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REFERENCE TO PRIOR PROVISIONAL APPLICATIONS
[0001] This application claims the benefit of prior copending provisional applications Serial No. 60/380,941, and 60/380,925, both filed May 17, 2002.
BACKGROUND OF THE INVENTION
[0002] This invention relates to traffic signals for controlling traffic flow at intersections of roadways, and relates more particularly to systems that modify traffic signal operation in response to emergency vehicle signals to permit the emergency vehicle to pass quickly and safely through the intersection, and to methods of controlling such signals.
[0003] Traffic signals have been used for many years to regulate traffic flow at intersections, typically providing a green or “go” light for traffic on one street at preselected intervals while providing traffic on the intersecting street with a red or “stop” light. During the transition from “go” to “stop”, it is customary to provide a yellow or “caution” light for a short interval, warning oncoming motorists to prepare to stop when the red light appears. All three lights often are mounted in a common housing or frame, usually in a vertical row but sometimes horizontally aligned.
[0004] When an emergency vehicle such as a police car, fire truck or ambulance must pass rapidly through an intersection, the oncoming emergency vehicle typically sounds an audible warning such as a siren and a visual warning such as a flashing light, and then proceeds through the intersection without regard to the existing condition of the traffic signal. For various reasons, these signals are not always sufficient to avoid collisions. Loud noises, closed vehicles with radios or other audio devices playing, and inattentive drivers in some instances lead to dangerous situations in which cross traffic does not stop for the oncoming emergency vehicle, with resulting collisions.
[0005] A variety of devices have been proposed to allow emergency vehicles to control traffic signals. These typically use radio transmitter systems for activating emergency preemption controls on the traffic signals that will override the normal controls of the signals and provide “stop” signals for cross traffic approaching the intersection and continuous “go” signals for the emergency vehicle. Other special signals have been provided in efforts to provide information to affected drivers regarding the presence and direction of approach of emergency vehicles, whether on intersecting streets or from one direction or the other on the same street. Such systems and devices are well known, and examples are shown in U.S. Pat. Nos. 4,775,865 and 4,704,610 (signs beside traffic signals with vehicle symbols for indicating approaching emergency vehicles); U.S. Pat. No. 6,292,109 (display at corner of intersection with sign shown in FIG. 6 having arrows indicating the direction of an approaching vehicle, a traffic signal with a siren and a flashing red emergency light); and U.S. Pat. No. 6,362,749 (signal device installed in vehicles and having arrows for indicating the direction of the signal from an approaching emergency vehicle, which also could be installed in an undisclosed manner on a traffic signal).
[0006] Unfortunately, these prior devices, systems and methods have provided ambiguous and sometimes confusing information and often have been so complex and expensive in construction that they have not been universally installed. Others have been unreliable in operation and have required substantial time and money for maintenance. Accordingly, there has been an ongoing need for an improved and more effective emergency traffic signal device that will overcome the deficiencies of the prior art systems and devices.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention resides in a novel traffic signal device that can be either attached to existing traffic signals or installed in newly constructed signals, and is effective to provide improved visual warning communications to drivers regarding the approach of an emergency vehicle and the actions that are required to avoid the emergency vehicle, and the accompanying method of controlling the traffic signal. For these purposes, a first embodiment of the invention comprises an attachment to the frame or housing of the traffic signal with a special panel that overlies one if the lamps, herein the “green” signal lamp, and is transparent so as to pass the regular light during normal operations, but is electro-optically responsive to an emergency signal to display either a “stop” signal over the regular light, if the emergency vehicle is approaching on a cross street, or a lateral directional movement signal if the vehicle is approaching on the same street. In this manner, traffic not only is warned to stop but also is informed when movement to the side of the roadway is needed. The “stop” signal may be simply a red light superimposed over the regular light of the traffic signal or may be a graphic “halt” or “stop” symbol.
[0008] A second, preferred embodiment provides an attachment to the existing frame or housing as a replacement for one of the lamps, and substitutes for the regular lamp a combination LED array that can display the normal color signals (green, yellow or red) during normal operation, and, when activated by an emergency signal, will display a selected emergency signal as in the first embodiment. The graphic directional signal also may be a moving “chevron” or arrow directional signal, or also can be a graphic “hand” symbol indicating direction as well.
[0009] In both embodiments, the method of operation comprises the steps of providing the inventive attachment and then controlling the attachment to provide messages in the novel manner described.
[0010] Other aspects and advantages of the present invention will be evident from the following drawings, taken in conjunction with the accompanying detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a enlarged fragmentary perspective view showing a portion of an approaching emergency vehicle, not to scale, and a representative traffic signal equipped with an emergency traffic signal device in accordance with a first embodiment of the present invention;
[0012] [0012]FIG. 2 is an enlarged side elevational view of the emergency signal device of FIG. 1, partially broken away and shown in cross-section;
[0013] [0013]FIG. 3 is a side elevational view of the electro-optically responsive panel of the emergency signal device of FIG. 1;
[0014] [0014]FIG. 4 is a perspective view similar to FIG. 1 with a different message on the display panel;
[0015] [0015]FIG. 5 is a perspective view of an improved display device that is a second embodiment of the invention; and
[0016] [0016]FIGS. 6, 7 and 8 are front elevational views illustrating alternative arrangements and signals that may be provided with the emergency signal device of the present invention.
DETAILED DESCRIPTION
[0017] As shown in the drawings for purposes of illustration, the invention is embodied in an attachment 10 that is mounted on the green or “go” lamp 11 of a conventional traffic signal 12 also having red and yellow lamps 13 and 14 , each comprising a suitable light source (not shown) and an open-ended shroud or shade. A representative emergency vehicle 15 is shown in a position approaching the traffic signal 12 and having a transmitter 17 of a conventional type for actuating the emergency control system. A controller 18 is enclosed in a housing on one side of the signal attachment and receives the transmitted radio signal through an antenna 19 . The controller electronically actuates various features of the invention in response to the radio signals received from emergency vehicles that are travelling on the same street or on an intersecting street. The details of construction, electronics and operation of such controllers in these systems are known, as is indicated in the several patents that are identified in the background of this invention.
[0018] It has been customary in past systems of this type to enable the emergency vehicles to control the normal, “stop” and “go” signals of the intersection. In addition, some systems sometimes provide signals that indicate the direction of an approaching emergency vehicle and enable drivers of other automobiles, trucks and the like, and even other emergency vehicles, to make decisions as to appropriate evasive actions to avoid interference, or even a collision, with the vehicle that is sending the emergency signal. Typically, as indicated in the cited prior patents, such signals indicate, at most, the direction from which the emergency vehicle is approaching, and leave it to the other drivers to decide what kind of evasive action is appropriate.
[0019] In accordance with the present invention, the attachment 10 is an improved emergency signal device that provides clear and unambiguous information to drivers as to the specific action or actions needed to avoid the oncoming emergency vehicle. In addition, the improved device is relatively simple and inexpensive in construction and may be economically retrofitted to existing traffic signals as a self-contained unit or provided as an original component of a new traffic signal that is to be installed.
[0020] For these purposes, the attachment 10 herein is fitted onto one of the three standard lamps 11 , 13 and 14 , herein the lower or “go” lamp 11 of the signal 12 , and has a special panel 20 forming a lens or cover for the pre-existing lens 21 of the lamp, a special red light source 22 , and a data display panel 23 on one side of the lamp for providing directional information. The attachment 10 is operable when activated to block out the normal green light of the lower lamp 11 , to energize the special red light source 22 which is reflected toward oncoming traffic by the special panel 20 , and to activate the data display panel 23 to provide a selected directional message determined by the controller 18 in response to the directional signal from the emergency vehicle.
[0021] More specifically, the attachment 10 has a housing that is formed with a tubular upper portion 24 for fitting tightly over the open end of the shade of one of the lamps, herein the lower lamp 11 , as shown in FIGS. 1 and 2. The special panel 20 is normally is transparent to the green light and is positioned in front of the regular lens 21 , and the special red light source 22 is a series of red lights, such as red-light emitting diodes (LEDs), that are spaced around the open outer side of the tubular portion of the housing, on the side of the special lens panel 20 opposite the regular lens 21 .
[0022] The special panel 20 of the first embodiment is constructed in multiple laminated layers, herein three indicated at 20 a , 20 b and 20 c in FIG. 3, with the first or outer layer 20 a having a reflective outside surface but capable of passing light from the regular lamp when the attachment is not activated. Thus, this layer will reflect the red light from the LEDs 30 when the latter are energized. The inside layer 20 b of the special lens is electro-optically active material that is opaque when activated, thereby to block the normal light from the regular lens 21 . The third layer is transparent and, with the outer layer 20 a , supports the electro-optically active inside layer 20 b.
[0023] With this arrangement, the normal signals from the green light of the traffic signal can be overridden and converted to a red light to signal that traffic approaching the signal is to stop, regardless of the condition of the normal green lamp 11 . This is the mode to be used when an emergency vehicle is approaching on an intersecting street and all that is needed of the traffic approaching the signal is to stop at the intersection.
[0024] The data display panel 23 is mounted in the housing on one side of the special panel 20 , typically either below the panel or to one lateral side, and has the capability of enhancing visual communication with drivers. For this purpose, the display panel also is electro-optically active, preferably in the form of an array of selectively energized LEDs covering virtually the entire panel and capable of providing alternating graphic and/or verbal displays on the panel. For example, as shown in FIG. 1, one display that is appropriate to accompany the red “stop” signal superimposed over the green lamp is the word “STOP” or the abbreviation “STP” that is shown on the display panel. This augments the signal given by the red light. Alternatively, the panel can be made to display the “halt” graphic symbol that is shown on the panel in the alternative embodiment of FIG. 6. This symbol is universally recognizable as meaning “do not pass”, as is appropriate when the emergency signal is coming from a vehicle travelling on an intersecting street.
[0025] For use in controlling traffic signals on the street on which the emergency vehicle is travelling, the graphic signal on the display panel 23 will give directional information such as an arrow pointing toward the right-hand side of the street, to direct traffic toward the curb, as shown in FIG. 4. This can be coupled with the verbal message “RIGHT”, or an abbreviation such as “RGT”, as shown on the panel in FIG. 4. Further, for better attention-getting quality, the LEDs in the display panel 18 can be illuminated in a “chevron” pattern, as shown with “RGT” and the arrow symbol in FIG. 4, and the “chevron” pattern can be made to appear to move from left to right, through. sequential control of the pattern of illumination of the LEDs. Again, this can be accomplished by the controller 18 in a manner that is well known to those skilled in the art.
[0026] Thus, the first embodiment of the invention comprises an attachment with the ability to override the regular “green” signal of a traffic light with a constant “red” until the emergency vehicle passes, and also with the ability to provide a verbal and/or graphic directional signal ordering drivers either to stop or to pull laterally toward the curb. These two signals typically will be combined, but can be given separately as well. Since this attachment is designed to override the normal green “go” signals, it normally is fitted over the lower lamp 11 of vertically aligned lamps as shown in FIG. 1, but also can be placed in other positions as shown in connection with the second embodiment, to be described.
[0027] It is to be understood that the antenna 19 is connected by electrical circuitry (not shown) to the controller 18 inside the attachment housing, only the switch panel 25 of the controller being exposed in FIGS. 1, 2 and 4 . A compass or other directional instrument 26 is shown on the attachment to assist in orienting the attachment and the controller should directional information be required. The controller has the capability of determining the direction from which a detected signal is coming, thus determining the appropriate actions to be initiated for the signal device.
[0028] In addition, the invention is illustrated by a second attachment 35 (FIGS. 5 - 8 ), in which a special lamp panel 37 of the general type shown in the first embodiment at 20 provides graphic directional signals as well as color signals to instruct motorists regarding necessary actions. This panel is electro-optically responsive to signals from approaching emergency vehicles to produce either a “stop” signal or a directional signal such as a moving “chevron” pattern directing the motorist toward the curb. In the U.S., this will be the right-hand side as shown in FIG. 5. A graphic “hand” design pointing to the right (not shown) may be provided instead of, or in combination with, such a “chevron” symbol for additional attention-getting impact and communication. To provide these features of operation, the special panel 27 of the alternative attachment 35 is formed as a flat array of LEDs capable of producing contrasting patterns, such as red on a dark background and at least one solid pattern, such as green or yellow, and the controller indicated generally at 38 , as in FIGS. 1 and 2, is programmable in a manner well known in the electro-optical arts to produce the desired color or graphic pattern on command. Thus, in the normal operating condition of the traffic signal equipped with the attachment 35 (as a total replacement for the normal lamp), the lamp panel 37 produces the regular signal in the proper sequence, green-colored if the attachment is mounted in the lower, “go” position at 11 as shown in FIG. 6 or yellow-colored if the attachment is mounted in the central “caution” position at 13 as shown in FIG. 7. LEDs of the appropriate color are energized by the controller 25 in the proper regular sequence. In such normal operation, the special display panel indicated generally at 39 can be left blank.
[0029] When the controller 38 receives an emergency signal, however, the special lamp panel 37 is energized by the controller 38 to produce the selected graphic and color signals and to terminate the normal color display, as appropriate. For example, when the emergency signal is received from a vehicle travelling in either direction on the same street as the receiving vehicle, the chevron signal shown in FIG. 5 is activated, along with the “RGT” and chevron graphic display shown in FIG. 5. The chevron symbols may be sequentially controlled for even greater impact and clearer meaning. This also is illustrated in different lamp positions in FIGS. 7 and 8.
[0030] If the emergency signal is received from an emergency vehicle approaching the intersection on the intersecting street, the controller 38 activates the lamp panel 37 and the data panel 39 in a different manner, because movement of vehicles toward the curb is not the desired response. The controller produces a red, or “stop” signal by activating red light-emitting LEDs in the lamp panel 37 , with the accompanying graphic instructional display on a data panel 39 .
[0031] As an incidental benefit of the presence of the data panel on the traffic light, it is possible to program the controller to receive and display emergency messages of different kinds, such as the well known “Amber Alert” messages. The only limitation in this respect is the size and available space of the data panel, since compactness is a desirable feature.
[0032] Accordingly, it will be seen that the invention provides greatly improved directions to motorists in response to the preemptive traffic control signals from approaching emergency vehicles, with an attachment that can be retrofitted to an existing traffic signal in a simple and relatively inexpensive manner to perform the steps of the method of the invention. It also will be evident that the embodiments disclosed are merely illustrative of the invention and that various modifications and changes may be made within the scope of the invention.
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An attachment for a traffic signal having a housing for fitting over one of the normal lights, herein the green light, of the signal and overriding the normal sequence in response to preemptive emergency signals, and a electro-optically responsive data display panel on the housing to provide clear and direct instructional messages to motorists as to the appropriate actions to be taken. A first embodiment overrides the normal green light with a reflective electro-optically responsive panel overlying the normal green light to become opaque in response to the emergency signals, with a red light source outside the panel that is activated to produce red reflected light. A second embodiment replaces the normal green (or alternatively yellow or red) signal with a panel of light-emitting elements (LEDs) that have one group capable of providing the normal green signals and a second group that are capable of providing graphic instructions in response to emergency signals. In both embodiments, the display panels provide alternate selections such as “STOP” or a halt symbol as one selection and an arrow or chevron pattern, with “RIGHT” or an abbreviation as a second selection.
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CLAIM OF PRIORITY
[0001] This application claims the benefit of U.S. Provisional Patent Application 61/352,274, entitled “Methods and systems for resolving conflicting client/server data in a multi-tenant database environment,” by Movida et al, filed Jun. 7, 2010, the entire contents of which are incorporated herein by reference.
COPYRIGHT NOTICE
[0002] A portion of the disclosure of this patent document contains material which 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 file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
[0003] One or more implementations relate generally to data storage, and more particularly to data synchronization.
BACKGROUND
[0004] The subject matter discussed in the background section should not be assumed to be prior on merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
[0005] Conventional systems may desire to store one or more copies of data in a plurality of locations. For example, identical data records may be stored both at a client of a system as well as a server of the system, and may be periodically synchronized (e.g., for purposes of maintaining updated data, etc.). Unfortunately, traditional data synchronization techniques have been associated with various limitations.
[0006] Just by way of example, conflict may arise during the synchronization of data between locations. For example, alterations may have been made simultaneously to the same data elements at different locations. Accordingly, it is desirable to effectively manage and resolve such data conflicts.
BRIEF SUMMARY
[0007] In accordance with embodiments, there are provided mechanisms and methods for resolving a data conflict. These mechanisms and methods for resolving a data conflict can enable an improved user experience, increased efficiency, time savings, etc.
[0008] In an embodiment and by way of example, a method for resolving a data conflict is provided. In one embodiment, a synchronization error is detected within a system. Additionally, it is determined that the synchronization error includes a data conflict. Further, the data conflict is resolved.
[0009] While one or more implementations and techniques are described with reference to an embodiment in which resolving a data conflict is implemented in a system having an application server providing a front end for an on-demand database system capable of supporting multiple tenants, the one or more implementations and techniques are not limited to multi-tenant databases nor deployment on application servers. Embodiments may be practiced using other database architectures, i.e., ORACLE®, DB2® by IBM and the like without departing from the scope of the embodiments claimed.
[0010] Any of the above embodiments may be used alone or together with one another in any combination. The one or more implementations encompassed within this specification may also include embodiments that are only partially mentioned or alluded to or are not mentioned or alluded to at all in this brief summary or in the abstract. Although various embodiments may have been motivated by various deficiencies with the prior art, which may be discussed or alluded to in one or more places in the specification, the embodiments do not necessarily address any of these deficiencies. In other words, different embodiments may address different deficiencies that may be discussed in the specification. Some embodiments may only partially address some deficiencies or just one deficiency that may be discussed in the specification, and some embodiments may not address any of these deficiencies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the following drawings like reference numbers are used to refer to like elements. Although the following figures depict various examples, the one or more implementations are not limited to the examples depicted in the figures.
[0012] FIG. 1 illustrates a method for resolving a data conflict, in accordance with one embodiment;
[0013] FIG. 2 illustrates method for performing error detection, in accordance with another embodiment;
[0014] FIG. 3 illustrates an example of an icon on top of a synchronization button, in accordance with another embodiment;
[0015] FIG. 4 illustrates a conflict overview screen of a conflict resolution user interface, in accordance with another embodiment;
[0016] FIG. 5 illustrates a conflict error screen of a conflict resolution user interface, in accordance with another embodiment;
[0017] FIG. 6 illustrates a conflict summary screen of a conflict resolution user int rface, accordance with another embodiment;
[0018] FIG. 7 illustrates a block diagram of an example of an environment wherein an on-demand database system might be used; and
[0019] FIG. 8 illustrates a block diagram of an embodiment of elements of FIG. 7 and various possible interconnections between these elements.
DETAILED DESCRIPTION
General Overview
[0020] Systems and methods are provided for resolving a data conflict.
[0021] As used herein, the term multi-tenant database system refers to those systems in which various elements of hardware and software of the database system may be shared by one or more customers. For example, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows for a potentially much greater number of customers.
[0022] Next, mechanisms and methods for resolving a data conflict will be described with reference to example embodiments.
[0023] FIG. 1 illustrates a method 100 for resolving a data conflict, in accordance with one embodiment. As shown in operation 102 , a synchronization error is detected within a system. In one embodiment, the system may include one or more clients. For example, the system may include a desktop computer, a laptop computer, a handheld device (e.g., a cell phone, personal digital assistant (PDA), etc.), or any other device capable of performing computation. In another embodiment, the system may include one or more servers. For example, the system may include one or more server computers, a cloud computing environment, a multi-tenant on-demand database system, etc. In yet another embodiment, the one or more clients and the one or more servers of the system may communicate utilizing a network.
[0024] Additionally, in one embodiment, the synchronization may include the exchange of data between a client of the system and a server of the system. For example, a copy of the same data may be stored at both the client and the server of the system, and both copies may be periodically synchronized. In this way, it may be ensured that the stored data is accurate and current. In another embodiment, the synchronization may be performed utilizing one or more application programming interface (API) calls. In yet another embodiment, the synchronization may be performed in response to data being saved within the system (e.g., at the client, at the server, etc.).
[0025] Further, in one embodiment, the synchronization error may include any error that is encountered during synchronization. For example, the synchronization error may include one or more failed API calls. In another embodiment, a message may accompany the synchronization error. For example, an error message may be received in response to a failed synchronization between a client and server within the system.
[0026] Further still, it should be noted that, as described above, such multi-tenant on-demand database system may include any service that relies on a database system that is accessible over a network, in which various elements of hardware and software of the database system may be shared by one or more customers (e.g. tenants). For instance, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows for a potentially much greater number of customers. Various examples of such a multi-tenant on-demand database system will be set forth in the context of different embodiments that will be described during reference to subsequent figures.
[0027] Also, as shown in operation 104 , it is determined that the synchronization error includes a data conflict. In one embodiment, it may be determined that the synchronization error includes a data conflict by identifying an error message. For example, an error message (e.g., an error code, a message string, etc.) received in response to the synchronization error may indicate that such synchronization error is the result of a data conflict. Of course, however, the synchronization error may be determined to include a data conflict in any manner. In another embodiment, the determining may be performed by a fault handler of the system.
[0028] Additionally, in one embodiment, the data conflict may include a conflict of data between a server of the system and a client of the system. For example, identical copies of data may be stored at both the client and the server of the system, and after a first synchronization is performed, the data copy stored on the client may be altered (e.g., by a user editing the data, deleting the data, etc.). Additionally, after the first synchronization is performed, the data copy stored on the server may also be altered in a different manner than the data copy stored on the client. In another example, the data copy stored on the server may be altered before the alteration of the data copy on the client, after the alteration of the data copy on the client, at the same time as the alteration of the data copy on the client, etc.
[0029] Further, in one embodiment, during a second synchronization of the data with the server after the first synchronization, it may be determined that both the copy of the data on the client and the copy of the data on the server have been separately altered since the last synchronization of the data between the server and the client.
[0030] Further still, a shown in operation 106 , the data conflict is resolved. In one embodiment, resolving the data conflict may include determining which of two conflicting copies of data is to be stored within the system. For example, if identical copies of data stored on both a client and server of a system are both independently altered before a synchronization is performed, resolving the data conflict may include determining whether the data copy stored on the client or the data copy stored on the server is to be saved in the system, whether both data copies are to be saved in the system, etc.
[0031] Also, in one embodiment, the data conflict may be resolved utilizing a user interface (UI). For example, the data conflict may be presented to, and manually resolved by, a user of the system utilizing a conflict resolution UI. In another embodiment, the may list a plurality of data conflicts, and the user may choose which data conflicts to manually address. In yet another embodiment, the user may select from one or more possible resolutions for the data conflict from within the UI. In still another embodiment, the user may perform one or more additional operations associated with resolving the data conflict utilizing the UI. For example, the user may send a message to another entity within the system regarding the conflict. In another example, the user may save a copy of the chosen resolution of the data conflict within the system. In this way, the user interface may assist the user in manually resolving the data conflict.
[0032] In addition, in one embodiment, the data conflict may be resolved automatically. For example one or more programs may be created utilizing a toolkit as part of an application programming interface (API) to address the data conflict. In another embodiment, the one or more programs may automatically resolve the data conflict based on one or more criteria. For example, the one or more programs may resolve the data conflict based on a time and date of data modification, entity priority within the system, the type of data in conflict, an organization associated with the data, etc. In this way, the data conflict may be included within a large volume of data conflicts which may be automatically resolved by the one or more programs and may not have to be manually addressed by a user of the system.
[0033] FIG. 2 illustrates a method 200 for performing error detection, in accordance with another embodiment. As an option, the method 200 may be carried out in the context of the functionality of FIG. 1 . Of course, however, the method 200 may be carried out in any desired environment. The aforementioned definitions may apply during the present description.
[0034] As shown in operation 202 , a data management service (DMS) receives an error message in response to a system web service call. In one embodiment, the system web service call may include a request to synchronize data between a client and server of the system. In another embodiment, the error message may be received after the request to synchronize the data has failed. In yet another embodiment, the error message may be received in response to replaying an uncommitted queue during an online commit, where a data service adapter may invoke a web service API calls.
[0035] Additionally, as shown in operation 204 , the database management service calls a system data service adapter with the error message. Further, as shown in operation 206 , the data service adapter asks a fault handler to handle the error, based on the web service call. Further still, as shown in operation 208 , the fault handler conditionally retrieves the original item associated with the web service call from the server to determine the nature of the fault. In one embodiment, the decision may be based on a type of the web service call involved, the error message (e.g., an error code within the error message, etc.), etc. In this way, unnecessary operations may be avoided (e.g., attempting to access an item from the server that the error code notes has been deleted from the server, etc.).
[0036] Also, as shown in operation 210 , the fault is determined to be a conflict. For example, it may be determined that identical copies of a file stored at both a client and a server of the system have each been modified independently of each other after a synchronization including those files has been performed. In another example, it may be determined that data that is attempted to be modified has been modified on the server since the last synchronization. In one embodiment, the determination may be made by retrieving the data associated from the web service call from a client and server of the system, comparing the data, and determining that such data is different at the server and client.
[0037] In addition, as shown in decision 212 , it is determined whether a fault handler is registered. In one embodiment, the fault handler may be user-defined. For example, a user of the system may utilize one or more of a template, user interface, a system toolkit, and an application programming interface (API) to create a fault handler to resolve conflicts within the system. In another embodiment, the fault handler may include code that makes decisions regarding conflicting data within the system without having to prompt a user.
[0038] Furthermore, if it is determined in decision 212 that a fault handler is registered, then in operation 214 , the conflict is passed to the fault handler. In one embodiment, a conflict or error context may be passed to the fault handler. In another embodiment, one or more fields associated with the conflict may be identified to the fault handler. For example, fields associated with an item that include conflicting data may be identified to the fault handler. In this way, specific information associated with the conflict may be provided to the fault handler. In yet another embodiment, one or more algorithms created by a developer of the system may determine which data is to be saved among the conflicting data.
[0039] For example, the fault handler may apply an algorithm that compares an item at the client to the conflicting item at the server and selects one of the items to be saved to both the client and the server. In one embodiment, the algorithm may default to the data stored at the client or the server. In another embodiment, the algorithm may select the data that has been saved at the latest date. In still another embodiment, the algorithm may select the data based on a type of the data, an organization in which the data is stored, or any other criteria. In this way, the conflict may be programmatically resolved without manual decision-making. In yet another embodiment, the fault handler may revert to the operation that produced the fault, handle the fault in an application (e.g., by displaying an error message on the screen, etc.), put the fault in a conflict queue to be later handled manually, etc.
[0040] Further still, if it is determined in decision 212 that a fault handler is not registered, then in operation 216 the conflict is placed in a conflict queue. Additionally, as shown in operation 218 , the fault is retrieved from the conflict queue and is manually resolved utilizing a conflict resolution user interface (UI). In one embodiment, the conflict resolution UI (CRUI) may allow users to visually resolve conflicts and/or errors which happened during the sync process. For example, when conflicts and/or errors are detected, a status bar at the bottom of an application may display a colored icon on top of a button used to synchronize data. FIG. 3 illustrates an example of an icon 302 on top of a synchronization button 304 . In another example, pressing this button may show the CRUI. In another embodiment, the CRUI may show all the items in the conflict queue and users may have a chance to take action to resolve these conflicts.
[0041] Also, in one embodiment, users may not be forced to resolve conflicts. For example, having unresolved conflicts and/or errors may not preclude users from continuing to work with one or more software applications on a client. In another embodiment, users may continue modifying, creating, and/or deleting items, so long as they are not trying to save an item in conflict.
[0042] FIG. 4 illustrates a conflict overview screen 400 of a conflict resolution user interface, in accordance with another embodiment. As an option, the screen 400 may be carried out in the context of the functionality of FIGS. 1-3 . Of course, however, the screen 400 may be carried out in any desired environment. The aforementioned definitions may apply during the present description.
[0043] As shown, the conflict overview screen 400 allows users to see an overview of all unresolved synchronization conflicts that have occurred by comparing a server value 402 of an object with a client value 404 of the object. In one embodiment, a user may select the “select most recent” icon 406 of the screen 400 , which may select conflicting values that have occurred most recently. In another embodiment, the user may select the “select all server” icon 408 or the “select all client” 410 icon of the screen 400 , which may select conflicting values stored at the server or the client, respectively. In this way, user may resolve conflict globally. In yet another embodiment, users may resolve conflicts by creating blended records (e.g., a mixture of server and client values, etc.).
[0044] FIG. 5 illustrates a conflict error screen 500 of a conflict resolution user interface, in accordance with another embodiment. As an option, the screen 500 may be carried out in the context of the functionality of FIGS. 1-4 . Of course, however, the screen 500 may be carried out in any desired environment. The aforementioned definitions may apply during the present description.
[0045] As shown, the conflict error screen 500 includes an error column 502 . In one embodiment, the error column 502 may provide a detailed view into specific errors and related error messages. Additionally, the conflict error screen 500 includes a client value column 504 . In another embodiment, a user may resolve conflict errors by entering a new/correct value for conflict fields on records within the client value column 504 .
[0046] FIG. 6 illustrates a conflict summary screen 600 of a conflict resolution user interface, in accordance with another embodiment. As an option, the screen 600 may be carried out in the context of the functionality of FIGS. 1-5 . Of course, however, the screen 600 may be carried out in any desired environment The aforementioned definitions may apply during the present description.
[0047] As shown, the conflict summary screen 600 includes a summary column 602 which may include a summary of how a user resolved one or more conflicts. In one embodiment, a user may go back to a previous screen to change selections by selecting the “change selections” icon 604 of the screen 600 . In another embodiment, a user may commit their conflict resolution selections for re-synchronization by selecting the “finish” icon 606 of the screen 600 . In this way, a user may manually resolve data conflicts between a client and server.
[0048] In this way, the system may discriminate between data conflicts and errors, and may provide for resolution through either programmatic or GUYI wizard means. In another embodiment, conflicts and errors discovered by the server may be received, exception information may be correlated to the original records, and the records may be routed to the appropriate handlers. In yet another embodiment, a full GUI wizard may be provided that may guide users through the process of identifying and resolving client/server data conflicts. The wizard may separate the records by type, and then may identify each conflicted field and/or manage conflicts on dependent picklists, etc. The user may be able to select the appropriate client or server value to resolve the conflict. Another path may allow platform developers to specify their own resolution mechanisms. The information relevant to each conflict may be passed to their callback methods through a standardized API and they may be responsible for programmatically indicating how they would like the conflict to be resolved.
System Overview
[0049] FIG. 7 illustrates a block diagram of an environment 710 wherein an on-demand database system might be used. Environment 710 may include user systems 712 , network 714 , system 716 , processor system 717 , application platform 718 , network interface 720 , tenant data storage 722 , system data storage 724 , program code 726 , and process space 728 . In other embodiments, environment 710 may not have all of the components listed and/or may have other elements instead of, or in addition to, those listed above.
[0050] Environment 710 is an environment in which an on-demand database system exists. User system 712 may be any machine or system that is used by a user to access a database user system. For example, any of user systems 712 can be a handheld computing device, a mobile phone, a laptop computer, a work station, and/or a network of computing devices. As illustrated in FIG. 7 (and in more detail in FIG. 8 ) user systems 712 might interact via a network 714 with an on-demand database system, which is system 716 .
[0051] An on-demand database system, such as system 716 , is a database system that is made available to outside users that do not need to necessarily be concerned with building and/or maintaining the database system, hut instead may be available for their use when the users need the database system (e.g., on the demand of the users). Some on-demand database systems may store information from one or more tenants stored into tables of a common database image to form a multi-tenant database system (MTS). Accordingly, “on-demand database system 716 ” and “system 716 ” will be used interchangeably herein. A database image may include one or more database objects. A relational database management system (RDMS) or the equivalent may execute storage and retrieval of information against the database object(s). Application platform 718 may be a framework that allows the applications of system 716 to run, such as the hardware and/or software, e.g., the operating system. In an embodiment, on-demand database system 716 may include an application platform 718 that enables creation, managing and executing one or more applications developed by the provider of the on-demand database system, users accessing the on-demand database system via user systems 712 , or third party application developers accessing the on-demand database system via user systems 712 .
[0052] The users of user systems 712 may differ in their respective capacities, and the capacity of a particular user system 712 might be entirely determined by permissions (permission levels) for the current user. For example, where a salesperson is using a particular user system 712 to interact with system 716 , that user system has the capacities allotted to that salesperson. However, while an administrator is using that user system to interact with system 716 , that user system has the capacities allotted to that administrator. In systems with a hierarchical role model, users at one permission level may have access to applications, data, and database information accessible by a lower permission level user, but may not have access to certain applications, database information, and data accessible by a user at a higher permission level. Thus, different users will have different capabilities with regard to accessing and modifying application and database information, depending on a user's security or permission level.
[0053] Network 714 is any network or combination of networks of devices that communicate with one another. For example, network 714 can be any one or any combination of a LAN (local area network), WAN (wide area network), telephone network, wireless network, point-to-point network, star network, token ring network, hub network, or other appropriate configuration. As the most common type of computer network in current use is a TCP/IP (Transfer Control Protocol and Internet Protocol) network, such as the global internetwork of networks often referred to as the “Internet” with a capital “I,” that network will be used in many of the examples herein. However, it should be understood that the networks that the one or more implementations might use are not so limited, although TCP/IP is a frequently implemented protocol.
[0054] User systems 712 might communicate with system 716 using TCP/IP and, at a higher network level, use other common Internet protocols to communicate, such as HTTP, FTP, AFS. WAP, etc. In an example where HTTP is used, user system 712 might include an HTTP client commonly referred to as a “browser” for sending and receiving HTTP messages to and from an HTTP server at system 716 . Such an HTTP server might be implemented as the sole network interface between system 716 and network 714 , but other techniques might be used as well or instead. In some implementations, the interface between system 716 and network 714 includes load sharing functionality, such as round-robin HTTP request distributors to balance loads and distribute incoming HTTP requests evenly over a plurality of servers. At least as for the users that are accessing that server, each of the plurality of servers has access to the MTS' data however, other alternative configurations may be used instead.
[0055] In one embodiment, system 716 , shown in FIG. 7 , implements a web-based customer relationship management (CRM) system. For example, in one embodiment, system 716 includes application servers configured to implement and execute CRM software applications as well as provide related data, code, forms, webpages and other information to and from user systems 712 and to store to, and retrieve from, a database system related data, objects, and Webpage content. With a multi-tenant system, data for multiple tenants may be stored in the same physical database object, however, tenant data typically is arranged so that data of one tenant is kept logically separate from that of other tenants so that one tenant does not have access to another tenant's data, unless such data is expressly shared. In certain embodiments, system 716 implements applications other than, or in addition to, a CRM application. For example, system 716 may provide tenant access to multiple hosted (standard and custom) applications, including a CRM application. User (or third party developer) applications, which may or may not include CRM, may be supported by the application platform 718 , which manages creation, storage of the applications into one or more database objects and executing of the applications in a virtual machine in the process space of the system 716 .
[0056] One arrangement for elements of system 716 is shown in FIG. 7 , including a network interface 720 , application platform 718 , tenant data storage 722 for tenant data 723 , system data storage 724 for system data 725 accessible to system 716 and possibly multiple tenants, program code 726 for implementing various functions of system 716 , and a process space 728 for executing MTS system processes and tenant-specific processes, such as running applications as part of an application hosting service. Additional processes that may execute on system 716 include database indexing processes.
[0057] Several elements in the system shown in FIG. 7 include conventional, well-known elements that are explained only briefly here. For example, each user system 712 could include a desktop personal computer, workstation, laptop, PDA, cell phone, or any wireless access protocol (WAP) enabled device or any other computing device capable of interfacing directly or indirectly to the Internet or other network connection. User system 712 typically runs an HTTP client, e.g., a browsing program, such as Microsoft's Internet Explorer browser, Netscape's Navigator browser, Opera's browser, or a WAP-enabled browser in the case of a cell phone, PDA or other wireless device, or the like, allowing a user (e.g., subscriber of the multi-tenant database system) of user system 712 to access, process and view information, pages and applications available to it from system 716 over network 714 . Each user system 712 also typically includes one or more user interface devices, such as a keyboard, a mouse, trackball, touch pad, touch screen, pen or the like, for interacting with a graphical user interface (GUI) provided by the browser on a display (e.g., a monitor screen, LCD display, etc.) in conjunction with pages, forms, applications and other information provided by system 716 or other systems or servers. For example, the user interface device can be used to access data and applications hosted by system 716 , and to perform searches on stored data, and otherwise allow a user to interact with various GUI pages that may be presented to a user. As discussed above, embodiments are suitable for use with the Internet, which refers to a specific global internetwork of networks. However, it should be understood that other networks can be used instead of the Internet, such as an intranet, an extranet, a virtual private network (VPN), a non-TCP/IP based network, any LAN or WAN or the like.
[0058] According to one embodiment, each user system 712 and all of its components are operator configurable using applications, such as a browser, including computer code run using a central processing unit such as an Intel Pentium® processor or the like. Similarly, system 716 (and additional instances of an MTS, where more than one is present) and all of their components might be operator configurable using application(s) including computer code to run using a central processing unit such as processor system 717 , which may include an Intel Pentium® processor or the like, and/or multiple processor units. A computer program product embodiment includes a machine-readable storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the embodiments described herein. Computer code for operating and configuring system 716 to intercommunicate and to process webpages, applications and other data and media content as described herein are preferably downloaded and stored on a hard disk, hut the entire program code, or portions thereof, may also be stored in any other volatile or non-volatile memory medium or device as is well known, such as a ROM or RAM, or provided on any media capable of storing program code, such as any type of rotating media including floppy disks, optical discs, digital versatile disk (DVD), compact disk (CD), microdrive, and magneto-optical disks, and magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data. Additionally, the entire program code, or portions thereof, may be transmitted and downloaded from a software source over a transmission medium, e.g., over the Internet, or from another server, as is well known, or transmitted over any other conventional network connection as is well known (e.g., extranet, VPN, LAN, etc.) using any communication medium and protocols (e.g., TCP/IP, HTTP, HTTPS, Ethernet, etc.) as are well known. It will also be appreciated that computer code for implementing embodiments can be implemented in any programming language that can be executed on a client system and/or server or server system such as, for example, C, C++, HTML, any other markup language, Java™, JavaScript, ActiveX, any other scripting language, such as VBScript, and many other programming languages as are well known may be used. (Java™ is a trademark of Sun Microsystems, Inc.).
[0059] According to one embodiment, each system 716 is configured to provide webpages, forms, applications, data and media content to user (client) systems 712 to support the access by user systems 712 as tenants of system 716 . As such, system 716 provides security mechanisms to keep each tenant's data separate unless the data is shared. If more than one MTS is used, they may be located in close proximity to one another (e.g., in a server farm located in a single building or campus), or they may be distributed at locations remote from one another (e.g., one or more servers located in city A and one or more servers located in city B). As used herein, each MTS could include one or more logically and/or physically connected servers distributed locally or across one or more geographic locations. Additionally, the term “server” is meant to include a computer system, including processing hardware and process space(s), and an associated storage system and database application (e.g., OODBMS or RDBMS) as is well known in the art. It should also be understood that “server system” and “server” are often used interchangeably herein. Similarly, the database object described herein can be implemented as single databases, a distributed database, a collection of distributed databases, a database with redundant online or offline backups or other redundancies, etc., and might include a distributed database or storage network and associated processing intelligence.
[0060] FIG. 8 also illustrates environment 710 . However, in FIG. 8 elements of system 716 and various interconnections in an embodiment are further illustrated. FIG. 8 shows that user system 712 may include processor system 712 A, memory system 71213 , input system 712 C, and output system 712 D. FIG. 8 shows network 714 and system 716 . FIG. 8 also shows that system 716 may include tenant data storage 722 , tenant data 723 , system data storage 724 , system data 725 , User interface (UI) 830 , Application Program interface (API) 832 , PL/SOQL 834 , save routines 836 , application setup mechanism 838 , applications servers 800 1 - 800 N , system process space 802 , tenant process spaces 804 , tenant management process space 810 , tenant storage area 812 , user storage 814 , and application metadata 816 . In other embodiments, environment 710 may not have the same elements as those listed above and/or may have other elements instead of, or in addition to, those listed above.
[0061] User system 712 , network 714 , system 716 , tenant data storage 722 , and system data storage 724 were discussed above in FIG. 7 . Regarding user system 712 , processor system 712 A may be any combination of one or more processors. Memory system 712 B may be any combination of one or more memory devices, short term, and/or long term memory. Input system 712 C may be any combination of input devices, such as one or more keyboards, mice, trackballs, scanners, cameras, and/or interfaces to networks. Output system 712 D may be any combination of output devices, such as one or more monitors, printers, and/or interfaces to networks. As shown by FIG. 8 , system 716 may include a network interface 720 (of FIG. 7 ) implemented as a set of HTTP application servers 800 , an application platform 718 , tenant data storage 722 , and system data storage 724 . Also shown is system process space 802 , including individual tenant process spaces 804 and a tenant management process space 810 . Each application server 800 may be configured to tenant data storage 722 and the tenant data 723 therein, and system data storage 724 and the system data 725 therein to serve requests of user systems 712 . The tenant data 723 might be divided into individual tenant storage areas 812 , which can be either a physical arrangement and/or a logical arrangement of data. Within each tenant storage area 812 , user storage 814 and application metadata 816 might be similarly allocated for each user. For example, a copy of a user's most recently used (MRU) items might be stored to user storage 814 . Similarly, a copy of MRU items for an entire organization that is a tenant might be stored to tenant storage area 812 . A UI 830 provides a user interface and an API 832 provides an application programmer interface to system 716 resident processes to users and/or developers at user systems 712 . The tenant data and the system data may be stored in various databases, such as one or more Oracle™ databases.
[0062] Application platform 718 includes an application setup mechanism 838 that supports application developers' creation and management of applications, which may be saved as metadata into tenant data storage 722 by save routines 836 for execution by subscribers as one or more tenant process spaces 804 managed by tenant management process 810 for example. Invocations to such applications may be coded using PL/SOQL 834 that provides a programming language style interface extension to API 832 . A detailed description of some PL/SOQL language embodiments is discussed in commonly owned co-pending U.S. Provisional Patent Application 60/828,192 entitled, PROGRAMMING LANGUAGE METHOD AND SYSTEM FOR EXTENDING APIS TO EXECUTE IN CONJUNCTION WITH DATABASE APIS, by Craig Weissman, filed Oct. 4, 2006, which is incorporated in its entirety herein for all purposes. Invocations to applications may be detected by one or more system processes, which manages retrieving application metadata 816 for the subscriber making the invocation and executing the metadata as an application in a virtual machine.
[0063] Each application server 800 may be communicably coupled to database systems, e.g., having access to system data 725 and tenant data 723 , via a different network connection. For example, one application server 800 1 might be coupled via the network 714 (e.g., the Internet), another application server 800 N-1 might be coupled via a direct network link, and another application server 800 N might be coupled by yet a different network connection. Transfer Control Protocol and Internet Protocol (TCP/IP) are typical protocols for communicating between application servers 800 and the database system. However, it will be apparent to one skilled in the art that other transport protocols may be used to optimize the system depending on the network interconnect used.
[0064] In certain embodiments, each application server 800 is configured to handle requests for any user associated with any organization that is a tenant. Because it is desirable to be able to add and remove application servers from the server pool at any time for any reason, there is preferably no server affinity for a user and/or organization to a specific application server 800 . In one embodiment, therefore, an interface system implementing a load balancing function (e.g., an F5 Big-IP load balancer) is communicably coupled between the application servers 800 and the user systems 712 to distribute requests to the application servers 800 . In one embodiment, the load balancer uses a least connections algorithm to route user requests to the application servers 800 . Other examples of load balancing algorithms, such as round robin and observed response time, also can be used. For example, in certain embodiments, three consecutive requests from the same user could hit three different application servers 800 , and three requests from different users could hit the same application server 800 . In this manner, system 716 is multi-tenant, wherein system 716 handles storage of, and access to, different objects, data and applications across disparate users and organizations.
[0065] As an example of storage, one tenant might be a company that employs a sales force where each salesperson uses system 716 to manage their sales process. Thus, a user might maintain contact data, leads data, customer follow-up data, performance data, goals and progress data, etc., all applicable to that user's personal sales process (e.g., in tenant data storage 722 ). In an example of a MTS arrangement, since all of the data and the applications to access, view, modify, report, transmit, calculate, etc., can be maintained and accessed by a user system having nothing more than network access, the user can manage his or her sales efforts and cycles from any of many different user systems. For example, if a salesperson is visiting a customer and the customer has Internet access in their lobby, the salesperson can obtain critical updates as to that customer while waiting for the customer to arrive in the lobby.
[0066] While each user's data might be separate from other users' data regardless of the employers of each user, some data might be organization-wide data shared or accessible by a plurality of users or all of the users for a given organization that is a tenant. Thus, there might be some data structures managed by system 716 that are allocated at the tenant level while other data structures might be managed at the user level. Because an MTS might support multiple tenants including possible competitors, the MTS should have security protocols that keep data, applications, and application use separate. Also, because many tenants may opt for access to an MTS rather than maintain their own system, redundancy, up-time, and backup are additional functions that may be implemented in the MTS. In addition to user-specific data and tenant specific data, system 716 might also maintain system level data usable by multiple tenants or other data. Such system level data might include industry reports, news, postings, and the like that are sharable among tenants.
[0067] In certain embodiments, user systems 712 (which may be client systems) communicate with application servers 800 to request and update system-level and tenant-level data from system 716 that may require sending one or more queries to tenant data storage 722 and/or system data storage 724 . System 716 (e.g., an application server 800 in system 716 ) automatically generates one or more SQL statements (e.g., one or more SQL queries) that are designed to access the desired information. System data storage 724 may generate query plans to access the requested data from the database.
[0068] Each database can generally be viewed as a collection of objects, such as a set of logical tables, containing data fitted into predefined categories. A “table” is one representation of a data object, and may be used herein to simplify the conceptual description of objects and custom objects. It should be understood that “table” and “object” may be used interchangeably herein. Each table generally contains one or more data categories logically arranged as columns or fields in a viewable schema. Each row or record of a table contains an instance of data for each category defined by the fields. For example, a CRM database may include a table that describes a customer with fields for basic contact information such as name, address, phone number, fax number, etc. Another table might describe a purchase order, including fields for information such as customer, product, sale price, date, etc. In some multi-tenant database systems, standard entity tables might be provided for use by all tenants. For CRM database applications, such standard entities might include tables for Account, Contact, Lead, and Opportunity data, each containing pre-defined fields. It should be understood that the word “entity” may also be used interchangeably herein with “object” and “table”.
[0069] In some multi-tenant database systems, tenants may be allowed to create and store custom objects, or they may be allowed to customize standard entities or objects, for example by creating custom fields for standard objects, including custom index fields. U.S. patent application Ser. No. 10/817,161, filed Apr. 2, 2004, entitled “Custom Entities and Fields in a Multi-Tenant Database System”, and which is hereby incorporated herein by reference, teaches systems and methods for creating custom objects as well as customizing standard objects in a multi-tenant database system. In certain embodiments, for example, all custom entity data rows are stored in a single multi-tenant physical table, which may contain multiple logical tables per organization. It is transparent to customers that their multiple “tables” are in fact stored in one large table or that their data may be stored in the same table as the data of other customers.
[0070] While one or more implementations have been described by way of example and in terms of the specific embodiments, it is to be understood that one or more implementations are not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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In accordance with embodiments, there are provided mechanisms and methods for resolving a data conflict. These mechanisms and methods for resolving a data conflict can enable an improved user experience, increased efficiency, time savings, etc.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No. 10/891,075, filed Jul. 15, 2004. This application relates to and claims priority from Japanese Patent Application No. 2004-149413, filed on May 19, 2004. The entirety of the contents and subject matter of all of the above is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a disk array device and more specifically to a technique effectively applied to data backup by a battery at the time of a power failure.
[0003] A conventional disk array device, when power supply interruption such as a power failure occurs, retains data in a volatile memory such as a cache memory by a backup battery.
SUMMARY OF THE INVENTION
[0004] However, if the time of power supply interruption exceeds the capacity of a battery, there are risks such as data loss. To avoid these risks, electric power supplied from the battery may be used to write volatile data such as a cache into a nonvolatile memory area (hereinafter “destage”). However, in the case of a so-called short power failure occurring by several tens of seconds, once a process to write data on a cache into a HDD is carried out, part of data is retreated from the cache even if electric power is thereafter recovered. Therefore, response speed becomes slow accordingly.
[0005] A first object of the present invention is to control a data retaining operation of a storage device in an optimized manner depending on the conditions of the power supply interruption. Further, it is to provide such a backup power source that the control of respective portions of a memory device is maintained as normally at the time of the power failure within a predetermined time. By the way, since a process to write data on the cache into a HDD requires large consumption of electric power, it is necessary to employ an external UPS (Uninterruptible Power Supply) or the like. Therefore, restriction to securement and the like of its installation space is unavoidable.
[0006] A second object of the present invention is to incorporate a backup power system into a case body of a storage device, without employing such an external UPS.
[0007] Another object of the present invention is to enhance instantaneous power failure durability to a backup power source in order to maintain operations of the entire device, even in the above-mentioned instantaneous power failure.
[0008] Still another object of the present invention is to provide such a storage device that a backup power source can be maintained in an optimized manner even in a storage case body having many parts to become heat sources, such as a processor on a control board.
[0009] Outlines of representative ones of the inventions disclosed in the present application will be briefly described as follows.
[0010] A disk array device according to the present invention, which has a logic mounting unit and a memory device mounting packaging unit, comprises: a fan for cooling each of said logic mounting unit and said memory device mounting unit; and a case body accommodating each of said logic mounting unit and said memory device mounting unit, wherein said logic mounting unit mounts: a channel controlling unit to which a higher-level device is connected and that performs data transfer control; a disk controlling unit to which a memory device is connected and that performs data transfer control; a cache memory into which data to be transferred between said higher-level device and said memory device is stored temporarily; a shared memory into which control information communicated by said channel controlling unit and said disk controlling unit is stored; and a connecting unit to which said channel controlling unit, said disk controlling unit, said cache memory, and said shared memory are connected, and wherein said memory device mounting unit mounts a plurality of said memory devices, and wherein a battery mounting unit that mounts a nickel hydrogen battery for supplying a backup power source at the time of a power failure is disposed at a lower portion of said case body, and wherein said nickel hydrogen battery in said battery mounting unit disposed at the lower portion of said case body is cooled by natural conviction of air inside said case body by said fan.
[0011] Also, a disk array device according to the present invention, which includes a storage controlling unit with a logic mounting unit and a storage driving unit with a memory device mounting unit, comprises: a fan for cooling each of said logic mounting unit and said memory device mounting unit; and a case body for accommodating said storage controlling unit and a case body accommodating said storage driving unit, wherein said logic mounting unit mounts: a channel controlling unit to which a higher-level device is connected and that performs data transfer control; a disk controlling unit to which a memory device is connected and that performs data transfer control; a cache memory into which data to be transferred between said higher-level device and said memory device is stored temporarily; a shared memory into which control information communicated by said channel controlling unit and said disk controlling unit is stored; and a connecting unit to which said channel controlling unit, said disk controlling unit, said cache memory, and said shared memory are connected, and wherein said memory device mounting unit mounts a plurality of said memory devices, and wherein a battery mounting unit that mounts a nickel hydrogen battery for supplying a backup power source at the time of a power failure is disposed at each lower portion of the case body of said storage controlling unit and the case body of said storage driving unit, and wherein said nickel hydrogen battery in said battery mounting unit, which is disposed at each lower portion of the case body of said storage controlling unit and the case body of said storage driving unit, is cooled by natural conviction of air created inside the case body of said storage controlling unit and the case body of said storage driving unit by said fan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram showing an example of an external structure of a disk array device according to an embodiment of the present invention.
[0013] FIG. 2A is a schematic diagram showing an example of an external structure of a storage controlling unit in a disk array device according to an embodiment of the present invention.
[0014] FIG. 2B is a schematic diagram showing an example of an external structure of a storage controlling unit in a disk array device according to an embodiment of the present invention.
[0015] FIG. 3A is a schematic diagram showing an example of an external structure of a storage driving unit in a disk array device according to an embodiment of the present invention.
[0016] FIG. 3B is a schematic diagram showing an example of an external structure of a storage driving unit in a disk array device according to an embodiment of the present invention.
[0017] FIG. 4A is a schematic diagram showing another example of an external structure of the storage controlling unit in the disk array device according to another embodiment of the present invention.
[0018] FIG. 4B is a schematic diagram showing another example of an external structure of the storage controlling unit in the disk array device according to another embodiment of the present invention.
[0019] FIG. 5 is an explanatory diagram for explaining a cooling operation of the case body in the storage controlling unit shown in FIG. 2 .
[0020] FIG. 6 is a explanatory diagram for explaining a cooling operation of the case body of the storage driving unit shown in FIG. 3 .
[0021] FIG. 7 is a schematic diagram for explaining cooling actions in the case body of the storage controlling unit shown in FIG. 4 .
[0022] FIG. 8 is a schematic diagram showing an example of a circuit structure of a battery box in a disk array device according to an embodiment of the present invention.
[0023] FIG. 9 is a schematic diagram showing an example of the circuit structure of a battery box combined with a capacitor in a disk array device according to an embodiment of the present invention.
[0024] FIG. 10 is a schematic diagram showing an example of each external structure of a battery box and a capacitor box in a disk array device according to an embodiment of the present invention.
[0025] FIG. 11 is a schematic diagram showing an example of an internal structure of a battery box in a disk array device according to an embodiment of the present invention.
[0026] FIG. 12 is a schematic diagram showing an example of an internal structure of a capacitor box in a disk array device according to an embodiment of the present invention.
[0027] FIG. 13A is an explanatory diagram for explaining a connecting condition of a battery output connector in a disk array device according to an embodiment of the present invention.
[0028] FIG. 13B is an explanatory diagram for explaining a connecting condition of a battery output connector in a disk array device according to an embodiment of the present invention.
[0029] FIG. 13C is an explanatory diagram for explaining a connecting condition of a battery output connector in a disk array device according to an embodiment of the present invention.
[0030] FIG. 14 is a wiring diagram showing each wiring condition around a battery box and a capacitor box of a storage controlling unit in a disk array device according to an embodiment of the present invention.
[0031] FIG. 15 is a wiring diagram showing each wiring condition around a battery box and a capacitor box of a storage driving unit in a disk array device according to an embodiment of the present invention.
[0032] FIG. 16 is a flowchart showing a backup controlling operation at the time of a power failure in a disk array device according to an embodiment of the present invention.
[0033] FIG. 17 is a diagram showing a relation between backup time and electric power when a destage operation is performed at the time of a power failure in a disk array device according to an embodiment of the present invention.
[0034] FIG. 18 is a flowchart showing a backup controlling operation at the time of a power failure in a disk array device according to an embodiment of the present invention.
[0035] FIG. 19 is a diagram showing a relation between backup time and electric power when a memory backup operation is performed without performing a destage operation at the time of a power failure in a disk array device according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Hereinafter, embodiments of the present invention will be detailed based on the drawings. Note that the same members are denoted by the same reference symbol in principle throughout all the drawings for explaining the embodiments and the repetitive descriptions thereof will be omitted.
[0037] <Example of External Structure of Disk Array Device>
[0038] In reference to FIGS. 1 to 4 , an example of an external structure of a disk array device according to an embodiment of the present invention will be described below. FIG. 1 is a diagram showing an example of an external structure of the disk array device according to the embodiment of the present invention. FIGS. 2A and 2B are diagrams showing an example of an external structure of a storage controlling unit, wherein FIG. 2A is a drawing viewed from a front direction and FIG. 2B is a drawing viewed from a rear direction. FIGS. 3A and 3B are diagrams showing an example of an external structure of a storage driving unit, wherein FIG. 3A is a drawing viewed from a front direction and FIG. 3B is a drawing viewed from a rear direction. FIGS. 4A and 4B are diagrams showing another example of the external structure of the storage controlling unit, wherein FIG. 4A is a drawing viewed from a front direction and FIG. 4B is a drawing viewed from a rear direction.
[0039] As shown in FIG. 1 , a disk array device according to this embodiment has a structure in which a storage controlling unit 100 and storage driving units 200 are housed in respective case bodies. In the example shown in FIG. 1 , at both sides of a case body for the storage controlling unit 100 , case bodies for the storage driving units 200 are arranged. Further, at lower portions of the respective case bodies of the storage controlling unit 100 and the storage driving units 200 , battery boxes (battery packaging units) 300 , each of which accommodates a nickel hydrogen battery and a charging circuit thereof, etc. for backup at the time of a power failure, are arranged.
[0040] As shown in FIGS. 2A and 2B , the storage controlling unit 100 has a structure in which there are mounted respective logic boards comprising: a channel controlling unit to which a higher-level device is connected and that performs a data transfer control; a disk controlling unit to which a memory device is connected and that performs a data transfer control; a cache memory into which data to be transferred between the higher-level device and the memory device is stored temporarily; a shared memory into which control information communicated by the channel controlling unit and the disk controlling unit is stored; and a switch (connecting unit) to which the channel controlling unit, the disk controlling unit, the cache memory, and the shared memory are connected. In the structure, there are provided with: logic boxes (logic mounting units) 110 performing a data transfer process etc. in the storage controlling unit 100 ; AC power sources 120 inputting and distributing an AC power source; ACDC power sources 130 outputting a DC power source; a console PC 140 and a service processor 150 that control a storage device; a display panel 160 ; and battery boxes 300 .
[0041] In the logic box 110 , a plurality of slots are provided. Into each slot, there are inserted boards equipped with logic boards respectively constituting: the channel controlling unit; the disk controlling unit; the cache memory; the shared memory; and the switch, wherein the respective boards and connectors on a side of the logic box 110 are electrically connected so that various signals are sent and received and power supply is obtained.
[0042] Additionally, in the example shown in FIGS. 2A and 2B , an interior of the storage controlling unit 100 is provided with hard disk boxes (memory device mounting units) 210 in which a plurality of memory devices such as hard disks are accommodated, whereby a minimum unit of a disk array device is configured by the case body of the storage controlling unit 100 .
[0043] Further, on top surfaces of the logic boxes 110 and the hard disk boxes 210 , fans 170 are arranged for dissipating heat generated by the channel controlling unit, the disk controlling unit, the cash memory, the shared memory, the switch, and the hard disks, etc. Additionally, in the ACDC power sources 130 , fans 170 are arranged for dissipating heat generated from circuits in the ACDC power sources 130 .
[0044] The storage driving unit 200 is, as shown in FIG. 3 , provided with a structure of AC power sources 120 , ACDC power sources 130 , hard disk boxes 210 , and battery boxes 300 .
[0045] In addition, on a top surface of the hard disk box 210 disposed at the top stage, fans 170 are arranged for dissipating heat generated from the hard disks etc. Also in the ACDC power sources 130 , fans 170 are arranged for dissipating heat generated from circuits in the ACDC power sources 130 .
[0046] The storage controlling unit 100 is, as shown in FIG. 4 , provided with another structure comprising: logic boxes 110 ; AC power sources 120 ; a service processor 150 ; a display panel 160 ; a power source box 180 on which ACDC power sources are mounted; a monitoring box 190 on which boards monitoring the device environment of the disk array device are mounted; and battery boxes 300 .
[0047] In addition, on top surfaces of the logic boxes 110 , the power source box 180 , and the monitoring box 190 , fans 170 are provided for dissipating heat generated from the channel controlling unit, the disk controlling unit, the cache memory, the shared memory, the switch, the hard disks, respective boards, and the ACDC power sources, etc.
[0048] As shown in FIGS. 1 to 4 , the battery boxes 300 are arranged at the lower portions of the respective case bodies of the storage controlling unit 100 and the storage driving unit 200 , thereby being mounted onto the storage controlling unit 100 and the storage driving unit 200 . However, by using a nickel hydrogen battery as a battery inside the battery box 300 , it is possible to employ a battery having small size and large capacity.
[0049] Accordingly, even in a structure where the battery boxes 300 are mounted on the storage controlling unit 100 and the storage driving unit 200 , the use of the battery boxes 300 mounted on the storage controlling unit 100 and the storage driving unit 200 makes it possible to carry out a process to destage data on the cache memory and the shared memory mounted in the logic boxes 110 , to hard disks etc. in the hard disk boxes 210 , at the time of a power failure.
[0050] <Cooling Operation in Case Body>
[0051] In reference to FIGS. 5 to 7 , a cooling operation in each case body of the disk array device will be explained below. FIG. 5 is an explanatory diagram for explaining a cooling operation of the case body in the storage controlling unit shown in FIG. 2 ; FIG. 6 is an explanatory diagram for explaining a cooling operation of each case body in the storage driving unit shown in FIG. 3 ; and FIG. 7 is an explanatory diagram for explaining a cooling operation of each case body in the storage controlling unit shown in FIG. 4 .
[0052] In this embodiment, there is dissipated heat generated from the fans 170 , which are provided on the top surfaces of the logic boxes 110 , the hard disk boxes 210 , the power source box 180 , and the monitoring box 190 and provided inside the ACDC power source 130 . Therefore, wind (air) paths are formed in the case body of the storage controlling unit 100 and in the case body of the storage driving unit 200 , and the cooling of the battery boxes 300 is performed using natural convection generated by these wind paths in the case body.
[0053] In the storage controlling unit 100 shown in FIG. 2 , as shown in FIG. 5 , by the fans 170 provided on the respective top surfaces of the logic boxes 110 and the hard disk boxes 210 and the fans 170 provided inside the ACDC power sources 130 , wind paths as indicated by arrow marks in FIG. 5 are formed. By natural conviction generated by these wind paths, the battery boxes 300 disposed at the lower portion of the case body are cooled down.
[0054] Also, in the storage driving unit 200 shown in FIG. 3 , as shown in FIG. 6 , by the fans 170 provided on the top surfaces of the hard disk boxes 210 disposed at the top stage and the fans 170 provided inside the ACDC power source 130 , wind paths as indicated by arrow marks in FIG. 6 are formed. By natural conviction generated by these wind paths, the battery box 300 disposed at the lower portion of the case body is cooled down.
[0055] Further, in the storage controlling unit 100 shown in FIG. 4 , as shown in FIG. 7 , by the fans 170 provided on the respective top surfaces of the logic boxes 110 , the power source box 180 , and the monitoring box 190 , wind paths as indicated by arrow marks in FIG. 7 are formed. By natural conviction generated by these wind paths, the battery box 300 disposed at the lower portion of the case body is cooled down. Additionally, in the examples as shown in FIGS. 2, 3 , and 4 , slits are made in a base seat 400 of the battery box 300 to prevent heat from remaining therein.
[0056] As described above, cooling of the battery boxes 300 arranged at the lower portions of the case body of the storage controlling unit 100 and the case body of the storage driving unit 200 are carried out using natural conviction generated by the wind paths in the case bodies. Therefore, it is possible to carry out cooling operations in a range of 15° C. to 25° C., which is ideal temperature for battery life of nickel hydrogen batteries, without cooling in excess or warming in excess the nickel hydrogen battery in the battery box 300 .
[0057] Accordingly, in the case where the nickel hydrogen battery is used as a battery for backup at the time of a power failure, it is possible to expand the battery life to maximum and to secure a guarantee period of a battery as a disk array device.
[0058] <Circuit Structure of Battery Box>
[0059] In reference to FIGS. 8 and 9 , the structure of the battery box will be explained below. FIG. 8 is a diagram showing an example of a circuit structure of a battery box in a disk array device according to an embodiment of the present invention, and FIG. 9 is a diagram showing an example of a circuit structure of a battery box combined with capacitors in a disk array device (hereinafter “capacitor box”) according to an embodiment of the present invention.
[0060] In FIG. 8 , the battery box 300 comprises a nickel hydrogen battery 301 , a charging circuit 302 , a battery monitoring circuit 303 , a reverse flow preventing diode 304 , a switch 305 , a system READY lamp 306 , and a battery charge lamp 307 .
[0061] Also, a DC power supply path 310 to be connected to the ACDC power source and the channel controlling unit and the disk controlling unit, etc., and a memory power supply path 311 to be connected to the cache memory and the shared memory, and a battery box controlling bus 312 for controlling the battery box 300 by microprocessors etc. of the channel controlling unit and the disk controlling unit, are connected to the switch 305 .
[0062] By the DC power supply path 310 , DC power for charging the nickel hydrogen battery 301 is inputted, and the DC power is supplied to the channel controlling unit and the disk controlling unit, etc. at the time of a power failure. By the memory power supply path 311 , the DC power is supplied to the cache memory and the shared memory at the time of the power failure. Also, by the battery box controlling bus 312 , operations of the switch 305 at the power failure are controlled in accordance with instructions from the microprocessors etc. of the channel controlling unit and the disk controlling unit.
[0063] The system READY lamp 306 is controlled by the charging circuit 302 , and indicates, for example, that the battery box 300 is working normally when the lamp is lit and that the battery box 300 is at fault when the lamp is not lit.
[0064] Also, the battery charge lamp 307 is controlled by the charging circuit 302 , and indicates, for example, that the charging of the nickel hydrogen battery 301 in the battery box 300 is completed when the lamp is lit and that the charging of the nickel hydrogen battery 301 in the battery box 300 is now being made when the lamp is not lit.
[0065] The system READY lamp 306 and the battery charge lamp 307 are disposed on the front surface of the battery box 300 so that, by checking the system READY lamp 306 and the battery charge lamp 307 , it is possible for a maintenance worker(s) of the disk array device to easily check the conditions of the battery box 300 .
[0066] In an ordinary case where the AC power source is supplied, the DC power from the ACDC power source etc. is inputted via the DC power supply path 310 , and the nickel hydrogen battery 301 is charged by the charging circuit 302 . Voltage fluctuation etc. of the nickel hydrogen battery 301 are monitored by the battery monitoring circuit 303 , whereby the charging conditions of the nickel hydrogen battery 301 are controlled so that it can be optimized.
[0067] In the case of a power failure etc. of the AC power source, the DC power of the nickel hydrogen battery 301 is supplied, via the reverse flow preventing diode 304 , to the DC power supply path 310 and the memory power supply path 311 , whereby a backup process at the time of a power failure is carried out.
[0068] In FIG. 9 , a capacitor box 320 comprises a nickel hydrogen battery 301 , a charging circuit 302 , a battery monitoring circuit 303 , a reverse flow preventing diode 304 , a switch 305 , a system READY lamp 306 , a battery charge lamp 307 , and a capacitor 321 , and has a structure in which the capacitor 321 is added for supplying, to the battery box 300 shown in FIG. 8 , the DC power at the time of an instantaneous power failure.
[0069] In the capacitor box 320 , in an ordinary case where the AC power source is supplied, the DC power from the ACDC power source etc. is inputted via the DC power supply path 310 , and the nickel hydrogen battery 301 and the capacitor 321 are charged by the charging circuit 302 . The voltage fluctuation etc. of the nickel hydrogen battery 301 are monitored by the battery monitoring circuit 303 , whereby the charging conditions of the nickel hydrogen battery 301 are controlled so that it can be optimized.
[0070] In the case of a power failure etc. of the AC power source, the DC power of the capacitor 321 is supplied, via the reverse flow preventing diode 304 , to the DC power supply path 310 and the memory power supply path 311 by the capacitor 321 during a period of an instantaneous power failure (e.g., 30 ms). As for a DC power source in the case of the power failure for a short time of approximately 30 ms such as an instantaneous power failure, it is possible to easily supply a large amount of DC power by using the capacitor 321 .
[0071] In the case where the power failure continues even after the instantaneous power failure, similarly to the battery box 300 , the DC power of the nickel hydrogen battery 301 is supplied, via the reverse flow preventing diode 304 , to the DC power supply path 310 and the memory power supply path 311 , whereby a backup process at the time of the power failure is carried out.
[0072] <External Structures of Battery Box and Capacitor Box>
[0073] In reference to FIG. 10 , an example of each external structure of a battery box/capacitor box in a disk array device according to an embodiment of the present invention will be explained below. FIG. 10 is a diagram showing an example of each external structure of the battery box and the capacitor box in the disk array-device according to the embodiment of the present invention.
[0074] In FIG. 10 , each of the battery box 300 and the capacitor box 320 is rectangular and is formed so that it can be mounted on the lower portion of the case body of the disk array device.
[0075] Also, on each front surface of the battery box 300 and the capacitor box 320 , a handle 330 , a system READY lamp 306 , a battery charge lamp 307 and a switch 331 are provided. By using the handle 330 , the battery box 300 and the capacitor box 320 may be easily attached and detached. By the system READY lamp 306 and the battery charge lamp 307 , the conditions of the battery box 300 and the capacitor box 320 and the charging conditions of the nickel hydrogen battery 301 and the like may be easily checked by a maintenance worker(s) etc. The switch 331 is a power switch for both of the battery box 300 and the capacitor box 320 .
[0076] Further, on upper surfaces and lower surfaces of the battery box 300 and the capacitor box 320 , slits 332 as shown in FIG. 10 are provided. Therefore, the cooling operations inside the battery box 300 and the capacitor box 320 may be carried out using not the fans 170 etc. but natural conviction by the wind paths as shown in FIGS. 5 to 7 .
[0077] <Internal Structures of Battery Box and Capacitor Box>
[0078] In reference to FIGS. 11 to 13 , an example of each internal structure of the battery box and the capacitor box in the disk array device according to an embodiment of the present invention will be explained below. FIG. 11 is a diagram showing an example of an internal structure of the battery box in the disk array device according to an embodiment of the present invention; FIG. 12 is a diagram showing an example of an internal structure of the capacitor box in the disk array device according to an embodiment of the present invention; and FIGS. 13A to 13 C are explanatory diagrams for explaining a connecting condition of a battery output connector, wherein FIG. 13A is a view showing the neighborhood of a connection of the battery connector and FIG. 13B is a diagram viewed from the direction A in FIG. 13A and FIG. 13C is a diagram viewed from the direction B in FIG. 13A .
[0079] In the battery box 300 , as shown in FIG. 11 , a nickel hydrogen battery 301 is disposed in a front direction of the battery box 300 and, in the rear direction thereof, there is disposed a board of a controlling package 308 comprising a charging circuit 302 , a battery monitoring circuit 303 , a reverse flow prevention diode 304 , and a switch 305 , etc.
[0080] Also, in the capacitor box 320 , as shown in FIG. 12 , the nickel hydrogen battery 301 is disposed in a front direction of the capacitor box 320 and, in the rear direction thereof, there is disposed a board of a controlling package 308 comprising a charging circuit 302 , a battery monitoring circuit 303 , a reverse flow prevention diode 304 , and a switch 305 , etc., wherein a capacitor 321 is disposed between the nickel hydrogen battery 301 and the board of the controlling package 308 .
[0081] As shown in FIGS. 11 and 12 , by disposing the nickel hydrogen batteries 301 in the front directions of the battery box 300 and the capacitor box 320 , the weighty nickel hydrogen batteries 301 can be disposed on sides of the handles 330 before them, whereby the battery box 300 and the capacitor box 320 can be easily attached and detached.
[0082] Further, each of the battery box 300 and the capacitor box 320 can be reduced in size and weight by using the nickel hydrogen battery 301 . Therefore, mounting of the boxes onto the case body of the storage controlling unit 100 and the case body of the storage driving unit 200 is made not by a cable connection but by a board feed's connection in which a battery output connector 340 provided on each rear surface of the battery box 300 and the capacitor box 320 and a connector of a battery platter provided on each mounting portion of the battery box 300 and the capacitor box 320 are connected to each other.
[0083] Carrying out the board feed makes it possible to prevent voltage decline from occurring at the time of the cable connection, whereby the stable backup power source can be carried out.
[0084] Further, the battery output connector 340 is made to be a floating connector, so that it can be moved in 360 degrees, for example, to approximately 5 mm. Therefore, it is possible to improve fitting precision at the time of connecting with a connector disposed on the battery platter side and to carry out the stable connection.
[0085] The battery output connector 340 is, for example as shown in FIGS. 13A and 13B , connected via cables 342 to pins 341 provided on the board of the controlling package 308 . By the cables 342 soldered to the pins 341 , the battery output connector 340 can be moved in 360 degrees, as shown in FIG. 13C , and absorb pressure caused at the time of inserting the battery box 300 and the capacitor box 320 . Accordingly, it is possible to improve the fitting precision at the time of connecting with the connector disposed on the battery platter side.
[0086] <Wiring around Battery Box and Capacitor Box>
[0087] In reference to FIGS. 14 and 15 , wirings around the battery box and the capacitor box in the storage controlling unit of the disk array device according to an embodiment of the present invention will be explained below. FIG. 14 is a wiring diagram showing wirings around the battery box and the capacitor box in the storage controlling unit of the disk array device according to the embodiment of the present invention; and FIG. 15 is a wiring diagram showing wirings around the battery box and the capacitor box in the storage driving unit of the disk array device according to the embodiment of the present invention.
[0088] In the storage controlling unit 100 , as shown in FIG. 14 , the battery box 300 or capacitor box 320 is connected by battery platters 500 , and each battery platter 500 is connected to a power source platter 510 that distributes a DC power source to each load.
[0089] To each power source platter 510 , an ACDC power source 130 to which AC power is supplied from the AC power source 120 is connected, whereby the DC power is supplied at an ordinary time and power for charging the battery box 300 or capacitor box 320 is supplied.
[0090] Further, the battery platter 500 and the power source platter 510 are connected by metallic bus bars 520 , and also signal lines 530 for sending and receiving control signals etc. to and from the battery box 300 or the capacitor box 320 are connected thereto.
[0091] The metallic bus bars 520 and the signal lines 530 are mutually disposed so as not to affect signals in the signal lines 530 .
[0092] Additionally, a logic platter 540 to which a logic boards such as a channel controlling unit, a disk controlling unit, a cache memory, a shared memory, and a switch are connected in the logic box 110 ; the console PC 140 ; the service processor 150 ; the hard disk box 210 ; the fans 170 ; and the like are connected on the load side from the power source platter 510 , whereby the DC power is supplied to each load.
[0093] In the storage driving unit 200 , as shown in FIG. 15 , the battery box 300 or capacitor box 320 is connected by the battery platter 500 . The ACDC power source 130 to which AC power is supplied from the AC power source 120 is connected to the battery platter 500 , whereby the DC power is supplied at an ordinary time and the power for charging the battery box 300 or capacitor box 320 is supplied.
[0094] Also, to the hard disk boxes 210 and the fans 170 on the load side that is connected to the ACDC power source 130 , the DC power is supplied from the ACDC power source 130 at an ordinary time or the DC power from the battery box 300 or capacitor box 320 is supplied via the ACDC power source 130 at the time of a power failure.
[0095] As mentioned above, the battery box 300 and the capacitor box 320 are connected via the battery platter 500 by the board feed. Therefore, it is possible to prevent voltage decline from occurring at the time of the cable connection and to supply the stable backup power source.
[0096] <Backup Controlling Operation at Power Failure>
[0097] In reference to FIGS. 16 to 19 , a backup controlling operation at the time of a power failure of the disk array device according to the embodiment of the present invention will be explained below. FIG. 16 is a flowchart showing the backup controlling operation at the time of a power failure of the disk array device according to the embodiment of the present invention, and shows the case of performing a destage operation at the time of a power failure. FIG. 17 is a diagram showing the relation between backup time and electric power when a destage operation is performed at the time of a power failure. FIG. 18 is a flowchart showing a backup controlling operation at the time of a power failure of a disk array device according to the embodiment of the present invention, and shows the case of performing not a destage operation but a memory backup operation at the time of a power failure. FIG. 19 is a diagram showing the relation between backup time and electric power in the case of performing not a memory backup operation but a destage operation at the time of a power failure.
[0098] Detection of “AC OFF” owing to a power failure is made by the channel controlling unit and the disk controlling unit in the logic box 110 , and detection of a power failure is made by the respective packages (PK) of the channel controlling unit and the disk controlling unit.
[0099] In the case of performing the destage operation at the time of a power failure, as shown in FIG. 16 , whether AC OFF has been detected is determined (S 100 ). If AC OFF is detected in S 100 , an AC OFF detection signal is set to the shared memory in the logic box 110 (S 101 ). By doing so, information of the AC OFF detection by the respective packages of other channel controlling unit and disk controlling unit is shared.
[0100] Then, by confirming the information in the shared memory, whether the packages of the channel controlling unit and the disk controlling unit having firstly detected the AC OFF exist is determined (S 102 ).
[0101] When it is determined that the packages of the channel controlling unit and the disk controlling unit having firstly detected the AC OFF exist in S 102 , the packages secondly detecting the AC OFF are operated. The self-package AC OFF is monitored for one second (S 103 ), and it is determined whether AC has been recovered for 10 seconds or more (S 104 ). If it is determined that the AC has not been recovered for 10 seconds or more in S 104 , the procedure goes back to S 103 . If it is determined that the AC has been recovered for 10 seconds or more in S 104 , the AC OFF detection signal that is set in the shared memory is reset (S 105 ).
[0102] Also, if it is determined that the packages of the channel controlling unit and the disk controlling unit having firstly detected the AC OFF in S 102 do not exist, the packages having firstly detected the AC OFF are operated. The packages having firstly detected the AC OFF monitors the conditions of other packages (S 106 ).
[0103] Then, the self-package AC OFF and the AC OFF detection signal of the shared memory are monitored for one second (S 107 ). It is determined whether the condition where “half number of channel controlling units and disk controlling units”+1 (e.g., 5 packages if the channel controlling units and the disk controlling units have 8 packages) have detected the AC OFF continues for 60 seconds or more (S 108 ).
[0104] If it is determined in S 108 that the condition where the “half number of channel controlling units and disk controlling units”+1 have detected the AC OFF continues for 60 seconds or more, the AC OFF condition is established and the destage or a backup processes such as memory backup is carried out (S 109 ).
[0105] Meanwhile, if it is determined in S 108 that the condition where the half number of channel controlling units and disk controlling units+1 have detected the AC OFF does not continue for 60 seconds or more, whether its own AC has been recovered and whether other packages also have been recovered are determined (S 110 ). If its own AC has been recovered and other packages have not been recovered in S 110 , the procedure goes back to S 107 . If its own AC has been recovered and other packages have also been recovered in S 110 , it is assumed that the AC has been recovered, whereby the procedure goes to a stationary state (S 111 ).
[0106] Also, with respect to the relation between backup time and power at the time when the AC OFF condition is established and a power failure condition gets in is started, as shown in FIG. 17 , a first one minute is a period for establishing the AC OFF condition. During this period, all of the hard disks, channel controlling units, disk controlling units, and cache memory/shared memory are operated.
[0107] After a lapse of one minute, when the AC OFF condition is established, the destage and the structure retreat are carried out. Thereby, the hard disks and the disk controlling units, in which the respective destages have been completed and which become regular disks, are sequentially separated from the power supply, and only one channel controlling unit is left and the other channel controlling units are cut off. The one channel controlling unit is used for structure retreat. Then, when the destage operation is completed, only memory backup of the cache memory and the shared memory is carried out for data guarantee, speeding up at the time of next startup, and memory residence.
[0108] Further, when not a destage operation but a memory backup operation is carried out at the time of a power failure, as shown in FIG. 18 , it is determined whether a power failure has continued for 30 ms or more (S 120 ). If it is determined that the power failure has not continued for 30 ms or more in S 120 , the procedure goes back to S 120 . If it is determined that the power failure has continued for 30 ms or more in S 120 , the memory backup is carried out as not the instantaneous power failure but the power failure (S 121 ).
[0109] Further, the relation between backup time and power in the case of a power failure condition caused due to a power failure longer than an instantaneous power failure is shown in FIG. 19 , wherein during a period of 30 ms for determining an instantaneous power failure, all of the hard disks, channel controlling units, disk controlling units, and cache memory/shared memory are operated.
[0110] At the time of becoming a power failure condition owing to a power failure continuing for 30 ms or more, hard disks and respective packages except the cache memory and the shared memory are cut off and only the memory backup is carried out.
[0111] Even in the case of carrying out a destage operation, if hard disks etc. at a destage destination are not guaranteed or if the destage operation cannot be carried out because a trouble occurs during an instantaneous power failure, the hard disks and the respective packages except the cache memory and the shared memory are cut off and only the memory backup is carried out after a lapse of 30 ms that requires being recognized as an instantaneous power failure or a lapse of one minute that requires establishing the AC OFF condition.
[0112] As mentioned above, in this embodiment, a nickel hydrogen battery 301 is used as a battery utilized for backup at the time of a power failure, thereby becoming compact size and having large capacity. Therefore, the battery having such capacity as to able to carry out the destage process at the time of the power failure can be mount on each lower portion of the case bodies of the storage controlling unit 100 and the storage driving unit 200 , whereby it is possible to realize efficient utilization from the viewpoint of securing an installation place for the disk array device etc.
[0113] Further, the cooling of the battery boxes 300 and the capacitor boxes 320 are performed by the fact that the fans 170 for cooling are not provided on the battery boxes 300 and the capacitor boxes 320 incorporating the nickel hydrogen batteries 301 and that there are used natural conviction created by the wind paths in the case bodies due to the fans 170 for cooling the respective portions of the storage controlling unit 100 and the storage driving unit 200 . Therefore, it is possible to carry out the cooling operation at a temperature range of 15° C. to 25° C., which is optimum as an operation temperature of each nickel hydrogen battery 301 in the battery boxes 300 and the capacitor boxes 320 , and to expand the life of the nickel hydrogen batteries to maximum, and to secure a guarantee period of each battery disposed in the disk array device.
[0114] Still further, since the capacitor boxes 320 are used, the capacitors 321 in the capacitor boxes 320 can supply DC power in the case of a power failure for a short time of approximately 30 ms such as an instantaneous power failure and the like, whereby a stable large amount of DC power can be supplied at the time of an instantaneous power failure.
[0115] Moreover, since the battery box 300 and the capacitor box 320 are connected by use of the battery platter 500 and by the board feed, voltage drop can be restrained and the stable backup power source can be supplied.
[0116] As described above, the invention made by the inventors has been concretely based on the embodiments. However, needless to say, the present invention is not limited to the above-mentioned embodiments and can be variously modified and altered without departing from the gist thereof.
[0117] Effects obtained by the representative ones of the inventions disclosed by this application will be briefly described as follows.
[0118] According to the present invention, by the batteries mounted in the case bodies of the disk array device, it is possible to carry out a battery backup operation including a destage process of data and further to increase instantaneous power failure durability to an instantaneous power failure.
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A disk array device connected to a higher-level device, including: a battery mounting unit which mounts a nickel hydrogen battery, charges a part of electric power supplied to said logic mounting unit and said memory device mounting unit, and supplies said charged electric power to said logic mounting unit and said memory device mounting unit at the time of a power failure, wherein said logic mounting unit mounts a cache memory which temporarily stores data transferred from said high-level device and performs control to write the data stored in said cache memory to said plurality of memory devices at the time of power failure, and the power supply from said batter mounting unit to said plurality of memory devices is sequentially stopped in the order of the memory device to which data writing from said cache memory has been completed at the time of the power failure.
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RELATED APPLICATIONS
[0001] The present application is a continuation-in-part application of U.S. provisional patent application Ser. No. 60/938,512; filed 17 May 2007, included by reference herein and for which benefit of the priority date is hereby claimed.
FIELD OF THE INVENTION
[0002] The present invention relates to static structures used in the construction arts. In particular a header partition support for use with joists, trusses, windows and doors which is; modularized, insulated and allows ease of construction and attachment surfaces.
BACKGROUND OF THE INVENTION
[0003] In construction, it is important to bear high structural loads in order to support a building or other similar structure. Typically this has been done by providing a structure framed with 2×4 inch or 2×6 inch etc. cross-sectional studs provided with a regular spacing to support the weight. When a window or door is desired in the structure, that spacing is disrupted and the stresses can become concentrated to the point where the integrity of the larger structure is compromised. In an attempt to address this issue, a lateral support member, commonly called a header, is placed above the opening to bear the weight otherwise carried by the studs, and transfer the load to the outer perimeter of the opening allowing the opening to bear the load.
[0004] Further when a mid-span support is required for a floor intersection, a beam or header structure can be used to support the trusses or joists. Many times this is support structure is realized by resting the joists or trusses on the beam creating a separate level of structure, which can be unsightly as seen from the floor below.
[0005] Prior art for constructing window and door headers can be as simple as two lateral beams, typically 2×8 to 2×12 inches in cross-section, nailed together with a piece of plywood sandwiched in between, to set the proper spacing, and placed laterally above the opening to transfer the load to a pair of king studs located vertically at the perimeter of the opening. This solution typically does not have good insulation value and the beam and plywood members can twist and warp and deflect due to load.
[0006] In additional alternative a glued laminated timber, or glulam can be used to replace the solid beam. This provides a nailing surface for hanging sheetrock, or other facing, and some structural support but has been plagued by structural fatigue due to delamination over time, and the structural limits of wood's load bearing capacity.
[0007] Recently, steel “I” beams have been used, which are superior to wood for load bearing capability, but one problem being no sufficient structure for nailing or otherwise attaching other items to the beam. Due to the incompatibility of steel beams for attaching, the structure to be supported is rested on top of the beam, which creates architectural challenges as mentioned above. Another issue being the very poor insulation quality of steel without other means for mitigation.
SUMMARY OF THE INVENTION
[0008] The current invention, comprises an enclosed structure to provide a pre-formed modularized insulated beam for forming lintel or header structures. This apparatus and methodology, when combined with a structural metal beam such as an “I” beam, complements and even strengthens the load bearing capacity of the beam. Those skilled in the art can appreciate that an “I” beam can comprise an S beam (standard beam) and a W beam (wide flanged beam). The apparatus can further provide a suitable attachment surface during subsequent construction operations such as nailing, screwing, gluing and the like. In addition to provide adequate insulation value for the metal beam, which is normally a poor thermal insulator, which is extremely important in colder climates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
[0010] FIG. 1 depicts a perspective view of a structural header;
[0011] FIG. 2 depicts a side plan view of a structural header;
[0012] FIG. 3 an exploded view of a structural header;
[0013] FIGS. 4A through 4F depict partial side plan views detailing structural considerations for alternate embodiments of a structural header;
[0014] FIG. 5 depicts a perspective view of a structural framing for a window using a header of the present invention;
[0015] FIG. 6 depicts a top perspective view of a header in construction with joists and nailers;
[0016] FIG. 7 depicts a perspective view of a header in construction with trusses forming a floor above an opening for large panel doors and the like;
[0017] FIG. 8 depicts a perspective view of an arch structure with load bearing capabilities which incorporates the header;
[0018] FIG. 9A depicts a side plan view of an alternate embodiment of a structural header;
[0019] FIG. 9B depicts an exploded view of an alternate embodiment of a structural header.
[0020] FIG. 9C depicts a side plan view of a structural header with a joist hanger and joist attached to the face.
REFERENCE NUMERALS IN DRAWINGS
[0000]
10 —structural header
10 a —box beam
11 —web portion
12 —beam
13 —flange portion
14 —insulation space
15 —injection point
16 —horizontal member
16 a —horizontal double member
17 —frame
18 —vertical member
18 a —alternate vertical member
19 —cleat
20 —nailer
22 —fastener
30 —sill plate
32 —top plate
34 —stud
35 —cripple
36 —king stud
40 —joist hanger
42 —joist
44 —truss members
46 —modular arch unit
A—vertical vector component
B—horizontal vector component
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] The structural header as shown in FIGS. 1 , 2 A, 2 B, and 3 ; consisting primarily of a beam 10 , one embodiment of which FIG. 2A is an example, comprising a pre-manufactured box beam 10 a comprising a pair of horizontal members 16 connected with a pair of vertical members 18 with an insulation space 14 generally comprised of structural foam.
[0048] In another embodiment shown in FIG. 2B an element known in the trade as an “I” beam is added to the system. The beam 12 , which is typically made of a metal such as steel, and is comprised of a web portion 11 which is a vertical member for load bearing, being nominally 8 to 12 inched in height, and two flange portions 13 located on the top and bottom of the web portion 11 , being nominally 4 inches in width, for lateral stability. While the beam 12 is typically quite strong compared with wooden framing for construction purposes, it does not provide good nailing or attaching surfaces typically required in conjunction with wooden framing. Additionally it is a poor insulator. To help utilize the “I” beam 12 for general construction purposes, a box is created around the beam 12 in such a way as to strengthen it from twisting and torquing, by adding a structural horizontal member 16 which is typically glued or otherwise affixed to the flange portions 13 of the beam. The horizontal member 16 is preferred to extend beyond the flange portions 13 sufficient to provide a fastening surface for the vertical members 18 . The vertical members 18 can be affixed to the horizontal framing members through fasteners 22 which can be any combination of screws, nails, glue, tape, staples, or the like. With a preferred embodiment being screws, such as drywall screws generally of 1½ to 2½ inches in length. In addition the framing members can be wood, oriented strand board (osb), plywood, hardboard, or other suitable material of suitable thickness with ¾ inch being most common.
[0049] To further enhance the properties of the structural header 10 , an insulation space 14 is provided for supplying insulation. This insulation space 14 can be filled with any combination of; rock wool, fiberglass, Styrofoam, or polyurethane foam, or their equivalents. With the preferred method being an open cell, low density, non-ozone depleting polyurethane foam which is not subject to deterioration from moisture. The foam can be added through injection points 15 provided along the vertical member 18 in the region of the insulation space 14 and further expands to fill the insulation space 14 with the advantage of further securing, by adhering to or gluing, the beam 12 and the frame 17 . To keep a polyurethane foam from expanding out the lateral opening of the insulation space, a form or board can be temporarily affixed to the ends of the structural header 10 until the foam sets up.
[0050] Lateral support for fastening to a structure is added by including a nailer 20 , shown in FIGS. 1 and 3 to connect the end of the structural header and tie into the studs. The nailer 20 is typically a plate or joist nailer which may be folded back until needed in construction.
[0051] Several functional alternate embodiments for construction of the structural header are shown in FIGS. 4A through 4F . These Figures show approximately the top half of a partial side plan view of a structural header similar to that shown in FIG. 2 as the structure will typically comprise a top to bottom symmetry. While those skilled in the art may be able to devise alternate structures for enclosing the beam 12 , it is claimed that these are within the scope of this invention.
[0052] As the insulation space 14 is filled with expanding foam insulation, forces are created inside the insulation space 14 which can be represented by a vertical vector component A and a horizontal vector component B. FIG. 4A shows a construction where the horizontal member 16 forms a butt joint with the vertical member 18 . In this case the horizontal vector component B has only the fastener 22 , which is fastened into the horizontal member 16 to act against the horizontal vector component B. This may result in the fastener 22 pulling out resulting in separation between the vertical member 18 and the beam resulting in insulation foam expanding out of the insulation space 14 and further structural weakening of the structural header 10 . Therefore, while possible to implement, this mode is not preferred to one with a mode which secures the joint against expansion.
[0053] FIGS. 4B through 4F show several alternate modes which overcome disadvantages seen in embodiment of 4 A. These embodiments derive from the property of the flange portion 13 of the beam 12 to deflect the forces, particularly the vertical vector component A, created by the expansion of foam insulation. In particular the vertical vector component A. FIG. 4B shows an embodiment in which the vertical member 18 is butt jointed to the horizontal member 16 requiring the fastener 22 to be sheared before separation could occur through action by the horizontal vector component B. FIGS. 4C through 4E show alternate modes for providing enclosures for the structural header to include: dados, rabbets, lock joints, spline joints, tongue and groove, mortise and tenon and the like. FIG. 4F shows a preferred mode of providing a horizontal double nailer 16 a being generally 1½ inch thick having a rabbet for providing double nailing and attachment surfaces.
[0054] Examples of the structural header 10 for use in the construction arts are shown in FIGS. 5 , 6 , 7 and 8 . The structural header 10 can be used in framing above windows, doors, garage door openings and the like. It is used to deflect the load in a bearing wall, generally through a top plate 32 which comes from a roof, other floors of the structure, and the like; and to transfer the load to the foundation through the sill plate 30 . These loads would typically be borne by studs 34 in a continuous wall. This load transfer is typically done by deflecting the load along the structural header 10 to a structural support such as a king stud 36 which directly bears the load.
[0055] In some instances, a simple header of “two by” construction may be sufficient to deflect the load. But increasingly with architectural demands, the structural header, or lentil, of prior art is inadequate to support the span. Large spans, such as garage door openings, plate windows or large door frames, decks, arched entries, extra floors, all having large expansive openings require additional reinforcement. One example of the utility of the current invention can be seen by considering the structure exemplified in FIG. 6 . In the prior art (not shown), a structure similar to that shown in FIG. 6 would have been accomplished by running a steel beam under the joists 42 as a steel beam cannot be nailed into to secure wooden structures. A steel beam under the joists causes unsightly seams and depressions as seen from the floor below. Further carpenters expend considerable work to try and blend in a beam for architectural reasons. The structural header 10 of the current invention provides both the structural support of a beam 12 with the ability to attach joists 42 at the floor level with a standard joist hanger 40 , while providing insulation space 14 . In another example shown in FIG. 7 , a structural header 1 0 is used to tie into and support that load from truss members 44 above a large opening where the load is deflected to king studs 36 for the area below the opening. The king stud 36 for the purposes of this disclosure may be made of wood, metal, or other suitable load bearing material. The ability to provide structural support having an architecturally pleasing structure, with surfaces for nailing, insulation and other advantages is provided.
[0056] In yet another example shown in FIG. 8 , a modular arch unit 46 is created having a horizontal double member 16 a with a beam 12 wherein an alternate vertical member 18 a replaces the vertical member 18 (not shown) such that an architecturally pleasing arch is created requiring little skill on the part of construction workers to add it to an existing framing structure, as those with skill in the art can appreciate.
[0057] FIGS. 9A and 9B represent an alternate embodiment to the structural header 10 comprising a cleat 19 , thus forming an alternate vertical member 18 a . The cleat 19 can be any, cleat, shelf, projection, ledge, sill, step, ridge or other solid structural rigid overhang or member designed to reinforce a vertical member 18 (not shown) providing strength or hold in position. The cleat 19 can also be integrally formed along the entire elongated edge as part of the vertical member 18 as shown in FIGS. 9A and 9B . The cleat 19 can be advantageous in cases where a joist hanger is nailed to the side of the alternate vertical member 18 a , as shown in FIG. 9C . The cleat 19 utilizes the flanges 13 of the beam 12 to further support the alternate vertical member 18 a.
Conclusion, Ramifications, and Scope
[0058] Although the present invention has been described in detail, those skilled in the art will understand that various changes, substitutions, and alterations herein may be made without departing from the spirit and scope of the invention in its broadest form. The invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0059] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequent appended claims.
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The present invention relates to the construction arts, in particular a new implementation for a structural support member or header for bearing the load of large spans of a floor, wall section above a window, door or garage door. The support member has an insulation which, when used with a steel beam, serves to increase the insulation value. Further the header is modular and can be easily implemented into a variety of architectural structures.
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BRIEF DESCRIPTION OF THE INVENTION
This invention provides an accumulator which has no sensor of the conventional type. The shift from conveying to accumulation mode and the return from accumulation to conveying mode is controlled by a sensing belt. The belt does not sense the presence of an article but rather it senses the fact that the article supporting and conveying rollers are held against rotation by a stalled article.
The invention employs belt support units, several of which form an operating group with the groups arranged in tandem along the length of the conveyor. Under normal conveying circumstances, all of the operating groups will be functioning in conveying mode with the result that articles will continuously move along the conveyor. However, should an article become stalled, this will result in the rollers beneath that article being frictionally held against rotation. This will be sensed by a sensing belt which itself becomes stalled and transmits this fact to the upstream support unit of the next upstream operating group. This upstream support unit is interconnected by a belt drive means to all of the support units except one in the next upstream operating group. The one it is not connected to is the last upstream support unit which corresponds in that group to the one connected to the stalled sensing belt. The stalling of the sensing belt will result in release of the driving connection between the primary propelling member or driving belt above all of the support units interconnected to it. This termination of the drive to the adjacent support units of the next upstream group will cause the articles entering the zone controlled by that upstream group to lose conveying power and become stationary behind the first article. This pattern of operation repeats progressively upstream of the conveyor as more and more articles are accumulated on the conveyor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, plan view of an accumulation conveyor equipped with this invention with only a fragmentary showing of the belt and the conveying rollers omitted for clarity; and
FIG. 2 is a partially sectional, side elevational view of the conveyor illustrated in FIG. 1; and
FIG. 3 in an enlarged, fragmentary view of a portion of a conveyor equipped with this invention; and
FIG. 4 is a sectional, elevational view taken along the plane IV--IV of FIG. 1; and
FIG. 5 is a sectional elevational view taken along the plane V--V of FIG. 1; and
FIG. 6 is a sectional, elevational view taken along the plane VI--VI of FIG. 1; and
FIG. 7 is an elevational view of the sensor belt pulley and outer belt support wheel shown at the right hand end of FIG. 5; and
FIG. 8 is an end view of the outer end of the wheel shown in FIG. 7; and
FIG. 9 is an end view of the inner end of the wheel shown in FIG. 7; and
FIG. 10 is an elevational view of the inner wheel couple of a support unit; and
FIG. 11 is an end view of the right hand end of the wheel couple shown in FIG. 10; and
FIG. 12 is an end view of the left hand end of the wheel couple shown in FIG. 10; and
FIG. 13 is an elevational view of the outer wheel at the left hand end of the support unit as illustrated in FIG. 5; and
FIG. 14 is an end view of the inner end of the wheel shown in FIG. 13; and
FIG. 15 is an elevational view of the outer wheel at the right hand end of the support unit illustrated in FIGS. 4 and 6; and
FIG. 16 is an end view of the inner end of the wheel shown in FIG. 15; and
FIG. 17 is an enlarged, sectional view taken along the plane XVII--XVII of FIG. 10; and
FIG. 18 is a schematic view illustrating the operation of the invention; and
FIG. 19 is a schematic view illustrating the invention applied to a wheel conveyor; and
FIG. 20 is a sectional elevational view taken along the plane XX--XX of FIG. 19.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As herein used, the terms "upstream" and "downstream" are used in relation to the direction of movement of the articles along the conveyor. This is opposite to the direction of movement of the drive belt in a powered roller conveyor and in the same direction as the belt in a wheel conveyor.
A powered roller, accumulator conveyor is disclosed in which the article propelling rollers are driven from beneath by a belt. This is the primary driving belt. The primary belt is supported at spaced intervals by support units each having four wheels arranged on a common shaft. The wheels of the support unit provide vertical position control for the primary driving belt.
A portion of the circumferential surface of all four wheels has a reduced radius to provide a rest or flattened area. The support units are arranged in operating groups arranged in tandem along the accumulator. Associated with the groups are operating zones each of which overlaps two adjacent zones. Each operating group has a sensing belt along one side of and parallel to the powered propelling belt. The sensing belt also extends upstream to make driving connection with the downstream support unit of the next upstream operating group. The sensing belt is permanently held in driven contact with the article propelling rollers above it. This belt is connected to only the last upstream support unit of the operating group with which it is associated. This connection is a lost motion, rotary connection. The sensing belt is, however, in contact with the conveyor rollers above its associated operating group.
The four wheels of each support unit consist of an inner couple or pair integrally connected and a pair of outer single wheels. Each outer single wheel is connected to the inner wheel couple by a lost motion clutch. This allows the outer wheels to arrange their flat surfaces in an out-of-phase relationship to each other and to the flat surfaces of the wheels of the inner couple when the conveyor is in conveying mode and to rearrange themselves into an in-phase relationship, with their flat surfaces up, when in accumulation mode. All but the upstream one of the inner wheel couples of each operating group are interconnected for simultaneous operation. These are also connected to the inner wheel couple of the last upstream support unit of the next downstream operating group. The interconnection of these inner wheel couples is made by secondary drive belts. The support units subtended by a sensing belt constitute an operating group which the support units operatively interconnected by secondary drive constitute an operating zone.
Cessation of movement of an article above one group stops rotation of the article supporting conveyor rollers, thus terminating power to the sensing belt contacting these rollers. Since this terminates drive to the upstream one of the support units of the operating group beneath, it also results in termination of drive to the drive belt connected to the downstream support units of the next upstream operating group. This causes the wheels of the support units of the upstream group to become stationary with their flattened areas up, dropping the belt into non-drive or accumulation position with respect to the conveyor rollers above.
Now referring to FIG. 1, the numeral 10 refers to a conveyor having a pair of spaced side frame members 11 joined at suitable intervals by cross members 12. Extending lengthwise of the conveyor are a pair of laterally spaced, L-shaped stringers 13 forming a central medial lane along the conveyor. While this lane is illustrated as centered in the conveyor, this is not essential. The stringers 13 are supported on the cross members 12. Their vertical position can be adjusted by suitable means such as the threaded studs 14 (FIG. 5).
At uniformly spaced intervals, support units are mounted between the stringers 13. These support units are of three types, designated as 20, 20a and 20b. Each support unit has an axle 21 which, between the stringers 13, mounts a central, inner wheel couple 22. This structure is the same for all three types of support units 20, 20a and 20b.
The wheel pair 22, as best seen in FIGS. 10 and 17, consists of a pair of wheels 23 and 24 which are spaced apart to form a central channel 25. The central channel 25 is divided into a pair of sprocket pulleys 26 and 26a, separated from each other by a radially extending flange 27. The purpose of this construction will be explained subsequently.
The outer face of the wheel 24 is recessed at 28, as is indicated in FIG. 11. Concentric within the recess 28 is an axially extending annular wall 29 from one portion of which an axially extending clutch finger 30 projects substantially beyond the outer face of the wheel. The clutch finger 30 is a semicircular shell subtending an arc of 180°.
The construction of the wheel 23 is quite similar to that of the wheel 24 and has a recess 31 in its outer face equipped with an inner annular wall 32 from which a clutch finger 33 projects axially substantially beyond the outer face of the wheel. Again, the clutch finger 33 is a circular shell subtending 90° of arc. It will be observed from FIGS. 11 and 12 that the clutch fingers 30 and 33 are radially offset outwardly from the radial outer face of the walls 29 and 32. The walls 29 and 32 form the hubs for the inner wheel couple. This creates a circumferential passage 34 in the case of the wheel 24 and a circumferential passage 35 in the case of the wheel 23. It will be observed from FIG. 10 that the axial length of the outer peripheral shell of the wheel and that of the inner walls or hubs in the case of both the wheels 23 and 24, are in the same plane.
The downstream support unit 20 (FIG. 4) of each operating group, in addition, has a pair of end wheels 40 and 41 at opposite ends of the inner wheel couple 22. The inner wheel couple 22 and the two outer wheels 40 and 41 are all freely rotatable on the shaft 21.
The inner face of the outer wheel 41 has an axially projecting annular central hub 42 of the same diameter as the hub 29 of the wheel 24 (FIG. 16). Between the inner hub wall 42 and the peripheral wall 43 is a circular channel 44 which receives the clutch finger 30. The channel 44 subtends 270° of arc and has a stop 45 at each end to limit the relative rotational movement between the outer wheel 41 and the inner wheel couple 22. The combination of the channel 44 and the clutch finger 30 provides a lost motion connection or a clutch with limited rotational slippage.
The second outer wheel 40 also has a channel 46 subtending an arc of 270° for receiving the clutch finger 33 (FIGS. 13 and 14). This channel is between the inner hub 47 and the outer peripheral wall 48 of the wheel. The opposite ends of the channel have radially extending webs forming stops 49. The combination of the channel 46 and the finger 33 provides a lost motion connection or a clutch having limited rotational slippage.
Adjacent the outer wheel 41, an idler pulley 50 is mounted for free rotation about the shaft 21. The idler pulley is of substantially smaller diameter than the wheels 23, 24, 40 and 41.
The end wheels 40 and 41, the inner wheel couple 22 and the idler pulley 50 preferably are all mounted on the shaft by suitable bearings such as ball bearings press fitted into their hubs.
The intermediate support unit 20a is illustrated in FIG. 6. That part of its structure which is identical to the downstream support unit 20 has the same identifying numbers. Thus, it has a shaft 21, an inner wheel couple 22 and end wheels 40 and 41. However, the idler pulley 50 is replaced by a tubular sleeve 55 which serves as a spacer to maintain the position of the wheels.
The upstream support unit 20b is illustrated in FIG. 5. That part of its structure which is identical to the downstream support unit 20 has the same identifying numbers. Thus, it has a shaft 21, an inner coupler 22 and an end wheel 40. However, the other end wheel 41 is replaced with a coupling member 60.
The inner end of the coupling member is formed into a wheel portion 61 identical in construction to the outer wheel 41 illustrated in FIG. 16. The inner face of the wheel portion 61 of the coupling member 60 has an axially projecting, ring-like central hub 62 of the same diameter as the ring-like hub 29 of the wheel 24 (FIG. 9). Between the inner hub wall 62 and the outer peripheral wall 63 is a circular channel 64 which receives the clutch finger 30. The channel 64 subtends 270° of arc and has a stop 65 at each end to limit the relative rotational movement between the coupling member 60 and the inner wheel pair 22. This arrangement provides a lost motion connection or clutch with limited rotational slippage.
Spaced outwardly from the wheel portion 61, the coupling member 60 has a belt pulley 66 which, as shown in FIG. 7, is recessed slightly on its periphery to receive the sensing belt hereinafter described. The diameter of the belt pulley 66 is somewhat greater than that of the wheel portion 61 of the coupling member.
Each of the wheels 23, 24, 40 and 41 and the wheel portion 61 has a rest or flattened portion 70 on its periphery. This is formed by a segment of reduced radius. In the case of the wheels 23 and 24 of the inner wheel couple 22, the rest or flattened portions 70 are aligned with each other axially of the unit whereby they are in the identical circumferential position. However, in the case of the wheel 24, the rest 70 is diametrically opposite from and centered about the clutch finger 30 (FIG. 11). In the case of the wheel 23, the rest 70 is adjacent to and centered about one end of the clutch finger 33 (FIG. 12). In the case of both of the outer wheels 40 and 41 and of the wheel portion 61, the rest portions 70 are centered about one of the stops. This arrangement permits the flattened portions 70 of the outer wheels to be out-of-phase, that is, shifted circumferentially at least 90° from the rest 70 of the inner wheels. However, when either the coupling member 60 or the inner wheel couple is held against rotation, the result will be to bring the rests 70 of all of the wheels into phase, thus, aligning them to form a continuous plane across all four wheels of the support unit. The principles of this type of eccentric belt support for an accumulator are disclosed in U.S. Pat. No. 3,854,576 entitled "Eccentric Wheel Accumulators" issued Dec. 17, 1974.
The support units 20, 20a and 20b are arranged in operating groups. The number of support units in each group is dependent upon the length or size of the articles to be accumulated. The longer the articles, the more support units provided in each operating group since the number of support units in each group determines the length of the zone of operation of the accumulator. The minimum number of support units comprising an operating group is three. For purposes of illustration, each operating group consists of four support units. In each operating group as thus disclosed, there is a downstream support unit 20 (FIG. 4), a pair of intermediate support units 20a (FIG. 6) and an upstream support unit 20b (FIG. 5).
As is best seen in FIGS. 3 and 18, each operating group has a sensing belt 80. The downstream end of the sensing belt 80 passes over the idler pulley 50 of the downstream support unit 20. Because the idler pulley 50 is of reduced diameter, the sensor belt 80 makes no contact with the conveyor roller 81 which is immediately upstream of the support unit 20. The sensing belt passes over and drives pulley 66 of the upstream support unit 20b. By virtue of the guide pulleys 82, upstream of the support unit 20 and between the intermediate support units 20a, the sensing belt 80 is held in contact with the conveyor rollers 81 above the two intermediate support units 20a (FIGS. 3 and 6).
In addition to the sensing belt 80, each group also has a plurality of secondary driving belts 83. Each secondary belt 83 provides driving interconnection between a pair of the inner wheel couples 22 of two adjacent support units. The secondary belts 83 are trained over the sprocket pulleys 26 and 26a at the center of the wheel couples 22. One secondary belt, for example, will interconnect the inner wheel couple of support unit 20 and the inner wheel couple of the adjacent intermediate support unit 20a. This belt is seated in the adjacent pulley sprocket to that for the belt interconnecting the intermediate support units 20a. In this manner, four of the support units are positively interconnected for simultaneous operation. The secondary drive belts 83 interconnect support unit 20b of the preceding downstream operating group with the downstream support unit 20 and the two intermediate support units 20a of the next upstream operating group. These belts tie these units together for simultaneous operation.
The four support units interconnected by the secondary drive belts form an operating zone. It will be observed from FIG. 18 that an operating zone overlaps portions of two operating groups. The difference between the two is that the operating group controls the sensing to which the next upstream operating zone responds. The operating zone is the area of accumulation because it is the area in which the conveyor rollers 81 are released from the primary drive belt 84.
Referring to FIGS. 3 and 18, for the purpose of this explanation it is assumed that all wheels of the support units 20 and 20a of group 1 have been caused to assume an accumulation mode, interrupting drive between the primary belt 84 and the conveyor rollers 81 above these units. Assuming the primary drive belt 84 is moving in the direction of the arrow A, and thus the articles are moving in the direction of the arrow B, an article entering group 1 will become stalled above the downstream support unit 20 and intermediate support units 20a of group 1. The presence of the article will stall the conveyor rollers 81 on which it rests.
Prior to the article becoming stalled, the rollers 81 above the support units 20a, while disengaged from the primary conveyor belt 84 were free to rotate and, therefore, imposed no braking effect upon the sensing belt 80. The stalled rollers will render the group 1 sensing belt 80 stationary and hold it stationary. This, in turn, will stall the wheels of the downstream and intermediate support units of the upstream operating group 2 causing the wheels of all four of the secondary belt interconnected supporting units, including the three in group 2, to adjust to accumulation mode. The driving connection between the primary belt 84 and the conveyor rollers 81 above these supporting units will be interrupted. However, so long as no article is resting on these conveyor rollers, they are free to turn and, therefore, will not impose any restraint upon the continued movement of the sensing belt 80 of group 2. The sensing belt 80 of group 2 will continue to operate, driven by the support unit 20b of group 2 and by the support units 20 and 20a of group 3 because of the interconnection created by the secondary belts 83.
When the next article enters operating zone 1 it will continue to be conveyed until it contacts and is stalled by the article in the upstream zone ahead, above the intermediate support units of group 1. Its movement to this point is assured because the conveyor rollers 81 in operating zone 1 will continue to be driven by the sensing belt 80 of group 2 with power derived from operating group 3. However, as soon as the article becomes stalled in operating zone 1, this will stall sensing belt 80 of group 2 and initiate the shift of the support units in operating zone 2 to accumulation mode. This process will continue to be repeated upstream as more articles continue to be accumulated.
When the support units shift to accumulation mode, the primary belt 84 drops because the rests 70 of all the wheels become aligned, facing upwardly. When the sensing belt of group 1 stalls, the couple 23 of support unit 20b will continue to turn under the drive of the primary belt 84 until the rest 70 of the wheel portion 61 is uppermost. It will then stall due to lack of driving contact with the primary belt 84 and the braking effect of the sensing belt 80. The inner wheel couple 22 will continue to rotate due to contact with the primary belt 84 until the rests 70 of the wheels 23 and 24 have shifted to the top. At this point, not only will contact with the primary belt 84 be greatly reduced or eliminated, the clutch finger 34 will contact one of the stops 65. This will apply the braking effect of the sensing belt to the inner wheel couple. The remaining outer wheel 40 will continue to turn until its rest 70 is uppermost, at which point, the clutch finger 33 will engage one of the stops 49. In this manner the rests 70 of all of the wheels of the support unit will be aligned and under the braking control of the stalled sensing belt.
It is important when the supporting units are installed that all of the inner wheel couples 22 which are connected by secondary belts 80 as an operating unit have their rests 70 located in the same circumferential position. When the inner wheel couple 22 of the upstream support unit of a group stalls in accumulation mode, the inner wheel couples 22 of the interconnected support units also stall in exactly the same circumferential position. Because this is necessary and no slippage or creep can be tolerated, the secondary belts 83 have teeth which engage the teeth 88 of the sprockets 26 and 26a (FIGS. 10 and 17).
When the block is removed permitting the lead downstream article to resume movement, assuming at least one conveyor roller beneath the article has remained under power or some other means is provided which initiates article movement, the initial movement of the article will reestablish rotation of the conveyor rollers on which it is resting. This will activate the sensing belt 80 of group 1. A very small movement of the sensing belt 80 will result in rotating the inner wheel couple of support unit 20b of group 1 and the inner wheel couples of support units 20 and 20a of group 2 into driving contact with the primary belt 84. As soon as this occurs, full conveying effect will be restored to operating zone 1. This will activate the sensing belt 80 of group 2 which will, in the same manner, initiate restoration of conveying mode in operating zone 3. This process will be repeated upstream until conveying mode is once more restored to the entire accumulator.
In returning the support units to conveying mode, the lost motion clutches between the inner wheel couples and the outer wheels permit the inner wheel couples to shift out-of-phase with the outer wheels before the outer wheels start rotating. This restores the support units to forming circular support surface to the primary belt 84.
The outer wheels 40 and 41, the inner wheel couple 25 and the coupling member 60 are all preferably molded from a suitable plastic material such as Delrin, an acetal resin manufactured by E. I. du Pont de Nemoirs & Co. The use of this material provides parts which do not require lubrication and operate at a very reduced noise level.
FIGS. 19 and 20 illustrate this invention applied to a wheel conveyor as contrasted to its application to a powered roller conveyor. In the following description those components which are identical to the structure illustrated in FIGS. 1 through 18 are identified by the same number. In this type of conveyor, the powered belt 84a is preferably located in a median and generally centered between the side frame members 11 of the conveyor. When the belt is raised into conveying mode, its top surface is co-planar with or slightly above the article supporting surface of the rollers 100 which flank it on each side. When the belt 84a is shifted to accumulation mode, it is lowered beneath this plane sufficiently to disengage articles seated on the rollers 100.
The arrangement of the mechanism for accomplishing the mode shift is quite similar to that illustrated in FIG. 18 with the several support units 20, 20a and 20b being arranged in the same relationship with respect to the direction of movement of the articles. However, they are reversed with respect to the direction of movement of the belt 84a. This becomes clear by comparing FIGS. 18 and 19 in which the direction of travel of the belt (Arrow C in FIG. 19) remains the same but in the FIG. 19 construction, the articles travel with the belt rather than oppositely to it. It will be observed that the arrangement of the support units in each group is turned end-for-end with respect to the belt travel. The other difference is that the sensing belts are positioned to contact the articles rather than the article support rollers and are, therefore, co-planar with the tops of the rollers 100.
The operation of the modified construction is the same as that of the construction illustrated in FIGS. 1-18. An article stalled on the rollers of group 1 will stall the sensing belt 80 of that group which will terminate drive through pulley 66 to the secondary drive belt 83 interconnecting it to the support units 20 and 20a of the next upstream group. This arrangement is repeated along the entire portion of the conveyor designed to function as an accumulator.
The invention has the advantage of high throughput rates. Thus, for a given volume of articles being transported, a slower belt speed can be employed. This is advantageous not only from an energy requirement standpoint but also because it contributes significantly to noise reduction. Elimination of the conventional sensors which are tripped by the passing articles in conventional accumulators also contributes to noise reduction. When in the conveying mode, it operates continuously and no portion of the mechanism shifts to accumulation unless an article is actually stalled on the conveyor. This reduces wear and noise and it permits continuous and uniform application of movement to the articles.
Having described a preferred embodiment of the invention and its operation, it will be understood that various modifications of the invention can be made without departing from the principles thereof. Such modifications are to be considered as included in the hereinafter appended claims unless these claims by their language expressly state otherwise.
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This invention relates to accumulator conveyors. During the past two decades many types of accumulator conveyors have been developed. These utilize a variety of different operating mechanisms and principles. This invention is in the field of accumulator conveyors which rely upon shifting the primary propelling member vertically between a raised position in which the propelling member is in driving contact with the lower faces of the article supporting and propelling rollers and a lowered position in which it is disengaged from these rollers. The invention is further directed to the type of accumulator in which the shift of the conveyor from conveying to accumulation mode and return to conveying mode is automatically controlled in response to the presence of the motion or lack of motion of an article on the conveyor. Heretofore, all conveyors of this type have had some type of sensor in the form of a roller, lever, wheel or pneumatic valve which is moved or triggered by an article near or over it. It is a common characteristic of these accumulators that most of them will not close-pack the articles as they are accumulated and they have the characteristic of significantly spacing or singulating the articles as they are released from accumulation. While these are desirable characteristics under certain circumstances, there are many applications in which the efficiency of the conveyor could be improved if these characteristics were eliminated because it would increase the throughput of the conveyor for a given length and belt speed.
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BACKGROUND OF THE INVENTION
The invention relates to a process for seam welding an overlapping sheet-metal seam with a predetermined welding pressure. The invention also relates to a resistance seam welding machine for carrying out the process.
It is known that when a sheet-metal seam is welded by the roller seam welding process the initial weld spot is often incompletely welded. This is particularly disadvantageous in the production of can bodies, as the affected body has to be removed from the production line.
The problem of the initially unwelded or poorly welded seam has a number of causes. First of all, the leading end of the can does not benefit from any transfer of heat from a length of seam which has already been welded, and second, the insertion of the can body between the two roller electrodes, which forces these electrodes apart, causes a force to be exerted on the seam which is additional to the welding force which has been set, owing to the inertia of the electrodes. Furthermore, excessive welding pressure is applied at the edge of the can body, as, with welding force constant, less surface area is acted on than along the seam.
The increased welding force and/or increased welding pressure at the start causes a marked reduction in the electrical resistance in the sheet between the roller electrodes. Since the welding current is constant, the power input to the weld seam at the start of the can body changes in proportion to the said reduction in resistance. The measure adopted hitherto to counteract this has been to increase the welding current at the commencement of welding. The power input P to the sheet-metal is equal to the square of the welding current multiplied by the sheet resistance. Hence the reduction in sheet resistance at the commencement of welding can be compensated by a corresponding boost in current. However, the number of can bodies welded per minute is continually being increased. The can bodies are being fed into the welding plane more and more rapidly, and ever-increasing peak forces are occurring which in many cases can no longer be satisfactorily compensated by increasing the current.
A further problem is mechanical vibration of the welding electrodes which is set off by the peak forces at the starting edge of a can body. Efforts have been made to keep this vibration as small as possible by reducing the mass of one of the electrodes.
SUMMARY OF THE INVENTION
An object of the invention is to provide a roller seam welding process in which these problems at the commencement of welding do not occur, or are significantly reduced, so that the welded seam has the required properties from the start.
This object is attained in a roller seam welding process of the above-mentioned kind by reducing the welding force for the commencement of welding.
Decreasing the welding force at the start of welding can reduce to a harmless level the amount of change in the electrical resistance in the sheet whilst at the same time reducing mechanical vibration.
In a particularly preferred way of carrying out the invention, the welding force is also increased for a brief period at the end of the weld.
A further basic object of the invention is to provide a resistance seam welding machine for carrying out the process. This is accomplished by a device for reducing the welding force acting on the welding rollers for a period of time, which is short in relation to the overall welding time.
From the document CH-A 660989, it is known that the welding pressure can periodically be raised and lowered throughout the entire welding procedure to simulate the effect of modulating the welding current. The problem of insufficient power input at the start of welding is not dealt with in this document. In the present invention, on the other hand, the welding pressure is kept constant as nearly as possible, and this is achieved by a brief reduction in welding force at the commencement of welding.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in detail with reference to the drawings, in which:
FIG. 1 shows the ideal characteristic curve of welding force as a function of time;
FIG. 2 shows the curve of welding force as a function of time as obtained with a device according to the invention;
FIG. 3 is a schematic illustration of the welding force adjuster on a roller seam welding machine;
FIG. 4 shows a part of the welding force adjuster in FIG. 3;
FIG. 5 is another schematic illustration of a welding force adjuster;
FIG. 6 shows a part of the welding force adjuster in FIG. 5; and
FIG. 7 is a diagram illustrating a cascade of piezo-elements according to the invention, and FIGS. 7B, 7C, and 7D are graphs illustrating the reduction in welding force with the arrangement according to FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the welding force at the welding rollers of a roller seam welding machine as a function of time. The diagram assumes that bodies for cans are being welded at a rate of 750 bodies per minute. This means that a time of 80 ms is available for each body. At the start of each welding phase, that is when the can body is inserted between the welding rollers, the welding force is ideally abruptly reduced as indicated by the vertical drop in the welding force curve every 80 ms. Here the welding force is reduced, eg. from the specified level of 50 daN to 15 daN. At the start of the can body, when the body is inserted, this reduction in the welding force results in a welding pressure which approximately corresponds to the welding pressure required, and hence to the welding pressure which is effective for the rest of the weld with a welding force of 50 daN. In the illustrated example, the reduction in welding force is effective for approximately 4% of the height of the can body, or during the first 4% of the weld time. A preferred range is between 2% and 15% of the weld time. After the maximum fall in welding force, the welding force ideally climbs again, not abruptly, but continuously, as shown in FIG. 1.
The reduction in welding force may, of course, occur over a somewhat longer or shorter period of time than that shown. This will depend on the type and thickness of the sheets to be welded and--in respect of the electrode vibration to be avoided--on the mass of electrodes. The extent of the drop in welding force can, of course, be selected over a wide range. The drop in welding force at the commencement of welding is preferably made sufficiently large to remove the need for a boost in current altogether, ie. there is practically no reduction in resistance at the edge of the can body, or upon insertion of the can body, due to the drop in welding force or welding pressure.
The momentary drop in welding force can of course be brought about in many ways. The reduction in force is preferably obtained by a hammer which is controlled by the welding cycle timer to act momentarily on the support for the welding electrode so that the welding force at the latter is reduced by the hammer blow. The hammer is preferably actuated by a magnetic coil. FIG. 2 shows the welding force as a function of time for a device of such a construction with an electromagnetically actuated hammer. The number of can bodies per minute is the same as for the ideal characteristic curve in FIG. 1: a rapid drop in welding force again occurs every 80 ms. In this case, the welding force is reduced to about half. After the rapid drop in welding force, there is a somewhat more gradual climb to the required level of welding force, which yields the required welding pressure along the remaining part of the seam.
FIG. 3 shows in schematic form a welding force adjuster on a seam welding machine for can bodies. On this machine the individual can body 1 is advanced along a guide 2 to the welding rollers. A lower welding roller 3 is provided on an arm 6, and an upper welding roller 4 is provided on an arm or movable rocker 7. Welding is performed by means of an electrode wire 5. Such a device is known. The welding force is adjusted, likewise in a known manner, by means of a welding force spring 8 attached to the machine frame 10. This welding force spring 8 acts via the rod 11 on the rocker 7 and hence on the upper welding roller 4. The welding force can be set to a predetermined value by varying the initial compression of the welding force spring 8 by means of an adjuster 9.
The device illustrated is also provided with an arrangement for periodic reduction of the welding force. This acts via a connecting pin 14 on the rod 11 and hence on the rocker 7 and the welding roller 4. The connecting pin 14 extends upwards through a part of the machine frame 10 and is widened at its opposite end to the welding force spring 8 into a connecting pin head 15. This can be seen in more detail in FIG. 4, in which the upper end of the connecting pin 14 is illustrated on a larger scale. At its upper end 14, the connecting pin is surrounded by a hammer 19 which is held between two compression springs 17 and 18 on the machine frame 10. A part of the hammer 19 and the upper compression spring 17 are surrounded by a magnetic coil 20.
To reduce the welding force at the start of the can body, the magnetic coil 20 is activated and deactivated under the control of the welding cycle timing. When, upon activation, a current is passed through the magnetic coil 20 the compression spring 18 is shortened in the magnetic field which is created, and the hammer 19 is moved upwards into the interior of the magnetic coil 20. The hammer, being magnetizable, is also pulled upwards into the interior of the coil. This is characteristic produces the early part of the curve shown in FIG. 2. The hammer accelerates over the distance d (FIG. 4) and then strikes the head 15 of the connecting pin 14 to exert on the connecting pin 14 a force which is directed upwards in the drawing and which counteracts the force exerted by the welding force spring 8 on the welding roller 4. Thus the effective force at the start of welding the can body is reduced by the blow of the hammer 19 on the connecting pin head 15, eg. to less than half that required subsequently to produce the set welding pressure. Upon the ensuing deactivation of the magnetic coil 20, the magnetic field decays relatively slowly, causing the spring within the magnetic field to relax and the normal welding force, determined by the welding force spring 8 only, to be restored.
With this device, it is possible to influence the amplitude of the force-peak by the mass of the hammer and by the field strength of the coil. As already stated, the activation and deactivation of the magnetic coil 20 are synchronised with the weld cycle timing, an adjustable time function element being provided between the cycle timer and the supply circuit for the magnetic coil 20. The polarity is inverted upon each pulse to prevent permanent magnetization.
FIG. 5 shows a further configuration of the welding force adjuster. A can body 21 passes along a guide 22 to the welding rollers 23 and 24 which are arranged on arms 26 and 27 respectively. Welding is performed using the wire 25 as intermediate electrode. The welding force is normally set, as already described, by means of the welding force spring 18 which acts via the rod 31 on the upper welding roller 24. The exertion of force at the start of the can body to reduce the welding force is in this case obtained by a cascade 35 of individual piezo-elements, illustrated in FIG. 6 on an enlarged scale. This cascade is arranged in a casing 39 which is mounted in a guide 29 so as to be freely movable vertically. Through a connecting pin 34, this cascade acts directly via the rod 31 on the upper welding roller 24. The individual piezo-elements, of which there are ten in the illustrated example, two being designated 36 and 37, are kept under load by disc springs to prevent disruptive tension stresses from occurring. When a voltage is applied to the cascade of piezo-crystal elements, the thickness of each element is reduced by a certain amount, and the length of the entire cascade is reduced by ten times that amount.
The stack of piezo-elements in its protective sleeve sits on the connecting pin 34. It is surrounded by a casing 39 which on the one hand serves to transmit the force of the disc springs ad on the other hand serves as a weight which is displaced by the expansion of the piezo-cascade (by exploiting the inertia). This displacement of the casing generates a force. As it is released by the cascade, which sits on the connecting pin, an opposing force is produced at that point.
The casing 39 is therefore displaced upwards by the expansion of the piezo-cascade. Meanwhile the cascade is pushed down on the connecting pin plate 34 which transmits a positive force via the rod 31 to the welding roller 24 (increasing the welding force).
This operation takes place before the first can body is inserted. When the start of the can body is pushed between the welding rollers, the voltage is reset (discharging the cascade).
This produces a reversal of the process described above, that is to say, the piezo-elements contract, and the load in the disc springs pulls the casing back in the opposite direction. A negative force is exerted on the connecting pin and the welding force is reduced.
The force curve can be modified by varying the amplitude and ramp form of the voltage.
FIG. 7A shows schematically the mode of operation of the piezo-cascade 35, the casing 39 being represented merely as a weight. The graphs of FIGS. 7B, 7C and 7D show the voltage applied to the cascade and the forces F 1 and F 2 . F 1 is the force with which the weight (casing) is displaced. F 2 is the force with which the piezo-cascade, including the weight, is displaced. F 1 is always smaller than F 2 . F 2 is the force acting on the welding roller.
In addition, the force of the welding force spring continues to act independently on the welding roller.
Both of the embodiments described as examples have the feature of not being susceptible to variations in tolerances (such as variations in sheet thickness, eccentricity of welding rollers, thermal expansion of machine components, etc.).
In the case of the electromagnetic design, such variations in tolerances can be absorbed in the distance "d".
In the case of the piezo-electric design, the entire piezo-cascade is freely mounted on the connecting pin 34, so that the cascade is able to move freely up or down in a vertical mounting in response to variations in tolerances.
According to a further aspect of the invention, the welding force can be increased at the end of a can body or series of can bodies. The increase in force at the end of a can body or series of can bodies is functionally equivalent to a reduction in welding current, and prevents overheating of the seam at the end of the body. By suitable modification of the force-reducing device, the increase in force may also be performed by this device; or an additional device may act on one of the welding rollers or on the arm or rocker.
Furthermore, by rapidly reducing or increasing the welding force, an active countermeasure against vibration can be taken by preventing the excitation of vibrations.
Other arrangements, not illustrated, for momentarily increasing and/or reducing the welding force, eg. pneumatic or hydraulic arrangements, can of course also be used.
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In a seam welding process for overlapping sheets, in particular for welding can bodies, the welding force is momentarily reduced upon each insertion of a can body between the welding rollers. This keeps the welding pressure constant even at the start of a can body. In this way the power input to the sheet can be kept constant even at the start of a can body, and the weld quality even at the start of a can body satisfies requirements.
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This application is a continuation of application Ser. No. 08/046,186 filed Apr. 14, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a camera device for a moving body such as a vehicle.
2. Related Background Art
In order to improve safety upon travelling of a vehicle, some devices, in which an image pick-up means such as a television camera is mounted on a vehicle to pick up images in the fields before and behind the vehicle, and various kinds of information included in the picked-up images are extracted and utilized, have been proposed.
For example, Japanese Patent Publication No. 57-57760 proposes a system, which detects image series motions, i.e., the movement of the vehicle, from the fetched image signals by an optical correlation system, and generates an alarm to a driver on the basis of the distances to and the speeds of surrounding vehicles.
Japanese Laid-Open Patent Application No. 1-265400 proposes a system for searching a predetermined position of a picked-up and recognized image with respect to a "road region" so as to recognize signs. In addition, many associated systems (e.g., Japanese Laid-Open Patent Application Nos. 59-127200, 62-95698, and the like) have been proposed.
In the above-mentioned prior art, the camera used in an image pick-up operation is arranged at a position allowing a clear front view, e.g., in a passenger room such as "a position behind a windshield of a vehicle, which position is protected from climatic effects" or "a position on the rear surface of a rear-view mirror", or in a hood of a vehicle (near a headlight).
However, the camera arranged in the passenger room may deteriorate from an outer appearance or from driving comfort, or may narrow the field of view of a driver. Also, the camera arranged in the hood suffers from very bad environmental conditions, and may malfunction.
When the camera is arranged on the outer surface of a vehicle, e.g., on the side surface of a door or on the hood, adverse effects in various respects such as safety, design, aerodynamics, and the like may be expected.
SUMMARY OF THE INVENTION
One aspect of the present invention is to provide a camera device, which comprises a mirror device constituted by a half mirror, and an image pick-up means for receiving light transmitted through the half mirror, and can monitor an area around a moving body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an on-board monitor camera device according to the first embodiment of the present invention;
FIG. 2 is a schematic diagram showing an on-board monitor camera device according to the second embodiment of the present invention;
FIG. 3 is a schematic diagram showing an on-board monitor camera device according to the third embodiment of the present invention;
FIG. 4 is a schematic diagram showing an on-board monitor camera device according to the fourth embodiment of the present invention;
FIG. 5 is a schematic diagram showing an on-board monitor camera device according to the fifth embodiment of the present invention;
FIG. 6 is a schematic diagram showing an on-board monitor camera device according to the sixth embodiment of the present invention;
FIG. 7 is a perspective view showing the outer appearance of the first embodiment of the present invention;
FIG. 8 is a flow chart for explaining an operation of the fifth embodiment;
FIG. 9 is a schematic diagram showing an on-board camera device according to the seventh embodiment of the present invention;
FIG. 10 is a plan view showing a support mechanism for a VAP;
FIG. 11 is a view showing an actuator for the VAP;
FIGS. 12A and 12B are views showing sensors for the VAP;
FIG. 13 is a block diagram showing a VAP driving circuit;
FIGS. 14A to 14C are views for explaining an operation of the VAP; and
FIG. 15 is a flow chart for explaining an image stabilizing operation of the seventh embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic diagram showing an on-board monitor camera device according to the first embodiment of the present invention.
In this embodiment, a camera is built in a door mirror 1, which is arranged to project outwardly from a door of a vehicle (see FIG. 7). The camera is constituted by a lens 4 and an image pick-up element 5 such as a CCD. An optical filter such as an infrared ray cut filter is provided to the lens 4.
The door mirror 1 has a hollow case, and a mirror 2 for confirming a rear view is constituted by a half mirror. The camera (constituted by the lens 4 and the image pick-up element 5) arranged in the case picks up an image, e.g., behind a vehicle through the half mirror 2.
The on-board monitor camera device of this embodiment with the above arrangement may be arranged in one or both of the door mirrors provided at the two sides of the vehicle. For example, a driver can monitor areas at the two sides of the vehicle by images formed on the half mirrors 2, and the image transmitted through each half mirror 2 is picked up by the image pick-up element 5 via the lens 4.
The image picked up by the image pick-up element 5 is photoelectrically converted into an electrical signal, and the electrical signal is input to a camera signal processing circuit 8 via a cable 7. The camera signal processing circuit 8 executes processing such as Y/C separation, γ correction, and the like, and the processed image is visualized on a monitor 9 arranged in a passenger room. Thus, when the monitor 9 is arranged at an easy-to-see position by a driver or a passenger, he or she can easily monitor side rear areas of the vehicle. In addition, when a signal from the camera signal processing circuit is supplied to an image designator 10, various operations described in the paragraphs of the prior art can be performed.
FIG. 2 shows the second embodiment of the present invention.
In the first embodiment shown in FIG. 1, the optical filter is provided to the lens 4. However, in this embodiment, an optical filter 3 is arranged on the inner surface of the half mirror 2 in place of being arranged on the lens 4.
More specifically, in a normal video lens, an optical filter is arranged in front of an image pick-up element. In this embodiment, the optical filter 3 is arranged integrally with the half mirror 2 so as to achieve a further compact structure. As the optical filter, two kinds of filters, i.e., an infrared ray cut filter and a low-pass filter, are normally used. In order to integrally arrange these filters on the half mirror 2, the two filters may be adhered by deposition, or a quartz film or the like may be adhered using an adhesive.
When the camera is used for monitoring using infrared rays, the optical filter adopts a visual light cut filter and an infrared ray transmission filter.
FIG. 3 shows the third embodiment of the present invention.
A difference in this embodiment from the first embodiment is that the half mirror 2 comprises an ND filter 20 whose transmittance can be varied by a voltage. The ND filter 20 is driven by a variable ND filter driver 15.
Since a vehicle travels outdoors, as a matter of course, the light amount with respect to the camera considerably changes depending on sunlight, headlights of other vehicles, and the like. For this reason, the video lens requires an aperture system having sufficient performance. As this system, of course, a system for driving an IG meter (aperture driving source) in the video lens according to the luminance component of a camera signal to open/close aperture blades and to adjust the transmission light amount may be adopted like in the prior art. In order to achieve a further compact structure, in this embodiment, a material such as an LCD (liquid crystal), EC (electrochrocy), or the like whose transmittance changes according to an applied voltage is used in the half mirror 2, and the output from the variable ND filter driver 15 is changed on the basis of the luminance signal, thereby adjusting the amount of light input to the lens 4.
FIG. 4 shows the fourth embodiment of the present invention.
In this embodiment, an optical fiber 40 is used in place of the electrical signal transmission cable 7 in the first embodiment, the image pick-up element 5 is arranged at the end portion of the optical fiber 40, which extends into a passenger room, and light received by the video lens 4 is input to the image pick-up element 5 via the optical fiber 40. More specifically, the door mirror is required to have a more compact structure, and in order to meet this requirement, the image pick-up element and the lens are separately arranged in place of integrating them, and the image pick-up element is arranged in, e.g., a passenger room together with the camera signal processing circuit.
FIG. 5 shows the fifth embodiment of the present invention.
As the characteristic feature of this embodiment, a driving unit for rotating the video lens 4 in yaw and pitch directions is added to the first embodiment.
An device shown in FIG. 5 includes a yaw panhead driving unit 6a, a pitch panhead driving unit 6b, a motor driver 11 for driving a mirror angle changing motor (not shown), motor drivers 12 and 13 for driving the driving units 6a and 6b, and an operation key unit 14 for these drivers.
The mirror angle of the door mirror is changed to a corresponding easy-to-see position every time a driver is changed. Recently, many systems electrically attain this operation using operation keys in the passenger room in place of a manual operation. In this embodiment, in order to electrically perform this operation, the mirror angle changing motor (not shown) can be operated via the motor driver 11 by the operation key unit 14 arranged in the passenger room.
The drivers 12 and 13 are independently operated, and for example, the camera alone can be directed obliquely downward or upward. More specifically, when the vehicle is moved backward, since a lower view of the side rear views is important, the lens can be directed obliquely downward. When the vehicle travels on a bumpy road, the lens can be directed immediately downward to monitor the road condition.
Upon execution of the above-mentioned operation, the operation key unit 14 may be manually operated when the vehicle is moved backward. Alternatively, the camera may be automatically directed in a predetermined direction, e.g., a lower backward direction. Such an automatic mechanism will be described below.
A back gear detector 16 detects whether or not the gear of a transmission (not shown) of the vehicle is set at a back (reverse) gear position. When the back gear position is selected, the detector 16 supplies an ON signal to the operation key unit 14. In this automatic mechanism, a control circuit is provided to the operation key unit 14, and upon reception of a signal from the back gear detector 16, the control circuit outputs an operation signal for driving the drivers 12 and 13 in a predetermined direction (lower backward direction). Each panhead driving unit is provided with an encoder (not shown) for detecting the direction of the camera, and outputs a detection signal to the control circuit of the operation key unit 14.
The automatic driving operation with the above arrangement will be described below with reference to the flow chart shown in FIG. 8.
If it is determined in step 81 that the back gear detector 16 is OFF, i.e., the back gear position is not selected, a manual operation mode is set (step 82). On the other hand, if it is determined in step 81 that the back gear detector 16 is ON, i.e., the back gear position is selected, the operation key unit 14 is automatically operated to drive the driving units in a predetermined direction (step 83).
The driving units are automatically driven until the encoder output values that coincide with corresponding predetermined values (step 84), and after a coincidence is determined, the driving units are stopped (step 85). As a result, the camera is directed in a direction suitable for monitoring areas around the vehicle when the vehicle is moved backward.
When the camera lens is turned through 180° with respect to the mirror (i.e., is directed forward), the camera can be used as a front monitor camera. At this time, a mirror case portion 1a constituting the door mirror is also constituted by, e.g., a half mirror.
FIG. 6 shows the sixth embodiment of the present invention.
In this embodiment, the same signal is input to the yaw and pitch panhead units and the angle changing motor for the half mirror 2, so that the mirror and the camera are interlocked with each other while maintaining a predetermined relationship therebetween.
In addition to the arrangement of the fifth embodiment shown in FIG. 5, a signal converter 15, which supplies signals from the operation key unit 14 to the corresponding drivers 11 to 13, so that the mirror and the camera are interlocked with each other, is provided.
For example, when the mirror and the camera are set by the signal converter 15 so that the mirror surface of the half mirror 2 is substantially perpendicular to the camera optical axis, even if the mirror angle is changed by another driver, the same image as that observed by a current driver can be displayed on the monitor.
In each of the above embodiments, a lens or a combination of a lens with the an pick-up element is arranged in the door mirror of the vehicle. Alternatively, the lens, and the like may be arranged in a fender mirror.
The above embodiments may be properly combined.
As described above, according to the above embodiments, a video camera or a combination of a lens with an optical fiber is arranged in a mirror unit such as a door mirror, fender mirror, or the like of a vehicle, and image information around the vehicle is fetched via a mirror portion comprising a half mirror. Therefore, the camera, and the like can be protected from climatic effects, no problem of safety is posed since a mirror such as a door mirror, which complies with safety standards of vehicles, can be used, and the design or aerodynamics of the vehicle can be prevented from being impaired.
When the mirror portion is arranged to have a variable transmittance, the light amount guided to the image pick-up element can be adjusted, and the entire device can be rendered compact as compared to a case using a mechanical aperture device.
Furthermore, when an optical filter for a lens is provided to the mirror portion, or an image is guided to the image pick-up element via an optical fiber, the device can be further rendered compact.
FIG. 9 is a schematic diagram showing an on-board camera device according to the seventh embodiment of the present invention.
The on-board camera device of this embodiment is arranged in a door mirror 1 of a vehicle shown in FIG. 7.
The device shown in FIG. 9 includes a variable angle prism (to be abbreviated as a VAP hereinafter) 102 which also serves as a mirror portion of the door mirror 1, a video lens 103, and an image pick-up element 104 such as a CCD. The video lens 103 and the image pick-up element 104 are integrally assembled to constitute a video camera, and the video camera receives light transmitted through the VAP 102. A photoelectric conversion signal from the image pick-up element is output to a signal processing circuit 107 arranged in a passenger room via a signal transmission cable 105 of, e.g., a flexible printed circuit board, and a video output from the signal processing circuit 107 is output to a monitor 106 and an image designator 108. Note that the video camera is fixed to the door mirror 1.
The VAP 102 is constituted by sealing a liquid between opposing glass plates 102g and 102h, and varies an apex angle formed between the two glass plates 102g and 102h by moving the glass plates 102g and 102h. Since the operation principle of the VAP is known to those who are skilled in the art, a description thereof will be omitted.
The front-side glass plate 102g is formed as a half mirror by a coating layer 102a formed on its surface, and the glass plate 102h consists of a transparent glass. Therefore, the glass plate 102g provides a rear view to a driver in the same manner as a mirror portion of a normal door mirror. An optical image transmitted through the glass plate 102g is picked up by the video camera via the VAP 102. Thus, when the monitor 106 is placed at an easy-to-see position for the driver or a passenger, he or she can easily monitor side rear areas of the vehicle.
The glass plate 102g is driven by an actuator 102b, and the glass plate 102h is driven by an actuator 102d. The angle of the glass plate 102g is detected by a sensor 102c, and the angle of the glass plate 102h is detected by a sensor 102e. These actuators 102b and 102d and the sensors 102c and 102e are attached to the door mirror 1 via gimbal ring support mechanisms (to be described later). A vibration detection sensor 102f is attached to the video lens 103.
The half mirror 102g and the glass plate 102h of the VAP 102 are supported by gimbal ring support mechanisms having the same structure. FIG. 10 shows the gimbal ring support mechanism for the half mirror 102g. Since the gimbal ring support mechanism for the glass plate 102h is the same as that shown in FIG. 10, a detailed description thereof will be omitted.
In FIG. 10, an angular inner ring member 110 holds the half mirror 102g, and has opposing pins 110a and 110b along an axis 116. These pins 110a and 110b allow the ring member 110 to be rotatable about the axis 116. A middle ring member 111 is arranged on the outer circumference of the inner ring member 110, and the pins 110a and 110b of the inner ring member 110 are axially supported by the middle ring member 111.
Pins 111a and 111b project from the middle ring member 111 along an axis 115 perpendicular to the axis 116. These pins 111a and 111b are axially supported by an outer ring member 112, so that the middle ring member 111 is rotatable about the axis 115. Note that the outer ring member 112 is attached to the door mirror 1.
The ring members 110 and 111 are respectively provided with coils 102b-a and 113 and slits 102c-a and 114, which respectively constitute actuators for applying torques about the axes 115 and 116, and sensors for detecting angular displacements about the axes 115 and 116.
The operation principles of the actuators and sensors will be described hereinafter with reference to FIG. 11 and FIGS. 12A and 12B.
FIG. 11 shows the operation principle of each actuator.
In FIG. 11, a magnet 102b-b, and yokes 102b-c and 102b-d are attached to a stationary portion of the door mirror 1. When the coil 102b-a attached to the inner ring member 110 is energized, an electromagnetic force is generated between the magnet 102b-b and the coil 102b-a, and the coil 102b-a can be moved in the direction of an arrow in FIG. 11. Thus, a torque, which can pivot the half mirror 102g about the axis 116 (FIG. 10), can be applied. As for the coil 113, a rotational torque about the axis 115 can be applied by the same actuator arrangement as described above.
FIGS. 12A and 12B show the operation principle of each sensor.
A light-receiving element 102c-b such as a PSD and a light-emitting element 102c-c such as an iRed are held by a member 102c-d, which is attached to the stationary portion of the door mirror 1. As shown in FIG. 12B, the slit 102c-a is provided to the inner ring member 110, and is moved together with the inner ring member 110 in the direction of an arrow in FIG. 12B so as to change the light-receiving position of light, which is emitted from the light-emitting element 102c-c and is received by the light-receiving unit 102c-b, on a light-receiving surface 102c-b', thus detecting the displacement of the slit 102c-a. In this manner, the angular displacement of the inner ring member 110 can be detected. As for the slit 114, the angular displacement of the middle ring member 111 can be detected in the same manner as described above.
With the above arrangement, the half mirror 102g can realize a movement having degrees of freedom about two axes by a gimbal ring support mechanism. Also, the glass plate 102h can realize a movement having degrees of freedom about two axes by the same arrangement. Therefore, the half mirror 102g and the glass plate 102h can be independently moved.
FIG. 13 is a block diagram of an image stabilizer circuit. Note that FIG. 13 explains an operation about only one axis. However, since an operation about the other axis is realized by the same arrangement, and these two operations are independently controlled, a detailed description of the operation about the other axis will be omitted.
Since the mirror portion on the front surface of the VAP 102 is the half mirror 102g, a driver checks safety of the vehicle by observing an image on the half mirror 102g. However, the vehicle is always vibrated according to a road state and traveling conditions, and an image formed on the half mirror is also vibrated and is not easy to see.
Therefore, this vibration is detected by a vibration detection sensor 102f and a vibration detection circuit 119. The detected signals and signals from the angle detection sensor 102c of the half mirror 102g, and a detection circuit 118 are compared by an image stabilizer control circuit 109, and the circuit 109 supplies displacement information according to the vibration to a coil driving circuit 117 so as to drive the half mirror 102g and the glass plate 102h, thus providing a stable image free from a vibration to the driver.
An image fetched by the video camera is also vibrated for the same reason as described above, and a displacement according to the vibration is similarly applied to the glass plate 102h, thus providing a stable image to the image pick-up element 104. Thus, various operations described in the prior art can be executed with high precision.
The details of the image stabilizing operation of the VAP 102 will be described below with reference to FIGS. 14A to 14C. FIGS. 14A to 14C show an operation about only one axis. Since the same operation is performed about the other axis, a detailed description thereof will be omitted.
FIG. 14A shows a state wherein no vibration occurs. A driver 122 obtains a rear view by the half mirror 102g. The video camera similarly obtains an image behind the vehicle.
A correction performed for the half mirror 102g when a vibration at an angle α occurs, as shown in FIGS. 14B and 14C, will be described below with reference to FIG. 14B.
When the entire vehicle is vibrated at the angle α, the driver 122 is also vibrated at a certain angle, as a matter of course. If the driver is completely fixed to the vehicle, he or she is similarly vibrated at the angle α. However, in practice, since the driver 122 has a degree of freedom with respect to the vehicle, the deviation angle of the driver is not the same as α. For this reason, assume that the gazing line of the driver is vibrated by an angle (mα) obtained by weighting α (where m is a constant determined by specifications of each vehicle since it varies depending on the positional relationship between the vehicle and the mirror).
When the gazing line of the driver is vibrated by ms, the mirror is inclined by mα/2 with respect to the position shown in FIG. 14A, so that the driver 122 can observe the same object at an identical position in the field of view. Therefore, a stable image can be obtained by inclining the half mirror 102g by mα/2 in the same direction as that of the vibration α. In practice, since the VAP 102 is inclined by α in the same direction as the camera before it is driven, the half mirror is driven in a direction (clockwise in FIG. 14C) opposite to the vibration direction by (α-mα/2).
The image stabilizing operation for the video camera will be described below with reference to FIG. 14C.
If the apex angle of the VAP 102 is represented by ε, and the refractive index of the liquid sealed in the VAP is represented by nd, α=ε(nd-1) is satisfied with respect to the inclination α of the optical axis. Therefore, when the vibration α occurs, the apex angle of the VAP 102 can be given by ε=α/(nd-1). In other words, when the vehicle is vibrated at the angle α, if the apex angle of the VAP 102 satisfies ε=α/(nd-1), the video camera can obtain a stable image free from the vibration.
From the above description, the actual driving angle of the glass plate 102h is (α/(nd-1)-mα/2+α), and when the glass plate 102h is driven by (α/(nd-1)-mα/2+α) in a direction opposite to the vibration direction, a stable image free from the vibration can be provided to the video camera.
FIG. 15 is a flow chart of the above-mentioned image stabilizing operation. The operation will be described below.
Step 101: The deviation angle of the door mirror 1 is detected. More specifically, the output from the vibration detection sensor 102f substantially fixed to the door mirror 1 is amplified by the vibration detection circuit 119, and the amplified output is supplied to the image stabilizer control circuit 109.
Step 102: The driving angle (α-mα/2) of the half mirror 102g is calculated based on the deviation angle α output in step 101, and an instruction signal is supplied to the coil driving circuit 117.
Step 103: The coil 102b-a is energized according to the signal output from the image stabilizer circuit 109.
Step 104: The angular displacement of the driven half mirror 102g, i.e., the output from the VAP apex angle sensor 102c is amplified by the VAP apex angle detection circuit 118, and the amplified output is supplied to the image stabilizer control circuit 109.
Step 105: The half mirror 102g is kept driven until the angular displacement of the half mirror 102g reaches (α-mα/2) on the basis of the signal from the VAP apex angle detection circuit 118, and when the angular displacement reaches (α-mα/2), the flow returns to step 101.
Step 106: The driving angle of the glass plate 102h is calculated by [α/(nd-1)+α-mα/2] on the basis of the door mirror deviation angle α calculated in step 101, and an instruction signal is output to a coil driving circuit 120.
Step 107: The coil 102d-a is energized according to the signal output from the image stabilizer control circuit 109.
Step 108: The angular displacement of the driven glass plate 102h, i.e., the output from the VAP apex angle sensor 102e is amplified by a VAP apex angle detection circuit 121, and the amplified output is supplied to the image stabilizer control circuit 109.
Step 109: The glass plate 102h is kept driven until the angular displacement of the glass plate 102h reaches [α/(nd-1)+α-mα/2] on the basis of the signal from the VAP apex angle detection circuit 118, and when the angular displacement reaches [α/(nd-1)+α-mα/2], the flow returns to step 101.
Upon repetition of steps 101 to 109 described above, the image stabilizing operation can be satisfactorily performed.
As described above, according to the above embodiment, the optical path is displaced according to the vibration of the vehicle, and the image pick-up means can pick up an image free from the vibration.
In particular, since the mirror unit of the vehicle such as a door mirror, a fender mirror, or the like is utilized, protection against climatic effects and safety of the vehicle can be guaranteed, and design or aerodynamics can be prevented from being impaired.
Furthermore, since the optical means such as the VAP also serves as the mirror portion of the mirror unit, an image directly observed by the driver through the half mirror can have the same state as that of an image picked up by the image pick-up means.
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Camera apparatus for use with an automotive vehicle having a rear view mirror. The rear view mirror comprises a half-mirror, light reflected therefrom being visible to an occupant of the vehicle. A lens is disposed adjacent to the half-mirror and receives light passing through the half-mirror. An image pickup device is optically coupled to the lens and receives light passing therethrough to form an image signal corresponding to the received light.
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CROSS REFERENCES TO RELATED APPLICATIONS
The following U.S. patent applications filed concurrently herewith are assigned to the same assignee hereof and contain subject matter related, in certain respects, to the subject matter of the present application, the teachings of which applications are incorporated herein by this reference:
Serial No. 09/657,215, entitled “System and Method for Clustering Servers for Performance and Load Balancing”;
Serial No. 09/657,216, entitled “System and Method for Front End Business Logic and Validation”;
Serial No. 09/657,217, entitled “System and Method for Data Transfer With Respect to External Applications”;
Serial No. 09/656,803, entitled “System and Method for Providing a Role Table GUI via Company Group”;
Serial No. 09/656,967, entitled “System and Method for Populating HTML Forms Using Relational Database Agents”;
Serial No. 09/657,196, entitled “System and Method for Catalog Administration Using Supplier Provided Flat Files”; and
Serial No. 09/657,195, entitled “System and Method for Providing an Application Navigator Client Menu Side Bar”.
TECHNICAL FIELD OF THE INVENTION
This invention pertains to a system and method for managing a requisition catalog on the web.
BACKGROUND ART
A requisition catalog for a large enterprise in a web environment must enable very fast access to a very large database from a large number of clients. A large number of clients is required for optimal performance of a catalog system. There is a need to architect such a system so as to be scalable, that is, capable of providing that fast access to an ever increasing number of clients and a growing database or collection of databases.
In a requisition catalog system for a large enterprise in a web environment, there is a requirement for a system and method for insuring that all general ledger accounts associated with commodities are correct, and within this requirement for providing a description from the associated accounting system for use by customer or requester to select the correct general ledger (GL) account when doing financial validation on a requisition.
A requisition catalog for a large enterprise is stored in a very large database. However, a Lotus Notes database has a hard limit of 2 to 4 gigabytes of data. That is, Notes puts its entire database into one big Notes standard format(.nsf) file. Information in such a nsf file is accessed by a system geometrically. As a result, such a system slows down significantly as it accesses larger files. This slow down ramps up rather badly. Consequently, the hard limit is artificially put in because of this ramp up in access time. The typical solution to this problem is to split a very large database into many smaller databases. Lotus Notes has a Lotus connector/Lotus script extensions connector (LCLSX). This allows connection to other databases but these script extensions are not set up to actually be the database. There is a need in the art for a system and method for utilizing Lotus script extensions in combination with a relational database to provide high capacity storage without performance degradation.
In building a requisition catalog for a large enterprise with many suppliers, an automated process is needed to receive a flat file from a supplier for review by a buyer before being externalized for use by requesters. While the buyer must be able to review the contents, he must be restricted from making changes to certain sensitive fields, such as changing a unit price or a unit of measure, both of which could constitute fraud. Consequently, allowing the buyer to edit the flat file can't provide the level of security required. There is a need in the art to provide a buyer a means of auditing catalog content before externalizing it to production for access by requesters.
A requisition catalog for use in a web environment requires a very large database, such as an IBM DB 2 database, and the functionality provided by, for example, a Lotus Notes server. However, a Lotus Notes access control list (ACL) can not be used control access to an IBM DB 2 database, and the privileges on a DB 2 table can be granted only by the table instance owner. Additionally, since Notes agents which access DB 2 are running from a Notes server, the Notes server ID often has full access to all tables, and there is no way to limit that. That is, in a hybrid (Notes/DB 2 ) environment, the user ID which accesses DB 2 tables is the ID of the Notes server. Therefore, can't restrict access by a user to the DB 2 tables. There is a need in the art for a system and method which allows certain users access to certain data in certain selected tables. That is, there is needed a system and method for providing very flexible access to DB 2 tables without requiring database administrator (DBA) involvement to issue grants against the tables, and bypassing the problem caused by Notes agents all coming from the same user (the Notes server ID).
In a hybrid requisition catalog system for use in a web environment, much of the application data is stored in, for example, IBM DB 2 tables. However, a web interface written in Java script and in HTML does not have functionality for connecting to DB 2 and reading data from DB 2 tables. No function is provided in Java script and in HTML to connect to or access such a database. It is not presently possible to make the connection by connecting to the database and executing SQL queries. Consequently, there is a need in the art for a system and method utilizing an existing infrastructure including Lotus Notes, Domino Go, and DB 2 to combine HTML and Java script web presentation with DB 2 data.
In a requisition catalog system for use in a web environment by a large enterprise, there must be provide a way to deal with web sites that exist outside of a firewall, or internal applications within the firewall but outside of the requisition catalog (Req/Cat Web or RCW) application. That is, a system and method is required for transfering a large quantity of data back from such a web site or application to the RCW application in a timely manner. One possible way is to send data on the universal resource locator (URL). However, such a URL is limited to 1 K bytes, which is not enough to do the task quickly for the quantities of information required. Information can be put into a frame, and that information can be read, but only if the information is written and read by the same server.
In a preferred system, the RCW application exists in a frame set in a browser. As part of security for such a browser, Netscape and Internet Explorer (IE) establish ownership of the frames: each frame is a window under control of the browser. A user can open up a session in any frame desired. However, if all of the frames are not owned by same session, then these frames not commonly owned cannot see the contents of each other. In Netscape version 4.51 frame ownership was changed to protect against frame spoofing. Frame spoofing is a way other servers can use to trick the owner of a frame into thinking it had created a frame actually created by someone else, enabling access to data not owned. Netscape 4.51 plugs that hole.
Consequently, in the new environment (with spoofing inhibited) a problem is presented: if a RCW application needs to access an outside supplier site for information to get back through one its own the frames, as soon as data is written by that outside supplier site into one of the frames owned by RCW, ownership of the frame is transferred from RCW to the supplier; RCW no longer owns the frame and cannot access the information. A system and method is needed to enable transfer of data from a supplier site to a RCW application which does not entail frame spoofing.
In a web application, such as a requisition catalog system for a large enterprise, a fast browser interface and navigator is needed, including a very fast graphical user interface (GUI).
There is known in the art several Internet applications which provide a strip down, for example, the left hand side of a window that has menu of items from which a user may select. Such windows also may display a header, including header type items which will expand upon selection into a drop down list. Such windows also may include a footer including leafs which will, upon selection, change what is seen on right side of screen. Such applications provide a very nice user interface for documents, with a table of contents (TOC) on the left, and on the right the selected contents.
However, these expandible and collapsible menus are characteristically slow. This slowness is a result of every click sending a request to a remote server, which server responds by sending information back to expand the list at the browser. Every click on the web is slow, involving communications of the request and response over a relatively slow web communication link. There is, therefore, a need in the art to dramatically increase the speed of operation of a graphical user interface at a browser.
It is an object of the invention to provide a scalable database system in a web environment with optimal access performance characteristics for an expanding number of clients and a growing database.
It is an object of the invention to provide a system and method for enabling a requester to select the correct general ledger account when doing financial validation on a requisition.
It is an object of the invention to provide a system and method for utilizing Lotus script extensions in combination with a relational database to provide high capacity storage without performance degradation.
It is an object of the invention to provide a system and method for enabling a buyer a means for editing catalog content before externalizing it to production for access by requesters.
It is an object of the invention to provide a system and method for providing very flexible access to DB 2 tables without requiring database administrator (DBA) involvement to issue grants against the tables, and bypassing the problem caused by Notes agents all coming from the same user (the Notes server ID).
It is an object of the invention to provide a system and method utilizing an existing infrastructure including Lotus Notes, Domino Go, and DB 2 to combine HTML and Java script web presentation with DB 2 data.
It is an object of the invention to provide a system and method for enabling transfer of data from a supplier site to a RCW application which does not entail frame spoofing.
It is an object of the invention to provide a system and method for dramatically increasing the speed of operation of a navigation frame of a GUI.
SUMMARY OF THE INVENTION
A system and method for managing access to a relational database. Responsive to a database operation to a non-relational database, the database operation is interrupt and a core application programming interface substituted therefore which includes a configuration class for defining valid connection indicia and a base class containing procedures for connecting to the relational database.
Other features and advantages of this invention will become apparent from the following detailed description of the presently preferred embodiment of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a high level system diagram illustrating a clustered configuration of servers for performance and load balancing.
FIG. 2 is a diagram illustrating proxying out of URLs to clustered servers.
FIG. 3 is a system diagram illustrating a specific example of a clustered configuration of servers.
FIG. 4 is a diagram illustrating the frames comprising a typical screen display.
FIG. 5 is a diagram illustrating a specific instance of the display of FIG. 4 .
FIG. 6 is a diagram illustrating ZIP code validation.
FIG. 7 is a diagram illustrating requisition catalog searching.
FIG. 8 is a diagram illustrating the mapping of commodity codes to accounting codes.
FIG. 9 is a diagram illustrating a commodity document.
FIG. 10 is a diagram illustrating a pyramid structure of application program interfaces.
FIG. 11 is a diagram illustrating the graphical, database, and business logic API's of the pyramid structure of FIG. 10 .
FIG. 12 is a diagram illustrating the interaction of API's with each other, a database, and a browser.
FIG. 13 is a diagram illustrating an example configuration of API's.
FIG. 14 is a flow diagram illustrating the operation of the userProfile class of FIG. 13 .
FIG. 15 is a system diagram illustrating the system of FIG. 1 for accessing a requisition catalog.
FIG. 16 is a system diagram illustrating a system for using a staged requisition catalog built from supplier flat catalog files.
FIG. 17 is a flow diagram illustrating the steps for receiving a supplier flat catalog.
FIG. 18 is a flow diagram illustrating the steps executed by an application server and database server for building and accessing a requisition catalog.
FIG. 19 is a diagram illustrating a user profile.
FIG. 20 is a diagram illustrating a Notes agent for building an HTML page from a DB 2 table.
FIG. 21 is a diagram illustrating Notes agents for transferring data to an application browser session from a supplier window.
BEST MODE FOR CARRYING OUT THE INVENTION
1. Clustered Servers
In accordance with the preferred embodiment of the invention, a requisition catalog system (RCW, or Rec/Cat Web) is provided within a global web architecture (GWA) infrastructure. Such an architecture provides for the large number of clients required to assure good performance. In an exemplary embodiment, the requisition catalog application is deployed within the IBM web domain, which requires the use of GWA for clustering of W 3 and www.ibm.com web sites. This architected solution assures a scalable Req/Cat Web application.
Referring to FIG. 1, client browsers 100 are connected to a GWA infrastructure including network dispatcher 102 and domino.go, a virtual cluster of Domino servers. Network dispatcher 102 , sprays out or dispatches requests among configured servers S 1 , S 2 , S 3 in virtual server cluster 104 . Communications from cluster 104 are, in turn, dispatched (also referred to as sprayed out, distributed, proxy passed, or redirected) by network dispatcher 106 among servers S 4 , S 5 , and S 6 in Domino cluster 112 . While three servers are illustrated as configured in each of clusters 104 and 112 , each cluster configuration may be scaled to any number of servers. External objects 108 , which can be stored on a distributed file system (.dfs), include graphic files, Java files, HTML images, net.data macros, and other nsf files external to Domino, and in particular include configuration file proxy statements 110 . In this instance, external objects 108 are stored on a.dfs and exist only once, so it is not necessary to replicate all of the external objects to each of the servers S 4 -S 6 . External objects 108 , served in a.dfs are graphic files, Java files, anything that would live outside of the server files (also referred to nsf files) S 4 -S 6 , including HTML images and net.data macros. These are part of the code implementing the Req/Cat Web application of the preferred embodiment of the invention, but are not part of Domino code, and are primarily for the GUI. By storing them outside of cluster servers 112 , performance is improved.
In order to avoid potential bottlenecks on the clustered Domino servers 112 and in order to store a larger amount of data than is quickly searchable in Domino, a relational database 129 , such as the IBM DB 2 database, is used to store configuration data. Data is written by the clustered servers 112 by the end user, or by batched programs stored on application server 114 that are receiving data from back-end systems 116 .
Referring to FIG. 2, in accordance with the invention, a proxy pass is used with both domino.go cluster 104 and Domino cluster 112 . In accordance with a proxy pass, when a URL 120 is passed to network dispatcher 106 , the NP processes that out and sprays it to any one of the configured servers'. Spray means to distribute or map a URL 120 to any one of these configured servers S 1 -S 3 , S 4 -S 6 , which is the effect of mapping, as is represented by line 126 , URL 120 to any of S 4 , S 5 , S 6 in cluster 112 . Examples of URLs include <w 3 . ibm.com/*>, <www.ibm.com/*>, and <w 3 . ibm.com/transform/reqcat/?opendatabase rccreate>.
In accordance with the invention, a unique architecture for a requisition catalog system includes a hybrid application using external objects 108 in a distributed file system off of the domino.go cluster 104 that works with network dispatcher 106 and the proxy pass capability 110 to redirect traffic to the Domino cluster 112 .
These servers S 4 -S 6 are mirror images: each has same .nsf files. Periodically, these servers replicate back and forth so that information is contained in all of them. Data is kept consistent.
In operation, when a client comes in through browser 100 , his request can be directed to any domino.go server S 1 -S 3 that determines the mapping of the URL request and what type of function is needed (displaying of images or code execution on S 1 -S 3 , or connecting to an.nsf server S 4 -S 6 to display user data).
.nsf servers S 4 -S 6 then feed requests to the application server 114 , which in this embodiment is a backend Req/Cat Web (RCW) server to which all data gets replicated and where the bridges and agents run. Data gets replicated out to other back-end servers (DB 2 , MVS, SAP) 116 as needed. A bridge is an application that transfers data from one server to another server. An agent is an application that runs scheduled or by request to do some processing of data.
In an exemplary embodiment, Domino.go, or virtual server cluster, 104 is part of the GWA infrastructure. Any w 3 . ibm.com or www.ibm.com must go through a domino.go cluster 104 . In accordance with the present invention a proxy out to the Domino cluster 112 is also provided. The purpose of this is to improve scalability and performance. Proxy statements 110 are used to ensure that the proper pieces of the application are invoked as appropriate, depending upon what the end user is doing. These statements are a mapping through a configuration file of URL 120 to any clustered server 112 .
Referring to FIG. 3, a specific exemplary embodiment of the invention includes client browser 100 connected to network dispatcher (URL redirect) 102 , which is connected to GWA shared GO cluster (W 3 -l.IBM.COM) 104 . Cluster 104 is connected to external objects including an open buying on the Internet (OBI) server and a distributed file system (DFS) 118 , to dedicated DB 2 server 129 , and to network dispatcher (proxy) 106 . Dispatcher 106 is connected tbo dedicated Domino “end user” cluster 112 . Cluster 112 iis connected to Blue Pages database 121 (an internal personnel database), dedicated DB 2 server 129 , dedicated Domino “application” server 114 , and other Notes databases 119 , including Skills Matching (an application for contracting technical services), AMNF (an application for identifying nonmanager requisition approvers), and public address book (PAB, for user login and authentication). Application server 114 is connected to FormWave 125 (an application that does approval form routing), PRISM/Copics 123 (which are requisition feeder systems on MVS and AS/ 400 ), SAP 382 (an ERP, or enterprise resource planning system, including an accounting application having an accounts payable function), dedicated content staging server 127 where an administration Notes client 128 runs, and dedicated DB 2 server 129 . The content staging server is used to update both nsf and DB 2 configuration data, and is also connected to server 129 .
The architecture of FIG. 3 presents a complex, scalable global procurement application (referred to as Req/Cat Web)implemented within Global Web Architecture (GWA). Req/Cat Web allows customers to generate on-line, general procurement requisitions. Customers interfacing client browser 100 can search through vendor catalogs to select items and fill in order information. Submitted requisitions are routed through an approval process using FormWave 125 . Requisitions that have been approved are sent to a back-end system (SAP) 382 , where a purchase order is cut and billing occurs. Customers can monitor their requisition status, as the back end sends status updates to the application 114 .
Technologies utilized in building Req/Cat Web include the following: Domino.Go 104 provides a proxy passing function and caching facility. Lotus Notes/Domino is used for its security and workflow capabilities. DB 2 provides rich relational database functions and data management. Net.Data is used for its catalog searching functionality. Javascript is used for GUI presentation and data verification. Req/Cat Web application code sits on DFS 118 , on the Domino cluster servers 112 , and on Domino application server 114 .
Architectural elements include load balancing, file storage, end-user front.end (which reside in the Domino cluster servers 112 ), back-end processing, external dependencies, and use of frames.
For load balancing, Req/Cat Web uses the GWA proxy pass architecture, documented in the presentation currently available on the Notes/Web application CoC Web site at http://w 3 .coc.ibm.com/coc/cocweb.nsf/Homepages/gwatrain.html.
Network dispatchers 102 , 106 are used between the client 100 and the Domino.Go cluster 104 and also between the Domino.Go cluster 104 and Domino cluster 112 to automatically balance the load of http requests among servers S 1 -S 3 and S 4 -S 6 . Configuration file (httpd.conf) 110 contains the proxy statements that are used for redirections. When a client 100 enters the url (w 3 .ibm.com/transform/reqcat) and Network dispatcher 106 redirects the client to the appropriate server 112 , the redirection is transparent to the client.
Workload is split between Domino.Go 104 and Domino 112 to improve performance.
File storage is provided by dynamic file system (.dfs, or DFS) 118 , which contains javascript files (.js), html, images, and net.data macros. Domino servers 114 contain navigation, configuration, create requisition, open requisition, requisition invoice paid, requisition archive, cost center, confirmations, and help databases. DB 2 server 129 contains tables including: confirmations, user profiles, zip codes, accounting data, commodity configuration data, buyer information, routing, and catalogs.
An end-user front end for Req/Cat Web uses Domino authentication to permit login to the application. The client uses his Lotus Notes ID and pre-set http password to “authenticate”. When a client logs in at browser 100 , the Domino servers 112 (S 4 -S 6 ) are configured to check the name and password in public address book 119 , which is a designated server within GNA. In a further exemplary embodiment, secure login function may be provided through the implementation of digital certificates. Data is retrieved from DB 2 129 using LC:LSX calls via Notes agents, or Net.Data. Net.Data is used for a catalog searching and drill-down function. Java APIs are used for information retrieval from BluePages 121 .
As much processing as possible is performed asynchronously on the back-end, application server 114 . Bridge jobs are scheduled on two levels: system level (CRON) and notes level (Agents). Agents run periodically, say hourly, to process requisitions and send them to SAP 382 . Other agents are scheduled off-peak, where ever possible.
External dependencies include FormWave for form approval routing, BluePages for personal data for user profile creation and approver changes, interfaces to Open Buying on the Internet (OBI) server and skill matching applications, and SAP for receiving requisitions for purchase order (PO) creation and processing. Information returned by SAP to Req/Cat Web includes requisition status, PO/RFS status, PO history, negative confirmations, currency codes, and configuration information.
By using frames, a large majority of preprocessing can be performed dynamically, on the client, reducing the number of trips back and forth to the server. This is a tremendous boost to performance. The web screen described hereafter is not he result of a Notes form, but rather of a dynamically generated HTML/javascript code produced by a displayReqHeader( ) function. This function dynamically writes html and javascript code into the content frame of the application. The javascript function is coded in a displayreq.js file stored on the filesystem and loaded into a jsCode frame by a source (<script src=′./js/ displayreq.js 40 >) command in a jscode.html file at the time when the initial frameset is loading. A displayReqHeader( ) function is called from several places in the application to redisplay the requisition information in the content frame. This screen is called any time a WebReq Lotus Notes form is opened by an OpenForm command for a new requisition, or by an OpenDocument command when an existing document is opened. OpenForm occurs when the displayReqHeader( ) javascript function is called as the last part of an OnLoad event coded in the HTML-Attributes property of the WebReq form. Any time an existing document is opened that was saved with Form-WebReq, the OnLoad event causes the displayReqHeader( ) javascript to be run to OpenDocument. Any time a content frame has been loaded with some other page during the processing of a requisition, and the user performs an action to return to the requisition in process, the displyReqHeader( ) javascript function is called directly. This form reads the information stored in reData frame and dynamically fills the content frame with this screen.
Referring to FIGS. 4 and 5, as will be more fully described hereafter, a screen display includes header frame 470 , navigation frame 472 , footer frame 474 , temporary data frame 476 , request data frame 478 , and content frame 480 . The tempData frame 476 is used as a temporary holder for information, and to direct calls dynamically, while keeping the current data in the screen, and making the return data available to the application.
Table 1 shows, for the exemplary embodiment of FIG. 3, the software loaded on each of the servers used for the Req/Cat Web application.
TABLE 1
SERVERS AND SOFTWARE
Server Description
Software
Domino.Go Servers S1-S3
AIX 4.3.2
Domino Go 4.6.2.6 with Denial
of Service Fix
Net.Data 2.0.8
DB2 CAE 5.2
DFS Client
Java Runtime 1.1.6
Domino End-User Servers S4-S6
AIX 4.3.2
Domino 4.6.4
DB2 CAE 5.2
Java Runtime 1.1.6
Domino Application Server 114
AIX 4.3.2
Domino Go 4.6.2.6 with Denial
of Service Fix
DB2 CAE 5.2
Java Runtime 1.1.6
Mercator 1.4.2 with Svc Pack 3
Hith Test API
Lotus VIM
C++ 3.6.4
UDB Server 129
AIX 4.3.2
UDB 5.2
Java Runtime 1.1.6
Content Staging Server 127
AIX 4.3.2
Domino 4.6.4
DB2 CAE 5.2
Java Runtime 1.1.6
2. Front End
The Req/Cat Web front end provides several validation routines, including ZIP code validation, catalog search criteria, and chart of account validation. In the architecture of FIGS. 1 and 3, various programs, including ZIP code validation, catalog search and chart of account validation routines reside in application server 114 , and the data tables, including the chart of accounts, reside in the relational database 129 .
ZIP code validation is provided to assure that the tax department is provided the information needed implement the correct tax rules on purchase orders in SAP 382 .
Chart of accounts validation includes the mapping of commodity codes to account codes. This is done to insure that all general ledger accounts associated with commodities are correct, and within this to insure that a description from SAP 382 is available for use by a customer to select correct general ledger (GL) account when doing financial validation on a requisition.
Referring to FIG. 6, for ZIP code validation, when a purchaser access RCW, a user profile 130 is accessed. Profile 130 includes many defaults, one of which is delivery information (defaulted to all line items of requisition). One of the fields in profile 130 is ZIP code. When the purchaser enters his ZIP code, RCW searches ZIP code database 134 , a database for ZIP codes which is fed periodically, say nightly, from the enterprise tax system 136 . This same validation routine continues by creating a requisition 132 with item options, including deliver to information with a zip code field. The requester can change the deliver to information, 132 , but any time it is changed, the ZIP code is checked against ZIP code database 134 . Whereas previously, customer input of ZIP code was accepted without checking. By this invention, ZIP code validation is performed at the front end by a java or SQL program call to db 2 database 134 . Responsive to entry of ZIP code on a requisition or to the changing of delivery information which includes ZIP code on a requisition line item, the ZIP code is validated against a database of valid ZIP codes. In an alternative embodiment, the ZIP code database is refreshed from a trusted source, and the entered or changed ZIP code is checked for valid match with respect to state and city.
A create requisition request goes to catalog search, which used to search by part number or description. Previously, this was a very limited search to just the catalogs. A search argument of %pen% was not a very crisp search for the customer. In order to improve the catalog search, in accordance with the present invention, searches may be conducted against a longer description and files up to 255 characters. Screen down searches are provided for sub-commodity. Wild card searches used to require %, but now assumes a wild card search in all cases. Searches are also provided against subcommodity. As a result, catalog searches now reference short description, long description, and catalog sub-commodity. A database catalog includes part number, short description, long description, oem part number, commodity code. Newly added is subcommodity.
Referring to FIGS. 7 and 9, the method of the preferred embodiment of the invention is described for managing a chart of accounts 140 . When creating a commodity list, which includes expense, capital, and resale accounts 142 , commodities descriptions 180 are pushed to the correct commodity group. The resulting chart of accounts 140 is available from SAP 382 . Previously an administrator had input a chart of accounts. Now, a company administrator, for example, may select from commodity accounts 142 the expense field, which results in drop-down display of a valid chart of accounts 144 from SAP chart of accounts 140 with account numbers 148 and commodity descriptions 146 . The company administrator may then select from that valid chart of accounts 144 the correct commodity to push to company/commodity document 150 .
Referring to FIG. 8, the process for a requester to create requisition is set forth. By way of example, a requester creates a requisition by doing in step 154 a search for “supplies”, which will bring to him in step 156 a display presenting commodity W 14 , and thence in step 158 to a catalog (for example, a Staples catalog) which includes commodities (pens, erasers, calendars), from which the requester can create several line items. Upon selecting “proceed to accounting”, the requester is presented a financial summary 160 including commodity code w 14 pens for line item 1 , w 14 erasers for line item 2 , and w 14 for line item 3 calendars. The user may then request display of financial worksheet 162 . In this window 162 , the requester will see a title 164 expense, which can be changed, for example, by toggling to other categories, such as balance sheet. Selecting G/L account 166 may drop down a list showing several account codes 168 and related descriptions 170 , depending upon what the company administrator has pushed to the commodity document 150 from which financial worksheet 162 is derived. Previously, a requester was provided in worksheet 162 one account code choice without description. By this invention, the requester is provided correct general ledger account codes and descriptions, resulting in less miscodes, more correct ledger entries, and correct SAP account codes. This improved general ledger account selection process avoids back end processing to correct erroneous entries.
Thus, in accordance with a preferred embodiment of the invention, a method is provided for creating a valid chart of accounts from which an administrator 184 can facilitate and enable a requisitioner to select a valid general ledger account. First, there is push from an enterprise (erp) system a chart of accounts 140 with descriptions to a req/cat system database. The administrator selects from req/cat system database valid accounts with descriptions for a given commodity and purchase time period, and then pushes the selected account/description tuple to the company commodity groups, thus completing the setup of the commodity documents 150 to be used in the requisition creation process. A company commodity document 150 created by administrator 184 may include for each commodity code under each company, commodity code 152 , which is a very broad catagory, short description 190 , long description 191 (from procurement organization 182 ), key words 192 , approvers 193 , financial information 194 (including purchase type 198 , and general ledger account 199 ), route-to buyer 195 (by plant association), preferred supplier 196 (which associates the commodity code to a catalog 158 ), and special handling code 197 (with drop list including, for example, skills matching, obi, administrative services)—all used to drive the customer to the correct commodity.
To create a requisition, a user searches against commodities and catalogs in commodity description documents 150 , which may be Notes documents or DB 2 records, and creates one or more line items. These searches may be done by catalog and non-catalog, and driven based on descriptions entered by requester. A hierarchy of families may be provided as an alternative search approach. The requisitioner initiates a proceed to accounting process, which displays line items which may be selected by requisitioner; and then displays a financial worksheet created by a Java agent with fields which need to be selected or populated by the requisitioner from the company commodity document, based on purchase type, and which presents valid general ledger accounts numbers and descriptions to the requisitioner.
3. Back End
Referring to FIG. 12, in a large enterprise, the requisition catalog requires a very large database. In accordance with the preferred embodiment of the invention, such a large data repository is provided by the using the IBM DB 2 relational database 210 . Other possible databases include Oracle, Sybase, and MSSQL.
Lotus Notes databases are built upon an object model and classes: databases, views, and documents are classes used to access Notes data. But, these classes are set to be final and not extendible, and a Req/Cat Web database must be extendible.
Consequently, referring to FIG. 12, in accordance with an embodiment of the present invention, DB 2 access routines 208 are provided for accessing DB 2 data 210 . The Req/Cat Web application executes Lotus code, with access controlled on the code, and data obtained from and written to relational database 210 .
Normally, Notes saves all data as documents. There is a save method provided for that purpose. In accordance with a preferred embodiment of the invention, the Notes save method is intercepted and stopped, and execution passed to Req/Cat Web code for saving data to DB 2 . In the same way, execution of a Notes open method is intercepted and stopped, and then Req/Cat Web code executed to pull information in from DB 2 .
Lotus Notes provides for web applications, and supports methods called webqueryopenagent, and webquerysaveagent. Notes also provides a saveoptions parameter. Setting saveoptions to zero tells Notes not to save a document.
In accordance with the preferred embodiment of the invention, saveoptions is set to zero, and webquerysaveagent used to save data in DB 2 . The webquerysaveagent is written in Lotus Script, and calls Lotus Script extensions and also can also call its own APIs 200 , 202 , including the database api's 208 . At this point, Req/Cat Web haves full control, and can save one or many tables, can explode the data model and write many tables.
On the other side, instead of editing an existing document as is done with Notes, Req/Cat Web executes createnewdocument. As the document opens, Lotus Notes gives the query webqueryopenagent, and this is also written in Lotus Script, which has access to data base api's 202 , where data from many database 210 tables may be read to construct a Lotus document from DB 2 .
This configuration involves some naming standards and a hierarchy of interfaces. By way of example, database access routines are, by convention, data application programming interfaces (DAPI) 208 . These are routines for accessing data 210 outside of the Req/Cat Web application. Referring to FIG. 10, a hierarchy of application program interfaces (APIs) includes core API's 200 containing everything necessary to connect to database 210 . Next in hierarchy, to access specific data, are database API's (DAPI) 208 , which interface to a single piece of data (such as company or employee information.) Below these rest the business logic code 204 .
In a programming environment, the top of pyramid represents the work of a core DB 2 programmer. Below him are those people who use core DB 2 API's and write, for example, DAPI's 208 to access individual DB 2 tables within database 210 , for example API's for countries. These core APIs 200 , therefore, include a GET method, and update, insert, and delete routines. Third level 204 represents the application programmer who only needs to use these methods (ie, company dapi: IBM US) in their business logic 204 applications, including ability to update, for example.
Referring to FIG. 11, this same pyramid is used to implement graphical APIs 206 on the user interface 212 , business APIs 207 on the business logic 204 interface, and database APIs 208 on the database 210 interface. This illustrates that duties of programers can be separated, so that everyone need not know the complexities of the entire system. That is, some developers work on data manipulation, others on the user interface, and still others on business logic. The application developer need not know the names of the actual database, tables, or fields, or even how to access them. This also enables a DB 2 administrator to alter a table, and only affect the one DAPI developer that wrote the specific table DAPI 202 . All code is one routine, so changes to the database need only affect one piece of logic.
Referring to FIG. 13, an example of this API implementation is illustrated. CoreDB 2 220 is the core API 200 to connect to DB 2 210 . It contains two classes, configuration class DB 2 Config 222 and base class DB 2 Base 224 .
Calling DB 2 config 222 determines database name 230 , user identifier 231 , and password 232 —information that the database requires to establish a valid connection, and is passed to DAPI 208 for making that connection. (Without this method, user IDs and passwords would have to be hard coded in the application.)
DB 2 Base 224 is extended by the DAPI 208 programmer for each DAPI 202 instance that is needed. It contains methods 240 , 241 for connecting to and disconnecting from the database, a method 242 for defining the number of rows to return at a time, a method 243 for getting the next group of records, methods for reads 244 , inserts 245 , updates 246 , and deletes 247 , commit 248 and rollback 249 options, and a flag 250 to determine if all data has been retrieved.
DAPIUserProfile 226 is a class for retrieving or updating information about an employee. It extends DB 2 Base 224 so the application 204 developer would not have to write the logic to access DB 2 210 , but could concentrate on the information about the employee. The DAPI 202 developer would need to know about the employee table (table and field names, for example) and would implement methods for selecting and displaying data. In an exemplary embodiment, DAPIUserProfile class methods include the following:
260 selectEmployeeByEmplID (employeeID, companyCode, countrycode)
261 selectEmployeeByWebID (employeeWebID)
262 selectEmployeeBothWays (employeeID, companyCode, countryCode, employeeWebID)
263 selectEmployeeByName (lastName, firstName)
264 insertEmployee (columnNames, DB 2 ColumnValues)
265 updateEmployeeByEmpID (employeeID, employeeCompanyCode, employeeCountryCode, UpdateNameValues. . .)
266 updateEmployeeByWebID (employeeWebID, UpdateNameValues, UpdateByUserID)
267 deleteEmployeeByEmpID(employeeID,companyCode, countryCode,UpdateByUserID)
268 deleteEmployeeByWebID(employeeWebID, UpdateByUserID)
269 deleteEmployeesWhere(Condition, UpdateByUserID)
270 clearTable( )
Once the data is selected, a few of the properties that are available for a given employee include empWebID, empLastName, empFirstName, empIntPhoneNum, empExtPhoneNum, empEmailID, empID, empCompanyCode,empCountryCode, and empCountryName.
An application 204 like the human resources (HR) application would then need to read HR data and insert it into the employee table if the employee did not exist, or update it if something changed, or delete it if the employee no longer exists. This application developer would then only have to know the methods and properties of the userprofile class 226 in order to write the application. An example of such an application is set forth in Table 2, with reference to the steps of FIG. 14 . This table sets forth the HR load routine, a batch program to read HR data from a flat file and insert it into the DB 2 user profile table.
TABLE 2
EXAMPLE APPLICATION
‘in the following step, instantiate a DB2 config
object, and call it db2; the database name 230, etc.,
is determined by instantiating the db2 config object,
as defined by the core programmers'
272:
Dim db2 As New DB2Config(session)
‘the database information is known, and can be passed
to the employee profile.'
274:
Print “The target DB2 database alias is “&
db2.getDB2DatabaseName ())
‘All that must be done is to pass the DB2 class to the
userProfile.’
276:
Dim eps As New userProfile (db2)
‘Delete everything from the employee table to start the
bridge.’
278:
I headerDivision = “” Then
Call eps.clearTable()
Else
Call eps.deleteEmployeesWhere(“COGRP_CD= “”
&headerDivision & “”)
End If
280:
For count = 2 To records-1
‘Read the next record and make sure that it can be
loaded without problems’
If ReadInputFile(inputFileNum, count, userid, al, cl
eps, cci) Then
Call eps.insertEmployee (DB2ColumnNames,
BuildDB2ColumnValues ())
db2kAdditions = db2Additions+1
End If
Next . . .
In Table 3, a pseudo code example of use of the webquerysaveagent process is illustrated.
TABLE 3
WEQUERYSAVEAGENT EXAMPLE
Dimension db2 As New DB2Config(session)
Print “The target DB2 database alias is “&
db2.getDB2DatabaseName ())
Dimension eps As New userProfile(db2)
execute process 260 to selectemployee by employee id
if employee does not exist, then
execute process 264 to insert employee
else if employee changed, then
execute process 265 to update employee
else (employee not changed) information to user
“employee not changed”
no save
endif
In the example of Table 3, an application programmer 204 is using a dapi written by programmers 202 .
In this manner, the relational database 210 is used as the data source, instead of a Notes database, in a way that hides the complexities of DB 2 database programming. That is, in a fashion to similar Notes programming—the idea is to allow a Notes programmer to use a familiar looking class 226 to load and save data.
4. Catalog Administration
In accordance with the preferred embodiment of the invention, a requisition catalog administration function provides control, audit, and publishing procedures for flat files received from suppliers.
Referring to FIG. 15, a system architecture for implementing catalog administration includes a requester browser 410 , a buyer browser 412 , with net.data connections 391 and 393 to a dedicated DB 2 server and DB 2 database 390 having a staging table 392 and a production table 394 through network dispatcher 102 and Go cluster 104 . Go cluster 104 is also connected through network dispatcher 106 and Domino cluster 112 to Domino application server 114 . A buyer 412 accesses staging table 392 via net.data connection 391 , and a requester 410 accesses the production 394 table via net.data connection 393 . This connection 391 , 393 is implemented as a single path, and the requester and buyer provided different levels of authority to access different tables 392 , 394 in DB 2 390 over that same path. Buyer 412 can change selected fields in the staging table 392 and can update production table 394 from staging table 392 . Requester 410 can only view (not change) the production table 394 . The buyer at browser 412 is controlled by a GUI which contains access control list (ACL) control on fields, and edit authority for catalog access.
Referring to FIG. 16, this architecture further includes a catalog flat file 314 , an application program 384 within application server 114 , catalog administration function 386 , Req/Cat Web function 388 , and WEB communications 396 and 398 connecting a catalog administration function with ACL control 400 and requester 402 to database 390 .
In operation, catalog flat file 314 is received by application server 114 through firewall 380 via EDI and loaded into DB 2 database 390 by application program 384 . Catalog administration function 386 specific users 400 audit control over certain fields in staging table 392 , and publishes the catalog data to the live, or production, system 394 . Function 386 presents to buyer 400 a staging table 392 with a GUI front end, with selected fields enable and other fields not enabled to be personalized.
Catalog file 314 is a flat file containing catalog items in a column delimited format specified to supplier 300 by the enterprise.
Application server 114 manages database 390 containing staging table 392 and production table 394 . A catalog file 314 comes to application server 114 , which includes a program 384 for moving data from that flat file to staging table 392 .
A buyer at terminal 400 accesses the staging table 392 on the web 396 . He views catalog items and enters transactions with action button which transfers information from staging table 392 to production table 394 . Production table 394 is referenced by req cat web 388 , and staging table 392 is referenced by the catalog administration function 386 operated by the buyer 400 . Typically, a buyer is member of procurement organization with responsibility for negotiating deals with suppliers. A requester 402 accesses production table 394 over web 398 to create and submit a requisition to SAP 382 .
In accordance with the preferred embodiment of the invention, control over what buyer 400 can change is provided by a GUI in a process which loads a catalog 392 from a supplier into a production system 394 .
Catalog files 314 come in from suppliers in an enterprise defined standard format, and the access to fields in that format is hard coded into the catalog administration function 386 . Application server program 384 has error checking functions to assure validity of a catalog 314 from a supplier 300 . Buyer 400 accesses staging table 392 through a catalog administration function 386 which has hard coded into it the access controls on the various fields in the catalog format. Production table 394 , which is accessed by the requester 402 , is updated periodically (upon buyer actuation) from the staging table 392 .
Implementation of the invention involves several code procedures: there is a program 384 which loads a file 314 that is received via EDI into a table 392 in DB 2 . There are routines 388 which allow a buyer 400 to browse certain catalogs in the staging table 392 and change certain fields while being inhibited from changing others. And there are the routines 386 which take the approved catalog and migrate the data from the staging DB 2 table 392 to the production DB 2 table 394 .
Referring to FIG. 17, a preferred embodiment of these processes are presented. In supplier system 300 , supplier source data 310 is extracted and reformatted in step 312 to create catalog flat file 314 in the format specified by the enterprise. In step 316 that flat file is transmitted to the enterprise 302 , as is represented by line 305 , where it is accepted in step 320 into the enterprise EDI mailbox 322 . In step 324 , the data in the flat file in mailbox 322 is reformatted and put into generation data group (GDG) 328 , a location for saving more than one file, so as to retain the last N iterations, and a archive entry made to processing log 326 . In step 330 , a delivery component executes to send data from GDG 328 to application server 114 , as is represented by line 303 , in the form of catalog flat file 340 . In step 342 , a delivery component receives the flat file and, as is represented by line 347 , starts job scripts including MASSLOAD for reading the flat file and loading staging table 392 , and as represented by line 345 alerts the buyer 352 . As is represented by lines 311 , 313 and 315 , respectively, MASSLOAD 344 accesses database server 306 procedures catalog_s 360 , product_s 362 , and Req/Cat Web 364 , and makes an archival entry to processing log 346 .
Catalog_S 360 is the staging table 392 for the catalog profile, which provides for each catalog the supplier name, the start and end dates of catalog validity, the currency, and so forth.
Product_S 362 is the staging table 392 that holds the catalog parts, a listing by part number of price, description, and so forth.
