from the receiving tube 508 are stiffening braces 526, 528 which are connected directly to tire guides 502, 504 respectively.
Attached on opposite lateral sides of the receiving tube 508 are a first horizontal receiving tube 530 and a second horizontal receiving tube 532. The horizontal receiving tubes provide through holes for holding eye bolts 536, 538 respectively.
As shown in FIG. 13, at least one of the horizontal receiving tubes 530 is used to secure a horizontal pole 540 extending outwardly from a vehicle 542.
The column 510 holds an inner column 550 which proceeds downward into the receiving tube 508 and can be locked in place by a set screw 552 shown in FIG. 15. The set screw 552 is threadingly engaged into a nut 554 itself adhered to the receiving tube 508, wherein the set screw 52 can protrude into the receiving tube 508. The inner tube 550 extends upward within the outer tube 510 and protrudes from a top open end 560 of the outer tube 510. An upper horizontal beam 566 is supported in cantilever fashion off of the inner pole 550. A sign 570 provides a loop 572 at a top end thereof which captures the beam 566. The sign 570 provides bottom eyelets 574a, b. A cord 580 is provided which is attached to the eye bolt 536, threaded through the eyelets 574a, b and extends downwardly to attach to a remote eye bolt 582 attached to an end of the horizontal pole 540. Thus, the sign 570 can be stretched between the horizontal beam 566 and the horizontal pole 540.
FIG. 16 shows the arrangement of FIG. 13 with a modification in that a lower pole 540' can be provided with a row of apertures 586 and a cord 580' can have an excess length with a hook 588 attached at an end thereof for engaging into a select aperture 586. A sign 570' can be provided with a near hole 590 and a remote hole 592. The cord 580' is threaded through the near hole 590 and extended across the lateral width of the sign and is threaded through the remote hole 592 and extends down to loop through the remote eye bolt 582 and thereafter to be hooked into the selected aperture 586 which brings the string 580' to a sufficient degree of tightness. The cord can be arranged exposed on a back side of the sign 570' between the holes 590, 592 or threaded through a pocket formed in the sign material.
FIG. 17 shows an additional modification to the arrangement of FIG. 13 wherein two horizontal lower poles are used. A second lower horizontal pole 598 protrudes from the second horizontal receiving tube 532 in parallel fashion to the horizontal pole 540. In this case, a sign 600 can comprise two faces 602, 604 which meet at the upper beam 566 and spread apart and while descending to the horizontal pole 54 and the second lower horizontal pole 598. The sign is looped around the upper beam 566 with a pocket 605. The sign can be attached below per the details of FIG. 13 or FIG. 16 with cords 580, 580' or alternatively can be provided with a loop arrangement, identical to the loop 572 used on the upper beam 566 but engaged to the horizontal pole 540 and second horizontal pole 598 respectively.
The configuration shown in FIG. 13-FIG. 17 provides various advantages. The set screw 552 is located protruding laterally of the vehicle rather than extending outwardly to reduce the risk of foot injury. The braces 526, 528 are connected to the tire guides 502, 504 respectively which adds strength to the plate and prevents bending along the area between the brace and the tire guides. Additionally, by locating the braces 526, 528 outside of the lugs 520, 522, the braces 526, 528 protect the lugs 520, 522 from being inadvertently run over by the auto tire. Additionally, the bolting connections 520a, 522a provide bolts 520b, 522b having clear width W which is lengthy enough to provide additional space laterally of the connection for the braces 512, 514 so that a cable or guide wire can also be attached there and extend upward to anchor the column.
The horizontal receiving tubes 530, 532 provide the additional advantage that a second plate 500 can be arranged facing a first base plate in mirror image fashion and the lower horizontal pole 540 and/or the second horizontal pole 598 can extend from one base plate to protrude into opposite horizontal receiving tubes 530, 532 of the facing base plate to create a horizontal pole supported at both ends between two laterally parked vehicles. This can be utilized for erecting large signage where the bottom of the signage can be securely anchored. Other uses are readily conceivable.
Additionally, the horizontal receiving tubes 530, 532 not only can be welded to the receiving tube 508, but can be welded to the braces 526, 528 at points 526a, 528a respectively. This increases the overall strength and rigidity of the unit.
The base assembly and included knee braces, struts and telescoping arms can be constructed of materials appropriate for the function. More heavy duty applications would require metals such as steel or aluminum, whereas other jobs can be accomplished using plastics or even wood.
Although the present invention has been described with reference to a specific embodiment, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims. | A column base assembly for erecting temporary column structures, a base assembly held firmly in place by a vehicular tire resting thereon. The base assembly provides an easily erected column structure usable in a variety situations where a temporary structure can be erected near to a parked vehicle, such as signs, lights, sheds, tents or awnings. The base assembly provides a vertical receiving tube for holding a column, and a horizontal receiving tube attached to the vertical receiving tube for holding a beam. The column and beam can be used in cooperation to hold signage or other accessories. The base assembly provides a sturdy and stable column base erectable on hard surfaces, eliminating the need for staking. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to manufacture of mineral wool-based acoustical ceiling tile.
PRIOR ART
Mineral wool-based acoustical ceiling tile is conventionally made in a wet felting process using Oliver or Fourdrinier machines, well known in the art. Mineral wool and binder have long been used to form acoustical ceiling tile. Mineral wool is used because it is relatively inexpensive and inert. Mineral wool is typically shipped from a site where it is manufactured to another site where it is used to manufacture acoustical ceiling tiles. Typically, the mineral wool is compressed in bales to reduce its volume to facilitate handling and shipment. A bale of mineral wool may be compressed to a density of at least 8 lbs. per cubic foot.
When compressed and bound into bales, individual mineral fibers become entangled with one another. Long established practice has been to open a bale and break it up with power rotated metal tines or fingers and to deliver the coarsely separated mass of fibers to a mixing tank. The density of the mineral fibers while quite variable due to the coarseness of the bale opening devices can be, by way of example, 5 to 6 lbs. per cubic foot. In the mixing tank, a high speed rotary impeller is used to open and separate the fibers while simultaneously mixing other constituents of the tile basemat to be formed. The conventional practice is to rely on the mixing paddle blades of the mixing tank impeller to detangle the mineral fibers since the fibers were to be received in the tank and the mixing blade was to be employed to disperse the other constituents through all of the water in the tank.
This procedure has been found, however, to have deleterious effects on the mineral wool. The circular mixing action has a tendency to roll the fibers into little balls or nodules that are of greater density than desired. Fiber breakage results in reduced strength in the finished tile and nodulation can reduce potential NRC (noise reduction coefficient) values due to a loss of porosity. The nodules do not interlock or co-mingle with the other constituents.
SUMMARY OF THE INVENTION
The invention is a process for making mineral wool-based acoustical ceiling tile with improved acoustical performance. The inventive process takes the traditional task of fully separating the mineral fibers in a water filled mixing tank and moves the task upstream where dispersion of the mineral fibers is accomplished mechanically in an air environment. It has been discovered that the mineral fibers can be successfully and sufficiently separated, as measured by bulk density of the fibers with mechanical devices operated in air and, optionally, with an air stream so that a ceiling tile with improved properties results. Less fiber bundling occurs when they are dispersed without significant agitation in a water mixing tank allowing the fiber content in a ceiling tile to be reduced without a loss of strength. The reduced fiber content, for a given caliper of a tile, results in greater porosity and, consequently, a higher NRC value. Also adding to the ability to decrease overall fiber content is a reduction or elimination of fiber nodules. Nodules are otherwise created by extended fiber mixing by a high speed water immersed impeller. The nodules are relatively dense and, therefore, do not contribute proportionately to sound reduction. Fiber separation in air upstream of the mixing tank can have the beneficial effect of reducing the content of shot, i.e. the un-fiberized portion, in a given volume of mineral wool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of a prior art process for preparing a dilute slurry of mineral fiber and binder for a wet felted acoustical ceiling tile;
FIG. 2 is a diagrammatic representation of an exemplary process for preparing a dilute slurry of mineral fiber in accordance with the invention; and
FIG. 3 illustrates a multi-station system for refined control of mineral fiber separation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Conventionally, in the manufacture of wet felted mineral wool-based acoustical tile, a dilute water slurry of mineral fiber and binder of starch and/or latex, and other minor amounts of solid components is used. The slurry is distributed from a mixing tank onto a travelling wire screen, sometimes simply called a wire. A mixing tank for the slurry is shown in FIG. 1 at 10 . It has been the practice to receive large bales 11 of mineral wool held in a compressed state by bands or otherwise from a manufacturer or other source. By way of example, a bale 11 may weigh 1000-1300 lbs. and the mineral wool in the bale can be compressed to a density, for example, of between about 60 and about 65 lbs. per cubic foot. Upon release of the constraining bands, a bale 11 will expand somewhat on its own. The loose bales 11 are conveyed to a bale breaking station 12 where spiked rolls grab and separate clumps 13 of mineral wool from the loose bale 11 . The clumps, separated from a bale 11 , are directed by the spiked rolls and or chutes (not shown) into the mixing tank 10 . The ordinary practice is to separate the clumps 13 of wool into loose fibers with a high speed impeller 14 that simultaneously serves to mix and suspend other constituents in the tank water.
The bulk density of the clumps 13 is approximately 5½ lbs. per cubic foot. In order to disperse the fibers of the mineral wool clumps 13 , a typical mixing time can range between about 12 and 15 minutes.
The impeller 14 tends to tumble the mineral fibers and induces the fibers to form tight balls or nodules. The fiber nodulation limits the strength of the tiles in which the fibers are incorporated. The fiber nodules diminish the potential sound absorption ability of the tiles since they decrease homogeneity.
Referring to FIG. 2 , there is depicted an example of the inventive process for effectively dispersing the fibers of mineral wool from one another prior to delivery into a conventional mixing tank 10 so as to eliminate the need for further fiber dispersing action in the mixing tank. Bales 11 of the character described above are released from their binding and carried along a path that ultimately delivers adequately dispersed mineral fibers to the conventional mixing tank 10 . The bales 11 are received at a preliminary opening station 15 where meshed spikes or tines 16 on counter-rotating rolls 17 separate the bale 11 into wool clumps or tufts 18 that are subsequently fed into a fiber separator 19 . The fiber separator 19 , by way of example, but not limitation, may be of the type disclosed in U.S. Pat. Nos. 4,111,493 and 4,978,252. The relatively dense small pieces or clumps 18 of the bales 11 are directed to a hopper 21 of the fiber separator 19 where they are circulated over and caused to fall through a hopper outlet 22 . The clumps 18 are received on a grid 23 (extending perpendicular to the plane of FIG. 2 ) of parallel bars. The mineral wool clumps 18 are converted into separated fibers by tines or spikes 24 on a rotating shaft 26 . The tines 24 pass through the plane of the grid 23 enabling them to operate on the clumps 18 . A second set of tines 27 on a shaft 28 meshes between the first set of tines 24 to further separate the fibers. The fibers are propelled downwardly by the tangential motion of the tines 27 and by gravity into a rotary pocket feeder 29 . Fibers delivered to a lower part of the feeder 29 are forcibly discharged pneumatically from the fiber separator 19 by compressed air at above atmospheric pressure to a conduit 31 .
The conduit 31 discharges into the top opening of the mixing tank 10 . The mineral fibers are dispersed to the degree that they have a bulk density of preferably about 2 lbs. per cubic foot, and most preferably between 1.2 and 1.0 lbs. per cubic foot.
Preferably, the tank 10 is filled with water and tile components including a binder of starch and/or latex and optional constituents such as expanded perlite, paper fiber, a filler such as clay, and glass fiber. Preferably, these constituents are premixed before the mechanically air dispersed mineral fibers are delivered into the mixing tank 10 . This premixing can minimize the exposure of the dispersed mineral fibers to the breaking and modulating effects of the mixer rotor or impeller 14 . Ideally, the mineral fiber slurry is discharged from the tank immediately upon a desired consistency being reached.
The slurry is discharged from the tank 10 onto a moving screen of a wet felting machine such as an Oliver or Fourdrinier machine.
The ability to adequately disperse the mineral wool fibers from the compacted wool bales 11 in an air environment such as by mechanical fingers and with an air stream to transport the fibers pneumatically to a state where they are sufficiently disentangled and dispersed has significant advantage in the manufacture of acoustical ceiling tile. The uniformity and separation of the mineral fibers by dispersion in air can result in a more open mat in a finished ceiling tile than has been practical to obtain by the water dispersion of the prior art.
Variations in the manner of dispersing mineral fibers in air for direct use in a water slurry without significant mixing in the water slurry are contemplated by the invention. Various arrangements using rotating, reciprocating and/or oscillating mechanical fingers or tines and/or air jets and/or air stream can be implemented in a path from a bale receiving station to a slurry mixing tank. These devices and expedients should reduce the density of the fibers to at least 2 lbs. per cubic foot before they are introduced to the mixing tank. An air stream can be provided by an air source operating above atmospheric pressure or a suction device operating below atmospheric pressure. While the relatively simple fiber separation system disclosed above has proven to obtain improvements in the performance of acoustical tile, it is expected that more elaborate air dispersion processes can be used with even greater success and higher throughput.
FIG. 3 illustrates a more extensive fiber separating system which can afford more control over mineral fiber separation than that afforded by the system of FIG. 2 . The system 36 comprises a number of stations that employ bale and fiber handling units that are commercially available from one or more manufacturers. A first station 37 provides a tipper unit 38 for an unbound bale 39 of compacted mineral fiber. The tipper unit 38 deposits the unbound bale 39 of mineral fiber onto a conveyor 41 of a bale opener 42 comprising the second unit of the system 36 . The bale opener 42 includes spiked rolls 43 that break the bale 39 down into uncompacted fibers. From the bale opener 42 the fibers are delivered to an auxiliary fiber separator unit 46 representing the third station of the system 36 . The auxiliary fiber separating unit 46 can reduce the shot content of the mineral fiber stream.
Fibers are delivered from a rotating paddle wheel 47 of the auxiliary unit 46 to a final or fourth station 51 . Fibers received in the fourth station are conveyed and elevated to a weighing hopper 52 at which well separated mineral fibers are collected until a predetermined weight or mass of such fibers is gathered. When the fiber weight reaches the predetermined level, the hopper 52 is opened to release the fibers into a mixing tank 53 which serves the same function as the tank 10 described in connection with FIGS. 1 and 2 above.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A method of forming a dilute water slurry for water felting a basemat for an acoustical ceiling tile comprising delivering a bale of compressed mineral wool with a density of at least 8 lbs. per cubic foot at an unbaling station, releasing a binding holding the bale in compression, mechanically separating the fibers of a mineral wool bale with mechanical instrumentalities arranged to disperse the fibers to a generally uniform density of less than 2 lbs. per cubic foot prior to passage of the fibers through the tank inlet, and causing the separated mineral fibers to pass into the mixing tank for contact with water suspended binder. | 4 |
FIELD OF THE INVENTION
The present invention relates to a novel use that has been discovered for smokeless powder tactical munitions type gun propellants of the single base and triple base varieties. In the present invention, military propellants of this type which have shown little, if any, commercial viability are used as blasting agents on their own. In the present invention, it has been shown that these propellants are detonatable and become novel commercial blasting agents exhibiting a favorable cost for performance.
BACKGROUND OF THE INVENTION
For many years, the most common disposal method of military propellants has been open burning/open detonation or incineration. Each of these methods are disposal techniques for explosive materials. These methods suffer from limitations, not the least of which is the fact that these methods create emissions problems and regulatory concerns. Moreover, the underlying propellant, which has potential use, is simply wasted in these processes.
A substantial quantity of the military propellant source is destined for demilitarization and destruction in the next few years. The incorporation of a military propellant into a packaged explosive product offers the most controlled, safe and environmentaly sound method of disposing military propellants. Moreover, the alternative use of stored military propellants as commercial blasting agents would be an extremely economical means of disposing military propellants and in the process, producing industrial explosives exhibiting a favorable cost for performance.
In general, there are three types of smokeless powder military gun propellants: single base, double base and triple base. Single base propellants are made essentially of a single explosive material such as nitrocellulose, generally in combination with stabilizers and other additives such as plasticizers, burning rate modifiers and flash depressants. Double base propellants generally contain, in addition to nitrocellulose, a secondary explosive such as nitroglycerine or another nitroester generally in combination with one or more additives as described above. Triple base propellants, on the other hand, generally contain, in addition to nitrocellulose, substantial quantities of two other high explosives, such as nitroglycerine, nitroguanidine and HMX, among others generally in combination with one or more additives as described above.
Commercial explosives or blasting agents are used throughout the United States in mining industries (coal mining, quarrying, non-metal and metal mining) and in construction. According to the U.S. Bureau of Mines (BOM). More than 4 billion pounds of commercial explosives are used yearly in the United States. Practically all commercial explosives are presently based on ammonium nitrate.
OBJECTS OF THE INVENTION
It is an object of the invention to provide new blasting agents which incorporate quantities of readily available single base and triple base tactical munition type gun propellants.
It is also an object of the present invention to provide a method of making commercial blasting agents from readily available single base and triple base tactical munition type gun propellants.
It is a further object of the present invention to provide economical commercial blasting agents made from single base and triple base tactical munition type gun propellants.
It is yet another object of the present invention to provide an economical means of disposing of single base and triple base tactical munition type gun propellants without having to rely on traditional disposal methods.
These and other objects of the present invention may be readily gleaned from the description of the invention which follows.
SUMMARY OF THE INVENTION
The present invention relates to the unexpected discovery that the use of a composition consisting essentially of small grain single base or triple base propellant in combination with a detonator and a booster, results in a blasting agent which has considerable commercial value. The resulting blasting agent exhibits favorable cost for performance characteristics.
In the present invention, a single base propellant consists essentially of at least about 75% by weight of explosive nitrocellulose in combination with stabilizers and other additives such as plasticizers, burning rate modifiers, stabilizers, flash depressants, among others, which are present in minor amounts. A triple base propellant consists essentially of at least about 15% by weight of nitrocellulose in combination with at least about 10% by weight of a secondary nitroester and with at least about 25% (up to about 50-60%) by weight of a high explosive such as nitroguanidine, RXD, HMX, among others, generally, in combination with stabilizers and other additives such as plasticizers, burning rate modifiers, stabilizers, flash depressants, etc.
The single or triple base propellants as described above are combined with a detonator and a booster in order to produce a blasting agent. It is an unexpected result that the inclusion of a single base or triple base propellant as described above will detonate when combined with a detonator and a booster.
In another aspect, the present invention relates to a method for the disposal of tactical muntion type gun propellants which could otherwise become an environmental liability, by producing a blasting agent composition consisting essentially of a single base or triple base propellant in combination with a detonator and a booster.
DETAILED DESCRIPTION OF THE INVENTION
As used throughout the specification, the following terms are applicable to describe the present invention.
The term "single base propellant" is used to describe a propellant composition (smokeless powder tactical munition type gun propellant) which consists essentially of at least about 75% by weight of explosive nitrocellulose in combination with minor amounts of additives such as plasticizers, burning rate modifiers, stabilizers, flash depressants, etc. Single base propellants find general use in the present invention in combination with a detonator and a booster.