Req/Cat Web validate procedure 364 is a Java stored procedure for performing the initial validation of data received in flat file 340 .
Front end 370 is a GUT used by the buyer, for example to update the catalog 366 .
In operation, validation procedure 364 validates the format and identifies catalog changes to product s 362 , logging those changes in file 332 . It then checks a flag in catalog 366 , and if the flag is on invokes procedure 350 provided catalog_s 360 does not indicate any critical errors. Validate and load procedure 350 then moves the contents of product_s staging table 362 into the appropriate production table 368 , writing any errors to processing log 348 . (In the event that procedure 364 does not call procedure 350 , then buyer 352 intervention is required via GUI 370 .) After procedure 364 completes execution, it may either stop, or if catalog 366 has a flag set on and catalog_s staging table 360 indicates no critical errors, then procedure 364 will invoke validation and migration procedure 350 . After validate procedure 364 completes, it has written to prod_message_s file 332 , and the buyer may use GUI 370 to read messages from file 332 and make any desired changes to staging table 362 . They buyer may also choose to reject the catalog and, via step 354 , contact the supplier to restart the process. This occurs if there is an error in the unit prices, which is an example of information in the catalog which a buyer is not authorized to change on his own.
After the buyer has used GUI 370 to make the values in staging table 362 acceptable, he sets the flag in staging table 360 which allows migration procedure 350 to run to move data from staging table 362 into production table 368 , a relational database, such as Net Commerce (NC) or IBM DB 2 .
5. Role Table GUI
A preferred embodiment of the invention provides through use of a role table in DB 2 database 129 (FIG. 3, or 390 in FIG. 16) very flexible access to DB 2 tables without requiring involvement by a database administrator (DBA) to issue grants against the tables, thus bypassing the problem caused by Notes agents all coming from the same user (the Notes server ID).
Everything in Lotus Notes, even code, is in documents which require access control list (ACL) controls on access. Consequently, the preferred embodiment of the invention uses Notes ACLs to access code. However, when accessing data, a role table 420 (see FIG. 19) is used to build roles and permissions, and an object model is provided to generically access data from database 210 , thus extending Notes to access a non-Notes data source 210 . In order to configure DB 2 to work in a Notes application environment, a single sign off is provided after getting through Notes code ACLs. This does not involve use of any of DB 2 's role tables and grants, but rather a single web ID 434 known to the Notes code to access the DB 2 data.
Referring to FIG. 19, role table 420 includes for each of a plurality of user WEB ID's 422 , the associated role 424 and level 426 of granularity at which the user is associated with the role. Example: for a role 424 of country administrator, the level 426 is the country id, and user with web ID 422 of 02 can update contract profiles for that country.
Any person at a browser 100 attempting to access a row in a DB 2 table 390 must pass the role table 420 check. Further, for accessing a supplier table in DB 2 390 , anyone can view the list of suppliers in the application that applies to the requesters country, but only the country administrator can update them.
User 422 identifies a user profile 430 , which specifies the user name 432 , web identifier 434 , charge information 436 , including country, company, work location) and delivery information 438 (including street, office, and building).
Thus, in accordance with the preferred embodiment of the invention, the web ID 434 for the browser user is used to control access to the Notes databases and to the DB 2 databases. The Notes databases have code and documents which the user must access (including contract profiles, cost center profiles) and also tables in the DB 2 database. A user must access both Notes databases and DB 2 databases, and access to all of these databases is controlled based on the user web ID 434 through the use of role table 420 .
In order to make and use the preferred embodiment of the invention, an implementer and user would do the following:
1. Determine what levels of granularity are relevant to the application. (For example, the company that the user belongs to, the country, etc.)
2. Populate the DB 2 table 420 with Web IDs 434 and associated roles 424 and levels 426 .
3. Write procedures to locate a user 422 in table 420 and pull out associated roles 424 and levels 426 .
4. Provide code routines or functions using these procedures which are authorized for execution by users with specific roles and levels.
Code using these routines would then compare the roles and levels to the specific role and level that is required based on the function. For example, a user could be defined as a country administrator for France and a company administrator for a small company in the U.S. A routine that updates accounting information for the small company would not care about the country-level authority, so would look in role table 420 for company administrator role 424 for this user web ID 422 . The level 426 of the role 424 would further restrict this user 422 from updating the accounting information for any company in the US other than the one corresponding to the level 426 to which he is assigned.
The invention allows a person's access to DB 2 tables to be limited by the contents of a second db 2 table rather than the grants issued by the DBA. In the Notes environment of the preferred embodiment of the invention, the ID which is actually granted the authority to the table is the Notes Server machine since the server accessing the db 2 tables is the Notes server. Since the user web id is once removed, this provides a mechanism for applying a level of authority to the user to then apply to the db 2 table. That mechanism is the role table.
Table 4 lists and describes the Req/Cat Web tables of the preferred embodiment of the invention.
TABLE 4
REC/CAT WEB ADMINISTRATION TABLES
ADMINIS-
TRATION
FUNCTION
TABLE
DESCRIPTION
Access
REQCAT.TROLE_AUTHORITY
Maps a user to
Authority
a role and the
qualifier for
that role (i.e.,
what level)
REQCAT.TROLE_CODE
Defines the
list of valid
roles - Global
Admin, Country
Admin, etc
Account
REQCAT.TACCOUNT_PROFILE
Holds account
numbers
REQCAT.TLACCOUNT_PROFILE
codes to be
validated against
REQCAT.TACCT_PROF_DETAIL
Provides details
REQCAT.TLACCT_PROF_DETAIL
about the
account codes
REQCAT.TACCT_VALIDATION1
Holds account
codes to be
validated against,
as well as what
type of validation
is occurring (i.e.,
against BMS,
Remind,
Project numbers,
Customer
numbers, etc)
REQCAT.TACCT_VALID_TYPE
Defines the
list of
validation types
REQCAT.TCOMP_COA
Defines the GL
REQCAT.TLCOMP_COA
account numbers
that are
available for each
company code,
and provides a
translated
description
Approver
REQCAT.TAPPROVER_ASSIGN
Links an approver
routing
to a type and
a code (i.e.
I/T 0001)
REQCAT.TAPPROVER_PROFILE
Defines the
approver's name,
Web ID, etc.
REQCAT.TAPPRV_TYPE_PROF
Defines the types
of approvers
available to
the application
(capital, financial,
I/T, chemical,
safety, tax)
REQCAT.TCATLG_APPROVAL
Allows a catalog
administrator
to flag a catalog
item as requiring
chemical or
safety approval in
specific locations.
For example,
toner is not
considered a
chemical item
except in
Vermont,
because of special
environmental
laws in that state.
Buyer
REQCAT.TBUYER_PROFILE
Defines the
routing
owner of a buyer
code and contact
information
REQCAT.TBUYER_ROUTING
Links a buyer to a
commodity
REQCAT.TBUYER_SUPPLIER
Links a buyer to a
supplier
Catalog
RC.CATALOG
Defines the
profiles
characteristics
of a catalog -
supplier,
expiration date,
currency, etc.
RC.CATPLREL
Defines the
plants which are
allowed to
access this
catalog
Commodity
NC.CATEGORY
Defines the global
families
list of commodity
groupings
Commodity
RC.COMMOCODE
Defines the global
codes
list of commodi-
ties and
identifies which
family each
belongs to
Company
RC.COMMCOMP
Not all
commodities
commodities may
be valid for all
companies. This
table identifies
which commodity
codes the
company wants
to use.
REQCAT.TCOMMCOMP_BUYER
Some commodi-
ties require that
the user select
a buyer from a
predefined list.
This is the
predefined list.
REQCAT.TCOMM_COMP_COA
This associates
GL account
codes with the
commodity code.
REQCAT.TCOMM_WLOC_RCV
This defines for
which work
locations this
commodity is
‘receivable’. This
flag is forwarded
to SAP for further
use in receiving
locations
RC.SUBCOMMODITY
Some commodi-
ties are too broad
and the need
exists for sub-
dividing the
goods under
this commodity
so that different
suppliers and
different purchase
processes can
be used.
RC.SUPPSUBCOMM
This links a
supplier to a
specific
subcommodity.
Companies
RC.COMPANY
Associates SAP
company codes
with associated
country. For
example, IBM US
contains
three company
codes for IBM,
Lotus, and Tivoli.
Countries
RC.COUNTRY
Holds the list of
ISO country
codes, i.e., US,
FR, DE, etc
Company
REQCAT.TCOMPGRP_TYP_PROF
Defines the
groups
list of valid
grouping
types, such as
ACCOUNT,
UPROF
REQCAT.TCOMPGRP_PROFILE
Defines the list of
group names and
links them to
their types,
such as IBMUS -
ACCOUNT and
IBMUS - UPROF
REQCAT.TCOMPANY_GROUPING
Lists the company
codes that belong
to the specified
grouping
Plants
RC.PLANT
Associates plant
codes with
company and
country.
A company
can have
many plants, a
plant may belong
to only one
company.
Suppliers
RC.SUPPLIER
Defines the
characteristics
of a supplier -
name, code,
contact
information,
location
RC.SUPPCOMP
Defines which
company codes
may reference
this supplier for
purchasing
Work
REQCAT.TWORK_LOCATION
Associates work
locations
REQCAT.TLWORK_LOCATION
locations with
plant, company,
and country.
A plant can have
one or more work
locations, a work
location may
belong to only
one plant.
REQCAT.
For those work
TWORKLOC_DELTOADDR
locations which
have a predefined
CDC (Chemical
Delivery Center)
address
User
REQCAT.TEMPLOYEE_PROFILE
Holds employee
profiles
information
Catalog
see FIG. 18, DB2 NCF
Hold part
parts
tables 368
information,
category/
subcategory
information, etc.
6. Relational DB Agents
In accordance with a preferred embodiment of the invention, in a Notes/DB 2 hybrid environment, a Notes agent reads data from a DB 2 table, and then dynamically populates that data to an HTML page. In this manner, an the existing infrastructure (including Notes, Domino Go, and DB 2 ) is used to combine HTML and Java script web presentation with DB 2 data.
Referring to FIG. 20, Notes agents 440 are used as intermediaries. Each such agent 440 reads DB 2 tables 390 , collects data using SQL select statements, and builds web page 442 dynamically, writing out the Java script and HTML to present the page on a Web browser, such as Web browser 100 . The results of the DB 2 searches also helps to determine which HTML needs to be written, something which standard HTML cannot handle. Thus, conditional logic may be used.
A plurality of agents 440 are provided. The premise is the same in all: figure out who is asking, and then tailor what is shown by what they are authorized to see. The example of Table YY is the supplier profile agent.
This process makes use of the Notes connection function lsx:lc. This Lotus Script connection is a built in API for connectivity to relational databases. The lsx:lc connector is a Lotus provided API which allows connection to DB 2 .
For example, to display a list of supplier profiles, two DB 2 tables 390 must be read: one provides a list of suppliers and the other is role table 420 (FIG. 19 ). When role table 420 is read, the code tests the users ability to edit (country admin for country of supplier), and may display the web page differently depending thereon. A dynamic feature of the invention is that straight text may be displayed, or with text with hyperlinks to open a supplier profile, as an example.
To make and use this preferred embodiment of the invention, the following is done:
1. Use the Lotus Script lsx:lc connector connect to DB 2 .
2. Depending on the DB 2 table being read and the functions required, write functions to Create, Read, Update, and Delete with respect to the DB 2 table.
3. Write the HTML to display the page, and then have the Notes agent 440 Print these HTML commands to the browser so that they appear in a meaningful presentation to the end user.
4. Use conditional logic to change the look of the page 442 based on the results of the DB 2 390 lookups.
Inputs to the method of this embodiment of the invention include the DB 2 table to be read or updated, and the output includes HTML conditionally generated based on results of the DB 2 table reads.
The HTML page being populated may, for example, provide a list of suppliers. Such pages may also be used in the requisition or configuration area of the application, displaying commodity codes, suppliers, and so forth.
TABLE 5
EXAMPLE AGENT 440
This agent is invoked from the administration tab for ‘supplier’. It is
presenting the user with a view of suppliers that have been configured
on the system. Based on the access authority of the user, this list
will be presented either as just text, for the general user, or as
hotlinks for an administrator to then open an individual supplier
profile and update it.
Sub Initialize
//setting up variables
Dim src As New LCConnection (“db2”)
Dim fldLst As New LCFieldList(100)
Dim suppname As LCField
Dim suppcode As LCField
Dim InfoView As AllInfoView
Dim session As New NotesSession
Dim doc As NotesDocument
Dim sqlQueryString As String
Dim flag As Variant
Dim admin As Integer
Admin=True
Dim lclsxSession As LCSession
Dim supplierdb As notesdatabase
Dim configview As notesview
Dim configdoc As notesdocument
Dim lookuptype As String
On Error Goto errHandler
Set supplierdb=session.currentdatabase
Set configview = supplierdb.getview(“APPVIEW”)
Set configdoc = configview.getfirstdocument
lookuptype = configdoc.HRFormat(0)
Set doc=session.DocumentContext
Set InfoView=New AllInfoView
//connect to DB2
InfoView. ConnectToDB2
//Query the role table for users roles and authority levels
If Not InfoView.CheckAdminPrivilegesOK (doc.CurrentuserName
(0) ) Then
Admin = False
End If
InfoView. DisconnectDB2
If (Admin = False) And (lookuptype = “DON”)Then
Print“<script>alert(‘You are not authorized to view Supplier
documents Please contact your procurement administrator if you have
questions’);”
Print “history.go (−3) </script>”
Exit Sub
End If
//Begin printing out HTML from the agent
Print “<link rel=stylesheet type=““text/css”” href=““/transform
/reqcat/css/default_styles.css””>”
Dim db2c As New db2config(session)
//Connect to DB2
src.database = db2c.getDB2DatabaseName() ‘“reqcat41”’
src.Connect
//build the SQL Query
sqlQuerystring = “select SUNAME, SUID from RC.SUPPLIER”
sqlQueryString = sqlQueryString & “order by SUNAME”
If (src.execute(sqlQueryString, fldLst) = 0) Then
Print “You do not have any supplier profiles to view.”
End
End If
Set suppname = fldLst.Lookup (“SUNAME”)
Set suppcode = fldLst.Lookup (“SUID”)
//Print more HTML
Print “<TABLE width=‘100%’ cellpadding=‘0’ cellspacing=‘0’>”
Print “<BR><TR><TD class=““banner”” bgcolor=““3366cc”” align=
““center””> Suppliers</TD></TR>”
Print “</TABLE>”
//If the user is an admin, then provide a button for adding new
suppliers
If Admin Then
Print “<form>”
Print “<input type=‘button’ name=‘mybutton’ value=‘Add
Supplier Profile’ onClick=““javascript: document.location.href=
‘./SUPPLIER?OpenForm’; ””>”
Print “</form>”
Else
Print “<BR>”
End If
Print “<table cellpadding=2 cellspacing=0 border=0>”
Print “<tr><td class=““bannersublevel”” ><B> Supplier</B></td>”
Print “</tr>”
//Toggling background color on alternate rows
flag = True
While (src.Fetch (fldLst) > 0)
If (flag) Then
Print “<tr bgcolor=#CCCCCC>”
flag = False
Else
Print “<tr bgcolor=#FFFFFF>”
flag = True
End If
//If user is an admin, then print the supplier name as a hotlink
If Admin Then
Print“<td class=““field””> <a href=./SUPPLIER?
OpenForm&“ & suppcode.text(0) & ”>“&suppname.text(0)&”</a> </td>”
Else
//otherwise just print it as text
Print“<td class=““field””>“ &suppname.text(0) &”</td>”
End If
Print“<td class=““field””>“ &suppcode.text(0) &”</td>“
Print ”</tr>”
Wend
Print “</table>”
End
errHandler:
Print “<br>” & session.currentagent.name & “ - Line # ” &Str(Erl)
& “ // Error ” & Str(Err) & “: ” & Error$
If (lclsxSession.Status <> LCSUCCESS) Then
Dim text As String
Dim extcode As Long
Dim exttext As String
Call lclsxSession.GetStatus (text, extcode, exttext)
If (lclsxSession.Status = LCFAIL_EXTERNAL)Then
Print “<br>DB2 message: ” & exttext & “ code #” &
Cstr(extcode)
Else
Print “<br>Connector message: ” & text
End If
Else
Print Error$
End If
End Sub
7. Data Transfer
In accordance with the preferred embodiment of the invention, a system and method is provided for transferring to a Req/Cat Web (RCW) application in a timely manner large quantities of data from web sites that exist outside of a a firewall, or internal applications within the firewall but outside of the Req/Cat Web application.
For the purpose of the description of this embodiment, RCW exists in a frame set in a browser. A frame set divides a screen into logical and user-friendly sections called frames. As part of security for browser 100 , Netscape and Internet Explorer (IE) establish ownership of the frames: each frame is a window under control of browser 100 . Browser 100 can open up a session in any frame desired. However, if all of the frames open on a browser are not owned by same session, then these frames cannot see the contents of each other.
Consequently, the problem is presented: if RCW needs to access an outside supplier site 300 for information to get back through one its own the frames, as soon as data is written by that other site into one of the frame at browser 100 , RCW no longer owns the frame and cannot access the information. So this aspect of the invention is concerned with data passing.
In accordance with the preferred embodiment of the invention, the supplier 300 opens a new window through normal Java script commands and writes its data into it, along with the name of the agent to run in RCW application server 114 . That new window then calls one of the RCW processes, which is able to see the data because it is not in a frame and is therefore available for RCW to access. That process causes an agent to runs (in RCW) that can see that data and write it to a frame on the RCW side, resulting in RCW owning both the data and the frame. This allows RCW to reach NOTES information, and write that information to other frames. RCW owns the data and the frame. Ownership is established in the RCW application.
Consequently, by carefully tracking and controlling the sequence of opening windows, RCW can establish the origin from which data is coming, where the data is going, and which process owns it.
Those are the high points. Review: two sites are talking to each other using an intermediate window, doing a handoff of data and of ownership of both data and frame such that when it is time to supply information to the RCW application, RCW owns the data, frame and process.
Referring to FIG. 21, a system and method are provided for data transfer from a externally owned site to an application owned frame set which operates as follows. The RCW application opens a supplier site URL in a temporary frame 456 . Upon user selection of go to supplier 451 , as is represented by step 458 , frame 456 opens the supplier window 460 as a separate browser session. Two windows are now open: the original application 450 with its window underlying, and a supplier window 460 over it with the supplier URL. The reason for doing this is that the supplier requires that the browser be full frame, not in a small frame set. The primary RCW application in window 450 is quiesced to a wait state. As is represented by steps 462 , the user can now select from window 460 items to buy, search, or whatever the supplier deems is appropriate for a user to order his data. The user then issues the command to submit the order. In step 444 , the supplier site then gathers content from order data entered at window 460 , in step 446 formats the page, and in step 448 issues a call to Req/Cat Web to open third window 464 with first agent 480 . The supplier uses an enterprise specified agent name for first agent 480 when opening third window 464 . Third window 464 is a window, but not a frame, and thus the Req/Cat Web can get access to it even though it is opened by the supplier. First agent 480 includes an html form command 488 which defines the processing to be done on the contents 466 of the form now displayed in third window 464 , and the supplier site writes into this third window 464 unique order identifying information. Once written, the browser activates the form. Once activated, it is a program in its own right, the html 488 that was written and any java script in it will execute. One of first things it does is look at the action in the form command and determine that this is the program that will run to deal with the contents of this form. That action program, or first agent 480 , is a RCW action program on the RCW server that can see contents of third window 464 because it is not in a frame, and thus ownership is not critical. In step 482 , first RCW agent 480 executes a program or process that writes the contents 466 of window 464 back into its frame set (temporary frame) 456 , and then calls second agent 484 which references Java script code 454 and, as is represented by step 486 , access Notes data on the Notes server, add content to the requisition, and issue the commands that send the order to be stored in the requisition. This is key, Req/Cat Web has used its own process 480 to write into its own window 450 , and knows who owns the data. First agent 480 process opened window 464 and writes the data to temporary frame 456 and then kicks off another process, second agent 484 , that can read that data, can read and write to all of the frames 452 in the application, can access information from Lotus notes, and write all the information into the requisition.
Window 460 is provided by a supplier site from outside the application, and possibly also outside a firewall. Window 460 is an external application that allows execution of code 462 for performing search, select, submit (call enterprise server, which may be inside firewall), and order data, including gather content 444 , formatting the page 446 , and calling RCW 448 with the first agent 480 as an action form.
Window 464 is a window opened by the supplier to include a Req/Cat Web agent, first agent 480 . First agent 480 posts document contents to temporary data frame 456 . As a variation, for skills matching, calls are made to the agents 480 , 484 with a parameter after placing the data to retrieve in a Notes database. The second agent 484 retrieves the data, can look up and add supporting data from yet another Notes database.
The key consideration here is, “who owns the frame”. The server that owns the agent that last wrote a frame owns it, and can see its content, but cannot see any other frame's contents if they were written by another server's programs or agents.
Window 464 and first agent 480 act as an intermediary. Content 466 is owned by the supplier server 300 , but the first agent 480 is owned by the Req/Cat Web server 114 . That first agent 480 then kicks off the rest of the process, passing the data and ownership to the RCW server 114 and the second agent 484 . The second agent 484 can now can access Notes data on the Notes server 112 , and issue the commands that send the order to be stored in the requisition.
8. Customiizable Side Bar
In accordance with the preferred embodiment of the invention, a customizable side bar is provided. Dynamic HTML is used by the navigator responsive to user input to change data presented at the screen without having to communicate with a remote server.
Referring to FIG. 4, navigation frame or menu bar appears, typically, on the left of a display window, to display a plurality of menu boxes, including headers 491 - 494 and items 495 - 500 . As a cursor is moved over the headers, each individual header is highlighted or some symbol 481 , 483 , 485 , 487 , respectively, rotated by, say, 45 degrees, so as to point either down or to the right, to indicate to the user the header which will, upon being clicked, toggled to either a collapsed or expanded state from its current expanded or collapsed state, respectively. As illustrated, headers 481 and 483 are in a collapsed state, and headers 485 and 487 are in an expanded state. When expanded, header 485 is expanded to show items 495 - 498 , and header 487 to show items 499 - 500 . The user may move the cursor to one of items 495 - 500 , and select the item to update the data displayed in content frame 480 .
Heretofore, when the user selects (clicks on) a menu header 491 , there is generally a pause as the request is made to the server to obtain a new page including an expanded menu bar 472 including a display of the included items. In accordance with a preferred embodiment of the invention, when server loads the window to a client, all of the information required to load the menu bar 472 is provided, including information for the expanded menu items (but not the content frame associated with them). If a menu header 485 is clicked when in the collapsed state, the menu items 496 - 498 are shown or made visible and the following menu headers and items are moved relative to the expanded menu bar. If a menu item 496 is clicked, then communication with the server is required to load the content frame 480 .
Upon initial load, all headers 491 - 494 are collapsed and all menu items are hidden. Menu headers 491 - 494 are displayed below each other with no gaps between them. Clicking on a last menu header merely shows all the menu items and moves nothing below it. Clicking on the first menu header would show all of its items and move every header and item a constant amount without changing its visibility state. (The display area 472 may be off of the window, but is available via the scroll bar 490 .) In accordance with this embodiment of the invention, the result of selecting a header 491 - 494 is an instantaneous response from the client browser either expanding or collapsing the selected header and respectively displaying or removing from display the included items.
This is done using dynamic html (dhtml), which allows creation of divisions within a document. These divisions are equivalent to tab items, menu items 495 - 500 , or headers 491 - 494 . In Netscape, these divisions are called layers. In Explorer, the layers are called divisions. These divisions can be hidden or shown, and moved relative distances on the screen. The current state of the art is to use these divisions for moving or flashing graphics, but not for business applications such as menu bars. In accordance with the present invention dhtml at the client creates subtle changes, business like, in the menu bar 472 without requiring server communications. The use of dhtml is described at developer.netscape.com.
Java script code, executable at a client for inserting, showing, moving and updating a menu bar 472 , is illustrated in Table 6.
TABLE 6
MENU BAR CODE
---- JavaScript (appNav.js) ---------
// appNav Class Constructor
-----------------------------------------------------
// This class implements a JavaScript Object intended to represent the
Navigator function appNav(menuVar) {
//methods
this.init = appNavInit;
this.sizeit = appNavSizeit;
this.toggletext = appNavToggleText;
this.isItem = appNavIsItem;
this.reverse = appNavReverse;
// properties
this.ns = document.layers;
this.ie = document.all;
this.loaded = 0;
this.whichone = 0;
this.whichgroup = 0;
if ( this.ns ) {
this.show = ‘show’;
this.hide = ‘hide’;
} else {
this.show = ‘visible’;
this.hide = ‘hidden’;
}
this.menus = menuVar;
this.max = menuVar.length;
this.images = new Array(this.max);
this.menuMove = new Array(this.max);
for (i=0;i < this.max; i++) this.menuMove[i] = 20 * (menuVar[i] −
1);
this.tabShow = [false, false, false, false, false, false, false,
false];
}
function appNavInit() {
var k=0;
if (this.loaded == 0) {
for (i=0; i < this.menuMove.length; i++) {
this.images[i] = new Array(this.menus[i]);
for (j=0; j < this.menus[i]; j++) {
this.images[i][j] = new Image();
pos = (“0”+i).slice(i>9,2) + (“0”+j).slice(j>9);
this.images[i] [j] .src = “../images/men” + pos
+“.gif”
if (this.ie) {
document.images[k].src=this.images[i] [j].src;
k++;
} else
document.layers[“D”+pos].document.images[0].src=this.images[i] [j].src;
}
}
this.loaded=1;
}
};
function appNavSizeit() {
if (this.loaded==1) {this.loaded = 0; this.init();}
};
function appNavToggleText.(z) {
if (this.loaded==1) {
this.tabShow[z] = !this.tabShow[z]
for (j=1; j<this.menus[z]; j++) {
pos = (“0”+z).slice(z>9) + (“0”+j).slice(j>9);
if (this.ie)
text = document.all(“D”+pos).style
else
text = document.layers[“D”+pos]
if (this.tabShow[z])
text.visibility = this.show;
else
text.visibility = this.hide;
}
for (i=z+1; i<this.max; i++) {
for (j=0; j<this.menus[i]; j++) {
pos = (“0”+i).slice(i>9) + (“0”+j).slice(j>9);
if (this.ie) {
text = document.all(“D”+pos).style
if (this.tabShow[z])
text.pixelTop += this.menuMove[z]
else
text.pixelTop −= this.menuMove[z]
} else {
text = document.layers[“D”+pos]
if (this.tabShow[z])
text.top += this.menuMove[z]
else
text.top −= this.menuMove[z]
}
}
}
}
};
ADVANTAGES OVER THE PRIOR ART
It is an advantage of the invention that there is provided a scalable database system in a web environment with optimal access performance characteristics for an expanding number of clients and a growing database.
It is an advantage of the invention that there is provided a system and method for enabling a requester to select the correct general ledger account when doing financial validation on a requisition.
It is an advantage of the invention that there is provided a system and method for utilizing Lotus script extensions in combination with a relational database to provide high capacity storage without performance degradation.
It is an advantage of the invention that there is provided a system and method for enabling a buyer a means for editing catalog content before externalizing it to production for access by requesters.
It is an advantage of the invention that there is provided a system and method for providing very flexible access to DB 2 tables without requiring database administrator (DBA) involvement to issue grants against the tables, and bypassing the problem caused by Notes agents all coming from the same user (the Notes server ID).
It is an advantage of the invention that there is provided a system and method utilizing an existing infrastructure including Lotus Notes, Domino Go, and DB 2 to combine HTML and Java script web presentation with DB 2 data.
It is an advantage of the invention that there is provided a system and method for enabling transfer of data from a supplier site to a RCW application which does not entail frame spoofing.
It is an advantage of the invention that there is provided a system and method for dramatically increasing the speed of operation of a navigation frame of a GUI.
ALTERNATIVE EMBODIMENTS
It will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. In particular, it is within the scope of the invention to provide a computer program product or program element, or a program storage or memory device such as a solid or fluid transmission medium, magnetic or optical wire, tape or disc, or the like, for storing signals readable by a machine, for controlling the operation of a computer according to the method of the invention and/or to structure its components in accordance with the system of the invention.
Further, each step of the method may be executed on any general computer, such as an IBM System 390 , AS/ 400 , PC or the like and pursuant to one or more, or a part of one or more, program elements, modules or objects generated from any programming language, such as C++, Java, Pl/ 1 , Fortran or the like. And still further, each said step, or a file or object or the like implementing each said step, may be executed by special purpose hardware or a circuit module designed for that purpose.
Accordingly, the scope of protection of this invention is limited only by the following claims and their equivalents.
|
A hybird Notes/DB 2 environment provides a requisition catalog on the Web. Client browsers are connected to a GWA infrastructure including a first network dispatcher and a virtual cluster of Domino.Go servers. The network dispatcher sprays out browser requests among configured .nsf servers in virtual server cluster. Communications from this virtual server cluster are, in turn, dispatched by a second network dispatcher servers in a Domino cluster. External objects, primarily for a GUI, are served in a .dfs and include graphic files, Java files, HTML images and net.data macros. The catalog is built from supplier provided flat files. A front end is provided for business logic and validation, as also is a relation database backend. HTML forms are populated using relational database agents. A role table is used for controlling access both to Notes code and DB 2 data. Large amounts of data is quickly transferred using an intermediate agent and window.
| 8
|
BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] This invention relates generally to implantable tissue stimulating apparatus of the type having a pulse generator and a medical lead for delivering electrical stimulation to target tissue, and more particularly to a tool to be used in facilitating the surgical implantation of a medical lead into a patient's body.
[0003] II. Discussion of the Prior Art
[0004] In implanting medical devices, such as pacemakers or pacemakers/defibrillators, a transvenous lead placement approach has found wide acceptance. Using the Seldinger technique, the right or left cephalic vein or the axillary vein is located and punctured with a relatively long, large-bore needle. A guidewire is then typically passed through the needle into the selected vein. The needle is then removed from the guidewire and replaced with an introducer incorporating a hemostasis valve to stem blood flow. Once the introducer is in place, the medical lead is forced through the hemostasis valve, the introducer's shaft, and thence, through the selected vein and ultimately into a selected chamber of the heart.
[0005] An introducer that has found rather wide spread acceptance is the SafeSheath® manufactured and sold by Pressure Products of Rancho Palo Verdes, Calif. It incorporates a tear-away sheath having a break-away hemostasis valve assembly affixed to a proximal end of the sheath. The hemostasis valve assembly comprises a molded plastic housing containing an elastomeric disk having a self-closing aperture formed through its thickness dimension. The SafeSheath also includes a side entry port located distally of the housing containing the hemostasis valve whereby fluids containing an anti-coagulant may be infused through the lumen of the sheath and into the selected vein.
[0006] Once the introducer is installed, a medical lead having one or more electrode surfaces at its distal end is passed through the hemostasis valve of the introducer and thence, through its sheath until the electrodes are positioned at a desired site within the heart. Once the distal end of the lead is appropriately placed, the introducer may be removed from the lead by splitting the break-away hemostasis valve assembly and the sheath.
[0007] While introducers of the type described can be used with a variety of pacemaker/defibrillator leads, there are certain lead designs that can be damaged as the distal end portion bearing the electrodes is forced through the self-closing aperture of the hemostatic valve. The shocking electrodes on defibrillator leads are often in the form of an uninsulated wire coil supported by the lead's plastic body. As a lead of this type is forced through the hemostasis valve of an introducer, the excessive frictional forces tend to displace the turns of the coil so that they are no longer appropriately spaced.
[0008] Other leads with which the SafeSheath introducer is incompatible are those in which a fabric covering is placed over the coil electrodes of defibrillator leads to inhibit tissue ingrowth into the coils of the shocking electrode. Because of the porosity of the fabric, electrical shocking currents readily pass through to surrounding tissue with very low impedance. However, it is found that the SafeSheath introducer incorporates a silicon oil as a lubricant on its hemostasis valve member and as such a fabric covered electrode of the lead is forced through the self-closing aperture, the silicon oil wipes off onto the fabric covering that tends to plug the pores in the fabric which adversely impacts the lead's electrical performance. Then, too, when attempting to pass this lead through the valve, frictional forces tend to displace the fabric covering, in effect, peeling it back. Another drawback of the hemostatic valve's direct engagement with the medical lead being implanted is that tactile feedback through the lead to the physician's fingers is severely dampened.
[0009] From the foregoing discussion, those skilled in the art will appreciate that a need exists for a lead insertion tool that will obviate the cited drawbacks of state-of-the-art lead introducers incorporating a hemostasis valve. The present invention provides such a device.
SUMMARY OF THE INVENTION
[0010] The present invention comprises a lead insertion tool adapted for use with a lead introducer having an elastomeric hemostasis valve with a self-closing aperture. The tool comprises a tubular sheath having a relatively thin wall with at least one longitudinal groove formed inwardly thereof to facilitate rupture of the sheath along the groove. The lumen of the tubular sheath is sized to receive a medical lead therethrough with a predetermined clearance fit. A tool dilator that has a generally rigid shaft is insertable through the lumen of the tubular sheath and when so inserted renders the sheath sufficiently rigid to allow insertion of the sheath and dilator through the self-closing aperture of the lead introducer. Once inserted through the aperture, the tool dilator is removed from the tubular sheath and the distal end of the medical lead is then advanced through the lumen of the sheath which holds the aperture in the hemostasis valve open while shielding the lead from exposure to contaminating silicon oil and minimizing friction that distorts the lead electrodes and/or fabric covering. Once the lead has made its way past the hemostasis valve, provision is made for rupturing the tubular sheath of the insertion tool along its length, allowing it to be pealed off from the lead body.
[0011] In accordance with a further feature of the invention, the tool dilator may be dispensed with when the lead insertion tool is assembled onto the distal end portion of the lead to be installed and then the lead with the tubular sheath surrounding its distal end are passed through the hemostasis valve as a unit.
DESCRIPTION OF THE DRAWINGS
[0012] The foregoing features and objects, as well as others, will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which:
[0013] [0013]FIG. 1 is an exploded side elevational view of the lead insertion tool comprising a preferred embodiment of the present invention;
[0014] [0014]FIG. 2 is an enlarged view of the hub portion of a lead introducer showing the hemostasis valve;
[0015] [0015]FIG. 3 is a top plan view of the tubular sheath component shown in FIG. 1; and
[0016] [0016]FIG. 4 is a greatly enlarged, cut-away view of the lead insertion tool when used to pass a distal end of a medical lead through a hemostasis valve of an introducer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the device and associated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof and words of similar import.
[0018] Referring initially to FIG. 1, there is indicated generally by numeral 10 a conventional introducer set of a type used in implanting medical leads for an implantable pacemaker or pacemaker defibrillator. It is seen to comprise a flexible, tubular sheath 12 having a proximal end 14 and a distal end 16 and with a lumen extending therebetween. Completing the set is a dilator (not shown). Affixed to the proximal end 14 of the sheath 12 is a hub member 18 that is molded from a suitable plastic. Contained within the hub 18 is an elastomeric disk 20 (FIG. 2) having a self-closing aperture 22 formed through the thickness dimension thereof. The hub 18 further includes a side port 24 having a bore, not shown, that is in fluid communication with the lumen of the sheath 12 . A length of tubing 26 may be connected to the side port 24 and affixed to the other end of the tubing 26 is a stop cock member 28 . This stop cock is also a conventional component and has provision for controlling the flow of a flushing fluid, such as saline or saline mixed with an anti-coagulant to inhibit plugging or clogging of the sheath 12 by blood.
[0019] For illustrative purposes only, the introducer set 10 may comprise a SafeSheath introducer of Pressure Products, Inc. or another introducer set incorporating a hemostatic valve.
[0020] In accordance with a first embodiment of the invention, the lead insertion tool consists of a two-piece assembly including a tubular sheath member 30 and a tool dilator 32 . The sheath member 30 has a relatively thin-walled, extruded plastic, tubular sheath 34 . Affixed to a proximal end 36 thereof is a hub 38 having a Luer fitting 40 on its proximal end. Wings 42 and 44 project laterally from the hub. The hub 38 has longitudinally extending grooves 46 formed inwardly from the outer surface thereof at diametrically located positions. These grooves are not so deep as to intersect with the lumen 48 formed through the hub (FIG. 3). The tubular sheath portion 34 also includes diametrically opposed score lines, as at 50 , that are vertically aligned with the grooves 46 and 48 .
[0021] With the described arrangement, a medical professional is able to split the sheath member 30 into two halves along the grooves 46 and score lines 50 by applying a downward bending force to the wing members 42 and 44 .
[0022] The lumen 48 of the device is sized to receive the distal end portion of a medical lead 52 through it.
[0023] In that the wall thickness of the sheath 34 is only about 0.010 in., it may lack sufficient rigidity to allow it to be passed through the self-closing aperture 22 of the hemostatic valve member 20 of the introducer 10 . There is, therefore, provided the tool dilator 32 having a generally rigid shaft 54 which, when inserted through the lumen 48 of the tubular sheath member 30 , provides sufficient support to permit the sheath 34 containing the shaft 54 to pass through the self-closing aperture 22 . Affixed to the proximal end 56 of the shaft 54 is a Luer lock member 58 for cooperating with the Luer fitting 40 of the sheath member 30 . A swivel 60 is rotationally joined to an upper surface of the Luer lock 58 . The swivel 60 includes a central bore that tapers to a lesser diameter of a bore formed longitudinally through the generally rigid shaft 54 . The diameter of the bore extending through the shaft 54 is of a size to accommodate a conventional guidewire that can be inserted through the tool dilator 32 , the sheath member 30 and the introducer set 10 if desired.
[0024] In use, the person involved with implanting the lead 52 may pass a guidewire (not shown) through a hollow trocar used to pierce the selected vein. Leaving the guidewire in place, the needle may then be stripped off from the guidewire and replaced with the introducer set 10 which would be passed over the guidewire and into the puncture wound until the distal end 16 of the introducer set 10 is located within the lumen of the selected vein in which the lead 52 is to be routed in reaching the heart. Once the introducer is in place, its dilator is withdrawn and the combination of the sheath member 30 and the tool dilator 54 that are now locked together by engagement of the Luer lock 58 with the Luer fitting 40 is used to penetrate through the self-closing aperture 22 of the hemostasis valve 20 contained within the hub 18 of the introducer. The wings 42 prevent the sheath member 30 from passing completely through the hemostasis valve and into the blood vessel. Next, the tool dilator 32 is removed from the sheath member 30 and, at this point, a cap (not shown) may be screwed onto the Luer fitting 40 to maintain hemostasis. When the physician is ready to insert the medical lead and advance it into the heart, the cap is removed and the distal end of the lead 52 is inserted through the lumen 48 which is now holding the self-closing aperture open. In that the elastomeric, self-closing hemostasis valve is not acting on the lead, tactile feedback is maintained. Once the lead has been advanced into the heart, the sheath member 30 can be slipped rearward in the proximal direction until the sheath 34 is free of the hub 18 of the introducer. Now, the attending physician may apply finger pressure to the wings 42 and 44 to thereby split the hub 38 along the grooves 46 and 48 and tear the thin-walled sheath 34 along its score line 50 . Thus, the sheath member 30 can be completely removed from the lead.
[0025] The introducer 10 employed is also designed to be split and pealed free from the lead.
[0026] In accordance with an alternate embodiment, the tool dilator 32 can be dispensed with and only the sheath member 30 employed to aid in breaching the self-closing aperture 22 of the hemostatic valve member 20 . Here, after the introducer 10 has been placed and its dilator removed, the distal end of the lead 52 may be inserted directly through the bore of the hub 30 and into the lumen of the thin-walled tube 34 , but not so far as to project out the distal end of the tubular sheath 34 . The combination of the lead 52 filling the lumen of the thin-walled sheath 34 can render the sheath 34 sufficiently rigid to allow it to be passed through the hemostasis valve. Once the assembly has been mated with the hub 18 of the introducer, the lead 52 can be further advanced through the sheath 12 of the introducer and the selected vein into the heart. Again, because the sheath member 30 is splittable, it can readily be removed from the lead once the lead has been positioned.
[0027] It should also be mentioned that the length of the tubular sheath 34 is such that when inserted into the hub 18 of the introducer, it will pass through the self-closing aperture 22 but not extend so far as to occlude or block the flow of fluid that may be injected through the side port 24 , via the stop cock 28 and the tubing 26 .
[0028] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
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A tool for protecting a cardiac stimulating lead from damage upon passing through a hemostasis valve of a vascular introducer in the course of an implantation procedure comprises a splittable, peal-away sheath that is rendered sufficiently rigid by a tool dilator or placement of the lead body within the sheath so that the combination can be forced through a self-closing aperture formed through the hemostatic valve member. The use of the tubular sheath in breaching the self-closing aperture shields the lead electrodes and any covering that may be present from becoming distorted as well as from contamination by silicon oil commonly found in vascular introducers having a hemostasis valve.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional patent application claims priority from and the benefit of the filing date of co-pending Provisional Patent Application Ser. No. 61/656,679 filed Jun. 7, 2012 titled “ALTERNATIVE FUEL COMBUSTION ENGINE ENHANCER” by Michael W. Archer in accordance with 35 U.S.C. §§119(e) and 120.
TECHNICAL FIELD
[0002] This invention relates to hydrolysis units for combustion engines. More specifically, the invention relates to open loop hydrolysis units for internal combustion engines.
BACKGROUND OF THE INVENTION
[0003] The use of hydrogen and/or oxygen gas as a fuel component for internal combustion engines is well known. In such applications, the production of hydrogen and/or oxygen gas for combustion purposes is often produced through electrolysis of water. As is well known to those of ordinary skill in the art, pure water can be broken down into hydrogen and oxygen gas (H 2 , O 1 ) by placing electrodes in water and providing a voltage potential across the electrodes. Hydrogen gas will accumulate around the cathode while oxygen gas will accumulate around the anode, according to the well known formulas:
[0000] Cathode: 2H 2 O(1)+2e − →H 2 (g)+2OH − (aq); and
[0000] Anode: 2H 2 O(1)→O 2 (g)+4H + (aq)+4e − .
[0004] The overall reaction for both electrodes when the formulas are combined and reduced leads to the well known formula:
[0000] 2H 2 O(1)→2H 2 (g)+O 2 (g)
[0005] In the context of internal combustion engines, electrolyzed hydrogen gas or oxygen gas or both can be and have been applied to an internal combustion engine. Systems of this type generally constitute closed cycle/closed loop systems, or open cycle/open loop systems.
[0006] Published U.S. Patent Application Nos. US2002/0117125 A1 and 0074680 A1 by McMaster, et al. describe a typical closed loop or closed cycle hydrogen or oxygen gas fuel system for use with an internal combustion engine. In the applications filed by McMaster, et al., hydrogen gas and oxygen gas are separated through electrolysis and then stored in accumulators through one-way check valves. The oxygen and hydrogen gas are then introduced to an internal combustion engine and the exhaust is passed through a condenser which recycles the condensed water back into the electrolytic chamber. Thus, water, in general is not lost to the atmosphere and the system is essentially closed loop.
[0007] Published U.S. Patent Application US2011/0290201 A1 by Owens discloses a hydrogen supplemental system for on-demand hydrogen generation for internal combustion engines which operates in an open loop mode. In the system described by Owens, oxygen is vented to the atmosphere while hydrogen gas is directed to the engine air intake for combustion purposes.
[0008] Mosher, et al. describe in U.S. Pat. No. 6,257,175 an oxygen and hydrogen generator apparatus for internal combustion engines in which oxygen from an electrolytic cell is fed into the intake manifold of the internal combustion engine, while the hydrogen gas is fed directly into the pre-ignition combustion chambers. Water in the system described by Mosher, et al. used by the generator apparatus is replenished from a reservoir. The water used in the generator apparatus is accordingly kept at a desired level.
[0009] Thus, a variety of systems are contemplated in the prior art which generate either oxygen or hydrogen gas or both for combustion in an internal combustion engine in either open or closed loop modes. Nevertheless, such prior art devices suffer from various practical problems including excess heating and high corrosion, particularly where a catalyst or electrolyte is introduced into the water prior to electrolysis. Some prior art devices extract hydrogen and oxygen gas from water by force which produces excess heat and steam, other units have very high power consumptions as they are adapted to produce all or substantially all of the combustion gasses needed to operate the internal combustion engine. Other prior art devices have a short life because of corrosion or have complex electrical systems to make their units operate properly.
[0010] Therefore a need exists to provide an alternative fuel combustion engine enhancer that significantly lowers emissions on combustion engines, is safe for the environment, provides an increase in power in a combustion engine and that provides a balanced production of hydrogen oxygen gas.
BRIEF SUMMARY OF THE INVENTION
[0011] It is therefore an object of the present invention to provide for an alternative fuel combustion engine enhancer for the vast improvement of combustion engines through a greener environment with lowered emissions, decreased fuel consumption, increased engine life and increased power.
[0012] Another object is to provide an Alternative Fuel Combustion Engine Enhancer that significantly lowers emissions on internal combustion engines.
[0013] Another object is to provide an Alternative Fuel Combustion Engine Enhancer that is safe for the environment.
[0014] Another object is to provide an Alternative Fuel Combustion Engine Enhancer that provides a significant increase in power (varies with different types of engines).
[0015] Another object is to provide an Alternative Fuel Combustion Engine Enhancer that A PADLE has a balanced production of hydrogen and oxygen.
[0016] Another object is to provide an Alternative Fuel Combustion Engine Enhancer that produces very pure hydrogen that is extremely powerful and clean. When properly installed, A PADLE should yield between 10% and 50% improvement in fuel economy depending on the engine size and the “A PADLE” size.
[0017] The present invention relates generally to, Archer's A PADLE (Archer's petroleum alternative duel life energy) and more specifically it relates to an alternative fuel combustion engine enhancer for the vast improvement of combustion engines through a greener environment with lowered emissions, decreased fuel consumption, increased engine life and increased power.
[0018] The invention achieves the above objects, and other objects and advantages which will become apparent from the description which follows, by providing an open loop, catalyst free pure water hydrolysis unit for use with a combustion engine. The hydrolysis unit includes a plurality of concentric, spaced apart tubular cathodes having continuous side walls and upper and lower ends forming closed surfaces. The cathodes are electrically interconnected to one another and to a direct current power source for generating hydrogen gas. The unit also includes a plurality of anodes in the form of elongated, conductive rods having upper and lower ends including interconnections between the anodes as well as to the direct current source for generating oxygen gas. Upper and lower substantially nonconductive end caps having concentric circular grooves for receipt of the cylindrical cathodes as well as a plurality of receptacles for receiving the upper and lower ends of the anodes are provided. Preferably, the end caps define a plurality of apertures for permitting convention flow of water from the lower to the upper end caps and return flow across the anodes and cathodes for cooling purposes and to dislodge gas generated in and around the electrodes. The unit is preferably connected to the intake of an internal combustion engine to combust and recombine the hydrogen and oxygen gas for generating power, reducing emissions and to render a clean air and more stochastically correct combustion cycle.
[0019] In a preferred embodiment of the invention, the anode and cathode of the unit are connected to a conventional automotive battery through an ignition switch and an under—on/off switch through a conventional relay. The unit is preferably contained in a container having a water manifold and a water reservoir to replenish water which is depleted from the unit through the hydrolysis process. The electrical system may also be connected in series with an oil pressure switch connected to the internal combustion engine such that upon failure of the engine either due to a decrease in oil pressure or through normal operation when the engine is switched off the unit will not generate any combustible gasses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0021] FIG. 1 is a side elevational view of an electrolysis unit of the present invention.
[0022] FIG. 2 is a sectional perspective view of the electrolysis unit of the present invention illustrating the anodes, cathodes and end caps of the electrolysis unit. This is the view of three copper pipes and the end pieces.
[0023] FIG. 3 is an upper perspective view of an end cap of the present invention.
[0024] FIG. 4 is a schematic representation of fluid flow in the hydrolysis unit of the present invention.
[0025] FIG. 5 is a schematic representation of the present invention installed in an internal combustion engine environment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] An alternative fuel combustion engine enhancer hydrolysis unit in accordance with the principles of the invention is generally indicated at reference numeral 10 in the various Figures of the attached drawings wherein numbered elements in the figures correspond to like numbered elements herein.
[0027] With reference to FIGS. 1 and 2 , the unit 10 generally produces free hydrogen and oxygen gas through a hydrogen oxygen outlet 12 which may be used as combustion gasses in an internal combustion engine or the like as will be described herein below in greater detail. The unit 10 has upper and lower end caps 14 , 16 preferably manufactured from a nonconductive polymer such as machined acrylic. FIG. 2 illustrates the unit 10 in section so as to illustrate the end caps 14 , 16 and the concentrically arranged, tubular cathodes 18 and elongated rod-like anodes 20 which are received in the end caps 14 , 16 . The lower end cap 16 is best seen in FIG. 3 in which concentric grooves are machined in the end caps 14 , 16 for receipt of upper and lower ends, respectively of the cathode side walls. The end caps further define receptacles into which upper and lower ends of the anodes are also received such that the end caps 14 , 16 , anodes 20 and cathodes 18 together form a structurally cohesive unit. The end caps 14 , 16 further define fluid apertures 24 through which water undergoing electrolysis (not shown) may flow vertically so as to cool the unit through convention currents set up in the water inside the unit as well as off-gassing of oxygen and hydrogen which contribute to the fluid dynamics of the unit. The three sets of concentric, tubular cathodes 18 are provided with insulated conductors 29 , 30 and 31 for connecting the cathodes in a conventional manner to a source of direct current, such as an automotive battery as will be described herein below. The anode rods 20 are also similarly electrically interconnected by wires (not shown) to the opposite polarity of the direct current power supply.
[0028] FIG. 4 illustrates that the lower end cap 16 includes the cathodes 18 , anodes 20 , apertures 24 all received or defined by the lower end cap 16 . Those of ordinary skill in the art will appreciate that the upper end cap is identical to the lower end cap.
[0029] When assembled as shown in FIG. 2 , the unit 10 permits fluid as best see in FIG. 4 to circulate in a vertical pattern about the electrodes. When the unit 10 is fully assembled, upper and lower manifolds 36 , 38 permit water to flow vertically along the sides of the outermost cathodes 18 and down through the inside of the innermost cathode through the fluid apertures 24 due to convection caused by temperature differentials and the vertical orientation of the unit 10 . A drain 40 may be provided at a bottom end of the lower manifold 38 to empty the unit such as for removal from a vehicle and servicing.
[0030] FIG. 5 illustrates the hydrolysis unit 10 installed in an automotive environment including an engine of the internal combustion type having an exhaust manifold 52 and an intake manifold 54 connected to a throttle body 56 . The throttle bottle 56 is connected by a gas conduit 58 to the outlet 12 of the unit 10 so that the generated hydrogen and oxygen gasses may be introduced to the engine through the intake manifold 54 for combustion along with any fossil fuel/air mixture normally used by the engine. The unit 10 is preferably received in a fluid impermeable container 60 connected to a water manifold 62 at an upper end thereof to be in fluid communication with a water tank 64 and valve 66 which maintains the water in the manifold 62 at a desired level so that the hydrolysis unit 10 does not run dry as gas is produced. As previously stated, the cathodes and anodes of the unit 10 may be connected to an automotive battery 68 to power the unit when the engine 50 is running. To this end, the cathode is interconnected through a conventional automotive relay 70 to an under—on/off switch 72 and the automotive ignition switch 74 as well as an oil pressure sensing switch 76 all in series such that the electrolysis unit 10 only generates combustible gasses when the engine is running.
A. Overview
[0031] Turning now descriptively to the specific elements described above, in which similar reference numerals denote similar elements throughout the several views, the Figures illustrate Copper Pipes (cathodes 18 ), Stainless Steel Rods (anodes 20 ), Machined Acrylic End Caps ( 14 , 16 ), Copper Wire ( 29 , 30 , 31 ), a Water Supply ( 64 ) and a Wiring Harness ( 80 ).
B. Copper Pipes
[0032] There are three copper pipes 18 . The exterior copper pipe is 7¾″ long by 3″ diameter and 0.065″ wall thickness. The two interior copper pipes are 7¼″ long and 2″ and 1″ diameter respectively. They also are 0.065″ wall thickness. The function is to create hydrogen.
[0033] One, 1″ diameter copper pipe by 0.065″ thick.
[0034] One, 2″ diameter copper pipe by 0.065″ thick.
[0035] One, 3″ diameter copper pipe by 0.065″ thick.
[0036] All three copper pipes can be lengthened or shortened to adjust hydrogen output, and the number of copper pipes can be increased or decreased according to need. The copper pipes can be round, flat, or shaped according to need.
C. Stainless Steel Rods
[0037] There are twenty stainless steel rods 20 . Nineteen rods are the same length and one rod is 4″ longer. The stainless is 316L. The diameter is 0.125″. All twenty rods create oxygen. The 4″ longer rod also provides a platform for a positive connection to the other nineteen rods and connects to the A PADLE control circuit (A PADLE wiring harness 80 ).
[0038] The rods can be lengthened or shortened to coincide with various size cores, and the number of rods may vary according to need.
D. Machined Acrylic End Caps
[0039] The two acrylic end caps 14 , 16 are 2 ⅞″ in diameter by ½″ thick and machined to hold the two internal copper pipes 18 and stainless steel rods 26 in position.
[0040] The acrylic end caps can be increased or decreased in diameter to match the core if the core size is changed.
E. Copper Wire
[0041] There are three copper wires 29 , 30 , 31 . The shielded copper wire is 10″ long and 12-gauge, soldered to each of the three copper pipes with lead-free silver solder. This copper wire makes a negative connection to the power source.
[0042] The three shielded copper wires are 2″ long and 12-gauge, soldered to the three copper pipes with lead-free silver solder. This copper wire makes a negative connection to the power source.
[0043] The copper wire may be lengthened or shortened depending on the needs of the core.
F. Water Supply
[0044] The water supply reservoir 64 can be from different containers of different sizes. G. Wiring Harness
[0045] The wiring harness 80 (see FIG. 5 ) provides the connection from the A PADLE to the various points on the vehicle.
[0046] The wiring harness connects the A PADLE unit 10 to the engine 50 .
[0047] The wiring harness can be lengthened or shortened depending on the engine application.
H. Connections of Main Elements and Sub-Elements of Invention
[0048] The copper pipes 18 are connected by the copper wires 29 , 30 , 31 and then to the battery 68 negative.
[0049] The stainless steel rods 20 are connected by the stainless steel wire (not shown) which connects to the A PADLE control circuit relay 70 .
I. Alternative Embodiments of Invention
[0050] The A PADLE can be lengthened or shortened to alter hydrogen output.
J. Operation of Preferred Embodiment
[0051] When A PADLE unit 10 is active, the oxygen and hydrogen bubbles produced by electrolysis in the water rise to the surface through the centers of the copper pipes 18 . A small amount of heat is produced. When the oxygen and. hydrogen bubbles reach the top surface, they are drawn into the engine through the air intake 54 to the engine 50 .
[0052] The inside pipe 18 flow of warm water forces the cooler water on the outside of the pipe to descend causing the flow of water. See FIG. 4 . An absence of water only stops the production of hydrogen and has no other effect on the gasoline, diesel, or propane engine. The standard water supply holds variable amounts of water. The A PADLE unit 10 is easily serviced by replacing the water in the A PADLE reservoir 64 . Two or more units 10 would be used for large trucks and large equipment. The life expectancy before main element service or replacement is expected to be 100k-plus consecutive miles.
[0053] Hydrogen and oxygen gas are not stored. The success of the A PADLE unit 10 is the result of the unique flow of H 2 O from which the gas is gradually extracted from the H 2 O for combustion in the engine. A PADLE unit 10 will not work properly with the use of salt water or sea water or with any additive catalyst in the water.
[0054] What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention in which all terms are meant in their broadest, reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.
[0055] Thus, those of ordinary skill in the art will conceive of other alternate embodiments of the invention upon reviewing this disclosure. Thus, the invention is not to be limited to the above description, but is to be determined in scope by the claims which follow.
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An alternative fuel combustion engine enhancer for the vast improvement of combustion engines through a greener environment with lowered emissions, decreased fuel consumption, increased engine life and increased power. The alternative fuel combustion engine enhancer generally includes Copper Pipes, Stainless Steel Rods, Stainless Steel Wire, Silver Solder, Machined Acrylic End Caps, Copper Wire, a Water Supply, a Wiring Harness, and a Control Panel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communications system, and particularly but not exclusively to channel management procedure for use when transmitting low rate data over a TDMA communications system such as a digital cordless telephone system for example DECT (Digital European Cordless Telephone). By low rate data is meant a data rate which is a binary submultiple of the data rate for one TDMA time slot.
2. Description of the Related Art
FIGS. 1 and 2 of the accompanying drawings illustrate respectively an example of a digital cordless telephone system and the channel and message structure in accordance with the DECT protocol.
The illustrated digital cordless telephone system comprises a plurality of primary or base stations PS of which four, PS1, PS2, PS3 and PS4, are shown. Each of the primary stations is connected by way of a respective wideband landline link 10, 11, 12 and 13, capable of carrying data at a rate of say 1.152 Mbits/sec. to cordless telephone system controllers 14 and 15. The system control terminals 14 and 15 are, in the illustrated embodiment, connected to the PSTN which is constituted by an ISDN (Integrated Services Digital Network) link.
The system further comprises a large plurality of secondary stations SS some of which, SS1, SS2, SS4 and SS5, are hand portable and are used for digital time division duplex speech communication only. Others, for example SS3 and SS6, are data terminals which also are capable of duplex data communication. Duplex communication between the secondary stations within an area covered by a system control terminals and/or the PSTN is by way of radio through the primary stations PS, which act as relay stations. Accordingly the primary and secondary stations each comprise a radio transmitter and receiver.
Referring to FIG. 2, the illustrated system has ten radio channels, hereinafter referred to as frequency channels C1 to C10, each capable of carrying digitised speech or data at 1.152 Mbits/sec. The adjacent frequency channel separation is 1.728 Hz. Each frequency channel is divided in the time domain into 10 ms frames. Each frame is divided into 24 time slots (or physical channels) of which the first twelve F1 to F12 are allocated for transmission in a forward direction, that is from a primary station to a secondary station, and the second twelve R1 to R12 are allocated for transmission in the reverse direction. The forward and reverse time slots are twirled, that is, the correspondingly numbered forward and reverse time slots, for example F4, R4, comprise a twin which hereinafter will be referred to as a duplex voice channel. In setting-up a call between a primary and a secondary station, a duplex voice channel is assigned to the transaction. The assignment of the duplex voice channel in any of the frequency channels C1 to C10 is by the method of dynamic channel allocation, whereby a secondary station, taking account of its radio environment, negotiates with the primary station for access to the best duplex voice channel currently available.
The general structure of a message is also shown in FIG. 2. The message structure comprises two bytes of preamble 16, two bytes of a synchronisation sequence 18, six bytes of signalling data plus 2 bytes for cyclic redundancy check (CRC) 20 and forty bytes of digitised speech or data plus a four bit CRC (repeated twice) 22. The digitisation rate and data rate is 32 kbits/sec. Both the primary and secondary stations include a buffer to compress the 32 kbits/sec. data to bursts of data at 1.152 Mbits/sec. so that it is suitable for transmission.
The basic protocol for a transmission which is to be initiated by a secondary station SS is for it to listen to all the forward physical channels in each of the frequency channels C1 to C10 and ascertain which forward physical channels are busy and idle and the relative signal quality in these forward physical channels, and from the information derived the secondary station determines what it believes is the best duplex voice channel and transmits in the reverse physical channel of that duplex voice channel to a particular primary station PS. The signalling details 20 in the message together with the details 22 in the initial transmission are decoded and passed to the system controller 14 or 15 which sets-up the fixed network connection. The primary station confirms that the particular physical channel has been assigned to the transaction.
In the forward direction, the primary stations send paging messages to the addressed secondary stations in say every sixteenth frame. Such an arrangement enables the secondary stations to "sleep" during at least the intervening fifteen frames thereby economising on power. An addressed secondary station in response to a paging request addressed to it will, unless a duplex voice channel has been assigned, transmit in the reverse time slot (or physical channel) of the best duplex voice channel. As a general rule the system protocol will give priority to speech over data.
It is not unusual for a secondary station SS3 or SS6 to generate batches of data at rates in excess of 32 kbits/sec. Also, if the system is to be able to utilise an ISDN fixed wired link, then unless buffering is used, the system must be able to supply data at a rate of 144 kbits/sec. One way of doing this is for a system control terminal to allocate additional duplex voice channels to the transaction so that data packets can be transmitted in parallel.
There is also the alternative situation of a data terminal generating data at a rate which is a binary submultiple of 32 kbits/sec, for example 16 kbits/sec, and 8 kbits/sec, 4 kbits/sec. or 2 kbits/sec, such a terminal will hereinafter referred to as a low rate data terminal. If a physical channel in each frame is assigned to a transmission from a low rate data terminal this would be an inefficient use of the radio spectrum. It has been proposed to split a physical channel into 2 or more partial physical channels and assign each partial physical channel to a respective low rate data terminal. However in a situation of the signals from two or more low rate data terminals being multiplexed on one physical channel, and one of the data terminals completing its transaction before another low rate data terminal sharing the same physical channel, then the system control terminal either has to find another low rate data terminal having a data rate not exceeding the capacity of the released partial physical channel and multiplex that with the transaction from the subsisting low rate data terminal on that physical channel or pad the released partial physical channel with idle bits in order to maintain bit synchronisation.
SUMMARY OF THE INVENTION
It is an object of the present invention to transmit low bit rate data signals in a spectrum efficient manner.
According to a first aspect of the present invention there is provided a communications system comprising a system control terminal for controlling the operation of the system, at least one primary station coupled to the system control terminal and at least one low rate data terminal, said at least one primary station and at least one low rate data terminal having means for establishing a data link between them, said data link comprising a succession of time slots each capable of transmitting X bits/sec, characterised in that the at least one low rate data terminal generates data at N bits/sec, where N is a binary submultiple of X, and in that the at least one low rate data terminal has means for accumulating X bits of generated data and when accumulated for transmitting said accumulated data in a time slot.
According to a second aspect of the present invention there is provided a method of communicating data over a communications system comprising a system control terminal, primary station transceiving means connected to the system control terminal, at least one low rate data terminal having means for establishing a data link with the primary station, said system control terminal establishing a data link with the at least one low rate data terminal, the data link comprising a plurality of time slots, each capable of transmitting data at X bits/sec, wherein said at least one low rate data terminal generates data at N bits/sec, where N is a binary submultiple of X, and wherein said at least one data terminal accumulates X bits of generated data and transmits said accumulated data in a time slot.
The communications system may be a TDMA system comprising a succession of frames of time slots (or physical channels). In such a system the accumulated data may be transmitted in an assigned time slot in one frame of every X/N frames. By means of the present invention those physical channels which are allocated to a particular low rate data terminal are fully utilised by data from said one terminal. However, that means that the corresponding physical channels normally allocated to that terminal in successive frames will not all be used in the data transaction of that terminal, and so can be allocated to another low rate data terminal having the same or a different data rate. For convenience a plurality of successive frames, say 16 frames, may be arranged as a multiframe and the frames containing a physical channel for transmitting data generated by a low rate data terminal are distributed evenly throughout the multiframe.
However as the low rate data terminals transmit and clear down in a substantially random manner, management of the physical channels in each frame has to be done by the system controller and the results communicated to the or each data terminal concerned.
In one embodiment of the present invention the allocation of the physical channels in a multiframe is such that wherever possible a new data transaction from the highest of the low rate data terminals can be handled. Such a method of allocation of the physical channels will require some control signalling to the low rate data terminals. For convenience the system controller maintains a map of the currently occupied or empty physical channels.
The present invention further provides a system control terminal for use in a communications system in which data is transmitted over a data link comprising a frame formed by a plurality of time slots, the system control terminal comprising means for forming a multiframe consisting of a plurality of said frames, means for establishing a data link with a low rate data terminal generating data at a rate N which is a binary submultiple of the data rate of a communication channel and means for allocating a time slot in 1 of every X/N frames of the multiframe for a transmission of data accumulated by the low rate data terminal at the data rate of the communication channel.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, wherein:
FIG. 1 is a block schematic diagram of a cordless telephone system,
FIG. 2 is a diagram of the channel and message structure,
FIG. 3 is a diagram of a multiframe comprising sixteen concatenated frames FR0 to FR15.
FIG. 4 is a diagram of a frame table,
FIG. 5 is a flow chart of a tidy-up algorithm,
FIG. 6 is a flow chart of a find holes algorithm,
FIG. 7 is a block schematic diagram of a cordless data terminal, and
FIG. 8 is a block schematic diagram of a system controller.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 3, the illustrated multiframe comprises sixteen concatenated TDMA frames FR0 to FR15, each frame having the same time slot or physical channel structure as shown in FIG. 2. The system includes a plurality of low rate data terminals which amongst themselves have different data rates such as 16 kbits/sec, 8 kbits/sec, 4 kbits/sec, and 2 kbits/sec, each of which is a binary submultiple of 32 kbits/sec, the data rate of the physical channel.
In accordance with the present invention each low rate data terminal accumulates data to be transmitted until it has 32 kbits and then transmits the data at the normal data rate for that physical channel. For example, in the case of a data terminal generating data at 8 kbits/sec., it has sufficient data for transmission once in every 32/8=4 frames. When initiating a data transaction, the low rate data terminal has to obtain a duplex voice channel using the dynamic allocation method described in the preamble of this specification and transmit amongst other things its identity to the primary station, which in turn relays it to the system control terminal. The system control terminal checks the identity against the terminal identities registered with the system, and determines that it is an 8 kbits/sec. terminal and so will require one reverse physical channel in every four successive frames in order to transmit a full physical channel's worth of data. The system control terminal which has created a multiframe of 16 frames for use by low rate data terminals, maintains a list of free and occupied physical channels in a channel map store. For convenience the system control terminal has reserved one physical channel in each frame, say channel R4 in one frequency channel, for use by low rate data terminals. The system controller scans the map store to see if it is able to accept a data terminal requiring 1 physical channel in every 4 frames for its transmission. Assuming that there is no difficulty, the system control terminal informs the data terminal by way of the primary station which frames of the multiframe the data terminal can transmit in. The start of each multiframe is indicated by a flag transmitted in the first frame and the data terminal utilises its internal clock to determine the instances in which it can transmit. Because there may be several low rate data terminals involved in separate data transactions, the system control terminal has to operate a multiplex channel management procedure.
If for example the low rate data terminals have all the same data rate, then the multiplex channel management is relatively simple as indicated in the following tabular summary. The legends Two-, Four-, Eight- and Sixteen-way refer to the sequential levels of the multiplexed frames of terminals generating data at 16, 8, 4 and 2 kbits/sec, respectively.
______________________________________Multiplexing 16 KB 8 KB 4 kb 2 kbFRAME Two-way Four-way Eight-way Sixteen-way______________________________________FR 0 Call 0 Call 0 Call 0 Call 0FR 1 Call 1 Call 1 Call 1 Call 1FR 2 Call 0 Call 2 Call 2 Call 2FR 3 Call 1 Call 3 Call 3 Call 3FR 4 Call 0 Call 0 Call 4 Call 4FR 5 Call 1 Call 1 Call 5 Call 5FR 6 Call 0 Call 2 Call 6 Call 6FR 7 Call 1 Call 3 Call 7 Call 7FR 8 Call 0 Call 0 Call 0 Call 8FR 9 Call 1 Call 1 Call 1 Call 9FR 10 Call 0 Call 2 Call 2 Call 10FR 11 Call 1 Call 3 Call 3 Call 11FR 12 Call 0 Call 0 Call 4 Call 12FR 13 Call 1 Call 1 Call 5 Call 13FR 14 Call 0 Call 2 Call 6 Call 14FR 15 Call 1 Call 3 Call 7 Call 15FR 0 Call 0 Call 0 Call 0 Call 0FR 1 Call 1 Call 1 Call 1 Call 1______________________________________
However such a multiplex slot management procedure is not optimum if the system includes low rate data terminals generating data at different predetermined rates and requiring different multiplex requirements. The management method shown in the table implies that each level of multiplexing used will need its own dedicated physical channel (or duplex voice channel) in successive multiframes irrespective of how empty other multiplexed physical channels may be. However a more flexible scheme is one in which callers wanting different levels of multiplexing use the same physical channel up to the full capacity of the multiframe. This is illustrated in FIG. 3 in which the reverse slot R4 is used for low rate data transmissions and the different hatchings indicate different terminals having various predetermined data rates requiring four-, eight- or sixteen-way multiplexing indicated as 1:4, 1:8 and 1:16, respectively. Thus from FIG. 3 it will be noted that respective 1:4 transmissions are being made in frames FR0, FR4, FR8, FR12 and in frames FR1, FR5, FR9, FR13, respective 1:8 transmissions are being made in frames FR2, FR10 and FR3, FR11, and respective 1:16 transmissions are being made in frames FR6 and FR14. Frames FR7 and FRI5 are empty. If one or more of the transmissions cease and the relavent terminal(s) clear(s) down, then empty physical channels will occur in one or more frames which may not be distributed evenly throughout the multiframe. One effect of this uneven distribution of physical channels may be that the system controller may refuse a request on the ground that the multiplexing pattern required is not possible with the distribution of the empty physical channels held in its map store even though the number of empty physical channels is itself sufficient. However the distribution of the empty physical channels will permit the multiplexing of lower data rate transactions. In order to overcome this problem the multiplex channel management procedure includes a channel organisation algorithm which rearranges the occupied physical channels so that at any one time a request from the highest of the low rate data terminals can be accepted. For example if 4 physical channels are available but not evenly distributed, then the algorithm endeavours to rearrange them so that they are in the sequence FR0, FR4, FR8, FR12 or similar. Consequently not only can a 1:4 multiplexing request be accepted but also, as an alternative, two 1:8, four 1:16 or one 1:8 and two 1:16 requests. Frequently the rearrangement of the physical channels will involve moving subsisting 1:8 and 1:16 transactions to other frames in the multiframe and insodoing instructing the data terminals to change accordingly.
Assuming that most data terminals are fixedly sited with respect to their closest primary station, then a handover from one primary station to another is only likely to occur if the propagation path is interrupted by, for example the shifting of a large article of furniture in say an office environment. The situation will probably be different if the data terminal is portable and is transmitting whilst on the move. Handover of a subsisting data transaction is complicated by the fact that an already established multiplexing pattern has to be altered by a primary station which is already involved in several multiplexed data transactions. Accordingly any algorithm should minimise the amount of interference to those data channels already allocated to physical channels in a multiframe.
Referring to FIG. 4, the illustrated frame table shows the sixteen frames R0 to F15 and the various multiplexing combinations. A 1:16 multiplexing is shown by one physical channel being required in any one of the sixteen frames. A 1:8 multiplexing requires physical channels in pairs of evenly distributed frames, namely FR0, FR8; FR4, FR12; FR2, FR10 and so on. A 1:4 multiplexing requires physical channels in groups of four evenly distributed frames such as FR0, FR8, FR4, FR12; FR2, FR10, FR6, FR14; and so on. Lastly 1:2 multiplexing requires physical channels in groups of eight evenly distributed frames, that is frames FR0, FR2, FR4, FR6, FR8, FR10, FR12, FR14, or frames FR1, FR3, FR5, FR7, FR9, FR11, FR13, FR15. By representing a multiframe as shown in FIG. 4 it is fairly easy to see what is required by a tidy-up algorithm.
At any one time, a number of multiplex calls may be in progress. There will be a number of unused frames, considered as "holes" in the table shown in FIG. 4. The tidy-up procedure must increase the size of these holes by merging smaller holes together. Two holes of size 1 can always be merged to obtain one hole of size 2. Likewise, two holes of size 2 can always be merged to a hole of size 4. However, no wrap-round of holes is permitted, and size 2 holes must be right- or left-justified in the block above. No centrally spaced (e.g. (8,4)) size 2 holes are allowed. Thus, the table in FIG. 4 allows equally spaced frames to be viewed as a contiguous block.
Data on the holes will be stored in four tables: SIZE 8, SIZE 4, SIZE 2 and SIZE 1. The procedure will have finished when no more than one entry exists in the three latter tables.
FIG. 5 is a flow chart of a tidy-up algorithm, that is the forming into usable groups of 2, 4 or 8 frames of empty physical channels, if necessary by reassigning operating low rate data terminals to other frames.
The flow chart begins at a start block 100. Block 102 relates to the operation of checking the size 1 hole table, that is the checking of what single frames are not allocated. Block 104 relates to checking if there is more than one size 1 hole. If the answer is Yes(Y), then two size 1 holes are selected, for example FR0 and FR8, block 106, and these two holes are merged, block 108, to form one new size 2 hole, that is FR0,FR8 which it will be noted from FIG. 4 can be used for a 1:8 transmission as well as two 1:16 transmissions. The flow chart then reverts to block 104 and if the answer is Yes(Y) the cycle of forming size 2 holes is repeated until the answer from the block 104 is No(N).
The flow chart then proceeds to block 110 where a check is made in the size 2 hole table. Block 112 relates to checking to see if there is more than one size 2 hole. If the answer is Yes(Y) then in block 114 two size 2 holes are selected, for example FR0,FR8 and FR4,FR12, and in block 116 these holes are merged to form a size 4 hole FR0, FR8, FR4 and FR12, see FIG. 4. The flow chart reverts to the block 112 and if the answer is Yes(Y) then the cycle of forming size 4 holes is repeated until the answer from the block 112 is No(N).
The flow chart then proceeds to block 120 where a check is made in the size 4 hole table, that is for groups of 4 holes which can be used for a 1:4 transmission. Block 122 relates to checking to see if there is more than one size 4 hole. If the answer is Yes(Y) then in block 124 two size 4 holes are selected, for example FR0, FR8, FR4, FR12 and FR1, FR9, FR5, FR13. In block 126 these two size 4 hole are merge to form a size 8 hole. However the merging operation may require the reassignment of four allocated frames. In the case of the example given above, the size 4 hole FR1, FR9, FR5, FR13 cannot according to FIG. 4 simply be combined with the other size 4 hole. In order to make the size 8 hole frames FR2, FR10, FR6, FR14 have to be vacated, if necessary by reassigning operating data terminals to frames FR1, FR9, FR5, FR13. Once this has been done then the vacated holes are merged with FR0, FR8, FR4, FR12 to form a size 8 hole. The flow chart then reverts to block 122. If the answer from the block 122 is No(N) the algorithm is terminated in block 128.
Before the tidy up procedure can be used there has to be a map of holes. Any procedure which looks for the holes will also have to classify them in order of size, making sure that a hole classified as, for example, a size 2 hole is not also represented as two size 1 holes. An algorithm for mapping the holes is shown in FIG. 6.
The flow chart begins at block 130 and the first operation, block 132, is to check each frame in the multiframe for activity. This search can be conveniently done by following the sequence shown in FIG. 4, that is FR0,FR8--FR14,FR1--FR7,FR15. The next operation is to form a list of size 1 holes, block 134.
In block 136 a check is made to see if there are any size 8 holes, that is the top or bottom row of frames in FIG. 4. If the answer is Yes(Y), then in block 138 the size 8 hole is removed from the list and added to the size 8 table. The flow chart reverts to block 136. When the answer from block 136 is No(N), the flow chart proceeds to block 140 in which a check is made to see if there are any size 4 holes, for example FR0, FR8, FR4, FR12. If the answer is Yes(Y), the size 4 hole is removed and added to the size 4 table, block 142. The flow chart reverts to the block 140. When the answer from the block 140 is No(N) the flow chart proceeds to block 144 in which a check is made to see if there are any size 2 holes. If the answer is Yes(Y), then in block 146 the size 2 hole is added to the size 2 table. The flow chart reverts to the block 144. When the answer from the block 144 is No(N), the flow chart is terminated at block 148.
In operation, when a new call is to be made, call set-up procedures will use the size 1, 2, 4 and 8 tables to find a suitable hole in which to place the call, starting with the smallest size possible and trying successively larger tables until an entry is found. The table entries must be readjusted as necessary to reflect the arrival of the new call.
Call clear-down procedures, upon completion of a call, will add the cleared frame(s) or hole to the appropriate table and call up the tidy-up procedure.
FIG. 7 illustrates an embodiment of a data terminal DT. The terminal comprises a low rate data terminal 30 which is electrically connected to a cordless secondary station 32 which may be integrated into the terminal 30. The secondary station 32 comprises a transmitter 34 connected to an antenna 36 which is also connected to a receiver 38. A local oscillator 35 is connected to the transmitter 34 and receiver 38 and is controlled to select the particular frequency channel of the ten available for DECT. A MODEM 40 is connected to both the transmitter 34 and the receiver 38. An output of the MODEM 40 is connected to a de-multiplexer 42 which separates signalling data from message data. The signalling data is relayed to a control processor 44 which controls the operation of the secondary station 32. The control processor 44 is also connected to a RAM 46 which stores control data, a keypad 48 and a LCD device 50. Any message data for the data terminal is held in a buffer store 52 in readiness for transferring to the data terminal 30. Low rate data from the terminal 30 is accumulated in another buffer store 54. An output from the buffer store 54 is connected to an input of a multiplexer 56 which multiplexes signalling data from the control processor 44 with message data from the store 54. An output of the multiplexer 56 is connected to the MODEM 40.
FIG. 8 illustrates diagrammatically an intelligent controller 60 which can, for example be used as part of the system control terminal 14 or 15 in FIG. 1. The controller 60 comprises a control unit 62 which serves amongst other things to control the routing of data within the controller and to control the multiplex channel management operation. Means 64 are connected to the control unit 62 for monitoring the radio channels, for maintaining a record of the busy and idle duplex voice channels and for multiplexing data signals low rate data terminals on the corresponding physical channels of the frames of a multiframe. A data router 66 directs data packets to an error checking and correction stage 68. Data packets which have been deemed correct by the stage 68 are transferred to a message assembler 70 which builds up a data message using for example a packet numbering system. Messages to be forwarded are transferred to an output interface 72 which may be coupled to an ISDN link. Input message data from an external source such as the ISDN link are transferred to the message assembler 70 by the interface 72. In the assembler messages for onward transmission are reformatted and are routed to the control device 62 by means of a bus 74. The control device multiplexes the different data messages into the relevant physical channels.
Acknowledgements for the receipt of correct packets are generated in a stage 76 and relayed to the control unit 62 for onward transmission in the signalling field of the data message. If any of the data packets are found to be uncorrectable then the error correction stage 68 instructs the stage 76 to include a retransmission request in the acknowledgement which it is going to send.
The data from the error correction stage 68 is also sent to detector 78 adapted to detect an absence of signals or the presence of padding. In response to the detection of an absence of signals or padding bits in the same physical channel(s) of successive multiplexed frames, the detector 78 instructs a stage 80 to generate a physical channel release instruction which is sent to the control unit 62 which decides what should be done with the physical channel(s) to be released and issues the necessary instruction to the primary and secondary stations by way of the wideband link 10, 11 or 12, 13. A channel map store 80 is connected to the control unit 62 for storing an uptodate record of what channels are occupies or empty.
Whilst the controller 60 has been shown as comprising a plurality of circuit stages, it could be implemented using a suitably programmed microcontroller, e.g. a microcontroller from the 68000 series.
For convenience of description, the present invention has been described with reference to DECT. However, the method in accordance with the present invention may be used in other suitable systems, such as a wired LAN system.
From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the design, manufacture and use of digital communication systems and devices and component parts thereof, and which may be used instead of or in addition to features already described herein, without departing from the scope of the ensuing claims.
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In a cordless communications system, such as DECT, data is transmitted to or from a data terminal in an assigned channel in each TDMA frame. In order to accommodate data terminals having lower data rates than the capacity of the channel, such a data terminal accumulates its data during several frames in a buffer store until the accumulated data corresponds to the channel capacity, and is then transmitted in the frame in which that occurs. In order to utilize such interruptions in transmission from a plurality of low rate data terminals, the system control terminal treats each successive sequence of a predetermined number of frames (FR0 to FR15) as a multiframe, and transmissions from low rate data terminals are assigned to multiplexed frames which minimize the number of unoccupied channels in each multiframe.
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RELATED APPLICATIONS
[0001] This is a continuation-in-part of Ser. No. 09/540,135, filed Mar. 31, 2000, and to be hereafter issued as U.S. Pat. No. 6,358,107, which in turn is a continuation of Ser. No. 09/028,735, filed Feb. 24, 1998, now U.S. Pat. No. 6,045,418, which in turn is a divisional of Ser. No. 08/456,188, filed May 31, 1995, now U.S. Pat. No. 5,720,635, which in turn is a divisional of Ser. No. 07/699,336, filed May 13, 1991, now U.S. Pat. No. 5,421,753.
FIELD OF THE INVENTION
[0002] This invention is related generally to propulsion units for boats and, more particularly, to marine jet drives.
BACKGROUND OF THE INVENTION
[0003] Marine jet drives which propel vessels by means of water jets have long been known and used, and have certain significant advantages over the traditional external propeller units. A typical marine jet drive includes an engine-driven impeller which rotates inside an impeller housing. The impeller pumps water from below the vessel through a water intake duct, and then pressurizes and expels the water through a diffusor housing and a nozzle behind the vessel.
[0004] A typical example of such a conventional marine jet drive is seen in U.S. Pat. No. 3,935,833, which shows a pump which may be driven vertically or horizontally and is positioned near the bottom and transom of a marine vessel. The conventional jet propulsion systems have certain general advantages that make them especially attractive under circumstances where a conventional ship's propeller would be exposed to damage by contact with underwater objects. A jet drive has the further advantages that it does not produce appendage drag allowing more efficient operation and that it is safe for swimmers and animals that could be hurt by the rotating blades of an external propeller.
[0005] Despite these advantages, marine jet drives of the prior art have some problems and shortcomings, including as set forth below:
[0006] Among the problems with marine jet drives, as often with vessels having conventional propulsion means, are that the exhaust produces significant noxious odor, noise and heat signature behind and near the vessel, adversely affecting personnel on and near the vessel. In certain vessels with conventional propulsion means, exhaust can be released under water, which in theory can mitigate the problems to some extent. This in some cases can also be done with vessels having marine jet drives; however, as with conventional vessels, significant problems can remain.
[0007] Indeed, in marine jet drives, underwater exhausting is particularly problematic, because any exhaust gases in the water which is pumped into the jet drive unit from beneath the vessel will drastically interfere with operation of the jet drive—a very serious problem. Thus, the problems of noxious odors, noise and heat behind and near the vessel are particularly difficult to solve in vessels having marine jet drives.
[0008] In the past there have been some efforts to in some manner use the jet stream in connection with exhaust. One example is U.S. Pat. No. 3,943,876, which shows engine exhaust in combination with the jet stream; however, the exhaust is peripheral to the jet stream and is added behind the jet nozzle. The system of such patent does not significantly enhance efficiency or remove exhaust fumes and heat with the jet stream, nor does it serve to adequately suppress exhaust noise. U.S. Pat. No. 4,552,537 uses exhaust gases and engine-generated heat to decrease behind-the-jet nozzle frictional losses between a submerged jet stream and surrounding water in order to render the jet stream more effective.
[0009] In prior art marine jet drives, however, exhaust gases are not discharged with the jet stream. However, even if such an idea had been considered, difficult and highly significant problems would arise relating to a seeming inability to discharge the engine exhaust gas with the jet stream. The problem would be the matter of just how one would reasonably get the exhaust into the jet stream at the appropriate location.
[0010] In summary, substantial problems and shortcomings exist with respect to dealing with the engine exhaust of marine jet drives.
OBJECT OF THE INVENTION
[0011] It is accordingly a primary object of the present invention to provide a marine jet drive propulsion system that overcomes problems and shortcomings of the prior art, including those set forth above.
[0012] Another object of this invention is to provide a marine jet drive propulsion system that overcomes disadvantages of the known jet drives.
[0013] Another object of this invention is to provide a marine jet drive which increases the comfort of people in the vessel by overcoming the problems of noxious odors, noise and heat behind and near the vessel.
[0014] Another object of this invention is to provide a marine jet drive which is quite and powerful in operation.
[0015] Another object of this invention is to provide a marine jet drive which avoids any release exhaust near the vessel.
[0016] Still another object of the invention is to provide a marine jet drive which successfully merges the engine exhaust stream into the jet stream of the jet drive at an appropriate location.
[0017] Yet another object of this invention is to provide a marine jet drive with improved engine performance.
[0018] These and other objects of the invention will be apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
[0019] This invention is an improved marine jet drive which overcomes various problems and shortcomings of the prior art, including those referred to above. The invention is a marine jet drive system which places the engine exhaust internal to the jet stream of water. This serves to improve engine efficiency because of suction created by the jet stream, and greatly improves the comfort of people on the vessel by releasing the exhaust and its attendant noxious odors, noise and heat to the atmosphere well behind the vessel. The invention also involves particular structures which serve to allow engine exhaust to exit through the jet drive water stream.
[0020] Marine jet drives are, of course, powered by engines having exhaust lines. Each marine jet drive has an impeller and an impeller housing, a diffusor having a diffusor housing and stator vanes, a nozzle having a rearward end, and a water intake duct in front of the impeller housing. The improvement of this invention involves an inner housing which (a) is disposed inside the diffusor housing, (b) forms an inner exhaust chamber, (c) has an exhaust discharge tube portion that extends rearwardly into the nozzle and terminates in a rearward opening, and (d) is attached to the diffusor housing by the stator vanes. The exhaust line extends to the diffusor housing, and at least one of the stator vanes is hollow and open at its opposite ends to allow exhaust to flow from the exhaust line to the inner exhaust chamber, such that the exhaust exits through the exhaust discharge tube portion into the jet water flow.
[0021] Preferred embodiments include a plenum on the outside of the diffusor housing, such plenum feeding exhaust to a plurality of hollow stator vanes.
[0022] The preferred embodiments also preferably include a valve on the plenum which serves to vent the plenum when pressure in the plenum is greater than ambient pressure. Such valve remains closed when pressure in the plenum is not greater than ambient pressure. Operation of this valve allows continued outflow of exhaust during other than forward jet drive operation.
[0023] It is highly preferred that the exhaust discharge tube portion be removably attached to the remainder of the inner housing. This allows easy replacement.
[0024] More broadly defined, this invention involves an exhaust discharge outlet disposed inside a marine jet drive nozzle, the discharge outlet being in fluid communication with the engine exhaust line. The fluid communication preferably is through at least one of the stator vanes which are part of the diffusor.
[0025] This invention is also a method for improving performance of an engine which drives a marine jet drive, the jet drive including, of course, a nozzle for water outflow.
[0026] The inventive method involves producing suction to facilitate exhaust flow from the engine by discharging exhaust within the water outflow at the nozzle. The enhanced exhaust outflow serves to improve engine performance.
[0027] In the method of this invention, exhaust discharge is preferably from an exhaust discharge tube which is surrounded by water outflow from the jet drive nozzle. The exhaust discharge most preferably occurs at a position substantially flush with the position of water discharge, in order to obtain a maximum suction effect. The exhaust discharge tube and the jet drive nozzle preferably have discharge ends which are substantially flush with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] [0028]FIG. 1 is a cross-sectional view, taken along the drive-train centerline, of a marine jet drive in accordance with a preferred embodiment of this invention, showing its interior construction.
[0029] [0029]FIG. 2 is an enlarged fragmentary and partially broken top view of the jet drive shown in FIG. 1.
[0030] [0030]FIG. 3 is an enlarged left-side elevation of FIG. 1, i.e., a rear elevation of the jet drive.
[0031] [0031]FIG. 4 is an enlarged fragmentary cross-sectional view of an alternative embodiment, taken along the drive-train centerline (as in FIG. 1), illustrating a preferred variation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] The figures illustrate a marine jet drive 200 in accordance with the instant invention. As shown in FIGS. 1 and 2, jet drive 200 is located generally at the transom T of a vessel and generally above the keel line K. The direction of the jet stream J is rearward, causing the vessel to move forward as indicated by arrow F.
[0033] Jet drive 200 has the following components: an impeller housing 1 attached to intake flange 2 ; a rotatable impeller 3 disposed in impeller housing 1 and having an axis of rotation aligned generally with keel line K; a diffusor housing 4 ; an inner housing 5 disposed inside diffusor housing 4 ; a drive shaft 6 rotatably connecting impeller 3 with an engine 7 (shown in very fragmentary form); a rearward-facing nozzle 8 attached to diffusor housing 5 and having means of deflecting jet stream 3 ; an engine exhaust discharge tube 9 which forms a portion of inner housing 5 ; a water intake duct 10 which is placed ahead of impeller housing 1 , attached to the vessel to transmit the generated thrust forces thereto; and an intake grid 11 disposed in water intake duct 10 .
[0034] Impeller 3 includes an impeller hub 12 , an impeller bell 13 and a plurality of impeller blades 14 having blade tips 16 radially extending from impeller bell 13 . A circular wear ring insert 15 is inserted coaxially, snugly fitting the inside of impeller housing 1 . Impeller blade tips 16 extend to within close proximity of the inner surface 17 of wear ring insert 15 . Blades 14 are advantageously positioned to promote fluid flow from water intake duct 10 to diffusor housing 4 when impeller 3 rotates.
[0035] Diffusor housing 4 supports inner housing 5 by a plurality of stator vanes 18 , which are radially disposed between diffusor housing 4 and inner housing 5 , as seen best in FIG. 1. Stator vanes 18 are advantageously positioned to recover the rotational energy imparted by impeller 3 . Several of stator vanes 18 are hollow to form internal ducts (or ports) 93 for transmitting exhaust gases to inner housing 5 from the periphery of diffusor housing 4 , as described further below.
[0036] Exhaust discharge tube portion 9 of inner housing 5 is the rear portion of inner housing 5 and has a rearward end 9 a that is located in the jet stream within nozzle 8 , thereby producing suction for the discharge of engine exhaust gases. Exhaust discharge tube 9 is supported in place by being a portion of inner housing 5 ; as a part of inner housing 5 , it is in fluid communication with an inner exhaust chamber 78 .
[0037] A pair of outer plenums 79 are located on the periphery of diffusor housing 4 and are in fluid communication with inner exhaust chamber 78 via ducts 93 extending through several of stator vanes 18 . The exhaust from a pair of engine exhaust lines 80 (see FIGS. 1 and 3) enters outer plenums 79 , and from there flows through ducts 93 into inner exhaust chamber 78 .
[0038] Outer plenums 79 are provided with flapper valves 81 that open when pressure inside outer plenums 79 exceeds atmospheric pressure. This allows engine exhaust gases to escape when impeller 3 is not turning or when jet drive 200 is operating in reverse. When jet drive 200 is operating in reverse mode, exhaust discharge tube 9 is substantially closed by steering/reversing deflectors 86 and 87 , thereby preventing water from entering the exhaust system.
[0039] The exhaust suction created at rearward end 9 a of exhaust discharge tube 9 has a beneficial effect on the performance of engine 7 , thereby improving efficiency and increasing available power. Exhaust fumes are ejected with water jet stream J, and exhaust noise is muffled since it is not exposed to the atmosphere in the vicinity of the vessel. Exhaust discharge occurs at a position surrounded by water outflow from the jet drive nozzle 8 .
[0040] Exhaust discharge tube 9 may be detachable from inner housing 5 for ease of replacement of tube 9 . This avoids the need for a complicated and costly maintenance procedure.
[0041] [0041]FIG. 4 shows a portion of a marine jet drive 300 which is a preferred variation of marine jet drive 200 of FIGS. 1 - 3 . Jet drives 200 and 300 differ only in the locations of the discharge ends of their exhaust discharge tubes 9 at their respective jet drive nozzles 8 . Except for the numbering for the rearward end 9 b of exhaust discharge tube 9 of marine jet drive 300 , the part numbers used for marine jet drive 300 of FIG. 4 are identical to the numbers for the corresponding identical parts of marine jet drive 200 of FIGS. 1 - 3 .
[0042] It is highly preferred that the exhaust discharge occur at a position which is substantially flush with the position of water discharge, in order to obtain a maximum suction effect. Thus, as shown in FIG. 4, rearward end (i.e., discharge end) 9 b of exhaust discharge tube 9 and the discharge end 8 b of nozzle 8 are substantially flush with one another.
[0043] While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.
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A marine jet drive having through-the-nozzle engine exhaust, thereby to avoid or minimize noxious odors, noise and heat problems. A method for improving marine jet drive engine performance, including producing suction to facilitate exhaust flow from the engine by discharging exhaust within the water outflow in the nozzle; exhaust is most preferably discharged at a position flush with the position of water discharge.
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TECHNICAL FIELD
The present invention generally concerns buoyant structural elements adapted for subsea use. More specifically, the present invention concerns a buoyant, pressure balanced tether suitable for use in a tension leg platform.
BACKGROUND OF THE INVENTION
Tension leg platforms are a type of marine structure having a buoyant main body secured to a foundation on the ocean floor by a set of tethers. A typical tension leg platform is shown in FIG. 1 of the appended drawings. The point of connection between the buoyant main body and each tether is selected so that the main body is maintained at a significantly greater draft than it would assume if unrestrained. The resulting buoyant force of the main body exerts an upward load on the tethers, maintaining them in tension. The tensioned tethers substantially restrain the tension leg platform from pitch, roll and heave motion induced by waves, current and wind. It is important that the installation tension of the tethers be sufficiently great to ensure that under ordinary wind, wave and tide conditions the tethers are not permitted to go slack.
Tension leg platforms have attracted interest for use in offshore oil and gas production operations in water depths exceeding about 250 meters (820 feet). As water depths exceed 200-350 meters (656-1148 feet) the structure required to support the deck of a jacket or other conventional structure becomes extremely expensive. Tension leg platforms, however, rely on a tensile rather than compressive loading of the structure securing the platform to the ocean floor, and thus largely avoid the depth sensitivities inherent to conventional structures. It has been suggested that tension leg platforms could be employed in depths up to 3000 meters (9840 feet), whereas the deepest present application of a conventional offshore jacket is in a water depth of approximately 412 meters (1350 feet).
Though tension leg platforms avoid many problems faced by conventional platforms, they are subject to their own special problems. The most significant of these concerns buoyancy requirements. The main body of a tension leg platform must be provided with sufficient buoyancy to support not only its own weight, but also the weight of the equipment and crew facilities necessary to oil and gas drilling and producing operations. Further, the main body must also support the load imposed by the tensioned tethers. It is highly desirable to provide the tethers with buoyancy sufficient to offset some or all of their own weight. This decreases the load imposed on the main body by the tensioned tethers, eliminating the need to provide the main body with an additional degree of buoyancy sufficient to support the weight of the tethers. The decreased main body buoyancy requirements decrease the size and cost of the tension leg platform.
United Kingdom patent application No. 2,142,285A, having a priority filing date of June 28, 1983, teaches a tether design in which the tether is provided with significant inherent buoyancy. This benefit is obtained through the use of tubular tethers filled with gas pressurized to a level above the hydrostatic seawater pressure encountered at the lowest point in the tether. This use of pressurized gas prevents tether collapse in deep water applications. A system is provided for monitoring the gas pressure of the tether to detect any leaks that may occur. This design is disadvantageous in that it imposes a differential pressure across the wall of the tether which, near the ocean surface, will exceed the hydrostatic seawater pressure at the ocean floor. For an installation depth of 600 meters (1970 feet) this corresponds to a differential pressure of 6.1 megapascals (890 psi). The tether walls must be designed to withstand this high differential pressure. Also, the joints securing the individual sections of the tether together must include seals sufficient to prevent gas leakage across the great pressure differential. Further, because the tether interior forms a single, continuous channel, the entire tether could flood if a leak developed of sufficient size that air escaped more quickly than it could be replaced by the tether gas pressurization system.
As an alternative to an internal buoyancy system, buoyancy modules can be secured to the outside of submerged members. A riser buoyancy system of this type is shown in U.S. Pat. No. 4,422,801, issued on Dec. 27, 1983. This riser buoyancy system includes a number of individual air cans secured to the outer wall of the riser. Such systems would be disadantageous for use with the tethers of a tension leg platform in that they complicate inspection of the outer surface of the tether for cracks and corrosion. Also, external buoyancy systems increase the effective diameter of the tether relative to tethers having internal buoyancy systems, increasing the forces imposed on the tether by ocean currents and waves.
It would be advantageous to provide a tether buoyancy system which avoids significant pressure differentials across the wall of the tether; which maintains the outer surface of the tether free from buoyancy modules; which is controllably ballastable and deballastable to aid in tether installation and removal; which avoids the need for seals in the joints joining the individual sections of the tether; which remains substantially buoyant in the event of a leak through a tether wall; which can be deballasted continuously as individual sections of the tether are being joined in the course of tether installaion; and which accommodates a simple and reliable method for determining the location of any leak in the tether.
SUMMARY OF THE INVENTION
A pressure balanced buoyant tether is set forth which is especially well suited for use in a tension leg platform. The tether is tubular and is divided by bulkheads into a series of discrete buoyancy cells. Preferably, the tether is composed of a series of connectable tether sections each having a bulkhead at its upper end, each tether section serving as a discrete buoyancy cell. Secured to each bulkhead is a differential pressure valve adapted to permit gas in the buoyancy cell immediately beneath the bulkhead to pass into the buoyancy cell above the bulkhead in response to the existence of a preselected minimum pressure differential across the bulkhead. Preferably, this preselected pressure differential equals the hydrostatic seawater pressure differential across the length of a single tether section. Thus, by maintaining the lowermost buoyancy cell of the tether at the pressure of the surrounding seawater, all other portions of the tether will be automatically maintained at pressures substantially equal to the surrounding seawater. Means are provided for injecting gas into at least the lowermost of the buoyancy cells. Means are also provided for removing any ballast liquid or sea water within at least the lowermost buoyancy cell as gas is injected.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference may be made to the accompanying drawings, in which:
FIG. 1 shows an elevational view of a tension leg platform incorporating the buoyant, pressure balanced tethers of the present invention;
FIG. 2 shows an elevational cross section of a portion of a tension leg platform tether incorporating a preferred embodiment of the present invention;
FIG. 3 shows an elevational cross section of a portion of a tension leg platform tether incorporating an alternate embodiment of the present invention.
FIG. 4 shows an elevational cross section of the ballast-deballast tool situated in position to inject ballast liquid or gas into a buoyancy cell of the embodiment shown in FIG. 3; and
FIG. 5 shows a simplified diagrammatic view of the header tank and associated equipment used for transferring ballast liquid to and from the tether of the embodiment shown in FIG. 3.
These drawings are not intended as a definition of the invention, but are provided solely for the purpose of illustrating certain preferred embodiments of the invention, as described below.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 shows a diagrammatic view of a preferred embodiment of the pressure balanced buoyant tether 10 of the present invention. As will become apparent in view of the following discussion, the preferred embodiment of the present invention is especially well suited for use in securing a tension leg platform (TLP) to a foundation on an ocean bottom. However, the present invention is also useful in other applications in which it is desirable to provide buoyancy to submerged elements. To the extent that the embodiments described below are specific to TLP tethers, this is by way of illustration rather than limitation.
As best shown in FIGS. 1 and 2, the structural portion of each tether 10 is composed of a plurality of tubular sections 12, each having a tubular load bearing wall portion 14 surrounding a central channel 15. Each tether section 12 is provided with a threaded pin 16 at its lower end and a threaded box 18 at its upper end so that the tether sections 12 may be joined one to the other to establish a single elongate tether 10. All but one of the tether sections 12 are of a uniform length, preferably in the range of from 10-50 meters (33-164 feet), with the uppermost tether section 12 having a greater or lesser length as necessary to make the complete tether 10 the precise length required for the application. A base latch 19 is secured beneath the lowermost tether section 12 for locking the tether 10 to a foundation 20 on the ocean floor 21. The base latch 19 is provided with a flexjoint 22 to permit the tether 10 to pivot about the foundation 20 to accommodate limited lateral motion of the TLP 24 in response to wind, waves and ocean currents.
A bulkhead 25 is situated at the upper end of each tether section 14. The bulkhead 25 could alternately be situated at the lower end of each tether section 14; however, as will be appreciated in view of the subsequent disclosure, this would increase the likelihood of leakage at the joint joining individual tether sections and would introduce complications in maintaining pressure integrity of the central access tube (detailed below), if a central access tube is used. When the individual tether sections 12 are threaded together to form the tether 10, the bulkheads 25 divide the interior of the tether 10 into a series of sealed compartments extending along the length of the tether 10, each serving as an individual buoyancy cell 31. As further detailed below, eacy buoyancy cell 31 is filled with gas to provide the tether 10 with the required degree of buoyancy. The tether wall thickness to diameter ratio is established to provide the tether 10 with a preselected degree of buoyancy when the buoyancy cells 31 are completely filled with gas. The wall thickness to diameter ratio of the tether 10 will typically be in the range of from 1:25 to 1:40.
The tether 10 is provided with means 32 for permitting gas to cascade from any buoyancy cell 31 to the buoyancy cell 31 above in response to the existence of a preselected pressure differential between the adjoining buoyancy cells 31. This cascade permitting means 32 allows the internal pressure of the tether 10 to be brought substantially into balance with the external hydrostatic seawater pressure along the full length of the tether 10. In the preferred embodiment the cascade permitting means 32 includes a one-way differential pressure valve 34 situated in a fluid transfer passage 35 extending through each bulkhead 25. Preferably, the differential pressure valve 34 is a diaphragm-assisted pressure relief valve. Each differential pressure valve 34 has an inlet port in fluid communication with the uppermost portion of the buoyancy cell 31 immediately beneath the bulkhead 25 and an outlet port in fluid communication with the lowermost portion of the buoyancy cell 31 immediately above the bulkhead 25. The differential pressure valves 34 are each adapted to open in response to the existence of a preselected pressure differential between its inlet and outlet ports. Preferably, this preselected pressure differential is substantially equal to the hydrostatic seawater pressure differential along the length of an individual tether section 14. Thus, for a tether 10 in which each tether section 14 is 30 meters (98 feet) long, each differential pressure valve 34 should be adjusted to open at a pressure differential of about 300 kPa (44 psi), the hydrostatic pressure of a 30 meter column of sea water. It should be understood that to enhance reliability of the tether buoyancy system more than one differential pressure valve could be provided for controlling fluid transfer through each bulkhead 25.
Means 40 are provided for injecting pressurized gas into the lowermost buoyancy cell 31 of the tether 10. In the preferred embodiment, the lowermost buoyancy cell 31 is provided with a gas injection port 42 to which a fluid transfer umbilical 44 is secured. A compressor 46 situated on the TLP 24 supplies pressurized gas to the umbilical 44. For a group of individual tethers 10, as in a TLP, a separate umbilical 44 can be provided for each tether 10, the umbilical 44 being adapted to remain coupled to the tether 10 at all times. Alternately, the umbilical 44 can be adapted for removal from the tether 10 during those times when it is not required for tether pressurization. In such an embodiment, a single umbilical 44 can be used to service a number of tethers 10. Removal and reattachment of the umbilical 44 is effected by a diver or a remotely operated vehicle ("ROV").
In certain applications it may be desirable to ballast the lower portion of the tether 10 prior to installation or removal. This is advantageous in that the weight of the ballast imposes a tensile load on the tether, minimizing the buckling loads to which the tether 10 is exposed during periods when its lower end is not supported. Preferably water or some other liquid is used as ballast. Means 50 are provided to selectively transfer the liquid ballast to and from the lowermost tether section 12. In the preferred embodiment, the compressor 46 of the gas injection means 40 is also adapted to inject ballast liquid through the fluid transfer umbilical 44 into the lowermost buoyancy cell 31. An ROV operated ballast valve 52 is provided at the bottom of the lowermost tether section to permit liquid ballast to be forced out of the lowermost buoyancy cell 31 to the surrounding ocean water under the pressure of gas injected into the lowermost buoyancy cell 31.
Installation of the tether 10 from the TLP is straightforward. The lowermost tether section 12 is lifted into position above the appropriate tether shroud 54 by the tether handling crane 56. The ballast valve 52 is closed and the tether section 12 is filled with ballast liquid. The umbilical 44 is secured to the gas injection port 42. As additional tether sections 12 are secured to the tether 10 and the tether 10 lowered, gas is injected through the umbilical 44 at a rate sufficient to maintain the differential pressure between the tether 10 and the surrounding seawater low enough to prevent damage to the tether 10 or leakage of seawater into any buoyancy cell 31 through the tether section couplings. As gas is injected, it cascades upward through the differential pressure valves 34 so that the pressure differential between any two adjacent buoyancy cells 31 is equal to the actuation pressure of the differential pressure valves 34. Once the tether 10 is secured to the foundation 20, the ballast valve 52 is opened by an ROV and gas is injected through the umbilical 44 until all ballast liquid has been forced from the lowermost tether section, following which the ballast valve 52 is closed. Following this, additional gas may be injected to raise the pressure of each buoyancy cell 31 a preselected amount, preferably in the range of from 0.07-0.21 MPa (10-30 psi), above the hydrostatic seawater pressure at the base of each tether section 12. The pressure of the uppermost tether section 12 can be monitored to verify proper operation of the cascade permitting means 32. Periodically during use of the tether 10 additional gas should be injected into the lowermost tether section 12 to repressurize any buoyancy cell 31 whose pressure has decreased due to gas leakage or corrosion.
Prior to tether removal, the lowermost tether section is ballasted by injecting ballast liquid through the umbilical 44. The displaced gas cascades upward through the tether 10 via the differential pressure valves 34. Alternately, the ballast valve 52 can be opened and air pressure bled via the umbilical 44 from the lowermost tether section 12, allowing the lowermost tether section 12 to flood with seawater.
Several measures may be taken to minimize internal corrosion of the tether 10. Much potential corrosion can be avoided by excluding sea water from the interior of the tether 10. This is accomplished by maintaining the pressure within each buoyancy cell 31 at a slightly higher level than that of the surrounding seawater, as detailed previously. The ballast liquid used in tether installation and removal is preferably a liquid which will not support corrosion, such as ethylene glycol. However, if water is used, it should have a low ion concentration and should include suitable corrosion inhibitors. Additionally, the gas injected into the tether 10 is preferably a relatively inert gas, such as nitrogen, rather than air. If air is used to pressurize the tether 10, an internal cathodic protection system using magnesium anodes and an inorganic zinc coating on all internal metal surfaces of the tether 10 will greatly decrease the rate of corrosion. Additionally, any air injected into the tether 10 should be substantially free of water vapor to prevent water condensation and collection at the bottom of each buoyancy cell 31.
FIG. 3 shows an alternate embodiment of the present invention. This embodiment is generally similar to the embodiment detailed above, but further includes a central access system 60 for permitting various tether operations to be carried out through the tether 10 itself. The central access system 60 serves several purposes: it provides a passage for a tool (not shown) used to activate and deactivate the tether base latch 19; it permits a ballast-deballast tool, described below, to be lowered to any selected tether section 12 to inject gas or ballast liquid into the corresponding buoyancy cell 31; and it permits passage of a buoyancy cell inspection tool (not shown).
The primary component of the central access system 60 is a central access tube 62 extending the full length of the tether 10. The access tube 62 is made up of a number of individual sections 64, each secured within a corresponding one of the tether sections 12. Each access tube section 64 has opposed first and second ends 66, 68 provided, respectively, with a box element 70 and a pin element 72. The access tube pin and box elements 72, 70 are substantially flush and concentric with, respectively, the tether section box and pin 18, 16 so that as adjoining tether sections 14 are threaded together, the access tube pin 72 of the upper tether section automatically stabs into the access tube box 70 of the lower tether section. A series of supports 73 are provided along the length of each tether section 12 to stabilize and centralize the central access tube 62 within the tether 10. The central access tube 62 defines a channel passing through each of the bulkheads 25 and extending the full length of the tether 10.
A series of valves are secured along the length of the central access tube 62 to establish selective communication between the interior of each buoyancy cell 31 and the interior of the central access tube 62. As shown in FIG. 3, a first fluid injection valve assembly 74 is provided at the lower end of each buoyancy cell 31 and a second fluid injection valve assembly 76 is provided at the upper end of each buoyancy cell 31. As best shown in FIG. 4, each of the valve assemblies 74, 76 preferably includes two fluid transfer valves 78, 80 and a pilot signal transfer conduit 82. The fluid transfer valves 78, 80 and pilot signal conduit 82 each communicate through the wall of the central access tube 62 via corresponding ports 78a, 80a, 82a. A ballast-deballast tool 84 is used to inject gas or ballast liquid through the appropriate injection valve assembly 74, 76 into a desired buoyancy cell 31. Means are provided to monitor the position of the tool 84 so that it can be located precisely across from the appropriate one of the two valve assemblies 74, 76 of any buoyancy cell 31. The tool 84 can be provided with an ultrasonic transducer or other means for establishing the gas-liquid interface in each buoyancy cell 31. This facilitates identifying buoyancy cells 31 which are partially or totally flooded.
The ballast-deballast tool 84 is supported within the central access tube 62 by an umbilical 86 extending from the tool 84 to a surface control station positioned on the main body of the TLP 24. A pilot signal conduit 88, a gas flow conduit 90 and a ballast liquid flow conduit 92 extend through the umbilical 86 to corresponding ports 88a, 90a, 92a extending through the lateral surface of the ballast-deballast tool 84. These ports 88a, 90a and 92a correspond in sequence and separation to the port sets 78a, 80a, 82a associated with each of the valve assemblies 74, 76.
Use of the ballast-deballast tool 84 may be illustrated by an operation to flood the lowest tether section 12 with ballast liquid prior to initiating tether removal. The ballast-deballast tool 84 is lowered through the central access tube 62 from a tool entry port 96 (FIG. 5) at the upper end of the tether 10 to the second fluid injection valve assembly 76. After the tool 84 has been situated so that the tool ports 88a, 90a, 92a are at the same elevation as the corresponding tether wall ports 78a, 80a, 82a, tool packers 94 are activated to place the corresponding port pairs in sealed fluid communication, as shown in FIG. 4. The pilot conduit 88 is pressurized, opening the two fluid transfer valves 78, 80. Ballast liquid is then injected through the ballast liquid flow conduit 92 into the buoyancy cell 31 through the corresponding fluid transfer valve 80. The gas within the buoyancy cell 31 is forced out of the buoyancy cell 31 through the other fluid transfer valve 78 and passes to the surface through the gas flow conduit 90. Once the level of ballast fluid reaches the level of the upper fluid transfer valve 78, the pilot conduit 88 is depressurized, closing the fluid transfer valves 78, 80. The packers 94 are then deactivated and the ballast-deballast tool 84 is withdrawn from the central access tube 62.
In a second version of the central access tube embodiment of the present invention, the second fluid injection valve assembly 76 is deleted. In deballasting a selected buoyancy cell 31, the ballast-deballast tool 84 is lowered to the appropriate first fluid injection valve assembly 74. After activating the packers 94, the liquid flow conduit 92 is depressurized and the gas flow conduit 90 is pressurized. This forces the ballast liquid out of the buoyancy cell 31 through the liquid flow conduit 92 to the surface and replaces the ballast liquid with gas. To ballast a selected buoyancy cell 31, ballast liquid is pumped through the liquid flow conduit 92 into the buoyancy cell 31 while maintaining pressure on the gas flow conduit 90. The gas within the buoyancy cell 31 cascades upward through the differential pressure valves 34.
It should be recognized that in most applications of the present invention it is unnecessary to ever introduce ballast liquid into any portion of the tether other than the lowermost one or two buoyancy cells 31. In this class of tethers each fluid injection valve 74, except those of the lowermost one or two buoyancy cells 31, could be adapted solely for gas injection. The fluid injection valves 74 of the lowermost one or two buoyancy cells 31 would be adapted for transferring either gas or ballast liquid to and from the corresponding buoyancy cells 31.
The internal pressure of the central access tube 62 is maintained at a higher pressure than the external pressure imposed on the central access tube 62 along the full length of the central access tube 62. This ensures that should a leak develop in the central access tube 62, the air within the buoyancy cells 31 will not vent. This is achieved by filling the central access tube 62 with a ballast liquid having a density substantially equal to that of seawater, and maintaining the level of this liquid some distance above the mean seawater level. This is accomplished within a header tank system 97 such as that diagrammatically illustrated in FIG. 5. A ballast liquid filled header tank 98 is situated at the upper end of the tether 10 and is maintained in fluid communication with the central access tube 62. The header tank 98 serves as a reservoir for the transfer of ballast liquid between the central access tube 62 and the TLP 24. A non-return valve 99 is situated intermediate the header tank 98 and the central access tube 62 to prevent uncontrolled return of ballast liquid from the central access tube 62.
The header tank system 97 is provided with a flow meter 104 and integrating flow rate monitor 106 for monitoring the instantaneous rate and cumulative magnitude of ballast liquid flow between the header tank 98 and central access tube 62. In normal operation of the tether 10 no flow should exist. The existence of a flow is indicative of a leak from the central access tube 62 into a buoyancy cell 31. Means 102 are also provided for detecting gas release into the central access tube 62. This is useful for detecting gas leakage from a buoyancy cell 31 into the central access tube 62.
The preferred embodiment of the present invention and the preferred methods of using it have been detailed above. It should be understood that the foregoing description is illustrative only, and that other means and techniques can be employed without departing from the full scope of the invention as set forth in the appended claims.
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A pressure balanced tether buoyancy system 12 useful for reducing the load imposed on a tension leg offshore platform 24 by the tethers 10 securing it to the ocean bottom. The tether 10 has tubular tether walls 11 defining a central cavity 15 isolated from the surrounding seawater. A series of bulkheads 25 extend laterally across the interior of the tether 10, dividing it into a series of individual buoyancy cells 31. Each bulkhead 25 is provided with a differential pressure valve 34 establishing selective fluid communication between the two buoyancy cells 31 separated by the bulkhead 25. Preferably, each differential pressure valve 34 is adapted to open in response to a differential pressure across the bulkhead 25 exceeding the differential hydrostatic existing across the vertical distance separating adjacent bulkheads 25. This permits a pressure gradient to be established interior to the tether 10 approximating that of the seawater in which the tether 10 is located. A central access tube 32 can be provided interior to and extending the length of the tether 10. The central access tube 32 can be used to pass tools through the tether 10 and to ballast and deballast individual buoyancy cells 31.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No. 09/577,167, filed May 24, 2000. This application is also related to U.S. Provisional Patent Application: Application No. 60/189,929, filed Mar. 16, 2000, entitled “Continuously Tunable Graphic Internet Navigation Too,” by applicants James Cole, Medea Minnich, and Mark Donnelly. The teachings of these applications are incorporated herein by reference to the extent that they do not conflict with the teaching herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to data processing systems and methods that use interconnected networks. More particularly, this invention relates to a system and method for providing a continuously tunable, graphic Internet navigation tool.
[0004] 2. Description of the Related Art
[0005] In the past decade there has been an explosive growth in the use of the globally-linked network of computers known as the Internet. This growth has been fueled, in large part, by the introduction and widespread use of so-called “web” browsers, such as Internet Explorer (provided as part of the Windows operating system from the Microsoft Corporation), or the Navigator program available from EarthLink, Inc. Such browsers allow for simple graphical user interface (GUI)-based access to network servers, which support documents formatted as so-called “web pages”.
[0006] The “World Wide Web” (WWW) is that collection of servers of the Internet that utilize the Hypertext Transfer Protocol (HTTP). HTTP is a known application protocol that provides users access to files (which can be in different formats such as text, graphics, images, sound, video, etc.) using a standard page description language known as Hypertext Markup Language (HTML).
[0007] HTML provides basic document formatting and allows the developer to specify “links” to other servers and files. Use of an HTML-compliant client browser involves specification of a link via a Uniform Resource Locator or “URL” (e.g., www.census.gov). Upon such specification, the client makes a request to the server identified in the link and receives a “web page” (namely, a document formatted according to HTML) in return.
[0008] According to the networking protocol for the WWW (i.e., TCP/IP networking protocol), each URL has an associated numeric, Internet Protocol (IP) address. The IP address denotes both the server machine, and the particular file or page on that machine. Meanwhile, the URL functions as a mnemonic from the user's standpoint, offering generally some degree of sensible correlation with the page's identity.
[0009] Associated with the WWW are a number of web server sites functioning as “search engines” which provide access to indexed (e.g., web page creator supplied keywords) information to locate web pages that are of interest to a user. In general, these search engines search large, proprietary databases for matches against a set of user supplied keywords. A list of web pages which match the user's supplied keyword search is then returned to the user's web browser. The list of matching web pages is presented by the web browser program on the user's computer display as a list of links to the matching web pages. The user, in order to discover the nature or characteristic of the resulting links, must open the web page and examine it, often requiring several stages of time-consuming, link tracing to make a determination as to the value of the result.
[0010] U.S. Pat. No. 5,982,369 to Sciammarella attempts to provide a method for avoiding this time-consuming step of opening various, retrieved or found web pages that may be relevant to a searcher's interests. Rather than provide a listing of found web pages, this invention provides, in one embodiment, on a computer screen a plurality of actual, scaled versions of the searched for and found web pages, with the scaling of the size of the different pages being relative to a computed relevance (e.g., the most relevant page has the most matches with the searched for “word”) of a specific web page. Since the possibly relevant web pages are already opened, one can then “zoom in” or magnify their scaled versions to see clearly its actual content. Note that this invention doesn't really try to give a searcher anything other than some relevance information pertaining to a web page before the searcher is required to “zoom in” and examine the actual content of a web page.
[0011] While this “listing of possibly relevant web pages” method is adequate in many instances where explicit keyword terms are available, specifically where well-defined searches are undertaken, it does not provide the user with any of the intuitive or associative information relating to a particular search. Additionally, this method does not provide well for an exploratory mode of database searching in which the searcher is just generally searching and reacts by temporarily suspending the search when he/she comes across a particular site of interest; as, for example, one does in tuning a radio receiver to search until a radio station of interest is found.
[0012] Further contrasting the typical Internet search with a broader, more exploratory type of searching, it is seen that, in the typical Internet search, the user must first enter explicit keyword information, then observe the results of that search (generally a list of possible website containing the keyword), then individually inspect various of the listed websites to determine their relevance to the searcher's interests. Meanwhile, in the exploratory, radio tuning situation, a searcher may tune continuously through the given radio spectrum, and is presented with audible cues to the nature of the program content at each station. This searcher may then easily skip radio stations that are of no interest, with little time investment in further examining such stations.
[0013] From this comparison, it can be noted that the prior art of WWW database searching does not extend to include this type of exploratory searching. Although so-called “artificial intelligence” techniques have variously been applied to Internet search methods, they do not, in general, present the user with a significant departure from traditional search methods in which the search output is a list of potential sites of interest.
[0014] A key means for attempting to increase the efficiency of WWW keyword searching is the use of meta-tags. Meta-tags are a kind of instruction to the computer reading a web page. They always go in the header (between the<head>tags) of a page. The use of meta-tags can provide web page creators with a means to retain some control over how their page is indexed in the various search engine databases. For example, meta-tags may be chosen for their value in characterizing a web page more generally than a singular keyword. However, even with such choices, the overall effectiveness of meta-tags for searching purposes still appears to be limited by the fact that current WWW browsers do not generally permit a wide range of meta-tag format and content.
[0015] The WWW constitutes an unusual database that differs greatly from those upon which the original browsing or searching techniques were developed. The WWW is extraordinarily vast and varied; it is certainly not focused or constrained by any enterprise's subjects of interest.
[0016] When a database is relatively constrained in its content, for example, when it has been created by a manufacturer to track its inventory, it is useful and customary for the database user to rely upon explicit search terms, and the user generally expects similarly constrained results. However, on the WWW, users' interests and search purposes cover a vast range, and a user's foreknowledge regarding appropriate search terms or likely results is likely to be much vaguer. This suggests the need for WWW search methods that do not require the inputting of keywords.
[0017] The prior art of searching for specific web pages generally involves the use of names or URL's rather than the numeric IP address. This is done both for convenience and due to the lack of appropriate navigation tools that might exploit the value of using, in some instances, the numeric address.
[0018] Manipulation of IP addresses for the purpose of mapping a network of computers has been used. In such cases, the objective has usually been to produce a comprehensive overview of the nature and extent of various pages on the network, thereby forming a “map” of the network. Such exercises represent long-term and relatively static applications of direct IP address manipulation, and a client or user does not directly control the address manipulation. Nonetheless, IP address manipulation, or “IP tuning,” appears to offer an opportunity for broad Internet exploration, if such a technique could be coupled with an appropriate user interface.
[0019] Thus, there exists a need to provide a WWW user and searcher with a navigation tool which more fully accommodates the vastness of the WWW, and which permits a searcher to comprehend more fully the potential results of his/her search efforts.
[0020] 3. Objects and Advantages
[0021] Recognizing the need for the development of improved Internet navigation tools, the present invention is generally directed to satisfying the needs set forth above and overcoming the disadvantages identified with prior art devices.
[0022] It is an object of the present invention to provide a method and system for navigating the Internet that overcome the limitations and problems identified with prior methods and systems.
[0023] It is another object of the present invention to meet the need in this field for an interactive, Internet navigation tool which requires less user foreknowledge regarding appropriate search terms or likely search results.
[0024] It is a yet another object of the present invention to provide a method and system for navigating the Internet that will yield greater user satisfaction.
[0025] It is a further object of the present invention to provide a method and system for navigating the Internet that will enhance a user's searching and navigation efficiency.
[0026] These and other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying drawings and the detailed description that follows.
SUMMARY OF THE INVENTION
[0027] The present invention is generally directed to satisfying the needs set forth above and overcoming the limitations and problems identified with prior WWW navigation tools.
[0028] In accordance with one preferred embodiment, the present invention's improvements to a basic client-server system are seen to comprise: (a) means for generating a plurality of related keywords in response to a user-entered keyword, and inputting these keywords to a search engine for identification and retrieval of the web page characterizing information for those web pages having stored, indexed information which matches the inputted keywords, (b) means for utilizing the retrieved, web page characterizing information to generate multi-media expressions for each of these web pages, wherein these expressions allow a user to understand the contents of these web pages without the user having to open the web pages, (c) means for utilizing the retrieved, web page characterizing information to generate and display a plurality of icons representative of these web pages, wherein when a user selects a specific icon, the multimedia expressions associated with that icon and web page are communicated to the user, and (d) means for allowing a user to turn a dial that effectively provides the user with the capability to continuously move thru these displayed icons and their understanding-providing, multi-media expressions so as to efficiently tune to those web pages of interest.
[0029] The present invention is seen to overcome the limitations of the prior art by providing the Internet user an easy, intuitive means for searching and, importantly, more broadly exploring the WWW. This present invention provides a user with a suggestive, multimedia representation of WWW search and exploration opportunities, without the traditional “list” results common to other Internet navigation tools.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates a computer network in which the present invention may be implemented.
[0031] FIG. 2 is a block diagram illustrating a client-side computer system in which the present invention may be implemented.
[0032] FIG. 3 illustrates an embodiment of the present invention in the form of an improved Internet navigation system operating in an “expanded keyword searching” mode of operation.
[0033] FIG. 4 illustrates the relationship between a user's inputted keyword and the server expansion of the keyword into a greater list of keywords.
[0034] FIG. 5 illustrates a lexicon look-up algorithm appropriate for expanding the keywords based an initial, user-inputted keyword.
[0035] FIG. 6 illustrates a type of graphic display generated by the present invention.
[0036] FIG. 7 illustrates an alternative type of graphic display generated by the present invention.
[0037] FIG. 8 provides a legend for the icons presented in FIG. 6 .
[0038] FIG. 9 illustrates the essential features of a linear dial mechanism that may be used as part of the present invention.
[0039] FIG. 10 illustrates an embodiment of the present invention in the form of an improved Internet navigation system operating in an “IP tuning” mode of operation.
[0040] FIG. 11 illustrates a type of graphic display generated by the present invention.
[0041] FIG. 12 illustrates the flow diagram for an “IP tuning” method of Internet navigation.
[0042] FIG. 13 illustrates the flow diagram for an “expended keyword searching” method of Internet navigation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] For purposes of explanation and not limitation, specific details are set forth below, such as specific software engines, software interfaces, display features, and control procedures, in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well known methods, hardware devices, network protocols, operating system platforms, etc. are omitted so as not to obscure the description of the present invention with unnecessary detail.
[0044] Additionally, it should be understood that the present invention may be applied to any navigation application on any type of network including public networks such as the Internet and private networks such as a network accessible only by a certain company's employees, etc. Thus, for example, both Internet web sites and Intra-Nets web sites can be effectively navigated using the present invention. Reference to the Internet throughout the description therefore is meant only as a convenient, non-limiting example of a network.
[0045] Referring now to the drawings wherein are shown preferred embodiments and wherein like reference numerals designate like elements throughout, there is shown in these drawings the various aspects of a continuously tunable, graphic Internet navigation system and method.
[0046] As represented in FIG. 1 , the Internet is a known computer network based on the client-server model. Conceptually, the Internet comprises a large network of servers which are accessible by clients, typically users of personal computers, through some private Internet access provider (e.g., Internet America) or an on-line service provider (e.g., America On-Line). Each of the clients may run a browser, which is a known software tool used to access the servers via the access providers. A server operates a so-called “web site” which supports files in the form of documents and web pages. A network path to a server is identified by a URL having a known syntax for defining a network connection.
[0047] FIG. 2 shows a block diagram of a representative client-side computer in which the present invention is implemented. Such a computer includes a system bus or plurality of system buses to which various components are coupled and by which communication between the various components is accomplished. The microprocessor or central processing unit (CPU) is connected to the system bus and is supported by read only memory (ROM) and random access memory (RAM) also connected to system bus. The ROM contains among other code the Basic Input-Output system (BIOS) which controls basic hardware operations such as the interaction and the disk drives and the keyboard. The RAM is the main memory into which the operating system and application programs are loaded. The memory management chip is connected to the system bus and controls direct memory access operations including, passing data between the RAM and hard disk drive and floppy disk drive. The CD ROM, also coupled to the system bus, is used to store a large amount of data, e.g., a multimedia program or large database.
[0048] Also connected to this system bus are various I/O controllers: the keyboard controller, the mouse controller, the video controller, and the audio controller. The keyboard controller provides the hardware interface for the keyboard, the controller provides the hardware interface for the mouse (or other point and click device), the video controller is the hardware interface for the display, and the audio controller is the hardware interface for multimedia speakers. A modem enables communication over a network to other computers over the computer network.
[0049] Implementation of the present invention in the form of an Internet navigation system, may comprise, depending upon which of the various modes of operation of the system is selected, some or all of the following elements: (1) a client-side computer program which presents search results in the form of a panoramic, graphical display of identified web entities, along with various, associated multimedia expressions which serve to provide more information about these entities without a searcher actually having open their web pages, (2) a server-side computer program which optionally generates keyword expansions for entered keywords and couples or interfaces this expansion set to established search engine, input formats, (3) a client-side computer program which selects or generates IP address sequences based upon an initial user input, and couples these address sequences to established browser input formats, and (4) a rotary or other continuously selectable dial for user input of a search selection parameter or manipulation of the graphical display of search results.
[0050] Thus, in what will be referred to as its “expanded keyword searching” and “IP tuning” modes of operation, it will seen that the client-side, IP addressing software program and the server-side software program, respectively, are not needed. Thus, the present invention may, in some ways, be considered to be a collection of elements that may be variously configured depending upon the invention's desired mode of operation.
[0051] FIG. 3 illustrates an embodiment of the present invention in the form of an improved Internet navigation system operating in an “expanded keyword searching” mode of operation. The present invention's improvements to a basic client-server system are seen to comprise: (a) means 10 for generating a plurality of related keywords in response to a user-entered keyword, and inputting these keywords to a search engine for identification and retrieval of the web page characterizing information for those web pages having stored, indexed information which matches the inputted keywords, (b) means 12 for utilizing the retrieved, web page characterizing information to generate multi-media expressions for each of these web pages, wherein these expressions allow a user to understand the contents of these web pages without the user having to open the web pages, (c) means 14 for utilizing the retrieved, web page characterizing information to generate and display a plurality of icons representative of these web pages, wherein when a user clicks-on a specific icon, the multimedia expressions associated with that icon and web page are communicated to the user, and (d) means 16 for allowing a user to turn a dial that effectively provides the user with the capability to continuously move thru these displayed icons and their understanding-providing, multi-media expressions so as to efficiently tune to those web pages of interest.
[0052] An example of the means 10 for generating a plurality of related keywords in response to a user-entered keyword is shown in FIG. 4 which illustrates the relationship between a user's inputted keyword and the server expansion of the keyword into a greater list of keywords based upon a lexicon look-up algorithm, as shown in FIG. 5 .
[0053] The graphic displays generated by the present invention in this “expanded keyword searching” mode of operation may take many various forms. For illustrative purposes, some of these forms are shown in FIGS. 6-7 . These graphic displays are electronically drawn upon the screen of the client-side computer using conventional and well-established graphic display techniques.
[0054] FIG. 6 shows a type of graphic display which illustrates a panorama of web entities (e.g., web pages) indicated by icons across the user's monitor screen. A legend for such icons is given by way of example in FIG. 8 . Horizontally across the screen are arranged expressions of web entities which have been identified by a search engine as related to, via expansions of the keyword search term, the initial keyword term itself. A pointer 20 is a user-movable indicator that selects a specific icon or expression from across the panoramic display 22 . In this example, the keyword “music” is used as the launch or seed keyword which is inputted into a search engine. The panoramic display shows a range of web entities that correlate with either the keyword or the expansion set of keywords.
[0055] Beneath the horizontal display is a window 24 that depicts in considerably more detail the nature and characteristic of the selected web entity. The details making up the window depiction are culled from either expansion of key terms by the client-side computer, from applets associated with the selected web entity, or from specific data taken from the meta-tags associated with the web entity.
[0056] As the user moves the pointer 20 across the panoramic display 22 , the window 24 depicts in some detail the web entity and the user may make a judgment as to the interest or relevance to his/her desired search. This judgment may be made without the user having to explicitly open the web page itself. Additionally, as the pointer 20 is moved across the panorama by the user, sound elements which relate to the key terms, applet, or meta-tags as interpreted or expanded by the client-side software are presented to the user as a further representation of the nature and characteristic of the web entity selected.
[0057] In this example, the pointer 20 is shown selecting a particular website from the panorama and the corresponding multimedia expression is depicted in the window 24 , in this case showing a guitar icon, which was derived from a meta-tag associated with the website selected. Text and hypertext links are also shown in the window 24 . This gives the user an immediate indication of the nature or characteristic of the website without having to open it and drill down through it.
[0058] FIG. 7 illustrates another possible manner of presenting keyword search term relevance. In this case, the degree of relevance, extrapolated from keyword occurrence within meta-tags, is presented as a histogram or as a probability distribution curve, 26 . This gives the user an intuitive and immediate indication of the extent of relevant web entities that correlate to the given search term. The distribution may be based, for example, upon the number of occurrences of the keyword, the proportion of keyword matches relative to other meta-tags, the completeness of the keyword occurrence, or other parameters.
[0059] In this example, the keyword “personal” is the launch or seed keyword, and the window 24 is shown displaying a home page applet with some associated text. The applet is culled from the web site.
[0060] Associated with the graphic displays of the present invention is a means 16 (e.g., a dial or rotary selector) that permits a user to move between the various search and exploration opportunities presented by the present invention. While the same functionality may be implemented by a standard, computer mouse, the intuitive and continuous nature of the display format is enhanced by a continuous-motion dial or linear selector.
[0061] FIG. 9 illustrates the essential features of such a linear dial mechanism that may be used as part of the present invention. Knob 30 is a manually controlled rotary selector that is mechanically coupled to, in the embodiment shown, an optical encoder 32 . Circuitry 34 is included which converts this encoded pulse stream to a communication protocol similar to or compatible with a computer mouse such that the client computer may use the dial position input from the user to position the apparent position of the pointer 20 . A representative illustration of the overall mechanism is shown by 36 . Various pushbuttons 38 are included to permit the user to perform selections apart from the rotary dial, such as zooming, skipping, and marking web entities shown on the panoramic display.
[0062] The present invention is seen to overcome the limitations of the prior art by providing the Internet user an easy, intuitive means for searching and, importantly, more broadly exploring the WWW. This present invention provides a user with a suggestive, multimedia representation of WWW search and exploration opportunities, without the traditional “list” results common to other Internet navigation tools.
[0063] Such multimedia expressions provide a user with clues or indicators as to the nature or characteristics of the related web pages or other web entities. These clues or indicators are automatically presented to a user without the user having to explicitly open a given web page. Such clues are created within a user's computer by converting or extrapolating identifying features of a web page (e.g., meta-tags) so as to present information regarding the web page as icons, sounds, and applets to help reveal to the user the nature of the web page.
[0064] In what is identified herein as its “IP tuning” mode of operation, the present invention provides a means for finding Internet entities or websites by a user's manipulation of the IP addresses used by the associated browser. By incrementally modifying an initially inputted IP address, a user is able to select and further observe the characterizing information of those web pages having IP addresses which differ only incrementally from that of the initially inputted IP address. Again, the graphic display of a user's computer communicates this characterizing information as multimedia expressions which are similar to the previously described graphic display, except that in this mode (IP tuning) there is not expected to be functional or other relationship between the displayed web pages.
[0065] Since under TCP/IP networking protocol, Internet addresses are numbered using four-byte sequences or “dotted quad” in which each network node or web entity has a unique numeric address and wherein these addresses may be arranged to some extent such that specific bytes of the four-byte address relate to sub networks, the IP tuning capability of the present invention permits a user to select portions of the four-byte address field to manipulate, in a sense analogous to course and fine tuning.
[0066] In this mode of operation, the present invention provides a means for a user to initiate an automatic linear scanning or randomized IP address selection. In this manner, a user may search or explore the WWW without the constraint of having to have sufficient knowledge of desired search results so as to be able to enter appropriate keywords.
[0067] FIG. 10 illustrates an embodiment of the present invention in the form of an improved Internet navigation system operating in an “IP tuning” mode of operation. The present invention's improvements to a basic client-server system are seen to comprise: (a) means 40 means for generating a plurality of IP addresses based upon an initial, user-inputted IP address, (b) means 42 for directing the retrieval from a network server of stored, indexed information pertaining to the IP addresses, (c) means 44 , utilizing said retrieved information, for generating multi-media expressions for each of the IP addresses which allows a user to understand the contents of the web pages associated with the IP addresses without a user having to open the web pages, (d) means 46 , utilizing the retrieved information, for generating and displaying a plurality of icons representative of the IP addresses, wherein when a user clicks-on an icon, the multimedia expressions are communicated to the user, (e) means 48 for allowing a user to turn a dial that effectively provides the user with the capability to continuously move thru these displayed icons and their understanding-providing, multi-media expressions so as to efficiently tune to those web pages of interest.
[0068] FIG. 11 illustrates a manner of presenting a panorama of web entities when the invention is operated in this “IP tuning” mode of operation. In this case, the base IP address is shown in window 50 , while the range of IP addresses in the panorama is indicated by indices 52 along the horizontal axis of the display. In this case, as in the previous examples, a window 54 is displayed that is associated with the panoramic display to give the user a more detailed depiction of the nature or characteristic of the selected web entity.
[0069] As the pointer 56 is moved across the panorama by the user, sound elements, which relate to the key terms, applet, or meta-tags as interpreted or expanded by the client-side software, are presented to the user as a further representation of the nature and characteristic of the web entity selected. In this example, no keyword is required for launch, but rather the mechanism for web page selection is through direct IP address manipulation. Base addresses are entered via a keyboard, then incrementally adjusted by means of a rotary dial or mouse direction controls.
[0070] It should also be recognized that a further embodiment of the present invention can take the form of methods for enabling a computer user to navigate the Internet.
[0071] The flow diagram for such an “IP tuning” method is shown in FIG. 12 and is seen to comprise the steps of: (a) generating a plurality of IP addresses based upon an initial, user-inputted IP address, (b) directing the retrieval from a search engine server of indexed information pertaining to each of the generated IP addresses, (c) generating, utilizing the retrieved information, multi-media expressions for each of the generated IP addresses, (d) generating and displaying, utilizing the retrieved information, a plurality of icons, each of which is representative of one of the generated IP addresses, and (e) communicating at least one of the multimedia expressions to the user when the user selects a specific icon.
[0072] A similar flow diagram for an “expanded keyword searching” method is shown in FIG. 13 and is seen to comprise the steps of (a) generating a plurality of related keywords in response to a user-inputted keyword, (b) inputting this plurality of related keywords to a search engine for identification and retrieval from the search engine's database of characterizing information for those web pages having indexed information which matches with the inputted keywords, (c) generating, utilizing the retrieved information, multi-media expressions for each of the matched web pages, (d) generating and displaying, utilizing the retrieved information, a plurality of icons, each of which is representative of one of the matched web pages, and (e) communicating at least one of the multimedia expressions to the user when the user selects a specific icon.
[0073] The foregoing descriptions of the invention have been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and combined with the skill or knowledge in the relevant art are within the scope of the present invention.
[0074] The preferred embodiments described herein are further intended to explain the best mode known of practicing the invention and to enable others skilled in the art to utilize the invention in various embodiments and with various modifications required by their particular applications or uses of the invention. It is intended that the appended claims be construed to include alternate embodiments to the extent permitted by the current art.
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The present invention discloses a system and method of searching, exploring or otherwise navigating the contents of a collection of networked documents or pages. In a preferred embodiment, this system provides a user with a multimedia display format which intuitively indicates, without the user opening a document or web page, the characteristics of the document or web pages. Additionally, this system permits a user to move between such documents without extensively entering explicit search terms. With this system, the contents of Internet web pages may be evaluated by incrementally adjusting through a multimedia display of a continuum of related web pages, which are identified as having keywords that match any of a collection of keywords generated from an initially-inputted keyword. This system further comprises a dial or rotary control that allows the user to select, in a continuous fashion, among such displayed, Internet web pages.
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BACKGROUND OF THE INVENTION
Virtually all bicarbonates which are produced by crystallization from a carbonating vessel have traces of carbonate reactant on the crystal surfaces of the product bicarbonate (e.g., sodium bicarbonate and potassium bicarbonate). Eliminating residual carbonate is beneficial to reduce the tendency of the bicarbonate to form lumps and to meet some customer purity requirements. However, known ways to remove the residual carbonate are costly or inefficient.
PRIOR ART
The process of converting the residual carbonate on the bicarbonate to additional bicarbonate product is known in the industry as "curing." Curing, of course, increases the purity of the bicarbonate product. Bicarbonate salts, particularly sodium bicarbonate, were formerly cured in bins with dry CO 2 . However, the reaction took days and even then remained incomplete.
Hawliczek's U.S. Pat. No. 574,089, granted Dec. 29, 1896, discloses the treatment of a crude sodium bicarbonate first with steam to hydrate it and then with carbon dioxide. Behrens' U.S. Pat. No. 835,771, granted Nov. 13, 1906, describes a vapor phase process for the manufacture of sodium bicarbonate by treating anhydrous sodium carbonate with a gaseous mixture containing equimolar proportions of carbon dioxide and steam. To avoid condensation of the steam, Behrens described carrying out his reaction under elevated pressures and in the presence of nitrogen.
Gaseous phase, dry carbonation techniques have been disclosed for the production of alkali metal bicarbonates. Many dry carbonation processes involve the addition of liquid water, which can only be added at some risk of over-wetting. For example, Krieg et al. U.S. Pat. No. 4,459,272, owned by the assignee of the present invention, describes a dry carbonation in which liquid water is added to the reaction medium to increase the reaction rate and control the reaction temperature. On the other hand, Sarapata et al. U.S. Pat. No. 4,664,893, also owned by the assignee of the present invention, discloses a process for the preparation of a bicarbonate sorbent in flue gas desulfurization, utilizing a flue gas stream containing from 6 to 17% carbon dioxide and having a relative humidity of at least 90%.
It has long been known to produce potassium bicarbonate in solution from potassium chloride, potassium carbonate or other reactants. See, for example, U.S. Pat. Nos. 1,254,521; 1,400542; 1,636,710; 2,752,222; 2,768,060; 2,782,093; 2,837,404; 2,903,337; 3,111,379; 3,141,730; 3,158,440; 3,189,409; 3,347,623; and 4,010,243.
U.S. Pat. No. 4,919,910 describes the dry carbonation of potassium carbonate to produce potassium bicarbonate, in which the relative humidity of the carbon dioxide stream to the reactor is controlled at from 40 to 70%. In the present invention, the carbon dioxide stream to the reaction zone is saturated with water vapor. In the invention, one controls the drop in temperature between the temperature of the carbon dioxide saturated with water vapor entering the reactor and the temperature of the humid carbon dioxide exiting the reaction zone, thereby condensing the stoichiometric amount of water required for curing. The procedure of U.S. Pat. No. 4,919,190 will not work for the curing of sodium bicarbonate because the sodium carbonate impurity is not deliquescent as is potassium carbonate. In addition, it is stated in U.S. Pat. No. 4,919,910, "Above 75% RH, the carbonation goes to completion but the product formed is difficult to handle and must be dried." [See col. 2, lines 45-47.] It is therefore surprising that the process of the invention results in dry cured sodium and potassium bicarbonate products that are free-flowing and easy to handle. The bicarbonate feed for the process of the invention is generally dry and the cured bicarbonate is also dry. However, if the bicarbonate feed for the process is slightly moist, it is possible that the cured bicarbonate will be drier than the bicarbonate feed--a truly surprising occurrence.
This invention relates to a process for the curing of bicarbonate salts and, more particularly, for reducing the amount of reactant carbonate salt on the surface of the bicarbonate that is produced by crystallization from the carbonating reaction vessel or by any other means. The invention also relates to a dry carbonation technique for reacting the carbonate on the bicarbonate with carbon dioxide and condensed water vapor to produce the bicarbonate in substantially pure dry form.
It is among the objects of the present invention to provide a curing process that does not require the addition of liquid water or operation under conditions that result in the formation of wet reaction products and require increased drying and/or other handling costs. It is an object of the invention to provide a curing process for reducing the amount of reactant carbonate salt on the surface of product bicarbonate salt without adding any liquid water, and thereby improve product purity and reduce caking tendency. It is a further object of the invention to provide a curing process that can be readily added to an existing plant for a relatively modest capital outlay. A further object is to provide a curing process that uses a dry product bicarbonate as the starting material for the process of the invention and produces a dry cured product. It is a still further object of the invention to provide a curing process that has a stable control scheme with a minimal risk of over-wetting the product. It is also an object to provide a process that is relatively quick in accomplishing the foregoing objects. For example, we have operated the process on a continuous basis and achieved residence times on the order of 10 to 12 minutes.
These and other objects and advantages of the present invention will be apparent from the following description.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a process for curing, or reducing the amount of residual carbonate having the formula M 2 CO 3 on a bicarbonate having the formula MHCO 3 , wherein M is an alkali metal, particularly sodium or potassium, which comprises the steps:
(a) feeding the dry bicarbonate into a reaction zone,
(b) introducing into the reaction zone carbon dioxide gas saturated with water vapor at a temperature T 1 controlled as described in step (d),
(c) turbulently mixing the bicarbonate and the carbon dioxide gas saturated with water vapor,
(d) measuring the temperature T 2 of the carbon dioxide stream leaving the reaction zone and controlling temperature T 1 so as to result in a drop in temperature from T 1 to T 2 that is calculated to condense a controlled amount of water vapor sufficient to supply exactly enough water to accomplish the reaction but no detrimental excess,
(e) and reacting the bicarbonate, carbon dioxide, and water vapor, in the substantial absence of liquid water, for a sufficient time to produce dry cured bicarbonate product with less carbonate content and not requiring a separate drying step.
High conversions of the residual carbonate to the desired bicarbonate are achieved, with the bicarbonate being produced in dry form. The reaction may be carried out under atmospheric pressure, thereby avoiding the necessity of utilizing any high-pressure equipment. Moreover, additional capital investment and/or energy expenses for materials handling or drying of the bicarbonate product are unnecessary.
Among the many advantages of the invention may be cited:
A. The process of the invention may be easily added to an existing plant for a low capital outlay.
B. The process of the invention uses dry bicarbonate as the starting material and produces a purer dry bicarbonate product.
C. The process of the invention uses a stable temperature control scheme and as a result there is minimal risk of over-wetting the product.
D. The process of the invention is relatively rapid; in many cases it can be accomplished in only 10 to 12 minutes residence time for the bicarbonate in the reactor.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more fully described in connection with the preferred embodiments described below and in the accompanying FIG. 1, which is a flow diagram of one embodiment of the process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The curing process of the invention converts residual carbonate on bicarbonate salts to additional bicarbonate without waste and at high efficiency. The following reaction occurs in the process of the invention:
M.sub.2 CO.sub.3 +CO.sub.2 +H.sub.2 O→2 MHCO.sub.3,
wherein M is an alkali metal, e.g., sodium or potassium. For the sake of simplicity in the above reaction, the carbonate salt is denoted as having the formula M 2 CO 3 . However, the carbonate may be in the form of other salts such as the sesquicarbonate salt, Wegscheider's salt, the monohydrate salt or the calcined ash. The key to the process of the invention is adding exactly enough water to accomplish the reaction but no detrimental excess. This is accomplished by controlling the temperature of the humid CO 2 used in the reaction. The CO 2 is saturated with water at a temperature T 1 , which is controlled to be higher than the temperature T 2 in the reaction zone so as to condense out the exact amount of water needed in the reaction to convert carbonate to bicarbonate. The CO 2 gas is recirculated between the bicarbonate contacting equipment and a wet scrubber, which removes any dust and also humidifies the CO 2 gas. The temperature of the gas leaving the bicarbonate contactor [e.g., a blender] is measured, and scrubber temperature is controlled so that the CO 2 gas entering the contactor is a known temperature higher than the CO 2 leaving. That temperature difference causes the condensation of the stoichiometric amount of water vapor required for the reaction, because the CO 2 is substantially saturated at all times. A programmable controller measures gas flow and both temperatures T 1 and T 2 and controls temperature T 1 so that the temperature drop from T 1 to T 2 results in the condensation of enough water vapor to provide the exact amount of water needed to effect curing without wetting the product. Usual reaction times for the process of the invention are about 10 to 12 minutes for substantial throughputs.
The bicarbonate feed to the reactor is usually at ambient temperature or it may be at a temperature slightly higher than ambient if it is fed to the curing reactor directly after a carbonation reaction. In theory, there is no limitation on the temperatures that may be employed in the curing reaction of the invention. However, in ordinary practice, T 1 may be controlled at a temperature of from about 30° C. to about 60° C., and T 2 may vary from about 2° C. to about 10° C. lower than T 1 .
The reaction is carried out in the presence of excess amounts of carbon dioxide and water vapor. From the excess carbon dioxide, some of the carbon dioxide reacts to cure the bicarbonate; the unreacted carbon dioxide exits the reactor and is recycled. From the excess water vapor, the stoichiometric amount of water necessary to cure the bicarbonate is condensed for reaction with the carbonate on the surface of the bicarbonate; the unreacted water vapor exits the reactor with the carbon dioxide and is recycled. It is unnecessary to incorporate inert gases in the reaction medium. On the other hand, if desired, the feed gas may contain up to about 75% by volume air, nitrogen, or other inert gas.
The carbonation is carried out under turbulent mixing conditions to insure thorough contact of the dry bicarbonate particles containing residual carbonate with the gaseous reactants in order to cure the bicarbonate, with the condensation of a controlled amount of water. The water required for the reaction is thus entirely provided from the gas phase. The desired turbulent mixing system may be provided by use of any conventional reactor providing gas-solid contact turbulence, e.g., fluidized bed reactors, mechanically agitated reactors, e.g., blenders such as plow blenders, ribbon blenders or high shear mixers, pneumatic conveyors, classifying mills, or even bucket elevators and the like. The process may instead be carried out in particle size reduction or classification equipment.
Although the process of the invention may be conducted in batchwise fashion, possible difficulties in controlling the reaction leads one to the conclusion that it is preferred to conduct the process continuously. The process in which the reaction is conducted in a continuous manner may be controlled by a programmable temperature controller which:
A. receives (a) input from a temperature sensor indicating the temperature of the carbon dioxide saturated with water vapor that enters the reaction zone, (b) input from a temperature sensor indicating the temperature of the humid carbon dioxide that exits the reaction zone, (c) input from a flow controller indicating the flow of the carbon dioxide saturated with water vapor that enters the reaction zone, and
B. controls the temperature of a wet scrubber used to recycle the humid carbon dioxide from the reaction zone so that the stoichiometric amount of water vapor required for the reaction condenses in the reaction zone corresponding to the flow sensed and the difference in the temperature of the carbon dioxide saturated with water vapor that enters the reaction zone and the temperature of the humid carbon dioxide that exits the reaction zone, thereby curing the bicarbonate in the reaction zone.
A preferred continuous process for conducting the process of the invention is illustrated in FIG. 1 and described as follows.
FIG. 1 is a schematic flow diagram of one embodiment of the invention. Dry bicarbonate is fed from hopper 1 through feed conduit 2 to plow blender 3, which has an internal agitator, not shown, that is turned by motor 4. Preferably, the bicarbonate feed has particle sizes of from about 20 to 1000 microns. CO 2 saturated with water vapor at temperature T 1 (sensed by temperature sensor 5) from scrubber 6 is introduced to the plow blender 3 through conduit 7 by blower 8. In plow blender 3, the temperature of the CO 2 saturated with water vapor drops from T 1 to T 2 . That drop in temperature causes the stoichiometric amount of water required in the reaction to condense. That condensed water and some of the CO 2 react with the carbonate on the surface of the bicarbonate feed to yield a cured dry bicarbonate. Dry cured bicarbonate exits the plow blender 3 through conduit 9. Unreacted humid CO 2 at temperature T 2 (sensed by temperature sensor 12) exits the plow blender 3 through conduit 10, which conducts it back to the scrubber 6.
Programmable temperature controller 11 (TC) receives signals indicating plow blender 3 inlet gas temperature T 1 (sensed by temperature sensor 5), plow blender 3 outlet gas temperature T 2 (sensed by temperature sensor 12), and inlet saturated CO 2 gas flow from flow controller 13 (FC) through control circuitry 14, shown by dashed lines. Programmable temperature controller 11 (TC) contains an algorithm, based on psychrometry, which is familiar to one skilled in the art. The setpoint provided to the programmable temperature controller 11 (TC) by the operator represents the mass of water to be condensed per hour, and is based on the throughput of bicarbonate feed through plow blender 3 and the carbonate content of the bicarbonate feed determined by analysis. The programmable temperature controller 11 (TC) then adjusts the temperature of scrubber 6 by adjusting steam valve 15 from the steam source. Steam valve 15 directs steam to heat exchanger 16. Heat exchanger 16 heats the recycle water from the bottom of scrubber 6 that is pumped to heat exchanger 16 by pump 17 through pipeline 18. From heat exchanger 16, the heated recycle water flows through pipeline 19 to the scrubber nozzle 20 inside at the top of scrubber 6. Water is sprayed through the scrubber nozzle 20 downward and countercurrent to the flow of CO 2 , which enters the scrubber 6 at a lower point. The water spray and the countercurrent flow of CO 2 serve to saturate the CO 2 with water vapor at temperature T 1 . Thus inlet gas temperature T 1 (sensed by temperature sensor 5) is maintained greater than T 2 (sensed by temperature sensor 12) by just enough margin to condense out the prescribed stoichiometrically required amount of water in plow blender 3. Any drifting in outlet temperature T 2 (sensed by temperature sensor 12) or in gas flow (controlled by flow controller 13 [FC]) is automatically compensated for by the programmable temperature controller 11 (TC).
During the course of the reaction, water vapor in the system that is reacted is replaced by makeup water from source 21 and is supplied to pipeline 18 by pipeline 22, and CO 2 in the system that is reacted is replaced by makeup CO 2 from source 23 and is supplied to conduit 7 by conduit 24.
Preferred embodiments for carrying out the process of this invention are described in the following examples. Unless otherwise indicated, all parts and percentages given in the examples or in the preceding description are specified by weight and all temperatures are given in degrees Celsius.
EXAMPLE 1
The process employed was substantially as depicted in the schematic flow diagram of FIG. 1 and as described above in the discussion of FIG. 1. A plow blender was used for the gas-solid contact.
Sodium bicarbonate containing no detectable moisture and about 0.3% carbonate was fed to the process at a rate of several tons per hour. Although no effort was made to control bicarbonate or blender temperature, temperature T 2 remained in the range of from 35° to 50° C.; this temperature floated primarily because of incoming bicarbonate temperature. The controller 11 setpoint was adjusted to condense about 15 pounds of water per hour as was required stoichiometrically. With a constant gas recirculation rate of 125 actual cubic feet per minute (acfm), the controller 11 maintained temperature T 1 about 7° C. higher than temperature T 2 . The sodium bicarbonate thus treated had no detectable moisture, as before, and a carbonate content of about 0.05%.
EXAMPLE 2
The process of Example 1 may be followed to cure other alkali metal bicarbonates that have residual carbonates on their surfaces. For instance, potassium bicarbonate containing residual surface carbonate and no detectable moisture is substituted for the sodium bicarbonate in Example 1 and the process repeated. The bicarbonate that results has greatly reduced carbonate on its surfaces and no detectable moisture.
It will be understood that the specific parameters of the preferred embodiments described hereinabove may be varied without departing from the scope of this invention. Accordingly, the preceding description should be construed as illustrative and not in a limiting sense.
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A process for reducing the amount of residual carbonate on alkali metal bicarbonates which comprises:
(a) feeding a dry bicarbonate into a reaction zone,
(b) admixing the bicarbonate with carbon dioxide gas saturated with water vapor at a temperature T 1 ,
(c) controlling the temperature T 1 so that it exceeds temperature T 2 of the carbon dioxide gas exiting the reaction zone by just enough to condense a controlled amount of water vapor sufficient to accomplish the reaction,
(d) and reacting the bicarbonate, carbon dioxide, and condensed water vapor, for a sufficient time to produce dry cured bicarbonate product with less carbonate content.
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This application claims benefit of Provisional Application. 60/042,106 filed Mar. 26, 1997.
FIELD OF THE INVENTION
The present invention relates to a web finishing section in a paper machine, which finishing section comprises a dryer section comprising one or more dryer groups, a calender arranged after the dryer section and a reel-up arranged after the calender.
The present invention relates to a method for finishing a web in a finishing section of a paper machine, in which the web is dried in a dryer section comprising one or more dryer groups, calendered in a calender arranged after the dryer section and reeled onto a reel spool in a reel-up arranged after the calender.
BACKGROUND OF THE INVENTION
In the prior art embodiments of finishing sections in paper machines, both before the calender and in particular from the calender to the reel-up, the web has long, substantially free or unsupported draws, which increases the length of the finishing section in the paper machine to a substantial extent and requires threading ropes for the threading of the leader of the web. Further, at these draws, various quality measurement devices are arranged for measuring and monitoring the quality of the paper web. Costs have, of course, also arisen from the paper guide rolls required by the draws. Thus, the long draws of the paper web have also required threading ropes and related arrangements of equipment and equivalent, by whose means the leader of the paper web is carried during threading from one stage into the other, which has increased the costs of equipment further.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a finishing section for a paper machine in which the problems described above have been eliminated or at least minimized.
It is a further object of the present invention to provide a finishing section for a paper machine in which the length of the finishing section can be made shorter compared with the finishing sections currently in use.
It is another object of the present invention to provide new and improved methods for finishing a web in a finishing section of a paper machine in which the path of travel of the web is less than in prior art finishing sections.
In view of achieving the objects stated above and those that will come out later, the finishing section in a paper machine in accordance with the present invention comprises a calender placed at least partly underneath the reel spool storage space of the reel-up so that the reel-up is placed substantially directly after the calender. In this manner, the web is passed directly from the calendering nip onto the reel cylinder or to a substantially short distance from the calender, the web being passed over one guide member that supports and/or spreads the web onto the reel cylinder.
The arrangement in accordance with the present invention permits a ropeless threading, because there are no long unsupported draws, in which case, for threading, it is possible to use, for example, guide plates and/or equivalent suitable for full-width transfer of the web. For example, in an application in which the calender is a belt calender and the reel-up is a belt reel-up, ropeless threading can be arranged particularly simply so that the web is passed from the last drying cylinder in the dryer section by means of guide plates or equivalent directly onto the belt in the belt calender, on whose belt the web is passed through the calendering nips and further onto the belt in the belt reel-up. One belt calender is described in the current assignee's Finnish Patent Application No. 931021, and one application of a belt reel-up is described in the current assignee's Finnish Patent Application No. 935669.
The arrangement in accordance with the present invention is partly made possible by the fact that, at present, various quality meters are in themselves known whose size is considerably smaller than the size of meters that were in use earlier, in which case such meters can be arranged in a simple way in connection with a calender, in particular with a soft calender, and/or with a reel-up without a separate support construction provided for such meters.
By means of an arrangement in accordance with the invention, considerable economies of length are obtained in the finishing section, which economies of length correspond, for example, to a distance in which a group consisting of six drying cylinders can be accommodated, in which case, the capacity of the dryer section can be increased without changing the overall length of the machine. On the other hand, with the same overall length, the production rate can be increased, for example, from about 615 tons to about 735 tons per day, or the speed from about 1500 meters per minute to about 1800 meters per minute, which corresponds to an increase in production of about 16 percent. Of course, owing to the present invention, it is also possible to construct a machine of shorter length, compared with the prior art, with unchanged capacity, in which case, economies can be obtained, for example, in the costs of construction of the paper machine hall, which costs in themselves constitute a major cost item, since the cost per meter of a paper machine hall is about one million Finnish marks.
By means of an arrangement in accordance with the invention, modernizations of existing paper machines in view of increasing their capacity are also made possible, which modernizations could not be carried out earlier because of lack of space.
In the arrangement in accordance with the invention, the short web draws after the calender permit a full-width threading of the web based on what is called the "coanda effect", because the exclusively airborne support and guiding of the web, which is difficult to control over unduly long distances, can be reduced to a minimum.
In the arrangement in accordance with the invention, economies are also obtained in the paper guide rolls (2 rolls), and just one pulper is needed, because a common pulper can be used for the dryer section and for the reel-up as the distance between them becomes shorter.
If cooling of the web is needed between the calender and the reel-up, it is possible to use various cooling devices in themselves known, such as a blow box.
The advantages of the present invention are manifested particularly well in a combination of a soft calender and a reel-up marketed by the assignee under the trademark Optireel™, which reel-up is described in more detail, e.g., in the current assignee's Finnish Patent Application No. 905284 (corresponding to U.S. Pat. No. 5,251,835, incorporated by reference herein).
A method for finishing a web in a finishing section in a paper machine in accordance with the invention comprises the steps of drying the web by passing the web through a dryer section having at least one dryer group, then calendering the dried web after the dryer section by passing the web through a calendering nip defined by a pair of rolls, then reeling the calendered web in a reel-up by passing the web over a reel cylinder onto a reel spool, and storing empty reel spools for use in the reel-up in a reel spool storage space defined above the calendering nip. The web may be supported in a run between the calendering nip and the reel cylinder by means of a single guide roll. The calender may be arranged substantially directly after a last one of the at least one dryer group in the dryer section in a running direction of the web, the last dryer group possibly being a twin-wire draw dryer group or a single-wire draw dryer group.
The invention will be described in detail with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawing. However, the invention is not confined to the illustrated embodiments alone.
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. 1A is a schematic illustration of a prior art paper machine arrangement, in which the last group in the dryer section is a dryer group with twin-wire draw;
FIG. 1B is a schematic illustration of a finishing section in an arrangement in accordance with the present invention in which, as in FIG. 1A, the last group in the dryer section is a dryer group with twin-wire draw;
FIG. 2A is a schematic illustration of a prior art arrangement of a finishing section in a paper machine, wherein the last group in the dryer section has been arranged as a group with single-wire draw; and
FIG. 2B is a schematic illustration of a finishing section in accordance with the present invention in which, as in FIG. 2A, the last group in the dryer section is a dryer group with single-wire draw.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, corresponding reference numerals refer to corresponding parts, and the letter symbol A added after a reference numeral refers to the prior art arrangements.
In the prior art arrangement shown in FIG. 1A, the last dryer group RA N in the dryer section in the finishing section makes use of twin-wire draw, after which group the web is passed as a draw 26A to a soft calender 20A, which is followed by a second draw of the web 25A, supported by paper guide rolls 27A, to a reel-up 30A. Pulpers 41A and 42A of the dryer section and the reel-up 30A, respectively, are placed below the machine level in the so-called basement space.
In the twin-wire draw in the dryer group RA N , endless wires 10A, 11A run while being guided by guide means, such as guide rolls 16A, 17A, over drying cylinders 12A, 13A and reversing rolls 14A, 15A in the manner of twin-wire draw. The web has free draws between the rows of drying cylinders 12A,13A, as in a standard twin-wire draw dryer group. From the dryer group RA N , the paper web is passed over a guide roll 28A as the draw 26A into a first calendering nip NA 1 in the calender 20A. The web is passed from the first calendering nip NA 1 , into a second calendering nip NA 2 , and from there as the draw 25A over the guide rolls 27A to the reel-up 30A. The storage space for reel spools in the reel-up 30A is denoted by reference numeral 33A, the reel spool change devices are denoted by reference numeral 34A, the reel cylinder is denoted by reference numeral 31A, the paper reel that is being formed is denoted by reference numeral 32A, and the complete machine reel is denoted by reference numeral 35A.
As shown in FIG. 1B, the length of the finishing section in the paper machine in accordance with the invention is shorter so that the draws 26A,25A between the last dryer group R N and the soft calender 20 and between the soft calender 20 and the reel-up 30 have become substantially shorter. Specifically, to accomplish this, the reel spool storage space 33 of the reel-up 30 is placed above the soft calender 20 entirely above the calendering nip N 1 , and the pulpers of the dryer section and of the reel-up are combined into a single pulper 41. In the dryer group R N , the drying wires are denoted by reference numerals 10,11, and they run, guided by guide means such as guide rolls 16,17, over drying cylinders 12,13 and reversing rolls 14,15. Between the rows of drying cylinders 12,13, the web has free draws. From the last drying cylinder, the web is passed as a short draw over a roll 28 into a first calendering nip N 1 in the calender 20, from which it is passed into a second calendering nip N 2 . The web is passed over a single roll 37 past a quality meter 29 and then passed over a reel cylinder 31 to be reeled as a paper reel 32. The reel spool storage space in the reel-up 30 is denoted by reference numeral 33, the reel spool change device is denoted by reference numeral 34, and the complete machine reel is denoted by reference numeral 35.
As exemplified by the comparison of FIGS. 1A and 1B, economies of length are achieved in the arrangement in accordance with the invention, i.e., it is shorter. By way of example, it can be stated that in an embodiment of the invention, the economies of length L 1 in a transition from an arrangement as shown in FIG. 1A into an arrangement as shown in FIG. 1B are about 7650 mm.
FIG. 2A is a schematic illustration of a prior art arrangement for a finishing section in a paper machine, in which the last dryer group RA N in the dryer section is a dryer group with single-wire draw. The pulper 41A of the last dryer group RA N is placed in the basement space. From the last dryer group RA N , the paper web is passed as the draw 26A to the soft calender 20A, where it is calendered from both sides in calendering nips NA 1 , NA 2 , after which the web is passed to the reel-up 30A, where a machine reel 32A,35A is formed out of the web. In the dryer group RA N in the dryer section, the drying wire is denoted by reference numeral 50A, the wire guide rolls are denoted by reference numeral 51A, the drying cylinders are denoted by reference numeral 52A, and the vac rolls in the lower row with the reference numeral 53A. The paper web to be dried runs, in the single-wire draw, from the drying cylinders 52A onto the reversing rolls 53A while constantly supported by the drying wire 50A. After this, the run of the web onward is similar to the arrangement shown in FIG. 1A. In the embodiment shown in FIG. 2A, a quality measurement device 29A is arranged between the calender 20A and the reel-up 30A.
In the schematic illustration of the embodiment shown in FIG. 2B, the finishing section in the paper machine has been made shorter in accordance with the invention, in which connection the draw 26 from the dryer section to the soft calender 20 has been made slightly shorter and the draw from the soft calender 20 to the reel-up 30 has been eliminated completely as the reel spool storage space 33 in the reel-up 30 is placed above the soft calender 20, whereby considerable economies of space are achieved. The dryer group R N is a dryer group with single-wire draw, in which the paper web runs on the support of the drying wire 50 from the drying cylinders 52 in the upper row onto the vac rolls 53, which are placed in the lower row. The wire 50 guide rolls are denoted by reference numeral 51. The draw in the final part of the finishing section is substantially similar to that described above in relation to FIG. 1B.
In a transition from the arrangement of FIG. 2A to the arrangement of FIG. 2B, the economies of length L 2 that are achieved are, for example, about 6300 mm.
In accordance with the invention, when the finishing section is made shorter, the upper roll of the second nip N 2 in the soft calender 20 can be raised from the machine directly upwards through the reel spool storage space 33, which results in an easy and quick replacement of the roll, i.e., the production efficiency of the machine is increased as the time taken by the change of the roll becomes shorter. In the reel spool storage space 33 above the roll, parts, for example latches or equivalent, are opened and permit lifting of the roll through the frame system of the reel spool storage space 33. The frame system of the reel spool storage space 33 is supported on the to floor level by means of columns of its own from outside the frame system of the soft calender 20 in order to avoid detrimental effects of oscillations in the soft calender 20. The frame system is supported from both of its ends in the machine direction. By means of the operations described above, easy and quick change of roll is achieved in the soft calender 20, and oscillation-free storage 33 is obtained for the reel spools. Spreading of the effects of formation of dust that may occur in the reel-up 30 to the calender 20 is prevented by, if necessary, constructing an air jet and/or a detachable shield wall (not shown) between the calender 20 and the reel-up 30. A quality measurement beam is constructed between the columns placed between the calender 20 and the reel-up 30 in an integrated way in consideration of attenuation of vibrations. For the reel-up 30 and for the calender 20, just one pulper 41 is needed, which is installed so that the web can be passed from the dryer section R N , from the calender 20 and from the reel-up 30 into the pulper 41. Chutes 45 of the pulper 41 are designed sufficiently long and, if necessary, the pulper 41 is mounted sufficiently far down below in order to provide an inclination downwards. The frame of the reeling equipment 30 is separate from the frames of the reel spool storage space 33 and the calender 20, in which case vibrations and resonance of different components are avoided.
In FIGS. 1B and 2B, some preferred exemplifying embodiments are illustrated of the web finishing section in accordance with the invention in a paper machine. This is, of course, not supposed to confine the invention to such finishing sections alone, but variations of many other, different types are also possible. For example, instead of the cylinder dryer groups illustrated in the figures, the dryer groups can be constructed, for example, by employing a dryer concept based on the heat pipe effect (CONDEBELT), by means of airborne web dryers, dryers based on infrared radiation, etc. Of course, the reel-up and the calender shown in the figures can also differ from the embodiments illustrated in the figures. For example, instead of a soft calender it is possible to use calenders of different types, a machine stack, a supercalender, etc.
Above, some preferred embodiments of the invention have been described, and it is obvious to a person skilled in the art that numerous modifications can be made to these embodiments within the scope of the inventive idea defined in the accompanying patent claims. As such, the examples provided above are not meant to be exclusive. 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.
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A web finishing section in a paper machine including a dryer section having one or more dryer groups, a calender and a reel-up. The calender is placed at least partly underneath the reel spool storage space of the reel-up so that the reel-up is placed substantially directly after the calender, in which case, the web is passed directly from the calendering nip onto the reel cylinder or to a substantially short distance from the calender, the web being passed over one guide member that supports and/or spreads the web onto the reel cylinder. A method for finishing a web is also described.
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CLAIM OF PRIORITY
This is a continuation of application Ser. No. 10/822,514, filed Apr. 12, 2004, now U.S. Pat. No. 7.018,146, which is a continuation of application Ser. No. 10/355,774, filed Jan. 31, 2003, now U.S. Pat, No. 6,736,410, which is a continuation of application Ser. No. 10/074,290, filed Feb. 12, 2002, now U.S. Pat. No. 6,536,781, which is a continuation of application Ser. No. 09/907,266, filed Jul. 17, 2001, now U.S. Pat. No. 6,367,815, which is a continuation of application Ser. No. 09/443,629, filed Nov. 19, 1999, now U.S. Pat. No. 6,279,918, which is a continuation of continued prosecution application Ser. No. 08/903,679, filed Jul. 31, 1997, now U.S. Pat. No. 6,068,266, which is a continuation of application Ser. No. 08/472,181, filed Jun. 7, 1995, now U.S. Pat. No. 5,709,392, which is a continuation of application Ser. No. 08/289,922, filed Aug. 12, 1994, now U.S. Pat. No. 5,501,473, which is a continuation-in-part of application Ser. No. 08/106,063, filed Aug. 13, 1993, now U.S. Pat. No. 5,348,317 the entire disclosures of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type which may be tightened or loosened by hand or by actuation of the driver motor.
Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools used with such drivers, the tools may also comprise screwdrivers, nut drivers, burrs, mounted grinding stones and other cutting or abrading tools. Since the tools may have shanks of varying diameter or the cross-section of the tool shank may be polygonal, the device is usually provided with a chuck which is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore.
A wide variety of chucks have been developed in the art. In the simplest form of chuck, three jaws spaced circumferentially approximately 120 degrees apart from each other are constrained by angularly disposed passageways in a body attached onto the drive shaft and configured so that rotation of the body in one direction relative to a constrained nut engaging the jaws forces the jaws into gripping relationship with respect to the cylindrical shank of a tool, while rotation in the opposite direction releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. One example of such a chuck is disclosed in U.S. Pat. No. 5,125,673 entitled “Non-Impact Keyless Chuck” commonly assigned to the present assignee, and whose entire disclosure is incorporated by reference herein.
Despite the success of keyless chucks such as set forth in U.S. Pat. No. 5,125,673, varying configurations of chucks are desirable for a variety of applications. Currently utilized in a variety of chuck applications are ball bearings for reducing friction between the nut and body from axial thrust of the nut onto the body. These bearings are sometimes caged and have separate top and bottom thrust races. Sometimes the body or the nut, if hard enough, can serve as the bottom or top thrust race, respectively. It would be desirable to have a keyless chuck that requires fewer components or lower manufacturing or assembly cost. In addition, it would be desirable to have a chuck configuration whereby radial as well as axial thread stresses were minimized when the chuck was operated. Further, it would be desirable to have a chuck whereby the front sleeve is maintained in place by a nosepiece that is both functional and serves an aesthetic purpose.
SUMMARY OF THE INVENTION
The present invention recognizes and addresses the foregoing considerations, and others of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved chuck. It is another object of the present invention to provide a chuck that minimizes radial as well as axial stress during operation. It is another object of the present invention to provide a keyless chuck that has a minimum number of individual components that must be assembled. It is another object of the present invention to provide a chuck with an improved nosepiece that is both decorative and retains the front sleeve in place.
Yet another object of the present invention is to provide an improved mechanism for maintaining a one-piece nut on the body of a chuck.
These and other objects are achieved by providing a chuck for use with a manual or power driver having a rotatable drive shaft, the chuck comprising a generally cylindrical body member having a nose section and a tail section. The tail section has an axial bore formed therein to mate with the drive shaft of the driver, and the nose section has an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. The chuck further includes a plurality of jaws slidably positioned in each of the angularly disposed passageways, each of the jaws having a jaw face formed on one side thereof and threads formed on the opposite side thereof. The chuck further includes a nut rotatably mounted on the body and in engagement with the threads of the jaws and a bearing thrust ring fixed on the body member. The chuck further includes a self-contained anti-friction bearing assembly disposed between the nut and the thrust ring and a generally cylindrical front sleeve member in driving engagement with the nut and overlying the nose section of the body member whereby when the front sleeve member is rotated with respect to the body member, the jaws will be moved thereby.
These and other objects are also accomplished by providing a chuck for use with a manual or power driver having a rotatable drive shaft, the chuck comprising a generally cylindrical body member having a nose section and a tail section, the tail section having an axial bore formed therein to mate with the drive shaft of the driver, and the nose section having an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. The chuck further includes a plurality of jaws slidably positioned in each of the angularly disposed passageways, each of the jaws having a jaw face formed on one side thereof and threads formed on the opposite side thereof. The chuck further includes a nut rotatably mounted on the body and in engagement with the threads on the jaws, and a generally cylindrical front sleeve member overlying the nose section of the body member and in driving engagement with the nut. The chuck further includes a rust-resistant nosepiece adapted to be secured to the nose section of the body, the nosepiece maintaining the front sleeve member in driving engagement with the nut, whereby when said front sleeve member is rotated with respect to the body member, the jaws will be moved thereby.
These and other objects are further accomplished by providing a chuck for use with a manual or powered driver having a rotatable drive shaft, the chuck comprising a generally cylindrical body member having a nose section and a tail section. The tail section is adapted to mate with the drive shaft of the driver and the nose section having an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting said axial bore. The chuck further includes a plurality of jaws slidably positioned in the angularly disposed passageways, each of the jaws having a jaw face formed on one side thereof. The chuck further including a nut rotatably mounted on the body member and in engagement with the threads on the jaws. The chuck further includes a nut retainer member received on the body for maintaining the nut on the body, the nut retainer member including a frusto-conical portion. The chuck further includes a generally cylindrical front sleeve member in driving engagement with the nut and overlying the nose section of the body member whereby when the front sleeve member is rotated with respect to the body member, the jaws will be moved thereby. In a preferred embodiment, the nut retainer member further includes a cylindrical portion which is press fitted onto the body member.
Other objects, features and aspects of the present invention are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
FIG. 1 is a longitudinal view, partly in section, of a chuck in accordance with an embodiment of the present invention;
FIG. 2 is an exploded view of the chuck illustrated in FIG. 1 ;
FIG. 3 is a longitudinal view, partly in cross-section of another embodiment in accordance with the present invention; and
FIG. 4 is an exploded view of the chuck illustrated in FIG. 3 .
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It is to be understood by one of ordinary skill in the-art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary construction.
Referring to FIGS. 1 and 2 , a chuck 10 in accordance with the present invention is illustrated. Chuck 10 includes a front sleeve member 12 , an optional rear sleeve member 14 , a body member 16 and jaws 18 . Body member 16 is generally cylindrical in shape and comprises a nose or forward section 20 and a tail or rearward section 22 . An axial bore 24 is formed in the nose section 20 of the body member 16 . Axial bore 24 is somewhat larger than the largest tool shank that the chuck is designed to accommodate. A threaded bore 26 is formed in tail section 22 of body 16 and is of a standard size to mate with the drive shaft of a powered or hand driver (not shown). The bores 24 , 26 may communicate at the central region 28 of body member 16 . While a threaded bore 26 is illustrated, such bore could be replaced with a tapered bore of a standard size to mate with a tapered drive shaft.
Passageways 30 are formed in body member 16 to accommodate each jaw 18 . Preferably, three jaws 18 are employed and each jaw 18 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 30 and the jaws 18 are angled with respect to the chuck axis but intersect the chuck axis at a common point ahead of the chuck body 16 . Each jaw 18 has a tool engaging face 32 which is generally parallel to the axis of the chuck body 16 and threads 34 on its opposite or outer surface. Threads 34 of any suitable type and pitch may be utilized within the scope of the present invention as would be readily apparent to one skilled in the art.
As illustrated in FIGS. 1 and 2 , body member 16 includes a thrust ring member 36 which, in a preferred embodiment, is integral therewith. Thrust ring member 36 includes a thrust face 38 . Thrust face 38 includes an arcuate seating surface 40 for engagement with the inner race of a self-contained anti-friction bearing assembly 42 as will be described in more detail below. Thrust ring member 36 includes a plurality of jaw guideways 30 formed around the circumference to permit retraction of the jaws 18 therethrough.
Body member 16 includes a rear cylindrical portion 44 with a knurled surface 46 thereon for receipt of optional rear sleeve 14 to be pressed thereon if so desired. Body 16 further includes a first tapered portion 48 extending from rear cylindrical portion 44 to thrust ring 36 . A second tapered portion 50 extends from the area of thrust face 38 to a front cylindrical portion 52 . Front cylindrical portion 52 is of greater diameter than the smaller end of second tapered portion 50 and forms a first circumferential groove 54 intermediate the nose and tail sections 20 and 22 of body 16 . Body 16 further includes a reduced diameter nose portion 56 that is adapted to receive a nosepiece 58 as will be described in more detail below.
The present invention further includes a nut 60 which, in a preferred embodiment, is a split nut and which includes threads 62 for mating with threads 34 on jaws 18 whereby when said nut is rotated with respect to said body, said jaws will be advanced or retracted. Nut 60 is adapted to receive a retaining band 64 for maintaining nut 60 together after it is assembled. In the illustrated embodiment, a split nut is utilized because of the diameter of front cylindrical portion 52 . Nut 60 includes drive slots 66 for mating with drive ribs 68 on front sleeve 12 so that when front sleeve 12 is rotated, nut 60 will rotate therewith and move jaws 18 as set forth above.
A self-contained bearing assembly 42 is adapted to be placed between thrust ring 36 and a face 70 of nut 60 . Self-contained bearing assembly 42 includes an inner race 72 , an outer race 74 and bearing elements 76 maintained therebetween. In a preferred embodiment, bearing elements 76 are ball bearings. Self-contained bearing assembly 42 may further include a shroud 78 surrounding the inner and outer races 72 , 74 for maintaining the bearing assembly as a self-contained component. Inner race 72 includes an arcuate surface that is dimensioned and configured to mate with arcuate seating surface 40 on thrust face 38 of thrust ring 36 . Such mating relationship assists in alignment and minimization of both axial and radial stresses when the chuck is operated. In a preferred embodiment, self-contained bearing assembly 42 is a radial thrust bearing.
Use of a self-contained bearing assembly has a number of advantages. Assembly is greatly simplified in that individual ball bearings and cages do not have to be handled. In addition, the body and nut are not required to be as hard or dense as is necessary with conventional bearing systems where the body or nut may also serve as a thrust race, thus allowing more flexibility in materials and reducing secondary manufacturing operations and, ultimately, cost.
Front sleeve member 12 is adapted to be loosely fitted over nose section 20 of chuck 10 . Drive ribs 68 of front sleeve 12 engage drive slots 66 of nut 60 so that front sleeve 12 and nut 60 will be operatively connected, i.e., when front sleeve 12 is rotated, nut 60 will rotate therewith. Front sleeve 12 includes an annular ledge portion 79 adapted to rest at the inner face of front cylindrical portion 52 and nose portion 56 . Nosepiece 58 is dimensioned and adapted to be pressed onto nose portion 56 to maintain front sleeve 12 on chuck 10 . It should be appreciated that nosepiece 58 could also be secured by snap fit, threading or the like. Nosepiece 58 is exposed when said chuck is assembled and is preferably coated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. In a preferred embodiment, such coating may be zinc or nickel, however, it should be appreciated that any suitable coating could be utilized.
Nosepiece 58 serves to maintain front sleeve member 12 in position on chuck 10 and in driving engagement with nut 60 . In addition, nosepiece 58 serves the dual purpose of providing an aesthetically pleasing cover for nose portion 56 that inhibits rust. This provides the advantage of an aesthetically pleasing appearance without the necessity to coat the entire body member 16 with a non-ferrous material. If desired, the rear sleeve member 14 may be omitted and the front sleeve member 12 extended to the tail end of body 16 . This alternative is feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws.
The circumferential surface of the front sleeve member 12 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. In like manner, the circumferential surface of the rear sleeve member 14 , if employed, may be knurled or ribbed if desired. The front and rear sleeves may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite filled polymerics would also be suitable in certain environments. As will be appreciated by one skilled in the art, the materials from which the chuck of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.
It will be appreciated that rear sleeve member 14 is fixed to body member 16 while front sleeve member 12 is operatively associated with nut 60 and secured to body member 16 for relative rotation therewith. Relative movement of the front and rear sleeve members, 12 and 14 , due to the interaction between threads 34 on jaws 18 and threads 62 on nut 60 causes jaws 18 to be advanced or retracted, depending upon the direction of relative movement.
Referring to FIGS. 3 and 4 , a chuck 110 in accordance with another embodiment of the present invention is illustrated. Chuck 110 includes a front sleeve member 112 , an optional rear sleeve member 114 , a body member 116 and jaws 118 . Body member 116 is generally cylindrical in shape and comprises a nose or forward section 120 and a tail or rearward section 122 . An axial bore 124 is formed in the nose section 120 of the body member 116 . Axial bore 124 is somewhat larger than the largest tool shank that the chuck is designed to accommodate. A threaded bore 126 is formed in tail section 122 of body 116 and is of a standard size to mate with the drive shaft of a powered or hand driver (not shown). The bores 124 , 126 may communicate at the central region 128 of body member 116 . While a threaded bore 126 is illustrated, such bore could be replaced with a tapered bore of a standard size to mate with a tapered drive shaft.
Passageways 130 are formed in body member 116 to accommodate each jaw 118 . Preferably, three jaws 118 are employed and each jaw 118 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 130 and the jaws 118 are angled with respect to the chuck axis but intersect the chuck axis at a common point ahead of the chuck body 116 . Each jaw 118 has a tool engaging face 132 which is generally parallel to the axis of the chuck body 116 and threads 134 on its opposite or outer surface. Threads 134 of any suitable type and pitch may be utilized within the scope of the present invention as would be readily apparent to one skilled in the art.
As illustrated in FIGS. 3 and 4 , body member 116 includes a thrust ring member 136 which, in a preferred embodiment, is integral therewith. Thrust ring member 136 includes a plurality of jaw guideways 150 formed around the circumference to permit retraction of the jaws 118 therethrough. Thrust ring member 136 may have an arcuate seating surface for receipt of a self-contained bearing assembly as described in the above embodiment.
Body member 116 includes a rear cylindrical portion 144 with a knurled surface 146 thereon for receipt of optional rear sleeve 114 to be pressed thereon if so desired.
The present invention further includes a nut 160 which, in a preferred embodiment, is a unitary nut and which includes threads 162 for mating with threads 134 on jaws 118 whereby when said nut is rotated with respect to said body, said jaws will be advanced or retracted. As illustrated in FIG. 4 , nut 160 includes drive slots 166 for mating with drive ribs 168 on front sleeve 112 so that when front sleeve 112 is rotated, nut 160 will rotate therewith and move jaws 118 as set forth above.
A self-contained bearing assembly 142 is adapted to be placed between thrust ring 136 and a face 170 of nut 160 . Self-contained bearing assembly 142 includes an inner race 172 , an outer race 174 and bearing elements 176 maintained therebetween. In a preferred embodiment, bearing elements 176 are ball bearings. Self-contained bearing assembly 142 may further include a shroud 178 surrounding the inner and outer races 172 , 174 for maintaining the bearing assembly as a self-contained component. Inner race 172 may include an arcuate surface that is dimensioned and configured to mate with an arcuate seating surface on the thrust face of thrust ring 136 such as illustrated in the previous embodiment, if so desired. Such mating relationship assists in alignment and minimization of both axial and radial friction when the chuck is operated. In a preferred embodiment, self-contained bearing assembly 142 is a radial thrust bearing. It should be appreciated that any type bearing arrangement including plain bearing surfaces could be utilized in the present invention.
Referring again to FIGS. 3 and 4 , a nut retainer member is generally illustrated at 143 . Nut retainer member 143 includes a first generally cylindrical portion 145 and a second frusto-conical portion 147 . Substantially cylindrical portion 145 is configured to be press fitted over nose or forward section 120 in a location so that a portion 149 will engage nut 160 to prevent nut 160 from moving axially forward more than a desired amount. This desired amount can be determined by the location in which the nut retainer member is pressed onto the body member. It should be appreciated that the nut retainer member 143 is adapted to be press fitted onto the nose portion of the body, but could be secured in any other suitable manner in accordance with the present invention. Nut member 160 defines a ledge 151 and nut retainer member 143 , through its portion 149 , is adapted to be received on ledge 151 when contact is made between nut 160 and nut retainer member 143 .
Front sleeve member 112 is adapted to be loosely fitted over nose section 120 of chuck 110 . Drive ribs 168 of front sleeve 112 engage drive slots 166 of nut 160 so that front sleeve 112 and nut 160 will be operatively rotationally connected, i.e., when front sleeve 112 is rotated, nut 160 will rotate therewith.
A nosepiece 158 is dimensioned and adapted to be pressed onto the front of the forward section 12 Q of body member 116 to maintain front sleeve 112 on chuck 110 . It should be appreciated that nosepiece 158 could also be secured by snap fit, threading or the like. Nosepiece 158 is exposed when the chuck is assembled and is preferably coated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. In a preferred embodiment, such coating may be zinc or nickel, however, it should be appreciated that any suitable coating could be utilized.
Nosepiece 158 serves to maintain front sleeve member 112 in position on chuck 110 and in driving engagement with nut 160 . In addition, nosepiece 158 serves the dual purpose of providing an aesthetically pleasing cover for nose portion 156 that inhibits rust. This provides the advantage of an aesthetically pleasing appearance without the necessity to coat the entire body member 116 with a non-ferrous material. If desired, the rear sleeve member 114 may be omitted and the front sleeve member 112 extended to the tail end of body 116 . This alternative is feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws.
It should also be appreciated that a snap ring or any other mechanism could be utilized to maintain front sleeve 112 in place in lieu of nosepiece 158 .
The circumferential surface of the front sleeve member 112 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. In like manner, the circumferential surface of the rear sleeve member 114 , if employed, may be knurled or ribbed if desired. The front and rear sleeves may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite filled polymerics would also be suitable in certain environments. As will be appreciated by one skilled in the art, the materials from which the chuck of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.
It will be appreciated that rear sleeve member 114 is fixed to body member 116 while front sleeve member 112 is operatively associated with nut 160 and secured to body member 116 for relative rotation therewith. Relative movement of the front and rear sleeve members, 112 and 114 , due to the interaction between threads 134 on jaws 118 and threads 162 on nut 160 causes jaws 118 to be advanced or retracted, depending upon the direction of relative movement.
While the above description is set forth with respect to a keyless chuck, it should be appreciated that the principles of the present invention may be equally applicable to a keyed chuck, and such is within the scope of the present invention.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary a skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention so further described in such appended claims.
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A chuck for use with a manual or powered driver including a generally cylindrical body having a nose section and a tail section. The tail section defines an axial bore formed therein to mate with the drive shaft of the driver and the nose section defines an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. A plurality of jaws is slidably positioned in each passageway and each jaw defines a jaw face formed on one side and threads formed on the opposite side. A nut is disposed about the body for rotational movement with respect to the body and is in driving engagement with the jaw threads. A generally cylindrical front sleeve overlays the nose section of the body. A generally cylindrical nut retainer is disposed about the body and includes a frusto-conical portion.
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PRIORITY INFORMATION
This application claims the benefit of U.S. Provisional Application No. 60/580,576, filed on Jun. 17, 2004.
FIELD OF THE INVENTION
The field of this invention relates to drilling a wellbore and more particularly a monobore in a single trip before installing a casing or liner.
BACKGROUND OF THE INVENTION
The traditional way to drill a well involves starting with a large bore and drilling ever decreasing bores below so that a new section of casing can fit through the casing already run and cemented. In this technique, as each segment is drilled there is what is called flat time or time when no drilling is going on. Instead, time, which costs the operator money, is taken up tripping the drill bit out of the hole and running in each size of casing.
One more recent alternative to this well used technique is a monobore completion. In this type of well drilling a single size hole is drilled from the surface to total depth. Even with this technique, unless the productive interval is relatively shallow, any time a problem zone is breached in the drilling, the drilling has to stop and the bit pulled out of the hole so that casing or liner can be run to isolate the problem zone so that drilling can resume. This technique is necessary because the mud weight is the sole means of well control during this type of drilling and the problem zone needs to be isolated with cemented casing or liner before drilling can resume safely.
Another known technique is to drill with a downhole motor powered by flow from coiled tubing going through a lubricator for well control. Although a bore can be continuously drilled this way, it is limited to rather small bore sizes.
Accordingly for the larger bores, even the monobore technique does not reduce the flat time from tripping in and out of the bore as each section of casing or liner is run in after a segment of the monobore is drilled.
What is needed is a technique that allows the ability to deal with problem zones of any type while drilling so as to isolate them without having to pull the bit out of the hole. This problem is addressed for applications where drilling with a downhole motor and coiled tubing through a lubricator will not produce the required bore diameter. The technique involves being able to isolate the zone with the drill string and bit still in the hole in a manner that allows drilling to resume as the zone is isolated. In part the solution involves the use of composite memory materials to be delivered with the drill string or subsequently over it when the troublesome zone is encountered. Local application of energy or heat activates the material to another shape to seal the troublesome zone and, if previously attached to the drill pipe, to release from it to allow drilling to resume. This general description will be more readily understood by those skilled in the art from a review of the description of the preferred embodiment and the claims, both of which appear below.
SUMMARY OF THE INVENTION
Drilling a well to total depth without tripping the bit out of the hole despite encountering a troublesome zone is made possible by using a memory based composite material delivered with the drill pipe or advanced over it, as needed. The material can be activated as a troublesome zone is encountered and assumes as former configuration that places it in sealing relation to the troublesome zone in the bore hole while spacing it from the drill pipe so as to allow resumption of drilling with the troublesome zone isolated.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a run in view of the preferred embodiment showing the composite sleeves in position;
FIG. 2 shows one sleeve activated to seal against a troublesome zone and clear of the drill string;
FIG. 3 shows an additional sleeve in position against the zone;
FIG. 4 shows another sleeve in position against the troublesome zone;
FIG. 5 is an alternate embodiment in the run in position during drilling;
FIG. 6 shows the drilling reaching a troublesome zone and a sleeve being delivered from above to near the bottom hole assembly; and
FIG. 7 shows the sleeve actuated against the troublesome zone and away from the drill string to allow drilling to continue.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a drill string 10 just reaching a problem zone 12 in a wellbore 14 . The drill bit is at the lower end of the drill string and is omitted from FIGS. 1-4 . Those skilled in the art will appreciate that the drill bit can be coupled with an under-reamer to expand the drilled hole produced by the bit, in a known manner. Mounted to the drill string 10 to one or more stands of pipe are a sleeve 16 . This sleeve is made from an elastic memory composite material and is commercially available from Composite Technology Development Inc of Lafayette, Colo. This company describes this product and its current attributes and applications as follows:
Elastic Memory Composite (EMC) materials are based on thermoset shape memory polymers, which enable the practical use of the shape memory properties in fiber-reinforced composites and other specialty materials. The applications for these revolutionary new materials are broad ranging, including mission-enabling components for spacecraft, performance enhancing and cost saving industrial and medical applications, deployable equipment for emergency and disaster relief, and improvements in the performance of sports equipment.
EMC materials are similar to traditional fiber-reinforced composites except for the use of an elastic memory thermoset resin-matrix. The elastic memory matrix is a fully cured polymer, which can be combined with a wide variety of fiber and particulate reinforcements and fillers. The unique properties of the matrix enable EMC materials to achieve high packaging strains without damage. Strains are induced by elevating the temperature of the EMC material and then applying a mechanical force. The shape memory characteristics enable the high packaging strains to be “frozen” into the EMC by cooling. Deployment (i.e., shape recovery) is effected by elevating the temperature. The temperature at which these operations occur is adjustable.
At lower temperatures, the performance of EMC materials follows classical composite laminate theory. At higher temperatures, EMCs exhibit dramatically reduced stiffnesses due to significant matrix softening of the resin. Adequately addressing the mechanics of the “soft-resin” will enable the EMC materials to provide repeatable stowage and deployment performance without damage and or performance changes. Products fabricated from these materials can be deformed and reformed repeatedly. Products utilizing EMC materials can be fabricated with conventional composite fabrication processes and tooling. EMC Materials:
Can be formulated with low cost components Use standard existing polymer and composite manufacturing processes Regain original shape with applied heat, no other external force is required Possess widely adjustable deformation and reformation temperatures are Are suitable for repeated deformation and reformation cycles Reform accurately to original shape Maintain high strain capability when heated Enable large volume reduction for packing Issues such as shelf life, chemical reaction, toxicity, explosion hazard, or environmental impact are not of concern
Polymers have a characteristic temperature, called the glass transition temperature (Tg), at which the polymer softens. CTD's elastic memory polymer becomes both soft and highly ductile above this transition temperature. Below this temperature the polymer is hard and rigid, or glassy. Above TG the elastic memory polymer can be highly deformed and stretched into a different shape, such as folded into a compact shape. When held in this shape and cooled, it retains the new shape indefinitely. When reheated above TG, the material reforms to its original shape without external force, and regains its original properties once cooled. Thus an EMC tubular structure could be heated, collapsed and stowed, and then later reformed simply by heating.
EMC materials are ideally suited for deployable components and structures because they possess high strain-to-failure ratios, high specific modulus, and low density. By contrast, most traditional materials used for deployable structures have only two of these three attributes.
Initial EMC development efforts have targeted space applications. Tremendous support for the development of CTD's EMC materials has been received from NASA, the Air Force, BMDO and other Government agencies, and the aerospace industry. EMC materials have the potential to enable a new generation of space deployable components and structures, which would eliminate nearly all the limitations and shortfalls of current spacecraft deployable technologies.
With that as a background on the preferred material for the sleeve 16 those skilled in the art will appreciate that the original dimensions for fabrication of sleeve 16 will approximate its desired final dimensions in the wellbore after activation, as shown in FIG. 2 . The outer dimension 18 needs to be large enough after activation, to sit firmly against the troublesome zone 12 in a way that one or more than one sleeve 16 can isolate the zone upon deployment. Rubber end rings could be used to enhance the sealing ability. At the same time, the inner dimension 20 should clear the outside wall 22 of the drill string 10 so that the drill string 10 can be rotated with minimal and preferably no contact to the sleeve or sleeves 16 . After initial forming to these general dimensional specifications, the sleeve 16 can be raised above the glass transition temperature while mounted over a stand of drill pipe so that while in the fluid form its shape can be reconstituted to fit snugly or even loosely over the stand of drill pipe 10 . The reformed exterior dimension 24 , shown in FIG. 1 should preferably be smaller than the bore being drilled either by the bit or by an associated under-reamer. In that way the sleeve 16 will not be damaged by advancement of the bit and will preferably have minimal contact with the borehole wall during drilling. Loosely fitting the sleeve 16 to a stand of drill pipe 10 allows for some relative rotation between them should the sleeve 16 make contact with the borehole 14 during drilling.
Additionally, the activation temperature of the sleeves 16 can be adjusted to be higher than the anticipated well fluid temperature to avoid deployment without introduction of an energy source, schematically labeled E in FIG. 2 to cause transition back to the original shape. FIG. 3 illustrates that two sleeves 16 can be placed next to each other, or three or more as illustrated in FIG. 4 . Sealing material can also be incorporated into one or more sleeves 16 so that when it is activated the sealing is enhanced by the presence of the sealing material, shown schematically as 26 in FIG. 3 .
FIGS. 5-7 illustrate drilling the borehole 14 with a bit 28 and an under-reamer 30 located above it. The sleeves 16 are not in position during drilling. However, when a problem zone 12 is encountered the sleeve or sleeves 16 can be lowered over the drill pipe 10 or expanded from drill pipe 10 as shown in FIG. 6 . An energy source E is delivered through the drill pipe to the vicinity of the sleeve 16 and it resumes its original shape taking its outer wall against the borehole 14 and its inner wall away from the drill string 10 , as shown in FIG. 7 . In this variation of the technique, the sleeve or sleeves 16 can be allowed to travel to near the bottom hole assembly by gravity or with reverse circulation outside the drill string 10 or by use of a direct or indirect force from outside or inside the drill string 10 . Thus whether the sleeve or sleeves are delivered with the drill pipe or inserted in the wellbore 14 after the troublesome zone is encountered, the desired result on activation is the same, isolation with an ability to continue drilling.
It should be noted that more than one troublesome zone 12 can be isolated in the techniques described above. The troublesome zones can be close together or thousands of feet apart. If the sleeves closest to the bottom hole assembly have already been activated to isolate a higher troublesome zone 12 , remaining sleeves on the drill string 10 can be used to isolate another zone further down the bore. If the sleeves 16 are secured to the drill pipe one above the other, it will mean that to isolate a lower zone after an upper zone has been isolated, the drilling will need to continue to position the remaining sleeves opposite the new lowers zone because the lowermost sleeves have been deployed above. The inside dimension of the deployed sleeve or sleeves need to be large enough to allow the remaining undeployed sleeves to pass, as drilling continues. Similarly, if the additional sleeves are to be subsequently delivered from the surface after one zone has already been isolated, then those new sleeves must clear through the previously deployed sleeves as the new sleeves travel down the drill pipe 10 . Alternatively, to the extent space is available, the sleeves can be nested near the bottom hole assembly and constructed to activate at different temperatures with the outermost sleeve activated at the lowest temperature. If done in that manner, several sleeves can be run in with the drill string 10 and while positioned close to the bottom hole assembly. When done this way, there is no need to drill further into a subsequent troublesome zone after an earlier deployment in a higher troublesome zone, as the next available sleeve 16 would already be in close proximity to the bottom hole assembly.
Although elastic memory composite materials are preferred, the invention encompasses a technique that allows isolation of troublesome zones without having to pull out of the hole, thereby allowing drilling to progress until total depth is reached. Other materials and techniques that make drilling to depth without pulling out of the hole while having the ability to isolate one or more troublesome zones is within the scope of the invention.
While the preferred embodiment has been set forth above, those skilled in art will appreciate that the scope of the invention is significantly broader and as outlined in the claims which appear below.
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Drilling a well to total depth without tripping the bit out of the hole despite encountering a troublesome zone is made possible by using a memory based composite material delivered with the drill pipe or advanced over it, as needed. The material can be activated as a troublesome zone is encountered and assumes as former configuration that places it in sealing relation to the troublesome zone in the bore hole while spacing it from the drill pipe so as to allow resumption of drilling with the troublesome zone isolated.
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This is a provisional application No. 60/079,610, filed Mar. 27, 1998.
BACKGROUND OF THE INVENTION
In the renovation and repair of industrial buildings, such as factories and warehouses, it is often necessary to remove existing floor coverings. These floor coverings can be of a great variety of materials, such as rugs, wood, tile, etc. which are secured to a cement floor by high strength adhesive. The removal of such floor coverings is a labor intensive and difficult task. The machines currently available take the form of hand or motor driven scrapers which push a heavy duty scraping blade over the floor to raise the floor covering.
A machine of this type which is designed specifically for tile removal is described in U.S. Pat. No. 5,641,206. The machine of the '206 patent employs an hydraulic cylinder to raise and lower the blade into engagement with the floor. The force distribution requires supplemental weights at the front and back of the machine to increase the force response of the blade and to insure proper traction on the rear wheel. Such machines do not perform efficiently, thereby requiring repetitive passes over the floor.
It is the purpose of this invention to improve the performance of a tile scrapping machine and the overall operation of such machines.
SUMMARY OF THE INVENTION
A machine is designed having a frame articulated along a pivot axis displaced a short distance forward of the wheel axis. The frame consists of a main body and a rear portion. The main body is constructed with an integral blade mounting bracket welded to its forward end. A forward support wheel is mounted for vertical movement on the main body just rearward of the blade. An hydraulic piston is operatively connected to the support wheel to retract the wheel during operation of the scrapper.
The rear frame portion is constructed with a pair of flanges having means to attach the axle for the rear wheels. The flanges extend a short distance both forward and rearward of the axis of the wheels. The main body is pivotally attached to the rear flanges by means of a horizontally extending cylindrical bar just forward of the drive wheel axis. A transverse beam connects the two flanges just behind the axis of the drive wheels. In order to adjust the angle of the blade a second hydraulic cylinder is connected to the transverse beam to exert a moment force on the rear frame portion to pivot the flanges about the wheel axis and thereby raise the rear of the main body.
The main body encloses a reservoir for hydraulic fluid which is pumped to independent drive pumps operatively connected to each wheel. In addition the same fluid is used to operate the front wheel retraction cylinder and the rear blade height adjustment cylinder. A drive pressure is obtained from main drive pumps which may be operated either by a piston engine powered by propane or an electrical motor each being mounted on the main body.
DESCRIPTION OF THE DRAWING
The invention of this application is described in more detail below with reference to the Drawing in which:
FIG. 1 is a front perspective view of a machine employing the features of this invention;
FIG. 2 is a rear perspective view of a machine employing the features of this invention; and
FIG. 3 is an exploded perspective view of the frame of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the figures, the machine of this invention includes a high strength blade element 6 mounted for engagement with the floor to scrape and remove surface materials. The machine consists of a frame 1 constructed in two primary sections, a main body 2 and a rear flange assembly 21 . Body 2 extends forward from the wheels 22 in a substantially horizontal attitude in the non-operational condition, i.e., blade 6 raised above the floor. Body 2 is comprised of a rear pivot support extension 16 , a forward mounting beam 3 and a blade mounting bracket 4 . The assembly of elements comprising the body 2 are welded together to form a rigid support element for the machine. A heavy duty scrapper blade 6 is mounted on the bracket 4 through an optional wedge 5 .
A support castor 8 is mounted on an angle iron 7 which in turn is mounted on the actuating shaft 10 of an hydraulic cylinder 9 . The castor support assembly is therefore retractable upon operation of cylinder 9 . The body 2 encloses an interior reservoir 23 which is filled with hydraulic fluid through spout 12 which is closed by cap 13 .
The rear flange assembly 21 consists of side flanges 17 connected by transverse beam 18 to form a support frame for the axle and wheels 22 . The transverse beam 18 is welded at its ends to each of the flanges 17 to form an integral assembly. The side flanges 17 extend, both forward and rearward, a short distance from the wheel axle 20 . At their forward end, the flanges are pivotally connected to a pivot bar 40 , which is pivotally mounted on the support extensions 16 of the body 2 . In this manner the assembly of body 2 and rear frame 21 form an articulated assembly which pivot about a horizontal axis B just forward of the rotational axis A of the drive wheels 22 , as shown by arrows 37 and 38 .
A vertical frame member 11 extends upward from the body 2 to support a variety of machine elements described below. An hydraulic cylinder 14 having an actuating shaft 15 is connected between the body 2 and the rear frame 21 at the vertical frame member 11 and the transverse beam 18 , respectively. Actuation of the cylinder 14 will extend the actuating shaft 15 , thereby exerting a moment force on the rear of frame 21 , as illustrated by arrow 39 . This force will tend to raise the forward portion of frame 21 with the rear portion of the body 2 and adjust the operational angle Φ of the blade 6 .
As shown in FIGS. 1 and 2 each of the pair of wheels 22 are independently driven by drive pumps 24 . The drive pumps 24 are supplied by main pressure pumps 25 and 26 . Pump 25 is driven by an electrical motor 27 mounted on vertical frame 11 . Pump 26 is driven by piston engine 28 . An electrical supply is connected to electric motor 27 through conduit 29 contained on reel 30 . Reel 30 is mounted on a retractable extension 31 of the vertical frame 11 . A source of propane, tank 35 , is mounted on the vertical frame 11 to power the piston engine 26 .
The hydraulic components are connected through a system of conduits 32 and controlled by a series of control valves 33 operated by manual levers 34 .
The operator sits on the seat 36 mounted on the vertical frame 11 within easy reach of the manual levers 34 . The height of the seat is adjusted to provide the operator with a clear view of the blade 6 during operation.
In operation the source of power is selected, either electrical or propane, and energized. Through the actuation of cylinder 9 , the wheel 8 is retracted to allow the full weight of the machine to be supported on blade 6 . The blade 6 will engage the surface of the floor along an angle Φ and exert a force indicated by force vector F as the drive wheels 22 are driven forward. The angle Φ of force vector F is adjustable through the actuation of cylinder 14 . Depending on the difficulty of the removal operation, the width of the blade may be varied, a narrower blade being used for more difficult tasks. Through the independent drive mechanisms, the rotation of the wheels may be relatively adjusted to steer the machine across the work area.
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A machine for scrapping surface materials from a floor having an articulated structure which allows the adjustment of the angle of the scraper blade by pivot motion of the main body element. A front wheel assembly is retractable to allow the blade to support the machine. A dual power mode is also provided.
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This is a continuation of U.S. patent application Ser. No. 09/852,75 1, filed May 11, 2001, now U.S. Pat. No. 6.432.401, claiming priority from U.S. Provisional Application Nos. 60/203,800 and 60/235,855, filed May 12, 2000 and Sep. 27, 2000, respectively, now abandoned. The entirety of each of these applications is incorporated by reference herein.
FIELD OF THE INVENTION
The invention is in the field of medicinal chemistry. The invention relates in particular to a method of reversing local anesthesia induced by a local anesthetic and an alpha-adrenergic agonist, comprising administering an effective low dose of an alpha-adrenergic antagonist.
RELATED ART
Local anesthesia is widely used by dentists to provide pain relief to patients during dental procedures. To provide pain relief, a drug formulation containing a local anesthetic compound such as lidocaine is injected into the gum tissue surrounding the tooth or teeth on which the dental procedure is to be performed. There are short-acting and long-lasting local anesthetic drug formulations. Short-acting local anesthetic drug formulations contain lidocaine or a related local anesthetic drug dissolved in saline or other suitable injection vehicle. Typically, local anesthesia with short-acting local anesthetics lasts approximately 20-30 minutes, which is not long enough for many dental procedures. To obtain long-lasting local anesthesia, dentists often use lidocaine or other local anesthetic formulations which, in addition to the local anesthetic drug itself, contain low concentrations of epinephrine or another adrenergic receptor agonist such as levonordefrin. More than 90% of the local anesthesia procedures performed by dentists involve local anesthetic formulations containing alpha-adrenergic receptor agonists. The vasoconstrictor is necessary because local anesthetics without vasoconstrictor are too short-acting for most dental procedures. The added epinephrine stimulates alpha-adrenergic receptors on the blood vessels in the injected tissue. This has the effect of constricting the blood vessels in the tissue. The blood vessel constriction causes the local anesthetic to stay in the tissue much longer, resulting in a large increase in the duration of the anesthetic effect (from 20 minutes for the short-acting formulation to 3-6 hours for the long-lasting formulation). A major problem with the use of epinephrine-containing local anesthetics is soft-tissue anesthesia (lip, cheek, tongue) which usually lasts many hours longer than anesthesia and analgesia of the tooth pulp. Tooth pulp anesthesia and analgesia are the desired effects of local anesthesia from a dental procedural perspective while soft-tissue anesthesia is usually an undesirable side effect. Soft tissue anesthesia results in a number of problems and inconveniences, such as a prolonged and uncomfortable feeling of numbness in and around the mouth, inability to smile, difficulty eating, drinking and swallowing, loss of productivity by missing work hours or meetings etc. Lingering soft-tissue anesthesia can be the cause of injuries due to biting of the tongue or lips. Lingering soft-tissue anesthesia can also result in loss of productivity due to missed work hours or meetings etc. Furthermore, lingering soft-tissue anesthesia is an inconvenience and it is perceived as an annoyance by many patients. Lingering soft-tissue anesthesia can lead to injury especially in children who often bite into the anesthetized tissue out of curiosity. It would therefore be desirable to have a drug that could be used at will by dentists to rapidly reverse local anesthesia after it is no longer needed
U.S. Pat. No. 4,659,714 discloses a method of prolonging local anesthesia by coadministering a vasoconstrictor, in particular, a vasoconstrictor that acts upon the alpha-adrenergic receptor sites of the blood vessel walls. The '714 patent also discloses the subsequent administration of an alpha-adrenergic receptor antagonist to cause reduction of the prolonged anesthesia effect. Included within the group of alpha-adrenergic receptor antagonists described in this patent are phentolamine mesylate. However, the examples make reference to the administration of “phentolamine.” It is much more likely that what was administered was phentolamine mesylate since phentolamine mesylate is FDA approved and readily soluble in water. In contrast, phentolamine is not FDA approved and is relatively insoluble in water.
As shown in Example 1, Table 1, 0.5-1.5 mg of “phentolamine” was administered to groups of patients which were pretreated with lignocaine admixed with epinephrine. The results in Table 1 show a reduction in the duration of anesthesia with increasing amounts of “phentolamine.” In Example 2, 2 mg of “phentolamine” was administered. In Example 3, four injections of 1 mg each (4 mg total) of “phentolamine” were administered. In Example 4, four injections of 1 mg each (4 mg total) of “phentolamine” were administered.
The drug doses of “phentolamine” described in the '714 patent (0.5-4 mg) overlap the doses of phentolamine mesylate that are approved by the FDA for the systemic treatment of high blood pressure in patients with pheochromocytoma (total dose of 5 mg in a solution of 2.5-5 mg/ml). Since those doses are normally intended for systemic treatment of high blood pressure, those high dose levels can cause severe side effects when used in healthy, normal people. The package insert of the phentolamine-mesylate product states the following side effect warning: “Myocardial infarction, cerebrovascular spasm, and cerebrovascular occlusion have been reported to occur following the administration of phentolamine, usually in association with marked hypotensive episodes.” Thus, the drug doses taught by the '714 patent for the reversal of local anesthesia may cause unacceptable side effects, precluding the use of this product for anesthesia reversal in healthy normal subjects in a dentist's office.
It has now been discovered that a highly effective local anesthesia reversal can be obtained by injections of much lower concentrations of phentolamine-mesylate than is disclosed in the '714 patent. It has been found that a solution containing only 0.05 mg/ml of phentolamine-mesylate can rapidly reverse the effect of a local anesthetic containing an alpha adrenergic receptor agonist. This phentolamine-mesylate drug concentration is 20-100 times lower than the phentolamine-mesylate drug concentration taught by the '714 patent. The advantage is that, at such low phentolamine-mesylate drug concentrations, no systemic side effects such as myocardial infarction and cerebrovascular spasm will be observed. This allows the safe and effective use of phentolamine-mesylate for local anesthesia reversal without causing life-threatening or other untoward side effects. Indeed, in a human clinical efficacy study using a low-concentration-formulation of phentolamine-mesylate, a highly effective anesthesia reversal was observed without any side-effects whatsoever. Thus, this invention constitutes a crucial improvement of the local anesthesia reversal method taught by the '714 patent.
SUMMARY OF THE INVENTION
The present invention provides compositions and formulations of low concentrations of phentolamine-mesylate and other alpha adrenergic receptor antagonists and use thereof for reversing the effects of long-lasting local anesthetic agents containing alpha-adrenergic receptor agonists.
In particular, the invention relates to a method of providing local anesthesia to a mammal, comprising:
(a) administering to the mammal in need thereof an anesthetic agent and an alpha adrenergic receptor agonist to the site to be anesthetized, wherein said anesthetic agent is administered in an amount effective to provide local anesthesia and said alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels at the site and prolong the local anesthesia, and then (b) administering a low dose of an alpha adrenergic receptor antagonist to said site to reduce the prolongation.
In a preferred embodiment, the invention relates to a method of providing local anesthesia to a human, comprising:
(a) administering to a human in need thereof by injection to the site to be anesthetized a solution comprising polocaine and levonordefrin, wherein said polocaine is administered in an amount effective to provide local anesthesia and said levonerdefrin is administered in an amount effective to constrict the blood vessels at the site and prolong the local anesthesia, thereby producing local anesthesia at said site, (b) carrying out a medical procedure on the human, and then (c) administering phentolamine mesylate at said site at a concentration of about 0.05 mg/ml or less to reduce the prolongation.
The invention also relates to a method of enhancing the survival of a tissue graft, comprising
(a) administering to a mammal undergoing a tissue graft an anesthetic agent and an alpha adrenergic receptor agonist to the site of the tissue graft, wherein said anesthetic agent is administered in an amount effective to provide local anesthesia and said alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels at the site and prolong the local anesthesia, (b) performing the tissue graft procedure, and then (c) administering an alpha adrenergic receptor antagonist to said site to reduce the prolongation and enhance the tissue graft survival.
The invention also relates to a method of providing a regional anesthetic block to a mammal, comprising:
(a) administering to the mammal in need thereof an anesthetic agent and an alpha adrenergic receptor agonist in the site to receive the anesthetic block, wherein said anesthetic agent is administered in an amount effective to provide local anesthesia and said alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels in the site and prolong the anesthetic block, and then (b) administering an alpha adrenergic receptor antagonist to said site to reduce the prolongation.
The invention also relates to a kit comprising a carrier means having in close confinement therein two or more container means, wherein a first container means contains an anesthetic agent and optionally an alpha adrenergic receptor agonist and a second container means contains a low dose of an alpha adrenergic receptor antagonist.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention relates to a method of providing local anesthesia to a mammal, comprising:
(a) administering to the mammal in need thereof an anesthetic agent and an alpha adrenergic receptor agonist to the site to be anesthetized, wherein said anesthetic agent is administered in an amount effective to provide local anesthesia and said an alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels at the site and prolong the local anesthesia, and then (b) administering a low dose of an alpha adrenergic receptor antagonist to said site to reduce the prolongation.
The anesthetic agent and alpha adrenergic receptor agonist may be administered together as part of a unitary pharmaceutical composition or as part of separate pharmaceutical compositions so long as the alpha adrenergic receptor agonist acts to constrict the blood vessels in the vicinity of where the anesthetic agent has been administered to result in a prolonging of anesthesia. In a preferred embodiment, the anesthetic agent and alpha adrenergic receptor agonist are administered together in solution. The anesthetic agent and alpha adrenergic agonist may be administered by injection, by infiltration or by topical administration, e.g. as part of a gel or paste.
In a preferred embodiment, a solution comprising the anesthetic agent and alpha adrenergic receptor agonist is administered by injection directly into the site to be anesthetized, e.g. prior to a dental procedure.
Examples of local anesthetics that may be used in the practice of the invention include without limitation lidocaine, polocaine, lignocaine, xylocaine, novocaine, carbocaine, etidocaine, procaine, prilocaine, bupivacaine, cinchocaine and mepivacaine.
Examples of alpha adrenergic receptor agonists that can be used according to the invention include catecholamines and catecholamine derivatives. Particular examples include without limitation levonordefrin, epinephrine, and norepinephrine.
Examples of alpha adrenergic receptor antagonists that can be used in the practice of the invention include without limitation phentolamine, phentolamine hydrochloride, phentolamine mesylate, tolazoline, yohimbine, rauwolscine, doxazosine, labetolol, prazosine, tetrazosine and trimazosine. Phentolamine-mesylate is approved by the FDA for the treatment of hypertension in patients with pheochromocytoma, for the treatment of dermal necrosis and sloughing following accidental extravasation of norepinephrine, and for the diagnosis of pheochromocytoma (phentolamine blocking test). The drug is supplied in vials containing 5 mg of drug substance which may be dissolved in physiological saline or other pharmaceutically acceptable carrier.
In order to reverse the local anesthesia after a medical procedure according to the present invention, the alpha adrenergic receptor antagonist is administered at a low dose, i.e. at a dose that does not cause side effects, i.e. at or below about 0.25 mg per dose for adults (at or below about 0.0036 mg/kg) or 0.1 mg per dose for children, more preferably, below about 0.1 mg per dose for adults (below about 0.0014 mg/kg) or 0.04 mg per dose for children, most preferably, at about 0.08 mg per dose for adults (about 0.001 mg/kg) or about 0.032 mg per dose for children, of phentolamine mesylate or a molar equivalent of another adrenergic receptor antagonist. In a preferred embodiment, the alpha adrenergic receptor antagonist is present at a concentration of from about 0.001 mg/ml to about 0.25 mg/ml, more preferably, about 0.05 mg/ml to about 0.1 mg/ml.
The alpha adrenergic receptor antagonist may be administered by injection into the site of anesthesia, by infiltration or by topical administration. In a preferred embodiment, the alpha adrenergic receptor antagonist is administered to mucosal tissue. In this embodiment, the alpha adrenergic receptor antagonist may be applied to the site in the form of an impregnated wafer, pellet or cotton ball, whereby the antagonist is taken up by the mucosal tissue resulting in reversal of the anesthesia. In another embodiment, the alpha adrenergic receptor antagonist is administered to the site of a regional anesthetic block to reverse the block, e.g. by injection or infiltration into the site. In a preferred embodiment, the alpha adrenergic receptor antagonist is administered via a cannula into the epidural space of an animal to reverse epidural anesthesia.
Examples of medical procedures that may be carried out according to the present invention include, without limitation, both major and minor surgery, dental procedures, cosmetic surgery, tissue grafting (e.g. hair and bone grafting) and cesarean section. In one embodiment, reversal of anesthesia according to the present invention is carried out by medical trainees to mitigate any mistakes that are made, and which may lead to the loss of extremities such as fingers, as well as ears and tips of noses.
Hyaluronidase, an enzyme which enhances the diffusion of drugs within tissues, may be administered together with the alpha adrenergic receptor antagonist. The hyaluronidase and alpha adrenergic receptor antagonist may be administered together as part of a unitary pharmaceutical composition or as part of separate pharmaceutical compositions, so long as the hyaluronidase and alpha adrenergic receptor antagonist are administered to the site where anesthesia is to be reversed and are present in amounts effective to enhance the diffusion of the alpha adrenergic receptor antagonist and to reverse the anesthesia, respectively. The hyaluronidase is administered one or more times into the site of anesthesia. In general, about 1.5 U to about 200 U of hyaluronidase is administered in one or more injections. In a most preferred embodiment, about 200 U of hyaluronidase is administered by injection into the site. Those of ordinary skill in the art can determine optimal amounts of hyaluronidase with no more than routine experimentation.
When performing hair grafts, the surgeon often injects an anesthetic and epinephrine to reduce bleeding and provide a clear vision of the site. According to Bernstein, R. M. and Rassman, W. R., Hair Transplant Forum International 10:39-42 (2000), the usefulness of epinephrine in hair graft procedures is limited by a number of factors including post-operative telogen effluvium when epinephrine is used in large transplant sessions. In addition, when adrenaline is added to an area whose blood supply is already compromised by a large number of recipient sites, the tissue may not receive enough oxygen. Although not proven, according to Bernstein and Rassman it is likely that epinephrine infiltration into the recipient area is a contributing factor in the development of the “central necrosis” that has occasionally been reported during hair transplantation. Furthermore, it is possible that the intense vasoconstrictive action of epinephrine may contribute to the decreased graft survival. Thus, according to the present invention, one may achieve enhanced tissue graft survival in a method comprising
(a) administering to a mammal undergoing a tissue graft an anesthetic agent and an alpha adrenergic receptor agonist to the site of the tissue graft, wherein the anesthetic agent is administered in an amount effective to provide local anesthesia and the an alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels at the site and prolong the local anesthesia, (b) performing the tissue graft procedure, and then (c) administering an alpha adrenergic receptor antagonist to said site to reduce the prolongation and enhance the tissue graft survival.
In a preferred embodiment, the tissue graft is a hair graft. In another preferred embodiment, a low dose of alpha adrenergic receptor antagonist is administered to the site to avoid untoward side effects.
Such hair grafts include skin flaps containing a plurality of hair cells and single transplanted hair cell follicles. Typically, such hair grafts are obtained from a site on the animal that has actively growing hair. According to the present invention, an alpha adrenergic receptor antagonist is administered after a hair graft procedure to reverse the local anesthesia and reduce post-operative telogen effluvium (shedding of hair) and survival of the skin flap.
In another embodiment, hyaluronidase may be administered to the tissue graft site to increase survival of the graft. According to Pimentel, L. A. S. and Goldenburg, R. C. d. S, Revista da Soociedade Brasileira de Cirurgia Plastica 14 (1999), the local administration of hyaluronidase increases skin flap survival. According to the authors, hyaluronidase is an enzyme that reduces or prevents tissue injury presumably by causing the rapid diffusion of extravasated fluids to distant areas, thus allowing a better turnover of nutrients. The hyaluronidase is generally injected one or more times into the site of the hair graft. Similarly, the present invention can be used to improve survival of other engrafted tissues or bone in any graft surgical procedure where a local anesthetic and an alpha adrenergic receptor agonist is used minimize bleeding during the surgery and where subsequent rapid reperfusion of tissue is desired in order to increase graft survival.
In a further embodiment, an alpha adrenergic receptor antagonist is administered after a regional anesthetic block to reverse the block. Epidural anesthesia is commonly administered to provide a regional anesthetic block in a number of medical procedures including child birth, cesarean section, surgery to the pelvis and the like. Prolonged epidural anesthesia has many untoward side effects, including prolonged paralysis, inability to voluntarily urinate, and hypotension. Typically, the anesthesiologist injects into the epidural space an equal volume of saline in an effort to dilute the anesthetic and reduce the anesthesia.
The present invention solves the side effect problems by providing for on demand reversal of the anesthesia without the need for injecting large volumes of saline. In this embodiment, the invention relates to a method of providing a regional anesthetic block to a mammal, comprising:
(a) administering to a mammal in need thereof an anesthetic agent and an alpha adrenergic receptor agonist in the site to receive the anesthetic block, wherein the anesthetic agent is administered in an amount effective to provide local anesthesia and the alpha adrenergic receptor agonist is administered in an amount effective to constrict the blood vessels in the site and prolong the local anesthesia, and then (b) administering an alpha adrenergic receptor antagonist to the site to reduce the prolongation.
In a preferred embodiment, a low dose of the alpha adrenergic receptor antagonist is administered. In another preferred embodiment, the anesthetic block is epidural anesthesia and the site of the block is the epidural space. The invention has application to reversal of other blocks as well including brachial plexus and femoral blocks.
In another embodiment, hyaluronidase is administered together with the alpha adrenergic receptor antagonist to enhance the diffusion of the alpha adrenergic receptor antagonist within the site of the block, e.g. the epidural space, and speed reversal of the anesthesia.
The invention also relates to a kit comprising a carrier means such as a carton or box having in close confinement therein two or more container means such as carpules, vials, tubes, jars and the like. A first container means contains an anesthetic agent and optionally an alpha adrenergic receptor agonist and a second container means contains a low dose of an alpha adrenergic receptor antagonist. Alternatively, the alpha adrenergic receptor agonist may be present in a separate container means. A further container means may contain hyaluronidase. Alternatively, the hyaluronidase is in the same container means as the alpha adrenergic receptor antagonist. In a preferred embodiment, the anesthetic agent, alpha adrenergic receptor agonist, alpha adrenergic receptor antagonist and, optionally, the hyaluronidase are present in 1.8 mL carpules that fit into a standard dental local anesthetic syringe. Such carpules are available commercially from a variety of suppliers, e.g. Henry Schein, Port Washington, N.Y. In this embodiment, a carpule containing the local anesthetic and alpha adrenergic receptor agonists is placed into the syringe, and the mixture is injected. The carpule may then be removed and a second carpule inserted which contains the alpha adrenergic receptor antagonist and, optionally, the hyaluronidase.
The anesthetic agent, vasoconstrictor, alpha adrenergic receptor antagonist and, optionally, the hyaluronidase may be present in solution, preferably, a sterile solution, optionally containing salts and buffers, or as part of a gel or paste for topical administration. See U.S. Pat. No. 4,938,970 and Remington's Pharmaceutical Sciences, A. Osol (ed.), 16th Edition, Mack Publishing Co., Easton, Pa. (1980).
Mammals which may be treated according to the present invention include all mammals that may experience the beneficial effects of the present invention. Such mammals include without limitation humans and veterinary mammals such as cattle, pigs, sheep, horses, dogs, and cats. When applied to children and veterinary animals, the prompt reversal of anesthesia inhibits the child or animal from tearing open fresh sutures.
The following examples are illustrative, but not limiting, of the method and compositions of the present invention. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in clinical therapy and which are obvious to those skilled in the art are within the spirit and scope of the invention.
EXAMPLES
Study Rationale and Purpose
Local anesthesia is widely used by dentists to effect anesthesia during dental procedures. Local anesthetics often contain alpha-adrenergic receptor agonists to cause vasoconstriction thereby prolonging anesthesia. The vasoconstrictor is necessary because local anesthetics without vasoconstrictor are too short-acting for most dental procedures. On the other hand, in many instances the prolonged local anesthetic effect lasts much longer than required for many dental procedures. It would be desirable to have a drug that could be used at will to rapidly reverse local anesthesia after it is no longer needed. Lingering local anesthesia can be the cause of injuries due to biting of the tongue or lips. Lingering local anesthesia can also result in loss of productivity due to missed work hours. Lastly, lingering local anesthesia is an inconvenience and it is perceived as an annoyance by many patients. The purpose of the present study was to determine whether phentolamine-mesylate, an injectable alpha-adrenergic receptor agonist, which is FDA approved for the systemic treatment of hypertension in pheochromocytoma patients, rapidly reverses prolonged local anesthesia when injected locally at a very low concentration. The phentolamine-mesylate concentration chosen for the present study was so low that it would be expected to lack systemic side-effects such as severe episodes of hypotension that have been described with the high systemic drug doses which are approved by the FDA for the treatment of hypertension in pheochromocytoma patients.
Study Design
The present human subjects study was designed to determine whether injection of a physiological saline solution containing an extremely low concentration of phentolamine-mesylate is able to accelerate the reversal of the effects of a previously injected local anesthetic agent containing an alpha-adrenergic receptor agonist. An injection of the physiological saline vehicle (without phentolamine-mesylate) served as the control. In order to compare the effects of phentolamine-mesylate to the vehicle in the same patient, bilateral local anesthesia injections were made into the mouth of the same patient. This was followed by injection of the phentolamine-mesylate containing local anesthetic reversal agent (LARA) into one side of the oral cavity, and injection of the saline vehicle (control) solution into the opposite side of the oral cavity. The time to reversal of the local anesthetic effect on both sides was then recorded to determine whether there is a difference between the two sides.
Drugs
The local anesthetic used was 2% polocaine (mepivacaine hydrochloride) with levonordefrin (1:20,000=0.05 mg/ml) (levonordefrin injection, USP) (Astra USA, Inc., Westborough, Mass. 01581). Levonordefrin is a sympathomimetic amine with a pharmacological profile similar to that of epinephrine, but with a lower potency. The local anesthetic reversal agent (LARA) was prepared as follows: A standard vial containing 5 mg of lyophilized phentolamine-mesylate for injection, USP (Bedford Laboratories, Bedford, Ohio 44146) was reconstituted with 1 ml of physiological saline using a sterile, disposable 3 ml syringe and a sterile disposable hypodermic needle. After dissolution of the lyophilized powder, 0.5 ml of the phentolamine-mesylate solution was withdrawn and injected into a 50 ml vial of physiological saline for injection (USP) by means of a sterile disposable 3 ml syringe and a sterile disposable hypodermic needle. The resulting LARA thus consisted of 0.05 mg/ml phentolamine-mesylate in physiological saline.
Methods
Three healthy, male human subjects, age 34-50, volunteered to have local anesthetic injected in the mouth bilaterally under the lip in an easily repeatable location. The exact time of each injection was recorded. The position chosen was above (apical) the prominence of the root of the upper cuspid teeth. This is a common site selected to numb the cuspids, lateral incisors and upper lip. The volume of the local anesthetic injected was 1.7+0.1 ml on each side of the mouth. Twenty minutes after the local anesthetic was injected, each subject was re-injected with 1.6 ml of LARA on one side and 1.6 ml of physiological saline on the opposite side. A different size needle was used for the anesthetic and LARA or saline. A longer needle ({fraction (11/4)}″) was used for the local anesthetic resulting in more solution being deposited around the infra-orbital nerves. LARA or saline were injected with a shorter needle (½″) resulting in less LARA coming into contact with the anesthetic agent around the infra-orbital nerves. After all subjects received anesthetic agent followed by LARA or saline, the subjects were asked to test the intensity of numbness on both sides at the following sites in the mouth and face: teeth, nose, upper lip and gingiva. Numbness of the teeth was tested by biting or grinding. Lip numbness was tested with the touch of the finger or tongue, and nose numbness was tested with the touch of the finger. Gingiva numbness was tested with the blunt end of a wooden cotton swab.
Blinding
Two of the subjects (E and M) were blinded with respect to the side of the mouth where LARA or saline vehicle were injected, i.e. the subjects were not told by the PI which side received LARA and which side received saline vehicle. The third subject (H) was the PI of the study who injected himself. As a consequence, subject H was not blinded with respect to the side at which LARA or saline were injected.
Results
In all three subjects there was a dramatic acceleration of local anesthesia reversal on the side that had been injected with LARA compared to the side that had been injected with saline. No side-effects of any kind were noted in any of the three subjects. In general, feeling to the teeth returned first. Table 1 shows the times at which numbness disappeared and sensations re-appeared in the three subjects at the various sites on both sides of the mouth and face. In the early stages of recovery the subjects reported that it was somewhat difficult to determine which side of the lip was recovering first. In the later stages of recovery, however, the differences between the two sides of the lip were profound and dramatic. In the other parts of the mouth and face, lateral differences were reported to be pronounced even in the very early stages of recovery. The difficulty to sense lateral differences in the lips between the two sides early in the recovery process is thought to be due to the following fact: The labial branches of the infra-orbital nerve decussate at the midline, resulting in a crossover of innervation (and resulting sensation) at the midline of the upper lip.
TABLE 1
Subject E - LARA on right hand side (RHS), Vehicle on LHS
Recovery Time RHS
Recovery Time LHS
Site of anesthesia
(Minutes)
(Minutes)
Teeth 80% Recovered
21
85
Teeth Fully Recovered
28
101
Nose
30
143
Lip
41
83
Gingiva
46
141
Subject M - LARA on LHS, Vehicle on RHS
Recovery Time LHS
Recovery Time RHS
Site of anesthesia
(Minutes)
(Minutes)
Teeth
32
121
Nose
40
163
Gingiva
45
102
Lip
36
178
All Sensation
58
229
Subject H - LARA on RHS, Vehicle on LHS
Recovery Time RHS
Recovery Time LHS
Site of anesthesia
(Minutes)
(Minutes)
Teeth 80% Recovered
19
201
Teeth 100% Recovered
27
218
Gingiva
42
137
Lip
37
226
Nose
25
140
All Sensation
58
263
Conclusion
LARA had a profoundly faster effect on removing the numbness associated with local anesthesia than using physiological saline. The total amount of phentolamine-mesylate contained in the administered LARA solution was 0.08 mg (1.6 ml of a 0.05 mg/ml solution). This total dose of phentolamine-mesylate is approximately 62 times lower than the 5 mg dose approved by the FDA for systemic treatment of hypertension in pheochromocytoma patients (1 ml of a 5 mg/ml solution) and which can cause severe episodes of hypotension in normal patients. At the extremely low efficacious doses found to be effective in the present study, any systemic side effects, such as those that can occur with the FDA-approved high dose, are likely to be absent. Indeed, in the present study, no side-effects of any kind were noted during or after administration of 0.05 mg/ml phentolamine-mesylate.
Having now fully described this invention, it will be understood by those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions, formulations and other parameters without affecting the scope of the invention or any embodiment thereof. All patents, patent applications and publications cited herein are fully incorporated by reference herein in their entirety.
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Methods of reversing local anesthesia are disclosed. The methods comprise administering a local anesthetic and alpha adrenergic receptor agonist to induce local anesthesia followed by reversing anesthesia with a low dose of an alpha adrenergic receptor antagonist. Also disclosed are kits comprising a local anesthetic, an alpha adrenergic receptor agonist and a low dose of an alpha adrenergic receptor antagonist.
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TECHNICAL FIELD
The present invention relates to a battery-driven handtool having a handgrip which carries at its one end a motor casing and which includes an electrical switch connected to a supply line which extends between the motor housed in said casing and a power source by means of which motor is driven.
BACKGROUND ART
Battery-driven handtools, such as drilling machines or screw tightener, generally designated "cordless machines" are available commercially in a large number of varities. All of these machines, however, have one feature in common, namely that located somewhere on the machine is a current source in the form of a battery pack.
This battery pack is relatively heavy and has a relatively large volume. Known cordless machines suffer in various ways due to the presence of the battery pack, since the pack is either dimensioned or positioned so as to be accommodated predominantly within the handgrip. Consequently, the handgrip casing surrounding the battery pack becomes too large for a hand of average size. Another known variant is one in which a much smaller part of the battery pack is enclosed within the handgrip part, while the major part of the battery pack "hangs" beneath the handgrip. Although this enables the handgrip to be dimensioned as desired, the arrangement increases the total outer dimensions of the machine. This means, in turn, that the centre-of-gravity of the machine will be unsuitably positioned, among other things, and that it is at times difficult to use the machine in confined working spaces.
DISCLOSURE OF THE INVENTION
The aforesaid drawbacks are avoided completely or partially with the inventive battery-driven handtool, the current source of which is carried substantially in a holder located on the free end of the handgrip. The holder is asymmetrically mounted with respect to an axis passing through the free end of said handgrip, and can be adjusted to at least two mutually opposing positions.
Adjustment of the holder between these two, mutually opposite directions is effected advantageously by rotating or twisting the holder around said axis, said holder thus being rotatably mounted on the free end of the handgrip.
The advantages afforded with this arrangement are that when the working space is very confined, the outer dimensions of the machine can be minimized by choosing the smallest space-requiring battery position, and that when the working space so permits, a free choice can be made between the two alternative holder positions and therewith also the prevailing position of the centre of gravity of the machine.
DESCRIPTION OF PREFERRED EMBODIMENTS
The inventive battery-driven handtool will now be described in more detail with reference to exemplifying embodiments thereof illustrated in the accompanying drawings, in which
FIG. 1 illustrates a battery-driven handtool in the form of a pistol-like drilling machine, and shows the holder which houses the tool current source in a forwardly extended position;
FIG. 2 illustrates the same handtool as that shown in FIG. 1 but with the holder for the tool current source rotated through 180°, i.e. extending rearwardly;
FIG. 3 is a vertical section through a lower part of the handgrip and the current source holder, and illustrates a preferred form of the rotatable mounting which joins the holder to the handgrip; and
FIG. 4 is a section taken through the line IV--IV in FIG. 3 and indicates the position of the batteries in the holder, these batteries forming said electric current source.
FIGS. 1 and 2 illustrate a battery-driven handtool constructed in accordance with the present invention. The illustrated tool is a pistol-like drilling machine comprising a handgrip 1 which carries a motor casing 2 at one end thereof. This end of the handgrip also carries a switch 3.
Mounted on the lower, free end of the handgrip 1 is a holder 4 which is intended to house the electric current source required for driving the motor journalled in the motor casing 2. In accordance with the present invention, the holder 4 is journalled for asymmetric rotation around a pivot axis A. Thus, the holder 4 can be rotated or turned between a forwardly extending or protruding position, shown in FIG. 1, and a rearwardly extending or projecting position shown in FIG. 2.
By rotating the holder 4, it is possible to alter the shape of the tool, so as to enable the tool to be used when working in confined spaces, without changing the gripping surface of the handgrip 1, for instance. When the holder is located in its forwardly extending position, shown in FIG. 1, the outer dimensions of the tool are at a minimum and the centre-of-gravity TP of the tool lies forwardly of the switch 3. When the holder 4 is in its forwardly extending position, said holder can also be used as a foot or stand on which the tool can be supported when not in use.
When the holder is adjusted to its rearwardly extending position, shown in FIG. 2, the centre of gravity TP is moved into the tool handgrip 1. Thus, the person using the tool is able to shift the centre of gravity point TP as desired. The lower surface of the handgrip 1, against which the holder 4 abuts, will suitably form an angle α with a plane P extending parallel with the longitudinal axis L of the motor casing 2. As a result, there is obtained a free space for accommodating the wrist of the user, despite the fact that the holder 4 extends rearwardly. This angularly positioned surface also affords the advantage of further minimizing the tool dimensions when the holder 4 is switched to its forwardly extending position shown in FIG. 1.
FIG. 3 is a vertical section of the coupling or mounting between the lower part of the handgrip 1 and the holder 4. This Figure illustrates a preferred embodiment of the rotational coupling of the holder 4 to the free end of the handgrip 1.
According to the preferred embodiment of the holder 4 of the inventive tool, the holder is configured as a housing for accommodating a plurality of electric batteries B1-B8 which form said current source. That side 5 of the housing which faces towards the free end of the handgrip 1 has an opening provided with a flange 6. The flange 6 is intended to be received in a recess 7 in the free end of the handgrip 1. Both the opening in the housing side 5 and the recess 7 have a circular cross-section, and the flange 6 is pivotally mounted in the recess 7, as indicated by the balls 8, which are spring biased so as to snap into a peripheral groove around the surface of the flange 6.
The holder 4 is thus detachably mounted in the recess 7 of the handgrip 1, so as to enable the batteries B1-B8 to be recharged without needing to remove the batteries from the holder 4. When recharging the batteries B1-B8, there is used an electric contact plate 9 provided on the flange 6 and the one therewith exposed pole 10 of the upstanding battery B8. As will be seen from FIG. 3, the same electrical connections 9 and 10 are used for connecting the conductors 11 and 12 extending from the motor of the drilling machine. The conductor 11 is therewith connected to a first contact spring 13 which lies against the contact plate 9. The conductor 12 is connected to a second contact spring 14, which lies against the pole 10 of the battery B8 when the holder 4 is mounted in the recess 7.
The aforedescribed electrical contact arrangement 13, 9 and 14, 10 respectively enables the holder 4 to be rotated through 360° relative to the handgrip 1.
Naturally, the electrical contact arrangement can be simplified by permitting the holder and the handgrip to rotate through only 180°, and to provide stop means which will prevent rotation of the holder 4 beyond the forwardly extending and rearwardly extending limit positions.
In the case of a modified embodiment of the inventive tool, the holder 4 is not rotatably mounted on the handgrip 1, but is instead capable of being fitted in two distinct, alternative positions. In this case, the holder 4 is either fitted in a forwardly extending position, as shown in FIG. 1, or, alternatively, in a rearwardly extending position shown in FIG. 2. This avoids the provision of complicated movable journal means in the handgrip and on the flange 6 fitted therein.
FIG. 4 is a top view of the preferred embodiment of the holder 4, and is a sectional view taken on the line IV--IV in FIG. 3. The Figure also indicates the positioning of the batteries B1-B8.
Although the battery-driven handtool has been described in the aforegoing with reference to the drawings and with reference to a particular configuration of a drilling machine, it will be understood by one skilled in this art that the fundamental principle construction, as defined in the following Claims, can be modified in many ways without departing from the inventive concept. For instance, the positioning of the batteries may be different to that illustrated and the batteries need not, of course, be connected in series as illustrated in FIG. 3. Neither is the number of batteries used of decisive significance, and neither is the fact that the batteries are shown upstanding in the holder. The batteries may equally as well be held in horizontal positions, in two or more layers in the holder, which can also have a different layout to that illustrated.
Thus, the battery-driven tool shall not be considered to be limited to the described and illustrated embodiments, since other, different conceivable solutions are possible within the scope of the following Claims.
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A battery-driven handtool is configured with a holder (4) for housing the current source, this housing being detachably connected to the handgrip (1) of the tool. The holder is journalled for asymmetric rotation (around A) on the free end of the handgrip, so as to enable the outer dimensions of the tool to be minimized, by causing the holder to take at least two mutually opposing positions when the working space is confined, thereby also enabling the center of gravity point (TP) of the tool to be changed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of my U.S. patent application Ser. No. 10/424,671, filed 28 Apr. 2003 and published as US2004/0022645 on 5 Feb. 2004. Priority of my U.S. Provisional Patent Application No. 60/375,889, filed 26 Apr. 2002, incorporated herein by reference, is hereby claimed. Incorporated herein by reference are the two above-referenced patent applications, my international patent application no. PCT/US2003/12948, filed 28 Apr. 2003, and published as international publication no. WO 03/091571, and all publications mentioned herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to compressors, pumps, and engines. More particularly, the present invention relates to a pumping apparatus that includes two housing or rotor sections that engage a spherical bearing that enables each housing section to rotate together but about different axes of rotation. These axes intersect to form an obtuse angle. Valved pistons on the housing sections pump fluid as the housing sections are rotated.
[0006] 2. General Background of the Invention
[0007] The three predominate forms of pumping, driving and compressing that are available on the market at the time of this document are reciprocating, mechanical screw and rotary and centrifugal.
[0008] The following patent documents are incorporated herein by reference:
[0009] U.S. Pat. Nos. 3,945,766; 4,277,228; 4,858,480; 5,249,512; 5,647,729; 6,352,418; 6,368,072; JP 02305381A and US2001/0014288.
[0010] U.S. Published Patent Application No. US2001/0014288 discloses a pump with a back and forth piston motion (see FIG. 12 ).
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention provides a unique pump apparatus. However, the mechanism of the present invention can also be configured to be a compressor or engine. As used herein, the term pump should be broadly construed to include any piston machine including but not limited to a pump, a compressor or engine.
[0012] The apparatus includes a first housing or rotor section having a concave portion. A second housing section is provided that also has a concave portion.
[0013] A spherically shaped bearing member forms an interface between the first and second housing sections so that the concave portion of each of the housing sections fits and conforms to the outer surface of the spherically shaped bearing member. The outer surface of the spherical bearing member and the inner surface of the concave portions are preferably identically curved.
[0014] A first shaft is provided for rotating the first housing section about a first axis. A second shaft can be provided for rotating with the second housing section about a second axis that forms an obtuse angle with the first axis.
[0015] A plurality of valved pistons are positioned circumferentially about the spherically bearing member, each piston having an upper portion on the first housing section and a second portion on the second housing section.
[0016] A means is provided for rotating one of the shafts to initiate the pumping apparatus. The rotating means can be, for example, a motor, engine or the like.
[0017] The pistons are interconnected so that they interconnect the first and second housing sections. When one housing section is rotated, the other housing section rotates with it. As a shaft (e.g., powered or driven) is rotated, its housing sections rotate about different axes that form an obtuse angle. Because of this obtuse angle seen in FIGS. 5-10 , the periphery of one housing section approaches and then spaces away from the periphery of the other housing section in continuous fashion along a circumferential path.
[0018] A fluid flow path transmits fluid though the housing sections using the pistons. Each piston reciprocates to pump fluid under pressure as the housing sections rotate.
[0019] The first and second housing sections can each have a generally rounded periphery. At least one of the concave sections of the housing sections, and preferably both of the concave sections of the housing sections, closely conform to and fit the outside surface of the spherically shaped bearing member. The pistons can be equally spaced apart, positioned radially of and circumferentially around the spherically shaped bearing member.
[0020] The pistons preferably each include interlocking portions of the first and second housing sections.
[0021] Each piston can include a projecting part of one of the housing sections and a socket part of the other of the housing sections. The projecting and socket parts interlock. Each piston is valved (e.g., two check valves) so that as each piston expands and contracts, fluid is pumped through the piston in a desired direction.
[0022] The machine (e.g., pump, compressor, engine) of the present invention was invented to replace the three predominate forms of pumping, driving and compressing that are available on the market at the time of this document.
[0023] The machine of the present invention combines the good attributes of each and discards the inadequacies. Inherently, a reciprocating device is very flexible in its variations of flow stream acceptability while having many moving parts subject to wear and damage.
[0024] This machine of the present invention has the ability to fit a wide variety of flow situations by varying speed and loading and unloading individual piston/receiver pairs. This flexibility is accomplished with very few moving parts subject to wear and damage.
[0025] Mechanical screw rotary devices have few moving parts yet they cannot accept high speeds due to the geometry and shear mass of the rotating compression screws. They also require extensive sealing be it mechanical or oil flood to entrap the compression fluids. Screw type compressors fit the function of compressing fluids from a set pressure to a higher pressure at a set flow rate and can do little with varying flow conditions.
[0026] The machine of the present invention institutes the small number of wear parts inherent to the screw while surpassing its ability to be flexible. Centrifugal devices have the ability to compress large quantities of fluids from low pressure to high pressure yet they accept little variations in flow rate and pressure differential. So much is the effect of variations, in a driver configuration (turbine) intricate surge control systems must be designed to protect the units against damage. In addition, very little solid particular or larger matter introduced to the flow stream will produce catastrophic and costly damage. Centrifugal devices are not positive displacement and are greatly affected by stream contents and characteristics.
[0027] The machine of the present invention has the ability to compress large quantities of fluids with increased speeds or staging of the unit while not being affected adversely by the content nor characteristics of the flow stream being positive displacement and not dependant on the holding of tight engaging dimensions.
[0028] Using, for example, the stream requirements of typical offshore facilities and for a summary, three types of compression are used. For vapor (low-pressure) compression, rotary oil flood screws are used to compress fluid up to low-pressure well pressures. This stream is combined with low-pressure wells and introduced to a reciprocating compressor to bring the stream first to the pressure of intermediate fluid then to deliver the fluid to a turbine driven centrifugal compressor for boosting to pipeline pressure at large flow rates.
[0029] This machine of the present invention replaces all three units at the facility in a multi-stage configuration. The multi-stage unit would be setup in stage series and parallel configurations per stage if required as follows: Stage 1 is vapor compression, stage 2 is low-pressure fluid, stage 3 is intermediate pressure fluid, stage four high-pressure boost.
[0030] All compression is accommodated in one multi-stage unit with less vulnerability to wear and failure and with the flexibility required. To enhance the appeal of the machine of the present invention, an engine can be used to integrally drive a multi-stage unit for an extreme savings of labor, repair, deck space platform weight and operator interface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0032] FIG. 1A-1B are exploded perspective views the preferred embodiment of the apparatus of the present invention and wherein the figures meet at match lines A-A;
[0033] FIG. 2 is a exploded side, sectional view of the preferred embodiment of the apparatus of the present invention;
[0034] FIGS. 3A-3B are fragmentary sectional views of the preferred embodiment of the apparatus of the present invention showing maximum opening in FIG. 2A and minimum opening if 3 B;
[0035] FIGS. 4A and 4B are schematic plan views showing one of the housing sections, with a single circle of pistons in FIG. 3A and a double circle of pistons in 3 B;
[0036] FIG. 5 is a side sectional view of the preferred embodiment of the apparatus of the present invention;
[0037] FIG. 6 is a side sectional elevation view of the preferred embodiment of the apparatus of the present invention;
[0038] FIG. 7 is a side sectional view of the preferred embodiment of the apparatus of the present invention showing a single stage unit;
[0039] FIG. 8 is a side sectional view of the preferred embodiment of the apparatus of the present invention showing a multi-stage unit;
[0040] FIG. 9 is a side sectional view of the preferred embodiment of the apparatus of the present invention illustrating a free rotor engine;
[0041] FIG. 10 is a side sectional view of the preferred embodiment of the apparatus of the present invention showing a dual rotor engine;
[0042] FIG. 11 is a side sectional exploded view of an alternate embodiment of the preferred embodiment of the apparatus of the present invention;
[0043] FIG. 12 is a top view of an alternate valve construction for use with the present invention;
[0044] FIG. 13 is a side view of an alternate valve construction for use with the present invention;
[0045] FIG. 14 is a side exploded view thereof for a piston valve;
[0046] FIG. 15 is a side exploded view thereof for a receiver valve;
[0047] FIG. 16 is a top view of another, alternate pressure booster design that shows a suction inlet scoop design (the scoop acts as a pressure booster); and
[0048] FIG. 17 is a side view thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0049] In FIGS. 1A, 1B and 2 - 6 , the preferred embodiment of the apparatus of the present invention is designated generally by the numeral 5 . Pump apparatus 5 includes an upper housing or rotor section 10 and a lower housing or rotor section 16 . Each of the housing sections 10 , 16 rotate together as a unit when one of the housing sections 10 or 16 is rotated such as with a powered or driven shaft (e.g., shaft 90 ). Rotation can be clockwise or counterclockwise.
[0050] The apparatus 5 includes a plurality of pistons 11 . Each piston 11 carries a suction valve assembly 40 to seal the interface between projection 18 and socket 19 of each piston 11 . Valve 40 orientation determines which side (i.e. section 10 or 16 ) is suction and which is discharge. Either section 10 or 16 can be a driver or be driven. The apparatus 5 can be used with or without spherical ball bearing 20 , though use of bearing 20 is preferred.
[0051] A seal 12 on the outer surface of projection 18 part of piston 11 is provided. Seal 12 can be on the piston 11 or on the socket 19 of receiver 31 . Socket 19 of piston 11 is provided on the second housing section 16 as shown in FIGS. 1A, 1B and 2 - 6 .
[0052] Housing section 10 has inlet fluid chamber 61 that is receptive of fluid to be pumped or compressed. Housing section 16 has discharge passageway 64 through which fluid being pumped is discharged. The suction valve assembly 40 is positioned in inlet fluid chamber 61 . A discharge valve assembly 50 is positioned in discharge passageway 64 .
[0053] Ball or spherical bearing 20 forms an interface bearing that contacts both of the housing sections 10 , 16 at respective dished or concaved surfaces 21 , 22 . In FIG. 6 , a gearing system 13 (e.g., toothed racks) can be optionally used to mechanically interface and transfer load between the housing sections 10 , 16 .
[0054] In FIG. 7 , a single stage unit is disclosed wherein the upper and lower housing section 10 , 16 are mounted within a block 6 that is defined by block sections 101 , 102 , 103 , outer surfaces 30 engaged by sections 101 , 102 , 103 . Seals 14 can be provided in between each housing section 10 , 16 and block 6 . In FIG. 11 , a suction pressure booster 15 can be added to housing section 10 . Torque enhancer 34 can be added to section 16 .
[0055] In FIG. 11 , part 15 is a pressure booster that can be finned either centrifugally or axially to boost the stream delivered to the suction valves. This booster 15 takes advantage of the fact that the rotor 10 is revolving in water and mechanically increases delivery to the compression chamber.
[0056] Part 34 has the opposite effect on the stream. It operates as a torque enhancer. As fluid leaves chamber 64 , it will impinge on part 34 slightly reducing the stream pressure while giving the apparatus 5 added torque boost though fluid impact on part 34 .
[0057] FIG. 8 shows a multi-stage unit 17 that can be comprised of a plurality of blocks 6 each having an apparatus 5 . Each apparatus 5 has its own flow inlet and flow outlet as shown, designated generally by the numerals 111 - 116 in FIG. 8 .
[0058] The obtuse angle that is formed between an axis of rotation for the sections 10 , 16 is shown in FIG. 8 as 180° plus angle 72 . The apparatus 17 of FIG. 8 thus shows a multi-stage apparatus that could have utility, for example, in the pumping of gas when the apparatus 17 is to be used as a compressor. Each socket 19 defines a receiver 31 into which projecting portion 18 extends.
[0059] An optional gearing system 13 , 32 can help transfer load between the sections 10 , 16 when they are rotated together using shafts 23 , 24 .
[0060] Two meshing gears 13 , 32 can be mounted on the housing sections 10 and 16 respectively. The clearances between the gear teeth is less than the clearance between piston 11 and receiver 13 . Therefore, the transfer of torque from part 10 to part 16 (i.e. driver to driven) is carried by the gears 13 , 32 and not the seal rings 12 . If there is no gear 13 , 32 provided, part 10 transfers torque to part 16 and vice versa using seal 12 pushing on socket 19 .
[0061] FIG. 4A is a schematic plan view showing one of the housing sections, with a single circle of pistons 11 in FIG. 4A and a double circle of pistons 11 in 4 B;
[0062] Each rotor section or housing section 10 , 16 can have angle cuts 70 along the face, a dished cut out or concave surface 21 mating face for the spherical ball bearing 20 . Conversely, depicted is the receiver rotor 16 including receivers 31 , outlet chamber ports 63 , discharge valve assemblies 50 depicted but not limited to ball/spring type and rotor outlet discharge passageway 64 .
[0063] Fluid enters suction port 61 either boosted by part 15 or not, at a pressure assuming FIG. 3B minimum position as the piston 11 pulls away from the receiver 30 a lower pressure is experienced in chamber 60 . The pressure differential between the suction passage 61 and compression chamber 60 opens valve 40 to allow fluid flow into chamber 60 . During this operation, discharge valve 50 remains closed due to higher discharge line pressure in discharge chamber 64 compared to compression chamber 60 . At FIG. 4A , maximum position, both valves 40 , 50 are closed. During the compression stroke going from position 3 A (maximum) to position 3 B (minimum) pressure builds up in chamber 60 . This higher pressure closes valve 40 as the pressure in the chamber 60 is higher than the suction line pressure 61 .
[0064] When the pressure in chamber 60 becomes greater than the discharge pressure in port 64 plus the valve seating pressure, the discharge valve 50 opens and releases chamber 60 pressure into port 64 and into the discharge line. The drawings show a ball/spring combination which valve seating pressure is a function of ball area in contact with the stream and a spring constant.
[0065] An alternative valve design is shown in FIGS. 12-17 , designated as valve 45 . Valve 45 replaces the spring 42 or 52 with a shim disk 47 for which the spring constant is replaced by the beam flex of the shim disk 47 . This shim disk 46 shows a smaller profile radially to the rotor 10 and 16 rotation reducing the centrifugal force effects on the mechanical operation of the valve allowing for higher speed operation. Valve 40 can be comprised of a ball 41 , spring 42 and sleeve 43 having valve seat 44 . Similarly, valve 50 can be comprised of ball 51 , spring 52 and sleeve 53 having seat 54 . For the alternate valve 45 , a housing (e.g. steel) 46 has multiple radially and peripherally placed flow openings 48 covered with shim 47 (e.g. rubber or polymeric or metal). A central fastener 49 holds shim 47 to body 46 . Flow through body 46 and its openings 48 causes shim 47 to bend and enable valve 45 to open.
[0066] Another pressure booster 54 is seen in FIGS. 16-17 that uses housing 55 that is U-shaped. A shim 56 (e.g. metal) covers flow opening 57 . Fasteners 58 secure shim 56 to housing 55 . Flow through housing 55 and its opening 57 causes shim 56 to bend and enables pressure booster 54 to open.
[0067] The face of the housing section 10 is cut at an angle 71 and includes dished cut out or concave surface 22 mating face for acceptance of orbiting ball or sphere 20 . The ball 20 is not limited to being a separate item but also may be an integral part of either the piston rotor 10 or the receiver rotor 16 , 30 .
[0068] FIG. 3A is a diagram of maximum opening of a piston 11 , and maximum volume, minimum pressure of the compression chambers 60 at the zero degree of rotation point between the piston rotor 10 and the receiver rotor 16 in relation to valve inlet 62 of piton 11 and outlet 64 . FIG. 3B is a diagram that shows minimum opening and minimum volume, maximum pressure of the compression chambers 60 at the 180 degree of rotation point between the piston rotor 10 and the receiver rotor 16 in relation to valve inlet 62 and outlet 64 .
[0069] FIG. 4A illustrates an exemplary layout of piston/receiver pairs 11 / 31 on the piston rotor 10 and receiver rotor 30 mating circle 82 while centering on the orbiting rider ball 20 .
[0070] FIG. 4B illustrates an exemplary layout of piston/receiver pairs 11 / 31 on the piston rotor 10 and receiver rotor 30 dual mating circles 82 / 83 while centering on the orbiting rider ball 20 .
[0071] FIG. 5 illustrates the engagement geometry of the piston rotor 10 , the receiver rotor 30 on the orbiting rider ball 20 with integral porting and valving described in FIG. 2 . Linear offsets from the center of rotation (center of orbiting rider ball 20 ) 80 / 81 are depicted along with the piston rotor 10 rotation angular offset 72 . Also, circumferential piston/receiver circular path 84 is shown.
[0072] FIG. 6 illustrates machine 5 including all aspects of subsequent figures combined with rotational shafts (clockwise or counter clockwise) 90 / 92 and a system of bearings to contain the rotation both in radial and axial directions. These bearings can be preferably installed to a fixed case or housing. Also depicted are a system of seals 14 / 33 to separate suction and discharge and provide an internal chamber that can be liquid filled for lubricating (if necessary) or cooling (predicted). In addition, a torque transmitting gearing system 13 / 32 is provided to allow driving through the machine 5 without relying on the piston/receiver 11 / 31 and seal 12 surfaces to provide that function. In certain designs the engaging piston/receiver/seal 11 / 31 / 12 surfaces may be able to transfer the torque. Therefore, the apparatus of the present invention does not exclude piston/receiver/seal 11 / 31 / 12 as an option for torque transmission.
[0073] FIG. 7 is an illustrative example of a single stage unit 6 incorporating the machine 5 in a fixed split housing 101 / 102 providing a fluid inlet connection 107 , a suction collection chamber 105 open to all piston rotor inlet chambers 61 . A fluid outlet discharge chamber 104 is provided, open to all receiver discharge ports 64 along with a housing outlet connection 106 . Additionally, an end cap 103 is depicted to provide and additional bearing to confine the driven rotor that may or may not be necessary in all configurations.
[0074] FIG. 8 is an illustrative example of a multi-stage unit 17 which in effect is an alignment of single stage units 6 provided with an end cap. Although the multi-stage unit is shown as a having an external transfer of fluid for cooling and side streaming, all stages may be incorporated in a single housing. Fluid would pass from stage to stage internally and connection inter-stage for cooling and side streaming would be provided as an integral part of the single case.
[0075] FIG. 9 is an illustrative example of a free rotor engine 130 is depicted incorporating the machine 5 and allowing the receiver rotor to rotate on a case mounted bearing assembly 94 mounted as part of the split housing 132 . Fuel would be introduced to the inlet chamber 140 and open to each of the piston rotor 10 inlet suction passageways 61 . Around the 180-degree rotation position a sparking device 150 , connected to each combustion chamber 60 , would institute a spark in a combustion chamber. The release of combustion by-products would be via each piston/receiver pair 11 / 31 discharge valve assembly 50 through the outlet (exhaust) port 141 . The housing depicted is not the limit of this document for the housing of the machine 5 .
[0076] FIG. 10 is an illustrative example of a dual shaft rotating engine 135 that incorporates the machine 5 modified to include a sparking device for each receiver chamber 60 . As rotating will not provide the ability for permanent connection of the sparking devices 150 a points type system 152 being wired through an access connection 151 is illustrated. The housing depicted is not the limit of this document for the housing of the machine 5 .
[0077] FIG. 11 is an illustrative example of a suction pressure booster 15 and a discharge torque-enhancing device 34 added to the components described in FIG. 2 . These two items 15 / 34 serve as examples for suction pressure increase and discharge torque accumulation but do not limit the machine 5 to just these two examples.
[0078] The machine 5 of the present invention are positive displacement devices used to compress fluids (gas or liquid) or work as an engine by engaging piston 11 and receiver 31 chambers 60 that exist on two opposing rotors 10 and 30 . The compression occurs due to the inversion angle of the piston rotor 10 face in reference to the receiver rotor 30 face created by the engagement angle 72 or angular offset of the opposing shafts 90 / 92 (see FIG. 6 ). It is irrelevant which shaft 90 / 92 receives the displacement angle 72 . Side to side tilting of the piston 11 and receiver 31 sealing surfaces in relation to each other is handled by coordinating two sets of dimensions. First the angle cuts 70 / 71 in the piston 10 and receiver 30 rotors, then by the offsets 80 / 81 (see FIG. 5 ) from the center of the orbiting riding ball 20 . When the machine 5 is assembled, the two opposing rotors 10 / 30 are aligned on the riding ball 20 on opposing rotor cutouts 21 / 22 ( FIGS. 2 and 5 ). Compression occurs on a circular path 84 ( FIG. 5 ) radiated out from the center of rotation along the circumference of the circle 84 . Each chamber 60 is isolated from the environment via the use of sealing rings 12 that seal the surfaces between the pistons 11 and receivers 31 . The introduction of fluid (gas or liquid) is handled by a system of springs and balls that rotate with the rotor. For use as a pump or compressor 6 , each piston/receiver 11 / 31 combination has an adjoining suction spring/ball assembly 40 located in the piston rotor 10 . Conversely, for the release of fluid (gas or liquid) each piston/receiver pair 11 / 31 has an adjoining discharge spring/ball assembly 50 located in the receiver rotor 30 . The piston/receiver pairs 11 / 30 are located along a circular path radiated out 82 or 83 (see FIG. 4B ) as viewed from the center of the rotating shafts looking down the shaft toward the rotors 10 / 30 . Each device may have either one 82 or multiple 83 compression circles on the same piston/receiver rotor pairs 10 / 30 . For multi-stage operations 17 , one device may be aligned to work in parallel or series service with adjoining devices of the same make-up.
[0079] Fluids (gas or liquid) are introduced to the single stage unit 6 ( FIG. 7 ) through suction inlet 107 into the suction passage 105 . The fluid then enters rotor suction chamber 61 . Differential pressure in the compression chamber 60 and the rotor suction chamber 61 causes suction spring/ball assembly 40 to open allowing fluid into compression chamber 60 via suction rotor chamber inlet 62 . As the rotors rotate they cause the volume in the compression chamber 60 to decrease, thereby increasing the pressure. When the pressure in the compression chamber reaches a point higher than that of the discharge passage 104 , this differential pressure opens the spring/ball assembly 50 in the receiver rotor 30 . Fluid will then flow through rotor the compression chamber outlet 63 , over the spring/ball assembly 50 out of the rotor discharge passage 64 . This compressed fluid collects in the case discharge chamber 104 and exits the machine 6 through the unit discharge outlet 106 .
[0080] For multi-stage parallel or series service the flow path described above through the machine 5 from the suction rotor 10 inlet port 61 to the discharge rotor 30 outlet port 64 will remain consistent in each fluid compression path description to follow. For series stream compression, fluids (gas or liquid) are introduced to the multi-stage unit 17 through suction inlet 112 of the single stage unit 6 and through the machine 5 as described above. The fluid is collected in the case discharge chamber 111 and exits the single stage unit 6 . This fluid may be taken off for inter-stage cooling and the stream may be increased or decreased by side stream gas ready for entry into the next single stage unit 6 to the second stage inlet chamber 114 . The fluid is compressed though the second in-line machine 5 and passes through discharge outlet chamber 113 where again it may be cooled or effect a side stream as noted above. The fluid enters the next stage unit 6 through suction inlet chamber 116 . The fluid is again compressed to a higher pressure through the machine 5 located in this single stage unit 6 and delivered to discharge passage 115 ready for delivery to another single stage compression unit 6 or for final delivery for service. For purely parallel service connection, two or more single stage units 6 may be connected in parallel with common suction pressure delivered to the inlet suction chambers 112 / 114 / 116 . The fluid is compressed through each of the units and discharged through each single stage unit 6 , discharge outlet chamber 111 / 113 / 115 . For a mix of parallel and series service fluid may enter the first two single stage units 6 though the suction inlet chambers 112 / 114 and discharge through their discharge outlet chambers 111 / 113 . This stream may be cooled or a side stream may be effected readying the fluid for deliver to the suction inlet chamber of the next single stage unit 6 at suction inlet port 116 . The fluid is then compressed for final delivery exiting from the single stage unit 6 through discharge outlet chamber 115 . These are but a few examples of how the multi-stage unit 17 may be setup. These examples are not meant to restrict the machine 5 to any of the fore mentioned examples. Any combinations of connection either internal or external are acceptable. Any size rotor pairs 10 / 30 is acceptable and shall be sized for the flow characteristics of each compression stream. Any combination of compression rings 82 / 83 / 84 is acceptable and covered by this document. Any shape and geometry of rotor pairs 10 / 30 and piston/receivers 11 / 31 are acceptable as long as they maintain the sealing of the compression chamber 60 . Any configuration of inlet and outlet rotor passageways 61 / 62 / 63 / 64 and inlet and outlet valve assemblies 40 / 50 is acceptable.
[0081] This machine 5 , being a positive displacement device, will inherently have the ability to institute flow control via speed control with low and high-speed applications included. In addition, setup flow control can be instituted via insertion or removal of suction spring/ball value assemblies 40 / 50 to activate or deactivate individual piston/receiver pairs 11 / 31 , and is included. Any geometry for mounting the machine 5 into a case 6 and sizes of inlet and outlet chambers, passageways and connections are included.
[0082] For use as an engine 130 or 135 , each rotor may rotate as dual drive 135 or single shaft drive 130 . In the case dual drive 135 , each piston cylinder pair 11 / 31 may have an adjoining suction (intake) 40 and discharge (exhaust) 50 spring/ball combination for the introduction of fuel and the release of combustion gases. In addition, each piston/receiver 11 / 31 pair will also have an adjoining device to spark the combustion 150 be it spark plug, element, etc., and a system to deliver the spark 151 transferred external to the rotors 10 / 30 . In the case of single shaft drive 130 (case mounted bearing 94 ) this may be either the piston 10 or the receiver 30 rotor. The transfer of fuel to each chamber may be accomplished via a spring/ball combination 40 adjoined to each of the rotating piston/receiver 11 / 31 pairs. Each combustion chamber 60 will have an accompanying spring/ball assembly 50 in the case-rotating rotor to handle the release of combustion gases (exhaust) 141 . Sparking of each combustion chamber may be handled by the sparking device 150 attached to each combustion chamber 60 and fed through the spark generating case port 151 .
[0083] Torque requirements for use as an engine 130 / 135 may be effected and varied by the sequencing of spark delivered to the sparking device 150 . For example, at low torque requirement periods a combustion-instituting spark may only be delivered to a set number of alternating piston/receiver 11 / 31 pairs. As the torque requirements increase more and more chambers 60 will be ignited. As stated above for the compression unit 6 , the engine is not limited to the few configurations noted for engines 130 / 135 , but includes all mounting, sizes and geometry required to use the machine 5 for engine, torque development applications. Variable aspects may include, but not be limited to, bearings 91 / 93 / 94 , shafts 90 / 92 , inlet and outlet valves 40 / 50 , piston receiver pairs 11 / 31 , rotor pairs 10 / 30 , torque transfer gears 13 / 32 , seals 12 , sparking devices 150 / 151 . They also include case designs 131 / 132 / 133 or any other factor that is required to place the machine 5 in service as an engine, pump or compressor.
[0084] Additions to the device may include the attachment of a turbine type device 15 to the piston rotor 10 to institute an increase in pressure delivered to the suction spring/ball 40 inlet ports 61 . In a similar mounting arrangement, a torque converting or torque-enhancing device 34 may be mounted to the discharge or receiver rotor 30 . In driving, or force transmission through the rotors 10 / 30 from shaft 90 to shaft 92 , a gear system 13 / 32 may be incorporated as part of the rotors 10 / 30 to transfer the torque from shaft 90 to shaft 92 without transferring the force to the piston/receiver assemblies 11 / 30 nor to the seals 12 therein.
[0085] One of ordinary skill in this art will be able to determine appropriate materials for the various parts of the present invention.
[0086] All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
PARTS LIST
[0087] Parts No. Description
5 pump apparatus 6 block 10 upper housing section 11 piston 12 seal 13 gearing system 14 seal 15 suction pressure booster 16 lower housing section 17 multi-stage unit 18 projection 19 socket 20 spherical bearing 21 concave surface 22 concave surface 23 shaft 24 shaft 25 surface 26 surface 27 surface 28 surface 30 outer surface 31 receivers 32 gearing system 33 seal 34 discharge torque device 40 suction valve assembly 41 ball 42 spring 43 sleeve 44 seat 45 valve 46 housing 47 shim 48 opening 49 fastener 50 discharge valve assembly 51 ball 52 spring 53 sleeve 54 pressure booster 55 housing 56 shim 57 opening 58 fastener 60 compression chamber 61 inlet port 62 inlet 63 outlet chamber port 64 discharge passageway 70 angle 71 angle 72 angle 80 offset 81 offset 82 mating circle 84 mating circle 84 piston receiver circular path 101 block section 102 block section 103 block section 104 outlet chamber 105 suction chamber 106 housing outlet connection 107 fluid inlet connection 130 free rotor engine 132 split housing 135 dual shaft rotating engine 140 inlet chamber 141 exhaust port 150 sparking device 151 access connection 152 points type system
[0161] The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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A rotary piston machine includes a first spheroidal element including pistons and/or cylinders and a second spheroidal element including pistons and/or cylinders, wherein the first element can move relative to the second element. The machine can be used as part of a pump, compressor, or engine.
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This is a continuation of application Ser. No. 450,137 filed Mar. 11, 1974 now abandoned.
CROSS-REFERENCES TO RELATED APPLICATIONS
Ser. No. 450,139, U.S. Pat. No. 3,921,340, "Magnetic Head Surface Formation," by L. A. Johnson, N. L. Robinson, R. H. Strang and G. G. Vair, and Ser. No. 450,138, U.S. Pat. No. 3,955,213, "Magnetic Head Assembly," by R. D. Brower and N. L. Robinson filed on even date herewith, claim different aspects of the invention described herein.
The invention herein is an improvement over the apparatus and method described in Ser. No. 296,688, U.S. Pat. No. 3,821,815, "Apparatus for Batch-Fabricating Magnetic Film Heads and Method Therefor," by Abbott et al., filed Oct. 11, 1972, and commonly assigned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus and method for controlling the manufacture of magnetic heads.
2. Description of the Prior Art
In the cross-referenced Abbott et al. application, there are discussed the benefits made possible by thin film batch-fabricated magnetic heads. Also discussed are the problems of achieving the small dimensions and tolerances of such heads in a practical manufacturing environment. The solution is described as connecting groups of single-turn head elements deposited on a substrate together with conductive bridges. Electrical conduction through the bridges is monitored during fast rough grinding to the throat height dimension and, after the bridges break, the underlying element conductors are monitored. Grinding continues until the monitored value indicates that the final dimension has been reached. In one embodiment, the head oscillates during grinding. Additional advances have occurred in the art since the invention in the cross-referenced application was made. For example, new head surface contours cannot be obtained by oscillating the head during grinding. Also, new applications for single-track heads make techniques utilizing bridges spanning two or more elements impractical. It has become necessary to monitor electric current through a single-track magnetic head while the head is continuously rotating about an axis passing through the surface being formed.
Single-track, thin film, batch-fabricated magnetic heads are known. Bajorek et al. in an article in the Oct., 1973, IBM TECHNICAL DISCLOSURE BULLETIN at page 1372, describe a single-turn magnetoresistive recording head incorporating copper or gold conductors. Landler, in an article in the May, 1969, IBM TECHNICAL DISCLOSURE BULLETIN, pages 1792-1793, suggests monitoring the resistance of an extra conductor, surrounding a single-turn head, during lapping until current conduction is interrupted or becomes discontinuous. Landler appears to require four external leads.
A rotatable fixture for a multitrack magnetic head is described in U.S. Pat. No. 3,681,682 (C. M. Cox and R. B. Fisher, filed Dec. 21, 1970, issued Aug. 1, 1972, and assigned to International Business Machines Corporation). This fixture connects each track's winding, in turn, to testing equipment including impedance measuring circuits. A continuously rotating two-terminal carbon resistor is monitored by a Wheatstone bridge in U.S. Pat. No. 3,105,288 (D. E. Johnson and J. L. Owens, filed Feb. 27, 1959, issued Oct. 1, 1963, and assigned to Western Electric Company, Incorporated). Each resistor terminal is connected to the bridge through a single slip ring brush combination. A Kelvin bridge (Dawes, Electrical Engineering, pages 169-170, McGraw-Hill, 1952) provides vastly greater accuracy than a Wheatstone bridge, but requires four connections for a two-terminal, unknown resistance. Slip ring assemblies having more than one brush per ring are commercially available.
Thus, there is no suggestion in the prior art of a unified solution to the problem of monitoring, during surface formation, current through a head while it is in continuous rotation about an axis through the surface being formed.
SUMMARY OF THE INVENTION
This problem is solved by operating a stationary Kelvin bridge to monitor the resistance of a continuously rotating multi-lead head once for every predetermined number of turns while the head is in contact with a surface forming agent. The head turns on an axis which passes through the surface being formed and an external signal initiates relative motion, along this axis, between the head and the forming agent. When a predetermined resistance is detected, the axial motion is terminated and, ultimately, reversed. In one embodiment, a counter generates a count signal upon the occurrence of a predetermined number of head rotations and each count signal causes a resistance reading.
The foregoing objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates the tool, head and detection circuit used in the invention.
FIGS. 2A-2C are logic diagrams illustrating controls for operating the invention.
FIG. 3A includes a cross-sectional view of a tool used in the invention.
FIG. 3B is a cross-section through plane 3B--3B in FIG. 3A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
General Description
Referring first to FIG. 1, the invention will first be described schematically to explain the underlying principles. A head 10, shown split into two sections layers and 12, includes layers 13 and 14 and a magnetoresistive element 15. The layer 13 is preferably a highly conductive material belonging to the class of those materials exhibiting the highest conductivity, such as gold, and is placed in intimate contact with another highly conductive material 14 which need not be as conductive, however, as the material of the layer 13. For example, the layer 14 may be copper. The layers 13 and 14 are placed on a surface of sections 11 and 12 which is constructed of a nonmagnetic, relatively nonconductive material such as plastic or ferrite. The layer 13 and 14 together form two three-segment, generally U-shaped sections. The outer U-shaped section may be viewed as ending at points 16 and 18, and the inner U-shaped section may be viewed as ending at points 16 and 17. The inner U-shaped section includes a magnetoresistive element but, depending on the type of head, it may be completely magnetoresistive or it may be a single-turn, purely conductive, element. The points 16 and 17 are externally connected to leads 19 and 20, and the points 17 and 18 are internally interconnected. For purposes of illustration, a wire is shown as interconnecting points 17 and 18, but alternatively, the depositing operation would merely close the gap between points 17 and 18. When the sections 11 and 12 are closed together, a plane 21 is defined. This is the starting surface prior to a finishing operation for forming a spherical surface contour generally indicated by the dashed line 22. The process of removing material from the top plane 21 to the curved plane 22 necessarily results in the rupture of the middle segment of the outer section.
The removal of the material is achieved by rotating the head 10 about a central axis 36 passing through the planes 21 and 22. The point at which the middle segment of the outer section is ruptured is monitored through leads 19 and 20 by a resistance bridge arrangement to be described. It is necessary, therefore, to make available to the bridge signals from the lines 19 and 20 during rotation of the head 10. This is accomplished by a pair of slip rings 23 and 24, each contacted by a plurality of brushes 25 and 26. As is well known in the art, a very accurate resistance measuring instrument is the Kelvin bridge; for example, one known commercially as the Keithley Ohmmeter. The Kelvin bridge's accuracy is achieved by providing four input terminals to measure an unknown quantity X. Two of the four terminals of the bridge are connected to the upper commutating ring or slip ring 23 via two pairs of brushes 25, each being connected together to reduce noise and improve sensitivity. Similarly, the other two bridge terminals are connected to the lower commutation ring or slip ring 24 by two pairs of brushes 26. The bridge provides an output through an amplifier 27 indicating by a null that the unknown resistance may be calculated from the values of variable resistors A, B and R in accordance with the relation ##EQU1## (if the ratio A/B is the same as the ratio a/b). In normal operation, variable resistors A and B are preset in the range of the expected resistance value, and resistance R is varied until a null occurs. This may be performed by a motor 31 driven by the signal from the amplifier 27. As long as there is a signal from the amplifier 27, resistance R will be adjusted one way or the other, depending upon the signal polarity. Eventually the resistance R will be adjusted to provide a null from amplifier 27, and the unknown resistance X may be calculated.
This calculation is performed by the controls shown in FIGS. 2A-2C which will now be described. The positions of the resistors A, B and R are sensed by position indicators 28, 29 and 30 which place corresponding position signals on lines A, B and R of bus 35. The contacts of a switch 33 are also connected to the bus 35 via a wire 34. This switch is operated once for every revolution of cam 32 connected to the central axis 36 of the head 10.
Detailed Description of Structure
Referring now to FIG. 2A, there is illustrated one logic configuration capable of performing a calculation for determining the unknown resistance X. If desired, other configurations, or an appropriately programmed computer such as an IBM 1800 Data Processing System, may be substituted. For simplicity, the following explanation assumes the transfer of digital information through single blocks actually representing multiple parallel or serial positions. Signals on the bus 35 from the bridge are gated into AND circuits 201, 202 and 203 when a measure and store signal occurs on line 211 from additional controls in FIG. 2C, to be explained. The output of AND circuit 201 digitally represents the setting of resistor A, the output of AND circuit 202 digitally represents the setting of resistor B, and the output of AND circuit 203 digitally represents the setting of resistor R. The divide block 204 digitally calculates the ratio A/B and the multiple block 205 multiplies this ratio times R to give the digital quantity ##EQU2## which is then supplied to a zero detector 206, a comparator 207 and an X storage register 200. In the foregoing, it will be understood that digital representations could instead be analog. The output of the zero detector 206 is sensed by the AND circuit 212 whenever there is a measure and store signal on line 211 to give an output indicating when the quantity X equals zero, an abnormal condition. An XLim quantity, representing a predetermined resistance value, is stored in a register 210 via AND circuit 209 from an external entry mechanism such as a keyboard 208. The XLim register 210 contents and the calculated quantity X are compared in a comparator 207 and a signal occurs on line 219 when the X quantity equals XLim and a measure and store signal occurs. Line 219 remains activated until X is less than XLim. The calculated quantity X is also stored in the X register 200, which is reset by every measure and store signal on line 211, and is gated by a signal on a display line 214 through AND circuit 215 to an X display 216 or an X recorder 217 or other visual display or recording mechanism.
FIG. 2B shows a circuit for counting the number of head 10 rotations. In FIG. 1, the cam 32 operates the switch 33 to provide a single signal on the line 34 for each head rotation. In FIG. 2B, the output of AND circuit 221 sets a flip-flop 220 to the one state whenever a head rotation signal occurs on line 34 and then disables the AND circuit 221 via the zero output of the flip-flop 220. The one output of the flip-flop 220 causes a pulse from the single-shot 222 to step a three-position ring counter 223. The output of the single-shot 222 also resets the flip-flop 220 to enable it to receive the next head rotation signal. When the ring counter 223 output is either one or two, there will be an output n≠ 3 on line 225 from the OR circuit 224. This occurs for the first and second turns of the heads and multiples thereof. There will be an output n= 3 on the line 226 when the ring counter 223 is set to position three (which occurs every third turn of the head).
Referring to FIG. 2C, there is shown a logic diagram for utilizing and generating control signals necessary to the operation of the circuits of FIGS. 2A and 2B. Initially, all flip-flops and counters are reset by a signal from line 246 occurring at the end of a previous cycle of operation. A start signal on line 227 from an external source (not shown) sets the flip-flop 218 to the one condition, enabling AND circuit 228 to pass a series of clock pulses from a clock 223 which step a ring counter 236 from position to position in sequence. As the ring counter 236 is stepped, AND circuits 229-234 are enabled, one at a time, to pass a pulse from clock 235. Flip-flop 239 is set to place a signal on the line 244 and initiate a downfeed grind when the ring counter 236 is in position a and a clock pulse occurs from the clock 235. AND circuit 230 causes a measure and store signal to occur on the line 211 at ring counter position b, upon the occurrence of a clock pulse from clock 235, after single-shot 237 supplies an initial store pulse or if a flip-flop 240 (indicating three head rotations) has been previously set to the one state. At ring counter position b, flip-flop 241 is set to the one state when X=XLim. When ring counter 236 output c occurs, AND circuit 231 causes a display signal to appear on the output line 214 and AND circuit 242 is also enabled. AND circuit 242 is utilized if flip-flop 241 was previously set to the one state (if a limit indication X=XLim occurred on signal line 219 to AND circuit 234) to cause a retract grind signal on line 245 and, after a delay determined by delay circuit 243, to provide a signal on line 246 resetting all flip-flops and counters. At ring counter output d, the flip-flop 240 is held in the reset position via AND circuit 232 if the number of head turns has not yet reached three. At ring counter output e, the flip-flop 240 is set to the one state by an AND circuit 233, during a previous cycle of the ring counter 236, when there is an n=3 signal on line 226 indicating that a third head turn has occurred.
Referring now to FIG. 3A, there is shown a detailed view of a tool utilizing the invention. The head 10 is mounted in a collet 301 and connected via leads 302 to connectors attached to brushes 25 in contact with commutating or slip rings 23 and 24. Only the upper set 25 of two sets of brushes 25 and 26 is shown. This will be better understood if reference is made to FIG. 3B which is a cross-section through plane 3B--3B in FIG. 3A. A supporting, rotating armature 303 is shown surrounding, and attached to, a drive shaft 305. Upper brush assembly 25 and lower brush assembly 26 are stationary in a support 350 while the upper slip ring 23 and the lower slip ring 24 rotate with the armature assembly 303. Bearings are provided between the shaft 305 and a portion 304 of the support 350. The stationary support 350 is fastened to a base member 312 by means of bolts 311 or other fasteners. The shaft 305 is turned in the direction shown by a belt 307 which is driven by a motor 310. For illustration, pulleys 306, 308 and 309 are shown, but it is understood that these pulleys and the belt 307 may be replaced by a gear mechanism or the like. The shaft 305 also carries the cam 32 which operates the switch 33 to supply signals on line 34 for every turn of the shaft 305. The entire mechanism so far described may be mounted on a mounting plate 313 which is vertically movable relative to a stationary plate 314 restricted by guides 317 and 318. When plates 313 and 314 move toward each other, the motion is called "downfeed" and "retract" when they move apart. The motion may be obtained by means of a hydraulic actuator 315 driving a shaft 316 or equivalent mechanism such as solenoids, racks, etc. The vertical movement along an axial line through shaft 305 brings the head 10 into contact with a contoured surface of an illustrative grinding wheel 301 while the head is rotated by the motor 310. It will be understood that the grinding wheel 300 could instead be brought into contact with the head 10 by axially moving the grinding wheel toward the head while the head remains in a fixed vertical position. As an alternative, the grinding wheel 300 could be replaced by lapping tape or by other abrasive removal techniques such as abrasive blasting. The grinder may be a Gallmeyer and Livingston Model 350. The head is illustratively turned at 100 revolutions per minute, and, if lapping tape is used, it would be drawn lengthwise and also oscillated widthwise. The entire operation takes on the order of 30 to 45 seconds.
DETAILED DESCRIPTION OF OPERATION
The operation of the invention will now be described with reference to FIGS. 2A-2C. It will be understood that the descriptive operations control signals causing corresponding operations effecting FIGS. 1 and 3A.
Referring first to FIG. 2C, all counters and flip-flops are in the reset condition, and a quantity XLim=X is entered into the XLim register 210. A start signal 227 sets the flip-flop 218 to the one state, supplying clock pulses 235 to the ring counter 236 and sequentially selecting AND circuits 229-234. A signal on output line 244 initiates a down feed grind to begin the grinding operation. The next step of the ring counter 236 causes a signal on line 211, measure and store, after there have been three turns of the head as indicated by a signal on line 226 from FIG. 2B. The signal on the line 211, measure and store, causes (FIG. 2A) the quantities A, B and R on the bus 35 from the bridge to be calculated ##EQU3## and compared in the comparator 207 to the quantity X stored in the X limit register 210. The X register 200 is reset at this time, and the currently calculated quantity X is then stored therein. It is assumed that the first comparison will indicate that the grinding has not yet reached the desired relationship of resistance X to desired resistance (XLim=X). There will, thus, not be an output on the X=XLim line 219. When the ring counter 236 steps to the c position, the AND circuit 231 will generate a signal on display line 214 which activates AND circuit 215 to send the current contents of X register 200 to the X display 216 and the X recorder 217. When the ring counter 236 reaches d, the number of head turns as indicated by a signal on the lines 225 and 226 are tested and the flip-flop 240 is accordingly set. There will be another output from the flip-flop 240 only if the number of turns as indicated by a signal on line 226 equals three, in which case there will be another measure and store signal 211. Otherwise, there will not be a measure and store signal. When the ring counter 236 again steps to position b, flip-flop 241 will be set to the one state only if the quantity calculated and stored in the X register 200 equals or exceeds the quantity X stored in the X limit register 210. The operation is repeated if this does not occur. If, however, XLim=X, the flip-flop 241 is set to the one state, and the AND circuit 242 will, at the next c time of the ring counter 236, cause the grinder to retract. Subsequently, all flip-flops and counters are reset.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
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A head is moved toward and rotated against an abrasive while its resistance is monitored by a four-lead bridge. Two leads from the head are connected to two slip rings, and each slip ring has two pairs of brushes, each wire from the bridge going to a different brush pair. The number of head rotations is counted and head resistance is monitored by the bridge at predetermined counts. Head movement toward the abrasive is terminated when a predetermined head resistance is detected by the bridge.
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FIELD OF THE INVENTION
The invention relates to a device, which is combined with a circular knitting machine, for producing the closure of tubular hosiery articles produced by this machine.
BACKGROUND OF THE INVENTION
Attempted solutions to this problem have not proved satisfactory. Solutions in which the articles are transferred from the production machine to a separate device have proved somewhat unsatisfactory and/or too costly and/or too bulky, especially if combined with each single machine.
SUMMARY OF THE INVENTION
The invention solves these problems, and also achieves other objects and advantages, which are apparent from the text below.
The device in question—for closing the end of hosiery articles on the same circular machine on which they are produced—is of the type of those that adopt a sector—generally semicircular—to transfer the stitches from a first needle arc to a second opposed needle arc, as defined in the Italian patent application no. FI2006A000025 of 21 Jan. 2006, the contents of which are incorporated herein by reference.
According to the invention, elements terminating in a bifurcate way are provided in said sector, each of which flanks—inside respective sinkers—the relevant needle of the first arc; each of said shaped elements terminating in a bifurcate way superiorly presents a fork projection embracing the needle and forming a rear recess and two front recesses, suitable to engage an end stitch formed by said needles.
There are also provided:
means to raise and lower the needles of the first arc to unload said end stitch, which thus remains engaged on said fork projection;
means to rotate said sector through approximately 180° and to take the end stitches engaged on said recesses to correspond with the needles of the second arc; and
means to raise said needles of the second arc to a retained level so that each of them maintains the stitch formed thereby and to engage also the corresponding stitch engaged on said recesses and to thus form ranks of double closing stitches with the needles of the second arc.
Advantageously said fork projection presents the upper surface inclined.
A profile can also be provided, suitable to ensure raising of the latch of the needle, during initial lowering of the needle to release the stitches that are to be transferred from the first needle arc to the second needle arc, regardless of the presence of the released stitch.
A means may be provided for maintaining the shaped elements in an excluded lowered arrangement until the time of end closing of the article and for lifting the shaped elements such that the shaped elements engage the stitches on the fork shaped projections.
A unit may be provided on which the sector is articulated. The assembly may be capable of rotating with the needle cylinder and to be raised and lowered axially with respect to the cylinder to reach a lowered idle position and a raised active position and to engage the stitches of the needles of the first arc and to transfer the stitches to the needles of the second arc such that the needles of the second arc engage an end stitch thereof.
A tubular member may be provided for following raising and rotation of the needle cylinder. The tubular member may be partially rotated with respect to the needle cylinder for controlling overturning of the sector.
The means for moving the sinkers may raise and lower the sinkers. The means for moving the sinkers and the means for raising the needles may be controlled to form tight end stitches and at least one final loose stitch in the first needle arc, and to form with the needles of the second needle arc close stitches tightened on both edges that are in a closing step and at least one final loose stitch.
The invention also relates to a process for closing the end of hosiery articles on the same circular machine that produced them, with a sector—mostly semicircular—for transfer of the stitches from a first needle arc to a second opposed needle arc.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIGS. 1 to 3 are axial sectional views of the upper part of the needle cylinder with accessories and with the device of the invention, in three subsequent arrangements;
FIGS. 4 , 5 and 6 are local sectional views according to IV-IV, V-V and VI-VI of FIG. 1 ;
FIG. 7 is a sectional view of the area indicated by the arrow f VII of FIG. 1 , in a step prior to transfer;
FIGS. 8 and 9 are local sectional views in arrangements subsequent to that of FIG. 7 ;
FIGS. 10 , 11 and 12 are sectional views that show, analogously to FIG. 7 , two of the arrangements prior to transfer;
FIGS. 13 , 14 and 15 are sectional views showing the area indicated by the arrow f XI , of FIG. 3 , in subsequent operating steps implemented after transfer;
FIGS. 16 and 17 are plan views of a portion of the semicircular sector isolated, without stitches and with stitches;
FIG. 18 is a local sectional view according to XVIII-XVIII of FIG. 16 ; and
FIG. 19 is an enlarged detail view of FIG. 18 , viewed from the line XIX-XIX of FIG. 18 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the reference 1 indicates a motor cylinder which rotates to draw in rotation—by means of tabs 3 or equivalent members—the needle cylinder 5 , in the external longitudinal channels 5 A of which the needles 7 X and 7 Y slide. The conventional collar 9 with radial channels 9 A for sliding of the sinkers 11 is combined superiorly with the needle cylinder 5 . Arrangement is customary.
The reference 13 indicates a cylinder which is coaxial and which rotates with the motor cylinder 1 and with the needle cylinder 5 ; two diametrically opposed supports 15 are provided on the upper edge 13 A thereof, on which a semicircular sector 19 is pivoted with diametrical pins 17 ; said sector 19 is capable of overturning through approximately 180° to be arranged alternately corresponding to a first approximately semicircular needle arc 7 X and at a second and opposed needle arc 7 Y. To control overturning of the sector 19 alternately, a cylinder 21 is provided around the cylinder 13 ; the upper edge 21 A of the cylinder 21 presents at least one toothing 23 which meshes with a toothing 24 of the sector 19 and coaxial to the pins 17 . The cylinder 21 can rotate with the cylinders 13 and 5 through the action of the motor cylinder 1 , as a constraining pin 27 is provided. The cylinder 21 can be angularly displaced by a few degrees with respect to the cylinder 13 , to control overturning of the sector 19 through the toothings 23 and 24 .
The two cylinders 13 and 21 and the sector 19 can be raised and lowered together axially with respect to the needle cylinder, for purposes that will be explained below; this is permitted by a vertical slot 1 Y of the cylinder 1 , through which the pin 27 that draws the two cylinders 13 and 21 in rotation passes. Also the needle cylinder 5 with the sinkers 11 can be axially displaced, to obtain prompt dimensional variations of the stitches of the tubular knitted fabric of the article. The cylinder 21 presents a limited slot 21 X ( FIG. 5 ), so that it can be made to rotate with respect to the other cylinders 13 and 1 .
A customary tubular guide 31 is provided inside the cylinder 13 , to implement pneumatic tensioning of the article being formed, with a suction current.
Each sinker 11 presents the customary shaped slot 11 A, to cooperate with the hook of the needle 7 X and 7 Y, for customary knitting of the tubular article of the sock or other equivalent article.
At the end of forming of the tubular fabric, the toe of the article can be closed, if necessary after forming a pocket with the needles of the first arc, with continuous motion or with alternating motion of the needle cylinder. The sector 19 must then be overturned with the end edge formed by the first needle arc 7 X, until the last stitches formed by the needle arc 7 X are combined with the last stitches formed by the second needle arc 7 Y. This is implemented by the special structure of the sector 19 , suitable to cooperate with the sinkers and with the needles.
The sector 19 —according to the invention—can be moved between a lowered and inactive position below the area in which the shaped slots 11 A of the sinkers 11 are located, and a raised and active position ( FIGS. 2 , 8 , 12 ) almost at the level of said shaped slots 11 A. In the lowered position and in the arrangement of the sector 19 in correspondence of to the needles of the first needle arc ( FIGS. 1 , 2 , 7 ), the circular machine can form the article in the conventional manner, with or without the end pocket for the toe to be closed.
The sector 19 , along the arcuate extension thereof, presents a plurality of radial appendages 25 , each terminating with a pair of radially extending shaped elements 25 F (see in particular FIG. 19 ); the two elements 25 F of each pair extend approximately radially to flank one of the needles 7 X of the first needle arc in the first arrangement ( FIGS. 1 and 2 ) and also one of the needles 7 Y of the second needle arc, in the second overturned arrangement ( FIG. 3 ) of the sector 19 ; the two shaped elements 25 F of each pair are located between the relevant needle 7 X and the two sinkers 11 which flank the needle and which cooperate therewith. The two shaped elements 25 F of each pair superiorly present—in the arrangement in correspondence of the first needle arc 7 X—a U-shaped projection 25 A which in the plan view extends in a radially oriented U-shape open toward the outside (see in particular FIGS. 16 to 18 ) with an upper edge 25 B which—when the sector 19 is in the raised arrangement of FIGS. 2 , 8 , 9 —approximately follows the profile of the shaped slot 11 A of the relevant sinker; said edge 25 B extends outward (with respect to the axis of the cylinders) with two edges 25 C sunken toward the end of the element 25 , 25 F following approximately laterally the bottom of the slot 11 A of the sinkers but projecting slightly with respect to said slot 11 A.
In the placement described, with the element 25 , 25 F from the arrangement of FIGS. 7 and 10 with the needles 7 X maintained lowered without taking up thread, the sinkers 11 are moved away according to f 19 ( FIG. 11 ). In this manner, the last stitch Ml remains engaged on the element 25 , 25 A, so that the fabric ending with the rank of stitches Ml can be easily transferred to the needles 7 Y of the second needle arc, with overturning of the sector 19 about the pins 17 .
The needles 7 Y of the second arc are maintained idle and lowered, with the last stitch Mo engaged thereon. The needles 7 X of the first needle arc are lowered without taking up thread, so that the last formed stitches Ml remain engaged as specified above between the recesses 25 C and 25 X; these stitches Ml are stressed by pneumatic tensioning through suction from the tube 31 . To ensure that the latch of the needles 7 X is lowered on the end thereof, said element 26 is provided, which promptly ensures raising of the latch of the needles 7 X that start to be lowered; therefore the needles 7 X safely release the stitch Ml, which remains retained between the recesses 25 X and 25 C.
At this point—to actuate transfer of the stitches Ml to the needles 7 Y—the cylinder 13 and therefore the sector 19 are raised and through the toothings 23 , 24 the sector 19 is overturned through 180° about the pins 17 drawing the stitches Ml, which remain pneumatically tensioned and thus in an elongated and also enlarged arrangement, being engaged on the respective projections 25 A extending with a radially oriented U-shape.
After overturning of the sector 19 (as indicated by the broken lines in FIG. 3 ) until reaching the position indicated in FIGS. 3 , 13 , 14 , the shaped elements 25 A are positioned so as to embrace the relevant needles 7 Y of the second needle arc. At this point, the needles 7 Y of the second needle arc are raised inside the space of the respective projections 25 A to a limited level (retained level) in which said needles 7 Y maintain the stitch Mo of the last rank of stitches produced thereby but they come ( FIG. 14 ) so that they are able also to engage—together with the stitch Mo—the relevant stitch Ml, which is enlarged by the respective projection 25 A and by the pneumatic tensioning applied by the tube 31 ; in this manner the stitches Mo and Ml are both engaged by the relevant needles 7 Y of the second arc. At this point said needles 7 Y of the second arc—with alternating motion or with continuous motion, and with final cut of the thread, form further ranks of stitches, in particular tight stitches and a final loose stitch or another solution, to in any case prevent unraveling of the finishing ranks of the article, for example closure of the final end of the article. The article—when finished—is released.
With inverse movements, all parts are returned to the initial conditions.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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To transfer the stitches from a first needle arc ( 7 X) to a second opposed needle arc ( 7 Y), a overturnable semicircular sector ( 19 ) presents elements ( 25 ) terminating in a bifurcate way ( 25 F) (flanking inside the respective sinkers ( 11 ) the relevant needle ( 7 X) of the first arc), each of which has an upper fork projection ( 25 A) embracing the needle ( 7 X) and forming a rear recess ( 25 X) and a front recess ( 25 C) suitable to engage an end stitch (M 1 ) formed by the corresponding needle ( 7 X), said stitch (M 1 ) then being transferred and engaged on a corresponding needle ( 7 Y) of the second needle arc.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of making absorbable surgical threads and can be used in medicine biology and veterinary science.
At present absorbable threads are widely used in medical practice. They do not require such a manipulation as thread removal and provide for a proper cosmeticability of the cicatrices resulting from surgical operations.
In order to be successfully used, the absorbable threads should possess a sufficient strength. However, conventional absorbable threads are of inadequate mechanical strength. Therefore efforts are constantly undertaken to develop novel methods of making absorbable threads based on cellulose which are characterized by a higher mechanical strength.
2. Description of the Prior Art
There is known in the art a method of making surgical threads (U.S. Pat. No. 2,537,979) which consists in oxidizing cellulose with nitrogen dioxide. However, as distinct from the method described above, the oxidation here is carried out till the content of carboxyls is 4 to 12.5%. The time of making said surgical sutures is 64 hours. The process is carried out at a temperature of 25° C. Having been treated with nitrogen dioxide, the threads are washed with distilled water and dried. The ratio between the value of the tensile strength of the absorbable threads produced due to the treatment of the initial threads and the value of the tensile strength of the initial threads prior to the treatment is 36.8 to 43.5%.
As a result of the oxidation of the cellulose threads with nitrogen oxides there occurred a destruction of the supermolecular structure of the cellulose threads because of inculation of large molecules of N 2 O 4 , rupture of intermolecular hydrogen bonds cellulose-cellulose and cellulose-water-cellulose, substitution of a part of C 6 H 2 OH-groups by larger C 6 OOH-groups. Therefore, the surgical absorbable threads produced by said method are of a low mechanical strength and of a high swelling property in biological media.
As noted in the above Patent, such a thread completely lost its strength within 5 days. The testing was carried out in a phosphate buffered solution having a pH of 7.5 at a temperature of 37° C. where a thread is absorbed slower than in living tissues. No testing of the thread placed in living tissues was carried out.
Thus, the above-described method does not provide for the manufacture of absorbable surgical threads having a high mechanical strength and a low swelling property in beological media.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a method of making absorbable surgical threads based on oxidized cellulose, which method makes it possible to upgrade the quality of the absorbable surgical threads, i.e. to improve their mechanical strength and to reduce their swelling property both in water and in biological media.
Other objects and advantages of the present invention will be clear from the following description.
The above and other objects of the invention are attained by that there is provided a method of making absorbable surgical threads consisting in treating cellulose threads with nitrogen oxides, wherein, according to the invention, the threads treated with the nitrogen oxides are further treated with a protophilic solvent for 1 to 2 hours at a room temperature and then held at a temperature of 70° to 90° C. for 1 to 2 hours.
The above treatment of the oxidized cellulose threads provides for a higher degree of ordering of their supermolecular structure, for a larger amount of hydrogen bonds between macromolecules of the oxidized cellulose as well as between the latter and water bonded with cellulose. As a result, the mechanical strength of the oxidized threads improves and the selling property of these same threads in water and biological media decreases.
It is expedient to use as the protophilic solvent a 2 to 10% water solution of ionogenic compound selected from the group consisting of sodium chloride, calcium chloride, calcium acetate and acetic acid; a 2 to 10% aqueous solution of an amphiprotonic polyhydric alcohol selected from the group consisting of glycerol, pentaerytritol, mannite, sorbitol, glucose, saccharose and dextrose; an organic solvent selected from the group consisting of dimethyl formamide, dimethyl sulfoxide and dimethyl acetamide.
DETAILED DESCRIPTION OF THE INVENTION
Absorbable surgical sutures according to the invention were produced in the following way.
Cellulose threads are oxidized with nitrogen oxides in a conventional manner. The cellulose threads may be threads from cotton, flax, viscose, high-module viscose, polynose etc which are characterized by a wide range of thickness and an amount of additions.
The oxidized threads are thoroughly washed with water, whereupon wet threads are placed into a stainless steel reaction vessel having a capacity of 20 liters and filled with a preliminarily prepared protophilic solvent. The threads are held in this reaction vessel for 1 to 2 hours.
The protophilic solvent may be a 2 to 10% water solution of ionogenic compounds such as sodium chloride, calcium chloride, calcium acetate and acetic acid; a 2 to 10% aqueous solution of an amphiprotic polyhydric alcohol such as glycerol, pentaerytritol, mannite, sorbitol, glucose, saccharose and dextrose as well as an organic solvent such as dimethyl formamide, dimethyl sulfoxide, or dimethyl acetamide.
Thereupon the threads are withdrawn from the reaction vessel and placed into a stainless steel chamber having a capacity of 20 liters and blown through with air heated up to a temperature of 70° to 90° C. In this chamber the threads are held for 1 to 2 hours.
The method of the present invention makes it possible to produce absorbable surgical threads whose mechanical strength is 83 to 105% of cellulose threads before oxidation.
The swelling property of the sutures produced according to the invention is reduced down to 20 to 60% as compared with the swelling property of the initial non-oxidized cellulose threads.
EXAMPLE 1
Absorbable surgical sutures were produced according to the invention in the following way.
2.4 kg of complex viscose threads having a size of 60/18 and a tensile strength of 4.75 kg were oxidized with nitrogen oxides in a conventional manner. The oxidized threads were thoroughly washed with water and then tested to determine the content of carboxyls, fixed nitrogen, relative humidity, tensile strength, and degree of swelling in water.
The results of the testing were the following:
______________________________________content of carboxyls, % 6.5content of fixed nitrogen, % 0.12relative humidity, % 12.8tensile strength, kg 3.35degree of swelling in water, % 59.5______________________________________
Thereupon, the wet threads were placed in a reaction vessel having a capacity of 20 liters and filled with a 10% of an aqueous solution of sorbitol in an amount of 15 liters. The threads were held in the reaction vessel for 2 hours, whereupon they were withdrawn therefrom, and placed into a chamber blown through with air heated to a temperature of 80° C., in which chamber the threads were again held for 1.5 hours.
Thus treated threads were again tested to determine the tensile strength and degree of swelling.
The results of the testing are given below:
______________________________________tensile strength, kg 5.0degree of swelling, % 31.1______________________________________
The ratio between the value of the tensile strength of the oxidized treated threads to the value of the tensile strength of the oxidized non-treated threads was 154%, and the ratio between the value of the degree of swelling of the oxidized treated threads to the value of the degree of swelling of the oxidized non-treated threads was 52.3%.
The ratio between the value of the tensile strength of the oxidized treated threads to the value of the tensile strength of the initial viscose threads was 105.3%.
EXAMPLE 2,3
Absorbable surgical threads according to the invention were produced in the following way.
Complex viscose threads having initial properties similar to those described in Example 1 were subjected to oxidation and then to treatment according to the procedure described in Example 1.
The properties of the oxidized non-treated threads are similar to those of Example 1.
______________________________________Teatment conditions Temperature DurationNo of Protophilic Time of hold- of treat- of treat-Example solvent ing, hours ment, °C. ment, hours______________________________________2 2% sodium 2 80 1.5 chloride3 2% calcium 2 80 1.5 chloride______________________________________
______________________________________Properties of the oxidized treated threads Ratio between the indices of oxidized Ratio between treated threads and the value of the the indices of oxi- tensile strength Degree dized non-treated of oxidized non- of threads treated threadsNo of Tensile swel- Tensile Degree and the tensileExam- strength, ling, strength, of swel- strength of ini-ple kg % % ling, % tial threads, %______________________________________2 4.95 36.0 152.0 60.2 104.23 4.60 36.0 141.6 60.5 96.8______________________________________
EXAMPLES 4-12
Absorbable surgical threads according to the invention were produced in the following way.
2.4 kg of viscose threads having a size of 60/18 and a tensile strength of 4.75 kg were oxidized and further treated in accordance with the procedure described in Example 1.
The properties of the oxidized non-treated threads are similar to those of Example 1.
______________________________________Treatment conditions Temper- Time of Time duration ature of treat-No of Protophilic of holding, treat- ment,Example solvent hours ment, °C. hours______________________________________4 6% sodium 1.5 80 1.5 chloride5 10% calcium 1.0 70 2.0 chloride6 6% glycerol 1.5 80 1.57 6% penta- 1.5 80 1.5 erytritol8 2% sorbitol 2.0 90 1.09 10% sorbitol 1.0 70 2.010 2% glucose 2.0 90 1.011 6% saccharose 1.5 80 1.512 10% dextrose 1.0 70 2.0______________________________________
______________________________________Properties of the oxidized treated threads Ratio between the Ratio between indices of oxidized the value of the treated threads and tensile strength the indices of oxi- of oxidized non- Degree dized non-treated treated threads of threads and the valueNo of Tensile swel- Tensile Degree of the tensileExam- strength, ling, strength, of swel- strength if ini-ple kg % % ling, % tial threads, %1 2 3 4 5 6______________________________________4 4.95 35.5 152.5 59.6 102.05 4.70 36.0 145.0 60.5 99.06 4.15 42.5 128.0 71.4 87.47 4.15 43.0 128.0 72.3 87.48 5.0 31.1 154.0 52.3 105.09 5.0 31.2 154.0 52.4 105.010 4.5 44.5 138.0 74.8 94.611 4.3 42.0 132.0 70.6 90.512 4.2 42.5 129.0 71.4 88.5______________________________________
EXAMPLE 13
Absorbable surgical threads according to the invention were produced in the following way.
2.4 kg of complex viscose threads having a size of 60/18 and a tensile strength of 5.95 kg were oxidized and further treated in accordance with the procedure described in Example 1.
Properties of the oxidized non-treated threads:
______________________________________content of carboxyls, % 9.0content of fixed nitrogen, % 0.1relative humidity, % 9.0tensile strength, kg 4.05degree of swelling in water, % 57.6______________________________________
The conditions of the treatment were as follows:
______________________________________protophilic solvent 4% acetic acidtime of holding, hours 2temperature of heat treatment, °C. 80time of heat treatment, hours 1.5______________________________________
The properties of the oxidized treated threads were as follows:
______________________________________tensile strength, kg 5.35degree of swelling, % 45.0ratio between the value of the ten-sile strength of the oxidizedtreated threads to the value ofthe tensile strength of the oxi-dized non-treated threads, % 132.0ratio between the value of thedegree of swelling of the oxidizedtreated threads and the valueof the degree of swelling of theoxidized non-treated threads, % 78.0ratio between the value of the ten-sile strength of the oxidizedtreated threads to the valueof the tensile strength of theinitial threads, % 90.0______________________________________
EXAMPLES 14-23
Absorbable surgical threads were produced according to the method of the present invention.
2.4 kg of high-modull viscose having a size of 20/6 and a tensile strength of 5.60 kg were oxidized and further treated in accordance with the procedure described in Example 1.
The properties of the oxidized non-treated threads were the following:
______________________________________content of carboxyls, % 5.5content of fixed nitrogen, % 0.1relative humidity, % 7.6tensile strength, kg 4.45degree of swelling in water, % 61.0______________________________________
______________________________________Treatment conditions Temperature Time ofNo of Protophilic Time of hold- of treat- treatment,example solvent ing, hours ment, °C. hours______________________________________14 dimethyl 2.0 80 2.0 sulfoxide15 dimethyl 2.0 90 1.0 formamide16 dimethyl 1.5 80 1.5 formamide17 dimethyl 1.0 70 2.0 formamide18 dimethyl 2.0 90 1.0 sulfoxide19 dimethyl 1.5 80 1.5 sulfoxide20 dimethyl 1.0 70 2.0 sulfoxide21 dimethyl 2.0 90 1.0 acetamide22 dimethyl 1.5 80 1.5 acetamide23 dimethyl 1.0 70 2.0 acetamide______________________________________
______________________________________Properties of the oxidized treated threads: Ratio between Ratio between the the value of indices of oxidized the tensile treated threads and strength of the indices of oxi- oxidized non- Degree dized non-treated treated threads of threads and theNo of Tensile swel- Tensile Degree tensile strengthExam- strength, ling, strength, of swel- of initialple kg % % % threads, %______________________________________14 5.85 38.0 131.5 62.2 104.515 5.2 42.0 127.0 68.8 93.716 5.3 42.0 119.0 68.8 94.717 5.25 43.0 118.0 70.5 94.518 5.85 38.0 131.5 62.3 104.519 5.8 38.5 130.2 63.1 103.520 5.85 38.0 131.5 62.3 104.521 5.25 42.0 118.0 68.8 94.522 5.4 40.0 121.5 65.6 96.623 5.3 41.5 119.0 68.0 94.7______________________________________
While particular embodiments of the invention have been shown and described, various modifications thereof will be apparent to those skilled in the art and therefore it is not intended that the invention be limited to the disclosed embodiments or to the details thereof and the departures may be made therefrom within the spirit and the scope of the invention as defined in the claims.
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A method of making absorbable surgical threads consists in treating cellulose threads with nitrogen oxides, then treating these threads with a protophilic solvent for 1 to 2 hours at a room temperature and holding them at a temperature of 70° to 90° C. for 1 to 2 hours.
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PRIORITY AND RELATED APPLICATIONS
This patent application is related to, incorporates by reference, and claims the priority benefit of U.S. Provisional Application 60/528,631, entitled “DOCUMENT REGISTRATION”, filed Dec. 10, 2003.
FIELD OF THE INVENTION
The present invention relates to computer networks, and in particular, to registering documents in a computer network.
BACKGROUND
Computer networks and systems have become indispensable tools for modern business. Modern enterprises use such networks for communications and for storage. The information and data stored on the network of a business enterprise is often a highly valuable asset. Modern enterprises use numerous tools to keep outsiders, intruders, and unauthorized personnel from accessing valuable information stored on the network. These tools include firewalls, intrusion detection systems, and packet sniffer devices. However, once an intruder has gained access to sensitive content, there is no network device that can prevent the electronic transmission of the content from the network to outside the network. Similarly, there is no network device that can analyze the data leaving the network to monitor for policy violations, and make it possible to track down information, leaks. What is needed is a comprehensive system to capture, store, and analyze all data communicated using the enterprises network.
SUMMARY OF THE INVENTION
A document accessible over a network can be registered. A registered document, and the content contained therein, cannot be transmitted undetected over and off of the network. In one embodiment, the invention includes maintaining a plurality of stored signatures, each signature being associated with one of a plurality of registered documents, intercepting an object being transmitted over a network, calculating a set of signatures associated with the intercepted object, and comparing the set of signatures with the plurality of stored signatures. In one embodiment, the invention can further include detecting registered content from the registered document being contained in the intercepted object, if the comparison results in a match of at least one of the signatures in the set of signatures with one or more of the plurality of stored signatures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:
FIG. 1 is a block diagram illustrating a computer network connected to the Internet;
FIG. 2 is a block diagram illustrating one configuration of a capture system according to one embodiment of the present invention;
FIG. 3 is a block diagram illustrating the capture system according to one embodiment of the present invention;
FIG. 4 is a block diagram illustrating an object assembly module according to one embodiment of the present invention;
FIG. 5 is a block diagram illustrating an object store module according to one embodiment of the present invention;
FIG. 6 is a block diagram illustrating an example hardware architecture for a capture system according to one embodiment of the present invention;
FIG. 7 is a block diagram illustrating a document registration system according to one embodiment of the present invention;
FIG. 8 is a block diagram illustrating registration module according to one embodiment of the present invention; and
FIG. 9 is a flow diagram illustrating object capture processing according to one embodiment of the present invention.
DETAILED DESCRIPTION
Although the present system will be discussed with reference to various illustrated examples, these examples should not be read to limit the broader spirit and scope of the present invention. Some portions of the detailed description that follows are presented in terms of algorithms and symbolic representations of operations on data within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the computer science 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 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 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. 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, it will be appreciated that throughout the description of the present invention, use of terms such as “processing”, “computing”, “calculating”, “determining”, “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.
As indicated above, one embodiment of the present invention is instantiated in computer software, that is, computer readable instructions, which, when executed by one or more computer processors/systems, instruct the processors/systems to perform the designated actions. Such computer software may be resident in one or more computer readable media, such as hard drives, CD-ROMs, DVD-ROMs, read-only memory, read-write memory and so on. Such software may be distributed on one or more of these media, or may be made available for download across one or more computer networks (e.g., the Internet). Regardless of the format, the computer programming, rendering and processing techniques discussed herein are simply examples of the types of programming, rendering and processing techniques that may be used to implement aspects of the present invention. These examples should in no way limit the present invention, which is best understood with reference to the claims that follow this description.
Networks
FIG. 1 illustrates a simple prior art configuration of a local area network (LAN) 10 connected to the Internet 12 . Connected to the LAN 10 are various components, such as servers 14 , clients 16 , and switch 18 . There are numerous other known networking components and computing devices that can be connected to the LAN 10 . The LAN 10 can be implemented using various wireline or wireless technologies, such as Ethernet and 802.11b. The LAN 10 may be much more complex than the simplified diagram in FIG. 1 , and may be connected to other LANs as well.
FIG. 1 illustrates a simple prior art configuration of a local area network (LAN) 10 connected to the Internet 12 . Connected to the LAN 10 are various components, such as servers 14 , clients 16 , and switch 18 . There are numerous other known networking components and computing devices that can be connected to the LAN 10 . The LAN 10 can be implemented using various wireline or wireless technologies, such as Ethernet and 802.11b. The LAN 10 may be much more complex than the simplified diagram in FIG. 1 , and may be connected to other LANs as well.
In FIG. 1 , the LAN 10 is connected to the Internet 12 via a router 20 . This router 20 can be used to implement a firewall, which are widely used to give users of the LAN 10 secure access to the Internet 12 as well as to separate a company's public Web server (can be one of the servers 14 ) from its internal network, i.e., LAN 10 . In one embodiment, any data leaving the LAN 10 towards the Internet 12 must pass through the router 20 . However, there the router 20 merely forwards packets to the Internet 12 . The router 20 cannot capture, analyze and store, in a searchable manner, the content contained in the forwarded packets.
One embodiment of the present invention is now illustrated with reference to FIG. 2 . FIG. 2 shows the same simplified configuration of connecting the LAN 10 to the Internet 12 via the router 20 . However, in FIG. 2 , the router 20 is also connected to a capture system 22 . In one embodiment, the router 20 splits the outgoing data stream, and forwards one copy to the Internet 12 and the other copy to the capture system 22 .
There are various other possible configurations. For example, the router 12 can also forward a copy of all incoming data to the capture system 22 as well. Furthermore, the capture system 22 can be configured sequentially in front of, or behind the router 20 , however this makes the capture system 22 a critical component in connecting to the Internet 12 . In systems where a router 20 is not used at all, the capture system can be interposed directly between the LAN 10 and the Internet 12 . In one embodiment, the capture system 22 has a user interface accessible from a LAN-attached device, such as a client 16 .
Capture System
One embodiment of the present invention is now described with reference to FIG. 3 . FIG. 3 shows one embodiment of the capture system 22 in more detail. The capture system 22 is also sometimes referred to as a content analyzer, content or data analysis system, and other similar names. In one embodiment, the capture system 22 includes a network interface module 24 to receive the data from the network 10 or the router 20 . In one embodiment, the network interface module 24 is implemented using one or more network interface cards (NIC), e.g., Ethernet cards. In one embodiment, the router 20 delivers all data leaving the network to the network interface module 24 .
The captured raw data is then passed to a packet capture module 26 . In one embodiment, the packet capture module 26 extracts data packets from the data stream received from the network interface module 24 . In one embodiment, the packet capture module 26 reconstructs Ethernet packets from multiple sources to multiple destinations for the raw data stream.
In one embodiment, the packets are then provided the object assembly module 28 . The object assembly module 28 reconstructs the objects being transmitted by the packets. For example, when a document is transmitted, e.g. as an email attachment, it is broken down into packets according to various data transfer protocols such as Transmission Control Protocol/Internet Protocol (TCP/IP) and Ethernet. The object assembly module 28 can reconstruct the document from the captured packets.
One embodiment of the object assembly module 28 is now described in more detail with reference to FIG. 4 . When packets first enter the object assembly module, they are first provided to a reassembler 36 . In one embodiment, the reassembler 36 groups—assembles—the packets into unique flows. For example, a flow can be defined as packets with identical Source IP and Destination IP addresses as well as identical TCP Source and Destination Ports. That is, the reassembler 36 can organize a packet stream by sender and recipient.
In one embodiment, the reassembler 36 begins a new flow upon the observation of a starting packet defined by the data transfer protocol. For a TCP/IP embodiment, the starting packet is generally referred to as the “SYN” packet. The flow can terminate upon observation of a finishing packet, e.g., a “Reset” or “FIN” packet in TCP/IP. If now finishing packet is observed by the reassembler 36 within some time constraint, it can terminate the flow via a timeout mechanism. In an embodiment using the TPC protocol, a TCP flow contains an ordered sequence of packets that can be assembled into a contiguous data stream by the reassembler 36 . Thus, in one embodiment, a flow is an ordered data stream of a single communication between a source and a destination.
The flow assembled by the reassembler 36 can then be provided to a protocol demultiplexer (demux) 38 . In one embodiment, the protocol demux 38 sorts assembled flows using the TCP Ports. This can include performing a speculative classification of the flow contents based on the association of well-known port numbers with specified protocols. For example, Web Hyper Text Transfer Protocol (HTTP) packets——i.e., Web traffic—are typically associated with port 80 , File Transfer Protocol (FTP) packets with port 20 , Kerberos authentication packets with port 88 , and so on. Thus in one embodiment, the protocol demux 38 separates all the different protocols in one flow.
In one embodiment, a protocol classifier 40 also sorts the flows in addition to the protocol demux 38 . In one embodiment, the protocol classifier 40 —operating either in parallel or in sequence with the protocol demux 38 —applies signature filters to the flows to attempt to identify the protocol based solely on the transported data. Furthermore, the protocol demux 38 can make a classification decision based on port number which is subsequently overridden by protocol classifier 40 . For example, if an individual or program attempted to masquerade an illicit communication (such as file sharing) using an apparently benign port such as port 80 (commonly used for HTTP Web browsing), the protocol classifier 40 would use protocol signatures, i.e., the characteristic data sequences of defined protocols, to verify the speculative classification performed by protocol demux 38 .
In one embodiment, the object assembly module 28 outputs each flow organized by protocol, which represent the underlying objects. Referring again to FIG. 3 , these objects can then be handed over to the object classification module 30 (sometimes also referred to as the “content classifier”) for classification based on content. A classified flow may still contain multiple content objects depending on the protocol used. For example, protocols such as HTTP (Internet Web Surfing) may contain over 100 objects of any number of content types in a single flow. To deconstruct the flow, each object contained in the flow is individually extracted, and decoded, if necessary, by the object classification module 30 .
The object classification module 30 uses the inherent properties and signatures of various documents to determine the content type of each object. For example, a Word document has a signature that is distinct from a PowerPoint document, or an Email document. The object classification module 30 can extract out each individual object and sort them out by such content types. Such classification renders the present invention immune from cases where a malicious user has altered a file extension or other property in an attempt to avoid detection of illicit activity.
In one embodiment, the object classification module 30 determines whether each object should be stored or discarded. In one embodiment, this determination is based on a various capture rules. For example, a capture rule can indicate that Web Traffic should be discarded. Another capture rule can indicate that all PowerPoint documents should be stored, except for ones originating from the CEO's IP address. Such capture rules can be implemented as regular expressions, or by other similar means.
In one embodiment, the capture rules are authored by users of the capture system 22 . The capture system 22 is made accessible to any network-connected machine through the network interface module 24 and user interface 34 . In one embodiment, the user interface 34 is a graphical user interface providing the user with friendly access to the various features of the capture system 22 . For example, the user interface 34 can provide a capture rule authoring tool that allows users to write and implement any capture rule desired, which are then applied by the object classification module 30 when determining whether each object should be stored. The user interface 34 can also provide pre-configured capture rules that the user can select from along with an explanation of the operation of such standard included capture rules. In one embodiment, the default capture rule implemented by the object classification module 30 captures all objects leaving the network 10 .
If the capture of an object is mandated by the capture rules, the object classification module 30 can also determine where in the object store module 32 the captured object should be stored. With reference to FIG. 5 , in one embodiment, the objects are stored in a content store 44 memory block. Within the content store 44 are files 46 divided up by content type. Thus, for example, if the object classification module determines that an object is a Word document that should be stored, it can store it in the file 46 reserved for Word documents. In one embodiment, the object store module 32 is integrally included in the capture system 22 . In other embodiments, the object store module can be external—entirely or in part—using, for example, some network storage technique such as network attached storage (NAS) and storage area network (SAN).
In one embodiment, the content store is a canonical storage location, simply a place to deposit the captured objects. The indexing of the objects stored in the content store 44 is accomplished using a tag database 42 . In one embodiment, the tag database 42 is a database data structure in which each record is a “tag” that indexes an object in the content store 44 , and contains relevant information about the stored object. An example of a tag record in the tag database 42 that indexes an object stored in the content store 44 is set forth in Table 1:
TABLE 1
Field Name
Definition
MAC Address
Ethernet controller MAC address unique to
each capture system
Source IP
Source Ethernet IP Address of object
Destination IP
Destination Ethernet IP Address of object
Source Port
Source TCP/IP Port number of object
Destination Port
Destination TCP/IP Port number of the object
Protocol
IP Protocol that carried the object
Instance
Canonical count identifying object within a protocol
capable of carrying multiple data within a single
TCP/IP connection
Content
Content type of the object
Encoding
Encoding used by the protocol carrying object
Size
Size of object
Timestamp
Time that the object was captured
Owner
User requesting the capture of object (rule author)
Configuration
Capture rule directing the capture of object
Signature
Hash signature of object
Tag Signature
Hash signature of all preceding tag fields
There are various other possible tag fields, and some embodiments can omit numerous tag fields listed in Table 1. In other embodiments, the tag database 42 need not be implemented as a database; other data structures can be used. The mapping of tags to objects can, in one embodiment, be obtained by using unique combinations of tag fields to construct an object's name. For example, one such possible combination is an ordered list of the Source IP, Destination IP, Source Port, Destination Port, Instance and Timestamp. Many other such combinations including both shorter and longer names are possible. In another embodiment, the tag can contain a pointer to the storage location where the indexed object is stored.
Referring again to FIG. 3 , in one embodiment, the objects and tags stored in the object store module 32 can be interactively queried by a user via the user interface 34 . In one embodiment the user interface can interact with a web server (not shown) to provide the user with Web-based access to the capture system 22 . The objects in the content store module 32 can thus be searched for specific textual or graphical content using exact matches, patterns, keywords, and various other advanced attributes.
For example, the user interface 34 can provide a query-authoring tool (not shown) to enable users to create complex searches of the object store module 32 . These search queries can be provided to a data mining engine (not shown) that parses the queries, scans the tag database 42 , and retrieves the found object from the content store 44 . Then, these objects that matched the specific search criteria in the user-authored query can be counted and displayed to the user by the user interface 34 .
Searches can also be scheduled to occur at specific times or at regular intervals, that is, the user interface 34 can provide access to a scheduler (not shown) that can periodically execute specific queries. Reports containing the results of these searches can be made available to the user at a later time, mailed to the administrator electronically, or used to generate an alarm in the form of an e-mail message, page, syslog or other notification format.
In several embodiments, the capture system 22 has been described above as a stand-alone device. However, the capture system of the present invention can be implemented on any appliance capable of capturing and analyzing data from a network. For example, the capture system 22 described above could be implemented on one or more of the servers 14 or clients 16 shown in FIG. 1 . The capture system 22 can interface with the network 10 in any number of ways, including wirelessly.
In one embodiment, the capture system 22 is an appliance constructed using commonly available computing equipment and storage systems capable of supporting the software requirements. In one embodiment, illustrated by FIG. 6 , the hardware consists of a capture entity 46 , a processing complex 48 made up of one or more processors, a memory complex 50 made up of one or more memory elements such as RAM and ROM, and storage complex 52 , such as a set of one or more hard drives or other digital or analog storage means. In another embodiment, the storage complex 52 is external to the capture system 22 , as explained above. In one embodiment, the memory complex stored software consisting of an operating system for the capture system device 22 , a capture program, and classification program, a database, a filestore, an analysis engine and a graphical user interface.
Document Registration
The capture system 22 described above can also be used to implement a document registration scheme. In one embodiment, the a user can register a document with the system 22 , which can then alert the user if all or part of the content in the registered document is leaving the network. Thus, one embodiment of the present invention aims to prevent un-authorized documents of various formats (e.g., Microsoft Word, Excel, PowerPoint, source code of any kind, text) from leaving an enterprise. There are great benefits to any enterprise that can keep its intellectual property, or other critical, confidential, or otherwise private and proprietary content from being mishandled.
In one embodiment of the present invention, sensitive documents are registered with the capture system 22 , although data registration can be implemented using a separate device in other embodiments. One embodiment of implementing registration capability in the capture system 22 is now described with reference to FIG. 7 . For descriptive purposes, the capture system 22 is renamed the capture/registration system 22 in FIG. 7 , and is also sometimes referred to as the registration system 22 in the description herein. The capture/registration system 22 has components similar or identical to the capture system 22 shown in FIG. 3 , including the network interface module 24 , the object store module 32 , the user interface 34 , and the packet capture 26 , object assembly 28 , and object classification 30 modules, which are grouped together as object capture modules 31 in FIG. 7 .
In one embodiment, the capture/registration system 22 also includes a registration module 54 interacting with a signature database 56 to facilitate a registration scheme. In one embodiment, the user can register a document via the user interface 34 . There are numerous ways to register documents. For example, a document can be electrically mailed (e-mailed), or uploaded to the registration system 22 . The registration system 22 can also periodically scan a file server (registration server) for documents to be registered. The registration process can be integrated with the enterprise's document management systems. Document registration can also be automated and transparent based on registration rules, such as “register all documents,” or “register all documents by specific author or IP address,” and so on.
After being received, in one embodiment, a document to be registered is passed to the registration module 54 . The registration module 54 calculates a signature of the document, or a set of signatures. The set of signatures associated with the document can be calculated in various ways. For example, the signatures can be made up of hashes over various portions of the document, such as selected or all pages, paragraphs, tables and sentences. Other possible signatures include, but are not limited to, hashes over embedded content, indices, headers or footers, formatting information or font utilization. The signatures can also include computations and meta-data other than hash digests, such as Word Relative Frequency Methods (RFM)—Statistical, Karp-Rabin Greedy-String-Tiling-Transposition, vector space models, and diagrammatic structure analysis.
The set of signatures is then stored in the signature database 56 . The signature database 56 need not be implemented as a database; the signatures can be maintained using any appropriate data structure. In one embodiment, the signature database 56 is part of the storage complex 52 in FIG. 6 .
In one embodiment, the registered document is also stored as an object in the object store module 32 . In one embodiment, the document is only stored in the content store 44 with no associated tag, since many tag fields do not apply to registered documents. In one embodiment, one file of files 46 is a “Registered Documents” file.
In one embodiment, the document received from the user is now registered. As set forth above, in one embodiment, the object capture modules 31 continue to extract objects leaving the network, and store various objects based on capture rules. In one embodiment, all extracted objects—whether subject to a capture rule or not—are also passed to the registration module for a determination whether each object is, or includes part of, a registered document.
In one embodiment, the registration module 54 calculates the set of signatures of an object received from the object capture modules 31 in the same manner as of a document received from the user interface 34 to be registered. This set of signatures is then compared against all signatures in the signature database 56 . In other embodiment, parts of the signature database can be excluded from this search to save time.
In one embodiment, an unauthorized transmission is detected if any one or more signatures in the set of signatures of an extracted object matches one or more signature in the signature database 56 associated with a registered document. Other detection tolerances can be configured for different embodiment, e.g., at least two signatures must match. Also, special rules can be implemented that make the transmission authorized, e.g., if the source address is authorized to transmit any documents off the network.
One embodiment of the registration module 54 is now described with reference to FIG. 8 . As discussed above, a document to be registered 68 arrives via the user interface 34 . The registration engine 58 generates signatures 60 for the document 68 and forwards the document 68 to the content store 44 and the signatures 60 to the signature database 54 . The signatures 60 are associated with the document, e.g., by including a pointer to the document 68 , or to some attribute from which the document 68 can be identified.
A captured object 70 arrives via the object capture modules 31 . The registration engine calculates the signatures 62 of the captured object, and forwards them to the search engine 64 . The search engine 64 queries the signature database 54 to compare the signatures 62 to the signatures stored in the signature database 54 . Assuming for the purposes of illustration, that the captured object 70 is a Word document that contains a pasted paragraph from registered PowerPoint document 68 , at least one signature of signatures 62 will match a signature of signatures 60 . Such an event can be referred to as the detection of an unauthorized transfer, a registered content transfer, or other similarly descriptive terms.
In one embodiment, when a registered content transfer is detected, the transmission can be halted with or without warning to the sender. In one embodiment, in the event of a detected registered content transfer, the search engine 64 activates the notification module 66 , which sends an alert 72 to the user via the user interface 34 . In one embodiment, the notification module 66 sends different alerts—including different user options—based on the user preference associated with the registration, and the capabilities of the registration system 22 .
In one embodiment, the alert 72 can simply indicate that the registered content, i.e., the captured object 70 , has been transferred off the network. In addition, the alert 72 can provide information regarding the transfer, such as source IP, destination IP, any other information contained in the tag of the captured object, or some other derived information, such as the name of the person who transferred the document off the network. The alert 72 can be provided to one or more users via e-mail, instant message (IM), page, or any other notification method. In one embodiment, the alert 72 is only sent to the entity or user who requested registration of the document 68 .
In another embodiment, the delivery of the captured object 70 is halted—the transfer is not completed—unless the user who registered the document 68 consents. In such an embodiment, the alert 72 can contain all information described above, and in addition, contain a selection mechanism, such as one or two buttons—to allow the user to indicate whether the transfer of the captured object 70 may be completed. If the user elects to allow the transfer, for example because he is aware that someone is emailing a part of a registered document 68 (e.g., a boss asking his secretary to send an email), the transfer is executed and the object 70 is allowed to leave the network.
If the user disallows the transfer, the captured object 70 is not allowed off the network, and delivery is permanently halted. In one embodiment, halting delivery can be accomplished by implementing an intercept technique by having the registration system 22 proxy the connection between the network and the outside. In other embodiments, delivery can be halted using a black hole technique—discarding the packets without notice if the transfer is disallowed—or a poison technique—inserting additional packets onto the network to cause the sender's connection to fail.
FIG. 9 provides a flow chart to further illustrate object capture/intercept processing according to one embodiment of the present invention. All blocks of FIG. 9 have already been discussed herein. The example object capture processing shown in FIG. 9 assumes that various documents have already been registered with the registration system 22 . The process shown in FIG. 9 can be repeated for all objects captured by the system 22 .
Thus, a capture system and a document/content registration system have been described. In the forgoing description, various specific values were given names, such as “objects,” and various specific modules, such as the “registration module” and “signature database” have been described. However, these names are merely to describe and illustrate various aspects of the present invention, and in no way limit the scope of the present invention. Furthermore, various modules, such as the search engine 64 and the notification module 66 in FIG. 8 , can be implemented as software or hardware modules, or without dividing their functionalities into modules at all. The present invention is not limited to any modular architecture either in software or in hardware, whether described above or not.
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A document accessible over a network can be registered. A registered document, and the content contained therein, cannot be transmitted undetected over and off of the network. In one embodiment, the invention includes maintaining a plurality of stored signatures, each signature being associated with one of a plurality of registered documents, intercepting an object being transmitted over a network, calculating a set of signatures associated with the intercepted object, and comparing the set of signatures with the plurality of stored signatures. In one embodiment, the invention can further include detecting registered content from the registered document being contained in the intercepted object, if the comparison results in a match of at least one of the signatures in the set of signatures with one or more of the plurality of stored signatures.
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TECHNICAL FIELD OF THE INVENTION
This invention relates generally to optical beam guidance systems, and more particularly, to a method and system for automatically correcting boresight errors in a laser beam guidance system.
BACKGROUND OF THE INVENTION
Laser beam guidance systems are used to align a laser beam with an optical boresight, in order to direct the beam to a selected target. Typically, a designated target is viewed through the boresight, and the laser beam is directed to illuminate the target. The reflection of the illumination may be used to guide a weapon to the target. In such a guidance system, the axis of the laser beam must be precisely aligned with the boresight axis, otherwise target designation errors will occur that significantly degrade the accuracy of the weapons delivery system.
One approach to aligning a laser beam with a boresight is described in U.S. Pat. No. 4,385,834, which issued on May 31, 1983 to Richard F. Maxwell, Jr. Maxwell describes a laser beam boresight system that aligns a laser beam's axis with an imaging sensor's viewing axis. The imaging sensor's viewing axis is used as one reference axis. A second laser beam's axis, which is fixed with respect to the first laser beam's axis, is aligned with an electromagnetic source beam axis. A light emitting diode is used as the electromagnetic source. The electromagnetic source beam axis is used as a second reference axis. The first reference axis is fixed with respect to the second reference axis. The angular displacement between the second laser beam's axis and the two, reference axes is detected, and error signals are generated by the detector which are proportional to the angular displacement. The error signals are used to correct the angular displacement, in order to align the second laser beam with the reference beam axes. If the system is properly aligned, the image of the reference source beam in the sensor's display will represent the target at which the first laser beam is directed. However, Maxwell's use of multiple laser beams increases the technical complexity and cost of such a system. An increase in the complexity of such a system is accompanied by a decrease in system accuracy. Furthermore, since the detection of the angular displacement between the second laser beam's axis and the two, reference axes is accomplished at a significant distance from the laser source, a significant amount of noise is generated at the detection stage, which introduces additional errors that further decrease the accuracy of the system. Accordingly, a need exists in the laser beam guidance manufacturing industry for a less complex but more accurate, automatic boresight alignment system.
SUMMARY OF THE INVENTION
In accordance with the present invention, a method and system is provided for automatically maintaining the position of a laser beam relative to a boresight axis by using a highly sensitive and selective beam position detector that is optimally located for noise reduction, and compensating for angular errors by displacing the laser beam directly and thereby minimizing tracking errors.
An important technical advantage of the present invention is that accurate laser beam positioning may be accomplished with relatively minimal complexity and cost. Another important technical advantage of the invention is that noise generated during the detection phase may be minimized, which significantly increases the overall accuracy and response time of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIGS. 1(a)-(b) illustrate a block diagram of a system for automatically correcting boresight errors in a laser guidance system and a beam splitter assembly in accordance with a preferred embodiment of the present invention.
FIG. 2 illustrates an electrical schematic circuit diagram of the detector and transimpedance amplifier stages shown in FIG. 1.
FIG. 3 illustrates an electrical schematic circuit diagram of the pulse amplifier, pulse summer and amplifier, and sample and hold stages shown in FIG. 1.
FIG. 4 illustrates an electrical schematic circuit diagram of the DC summer and comparator stages shown in FIG. 1.
FIG. 5 illustrates an electrical schematic circuit diagram of the motor logic and trigger generator stages shown in FIG. 1.
FIG. 6 illustrates an electrical schematic circuit diagram of the motor drive stage shown in FIG. 1.
FIG. 7 illustrates representative voltages from the timing and logic circuitry of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention and its advantages are best understood by referring to FIGS. 1-7 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIG. 1(a) illustrates a block diagram of a system for automatically correcting boresight errors in a laser guidance system in accordance with a preferred embodiment of the present invention. Pertinent details of the beam splitter assembly in FIG. 1(a) are shown in FIG. 1(b). Referring to FIGS. 1(a) and 1(b), synchronization pulse generator 102 provides the timing pulse for laser source 104, which generates laser beam l1 having a pulse width of 17 nanoseconds and operating at a repetition rate of about 20 Hz. Although the preferred embodiment is directed to a laser beam guidance system, the invention is not intended to be so limited, and may include guidance of any beam operating in the optical frequency band. Beam l1 passes through optical wedges 106 and may be angularly displaced by the positioning of the optical wedges. The displaced beam is designated as l2. Beam guidance is controlled by counter-rotating the two pairs of optical wedges 106, whereby one pair of wedges operates to position the beam in the vertical plane and the other pair of wedges positions the beam in the horizontal plane. Each wedge is mounted in the center of a Delrin gear (not explicitly shown). Each gear is driven by a pinion mounted on the shaft of a stepper motor located in stepper motor assembly 110. In the preferred embodiment, the pinion to gear ratio is 5:1, which provides increased torque to position the wedge along with greater incremental control and resolution (i.e., more incremental positioning steps). A first portion of beam l2 (≈99% of the light energy) passes through optical prism 109 and is directed toward the designated target (not explicitly shown) as beam l4, while a second portion of beam l2 (≈1% of the light energy) is reflected towards beam splitter 108 as beam l5. To form a reference reticle image, light source 111, which may be any appropriate source of light energy, generates a beam of light that passes through reticle 111a, beam splitter 108 and optical prism 109, and is directed to the eyepiece as beam l6. A design objective is to structure a projected reticle and quad detector, which have a common optical axis and apparent focal point for tracking the laser spot relative to the aim mark. Quad detector 112 and reticle 111a are protected from raw designator power by optical filter 108a on a surface of beam splitter 108. Consequently, a viewer at the eyepiece of the reticle may view the designated target. A direct path between reticle light source 111 and the reticle eyepiece is designated as the boresight axis. Additionally, a portion of beam l5 is passed through beam splitter 108 and reflected toward quad detector 112. Essentially, the invention functions to maintain the coaxial relationship between the boresight axis and the axis of the reflected laser beam, which may then be coincident with the axis of beam l5. Therefore, in accordance with the teachings of the present invention, upon detecting an angular displacement or error of beam l3 at quad detector 112 (i.e., a misalignment of the laser beam's axis with the boresight axis), system 100 automatically compensates for the error by operating optical wedges 106 to adjust the angular displacement of beam l2 and thereby minimize the displacement at the detector, which functions to adjust the angular displacement of beam l5 accordingly to realign the laser beam's axis coincidentally with the boresight axis.
FIG. 2 shows a schematic circuit diagram of the quad detector and transimpedance amplifier stages shown in FIGS. 1(a) and 1(b). Quad detector 112 may include four, identical silicon semiconductor photodetectors A-D. For the purposes of this discussion, only detector A will be described in detail, since it's structure and operation are identical to those of each of the other detectors B-D in assembly 112. For example, detector A includes light-sensitive diode D1 and capacitor C1. The light energy from beam l3 impinges on diode D1, and a charge is developed over time in capacitor C1. The resulting signal from detector 112A is coupled through input connection 6 to a signal input of transimpedance amplifier U1. Each detector 112A-D has a photosensitive area of 1.5 mm×1.5 mm per cell. The gap between cells may be 10 microns, which is much smaller than the 50 micron spot formed by laser beam l3. Consequently, the minimum tracking error produced by each detector 112A-D will be significantly low. To minimize front-end noise pick up, detectors 112A-D are mounted directly to an electrical connector to form quad detector assembly 112, which is mated to an input connector on current-to-voltage converter stage 114.
Current-to-voltage converter stage 114 includes four, identical transimpedance amplifiers U1-U4 and their associated circuitry. Each of amplifiers U1-U4 is a high speed, wide-band, current feedback operational amplifier having a low output impedance and capable of driving a 50 ohm load. The outputs of amplifiers U1-U4 are coupled by 50 ohm coax cables to respective inputs of pulse amplifier stage 116 and pulse summer and amplifier stage 128. By mounting each transimpedance amplifier in close proximity to its respective detector, transimpedance amplifier stage 114 operates as a preamplifier assembly to amplify the low level input signals from detectors 112A-D while minimizing front end noise pick up.
FIG. 3 illustrates an electrical schematic circuit diagram of the pulse amplifier, pulse summer and amplifier, and sample and hold stages shown in FIG. 1(a). Generally, the circuitry depicted in FIG. 3 contains four, identical signal processing channels and a trigger pulse generator, which develops the basic trigger pulse for timing the digital circuits in the system. Since the structure and operation of these four signal processing channels are identical, only "channel A" will be described in detail, it being understood that the description applies equally to each of the four channels. Specifically, the input signal "Quad A" from transimpedance amplifier U1 is developed across potentiometer R85, which may be adjusted in conjunction with corresponding potentiometers R87, R89 and R91 to balance the four channels. The input signal developed across R85 is coupled to the negative signal input of amplifier U5, and also to the negative signal input of operational amplifier U7. The signal at the output of amplifier U5 is inverted and coupled to the source of enhancement mode FET Q1. The output signal from amplifier U7 is coupled to the gate of FET Q1 and also to laser trigger output connection 13. The output signal from amplifier U7 is used as the trigger pulse for timing the operations of the digital circuits in the system and also providing a gate pulse for controlling the timing of the conduction of enhancement mode FET Q1. The output signal at the drain of FET Q1 is developed across holding capacitor C15 and coupled to the positive signal input of output source follower U10A, which operates as an output buffer stage for the preamplifier assembly. The output connection of source follower U10A is coupled to the channel A output connection of transimpedance amplifier stage 114.
The gate pulse for controlling the conduction of FETs Q1-Q4 is developed by summing the outputs of amplifiers U5-U9 across resistors R29-R34 with a DC offset voltage developed across potentiometer R93. The resulting signal at the output of amplifier U7 is clipped by diodes D1 and D2 and their associated circuits to provide a positive-going pulse having a slightly smaller pulse width than the 17 nanosecond pulse width of the signal from laser beam l3.
The primary purpose of the signal inverter, enhancement mode FET, holding capacitor, and output source follower circuits in each of the four processing channels is to provide sample and hold circuits for each channel. Since the laser signal derived from beam l3 has a pulse width of only 17 nanoseconds, it is preferable to sample the input signal and store it for a processing period of about 42.5 milliseconds (i.e., for a period just less than the 50 milliseconds between laser pulses). Consequently, the signal coupled to the gates of FET's Q1-Q4 causes the FETs to turn on in synchronization with each laser pulse in beam l3. This DC level at the drains of the FETs is held by capacitor C15 for the aforementioned 42.5 millisecond processing period. In the preferred embodiment, the time needed to process the detected laser signals and provide corresponding drive signals to position the optical wedges may be within the 42.5 millisecond processing period. The output signals A-D from the four channels shown in FIG. 3 are DC voltages that represent the magnitudes of the light beams sensed by each of the respective photosensitive detectors.
FIG. 4 illustrates an electrical schematic circuit diagram of the DC summer and comparator stages shown in FIG. 1(a). Generally, the four DC voltage signals A-D from the outputs of source followers U10A-D are decoded into x and y positional information (Cartesian Coordinate System) using sum and difference amplifiers. This positional information is then converted into digital signals using a comparator circuit. Specifically, DC voltage signal A from the output of amplifier U10A is coupled to the negative signal inputs of amplifiers U25A and U25C, signal B is coupled to the positive signal input of amplifier U25A and the negative signal input of amplifier U25C, signal C is coupled to the positive signal inputs of amplifiers U25A and U25C, and signal D is coupled to the negative signal input of amplifier U25A and the positive signal input of amplifier U25C. The output signal from amplifier U25A is coupled to the negative signal input of amplifier U25D and the positive signal input of amplifier U2B. The output signal from amplifier U25C is coupled to the negative signal input of amplifier U25B and the positive signal input of amplifier U2D. The output of amplifier U25D is coupled to the negative input of comparator U1A, and the positive inputs of comparators U1B and U2A. The output of amplifier U25B is coupled to the negative input of comparator U1C, and the positive inputs of comparators U1D and U2C. The outputs of comparators U1A and U1B are coupled to respective inputs of AND gate U3A, while the outputs of comparators U2A and U2B are coupled to respective inputs of OR gate U4A.
Similarly, the outputs of comparators U1C and U1D are coupled to respective inputs of AND gate U3B, while the outputs of comparators U2C and U2D are coupled to respective inputs of OR gate U4B. The six positional signals output from comparator 122 are coupled to motor logic circuit 124.
FIG. 5 illustrates an electrical schematic circuit diagram of the motor logic and trigger generator stages shown in FIG. 1(a). Generally, the trigger pulse generated by the sample and hold circuits is used to activate timing circuits in motor logic stage 124. Timing the drive operations in this manner ensures that the motor drive positioning signals will be applied to the optical wedge drive motors only after the laser has fired, thus synchronizing, and minimizing errors in, the movement of the wedges. Specifically, to activate the timing circuits, the laser trigger pulse generated at the output of amplifier U7 in FIG. 3, is coupled to the clock input of flip flop U6. The Q output of flip flop U6 is coupled to the B input of flip flop U7. The negated Q output of flip flop U7 is coupled to the negated reset inputs of flip flops U14A, U14B and U15A. The Q output of flip flop U14B provides the aforementioned 42.5 millisecond sample gate pulse, which is used to clock the logic circuits used for controlling the drive motors. The resulting sample gate pulse is also coupled to the negative signal input of amplifier U7 in FIG. 3. This sampling gate, which has an inherent delay time greater than 20 nanoseconds relative to the trigger pulse, is used to blank trigger generator stage 130 for a period of 42.5 milliseconds. This blanking operation thus inhibits any stray noise from generating false triggers.
The X REV/FWD positioning signal from comparator 122 is coupled to one input of XOR gate U16A, U16B, U16C, and the D input of flip flop U18A. The X FAST signal is coupled to one input of AND gates U13A and U13B, and the Y FAST signal is coupled to one input of AND gates U13C and U13D. The Y REV/FWD signal is coupled to circuitry that is virtually identical in structure and operation to the circuitry used to process the X REV/FWD signal.
The X boresight signal is coupled to one input of OR gate U4C, and the Y boresight signal is coupled to an input of OR gate U4D. The negated Q output of flip flop U14A (X MOTOR GATE) is coupled to the second input of OR gate U4C, and the negated Q output of flip flop U15A (Y MOTOR GATE) is coupled to the second input of OR gate U4D. The Q output of flip flop U17A is coupled to the second input of XOR gate U16B and also provides the output signal X PHASE A. The negated Q output of flip flop U17B is coupled to the second input of XOR gate U16A and also provides the output signal X PHASE B.
The Y positional logic is provided in a similar configuration, whereby the Q output of flip flop U17C is coupled to the second input of XOR gate U19B, and also provides the Y PHASE A output signal. The negated Q output of flip flop U17D is coupled to the second input of XOR gate U19A, and also provides the output signal Y PHASE B. The output of OR gate U4C provides the X MOTOR ENABLE output signal,and the output of OR gate U4D provides the output signal Y MOTOR ENABLE.
FIG. 6 illustrates an electrical schematic circuit diagram of the motor drive stage shown in FIG. 1(a). Essentially, one UC1717A stepper motor drive integrated circuit, manufactured by Unitrode, is provided for two of stepper motors 110 in FIG. 1(a). In the preferred embodiment, each integrated circuit drive chip is rated at 1A. Each chip provides drive current for two drive motors. For example, chip U21 may provide drive current to position one of a pair of wedges in one x direction, while counterpositioning the second wedge of the pair in the opposing x direction. In that case, chip U22 may drive the same pair of wedges, but each wedge is driven in an opposite direction relative to the other. As discussed above, in order to guide the laser beam l2, the wedges in each pair are counter-rotated with respect to the other.
Specifically, the X PHASE A signal may be coupled to the phase input of stepper motor IC U21, and the X PHASE B signal may be coupled to the phase input of IC U22. The X MOTOR ENABLE signal may be coupled to the current control inputs of IC's U21 and U22. Similarly, for the Y positioning signals, the Y PHASE A signal may be coupled to the phase input of IC U23, and the Y PHASE B signal may be coupled to the phase input of IC 24. The Y MOTOR ENABLE signal may be coupled to the current control inputs of IC's U23 and U24. The current signals to drive stepper motors 110 (FIG. 1(a)) may be provided at the A and B outputs of respective IC's U21-U24.
In operation, when laser source 104 is fired, beam l1 passes through the two pairs of optical wedges in assembly 106 to form deflected beam l2. The amount that beam l2 may be angularly offset from the radial axis of beam l1 is determined by the positions of wedges 106. One pair of wedges may be operable to position the laser beam in a horizontal (x) direction, and the other pair may position the beam in a vertical (y) direction. The light energy in beam l2 is split into at least two parts (beams l4 and l5) by optical prism 109. Approximately 99% of the light energy from beam 2 is passed through the prism as beam l4, while the other approximately 1% of the energy is reflected as beam l5. Approximately 2% of the light energy in beam l5 is reflected in beam splitter 108 and passed through as beam l3. Consequently, depending on the positions of wedges 106, beam l3 will impinge on quad detector 112 at a particular location.
Quad detector 112 generates current signals in each of channels A-D, which are proportional to the amount of light energy detected in each quadrant. For illustrative purposes only, FIG. 2 shows a portion of beam l3 being detected by photodetector 112A, while in reality, some portion of the light energy from beam l3 may be detected by more than one photodetector 112A-D. For example, if beam l3 were to be perfectly centered in the quad detector, then 1/4 of the light energy (theoretically) would be sensed by each detector 112A-D, and the magnitudes of the current signals generated in all channels A-D would be equal. If, however, the beam spot were to be perfectly centered on the axis between quadrants A and B, but far removed from the axes with quadrants C and D, then (theoretically) 1/2 of the light energy would be sensed by each of detectors A and B, the current signals generated in channels A and B would be equal, and the current signals generated in channels C and D would be zero. The current signals from detectors 112A-D are amplified and converted to voltage signals in respective transimpedance amplifiers U1-U4, and coupled to the respective inputs of pulse amplifier stage 116.
Prior to operating system 100 in accordance with the invention, a preferable procedure used is to align the laser beam mechanically to coincide with the boresight axis. First, using any conventional, mechanical optical alignment technique, the boresight optics are aligned with the target area to be viewed. Then, the laser beam is mechanically aligned with the boresight so that the target area to be viewed is also illuminated accordingly by the laser beam. Once the laser beam is mechanically aligned and oriented properly with the boresight axis, system 100 functions automatically to maintain that alignment in accordance with the present invention.
Further orienting the system, optical wedges 106 are initially preset to allow laser beam 1 to pass through undisturbed. Then, subsequent to the initial alignment of the laser beam to the boresight axis, but still prior to providing automatic boresight alignment, the undisturbed beam is physically aligned (preferably by moving prism 109 and beam splitter 108) so that beam l3 impinges directly on the center of quad detector 112 once the boresight is physically aligned with the laser beam, which produces equal signals (i.e., no angular error) in channels A-D.
Subsequent to the above-described initial, alignment of the laser beam with the boresight axis, system 100 then functions automatically to maintain the position of the laser beam. Specifically, in accordance with a preferred embodiment of the invention, each time laser 104 (FIG. 1(a)) is fired, a relatively small portion of the laser beam is directed, as beam l3, to quad detector 112. The quad detector generates current signals in detectors 112A-D, which are proportional to the magnitude of the laser energy detected in each respective quadrant A-D. The current signals from detectors 112A-D are converted to voltage signals by respective wide-bandwidth operational amplifiers U1-U4 (FIG. 2), which are configured to operate in a transimpedance mode. As described above, these high impedance amplifiers U1-U4 are mounted in close proximity to quad detector 112, in order to minimize front end noise pickup and associated system errors. The voltage signals output from amplifiers U1-U4 are amplified in pulse amplifier stage 116 and coupled to sample and hold stage 118. Since the laser's pulse width is only 17 nanoseconds, the sample and hold stage stores each pulse and provides a gate of about 42.5 milliseconds for each channel A-D to process its respective signal. Importantly, the motor logic circuitry develops the sampling gate, which synchronizes the signal processing and error correction circuits in each channel A-D, directly from the laser pulse. Consequently, system 100 avoids the conventional technique of generating a special synchronization pulse for sampling, along with avoiding associated circuit complexity and attendant costs.
Referring to FIG. 3, potentiometers R85, R87, R89 and R91 may be adjusted to balance the gains of respective channels A-D. In a preferred embodiment, the gain of each channel A-D may be set, for example, to provide a maximum of 3 volts peak at the source of each FET Q1-Q4, when all of the laser energy is directed at, and detected in, that respective quadrant A-D of quad detector 112. The drive signal used to gate FETs Q1-Q4 is developed in pulse summer and amplifier stage 128, by summing the output signals from each transimpedance amplifier and a DC offset compensation voltage developed across potentiometer R93. The resulting summed signal is amplified at U7 and clipped by diodes D1 and D2 to provide a positive-going pulse of duration just under the 17 nanosecond pulse width of the laser. The gain of amplifier U7 is set so that the positive-going pulse has a peak magnitude of 5 volts. Preferably, the magnitude of the positive-going pulse applied to the gates of the sampling and hold FETs Q1-Q4 is thus maintained at that level independently of the signal levels developed in each channel A-D (i.e., independent of the laser beam's position). During each 42.5 millisecond gating or processing period between laser pulses, the sum and difference of the signals developed in channels A-D are output from amplifiers U25A-D and compared at comparator amplifiers U1A-D and U2A-D (FIG. 4). The resulting analog signals (their relative magnitudes representing the position of the laser beam with respect to the detector's quadrants) are then converted to a digital format using logic gates U3A-C and U4A-B.
Generally, the positional information from the comparator amplifiers indicates whether the laser beam spot is pointed above or below the X (horizontal) axis of quad detector 112, to the right or left of the Y (vertical) axis, touching either axis, very close to either axis, or directly at the center (i.e., at boresight) of the quad detector. This positional information may be derived from a comparison of the relative amount of light energy detected in each quadrant of detector 112, which is further represented by the relative magnitudes of the signals being processed in channels A-D. If the beam spot is not "touching" any axis, then an appropriate X FAST and/or Y FAST signal may be output from comparator stage 122, to cause the respective stepper motors 110 to step at their fastest rate. If, however, the beam spot is "touching" an axis, the appropriate stepper motors 110 which drive in that horizontal or vertical direction are caused to step at the slowest rate (i.e., no X FAST or Y FAST signal is output from comparator stage 122).
If the beam spot "crosses" an axis of quad detector 112, the respective comparators for that direction "fire" and a "reverse direction" signal is output from the comparator to the stepper motors for that direction. For example, if the beam spot crosses the X axis, then comparator U1B "fires" and an X REV/FWD signal is output to motor logic stage 124, which operates to reverse the drive direction of the horizontal stepping motors. Similarly, comparator U1D would fire to reverse the direction of the Y stepper motors, if the beam spot were to cross the Y axis. Preferably, using the above-described technique, system 100 compensates for any positional error by returning the beam to the origin of both axes (i.e., reacquiring boresight). Some hysteresis is designed into the comparator circuitry so that system "noise" will not trigger movement of the stepper motors.
If the beam spot is pointed directly at an axis (e.g., stopped on the X axis), then a corresponding pair of comparators would fire (e.g., both U1A and U1B would fire indicating a signal balance in the X direction) and the appropriate BORE signal (X BORE in the example) would be output to the motor logic stage. If the beam spot is pointing directly at boresight, then the corresponding pairs of X and Y comparators U1A-B and U1C-D would all fire indicating a signal balance in the X and Y directions (i.e., the signals in channels A-D are "equal"). Consequently, the X and Y BORE logic signals would be applied to AND gate U3C, which would, in turn, output a BORESIGHT OK signal to indicate that the angular displacement error is zero, and the laser beam has been realigned with the boresight axis.
Referring to FIG. 4, motor logic circuity 124 uses the positional information derived from the comparator circuits to generate drive commands for the stepper motors. The motor logic circuitry operates to allow the stepper motors to step at a rate of at least one of 8, 4, 2 or 1 increments per laser pulse, depending on the relative position of the beam spot. For example, assuming that the beam spot is positioned in the left half of the quadrant, closer to the Y axis than the X axis, and only detector 112A is outputting a signal. Motor logic circuitry 124 would then command the X and Y stepper motors to move at a rate of 8 increments per laser pulse. In response, the beam spot would be adjusted by the optical wedges to approach boresight (the intersection of the X and Y axes) at a 45° angle, thereby traversing the B quadrant. Then, during the next 42.5 millisecond processing cycle, the X motors would be directed by the motor logic circuitry to reverse and only move 4 increments. The Y motors would be directed to continue to move at a rate of 8 increments per pulse.
At the end of the second processing cycle, the beam spot should be "touching" the Y axis and the X motor rate would then be changed to one increment per pulse. Soon, the beam spot would be positioned very close to the Y axis and the X motors would then be disabled. The Y motors would continue to step the beam spot down the Y axis at 8 increments per pulse, until the X axis is crossed. At this point, the Y stepper motors would be reversed and the stepping rate accordingly reduced. The Y motors' movement would then continue at the slowest rate until boresight is reached. At boresight, the Y motors are then disabled.
An application of the present system for automatically correcting boresight errors in a laser beam guidance system is in laser rangefinder/designator systems. In accordance with the teachings of the present invention, system 100 operates to detect the position of the laser beam after the laser has fired and automatically correct for boresight error. An incremental correction is made during the time period between two laser pulses. When the laser beam of the present system is very close to boresight, the incremental correction needed is less than the minimum resolution requirements of the system. The correction is made by stepper motors (described below), which drive the two sets of optical wedges (described below) that are located in the optical system of the output laser beam. Thus, synchronization of the system is started by a laser pulse, and the incremental correction performed by the stepper motors is completed before the start of the next laser pulse. This operation may be illustrated by the system timing waveforms illustrated in FIG. 7 and described in detail below.
Referring to FIG. 5, when system 100 is first turned on, a plus 5 volts is applied to gate generator U8. Gate generator U8 generates a plurality of negative gates (MCL or "master clear") to clear the flip flops in FIG. 5 and ensure that the system is initialized to a known state. Motor logic circuitry 124 (and system 100) is now waiting for the first laser pulse. Note that none of the timing waveforms shown on FIG. 7 are generated before the first trigger pulse is applied.
The laser trigger pulse developed at the output of the pulse summer and amplifier stage (J19, pin 13 in FIG. 3) is used to synchronize the error correction operations of system 100. Referring again to FIG. 5, the laser trigger pulse is used to clock flip-flop U6, which in turn, clocks flip-flop U7, which provides a 7 μsec negative preset gate at node 502. The preset gate is applied to the preset input of flip-flop U14B which starts a 42.5 millisecond positive-going sample gate at the Q output. The preset gate is also applied to the preset inputs of flip-flops U14A and U15A to start the X and Y motor gates, which are provided at the respective negated Q outputs, and further to the clear input of binary counter U10. An oscillator comprised of logic gates U5A-D is turned on by the leading edge of the sample gate. The output of the oscillator (connection 11 of U5D) is applied to binary counter U10 and each of the logic circuits that generate the phase signals (X PHASE A and B, Y PHASE A and B) to control the stepper motor ICs and, consequently, the stepper motors (discussed below). The duration of the sample gate is such that the oscillator circuitry is cut off when binary counter U10 reaches a count of 17. The negative-going lagging edge of the sampling gate is then used to reset the motor logic circuitry in preparation for the next laser pulse and 42.5 millisecond processing cycle. The outputs of binary counter U10 are coupled to the inputs of respective X and Y multiplexers U11 and U12. The output of each multiplexer U11 and U12 is used to set the respective X and Y logic circuitry, which accordingly selects the width of the X or Y motor gate. The width of the X or Y motor gate determines the number of increments per laser pulse the respective stepper motors will move.
Referring to FIG. 6, stepper motors 110 (FIG. 1(a)) are driven by conventional ICs, each of which has been designed to control and drive the current in one winding of a respective bipolar stepper motor. Each IC chip (U21-24) contains an LS-TTL compatible phase logic input stage and a bridge-configured output stage. Internal to the IC, a voltage divider and three comparators provide control signals for the motor current drive circuits, and two logic inputs to provide digital current level selections. Two sets of optical wedges 106 (i.e., four wedges) are required to position the laser beam, with one motor being used to drive each wedge. Therefore, each IC is used to control one drive motor. A conventional system would typically require 8 motor drive ICs. However, in system 100, since each wedge in a pair is counter-rotated with respect to the other, only one IC is needed to drive one coil in each motor, by properly selecting the drive polarities.
Generally, FIG. 7 illustrates representative voltages from the timing and logic circuitry of the present invention. Referring to FIGS. 6 and 7, the preferred embodiment of the present invention utilizes four steps of a 1.8 degree stepper motor 110, to achieve a resolution of 7.2 degrees. The two phase stepper motors 110 may be stepper motors having the part number 11-SHBD-45AB, which are manufactured by Clifton Precision Division of Litton Industries. Each of the two motor windings are driven by square waves (φ A REV/FWD and φ B REV/FWD) having a period of 10 milliseconds and being 90° out of phase with one another. The leading phase determines a motor's direction of rotation. For the φ A and φ B polarities shown in FIG. 7, a stepper motor would rotate in a reverse direction. During each 10 millisecond period, four logic pairs of phase signals would be generated that would drive a stepper motor four steps of 1.8 degrees per step, or a total of 7.2 degrees. The number of incremental movements of a motor (based on four steps per increment) needed for error correction during the 50 millisecond period between laser pulses, is based on the width of the negative-going motor gate that is applied to the current control input of the appropriate stepper motor drive (UC1717) integrated circuit.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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A method and system is provided for automatically maintaining the position of a laser beam relative to a boresight axis with a highly sensitive and selective beam position detector that is optimally located for noise reduction, and compensating for angular errors by displacing the laser beam directly and thereby minimizing tracking errors.
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BACKGROUND OF THE INVENTION
This invention relates to liquid fertilizers and organophosphorus pesticides. In particular, this invention relates to improved compositions for use in combining emulsifiable organophosphorus pesticide concentrates with aqueous fertilizer solutions for simultaneous field application.
An emulsifiable concentrate is a formulation of a chemical pesticide which is commonly used when the latter is intended for dilution at the field site. The formulation consists of a solution of the pesticide in a water-immiscible or partially water-miscible solvent which forms an emulsion upon dilution with water. Typical solvents include mineral oils, petroleum solvents, chlorinated hydrocarbons, alcohols, glycols, ethers, esters, and ketones. A surface active compound is frequently included in the concentrate to promote emulsification and emulsion stability.
An emulsifiable concentrate has an advantage over solid or semi-solid pesticide formulations in that it is a liquid and can thus be easily mixed with a liquid fertilizer so that the two can be applied to the field at the same time in a common piece of apparatus. Common fertilizer application equipment can be used to distribute a mixture containing both the fertilizer, preferably dissolved in water, and the emulsifiable pesticide concentrate, at prescribed dilution. Both fertilization and insect control are thereby achieved by a single application.
Among the liquid fertilizers in current use are those commonly known as "N-P" and "N-P-K" fertilizers. As their designations indicate, these fertilizers are identified by numbers corresponding to the relative quantities of nitrogen, phosphorus, and potassium salts, expressed as N, P 2 O 5 , and K 2 O, respectively. Unfortunately, certain fertilizers when combined with the pesticide produce an emulsion of low stability. Sometimes, agitation inherent in the application equipment compensates for this. Tractors with spray booms, for example, which are used for broad area application, provide agitation through the pumps which feed the booms and the pump recycle lines which control the spray rate. Additional agitation is provided by paddles in the spray tanks of some tractors. Further agitation is achieved during the transfer of the fertilizer from the nurse tank in which it is brought to the field to the tractor spray tank in which it is combined with the pesticide mixture.
Each of these types of agitation helps to keep the dispersed phase from settling out of the pesticide-fertilizer emulsion. Unfortunately, these devices are not always sufficient to prevent the mixture from separating. When separation occurs, the result is an uneven application of the pesticide over the field. Equipment failure may also result as the feed lines become clogged with thick portions which have separated from the mixture. The problem is more pronounced, of course, when equipment containing no agitation mechanism is used.
The problem becomes particularly acute when fertilizer, pesticide, and crop seeds are placed in the soil simultaneously or in close succession. It is a common practice to use a simple piece of planting apparatus, such as a corn planter, to dig a furrow, deposit a row of seeds therein, and place a fluid mixture containing the pesticide and a high potency fertilizer in parallel bands on either side of the seeded row. This is commonly referred to as "split-boot" application. A fertilizer of relatively high salt content, commonly referred to as a "starter" fertilizer, is used to provide an extra impetus to initiate crop growth. The pesticide meanwhile serves to control insects which attack the seeds and seedlings. Unlike tractors equipped with pumps and boom sprayers for broad area application, many planters have no inherent agitation beyond that provided by the normal jostling which occurs as they proceed across the field. The fluid mixture is often fed to the soil by a squeeze pump which is driven by the tractor wheels, providing very little agitation. Separation of the pesticide suspension can occur readily in such an apparatus. In addition, the fertilizer itself tends to promote separation, because emulsion stability generally decreases with increasing fertilizer salt content.
SUMMARY OF THE INVENTION
It has now been discovered that the stability of an emulsion containing an organophosphorus pesticide and an N-P or N-P-K fertilizer is substantially enhanced by the inclusion of an attapulgite clay. The present invention thus resides in a fertilizer composition comprising
(a) an aqueous solution of an N-P or N-P-K fertilizer, and
(b) an attapulgite clay,
which produces an emulsion of improved stability when combined with an emulsifiable concentrate of an organophosphorus pesticide.
In another aspect, the invention resides in an emulsion composition comprising
(a) an aqueous solution of an N-P or N-P-K fertilizer,
(b) an attapulgite clay, and
(c) an organophosphorus compound of the formula ##STR2## in which R 1 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, and C 1 -C 6 alkylthio, preferably selected from the group consisting of C 1 -C 4 alkoxy and C 1 -C 4 alkylthio,
R 2 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, and C 1 -C 6 alkylthio, preferably selected from the group consisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, and C 1 -C 4 alkylthio,
R 3 is selected from the group consisting of C 1 -C 6 alkyl, C 2 -C 8 alkylthioalkyl, phenyl, and C 7 -C 12 phenylthioalkyl, preferably selected from the group consisting of C 1 -C 3 alkyl, C 2 -C 6 alkylthioalkyl, phenyl, and C 7 -C 9 phenylthioalkyl, the phenyl rings optionally substituted with halogen, C 1 -C 3 alkyl, nitro, or C 1 -C 3 alkylsulfinyl,
X is oxygen or sulfur, and
Y is oxygen or sulfur.
In still another aspect, the invention resides in a method for simultaneously enhancing crop growth and controlling insects residing in soil comprising applying to the soil an emulsion composition comprising
(a) a crop growth enhancing amount of an aqueous solution of an N-P or N-P-K fertilizer,
(b) an attapulgite clay, and
(c) an insecticidally effective amount of an organophosphorus compound of the above formula.
As used in this specification, the term "alkyl" denotes a saturated hydrocarbon radical of straight or branched chain containing the specified number of carbon atoms. The carbon atom ranges are intended to be inclusive of their upper and lower limits.
The term "halogen" is intended to include fluorine, chlorine, bromine, and iodine. Chlorine and bromine are preferred, and chlorine is particularly preferred.
The term "crop growth enhancing amount" denotes any quantity of fertilizer which causes an increase in the size of the crop plants or in their rate of growth as a result of such quantity being applied to the soil in any conventional manner. Such increases can result from fertilizer applications before the seeds are planted, while the seeds are being planted, or after planting has taken place.
The term "insecticidally effective amount" denotes any quantity of pesticide which when applied to soil in any conventional manner causes death or a substantial inhibition of the metabolic functions of a significant portion of the insect pest population residing therein.
The term "attapulgite clay" is used herein to include any of the class of clays or clay-containing materials based on the mineral attapulgite. This mineral, which is mined principally in southwest Georgia and northeast Florida, is a hydrated aluminum silicate in a lattice structure which also contains magnesium. Attapulgite crystals have an acicular configuration and occur as bundles of laths, the individual laths attaining a maximum length of about 4 to 5 microns, a maximum thickness of about 50 to 100 Angstroms, and a width ordinarily two to three times the thickness. An average chemical analysis of a typical attapulgite clay is as follows:
______________________________________SiO.sub.2 60% (by weight)Al.sub.2 O.sub.3 10%MgO 10%Fe.sub.2 O.sub.3 4%CaO 2%K.sub.2 O 1%TiO.sub.2 0.5%other balance______________________________________
Attapulgite clays are available in dry form as well as in beneficiated form, in which they are predispersed in water with optional additional stabilizing components. Attapulgite granules which break down into small particles when contacted with water can also be used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the present invention, an attapulgite clay is combined with an aqueous solution of an N-P or N-P-K fertilizer and an emulsifiable organophosphorus pesticide concentrate to provide an emulsion of improved stability for a single field application. To achieve the fastest dispersion of the clay in the fluid mixture, the clay is preferably contacted with water prior to being contacted with the pesticide or the solvent in which the pesticide is dissolved. This preferred method is achieved by using a pre-formed aqueous dispersion of the clay or by adding the dry clay to the fertilizer solution before the emulsifiable concentrate is added. The uniformity of the dispersion can be improved by agitation using any conventional technique such as stirring, circulating, etc. The need for this agitation is dependent upon the quantity of clay used, the clay particle size, the length of time the dispersion remains in storage prior to use, etc. Agitation is also helpful in combining the aqueous clay dispersion with the emulsifiable pesticide concentrate, to form a more uniform emulsion and smaller droplets of the dispersed phase. These methods may be applied either at formulating plants or at actual field sites.
Although the attapulgite clay lessens the need for emulsifying agents, such agents are useful to provide further emulsion stability. Surface-active agents are the most common emulsifiers. Those in widest commercial use are the non-ionic and anionic agents, although cationic agents can also be used. Examples of non-ionic agents are long-chain alkyl and mercaptan polyethoxy alcohols, alkylaryl polyethoxy alcohols, sorbitan fatty esters, polyoxyethylene ethers, polyoxyethylene glycol esters, polyoxyethylene esters of fatty and resin acids, and mixtures of these. Examples of anionic agents are the calcium, amine, alkanolamine, and alkali salts of alkyl and alkylaryl sulfonates. Those most commonly used with fluid fertilizers include the ethoxylated and propoxylated mono- and diethers of phosphoric acid. The cationic agents include fatty amine blends, amine derivatives, and fatty alkylol amide condensates. Blends of non-ionic and anionic surface-active agents are of particular interest since the high degree of hydration which they create at the interfacial film is of particular benefit in stabilizing the emulsion.
The solvents used in the emulsifiable concentrates include those which are water-immiscible and those which are partially water-miscible, as well as those which are normally water-miscible when an organophosphorus pesticide is added. The solvents most frequently used in organophosphorus pesticide formulations are petroleum solvents such as xylenes and xylene derivatives, heavy aromatic naphthas, and kerosene. Other solvents include chlorobenzene, methylene chloride, ethylene dichloride and chlorotoluene. Any such solvents useful in traditional emulsifiable concentrates can be used in the present invention.
The relative quantities of the components of the present invention are not critical to the attainment of the improved result, since the improvement is achieved over a broad range of clay, fertilizer, and pesticide concentrations. In general, the relative quantities will be determined by the type of pesticide used, the type of fertilizer used, the crop to be fertilized, and the insects to be controlled, as well as general economic considerations.
It will be most convenient to use a quantity of clay which constitutes from about 0.1% to about 10.0% by weight of the aqueous phase of the final emulsion, or of the fertilizer solution if the fertilizer and clay are premixed prior to addition of the pesticide concentrate. The preferred clay concentration is from about 0.3% to about 3.0% by weight. Under certain conditions, the clay may interact with the pesticide to produce flocculation which may settle and detract from the uniformity of the emulsion. This can generally be eliminated, however, by adding additional clay to the emulsion.
Similarly, it will be most convenient to use a quantity of organophosphorus compound which constitutes from about 0.01% to about 10.0% by weight of the total emulsion, preferably from about 0.05% to about 5.0%. The emulsifiable concentrate generally contains from about 10% to about 90% by weight of the active ingredient, and most frequently from about 40% to about 70%.
The following examples are offered to illustrate the improvements attained by use of the present invention, and are not intended to limit or define the invention in any manner.
EXAMPLE 1
The following test data shows the improved results obtained from the addition of an attapulgite clay to a pesticide/fertilizer emulsifiable concentrate mixture.
Six different attapulgite clays were tested to demonstrate the general applicability of clays of the attapulgite type. The pesticide used in each case was O-ethyl-S-phenyl-ethylphosphonodithioate (known commercially as fonofos) in an emulsifiable concentrate of the following composition: pesticide, 47% by weight; heavy aromatic naphtha solvent, 45% by weight; and (phosphate ester)/(anionic emulsifying agent) blend, 8% by weight. The fertilizer used in each case was 8-24-6 liquid fertilizer.
According to the test procedure, the clay and fertilizer were thoroughly mixed by a laboratory centrifugal pump. The mixture was then poured into a 100-ml graduated cylinder up to a level corresponding to 97.5 ml. The emulsifiable pesticide concentrate was then added to bring the liquid level up to the 100-ml mark. The cylinder was then stoppered, inverted ten times, and placed in a location where it would be undisturbed so that periodic visual observations could be made. A control sample identical to the others but eliminating the use of clay was also tested and observed according to the same procedure.
The visual observations in each case consisted of noting the formation of cream and oil layers and recording their volumes. The formation of either or both of these layers indicates poor emulsion stability. The term "cream" refers to a region containing a higher proportion of the dispersed phase than the rest of the system. The cream layer is still an emulsion, since a dispersion still exists inside but formation of the cream layer indicates partial separation of the components of the emulsified composition and introduces nonuniformity to the system. The term "oil" refers to actual recombination of droplets of the dispersed phase to form a layer of solvent as a separate phase with pesticide dissolved therein.
The following clays were used:
______________________________________Attagel® 350 an attapulgite clay with sieve analysis: 34% +100 mesh 24% -325 meshAttaflow® an attapulgite clay dispersed in water-solids content 27% by weight, with residue sieve analysis: 99.6% -325 meshAttaclay® X-250 an attapulgite clay with sieve analysis: 85% -325 meshAttagel® 40 an attapulgite clay with average particle size 0.14 micronsAttapulgite 18/35 an attapulgite granule of +35, -18 mesh particle sizeMin-u-gel® 200 an attapulgite clay with sieve analysis: 95% -325 mesh______________________________________
All of the above clays are commercially available attapulgite-type clays. Min-u-gel 200 was obtained from Floridin Company, Pittsburgh, Pa., and the remainder were obtained from Engelhard Minerals and Chemicals Corporation, Edison, N.J. Attapulgite 18/35 is a granule which readily breaks down into small particles when placed in contact with water.
The test results are listed in Table I, which clearly shows that each sample which incorporated an attapulgite clay demonstrated a total absence of the oil layer and a reduction or elimination of the cream layer.
TABLE I______________________________________EMULSION STABILITY TESTSPesticide: O-Ethyl-S-phenyl-ethylphosphonodi- thioateFertilizer: 8-24-6Clay: various attapulgite types Cream/Oil Layers (ml) 1 hour 2 hours 4 hours______________________________________Control data - no clay present: t/1.0 1.0/1.0 1.0/1.0Test data - 1.0 weight % clay added to fertilizer:ClayAttagel 350 0/0 0/0 0/0Attaflow t/0 t/0 t/0Attaclay X-250 0/0 0/0 0/0Min-u-gel 200 0/0 0/0 0/0Attagel 40 0/0 0/0 0/0Attapulgite 18/35 0/0 0/0 0/0______________________________________ Symbol "t" denotes trace amount.
EXAMPLE 2
This example shows that the improvement of the present invention is observable over a broad range of clay concentration. The procedures followed were identical to those of Example 1. The materials and quantities were similar to those of Example 1, except that two different formulations of the same pesticide were used:
Formulation A: emulsifiable concentrate--O-ethyl-S-phenyl-ethylphosphonodithioate, 49% by weight; xylenic solvent (petroleumderived fraction containing about 35% xylenes and about 65% aromatics and heavier components), 41% by weight; phosphate ester emulsifying agent, 10% by weight.
Formulation B: emulsifiable concentrate--O-ethyl-S-phenyl-ethylphosphonodithioate, 47% by weight; heavy aromatic naphtha, 45% by weight; (phosphate ester)/(anionic emulsifying agent) blend, 8% by weight.
Using Attaflow and two types of fertilizers, 10-34-0 and 8-24-6, the results obtained are shown in Table II, which indicates that cream and oil layers were eliminated at all clay concentrations tested.
TABLE II______________________________________EMULSION STABILITY TESTSPesticide: O-Ethyl-S-phenyl-ethylphosphonodi- thioateFertilizer: 10-34-0, 8-24-6Clay: Attaflow at various concentrationsPesticide Clay Cream/Oil Layers (ml)Formulation Fertilizer Content 1 hour 2 hours 4 hours______________________________________(Control Data)A 10-34-0 -- 1.5/1.5 1.0/2.0 2.0/2.0A 8-24-6 -- 0.5/1.5 0.5/2.0 0.5/2.0B 10-34-0 -- t/2.0 t/2.0 0.5/2.0B 8-24-6 -- t/1.0 1.0/1.0 1.0/1.0(Test Data)A 10-34-0 0.3 0/t 0/t 0/0A 10-34-0 0.6 0/0 0/0 0/0A 10-34-0 1.0 0/0 0/0 0/0A 10-34-0 1.2 0/0 0/0 0/0*A 10-34-0 1.4 0/0 0/0 0/0*A 10-34-0 1.6 0/0 0/0 0/0A 10-34-0 2.0 0/0 0/0 0/0A 10-34-0 3.0 0/0 0/0 0/0A 8-24-6 0.4 0/0* 0/0* 0/0*A 8-24-6 0.6 0/0* 0/0* 0/0*A 8-24-6 0.8 0/0 0/0 0/0A 8-24-6 1.0 0/0 0/0 0/0A 8-24-6 1.2 0/0 0/0 0/0A 8-24-6 1.5 0/0 0/0 0/0B 10-34-0 0.8 0/0 0/0* 0/0*B 10-34-0 1.0 0/0 0/0 0/0B 10-34-0 1.2 0/0 0/0 0/0B 10-34-0 1.4 0/0 0/0 0/0B 10-34-0 1.6 0/0 0/0 0/0B 10-34-0 2.0 0/0 0/0 0/0B 10-34-0 3.0 0/0 0/0 0/0B 8-24-6 0.4 0/0 0/0 0/0B 8-24-6 0.6 0/0 0/0 0/0B 8-24-6 0.8 0/0 0/0 0/0B 8-24-6 1.0 0/0 0/0 0/0B 8-24-6 1.2 0/0 0/0 0/0______________________________________ NOTES: Clay content is expressed as weight percent of total mixture. Symbol "t" denotes trace amount. Symbol "*" denotes occurrence of flocculation.
EXAMPLE 3
This example demonstrates the efficacy of the present invention over a broad range of fertilizers. Again, the procedures of Example 1 were followed, although six different liquid fertilizers were used. Pesticide Formulation A of Example 2, and the predispersed attapulgite-type clay Attaflow were used in all tests. The results are shown in Table III, which indicates complete elimination of cream and oil layers in every case.
TABLE III______________________________________EMULSION STABILITY TESTSPesticide: O-Ethyl-S-phenyl-ethylphosphonodi- thioateFertilizer: variousClay: Attaflow, approximately 1.0 weight % of total Cream/Oil Layers (ml) Control (no clay) Test (clay present)Fertilizer 1 hour 4 hours 1 hour 4 hours______________________________________16-16-4 2.0/0 2.0/0 0/0 0/0*7-21-7 1.0/2.0 1.0/2.5 0/0 0/0*4-10-10 0/t 6.0/2.0 0/0* 0/0*19-19-0 3.0/0 3.0/0 0/0 0/020-10-0 1.5/0 * t/0 t/09-27-5 3.0/1.5 3.0/1.5 0/0 0/0______________________________________ NOTES:- Symbol "t" denotes tract amount Symbol "*" denotes occurrence of flocculation
EXAMPLE 4
This example demonstrates the efficacy of the present invention over a broad range of insecticide concentration. Again, the procedures of Example 1 were followed, this time varying the quantity of pesticide formulation rather than using a fixed quantity of 2.5 ml. Both Formulations A and B of Example 2 were used, together with 10-34-0 and 8-24-6 fertilizers, and the predispersed attapulgite clay Attaflow at approximately 1% by weight of the total mixture. The results, shown in Table IV, indicate the complete elimination of cream and oil layers at every concentration.