The following two compositions are representative of single base propellants which are useful in the present invention:
______________________________________ Composition #1 Composition #2Component Amount Amount______________________________________Nitrocellulose 85.00 + 2.00 90.00 + 2.00Potassium Sulfate 1.00 + 0.30 --Lead Carbonate 1.00 + 0.20 --Diphenylamine 1.00 + 0.20 1.00 + 0.20 - 0.10 - 0.10Dinitrotoluene 10.00 + 2.00 8.00 + 2.00Dibutylphthalate 5.00 + 1.00 2.00 + 1.00______________________________________
The term "double base propellant" is used to describe a propellant composition which consists essentially of at least about 50% by weight of explosive nitrocellulose and at least about 10% by weight of a secondary nitroester selected from nitroglycerine, diethyleneglycoldinitrate, among others, and with minor amounts of additives such as plasticizers, burning rate modifiers, stabilizers, flash depressants, etc. also included. In the present invention, double base propellants may be included along with single or triple base propellants as minor components in amounts which are less than about 50% by weight, and preferably less than about 30% by weight.
The following two compositions are representative of double base propellants which may be included as minor components in the present invention:
______________________________________ Composition #1 Composition #2Component Amount Amount______________________________________Nitrocellulose 77.45 ± 2.00 52.15 ± 1.50nitroglycerinee 19.50 ± 1.00 43.00 ± 1.50Ethylcentralite 0.60 ± 0.15 0.60 ± 0.15Barium Nitrate 1.40 ± 0.25 --Potassium Nitrate 0.75 ± 0.20 1.25 ± 0.25Graphite 0.30 ± 0.10 --Diethylphthalate -- 3.00 ± 0.50______________________________________
The term "triple base propellant" is used to describe a propellant composition which consists essentially of at least about 15% by weight of explosive nitrocellulose combined with at least about 10% by weight of a secondary nitroester and with at least 25% by weight of a high explosive such as nitroguanidine, RDX and HMX, among others, in combination with minor amounts of additives such as plasticizers, burning rate modifiers, stabilizers, flash depressants, etc. Triple base propellants find general use in the present invention in combination with a detonator and a booster.
The following two compositions are representative of triple base propellants which may be used in the present invention:
______________________________________ Composition #1 Composition #2Component Amount Amount______________________________________Nitrocellulose 20.00 ± 1.30 28.00 ± 1.30nitroglycerinee 19.00 ± 1.00 22.50 ± 1.00Nitroguanidine 54.70 ± 1.00 47.70 ± 1.00Ethylcentralite 6.00 ± 0.30 1.50 ± 0.10Potassium Sulphate -- 1.00 ± 0.30______________________________________
The term "detonator" is used to describe a device which produces sufficient shock energy to produce a detonation of an explosive material. A detonator may be typically comprised of a blasting cap which contains an aluminum or other metallic shell and an explosive material (such as lead azide, pentaerythritolpentanitrate (PETN), among others). Connected to the blasting cap is generally a wire or fuse which will carry an energy impulse sufficient to ignite the match which, in turn, detonates the explosive material in the blasting cap. The detonator produces sufficient force generally in the form of a shock wave to initiate an explosion. In the present invention, the pressure generated by the detonator is sufficient to detonate the booster. Detonators for use in the present invention are standard in the industry and may be purchased from any number of suppliers of commercial explosive equipment including ICI Explosives, Dallas, Tex., Dyno Nobel, Salt Lake City, Utah, Austin Powder, Cleveland, Ohio and related companies.
The term "booster" is used to describe material which is found in proximity to the detonator and which contains sufficient mass to provide the energy necessary to initiate the detonation of the single base or triple base propellants which are found in the blasting agents according to the present invention. Typically a booster of a mass of at least about 1/6 pound up to about 5 pounds or more is used in the present invention and is sufficient to initiate the detonation reaction of the single and/or triple base propellant material. Typical booster materials include for example, a mixture of TNT and PETN (50/50 or 55/45 by weight), among other materials, including dynamite or other cap sensitive material. The booster is generally initiated with a suitable initiating device such as an electric or non-electric detonator or detonating cord.
The term "small grain" is used to describe the size of single or triple base propellant particles which are used in the instant invention. In one aspect according to the present invention, it has been discovered quite unexpectedly that combining a single or triple base propellant having a grain size of about 1/16 inch up to about 1 inch diameter, more preferably about 1/8 inch up to about 1/2 inch diameter, will produce an explosive material when combined with a detonator and booster. Single and triple base propellants which have grain sizes outside of this range may be incorporated as minor components (less than about 50% by weight) in the present invention.
The term "secondary nitroester" is used to describe compounds which are included along with nitrocellulose and high explosives in triple base propellants which are used in the present invention. Typical secondary nitroesters include nitroglycerine, diethyleneglycoldinitrate, among others.
The present invention relates to the unexpected discovery that single or triple base military propellants having a grain size ranging from about 1/16 inch to about 1 inch diameter, preferably, about 1/8 inch to about 1/2 inch diameter can be detonated when combined with a detonator and a booster. This novel blasting agent is commercially viable and inexpensive for use as a commercial explosive. Use of single base and triple base propellants as blasting agents according to the present invention represents a novel way of disposing of these military propellants in an economically efficient manner.
Explosive nitrocellulose for use in the present invention is a nitrated cellulose material having about 10.5% to about 14%, preferably about 12-13%, by weight nitrogen. In general, the single base propellants which are used in the instant invention contain at least about 75% by weight of explosive nitrocellulose, whereas the triple base propellants contain at least about 15% by weight nitrocellulose. Single base propellants may also include minor amounts of plasticizers, burning rate modifiers, stabilizers, flash depressants and other additives. These additives are readily recognized by those of ordinary skill in the art for the characteristics these additives instill in the final propellants when they are included in effective amounts. In addition, single and triple base propellants may also include minor amounts of double base propellants and other additives including lubricants, such as graphite, among others.
The novel blasting agents according to the present invention may be used directly or packaged in plastic, paper or other packing material. The single or triple base propellants of grain size which is appropriate for use in the instant invention, when packaged as dry material, results in a certain void volume (because of the uneven shapes and sizes). Preferably, the package is cylindrical with a diameter of about 1.5 inch or more. The blasting agents may be used with the propellant packaged in the dry state or alternatively, water or an aqueous salt or other solution or liquid may be added to the the packaged material to fill the void volume.
In using the novel blasting agents according to the present invention, the single and/or triple base propellant in grain form may be used directly by placing quantities into a blasting (bore) hole having a diameter sufficient to allow detonation to occur. In general, the blasting hole is at least about 2 inches in diameter, but may change as a function of the type of propellant used and its sensitivity.
The following example is provided to illustrate the present invention and should not be misunderstood or misinterpreted to limit the scope of the present invention in any way.
EXAMPLE 1
Use of Propellants as Blasting Agents
In an attempt to establish the feasability of using or recycling tactical munition type gun propellants in commercial explosives, the LKL propellant was purchased from the IOWA Army Ammunition plant. The LKL propellant was described as follows:
LKL M865F
Single Base Propellant Explosive
Diameter=9 mm
Length=10 mm
Heat of explosion=880 cal/gm
The propellant had the following formulation:
______________________________________Ingredients Weight %______________________________________Nitrocellulose(13.2 +- 0.1% N) 93.3 ± 2.5Dinitrotoluene 3.0 +1.5 or -0.5Dibutylphthalate 1.0 ± 0.3Diphenylamine 1.5 ± 0.3Potassium Sulfate 1.2 ± 0.3Graphite Glaze 0.2 max.______________________________________
The propellant was evaluated to determine whether or not it would detonate on its own as an explosive. The propellant was poured into cardboard tubes and primed with a one-half pound cast booster. The poured propellant proved to have an average bulk density of about 1.00 g/cc. A particle density of 1.55 g/cc was measured on the propellant pellets. The detonation tests showed that the LKL propellant was capable of detonating in a 4 inch unconfined charge. When water was added to the propellant column in the charge, the unconfined 4-inch VOD was increased from 20,000 ft.sec to 23,000 ft/sec. A similar VOD increase can be found when adding water to a column of Nitropel™ TNT (a prilled commercial blasting agent available from ICI Explosives).
In addition to the VOD tests, the LKL propellant pellets were evaluated for explosive energy in the underwater energy test. The LKL pellets were loaded into 6-inch diameter 1 gallon plastic jars and primed with one pound cast boosters. The pellets were shot both with air and with water filling the interstitial spaces between the pellets. These test data are given in Table I, below. For comparative purposes, Nitropel™ prilled TNT was shot in a similar package, both dry and wet.
TABLE I______________________________________Underwater Energy Test DataThese energy test data were measured on 6 inch diamaterunconfined charges (6 inch × 1 gallon jars for ANFO, TNT andstraight LKL propellant), that were primed with Trojan 1 poundcast boosters. The charges were shot at 25° C. The test data isas follows.______________________________________Product Density (Kg/m.sup.3 VOD (m/sec)______________________________________ANFO (STD.) 910 3,810LKL Dry 1010 6,100LKL Wet 1010 7,120Nitropel Dry 1000 4,880Nitropel Wet 1000 6,100______________________________________ Total Shock Bubble AvailableProduct Energy Energy Energy______________________________________ANFO (STD.) 348 519 867LKL Dry 405 456 861LKL Wet 467 446 913Nitropel Dry 399 460 859Nitropel Wet 460 470 930______________________________________
All of the above energy values are presented in calories/gram.
In these tests, the LKL single base propellant was found to be capable of detonating in a 4 inch unconfined charge with a VOD of 20,000 ft/sec dry and 23,400 ft/sec wet. In this condition, its density, velocity, and underwater energy values were comparable to that of Nitropel™ TNT prills, which indicated that the LKL pellets could be used as a substitute for Nitropel in toe-loading situations. | The present invention relates to the unexpected discovery that the use of single base or triple base propellant of small grain size in combination with a detonator and a booster, produces a blasting agent which has considerable commercial value. The resulting blasting agent exhibits favorable cost for performance characteristics. | 2 |
This is a Continuation Application of Ser. No. 189,635, filed Oct. 15, 1971, now abandoned.
BACKGROUND OF DISCLOSURE
This invention relates to a water permeable artificial lawn and particularly to an artificial turf surface for playing fields.
As is well known a natural lawn which is intended to be used as a game or playing surface for "outdoor" sports presents various difficulties resulting from changing climatic conditions. Excessive dryness destroys the lawn's surface and makes its maintenance costly and complex. Excessive rain softens the grass surface and makes it unfit for play or causes its destruction when a game is played on it. Moreover, a natural lawn used by professional sport teams may be used for only a limited number of consecutive games in order to keep it in good condition. Even lawns on which few games are played under relatively favorable climatic conditions show uneven wear so that it must be periodically renewed from the bottom up. In order to remedy the aforedescribed problems various artificial types of lawns have been developed by which it should be theoretically possible to play in any season, independent of the weather, not only two or at the most three days a week but without interruption.
However, it is a disadvantage of the known artificial lawns as for example, those described in U.S. Pat. Nos. 3,332,828, German Published Application DOS 1,933,048, and German Utility Model Patent 6,914,675 that they cannot be played upon after a rain because the residual liquid is released too slowly and then not completely. This disadvantage is due to the fact that the fibers which form the pile of the lawn are held together by a very dense base fabric or by a non-porous layer applied to the entire surface of the back of base fabric. Such layers normally consist of synthetic material such as polyvinyl chloride or a rubberlike mass which, in either case, makes the lawn impermeable to water or makes the fabric entirely waterproof.
It has also been proposed, for example, in the German Published Application DOS 1,534,383 to make an artificial lawn water permeable by making the base fabric of otherwise impermeable materials which can be perforated during or after drying by means of needles of suitable thickness. In such artificial lawns, however, it is difficult to maintain a secure anchorage of pile fibers in spite of the perforation of the materials. On the other hand mere water permeability of the base fabric does not produce the desired release of the water unless a very highly water permeable layer is provided below the base fabric since the water would only enter the holes in the fabric but would not find its way out. This occurs, because the known base fabrics are completely flat on their underside and thus prevent water which had passed through the holes or openings of the base fabric to flow away.
It is the object of the present invention to provide an artificial lawn or turf overcoming the disadvantages of the prior art.
It is another object of the present invention to provide an artificial lawn wholly permeable to water while simultaneously insuring that the pile yarns forming the surface are firmly held in the base fabric.
It is another object of the present invention to provide an artificial lawn having a basic carrier which permits the safe release of the water from its underside.
It is another object of the present invention to provide an artificial lawn which may be easily installed and which may be maintained in proper stretched and playing condition.
It is another object of the present invention to provide an artificial lawn playable in all seasons.
These and other objects together with numerous advantages will be apparent from the following disclosure.
SUMMARY OF THE INVENTION
According to the present invention an artificial lawn is formed comprising a base textile fabric, woven or knit with an open weave to which the pile yarns are secured; the fabric back formed with projections extending from the plane thereof. The base fabric is coated with an adhesive, resinous or similar holding material solely along the projections, leaving the open weave porous for drainage of water. Because the back of the textile base carrier is only partly coated the openings in the base carrier remain open so that the water may pass through them. On the other hand the coating of the back insures that the textile base carrier can be made of relatively loose weave to which the pile is firmly tied. Preferably the projections extending in parallel relationship and the partial coating of the backside, forms drainage channels, so that even when it is laid out on a flat non-porous surface the water passing through the lawn may run off.
According to the present invention a novel underliner or underlayer is provided having enhanced resiliency and improved porosity. The underline is made from a grid of foam ribbon or yarn like material, coated with a plastic which is allowed to drip off in its wet state, forming tear drop projections on the undersurface.
Also according to the present invention an improved method and apparatus for securing the lawn to the ground is provided comprising channel members having claws or barbs for gripping the underliner, and/or the base carrier including right angle corners and means for pressing the fabric against the barbs.
Full details of the present invention are set forth in the following description and in the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the attached drawings:
FIG. 1 is a cross sectional view of the lawn and its substructure, in accordance with the present invention:
FIG. 2 is an enlarged fragment of FIG. 1;
FIG. 3 is a view of a fastening rail;
FIG. 4 is a view of a segment similar to FIG. 2 showing a further embodiment of the fastening rail;
FIG. 5 is a perspective view of a section of the artificial lawn according to the invention, as viewed from above;
FIG. 6 is a perspective view of a section of artificial lawn according to the invention, as viewed from below;
FIGS. 7 and 8 show detail of the structure and method of forming base carrier and the pile of the artificial lawn;
FIG. 9 is a perspective view of an underline for the artificial lawn; and
FIG. 10 is a view corresponding to that of FIG. 6 which shows the preparation of the coating on the backside of the piece of lawn.
DESCRIPTION OF THE INVENTION
A general schematic view of an assembled playing field is seen in FIG. 1. The artificial lawn, according to the invention, is seen lying on a suitably flattened, solidified earth ground 2 on which a plurality of conically tapering concrete ribs 4 are placed. The concrete ribs 4 are spaced parallel to each other at generally predefined intervals and have a drainage bed built between and above them. Such a bed may as shown, comprise a lowermost layer 6 of coarse pebbles filled to the top of the concrete ribs, covered by successive layers 8 and 10 of varying degrees of granulate or particulate particles of sand, stone, rubber, plastic or other drainage filler material. Fastening rails 12 are mounted by suitable bolts, nails, screws, etc. on the upper ridges of the concrete ribs 4. An underliner of cushion 14 lies on the top side of the upper drainage layer 8, over which the artificial lawn of the present invention is located. The lawn comprises a textile base carrier 16 to which a pile 18 forming a turf surface is anchored. Carrier 16, pile 18 and, optionally, the underliner 14 are held in the fastening rails 12 as will be hereinafter described.
A lawn of the type shown in FIG. 1 when employed on a soccer, football or baseball field, insures that, regardless of the weather, a turf capable of being played on is always provided. There is no narrow limit to the period during which the turf may be used as is the case with a natural lawn, but it may be played on practically continuously. The layer of pebbles 6 is provided between the concrete ribs 4 so that the field may be drained by a ring or peripheral drainage system not shown. If the earth 2, on the other hand, is loose and absorbent, the concrete ribs 4 could be recessed in the soil, and the drainage layers 8, 10 could be layed directly on the soil surface.
With reference to FIG. 2 the details of the lawn anchorage is seen in a segment of the cross section of FIG. 1 depicted in the area marked by the circle A. The fastening rail 12 is formed in the shape of a U-channel, open in the upward direction, the interior of which is provided with pointed claws or barbs 20 which are directed obliquely downward. The barbs 20 are formed by triangular punched out portions of the rail wall as is best seen in FIG. 3, although other means such as nails, hooks etc. may also be substituted for the barbs. The punched barbs 20, however, provide drainage openings for water entering into the open end of the channel from above, permitting water to leave the channel rail 12 in a lateral direction.
The base carrier 16 on which the pile 18 is secured and the underliner 14, if desired, are hooked into the claw like barbs 20 in such a manner that the lawn can be securely anchored to the ground in a tensioned condition. In order to insure that the anchorage provided in this manner is perfectly secure and that the lawn will not loosen a safety element 22 is provided which may be wood, plastic or metal to fill the space remaining in the channel 12 after hooking of the lawn on the barbs. The safety element may be elongated to conform to the length of the rail, in any event it should be bulbous in cross-section to provide the degree of compression necessary for securing the lawn to the barbs 20. The safety element 22 forces the lawn substructure and/or underliner into the barbs 20, preventing the lawn from sliding off the barbs 20 and thus shifting when used. The safety element may be flared at its upper end, flattened and colored, thereby simultaneously serve as field markers, particularly at the periphery of the playing field. It may be provided with an axial socket in which a marker pole may be inserted. The safety element 22 may also be shortened, to be buried beneath, and thus covered by the pile 18, completely hiding these elements from view, if desired.
In order to prevent damage to the underliner 14 as it bends about the sharp upper edges of the fastening rail 12, the latter may be provided with rounded protectors 24 which, for example, may consist of resiliently yielding plastic or comparable material.
An other embodiment of the fastening rail is shown in FIG. 4. In this embodiment the rail corresponds to that seen in FIG. 2 in that it is also an upwardly open U-channel, but it differs in that it has offset side walls and an enlarged lower portion. In this fastening rail the underliner 14 and lawn 16,18 are first also hooked over barbs 20, but thereafter, rectangular clamping rails 26 are placed within the channel and pressed by suitably shaped safety elements 22 outwardly against the side walls of the enlarged lower portion of the fastening rail. This embodiment enables the fastening of end pieces of the lawn 16,18 or of the underlayer 14 and may be used to join two sections of turf together. The firmness of the anchorage of each of such end is enhanced by the fact that the artificial lawn is secured three times through an angle of 90° as it folds about the internal corners of the retaining rail. The clamping rails 26 and the safety element 22 may be provided with interengaging lips facilitating their joint insertion or removal.