TABLE IV______________________________________EMULSION STABILITY TESTSPesticide: O-Ethyl-O-phenyl-ethylphosphonodi- thioate at various concentrationsFertilizer: 10-34-0, 8-24-6Clay: Attaflow, approximately 1.0 weight % of totalPesticide Pesticide Cream/Oil Layers (ml)Formulation Amount Fertilizer 1 hour 4 hours______________________________________(Control Data)A 2.5 10-34-0 1.5/1.5 2.0/2.0A 2.5 8-24-6 0.5/1.5 0.5/2.0B 2.5 10-34-0 t/2.0 0.5/2.0B 2.5 8-24-6 t/1.0 1.0/1.0(Test Data)A 1.0 10-34-0 0/0 0/0A 2.0 10-34-0 0/0 0/0A 3.0 10-34-0 0/0 0/0A 4.0 10-34-0 0/0 0/0A 1.0 8-24-6 0/0 0/0A 2.0 8-24-6 0/0 0/0*A 3.0 8-24-6 0/0 0/0*A 4.0 8-24-6 0/0 0/0*B 1.0 10-34-0 0/0 0/0B 2.0 10-34-0 0/0 0/0B 4.0 10-34-0 0/0 0/0*B 4.0 10-34-0 0/0 0/0*B 1.0 8-24-6 0/0 0/0B 2.0 8-24-6 0/0 0/0B 3.0 8-24-6 0/0 0/0B 4.0 8-24-6 0/0 0/0______________________________________ NOTES: Pesticide amount is expressed as volume percent of concentrate with respect to total mixture (equivalent to ml) Symbol "*" denotes occurrence of flocculation Symbol "t" denotes trace amount
EXAMPLE 5
This example demonstrates the efficacy of the present invention over a broad range of organophosphorus insecticides. The procedures of Example 1 were followed, using five commercially available pesticides:
O,O-Diethyl-S[2-(ethylthio)-ethyl]phosphorodithioate, common name disulfoton, trade name DI-SYSTON®--obtained from Mobay Chemical Corporation, Kansas City, Mo.--as emulsifiable concentrate containing 6 lb active ingredient per gallon (0.72 kg/l)
O,O-Diethyl-O-(p-methylsulfinylphenyl) phosphorothioate, common name fensulfothion, trade name DASANIT®--obtained from Mobay Chemical Corporation--as emulsifiable concentrate containing 6 lb active ingredient per gallon (0.72 kg/l)
O-Ethyl-S,S-dipropylphosphorodithioate, common name ethoprop, trade name MOCAP®--obtained from Mobil Chemical Company, Richmond, Va.--as emulsifiable concentrate containing 6 lb active ingredient per gallon (0.72 kg/l)
O,O-Dimethyl O-p-nitrophenyl phosphorothioate, common name methyl parathion--obtained from Stauffer Chemical Company--as 4 lb/gal (0.48 kg/l) emulsifiable concentrate
S-[(p-Chlorophenyl)thio]methyl O,O-diethyl phosphorodithioate, common name carbophenothion, trade name TRITHION--obtained from Stauffer Chemical Company--as 4 lb/gal (0.48 kg/l) and 8 lb/gal (0.96 kg/l) emulsifiable concentrate.
Fertilizers 10-34-0 and 8-24-6 were used with the predispersed attapulgite clay Attaflow at approximately 1% by weight of the total mixture. The results, shown in Table V, indicate almost complete elimination of cream and oil layers in each case.
TABLE V______________________________________EMULSION STABILITY TESTSPesticide: various organophosphorus compoundsFertilizers: 10-34-0, 8-24-6Clay: Attaflow, approximately 1.0 weight % of total except where indicated Cream/Oil Layers (ml) Control Test (no clay) (clay present)Pesticide Fertilizer 1 hour 4 hours 1 hour 4 hours______________________________________MOCAP 10-34-0 0.5/1.5 0.5/1.5 0/t 0/t 8-24-6 0.5/1.5 0.5/2.0 0/0 0/0DI-SYSTON 10-34-0 0.5/1.5 0.5/1.5 0/t 0/t 8-24-6 t/2.0 t/2.0 0/0 0/tDASANIT 10-34-0 0.5/1.5 0.5/1.5 0/t 0/t 8-24-6 1.0/1.5 1.0/1.5 0/0 0/0PARATHION 10-34-0 0/3.0 0/3.0 0/1.0* 0/1.25* 8-24-6 0/2.0 0/2.5 0/t 0/tTRITHION 10-34-0 0/4.0 0/4.0 0/1.5* 0/1.75*4 lb/gal 8-24-6 0/2.5 0/2.75 0/t* 0/t*TRITHION 10-34-0 0/3.0 0/3.5 0/t 0/0.258 lb/gal 8-24-6 0/2.0 0/2.5 t/0 t/0______________________________________ NOTES: Symbol "" denotes trace amount. Asterisk denotes clay concentration of 2% rather than 1%
METHODS OF APPLICATION
In general, any conventional method of application of a liquid composition can be used in applying the compositions of the present invention to a field. The locus of application can be soil, seeds, seedlings, or the actual crop plants, as well as flooded fields. Typical application methods include the use of boom sprayers, hand-held sprayers, and airplane-mounted sprayers, as well as direct furrow application from a planting tractor, as in the "split-boot" technique described above.
The compositions can also be applied to the soil through irrigation systems. According to this technique, the compositions are added directly to irrigation water immediately prior to irrigation of the field. This technique is applicable in all geographical areas regardless of rainfall, since it permits supplementation of the natural rainfall at critical stages of plant growth. The irrigation water can be applied by the use of sprinkler systems, surface furrows, or flooding. Such application is most effectively done before the weeds germinate, either early in the spring prior to germination or within two days after cultivation of the field.
The amount of composition which constitutes an insecticidally effective and crop growth enhancing amount depends upon the nature of the insects to be controlled and the crop to be grown. The rate of application of each ingredient varies from about 0.01 to about 500 pounds per acre, preferably about 0.1 to about 50 pounds per acre with the actual amount used depending on the overall cost and the desired results. It will be readily apparent to one skilled in the art that compositions exhibiting lower insecticidal activity will require a higher dosage rate for the same degree of control than more active compositions.
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A novel composition is disclosed, comprising
(a) an aqueous solution of an N-P or N-P-K fertilizer and
(b) an attapulgite clay. The composition provides improved emulsion stability when combined with an emulsifiable concentrate of an organophosphorus compound of the formula ##STR1## in which R 1 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, and C 1 -C 6 alkylthio,
R 2 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, and C 1 -C 6 alkylthio,
R 3 is selected from the group consisting of C 1 -C 6 alkyl, C 2 -C 8 alkylthioalkyl, phenyl, and C 7 -C 12 phenylthioalkyl, the phenyl rings optionally substituted with halogen, C 1 -C 3 alkyl, nitro, or C 1 -C 3 alkylsulfinyl,
X is oxygen or sulfur, and
Y is oxygen or sulfur.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention is related to the field of communications, in particular, to providing for language translation during an active voice call so that parties speaking different languages may have a conversation.
[0003] 2. Statement of the Problem
[0004] It is sometimes the case that a calling party places a call to a called party that does not speak the same language as the calling party, such as when the call is placed to a foreign country. For instance, the calling party may speak English while the called party may speak French. When the parties to the call speak different languages, no meaningful conversation can take place. It may be possible with the proper planning before the call to use an interpreter to translate between the languages of the parties, but use of the interpreter may be inconvenient, may lengthen the time of the call, or may have other drawbacks. It is thus a problem for parties that speak different languages to communicate via a voice call.
SUMMARY OF THE SOLUTION
[0005] Embodiments of the invention solve the above and other related problems by providing communication networks and/or communication devices that are adapted to translate voice communications for a call from one language to another in real time. For instance, if a calling party speaks English and a called party speaks French, then the communication network connecting the parties may translate voice communications from the calling party from English to French, and provide the voice communications to the called party in French. Also, the communication network may translate voice communications from the called party from French to English, and provide the voice communications to the calling party in English. The real-time voice translation as provided herein advantageously allows parties that speak different languages to have a meaningful conversation over a voice call.
[0006] In one embodiment, a communication network is adapted to translate voice communications for calls from one language to another. When a call is placed or initiated from a calling party to a called party, the communication network receives voice communications for the call from the calling party. The calling party's voice communications are in a first language, such as English. The communication network identifies the first language understood by the calling party, and identifies a second language understood by the called party. To identify the languages of the parties, the communication network may prompt the calling party and/or the called party for the languages, may receive indications of the languages in a signaling message for the call, may access a database having a pre-defined language indication for the parties, etc. The communication network then translates the calling party's voice communications in the first language to the second language understood by the called party, such as French. The communication network then transmits the calling party's voice communications in the second language to the called party. The called party may then listen to the calling party's voice communications in the second language.
[0007] The communication network also receives voice communications for the call from the called party for a full duplex call. The called party's voice communications are in the second language. The communication network translates the called party's voice communications in the second language to the first language. The communication network then transmits the called party's voice communications in the first language to the calling party, where the calling party may listen to the called party's voice communications in the first language.
[0008] In another embodiment, a communication device (e.g., a mobile phone) is adapted to translate voice communications for calls from one language to another. Assume for this embodiment that the communication device is being operated by a calling party initiating a call to a called party. The communication device receives voice communications for the call from the calling party, such as through a microphone or similar device. The calling party's voice communications are in a first language. The communication device identifies a second language for translation, such as a language understood by the called party, or a common language agreed upon. The communication device then translates the calling party's voice communications in the first language to the second language. The communication device provides the calling party's voice communications in the second language to the called party, such as by transmitting the calling party's voice communications in the second language over a communication network for receipt by the called party.
[0009] The communication device also receives voice communications for the call from the called party over the communication network. The called party's voice communications are in the second language. The communication device translates the called party's voice communications in the second language to the first language. The communication device then provides the called party's voice communications in the first language to the calling party, such as through a speaker. The calling party may then listen to the called party's voice communications in the first language.
[0010] The invention may include other exemplary embodiments described below.
DESCRIPTION OF THE DRAWINGS
[0011] The same reference number represents the same element or same type of element on all drawings.
[0012] FIG. 1 illustrates a communication network in an exemplary embodiment of the invention.
[0013] FIGS. 2-3 are flow charts illustrating methods of operating a communication network to translate voice communications for calls from one language to another in an exemplary embodiment of the invention.
[0014] FIG. 4 illustrates a communication device in an exemplary embodiment of the invention.
[0015] FIGS. 5-6 are flow charts illustrating methods of operating a communication device to translate voice communications for calls from one language to another in an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIGS. 1-6 and the following description depict specific exemplary embodiments of the invention to teach those skilled in the art how to make and use the invention. For the purpose of teaching inventive principles, some conventional aspects of the invention have been simplified or omitted. Those skilled in the art will appreciate variations from these embodiments that fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described below, but only by the claims and their equivalents.
[0017] FIG. 1 illustrates a communication network 100 in an exemplary embodiment of the invention. Communication network 100 may comprise a cellular network, an IMS network, a Push to Talk over Cellular (PoC), or another type of network. Communication network 100 includes a session control system 110 adapted to serve a communication device 114 of a party 112 . Session control system 110 comprises any server, function, or other system adapted to serve calls or other communications from party 112 . For example, in a cellular network, such as a CDMA or UMTS network, session control system 110 may comprise a MSC/VLR. In an IMS network, session control system 110 may comprise a Call Session Control Function (CSCF). Communication device 114 comprises any type of communication device adapted to place and receive voice calls, such as a cell phone, a PDA, a VoIP phone, or another type of device.
[0018] Communication network 100 further includes a session control system 120 adapted to serve a communication device 124 of a party 122 . Session control system 120 comprises any server, function, or other system adapted to serve calls or other communications from party 122 . Communication device 124 comprises any type of communication device adapted to place and receive voice calls, such as a cell phone, a PDA, a VoIP phone, or another type of device.
[0019] Although two session control systems 110 , 120 are shown in FIG. 1 , those skilled in the art understand that communication device 114 and communication device 124 may be served by the same session control system. Also, although session control systems 110 and 120 are shown as part of the same communication network 100 , these two systems may be implemented in different networks possibly operated by different service providers. For instance, session control system 110 may be implemented in an IMS network while session control system 120 may be implemented in a CDMA network.
[0020] Communication network 100 further includes a translator system 130 . Translator system 130 comprises any server, application, database, or system adapted to translate voice communications for calls from one language to another language in substantially real-time. Translator system 130 is illustrated in FIG. 1 as a stand alone system or server in communication network 100 . In such an embodiment, translator system 130 includes a network interface 132 and a processing system 134 . In other embodiments, translator system 130 may be implemented in existing facilities in communication network 100 . As an example, if session control system 110 comprises a Central Office (CO) of a PSTN, then translator system 130 may be implemented in the CO. The functionality of translator system 130 , which will be further described below, may be distributed among multiple facilities of communication network 100 . As an example, some functions of translator system 130 may be performed by session control system 110 while other functions of translator system 130 may be performed by session control system 120 .
[0021] Assume that party 112 wants to place a call to party 122 , but that party 112 speaks a different language than party 122 . For the below embodiment, party 112 is referred to as “calling party” and party 122 is referred to as “called party”. According to embodiments provided herein, a call may be established between a calling party 112 and a called party 122 , and translator system 130 translates between the languages of calling party 112 and called party 122 during an active voice call as follows.
[0022] FIG. 2 is a flow chart illustrating a method 200 of operating communication network 100 to translate voice communications for calls from one language to another in an exemplary embodiment of the invention. The steps of method 200 will be described with reference to communication network 100 in FIG. 1 . The steps of the flow chart in FIG. 2 are not all inclusive and may include other steps not shown. The steps of the flow chart are also not indicative of any particular order of operation, as the steps may be performed in an order different than that illustrated in FIG. 2 .
[0023] In step 202 of method 200 , translator system 130 receives voice communications for the call from calling party 112 through network interface 132 . The voice communications from calling party 112 represent the segment or portion of the voice conversation as spoken by calling party 112 . The voice communications from calling party 112 are in a first language, such as English.
[0024] In steps 204 and 206 , processing system 134 of translator system 130 identifies the first language understood by calling party 112 , and identifies a second language understood by called party 122 . Processing system 134 may identify the languages of parties 112 and 122 in a variety of ways. In one example, processing system 134 may prompt calling party 112 and/or called party 122 for the languages spoken by each respective party. In another example, processing system 134 may receive indications of the languages in a signaling message for the call. Calling party 112 may enter a feature code or another type of input into communication device 114 indicating the languages of calling party 112 and/or called party 122 responsive to which communication device 114 transmits the language indications to translator system 130 in a signaling message. Calling party 112 may also program communication device 114 to automatically provide an indication of a preferred or understandable language to translator system 130 upon registration, upon initiation of a call, etc. In another example, processing system 134 may access a database having a pre-defined language indication for parties 112 and 122 . Processing system 134 may identify the languages of parties 112 and 122 in other desired ways.
[0025] In step 208 , processing system 134 translates the voice communications from calling party 112 in the first language to the second language that is understood by called party 122 . As an example, processing system 134 may translate the voice communications from calling party 112 from English to French. Processing system 134 may store a library of language files and associated conversion or translation algorithms between the language files. Responsive to identifying the two languages of parties 112 and 122 , processing system 134 may access the appropriate language files and appropriate conversion algorithm to translate the voice communications in substantially real-time during the call.
[0026] In step 210 , network interface 132 transmits the voice communications for calling party 112 in the second language to called party 122 . Called party 122 may then listen to the voice communications of calling party 112 in the second language instead of the first language originally spoken by calling party 112 . Called party 122 can advantageously understand the spoken words of calling party 112 through the translation even though called party 122 does not speak the same language as calling party 112 .
[0027] Because many voice calls are full duplex, translator system 130 is also adapted to translate voice communications from called party 122 in the second language to the first language understood by calling party 112 . FIG. 3 is a flow chart illustrating a method 300 of operating communication network 100 to translate voice communications for calls from one language to another in an exemplary embodiment of the invention. The steps of method 300 will be described with reference to communication network 100 in FIG. 1 . The steps of the flow chart in FIG. 3 are not all inclusive and may include other steps not shown.
[0028] In step 302 of method 300 , network interface 132 of translator system 130 receives voice communications for the call from called party 122 . The voice communications from called party 122 represent the segment or portion of the voice conversation as spoken by called party 122 . The voice communications from called party 122 are in the second language, such as French. In step 304 , processing system 134 translates the voice communications from called party 122 in the second language to the first language that is understood by calling party 112 . As an example, processing system 134 may translate the voice communications from called party 122 from French to English. In step 306 , network interface 132 transmits the voice communications for called party 122 in the first language to calling party 112 . Calling party 112 may then listen to the voice communications of called party 122 in the first language instead of the second language originally spoken by called party 122 . Calling party 112 can advantageously understand the spoken words of called party 122 through the translation even though calling party 112 does not speak the same language as called party 122 .
[0029] As is illustrated in the above embodiment, parties 112 and 122 speaking different languages are able to effectively communicate over a voice call through translator system 130 . Although the above embodiment illustrated a call between two parties, translator system 130 may translate between languages of three or more parties that are on a conference call. The translation in the above embodiment is accomplished through a network-based solution. However, the translation may additionally or alternatively be performed in communication device 114 and/or communication device 124 . The following describes translation as performed in a communication device.
[0030] FIG. 4 illustrates a communication device 114 in an exemplary embodiment of the invention. Communication device 114 includes a network interface 402 , a processing system 404 , and a user interface 406 . Network interface 402 comprises any components or systems adapted to communicate with communication network 100 . Network interface 402 may comprise a wireline interface or a wireless interface. Processing system 404 comprises a processor or group of inter-operational processors adapted to operate according to a set of instructions. The instructions may be stored on a removable card or chip, such as a SIM card. User interface 406 comprises any components or systems adapted to receive input from a user, such as a microphone, a keypad, a pointing device, etc, and/or convey content to the user, such as a speaker, a display, etc. Although FIG. 4 illustrates communication device 114 , communication device 124 may have a similar configuration.
[0031] Assume again that party 112 wants to place a call to party 122 . According to embodiments provided herein, a call may be established between calling party 112 and called party 122 , and communication device 114 translates between the languages of calling party 112 and called party 122 during an active voice call as follows.
[0032] FIG. 5 is a flow chart illustrating a method 500 of operating communication device 114 to translate voice communications for calls from one language to another in an exemplary embodiment of the invention. The steps of method 500 will be described with reference to communication network 100 in FIG. 1 and communication device 114 in FIG. 4 . The steps of the flow chart in FIG. 5 are not all inclusive and may include other steps not shown. The steps of the flow chart are also not indicative of any particular order of operation, as the steps may be performed in an order different than that illustrated in FIG. 5 .
[0033] In step 502 of method 500 , processing system 404 in communication device 114 receives voice communications for the call from calling party 112 through user interface 406 . For instance, user interface 406 may be a microphone adapted to detect the audible voice frequencies of calling party 112 . The voice communications from calling party 112 are in a first language. In step 504 , processing system 404 identifies a second language of translation for the voice communications. The second language may be a language understood by called party 122 , may be a pre-defined or common language, etc. Processing system 404 may identify the first language and/or second language in a variety of ways. In one example, processing system 404 may prompt calling party 112 for the languages spoken by each respective party. In another example, processing system 404 may receive input from calling party 112 indicating the languages of calling party 112 and/or called party 122 . Processing system 404 may identify the languages of parties 112 and 122 in other desired ways.
[0034] In step 506 , processing system 404 translates the voice communications from calling party 112 in the first language to the second language. Processing system 404 may store a library of language files and associated conversion or translation algorithms between the language files. Responsive to identifying the two languages of parties 112 and 122 , processing system 404 may access the appropriate language files and appropriate conversion algorithm. Processing system 404 may then translate the voice communications in substantially real-time during the call.
[0035] In step 508 , processing system 404 provides the voice communications for calling party 112 in the second language for receipt by called party 122 . For instance, processing system 404 may transmit the voice communications over communication network 100 through network interface 402 to communication device 124 of called party 122 . Called party 122 may then listen to the voice communications of calling party 112 in the second language instead of the first language originally spoken by calling party 112 . Alternatively, communication device 124 may translate the voice communications in the second language to a third language understood by called party 122 . Called party 122 can advantageously understand the spoken words of calling party 112 through the translation even though called party 122 does not speak the same language as calling party 112 .
[0036] Communication device 114 is also adapted to translate voice communications from called party 122 in the second language to the first language understood by calling party 112 . FIG. 6 is a flow chart illustrating a method 600 of operating communication device 114 to translate voice communications for calls from one language to another in an exemplary embodiment of the invention. The steps of method 600 will be described with reference to communication network 100 in FIG. 1 and communication device 114 in FIG. 4 . The steps of the flow chart in FIG. 6 are not all inclusive and may include other steps not shown.
[0037] In step 602 of method 600 , processing system 404 receives voice communications for the call through network interface 402 from called party 122 . In step 604 , processing system 404 translates the voice communications from called party 122 in the second language to the first language that is understood by calling party 112 . In step 606 , processing system 404 provides the voice communications for called party 122 in the first language to calling party 112 . For instance, user interface 406 may comprise a speaker adapted to emit audible voice frequencies of called party 122 that may be heard by calling party 112 . Calling party 112 may then listen to the voice communications of called party 122 in the first language instead of the second language originally spoken by called party 122 . Calling party 112 can advantageously understand the spoken words of called party 122 through the translation even though calling party 112 does not speak the same language as called party 122 .
[0038] Processing system 404 in communication device 114 (see FIG. 4 ) may not necessarily translate the voice communications from calling party 112 to a language that is understood by called party 122 . Processing system 404 may convert the voice communications from calling party 112 to a pre-defined or common language and it is the responsibility of communication device 124 of called party 122 to convert the voice communications from the pre-defined language to the language understood by called party 122 . For example, assume that calling party 112 speaks German and called party 122 speaks French. Processing system 404 of communication device 114 may translate the German speech of calling party 112 to English, and transmit the voice communications for calling party 112 in English. Communication device 124 of called party 122 would then receive the voice communications of calling party 112 in English. Because called party 122 understands French, communication device 124 would translate the voice communications from English to French.
[0039] Although the above description was in reference to communication device 114 , communication device 124 of called party 122 may operate in a similar manner to translate received voice communications to a language understood by called party 122 . Other communication devices not shown in FIG. 1 also may operate in a similar manner to translate the voice communications. For instance, this type of language translation may be beneficial in conference calls where there are three or more communication devices on a call. In a conference call scenario, a communication device of a first party may translate the voice communications from that party to a language pre-defined or agreed upon for the conference, or may convert the voice communications to a common language. For example, assume that a first party speaks German, a second party speaks English, and a third party speaks French. The communication device of the first party may translate voice communications from German to English, and transmit the voice communications to communication network 100 . Similarly, the communication device of the third party may translate voice communications from French to English, and transmit the voice communications to communication network 100 . The parties to the conference call may then be able to communicate because their communication devices converted the spoken languages to a common language, such as English.
EXAMPLES
[0040] The following describes examples of translating voice communications for calls from one language to another. In FIG. 1 , assume again that party 112 wants to place a call to party 122 , but that party 112 speaks a different language than party 122 . In this first example, communication network 100 provides the functionality to translate from one language to another. In other words, communication device 114 and/or communication device 124 may not need any special functionality to allow for language translation.
[0041] To place a call to called party 122 , calling party 112 dials the number for called party 122 in communication device 114 , selects called party 122 from a contact list, etc. Responsive to initiation of the call, communication device 114 generates a signaling message for the call, such as an SS7 Initial Address Message (IAM) or a SIP INVITE message, and transmits the signaling message to session control system 110 . To instruct communication network 100 that a language translation is needed for this call, calling party 112 may enter a feature code, such as *91, into communication device 114 . The feature code may additionally indicate one or more languages that will be involved in the translation. For instance, the feature code *91 may indicate an English to French translation is desired. In some real-life situations, especially in case of conference calls, we may just know the language of choice at each end-point. In such cases, the network will know the needed language conversion from each caller to each called party. Communication device 114 then transmits the feature code to session control system 110 . Responsive to the receiving the feature code, session control system 110 notifies translator system 130 (which may actually be implemented in session control system 110 ) that voice communications for the call will need to be translated.
[0042] Responsive to the notification, translator system 130 identifies the first language understood by calling party 112 , and identifies a second language understood by called party 122 . In this example, translator system 130 identifies the first language of calling party 112 by prompting calling party 112 . Translator system 130 may include an Interactive Voice Response (IVR) unit that provides a menu to calling party 112 requesting calling party 112 to select an understood language. In a similar manner, translator system 130 identifies the second language of called party 122 by prompting called party 122 .
[0043] When the call is set up between calling party 112 and called party 122 , assume that calling party 112 begins speaking into communication device 114 . Communication device 114 detects the voice frequencies of calling party 112 and transmits voice communications for the call to session control system 110 . Session control system 110 routes the voice communications from calling party 112 to translator system 130 . Translator system 130 then translates the voice communications from calling party 112 in the first language to the second language that is understood by called party 122 . Translator system 130 then transmits the voice communications for calling party 112 in the second language to called party 122 . Translator system 130 performs this translation function in real-time during the active voice call. As a result, called party 122 listens to the voice communications of calling party 112 in the second language instead of the first language originally spoken by calling party 112 . A similar process occurs to translate voice communications from called party 122 to calling party 112 .
[0044] In a second example, assume again that party 112 wants to place a call to party 122 . In this example, communication device 114 prompts calling party 112 for the languages to convert between, and communication network 100 provides the translation. Calling party 112 initiates the call to called party 122 . Responsive to initiation of the call, communication device 114 prompts calling party 112 for the language in which calling party 112 will be speaking (the first language), and also prompts calling party 112 for the language of called party 122 (the second language), or in other words the language to which the voice communications will be translated. Communication device 114 then generates a signaling message for the call, and transmits the signaling message to session control system 110 . The signaling message includes an indication of the first language and the second language. Responsive to the receiving the signaling message, session control system 110 transmits the indication of the first language and the second language to translator system 130 . Translator system 130 is then able to identify the first language understood by calling party 112 , and to identify the second language understood by called party 122 based on the indications provided in the signaling message.
[0045] When the call is then set up between calling party 112 and called party 122 , assume that calling party 112 begins speaking into communication device 114 . Communication device 114 detects the voice frequencies of calling party 112 and transmits voice communications for the call to session control system 110 . Session control system 110 routes the voice communications from calling party 112 to translator system 130 . Translator system 130 then translates the voice communications from calling party 112 in the first language to the second language that is understood by called party 122 . Translator system 130 then transmits the voice communications for calling party 112 in the second language to called party 122 . Translator system 130 performs this translation function in real-time during the active voice call. As a result, called party 122 listens to the voice communications of calling party 112 in the second language instead of the first language originally spoken by calling party 112 . A similar process occurs to translate voice communications from called party 122 to calling party 112 .
[0046] In a third example, assume again that party 112 wants to place a call to party 122 . In this example, communication device 114 provides the functionality to translate from one language to another. Calling party 112 initiates the call to called party 122 . Responsive to initiation of the call, communication device 114 prompts calling party 112 for the language in which calling party 112 will be speaking (the first language), and also prompts calling party 112 for the language of called party 122 (the second language). Communication device 114 then generates a signaling message for the call, and transmits the signaling message to session control system 110 to set up the call to called party 122 . When the call is then set up between calling party 112 and called party 122 , assume that calling party 112 begins speaking into communication device 114 . Communication device 114 detects the voice frequencies of calling party 112 that represent the voice communications of calling party 112 that are in the first language. Communication device 114 translates the voice communications from calling party 112 in the first language to the second language that is understood by called party 122 . Communication device 114 then transmits the voice communications for calling party 112 in the second language to called party 122 over communication network 100 . Communication device 114 performs this translation function in real-time during the active voice call. As a result, called party 122 listens to the voice communications of calling party 112 in the second language instead of the first language originally spoken by calling party 112 . A similar process occurs to translate voice communications from called party 122 to calling party 112 .
[0047] In a fourth example, if a calling party 112 initiates the call to called party 122 , then communication device 114 prompts calling party 112 for the language in which calling party 112 will be speaking (the first language). Communication device 114 also identifies a second language that is a common language agreed upon for transmission over communication network 100 . For instance, the agreement may be to transmit voice communications in English over communication networks 100 in the United States. Communication device 114 then generates a signaling message for the call, and transmits the signaling message to session control system 110 to set up the call to called party 122 . When the call is then set up between calling party 112 and called party 122 , assume that calling party 112 begins speaking into communication device 114 . Communication device 114 detects the voice frequencies of calling party 112 that represent the voice communications of calling party 112 that are in the first language. Communication device 114 translates the voice communications from calling party 112 in the first language to the second language. Communication device 114 then transmits the voice communications for calling party 112 in the second language over communication network 100 .
[0048] Upon receipt of the voice communications in the second language, communication device 124 may provide the voice communications to called party 122 if they are in the appropriate language. However, if called party 122 does not speak the second language, then communication device 124 prompts called party 122 for the language in which called party 122 will be speaking (a third language). Communication device 124 then translates the voice communications from calling party 112 in the second language to the third language understood by called party 122 . Communication device 124 then provides the voice communications calling party 112 in the third language, such as through a speaker.
[0049] A similar process occurs to translate voice communications from called party 122 to calling party 112 .
[0050] Although specific embodiments were described herein, the scope of the invention is not limited to those specific embodiments. The scope of the invention is defined by the following claims and any equivalents thereof.
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Communication networks, communication devices, and associated methods are disclosed for translating voice communications for calls from one language to another. When a call is placed from a first party to a second party, the communication network receives voice communications for the call from the first party that are in a first language. The communication network identifies the first language of the first party and a second language of the second party. The communication network then translates the first party's voice communications in the first language to the second language, and transmits the first party's voice communications in the second language to the second party. The second party may listen to the first party's voice communications in the second language. The communication network also translates the second party's voice communications from the second language to the first language so that the first party may listen to the second party's voice communications.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit from U.S. Provisional Application No. 61/651,345, filed May 24, 2012, the entire contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a system for improving the aerodynamic profile of vehicles by utilizing side vehicle fairing structures, especially for use on an intermodal chassis used to transport intermodal shipping containers by road (“Chassis” or “Chasses”). Additionally, the system can be employed on any trailer used in a tractor-trailer combined vehicle (“Truck”). The system improves fuel consumption without having a material adverse impact on operation or service procedures pertinent to the Truck.
2. Description of Related Art
The amount of power needed to move a vehicle over land or through the air increases with the speed of the vehicle due to aerodynamic drag. The amount of power necessary to overcome aerodynamic drag directly translates into increased fuel consumption, and thus increased emission of greenhouse gases and pollutants, and increased cost of operation.
A variety of innovations aimed at reducing the aerodynamic drag of various transport vehicles, including tractor-trailer combinations, have been introduced in the prior art. These include efforts to make the hood, windscreen, fenders, etc. more streamlined in form, as well as by adding fairings to the cab roof, and in some cases, to the trailer when the trailer is a “box” van or refrigerated heavy duty truck trailers. Hereinafter standard van and refrigerated “box” heavy duty truck trailers shall be referred to as “Van Trailer(s)”.
U.S. Pat. No. 6,799,791 discloses a vehicle fairing structure that can be deployed on the rear of a Van Trailer box to reduce drag at the rear end of the Van Trailer box. Since a significant amount of drag is also associated with the front of the Van Trailer box, where there is known to be an area of high pressure and relatively stagnant air approximately at the middle of the forward vertical face of the trailer cab, a front fairing structure for reducing this drag is disclosed in U.S. Pat. No. 7,604,284.
It is also the case that significant drag results from air entering under the Van Trailer, between the box and the road surface. A system that includes side fairings to reduce drag such is disclosed in U.S. Pat. No. 7,404,592. The foregoing patent and applications (The disclosures of U.S. Pat. Nos. 6,799,791, 7,604,284 and 7,404,592 are incorporated herein by reference.
While the foregoing side fairing systems are suitable for Van Trailer boxes, a significant amount of freight is moved using intermodal systems. In such systems, the trailer box is a separate component from the trailer chassis, so that multiple boxes (referred to as containers) can be stacked on container ships or flatbed railcars and single containers can be mounted on trailers for transit by Truck. When the containers are moved between their originating/final destinations by road or Truck, Chasses specially designed to accommodate the container are utilized. A crane or a forklift is typically used to lift a container on to and off of the Chassis.
Utilizing a side fairing in an intermodal application to reduce aerodynamic drag is challenging, because the design needs to take into account the foregoing modes of operation. To permit easier movement and stacking of containers, it may be desirable to secure the side fairing to the Chassis rather than the container. However, any side fairing design must take into consideration that the container may be lowered onto the Chassis in a tilted or otherwise imperfect orientation, thereby striking the fairing.
Intermodal containers are typically made of steel and are of robust, heavy construction so that they can withstand the rigors of being moved multiple times while securely protecting and supporting the freight that they carry. As a consequence, there is risk of damage to any side fairing mounted on the Chassis should the container be lowered onto the Chassis in any imperfect orientation. Perfect lifting/lower and perfect alignment of the container to the Chassis cannot always be achieved.
SUMMARY OF THE INVENTION
The present invention functions to permit the attachment of fairings or other structures to Chasses, or any trailer wherein the support for the fairing or other structure is exposed to the load to be carried by such trailer, and may be damaged during imperfect loading.
In one embodiment, the intermodal trailer chassis, which comprises a beam and bogie wheels mounted thereon, and which defines a spatial gap forward of the wheels between the bottom of the container and the road surface, has a side fairing panel secured to the Chassis proximate to such gap. The side fairing panel is secured to the Chassis by a bracket comprising a strut having an inner portion and an outer portion, where the inner portion of the strut is rigidly secured to the beam, and the outer portion is rigidly secured to the side fairing panel. The top edge of the side fairing is proximate to the plane defined by the bottom of an intermodal container when such a container is mounted on the Chassis. The inner portion of the strut is rotatably fastened to the outer portion of the strut, so that, in the event that a container is lowered onto the Chassis in a misaligned orientation, the side fairing panel will be displaced away correspondingly, thereby avoiding damage.
In a second embodiment, the intermodal trailer chassis, which comprises a beam and bogie wheels mounted thereon, and which defines a spatial gap forward of the wheels between the bottom of the container and the road surface, has a side fairing panel secured to the Chassis proximate to such gap, wherein the side fairing panel comprises an upper sub-panel have an edge and a lower sub-panel. The edge of the upper sub-panel is proximate to the bottom of the container, and the lower sub-panel of the side fairing panel is secured to the Chassis by a strut having an inner portion and an outer portion. The inner portion of the strut is rigidly secured to the beam, the outer portion is rigidly secured to the side fairing panel, and the upper sub-panel is rotatably or flexibly mounted to the lower sub-panel so that, in the event that a container is lowered onto the Chassis in a misaligned orientation, the upper sub-panel of the side fairing panel will rotate away correspondingly, thereby avoiding damage.
In a further embodiment of the present invention, there is provided a chassis or trailer having one or more generally longitudinal structural beams and bogie wheels attached thereto, either directly or indirectly via a bogie wheel mounting assembly. The longitudinal beam(s) are generally oriented in the direction of travel, and the chassis or trailer when placed on a road surface defining a spatial gap forward of the wheel set between the road surface and the bottom of the trailer or load to be carried by the chassis. The chassis or trailer is provided with a side fairing system comprising a side fairing panel secured to the trailer or chassis proximate to such gap, the side fairing panel having an edge proximate to the bottom of the trailer or the top plane of the chassis where the bottom of an intermodal container would be. The side fairing panel is secured to the trailer or chassis by one or more strut(s) having an inner portion and an outer portion, where the inner portion of each strut is rigidly secured to the trailer or chassis, and the outer portion rigidly secured to the side fairing panel, and the strut is elastic, thereby permitting the side fairing panel to deflect in the vertical direction in response to a correspondingly oriented force component, and then return to its undeflected orientation upon removal of the force component.
In another embodiment, the intermodal trailer chassis, which comprises a beam and bogie wheels mounted thereon, and which defines a spatial gap forward of the wheels between the bottom of the container and the road surface, has a side fairing panel secured to the Chassis proximate to such gap, wherein the side fairing panel comprises an upper sub-panel having an edge and a lower sub-panel. The edge of the upper sub-panel is proximate to the bottom of the container, and the lower sub-panel of the side fairing panel is secured to the trailer chassis by a strut having an inner portion and an outer portion. The inner portion of the strut is rigidly secured to the beam, the outer portion is rigidly secured to the side fairing panel, and the upper sub-panel is made of an elastic material which returns to its original position after impact so that, in the event that a container is lowered onto the Chassis in a tilted orientation, the upper sub-panel of the side fairing panel will bend away correspondingly, thereby avoiding damage.
In a further embodiment, the intermodal trailer chassis, which comprises a beam and bogie wheels mounted thereon, and which defines a spatial gap forward of the wheels between the bottom of the container and the road surface, has a side fairing panel secured to the Chassis proximate to such gap, wherein the side fairing panel comprises an upper sub-panel having an edge and a lower sub-panel. The edge of the upper sub-panel is proximate to the bottom of the container, and the lower sub-panel of the side fairing panel is secured to the Chassis by a strut having an inner portion and an outer portion. The inner portion of the strut is rigidly secured to the beam, the outer portion is rigidly secured to the side fairing panel, and the upper sub-panel is made of a bristle or other flexible multi-part material which returns to its original orientation after impact, so that, in the event that a container is lowered onto the Chassis in a tilted orientation, the upper sub-panel of the side fairing panel will bend away correspondingly, thereby avoiding damage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of an intermodal Chassis with the vehicle side fairing panel comprising the present invention depicted thereon.
FIG. 2 is a planar view of the side fairing panel of the present invention.
FIGS. 3A , 3 B and 3 C depict side views of three different types of pivotable struts used to support the side fairing panel in certain embodiments.
FIGS. 4A , 4 B and 4 C depict schematic side views of three different types of elastic struts used to support the side fairing panel in certain embodiments.
FIGS. 5A , 5 B and 5 C depict side views of three different types of upper sub-panels of the side fairing panel in certain embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 depicts a Chassis 1 , which generally comprises two I-beams 2 approximately twelve inches deep, spaced apart by plural cross members 3 . A dual-axle bogie 4 is positioned toward the rear of Chassis 1 and a square-legged extendible landing gear 5 is positioned toward the front of Chassis 1 , aft of the kingpin to which a heavy duty truck tractor (“Tractor”) can be pivotally secured. Two cross beams 6 are also provided on which a container may rest during transport. FIG. 1 also depicts Landing Gear 5 of Chassis 1 , which permits a Chassis to sit level and to allow elevation of the Chassis so that a Tractor (not shown) can be attached to and detached from a Chassis.
FIG. 1 depicts Chassis 1 with two side fairings 100 as described herein, one for each side of Chassis 1 . The purpose of side fairings 100 is to inhibit air from entering the underside of Chassis 1 , and generally to smooth the flow of air thereby reducing aerodynamic drag. Side fairings 100 can comprise two or more horizontal panels joined together directly or indirectly such that the multiple panels function as a single aerodynamic panel.
Side fairings 100 are generally rectangular planar structures extending in the vertical direction downward to a relatively small distance above the road surface. In one embodiment, approximately 8 inches of clearance is left between the bottoms of panels 100 and the road.
In FIGS. 1 and 2 , side fairing 100 comprises three horizontal sub-panels, namely lower sub-panel 100 A, middle sub-panel 100 B and upper sub-panel 100 C. Each fairing 100 is secured to an I-beam 2 of Chassis 1 by a number of supporting struts 110 . The end of each strut 110 proximate to chassis 1 is rigidly fastened to the I-beam 2 , as by welding, or one or two 90 degree metal angle fasteners, bolted or riveted to the I-beam 2 and the strut 110 , or by other suitable means. The end of each strut 110 proximate to side fairing 100 is secured to middle sub-panel 100 B or to upper sub-panel 100 C, depending upon the embodiment, using comparable means.
As can be seen in FIG. 1 , the struts 110 are cantilevered, such that the load (both weight and torsional) imposed upon them by the mass of side fairing 100 are transferred to the I-beam 2 entirely through the fastening utilized to secure each strut 110 to the I-beam 2 . The side fairing 100 is thereby free-standing, and it is not secured to the underbody of a Truck, which allows a container to be placed on a Chassis freely and quickly, without interference with side fairing 100 .
In certain embodiments of the present invention, described below with reference to FIGS. 3A , 3 B and 3 C, the portions of struts 110 proximate to side fairing 100 are capable of being displaced in the vertical direction in order to allow the fairing 100 to move correspondingly in the event that a container is inadvertently loaded onto Chassis 1 in a misaligned orientation.
Sub-panel 100 A can be rigidly attached to sub-panel 100 B, or the two sub-panels can be made from one piece of planar material, as preferred. Alternatively, sub-panel 100 A can be attached to sub-panel 100 B utilizing rotatable or bendable fastening in the manner described in U.S. Provisional Patent Application No. 61/301,941, filed Feb. 5, 2010 and International Patent Application No. PCT/US11/23728, filed Feb. 4, 2011, the contents of each of which are incorporated herein by reference in regard to that embodiment.
FIG. 3A illustrates one embodiment of strut 110 which permits fairing 100 to be deflected in the vertical direction. In this embodiment, strut 110 comprises a mounting trunion 102 and a pivoting arm 104 . Pivoting arm 104 is secured to trunion 102 with a pivot pin 103 . A biasing means is provided, such as tension spring 105 . Tension spring 105 , which is secured between mounting trunion 102 and pivoting arm 104 , urges arm 104 in the upward direction. Upward displacement is limited by stop pin 106 , or other suitable means. Mounting trunion 102 is rigidly fastened to the I-beam 2 in the manner described above, and rigidly fastened in similar manner to upper sub-panel 100 C (shown in FIG. 3A ) or alternatively, middle sub-panel 100 B. The geometry of pivoting arm 104 , the placement of stop pin 106 and the position where pivoting arm 104 is secured to side fairing 100 are selected so that the top sub-panel of side fairing 100 is approximately adjacent the container bottom.
FIG. 3B illustrates an alternate embodiment of strut 110 which permits fairing 100 to be deflected in the vertical direction. In this embodiment, strut 110 comprises a mounting trunion 102 and a pivoting arm 104 . Pivoting arm 104 is secured to trunion 102 with a pivot pin 103 . FIG. 3B depicts a biasing means, specifically tension arm 107 , which is fabricated from spring steel or the like. Tension arm 107 is rigidly secured to the lower flange of the I-beam by welding, bolting or the like, and urges arm 104 in the upward direction. Upward displacement can be limited by suitable design, such as by use of a stop pin or flange (not shown).
In FIG. 3B , mounting trunion 102 is rigidly fastened to the I-beam 2 in the manner described above, and pivoting arm 104 is rigidly fastened in similar manner to upper sub-panel 100 C (shown in FIG. 3B ) or alternatively, middle sub-panel 100 B. The geometry of pivoting arm 104 , the placement of any element utilized to limit upward displacement, and the position where pivoting arm 104 is secured to side fairing 100 are selected so that the top sub-panel of side fairing 100 is approximately adjacent the container bottom. Optionally, an element to limit upward displacement can be dispensed with, as in the case where the desired vertical portion of side fairing 100 is achieved when tension arm 107 is in an unstressed state. Tension arm 107 can slide along a suitable bearing surface of pivoting arm 104 , as in the case where pivoting arm 104 is a channel section open at the bottom. Alternatively, tension arm 107 can be fastened pivoting arm 104 to enhance its stiffness, as desired.
FIG. 3C illustrates a further alternate embodiment of strut 110 which permits side fairing 100 to be deflected in the vertical direction. In this embodiment, strut 110 comprises a mounting trunion 102 and a pivoting arm 104 . Pivoting arm 104 is secured to trunion 102 with a pivot pin 103 . FIG. 3C depicts a biasing means, specifically tension element 108 , which is fabricated from spring steel or the like. Tension element 108 , which is positioned above pivot pin 103 to span the underside of suitable bearing surfaces of mounting trunion 102 and pivot arm 104 (such as where each is a channel, appropriately oriented, or a box, in cross section), urges pivoting arm 104 in the upward direction. Upward displacement can be limited by suitable design, such as by use of a stop pin or flange (not shown).
In FIG. 3C , mounting trunion 102 is rigidly fastened to the I-beam 2 in the manner described above, and pivoting arm 104 is rigidly fastened in similar manner to upper sub-panel 100 C (shown in FIG. 3C ) or alternatively, middle sub-panel 100 B. The geometry of pivoting arm 104 , the placement of any element utilized to limit upward displacement, and the position where pivoting arm 104 is secured to fairing 100 are selected so that the top sub-panel of side fairing 100 is approximately adjacent the container bottom. Optionally, an element to limit upward displacement can be dispensed with, as in the case where the desired vertical portion of side fairing 100 is achieved when tension element 108 is in an unstressed state.
In the embodiments of FIGS. 3A through 3C , provision of pivoting arms permits side fairing 100 to be deflected in the vertical direction. FIGS. 4A through 4C illustrate three alternative embodiments of struts 110 . In these embodiments, struts 110 are elastic, thereby permitting side fairing 100 to deflect in the vertical direction, if for example side fairing 100 comes in contact with an intermodal chassis being loaded onto the chassis in a misaligned configuration. These elastic struts 110 urge side fairing 100 in an upward direction, so that fairing 100 returns to its pre-contact position after the container is correctly aligned and positioned on the chassis.
In the embodiment illustrated in FIG. 4A , strut 110 comprises one or more strips of spring steel which have been bent, cut and/or assembled to form two approximately straight sections 111 and 112 , with the sections oriented at an appropriate angle, for example 90 degrees as shown. The section 111 of strut 110 is vertically oriented and rigidly fastened to the I-beam 2 using bolts, rivets or the like, and section 112 is horizontally oriented and fastened to fairing 100 . The rigidity and vertical displacement of the horizontal section 112 of the strut can be controlled by suitable selection the thickness and stiffness of the spring steel, and by appropriate tempering and quenching treatments. In addition to spring steel, the strut 110 can also be fabricated from composites, plastics and other materials whose elastic characteristics can be managed through design and material selection.
In the embodiment illustrated in FIG. 4B , strut 110 comprises one or more strips of spring steel which have been bent, cut and/or fastened to form three approximately straight sections 113 , 114 and 115 in the shape illustrated. Section 113 of strut 110 is vertically oriented and rigidly fastened to the I-beam 2 using bolts, rivets or the like, section 115 is horizontally oriented and fastened to fairing 100 , and medial section 114 is diagonally oriented and joins sections 113 and 115 . The rigidity and vertical displacement of the horizontal section 115 of the strut 110 can be controlled by appropriate selection of the thickness and stiffness of the spring steel, the angles of the bends, and by appropriate tempering and quenching treatments. In addition to spring steel, the strut can also be fabricated from composites, plastics and other materials whose elastic characteristics can be managed through design and material selection.
In the embodiment illustrated in FIG. 4C , strut 110 comprises one or more strips of spring steel which have been bent, cut and/or fastened to form an arcuate shape, as illustrated. Strut 110 terminates in a vertical portion 116 , which is rigidly fastened to an I-beam 2 using bolts, rivets or the like, and terminates in a horizontal portion 117 , which is fastened to fairing 100 . The rigidity and vertical displacement of the horizontal section of the strut can be controlled via the thickness and stiffness of the spring steel, and the angles of the bends. In addition to spring steel, the strut 110 depicted in FIG. 4C can also be fabricated from composites, plastics and other materials whose elastic characteristics can be managed through design and material selection.
FIG. 5A illustrates an embodiment of the present invention, in which middle sub-panel 100 B is rotatably attached to upper sub-panel 100 C of panel 100 by means of, for example, a stainless steel piano hinge 41 . As an alternative to rotatable attachment, the middle sub-panel 100 B is flexibly attached to upper sub-panel 100 C of panel 100 by means of, for example, a resilient strip or strips of flexible plastic, rubber or the like spanning the junction between the sub-panels and secured to the sub-panels proximate the junction by suitable means, such as adhesive, fasteners with load distribution plates, and the like. One or more biasing means, such as torsion springs 42 , can be utilized to urge sub-panel 100 C toward its proper vertical orientation, optionally using one or more stop flanges or the like (not shown) according to the needs of the particular design, to limit the rotation of sub-panel 100 C. An angled strip, made of plastic, metal, or other appropriate material is secured to the top portion of sub-panel 100 C to insure that the lowering of a container in the vertical direction will cause sub-panel 100 C to rotate about pin 44 of piano hinge 41 .
FIG. 5B illustrates a further embodiment of the present invention, in which upper sub-panel 100 C of panel 100 is made of a flexible material that is rigidly secured to middle sub-panel 100 B. The flexible material can be a flexible rubber or rubber-like material, or any other elastic material which returns to its original position after impact, for example, a TPV material. Sub-panel 100 C can be removably mounted with rivets, bolts or the like to permit easy replacement.
FIG. 5C illustrates yet another embodiment of the present invention, in which upper sub-panel 100 C of panel 100 is made of a vertically oriented flexible bristle material, or other flexible multi-part material, which is rigidly secured to middle sub-panel 100 B.
By utilizing the embodiments of FIG. 5A , 5 B or 5 C the struts 110 can be rigidly attached to Trailer chassis 1 , although the FIGS. 5A-5C embodiments optionally can be combined with any of the embodiments of FIGS. 3A-3C , according to preference.
The sub-panels 100 A and 100 B can be fabricated from sheet steel, aluminum, plastic, or other panel material, and fastened to a structural frame of steel, aluminum, plastic or other stock material to enhance rigidity. However, it is preferred that sub-panels 100 A and 100 B be fabricated of a plastic having gas injected into it when molten, such as thermoplastic olefin elastomer. Such a plastic will have less weight and a lower cost than a comparable all solid plastic. This plastic will also naturally tend to shed water and minimize snow/ice build-up during inclement winter conditions. In the embodiments of FIGS. 3A , 3 B, 3 c , and 5 A, upper sub-panel 100 c can be fabricated of like material.
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A trailer or intermodal trailer chassis having a vehicle side fairing that accommodates, without being damaged, a container or other object lowered onto the trailer or intermodal chassis in a misaligned orientation.
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[0001] This application claims benefit of U.S. Provisional Application No. 60/275,378, filed Mar. 13, 2001, which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a device to take a spherical or hemispherical panoramic image from a specific point in the air, and more particularly, to a simple device with no moving parts that rotates about two axes to scan the imaging device over the ground in two axes, such that the images can be put together to create a panoramic image.
BACKGROUND OF THE INVENTION
[0003] A person on the ground, such as a soldier, may need to know what is in the immediately surrounding area. Reconnaissance of an area can often be efficiently done from the air. (For example, it has been reported that tanks operating in urban environments require helicopter support before turning a street corner, to detect anti-tank weapons). However, manned aircraft are expensive, not always readily available, may not have access to the area to be looked at and a direct link to the person at the site is not always available. Satellites are only available a few times each day at predictable times, the resolution of commercial imaging satellites is not very good, and again, the ability to get the information to the person at the site is limited. Unmanned aircraft flown by the person at the site are large, expensive or difficult to operate, and require an open area for launch and recovery. Recovery is necessary because of the expense involved. Larger unmanned aircraft flown from fixed bases have many of the same problems as manned aircraft. Balloons are time consuming to inflate and fly, and depend too much on calm wind conditions.
[0004] Aircraft or satellites over-flying an area typically take vertical photographs of the earth directly below the vehicle, or panoramic photographs that extend out to either side. A large amount of ground can then be covered by flying the vehicle in a forward direction and combining the photographs into a long strip.
[0005] These methods are expensive, and not in the direct control of the person requiring the photographs, so there is an inherent time delay in getting the images to him.
[0006] Systems that are portable, and can be carried into the field, require input from the user to aim the imaging sensor at targets of interest. This is also time consuming, and involves some level of skill and practice to be able to control the imaging device accurately.
[0007] A device that loiters above the operator may also give away his position if it is detected. The chances of detection go up with time.
[0008] A lightweight, man-portable device that automatically gives the person an immediate and detailed view of the entire surrounding area, centered on his position is not available.
SUMMARY OF THE INVENTION
[0009] An object of the invention is to provide the user immediate access to detailed aerial photographs of the entire surrounding area out to a certain radius.
[0010] Another object of the invention is to provide a device that gathers this information with an imaging device from a substantially stationary point in the air above the operator.
[0011] Another object of the invention is to provide a device that can generate its pictures with no control from the ground, or user input, once it has been put into the air. To achieve this objective, the vehicle system of the invention gathers a series of images by rotating the imager in a predictable pattern along two separate axes that covers a spherical area, or a portion of a sphere. Optionally, if the device loiters in the air, it may be controlled to further examine an object of interest discovered in the initial set of images.
[0012] In some aspects, the invention provides a device that is spun up to the scanning speed along the first axis using fins that impart a torque about the roll axis as it moves through the air. The imaging device may be fixed with respect to the body of the device, with the optical axis perpendicular to the roll axis. To prevent blurred images, the shutter speed, or data collection time of the imager, is short enough to be considered insignificant compared to the angular rotation rate. The second scanning axis is provided by the device pitching over at the peak of a steep ballistic trajectory.
[0013] Another object of the invention is to provide a sensor that can be used to measure the orientation of the imaging device to assist in orienting the information from the imager. Alternately the imaging device may gather this information without scanning, using a wide angle or fisheye lens.
[0014] Another object of the invention is to provide a system where the data from the imaging device is stored or transmitted down to the operator and the operator can map all of the imaging data onto a spherical surface using a computer. The computer may then display the data on a display, such as the screen of a laptop computer, and allow the user to pan, zoom or perform other operations using the data, including, but not limited to object recognition, motion detection, range finding and geo-location.
[0015] As used herein, an “image” or “imagery data” is a collection of sensor data where each datum is associated with a relative location (e.g., a rectangular array of pixels). An “imager” or an “imaging device” is any sensor that collects imagery data.
[0016] As used herein, a “gun” includes any member of the class of small arms and light weapons, as defined by the UN Panel of Experts on Small Arms and approved by the United Nations General Assembly in 1997.
[0017] As used herein, a “data transmitter” includes wireless, wired, fiber optic, and other equivalent systems for transferring data from one location to another, although wireless systems are preferred in most embodiments of the invention.
[0018] As used herein, a “portable” vehicle is one that can be transported on a vehicle such as a light truck or a tank. A “man-portable” vehicle is one that can be carried by one to four men, and preferably one that can be carried by a single man.
BRIEF DESCRIPTION OF THE DRAWING
[0019] The invention is described with reference to the several figures of the drawing, in which,
[0020] [0020]FIG. 1 shows an overview of one embodiment of the system including the aerial vehicle, the operator and the ground system;
[0021] [0021]FIG. 2 shows a cutaway detail of the aerial vehicle of FIG. 1;
[0022] [0022]FIG. 3 shows the flight path of the vehicle and the scan pattern used to cover the ground in one embodiment of the invention; and
[0023] [0023]FIG. 4 shows a scan pattern for a horizon sensor to obtain roll and pitch information from a single sensor.
DETAILED DESCRIPTION
[0024] [0024]FIG. 1 shows a device 1 according to the invention launched in a ballistic trajectory, from a small, portable launch pad 6 . The images from the device 1 are transmitted to the operator with a portable ground station 5 where they are received by the receiver 3 using the antenna 2 , and transferred to the portable computer 4 . The computer arranges the images in a complete panorama, covering the entire area as seen by the flight vehicle 1 at the top of its trajectory.
[0025] [0025]FIG. 2 shows a cut away detail of one flight vehicle according to the invention. It is launched into the air using a small solid fueled rocket motor 9 . Those of ordinary skill in the art will appreciate that the ideal height of launch will depend on the area to be viewed and the quality of the imager, and may range from as low as ten feet to as high as 30,000 feet, or even up to 100,000 feet or more for some vehicles. The best propulsion device will depend upon the desired height, and possibly on other factors such as radar visibility and noise. A great many propulsion devices are possible, such as motors and engines, springs, explosives, electromagnetic launchers (e.g., rail guns), electrostatic launchers, compressed gas launchers, mechanical launchers (including handheld mechanical launchers such as slings), or pressurized fluids (such as a “water rocket”). If only a modest area is to be imaged, the device can simply be thrown in the air.
[0026] The size of the vehicle will depend on the sensors on board, the desired height of the flight path, the launch method and other considerations. It is preferred that the vehicle be man-portable, and preferably that it weigh under 5 pounds, if it is to be used by soldiers in the field. It is also preferred that the vehicle be small (e.g., 6-12 inches in length) for this type of application, but larger vehicles (e.g., five feet or more) are also within the scope of the invention.
[0027] As the vehicle shown in FIG. 1 ascends, the fins 7 , which are canted at an angle, cause the airframe 8 to rotate about its roll axis. In the embodiment shown, the fins 7 are fixed, but deployable and/or adaptable fins (e.g., fins that change angle to maintain a specific roll rate) may also be used. The imager 10 has a lens with an optical axis perpendicular to the airframe's 8 roll axis, and looks out a port in the side of the airframe. An image is captured by the imager 10 , and is transmitted to the ground station using transmitter 11 . Both the imager and transmitter are powered by the power source 12 , which could be a battery, capacitor or other power source. A directional light sensor 13 is tilted at an angle that is between the roll axis and perpendicular to said axis. The purpose of the light sensor 13 is to observe the horizon passing as the vehicle rolls. Since the light sensor has an angular component in the roll plane and the pitch plane, it can obtain data on the roll rate and the pitch rate at the top of the flight path. This is explained in more detail in FIG. 4.
[0028] In the embodiment shown in FIG. 2, the imager is a visible light device such as a linear array imager, a rectangular CCD, or the like. Other sensors, such as infrared sensors, chemical sensors, biological sensors, radar, sonar, or other sensors may be appropriate for some applications. Those of ordinary skill in the art will see how to select an appropriate sensor for a given embodiment. In addition, it may be desirable in many cases to include multiple sensors (e.g., a chemical or biological “sniffer” may be mounted on the vehicle in addition to a light camera), not all of which need generate locationally specified image data.
[0029] [0029]FIG. 3 shows the aerial vehicle 14 flying along the ballistic flight-path 15 . As the airframe 8 spins along the roll axis 20 , the imaging device's 10 field of view 16 is swept along the ground 17 in a plane 18 perpendicular to the aerial vehicle's flight path. As the aerial vehicle 14 arcs over at the peak of its ballistic trajectory 15 , the rotation along the pitch axis 21 causes the imaging device to sweep out incrementally different paths along the ground with each sweep intercepting the horizon 19 at a point perpendicular to the aerial vehicle's flight path 15 at its apogee. In an aerodynamic vehicle such as the one shown in FIG. 3, the center of mass of the vehicle should be placed forward of the center of pressure, so that the vehicle will arc over the ground and sweep through a large enough pitch range. In some preferred embodiments, the flight path and roll rate are selected so that images can be captured in all directions over a very short flight distance at apogee, so that image data is collected from a substantially stationary point.
[0030] [0030]FIG. 4 shows how the light sensor 13 is used to determine the orientation of the vehicle when each image is taken by the imager 10 . As the vehicle 30 rotates about its roll axis 25 , the directional light sensor's field of view 23 traces out a circle 28 . When the light sensor's field of view 23 crosses the horizon at 22 , it detects a different light level. The frequency of change of this difference in light level can be used to determine the vehicle's roll rate, and by interpolating between sequential horizon crossings, the imager's roll position can be determined. As the vehicle 30 arcs over in the pitch direction 26 , the circles traced out by the light sensor 27 , 28 will intersect the horizon at different points. The fraction of the circle above or below the horizon can be used to determine the pitch angle, and interpolating between two different circles can be used to find the pitch rate and angle at any moment in time. The data from the light sensor is transmitted to the ground using the audio channel of the TV transmitter 11 , and saved on the computer 4 on the ground to be used to reconstruct the flight path.
[0031] As each image or datum is transmitted from the imager 10 to the ground station, the computer 4 places the data in the appropriate place in a spherical data set by using the position information interpolated from the light sensor 13 data. If the light sensor is not present, the same flight information can be obtained from the images themselves. The roll rate is determined by the frequency of the horizon passing through the images, and the pitch is obtained from the angle of the horizon to that of the imager. (In appropriate situations, features other than the horizon may be used in the same way to determine roll and pitch). Orientation may also be measured in a variety of other ways, such as with an inertial device such as a gyroscope; using a wide-angle lens to create a lower resolution, wide-area view with which images may be correlated; with a magnetic sensor such as a compass; using an altimeter and/or a time-of-flight monitor to infer the ballistic trajectory; by measuring the polarization of ambient light to detect the position of the sun; or by using a light intensity sensor to detect the sun (or another distinctive light source such as the moon, the stars, or artificial lighting) directly.
[0032] After the imager 10 has been swept over all of the ground visible from the top of the flight path, the vehicle may be recovered by parachute, or allowed to crash to the ground (e.g., if it is disposable). In preferred embodiments of the invention, the images collected by the vehicle are transmitted by a data transmitter to a ground station. The ground station may be, for example, a laptop computer. If the vehicle is recoverable, it can be “plugged in” to the ground station to download data, or it may transmit data to the ground station during flight. Disposable vehicles will generally transmit data to the ground system during flight, for example by wireless transmission or via a tether wire.
[0033] The transmitted data set can then be displayed on a computer screen. In preferred embodiments, the operator can zoom and pan around the image, or perform other manipulations such as overlaying the images on a map. Since a typical data set covers all or a significant portion of a sphere, the image can even be viewed in a three-dimensional virtual reality system.
[0034] It will often be desired to determine the absolute location, as well as the orientation, of images captured by the system. This may be done, for example, by placing a Global Positioning System (GPS) receiver on the vehicle. The GPS receiver may also be used to orient the images, since the position of the vehicle can be determined with high accuracy. The GPS data is preferably used to determine the exact trajectory of the vehicle, which is combined with roll rate data measured by one of the other means described above to place images. The trajectory can also be measured by knowing the initial launch point and obtaining directional information from the vehicle or launcher, for example by using a magnetic compass. Location may also be determined by manual or automatic matching of the image with maps, survey photos, or other recorded information about the area. If the location of the launch point and the orientation of launch are known, these data can be used to project the trajectory of the vehicle to determine the location of the image.
[0035] One advantage of this embodiment of the invention is that the vehicle should be very difficult to detect. It is small, quiet, and is only in the air for a matter of seconds. This invention is low cost, can be disposable, and obtains a single set of images per flight. It is small enough that the operator could carry several expendable flight vehicles for use as needs dictate.
[0036] Other solutions to obtaining biaxial scans of the imaging device are also contemplated within the scope of the invention. Imagers may be gimbaled in one or two axes on the launch vehicle, instead of using roll and pitch to scan the imager. Gimbaled systems may deploy parachutes, collecting data while the vehicle descends, for example. “Loitering” systems may also be used with gimbaled cameras. In such systems, the operator may be able to override the scanning function of the imager in order to focus on particular areas of interest.
[0037] In yet another useful embodiment of the invention, a ballistic launch vehicle can be launched over a feature of interest (such as a building), and images collected from the full arc of the ballistic trajectory can be used to create a three-dimensional model of the overflight area.
[0038] Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.
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An imaging device that gives a ground based user immediate access to a detailed aerial photograph of the entire area for a given radius about his present position. The device can be launched into the air, and rotates in a predictable pattern to scan an imager over every point of the ground, from a vantage point high in the air. These pictures can be stored or transmitted to the ground and assembled on a computer to form a spherical picture of everything surrounding the imaging device in the air.
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FEDERAL INTEREST STATEMENT
The invention described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and system for determining when a projectile reaches a desired Height Of Burst (HOB) over a target based solely upon the time at which the projectile reaches or passes through the apogee or apex of its trajectory.
2. Description of Related Art
There are many types of projectiles that are designed to perform a function, such as detonation, at an optimal Height Of Burst (HOB) over a target. For example, an illumination round is designed to deploy a flare to spot enemy targets at night. Similarly, some smoke rounds are designed to burst at a specified HOB in order to obtain optimal dispersion of the smoke cloud over the target.
According to the prior art, a typical time fuse is used to function, i.e., detonate, the projectile when it reaches the desired HOB. A fairly complex set of parameters have to be entered into the system in order to accurately detonate the projectile at the desired HOB. First, the locations of the weapon and the target are required. Then a ballistics solution is computed to determine the angle it should be fired at; the velocity it should be fired at; and the time of flight at which the projectile will reach the desired HOB over the target. Other variables that affect the accuracy of this ballistics solution include meteorological conditions and propellant temperature. The complexity of prior art solutions increases the chances of error. Clearly a simpler and more robust method and system for determining accurately HOB over target is desired. It was in the context of the foregoing prior art that the present invention arose.
SUMMARY OF THE INVENTION
Basically described, the invention comprises a method and system for determining the time at which a projectile reaches a desired HOB over target calculated solely by the time t a at which the projectile reaches or passes through its apogee during its trajectory. This principle can be used to improve the design of existing fuses or to design new improved fuses. The present invention depends, in part, upon the realization that the time t HOB can be determined substantially solely from the time to apogee t a independent of firing angle. Using that insight there are several different ways of determining the time to t HOB . According to one embodiment of the invention, the down leg time can be determined solely as a percentage of the up leg time t a . Accordingly to another, preferred embodiment of the invention, the optimal t HOB can be algebraically derived. These features can be further understood by reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a typical projectile path illustrating the time of the projectile to apogee t a and the time of the projectile to burst t HOB .
FIG. 2 illustrates the fact that changes of the firing angle do not substantially affect the Height Of Burst according to the present invention.
FIG. 3 is a chart illustrating the altitude of projectile when the down leg time N % is a percentage of the up leg time t a and wherein N % is 70%, 80% and 90%.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
During the course of this description, like letters are used to indicate like elements according to the different figures that illustrate the invention.
FIG. 1 illustrates a typical projectile flight. Initially the projectile is launched from a weapon W at a specific location. It climbs to an apogee or apex at a point t a and then descends to the point of bursting at a time t HOB at a Height Of Burst (HOB) above the target X. Part of the basic insight of the present invention is the fact that the time to HOB (t HOB ) can be determined accurately merely by knowing the time to apogee (t a ) regardless of the firing angle of the Projectile. As shown in FIG. 2 , a pair of projectiles P 1 and P 2 , respectively reach their apogees at t a1 and t a2 , respectively. Based upon that information alone the time to Height Of Burst (t HOB ) can be calculated respectively above targets X 1 and X 2 wherein the HOB is identical for both projectiles P 1 and P 2 . This functionality can be programmed into the fuse employed by projectiles P 1 and P 2 .
Specifically, the fuse can determine the time when the projectile will reach a specified Height Of Burst (t HOB ), based on measuring the time it took to reach apogee (t a ). A timer in the fuse is initiated as soon as the projectile is fired from the weapon. A sensor is used to determine when the projectile reaches apogee. Electronics then uses an algorithm to calculate the time at which the projectile will reach the desired HOB, based on the flight time between launch from weapon W and apogee (t a ). The fuse arms and functions the projectile when t=t HOB .
The foregoing has the following benefits. Using t HOB =f(t a ) to determine when the projectile should function, makes the HOB totally independent of factors such as the angle at which the weapon is fired, launch velocity, time of flight, propellant temperature, meteorological conditions, etc. Even if the projectile is fired at a different angle and with a different velocity, it will still function at the same HOB. The only information required to determine an HOB setting is the difference in altitudes between the weapon W and target locations X, and X 2 .
Eliminating these sources of variability and errors can improve the accuracy, reliability, predictability, consistency and flexibility of fire control. The firing crew can even adjust fire to get the projectile closer to the target and these adjustments will not affect the HOB.
There are general methods or algorithms that can be used to determine the time at which the projectile will reach a desired HOB, based on the time it took to reach apogee (t a ). The best solution for any specific type of projectile depends on the accuracy that is required and the cost that can be afforded. Two representative methods are described below.
Method 1—Projectile Motion Equations
Elementary physics provides projectile motion equations for the ideal case of a point mass moving through a vacuum. Algebraic manipulation of these equations provides an empirical relationship between the time to apogee (t a ) and time to any desired HOB (t HOB ):
t HOB =t a +√{square root over ( t a 2 −2×HOB/ g )}+ C
where g=9.81 m/sec 2 =32.2 ft/sec 2 and C=correction factor
Therefore, when the projectile P is fired, the fuse measures the time to apogee (t a ) and plugs this into an equation, to calculate the time when the projectile P will arrive at the desired HOB (t HOB ).
These calculations do not account for aerodynamic effects that the projectile experiences during flight, such as drag. Therefore, the t HOB calculated by this method will always be less than the actual time at which the projectile will reach the desired HOB. For example, the actual time to reach the desired HOB at minimum range may be 0.5 seconds later than the time calculated by the method above; and the time to reach HOB at the maximum range may be 1.5 seconds later. For this type of projectile, a correction factor of 1 second can be added to the equation above. This would assure that the calculated valuation of t HOB is always with +/−0.5 seconds of the actual time of HOB.
This algorithm can be refined, by selecting a more accurate correction factor based on the time to apogee (t a ). For example, the correction factor can be selected from a reference table, such as the following:
If t a >12 seconds then C=1.0 sec If 12 sec>t a >9 seconds then C=0.75 sec If 9 sec>t a >7 seconds then C=0.5 sec If t a <7 seconds then there may be a malfunction and the fuse should not function the round.
The accuracy of this type of algorithm can be increased by increasing the number of time segments. Curve fitting techniques can also be used to determine the coefficients of a polynomial equation that provides a more accurate or at least “smoother” calculation for the correction factor (C) as a function of t a , such as:
C=a+b ( t a )+ c ( t a ) 2 +d ( t a ) 3 + . . .
where a, b, c, d . . . are the polynomial coefficients
A further improvement to this type of algorithm would be to program the fuse with a trajectory simulation model that can more accurately represent the true trajectory of the projectile during flight. Therefore, when the projectile is fired, the fuse would measure the actual time to reach apogee. An algorithm could be based on fundamental equations of motion or an advanced trajectory simulation model to calculate t HOB . The fuse arms and functions the projectile when t=t HOB .
Method 2—Downleg Time=N % of Upleg Time
This method is based on relating the upleg time and downleg time of the projectile's flight. The upleg time is the time from launch to apogee (t a ). The downleg time is the time from apogee to the desired HOB. For example, a suitable HOB may be obtained by simply functioning the projectile when the downleg time is 90% of the upleg time. This would assure that the projectile always functions in less time than it took to reach apogee.
The chart shown in FIG. 3 illustrates the altitude of a projectile when N % is 70%, 80% and 90%. For example, when the projectile is fired at charge 4 (max velocity), then the altitude it reaches at apogee is about 4,000 meters. If the downleg time is 70% of the upleg time, then the HOB of the projectile will be about 2,400 meters. Similarly, at 80% the HOB will be 1,700 meters and at 90% it will be 1,200 meters.
If the fuse algorithm were set to always function the projectile when the downleg time is 90% of the upleg time, the resulting HOB would vary from 1,200 meters at charge 4 to nearly ground level at charge 0 . To reduce this variation, the fuse algorithm can reference a table of N % values, such as the following:
If t a >12 seconds then downleg time=90% of t a If 12 sec>t a >9 seconds then downleg time=70% of t a If 9 sec>t a >7 seconds then downleg time=10% of t a If t a <7 seconds then there may be a malfunction and the fuse should not function the round.
The accuracy of this type of algorithm can be increased by increasing the number of time segments. Curve fitting techniques can also be used to determine the coefficients of a polynomial equation that provides a more accurate or at least “smoother” calculation for the correction factor (N) as function Of t a , such as:
N=a+b ( t a )+ c ( t a ) 2 +d ( t a ) 3 + . . .
where a, b, c, d . . . are the polynomial coefficients
Therefore, when the projectile is fired, the fuse would measure the actual time to reach apogee. The algorithm would determine the correct value of N %, based on the time measured for t a and then calculate t HOB . The fuse arms and functions the projectile when t=t HOB .
Sensors for Detecting Apogee
There are a growing number of sensors that can be used to detect when a projectile has reached apogee or determine when the projectile had passed through apogee. The following is a short summary of some of these sensor candidates. The best solution will depend on factors such as the accuracy required for the specific application; the profile of the trajectory; the cost that can be afforded; and the volume that is available to accommodate the sensor. Other considerations for sensor selection include the environments that it must be able to withstand when the projectile is fired (e.g.; axial acceleration, rotational acceleration); and atmospheric conditions (e.g.; rain, snow, temperature extremes, etc.).
For some applications, a suitable accelerometer may be used for detecting apogee. The accelerometer must withstand significant acceleration during launch. It may be able to sense the drag forces during flight. The projectile may become weightless at apogee. A gyroscope may be used to sense when the projectile transitions from a “nose up” to a “nose down” orientation. If the projectile reaches sufficient altitudes, then a barometric sensor may be used to determine when apogee was reached.
A velocity sensor can be used to detect when the projectile is launched and when it passes through its apogee. A pitot tube can be exposed to the air stream during flight for such a purpose. A small turbine may also be employed. As airflow passes through the turbine, the speed or output of the turbine can be used to detect when the projectile passes through its apogee.
Other more advanced sensor technologies include a global positioning sensor (GPS), an integrated inertial measuring unit; or a micro electronic mechanism (MEM). In some cases, additional electronics may be required to record the sensor measurement during flight and then extrapolate back to determine when the projectile actually passed through apogee.
Preferred Method
An electronic time fuse can be designed that is powered by a turbo alternator. When that projectile is fired, the turbo alternator will begin generating electricity to automatically power up the fuse. The airflow through the turbo alternator will decrease as the projectile approaches apogee and then increase again after apogee. Electronics will monitor the performance of the turbo alternator to determine the time at which the projectile passed through its apogee (t a ). Then the fuse will use this value of t a , that is measured during the actual flight of the projectile, to compute the time to HOB (t HOB ) with the following relationship:
t HOB =t a +√{square root over ( t a 2 −2×HOB/ g )}+ C
The fuse arms and functions the projectile when t=t HOB .
In summary, this invention is for determining the time at which a projectile will reach a desired HOB over a target (t HOB ), based on the actual measured time, for it to reach its apogee during flight (t a ). This can be accomplished by designing an electronic time fuse that is powered by a turbo alternator. When the projectile is fired, the turbo alternator will begin generating electricity to automatically power up the fuse. The airflow through the turbo alternator will decrease as the projectile approaches apogee and then increase again after apogee. Electronics will monitor the performance of the turbo alternator to determine the time at which the projectile passed through its apogee (t a ). Then the fuse will use this value of t a , that is measured during the actual flight of the projectile, to compute the time to HOB (t HOB ) with the following relationship:
t HOB =t a +√{square root over ( t a 2 −2×HOB/ g )}+ C
The fuse arms and functions the projectile when t=t HOB .
This makes the HOB totally independent of factors such as the angle at which the weapon is fired, launch velocity, time of flight, propellant temperatures, meteorological conditions, etc. Eliminating these sources of variability and errors will improve the accuracy, reliability, predictability and consistency of the projectile function. The only information required to determine an HOB setting is the difference in altitudes between the weapon and target locations. Even if the projectile is fired at a different angle and different velocity, it will still function at the same HOB. The firing crew can adjust fire to get the projectile closer to the target, and these adjustments will not affect the HOB. This will improve the flexibility of fire control for the projectile.
While the invention has been described with reference to the preferred embodiment thereof, it will be appreciated by those of ordinary skill in the art that various modifications can be made to the method and system described without department from the spirit of the invention as a whole.
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A method and system optimally determines a desired Height of Burst (HOB) over a target based solely upon the time at which the projectile reached or passes through the apogee or apex of its trajectory (t a ). There are several modes of implementation. According to one mode, the downleg is determined as a percentage of the upleg. According to another mode, the time to Height Of Burst (t HOB ) is calculated algebraically based substantially solely upon the time to height of apogee t a .
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FIELD OF THE INVENTION
The present invention relates to an apparatus and process for forming meltblown fibers. More specifically, the present invention relates to an apparatus and process for forming meltblown fibers utilizing an extended jet thermal core produced by entraining hot air at the point of jet thermal core formation.
BACKGROUND OF THE INVENTION
Meltblown fibers are fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging, usually hot and high velocity, gas, e.g. air, streams to attenuate the filaments of molten thermoplastic material and form fibers. During the meltblowing process, the diameter of the molten filaments are reduced by the drawing air to a desired size. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. Nos. 3,849,241 to Buntin et al., 4,526,733 to Lau, and 5,160,746 to Dodge, II et al., all of which are hereby incorporated herein by this reference. Meltblown fibers may be continuous or discontinuous and are generally smaller than ten microns in average diameter.
In a conventional meltblowing process, molten polymer is provided to a die that is disposed between a pair of air plates that form a primary air nozzle. Standard meltblown equipment includes a die tip with a single row of capillaries along a knife edge. Typical die tips have approximately 30 capillary exit holes per linear inch of die width. The die tip is typically a 60° wedge-shaped block converging at the knife edge at the point where the capillaries are located. The air plates in many known meltblowing nozzles are mounted in a recessed configuration such that the tip of the die is set back from the primary air nozzle. However, air plates in some nozzles are mounted in a flush configuration where the air plate ends are in the same horizontal plane as the die tip; in other nozzles the die tip is in a protruding or “stick-out” configuration so that the tip of the die extends past the ends of the air plates. Moreover, as disclosed in U.S. Pat. No. 5,160,746 to Dodge II et al., more than one air flow stream can be provided for use in the nozzle.
In some known configurations of meltblowing nozzles, hot air is provided through the primary air nozzle formed on each side of the die tip. The hot air heats the die and thus prevents the die from freezing as the molten polymer exits and cools. In this way the die is prevented from becoming clogged with solidifying polymer. The hot air also draws, or attenuates, the melt into fibers. Other schemes for preventing freezing of the die, such as that detailed in U.S. Pat. No. 5,196,207 to Koenig, using heated gas to maintain polymer temperature in the reservoir, are also known. Secondary, or quenching, air at temperatures above ambient is known to be provided through the die head, as in U.S. Pat. No. 6,001,303 to Haynes et al.
Primary hot air flow rates typically range from about 20 to 24 standard cubic feet per minute per inch of die width (SCFM/in).
Primary air pressure typically ranges from 5 to 10 pounds per square inch gauge (psig) at a point in the die head just prior to exit. Primary air temperature typically ranges from 450° to 600° Fahrenheit (F), but temperatures of 750° F. are not uncommon. The particular temperature of the primary hot air flow will depend on the particular polymer being drawn as well as other characteristics desired in the meltblown web.
Expressed in terms of the amount of polymer material flowing per inch of the die per unit of time, polymer throughput is typically 0.5 to 1.25 grams per hole per minute (ghm). Thus, for a die having 30 holes per inch, polymer throughput is typically about 2 to 5 lbs/inch/hour (PIH).
Moreover, in order to form meltblown fibers from an input of about five pounds per inch per hour of the polymer melt, about one hundred pounds per inch per hour of hot air is required to draw or attenuate the melt into discrete fibers. This drawing air must be heated to a temperature on the order of 400-600° F. in order to maintain proper heat to the die tip.
Because such high temperatures must be used, a substantial amount of heat is typically removed from the fibers in order to quench, or solidify, the fibers leaving the die orifice. Cold gases, such as air, have been used to accelerate cooling and solidification of the meltblown fibers. In particular, in U.S. Pat. No. 5,075,068 to Milligan et al. and U.S. Pat. No. 5,080,569 to Gubernick et al., secondary air flowing in a cross-flow perpendicular, or 90°, direction relative to the direction of fiber elongation, has been used to quench meltblown fibers and produce smaller diameter fibers. In addition, U.S. Pat. No. 5,607,701 to Allen et al., uses a cooler pressurized quench air that fills chamber 71 and results in faster cooling and solidification of the fibers. In U.S. Pat. No. 4,112,159 to Pall, a cold air flow is used to attenuate the fibers when it is desired to decrease the attenuation of the fibers.
Through the control of air and die tip temperatures, air pressure, and polymer feed rate, the diameter of the fiber formed during the meltblown process may be regulated. For example, typical meltblown polypropylene fibers have a diameter of 3 to 4 microns.
After cooling, the fibers are collected to form a nonwoven web. In particular, the fibers are collected on a forming web that comprises a moving mesh screen or belt located below the die tip. In order to provide enough space beneath the die tip for fiber forming, attenuation and cooling, forming distances of at least about 8 to 12 inches between the polymer die tip and the top of the mesh screen are required in the typical meltblowing process.
However, forming distances as low as 4 inches are described in U.S. Pat. No. 4,526,733 to Lau (hereafter the Lau patent). As described in Example 3 of the Lau patent, the shorter forming distances are achieved with attenuating air flows of at least 100° F. cooler than the temperature of the molten polymer. For example, Lau discloses the use of attenuating air at 150° F. for polypropylene melt at a temperature of 511° F. to allow a forming distance between die tip and forming belt of 4 inches. The Lau patent incorporates passive air gaps 36 (shown in FIG. 4 of Lau) to insulate the die tip.
Past efforts have largely focused on improved quenching in these short distances, where it can take as little as 1.3 ms for the meltblown extrudate to travel from the die to the collecting wire. The present invention approaches the problem of meltblown fiber formation from the opposite direction by seeking to increase the dwell time of the extrudate within the hot jet thermal core in order to further attenuate the fibers and also to allow the fibers to be formed from lower viscosity resins than were previously practical.
SUMMARY OF THE INVENTION
The present invention provides a method for producing super fine meltblown fibers by increasing the length of the meltblown jet thermal core to increase the dwell time of the extruded thermoplastic polymer within the jet thermal core. Through use of the method it is practical to use low viscosity resins and further to provide the resultant meltblown nonwovens with superior barrier properties to the passage of fluids and particularly gases.
The apparatus for practicing the method is both economical and easily retrofitted to existing meltblown fiber apparatus.
In essence, an entrainment duct or heat source is placed at the point of formation of the jet thermal core (hereinafter sometimes referred to synonymously as “jet”) and used to shroud the jet area from cold air and entrain warm air into the jet thereby lengthening it. Thus, the jet will provide higher temperatures over a longer distance and time for the extruded fibers and maintain a low melt viscosity during the fibers' passage through the fiber attenuation zone.
Through the use of the lengthened jet, lower viscosity resins than heretofore practical may be used to form the fibers. Further, the resultant web of fibers made according to the present invention will have superior barrier properties to the passage of air and other fluids making a useful fabric for either barrier or filtration applications. Also, due to increased jet length, polymer additives may tend to bloom towards the surface of the fibers. Practical applications of fabric made according to the present invention may include barrier fabrics such as surgical gowns or the like and filtration materials.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of this invention will be better understood from the following detailed description taken in conjunction with the drawings wherein:
FIG. 1 is a schematic representation of a perspective view of a known meltblown fiber forming apparatus suitable for use in conjunction with the present invention.
FIG. 2 is a schematic representation of a cross sectional perspective view of the fiber forming portions of a meltblown die in conjunction with a hot air entrainment duct according to an embodiment of the present invention.
FIG. 3 is a cross sectional elevation similar to FIG. 1 and showing the lengthening effect of the present invention on the jet thermal core.
FIG. 4 is a graph of the effect of entrained air temperature on the jet centerline temperature decay illustrating certain principles of the present invention.
DEFINITIONS
“Attenuation zone”, as may be used herein synonomously with “effective jet core length”, is the position (z/w scale) on the centerline of the jet where the temperature is 90% of the exit, or origin, temperature of the jet. This definition is offered as an aid to understanding the present invention and is not meant to imply that no further attenuation of the fibers takes place beyond this point in practicing the present invention.
“Melt flow rate” (MFR) is a measure of the viscosity of a polymer. The MFR is expressed as the weight of material which flows from a capillary of known dimensions under a specified load or shear rate for a measured period of time and is measured in grams/10 minutes at a set temperature and load according to, for example, ASTM test 1238-90b.
“Hydrohead” is a measure of the liquid barrier properties of a fabric. The hydrohead test determines the height of water (in centimeters) which the fabric will support before a predetermined amount of liquid passes through. A fabric with a higher hydrohead reading indicates it has a greater barrier to liquid penetration than a fabric with a lower hydrohead. The hydrohead test can be performed according to Federal Test Standard 191A, Method 5514, or with slight variations of this test as set forth below.
“Super fine meltblown fibers” generally refers to meltblown fibers of less than 2 micron diameter.
“Low viscosity resins” refers to a resin with an MFR of under 400 for a resin without additives.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a known apparatus for forming a meltblown web is shown schematically in FIG. 1 and is represented generally by the numeral 10 . As is conventional, the apparatus includes a reservoir 11 for supplying a quantity of fiber-forming thermoplastic polymer resin to an extruder 12 driven by a motor 13 .
The fiber-forming polymer is provided to a die apparatus 14 and heated therein by conventional electric heaters (not visible in the view shown). A primary flow of heating fluid, preferably air, is provided to die 14 by a blower 17 , which is powered by a motor 18 . An auxiliary heater 19 may be provided to bring the primary flow of heating air to higher temperatures on the order of the melting temperature of the polymer.
At the discharge opening of die 14 , quenched fibers 80 are formed and collected on a continuous foramenous screen or belt 90 into a nonwoven web 81 as belt 90 moves in the direction indicated by the arrow designated by the numeral 91 . The fiber forming distance is the distance between the upper surface of collecting web 90 and the plane of the discharge opening of die 14 .
As shown in FIG. 1, collection of fibers 80 on belt 90 may be aided by a suction box 38 . The formed nonwoven web 81 may be compacted or otherwise bonded by rolls 37 , 39 . Belt 90 may be rotated via a driven roll 95 for example.
An embodiment of the fiber forming portion of the meltblown die to apparatus 14 looking along line 2 — 2 of FIG. 1 is shown schematically in FIG. 2 and is designated generally by the numeral 20 . As shown therein, the fiber forming portion 20 of die apparatus 14 includes a die tip 40 that is connected to the die body (not shown) in a conventional manner. Die tip 40 is formed generally in the shape of a prism (normally an approximate 60° wedge-shaped block) that defines a knife edge 21 . Knife edge 21 forms the end of the portion of the die tip 40 . Die tip 40 is further defined by a pair of opposed side surfaces 42 , 44 that intersect in the embodiment shown in FIG. 2 at the horizontal plane perpendicular to knife edge 21 . Knife edge 21 at die tip 40 forms the apex of an angle that ranges from about 30° to 60°.
As shown in FIG. 2, die tip 40 defines a polymer supply passage 32 that terminates in farther passages defined by die tip 40 which are known as capillaries 27 . Capillaries 27 are individual passages formed along knife edge 21 and that generally run the length of die tip 40 .
As shown in FIG. 3, which is an enlarged cross-sectional view of die tip 40 , capillaries 27 generally have a diameter that is smaller than the diameter of polymer supply passage 32 . Generally, the diameters of all the capillaries 27 will be the same so as to have uniform fiber size formation. The diameter of the capillaries 27 is indicated on FIG. 2 by the double arrows designated “d, d.” A typical capillary diameter “d” is 0.0145 inches. Capillaries 27 desirably have a 10/1 length/diameter ratio.
As shown in FIG. 3 for example, capillary 27 is configured to expel liquid polymer, or extrudate, through exit opening 28 as a liquid polymer stream. The liquid polymer stream exits through exit opening 28 in die tip 40 and flows in a direction defining a first axis designated along dotted line 31 in FIG. 3 .
As shown in FIGS. 2 and 3, the fiber forming portion 20 of the die apparatus 14 includes a first inner wall 23 and a second inner wall 24 disposed generally opposite first inner wall 23 as the mirror image of first inner wall 23 . Inner walls 23 and 24 are also known as “hot air plates” or “hot “plates.” Throughout this specification, such walls may be referred to as either inner walls 23 and 24 or hot air plates 23 and 24 . Hot air plates 23 and 24 are configured and disposed to cooperate with die tip 40 in order to define a first primary hot air channel 30 and a second primary hot air channel 33 . The primary hot air channels 30 and 33 are located with respect to die tip 40 so that primary hot air flowing through the channels will shroud die tip 40 and form a jet thermal core upon exiting the die tip as detailed below. Various arrangements may be utilized to provide the initial runs of both the first and second hot air channels 30 and 33 . A secondary hot air duct 55 according to the present invention is provided below knife edge 21 .
Referencing FIG. 3, a first jet thermal core 50 of standard proportions is shown as it would be formed in ambient air or with quenching air surrounding the jet. A second jet thermal core 51 according to the present invention has increased length because it has been shrouded at its point of formation immediately below the knife edge 21 by additional thermal energy supplied in the form of secondary hot air flow, indicated by arrows 53 , delivered through the secondary hot air ducts 55 a , 55 b . One or both sides of the knife edge 21 may be shrouded and supplied with additional hot air flow 53 , by e.g., heaters, indicated at 57 , as illustrated in FIG. 3 . The secondary hot air to be entrained into the jet 51 is preferably substantially over typical ambient temperatures of 80° F., more preferably in the range of 125° F. to 400° F., and most preferably at about 325° F.
In operation, the typical meltblown die head jet thermal core will begin entraining cool or ambient quenching air immediately upon lengthening away from the knife edge, thus reducing its total length. Referencing FIG. 3, according to the present invention, the jet 51 will entrain the secondary hot air 53 at its point of formation at the knife edge thus allowing it to form a longer zone of forceful hot air at temperatures above the melt point of the thermoplastic polymer, leading to increased attenuation or thinning of the polymer exudate and resulting in a thinner fiber. Further, the fibers may, depending on their length of travel, be warmer upon contacting the collecting wire leading to a further changed morphology of the web formed from the individual fibers.
Referencing FIGS. 3 and 4, a jet thermal core., e.g., 50 , may be seen as having a length from the die head 20 along a longitudinal centerline, Z, and a width, W, at a point perpendicular to Z. At the point of jet formation, W is the distance between plates 23 and 24 , and measures 0.90 inches in one embodiment. Temperature at a particular Z/W point is thus an indicator of lengthening for the attenuation zone of the meltspun fibers. Referencing the graph of FIG. 4, at a Z/W point of 10 on the X axis, with a primary air temperature of about 525° F. (Y axis), the temperature of the jet has fallen to about 375° F. for the ambient (80° F.) entrained air indicated at line 60 . For 200° F. entrained air, indicated at line 62 , the jet temperature is about 420° F. at a Z/W of 10. For 400° F. entrained air, indicated at line 64 , the jet temperature is still about 480° at a Z/W of 10. Centerline temperature may be determined by a standard centerline temperature decay model
where:
T=2.12 (T o −T ∞ ) (w/z) 0.5 +T ∞ ; valid for z>4.49W
T=T o for Z<4.49 (Within the jet thermal core, temperature is constant along the centerline for Z<4.49 W)
with:
T: Temperature along the jet centerline, z axis;
T o : Temperature at the jet exit, z=0.
T ∞ : Temperature of the entrained air or surrounding air;
W: width of the jet at origin, perpendicular to the z-axis (0.090 inches in the Fiber Production Example);
Z: The axial distance from the jet exit along the z-axis
For a polymer such as Exxon Polypropylene 3746G with a melt flow rate of 1500, the attenuation zone, as shown in the below chart, has thus been lengthened by a factor of between eleven and two hundred eight percent, over the known method of having ambient air (80° F.) surrounding the jet thermal core, when using the method of shielding the jet with between 200° F. and 400° F. air to entrain according to the present invention as illustrated by the chart below. The general trends of the below chart and attendant advantages of the present invention, hold true for polymers with melt flow rates down to at least 400.
T ∞
z/w
% Increase
200
6.34
11
250
6.82
19
300
7.63
34
350
9.24
62
400
13.86
142
The length scale z/w corresponds to the position where the temperature is 90% of the initial jet temperature.
The % Increase is the value of z/w evaluated at the 90% jet exit temperature minus z/w for the correlation evaluated at standard ambient conditions for the example (80° F.), which is 5.72. This is then divided by 5.72 and multiplied by 100.
EXAMPLE 1
Fiber Production Example
A polypropylene polymer 3746G available from Exxon Chemical Co., of Baytown, Tex., U.S.A., was put through a standard meltblown die head at the following parameters:
Polymer: Exxon Polypropylene 3746G;
Polymer Throughput: 2 pounds per inch per hour, or per capillary, 0.5 grams per hole per minute;
Basis Weight: 0.5 ounces per square yard;
Hot Air Flow (secondary air introduced into the jet): 500 to 1000 feet per minute;
Hot Air Temperature: 200 to 300 degrees Fahrenheit;
Polymer Temperature: 520 degrees Fahrenheit;
Primary Air Temperature: 540 degrees Fahrenheit;
Primary Air Pressure: 6 psi
Results:
Hot Air
Hot Air
Fiber
Temperature
Flow
Size
Hydrohead
Air
(° F.)
(ft/min)
(microns)
(mbars)
Permeability
200
500
1.98
112
25
200
1000
1.83
134
20
300
500
1.32
139
20
Control
—
3.34
96
40
Fiber size was determined with SEMs and Image Analysis as set forth below. Hydrohead was measured as set forth below.
The present invention has been found to provide a substantial increase in meltblown fabric barrier properties. Hydrohead values increased by 28% and air permeability decreased by 44%. Gains in isopropyl alcohol repellency of 36% were also found due to blooming out of internal additives in certain polymer compositions under the increased heat entrainment of the present invention.
It is known that in the making of some meltspun fibers, surfactants and other active agents have been included in the polymer that is to be melt-processed. By way of example only, U.S. Pat. Nos. 3,973,068 and 4,070,218 to Weber teach a method of mixing a surfactant with the polymer and then melt-processing the mixture to form the desired fabric. The fabric is then treated in order to force the surfactant to the surface of the fibers. This is often done by heating the web on a series of heated rolls and is often referred to as “blooming.” As a further example, U.S. Pat. No. 4,578,414 to Sawyer et al. describes wettable olefin polymer fibers formed from a composition comprising a polyolefin and one or more surface-active agents. The surface-active agents are stated to bloom to the fiber surfaces where at least one of the surface-active agents remains partially embedded in the polymer matrix. In this regard, the permanence of wettability can be better controlled through the composition and concentration of the additive package. Still further, U.S. Pat. No. 4,923,914 to Nohr et al. teaches a surface-segregatable, melt-extrudable thermoplastic composition suitable for processing by melt extrusion to form a fiber or film having a differential, increasing concentration of an additive from the center of the fiber or film to the surface thereof. The differential, increasing concentration imparts the desired characteristic, e.g. hydrophilicity, to the surface of the fiber. As a particular example in Nohr, polyolefin fiber nonwoven webs are provided having improved wettability utilizing various polysiloxanes.
In a further advantage of the present invention, it has been found that use of the present invention can provide a means for blooming the additives without the additional roller treatments described above. For example one polymer composition, having fluorochemicals, as may be used to aid in repellency of low surface tension fluids, was treated according to the present invention and showed a 36% increase in isopropyl alcohol repellency as compared to the control polymer run without additional heat entrainment to increase jet thermal core length.
Of course, the particular active agent or agents included within one or more of the components can be selected as desired to impart or improve specific surface characteristics of the fiber and thereby modify the properties of the fabric made therefrom. A variety of active agents or chemical compounds have heretofore been utilized to impart or improve various surface properties including, but not limited to, absorbency, wettability, anti-static properties, anti-microbial properties, anti-fungal properties, liquid repellency (e.g. alcohol or water) and so forth. With regard to the wettability or absorbency of a particular fabric, many fabrics inherently exhibit good affinity or absorption characteristics for only specific liquids. For example, polyolefin nonwoven webs have heretofore been used to absorb oil or hydrocarbon based liquids. In this regard, polyolefin nonwoven wipes are inherently oleophillic and hydrophobic. Thus, polyolefin nonwoven fabrics need to be treated in some manner in order to impart good wetting characteristics or absorbency for water or aqueous solutions or emulsions. As an example, exemplary wetting agents that can be melt-processed in order to impart improved wettability to the fiber include, but are not limited to, ethoxylated silicone surfactants, ethoxylated hydrocarbon surfactants, ethoxylated fluorocarbon surfactants and so forth. In addition, exemplary chemistries useful in making melt-processed thermoplastic fibers more hydrophilic are described in U.S. Pat. Nos. 3,973,068 and 4,070,218 to Weber et al., and U.S. Pat. No. 5,696,191 to Nohr et al.; the entire contents of the aforesaid references are incorporated herein by reference.
In a further aspect, it is often desirable to increase the barrier properties or repellency characteristics of a fabric for a particular liquid. As a specific example, it is often desirable in infection control products and medical apparel to provide a fabric that has good barrier or repellency properties for both water and alcohol. In this regard, the ability of thermoplastic fibers to better repel alcohol can be imparted by mixing a chemical composition having the desired repellency characteristics with the thermoplastic polymer resin prior to extrusion and thereafter melt-processing the mixture into one or more of the segments. The active agent migrates to the surface of the polymeric component thereby modifying the surface properties of the same. In addition, it is believed that the distance or gap between components exposed on the outer surface of the fiber containing significant levels of active agent is sufficiently small to allow the active agent to, in effect, modify the functional properties of the entire fiber and thereby obtain a fabric having the desired properties. Chemical compositions suitable for use in melt-extrusion processes and that improve alcohol repellency include, but are not limited to, fluorochemicals. Exemplary melt-processable liquid repellency agents include those available from DuPont under the trade name ZONYL fluorochemicals and also those available from 3M under the trade designation FX-1801. Various active agents suitable for imparting alcohol repellency to thermoplastic fibers are described in U.S. Pat. No. 5,145,727 to Potts et al., U.S. Pat. No. 4,855,360 to Duchesne et al., U.S. Pat. No. 4,863,983 to Johnson et al., U.S. Pat. No. 5,798,402 to Fitzgerald et al., U.S. Pat. No. 5,459,188 and U.S. Pat. No. 5,025,052; the entire contents of the aforesaid references are incorporated herein by reference. In addition to alcohol repellency, chemical compositions can be used to similarly improve the repellency or barrier properties for other low surface tension liquids. By use of the present invention, many of the above discussed advantageous properties may be had during the formation of the fibers.
Test Procedures
Hydrostatic Pressure Test Procedure
In this test, water pressure is measured to determine how much water pressure is required to induce leakage in three separate areas of a test material. The water pressure is reported in millibars (mbars) at the first sign of leakage in three separate areas of the test specimen. The pressure in millibars can be converted to hydrostatic head height in inches of water by multiplying millibars by 0.402. Pressure measured in terms of inches refers to pressure exerted by a number of inches of water. Hydrostatic pressure is pressure exerted by water at rest.
Apparatus used to carry out the procedure includes a hydrostatic head tester, such as TEXTEST FX-3000 available from ATI Advanced Testing Instruments Corp. of Spartenburg, S.C., a 25.7 cm 2 test head such as part number FX3000-26 also available from ATI Advanced Testing Instruments Corp., purified water such as distilled, deionized, or purified by reverse osmosis, a stopwatch accurate to 0.1 second, a one-inch circular level, and a cutting device, such as scissors, a paper cutter, or a die-cutter.
Prior to carrying out this procedure, any calibration routines recommended by manufacturers of the apparatus being used should be performed. Using the cutting device, the specimen is cut to the appropriate size. Each specimen has a minimum size that is sufficient to allow material to extend beyond the outer diameter of the test head. For example, the 25.7 cm 2 test head requires a 6-inch by 6-inch, or 6-inch diameter specimen. Specimens should be free of unusual holes, tears, folds, wrinkles, or other distortions.
First, make sure the hydrostatic head tester is level. Close the drain faucet at the front of the instrument and pull the upper test head clamp to the left side of the instrument. Pour approximately 0.5 liter of purified water into the test head until the head is filled to the rim. Push the upper test head clamp back onto the dovetail and make sure the plug is inserted into the socket at the left side of the instrument. Turn the instrument on and allow the sensor to stabilize for 15 minutes. Make sure the Pressure Gradient thumbwheel switch is set to 60 mbar/min. Make sure the drain faucet is closed. The water temperature should be maintained at about 75° Fahrenheit±10° Fahrenheit. Use the Light Intensity adjustment to set the test head illumination for best visibility of water droplets passing through the specimen.
Once the set-up is complete, slide the specimen onto the surface of the water in the test head, from the front side of the tester. Make sure there are no air bubbles under the specimen and that the specimen extends beyond the outer diameter of the test head on all sides. If the upper test head clamp was removed for loading the specimen, push the clamp back onto the dovetail. Pull down the lever to clamp the specimen to the test head and push the lever until it comes to a stop. Press the Reset button to reset the pressure sensor to ZERO. Press the Start/Pause button to start the test. Observe the specimen surface and watch for water passing through the specimen. When water droplets form in three separate areas of the specimen, the test is complete. Any drops that form within approximately 0.13 inch (3.25 mm) of the edge of the clamp should be ignored. If numerous drops or a leak forms at the edge of the clamp, repeat the test with another specimen. Once the test is complete, read the water pressure from the display and record. Press the Reset button to release the pressure from the specimen for removal. Repeat procedure for desired number of specimen repeats.
Air Permeability
This test determines the airflow rate through a sample for a set area size and pressure. The higher the airflow rate per a given area and pressure, the more open the fabric is, thus allowing more fluid to pass through the fabric. Air permeability is determined using a pressure of 125 Pa (0.5 inch water column) and is reported in cubic feet per minute per square foot. The air permeability data reported herein can be obtained using a TEXTEST FX 3300 air permeability tester.
Fiber Diameter Test Procedures
Fiber diameters were tested using a Scanning Electron Microscope (SEM) Image Analysis of Meltblown Fiber Diameter test. The meltblown web was tested for Count-Based Mean Diameter and Volume-Based Mean Diameter.
Count-Based Mean Diameter
The count-based mean diameter is the average fiber diameter based on all fiber diameter measurements taken. For each test sample, 300 to 500 fiber diameter measurements were taken.
Volume-Based Mean Diameter
The volume-based mean diameter is also an average fiber diameter based on all fiber diameter measurements taken. However, the volume-based mean diameter is based on the volume of the fibers measured. The volume is calculated for each test sample and is based on a cylindrical model using the following equation:
V=πA 2 /2 P;
where A is the cross-sectional area of the test sample and P is the perimeter of the test sample. Fibers with a larger volume will carry a heavier weighting toward the overall average. For each test sample, 300 to 500 measurements were taken.
While in the foregoing specification means and method for attaining a meltblown web of fine fiber size and excellent liquid/fluid barrier properties 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.
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A method for producing super fine meltblown fibers increases the length of the meltblown jet thermal core to increase the dwell time of the extruded thermoplastic polymer within the jet thermal core. Through use of the method it is practical to use low viscosity resins and further to provide meltblown nonwovens with superior barrier properties to the passage of fluids and particularly gases. The method further provides a useful means for blooming internal additives to the surface of the fibers.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S. patent application Ser. No. 13/026,135, filed Feb. 11, 2011, now allowed; which is a continuation application of U.S. patent application Ser. No. 12/340,044, filed Dec. 19, 2008, now U.S. Pat. No. 7,906,295; which is a divisional application of U.S. patent application Ser. No. 11/144,244, filed Jun. 2, 2005, now U.S. Pat. No. 7,527,924; which is a divisional application of U.S. patent application Ser. No. 09/912,266, filed Jul. 24, 2001, now abandoned; which claims priority to U.S. Provisional Application No. 60/220,298, filed Jul. 24, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to methods for the rapid quantitation of both viable and nonviable cells. More specifically, the invention involves incubating cells with a metabolically activated visible fluorescent dye and measuring the fluorescence generated by viable cells. Total cell populations (viable+nonviable) are separately determined by measuring the native UV fluorescence of the cells. The two fluorescence readings are directly related to the number of viable and nonviable cells. This permits the user to determine the percent viability of a mixed population of live and dead cells.
[0004] 2. Description of the Related Art
[0005] The ability to quantify living cells is vitally important to the food, beverage, pharmaceutical, environmental, manufacturing and clinical industries. Several methods are currently employed by these industries to quantify prokaryotic and eukaryotic cells. These methods include, but are not limited to, the standard plate count, dye reduction and exclusion methods, electrometric techniques, microscopy, flow cytometry, bioluminescence and turbidity.
[0006] The standard plate count permits the quantitation of living cells (or clumps of cells) also known as colony forming units (cfu) when the cells are grown on the appropriate medium under optimal growth conditions ( Microbial Ecology , Atlas, R. M. and Bartha, R., Addison Wesley, Longman, N.Y., 1998). Current standards of viable organism counts are often based on the standard plate count, particularly in the food industry. However, colony counts are difficult to interpret since bacteria often clump or form chains that can give rise to significantly inaccurate estimations of the total number of viable organisms in a sample. Also, bacteria, for example, can be in a “metabolically damaged” state and not form countable colonies on a given medium. This problem is more severe when selective media are used. Thus, the standard plate count does not provide a definitive count of viable cells in a sample, which may be very important for certain purposes. Given these factors, such testing also requires skilled technicians who can distinguish individual colony forming units and who can aid in selecting appropriate growth medium. Moreover, the technique is not useful when rapid determination of cell counts is required, since it often requires over 24 hours to obtain results.
[0007] Other tests, such as dye reduction tests, rely on the ability of cells to oxidize or reduce a particular dye (Harrington, 1998). Such methods are used to measure the activity of metabolically active organisms rather than provide a measure of the total number of viable cells in a sample. Dyes, such as methylene blue, coupled with microscopic counting, are routinely employed to determine the relative number of microorganisms. The technique is widely employed but nevertheless suffers from factors that must be held constant during the assay, e.g., medium used, chemical conditions, temperature and the types of cells being examined. Also, dye reduction tests that incorporate microscopic counting techniques require trained technical personnel and often depend on subjective interpretations.
[0008] Dye exclusion methods of cell quantitation depend on the living cells having the ability to pump the dye out of the cell and into the surrounding fluid medium. While the dye may enter the interior of both living and dead cells, dead cells are not capable of actively pumping the dye out under the conditions normally used. Dye exclusion is commonly employed to enumerate animal, fungal and yeast cells. It is a method requiring skill, correct timing and proper choice of dye. It is not applicable to certain microbes and it yields incorrect viable counts with stressed cells.
[0009] An accurate estimation of the number of viable yeast cells in a sample can be obtained by the slide viability technique (Gilliland, 1959). The yeast cells are suspended in a growth medium containing 6% gelatin and the suspension is placed in a hemacytometer slide. The cell suspension is incubated for approximately 20 hours and the numbers of micro colonies are counted. Cells that form micro colonies are viable and dead cells remain as single cells. This technique is considered by the brewing industry to be the most definitive test for counting the number of viable yeast cells. Unfortunately, the long incubation time makes it unacceptable as a routine method.
[0010] Microscopic techniques typically involve counting a dilution of cells on a calibrated microscopic grid, such as a hemacytometer. A recent improvement in this technique is the direct epifluorescent filter technique (DEFT) (Pettipher et al, 1989). In this technique, samples are filtered through a membrane filter that traps the cells to be counted. A fluorescent dye is attached to the cells, which are illuminated with ultraviolet light and counted. Unfortunately, the technique requires the use of an expensive microscope and a trained individual or an expensive automated system (Pettipher et al., 1989).
[0011] Yet other methods of quantitation use flow cytometry, which involves the differential fluorescent staining of cells suspended in a relatively clear fluid stream of low viscosity. The cell suspension is mixed with the fluorescent dye and illuminated in a flow cell by a laser or other light source. The labeled cells are automatically detected with the use of a fluorescence detector focused on the cells (Brailsford and Gatley, 1993 and Pinder et al., 1993). The technique requires, and is limited by, expensive equipment. Some flow cytometric devices have been used by the food and dairy industry, but their application has been limited by the high cost of instrumentation.
[0012] Bioluminescence has been routinely employed in the food sanitation industry to detect and quantify viable organisms and cells. The method involves the use of luciferin-luciferase to detect the presence of ATP (Harrington, 1998 and Griffith et al., 1994). When used to quantify cells, the technique depends on the assumption that there is a constant amount of ATP in a living cell. ATP levels vary in a single cell over more than two orders of magnitude, making this method a relatively inaccurate technique for the enumeration of viable organisms in a sample.
[0013] Turbidity of a liquid sample can also be measured as an indication of the concentration of cells due to the light scattering and absorbing qualities of suspended cells (Harrington, 1998). The method is old but it is still employed to estimate the bacterial concentration in a sample. The method is rapid and simple but is highly inaccurate since all cells, particles and substances, including non-living particulate matter, interfere with the interpretation of the results.
[0014] The present invention for the quantitation of both viable and nonviable cells is designed to overcome at least five problems that have been identified within the field. First, the new technology circumvents the need for training personnel in how to plate, grow and count viable cells from colonies on agar plates. It also eliminates nearly all training and maintenance costs associated with most of the other methods. Second, the invention substantially decreases the time needed to determine concentrations of cells such as yeast and bacteria. Under current methodologies, quantification requires from 24-72 hours (plate count and enrichment cultures), while the present invention permits accurate quantitation in less than 15 minutes. The methylene blue test is rapid; however, the accuracy is unacceptable for cultures that are less than 90% viable. The slide viability test is accurate for large viability ranges but the time required for results is not suitable for routine use. Third, the new test is accurate over wide ranges of viability and has precision similar to the slide viability test. Fourth, the instant invention offers substantial cost savings over existing methods of cell quantitation. Fifth, the invention permits the simultaneous determination of both viable and total cells in a sample. This allows the user to accurately establish the percent viability of a cell sample (the number of viable cells to total cells). Percent viability is a crucial measurement in many industries such as the dairy and beer brewing industries and is currently carried out by the methylene blue test.
BRIEF SUMMARY
[0015] The present invention generally provides methods, kits, and devices for detecting and quantitating the number and/or percentage of viable cells in a sample. In one aspect the invention provides a method for determining the percent viability of cells in a sample, comprising providing a sample containing said cells, detecting the total cell count, contacting said cells with molecule or dye that is detectably altered by enzymatic activity of a viable cell, detecting enzymatically altered dye or molecule, thereby detecting the number of viable cells and comparing the number of total cells with the number of viable cells thereby determining the percent viability.
[0016] In another aspect, a method for detecting viable cells is provided that comprises providing a sample containing cells, contacting said sample with a dye that diffuses or is transported into said cells and wherein said dye is detectably altered by enzymatic activity of a viable cell, thereby detecting viable cells in a sample.
[0017] Yet additional aspects of the present invention include methods for quantitating viable cells in a sample, comprising providing a sample containing said cells, contacting said cells with molecule or dye that is detectably altered by enzymatic activity of a viable cell, detecting enzymatically altered dye or molecule, thereby detecting the number of viable cells in said sample and obtaining a value therefrom and correlating the detected viable cell value with a standard value, thereby quantitating the viable cells in said sample.
[0018] Further aspects include methods for quantitating total and live cells in a sample, comprising measuring total fluorescence of cells in a sample and comparing to a standard value, thereby quantitating total cells in said sample; contacting a sample with a fluorescent dye that is metabolically altered by live cells; said dye having fluorescence properties that are measurably altered when modified by live cells, detecting the metabolic alteration of the dye thereby obtaining a measurement value and comparing said value to a standard value, thereby quantitating live cells in said sample.
[0019] Still other aspects of the present invention include methods for measuring the number of total and live yeast, bacteria or other cells in a sample, comprising measuring the native fluorescence of cells in suspension, contacting said cells with a dye that penetrates into the interior of yeast or bacteria and is metabolically modified to a measurable parameter by live cells, measuring the total fluorescence and fluorescence properties provided by the metabolic alteration of said sample and correlating said fluorescence to the number of total and live cells in said sample or a fraction of the sample and determining the percent viability of said sample.
[0020] In certain embodiments the cells may be of any origin such as bacteria, yeast, or mammalian. In related embodiments the total cell count is determined by a method selected from the group consisting of native UV absorption, turbidity testing, hemacytometer measurements, fluorescence, and dye exclusion.
[0021] In yet other embodiments, the enzymatic activity that alters the dye or molecule is esterase activity. In further embodiments the enzymatically altered dye or molecule is fluorescein diacetate or OREGON GREEN™.
[0022] Other embodiments include measurement by a device, such as by a fluorometer.
[0023] The invention also provides kits for quantifying yeast or bacteria, comprising a cell suspension solution, a cell penetrating dye, and instructions for detecting dye that correlates to hemacytometer counts, plate counts or other methods of counting viable cells.
[0024] In certain embodiments the kit includes a dye that is enzymatically and detectably altered following penetration of viable cells.
[0025] In certain aspects a kit for quantifying yeast or bacteria or mammalian cells is provided, comprising: a first container containing a first solution, a second solution containing a compound that penetrates cell membranes and is metabolized to a fluorescent dye or other detectable dye that is measurable, and instructions for using the same.
[0026] In other embodiments kits of the invention further comprise a means for mixing said first solution with a sample containing an unknown number of living cells and nonliving cells, means for concentrating the cells from the mixture of said first solution with said sample and removing solids from the remainder of said mixture, and measuring native fluorescence of cells in said solution.
[0027] In still yet other embodiments the kits may further comprise a means for mixing said second solution with said cells to form a second mixture, and means for illuminating the mixture of said second solution with said cells with excitation light and measuring fluorescence emitted by said mixture, and thereby determining the amount of metabolically modified dye present in the cells that is proportional to the number of viable cells in said second solution.
[0028] In other embodiments the kits may further comprise a third solution containing a compound or compounds that increase the rate of uptake of dye into cells or speed up the rate of conversion of the detectable fluorescent form of the dye inside said cells in second solution.
[0029] In another embodiment, a device comprising solid fluorescent material consisting of an adaptor and a compound that can be used to calibrate the instrumentation used for detecting fluorescence in the cells is disclosed.
[0030] These and other aspects of the present invention will become evident upon reference to the following detailed description and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is an example of solid calibration standards for an ultraviolet and visible wavelength fluorometer.
[0032] FIG. 2 is a correlation chart of comparable Easy Count readings of total cell counts to total cell counts as determined by methlylene blue.
[0033] FIG. 3 is a correlation chart of comparable Easy Count readings of viable cell counts to total cell counts as determined by methlylene blue.
[0034] FIG. 4 is a plot of regression analysis demonstrating the relationship between the inventive method and those determined by methylene blue for total cell count.
[0035] FIG. 5 is a plot of regression analysis demonstrating the relationship between the inventive method and those determined by methylene blue for viable cell counts.
[0036] FIG. 6 is a linear correlation plot of hemacytometer counts vs. Easy Count Readings. Data points are the mean of three samples. The linear relationship is significant P<0.0001.
[0037] FIG. 7 is a linear correlation plot of hemacytometer counts that have been corrected for viability using methylene blue stain vs. Easy Count Readings. Data points are the mean of three samples. The linear relationship is significant P<0.0001.
[0038] FIG. 8 is a linear correlation between percent viability as measured by slide culture, and Easy Count values. Data points are the mean of three samples. The linear relationship is significant P<0.0001.
[0039] FIG. 9 is a plot representing fermentation tracking Fermentation tracking in a laboratory fermentation using both the Easy Count and hemacytometer methods. Time 0 is the time that the cells were pitched into fresh wort. The Y-axes represent cell counts using a hemacytometer (squares) and active cells using the Easy Count (diamonds). Data points are the mean of three samples.
[0040] FIG. 10 is a plot representing fermentation tracking during brewery scale fermentation. The Y-axes represent cell counts using a hemacytometer (squares) and the Easy Count (diamonds). Data points are the mean of three samples.
[0041] FIG. 11 is a plot depicting Percent error between operators for the three methods shown. Methylene Blue dead (stained) cells reported differences between operators of 28.3%, while Methylene Blue live (non-stained cells) was 21.0%. The error between operators for the Easy Count was significantly lower, at only 2.6%.
DETAILED DESCRIPTION
[0042] Briefly, the current invention describes novel methods that can be used to quantify live cells and total cells (total includes all cells in the sample, both viable and nonviable) such as yeast and bacteria. This allows the user to determine percent viability of the sample of cells. In one aspect, the instant invention comprises three steps: 1) determination of total cells, 2) determination of viable cells and 3) calculation of percent viability. In certain embodiments the total cells are determined by washing and incubating the cells in a solution and then measuring the native UV fluorescence of the cells in a fluorometer, thereby permitting the determination of total cell populations. Subsequently, the cells are incubated with a compound that can be metabolically converted to a visible fluorescent dye such as fluorescein diacetate, coupled with an inducer of esterase activity such as dequalinium acetate, and then the fluorescence is measured, thus permitting enumeration of viable cell populations. The fluorescent readings are correlated to standard counts such as hemacytometer counts or to the slide viability counts. The two fluorescence readings are directly related to the number of total and viable cells respectively. This permits the user to calculate the percent viability of a mixed population of live and dead cells.
[0043] As those of ordinary skill in the art can readily appreciate the present invention may be modified in certain ways to achieve the same result. In brief, the present invention utilizes one or more dyes or molecules that allow for the detection of all cells or total cells (e.g., yeast, bacteria, mammalian, etc.) in a sample and the same or different one or more dyes that are metabolized/derivatized by the viable cells in the sample to allow detection of the viable cells. Accordingly, the percent viability can then be readily determined. As can be appreciated, substances such as detergent-like compounds, surfactants, solvents, or other compounds that affect membrane polarity, membrane fluidity, permeability, potential gradient, etc., may be added to the sample to increase the rate at which the molecule or dye enters the cells in order to speed the process.
[0044] Other variations that are within the scope of the present invention include adding compounds that affect membrane polarity to decrease the rate of “leakage” of the converted dye from the cells. Further, esterase enzyme inducing chemicals such as naphthalene or dequalinium acetate may be added to increase esterase activity in living cells. In addition, esterase activity may be increased by environmental factors such as heat. Furthermore, compounds other than fluorescein diacetate, such as Calcein AM, may also be used to detect metabolically active live cells.
[0045] The stability and shelf life of the fluorescein diacetate and other chemicals may be increased by the addition of antioxidants or similar preservatives or by dissolving the FDA into other solvents besides acetone or by other stabilizing methods such as lyophilization. The fluorescence detection apparatus used may be designed for microscopic, surface, internal, solution and non-suspension sample formats.
[0046] Also included within the context of the present invention is software that permits the user to interface the fluorescence instrumentation to a computer for direct calculation of percent viability and cell concentration or other data processing or recording formats.
[0047] Compounds such as hemoglobin may be utilized to reduce background in the sample. Rinsing the sample in a buffer solution and centrifuging or filtering or otherwise retaining the cells as they are washed can be used to remove any exogenous background fluorescence.
[0048] The differences between prokaryotes and eukaryotes may also utilized to assist detection. For example, such easily detectable differences include cell membrane receptors, lack of organelles in prokaryotes, or metabolic differences. These differences can be utilized to distinguish between prokaryotes and eukaryotes by using dyes that penetrate only mitochondria or nuclei for example, or to take advantage of membrane and metabolic differences in these two cell types. This will allow the user to count a specific prokaryote or a eukaryote in a mixture of cells that contains both types of cells. For example, one may determine if bacteria contaminate a yeast cell or blood cell population.
[0049] Other variations of the present invention include altering the pH of the reaction solutions to increase the sensitivity of the reaction. Further variations include changing concentrations of the solutes to increase or decrease the sensitivity of the reaction. Alterations to the solid standards may be utilized to increase the sensitivity and dynamic range of the assay. The viability assay may be used to measure overall health or metabolic or growth status of the cells, including the ability to withstand stress. The various steps of the tests may be used independently, e.g., to measure only total cells or only live cells.
[0050] Other methods of total cell determination may include using DNA binding dyes, protein stains, cell membrane stains, antibody coupled stains, lipid dyes or other methods of detecting total cells in a sample. Viable cells may also be quantified using other methods that distinguish between live and dead cells such as surface markers, DNA stains, protein stains, antibody coupled stains, lipid dyes or other methods of detecting viable cells in a sample.
[0051] The solid standard can be made out of other materials such as, but not limited to, plastic, or by embedding chemicals such as fluorescein in a solid matrix of epoxy, acrylic, polyacrylamide or agarose or by coating a material like plastic with said chemical. Other chemicals, which have excitation and emission wavelengths in the range of the dyes or cells used to carry out the invention, could be used.
[0052] The instrument can be calibrated with solutions containing fluorescent chemicals such as fluorescein or OREGON GREEN™. Other configurations of the solid standard can be employed. The adaptor can be constructed to fit the type and make of instrument used to carry out the method. Different concentrations of the reagents may be used to carry out the method. Other methods of mixing and or concentrating samples may be used. The wash steps may also be eliminated, thus simplifying the procedure.
[0053] Yet further variations of the present invention include, but are not limited to, the use of an incubator to control the temperature of the dye conversion in the cells. Such incubation can take place in a plate counter or vial heater of some kind. Further, the samples may be arranged in an array format to allow high throughput detection.
[0054] The methods and kits of the present invention allow for the determination of the number of active cells by measuring the rate of conversion of dye by the cells. The number and activity of said cells may be determined without reaching the reaction endpoint.
[0055] The methodology has obvious application in determining the activity of yeast or bacteria in industrial fermentation applications. Thus, the methods and kits can be used to predict the number of cells required to carry out fermentation based on viable cells rather than on total cells.
[0056] As those of ordinary skill in the art can readily appreciate, the instant invention can be carried out in a single vessel and solution.
[0057] The instant invention also has applicability in assessing the activity, vitality, or number of cells under various storage conditions, comparing the metabolic activity of different cells, developing pitching rate charts for fermentation applications, and use of the method as a self-contained laboratory.
[0058] The present invention provides methods, kits and apparatuses for simple dye associated quantitation that allows one to inexpensively determine total cell counts and viable cell counts in a particular sample. An individual of ordinary skill in the art will readily appreciate that alternatives to the steps herein described for quantitating cells may be used and are encompassed herein. Accordingly, all alternatives will use a kit or method wherein a dye is utilized to stain cells and a method is used to detect or quantify the dye. One key aspect of this invention is its ability to simultaneously determine total cells and live cells in a sample in short times compared to standard methods. In preferred embodiments, detection is completed in less than 4 hours, in others in less then about 3 hours, and yet further, in less than about 2 hours, while in specific embodiments, detection is completed in less than about 1 hour, less than about 45 minutes, less than about 30 minutes, less than about 15 minutes, and less than about 10 minutes at low cost.
[0059] All patents, patent applications and references cited herein are incorporated in their entirety. Accordingly, incorporated herein by reference are U.S. Pat. Nos. 5,437,980; 5,563,070; 5,582,984; 5,658,751; 5,436,134; 5,939,282; 4,783,401; 3,586,859.
EXAMPLES
Example I
Materials and Calibration
[0060] The following shows examples of solutions, volumes and concentrations that can be used to carry out the invention. Other concentrations and volumes and different buffers with different pH values may be used. The samples and reaction solutions may be provided in any volume necessary for detection, however, in the present embodiment, small volumes (less than 1 ml) are utilized such that reagents and sample amounts are kept to a minimum. The volumes and concentrations to be utilized are any that are convenient to the practitioner of the methodology. In certain embodiments, the sample and reagent amounts range from 1 to 10,000 micro liters.
[0061] The reader used in the present embodiment is a “picofluor” hand-held fluorometer from Turner Designs, Sunnyvale, Calif. 94086. Any fluorometer that can measure fluorescence at specific wavelengths for detection of the dyes or cells can be employed in the invention. Ideally, the fluorometer can switch back and forth from visible (486 nm excitation with a 10 nm bandwidth and 550 emission with a 10 nm bandwidth) and UV (300-400 nm excitation and 410-700 nm emission) modes without changing filters or making other adjustments; however, this is not necessary to carry out the methodology. Other wavelengths may be used in combination with different dye types or cell types. The wavelength chosen will be dependent on the dye or cell type chosen for staining
[0062] The instrument needs to be calibrated in a range that permits quantitation of cells. Calibration can be carried out with solutions such as fluorescein or OREGON GREEN™ or with the use of solid standards as described below.
Materials
Solid Calibration Standards:
[0063] Materials
Colored glass rods: Mint green for the visible mode calibration, and translucent blue for the ultraviolet (UV) mode calibration. Solid calibration adapter: Black diacetyl plastic machined to fit the instrument. Glass rods are glued into the solid calibration adapter and sealed with a plastic cap, (See FIG. 1 ).
Solutions A (Cell Preparation): 1×PBS
[0000]
Ingredients (for 10× stock solution)
80 grams NaCl
2.0 grams KCl
14.4 grams Na 2 HPO 4
2.4 grams KH 2 PO 4
NaOH (enough to reach a PH of 7.4)
This recipe makes a 10× stock solution. It must be diluted 1:10 into distilled water to make a 1× working solution before being used.
Solution B (Live Cell Suspension):
[0000]
Ingredients: 0.0275 grams dequalinium acetate in
30 mL 10× Sodium acetate buffer: (13.6 grams Sodium acetate in 100 mL ddH 2 O)
Stock Solution C (Live Cell Reaction Stock):
[0077] Ingredients:
Fluorescein diacetate (FDA), 30 mg/10 mL in Acetone
Protocol
[0079] I. Calibration Using Solid Standards
[0080] To calibrate the instrument in “A” mode (UV): Standard Value=500
1) Remove the mini cell receptacle from the instrument. 2) Be sure that the instrument is in “A” mode; the letters UV should appear in the lower left corner of the screen. 3) If the instrument is not in “A” mode, press the A/B key on the instrument keypad. 4) Press the CAL key on the keypad; when prompted, press ENTER to continue. 5) When asked to insert the blank, insert the solid standard labeled “A” into the instrument with the letter “A” facing down and to the right. 6) When asked to insert the “cal”, insert the solid standard labeled “A” into the instrument so that the letter A is facing towards you, and the white cap is on top.
[0087] To calibrate the instrument in “B” mode (Visible): Standard Value=500
1) Follow all the instructions for calibration in “A” mode, making sure that that the instrument is now in “B” mode, and that the solid standard labeled “B” is now being used.
Example II
Total Cell Counts
[0089] Total cell counts can be determined by a variety of methodologies, including using the fluorometer noted above. UV operation mode is selected. A fixed volume (200 microliters) of Cell preparation solution is added to the glass sample vial. 5 microliters of sample (yeast cells) is then added to the Cell preparation solution in the vial and centrifuged for about 30 seconds to sediment the cell pellet. The cell pellet is resuspended in about 100 microliters of Cell preparation solution to the sample vial. The sample vial is then read in fluorometer. See FIG. 2 .
Example III
Viable Cell Counts
[0090] Live cells are quantitated utilizing a dye that is detectably altered by an intracellular enzyme. For example, the fluorometer noted above is set in visible mode and a fixed volume (200 microliters) of Cell preparation solution is added to the sample vial. 5 microliters of sample is added to the solution A in the sample vial and centrifuged for 30 seconds. 100 microliters of Suspension solution is added to the sample vial and 5 microliters of Reaction solution is added to the sample vial. The sample is mixed and placed in the reader and fluorescence determined at time zero and again at 15 minutes. This is the value that will be compared to the Easy Count correlation chart for conversion to cells/ml. See FIG. 3 .
Example IV
Yeast Quantitation
[0091] Yeast performance is critical to the development of quality beer. For this reason, methods of yeast analysis are an important element of the brewing process. Traditional methods including hemacytometer counting and methylene blue staining are rapid, but inaccurate and unreliable. Slide culture is an accurate measure of yeast viability, but requires a lengthy incubation period of 18 to 24 hours. As an alternative, the fluorometric assay described above is based on the metabolic activity of the yeast culture to provide brewers with a rapid and accurate estimation of active cell number. This method was compared to the hemacytometer counting technique as an estimation of cell number, and to both methylene blue staining and slide culture as measures of vitality and prediction of fermentation performance. The inventive method correlated to the hemacytometer, methylene blue, and slide culture with R 2 values of 0.985, 0.987, and 0.962 respectively, P<0.0001. An error analysis was carried out by the inventive methods, hemacytometer and methylene blue staining techniques for multiple operators performing the tests. Thus, the present invention could be used to determine correct pitching rates, monitor fermentation and propagation, and for other applications involving cell quantitation.
Yeast
[0092] All yeast cultures were obtained from Wyeast Laboratories, Mt. Hood, Oreg. Yeast samples for the experiments comparing the hemacytometer, methylene blue staining, and slide culture to the inventive methods were a 1084 strain of Saccharomyces cerevisiae . Yeast cultures tested during laboratory scale fermentations were strain 1968. Brewery scale fermentations were performed using yeast strain 1056.
[0093] Hemacytometer Counts
[0094] Hemacytometer counts were performed according to the ASBC method (6,8). Samples were removed from a slurry with an initial concentration of 198 million cells per ml, as determined by hemacytometer count, and diluted in spent wort to maintain cell integrity. Each dilution was counted in the hemacytometer as well as measured using the present method. Experiments were carried out in triplicate.
[0095] Methylene Blue Staining
[0096] Methylene blue staining was performed according to the ASBC method (6,8). Samples were removed from a slurry with an initial concentration of 198 million cells per ml, as determined by hemacytometer count, and diluted in spent wort to maintain cell integrity. Each dilution was stained and counted in a hemacytometer, as well as measured using the present method. Hemacytometer counts were corrected for viability according to the staining results. Experiments were carried out in triplicate.
[0097] Slide Culture
[0098] Slide culture was performed according to a modified version of the protocol for preparation of slide cultures for the examination of yeast and mold (5). Ten ml of yeast strain 1028 at a concentration of 433 million cells per milliliter, as determined by a hemacytometer count, were placed into a 43° C. water bath. Aliquots were removed at time intervals 0, 2, 4, 6, 8, 10, 15, 20, 30, and 40 minutes. Each was tested using the inventive method. Measurements were taken in triplicate and averaged. Slide culture samples were diluted 1:100 into wort containing 6% gelatin. 10 μl of the sample were then placed on a micro slide, covered and sealed with petroleum jelly. Each slide was incubated for 20 hours at 18° C. before microscopic examination (Microscope model, Leica DMLB). Viability was determined with the assumption that living cells had formed micro colonies, while nonviable cells remained single.
[0099] Determination of Active Cell Number Using the Instant Invention
[0100] The inventive method for determining total active cell number is based on the metabolic activity of the yeast culture. The technology involves exposing cells to proprietary chemicals that enter cells through diffusion. These molecules are converted to a fluorescent form by metabolically active cells. This fluorescent signal is quantified in a handheld battery operated fluorometer model GP320 GenPrime Inc, Spokane, Wash. The protocol is as follows: 50 μl of yeast sample was added to 500 μl of cell prep solution in a 1 ml glass test cuvette. 50 μl of dye solution was added; the cuvette was capped, and incubated for 5 minutes. After incubation, the cuvette was shaken, and the fluorescent signal quantitated in the GP320. These values were compared to the hemacytometer and methylene blue staining methods by performing tests with the inventive method on the diluted samples from these experiments. Readings were taken in triplicate and averaged. These relationships were analyzed by linear regression using Statview, SAS institute, Cary N.C.
[0101] Fermentation Tracking
[0102] Laboratory Scale: Laboratory scale fermentation tracking was carried out in a 300 ml flask by inoculating 150 ml wort with 5 ml yeast strain 1968, with an initial concentration of 420 million cells per ml, and monitoring growth using a hemacytometer and the inventive methods. Cells were grown at room temperature (21° C.). Samples were taken every 45 minutes for 5.25 hours and then periodically over the next 48 hours.
[0103] Brewery Scale Brewery Scale fermentation tracking was carried out during a typical fermentation cycle, at the Steam Plant Grill, Spokane, Wash. 99201. Hemacytometer counts and corresponding readings using the instant invention were made daily for 13 days beginning immediately following pitching.
[0104] Error
[0105] Percent error between operators was determined for the inventive method “Easy Count” method, hemacytometer counts, and the methylene blue staining method. Error analysis was performed using Microsoft Excel.
[0106] Hemacytometer: Three operators performed hemacytometer analysis of a yeast strain 1028 slurry according to the ASBC method. Each operator prepared and measured 15 samples. Results were averaged for each operator, and error between operators was calculated.
[0107] Methylene Blue: The 15 hemacytometer samples from above were stained with methylene blue according to the ASBC method. Each of the three operators counted stained cells for each sample. Results were averaged for each operator, and error between operators was calculated.
[0108] Easy Count: Easy Count tests were performed on 15 replicate samples by each of the three operators. Results were averaged for each operator, and error between operators was calculated.
[0109] Hemacytometer Counts
[0110] FIG. 6 shows the correlation between the Easy Count values and the cells/ml results of the hemacytometer. A statistically linear relationship was found between cell counts obtained by the ASBC standard method of microscopic examination using a hemacytometer and values obtained using the Easy Count, R 2 =0.985.
[0111] Methylene Blue Staining
[0112] FIG. 7 illustrates the linear correlation found between the Easy Count method and the ASBC method for methylene blue staining A statistically linear relationship was found between the Easy Count, and hemacytometer counts corrected for viability, R 2 =0.987
[0113] These results suggest that the Easy Count can be used to accurately predict active cell number. Using the results of the correlation, it is possible for the brewer to accurately determine the correct pitching rate using the Easy Count method based on 1 million active cells per ml per degree plato of wort. Additionally, the method can be used to monitor fermentation, propagation, and for other applications involving the quantitation of cells.
[0114] Slide Culture
[0115] A linear relationship was found between the Easy Count and slide culture for yeast viability, as shown in FIG. 8 .
[0116] The correlation to slide culture confirms that the Easy Count only measures active cells, since the total number of cells in this experiment remains constant.
[0117] Fermentation Tracking
[0118] Cell growth was measured during laboratory and brewery scale fermentations using both the ASBC method for hemacytometer counts, and the Easy Count method. FIG. 9 shows cell growth tracked by both methods during laboratory scale fermentation. FIG. 10 is an example of a brewery scale fermentation tracked by both methods.
[0119] Error
[0120] Results from the experiments were averaged for each operator as shown in Table 1. Percent error between operators was calculated by dividing the standard deviation of the mean by the mean, and multiplying the result by 100. Easy Count reported significantly lower error between operators than the other methods. These results are graphed in FIG. 11 .
[0000]
TABLE I
Data in
Easy
Methylene
Methylene
Millions of
Count
Blue live
Blue dead
cells/ml
mean
mean
mean
Operator 1
195.9
158.6
27.9
Operator 2
197
122.3
23.6
Operator 3
187.7
187.7
40.3
Mean
193.5
156.2
30.6
Std. Dev.
5.1
32.8
8.7
% Error
2.6
21.0
28.3
[0121] Results of the error experiments confirm previous research reporting the inaccuracies of hemacytometer counts and methylene blue staining (1, 2, 3, 4, 7). The low error associated with the Easy Count method is an improvement on these traditional techniques.
[0122] Percent error is of particular importance to the brewer due to the exacerbation of inaccuracies in the calculation of cells/ml. For example, when calculating cells/ml from a hemacytometer count of 180 live cells and 15 dead cells (counting all 25 fields and using a 1:100 dilution), the result would be 180 million live cells/ml (180*100*10000) and 15 million dead cells/ml (15*100*10000). If the error between operators when performing the live cell test is 21%, then the live cell result could be between 142-218 million cells/ml, a difference of 76 million cells/ml. With a percent error of 28% between operators, the dead cell result could be between 11-19 million cells/ml. This could result in reported viabilities between 87% and 96% for the same sample. The Easy Count has much less error associated with its performance. A reading of 6000 in the Easy Count would be 197 million active cells/ml (see equation generated in FIG. 7 .). A percent error of 3% between operators gives a range between 191-203 million cells/ml, a difference of only 12 million cells/ml. The very low error associated with the performance of the Easy Count provides much more reliable information to the brewer.
1. Mochaba, F. et al, Practical Procedures to Measure Yeast Viability and Vitality Prior to Pitching. J. Am. Soc. Brew. Chem. 56(1): 1-6, 1998. 2. O'Connor-Cox, E. et al, Methylene Blue Staining: use at your own risk. Tech. Q. Master. Brew. Assoc. 34:306-312, 1997 3. Carvell J. P. et at Developments in Using Off-Line Radio Frequency Impedance Methods for Measuring the Viable Cell Concentration in the Brewery. J. Am. Soc. Brew. Chem. 58(2): 57-62, 2000 4. Smart, K. A. et al Use of Methylene Violet Staining Procedures to Determine Yeast Viability and Vitality. J. Am. Soc. Brew. Chem. 57(1): 18-23, 19992. 5. Harrigan, W. F. Laboratory Methods in Food Microbiology 3 rd Ed. Academic Press, San Diego, Calif. 1998 6. American Society of Brewing Chemists. Methods of Analysis, 8 th Ed. The society, St. Paul. Minn. 1992. 7. Koch, H. A., et al, Fluorescence Microscopy Procedures for Quantitation of Yeasts in Beverages. American Society for Microbiology, 52(3): 599-601, September, 1986. 8. Allen, P. The Microbrewery Laboratory Manual—A Practical Guide to Laboratory Techniques and Quality Control Procedures for Small Scale Brewers, Part 1: Yeast Management. Brewing Techniques 2(4): 28-35 July/August, 1994.
Other References:
[0000]
1. Catt, S. L. Sakkas, D., Bizarro, D. Bianchi, P. G., Maxwell, W. M. and Evans, G.: (1977) Molecular and Human Reproduction 3: 821-825.
2. Ferguson, L. R. and Denny, W. A.: (1995) Mutation Research 329: 19-27.
3. Latt, S. A. and Wohleb, J. D. (1975) Chromosoma 52:297-316.
4. Harrington, W. F., (1998) Laboratory Methods in food Microbiology, Academic Press, San Diego, Calif.
5. Brailsford, M. A. and Gatley, S. (1993) New Techniques in Food and Beverage Microbiology (ed. R. G. Kroll, A Gilmour and M. Sussman), Oxford: Blackwell Scientific.
6. Griffith, C. J. Blucher, A. and Fleri, J. (1994) Food Science and Technology today 8: 209-216
7. Pettipher, G. L. Krollo, R. G. and Fan, L. J. (1989) Rapid Microbiological Methods for Foods, Beverages and Pharmaceuticals (ed C. J. Stannard, S. B. Pettit and F. A. Skinner) Oxford: Blackwell Scientific.
8. Pinder, A. C. Edwards, C., and Clarke, R. G. (1993) New Techniques in Food and Beverage Microbiology (ed. R. G. Kroll, A Gilmour and M. Sussman), Oxford: Blackwell Scientific.
9. Stannard, C. J. Pettit, S. B. and Skinner, F. A. (1989) Rapid Microbiological Methods for Foods, Beverages and Pharmaceuticals (ed C. J. Stannard, S. B. Pettit and F. A. Skinner) Oxford: Blackwell Scientific.
10. Catt, S. L. Sakkas, D., Bizarro, D. Bianchi, P. G., Maxwell, W. M. and Evans, G.: (1977) Molecular and Human Reproduction 3: 821-825.
11. Ferguson, L. R. and Denny, W. A. (1995) Mutation Research 329: 19-27.
12. Atlas, R. M. and Bartha, R. Microbial Ecology, Addison Wesley, Longman, N.Y., (1998).
13. Guldfeldt, L. U. Arneborg, N. Siegumfeldt, H. and Jespersen, L. Relationship between yeast cell proliferation and intracellular esterase activity during brewing fermentations. J. Inst. Brew. 333-338.
14. Breeuwer, P. et al. (1995). Characterization of uptake and hydrolysis of fluorescein diacetate and carboxyfluorescein diacetate by intracellular esterases in saccharomyces cerevesiae , which result in accumulation of fluorescent product. Applied and Environmental Microbiology, 61: 1614-1619.
15. Prosperi, E. (1990) Intracellular turnover of fluorescein diacetate. Influence of membrane ionic gradients on fluorescein efflux. Histochemical Journal 22: 227-233.
16. Breeuwer, P. Drocourt, J., Rombouts, F. M. and Abee, T. (1994) Energy-dependent, carrier-mediated extrusion of carboxyfluorescein from saccharomyces cerevesiae allows rapid assessment of cell viability by flow cytometry. Applied and Environmental Microbiology, 1467-1472.
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A rapid method for the quantitation of various live cell types is described. This new cell fluorescence method correlates with other methods of enumerating cells such as the standard plate count, the methylene blue method and the slide viability technique. The method is particularly useful in several applications such as: a) quantitating bacteria in milk, yogurt, cheese, meat and other foods, b) quantitating yeast cells in brewing, fermentation and bread making, c) quantitating mammalian cells in research, food and clinical settings. The method is especially useful when both total and viable cell counts are required such as in the brewing industry. The method can also be employed to determine the metabolic activity of cells in a sample. The apparatus, device, and/or system used for cell quantitation is also disclosed.
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TECHNICAL FIELD
The present invention relates to a pump system, and to a lubrication and hydraulic control system including such pumps.
BACKGROUND OF THE INVENTION
Oil within a single machine may be used for many purposes. In the context of a constant speed generator for use within an aircraft electrical power generation system, the oil may be used to lubricate bearings and other rotating parts, to act as a coolant within the generator, and may also act as a control fluid within a speed conversion system, such as a continuously variable transmission, used to ensure that a variable input speed from a prime mover is converted to a near constant generator speed. Use of oil as a coolant generally requires a high volume low pressure supply of oil. However, use of oil as a control fluid generally requires a high pressure supply of oil.
There is a penalty to be paid, in terms of energy consumed by the pumps and heat dumped into the oil, in pumping oil to high pressure. For this reason it is not desirable to use a single pump to supply oil at high pressure and high volume with the intention of tapping some of this oil off to a lower pressure for use as a coolant. Furthermore, high pressure pumps inevitably work under more stress than low pressure pumps and tend to require more frequent servicing and/or have shorter service lives.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a pump system comprising a first pump for providing a first flow of liquid for use within a cooling or lubrication system, and a second pump for providing a second flow of liquid, wherein the pumps are drivingly connected via respective coupling elements to an input element, and arranged such that failure of the second pump resulting in it requiring an increased torque at an input to the pump causes the second pump to be drivingly disconnected from the input element.
Preferably the second pump is arranged to supply liquid for use in a control system. The second pump may, for example, be arranged to supply oil for use in hydraulic actuators associated with a continuously variable transmission system. Such a system, may for example, comprise a drive belt running between two continuously variable ratio pulleys. Preferably the first and second pumps are coaxially mounted. The drive for the second pump may be provided via the first pump.
In a preferred arrangement, the first pump is driven via a first pump drive shaft and the second pump is driven via a second pump drive shaft which is coaxial with the first pump drive shaft. The first pump drive shaft and the second pump drive shaft advantageously have drive regions which receive a driving torque to be transmitted via the drive shafts and pump regions which engage with the pumps or suitable intermediate elements such that torque can be transferred from the shafts to the pumps. Each shaft also has a shear region, for example in the form of a shear neck, located between the drive region and the pump region thereof such that in the event of excessive torque being transmitted through either shaft, that shaft can shear, so as to provide protection against mechanical failure in the associated pump, while the remaining shaft continues to transmit drive to its associated pump.
Advantageously the first and second pump drive shafts are attached to a shared drive region.
Preferably the second pump is in splined engagement, via a coupling, with a drive shaft supplying motive power to it.
Preferably the second pump is attached to a mounting point such that the fixing points for the second pump do not require disassembly or substantial disassembly of the housing containing the machine serviced by the pump. Advantageously the fixing points are on an external wall of the housing. Thus the high pressure pump may be implemented as a unit removable and replaceable from the exterior of the housing. The use of the splined coupling means that disconnection of the pump from its drive and reconnection to the drive can be achieved merely by an axial movement of the second pump.
It is thus possible to provide a pump system for a continuously variable transmission and generator within a housing, wherein a low pressure pump is provided for supplying oil for lubrication and cooling components within the continuously variable transmission and generator and a high pressure pump is provided for supplying high pressure oil to control actuators of the continuously variable transmission, and wherein failure or damage of the high pressure pump causes it to become drivingly disconnected thereby leaving the low pressure pump continuing to operate in order that it can maintain a supply of coolant to components within the housing. In this event, the continuously variable transmission defaults to minimum generator drive speed.
It is further possible to provide a pump mounted to a fixing on the external surface of the housing containing the pump, with said pump being connected to a drive element via a coupling which allows the pump to be disconnected from the element by an axial movement in the first direction and connected to the drive element by an axial movement in a second direction opposed to the first direction, and wherein the coupling has a disconnect region therein designed to drivingly disconnect the pump when the torque acting on the coupling exceeds a predetermined value. Alternatively the pump may be mounted in a recess accessible either directly from the external surface of the housing or easily accessible via the removal on an element such as a plate.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will further be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic cross section through a constant speed generator for use in an avionics environment;
FIG. 2 is a schematic diagram of the oil system of the generator shown in FIG. 1;
FIG. 3 shows the physical arrangement of the low pressure and high pressure pumps in greater detail; and
FIG. 4 shows a further arrangement of pumps constituting an embodiment of the present invention.
DETAILED DESCRIPTION
The generator shown in FIG. 1 comprises a housing 1 which encloses a continuously variable transmission generally designated 2 utilising a belt drive, a low pressure pump 4 , a high pressure pump 6 , a generator, generally designated 8 , and an oil system disposed throughout the housing 1 .
The belt drive 2 enables the variable speed of an input shaft 10 which receives a drive from a spool of a gas turbine engine to be converted to a near constant speed such that the generator 8 can be run at a near constant speed. In order to do this, a first shaft 12 of the belt drive mechanism carries a flange 14 which defines an inclined surface 16 against which a drive belt bears. The shaft 12 also carries a coaxially disposed movable flange 20 drivingly connected to the shaft 12 via a splined portion (not shown). The movable flange 20 defines a further inclined surface 22 facing towards the surface 16 , which surfaces serve to define a V-shaped channel whose width can be varied by changing the axial position of the flange 20 with respect to the fixed flange 14 . The flange 20 has a circularly symmetric wall 24 extending towards and co-operating with a generally cup shaped element 26 carried on the shaft 12 to define a first hydraulic chamber 28 therebetween which is in fluid flow communication via a control duct (not shown) with an associated control valve. Similarly, a fixed flange 30 and a movable flange 32 are associated with a second shaft 36 and associated with a second hydraulic control chamber 34 . A steel segmented belt having a cross-section in the form of a trapezium, with the outer most surface being wider than the inner most surface is used to interconnect the first and second variable ratio pulleys formed between the pairs of fixed and movable flanges, respectively, in order to drivingly connect the flanges.
The position of each movable flange with respect to the associated fixed flange is controlled by the hydraulic actuators. Since the interconnecting belt is of a fixed width, moving the flanges closer together forces the belt to take a path of increased radial distance. The interconnecting belt has a fixed length, and consequently as one movable flange is moved towards its associated fixed flange, the other movable flange must move away from its associated fixed flange in order to ensure that the path from an arbitrary starting point, around one of the pulleys, to the second pulley, around the second pulley and back to the fixed arbitrary starting point remains a constant distance. The compressive forces exerted on the belt in order to ensure that the belt does not slip with respect to the pulleys can be large, and this in turn requires the high pressure pump to supply oil at a pressure of around 100 bar.
FIG. 2 schematically illustrates the oil system within the power generation system. An oil reservoir 100 acts to contain de-aerated oil. The reservoir has a first outlet 102 connected to an inlet of the high pressure pump 6 and a second outlet 104 connected to an inlet of the low pressure pump 4 . An outlet 106 of the high pressure pump 6 provides oil which is ducted towards a primary piston 110 formed by movable flange 20 and the cup shaped element 26 (FIG. 1) thereby defining the first hydraulic control chamber 28 , and a secondary piston 112 (similar to the primary piston) which contains the second hydraulic control chamber 34 . As shown in FIG. 2, both the primary piston 110 and the secondary piston 112 can be regarded as being connected between a high pressure supply line 114 and a low pressure return line 116 . The pressure in the high pressure line 114 is measured by a pressure sensor 118 and supplied to a controller (not shown). The controller uses a measurement of oil pressure, aero-engine drive speed and/or generator speed and electrical demand to schedule and/or control the hydraulic pressure acting in the primary and secondary pistons. The secondary piston 112 is connected directly to the high pressure line 114 . However, the pressure within the high pressure line 114 can be controlled by spilling pressurised lubricant from the high pressure line 114 to the low pressure return line 116 via an electrically controlled pressure control valve 120 connected between the high pressure and low pressure lines, respectively. Thus in order to increase the hydraulic pressure within the secondary piston 112 , the pressure control valve 120 is moved to restrict flow therethrough, and in order to release pressure within the secondary piston, the pressure control valve 120 is opened. A normally closed pressure return valve 122 is connected between the fluid port to the secondary piston 112 and the low pressure return line 116 . The valve 122 is normally closed, but is set to open at a predetermined pressure in order to protect the hydraulic system in the event of system over pressure.
The primary piston 110 receives high pressure fluid from the high pressure line 114 via an electrically operated flow control valve 124 . The valve 124 is in series with the pressure control valve 120 between the high pressure line 114 and the low pressure line 116 , and the primary piston 110 is connected to the node between these valves. This configuration of valves means that the pressure control valve 120 can be used to simultaneously increase the pressure in both the primary and secondary pistons in order to prevent belt slippage, whereas the balance of flow rates through the control valve 124 and the pressure control valve 120 sets the relative positions of the primary and secondary pistons. Oil from the low pressure line 116 is returned to the sump 152 .
An outlet 140 of the low pressure pump 4 supplies oil via supply line 142 to oil cooling jets 144 for spraying oil onto the moving parts of the continuously variable transmission, to jets 146 for spraying oil onto the gear train interconnecting the transmission to the generator, to jets 148 for lubricating the windings and bearings within the generator and also along a cooling path 150 for cooling the stator within the generator.
The generator 8 has a gravity drain to a dry sump 152 . Oil collecting in the sump 152 is pumped out of the sump by a single scavenge pump 154 . The output line from the scavenge pump connects with the low pressure return line 136 via an oil strainer 130 , a remotely mounted oil cooler 132 and an oil filter 134 . A pressure fill connector 156 is in fluid flow communication with the low pressure return line 194 in order to allow the oil system to be filled. An oil cooler by-pass valve 158 is connected between the output from the strainer 130 and the line 136 in order to by-pass the oil cooler and oil filter during cold start or in the event of cooler, filter or external line blockage. The oil by-pass valve is normally closed and set to open at a predetermined over pressure.
In order to drain the system, a drain plug 170 is provided in the reservoir, similarly a drain plug 172 is provided for the sump and a pressure operated vent valve 174 is provided in the generator in order to relieve the excess pressure occurring within the generator. A manually operated vent valve 176 is provided to vent pressure from the generator. An automatic air inlet valve 178 is provided to allow air to enter the generator via an injector pump 196 to provide positive internal pressure.
FIG. 3 schematically shows the arrangement of the low pressure and high pressure pumps 4 and 6 , respectively, in greater detail. An input shaft 200 of the low pressure pump 4 has a splined portion which engages with an end plate 202 carried on and drivingly connected to the first shaft 12 . The end plate 202 has an axially disposed splined aperture. The constructional details of the low pressure pump 4 are not important, save for the fact that the input shaft 200 extends through a rear wall 206 of the low pressure pump 4 and terminates in a splined portion 208 . The low pressure pump 4 is secured to internal support structures, such as internal walls 210 within the housing 1 .
The high pressure pump 6 is constructed as a removable pump unit. The walls 210 of the housing are shaped so as to form a reception region, generally indicated 212 , into which the high pressure pump 6 can fit in a sliding fit with the walls 210 . The precise constructional details of the high pressure pump are not important, save for the fact that seals, for example ring seals 214 , 216 and 218 are provided to interface between the body of the pump 6 and the walls 210 in order to form a fluid sealed engagement. Pump inlet and delivery apertures formed in the body of the pump 6 align with corresponding apertures formed in the reception region 212 . The pump 6 has an outwardly facing end plate which carries a flange or other attachment regions through which bolt holes extend such that a plurality of bolts 220 (of which only one is shown) can be used to secure the pump 6 to the housing 1 .
An input shaft 222 of the pump 6 extends towards and is coaxially aligned with the portion of the shaft 200 extending from the rear wall of the low pressure pump 4 . The shaft 222 also carries a splined portion 224 . A generally cylindrical connector 226 is provided to mechanically interconnect the shaft 222 to the shaft 200 . The connector 226 has an internal bore of a first radius which increases to a larger radius towards the ends thereof where internally facing splines are formed. Thus once the connector 226 is positioned between the shafts 200 and 222 , as shown in FIG. 3, it is prevented from undergoing axial displacement along the shafts. The connector 226 has a thinned region forming a waist. The wall thickness in the waist region is selected such that the coupling shears when the torque transmitted through it exceeds a predetermined value. This value is selected as the maximum operating torque of the high pressure pump plus a suitable tolerance margin.
In use, rotation of the shaft 12 is transmitted to the low pressure pump such that the pump provides a flow of cooling and lubricating oil. Rotation of the shaft 12 is also transmitted to the high pressure pump via the shaft 200 and the coupling 226 . Thus the high pressure pump can supply high pressure fluid for operating the actuators. However, given that the high pressure pump is more highly stressed and consequently bears an increased risk of unexpected failure, the coupling is selected such that, should the high pressure pump seize, the increased torque transmitted through the coupling 226 will cause it to fail thereby disconnecting the drive to the high pressure pump. This will cause loss of clamp pressure control and consequently the generator will have to be shut down. Nevertheless, the continued flow of cooling and lubricating oil via the low pressure pump 4 will ensure that the generator and gear box assembly does not become damaged as a result of high pressure pump failure and the resulting unscheduled shutdown.
Once the aircraft has returned to the ground, or during a planned maintenance schedule, the high pressure pump can be quickly and easily replaced by undoing the bolts 220 and removing the complete assembly from the generator. A replacement high pressure pump can then be refitted, as can a replacement coupling 226 .
FIG. 4 schematically illustrates a further arrangement of the low pressure and high pressure pumps 4 and 6 . A drive shaft 303 has a recess formed in the end portion thereof which carries inwardly facing internal splines 305 . A common drive element 300 has a first region which carries outwardly extending splines which interengage with the inwardly extending splines 305 of the shaft 303 . The common drive element 300 has a recess 302 formed in the end portion thereof which carries inwardly facing internal splines 304 . A low pressure pump drive shaft 308 has a first region 310 which carries outwardly facing splines which inter-engage with the inwardly facing splines 304 of the drive element 300 . The low pressure pump drive shaft the extends towards the low pressure pump 4 passing through a central bore thereof and drivingly engaging with the low pressure pump 4 , for example by further splines at a pump engagement region 312 . A sheer neck 314 is disposed intermediate the regions 310 and 312 in order to define a region of the shaft which will sheer when the torque acting thereon exceeds a predetermined load.
The low pressure pump drive shaft is hollow. This enables a high pressure pump drive shaft 320 to extend from the common drive element 300 via the central bore of the low pressure pump drive shaft 308 towards the high pressure pump 6 . The high pressure pump drive shaft has a first end 322 which carries outwardly facing splines 324 which engage with co-operating splines carried on the drive element 300 . Similarly, a second end 326 of the high pressure pump drive shaft 320 carries outwardly facing splines which engage with co-operating splines (not shown) to drivingly engage with the high pressure pump 6 . A shear region 330 , for example in the form of a sheer neck is exposed intermediate the first and second regions 322 and 326 , respectively.
It can be seen that both the low pressure pump and high pressure pump effectively are commonly connected to the drive element 300 , and drive shaft 303 , which provides to motive power to drive the pumps.
In the event of mechanical failure of the high pressure pump, resulting in an excess torque being transferred along the high pressure pump drive shaft 320 , then the sheer neck 330 will fail thereby causing the drive to the high pressure pump to be removed. Under these conditions, the low pressure pump 4 can still receive drive via its respective low pressure pump drive shaft 308 . However, in the event that mechanical failure occurs in the low pressure pump, resulting in excess torque being transmitted along the low pressure pump drive shaft 308 , then this can fail at the sheer neck 314 thereby disconnecting the low pressure pump. Under these circumstances, drive can still be supplied to the high pressure pump. Thus, failure of either pump still allows drive to be supplied to the other pump. This allows a controlled shutdown to be performed in the event of failure of either pump.
The low pressure pump drive shaft and high pressure pump drive shaft should remain coaxially disposed with respect to one another by virtue of being supported either by their respective pumps, or by the drive element 300 . However, in order to ensure that the shafts remain coaxially disposed, one or more O ring seals 340 may be used to hold the shafts in a spaced apart configuration.
It is thus possible to provide a pump arrangement where failure of the high pressure pump can be tolerated, and replacement of the high pressure pump is facilitated through constructional details of the pumps and housing. This gives reduced running costs, and also due to the ease of removal and inspection of the high pressure pump, also means that the task of servicing or replacing the high pressure pump becomes much easier and quicker and consequently is likely to be performed more often by operators compared to situations where they would have to demount the entire gear box and split its casing open.
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A pump system is provided where low pressure ( 4 ) and high pressure ( 6 ) pumps are coaxially mounted to receive motive power from a shared drive ( 300 ). The drive shafts are arranged such that one extends within a void in the other and both have shear regions such that, in the event of torque overload, either shaft can shear so as to disconnect the drive to it's associated pump while the other pump and shaft can continue to work.
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TECHNICAL FIELD
The present invention is related to a kinetic spray process and, more particularly, to a method for healing defective kinetically sprayed surfaces.
INCORPORATION BY REFERENCE
U.S. Pat. No. 6,139,913, “Kinetic Spray Coating Method and Apparatus,” and U.S. Pat. No. 6,283,386 “Kinetic Spray Coating Apparatus” are incorporated by reference herein.
BACKGROUND OF THE INVENTION
A new technique for producing coatings on a wide variety of substrate surfaces by kinetic spray, or cold gas dynamic spray, was recently reported in articles by T. H. Van Steenkiste et al., entitled “Kinetic Spray Coatings,” published in Surface and Coatings Technology, vol. 111, pages 62-71, Jan. 10, 1999 and “Aluminum coatings via kinetic spray with relatively large powder particles” published in Surface and Coatings Technology 154, pages 237-252, 2002. The articles discuss producing continuous layer coatings having low porosity, high adhesion, low oxide content and low thermal stress. The articles describe coatings being produced by entraining metal powders in an accelerated air stream, through a converging-diverging de Laval type nozzle and projecting them against a target substrate. The particles are accelerated in the high velocity air stream by the drag effect. The air used can be any of a variety of gases including air or helium. It was found that the particles that formed the coating did not melt or thermally soften prior to impingement onto the substrate. It is theorized that the particles adhere to the substrate when their kinetic energy is converted to a sufficient level of thermal and mechanical deformation. Thus, it is believed that the particle velocity must be high enough to exceed the yield stress of the particle to permit it to adhere when it strikes the substrate. It was found that the deposition efficiency of a given particle mixture was increased as the inlet air temperature was increased. Increasing the inlet air temperature decreases its density and increases its velocity. The velocity of the main gas varies approximately as the square root of the inlet air temperature. The actual mechanism of bonding of the particles to the substrate surface is not fully known at this time. It is believed that the particles must exceed a critical velocity prior to their being able to bond to the substrate. The critical velocity is dependent on the material of the particle and to a lesser degree on the material of the substrate. It is believed that the initial particles to adhere to a substrate have broken the oxide shell on the substrate material permitting subsequent metal to metal bond formation between plastically deformed particles and the substrate. Once an initial layer of particles has been formed on a substrate subsequent particles not only fill the voids between previous particles bound to the substrate but also engage in particle to particle bonds. The particles also break any oxide shells on previously bonded particles. The bonding process is not due to melting of the particles in the air stream because while the temperature of the air stream may be above the melting point of the particles, due to the short exposure time the particles are never heated to a temperature above their melt temperature. This feature is considered critical because the kinetic spray process allows one to deposit particles onto a surface without a phase transition.
This work improved upon earlier work by Alkimov et al. as disclosed in U.S. Pat. No. 5,302,414, issued Apr. 12, 1994. Alkimov et al. disclosed producing dense continuous layer coatings with powder particles having a particle size of from 1 to 50 microns using a supersonic spray.
The Van Steenkiste articles reported on work conducted by the National Center for Manufacturing Sciences (NCMS) and by the Delphi Research Labs to improve on the earlier Alkimov process and apparatus. Van Steenkiste et al. demonstrated that Alkimov's apparatus and process could be modified to produce kinetic spray coatings using particle sizes of greater than 50 microns.
The modified process and apparatus for producing such larger particle size kinetic spray continuous layer coatings are disclosed in U.S. Pat. Nos. 6,139,913, and 6,283,386. The process and apparatus described provide for heating a high pressure air flow and combining this with a flow of particles. The heated air and particles are directed through a de Laval-type nozzle to produce a particle exit velocity of between about 300 m/s (meters per second) to about 1000 m/s. The thus accelerated particles are directed toward and impact upon a target substrate with sufficient kinetic energy to bond the particles to the surface of the substrate. The temperatures and pressures used are sufficiently lower than that necessary to cause particle melting or thermal softening of the selected particle. Therefore, as discussed above, no phase transition occurs in the particles prior to bonding. It has been found that each type of particle material has a threshold critical velocity that must be exceeded before the material begins to adhere to the substrate by the kinetic spray process.
The kinetic spray process has been used to create very thick layers of several centimeters in thickness or more. In addition, the process has been used to create tooling because of its versatility and ability to rapidly build thick layers. One difficulty that can occur in layers of any thickness, but that can be quite noticeable in layers that are 5 millimeters or thicker, is the formation of defects. These defects typically have the shape of right conical cones. Once they begin to develop they are stable and can not be corrected by the kinetic spray process. Continued kinetic spraying leads to an enlarging of the defect. The defects are normal to the surface being sprayed and they have a near constant slant height S described by the equation:
S= ( R 2 +H 2 ) 0.5
Wherein R is the radius of the cone defect and H is the height of the cone. In the past, these defects required discarding of the kinetically sprayed surface because they could not be repaired. This leads to costly operations and time delays, particularly if the defect is not observed immediately. It would be advantageous to develop a method for repairing these defective surfaces that once applied would allow for continued kinetic spraying of the repaired surface.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is a method for repairing a defect in a kinetically sprayed surface comprising the steps of providing a kinetically sprayed surface having a defect in the surface, applying a repair coating to the defect by thermally spraying a molten material on the defect, thereby filling the defect and repairing the defect.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic layout illustrating a kinetic spray system for performing the method of the present invention;
FIG. 2 is an enlarged cross-sectional view of a kinetic spray nozzle used in the system;
FIG. 3 is photograph of a kinetically sprayed surface showing a large conical defect;
FIG. 4 is a photograph of a kinetically sprayed surface showing a string of isolated conical defects;
FIG. 5 is a photograph of a kinetically sprayed surface showing a merged string of defects that form a U-shaped channel; and
FIG. 6 is a photograph of the defects shown in FIG. 4 after repair of a portion according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention comprises a method for repairing a defective kinetically sprayed surface. The method combines the use of a thermal spray process, which is known in the art, with the relatively new technology of the kinetic spray process. The kinetic spray process used is generally described in U.S. Pat. Nos. 6,139,913, 6,283,386 and the two articles by Van Steenkiste, et al. entitled “Kinetic Spray Coatings”, published in Surface and Coatings Technology, Volume III, pages 62-72, Jan. 10, 1999 and “Aluminum coatings via kinetic spray with relatively large powder particles”, published in Surface and Coatings Technology 154, pages 237-252, 2002, all of which are herein incorporated by reference.
Referring first to FIG. 1 , a kinetic spray system for use according to the present invention is generally shown at 10 . System 10 includes an enclosure 12 in which a support table 14 or other support means is located. A mounting panel 16 fixed to the table 14 supports a work holder 18 capable of movement in three dimensions and able to support a suitable substrate material to be coated. The enclosure 12 includes surrounding walls having at least one air inlet, not shown, and an air outlet 20 connected by a suitable exhaust conduit 22 to a dust collector, not shown. During coating operations, the dust collector continually draws air from the enclosure 12 and collects any dust or particles contained in the exhaust air for subsequent disposal.
The spray system 10 further includes an air compressor 24 capable of supplying air pressure up to 3.4 MPa (500 psi) to a high pressure air ballast tank 26 . The air ballast tank 26 is connected through a line 28 to both a high pressure powder feeder 30 and a separate air heater 32 . The air heater 32 supplies high pressure heated air, the main gas described below, to a kinetic spray nozzle 34 . The temperature of the main gas varies from 100 to 3000° C., depending on the powder or powders being sprayed. The pressure of the main gas and the powder feeder varies from 200 to 500 psi. The powder feeder 30 mixes particles of a powder or a powder mixture of particles with unheated high-pressure air and supplies the mixture to a supplemental inlet line 48 of the nozzle 34 . The particles are described below and may comprise a metal, an alloy, a ceramic, or mixtures thereof. As known to those of ordinary skill in the art an alloy is defined as a solid or liquid mixture of two or more metals, or of one or more metals with certain nonmetallic elements, as in carbon containing steel. A computer control 35 operates to control both the pressure of air supplied to the air heater 32 and the temperature of the heated main gas exiting the air heater 32 . As would be understood by one of ordinary skill in the art, the system 10 can include multiple powder feeders 30 , all of which are connected to supplemental feedline 48 . For clarity only one powder feeder 30 is shown in FIG. 1 . Having multiple powder feeders 30 allows one to spray mixtures, or to rapidly switch between spraying one particle population to spraying a multiple of particle populations. Thus, an operator can form zones of two or more types of particles that smoothly transition to a single particle type and back again.
FIG. 2 is a cross-sectional view of the nozzle 34 and its connections to the air heater 32 and the supplemental inlet line 48 . A main air passage 36 connects the air heater 32 to the nozzle 34 . Passage 36 connects with a premix chamber 38 which directs air through a flow straightener 40 and into a mixing chamber 42 . Temperature and pressure of the air or other heated main gas are monitored by a gas inlet temperature thermocouple 44 in the passage 36 and a pressure sensor 46 connected to the mixing chamber 42 .
The mixture of unheated high pressure air and coating powder is fed through the supplemental inlet line 48 to a powder injector tube 50 comprising a straight pipe having a predetermined inner diameter. The predetermined diameter can range from 0.40 to 3.00 millimeters. Preferably it ranges from 0.40 to 0.90 millimeters in diameter. The tube 50 has a central axis 52 which is preferentially the same as the axis of the premix chamber 38 . The tube 50 extends through the premix chamber 38 and the flow straightener 40 into the mixing chamber 42 .
Mixing chamber 42 is in communication with the de Laval type nozzle 54 . The nozzle 54 has an entrance cone 56 that decreases in diameter to a throat 58 . Downstream of the throat is an exit end 60 . The largest diameter of the entrance cone 56 may range from 10 to 6 millimeters, with 7.5 millimeters being preferred. The entrance cone 56 narrows to the throat 58 . The throat 58 may have a diameter of from 3.5 to 1.5 millimeters, with from 3 to 2 millimeters being preferred. The portion of the nozzle 54 from downstream of the throat 58 to the exit end 60 may have a variety of shapes, but in a preferred embodiment it has a rectangular cross-sectional shape. At the exit end 60 the nozzle 54 preferably has a rectangular shape with a long dimension of from 8 to 14 millimeters by a short dimension of from 2 to 6 millimeters. The distance from the throat 58 to the exit end 60 may vary from 60 to 400 millimeters.
As disclosed in U.S. Pat. Nos. 6,139,913 and 6,283,386 the powder injector tube 50 supplies a particle powder mixture to the system 10 under a pressure in excess of the pressure of the heated main gas from the passage 36 . The nozzle 54 produces an exit velocity of the entrained particles of from 300 meters per second to as high as 1200 meters per second. The entrained particles gain kinetic and thermal energy during their flow through this nozzle. It will be recognized by those of skill in the art that the temperature of the particles in the gas stream will vary depending on the particle size and the main gas temperature. The main gas temperature is defined as the temperature of heated high-pressure gas at the inlet to the nozzle 54 . These temperatures and the exposure time of the particles are kept low enough that the particles are always at a temperature below their melting temperature so even upon impact, there is no change in the solid phase of the original particles due to transfer of kinetic and thermal energy, and therefore no change in their original physical properties. The particles exiting the nozzle 54 are directed toward a surface of a substrate to coat it.
Upon striking a substrate opposite the nozzle 54 the particles flatten into a nub-like structure with an aspect ratio of generally about 5 to 1. When the substrate is a metal and the particles include a metal, all the particles striking the substrate surface fracture the oxidized surface layer and the metal particles subsequently form a direct metal-to-metal bond between the metal particle and the metal substrate. Upon impact the kinetic sprayed particles transfer substantially all of their kinetic and thermal energy to the substrate surface and stick if their yield stress has been exceeded. As discussed above, for a given particle to adhere to a substrate it is necessary that it reach or exceed its critical velocity which is defined as the velocity where at it will adhere to a substrate when it strikes the substrate after exiting the nozzle 54 . This critical velocity is dependent on the material composition of the particle. In general, harder materials must achieve a higher critical velocity before they adhere to a given substrate. It is not known at this time exactly what is the nature of the particle to substrate bond; however, it is believed that a portion of the bond is due to the particles plastically deforming upon striking the substrate.
EXAMPLES
FIGS. 3-6 show copper coatings on copper substrates wherein the coatings are applied by a kinetic spray process and there are defects in the coating. In all the examples the copper particles were applied using a kinetic spray process with the following parameters: particle sizes were from 50 micron to less than 106 micron, main gas pressure 300 pounds per square inch, powder feed pressure 350 pounds per square inch, main gas temperature 900° F., traverse rate 0.25 inches per second, and standoff distance of approximately 1 inch.
In FIG. 6 half of the defective surface has been repaired using a thermal spray process according to the present invention. Specifically, the thermal spray was applied using a wire arc thermal spray process with the following parameters: arc gun TAFA 8835, wires Tafa Monel wire type 70T a nickel/copper alloy, 31 volts and 200 amps for the arc, air pressure of 130 pounds per square inch for atomization and 90 pounds per square inch for cooling, traverse speed of 100 millimeters per second, and a standoff distance of 9 inches.
In FIG. 3 an example of a kinetically sprayed copper surface exhibiting a large conical defect is shown at 100 . The cone is 1.3 inches high and at a height of 0.95 inches the diameter of the defect is about 0.95 inches.
In FIG. 4 an example of a string series of defects in a kinetically sprayed copper surface is shown at 106 . The multiple defects are separated, but if the kinetic spray were continued they would eventually merge.
In FIG. 5 an example were a series of defects have merged into a U-shaped channel is shown at 110 .
In FIG. 6 the sample from FIG. 4 was taken and a portion 112 was thermally sprayed with monel as described above. One can see that the defects have been fully repaired. It is now possible to continue the kinetic spray application to complete the kinetic spray coating without further defects.
The repair can be made using any thermal spray process. For example, a plasma gas thermal spray process, a High Velocity Oxy-Fuel combustion (HVOF) thermal spray process, a wire arc thermal spray, an air plasma thermal spray, a vacuum plasma, a flame spray, or radio frequency plasma thermal spray. These general processes are known in the art, but have not been utilized to repair kinetically sprayed surfaces. Any of these processes are suitable for applying a thermal sprayed layer to correct the defect.
While the preferred embodiment of the present invention has been described so as to enable one skilled in the art to practice the present invention, it is to be understood that variations and modifications may be employed without departing from the concept and intent of the present invention as defined in the following claims. The preceding description is intended to be exemplary and should not be used to limit the scope of the invention. The scope of the invention should be determined only by reference to the following claims.
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Disclosed is a method for repairing defects in kinetically sprayed surfaces. The typical defects comprise isolated or connected conical shaped holes in the kinetic spray coating. The repair involves thermally spraying a molten material into the defective area to fill in the cone followed by continued kinetic spraying to complete the coating.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pacemaker having a pulse generator for delivering stimulation pulses to a patient's heart, a control unit for controlling the delivery of stimulation pulses from the pulse generator, and a sensor provided to measure a parameter related to cardiac output of the patient.
2. Description of the Prior Art
In multi-site stimulation the PV-interval between the occurrence of an intrinsic P-wave and the application of a cardiac stimulation pulse in the ventricle can be different from the AV-interval between consecutive cardiac stimulation pulses to the atrium and the ventricle, and the PA-interval between the occurrence of an intrinsic P-wave in the right atrium and the application of a cardiac stimulation pulse in the left atrium can be different from the AA-interval between consecutive cardiac stimulation pulses to the right and left atria. The term AV-delay means in the interval between the occurrence of a paced or an intrinsic P-wave and the application of a cardiac stimulation pulse to the ventricle of the heart, and AA-delay means the interval between the occurrence of a paced or an intrinsic P-wave in the right atrium and the application of a cardiac stimulation pulse to the left atrium of the heart.
In cardiac therapy there is a primary aim to stimulate the heart such that the natural manner of a heart's functioning is re-established as far as possible. The heart is then working with a minimum waste of energy.
It is well known that cardiac output of a human being is depending on the AV-delay, see e.g. Swedish patent application no. 001534-7, corresponding to published PCT Application WO 01/80947.
In this application experimental data obtained from an animal study illustrate the dependence of several cardiac performance parameters on the AV-delay (or PV-delay). A changed AV-delay has an instant effect on the stroke volume SV but can also be observed on the mixed or central venous pressure P v O 2 after a circulatory delay. A maximum P v O 2 response was in the animal studies observed 50–80 s after the AV change. Thereafter it declined due to autonomic compensation. Thus, P v O 2 mirrors the left heart's performance and reflects the cardiac output and its transient response can be used to optimize the AV-delay according to the algorithm described therein. Simultaneously the parameters oxygen saturation SO 2 and carbon dioxide CO 2 can be used for this purpose. The carbon dioxide concentration CO 2 will, however, decrease in the same degree as the oxygen concentration increases.
It is also known from e.g. U.S. Pat. No. 4,928,688 to pace both ventricles of a heart to produce simultaneous contraction of both ventricles, thereby assuring hemodynamic efficiency. In this U.S. patent only simultaneous pacing of both ventricles is proposed. In U.S. Pat. No. 5,540,727 optimization of the pacing by selective stimulation in both atria and both ventricles with certain interatrial AA-, VV-, and AV-delays is described.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the possibilities of determining the dependence of different cardiac performance parameters on at least one of the time-delays VV-delay and AA-delay, such that significant information can be extracted as well from such parameters as the oxygen pressure (pO2) and oxygen saturation (SO2).
The above object is achieved in accordance with principles of the present invention in a pacemaker having a pulse generator for delivering stimulation pulses to a patient's heart and a control unit for controlling the delivery of stimulation pulses from the pulse generating means. A sensor is provided to measure a parameter related to cardiac output of the patient. The control unit includes an altering unit for altering at least one of the VV-delay between consecutive stimulation pulses to the right and left ventricles and the AA-delay between consecutive stimulation pulses to the right and left atria, from a predetermined first VV- or AA-delay value to a predetermined second VV- or AA-delay value, and back to the first VV- or AA-delay value. The sensor measures the parameter in a time window within a time of operation with the predetermined first VV- or AA-delay value, in a time window within a time of operation with the predetermined second VV- or AA-delay value and in a time window within a time of operation after the return back to the first VV- or AA-delay value. A determining unit includes a calculation unit for calculating an average value of the measured parameter during each of said time windows and the determining unit uses these average values to determine which one of the VV- and/or AA-delay values results in a higher cardiac output.
Thus, by using a technique analogous to that described in the above-mentioned Swedish Patent Application No. 001534-7 significant information can also be extracted from such parameters as oxygen pressure pO2 or oxygen saturation SO2 for determining the dependency of cardiac output on the VV-delay and/or the AA-delay. This is an important advantage since especially the pO2 sensor has appeared to be especially suitable to use for this type of measurement. The technique according to the invention of course also can be applied on other measured cardiac performance parameters in order to obtain more distinct results, in particular if the measurement signals are affected by disturbances in one way or the other.
In an embodiment of the pacemaker according to the invention the calculation unit forms a first difference between average values obtained during the window positioned within the time of operation with the first VV- or AA-delay value and obtained during the time window positioned within the time of operation with the second VV- or AA-delay value. The calculation unit forms a second difference between average values obtained during the time window positioned within the time of operation with the second VV- or AA-delay value and the time window positioned within the time of operation after the return of the VV- or AA-delay back to the first VV- or AA-delay value. The calculation unit uses the first and second differences to determine which VV- or AA-delay results in a higher cardiac output. In this way the possibility of extracting reliable information from the measurement signals is even further improved.
In another embodiment of the pacemaker according to the invention, the altering unit repeatedly alters the VV- or AA-delay a number of times between the predetermined first and second VV- or AA-delay values, and the calculation unit forms an average value of a resulting number of the first differences and an average value of a number of the second differences. The calculation unit uses the average values to determine which VV-and/or AA-delay values result in a higher cardiac output. The possibility of extracting information from the measurement signals is then further improved.
In a further embodiment of the pacemaker according to the invention the altering unit, after determination of which of the first and second VV- or AA-delay values indicates a higher cardiac output, alters the VV- or AA-delay between this better value of the first and second VV- or AA-delay values, and a third VV- or AA-delay value. The determining unit then determines which of the better VV- or AA-delay value and the third AV-delay value results in an indication of a higher cardiac output. The altering unit repeats this procedure until VV- and/or AA-delay values are determined which result in an indication of a highest cardiac output. Thus the pacemaker according to the invention will automatically find the optimum VV- and/or AA-delay values and will then toggle around these optimum values. If conditions should change such that other VV- and/or AA-delay values are needed to obtain a maximum cardiac output, the pacemaker will automatically find this new optimum delay values.
In another embodiment of the pacemaker according to the invention the altering unit alters the A-V delay, in addition to at least one of the VV-delay and AA-delay. The determining unit determines, from the detected changes in the parameter related to cardiac output when altering the VV- and/or AA-delays and the AV-delay, which combination of VV- and/or AA-delay values and AV-delay values results in an indication of highest cardiac output. Thus the VV-delay or the AA-delay together with the AV-delay can be adjusted to give an optimum cardiac output, or all three time-delays VV-, AA- and AV-delays can be adjusted to give an optimum cardiac output.
In another embodiment of the pacemaker according to the invention the altering unit alters the time-delay values after times of operation according to a pseudo-stochastic sequence. Since several biological variations and external disturbances have a cyclic character, which can interfere with the measurements, it is an advantage not to use a cyclic variation of the time-delays but instead to use pseudo-stochastic sequences of delay values. For patients having Left Bundle Branch Block LBBB only the VV-delay is optimized by a pseudo-sequence. For patients with both AV-block and LBBB it is possible to both optimize the AV-delay and the VV-delay by successive iterations.
In another embodiment of the pacemaker according to the invention the time windows are positioned immediately before and immediately after an alteration of the respective time-delay values. In this way changes in the measured parameter related only to the change of the time-delay in question are determined and errors originating from variations in oxygen consumption's of the patient and sensor drift are minimized.
In other embodiments of the pacemaker according to the invention the sensor measuring a parameter related to cardiac output is any of a pO2-sensor, a SO2-sensor, an average blood pressure sensor, a coronary artery flow sensor or a sinus rate sensor, and said blood pressure sensor preferably measures the blood pressure in the vena cava or the right atrium. Arterial blood pressure, average blood pressure, systolic and diastolic pressure all correlate to cardiac output.
DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrates generally a 3-chamber and a 4-chamber heart stimulator respectively.
FIG. 3 shows qualitatively the time delay and the average pO2 as a function of time.
FIG. 4 illustrates the result obtained by analysis of the data in FIG. 3 by the pacemaker according to the invention.
FIG. 5 illustrates the differential technique implemented in the pacemaker according to the invention to obtain an optimum AV-delay.
FIG. 6 illustrates different types of sampling measured parameter values.
FIG. 7 shows a pseudo-stochastic AV-delay sequence.
FIG. 8 shows the AV-delay sequence when an optimum time-delay is reached.
FIG. 9 is a diagram illustrating the spread and medium value of pO2 differences obtained from the data shown in FIG. 3 .
FIG. 10 is a block diagram of a closed loop regulation system of the pacemaker according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate two examples of multi-site stimulation.
In the 3-chamber stimulation system shown in FIG. 1 electrodes 20 , 22 , 24 are positioned in the right atrium RA, the right ventricle RV and the left ventricle LV respectively. LA denotes the left atrium.
In the 4-chamber system shown in FIG. 2 electrodes 26 , 28 , 30 and 32 are positioned in the right atrium RA, the right ventricle RV, the left atrium LA and the left ventricle LV respectively.
In FIG. 1 biventricular 3-chamber stimulation is thus illustrated and in FIG. 2 biatrial and biventricular 4-chamber stimulation is shown. In the 3-chamber stimulation according to FIG. 1 two time delays are of interest, viz. the ordinary AV-delay designated t 1 and the VV-time delay designated t 2 . In the 4-chamber system shown in FIG. 2 three time delays are of interest, viz. the ordinary AV-delay t 1 , the VV-delay t 2 , and the AA-delay t 4 .
The AV-delay t 1 on the right side of the heart can be different from the AV-delay t 3 on the left side of the heart. It should also be noted that t 1 ≈t 2 +t 3 (see W Koglek).
With the technique described below each of the above mentioned time-delays or time intervals can be optimized, and by successive iterations the optimal timing can be obtained by the method described in the following.
It should also be noted that the time settings t 1 –t 4 above are different for sensed and stimulated invents as pointed out above and therefore should be optimized separately.
FIG. 3 shows qualitatively the time interval VV- or AA-delay as a function of time. In this diagram dots are shown representing the average value of the measured pO2 during a predetermined period of time immediately before and immediately after each change in the time-delay. The marked values are average values during a predetermined time immediately preceding the position of the dot.
FIG. 4 shows the average value of the difference pO2-diff between each pair of average values from opposite sides of transitions between two time delay values for negative transitions, to the left in FIG. 4 , and for positive transitions, to the right in the FIG. 4 . From FIG. 4 it can be seen that a negative time transition increases the pO2-difference whereas a positive time step decreases the pO2-difference. This significant difference between the two pO2-differences indicates that the shorter time delay is more effective than the longer delay in this example.
In FIG. 9 the minimum and maximum values of the used pO2 differences are shown as well as the 25%–75% spread of these values and the median values.
Corresponding diagrams can be obtained for the SO2 difference, the central venous pressure difference, the average blood pressure difference, the carotid artery flow difference and the sinus rate difference.
As mentioned above it is possible to identify hemodynamic improvements of cardiac output by measuring changes in O2 after a step change of a time-delay. The oxygen contents can be measured electrochemically, by a pO2-sensor, or optically by a SO2 sensor.
Thus in the example described above the time delay, or the timing of the pulse generator of the pacemaker, is altered between two settings, e.g. a level A and a level B, one of which is the “better” one. By forming the difference between the average oxygen content, Δp (AB) during a time window of predetermined length immediately before a change of the time delay and during a time window of the same length immediately after the change from level A to level B, and comparing this result with the corresponding difference, Δp (BA), when the AV-delay is changed in the opposite direction from level B to level A, it is possible to find the best setting, A or B. The described procedure can be repeated and the results averaged for obtain a better resolution as described above.
If Δp(AB)<Δp(BA) setting A for the time delay gives a higher O2 content indicating a better ventricular performance.
If, on the other hand, Δp(AB)>Δp(BA) setting B for the time delay give a better cardiac performance.
In FIG. 5 p(#) designates oxygen measurements and n designates a first oxygen measurement p(n) after a step change of the time delay from level A to level B, and m designates first oxygen measurement p(m) after a change of time delay from level B to level A. The number of averaged O2 samples is denoted by i. In FIG. 5 , i=4.
FIG. 5 illustrates the differential technique according to the invention for selecting the best time delay value as explained above.
After n+i−1 measurements of O2 it is possible to calculate the O2 response of a change of the time delay from level A to level B according to the equation.
Δ p ( AB ) = 1 i ( ∑ x = 1 i p ( n - x ) - ∑ x = 1 i p ( n + x - 1 ) )
After m+i−1 O2 measurements it is possible to calculate the O2 response of a change of the time delay from level B to level A according to equation
Δ p ( BA ) = 1 i ( ∑ x = 1 i p ( m - x ) - ∑ x = 1 i p ( m + x - 1 ) )
By repeating this procedure several times the risk of fault decisions is practically eliminated. The corresponding mean values ψ (A, B) are given by the following equations
Ψ ( AB ) = 1 u ∑ x = 1 u Δ p ( AB ) ( x ) Ψ ( BA ) = 1 u ∑ x = 1 u Δ p ( BA ) ( x )
wherein u designates the number of times the procedure was repeated.
Thus if Ψ(AB)<Ψ(BA) the time delay value B does not improve the heart performance compared to the situation with a time-delay value equal to level A.
Different types of differentiation of the O2 signal can be used. In the example above and in situations “A” and “B” in FIG. 6 the time windows, in which the measurements are performed, i.e. the measurements samples are taken, do not overlap. In the type of differentiation illustrated at “C” and “D” in FIG. 6 the same measurement samples are sometimes used twice, since adjacent time windows, in which the measurements are carried out, overlap. The time windows in question are designated tw. Curve A illustrates a situation with an intermediate time interval between each couple of time windows in which measurements are performed, curve B illustrates a situation in which consecutive measurement time windows directly follow each other, curve C illustrates a situation with partially overlapping measurement time windows and curve D illustrates a situation in which the time windows are totally overlapping.
It is an advantage not to use a cyclic variation of the time delays, since many biological variations and external disturbances are cyclic which consequently can interfere with the measurements. Therefore it may be an advantage to change the time delays according to a pseudo-stochastic sequence as illustrated in FIG. 7 .
When a time delay value has been selected as the “better” one, this “better” value is used in a new comparison procedure in which it is compared with another time delay. In each step of this selection procedure the time delay value is favored which results in the highest O2 value, and when the optimum time delay value is reached, the time delays will toggle around this optimum value, as illustrated in FIG. 8 . In the shown example a time delay equal to B is supposed to give a better O2 value than a time delay equal to A. Further, a time delay equal to B is also supposed to give a better O2 value than a time delay equal to C.
Thus, if the situation of the patient changes such that the optimum time delays are changed, the pacemaker according to the invention will automatically find new optimum values and the pacemaker will operate with these new delays.
The differential technique described above is a simple way of eliminating errors originating from variations in oxygen consumption of the patient and sensor drift. It is also advantages to use this technique because the variations of the oxygen content due to time-delay changes are much smaller that changes in the oxygen content due to metabolic variations and other factors.
FIG. 10 shows a block diagram of the basic components of the pacemaker according to the invention. The pacemaker has a sensor S, preferably a pO2-sensor, for measuring a parameter related to cardiac output of the patient (e.g., oxygen pressure). Signals representing this parameter are received from the sensor S via a windowing unit 2 , controlled by the control unit 10 , within the aforementioned time windows. The measurement signals are processed in a suitable signal processing unit 4 and the average value during predetermined time windows immediately before and after a change in a time delay is calculated in a calculating unit 6 . In this calculating unit 6 the difference between average values obtained in the respective time windows on each side of the time delay transition are calculated, and finally an average mean value is determined for this difference for “negative” transitions and “positive” transitions in the time delay, respectively, as described above, for determining which one of the time delay values results in a higher cardiac output. This result is supplied to a control unit 8 including an altering unit 10 .
The timing of the pulse generator 12 is then controlled by the altering unit 10 to change the time delay in question between this “better” time delay value and a new time-delay value.
The length of the time window in which the measurements are performed as well as the sampling frequency can be varied by the control unit 8 .
An IEGM detector 14 is also connected to the control unit 8 , allowing the measurements to be synchronized to the cardiac cycle of the patient.
The optimum time delay at rest is normally longer than at exercise. Different activity levels therefore have to be distinguished. Considerable variations in activity level, however, can give rise to problems. The easiest way to avoid such problems is to inhibit the time delay selection function of the pacemaker when an activity sensor indicates activity of the patient exceeding a predetermined threshold level. An activity sensor 16 is therefore connected to the control unit 8 . This activity sensor can be the O2 sensor used and/or e.g. a movement sensor. If an increased activity persists over a longer time it is possible with the pacemaker according to the invention to search for a new optimum time delay(s) at this defined level of workload. In such a state it is advantageous to have a shorter decision time for deciding the optimum time delay(s) than for the “at rest” condition.
The sensor used in the pacemaker according to the invention is preferably an electrochemically pO2-sensor of the type described in PCT Application WO 98/14772. The invention is, however, not limited to the use of such a sensor. A pO2-sensor can be implanted together with an implanted pacemaker, e.g. for measuring the oxygen concentration in the right atrium. However, variations of the oxygen content in e.g. the ventricle or arteria pulmonaris can be continuously measured in a corresponding way. Further, with a pO2-sensor the measuring pulses can be made so short that synchronization of the measurement to the cardiac cycle is possible, and the pO2-sensor has proved to give reliable measurement results over time.
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
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A pacemaker has a pulse generator for delivering stimulation pulses to a patient's heart, a sensor for measuring a parameter related to cardiac output, and a control unit for controlling the delivery of stimulation pulses from the pulse generator. The control unit includes an altering unit for altering at least one of the VV delay between consecutive stimulation pulses to the right and left ventricles and the AA delay between consecutive stimulation pulses to the right and left atria. The sensor measures the parameter in various time windows within a time of operation of predetermined VV- or AA-delay values. A determining unit includes a calculation unit for calculating an average value of the measured parameter during each of said time windows and the determining unit uses these average values to determine which one of the VV- and/or AA-delay values results in a higher cardiac output.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention provides a new and improved toy seat which is adapted to be used by young children to provide fun and excitement along with good exercise for the arms and the legs.
2. Description of the Prior Art
A wide variety of children's toy seats have been provided in the past and many of these seats have been mounted on rolling bases and other structures resembling animals and the like.
It is an object of the present invention to provide a new and improved toy seat which is fun and exciting for a child to play with and which provides means for exercising the arms and legs.
Yet another object of the present invention is to provide a new and improved toy seat of the character described which is adapted to be raised to increasing elevations in response to hand pumping action.
Still another object of the present invention is to provide a new and improved toy seat of the character described which is raised to a predetermined level by hand actuated pumping action and upon reaching this level, a release valve mechanism is suddenly actuated to release pressurized fluid and thereby permit the seat to return downwardly back to a lower level.
Still another object and advantage of the present invention is to provide a seat of the character described in the foregoing object wherein the exact point or time when the seat supporting pressurized fluid is released comes normally as a surprise to the person sitting on the seat as they are continuing to operate a hand pump for raising the seat further upwardly.
Still another object of the present invention is to provide a new and improved toy seat which produces an audible sound or whistle when the fluid in the seat raising fluid chamber is suddenly released.
Another object of the invention is to provide a new and improved toy seat for children which is light in weight, easy to move about, neat in appearance and relatively low in cost.
Still another object of the present invention is to provide a new and improved toy seat which provides exercise for arms and legs of the person sitting in the seat as the seat is being pumped upwardly.
Yet another object of the invention is to provide a new and improved toy seat which provides an interesting and active pastime for young children.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages of the present invention are accomplished in an illustrated embodiment comprising a new and improved toy seat having a base with a seat mounted for movement between different levels above the base. The seat is supported on an expandable fluid chamber which is supplied with pressurized fluid from a hand pump for raising the seat to a predetermined level. When the seat reaches this predetermined level, a release valve is suddenly activated and fluid from the supporting fluid chamber is released to the atmosphere so that the seat may then settle downwardly until the release valve is again closed. The toy seat is provided with a whistle operatively associated with the exhaust or release valve so that a whistle-like audible sound is produced when the pressurized fluid in the seat supporting fluid chamber is suddenly released. The toy seat thus provides an active and entertaining activity for a child and is useful in providing exercise for the arms and legs as the seat is elevated by hand pumping action.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference should be had to the following detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a front perspective view of a new and improved toy seat constructed in accordance with the features of the present invention;
FIG. 2 is a longitudinal side elevation of the toy seat with portions cut away and shown in section for clarity;
FIG. 3 is a longitudinal elevational view similar to FIG. 2 but illustrating the seat in a higher level position;
FIG. 4 is an enlarged fragmentary sectional view of the exhaust valve mechanism of the toy seat;
FIG. 5 is a fragmentary perspective view with portions in section showing the valving mechanism of the seat in accordance with the present invention; and
FIG. 6 is a fragmentary front elevational view with portions in section of the toy seat in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, in FIG. 1 is illustrated a new and improved toy seat constructed in accordance with the features of the present invention and referred to generally by the reference numeral 10. The toy seat is especially well adapted for use by young children and provides an entertaining pastime as well as exercise for the arms and legs. The seat includes a base 12 preferably formed of molded plastic material and shaped to provide a generally cylindrical rear end portion 14 and a relatively narrow intermediate portion 16 extending forwardly therefrom. At the forward end, the base is provided with a pair of laterally outwardly extending footrests 18 having lightly inset upper wall sections 20 adapted to help retain the feet or shoes in position.
The rear end portion 14 includes a circular upper wall having a generally cylindrical recess 14a adapted to receive and hold the lower end wall 22 of a seat supporting bellows type expandable fluid chamber 24. The end wall 22 of the bellows is formed with a tang 22a at the center which depends downwardly and extends through an appropriately sized opening formed at the center of the recess 14a of the base so that the transverse lock pin 26 or other suitable fastener may be extended through the tang to secure the lower end of the fluid bellows in place as shown in FIGS. 2 and 3. The fluid chamber includes an intermediate, accordion-like, bellows section 28 which is expandable from a relatively short compressed condition as shown in FIG. 2 to an elongated or enlarged condition shown in FIG. 3, and at the upper end, the bellows is closed with an end wall 30 similar to the lower end wall 22.
The expandable fluid chamber 24 provides support and lift for a molded plastic seat 32 which is raised and lowered in response to the pressure of the fluid within the fluid chamber.
The seat 32 is mounted for relative pivotal movement on the base 12, and for this purpose an arm structure 34 of generally inverted channel shaped cross-section extends forwardly of the seat and is secured for pivotal movement about an axle pin 36 mounted in coaxial alignment with the transverse footrests 18 as best shown in FIGS. 2, 3 and 6. As shown in FIG. 6, the axle 36 extends between a pair of inner end walls 18a formed on the footrest structures 18 and these inner end walls are connected by a trough-like wall structure 38 which forms a pocket around the axle 36 for receiving hook-like forward end projections 40 adjacent the forward end portions of opposite side walls 42 of the seat arm.
As indicated, the arm is of generally channel-shaped cross-section and the side walls 42 are integrally joined with a top wall 44, an intermediate forward wall 46 and a front end wall 48 which extends between the spaced hook-like projections 40 as best shown in FIGS. 2, 3 and 6. The hook-like projections 40 are formed adjacent the lower edges of a pair of spaced apart, arcuate sections 50 interconnected with the front end wall 48 and provided with curved upper edges concentric with respect to the pivot axle 36.
In accordance with the invention, the toy seat 10 includes a bellows type pumping chamber generally indicated by the reference numeral 52 which is expandable and contractible between the positions of FIGS. 2 and 3 as illustrated. The pump chamber includes a front end wall 54 having an outwardly projecting tang 56 at the center and a rear end wall 58 having a pair of tangs 60 which project through openings provided in the intermediate front wall 46 of the seat arm 34 as shown in FIGS. 2 and 3. Anchor pins 62 or other fasteners are provided to project through openings in the tangs and thereby secure the rear end wall 58 of the pump chamber against the intermediate forward wall 46 of the arm 34.
The pump chamber 52 is actuated to expand and contract in volume by means of a pump handle 64 having an enlarged knob 66 at the outer end to facilitate grasping. At the lower end, the pump handle is formed with a transversely extending hollow sleeve 68 mounted on the pivot axle 36 so that the handle may be rocked back and forth as indicated by the arrows "A" and "B" in FIGS. 2 and 3, toward and away from the seat 32 to expand and contract the volume of the pump chamber 52 as pumping action proceeds.
Intermediate the ends, the pump handle 64 is formed with an enlarged section 70 having a flat rearward face abutting the forward end wall 54 of the pump chamber. The tang 56 extends into a recess formed in the section 70 and a pin 72 or other fastener secures the tang in place as illustrated. Below the large segment 70 of the pump handle, there is provided an arcuately curved annular wall or curved cover segment 74 having an under surface which slides along and engages the curved upper edges of the arc segments 50 on the forward end portion of the seat arm 34. The cover segments 74 extend laterally outwardly from the edges of the pump handle and provide for lateral stability thereby minimizing strain on the axle 36.
In operating the toy, a person sits on the seat 32 with the feet on the inset portions 20 of the footrests 18 and the upper end 66 of the pump handle 64 is grasped and rocked back and forth as shown in FIGS. 2 and 3. Forward pivoting movement of the pump handle causes the pump chamber 52 to expand as shown and when this occurs, outside air flows into the interior of the pump chamber through an inlet check valve 78 and a conduit 80 connected to the end wall 58 of the pump chamber. The inlet check valve 78 permits an inflow of outside air in the direction of the arrow "C" through an opening in the lower end of a valve conduit 82 having an internal annular seat 84 for the check valve 78 which comprises a flat, waffer-like disk. As best shown in FIG. 5, the lower end of the valve conduit 82 is provided with an outlet opening in the lower end with a flanged squeaker plug 86 mounted therein to provide a squeaking sound upon an inflow of air. The valve 78 prevents an outflow of air to the atmosphere when the pressure in the conduit 82 is increased above atmospheric. When the pump handle is rocked forwardly, air flows into the conduit 82 past the squeaker plug 86 and inlet check valve 78 into the transverse conduit 80 leading to the pump chamber 52. This fluid flow path is indicated by the reference arrow "D" of FIG. 2.
At the upper end, the valve conduit 82 is connected to a lower wall 88 of a relief valve chamber 90 formed on the underside of the intermediate top wall 44 of the arm 34. The chamber 90 is closed at opposite, forward and rearward ends by a pair of integrally depending end walls 92 formed with inner shoulders or recesses 92a on the lower edges in order to receive upstanding flanges 88a formed on the bottom wall 88. The upper end of the valve conduit 82 communicates with the interior of the relief valve chamber 90 through an opening provided in the lower wall 88 as shown. Above the point of interconnection with the conduit 80 leading to the pump chamber 52, the valve conduit 82 is provided with an annular seat 94 and a disk type check valve 96 is mounted to cooperate with this seat to prevent the inflow of fluid from the relief valve chamber 90 into the pump chamber 52 when the pump chamber is expanded by forward movement of the pump handle 64.
After the pump handle is moved on a forward stroke to the full forward position for maximum expansion of the pump chamber 52, the pump handle is then rocked rearwardly as shown in FIG. 3, and this reduces the volume of the pump chamber and pressurizes the fluid therein forcing air through the passage 80 as shown by the arrows "E" and "F" upwardly past the valve seat 94 and check valve 96 into the relief valve chamber 90. During this time, the check valve 78 prevents the pressurized fluid from passing out into the open lower end portion of the valve conduit 82. Pressurized air from the relief valve chamber 90 flows into the main fluid chamber 24 through an interconnecting conduit 98 extending between an opening in the lower wall 88 and the upper end enclosure 30. This causes the fluid chamber 24 to expand and elevate the seat 32 to a higher level on each rearward rocking or pumping stroke of the pump handle 64. The amount of pulling force required to complete a pumping stroke depends upon the weight of the person sitting on the seat 32 and this action provides healthy exercise for the arms and legs of a person operating the toy seat. Each time the pump handle 64 is rocked forwardly as shown in FIG. 2, a fresh volume of outside air is drawn into the pump chamber 52 and the pressurized air already in the seat supporting fluid chamber 24 is prevented from escaping by the check valve 96 and seat 94. In each pumping cycle, the handle 64 is rocked back and forth, the seat 32 is raised in elevation and the squeaker plug 86 makes interesting and amusing squeaking noise as fresh air moves into the lower end of the valve conduit 82.
The pumping process is continued in this manner until the seat is raised to a predetermined elevation or level and the selected level is controlled by a relief valve 100 preferably formed of resilient material and having a conically tapered upper end which normally seats against a relief or vent opening 44a formed in the wall 44. The relief valve 100 is mounted on the upper end of an elongated valve stem 102 which projects downwardly through an opening in a central portion of a snap action, leaf spring 104 extending across the valve chamber 90 between the shouldered recesses 92a in the opposite end walls. In a normal or closed position as shown in FIGS. 2 and 5, the snap action leaf spring 104 is curved upwardly in the central portion and firmly biases the upper end of the relief valve 100 to close off the exhaust port 44a. The lower end of the valve stem 102 extends downwardly through the wall 88 of the relief valve chamber and is sealed with a grommet 106 which permits free sliding movement of the valve stem without leakage from the chamber. The lower end of the valve stem is connected to a cord 108 which is threaded downwardly through the central opening or bore in an upstanding sleeve 110 formed on the intermediate wall 16 of the base 12.
When the seat 32 is pumped upwardly by the handle 64 and eventually reaches a predetermined level, the valve cord 108 becomes taught and further pumping action causes the valve member 100 to unseat away from the exhaust port 44a which permits a rapid escape of fluid from fluid chambers 24 and 90. The length of the cord 108 can be adjusted from time to time to determine and change the level at which the relief valve is operated. In order to provide a more rapid release of the relief valve from the closed to the open position, a snap action spring 104 is utilized and when sufficient force is exerted by the cord 108 the spring 104 snaps from the closed position of FIGS. 2 and 5 to the open position of FIGS. 3 and 4. When this occurs, the pressurized fluid in the chamber 90 and interconnected fluid chamber 24 suddenly and rapidly escapes to the atmosphere through the orifice opening 44a. The precise level at which the valve opens is not readily apparent to a person sitting on the seat and pumping the handle 64 and it generally comes as a surprise when the relief valve opens and the seat begins to descend. This provides interesting action and a surprise to the person on the seat 32.
In accordance with the invention, the toy seat 10 includes a whistle enclosure 112 having a hollow resonating chamber above the opening 44a. This chamber has an outlet opening 112a and produces a whistling sound whenever the relief valve 100 is opened permittng an outflow of pressurized fluid from the chamber 90 and the seat chamber 24. The whistling sound also provides a sudden start and excitement when the seat pressure is suddenly released and the seat begins to descend.
Although the present invention has been described with reference to a single illustrated embodiment thereof it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.
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A toy seat comprises a base with a seat mounted for movement between different levels above the base and a fluid chamber in the form of a bellows supports the seat on the base to move up and down. A hand pump is provided for supplying pressurized fluid to expand the fluid chamber to raise the seat to a level wherein suddenly the pressurized fluid in the chamber may be released to the atmosphere and the seat then settles downwardly until the pressurized fluid is again supplied to the chamber by manual operation of the pump. The toy seat also includes a whistle which is associated with an exhaust or release valve so that a whistling sound is produced whenever pressurized fluid from the seat supporting chamber is released.
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FIELD OF THE INVENTION
The present invention relates to a separating agent for enantiomeric isomers, in particular, a separating agent used for separating enantiomeric isomers in liquid chromatography. More particularly, the present invention relates to a separating agent for enantiomeric isomers that can enantiomerically resolve a broad range of chiral compounds with high separation factors in the analysis of pharmaceuticals, foods, agricultural chemicals, fragrants and the like and a method of evaluating the ability of recognizing asymmetry of such a separating agent.
PRIOR ARTS
Many organic compounds have isomers that have the same physical and chemical properties, such as boiling point, melting point and solubility but show a difference in a physiological activity, i.e., enantiomeric isomers. This difference in physiological activity between the isomers is attributable to the following. In most cases, proteins and carbohydrates that compose a living body of a living organism are composed only of the one of enantiomeric isomers so that they show a difference in the manner of action to the other kinds of enantiomeric isomers, resulting in a difference in the physiological activity. This can be compared to a difference in easiness (difference in physiological activity) of wearing of a glove for left hand (i.e., a living organism as an enantiomerically active substance) between the right hand and the left hand (respective enantiomeric isomers that act).
In particular, in the field of pharmaceutical preparations, in many cases, there are significant differences in medical property and toxicity between the two enantiomeric isomers. Therefore, in the Guideline for the Production of Pharmaceuticals, the Ministry of Health, Labor and Welfare describes a policy for making a sharp distinction between enantiomeric isomers saying “when the drug of interest is a racemic modification, it is desirable to preliminarily study absorption, distribution, metabolism and excretion kinetics of each enantiomeric isomer.”
Since enantiomeric isomers have completely the same physical and chemical properties, such as boiling point, melting point, and solubility as previously stated, they cannot be analyzed by ordinary separation means. For this reason, extensive studies have been made on techniques for separating enantiomeric isomers that analyze a wide variety of enantiomeric isomers conveniently and with high precision. As a result, as an analytical technique that meets these requirements, an enantiomeric resolution method by high performance liquid chromatography (HPLC), in particular an enantiomeric resolution method by using a chiral column for HPLC has been developed. The chiral column referred to herein uses an asymmetry recognition agent itself or a chiral stationary phase composed of an asymmetry recognition agent supported on a suitable carrier.
For example, enantiomerically active poly (triphenylmethyl methacrylate) (cf., JP 57-150432 A), cellulose or amylose derivatives (Y. Okamoto, M. Kawashima and K. Hatada, J. Am. Chem. Soc., 106, 5357, 1984), ovomucoid, which is a protein (JP 63-307829 A) and the like have been developed.
It has been known that among many chiral stationary phases for HPLC, an enantiomeric resolution column having supported cellulose or amylose derivative on silica gel has high asymmetry recognition ability to an extremely wide variety of compounds. Furthermore, in recent years, studies on a liquid chromatographic fractionation method for fractionating enantiomerically active substances on an industrial scale including a chiral stationary phase for HPLC and a simulated moving bed method, which is a continuous liquid chromatographic fractionation method in combination have been developed (Pharm Tech. Japan, 12, 43 (1996)).
For example, enantiomerically active poly (triphenylmethyl methacrylate) (cf., JP 57-150432 A), cellulose or amylose derivatives (Y. Okamoto, M. Kawashima and K. Hatada, J. Am. Chem. Soc., 106, 5357, 1984), ovomucoid, which is a protein (JP 63-307829 A) and the like have been developed.
It has been known that among many chiral stationary phases for HPLC, an enantiomeric resolution column having supported cellulose or amylose derivative on silica gel has high asymmetry recognition ability to an extremely wide variety of compounds. Furthermore, in recent years, studies on a liquid chromatographic fractionation method for fractionating enantiomerically active substances on an industrial scale including a chiral stationary phase for HPLC and a simulated moving bed method, which is a continuous liquid chromatographic fractionation method in combination have been developed (Pharm Tech. Japan, 12, 43 (1996)).
In the case of chiral stationary phase for HPLC used as analysis means, complete separation of two enantiomeric isomer peaks in a short analysis time gives a full satisfaction. However, in order to further increase fractionation productivity, a liquid chromatographic fractionation method as production means has been required to not only completely separate a compound as a target of fractionation but also further separate two enantiomeric isomer peaks of the target compound; that is, a chiral stationary phase having a value of separation factor α as high as possible has been desired.
Under the circumstances, various contrivances have been made to more fully develop the asymmetry recognition ability of the chiral stationary phase including an enantiomerically active polymer compound such as, for example, a polysaccharide derivative as an asymmetry recognition agent to obtain a further increased value of separation factor α. Under the present conditions, however, there are no evaluation methods for high asymmetry recognition ability other than those that use an HPLC measurement in reality. Accordingly, a simpler and easier method of evaluating asymmetry recognition ability has been demanded.
JP-A 2-289601 discloses a separating agent comprising a polysaccharide derivative having —CO—NHR for OH.
SUMMARY OF THE INVENTION
The present invention has been achieved under the above-mentioned circumstances. That is, an object of the present invention is to provide a simpler and easier method of evaluating asymmetry recognition ability. Another object of the present invention is to provide a separating agent for enantiomeric isomers having higher asymmetry recognition ability by using the evaluation method.
As a result of extensive studies for achieving the above-mentioned objects, the inventors of the present invention have now found that those separating agents that cause polymer compounds which have been supported therein to exhibit exothermic peaks before the polymer compounds reach their decomposition temperatures in a differential thermal calorimetric curve obtained in a heat elevation process in differential scanning calorimetry (DSC) have high values of separation factors α of enantiomeric isomers, thereby achieving the present invention.
Therefore, the present invention provides a separating agent for enantiomeric isomers, comprising an enantiomerically active polymer compound supported thereon, wherein the polymer compound has an exothermic peak before a decomposition temperature of the polymer compound supported is reached in a differential calorimetric curve obtained in a process of temperature elevation in differential scanning calorimetry (DSC) on the separating agent.
It then provides a method of evaluating asymmetry recognition ability of a separating agent for enantiomeric isomers, comprising: performing a differential scanning calorimetry (DSC) of the separating agent for enantiomeric isomers having supported thereon an enantiomerically active polymer compound to obtain a differential calorimetric curve in a process of temperature elevation therein; and observing presence or absence of an exothermic peak of the polymer compound in the differential calorimetric curve before a decomposition temperature of the supported polymer compound is reached.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by embodiments. However, the present invention is not limited thereto.
The enantiomerically active polymer compounds used in the present invention include polysaccharide derivatives, enantiomerically active polyamides, enantiomerically active polyesters, enantiomerically active polyamino acids, enantiomerically active polyethers, polymers having bound thereto enantiomerically active compounds, proteins, and modified proteins and complexes of these. In particular, polysaccharide derivatives or complexes thereof are suitably used.
The polysaccharide derivatives used in the present invention can be obtained by reacting a polysaccharide with a compound having a functional group that is reactive with the hydroxyl groups of the polysaccharide.
The polysaccharide may be any polysaccharide, being a synthetic or natural one or a modified natural one. The polysaccharide has preferably a high regularity in the manner of binding between saccharides. Examples of the polysaccharide include β-1,4-glucan (cellulose), α-1,4-glucan (amylose or amylopectin), α-1,6-glucan (dextran), β-1,6-glucan (pustulan), β-1,3-glucan (for example, curdlan, schizophyllan, etc.), α-1,3-glucan, β-1,2-glucan (crown gall polysaccharide), β-1,4-galactan, β-1,4-mannan, α-1,6-mannan, β-1,2-fructan (inulin), β-2,6-fructan (levan), β-1,4-xylan, β-1,3-xylan, β-1,4-chitosan, α-1,4-N-acetylchitosan (chitin), pullulan, agarose and alginic acid. Also, starches containing amylose are included therein. Among these polysaccharides, it is preferable to use cellulose, amylose, β-1,4-xylan, β-1,4-chitosan, chitin, β-1,4-mannan, inulin, curdlan, etc. which can be easily obtained as highly pure polysaccharides, still preferably cellulose and amylose.
It is preferable that such a polysaccharide has a number-average degree of polymerization (i.e., the average number of pyranose or furanose rings per molecule) of at least 5, still preferably at least 10. From the viewpoint of handling properties, it is preferable that the number-average degree of polymerization thereof is not more than 1,000, though the upper limit thereof is not particularly defined.
The compounds having functional groups capable of reacting with the hydroxyl groups of the polysaccharide may be isocyanic acid derivatives, carboxylic acids, esters, acid halides, acid amides, halides, aldehydes, alcohols and any other compounds having leaving groups. As these compounds, use can be made of aliphatic, alicyclic, aromatic and heteroaromatic ones. Particularly preferable examples of the polysaccharide derivative to be used in the present invention include ester and carbamate derivatives of polysaccharides having at least 0.1 ester or urethane bond per glucose unit, more preferably ester and carbamate derivatives having an asymmetic center.
The enantiomerically active polymer compound is supported on the carrier preferably in an amount of from 1 to 100% by weight, more preferably from 5 to 60% by weight, and particularly preferably from 15 to 40% by weight, based on the carrier.
The carrier referred to herein includes organic porous substrates and inorganic porous ones, preferably inorganic porous ones. Appropriate examples of the organic porous substrates include polymers comprising polystyrene, polyacrylamide, polyacrylate, etc. Appropriate examples of the inorganic porous substrates include silica, alumina, magnesia, glass, kaolin, titanium oxide, silicates and hydroxyapatite. Silica gel may be cited as a particularly preferable carrier. The particle diameter of the silica gel is from 0.1 μm to 10 mm, preferably from 1 μm to 300 μm, and more preferably from 5 μm to 50 μm and the average pore size thereof is from 10 angstroms to 100 μm, preferably from 50 angstroms to 50,000 angstroms. When silica gel is employed as the carrier, it is preferable to preliminarily surface-coat the silica gel so as to exterminate the effects of the silanol remaining therein, though a non-surface-treated one may be used without any problem.
In the separating agent having supported thereon the enantiomerically active polymer compound of the present invention, the polymer compound may be applied and supported on the carrier through physical adsorption, or may be more firmly immobilized thereto by further forming chemical bonds. These chemical bonds may be formed by, for example, chemical bonds between the carrier and the coated polymer compound, chemical bonds between the polymer compound molecules on the carrier, chemical bonds formed by using a third component, or chemical bonds formed by reactions caused by irradiation of light, radiation such as γ-ray, or electromagnetic wave such as micro wave onto the polymer compound on the carrier, or by radical reactions. Furthermore, enantiomerically active polymer compounds as asymmetry recognition agents and enantiomerically inactive polymer compounds may be simultaneously supported on the carrier.
The separating agent for enantiomeric isomers of the present invention is characterized in that when differential scanning calorimetry (DSC) is performed, the polymer compound has an exothermic peak in a differential calorimetric curve obtained in a first heat elevation process before its decomposition temperature is reached; separating agents having such exothermic peaks can have higher asymmetry recognition ability.
It is preferred that DSC measurements are performed in a nitrogen atmosphere. The rate of heat elevation is not particularly limited. It is preferred to perform the DSC measurements at a rate of 0.5 to 100° C./min, more preferably 5 to 50° C./min. The temperatures at which the DSC measurements are started are not particularly limited. However, it is preferred that the measurements are started at lower temperature than room temperature.
In the DSC measurements, the separating agent containing the polymer compound of the invention, having the exothermic peak(s), may be considered to have an unstable structure in part or on a whole. The method of producing the separating agent containing the polymer compound of the invention is not in particular specified. Conditions of preparation that will influence formation of the unstable structure include, in general for example, heating of the polymer compound, rapid cooling, addition of a plasticizer or another additive and modification caused by introducing a bulky substituent into the polymer compound.
The separating agent of the invention can be obtained by dissolving an enantiomerically active polymer compound in a solvent to obtain a polymer dope, supporting it on a carrier and distilling the solvent out. After the distillation, the product may be heated and then cooled. The product is determined with a differential scanning calorimetry (DSC) to select a polymer compound having an exothermic peak before the decomposition temperature of the polymer compound supported has been reached in the differential calorimetric curve obtained in temperature elevation procedures with the differential scanning calorimetry (DSC) on the separating agent. The supporting step may be carried out by mixing or coating. The distillation may be carried out by heating at a reduced pressure. The supporting step and the distillating step may be repeated.
The separating agent of the invention may be obtained with changed distillating period in time, which may depend on the selected solvent or the distillating temperature.
The solvent to use for supporting the enantiomerically active polymer compounds on the carrier includes any solvent for the used polysaccharide derivative, for example, ketone solvents, ester solvents, ether solvents, amide solvents, imide solvents, hydrocarbon solvents, acid solvents, amine solvents, halogenated solvents, alcohol solvents and nitrile solvents. A single or plural mixed solvents may be used.
The temperature for supporting the enantiomerically active polymer compound on the carrier may be 20° C. to 80° C.
The distilling period in time after having supported the enantiomerically active polymer compound on the carrier may depend on the solvent used for the supporting step.
The heating treatment may be carried out at any temperature that is not more than the decomposition temperature of the supported enantiomerically active polymer compound, for example preferably at 100° C. or lower. The cooling step may be effected rapidly or slowly. The slow cooling may be carried out by allowing the product to stand at a room temperature after the heating. The rapid cooling may be carried out with ice bathing or in a liquid at 0° C. or lower such as dry ice-ethanol, dry ice-methanol and liquid nitrogen.
The separating agent of the invention may be used in enantiomeric resolution for example, in chromatography such as gas chromatography, liquid chromatography, thin layer chromatography, super critical chromatography and capillary electrophoresis and then membrane separation. In particular it may be preferably used as a chiral immobilized (stationary) phase of the liquid chromatography. it may be also used for enantiomeric resolution by continuous-wise liquid chromatography such as the simulated moving bed.
A third additive may be used at the supporting step of the enantiomerically active polymer compound on the carrier, for example, any compound not bleeding out during separating use, preferably a polymer such as polystyrene, polycaprolactam, AS resin, poly-methyl methacrylate, polyacetal and polycarbonate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a chart illustrating the measurement results of DSC as measured in the step (4) in Example 1 of the present invention;
FIG. 2 is a chart illustrating the measurement results of DSC as measured in the step (4) in Example 2 of the present invention; and
FIG. 3 is a chart illustrating the measurement results of DSC as measured in the step (4) in Comparative Example 1 of the present invention.
EXAMPLES
Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention should not be construed as being limited to these examples.
Example 1
Production of an Amylose Tris[(S)-phenylethyl Carbamate]-Supported Separating Agent for Enantiomeric Isomers having an Exothermic Peak before Reaching a Decomposition Temperature
(1) Surface Treatment of Silica Gel
A porous silica gel (particle diameter: 20 μm) was subjected to aminopropylsilane (APS) treatment in a conventional manner by reacting with 3-aminopropyltriethoxysilane. The obtained APS-treated silica gel was reacted with isocyanate to obtain carbamoyl-surface-treated silica gel.
(2) Synthesis of Amylose Tris[(S)-phenylethyl Carbamate]
In a nitrogen atmosphere, 109 g of (S)-phenylethyl isocyanate (2 equivalents based on hydroxyl group of amylose) was added to a mixture of 20 g of amylose and 500 ml of dry pyridine and the obtained mixture was heated under stirring at a pyridine reflux temperature for 24 hours. After cooling, the reaction mixture was poured into 5.0 liters of methanol stirred at room temperature over 10 minutes. Then, the resultant mixture was stirred for 30 minutes, and left to stand for 30 minutes. After, the supernatant was removed by decantation. The solid of amylose tris[(S)-phenylethyl carbamate] finally precipitated was taken up by filtration through a glass filter and washed with 300 ml of methanol three times on the glass filter, followed by vacuum drying (60° C., 5 hr). As a result, 69.2 g (93%) of yellowish white solid was obtained.
(3) Supporting of Amylose Tris[(S)-phenylethyl Carbamate] on Silica Gel
10 g of the amylose tris[(S)-phenylethyl carbamate] obtained in the step (2) was dissolved in a mixed solution composed of 95 ml of tetrahydrofuran (THF) and 5 ml of N,N-dimethylacetamide. Half of the resultant polymer dope was applied uniformly onto 40 g of the silica gel described in the step (1). After the completion of the application, THF was distilled off under reduced pressure with heating over 60 minutes or more. The remaining half of the polymer dope was uniformly applied to the silica gel in the same manner as described above and THF was distilled off under reduced pressure in the same manner as the first time to obtain the objective amylose tris[(S)-phenylethyl carbamate]-supported separating agent.
(4) Differential Scanning Calorimetry (DSC) of the Separating Agent Prepared in the Step (3)
For measurements, DSC-7 manufactured by Perkin-Elmer Corporation was used. The separating agent was subjected to vacuum drying at 50° C. for 2 hours before the measurement and 5 mg of the separating agent charged in an aluminum-made cell having a diameter of 7 mm was used as a sample. The measurement was performed in a nitrogen atmosphere by holding the sample at 0° C. for 3 minutes, elevating the temperature at a rate of 20° C./min to 210° C. and observing the coming-in and going-out of heat during the process. FIG. 1 shows the obtained measurement results of DSC.
(5) Preparation of a Packed Column for HPLC from the Prepared Separating Agent
A stainless steel-made column having a length of 25 cm and an inner diameter of 1.0 cm was packed with the separating agent having supported the amylose tris[(S)-phenylethyl carbamate] on silica gel prepared in the step (3) above as a packing agent by a slurry packing method to prepare a column for separating enantiomeric isomers.
Example 2
Preparation of an Amylose Tris[(S)-phenylethyl Carbamate]-Supported Separating Agent for Enantiomeric Isomers having an Exothermic Peak before Reaching a Decomposition Temperature
(1) Surface Treatment of Silica Gel
Surface treatment was performed in the same manner as in Example 1-(1).
(2) Synthesis of Amylose Tris[(S)-phenylethyl Carbamate]
Synthesis was conducted in the same manner as in Example 1-(2).
(3) Supporting of Amylose Tris[(S)-phenylethyl Carbamate] on Silica Gel
10 g of the amylose tris[(S)-phenylethyl carbamate] obtained in the step (2) was dissolved in 100 ml of tetrahydrofuran (THF). About half of the resultant polymer dope was applied uniformly onto 40 g of the silica gel obtained in the step (1). After the completion of the application, THF was distilled off under reduced pressure with heating. Distillation time was set to 30 minutes or less. The remaining half of the polymer dope was uniformly applied to the silica gel in the same manner as described above and THF was distilled off under reduced pressure under the same conditions as the first time to obtain the objective amylose tris[(S)-phenylethyl carbamate]-supported separating agent.
(4) Differential Scanning Calorimetry (DSC) of the Separating Agent Prepared in the Step (3)
Differential scanning calorie of the separating agent prepared in the step (3) above was measured by the same technique as in Example 1-(4). FIG. 2 shows the obtained measurement results of DSC.
(5) Preparation of a Packed Column for HPLC from the Prepared Separating Agent
The separating agent having supported the amylose tris[(S)-phenylethyl carbamate] on silica gel prepared in the step (3) above was used as a packing agent to prepare a column for separating enantiomeric isomers in the same manner as in Example 1-(5).
Comparative Example 1
Preparation of an Amylose Tris[(S)-phenylethyl Carbamate]-Supported Separating Agent for Enantiomeric Isomers not having an Exothermic Peak Until Reaching a Decomposition Temperature
(1) Surface Treatment of Silica Gel
Surface treatment was performed in the same manner as in Example 1-(1).
(2) Synthesis of Amylose Tris[(S)-phenylethyl Carbamate]
Synthesis was conducted in the same manner as in Example 1-(2).
(3) Supporting of Amylose Tris[(S)-phenylethyl Carbamate] on Silica Gel
10 g of the amylose tris[(S)-phenylethyl carbamate] obtained in the step (2) was dissolved in 100 ml of tetrahydrofuran (THF). About half of the resultant polymer dope was applied uniformly onto 40 g of the silica gel described in the step (1). After the completion of the application, THF was distilled off under reduced pressure with heating. Distillation time was set to 60 minutes or more. The remaining half of the polymer dope was uniformly applied to the silica gel in the same manner as described above and THF was distilled off under reduced pressure under the same conditions as the first time to obtain the objective amylose tris[(S)-phenylethyl carbamate]-supported separating agent.
(4) Differential Scanning Calorimetry (DSC) of the Separating Agent Prepared in the Step (3)
Differential scanning calorie of the separating agent prepared in the step (3) above was measured in the same manner as in Example 1-(4) FIG. 3 shows the obtained measurement results of DSC.
(5) Preparation of a Packed Column for HPLC from the Prepared Separating Agent
The separating agent having supported the amylose tris[(S)-phenylethyl carbamate] prepared in the step (3) above on silica gel was used as a packing agent to prepare a column for separating enantiomeric isomers in the same manner as in Example 1-(5).
Application Example
By using HPLC columns for separating enantiomeric isomers packed with the separating agents having supported on silica gels the amylose tris[(S)-phenylethyl carbamates] prepared in Examples 1 and 2 having exothermic peaks, and the separating agent having supported on a silica gel the amylose tris[(S)-phenylethyl carbamate] prepared in Comparative Example 1 having no exothermic peak as packing agents, respectively, enantiomeric resolutions of racemic modifications 1 to 3 of the following formulae were performed by a liquid chromatographic method under the following conditions. Table 1 shows the results obtained.
Analysis Conditions
Mobile phase: Hexane/2-propanol=90/10 (v/v)
Flow velocity: 4.7 ml/min
Temperature: 25° C.
Detection: at 254 nm
Equation for calculating the value of separation factor α:α=k 2 ′/k 1 ′ [wherein k 1 ′ and k 2 ′ are each a holding coefficient of enantiomeric isomers and given by the expressions: k 1 ′=(t 1 −t 0 )/t 0 , and k 2 ′=(t 2 −t 0 )/t 0 where t 1 and t 2 are each an elution time of enantiomeric isomers and t 0 is an elution time of tri-tert-butylbenzene]
TABLE 1
Separating
Separating
Separating
agent of Ex. 1
agent of Ex. 2
agent of Com.
(with an
(with an
Ex. 1 (without
exothermic
exothermic
exothermic
peak)
peak)
peaks)
Racemic
k 1 ′ = 0.43
K 1 ′ = 0.53
k 1 ′ = 0.44
modification 1
k 2 ′ = 0.66
K 2 ′ = 0.69
k 2 ′ = 0.54
α = 1.53
α = 1.3
α = 1.22
Racemic
k 1 ′ = 1.29
K 1 ′ = 1.39
k 1 ′ = 1.07
modification 2
k 2 ′ = 3.14
K 2 ′ = 3.02
k 2 ′ = 1.74
α = 2.43
α = 2.18
α = 1.63
Racemic
k 1 ′ = 3.11
K 1 ′ = 3.44
k 1 ′ = 2.86
modification 3
k 2 ′ = 9.17
K 2 ′ = 6.89
k 2 ′ = 4.17
α = 2.95
α = 2
α = 1.46
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A separating agent for enantiomeric isomers has an enantiomerically active polymer compound supported thereon. The polymer compound has an exothermic peak before a decomposition temperature of the polymer compound supported is reached in a differential calorimetric curve obtained in a process of temperature elevation in differential scanning calorimetry (DSC) on the separating agent. Also, disclosed is a method of evaluating asymmetry recognition ability of a separating agent for enantiomeric isomers. The method includes performing the differential scanning calorimetry (DSC) of a separating agent for enantiomeric isomers having supported thereon an enantiomerically active polymer compound to obtain a differential calorimetric curve in a process of temperature elevation therein, and observing presence or absence of an exothermic peak of the polymer compound in the differential calorimetric curve before a decomposition temperature of the supported polymer compound is reached. The evaluation method provides a simpler method for the evaluation of asymmetry recognition ability and thus provides a separating agent for enantiomeric isomers having higher ability of recognizing asymmetry.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a US national phase application of PCT/JP2006/320595, filed Oct. 16, 2006, which claims priority from Japanese Application No. 2006-003292, filed Jan. 11, 2006, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
The present invention relates to a seat mounted to a vehicle, such as an automobile, and including an airbag in its interior.
BACKGROUND ART
Hitherto, various airbag devices, such as a driver airbag device that is inflated for deployment towards a driver from a rotational center of a steering wheel at a driver's seat, and a passenger airbag that is inflated for deployment towards a passenger's seat from an instrument panel, are used for restraining the body of an occupant when, for example, an automobile collides.
In recent years, an airbag device has already been proposed (refer to, for example, Japanese Unexamined Patent Application Publication No. 2002-37011) to overcome the following. That is, when a serious accident that applies a large external force to an automobile occurs, for example, overturning of a vehicle body, resulting from a collision, or falling of a heavy object, such as a tree, a shock may be due to the shock generated during the serious accident.
In the aforementioned related art, the following basic structure is discussed. That is, an airbag, formed of a bag member in which base cloths are joined to each other, is accommodated in a backrest (or a headrest) of a seat of a vehicle, and the airbag is inflated by supplying a pressure fluid from an inflator in an emergency, to deploy the airbag towards the upper side of the head of an occupant.
SUMMARY OF THE INVENTION
In optimizing an airbag device provided in the seat, it is necessary to increase stability and deployment speed in an inflation/deployment performance.
It is an object of the present invention to provide an effective technology that increases deployment speed and stability in an inflation/deployment performance of an airbag device provided in a seat.
To this end, a first invention provides a seat comprising a backrest covered with a skin cloth and including a cleavage portion at a predetermined portion of the skin cloth; an airbag formed of a bag member in which a base cloth is joined, the airbag being provided in an interior of the backrest so as to be deployed towards an upper side of the head of an occupant as a result of cleaving the cleavage portion during inflation; and a cleavage restricting member provided at the skin cloth so as to restrict a cleavage of the skin cloth at a portion other than the cleavage portion.
When supplying a pressure fluid to the airbag, first, inflation of the airbag is started in the interior of the backrest, and, during the inflation, the skin cloth that covers the backrest is pressed to cleave the cleavage portion. Then, the airbag is inflated towards the outside of the backrest through the opened cleavage portion, and is deployed towards the upper side of the head of the occupant. The airbag is formed so as to deployed at a predetermined disposition and in a predetermined order in an inflation/deployment process thereof, and is accommodated in the interior of the backrest by being folded in such a way as to be capable of being predeterminately deployed. The cleavage portion is provided with a proper length and at a proper position so as to be capable of being predeterminately deployed.
The present invention includes the aforementioned cleavage restricting member, so that, when the airbag cleaves the cleavage portion in the inflation/deployment process, it is possible to restrict excess cleavage of the skin cloth at portions other than the cleavage portion. Therefore, the airbag can be deployed in accordance with the predetermined deployment operations, that is, the stability of the inflation/deployment performance of the airbag device can be increased.
In addition, since the pressing force by the airbag can be concentrated only at the cleavage portion, the cleavage portion can be quickly cleaved, that is, the deployment speed of the inflation/deployment performance of the airbag device can be increased.
According to a second invention, in the first invention, an end of the cleavage restricting member is provided so as to substantially match an end of the cleavage portion.
This makes it possible to restrict tearing, serving as a source of excessive cleavage, in an end of the cleavage portion.
According to a third invention, in either the first invention or the second invention, the cleavage restricting member is provided near an/the end of the cleavage portion.
This makes it possible to restrict the occurrence of tearing in, in particular, an end of the cleavage portion that tends to become a source of excessive cleavage.
According to a fourth invention, in any one of the first to third inventions, the cleavage restricting member is provided at a stitch portion of the skin cloth.
This makes it possible to restrict cleavage in, in particular, the stitch portion of the skin cloth that tends to be cleaved.
According to a fifth invention, in any of the first to fourth inventions, a damping layer is provided at an inner side of the skin cloth, and the cleavage restricting member is provided at the damping layer.
This makes it possible to also restrict cleavage of the damping layer, so that the absorption performance of shock applied to the occupant can be maintained, thereby making it possible to increase safety.
According to the present invention, it is possible to increase deployment speed and stability in an inflation/deployment performance of an airbag device provided in a seat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view for when a seat according to an embodiment of the present invention is installed in an automobile.
FIG. 2 is a perspective view showing a structure in which the airbag device of the seat according to the present invention is secured to a seat frame.
FIG. 3 is an exploded perspective view of the airbag device, showing the securing structure shown in FIG. 2 in more detail.
FIG. 4 is a perspective view of the entire structure of an airbag in a completely inflated and deployed state as seen obliquely from the back.
FIG. 5 is an enlarged perspective view of the vicinity of a tear line of a backrest as seen obliquely from the front side.
FIG. 6 is a sectional view of the backrest taken along line VI-VI′ of FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will hereunder be described with reference to the drawings.
FIG. 1 is a schematic side view of when a seat 1 according to an embodiment of the present invention is installed in an automobile, with FIG. 1( a ) showing a normal state and FIG. 1( b ) showing a state when an airbag is being inflated. In the following description, a forward direction is a direction in which an occupant 2 seated on the seat 1 faces the front, and a backward direction is a direction opposite thereto.
In FIG. 1 , the occupant 2 is seated on the seat 1 . The seat 1 includes a sitting portion 1 A, and a backrest 1 B that protrudes upward from the sitting portion 1 A. A headrest 1 C is mounted to the top portion of the backrest 1 B.
In the seat 1 , an airbag device 10 for restraining a head 2 A of the occupant 2 when, for example, a vehicle body is overturned due to an accident is installed in the interior of the backrest 1 B. The airbag device 10 includes an airbag 11 , a retainer 12 , and an inflator 1 . The airbag 11 comprises a bag member, formed by sewing and connecting a first base cloth 35 and a second base cloth 36 (refer to FIG. 4 ) to each other, and is provided so as to be deployed towards the upper side of the head 2 A of the occupant 2 when the airbag 11 is inflated. The retainer 12 accommodates the airbag 11 in a folded state. The inflator 13 supplies gas (pressure fluid) for inflating and deploying the airbag 11 (refer to FIGS. 2 and 3 ).
The seat 1 includes in its interior a seat frame (strength supporting member) 14 including side plates 14 A (refer to FIG. 2 ) and a cross member 14 B (refer to FIG. 2 ), and forming the skeleton of the seat 1 . The retainer 12 and the inflator 13 are provided at the seat frame 14 (described in detail below). The entire sitting portion 1 A and the entire backrest 1 B of the seat 1 are covered with a skin cloth 1 D. A tear line (cleavage portion) 41 , which tends to tear compared to other portions, is formed by a perforated line along a horizontal straight line in a front top portion of the skin cloth 1 D covering the backrest 1 B. A foam layer 42 , which is a damping layer, is provided at the inside surface (at the inner side of the backrest 1 B) of the skin cloth 1 D. Further, a reinforcement cloth (cleavage restricting member) 43 is adhered around the tear line 41 at the inside surface of the foam layer 42 (refer to FIGS. 5 and 6 ).
Although not shown, various sensors that detect the occurrence of (or prediction of the occurrence of) overturning or collision (including side collision) of an automobile are provided in the automobile to which the airbag device 10 is installed. On the basis of detection signals from these sensors, an inflator controlling circuit (not shown) starts an initiator (not shown) of the inflator 13 .
As shown in FIG. 1( a ), in a normal state, the airbag 11 is accommodated in a folded state in the retainer 12 . In contrast, when, for example, the automobile collides or is overturned as mentioned above, the sensors detect the collision or the overturning of the automobile, and a starting signal is input from the inflator controlling circuit to the initiator of the inflator 13 , so that, as shown in FIG. 1( b ), an upper deployment portion 38 of the airbag 11 is inflated, and is deployed between a roof 3 of the automobile and the head 2 A of the occupant 2 . At this time, the airbag 11 bulges outward after the tear line 41 , formed in the skin cloth 1 D of the backrest 1 B, is cleaved, and is deployed towards the upper side of the head 2 A of the occupant 2 . Then, the airbag 11 is inflated so that the head 2 A of the occupant 2 is pushed forward by the operation of a lower deployment portion 37 (refer to FIG. 1) of the airbag 11 , causing the head 2 A of the occupant 2 to bend forward, thereby making it possible to reduce a load on the neck. The consecutive deployment operations of the airbag 11 are set so that each portion of the airbag 11 is set so as to be inflated and deployed in a predetermined order and disposition. Accordingly, the shape of and the way in which the airbag 11 is folded in the retainer 12 are considered in accordance with this setting.
FIG. 2 is a perspective view showing a structure in which the airbag device 10 is secured to the seat frame 14 . FIG. 3 is an exploded perspective view of the airbag device 10 , showing in more detail the aforementioned securing structure.
In FIGS. 2 and 3 , the seat frame 14 includes the pair of side plates 14 A and 14 A, provided at respective sides in a vehicle-width direction (that is, respective sides in a horizontal direction in FIG. 2 ) in the interior of the backrest 1 B of the seat 1 , and the cross member 14 B, extending between the side plates 14 A and 14 A along substantially the vehicle-width direction and connecting the side plates 14 A and 14 A to each other. The side plates 14 A and 14 A and the cross member 14 B are each provided in the interior of the backrest 1 B of the seat 1 . Although not particularly illustrated, the seat frame 14 includes a base plate provided in the interior of the sitting portion 1 A.
A gas supply port 11 a , connected to the inflator 13 through a pipe member 20 , and mounting portions 11 b and 11 b , positioned at respective sides of the gas supply port 11 a , are provided at a base-end side (inflator side, lower side in FIG. 3 ) of the airbag 11 . Two bolt holes 22 each for inserting mounting bolts 21 a for securing the airbag 11 and the retainer 12 to each other are formed at the mounting portions 11 b and 11 b, respectively. Mounting portions 12 a and 12 b, having bolt holes 24 for inserting mounting bolts 23 for securing the retainer 12 , are formed at respective sides in the vehicle-width direction of the retainer 12 . A mounting portion 12 c, similarly having bolt holes 25 at positions corresponding to the positions of the bolt holes 22 of the airbag mounting portions 11 b , is provided below (at the inflator side, lower side in FIG. 3 ) the mounting portions 12 a and 12 b.
While the airbag 11 is folded and accommodated in the retainer 12 , the plurality of mounting bolts 21 a (four in the embodiment) are inserted into the bolt holes 25 of the retainer mounting portion 12 c, the bolt holes 22 of the airbag mounting portions 11 b , and bolt holes 27 , formed in mounting plates 26 at positions corresponding to the bolt holes 22 of the airbag mounting portions 11 b ; and are fastened with nuts 21 b . This secures the airbag 11 to the retainer 12 while the airbag 11 is in a folded state. The mounting bolts 23 (two in the embodiment) are inserted into the bolt holes 24 of the retainer mounting portions 12 a and 12 b , and are, then, fastened to fastening holes (not shown) provided in the cross member 14 B. This secures the retainer 12 , in which the airbag 11 is accommodated in a folded state, to the cross member 14 B.
The pipe member 20 is, for example, a metallic pipe that is bent at a plurality of locations (two locations in the embodiment), and is provided below the retainer 12 . The pipe member 20 and the airbag 11 are connected to each other by covering a bag-side end portion 20 a of the pipe member 20 with the gas supply port 11 a of the airbag 11 , and by caulking and securing them to each other with, for example, a metallic clamp band 30 . The pipe member 20 and the inflator 13 are connected to each other by covering a top end portion 13 a of the inflator 13 with a connection portion 20 b, provided at an inflator-side end portion of the pipe member 20 , and by adhering (or, for example, welding) them to each other. Accordingly, the airbag 11 and the inflator 13 are connected to each other through the pipe member 20 .
The inflator 13 is provided further below the pipe member 20 , and is mounted to one of the side plates 14 A (on the right side in the vehicle-width direction in the embodiment) with a mounting member 31 . The mounting member 31 includes a pair of mounting plates 31 A and 31 B that support the inflator 13 as a result of being placed on both sides of the inflator 13 . These mounting plates 31 A and 31 B are connected to each other using rivets by inserting a plurality of rivets 31 a (four in the embodiment), formed at the mounting plate 31 A, into a plurality of rivet holes 31 b (four in the embodiment), formed in corresponding positions of the mounting plate 31 B, so that the mounting plates 31 A and 31 B are secured to each other as a result of being placed on both sides of the inflator 13 . A mounting portion 31 c is formed on one side (on the right side in the vehicle-width direction) of the mounting plate 31 A so as to be bent by substantially 90 degrees. A plurality of mounting bolts 32 (two in the embodiment) are inserted into respective bolt holes 33 , formed in the mounting portion 31 c , and are fastened to respective fastening holes (not shown) of the side plate 14 A, so that the mounting member 31 is secured to the side plate 14 A. As a result, the inflator 13 is secured to the side plate 14 A through the mounting member 31 .
The initiator (not shown) of the inflator 13 and the aforementioned inflator controlling circuit (not shown) are connected to each other with a cable 34 , so that an ignition control of the inflator 13 is carried out through the cable 34 .
FIG. 4 is a perspective view of the entire structure of the airbag 11 in a completely inflated and deployed state as seen obliquely from the back.
In FIG. 4 , the airbag 11 comprises the bag member formed by sewing and connecting the first base cloth 35 and the second base cloth 36 as mentioned above. When the airbag 11 is in an inflated and deployed state as illustrated, the airbag 11 has a shape in which the lower deployment portion 37 and the upper deployment portion 38 are integrally formed. First, pressure fluid is supplied to the gas supply port 11 a from the inflator 13 , so that the lower deployment portion 37 is inflated and deployed at a side opposing the back of the head of the occupant, causing the head of the occupant to be bent forward. Then, the upper deployment portion 39 is inflated and deployed towards the upper side of the head of the occupant.
FIG. 5 is an enlarged perspective view of the vicinity of the tear line 41 of the backrest 1 B as seen obliquely from the front side. FIG. 6 is a sectional view of the backrest 1 B taken along line VI-VI′ of FIG. 5 . To simplify the illustrations, the headrest is not shown in FIGS. 5 and 6 .
In FIGS. 5 and 6 , as mentioned above, the entire backrest 1 B is covered with the skin cloth 1 D, and the tear line 41 (a dotted line portion in FIG. 6 ), which tends to tear compared to other portions, is formed, in this embodiment, along a horizontal straight line in the front top portion (left front side in FIG. 5 ) of the backrest 1 B among the portions of the skin cloth 1 D by, for example, a perforated line. The length and disposition of the tear line 41 are set to a length and a disposition that allow the aforementioned predetermined deployment to be properly performed when it is pressed and cleaved at a suitable stage in an inflation/deployment process of the airbag 11 and, then, the airbag 11 bulges outward from the completely opened tear line 41 . An ornamental cloth 1 Da, in which design (esthetics) is considered, is sewed to the skin cloth 1 D at the front side of the backrest 1 B. A stitch portion 45 reaches the tear line 41 . The stitch portion 45 is sewed so that the skin cloth 1 D and the foam layer 42 at the inner side thereof are joined to each other.
The foam layer 42 , which is a damping layer that is formed of, for example, a sponge sheet and that absorbs, for example, shock applied to an occupant, is provided at the inside surface (at the inner side of the backrest 1 B) of the skin cloth 1 D. Further, the reinforcement cloth 43 (a broken line portion in FIG. 6 ), formed of a material that has a high tensile strength and that does not break easily, is adhered to around the tear line 41 at the inside surface of the foam layer 42 . The foam layer 42 and the reinforcing cloth 43 are integrally provided with the inside surface of the skin cloth 1 D. Slits 44 whose lengths and locations match those of the tear line 41 of the slit cloth 1 D are formed at both the foam layer 42 and the reinforcing cloth 43 .
Open ends of the slit 44 of the reinforcing cloth 43 are adhered, for example, by using an adhesive or by welding to the inside surface of the skin cloth 1 D so as to match open ends of the tear line 41 that has been cleaved. Since the length (length in the vehicle-width direction) of the entire reinforcing cloth 43 is sufficiently longer than that of the tear line 41 , the reinforcing cloth 43 is adhered to where it overlaps the entire tear line 41 , including both ends 41 a, and the stitch portion 45 at the vicinity of the tear line 41 . The reinforcing cloth 43 increases breakage strength of the foam layer 42 and the skin cloth 1 D at the vicinity of the tear line 41 while maintaining breakage property at the tear line 41 .
The seat 1 according to the embodiment having the above-described structure provides the following advantages.
That is, in the seat 1 according to the embodiment, providing the reinforcing cloth 43 can restrict excessive cleavage of the skin cloth 1 D at portions other than the tear line 41 when the airbag 11 cleaves the tear line 41 in the inflation/deployment process of the airbag 11 . Therefore, the airbag 11 can be deployed in accordance with the deployment operations carried out on the basis of the predetermined order and disposition. That is, the stability of the inflation/deployment performance of the airbag device 10 can be increased.
Since the pressing force by the airbag 11 can be concentrated at only the tear line 41 , the tear line 41 can be quickly cleaved. That is, the deployment speed in the inflation/deployment performance of the airbag device 10 can be increased.
A reinforcing cloth 43 may be provided at locations other than where the reinforcing cloth 43 overlaps the entire tear line 41 and the vicinity thereof unlike in the embodiment. For example, a reinforcing cloth 43 may be provided at a location far away from the tear line 41 where the airbag 11 may press the skin cloth 1 D (foam layer 42 ) in a concentrated manner and cause it to be cleaved during the inflation and deployment. Even in this case, escape of excessive pressing force of the airbag 11 caused by cleaving portions other than the tear line 41 can be restricted, so that the deployment speed and stability in the inflation/deployment performance of the airbag device 10 can be increased.
In the embodiment, by providing the open ends of each slit 44 of the reinforcing cloth 43 so as to substantially match the open ends of the tear line 41 , the production of a cleavage, which is a source causing progression of excessive cleavage at the open ends of the tear line 41 , can be restricted.
In addition, in the embodiment, providing the reinforcing cloth 43 near the ends 41 a of the tear line 41 can restrict the production of a cleavage at the ends 41 a of the tear line 41 , which tends to be a source causing excessive cleavage.
Further, in the embodiment, providing the reinforcing cloth 43 at the stitch portion 45 of the skin cloth 1 D makes it possible to restrict a cleavage at, in particular, the stitch portion 45 of the skin cloth 1 D, which has low rupture strength and which tends to be cleaved.
In the embodiment, providing the reinforcing cloth 43 at the inside surface of the foam layer 42 makes it possible to also restrict a cleavage of the foam layer 42 . Therefore, it is possible to maintain the capability of absorbing shock applied to an occupant in, for example, a collision of a vehicle, and to increase stability.
Although, in the embodiment, the reinforcing cloth 43 , formed of a cloth material and serving as a cleavage restricting member provided at portions other than the tear line 41 , is provided, the present invention is not limited thereto. For example, a reinforcing plate, formed of a material having a high strength, such as a metal or ceramic, may be provided, for example, in particular, near the ends 41 a of the tear line 41 whose rupture strength needs to be increased.
Although, in the embodiment, the structure in which the airbag device 10 is provided in the interior of the backrest 1 B is described, the prevent invention can be applied to a structure in which the airbag device 10 is provided in the interior of the headrest 1 C covered with the skin cloth 1 D, and similar advantages can be provided.
The specific structure according to the above-described embodiment does not, strictly speaking, limit the content of the present invention. The details can obviously be variously changed in accordance with the gist of the present invention.
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To provide a seat that enhances the stability and expansion speed with respect to the inflation expansion performance of airbag unit disposed thereinside. In one form, a seat is provided comprising a backrest part covered at its entirety with top fabric material and, at a given region of the top fabric material, it is furnished with tear line; an airbag constituted of a bag consisting of two basis fabrics joined together and disposed within the backrest part so as to at the time of inflation, cleave the tear line and expand over the head of driver or passenger; and reinforcing fabric disposed on the top fabric material so as to inhibit any cleavage of the top fabric material at regions other than the tear line.
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This is a continuation of application Ser. No. 07/304,986, filed on Jan. 31, 1989, abandoned.
FIELD OF THE INVENTION
The present invention relates to refastenable mechanical fastening systems, and more particularly to the prong of a mechanical fastening system, and still more particularly to a prong having an improved engaging means which more effectively engages to a complementary receiving surface.
BACKGROUND OF THE INVENTION
Releasably securable mechanical fastening systems are well known in the art. Such fastening systems are commonly used to secure two articles together. The fastening system has a substrate and at least one prong comprising a base, shank and engaging means. The prong is joined to the substrate at the base. Contiguous with the base of the prong is the shank, which projects outwardly from the base and substrate. Joined to the shank in spaced relation from the substrate is the engaging means. The engaging means projects laterally from the periphery of the shank and has a surface facing towards the substrate.
Securing of the two articles is accomplished by the engaging means intercepting fibers, strands, or induced localized deformations of a complementary receiving surface. When secured together, the physical obstruction, and resulting mechanical interference, between the engaging means of the fastening system and the fibers, strands or localized deformations of the receiving surface prevents release of the two articles until applied separation forces, such as peel and shear, exceed the resistance of the fastening system and receiving surface to such forces.
One of more significant factors determining the resistance to separation forces the fastening system and receiving surface can withstand without release and separation occurring is the included angle of the engaging means. The included angle is the angular deviation of the engaging means from the perpendicular to the substrate which passes through the center of the base of the prong.
A plethora of engaging means are used with presently known refastenable mechanical fastening systems. For example, one well known type of engaging means incorporates hemispherically shaped heads with a planar surface oriented towards the substrate and are typically referred to as being "mushroom-shaped." Such engaging means are generally illustrated in U.S. Pat. No. 4,216,257, issued Aug. 5, 1980 to Schams et al., U.S. Pat. No. 4,338,800, issued July 13, 1982 to Matsuda and European Patent Application Publication No. 0,276,970, filed Jan. 26, 1988 by the Procter & Gamble Company in the name of Scripps. In such embodiments, however, the engaging means have included angles from about 90° to about 165°, depending on the orientation of the stem of the prong relative to the substrate.
Another type of mechanical fastening system utilizes prongs which are cut from a loop and are hook shaped, somewhat resembling a candy cane, as illustrated in U.S. Pat. Nos. 3,083,737, issued Apr. 2, 1963 to de Mestral, 3,154,837, issued Nov. 3, 1964 to de Mestral and 3,943,981, issued Mar. 16, 1976 to De Brabander. Hook type fastening systems generally have included angles of about 180° or less, depending upon where the loop used to form the fastening system is cut. Hook-shaped fastening means produced by methods other than the cut loop system are disclosed in U.S. Pat. Nos. 3,629,032, issued Dec. 21, 1971 to Erb and 3,594,863, issued July 27, 1971 to Erb. These fastening means also have included angles of about 180°.
Various other structures are also taught as suitable for use as the engaging means of the fastening system. For example, U.S. Pat. Nos. 3,550,837, issued Dec. 29, 1970 to Erb, 3,708,833, issued Jan. 9, 1973 to Ribich et al. and 4,454,183, issued June 12, 1984 to Wollman disclose alternative types of engaging means, none of which have an included angle of greater than 180°.
It is an object of this invention to provide a fastening system which more securely engages or intercepts the strands or fibers of the receiving surface to resist applied separation forces. It is also an object of this invention to provide a fastening system having an engaging means with an included angle substantially greater than about 180° and a reentrant segment.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a fastening system for attaching to a complementary receiving surface. The fastening system has a substrate and at least one prong having a base, shank and engaging means. The prong is joined to the substrate at the base. The shank of the prong is contiguous with and projects longitudinally outwardly from the base of the prong and the substrate. The engaging means of the prong is joined to the shank of the prong and laterally projects radially outwardly from the periphery of said shank. The engaging means has an included angle substantially greater than about 180° and a reentrant segment.
In one execution, the engaging means has a first laterally projecting segment and a reentrant second laterally projecting segment. The first laterally projecting segment projects radially outwardly beyond the periphery of the shank. The laterally projecting reentrant second segment projects towards the shank of the prong, so that the engaging means defines a free space between the first segment and the reentrant segment. A longitudinal projection originating from and within the free space and oriented towards and generally perpendicular to the plane of the substrate intercepts one of the lateral segments.
In a second execution, the engaging means has first, second and third segments. The first segment laterally projects radially outwardly beyond the periphery of the prong. The second segment is joined to the first segment and longitudinally projects relative to the first segment. The third segment is joined to the second segment and laterally projecting towards the shank. A free space is defined between the segments of the engaging means. A longitudinal projection originating from and within the free space and oriented towards and generally perpendicular to the plane of the substrate intercepts one of the lateral segments.
BRIEF DESCRIPTION OF THE DRAWINGS
While the Specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the invention will be better understood from the following Specification taken in conjunction with the associated drawings in which like elements are designated by the same reference numeral and:
FIG. 1 is a perspective view of a fastening system of the present invention:
FIG. 2 is a side elevational profile view of a prong of the fastening system of the present invention having an engaging means with an included angle of about 270°;
FIG. 3 is a side elevational profile view of a prong having an engaging means with an included angle of about 180°;
FIG. 4 is a side elevational profile view of a prong of the fastening system of the present invention having an engaging means with an included angle of about 315°;
FIG. 5 is a side elevational profile view of a prong of the fastening system of the present invention having an engaging means with a first segment and a reentrant second segment;
FIG. 6 is a side elevational profile view of a prong of the fastening system of the present invention having an engaging means with a first segment, a second segment and a reentrant third segment; and
FIG. 7 is a side elevational schematic view of one apparatus which can be used to manufacture the fastening system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The fastening system 20 of the present invention comprises at least one prong 22, and preferably an array of prongs 22, joined to a substrate 24 in a predetermined pattern as shown in FIG. 1. Each prong 22 has a base 26, shank 28, and engaging means 30. The bases 26 of the prongs 22 contact and adhere to the substrate 24, and support the proximal ends of the shanks 28. The shanks 28 project outwardly from the substrate 24 and bases 26. The shanks 28 terminate at a distal end which is joined to an engaging means 30. The engaging means 30 radially project laterally beyond the shanks 28 in one or more directions and may resemble a hook-shaped tine. As used herein, the term "lateral" means having a vector component generally parallel to the plane of the substrate 24 at the principal prong 22 under consideration. The projection of an engaging means 30 beyond the shank 28 periphery in a lateral direction allows the engaging means 30 to be secured to a complementary receiving surface (not shown).
The fastening system 20 is secured to a complementary receiving surface. As used herein, the term "receiving surface" to which the engaging means 30 of the fastening system 20 are secured refers to any plane or surface which will interact with the engaging means such that the engaging means may not be readily separated from the receiving surface. The receiving surface may have an exposed face with tightly spaced openings complementary to the engaging means 30 and defined by one or more strands or fibers. Alternatively, the exposed face may be capable of localized elastic deformation so that the engaging means 30 may become entrapped and not withdrawn without interference.
Referring to FIG. 2 to examine the components of the fastening system 20 in more detail, the substrate 24 of the fastening system 20 is preferably a sheet of material to which the prongs 22 are attached in a desired pattern. The "substrate" is any exposed surface to which one or more prongs 22 are joined. The substrate 24 should be strong enough to preclude tearing and separation between individual prongs 22 of the fastening system 20. In addition, the substrate 24 is manufactured from a material which is capable of being joined to the prongs 22 and which is further capable of being joined to an article to be secured as desired by a user. As used herein the term "join" refers to the condition where a first member, or component, is affixed, or connected to a second member or component, either directly; or indirectly, where the first member or component is affixed or connected to an intermediate member, or component which in turn is affixed, or connected, to the second member or component. The association between the first member, or component, and the second member, or component, is intended to remain for the life of the article.
The substrate 24 should also be capable of being rolled, to support conventional manufacturing processes, flexible so that the substrate 24 may be bent or flexed in a desired configuration, and able to withstand the heat of the liquid prongs 22 being deposited thereon without melting or incurring deleterious effects until such prongs 22 freeze. The substrate 24 should also be available in a variety of widths. Suitable substrates 24 include knitted fabric, woven materials, nonwoven materials, films, particularly polyolefinic films and preferably kraft paper. White kraft paper having a basis weight of about 0.08 kilograms per square meter (50 pounds per 3,000 square feet) has been found suitable.
The base 26 of the prong 22 comprises the plane of attachment to the substrate 24 and is contiguous with the proximal end of the shank 28. As used herein, the term "base" refers to that portion of the prong 22 which is in direct contact with the substrate 24 and supports the shank 28 of the prong 22. The shape of the footprint of the base 26 on the substrate 24 is not critical, and may be amplified in any direction to provide a greater peel strength in that direction. As used herein, the term "footprint" refers to the planar contact area of the base 26 on the substrate 24. A generally circular shaped footprint is preferred. For the embodiment described herein, a footprint of generally circular shape and approximately 0.76 millimeters to 1.27 millimeters (0.030 to 0.050 inches) in diameter is suitable.
The shank 28 is contiguous with the base 26 and projects outwardly from the base 26 and substrate 24. As used herein, the term "shank" refers to that portion of the prong 22 which is contiguous with the base 26 and intermediate the base 26 and the engaging means 30. The shank 28 provides longitudinal spacing of the engaging means 30 from the substrate 24. As used herein, the term "longitudinal" means in a direction having a vector component away from the substrate 24, which direction increases the perpendicular distance to the plane of the substrate 24 at the base 26 of the prong 22, unless otherwise specified to be a direction having a vendor component towards such plane of the substrate 24.
Associated with each prong 22 is a longitudinal axis 32. As used herein, the term "longitudinal axis" refers to an imaginary line generally centered at the footprint of the base 26 and laterally and longitudinally projecting through the distal end of the shank 28 to the tip 34 of the engaging means 30. The prong base 26, shank 28 and engaging means 30 are generally concentric with the longitudinal axis 32 if the prong 22 cross section is of a regular shape. If the cross section of the prong 22 is irregularly shaped, the longitudinal axis 32 is disposed at the centroid of any cross section.
The "origin" of the longitudinal axis 32 is the point of intersection between the longitudinal axis 32 and the base 26, and is typically within the footprint of the base 26. Specifically, the origin 36 is the center of the smallest circle which circumscribes the footprint of the base 26.
After the origin 36 of the prong 22 has been found, the origin 36 may be used to determine the profile view of the prong 22. The "side view" is any direction radially directed towards the longitudinal axis 32 of the shank 28, particularly the perpendicular which passes through the origin 36, and parallel to the plane of the substrate 24. The "profile view" of the prong 22 is one of two particular side views and found as follows. The prong 22 is visually inspected from the side views such that the direction having the maximum lateral projection 38 becomes apparent. The "lateral projection" is the distance taken laterally and parallel to the plane of the substrate 24 from the origin 36 of the shank 28, to the projection of the furthest laterally remote point on the prong 22 visible in such view when such point is longitudinally and perpendicularly projected downward to the plane of the substrate 24.
It will be apparent to one skilled in the art that the maximum lateral projection 38 is that projection from the origin 36 to the outer periphery of the shank 28 or engaging means 30. The side view of the prong 22 which maximizes the lateral projection 38 is the profile view of such prong 22. It will also be apparent to one skilled in the art that if the fastening system 20 is produced by the process described below, the maximum lateral projection 38 is generally oriented in the machine direction and, hence, the profile view is generally oriented in the cross-machine direction. The side elevational view shown in the figures is one of the profile views of the prong 22. It will be further apparent to one skilled in the art that there is another profile view, generally 180° opposite from the profile view shown (so that the maximum lateral projection 38 is oriented towards the left of the viewer). Either of the two profile views is generally equally well suited for the procedures and usages described hereinbelow.
The engaging means 30 of the prong may have a greater lateral projection 38 than the prong shank 28, or vice-versa, as desired. The engaging means 30 preferably may have a reentrant curve and longitudinally approximate the substrate 24 at the prong base 26 or a location laterally spaced from the prong base 26.
The engaging means 30 forms an included angle θ relative to the plane of the substrate 24. As used herein, the term "included angle θ" refers to the angular deviation between the extension of the perpendicular to the plane of the substrate 24 which passes through the origin 36 of base 26 and the projection of the longitudinal axis 32 through the tip 34 of the engaging means 30, as seen when the prong 22 is viewed in profile. The phrase "projection of the longitudinal axis" refers to the imaginary continuation of the longitudinal axis 32 in a straight line through the tip 34 of the engaging means 30 is such axis were continued at the angle present at the tip 34 of the engaging means 30. Various included angles θ are illustrated by the examples shown in Table I;
TABLE 1______________________________________Angle Description______________________________________θ = 0° The projection of the longitudinal axis 32 is perpendicular to and directed away from the plane of the substrate 24 and lies coincident with the perpendicular which passes through the origin 36.0° ≦ θ ≦ 90° θ equals the angle between the projection of the longitudinal axis 32 and the outwardly oriented perpendicular which passes through the origin 36.θ = 90° The projection of the longitudinal axis 32 is parallel to the plane of the substrate 24 and oriented radially away from the perpendicular which passes through the origin 36.90° ≦ θ ≦ 180° θ equals 90° plus the deviation of the projection of the longitudinal axis 32 below the plane tangent to the highest elevation of the longitudinal axis 32 and parallel to the plane of the substrate 24.θ = 180° The projection of the longitudinal axis 32 is perpendicularly oriented towards the plane of the substrate 24 and laterally offset from the origin 36.180° ≦ θ ≦ 270° θ equals 180° plus the deviation of the projection of the longitudinal axis 32 from the perpendicular (either the perpendicular tangent to the tip 34 of the longitudinal axis 32 and directed towards the plane of substrate 24 or the perpendicular through the origin 36 and oriented away from the plane of the substrate 24).Θ = 270° The projection of the longitudinal axis 32 is parallel to the plane of the substrate 24 and laterally oriented towards the perpendicular which passes through the origin 36.270° ≦ θ ≦ 360° θ equals 270° plus the deviation of the projection of the longitudinal axis 32 from the plane of the substrate 24.θ = 360° The projection of the longitudinal axis 32 is perpendicular to the plane of the substrate 24, longitudinally outwardly oriented and laterally offset from the perpendicular which passes through the origin 36.θ ≧ 360° θ is found according to the methods discussed above, and 360° is added to the angle.______________________________________
It is to be recognized that as the included angle θ of the engaging means 30 increases, i.e. departs further from the perpendicular to the plane of the substrate 24, it will become increasingly difficult for the engaging means 30 to intercept the strands or fibers of the receiving surface. However, a strand entangled in an engaging means 30 having a relatively greater included angle θ is less likely to migrate out of or work free from the engaging means 30 during use.
For any of the embodiments described herein, the engaging means 30 has an included angle θ preferably substantially greater than about 180°. More preferably, the included angle is substantially greater than about about 180° and less than about 360°, even more preferably between about 230° and about 310°, and most preferably about 270°. An included angle θ greater than about 195° is considered to be substantially greater than about 180°.
The engaging means 30 has a reentrant segment 31 if the included angle θ of the engaging means 30 is substantially greater than about 180°. The "reentrant segment" is that portion of the engaging means 30 which extends beyond an included angle θ substantially greater than about 180°. Thus, if the engaging means 30 is truncated to have an included angle θ of about 180°, the reentrant segment 31 is that portion of the engaging means 30 intermediate the plane of truncation and the tip 34. The reentrant segment 31 is directed laterally towards the shank 28, but it will be apparent that the reentrant segment 31 need not be radially oriented towards the perpendicular which passes through the origin 36.
The prong 22 illustrated in FIG. 2 is a particularly preferred embodiment having an engaging means 30 which forms an included angle θ of about 270°. The prong illustrated in FIG. 3 has a relatively lesser included angle θ which is about 180°. The prong 22 illustrated in FIG. 4 has a relatively greater included angle θ of about 315°.
The prongs 22 of the fastening system 20 of the present invention may be made of any of the materials well known and commonly used in the art including plastics, such as thermoplastics. Hot melt adhesive thermoplastics are particularly well suited to the fastening system 20 of the present invention, particularly if the fastening system 20 is manufactured according to the process described hereinbelow. Polyester and polyamide hot melt adhesives have been found particularly suitable. A polyester hot melt adhesive marketed by the Bostik Company of Middleton, Mass., under Model No. 7199 has been found to work well. A polyamide hot melt adhesive marketed by the Henkel Company of Kankakee, Ill. under the tradename Macromelt 6300 has been found to work well.
Instead of being arcuately shaped, as illustrated in the figures, the prongs 22 may have more abrupt discontinuities or be segmented. In one such embodiment, illustrated in FIG. 5, the engaging means 30 may be schematically thought of as having two segments, a first segment 30a and a reentrant second segment 30b. The first segment 30a projects laterally and radially from the perpendicular which passes through the origin 36. The first segment 30a may be colinear with the shank 28, providing it is nonperpendicularly oriented relative to the plane of the substrate. If the first segment 30a and shank 28 are colinear, it is not necessary that a clear demarcation be apparent between the shank 28 and the first segment 30a of the engaging means 30, or that the terminus of the shank 28 or the first segment 30a be determinable at all. Whether or not the first segment 30a of the engaging means 30 is colinear with the shank 28, the first segment 30a projects radially outwardly beyond the periphery of the shank 28 and is joined to a laterally projecting reentrant second segment 30b.
The reentrant second segment 30b laterally projects back towards the shank 28 of the prong 22 and particularly towards the perpendicular which passes through the origin 36. The tip 34 of the reentrant second segment 30b of the engaging means 30 is laterally closer to the perpendicular which passes through the origin 36 than is the end of the second segment 30b which is joined to the first lateral segment 30a. It will be apparent, however, that the second lateral segment 30b may be longitudinally spaced towards (as shown) or away from (not illustrated) the plane of the substrate 24, relative to the first lateral segment 30a.
Either of the segmented arrangements defines a free space between the first lateral segment 30a and the reentrant lateral segment 30b. As used herein, the term "free space" refers to a plane, not parallel to and preferably generally perpendicular to the plane of the substrate 24, and at least partially bounded by the engaging means 30 of the prong 22. A longitudinal projection originating within the free space and oriented towards and generally perpendicular to the plane of the substrate 24 will intercept one of the lateral segments 30a or 30b which defines the free space, particularly the lateral segment 30a or 30b longitudinally closer towards the plane of the substrate 24. It will be apparent to one skilled in the art that the arcuate embodiments shown in FIGS. 2-4 also define a free space.
Alternatively, as illustrated in FIG. 6 the engaging means 30 may be schematically thought of as having three distinguishable segments 30a, 30b and 30c. The first segment 30a laterally projects radially outwardly beyond the periphery of the shank 28. The distal end of the first segment 30a is joined to a second segment 30b which projects longitudinally relative to the first segment 30a and the plane of the substrate 24. The second segment 30b may project longitudinally away from the plane of the substrate 24 or, preferably, longitudinally towards the plane of the substrate 24. The distal end of the second segment 30b is joined to a reentrant third segment 30c which laterally projects back towards the prong shank 28 so that the tip 34 of the third segment 30c is laterally closer to the perpendicular which passes through the origin 36 than is the end of the third segment 30c which is joined to the second segment 30b. As described above, a free space is defined between the three segments 30a , 30b and 30c. Also as described above, a longitudinal projection originating within the free space and oriented towards and generally perpendicular to the plane of the substrate 24 will intercept one of the lateral segments 30a, 30b or 30c which defines the free space, particularly the lateral segment 30a, 30b or 30c longitudinally closer towards the plane of the substrate 24.
It will be apparent to one skilled in the art that prongs 22 which do not have sharp discontinuities or other stress raisers are generally preferable. Thus, even the segmented arrangements illustrated in FIGS. 5 and 6 may be made more arcuate than is shown in these figures.
The openings or localized elastic deformations allow for entry of the engaging means 30 into the plane of the receiving surface, while the strands (or nondeformed material) of the receiving surface interposed between the openings (or deformed areas) prevents withdrawal or release of the fastening system 20 until desired by the user or either the peel or shear strength of the fastening system 20 is otherwise exceeded. The plane of the receiving surface may be flat or curved.
A receiving surface having strands or fibers, is said to be "complementary" if the openings between strands or fibers are sized to allow at least one engaging means 30 to penetrate into the plane of the receiving surface, and the strands are sized to be intercepted by the engaging means 30. A receiving surface which is locally deformable is said to be "complementary" if at least one engaging means 30 is able to cause a localized disturbance to the plane of the receiving surface, which disturbance resists removal or separation of the fastening system 20 from the receiving surface. Suitable receiving surfaces include reticulated foams, knitted fabrics, nonwoven materials, and stitchbonded loop materials, such as Velcro brand loop materials sold by Velcro USA of Manchester, N.H. A particularly suitable receiving surface is stitchbonded fabric Number 970026 sold by the Milliken Company of Spartanburg, S.C.
Referring back to FIG. 2, the free space defines the minimum lateral dimension 40 and minimum longitudinal dimension 42 of the engaging means 30. As used herein, the "minimum longitudinal dimension" is the shortest distance taken perpendicular to the plane of the substrate 24 through which a strand or fiber of the receiving surface must pass to enter the free space. If the engaging means 30 longitudinally projects toward the plane of the substrate 24, as shown in the figures, the minimum longitudinal dimension 42 is between the plane of the substrate 24 and the engaging means 30. Alternatively, if the engaging means 30 has a segment which longitudinally projects away from the plane of the substrate 24, the minimum longitudinal dimension 42 is between segments of the engaging means 30. For the embodiments and receiving surfaces described herein, prongs 22 with engaging means 30 having a minimum longitudinal dimension 42 of about 0.2 millimeters to about 0.08 millimeters (0.008 to 0.03 inches) is suitable.
Similarly, the "minimum lateral dimension" is the shortest distance, taken parallel to the plane of the substrate 24, through which a strand or fiber of the receiving surface must pass to enter the free space. The minimum lateral dimension 40 is formed between the engaging means 30 and shank 28, or between segments of the engaging means 30. For the embodiments and receiving surfaces described herein, prongs 22 with engaging means 30 having a minimum lateral dimension 40 of about 0.2 millimeters to about 0.8 millimeters (0.008 to 0.03 inches) is suitable. All of the prongs 22 illustrated in the figures have a greater minimum longitudinal dimension 42 than minimum lateral dimension 40.
PROCESS OF MANUFACTURE
The fastening system 20 according to the present invention may be manufactured using a modified gravure printing process. Gravure printing is well known in the art as illustrated by U.S. Pat. No. 4,643,130 issued Feb. 17, 1988, to Sheath et al. and incorporated herein by reference to illustrate the general state of the art. Referring to FIG. 7, the substrate 24 is passed through the nip 70 formed between two rolls, a print roll 72 and a backing roll 74. The rolls 72 and 74 have substantially mutually parallel centerlines disposed generally parallel to the plane of the substrate 24. The rolls 72 and 74 are rotated about the respective centerlines and have generally equal surface velocities, in both magnitude and direction, at the nip point 70. If desired, both the print roll 72 and the backing roll 74 may be driven by an external motive force (not shown), or one roll driven by external motive force and the second roll driven by frictional engagement with the first roll. An alternating current electric motor having an output of about 1,500 watts provides adequate driving force. By rotating, the rolls 72 and 74 actuate a depositing means for depositing the prongs 22 onto the substrate 24.
The depositing means should be able to accommodate the temperature of the material of prongs 22 in the liquid state, provide substantially uniform pitch between the prongs 22 in both the machine and cross-machine directions and yield the desired density of prongs 22 within the array. Also, the depositing means should be able to produce prongs 22 having various diameters of the base 26 and heights of the shank 23. The print roll 72, specifically, provides for the depositing means to deposit the prongs 22 on the substrate 24 in a desired pattern according to the present manufacturing process. The phrase "depositing means" refers to anything which transfers liquid prong material from a bulk quantity to the substrate 24 in dosages corresponding to individual prongs 22. The term "deposit" means to transfer prong material from the bulk form and dose such material onto the substrate 24 in units corresponding to individual prongs 22.
One suitable depositing means for depositing prong material onto the substrate 24 is an array of cells 76 in the print roll 72. As used herein the term "cell" refers to any cavity, or other component of the print roll 72, which transfers prong material from a source to the substrate 24 and deposits this material onto the substrate 24 in discrete units.
The cross sectional area of the cell 76, taken at the surface of the print roll 72, generally corresponds with the shape of the footprint of the base 26 of the prong 22. The cross section of the cell 76 should be approximately equal to the desired cross section of the base 26. The depth of the cell 76, in part, determines the longitudinal length of the prong 22, specifically the perpendicular distance from the base 26 to the point or segment of highest elevation. However, as the depth of the cell 76 increases to more than approximately 70 percent of the diameter of the cell 76, the longitudinal dimension of the prong 22 generally remains constant. This is because not all of the liquid prong material is pulled out of the cell 76 and deposited on the substrate 24. Due to the surface tension and viscosity of the liquid prong material, some of it will remain in the cell 76 and not be transferred to the substrate 24.
For the embodiment described herein, a blind, generally cylindrically shaped cell 76 having a depth between about 50 and about 70 percent of the diameter is adequate. If desired, the cell 76 may be somewhat frustroconically tapered in shape to accommodate conventional manufacturing processes, such as chemical etching.
If frustroconically shaped, the included angle of the taper of the cell 76 should be no more than about 45° to produce a preferred taper of the shank 28. If the taper of the cell 76 has a greater included angle, a prong 22 having too much taper may result. If the included angle of the taper is too small, or the cell 76 is cylindrical, a shank 28 of generally uniform cross section may result, and thereby have areas of higher stress. For the embodiment described herein a cell 76 having an angle of taper of about 45°, a diameter at the roll periphery of about 0.89 millimeters to about 1.22 millimeters (0.035 to 0.048 inches) and a depth ranging from about 0.25 millimeters to about 0.51 millimeters) 0.01 to 0.02 inches produces a suitable prong 22.
The print roll 72 and backing roll 74 should be compressed, coincident with the line connecting the centerlines of the rolls 72 and 74, to press the adhesive from the cells 76 in the print roll 72 onto the substrate 24 and to provide sufficient frictional engagement to drive the opposing roll if it is not externally motivated. The backing roll 74 is preferably somewhat softer and more compliant than the print roll 72 to provide cushioning of the prong material as it is deposited on the substrate 24 from the print roll 72. A backing roll 74 having a rubber coating with a Shore A durometer hardness of about 40 to about 60 is suitable. The rolls 72 and 74 may be pressed together with such a force that an impression in the machine direction of about 6.4 millimeters to about 12.7 millimeters (0.25 to 0.50 inches) is obtained. As used herein the term "impression" refers to the contact area of the softer roll on the substrate 24 as it passes through the nip 70.
The print roll 72 temperature is not critical, however, preferably, the print roll 72 is heated to prevent solidification of the prongs 22 during transfer from the source through the deposition on the substrate 24. Generally a print roll 72 surface temperature near the source material temperature is desired. A print roll 72 temperature of about 197° C. has been found to work well.
It is to be recognized that a chill roll may be necessary if the substrate 24 is adversely affected by the heat transferred from the prong material. If a chill roll is desired, it may be incorporated into the backing roll 74 using means well known to one skilled in the art. This arrangement is often necessary if a polypropylene or polyethylene substrate 24 is used.
The material used to form the individual prongs 22 must be kept in a source which provides for the proper temperature to apply the prongs 22 to the substrate 24. Typically, a temperature slightly above the melting point of the material is desired. The material is considered to be at or above the "melting point" if the material is wholly in the liquid state. If the source of the prong material is kept at too high a temperature, the prong material may not be viscous enough and may produce engaging means 30 which laterally connect to the prongs 22 adjacent in the machine direction. If the material temperature is very hot, the prong 22 will flow into a small, somewhat semispherically shaped puddle and an engaging means 30 will not be formed. Conversely, if the source temperature is too low, the prong material may not transfer from the source to the depositing means 76 or, subsequently, may not properly transfer from the depositing means 76 to the substrate 24 in the desired array or pattern. The source of the material should also impart a generally uniform cross-machine direction temperature profile to the material, be in communication with the depositing means 76 and easily be replenished or restocked as the prong material becomes depleted.
A suitable source is a trough 80, substantially coextensive of that portion of the cross-machine dimension of the print roll 72 which has cells 76 and adjacent thereto. The trough 80 has a closed end bottom, an outboard side and ends. The top may be open or closed as desired. The inboard side of the trough 80 is open, allowing the liquid material therein to freely contact and communicate with the circumference of the print roll 72.
The source is externally heated by known means (not shown) to maintain the prong material in a liquid state and at the proper temperature. The preferred temperature is above the melting point but below that at which a significant loss of viscoelasticity occurs. If desired, the liquid material inside the trough 80 may be mixed or recirculated to promote homogeneity and an even temperature distribution.
Juxtaposed with the bottom of the trough 80 is a doctor blade 82 which controls the amount of prong material applied to the print roll 72. The doctor blade 82 and trough 80 are held stationary as the print roll 72 is rotated, allowing the doctor blade 82 to wipe the circumference of the roll 72 and scrape any prong material which is not disposed within the individual cells 76 from the roll 72 and allows such material to be recycled. This arrangement allows prong material to be deposited from the cells 76 to the substrate 24 in the desired array, according to the geometry of the cells 76 on the circumference of the print roll 72. As seen in FIG. 7, the doctor blade 82 is preferentially disposed in the horizontal plane, particularly the horizontal apex of the print roll 72, which horizontal apex is immediately upstream of the nip 70.
After being deposited onto the substrate 24, the prongs 22 are severed from the print roll 72 and the depositing means 76 by a severing means for severing 78 the prongs 22 into the engaging means 30 of the fastening system 20 and a moil. As used herein the term "moil" refers to any material severed from the prong 22 and which does not form part of the fastening system 20.
The severing means 78 should be adjustable to accommodate various sizes of prongs 22 and lateral projections 38 of engaging means 30 and also provide uniformity throughout the cross-machine direction of the array. The term "severing means" refers to anything which longitudinally separates the moil from the fastening system 20. The term "sever" refers to the act of dividing the moil from the fastening system 20 as described above. The severing means 78 should also be clean and should not rust, oxidize or impart corrodents and contaminates (such as moil material) to the prongs 22. A suitable severing means is a wire 78 disposed generally parallel to the axis of the rolls 72 and 74 and spaced from the substrate 24 a distance which is somewhat greater than the perpendicular distance from the highest elevation of the solidified prong 22 to the substrate 24.
Preferably the wire 78 is electrically heated to prevent build-up of the molten prong material on the severing means 78, accommodate any cooling of the prongs 22 which occurs between the time the prong material leaves the heated source and severing occurs and promote lateral stretching of the engaging means 30. The heating of the severing means 78 should also provide for uniform temperature distribution in the cross-machine direction, so that an array of prongs 22 having substantially uniform geometry is produced.
Generally, as the prong material temperature increases, a relatively cooler hot wire 78 temperature severing means can be accommodated. Also, as the speed of the substrate 24 is decreased, less frequent cooling of the hot wire 78 occurs as each prong 22 and moil are severed, making a relatively lower wattage hot wire 78 more feasible at the same temperatures. It should be recognized that as the temperature of the hot wire 78 is increased a prong 22 having a generally shorter shank 28 length will result. Conversely, the shank 28 length and lateral length of the engaging means 30 will be increased in inverse proportion as the temperature of the hot wire 78 is decreased. It is not necessary that the severing means 78 actually contact the prong 22 for severing to occur. The prong 22 may be severed by the radiant heat emitted from the severing means 78.
For the embodiment described herein, a round cross section nickel-chromium wire 78, having a diameter of about 0.51 millimeters (0.02 inches) heated to a temperature of about 343° C. to about 416° C. has been found suitable. It will be apparent that a knife, laser cutting or other severing means 78 may be substituted for the hot wire 78 described above.
It is important that the severing means 78 be disposed at a position which allows stretching of the prong material to occur prior to the prong 22 being severed from the moil. If the severing means 78 is disposed too far from the plane of the substrate 24, the prong material will pass underneath the severing means 78 and not be intercepted by it, forming a very long engaging means 30 which will not be properly spaced from the substrate 24 or adjacent prongs 22. Conversely, if the severing means 78 is disposed too close to the plane of the substrate 24, the severing means 78 will truncate the shank 28 and an engaging means 30 may not be formed.
A hot wire severing means 78 disposed approximately 14 millimeters to 22 millimeters (0.56 to 0.88 inches), preferably about 18 millimeters (0.72 inches) in the machine direction from the nip point 70, approximately 4.8 millimeters to 7.9 millimeters (0.19 to 0.31 inches), preferably about 6.4 millimeters (0.25 inches) radially outward from the backing roll 74 and approximately 1.5 millimeters to approximately 4.8 millimeters (0.06 to 0.19 inches), preferably about 3.3 millimeters (0.13 inches) radially outwardly from the print roll 72 is adequately positioned for the process of manufacture disclosed herein.
In operation, the substrate 24 is transported in a first direction relative to the depositing means 76. More particularly, the substrate 24 is transported through the nip 70, preferentially drawn by a take-up roll (not shown). This provides a clean area of substrate 24 for continuous deposition of prongs 22 and removes the portions of the substrate 24 having prongs 22 deposited thereon. The direction generally parallel to the principal direction of transport of the substrate 24 as it passes through the nip 70 is referred to as the "machine direction." The machine direction, as indicated by the arrows 75 of FIG. 7, is generally orthogonal the centerline of the print roll 72 and backing roll 74. The direction generally orthogonal to the machine direction and parallel to the plane of the substrate 24 is referred to as the "cross-machine direction."
The substrate 24 may be drawn through the nip 70 at a speed approximately 2% to approximately 10% greater than the surface speed of the rolls 72 and 74. This is done to minimize bunching or puckering of the substrate 24 near the means for severing 78 the prongs 22 from the means for depositing the prong material on the substrate 24. The substrate 24 is transported through the nip 70 in the first direction at about 3 to about 31 meters per minute (10 to 100 feet per minute).
If desired, the substrate 24 may be inclined at an angle γ, approximately 35° to approximately 55°, preferably about 45°, from the plane of the nip 70 towards the backing roll 74 to utilize the viscoelastic nature of the prong material and properly orient the engaging means 30 in the lateral direction, as well as longitudinal direction. This arrangement also provides a greater force to extract the prong material from the cell 76 and to pull the prong 22 away from the print roll 72. Also, increasing the angle γ of deviation from the plane of the nip 70 has a weak, but positive effect to produce engaging means 30 having a greater lateral projection 38.
After depositing prong material from the cell 76 onto the substrate 24, the rolls 72 and 74 continue rotation, in the directions indicated by the arrows 75 of FIG. 7. This results in a period of relative displacement between the transported substrate 24 and the cells 76 during which period (prior to severing) the prong material bridges the substrate 24 and print roll 72. As relative displacement continues, the prong material is stretched until severing occurs and the prong 22 is separated from the cell 76 of the print roll 72. As used herein the term "stretch" means to increase in linear dimension, at least a portion of which increase becomes substantially permanent for the life of the fastening system 20.
As discussed above, it is also necessary to sever the individual prongs 22 from the print roll 72 as part of the process which forms the engaging means 30. When severed, a prong 22 is longitudinally divided into two parts, a distal end and engaging means 30 which remain with the fastening system 20 and a moil (not shown) which remains with the print roll 72 and may be recycled, as desired. After the prongs 22 are severed from the moil, the fastening system 20 is allowed to freeze prior to contact of the prongs 22 with other objects. After solidification of the prongs 22, the substrate 24 may be wound into a roll for storage as desired.
Several parameters of the manufacturing process affect the included angle θ of the engaging means. For example, as the distance between the hot wire 78 and the substrate 24 is increased, the included angle θ of the engaging means generally becomes relatively greater. This occurs because as the length of the engaging means, particularly the lateral projection 38, becomes greater, a larger included angle θ can be accommodated. Also, as the angle γ between the substrate and the plane of the nip is increased an engaging means 30 having a relatively greater angle θ is formed. This occurs because of the relatively greater lateral stretching of the prong material prior to solidification. Also, the influence of gravity has a greater lateral component as the angle γ increases.
Conversely, as the temperature of the prong material when deposited increases, an engaging means 30 having a relatively lesser included angle θ will be formed. This occurs because the hotter material will more easily flow under the influence of gravity towards the substrate, yielding an included angle θ more nearly about 180°. However, if the rate of cooling of the engaging means is increased when the prong material is deposited on the substrate 24, a relatively greater included angle θ can be formed. A parameter related to the cooling rate is the rate of transport of the substrate 24. As the substrate is transported at a greater speed, a relatively smaller included angle θ results. This occurs because there is less time for the prong material to cool prior to being intercepted by the severing means 78.
A nonlimiting illustration of the process which produces a prong 22 having an engaging means 30 within include angle θ of about 270°±40° shows the prong material to be disposed in the trough 80 and heated by means commonly known to one skilled in the art, to a temperature somewhat above the melting point. If a polyester resin hot melt adhesive is selected, a material temperature of approximately 177°-193° C., preferably about 186° C. has been found suitable. If a polyamide resin is selected, a material temperature of approximately 193°-213° C., preferably about 200° C. has been found suitable. A one side bleached kraft paper substrate 24 about 0.008 to about 0.15 millimeters (0.003 to 0.006 inches) in thickness works well with hot melt adhesive prongs 22. The prongs 22 are joined to the bleached side of the kraft paper substrate 24.
For the illustrated operation described herein, print roll 72 having an array of about 5 cells 76 per centimeter (13 cells 76 per inch) in both the machine direction and cross-machine directions, yielding a grid of about 26 cells 76 per square centimeter (169 cells 76 per square inch), is suitable. This grid density may be advantageously used with a print roll 72 having a diameter of about 16 centimeters (6.3 inches), with cells 76 about 1.1 millimeters (0.045 inches) in diameter and about 0.76 millimeters (0.030 inches) deep. A backing roll 74 having a diameter of about 15.2 centimeters (6.0 inches) and vertically registered has been found to work well with the aforementioned print roll 72. The rate of transport of the substrate 24 is about 3.0 meters per minute (10 feet per minute).
A nickel-chromium hot wire 78 having a diameter of about 0.51 millimeters (0.02 inches) disposed approximately 18.2 millimeters (0.72 inches) from the nip point 70 in the machine direction, approximately 0.33 millimeters (0.13 inches) radially outwardly from the print roll 72 and approximately 6.35 millimeters (0.25 inches) radially outwardly from the backing roll 74 is heated to a temperature of about 382° C. The fastening system 20 produced by this operation is substantially similar to that illustrated by FIG. 1 which fastening system 20 may be advantageously incorporated into the illustrative article of use discussed below.
Without being bound by any particular theory, it is believed that the geometry of the engaging means 30 is governed by the differential cooling of the prong 22. The trailing edge 46 of the prong 22 is shielded and insulated from the heat originating from the severing means 78. Conversely, the leading edge 42 is directly exposed to the heat of the severing means 78, which causes the leading edge 42 to cool more slowly than the rate at which the trailing edge 46 cools. The resulting differential cooling rate causes elongation of the leading edge 42 and contraction of the trailing edge 46, relative to each other. As this differential cooling rate is increased, a relatively longer engaging means 30 is formed, typically yielding a relatively greater included angle θ.
Without being bound by further theory, it is believed that the arcuate shape and curl of the engaging means 30 occur due to differences in stresses which occur upon freezing of the material of the prong 22. It is believed that the material above the neutral axis of the prong is somewhat tensioned while the material below the neutral axis is in compression. This differential stress field pulls and pushes against the material on opposite sides of the neutral axis, changing the lateral orientation and geometry of the engaging means 30 during the freezing of the prong material.
If desired, a fastening system 20 having relatively very small prongs 22 (not shown) may be made by forming a natural pattern from the print roll 72. As used herein, the term "natural pattern" refers to array of prongs 22 resulting from a print roll 72 which does not have cells 76 disposed thereon, but instead which utilizes the surface of the roll 72 as the depositing means 76. Thus, the pattern of prongs 22 is formed by the clearance between the doctor blade 82 and the print roll 72, and to a lesser extent by the surface finish of the print roll 72.
The doctor blade 82 should be adjusted to provide about a gap of about 0.03 millimeters to about 0.08 millimeters (0.001 to 0.003 inches) in radial clearance from the print roll 72. To form a natural pattern, the very small sized prongs 22 resulting from such a print roll 72 are advantageously utilized with a reticulated foam receiving surface that does not have strands and openings therebetween, but rather incurs localized elastic deformations which resist separation of the fastening system 20.
Alternatively, the fastening system 20 of the present invention may be produced by molding techniques generally well known in the art. For example, a fastening system system according to the present invention may be constructed by the method disclosed in U.S. Pat. No. 4,056,593 issued on Nov. 1, 1977 to de Navas Albareda and incorporated herein by reference to illustrate an alternative process of manufacture, teaches producing a fastening system 20 by extruding a strip of material from a die having a cross section corresponding to the desired shape of the fastening system. The strip of extruded material is then transversely cut to form notches defining individual and substantially similarly shaped prong elements.
U.S. Pat. No. 4,462,784 issued on July 31, 1984 to Russell, incorporated herein by reference to illustrate a second alternative process of manufacture which may be used to construct a fastening system 20 according to the present invention, teaches continuous molding of objects using a rotatable wheel with peripheral orifices, referred to as cavities. The cavities are complementary in shape to the desired finished product. Plastic is extruded through an orifice, filling the cavity and solidifying therein. After molding, selected portions of the objects to be formed are selectively stretched.
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An improved releasably securable fastening system for attaching to a complementary receiving surface is disclosed. The fastening system features an engaging means in the form of a hook-shaped tine. The engaging means is longitudinally spaced away from, or above, a substrate by an upstanding shank. The engaging means forms an included angle, relative to the perpendicular from the plane of the substrate, which is greater than 180° so that the engaging means has a reentrant segment. The reentrant segment of the engaging means provides for more effective securing of the fastening system to a receiving surface. An engaging means having an included angle greater than 180° provides improved resistance to forces which cause separation of the engaging means from the receiving surface.
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CROSS REFERENCE TO A RELATED APPLICATION
This application is a continuation in part of application Ser. No. 540,505, filed Jan. 13, 1975 and now Pat. No. 3,935,858.
SUMMARY OF THE INVENTION
This invention relates to an orthopedic device for immobilizing a body part of a patient and will have specific but not limited application to a knee, ankle or wrist immobilizer which is of universal application to accommodate patients of varying size.
The immobilizer includes a flexible cover which extends around the body part of the patient. A pair of stays are detachably connected to the cover and positioned one on one side and one on the other side of the body part. The stays may also carry belts or similar securement means by which the cover of the immobilizer is secured about the body part. The position of the pair of stays by being detachably connected to the immobilizer cover can be varied so as to accommodate the particular size of the patient. Accordingly, it is an object of this invention to provide a body part immobilizer which is of universal application to accommodate patients of different size.
Another object of this invention is to provide a wraparound immobilizer for the knee, ankle, wrist or other body part in which stays are adjustably applied to the cover of the immobilizer.
Still another object of this invention is to provide an immobilizer which is for a body part of a patient and which includes detachable stays positioned on the sides of the body part and carrying means for securing the cover about the body part.
Other objects of this invention will become apparent upon a reading of the invention's description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a knee immobilizer shown in detached form.
FIG. 1A is a detailed view of that portion of FIG. 1 within broken line circle 1A.
FIG. 2 is a plan view of the knee immobilizer showing the stays thereof detached from the immobilizer.
FIG. 3 is a perspective view of the knee immobilizer shown applied about the knee of a patient and as viewed from one side.
FIG. 4 is also a perspective view of the immobilizer shown applied about the knee of the patient and viewed from the opposite side.
FIG. 5 is a fragmentary cross sectional view taken along line 5--5 of FIG. 1.
FIG. 6 is a plan view of a wrist immobilizer.
FIG. 7 is a plan view of the wrist immobilizer showing a stay thereof detached from the immobilizer.
FIG. 8 is a perspective view of the wrist immobilizer shown applied about the wrist of a patient.
FIG. 9 is a plan view of an ankle immobilizer shown with the fore stay pad detached.
FIG. 10 is a perspective view of the ankle immobilizer showing the stays and fore stay pad detached from the immobilizer.
FIG. 11 is a perspective view of the ankle immobilizer shown applied about the ankle of a patient.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments illustrated are not intended to be exhaustive or to limit the invention to the precise forms disclosed. They are chosen and described in order to best explain the principles of the invention and its application and practical use to thereby enable others skilled in the art to best utilize the invention.
The immobilizer shown in FIGS. 1-5 includes a flexible cover 10. Cover 10 includes an upper edge 12 and a parallel lower edge 14, as well as side edges 16 and 18. To accommodate the anatomical shape of a patient's leg 20, side edges 16 and 18 preferably taper from upper edge 12 to lower edge 14 with the cover assuming a trapezoidal appearance when in planar form. Also each side edge 16 and 18 may be formed with a cut-out 22 to accommodate the knee cap of the patient. Cover 10 may be formed of any one of a variety of materials, such as a polyvinyl foam construction, having a looped pile material 24 applied to its outer surface. A fixed stay 26 is positioned midway between side edges 16 and 18 and extends from upper edge 12 to lower edge 14 of the cover. Stay 26 is secured in position by being sewn or otherwise appropriately affixed to cover 10. Stay 26 is shaped to generally conform to the anatomical curvature of the back of the leg at the knee.
Also connected to cover 10 are a pair of detachable stays 30 and 32. Stays 30 and 32 are located to the inside and outside of the knee when the immobilizer is secured about the patient as shown in FIGS. 3 and 4. Each stay 30 and 32 includes an encasement 34 to which a plurality of hook or similar type securement members 36 are attached to one side. Hook members 36 are designed so as to engage and interlock with the loop pile material 24 of cover 10 and serve to connect stays 30 and 32 to the cover. Hook members 36 of stays 30 and 32 and loop pile material 24 of cover 10 may be of the cooperating interlocking type sold under the well known trademark "Velcro". Stays 30 and 32 are connected to cover 10 by having their hook members 36 pressed into engagement with loop pile material 24 of the cover. Rings 38 and straps 40 are also secured to stays 30 and 32 for the purpose of securing cover 10 about the knee of the patient.
In FIGS. 3 and 4 the immobilizer is shown attached to leg 20. Cover 10 is wrapped around the knee with stay 26 being positioned to the rear or back of the knee and with side edges 16 and 18 in a juxtaposed or overlapping arrangement, depending upon the size of the patient. Stays 30 and 32 are applied to the cover at selected locations on the inside and outside of the knee, thus providing lateral rigidity to the immobilizer. The free end portions of straps 40 are inserted through rings 38 and return bent so that the hook members 42 of each strap can be pressed into interlocking engagement with the pile material 44 extending along the remainder of the strap.
By utilizing loop pile material with cover 10 and hook member attachments with stays 30 and 32, the stays can be easily removed from and reapplied to the cover in adjusting the immobilizer to accommodate a particular size patient. The interlocking adherence between hook members 36 of stays 30 and 32 and the loop pile material of cover 10 is of sufficient strength to enable the cover to be secured about the patient's knee through the use of rings 38 and straps 40.
While it is preferred that stays 30 and 32 of the immobilizer also carry the means for securing cover 10 about the knee of the patient, it is to be understood that such securement means whether straps, rings or buckles can be sewn directly to cover 10 with detachable stays 30 and 32 serving only as rigidifying means.
The immobilizer shown in FIGS. 6-8 includes a flexible cover 50 having looped pile material 52 applied to its outer surface. A pair of stays 54 and 56 are connected to cover 50. Stay 56 is detachable and includes an encasement 58 to which a plurality of hooks 59 are attached to one side. Stay 54 is preferably sewn to cover 50 but if desired can be of a similar detachable construction as stay 56. Stay 56 carries straps 60 and stay 54 carries rings 62 for securing the immobilizer about the wrist of the patient as shown in FIG. 8 with the straps being inserted through the rings and return bent to have hook 64 carried by the straps pressed into locking engagement with pile material 66 extending along the straps.
Strap 68 of hook material serves to secure tab 70 about the hand of the patient. The hooks 59 of stay 56 allow the stay to be pressed into interlocking engagement with cover material 52 and selectively located to accommodate the wrist of the patient.
The immobilizer shown in FIGS. 9-11 includes a cover 80 having looped pile material 82 applied to its outer surface. Cover 80 has a center opening 84 to accommodate the heel 85 of the patient. A pair of detachable stays 86 and 87 are connected to cover 80 and located at the inside and outside of the foot when the immobilizer is applied to the patient's ankle. Stays 86 and 87 are bent to a desired anatomical configuration and each includes an encasement 88 to which a plurality of hooks 90 are attached to one side. Each stay carries one or more straps 92 and one or more rings 94 for securing the immobilizer about the ankle of the patient as shown in FIG. 11. A fore stay pad 96 is applied over the front of the ankle with side edges 98 of cover 80 preferably overlapping the pad and straps 92 passing through loops 100 of the pad.
Straps 92 are also inserted through rings 94 and return bent with the hooks 90 carried by the straps being pressed into interlocking engagement with material 82 of the cover and similar material forming the outer side of stay encasements 88.
In the wrist and ankle immobilizer embodiments of FIGS. 6-11, pile material 52 and 82 and hooks 59 and 90 may be of the cooperating interlocking type sold under the trademark "Velcro." It is to be understood that the invention may be applied to various types of body part immobilizers and is not to be limited to the details above given but may be modified within the scope of the appended claims.
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A wraparound immobilizer for a body part of a patient, such as the knee, ankle or wrist, in which the inside and outside stays which assist in immobilizing the body part are adjustable to accommodate the size of the patient. Additionally, the stays may carry the attachment straps by which the immobilizer is secured about the body part.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to an apparatus for and a method of generating a straight line in a discrete coordinate system, and more specifically to generation of a straight line of pixels by utilizing, for example, the Bresenham algorithm.
2. Prior Art
As a method of generating a straight line of pixels, such a method as DDA (Digital Differential Analysis) system has been known. Japanese Patent Public Disclosure No. 94378/85 discloses an example wherein the DDA system has been realized. FIG. 1 is a block diagram illustrating the construction of a straight line generator which employs the conventional DDA system. The reference numeral 51 designates an X-counter which increases or decreases an X coordinate; 52 a Y-counter which increases or decreases a Y coordinate; 53 a slope register adapted to hold the gradient of a slope; 54 an adder adapted to accumulate the content of the slope register; 55 a register adapted to hold the content of the adder 54; and 56, 57 selectors adapted to select carry signal from the adder 54 and a clock signal. The slope register 53, the adder 54 and the register 55 constitute a decimal-fraction calculating circuit adapted to compute a decimal fraction.
The operation of the DDA system will now be explained by referring to FIG. 1. Using the coordinate (XS, YS) of the start point and the coordinate (XE, YE) of the end point of a straight line the absolute value |X|=|XE-XS| of a difference value X of the X coordinate components and the absolute value |Y|=|YE-YS| of a difference value Y of the Y coordinate components between those two points are calculated by a circuit provided outside the straight line generator. (It is to be understood that the coordinate axis which corresponds to a large one of the absolute values |X| and |Y| will be referred to as the main axis.) It is assumed here that the X axis is the main axis. The slope of the line can be obtained by calculating the ratio between such two absolute values. In this case, it is also assumed that a larger absolute value of the respective coordinate components is used as a denominator and a smaller absolute value of the respective coordinate components is used as a numerator so as to calculate the ratio. Since the denominator is larger than the numerator, the ratio obtained is a decimal fraction less than unity. In this way, the ratio is equal to |Y|/|X|. First, after the register 55 has been reset, the ratio is loaded in the slope register 53, the X coordinate of the start point in the X-counter 51 and the Y coordinate of the start point in the Y-counter 52, respectively. The selectors 56, 57 operate to supply the clock signal to the counter for the main coordinate axis and the carry signal generated by the adder 54 at the time of adding the ratio output from the slope register 53 for every clock, to the counter for the rest of the coordinate axes. This causes the counter corresponding to the main coordinate axis to be operated for each clock and the counter for the rest of the coordinate axes to be operated by the carry signal output from the adder 54, whereby the X-counter 51 and the Y-counter 52 calculate interpolated coordinate values from the start point to the end point of the line and output such values. By repeating this operation, pixels making a straight line may be generated.
Besides the method explained above, many other methods of line drawing have been employed. Among them, a method of which the algorithm is simple and which is suitable for implementation in hardware is the Bresenham method which is very widely utilized today. A hardware version of a line drawing process using the Bresenham algorithm is found in Japanese Patent Public Disclosure No. 165280/87 filed by IBM Corp. with the title of "Set-up Apparatus for Graphic Vector Generator".
In the Bresenham algorithm, although it is not described in detail here, either one of the coordinate values is varied by ±1. The other of the coordinates may be varied or not depending on the value of an error term. The error term means a recorded distance between a correct path on a line measured to the direction perpendicular to the maximum variation axis (the main axis) and a point actually generated. In the case of |X|≧|Y|, since the X axis is the maximum variation axis (or the main axis), the error term e is accordingly measured in the Y axis direction. It is to be noted here that the error term e is utilized to make a decision of being positive or negative and may be added by an integer for use.
Since a straight line generator according to the prior art is constituted as shown in FIG. 1, division has to be performed to compute the slope of the line and generation of parameters for such division takes time, resulting in a reduction in processing performance. In addition, the rate of time generation is also reduced due to the fact that data used for calculation are decimal fractions and therefore long.
Furthermore, since the "Set-up Apparatus for Graphic Vector Generator" disclosed in the above Japanese Patent Public Disclosure Official Gazette is an apparatus in which the symmetry of graphics is taken into consideration, parameters relating to X coordinate values have, in some conditions, to be exchanged with parameters relating to Y coordinate values. This necessitates a "swapping circuit", resulting in a large hardware scale and a long parameter setting-up time.
SUMMARY OF THE INVENTION
The present invention has been proposed to eliminate such problems as above described and has as its object to provide an apparatus for and a method of generating a straight line of pixels at a high speed in the range of 360 degrees without exchanging parameters.
A straight line generator according to an aspect of the present invention intends to improve the Bresenham algorithm and comprises a first counter which holds an X coordinate value and is capable of incrementing and decrementing the X coordinate value, a second counter which holds a Y coordinate value and is capable of incrementing and decrementing the Y coordinate value, a region code register for holding the region code depending on the slope of a line within the range of 360 degrees, an error register for holding an error term in the Bresenham algorithm, control logic for controlling an up/down counting operation of the first and second counters, N- and P-registers for holding data which cause the error register to be varied, and an adder for selecting either of the data in the N-register and the P-register by referring to the sign indicated by the error register so as to add the selected data to the error register.
Another aspect of the present invention assumes an apparatus for generating linear pixels comprising:
(a) means for reading X coordinate values and Y coordinate values of the start point and the end point of a line;
(b) means for computing an X difference absolute value and a Y difference absolute value between the start point and the end point of line;
(c) means for computing a region code defining one of the regions obtained by dividing the range of 360 degrees in accordance with the X difference value, the Y difference value and the ratio of these difference absolute values;
(d) means for computing an initial error term value based on the ratio of the X difference absolute value and the Y difference absolute value;
(e) means for computing a positive added value which is added to the error term when the error term value is positive;
(f) means for computing a negative added value which is added to the error term when the error term value is negative;
(g) means for executing the increment and decrement operations of the X and Y coordinates specified by a combination of the region code and the error term; and
(h) means for adding either of the positive added value and the negative added value to the error term on the bases of a value of the error term, the pixel generating means and the error term adding means being repeatedly operated.
A further aspect of the present invention assumes a method of generating a straight line of pixels, comprising the steps of:
(a) reading X coordinate values and Y coordinate values of the start point and the end point of a line;
(b) computing an X difference absolute value and a Y difference absolute value between the start point and the end point of the linear line;
(c) computing a region code defining one of the regions obtained by dividing a circle in accordance with the X difference value, the Y difference value and the ratio of these difference absolute values;
(d) computing an initial error term value based on the ratio of the X difference absolute value and the Y difference absolute value;
(e) computing a positive added value which is added to the error term when the error term value is positive;
(f) computing a negative added value which is added to the error term when the error term value is negative;
(g) executing increment and decrement operations of the X and Y coordinates specified by a combination of the region code and the error term;
(h) adding either of the positive added value and the negative added value to the error term on the basis of a sign of the error term; and
(i) repeating the pixel generating step and the error term adding step.
The straight line generator according to the present invention control up/down counting operations of the first counter and the second counter under the controls of the control logic based on the region code provided by the region code register and the sign of the error register (or the sign of the error term) so as to generate a straight line pixels by outputting X and Y addresses.
At the same time, the data of either of the N-register or the P-register are added to the data (the error term) of the error register depending on the sign of the error term. Since such processing as described above are executed using integers, high-speed straight line generation may be achieved.
Furthermore, since the region codes can cover the range of 360 degrees, pixels may be directly generated without exchanging the starting point and the ending point as well as an X coordinate and a Y coordinate.
Further, in the apparatus for generating a straight line pixels according to the present invention, the region code computing means is capable of computing any one of the region codes for any slope of a line within 360 degrees.
Also, since the pixel generating means performs operations of incrementing and decrementing 16 kinds of X and Y coordinates provided by combinations of the region codes and the sign of the error terms, pixels may be generated for a line with any slope without exchanging the parameters.
Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the constitution of a straight line generator according to the prior art;
FIG. 2 is a conceptual diagram of a circuit for setting up line drawing parameters used for an embodiment of the present invention;
FIG. 3 is a flow chart illustrating parameter calculation steps;
FIG. 4 is a detailed diagram of the circuit for setting up parameters shown in FIG. 2;
FIG. 5 illustrates a relationship between the slope of a line and a region code thereof;
FIG. 6 illustrates conditions of the region codes;
FIG. 7 is a block diagram showing the constitution of an embodiment of a line generator according to the present invention;
FIG. 8 illustrates relationships among the slope of a line, X coordinates, Y coordinates, region codes, error data, P-register values and N-register values; and
FIG. 9 illustrates an example of a line drawn by the line generator shown in FIG. 7.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 2 is a schematic diagram of a circuit for setting up line drawing parameters which are used in an embodiment of the present invention (described later in detail).
In FIG. 2, the reference numeral 100 designates an X difference absolute value circuit for obtaining a difference between the X coordinate values of the opposite end points of a line and the absolute value of the difference; 110 a Y difference absolute value circuit for obtaining a difference between the Y coordinate values of the opposite end points of the line and the absolute value of the difference, 120 a region code calculating circuit adapted to obtain a region code A of a line in accordance with signals output from the X difference absolute value circuit 100 and the Y difference absolute value circuit 110; 130 an initial value calculating circuit for obtaining an initial value of an error (or referred to as an error term) in the Bresenham algorithm in accordance with a signal output from the region code calculating circuit 120; 140 a positive added value calculating circuit for obtaining a value P to be added to the error in the Bresenham algorithm based on a signal output from the region code calculating circuit 120 when the error is positive; 150 a negative added value calculating circuit for obtaining a value N to be added to the error in the Bresenham algorithm based on a signal output from the region code calculating circuit 120 when the error is negative; and 160 a line drawing point number calculating circuit for obtaining a signal T indicating the length of a line in the Bresenham algorithm based on a signal output from the region code calculating circuit 120.
FIG. 3 is a flow chart for explaining a process of computing parameters corresponding to FIG. 2.
In FIG. 3, the reference symbol STEP 1 designates an inputting step for reading X and Y coordinate values; STEP 2 a step for computing the absolute value of an X difference value; STEP 3 a step for computing the absolute value of a Y difference value; STEP 4 a step for computing a region code; STEP 5 a step for computing an initial value; STEP 6 a step for computing a positive added value; STEP 7 a step for computing a negative added value; and STEP 8 a step for computing the number of points to draw a line.
An operation of the straight line generator will now be described with reference to FIG. 4. Firstly, the X difference absolute value circuit 100 shown in FIG. 2 is explained. The reference numeral 210 designates a circuit for obtaining a difference between two inputs, that is, a difference between the X coordinate XS of the start point of a line and the X coordinate XE of the end point of the line; and 212 a circuit for obtaining the absolute value of an input signal, that is, to the circuit 212 (XE-XS) output from the circuit 210 is input and from the circuit 212 the absolute value |X|=|XE-XS| is output. More specifically, the computation of |X|=|XE-XS| in STEP 2 in FIG. 3 is executed here and the absolute value |X| of the difference between the X coordinates of the opposite end points constituting a line may be acquired. The circuit 210 outputs a code b0 of one bit. This one bit code b0 is 0 if XE≧XS and 1 if XE<XS. An operation of the Y difference absolute value circuit 110 in FIG. 2 is similar to that of the X difference absolute value circuit 100. Computation of |Y|=|YE-YS| in STEP 3 in FIG. 3 is executed by substituting YS for XS and YE for XE, whereby the absolute value |Y| of the difference between the Y coordinates of the opposite end points constituting the line may be obtained. The code output from the Y difference absolute value circuit 110 is designated as b1.
An operation of the region code calculating circuit 120 shown in FIG. 2 will next be explained. It is noted that a line to be drawn is classified to one of line patterns belonging to eight regions as shown in FIG. 5 by putting the starting point in the center. The conditions of the regions to which the respective line patterns belong are enumerated in FIG. 6. FIG. 5 shows codes of three bits given to the regions to which the respective line patterns belong and these codes of three bits are output from the region code calculating circuit 120. As it is seen from FIG. 6, two lower order bits in these three-bit codes correspond to the outputs b1 and b0 of the Y difference absolute value circuit 110 and the X difference absolute value circuit 100, respectively. The remaining one bit or b2 is obtained by comparing the outputs |X| of the X difference absolute value circuit 100 and |Y| of the Y difference absolute value circuit 110. If |X|≧|Y|, then b2=0. Conversely, if |X|<|Y|, then b2=1.
In this manner, the calculation specified in STEP 4 in FIG. 3 is executed and three-bit region code is output from the region code calculating circuit 120.
Operations of the initial value calculating circuit 130, the positive added value calculating circuit 140 and the negative added value calculating circuit 150 will next be explained. These circuits are operable depending on the output of the region code calculating circuit 120 or b2. As seen from FIG. 5 if b2 is 0, then a line is drawn along the X axis, the initial value in the Bresenham algorithm is equal to 2|Y|-|X|, the positive added value is equal to 2|Y|-2|X|, and the negative added value is equal to 2|Y|. Conversely, if b2 is 1, a line is drawn along the Y axis, the initial value in the Bresenham algorithm is equal to 2|X|-|Y|, the positive added value is equal to 2|X|-2|Y|, and the negative added value is equal to 2|X|. In FIG. 4, the reference numerals 214 and 215 designate inverters adapted to obtain the inverse of the input values; 216 through 219 shifters to make input values double; 220 through 223 adders adapted to obtain the sums of two input values; and 224 through 226 selectors adapted to select upper input values if b2 is 1 and select lower input values if b2 is 0. The output |X| of the X difference absolute value circuit 100 is converted to -|X| by the inverter 214, or 2|X| by the shifter 216. The output of the inverter 214 or -|X| is converted to -2|X| by the shifter 218. Similarly, 2|Y|, -|Y| and -2|Y| are obtained from the output |Y| of the Y difference absolute value circuit 110. Inputting these obtained values to the adders 220 through 223 result in 2|X|-|Y|, 2|X|-2|Y|, 2|Y|-|X| and 2|Y|-2|X|. 2|X| and 2|Y| also output from the shifters 216 and 217 are supplied to the selector 226 for selection, which enables computation in STEP 5 through STEP 7 to be executed to obtain the initial value, the positive added value and the negative added value.
An operation of the drawing point number calculating circuit 160 shown in FIG. 2 will next be explained. Similar to the initial value calculating circuit 130, the positive added value calculating circuit 140 and the negative added value calculating circuit 150, the circuit 160 is also operable depending on the output, b2, from the region code calculating circuit 120. More specifically, as explained above, if b2 is 0, a line is drawn along the X axis, so that the number of points to draw the line is equal to |X|+1. Conversely, if b2 is 1, since a line is drawn along the Y axis, the number of points to draw the line is equal to |Y|+1. In FIG. 4, the reference numeral 227 designates a selector; and 228 an adder. The selector 227 select |X| if b2 is 0 and |Y| if b2 is 1, and 1 is added by the adder 228 to the output of the selector 227, whereby the computation specified by STEP 8 in FIG. 3 is executed and the number of points to draw a line is computed.
In this manner, the initial value S, the positive added value P, the negative added value N and the number of points to draw a line T in the Bresenham algorithm have been obtained corresponding to the region codes as a preprocess for a straight line generator.
FIG. 7 is a block diagram illustrating the constitution of an embodiment of a straight line generator according to the present invention. In this figure, the reference numeral 11 designates an up/down X-counter which holds an X coordinate value; 12 designates an up/down Y-counter which holds a Y coordinate value; 13 a region code register which holds the region code depending on the slope of a linear line; 14 an error register which holds an error in the Bresenham algorithm; 15 a control logic adapted to control the increment and decrement of the X-counter 11 and the Y-counter 12 by referring to the data contained in the region code register 13 and the error register 14; 16 an N-register adapted to hold a parameter N (a negative added value) to be added when the data of the error register 14 is negative; 17 a P-register adapted to hold a parameter P (a positive added value) to be added when the data of the error register 14 is positive; and 18 an adder which selects either of the data of the N-register 16 and the P-register 17 depending on whether the data held in the error register 14 is positive or negative and adds the selected data to the data of the error register 14.
FIG. 8 shows a relationship among the slope of a line, an X coordinate value of the X-counter 11, a Y coordinate value of the Y-counter 12 and data contained in the region code register 13, the error register 14, the P-register 17 and the N-register 16, in the embodiment shown in FIG. 7. In a row A, outputs of the region code register 13 are shown and correspond to the regions divided by every 45 degrees. In this table, P designates a P-register value; N an N-register value; S an error register value; X and X-counter value; and Y a Y-counter value. Assuming that the coordinate of the start point of a linear line is (XS, YS) and that the coordinate of the end point is (XE, YE), |X| is the absolute value of the difference between the X coordinate values of the start and end points, or |XS-XE|, and |Y| is the absolute value |YS-YE| of the difference between the Y coordinate values of the start and end points.
FIG. 9 illustrates an example of pixel generation and an operation of the present embodiment shown in FIG. 7 will be explained by referring to FIGS. 5, 8 and 9. Assuming that a line has the start point at the coordinate (1, 6) and the end point at the coordinate (4, 1) as shown in FIG. 9, it is seen from FIG. 5 that the region code corresponding to this line is "110" based on the logic earlier described. The absolute value |X| of the difference between the X coordinate value of the start point and the X coordinate value of the end point is 3, while the absolute value |Y| of the difference between the Y coordinate value of the start point and the Y coordinate value of the end point is 5. According to a calculation equation based on the Bresenham algorithm corresponding to the region code "110" in FIG. 5, P can be obtained as -4, N as 6 and the initial value of S as 1. These parameters are generated and given to the straight line generator. Thus P is loaded in the P-register 17, N in the N-register 16, S in the error register 14 and A in the region code register 13.
A general operation of the straight line generator shown in FIG. 7 will now be explained. A signal representing a positive or negative sign is fed from the error register 14 to the control logic 15. The control logic 15, in reference to the data of the region code register 13, transmits commands for operation to the X-counter 11 and the Y-counter 12. The adder 18, in reference to the data of the error register 14, selects one of the registers and adds the content of the selected register to the content of the error register 14.
Referring to FIG. 8, a concrete example of drawing a line described above will next be explained. Since a value of S at the start point of the line is 1 and therefore the sign is positive, the straight line generator operates, as shown in FIG. 8, to increase the X coordinate value X by 1, decrease the Y coordinate value Y by 1 and add the increment P to S.
The case as above described will next be explained with reference to FIG. 7. When a signal indicating that the sign is positive is sent from the error register 14 to the control logic 15, the signal causes the control logic 15 to recognize that the region code is 110 by referring to the data of the region code register 13, and to instruct the X-counter 11 to be incremented by 1 and the Y-counter 12 to be decremented by 1, as shown in FIG. 7. The adder 18 selects the P-register 17 as the register the data of which is to be added to the data of the error register 14 by referring to the sign of the data of the error register 14, and adds the data "1" of the error register 14 and the data "-4" of the P-register 17 so as to set "-3" in the error register 14. The X counter 11 is then incremented by 1 and outputs the X coordinate value "2", while the Y-counter 12 is decremented by 1 and outputs the Y coordinate value "5". In this way, the coordinate (2, 5) of the pixel 42 next to the starting point is generated.
Next, how a second pixel is generated will be explained by referring to FIG. 8. Since S is "-3" at the coordinate (2, 5) of the pixel 42, the sign is negative and the straight line generator operates such that there is no change in the X coordinate value X, that the Y coordinate value Y is decremented by 1 and that the increment N is added to S, as shown in FIG. 8.
This case will next be explained by referring to FIG. 7. When a signal indicating that the sign is negative is fed from the error register 14 to the control logic 15, the control logic 15 refers to the data of the region code register 13. Since the region code is "110", the control logic 15 instructs the X-counter 11 not to be changed and the Y-counter 12 to be decremented by 1. In reference to the sign of the data "-3" of the error register 14, the adder 18 selects the data "6" of the N-register 16 as data to be added to the error register 14 and adds the data "-3" and "6", thereby setting the resultant value "3" in the error register 14. The X-counter 11 still outputs the same value "2" and the Y-counter 12 decrements the Y coordinate value by 1 and outputs 4. In this manner, the coordinate (2, 4) of the pixel 43 is generated.
By repeating the above-described operation from the coordinate of the start point to the coordinate of the end point, the coordinates of pixels are generated for interpolation between the start point and the end point. The number of such repetition depends on a value of the number of points T to draw a line to be input to the control logic 15. Since T=|Y|+1=6 in this example, the above-mentioned operation is repeated five times except for the starting point. FIG. 9 illustrates the pixel generated by repeating the above-described operation.
The region code (b2 b1 b0) which characterizes the present invention will be further explained here. As shown in FIG. 5, the region code b0 divides the region into two parts, or the left region and the right region. The region code b1 divides the region into two parts, or the upper region and the lower region. Accordingly, when these regions codes b1, b0 are combined together, it is possible to identify four regions, or the upper-left, upper-right, lower-left and lower-right regions. Furthermore, the region code b3 divides the region into two parts in accordance with which of the X axis or the Y axis becomes the main axis by putting the borderlines on lines having the inclination angles of 45° or 135°. Accordingly, all the angles (360°) may be covered by eight region codes provided by b2 b1 b0. The control logic 15 controls operations of the X-counter and the Y-counter, respectively, for eight region codes in correspondence to the region codes which thus cover the entire region, so as to generate pixels. By employing such region codes as described above, exchange between the start point and the end point as well as between an X coordinate value and a Y coordinate value may become entirely unnecessary.
According to the present invention, since pixels are generated by using the Bresenham algorithm, a dividing circuit may be omitted and all arithmetical operations may be conducted using integers, whereby high-speed line drawing may be possible. Furthermore the operations of the X-counter 11, the Y-counter 12 and the error register 14 may be automatically indicated according to the region codes covering 360 degrees and the sign of the error register 14, whereby straight line may be generated in any direction.
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A straight line generator for line drawing in a discrete coordinate system utilizing the Bresenham algorithm. A first counter holds an X coordinate value and is capable of incrementing and decrementing the X coordinate value and a second counter holds a Y coordinate value and is capable of incrementing and decrementing the Y coordinate value. A region code which depends on the slope of the line within the range of 360 degrees is stored. An error term obtained from the Bresenham algirithm is also stored. Responsive to the region code and the error term, increments of the first and second counters are controlled. Positive and negative added parameters which vary the error are stored in registers. Either of the date in the register is selected in accordance with the sign of the error term so as to be added to the error term.
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FIELD OF INVENTION
[0001] This invention relates to methods and apparatuses for providing treatment or promoting health through the application of resonant electromagnetic radiation to the body in order to balance acupuncture points. The measurable resonant frequencies of substances that have the ability to balance acupuncture points have been cataloged in electronic devices in prior art. The resonant signals derived from these substances have been duplicated and stored in these devices so that they may be applied to a subject that wishes to balance acupuncture points. It is my idea and invention to use a holding device with these substances encased in a waterproof compartment allowing these resonant signals to balance the acupuncture points without the use of needles or electronic devices.
SUMMARY OF INVENTION
[0002] The invention relates to a method and apparatus for holding substances on the body that have been found to balance acupuncture points. The apparatus is a holding device which may be a patch, locket, jewelry, belt or may be incorporated into clothing. The holding device has a waterproof non transdermal compartment that contains these particular substances. This substance may be a natural or manufactured substance such as a food, a chemical, animal dander, pollen, a pharmaceutical drug, homeopathic remedy, herb, vitamin, mineral or a biological organism. From this list of substances, the inventor of U.S. Pat. No. 6,142,927 has observed 40,000 different substances that produce resonant frequencies that have a balancing effect on acupuncture points. They are selected by their ability to send out resonant signals that have been proven to balance acupuncture points. If a substance is found to balance the electrical resistance across an acupuncture point then it may be worn by a subject to be afforded the therapeutic effect of continually balanced acupuncture points. It has been noted that if an operator measures the resistance at acupuncture point and then places a substance at or near the subject, with all other variables remaining the same, and repeats the measurement and the resistance becomes balanced then the substance may be considered a source of balancing.
[0003] As stated above the inventor of U.S. Pat. No. 6,142,927 has produced 40,000.00 substances that produce resonant frequencies that are able to balance acupuncture points. In this patent he then replicates these resonant signals in an electronic device that he has patented. As stated in his patent these product signals that normalize acupuncture points are taken from products that may be vitamins, herbs, minerals, foods (nutrients including amino acids), homeopathic remedies, herbs, animal dander, chemicals, pharmaceutical drug, pollen or biological organisms. My invention eliminates the use of this electronic device. Instead the acupuncture points are effected by holding these same substances next to the body so that the resonant signals can directly balance the acupuncture points.
[0004] Therefore, by using appropriate substances from the list above that have been found to balance acupuncture points, therapy can be administered continually by wearing such a holding device. From this list of substances are nutrients (including amino acids). This fact is pertinent to the following observed example of the utility of this invention.
[0005] According to The Journal of Chinese Medicine, no. 94, October 2010, (Immediate Effect of Acupuncture on Strength and Performance, a randomized, control crossover trial, European Journal of Applied Physiology) balancing of acupuncture points shows an increase in muscle strength. Also, in The Journal of Strength and Conditioning Research 24 (5) 1421-1427 2010 reviewed studies show the use of acupuncture in resistance and endurance sports activities demonstrates increase muscle strength and power.
[0006] Increased muscle strength by the topical placement of nutrients including amino acids in a non transdermal holding device has been claimed by my U.S. patent application Ser. No. 10/302,527 entitled Method for Increasing Muscle Strength. Subsequently, the topical placement of amino acids in a non transdermal apparatus to increase muscle strength has been claimed by U.S. patent application Ser. No. 12/915,419 entitled Biomolecular Wearable Apparatus. Both application use similar bench press trials on athletes to demonstrate this utility.
[0007] Therefore, nutrients (including amino acids) cause normalization of acupuncture points. This normalization of acupuncture points has been associated with increased muscle strength. The topical placement of amino acids and nutrients has been demonstrated to improve muscle strength in two independent double blind studies from these two applications cited above.
[0008] The device and method thus offers therapy on the body that will increase muscle strength. While this is an example of the method and apparatus, it is by no means the only ailment or problem that can be treated by balancing acupuncture points using this method and apparatus. In fact, this applicant does not identify any limits or problems for which the human body may be treated by this method and apparatus, the utilization of the present invention is only limited by the resonant signals that are produced by the particular substance or substances in the holding device that have the ability to balance acupuncture points.
[0009] In conclusion, the invention relates to an apparatus and method which comprises a holding device containing a waterproof compartment containing substances that give off natural frequencies that normalize acupuncture points. Therefore by placement of the said device on the surface of the body the utility of the invention may be realized. The utility of the invention is the balancing of acupuncture points that is afforded continually by wearing said holding device. The advantage of this invention over prior art is that it does not utilize needles or electrical devices which are cumbersome, uncomfortable and require the need to go to a health care professional to receive therapy. In addition the therapy may be afforded continually while wearing the holding device.
DETAILED DESCRIPTION OF INVENTION
[0010] The invention utilizes the ability of substances to send out resonant frequencies that have the ability to balance acupuncture points. This ability of these resonant frequencies to affect resistance readings across acupuncture points has been measured using an ohmmeter. In U.S. patent #'927, the method of finding substances that can resonate with acupuncture points and have a balancing effect on these points is outlined. My invention simply takes these substances, places them in a non transdermal holding device, and this results in balanced acupuncture points while wearing the device. The holding device must only secure the resonant producing material to the surface of the body. Specific locations on the body are not required since according to '927 the substance has only to be brought near the body to balance acupuncture points. The method of securing these resonant producing materials on the body will become clearer after the following description of some of the various holding devices possible. The various types of holding devices that together with the active principle (substance which gives off resonant frequencies that can balance acupuncture points) make up the invention are illustrated for the purpose of illustration and without restriction.
[0011] FIG. I A. This illustrates a hat. The holding device is incorporated in a band ( 1 ) that goes around the circumference of the hat holding the active principle next to the skull.
[0012] FIG. I B. This is a longitudinal cross-section of the band showing the waterproof housing ( 2 ) which makes up the compartment holding the active principle.
[0013] FIG. II A. This pictures the holding device as a locket or disc. This AP view shows the outer plastic covering of the device ( 3 ), a clasp ( 2 ), and chain ( 3 ) which allows the device to hang around the neck of the subject at locations on the chest or solar plexus.
[0014] FIG. II B. This pictures a cross sectional view of the locket illustrating the plastic membrane ( 4 ) and the resulting waterproof compartment containing the active principle.
[0015] FIG. III A. This illustrates an AP view of a pedal device which may be a shoe, a pedal insert, or the base of a sandal. The dotted outline indicates the position of the active principle which is placed between a. fabric, leather material or some other appropriate material ( 1 ) that pedal inserts could be made of.
[0016] FIG. III B. This illustrates a longitudinal cross section of this pedal device. The outer covering ( 2 ) of the device may be composed of leather, plastic, or rubber making a waterproof housing ( 3 ) which contains the active principle ( 4 ).
[0017] FIG. IV A. This pictures the holding device as a belt. This AP view shows the outer covering ( 1 ) of the belt which is preferably leather, but may be plastic or other material. The dotted line indicates the location of the active principle which would be held next to the waist in this particular device.
[0018] FIG. IV B. This is a longitudinal cross section of the belt illustrating the outer covering ( 1 ) that surrounds a waterproof compartment that may be in the form of a plastic insert ( 2 ) which surrounds the active principle ( 3 ).
[0019] FIG. V A. This pictures an AP view of a holing device in the form of veterinary apparel. In this case a horse blanket is illustrated. The dotted line indicates the area where the active principle is located which is between the outer fabric and the under surface of the horse blanket.
[0020] FIG. V. B. This is a longitudinal cross sectional view of the horse blanket as a holding device. The outer fabric ( 2 ) of the device surrounds the waterproof housing ( 3 ) which houses the active principle ( 4 ).
[0021] FIG. VIA. This depicts a drawing of beads or stainless steel or ceramic balls which are 20× the actual size. The balls are hollow and constructed of waterproof material that can compose a holding device.
[0022] FIG. VIB. This pictures a magnified cross section of one of these hollow balls illustrating the waterproof outer shell ( 1 ) and the compartment ( 2 ) which contains the active principle.
[0023] FIG. VI C. When these balls are mixed with dental cement or amalgam, they can form a holding device that can be incorporated into a filling affording the envisioned therapeutic effect continually. Thus an ordinary filing is transformed into a therapeutic device.
[0024] FIG. VII A This pictures a mattress ( 1 ) that has the active agent sandwiched between two layers of fabric.
[0025] FIG. VII B . This pictures a longitudinal cross section of the mattress. A waterproof compartment ( 3 ) lies under the fabric of the mattress ( 2 ). This compartment ( 3 ) contains the active principle ( 4 ) which can supply the envisioned therapeutic effect while resting.
[0026] FIG. VIII A. This depicts a hollow spool of thread. In the magnified view ( 1 ) of the thread, the thread is shown to be hollow allowing the active principle to be incorporated into the resulting waterproof chamber. The resulting fiber can be woven into various articles of clothing that would provide the envisioned therapeutic effect while being worn.
[0027] FIG. VIII C. This illustrates the various articles of clothing when such fibers are used in producing clothing. Specifically, a shirt ( 6 ), gloves ( 7 ), pants ( 8 ), and socks ( 9 ) are illustrated.
[0028] FIG. IX. A. This illustrates a watchband as a holding device. The active principle is sandwiched between two pieces of leather which make up the watchband.
[0029] FIG. IX B. This illustrates a cross section of the watch band. The leather material ( 1 ) surrounds a waterproof plastic insert ( 2 ) which contains the active principle ( 3 ).
[0030] FIG. X A This pictures an AP view of a ring that can act as a holding device. It may be composed of a metal such as gold, silver, platinum, copper, etc.
[0031] FIG. X B As seen in this cross sectional view, the hollow chamber of the ring can act as a holding device for the active principle thus providing the envisioned therapeutic response while being worn.
[0032] FIG. XI. A. This illustrates the holding device as a non transdermal patch. In this AP view the plastic covering (A) forms a compartment (B) containing the active principle. The patch is held on various locations on the body with a medical adhesive (C).
[0033] FIG. XI. B. This pictures a cross sectional view of the non transdermal patch. The plastic lining (A) forms a waterproof compartment (B) containing the active principle. A medical adhesive (C) is used to secure the patch to the skin.
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A method of balancing acupuncture points by wearing a holding device that includes a waterproof container containing substances that give off resonant frequencies that have been found to balance acupuncture points allowing the wearer to receive therapy continually by wearing such a holding device. The holding device may be in the form of a locket, jewelry, patch with a medical adhesive, belt, pedal device, or incorporated into clothing and veterinary apparel.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to an aiming apparatus for archery bows and particularly to a mounting system which may interchangeably mount a telescopic or open type sighting elements and which is highly adjustable for different uses and usage conditions.
It is frequently desirable to incorporate aiming systems with archery bows in order to increase their accuracy. Numerous approaches for providing enhanced aiming accuracy of bows have been previously employed. Numerous designs of open type sights are currently available for use with archery bows. These sights normally comprise a pin or other sighting member fixed to the bow which the archer lines up with the intended target in order to provide bow aiming. Telescopic sights for bows are also known. Mounts for such sights support the tubular optical sighting instrument and provide an adjustment of the positioning and aiming of the telescopic sights. A particular archer may choose to use either of these types of aiming systems under different circumstances. For instance, a telescopic sight might be preferable for target shooting where high accuracy is extremely important and/or where long distances are encountered. However, a telescopic sight might be difficult to use during some hunting conditions when shooting at moving targets due to the difficulty in locating the target using an enlarged image from a telescopic sighting device. Open type sights are generally superior in conditions calling for rapid identification and location of the target, for example, occurring during hunting situations. Open type sights may also be preferable to the user when shooting in low light conditions. As a result, a convertible sight mounting system would be particularly advantageous. For any type of bow sight, a high degree of adjustability is needed to accommodate various individuals and usage situations.
Accordingly, a principal aspect of this invention is to provide a bow mounted sighting system which is easily convertible between a telescopic sight and an open sight enabling archers to quickly change between sighting systems in accordance with their needs or inclinations.
An additional aspect of this invention is to provide a sight mounting system which permits a wide range of adjustment thereby providing means for properly locating the sighting element positions and angular orientations.
The principal aspects of this invention are achieved by providing a bracket assembly having two rotational degrees of freedom enabling the sighting system to be pitched forward and back and rotated from side to side. In addition, means are provided to vary the position of the sighting element vertically and laterally with respect to the bow. A telescopic or open sight is attached to the mounting system disclosed herein and either may be adjusted in the directions mentioned. An open sight comprising an elongated bracket having spaced sighting elements is also disclosed.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates upon a reading of the described preferred embodiments of this invention taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic view showing a bow sight mount in accordance with the principles of this invention attached to a bow and mounting a telescopic sight. The system is shown by this Figure in use by an archer.
FIG. 2 is a top elevational view of the bow sight according to this invention shown mounting a telescopic sighting device.
FIG. 3 is a partial front view of the bow sight mount according to this invention particularly showing the means for adjusting the lateral position of a telescopic sighting element.
FIG. 4 is a side elevational view of the sighting system according to this invention shown mounting a telescopic sighting device.
FIG. 5 is a top elevational view of an open sight mounted to the interchangeable sight mounting bracket according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
An interchangeable bow sight mount according to this invention is shown by FIGS. 1 through 4 and is generally designated by reference character 10. As shown in FIG. 1, bow sight mount 10 is affixed to archery bow 12 such that the aiming axis of the sighting apparatus attached to mount 10 is substantially aligned with the user's eye when arrow 16 is drawn as shown in FIG. 1. As is evident from the Figure, the orientation of the aiming axis of the sighting apparatus is fixed by mount 10. Therefore, the archer is not required to maintain a fixed orientation between the drawn arrow 16 and his sighting eye which is necessary when a single point of aiming reference is employed. Aiming systems defining an aiming axis provide enhanced accuracy over single point aiming systems particularly when used by inexperienced users. FIGS. 2, 3 and 4 show the interchangeable bow sight mount 10 in detail.
It is useful to define certain directions in connection with a description of this invention. References to left, right, up, down, vertical, horizontal and lateral are based from the perspective of an archer using the bow when aiming the arrow along a horizontal plane such as is depicted by FIG. 1. The embodiment described herein is useful for a right-handed archer, i.e., one who draws the bowstring with the right hand. A left-handed equivalent to this novel bow sight mount is constructed by employing components which are mirror image reproductions of those described herein.
Bow sight mount 10 is composed of four primary components--bow mounting bracket 18, sliding bracket 19, intermediate bracket 20 and sight mounting plate 22.
Bow mounting bracket 18 is best described with reference to FIGS. 2, 3, and 4. Bow mounting bracket 18 is L-shaped in section comprising two perpendicular legs. First leg 24 forms several mounting slots 26 adapted to receive threaded fasteners 27 affixing bow mounting bracket 18 to bow 12. Slots 26 are oriented such that they extend vertically, thereby permitting adjustment of the vertical position of mount 10 with respect to bow 12. Such adjustment is necessary in order to compensate for the trajectory of an arrow over various target ranges. First leg 24 of bow sight mounting bracket 18 is attached to the right side of the bow as shown by FIG. 2. Second leg 28 of bow mounting bracket 18 extends across the front of bow 12 from first leg 24 and forms a channel extending laterally across the front of bow 12. Bore 29 is threaded to engage fastener 30 which is employed to affix sliding bracket 19 to bow mounting bracket second leg 28.
Sliding bracket 19 is also "L" shaped in configuration having first and second legs 33 and 35 respectively. First leg 33 forms an elongated slot 37 which permits adjustment of the lateral position of sliding bracket 19 with respect to bow mounting bracket 18. This position is adjusted by loosening fastener 30 and sliding bracket first leg 33 within bow mounting bracket second leg 28. In order to provide a means for adjusting the lateral position between brackets 18 and 19 to a predetemined position setting, a graduated scale may be imprinted or attached to one bracket and an index mark imprinted on the other bracket (not shown). Sliding bracket second leg 35 includes a pair of threaded holes 32.
Intermediate bracket 20 also forms an L-shaped section having first leg 34 and second leg 36. First surface 34 includes bore 38 and arc-shaped aperture 40. Bore 38 and aperture 40 are spaced apart the same distance as are holes 32 of sliding bracket 19. A first threaded fastener 42 rotatably mounts intermediate bracket 20 to sliding bracket 19 by engaging one of bow mounting bracket holes 32. A second threaded fastener 44 preferably of the thumb screw variety, passes through washer 46 and engages hole 32 formed by sliding bracket 19. The width of arc-shaped aperature 40 is sufficiently great to avoid interference with the threads of fastener 44 and is bounded by portions of the circumference of circles having a center coincident with the center of fastener 42. Therefore, second threaded fastener 44 may be loosened permitting intermediate bracket 20 to be rotated through a limited angular range about first fastener 42 causing fastener 44 to sweep through aperture 40. Sliding bracket second leg 35 may include graduations which align with an index mark on intermediate bracket second leg 36 such that the rotational orientation of these parts may be reset after adjustment to a particular position. Intermediate bracket second leg 36 forms two threaded holes 48.
Sight mounting plate 22 forms central hole 50 through which threaded fastener 52 rotatably mounts the mounting plate to intermediate bracket 20. Second fastener 54, preferably of the thumb screw variety, passes through washer 56 engaging another of threaded holes 48. Second fastener 54 passes through an arc-shaped aperture 58 formed by plate 22. Aperture 58 is shaped as described in connection with aperture 40 above thereby allowing plate 22 to be rotated through a limited range about fastener 52. The orientation of plate 22 with respect to intermediate bracket 20 may be set to a preselected value by employing graduations on the components which align with an index mark on the other. Sight mounting plate 22 further includes a plurality of threaded holes 60 which are employed to fix a sighting element to sight mount 10.
A mounting system to affix a telescopic sight to sight mount 10 is shown by FIGS. 1, 2 and 4. Telescopic sight mounting yoke 62 includes a bottom plate 64 having holes therein matching holes 60 formed by sight mounting plate 22 enabling yoke 62 to be affixed to the mounting plate by fastener 63. Bottom plate 64 forms a relieved portion 65 necessary to prevent interference with fastener 52. Mounting yoke 62 further forms a pair of arcuate scope nesting portions 66. Caps 68 threadably engage nesting portion 66 to firmly clamp telescopic sight 70 to yoke 62. Telescopic sight 70 is an optical aiming system including an internal recticle preferably with internal means for slightly moving the optical axis of the device with reference to yoke 62. Telescopic sight 70 is the type which forms an objective image a substantial distance from the eye piece such as is commonly used with pistols. A substantial amount of relief is necessary in that the archer's eyes are located some distance from sight 70 during use. The orientation of sight 70 with respect to bow 12 may be adjusted by rotating intermediate bracket 20 with respect to sliding bracket 19 thereby causing the sight to pitch forward and rearward and may be adjusted by rotating mounting plate 22 with respect to intermediate bracket 20 thereby causing sideways rotation of sight 70. Finally, the lateral and vertical position of the sight is adjustable by loosening and tightening fasteners 30 and 27 respectively.
Open sight 72 is shown by FIG. 5 attached to sight mounting plate 22 using threaded fasteners 63. Open sight 72 is an elongated plate structure having sighting element mounted within dovetail grooves 78 and 80 at spaced ends of the sight. Disposed within grooves 78 and 80 are front mounted pin type sighting element 74 and rear mounted notched blade 76 which, when lined up, defines an aiming axis. Open sight 72 forms a relieved portion 73 necessary in order to prevent interference with fastener 52. As was explained in connection with telescopic sight 70, open sight 72 may be adjusted for the individual user. Since open sight 72 includes a pair of spaced sighting elements, a sighting axis is defined which does not require precise positioning of the archer's eye with respect to the bow, thereby enhancing accuracy. Open sight 72 is adjustable in the same manner as sight 70 described above.
In use, bow sight mount 10 may be quickly converted from use in connection with a telescopic sight 70 to use with an open sight 72 and vice versa simply by loosening threaded fasteners 63. A predetermined orientation of each of these sights may be achieved quickly with reference to angular and linear reference marks formed at the intersection between the sight mount parts which are rotatable and slide with respect to one another, as previously detailed.
While preferred embodiments of the invention have been described herein, it will be appreciated that various modifications and changes may be made without departing from the spirit and scope of the appended claims.
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A bow sight mount which interchangeably mounts a telescopic or an open sight. The mounting bracket includes four primary components. A bow mounting bracket is attached to the bow. A sliding bracket engages the mounting bracket and is laterally adjustable with respect thereto. An intermediate bracket is rotatably attached to the sliding bracket and a sight mounting plate is rotatably attached to the intermediate bracket. This configuration permits the sight mounting plate to be rotated about two perpendicular axes and laterally and vertically. A mount for a telescopic sight or an open sight is attached to the sight mounting plate preferably by threaded fasteners. This system provides the archer with the capability to rapidly interchange sights and provides a high degree of adjustability for any type of sight.
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This is division of application Ser. No. 064,872, filed June 19, 1987 now Pat. No. 4,813,730.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to latches for retrievable flow control devices used in oil and gas industries, and more specifically to latches which are utilized to secure or to remove a flow control valve from a mandrel receiver at a subterranean location.
The use of various type latches for such purposes is well known in the oil and gas industries. However, many latches which are currently utilized in the field suffer from a major drawback: the locking ring, in many instances, "wedges" against the locking shoulder of a mandrel, which leads to bending and metal damage of the flow control device or the mandrel receiver, and as a result, to inability of the latching device to secure position of the valve in the mandrel receiver.
Another problem which is often encountered in the oil and gas industries is inability of a retrieval tool to retrieve a valve which is locked downhole. Under these circumstances, all pulling means are usually carried up to the surface, while the valve has only one direction which it can be moved-upward. The valve cannot be retrieved by driving it down through the mandrel and at the present time, the tubing is usually pulled to the surface so that the valve, in such emergency situations, can be retrieved. While such procedure could be acceptable for production on land, no similar benefit could be obtained at an offshore location. A drilling rig will have to be moved away from that particular location and the well will stay dormant until a next workover program is effected which can take as long as five to six years from the time the well is immobilized. This causes not only loss of some pieces of equipment, but what is more important, loss of production time.
SUMMARY OF THE INVENTION
The present invention is designed to solve both of the problems in a simple and straightforward manner. A latching device, in accordance with the present invention, is provided with a cylindrical body, a locking sleeve mounted in surrounding and slidable relationship on the body, a locking ring and a compressible spring which normally urges the locking ring downward so that it rests on top the latch sub which is attached to a flow control device, such as a valve. To prevent wedging of the locking ring against the locking shoulder of the mandrel receiver, and locking ring comprises upper and lower bevelled surfaces which are complementary to the bevelled surfaces of the locking shoulder of the mandrel receiver, so that the surfaces can meet at a common plane when the latching device is driven into the mandrel receiver or pulled up the the surface.
To facilitate retrieval of a flow control device, such as a valve, when all retrieval means have been carried out to the surface or the well is immobilized, the present invention provides for the use of a cylindrical latching sub having a central opening, the internal wall of which is provided with an internal recess above the means of attachment of the latch sub to a latching device, for example. A retrieval tool comprises an upper body and a lower nose portion, and a compressible C-shaped ring is mounted on the nose portion, so that it compresses while the nose portion is being driven into the central opening of the cylindrical latch sub and releases when it reaches the internal recess, thereby effectively locking the retrieval tool within the latching device. The latch sub has also means for secure attachment of the latch sub to the flow control device to be retrieved.
It is therefore an object of the present invention to provide a latching device for positioning and removal of a flow control device from a tubular receiver.
It is a further object of the present invention to provide a latching device with means which prevent wedging of the locking means of the latching device against locking shoulder of the tubular receiver.
It is a further object of the present invention to provide a retrieval tool for retrieval of a flow control device from a tubular receiver when the flow control device is locked downhole and all pulling means have been carried up to the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, partially in cross section, showing the locking ring meeting the locking shoulder of the tubular receiver by a complementary bevelled surface.
FIG. 2 is an elevational view, partially in cross section, showing the position of the locking ring, when it meets by its flat surface a respective flat surface of the locking shoulder of a tubular receiver.
FIG. 3 is an elevational, partially cross sectional view, showing the position of the locking ring and of the released spring when the locking ring passes the locking shoulder of the tubular receiver.
FIG. 4 is an elevational, partially cross sectional view of a locking ring in accordance with the present invention.
FIG. 5 is an elevational, partially cross sectional view showing a retrieval tool entering the central opening of a latch sub.
FIG. 6 is an elevational, partially cross sectional view of the retrieval tool, with the C-shaped locking ring locked in the internal recess of the latched sub.
FIG. 7 is a plan view of the C-shaped ring in an expanded position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, numeral 10 designates the latch of the present invention adapted for use in a side pocket 12 of mandrel 14 in which a flow control device 16, such as a valve, is mounted.
The latch 10 comprises a generally cylindrical body 18 having a shoulder 20 at its upper portion for engagement with a running tool (not shown) designed for positioning the flow control device 16 in the side pocket 12. The lower portion of the latch 10 is provided with threads 22 for threaded engagement with the flow control device 16.
A locking sleeve means 24 is slidably mounted on the cylindrical body 18, and a shear pin means 26 serves to temporarily secure the locking sleeve 24 in its lowermost position in relation to the flow control device 16.
Retrieval of the latch 10 and the flow control device 16 can be achieved through the use of a conventional retrieval tool (not shown) which will engage an upper shoulder 28 at the upper portion of the locking sleeve 24 and, by application of an upwardly directed force, will cause shearing of the pin 26 and movement of the slidable locking sleeve 24 upward in relation to the cylindrical body 18, thus allowing retrieval of the latch 10 and the flow control device 16 which is threadably engaged with the latch 10.
An annular locking ring means 30 is slidably mounted on the sleeve 24 and is provided with upper and lowel beveled surfaces, designated by numerals 32 and 34, respectively. The angle of the bevel is designed to be complementary and to substantially match an angle on a latch lug 40 of the side pocket 12. The advantages of such design are such that there is no "wedging" effect of the ring 30 against the latch lug 40 when a downward force is applied to the flow control device 16, pushing it into the side pocket 12. A progressive downward movement of the flow control device 16, as was noted above, can even cause bending of the flow control device 16 which is, for example, a valve, when the angles of bevel of the locking ring 30 and the latch lug 40 are mis-matched, as is the case with the currently used in the field latching devices.
When such devices are used and the bevels of the locking ring and of the latch lug do not match, there is one point of contact between a lower bevel surface of the locking ring and an upper bevel surface of the latch lug. The latch lug "digs" into the locking ring, causing wedging and even occasional bending of the valve which is being pushed downwardly into a side pocket of a mandrel. In this case, the force which acts upon the beveled surfaces is almost perpendicular to the vertical movement of the latch.
In the case of the complementary, matching angle bevels, in accordance with the present invention, the force acting upon the bevel surfaces is at an acute angle to the vertical. The direction of force acting upon the bevel surfaces in accordance with the present invention is shown by arrow 51 in FIG. 1 of the drawings. The point of contact of the beveled surfaces moves towards the center of the annular locking ring 30, causing the complementary bevelled surfaces to meet at a common plane. Such advantage is not achieved by any other currently used latch known to the applicant.
A spring means 50 is mounted circumferentially about the outside lower portion of the slidable locking sleeve 24, the spring acting against an intermediate shoulder 36 and the annular locking ring 30. The spring 50 serves to retain the position of the locking ring 30 in relation to the flow control device 16, urging the locking ring 30 to rest atop the upper edge 17 of the flow latch sub 15.
FIG. 2 shows a progressive movement of the latch 10 downwardly and the locking ring 30 contacting a flat surface 41 of the latch lug 40 by its corresponding flat surface 31.
The spring 50 is compressed by the locking ring 30 which forces it upwardly. At the same time, the locking ring 30, having an internal diameter greater than an outside diameter of the body 18 and of an enlarged diameter head 42 of the locking sleeve 24, is forced sideways, laterally, to a limited degree, by the flat surface 41 of the latch lug acting upon the flat surfaces 31 of the locking ring 30.
The limited degree of the lateral, sideway movement of the locking ring 30 is made possible by the provision of a reduced diameter portion 38 on the sleeve 24, the portion 38 being formed above the enlarged diameter head 42 of the lower portion of the locking sleeve 24.
A lower shoulder 44 is formed above the reduced diameter portion 38 and, being of a greater diameter than the internal diameter of the locking ring 30, limits its upper movement along the locking sleeve 24 when the locking ring 30 is engaged by the latch lock 40 and the spring 50 is compressed. The vertical distance of the reduced diameter portion 38 is at least as great as the thickness of the locking ring 30 to prevent any wedging effect between the locking ring 30 and the latch lug 40. Still, the outside diameter of the locking ring 30 is greater than the diameter of the shoulder 44, thereby allowing the shoulder 44 to effortlessly pass the latch lug 40, after the locking ring has passed the latch lug 40 as will be described below.
As shown in FIG. 3, orogressive downward movement of the flow control device 16 into the side pocket 12 results in positioning of the locking ring 30 below the latch lug 40. The compressed spring 50 releases, forcing the locking ring 30 downward, to its original position atop the latch sub 15, thereby locking the latch 10 and the flow control device 16 in the side pocket 12 of mandrel 14. The running tool (not shown) is then disengaged from shoulder 20 leaving the flow control device 16 inside the side pocket 12. The operation of the shoulder 44 is also described in my U.S. Pat. No. 3,827,493, issued on Aug. 6, 1974, the disclosure of which is incorporated herewith by reference.
Retrieval of the flow control device, under normal conditions, can be accomplished by conventional methods and tools, by engaging the upper shoulder 28, shearing the shear pin 26 and pulling the locking sleeve 24 upwardly. While the sleeve 24 slides upwardly on the body 18, the spring 50 releases, to some degree, leaving the locking ring 30 seated above the edge 17 of the flow control device 16 and below the enlarged diameter head 42 of the locking sleeve 24.
The lower bevel surface of the latch lug 40 is contacted by the complementary angle upper surface 32 of the locking ring 30, which then slides upward and, upon contact of the flat surfaces 41 and 31 of the latch lug 40 and the locking ring 30, respectively, moves laterally towards the body 18 to pass the latch lug 40 and allow retrieval of the flow control device 22 from its position in the side pocket 12 of mandrel 14.
In some circumstances though, the flow control device, such as valve, cannot be retrieved by the above-described conventional method.
Sometimes, a latch post is parted at its threaded connection, the thread can be stripped or vibrated loose. When this occurs, the conventional retrieval tools are of little use, since there is no shoulder against which the latch can be pulled out. The latch is positioned inside the side pocket of a mandrel, and the retrieval means have been carried out to the surface. Yet, a valve has to be retrieved, it has a no-go latch sub mounted above it and it can be moved only in one direction-upward.
In accordance with the present invention, an improved retrieval means are provided for such emergency situations.
FIGS. 5-6 show an improved retrieval means, comprising a retrieval tool as used in combination with an improved no-go sub of a locking latch. As was described above, this sub is left inside the side pocket when the stripping has been accomplished. The improved latch sub 100 comprises an upper 102 and lower 104 cavities formed by a central opening 105 which is made in the annular wall 106, the opening extending the length of the latch sub 100. The internal wall 108 of the opening is provided with an upper 110 and lower 112 threaded portions disposed in the upper 102 and lower 104 cavities, respectively.
The upper threads 110 terminate a distance below an uppermost edge 114 of the latch sub 100 and are designed for engagement with matching threads (not shown) of a locking latch (not shown). The lower threads 112 extend substantially to the lowermost end 116 of the latch sub 100 and are designed for engagement with matching threads 118 of a valve 120, thereby ensuring a fixed position of the valve 120 in relation to a locking latch.
An internal annular rib 122 extends inwardly from and substantially perpendicularly to the internal wall 108 approximately midway between the uppermost edge 114 and lower end of the latch sub 100, dividing the central opening 105 into the upper 102 and 104 cavities, as was described above.
As further shown in FIG. 6, the internal wall 108 is provided with an annular recess means 124 above the upper threaded portion 110. The recess 124 is formed by an upper bevel surface 126, intermediate flat surface 128, having an enlarged diameter, and lower bevel surface 130.
An improved retrieval tool 200 which is utilized for retrieving the valve 120 in accordance with the present invention comprises a tool body 202 and a retrieval tool nose portion 204, which is fixedly and detachably connected (such as, for example, by threads) to the lower end of the tool body 202. Alternatively, the tool body 202 and the retrieval tool nose portion 204 can be made integral, forming a unit. The nose 204 comprises a first frustoconical portion 206, a middle, enlarged diameter cylindrical portion 208 and a second, downwardly facing frustoconical portion 210. A groove 211 is formed in the apex of the second frustoconical portion 210, the groove designed to receive torque, applied to the nose portion, as will be described in more detail below.
A lower shoulder 212 is formed by the top of cylindrical portion 208, and an upper shoulder 214 is formed by a lower end of the tool body 202 at the level of its engagement with a smaller diameter upper end of the first frustoconical portion 206.
A C-shaped locking ring means 216 is positioned in circumferentially surrounding relationship on the first frustoconical portion 206 and can move freely vertically between the vertical limits set by the upper shoulder 214 and the lower shoulder 212. Internal diameter of the C-ring 216 is such that it can move laterally, to some degree, on the frustoconical portion 206 but is prevented from sliding downward by the lower shoulder 212 and moving upward--by an upper shoulder 214.
Operation of the retrieval tool 200 will now be described in reference to FIGS. 5 and 6.
As the retrieval tool 200 is lowered into the opening 105 of the latch sub 100, the nose 204 enters the cavity 102, and frustoconical portion 210 and cylindrical portion 208 pass through recess 124. The C-ring 216 collapses and moves through the opening 105 into recess 124, sliding along an upper bevel surface 126 into the middle portion 128, which, as was mentioned above, has a greater diameter than the overall diameter of the central opening 105, and which vertical dimensions are at least as great as the thickness of the C-ring 216.
After the C-ring 216 has reached the middle portion 128 of the recess 124, it expands. Then a pulling force is applied to the retrieval tool 200, forcing the C-ring 216 to engage the lower shoulder 212 and rest on it, while sliding along the upper bevel surface 126 as can be seen in FIG. 5. The C-ring 216 is held in its expanded position, while the pulling force creates a shearing effect through the center of the C-ring 216, crosswise around its periphery.
In order to prevent shearing of the C-ring 216, it is designed and made of a high strength carbon steel wire which is strong enough to withstand the forces applied to the C-ring 216 during operation.
It should be noted that the material from which the C-ring is made is not limited only to the material mentioned above, but any material which possesses the same physical qualities will be acceptable, provided it can withstand the shearing force.
Continued application of the pulling force causes a positive locking effect between the retrieval tool 200 and the valve 120, after which the valve 120 can be retrieved from its position inside the side pocket and lifted to the surface. Upon arrival on the surface, the retrieval tool is separated from the valve 120 by first removing the latch sub 100, then applying torque to the portion 210 at the groove 211, thus separating the retrieval tool nose 204, latch sub 100 and the valve 120 from the retrieval tool body 202. The latch sub 100 can then be cut laterally through the annular wall 106 at the level of recess 124, after which the valve can be easily separated from the latch sub 100.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes may be made within the scope of the appended claims without departing from the spirit of the invention.
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A latching device for locking and removal of a flow control device from a mandrel receiver comprises a cylindrical stem, a locking sleeve slidably mounted upon the stem, an annular locking ring mounted for a limited axial movement along the lower portion of the locking sleeve and a compression spring. The annular locking ring has upper and lower bevel surfaces which are complementary to bevel surfaces of a mandrel receiver.
an improved retrieval device is disclosed for retrieval of a valve which is locked within the mandrel receiver, the device comprising a cylindrical body having a central opening and an internal wall with a recess and a retrieval tool provided with a compressible C-shaped ring for locking engagement with the recess formed in the cylindrical body, thereby allowing retrieval of the cylindrical body, along with the well tool which is securedly attached to the retrieval device.
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BACKGROUND OF THE INVENTION
This invention relates to a method and an apparatus for feeding rod-like material (hereafter "workpiece") to a severing machine, such as a frame saw, a circular cold saw, a band saw or the like. The workpiece which is supported on a machine table and on a feeding device arranged upstream of the machine table as viewed in the direction of feed, is, during the severing operation, clamped in the zone of the cutting plane between at least two jaws which may be opened and closed in a direction transverse to the direction of feed. Between two cutting steps the workpiece is advanced (fed) to the severing machine by means of at least two feed jaws (forming part of the feeding device) which can be opened and closed in a direction transverse to the direction of feed. This cyclical feeding operation which is usually automatically controlled by a preset control device, involves the difficulty in maintaining the final length portion of the workpiece (after the consecutive severing steps) as short as possible in an effort to reduce waste.
According to the prior art devices the clamping shoes are divided or have a notch in the zone of the cutting plane of the saw blade so that they grasp the workpiece at both sides of the cutting plane. The workpiece feed is effected by opening the feed jaws subsequent to a cutting step in order to execute a return motion of the feed jaws to an extent which equals the length of the next feed, while the leading end of the rod is maintained clamped by that part of the clamping jaws which are situated at the feed side (that is, at the upstream side) of the cutting plane. Then the feed jaws again grasp the workpiece and in an open position of the clamping jaws, advance the workpiece to the desired extent. Thereafter, the clamping jaws are closed and the consecutive cutting operation is started. In this arrangement the minimum remaining workpiece length is determined by that portion of the clamping jaws which lie at the upstream side of the cutting plane as well as a minimum length which is just sufficient to be still securely grasped by the feed jaws.
In order to reduce the residual length (waste length) of the workpiece, it has been known to provide the feed-side part of the clamping jaws with a recess into which the feed jaws may telescope to arrive closer to the cutting plane. Even in such an arrangement, the waste length of the workpiece is substantial and may be many times greater than the programmed length to be severed, so that waste lengths are obtained from which at least one more programmed length portion could have been severed.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method and apparatus for reducing the waste length of rod-like workpieces to the minimum necessary to ensure that the workpiece is still securely grasped by the feed jaws. It is a further object of the invention to modify known means without additional expense.
These objects and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the feed jaws are, subsequent to the feeding step and the closing of the clamping jaws, but prior to the completion of the cutting step, opened and moved away from the cutting plane by an extent that corresponds to the subsequent feed stroke and are thereafter closed again to grasp the workpiece anew.
The above-outlined operational cycle of the feed jaws according to the invention thus ensures that the workpiece is already grasped by the feed jaws and is thus ready for the feeding operation before the cutting operation is terminated. It is thus no longer necessary to hold the leading end of the workpiece by the clamping jaws after execution of the cutting step while the feed jaws are executing their return motion and again grasp the workpiece.
According to a further advantageous feature of the method according to the invention, the feed jaws are opened prior to the beginning of the cutting step, then are moved away from the cutting plane by an extent that corresponds to the subsequent workpiece feed and then closed again. In this way it is ensured that during the cutting operation the workpiece is also held firmly at a location which is at a substantial distance from the cutting plane so that oscillations and/or tilting forces can have no effect.
According to a further feature of the inventive method, the workpiece end which is upstream of the cutting plane (as viewed in the direction of feed) is supported against the cutting force during the cutting operation on the side which extends in the direction of the cutting force which, in turn, is generally parallel to the machine table. This measure is particularly advantageous when very long length portions are being cut from the workpiece and consequently, the feed jaws have a significant distance from the clamping jaws during the cutting operation. Under such circumstances, towards the end of the cutting step, dependent upon the cutting forces, on the remaining terminal portion of the workpiece a transverse force may be exerted which cannot be fully counteracted by the feed jaws, so that in the absence of the above-noted additional support, the workpiece could get out of alignment.
As a result of the method according to the invention, the apparatus for performing the method can be so structured that the clamping jaws, as viewed in the direction of feed, are located exclusively downstream of the cutting plane and further, the feed jaws can be advanced up to the immediate vicinity of the cutting plane.
By virtue of the fact that the workpiece is grasped by the feed jaws as early as prior to the completion of the cutting step, it is no longer required--as noted above--that the leading end of the workpiece be still held by the clamping jaws after the cutting operation, so that the part of the clamping jaws which heretofore has been arranged at the upstream side of the cutting plane can be dispensed with. This, in turn, permits to advance the feed jaws during feed immediately up to the cutting plane, so that after the last cut from each workpiece there remains only such a minimal length (waste length) which is needed for being securely grasped by the feed jaws.
For the above-discussed support of the workpiece end at its side lying in the effective direction of the cutting force, there is provided a pivotal pawl which, in its operative position, is in alignment with that clamping jaw face which is situated on the same side of the workpiece. The pawl may be pivoted in the feeding direction away from the cross-sectional zone of the workpiece against a spring force. The pawl is shiftable as a unit with the clamping jaw which is displaceable transversely to the direction of feed. The pawl supports the rod-like workpiece particularly towards the end of the cutting step; during the feeding motions of the feed jaws, however, the pawl can be pivoted by one of the feed jaws out of the way from the cross-sectional zone of the workpiece.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of a frame saw according to the prior art, as viewed in the direction of the arrow I of FIG. 2.
FIG. 2 is a schematic top plan view of the prior art structure shown in FIG. 1.
FIG. 3 is a top plan view of a preferred embodiment of the invention.
FIG. 4 is a top plan view of an enlarged detail of the structure shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to FIG. 1, there is shown a conventional severing machine, more particularly, a frame saw which has a machine stand 1, a saw frame 2 and a saw blade 3 held taut therein. The machine stand 1 comprises a machine table 4 on which a rod-like workpiece (not shown in FIG. 1) to be severed is clamped by means of clamping jaws 5 and 6. In the illustrated example, the clamping jaw 5 is stationarily mounted, while the clamping jaw 6 can be opened and closed by means of a power cylinder assembly 7.
Turning now to FIG. 2 which illustrates the frame saw of FIG. 1 in top plan view, a conventional workpiece feeding device generally designated at 8 is arranged upstream of the frame saw, as viewed in the direction of workpiece feed. The feeding device 8 essentially comprises a stand 9 on which there are mounted rotatable rolls 10 for supporting the workpieces and a pair of feed jaws 11 and 12. Of the two feed jaws 11 and 12, the feed jaw 12 may be displaced transversely to the feed direction by a power cylinder assembly 13 for closing and opening the feed jaw pair. Between the feed jaws 11 and 12 there is provided a backup support 14 for the workpieces. The feed jaws 11, 12 are, together with the backup support 14, displaceable as a unit on the stand 9 for example, by means of a spindle drive actuated by a motor 15, towards and away from the frame saw. Thus, the feed jaws 11, 12 are displaceable parallel to the arrow I in the plane of the drawing FIG. 2.
As it may be further observed in FIG. 2, the clamping jaws 5 and 6 have respective clamp jaw parts 16 and 17 which are situated at the feed side (upstream side) of the cutting plane defined by the saw blade 3. The clamping jaw parts 16 and 17 which characterize prior-art arrangements, have the function to firmly hold the leading end of the rod-like workpiece while, after the completion of a cutting step, the feed jaws 11 and 12 are opened and are shifted away from the saw and then are again closed in order to feed the consecutive length portion of the workpiece in the direction of the saw. The clamping jaw parts 16 and 17, however, affect the size of the waste length of the workpiece (which can no longer be further severed), inasmuch as the waste length has to be, in addition to the minimum length required for the feed jaws 11 and 12 to securely grasp the workpiece, longer by an amount corresponding to the width of the clamping jaw part 16 and 17 as measured in the direction of feed.
Turning now to FIG. 3, there is illustrated the severing machine and the feeding device 8a according to the invention. In FIG. 3 components that are identical to those shown in FIG. 2 are designated with the same reference numerals, but are not referred to again in the description except if they are of significance regarding structural and/or operational features of the invention.
In FIG. 3, the cutting plane 20 defined by the saw blade 3 is designated in broken lines in the zone of the saw frame 2. As seen in FIG. 3, the clamping jaws 21 and 22 are situated only on the downstream-side of the cutting plane 20 (as viewed in the direction of feed). Thus, as opposed to the prior art shown in FIG. 2, the clamping jaws do not have any parts that extend beyond the cutting plane 20 into the upstream side thereof, that is, into that side where the feeding device 8a is located. This condition permits the feed jaws 11 and 12 to be advanced to the immediate vicinity of the cutting plane 20 during workpiece feed so that the residual workpiece length (waste length) has to be only of such a size that the workpiece can still be securely gripped by the feed jaws 11 and 12 for performing the last cut on the workpiece.
The feeding device 8a has a limit switch 23 which causes stoppage of the feed motion of the feed jaws 11 and 12 at the moment when their leading edge arrives at the immediate vicinity of the cutting plane 20 at the upstream side thereof. The feeding device 8a further has another limit switch 24 which is adjustable and determines the length of the return stroke of the feed jaws 11 and 12 to thus determine the length by which the workpiece is advanced. This magnitude is settable with the aid of a fixed scale 25' along which the limit switch 24 may be shifted.
The method of feeding the workpieces according to the invention which makes possible to dispense with the clamping jaw parts 16 and 17 shown in FIG. 2 will now be discussed in conjunction with FIG. 4.
First, the rod-like workpiece 25 is brought into its illustrated position by the feed jaws 11, 12 which assume their position immediately adjacent the cutting plane 20 as shown in solid lines. During the feed, the clamping jaws 21 and 22 were open and now, in the solid-line end position of the feed jaws 11, 12 they close. Thereafter, prior to the beginning of the severing operation but not later than just prior to the completion thereof, the feed jaws 11 and 12 are opened and are displaced into the new feed position 11' and 12' (shown in broken lines) and there, again not later than prior to the completion of the cutting step, they are closed and thus grasp the workpiece. Upon completion of the cutting step, the clamping jaws 21, 22 open by virtue of the clamping jaw 22 moving transversely to the direction of feed into the phantom-line position 22' and thus the consecutive feed may take place with the aid of the feed jaws 11 and 12. Thereafter, the above-described cycle is repeated.
As seen in FIG. 4, the residual length (waste length) R can be very short and need not be longer than what is necessary to ensure that the last workpiece portion--from which a programmed length will still be cut--can still be securely grasped by the feed jaws 11 and 12.
In cases where, during each cycle, large workpiece lengths are to be advanced, and thus the feed jaws 11 and 12 have, precisely at the time the severing operation is completed, a substantial distance from the cutting plane 20, it is advisable to additionally support the workpiece 25 at a location close to the clamping jaws 21 and 22 at that side towards which the cutting force derived from the operation of the saw blade is directed. In case of a substantial distance of the feed jaws 11 and 12 from the cutting plane 20, the transverse force which depends from the cutting force and which is exerted on the workpiece 25 towards the end of the cutting operation, may reach such a magnitude that the feed jaws 11 and 12 are no longer capable of preventing a misalignment of the workpiece in the vicinity of the cutting plane 20. Thus, for effecting the above-noted additional support of the workpiece 25, there is provided a pawl 26 which is mounted on a component 27 by means of a pin 28 for pivotal motion about an axis perpendicular to the plane of the drawing FIG. 4. The component 27 is integral with the moving member of the power cylinder assembly 7 and thus moves in unison with the clamping jaw 22 during the opening and closing motions thereof. The pawl 26 is biased by a spring 29 which seeks to pivot the pawl 26 into its phantom-line position against a stop 30 supported on the component 27. In the phantom-line position, the leading edge 31 of the pawl 26 is coplanar with the clamping face of the clamping jaw 22.
The pawl 26 pivots, under the effect of the spring 19, automatically into the phantom-line position shown in FIG. 4 when the feed jaws 11 and 12 move back into their position 11' and 12'. When, on the other hand, the workpiece 25 is advanced, the pawl 26 is pivoted out of the way by the feed jaw 12 into the solid-line position as shown in solid lines in FIG. 4.
It is to be noted that the spring 29 is illustrated in FIG. 4 essentially in a symbolic manner. In practice, underneath the pawl 26 a torque-exerting spring or the like is arranged in order to maintain the required structural space at a minimum as it may be better observed in FIG. 3.
It is further to be understood that the disclosed pawl 26 is only a simple although expedient example for supporting the workpiece 25. This function could be achieved by a backup support operated by a separate power cylinder assembly similarly to the clamping jaw 22. Such a backup support would be moved, prior to the beginning of the cutting operation and subsequent to the return stroke of the feed jaws 11 and 12 into the positions 11' and 12', against the workpiece 25 and would then be withdrawn prior to the consecutive feed effected by the feed jaws 11 and 12.
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.
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A method and apparatus for periodically feeding a rod-like workpiece into a severing machine for severing predetermined lengths in a cutting plane during cutting steps alternating with feeding steps. There are provided openable and closable clamping jaws for grasping the workpiece adjacent the cutting plane during each cutting step and openable and closable feed jaws for grasping the workpiece at a predetermined distance upstream of the cutting plane as viewed in the direction of feed and advancing the workpiece through the cutting plane by a distance corresponding to the desired length to be cut. The feed jaws are, subsequent to the feeding step and the closing of the clamping jaws, but prior to the completion of the cutting step, opened and moved away from the cutting plane by an extent that corresponds to the subsequent feed stroke and are thereafter closed again to grasp the workpiece anew.
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TECHNICAL FIELD
The present invention relates to a solution of N-[o-(p-pivaloyloxybenzenesulfonylamino)benzoyl]glycine monosodium salt tetra-hydrate of formula (I)
comprising a specific pH adjuster, and a drug product using the solution.
BACKGROUND ART
As to the compound used in the present invention, a free compound thereof, i.e. N-[o-(p-pivaloyloxybenzene-sulfonylamino)benzoyl]glycine of formula (II)
is described in example 2 (63) of JP kokai hei 3-20253 (i.e. EP 0 347 168) and a monosodium salt tetra-hydrate thereof, i.e. the compound of formula (I) is described in example 3 of JP kokai hei 5-194366 (i.e. EP 0 539 223) and reference example of JP kokai hei 9-40692 (no EP publication).
The compound (I) has an inhibitory activity against elastase and is a very useful compound which is expected to be used for the treatment of acute pulmonary disorders etc. Since those patients suffering from acute pulmonary disorders are in a serious condition, it is necessary to administer a drug parenterally, preferably as an injection for a long time (from 24 hours to several days) continuously. Therefore the compound (I) is preferably formulated as an injection or a solid composition to be dissolved before administration, more preferably formulated as a freeze-dried drug product.
However, the solubility of the compound (I) in water is less than 0.4 mg/mL and its solubility in ethanol is less than 6 mg/mL, and so it was hard to prepare a clear solution thereof for injection using normal solvents.
On the other hand, JP kokai hei 9-40692 discloses a method for the preparation of the compound (I) by suspending a compound of formula (II) to a mixture of water and ethanol, adding sodium hydroxide thereto and heating and then cooling. This operation shows a method for the preparation of a sodium salt tetra-hydrate from a free carboxylic form of formula (II) but does not intend to improve the solubility of sodium salt tetra-hydrate of formula (I).
DISCLOSURE OF INVENTION
The object of the present invention consists in improving the solubility of the compound (I), and thereby providing a solution thereof and some kinds of drug products using the solution, moreover providing a solution of higher concentration and a high-dosage drug product using the solution.
Considering the effective dose of the compound (I) and the volume of suitable closed containers (vials, ampoules, etc.), the required solubility of the compound (I) is estimated to be more than 15 mg/mL.
As a result of energetic investigations in order to improve the solubility of the compound (I), surprisingly, the present inventors have found that the purpose was accomplished by adding at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide to the solution.
As a result of another investigation to obtain a solution of higher concentration of the compound (I), the object is accomplished by using a kind of organic solvent except water in addition to using pH adjusters.
That is, the present invention relates to a solution of N-[o-(p-pivaloyloxybenzenesulfonylamino)benzoyl]glycine monosodium salt tetra-hydrate of formula (I)
comprising at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide and a drug product using the solution.
More particularly, the present invention relates to a solution of N-[o-(p-pivaloyloxybenzenesulfonylamino)-benzoyl]glycine monosodium salt tetra-hydrate of formula (I) comprising at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide in which the solvent is exclusively water, a solution wherein the solvent is a mixture of water and an organic solvent or a novel drug product using the solution optionally comprising excipients.
Besides, the present invention includes a novel freeze-dried drug product comprising the compound (I) and at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide.
As the present inventors first considered that the solubility of the compound (I) was greatly subject to the pH of the solution, the relationship between the solubility and pH was investigated.
On the other hand, since the compound (I) has an ester bond in its structure and it was assumed to be unstable in a basic aqueous solution, the present inventors investigated the influence of pH on the stability of the compound (I) at the same time.
(1) The Measurement of Solubility and Stability
Aqueous solutions of di-sodium hydrogen phosphate and tri-sodium phosphate were mixed in various ratios to prepare buffers of various pH. To the prepared buffers was added sodium chloride in order to fix the ionic strength of the buffers to be 0.2. At 25 degrees Centigrade condition, to each buffer was added the compound (I), and then according to the method of solubility test of Japan pharmacopoeia, a saturated solution was prepared by stirring for 30 seconds every 5 minutes for 30 minutes. Each solution was centrifuged and the supernatant was filtrated. The concentration of the filtrate was calculated by liquid chromatography and was defined as the solubility (mg/mL) and the measured value was defined as the initial value of the stability test. The results of measurement of the solubility are shown in FIG. 1 (open circles in the figure).
After each filtrate was incubated at 25 degrees Centigrade for eight hours, the residual rates, or amount of residue as a percentage, of the compound (I) were measured by liquid chromatography. The residual rate after eight hours was defined as the parameter for judging the stability. The results are shown in FIG. 1 (triangles in the figure).
FIG. 1 shows that the higher the pH is, the better the solubility of the compound (I) is, while it shows that the higher the pH is, the more decomposed the compound is. Therefore in order to use the compound (I) as a pharmaceutical product, it is necessary to keep it in the optimal range of pH in terms of solubility and stability.
That is, in terms of solubility, the solution should remain clear without eduction of the compound (I); on the other hand in terms of stability, the residual rate must be more than 98% that is acceptable for pharmaceuticals. It proved that the optimal range of pH for the condition was between 7.0 and 8.5 from FIG. 1 .
On the other hand, the specification of JP kokai hei 5-194366 discloses a drug product given by admixing N-[o-(p-pivaloyloxybenzenesulfonylamino)benzoyl]glycine monosodium salt tetra-hydrate (10 g), distilled water (500 mL), sodium chloride (7 g) and sodium carbonate (anhydrous) (1.5 g), filled 5 mL portion into each vial and freeze-dried by a conventional method.
However, it proved that the pH of the freeze-dried product manufactured according to the formulation example was ascended in the time course and gave a large amount of a decomposition product. The results are shown below.
(2) The Change of pH in the Time Course on Freeze-dried Product of the Compound (I) Comprising Sodium Carbonate
The pH was measured on aqueous solutions prepared by admixing each component in the ratios described in the above specification of JP kokai hei 5-194366 at the following three points.
(a) when the aqueous solution was prepared,
(b) when the prepared aqueous solution was filled in each vial (5 mL), freeze-dried and then dissolved in water (10 mL),
(c) when the prepared aqueous solution was filled in each vial (5 mL), freeze-dried and the formulation obtained was left at 60 degrees Centigrade for two weeks and dissolved in water (10 mL).
The result was that the pH was (a) 7.80, (b) 8.11 and (c) 8.44.
When the freeze-dried product was left at 60 degrees Centigrade for two weeks, the residual rate of the compound (I) was 91.4%.
These results show that addition of sodium carbonate in the formulation ascends the pH in the time course and long-term storage accelerates the decomposition of the compound (I) though the pH was in the range between 7.0 and 8.5, which we assumed optimal.
Sodium bicarbonate and potassium carbonate in place of sodium carbonate also ascended the pH in the time course and accelerated the decomposition.
As shown above, even if an aqueous solution of the compound (I) has an adequate solubility manufactured by adjusting to the optimal pH ranges, it is harmful if the drug product thereof is decomposed by ascending pH during storage.
Therefore the present inventors have energetically made efforts to find a pH adjuster which was capable of adjusting to the optimal pH range which gave more than a standard solubility and keeping the pH almost equal to the pH after the aqueous solution was prepared during the storage of the drug product thereof.
(3) The Investigation of pH Adjusters
The present inventors have investigated the amounts of di-sodium hydrogen phosphate, tri-sodium phosphate, potassium hydroxide and sodium hydroxide to add and the changes in pH thereby.
(i) Di-sodium Hydrogen Phosphate
Mannitol (8 g) was dissolved in water (50 mL) and thereto was suspended the compound (I) (4 g). Di-sodium hydrogen phosphate dodecahydrate (80 g) was added to water (200 mL) and dissolved by heating. To the above suspension under stirring with a stirrer was added the aqueous solution of Di-sodium hydrogen phosphate dodecahydrate by 5 mL each and the pH was measured. The results are shown in table 1.
The suspension of the compound (I) did not turn into a clear aqueous solution even when the pH was adjusted to 8.18 by adding the aqueous solution of di-sodium hydrogen phosphate dodecahydrate (200 mL), i.e. 80 g of di-sodium hydrogen phosphate dodecahydrate.
(ii) Tri-sodium Phosphate
Mannitol (8 g) was dissolved in water (140 mL) and to the solution was suspended the compound (I) (4 g). To the suspension under stirring with a stirrer was added an aqueous solution of tri-sodium dodecahydrate (4 g/100 mL) by 5 mL portion each and the pH was measured. The results are shown in table 1.
The suspension turned into a clear aqueous solution when 45 mL of the aqueous solution of tri-sodium phosphate dodecahydrate was added, and the pH of the solution was 7.19.
(iii) Potassium Hydroxide
Mannitol (8 g) was dissolved in water (180 mL) and to the mixture was suspended the compound (I) (4 g). To the suspension under stirring with a stirrer was added 1N aqueous solution of potassium hydroxide (0.5 mL portion each) and the pH of the solution was measured. The results are shown in table 2.
The suspension turned into a clear aqueous solution when 5 mL of the aqueous solution of potassium hydroxide was added, and the pH of the solution was 7.20.
(iv) Sodium Hydroxide
The compound (I) (7.5 g) was suspended to water (400 mL). To the suspension under stirring with a stirrer was added 1N aqueous solution of sodium hydroxide (1 mL portion each) and the pH was measured. The results are shown in table 2.
The suspension turned into a clear aqueous solution when 7 mL of the aqueous solution of sodium hydroxide was added, and the pH was 7.44.
TABLE 1
pH
Amount
(i) di-sodium hydrogen
(ii) tri-sodium
(mL)
phosphate
phosphate
0
6.83
6.10
5
7.28
6.22
10
7.46
6.30
15
7.60
6.45
20
7.68
6.57
25
7.75
6.66
30
7.81
6.73
35
7.85
6.79
40
7.89
6.91
45
7.92
7.19
50
7.94
7.57
55
7.97
7.93
60
7.99
8.34
65
8.01
8.95
70
8.03
10.10
80
8.06
—
90
7.93
—
100
7.94
—
150
8.06
—
200
8.18
—
TABLE 2
Amount
pH
(mL)
(i) potassium hydroxide
(ii) sodium hydroxide
0
6.34
6.94
0.5
6.32
—
1.0
6.36
7.06
1.5
6.39
—
2.0
6.53
7.14
2.5
6.64
—
3.0
6.76
7.18
3.5
6.86
—
4.0
6.97
7.22
4.5
7.08
—
5.0
7.20
7.26
5.5
7.36
—
6.0
7.65
7.32
6.5
8.06
—
7.0
8.45
7.44
7.5
9.42
—
8.0
—
7.59
9.0
—
7.78
10
—
7.97
11
—
8.21
12
—
8.55
13
—
9.27
From the results above, di-sodium hydrogen phosphate could provide optimal pH, but could not give a clear solution though a large amount was added. Therefore it was judged that di-sodium hydrogen phosphate was not a suitable pH adjuster which could accomplish the purpose of the present invention.
On the other hand, for the preparation of a solution, by using tri-sodium phosphate dodecahydrate, potassium hydroxide and sodium hydroxide, optimal pH were obtained immediately and a clear solution having more than a standard solubility could be manufactured.
The following experiments (4) to (9) were performed, regarding the three pH adjusters which could accomplish the object by the above experiment.
(4) Stability of the Drug Products
Mannitol (8 g) was dissolved in water (150 mL) and thereto was suspended the compound (I) (4 g). To the suspension was added one pH adjuster selected from the following (i)˜(iii), and finally the solution was filled up to 200 mL in total by water to obtain a clear solution.
(i) an aqueous solution of tri-sodium phosphate dodecahydrate (36.4 mg/mL; 50 mL),
(ii) an aqueous solution of potassium hydroxide (56 mg/mL 6 mL),
(iii) an aqueous solution of sodium hydroxide (40 mg/mL; 5.6 mL)
The pH of the prepared clear aqueous solutions was measured at the following three points.
(a) when the aqueous solutions were prepared,
(b) when the prepared aqueous solutions were filled in each vial (5 mL), freeze-dried and then dissolved in water (10 mL),
(c) when the prepared aqueous solution was filled in each vial (5 mL), freeze-dried and the drug product was left at 60 degrees Centigrade for two weeks (in case of sodium hydroxide for one month) and dissolved in water (10 mL).
The results are shown in table 3.
TABLE 3
(a)
(b)
(c)
(i) tri-sodium phosphate
7.75
7.75
7.73
(ii) potassium hydroxide
7.81
7.86
7.86
(iii) sodium hydroxide
7.90
7.92
7.90
Furthermore, when the freeze-dried product manufactured by adding sodium hydroxide was left at 60 degrees Centigrade for 1 month, the residual rate of the compound (I) was 98.3%.
From the results shown above, the drug products of the compound (I) comprising tri-sodium phosphate, potassium hydroxide or sodium hydroxide proved to be excellent in that the pH of the aqueous solution of the compound (I) could be fixed without ascending the pH in the time course and the compound (I) was stable during storage for a certain period.
Next the same investigation was performed on amino acid compounds, tris(hydroxymethyl)aminomethane and meglumine which were used for the same purpose as pH adjusters.
(5) Investigation of Compounds which can be Replaced with pH Adjusters
When KYORYOKU MORIAMINE infusion (Brand Name; manufactured by Morishita Roussel) as an amino acid compound was admixed with the compound (I) (5 mg/mL), great change of pH was not found (pH 6.36 after preparation and pH 6.13 after twenty-four hours), but the decomposition of the compound (I) was accelerated and the residual rate of the compound (I) after twenty-four hours was 54.1%. From these results it was judged that amino acid compounds were not suitable for admixing with the compound (I).
On the other hand, tris(hydroxymethyl)aminomethane lowered the stability of freeze-dried product; meglumine had the problem of lowering the stability during storage and discoloration.
From the results above, it was confirmed that in order to maintain a good solubility and stability not only just after preparation of the solution but also for a long term after manufacturing the drug product, not all pH adjusters which could adjust to suitable pH ranges might do, but exclusively tri-sodium phosphate, a hydrate thereof, sodium hydroxide and potassium hydroxide could accomplish the purpose.
Moreover, the present inventors aimed to manufacture a solution of higher concentration of the compound (I) than the above solution whose solubility was around 20 mg/mL, and a higher-dosage drug product using it.
(6) Investigation of a Solution of High Concentration
(i) To water (3 mL) were added the compound (I) (400 mg) and mannitol (100 mg). To the mixture under stirring, was added IN aqueous solution of sodium hydroxide (0.6 mL: corresponds to 24 mg). Thereto was added water in order to fill up to 5 mL of total amount. However, the mixture did not turn into a clear solution but a white suspension. Therefore it was impossible to freeze-dry the suspension.
Hereby it was found that the improvement of solubility using specific pH adjusters was limited, and so the present inventors next paid attention to the kinds of solvent.
(ii) To a mixture of ethanol (1.0 mL) and water (total approximately 3 mL) was suspended the compound (I) (400 mg) and mannitol (100 mg) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (0.6 mL; corresponds to 24 mg) little by little. Thereto was added water in order to fill up to 5 mL of total amount, to give a clear solution.
As shown above, in addition to using pH adjusters, use of a mixture of water and an organic solvent served to improve the solubility of the compound (I) to a great degree, thereby to manufacture a solution of higher concentration.
On the other hand, in order to formulate the solution of the present invention to an injection, particularly to a freeze-dried product, the amount of organic solvent is limited in the formulation process. That is to say, the capacity of normally used freeze-drying machine to cool is up to around −50 degrees Centigrade. Around −50 degrees Centigrade the ratio of organic solvent to the total amount is over 40%, when the mixture is subject to freeze-drying, it is in danger of bumping. Therefore, the amount of an organic solvent to add must be limited less than around 40% of the total solution.
Considering the above fact, optimal amount of the organic solvent was investigated.