FIGS. 5 and 6 are respectively top and bottom perspective views of a section of lawn. The design and formation of the lawn of the invention shall be explained in detail with reference to FIGS. 7 and 8. FIG. 7 shows a highly enlarged section of a Raschel knitted textile material in perspective view as it is obtained from a two-bed flat knitting machine of the Raschel type. In such a machine, two layers of the lawn of the invention are simultaneously prepared, the textile base material in FIG. 7 is designated by reference numeral 16,16', whereas the pile 18 connecting the two base layers is common to both. The pile-forming thread which is preferrably a strong plastic tape or ribbon, is emphasized by showing it in dotted shading while the thread forming the base structure 16,16' are shown without shading. The threads of the base structure are knit on the machine in a conventional manner to form what appears as a generally loose or open box like woven structure having crossing wefts 28,28' and warps 30,30'. The pile 18 is interlocked with the weft 28,28' as seen clearly in FIG. 6. Although not so indicated in FIG. 7 or 8, the weft yarns 28,28' should be substantially stronger or of larger diameter than the warp yarns 30,30' since they cooperate with the heavy pile tape to produce the reenforced structure illustrated in FIG. 6 and to form enlarged projections as will be explained later. After knitting the lawn in the conventional manner on the machine, the pile 18, between the base carriers 16 and 16' is cut so that two separate layers of the lawn are formed. Such a layer is shown, in bottom view, in FIG. 8, in which the pile for simplicity of representation is omitted with the exception of one loop 18, which loop, shows its securement to the base, and permits the flat tape shape of the pile to be seen clearly. The base carriers 16,16' are loosely knit so that relatively large openings 32 are formed between the grid of the weft in the base carrier 16. Well defined ridges 33 are also formed on the underside of the base by use of a strong weft yarn 28 and a strong pile 18 in combination with weaker warp 30.
The back of the base carrier 16, formed as described above, is then coated with a suitable adhesive or plastic material, in such a manner that only the ridges 33 (and perhaps also the weft 28) are coated to stabilize a grid-like structure. The openings 32 are left uncoated and thus open to the passage of water. The ribs formed by the coated ridges 33 have been indicated in FIG. 6 by reference numerals 34, whereas the coated weft continues to carry numeral 28 as in the other Figures.
The coating material which is preferably soft polyvinyl chloride, can be applied by means of a simple roller, because of the well defined back surface structure of base carrier 16,16'. If openings 32 should be plugged, for example, because of the flowing ability of the freshly applied coating material, it is only necessary to pull the textile carrier apart transversely to the ridges 33 or ribs 34, preferably at the time when the coating material starts to solidify to open the spaces. A tension frame 35 may be employed for pulling the fabric apart as indicated in FIG. 10, the arrow A showing the direction of pulling. This procedure may be effected prior to the final curing of the textile or coating under applied heat.
When the back of the artificial lawn of the invention is viewed as in FIG. 6, it is seen that channels are formed between the coated ribs 34. The ribs 34 are generally parallel to each other and thus the channels form longitudinal troughs for the collection and run off of water. While the cross sectional area of the ribs 34 is reduced at certain intervals by the weft 28, the ability of the channels to serve as a water run-off is not significantly impaired. It is further seen that the water entering from the surface of the pile can pass practically unimpeded through the uncoated openings 32 of the basic carrier. It is thereby insured that any water on the surface of the artificial lawn, not only reaches the underside of the basic carrier, but is also readily released through the channels into the soil bed. This will occur even if the lawn should lie atop an impermeable ground surface, as long as the lawn is layed out with a sufficient inclination to permit the water to flow through the channels.
FIG. 9 is a top perspective view of an underliner or cushion 14 for use with a lawn of the present invention. The underliner 14 consists in the illustrated example of core 36 of foamed material, perhaps of plastic or rubber in the form of a commercial grid-like, so-called anti slip mat. The foam core is provided with apertures 38 which extend between the two principal surfaces, i.e. between the top side and the under side, of the mat. In order to prepare the underliner 14, the perforated plastic or foam plastic mat, is dipped into a mass of soft plasticized PVC whose viscosity is selected in such a manner that the mat of the foam material is initially fully coated with the soft PVC. After the withdrawal of the mat, a surplus of PVC material collects on its bottom side and there solidifies to form tear drop-shaped projections 40. The other parts of the foam material mat, particularly its upper surface are nevertheless coated with a uniform, relatively thin layer of PVC, 42 and thus the entire mat is made water-impermeable.
The tear drop-shaped projections on the underside make the underliner particularly suitable for use with the aforedescribed artificial lawn since water passing through the lawn and guided in the channels between the ribs 34 can then easily pass through the openings 38 on to the top of the drainage layer 8,10. The space between the liner 14 and the top of the drainage layers 8,10 is enlarged by the point-shaped contact of the tear drops 40 and is sufficiently great, to permit safe and quick absorption and runoff even of large amounts of water, particularly when a suitable inclination of the subsoil is provided. The underliner 14, because of its shape, increases the resiliency of the lawn, and its cushioning effect, even though it consists only partly of foam material. Because of its water-proof coating, moisture or water can not be absorbed by it to remain on the underside of the lawn. This is particularly important when there is danger of freezing and the probability of ice formation. The fact, that ice formation, directly below the playing surface is prevented by the underliner of the present invention, is particularly valuable in a variable temperate or northern climate such as, for example, in Germany and the U.S. As is well known, in such areas the temperature may vary several times a day above and below the freezing point during the winter months. Consequently, when ordinary foam liners are used, the underground saturated with water during a period of thaw, remains moist and solidifies in a subsequent freezing period, impairing not only the elasticity of the artificial lawn, but rendering the playing field hazardous to the possible serious injury of the players. With the underliner 14 of the invention, no water can enter the coated foam plastic mat, so that the latter retains its elasticity and is not exposed to the danger of destruction as may have been the case when ordinary mats had been used.
A further improvement in the positive properties of the lawn of the present invention is achieved, when the underliner 14 is supported by an absorbent drainage bed, as is shown in FIGS. 1, 2, and 4. A drainage bed has been found particularly advantageous which consists of an upper layer 8 and a lower layer 10 which differ essentially by their grain size and the amount and the quantative relationship of their components. Preferrably, the upper layer of the drainage bed according to the invention, might consist of relatively fine pebbles, Bitumenous particles and relatively large amounts of rubber granulate, hardenable plastic and hardening or binder material. This layer not only has a certain elasticity which is necessary to imitate the properties of a natural lawn, but also permits the players to play in their accustomed manner. It also allows the behaviour of the playing ball to correspond to that on a natural lawn. Moreover, it is water=permeable. Because of its content of pebbles and rubber granulate material, cavities are formed, through which the water can run off. Moreover, the material for such a bed is relatively inexpensive, because rubber granulate can be made from regenerated old car tires, etc. and is cheap raw material. It has also been found that particularly good results are achieved with square or rectangular rubber pieces and polyurethane similarly formed. It has also been found useful to adhere, or permit the adhesive fastening of the underlayer 14 at their individual tear drop points with the hardened rubber or plastic material of the drainage layer. This reduces transverse load on the fastening members or rails 12 and absorbs the stress and tension given the lawn when played on. It has been, furthermore, found that the drainage bed of the described composition is suitable to receive heating elements 44 by means of which the run-off of molten ice and water can be accelerated and the surface rendered more resilient to use. It has been found particularly advantageous when cableshaped heating elements are employed, which are layed in previously formed grooves approximately in the middle between the drainage layer 8,10 or in grooves which are prepared by means of a preformed patterned matrix using a grid-shaped profile. When the heating element is embedded in the drainage layer in this manner, practically all of the heat generated will quickly reach the playing surface and not as in previously known systems which are heated by ground level devices, be dissappated by substantially heating the air. The advantages of the present mode of heating may be compared to the mode disclosed in German Patent 1534384.
The lower layer 10 of the drainage bed is built up in the same manner as upper layer 8, however, it contains coarser pebbles and less rubber granulate. This layer can be located directly on the underground or earthen bed if the soil is permeable, or, if the soil is impermeable, a layer of pebbles may be interposed therebetween as seen in FIG. 1. It will be understood that the selection of a drainage system may be chosen by those skilled in this art as can the selection of heating elements. Electrical cable heating means is, however, preferred.
The structure, according to the present invention, is not limited to this specific form shown but may be achieved in the most simple manner by selecting a textile base carrier having two yarn systems to which the pile is intimately tied. One yarn system consists of substantially thinner yarns than the other and are loosely woven or knit forming interstices or openings between the courses. By this measure the basic carrier is provided on its underside with projecting structures forming at least approximately parallel ribs which define horizontal drainage channels as well as transverse holes. The ribs further permit the base carrier and pile turf to be strengthened and permanently reinforced by coating them with a resinous, plastic material impervious to water, mildew, etc. without impairing the porosity and permeability of the spaces between course.
The adhesive binder may be applied by brush, roll coating, or similar techniques. If an excess of binder is applied, the spaces between courses can be easily opened by stretching or by pulling the base carrier after the binder starts setting or gelling.
It has been found that the lawn is most simply prepared and has the greatest advantages when produced as a Raschel-knitted textile. It is particularly economical to make two layers of a base carrier simultaneously on a two-bed flat knitting machine of the Raschel type and connect a common pile, which is later cut apart. In such a textile material strong loops of pile can be anchored to one of the yarns so that it increases the rib structure on the underside of the carrier. The pile is thus firmly anchored in spite of only a partial coating of the backside.
Suitable material for the pile of the lawn of the present invention can be chosen from such plastics as polypropelene and nylon whereas the material for the basic carrier may be the same or a polyester. The coating may be polyvinyl chloride dispersions or other suitable substitutes.
Although, as mentioned above, the lawn according to the present invention provides drainage troughs or channels on its underside suitable to permit flow of the water even on a water-impermeable smooth ground and thus can be used alone, it has been found advantageous to provide a water-permeable resilient drainage underliner of the present invention. The grid-like or web mat, of foamed material, is capable of being heated or immersed in a hot bath. The mat is itself coated with a water impermeable barrier or outer layer, permits the free flow of water through a large number of openings. The liner also is not absorbent and thus does not retain moisture. The liner furthermore has enhanced cushioning because of the tear drop or point-like projections which are also capable of adhesion to the drainage beds reducing the possibility of sliding or dislodgement under use.
Another advantage of the present invention is obtained through the use of a drainage bed having a high proportion (30-60% or more) of granulate and particulate rubber, plastic Bitumenous material. Such a drainage bed is highly porous, substantially resilient to the foot and thus quite similar to good natural ground. Moreover, such a bed in combination with the aforementioned underliner, prevents sliding of the lawn, the base carrier, or other substructure, thereby releasing lateral or transverse stresses in the anchorage of the lawn proper. The underliner can otherwise be of a very firm structure, such as the conventional anti-skid mats of foam material and carpet cushions which are a staple article of commerce.
It is preferred to make a composition of the underlying drainage beds consisting of pebbles, Bitumen, rubber and optionally of hardenable plastic and/or binder. The grain size of the pebbles should increase towards the bottom. One or more distinct laminae may be used for the beds, which may be layed directly on the ground, on a bed of coarse stone or rocks or may even be omitted if the sub-soil ground is sufficiently soft and porous itself. The drainage beds may be used with or without the cushion underliner.
Further advantages have been obtained from the novel structure of retaining rails in which both end pieces and continuous pieces of lawn may be anchored in stretched condition. The rails are made with openings at each end as well as lateral openings, allowing the water to flow outward freely. The rails may be easily secured to the ground, concrete ribs, or other sub-structure and should not be filled except with the lawn and retaining members.
It is to be pointed out that the materials mentioned for the individual components of the artificial lawn of the invention and its understructure, are only to be considered as preferred examples. They may be replaced by other materials having corresponding properties. It is further to be understood that the quality of the surface and base carrier of the artificial lawn of the invention may also be left to the expert who may have a field of free selection beyond that of the described preferred embodiments, as long as care is taken that a safe run-off of the penetrating water is provided. Various fastening means other than that disclosed may be used with the lawn, providing a safe anchorage of the lawn is obtained. Instead of concrete ribs for supporting the fastening rails, steel bars or alike may be employed. It is also possible to connect the fastening rails for example, at individual points only by suitable anchors with the soil underground base. Moreover, transverse ribs located between the heretofore described ribs, have been found useful as additional support, particularly in large playing fields, and may also carry fastening rails. In this manner the playing field may be divided into individually tensioned zones of turf. | An artificial lawn comprising a base textile fabric, woven or knit with an open weave to which the pile yarns are secured; the fabric back is formed with projections extending from the plane thereof. The base fabric is coated with an adhesive, holding material solely along the projections, leaving the open weave porous for drainage of water. A novel underliner or underlayer is provided having enhanced resiliency and improved porosity. An improved method and apparatus for securing the lawn to the ground is provided. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in an electric power steering apparatus which performs a steering force assistance in a manner of setting a motor current target value of a steering force assisting motor determined on the basis of a detected value of a steering torque as a target value of automatic control, and driving the motor according to a PWM control.
There is an electric power steering apparatus which drives a steering force assisting motor according to a PWM control on the basis of a motor current target value of the auxiliary motor determined based on a detected value of a steering torque, and a detected value of a driving current of the motor. In the electric power steering apparatus, when restoring a steering wheel, a restoration current of the steering wheel is supplied to the motor so as to perform a restoration control of the steering wheel. And then, the restoration current is set to "0 (zero)" when restoring the steering wheel to the vicinity of its neutral position (the middle point of steering angle) where a vehicle goes straight.
However, even if the steering wheel is restored to the neutral position, the rotation of the steering wheel does not immediately stop at the neutral position due to an inertial force of the motor. As shown in FIG. 1, the steering wheel repeats an operation like a pendulum such that it is over the opposite side of the neutral position (0°) and returns, and thereafter, converges at the neutral position. For this reason, it takes time until the steering wheel converges at the neutral position and stops, during this, a running state of the vehicle is unstable, in particular, a great influence is given to the vehicle when the vehicle is running at a high speed.
Moreover, even if the vehicle speed is the same, depending upon a steering state, there is the case where the restoration control is required, or the case where a convergence control of the steering wheel is required. For example, in the case where the rotation of the steering wheel is fast in the vicinity of the neutral position during medium vehicle speed, the convergence control is required. Also, in the case where the rotation of the steering wheel is slow in the vicinity of the neutral position during medium vehicle speed, it is the best to carry out the restoration control.
In order to solve the aforesaid problem, the present applicant has proposed an electric power steering apparatus disclosed in Japanese Patent Application No. 8-91341 (1996), together with other applicant.
In the electric power steering apparatus, a relationship between a vehicle speed, a steering angular velocity, restoration control and convergence control, is determined as shown in FIG. 2 which is a graph having an abscissa taking a vehicle speed, an ordinate taking an steering angular velocity. More specifically, the restoration control is possible when the vehicle speed is within the range of 0-30 km/h and when the vehicle speed is within the range of 30-80 km/h and the steering angular velocity is lower than 55°/s.
Also, the convergence control is possible when the vehicle speed is higher than 30 km/h and the steering angular velocity is higher than 60°/s.
In a region where the vehicle speed is within the range of 30-80 km/h and the steering angular velocity is within the range of 55°-60°/s, the steering angular velocity has a hysteresis when carrying out a change-over of the restoration control and the convergence control. When the previous control is the restoration control, the restoration control is carried out, and when the previous control is the convergence control or usual steering assisting control (assist control), the assist control is carried out.
In the aforesaid electric power steering apparatus, however, in FIG. 2, for example, in the case where the steering angular velocity is in a state of being higher than 60°/s and the vehicle speed oscillates around 30 km/h, the restoration control and the convergence control are alternately changed over in short time, there has arisen a problem that hunting occurs with the steering wheel.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made to solve the aforesaid problem in the prior art. An object of the present invention is to provide an electric power steering apparatus which can perform either preferable control of restoration control or convergence control on the basis of a vehicle speed and a steering angular velocity even in the same steering state, obtain preferable steering feeling, and quickly restore a steering wheel to its neutral position.
A motor current target value of the steering force assisting motor is determined on the basis of the detected value of the steering torque applied to the steering wheel, and the motor is driven in its rotation according to the PWM control so that the motor current becomes the target value. Further, when the steering torque detected value is within a predetermined range, a vehicle speed detected by a vehicle speed sensor is higher than a first vehicle speed and a steering angular velocity detected by a steering angular velocity detection means is higher than a first steering angular velocity, control of braking the motor is carried out. When the vehicle speed is lower than the first vehicle speed, and the vehicle speed exists between the first vehicle speed and the second vehicle speed and the steering angular velocity is lower than the first steering angular velocity, control of driving the motor and restoring the steering wheel to a predetermined steering angle, preferably the steering angle middle point between the two extremes of the steering angle is carried out.
In the electric power steering apparatus having the aforesaid function, the electric power steering apparatus of the present invention includes: means for continuously maintaining a state of carrying out control of restoring the steering wheel to the steering angle middle point when the vehicle speed is lower than a third vehicle speed which is lower than the first vehicle speed and becomes between the third vehicle speed and the first vehicle speed from a state of carrying out the control; and means for continuously maintaining a state of not carrying out the control when the vehicle speed is higher than the first vehicle speed, the steering angular velocity is higher than the first steering angular velocity, and the vehicle speed becomes between the first vehicle speed and the third vehicle speed from a state of not carrying out the control.
Therefore, it is possible to give hysteresis to the vehicle speed when making a change-over of the state of carrying out the restoration control and the state of carrying out the control of braking the motor, and to prevent hunting from occurring due to the restoration control of and the braking control. Therefore, preferable steering feeling can be obtained.
Further, another electric power steering apparatus of the present invention includes: means for continuously maintaining a state of carrying out control of returning the steering wheel to the steering angle neutral position when the steering angular velocity is lower than a second steering angular velocity which is lower than the first steering angular velocity and becomes between the second angular velocity and the first steering angular velocity from a state of carrying out the control; and means for continuously maintaining a state of not carrying out the control when the steering angular velocity is higher than the first steering angular velocity, and when the steering angular velocity becomes between the first steering angular velocity and the second steering angular velocity from a state of not carrying out the control.
Therefore, it is possible to give hysteresis to the steering angular velocity when making a change-over of the state of carrying out the restoration control and the state of carrying out the control of braking the motor, and to prevent hunting from occurring due to the restoration control of and the braking control. Therefore, preferable steering feeling can be obtained.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a view to explain convergence to a neutral position of a steering wheel according to a conventional electric power steering apparatus;
FIG. 2 is a chart to explain a relationship between a vehicle speed, a steering angular velocity, restoration control and convergence control of an electric power steering apparatus according to the prior application;
FIG. 3 is a block diagram showing a principal configuration of an electric power steering apparatus according to an embodiment of the present invention;
FIG. 4 is a flowchart showing control procedures of the electric power steering apparatus according to the present invention;
FIG. 5 is a flowchart showing control procedures of the electric power steering apparatus according to the present invention;
FIG. 6 is a flowchart showing control procedures of the electric power steering apparatus according to the present invention;
FIG. 7 is a chart showing characteristics of an absolute steering angle and a target current for restoring a steering wheel;
FIG. 8 is a chart to explain a vehicle speed coefficient value for calculating a target current value of a restoration current;
FIG. 9 is a chart to explain a duty ratio of PWM control for convergence control;
FIG. 10 is a chart to explain a vehicle speed coefficient value for calculating the duty ratio of PWM control for convergence control;
FIG. 11, which comprises FIGS. 11A, 11B, and 11C, is a chart to explain hysteresis in the case of carrying out a change-over of restoration control and convergence control, where FIG. 11A is to explain the hysteresis of a steering angular velocity while a vehicle speed is within the range of 30-80 km/h, FIG. 11B is to explain the hysteresis of a steering angular velocity while a vehicle speed is within the range of 20-30 km/hm, FIG. 11C is to explain the hysteresis of a vehicle speed while a steering angular velocity is higher than 60°/s;
FIG. 12 is a chart to explain a relationship between a vehicle speed, a steering angular velocity, restoration control and convergence control;
FIG. 13 a block diagram showing a principal configuration of the disclosed electric power steering apparatus;
FIG. 14 is a flowchart showing control procedures of the disclosed electric power steering apparatus; and
FIG. 15 is a flowchart showing control procedures of the disclosed electric power steering apparatus.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 3 is a block diagram showing a principal configuration of an electric power steering apparatus according to an embodiment of the present invention. In the electric power steering apparatus, a steering torque signal from a torque sensor 2 provided on a steering shaft 10 is compensated in a phase by means of a phase compensation unit 11, and then, is supplied to an assist control unit 12.
Further, a vehicle speed signal from a vehicle speed sensor 7 is supplied to the assist control unit 12, an angular velocity difference control unit 4, a restoration control unit 22, a steering angle middle point calculation unit 20, a duty determination unit 25 and a restoration current calculation unit 26. The assist control unit 12 outputs a target current value for assist control (steering assisting control) on the basis of a steering torque signal from the phase compensation unit 11 and the vehicle speed signal from the vehicle speed sensor 7, and then, supplies the target value to a comparison and selection unit 13. On the other hand, the steering torque signal from the torque sensor 2 is differentiated by means of an angular velocity difference detection unit 3, and then, the differentiated value is supplied to an angular velocity difference control unit 4. The angular velocity difference control unit 4 outputs a current value in response to the given differentiated value of the steering torque signal and the vehicle speed signal from the vehicle speed sensor 7, and then, supplies it to an adding unit 14. The current value is used for inertial compensation of a steering force auxiliary motor M.
When a motor rotational speed signal from a motor rotatory sensor 18 for detecting a rotational speed of the motor M is supplied to a relative steering angle detection unit 19, the relative steering angle detection unit 19 detects a relative steering angle of a steering wheel 1 on the basis of the motor rotational speed signal, and then, supplies it to the steering angle middle point calculation unit 20, a subtracting unit 21 and a steering angular velocity detection unit 24.
The steering angle middle point calculation unit 20 calculates a steering angle middle point of the steering wheel 1 in which a vehicle goes straight from the given relative steering angle, and then, supplies the calculated result to the subtracting unit 21. The subtracting unit 21 subtracts the given calculated result from a relative steering angle to obtain an absolute steering angle which is a steering angle from the steering angle middle point, and then, supplies the signal to a restoration control unit 22.
This embodiment has shown an example of detecting the relative steering angle on the basis of a rotational speed of the motor M connected to a steering mechanism. In place of the rotational speed of the motor M, for example, the relative steering angle may be detected in a manner of detecting a rotational speed of a steering shaft 10 connected to the steering wheel 1 with the use of a rotary encoder. Further, in place of the method of detecting the absolute steering angle with the use of a relative steering angle detected value, the absolute steering angle may be directly detected.
The restoration control unit 22 outputs a target current value of the motor M for restoring the steering wheel 1 on the basis of the absolute steering angle and the vehicle speed signal from the vehicle speed sensor 7, and then, supplies it to the restoration current calculation unit 26.
The restoration current calculation unit 26 multiplies the target current value obtained from the restoration control unit 22 by a vehicle speed coefficient in accordance with the vehicle speed to calculate a target current value of the restoration current, and then, supplies it to the comparison and selection unit 13.
The comparison and selection unit 13 makes a comparison in the absolute value between the target current value from the assist control unit 12 and the target current value from the restoration current calculation unit 26, and then, supplies a target current value having a larger absolute value to the adding unit 14.
The adding unit 14 adds a current value obtained from the angular velocity difference control unit 4 to the given target current value, and then, supplies the added result to the subtracting unit 15.
The subtracting unit 15 calculates a deviation between the added result from the adding unit 14 and a feedback value of a driving current of the motor M detected by a motor current detection unit 6, and then, supplies the deviation to a PI control unit 16. The PI control unit 16 adds the deviation (proportional element) and an integral value (integrating element) to the previous controlled variable, and then, supplies it to a PWM control unit 17 as a present controlled variable.
The PWM control unit 17 converts the controlled variable into a signal indicative of a PWM wave signal and a rotational direction of the motor M, and then, supplies the signal to a drive circuit 5. In the drive circuit 5, four FETs Q 1 , Q 2 , Q 3 and Q 4 is constructed so as to form a H-type bridge, and the motor M is provided on a bridging portion.
The steering angular velocity detection unit 24 detects a steering angular velocity which is a rotational speed of the steering wheel 1 on the basis of the given relative steering angle, and supplies it to the duty determination unit 25 as a steering angular velocity signal.
The aforesaid steering torque signal from the torque sensor 2 is also supplied to a dead zone detection unit 23. The dead zone detection unit 23 makes a detection whether or not the given steering torque signal exists in a dead zone of the assist control unit 12, and then, supplies the detected signal to the duty determination unit 25. In this case, the steering torque signal inputted to the dead zone detection unit 23 is a value before phase compensation is carried out. This is because the steering torque signal after phase compensation has a differentiating element; therefore, a chance for detecting a dead zone is decreased.
The duty determination unit 25 determines a duty ratio for PWM control of braking the motor M in accordance with the vehicle speed signal from the vehicle speed sensor 7, a dead zone detection signal from the dead zone detection unit 23 and the steering angular velocity signal from the steering angular velocity detection unit 24, and then, supplies the determined duty ratio to the PWM control unit 17. Braking of the motor M is carried out in order to quickly converge the steering wheel 1 at the neutral position when restoring the steering wheel 1.
The PWM control unit 17 short-circuits both terminals of the motor M in the drive circuit 5 so that a current by counter (back) electric force flows, according to PWM control on the basis of the duty ratio supplied from the duty determination unit 25 when a controlled variable supplied from the PI control unit 16 is approximately "0 (zero)" and the duty ratio supplied from the duty determination unit 25 is larger than a predetermined value.
The PWM control unit 17 does not carry out PWM control based on the duty ratio supplied from the duty determination unit 25 unless the steering angle of the restoration control unit 22 is at least within a range (e.g., -15° to +15°) of the dead zone.
A braking operation of the electric power steering apparatus thus constructed will be described below with reference to the flowchart shown in FIGS. 4, 5 and 6.
First, in the phase compensation unit 11, the steering torque signal from the torque sensor 2 is compensated in its phase (step S10).
Next, in the case where the vehicle speed signal from the vehicle sensor 7 is, for example, less than 20 km/h (step S12), in order to carry out restoration control for driving the motor M to return the steering wheel 1 to the neutral position, in the restoration control unit 22, a target current value is calculated on the basis of characteristics of an absolute steering angle and a target current for restoring the steering wheel 1, and then, the target current value is supplied to the restoration current calculation unit 26.
FIG. 7 is a chart showing characteristics of an absolute steering angle and a target current for restoring a steering wheel 1. The characteristics is as shown in FIG. 7; more specifically, when the absolute steering angles to right and left rotational direction are, for example, more than 15°, each target current for restoring the steering wheel 1 becomes a fixed ±1.8 A. When the absolute steering angles to right and left rotational direction are less than 15°, the absolute value of the target current gradually decreases from 1.8 A to 0 A in a range from -15° to -2°, and from -18 A to 0 A in a range from 15° to 2°.
The restoration current calculation unit 26 multiplies the given target current value by a vehicle speed coefficient to calculate a target current value of the restoration current (step S14).
FIG. 8 is a chart to explain a vehicle speed coefficient value for calculating a target current value of a restoration current. As shown in FIG. 8, the vehicle speed coefficient is 1.0 while a vehicle speed is within the range of 0 km/h and 15 km/h, and gradually decreases from 1.0 to 0 while the vehicle speed is within the range of 15 km/h and 80 km/h, and further, is "0" while vehicle speed is more than 80 km/h.
A convergence control flag is previously set, and in the case where the previous control is the convergence control for quickly converging the steering wheel 1 at the neutral position when restoring the steering wheel 1 (step S16), of four FETs Q 1 , Q 2 , Q 3 and Q 4 constituting an H-type bridge of the drive circuit 5, FETs Q 1 and Q 2 on a high voltage P side are turned off in their direction instruction (step S18).
These FETs Q 1 , Q 2 , Q 3 and Q 4 are individually in an "ON" state in their direction instruction, and when a PWM signal is given to them, these FETs Q 1 , Q 2 , Q 3 and Q 4 are turned on according to the PWM signal. When the convergence control is carried out, FETs Q 1 , and Q 2 are in an "ON" state in their direction instruction. Therefore, when the convergence control is not carried out, these FETs Q 1 and Q 2 are in an "OFF" state.
Subsequently, the convergence control flag is cleared (step S20).
When the convergence control flag is not set (step S16), turn-off of FETs Q 1 and Q 2 in their direction instruction (step S18) and clear of the convergence control flag (step S20) are not carried out.
When the vehicle speed signal from the vehicle speed sensor 7 is more than 20 km/h (step S12), if the dead zone detection unit 23 makes a detection such that the steering torque exists in the dead zone of the assist control unit 12 (step S34), in the duty determination unit 25, a steering angular velocity is read from the steering angular velocity detection unit 24 (step S36).
If the steering torque does not exist in the dead zone (step S34), a check is made whether or not the convergence control flag is set (step S16) without reading the steering angular velocity.
After read the steering angular velocity (step S36), when the vehicle speed signal from the vehicle speed sensor 7 is, for example, more than 30 km/h (step S37), a check is made whether or not the steering angular velocity read in step S36 is more than 60°/s (step S38). If the steering angular velocity read in step S36 is more than 60°/s (step S38), in order to carry out the convergence control, in the duty determination unit 25, a calculation for a PWM output calculated value=(steering angular velocity--60)×K×K p (step S40) is made to calculate a duty ratio of PWM control, and then, the duty ratio is supplied to the PWM control unit 17.
FIG. 10 is a chart to explain a vehicle speed coefficient value for calculating the duty ratio of PWM control for convergence control.
In this case, K is a control gain, and K p is, as shown in FIG. 10, a vehicle speed coefficient which gradually increases from 0 to 1.0 while the vehicle speed is within the range from 30 km/h to 120 km/h, and is 1.0 while the vehicle speed is more than 120 km/h.
FIG. 9 is a chart to explain a duty ratio of PWM control for convergence control. As shown in FIG. 9, the PWM output calculated value (duty ratio) gradually increases from 75% to 100% while the steering angular velocity is within the range from 60°/s to 114°/s, and becomes 100% while the steering angular velocity is more than 114°/s. In this case, in order to prevent the PWM output calculated value from exceeding 100%, limiter processing is carried out (step S42).
When the duty ratio supplied from the duty determination unit 25 is larger than a predetermined value, the PWM control unit 17 makes turn off the direction instruction FETs Q 3 and Q 4 on the ground side of the drive circuit 5 (step S44) so that FETs Q 3 and Q 4 do not become "ON" state according to the PWM control. Next, the convergence control flag is set (step S46), and then, an angular velocity difference control calculation (step S22) is executed.
When the steering angular velocity read in step S36 is less than 60°/s (step S38), the duty determination unit 25 is not actuated.
When the steering angular velocity read in step S36 is less than 60°/s (step S38) and the vehicle speed is more than, for example, 80 km/h (step S48), a check is made whether the convergence control flag is set (step S16), without actuating the restoration current calculation unit 26.
When the vehicle speed signal from the vehicle speed sensor 7 is less than 30 km/h (i.e., more than 20 km/h and less than 30 km/h) (step S37) or is less than 80 km/h (step S48) and when the steering angular velocity is less than, for example, 55°/s (step S50), in the restoration current calculation unit 26, the target current value supplied from the restoration control unit 22 is multiplied by the vehicle speed coefficient to calculate a target current value of the restoration current (step S14).
If the steering angular velocity is more than 55°/s (step S50) and the convergence control flag is not set (step S52), in the restoration current calculation unit 26, the target current value supplied from the restoration control unit 22 is multiplied by the vehicle speed coefficient to calculate a target current value of the restoration current (step S14).
If the convergence control flag is set and the previous control is the convergence control (step S52), of four FETs Q 1 , Q 2 , Q 3 and Q 4 comprising an H-type bridge of the drive circuit 5, FETs Q 1 and Q 2 on a high voltage P side are turned off in their direction instruction (step S18).
FIG. 11 is a chart to explain hysteresis in the case of carrying out a change-over of restoration control and convergence control. In this case, in steps S37, S38, S48, S50 and S52, when the vehicle speed is within the range of 30 and 80 km/h, as shown in FIG. 11A, when the previous control is the restoration control (calculation for the target current value of the restoration current) and the steering angular velocity is lower than 60°/s, the restoration control is continuously possible. As shown in FIG. 11A, when the vehicle speed is within the range of 30 and 80 km/h, if the previous control is the convergence control or assist control (control in which restoration control and convergence control are not carried out) and the steering angular velocity is within the range of 55 and 60°/s, angular velocity difference control is carried out. When the steering angular velocity is lower than 55°/s, the restoration control is carried out.
When the vehicle speed is within the range of 20 and 30 km/h, as shown in FIG. 11B, if the previous control is the restoration control and the steering angular velocity is more than 55°/s, the restoration control is continuously possible. As shown in FIG. 11B, when the vehicle speed is within the range of 20 and 30 km/h, if the previous control is the convergence control or assist control and the steering angular velocity is more than 55°/s, the angular velocity difference control is carried out. When the steering angular velocity is lower than 55°/s, the restoration control is carried out.
Further, when the steering angular velocity is more than 60°/s, as shown in FIG. 11C, if the previous control is the restoration control and the vehicle speed is within the range of 20 and 30 km/h, the restoration control is continuously possible. When the steering angular velocity is more than 60°/s, as shown in FIG. 11C, if the previous control is the convergence control or assist control and the vehicle speed is within the range of 20 and 30 km/h, angular velocity difference control is carried out.
Whereby it is possible to give hysteresis to the steering angular velocity and the vehicle speed when carrying out a change-over of the restoration control and the convergence control, and the restoration control and the braking control can prevent hunting from being caused.
FIG. 12 is a chart to explain a relationship between a vehicle speed, a steering angular velocity, restoration control and convergence control.
When the vehicle speed is within the range of 0 and 20 km/h and when the vehicle speed is within the range of 20 and 80 km/h and the steering angular velocity is lower than 55°/s, the restoration control is possible.
When the vehicle speed is higher than 30 km/h and the steering angular velocity is higher than 60°/s, the convergence control is possible.
In a region where the vehicle speed is within the range of 30 and 80 km/h and the steering angular velocity is within the range of 55 and 60°/s, and a region where the vehicle speed is within the range of 20 and 30 km/h, and the steering angular velocity is higher than 55°/s, the steering angular velocity has hysteresis when carrying out a change-over of the restoration control and the convergence control, and the restoration control or the assist control is carried out on the basis of the result whether or not the previous control is the restoration control.
Also, the angular velocity difference control calculation (step S22) and the following steps S23, S24, S26 and S28 are executed in any controls taking angular velocity difference control and continuity between the restoration control and the convergence control into consideration.
When the vehicle speed signal is less than 20 km/h (step S12), after clear of the convergence control flag (step S20) (unless the convergence control flag is set(step S16), after step S16), for inertial compensation of the motor M, the angular velocity difference control unit 4 calculates a current value in accordance with the differentiated value of the steering torque signal and the vehicle speed, and then, supplies the current value to the adding unit 14.
On the other hand, the comparison and selection unit 13 compares the target current value from the assist control unit 12 (step S23) and the target current value from the restoration current calculation unit 26 (step S14), and then, supplies the target current value having a larger absolute value to the adding unit 14.
In the adding unit 14, the target current value selected by the comparison and selection unit 13 and the calculated current value (step S22) are added together to calculate a motor current target value (step S24).
The subtracting unit 15 calculates a deviation between the motor current target value and the feedback value of the driving current of the motor M detected by the motor current detection circuit 6, and then, supplies the deviation to the PI control unit 16. The PI control unit 16 adds the deviation (proportional element) and an integral value (integrating element) of the deviation to the previous controlled variable (step S26), and supplies it to PWM control unit 17 as the present controlled variable.
Next, if the convergence control flag is not set (step S28), the PWM control unit 17 converts the controlled variable into a PWM wave signal and a signal indicative of a rotational direction of the motor M, and then, supplies them to the drive circuit 5 (steps S30 and S32).
The paired FETs Q 1 and Q 4 or the pared FETs Q 2 and Q 3 , which are in an "ON" state in their direction instruction, are turned ON/OFF according to the PWM wave signal, and thereby, the motor M is rotated according to the direction instruction, and the assist control or the restoration control is carried out.
If the convergence control flag is set (step S28), the direction instruction of FETs Q 1 , and Q 2 on high voltage P side of the drive circuit 5 is turned on (step S54), and then, the PWM wave signal based on the duty ratio (step S40) supplied from the duty determination unit 25 is supplied to the drive circuit 5 (step S34).
The paired FETs Q 1 , and Q 2 , which are in an "ON" state in their direction instruction, are turned ON/OFF according to the PWM wave signal. Whereby a circuit through which a current by a counter electric force generated by the inertial rotation of the motor M flows is formed according to the PWM control (both terminals of the motor M are short-circuited), and thus, the rotation of the motor M can be restricted by a braking force generated by the current (convergence control).
FIG. 13 is a block diagram showing principal configuration of the disclosed electric power steering apparatus. In the electric power steering apparatus, the steering torque signal from the torque sensor 2 provided on the steering shaft 10 is compensated in its phase by means of the phase compensation unit 11, and then, is supplied to the assist control unit 12.
The assist control unit 12 supplies a target current value of the motor M for assist control (steering assisting control) based on the steering torque signal from the phase compensation unit 11 to the subtracting unit 15 and a response delay compensation unit 12a.
The response delay compensation unit 12a is supplied with the target current value from the assist control unit 12, the steering torque signal from the torque sensor 2 and a detected current value of the driving current of the motor M detected by the motor current detection circuit 6. When the target current value and the detected current value are both "0", the response delay compensation unit 12a supplies an offset in response to a variation of the steering torque to a PID control unit 16a as the previous target voltage value.