(7) The Investigation of the Amount of the Organic Solvent
To a mixture of ethanol (the amount shown in the following table) and water (total approximately 3 mL) were suspended the compound (I) (400 mg) and mannitol (100 mg), and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (0.6 mL; corresponds to 24 mg) little by little. To the mixture was added water in order to fill up to 5 mL of total solution. The measured results of the conditions of the solutions manufactured according to the present prescription and the pH are shown in table 4.
TABLE 4
Ethanol (mL)
Results
pH
0.00
The solute remained
—
0.05
Clear solution
7.04
0.25
Clear solution
8.08
0.50
Clear solution
8.13
0.75
Clear solution
8.18
1.00
Clear solution
8.22
1.50
Clear solution
8.36
2.00
Clear solution
8.49
Hereby the present inventors succeeded in obtaining a solution of very high concentration by using ethanol for 1˜40 v/v % of total solvent amount in the presence of a certain amount of sodium hydroxide.
On the other hand, the amount of pH adjusters and its stability of the compound (I) were examined.
(8) To a mixture of ethanol (1.25 mL) and water (total approximately 3 mL) was suspended the compound (I) (400 mg) and mannitol (100 mg) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (the amount shown in the following table) little by little. To the mixture added water in order to fill up to 5 mL of total solution. The conditions of the solution prepared according to the present prescription, pH and the measured results of the residual ratio of the compound (I) by liquid chromatography after leaving at 25 degrees Centigrade for 8 hours are shown in table 5.
TABLE 5
sodium
Residual
hydroxide
Rate
(mg)
Results
pH
(%)
15
Solute remained
—
—
16
Clear solution
7.86
—
18
Clear solution
7.96
—
20
Clear solution
8.12
99.7
22
Clear solution
8.20
—
24
Clear solution
8.32
99.2
25
Clear solution
8.26
—
26
Clear solution
8.49
98.9
27
Clear solution
8.52
98.7
28
Clear solution
8.75
98.5
From the results shown above, it was possible to give an optimal pH by using pH adjusters in the presence of a certain amount of an organic solvent as well as the solution of the pound (I) comprising exclusively water as a solvent.
Even though the pH was over 8.5, the residual rate of the compound (I) was kept over 98%, aside from the solution of the pound (I) comprising exclusively water as a solvent.
As shown above, it is entirely surprising that the solubility of the compound (I) is improved to a great degree and the stability is also improved even in high pH ranges, by using an organic solvent; i.e. a mixture of water and an organic solvent in addition to pH adjusters and the fact was found out for the first time.
Hereby the stability of the freeze-dried drug product using the solution of high concentration of the present invention was examined.
(9) (i) the clear solution using ethanol 1 mL in the above (7) and (ii) the clear solution using the sodium hydroxide 27 mg in the above (8) were sterilized by a conventional method, filled to vials, and freeze-dried by a conventional method to give vials each containing 400 mg of the compound (I). The solubility in the time course was measured. The results are shown in table 6.
TABLE 6
Solution (i)
Solution (ii)
Residual
Residual
Storage Condition
Rate
pH
Rate
pH
When the freeze-dried
99.5%
8.26
98.7%
8.26
product was
manufactured
60 degrees Centigrade,
99.5%
8.25
98.1%
8.25
1 month
As shown in table 6, it was found that the freeze-dried drug product manufactured according to the method of the present invention was stable enough even after one month.
The drug product manufactured by freeze-drying the high-concentration solution of the compound (I) according to the present invention is excellent in that good solubility and stability is assured not only just after the preparation but also after the passage of long time.
The same results are also expected in the case of potassium hydroxide and tri-sodium phosphate as well as in the case of sodium hydroxide.
DESCRIPTION OF THE INVENTION
To accomplish the purpose of the present invention, at least one selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide is used as a pH adjuster. Sodium hydroxide, tri-sodium phosphate or a hydrate thereof or a mixture thereof is preferable and sodium hydroxide is particularly preferable.
For the preparation of the solution comprising exclusively water as a solvent, when the pH adjuster is added, then the preferable pH range of the solution is between 7.0 and 8.5, more preferably between 7.55 and 8.10.
For the preparation of the solution comprising both water and an organic solvent as solvents, when the pH adjuster is added, then the preferable pH range of the solution is between 7.0 and 9.0. Since the pH varies depending upon the amount of organic solvents, the preferable amount of the pH adjuster to add is 4.0˜7.0 w/w % of the compound (I), more preferably 4.5˜6.0 w/w % in case of sodium hydroxide.
These are added as a solid or as an aqueous solution.
As organic solvents in order to give a solution of higher concentration, alcohol is preferable, ethanol, isopropanol and t-butanol are more preferable, and ethanol is particularly preferable.
The amount of the solvent is preferably 1˜40 v/v % of the total solution amount, more preferably 10˜40 v/v %, particularly preferably 20-35 v/v %.
The above determines the amount of solvent by volume, but it may be converted into weight by multiplying density (d). For example in using ethanol, when d is assumed 0.785 g/mL, 1 v/v % equals to 0.785 w/v %, 40 v/v % equals to 31.4 w/v %.
The compound (I) may be prepared according to known methods, for example, the method described in JP kokai hei 5-194366 or JP kokai hei 9-40692.
The present invention includes a freeze-dried drug product comprising the compound (I) and at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide.
Generally, during the manufacturing process of freeze-dried drug products, the drug substance must be kept in a clear solution. That is because suspension and emulsion do not give a stable concentration of the drug substance therein, and furthermore the nozzles of the filling equipment may be stuck up. The present invention gives a clear solution having improved solubility, so that freeze-dried drug products may be manufactured with ease.
The doses to be administered of the compound (I) are determined depending upon age, body weight, symptom, the desired therapeutic effect, the route of administration, and the duration of the treatment. In the human adult, the doses between 100 mg and 1500 mg per person are generally administered by continuous administration between 1 and 24 hours per day from vein. Of course the doses to be used depend upon various conditions. Therefore, there are cases in which doses lower than or greater than the ranges specified above may be used.
For the administration of the compound of the present invention, it may be used as an injection for parenteral administration. Injections for parenteral administration include solutions, solid compositions to be dissolved before administration, e.g. freeze-dried products.
To the drug product of the present invention are optionally added excipients. Preferable excipients include lactose, glucose, maltose, mannitol, xylitol, solbitol, sodium chloride, etc. but in terms of freeze-dried cake, mannitol is more preferably used.
The drug products of the present invention may further include, stabilizing agents, pain-reducing agents, buffering agents and preserving agents, etc.
The drug products of the present invention are sterilized in the final process or prepared by aseptic operation. The freeze-dried products may be dissolved in sterilized distilled water or other solvents (e.g. physiological saline) for injection before use.
Effect of the Invention
The present invention provides a solution comprising water as a solvent having more solubility than a standard by improving the solubility of an insoluble drug compound (I) by adding at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide, and therewith providing some kinds of drug products using the solution. Moreover the present invention provides a solution of higher concentration by using a mixture of water and an organic solvent as a solvent and a high-dosage drug product using the solution.
Furthermore, the present invention provides a high-concentration solution by using the mixture of water and an organic solvent, and high-dosage products using the solution.
The drug product manufactured by freeze-drying the solution of the compound (I) assures good solubility and stability not only just after preparation but also after long-term storage.
In conventional processes, a relatively large vial was required for manufacturing a high-dosage unit. If the high-concentrated solution prepared by improving the solubility of compound (I) with respect to the solvent, for example, is freeze dried, a high-dosage unit in a smaller vial can be manufactured. As a result, the solution does not require the relatively large vials to provide high dosages, thus reducing cost.
When the compound (I) is administered to a patient of acute pulmonary disorders, for example by intravenous drips, the high-dosage drug product of the present invention alleviates the burden of those engaged in medical care (for example, preparing liquids for injection every several hours before administration, treating plural vials at the same time, etc.). Furthermore, good solubility of the drug product manufactured by the present invention in water enables them to treat the drug product with ease.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph which shows the relationship between pH and the solubility and stability of the compound (I). Circles show the solubility and triangles show the residual rate.
BEST MODE FOR CARRYING OUT THE INVENTION
The following examples illustrate the present invention, but it is not limited to the examples.
EXAMPLE 1(a)
Mannitol (20 g) was dissolved in distilled water, and to the mixture was added the compound (I) (10 g). To the mixture under stirring by a stirrer was added sodium hydroxide (0.44 g) and thereto was added a distilled water to fill up to 500 mL to give a clear aqueous solution of pH 7.65.
EXAMPLE 1(b)
The aqueous solution prepared in example 1(a) was sterilized by a conventional method, filled in vials (5 mL portion each), freeze-dried by a conventional method to give 100 vials each containing 100 mg of the compound (I).
EXAMPLE 2(a)
To the mixture of ethanol (50 mL) and water (total approximately 120 mL) were added the compound (I) (16 g) and mannitol (14 g) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (20 mL; corresponds to 800 mg) little by little. To the mixture was added water in order to fill up to 200 mL of total amount to give a clear solution of pH 8.05.
EXAMPLE 2(b)
The aqueous solution prepared in example 2(a) was sterilized by a conventional method, filled in vials (5 mL portion each) and freeze-dried by a conventional method to give 40 vials of freeze-dried drug products each containing 400 mg of the compound (I).
EXAMPLE 3(a)
To the mixture of ethanol (66 mL) and water (total approximately 120 mL) was added the compound (I) (20 g) and mannitol (10 g), and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (25 mL; corresponds to 1 g) little by little. Thereto was added water in order to fill up to 220 mL in total to give a clear solution of pH 8.09.
EXAMPLE 3(b)
The aqueous solution was sterilized by a conventional method, filled in vials (each 4.4 mL portion) and freeze-dried by a conventional method to give 50 vials each containing 400 mg of the compound (I).
EXAMPLE 4(a)
To a mixture of ethanol (50 mL) and water (total approximately 120 mL) were suspended the compound (I) (14.6 g) and mannitol (14 g) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (18 mL; corresponds to 720 mg) little by little. To the mixture was added water in order to fill up to 200 mL of total amount to give a clear aqueous solution of pH 8.04.
EXAMPLE 4(b)
The aqueous solution prepared in example 4(a) was sterilized by a conventional method, filled in vials (5 mL portion each) and freeze-dried by a conventional method to give 40 vials of freeze-dried drug products each containing 366 mg of the compound (I) per each vial.
EXAMPLE 5(a)
To a mixture of ethanol (60 mL) and water (total approximately 120 mL) were suspended the compound (I) (14.6 g) and mannitol (14 g) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (18 mL; corresponds to 720 mg) little by little. To the mixture was added water in order to fill up to 200 mL of total amount, to give a clear solution of pH 8.08.
EXAMPLE 5(b)
The aqueous solution prepared in example 5(a) was sterilized by a conventional method and filled in vials (5 mL portion each), freeze-dried by a conventional method to give 40 vials of freeze-dried drug products each containing 366 mg of the compound (I).
EXAMPLE 6(a)
To the mixture of ethanol (66 mL) and water (total approximately 120 mL) were added the compound (I) (18.3 g) and mannitol (10 g) and to the mixture under stirring was added 1N aqueous solution of sodium hydroxide (22. 5 mL; corresponds to 900 mg) little by little. Thereto was added water in order to fill up to 220 mL of the total solution to give a clear solution of pH 8.08.
EXAMPLE 6(b)
The solution prepared in example 6(a) was sterilized by a conventional method, filled to vials (4.4 mL portion each), freeze-dried by a conventional method to give 50 vials of freeze-dried drug products each containing 366 mg of the compound (I).
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A solution of N-[o-(p-pivaloyloxybenzenesulfonylamino)benzoyl]glycine monosodium salt tetra-hydrate (I) comprising at least one pH adjuster selected from tri-sodium phosphate, a hydrate thereof, sodium hydroxide or potassium hydroxide and a drug product using the solution. According to the invention, the solubility of the compound (I) increases and thereby it is possible to provide a solution thereof and a drug product using it. Moreover, by using a mixture of water and an organic solvent, greatly improved solubility makes it possible to manufacture a solution of higher concentration of the compound (I), and high-dosage drug products using it.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to the design and implementation of state machine engines in data processing systems.
[0002] A finite state machine (FSM) is a model of behaviour composed of states, transitions and actions. A state stores information about the past, i.e., it reflects the input changes from the start to the present moment. A transition indicates a state change and is described by a condition that would need to be fulfilled to enable the transition. An action is a description of an activity that is to be performed at a given moment. A specific input action is executed when certain input conditions are fulfilled at a given present state. For example, an FSM can provide a specific output (e.g., a string of binary characters) as an input action.
[0003] An FSM can be represented using a set of (state) transition rules that describes a state transition function. State transition diagrams are used to graphically represent FSMs. Classic forms of state transition diagrams are directed graphs, where each edge is a transition between two states and each vertex is a state. The inputs are signified on each edge.
[0004] Controllers in a broad spectrum of devices and systems are often based on state machine engines that implement a FSM. Emerging trends, including programmable accelerators etc., require the operation of these devices, and consequently also the controller operation, to be configurable and/or programmable. For this purpose, programmable state machine engines are used.
[0005] An example of such a programmable accelerator is the ZuXA accelerator concept described in a paper co-authored by one the inventors: Jan van Lunteren et al, “XML Accelerator Engine”, Proc. of First International Workshop on High Performance XML Processing, 2004. ZuXA is based on the BaRT-based FSM (B-FSM) technology. BaRT (Balanced Routing-Table Search) is a specific hash table lookup algorithm described in a paper of one of the inventors: Jan van Lunteren, “Searching Very Large Routing Tables in Wide Embedded Memory”, Proc. of GLOBECOM '01, pp. 1615-1619.
[0006] A ZuXA controller can be used to improve the processing of XML (extensible Markup Language) code. It is fully programmable and provides high performance in combination with low storage requirements and fast incremental updates. Especially, it offers a processing model optimized for conditional execution in combination with dedicated instructions for character and string-processing functions. The B-FSM technology describes a state transition function using a small number of state transition rules, which involve match and wildcard operators for the current state and input symbol values, and a next-state value. The transition rules are assigned priorities to resolve situations in which multiple transition rules are matching simultaneously.
[0007] FIG. 1 shows a block diagram of a subsystem of a controller comprising a state machine engine that implements a B-FSM (an FSM based on the BaRT hash table lookup operation). The transition rules are stored in a transition rule memory 10 . A rule selector 11 reads rules from the rule memory 10 based on a given input vector and a current state stored in a state register 12 . The transition rules stored in the rule memory 10 are encoded in the transition rule vector format shown in FIG. 2 . A transition rule vector comprises a test part 20 and a result part 21 . The test part 20 comprises fields for a current state 22 , an input character 23 and a condition 24 . The result part 21 comprises fields for a mask 25 , a next state 26 , an output 27 , and a table address 28 .
[0008] In a ZuXA controller the input to the rule selector 11 consists of a result vector provided by a component called instruction handler, in combination with a general-purpose input value obtained, for example, from an input port. In each cycle, the rule selector 11 will select the highest-priority transition rule that matches the current state stored in the state register 12 and the input vector. The result part 21 of the transition rule vector selected from the transition rule memory 10 will then be used to update the state register 12 and to generate an output value. The output value includes instructions that are dispatched for execution by the instruction handler component. The execution results are provided back to the rule selector 11 and used to select subsequent instructions to be executed by the instruction handler as described above.
[0009] FIG. 3 shows a more detailed block diagram of the state machine engine of FIG. 1 . The transition rule memory 10 contains a transition rule table 13 that is implemented as a hash table. Each hash table entry of the transition rule table 13 comprises several transition rules that are mapped to the hash index of this hash table entry. The transition rules are ordered by decreasing priority within a hash table entry. An address generator 14 extracts a hash index from bit positions within the state stored in the state register 12 and input vectors that are selected by a mask stored in a mask register 15 . In order to obtain an address for the memory location containing the selected hash table entry in the transition rule memory 10 , this index value will be added to the start address of the transition rule table in this memory. This start address is stored in a table address register 16 .
[0010] The function of the rule selector 11 is based on the BaRT algorithm, which is a scheme for exact-, prefix- and ternary-match searches. The BaRT search operation involves comparing the N=4 transition rule entries 30 , 31 , 32 , 33 contained in each hash table entry 0 and 1 in parallel with the search key. The search key is build from the actual values of the state register 12 and the input vector, while taking potential “don't care” conditions indicated by the condition field 24 of the transition rule entries into account. The first matching transition rule vector is then selected and its result part field 21 is selected to become the search result.
[0011] Especially, in a ZuXA controller the search result can be used to generate an instruction vector for the instruction handler that provides processing results back to the state machine engine as part of an input vector. The instructions contained in the instruction vector can be used for simple (and fast to be implemented) functions that run under tight control of the state machine engine. Examples are character- and string processing functions, encoding, conversion, searching, filtering, and general output generating functions.
[0012] Compared to other applications in which state machine engines are used, controllers embedded in larger systems often involve a much wider input vector to the state machine engine that is comprised of “status” and result information of a multitude of logic functions and components that are controlled by the state machine engine. For example, such embedded controllers are used in computer systems to perform parsing and pattern matching operations on a given stream of network data in order to offload these tasks from the central processors. The U.S. patent application 2004/0042487 A1 describes such a network traffic accelerator system and method.
[0013] For usual pattern-matching and parsing applications on the other hand, the input to the state machine engine often consists only of a single character in each clock cycle, a single byte in case of standard encodings such as ASCII (American Standard Code for Information Interchange). Support of wider input vectors as needed for a network traffic accelerator system, for example 32 bits, is much harder to implement in an efficient way at high processing rates, than to implement a state machine engine which processes input vectors consisting of only 8 bits, mainly because of the much larger set of possible input values that can occur. Due to the high clock frequencies of today's processors it is therefore a challenging task to provide a ZuXA controller implementation for the use as a network traffic accelerator in computer systems with such high speed processors.
[0014] In practice, however, often only a subset of the entire set of possible input values will be used, and consequently, the state machine engine design can be optimized for that given subset. One example is to use a hash function for selecting state transitions, which only considers certain groups of bits from the input value. Another example would be to assume that from most states (e.g., 95%), at most a certain number (e.g., 4) of transitions can be made, each labeled with a certain input value.
[0015] A similar approach related to logic synthesis methods is described in a technical disclosure published as IPCOM121980D. Logic synthesis is a process by which an abstract form of desired hardware logic circuit behaviour (typically at the so-called register transfer level or behavioural level) is turned into a circuit design implementation in terms of logic gates. Common examples of this process include synthesis of hardware description languages (e.g., VHDL or Verilog). In a logic synthesis tools chain, an FSM compiler is used to process a state transition table (or other specified input formats) and derives a sum-of-products equation for each output and for each bit of the storages (e.g., latches) used to represent the state of an FSM.
[0016] Since it is not possible for a simple FSM compiler alone to determine if a particular FSM contains sub-paths of a timing critical path in the circuit design implementation, but this information is usually known to the logic designer, the logic designer can provide this information to the FSM compiler. The FSM compiler can then use this information to reorder the sum-of-products equations to reduce the delay of the critical sub-path based on the designer's “coaching”.
[0017] There exist several others of these examples corresponding to a variety of different techniques that can be used to implement a state machine engine. In all cases the subset of the possible input values is specified by certain constraints for the set of possible input values. It is therefore beneficial to optimize the state machine engine implementation for that given subset of possible input values, enabling an efficient and fast implementation, rather than trying to cover all possible input values, resulting in an expensive and slow implementation. However a problem exists wherein some of the input values, or combinations of input values, are not supported by the state machine engine implementation.
SUMMARY OF THE INVENTION
[0018] In particular embodiments of the present invention a method for the implementation of state machine engines, a corresponding computer program and computer program product are described.
[0019] The advantages of the present invention are achieved by a method of checking a state transition function specification created by a designer, and resolving any constraint conflicts in an interactive way. FIG. 4 shows a block diagram of an illustrative data flow in which a constraints checker and conflict resolution tool implementing a method in accordance to the present invention is executed before the actual implementation of the state transition function is performed by an existing state transition function implementation tool.
[0020] The input to the constraints checker and conflict resolution tool consists of a state transition function specification created by a designer, which can be described in various ways, but typically consists of a state transition table, listing all state transitions together with their originating and destination states, input and output values. An alternative description can consist for example of a list of state transition rules, involving wildcards and priorities.
[0021] The output of the constraints checker and conflict resolution tool consists of a similar state transition function specification, which meets all constraints that are imposed by the state transition function implementation tool. The latter tool will generate an implementation of the state transition function based on that specification. The actual operation of the implementation tool and corresponding constraints are dependent on the implementation technology.
[0022] For example, prior art methods for implementing non-programmable state machine engines typically use a register in combination with combinatorial logic that implements the associated state transition function. In this case, the implementation tool can generate a specification of the combinatorial logic that can be used by logic synthesis tools for the creation of a physical implementation of the state machine engine the implements the state transition function.
[0023] Prior art methods for implementing programmable state machine engines allow programming a state transition function by modifications of a RAM (Random Access Memory), for example, by storing the next states for each combination of a current state and input value in a large table, or alternatively, by applying a hash function as done in the ZuXA architecture, wherein the implementation tool will generate a data structure that is written into the RAM.
[0024] The constraints checker and conflict resolution tool implements the following three basic subsequent steps:
[0025] A constraints checking step implemented by a method that checks the state transition function that is created by a designer, against the constraints that are imposed by the implementation technology, and detects all portions of the state transition function that do not meet these constraints (conflicting constraints).
[0026] A conflict resolution step implemented by a method that tries to determine one or more suggested ways to meet the conflicting constraints by investigating how the original state transition function can be modified such that all constraints are met.
[0027] A presentation and selection step implemented by a method of presenting to the designer in a textual and/or graphical way both the results of the constraints check performed in the first step, in particular the portions of the state-transition diagram that do not meet the constraints, and the suggested modifications determined in the conflict resolution step. The designer can respond interactively by indicating that he accepts one of the suggested modifications, or can modify the state transition function manually. In the former case, the constraints check and conflict resolution is completed. In the latter case, the modified (portions of the) state transition function will be processed, starting again with the constraints checking step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention and its advantages are now described in conjunction with the accompanying drawings.
[0029] FIG. 1 : Is a block diagram of a subsystem of a B-FSM controller;
[0030] FIG. 2 : Is a block diagram of a transition rule vector format;
[0031] FIG. 3 : Is a block diagram of a subsystem of a B-FSM controller;
[0032] FIG. 4 : Is a block diagram illustrating a data flow in accordance with the present invention;
[0033] FIG. 5 : Is a state transition diagram;
[0034] FIG. 6 : Is a state transition diagram;
[0035] FIG. 7 : Is a state transition diagram derived from the state transition diagram of FIG. 5 in accordance with the present invention;
[0036] FIG. 8 : Is a state transition diagram derived from the state transition diagram of FIG. 6 in accordance with the present invention.
[0037] It is to be noted, however, that the appended drawings illustrate only example embodiments of the invention, and are therefore not considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0038] In a first preparing step, a designer of a state machine engine needs to specify the state transition function for the FSM implemented by the state machine engine. FIGS. 5 and 6 are examples for state transition diagrams. In both figures S k and S n represent states, i 1 to i 5 represent some given input vector, and 1000b to 0001b represent a set of input vectors in binary representation.
[0039] The state diagram in FIG. 5 illustrates the following list of state transitions:
S k i 1 →S k+1 S k i 2 →S k+2 S k i 3 →S k+3 S k i 4 →S k+4 S k i 5 →S k
[0045] Whereas the state diagram in FIG. 6 illustrates the following list of state transitions:
S n 1000b→S n+1 S n 1100b→S n+2 S n 1011b→S n+3 S n 0001b→S n+4
[0050] For the preferred embodiment of the present invention, the list of state transitions needs to be derived from a state transition function description provided by the designer. This preparing step can be performed using well-known methods. The list of state transitions will then be checked against certain types of constraints for the state transitions. This step is called the constraints checking step.
[0051] For the preferred embodiment of the invention at least two types of constraints for state transitions are supported. The first constraint type consists of an upper bound on the total number of state transitions that originate from the same state. The second constraint type involves limitations on the input vectors that are associated with the state transitions from the same state, in particular the bit positions in which these can be different. Additional constraint types are not excluded and can be handled in a similar way.
[0052] For the first type of constraint, an array of counters, one for each state, each of which represents the number of transitions corresponding to that state, is created. The initial value of each counter is zero. While processing the list of state transitions, the counter corresponding to the “current” state involved in each transition processed will be incremented. In case of a wildcard condition for the current state, all counters in the array will be incremented, as this state transition relates to all states. After incrementing a counter, it will be checked if the counter value is greater than the specified bound. If so, the corresponding state will be recorded as being in conflict with the constraint.
[0053] For example, if a constraint is specified that limits the number of state transitions to at most 4 transitions per state, it will be determined for the state diagram shown in FIG. 5 , that state S k has 5 transitions and consequently conflicts with this constraint.
[0054] For the second type of constraint, a set will be created for each state. These sets contain all input values that correspond to the state transitions of the particular state. Then the logical exclusive-or-product (XOR-product) for each combination of input values in that set is created, which reflects the bits in which the input values are different from each other. The actual constraint, i.e., the limitation on the bit positions in which the various input values are different from each other are then checked on the XOR products.
[0055] For example, for state S n shown in FIG. 6 the following set of input values that corresponds with the four transitions of state S n is created:
i) {1000b, 1100b, 1011b, 0001b}
[0057] The XOR-product is then determined for each combination of input values:
i) XOR-product 1: 1000b xor 1100b=0100b ii) XOR-product 2: 1000b xor 1011b=0011b iii) XOR-product 3: 1000b xor 0001b=1001b iv) XOR-product 4: 1100b xor 1011b=0111b v) XOR-product 5: 1100b xor 0001b=1101b vi) XOR-product 6: 1011b xor 0001b=1010b
[0064] The “1”/set-bits in the XOR-product indicate the bit positions at which the various input values are different from each other. All constraints of the second type can now be directly checked against the XOR-products.
[0065] For example, if the constraint would be that the input values should be different at a maximum of two bit positions, then this would mean that all XOR-products would include at most two set-bits. This is verified by counting the set-bits in each of the XOR-products. In the above example, it will be detected that XOR-products 4 and 5 are conflicting with this constraint, because these contain three set bits, meaning that the corresponding input values 1100b, 1011b, and 0001b are different from each other at more than two bit locations (as can be directly verified).
[0066] In a similar way, constraints can be checked that limit the bit positions in which the differences are allowed to occur, to specific locations within the input vectors. For example, a constraint could specify that bit differences are not allowed to occur at bit position 0 (which is the left-most bit in the above binary vectors). For this version of the constraint, each XOR-product is tested to have only set bits at the bit positions at which differences are allowed to occur. Any set bit at a different bit location will result in the identification of a conflict with the constraint. For example, for the constraint described above, XOR-products 3, 5 and 6 are conflicting, because these contain a set-bit at bit position 0 , indicating that the corresponding input vectors are different from each other at this given bit position.
[0067] The next step after the constraints checking step described above is called the conflict resolution step. In this step potential modifications of the state transition function are derived that would resolve the conflict situation and create a state transition function that meets all constraints. These potential modifications are then suggested to the designer. The derivation of potential modifications that resolves the conflicting constraints is performed separately for the two (or more) constraint types described above.
[0068] If the number of transitions for a single state exceeds a specified bound (the first constraint type), then this can be resolved potentially by creating an additional state and transferring all the “excess” number of transitions plus one, to that new state, while a new transition is created from the original state to the new state that will be used if none of the remaining transitions are taken (which are within the specified bound). If the number of transitions of the new state also exceeds the limit imposed by the constraint, the same procedure is iterated on the new state as well.
[0069] It is now explained using the state transition function of FIG. 5 . In this case, state S k has 5 transitions and consequently conflicts with the constraint that limits the number of transitions per state to a maximum of 4 transitions. Based on the above described conflict resolution step, this part of the state transition function can be modified to become the state transition function of the state transition diagram shown in FIG. 7 . In this state transition diagram a new state S k ′ has been inserted, to which the “excess” number plus one, which equals two transitions have been transferred. A transition will be made from the original conflicting state S k to the new state S k ′ if none of the transitions that remain “at” state S k are used. This “else”-transition is taken if the input value does not equal i 1 , i 2 , or i 5 as shown in FIG. 5 .
[0070] Such an “else”-transition is created using the B-FSM technology, by assigning it S k as current state, a wildcard as input value, S k ′ as next state, and a priority that is lower than the other transitions that originate in state S k . Furthermore, this “else” transition will not process an input value, but indicates using an instruction/output bit, that the input is put on hold, so that the current input value can be evaluated again for determining the transition to be taken from state S k ′. FIG. 7 shows one potential modification only. In this case, various modifications are possible, involving different transitions with input values to be transferred to the new state (e.g., the transitions with input values i 1 and i 2 or any other combination).
[0071] The second constraint type relates to the bit positions in which the input values are allowed to be different from each other. In case a conflict has been detected, then a potential modification of the state transition function can be suggested, that transfers one or multiple transitions to a new state, similar as described above for resolving conflicts for the first constraint type. However, in this case, a minimum number of state transitions will be selected for transfer to the new state, in order to meet the constraint. The latter is done by the following steps:
[0072] Step 1: A new state is created.
[0073] Step 2: In the list of XOR-products for a given state that conflicts with a constraint of this type, it is determined which transition and associated input value occur most frequently in the “problematic” XOR-products.
[0074] Step 3: This transition and input value is transferred to the new state.
[0075] Step 4: The list of XOR-products is recalculated, and any conflicts are determined.
[0076] Step 5: If there are no conflicts left, then go to step 6. If there are conflicts left then go to step 2.
[0077] Step 6: Create the “else” transition from the original conflicting state to the new state.
[0078] Applying this method on the above discussed example for the constraints checking step related to FIG. 6 , involving the constraint that the input values should only be different at a maximum of two bit positions, would result in input value 1100b being identified as the input value that most frequently occurs in the problematic XOR-products, namely XOR-products 4 and 5. The corresponding state transition is transferred to a new state as shown in FIG. 8 . In this case, the “else” transition is created using a wildcard for the input value, which consequently does not conflict with the other transitions from state S n , and also has a lower priority.
[0079] The new state and “transferred” transitions are also checked against all constraints, and if a conflict is found, the above described procedures are repeated to identify potential modifications of the state transition function that resolves the conflict.
[0080] The final presentation step involves the presentation to the designer of the conflicting constraints that were identified in the first step, as well as the suggested modifications of the state transition function that were identified in the conflict resolution step.
[0081] The presentation can consist of a textual listing of the state number or identifier plus the corresponding list of state transitions, together with an error number indicating the conflicting constraint. It can also include a graphical representation of a corresponding state transition diagram or a portion of it, high-lighting the conflicting states and state transitions.
[0082] The suggested modifications can be presented in a similar way: textual or graphical. The designer can then indicate by responding to a question, such as “Do you accept the proposed modification?” or the like. If the designer responds, e.g., by pushing a button labeled “YES” on a computer screen to indicate an accepting answer, the modification is accepted; otherwise the designer is provided with the option to make the modifications manually. In case of multiple conflicting constraints, the designer has to respond for each conflict found. If multiple modifications are suggested, then these will be labeled with a number, and the designer can select which of the suggested modifications he accepts or reject all of them.
[0083] The invention can also be used without a presentation and selection step. In that case the automatically determined modifications to the state transition function are accepted without any interactions. The modified state transition function is represented as a list of state transitions. Such a list can be transformed in a description of the modified state transition function suitable as an input to existing tools using well-known methods.
[0084] Especially, the invention can be used in conjunction with a ZuXA controller. The state transition function for the FSM is then specified by the designer as a set of transition rules. A constraints checker and conflict resolution tool executed on a computer system implements a method in accordance with the present invention, the method comprising the constraints checking step, the conflict resolution step, and the presentation step. The input to this tool is a set of transition rules which are modified using this tool to another set of transition rules. This set of transition rules is then processed by a transition rule compiler that serves as a transition function implementation tool.
[0085] The B-FSM algorithm can distribute the state transition rules in various ways over the hash table entries, and consequently, over the cache lines (upon which these hash table entries are mapped), by extracting the hash index from various bit positions (which is achieved by using various index masks) and by using various state encodings. The function that generates the data structure, which includes performing this mapping, is called the transition rule compiler.
[0086] The transition rule compiler creates data structures that can be loaded to a transition rule memory. The designer selects the modifications to the state transition function presented by the constraints checker and conflict resolution tool on an input mask presented by the computer system.
[0087] The invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In an embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
[0088] Furthermore, the invention 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 instruction execution system. For the purposes of this description, a computer-usable or computer-readable medium can be any 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.
[0089] A computer processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution.
[0090] While a particular embodiment has been shown and described, various modifications of the present invention will be apparent to those skilled in the art.
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The invention relates to a method and system for the design and implementation of state machine engines. A first constraints checking step checks a state transition function created by a designer against constraints imposed by the implementation technology in order to detect all portions of the state transition function that are in conflict with the constraints. A subsequent conflict resolution step tries to determine one or more suggested ways to meet the conflicting constraints, by investigating how the original state transition function can be modified such that all constraints are met. A final presentation and selection step provides the designer textual and/or graphically results of the constraints check and suggested modifications. The modifications can be accepted interactively, or the state transition function can be changed manually. In the latter case, the modified state transition function will be processed starting again with the constraints checking step.
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RELATED PATENT APPLICATIONS & INCORPORATION BY REFERENCE
[0001] This utility application is a continuation application of U.S. application Ser. No. 11/973,843, entitled “TREATING CARIOGENIC DISEASED ORAL BIOFILM WITH ELEVATED pH OR pH BUFFERING ORAL HEALTH CARE PRODUCTS,” filed Oct. 10, 2007, which claims priority of U.S. provisional application 60/852,167, filed Oct. 16, 2006. This related applications are incorporated herein by reference and made a part of this application. Moreover, any and all U.S. patents, U.S. patent applications, and other documents, hard copy or electronic, cited or referred to in this application are incorporated herein by reference and made a part of this application.
1. FIELD OF THE INVENTION
[0002] The present invention relates to treating a dental patient's oral health, such as cavities, as symptoms of a biofilm disease. The invention describes and claims treatment of the disease with high-pH or pH buffering health care products.
2. BACKGROUND AND RELATED ART
[0003] Oral health problems such as cavities result from a biofilm disease. In the past dentists generally only treated the symptoms, i.e. filling cavities, and not the cause of the symptoms, so patients continued to get cavities.
[0004] Others have tried to solve this problem in the past with antimicrobial agents including rinses, toothpastes, gels, gums, and other oral health care products that are acidic in pH. The problem is that the diseased biofilm in the mouth contains >96% acidogenic and aciduric bacteria. These bacteria are unique in their ability to maintain intra-cellular neutrality in an acidic biofilm because they have an H+ion pump mechanism that allows them to continuously pump the acidic ions out of their cells and into the biofilm.
[0005] The pH of the biofilm in the mouth is acidic and results in the chemical dissolution of the calcium salts from tooth enamel which ultimately results in a cavity. The healthy and desirable oral bacteria cannot survive in an acidic environment, so treating the biofilm with an acidic product, drives the pH of the biofilm lower. Lower pH is moving in the wrong direction for the proper pH in maintaining dental health.
[0006] Applicants have discovered that three things that are effective against a bacterial oral biofilm are 1) heat, 2) mechanical debridement, and 3) a strong oxidizing agent. The present invention provides antimicrobial and remineralization oral health care products with a pH that is alkaline (higher pH) rather than acidic (lower pH) and also contains pH buffering agents. These higher pH agents drive the pH of the biofilm to the correct, higher level for healthy bacteria to reform in the oral biofilm and prevent cavities. The oral care antimicrobial/remineralization products of this invention have a pH that ranges between 8.0-11.5. The oral health care products of this invention include rinses, oral sprays, toothpastes, gels, varnishes, creams, gums, mints, floss, toothpicks, swabs, brushes, sponges, and dissolving strips.
[0007] Earlier antimicrobial/remineralization products such as described in U.S. Pat. No. 4,367,218 were either remineralization products that contain fluoride or calcium salts, which usually are of an acidic pH. Antimicrobial products are also mostly all acidic in pH. Another category of product had an elevated pH include a rinse based on sodium bicarbonate and aluminum salts, with a pH up to 9.4. This rinse was not an antimicrobial or remineralization product.
[0008] Additional work by others has been done on controlling the level of bacteria in the mouth. In U.S. Pat. No. 7,060,726 Hiramoto et al described using a mixture of coumarin analogues obtained from citrus fruit products. Leusch et al, in U.S. Pat. No. 6,238,648 disclose oral care compositions that combine a non-cariogenic carbohydrate and polyalcohol. Kramer et al., in U.S. Pat. No. 6,290,934 disclose agents for the promotion of oral health comprising ionically bound or free thiocyanate ions and carbamide perhydrate in combination with known additives and vehicles.
[0009] Other patents of interest to applicants include Lee et al in U.S. Pat. Nos. 6,214,321 and 6,120,754. The Lee works deal with the remineralization of teeth. Both patents teach first and second compositions, the first composition having a pH less than 7 and the second composition having a pH greater than 7. When combined upon application to teeth, the first and second compositions generate hydroxyapatite depositing same on dental enamel. Lee's elevated pH is quite different from applicants' invention wherein higher pH is desired in and of itself to raise the pH of dental biofilm.
[0010] High pH is mentioned in U.S. Pat. No. 6,872,565 by Mollstam et al. Mollstam is concerned with reducing the number of Streptococcus mutans in the mouth through inhibiting activity in combination with good binding to the oral mucins and dental plaque. A high pH material is used in at least one example.
[0011] A bioengineered bacterial organism to over express two or more Lactococcus lactis HtrA to promote the inhibition or removal of a biofilm is presented by Wang et al in US Patent Publication 2007/0059295. Applicants have no such organism.
[0012] In U.S. Pat. No. 5,603,920 Rice discloses a dentifrice composition wherein the pH is above 9. In his invention, Rice does not mention the oral biofilm at all.
SUMMARY OF THE INVENTION
[0013] The present invention provides antimicrobial and remineralization oral health care products with higher, alkaline pH and pH buffers. These products drive the pH of the biofilm to the correct level for the healthy bacteria to reform in the biofilm and prevent cavities. Among the oral health care products are rinses, oral sprays, toothpastes, gels, varnishes, creams, gums, mints, floss, toothpicks, swabs, brushes, sponges, and dissolving strips and the like. Methods of using these products are also described and claimed herein.
DEFINITIONS USED IN THIS INVENTION
[0014] In this invention, ‘acidogenic’ bacteria will mean acid-forming bacteria. In this invention, ‘aciduric’ will mean relating to bacteria that tolerate an acid environment.
[0015] In this invention, low pH will mean pH values that are lower than 7.
[0016] In this invention, high pH will mean pH values that are higher than 7.
[0017] In this invention, biofilm is a complex aggregation of microorganisms marked by the excretion of a protective and adhesive matrix. A typical biofilm of this invention is the dental plaque that forms on teeth that causes tooth decay and is a bacterial biofilm.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Applicants have developed oral care products including several oral rinses that are pending in a current U.S. patent application Ser. No. 11/337,435 filed on Jan. 23, 2005 and entitled “System for Caries Management by Risk Assessment”. The rinses described therein are antimicrobial/remineralization with pH values of about 8.0 and 11.50. The pH values ranging between 10 and 11.5 are about as strong as patients can tolerate without the burning of the oral soft tissue.
[0019] For the purposes of the present patent application, a plurality of the available oral care products on the market was tested for pH. As seen in Table 1, it was discovered that they were virtually all acidic in pH; some with a pH as low as 4.04.
[0020] Dental caries is now defined by the dental profession as a biofilm disease, with the caries causing bacteria taking control of the biofilm on the teeth. When the oral environment favors these bacteria, the biofilm population shifts from the normal healthy flora to the acidogenic and aciduric bacteria associated with dental caries. As more is learned about controlling the oral biofilm, the three things listed supra are known to be effective against biofilms in general. Because of the structure and function of biofilms, they are only susceptible to complete debridement, heat, and strong oxidizing agents. In the mouth, it is nearly impossible to completely debride the cariogenic biofilm away. The biofilm reforms within hours after it is removed and bacteria are ubiquitous in the mouth. Heat is not a good option, as heat that is applied to the oral structures at a high enough temperature to destroy the bacteria, would also destroy the host tissues. Strong oxidizing agents offer some potential as antimicrobial agents in safe- to -use concentrations.
[0021] ATP bioluminescence has been used for over 40 years to rapidly identify the bacterial load of an environment. ATP is the energy molecule used by all living cells, and if it is present in water or on a surface, the ATP present is indicative of the bacterial load. When the ATP sample is mixed with stabilized luciferin/luciferinase, it emits light and can be measured in a light sensitive meter. ATP bioluminescence is a non-specific test, as specific bacterial species cannot be identified. In the mouth, there is also an unknown amount of human somatic ATP levels, depending upon the recent activity of the mouth.
[0022] There is a strong direct correlation between the ATP bioluminescence level of the oral biofilm in a mouth at rest, and the number of Cariogenic bacteria present. During three separate randomized clinical trials, it was determined that there was a strong direct correlation between the Caries Susceptibility Test score and the number of colony forming units (CFUs) of Mutans streptococci , a known cariogenic bacteria strain. The graph of twenty-five patients and their pre and post treatment CariScreen Scores is shown in FIG. 1 .
[0023] As seen from the big difference in the heights of the bars for each patient, treatment with a product of this invention greatly reduced the RLU (relative light units, labeled “Cariscreen®”)) scores for patients after treatment. As noted above, the amount of Mutans streptococci in these patients is greatly reduced.
[0024] Fluoride reduces the acid solubility of enamel, and reduces the pH demineralization threshold from 5.5 to 4.5. It also affects the metabolism of cariogenic bacteria. Fluoride has been applied systemically in water supplies and by prescription tablets, and topically with fluoride toothpaste, fluoride rinses, gels and foams. It is also applied directly to the teeth in varnishes. Other attempts at antimicrobial therapy have focused mainly around the use of chlorhexidine in either a rinse or a varnish. While chlorhexidine is effective against Mutans streptococci , it has no effect against Lactobacilli and the effect on other cariogenic bacteria is not known. Xylitol is known to disrupt the metabolism of Mutans streptococci and other cariogenic bacteria. These bacteria readily ingest the xylitol, but are unable to digest it and must expend additional energy to expel it from the cell.
[0025] Xylitol has been used in rinses, toothpastes and gels, mints, gum and assorted other products. With lack of an effective antimicrobial product, some researchers and clinicians have even used Betadine®, 10% Povidone Iodine as a mouth rinse. The problem with Betadine, aside from the unpleasant taste, is the fact that it can only be used one time per month because the iodine/thyroid interaction. A significant number of people who are allergic to shellfish are also allergic to iodine.
[0026] The elevated pH and pH buffering capability of the products of the instant invention plays a major role in the reestablishment of a healthy, normal biofilm. The cariogenic biofilm is acidogenic and aciduric, and the pH of the biofilm is acidic, favoring these bacteria. One important consideration in treatment is to drive the pH of the biofilm up to basic levels, giving the healthy bacteria a better opportunity to reestablish a healthy, protective biofilm on the teeth.
[0027] The advantages of applicants' solution over previous solutions is that the currently described group of products are simple and effective antimicrobial remineralization oral health care products with an elevated pH and pH buffers that drives the pH of the oral biofilm above at least a value of 7.0. This serves to greatly reduce and/or eliminate the acidogenic/aciduric bacteria that cause dental caries. It also favors the healthy bacteria that protect the teeth in a healthy biofilm with elevated pH values.
[0028] The prior art of U.S. Pat. No. 4,367,218 requires the metallic carbonate/bicarbonate salts of their product rinses to be shaken and then rinsed in the mouth every 30 minutes throughout the day. The products of the present invention do not require shaking, and they only need to be used one or two times per day on the same schedule that a patient uses normal oral care products such as mouthwash, floss, toothpaste and the like.
[0029] Applicants' solution would not be obvious to other inventors in the dental field because dentistry has been focused on producing acidic products and have not done experiments with highly elevated pH products to determine treatment outcomes. The present invention runs contrary to the beliefs and procedures for current dental health and products supporting dental well-being. Applicants' solution to dental health problems is not intuitive and it is not obvious, as it is contrary to long-held tenets of dentistry.
EXAMPLES
[0030] Applicants have developed oral rinses that are antimicrobial and that help remineralization of the teeth with pH values ranging from 8.0 to 11.5, as well as pH buffering agents. The instant patent application encompasses many oral health care products such as toothpastes, gels, oral sprays, gum, mints, varnishes, floss, toothpicks, swabs, brushes, sponges, and dissolving strips.
[0031] Applicants have tested a large sampling of the available oral care products currently on the market for pH value which are shown in Table 1, below. The products were tested using a Beckman® 240 pH meter with a measurable pH range of 0-16 and FUTURA™ Gel-Filled Epoxy pH Electrode. After calibration with Chem Products color coded pH buffers, 3 separate pH readings were taken for each product and the average of the 3 readings was taken as final pH value. Virtually all of them tested acidic in pH. In fact, one product had a pH values as low as 4.04
[0000]
TABLE 1
Rinse Name
Tested pH
CariFree Treatment Rinse
10.38
CariFree Maintenance Rinse
8.00
Cepacol
7.53
Act
6.36
NeutraFlor 220
6.03
NeutraFlor 900
5.98
Colgate Fluorigard
5.98
Rembrandt Whitening
5.73
Listerine Whitening
5.60
Peridex
5.50
Scope
5.45
BreathRx
4.77
Oral-B Anticavity Rinse
4.73
Biotene Mouthwash
4.67
Oral-B Antibacterial Rinse
4.65
Listerine
4.45
BreathRx Antibacterial Mouth Spray
4.35
FluoroCare 200
4.31
Crest Pro-Health
4.24
Tom's of Maine Natural Mouthwash
4.04
[0032] The products of this invention are effective antimicrobial and remineralization oral health care products with an elevated pH and pH buffers. The elevated pH and ph buffers drive the pH of a patient's biofilm to an elevated level that will eliminate the acidogenic and aciduric bacteria that cause dental caries, and favors the healthy bacteria that protect the teeth in a healthy biofilm.
[0033] The following FIGURE, FIG. 1 shows the significant effect of the use of various products of this invention in terms of reduction of RLU post treatment with said products.
[0034] The FIGURE shows the large difference between the heights of the bars for 25 patients. It shows a significant decrease and improvement in RLU scores for each patient who has successfully completed a treatment with one product of the instant invention. There is a strong direct correlation between the ATP bioluminescence level of the oral biofilm in a mouth at rest, and the number of Cariogenic bacteria present. During three separate randomized clinical trials, it was determined that there was a strong direct correlation between the Caries Susceptibility Test score and the colony forming units (CFUs) of Mutans streptococci , a known cariogenic bacteria strain.
Product Summary
[0035] The products of this invention are designed to provide antimicrobial and remineralization oral health of a dental patient. As has been discussed, the products have a pH that is alkaline ranging from values of about 8.0 to about 11.5, as well as pH buffers. The alkalinity and buffers drive the pH of the biofilm in a patient's mouth to a level which encourages the growth of healthy bacteria that reforms the biofilm and improves the health of the patient's mouth. The instant invention comprises oral health care products selected from the group consisting of rinses including a maintenance rinse, a two-component treatment rinse, oral sprays, toothpastes, gels, varnishes, creams, chewing gums, mints, floss, toothpicks, swabs, brushes, sponges, and dissolving strips.
[0036] The rinses of this invention include both a maintenance rinse and a two part therapeutic rinse. The maintenance rinse comprises about 73 weight percent water, about 25 percent xylitol, about 1 weight percent sodium benzoate, about 1 percent potassium sorbate, 0.05 percent sodium fluoride, 0.2 percent citrus or mint flavor, 0.2 percent polysorbate 20, sodium bicarbonate, calcium hydroxide, or sodium hydroxide to boost and buffer pH to above 8.0, and trace amounts of 90% polyphenol and cranberry extract.
[0037] The therapeutic rinse of this invention is a two-part rinse that is utilized for two weeks and then is followed by a maintenance rinse. The treatment rinse contains fluoride as an active ingredient, along with a strong oxidizing agent selected from the group consisting of sodium hypochlorite, calcium hypochlorite, potassium hypochlorite, magnesium hypochlorite, and sodium hydroxide to buffer the treatment rinse to an elevated pH of 10.38-11.50. A single dose of this two part rinse is mixed each time it is used.
[0038] The two part treatment rinse includes the first part of the treatment rinse that comprises water in the amount of about 73 weight percent, xylitol in the amount of 22 weight percent, sodium benzoate in the amount of 2.0 weight percent, sodium fluoride in the amount of 0.05 weight percent, mint oil in the amount of 1.0 weight percent, poloxamer in the amount of 1.25 weigh percent, menthol in the amount of 1.0 weight percent, and the second part comprises water in the amount of about 92 weight percent, sodium hydroxide in a quantity to bring the pH of the second component to 11.9, and 5% sodium hypochlorite solution in the amount of 8 percent to bring the total sodium hypochlorite concentration to 0.4 percent.
[0039] The patient swishes the rinse in his mouth for a minute and then expectorates. After two weeks of the treatment rinse, the patient is then placed on daily use of the maintenance rinse. This single part rinse contains fluoride as the active ingredient, xylitol, an elevated pH of at least 8.0, a ph buffer, and the known naturally occurring antimicrobials polyphenol and anthocyanidins.
[0040] In addition to the antimicrobial basis for the rinses, they also have remineralization properties with the fluoride, and the elevated pH and pH buffers play a major role in the re-establishment of a healthy, normal biofilm. The cariogenic biofilm is acidogenic and aciduric, and the pH of the biofilm is acidic, favoring these bacteria. One important consideration in treatment is to drive the pH of the biofilm to basic levels, giving the healthy bacteria a better opportunity to reestablish a healthy, protective biofilm on the teeth. One concern about anti-caries rinses and products should be their pH. It does not make sense to treat and acidic biofilm with an acidic product, if the desired bacteria require an environment with neutral or basic pH.
[0041] Another product of this invention is an oral spray. The spray product allows patents to maintain the alkaline pH of their biofilm quickly and easily. Propylene glycol, polyethylene glycol, hydrogenated castor oil, aloe vera, sunflower oil, avocado oil, glycerin or flax seed oil can be optionally added in quantities less than 10% to increase oral moisturization.
[0042] Another product of this invention is a fluoride-free maintenance rinse. The fluoride-free maintenance rinse comprises about 72 weight percent water, about 15 weight percent xylitol, about 10 weight percent of one or more components selected from the group consisting of polyethylene glycol, hydrogenated castor oil, aloe vera, sunflower oil, avocado oil, glycerin and flax seed oil, about 0.2 weight percent sodium benzoate, about 1.8 weight percent potassium sorbate, traces of natural color and natural flavor and sodium hydroxide in an amount that buffers the pH of the rinse to a value between 8 and 10.
[0043] Another product of this invention is an oral gel that comprises water in the amount of about 68 weight percent, xylitol in the amount of 25 weight percent, hydroxyethyl cellulose in the amount of 1.65 weight percent, sodium benzoate in the amount of 0.1 weight percent, potassium sorbate in the amount of 1 weight percent, propylene glycol, glycerin, or polyethylene glycol in the amount of 10 weight percent, hydrogenated starch hydrolysate in the amount of 2 weight percent, sodium laurel sulfate in the amount of 1.2 weight percent, flavor in the amount of 1.1 weight percent, polysorbate 20 in the amount of 2 weight percent, calcium acetate in the amount of 0.01 weight percent, and sodium bicarbonate in the amount sufficient to buffer the composition to a pH value of at least 8. Sodium Fluoride may also be added to this product in the amount of 0.05-1.1 weight percent.
[0044] Another gel that is part of this invention is an oral gel comprising an aqueous solution of sorbitol 70% in the amount of 42 weight percent, distilled water in the amount of 20 weight percent, calcium carbonate in the amount of 10 weight percent, sodium bicarbonate in the amount of 5 weight percent, sodium laurel sulfate in the amount of 2 weight percent, titanium dioxide in the amount of 1 weight percent, precipitated silica in the form of Zeodent® 113 in the amount of 5 weight percent, guar gum in the amount of 0.5 weight percent, carboxy methylcellulose in the amount of 0.5 weight percent, sodium saccharin in the amount of 0.5 weight percent, xylitol in the amount of 5.0 weight percent, collagen in the amount of 2.0 weight percent, sodium benzoate in the amount of 0.3 weight percent, precipitated silica in the form of zeodent 165 in the amount of 5.0 weight percent, sparkle glitter in the amount of 1.2 weight percent, and trace amounts of flavor to taste, and sodium bicarbonate in an amount sufficient bring and buffer the composition to a pH value of at least 8.
[0045] The Zeodent® products are precipitated silicas with low surface area and enhanced flavor compatibility. Discussed in U.S. Pat. No. 6,946,119 to Gallis et al, Zeodent® products are used in some dentifrices for their antimicrobial activity.
[0046] This invention also comprises a group of products designed for protecting the oral health of babies, infants, and children. These products include antimicrobial and remineralization oral health care products with a pH that is alkaline for the protection of the oral cavity of youngsters comprising suckers and other hard candies, popsicles, rinses, gel, wipes, varnishes and swabs.
[0047] More specifically, the product is an antimicrobial wipes which are pre-moistened with a solution comprising fluoride and xylitol, and a pH value of about 8. Furthermore, the solution for said wipe comprises 63 weight percent water, 10 weight percent glycerin, 25 weight percent xylitol, 2 percent sodium benzoate, flavor, and sufficient sodium bicarbonate to bring and buffer the pH of the wipe to a value of at least 8.
[0048] The solution is pre-applied to a small (preferably 5″×3″, although the size may vary) non-woven cotton fabric as a pre-moistened wipe for application and cleansing of a child's oral cavity, teeth, tongue, and gums. The wipe is used twice daily, especially after mealtimes.
[0049] The oral health product contains propylene glycol, polyethylene glycol, hydrogenated castor oil, aloe vera, sunflower oil, avocado oil, glycerin or flax seed oil can be optionally added in quantities less than 10% to increase oral moisturization.
[0050] Being able to document successful treatment outcomes provides validation for both the patient and his/her dental team that the medical model of caries diagnosis and treatment is effective. The products of this invention provide patients and the dental team with confidence that the bacterial infection can and is being controlled. With annual screenings, potential problems can be identified and addressed before serious restorative intervention is required.
[0051] The methods of this invention include a method for providing oral antimicrobial treatment and remineralization of the teeth of a patient comprising the steps of diagnosing and treating dental caries from a medical model comprising the steps of
a) analyzing the biofilm in a patient's mouth; b) measuring the bacterial load in the mouth using ATP as an indication of the patient's oral bacterial load; c) correlating the ATP bioluminescence level of the oral biofilm in a mouth at rest and the number of CFU's of cariogenic bacteria present in the mouth; d) prescribing a regimen of products that are effective against a bacterial biofilm selected from the group consisting of heat, mechanical debridement and a strong oxidizing agent; e) providing antimicrobial and remineralization oral health care products with a pH that is alkaline ranging from about 8 to about 11.5 and pH buffers to maintain these pH levels for the maintenance and reformation of healthy bacteria in the biofilm; f) monitoring the patient until the biofilm is maintained in a healthy state.
[0058] In this manner, the oral health care products are selected from the group consisting of rinses including a maintenance rinse, a two-component treatment rinse, oral sprays, toothpastes, gels, varnishes, creams, chewing gums, mints, and floss.
[0059] The oral care antimicrobial/remineralization products of this invention have a pH in the range between about 8.0 and 11.5 as well as pH buffers to maintain these pH levels.
[0060] More specifically, a maintenance rinse of this invention comprises about 73 weight percent water, about 25 percent xylitol, about 1 weight percent sodium benzoate, about 1 percent potassium sorbate, 0.05 percent sodium fluoride, 0.2 percent flavor, 0.2 percent polysorbate 20, sodium bicarbonate or sodium hydroxide to boost pH to above 8.0, and trace amounts of 90% polyphenol and cranberry extract.
[0061] Furthermore, the therapeutic rinse is a two-part rinse that is utilized for two weeks wherein a single dose of the two part rinse is mixed each time it is used. The two-part treatment rinse is used for two weeks by the patient by swishing the rinse in his/her mouth for a minute and expectorating. The first part of the treatment rinse that comprises water in the amount of about 73 weight percent, xylitol in the amount of 22 weight percent, sodium benzoate in the amount of 2.0 weight percent, sodium fluoride in the amount of 0.05 weight percent, mint oil in the amount of 1.0 weight percent, poloxamer in the amount of 1.25 weight percent, menthol in the amount of 1.0 weight percent, and the second part comprises water in the amount of about 92 weight percent, sodium hydroxide in a quantity to buffer the pH of the second component to 11.9, and 5% sodium hypochlorite solution in the amount of 8 percent to bring the total sodium hypochlorite concentration to 0.4 percent.
[0062] After two weeks of the treatment rinse, the patient is then placed on daily use of the maintenance rinse. The rinses, along with the other products of this invention, assure that elevated pH plays a major role in the re-establishment of a healthy, normal biofilm in the patient's mouth.
Scope of the Invention
[0000]
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A method of treating biofilm disease using a pH adjusted therapeutic rinse that comprises two parts that are separated and in amounts that upon mixing provide a single dose. The two parts together and then rinsing a patient's mouth with the single dose and expectorating.
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CLAIM OF PRIORITY
This application is being filed as a non-provisional patent application under 35 U.S.C. §111(b) and 37 CFR §1.53(c). This application claims priority under 35 U.S.C. §111(e) to U.S. provisional patent application Ser. No. 61/675,873, filed Jul. 26, 2012, entitled “Feeding Nipple Container” the contents of which are incorporated herein by reference
FIELD OF THE INVENTION
The invention relates an infant feeding container nipple. In particular, the present invention is directed to storing, mixing and dispensing a predetermined dose of a composition.
The predetermined dose of the composition may be a powder or liquid. For example, the powder or liquid may be a nutritional infant or adult formula powder form.
BACKGROUND OF THE INVENTION
Traditionally, when an adult travels with an infant from their home, it is essential to pack and carry numerous bulky and cumbersome baby products. In particular, it is necessary to pack various items to anticipate the infant's meal, such as, sterile baby bottles, one or more sterile water-filled bottles and various containers of a baby formula powder, a measurement scooper, a bib and baby wipes. The burden of having to carry all of these items to feed the infant when they are hungry (which includes mixing a measured amount of water with a predetermined amount of baby formula powder, using a scoop to put the powder inside the nursing bottle when the user needed to feed the infant), makes traveling anywhere outside of the home discouragingly complicated and an unsatisfying experience.
When baby formula is mixed with water, the recommended time for consumption is within about an hour. Thereafter, it was recommended that the remainder of the formula beverage be discarded to prevent the introduction of bacteria and/or other harmful germs to an infant. (See http://www.ehow.com/how — 2514_prepare-ready-mix.html).
In an attempt to extend the use of formula by keeping the ingredients separated until use, various bottle designs have been proposed which have been unsuccessful in providing a simple bottle design that stores, mixes and easily dispenses the beverage.
For example, U.S. Pat. No. 4,264,007 illustrates a top mounted container to hold a small quantity of a second material at the opening of a bottle. This design brings extra and unnecessary parts and requires to be removed from the main container to allow the resulting mixed liquid from being dispensed.
For example, U.S. Pat. No. 5,419,445 illustrates a very complicated baby bottle including an extra cartridge assembly, requiring some extra skills to put all the parts together and definitely increasing the complication related to feeding a baby in a daily regular basis which is repeated up to twelve times per day; as well of other drawbacks related to the use of this design.
U.S. Pat. No. 5,634,714 illustrates a primary container with a removable stemmed plug, which introduces a very high risk of injury for a baby and the possibility of an obstruction while two ingredients are mixing and/or dispensing; as well of other drawbacks found on this design.
U.S. Pat. Nos. 5,692,644, 5,794,802, 5,863,126, and 6,257,428, illustrate other examples of a very complicated devices requiring many extra parts, requiring extra care and capabilities for assembly and disassembly and in some cases representing an injury risk if these devices are used to feed babies. All this and other drawbacks complicate the regular use of a baby bottle, in which a parent is required to load liquid and powdered formula, assemble the bottle, feed the baby and wash these devices up to twelve times every single day.
For at least these reasons, the above devices fail to solve the problem of efficiently storing, mixing and dispensing of a formula beverage.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a nipple container for a dispensing unit for storing, mixing and dispensing of a beverage.
The nipple container may include a vent system to allow air to enter to the nipple container as fluid is removed.
Another object of this invention is to provide a nursing bottle including the nipple container, that stores a predetermined amount of powder formula and a main container including a predetermined amount of water or liquid. In a stored position, a lid seals an open end of the nipple container in communication with the main container, and prevents the powder and liquid from mixing. The lid is released by applying an external deformational force on an exterior surface of the nipple feeding container and the powder and the liquid are allowed to mix.
A further object of this invention is to provide for an improved mixing process between powder and liquid through use of the releasable lid as an agitator.
This invention solves the longstanding need for providing a simple, ready to use, quick and portable sterile nursing dispenser.
These and other objects, features, and/or advantages may accrue from various aspects of embodiments of the present invention, as described in more detail below.
Although the invention is illustrated and described herein in the various exemplary embodiments provided, it is nevertheless not intended to be limited to only the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments of this invention will be described in detail, wherein like reference numerals refer to identical or similar components or steps, with reference to the following figures. Likewise, some of the figures herein depict minimal line-work for ease of understanding.
FIGS. 1 , 2 and 2 A illustrate exemplary side section and perspective views respectively of a dispensing nipple container including a dispensing nipple, a container lid and a lid tether in accordance with and embodiment of this invention.
FIG. 2B is a partial enlarged detail view of FIG. 1 which illustrates the features that releasably hold the container lid in a storage (or sealing) position against an inner cavity of the dispensing nipple.
FIGS. 3 and 4 illustrate exemplary side section views of a dispensing nipple container according to the present invention placed on a nursing bottle in a storage and an opened (or mixing) position respectively.
FIG. 5 illustrates an exemplary side section view of a dispensing nipple container according to the present invention placed on a nursing bottle in a storage position.
FIG. 6 illustrates an exemplary side section view of a dispensing nipple container according to the present invention placed on a nursing bottle at the moment of release.
FIG. 7 illustrates an exemplary side section view of a dispensing nipple container according to the present invention placed on a nursing bottle during mixing.
FIG. 8 illustrates an exemplary side section view of a dispensing nipple container according to the present invention placed on a nursing bottle during feeding.
FIGS. 9 and 10 illustrate exemplary side perspective and section views respectively of an embodiment of a dispensing nipple container according to the present invention including a separate container lid and an attaching tether.
DETAILED DESCRIPTION OF THE INVENTION
Particular embodiments of the present invention will now be described in greater detail with reference to the figures.
FIGS. 1 , 2 and 2 A illustrate side section and perspective views respectively of a feeding nipple container 100 . The feeding nipple container 100 is constructed to separate, store, mix and/or dispense a baby formula powder or any other type of ingredient. In more detail, the feeding nipple container 100 illustrates an open end 12 , an inner cavity 18 and a nipple tip 16 of a nipple body 10 , a lid tether 22 and a container lid 20 , all as part of an integral unitary piece.
In particular, FIG. 1 shows the feeding nipple container 100 in the storage position, in which the container lid 20 is secured to the open end 12 of the nipple body 10 . FIGS. 2 and 2A show the feeding nipple container 100 in the mixing or open position. The container lid 20 is integrated to the nipple body 10 by the lid tether 22 . In the storage position, the lid tether 22 is stretched so as to act as spring biased to urge the container lid 20 to open upon release of the lid locking features 60 , 62 (see FIG. 2B ). The lid tether 22 also keeps the container lid 20 open after the container lid 20 has been released from the open end 12 in the mixing position.
FIG. 2B illustrates in detail the features that keep the container lid 20 in sealing engagement with the open end 12 while in the storage position. As is shown, in the storage position, lid lip 60 , which is formed circumferentially around the container lid 20 , is prevented from disengaging from the open end 12 by a sealing lip 62 which is formed circumferentially around the open end 12 . A retaining flange 64 , also formed circumferentially around the container lid 20 , prevents the container lid 20 from being forced into the inner cavity 18 of the nipple body 10 upon closing.
Alternative embodiments of the present invention may completely eliminate lid lip 60 and sealing lip 62 . In such embodiments, container lid 20 may be kept in sealing engagement with open end 12 by designing the two components so that they engage using an interference fit. In such an arrangement, the circumference of container lid 20 may be slightly larger than the circumference of open end 12 creating a pressure fit between the two upon engagement. The difference in the circumferences of container lid 20 and open end 12 will depend on the type of materials used. In any event, the fit may be designed so that the pressure required to close and open container lid 20 is optimized for the intended use.
Upon application of a releasing force 50 on nipple body 10 (see FIGS. 4 and 6 ), the sealing lip 62 is deformed and the lid lip 60 is released. As the lid tether 22 pulls on the container lid 20 , the container lid 20 opens and releases any baby formula (or other ingredient) stored in the inner cavity 18 . If an interference fit is used to maintain sealing engagement between container lid 20 and open end 12 , the releasing force 50 will similarly deform open end 12 and simultaneously urge container lid 20 to open.
To hold the necessary amount of baby formula powder to prepare the regular amount of formula beverage for a baby, a cavity size of at least 2 cubic inches of capacity for the inner cavity 18 of the nipple body 10 is desirable. A larger or smaller cavity size may be used depending on the intended use of the device or the type of ingredients to be mixed
To allow the necessary deformation to release the container lid 20 from the open end 12 , a flexible and/or resilient material may be used to manufacture nipple body 10 and tether 22 . Desirable materials which are commonly used to make baby bottle nipples, such as rubber (latex) and silicone are acceptable for the disclosed invention, but the invention is by no means limited to such materials. Any material that has sufficient flexibility, resiliency and hardness to retain the proper shape to maintain engagement between the container lid 20 and open end 12 , is acceptable. With regard to hardness, materials having a durometer reading between 40 and 60 (using the “Shore A” scale) are known to be suitable to the present application. Again, however, this should not be considered a material limitation for the present invention.
FIGS. 3 and 4 show simple exemplary cross-section side views of the feeding nipple container 100 secured to a cup container 30 by a collar 40 .
In particular, FIG. 3 shows an exemplary embodiment of the feeding nipple container 100 in storage position, in which a venting valve 14 is integrated to the nipple body 10 to prevent a vacuum effect when the feeding nipple container 100 is in use.
FIG. 4 shows the feeding nipple container 100 in the mixing position, where the releasing force 50 is applied on the nipple body 10 , deforming the shape of the nipple body 10 and forcing the container lid 20 to be released from the open end 12 of the nipple body 10 .
FIGS. 5 , 6 7 and 8 show simple exemplary views of the feeding nipple container 100 in use and secured to the cup container 30 by a collar 40 .
In particular, FIG. 5 shows the feeding nipple container 100 in the storage position; in which a first substance is disposed in the inner cavity 18 the nipple body 10 ; and the container lid 20 is secured to the open end 12 of the nipple body 10 and preventing to mix the first material 52 from mixing with the second material 54 disposed inside the cup container 30 .
FIG. 6 shows the nipple container 100 in the mixing position, in which the releasing force 50 is deforming the shape of the nipple body 10 , forcing to release the container lid 20 from the open end 12 of the nipple body 10 , allowing the first substance 52 and the second substance 54 (as shown in FIG. 5 ) to mix into a composition 56 .
According to this exemplary embodiment, the nipple body 10 may hold a variety of different substances, including but not limited to: a powder or a liquid, such as: a powdered formula (e.g., an infant formula), and/or any other type of liquid or powdered beverage drink additive (such as tea, punch, sports hydration drink). Likewise, the cup container 30 may also be filled with variety of different substances intended to be mixed with the substance in the nipple body 10 to make a mixed composition, including but not limited to: water, milk and/or any other type of liquid or powder.
In use, as shown in FIG. 7 , the user may then speed up the mixing process by shaking the nipple container 100 secured to the cup container 30 by the collar 40 . Here it is shown that container lid 20 also may function as an agitator, helping to uniformly mix the first substance 52 and the second substance 54 into the composition 56 .
FIG. 8 shows an exemplary section view of the nipple container 100 , in which an unlocking feature of the lid tether 22 is shown. The lid tether 22 , may be made of a flexible and resilient material and shorter in length that the distance between the attaching point 28 (as shown in FIG. 1 ) between the nipple body 10 and the tether lid 22 , and the attaching point 26 between the container lid 20 and the tether lid 22 in the storage position. Accordingly, the lid tether 22 has to be stretched to allow the container lid 20 to be secured to the open end 12 of the nipple body 10 (as shown in FIGS. 1 , 3 and 5 ) in the storage position. In the storage position, therefore, lid tether 22 acts as a spring urging the container lid 20 to open once the releasing force 50 (as shown in FIGS. 4 and 6 ) is applied. In use and after the container lid 20 has been released from the open end 12 of the nipple body 10 by the releasing force 50 ; the tether lid 22 contracts again and prevents the container lid 20 of going back to its previous position at the open end 12 by gravity or shaking ( FIGS. 7 and 8 ), allowing a free flow of the first substance 52 , second substance 54 and/or the composition 56 from the nipple body 10 to the cup container 30 or vice versa.
In an alternative embodiment of the present invention, lid tether 22 need not act as a spring or urge the container lid 20 to open or remain disengaged from open end 12 . In such an embodiment, the sole purpose of lid tether 22 would be to maintain lid tether 22 attached to the nipple body 10 once it is disengaged from open end 12 . Maintaining such an attachment would provide convenience to the user and aid in the agitation function of the container lid 20 (see FIG. 7 ). In such an embodiment lid tether 22 need not be made of a resilient material and its length may be such that slack is provided when container lid 20 is engaged with open end 12 .
In yet another embodiment of the present invention, lid tether 22 can be completely eliminated, and container lid 20 can be a completely separate part from nipple body 10 . In such an embodiment, once container lid 20 is forced into disengaging from open end 12 , container lid 20 would simply fall into cup container 30 and could be recovered once the cup contents are emptied.
FIGS. 9 and 10 show perspective and section side views respectively of another exemplary embodiment of the nipple container 100 , in which the container lid 20 (as shown in FIGS. 1 , 2 and 2 A) and the nipple body 10 are separated and a modified tether lid 22 a having a connecting hole 24 b and a modified lid 20 a having a connecting pin 24 a are incorporated to the nipple container 100 . In use, the modified lid 20 a is attached to the nipple body 10 by inserting the connecting pin 24 a into the connecting hole 24 b of the modified tether 22 a.
Although various exemplary embodiments are shown above, it is to be understood that these examples should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the preferred embodiments of the invention. For example: All parts described can be made of different sizes and/or figures. Parts and/or sections of parts can be separated in different parts to create other parts. Parts and/or sections of parts can be replaced by other parts and/or sections of parts.
It will be recognized by those skilled in the art that changes or modifications may be made to the above described embodiment without departing from the broad inventive concepts of the invention. It is understood therefore that the invention is not limited to the particular embodiment which is described, but is intended to cover all modifications and changes within the scope and spirit of the invention.
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A container for storing and dispensing a substance including a deformable nipple having an open end, a feeding tip and a storage cavity; a lid adapted to releasably engage the open end of the nipple; and a (optionally) a tether having resilient properties, the tether connecting the nipple to the lid; wherein, in a storage position the substance, when placed within the storage cavity of the nipple, is contained; wherein in a mixing position, the substance is released from the storage cavity of the nipple; and wherein the container transitions from the storage position to the mixing position upon application of an external force to the nipple, causing the nipple to deform and the lid to disengage the open end of the nipple.
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RELATED APPLICATIONS
This application claims priority from Mexican application Serial No. MX/a/2009/013992 filed Dec. 17, 2009, which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
The present invention falls under the washer category, in particular that of top loading washers and even more specifically; it applies to washers which has a metal cabinet, from which four fastened suspension rods hang each having a lower extremity comprised of a shock absorber; these are inserted into an equal number of disposable ears in the tub intended specifically for this purpose which in turn support the tub and additionally act as a good suspension system for the vibrations which are generated during the washing, rinsing and centrifuge motions. The tub holds in its interior a perforated basket, which itself contains an agitator in concentric form: the shaft of said agitator is mechanically connected to an electric motor which is suspended in the lower portion of the tub.
BACKGROUND
The tub not only holds the weight of the water and the articles to be washed, but also supports the static and dynamic charges which are generated with the washing or centrifuge motions, some of which can be large enough to deform the shape of the tub, knowing that these are generally manufactured by thermoplastic injections, the most popular being polypropylene. So, for example, when the basket is turning at a high speed in order to achieve centrifuge it is very common that the weight of articles to be washed in the basket cause an imbalance of the system, which cause the basket to not only have a rotational movement but also a translational one within the tub, even causing possible scraping against the tub's internal wall, not a desired effect of the design. If this occurs in addition to the deformation caused in the tub's mouth, the gap between the basket and the tub is greatly reduced.
This is why it is necessary to design a tub for a top loading washer which is highly rigid, not discounting the difficulty of manufacture, using thermoplastics like polyethylene or polypropylene, which help absorb, distribute and transmit the different forces and efforts created by the varying washing and centrifuge cycles.
Various efforts in this area have taken place with said objectives in mind, such as Paul Gregory Hall's AU2006235808 patent application which deals with a pumping system which is fastened to the lower portion of the tub; FIG. 2 shows a cross section of the lower portion of the tub where the reinforcements of the inferior external part of the tub can be seen, where a pancake type motor is grasped emphasizing the pump's assembly, the part of particular interest in this tub being the use of lobes in the tub's superior part which are aligned with the reinforcement of the support ears.
Jonathan David Hartwood's et al EP 1 783 264 A2 published patent application which presumably shows in FIG. 2 , the same tub as Hall's, where there appear a pair of lobes aligned with the ear reinforcements, wherein said lobes were presumably designed to create more space for the basket inside the tub, given their number, as it only is comprised of two lobes which do not significantly increase the area's rigidity in the tub's mouth, allowing a larger space to the basket as well as to the tub's cover which can house a grid, window or passage in the precise additional area created by the lobes intended to transport chemicals deeper into the tub to be mixed with greater ease.
Even so, though the tubs shown in both documents at a simple glance appear to have strong reinforcements at the ears making them better able to hold heavy loads, no concern seems to be given to avoiding the deformation neither to the tub's mouth nor to the tub's cylindrical wall with an end result of attaining a more rigid tub which supports, absorbs, cushions and transmits the forces generated inside the basket while washing or centrifuge motions take place.
Given the above discussion, the need to develop a tub with higher rigidity yet using the traditional manufacturing materials, thereby reducing cost becomes apparent. The tub also allows for larger baskets to be held due to lesser deformities and thus transmits more efficiently the efforts to the suspension rods with shock absorbers, and also avoids the scraping between the tub and the basket during centrifuge, where larger baskets allow for larger washing loads as well as water and detergent (mixes water with chemicals or additives), allowing for larger washing loads in an equal volume sized cabinet, this being the purpose of this invention.
BRIEF DESCRIPTION OF THE INVENTION
Derived from the experience of designing and manufacturing washers it is noted that the tub, far from being solely an object which contains water and detergent, has structural functions as well. It supports the basket's assembly which is aligned with the tub in its symmetrical axis, as well as to the transmission or reduction box which can be fitted to the agitator; it also supports the electric motor, hoses, overflow ducts etc. This entire group afore mentioned plus the suspension rods are known as the sub-washer. The tub itself hangs from four suspension rods whose lower area has a shock absorber mechanism, whereas the higher section of said suspension rods are attached to the upper corners of the cabinet which statically and kinematically support the sub-washer. The lower area of the suspension rods are fastened to the tub by means of ears lodged in the shock absorbers, this system allows the tub at least three degrees of freedom, because if it were a rigid assembly, the washer would tend to “walk” or jump, not being capable of softening the vibrations emerging from its own operation, such as those being created from the agitation of the wash load itself or the centrifuge stages.
This is why the tub is comprised of a robust system of reinforced ears with veins which run along its length as well as the tub's circumference.
Another characteristic of the tub discussed in the present invention, are reinforcements running like a belt on the external periphery of the tub's cylindrical wall, which discourage possible deformations to said tub, and knowing that water's own weight exerts a force on said wall, coupled with certain washing conditions which require hot water for proper stain removal or to activate chemicals or detergents mixed in the wash, said temperatures can reach near 60° C., which can cause a considerable re-softening in the equatorial area of the tub's cylindrical wall inflating it to a balloon shape, not a desirable deformation because when this happens, the tub's mouth itself tends to deform inwardly reducing the gap or area between the basket and the tub, which in turn creates friction due to scraping between these two parts during the agitation and specially centrifuge motions which leads to wear out and possible permanent damage as a hole can be formed on the cylindrical wall where the repeated and prolonged scraping take place.
Another characteristic to be outlined, are the higher petal lobes located in the tub's mouth which allow the tub's mouth higher rigidity avoiding deformities to the tub's mouth caused by the basket's rotations, widening the gap between the tub and the basket precisely in the area where the basket's nodding occurs considerably avoiding the friction due to scraping between the tub and the basket. To help avoid deformities to the tub's circular wall between the lobes and over the reinforcement belt, reinforcements are placed in arc form. These reinforcements allow for the distribution of forces created by the dynamic and hydrostatic charges allowing for a better transmission of these to the shock absorbers of the suspension rods.
Yet another aspect of the present invention is found in the tub's bottom crafted as a truncated cone which allows drainage and guides the washing mixture unto the lower area, followed by an inclined plane which then guides the washing mixture towards a trough, where the valves or the pumps are fed.
On the opposite side of the tub's bottom, that is, the deep exterior, a reinforcement of a series of ribs is found which allow for extraordinary rigidity using minimum material. In this way, the elements herein described coupled with others to be detailed later, constitute the present invention creating a robust top loading washing machine with exceptional structural rigidity which allows for withstanding of high temperatures of washing mixtures without causing major deformities, high work effort, a reduced gap between the tub and the basket which allows for significant water conservation while being able to use a smaller volume tub, among other attributes.
BRIEF DESCRIPTION OF DRAWINGS
These and other characteristics, aspects and advantages of the present invention will be better understood upon reading the following detailed description referencing the accompanying drawings in which:
FIG. 1 is an isometric cross-section of a sub-washer.
FIG. 1 a is an isometric representation of the tub with suspension rods, a drainage duct and a spraying hose.
FIG. 2 is an isometric representation of the tub with suspension rods, an overflow duct, a spraying hose and an exploded drainage system.
FIG. 3 is an upper view of the tub.
FIG. 4 is a lateral cross view of the tub.
FIG. 5 is an inferior isometric view of the tub.
FIG. 6 is a detailed view of the lower part of the tub, specifically that of the ear.
FIG. 7 is a lateral view of the tub.
FIG. 8 is a detailed cross section of the tub's ear.
FIG. 9 is an upper isometric view of the tub.
FIG. 10 is a detailed cross-section of the overflow drain.
FIG. 11 is a detailed view of the assembly of the drainage duct unto the overflow drain.
FIG. 12 is a detailed isometric view of the tub's mouth.
DETAILED DESCRIPTION
The washing machine being described in the present invention, illustrated in FIG. 1 , is a top loading machine or vertical axis, and possesses a cabinet from which four suspension rods 12 are attached, said suspension rods 12 support the tub's weight 11 with the additional accessories to said cabinet, said suspension rods in addition of supporting static charges, mitigate the dynamic charge through shock absorbers present in its lower part, which help dissipate the vibrations caused by the washing motions.
Thus the tub 11 is hung from the suspension rods 12 by means of ears 35 placed in the lower portion of said tub 11 . The remaining peripheral equipment is mounted on said tub 11 , such as the motor 21 , in a preferred embodiment, a planetary gear for reduction 24 , which, in an alternative embodiment of the present invention, can be omitted thereby adjusting the pulley relationship 22 ; in this form, the pulley 22 with the largest diameter will be adjusted over the internal shaft 25 which will receive energy proceeding from the electric motor 21 thanks to the arrangement of pulleys 22 and band. In a preferred embodiment the shaft 25 on its upper part shall be coupled to a planetary gear for reduction 24 with the purpose of reducing angular speed, thereby accomplishing greater torque the exiting shaft from the planetary gear for reduction which reintegrates into one shaft 25 , on whose upper part the agitator is placed 13 . In an alternative embodiment the internal shaft 25 has a pulley with the largest diameter coupled to its lower part 22 and on its upper part is coupled to the agitator 13 . The interior of the hollow shaft 26 houses the internal shaft 25 . Said hollow shaft 26 is mechanically coupled to a clutch 28 , which can make both shafts 25 , 26 rotate together or independently, and also said hollow shaft 26 is mechanically coupled to the basket's center called the “hub” 32 , so that when shafts 25 , 26 are clutched and rotating together, the hollow shaft 26 shall transmit energy to the basket 10 so that it turns along with the agitator 13 .
The basket 10 is crowned with a balance hoop 27 which counteracts the unbalancing caused by the shifting of the wash load inside the basket 10 . In a preferred embodiment, the tub 11 on its upper part is joined to a covered tub which houses a grill 19 and a spray deflector 18 . The cabinet itself is covered with the main cover 30 which covers the washer's upper part 20 , said main cover 30 serves as a support to the crest (not shown) wherein the electric components such as the controls 40 , the interrupting or relief drivers, the pressure switch 41 etc are housed as well as the washer's cover or lid 29 through which the items to be washed shall be loaded.
As can be seen in FIGS. 3 , 4 the tub's bottom 11 which is crafted in its center by a truncated cone 49 which allows the liquid or washing mixture to slide to a lower area aided by the force of gravity, this lower zone is formed by a ring 50 having an inclined surface relative to a horizontal plane (example inclination may be represented by the angle β shown in FIG. 4 ) and whose lowest point coincides with the entrance to the trough 46 , wherein the liquid or washing mixture is collected to be extracted by a pump 15 whether it be for drainage or whether the liquid or washing mixture be transported to the spraying system. FIG. 5 shows the tub's lower side 11 and it is here that the series of reinforced ribs which have been implemented can be seen. It should be highlighted that a series of diametrical ribs 53 have been traced in cross shape. That is to say, they emerge from the sides of the ears 35 , as can be seen in FIG. 6 , and cross diametrically at the opposite ear 35 , discontinuing the ribs as they pass through the center, the remaining being the radial ribs 52 . In a preferred embodiment to the present invention, another set of diametric ribs 53 emanate from the tub's center 11 towards the periphery of the tub's bottom 42 , said diametric ribs 53 are preferably traced precisely in the middle of the diametric ribs which go from ear 35 to ear 35 . This intricate rib arrangement gives the bottom of the tub 42 greater rigidity with a minimum amount of material used. Using this intricate rib arrangement ensures the placement of sufficient material in the precise area where the forces require strength.
The ears 35 can be seen in FIGS. 1 a , 5 , 6 , 7 , 8 . It should be noted that said ears 35 are formed by a pair of petals 54 which wrap the shock absorbers from the suspension rod 12 as can be seen in FIG. 1 a . Said petals have the end result of distributing the final dynamic forces, that is, the forces which are generated when the washer is in a wash, centrifuge or rinse mode. In this way, said dynamic forces are not transmitted in their full capacity to the suspension rods' 12 shock absorbers, but rather, are diluted into the tub's body 11 .
That is, the suspension rod's 12 shock absorber makes contact on a horizontal plane which protrudes from the ear 35 . The lower side of said plane has a spherical surface which has an opening which can be coupled in a swivel form to the upper side of the suspension rod's shock absorber 12 . Said aperture allows the suspension rod access through said horizontal plane of the ear 35 allowing it enough space to allow for angular movement on the vertical axis, this being one degree of freedom: a second and third degree of freedom are obtained on the horizontal axis, allowing the tub 11 a limited translational movement.
In this way, this system ensures restricted amplitude of movement with 3 degrees of freedom, not allowing movement in the 3 remaining degrees of freedom. However, if the horizontal plane protruding from the ear 35 could be formed as a cantilevered beam (see FIG. 8 ) this would create a strong lever arm on the tub's 11 cylindrical wall 34 and create large forces on the tub's bottom 42 . In a best case scenario, this can cause deformities to said tub's parts 11 , which once said applied forces cease being applied, will return to its original shape. In another case, said deformities can be permanent or cause premature fatigue on said parts of the tub 11 . With the intent of reinforcing said protrusion from the ears 35 on the horizontal plane a pair of petals 54 are added to the ear which help distribute the dynamic forces over a greater area on the tub's 11 cylindrical wall 34 .
The mentioned petals possess an alternative embodiment from the present invention with reinforcement ribs 36 . The distinct shape of these ears 35 allow a better way to transmit the forces concentrated there unto a larger area of the tub's 11 cylindrical wall 34 and also restrain them to some degree from reaching the deepest part of the tub 42 , lessening the lever's effect on said deepest part 42 . As can be seen from the previous discussion as well as from the figures, this design can transmit to a great degree the forces on the tub 11 and dissipate them unto the tub's body transmitting these forces to a lesser degree on the suspension 12 . The ears' robust design 3 is more difficult to deform, thereby increasing the tub's life, lessening fatigue and additionally increasing the tub's total rigidity 11 .
Another facet of the present tub's 11 invention, making reference to FIGS. 1 a , 2 , 5 , 7 , 8 is based on the arch shaped reinforcements 39 which can be directed on the external side of the tub's 11 cylindrical wall 34 . Said arch's base is precisely on the side of the ear 35 , which itself serves as reinforcement to the ear 35 . It should also be noted that the lower part of the arch 39 presents a greater radial height, this helps increase moment of inertia in the lower part, which in turn helps the rigidity of the tub's lower part as well as aids in the distributing of forces over a greater area. Thus, when the arch's curvature increases in height over the tub's 11 cylindrical wall 34 , radial height decreases, understanding that the upper portion of the tub 11 does not require high rigidity, therefore being able to economize material with this design, as well as allowing for coherent distribution of dynamic and static forces. The arch as can be discerned, can be formed in different curvatures and configurations, the preferred curvature shall depend on the particular design of each tub, depending on variations of the ear's 35 design, the presence or lack of belts or cylindrical reinforcements 37 , and in case of the actual configuration of these, on the design of the mold itself, are among other factors which can alter the shape or curvature of the arch 39 , which is built with the best possible shape to ensure the best distribution of forces on the tub's 11 cylindrical wall 34 .
Now turning attention to the belts or cylindrical reinforcements 37 shown in FIGS. 1 a , 2 , 5 , 6 , 7 , 8 it can be seen that said belt or cylindrical reinforcements 37 can be developed preferably in the tub's lower part 11 surrounding the cylindrical wall 34 . The reinforcements 37 are ribs in rectangular or trapezoidal transverse sections, which protrude in radial shape from the cylindrical wall's 34 exterior surface. This allows for a greater moment of inertia giving the mid to lower area of the cylindrical wall 34 excellent rigidity which decreases the deformations caused to this area of the tub 11 and also allows for more efficient distribution of dynamic and static forces to which said tub 11 is subjected to.
The lobes 38 shown in FIGS. 1 a , 3 , 4 , 5 , 9 , 10 , 11 in addition to giving rigidity to the tub's 11 mouth 47 , confer a greater action radius to the basket 10 , since it is precisely in this area where the gap or space between the tub 11 and the basket 10 is decreased when the basket spins, this is due to the basket's 10 head movement which has its greatest translation movement on the horizontal plane at this point, taking into account that said basket 10 is fastened in its lower or deepest part to the hollow shaft 26 . So that when a considerable shift in the wash load causes imbalance within the basket 10 , the translational movement of the basket's 10 upper part is exacerbated and can indeed scrape the tub's 11 mouth 47 causing the tub 11 harm such as perforations to the cylindrical wall's 34 higher interior surface or in the best of scenarios, loss of energy due to friction caused by the surface contact between the tub 11 and the basket 10 . Thereby the lobes increase the space within which the basket 10 in case of being subjected to translational movement due to its imbalance, avoid to a great degree the scraping problem and as has been mentioned before, increase to a great degree the rigidity of the tub's 11 mouth 47 , which in a common tub 11 or one which does not possess said lobes 38 nor the arch 39 , due to the weight or static and kinematic forces which are transmitted to the tub 11 originating from the basket 10 when it is loaded with articles to be washed submerged in the washing mixture coupled to the lever arms which are generated in supporting the tub 11 to the suspension rods through the ears 35 , cause the tub's 11 mouth to lose its cylindrical shape tending to collapse inwardly or along the tub's 11 own symmetrical axis. In this way, said lobes 38 help avoid the inconveniences mentioned above.
The tub's 11 mouth 47 has an interesting spout 48 , which has the function of draining the washing mixture or liquid contained in the tub 11 , which for whatever reason is found in excess guaranteeing a maximum level of washing mixture or liquid within the tub 11 . This spout acquires particular relevance since it avoids, should the operator overfill the system with water or in case the pressure switch 41 or the full capacity valve 45 or electronic control 40 malfunction and cause the overfilling of water above the tub's 11 maximum water capacity and the washer 20 can then carry out the washing and rinsing functions. Said liquid or washing mixture excess has to be drained because otherwise the liquid or washing mixture can overflow from the tub 11 over its upper part with the liquid or washing mixture sliding in fountain form over the exterior surface of the tub's 11 cylindrical wall 34 , possibly causing the pumps or motors among other electrical devices to become wet when the overflow of liquid or washing mixture moistens the floor where the washer 20 is placed causing this flow of events to create a dangerous situation, which in a worst possible outcome, could lead to the operator's electrocution since the liquid or washing mixture previously mentioned, has a high water content and water is an electric conductor. In order to avoid such a dangerous situation, the spout 48 , has been designed as shown in FIGS. 1 a , 10 , 11 , as coupled via a ring, clasp or another securing mechanism to a sleeve 55 , which itself is a tube preferably made from a polyethylene extruded with low density, similar to a plastic bag with no bottom. Said sleeve 55 transports the excess liquid or washing mixture to the washer's 20 lower part.
Having fully described the present invention, it is found to attain a high degree of inventive activity, its industrial application undeniable, warning at the same time that a technician with knowledge in the area can discern alternative modalities which shall be included within the reach and spirit of the following claims.
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In a household washer which contains a tub with a cylindrical wall suspended by means of suspension rods, the tub also is comprised of ears with petals by which the tub is held in one extreme by suspension rods, at least one cylindrical reinforcement which surrounds the cylindrical wall, at least one pair of lobes in a substantially upper area of the tub, and additionally preferably one spout for over-flow in a substantially upper area of the tub.
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RELATED APPLICATIONS
This application claims benefit under 35 U.S.C. §119(a)-(d) of German application DE 10 2010 011 895.8, filed Mar. 18, 2010, the disclosure of which is incorporated herein by reference
FIELD
Embodiments of the invention relate to a semipolar semiconductor crystal comprising a group-III-nitride (III-N) as well as to a method for manufacturing the same.
BACKGROUND
Semiconductor materials formed from group-III-group-V compounds are primarily used in light-emitting diodes (LEDs) based—among others—on their property to emit light in a broad wavelength range. In the following “III” and “V” denote elements of the corresponding main group of the periodic table of chemical elements. In particular, group-III-nitride compounds turned out to be specifically suitable for the green to ultraviolet wavelength range, for example GaN (gallium nitride), InGaN (indium gallium nitride), AlGaN (aluminium gallium nitride) and AlGaInN (aluminium gallium indium nitride).
The above referred to compounds are commonly grown by metal organic vapour phase epitaxy (MOVPE), hydride vapour phase epitaxy (HVPE) or molecular beam epitaxy (MBE), etc. on a start substrate, in order to manufacture a monocrystal. Unfortunately, GaN-monocrystals substrates having a satisfactory size on which to grow the compounds are generally not presently available. Thus, “foreign” substrates, wherein materials comprising an almost compatible crystal system are utilized. For gallium nitride, sapphire (Al 2 O 3 ) or silicon carbide (SiC) are typically used. When forming the final end products, the substrates are removed from the gallium nitride-monocrystal via chemical or mechanical methods, etc.
Gallium nitride (by which term in the following also shall be comprised its ternary or quaternary compounds) includes a hexagonal wurtzite crystal grid and thus has a similar crystal structure as sapphire, which comprises a trigonal corundum-grid. Crystal growth is currently, generally performed along the c-axis [0001] during epitaxy, i.e., perpendicular to the c-plane (0001), the c-axis being the symmetry axis of the hexagonal structure. The surface of the sapphire substrate (wafer) provided as a substrate surface on which the crystal is grown is chosen to have lattice constants sufficiently close to those of the crystal c-plane to support acceptable growth of the crystal. The c-plane (0001) thus also characterizes the final GaN-crystal as it is then utilized, for example, in LEDs.
Due to the polar structure of the crystal along the c-axis [0001], considerable piezoelectric fields may arise in the case of GaN in conjunction with the crystal geometry. A band shift may be generated along the c-axis from which the so-called quantum confined stark effect (QCSE) may result. In the QCSE, distances between wave functions of electrons and holes in quantum wells (QW) produced along this direction by alternating layer sequences, are increased. The increase leads to a red shift and reduced recombination rate of the electrons and holes in the LEDs, etc.
The c-plane as the surface of the GaN-monocrystal is thus denoted as “polar”. In contrast thereto, the m-planes {1-100} or a-planes {11-20} in the GaN-monocrystal, which are perpendicular to the c-plane, are nonpolar, since the Ga and N-atoms are positioned in the same plane. Consequently, many attempts were made to manufacture GaN-monocrystals having surfaces, which are correspondingly oriented at the m- or a-planes.
Since, however, as described above, foreign substrates have to be used as a start material, the problem arises just in these cases, that stacking-faults, etc. may occur.
Nevertheless, Okado N. et al.: in “ Direct growth of m - plane GaN with epitaxial lateral overgrowth from c - plane sidewall of a - plane sapphire ”, Appl. Phys. Expr. 1 (2008), page 111101 report that nonpolar GaN (m-plane), or {1-100}, may be grown via MOVPE on a sapphire substrate having {11-20}-orientation (a-plane).
For this purpose, trenches separated by ridges are formed in the sapphire substrate by means of reactive ion-etching (RIE). Lateral facets of the ridges include an inclination of 68 or 79 degrees, respectively, with respect to the horizontal direction. The top face of the ridges is masked by a SiO 2 layer having a thickness of 200 nm, in order to inhibit growth of GaN on top of the same. The top faces of the ridges have a width of 4 μm, while the trenches have a corresponding width of 2 μm. The bottom face of the trenches has a width of only 0.5 μm due to the inclined facets.
The epitaxial growth process started horizontally in the trenches in c-direction [0001] at the facet, which is more inclined (79 degrees), since the angle between the c-direction and the surface normal herein amounts to “only” 11 degrees. After reaching the opposite wall, the growth continues vertically with lateral overgrowth of the ridges, wherein the direction in the gallium nitride now corresponds to an {10-10}-orientation (m-plane) due to a 30-degrees-rotation. In view of the lateral overgrowth over the ridges, the individual layers finally merge upon further growth.
A surface roughness measurement conducted with an atomic force microscope (AFM) amounted to 1.1 nm (are size 5×5 μm, RMS), whereas the crystal quality has been determined by an x-ray measurement via the Rocking Curve to yield a full width half maximum (FWHM) of 500 arc seconds azimuthally in the <10-10>-direction, or of 650 arc seconds azimuthally in the <0001>-direction for the (10-10)-surface of the grid.
The formation of a semipolar GaN-layer was thereafter described by Okada, N. et al.: in “ Growth of semipolar (11-22) GaN - layer by controlling anisotropic growth rates in r - plane patterned sapphire substrate ”, Appl. Phys. Expr. 2 (2009), page 091001. “Semipolar” denotes, polarity values between the extremes of the c-plane polarity and the m- or a-plane polarity.
By an appropriate choice of the process conditions in the MOVPE-process it was possible to omit the masks upon the ridges. The top face of the ridges were oriented along the r-plane (1-102) of the sapphire substrate, whereas the lateral facets were again inclined (about 32 degrees with respect to the horizontal direction), however, this time its normals were oriented parallel to the c-plane inclined within the sapphire substrate, such that a single-sided growth in c-direction [0001] in the trench was guaranteed. The r-plane is not perpendicular to the c-plane. Due to the 30 degree-rotation about the c-axis upon growth on the sapphire, the gallium nitride crystal grid achieves by its [11-22]-direction in vertical direction the same spatial orientation as compared with the [1-102]-direction of the crystal grid of the sapphire substrate.
Regarding crystal quality, rocking curve-measurements yielded full width half maximum (FWHM) values of 720, or 319 arc seconds, parallel and perpendicular to the c-direction for the (11-22)-grid planes, respectively.
The growth has been supported particularly by the almost similar angles between the r-plane and the c-plane of the sapphire and between the (11-22)-plane and the c-plane of the gallium nitride.
From document U.S. Pat. No. 7,220,324 B2 it is known to grow a GaN-layer having {10-11}-orientation on a {10-10}-spinel substrate (MgAl 2 O 4 ). The spinel substrate thereby is not structured, since the method of forming ridges and trenches followed by a two-step growth due to the facet inclinations and the small area sizes, is considered insufficient and complex.
From document U.S. Pat. No. 7,645,688 B2 it is known to use a (11-23) oriented sapphire substrate to grow thereupon a nonpolar gallium nitride layer oriented in the direction of the m-plane (<10-10>-directions). The substrate is substantially unstructured. One would basically select an r-plane sapphire substrate in order to grow nonpolar (11-20)-GaN, i.e., a-plane GaN. However, it is proposed therein to use (11-23)-oriented sapphire substrate instead, since the grid dimensions in both planes (sapphire-GaN) are compatible with each other and m-plane-GaN is considered being more stable than a-plane-GaN.
SUMMARY
Embodiments of the invention provide new methods of manufacturing III-N-monocrystals having semipolar properties.
According to an embodiment of the invention, a method of manufacturing a semipolar semiconductor crystal comprising a group-III-nitride (III-N) includes, among others, steps of providing a start substrate comprising sapphire (Al 2 O 3 ) and having a first surface parallel to a crystallographic plane of the sapphire, and epitaxially growing a semipolar crystal layer comprising the group-III-nitride (III-N) on the start substrate above the first surface thereby forming a second surface, which is substantially parallel to the first surface and is formed by a semipolar crystallographic plane of the group-III-nitride.
According to one embodiment of the method it is proposed to obtain a semipolar {20-2l} oriented III-N-layer, in particular a gallium nitride layer, by epitaxial growth starting from a sapphire substrate oriented in a predetermined direction. l herein represents an integer, namely l=1, 2, 3, 4 . . . . The results found herein with regard to surface roughness and crystalline quality of the final product, surprisingly, are substantially improved relative to hitherto known semipolar or nonpolar GaN-layers having other orientations.
Particularly high crystalline qualities have been found for a combination of a {11-23} oriented sapphire substrate having a {10-11} oriented III-N layer grown thereupon, i.e., l=2 in the expression for orientation given in the preceding paragraph. (It is noted that setting l=2 in the expression for orientation, {20-2l}, in the preceding paragraph yields {20-22}. Conventional nomenclature mandates removing common denominators from the orientation coordinates so that {20-22} becomes, in accordance with the convention, {10-11}.)
Alternatively, also the following combinations of surface crystal orientations for sapphire and GaN may be utilized: {20-21}-GaN (i.e., l=1) on {22-43}-sapphire and {10-12}-GaN (i.e., l=4) on {11-26}-sapphire. Further to the above described family of {20-2l}oriented III-N-layers, also a combination of {11-21}-GaN on {10-11}-sapphire is comprised by embodiments of the invention. It has been found, that the surface roughness and the crystalline quality of the final product also herein surprisingly delivers remarkably improved results. The method is for all combinations substantially the same.
The III-N-, or GaN-layer, respectively, grows “upon” the surface of the sapphire. “Upon” herein denotes the space extending along the normal vector of the sapphire surface. It is possible that also layers of other materials, such as for example, nucleation and/or mask materials, may be positioned within this space partially between the sapphire and the III-N-, or GaN-layer respectively.
Regarding the sapphire, the “surface” denotes a large area surface plane (ground, lapped, polished, grown, etc.) that is present before any structuring such as the formation of trenches, etc. is applied, wherein the specified crystal plane is oriented parallel to that “surface”.
According to an embodiment the formation of a trench or of multiple trenches is carried out in the sapphire substrate. The lateral facet(s) formed thereby serves as a starting point for crystal growth in c-direction at first. After reaching an opposite facet, the growing crystal material in trenches overflow and crystal material from neighbouring trenches coalesce to yield a closed {10-11}-plane, i.e. are grown together, and the growth continues in <10-11>-direction.
It has been found, that agreement of an angle between the <11-23>-directions and the c-plane of the sapphire and between the <10-11>-directions and the c-plane of the gallium nitride suffices to ensure crystal growth at high quality.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF FIGURES
Embodiments of the invention will be better understood with reference to specific embodiments when taken in conjunction with the accompanying drawings. Therein
FIGS. 1 a - 1 e show steps for manufacturing semipolar {10-11}-gallium nitride by virtue of a schematical cross-sectional profile according to an embodiment of the invention;
FIGS. 2 a - 2 b schematically show initial and final stages respectively of crystal growth in accordance with an embodiment of the invention;
FIGS. 2 c - 2 f show vector diagrams having spatial orientations of crystal directions during growth of a crystal in processes illustrated in FIGS. 1 a - 1 e and FIGS. 2 a - 2 b in accordance with an embodiment of the invention;
FIG. 3 shows a diagram of a rocking curve measured by x-ray diffraction from {1-23}-planes of a sapphire substrate and diffraction from {10-11}-planes of a GaN-layer (ω-2θ-scan) grown on the substrate in accordance with an embodiment of the invention;
FIG. 4 shows a recording by a scanning electron microscope of a cross-section through the sapphire substrate and GaN-layer grown thereupon according to a further embodiment of the invention; and
FIG. 5 shows a photo luminescence spectrum of the exemplary GaN-crystal layer of FIG. 4 according to an embodiment of the invention.
DETAILED DESCRIPTION
A method for manufacturing a semipolar gallium nitride according to an embodiment of the invention is schematically illustrated in FIGS. 1 a - 1 e.
In a first step ( FIG. 1 a ) a planar wafer made from sapphire (Al 2 O 3 ) is provided, which has a surface 3 , that corresponds to a crystal plane of orientation {11-23}. The wafer serves as a start substrate 2 for growing gallium nitride thereon. Such wafers are commercially available and in this specific example a 2″-wafer having a thickness of 430 μm was used. Modifications regarding the diameter and thickness are of course possible.
In a second step ( FIG. 1 b ) the start substrate 2 is lithographically structured. For this purpose, a first mask layer 8 made from, optionally, SiO 2 having a thickness of 200 nm is deposited. A photoresist is then deposited upon the SiO 2 -mask layer 8 and structured with a stripe pattern using commonly applied lithographical structuring methods. Then, a second mask layer 4 made from nickel and gold and having thickness of 550 nm is deposited. Thereafter, the photoresist is removed (note that the photoresist is not shown in FIG. 1 b , however, see arrows regarding numeral 6 ), as a result of which only those regions of the second nickel-gold-mask layer remain adhering, which have been deposited directly on the first mask layer 8 , while the other regions are removed together with the photoresist (“lift-off-process”). Alternatively, the Ni—Au-mask might also be etched. The stripes are optionally straight and optionally extend in the <10-10>-direction, which is parallel to the surface, are arranged parallel to each other and have a width of about 3 μm. The openings in the gold-nickel mask also, optionally, have a width of about 3 μm. Whereas, in the above example, the stripes and their separation are equal to 3 μm, generally the stripes and their separations do not have to be equal, and advantageously have values in a range from about 1 μm to about 10 μm.
Subsequently, the start substrate is exposed including both mask layers to a reactive ion beam etching process (RIE, numeral 4 , or ICP-RIE), or is alternatively exposed to another arbitrary, preferably dry-chemical etching process, in which a trench 10 is etched into the sapphire crystal having a depth of between about 0.8-1.3 μm. The first SiO 2 -mask layer is thereby also structured and remains only being present in regions, where it is protected by the Ni—Au-mask layer.
The trench walls 12 , 16 formed thereby have for example an inclination angle, as measured from parallel to surface 3 is equal to about 75°. In this very specific example, that shall not be generalized to limit the scope of the invention, a power of 300 W, supply of gases of BCl 3 , Cl 2 and Ar in a ratio of 2:2:1 and a pressure of 20 mTorr has been used for the etch process.
Whereas, in the above example, an inclination angle for the trench walls was 75° an inclination angle in accordance with an embodiment of the invention is advantageously between about 40° and 80°. Optionally, the inclination angle is between about 50° and 70°. Optionally, the inclination angle is substantially equal to about 62°. For 62°, the plane of the trench wall is substantially oriented parallel to the sapphire c-plane.
Thus, on the one side a facet 12 forms, whose surface is oriented roughly parallel to the (0001)-plane (c-plane) of the sapphire crystal such that a c-growth may be initiated—while on the facet 16 formed on the opposite side such growth is inhibited, since the deviation of its inclination from the c-orientation of the sapphire is too large. Between the trenches, ridges 11 remain in the sapphire substrate. These ridges thus comprise on their lateral sides the inclined facets as well as between the facets the top face, which corresponds to the original surface of the sapphire having a corresponding crystal orientation. The top face is still covered with the mask layer made from SiO 2 .
Further, the lithographical structuring process is optionally arranged such that the trenches respectively extend along a <10-10>-direction (cf. FIG. 2 ), i.e., they are perpendicular to the m-plane of the sapphire (Al 2 O 3 ) together with its facets 12 . The normal vector of the a-plane would be directed roughly to the upper left side in the Figures.
In the illustrated embodiment, the mask layer 8 made from SiO 2 is provided below the Ni/Au-mask layer 4 and is then structured together with the sapphire. However, it may also be conceived that the SiO 2 -mask layer is deposited after the etching of the Ni/Au-mask layer. Herein, the corresponding masks have nevertheless to be aligned with respect to each other. The sequence of masking and the materials employed thereby may be modified in an appropriate manner using alternatives known to the person skilled in the art.
The remaining portions of the Ni/Au-mask layer are removed by a wet-chemical method (for example 6 parts H 2 O, 2 parts HCl and 1 part H 2 O 2 ), whereas the SiO 2 -mask layer may remain in position.
The MOVPE-growth optionally starts with depositing an oxygen-doped low temperature nucleation layer (not shown in the Figures) made from aluminium nitride (AlN).
The growth process is performed metal organic vapour phase epitaxy (MOVPE). MBE, HVPE and/or other suitable epitaxial methods known in the art. Nevertheless, MOVPE advantageous for growth. Moreover, a nucleation may optimally be performed on sapphire using MOVPE. Alternatives known to the person skilled in the art, in particular the above described methods, shall nevertheless be comprised by the general process proposed herein. In the specific example, a horizontal flow reactor Aixtron-200/4 RF-S was employed. trimethyl gallium (TMGa), trimethyl aluminum (TMAl) and highly purified ammonium gas (NH 3 ) were used as initial substances. Hydrogen, optionally mixed with nitrogen, is used as a carrier gas. The process temperature was controlled using the pyrometer on a downstream side of the substrate holder. In this example, about 1 μm GaN was grown at a temperature of 1130 degrees C. and a total pressure of 150 hPa.
Under these conditions the GaN-growth starts from the lateral facet 12 , which as described above corresponds exactly or substantially or even only roughly to the c-plane of sapphire substrate 2 , i.e., in all trenches 10 only on one side. On the other side of the trench some small amount of parasitic deposition of GaN may occur, however, with a considerably reduced growth rate. The growth on the top face of ridge 11 is inhibited by the second mask layer (SiO 2 ). The growth direction corresponds to the c-direction of the sapphire 2 . Thereby, the crystal layer 18 of gallium nitride also continues to grow in its c-direction. As can be seen from the first sub-step of the inclined horizontal growth schematically represented by arrows 17 in the trench displayed in FIG. 1 d , a tip forms in the growing gallium nitride, which approaches wall 16 of a corresponding opposite ridge 11 .
Once tips of GaN 18 reach the opposite ridges, or parasitic depositions of GaN on the opposite ridges, the GaN in the trenches overflow, and GaN from adjacent trenches 10 merge. Then substantially vertical GaN crystal growth 19 ( FIG. 1 e ) beyond the upper edge of the trench begins and marks the beginning of a second sub-step. The process conditions are, optionally, not changed in the second sub-step. Nevertheless, it also comes within the scope, to individually adjust the process conditions in order to enable improved growth. In the present example, growth proceeds in a vertical direction in the second sub-step.
After merging of adjacently growing crystal layers 18 , these contact each other and form a common, continuous surface 22 , as may be seen from FIG. 1 e . Between the crystal layer 18 of GaN and the start substrate 2 of sapphire, so-called voids 20 may occur at the edges of the trenches opposing facets 12 , i.e. facets 16 , since the epitaxial growth does not necessarily fill the complete trench 10 . The same may occur for a region between the adjacently vertically growing crystal layers 18 directly upon the top face 13 of the ridge, i.e., upon the masking layer 8 (cf. voids 21 ).
FIG. 2 once schematically more shows in simplified manner the two sub-steps of crystal growth at first in c-direction ( FIG. 2 a ) and then in <10-11>-direction ( FIG. 2 b ). FIG. 2 c shows the crystal direction each in sapphire and in GaN with respect to the illustrations of FIG. 1 a - e , or FIG. 2 a - b , respectively, wherein in addition to the manufacturing of semipolar {10-11}-GaN are also shown further embodiments of the invention in an exemplary manner.
FIG. 4 shows a recording of a scanning electron microscope indicating a cross-section through the sapphire substrate 2 having a GaN-layer 18 grown thereupon according to a further embodiment of the invention. In contrast to the first embodiment, the widths of top faces 13 of the ridges are equal to about 4 μm and the corresponding widths of the trenches are equal to about 1.2 μm at the height of the upper edge of the trenches, or about 0.6 μm at the height of the bottom face 14 of the trenches. The recording shows a situation after the growing of about 1 μm GaN. The crystal layers 18 are in a state shortly before merging and the formation of a common surface 22 .
The test substrates (sapphire 2 having the GaN-crystal layer grown thereupon) have been investigated in the embodiments in more detail. For quantifying the crystal quality, Rocking Curves (XRC) have been determined and ω-2θ-scans have been performed in the course of high resolution X-ray diffraction measurements (XRD). Further, low temperature photo luminescence spectra (PL, at 14K) have been recorded. The latter allow to conclude on defects, in particular stacking-faults in the basal plane. An ω-2θ-scan is shown in FIG. 3 , a PL-spectrum is illustrated in FIG. 5 .
In FIG. 3 the (10-11)-orientation of the grown crystal layer 18 of GaN may particularly be verified from the ω-2θ-scan. It is clearly visible in FIG. 3 , that only those peaks occur, which are either associated with the {11-23}-family of sapphire (Al 2 O 3 ), i.e. of the start substrate 2 , or with the {10-11}-family of the gallium nitride (GaN) 18 .
The corresponding measurement of the Rocking Curve (XRC) revealed full width at half maximum (FWHM) values of less than 400 arc seconds for the symmetric (10-11) reflection (diffraction peak, see FIG. 3 ) as well as for the asymmetric (0002)- or (10-12)-reflections (not shown in FIG. 3 ). The full widths at half maximum shed light on the crystal quality. 400 arc seconds represents a comparatively sound value for a material having a non-c orientation. The individually indicated diffraction peaks specify, what has exactly been measured and are used to interpret the measured widths. Some peaks turn out to be intrinsically narrower, while others are intrinsically broader. It is noted that the Rocking Curve measurements were performed—as common in semiconductor and/or epitaxy analysis—using Cu Kα—emission for the X-rays in high resolution X-ray diffractometry (XRD). FWHM values set forth herein and are based on this quasi-standard emission.
FIG. 5 shows the result of the photo luminescence-(PL)-spectra, recorded at 15 K (upper curve) and at 295 K (bottom curve). A near band edge emission (NBE) is clearly visible at 3.464 eV. In GaN-crystals grown on sapphire with semi- or nonpolar property, this luminescence is usually less pronounced, while therein the luminescence of faults dominates. Nevertheless, peaks are visible in FIG. 5 —for example at 3.43 eV or at 3.30 eV—which may be attributed to such faults, in particular stacking-faults.
For determining the roughness of the (10-11)-surface obtained in the embodiment, measurements using an atomic force microscope (AFM), have been performed. Within an area having a size of 3 μm×3 μm a roughness of less than 0.3 nm (route mean square RMS) has been determined, and within an area having a size of 1 μm×1 μm a roughness of even less than 0.1 nm (RMS) has been measured.
The above described examples show investigations of GaN-crystal layers 18 grown up to about 1 μm thickness. However, practice of embodiments of the invention is of course not limited to layers of about 1 μm. Embodiments of the invention may be used to provide considerably thicker, merged GaN-layers 18 , from which complete substrates for use in manufacturing opto-electronic components or components for sensor technologies, high frequency applications, etc. may be formed. Such substrates, which include the above described properties with regard to crystal quality and surface quality, are particularly advantageous in the manufacturing of components.
Hence, combinations of start substrate 2 with crystal layers 18 grown thereupon, as well as already separated, large-scaled III-N- or GaN-crystal layers are comprised by the scope of embodiments of the invention. Diameters of 2″ or 4″ or even more are realistic. No limit for the diameter is provided by embodiments of the invention.
Using MOVPE, moderate growth rates of about 2 μm/h may be obtained at present. In this case, a sapphire-wafer is preferably structured at first, wherein the GaN-layer is then grown using a MOVPE-method and after some μm the layer for the component is deposited.
In order to obtain considerably thicker layers (“a bulk” material), it may also be advantageous to employ a HVPE-method (growth rate 100 μm/h and more). In this case, some mm up to some cm can be deposited. Thereafter, the crystal or “boule” is cut into individual wafers with for example identical orientation and then the component layers are grown subsequently using MOVPE or MBE in corresponding reactors onto the resulting wafers.
In some embodiments of the invention, to grow thick semipolar GaN crystals, a thin GaN MOVPE-layer is formed as described above and followed by transferring the wafer into a HVPE-process (HVPE-reactor) for growing a comparatively thick crystal thereupon.
Further, in the above described methods detailed values for the process conditions (temperature, pressure, precursor gases, etch methods, epitaxy methods, number of process steps, materials for mask or nucleation layers, layer thicknesses, trench widths, etc.) have been provided. However, it pertains to the person skilled in the art to recognize that also modifications or deviations from such conditions are possible, such as they are basically known from the manufacturing of GaN or III-N-compound materials each having other known crystal orientations.
With regard to the mask layers, SiN or Al 2 O 3 or other materials may for example also be considered. With regard to the nucleation layers it may be referred to various available literature, for example Kuhn, B. et al., in Phys. Status Solidi A. 188, p. 629, 2001, or Hertkorn, J. et al., in J. Cryst. Growth 308, p. 30, 2007 in the case of low temperature nucleation layers, to which the present method shall, however, not be limited.
With regard to the temperatures in the reactor, there is a dependence among others also from the respective type of reactor, such that the above described values are only valid for the specific example. Even for the specified type of reactor there may be made deviations from the temperatures. As a MOVPE-reactor or a HVPE-reactor, any type be it commercially available or not, may be considered, which is capable of growing a III-N-crystal layer.
Corresponding considerations do not only relate to the exemplary combination of start crystal and grown crystal as described above. Rather, these also relate to modifications including the following combinations of surface crystal orientations for sapphire and GaN: {2-201}-GaN on {22-43}-sapphire, {10-12}-GaN on {11-26}-sapphire as well as {11-21}-GaN on {10-11}-sapphire.
In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb.
Descriptions of embodiments of the invention in the present application are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments utilize only some of the features or possible combinations of the features. Variations of embodiments of the invention that are described, and embodiments of the invention comprising different combinations of features noted in the described embodiments, will occur to persons of the art. And, unless otherwise stated, adjectives such as “substantially” and “about” modifying a condition or relationship characteristic of a feature or features of an embodiment of the invention, are understood to mean that the condition or characteristic is defined to within tolerances that are acceptable for operation of the embodiment for an application for which it is intended. The scope of the invention is limited only by the claims.
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A method of manufacturing a semipolar semiconductor crystal comprising a group-III-nitride (III-N), the method comprising: providing a substrate comprising sapphire (Al 2 O 3 ) having a first surface that intersects c-planes of the sapphire; forming a plurality of trenches in the first surface, each trench having a wall whose surface is substantially parallel to a c-plane of the substrate; epitaxially growing a group-III-nitride (III-N) material in the trenches on the c-plane surfaces of their walls until the material overgrows the trenches to form a second planar surface, substantially parallel to a (20-2l) crystallographic plane of the group-III-nitride, wherein l is an integer.
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FIELD OF THE INVENTION
[0001] The invention is related to whole empty viral particles of the infectious bursal disease virus (IBDV), with immunogenic activity against IBDV, their production by means of genetic engineering and applications thereof, particularly in the production of animal health vaccines, for example, in the manufacture of vaccines against the avian disease called infectious bursal disease caused by IBDV and in the manufacture of gene therapy vectors.
BACKGROUND OF THE INVENTION
[0002] During the last four decades of the 20 th century, the appearance and global spreading of an avian disease called infectious bursal disease (IBD) has occurred. IBD is characterized by the destruction of pre-B lymphocyte populations residing in the bursa of Fabricius of infected animals (Sharma J M et al. 2000. Infectious bursal disease virus of chickens: pathogenesis and immunosuppression. Dev Comp Immunol. 24:223-35). This disease is caused by the infectious bursal disease virus (IBDV) belonging to the Birnaviridae family (Leong J C et al. 2000. Virus Taxonomy Seventh Report of International Committee on Taxonomy of Viruses. Academic Press, San Diego, Calif.). In spite of the implementation of intensive vaccination programs, based on the use of combinations of live and inactivated vaccines, outbreaks of IBD are still reported in all chicken meat-producing countries (van den Berg T P et al. 2000. Infectious bursal disease (Gumboro disease). Rev Sci Tech. 19:509-43).
[0003] The virions of the infectious bursal virus lack a lipid envelope, have an icosahedral structure (symmetry T=13) and have a diameter of 65-70 nm (Bottcher B. et al. 1997. Three-dimensional structure of infectious bursal disease virus determined by electron cryomicroscopy. J. Virol. 71:325-30; Castón J. R., et al. 2001. C terminus of infectious bursal disease virus major capsid protein VP2 is involved in definition of the t number for capsid assembly. J. Virol. 75:10815-28). The capsid is formed by a single protein layer containing four different polypeptides called VPX, VP2, VP3 and VP1, respectively. The VPX, VP2 and VP3 proteins are produced by means of proteolytic processing of a precursor, referred to as viral polyprotein, encoded by genomic segment A. The VP1 protein is produced by means of expression of the corresponding gene encoded by segment B.
[0004] The viral polyprotein, synthesized as a precursor of 109 kDa, is processed cotranslationally, giving rise to the formation of three polypeptides referred to as VPX, VP3 and VP4. VP4 is responsible for this processing (Birghan C. et al. 2000. A non-canonical Ion proteinase lacking the ATPase domain employs the Ser-Lys catalytic dyad to exercise broad control over the life cycle of a double-stranded RNA virus. Embo J. 19:114-23). VP3 is a polypeptide of 29 kDa forming trimeric subunits coating the inner layer of the capsid. VPX (also known as pVP2) undergoes a second proteolytic processing giving way to the mature form of the protein called VP2. The outer surface of the virions is formed by trimeric subunits constituted of a variable ratio of VPX and VP2 (Chevalier C et al. 2002. The maturation process of pVP2 requires assembly of infectious bursal disease virus capsids. J. Virol. 76:2384-92; Lombardo, E., et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83). It has been suggested that the conversion of VPX to VP2 is associated with the formation of mature capsids (Chevalier, C., et al. 2002. The maturation process of pVP2 requires assembly of infectious bursal disease virus capsids. J. Virol. 76:2384-92; Martínez-Torrecuadrada, J. L. 2000. Different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. Virology. 278:322-31). The polyprotein proteolytic processing sites have been characterized (Da Costa, B., et al. 2002. The capsid of infectious bursal disease virus contains several small peptides arising from the maturation process of pVP2. J. Virol. 76:2393-402; Sánchez, A. B. and Rodríguez, J. F. 1999. Proteolytic processing in infectious bursal disease virus: identification of the polyprotein cleavage sites by site-directed mutagenesis. Virology. 262:190-9), which allows for a reliable expression of the polypeptides of the capsid. The viral RNA-dependent RNA polymerase (RdRp) viral, called VP1, interacts with the VP3 protein, giving rise to a complex facilitating its encapsidation (Lombardo E et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83; Tacken, M., et al. 2000. Interactions in vivo between the proteins of infectious bursal disease virus: capsid protein VP3 interacts with the RNA-dependent RNA polymerase, VP1. J. Gen. Virol. 81 Pt 1:209-18). The domain of the protein VP3 responsible for this interaction is located in its 16 C-terminal residues (Maraver, A., et al. Identification and molecular characterization of the RNA polymerase-binding motif of the inner capsid protein VP3 of infectious bursal disease virus. J. Virol. 77:2459-2468). The protein VP3 interacts with RNA non-specifically. This reaction does not require the existence of specific sequences in the RNA molecule (Kochan, G., et al. 2003. Characterization of the RNA binding activity of VP3, a major structural protein of IBDV. Archives of Virology 148:723-744). As with that observed with other internal capsid proteins of other viruses, it seems likely that VP3 stabilizes the genomic RNA in the viral particle.
[0005] Conventional vaccines used for controlling infectious bursal disease are based on the use of strains, with different degrees of virulence, of the IBDV itself grown in cell culture or in embryonated eggs. The extracts containing the infectious material are subjected to chemical inactivation processes to produce inactivated vaccines, or else are used directly to produce live attenuated vaccines (Sharma, J. M., et al. 2000. Infectious bursal disease virus of chickens: pathogenesis and immunosuppression. Developmental and Comparative Immunology 24:223-235; van den Berg, T. P., et al. 2000. Rev. Sci. Tech. 2000, 19:509-543). This latter type of vaccine has the typical drawbacks associated with the use of live attenuated vaccines, specifically, the risk of mutations reverting the virulence of the virus or causing it to lose its immunogenicity.
[0006] Recombinant subunit vaccines containing the IBDV protein VP2 expressed in several expression systems, for example, bacteria, yeasts or baculovirus, usually in fusion protein form, have been disclosed. The results obtained in chicken immunization tests with said vaccines have not been completely satisfactory.
[0007] Empty viral capsids or virus-like particles (VLPs,) constitute an alternative to the use of live attenuated vaccines and of recombinant subunit vaccines. VLPs are obtained by self-assembly of the subunits constituting the viral capsid and mimicking the structure and antigenic properties of the native virion, even thought they lack genetic material, as a result of which they are incapable of replicating themselves. Apart from their application for vaccination purposes, VLPs can be used as vectors of molecules of biological interest, for example, nucleic acids, peptides or proteins. By way of illustration, parvovirus VLPs (U.S. Pat. No. 6,458,362) or human immunodeficiency virus (HIV) VLPs (U.S. Pat. No. 6,602,705), can be mentioned.
[0008] Morphogenesis is a vital process for the viral cycle requiring successive steps associated to modifications in the polypeptide precursors. As a result, viruses have developed strategies allowing the sequential and correct interaction between each one of its components. One of these strategies, frequently used by icosahedral viruses, is the use of polypeptides coming from a single polyprotein as the base of its structural components. In these cases, the suitable proteolytic processing of such polyprotein plays a crucial role in the assembly process.
[0009] The production of several IBDV VLPs by means of expression of the viral polyprotein using different expression systems have been disclosed. In 1997, Vakharia disclosed for the first time, obtainment of IBDV VLPs in insect cells (Vakharia, V. N. 1997. Development of recombinant vaccines against infectious bursal disease. Biotechnology Annual Review 3:151-68). Later, in 1998, the research group to which the inventors belonged proved the possibility of obtaining IBDV VLPs in mammalian cells (Fernández-Arias A et al. 1998. Expression of ORF A1 of infectious bursal disease virus results in the formation of virus-like particles. J. Gen. Virol. 79:1047-54). In 1999, an article was published disclosing the obtaining of IBDV VLPs in insect cells by another research group (Kibenge, F. S., et al. 1999. Formation of virus-like particles when the polyprotein gene (segment A) of infectious bursal disease virus is expressed in insect cells. Can. J. Vet. Res. 63:49-55). A subsequent study, published by the laboratory to which the inventors belong, in collaboration with INGENASA S. A., proved that the morphogenesis of IBDV VLPs in insect cells infected with recombinant baculoviruses expressing the IBDV polyprotein is very ineffective and leads to the major accumulation of abnormal tubular structures (Martínez-Torrecuadrada, J. L., et al. 2000. Different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. Virology 278:322-331). These results were subsequently corroborated (Chevalier, C., et al. 2002. The maturation process of pVP2 requires assembly of infectious bursal disease virus capsids. J. Virol. 76:2384-92). In that same article, that group of researchers proved the possibility of obtaining an efficient morphogenesis by means of the expression of a chimeric polyprotein formed by the fusion of the open reading frame (ORF) corresponding to the green fluorescent protein (GFP) and to 3′ end of the open reading phase of the IBDV polyprotein. The expression of this chimeric polyprotein leads to the formation of recombinant IBDV VLPs, containing in their interior a VP3-GFP recombinant fusion protein, different from the one present in the IBDV virions. On the other hand, the results disclosed in this latter research project do not provide information concerning the mechanism responsible for the ineffectiveness of the morphogenetic process of the IBDV VLPs in insect cells.
[0010] It is important to stress that all the VLPs disclosed previously lack the VP1 protein, which is present in the IBDV virions. The only reference to the obtaining of IBDV VLPs including VP1 have been carried out by researchers of the laboratory to which the inventors belong (Lombardo, E., et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83), using the vaccine virus as the vector, which prevents the possible use of said VLPs for vaccination purposes.
[0011] The different processes of producing IBDV VLPs previously described suffer from different defects that reduce or prevent their applicability for the generation of vaccines against IBDV, given that:
i) the production of IBDV VLPs in mammalian cells is based on the use of recombinants of the vaccine virus; however, that production system has a very high cost and, as it uses a recombinant virus capable of infecting both mammals and birds, it does not meet the biosafety conditions necessary for its use as a vaccine; ii) the production of IBDV VLPs in insect cells using conventional expression systems, i.e. recombinant baculoviruses only expressing the viral polyprotein, is very inefficient, leading to practically no production of VLPs; iii) the production of IBDV VLPs in insect cells by means of the expression of a chimeric polyprotein (formed by the fusion of the ORF corresponding to the GFP at the 3′ end of the ORF corresponding to the IBDV polyprotein) results in the production of IBDV VLPs containing a fusion protein VP3-GFP, which introduces a protein element not present in IBDV virions, of unknown effect and of doubtful applicability in the chicken food chain for human consumption, and iv) none of the systems described above for the production of IBDV VLPs based on the use of recombinant baculoviruses allows for obtaining IBDV VLPs containing all the antigens present in the IBDV virions.
SUMMARY OF THE INVENTION
[0016] The invention generally is aimed at the problem of providing new effective and safe vaccines against the infectious bursal disease virus (IBDV).
[0017] The solution provided by this invention is based on it being possible to obtain IBDV VLPs correctly assembled by means of the simultaneous expression of the viral polyprotein and the IBDV VP1 protein from two independent open reading frames (ORFs) in suitable host cells. In a particular embodiment, the expression of said ORFs is controlled by different promoters. Said IBDV VLPs are formed by auto-assembly of the IBDV VPX, VP2, VP3 and VP1 proteins, whereby they contain all the antigenically relevant protein elements present in the purified and infective IBDV virions and, for this reason, are called “whole IBDV VLPs” in this description. Given that such whole (complete) IBDV VLPs contain all the antigenically relevant protein elements present in the purified and infective virions of IBDV so as to induce an immunogenic or antigenic response, such whole IBDV VLPs can be used for therapeutic purposes, for example, in the development of vaccines, such as vaccines for protecting birds from the infection caused by IBDV or in the development of gene therapy vectors; for diagnostic purposes, etc.
[0018] The obtained results clearly show that: (i) IBDV VP3 protein, expressed in insect cells from the expression of the viral polyprotein, undergo a proteolytic processing eliminating the last 13 amino acid residues from its C-terminal end; (ii) the resulting VP3 protein (called VP3T) is incapable of forming oligomers, which produces a virtually complete blocking of the morphogenetic process inducing virtually no production of VLPs; and (iii) the association of the VP3 protein with the VP1 protein protects the first one (VP3) against the proteolytic processing.
[0019] These results have allowed for designing a new strategy or process for the efficient production of whole IBDV VLPs and which, unlike the previously described methods, have an effective morphogenesis while at the same time the presence therein of heterologous protein elements inexistent in purified viral particles is prevented. This strategy is based on the use of a gene expression vector or system allowing the coexpression of the viral polyprotein and of the VP1 protein as independent ORFs, which assures the presence of the viral polyprotein and of the IBDV VP1 protein during the assembly process of the whole IBDV VLPs. Under these conditions, the VP3 and VP1 proteins form stable complexes hindering the proteolytic degradation of VP3, assuring its proper functioning, and leading to the incorporation of VP1 in the IBDV VLPs.
[0020] In a particular embodiment, said gene expression system is based on the use of a dual recombinant baculovirus simultaneously expressing the viral polyprotein and the IBDV VP1 protein from two independent ORFs controlled by different promoters. In another particular embodiment, such whole IBDV VLPs are obtained as a result of the coinfection of host cells, such as insect cells, with two recombinant baculoviruses, one of them capable of expressing the viral polyprotein and the other one, the IBDV VP1 protein.
[0021] The vaccines obtained by using said whole IBDV VLPs have a number of advantages since it prevents the handling of highly infectious material, it prevents the potential risk of the occurrence of new IBDV mutants, and eliminates the use of a live virus on poultry farms, thus preventing the risk of spreading IBDV vaccine strains to the environment.
[0022] Consequently, one aspect of the present invention is related to a whole IBDV VLP made up by assembly of the IBDV PVX, VP2, VP3 and VP1 proteins. Said whole IBDV VLP has antigenic or immunogenic activity against the infection caused by IBDV.
[0023] A further aspect of this invention is related to a process for the production of said whole IBDV VLPs provided by this invention, based on the gene coexpression of the viral polyprotein and of the IBDV VP1 as two independent ORFs in suitable host cells. In a particular embodiment, the expression of said ORFs is controlled by different promoters.
[0024] The gene constructs, expression systems and host cells developed for the implementation of said production process of said whole IBDV VLPs, as well as their use for the production of said whole IBDV VLPs, constitute further aspects of the present invention.
[0025] Such whole IBDV VLPs have the ability to immunize animals, particularly, birds, against the avian disease caused by IBDV, as well as the ability to vectorize or incorporate into vehicles molecules of biological interest, for example, polypeptides, proteins, nucleic acids, etc. In a particular embodiment, said whole IBDV VLPs can be used in the development of vaccines to protect birds against the virus causing the avian disease known as infectious bursal disease (IBDV). Virtually any bird, preferably those avian species of economic interest, for example, chickens, turkeys, ganders, geese, pheasants, partridges, ostriches, etc., can be immunized against the infection caused by IBDV with the vaccines provided by this invention. In another particular embodiment, said whole IBDV VLPs can internally incorporate into vehicles products with biological activity, for example, nucleic acids, peptides, proteins, drugs, etc., whereby they can be used in the manufacture of gene therapy vectors.
[0026] Therefore, in a further aspect, the present invention is related to the use of said whole IBDV VLPs in the manufacture of medicaments, such as vaccines and gene therapy vectors. Said vaccines and vectors constitute further aspects of the present invention. In a particular embodiment, said vaccine is a vaccine useful for protecting birds from the infection caused by IBDV. In a specific embodiment, said birds are selected from the group formed by chickens, turkeys, ganders, geese, pheasants, partridges, ostriches, preferably chickens.
[0027] In another aspect, the invention is related to a process for the production of recombinant baculoviruses useful for the production of whole IBDV VLPs. In a particular embodiment, the recombinant obtained baculoviruses are dual, i.e., the same recombinant baculovirus is able to express in suitable host cells the viral polyprotein and the IBDV VP1 protein from two ORFs, independent and controlled by promoters of different baculoviruses. In another particular embodiment, recombinant baculoviruses are obtained which are able to express in suitable host cells the viral polyprotein from a nucleic acid sequence comprising the ORFs corresponding to the IBDV polyprotein under the control of a promoter, and recombinant baculoviruses able to express in suitable host cells the IBDV VP1 protein from a nucleic acid sequence comprising the ORF corresponding to the IBDV VP1 under the control of a promoter, the same as or different from the one controlling the expression of the viral polyprotein in said recombinant baculoviruses able to express the viral polyprotein. The resulting recombinant baculoviruses (rBVs) constitute a further aspect of the present invention. Such rBVs can be used for the production of whole IBDV VLPs.
BRIEF DESCRIPTION OF THE FIGURES
[0028] FIG. 1 shows the effect of the C-terminal deletion of the IBDV VP3 in the morphogenesis of VLPs. FIG. 1A shows a diagram which graphically represents the genes derived from IBDV expressed by the different recombinants of the vaccine virus [VT7/Poly (Poly), disclosed by Fernández-Arias et al. (Fernández-Arias, A., et al. 1998. Expression of ORF A1 of infectious bursal disease virus results in the formation of virus-like particles. J. Gen. Virol. 79:1047-1054), VT7/PolyΔ907-1012 (PolyΔ907-1012) and VT7VP3 (VP3)] used for checking the effect of the C-terminal end deletion of VP3 in the formation of IBDV VLPs in mammal cells. VT7/Poly (Poly) expresses the whole polyprotein. VT7/PolyΔ907-1012 (PolyΔ907-1012) expresses a deleted form of the polyprotein lacking the 150 C-terminal residues. VT7/VP3 (VP3) expresses the whole VP3 polyprotein. FIG. 1B illustrates the effect of the deletion of the C-terminal end of the IBDV polyprotein on the subcellular distribution of the VPX (pVP2) and VP2 proteins, and includes digital confocal microscopy images obtained from infected cells with the recombinants VT7/Poly (Poly), VT7/PolyΔ907-1012 (PolyΔ907-1012) and VT7/VP3 (VP3), respectively. The cells were fixed at 24 hours post-infection (h.p.i.) and incubated with anti- IBDV VPX/2 (anti-pVP2VP2) rabbit serum and with anti-IBDV VP3 rat serum, followed by incubation with anti-rabbit IgG goat immunoglobulin coupled to Alexa 488 (green) and with anti-rat IgG goat immunoglobulin coupled to Alexa 594 (red). FIG. 1C shows the effect of the deletion of the C-terminal end of the IBDV polyprotein on the assembly of the capsids; cell extracts infected with VT7/Poly (Poly), VT7/PolyΔ907-1012 (PolyΔ907-1012) or coinfected with VT7/PolyΔ907-1012 (PolyΔ907-1012) and VT7/VP3 (VP3) were subjected to fractioning on sucrose gradient. An aliquot of each one of the fractions was placed on an electron microscopy grid, negatively stained and viewed by means of electron microscopy. The images represent the assemblies detected in equivalent fractions of the different gradients.
[0029] FIG. 2 shows the results of a comparative analysis by means of Western blot of the IBDV VP3 protein expressed in different expression systems; cell extracts infected with IBDV, VT7/Poly and FB/Poly, respectively, were subjected to sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis using anti-IBDV VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase (HRPO: horse radish peroxidase). The signal was detected by means of ECL (Enhanced Chemioluminescence). The position of the immunoreactive bands and those of the molecular weight markers are indicated.
[0030] FIG. 3 shows the characterization of C-terminal proteolysis of the IBDV VP3 protein expressed in insect cells. FIG. 1A shows a diagram graphically representing the his-VP3 gene containing a histidine tag fused to the N-terminal end of VP3 expressed by the recombinant baculovirus FB/his-VP3 [occasionally referred to in this description as FB/his-VP3 wt (wild type)]. The sequence corresponding to the histidine tag and the first amino acid residue corresponding to VP3 (underlined) is indicated. Samples corresponding to whole H5 cell extracts (GIBCO), also identified in this description as H5 cells, infected with FB/his-VP3, or to the his-VP3 protein purified by affinity were subjected to SDS-PAGE and Western blot analysis using anti-VP3 rabbit serum ( FIG. 1B ) or anti-histidine tag (anti-his tag) ( FIG. 1C ) followed by incubation with goat immunoglobulin coupled to peroxidase. The signal was detected by means of ECL. The position of the immunoreactive bands and those of the molecular weight markers are indicated.
[0031] FIG. 4 shows the location of the proteolytic cutting site of the IBDV VP3 protein in insect cells. FIG. 1A is a diagram graphically representing the group of deleted his-VP3 proteins used in the determination of the position of the proteolytic cutting site of the IBDV VP3 protein in insect cells. FIG. 1B shows the result of a Western blot analysis of the different deleted his-VP3 proteins expressed in H5 cells and purified by immobilized metal affinity chromatography (IMAC). H5 cell culture extracts infected with each one of the recombinant baculoviruses were subjected to purification in HiTrap affinity columns (Amersham Pharmacia Biotech). The purified proteins were subjected to SDS-PAGE and Western blot analysis using anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. The signal was detected by means of ECL. The position of the immunoreactive bands and those of the molecular weight markers are indicated. The arrows indicate the position of the whole protein (F) and the one corresponding to the proteolyzed form (T).
[0032] FIG. 5 illustrates that the proteolytic processing of IBDV VP3 in insect cells causes the elimination of a peptide of 1.560 Da from the C-terminal end of his-VP3. H5 cell extracts infected with FB/his-VP3 were subjected to purification by means of IMAC and the resulting purified protein was analyzed by means of mass spectrophotometry in triplicate. FIG. 5A shows the results of one of these experiments. The presence of two polypeptides of 32.004 and 30.444 Da, respectively, was determined, which proves that the proteolytic processing produces the elimination of a peptide of 1.560 Da from the C-terminal end of his-VP3, size which fits with the molecular mass (1.576 Da) corresponding to the 13 C-terminal residues of IBDV VP3, the sequence of which is shown in FIG. 5B .
[0033] FIG. 6 shows the effect of the coexpression of IBDV VP1 on the proteolysis of his-VP3. FIG. 6A shows the detection of VP3/VP1 complexes. H5 cells were infected with FB/his-VP3 or with FBD/his-VP3-VP1. At 72 h.p.i., the cells were harvested and the corresponding extracts subjected to purification in HiTrap affinity columns (Amersham Pharmacia Biotech). Samples corresponding to total extracts (T) or to purified proteins were subjected to SDS-PAGE. The gels were subsequently stained with silver nitrate. The position of the molecular weight markers is indicated. FIG. 6B shows the results of a Western blot analysis of extracts of H5 cells infected with FB/his-VP3, FBD/his-VP3-VP1, or coinfected with FB/his-VP3 and FB/VP1, respectively. The infected cells were harvested at 72 h.p.i. and homogenized. The corresponding extracts were subjected to SDS-PAGE and Western blot analysis using anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. The signal was detected by means of ECL. The position of the molecular weight markers is indicated.
[0034] FIG. 7 shows the location of the oligomerization domain. FIG. 7A is a diagram graphically representing the group of deleted his-VP3 proteins used in the determination of the VP3 oligomerization domain position. The deleted regions are indicated with the dotted line. The name of each mutant indicates the location of eliminated amino acid remains in the sequence of the IBDV VP3 protein. FIG. 7B shows the detection of VP3 oligomers. The different his-VP3 deletion proteins, purified by HiTrap affinity columns (Amersham Pharmacia Biotech), were subjected to SDS-PAGE and Western blot analysis using anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. FIG. 1C shows the results of a Western blot analysis. The samples described in the previous paragraph ( FIG. 7B ) were subjected to non-denaturing electrophoresis followed by Western blot analysis using anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. FIG. 7D shows the detection of VP3 oligomers produced by VP3 C-terminal deletion mutants. The purified proteins were subjected to SDS-PAGE and Western blot analysis using anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. The signal was detected by means of ECL. The position of the molecular weight markers is indicated.
[0035] FIG. 8 shows the determination of the effect of the coexpression of IBDV VP1 on the proteolytic processing of IBDV VP3 and the subcellular distribution of the proteins of the capsid. FIG. 8A illustrates the detection of the IBDV VP1 and VP3 proteins accumulated in H5 cells infected with FB/Poly and FBD/Poly-VP1, respectively. Infected cells were harvested at 24, 48 and 72 h.p.i. The samples were subjected to SDS-PAGE and Western blot analysis using anti-VP3 or anti-VP1 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. The position of the molecular weight markers is indicated. The subcellular distribution of the VPX/2 (pVP2/VP2) and VP3 proteins in cells infected with FB/Poly and FBD/Poly-VP1 was analyzed by confocal microscopy ( FIG. 8B ). The cells were fixed at 60 h.p.i., and then incubated with anti-VPX rabbit serum (anti-pVP2) and anti-VP3 rat serum followed by incubation with anti-rabbit IgG goat immunoglobulin coupled to Alexa 488 (green) and with anti-rat IgG goat immunoglobulin coupled to Alexa 594 (red). The arrows indicate the position of the viroplasms formed by VPX/2 (pVP2/VP2) and VP3.
[0036] FIG. 9 illustrates the characterization of the structures formed by expression of the IBDV polyprotein in cells infected with FB/Poly-VP1. FIG. 9A shows a set of micrographs of the structures obtained in the different fractions. H5 cells were infected with FB/Poly (Poly) or with FBD/Poly-VP1 (Poly-VP1). The cells were harvested at 90 h.p.i. and the corresponding extracts were used for the purification of structures by means of sucrose gradients. After centrifugation, 6 aliquots of 2 ml were taken. One part of the aliquot was placed on a grid, negatively stained with uranyl acetate, and analyzed by means of observation in the electron microscope. Fractions #1 correspond to the bottom of the gradients. Fractions #6, which contained soluble protein and de-assembled structures, are not shown. The bar corresponding to 200 nm. FIG. 9B is a micrograph showing purified VLPs from cells infected with FBD/Poly-VP1. The image corresponds to fraction #5 of the gradient obtained from cells infected with FBD/Poly-VP1. The enlarged boxes show 2 VLPs at a larger amplification. FIG. 9C shows the characterization of the polypeptides present in fraction #5 of both gradients. An aliquot of fraction #5 of each gradient was subjected to SDS-PAGE and Western blot analysis using anti-VP1, anti-VPX (anti-pVP2/VP2) or anti-VP3 rabbit serum, followed by incubation with goat immunoglobulin coupled to peroxidase. The position of VPX (pVP2), VP2, whole VP3 (F) and proteolyzed VP3 (T) is shown.
DETAILED DESCRIPTION OF THE INVENTION
[0037] In a first aspect, the invention provides a whole empty viral capsid of the infectious bursal disease virus (IBDV), hereinafter whole IBDV VLP (whole VLPs in plural form) of the invention, characterized in that it contains all the proteins present in purified and infective IBDV virions, specifically the IBDV VPX, VP2, VP3 and VP1 proteins.
[0038] The term “IBDV”, as it is used in the present invention, refers to the different IBDV strains belonging to any of the serotypes (1 or 2) known [by way of illustration, see the review carried out by van den Berg, T. P., Eterradossi, N., Toquin, D., Meulemans, G., in Rev Sci Tech 2000 19:509-43].
[0039] The terms “viral polyprotein” or “IBDV polyprotein” are generally used in this description and refer to the product resulting from the expression of the A segment of the IBDV genome the proteolytic processing of which gives rise to the VPX (pVP2), VP3 and VP4 proteins, and include the different forms of the polyproteins representative of any of the mentioned IBDV strains [NCBI protein databank], according to the definition carried out by Sánchez and Rodríguez (1999) (Sánchez, A. B. and Rodríguez, J. F. Proteolytic processing in infectious bursal disease virus: identification of the polyprotein cleavage sites by site-directed mutagenesis. Virology. 1999 Sep. 15; 262(1):190-199), as well as proteins substantially homologous to said IBDV polyprotein, i.e., proteins the amino acid sequences of which have a degree of identity regarding said IBDV polyprotein of at least 60%, preferably of at least 80%, more preferably of at least 90% and even more preferably of at least 95%.
[0040] The term “IBDV VP1 protein” refers to the product resulting from the expression of segment B of the IBDV genome and includes the different forms of the VP1 proteins representative of any of the mentioned IBDV strains [NCBI protein databank], according to the definition carried out by Lombardo, E., et al. 1999. VP1, The putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83) as well as proteins substantially homologous to said IBDV VP1 protein, i.e., proteins the amino acid sequences of which have a degree of identity regarding said IBDV VP1 of at least 60%, preferably of at least 80%, more preferably of at least 90% and even more preferably of at least 95%.
[0041] The IBDV VPX (pVP2), VP2 and VP3 proteins present in the whole IBDV VLPs of the invention can be any of the VPX, VP2 and VP3 proteins representative of any IBDV strain obtained by proteolytic processing of the viral polyprotein, for example the IBDV Soroa strain VPX, VP2 and VP3 proteins [NCBI, access number AAD30136].
[0042] The IBDV VP1 protein present in the whole IBDV VLPs of the invention can be any VP1 protein representative of any IBDV strain, for example, the whole length, Soroa strain VP1 protein, the amino acid sequence of which is shown in SEQ. ID. NO: 2.
[0043] In a particular embodiment, the whole IBDV VLPs of the invention have a diameter of 65-70 nm and a polygonal contour indistinguishable from the IBDV virions.
[0044] The whole IBDV VLPs of the invention can be obtained by means of the simultaneous expression of said IBDV viral polyprotein and VP1 protein in suitable host cells. Said suitable host cells are cells containing the encoding nucleotide sequence of the IBDV polyprotein under the control of a suitable promoter and the encoding nucleotide sequence of the IBDV VP1 protein under the control of another suitable promoter, either in a single gene construct or in two different gene constructs. In a particular embodiment, said suitable host cells are cells that are transformed, transfected or infected with a suitable expression system, such as (1) an expression system comprising a gene construct, in which such gene construct comprises the nucleotide sequence encoding for the IBDV polyprotein under the control of a promoter and the encoding nucleotide sequence of the IBDV VP1 protein under the control of another promoter different from the one which is operatively bound to the nucleotide sequence encoding the viral polyprotein, or, alternatively, (2) an expression system comprising a first gene construct comprising the nucleotide sequence encoding for the IBDV polyprotein, and a second gene construct comprising the nucleotide sequence encoding for the IBDV VP1 protein, each one of them under the control of a suitable promoter. In a particular embodiment, said host cell is an insect cell and said promoters are baculovirus promoters.
[0045] Therefore, in another aspect, the invention is related to a gene construct comprising the nucleotide sequence encoding for said IBDV polyprotein and the nucleotide sequence encoding for said IBDV VP1 protein, in the form of two independent ORFs, the expression of which is controlled by respective different promoters controlling the gene expression of each one of said IBDV viral polyprotein and VP1 protein. Therefore, the invention provides a gene construct comprising (i) a nucleotide sequence comprising the open reading frames corresponding to the polyprotein of the infectious bursal disease virus (IBDV) operatively bound to a nucleotide sequence comprising a first promoter and (ii) a nucleotide sequence comprising the open reading frame corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter, in which such first promoter is different from such second promoter. The use of such different promoters allows the independent and simultaneous control of the gene expression of such IBDV polyprotein and VP1 protein.
[0046] A feature of the gene construct provided by this invention is that it comprises the nucleotide sequences encoding for all the protein elements present in the purified and infective IBDV virions, specifically, the VPX, VP2, VP3 and VP1 proteins.
[0047] As it is used in this description, the term “ORFs (or open reading frames) corresponding to the IBDV polyprotein” or “ORF (open reading frame) corresponding to the IBDV VP1 protein” includes, in addition to the nucleotide sequences of said ORFs, other ORFs analogous to the same encoding sequences of the IBDV viral polyprotein and of the IBDV VP1. The term “analogous”, as it is used herein, intends to include any nucleotide sequence which can be isolated or constructed on the base of the encoding nucleotide sequence of the viral polyprotein and the IBDV VP1, for example, by means of the introduction of conservative or non-conservative nucleotide replacements, including the insertion of one or more nucleotides, the addition of one or more nucleotides at any end of the molecule, or the deletion of one or more nucleotides at any end or inside of the sequence. Generally, a nucleotide sequence analogous to another nucleotide sequence is substantially homologous to said nucleotide sequence. In the sense used in this description, the expression “substantially homologous” means that the nucleotide sequences in question have a degree of identity, at the nucleotide level, of at least 60%, advantageously of at least 70%, preferably of at least 80%, more preferably of at least 85%, even more preferably of at least 90%, and yet even more preferably of at least 95%.
[0048] The promoters which can be used in the implementation of the present invention generally comprise a nucleic acid sequence to which the RNA polymerase is bound so as to begin the mRNA transcription and to express said ORFs corresponding to the viral polyprotein and to the IBDV VP1 protein in suitable host cells. Although virtually any promoter meeting these conditions can be used to implement the present invention, for example, promoters of a viral, bacterial, yeast, animal, plant origin, etc., in a particular embodiment such promoters are viral promoters, for example, baculovirus promoters.
[0049] The expression of each one of said nucleotide sequence encoding for said viral polyprotein and IBDV VP1 protein, in the form of two independent ORFs, is controlled by respective different promoters controlling the gene expression of each one of such proteins. In a particular embodiment, the gene expression of such an viral polyprotein and IBDV VP1 protein is carried out in insect cells infected or coinfected with recombinant baculoviruses (rBVs) containing the encoding nucleotide sequences of said proteins, either in a single rBV (dual rBV) or in two rBVs (in which case one of such rBVs contains the encoding sequence of the IBDV polyprotein and the other one, the encoding sequence of the IBDV VP1 protein) under the control of baculovirus promoters.
[0050] Virtually any baculovirus promoter can be used as long as it is able to effectively control the expression of the encoding sequence to which it is operatively bound. By way of illustration, the first baculovirus promoter can be the promoter of the p10 protein of the baculovirus Autographa californica nucleopolyhedrovirus (AcMNV), the promoter of the polyhedrin of the AcMNPV baculovirus, etc. and the second baculovirus promoter can be the promoter of the p10 protein of AcMNPV and the promoter of the AcMNPV polyhedrin. More specifically, in a particular embodiment, the first baculovirus promoter is the promoter of the p10 protein of AcMNPV and the second baculovirus promoter is the promoter of the AcMNPV polyhedrin, whereas in another particular embodiment, the first baculovirus promoter is the promoter of the AcMNPV polyhedrin and the second baculovirus promoter is the promoter of the protein 10 of AcMNPV.
[0051] In a particular embodiment, the gene construct provided by this invention comprises:
(i) a nucleotide sequence comprising the open reading frames corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence comprising a first promoter of a baculovirus, and (ii) a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter of a baculovirus,
wherein said first and second baculovirus promoters are different.
[0054] The use of different baculovirus promoters allows for the independent and simultaneous control of the gene expression of said IBDV polyprotein VP1 protein in insect cells.
[0055] In a specific embodiment, the gene construct provided by this invention comprises the encoding sequence of the IBDV polyprotein under the control of a first baculovirus promoter and the encoding sequence of the IBDV VP1 protein under the control of a second baculovirus promoter, different from the first one, such as the gene construct referred to as “Poly-VP1” in this description, comprising the nucleotide sequence identified as SEQ. ID. NO: 1; the Poly-VP1 gene construct contains the encoding sequence of the IBDV polyprotein under the control of the promoter of the AcMNV polyhedrin and the encoding sequence of the IBDV VP1 protein under the control of the promoter of the AcMNV p10 protein.
[0056] In another aspect, the invention provides an expression vector or system selected from:
a) an expression system comprising a gene construct provided by this invention, operatively bound to transcription, and optionally translation, control elements, wherein such gene construct includes (i) a nucleotide sequence comprising the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence comprising a first promoter and (ii) a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter, wherein the first promoter is different from the second promoter; and b) an expression system including (1) a first gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the first gene construct comprises a nucleotide sequence comprising the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence including a first promoter, and (2) a second gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the second gene construct includes a nucleotide sequence including the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter.
[0059] In the second case [b)], the first promoter and the second promoter, as they are in different gene constructs, can be equal to or different from one another.
[0060] The features of the ORFs corresponding to the IBDV polyprotein and to the IBDV VP1 protein have previously been defined in relation to the gene construct provided by this invention. The promoters which can be used in the expression system provided by this invention have been previously defined in relation to the gene construct provided by this invention. By way of illustration, such promoters can be promoters of a viral, bacterial, yeast, animal, plant origin, etc.
[0061] In a particular embodiment, the expression system provided by this invention comprises a gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the gene construct includes (i) a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence including a first baculovirus promoter, such as, for example, the promoter of the AcMNV p10 protein or the promoter of the AcMNV polyhedrin, and (ii) a nucleotide sequence including the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence including a second baculovirus promoter, such as, for example, the promoter of the AcMNV p10 protein or the promoter of the AcMNV polyhedrin, wherein the first baculovirus promoter is different from the second baculovirus promoter.
[0062] In another particular embodiment, the expression system provided by this invention includes (1) a first gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the first gene construct includes a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence comprising a first baculovirus promoter, such as, for example, the promoter of the AcMNV p10 protein or the promoter of the AcMNV polyhedrin, and (2) a second gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the second gene construct comprises a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence including a second baculovirus promoter, such as, for example, the promoter of the AcMNV p10 protein or the promoter of the AcMNV polyhedrin. In this particular embodiment, the first baculovirus promoter and the second baculovirus promoter, as they are in different gene constructs, can be equal to or different from one another.
[0063] The transcription, and optionally translation, control elements present in the expression system provided by this invention include the necessary or suitable sequences for the transcription and its suitable control in time and place, for example, beginning and termination signals, cleavage sites, polyadenylation signals, replication origin, transcriptional activators (enhancers), transcriptional silencers (silencers), etc.
[0064] Virtually any suitable expression system or vector can be used in the generation of the expression system provided by this invention depending on the conditions and requirements of each specific case. By way of illustration, said suitable expression systems or vectors can be plasmids, bacmids, yeast artificial chromosomes (YACs), bacteria artificial chromosomes (BACs), bacteriophage P1-based artificial chromosomes (PACs), cosmids, viruses, which can further have, if so desired, an origin of heterologous replications, for example, bacterial, so that it may be amplified in bacteria or yeasts, as well as a marker usable for selecting the transfected cells, etc., preferably plasmids, bacmids or viruses.
[0065] These expression systems or vectors can be obtained by conventional methods known by persons skilled in the art [Sambrook, J., Fritsch, E. F., and Maniatis, T. (1989). Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbor Laboratory] and form part of the present invention. In a particular embodiment, the expression system or vector is a plasmid, such as the plasmid referred to as pFBD/Poly-VP1 in this description, or a bacmid, such as the recombinant bacmid referred to as Bac/pFBD/Poly-VP1 in this description, which contain the previously defined gene construct Poly-VP1, or a virus, such as the recombinant baculovirus (rBV) referred to as FBD/Poly-VP1 in this description, which contains the gene construct Poly-VP1 and expresses during its replication cycle both proteins (polyprotein and IBDV VP1 protein) simultaneously in insect cells, or the rBVs expressing the IBDV polyprotein and the IBDV VP1 protein, separately and simultaneously, when coinfecting insect cells, whole IBDV VLPs being obtained.
[0066] In another aspect, the invention provides a host cell containing the encoding nucleotide sequence of the IBDV polyprotein and the encoding nucleotide sequence of the IBDV VP1 protein, each one of them under the control of a suitable promoter allowing the simultaneous and independent control of said IBDV polyprotein and VP1 protein, either in a single gene construct (in which case the promoters bound to each one of said encoding sequences would be different from one another), or in two different gene constructs. Therefore, said host cell can contain either a gene construct provided by this invention or an expression system provided by this invention.
[0067] The host cell provided by this invention can be a host cell transformed, transfected or infected with an expression system provided by this invention.
[0068] In a particular embodiment, the host cell provided by this invention is a host cell transformed, transfected or infected with an expression system provided by this invention comprising a gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the gene construct includes (i) a nucleotide sequence including the ORFs corresponding to said IBDV polyprotein operatively bound to a nucleotide sequence comprising a first promoter and (ii) a nucleotide sequence comprising the open reading frame corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter, wherein the first promoter is different from the second promoter.
[0069] Alternatively, in another particular embodiment, the host cell is a host cell transformed, transfected or infected with an expression system provided by this invention comprising (1) a first gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the first gene construct comprises a nucleotide sequence comprising the ORFs corresponding to said IBDV polyprotein operatively bound to a nucleotide sequence including a first promoter, and (2) a second gene construct, operatively bound to transcription, and optionally translation, control elements, wherein the second gene construct comprises a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter; in this particular embodiment, the first promoter and the second promoter, as they are in different gene constructs, can be equal to or different from one another.
[0070] Although in any of the previously mentioned embodiments, virtually any promoter could be used, it is preferred in practice that such promoters are useful in bacteria, yeasts, viruses, animal cells, for example, in mammal cells, bird cells, insect cells, etc.; in a particular embodiment, the promoters are baculovirus promoters, such as, for example, the promoter of the AcMNV polyhedrin or the promoter of the AcMNV p10 protein.
[0071] Virtually any host cell susceptible to being transformed, transfected or infected by an expression system provided by this invention can be used, for example, bacteria, mammal cells, bird cells, insect cells, etc.
[0072] In a particular embodiment, the host cell is a bacteria transformed with an expression system provided by this invention including a gene construct provided by this invention comprising (i) a nucleotide sequence comprising the ORFs corresponding to the IBDV polyprotein and (ii) a nucleotide sequence comprising the ORFs corresponding to the IBDV VP1 protein, each one of them operatively bound to a different promoter, such as the gene construct identified as Poly-VP1. A culture of Escherichia coli bacteria strain DH5, transformed with such gene construct Poly-VP1, and identified as DH5-pFBD/Poly-VP1 has been deposited in the Spanish Type Culture Collection (hereinafter, CECT) with deposit number CECT 5777.
[0073] Alternatively, the host cell is an insect cell. Insect cells are suitable when the expression system comprises one or more rBVs. The use of rBVs is advantageous due to biosafety issues related to the host range of the baculoviruses, incapable of replicating in other cell types which are not insect cells.
[0074] Therefore, in a particular embodiment, the invention provides a host cell, such as an insect cell, infected with an expression system provided by this invention, such as a rBV, comprising a gene construct provided by this invention including (i) a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein and (ii) a nucleotide sequence including the ORF corresponding to the IBDV VP1 protein, each one of them operatively bound to a different baculovirus promoter, such as the gene construct identified as Poly-VP1.
[0075] In another particular embodiment, the invention provides host cell, such as an insect cell, coinfected with an expression system including (1) a first rBV comprising a gene construct comprising the ORFs corresponding to the IBDV polyprotein and (2) a second rBV comprising a gene construct comprising the nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein, each one of the encoding sequences being operatively bound to a baculovirus promoter, equal to or different from one another.
[0076] In another aspect, the invention provides a process for producing whole IBDV VLPs of the invention including culturing a host cell provided by this invention containing a nucleotide sequence comprising the ORFs corresponding to said IBDV polyprotein and a nucleotide sequence comprising the ORF corresponding to said IBDV VP1 protein, either in a single gene construct or in two different gene constructs, and simultaneously expressing said viral polyprotein and IBDV VP1 protein, and if so desired, recovering said whole IBDV VLPs of the invention.
[0077] In a particular embodiment, the host cell provided by this invention is a cell transformed, transfected or infected with a suitable expression system provided by this invention, such as an expression system comprising a gene construct provided by this invention, wherein such gene construct comprises (i) a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence including a first promoter and (ii) a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence comprising a second promoter, wherein either the first promoter is different from the second promoter; or alternatively, with an expression system provided by this invention including (1) a first gene construct comprising a nucleotide sequence comprising the ORFs corresponding to the IBDV polyprotein and (2) a second gene construct comprising a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein, each one of the nucleotide sequences comprising the ORFS corresponding to the viral polyprotein and to the IBDV VP1 protein being under the control of respective nucleotide sequences including respective promoters, equal to or different from one another.
[0078] Such process therefore includes the simultaneous gene coexpression of the viral polyprotein and IBDV VP1 protein as two independent ORFs. After the simultaneous expression of the viral polyprotein and VP1 protein in such cells, the polyprotein is proteolytically processed and the resulting proteins are assembled and form the whole IBDV VLPs of the invention, made up of VPX, VP2, VP3 and VP1, which can be isolated or withdrawn from the medium and, if desired, purified. The isolation or purification of such whole IBDV VLPs of the invention can be carried out by means of conventional methods, for example, by means of fractioning on sucrose gradients.
[0079] Although the host cell to culture can be any of those previously defined, in a particular embodiment, the host cell is an insect cell.
[0080] Therefore, in a specific embodiment, the simultaneous gene coexpression of the viral polyprotein and of the IBDV VP1 protein in a suitable host cell, such as an insect cell, is carried out by means of the use of a dual rBV allowing the simultaneous expression of such proteins from two independent ORFs, each one of them under the control of a different baculovirus promoter able to simultaneously and independently control the expression of such proteins in insect cells. In this case, the production of the whole IBDV VLPs of the invention can be carried out by means of a process including, first, the obtaining of a gene expression system made up of a dual rBV containing a gene construct simultaneously including the ORFS corresponding to the viral polyprotein and IBDV VP1 protein, such as the rBV referred to as FBD/Poly-VP1 in this description, or else, alternatively, the obtaining of a rBV containing a gene construct including the ORF corresponding to the IBDV polyprotein and the obtaining of another rBV containing a gene construct comprising the ORF corresponding to the IBDV VP1 protein, followed by the infection of insect cells with the expression system based on such rVB(s), expression of the recombinant proteins and, if so desired, isolation of- the formed whole IBDV VLPs of the invention, and optionally, subsequent purification of the whole IBDV VLPs of the invention.
[0081] More specifically, in a particular embodiment, the process for obtaining whole VLPs of the invention is characterized in that the host cell is an insect cell and includes the steps of:
a) preparing an expression system provided by this invention made up of (1) a first recombinant baculovirus comprising a gene construct comprising a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein operatively bound to a baculovirus promoter, such gene construct being operatively bound to transcription, and optionally translation, control elements, and of (2) a second recombinant baculovirus comprising a gene construct including a nucleotide sequence including the ORF corresponding to the IBDV VP1 protein operatively bound to a promoter of a baculovirus, such gene construct being operatively bound to several transcription, and optionally translation, control elements; b) infecting insect cells with said expression system prepared in step a); c) culturing the infected insect cells obtained in step b) under conditions allowing the expression of the recombinant proteins and their assembly so as to form whole IBDV VLPs; and d) if so desired, isolating and optionally purifying such whole IBDV VLPs.
[0086] Likewise, in another particular embodiment, the process for obtaining whole VLPs of the invention is characterized in that the host cell is an insect cell and includes the steps of:
a) preparing an expression system made up of a dual recombinant baculovirus including a gene construct including (i) a nucleotide sequence including the ORFs corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence including a first baculovirus promoter, such gene construct being operatively bound to transcription, and optionally translation, control elements, and (ii) a nucleotide sequence comprising the ORF corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence including a second baculovirus promoter, such gene construct being operatively bound to transcription, and optionally translation, control elements, wherein the baculovirus promoter is different from the second baculovirus promoter; b) infecting insect cells with said expression system prepared in step a); c) culturing the infected insect cells obtained in step b) under conditions allowing the expression of the recombinant proteins and their assembly so as to form whole IBDV VLPs; and d) if so desired, isolating and optionally purifying the whole IBDV VLPs.
[0091] The construct of a dual rBV simultaneously allowing expression of the IBDV polyprotein and of the IBDV VP3 protein can be carried out by a person skilled in the art based on that herein described and on the state of the art on this technology (Cold Spring Harbor, N.Y.; Leusch, M. S., Lee, S. C., Olins, P. O. 1995. A novel host-vector system for direct selection of recombinant baculoviruses (bacmids) in Escherichia coli . Gene 160:191-4; Luckow, V. A., Lee, S. C., Barry, G. F., Olins, P. O. 1993. Efficient generation of infectious recombinant baculoviruses by site-specific transposon-mediated insertion of foreign genes into a baculovirus genome propagated in Escherichia coli . J. Virol. 67:4566-79). A rBV containing the gene construct comprising the ORFs corresponding to the IBDV polyprotein and a rBV containing a gene construct including the ORF corresponding to the IBDV VP1 protein can be similarly obtained.
[0092] In relation to this, the invention provides a process for obtaining a dual rBV allowing the simultaneous expression of the IBDV polyprotein and of IBDV VP1 protein from two independent ORFs and each one of them controlled by a different baculovirus promoter, in insect cells, including:
a) constructing a plasmid carrier of a gene construct containing (i) a nucleotide sequence including the open reading frames corresponding to the IBDV polyprotein operatively bound to a nucleotide sequence including a first promoter of a baculovirus, and (ii) a nucleotide sequence including the open reading frame corresponding to the IBDV VP1 protein operatively bound to a nucleotide sequence including a second promoter of a baculovirus, wherein the first baculovirus promoter is different from the second baculovirus promoter and they allow the simultaneous control of the gene expression of the polyprotein and IBDV VP1 protein; b) obtaining a recombinant bacmid, simultaneously allowing the expression during its replicative cycle of the polyprotein and the IBDV VP1 protein under the transcriptional control of the baculovirus promoters, by means of the transformation of competent bacteria with the plasmid obtained in a); and c) obtaining a dual recombinant baculovirus, allowing the simultaneous expression of the open reading frames corresponding to the polyprotein and the IBDV VP1 protein under the transcriptional control of the baculovirus promoters, by means of the transformation of insect cells with the recombinant bacmid of b).
[0096] As used in this description, the term “competent bacteria” refers to bacteria which can contain the genome of a baculovirus, for example, AcMNV, optionally genetically modified, allowing the recombination with donor plasmids.
[0097] In a particular embodiment, the process of obtaining dual rBVs is characterized in that:
the first baculovirus promoter sequence comprises the promoter of the AcMNV p10 protein and the second baculovirus promoter sequence includes the promoter of the AcMNPV polyhedrin, or vice versa; the plasmid obtained in a) is the one identified as pFBD/Poly-VP1 in this description; the competent bacteria transformed in b) are Escherichia coli DH10Bac; the recombinant bacmid obtained in b) is the one identified as Bac/pFBD/Poly-VP1 in this description; and the dual rBV obtained is the one identified as FBD/Poly-VP1.
[0103] The dual rBV thus obtained can be used, if so desired, to obtain whole IBDV VLPs of the invention. To that end, insect cells are infected with the dual rBV. Virtually any insect cell can be used; however, in a particular embodiment, the insect cells are H5 cells or Spodoptera frugiperda Sf9 cells.
[0104] Alternatively, as previously mentioned, whole VLPs of the invention can be obtained by means of the combined infection (coinfection) of insect cells with a rBV allowing expression of the IBDV polyprotein in insect cells and with a rBV allowing expression of the IBDV VP1 protein in insect cells. Such rBVs can be obtained as previously described. Virtually any insect cell can be used; however, in a particular embodiment, the insect cells are H5 cells or Spodoptera frugiperda Sf9 cells.
[0105] Accordingly, in another aspect, the invention is related to a process for the production of rBVs useful for the production of whole IBDV VLPs. In a particular embodiment, the recombinant baculoviruses obtained are dual, i.e., the same recombinant baculovirus is able to express in suitable host cells the viral polyprotein and the IBDV VP1 protein from two independent ORFs and controlled by different baculovirus promoters. The simultaneous expression in the same host cell of the viral polyprotein and IBDV VP1 protein allows the formation of whole IBDV VLPs. In another particular embodiment, recombinant baculoviruses are obtained which are able to express in suitable host cells the viral polyprotein from a nucleic acid sequence comprising the ORFs corresponding to the IBDV polyprotein under the control of a baculovirus promoter and several recombinant baculoviruses able to express in suitable host cells the IBDV VP1 protein from a nucleic acid sequence comprising the ORF corresponding to the VP1 of IBDV under the control of a promoter that is equal to or different from the one regulating the expression of the viral polyprotein in the recombinant baculoviruses able to express the viral polyprotein. The combined infection (coinfection) of suitable host cells, such as insect cells, with the recombinant baculoviruses able to express the viral polyprotein and with the recombinant baculoviruses able to express the IBDV VP1 protein, allows for the simultaneous expression in the coinfected cells of the viral polyprotein and of the IBDV VP1 protein, which allows for the formation of whole IBDV VLPs. The resulting recombinant baculoviruses constitute a further aspect of the present invention.
[0106] In another aspect, the invention is related to the use of the gene expression system provided by this invention for the production of whole IBDV VLPs of the invention, which constitute a further aspect of this invention.
[0107] The whole IBDV VLPs of the invention can be used to immunize animals, particularly birds, per se or as vectors or vehicles of molecules with biological activity, for example, polypeptides, proteins, nucleic acids, drugs, etc., whereby they can be used for therapeutic or diagnostic purposes. In a particular embodiment, the molecules with biological activity include antigens or immune response inducers in animals or humans to whom they are supplied, or drugs which can be released in their specific action site, or nucleic acid sequences, all being useful in gene therapy and intended for being introduced inside the suitable cells.
[0108] Therefore, in another aspect, the invention is related to the use of the whole IBDV VLPs of the invention in the manufacture of medicaments such as vaccines, gene therapy vectors (delivery systems), etc. In a particular embodiment, the medicament is a vaccine intended for conferring protection to animals, particularly birds, against the infectious bursal disease virus (IBDV). In another particular embodiment, the medicament is a gene therapy vector.
[0109] In another aspect, the invention provides a vaccine comprising a therapeutically effective amount of whole IBDV VLPs of the invention, optionally together with one or more pharmaceutically acceptable adjuvants and/or vehicles. Such vaccine is useful for protecting animals, particularly birds, against the infectious bursal disease virus (IBDV). In a particular embodiment, such birds are selected from the group formed by chickens, turkeys, geese, ganders, pheasants, partridges and ostriches. In a preferred embodiment, the vaccine provided by this invention is a vaccine useful for protecting chickens from the infection caused by IBDV.
[0110] In the sense used in this description, the expression “therapeutically effective amount” refers to the amount of whole IBDV VLPs of the invention calculated for producing the desired effect and will generally be determined, among others, by the characteristics of the whole IBDV VLPs of the invention and the immunization effect to be achieved.
[0111] The pharmaceutically acceptable adjuvants and vehicles which can be used in such vaccines are those adjuvants and vehicles known by the persons skilled in the art and normally used in the manufacture of vaccines.
[0112] In a particular embodiment, the vaccine is prepared in form of an aqueous solution or suspension in a pharmaceutically acceptable diluent, such as saline solution, phosphate-buffered saline solution (PBS), or any other pharmaceutically acceptable diluent.
[0113] The vaccine provided by this invention can be administered by any suitable administration route that results in a protective immune response against the heterologous sequence or epitope used, to which end the vaccine will be formulated in the dosage form suited to the chosen administration route. In a particular embodiment, the administration of the vaccine provided by this invention is carried out parenterally, for example, intraperitoneally, subcutaneously, etc.
[0114] The following Examples illustrate the invention and should not be considered limiting of the scope thereof. Example 1 clearly shows that the deletion of the C-terminal end of the IBDV VP3 protein hinders formation of IBDV VLPs, whereas Example 2 describes the generation of a recombinant baculovirus coexpressing the A1 and B1 open reading frames of the IBDV genome, and Example 3 illustrates obtaining whole IBDV VLPs from H5 cells infected with the recombinant baculovirus FBD/Poly-VP1. The materials and methods described below were used to implement the Examples.
Materials and Methods
[0115] Cells and viruses. The recombinant viruses VT7/VP3, VT7/PolyΔ907-1012, FB/Poly, FB/his-VP3 (wt), FB/his-VP3Δ253-257, FB/his-VP3Δ1-25, FB/his-VP3Δ26-52, FB/his-VP3Δ53-77, FB/his-VP3Δ78-100, FB/his-VP3Δ101-124, FB/his-VP3Δ125-150, FB/his-VP3Δ151-175, FB/his-VP3Δ176-200, FB/his-VP3Δ201-224 and FB/his-VP3Δ216-257 were disclosed previously (Fernández-Arias A et al. 1997. The major antigenic protein of infectious bursal disease virus, VP2, is an apoptotic inducer. J. Virol. 71:8014-8; Kadono-Okuda, K., et al. 1995. Baculovirus-mediated production of the human growth hormone in larvae of the silkworm, Bombyx mori. Biochem. Biophys. Res. Commun. 213:389-96; Kochan, G., et al. Characterization of the RNA binding activity of VP3, a major structural protein of IBDV. 2003. Archives of Virology 148:723-744; Martínez-Torrecuadrada, J. L., et al. 2000. Different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. Virology. 278:322-31).
[0116] The expression experiments were carried out with BSC-1 cells (American Type Culture Collection, ATCC; Catalogue CCL26), H5 [HighFive™ (GIBCO)] and Sf9 cells (GIBCO). The BSC-1 cells were cultured in Eagle modified Dulbecco medium supplemented with 10% fetal bovine serum. The H5 and Sf9 cells were cultured in TC-100 medium (GIBCO) supplemented with 10% fetal bovine serum. The viruses were amplified and titrated following previously disclosed protocols (Lombardo, E., et al. 2000. VP5, the nonstructural polypeptide of infectious bursal disease virus, accumulates within the host plasma membrane and induces cell lysis. Virology. 277:345-57; Martínez-Torrecuadrada, J. L., et al. 2000. Different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. Virology. 278:322-31).
[0117] The isolate of IBDV used was IBDV Soroa strain.
[0118] Generation of recombinant baculoviruses. The previously disclosed plasmid pFB/his-VP3 was used as a mold in the generation, by means of polymerase chain reaction (PCR), of the DNA fragments used in the construction of the plasmid vectors needed for the construction of the recombinant baculoviruses FB/his-VP3Δ248-257, FB/his-VP3Δ243-257, FB/his-VP3Δ238-257, FB/his-VP3Δ233-257, and FB/his-VP3Δ228-257. The PCR reactions were carried out using a common 5′ primer (SEQ. ID. NO: 4) and 3′ primer specific for each mutant (Table 1).
TABLE 1 Generation of deletion mutants of the terminal carboxy end of His-VP3 Mutant Sequence His-VP3Δ248-257 SEQ. ID. NO: 5 His-VP3Δ243-257 SEQ. ID. NO: 6 His-VP3Δ238-257 SEQ. ID. NO: 7 His-VP3Δ233-257 SEQ. ID. NO: 8 His-VP3Δ228-257 SEQ. ID. NO: 9
[0119] After the PCR reactions, the corresponding DNA fragments were purified and digested with the restriction enzymes ApaI and KpnI and ligated to the plasmid pFB/his-VP3 (Kochan, G., et al. 2003. Characterization of the RNA binding activity of VP3, a major structural protein of IBDV. Archives of Virology 148:723-744) previously digested with the same enzymes. The plasmid series generically referred to as pFB/his-ΔVP3 (pFB/his-VP3Δn-n′ more specifically, wherein n and n′ indicate the deleted region borders) containing deletions in the 5′ end of the encoding region of VP3, were thus generated.
[0120] The construction of the plasmid vectors required for the generation of the recombinant baculoviruses FB/PolyΔ1008-1012, FB/PolyΔ1003-1012 and FB/PolyΔ998-1012 was carried out by means of the substitution of the Xba I fragment (343 base pairs) with its homologs, containing the desired deletions, deriving from the plasmids FB/his-VP3Δ233-257, FB/his-VP3Δ248-257, and FB/his-VP3Δ243-257, respectively.
[0121] The construction of the plasmid vector pFB/VP1 was carried out by means of cloning a DNA fragment, which contains the open reading frame of the gene of the IBDV VP1 protein, from the plasmid pBSKVP1 (Lombardo E et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83) by means of digestion of the plasmid with the restriction enzyme ClaI, followed by treatment with the Klenow fragment of DNA polymerase I and subsequent treatment with the enzyme NotI. This fragment was subcloned into the vector pFastBac1 (Invitrogen) previously digested with the restriction enzymes Stul and NotI. The resulting plasmid was called pFB/VP1.
[0122] The plasmid vectors pFBD/his-VP3-VP1 and pFBD/Poly-VP1 were constructed by means of the insertion of the open reading frames of the genes of the VP3 and VP1 proteins in the vector pFastBacDual (Invitrogen). pFBD/VP1 was generated by means of the insertion of a fragment containing the open reading frame of VP1 obtained by means of digestion with the enzyme NotI, followed by treatment with the Klenow fragment of DNA polymerase I and subsequent treatment with the enzyme XhoI, in the vector pFastBacDual (Invitrogen) previously digested with the enzymes XhoI and PvuII. Next, the plasmid pFB/his-VP3 (Kochan, G., et al. 2003. Characterization of the RNA binding activity of VP3, a major structural protein of IBDV. Archives of Virology 148:723-744) was digested with the enzymes NotI and RsrII, and the resulting fragment containing the open reading frame of his-VP3 was inserted in the plasmid pFBD/VP1 previously digested with the enzymes NotI and RsrII. The resulting plasmid was called pFBD/his-VP3-VP1. Similarly, the open reading frame corresponding to the IBDV polyprotein was isolated from the plasmid pCIneoPoly (Maraver, A., et al. Identification and molecular characterization of the RNA polymerase-binding motif of the inner capsid protein VP3 of infectious bursal disease virus. J. Virol. 77:2459-2468) by means of digestion with the enzymes EcoRI and NotI. The corresponding DNA fragment was cloned into the plasmid pFBD/VP1 previously digested with the enzymes EcoRI and NotI, giving rise to the vector referred to as pFBD/Poly-VP1.
[0123] The recombinant baculoviruses described above were generated using the Bac-to-Bac system, following the protocols described by the manufacturer (Invitrogen).
[0124] Purification by means of sucrose gradients and characterization of the structures derived from the expression of the IBDV polyprotein. BSC-1 or H5 cells were infected with the described vaccine viruses or recombinant baculoviruses. The infected cells were harvested, lysed and processed as described above (Lombardo, E., et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83; Castón, J. R., et al. 2001. C terminus of infectious bursal disease virus major capsid protein VP2 is involved in definition of the number for capsid assembly. J. Virol. 75:10815-28).
[0125] Electron microscopy. Aliquots of 5 μl of the different fractions of the analyzed sucrose gradients were placed in electron microscopy grids. The samples thus prepared were negatively stained with a 2% uranyl acetate solution. The micrographs were obtained with a Jeol 1200 EXII microscope operating at 100 kV with magnifications of 20,000 or 40,000×.
[0126] Purification of his-VP3 fusion proteins and derivatives by means of immobilized metal affinity chromatography (IMAC). H5 or Sf9 cells infected with the different recombinant viruses described were harvested at 72 h.p.i. Alter washing twice in phosphate buffered saline (PBS), the cells were resuspended in lysis buffer (Tris-HCI 50 mM, pH 8.0; NaCl 500 mM) supplemented with protease inhibitors (Complete Mini, Roche) and kept on ice for 20 minutes. Then the samples were subjected to centrifugation at 13,000×g for 10 minutes at 4° C. The corresponding supernatants were subjected to purification by means of IMAC using a resin bound to cobalt (Talon, Clontech Laboratories, Inc., Palo Alto, Calif.) following the manufacturer instructions.
[0127] Electrophoresis and Western blot. The protein samples were resuspended in Laemmli buffer (King J & Laemmli UK. 1973. Bacteriophage T4 tail assembly: structural proteins and their genetic identification. J Mol Biol. 1973 Apr. 5;75(2):315-37) and subjected to heating at 100° C. for 5 minutes. The electrophoreses were carried out in 11% polyacrylamide gels. Then the proteins were transferred to nitrocellulose membranes by means of electroblotting. Prior to the incubation with specific antisera, the membranes were blocked by means of incubation for 1 hour at room temperature, with 5% powdered milk diluted in PBS.
[0128] Immunofluorescence (IF) and confocal microscopy (CLSM). BSC-1 or H5 cells were grown on slide covers and infected with the recombinant baculoviruses or vaccine viruses. At the post-infection times indicated, the cells were washed two times with PBS and fixed with methanol at −20° C. for 10 minutes. After the fixing, the slide covers were air dried, blocked in a 20% solution of recently born calf serum in PBS 45 minutes at room temperature and incubated with the indicated anti-sera. The samples were viewed by means of epifluorescence using a Zeiss Axiovert 200 microscope equipped with a Bio-Rad Radiance 2100 confocal system. The images were obtained using the Laser Sharp software package programs (Bio-Rad).
[0129] Mass spectrophotometry (MS) analysis. The proteins were passed through C-18 ZipTip tips minicolumns (Millipore, Bedford, Mass., USA) and eluted in matrix solution (3,5-dimethoxy-4-hydroxycinnamic acid saturated in aqueous solution of 33% acetonitrile and 0.1% trifluoroacetic acid). An aliquot of 0.7 μl of the resulting mixture was placed in a steel MALDI probe which was subsequently air dried. The samples were analyzed using a Bruker Reflex™ IV MALDI-TOF mass spectrometer (Bruker-Franzen Analytic GmbH, Bremen, Germany) equipped with a SCOUT™ reflector source in positive ion reflector mode using delayed extraction. The acceleration voltage was 20 kV. The equipment was externally calibrated using mass signals corresponding to BSA and BSA dimers ranging from 20-130 m/z.
EXAMPLE 1
Deletion of the C-terminal End of the VP3 Protein Eliminates the Formation of IBDV VLPs
[0130] It has recently been disclosed that the C-terminal end of VP3 contains the domain responsible for the interaction of this protein with the VP1 protein (Maraver, A., et al. Identification and molecular characterization of the RNA polymerase-binding motif of the inner capsid protein VP3 of infectious bursal disease virus). As a result, it was decided to analyze the possible role of the C-terminal region of VP3 in the morphogenesis of IBDV VLPs. As a starting ground for this analysis, the recombinant vaccine virus referred to as VT7/PolyΔ907-1012, expressing a deleted form of VP3 lacking the 105 C-terminal end residues (Sánchez Martínez, A. B. 2000. “Caracterización de las modificaciones co y post-traduccionales de la poliproteína del virus de la bursitis infecciosa”. Doctoral Thesis. Universidad Autónoma of Madrid. Facultad of Ciencias Biológicas), was used ( FIG. 1A ). The SDS-PAGE and Western blot analysis showed that the deletion does not affect the cotranslational proteolytic processing of the polyprotein (Sánchez Martínez, A. B. 2000. Doctoral Thesis cited supra). Expression of the PolyΔ907-1012 protein gives rise to the formation of tubular structures similar to the type I tubules formed in cells infected with IBDV (Kaufer, I., and E. Weiss 1976. Electron-microscope studies on the pathogenesis of infectious bursal disease after intrabursal application of the causal virus. Avian Dis. 20:483-95). The tubular structures formed by expression of PolyΔ907-1012 were detected by means of immunofluorescence using antibodies anti-VPX/2 (anti-pVP2NP2) and anti-VP3 ( FIG. 1B ), and by means of electron microscopy of fractions obtained by means of purification on sucrose gradients ( FIG. 1C ). The Western blot analysis confirmed the presence of VPX and VP3 in the tubules.
[0131] For the purpose of confirming that the mentioned phenotype was due to the deletion within the region corresponding to VP3, an experiment was carried out coinfecting BSC-1 cells with VT7/PolyΔ907-1012 and VT7VP3. VT7/VP3 is a virus vaccine recombinant expressing the whole VP3 protein (Fernández-Arias, A., et al. 1997. The major antigenic protein of infectious bursal disease virus, VP2, is an apoptotic inducer. J. Virol. 71:8014-8). A confocal microscopy analysis showed that the coexpression of the whole VP3 protein produces a significant reduction in the formation of type I tubules. In the coinfected cells, the subcellular distribution of the VPX/VP3 proteins is characterized by the formation of short tubules and viroplasms similar to those detected in cells infected with the whole polyprotein ( FIG. 1B ). This observation indicates that the coexpression of the whole VP3 protein partially salvages the ability of the PolyΔ907-1012 protein to form VLPs. The electron microscopy analysis of fractions derived from the coinfection confirmed this hypothesis. Therefore, the top fractions of the gradient were highly enriched in short tubules and quasi-spherical assemblies, called capsoids, with a diameter of 60-70 nm, together with a small proportion of VLPs of polygonal contour ( FIG. 1C ). The Western blot analysis of the top fractions of the gradient, which contained the highest concentration of capsoids, clearly showed that they contained a larger ratio of whole VP3 protein than of VP3Δ907-1012 protein (data not shown). This result indicated that the incorporation of the whole VP3 protein in these structures is more efficient than that of the deleted form. These results show that the C-terminal end of VP3 plays a fundamental role in the morphogenesis of the IBDV capsid.
[0132] The VP3 protein undergoes a proteolytic processing in insect cells. It has previously been disclosed that the expression of the IBDV polyprotein in insect cells produces the assembly of long tubules formed by VPX trimer hexamers (Da Costa, B., C. Chevalier, C. Henry, J. C. Huet, S. Petit, J. Lepault, H. Boot, and B. Delmas 2002. The capsid of infectious bursal disease virus contains several small peptides arising from the maturation process of pVP2. J. Virol. 76:2393-402; Martínez-Torrecuadrada, J. L., et al. 2000. Different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. Virology. 278:322-31). The similarity between the tubules observed in mammalian cells infected with VT7/PolyΔ907-1012 and those detected in insect cells infected with recombinant baculoviruses expressing the whole polyprotein led to the analysis of the condition of the VP3 protein accumulated in insect cells. To that end, cell extracts infected with IBDV, VT7/Poly (Fernández-Arias, A., et al. 1998. Expression of ORF A1 of infectious bursal disease virus results in the formation of virus-like particles. J. Gen. Virol. 79: 1047-54) and FB/Poly, respectively, were analyzed by means of Western blot using anti-VP3 serum (Fernández-Arias. A., et al. 1997. The major antigenic protein of infectious bursal disease virus, VP2, is an apoptotic inducer. J. Virol. 71:8014-8). In cells infected with IBDV and VT7/Poly, the presence of a single band of 29 kDa, the expected size of the whole VP3 protein, was detected by means of Western blot ( FIG. 2 ). On the contrary, in insect cells infected with FB/Poly, the presence of two bands corresponding to polypeptides of 29 and 27 kDa, respectively, was detected by means of Western blot ( FIG. 2 ). An analysis of the time expression showed that even though the appearance of the product of 27 kDa is slightly delayed with regard to the appearance of the product of 29 kDa, it becomes predominant in the later stage of infection ( FIG. 8A ). A similar analysis carried out in Sf9 cells produced identical results (data not shown). These results show that in insect cells, the VP3 protein undergoes a post-translational modification giving rise to the accumulation of a product of 27 kDa.
[0133] The infection of insect cells with a recombinant baculovirus, FB/his-VP3, expressing a version of VP3 containing a six-histidine residue tag (6xhis), called his-VP3 ( FIG. 3A ), gives rise to the accumulation of two molecular forms of the protein of 32 and 30 kDa, respectively, similar to those observed in cells infected with FB/Poly (Kochan, G., et al. 2003. Characterization of the RNA binding activity of VP3, a major structural protein of IBDV. Archives of Virology 148:723-744). Therefore, FB/his-VP3 was used as a tool to determine the origin of the smaller VP3 protein. To that end, both total cell extracts infected with FB/his-VP3 and protein purified by means of IMAC were analyzed by means of SDS-PAGE and Western blot using anti-VP3 serum ( FIG. 3B ) and anti-6xhis ( FIG. 3C ). As shown in FIG. 3B , the polyprotein of the 30 kDa is present in the purified protein sample, which shows that its N-terminal end remains intact. On the other hand, both the product of 32 kDa and that of 30 kDa are recognized by both antisera ( FIGS. 3B and 3C ). These results strongly indicate that in insect cells, the VP3 protein undergoes proteolysis, giving rise to a product lacking a fragment of 2 kDa at its C-terminal end. For the purpose of firmly determining this possibility, six recombinant baculoviruses called his-VP3Δ253-257, his-VP3Δ248-257, his-VP3Δ243-257, his-VP3Δ238-257, his-VP3Δ233-257 and his-VP3Δ228-257, respectively ( FIG. 4A ) were used [they correspond to those defined in the section of Materials and Methods, sub-section Cells and Virus, with an identical nomenclature, but. preceded by “FB/” (indicative of the name of the plasmid used for generating the viruses (pFastBac1)]. These recombinant baculoviruses express a series of deletion forms of VP3 containing a histidine tag. The deletions were generated to progressively eliminate groups of 5 amino acid residues and thus generate a collection with growing deletions at the C-terminal end of the VP3 protein, as shown in FIG. 4A . The expression of these proteins was analyzed by means of Western blot using anti-VP3 serum. As shown in FIG. 4B , the expression of the his-VP3 (his-VP3 wt) whole protein and of the his-VPΔ253-257 mutant protein gave rise to the formation of doublets. On the other hand, the proteins containing deletions of 10 or more residues migrated according to their expected size, giving way to a single band ( FIG. 4B ). This result shows that the C-terminal end of the VP3 protein is proteolytically processed and that the deletion of the cleavage site prevents proteolysis. The electrophoretic mobility of the his-VP3Δ248-257 protein is slightly less than that of the polypeptides generated by proteolytic processing of his-VP3 and his-VP3Δ253-257, which indicates that the processing occurs in the region located between residues 243 and 248. The C-terminal end of the his-VP3Δ248-257 protein is probably too short so as to allow the recognition on the part of the protease, and therefore it would not undergo proteolytic processing.
[0134] For the purpose of confirming the results obtained with the his-VP3 deletion mutants and precisely establishing the proteolytic cleavage site in the VP3 protein, H5 cell extracts infected with FB/his-VP3 were subjected to purification by means of IMAC. The resulting purified protein was analyzed by means of mass spectrometry. The experiment was repeated three times using independent purifications. The obtained results were similar in all cases (a difference in mass of less than 0.03%). FIG. 5A shows the results of one of these experiments. The presence of two polypeptides of 32,004 and 30,444 Da, respectively, was determined. These results show that the proteolytic processing causes the elimination of a peptide of 1,560 Da from the C-terminal end of his-VP3. This size fits with the molecular mass (1,576 Da) corresponding to the 13 C-terminal residues of VP3 (SEQ. ID. NO: 3) ( FIG. 5B ).
[0135] These results as a whole show that the VP3 protein is proteolytically processed in insect cells between the L244 and G245 residues, giving rise to a polypeptide lacking the 13 C-terminal residues.
EXAMPLE 2
Generation of a Recombinant Baculovirus Coexpressing the A1 and B1 Open Reading Frames of the IBDV Genome
2.1 Construction of the Plasmid PFBD/VP1
[0136] The nucleotide sequence corresponding to the B1 open reading frame of the IBDV genome was obtained from the plasmid pBSKVP1 described above (Lombardo, E., et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83). The plasmid was purified and subjected to the following enzymatic treatments: i) digestion with the restriction enzyme NotI; ii) incubation with the Klenow fragment of DNA polymerase of E. coli in the presence of dNTPs; and iii) digestion with the restriction enzyme XhoI. Then the corresponding DNA fragment was purified and used for its cloning into the vector pFastBacDual (Invitrogen) previously treated with restriction enzymes XhoI and PvuII. For this, the DNA fragment and the linearized plasmid were incubated in the presence of T4 DNA ligase to generate the plasmid pFBD/VP1.
2.2 Construction of the Plasmid pFBD/Poly-VP1
[0137] The nucleotide sequence corresponding to the Al open reading frame of the IBDV genome was obtained from the plasmid pCIneoPoly described above (Lombardo, E., et al. 1999. VP1, the putative RNA-dependent RNA polymerase of infectious bursal disease virus, forms complexes with the capsid protein VP3, leading to efficient encapsidation into virus-like particles. J. Virol. 73:6973-83). The plasmid was purified and incubated with the restriction enzymes EcoRI and NotI. The corresponding DNA fragment was purified and incubated with the plasmid pFBD/VP1, previously digested with the restriction enzymes EcoRI and NotI, in the presence of T4 DNA ligase to generate the plasmid pFBD/Poly-VP1. A bacteria culture transformed with said plasmid pFBD/Poly-VP1 has been deposited in the CECT with deposit number CECT 5777.
2.3 Obtaining the Bacmid Bac/pFBD/Poly-VP1
[0138] This was carried out by means of the transformation of competent bacteria DH10Bac (Invitrogen), positive colony selection in selective medium and purification following the methodology disclosed by Invitrogen (catalog numbers 10359016 and 10608016).
2.4 Obtaining the Recombinant Baculovirus FBD/Poly-VP1
[0139] The virus was obtained by means of transfection of H5 cells (Invitrogen) with the bacmid Bac/pFBD/Poly-VP1 previously purified following the methodology disclosed by Invitrogen (catalog numbers 10359016 and 10608016).
EXAMPLE 3
Obtaining Whole IBDV VLPs from H5 Cells Infected with the Recombinant Baculovirus FBD/Poly-VP1
[0140] H5 cell cultures were infected with the recombinant virus FBD/Poly-VP1 (Example 2) using a multiplicity of infection of 5 plaque forming units per cell. The cultures were harvested at 72 hours post-infection (h.p.i). The cells were settled by means of centrifugation (1.500×g for 10 minutes). The cellular sediment was resuspended in PES buffer (PIPES (1,4-piperazine ethanesulfonic acid) 25 mM, pH 6.2, NaCl 150 mM, CaCl 2 20 mM). Then the cells were homogenized by means of three consecutive freezing/thawing cycles (−70° C./+37° C.). The corresponding homogenate was centrifuged (10,000×g for 15 minutes at 4° C.). The resulting supernatant was harvested and used for the purification of the VLPs. To that end, a centrifuge tube with a 25% sucrose cushion (weight/volume), diluted in PES buffer of 4 ml, was prepared, depositing 8 ml of supernatant thereon. The tube was centrifuged (125,000×g for 3 hours at 4° C.). The resulting sediment was resuspended in 1 ml of PES buffer. Then a continuous 25-50% sucrose gradient in PES buffer was prepared in a centrifuge tube, depositing the resuspended sediment thereon. The tube was centrifuged (125,000×g for 1 hour at 4° C.). Then the gradient was fractioned into aliquots of 1 ml.
[0141] The different aliquots were analyzed by means of transmission electron microscopy. To that end, a volume of 5 μl of each sample was placed on a microscope grid. The samples were negatively stained with an aqueous solution of 2% uranyl acetate. A Jeol 1200 EXII microscope operating at 100 kV and at a nominal magnification of 40,000× was used. This analysis showed the presence of whole VLPs structurally identical to the IBDV virions in the analyzed samples.
[0142] For the purpose of determining the protein composition of the VLPs detected by means of electron microscopy, the samples were analyzed by means of Western blot. To that end, the samples were subjected to polyacrylamide gel electrophoresis. The gels were subsequently transferred to nitrocellulose and incubated with anti-VPX/2 antibodies (anti-pVP2VP2), anti-VP3 and anti-VP1. The results showed the presence of the VPX, VP2, VP3 and VP1 proteins in the fractions containing VLPs.
[0000] Microorganism Deposit
[0143] A culture of the bacteria derived from DH5, carrier of a plasmid containing the IBDV polyprotein-VP1 genetic construction (pFBD/Poly-VP1), DH5-pFBD/poly-VP1, has been deposited in the Spanish Culture Type Collection (CECT), University of Valencia, Research Building, Burjasot Campus, 46100 Burjasot, Valencia, Spain, on Mar. 8, 2003, with deposit number CECT 5777.
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Whole empty viral particles of infectious bursal disease virus (IBDV), which contain all of the antigenically-relevant proteinaceous constituents present in determinant IBDV virions. The whole empty virus particles are readily produced in suitable expression systems to provide capsids that can be used in the production of vaccines against avian disease, e.g., infectious bursitis caused by IBDV, and in the development of gene therapy vectors.
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TECHNICAL FIELD
This invention is directed to separation of lubricant from refrigerant in compressors, and more particularly, the separation of lubricant from refrigerant in a lubricant still.
BACKGROUND OF THE INVENTION
Screw or helical compressors are commonly used in air conditioning applications to compress refrigerant as part of the refrigeration cycle. Screw compressors are composed of meshing screw or helical rotors. While two rotor configurations are the most common design, screw compressors are also known in the art having three, or more, rotors housed in respective overlapping bores so as to co-act in pairs. The rotors of a typical screw compressor are mounted in bearings at each end in housing end plates at the inlet and discharge side. Refrigerant is compressed by the screw rotors toward the discharge side and discharged through ports and into a discharge line.
In normal applications, a solution or mixture of oil and refrigerant is used for lubricating screw compressor bearings and rotors. This lubricant becomes entrained in the refrigerant while the refrigerant passes through and is compressed. If this entrained lubricant is not separated and recovered by some means, it passes through condenser and liquid line and accumulates in the evaporator where it is mixed with liquid refrigerant. As a result, evaporator heat transfer effectiveness is degraded. Oil foam may also be created, which is entrained in suction flow entering the compressor, reducing the refrigerant flow rate of the compressor. Even worse, lubricant supply for bearing and rotor lubrication is eventually depleted.
In the past, oil separators have been utilized immediately downstream of the compressor. While oil separators do separate the lubricant, they have not always provided fully satisfactory results. As an example, the lubricant removed with such a separator will be at a high pressure, and may have an appreciable amount of refrigerant mixed in with the oil. This lowers its viscosity, degrading its usefulness as a bearing lubricant. The use of a separator can also cause a pressure drop in the compressed refrigerant, which is undesirable. A separator may also radiate sound due to internal pressure pulsations acting on its walls. A separator may also add considerable cost to the system since it is a pressure vessel of considerable size.
Another approach to lubricant separation is by use of a concentrator, or still, attached to the evaporator, also sometimes referred to as a generator as, shown for example in U.S. Pat. No. 6,182,467 B1. In such systems, a portion of the oil and refrigerant mix residing in the evaporator is made to flow into the concentrator, where means are provided for heating the mixture to cause some liquid refrigerant to vaporize. The liquid remaining thereby contains a higher fraction of oil. By suitable choice of the amount of refrigerant vaporized, a liquid with sufficient viscosity for use as a bearing lubricant may be created.
Referring to FIG. 3 , such a prior art lubricant still is shown in detail, wherein the still 28 comprises a pressure tight vessel 30 , which includes an inlet 32 for oil laden refrigerant 7 , drawn off the evaporator, below the liquid level line, an outlet 34 for gaseous refrigerant, an oil outlet 36 for out flowing concentrated oil that has undergone separation. Still/reservoir 28 further includes a coil 42 through which the hot refrigerant flows for transfer of heat to the incoming oil/refrigerant mixture. Coil 42 has an inlet 38 for hot refrigerant and an outlet 40 for cooled refrigerant having gone through a heat transfer process.
The use of such stills for creating a lubricant from the oily refrigerant mix normally residing in an evaporator is a known art, with the viscosity resulting from still action in the range of 3 to 20 centipoise (cP). However, for some screw compressors, particularly those operated at low speeds, much higher lubricant viscosity of at least 50 cP is required. Approaches to achieving higher viscosity lubricants in conventional stills are less than satisfactory. For example, simply increasing the amount of heat provided to vaporize refrigerant may result in somewhat higher lubricant viscosity but may also incur a severe penalty to system efficiency since the extra heat provided must be accounted for when calculating the system efficiency. Moreover, conventional stills are defective in producing adequate lubricant viscosity during operating transients that result in sudden increases in the influx rate of oil laden refrigerant from the evaporator. During such transients the entering liquid tends to flood the still, mixing with liquid that has resided in the still for some time and lowering its viscosity.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved lubricant still for use with a compressor for the separation of lubricant from refrigerant.
It is another object of this invention to provide an improved lubricant still that produces lubricant of high viscosity and maintains high viscosity during operating transients that result in increased flow of oil laden refrigerant from evaporator to still.
These objects, and others as will become apparent hereinafter, are accomplished by the lubricant still of the present invention for use in a compressor for separating lubricant from refrigerant. The still includes a vessel having an inlet for incoming oil laden refrigerant, an outlet for gaseous refrigerant, and an outlet for refrigerant laden oil. A separating structure is provided for separating transitioning oil laden refrigerant from the incoming oil-laden refrigerant, wherein the oil laden refrigerant progressively changes to refrigerant laden oil closer to the outlet for refrigerant laden oil. A heating device is used for heating the incoming oil laden refrigerant and transitioning oil laden refrigerant, for facilitating the formation of the gaseous refrigerant and the refrigerant laden oil.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the present invention, reference should now be made to the following detailed description thereof taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic diagram of a refrigerant system;
FIG. 2 is a simplified schematic view of a screw compressor showing the discharge end and connections to the discharge line;
FIG. 3 is a simplified schematic view of a prior art still;
FIG. 4 is a simplified schematic view of an embodiment of a lubricant still of the present invention;
FIG. 5 is a view of the preferred embodiment of a lubricant still of the present invention;
FIG. 6 is a perspective view of a component of the lubricant still shown in FIG. 5 ;
FIG. 7 is a view of the an alternative embodiment of the oil still of the present invention; and
FIG. 8 is an alternative embodiment of the oil still shown in FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail there is shown in FIG. 1 a schematic view of a refrigerant system 1 , including a compressor 2 .
As is known, a flooded style evaporator 3 delivers primarily gaseous refrigerant to the compressor 2 through a line 4 . Gaseous refrigerant is compressed by compressor 2 , entraining lubricant during its passage through compressor 2 that is used to lubricate the bearings and rotors of compressor 2 . From the compressor 2 , refrigerant with entrained oil passes through a line 5 to a condenser 6 . Compressed gaseous refrigerant is cooled in the condenser, transferred into a liquid phase, with oil in mixture or solution, as it passes in line 11 through an expansion valve (not shown) to evaporator 3 . At the evaporator 3 , an environment to be cooled is cooled by the refrigerant in the evaporator. As is shown, it is typical that liquid refrigerant 7 settles from the refrigerant in the evaporator. This refrigerant 7 is typically lubricant or oil laden as a result of the oil entrained during the compression process and associated lubrication, and a portion of the oil laden refrigerant is transferred via line 8 to lubricant still 128 , described further below, according to the principle of the present invention. A portion of this lubricant is drawn off using an oil pump (not shown) and delivered to compressor 2 through line 13 for lubrication of bearings and rotors.
Referring to FIG. 2 , an example of how oil enters the refrigerant during the compression process will be further described. Shown in FIG. 2 is a screw compressor 10 , that includes a rotor housing 12 containing intermeshing screw rotors 14 and 15 and bearings 17 on suction-side of screw rotors, refrigerant inlet 18 and discharge port 20 , including a discharge bearing housing 22 containing discharge-side bearings 23 and discharge housing 24 that is connected with a discharge line 26 . In operation, assuming rotor 14 to be the driving rotor, rotor 14 rotates engaging the other rotors 15 , causing their rotation. The co-action of rotating rotors 14 and 15 draws refrigerant gas via suction inlet 18 into the grooves of rotors 14 and 15 that engage to trap and compress volumes of gas and deliver hot compressed refrigerant gas to discharge port 20 . In addition, and simultaneously, lubricant is injected into the screw rotors for effective lubrication of the rotors, and as a result oil becomes mixed with refrigerant. Simultaneously, lubricant is also delivered to suction bearings 17 and discharge bearings 23 . Some or all of bearing lubricant may also leak internally and ultimately be entrained in refrigerant passing through. The hot compressed refrigerant with the lubricant therein moves through the system 1 described above. The present invention is used to separate the lubricant from the refrigerant for use for lubricating the compressor.
While the present invention is shown being used with a screw compressor, it may also be used with other types of compressors as well.
As shown in FIG. 4 and also referring to FIG. 1 , an embodiment of the lubricant still of the present invention, still 128 , comprises a pressure tight vessel 130 , which includes an inlet 132 for oil laden refrigerant 7 , drawn off the evaporator, below the liquid level line, an outlet 134 for gaseous refrigerant and a lubricant outlet 136 for out-flowing lubricant of high viscosity that has undergone separation. Still 128 includes a series of liquid reservoirs 138 created by partitions 140 acting in concert with portions of the inner wall of pressure tight vessel 130 . In this embodiment, heat for vaporizing some liquid refrigerant in oil laden refrigerant 7 is provided by electric heater 150 , which is in close proximity to the lower wall 151 of pressure tight vessel 130 . Other arrangements for electric heaters, including locating them within vessel 130 , and other means for providing heat, such as providing tubes containing hot liquid or gas refrigerant or hot water, are also compatible with this embodiment of the present invention.
Gaseous refrigerant created by heat acting on liquid in any of reservoirs 138 rises within vessel 130 and eventually exits through vent 134 , which is connected (not shown) to either evaporator 3 or passage 4 . Flow of liquid through still 128 is due to the effect of gravity G, wherein vessel 130 is tilted downwardly from inlet 132 , as shown. In FIG. 4 flow occurs from right to left, proceeding over the top of each partition 140 and through each reservoir 138 in sequence, from 138 a to 138 e . The most upstream reservoir 138 a in the sequence is connected to inlet 132 and typically contains a high fraction of the oil laden refrigerant 7 . The most downstream reservoir in the sequence 138 e is connected to lubricant outlet 136 and acts as a lubricant reservoir. The construction of partitions 140 , such that flow occurs over their tops T, is an aspect of the present invention. Oil rich liquid or foam, shown typically as 152 in FIG. 4 , tends to rise to the top of reservoirs 138 due to buoyancy, because the density of the liquid/foam 152 is lower than the density of other liquid present in reservoirs 138 . Thus, oil rich liquid and foam flows in reservoirs 138 over the tops T of partitions 140 , over the other liquid in the reservoirs. By this means, the oil concentration of the liquid in reservoirs 138 increases as flow progresses downstream in the sequence of reservoirs 138 , from 138 a to 138 e . Through this means, a lubricant of high viscosity is developed in the most downstream reservoir 138 e , which acts as a lubricant reservoir. During operating transients when the influx rate of oil laden refrigerant entering the most upstream reservoir 138 a through inlet 132 increases, the liquid flow rate through still 128 also increases. However, because the liquid is refrigerant rich, its density is higher than oil rich liquids or oil rich foams 152 , leading to downstream flow over the tops T of partitions by the more oil rich liquids and foams 152 , as previously described. Thus, even during such transients, the progression of additional refrigerant rich liquid downstream is hindered and the high viscosity of the lubricant in the most downstream reservoir is substantially maintained.
An additional advantage in vaporizing refrigerant to create a lubricant of high viscosity may be realized by designing the reservoirs 138 such that their free surface area-to-volume ratio is as high as possible as it is known that the migration of vaporizing refrigerant from a mixture or solution of liquid refrigerant and oil is enhanced as free surface area-to-volume ratio increases. Thus, within the bounds of cost-effective construction, the depth (the measure of the reservoirs 138 into the page) and length of reservoirs 138 should be maximized relative to their height.
Another preferred embodiment is shown in FIGS. 5 and 6 . Referring to FIG. 5 , and also referring to FIG. 1 , similar to as described above, a still 228 comprises a pressure tight vessel 230 , which includes an inlet 232 for oil laden refrigerant 7 , drawn off the evaporator, below the liquid level line, an outlet 234 for gaseous refrigerant and a lubricant outlet 236 for out flowing lubricant of high viscosity that has undergone separation. Still 228 further includes a series of liquid reservoirs 238 a to 238 g created by partitions 240 . Reservoirs 238 a to 238 g and partitions 240 are preferably made by stamping their forms in sheet metal of relatively high conductivity such as steel, aluminum or copper to form the entire series of reservoirs 238 and entire series of partitions 240 in a single pan-shaped piece 242 of high conductivity material, having an elongated flattened shape, as shown in FIG. 6 . In this embodiment heat for vaporizing some liquid refrigerant in oil laden refrigerant 7 is preferably provided by flow of hot refrigerant gas drawn off the condenser or, as shown in FIG. 1 , from a tap 39 off the discharge line 5 of compressor 2 , entering through an inlet 260 in FIG. 5 and exiting through outlet 262 as cooled refrigerant having gone through a heat transfer process. The refrigerant flows through an internal passage defined by the single piece 242 and a matching bottom piece 244 , described further below with reference to FIG. 6 . Pan 242 is fastened within vessel 230 on an angle as shown, using conventional means such as, for example, brazing, welding, bolting or shimming.
Gaseous refrigerant created by heat acting on liquid in any of reservoirs 238 rises within vessel 230 and eventually exits through vent 234 , which is connected (not shown) to either evaporator 3 or passage 4 . Flow of liquid through still 228 is due to the effect of gravity G and the orientation of pan 242 . Referring still to FIG. 5 , flow occurs from right to left beginning at inlet 232 through the series of reservoirs 238 a to 238 g and over the series of partitions 240 , ending in the most downstream reservoir 238 h . The most upstream reservoir in the sequence 238 a , connected to inlet 232 , typically contains a high fraction of the oil laden refrigerant 7 . The most downstream reservoir 238 h in the sequence is connected to lubricant outlet 236 and acts as a lubricant reservoir. The construction of partitions 240 such that flow occurs over their tops T. In other respects, aspects of the embodiment shown in FIG. 5 pertinent to creating and maintaining a lubricant of high viscosity are the same as those of the embodiment shown in FIG. 4 , and previously described.
With reference to FIG. 6 , the pressure-tight passage for flow of the hot refrigerant gas is made, using the single piece of high conductivity material 242 (described above) as an upper boundary and part of side boundaries for hot refrigerant gas flow and a single lower piece 244 , preferably stamped from a single sheet of the same high conductivity material as 242 is formed from, as a lower boundary and forming part of the side boundaries. 242 and 244 are suitably joined in a pressure-tight manner, preferably also by brazing. Inlet 260 and outlet 262 may suitably be joined in a pressure tight manner to the assembly of 242 and 244 , preferably by brazing or could be formed as an integral part of pieces 242 and 244 .
In accordance with another embodiment of the present invention, and referring to FIG. 7 , a still 328 includes at least one flat separating pan 344 positioned in coil 342 , dividing the cavity 346 of vessel 330 into two Zones A and B, and which is angled downwardly such that liquid will flow over its surface. This division by pan 344 effectively separates the oil-laden refrigerant from the refrigerant-laden oil, by creating the two separate zones A and B. Accordingly no immediate mixing of oil-laden refrigerant with refrigerant-laden oil occurs, thereby avoiding the pitfalls of the prior art that allows such mixture and effectively dilutes the separation process. Pan 344 is preferably in intimate contact with coil 342 to facilitate efficient heat transfer with the oily refrigerant and has an elongated, flattened shape. The flattened shape functions to spread the oil-laden refrigerant out in a thin layer which enhances the distillation process and separation of the lubricant from the oil-laden refrigerant. Accordingly, Zone A located in the upper region of cavity 346 functions as the distilling region, wherein the oily refrigerant at about 90-95% refrigerant enters from the evaporator at saturation temperature and pressure. Heat is transferred from the hot refrigerant in the coil and causes the refrigerant portion of the oily refrigerant to vaporize and separate from the oil-laden refrigerant. The separated refrigerant vapor exits through outlet 334 .
In Zone B, lubricant, consisting of oil with about 10-40% refrigerant collects, having moved down pan 344 into the bottom of vessel 330 .
As an alternative to coil 342 , an electric heater 348 shown by dotted lines can be used to supply the necessary heat to the pan.
In operation, oil laden refrigerant which is 90-95% refrigerant enters vessel 330 from the evaporator through inlet 332 onto pan 344 , and hot refrigerant enters inlet 338 drawn off the condenser or the compressor discharge line, and circulates through coil 342 . Heat is transferred from the hot refrigerant in the coil causing the oil laden refrigerant to reach saturation temperature and results in vaporization of the majority of the refrigerant, which exits as a gas through outlet 334 to the slanted orientation of the pan, liquid flows down the pan through Zone A and drips into Zone B at the bottom of vessel 330 . Heating by the refrigerant in the coil continues in Zone B but is directed to the refrigerant-laden oil, causing additional boiling off of remaining refrigerant which flows as vapor out of the vessel through outlet 334 while oil flows out of vessel 330 through outlet 336 . Cooled refrigerant in the coil exits the vessel through outlet 340 .
Referring now to FIG. 8 , an alternative of the embodiment of FIG. 7 is shown. In FIG. 8 , two pans 444 a and 444 b are used, along with the same coil 142 arrangement and outlets and inlets described above. With the embodiment shown in FIG. 8 , a third Zone AB is added intermediate to Zones A and B, that acts to further separate refrigerant from the oil laden refrigerant for exiting of vessel 430 through outlet 434 . Zone AB functions in a manner similar to that described above for Zone A, acting as a supplementary step to the process described in Zone A. Pans 444 a and 444 b are each slanted downward, wherein pan 444 a has less of an incline than pan 344 and leads the liquid to pan 444 b . Pan 444 b is slanted in the opposite direction of pan 444 a , such that the lower point 450 of pan 444 a is almost vertically coincident with the higher point 452 of pan 444 b , but sufficiently offset to allow liquid flow from one pan to the next. Operation in Zones A and B, and the remaining inlets and outlets, but for their locations due to the differing pan arrangement; are the same as described above for the FIG. 7 embodiment.
Although preferred embodiments of the present invention have been illustrated and described, other changes will occur to those skilled in the art. It is therefore intended that the scope of the present invention is to be limited only by the scope of the appended claims.
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A lubricant still for use in a compressor for separating oil from refrigerant, includes a vessel having an inlet for incoming oil laden refrigerant, an outlet for gaseous refrigerant, and an outlet for refrigerant laden oil. A separating structure is provided for separating transitioning oil laden refrigerant from the incoming oil-laden refrigerant, wherein the oil laden refrigerant progressively changes to the refrigerant laden oil closer to the outlet for refrigerant laden oil. A heating device is used for heating the incoming oil laden refrigerant and transitioning oil laden refrigerant, for facilitating the formation of the gaseous refrigerant and the refrigerant laden oil.
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TECHNICAL FIELD
The present invention relates generally to a method and apparatus for providing differentiated services in a communications network, and more particularly to a method and apparatus for providing differentiated services in a communications network having different access network types.
BACKGROUND
Different new access technologies and networks are being introduced towards mobile core networks and mobile services. Two examples of these are Generic Access Network (GAN), also known as Unlicensed Mobile Access (UMA), and Femto GSM and WCDMA solutions. The GAN solutions were initially defined in the 3 rd generation partnership project (3GPP) TS 43.318 and 44.318 for 3GPP Releases 6 and 7. In these specifications, the GAN can be used to provide access to second generation public land mobile networks (PLMN) and the services available in these networks including GSM (Global System for Mobile Communication), EDGE (Enhanced Data rates for GSM Evolution) and GPRS (General Packet Radio Service networks). The interfaces used between GAN and the CN in these GAN solutions are the typical GSM RAN-CN interfaces, i.e. A and Gb interfaces for voice and data traffic, respectively, as defined in 3GPP TS 48.008 and 3GPP TS 48.018. In addition, work is now ongoing in 3GPP for Release 8 to specify generic access networks for third generation services, i.e. for UMTS (Universal Mobile Telecommunications System) or WCDMA (Wideband Code Division Multiple Access). The corresponding technical specifications will be called 3GPP TS 43.319 and 44.319 and will also include the previous content from specifications 43.318 and 44.318 in 3GPP Releases 6 and 7. This addition will provide the possibility to use the existing UMTS/WCDMA RAN-CN interfaces between the GAN and the CN, i.e. lu-cs and lu-ps interfaces, for voice and data traffic, respectively as defined in 3GPP TS 25.410. All these GAN solutions are based on usage of unlicensed radio technology and need new mobile terminals. Generic Access Network (GAN) is a technology that enables GSM and WCDMA services to be delivered over broadband access network and WLAN, at homes or in offices. End users will enjoy the same service as in the wide area network.
The Femto GSM and Femto WCDMA solutions use also, in a similar way as the GAN solutions, the existing RAN-CN interfaces, i.e. the A and Gb interfaces in the Femto GSM and the lu interfaces in the Femto WCDMA solution.
The GAN technology defines an access network to the mobile core network that can be used to access the existing circuit-switched and packet-switched services. The access network is based on use of unlicensed spectrum and IP-based broadband access networks that may include both wireless and wired portions. GAN can be seen as complementary to GSM and WCDMA radio networks providing local area coverage. The GAN infrastructure should preferably be integrated in to the existing radio network infrastructure to optimize network performance. With GAN the end user experience remains the same in the WLAN radio network as in GSM and WCDMA radio networks, including seamless handover and roaming between these radio networks. GSM and WCDMA services are available when the end user is connected via the WLAN.
The Femto GSM and WCDMA solutions are based on using existing mobile terminals and the existing licensed radio technologies.
The GAN solutions can be used in combination with an existing Access Point (AP), e.g. a WiFi or WLAN AP. The Femto GSM and Femto WCDMA solutions need a new Home Access Point (AP) to provide the local coverage at e.g. homes. Other call rates and other or additional services may be provided while the Home AP is used to access the mobile services. This means also that the operator macro GSM or WCDMA network is offloaded with the traffic created over the GAN or Femto solutions. The cheaper call rates are also needed as the end users pay and provide part of the communication needed (e.g. the Home AP and/or the broadband access connection).
The cheaper call rates for mobile originating calls and transactions are known and there exist different solutions for this need. Different charging for mobile terminated calls and other service differentiations when the new access technologies are used is also desired. A problem with service differentiation comes from the main advantage of the new access technologies, i.e. that the terminal has one single telephone number that is used when the terminal is connected via the existing macro networks and the new access networks. This means that the tariff or call rate can not be selected in the originating network only based on the called number of the B-party as the same number is used independently of the access network being used by the called party in the terminating network. In the same way, the transparency of the GAN and the Femto solutions to the CN (as existing RAN-CN interfaces are used) means that the CN in the terminating side is not necessarily aware of when GAN or the Femto solutions are being used by the called user.
There exists some IN (Intelligent Network) based solutions that can be used to have different charging based on “A” and “B” side locations, e.g. one tariff if both subscribers are in the same town. These methods are using information from the HLR, e.g. Location Number or VLR number. The main problem with such a solution is that one (MSC/)VLR cannot be used to serve different types of accesses (e.g. GAN, GSM, Femto GSM, Femto WCDMA) with different types of charging for mobile terminated calls. This problem comes from the fact that the HLR is for example not updated with a new VLR number when the end user moves between GAN and GSM accesses connected to the same MSC/VLR. In the same way, if “A” and “B” sides are connected to different networks, then the existing logic based on finding out that the users are in the same town using the same network can not be applied i.e. there is no known way to communicate the needed information between different networks and apply it for charging. One of the main goals with adding the new GAN and Femto solutions is to keep the added signaling load in the CN to a minimum possible. This means that it is desired that an end user moving between for example the GSM and GAN accesses doesn't need to change the current MSC/VLR. This means for example that Inter-MSC handovers and location updates are avoided to minimize the Inter-MSC and HLR signaling.
SUMMARY
It is an object of the present invention to provide a method and apparatus for providing differentiated services in a communications network having different access network types.
One aspect of the present invention is a method of providing differentiated services in a communications network. The method comprises:
receiving in a mobile services switching centre an indication message from a first radio access network, said message indicating a radio access network type to which a called communication apparatus of a terminating communication session is connected,
in response to the indication message:
accessing differentiated service information associated with the radio access network type of the terminating communication session, and
sending the differentiated service information to be applied for service differentiation by a second access network of calling communication apparatus.
Thanks to this method, service differentiation in a communications network having different access network types can be provided by means of existing signaling protocols.
In one or more embodiments, the step of sending differentiated service information comprises sending a Charge Information ISUP message with the differentiated service information indicated in a Tariff Indicator field.
In one or more embodiments the step of sending differentiated service information comprises sending an Answer ISUP message with the differentiated service information indicated in a Generic or Connected Number field.
In one or more embodiments the step of sending differentiated service information comprises sending a Connect ISUP message with the differentiated service information indicated in a Generic or Connected Number field.
In one or more embodiments the step of sending differentiated service information comprises sending one or more of said Charge Information ISUP message and said Answer ISUP message or a Connect ISUP message with the tariff information indicated in a Generic or Connected Number field.
In one or more embodiments the step of accessing the differentiated service information comprises accessing an internal service information of the mobile services switching centre ( 108 , 109 ) and amending the differentiated service information based on the first radio access network type.
The radio access network to which the called mobile communication apparatus is connected and the radio access network to which the calling mobile communication apparatus is connected may be different radio access networks.
The location information can be Location Area Identities, LAI, or Cell Global Identifiers, CGI, for GSM networks or Location Area Identities, LAI, or Service Area Identities, SAI, for UMTS networks, or Charging Type.
The radio access network to which the called mobile communication apparatus is connected can be any of a GSM, Generic Access Network, Femto GSM, or WCDMA network.
The radio access network to which the calling mobile communication apparatus is connected can be any of a public switched telephone network, GSM, Generic Access Network, Femto GSM, or WCDMA network.
The differentiated service information may advantageously, but is not limited to, charging information for differentiated charging of terminating communication sessions.
A second aspect of the invention is a mobile services switching centre for differentiated charging of terminating communication sessions with computer capabilities. The mobile services switching centre may comprise: a computer processor for executing computer programs and processing data, and storage means connected to the computer processor for storing data and computer program. The mobile services switching centre may be configured to:
store differentiated service information associated with different radio access types,
receive an indication message from a first radio access network, said message indicating the radio access network type to which a called communication apparatus of a terminating communication session is connected,
in response to the indication message:
access differentiated service information associated with the radio access network type of the terminating communication session, and
send the differentiated service information to be applied by a second access network of calling communication apparatus.
In one or more embodiments the computer processor of the mobile services switching centre may be configured to access the differentiated service information in a table to decide if a differentiated service should be indicated with respect to the current network of the called terminal towards the network from where the call was initiated.
The differentiated service information may advantageously be, but is not limited to, charging information.
Moreover, the charging information may be a numeric value indicating a specific tariff, or a prefix, or whole telephone number that is to be used to create a generic or connected number.
In one or more embodiments, the location information is Location Area Identities, LAI, or Cell Global Identifiers, CGI, for GSM networks or Location Area Identities, LAI, or Service Area Identities, SAI, for UMTS networks, or Charging Type. It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to explain the invention in more detail and the advantages and features of the invention, a preferred embodiment will be described in detail below, reference being made to the accompanying drawings, in which
FIG. 1 illustrates an example of three different communications networks within which embodiments of present invention may be practiced,
FIG. 2 illustrates embodiments of the method and apparatus for providing differentiated tariffs or charging depending on the access network of a called mobile communication apparatus, and
FIG. 3 shows further alternative embodiments of the method and apparatus of FIG. 2 .
DETAILED DESCRIPTION
FIG. 1 illustrates an example of three different communications networks within which embodiments of present invention, i.e. a method and apparatus for providing differentiated services depending on the access network type of a called communication apparatus, may be practiced.
According to some embodiments, tariffs and/or charging may depend on the access network used on the “B-subscriber side” i.e. in the network terminating the call. A public land mobile network (PLMN) handling or terminating a mobile terminated call, returns an indication about the access network, being used, to terminate the call to the network from where the call is originated. The Core Network (CN) receives an indication of the current location from the Radio Access Network (RAN) and uses this indication to check whether a specific tariff should be indicated towards the originating network. In another embodiment, the CN receives a charging indication from the RAN and uses this indication to check whether a specific tariff should be indicated towards the originating network. In this case, the RAN contains the logic needed to select the appropriate tariff or charging class for an end user and indicates this to the CN. The selection of the appropriate tariff or charging class for an end user could be based for example on knowledge of the current AP being used in the GAN or Femto solutions.
A first network may be PLMN- 1 101 , which is a mobile network that provides macro network services (e.g. GSM) and in addition also Generic Access Network (GAN) and Femto GSM based services. A second network may be PSTN- 1 102 , which is a fixed network and a third network, may be PLMN- 2 103 , which is a conventional mobile network that only provides macro network services (e.g. GSM or WCDMA). In one or more embodiments two different end users may operate in PLMN- 1 , wherein a user- 1 may be connected to the macro GSM network by means of a first terminal 104 , and a user- 2 may be connected via either GAN or the Femto GSM by means of a second terminal 105 . Also, even not depicted, all or part of the end users in the PLMN- 1 may dynamically move between e.g. the GAN and Femto GSM accesses. Moreover, a user- 3 may be connected to the PSTN- 1 102 by means of a third terminal 106 , and a user- 4 may be connected to PLMN- 2 103 by means of a fourth terminal 107 .
The term terminal or communication apparatus includes portable radio communication equipment. The term portable radio communication equipment includes all equipment such as mobile telephones, pagers, communicators, i.e. electronic organizers, smartphones or the like.
Embodiments of the method and apparatus for providing differentiated tariffs or charging depending on the access network of a called mobile communication apparatus are described with reference to FIG. 2 . A mobile terminated call is triggered towards user- 2 of terminal 105 in PLMN- 1 101 from user- 3 of terminal 106 in PSTN- 1 102 . The messaging between the network PLMN- 1 101 and the network PSTN- 1 102 as well as the messaging between components within the PLMN- 1 101 is described. The embodiment of the method is described with reference to the called user- 2 of terminal 105 in PLMN- 1 101 and consequently the messaging within the PSTN- 1 102 is only described in general.
The network PLMN 1 101 is configured with, but is not limited to included, a mobile services switching centre (MSC) 108 with a visitors location register (VLR) 109 ; a home location register (HLR) 110 ; a gateway mobile services switching centre (GMSC) 111 , and a generic access network (GAN) 112 to which the user- 2 of terminal 105 is currently associated.
The (G)MSC provides the network with specific data about individual mobile phones and operates as an interface towards other networks such as other PLMNs, or the public switched network (PSTN). The MSC/VLR 108 , 109 may be embodied as a programmable apparatus or a data processing system, including a computer processor for executing computer programs and processing data, and storage means connected to the computer processor for storing data and computer program.
The VLR 109 contains relevant data of all mobiles currently located or roaming within the serving (G)MSC 108 , 111 . The VLR 109 has to support the (G)MSC 108 , 111 during call establishment when a call is coming from for example a mobile telephone.
The HLR 102 stores the identity and user data of all the subscribers belonging to the area of the related (G)MSC 108 , 111 . Moreover, the HLR 102 provides the (G)MSC 108 , 111 with the necessary subscriber data when a call is coming from a public switched network (PSTN), the Internet etc.
According to one or more advantage embodiments, the MSC/VLR 108 , 109 is configured with location and charging information. The location information depends on type of the mobile network, e.g. Location Area Identities (LAI) or Cell Global Identifiers (CGI) for GSM networks or Location Area Identities (LAI) or Service Area Identities (SAI) for UMTS networks. The location information may also include some additional identifier that is indicated from the RAN towards the CN (e.g. MSC/VLR).
The location information may be stored in a table 1 associated with the MSC/VLR 108 , 109 . The first column contains the location or charging indicated from the called RAN and the second column shows the charging tariff to be used for the location in the first column.
TABLE 1
Location/Charging
Charging tariff
LAI-1
Tariff 1
LAI-2
Tariff 2
SAI-1
Tariff 3
CT-x
Tariff 4
CGI-1
Tariff 5
The different possible entries are Service Area Identity (SAI), Location Area Identity (LAI), Cell Global Identity (CGI) or any parts of these and Charging Type (CT). The CT indication means that current RAN (e.g. GAN, Femto) contains the logic needed to select a charging tariff for the end user and this selection is transferred from the RAN to the CN as a CT information. The CT indication could in the simplest form be of the type defining the current access being used, e.g. GAN, Femto GSM, Femto WCDMA. In addition, the CT indication could contain information on more detailed level also based on the current AP being used in the GAN or Femto solutions. In this case, the indication could for example be that a “Home AP” is being used or that an “Office AP” is being used. Other possibilities are obvious and depend on the information configured in the RAN. Some further examples are e.g. “Visitor on an AP” and “Hotspot AP” being used. The CT solution means that the relevant signaling needs to be enhanced for example in the A interface for the BSSMAP protocol as defined in 3GPP TS 48.008. The relevant messages where the CT indication could be added are in the exemplary A interface case are the COMPLETE LAYER 3 INFORMATION, HANDOVER REQUEST ACK and HANDOVER PERFORMED. The other interfaces like lu and Gb can be extended with similar mechanisms. The MSC/VLR 108 , 109 is configured to check the location and charging information in the table 1 to decide if a specific tariff should be indicated with respect to the current network of the called terminal towards the network from where the call was initiated.
The tariff, i.e. Tariff 1 - 5 in this embodiment, may be a numeric value indicating a specific tariff or e.g. a prefix or whole telephone number that is to be used to create a generic or connected number. Although the table has 5 locations/charging types and 5 tariffs, the table may include fewer or more locations/chargings and tariffs in one or more embodiments. The tariffs do not necessary have to be different for different locations/chargings, but may of course be the same for one or more locations/chargings.
User- 2 of terminal 105 is connected via GAN 112 access in PLMN- 1 101 in step 1 . User- 3 of terminal 106 in PSTN- 1 102 initiates a call towards user- 2 of terminal 105 in step 2 and the call is forwarded through PLMN- 1 101 according to known principles. Hence, an IAM message with the called party=user- 2 MSISDN is sent from the PSTN- 1 102 to the GMSC 111 in PLMN- 1 101 in step 3 . In step 4 , the MSISDN of user- 2 of terminal 105 is forwarded in an Send Routing Information (SRI) message to the HLR 110 , which sends an Provide Routing Number (PRN) message with the IMSI of the user- 2 of terminal 105 to the MSC/VLR 108 , 109 in step 5 . The MSC/VLR 108 , 109 acknowledges with a PRN ACK(MSRN) message to the HLR 110 in step 6 , the content of which is forwarded in an SRI ACK(MSRN) message to the GMSC 111 in step 7 . The GMSC 111 then sends an IAM(MSRN) message to the MSC/VLR 108 in step 8 as it has received the needed information from the HLR in the SRI ACK(MSRN) message.
In response to the received IAM(MSRN) message, the MSC/VLR 108 , 109 pages the terminal of user- 2 of terminal 105 via GAN 112 access in step 9 using existing principles and methods. The terminal of user- 2 of terminal 105 replies with a paging response to the GAN 112 which forwards complete layer 3 information with cell global identity (CGI) and paging response to the MSC/VLR 108 , 109 in step 11 .
The MSC/VLR 108 , 109 checks the location and charging information in the table 1 in step 12 to decide if a specific tariff should be indicated towards the network PLMN- 1 101 where the call was initiated from. As the MSC/VLR 108 , 109 may be configured with specific tariff information in the table 1 for the current cell of the user- 2 of terminal 105 , the MSC/VLR 108 , 109 informs the PSTN- 1 about the specific charging in step 13 .
Once the MSC/VLR has found out the charging tariff by accessing the table 1 to be indicated towards the originating network, there may be at least two ways to send the indication, which is illustrated in FIG. 3 .
According to a first alternative 1 , the MSC/VLR 108 , 109 sends a Charge Information (CRG) ISUP message (CRG has so far been defined for national use but could in this case be used between any types of networks) to the originating network in step 13 a as soon as it has found out that a specific tariff needs to be applied and is allowed according to the call states (e.g. after ACM, Address Complete). The new tariff is indicated e.g. in the Tariff Indicator field in the message.
According to a second alternative 2 , the terminating call is established between the user- 2 of terminal 105 and the MSC/VLR 108 , 109 in step 159 using existing principles and methods. Once this is done, i.e. the MSC/VLR receives a Connect message from the terminal 105 in step 15 , the MSC/VLR 108 , 109 sends an Answer (ANM) ISUP message (e.g. after ACM, Address Complete) or the Connect (CON) ISUP message to the originating network PSTN- 1 102 in step 13 b . This message contains the Generic or Connected Number that indicates e.g. a fixed terminating domain.
Both the steps 13 a and 13 b corresponds to the step 13 in FIG. 2 . Obviously the step 13 b happens later in the signaling flow as it takes place first after the call establishment but it corresponds to the step 13 as the charging indication is provided first at this stage.
If the Connected Number is used then the Address presentation restricted indicator could be set to “Presentation not allowed” or the originating network supporting this new functionality could remove parameters including the number used for the charging indication to avoid displaying on the end user terminal if this is desired.
The method is not limited to the embodiment described herein, but different combinations of the mechanisms shown in FIG. 3 can be applied simultaneously.
Additionally, an indication about the access network used on the B-side, i.e. GAN in this embodiment, may be provided to the calling subscriber from the network on the B-side, i.e. PLMN- 1 101 in this example. This indication could be e.g. a voice message that is played to the calling subscriber. A similar indication could also be provided on the A-side, i.e. PSTN- 1 102 in this example.
The reason for the access network indication, i.e. instead of a charging indication from the network on the B-side, i.e. PLMN- 1 101 in this embodiment, is that the network on the A-side, i.e. PSTN- 1 102 in this embodiment, decides the charging to be applied and the B-side network will not normally know the exact tariff.
The originating network receives the indication about the new charging, and in response, the originating network, i.e. PSTN- 1 102 , changes the charging dependent on the current terminating network in step 14 .
Depending on which type of charging is applied (i.e. non-Real-time or Real-Time charging), the originating network takes actions. For non-Real-time charging it may be sufficient to include the received charging information (i.e. Tariff Indicator, Generic Number or Connected Number) in the charging output records. For Real-time charging it may be sufficient to forward the received charging information (i.e. Tariff Indicator, Generic Number or Connected Number) towards the node handling Real-time charging.
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention, which fall within the scope of the invention. However, although embodiments of the method and apparatus of the invention has been illustrated in the accompanying drawings and described in the foregoing detailed description, the disclosure is illustrative only and changes, modifications and substitutions may be made without departing from the scope of the invention as set forth and defined by the following claims.
In some embodiments the PLMN- 1 uses some internal tariff indications inside the PLMN- 1 and then the GMSC changes the information depending on which network originated the call. In this case the GMSC contains the needed mapping tables from the internal tariffs towards operator-specific and agreed values.
For example in alternative 1 described with reference to FIG. 3 , this means that the MSC 108 sends the CRG-message containing a value X towards the GMSC 111 . The GMSC 111 performs the needed mappings towards different operators. For PSTN- 1 102 the value X is mapped to a value Z and if the call was originated from PLMN- 2 103 , the value X may be mapped to e.g. a value Y.
Similar actions may be taken for the alternative 2 described with reference to FIG. 3 , i.e. that the whole or parts of the Generic or Connected Number is mapped depending on the operator “on the other side”.
The embodiments have been described above in conjunction with a call scenario, wherein the user- 3 of terminal 106 in PSTN- 1 calls the user- 2 of terminal 105 in PLMN- 1 101 . This is only one example of a call scenario illustrating advantage embodiments and it is not intended to limit the scope of the invention. The following call scenarios are further examples illustrating the advantages of the method an apparatus of the invention, wherein differentiated tariffs or charging is used depending on the access network of a called mobile communication apparatus. User- 3 in PSTN- 1 calls user- 2 in Femto GSM part of PLMN- 1 . User- 4 in e.g. macro GSM part of PLMN- 2 calls user- 2 in GAN or Femto GSM part of PLMN- 1 .
However, in case user- 3 in PSTN- 1 calls user- 1 in macro GSM part of PLMN- 1 or user- 4 in e.g. macro GSM part of PLMN- 2 , the call may be charged as today using existing mechanisms in PSTN- 1 . In case users in e.g. macro GSM part of PLMN- 2 calls user- 1 in macro GSM part of PLMN- 1 , the call may be charged as today using existing mechanisms in PLMN- 2 .
Other differentiated services than differentiated charging is also possible within the scope of the invention.
Although the embodiments of the MSC/VLR described with reference to the drawings comprise a computer apparatus and processes performed in the computer apparatus, the invention also extends to programs on or in a carrier, adapted for putting the invention into practice when the computer program is executed. The program may be in the form of source code, object code a code suitable for use in the implementation of the method according to the invention. The carrier can be any entity or device capable of carrying the program. For example the carrier may be a record medium, computer memory, read-only memory or an electrical carrier signal.
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A method and a mobile services switching center of providing differentiated services in a communications network. The method comprises receiving in a mobile services switching center an indication message from a first radio access network, said message indicating a radio access network type to which a called communication apparatus of a terminating communication session is connected, in response to the indication message: accessing differentiated service information associated with the radio access network type of the terminating communication session, and sending the differentiated service information to be applied for service differentiation by a second access network of calling communication apparatus.
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RELATED APPLICATIONS INFORMATION
This application claims the benefit under 35 U.S.C. 119 (e) to U.S. Provisional Patent Application Ser. No. 60/871,273, filed Dec. 21, 2006, and entitled “Method and Apparatus for RFID Enabled Metal License Plates”, which is incorporated herein by reference in its entirety as if set forth in full.
BACKGROUND
1. Field of the Invention
The embodiments described herein relate generally to electronic vehicle registration and tracking systems, and more particularly to the use of Radio Frequency Identification (RFID) in such systems.
2. Background of the Invention
RFID technology has long been used for electronic vehicle tolling applications. In such applications, an RFID reader or interrogator is position over or near a road way at a point where a toll is to be collected. An RFID tag is then place in each vehicle that includes an identifier by which the vehicle can be recognized, e.g., the vehicle's license plate number. The interrogator then uses RF signals to interrogate the tag and obtain the identifier so that the toll can be applied to the correct vehicle, or account.
Generally, the tag to interrogator communication is achieved through a form of modulation known as backscatter modulation. In a backscatter modulation system, the tag does not generate its own RF carrier signal when transmitting information to the interrogator. Rather, the interrogator generates an RF carrier and modulates the carrier with data intended for the tag, e.g., a request for the tags identifier information. The tag receives the modulated signal decides the data and then performs actions in accordance therewith e.g., accesses the memory and obtains the requested identifier information. The interrogator continues to transmit the RF carrier, now with no data on it. The tag receives this un-modulated carrier and reflects it back to the interrogator. This is called backscatter. In order to send data back to the interrogator, e.g., identifier, the tag modulates the reflected, or backscatter signal with the data.
For example, the tag will alternately backscatter and not backscatter the RF carrier signal for a certain period of time in order to transmit a digital “0” an “1” respectively. Thus, the tag modulates the backscatter signal by reflecting or not reflecting the signal based on the data, i.e., “1s” and “0s,” to be sent. The interrogator receives the modulated backscatter signal and decodes the information received thereon.
Early on, such tags were active device, meaning they possessed their own power source, such as a battery. An active tag was necessary, for example, in order to generate enough power in the reflected signal to transmit information over extended distances. But more recently, passive tag technology has become more viable. A passive tag does not include a battery or power source of its own. Rather, energy in the RF signals received from the interrogator is used to power up the tag. For example, the received RF signal can be rectified and used to charge up a capacitor that is then used to power the tag.
As antenna and integrated circuit technology has evolved, larger and larger distances can be achieved with passive tags of smaller and smaller dimensions. Accordingly, small, thin, light weight tags can be used in a wide variety of applications. Often these tags are referred to as sticker tags or RFID labels, because of their dimensions and the fact that they can be manufactured to include an adhesive layer so that they can be applied to the outside of containers, the surface of documents, inventory, etc. In other words the tags can be applied like a label or sticker.
The emergence of passive, sticker tag technology has also greatly reduced the cost of implementing an RFID system. As a result, new applications, such as Electronic Vehicle Registration (EVR) using RFID, have emerged. Currently, e.g., in the United States, a vehicle owner registers their vehicle with the State government and pays a fee. The owner is then provider a sticker, which is applied to the vehicle license plate, to evidence the valid registration of the vehicle; however, these stickers can easily be counterfeited or stolen, i.e., removed and applied to another vehicle. Such activity is difficult to detect, because the only way to determine that a registration sticker does not belong on a certain vehicle is to access a database and check the corresponding information.
For example, in the United States, an estimated five to ten percent of motorists fail to legally register their vehicles, resulting in lost annual state revenues of between $720 million and $1.44 billion. Outside of the United States, some government agencies report the problem at 30-40% of the vehicles.
Deploying an Electronic Vehicle Registration system can help Motor Vehicle Administrators achieve increases in vehicle compliance and associated revenues by eliminating the need to rely on inefficient, manual, visual-based compliance monitoring techniques. EVR uses RFID technology to electronically identify vehicles and validate identity, status, and authenticity of vehicle data through the use of interrogators and tags that include data written into the tag memory that matches the vehicle registration data. Fixed, e.g., roadside, or handheld interrogators can then be used to read the data out when required. Thus, RFID technology can enable automated monitoring of vehicle compliance with all roadway usage regulations, e.g., vehicle registration, tolling, etc., through a single tag.
There are two common ways of attaching a RFID tag to a vehicle, one is using an RFID label tag attached to the windshield of the vehicle. The tag can then be read by a roadside or handheld reader. A second method of attaching the tag to a vehicle is to embed the RFID tag into the license plate. This has the convenience an continuity of replicating the application of current registration stickers; however, such a solution can also suffer from reduced transmission, i.e., communication distance due to the effects the metal license plate has on the performance of the tag antenna.
For example, as illustrate in FIG. 1 , a RFID tag 100 consisting of a RFID chip 102 and an antenna 104 can be mounted on the vehicle license plate 110 . As mentioned, however, license plate 110 is usually made from metal. As a result, the tag information may not be readable due to the shielding effects of metal surrounding tag 100 . Moreover, if tag 100 is directly applied to the metal surface of license plate 110 , then tag antenna 104 can be shorted or severely detuned by the metal surface. As a result, tag 100 will not be read, or will only be readable at very short distance.
A conventional approach to overcoming this issue is to leave some spacing 202 between tag 100 and metal license plate 110 as shown in FIG. 2 . Such a solution has an added benefit in that metal license plate 110 can also serve as a back plane for tag antenna 104 . For example, as illustrated in FIG. 3 , an RFID tag 100 can be housed within an non-metal enclosure 302 , e.g., formed from a low dielectric material that includes a spacer 304 such as an air gap or foam material.
One problem with such a conventional solution is the increased dimension, i.e., thickness of the resulting license plate assembly. Accordingly, conventional approaches force a tradeoff between reduced performance, or increased size and dimensions, which can have a negative impact.
SUMMARY
In the embodiments described herein, a RFID enabled license plate is constructed by using the license plate, or a retro-reflective layer formed thereon as part of the resonator configured to transmit signals generated by and RFID chip integrated with the license plate.
For example, in one aspect, such an RFID enabled license plate can include a metal license plate with a slot formed in the metal license plate, and a RFID tag module positioned in the slot. The RFID tag module can include a chip and a loop, and the loop can be coupled with the metal license plate, e.g., via inductive or conductive coupling. In this manner, the metal license plate can be configured to act as a resonator providing increased performance.
In another aspect, the RFID tag module can be positioned substantially within the slot such that the addition of the RFID tag module does not increase the thickness of the license plate.
In still another aspect, the RFID enabled license plate can comprise a RFID tag module, positioned in the slot, which includes a chip and contacts. The contacts connected with the metal license plate, e.g., via a conductive paste or a solder connection.
In still another aspect, the RFID enabled license plate can comprise a license plate and a retro-reflective layer formed over the license plate. A slot can then be formed in the retro-reflective layer, and a RFID tag module can be positioned in the slot. The RFID tag module can include a chip and a loop, and the loop coupled with the retro-reflective layer, e.g., via inductive or conductive coupling.
In still another aspect, the RFID enabled license plate can include a retro-reflective layer formed over the license plate and a slot formed in the metal license plate. A RFID tag module can be positioned in the slot. The RFID tag module can comprise a chip and contacts, and the contacts connected with the metal license plate, e.g., via a conductive paste or a solder connection.
These and other features, aspects, and embodiments of the invention are described below in the section entitled “Detailed Description.”
BRIEF DESCRIPTION OF THE DRAWINGS
Features, aspects, and embodiments of the inventions are described in conjunction with the attached drawings, in which:
FIG. 1 is a diagram illustrating an exemplary license plate comprising an RFID module;
FIG. 2 is a diagram illustrating a side view of the license plate of FIG. 1 ;
FIG. 3 is a diagram illustrating a RFID module that can be used in conjunction with the license plate of FIGS. 1 and 2 ;
FIGS. 4A and 4B are diagrams illustrating an example RFID enabled license plate in accordance with one embodiment;
FIGS. 5A and 5B are diagrams illustrating methods for coupling an RFID module with the license plate of FIGS. 4A and 4B ;
FIGS. 6A-C are diagrams illustrating an example RFID enabled license plate in accordance with another embodiment;
FIGS. 7A-C are diagrams illustrating example RFID enabled license plate in accordance with another embodiment;
FIG. 8 is a diagram illustrating another example RFID enabled license plate in accordance with another embodiment; and
FIG. 9 is a diagram illustrating another example RFID enabled license plate in accordance with another embodiment.
DETAILED DESCRIPTION
The embodiments described below are directed to system and methods for a RFID enabled license plate in which a metal layer of the license plate is actually used to radiate backscattered energy generated by a RFID tag positioned within a slot created in the license plate. Accordingly, not only does the metal license plate not interfere with the operation of the tag, it actually assists.
Certain embodiments described herein are directed to methods for creating an antenna structure directly on (1) a metal license plate, (2) a metalized retro-reflective foil covering a non-metal license plate, or (3) a metalized retro-reflective foil covering the metal license plate. Depending on the embodiment, the RFID chip can be directly connected to or electrically coupled, either capacitive or inductively, with the antenna structure. The antenna structure can be a single or multi-frequency resonant structure.
FIG. 4 , comprising FIGS. 4A and 4B , is a diagram illustrating an example license plate 400 comprising an RFID tag in accordance with one embodiment. As shown in FIG. 4A , license plate 400 can comprise an open area, or slot 402 . For example, slot 402 can be cut into metal license plate 400 . Alternatively, slot 402 can be punched out of plate 400 . As shown in FIG. 4B , a RFID tag module 406 comprising an enclosure around tag 404 can then be positioned within slot 402 . The dimensions of slot 402 and module 406 can be designed such that module 406 fits within slot 402 creating a substantially planar surface with the surface of metal license plate 400 . It should be noted that the top of module 406 is shown extending beyond the surface of license plate 400 in FIG. 4B , creating a non-planar surface; however, this is purely for illustration. In practice, module 406 can be made extremely thin allowing for a substantially planar surface across all of plate 400 , including slot 402 , even when module 406 is installed therein.
For example, module 406 can be similar to the module illustrated in FIG. 3 . Thus, module 406 can include an enclosure if required. Module 406 can then be configured to include a feeding loop that can couple tag 404 with metal license plate 400 . In this manner, the entire license plate 400 can then serve as an effective radiator via inductive coupling through the feeding loop.
FIGS. 5A and 5B illustrate two example implementations of the embodiment illustrated in FIG. 4 . In FIG. 5A , module 406 comprises a chip 502 coupled with a feeding loop 504 . Slot 402 is then positioned such that feeding loop 504 will be inductively coupled with metal license plate 400 . In FIG. 5B , slot 403 is positioned such that feeding loop 504 is capacitively coupled with metal license plate 400 .
Further, in certain embodiments, the radiation gain can be enhanced by using the metallic car frame (not shown). For example, with a properly designed tag antenna and proper consideration of the spacing between the metallic car frame and license plate 400 , the metal car frame can be used as a good antenna reflector.
In another embodiment, a structure very similar to Planar Inverted-F Antenna (PIFA) can be implemented by screwing the license plate directly to the metallic car frame as illustrated in FIG. 6 . In FIG. 6 , which comprises FIGS. 6A-C , metallic screws serve as shorting posts 602 and metallic car frame 600 serves as a ground plane for the antenna of tag module 406 .
FIG. 7 , comprising FIGS. 7A , 7 B, and 7 C, is a diagram illustrating an example of a license plate 700 configured to incorporate an RFID tag in accordance with another embodiment. As shown in FIG. 7A , an area, or slot 702 is cut, or punched, etc., in license plate 700 . As shown in FIG. 7B , a non-metal material 704 can then be inserted into slot 702 such that both the front and rear surfaces of license plate 700 are flat. Material 704 can be stuffed, extruded, etc., into slot 702 . As shown in FIG. 7C , an RFID “strap” comprising a chip 708 with contacts 710 can then be positioned over slot 702 as illustrated. Contacts 710 can then be connected to or capacitively coupled with metal license plate 700 . Depending on the embodiment, strap 712 can be placed on either the front surface or the rear surface of the license plate. The entire license plate 700 then becomes a slot antenna coupled with the RFID chip, which is less sensitive to the metallic car frame in terms of tag antenna detuning effect. Contacts 710 can be soldered to plate 700 , adhered using a conductive paste, or both.
It should also be noted that strap 712 can be made extremely thin, such that the surface of license plate 700 is substantially planar.
In certain embodiments, the dimensions of slot 702 can be altered, or multiple slots included to create a dual or multiple resonance frequency slot antenna. In such configurations, the tag will respond to multiple frequency bands, such as the Ultra High frequency (UHF) band, e.g., 900 MHz, and the microwave band, e.g. 2.45 GHz. This can allow multiple application capability. For example, depending on the application, one frequency band can be preferred for its localization characteristics and another frequency band can be preferred for its long range read capabilities. More specifically, a higher frequency band, such as a 2.45 GHz band, can be used for write applications as its limited range helps insure only the tag of interest is written to, while a lower frequency band, such as a 900 MHz band, can be used for multi-tag read applications as its greater range allows many tags to be read over a large area. In other embodiments, multiple frequency bands can be needed due to regulatory requirements that can vary the authorized frequency band based on locations, e.g., country, city, etc., and by application.
FIGS. 8 and 9 are diagrams illustrating example multi-frequency RFID license plates in accordance with two example embodiments. In FIG. 8 , two slots 802 and 804 are formed in metal license plate 800 . A strap 806 is then positioned across slot 806 as illustrated. The two slots 802 and 804 are configured, with respect to dimensions, spacing, location, etc., such that the slot antenna formed from license plate 800 , slots 802 and 804 and strap 806 will resonate at the desired frequencies, e.g., the UHF and microwave bands.
In FIG. 9 , two slots 902 and 904 are formed in license plate 900 ; however, in this example, slots 902 and 904 are connected via slot 906 . A slot 910 then extends to the edge of plate 900 . Strap 908 is then positioned across slot 910 as illustrated. Again, slots 902 , 904 , 906 , and 910 are configured such that the resulting slot antenna resonates at the desired frequencies.
The slots of FIGS. 8 and 9 can be filled with non-metallic material as in the example of FIG. 7 depending on the embodiment. Further, certain parasitic elements can be included, or changed to achieve the proper multi-frequency operation. It should also be noted that the embodiments of FIGS. 4 and 5 can also be configured as multi-frequency resonant structures via the inclusion of further slots appropriately constructed so as to allow the structure to resonate at the desired frequencies.
It will be understood that other slot dimensions, locations, spacing, interconnectedness, etc., are possible and will depend on the requirements of a particular implementation. Similarly, the position of the strap comprising the chip and connectors can vary as required by a particular implementation. Accordingly, the specific implementations illustrated herein should not be seen as limiting the embodiments disclosed to any particular configuration.
It will also be understood that the impedance of the resulting antenna structure in the above embodiments will need to be matched to that of the chip. This can impact the slot dimensions, etc. It can also require additional circuit elements, i.e., the inclusion of a matching circuit.
A retro-reflective film can be used to cover the front surface of the license plate. Such a film can make the license plate modification invisible from front view; and can also makes the license plate viewable in dark lighting. If the retro-reflective film contains metal materials, e.g., a metallized polymer film, then a selective metal removal process can be applied such that the film area covering the open area in the license plate is de-metallized. Such a de-metallization is described in detail in co-owned U.S. Pat. No. 7,034,688, as well as Co-owned patent application Ser. No. 10/485,863, each of which are incorporated herein by reference as if set forth in full. In other embodiments, the antenna structure can actually be formed on a retro-reflective layer that is then applied to a non-metallic, or metallic, license plate.
While certain embodiments of the inventions have been described above, it will be understood that the embodiments described are by way of example only. Accordingly, the inventions should not be limited based on the described embodiments. Rather, the scope of the inventions described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.
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In the embodiments described herein, a RFID enabled license plate is constructed by using the license plate, or a retro-reflective layer formed thereon as part of the resonator configured to transmit signals generated by and RFID chip integrated with the license plate. Such an RFID enabled license plate can include a metal license plate with a slot formed in the metal license plate, and a RFID tag module positioned in the slot. The RFID tag module can include a chip and a loop, and the loop can be coupled with the metal license plate, e.g., via inductive or conductive coupling. In this manner, the metal license plate can be configured to act as a resonator providing increased performance.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 10/704,314, filed Nov. 7, 2003.
BACKGROUND OF THE INVENTION
[0002] The proliferation of computers and the Internet have changed the way average consumers buy, store and listen to music. It is no longer necessary to buy complete albums or to have songs stored on medium such as CDs. It is possible to download songs from the Internet and store them digitally on devices such as MP3 players.
[0003] The digital storage of songs allows listeners to store individual songs from various artists together. Without being confined to CDs having a specific song order, users are free to create different song orders from the catalog of songs stored on the MP3 player.
[0004] Greater freedom in digitally stored songs have allowed the average person to mix together phrases of songs. While this amount of interaction by listeners with songs if desirable, it is often time consuming and beyond the abilities of an average listener.
[0005] As the music industry has embraced the new matter in which songs are distributed and sold to the ultimate consumer, piracy and unauthorized copying of songs has long been a concern. The technology of making such transfer of songs possible also increases the ease in which copyright infringement occurs. A secure format preventing piracy would be welcomed by the music industry.
[0006] It is an object of the invention to provide listeners with a system and method for allowing interaction with commercially recorded music.
[0007] It is another object of the invention to provide a method for listeners to assemble audio and visual clips in any manner, being able to reuse clips in different arrangements.
[0008] It is still another object of the invention to empower a user will limited musical and computer skills to create blends of two or more musical tracks.
[0009] These and other objects of the invention will become apparent to one of ordinary skill in the art after reading the disclosure of the invention.
SUMMARY OF THE INVENTION
[0010] A digital interactive phrasing (DIP) system allows listeners to select and edit digitally prepared elements, such as audio or video clips, in any arrangement to create a custom mix. The elements may be reused to make new, different arrangements, as desired by the listener. The system allows the selection, assembly and playback of created sequences of elements, such as songs, verses, dialogs and video elements.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Original source material is divided into pre-edited, digitally prepared elements arranged in a coded sequence. The elements are stored in memory, such as a computer hard drive or a removable storage device such as a CD, for future reassembly. The elements have a file main portion with a tag at the beginning and ending. The tag allows the central processing unit to identify the beginning and end of each element so elements may be mixed together.
[0012] A computer accesses the elements from the databases where they are stored. Each element can be mixed with other elements in the DIP format. The tag locates a point at which one element is spliced with another element. The splice may be a fade where the first element is faded out while the second element is faded in. The splice may also be a seamless transition. Any variety of transition affects can be used and included in the preparation and editing of the element.
[0013] In one simple application, a listener is able to mix studio and live versions of a song from one artist. However, it is not unusual for a single form to be recorded by different artists at different times. Using the system, different versions of the same song may be woven together to create a hybrid. Likewise, a medley of different songs by the same or different artists can be woven together to create an entirely new song.
[0014] A musical phrase or verse is segmented into audio phrases and assigned codes. The visual interpretation of how phrases are digitally stored are shown in the following Tables:
[0000]
TABLE I
Ver
Ver
Ver
A
B
C
Pre-edited Phrases
A1
B1
C1
Yesterday
A2
B2
C2
All my troubles seem so far away
A3
B3
C3
Now looks as though they are here to stay
[0000]
TABLE II
Ver
Ver
Ver
A
B
C
Pre-edited Phrases
A1
B2
n/a
Yesterday
A2
B2
C2
Random Verse 1
A3
B3
n/a
Now looks as though they are here to stay
A4
B4
C4
Random Verse 2
A5
B5
n/a
Oh I believe, in Yesterday
[0000]
TABLE III
Ver
Ver
Ver
A
B
C
Pre-edited Phrases
A1
B2
n/a
Yesterday
A2
B2
C2
TV Clip 1
A3
B3
n/a
Now looks as though they are here to stay
A4
B4
C4
TV Clip 2
A5
B5
n/a
Oh I believe, in Yesterday
[0015] Table I illustrates the simple scenario of mixing different version of the same song. The user can easily mix the phrases from the different versions to create a new song. For instance, the use can make a version that is A1 B2 A3 or C1 A2 B3, and continuing to pick versions of each phrase until the song is complete. By having the phrases preset, the user can quickly and easily string the phrases together, without needing to determine where each phrase should begin and end. Each song would have its own alphanumeric code so as to be enable users to quickly find songs.
[0016] Table II exemplifies the mixing of disparate songs. Again the user is able to string together various phrases of different songs to create an entirely new song. The songs may be combined based on their similar theme or subject matter or because they have the same rhythm, tempo or melody. This allows the combination of any number of songs or even the insertion of a few phrases into a song. In a similar situation, video clips can be added to songs, as depicted in Table III. The video clips, like the audio clips, are pre-edited and stored as a file main portion with a tag at the beginning and ending.
[0017] The invention allows the easy mixing of elements to create new versions of one songs or the conglomeration of different songs in any order the user desires. Every song or video is pre-edited into elements forming blocks that can be combined. Once the elements are chosen, a file can be created. The file may be the elements themselves or the codes for the elements. In the latter case, the computer reads the codes and retrieves the elements to play the file. The invention can be performed in a procedure as follows:
[0018] 1) The user inserts two CDs into a suitable device, such as a DSP digital signal processor;
[0019] 2) User selects two or more tracks to be mixed;
[0020] 3) The device recognizes the title/artist/track selection from encoding on the CD;
[0021] 4) The device creates a code file in the data base;
[0022] 5) The user initiates playback of a track in it entirety while viewing the corresponding code on the consumer interface while pre-annotated elements are being played;
[0023] 6) User repeats the above step for the second (and each additional) track;
[0024] 7) The user selects sequence of alternating selective playback by pushing buttons corresponding to codes (ie. A1 B2 B3 etc.)
[0025] 8) User initiates selective playback by pressing a “Blend” button;
[0026] 9) User preserves mix by pressing a “File” button to create file with artist/track date stamped and the corresponding selected codes;
[0027] 10) User listens to selective alternating playback sequence or pre-annotated elements while viewing associated codes on consumer interface (LCD);
[0028] 11) Option of pressing a “Random” button to create random mix of two tracks;
[0029] 12) Save random mix as in step 9
[0030] 13) Listen to random mix as in step 10
[0031] 14) Equipment may have remote control
[0032] 15) May mix tracks from same CD.
[0033] While the invention has been described with reference to preferred embodiments, variations and modifications would be apparent to one of ordinary skill in the art without departing from the spirit of the invention. The invention encompasses such variations and modifications.
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A digital interactive phrasing (DIP) system allows listeners to select and edit digitally prepared elements, such as audio or video clips, in any arrangement to create a custom mix. The elements may be reused to make new, different arrangements, as desired by the listener. The system allows the selection, assembly and playback of created sequences of elements, such as songs, verses, dialogs and video elements.
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FIELD OF THE INVENTION
This invention relates to dispensing apparatus for use in the medical field, and more particularly but not exclusively to apparatus for dispensing potentially biologically damaging substances.
In many hospitals large numbers of doses containing potentially biologically damaging substances have to be prepared daily, for example radiopharmaceutical doses. These doses are usually prepared manually in what is an exacting but tedious responsibility for highly skilled staff. It is, therefore, an object of the invention to provide an automated dispenser to simplify the manual operations necessary for preparing doses containing potentially biologically damaging substances whilst maintaining the exacting standards set by medical regulatory bodies.
BACKGROUND AND SUMMARY OF THE INVENTION
According to the present invention there is provided a dispensing apparatus comprising a robot device having gripping means presentable to a plurality of stations, each station being adapted to cooperate with the robot device in a sequence of operations such as to produce a measured pharmaceutical dose from a supply of a pharmaceutically acceptable substance, and one of the stations comprising means for locating in parallel a plurality of medical hypodermic syringes for containing a said substance and for operating a said syringe.
The substance might comprise a potentially biologically damaging substance, such as a radionuclide or a cytotoxin. The measured dose might be retained in a said syringe, or in a medical vial.
Preferably, means are provided for controlling the apparatus in a predetermined sequence of operations.
DESCRIPTION OF THE DRAWINGS
The invention will now be a further described by way of example only with reference to the accompanying drawings in which:
FIG. 1 shows a perspective diagrammatic representation of a dispensing apparatus;
FIGS. 2 to 5 shown in median section a conventional hypodermic syringe and items associated therewith;
FIG. 6 shows to an enlarged scale a median sectional view of a vial shield containing a medical vial;
FIG. 6a shows a fragmentary view in the direction of arrow `A` of FIG. 6;
FIG. 6b shows a fragmentary view of a modification to the vial shield of FIG. 6;
FIG. 7 shows a plan view to an enlarged scale of jaws for the apparatus of FIG. 1;
FIG. 8 shows a view on the line VIII--VIII of FIG. 7;
FIG. 9 shows a front view in part section and to an enlarged scale of a syringe operating assembly for the apparatus of FIG. 1;
FIG. 10 shows a view on the line X--X of FIG. 9, and
FIG. 11 shows to an enlarged scale a view in the direction of arrow `B` of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, an automatic dispenser 10 is shown, and comprises a base 12 having thereon an industrial robot device 14 rotatable on a plinth 16 mounted on the base 12 and controlled by a controller 17. The robot device 14 has articulated arms 18, 19, and gripping means in the form of jaw members 20a, 20b having respective depending tangs 21a, 21b at a rotatable wrist element 22 of the arm 18.
The robot device 14 is arranged to present the jaw members 20a, 20b at a number of stations in the form of: radioisotope generators 26, 28 respectively, a monitor assembly 30, a multi-syringe operating assembly 32 (shown only in phantom outline), a waste outlet 34, and trays 36 for holding items to be handled by the dispenser 10.
The generators 26, 28 are proprietary items supplied by companies such as Amersham International, Amersham, United Kingdom, or Dupont, or Mallinkrodt, for the supply of a specific radioisotope, e.g. Technetium 99 m, Thallium, Gallium, or Iodine 131 . Each generator 26, 28 has respective needle-type socket connectors 42, 44, and rotary control valves 43, 45, and usually the generators 26, 28 are arranged so that they supply the radioisotope at different radioactive decay states.
A suitable robot device 14 is that manufactured by: CRS Plus Inc 830 Harrington Court, Burlington, Ontario, Canada L7N 3N4, and distributed in the United Kingdom by: Affordable Automation Ltd, P.O. Box 31, Eccles, Manchester, M30 7QB.
Referring now to FIGS. 2 to 6b various items are shown to be handled by the dispenser 10, namely a hypodermic syringe 48 having a plunger 48a, hypodermic needles 49 for the syringes 48, sheaths 50 for the needles 49, medical hubs 53 for fitting on to the end of the syringes 48 without the needles 49 thereon, and vial shields 54. Each vial shield 54 comprises a pot 56 having a cap 58 secured by a bayonet-type catch 60 to the pot 56, and arranged to contain a conventional medical vial 62.
The cap 58 has parallel grooves 59 with inward wedge-shaped faces 59a which complement the shape of the jaws 20a, 20b. A hole 69 in the cap 58 allows access to a rubber sealing plug 70 retained by a captive metal cap 71 in the vial 62. Two peripheral grooves 72 in the side of the vial shield 54 assist in handling of the vial shields 54 by the jaws 20a, 20b, and two pins 73 in each groove 72 (see FIG. 6a) assist retention of the jaws 20a, 20b. Two slots 74 on a common diameter extend from either side in the base of the vial shield 54 to locate corresponding pins 74a in holes 39 in some of the trays 36 (see FIG. 11). The vial 62 might be an empty bottle, or a bottle containing a powder intended to dissolve in a liquid injected into the bottle, or a bottle containing a medical saline solution. The vial shield 54 is preferably stainless steel, but might be lead with a protective coating. An alternative vial shield 54a (see FIG. 6b) for monitoring for molybdenum is similar to the vial shield 54 except that the hole 69 is omitted and a handle 75 provided.
Referring again to FIG. 1, the monitor assembly 30 comprises a recessed slide 78 having a lower platform 79, and an intermediate support 82 having a slot 84 to locate one of the syringes 48. The slide 78 is joined at its upper end to a table 86 located on guide rods 87, and arranged to be moved vertically by a lead screw 88. The lead screw 88 is operated by a motor 89 so as to lower the slide 78 into a conventional lead shielded, radioactivity detector (not shown) below the table 12.
A preferred form of the jaws 20a, 20b is shown in FIGS. 7 and 8. The jaw members 20a, 20b, have inwardly shaped ends 90a, 90b with opposing V-shaped grip portions 91a, 91b. The depending tangs 21a, 21b have inwardly formed ends 92a, 92b with opposing V-shaped grip portions 93a, 93b. Holes 73a, 73b in the jaws 20a, 20b respectively are arranged to locate the pins 73 of the vial shields 54, 54a, and the outer edges of the grip portions 91a, 91b are arranged to fit into the grooves 59 of the vial shields 54, 54a.
A preferred multi-syringe operating assembly 32 is shown in FIGS. 9 and 10 to which reference is made. The assembly 32 is arranged to locate three syringes 94a, 94b, 94c respectively of different capacities on slotted lower shoulders 96a, 96b , 96c where they are retained by slotted upper shoulders 98a, 98b, 98c respectively. Plungers 95a, 95b, 95c of the syringes 94a, 94b, 94c respectively locate on lower slotted tangs 100a, 100b, 100c and are retained by upper tangs 102a, 102b, 102c respectively. The body of the syringes 94a, 94b, 94c extend through respective slots 104a, 104b, 104c in a block 106 secured to an upright wall 108. The lower shoulders 96a, 96b, 96c and the upper shoulders 98a, 98b, 98c are secured to the block 106 through upright support rods 110. The lower tangs 100a, 100b, 100c and the upper tangs 102a, 102b, 102c are supported from one side of an upright plate 112 mounted on linear bearings 114 that slide on two parallel columns 116 supported by the wall 108. An offset arm 118 from an outermost linear bearing 114 extends through an elongate slot 119 in the wall 108, and locates in engagement with a lead screw 120 driven by a motor 124 supported on a bracket 122 from the wall 108 so as to raise and lower the plate 112. A platform 130 has three recessed bases 132a, 132b, 132c respectively to locate vial shields 54 or vials 62, and is shaped to define an upright rear portion 134 mounted by linear bearings 136 on the columns 116. To raise and lower the platform 130, an offset arm 138 extends from an outermost linear bearing 136 through a slot 139 in the wall 108 to engage a lead screw 140 which is separately driven by a motor 141 supported on a bracket 143 from the wall 108. Upper locators 142 a, 142b, 142c are supported from the block 106 by sets of slide rods 144a, 144b, 144c respectively. A spigot 148 supported by a stand 149 and rotatable by a motor 146 supports the wall 108 so as to be capable of inverting the all 108.
In use of the dispenser, (e.g. for obtaining a dose of Technetium 99 m) 10, syringes 48, vial shields 54, needles 49, sheaths 50, hubs 53, vials 62, etc. may be stored in the trays 36. The robot device 14 presents an inverted vial shield 54 containing a vial 62 to a selected radioisotope generator 26 or 28. The vial shield 54 is pressed downwards so that the needle of the socket connector 42 or 44 penetrates the hole 69 and the rubber plug 70 of the vial 62. The vial 62 is usually under vacuum so that liquid containing a radionuclide is sucked from the respective generator 26, 28 into the vial 62. The vial shield 54 is then placed by the jaws 20a, 20b in the hole 39 to locate the pins 74a, and the cap 58 is removed. The vial 62 is extracted and placed on the lower platform 79 and lowered by the monitor assembly 30 to the radioactivity detector. The vial 62 is then placed in the vial shield 54a located in one of the holes 38, and the vial shield 54a placed on the lower platform 79 for monitoring by the radioactivity detector. Subsequently the vial 62 is extracted from the vial shield 54a, returned to the original vial shield 54 and placed on the platform 130 (FIGS. 9 and 10). A syringe (e.g. 94a) of the appropriate capacity is fitted into the assembly 32, and the platform 130 is raised so that the needle of the syringe 94a pierces the vial 62 in the vial shield 54. The wall 108 is inverted by the motor 146, and the syringe plunger 95a is lifted and lowered several times by the tangs 100a, 100b so as to withdraw liquid from the vial 62 and expel liquid and air into the vial 62. Finally the plunger 95a is lifted to withdraw liquid from the vial 62 into the syringe 94a. The wall 108 is inverted again, the platform 130 is lowered, and the vial shield 54 removed and placed in one of the trays 36. The syringe 94a, may be removed from the assembly 32, and placed by the robot device 14 into the intermediate support 82 of the monitor assembly 30 so that the radioactivity of the syringe 94a, 94b or 94c may be checked by the detector. A measured dose may be injected into a vial 62 by placing it on the platform 130, raising the platform 130, and lowering the plate 112 so as to depress the plunger 95a, and inject the dose from the syringe 94a into the vial 62.
The wall 108 may be inverted several times to agitate the vial 62. It will be understood that a similar procedure will be followed for a syringe 94b, 94c.
Appropriate fittings (not shown) may be attached to the trays 36 to hold the vial shields 54, or sheaths and enable the robot device 14 to remove and replace the cap 58, etc. Shielded receptacles (not shown) may be located in the trays 36 to locate the loaded syringes 94a, 94b, 94c, vials 62, etc.
Preferred linear bearings are those made by THK Co Ltd, Tokyo 141, Japan, and obtainable inter alia from:
______________________________________(1) Unimatic Engineering Ltd 122 Granville Road London NW2 2LN United Kingdom(2) THK America Inc 1300 Landmeier Road Elk Grove Village Illinois 60007 United States of America______________________________________
It will be understood that if desired the assembly 32 may be modified to accept two, or more than three syringes, and may be operated in an alternative manner from that described above.
lf dose dilution is required, saline solution may be withdrawn from an appropriate vial 62 by use of the syringe 48, and then inserted into a required vial 62.
Non-nuclear pharmaceutical doses may be dispensed by the dispenser 10, for example doses containing cytotoxins. The radiopharmaceutical uses of the dispenser 10 may relate to diagnostic and radiotherapeutic applications.
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A dispensing apparatus comprises a base, and a robot device on the base having opposing jaw members. A number of stations locate on the base, and cooperate with the robot device in a sequence of operations such as to produce a measured pharmaceutical dose from a supply of a pharmaceutically acceptable substance. One of the stations locates several hypodermic syringes in parallel and a container, and produces relative movement of the appropriate syringe and the container towards and away from each other to arrange that the syringe penetrates and withdraws from the container.
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BACKGROUND OF THE INVENTION
This invention relates generally to alloys, and more particularly to alloys formed on the surface of stainless steel.
Electrochemical conversion cells, commonly referred to as fuel cells, produce electrical energy by processing reactants, for example, through the oxidation and reduction of hydrogen and oxygen. A typical polymer electrolyte fuel cell comprises a polymer membrane (e.g., a proton exchange membrane (PEM)) with electrode layers (e.g., containing at a minimum one catalyst type and one ionomer type) on both sides. The catalyst coated PEM is positioned between a pair of gas diffusion media layers, and a cathode plate and an anode plate are placed outside the gas diffusion media layers. The components are compressed to form the fuel cell.
FIG. 1 shows one embodiment of a fuel cell 10 . The fuel cell includes a PEM 15 between a pair of electrodes 20 . The electrodes 20 form a cathode and an anode for the fuel cell. The electrodes 20 may be deposited onto the PEM 15 , as in the CCM design, to form an MEA 25 . There is a gas diffusion media (GDM) 30 adjacent to each of the electrodes 20 . Alternatively, the electrodes 20 can be deposited onto the GDM, as in the CCDM design. Adjacent to each of the GDM is a fuel cell plate 35 . These fuel cell plates can be unipolar or bipolar plates, as known in the art.
The anode and cathode plates are typically made of stainless steel. The surface composition of stainless steel is known to affect its properties. For example, iron contributes significantly to the composition of the passive oxide films on entry grade stainless steels and other highly alloyed stainless. In addition, the presence of iron in the passive films of nickel/chromium alloys increases contact resistance with carbon-type papers (such as are used as GDM). Chromium contributes to the corrosion resistance of stainless steel. Chromium is also a well known adhesion promoter, and it can contribute significantly to the adhesion of gaskets on stainless steels.
As a result, the surface of the stainless steel fuel cell plates has been coated to obtain the desired properties, such as corrosion resistance and adhesion. For example, plating techniques and physical vapor deposition (PVD) have been used to coat stainless steel with alloys with high chromium and/or titanium content or layers of chromium and/or titanium in order to improve the corrosion resistance, or adhesion, for example. However, these plating and PVD coating methods are expensive. Moreover, there can be adhesion problems between the additional layers.
SUMMARY OF THE INVENTION
One aspect of the invention is a method of surface alloying stainless steel. In one embodiment, the method includes providing a stainless steel surface having an initial amount of iron and an initial amount of chromium; and preferentially removing iron from the stainless steel surface to obtain a surface having an amount of iron less than the initial amount of iron and an amount of chromium greater than the initial amount of chromium.
Another aspect of the invention is a unitary stainless steel article. In one embodiment, the article has a surface amount of iron less than a bulk amount of iron and a surface amount of chromium greater than a bulk amount of chromium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a fuel cell.
FIG. 2 is an illustration of the active region of the polarization curve.
FIGS. 3A-C illustrate the effect of various treatments according to the present invention on the stainless steel surface layer.
DETAILED DESCRIPTION OF THE INVENTION
The invention allows the production of surface alloys on different types of stainless steel without the necessity of using expensive coating techniques.
Iron is removed from the surface of the stainless steel alloy using thermal and/or chemical methods, producing a surface enriched with chromium and nickel, as well as other metals, such as vanadium or titanium, if they were originally in the stainless steel. The ratio of iron to chromium at the surface can be at least about 1:1.5, or at least about 1:2, or at least about 1:2.5, or at least about 1:3, or at least about 1:3.5, or at least about 1:4. The surface enrichment can be measured using X-Ray photoelectron spectroscopy (XPS) surface analysis. This process allows the use of a lower grade stainless steel alloy for an application, but with the improved surface properties of a higher grade alloy.
The enriched layer can be up to about 1 micron thick, typically about 1 nm to about 750 nm, or about 1 nm to about 500 nm, or about 1 nm to about 250 nm, or about 1 nm to about 100 nm.
The surface enrichment can be achieved in several ways. In one method, the potential of the stainless steel is held in the active region 1 of the polarization curve, as illustrated in FIG. 2 . Under these conditions, the passive film no longer protects the surface, and the iron dissolves as ferrous ions. The soluble ferrous ions are then removed electrochemically or by plasma etching, leaving behind a layer which is rich in chromium, see Table 1. Table 1 shows the XPS Semi quantitative Elemental Surface Composition, Atomic %, Except H, for alloy 446 stainless steel before and after treatment.
TABLE 1
coupon
C
O
Fe
Cr
Si
N
Ca
Cl
S
P
before
40
44
6
5
1.1
1.2
0.5
1.2
0.5
0.6
after
45
38
2
10
—
1.5
—
1.1
1.7
—
Alternatively, the stainless steel can be made active by immersing in hydrochloric acid at room temperature. This allows for the preferential removal of iron from the surface the stainless steel. An example would be to use a 1-10% hydrochloric acid solution and treat the stainless steel at room temperature in this solution for about 1-30 seconds. Longer times would lead to severe etching of the stainless steel, degrading its mechanical properties, particularly when using thin foils (e.g., about 75 to about 100 micrometer) to make the bipolar plate.
Samples of 304L stainless steel were immersed in 10 wt % HCl for about 10 sec at room temperature. The samples were then washed with deionized water, and the surface was examined using XPS analysis. The semi-quantitative surface scan showed that before the HCl treatment, the iron/chromium ratio was about 1:1, while after the treatment it was about 1:4. This indicates significant enrichment of the passive film with chromium as a result of the preferential removal of iron from the passive film. The concentration of HCl was varied from 1-20%. A concentration of 10% and a time of 10 sec was suitable to avoid significant etching of the stainless steel during treatment.
In yet another embodiment, the stainless steel is treated with a concentrated solution of sulfuric acid to activate the surface of the stainless steel and remove iron preferentially from the surface. For this treatment a concentrated solution of 1-30% sulfuric acid is used to activated the surface and to remove iron preferentially. Higher concentrations of sulfuric acid (about 10-30%) can be used at room temperature to accelerate the activation process, while lower concentrations (about 1-10%) can be used at relatively higher temperature 50-80° C. for shorter periods of time (about 1-10 seconds). Hydrogen gas evolution of the surface is a sign that the stainless steel is in the active region and iron is being removed. The removal of iron from the stainless steel was accompanied by reduction in contact resistance, see Table 3. Table 3 shows the total resistance obtained on different entry grades stainless steel substrates before and after room temperature etching in 8M sulfuric acid solution at room temperature.
TABLE 3
Total resistance mohm cm2,
paper/paper@200 psi
Sample
Before etching
After etching
304L SS
300
16
439 SS“ferritic”
250
17
446
170
16.5
436L “AK”
240
17
409L SS“AK”
260
15.5-17
Another method involves heat treating the stainless steel in air at temperatures greater than about 250° C. The iron diffuses to the surface where it is oxidized preferentially. This takes place in an oxygen-containing environment, such as in air. The surface is then etched chemically (for example, with hydrochloric acid, sulfuric acid, or oxalic acid and hydrogen peroxide) or electrochemically to remove the iron oxide layer to expose the surface underneath which will be rich in chromium and nickel.
FIGS. 3A-C illustrate the effect of various treatments on the surface composition of the stainless steel. FIG. 3A illustrates the initial surface composition of a stainless steel alloy. FIG. 3B illustrates the surface composition after heat treatment, showing the decrease in iron at the surface and the increase of chromium oxide and vanadium oxide. FIG. 3C illustrates the surface composition after removing the vanadium oxide layer by using, for example, ion sputtering, leaving a layer of chromium oxide that is almost 2 microns thick. The chromium rich layer acts as an adhesion promoter for polymeric gaskets and carbon coatings. In most cases, both polymeric gaskets and carbon coatings require tie layers of chromium or titanium to improve adhesion to the stainless steel surface. The tie layer adds another layer to the coating, while in the present invention, the chromium rich layer is part of the stainless steel surface that should provide excellent self adhesion to polymeric gasketing materials.
A third method involved electropolishing the stainless steel/alloy surface to remove iron, which is less stable than chromium, leaving a surface with enriched with chromium.
With respect to any of the methods, if the surface does not have the desired contact resistance after the surface enriching treatment, it can be thermally nitrided or plasma nitrided to obtain lower contact resistance, if desired.
A fuel cell plate made according to the present invention can be used with any appropriate fuel cell components.
The surface treatment of stainless steel can provide one or more advantages depending on the application involved. It can improve the corrosion resistance of the stainless steel alloy without the use of expensive coatings. It can improve the adhesion of polymeric materials, such as gaskets, to stainless steel surfaces. It can also improve the adhesion of metallic and non-metallic coatings, such as gold, carbon, and the like, to stainless steel surfaces without the necessity of applying an adhesion layer. Improved adhesion is important for use in PEM fuel cells and other applications where chromium or titanium layers are currently required to promote adhesion. In some alloy systems, surface treatment can significantly improve contact resistance on the alloy surface with the gas diffusion layer.
Further, it is noted that recitations herein of a component of an embodiment being “configured” in a particular way or to embody a particular property, or function in a particular manner, are structural recitations as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural factors of the component.
It is noted that terms like “generally,” “commonly,” and “typically,” when utilized herein, are not utilized to limit the scope of the claimed embodiments or to imply that certain features are critical, essential, or even important to the structure or function of the claimed embodiments. Rather, these terms are merely intended to identify particular aspects of an embodiment or to emphasize alternative or additional features that may or may not be utilized in a particular embodiment.
For the purposes of describing and defining embodiments herein it is noted that the terms “substantially,” “significantly,” and “approximately” are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms “substantially,” “significantly,” and “approximately” are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Having described embodiments of the present invention in detail, and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the embodiments defined in the appended claims. More specifically, although some aspects of embodiments of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the embodiments of the present invention are not necessarily limited to these preferred aspects.
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One aspect of the invention is a method of surface alloying stainless steel, In one embodiment, the method includes providing a stainless steel surface having an initial amount of iron and an initial amount of chromium; and preferentially removing iron from the stainless steel surface to obtain a surface having an amount of iron less than the initial amount of iron and an amount of chromium greater than the initial amount of chromium. Another aspect of the invention is a unitary stainless steel article.
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BACKGROUND OF THE INVENTION
[0001] The increasing reliance upon computer systems to collect, process, and analyze data has led to the continuous improvement of the system assembly process and associated hardware. With the improvements in speed and density of integrated circuits, the cost and complexities of designing and testing these integrated circuits has dramatically increased. Currently, large complex industrial integrated circuit testers (commonly referred to in the industry as “Automated Test Equipment” or “ATE”) perform complex testing of integrated circuit devices, such as integrated circuits, printed circuit boards (PCBs), multi-chip modules (MCMs), System-on-Chip (SOC) devices, printed circuit assemblies (PCAs), etc. The tests that must be performed may include, among others, in-circuit test (ICT), functional test, and structural test, and are designed to verify proper structural, operational, and functional performance of the device under test (DUT).
[0002] An example of an automated test is the performance of an in-circuit test. In-circuit testing, which verifies the proper electrical connections of the components on the printed circuit board (PCB), is typically performed using a bed-of-nails fixture or robotic flying-prober (a set of probes that may be programmably moved). The bed-of-nails fixture/robotic flying-prober probes nodes of the device under test, applies a set of stimuli, and receives measurement responses. An analyzer processes the measurement responses to determine whether the test passed or failed.
[0003] A typical in-circuit test will cover many thousands of devices, including resistors, capacitors, diodes, transistors, inductors, etc. Tests are typically passed to the tester via some type of user interface. Typically, the user interface allows a technician to enter various configurations and parameters for each type of device to automatically generate tests for devices of that type. However, for various reasons, it is often the case that a fairly significant percentage (e.g., 20%) of the automatically generated tests are faulty in that when executed on a known good device under test, the test is unable to determine the status of the device or component under test. Clearly, for devices under test that include thousands of components, this results in a large number of tests that must be manually repaired. Expert technicians typically know how to repair a faulty test. However, with such a large number of faulty tests to repair, a large (and therefore, very costly) amount of time may be spent in test debug and optimization rather than in actual testing of the device itself. The time spent in debug is also dependent on the amount of knowledge and experience of the test engineer.
[0004] It would therefore be desirable to capture the knowledge of experienced test engineers and formulate it into a format that s reusable by automated test systems. More generally, it would be desirable to develop a method and framework for binding complex actions into rules and rule sets associated with devices under test.
SUMMARY OF THE INVENTION
[0005] The present invention is a method and apparatus for binding knowledge and experience into a reusable rule format and storage framework that can be used by a test formulating engine in creating viable tests. In accordance with the invention, a method and system for configuring an automated test associated with a component to be tested on a tester is provided in which one or more validation criteria are associated with one or more actions to be performed to generate first associations, the one or more actions are associated with one or more rules to generate second associations, and one or more of the one or more rules are associated with the component to be tested on the tester to generate third associations. The first associations, the second associations, and the third associations are maintained in a knowledge framework to be reused for configuration of various tests. In a preferred embodiment, one or more rules are associated with a rule set, which is associated with the component to be tested, and the one or more rules associated with the rule set preferably each have an associated priority level indicating an order that the respective rule should be processed with respect to others of the one or more rules associated with the rule set.
[0006] Each of the above techniques may be implemented in hardware, software stored on a computer readable storage medium tangibly embodying program instructions implementing the technique, or a combination of both.
[0007] Preferably, the first, second, and third associations are extracted from a user by way of a user input graphical user interface in conjunction with a knowledge framework interface that stores the associations in a knowledge framework (i.e., in storage memory).
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more complete appreciation of this invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
[0009] FIG. 1 is a block diagram of a rule-based system in accordance with the invention;
[0010] FIG. 2 is block diagram of an action framework;
[0011] FIG. 3 is a relationship diagram illustrating the relationship between a rule set, rules, and actions;
[0012] FIG. 4 is a relationship diagram illustrating the relationship between the action framework and the user input interface;
[0013] FIG. 5 is a flowchart illustrating operation of the test formulation engine of the rule-based system of FIG. 1 ;
[0014] FIG. 6 is a schematic block diagram of FIG. 6 a rule with a number of associated actions;
[0015] FIG. 7A is a schematic block diagram of an automated test system implemented in accordance with the invention;
[0016] FIG. 7B is a schematic diagram of a measurement circuit;
[0017] FIG. 8 is a block diagram of an automated test debug and optimization system in accordance with the invention;
[0018] FIG. 9 is a block diagram of a knowledge framework in accordance with the invention;
[0019] FIG. 10 is a structural diagram of a rule;
[0020] FIG. 11A is a block diagram of a preferred embodiment of a test formulation engine;
[0021] FIG. 11B is a flowchart of a preferred method performed by the test formulation engine of FIG. 11A ;
[0022] FIG. 12 is a block diagram of an example knowledge framework in accordance with the invention; and
[0023] FIG. 13 is an example graphical user interface screen of a preferred embodiment user input GUI of FIG. 8 .
DETAILED DESCRIPTION
[0024] Turning now to the invention, FIG. 1 shows a rule based system 1 which utilizes the invention. As illustrated, the rule based system 1 includes three main components, namely a rule-based system controller 2 , a knowledge framework 5 , and a knowledge framework interface 6 /user input graphical user interface (GUI) 7 . The rule-based system controller 2 controls the interaction between a tester 8 and the rule-based system 1 . The knowledge framework 5 contains the test knowledge, including rule framework 5 a and rule design 5 b . The knowledge framework interface 6 and user input GUI 7 are together used to capture user knowledge into assns of rule sets, rules, and actions.
[0025] FIG. 2 illustrates a preferred embodiment of the action framework. As illustrated, there are three main categories of actions, namely one-time, iterative and condition. The “one-time” class is a one-off test that is independent of the testing environment and it is similar to a normal manual test.
[0026] Within the iterative class, there are two sub-categories, namely test result independent and test result dependent. The condition class comprises two sub-categories, namely test dependent and result dependent.
[0027] In the preferred embodiment, a user input graphical user interface is used to configure and maintain the relationships between rule sets, rules and actions. FIG. 3 is a relationship diagram illustrating the relationship between a rule set 10 , rules 11 , and actions 12 . In particular, each rule set 10 may be associated with (i.e., mapped to) zero or more rules 11 , and each of those rules 11 may be associated with zero or more actions 12 .
[0028] The relationship between the action framework and the user input accepted during rule creation by the graphical user interface 7 and knowledge framework interface 6 is shown in FIG. 4 . Table 1 gives a brief overview of the types of input expected during rule creation and how it is related and contained within the action framework. Examples are given in the context of an automated debug process for an in-circuit test system.
TABLE 1 Name Description Action An action is a step that is described in computer representation. In the illustrative embodiment, this step is undertaken to debug/optimize an in-circuit test system. An Action may or may not come with a specific instruction/algorithm. One-time A one-off test that is independent of the testing environment and is similar to a normal manual test Iterative The same action can be applied in an iterative manner. There are two categories in this class, including test result dependent and result dependent. Condition This action will be activated based on a certain criteria. The two categories in this class are test dependent and result dependent. Range & Step Action can accept the setting of hi-lo ranges and the step or increment of the search for an optimal value Range & Step Action can accept the setting of hi-lo ranges and the with step or increment of the search for an optimal value. execution The application of these parameters is deemed criteria possible if it satisfies the criteria set by the user (eg CPK). Normally, a test will be executed to measure the effectiveness of this new setting. Apply offset Action can accept the setting of hi-lo ranges and with the step or increment of the search for an optimal value. execution The accepted parameters will be applied if the criteria previous test result satisfies the execution criteria. Normally, a test will not be executed to measure the effectiveness of this new setting. Choices Action can accept the selection of options to be (Checkboxes) included for the test.
[0029] The action framework represents the test strategy. The test strategy gives a flavor of how a test will be formulated and executed. For Condition Test Strategy, it means assessing the criteria for execution with the result of the previous test. It also determines whether if a specific set of instructions is applicable to this particular test or not. The Iterative Strategy checks for pre-test condition before formulating the test statement and gives specific instruction for some tests. The strategy also plans the combination of the test.
[0030] FIG. 5 illustrates the example operation of the test formulation engine 3 in the rule-based system 2 of FIG. 1 .
[0031] Turning now to an example of how the test formulation engine formulates a test, FIG. 6 illustrates schematically a rule with seven actions, namely A, B, C, D, E, F and G. The actions are categorized by type, as shown. A number (indicated by “−<#>” following the name of each action indicates the number of combinations to complete the entire test for this action.
[0032] In operation, the test formulation engine performs the following sequence:
[0033] (1) One-Time—Set F 1 and G 1 as the fundamental of the test statement
[0034] (2) Condition—Set C 1 , C 2 , D 1 as result assessment and E 1 as result assessment without test
[0035] (3) Iterative—Set A 1 , A 2 and B 1 , B 2 , B 3 as iterative
[0036] Table 2 illustrates the general execution of the test from the example of FIG. 6 .
TABLE 2 Step One-Time Iterative Test Statement 1 F1G1 A1B1 F1G1A1B1 = X 2 Condition Checking 1 Condition If C is applicable X<CD> A parameter then C1 enclosed by “<” If C is applicable & and “>” means C1 then C2 the parameter If D is applicable may or may not then D1 be there Condition Checking 2 If C & D are not X<CD>E1 applicable & (end of E then E1 autodebug) 3 F1G1 A1B2 F1G1A1B2 = X 4 Refer to Condition with the new X statement 5 F1G1 A1B3 F1G1A1B3 = X 6 Refer to Condition with the new X statement 7 F1G1 A2B1 F1G1A2B1 = X 8 Refer to Condition with the new X statement 9 F1G1 A2B2 F1G1A2B2 = X 10 Refer to Condition with the new X statement 11 F1G1 A2B3 F1G1A2B3 = X 12 Refer to Condition with the new X statement
[0037] The invention will now be discussed in the context of an automated debug and optimization system for an automated in-circuit test system. FIG. 7A is a schematic block diagram of an automated test system 2 . As illustrated, the test system includes a test head 101 which supports a fixture 53 on which a printed circuit board (PCB) containing or implementing a device under test (DUT) 51 is mounted, and an automated test debug and optimization system 100 . The test head 101 includes a controller 60 , a test configuration circuit 50 , and a measurement circuit 62 . Fixture 53 , for example a bed-of-nails fixture, is customized for each PCB layout and includes a plurality of probes 52 that electrically connect to nodes of the device under test 51 when the device under test 51 is properly seated on the fixture 53 . Probes 52 are coupled via the fixture 53 to interface pins 54 .
[0038] The test configuration circuit 50 includes a matrix 56 of relays 55 which is programmable via controller 60 over control bus 61 to open and/or close each relay 55 in the matrix 56 to achieve any desired connection between the interface pins 54 of the test head 101 and a set of measurement busses 63 internal to the test head 101 . Measurement busses 63 are electrically connected to nodes of the measurement circuit 62 . The particular nodes of measurement circuit 62 which are connected to the set of measurement busses 63 may be hardwired within the measurement circuit 62 , or alternatively, may be configurable via another programmable matrix (not shown) of relays. Controller 60 receives test setup instructions from the automated test debug and optimization system 10 to program the matrix 56 (and other relay matrices, if they exist) to achieve a set of desired connection paths between the device under test 51 and measurement circuit 62 . Automated test debug and optimization system 10 , discussed in detail hereinafter, debugs and/or optimizes in-circuit tests to be performed on the device under test 51 .
[0039] FIG. 7B illustrates an example instance 70 of a measurement circuit 62 . Measurement circuit 70 is known as a “two-wire” measurement circuit. Measurement circuit 70 includes operational amplifier 72 having a positive input terminal 86 coupled to ground and a negative input terminal 88 coupled to an input node I 80 . A reference resistor R ref 82 is coupled between output node V O 84 and input node I 80 of operational amplifier 72 . A component under test 78 on the DUT 51 characterized by an unknown impedance Z x is coupled between input node I 80 and a source input node S 76 . The source input node S 76 is stimulated by a known reference voltage V S that is delivered by a voltage stimulus source 74 . Assuming an ideal operational amplifier circuit, the current through the unknown impedance Z x of the component under test 78 should be equal to the current through reference resistor R ref 82 and a virtual ground should be maintained at negative input terminal 88 . As is well-known in the art, in an ideal operational amplifier circuit the theoretical impedance calculation is:
Z x =−R ref ( V S /V O )
[0040] The use of a precision DC voltage stimulus source 74 and a DC detector at output node V O 84 is employed to determine the resistive component of the output voltage when testing resistive analog components such as resistors. The use of a precision AC voltage stimulus source 74 and a phase synchronous detector at output node V O 84 is employed to determine the reactive components of the output voltage when testing reactive analog components such as capacitors and inductors.
[0041] Additional measurements, outside the scope of the present invention, are often taken to reduce guard errors and compensate for lead impedances. In order to take a set of measurements, the connection paths from the component under test 78 on the DUT 51 to the measurement circuit 62 are set up by programming the relay matrix 56 to configure the relays 55 to electrically connect the probes 52 of the bed-of-nails fixture 53 that are electrically connected to the nodes on the device under test 51 to the measurement circuit 62 via the internal measurement busses 20 . In the example measurement circuit 70 of FIG. 7B , the internal measurement busses include an S bus and an I bus which are respectively electrically connected to the S node 76 and I node 80 . Connections of the internal measurement busses 20 from the device under test 51 to the measurement circuit 62 are programmed at the beginning of the test for the component under test 78 , during the test setup. After the connections have been made, the actual test measurements of the component under test 78 may be obtained by the measurement circuit 62 after waiting for the inherent delays of the relay connections to be completed. At the conclusion of the test, the relay connections are all initialized to a known state in preparation for the start of the next test.
[0042] The measurement circuit 70 described in FIG. 7B is for purposes of example only. FIG. 7B illustrates example hardware connections, in particular, the measurement circuit 62 of FIG. 7A , that must be provided by in-circuit ATE to perform the in-circuit test on a particular device, in this case as device characterized by an unknown impedance Z X . It will be appreciated, however, that a typical in-circuit test will cover many thousands of devices, including resistors, capacitors, diodes, transistors, inductors, etc.
[0043] An exemplary embodiment 100 of the automated test debug and optimization system 10 of FIG. 7A is shown in more detail in FIG. 8 . As illustrated in FIG. 8 , the automated test debug and optimization system 100 preferably includes a test head supervisor 104 , an autodebug controller 106 , a knowledge framework 120 , a dispatch queue 112 , and a result property listener 114 .
[0044] The test head supervisor 104 receives a test 102 for debug/optimization. The test 102 may be received from an interactive graphical user interface test setup program or from a test file input means. Below is an example of source file R208. dat for a resistor device family.
R208.dat !!!! 2 0 1 1021582599 0000 ! IPG: rev 05.00pd Thu May 16 14:56:40 2002 ! Common Lead Resistance 500m, Common Lead Inductance 1.00u ! Fixture: EXPRESS disconnect all connect s to “R208-1”; a to “R208-1” connect i to “R208-2”; b to “R208-2” resistor 10, 12.8, 3.75, re1, ar100m, sa, sb, en ! r208” is a limited test. ! DUT: nominal 10, plus tol 1.00%, minus tol 1.00% ! DUT: high 10.1, low 9.9 ! TEST: high limit 11.276, low limit 9.625 ! Tolerance Multiplier 5.00 ! Remote Sensing is Allowed
[0045] The test 102 received by the tester will typically be packaged in a data structure that includes the information contained in the source file of the test to be debugged, and also other information such as device name, etc.
[0046] Typically the test 102 will be a flawed in-circuit test to be debugged/optimized such as a test that fails the component or is unable to determine status of one or more parameters of the test when tested on a known good board (i.e., when it is known that the component is good and the test should pass the component). Each test 102 tests a single individual component on the DUT 51 mounted on the tester, and is a representation of the test source file that has been prepared (i.e. compiled into object code and therefore no longer in the ASCII text readable format) to run/execute on a different processor on the test head 101 .
[0047] The test head supervisor 104 acts as the interface between the test head 101 and automated test debug and optimization system 100 whose purpose is to protect the test head resource from overloading. In the preferred embodiment, the test head 101 itself is a single processing resource; accordingly, the test head 101 can execute only a single job in any given time slot. The test head supervisor 104 operates to protect the test head by monitoring the allocation of the test head 101 resource. In the preferred embodiment, the test head supervisor 104 is implemented as a Java thread, which processes various jobs that are to be sent to the test head 101 . When the test head supervisor 104 receives a test 102 to be debugged/optimized, it activates an autodebug controller 106 . The method of activation depends on the particular implementation of the automated test debug and optimization system 100 . For example, the autodebug controller 106 may be implemented as a static procedural function that receives the test 102 (or a pointer to the test 102 ) as a parameter. In yet another embodiment the autodebug controller 106 is implemented as hardware with a separate processor and memory for storing program instructions for implementing the functionality of the autodebug controller 106 . In the preferred embodiment, the test head supervisor 104 instantiates an autodebug controller 106 object, passing it the received test 102 , whose lifetime begins when instantiated by the test head supervisor 104 for debug/optimization and ends upon completion of the debug/optimization process for the received test 102 .
[0048] The autodebug controller 106 includes a test formulation engine 108 which generates one or more proposed theoretically unflawed tests 109 that are ready for execution by the test head 101 during the lifetime of the autodebug controller 106 . In generating the proposed theoretically unflawed test 109 , the test formulation engine 108 accesses the knowledge framework 120 to determine the appropriate actions to take, the validation criteria, and stability criteria.
[0049] The knowledge framework 120 contains the test knowledge about the various components to be tested on the DUT 51 , which allows the autodebug controller 106 to determine how to formulate and package a given test. A more detailed diagram of a preferred embodiment of the knowledge framework 120 is illustrated in FIG. 9 . As shown therein, the knowledge framework 120 includes one or more rule sets 122 a , 122 b , . . . , 122 m . Each rule set 122 a , 122 b , . . . , 122 m , has associated with it one or more rules 124 a — 1 , 124 a — 2 , . . . , 124 a — i , 124 b — 1 , 124 b — 2 , . . . , 124 b — j , 124 m — 1 , 124 m — 2 , . . . , 124 m — k . FIG. 10 illustrates the structure 124 of each rule 124 a — 1 , 124 a 2 , . . . , 124 a — i , 124 b — 1 , 124 b — 2 , . . . , 124 b — j , 124 m — 1 , 124 m — 2 , . . . , 124 m — k . As shown in FIG. 10 , each rule preferably includes three components, including an action component 130 , a validation test component 132 , and a stability test component 134 (e.g., a process capability index (CPK)).
[0050] The action component 130 represents the debugging/optimization strategy. The action component 130 can implement or point to code such as library functions that are to be executed.
[0051] The validation test component 132 comprises or points to a test or algorithm that compares an expected result against the actual results measured by the tester. Typically the validation test component 132 will include many expected parameter values to be verified against the received parameter values in order to verify that the proposed theoretically unflawed test 109 passed.
[0052] The stability test component 134 is conducted to verify the robustness of a test. During operation, the stability test component 134 is only performed if the validation test passes. Stability test is conducted by applying the validity test a number of times to gather its statistical value (e.g., the process capability index CPK). The CPK is a measurement that indicates the level of stability of the formulated test derived from the knowledge framework 120 .
[0053] The knowledge framework 120 includes a rule set for every possible component (e.g., resistor, car, diode, FET, inductor, etc.) to be tested on the DUT 51 . The autodebug controller 106 operates at an active rule-set level. Each device/component family can have many rule sets, but at any given time, only one rule set in the knowledge framework 120 can be active. The test formulation engine 108 in the autodebug controller 106 executes only the rules in the active rule set for each device/component family.
[0054] The set of rules 124 in each rule set 122 are ordered according to a predetermined priority order. The test formulation engine 108 executes the rules within the rule set according to the predetermined priority order. In particular, the test formulation engine 108 generates a list of parameters/measurements that the test head should obtain based on the action component 130 and validation component 132 of the currently selected rule 124 of the active rule set 122 . This list of parameters/measurements represents the merits of the test from which the component being tested can be classified as “good” or “bad”. Other classifications are possible.
[0055] Once the test formulation engine 108 generates a proposed theoretically unflawed test 109 , the proposed theoretically unflawed tests 109 is sent to a dispatch queue 112 . The dispatch queue 112 stores testhead-ready tests in priority order (e.g., first-in first-out) in a queue. As the test head resource comes available, the test head supervisor 104 removes a test from the queue, and dispatches it to the test head 101 for execution.
[0056] The result property listeners 114 monitor status and data coming back from the test head 101 and packages the status and data into autodebug results 115 . The autodebug results 115 comprise the test parameters that are actually measured by the test head during execution of the test. The autodebug results 115 are passed back to the test head supervisor 104 , indicating that test execution on the test head 101 is complete and that the test head 101 resource is freed up for a new job. The test head supervisor 104 forwards the autodebug results 115 on to the autodebug controller 106 , and if there are additional jobs waiting for dispatch to the test head 101 present in the dispatch queue 112 , removes the next job from the queue 112 and allocates the test head 101 resource to execution of the next job.
[0057] The autodebug controller 106 includes a test results analyzer 110 . The test results analyzer 110 processes the autodebug results 115 from the tester, comparing the actual parameters/measurements to those expected as indicated in the test validation component 132 of the rule 124 from which the proposed theoretically unflawed test 109 was generated.
[0058] If one or more of the actual test parameters does not meet the expected parameters/measurements set forth by the test validation component 132 of the rule 124 from which the proposed theoretically unflawed test 109 was generated, the test is considered bad and is discarded. If additional unprocessed rules 124 in the active rule set 122 remain to be processed, the test formulation engine 108 then selects the next highest priority rule 124 from the set 122 , and generates a new proposed theoretically unflawed test 109 based on the selected new rule.
[0059] The process is repeated until a valid proposed theoretically unflawed test 109 is found. Once a valid proposed theoretically unflawed test 109 is found, then the test is re-executed one or more iterations to generate actual stability levels (e.g., CPK) and compared to the required stability criteria as set forth in the stability component 132 of the rule 124 from which the current proposed theoretically unflawed test 109 was generated. If the current proposed theoretically unflawed test 109 passes the stability test, it is considered a valid test.
[0060] The following sequence details how the test results analyzer 110 proceeds based on received test results 115 .
[0000] 1. Valid Test
[0061] a. If Pass then check Stability Test
i. If On then Proceed to run this test N times for stability testing (put this entry into queue as multiple test ID) ii. If Off then Inform Testhead Supervisor of the status
[0064] b. If Fail then Continue to search for valid test
[0000] 2. Stability Test
[0065] a. If Pass then Inform Testhead Supervisor of the status
[0066] b. If Fail then Continue to search for valid test
[0067] If the automated test debug and optimization system 100 is configured to perform debug only, once a valid proposed theoretically unflawed test 109 is found, the valid proposed theoretically unflawed test 109 is preferably used in place of the test 102 presented for debug, and processing of the test 102 is complete.
[0068] If the automated test debug and optimization system 100 is configured to perform optimization also, the test formulation engine 108 will formulate all possible valid proposed theoretically unflawed tests 109 (that meet validity and stability tests) and will then select the particular valid proposed theoretically unflawed test 109 that best meets the validity and stability criteria. This selected “best” test is then used in place of the test 102 presented for debug, and processing of the test 102 is complete.
[0069] FIG. 11A is a block diagram of, and FIG. 11B is a flowchart illustrating the general operation of, the autodebug controller 106 of FIG. 11A . As illustrated in FIGS. 6A and 6B , the autodebug controller 106 receives a test 102 to be debugged and/or optimized (step 201 ). The test formulation engine 108 accesses the knowledge framework 120 to determine the actions, validation criteria, and stability criteria appropriate to the component being tested by the test 102 (step 202 ). As discussed previously, in the preferred embodiment, the knowledge framework 120 includes one or more rule sets, each with one or more rules having associated actions, validation criteria, and stability criteria. In this preferred embodiment, the autodebug controller 106 activates the rule set corresponding to the component being tested by the test 102 . The autodebug controller 106 then determines whether there are more possible actions to try in formulating a valid test, as determined from the knowledge framework 120 (step 203 ). If more actions exist to try in formulating a valid test, the autodebug controller 106 selects the next action and its associated validation and stability criteria (step 204 ). The autodebug controller 106 then formulates a proposed theoretically unflawed test 109 based on the selected action and its associated validation and stability criteria (step 205 ). The proposed theoretically unflawed test 109 is then submitted to the test head 101 for execution (step 206 ).
[0070] The autodebug controller 106 awaits results of the proposed theoretically unflawed test 109 from the test head 101 (step 207 ). When the results are returned from the test head 101 , the autodebug controller 106 then analyzes the returned test results to determine whether the proposed theoretically unflawed test 109 is valid based on the validation criteria. As also discussed previously, generally the validation criteria consists of a series of expected parameter measurements. Accordingly, in this embodiment, the autodebug controller 106 compares the actual parameter measurements as received in the test results to the expected parameter measurements. If the actual parameter measurements meet the validation criteria (i.e., match the expected parameter measurements), the proposed theoretically unflawed test 109 is considered valid; otherwise invalid. If the proposed theoretically unflawed test 109 is not valid (determined in step 209 ), the autodebug controller 106 returns to step 203 to determine whether more actions are available to try.
[0071] If the proposed theoretically unflawed test 109 is valid (determined in step 209 ), the autodebug controller 106 determines whether or not the proposed theoretically unflawed test 109 should be rerun to collect stability measurements for the stability test (step 210 ). If so, the autodebug controller 106 returns to step 206 to resubmit the proposed theoretically unflawed test 109 to the test head for execution.
[0072] When running the stability test, steps 206 through 210 are repeated until a specified number of runs and/or sufficient statistical data is collected. Once the statistics are collected, the autodebug controller 106 calculates the stability statistics (step 211 ) and determines whether the proposed theoretically unflawed test 109 is stable based on the calculated statistics and the stability criteria specified in the knowledge framework 120 (step 212 ). If the proposed theoretically unflawed test 109 is not stable, the autodebug controller 106 returns to step 203 to determine whether more actions are available to try.
[0073] If the proposed theoretically unflawed test 109 is not stable, the autodebug controller 106 determines whether the test should be optimized (step 213 ). If not, the current valid stable proposed theoretically unflawed test 109 preferably is used in place of the received test 102 when testing the DUT 51 (step 215 ).
[0074] If optimization is required, the autodebug controller 106 stores the current valid stable proposed theoretically unflawed test 109 (step 214 ) and returns to step 203 to determine whether more actions are available to try. Steps 204 through 214 are repeated until all actions have been formulated into proposed theoretically unflawed tests and validated/invalidated and stability checks have been performed on the validated proposed theoretically unflawed tests.
[0075] When the autodebug controller 106 determines that no more actions are available to try (step 203 ), the autodebug controller 106 determines whether this point in the process was reached due to optimization or whether it was reached because no valid test could be found (step 216 ). If no valid test could be found, the autodebug controller 106 generates a status indicating that no solution to the received test 102 was found and preferably presents the “best” test in terms of parameters to be used in place of the test 102 presented for debug (step 217 ). If, on the other hand, the autodebug controller 106 tested all possible actions due to optimization, it selects the best valid stable proposed theoretically unflawed test based on validation criteria and how well each of the possible valid stable proposed theoretically unflawed tests meet the validation/stability criteria (step 218 ). The autodebug controller 106 then preferably uses the selected best valid stable proposed theoretically unflawed test in place of the received test 102 when testing the DUT 51 (step 219 ).
[0076] FIG. 12 illustrates an example knowledge framework 220 for a DUT 51 comprising a plurality of components/devices to be tested. As shown in this example, the active rule set is a resistor rule set 222 a . The resistor rule set 222 a includes a plurality of rules 224 a — 1 , 224 a — 2 , . . . , 224 a — n . The test formulation engine 108 processes, in priority order, each 224 a — 1 , 224 a — 2 , . . . , 224 a — n in the active rule set, in the illustrative case, resistor rule set 222 a.
[0077] Below is an example ruleset.xml file illustrating an example rule set definition file. The ruelset.xml file is an XML file that describes the relationship between the device to be tested, the rule set and the rule.
Ruleset.xml <?xml version=“1.0” encoding=“UTF-8” ?> − <Ruleset> + <Device ID=“Jumper”> + <Device ID=“Resistor”> + <Device ID=“Fuse”> − <Device ID=“Capacitor”> − <Ruleset ID=“Joseph”> <Rule ID=“AutoDebug Guards” /> <Rule ID=“Set Amplitude with AutoDebug Guards” /> <Rule ID=“Set Amplitude” /> </Ruleset> </Device> + <Device ID=“Diode/Zener”> + <Device ID=“Transistor”> + <Device ID=“Inductor”> + <Device ID=“FET”> + <Device ID=“Switch”> + <Device ID=“Potentiometer”> </Ruleset>
[0078] A key to the ruleset.xml file describing the contents is shown in TABLE 3.
TABLE 3 Element Attribute Description Device ID Name of device family. Rule set ID Name of rule set in a device family. Rule set name is unique in a device family Rule ID Unique identifier of a rule.
[0079] A rule set consists of rules in terms of running sequence priority. In any given ruleset.xml, there may be multiple rule sets defined, which means that as many rule sets may be defined as needed. Each rule set is tagged to a specific device family. Every rule set will contain rule(s). The rulelD is used to identify the action of the rule as found in rule.xml.
[0080] The rule.xml contains the rule database. Every rule can have its combination of actions and their associated inputs. The inputs represent localized information pertaining to this single action.
[0081] One single action can be applied to different rule with different localized content. The input is a set of criteria that control the behavior of the action algorithm. An action represents a specific set of code that is run in the test formulation engine.
[0082] Below is an example ruleset.xml file illustrating an example rule set definition file. The ruelset.xml file is an XML file that describes the relationship between the device to be tested, the rule set and the rule.
Rule.xml <?xml version=“1.0” encoding=“UTF-8” ?> − <RuleDB> + <Rule ID=“Set Amplitude”> − <Rule ID=“Set Amplitude with AutoDebug Guards”> <Description value=“Setting amplitude” /> <Device ID=“Capacitor” /> <Validation-Gain maximum=“10” minimum=“0.0” name=“Gain” status=“True” /> <Validation-Phase maximum=“20” minimum=“0.0” name=“Phase” status=“True” /> − <Stability> <Status value=“True” /> <CPK value=“1.0” /> <Run value=“5” /> </Stability> <Merge value=“False” /> <Auto-Adjust maximum=“” minimum=“” offset-type=“Percentage” type=“0” /> <Action ID=“1” /> − <Action ID=“2”> <Input ID=“1” value=“1” /> <Input ID=“2” value=“10” /> <Input ID=“3” value=“1” /> <Input ID=“4” value=“1” /> <Input ID=“5” value=“10” /> <Input ID=“6” value=“1” /> </Action> </Rule> + <Rule ID=“AutoDebug Guards”> + <Rule ID=“Enhancement”> + <Rule ID=“Swap S and I”> + <Rule ID=“Swap S and I with AutoDebug Guard”> </RuleDB>
[0083] A key to the Rule.xml file describing the contents is shown in TABLE 4.
TABLE 4 Element Attribute Description Rule ID Unique identifier of a rule. Description Value Rule description Device ID Device that is applicable Validation- Maximum Maximum gain value for validation Gain purposes. Minimum Minimum gain value for validation purposes. Name Name Status Status of the validation item. True False Validation- Maximum Maximum phase value for validation Phase purposes. Minimum Minimum phase value for validation purposes. Name Name Status Status of the validation item. True False Stability Status Status of the validation item. True False CPK CPK value Run Number of run Merge Value Indicator to merge with existing test source True False Auto Adjust Maximum Maximum value for auto adjust Minimum Minimum value for auto adjust Offset-Type Offset value type Percentage Absolute Type Auto adjust type None Test Value Test Limit Action ID Unique identifier for system defined action. Refer to Action Listing for the list of action Input ID Identifier for the input type: e.g.: Lower Range Upper Range Step Resolution Value Value for the input type
[0084] FIG. 13 illustrates an example graphical user interface screen 300 of a preferred embodiment user input GUI for the system of FIG. 8 . As illustrated, the screen 300 includes a rule set panel 310 , a rule database panel 330 , and a rule panel 340 . The rule panel 340 includes a description panel 350 , a validation criteria panel 360 , a stability test panel 370 , and an action panel 380 .
[0085] The rule set panel 310 contains the name of all available rule sets. In the preferred embodiment, the rule set panel 310 lists all devices that may be tested. The list is in the form of a device family tree 312 , which includes three levels of display. At the first, or top, level 312 of the device family tree, the name of the device is listed. At the next level 313 of the device family tree, the name(s) of the each rule set associated with the named device is listed, and at the next, or bottom, level 314 of the tree, name(s) of each rule that is associated with the named rule set is listed.
[0086] Table 5 provides a description of each field on the rule set panel 310 .
TABLE 5 Field Name Description Rule Set List of rule set for each device family. Active Rule set is highlighted with shaded node. Upon clicking on the rule set, the node is expanded to display all rules in assigned priority sequence. Rule List of all rules assigned to the device family. Upon clicking on the rule, the selected rule will be highlighted in the rule database panel. Details of the rule are displayed on the screen. Buttons Button Action Up Arrow Upon clicking on this button, system swaps the selected item with the item above it. This button is disabled if the node is the first node in the level. Down Arrow Upon clicking on this button, system swaps the selected item with the item below it. This button is disabled if the node is the first node in the level. Set Active Upon clicking on this button, if the selected rule set is an active rule set, the rule set is change to in-active rule set. Otherwise, the rule set is set as active rule set This button is enabled if the selected item is a rule set Delete Upon clicking this button, dialog box is display for the user to confirm if he wants to delete the selected item. If Yes, the selected item is deleted from the tree. Otherwise, system does nothing. This button is enabled if the selected item is a rule set or rule. Rename Upon clicking this button, Rename Rule set screen is displayed. This button is enabled if the selected item is a rule set New Upon clicking this button, New Rule set screen is displayed. This button is enabled if the selected item is a device
[0087] The rule database panel 330 lists all rules 331 available for the selected device family 312 . Table 6 provides a description of each field on the rule set panel 330 .
TABLE 6 Field Name Description Device Device Family Name Name Name of the rule Meas Min Lower Limit for Meas Gain Max Upper Limit for Gain Phase Min Lower Limit for Phase Phase Max Upper Limit for Phase Runs Number of runs if the stability is applicable CPK Process Capability if the stability is applicable
[0088] Upon selecting a row in the rule database panel 330 , the details of the rule are displayed in the rule panel 340 .
[0089] Rules are executed according to the sequence shown in the device family tree of the rule set panel 310 .
[0090] The rule panel lists the details of the selected rule. Table 7 provides a description of each field on the rule panel.
TABLE 7 Field Name Description Type Mandatory Device Device Family Dropdown ✓ list Name Name of the rule Varchar ✓ Description Varchar Enable Enable the Boolean parameter. Max Upper Limit Numeric Min Lower Limit Numeric Turn On If the checkbox is ✓, Checkbox stability Test the Min CPK and Runs textboxes are enabled. Otherwise the textboxes are disabled. Min CPK Minimum CPK Numeric ✓ if Turn On stability Test is True Runs Number of runs Numeric ✓ if Turn On stability Test is True Merge With Indicator to merge Checkbox Existing Test with the existing test. The existing test will be treated as an one time action. Assigned List of actions List box Actions assigned to the selected rule. Action is unique in the list. Action List of all actions in List box Database the system, filter by the selected device family. Name Action Name Textbox ✓ (Read Only) Description Action description Textbox Read Only) Type 3 Types of action: Textbox ✓ Iterative Read Only) One-time Dropdown Conditions list. >> if user is allow to change the type of action then dropdown list is to be used. >>Input Different Required ✓ required field Input fields are to be displayed according to the action specification. Buttons Button Action New Upon clicking on this button, all rule fields are open for editing. System is ready to accept new rule. Clear Upon clicking on this button, all rule fields are cleared. Delete Upon clicking on this button, system verifies if the rule is being assigned to any rule set. If yes, prompt user to delete the rule in each rule set. Otherwise, prompt user to confirm the deletion of the rule. If user confirms to delete the rule, the rule is deleted. Otherwise, system does nothing. Assign Upon clicking this button, if rule set is selected on the tree, the rule is added as the last rule of the selected rule set. This button is disabled if it meets any one of the following criteria exists: No rule set or rule selected on the tree The current display rule is assigned to the rule set The rule is not valid rule for the device. Save Upon clicking on this button, the rule informations will be saved. System should check for mandatory information. If the rule is assigned to other rule set, prompt user if he wants to continue as the changes will affect the rulel in other rule set. If Yes, the system saves the information. Otherwise, system does nothing. >> Remove Action from the rule. Upon clicking on this button, the selected Action is removed from the list and added in the Action Database. System search refresh the following: Device family: list of device that is valid for the remaining Actions Action Database: list of device that is valid for the remaining Actions << Assign Action to the rule. Upon clicking on this button, the selected Action is removed from the list and added in the Action Database. System search for the list of device that is valid for the remaining Actions
[0091] In the graphical user interface screen 300 of the user input GUI 7 , actions are predefined, and the user is not allowed to add or change the definition of an action.
[0092] The user input GUI 7 and knowledge framework interface 6 together are used to map knowledge into actions. The user input GUI 7 captures the user input and the knowledge framework interface 6 stores the captured information in the knowledge framework 5 in the format described previously. As described previously, the action framework includes three categories of actions, including one-time, iterative, and conditional. Table 8 lists several types of actions and how they map to the action categories. Other action types may exist.
TABLE 8 AutoDebug Type Categorization 1. Specific Instruction For all actions a. An algorithm b. A known decision making flow c. Fixed stepping of range in a known sequence 2. Range & Step Iterative 3. Range & Step with execution criteria (based on result) Condition (Iterative) 4. Apply offset(+/−) with execution criteria Condition eg change threshold - if measured value falls (One-Time) within an acceptance range, modify the threshold (+/−offset) 5. Choices - (A or B or C) OR all One-Time/ Iterative 6. Set Action (turn this action ON) - no GUI One-time
[0093] It will be appreciated that the above examples, file formats, and layouts are presented for purposes of example only and not limitation. The knowledge framework 120 may be implemented according to any number of different formats and structures and need only include the knowledge for actions and associated validation and optionally stability criteria that may be accessed by the autodebug controller in formulating proposed theoretically unflawed tests for a given component. It will also be appreciated that all of the above methods of operation are typically embodied in one or more computer readable storage mediums that tangibly embody program instructions implementing the described methods shown in the figures. Each of the controllers shown in the figures may be implemented in hardware, software, or a combination of the two.
[0094] It will be appreciated from the above detailed description that the invention provides a technique and knowledge framework that represents the binding of knowledge and experience into a reusable rule format and storage that can be used by a test formulating engine in creating viable tests. The GUI provides a method for binding complex actions into rules and rule sets for tester consumption. In the illustrative embodiment, the technique is applied to allow an automated in-circuit test debugging process to automatically validate and debug automatically generated automated in-circuit tests.
[0095] Although this preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It is also possible that other benefits or uses of the currently disclosed invention will become apparent over time.
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A method for configuring an automated in-circuit test debugger is presented. The novel test debug and optimization configuration technique configures expert knowledge into a knowledge framework for use by an automated test debug and optimization system for automating the formulation of a valid stable in-circuit test for execution on an integrated circuit tester. In a system that includes a rule-based controller for controlling interaction between the test-head controller of an integrated circuit tester and an automated debug system, the invention includes a knowledge framework and a rule-based editor. The knowledge framework stores test knowledge in the representation of rules that represent a debugging strategy. The rule-based editor facilitates the use of rules as knowledge to debug or optimize an in-circuit test that is to be executed on the integrated circuit tester.
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This is a continuation, of application Ser. No. 768,436 filed Feb. 14, 1977 now abandoned.
The present invention relates to improvements in valve assemblies having a valve element which is slidably moveable relative to a valve seat so as to open and close the valve, and where either the valve seat or the valve element has a resilient and deformable valve facing for sealing the closed valve against leakage. Specifically, the invention relates to such valve assemblies in the form of a gate valve and more specifically to the form of gate valves used as a fire hydrant drain valve.
BACKGROUND OF THE INVENTION
For many years valve assemblies have been manufactured wherein the valve seat and its cooperating valve element are movable relative to one another by sliding contact to open and close the valve. One of the members of such a valve has been provided with a resilient and deformable valve facing for providing the necessary seal between the members. The facing is conventionally leather, but rubber has also been used. The valve facing must be deformable since it is necessary for effective sealing that the valve facing be very tightly wedged between the valve seat and valve element and to this end the valve facing in the uncompressed configuration is slightly larger than the available space between the valve seat and the valve element. However, the valve facing must also be resilient since it must again expand to the larger uncompressed configuration when the valve is in the opened position so that it may again be tightly wedged into the space between the valve seat and valve element when the valve is in the closed position. Also, since this wedging action places a severe abrasion or shear force on the valve facing, the material of the valve facing must be abrasion resistant in order to provide a minimum acceptable number of cycles of valve opening and closing. Both leather and rubber have acceptable properties in these regards, but on the other hand, the number of cycles of the valve with these materials is much less than would be desired.
A typical type of valve having a valve facing of the present nature is that of the drain valve of a "dry" barrel type of fire hydrant. These drain valves usually consisted of a drain passage from the exterior of the hydrant through the barrel or shoe and through a portion of the main valve seat assembly, the passage opening into the interior of the barrel at a point above the main hydrant valve when the same is closed. A valve facing strip is carried by the movable main valve element of the hydrant. This strip is arranged to have sliding contact with the valve seat assembly so as to close the opening of the drain passage to the interior of the barrel when the main hydrant valve element is moved to the open position.
Conventional leather drain valve facing strips can function effectively in such service, but they do have the serious disadvantage of deteriorating in time and allowing substantial leaking after a relatively low number of cycles of operation of the valve. Thus, they fail due to lack of continued resiliency and lack of abrasion and aging resistance.
More recently, efforts have been made to utilize drain valve facing strips made of rubber. These strips may be of a solid configuration, i.e. having a uniform cross-section somewhat similar to that of conventional leather facing strips, or they may be of a special configuration so that water pressure on one side thereof provides a seal. Both configurations, however, have not proven to be totally satisfactory when used over long periods of time as they have a tendancy to "cold-flow" and the required overall resiliency is lost and leakage occurs. Further, the rubber tends to deteriorate with age and further lose resiliency and abrasion resistance.
More recently, efforts have been made to utilize valve facing strips made of polyethylene, since this material is substantially more resistant to aging than rubber. These strips may be of a solid configuration similar to the leather strips but the very low order of resiliency of the material results in significant leakage with increased numbers of cycles of operation. In an effort to mitigate this problem, the polyethylene strips have been provided with a recessed configuration on one side thereof in order to increase resiliency. While both of the polyethylene strips provide greater numbers of cycles in drain valves than strips made with leather or rubber, they still have undesired increasing leakage with the number of cycles of operation.
PRIOR ART
Prior art relating to fire hydrants and/or gate valves of the present nature and to articles with a foamed core and solid outer surface (and to processes therefore) are:
U.S. Pat. No. 3,980,096--Ellis et al--September 14, 1976
U.S. Pat. No. 3,751,534--Oxley--August 7, 1973
U.S. Pat. No. 3,662,778 --Leopold Jr., et al--May 16, 1972
U.S. Pat. No. 3,630,098--Oxley--December 28, 1971
U.S. Pat. No. 3,531,553--Bodkins--September 29, 1970
U.S. Pat. No. 3,506,027--Dunton--April 14, 1970
U.S. Pat. No. 3,436,446--Angell--April 1, 1969
U.S. Pat. No. 3,268,636--Angell--August 23, 1966
U.S. Pat. No. 2,996,764--Ross et al--August 22, 1961
U.S. Pat. No. 978,385--Lofton--December 13, 1910.
BRIEF SUMMARY OF THE INVENTION
Broadly stated, the present invention relates to valve assemblies having the valve members of a valve seat and valve element which is slidably movable relative to the valve seat to open and close the valve and a resilient and deformable valve facing on one of the valve members whereby the valve facing contacts the other valve member when the valve is closed to seal the closed valve against leakage. The present improvement relates to the valve facing which is comprised of a foamed polymeric core and an impervious and solid polymeric outer surface which overlays the foamed core at every point where the valve facing contacts the other valve member. The foamed core provides resiliency and deformability and the impervious and solid polymeric outer surface provides abrasion resistance. The polymeric material provides aging resistance. These characteristics are maintained for very long periods of time by virtue of the impervious outer surface.
Although the present invention may be utilized on conventional gate valves, it is of particular utility for use on special gate valves such as that described in U.S. Pat. No. 3,662,778. However, the present invention provides most unexpected results in terms of length of useful service when used as a drain valve facing strip for a drain valve of a fire hydrant, an example of a suitable fire hydrant is that described in U.S. Pat. No. 3,980,096, although the invention is not limited to that particular type of fire hydrant. Nevertheless, for sake of simplicity, the present invention will be described in connection with a drain valve of a fire hydrant, and in particular in connection with the drain valve of the fire hydrant of the foregoing U.S. Patent, but it should be understood that the invention extends to the breadth described above and is limited only by the spirit and scope of the annexed claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a fire hydrant embodying the present invention;
FIG. 2 is a fragmentary vertical sectional view on an enlarged scale of the lower portion of the hydrant of FIG. 1, the view illustrating the main hydrant valve in the closed position and the hydrant drain valve in the open position;
FIG. 3 is an enlarged side elevational view, partly in vertical section, and illustrating the upper valve plate for the main hydrant valve;
FIG. 4 is an elevational view looking from the left to the right of FIG. 3;
FIG. 5 is an enlarged view of the drain valve facing strip of the present invention looking at the side of the same which seals against the drain passage in the hydrant valve seat assembly;
FIG. 6 is a view of the drain valve facing strip of FIG. 5 but looking at the opposite side thereof; and
FIG. 7 is a side elevational view of the drain valve facing strip of the present invention, the view being partly in section taken on the line 7--7 of FIG. 5 and diagrammatically showing the polymeric, foam construction of the same.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like characters and reference numerals represent like or similar parts, there is disclosed in FIG. 1 a fire hydrant generally designated at 10 and having a barrel 12 which is of the sectional type including an upper barrel section 14 and a lower barrel section 16. The upper barrel section 14 is provided with the usual nozzles 18 and with a bonnet or cap 20 through which extends an operating nut 22 operatively connected by means (not shown) to a non-rotating but reciprocating valve stem 24. The upper barrel section 14 is connected to the lower barrel section 16 by the usual frangible connecting ring 26 which is located immediately above the "bury" line 28. A hydrant shoe 30 is detachably connected to the lower barrel section 16 by bolt means 32. (See U.S. Pat. No. 3,980,096 for a detailed description of a typical arrangement of this nature).
As also disclosed in the aforementioned U.S. Pat. No. 3,980,096, the fire hydrant 10 is provided with a hydrant valve seat assembly generally designated at 34 and supported between the lower barrel section 16 and shoe 30, the hydrant valve seat assembly 34 including a brass valve seat ring 36 having a downwardly facing frusto conical seat 38 for cooperating with an upwardly facing frusto conical surface 40 on a main hydrant valve generally designated at 42.
In more detail, the valve seat assembly 34 includes a housing member 44 and a drain ring 46, the drain ring being provided with a drain passage 48. The drain 46 threadably supports the valve seat ring 36 and as fully disclosed in the aforementioned U.S. Pat. No. 3,980,096, the drain ring is provided with at least one lug 50 through which the drain passage 48 extends, the lug 50 being suitably received in a cut-out provided in the housing ring 44. The valve seat ring 36 is provided with drain passage 52 which communicate with an annular drain manifold groove 54 and, thus, it will be appreciated a passageway is provided from the exterior of the hydrant through the passage 48 to the interior of the hydrant through the passages 52 when the main hydrant valve 42 is in the closed position.
Returning now to the description of the main hydrant valve, it includes a lower valve plate 56, an upper valve plate 58 and a valve element 60 sandwiched therebetween, the valve element 60 being made according to the present invention of a foam polyethylene material. The valve element 60 is provided with the frusto conical surface 40 previously mentioned. As will be appreciated, the main hydrant valve 42 is supported on the lower end of the reciprocating valve stem 24 by means of the valve nut assembly 62 and thus when the valve stem 24 reciprocates downwardly, it will cause the main hydrant valve to open to allow water to flow upwardly into the barrel to the hydrant nozzles 18.
As shown in FIG. 2, the annular brass valve seat ring 36 is provided with a pair of oppositely disposed and facing longitudinally extending grooves 64 for receiving ribs 66 (FIGS. 3 and 4) of the upper valve plate 58 and, thus, when the main hydrant valve 42 is reciprocated by the valve stem 24, it cannot rotate relative to the seat ring. The ribs 66 are each provided with a longitudinally extending groove 68 which is dovetail in section and which is arranged to receive elongated drain valve facing strips 70 (FIGS. 5-7), the elongated drain valve facing strips having generally a cross-sectional configuration complimentary to the groove. The drain valve facing strips 70 are secured to the ribs by bronze, stainless steel, or other suitable corrosion resistant screws 72 (FIG. 2). As will now be apparent, when the main hydrant valve 42 is in the closed position, as shown in FIG. 2, the drain passages 52 in the valve seat ring 36 are open to the interior of the barrel 12 above the main hydrant valve 42 since the elongated drain valve facing strips terminate with their lower end just short of the passages 52. Any water in the hydrant can drain through the passages 52 to the manifold 54 and through the passages 48 to the exterior of the hydrant. However, when the main hydrant valve 42 is moved downwardly to an open position, the drain valve facing strips 70 move downwardly with the upper valve plate 58 and cover the drain passages 42 so that water passing through the shoe 30 into the hydrant barrel 12 cannot escape through the drain passages to the exterior of the hydrant.
Valve facing strips 70 are comprised of a foamed polymeric core 81 and an impervious and solid polymeric outer surface 82. The strips may have at least one attaching device receiving aperture 83 for receiving an appropriate attaching means, such as screws 72. The attaching device will secure the valve facing strips to ribs 66. Thus, one side 85 of the valve facing strip 70 contacts and is secured to ribs 66 while the other side 84 of the valve facing strip contacts the valve seat ring 36. Of course, other means of attaching the valve facing strip to the ribs may be used, or additional means of securing or stabilizing of the strips to the ring may be used. In this latter regard, the valve facing strips may have indentations 89 for receiving a guide or stub projecting from ribs 66 (not shown in the drawings). Alternatively, a projection 86 (see FIG. 3) may be provided on the valve strips to mate with a corresponding recess in ribs 66 for providing attachment and/or stabilization of the valve facing strips. For convenience, the valve strips may be beveled as shown at 87 to allow a more gradual contact with the valve seat ring.
As will be appreciated, an important feature of the invention is the critical combination of the foamed polymeric core and the impervious and solid polymeric outer surface which overlays the foamed core at every point where the valve facing contacts the other valve member. In the embodiment of FIG. 7, therefore, outer surface 84 must entirely overlay foamed core 81 so that the outer surface overlays the foamed core at every point where the valve facing contacts the valve seat ring. While not absolutely necessary, it is preferred that the outer surface overlay the foamed core, also, at every point where the valve facing contacts the valve member carrying the valve facing. Thus, in the embodiment of FIG. 7, outer surface 85 would also be an impervious and solid polymeric outer surface, since that entire outer surface will contact the valve member carrying the valve facing, i.e. rib 66.
As noted above, the valve facing may have at least one attaching device receiving aperture which extends from the side of the valve facing contacting one valve member to the side of the valve facing contacting the other valve member. It is not necessary for the outer surface to overlay the foamed core at that aperture, since the foamed core is protected in the aperture by the attaching devices passing therethrough. Nevertheless, it is preferred that the outer surface also overlay that aperture as shown in FIG. 7 at 88. Further, when a plurality of the apertures are provided in the valve facing strip, it is preferred that each of the apertures have the outer surface overlaying the apertures.
It should be understood that the outer surface is comprised of substantially unfoamed polymeric material, but it is not necessary that the outer surface be totally devoid of any foaming whatsoever. For example, the strips may be produced by injecting a foamable polymeric material (containing a blowing agent) into a mold cavity in such a manner that foaming commences during the injection step. Thus, the outer surface will foam, but the mold walls may be maintained at a sufficiently high temperature that the foamed composition will collapse to a non-foamed state when contacting the heated mold walls. While this method produces substantially unfoamed polymeric material in the outer surface, some minor amounts of uncollapsed foam may remain. This will not, however, seriously degradate the desired properties of the outer surface.
However, to avoid even the amount of uncollapsed foam associated with the foregoing process, the foamable composition may be injected at such a rate that foaming is not allowed to substantially take place and the foamable composition will contact cooled mold walls which will prevent the foamable composition from substantially foaming. The interior, remaining hot, however, will foam to provide the foamed core. This process, however, does result in even smaller amounts of foam being contained in the outer surface.
As can be appreciated from the foregoing, both of the described methods of producing the foamed core of the valve facing strip results in the outer surface containing a blowing agent. In one case the blowing agent has foamed and the foam has been collapsed and in the other case, the blowing agent has not been allowed to foam. While the presence of the blowing agent will not normally be of any difficulty, especially in non-corrosive service such as fire hydrants and the like, for special or severe services as may be encountered by other embodiments of gate valves, it might be desirable that the outer surface contain no blowing agent. This can be accomplished by injecting into the mold cavity a first polymeric material containing no blowing agent and then injecting into the first polymeric material a second polymeric material which does contain a blowing agent. Foaming can be accomplished as the two materials expand in the mold cavity or the mold cavity can be filled before any foaming takes place and the mold cavity can then be enlarged to provide foaming. These methods do result in the outer surface having no blowing agent therein.
For the sake of conciseness, these well known methods of injection molding an unfoamed outer surface and a foamed core will not be further discussed, since the details of these processes are well known to the art. However, as examples of such processes, see U.S. Pat. Nos. 3,268,636; 3,436,446; 3,531,553 and 3,751,534.
As can be appreciated, the invention departs significantly from prior art efforts in that the valve facing strip is an integral combination of an unfoamed, impervious and solid polymeric outer surface and a foamed polymeric core. The outer surface provides abrasion resistance so that many cycles of the valve operation may be accomplished without wearing away the outer surface and destroying the sealing effect. However, as noted above, sealing in valves of the present nature require the tight wedging of the valve facing strip between the valve element and the valve seat. The rubber strips of the prior art were deformable so as to allow this wedging, but those rubber strips were not compressible. In other words, the deformable rubber was moved into space available so that overall compression of the rubber could take place. As opposed to that function of the rubber, the present valve facing strips are compressible so that the space actually occupied by the strips under compressive forces is less than the space occupied by the strips under no compressive forces. This is, of course, a well known function of a foamed polymeric material. In a sense, the foamed core acts as resilient springs which allow compression of the outer surface into the available space between the valve element and the valve seat and which function continually urges the outer surface into tight contact with the other valve member to effect excellent sealing of the closed valve.
As can also be appreciated, the foamed polymeric core, while being compressible, has a high degree of resiliency in that it is not necessarily subjected to flow forces as is a solid rubber strip and the foamed core is, therefore, capable of continually restoring the valve facing strip to essentially the same shape of the strip prior to compression. This allows the valve facing strip to be considerably larger than the space available between the valve seat and the valve element, since the foam can be compressed and the strip can still fit into that space. Hence, considerable abrasion of the outer surface can take place and yet the valve facing strip will have sufficient material associated therewith to still cause a tight wedging of the valve facing strip between the valve members and, hence, avoid leakage of the closed valve.
However, to ensure these functions, especially of sufficient compressiveness in the valve facing strip and of sufficient outer surface material to allow reasonable loss thereof by abrasion, it is preferred that the thickness of the foamed core to the thickness of the outer surface which contacts the other valve member (for example surface 84 of FIG. 7) be at least 0.5:1 and preferably at least 1:1. Even better results are provided when that ratio is at least 1.5:1 to 5.0:1.
The outer surface can provide yet a further function. The imperviousness can protect the foamed core from corrosive fluids which may be controlled by the valve. This is opposed to, for example, the situation of a leather valve facing where the fluids being controlled by the valve would ultimately soak into and through the leather valve facings. While this is not a substantial problem in water service, such as in a fire hydrant, even in that environment the impervious surface provides the function of avoiding leakage by virtue of the water passing through the foamed core. If the foamed core is a closed cell core, that leakage will be substantially mitigated, but nevertheless the impervious surface is important in that regard.
While the valve facing may be made of a variety of polymeric materials, it is preferred that the polymeric material be a substantially inert thermoplastic material. Preferably, the core material is selected from the group consisting of polyolefins, nylon, polyvinyl chloride, natural and synthetic rubbers and polyesters. Again, the outer surface material can be selected from any inert thermoplastic material, but it is preferred that the outer surface be made of an abrasion resistant polymeric material and to this end it is preferred that the outer surface material be selected from the group consisting of polyolefins, nylon, polyvinyl chloride, polytetrafluroethylene and polyesters.
The core material may be of a different material than the outer surface material, particularly when the method of forming using a first and second injectable material, as described above, is used. However, the outer surface material and the core material may be of the same polymeric material and this will normally be the case when the other two above-described methods are used for producing the valve facing strip.
The core should be foamed sufficiently to provide the functions described above and the foam expansion is not critical so long as those functions are provided. Sufficient resiliency and compressibility are normally achieved with expansion of as little as 1.5 (the expansion being the ratio of the unfoamed volume of the polymeric composition forming the core to the subsequent foamed volume thereof). However, it is preferred that the expansion be 2.0 or higher, e.g., 3.0 or 4.0 or more. Usually the expansion will be between 5.0 and 12.0, e.g., 5.0-8.0.
The foam may be either open cell foam or closed cell foam, but closed cell foam is preferred, since this provides less chance of liquid penetrating the valve facing.
Foaming may be accomplished with gaseous or chemical foaming agents, e.g., CO 2 , chloro-fluoro-hydrocarbon (Freons), sodium bicarbonate or the conventional diazocarbonamides. The particular foaming agent is not critical and may be chosen as desired.
A full disclosure of suitable blowing agents, polymeric material for the outer surface and polymeric material for the foamed core is contained in U.S. Pat. No. 3,751,534, the entire disclosure of which is incorporated herein by reference and relied upon for details of disclosure.
The following example is illustrative of the invention, but the invention is not limited thereto.
EXAMPLE
Valve facing strips of the configuration of FIGS. 5-7 were produced with a foamed core and solid substantially unfoamed outer surface by injecting polyethylene with diazocarbonamid blowing agent therein into a mold cavity with mold wall temperatures such that any foam on the outer surface of the molding was collapsed. The valve facing strips were attached to a fire hydrant as described in FIGS. 1-4 and the fire hydrant was cycled under water main pressure and the leakage through the test valve was determined at various numbers of cycles of operation of the valve. As comparisons, a valve facing strip of the same configuration was molded of the same polyethylene, but in such a manner that no foamed core was produced, in other words the strip was solid polyethylene. In yet a further comparison, polyethylene valve facing strips were molded with recesses, in the nature as that proposed by the prior art. Finally, to round out the comparisons, conventional rubber valve facing strips and leather valve facing strips were used in the test.
Each of the strip materials were attached to the same kind of fire hydrant, i.e. that described in FIGS. 1-4, and cycled in the same manner. The results are shown in the table below:
______________________________________AVERAGE LEAKAGE IN CC/5 MIN.TYPE OF 0 100 1000+FACING CYCLES CYCLES CYCLES______________________________________Leather 31.5 315.0 NA-Material failsSolid PE 15.6 177.5 212.5Recessed PE .63 1.25 1.05Rubber .70 2.30 1.60Foamed core solidouter surface .20 .20 .20______________________________________
While not shown in the table, the rubber sample actually failed by tearing at 1618 cycles. Additionally, while not shown in the table, the present foamed strip material continued to 17,856 cycles at which number of cycles the average leakage in cc/5 minutes was only 1.0 and at which number of cycles the fire hydrant valving mechanism failed and the valve facing strip was still intact and functioning well. Thus, the present valve facing strip material has a longevity in number of cycles which is greater than the longevity of the mechanical valve assembly.
It should also be carefully noted that the present valve facing strips, initially, had lower leakage than any of the other strips and this lower leakage continued for all of the tested cycles. Indeed, that low leakage rate was maintained throughout the number of tested cycles shown in the table. This is clearly a most surprising and most unexpected result.
The terminology used throughout the application is for the purpose of description and not limitation, the scope of the invention being defined in the appended claims.
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An improved valve facing for one member of relatively sliding gate valve members. More specifically, the improved valve facing has foamed polymeric core and an impervious and solid polymeric outer surface. This combination provides the necessary resilient and deformable characteristics for effecting a long-life seal between the sliding members of the gate valve. When the valve is a drain valve of a fire hydrant most unexpected results are obtained.
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BACKGROUND OF THE INVENTION
1. Industrial Field of the Invention
This invention relates to modified steel slag or iron slag and a method of manufacturing the same, the modified steel slag being slag which is obtained by modifying furnace slag such as iron slag or steel slag, and, more particularly to modified steel slag or iron slag and a method of manufacturing the same, the steel slag being effective for preventing pulverization and generation of yellowish turbid water at the time of contact with water in iron slag or steel slag such as blast furnace slag.
2. Prior Art
A type of steel slag, particularly stainless steel slag, which has a basicity (weight ratio CaO/Si 2 ) of substantially 1.5 or more has a property whereby the 2CaO SiO 2 phase is changed from α-type phase to α'-type phase, and then changed to γ-type phase or β-type phase when the slag is subjected to a cooling-down process. In many cases, when the slag changes from the α'-type phase to the γ-type phase, a volume expansion of substantially 14% results. As is well known, this causes the slag to pulverize into fine particles and thus become dust.
This type of degradation phenomenon worsens the working environment, and disturbs further utilization of slag. These present stainless steel manufacturers with serious problems in regard to the treatment of slag.
It has for a long time been a problem for stainless steel manufacturers to find a method of preventing the degradation of slag and of solidifying it since the discharged slag can be effectively utilized as a secondary material in such applications as civil aggregates for road construction and so on.
Known methods of restricting the pulverization of slag can be exemplified as follows:
○1 . a method in which slag is made into water-granulated glass when the residue slag is discharged;
○2 . a method in which slag is modified to form a material which mainly comprises CaO.SiO.sub. 2 and has a basicity of 1.5 or less (in practice this can be slightly varied due to the composition of the slag);
○3 . a method in which the phase change from α'-type phase to γ-type which results in a great change in density is restricted and the phase change from α'-type phase to β-type phase is activated.
However, in regard to ○1 , at the time of water granulation, phreatic explosion can occur due to the presence of molten metals carried at the time of discharge of the slag, and since water granulated glass is a soft material, it has insufficient strength to serve as a construction aggregate. Therefore, this method ○1 has not yet been put into practical use although it has been partially tested.
In regard to ○2 although some additives designed to modify the properties of SiO 2 containing material have already been placed on the market, they require the installation of supplying facilities and stirring facilities since a large quantity of SiO 2 needs to be employed equivalent to substantially 20% of the fused slag. Furthermore, the viscosity of slag is increased due to the drop in temperature of the fused residue following the addition, and this is not suitable from the viewpoint of workability and total cost.
The method ○3 , that is, bringing about a phase change from α'-type phase to β-type phase has been studied for many years and a variety of methods have been disclosed. One of these methods, which is the most effective and assured method available at present, [see Japanese Patent Laid-Open No. 43690/1978 and the Kawatetsu Engineering Report Vol. 18, No. 1 (1986) 20 to 24 in which Si 4+ ions are replaced by B 3+ ions which have a smaller diameter than that of the Si 4+ ions contained in the slag].
However, the above-described conventional boron type of slag pulverization preventing material is in the form of small powder and dehydration/vaporization reaction occurs at the time of contact with the fused slag since the boronic slag pulverization preventing material is a water containing material. As a result of this, a blowing phenomenon of the slag pulverization preventing material is generated, causing the working environment to become excessively worsened and danger sometimes involved in the work. Therefore operation of the work is very difficult.
Furthermore, since the conventional boron type of slag pulverization preventing material significantly differs in the chemical composition and property from slag, the difference in viscosity and density from the fused slag can be easily generated, that is, a so-called affinity between the slag and the slag pulverization preventing material is not sufficient and thereby the diffusing/mixing performance is insufficient. As a result of such disadvantages, the boron type of slag pulverization preventing material cannot be put into practical use although there have been some disclosures upon it.
A second problem arises in iron slag or steel slag such as blast furnace slag that generation of a so-called "yellowish turbid water" at the time of bringing slag into contact with water such as rain or gutter water.
As is well known, gradually-cooled down slag such as blast furnace slag is widely used as various aggregates, particularly as road beds, that is a so-called "ballast". However, it has been confirmed that if the percentage of sulfur contained in slag is high, a mistake in conditions for use and manner to use it will cause yellowish turbid water and smell of hydrogen sulfide to be generated due to water or gutter water which has been brought into contact with slag. Particularly in order to secure slag quality for road construction to be free from such problem, it is standardized that slag should not generate any yellowish turbid water and smell of hydrogen sulfide. In order to evaluate this fact, a color identification test is employed, and slag should satisfy this test (JIS A 5015 made public on November 1).
A phenomenon of generation of yellowish turbid water is caused from elution of sulfur (S) contained in the form of calcium sulfide (CaS) which is contained, as a major part, in slag, and is due to generation of yellow polysulfide (such as CaSx) after being applied to hydrolysis process. Known methods of preventing generation of yellowish turbid water can be exemplified as follows:
○1 a method in which slag is subjected to aging in which it is oxidized by water and air so that it is stabilized;
○2 a method in which oxidant is added to fused slag;
○3 a method in which slag is treated with CO 2 2 so that the surface of the slag is stabilized; and
○4 a method in which the cooling-down speed of slag is raised.
In regard to ○1 aging treatment takes almost one to three months to be completed, causing a very wide space for storing to be provided.
In regard to ○2 several methods can be exemplified such as a method in which high degree of ferrous oxide is added or a method in which a gas containing oxygen, such as air, is added. However, this method is not preferable since a poisonous SO 2 gas is generated due to the reaction. Furthermore, with this method, the generation of the yellowish turbid water cannot be sufficiently prevented.
In regard to ○3 , although the surface of slag can be stabilized, this method involves a disadvantage that fused sulfides can be again overflowed from a crushed surface when it is crushed at the time of changing pressure.
The method ○4 is a method in which glass is prepared by degrading, diffusing and rapidly cooling down fused slag so that contained sulfur component is prevented from being oozed out. However in regard to ○4 , it involves deterioration in strength and its necessity of granulating to a level below a specific size to form the glass will allow it to be used as a material for small aggregates, but it is very difficult to be used as rough aggregates.
Although another method has been disclosed in which iron, manganese or zinc is, as an effective component, added so that sulfides are fixed, this method has not been put into practical use due to its high cost and insufficient effect.
Therefore, at present, the method ○1 in which slag is subjected to aging is only the available method to prevent generation of slag yellowish turbid water.
PROBLEMS TO BE SOLVED BY THE INVENTION
As can be clearly seen from the above description, this invention is intended to overcome a long time problem of generation of yellowish turbid water from iron and steel slag by means of an industrially low-cost and convenient slag treatment material.
Furthermore, another object of the present invention is to overcome the problem that slag is degraded due to self-decay caused from volume expansion at the time of phase changed in a cooling-down process of the above-described slag.
MEANS TO SOLVE THE PROBLEMS
A group including the inventor of the present invention therefore has studied modification of steel slag or iron slag with a material which in main contains boron, and found a fact that the glass or the sintered body of substances can significantly modify slag and thereby significantly prevent pulverization of yellowish turbid water. As a result of this, the present invention was achieved.
Namely, the present invention relates to modified steel slag or iron slag which is a by-product at the time of metallurgy of steel or iron, this slag being characterized in that it contains at least 0.15 wt% boron component in the form of B 2 O 3 and has resistance against degradation of slag in the cooling-down process of fused slag and against generation of yellowish turbid water at the time of contact between slag and rain water.
Furthermore, this invention relates to a method of manufacturing modified steel slag or iron slag which is characterized by that heat-treated material (called heat-treated material containing boron) which contains, as the effective component, boron at least 10 wt% in the form of B 2 O 3 , and which is sintered or vitrified is added to molten steel slag which is a by-product at the time of metallurgy of steel during operation of blast furnaces, converters or furnaces for manufacturing steel
OPERATION
The modified steel slag according to the present invention needs to contain the component containing boron at least 0.15 wt% in the form of B 2 O 3 .
Furthermore, the modified steel slag according to the present invention can be manufactured by a method characterized by that a heat-treated material containing boron is added to fused steel slag.
In this case, the heat-treated material containing boron preferably contains a relatively high percentage of boron, it being contained, in many cases, about 10 wt% or more in the form of B 2 O 3 , it being contained preferably about 20 wt% or more.
As a material of the type described above, the following material which has been treated with heat are exemplified:
a material which in main contains two-component type borate such as natural or synthetic alkali borate, alkali earth metal borate, borosilicate;
a material which in main contains three-component type borosilicate such as alkali metal borosilicate, alkali earth metal borosilicate;
a material which in main contains alumino-borosilicate; and
a material which in main contains four components that are boron, silicone, alkali metal and alkali earth metal.
The heat-treated material containing boron means a material which contains at least 80 wt% of the above-described main component. In this case, it contains the above-described main component at least 10 wt% in the form of B 2 O 3 , preferably, it contains 20 wt% of the same as the effective component.
Therefore, the other components are allowed to be contained at most 20 wt%, they being exemplified by materials to be involved to be mixed during the preparation of heat-treated material, materials for adjusting properties such as fusing point of glass, the softening point, the viscosity, the surface tension, or materials which can be fixed as sulfides.
Such components can be exemplified by Na 2 O, K 2 O, Li 2 O, CaO, MgO, BaO, SiO 2 , Fe 2 O 3 , Al 2 O 3 , MnO 2 , ZnO, P 2 O 5 , CaF 2 or materials containing these components.
In the above-described materials, the material containing alkali metal borate as the major component, is preferable to be used, from the view point of practical use, that being represented by the following general formula: Me 2 O.B.sub. 2 O 3 (wherein Me represents one or two or more types of alkali metal elements selected from Li, K and Na, and n represents the range of the number of moles between 1 and 10). That containing metallic salts of alkaline earth of borate as the major component is preferable to be used, that being represented by the following formula: MeO.nB.sub. 2 O 3 (wherein Me represents one or two or more alkali earth metal elements, n represents the range of the number of moles between 1 and 5). That containing the borosilicate is preferable to be used, that being represented by the following general formula: SiO 2 .nB.sub. nB 2 O 3 (wherein n represents the number of moles between 1 and 9). That containing borosilicate is preferably to be used, that being in the range that B 2 O 3 : from 10 to 80 wt%, SiO 2 : from 5 to 70 wt%, Me 2 O: from 2 to 50 wt% (however, B 2 O 3 +SiO 2 +Me 2 O≧80 wt%) and the others: 0 to 20 wt%. That containing alkali earth metal borosilicate is preferably to be used, that being in the rage that B 2 O 3 : from 20 to 80 wt%, SiO: from 10 to 60 wt%, Me 2 O: from 5 to 40 wt% (however B 2 O 3 +SiO 2 +Me 2 O≧80 wt%) and the others: 0 to 20 wt%. That containing alumino-borosilicate is preferably to be used, that being in the range that B 2 O: from 20 to 60 wt%, SiO 2 : from 5 to 50 wt%, Al 2 O 3 :from 2 to 20 wt%, Me 2/n 0: from 5 to 50 wt% (wherein Me represents alkalimetal or alkali earth metal, and n represents the valence), (however B 2 O 3 +SiO 2 +Al 2 O 3 +Me 2/n O≧80 wt%) and the others : 0 to 20 wt%. That containing a material containing boron as the major component of four component type is preferably to be used, that being in the rage that B 2 O 3 : from 20 to 60 wt%, SiO 2 : from 10 to 50 wt%, Me 2 O: from 3 to 20 wt%, and MeO: from 5 to 35 wt%.
The reason for the above lies in that all of the above-described materials containing boron can be easily fused and dissolved at the temperature of the fused slag since the fusing point and softening point of them are in the range of about 1100° C. or less, preferably in the range of 700 to 1050C. so that the necessity for the material which has been treated with heat and which contains boron to be quickly dissolved and diffused in the fused slag can be satisfied due to its composition.
The heat-treated material containing boron means here that a material which is obtained by sintering or vitrifying a material which contains boron as the major component so as to be substantially dehydrated. Therefore, sintered materials, vitrified materials and their mixtures can be included in the heat-treated material containing boron, and vitrified materials are particularly preferable for use in the present invention. The vitrification means here that materials are made amorphous to the degree at which it cannot be clearly defined with a specific strength of analyzing rays when X-ray analysis is conducted.
The heat-treated material containing boron according to the present invention is crushed for use, however, this needs to be a material which has been roughly crushed.
Therefore, in many cases, the particle size distribution ranged from from 0.1 mm or larger to a mass whose size is equivalent to the fist or cullets can be used, and more particularly, preferable one being that in which the particle distribution of 0.1 to 50 mm shares 90 % or more.
The reason why the roughly crushed treatment material according to the present invention is required lies in that if the particle size is 0.1 mm or smaller, however depending upon the state how it is added to fused slag, condensation phenomenon occurs between fine particles, causing the material to be prevented from being smoothly fused in fused slag. Furthermore, sometimes non-dissolved mass will be generated, or dust phenomenon will occur at the time of addition in the furnace.
On the other hand, if the size of the roughly crushed treatment material is too large, although effect in uniformly-improving properties of slag can be preferably obtained due to stirring effect caused by addition of it to fused slag, however, if the mass exceeding, in size, a fist or cullet will generate non-fused portions.
Therefore, a material for aid can be, if necessary, mixed with the above-described slag treatment material in order to improve in effects of quickly dissolving, diffusing and mixing with fused slag after the slag treatment material has been added.
Such a material for aid is powder in which dehydrating and/or decarbonizing reaction is generated due to heat applied. Powder of the type described above can be exemplified by one or two or more materials selected from: aluminosilicate such as clay, activated clay, diatomaceous earth; other aluminosilicate such as bentonite, perlite and zeolite; carbonate or bicarbonate such as sodium, potassium, calcium, magnesium or barium carbonate, borate such as Borax, kernite, ulexite, colemanite.
The amount of addition of the above-described material for aid cannot be uniformly mentioned upon types, a method of adding pulverization preventing material, the properties and the state of fused slag. It may be up to 30 wt% with respect to the pulverization preventing material, and is preferably be in the range from 5 to 15 wt%.
The particle size of this material for aid is preferably be smaller than that of the pulverization preventing material, and its means particle size is preferably be smaller than the lower limit of the pulverization preventing material.
The slag treatment material according to the present invention can be prepared by mixing a material which contains, as the effective component, boron, and heating the thus-mixed material so as to sinter or fuse, and then cooling down and crushing the same.
The boronic starting material can be exemplified by a chemically converted material such as boronic acid, sodium borate, mineral borate such as colemanite (Ca 2 B 6 O 11 .5H.sub. 2 O), ulexite (NaCaB 5 O 9 . 8H.sub. 2 O), tincal (Na 2 B 4 O 7 . 10H 2 O), and kernite (Na 2 B 4 O 7 . 4H 2 O). The alkaline material can be exemplified by caustic alkali, alkali carbonate and alkali bicarbonate and so on. The alkali earth metallic material can be exemplified by carbonate, hydroxide, and oxide of alkali earth metal. The silicon material can be exemplified by silica sand, quartz sand, diatom, synthetic silica, slag and clay and the like. Other materials can be exemplified by Fe 2 O 3 , Al 2 O 3 , MnO 2 , P 2 O 5 , fluoride, or a material containing these materials.
The above-described starting materials are properly selected, mixed to become the above-described ratio, and supplied to a required fusing furnace or a calcining furnace so as to be heated/fused or calcined. Next, the thus heat-treated material is subjected to adjustment of particle size after it has been cooled down whereby a desired product can be obtained.
There is no reason for limiting the heating conditions, however, it needs for temperature to be at which the water of crystallization or adhered water can be, of course, substantially dehydrated, at which the particles of the material are calcined each other, and at which they can be fused. Since this temperature differs in accordance with the composition of the material, it may be determined so as to correspond to the specific heat treatment apparatus.
When vitrification is conducted, the most practical method of cooling down the fused liquid is that with tapping the fused liquid, pressure water is applied to crush so as to recover it in the form of sand-shaped glass. Another method can be exemplified by a method in which the fused liquid to be tapped is placed on a belt conveyer so as to be cooled down by water or air so that it is recovered in the form of a cullet.
Next, the particle size is adjusted after conducting drying so as to remove adhered water. However, in case of water-crushed material, particle size adjustment by crushing and screening is not necessarily be needed. Since the material merely dried can per se made a product. Therefore, the particle size adjustment is needed to be conducted if necessary. The sintered material is subjected to particle size adjustment with a provided crasher.
In this case, the above-described material for aid can be mixed if desired.
Slag subjected to the present invention is a type which in main contains basic type calcium silicate which is pulverized to fine particles at the time of cooling down or being subjected to aging, or a type which generates yellowish turbid water when it is brought into contact with water. It generally having basicity (weight ratio CaO/SiO 2 ) is at least 1.3, it being preferably within the range between 1.5 and 3.5. It can be exemplified by blast furnace slag, steel slag such as stainless steel, or converter slag.
The amount of slag treatment material to be added with respect to the amount of slag is not uniform in accordance with the composition, properties and the composition of slag or the like. It is needed to be at least about 0.15 wt% in the form of B 2 O 3 for the purpose of either preventing pulverization of slag or preventing generation of yellowish turbid water, it being preferably be 0.3 wt% or more from the viewpoint of durability of property-improved slag.
The reason for this lies in that; if it is less than about 0.15 wt%, it is not sufficient to prevent generation of yellowish turbid water and occurrence of degradation. Oh the other hand, there is no reason to determine the upper limit. In many cases, it is naturally limited from the viewpoint of economy or affection to molten metal. Therefore, the preferable range from the viewpoint of practical use is from 0.3 wt% to 1.5 wt%.
Slag can be improved in properties by using the slag treatment material according to the present invention without any particular change in the operating conditions in the conventional blast furnaces and steel furnace, and by adding the slag treatment material to fused slag in presence or non-presence of fused metal. It can be understood that it will cause great advantages.
Therefore, when fused slag is delivered from a blast furnace through gutters during which a supplying port being disposed at the desired position through which the slag treatment material is added, the slag treatment material is added at the time of delivery by means of a delivery wheel or the like from a dam disposed in the gutter, or the same is added at the time of delivery together with fused slag.
In a case of manufacturing stainless steel or the like, the slag treatment materials is added, similar to the above description, when the stainless steel is tapped from an electric fusing furnace to a ladle or when fused slag is removed into a slag pot.
In this case, manner of adding the slag treatment material to fused slag is not particularly limited only satisfying the necessity of the slag treatment material should be quickly dissolved and diffused into slag.
For example, a manner can be employed in which the slag treatment material is per se added to fused slag in presence or no presence of hot metal, another method can be employed in which the same is added under air pressure, and other method can be employed in which the same is supplied and added with the same wrapped as it is, and the other method can be employed the slag water is supplied to the state in which the slag treatment material has been previously present.
If the slag treatment material is added to the state in presence of hot metal, the degree of affection such as mixture of boron into the hot metal can be substantially neglectable. This leads a fact that an advantage in application of the slag treatment material according to the present invention.
Therefore, the slag treatment material is only added at the time of discharging to a slag port when the above-described affection can be expected. In the other cases, it is practical to add it to slag in presence of hot metal which has been maintained at high temperature since the viscosity of slag fused liquid is relatively smaller, causing the dissolving and diffusion of the slag treatment material can be conducted quickly, as a result of this, the improvement in properties of slag can be uniformly conducted.
If dissolving and diffusion of the slag treatment material can be insufficiently conducted due to viscosity of slag fused liquid being raised at the time of addition of the same to a slag pot, the above-described material for aid can be, if necessary, added for the purpose of assisting the re-heating or diffusion of slag.
Therefore, it is substantially needless to provided any diffusion means for the purpose of quick dissolving and diffusion after the slag treatment material has been added to fused slag.
As a result of this, slag whose properties have been improved can be obtained by gradually or rapidly cooling down in a normal way after the above-described addition has been conducted.
The effect obtained from the modified steel slag according to the present invention exceeds out expectations such as that the characteristics are changed in such a manner that yellowish turbid water is not substantially generated at the contact with water and furthermore, slag is modified to slag having resistance against the degradation involved at the time of the phase change of slag of this type.
Therefore, modified slag of the type described above can be effectively used as ballasts and artificial stones and can be used as a variety of materials for civil engineering.
The fine particles obtained by crushing of the modified slag according to the present invention exhibits hydraulicity, although it being not uniform upon the composition of slag, so that it can be used as cement having fire resistance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments according to the present invention will now be described.
Example 1
A slag treatment material (No.1) (water crashed material) in the form of sand-shaped glass powder containing boron and having the particle size of -5 mm and having the chemical composition shown in Table 1 is added to the fused slag obtained at the time of tapping from an electric furnace, the slag treatment material being added, in the form contained in 10kg-vinyl bag, at the time of removing slag from a ladle to a slag pot in the ratio of addition shown in Table 2.
TABLE 1______________________________________(weight %)B.sub.2 O.sub.3 CaO SiO.sub.2 Al.sub.2 O.sub.3 MgO Na.sub.2 O______________________________________30.4 29.3 26.1 2.4 1.5 8.3______________________________________
Slag subjected to this process was stood and cooled down in a normal manner and was adjusted in its particle size to become equivalent to MS-25 so that ballast was obtained.
The presence of yellowish turbid water in ballast is measured in accordance with the following evaluation method. The results of the measurement and the chemical composition (weight %) are shown in Table 2.
TABLE 2______________________________________Test No. 1 2 3 4 5______________________________________Amount 2.8 3.0 3.0 2.9 3.3of slag(t/ch)Amount of -- 10 20 30 60addition(kg/ch)Rate of wt % 0 0.33 0.67 1.03 1.82addition Conversion 0 0.10 0.20 0.31 0.55by B.sub.2 O.sub.3Chemical composi-tion of slag (wt %) CaO 27.1 24.7 27.8 28.0 25.6 SiO.sub.2 20.6 20.0 20.6 21.4 20.3 MgO 15.6 11.0 16.8 15.4 19.7 Al.sub.2 O.sub.3 28.5 34.8 25.7 25.4 26.1 MnO 1.2 1.6 1.1 0.8 1.3 TiO.sub.2 0.7 0.8 0.5 0.5 0.6 FeO 2.2 0.9 2.6 1.1 2.3 S 1.98 2.08 2.39 2.73 2.04 P 0.005 0.005 0.005 0.005 0.005Color Indentification 5.0 0.5 0 0 0Test (yellow index)Remarks Cont. Comp. E E E______________________________________ (Cont: Contrast example, Comp: Comparison example, E: Example)
Method of evaluating yellowish turbid water
The thus-obtained 500g of sample ballast is weighed, is placed in 1500 ml of pure water, and is boiled for 45 minutes in accordance with color identification test per JIS A5015. The filtered eluate is taken in a color comparing tube so as to be visually tested with reference to color reference liquid upon the presence of color. In order to numerize the degree of darkness or lightness of the color of the eluate, that is the degree of the hue of the eluate, the absorbance of the reference liquid and the eluate are measured with an absorbance meter. The results were evaluated with the thus-obtained yellow index as shown in Table 3.
TABLE 3______________________________________ Density of potassium Absorbance bichromate referenceHue Yellow Index (-log T) liquid (g/l)______________________________________colorless 0 0.022 or less 0.002 or lessalmost 0.5 0.022 to 0.064 0.002 to 0.006colorlessextremely 1.0 0.064 to 0.113 0.006 to 0.011light yellowvery light 1.5 0.113 to 0.181 0.011 to 0.018yellowslightly 2.0 0.181 to 0.30 0.018 to 0.032light yellowLight yellow 2.5 0.30 to 0.46 0.032 to 0.052Yellow 3.0 0.46 to 0.80 0.052 to 0.10Slightly 3.5 0.80 to 1.02 0.10 to 0.17dark yellowdark yellow 4.0 1.02 to 1.09 0.17 to 0.30very dark 4.5 1.09 to 1.16 0.30 to 0.45yellowbrown 5.0 1.16 or more 0.45 or more______________________________________
As can be clearly seen from the Table 2, the eluent amount of sulfur is reduced due to addition of the slag treatment material, and the yellow index became 0 in this Example in which 0.20 wt%, which is the amount converted to B 2 O 3 , is added, as a result of this yellowish turbid water was prevented from being generated.
Example 2
The slag treatment material similar to that according to the Example 1 was added by 3 kg, 5 kg and 7 kg with respect to a ton of fused slag to fused blast furnace slag flowed from a blast furnace.
This slag treatment material was added at certain intervals in the form enclosed in each 10kg vinyl bag at the time of dropping of slag from an inclined gutter to a slag vehicle through a slag gutter in a casting bed disposed in front of the furnace.
This addition work is not limited to the description above, the slag treatment material may be previously enclosed in the slag vehicle or it may be directly added to the flow of fused slag passing through the slag gutter by using a device for cutting the constant quantity of slag.
The slag which has been subjected to the addition process is conveyed to a field for slag so that it is subjected to a normal field-process in which it is cooled down, and is divided into powder and the particle size was adjusted. As a result of this, ballast of MS-25 was obtained.
A sample was obtained from each ballast and yellow index was obtained in a manner similar to that shown in Table 2 according to the Example 1. The results shown in Table 4 was obtained.
For the sake of comparison convenience, the results of a contrast example in which the slag treatment was not used are also shown on the Table 4. In comparison to this contrast example and comparison example, it can be clearly understood that the effect of the present invention is significant.
TABLE 4______________________________________Test No. 1 2 3 4______________________________________Amount of slag(t/pan) 35 35 35 35Amount added(kg/pan) 0 110 180 250% 0 0.31 0.51 0.71Rate of additionAmount converted 0 0.10 0.16 0.22to B.sub.2 O.sub.3Color identification test(Yellow index) 4.5 1.5 0 0Remarks Cont. Comp. Ex. Ex.______________________________________
Meanwhile, it cannot be said that the present invention is achieved successfully if yellowish turbid water is again generated from the blast furnace ballast due to the storing or aging or characteristics for uses as roadbeds are excessively deteriorated in a case where slag treatment material is added to fused steel slag for the purpose of preventing generation of yellowish turbid water and so on.
Therefore, the relationship between the yellow index and the unconfined compression strength of the characteristics for use as roadbeds and aging is examined in accordance with JIS A 5015 with ballast shown in Table 4 used. The results are shown in Table 5.
TABLE 5______________________________________ Unconfined compresion Color strength (kg/cm.sup.2)Rate of addition Aging Indentification (standing for 13of treatment time test (Yellow days, dipping inMaterial (%) period index) water for 1 day)______________________________________No addition 0 4.5 17.6ContrastExample 1 month 3.0 14.3 2 months 1.5 14.7 3 months 0 13.20.31 0 1.5 20.0ComparisonExample 1 month 0.5 19.3 2 months 0 18.6 3 months 0 16.90.51 0 0 18.7Embodiment 1 month 0 18.0 2 months 0 18.2 3 months 0 17.10.71 0 0 19.4Embodiment 1 month 0 18.6 2 months 0 17.8 3 months 0 17.3______________________________________
As can be clearly seen from the Table 5, in comparison to the contrast example and the comparison example, this invention showed excellent result in such a manner that the yellow index showed no problem without any necessity of aging and unconfined compression strength also showed moderate deterioration with respect to the contrast example.
Example 3
The presence of yellowish turbid water was measured in modified slag manufactured by adding, to fused slag, slag treatment materials which comprise 2-component type heattreated material containing boron whose compositions are shown in Table 6.
______________________________________Slag treatmentmaterial No. Composition Remarks______________________________________2 Na.sub.2 O.4B.sub. 2 O.sub.3 sandy glass powder3 CaO.4B.sub. 2 O.sub.3 sandy glass powder4 SiO.sub.2 .7B.sub.2 O.sub.3 cullet5 SiO.sub.2 .7B.sub.2 O.sub.3 sintered powder______________________________________
That is, the above-described slag treatment materials were respectively added to fused slag at the time of tapping from electric furnace for steel by a predetermined quantity (0.3 to 0.4 wt%) in the form of B 2 O 3 in such a manner, similar to the Example 1, that it is enclosed in a poly-bag at the time when slag is removed from ladle to a slag pot. Slag subjected to this modifying process was subjected to a normal standing/cooling process and the particle size of the same is adjusted to meet MS-25 for the purpose of making it ballast.
The generation of yellowish turbid water from the thus-obtained ballast is measured with an evaluating method similar to the Example 1. The result is that any ballast obtained by using each slag treatment material was modified to ballast having the yellow index less than 0.5. On the other hand, the ballast to which no slag treatment material added showed yellow index of 5. The outline of the chemical composition of the modified ballast was as shown in the following table.
TABLE 7______________________________________(weight %)B.sub.2 O.sub.3 CaO SiO.sub.2 MgO Al.sub.2 O.sub.3______________________________________0.32 to 0.50 24 to 20 20 to 21 11 to 20 25 to 35______________________________________
Example 4
Modified slag was manufactured, similarly to the Example 1, by using a multicomponent type of heat-treated material containing boron whose composition is shown in Table 8.
TABLE 8______________________________________Slag treatmentmaterial B.sub.2 O.sub.3 Na.sub.2 O CaO BaO SiO.sub.2 Al.sub.2 O.sub.3 F______________________________________No. 6 63 28 97 59 15 27 10 28 55 3 35 10 29 36 10 39 1010 45 2 15 35 5 2______________________________________ Note: No. 1 is a sintered material of 0.1 to 5 mm, Nos. 2 to 5 are glass crushed materials, No. 2 is cullet, and others are sandy glass powder
That is, the above-described slag treatment materials were respectively added to fused slag at the time of tapping from electric furnace for manufacturing steel by a predetermined quantity (0.3 to 0.5 wt% in the form of B 2 O 3 in such a manner, similar to the embodiment 1, that it is enclosed in a poly-bag at the time when slag is removed from ladle to a slag pot. Slag subjected to this modifying process was subjected to a normal standing/cooling process and the particle size of the same is adjusted to meet MS-25for the purpose of making it ballast.
The generation of yellowish turbid water from the thus-obtained ballast is measured with an evaluating method similar to the Example 1. The result is that any ballast obtained by using each slag treatment material was modified to ballast having the yellow index less than 0.5. On the other hand, the ballast to which no slag treatment material added showed yellow index of 5. The outline of the chemical composition of the modified ballast was as shown in the Table 7.
Example 5 (slag pulverization resistance test)
When stainless steel slag having basicity (CaO/SiO 2 =2.10) which is the first slag tapped from an electric furnace for manufacturing stainless steel (capacity: 30 tons) is removed from a ladle to a slag spot, each poly vinyl bag accommodating 10kg of the test sample of each slag treatment material which is used in the embodiments 1 to 4 is supplied up to 30kg simultaneously. Next, the thus-supplied slag was allowed to stand at low temperature to make it solid. The process until the temperature reaches room temperature was observed.
The test conditions are as follows:
TABLE 9______________________________________ Amount B.sub.2 O.sub.3 of Amount of contained TemperatureTest Sample tapping sample added in slag at tappingNo. No. (t) (kg/t slag) (wt %) (°C.)______________________________________1 1 2.40 12.51 0.38 14402 2 5.20 5.76 0.47 14203 3 4.95 6.06 0.50 14204 4 5.22 5.75 0.51 14005 5 5.22 5.75 0.51 14306 6 3.99 7.52 0.47 14207 7 3.69 8.14 0.48 14408 8 3.27 9.17 0.50 14409 9 2.09 14.37 0.51 143010 10 2.90 10.33 0.46 141011 -- 4.12 0 0 143112 -- 4.07 0 0 140613 -- 3.99 0 0 1413______________________________________
At the time of addition of each test sample, all of the tests did not show any generations of dust and gases, and the addition work could be conducted safely. An excellent diffusion and mixture could be obtained at the time of supplying slag to the slag pot.
After allowing to stand each slag after the test, the state of the slag was observed. Slag with test Nos. 1 to 10 did not show any decay and degradation.
On the other hand, conventional slag with the test Nos. 11 to 13 to which no slag treatment material was added was decayed and degraded when it was cooled down.
The outline of the analyzed value (weight %) of slag used in the test is as follows:
______________________________________Test No. Cao SiO.sub.2 MgO Al.sub.2 O.sub.3______________________________________1 to 13 48 to 55 22 to 28 9 to 13 9 to 15______________________________________
In each test, no dust generation was observed due to supply of test sample, and the test sample was instantaneously splashed and flowed on fused slag. The state was observed after slag has been allowed to stand until room temperature. No decay and degradation phenomenon were not observed. It was found that excellent effect can be obtained by using 0.38 to 0.50 wt% of B 2 O 3 .
Effect of the Invention
The modified steel slag according to the present invention is a steel slag which can substantially prevents generations of gradation phenomenon and yellowish turbid water which have been a problem for a long time for steel manufacturing industrial field.
Therefore, the modified slag can be advantageously applied to ballasts or artificial stones used for a variety of civil engineering materials.
Furthermore, fine powder of the modified slag can be effectively used as an advantageous cement material due to its hydraulicity and fire resistance.
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A steel slag or iron slag which is a by-product generated at the time of steel or iron metallurgy and a method of manufacturing the same are disclosed. This slag is characterized in that it contains at least 0.15 wt % of boron component in the form of B 2 O 3 and has resistance against degradation in the fused slag cooling-down process and against generation of yellowish turbid water at the time of contact of slag with rain water.
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BACKGROUND
[0001] The game of standard marbles is not featured for larger, easy-to-use components and a bigger playing area. It is not very user-friendly and the standard marbles are tiny and cumbersome for small children, disabled adults, or the elderly. Therefore, it is desired to have a game that can work on grass, dirt, pavement, or any large area for small children, disabled adults, or the elderly would be able to enjoy this time-honored amusement without struggling with tiny, cumbersome marbles.
BRIEF SUMMARY OF THE INVENTION
[0002] This invention is directed to a method and an apparatus of rolling battle game. To play the game, players would first choose an area, indoors or outdoors, such as a patch of lawn in the front or back of the house, for setting up the game apparatus that comprises a plurality of balls and three discs with centric hole for receiving the balls. Next, players would select a ball for play. Players position themselves at a distance away from the target disc, each player in turn would roll their ball toward the hole in the disc. The object of rolling battle game is to keep opponent players from rolling their balls into the base goal by knocking their ball out of the way and getting one's own ball into the goal. The first player to reach base is the winner. Each player thereafter to reach base goal will be consecutive runner-up.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a top view of disc;
[0004] FIG. 2 is a perspective view of whole disc (Total of 3 discs) Numbered 1, 2 & 3;
[0005] FIG. 3 is a perspective view of game illustration; and
[0006] FIG. 4 is another perspective view of game illustration;
DETAILED DESCRIPTION
[0007] Roll battle was created for two to six players, ages 5 and up. It is designed to be played on a flat surface. Referring to FIG. 1 and FIG. 2 , in one embodiment, the roll battle game 10 comprises a plurality of balls 32 and three circular discs 11 , 12 , 13 , of which each contains a centrically placed hole 14 about 6″ in depth, as receptacle for receiving the balls 32 . The discs 11 , 12 , and 13 each has a outer edge 16 would angle up slightly to an inner edge 18 , which surrounds the circumference of the center hole 14 . In another embodiment, the game comprises a plurality of balls and three artificial turf pads, such as Astro Turf®, in a shape of circle or square, of each a centrically placed receptacle about 6″ in depth for receiving the balls. The artificial turf pad surrounds the circumference of the center hole and angle up slightly from the outer edge of the artificial turf pad toward the hole. Referring to FIG. 2 , in one embodiment, the balls can be any size, but preferably are from the size of a pool ball, for older players, to the size of a Ping-Pong ball, for younger players. both sizes should be hard not bouncy. The balls would be made of rubber with a plastic coating. Referring to FIG. 3 , the distance between the three discs can be adjusted to the age range of the players simply by making the discs or artificial turf pads closer or farther apart. The discs or artificial turf pads would be numbered 1-2-3, and the holes in the respective discs will be called hole #1 11 , hole #2 12 , and hole #3 13 .
[0008] Referring to FIG. 4 , in one embodiment of playing the rolling battle game 10 by three players 41 , 42 , and 43 , the players can decide how many times to go up and down before calling hole #1 11 the base or the base goal. This has to be decided before the game begins. Player 1 41 would stand at hole #1 11 and toss his ball 32 try to enter hole #3 13 . If the player 1 41 gets the ball in the hole he will go to hole #3 and take his ball out because he has conquered that hole and will stand away. The player 2 42 would toss his ball 32 and if he does not get the ball 32 in the hole #3 13 , his ball would stand where the ball stops. The player 3 would then try. If he get the ball in, player 1 would take his ball and say out loud, “striking ball two”, and strikes player 2's ball away from hole #3. Player 1 41 would stand by hole #3 and try to get their ball into hole #2. If he doesn't get his ball in, the ball stands where the ball stops. Player 2 42 would stand wherever his ball would roll and then try to get into hole #3 13 . If player 2 42 does not get his ball in, player 3 43 would strike ball 2 saying out loud “strike ball 2”. From hole #3 13 , player 3 43 would try to roll his ball into hole #2 12 . If player 3 43 gets his ball to hole #2 12 , they would decide if player 1's 41 ball is too close to hole #2 12 . If it is, player 3 43 would strike the ball and say out loud “striking ball 1”. Then player 3 43 would proceed to hole #1 11 . If player 3 43 does not roll his ball into hole #1, the his ball stands where the ball stops. Player 1 41 wherever his ball rolled to would proceed to hole #2 12 . If player 1 41 does not get it in the ball stands where the ball stops. Player 2 42 would then toss his ball to hole #2 12 , and gets the ball in the hole. If he decides that player #1 41 is too close to hole #2 12 , he would strike player 1's ball away from hole #2 12 saying “striking ball 1” and proceed to hole #1. If player 2 gets his ball in hole #1, he would become the guard for hole #1, which would be considered base. He would then strike player 3's 43 ball away from the base 11 . Player 3 would try to enter hole 1 11 . If he does not get it in hole #1 11 , he would be struck again. Player 1 41 would try to enter hole #2 12 . If player 1 does not get in, player 2 would stand by the base, which is hole #1 11 , and strikes player 1's ball away from hole #2 12 , and so on until all players have their balls in base 11 , which is hole #1.
[0009] The object of Rolling Balls is to keep opponents from entering the base goals by knocking their balls out of the way and getting one's own ball into the goal. Play continues in a similar fashion until a winner declared.
[0010] There are many significant benefits and advantages associated with the rolling battle game.
[0011] Foremost, this game would offer consumers hours of competitive and challenging fun. A game of strategy and skill, rolling battle game would provide players with a means of stimulating the mind, honing their thought process, and improving hand eye coordination. Offering a reprieve from the stresses of daily life, this exciting game would encourage positive social and family interaction through good-natured competition. With simple to follow instructions, the rolling battle game can be enjoyed by children as well as adults. Moreover, the larger balls and playing area offered with this game make the rolling battle game is a more user friendly game than the similarly-themed standard balls, in that small children, disabled adults, or the elderly would be able to enjoy this time-honored amusement without struggling with tiny, cumbersome balls. Consumers will also appreciate the versatility of the rolling battle game, as it could be played indoors or out. Containing minimal components, this unique game would be packaged as a compact foldable unit, providing easy storage as well as transport. The rolling battle game is a cleverly designed product invention that would offer players a fun and exciting game of strategy. Both simple and challenging, this entertaining game would effectively foster camaraderie and competition as it is played. Affordably priced, The rolling battle game will be well received by the vast number of consumers who enjoy playing games, such as horseshoes, washers, bachi-ball and croquet among other games, a very sizable and profitable market.