The subtracting unit 15 calculates a deviation between the motor current target value and a feedback value of the driving current of the motor M detected by the motor current detection circuit 6, and then, supplies the deviation to the PID control unit 16a. The PID control unit 16a adds the deviation (proportional element), an integral value (integrating element) of the deviation and a differentiating value (differentiating element) to the previous target voltage value, and then, supplies the added value to the PWM control unit 17 as the present target voltage value.
The PWM control unit 17 converts the present target voltage value into a PWM signal and a signal indicative of a rotational direction of the motor M, and then, supplies these signals to the drive circuit 5. The drive circuit 5 is constructed in a manner that four FET Q 1 , Q 2 , Q 3 and Q 4 are formed into an H-type bridge, and the steering force assisting motor M is provided on a bridging portion.
Control procedures of the electric power steering apparatus thus constructed will be described below with reference to a flowchart shown in FIG. 14.
FIG. 14 is a flowchart showing control procedures of the disclosed electric power steering apparatus. The response delay compensation unit 12a first reads the target current value from the assist control unit 12 (step S60), and subsequently reads a detected current value from the motor current detection circuit 6 (step S62).
Next, the response delay compensation unit 12a makes a check whether or not the target current value and the detected current value are both "0" (step S64). If the target current value and the detected current value are both "0", the response delay compensation unit 12a reads a steering torque signal from the torque sensor 2 (step S65).
Subsequently, the response delay compensation unit 12a makes a check of a change direction of the steering torque indicated by the steering torque signal (step S66). If the change direction is right, positive target voltage offset is set (step S68), and then, the positive target voltage offset is supplied to the PID control unit 16a as the previous target voltage (step S70).
If the change direction is left, negative target voltage offset is set (step S76), and then, the negative target voltage offset is supplied to the PID control unit 16a as the previous target voltage (step S70).
The PID control unit 16a adds the deviation (proportional element) supplied from the subtracting unit 15, an integral value (integrating element) of the deviation and a differentiating value (differentiating element) to the previous target voltage value, and then, supplies the added value to the PWM control unit 17 as the present target voltage value (step S72), and thereafter, returns the present target voltage value as the previous target voltage value (step S74).
The PWM control unit 17 converts the present target voltage value into a PWM wave signal and a signal indicative of a rotational direction of the motor M, and then, supplies these signals to the drive circuit 5. The drive circuit 5 turns ON/OFF the paired FETs Q 1 , and Q 4 or the paired FETs Q 2 and Q 3 on the basis of the PWM wave signal and the signal indicative of a rotational direction of the motor M, and thus, the motor M is driven in its rotation.
The response delay compensation unit 12a makes a check whether or not the target current value and the detected current value are both "0" (step S64), and does not actuate when either desired current value or detection current value is not "0".
FIG. 15 is a flowchart showing control procedures of the disclosed another electric power steering apparatus. The electric power steering apparatus is constructed in a manner that the response delay compensation unit 12a of FIG. 13 has a target voltage offset value table in response to a steering torque variable indicated by the steering torque signal from the torque sensor 2. Other construction is the same as the aforesaid block diagram shown in FIG. 13; therefore, the details are omitted.
In the flowchart of FIG. 15, the response delay compensation unit 12a of the electric power steering apparatus reads a steering torque signal from the torque sensor 2 (step S65).
Next, the response delay compensation unit 12a calculates a difference between the previous torque value and the present torque value indicated by the steering torque signal as a torque variable (step S80). Subsequently, the response delay compensation unit 12a calculates a target voltage offset value corresponding to the calculated torque variable from the target voltage offset value table, and then, sets it as a target voltage offset (step S82).
Further, the response delay compensation unit 12a sets the present torque value as the previous torque value (step S84). Other procedures are the same as the aforesaid flowchart of FIG. 14; therefore, the details are omitted.
As described above, conventionally, when making a change-over of the driving direction of the steering force assisting motor M, if the target current value and the detected current value are both "0", a target voltage is set to "0" in current feedback control. For this reason, motor inertial compensation control is not sufficiently performed due to a response delay of calculation in fine steering region in the vicinity of a steering torque "0". However, in these disclosed electric power steering apparatus, it is possible to solve the above problem, so that response performance of steering control can be improved, and also, preferable steering feeling can be obtained.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims. | An electric power steering apparatus is disclosed in which steering return control is maintained when vehicle speed reaches a predetermined vehicle speed range after the vehicle speed has been lower than the speed range, and steering return control is disabled when the vehicle speed reaches the predetermined vehicle speed range after the vehicle speed has been higher than the speed range and steering angular velocity has been higher than a predetermined value. Therefore, the control state between the steering return control and convergence control can preferably be switched so that the steering wheel settles quickly to a steering angle predetermined point based on the vehicle speed and the steering angular velocity even while the steering state is not changing. | 1 |
BACKGROUND INFORMATION
[0001] 1. Field
[0002] The present disclosure relates generally to aircraft and in particular to a method and apparatus for controlling the flight of an aircraft. Still more particularly, the present disclosure relates to a method, apparatus, and computer program product for controlling thrust generated by the engine of an aircraft.
[0003] 2. Background
[0004] Takeoff is a phase of flight when an aircraft transitions from moving along the ground to flying in the air. An aircraft may make this transition when a takeoff speed is reached. The takeoff speed for an aircraft may vary based on a number of factors. These factors include, for example, air density, aircraft gross weight, aircraft configuration, and other suitable factors.
[0005] The speed needed for a takeoff is relative to the motion of the air. For example, headwind reduces the amount of groundspeed at the point of takeoff. In contrast, a tailwind increases the groundspeed at the point of takeoff.
[0006] The amount of thrust generated by an engine may affect the maintenance schedule required for an engine. For example, when crosswinds are present, the air into an inlet for an engine may separate. This separation of air may provide poor aerodynamics with respect to fan blades within the engine. If the engine is providing a high-level thrust, poor aerodynamics may cause vibrations on the fan blades.
[0007] These vibrations may result in requiring more frequent replacement or maintenance of the blades. This type of increased maintenance increases cost and makes the aircraft unavailable more often. One solution is to restrict engine power to a selected level until the forward speed is such that adverse aerodynamics at an inlet of an engine no longer occurs.
SUMMARY
[0008] In one advantageous embodiment, a method is presented for controlling thrust generated by an aircraft. A command is received for a selected level of thrust for the aircraft. A level of thrust provided by an engine for the aircraft is controlled based on a groundspeed and an airspeed of the aircraft in response to receiving the command.
[0009] In another advantageous embodiment, an apparatus comprises a thrust control process and a processor unit. The thrust control process may be capable of receiving a command for a selected level of thrust generated by an engine. The thrust control process may control a level of thrust provided by the engine based on a groundspeed and an airspeed of an aircraft in response to receiving the command. The thrust control process may execute on the processor unit.
[0010] In yet another advantageous embodiment, a computer program product for controlling thrust generated by an aircraft comprises a computer recordable storage medium, and program code stored on the computer recordable storage medium. Program code may be present for receiving a command for a selected level of thrust for the aircraft. Program code may also be present for controlling a level of thrust provided by an engine for the aircraft based on a groundspeed and an airspeed of the aircraft in response to receiving the command.
[0011] The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The novel features believed characteristic of the advantageous embodiments are set forth in the appended claims. The advantageous embodiments, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an advantageous embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 is a diagram of an aircraft in which an advantageous embodiment may be implemented;
[0014] FIG. 2 is a diagram of a data processing system in accordance with an advantageous embodiment;
[0015] FIG. 3 is a diagram illustrating a thrust control system in accordance with an advantageous embodiment;
[0016] FIG. 4 is a diagram illustrating a thrust control unit in accordance with an advantageous embodiment;
[0017] FIG. 5 is a diagram illustrating limits supplied to engine thrust in accordance with an advantageous embodiment;
[0018] FIG. 6 is a diagram illustrating limits for thrust in accordance with an advantageous embodiment;
[0019] FIG. 7 is a diagram illustrating limits for thrust in accordance with an advantageous embodiment;
[0020] FIG. 8 is a diagram illustrating logic for controlling thrust in accordance with an advantageous embodiment;
[0021] FIG. 9 is a diagram illustrating logic to generate or enable a groundspeed limit enable signal in accordance with an advantageous embodiment;
[0022] FIG. 10 is a diagram illustrating logic to generate an airspeed limit enable signal in accordance with an advantageous embodiment;
[0023] FIG. 11 is a high level flowchart of a process for controlling thrust generated by an aircraft in accordance with an advantageous embodiment;
[0024] FIG. 12 is a flowchart of a process for controlling thrust generated by an aircraft in accordance with an advantageous embodiment;
[0025] FIG. 13 is a flowchart of a process for enabling and disabling a groundspeed limit in accordance with an advantageous embodiment; and
[0026] FIG. 14 is a flowchart of a process for enabling and disabling an airspeed limit in accordance with an advantageous embodiment.
DETAILED DESCRIPTION
[0027] With reference now to the figures, and in particular, with reference to FIG. 1 , a diagram of an aircraft is depicted in which an advantageous embodiment may be implemented. Aircraft 100 is an example of an aircraft in which a method and apparatus for controlling engine power may be implemented. In this illustrative example, aircraft 100 has wings 102 and 104 attached to body 106 . Aircraft 100 includes wing mounted engine 108 , wing mounted engine 110 , and tail 112 . In particular, the different advantageous embodiments may control a level of thrust that may be generated by wing mounted engine 108 and wing mounted engine 110 when aircraft 100 is on the ground.
[0028] Although a wing mounted twin engine aircraft is illustrated in FIG. 1 , this illustration is provided for purposes of illustrating one type of aircraft in which different advantageous embodiments may be implemented. The different advantageous embodiments may be implemented on other types of aircraft with other numbers of engines and/or configurations of engines.
[0029] Turning now to FIG. 2 , a diagram of a data processing system is depicted in accordance with an advantageous embodiment. Data processing system 200 is an example of a data processing that may be implemented within aircraft 100 in FIG. 1 . Data processing system 200 may be found in various systems for aircraft 100 . For example, data processing system 200 may be implemented in components used to control the engines.
[0030] In these different advantageous embodiments, data processing system 200 may be configured to control the thrust generated by these types of engines. In this illustrative example, data processing system 200 includes communications fabric 202 , which provides communications between processor unit 204 , memory 206 , persistent storage 208 , communications unit 210 , input/output (I/O) unit 212 , and display 214 .
[0031] Processor unit 204 serves to execute instructions for software that may be loaded into memory 206 . Processor unit 204 may be a set of one or more processors or may be a multi-processor core, depending on the particular implementation. Further, processor unit 204 may be implemented using one or more heterogeneous processor systems in which a main processor is present with secondary processors on a single chip. As another illustrative example, processor unit 204 may be a symmetric multi-processor system containing multiple processors of the same type.
[0032] Memory 206 and persistent storage 208 are examples of storage devices. A storage device is any piece of hardware that is capable of storing information either on a temporary basis and/or a permanent basis. Memory 206 , in these examples, may be, for example, a random access memory or any other suitable volatile or non-volatile storage device. Persistent storage 208 may take various forms depending on the particular implementation.
[0033] For example, persistent storage 208 may contain one or more components or devices. For example, persistent storage 208 may be a hard drive, a flash memory, or some combination of the above. The media used by persistent storage 208 also may be removable. For example, a removable hard drive may be used for persistent storage 208 .
[0034] Communications unit 210 , in these examples, provides for communications with other data processing systems or devices. In these examples, communications unit 210 is a network interface card. Communications unit 210 may provide communications through the use of either or both physical and wireless communications links.
[0035] Input/output unit 212 allows for input and output of data with other devices that may be connected to data processing system 200 . For example, input/output unit 212 may provide a connection for user input through a keyboard and mouse. Display 214 provides a mechanism to display information to a user.
[0036] Instructions for the operating system and applications or programs are located on persistent storage 208 . These instructions may be loaded into memory 206 for execution by processor unit 204 . The processes of the different embodiments may be performed by processor unit 204 using computer implemented instructions, which may be located in a memory, such as memory 206 .
[0037] These instructions are referred to as program code, computer usable program code, or computer readable program code that may be read and executed by a processor in processor unit 204 . The program code in the different embodiments may be embodied on different physical or tangible computer readable media, such as memory 206 or persistent storage 208 .
[0038] Program code 216 is a functional form and located on computer readable media 218 that is selectively removable and may be loaded onto or transferred to data processing system 200 for execution by processor unit 204 . Program code 216 and computer readable media 218 form computer program product 220 in these examples.
[0039] In one example, computer readable media 218 may be in a tangible form, such as, for example, an optical or magnetic disc that is inserted or placed into a drive or other device that is part of persistent storage 208 for transfer onto a storage device, such as a hard drive that is part of persistent storage 208 .
[0040] In a tangible form, computer readable media 218 also may take the form of a persistent storage, such as a hard drive, a thumb drive, or a flash memory that is connected to data processing system 200 . The tangible form of computer readable media 218 is also referred to as computer recordable storage media. In some instances, computer readable media 218 may not be removable.
[0041] Alternatively, program code 216 may be transferred to data processing system 200 from computer readable media 218 through a communications link to communications unit 210 and/or through a connection to input/output unit 212 . The communications link and/or the connection may be physical or wireless in the illustrative examples. The computer readable media also may take the form of non-tangible media, such as communications links or wireless transmissions containing the program code.
[0042] In some illustrative embodiments, program code 216 may be downloaded over a network to persistent storage 208 from another device or data processing system for use within data processing system 200 . For instance, program code stored in a computer readable storage medium in a server data processing system may be downloaded over a network from the server to data processing system 200 . The data processing system providing program code 216 may be a server computer, a client computer, or some other device capable of storing and transmitting program code 216 .
[0043] The different components illustrated for data processing system 200 are not meant to provide architectural limitations to the manner in which different embodiments may be implemented. The different illustrative embodiments may be implemented in a data processing system including components in addition to or in place of those illustrated for data processing system 200 . Other components shown in FIG. 2 can be varied from the illustrative examples shown.
[0044] As one example, a storage device in data processing system 200 is any hardware apparatus that may store data. Memory 206 , persistent storage 208 and computer readable media 218 are examples of storage devices in a tangible form.
[0045] In another example, a bus system may be used to implement communications fabric 202 and may be comprised of one or more buses, such as a system bus or an input/output bus. Of course, the bus system may be implemented using any suitable type of architecture that provides for a transfer of data between different components or devices attached to the bus system.
[0046] Additionally, a communications unit may include one or more devices used to transmit and receive data, such as a modem or a network adapter. Further, a memory may be, for example, memory 206 or a cache such as found in an interface and memory controller hub that may be present in communications fabric 202 .
[0047] The different advantageous embodiments recognize and take into account that currently used systems for limiting engine power may be insufficient. The different advantageous embodiments recognize that currently used systems ramp and/or allow an increase in the maximum engine power based on airspeed.
[0048] The different advantageous embodiments recognize that using only airspeed may have a susceptibility to the thrust appearing to stop less than the target thrust until sufficient airspeed is attained. Further, the different advantageous embodiments also recognize that the use of airspeed to control the amount of thrust may allow the thrust to be reduced if a gust of wind causes a reduction in airspeed.
[0049] For example, if a pilot commands or selects full power while applying pressure on the brakes, the engines may increase thrust and hold at around 96 percent power. Once the brakes are released and the aircraft begins to roll forward, the engine power may remain at around 96 percent until the airspeed exceeds a certain threshold. This threshold may be around 30 knots. At this point, the thrust may be ramped or increased to 100 percent power using a linear ramp with increasing airspeed.
[0050] The different advantageous embodiments, recognize and take into account that situations may exist in which using airspeed to ramp thrust may not result in a linear or smooth increase in power as expected by a pilot. For example, if the aircraft begins rolling forward as the throttles are advanced such that 30 knots of airspeed is achieved before the engines have reached 96 percent power, little, if any, pause in engine power may exist.
[0051] Further, wind gusts may produce a noticeable rollback or reduction in thrust when these wind gusts reduce the airspeed of the aircraft. The different advantageous embodiments recognize and take into account that a concern may be present in which a pilot may perceive an unusual delay or rollback of the engines as an anomaly and abort a takeoff.
[0052] Thus, the different advantageous embodiments provide a method and apparatus for limiting thrust in a manner that presents a pilot with a continuously increasing thrust. This limit also ensures that a fan blade threshold is met such that undesirable vibrations that may require more frequent maintenance or sooner maintenance may be avoided. The different advantageous embodiments use a groundspeed limit and an airspeed limit to limit the amount of thrust generated by an engine. This type of system may provide a limit for the amount of thrust, but may allow for continuous thrust increase during a rolling takeoff procedure.
[0053] When a command is received for a selected level of thrust for an aircraft, the level of thrust provided by the engine may be based both on the groundspeed and the airspeed of the aircraft. A determination may be made as to whether a groundspeed limit for the thrust is to be used based on the groundspeed and the airspeed. In response to the groundspeed limit being present, the level of thrust is provided using the lower value generated between the groundspeed limit and airspeed limit.
[0054] In response to the groundspeed limit not being used, the level of thrust may be provided using the airspeed limit. At some speed of travel on the ground, the airspeed limit also may no longer be used. Further, one or more of the airspeed limit and the groundspeed limit also may be used again after this use if the requested level of thrust is less than the groundspeed limit and the groundspeed falls below some threshold.
[0055] In the different advantageous embodiments, the commanded level and the actual level of thrust is displayed to the operator. The operator may observe a lag as the thrust increases, but is less likely to mistakenly identify the lag and/or limits as an anomaly in the engine.
[0056] Turning now to FIG. 3 , a diagram illustrating a thrust control system is depicted in accordance with an advantageous embodiment. Thrust control system 300 may be implemented using a data processing system such as, for example, data processing system 200 in FIG. 2 .
[0057] In this example, thrust control system 300 includes throttle controller 302 , thrust control unit 304 , groundspeed sensor 306 , airspeed sensor 308 , and engine 310 . Throttle controller 302 may be a controller located in a cockpit of an aircraft such as, for example, aircraft 100 . Thrust control unit 304 may be a computer physically located at engine 310 . Thrust control unit 304 receives input from groundspeed sensor 306 and airspeed sensor 308 .
[0058] These various components illustrated for thrust control system 300 may be implemented using currently available components. For example, airspeed sensor 308 may detect airspeed based on impact pressure. For example, airspeed sensor 308 may detect a pressure difference caused by forward motion, which may be total pressure minus static pressure.
[0059] Groundspeed sensor 306 may be, for example, an inertially based sensor, a global positioning system sensor, or some other suitable type of device. The different advantageous embodiments recognize that an airspeed detected by airspeed sensor 308 may be invalid at speeds less than around 30 knots.
[0060] With reference now to FIG. 4 , a diagram illustrating a thrust control unit is depicted in accordance with an advantageous embodiment. In this example, thrust control unit 400 is a more detailed example of thrust control unit 304 in FIG. 3 .
[0061] In this example, thrust control unit 400 includes thrust control process 402 , groundspeed limit unit 404 , airspeed limit unit 406 , and policy 408 . Thrust control process 402 may receive commanded thrust 410 as an input. Commanded thrust 410 may be received from a controller such as, for example, throttle controller 302 in FIG. 3 .
[0062] Commanded thrust 410 is a command indicating the level of thrust desired by a pilot. Thrust control process 402 also may receive airspeed 412 and groundspeed 414 as inputs when generating engine command 416 . Engine command 416 is the command actually sent to the engine by thrust control unit 400 and may vary from commanded thrust 410 , depending on the application of policy 408 .
[0063] Policy 408 is a set of rules. A set as used herein refers to one or more items. For example, a set of rules is one or more rules. Policy 408 may be used by thrust control process 402 to determine whether groundspeed limit unit 404 and/or airspeed limit unit 406 should be used to provide limits when generating engine command 416 . If neither groundspeed limit 404 nor airspeed limit 406 limit is applied, engine command 416 may be the same as commanded thrust 410 . Groundspeed limit unit 404 and airspeed limit unit 406 are functions that may be used to limit the amount of thrust in engine command 416 .
[0064] The limits generated by these units may be used to limit the amount of thrust requested in commanded thrust 410 . In other words, groundspeed limit unit 404 and/or airspeed limit unit 406 may generate limits for the level of thrust for engine command 416 . With the limits that may be generated by groundspeed limit unit 404 and/or airspeed limit unit 406 , engine command 416 may provide a level of thrust that is less than commanded thrust 410 depending on the speed of aircraft.
[0065] In these examples, groundspeed limit unit 404 applies when the groundspeed of the aircraft is less than some limit. Groundspeed limit unit 404 may be disabled when the groundspeed or the airspeed exceeds some threshold. The threshold for the groundspeed and airspeed are different in these examples. The groundspeed threshold for disabling groundspeed limit unit 404 may be higher than the airspeed threshold in these examples.
[0066] Groundspeed limit unit 404 is implemented as a ramp function using groundspeed 414 . In this manner, the thrust may increase continuously from a lower limit up to an upper limit. This upper limit in these examples is an airspeed thrust limit. This airspeed thrust limit may be set at a level to prevent undesirable vibrations in the fan blades that may occur due to changes in aerodynamics caused by crosswinds. In these illustrative examples, groundspeed limit unit 404 may be implemented in a number of different ways. For example, groundspeed limit unit 404 may be implemented as a table, a series of equations, or some other suitable function.
[0067] For example, groundspeed limit unit 404 may provide for a groundspeed using the following equation:
[0000] maximum thrust=((6/55)*groundspeed)+90.
[0000] Alternatively, a table may set the limit for the thrust based on the groundspeed.
[0068] Airspeed limit unit 406 is an upper limit to the thrust that may be commanded. This limit also may be disabled when the airspeed is above a selected level. In these examples, airspeed limit unit 406 may be implemented using logical hysteresis or any other suitable function or process. For example, the limit may switch off when airspeed increases from some airspeed to another airspeed.
[0069] Further, the limit may be switched on or used when the airspeed decreases from a higher airspeed to a lesser airspeed. For example, the limit may be 96 percent of the maximum thrust when the airspeed is less than 50 knots. When the airspeed becomes greater than 50 knots, the limit is then the maximum thrust. The limit may be turned back on if the airspeed decreases from a level that is greater than 35 knots to less than 35 knots. When that occurs, the limit may be set to 96 percent of the maximum thrust rather than providing maximum thrust.
[0070] With reference now to FIG. 5 , a diagram illustrating limits supplied to engine thrust is depicted in accordance with an advantageous embodiment. In this example, graph 500 illustrates groundspeed on horizontal axis 502 and airspeed on horizontal axis 504 . The thrust is a percentage of maximum thrust. Thrust in percent is represented by vertical axis 505 . Line 506 illustrates a groundspeed limit, while line 508 illustrates an airspeed limit. Line 510 illustrates a resulting limit from these two limits. The resulting limit in line 510 may change depending on whether wind is present.
[0071] In this example, no wind is present. The groundspeed limit represented by line 506 is level until 10 knots groundspeed is reached. The amount of thrust that may be generated increases as a ramp until 65 knots is reached. At 65 knots, the thrust limit is level. The airspeed limit represented by line 508 is level until an airspeed of 50 knots is reached. At that point, the airspeed limit is removed and the maximum thrust may be generated. As can be seen by this example, the groundspeed limit is removed when the airspeed reaches 50 knots.
[0072] With reference now to FIG. 6 , a diagram illustrating limits for thrust is depicted in accordance with an advantageous embodiment. In this example, graph 600 , horizontal axis 602 represents groundspeed, while horizontal axis 604 represents airspeed. Vertical axis 606 represents thrust. Line 608 represents a groundspeed limit, while line 610 represents an airspeed limit. Line 612 represents a resulting limit from these two limits.
[0073] In this example, a 15 knot headwind is encountered by the aircraft. As can be seen, an airspeed of 50 knots is reached more quickly as compared to graph 500 with the presence of a headwind. When 50 knots is reached, the groundspeed limit is no longer effective. Further, the airspeed limit is also removed resulting in power being increased to a maximum thrust for the engine.
[0074] With reference now to FIG. 7 , a diagram illustrating limits for thrust is depicted in accordance with an advantageous embodiment. In graph 700 , horizontal axis 702 represents groundspeed, while horizontal axis 704 represents airspeed. Vertical axis 706 represents thrust. Line 708 represents a groundspeed limit, while line 710 represents an airspeed limit. Line 712 illustrates the resulting limit between the airspeed limit and the groundspeed limit.
[0075] In this example, a 15 knot tailwind is present. As a result, an airspeed of 50 knots is not reached until the groundspeed of 65 knots also is reached. As a result, the limit is not removed until the groundspeed has reached 65 knots in this example.
[0076] With reference to FIGS. 8-10 , an example of logic for a thrust control process is depicted in accordance with an advantageous embodiment. The logic illustrated in FIGS. 8-10 are simplified diagrams of logic that may be used.
[0077] These simplified diagrams are presented for purposes of illustrating logic on a high level for use in a thrust control process, such as thrust control process 402 . The actual logic used to implement these processes may include other logic components in addition to or in place of the ones depicted in these figures.
[0078] With reference now to FIG. 8 , a diagram illustrating logic for controlling thrust is depicted in accordance with an advantageous embodiment. Logic 800 in FIG. 8 is an example of logic that may be implemented in thrust control process 402 in FIG. 4 .
[0079] In this example, logic 800 receives command 802 as an input. Logic 800 also receives groundspeed 804 , groundspeed limit enable 806 , airspeed 808 , and airspeed limit enable 810 as inputs.
[0080] Groundspeed 804 is sent to groundspeed limit unit 812 . The output of groundspeed limit unit 812 is a groundspeed limit for a thrust level that is based on groundspeed 804 . The output of groundspeed limit unit 812 may be a thrust level that is less than that in command 802 . When groundspeed limit enable is a logic “1”, groundspeed limit unit 812 is used to control thrust. This thrust level is input into switch 814 . Switch 814 may be enabled by groundspeed limit enable 806 . Additionally, command 802 also is input into switch 814 . The output of switch 814 is sent into minimum unit 816 .
[0081] Airspeed 808 is entered as an input into airspeed limit unit 818 . Airspeed limit unit 818 generates an airspeed limit for a thrust level based on airspeed 808 . The output of airspeed limit unit 818 may be a thrust level that is less than the amount of thrust requested by command 802 . This thrust level is sent to switch 820 . Switch 820 also receives command 802 as an input. Switch 820 may be enabled by airspeed limit enable 810 . When airspeed limit enable is a logic “1”, airspeed limit unit 818 is used to control thrust. The output of switch 820 is sent to minimum unit 816 .
[0082] Minimum unit 816 selects the lower value of the outputs of switch 814 and switch 820 . In these examples, groundspeed limit unit 812 is typically a lower limit than airspeed limit unit 818 . Then this output forms command 822 which is used to control the engine.
[0083] In these examples, command 802 also forms thrust display 824 which is an output for the display that is seen by the pilot. In the different advantageous embodiments, although command 822 may be lower than command 802 , the pilot sees the same level of commanded thrust in command display 824 as command 802 . The pilot may perceive a lag in the thrust increasing as the airspeed increases. This increase in thrust, however, may be maintained as a constant increase to avoid aborting a takeoff when an engine anomaly is not actually present.
[0084] With reference now to FIG. 9 , a diagram illustrating logic to enable a groundspeed limit is depicted in accordance with an advantageous embodiment. In this example, logic 900 receives a number of different inputs. These inputs include aircraft on ground 902 , groundspeed valid 904 , groundspeed 906 , constant 908 , airspeed valid 910 , airspeed 912 , and constant 914 .
[0085] In this example, aircraft on ground 902 indicates whether the aircraft is on the ground. A logic “1” indicates that the aircraft is on the ground in these examples. Groundspeed valid 904 is a logic “1” if the groundspeed is valid. Groundspeed 906 is the groundspeed detected by a groundspeed sensor. A groundspeed may not be valid if, for example, a groundspeed sensor is disabled or faulty. Constant 908 in this example is a speed limit at which the groundspeed limit should be enabled. In this example, constant 908 is 70 knots.
[0086] Groundspeed 906 and constant 908 are compared by comparator 911 . Comparator 911 determines whether groundspeed 906 is less than constant 908 . If groundspeed 906 is less than constant 908 , a true value is generated by comparator 911 and sent into AND gate 915 . If groundspeed 906 is not less than constant 908 , a false value is generated by comparator 911 and sent into AND gate 915 . AND gate 915 also receives groundspeed valid 904 and aircraft on ground 902 as inputs. The output of AND gate 915 is true if all of the inputs are true.
[0087] Airspeed 912 and constant 914 are sent into comparator 916 . In these examples, if airspeed 912 is greater than constant 914 , the output of comparator 916 is the logic “1.” This output is sent into AND gate 918 . AND gate 918 also receives airspeed valid 910 as an input. If the airspeed is valid and airspeed 912 is greater than constant 914 , a logic “1” is output by AND gate 918 . This output is sent into OR gate 920 . Additionally, the output of AND gate 915 is sent through inverter 922 into OR gate 920 . The output of OR gate 920 is sent into latch 922 .
[0088] Latch 922 also receives the output of AND gate 915 as an input. When the output of AND gate 915 is true, the output of latch 922 is set true, and remains true until the output of OR gate 920 is true. As long as the output of OR gate 920 is true, the output of latch 922 is false. The output of latch 922 forms groundspeed limit enable 924 , which is used in logic 800 . More specifically, groundspeed limit enable 924 is an example of groundspeed limit enable 806 in FIG. 8 .
[0089] In essence, groundspeed logic 900 determines whether the groundspeed limit is to be used. In these examples, logic 900 enables the groundspeed limit when the groundspeed is valid, the groundspeed is less than 70 knots, and the aircraft is on the ground.
[0090] Once logic 900 enables the groundspeed limit, this limit may be disabled if the groundspeed becomes invalid, the groundspeed exceeds 70 knots, the aircraft is in the air, or the airspeed is valid and the airspeed is greater than 50 knots. If the groundspeed limit has been disabled with speed that is above a selected level, or if the groundspeed is invalid, the groundspeed limit may be re-enabled. In this example, the disabling speed may be an airspeed of 50 knots and/or a groundspeed of 70 knots.
[0091] The groundspeed may be re-enabled if the commanded or requested thrust is less than the groundspeed limit for the current groundspeed, the groundspeed is valid, and the groundspeed falls below 20 knots.
[0092] With reference now to FIG. 10 , a diagram illustrating logic to generate an airspeed limit enable signal is depicted in accordance with an advantageous embodiment. In this example, logic 1001 receives a number of different inputs. These inputs include, for example, aircraft on ground 1000 , airspeed 1002 , constant 1004 , airspeed valid 1006 , groundspeed valid 1008 , groundspeed 1010 , and constant 1012 .
[0093] In this example, aircraft on ground 1000 is sent into latch 1014 . Airspeed 1002 and constant 1004 are sent to comparator 1016 . In this example, constant 1004 is 50 knots. If airspeed 1002 is greater than constant 1004 , a logic “1” is sent into AND gate 1018 . AND gate 1018 also receives airspeed valid 1006 as an input. The output of AND gate 1018 is sent into OR gate 1020 . Airspeed valid 1006 is sent through inverter 1022 to the input of AND gate 1024 . Groundspeed valid 1008 also forms an input into AND gate 1024 .
[0094] Groundspeed 1010 and constant 1012 are sent to comparator 1026 . In these examples, comparator 1026 determines whether groundspeed 1010 is less than constant 1012 . The output of comparator 1026 is sent through inverter 1027 to AND gate 1024 . The output of AND gate 1024 is sent to OR gate 1020 .
[0095] Aircraft on ground 1000 is also an input into OR gate 1020 . Aircraft on ground 1000 is sent through inverter 1026 into OR gate 1020 . If groundspeed 1010 is less than constant 1012 , the output of comparator 1026 is a logic “1” in these examples. Constant 1012 has a value of 70 knots in this example.
[0096] The output of OR gate 1020 is sent as an input into latch 1014 . The output of latch 1014 is set true when the aircraft is on the ground. When any of the input conditions cause the output of OR gate 1020 to be true, the output of latch 1014 is held false. The output of latch 1014 forms airspeed limit enable 1028 . This value is an input into logic 800 in FIG. 8 . Airspeed limit enable 1028 is an example of groundspeed limit enable 806 in FIG. 8 .
[0097] In this example, logic 1001 disables the airspeed limit when the airspeed is greater than 50 knots. The airspeed limit may be re-enabled in these examples, if the airspeed is less than 35 knots or if the airspeed is invalid and the groundspeed is valid and less than 20 knots, and if the commanded level thrust is less than the airspeed limit.
[0098] The logic illustrated in FIGS. 8-10 are provided as an example of one manner in which groundspeed and airspeed may be used to control thrust during takeoff. This example is not meant to imply physical or architectural limitations to the manner in which other advantageous embodiments may be implemented.
[0099] With reference now to FIG. 11 , a high level flowchart of a process for controlling thrust generated by an aircraft is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 11 may be implemented in thrust control process 402 in FIG. 4 .
[0100] The process begins by receiving a command for a desired level of thrust for an aircraft on the ground (operation 1100 ). The process sends the command to a thrust display (operation 1102 ). The thrust display in operation 1102 may be, for example, thrust display 312 in FIG. 3 .
[0101] The process controls a level of thrust actually provided by an engine in the aircraft based on a groundspeed and an airspeed (operation 1104 ), with the process terminating thereafter. Operation 1104 uses a lower limit of thrust set by a ground speed limit and an airspeed limit to control the level of thrust of the engine for the aircraft.
[0102] The level of thrust provided is based on the desired level of thrust and the lower limit, wherein the level of thrust is a continuous linear increase in thrust limited by the groundspeed limit and the airspeed limit. In other words, the level of thrust does not exceed the lower of the two limits as long as the limits are enabled or being used in the manner described in these examples.
[0103] With reference now to FIG. 12 , a flowchart of a process for controlling thrust generated by an aircraft is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 12 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 . More specifically, FIG. 12 is a more detailed illustration of the process in FIG. 11 .
[0104] The process begins by receiving a command for a selected level of thrust for the aircraft (operation 1200 ). A determination is made as to whether a groundspeed limit has been enabled (operation 1202 ). If the groundspeed limit has been enabled, the thrust command is set using the groundspeed limit based on the current groundspeed (operation 1204 ), with the process terminating thereafter.
[0105] With reference again to step 1202 , if the groundspeed limit is not enabled, a determination is made as to whether an airspeed limit has been enabled (operation 1206 ). If the airspeed limit has been enabled, the thrust command is set using the airspeed limit based on the current airspeed (operation 1208 ), with the process terminating thereafter.
[0106] With reference again to operation 1206 , if the airspeed limit is not enabled, the process sets the thrust command as the received command (operation 1210 ), with the process terminating thereafter. In this case, the commanded thrust is the actual level of thrust that is sent as a thrust command to the engine. In operation 1210 , no limits are applied to the actual thrust since the groundspeed limit and the airspeed limit are not enabled.
[0107] With reference now to FIG. 13 , a flowchart of a process for enabling and disabling a groundspeed limit is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 13 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 .
[0108] The process begins by determining whether the aircraft is on the ground (operation 1300 ). If the aircraft is not on the ground, the process disables the groundspeed limit (operation 1302 ). Next, the disable flag is set as true (operation 1304 ), with the process terminating thereafter.
[0109] With reference again to operation 1300 , if the aircraft is on the ground, a determination is made as to whether the disable flag is set equal to true (operation 1306 ). This determination is made to identify whether the groundspeed limit has been previously disabled, but may need to be re-enabled, for example if the aircraft has left the ground but returned to the ground.
[0110] If the disable flag is set equal to true, a determination is made as to whether the groundspeed is valid (operation 1308 ). If the groundspeed is not valid, the groundspeed limit is disabled (operation 1310 ) and the process sets the disable flag equal to true (operation 1312 ), with the process terminating thereafter.
[0111] With reference again to operation 1308 , if the groundspeed is valid, a determination is made as to whether the groundspeed is less than 20 knots (operation 1314 ). The threshold value of 20 knots is set at a speed that indicates that the aircraft is no longer taking off. In this case, the aircraft either was taking off and aborted the take off or took off and subsequently landed.
[0112] If the groundspeed is not less than 20 knots, the process proceeds to operation 1310 as described above. Otherwise, a determination is made as to whether the thrust is less than the thrust command (operation 1316 ). In this example, the thrust command is the command or desired thrust requested by pilot.
[0113] If the thrust is not less than the thrust command, the process proceeds to operation 1310 as previously described. Otherwise, the process re-enables the groundspeed limit (operation 1318 ). The process then sets the disable flag to false (operation 1320 ), with the process terminating thereafter.
[0114] With reference again to operation 1306 , if the disable flag is not true, a determination is made as to whether the airspeed is valid (operation 1322 ). If the airspeed is valid, a determination is made as to whether the airspeed is greater than 50 knots (operation 1324 ). If the airspeed is greater than 50 knots, the groundspeed limit is disabled (operation 1326 ). The process then sets the disable flag equal to true (operation 1328 ), with the process terminating thereafter.
[0115] With reference again to operation 1324 , if the airspeed is not greater than 50 knots, the groundspeed limit is enabled (operation 1330 ). The process then sets the disable flag equal to false (operation 1332 ), with the process terminating thereafter.
[0116] With reference again to operation 1322 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1334 ). If the groundspeed is not valid, the process proceeds to operation 1326 as described above. If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 70 knots (operation 1336 ).
[0117] In this example, the 70 knot groundspeed level provides a 20 knot margin above the airspeed limit of 50 knots. This margin allows for continuous engine acceleration for a takeoff in a 15-knot tailwind, as illustrated in FIG. 7 , and provides an additional 5 knot margin to account for uncertainty in the groundspeed sensing system. Of course, other thresholds may be selected depending on the implementation. If the groundspeed is not less than 70 knots, the process proceeds to operation 1326 . Otherwise, the process proceeds to operation 1330 as described above.
[0118] With reference now to FIG. 14 , a flowchart of a process for enabling and disabling an airspeed limit is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 14 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 .
[0119] The process begins by determining whether the aircraft is on the ground (operation 1400 ). If the aircraft is not on the ground, the process disables the airspeed limit (operation 1402 ). The process then sets the disable flag equal to true (operation 1404 ), with the process terminating thereafter.
[0120] With reference again to operation 1400 , if the aircraft is on the ground, a determination is made as to whether the disable flag is set equal to true (operation 1406 ). If the disable flag is true, a determination is made as to whether the airspeed is valid (operation 1408 ). If the airspeed is valid, a determination is made as to whether the airspeed is less than 35 knots (operation 1410 ). If the airspeed is less than 35 knots, a determination is made as to whether the thrust is less than the thrust command (operation 1412 ). If the thrust is less than the thrust command, the process re-enables the airspeed limit (operation 1414 ) and sets the disable flag to false (operation 1416 ), with the process terminating thereafter.
[0121] In operation 1412 , if the thrust is not less than the thrust command, the process disables the airspeed limit (operation 1418 ) and sets the disable flag equal to true (operation 1420 ). With reference again to operation 1410 , if the airspeed is not less than 35 knots, the process also proceeds to operation 1418 .
[0122] In operation 1408 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1422 ). If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 20 knots. If the groundspeed is less than 20 knots, the process proceeds to operation 1412 as described above. Otherwise, the process proceeds to operation 1418 as previously described. In operation 1422 , the process proceeds to operation 1418 if the groundspeed is not valid.
[0123] With reference again to operation 1406 , if the disable flag is not true, a determination is made as to whether the airspeed is valid (operation 1426 ). If the airspeed is valid, a determination is made as to whether the airspeed is greater than 50 knots (operation 1428 ). If the airspeed is greater than 50 knots, the process disables the airspeed limit (operation 1430 ). The process then sets the disable flag equal to true (operation 1432 ), with the process terminating thereafter. As an example, the threshold of 50 knots may be the airspeed at which inlet separation due to crosswinds has been eliminated, and full thrust is allowed.
[0124] If the airspeed is not greater than 50, the process enables the airspeed limit (operation 1434 ). The process then sets the disable flag to false (operation 1436 ), with the process terminating thereafter.
[0125] With reference again to operation 1426 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1438 ). If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 70 knots (operation 1440 ). If the groundspeed is less than 70 knots, the process proceeds to operation 1434 as described above. The 70 knot groundspeed limit is selected to provide a margin above the 50 knot airspeed limit. Otherwise, the process proceeds to operation 1430 as previously described. The process also proceeds to operation 1430 in operation 1438 if the groundspeed is not valid.
[0126] The different thresholds illustrated in FIGS. 13 and 14 have been selected for purposes of depicting one implementation and are not meant to limit the manner in which other advantageous embodiments may be implemented. For example, in other advantageous embodiments, other groundspeed thresholds may be used other than those illustrated.
[0127] The flowcharts and block diagrams in the different depicted embodiments illustrate the architecture, functionality, and operation of some possible implementations of apparatus, methods and computer program products. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of computer usable or readable program code, which comprises one or more executable instructions for implementing the specified function or functions.
[0128] In some alternative implementations, the function or functions noted in the block may occur out of the order noted in the figures. For example, in some cases, two blocks shown in succession may be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
[0129] Thus, the different advantageous embodiments provide a method, apparatus, and program code for managing thrust levels in an aircraft. The different advantageous embodiments receive a command for a selected amount of thrust. The actual amount of thrust generated by the engine may be controlled based on the groundspeed and airspeed of the aircraft. In these different advantageous embodiments, an airspeed limit and a groundspeed limit may be applied to the received command to identify the actual command to be sent to the engine to generate thrust.
[0130] Using the different advantageous embodiments, an operator of the aircraft perceives a constant increase in thrust without reaching speed limits that may produce additional wear and tear on the engine. In particular, undesired vibrations on fan blades in the engine may be avoided to reduce the frequency of maintenance for these and other components.
[0131] The operator may only perceive a lag in engine thrust. As a result, the operator may not mistakenly perceive an anomaly in the engine requiring aborting the takeoff.
[0132] The different advantageous embodiments can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment containing both hardware and software elements. Some embodiments are implemented in software, which includes but is not limited to forms, such as, for example, firmware, resident software, and microcode.
[0133] Furthermore, the different embodiments can take the form of a computer program product accessible from a computer usable or computer readable medium providing program code for use by or in connection with a computer or any device or system that executes instructions. For the purposes of this disclosure, a computer usable or computer readable medium can generally be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
[0134] The computer usable or computer readable medium can be, for example, without limitation an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium. Non-limiting examples of a computer readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk, and an optical disk. Optical disks may include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD.
[0135] Further, a computer usable or computer readable medium may contain or store a computer readable or usable program code such that when the computer readable or usable program code is executed on a computer, the execution of this computer readable or usable program code causes the computer to transmit another computer readable or usable program code over a communications link. This communications link may use a medium that is, for example without limitation, physical or wireless.
[0136] A data processing system suitable for storing and/or executing computer readable or computer usable program code will include one or more processors coupled directly or indirectly to memory elements through a communications fabric, such as a system bus. The memory elements may include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some computer readable or computer usable program code to reduce the number of times code may be retrieved from bulk storage during execution of the code.
[0137] Input/output or I/O devices can be coupled to the system either directly or through intervening I/O controllers. These devices may include, for example, without limitation, keyboards, touch screen displays, and pointing devices. Different communications adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Non-limiting examples are modems and network adapters are just a few of the currently available types of communications adapters.
[0138] The description of the different advantageous embodiments has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous embodiments may provide different advantages as compared to other advantageous embodiments.
[0139] The embodiment or embodiments selected are chosen and described in order to best explain the principles of the embodiments, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated. | A method is presented for controlling thrust generated by aircraft engines. Engine thrust is controlled based on aircraft groundspeed and airspeed during the initial part of takeoff. Limiting thrust at low groundspeed during the initial phase of takeoff has significant benefits that reduce engine stress during this brief but critical phase leading to flight. Logical elements combine both groundspeed and airspeed in such a way that the operator perceives a smooth progressive thrust increase consistent with normal engine operation. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for lamination by sandwiching an object between upper and lower heat-reactive laminating films and applying heat and pressure thereto.
2. Related Background Art
Lamination is used for various objects for improving the appearance or preservability thereof. FIG. 10 shows a conventional laminating apparatus used for such lamination.
FIG. 10 is a longitudinal cross-sectional view of a conventional laminating apparatus, wherein shown are an upper heat-reactive laminating film 100 and a lower heat-reactive laminating film 100'. These films are respectively rolled as an upper sheet roll 101 and a lower sheet roll 101'. Said laminating films 100, 100' respectively wrap around a heating roller 102 and a pressure roller 102' and are pulled at the front ends by pull rollers 103, 103' for giving a predetermined tension to said films. At the centers of said heating roller 102 and pressure roller 102' there are respectively provided heaters 104, 104' for heating said rollers.
At the downstream side (left side in FIG. 10) of said pull rollers 103, 103', there is provided a cutter 105 for cutting the front and rear ends of the object after lamination.
A feed table 106 is provided for supporting an object 107 to be laminated, which is inserted, along the feed table 106, into the nip of the heating roller 102 and the pressure roller 102', where the upper laminating film 100 and the lower laminating film 100' mutually meet.
On said laminating apparatus there is provided an operation unit, including switches 108, 109 for manually setting the transporting speed of the heating roller 102, pressure roller 102' and pull rollers 103, 103', and the peripheral temperature of the heating roller 102 and pressure roller 102'.
However such conventional laminating apparatus has been associated with a drawback that lamination of satisfactory appearance cannot be obtained with a transfer sheet discharged from an image forming apparatus, because the transfer sheet immediately after discharge contains moisture (e.g. from the ink) and generates bubbles due to said moisture sealed between the laminating films.
On the other hand, if the transfer sheet is sufficiently dried, the laminating operation cannot be efficient because the process on the laminating apparatus cannot be conducted immediately.
SUMMARY OF THE INVENTION
In consideration of the foregoing, the object of the present invention is to provide a laminating apparatus capable of automatically laminating even a moist object to provide satisfactory appearance and within a short period time.
According to the present invention, the object to be laminated is sandwiched between upper and lower laminating films, and is sufficiently dried by heating prior to the laminating operation of said object and said laminating films, so that the lamination can be immediately conducted regardless of the moisture content of the object, even in case of a moist transfer sheet discharged from an image forming apparatus or the like.
In the foregoing embodiments, the density detecting sensor 26 for detecting the image density is employed as means for detecting the moisture level of the transfer sheet, but such embodiments are not limiting. For example, since the moisture content of the transfer sheet is dependent on the humidity of ambient air, the apparatus may be provided with a humidity sensor 150 (FIG. 5) for detecting the humidity of ambient air, and the control circuit 70 may be so constructed as to control the temperature of the sheet heater 25 according to a detection signal from said humidity sensor 150.
The moisture content of the transfer sheet can also be measured by the measurement of electric resistance thereof. It is therefore possible to provide two electrodes so as to contact the transfer sheet in the sheet cassette 9 or in the transport path, to enter the output of a resistance sensor 151 for detecting the resistance between said two electrodes into the control circuit 70, and to control the temperature of the sheet heater 25 by said control circuit 70 according to the output signal of said resistance sensor 151. With such structure, the apparatus of the present invention exhibits excellent performance even with a sheet on which the image is formed by image forming means other than the ink jet recording head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view of a laminating apparatus embodying the present invention, mounted on an image forming apparatus;
FIG. 2 is a lateral view of a sheet thickness detecting mechanism provided at registration rollers;
FIGS. 3A and 3B are partial cross-sectional views of a sheet roll;
FIG. 4 is a developed view of a driving system of the laminating apparatus;
FIG. 5 is a block diagram of a control circuit, for explaining the function of the laminating apparatus;
FIG. 6 is a longitudinal cross-sectional view of another embodiment of the present invention;
FIG. 7 is a perspective view showing the structure of a bubble jet recording head;
FIGS. 8A to 8G are views showing the working principle of the bubble jet recording head;
FIG. 9 is a longitudinal cross-sectional view of still another embodiment; and
FIG. 10 is a longitudinal cross-sectional view of a conventional laminating apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following there will be explained an embodiment of the present invention, with reference to the attached drawings.
FIG. 1 is a longitudinal cross-sectional view of a laminating apparatus of the present invention, mounted on an image forming apparatus.
In a reader A, an original document placed on a platen glass 1 is illuminated by the light from an illuminating lamp 2, and the reflected light is guided by mirrors 3, 4 and focused by a lens 5 onto a CCD 6 for reading the original image. The image information of the image read by said reader A is transmitted to a printer B, and is recorded by a scanner 7 on a photosensitive drum 8 as an electrostatic latent image, which is developed by a developing unit 8a into a toner image.
On the other hand, transfer sheets 10 contained in a sheet cassette 9 in the printer B are fed one by one by a sheet feed roller 11, and the toner image on the photosensitive drum 8 is transferred, in a transfer unit 12, onto the transfer sheet 10, which is subsequently discharged from the printer B by a conveyor belt 13 and discharge rollers 14.
A laminating apparatus C of the present invention is detachably mounted, by a latch mechanism 15, on the main body of the image forming apparatus.
In said laminating apparatus, a flapper 16, driven by a solenoid 70 (FIG. 5), selects whether or not to effect lamination according to the state of a selector switch 17 (FIG. 5) provided in an operation unit on the outer casing of said laminating apparatus C. More specifically, in response to an instruction for non-lamination entered from the operation unit 7, the flapper 16 assumes a broken-line position in FIG. 1 to deflect the transfer sheet 10 to a non-lamination path 18, whereby said sheet 10 is discharged by discharge rollers 19 onto a sheet tray 20. On the other hand, in response to an instruction for lamination entered from the operation unit 17, the flapper 16 assumes a solid-line position in FIG. 1 to guide the sheet 10 into a lamination path 21 leading to a lamination unit.
As said discharged sheet tray 20 is provided on the upper face of the laminating apparatus C, constituting a part of the outer casing of said apparatus with open space above, the transfer sheets 10 stacked on said tray 20 can be easily removed. Also the space of the apparatus is reduced as said tray 20 is integrally constructed with the laminating apparatus C.
In FIG. 1, registration rollers 22, 22' are provided for adjusting the timing of the leading end of the transfer sheet 10 prior to the transfer to the laminating unit, and correcting skewed feed of the transfer sheet 10 released from the image forming apparatus, by forming a loop in the lamination path 21. Immediately in front of said registration rollers 22, 22', there is provided a pre-registration sensor 23, composed of a reflective photosensor, for detecting the edge of the transfer sheet 10.
A transfer path 24 for transferring the sheet 10 from the registration rollers 22, 22' to the laminating unit is composed of upper and lower guide plates 24a, 24b. Behind the upper guide plate 24a there is provided a sheet heater 25 for heating said upper guide plate 24a when said heater is on, whereby the sheet 10 is dried prior to the lamination. Said sheet heater 25 can be arbitrarily turned on or off by a selector switch of the operation unit 17, according to whether or not to heat the transfer sheet 10.
Between said registration rollers 22, 22' and the sheet heater 25 there is provided a density detecting sensor 26, composed of a photosensor, for detecting the density of the image on the sheet 10. The on/off control of said sheet heater 25 may be conducted according to the information on the image density.
Rolls 27, 27' of laminating films 28, 28' are respectively provided above and below. Laminating heaters 29, 29', for respectively heating said laminating films 28, 28', have a curved shape in order to heat said films over a wide area, and may be provided with sensors thereon for varying the heating temperature.
Pressure rollers 30, 30' are provided for pressing therebetween the laminating films 28, 28' heated by said heaters 29, 29' thereby laminating the transfer sheet 10. Separating fingers 31, 31' are constantly maintained in friction contact with the periphery of the pressure rollers 30, 30' for peeling the laminating films 28, 28' from the pressure rollers 30, 30' when said films stick to said rollers. At least one of said pressure rollers 30, 30' may be provided with a heater therein for simultaneously effecting heating and pressing.
A cutter unit 33, composed of a cutter blade 34, a die 35 and a cutter motor (not shown), is provided for cutting the front and rear ends of the laminated transfer sheet.
A lamination sensor 32, consisting of a reflective photosensor, is provided for detecting the front and rear ends of the laminated transfer sheet 10. Pull rollers 36, 36' have a peripheral speed larger than that of the pressure rollers 30, 30' so that the laminated transfer sheet 10 is subjected to a predetermined tension between said pull rollers 36, 36' and the pressure rollers 30, 30'.
Said sheet rolls 27, 27' are respectively given a load in the film drawing direction, so that the laminating films 28, 28' pulled by the pull rollers 36, 36' are given a tension between said pull rollers 36, 36' and the sheet rolls 27, 27' by means of the pressure rollers, 30, 30' and the heaters 29, 29'.
A waste case 39 is provided for receiving waste chips (laminated film area not containing the transfer sheet 10) of the laminating films 28, 28' cut by the cutter unit 33. Said case 39 can be pulled out forward from the apparatus, so that the waste chips in said case can be discharged when said case becomes full. Discharge rollers 37, 37' are provided for discharging the laminated transfer sheet 10 from the laminating apparatus C onto a laminate tray 38.
In the following the details of the units of the laminating apparatus C will be explained with reference to FIGS. 2 to 4.
At first there will be explained the details of the aforementioned registration rollers 22, 22' with reference to FIG. 2, which is a lateral view of a sheet thickness detecting mechanism provided at said registration rollers. The shaft 22a of the registration roller 22 engages with an end of a sheet thickness detecting lever 40, which therefore rotates about a rotating shaft 41 when the transfer sheet 10 enters the nip between the registration rollers 22, 22'. Said lever is provided with a lever flag 41", and the lengths of arms of said lever 40 are so selected as to satisfy a relation l 1 >l 2 , so that the amount of movement of the registration roller 22 is converted into an amplified amount of movement of said lever flag 41". Opposed to said lever flag 41" there is provided a sheet thickness sensor 43, composed of a photosensor, which linearly detects the amount of movement of the lever flag 41", thereby detecting the thickness of the transfer sheet 10 passing through the nip of the registration rollers 22, 22'.
In the following there will be explained the details of the sheet rollers 27, 27" with reference to FIGS. 3A, 3B which are partial cross-sectional views thereof. The sheet roll 27 is wound on a core 44 which is rendered rotatable on a roll shaft 47. Said roll shaft 47 is supported by a tension adjusting nut 49 on a lateral plate 48 of the laminating apparatus C. A tension regulating spring 50 is provided between said nut 49 and the core 44, so that the load against film drawing can be regulated by said tension adjusting nut 49.
FIG. 3A shows the sheet roll 27 of the laminating film 28 of a first thickness, wound on a first core 44, while FIG. 3B shows the sheet roll 27" of the laminating film 28" of a second thickness, wound on a second core 44'. The first core 44 has a straight end face, while the second core 44" has a flange 45.
A microswitch 46, provided on the side plate 48 for discriminating the core, is turned off when the first core 44 is mounted but is pressed, thereby being turned on, by said flange 45 when the second core 44" is mounted. The difference in thickness of the laminating film 28 or 28" can be identified by the discrimination of the core 44 or 44".
The present embodiment utilizes the discrimination of laminating films of two different thicknesses, but it is also possible to discriminate three or more different thicknesses of the laminating film by correspondingly varying the diameter of the flange 45 and increasing the number of microswitches 46.
In the following there will be explained the details of the driving system with reference to FIG. 4.
Referring to FIG. 4 which is a developed view of the driving system of the laminating apparatus C, a main motor 51 has a motor gear 52 on the output shaft whereby the rotation of said main motor 51 is transmitted through a motor gear 52, idler gears 60, 54 and a pull roller clutch 59 to a pull roller gear 53 and a discharge roller gear 55, thereby rotating the pull roller 36 and the discharge rollers 37. The rotation of said pull rollers 36 and discharge rollers 37 is controlled by said pull roller clutch 59.
Also the rotation of the main motor 51 is transmitted, through the motor gear 52, idler gears 56, 57, 58, 59', 60' and 61 to a discharge roller gear 62, thereby rotating the discharge rollers 19.
On the shaft of the idler gear 57 there is provided a pressure roller clutch 63, which is connected to a pressure roller gear 65, thereby controlling the rotation of the pressure rollers 30. Similarly the idler gear 59' is provided, on the shaft thereof, with a registration roller clutch 64 which is connected to a registration roller gear 66 for controlling the rotation of the registration rollers 22.
On the shaft of the main motor 51 and opposite to the motor gear 52, there is provided a clock disk 67 having plural slits at a constant pitch, and a clock sensor, consisting of a transmissive photosensor, is provided in the vicinity of said clock disk 67 for detecting the slits.
In the following there will be explained the operation, in the laminating apparatus C of the present invention, of laminating the transfer sheet 10 discharged from the image forming apparatus.
At first a lamination switch, provided in the operation unit 17 on the laminating apparatus C, is depressed to energize a solenoid (not shown), whereby the flapper 16 assumes the solid-line state in FIG. 1 to guide the transfer sheet 10 from the image forming apparatus into the lamination path 21. At the same time the main motor 51 is activated to rotate the discharge rollers 19. The registration rollers 22, pressure rollers 30, pull rollers 36 and discharge rollers 37 remain stopped, as the clutches 64, 65, 59 are deactivated.
When the front end of the transfer sheet 10 is detected by the pre-registration sensor 23, the clock sensor 68 starts to count the clock pulses. When the clock sensor 68 counts a number of clock pulses corresponding to a time required by the transfer sheet 10 to impinge, at the front end thereof, on the nip of the registration rollers 22, 22' and to form a predetermined amount of loop, the registration roller clutch 64 is energized whereby the transfer sheet 10 is introduced into the transfer path 24 by the registration rollers 22, 22'. The loop of the transfer sheet 10 formed in the lamination path 21 is maintained until the rear end of the transfer sheet 10 passes through discharge rollers 14 of the printer B.
When the clock sensor 68 detects that the front end of the transfer sheet 10 reaches a position l+α in front of the nip of the pressure rollers 30, 30' in the transfer path 24, wherein l is the distance from said nip to the nearest position of the heaters 29, 29', the pressure roller clutch 63 is turned on whereby the pressure rollers 30, 30' start to rotate. The arrival of the front end of the transfer sheet 10 at a position of l+α in front of the nip of the pressure rollers 30, 30' can be, detected, because the distance from the nip of said pressure rollers 30, 30' to that of the registration rollers 22, 22' is predetermined, by measuring the difference between said distance and l+α by the counting with the clock sensor 68 from the start of rotation of the registration rollers 22, 22'. Thus, the front end of the transfer sheet 10 becomes positioned by α behind the front end of the heated portion of the heaters 29, 29', so that the front end of the transfer sheet 10 can be securely laminated.
Thus the transfer sheet 10, sandwiched between the heated upper and lower laminating films 28, 28', is introduced together with said laminating film into the nip of the pressure rollers 30, 30', and is subjected to lamination by the pressure applied by said rollers. When the front end of the laminated transfer sheet 10 is detected by the lamination sensor 32, the registration roller clutch 64 and the pressure roller clutch 63 are simultaneously turned off, whereby the movement of the transfer sheet 10 is terminated. At the same time the cutter motor (not shown) in the cutter unit 33 is turned on to move the cutter blade 34 downwards, thereby cutting the front end portion of the laminated transfer sheet 10. When the cutter blade 34 is completely retracted upwards after the cutting, the registration roller clutch 64, pressure roller clutch 63 and pull roller clutch 59 are turned on to activate the registration rollers 22, 22', pressure rollers 30, 30' and pull rollers 36, 36'.
Upon detection of the rear end of the transfer sheet 10 by the pre-registration sensor 23, the registration roller clutch 64 is turned off to terminate the rotation of the registration rollers 22, 22' when the rear end of the transfer sheet 10 passes through the nip thereof. The clock sensor 68 is also used for measuring the amount of movement, from the detection of the rear end of the transfer sheet 10 by the pre-registration sensor 23 to the passing of the rear end of said sheet 10 through the nip of the registration rollers 22, 22'.
Upon detection of the rear end of the laminated transfer sheet 10 by the lamination sensor 32, the clock sensor 68 measures the sheet movement corresponding to the distance from said lamination sensor 32 to the cutter unit 33, and the pressure roller clutch 63 and the pull roller clutch 59 are turned off to terminate the movement of the laminated transfer sheet 10. At the same time, the cutter motor 71 is turned on to cut, with the cutter blade 34, the rear end portion of the laminated transfer sheet 10. After said cutting, the pull roller clutch 59 is turned on to activate the pull rollers 36 and the discharge rollers 37, whereby the laminated transfer sheet 10 is discharged and stacked on the laminate tray 38.
The transfer sheets 10 discharged in succession from the image forming apparatus can be laminated by the repetition of the above-explained procedure.
FIG. 5 is a block diagram of a control circuit of the present embodiment. Said control circuit is principally composed of a known one-chip microcomputer (MCOM) 70 equipped with a ROM, a RAM etc., and input ports P0-P7 of said microcomputer 70 are respectively connected to the aforementioned lamination/non-lamination selector switch 17; the clock sensor 68 for counting the amounts of movement of the rollers 19, 22, 22', 30, 30', 36, 36', 37 and 37', the pre-registration sensor 23 positioned immediately in front of the registration rollers 22, 22' for detecting the front and rear ends of the transfer sheet 10; the laminate sensor 32 positioned between the pressure rollers 30, 30' and the cutter unit 33 for detecting the front and rear ends of the laminated transfer sheet 10; the image density sensor 26 for detecting the image density of the transfer sheet 10 discharged from the image forming apparatus; the core discriminating switch 46 for discriminating the type of the core of the sheet roll 27 or 27' for identifying the thickness of the laminating film 28 or 28'; the sheet thickness sensor 43 for detecting the amount of displacement of the registration roller 22 thereby, identifying the thickness of the transfer sheet 10 passing through the registration rollers 22, 22'; and the switch 17 for the transfer sheet heater 25.
On the other hand, output ports F0-F7 respectively send signals, through drivers D0-D7, for on/off control of the solenoid 70 of the flapper 16 for selecting the lamination path or the non-lamination path; on/off control of the main motor 51 and the speed control thereof based on a predetermined speed according to the image density detected by the sensor 26, laminating film thickness detected by the core discriminating switch 46 and the thickness of transfer sheet detected by the sensor 43; on/off control of the registration roller clutch 64 for controlling the rotation of the registration rollers 22, 22'; on/off control of the pressure roller clutch 63 for controlling the rotation of the pressure rollers 30, 30'; on/off control of the pull roller clutch 59 for controlling the rotation of the pull rollers 36, 36' and the discharge rollers 37, 37'; on/off control of the sheet heater 25 for heating the transfer sheet prior to the lamination and temperature control therefor based on a predetermined temperature according to the change in the image density of the transfer sheet detected by the sensor 26; on/off control of the lamination heaters 29, 29' for heating the laminating films 28, 28' and control of surface temperature of said lamination heaters 29, 29' based on the image density detected by the sensor 26, film thickness detected by the core discriminating switch 46 and sheet thickness detected by the sensor 43; and on/off control of the cutter motor for cutting the laminated transfer sheet.
The fetching of input signals, on/off control of the loads, and load control based on the predetermined values are conducted according to a program stored in the ROM of the microcomputer 70.
In the following there will be explained speed control of the main motor 51.
In the lamination of the transfer sheet 10, the amount of heat absorption of said sheet 10 increases with the increase in density of the sheet 10. Stated otherwise, more heat is absorbed in a darker sheet. Consequently, if the heating condition of the laminating heaters 29, 29' for the laminating films 28, 28' is constant, the transport speed of said laminating films 28, 28' and of the transfer sheet 10 has to be made lower (by a slower rotating speed of the main motor 51), in order to obtain satisfactory lamination. Namely, in consideration of the amount of heat of the laminating films 28, 28' absorbed by the transfer sheet 10 at the pressure rollers 30, 30', it is necessary to increase the heat absorption of the sheet 10 by prolonging the heating time with the heaters 29, 29'.
Also the transport speed of the laminating films 28, 28' and the transfer sheet 10 has to be made slower for a larger thickness of the transfer sheet 10, as the amount of heat absorption of the transfer sheet 10 increases for a larger thickness.
Furthermore, said transport speed has to be made slower for a larger thickness of the laminating films 28, 28', since the amount of heat absorption of said films likewise increases.
Consequently, in the laminating apparatus C of the present embodiment, the transport speed of the transfer sheet 10 and the laminating films 28, 28' can be controlled according to the image density and thickness of the transfer sheet 10, and the thickness of the laminating films 28, 28', by feedback of the data from the density detecting sensor 26, sheet thickness sensor 43 and core discriminating switch 46 to the rotating speed of the main motor 51.
More specifically, as shown in FIG. 5, at least one of an image density signal detected by the density detecting sensor 26, a laminating film thickness signal detected by the core discriminating switch 46, and a sheet thickness signal detected by the sheet thickness sensor 43 is supplied to the control circuit 70, which in response discriminates the total heat capacity of the, transfer sheet and the laminating films. Thus the control circuit 70 controls the rotating speed of the main motor 51, thereby regulating the transport speed of the transfer sheet and the laminating films, in order to provide the laminating films, by means of the laminating heaters 29, 29', with thermal energy enough for lamination corresponding to said total heat capacity. Thus, for a large or small total heat capacity, the transport speed is respectively decreased or increased in order to provide the laminating films with larger or smaller amount of thermal energy.
In the following there will be explained temperature control of the laminating heaters 29, 29'.
Just like the speed control of the main motor 51 explained above, the temperature of the laminating heaters 29, 29' has to be controlled according to the image density of the transfer sheet 10 and thickness of said sheet 10 and of the laminating films 28, 28' because the amount of heat absorption by the laminating films 28, 28' varies. More specifically, the temperature of said heaters 29, 29' has to be elevated for increasing the amount of heat energy supply as the image density, thickness of the transfer sheet 10 or thickness of the laminating films 28, 28' increases.
Consequently, in the laminating apparatus C of the present embodiment, the temperature of the laminating heaters 29, 29' is feedback controlled by the data from the density detecting sensor 26, sheet thickness sensor 43 and core discriminating switch 46.
More specifically, as shown in FIG. 5, at least one of the image density signal detected by the density detecting sensor 26, the laminating film thickness signal detected by the core discriminating switch 46 and the sheet thickness signal detected by the sheet thickness sensor 43 is supplied to the control circuit 70, which in response discriminates the total heat capacity of the transfer sheet and the laminating films. Thus the control circuit 70 controls the temperature of the laminating heaters 29, 29', in order to provide the laminating films, by means of the laminating heaters 29, 29', with enough thermal energy for lamination corresponding to said total heat capacity. Thus, for a large or small total heat capacity, the temperature of the laminating heaters 29, 29' is respectively increased or decreased for increasing or decreasing the amount of thermal energy given to the laminating films.
The above-explained transport speed control and heater control corresponding to the thermal capacity of the transfer sheet and the laminating films may be employed singly or in combination.
In the following there will be explained on/off control and temperature control of the transfer sheet heater 25.
In image formation with ink in an image forming apparatus to be explained later in relation to FIG. 6, the transfer sheet 10 is discharged from said apparatus in a wet state with undried ink. If the sheet is laminated in such wet state, moisture will be sealed between the upper and lower laminating films 28, 28', thus forming bubbles and undesirably affect the appearance of the laminate. It is therefore necessary to heat the transfer sheet 10 prior to lamination, thereby evaporating the moisture therein.
However, excessive heating will cause curling of the transfer sheet 10, eventually leading to creases or curling of the obtained laminate. The wet level of the sheet 10 depends on the image density, and a higher image density is more inconvenient for lamination.
In the laminating apparatus of the present embodiment, therefore, the heating temperature can be automatically controlled according to the image density detected in advance by the density detecting sensor 26. More specifically, the temperature of the transfer sheet heater 25 is set higher or lower respectively for a higher or lower image density. On the other hand, certain image forming apparatus form the image with toner instead of ink, and the transfer sheet in such image forming apparatus is discharged in a dry state. In such case the heating prior to lamination is unnecessary. Consequently the operator can turn off the heater with a switch provided in the operation unit 17.
The transfer sheet heater is controlled in the following manner. The image density signal detected by the density detecting sensor 26 shown in FIG. 5 is supplied to the control circuit 70, which in response controls the temperature of the transfer sheet heater 25. In the foregoing embodiment there are employed heaters for drying the transfer sheet, but the drying may also be achieved by sending air to the surface of the transfer sheet for example with a fan, and the revolution of said fan is controlled in such case. Also the image density may be detected by a sensor for detecting the density of the original read by the reader A.
FIG. 6 shows an embodiment in which the image forming means of the printer B of the foregoing embodiment is replaced by an ink jet recording apparatus.
Referring to FIG. 6, there are shown rollers 101, 102 for transporting the transfer sheet; an ink jet head 103 for image formation by emitting ink droplets onto a sheet; and a carriage 104 supporting said ink jet recording head 103 and adapted to reciprocate along a guide member 105 in a direction perpendicular to the sheet transporting direction.
FIG. 7 shows a bubble jet recording head, as an example of the ink jet recording head, in an exploded perspective view.
Referring to FIG. 7, a heater board 111 is composed of a silicon substrate, provided thereon with electrothermal converters (discharge heaters 112), and electrodes 113 for example of aluminum for supplying said electrothermal converters with electric power. A recording head 103 is formed by adhering, to said heater board 111, a cover plate 115 having partitions for separating liquid paths 114 (nozzles) for the recording liquid. Also in a predetermined position of the apparatus, a replaceable ink cartridge is mounted for supplying said recording head 103 with the ink (recording liquid).
The ink supplied from said ink cartridge through a pipe is introduced, through a supply aperture 116 provided in the cover plate 115, into a common liquid chamber 117 of the recording head 103, and is further guided from said chamber into the nozzles 114. Said nozzles 114 are respectively provided with ink discharge apertures 118, which are arranged on a face of the recording head 103 opposite to the recording sheet, with a constant pitch in the sheet transporting direction.
In the present embodiment, recording is achieved by discharging the ink from the recording head 103 in synchronization with the movement of the carriage 104.
The principle of ink discharge in the aboveexplained bubble jet recording method is disclosed for example in the U.S. Pat. Nos. 4,723,129 and 4,740,796.
Said principle will be briefly explained with reference to FIGS. 8A to 8G. In a stationary state shown in FIG. 8A, the ink 120 filled in the nozzle 114 is in equilibrium of the surface tension and the external pressure at the face of discharge opening. In order to discharge the ink 120 from this state, electric power is supplied to the electrothermal converter 112 in the nozzle 114, thereby inducing rapid temperature increase exceeding nucleus boiling in the ink in said nozzle 114. Thus, as shown in FIG. 8B, the ink positioned adjacent to the electrothermal converter 112 generates small bubbles by heating, and is gasified to generate membrane boiling, whereby said bubbles 121 grow rapidly as shown in FIG. 8C.
When the bubble 121 grows to a maximum as shown in FIG. 8D, an ink droplet is pushed out from the discharge opening of the nozzle 114. When the power supply to the electrothermal converter 112 is terminated, the bubble 121 contracts as shown in FIG. 4E by cooling with the ink 120 in the nozzle 114, and an ink droplet is discharged by the growth and contraction of said bubble. The electrothermal converter 112 is rapidly cooled in contact with the ink, whereby the bubble 121 either disappears or contracts to a negligible volume, as shown in FIG. 8F. Upon said contraction of the bubble 121, the ink is replenished by capillary action into the nozzle 114 from the common liquid chamber 117, as shown in FIG. 8G, thereby preparing for the next electric power supply.
Thus an ink image is recorded on the recording sheet, by energization of the electrothermal converters 112 according to image signals and in synchronization with the reciprocating motion of the carriage 104.
In the above-explained ink jet recording method, recovery means is preferably provided at an end portion of the moving range of the carriage. Said recovery means serves to prevent ink drying or solidification in the vicinity of discharge openings of the recording head 103, by covering the ink discharge face of said recording head 103 in the non-recording state. Also said recovery means may be connected to a pump for sucking ink out of the discharge openings, for the purpose of rectifying or preventing ink discharge failure.
Also in the embodiment shown in FIGS. 6 to 8, as in the foregoing embodiments, the control circuit shown in FIG. 5 controls the transport speed of the recording sheet, the laminating heaters 29, 29' and the sheet heater 25.
In the foregoing embodiments there are provided the laminating films on both sides of the transfer sheet, but there may be provided only one laminating film on a side (image bearing face) of the transfer sheet.
Also the laminating heaters 29, 29' and the sheet heater 25 are controlled by temperature in the foregoing embodiments, but the method of control is not limited to such embodiments and can be controlled in any manner as to vary the amount of thermal energy supply. For example, the amount of thermal energy supply may be varied by varying the number of energized ones in plural heaters.
FIG. 9 shows another embodiment, which is different from the foregoing embodiments shown in FIGS. 1 to 6, in that pressure-sensitive adhesive is employed in one of the laminating films.
In FIG. 9, a laminating film roll 28 employs heat-sensitive adhesive coated on the external surface, while a laminating film roll 28' employs pressure-sensitive adhesive coated on the external surface. A laminating heater 29 is provided for heating the heat-sensitive laminating film 28, which becomes adhesive upon heating. Said heater 29 has a curved surface for heating the film over a wide area. The temperature of said heater is rendered variable by a sensor provided at the surface of said heater.
Pressure rollers 30, 30' effect the lamination of the recording sheet, by pressing said sheet between the laminating film 28 heated by the laminating heater 29 and the laminating film 28' coated with the pressure-sensitive adhesive. Said laminating film 28' coated with the pressure-sensitive adhesive becomes adhesive by the pressure exerted by the pressure rollers 30, 30'. A guide roller 71 is provided for guiding the laminating film 28'.
In the present embodiment, the heat-sensitive laminating film with glossy surface is adhered to the image bearing face of the recording sheet, while the non-glossy pressure-sensitive laminating film of low rigidity, not requiring heating,, is adhered to the image-free face, which is less affected by the draw-backs of the laminating film, whereby the electric power consumption of the laminating apparatus can be reduced without undesirable influence on the image bearing face.
Other structures and controls of the present embodiment are same as those in the foregoing embodiments shown in FIGS. 1 and 6.
In the above-mentioned embodiment, the density detecting sensor 26 which detects density of image is used for means for detecting humidified degree of the transfer sheet. However, it is possible to provide a temperature sensor 150 (FIG. 5) which detects the humidity in the area surrounding on the apparatus since the transfer sheet gets humid in response to humidity so that control circuit 70 controls humidity of the transfer sheet heater 25 in response to the detected signal of the humidity sensor 150.
In addition, it is possible to measure electric resistance of the transfer sheet to check humidified degree. Concretely, two electrodes are provided so as to contact the transfer sheet in the cassette 9 or in the conveying path, out-put of the resistance sensor 151 which detects resistance between both electrodes is inputted to the control circuit 70, so that the control circuit 70 controls humidity of transfer sheet heater 25 in response to the outputted resistance signal. According to such construction, the present invention can be applied to the sheet on which image is formed by the image forming means other than the ink jet system. | A laminating apparatus comprises a sheet transporter for transporting a sheet, a laminating film transporter for transporting at least one laminating film in such a manner that the laminating film is superposed with at least one surface of the sheet transported by the sheet transporter, a pressing mechanism for pressing the sheet and the laminating film in a mutually superposed state, a dryer for drying the sheet before it is superposed with the laminating film, a humidity detector for detecting the humidity of the sheet, and a controller for controlling the dryer according to a detection signal from the humidity detector. | 8 |
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