[0012] In one embodiment of the apparatus and the method of the rolling battle game, the rolling battle game is designed to be played on a flat surface, particularly outdoors. In one embodiment, this game comprises of three circular dish section of plastic each containing a centrically placed receptacle measuring 6″ in depth.
[0013] Referring to FIG. 4 , in one embodiment, each player, 41 , 42 , and 43 would select a ball. Then positioning themselves at a distance approximately 12 feet away from the holes. Each player in turn would roll his or her ball towards the hole 13 in the plastic receptacle. The object of the rolling battle game is to keep opponents' balls from entering the goal hole by knocking their ball out of the way and getting one's own ball into the goal. Each successful goal gets the player closer to the base hold. The first player to reach base is the winner each player therefore reaches base goal will be consecutive runner-ups. The rolling battle game can be made square or circle with hole in the center game balls can be made any size. Rolling Balls is an interactive game that is similar in concept to the game of standard balls, but features larger, easy-to-use components and a bigger playing area. Designed to be played on a flat surface, particularly outdoors, this game would basically be comprised of three, 2 square feet sections of artificial turf. each containing a centrically placed receptacle measuring 6″ in depth. For play, the balls would be enlarged balls, basically the size of a billiard ball and for younger players the size of a ping pong ball.
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An apparatus for a roll battle game apparatus comprises three receptacles and a plurality of balls; and a method of rolling battle game comprising the steps of providing directing a plurality of players to roll the ball toward the third hole; directing the player to either to toss the ball toward the third hole or to strike the ball of next another player; directing the player to skip to the turn and leave the ball where it stays when the player misses the ball to strike; repeating the step of either rolling the ball toward the next hole or striking a ball of next another player until the remaining players all roll the ball into the next hole; the first one to roll balls into the base goal is the winner.
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This application is a continuation-in-part of PCT Application No. PCT/US2009/056029, filed Sep. 4, 2009, which claims the benefit of U.S. Provisional Application No. 61/094,253, filed Sep. 4, 2008.
FIELD OF THE DISCLOSURE
The present disclosure relates to lighting devices. More particularly, the present disclosure relates to an efficient signal lamp for controlling the light coming from a relatively small light source.
BACKGROUND
The current construction of signaling lamps allows for the control of light by employing multiple lenses, including a first converging lens and a second diffusing lens (see FIG. 1 ). For example, U.S. Pat. No. 5,947,587, which is incorporated by reference herein, discloses a signal lamp comprising a box-shaped housing 1 having an open end 2 that is closed by a spreading window 3 . LEDs 4 are clustered around a central axis 6 of the housing 1 and a positive lens 7 , which is described as a fresnel lens, is interposed between the spreading window and the LEDs.
LEDs 4 are disposed in an array having a surface area that is 25% of the surface area of the Fresnel lens 7 . The Fresnel lens 7 acts to converge the light beam pattern and then the spreading window 3 diffuses the light. Using two optical elements, i.e., the Fresnel lens and the spreading window, results in light loss through the two optical components. Furthermore, two separate optical components are required to be manufactured and assembled into the signal lamp, adding to the manufacturing cost and efficiency of the LED signal.
Accordingly, it is desirable to develop an efficient signaling lamp that diffuses the light before converging the light so as to control the distribution of light onto the field, while using less plastic parts.
BRIEF DESCRIPTION
In one embodiment a lighting device is provided. The lighting device includes a housing with an open end, a refractive optical element closing the open end of the housing and including a converging outer surface and a diverging inner surface, and a light source cooperating with the refractive optical element. The light source is disposed proximate the focal point of the refractive optical element. The optical element may include an inner surface having a reference plan normal to the trajectory of the incoming light rays. Alternatively, the optical element may include a collimating lens, the inner surface being configured to be planar and normal to light rays emanating from the light source and the outer surface being configured to redirect light rays to provide a generally collimated light beam pattern.
In another embodiment, a lighting device is provided. The lighting device includes a housing having an open end and a geometrical axis and at least one light source disposed along an optical axis. The lighting device further includes an outer optical element having a focal point and closing the open end of the housing, the optical element comprising a converging outer surface and a diverging inner surface that cooperates with the light coming from the inner optical element. Additionally, the lighting device includes an inner optical element between the light source and the outer optical element, the inner optical element redirecting light from a light source that is offset from the focal point toward the outer optical element. The outer and inner optical elements may be rotationally symmetrical about the geometrical axis. The inner surface of the outer optical element may be facetted and the outer surface of the outer optical element may be smooth. The light source may include a first and second light source, the first light source being disposed closer to the inner optical element than the second light source. The outer optical element may be configured to cooperate with a second light source to provide a generally collimated light beam pattern.
In yet another embodiment, a lighting device is provided. The lighting device includes a housing having an open end and at least two converging lenses. One converging lens is positioned to collect most of the light from a light source and another converging lens is positioned to close the open end of the signal lamp and distribute the light for a given specification. Optionally, at least one light source is disposed along an optical axis and the housing has a geometrical axis.
In yet another embodiment, a lighting device is provided. The lighting device includes a housing having an open end, a light source, and a converging lens. The converging lens includes a curved entry face, a total internal reflection face and an exit face, wherein the curved entry face is configured to converge the light from the light source toward the center of the total internal reflection face.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, sectional view of a prior art signal lamp.
FIG. 2 is a schematic, sectional view of a signal lamp having a positive lens with a far side converging surface.
FIG. 3 is a schematic, sectional view of a second embodiment of a signal lamp having a positive lens with a faceted inner surface that is moldable.
FIG. 4A is a schematic view of two optical elements cooperating with a light source for use in a third embodiment of a novel signal lamp.
FIG. 4B is an alternative schematic view of two optical elements cooperating with a light source for use in an embodiment of a novel signal lamp.
FIG. 5 is a side view of the lens shown in FIG. 3 cooperating with a light source.
FIG. 6 is an optical simulation ray tracing screen shot of the optical element shown in FIG. 5 .
FIG. 7 is a schematic, vertical sectional view of the distribution curve reference to the inner reference plane.
FIG. 8 is a partial side view of an exemplary lens in accordance with aspects of the present disclosure.
FIG. 9 is a sectional view ray diagram of a TIR element showing a curved entry face embodiment.
FIG. 10 is a sectional view ray diagram of a TIR element having a mold machining radius.
FIG. 11 is a schematic, sectional view of a signal lamp in accordance with aspects of the present disclosure,
DETAILED DESCRIPTION
One or more implementations of the present disclosure will now be described with reference to the attached drawings, wherein like reference numerals are used to refer to like elements throughout.
FIG. 2 discloses a signal lamp 8 including a refractive optical element 10 , which is shown as being a collimating lens, cooperating with a point light source 12 at a focal point of the optical element. The collimating lens 10 includes an inner surface 14 and an outer surface 16 . The inner surface 14 is shaped so that it is normal to light rays 18 emanating from the point light source 12 so that minimal or no refraction of these incoming light rays occurs at the inner surface 14 . The outer surface 16 is configured to redirect light rays to provide a generally collimated (parallel or nearly parallel) light beam pattern. For example, where most of the light rays are within about 20° beam angle is considered appropriate to form a nearly collimated (nearly parallel) beam pattern.
FIG. 2 also schematically depicts a support 22 for a plurality of LEDs 24 . The virtual point light source 12 , as mentioned above, is disposed at the focal point for the lens 10 . The support 22 , which in the depicted embodiment is a printed circuit board, is offset inwardly from the focal point for the collimating lens 10 and situated perpendicular to a central axis 26 . The LEDs 24 are clustered around the central axis 26 of the collimating lens 10 , which can also be a central axis of a signal lamp housing 28 that includes the LEDs 24 and the collimating lens 10 . The housing 28 for the signal lamp has an open end that is closed by the collimating lens 10 . The LEDs 24 on the support 22 are near enough the central axis 26 and set inwardly from the focal point of the lens 10 to generate a beam pattern that is similar to the beam pattern that is generated by the virtual point light source 12 .
FIG. 3 depicts an alternative embodiment of signal lamp 48 . FIG. 3 depicts a refractive optical element 50 cooperating with a virtual point light source 52 that is disposed at a focal point for the optical element. The lens 50 can be rotationally symmetric about a central axis 66 . If it is desired to create an asymmetric beam pattern, then an inner surface 54 of the lens 50 can be disposed in a pattern, e.g. a radial or linear (square or diamond) pattern. The optical element 50 includes the inner surface 54 and the outer surface 56 . In contrast to the embodiment shown in FIG. 2 , the inner surface 54 is configured similar to a fresnel lens where the inner surface is facetted. The inner surface 54 is facetted in such a manner, however, that the refractive optical element 50 can be injection molded. In doing so, the substantially horizontal portions of each facet (per the orientation shown in FIG. 3 ) are at least substantially parallel to the central axis 66 of the optical element 50 and the signal housing 68 or at an angle such that the optical element 50 can be ejected from a mold. For example, the horizontal portions 58 of each facet slopes away from a line parallel to the central axis 66 , which coincides with the ejection direction from the mold, from an innermost edge 62 of the horizontal portion in a direction towards an outermost edge 60 of the horizontal portion.
Each facet also includes a generally vertical portion 64 to refract the light towards the outer surface 56 of the optical element 50 . The outer surface 56 is configured to narrow to beam pattern. If the surface 54 is normal to light coming from the point source, the outer surface 56 , similar to the outer surface 16 described above, is configured to redirect light rays to generate a generally collimated (parallel or nearly parallel) light beam pattern. For example, where most of the light rays are within about 20° beam angle is considered to be appropriate to form a nearly collimated (nearly parallel) beam pattern. Developing an asymmetric beam is described with reference to FIG. 7 , below.
FIG. 3 depicts a support 72 disposed in the housing 68 and a plurality of LEDs 74 disposed on the support. The LEDs 74 and the support 72 are spaced inwardly from the virtual focal point 52 of the lens 50 similar to the embodiment shown in FIG. 2 . The support 72 can be a printed circuit board and be situated substantially perpendicular to the central axis 66 . The LEDs 74 are clustered around the central axis 66 . Similar to U.S. Pat. No. 5,947,587, the surface area of the footprint for the LEDs 74 can be about 25% of the surface area of the refractive optical element 50 .
FIG. 3 discloses light rays 76 that emanate from a virtual point light source disposed at the focal point 52 of the refractive optical element 50 . By spacing the LEDs 74 and the support 72 inwardly from the focal point 52 toward the refractive optical element 50 the rays emanating from the LEDs can follow substantially the same path as the light rays 76 shown for the virtual point light source 52 .
FIG. 5 discloses a side view of the lens 90 shown in FIG. 3 cooperating with the single light element 92 and the light rays 94 emanating from the single light element. The single light element 92 is situated at the focal point for the lens 90 , similar to the virtual point light sources described above. In a similar manner to the signal lamps disclosed above, a plurality of LEDs can be clustered around a central axis of the lens 90 offset inwardly from the virtual focal point to generate a beam pattern that closely approximates the beam pattern shown in FIG. 5 . FIG. 5 more accurately depicts the substantially collimated light beam pattern in that the light rays are all not precisely parallel to one another but instead are substantially parallel to one another to generate a generally or substantially collimated light beam pattern. FIG. 6 is a close-up view of a cross section taken through FIG. 5 .
FIG. 4A depicts a schematic sectional view of two refractive optical elements 100 and 102 and two virtual point light sources 104 and 106 . Each point light source 104 and 106 is disposed along an axis 108 which is centered within respect to both of the optical elements 100 and 102 . The optical element 102 can be rotationally symmetrical about the central axis 108 . If, however, an asymmetric beam pattern is desired, the optical element 100 may not be rotationally symmetrical about the central axis 108 .
The outer refractive optical element 100 includes an inner facetted surface 112 and an outer smooth surface 114 . The inner facetted surface 112 is similar to the facetted surface described with reference to FIG. 3 in that it is similar to a Fresnel style but is able to be injection molded. The outer optical element 100 is configured to cooperate with the furthest virtual point light source 104 to provide a generally collimated beam pattern similar to the embodiment shown in FIGS. 2 and 3 . The outer optical element 100 closes the open end of a signal lamp housing (not shown) similar to the optical elements 10 and 50 described above.
The inner optical element 102 is used to create a virtual far focal point for the optical element 100 . The optical element 102 is also used to improve the efficiency of the signal lamp by collecting all, or nearly all, the light for the LED point light source. The optical element 102 reduces the thickness of the signal lamp. The optical element shown in FIG. 3 is shown as a positive lens; however, the optical element can be designed to be a refractive element, a diffractive element, an internal refraction element, and/or a reflective element.
The inner optical element 102 is configured to cooperate with a virtual point light source 106 that is closer to both the inner optical element 102 and the outer optical element 100 . The inner optical element 102 is configured to redirect the incoming light rays 122 from the point light source 106 so that the exiting light rays 124 generally follow the same path as the light rays 126 emanating from the furthest virtual point light source 104 . By providing the additional inner optical element 102 the depth of the housing can be reduced due to the redirection of the light rays provided by the inner optical element 102 . Accordingly, LEDs can be provided inwardly (i.e. towards the optical elements 102 and 100 ) from the virtual point light source 106 in a similar manner to those described with reference to FIGS. 2 and 3 . The optical elements 100 and 102 can be disposed inside a housing (not shown) similar to the housings 28 and 68 described above.
FIG. 4B is similar to FIG. 4A and shows that the outer refractive optical element 100 and the inner optical element 102 can collectively function as a pair of converging lenses. More particularly, the inner optical element 102 collects most of the light from the point light source 104 and simulates a focal point to the outer refractive optical element 100 . The outer refractive optical element 100 generally comprises a complex pin optic that distributes the light from a point source to a given specification, wherein each and every pin has a unique shape. FIG. 4B includes a number of additional lines 128 showing the light being collimated while exiting the outer refractive optical element 100 . Accordingly, the beam pattern gets narrower after each lens, even while the “shell” (i.e., the outer refractive optical element 100 ) is distributing the light for a given specification.
FIG. 7 demonstrates control of the light to generate an asymmetric beam pattern. Outer surface 134 represents an outer surface of an optical element that is similar to outer surface 114 described with reference to FIG. 4 . Reference surface 131 is similar to inner surface 112 described with reference to FIG. 4 and inner surface 64 described with reference to FIG. 3 . Incoming light rays 132 are similar to light rays 124 described with reference to FIG. 4 . To create an asymmetric beam pattern, the inner surface 131 is replaced by the distribution surface 130 . The distribution surfaces 130 are oriented at the same angle as the reference inner surfaces which results in the outer surface 134 transmitting the same beam pattern against the central axis 108 . The inner distribution surface 130 of the lens, which is an optical element including the outer surface 134 and the inner distribution surface 130 , can be disposed in a pattern, e.g. a radial or linear (square or diamond) pattern. In certain instances it has been found desirable to move the beam axis 5° down the horizontal axis to provide the desired intensity for a signal lamp. In yet another embodiment, a total internal reflection element 200 for an LED signal is shown in FIG. 8 . Total internal reflection (TIR) is a phenomena where electromagnetic radiation (light) in a given medium (e.g., an acrylic or polycarbonite material) incident on the boundary with a less dense medium (e.g., air), at an angle equal to or larger than the critical angle, is completely reflected from the boundary. Commonly used in fiber optics technology and in binocular prisms, properly designed optical components using total internal reflection do not require expensive mirror/reflective coated surfaces to re-direct light. To achieve a materials savings in a TIR element, rather than a single large reflective face, a series of smaller consecutive TIR faces may be utilized. As the interface between the consecutive TIR faces creates an undesired light refraction, it is desirable that the interface between faces be as small (or sharp), as possible.
As shown in FIG. 8 , a plurality of curved entry faces 202 is aligned with a corresponding plurality of TIR faces 204 and exit faces 206 , which redirect light emitted from the base of the signal in a generally downward direction. The curved entry faces 202 have the optical effect of concentrating incident light onto a center of the corresponding TIR face 204 , thereby allowing light to impinge on the TIR faces 204 from a wider range of angles to be redirected for downward projection through the desired exit faces 206 . The TIR element 200 may be constructed with a stepped configuration on the exit faces 206 to minimize the space and materials required for the element 200 , among other things.
Each of the curved entry faces 202 is sloped in the direction of the next stepped level, which lowers light loss creating zones by decreasing the optical area dedicated to the radiuses between stepped levels of the entry faces 202 . The signal may be configured for retrofitting into existing incandescent signal housings.
FIG. 9 is a close-up view of a portion of the TIR element 200 of FIG. 8 . The light rays 210 incident upon the entry faces 202 are preferably parallel aligned with the lens axis whereby generally all of the light incident upon the entry face 202 converges and impacts the corresponding TIR face 204 . The light rays 212 exiting the exit faces 206 are thereby directed in a downward manner.
FIG. 10 shows an alternative TIR element 210 , which also has a plurality of curved entry faces 212 that are aligned with a corresponding plurality of TIR faces 214 and exit faces 216 , which redirect light emitted from the base of the signal in a generally downward direction. The curved entry faces 212 have the optical effect of concentrating incident light onto a center of the corresponding TIR face 214 , thereby allowing light to impinge on the TIR faces 214 from a wider range of angles to be redirected for downward projection through the desired exit faces 216 . The TIR element 210 may be constructed with a stepped configuration on the exit faces 216 . Each of the curved entry faces 212 is sloped in the direction of the next stepped level, which lowers light loss creating zones by decreasing the optical area dedicated to the radiuses between stepped levels of the entry faces 212 . In this embodiment, radiuses 218 are added at transition points between the steps of the TIR faces 214 and the exit faces 216 . It is to be understood that there is generally a radius on the edge of the stepped optical element due to the machining tool geometry or wearing of the mold. Machining the sharpest edge on a mold may reduce the uncontrolled light generated by the radius, but it may also generate performance variation over time due to wearing of the mold. A sharp edge also increases the fragility of the part at impact and vibration.
As shown in FIG. 10 , the light rays 220 incident upon the entry faces 212 are preferably parallel aligned with the lens axis whereby generally all of the light incident upon the entry face 212 converges and impacts the corresponding TIR face 214 . The light rays 222 exiting the exit faces 216 are thereby directed in a downward manner.
With reference now to FIG. 11 , in an alternative embodiment of the signal lamp, an optical axis 302 is an imaginary line between the center of an LED array 304 to the center of an outer lens (or shell) 306 . Note there is an angle 308 between the optical axis 302 and a geometrical axis 310 . The angle 308 between the geometrical axis 310 and the optical axis 302 depends on the center of light flux as determined by the specification. For example, in the case of the ITE (Institute of Transportation Engineers) specification, the center of flux is around 5 degrees down the horizon. So the optical axis 302 would be approximately 5 degrees lower than the geometrical axis 310 pointing to the horizon. The geometrical axis 310 is an imaginary line crossing perpendicular to the center of an installation rim (or housing) 312 . FIG. 11 also shows an optional inner lens 314 that is symmetrical with respect to the optical axis 302 , but it can be asymmetrical as well. It is to be appreciated that the features shown in FIG. 11 may be applied to the previously described embodiments of the signal lamp.
The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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A lighting device includes a housing having an open end and a geometrical axis and at least one light source disposed along an optical axis. The lighting device further includes an outer optical element having a focal point and closing the open end of the housing, the optical element comprising a converging outer surface and a diverging inner surface that cooperates with the light coming from the inner optical element. Additionally, the lighting device includes an inner optical element between the light source and the outer optical element, the inner optical element redirecting light from a light source that is offset from the focal point toward the outer optical element.
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BACKGROUND OF THE INVENTION
The present invention relates to a new and improved jet spinning device comprising a pneumatic twist jet or nozzle arranged downstream from a delivery roller pair for receiving an unspun yarn delivered by the delivery roller pair together with an output roller pair arranged downstream from the twist jet for receiving the spun yarn delivered by the twist jet.
When using the jet spinning method, and thus during the use of a jet spinning device, high spinning speeds are achieved, that is there are attained fiber travel speeds up to 200 m/min. This implies that, on the one hand, the delivery roller pair feeds the unspun yarn at the aforementioned speed into the twist jet which, on the other hand, passes on the spun yarn at substantially the same speed.
From German Published Patent No. 2,722,319 there is known a jet spinning device (referred to in this patent as "device for pneumatic false twist spinning") in which a yarn can be spun with the aforementioned speed.
As in other spinning methods, the yarn also occasionally breaks when using the jet spinning method. Such yarn rupture is detected by an automatic monitoring system which does not form part of this invention, and as a result the fiber sliver feed is interrupted by the same automatic system.
Having regard to these facts, the device disclosed in the aforementioned German Published Patent No. 2,722,319 and similar devices have the disadvantage that an automatic system for dealing with and eliminating such a yarn or thread break only can be provided in a very poor form or with considerable complications and therefore expense. This is the case because the yarn delivered at a high speed from the twist jet must be taken-up by a movable suction element at the exit opening or mouth of the twist jet and must be guided between output rollers, which are automatically separable and reclosable and are arranged at a spacing corresponding to the spinning process, the yarn thereafter being transferred to a wind-up device. This disadvantage also applies, even if to a lesser extent, to the same procedure when carried out manually.
SUMMARY OF THE INVENTION
It is therefore a primary object of this invention to eliminate this disadvantage.
Another important object of the present invention is directed to an improved construction of jet spinning device which facilitates the self-threading of the yarn into the pair of output rollers.
Yet a further important object of the present invention is directed to a new and improved construction of jet spinning device which renders easier the handling of yarn breakage.
A further noteworthy object of the present invention is concerned with a jet spinning device which is structured such that there is afforded quieter operation, while facilitating the threading of the yarn into a pair of output rollers arranged in spaced relationship from and downstream of the twist jet or nozzle.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the jet spinning device of the present development is manifested by the features that a pneumatic guide tube communicates with the twist jet or nozzle and projects so close to the output roller pair that the yarn is forwarded into the converging space of the output roller pair, and thus, is automatically received and forwarded by the output roller pair.
Some of the more notable advantages of the invention are to be seen in that, on the one hand, the self-threading of the yarn into the output roller pair is achieved in the simplest manner and, on the other hand, in the event that an automatic system is provided for dealing with yarn or thread breaks only the simple transfer of the yarn from the output rollers or rolls to the wind-up device must be automated.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various embodiments depicted in the drawings there have been generally used the same reference characters to denote the same or analogous elements, and wherein:
FIG. 1 shows a schematic representation of a jet spinning device in combination with a preceding or upstream located two-zone drafting arrangement or mechanism, the combination making up a so-called "downward spinning system";
FIG. 2 shows the combination of FIG. 1, but this time illustrated as a so-called "upward spinning system";
FIG. 3 shows the jet spinning device of FIG. 1 or FIG. 2 on an enlarged scale and part-schematically illustrated;
FIGS. 4 to 9 show respective details of the jet spinning device of FIG. 3, but each showing a respective different embodiment, represented to the same scale; and
FIG. 10 shows the combination of FIG. 1, but arranged as a so-called "horizontal spinning system".
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the jet spinning device has been shown in the drawings as needed for those skilled in the art to readily understand the underlying principles and concepts of the present development, while simplifying the illustration of the drawings. Turning attention now specifically to the jet spinning devices 1 shown in FIGS. 1 and 2, each such jet spinning device 1 will be seen to comprise a pneumatic twist jet or nozzle 3 arranged following a delivery roller pair 2 and with an immediately thereat flow communicating pneumatic guide tube or pipe 4 which opens towards an output or exit roller pair 5.
The term "pneumatic guide tube", as employed herein, refers to a tube or the like which guides an air stream or flow under normal aerodynamic conditions, that is to say, without sudden changes in cross-section and with a roughness normal for pneumatic guide tubes for fibers.
The jet spinning device 1 is arranged downstream from a suitable drafting arrangement or mechanism 6 which does not form part of the invention and which comprises the delivery roller pair 2. This drafting mechanism 6 also comprises an intermediate roller pair 7 provided with guide aprons 7.1 and 7.2, an infeed roller pair 8 provided with a first fiber sliver condensor 10 arranged before or upstream of the infeed roller pair 8, and a second fiber sliver condensor 9 arranged between the intermediate roller pair 7 and the infeed roller pair 8. The drafting mechanism 6 takes-up a fiber sliver 11 or the like which passes into the drafting mechanism 6 in the direction of the not particularly referenced arrow and which is drawn or drafted into a still unspun yarn which is delivered by the delivery roller pair 2 and automatically received and forwarded by the pneumatic twist jet or nozzle 3. The term fiber sliver 11 as used herein is intended to encompass a sliver from a drawing frame or roving from a roving frame or a plurality of combined rovings.
In the twist jet 3, this unspun yarn is spun to a finished yarn 12 received and forwarded by output roller pair 5. The yarn 12 leaves the output roller pair 5 in the direction of the not particularly referenced arrow and is thereafter taken-up by a conventional wind-up device (not shown).
Instead of the illustrated drafting mechanism 6 another drafting mechanism or arrangement can be used which is capable of delivering an unspun yarn with the same speed.
The twist jet 3 is basically known from the aforementioned German Published Patent No. 2,722,319, to which reference may be readily had and the disclosure of which is incorporated herein by reference. This twist jet 3 is additionally provided with a substantially cylindrical surface 14 and an abutment or stop 15 for receiving a sleeve or collar 13 provided on the pneumatic guide tube 4. Mounting of the pneumatic guide tube 4 on the twist jet or nozzle 3 then can be conveniently effected by a clamping ring or equivalent structure (not shown) encircling both parts. As a variation, in place of the cylindrical surface 14, a screw thread (not shown) can be provided for mounting the pneumatic guide tube 4 on the twist jet 3. This mounting is not, as such, essential to the invention and any suitable mounting arrangement can be employed.
The pneumatic guide tube 4 has an internal wall 16 which at the connection or interface 17 with the exit or outlet channel C of the twist jet or nozzle 3 has the same diameter as such exit or outlet channel C.
Instead of being composed of two parts, the twist jet 3 and the pneumatic guide tube 4 can be made in one piece or the pneumatic guide tube 4 can be made up of a plurality of parts.
The exit or outlet opening 18 of the pneumatic guide tube 4 projects so close to the output or exit roller pair 5 that the yarn 12 is forwarded into the converging space 19 of the output roller pair 5 and is thus entrained by the latter.
The sum of all spacing gaps or spaces between the rim or mouth edge 20 of the exit or outlet opening 18 and the cylindrical surface of the output roller pair 5, defining an air exit or outlet cross-section between this rim 20 and said cylindrical surface, must not be substantially smaller than the opening or mouth cross-section measured normal to the direction of flow and as will be more fully defined later in this disclosure. This condition applies to all modifications still to be described.
In order to achieve a substantially uniform air exit or outlet cross-section the exit or outlet opening 18 is formed in a manner adapted to the cylindrical surface of the output or exit roller pair 5, as shown in FIGS. 4, 6, 7 and 8, as variants 18.1, 18.3, 18.4 and 18.5 projecting partly into the converging space or region 19.
In FIGS. 5 to 9 the variants 18.2, 18.3, 18.4 and 18.5 respectively also show how the exit or outlet opening 18 is arranged relative to an exit or output roller pair 5 disposed at an inclination to the direction of flow.
In these variants, the rim 20 of the arrangement of FIG. 3 is changed in FIG. 4 to the rim 20.1, in FIG. 5 to the rim 20.2, in FIG. 6 to the rim 20.3, in FIG. 7 to the rim 20.4, in FIG. 8 to the rim 20.5, and in FIG. 9 to the rim 20.6.
The arrangement of the pneumatic guide tube 4 must be such that its axis of symmetry (not shown) coincides with the yarn or thread path in the region of the exit or outlet opening.
The rims 20 to 20.6 define those surfaces which face the two cylindrical surfaces of the output or exit roller pair 5 and are formed by the periphery of the exit our outlet opening.
In relation to each variant, the term "air exit or outlet cross-section" refers to the respective surface or area which is constituted by the sum of all the shortest distances between the rim and the oppositely situated cylindrical surfaces of the output roller pair 5.
In FIGS. 3 and 5 the exit or outlet opening 18 or 18.2 is so arranged that the rim 20 or 20.2, respectively, lies in a plane which is substantially parallel to an imaginary plane containing the axes of the output or exit rollers 5.
FIGS. 7 to 9 also show respective outlet or exit openings 18.4, 18.5 and 18.6 with a flow diversion directed towards the output or exit roller pair 5.
In FIG. 7, the outlet opening 18.4 has an elbow or curved portion 21, in FIG. 8 the outlet opening 18.5 has a divertor portion 22, and in FIG. 9 the outlet opening 18.6 has a divertor portion 23. The elbow portion 21 and the divertor parts or portions 22 and 23 assist the diversion of the air flow and of the yarn during threading into the converging space or region 19.
The elbow portion 21 is formed by bending of the pneumatic guide tube 4 in the opening or mouth region shown in FIG. 7. The divertor parts or portions 22 and 23 are constituted by substantially flat sheet parts which, as shown in FIGS. 8 and 9 respectively, are secured at respective angles of inclination α and β to a surface milled or otherwise appropriately machined in the opening region of the outlet or exit opening 18.5 and 18.6, respectively.
The degree of bend or curvature of the elbow or curved portion 21 and the values of the angles of inclination α and β, respectively, depend upon the inclination of the output or exit roller pair 5 with respect to the pneumatic guide tube 4 and upon the speed of the air flow, and they are determined empirically in practice.
FIG. 9 shows another arrangement which influences the direction of flow and in which the spacing between the lowest part of the rim 20.6 and the output roller pair 5, that is to say, the spacing in relation to the lower roller 5.1, is smallest and increasingly widens towards the upper region of the rim 20.6. By this arrangement, the air exit or outlet in the lowest region of the rim 20.6 can be arranged such that the yarn 12 with certainty is not transported over the rim 20.6 past the lower output roller 5.1 into the free space or ambient surroundings, but is forwarded or transported into the converging space or region 19.
The quantity of air flowing through the pneumatic guide tube 4 corresponds to the quantity of air delivered by the twist jet or nozzle 3.
At the start of the spinning process, that is during suction of the unspun yarn by the twist jet or nozzle 3 and the subsequent spinning and further transport by means of the air quantity required by the twist jet 3, the free end of the yarn 12 is guided by the pneumatic guide tube 4 towards and into the converging space 19, so that it is caught by the output roller pair 5.
For reasons of flow technology, the pneumatic guide tube 4 can be provided with a cone (not shown) widening towards the output roller pair 5. This cone can have the same apex or aperture angle (not shown) over the whole length of the pneumatic guide tube. Even if the pneumatic guide tube does not have a cone over its complete length, the apex or aperture angle should still not substantially exceed the apex or aperture angle of the outlet or exit channel C.
The aforementioned term "opening or mouth cross-section" refers to that internal cross-section of the pneumatic guide tube 4 which is still present as a complete section in the opening region of the pneumatic guide tube. In FIG. 3 this is, for example, the cross-section of the outlet or exit opening 18 itself, while in the other figures it is that complete section which immediately follows the inclined or beveled opening 18.2 (FIG. 5), or the profiled opening 18.1, 18.3, 18.4, 18.5 or 18.6, respectively, (FIGS. 4 and 6 to 9).
An advantage of this construction of the pneumatic guide tube (which is favorable for flow technological grounds) lies in the possibility of damping the noise which arises upon departure of the air.
FIG. 2 shows that the jet spinning device can also be used with the spinning direction upwardly arranged. The elements in this variant construction are therefore generally indicated with the same reference numerals as used for the embodiment of FIG. 1.
FIG. 10 shows that the jet spinning device can also be used with the spinning direction substantially horizontally arranged. The elements in this variant construction are therefore generally indicated with the same reference numerals as used for the embodiment of FIG. 1.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,
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In a jet spinning device, in order to enable automatic transport of the yarn from a twist jet to an output roller pair which, for spin-technological reasons, is somewhat spaced from the twist jet, the twist jet is placed in flow communication with a pneumatic guide tube projecting up to the output roller pair. In order to enable automatic threading of the yarn or the like into the output roller pair, the opening or mouth of the guide tube is arranged so close to the output roller pair that the yarn is conveyed into the converging space of the output roller pair and is engaged or entrained thereby.
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FIELD OF THE INVENTION
[0001] The invention is generally related to apparatus for engaging a fitting. More particularly, the invention relates to wrench-likes tools for engaging a locknut such as employed with electrical connectors.
BACKGROUND OF THE INVENTION
[0002] Locknuts are typically screwed against the end of a pipe fitting or other conduit to hold the latter securely so as to provide an electrical ground. They commonly take the form of a collar having internal threads and may be constructed of various materials (e.g., metal, plastic) and come in a variety of shapes (e.g., hexagonal, square, round) and sizes.
[0003] One common application of locknuts is the securing of sections of electrical connectors within electrical junction boxes. A junction box thereby serves to join different runs of raceway or cable and provides space for the connection and branching of the enclosed conductors.
[0004] Locknuts used in association with electrical conduit are typically annular metal rings. The locknut includes a threaded inner surface for engaging a complementary threaded outer surface on the electrical connector. A series of projections known as lugs, commonly six or eight, extend radially from the ring. Between the lugs are rounded openings or scallops.
[0005] Conventional methods of tightening and loosening or removing locknuts include placing a screwdriver or similar device against one of the lugs and hitting the screwdriver with a hammer. This method, while effective, does not guarantee a tight fitting and has some inherent safety concerns.
[0006] One tool for engaging a locknut is disclosed in U.S. Pat. No. 2,522,038, issued to Houghton. Houghten discloses a wrench having a cage connected to a shank with a suitable handle thereon. An annular member is secured to the cage. A plurality of lug extensions extend therefore in spanner wrench fashion. The position of the extensions is such that they fit into the spaces between a pair of lugs of the locknut.
[0007] U.S. Pat. No. 2,575,779, issued to Young, discloses an electrician's wrench and reamer having a tool head which includes a pair of spaced prongs that are set apart so as to readily straddle a nut and fit the scallops. Each prong is configured to fit between a pair of adjacent lugs.
[0008] U.S. Pat. No. 5,524,511, issued to Taka's, discloses a locknut tool having a C-shaped handle. The handle includes a pair of shoulders that engage a lug when the wrench is fitted over a locknut. The position of the shoulders is such that they fit into the spaces between a pair of lugs of the locknut.
[0009] Because they result in only a limited amount of torque, these prior art tools are limited in their ability to tighten or remove a locknut. The need exists for a simple, efficient tool for tightening and removing locknuts.
SUMMARY OF THE INVENTION
[0010] One aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a base and a plurality of upstanding axially projecting tangs extending from the base for alternatively engaging opposing sides of the laterally-extending projection.
[0011] In one embodiment, the base is carried by a wrench. The base can be configured for releasable attachment to a socket wrench. The socket wrench can permit the apparatus to engage the nut in a ratcheting fashion.
[0012] Another aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a handle and a head carried by the handle and having a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection.
[0013] According to yet another aspect of the invention, a second head is carried by the handle and has a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection. The first and second heads may be of the same or of different size and configuration. Further, the first and second heads may have the same or different number of upstanding axially projecting tangs.
DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective view of an electrical junction box.
[0015] [0015]FIG. 2 is a perspective view of a locknut commonly used with electrical connectors.
[0016] [0016]FIG. 3 is a perspective view of a tool embodying features of the invention.
[0017] [0017]FIG. 4 is a top view of the tool shown in FIG. 3.
[0018] [0018]FIG. 5 is a side view of the tool shown in FIG. 3.
[0019] [0019]FIG. 6 is a perspective view of an alternative embodiment of a tool embodying features of the invention.
[0020] [0020]FIG. 7 is a top view of an alternative embodiment of a tool embodying features of the invention.
[0021] [0021]FIG. 8 is a top view of an alternative embodiment of a tool embodying features of the invention.
[0022] [0022]FIG. 9 is a perspective view illustrating use of the tool shown in FIG. 8 to engage a locknut on a connector within an electrical junction box.
[0023] [0023]FIG. 10 is a perspective view of an alternative embodiment of a tool embodying features of the invention.
[0024] [0024]FIG. 11 is a top view of the tool shown in FIG. 10.
[0025] [0025]FIG. 12 is a side view of the tool shown in FIG. 10.
[0026] [0026]FIG. 13 is a perspective view illustrating use of the tool shown in FIG. 12 to engage a locknut on a connector within an electrical junction box.
DETAILED DESCRIPTION
[0027] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
[0028] I. Tool for Engaging a Locknut
[0029] [0029]FIG. 1 shows a conventional electrical junction box 10 having a bottom wall 12 and four side walls 14 . The box 10 includes a series of scored knock-out sections 16 that are well known in the art. Removal of a knock-out 16 , e.g., by striking the section with a hammer, results in an opening 18 that permits passage of an electrical connector 20 . The number, placement, and configuration of the knock-outs may be varied to accommodate specific needs.
[0030] Conventional connectors 20 include a threaded end region 22 sized and configured for passage through the opening 18 . Connectors 20 are available in a variety of sizes, e.g., ½ inch diameter, 1 inch diameter.
[0031] The connector 20 is typically secured within the junction box 10 by a locknut 24 . As seen in FIG. 2, a conventional locknut 24 used for electrical connectors 20 is typically an annular metal ring 26 having a threaded inner surface 28 sized and, configured to mate with the threaded end region 22 of the connector 20 within the junction box 10 . Extending from the outer periphery of the ring 26 is a series of projections, or lugs 30 . The areas between adjacent lugs 30 define a series of rounded openings, or scallops 32 . Locknuts 24 employed with electrical connectors 20 typically have either six lugs 30 (as FIG. 2 illustrates) or eight lugs 30 (not shown) and come in a range of various sizes to accommodate the various sizes of connectors 20 , e.g., ½ inch diameter, 1 inch diameter, etc.
[0032] It is often difficult to position a pliers or other tool so as to engage the lugs 30 of a locknut 24 sufficiently to tighten or loosen the locknut 24 . This is particularly the case in instances in which it is necessary to secure a connector 20 in an opening 18 that is located in a corner of the box 10 , as shown in FIG. 1.
[0033] [0033]FIG. 3 shows a wrench tool 34 for engaging a locknut 24 . The tool 34 is particularly well suited for engaging a locknut 24 such as that used to secure an electrical connector 20 , and thus will be described in accordance with such use. However, uses of the tool 34 to engage and secure other fittings are contemplated and will be apparent to those skilled in the art that read this disclosure.
[0034] The tool 34 comprises a handle 36 carrying at least one head 38 A or 38 B. If a preferred embodiment, as seen in FIG. 3, the tool 34 has a first head 38 A and a second head 38 B extending from opposing ends of the handle 36 . The heads 38 A and 38 B are annular rings 39 sized and configured to have an inner diameter slightly larger than the outer diameter of the ring 26 of a complementary locknut 24 . As FIGS. 3 - 5 show, the first and second heads 38 A and 38 B may be of different diameters, e.g., the first ring 39 A may be of a ½ inch diameter and second ring 39 B may by of a 1 inch diameter. It is contemplated, however, that the head 38 A or 38 B may take forms other than a ring 39 , e.g., C-shape crescent wrench configuration or hexagonal (not shown). In one alternative embodiment, shown in FIG. 6, the ring 39 includes an opening or notch 40 . The notch 40 permits electrical wires to pass through the head 38 A or 38 B. It is to be understood that the first and second heads 38 A and 38 B may be of the same of different configurations, e.g., first head 38 A is of a ring configuration and second head 38 B is of a hexagonal configuration.
[0035] Extending from the ring is a series of projections or tangs 42 . The tangs 42 can be arranged in pairs and configured to rest in adjacent scallops 32 to engage opposing sides of a lug 30 . In this arrangement, movement of the head 38 A or 38 B in a first direction (e.g., clockwise) applies force to one side of the lug 30 to move the locknut 24 in a first direction (e.g., tightens the locknut 24 ). Movement of the head 38 A or 38 B in the reverse direction (e.g., counterclockwise) applies force to the opposite side of the same lug 30 to move the locknut 24 in a second direction (e.g., loosens the locknut 24 ). Desirably, there is at least two pair of tangs 42 . The pairs can be variously spaced from one another to accommodate locknuts 24 having varying number of lugs 30 . In the embodiment illustrated in FIGS. 3 - 5 , the pairs are spaced 180° apart, thereby accommodating a locknut 24 having either six or eight lugs 30 .
[0036] In an alternative embodiment, tangs 42 extend circumferentially around the heads 38 A and 38 B, thereby providing a greater amount of torque. The number and configuration of the tangs 42 can be varied to accommodate varying number of lugs 30 . For example, FIG. 7 illustrates an embodiment in which the first head 38 A includes six tangs 42 configured to engage a locknut 24 having six lugs 30 and the second head 38 B includes eight tangs 42 configured to engage a locknut 24 having eight lugs 30 .
[0037] As previously noted, the first and second heads 38 A and 38 B may be of the same diameter or size or of different diameters or sizes. FIG. 8 illustrates an arrangement in which the first and second heads 38 A and 38 B both include six tangs 42 , but the first head 38 A is of one diameter (e.g., ½ inch) and the second head 38 B is of a different diameter (e.g., 1 inch). It is to be understood that by varying the size and configuration of the heads 38 A and 38 B and the number of tangs 42 , the tool 34 can be customized to accommodate virtually any locknut 24 .
[0038] The tool 34 may be made of steel, a combination of steel and plastic, or other suitable materials and formed by mold, die, or machining.
[0039] In use, a connector 20 is placed within an opening 18 in a junction box 10 . A locknut 24 is placed on the threaded end region 22 of the connector 20 . As illustrated in FIG. 9, a tool 34 having a head 38 A or 38 B that is complementary to the locknut 24 (i.e., in diameter of the head 38 A or 38 B and number of tangs 42 ) is then positioned to engage the locknut 24 . The handle 36 is then manipulated to rotate the locknut 24 in a first direction (e.g., clockwise) to tighten the locknut 24 . The locknut 24 may then be rotated in the opposite direction (e.g., counterclockwise) to loosen and remove the locknut 24 .
[0040] II. Alternative Embodiment
[0041] FIGS. 10 - 12 illustrate a socket tool 46 embodying features of the invention. Similar to the embodiment of FIGS. 3 - 5 , the socket 46 may be variously sized and configured and includes a plurality of tangs 42 configured to rest in adjacent scallops 32 to engage opposing sides of a lug 30 . The socket 46 is sized and configured to couple to a conventional socket wrench 48 , as shown in FIG. 13. The tool 46 may be made of steel or other suitable materials and formed by mold, die, or machining.
[0042] This arrangement permits the socket tool 46 to be rotated in a ratcheting fashion. The ratchet motion is particularly desirable in a junction box, where space for manipulating a wrench handle is limited.
[0043] With continued reference to FIG. 13, the connector 20 is placed within an opening 18 of the junction box 10 and a locknut 24 is placed on the connector 20 , as previously described. A socket tool 46 that is sized and configured complementary to the locknut 24 is coupled to the socket wrench 48 . It is to be understood that by varying the size of the configuration of the socket 46 , as well as the number and position of tangs 42 , the tool 46 can be customized to accommodate virtually any locknut 24 . The tool 46 is then placed over the locknut 24 with the tangs 42 positioned to engage the locknut 24 . The wrench 48 is then manipulated to rotate the locknut 24 to tighten or loosen the locknut 24 , as also previously described.
[0044] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
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A tool for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a base and a plurality of upstanding axially projecting tangs extending from the base for alternatively engaging opposing sides of the laterally-extending projection.
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RELATED APPLICATION
[0001] This Application is a Continuation of U.S. application Ser. No. 13/548,342, titled “MULTIPLE STEP PROGRAMMING IN A MEMORY DEVICE,” filed Jul. 13, 2012, (Allowed) which is commonly assigned and incorporated herein by reference.
TECHNICAL FIELD
[0002] The present embodiments relate generally to memory and a particular embodiment relates to multiple step programming in a memory device.
BACKGROUND
[0003] Memory is typically provided as an integrated circuit(s) formed in and/or on semiconductor die(s), whether alone or in combination with another integrated circuit(s), and is commonly found in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), and flash memory.
[0004] Flash memories have developed into a popular source of non-volatile memory for a wide range of electronic applications. Flash memories typically use a one-transistor memory cell that allows for high memory densities, high reliability, and low power consumption. Changes in threshold voltage of the cells, through programming of a charge storage structure, such as floating gates or trapping layers or other physical phenomena, determine the data state of each cell. Common uses for flash memory include personal computers, digital cameras, digital media players, digital recorders, games, appliances, vehicles, wireless devices, cellular telephones, and removable memory modules.
[0005] Single level memory cells (SLC) can store a single bit of data. Multi-level memory cells (MLC) can store two or more bits of data.
[0006] One problem that can occur with programming MLC memory is floating gate-to-floating gate capacitive coupling. The coupling can result in one memory cell disturbing adjacent memory cells, thus causing erroneous data to be stored in the adjacent memory cells.
[0007] Multiple step programming algorithms have been used to reduce the floating gate-to-floating gate coupling while also improving threshold voltage distribution widths. One particular multiple step programming operation comprises a prior art touch-up programming operation. This type of programming comprises programming an even page of memory first, reading the even page of memory, programming an odd page of memory then “touching-up” the even page of memory with additional programming pulses. FIGS. 1A-1C illustrate plots of threshold voltage distributions that can result from using a typical prior art multiple step programming operation.
[0008] FIG. 1A illustrates threshold voltage distributions after an even page of memory has been programmed. This figure shows an erased state (111) as well as seven programmed states (000-011).
[0009] The states of FIG. 1A are each represented by three bits that are the programmed “hard” data of a multiple bit programmed word. The hard data are the actual data, of the multiple bit programmed word, that are used. The programmed word can also comprise “soft” data that are used to indicate a more precise location of the programmed state. For example, the area between each distribution that is indicated by the arrows is the soft data portion of the programmed word that indicates a location of its associated state to the right of the arrow. The soft data might be four bits of the multi-bit programmed word. Thus, the soft data can be considered the least significant bits (LSB) of the programmed word while the hard data can be considered the most significant bits (MSB) of the programmed word.
[0010] An even page read operation is performed after the even page has been programmed. Since programming of the memory pages might not be sequential, data stored in a page buffer for programming might be overwritten, after programming, by subsequent data to be programmed to the memory. Thus, during the even page read operation, the even page is read back out into the page buffer so that it can be further programmed during a subsequent touch-up programming operation, as discussed subsequently. This even page read can introduce errors into the programming operation, as subsequently described.
[0011] After the even page read is performed, the odd page of the memory cells is programmed. FIG. 1B illustrates the threshold voltage distributions after the odd page of memory has been programmed. The distributions have widened out due to the disturb effects of both program disturb (e.g., multiple programming voltages on the same word line) as well as floating gate-to-floating gate coupling.
[0012] It can be seen in FIG. 1B that the overlapping states have the potential to cause errors during reading of the memory since it could be unclear whether the read data belonged in, for example, the 001 state or the adjacent 101 state. In order to tighten up the distributions, an even page touch-up programming operation is performed.
[0013] The typical prior art even page touch-up programming operation comprises performing an additional program operation comprising additional programming pulses in order to program in the even page data read during the previous even page read operation. The even page touch-up programming operation programs the memory cells at the lower ends of the distributions to a high threshold voltage such that the memory cells at the lower ends of the distributions are moved up, thus tightening the distributions. FIG. 1C illustrates the distributions after the touch-up programming operation.
[0014] A problem with the above-described typical prior art multiple step programming operation is that, since the even page read operation does not use error correction coding, read errors are passed through uncorrected. This uncorrected data is then used during the touch-up programming operation. If the uncorrected data contains errors, the data is re-programmed with the errors during the touch-up operation. This can result in misplacement errors as shown in FIG. 1C by the “tails” 101 - 107 that are part of each distribution. These tails overlap with an adjacent distribution and represent the hard errors (e.g., error bits that are assigned a low probability of error by an error correction code (ECC) engine) transformed from the original soft errors (e.g., error bits that are assigned a high probability of error by the ECC engine) that can occur when assigning data to the wrong distribution during a read subsequent to the touch-up operation.
[0015] For the reasons stated above and for other reasons that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art to reduce these programming errors caused by misplacement of data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A-1C show plots of threshold voltage distributions resulting from typical prior art multiple step programming.
[0017] FIG. 2 shows a schematic diagram of one embodiment of a portion of a memory array.
[0018] FIG. 3 shows a flow chart of one embodiment of a method for programming memory using a modified touch-up operation.
[0019] FIGS. 4A-4C show plots of threshold voltage distributions in accordance with the method for programming of FIG. 3 .
[0020] FIG. 5 shows a shows a block diagram of one embodiment of a system that can incorporate the multiple step programming method using the modified touch-up operation.
DETAILED DESCRIPTION
[0021] In the following detailed description, reference is made to the accompanying drawings that form a part hereof and in which is shown, by way of illustration, specific embodiments. In the drawings, like numerals describe substantially similar components throughout the several views. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense.
[0022] FIG. 2 illustrates a schematic diagram of one embodiment of a portion of a NAND architecture memory array 201 comprising series strings of non-volatile memory cells. The present embodiments of the memory array are not limited to the illustrated NAND architecture. Alternate embodiments can use NOR, AND, PCM, or other architectures.
[0023] The memory array 201 comprises an array of non-volatile memory cells (e.g., floating gate) arranged in columns such as series strings 204 , 205 . Each of the cells is coupled drain to source in each series string 204 , 205 . An access line (e.g., word line) WL 0 -WL 31 that spans across multiple series strings 204 , 205 is coupled to the control gates of each memory cell in a row in order to bias the control gates of the memory cells in the row. Data lines, such as even/odd bit lines BL_E, BL_O, are coupled to the series strings and eventually coupled to sense circuitry that detects the state of each cell by sensing current or voltage on a selected bit line.
[0024] Each series string 204 , 205 of memory cells is coupled to a source line 206 by a source select gate 216 , 217 (e.g., transistor) and to an individual bit line BL_E, BL_O by a drain select gate 212 , 213 (e.g., transistor). The source select gates 216 , 217 are controlled by a source select gate control line SG(S) 218 coupled to their control gates. The drain select gates 212 , 213 are controlled by a drain select gate control line SG(D) 214 .
[0025] In a typical prior art programming of the memory array, each memory cell is individually programmed as either a single level cell (SLC) or a multiple level cell (MLC). The prior art uses a cell's threshold voltage (V t ) as an indication of the data stored in the cell. For example, in an SLC, a V t of 2.5V might indicate a programmed cell (e.g., logical “0” state) while a V t of −0.5V might indicate an erased cell (e.g., logical “1” state). An MLC uses multiple V t ranges that each indicates a different state. Multiple level cells can take advantage of the analog nature of a traditional flash cell by assigning a specific bit pattern (e.g., 000-110) to a specific V t range.
[0026] FIG. 3 illustrates a flow chart of one embodiment of a method for programming memory using a modified touch-up operation. The even page of a group of memory cells is programmed 301 from data in a page buffer. For example, the group of memory cells might comprise a block memory of memory cells.
[0027] The programming can be accomplished by a series of programming pulses applied to a word line coupled to control gates of the memory cells being programmed. A program verify operation after each programming pulse determines whether the memory cell has been programmed to its desired threshold voltage as dictated by the respective data to be programmed. When the memory cell turns on in response to a read voltage on the respective word line and produces a current or voltage on a respective bit line, as detected by the sense circuitry, the memory cell has been programmed.
[0028] FIG. 4A illustrates the threshold voltage distributions that can result from the even page programming. The x-axis of the plot is the threshold voltage V t and the y-axis is the number of memory cells at each threshold voltage. The distributions are the result of the fact that memory cells program at different rates. Thus, one programming pulse might move a first memory cell to the middle of the “011” state while another memory cell might only move to the left side of the “011” state after the same programming pulse.
[0029] While a large number of the memory cells end up being programmed to within the distributions, some of the memory cells end up in uncertain areas 401 - 407 . When this uncertain data is read, ECC correction is not used when it is later re-programmed. For example, if uncertain data is read from the uncertain area 403 between the threshold voltage distributions for states “001” and “101”, they can be either one of the states, thus possibly resulting in the previously described misplacement errors if the data is read and later programmed as the wrong state.
[0030] Since the memory pages are not always programmed sequentially, the programmed even page or pages are read back out 303 to the page buffer. As subsequently described, this data is used later during a touch-up operation. During the reading of the page of data subsequent to the touch-up operation, an ECC engine checks the data for errors and attempts to perform corrections on the errors.
[0031] In order to reduce the hard errors caused by the touch-up operation passing through the read data “as-is” without ECC correction, the uncertain data is excluded, inhibited, or removed from the page buffer 305 . Thus, the uncertain data is left in the uncertain areas 401 - 407 between the distributions and are not further programmed during the subsequent touch-up operation.
[0032] The odd memory page or pages are then programmed 307 . This can be accomplished in a substantially similar manner to the even page or pages programming in that the data are programmed to their respective memory cells from the page buffer by increasing the threshold voltages of the respective memory cells to the respective threshold voltage of each desired state.
[0033] FIG. 4B illustrates the threshold voltage distributions after the odd page or pages being programmed. It can be seen that the disturb caused by the additional programming and floating gate-to-floating gate coupling of the memory cells has widened the distributions such that they overlap. In order to tighten up the distributions, a touch-up programming operation is performed 309 .
[0034] The touch-up programming operation comprises programming the data from the page buffer, that was previously read from the even page or pages, back to the memory cells. In one embodiment, the data is programmed back a certain voltage (e.g., 400 mV) higher. This has the effect of moving the lower ends of the distributions to higher threshold voltages and tightening the distributions.
[0035] The uncertain data from the uncertain locations 401 - 407 of FIG. 4A were not moved thus resulting in “tails” 410 - 416 on the distributions representing the uncertain data. However, these uncertain data are now “soft” errors (e.g., the least significant bits) instead of the “hard” errors (e.g., most significant bits) that resulted from the prior art touch-up programming operation.
[0036] The previous description, for purposes of illustration, started with programming the even page of data prior to programming the odd page of data. An alternate embodiment can comprise programming the odd page first, reading the odd page, programming the even page, then reprogramming the odd page.
[0037] FIG. 5 illustrates a functional block diagram of a memory device 500 as part of a memory system 520 . The memory device 500 is coupled to a controller 510 . The controller 510 may be a microprocessor or some other type of controlling circuitry. The memory device 500 has been simplified to focus on features of the memory that are helpful in understanding the present invention.
[0038] The memory device 500 includes an array 530 of non-volatile memory cells, such as the one illustrated previously in FIG. 2 . The memory array 530 is arranged in banks of word line rows and bit line columns. In one embodiment, the columns of the memory array 530 are comprised of series strings of memory cells as illustrated in FIG. 2 . As is well known in the art, the connections of the cells to the bit lines determines whether the array is a NAND architecture, an AND architecture, a NOR architecture, or another architecture.
[0039] Address buffer circuitry 540 is provided to latch address signals received through I/O circuitry 560 . Address signals are received and decoded by a row decoder 544 and a column decoder 546 to access the memory array 530 . It will be appreciated by those skilled in the art, with the benefit of the present description, that the number of address input connections depends on the density and architecture of the memory array 530 . That is, the number of addresses increases with both increased memory cell counts and increased bank and block counts. The page buffer 573 , as previously described, is coupled to the memory array for storing data to be programmed or that has been read.
[0040] The memory device 500 reads data in the memory array 530 by sensing voltage or current changes in the memory array columns using sense circuitry 550 . The sense circuitry 550 , in one embodiment, is coupled to read and latch a row of data from the memory array 530 . The I/O circuitry 560 provides bidirectional data communication as well as address communication over a plurality of data connections 562 with the controller 510 . Write circuitry 555 is provided to write data to the memory array.
[0041] Memory control circuitry 570 decodes signals provided on control connections 572 from the controller 510 . These signals are used to control the operations on the memory array 530 , including data read, data write (program), and erase operations. The memory control circuitry 570 may be a state machine, a sequencer, or some other type of control circuitry to generate the memory control signals. In one embodiment, the memory control circuitry 570 is configured to execute the method for programming with the modified touch-up programming operation.
[0042] The flash memory device illustrated in FIG. 5 has been simplified to facilitate a basic understanding of the features of the memory. A more detailed understanding of internal circuitry and functions of flash memories are known to those skilled in the art.
CONCLUSION
[0043] In summary, one or more embodiments include an improved multiple step programming method that reduces the chances of “hard” errors caused by an ECC engine assigning uncertain data to the wrong state. This can be accomplished by excluding the uncertain data from reprogramming during the touch-up operation.
[0044] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the invention.
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Method of operating a memory include programming a memory cell and reading the memory cell to determine a programmed threshold voltage of the memory cell. If the programmed threshold voltage is within a threshold voltage distribution of a plurality of threshold voltage distributions, the memory cell is reprogrammed, and if the programmed threshold voltage is not within a threshold voltage distribution of the plurality of threshold voltage distributions, the memory cell is allowed to remain at the programmed threshold voltage.
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BACKGROUND OF THE INVENTION
This invention relates to a semiconductor manufacturing apparatus and in particular to a semiconductor manufacturing apparatus in which circuit patterns are etched on a semiconductor wafer by a plasma reaction.
This invention relates to TI copending U.S. patent application Ser. Nos. 663,907; 663,901; 664,448; 663,903; 663,904; 663,804; 663,805; 663,906; 663,908; and 663,909 which by reference are incorporated herein. Copending application Ser. No. 664,448 was filed on Oct. 24, 1984 while the other copending cases were all filed on Oct. 22, 1984.
The manufacturing of semiconductor devices such as a 256K RAM or even up to a 1 megabit RAM device require precision dry etching with high repeatability, low particulate levels, reliable endpoint detection, multiple process capability and reliable feedback control to a microprocessor controller for reliable systems execution. An example of a prior art plasma reactor system is described in U.S. Pat. No. 3,757,733 which is assigned to the assignee of the present invention.
In the prior art systems, the transportation of silicon wafers through a plasma reactor required an opening in the reactant chamber that is large enough for the wafer to pass through. The mechanism that are typically used create particles that potentially impact yield of devices of the semiconductor wafers that are processed.
Chlorine and bromine gases which are typically used in the process during plasma etching are highly corrosive to the components that are used to build the plasma reactors. Over a long term operation, reactor components exposed to the plasma must be constructed of materials that are resistance to the corrosive effects of the plasma. Aluminum is an excellent material of construction for a plasma reactor, especially when it is protected by anodization. However, during etching, when a semiconductor or silicon wafer is placed on a substrate assembly that is anodized and used as an electrode, the substrate is protected from the plasma by the silicon wafer. However, each silicon wafer has a slice or flat to allow for crystallographic orientation. If the slice is placed on the substrate with random orientation of the flat, an annulus of equal width of the flat width plus the placement tolerance will in general be exposed to the plasma. Anodizing the whole substrate is impractical in that it is conductive towards the RF electrical power used in the plasma reactor. However, it is an insulator towards DC. It is known that electrically floating objects such as silicon wafers covered with oxides exposed to a plasma will acquire an electrical potential, the floating potential, above the ground of the system. It has been observed in production that an electrostatic repulsion develops between the wafer and the semiconductor substrate causing the wafer to randomly drift off its alignment position on the substrate.
Although several commercially available automatic wafer etch reactors use a confined plasma, none of the known systems provide a small gap which will not support a plasma and therefore confine the plasma within the small gap, use the same gap for both pumping the exhaust of gases from the reactors and for transporting the semiconductor wafers into the reactant chamber and thus keeping the reactant chamber simple and free of poorly controlled dead space within the reactor chamber.
Additionally, it has been determined that the gap between the collimator or electrode and substrate during process should be approximately around 0.040 inch for oxide processing. With a non-load locked system, the process chamber is vented to atmosphere which allows the electrode and collimater to move up to between 0.030 and 0.040 inch and the semiconductor wafer passes under the collimater. This is unreliable due to the fact that an inconsistent gap can now be achieved and the slice levitation varies, also, an automatic transportation system is impractical with the above operation. And in particular, the single slice dioxide and oxide etch processes have historically used the highest possible density to remove silicon dioxide. This elevated power density is far more difficult to control than any other type of etching operation. Also, highly selective etch processing often builds up deposits in the reactors. For this reason, these processes have tended to be limited in commercial applications.
SUMMARY OF THE INVENTION
A plasma etch system that processes one slice at a time is disclosed. The system is comprised of an entry loadlock, an exit loadlock, a main chamber, vacuum pumps, RF power supply, RF matching network, a heat exchanger, throttle valve and pressure control gas flow distribution and a microprocessor controller. A multiple slice cassette full of slices is housed in the entry load lock and after pumping to process pressure, a single slice at a time is moved by an articulated arm from the cassette through an isolation gate to the main process chamber. The slice is etched and removed from the main process chamber through a second isolation gate by a second articulated arm to a cassette in the exit loadlock. The process is repeated until all semiconductor wafers have been etched. The cassette loadlock system is able to evacuate a whole cassette of semiconductor wafers for processing which lowers the particulate environment for the slices and, provides a more stable environment for the slices by removal of moisture and preventing static discharges and additionally provides a safety feature that protects the operators from harsh or toxic gases that are traditionally used in semiconductor type plasma reactors.
This novel feature enables clean slice handling and eliminates the problem that traditionally occurs in the manufacturing of semiconductor devices in that there are no airtracks on the devices, no rubbing of the parts or semiconductor wafers. The semiconductor wafers are lifted off the cassette slot before movement and all belts, pulleys or drives are either external to the chamber or shielded within the main reactor chambers. The movement of the slices through the process is tracked with sensors.
The cassette loadlock apparatus according to the invention is a closed loop feedback process control system which insures that adequate pressure within the entry loadlock, the exit loadlock and the main chamber are controlled by microprocessor. The RF power during the reaction of the manufacturing process is monitored and controlled by a microprocessors. Gas flows are monitored and controlled by the microprocessor through mass flow controllers. End of etch is monitored and controlled by the microprocessor through a novel endpoint detection scheme.
The invention provides a multiple process capability by which multiple menus can be applied to a single slice in situ to achieve special etch profiles and other special processing requirements such as high selectivity of the etch films to the substrate and the etching of multiple stacked films.
These features provide a high etch rate with high resist survival through the use of a refrigerated liquid cooling on the top and bottom electrodes, thus allowing high power with good photoresist preservation during the operation.
These and other advantages and features of the invention will be more apparent from reading of the specification in conjunction with the figures in which:
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front elevation of a cassette load lock plasma reactor according to the invention;
FIG. 2 is top view of the cassette load lock plasma reactor according to the invention;
FIG. 3 is a block diagram of the control system for the plasma reactor according to the invention;
FIG. 4 is a block diagram for the RF circuit;
FIG. 5 is a block diagram for the endpoint detection logic;
FIG. 6 is a flow diagram of the endpoint detection process;
FIGS. 7a and 7b are waveforms illustrating the detection of an endpoint;
FIGS. 8 and 9 are the gas and vacuum flow diagrams;
FIGS. 10 and 11 are different views of the cassette load lock plasma reactor;
FIGS. 12 through 13 illustrate the wafer transport system;
FIGS. 14 through 17 are drawings illustrating the slice transport arm;
FIG. 18 is a view of the entrance port of the plasma reactor;
FIGS. 19 and 20 are views illustrating the operation of the gate valves;
FIG. 21 is a sectional view of the reactor chamber;
FIG. 22 is a top view of the plasma plate illustrating an anodized ring;
FIGS. 23 and 24 illustrate the electrical assembly;
FIG. 25 is a cross sectional view of an alternate embodiment of the reaction chamber;
FIGS. 26 through 28 are illustrations of the power load lock reactor;
FIGS. 29 and 30 are illustrations of the power load lock slice handler arm; and
FIGS. 31 through 34 are diagrams of the powered load lock chambers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a front elevation of a cassette load lock plasma reactor. The cassette of semiconductor wafers having photoresist patterns printed on them is placed in an entry load lock 21. A process is entered into a microprocessor that is contained within the cassette load lock reactor 23 by a keyboard 25 and a display 27. The menu is loaded in memory of the microprocessor and the process sequence begins. The entry load lock 21 is pumped down to a predetermined pressure or process pressure by a vacuum pump 29. The process pressure is maintained by feedback control circuit via a manometer that provides information to the microprocessor within the cassette load lock reactor 23 to control a throttle valve that is used to control the pump rate of the entry load lock 21. At the time that the entry load lock 21 is being pumped down to a process pressure and maintained there, the main chamber is either pumped down to main process pressure or is maintained at process pressure by a main chamber pump 31. A cassette elevator that is contained within the entry load lock 21 positions a first semiconductor wafer or slice that is to be processed by the cassette load lock reactor 23 and in the embodiment shown in FIG. 1, a cassette that is a handling device that stores a plurality or in the case of FIG. 1, 25 semiconductor wafers. Each wafer has patterns for semiconductor circuits printed on them by a photoresist process. The first semiconductor wafer is, as shown in FIG. 2, positioned by the cassette elevators located generally at 33. The semiconductor wafer is moved by an articulating arm 41 from the entry chamber 21 through an isolation gate valve 35 into a main process chamber 37 and placed on the main chamber bottom electrode 39 for etching. The position of the semiconductor wafer 143 is controlled by a feedback system and capacitive sensors that monitor the movement of the semiconductor wafer from the load lock chamber into the main chamber. After the slice is sensed to be safe in the main chamber 37 and the articulating arm 41 is sensed to be moved back into the entry load lock 21, the isolation gate 35 is closed and appropriate gases are applied from the gas distribution system 43 of FIG. 1 through the filtering systems generally at 45 and applied to the main chamber 37 by flow controllers 845 that are contained within each gas line 45. In the embodiment of FIG. 1, up to four gases may be applied to the main chamber for the process. Additionally, in FIG. 1, a nitrogen line 47 provides nitrogen gas for purging of the system when it is necessary to open up the main chamber, the entry load lock or the exit load lock 49.
As prescribed by the menu that was entered on the keyboard 25, pressure established by a throttle valve that is connected to the main chamber vacuum pump 31 and a manometer pressure sensor and the feedback loop process control is maintained by the microprocessor within the cassette load lock reactor 23. The cassette load lock reactor 23, in the embodiment of FIG. 1, is a plasma reactor and a plasma is formed by applying RF energy between the two electrodes that are contained within the main chamber 37 which ionizes the gases to form reactant gases that include ions, free electrons and molecular fragments. The gases are provided by the gas distribution 43 and the filters 45. RF power is provided to the main chamber 37 by an RF generator 51 and is applied to an RF matching network 53 by a conductor 55. The RF matching network controls and adjusts the energy that is applied between the electrodes that are contained within the main chamber by sensing the reflected power and converting this information to the digital signal that the microprocessor within the cassette load lock 23 will respond to.
In either etching or deposition process, the processing is automatically terminated by the microprocessor within the cassette load lock reactor 23. When in the etching mode, an endpoint is detected by an endpoint detector in the cassette load lock 23 which measures change in the optical emissions at a specific wavelength. The cassette load lock reactor 23 that is shown in FIGS. 1 and 2 provide multiple menus to be run on the same slice by the proper selection during the menu entry to the keyboard 25. After the process is complete, the slices or semiconductor wafers are automatically removed from the main chamber by a second articulated arm 57 that is located within the exit load lock 49 and is passed through a second isolation gate 61 and placed in an empty cassette whose position is positioned by the elevators at 63. At the completion of the processing of each semiconductor wafer, the process is repeated until all of the semiconductor wafers have been processed by the cassette load lock reactor after which the entry load lock 21 and the exit load lock 49 are brought up to atmospheric pressure by applying nitrogen through line 47 to purge the entry 21 or the exit load lock 49. The cassette is then removed and a new cassette is loaded for processing.
Heat transfer from the slice during etching is accomplished through a refrigerated system that is contained within a refrigerator controller 63 that refrigerates, in the embodiment of FIG. 1, an ethylene glycol--water mixture flowing through the top and bottom electrodes that are contained within the main chamber 37. A thermocouple sensor element is used to monitor the temperature so that the process may be controlled by the microprocessor that is contained within the cassette load lock reactor 23. Additionally, the oil that is used by the main chamber vacuum pump is re-circulated and filtered by a filter system 65.
FIG. 3 is a block diagram of a microprocessor control system 10 that is used to control the operation of the cassette load lock reactor 23. In particular, a central processing unit 17, which in the embodiment of FIG. 1 is manufactured with a 9900 microprocessor that is manufactured by Texas Instruments Incorporated of Dallas, Tex. or can be any central processing unit known in the art that has similar specifications as to speed, word length and operation.
The central processing unit 17 has an EPROM and RAM memory 19 which stores data and program instructions that are used to control the I/O devices that are connected to data bus 6. A language translator 15 is provided which is used to convert SECS II protocall into internal protocall that the CPU 17 will recognize. SECS II is an industry standardized interface for semiconductor equipment communication. The central processing unit or CPU 17 is connected to a data bus 6, which interfaces to the I/O devices. In particular, a battery memory RAM 13 stores menu data that is provided to the processor system 10 of FIG. 3 by the keyboard 25 and the display terminal 27. A digital I/O 3 provides digital controls to control the process to include the gate values and other controllable devices that are contained within the cassette load lock reactor 23 or the power load lock reactor 523 of FIG. 26 and receive status from these devices indicating the initiation of operation or the completion of operation. The status and control signals that are used to control the operation of the devices of FIGS. 1 or are listed in Table 1.
TABLE I______________________________________ Inputs (Status) and Outputs (controls) of the Digital I/O.Device Status Controls______________________________________Gate valve 35 opened/closed open/closeGate valve 61 opened/closed open/closeValves 704 opened/closed open/closeValves 705 open/closedValves 706 opened/closed open/closedValves 707 open/closedValves 708 opened/closed open/closedValves 709 open/closedValves 771 open/closedValves 773 open/closedValves 774 open/closed Purge on/offChamber gass on/offRF on/off on/offGas valves 710through 719 on/offElevator position #1 through 4Lid interlock on/offChamber pressureinterlock on/off______________________________________
An analog I/O device 5 provides analog control signals on its output by converting digital commands that are provided to it to analog signals by digital to analog converters. It additionally receives analog signals back from the cassette load lock plasma reactor 23 and the power load lock reactor 28.
Table 2 provides a listing of the signals that are converted to either analog signals from digital commands provided to the analog I/O device 5 by the microprocessor 17 or analog signals received by the analog I/O device and converted to digital signals by the D to A's that are contained within the analog device 5.
TABLE II______________________________________Analog commands and inputs for the analog device 5______________________________________Inputs analog to digital converters:1. Manometers 752 and 770 for cassette load lock,752, 772 and 775 for power load lock for monitoring pressure.2. Mass flow control devices 721 through 724 forcassette load lock plasma reactors and 721 through730 for power load lock reactors3. RF power control4. Endpoint detection 50,525. TemperatureCommands digital to analog converters1. Pump rate (throttle valves 704, 706 and 708) for maintainingpressure2. Flow rate set mass flow valves 721 through 724for the cassette load lock plasma reactor and721 through 730 for the powered load lock reactor3. RF power set4. Endpoint detection automatic gain control 50, 525. Temperature______________________________________
It should be noted that the analog I/O is just a parallel combination of digital to analog converters or analog to digital converters that are connected to the data bus 6 and the digital I/O 3 is a plurality of line drivers and receivers. Control is provided by the analog controller 7 which is a microprocessor such as a Texas instruments 9900 that is programmed according to the microcodes that are contained within table 3. Any microprocessor that is capable of meeting similar specifications may be used however, in lieu of the Texas Instruments 9900.
The data terminal is controlled by data terminal controller 9 which interfaces the display 27 and the keyboard 25 to the microprocessor 17 as well as displaying the voltage representation that is provided from the RF generator 51 and the analog control unit 7 by a data line 12. Table 4 provides the microcode for the data terminal controller 9. The movement of the semiconductor wafers from each cassette into the reactor chambers and from the reactor chambers into the exit chamber is controlled by a slice handler 11 through the operation of stepper motors 2 and in response to sensors 4. The slice handler 11 is a microprocessor which provides digital commands on its output and receives digital inputs from the sensors. The microprocessor is a device, again, such as the TI9900 and the microcode for which is provided in Table 5A is used by the cassette load lock reactor 23 and Table 5B is used by the slice handler, in the power load lock reactor 523. The program that is used to control the central processor unit 17 is a complex program and in the embodiment of FIG. 3 has a pascal compiler. A pascal listing of the programs that are stored within the CPU 17 is provided in Table 6 for the powered load lock reactor of FIG. 26 and Table 7 for the cassette load lock reactor of FIG. 2. Tables 3-8 are provided in U.S. patent application Ser. No. 663,901; Table 8 is an assembly language for subroutines used by the CPU 17 and stored in EPROM 19. U.S. patent application Ser. No. 663,901; is incorporated herein by reference.
FIG. 4 to which reference should now be made, there is shown a block diagram of the control circuit that is used to control the radio frequency energy that is applied to the load lock reactors 23 and 523. As was indicated in conjunction with FIGS. 1 and 3, the microprocessor 17 provides an output command to the RF generator 51 by a control line 32. The RF generator 51 includes an RF interface 26 and a generator 28. This is a commercially available unit as manufactured by Plasma Therm Inc. or can be a device such as that manufactured by Ortec Incorporated of Oak Ridge, Tenn. Status of the operation is provided back to the digital I/O 3 by a data bus 34. The RF output is applied from the RF generator 51 and in particular, the generator section 28 of the RF generator 51 to the matching network 53 by a conductor 55. The matching network includes a Bird Watt meter 22, manufactured by Bird Electronics of Columbus, Ohio, which monitors power that is applied to the upper electrode 30 that is contained within the main chamber 37 by an impedance matching circuit 53. The output of the Bird watt meter 22 is applied by an isolation amplifier to the analog to digital converter as contained within the analog I/O 5 and to the analog control microprocessor 7. Adjustment of the RF energy that is applied to the cassette load lock reactor 23 and power load lock reactor 523 is provided by the microprocessor 17 of FIG. 3. A digital to analog converter that is a part of the analog I/O 5, an isolation amplifier 25 in the RF interface 26 will cause the RF generator 51 to adjust its energy in response to the analog signal that is applied to it. This of course, provides a feedback loop for the host microprocessor 17 to control the plasma operation according to the prescribed menu that is entered by the keyboard 25.
FIG. 5 is a block diagram of the control system that is used to detect the endpoint of the operation. In the embodiment shown in FIG. 5, there are dual channels used in the endpoint detection process. Quartz windows 58 and 60 provide and optical opening into the main chamber 37. Adjustable filters 62 and 64 can be selected to ensure that only light having the proper wavelength is applied to the endpoint detector 70. There is, as described earlier, two channels, an A channel and a B channel. The A channel has a light detector 54 which is a device such as a photo multiplier or silicon detector. The B channel detector 56 of course is a similar device. Each channel has an automatic gain control circuit 50 and 52. The gain of the automatic gain control circuits 50 and 52 is controlled by the analog controller 7 and the analog I/O 5. In particular, the output of the automatic gain control circuit 50 for channel A is applied to an analog to digital converter 40 that is contained within the analog I/O 5 and applied to the analog controller 7 where the data is processed and passed onto the host microprocessor 17. Adjustment of the automatic gain control circuit 50 is provided by either the host microprocessor 17 and/or the analog controller 7 by providing a digital command to a digital to analog converter 42 that is contained within the analog 5. The digital to analog converter 42 provides an analog signal to adjust the gain on the automatic gain control circuit 50. The output of the channel B automatic gain control circuit 52 is converted to a digital signal by an analog to digital converter 44 that is contained within the analog I/O 5 and is processed by the analog controller 7 for averaging of data to be used by the central processor 17. An output to set the automatic gain control circuit 52 is provided by a digital command being provided by the analog controller 7 whether originated from the analog controller 7 or the CPU 17 and is converted to an analog signal by the digital to analog converter 46 and applied to set the automatic gain control of the channel B automatic gain control circuit 52. Additionally, the display at 27a provides display of the setting up of the automatic gain control 50 and 52. An auxiliary display is provided from the analog controller 7 and a digital to analog converter 48. These provide meter displays of the endpoint detector circuit.
The operation of the endpoint detector allows the user through the keyboard entry 25 to define parameters which can be defined as two classes, the detection mode and the detection parameters. The detection mode parameter is selected by the users and provide the following mode of operation. No endpoint mode is when the endpoint detector does not operate. Either channel A or channel B detector outputs can be monitored and applied to a strip chart recorder via the display outputs 27a. Channel A endpoint selects a signal from channel A detector to be used to determine the endpoint. The channel B mode selects the signal to be used as the endpoint detection from channel B. The a-b endpoint detection subtracts the output of B from channel A. In this mode, the signal used for endpoint detection is formed by subtracting the detector B signal 56 from that of the A detector 54. The purpose of this mode is to allow the signal to noise ratio of the combined signals to be increased by removing correlated noise during the subtraction process. The final mode of operation is the a+b mode in which the detector outputs from channel B are added to the detector outputs from channel A. This mode is useful to increase the available amount of total signals for the detection process. FIG. 6 provides a flow diagram of the adjusting of the automatic gain control circuits 50 and 52 and the operation of the endpoint detector circuit as is programmed by the analog controller 7. The endpoint detector of FIG. 5 is designed to detect the endpoint when the following parameters are set. The window length, T(w) is the time interval during which endpoint signal after signal process must remain greater than its selected threshold value for the endpoint to be determined. The filter factor T(k) determines the time interval used to perform the digital differentiation of the endpoint signal by the microprocessor 7. The +/- threshold V(t) is the percent of voltage of an upper limit, such as eight volts in the embodiment of FIG. 5 and is said to correspond to either positive or negative slope endpoint signal. This threshold is selected as a percent of the maximum voltage. The delay to detector time T(d) is in units of seconds as the time interval from the application of RF energy to the main chamber 37 to the start of endpoint detection. For example, entering of a number 40 to the keyboard 25 means that the endpoint detector will not start looking for the endpoint until after 40 seconds has expired after the RF energy is applied to the main chamber 37 by the RF generator 55. FIG. 6 is a flow diagram of the process in which the microprocessor 7 is used to perform all the signal processing for the endpoint detectors. After the initialization of turning on RF energy at circle 100, the unit waits for the delay to detect time to expire at diamond 101. The adjustments of the AGC unit 50 and 52 is performed at block 102 and in the embodiment of FIG. 5, the AGC is adjusted to provide an output of five volts. The AGC is then sampled and in the embodiment of FIG. 5, the sample rate is every one-tenth second. This is illustrated by the control loop at 103 and includes the steps of reading the signal level at block 105, converting the signal level to a digital signal by the analog digital controller of either 40 or 44 at block 106 computing the average signal over a period of time over block 107, computing the difference using the filter factor at block 108 and comparing to see if the difference or summation i.e., a-b, a+b or either a or b is greater than or equal the threshold voltage at block 109. This loop continues until the difference including at block 109 is greater than or equal to the voltage threshold in which case the rendered length is incremented to insure that the window length has expired as indicated in by control loop 110. If the window length has expired, then an endpoint detection is indicated at block 111 and the operation is complete and exited from at circle 112. It should be noted that in performance of the AGC operation, the analog controller 7 reads a data word, interprets it as a voltage, compares it to a reference such as 5 volts. It then computes a gain adjustment word and sends it to the digital to analog converter either 42 or 46 which converts a digital word into a voltage level. This voltage is applied to the automatic gain control circuit either channel A AGC 50 or channel B AGC 52, of the circuit which act as of course a multiplier. In this matter, the gain is adjusting using a successive approximation until the output of either or both the channel A AGC 50 or the channel B AGC 52 is at a predetermined voltage level which in the embodiment of 55 is five volts.
FIG. 7 illustrates the operation of the control loop of FIG. 6 graphically. In particular, FIG. 7a is a curve that illustrates the signal level output from either the A detector 54 or the B detector 52 by waveform 114. In FIG. 7b, waveform 116 illustrates the output from the analog controller 7 as is displayed on the auxiliary 1 output of the display 27a in which at point 118 the RF power is turned on. The window T(w) is represented by dimension lines 115. At point 119, the threshold voltage V(t) is exceeded and the endpoint is detected. When an endpoint is detected, a square wave output as illustrated by waveform 116 is produced.
GAS AND VACUUM CONTROL SYSTEM
The vacuum and gas control system for the cassette load lock plasma reactor 23 is illustrated in FIG. 8 to which reference should now be made. The gas from the gas distribution 43 of FIG. 1 is applied to a manifold 750 by a mass flow controller 721 through 724. The mass flow controllers are controlled by the analog inputs from the control system 10 and additionally valves 710 through 713 are cotrolled by the status I/O 3 of the control system 10 and are on/off valves. The gases mixed in the manifold 750 and applied to the main chamber 37 where the temperature of the reaction within the main chamber is monitored by a thermocouple 751. The thermocouple 751 is an analog input to the analog I/O 5 of the control system 10. A vacuum pump 31 pulls a vacuum in the main chamber 37 when the block valve 709 is open. The flow rate is controlled by a throttle valve 708 which position is fed into the analog input and is set by the output from the analog input of the control system 10. Sensors 2 senses the position of the silicon wafer within the main chamber 37. The vacuum of the entry load lock 21 and the exit load lock 49 is provided by pump 29 as was discussed in conjunction with FIG. 1. Gate valves 705 and 707 are set open and the pump rates are controlled by throttle valves 704 and 706. The gate valves are interfaced in the control system 10 at the digital I/O 3 and the throttle valves 704 and 706 are controlled by the analog I/O card 5. Additionally, the positioning of the semiconductor wafers within the entry load lock 21 and the exit load lock 49 is provided by the sensors 2 and motors 4.
FIG. 9 to which reference should now be made is shown the gas and vacuum flow diagram for the power load lock 523. The difference in the powered load lock 523 and the cassette load lock 23 is due to the fact that the entry load lock can have a plasma reaction as well as the exit load lock 49. In this case there are 2 vacuum pumps required, 29a and 29b. The entry load lock has a gas manifold 760 which mixes three gases from three mass flow control valves 725 through 727 which are controlled by the analog inputs and outputs from the control system 10 and are activated by setting of gate valves 714, 715, 716. The exit load lock 49 can have a plasma reaction based upon the mixture of up to three gases in a manifold 761 that are controlled by mass control valve 728, 729 and 730. The on/off operation of the gas flow into the manifold 761 is provided by the digital I/O 3 of the control system and controls the valves 717, 718, 719 as is the case with the gas valves into the entry load lock 21.
In FIG. 10, cassette load lock reactor to which reference should now be made, there is shown a front view of the cassette load lock reactor 23 in which the keyboard 25 provides, as discussed earlier, a data entry point that is the information of which is displayed on a display 27. The distinguishing features of FIG. 10 also illustrate a quartz window covered with plexiglass or other plastic 120 for viewing by the operator of the plasma reaction that is going on within the main chamber 37. This also enables the operator to insure that the semiconductor wafer is in the proper position between the electrodes during the reaction process. Additionally, the tuning of the RF generator 51 is illustrated by tuning meter 123 and the DC voltage that develops across electrodes is displayed by the DC voltage meter 122. This of course, in FIG. 3 is provided by the analog control 7 to the terminal controller 9 via data line 12.
FIG. 11 is a top view of the cassette lock load plasma reactor 23 in which the keyboard 25 is illustrated showing switches 133, and keypads 135. The cassette that contains the semiconductor wafers to be processed is placed within the entrance load lock 21 by lifting a vacuum tight lid 137 and rotating it around hinges 124 to place the cassette into the entrance chamber 21. Glass window 128 provides for visual inspection of the placement and the transfer of the semiconductor wafers from the entrance load lock 21 to the main chamber 39. Similarly, at the completion of the process of a cassette of semiconductor wafers, the lid 139 of the exit load lock 39 is lifted by rotating the lid 139 around the hinges 126 by removal of a cassette of processed semiconductor wafers.
SEMICONDUCTOR WAFER HANDLING INCLUDING TRANSPORT ARM
FIG. 12, to which reference should now be made, there is shown a cassette 141 containing a plurality of semiconductor wafers or slices 143. A slice transport arm 145 is placed into the cassette 141 and the cassette 141 is lowered by an elevator 156 that includes lead screw 152, stepping motor 4, and sensor 2, until the semiconductor wafers 143 rest on the slice transport arm 145 in the middle of the slice opening 147. Because the slice is not touching any part of the cassette as it leaves during the rotation of the slice transport arm, there is no friction between the semiconductor wafer 143 and the slice handling arm 145. This feature minimizes particular generation as the slice leaves the cassette 141. The position of the slice transport arm 145, the cassette 141 are controlled by the slice handler 11 of FIG. 3 and the motors 4 and sensors 2. The cassette platform 154 provides a reference position for the cassette 141 and thus the exit position of the cassette can be determined with the sensor 2 and precise control of the elevator 156. After the semiconductor wafers leaves the input cassette 141, it may be placed over a primary staging platform 149 or on the reactor substrate as is illustrated in FIG. 13. The semiconductor wafer 143 is lowered to the staging platform 149 by a lifting assemblies 151 which provide a plurality of lift pins 153 that lifts the semiconductor wafer 143 off of the slice transport arm 145. The unloaded arm is then removed from under the semiconductor wafer 143. When the unloaded slice transfer arm 145 is clear, the semiconductor wafer 143 is lowered onto the staging platform 149 which centers the semiconductor wafer 143 through the action of the centering pins 155. When the entrance slice handling arm 145 is moved under the platform 149 and the slice after being raised by the pin assembly 151 and the pins 153 are retracted the semiconductor wafer is lowered onto the slice transport arm 145. When the main chamber 37 is ready to accept a semiconductor wafer 143, the entrance load lock slice transport arm 145 moves into the main process chamber 37 through the gate valve 35. (FIG. 2) The semiconductor wafer 143 is then lifted off the slice transport arm 145 and the slice transport arm is then removed from the main process chamber. The semiconductor 143 is then lowered onto the substrate within the main process chamber for processing The semiconductor wafer 143 is removed from the main process chamber to the output chamber 49 by reversing the above discussed sequences and using the output chamber slice transport arm 147. FIGS. 14 through 17 illustrates the slice transport arm 145 as is used on the entrance chamber transport arm 41 or the exit chamber transport arm 57. A fork 151 is designed with touch pads 155 for balancing of the semiconductor wafers 143 thereon. The fork is rotatable around axis 157 which is adjustable through the setting of set screws 159. A main arm 161 rotates around axis 163 and is driven by a stepping motor to FIG. 17 which is coupled to the slice transport arm 145 via coupling means 165 and FIG. 15 feed through 180 which is a vaccum tight seal load lock walls 181. The wafer transport arms is mounted to the chamber by mounting bracket 164 and through holes 165 and 167. The arm assembly 161 contains a seal chain drive mechanism which is driven by a chain 172 of FIG. 16 which rotates causing sprocket 175 to rotate the fork 151 after being driven by sprocket 176 which is connected to the drive shaft 163 and coupling 165 of FIG. 15. As illustrated in FIG. 15, the slice transport arm is very narrow to facilitate it sliding under the semiconductor wafers 143 and entering the gate port between the load locks and reaction chamber.
GATE VALVES FIG. 18 is a side-view showing the entrance or the exit into the main chamber 37. A gate port 184 allows the slice transport arms 145 to transfer semiconductor wafers 143 into and out of the reactor chamber 37. A gate valve 35 or 61 which are identical device is shown in FIGS. 19 and 20 and include a gate plate 183 which presses against the sides 182 of the main chamber 37 to to provide a seal thereto. It is important to keep particulate emissions at a minimal and this is achieved through a camming action on gate valves. Guide rails 180 and 181 guide the gate valve 35 or 61 up to the gate plate 183 and comes in contact with stops 187 and 186. At this point, the camming action that is precipitated by the linkage 190 that includes a first arm 191 and second arm 193 going into place and locking as shown in FIG. 20 pressing the gate plate 183 against the gate stop 186 and 187 and transferring the gate carrier 189 into the up position. A spring bias provided by spring 195 holds the gate carrier 189 in the position shown in FIG. 19 until the bias provided by the spring 195 is overcome by the camming action through the rotation of the arms 191 and 193 via the rotation of a drive shaft 197 that is controlled by an air cylinder.
FIGS. 19 and 20 to which reference should now be made, illustrates a power load lock plasma reactor unit 522 in which a cassette 400 hundred contains a plurality of slices and is housed outside of the entry load lock 21. A process menu is entered into the microprocessor that is contained within the power load lock plasma reactor 523 and the process sequence begins. A single slice that is housed within the entry cassette 400 is moved from the entrance cassette 400 through the isolation gates 435 which are devices such as that disclosed in conjunction with FIGS. 19 and 20 and is carried to the power entry load lock with articulated arm 441. The power load lock 21 is pumped down to manometer to the microprocessor through a throttle pressure controller and the pre-etch process is begun within the entry load lock 21. The first semiconductor wafer is at the completion of the pre-etch process is moved from the entry load lock 21 through a second isolation gate 35 into the main chamber 37 and placed on a main chamber bottom electrode for etching. This is accomplished in the same manner as was discussed in conjunction with FIGS. 1-18. Feedback of the slice movement is accoplished by capacitive sensors in the load lock chambers and main chamber. After the semiconductor is sensed to be safe in the main chamber and the articulated arm is sensed to have been moved back from the main chamber into the entry load lock 21, the isolation are closed and the appropriate gases up to 4 are provided from the gas distribution 45. It should be noted that the gas distribution also provides gas to the entry load lock 21 up to 3 for the pre-etch reaction and to the exit load lock 37, additionally up to 3 gases may be applied there for post-etching and of course all of these are in addition to the purge gas which in the embodiments of these are in addition to the purge gas which is embodiments of FIGS. 1, 19 and 20 is nitrogen. As prescribed by the menu that has been entered by the keyboard 25, pressure stabilized by a throttle valve capacitor manometer feedback to the microprocessor, RF power is activated and applied from the RF generator 51 and automatically turned by the RF matching network as was discussed in conjunction with FIG. 4, with control feedback from the reflected power to the microprocessor 7. Etching of the film is automatically terminated by the microprocessor 7 via the feedback from the endpoint detector as was discussed in conjunction with FIG. 6, seeing a major change in the optical emission at a given wavelength. Of course, multiple menus can be run on the same slice by the proper selection during menu entry.
At the completion of the process, the semiconductor wafer is automatically removed from the main chamber 37 by an articulated arm 57 in the exit load lock 59 and placed in the exit load lock for the post-etching process. After processing in the post-etching load lock, the semiconductor wafer is moved to the exit elevator cassette 401 by articulated arm 541. Additionally, cooling is provided to the main chamber as well as the post-chamber and the entry chamber via temperature controller 63. Viewing windows 461, 462 allows viewing of the post-etch and pre-etch operation, respectively. FIGS. 21 and 22 are mechanical illustrations of the articulated arm 441 and 541 in which each has a fork 555. The articulated arms are mounted to the power load lock assembly by pedestal 453 and include a central arm section 161 which rotates around axis 163 as was discussed in conjunction with FIGS. 11, 12, and 13.
ELECTRODE AND COLLIMATOR ASSEMBLY
FIG. 21 is a sectional view of the main chamber 37 as seen from section lines 23 of FIG. 19. Initial input of the semiconductor wafer 143 through the opening 145 onto a substrate or wafer plate 206. The wafer plate is in position to allow clearance for the semiconductor wafer 143 and the fork 151 to position the semiconductor wafer over the wafer plate 206. Pins 153 will lift the semiconductor wafer off of the fork 151 and after its removal, lower the semiconductor wafer onto the substrate or wafer plate 206. The embodiment shown in FIG. 26 provides a two position substrate. It is generally accepted that during processing in the powered load lock that the substrate should be at different positions for different modes of operation, such as 0.040 inch for oxide processing. In the case of the cassette load lock, the substrate position is varied only for oxide processing, in all other etching modes the substrate is stationary. To achieve this, the wafer plate 206 has two positions, a low position, which is expanded and a process position.
In the embodiment of FIG. 25, two stainless steel bellows an interbellows 220 and an outer bellows 221 form a chamber between the bellows at 224. By introducing compressed air into lines 211, pressure is built up in the chamber between the bellows and this causes the movement of the substrate 206 to be implemented. Under initial operation, air is introduced into, an air cylinder, not shown, which raises the pins 153 for removal of the semiconductor wafer 153 from the fork 151. The centering pins 155 are raised by introducing air into air cylinder, not shown, which brings the guides 155 into position to center the semiconductor wafer 143 onto the wafer plate 206. The wafer plate 206 is in position for the process which is defined by the opening as indicated by dimension lines 228 between the cathode 230 and the substrate or top of the wafer plate 206. A consistent process gap between the cathode 230 and the substrate 206 is maintained during processing. A consistent opening for movement of the semiconductor wafer 143 between the collimater 430 and the substrates 206 is also maintained during slice movement. A constant low pressure (1 TORR) is maintained in the main chamber 37 during slice handling, this eliminates the slice contamination caused by lifting of the main chamber to the atmospheric pressure and facilitates the use of the slice transport arm 141.
Line 212 FIG. 21 is connected to the gas distribution 43 via filters 45 (FIG. 1) and provides for the entrance of gas to be processed in between the cathode 230 and the substrate 206. Lines 210 allow for cooling of the process reaction by the temperature controller 63 to flow through channels 232 and 242 to cool the semiconductor wafer 143 when placed on the wafer plate 206. Ring 205 is an isolation substrate ring that is isolated from the substrate 206 via isolation assembly 207. The ring consists of the body of the ring itself, 205, a rectractible slice centering lip 209, isolation mechanism 207 which is made of a metal but with small thermal contact or with an insulator such as teflon which more completely isolates the ring 205 thermally and electrically with a possible ring extension shown at 231. The ring extension 231 is of course to increase the surface area of the top of the ring which increases the area of the overlap between the ring and the collimator itself in the electrode assembly 240.
This extension has been found to improve the effectiveness of the collimator in eliminating plasma expansion beyond the outside ring. The ring 205 is used to provide isolation and to aid in the control of plasma discharge which occurs during the reactor process between the cathode 230 and the substrate 206. The electrode assembly includes an electrode or cathode 230 to which RF voltage is applied via attachment to the plate 250. The electrode or cathode 230 is surrounded by a collimator 430, which includes insulator 251, which is in turn surrounded by a grounded plate 252 to all of which have a cylindrical symmetry about an axis position through the center of the electrode as indicated by line 256. When placed a small distance above a flat grounded substrate 206, the electrode assembly creates a volume as indicated by dimension lines 228 which can effectively confine a high power density plasma, while maintaining a sufficient channel for flowing gas through the lines 212 in the direction as indicated by arrows 258 and for observing the plasma optically through the window 120. As discussed earlier, the chamber can be widened for automatic transport of the semiconductor wafers from outside of the main chamber 137. By having a confined high power density plasma, high rate uniform anisotropic etching, especially for silicon dioxide and silicon nitrides, can be achieved. The ring 208 has an annulus of a width equal to the distance between the placement pins 155 and pin 209 and is an area which is generally exposed to plasma due to the fact that most semiconductor wafers have a flat portion that is used for alignment. The reacting plasma will attack the semiconductor wafer plate 206 or substrate and create damages. In FIG. 22, by anodizing an area 208 around the substrate 206, an area in width as indicated by dimension lines 270 will prevent etching of the substrate 206 when as shown in FIG. 21, a semiconductor wafer 143 is placed on the substrate 206. In general, the substrate 206 is manufactured with aluminum which is highly corrosive if not protected by anodization.
The cathode assembly 230 of FIG. 21 is shown in FIGS. 24 and 24 and includes a top plate 269 and a bottom plate 268. The top plate 269 has a gas inlet 305 to allow the cooling gas to enter via from line 212 and a water cooled line 304 which removes heat from the plate 268. Recess gas flow channels are provided at 307 and areas 306 provide for thermal contact betwen the bottom plate 269 and the top plate 268. The bottom plate 269 is illustrated in FIG. 23 and the top plate 268 is illustrated in FIG. 24. The thermal contact area must be maximized without restricting the gas flow. This is illustrated in the top plate where there are many drilled holes in area 301 and the lines in 302 allow for gas flow channels for the top plate 268.
FIG. 25 is alternate embodiment of the substrate 206 which has dual positions. The alignment pins 155 and lift off pins 153 are controlled by lifting of the carriage assembly 312 which is guided into place by wheels 310. The carriage assembly 312 is lifted by the levers 311 being raised under compressed air applied to a cylinder contained within a housing at 313. The positioning of the substrate 206 is accomplished by feeding air in between an interbellows 220 and an outer bellows 220 into a chamber 212 at air ducts 211 which causes the wafer plate 206 to be raised or contracted depending upon the air pressure that is contained within the air chamber 224.
Insert E--Powered Load Lock Reaction
FIGS. 31 through 34 illustrate the load lock chambers which provide for pre-etch processing in the entrance load lock through a plasma assisted reaction, and post-etch processing in the exit load lock through a plasma assisted reaction. In FIGS. 31 and 32 the gas from the gas distribution manifold 760 is applied by line 781 through a baffling port 999. The feedthrough 886 as shown in FIG. 32 provides for movement of tubing 781 to provide for adjustable spacing of the electrode assembly 987 to control the volume of reactants area 988. This is illustrated in FIG. 32. In addition to the tubing 786, the electrode assembly 987 includes feedthrough 886 and O ring seals 981 and includes a gas distribution assembly 889, a retainer 888 that holds the electrode 890 onto the gas distribution assembly 889. The retainer 888 also seals the electrode assembly 987 to the walls of the collimator 891, which is made of insulating materials. The gas is distributed through the electrode 890 by means of plurality of distribution holes 991. The slice handling mechanism which is shown at 882 has a fork 873 which lifts a slice from outside of the load lock chamber and centers it on ring 876 and then rotates around axis 877 to position the slice over the bottom electrode 875. The spacing 871 and 872 is 1/8th of an inch so as to minimize its effect on the plasma that is contained within volume 988. The slice handler 441 was discussed in conjunction with FIGS. 29 and 31. The substrate 875 has cooling channels 879 to facilitate the cooling of its semiconductor slice that is mounted to the substrate during its reaction. Function 870 is designed and positioned so as to ensure that the gaps 871 and 872 are at a minimum.
FIG. 34 illustrates the bottom electrode in which the reactant gases are removed from via line 896 which goes to vacuum pumps 29a or 29b and includes a mechanical housing 885 and a bellows chamber 884. Within the bellows chamber 884 is a bellows assembly 878 which moves the bottom substrate 875 by the operation of an air cylinder pressing shaft 978 in the upper or lower position. The compressing of the bellows 878 positions the substrate 875 to ensure the proper reaction as was discussed in conjunction with the main chamber.
Although the embodiments of the invention have been described with some particularity, one skilled in the art would know that the substitution of elements will not depart from the scope of the invention as limited to the appended claims.
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A plasma reactor for the manufacturing of semiconductor devices has powered loadlocks and a main process chamber where slices can be processed one slice at a time with pre-etch plasma treatments before the main etching processing and afterwards receive a post etch treatment. The system comprises powered loadlocks, a main chamber, vacuum pumps radio frequency power supplier, radio frequency matching networks, heat exchangers and throttle valve and pressure controllers, gas flow distribution and microprocessor controllers. The semiconductor wafers are automatically fed one at a time from storage cassettes through isolation gates with articulated mechanical arms to a powered entry loadlock for pre-etching processes. At the completion of the pre-etching processing, the semiconductor wafer is transferred to the main chamber automatically for the main etch process and then to the powered exit loadlock for post etch treatment and finally to an output cassette.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Non-Provisional Application claims benefit to U.S. Provisional Application Ser. No. 60/751,864 filed Dec. 20, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods and devices that give a fluid stream the appearance of being lighted.
BACKGROUND OF THE INVENTION
[0003] There are numerous known methods of object coloring by a conventional filtered light source. The most common is theatrical lighting, where a powerful incandescent lamp, strategically positioned inside of the reflector, shines the light onto the object through a colored diffuser. The same principle is used in flashlights, regardless of the lamp type. A disadvantage with these devices, and the principles under which they perform, is they color only the surface to which they are pointed. If there is a need to cover a large object, a stronger light or multiple light beams are needed.
[0004] When it comes to other objects, such as moving transparent fluids, e.g., water, the refractory properties of these objects are different from those of solid objects. Consequently, the known methods are neither practical nor perform to a reasonable satisfaction when it comes to lighting these objects. In addition, none of the known devices are capable of uniformly coloring the moving fluid along the flow direction. Moreover, customer demand for aesthetically pleasing optically enhanced static or dynamic fluids creates a need in the art for a low-cost, low-energy, compact device to provide water stream coloring in devices such as common household appliances and fixtures.
[0005] The present invention addresses these and other drawbacks with known lighting systems.
SUMMARY OF THE INVENTION
[0006] In one aspect, the present invention is directed to devices and systems configured and adapted to give a fluid stream the appearance of being lighted. Different colors of light, such as those provided from light emitting diodes (LEDs), may be used to generate the optical illusion of flowing colored fluid, which is aesthetically appealing and creates a variety of moods, such as relaxing or celebratory.
[0007] In some embodiments, the fluid illumination may be accomplished by a light source directed towards a fluid stream from an external angle. Alternatively, the light source may be aligned in the direction of the fluid stream, lighting it substantially internally. In yet other embodiments, the fluid illumination may be enhanced with the employment of reflective surfaces that bounce light around and through the fluid stream. In alternative aspects, the fluid surface area may be increased by generating turbulent flow, which increases the appearance of the fluid being lighted due to the generation of additional reflective fluid surfaces in the turbulent flowing stream. In one aspect, the turbulent flow may be achieved with the use of a separator to separate a single fluid stream into a plurality of micro-streams.
[0008] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates an embodiment wherein a fluid travels in a single lighted stream in accordance with the principles of the invention.
[0010] FIG. 2 illustrates an LED or light holding device for use in conjunction with a stream of fluid in accordance with an embodiment of the invention.
[0011] FIG. 3 illustrates an exterior light source device comprising two LED holders with reflectors, and a fluid separator in accordance with an embodiment of the invention.
[0012] FIG. 4 illustrates a cross-section view of an internal light source device comprising an LED holder and a cylindrical fluid dispenser in accordance with an embodiment of the invention.
[0013] FIG. 5 illustrates a coaxial light source device comprising a transparent LED holder, light shields, and a fluid separator in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The present invention may be embodied in many forms. Referring to the Figures, there are depicted various aspects of the invention. In one aspect, the invention is a device adapted to give a water stream, such as that dispensed from a refrigerator, for example, the appearance of being lighted. Although water is discussed, the invention is capable of use with any transparent or nontransparent fluid or fluid material. A feature of the invention is to illuminate the stream of water as it travels from a dispenser to a receptacle, for example a cup.
[0015] The surface of water acts as a reflector of light when it has a greater index of refraction, or density, than another material such as air. Since light from an outside source generally reflects off the surface of the water back into the air, an increase in surface area will intensify the optical effect. Moreover, water tends to act as a piping mechanism when light is introduced into the interior regions of a water stream, making a fiber optic by carrying light down the water stream's axis and emitting very little light normal to the outer surface. By inducing turbulence, it is possible to disrupt the surface of the water, thus decreasing the uniform specularity of the reflector (water) and causing a randomization of the light reflecting from the air to water interface. This randomization of light counteracts the piping property of any light within the stream and gives the water its desired reflective property. Turbulence may be induced in a water stream by a separator, which is an orifice like device similar in structure to a shower head that takes a large stream of water and separates it into a plurality of smaller streams. The generation of the plurality of streams greatly increases the surface area, and thus light reflection, of the water.
[0016] In another aspect, light may travel through a medium, such as plastic, and then into water. The plastic will generally have a density that is either lower than or higher than the density of water. In the case of plastic having a lower density than water, the light will have a tendency to stay within the water stream. Also, the light will mainly stay within the water stream when it travels through the air, illuminating the water. In general, however, it is common for most plastics to have a higher density than water. In this case, light will have a tendency to leave the water and transfer back to the plastic.
[0017] Referring to FIG. 1 , a water stream 10 lighted by a device or techniques of the invention is illustrated. The water stream 10 may flow out of a dispenser 12 from a refrigerator, for example, and into a receptacle 14 , for example. It should be understood that the dispenser 12 is exemplary of the numerous types of dispensers or devices that dispense a fluid and that may be used with the lighting techniques of the invention, and that a refrigerator is exemplary of the various applications of the invention. Other contemplated applications include other household appliances or fixtures, such as lighted shower streams, water faucets, tabletop illuminated fountains, illuminated cocktail glasses, to name a few.
[0018] Referring to FIG. 2 , an exemplary water illuminating device 20 of an embodiment of the invention is depicted. The water illuminating device 20 may be mounted on an upper end 21 of a transparent tube 24 to a source of water, such as a refrigerator drinking water line. As water flows into device 20 and through the transparent tube 24 , an LED 22 (generally depicted) or other suitable light source, disposed on a support 28 at a distance from, and normal to, the tube 24 , provides light that is directed into the water stream at an angle by a light director 26 . The light director 26 comprises a concave reflective surface that in an aspect may form generally a cone-shaped configuration, attached along the wide end of the cone to the support 28 and along the narrow end of the cone to the lower end 23 of the device, surrounding at least in part the transparent water tube 24 . The cone-shaped light director may also completely surround the water tube 24 . The light director 26 may comprise any acceptable material, such as a metal, provided that it includes a reflective surface, and functions by reflecting any stray light rays back towards the water stream 10 before it is dispensed through the lower end 23 of the device 20 . With the device 20 , the fluid that exits the tube 24 will have the desired illuminated effect. While an LED is described as the light source, any other suitable light source may be used with the invention. It should be further understood that the number, size and color of LEDs may vary depending on the application and the desired lighting effect. Additionally, other shapes and configurations of the light director are possible to direct light emitted by the LEDs back into and through the fluid stream.
[0019] Referring to FIG. 3 , another aspect of the invention provides separation of a single fluid stream into a plurality of micro-streams 37 , as illustrated in device 30 . The separation is performed to create a greater illuminating effect than possible with a single fluid stream. The device includes a body 33 , an external light source such as LED 32 , and in some aspects, two LEDs with conical reflectors 34 disposed at the lower end of the device 33 . Fluid, for example water, is caused to flow into the device 30 through an upper end 31 , through a generally vertical tube 35 and into a separator 36 disposed at the lower end of the device 33 . The separator 36 may comprise either a plastic or metal material, for example, or a combination thereof. The separator 36 operates to divide the water stream via any suitable technique. In an aspect of the invention, the separator 36 may comprise a plurality of generally parallel vertical channels, each having a substantially smaller diameter than that of tube 35 , to create turbulent flow by separating the water from a single stream into a plurality of micro-streams 37 . The micro-streams have a greater combined surface area than the single water stream and thus will provide a greater illumination effect. In operation, light provided by the LEDs 32 is directed at the micro-streams 37 , both directly from the LEDs 32 and via reflection of stray light rays by the reflectors 34 . The light reflects off the micro-stream 37 surfaces, generating the appearance of illumination of the water. The device 30 may be used in any of the applications described herein.
[0020] Referring to FIG. 4 , a cross-section view of another embodiment of the invention includes a device 40 that combines the features of an intenial light source LED 42 to illuminate a flowing fluid, such as water, and a cylindrical output 44 to create turbulent flow. In contrast to devices 20 and 30 , described above, water is caused to flow into device 40 from a side entrance 41 and through a generally horizontal tube 43 into the cylindrical output 44 . The water exits device 40 from a lower end 45 , forming the shape of the walls of a cylinder. LED 42 is disposed central to the cylindrical output 44 . In this position, the LED 42 will direct light at the interior of the turbulent water flow 46 as it is dispensed, thereby illuminating the water.
[0021] Referring to FIG. 5 , another embodiment of the invention relates to a coaxial light source. Device 50 includes a clear or transparent body, such as formed by a material comprised of acrylic, and reflective shields 52 preferably made of black material disposed along the sides of the device 50 (or around the periphery of the device 50 ) to bounce light beams back and forth within the clear body of the device 50 . A fluid, such as water, is caused to flow into device 50 from a side 51 and through an L-shaped tube formed by portions 53 and 55 . The generally horizontal portion 53 is in fluid communication with the generally vertical portion 55 of the tube. The vertical portion 55 directs the flow of water into a separator 56 disposed at the lower end 57 of device 50 . The separator 56 may comprise a plurality of generally parallel vertical channels, each having a substantially smaller diameter than that of vertical portion 55 of the tube to create turbulent flow by separating the water from a single stream into a plurality of micro-streams 58 . An LED 54 may be disposed at the upper end 59 of device 50 directly above vertical portion 55 of the tube to provide light in the direction of the water flow. The light from LED 54 on the water stream and the plurality of micro-streams 58 formed by and descending from the separator 56 , combined with the rays of light that may bounce throughout the transparent body of device 50 by the reflective shield 52 , provide the appearance of illumination of the dispensed water. Again, as with all the embodiments, while an LED is described as the light source, any other suitable light source may be used and the number, size and color of LEDs may vary depending on the application and the desired lighting effect. Also, other shapes and configurations of the reflective shield are possible to direct light emitted by the LEDs back into and through the fluid stream.
[0022] Variations and modifications of the foregoing are within the scope of the present invention. It should be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
[0023] Various features of the invention are set forth in the following claims.
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The invention relates to devices configured and adapted to give a fluid stream the appearance of being lighted. Different colors of light, such as those provided from LEDs, may be used to generate an aesthetically pleasing effect of flowing colored fluid. In some embodiments, the fluid illumination may be accomplished by a light source directed towards a fluid stream from an external angle, for example. Alternatively, the light source may be pointed in the direction of the fluid stream, lighting it substantially internally. In yet other embodiments, the fluid illumination may be enhanced with the employment of reflective surfaces that bounce light around and through the fluid stream. To increase the appearance of being lighted, the reflective fluid surface area may be increased by generating turbulent flow. In certain embodiments, turbulent flow is achieved with the use of a separator to separate a single fluid stream into a plurality of micro-streams.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending application Ser. No. 438,156, filed Jan. 31, 1974, now U.S. Pat. No. 3,948,894.
BACKGROUND OF THE INVENTION
This invention relates to anti-inflammatory 5,6-diaryl-1,2,4-triazines. More particularly, this invention relates to topically-active anti-inflammatory 5,6-diaryl-1,2,4-triazines.
Inflammation is an essentially protective and normal response to injury, although the etiology and pathogenesis of many inflammatory conditions remain obscure. In general, anti-inflammatory agents are employed primarily to relieve the symptoms of inflammation. In such symptomatic therapy, topically-applied anti-inflammatory agents present special problems. Inflammatory conditions calling for the topical application of an anti-inflammatory agent are almost exclusively treated with steroids. Topically-applied steroids, however, may carry considerable systemic toxicity. Thus, the need continues for safer, better tolerated topically-active anti-inflammatory agents.
SUMMARY OF THE INVENTION
In accordance with the present invention, 5,6-diaryl-1,2,4-triazines are provided having the formula, ##STR2## wherein R is hydrogen or --(X) n R 1 , in which X is either O or S, n is an integer which is either 0 or 1, and R 1 is C 1 -C 8 alkyl, C 7 -C 8 aralkyl, C 3 -C 8 cycloalkyl, or C 4 -C 8 (cycloalkyl)alkyl; and R 2 and R 3 independently are halo, C 1 -C 3 alkyl, C 1 -C 3 alkoxy or di(C 1 -C 3 alkyl)amino, with the proviso that at least one of R 2 and R 3 is halo or C 1 -C 3 alkyl; and the pharmaceutically-acceptable acid addition salts of basic members thereof.
The compounds of the present invention are useful as anti-inflammatory agents. In particular, all of such compounds are especially useful as topically-active anti-inflammatory agents in warm-blooded mammals, such as guinea pigs, mice, rats, dogs, monkeys, humans, and the like. In addition, various compounds wherein X is O or S and n is 1 are useful as intermediates in the preparation of anti-inflammatory 3-amino-5,6-diaryl-1,2,4-triazines which are disclosed and claimed in copending and commonly-assigned application Ser. No. 438,156, filed Jan. 31, 1974, by William B. Lacefield, now U.S. Pat. No. 3,948,894.
DETAILED DESCRIPTION OF THE INVENTION
The term C 1 -C 8 alkyl includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, 1-methylbutyl, 1-ethylpropyl, neopentyl, tert-pentyl, 1,2-dimethylpropyl, hexyl, isohexyl, 2-ethylbutyl, 1-ethyl-1-methylpropyl, heptyl, 2-ethyl-1-methylbutyl, 2,4-dimethylpentyl, octyl, 2-ethylhexyl, 1,1-diethylbutyl, and the like.
The term C 7 -C 8 aralkyl includes benzyl, 2-phenylethyl, p-methylbenzyl, m-methylbenzyl, o-methylbenzyl, and the like.
The term C 3 -C 8 cycloalkyl includes cyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-ethyl-3-methylcyclobutyl, cyclopentyl, 3-isopropylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2,5-dimethylcyclohexyl, cycloheptyl, 5-methylcycloheptyl, cyclooctyl, and the like.
The term C 4 -C 8 (cycloalkyl)alkyl includes cyclopropylmethyl, 3-cyclopropyl-2-methylbutyl, 3-(2-methylcyclobutyl)propyl, 2-cyclopentylethyl, 4-methylcyclohexylmethyl, cycloheptylmethyl, and the like.
The term C 1 -C 3 alkoxy includes methoxy, ethoxy, propoxy, and isopropoxy. The term C 1 -C 3 alkyl includes methyl, ethyl, propyl, and isopropyl. The term halo includes fluoro, chloro, bromo, and iodo.
Illustrative of the triazine compounds which are provided by the present invention are the following:
5,6-bis(4-fluorophenyl)-1,2,4-triazine,
5,6-bis(4-fluorophenyl)-3-methyl-1,2,4-triazine,
5,6-bis(4-fluorophenyl)-3-methoxy-1,2,4-triazine,
5,6-bis(4-fluorophenyl)-3-methylthio-1,2,4-triazine,
5,6-bis(4-methylphenyl)-1,2,4-triazine,
3-methyl-5,6-bis(4-methylphenyl)-1,2,4-triazine,
3-methoxy-5,6-bis(4-methylphenyl)-1,2,4-triazine,
5,6 -bis(4-methylphenyl)-3-methylthio-1,2,4-triazine,
6-(4-bromophenyl)-5-(4-iodophenyl)-1,2,4-triazine,
5-(4-ethylphenyl)-6-(4-propylphenyl)-1,2,4-triazine,
6-(4-fluorophenyl)-5-(4-methylphenyl)-1,2,4-triazine,
5-(4-methoxyphenyl)-6-(4-methylphenyl)-1,2,4-triazine,
5-(4-diethylaminophenyl)-6-(4-fluorophenyl)-1,2,4-triazine,
5-(4-fluorophenyl)-3-methyl-6-(4-methylphenyl)-1,2,4-triazine,
6-(4-fluorophenyl)-3-methoxy-5-(4-methylphenyl)-1,2,4-triazine,
5-(4-methoxyphenyl)-6-(4-methylphenyl)-3-methyl-thio-1,2,4-triazine,
6-(4-dimethylaminophenyl)-3-methyl-5-(4-methylphenyl)-1,2,4-triazine,
5-(4-dimethylaminophenyl)-6-(4-fluorophenyl)-3-methoxy-1,2,4-triazine,
5-(4-chlorophenyl)-6-(4-fluorophenyl)-3-methyl-1,2,4-triazine,
6-(4-chlorophenyl)-3-neopentyloxy-5-(4-propylphenyl)-1,2,4-triazine,
3-(2,3-dimethylpentylthio)-5-(4-ethylphenyl)-6-(4-isopropoxyphenyl)-1,2,4-triazine,
3-benzyl-5-(4-methylphenyl)-6-(4-propylphenyl)-1,2,4-triazine,
6-(4-dimethylaminophenyl)-5-(4-isopropylphenyl)-3-(p-methylbenzyloxy)-1,2,4-triazine,
3-cyclobutyl-5-(4-ethoxyphenyl)-6-(4-ethylphenyl)-1,2,4-triazine,
3-cyclopropyloxy-6-(4-dipropylaminophenyl)-5-(4-fluorophenyl)-1,2,4-triazine,
5,6-bis(4-fluorophenyl)-3-(3-methylcyclohexylthio)-1,2,4-triazine,
5,6-bis(4-ethylphenyl)-3-[2-(3-methylcyclopentyl)-ethyl]-1,2,4-triazine,
3-cyclobutylmethoxy-5-(4-diethylaminophenyl)-6-(4-methylphenyl)-1,2,4-triazine,
3-cyclopropylmethylthio-6-(4-fluorophenyl)-5-(4-propylphenyl)-1,2,4-triazine, and the like,
and the pharmaceutically-acceptable acid addition salts of the basic triazines.
The preferred triazines are those wherein at least one of R 2 and R 3 in the above-defined formula is fluoro or methyl. More preferably, R 2 and R 3 will be the same, and most preferably are fluoro or methyl. With respect to the substituent in the 3-position, the preferred groups are C 1 -C 8 alkyl (R is --(X) n R 1 , n is 0, and R 1 is C 1 -C 8 alkyl), C 1 -C 8 alkoxy (R is --(X) n R 1 , n is 1, X is O, and R 1 is C 1 -C 8 alkyl), and C 1 -C 8 alkylthio (R is --(X) n R 1 , n is 1, X is S, and R 1 is C 1 -C 8 alkyl). More preferably, the 3-substituent is C 1 -C 8 alkyl or C 1 -C 8 alkoxy. Most preferably, the 3-substituent is C 1 -C 3 alkyl or C 1 -C 3 alkoxy.
Examples of such preferred, more preferred, and most preferred triazines are included in the above list of illustrative triazines.
The compounds of the present invention are prepared by a variety of methods known to those having ordinary skill in the art. Starting materials and intermediates also are prepared by known methods. The preparation of 5,6-diaryl-1,2,4-triazines is described generally by J. G. Erickson in "The 1,2,3- and 1,2,4-Triazines, Tetrazines and Pentazines," The Chemistry of Heterocyclic Compounds, Vol. 10, Interscience Publishers, Inc., New York, N.Y., 1956, Chapter II, pp. 44-84. The 5,6-diaryl-1,2,4-triazines which are unsubstituted in the 3-position can be prepared by the catalytic reduction of the corresponding 3chlorotriazines.
The specific procedure employed to prepare a given 3-substituted-5,6-diaryl-1,2,4-triazine in part is dependent upon the substituent in the 3-position. For example, 3-alkyl-, 3-aralkyl-, 3-cycloalkyl-, and 3-(cycloalkyl)alkyl-5,6-diaryl-1,2,4-triazines can be prepared directly by the cyclization of acylhydrazones of α-diketones by ammonium acetate in hot acetic acid under controlled conditions; see, e.g., C. M. Atkinson and H. D. Cossey, J. Chem. Soc., 1962, 1805 [Chem. Abstr., 57:4662i (1962)]. Such triazines also can be prepared from 3-chloro-5,6-diaryl-1,2,4-triazines by the procedure of E. C. Taylor and S. F. Martin [J. Amer. Chem. Soc., 94, 2874 (1972)] which involves the nucleophilic displacement of chlorine by a Wittig reagent which may be generated in situ from an alkyl-, aralkyl-, cycloalkyl-, or (cycloalkyl)alkyltriarylphosphonium halide.
3-Chloro-5,6-diaryl-1,2,4-triazines also can be employed to prepare the 3-alkoxy, 3-aralkoxy-, 3-cycloalkoxy-, 3-(cycloalkyl)alkoxy-, 3-alkylthio-, 3-aralkylthio-, 3-cycloalkylthio-, and 3-(cycloalkyl)alkylthio-5,6-diaryl-1,2,4-triazines via the nucleophilic displacement of chlorine by the appropriate alcohol or thiol. The 3-alkylthio-, 3-aralkylthio-, 3-cycloalkylthio-, and 3-(cycloalkyl)alkylthio- compounds can be converted to the 3-alkoxy-, 3-aralkoxy-, 3-cycloalkoxy-, and 3-(cycloalkyl)alkoxy-5,6-diaryl-1,2,4-triazines, again via nucleophilic displacement by the appropriate alcohol. The 3-alkylthio-, 3-aralkylthio-, 3-cycloalkylthio, and 3-(cycloalkyl)alkylthiotriazines in many cases can be prepared by treating the appropriate 3-mercapto-5,6-diaryl-1,2,4-triazine with the appropriate hydrocarbyl halide in the presence of base, particularly when the hydrocarbyl halide is primary or secondary.
3-Chloro-5,6-diaryl-1,2,4-triazines are readily obtained by treating the appropriate 3-hydroxytriazine with phosphorus oxychloride. 3-Hydroxy- and 3-mercapto-5,6-diaryl-1,2,4-triazines in turn can be prepared by condensing an appropriate benzil with semicarbazide or thiosemicarbazide, respectively.
The required benzils are prepared by the oxidation of the corresponding benzoins with copper sulfate in pyridine; see H. T. Clarke and E. E. Driger, Org. Synthesis, Coll. Vol. I, 87 (1941). The benzoins are prepared by the condensation of aromatic aldehydes with cyanide ion; see W. S. Ide and J. S. Buck, Org. Reactions, 4, 269 (1948).
Another approach to the compounds of the present invention involves the use of benzils having substituents which can be displaced to give the desired R 2 or R 3 substituent. For example, the halogen on the phenyl ring at the 5-position in 5-(4-halophenyl)-6-aryl-1,2,4-triazines can be displaced with an alcohol or a dialkylamine to give the corresponding 5-(4-alkoxyphenyl)- or 5-(4-dialkylaminophenyl)- compound, respectively.
The use of two different aromatic aldehydes in the benzoin synthesis leads to unsymmetrical benzils. That is, in a benzil of the formula, ##STR3## wherein R 2 and R 3 are as described hereinbefore, R 2 and R 3 are different. The use of an unsymmetrical benzil may result in the preparation of a mixture of triazine isomers. For example, the condensation of 4-dimethylamino-4'-methoxybenzil with thiosemicarbazide gives a mixture of 5-(4-dimethylaminophenyl)-6-(4-methoxyphenyl)-1,2,4-triazine-3-thiol and 6-(4-dimethylaminophenyl)-5-(4-methoxyphenyl)-1,2,4-triazine-3-thiol.
It will be recognized by those skilled in the art that mixtures of triazine isomers are separable by known methods, such as fractional crystallization and chromatography. The isomer separation may be effected upon intermediate mixtures or delayed until the final product stage.
Certain of the 5,6-diaryl-1,2,4-triazines described herein are sufficiently basic to form acid addition salts, especially when the triazine contains a dialkylamino group on a phenyl ring. "Pharmaceutically-acceptable" acid addition salts are well known to those skilled in the art and in general are formed by reacting in a mutual solvent a stoichiometric amount of a suitable acid with a basic triazine. Such salts should not be substantially more toxic to warm-blooded animals than the triazines. While the choice of a salt-forming acid is not critical, in some instances a particular acid may result in a salt having special advantages, such as ready solubility, ease of crystallization, and the like. Representative and suitable acids include, among others, the following: hydrochloric, hydrobromic, hydriodic, sulfuric, nitric, phosphoric, methanesulfonic, p-toluenesulfonic, and the like.
A modification of the method of Winder was used to measure the anti-inflammatory activities of the compounds of the present invention; see C. V. Winder et al., Arch. Int. Pharmacodyn., 116, 261 (1958). Albino guinea pigs of either sex, weighing 225-300 grams, were shaved on the back and chemically depilated (Nair.sup.® Lotion Hair Remover, Carter Products, N.Y., N.Y.) 18-20 hours before exposure to ultraviolet light. The animals, in groups of four and bearing identifying ear tags, were treated by applying to an area of skin of about 12 cm. 2 a solution of test compound dissolved in 0.1 cc. of ethanol. The control treatment consisted of administering only the drug vehicle, ethanol, to a group of four animals. Groups of four animals each were given different treatment levels of test compound to obtain dose responses. Random order and blind administration of the test compounds were employed; drug identification was not made until after all animals were graded. Immediately prior to drug application, the animals were exposed in groups of four to a high-intensity ultraviolet light for a measured period of time (usually 4-7 seconds). The ultraviolet light source, a Hanovia Lamp (Kroymayer-Model 10), was placed in contact with the skin of the animal's back. A gummed notebook paper reinforcement was affixed to the lamp lens to provide an unexposed area of contrast for grading the erythema. Beginning one hour after exposure and thereafter at half-hour intervals for another 11/2 hours, the degree of resulting erythema was graded by an arbiturary scoring system based upon the degree of contrast and redness formed. Anti-inflammatory agents delay the development of the erythema and usually have their greatest effect at the initial grading periods. The scores were, therefore, weighted by factors of 4, 3, 2, and 1 at the 1.0, 1.5, 2.0, and 2.5 hour scoring times, respectively. The erythema was graded as follows:
______________________________________Erythema Scoring SystemScore Appearance of Exposed Area______________________________________0 No redness and no contrast1 Slight redness with a faint reinforcement outline2 Slight to moderate redness with a distinct outline3 Marked redness with a distinct circular outline______________________________________
Total scores from each treatment group of four guinea pigs were compared to the control treatment, and the percent inhibition was calculated as follows: ##EQU1##
A dose-response graph is obtained by plotting dose versus the average percent inhibition of each treatment group of four guinea pigs. The dose (ED 50 ) in micrograms per 12 cm. 2 (mcg./12 cm. 2 ) which produces a 50% inhibition of the erythemic response for the particular compound tested is obtained by extrapolation. In general, the 5,6-diaryl-1,2,4-triazines of the present invention result in at least about 20 percent inhibition at dose levels below about 10 3 mcg./12cm. 2 . For example, 3-methoxy-5,6-bis(4-methylphenyl)-1,2,4-triazine has an ED 50 of 20.5 mcg./12cm. 2 , and 5,6-bis(4-fluorophenyl)-3-methylthio-1,2,4-triazine has an ED 50 of 13 mcg./12cm. 2 .
The toxicities of representative compounds of the present invention, determined as the dose (LD 50 ) in milligrams per kilogram (mg./kg.) of animal body weight which is lethal to 50 percent of mice treated orally, typically are greater than about 1000 mg./kg., and in some cases are greater than about 1500 mg./kg.
In the utilization of the compounds of this invention, one (or more) of the anti-inflammatory triazines is topically administered to a warm-blooded mammal in an amount sufficient to provide at least about 1 mcg./12 cm. 2 ; such administration can be repeated periodically as needed. Because of the relatively low order of toxicity of such triazines, the maximum level of application is limited only by the esthetics of the mode of administration. As a practical matter, however, such triazines normally need not be administered at a level much above about 10 3 mcg./12 cm. 2 , although levels of about 10 5 mcg./12 cm. 2 or higher can be employed, if desired.
The topical administration of the anti-inflammatory compounds can be made according to any of the well known prior art procedures. Thus, such administration can utilize aerosols, creams, emulsions, lotions, ointments, solutions, and the like. In each case, the compounds to be employed are utilized in combination with one or more adjuvants suited to the particular mode of application. For example, ointments and solutions for topical administration can be formulated with any of a number of pharmaceutically-acceptable carriers, including ethanol, animal and vegetable oils, mixtures of waxes, solid and liquid hydrocarbons, glycols, and the like. Thus, a typical ointment composition comprises the following ingredients per gram of ointment:
______________________________________ mg.Triazine 0.1 - 100Polyethylene glycol 300 450 - 700 (N.F.)Polyethylene glycol 4000 300 - 450 (U.S.P.)______________________________________
The concentration of the anti-inflammatory triazine in the final topical preparation is not critical. In general, such concentration can range from about 0.001 percent to about 50 percent (w/w or w/v), or higher.
The following examples further illustrate the preparations of the compounds of the present invention.
EXAMPLE 1
Preparation of 5,6-Bis(4-fluorophenyl)-3-methylthio-1,2,4-triazine
(A) 5,6-Bis(4-fluorophenyl)-3-mercapto-1,2,4-triazine.
A solution of 80 g. of 4,4'-difluorobenzil in 400 ml. of ethanol was heated to reflux. Water then was added to the point of incipient turbidity, followed by the addition of 80 g. of thiosemicarbazide and 96 g. of sodium acetate. The reaction mixture was heated at reflux for one hour. Water again was added to the reaction mixture to the point of incipient turbidity. Sodium hydroxide, 80 g., then was added gradually to the reaction mixture, which then was heated at reflux for 1 hour. The reaction mixture was poured into a 3-fold volume of ice water and aqueous hydrochloric acid was added until the mixture was strongly acidic. The solid which precipitated was isolated by filtration and recrystallized from acetic acid to give 57.5 g. of 5,6-bis(4-fluorophenyl)-3-mercapto-1,2,4-triazine, m.p. about 180°-182° C.
Analysis: C 15 H 9 F 2 N 3 S. Calc: C, 59.79; H, 3.01; N, 13.95; Found: C, 59.96; H, 3.12; N, 14.05.
(B) 5,6-Bis(4-fluorophenyl)-3-methylthio-1,2,4-triazine.
To a solution of 26.5 g. of 5,6-bis(4-fluorophenyl)-3-mercapto-1,2,4-triazine and 4 g. of sodium hydroxide in 300 ml. of ethanol was added 24.2 g. of methyl iodide. The mixture was agitated at ambient temperature. The precipitate which formed was isolated by filtration and recrystallized from ethanol, giving 14 g. of 5,6-bis(4-fluorophenyl)-3-methylthio-1,2,4-triazine, m.p. about 134°-136° C.
Analysis: C 16 H 11 F 2 N 3 S; Calc: C, 60.94; H, 3.52; F, 12.05; N, 13.33; Found: C, 60.72; H, 3.48; F, 11.92; N, 13.04.
EXAMPLE 2
Preparation of 5-(4-Dimethylaminophenyl)-6-(4-fluorophenyl)-3-methylthio-1,2,4-triazine
(A) 5-(4-Dimethylaminophenyl)-6-(4-fluorophenyl)-3-Mercapto-1,2,4-triazine.
To a solution of 8.1 g. of 4-dimethylamino-4'-fluorobenzil in 65 ml. of acetic acid was added 3.3 g. of thiosemicarbazide. The reaction mixture then was heated at reflux for three hours. The solid which precipitated was isolated by filtration, washed successively with ethanol and water, and dried, giving 4.3 g. of 5-(4-dimethylaminophenyl)-6-(4-fluorophenyl)-3-mercapto-1,2,4-triazine, m.p. about 262°-264° C.
Analysis: C 17 H 15 FN 4 S; Calc: C, 62.57; H, 4.63; F, 5.82; N, 17.17; Found: C, 62.83; H, 4.73; F, 5.70; N, 17.29.
(B) 5-(4-Dimethylaminophenyl)-6-(4-fluorophenyl)-3-methylthio-1,2,4-triazine.
To a solution of 0.48 g. of sodium hydroxide in 100 ml. of ethanol was added 4 g. of 5-(4-dimethylaminophenyl)-6-(4-fluorophenyl)-3-mercapto-1,2,4-triazine. To the resulting solution was added, with agitation, 2.1 g. of methyl iodide. The precipitate which formed was isolated by filtration and recrystallized from ethanol to give 2.9 g. of 5-(4-dimethylaminophenyl)-6-(4-fluorophenyl)-3-methylthio-1,2,4-triazine, m.p. about 144°-146° C.
Analysis: C 18 H 17 FN 4 S; Calc: C, 63.51; H, 5.03; N, 16.46; S, 9.42; Found: C, 63.22; H, 5.30; N, 16.24; S, 9.23.
EXAMPLE 3
Preparation of 5,6-Bis(4-methylphenyl)-3-methylthio-1,2,4-triazine
(A) 3-Mercapto-5,6-bis(4-methylphenyl)-1,2,4-triazine.
To a solution of 85 g. of 4,4'-dimethylbenzil in 360 ml. of acetic acid heated to about 80°-100° C. was added 35.5 g. of thiosemicarbazide, portionwise, over a 10-minute period. The reaction mixture was heated at reflux for 2 hours. The reaction mixture was cooled and diluted with 500 ml. of water. The solid which precipitated was isolated by filtration, washed with water, and recrystallized from ethanol to give 22 g. of 3-mercapto-5,6-bis(4-methylphenyl)-1,2,4-triazine, m.p. about 220°-223° C.
Analysis: C 17 H 15 N 3 S; Calc: C, 69.60; H, 5.15; N, 14.32; Found: C, 69.32; H, 5.36; N, 14.60.
(B) 5,6-Bis(4-methylphenyl)-3-methylthio-1,2,4-triazine.
To a solution of 24 g. sodium hydroxide in about one liter of ethanol was added 146.5 g. of 3-mercapto-5,6-bis(4-methylphenyl)-1,2,4-triazine. To the resulting solution was added 88.2 g. of methyl iodide. The reaction mixture was agitated overnight at ambient temperature. The solid which precipitated was isolated by filtration and washed with ethanol; the solid was recrystallized from ethanol to give 101.1 g. of 5,6-bis(4-methylphenyl)-3-methylthio-1,2,4-triazine, m.p. about 170°-172° C.
Analysis: C 18 H 17 N 3 S; Calc: C, 70.33; H, 5.57; N, 13.67; Found: C, 70.25; H, 5.78; N, 13.72.
EXAMPLE 4
Preparation of 3-Methoxy-5,6-bis(4-methylphenyl)-1,2,4-triazine
A solution of sodium methoxide in methanol was prepared by reacting 5 g. of sodium with 350 ml. of methanol. To such solution was added 61.4 g. of 5,6-bis(4-methylphenyl)-3-methylthio-1,2,4-triazine. The reaction mixture was heated at reflux for 6 hours, then was allowed to stir overnight at ambient temperature. The reaction mixture was concentrated under reduced pressure and the residue was diluted with water. The insoluble solid was isolated by filtration and recrystallized from ethanol to give 3-methoxy-5,6-bis-(4-methylphenyl)-1,2,4-triazine, m.p. about 125°-128° C.
Analysis: C 18 H 17 N 3 O; Calc: C, 74.20; H, 5.88; N, 14.42; Found: C, 74.11; H, 5.83; N, 14.17.
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5,6-Diaryl-1,2,4-triazines, topically-active anti-inflammatory agents, having the formula, ##STR1## wherein R is hydrogen or --(X) n R 1 , in which X is either O or S, n is an integer which is either 0 or 1, and R 1 is C 1 -C 8 alkyl, C 7 -C 8 aralkyl, C 3 -C 8 cycloalkyl, or C 4 -C 8 (cycloalkyl)alkyl; and R 2 and R 3 independently are halo, C 1 -C 3 alkyl, C 1 -C 3 alkoxy, or di(C 1 -C 3 alkyl)amino, with the proviso that at least one of R 2 and R 3 is halo or C 1 -C 3 alkyl; and the pharmaceutically-acceptable acid addition salts of basic members thereof.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for preparing O-acetyl-L-serine by means of fermentation.
2. The Prior Art
Fermentative processes for preparing amino acids are nowadays commonplace. These processes are, in particular, methods for preparing representatives of the twenty proteinogenic amino acids which are highly relevant from the economic point of view, such as L-glutamic acid, L-lysine and L-threonine. However, there is an increasing number of reports of processes for preparing proteinogenic amino acids which command smaller markets in the range of from 1000 to 10,000 tons per year, such as L-phenylalamine and L-cysteine.
By contrast, scarcely any corresponding methods are known for preparing biosynthetic precursors of the twenty proteinogenic amino acids. However, it is precisely these precursors which can represent interesting products since they frequently possess chiral centers and can serve as building blocks for synthesizing pharmaceutical active compounds. For example, patent application WO 00/44923 describes the preparation of shikimic acid, which is an intermediate in the biosynthesis of aromatic amino acids. Another example is that of application EP 0994190 A2, which reports the use of fermentation to produce L-homoserine, which is a precursor of L-methionine.
O-Acetyl-L-serine is a biosynthetic precursor of L-cysteine. It is an amino acid in its own right and is formed in bacterial and plant metabolism by L-serine being acetylated at the hydroxyl function. This reaction is catalyzed by the enzyme serine O-acetyltransferase [EC 2.3.1.30], which is encoded by the cysE gene. In the cell, O-acetylserine is subjected to further reaction to form L-cysteine. In this reaction, the acetate function is replaced with a thiol function.
Difficulties with preparing o-acetyl-L-serine by fermentation result from the fact that the substance is very labile and isomerizes to N-acetyl-L-serine at pH values above 4.0. At a pH of 7.6, the rate of the reaction is 1%×min −1 (Tai et al., 1995, Biochemistry 34: 12311-12322). This means that no significant quantities of O-acetylserine can be detected under these conditions after a fermentation process which is usually conducted for at least one-and-a-half days. The isomerization reaction is irreversible and its rate increases still further as the pH increases. Because its amino function is blocked, N-acetyl-L-serine can no longer be used for peptide syntheses, in contrast to O-acetyl-L-serine.
Another difficulty is that the level of O-acetyl-L-serine in the cell is very low and is subject to powerful regulation. On the one hand, serine acetyltransferase is inhibited allosterically by L-cysteine, and no synthesis of O-acetyl-L-serine is consequently possible in the presence of μM concentrations of L-cysteine. On the other hand, the isomerization product N-acetyl-L-serine acts as an inducer of the sulfur regulon and thereby leads to the rapid reaction of O-acetyl-L-serine with sulfide to form L-cysteine.
Dassler et al. (2000, Mol. Microbiol. 36: 1101-1112) have reported that cells which overproduce the membrane protein YdeD (=Orf299) secrete L-cysteine, 2-methylthiazolidine-2,4-dicarboxylic acid and also O-acetyl-L-serine into the culture medium. However, it was possible to detect the O-acetyl-L-serine only in very small quantities, of 0.12 g/l, and then only in shaking flask experiments. On the other hand, only N-acetyl-L-serine was obtained in fermentation experiments which enable higher yields to be obtained as a result of improving the nutrient supply. The possibility has been discussed that O-acetyl-L-serine is sufficiently stable only at pH values of 4-5. However, this pH range is not suitable for a fermentative preparation due to the poor growth of neutrophilic bacteria such as Escherichia coli.
The fermentative preparation of N-acetyl-L-serine at pH 7.0 using Orf299 has also been described in patent application EP 0885962 Al. In this case, the orf299 gene (designated by SEQ.ID.NO:3 in the application) was combined with suitable cysE alleles. These alleles encoded serine acetyltransferases which were subject to less feedback inhibition by L-cysteine. This resulted in an increased production of O-acetyl-L-serine being achieved in the cell and ultimately in the accumulation of N-acetyl-L-serine due to the rapid isomerization.
Using cysE alleles which are subject to less feedback inhibition on their own, as described in application WO 97/15673, does not lead to the accumulation of O-acetyl-L-serine, either. While an increased formation of O-acetyl-serine is achieved intracellularly when this approach is used, only L-cysteine was detected extracellularly and was consequently within reach as a product.
A further serious difficulty when producing O-acetyl-L-serine is the fact, reported by Dassler et al. (2000, Mol. Microbiol. 36: 1101-1112), that overproduction of Orf299 leads to severe impairment of bacterial growth. This is due to the absence of induction of the sulfur regulon because of the intracellular deficiency of the inducer N-acetyl-L-serine.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a fermentative process which provides high yields of O-acetyl-L-serine despite the instability of O-acetyl-L-serine and the negative physiological consequences of efficiently exporting O-acetyl-L-serine from the cell.
This object is achieved by culturing, in a fermentation medium, a microorganism strain which is derived from a wild type and in which the endogenous formation of O-acetyl-L-serine and the efflux of O-acetyl-L-serine are increased as compared with the wild type, wherein the pH in the fermentation medium is adjusted to be within the range from 5.1 to 6.5.
It has unexpectedly and surprisingly been found:
that a microorganism strain which is characterized as described above secretes O-acetyl-L-serine in large quantities,
that O-acetyl-L-serine is sufficiently stable in the fermentation medium at pH values of from 5.1 to 6.5, and
that, at the same time, the abovementioned physiological problems of an o-acetyl-L-serine-secreting cell can to a large extent be remedied by supplying O-acetyl-L-serine in increased amounts using feedback-resistant cysE alleles.
The pH of the fermentation medium during fermentation is preferably in the pH range from 5.5 to 6.5; and a pH of from 5.5 to 6.0 is particularly preferred.
Microorganism strains which can be used in the process according to the invention are distinguished by the fact that they
exhibit an increased endogenous formation of O-acetyl-L-serine, and
exhibit an increased efflux of O-acetyl-L-serine.
Strains of this nature are known in the state of the art. An increased endogenous formation of O-acetyl-L-serine can be achieved by introducing modified cysE alleles, as described, for example, in
WO 97/15673 (hereby incorporated by reference) or
Nakamori S. et al., 1998, Appl. Env. Microbiol. 64: 1607-1611 (hereby incorporated by reference) or
Takagi H. et al., 1999, FEBS Lett. 452: 323-327 into a microorganism strain.
These cysE alleles encode serine O-acetyltransferases which are subject to a diminished feedback inhibition by cysteine. As a result, the formation of O-acetyl-L-serine is to a large extent uncoupled from the cysteine level in the cell.
An increased O-acetyl-L-serine efflux can be achieved by increasing the expression of an efflux gene whose gene product brings about the export of O-acetyl-L-serine.
The ydeD gene, which has been described by Dassler et al. (2000, Mol. Microbiol. 36: 1101-1112) and in EP 0885962 A1 (corresponds to the US application with the Ser. No. 09/097,759 (hereby incorporated by reference)) is a particularly preferred efflux gene of this nature.
The modified cysE alleles and/or the efflux gene may be present in the strain employed in single copies or else in increased copy number. They may be encoded chromosomally or be located on self-replicating elements, such as plasmids.
The expression of the genes can be increased, for example, by using suitable promoter systems which are known to a person skilled in the art.
In a preferred embodiment of the present invention, use is made of a microorganism which harbors a cysE allele and/or a ydeD gene, having a native promoter or the gapDH promoter, on a plasmid having a medium-range copy number. An example of such a construct is pACYC184-cysEX-GAPDH-ORF306, which is described in detail in EP 0885962 A1.
In principle, all microorganism strains which are accessible to genetic methods and which can be readily cultured in a fermentation process are suitable for preparing strains of this nature. Preference is given to using bacteria of the Enterobacteriaceae family. Particular preference is given to using organisms of the species Escherichia coli . The preparation of these strains is described in the abovementioned documents and is not part of the present invention.
Strains which are suitable for the process according to the invention are also suitable—as described in EP 0885962 A1 (corresponds to the U.S. Patent application having the Ser. No. 09/097,759 (herewith incorporated by reference))—for preparing cysteine and cysteine derivatives. However, in this case, an adequate supply of an inorganic sulfur source, such as sulfate or thiosulfate, is required in order to obtain optimum quantities of L-cysteine or one of its derivatives.
However, in the process according to the invention, no sulfur source is metered in during the fermentation since the further conversion of O-acetyl-L-serine into cysteine is unwanted. It is only necessary to ensure that an adequate quantity of a sulfur or S source (e.g. sulfate or thiosulfate) is present in the medium so as to cover the requirement of the cellular protein synthesis for cysteine. The adequate quantity in the nutrient medium is preferably from 5 to 50 mM sulfur.
The process according to the invention for preparing O-acetyl-L-serine using a microorganism strain is performed in a fermenter in a manner which is known per se but while setting unusually low pH values during the fermentation.
The microorganism strain is grown in the fermenter as a continuous culture, as a batch culture or, preferably, as a fed-batch culture. Particularly preferably, a carbon or C source is metered in continuously during the fermentation.
Preference is given to using sugar, sugar alcohols or organic acids as the C source. The C sources which are particularly preferably used in the process according to the invention are glucose, lactose or glycerol.
The C source is preferably metered in, in a form which ensures that the content in the fermenter during the fermentation is maintained in a range of 0.1-50 g/l. A range of 0.5-10 g/l is particularly preferred.
The nitrogen or N source which is preferably used in the process according to the invention is ammonia, ammonium salts or protein hydrolyzates. When ammonia is used as the correcting agent for maintaining a constant pH, this N source is then regularly fed in during the fermentation.
Other medium additives which may be added are salts of the elements phosphorus, chlorine, sodium, magnesium, nitrogen, potassium, calcium and iron. Trace amounts (i.e. in μM concentrations), of salts of the elements molybdenum, boron, cobalt, manganese, zinc and nickel, may also be added.
It is furthermore possible to add organic acids, or salts of these acids, (e.g. acetate or citrate), amino acids (e.g. isoleucine) and vitamins (e.g. B1, B6) to the medium.
Examples of complex nutrient sources which may be used are yeast extract, corn steep liquor, soybean meal and malt extract.
The incubation temperature is 15-45° C. A temperature of between 30 and 37° C. is preferred.
The fermentation is preferably carried out under aerobic growth conditions. Oxygen is fed into the fermenter using compressed air or pure oxygen.
Microorganisms which are fermented in accordance with the process of the present invention which has been described, secrete O-acetyl-L-serine into the culture medium with a high degree of efficiency over a fermentation period of from 1 to 3 days.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing. It is to be understood, however, that the drawing is designed as an illustration only and not as a definition of the limits of the invention.
In the drawing, FIG. 1 shows the total content of acetyl-serine versus time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples serve to further clarify the invention. The bacterial strain Escherichia coli W3110/pACYC184-cysEX-GAPDH-ORF306, which was used for carrying out the examples, was deposited, in accordance with the Budapest Treaty, in the DSMZ (Deutsche Sammlung für Mikrooganismen und Zellkulturen [German Collection of Microorganisms and Cell Cultures] GmbH, D-38142 Brunswick) under the number DSM 13495.
EXAMPLE 1
Isomerisation of O-acetyl-L-serine to N-Acetyl-L-serine
In order to gain a more accurate impression of the isomerization reaction under conditions approximating to those of fermentation, 0.9 g of O-acetyl-L-serine was introduced into 100 ml of fermentation medium (see Example 3). The pH was then adjusted to 7.0 using 25% ammonia and samples were withdrawn at various times while maintaining a reaction temperature of 32° C. These samples were analyzed by reversed phase HPLC performed on a LUNA 5μ C18(2) column, (Phenomenex, Aschaffenburg, Germany). Dilute phosphoric acid (0.1 ml of conc. phosphoric acid/l) was used as the eluent, at a flow rate of 0.5 ml/min. The results are shown in FIG. 1 .
EXAMPLE 2
Preliminary Culture of the Production Strain
As the preliminary culture for the fermentation, 20 ml of LB medium (10 g of tryptone/l, 5 g of yeast extract/l, 10 g of NaCl/l), which additionally contained 15 mg of tetracycline/l, were inoculated with the strain W3110/pACYC184-cysEX-GAPDH-ORF306 (described in EP 0885962 Al, corresponds to the U.S. Patent application having the Ser. No. 09/097759 (hereby incorporated by reference)) and incubated at 30° C. and 150 rpm in a shaker incubator. After seven hours, the whole mixture was transferred to 100 ml of SM1 medium (12 g of K 2 HPO 4 /l; 3 g of KH 2 PO 4 /l; 5 g of (NH 2 ) 2 SO 4 /l; 0.3 g of MgSO 4 ×7H 2 O/l; 0.015 g of CaCl 2 ×2H 2 O/l; 0.002 g of FeSO 4 ×7H 2 O/l; 1 g of Na 3 citrate×2H 2 O/l; 0.1 g of NaCl/l; 1 ml of trace element solution/l, with this solution consisting of 0.15 g of Na 2 MoO 4 ×2H 2 O; 2.5 g of Na 3 BO 3 /l; 0.7 g of CoCl 2 ×6H 2 O/l; 0.25 g of CuSO 4 ×5H 2 O/l; 1.6 g of MnCl 2 ×4H 2 O/l; 0.3 g of ZnSO 4 ×7H 2 O/l) which was supplemented with 5 g of glucose/l; 0.5 mg of vitamin B 1 /l and 15 mg of tetracycline/l. The subsequent incubation took place at 30° C. for 17 hours and at 150 rpm.
EXAMPLE 3
Preparation of o-acetyl-L-serine by Fermentation
The fermenter employed was a Biostat M appliance, which was supplied by Braun Biotech (Melsungen, Germany) and which has a maximum culture volume of 2 l. The fermenter, containing 900 ml of fermentation medium (15 g of glucose/l; 10 g of tryptone/l; 5 g of yeast extract/l; 5 g of (NH 4 ) 2 SO 4 /l; 1.5 g of KH 2 PO 4 /l; 0.5 g of NaCl/l; 0.3 g of MgSO 4 ×7H 2 O/l; 0.015 g of CaCl 2 ×2H 2 O/l; 0.075 g of FeSO 4 ×7H 2 O/l; 1 g of Na 2 citrate×2H 2 O/l and 1 ml of trace element solution, see above,/l, 5 mg of vitamin B1/l and 15 mg of tetracycline/l, adjusted to pH 6.0 with 25% ammonia) was inoculated with the preliminary culture described in Example 2) optical density at 600 nm of approx. 3). During the fermentation, the temperature was set to 32° C. and the pH was kept constant at a value of 6.0 by metering in 25% ammonia. The culture was gassed with sterilized compressed air at the rate of 1.5 vol/vol/min and stirred using a stirrer speed of 200 rpm. After the oxygen saturation had fallen to value of 50%, the rotational speed of the stirrer was increased, by way of a controlling device, to a value of 1200 rpm in order to maintain 50% oxygen saturation (determined using a pO 2 probe calibrated to 100% saturation at 900 rpm). A 56% solution of glucose was metered in as soon as the glucose content in the fermenter, which was originally 15 g/l, had fallen to approx. 5-10 g/l. The feeding-in took place at a flow rate of 6-12 ml/h, with the glucose concentration in the fermenter being maintained constant at between 0.5 and 10 g/l. The glucose was determined using the glucose analyzer supplied by YSI (Yellow Springs, Ohio, USA). The fermentation lasted for 28 hours. After this time, samples were removed and the cells were separated off from the culture medium by centrifugation. The resulting culture supernatants were analyzed by reversed phase HPLC as described in Example 1. Table 1 shows the content of the main metabolic products which were achieved in the culture supernatant:
TABLE 1
Metabolite
Content [g/l]
O-acetyl-L-serine
9.0
N-acetyl-L-serine
4.2
2-methylthiazolidine-2,4-
1.9
dicarboxylic acid
Similar values were obtained in the range from pH 6.5 to pH 5.5.
Accordingly, while only several embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
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A process is provided for the fermentative preparation of O-acetyl-L-serine. A microorganism strain, which is derived from a wild type and which exhibits an increased endogenous formation of O-acetyl-L-serine and an increased efflux of O-acetyl-L-serine as compared with the wild type, is cultured in a fermentation medium. A pH in the range from 5.1 to 6.5 is set in the fermentation medium.
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BACKGROUND OF THE INVENTION
The present invention relates generally to containers, and more particularly to containers which are adapted for stacking in vertically aligned adjacency.
The container herein proposed is useful in the collection, storage and transport of a variety of bulk materials, but is particularly suited for use in handling materials which exhibit potentially dangerous or offensive properties. Specifically, the present invention is adapted for use in handling infectious medical waste. Such waste, when not properly isolated from the public may lead to a health hazard. The odor or appearance of medical waste may also be offensive if not properly contained. When handling such a material, containers may serve to isolate the material from the public, curtailing problems associated with its potentially dangerous or offensive properties.
Containers also serve to maximize the use of available space during transport or storage of bulk materials, keeping such materials in an orderly arrangement. Toward this end, containers have been developed which are stackable, one on top of the other. Such stackability has generally been achieved by simply providing the containers with substantially flat top and bottom surfaces, the containers thus being stackable by placing the bottom of one container on the top of another.
One problem with containers of the foregoing type, however, concerns the difficulties associated with aligning the containers upon vertical stacking of the same. Vertical alignment of the containers is often left to the eye of an individual and is therefore rarely precise. An upper container may, for example, be placed atop a lower container in an offset position, leaving a portion of the upper container hanging over the edge of the lower container. This offset may, in turn, result in an unstable stack, and consequently in the spilling or dumping of the containers.
Use of known stackable containers may also result in an unstable container stack due to the limited opposition to relative transverse motion of such containers when in stacked arrangement. Prior art containers have addressed this problem by providing latch mechanism by which containers may be secured to one another. Such an arrangement, however, requires an additional step when stacking or unstacking containers and is therefore undesirable.
The problems associated with stacking containers are compounded where the containers to be stacked are wheeled. Such containers not only present a problem relating to the compatibility of adjacent surfaces, but also with respect to the opposition to relative transverse motion.
Known wheeled containers, when stacked, would simply roll off the container therebelow. Another problem with prior art stackable containers relates to the ability of such containers to support the weight of the containers stacked thereon. In order to support above-stacked containers, prior art containers have commonly been constructed of sturdy materials such as steel. Alternatively, containers have been formed with lids which are thick enough to support the above-stacked containers. Prior art containers have thus been relatively heavy, adding to the cost and the difficulty in handling the containers.
It is therefore desired to provide an improved container adapted for stacking in aligned vertical adjacency with similar containers.
SUMMARY OF THE INVENTION
The invented container includes a first exterior surface portion having a target region projecting outwardly therefrom and a second exterior surface portion having an alignment region. The alignment region is formed such that, upon vertically adjacent positioning of a similar container, without offset, the alignment region and target regions cooperatively interfit to oppose relative transverse movement of the containers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a preferred embodiment of the invented container as viewed from an upper left position.
FIG. 2 is an isometric view of the container embodiment depicted in FIG. 1, the container being viewed from a lower left position.
FIG. 3 is a side view of plural containers of the type depicted in FIG. 1 the containers being arranged in an aligned vertical stack.
FIG. 4 is an end view of the container stack depicted in FIG. 3.
FIG. 5 is an enlarged, fragmentary side view of laterally adjacent containers of the type depicted in FIG. 1 illustrating contact between bumpers of such containers.
DETAILED DESCRIPTION OF THE INVENTION
As stated above, the present invention relates to containers which are adapted for plural arrangement in vertically aligned stacks. The containers are suitable for use in the collection, storage and transportation of a variety of materials, including bulk materials such as infectious waste. A preferred embodiment of the invented container has been depicted in the drawings, the device being indicated generally at 10.
Referring initially to FIGS. 1 and 2, it will be noted that container 10 includes a container body 12 having walls 18 and a floor 20. The walls and floor together define a cavity 14, such cavity being suitable for holding various bulk materials therein. Where a fluid-containing material such as infectious waste is to be held by the container, the floor may include a drain means (not shown), such drain means being adapted for selective release of fluid materials from the container's cavity. It should be evident that, although the depicted container body is generally right-parallelepiped-shaped, the body may be of any shape suitable for holding the to-be-handled material.
Upon inspection of FIG. it will be noted that container 10 also includes a lid 16, such lid being adapted for operative association with body 12. In the preferred embodiment of the invention, lid 16 is associated with the body via hinges (not shown), such hinges providing for the pivotal opening and closing of the lid. Lid 16 is thus selectively operable to open and close access to cavity 14. Preferably, where hazardous materials are to be held, within the container, body 12 and lid 16 come together to form a substantially hermetic seal, protecting the public from exposure to such materials. Those skilled in the art will recognize that such a seal may be provided by placement of a rubber-like O-ring (not shown) at the intersection between the lid and the body.
In the preferred embodiment, cavity 14 has a relatively large capacity, providing approximately 35 cubic feet of storage space. The container is reusable being composed of a fiberglass material having fire-retardant properties in order to ensure the safe temporary storage and transportation of infectious waste.
Referring specifically to FIG. 1, it will be noted that lid 16 includes what is referred to as a first exterior surface portion 22. In the preferred embodiment, surface portion 22 is the upper surface of the container lid. As shown, the surface portion includes a target region 24 which projects outwardly therefrom. The target region, in turn, includes a trapezoidal subregion 26 and a pair of pedestal subregions 28. Trapezoidal subregion 26 has a pair of oppositely facing, converging, inclined glide surfaces 27 (only one of which is visible in FIG. 1, but both of which are shown in FIG. 3). As will be further explained below, target region 24 is suited for use in urging the next-above-stacked container into vertical alignment with container 10.
Turning now to FIG. 2, it will be noted that body 12 includes a bottom surface 20, such surface being referred to as a second exterior surface portion. As shown, the second exterior surface portion has a structure 30 secured thereto. Structure 30 serves as an alignment region, the structure being adapted for cooperative interfitment with a target region of the next-below container. Structure 30 is made up of an elongate first member 32 and a pair of elongate second members 34, the second members extending transversely to first member 32.
Member 32 extends along floor 20, spanning the length of container 10. A channel 36 is defined in member 32, such channel being adapted for slidable receipt of connectors such as a male connector 38 and a matable female connector 40. Using such connectors, containers may be arranged in container trains such that they may be towed end-to-end behind a transport vehicle. Such trains may, in fact, be arranged using container stacks, providing for improved mobility for container groups.
As shown, each of the transversely disposed second members 34 defines a passageway as shown at 42. In the preferred embodiment, members 34 are parallelly spaced, extending orthoganally to member 32 to act as fork-lift compatible receivers so that the container may be lifted into a stacked position or into a vehicle for transportation. To insure stability, members 34 are secured to body 12 by spacer elements such as at 44.
Wheel assemblies 46 are secured to surface 20, providing for improved mobility of the containers.
Turning now to FIGS. 3 and 4, it will be noted that containers of the type depicted in FIGS. 1 and 2 may be stacked by simple vertical positioning of a second container above a first container. The alignment structure of a like second container 10' engages the target region of first container 10 to provide for aligned vertical stacking of the containers. As is best shown in FIG. 3, pedestal subregions 28 are dimensioned fore and aft of trapezoidal subregion 26 such that the bottom surfaces of fork-lift receivers 34' on the next-above-stacked container engage the upper surface of the pedestal subregions of the first container.
The target region provides, upon placement of container 10' above container 10 within a predetermined range of relative fore and aft positions, for the urging of the containers into vertical alignment with respect to the length of the containers (left to right in FIG. 3). Such urging is accomplished via translational engagement of either of the two fork-lift receivers 34' with a corresponding glide surface 27. Upon such engagement, the fork-lift receiver glides along the glide surface under the weight of the above-stacked container toward seating on pedestal subregion 28. It is important to note that glide surface 27 is inclined, the longitudinal extent of such incline (along the length of the container) defining the predetermined range in which placement of vertically adjacent containers will be self-guided into proper vertical alignment.
Referring for a moment to FIG. 4, it will be noted that member 32' is, upon vertical stacking of containers 10 and 10', seated within a channel or groove 48 formed in trapezoidal subregion 26. Groove 48 is defined in part by a pair of facing counter-inclined groove surfaces. Due to the incline of the surfaces defining groove 48, aligned vertical stacking of container 10' atop container 10 may be accomplished with respect to the width of the containers (left to right in FIG. 4). Such alignment is achieved where container 10' has been placed above container 10 within the limits of a predetermined transverse range. Placement of second container 10' atop first container 10 such that member 32' engages either of the two counter-inclined surfaces of groove 48 will therefore result in a sliding movement of member 32' along such surface into aligned seating within groove 48 of first container 10.
Container 10' is therefore placed in substantially non-offset vertical alignment with respect to container 10 therebelow.
Any tendency of the upper container to shift from side-to-side (left or right in FIG. 4) is opposed by engagement of member 32' with either side of groove 48. Similarly, fork-lift receivers 34' of the container 10' capture the lower container's trapezoidal subregion 26 therebetween, opposing any tendency of the upper container to shift fore or aft (left or right in FIG. 3). By virtue of opposition to relative movement in orthogonal directions, all relative transverse movement of the containers is opposed.
Where, as in the preferred embodiment, the containers are wheeled, the wheels of the stacked container are dimensioned, relative to the various upward extents of target region 24 and the various downward extents of members 32', 34' to rest on the lid of the next-below container, further opposing relative movement of the containers.
Those skilled in the art will recognize that the vertically extending surfaces on lid 16 provide truss-like support for the above-stacked containers which may weigh hundreds of pounds. It should also be noted that the stacked container engages the lower container in a way that encourages relatively lid-extensive weight distribution, improving stability of container stacks.
With reference to FIGS. 1-4 inclusive, it will be noted that the container of the presently described embodiment includes a bumper 50 extending around an upper perimeter near lid 16. As best shown in FIG. 5, bumper 50 extends outwardly from body 12, providing an abutment region to contact other objects such as walls or other containers. Bumper 50 includes a substantially vertical contact surface 52 adapted for contacting an adjacent container's bumper 50'. The upper-most portion of the bumper is inclined slide surface as shown at 54, the bumper having a generally wedge-shaped cross-section. As shown, the bumper has a height which is at least twice the bumper's thickness, thereby providing a substantial, vertical extent along which an adjacent container's bumper may make momentary contact, but will tend advantageously to slide down rather than to remain "hiked up".
Such a bumper is particularly useful where, as is commonly the practice, containers are arranged in close proximity to one another. Under such conditions, bumpers of alternative construction may result in one bumper "hiking up" on another bumper. Where bumpers are designed in accordance with those shown in FIG. 5, a higher bumper is more likely (especially under the substantial weight of a container loaded to capacity) to slide down the inclined surface of an adjacent, lower bumper, leaving both containers resting on their respective support surfaces or bases, as indicated in FIG. 5.
The invention thus provides a unique stackable container, such container being adapted for cooperative self-seating, self-aligning engagement with a vertically adjacent like container.
Accordingly, while a preferred embodiment of the invention has been disclosed, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined by the claims.
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A mobile infectious waste container including a lid which is sealable to a container body. The container includes a target region projecting outwardly from the lid and an alignment region extending oppositely from the container's floor. Upon vertically adjacent positioning of a similar container, without offset, the alignment region and target regions cooperatively interfit to oppose relative transverse movement of the containers. The container includes a bumper which extends at least partially perimetrically thereabout. The bumper includes a substantially uniformly inclined contact surface and is dimensioned such that the bumper's height is at least twice the bumper's thickness.
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FIELD OF THE INVENTION
[0001] The present invention relates to chemical reactions which involve the chemical conversion of a first functional group in an organic feed substrate, in the presence of hydrogen, whereby the organic feed substrate comprises at least one further functional group containing a halogen atom other than fluorine. More particularly, the invention relates to the noble metal catalysed reductive amination of only the first functional group on the substrate while keeping the further functional group containing the halogen atom substantially untouched and present in the reaction product.
BACKGROUND OF THE INVENTION
[0002] The selective conversion of one functional group in a multifunctional feed substrate has been an area of continuous high interest throughout the chemical, pharmaceutical and agrochemical industry. In particular, halogen atoms are often incorporated next to other functional groups in active ingredients or in precursors of those active ingredients.
[0003] The objective of high selectivity has often been rather elusive, because most processes are prone to side reactions leading to significant amounts of byproducts. These side reactions are consuming valuable amounts of feed substrate, and the byproducts are often rather useless. Some of the byproducts may also be difficult to separate from the desired product. In cases where the desired product is an intermediate for the production of a further derivative, some of the byproducts may also be disturbing for further synthesis steps because they may be reactive in such downstream process step and may lead to undesired additional consumption of valuable raw materials and even to undesirable and/or unacceptable end product contamination.
[0004] Multi-step synthesis protocols of complex multifunctional chemicals more and more comprise catalytic conversion steps as these often outperform their stoichiometric alternatives with respect to atom efficiency and reduced waste generation. Reductive conversion steps with hydrogen gas as the reducing agent typically use metal based catalysts in order to proceed at rates of commercial interests.
[0005] Metals, however, often interfere with carbon-halogen bonds in organic compounds. Pd in particular is for instance capable of inserting into a carbon-halogen bond. Such behaviour is desired in its use as catalyst in so-called coupling reactions. Such reactions are often used as key steps in multi-step synthesis paths for complex organic compounds, such as active ingredients in pharmaceutical or agrochemical industry. In a coupling reaction, a halogen containing first fragment is coupled with a second fragment by means of a catalyst, in which the second fragment is coupled to the first fragment at the position where the halogen was originally located. The second fragment may be coupled via a large variety of functional groups, and different versions of such coupling reactions have often received specific names, such as the Heck coupling, which is using an olefin, the Sonogashira coupling, which is using an alkyne, the Suzuki coupling, which is using a boronic acid and the Stille coupling, which uses an alkyl tin group. This list is far from exhaustive, because many more different functional groups may possibly be used for such coupling.
[0006] Insertion of a metal such as Pd into a carbon-halogen bond in the presence of hydrogen but in the absence of a suitable fragment to couple usually results in the displacement of the halogen atom by a hydrogen atom and hence the loss of the halogen (X) as part of the substrate. Such hydrogenolysis reaction is especially enhanced in the presence of a base which may capture the liberated acid HX. This reaction may be used advantageously in some applications, such as environmental treatment of halogenated organic pollutants.
[0007] For the production of the halogenated fragments to be used in subsequent coupling reactions, or in case halogen atoms are required in the structure of the final product, the insertion of the metal catalyst into the carbon-halogen bond is not desired, as it usually leads to side reactions and associated material losses. Not all halogens are evenly sensitive for this dehalogenation side reaction. The risk for dehalogenation is particularly high with chlorine, bromine and iodine, and much lower with fluorine-containing substrates.
[0008] A variety of methods have therefore been attempted in order to increase the selectivity of metal catalysed reductive aminations of one functional group in the presence of one or more halogen atoms elsewhere in the substrate molecule, in particular for chlorine, bromine and iodine.
[0009] One method involves the addition of modifiers to the reaction mixture or working into alternative reaction media.
[0010] U.S. Pat. No. 5,011,996 for instance discloses in Example 14 a process for the reductive amination of ortho-chloro benzaldehyde with ammonia, in methanol, under 90 bar of nitrogen supplemented by hydrogen addition until completion of the hydrogen uptake. Methanol-moist Raney nickel was used as the catalyst and a small amount of bis-(2-hydroxyethyl) sulphide was added as a modifier. The reaction mixture contained 90.5% ortho-chloro-benzylamine as the prime product, together with 0.9% of benzylamine and 6.8% of ortho-chloro-benzyl alcohol.
[0011] U.S. Pat. No. 6,429,335 B1 discloses in Example 1 also a process for the reductive amination of ortho-chloro benzaldehyde with ammonia, now under 140 bar of hydrogen using Raney nickel or Raney cobalt, to produce the primary amine ortho-chlorobenzylamine. This process operates in the presence of an amount of disodium tetraborate decahydrate (borax), optionally together with a small amount of bis(hydroxyethyl) sulphide, and obtains a product selectivity of at most 95.87% wt. The main byproduct is 3.19% wt of ortho-chloro-benzyl alcohol, and only 0.1% wt of benzylamine was found.
[0012] WO 2014/135508 A1 and EP 2774911 A1 disclose a process for the production of ortho-chloro-N,N-dimethylbenzylamine by the reaction of ortho-chloro-benzaldehyde (2-CI-BZA) with dimethylamine (DMA), in the presence of acetic acid, hydrogen and a nickel catalyst. The examples use a molar ratio of DMA/2-CI-BZA of at least 1.5/1, and demonstrate that a higher yield of the desired product is achieved when this molar ratio is increased further.
[0013] US 2007/0078282 A1 discloses reductive amination using bifunctional catalysts containing a hydrogen-active component with an acidic oxide as cocatalyst. Only example 4 starts from a halogen-containing substrate, the halogen being fluorine. Fluorine is however known to be particularly insensitive to dehalogenation, much less than the other common halogens.
[0014] Other chemical pathways to obtain particularly valuable polyfunctional products containing halogens have also been explored.
[0015] The stoichiometric alternative to the catalytic reductive amination of o-chloro benzaldehyde to obtain o-chloro-benzyl-dimethylamine is exemplified by WO 2013/017611 A1, which describes a process to obtain o-chloro-benzyl-dimethylamine from o-chloro-benzyl chloride and dimethylamine. The yield of the reaction was at most 95.4% of theory. The reaction was performed without involving any catalyst and a chloride salt was obtained as an undesired byproduct. Such processes based on stoichiometric chemistry in general suffer from poor atom efficiency and production of large amounts of waste.
[0016] There therefore remains a need for a highly selective conversion in the reductive amination of only the first functional group, on a substrate containing at least one further functional group containing a halogen atom. The desire is to achieve industrially acceptable reaction rates while keeping the further functional group containing the halogen atom substantially untouched and present in the reaction product.
[0017] It is an objective of the process according to the present invention to carry out the selected chemical reaction with a low degree of dehalogenation. Fluorine is known to be significantly less sensitive to dehalogenation than the heavier and more bulky halogens chlorine, bromine and/or iodine. A fluorine atom initially present in the feed substrate molecule therefore has a higher likelihood to remain present in the reaction product as compared to the other halogens. There therefore remains a particular need for a highly selective catalyst which will allow a low degree of dehalogenation in a substrate containing at least one further functional group containing chlorine, bromine and/or iodine.
[0018] The present invention aims to obviate or at least mitigate the above described problem and/or to provide improvements generally.
SUMMARY OF THE INVENTION
[0019] According to the invention, there is provided a process and a particularly useful composition which may be prepared using the process, as defined in any of the accompanying claims.
[0020] The invention therefore provides a process for performing a reductive amination of a first functional group in an organic feed substrate, which feed substrate comprises at least one further functional group containing a halogen atom, wherein the halogen atom is selected from the list consisting of chlorine, bromine, iodine and combinations thereof, in the presence of hydrogen and a heterogeneous catalyst comprising at least one first metal selected from the list consisting of palladium, Pd, platinum, Pt, rhodium, Rh, iridium, Ir, and ruthenium, Ru, and in absence of a catalytic amount of any second metal selected from the list consisting of silver, Ag, nickel, Ni, cobalt, Co, tin, Sn, bismuth, Bi, copper, Cu, gold, Au and combinations thereof, whereby the heterogeneous catalyst has been heat-treated prior to the reductive amination at a temperature in the range of 100-600° C. for a period of at least one hour, preferably at least two hours.
[0021] The applicants select the first metal from the list consisting of palladium, Pd, platinum, Pt, rhodium, Rh, iridium, Ir, and ruthenium, Ru. More preferably the applicants use palladium or platinum as the first metal. Palladium and platinum are more readily available than most of the other noble metals in the list of first metals, and are therefore more readily obtainable as a raw material, usually also at a lower cost for the production of the catalyst. Palladium and platinum are also metals which are easier to recover or to recuperate from a spent catalyst, and to recycle into a new use. Although palladium and platinum are typically not recognized as highly selective catalysts for performing reductive aminations of substrates containing halogens, we have found that the catalysts containing palladium or platinum as the first metal, and in absence of the second metal as specified above, when properly heat treated according to the present invention, surprisingly combine the benefits of a high activity with a greatly improved selectivity when reacting halogen containing substrates. Without wanting to be bound by this theory, the applicants believe that this surprising effect is related to a growth of the metal particles on the catalyst during the heat treatment. The applicants have at least found indicative evidence hereof by X-ray diffraction (XRD) analysis of catalysts before and after the heat treatment. The applicants believe that this effect and advantage extends also to the other first metals, as specified. Ruthenium may further be advantageous to use as a first metal, because it is also more readily available as compared to some other first metals. One advantage is that is usually also available at a somewhat lower cost.
[0022] Preferably, the applicants use a monometallic catalyst for the process according to the present invention, whereby is meant a catalyst comprising only catalytic amounts of the at least one first metal. We have also found that such a monometallic catalyst is easier to obtain as compared to bimetallic catalysts. Bimetallic catalysts, or catalysts with even more different metals, typically require at least two steps for depositing the metals on the catalyst. With bimetallic catalysts, or catalyst containing even more different metals, whereby the different metals should collaborate with each other in order to obtain the desired catalytic benefits, it is also usually more critical that the metals have the desired distribution over the support surface of the catalyst, and also that the deposits of the different metals are sufficiently close to each other to enable the catalytic cooperation between the two metals. The applicants have found that the catalysts containing only catalytic amounts of the first metals, whereby there is no cooperation between different metals required in order to obtain the desired effect, are easier to obtain as compared to the catalysts requiring the presence of also second metals in catalytic quantities in order to achieve the desired catalytic effects. Furthermore, such single metal or monometallic catalysts may often have a lower risk of metal leaching, and the metal may be more easily recovered and refined from the spent catalyst. Another advantage of monometallic catalysts over bimetallic catalysts is that they may be manufactured with a higher reproducibility.
[0023] We have found that the process according to the present invention is highly selective in performing the desired chemical conversion of the first functional group, while keeping the further functional group containing the halogen atom substantially intact such that the halogen remains present in the reaction product. We have for instance found that the dehalogenation of a halide function as the further functional group on the substrate, a side reaction which is occurring when using monometallic palladium catalyst, may be significantly suppressed, and essentially avoided, when using the process according to the present invention. The dehalogenated byproduct is typically useless, and possibly even a nuisance. The same may apply to the halide containing byproduct (e.g. HX) of the undesired dehalogenation reaction, which for instance may cause corrosion to the reactor or downstream processing equipment. The side reaction thus typically represents a downgrade of valuable starting materials, and adds additional burden for removal of the byproducts from the desired reaction product or for selecting more precious construction materials. The process according to the present invention thus brings the advantage of producing a highly pure desired reaction product, which requires much less clean-up, if any, before it may be put to further use. The process also brings the advantage of highly efficient use of the starting organic substrate, with very low downgrade, if any, to byproducts which may be useless or undesired in the prime reaction product, in which case the byproducts must be separated off and typically discarded or even require additional efforts for disposal in a responsible manner. Furthermore the process according to the present invention avoids the use of expensive and generally less active platinum as the metal in the catalyst without compromising the selectivity.
[0024] The applicants have found that the process according to the present invention may be particularly suitable for the reductive amination of ortho-chloro-benzaldehyde in the presence of dimethyl amine, DMA, to produce ortho-chloro benzyl dimethyl amine, o-CI-BDMA. The applicants have found that the process according to the present invention may produce the desired o-CI-BDMA, also known as ortho-CI-BDMA or 2-CI-BDMA, in very high yield and in particularly high purity, with very little byproducts.
[0025] The process according to the present invention therefore is able to provide a composition comprising, as measured by gas chromatography, GC,
a) at least 98.0% wt of o-chloro-benzyl-dimethylamine, o-CI-BDMA, b) at most 0.40% wt of ortho-chloro toluene, preferably the total of all chloro toluene isomers, and c) at least 0.005% wt or 50 ppm by weight of o-chloro-benzyl alcohol.
[0029] The content of o-chloro-benzyl alcohol in this composition may preferably be at least 0.007% wt of 2-chloro-benzyl alcohol, more preferably at least 0.009% wt, even more preferably at least 0.010% wt, yet more preferably at least 0.012% wt, preferably at least 0.015% wt, more preferably at least 0.020% wt, even more preferably at least 0.030% wt, preferably at least 0.040% wt, more preferably at least 0.05% wt, preferably at least 0.07% wt of 2-chloro-benzyl alcohol, more preferably at least 0.09% wt, even more preferably at least 0.10% wt, yet more preferably at least 0.12% wt, preferably at least 0.15% wt of 2-chloro-benzyl alcohol. Optionally the composition contains at most 1.0% wt of 2-chloro-benzyl alcohol.
[0030] The applicants have found that this composition is particularly suitable as an intermediate for the production of more complex structures in multi-step synthesis routes. Such routes may lead to agrochemical or pharmaceutical active ingredients. The applicants believe that the low presence in the composition of ortho-chloro toluene, more generally the total of all chloro toluenes, in particular of the mono chloro toluenes, and preferably also of chloro dichloromethyl benzenes, also known as chloro benzalchlorides, in particular of o-chloro dichloromethyl benzene, also known as 2-chloro benzyl dichloride or ortho-chloro benzalchloride, preferably below the detection limit in the most appropriate analytical technique, and more preferably the total absence thereof, makes the composition highly suitable for use as raw material in the further steps of many synthesis routes. The applicants have found that the compounds such as a chloro toluene, such as mono chloro toluene, and ortho-chloro dichloromethyl benzene, are contaminants which participate in downstream steps when the composition is used as an intermediate for the synthesis of complex chemical compounds. However, they do not lead to the desired compound and hence represent a loss of valuable reagents. The compounds which result from these contaminants are at best inert but may also exhibit effects which are undesired in the final composition, in which case an excessive occurrence of these side reactions creates a need for extra purification steps in the overall synthesis process.
[0031] The composition containing o-CI-BDMA is in particular useful if such further steps comprise metallation reactions such as lithiation or Grignard reactions, such as described in US 2010/0113778 A1, or coupling reactions such as the reactions known as the Heck, the Sonogashira, the Suzuki or the Stille coupling.
[0032] The applicants have found that a small amount of o-chloro-benzyl alcohol being present in the composition obtainable by the process according to the present invention, which may be present when the composition is obtained using the process according to the present invention, is of little consequence for the further use of the composition, such as in many further synthesis steps and/or many uses of the products thereof.
DETAILED DESCRIPTION
[0033] The present invention will be described in the following with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. Any drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.
[0034] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.
[0035] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.
[0036] The term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Accordingly, the terms “comprising” and “including” encompass the more restrictive terms “consisting essentially of” and “consisting of”.
[0037] The terms “ortho”, “meta” and “para”, abbreviated by o-, m-, p-respectively, are used to indicate the relative position of two substituents on an aromatic cycle, as defined by the International Union of Pure and Applied Chemistry (IUPAC). Taking the standard priority rules for functional groups and substituents into account, their positioning may also be referred to by numbers in chemical nomenclature. In this respect, the indication 2-, 3-, and 4-correspond to o-, m-, and p-respectively.
[0038] In an embodiment, the current invention involves the use of a heat treated Pd catalyst for the reductive conversion of halogenated substrates in the presence of hydrogen, and in particular the reductive amination of such substrates. Being a catalytically very active metal, Pd has the advantage over Pt of being much cheaper and being easier to recover.
[0039] The process according to the present invention is performed in the presence of hydrogen. The use of hydrogen (H 2 ) as the reducing agent is much favoured by the presence of a metal catalyst. Such a catalyst is believed to be instrumental in activating the molecular hydrogen by weakening the H—H bond. Next to the activation of H 2 , the catalyst may also play a role in other reaction steps, such as the other steps involved in the reductive amination mechanism. This role together with the characteristics of the reaction conditions (such as the presence of free amine, water, the typical temperature and pressure range, etc. . . . ) make that reductive amination catalysts are often tailored for this specific process, especially when sensitive (e.g. multifunctional) substrates are involved. It was therefore surprising to see that the heat treated catalyst as used in the process of this invention was found to show such good halogen retention properties.
[0040] Suitable organic feed substrates for the process according to the current invention are organic molecules containing at least one reducible functional group next to at least one halogen atom.
[0041] In an embodiment of the process according to the present invention, the first functional group is selected from the list consisting of an aldehyde, a ketone, and combinations thereof. Reducible functional groups which may suitably be hydrogenated with the heat treated Pd catalyst according to the process of the present invention are ketones, aldehydes, nitro groups, carboxylic acids, carboxylic esters, carboxylic amides, unsaturated carbon-carbon bonds, nitrile, imine and oxime groups. Such functional groups may be present in the substrate already when this is entered into the reactor, but may also be generated in situ during the course of a chemical reaction.
[0042] In an embodiment of the process according to the present invention, the first functional group in the feed substrate is first converted in situ by reaction with an additional reagent to form a reducible functional group. In particular, ketones and aldehydes may be converted to various intermediates, under the conditions of a reductive amination reaction, and which intermediates are subsequently hydrogenated with hydrogen to the final product of the reaction.
[0043] The halogen atom (X) is a selected element from group 17 in the IUPAC periodic table dated 22 Jun. 2007. In an embodiment of the process according to the present invention, the further functional group is selected from the list consisting of a chloride, a bromide and an iodide. The halogen is typically attached to the substrate by means of a covalent bond with a carbon atom (C—X bond). The carbon atom to which the halogen is attached may be either sp, sp 2 or sp 3 hybridized.
[0044] In an embodiment, the process according to the present invention is for the reductive amination of a halo-benzaldehyde in the presence of a nitrogen containing compound, preferably the nitrogen compound being selected from ammonia, a primary amine and a secondary amine, and mixtures thereof, preferably for the production of ortho-chloro benzyl dimethyl amine, o-CI-BDMA, by the reductive amination of ortho-chloro-benzaldehyde in the presence of dimethyl amine, DMA.
[0045] For a reductive amination, chloro benzaldehydes (ortho, meta or pare) are particular interesting substrates, as they may lead to the corresponding chloro benzylamines. Both the chloro and the amine functionality in these reaction products make the products of interest as further chemical building blocks, because the functionalities represent suitable points for further functionalization in subsequent synthesis steps. The chlorine atom offers opportunities for metallation reactions, such as lithiation or Grignard reactions, while the amine group offers possibilities for a further reductive amination or in case of a tertiary amine for quaternisation and conversion into other suitable leaving groups.
[0046] Reductive amination is the reaction well known in chemistry for the synthesis of primary, secondary or tertiary amines starting from a suitable ketone or aldehyde. The term “amination” relates to the reaction part in which an amine functionality is incorporated into the substrate. The term “reductive” relates to the observation, when comparing the feed substrate and the product of a reductive amination reaction, that a reduction has necessarily also taken place. In chemistry, a reduction reaction refers in general to the gain of electrons of an atom or a molecule. In organic chemistry, reductions are usually related with the disappearance of unsaturations, such as double bonds, from the substrate molecules. The net result of a reductive amination of a ketone or aldehyde is the conversion of a C═O double bond into a C—N single bond.
[0047] In an embodiment of the process according to the present invention, the reductive amination is performed in two steps, in the first step reacting the aldehyde with the nitrogen containing compound, and in the subsequent step introducing hydrogen and the catalyst, preferably the two steps being performed in the same reaction vessel. The general mechanism of reductive aminations is believed to start with the nucleophilic addition of ammonia or a primary or secondary amine species to the carbonyl group of the ketone or aldehyde. Such addition may occur with or without the aid of a catalyst. The resulting adduct, sometimes referred to as “hemiaminal”, may react further by the elimination of water to the corresponding imine. The occurrence of imine formation is not essential for the outcome of the reductive amination, and in case of the use of secondary amines as reagents, this even is impossible. In this case, enamines may be formed as intermediates.
[0048] The next step in the mechanism of the reductive amination involves a reduction step. All three of an imine, a hemiaminal or an enamine may be the substrate before and on which the reduction is taking place. For this step, a reducing agent is required, which itself will be oxidized after the reaction has been effectuated. Such as for other hydrogenation reactions, stoichiometric reagents are sometimes used for this purpose, such as for instance formic acid or hydrides such as borohydrides or aluminum hydrides, but from the point of view of atom efficiency and process economics, the use of hydrogen gas is particularly favourable.
[0049] In an embodiment of the process according to the present invention, the heterogeneous catalyst comprises the first metal at a concentration in the range of 0.1-10.0% by weight, preferably at a concentration of at least 0.5% by weight, more preferably at least 1.0%, even more preferably at least 1.5%, yet more preferably at least 2.0%, preferably at least 2.5% by weight, more preferably at least 3.0%, even more preferably at least 3.5%, yet more preferably at least 4.0%, preferably at least 4.5% by weight, and optionally at a concentration of at most 10.0%, preferably at most 9.0%, more preferably at most 8.0% wt, even more preferably at most 7.0% wt, yet more preferably at most 6.0% wt, preferably at most 5.0%, more preferably at most 4.0%, all based on the total weight of the catalyst. The applicants have found that these levels provide an advantageous balance between catalyst performance and the costs and efforts associated with the production of the catalyst.
[0050] In an embodiment of the process according to the present invention, the heterogeneous catalyst comprises the second metal or combinations thereof at a concentration of at most 0.1% by weight, based on the total weight of the catalyst, preferably at most 0.05% by weight, more preferably at most 0.01% by weight, even more preferably at most 0.005% by weight.
[0051] In an embodiment, the process according to the present invention further comprises the step of putting the first metal onto a support by precipitation. The applicants have found that the precipitation method is a very convenient method for putting a metal such as palladium onto a support. Suitable precipitation methods for putting palladium metal onto a support are well known in the art.
[0052] In an embodiment of the process according to the present invention, the chemical conversion selected from reductive amination, and/or the catalyst heat treatment step, is performed in the presence of a solvent, preferably an organic solvent, preferably the solvent comprising at least one alkanol, preferably methanol, preferably the solvent being present in a weight ratio relative to the organic feed substrate in the range of 0.1-20 g/g, preferably at least 0.2 g/g, more preferably at least 0.3 g/g, optionally at most 15.0 g/g, preferably at most 10.0 g/g, more preferably at most 5.0 g/g, even more preferably at most 4.0 g/g, yet more preferably at most 3.0 g/g, preferably at most 2.0 g/g, even more preferably at most 1.0 g/g. Reductive amination reaction and/or the heat treatment step, according to the process of the present invention may occur in any suitable medium. Solvents such as water, alcohols (e.g. methanol), tetrahydrofurane (THF), dioxane, alkanes may be used advantageously. A solvent may bring advantages to such reductive amination reaction, such as an improved hydrogen solubility, a decreased viscosity of the reaction mixture, an improved mixing efficiency, an improved heat transfer, etc. . . . The concentration of the substrate and products in such solvents may be between 1 and 50%, preferably between 5 and 40%, more preferably between 10 and 40% by weight, based on the total reaction mixture. Highly diluted reaction mixtures may result in poor space-time yields, while in case of highly concentrated reaction mixtures, the benefits of the solvent may be minimized. In case the reaction substrates and products are liquids under the reaction conditions applied, the reaction may be performed without the addition of a solvent. One may also choose to add small amounts of solvents to the reaction mixture, e.g. 1 to 50%, preferably 5 to 40%, more preferably 10 to 30% by weight, relative to the total reaction mixture. Such addition may have particular advantages such as to improve the catalyst performance, to decrease the autogenous pressure of the reaction mixture, to prevent phase separation to occur, etc. . . .
[0053] In case of the reductive amination of o-chloro benzaldehyde with dimethyl amine (DMA), we have found that the addition of small amounts of methanol to the reaction mixture improves the yield and operability of the process significantly. Without wanting to be bound by this theory, the methanol is believed to increase the solubility of the highly volatile amine and therefore enhancing the reaction rate in the liquid phase. Additionally, the presence of methanol may possibly prevent the occurrence of two separate liquid phases during the reductive amination, possible because of any liberation of water as the co-product in the reaction.
[0054] In an embodiment of the process according to the present invention, the heterogeneous catalyst has been heat treated, such as prior to its use in the process, at a temperature in the range of at least 200° C., preferably at a temperature of at least 250° C., more preferably at least 300° C., even more preferably at least 350° C., yet more preferably at least 400° C., and optionally at a temperature of at most 550° C., preferably at most 500° C., even more preferably at most 450° C., preferably the heat treatment being performed for at least 1 hour, preferably 2 hours, more preferably at least 3 hours, even more preferably at least 4 hours, yet more preferably at least 5 hours, preferably at least 6 hours, more preferably at least 7 hours, even more preferably at least 8 hours, and for at most 24 hours, preferably at most 18 hours, more preferably at most 12 hours, even more preferably at most 10 hours, yet more preferably at most 8 hours, preferably at most 6 hours, more preferably at most 5 hours, even more preferably at most 4 hours, yet more preferably at most 3 hours. The applicants prefer to heat-treat the catalyst at about 400° C., in nitrogen, for a period of about 2 hours with a N 2 flow at a velocity expressed as weight/weight/hour (WWH) of about 0.225-0.250 per hour (h −1 ), and this after first having dried the catalyst at about 80° C. for a period of 3 hours, in stagnant air or preferably under a flow of gas to remove water vapour, i.e. until no substantial further weight loss of the catalyst being dried could anymore be noticed.
[0055] In an embodiment of the process according to the present invention, the atmosphere during the heat treatment is a gaseous atmosphere, more preferably selected from the list consisting of hydrogen H 2 , nitrogen N 2 , an inert gas and air.
[0056] In an embodiment of the process according to the present invention, the heat treatment of the heterogeneous catalyst has been performed by exposure to a flow of gas at a WWH in the range of from 0.0200 to 2.0000 h −1 , preferably at least 0.0375 h −1 , more preferably at least 0.050 h −1 , even more preferably at least 0.075 h −1 , yet more preferably at least 0.120 h −1 , preferably at least 0.150 h −1 , more preferably at least 0.200 h −1 , even more preferably at least 0.220 h −1 , and optionally at most 1.500 h −1 , preferably at most 1.000 h −1 , more preferably at most 0.500 h −1 , even more preferably at most 0.300 h −1 . The applicants have found that the heat-treatment under these conditions is particularly convenient but also particularly effective in obtaining the technical effects which are the target of the present invention.
[0057] In an embodiment of the process according to the present invention, the heterogeneous catalyst at the start of the heat-treatment contained at most 10% wt of free water, preferably at most 8% wt of free water, more preferably at most 5% wt of free water, preferably at most 3.0% wt of free water, more preferably at most 2.0% wt of free water, even more preferably at most 1.0% wt of free water, and optionally at least 0.01 wt % free water. The applicants have found that this feature reduces the risk that the heterogeneous catalyst becomes damaged during the heat-treatment step. Free water is defined in this context as the water which may be removed by drying at a temperature of at most 100° C., as observed by weight loss.
[0058] In an embodiment of the process according to the present invention, the heterogeneous catalyst has been dried prior to the heat-treatment. The applicants have found that a drying step is a very convenient step in order to achieve a limited free water content of the heterogeneous catalyst, which was found to bring the advantage of reducing the risk that the heterogeneous catalyst becomes damaged during the heat-treatment step. A drying step is defined in this context as an heating of the catalyst to a temperature of less than 100° C. for a period of time suitable for removing the desired amount of free water, as measurable by weight loss. The drying step may be performed using a heated gas flow to remove vaporising water. The drying step may be performed separate from the heat treatment step, or may be performed during the starting phase of the heat treatment step, for instance by keeping the catalyst under a gas flow at the prescribed temperature for a suitable time before the temperature is raised for starting the heat treatment. The applicants have found that this last combination of drying step and heat treatment step is particularly convenient for implementation at a commercial scale.
[0059] In an embodiment of the process according to the present invention, the heat treatment is made in the presence of a substrate or a solvent. Preferably the substrate is in the liquid form. The applicants have found that the use of a liquid during the heat treatment is a very convenient way to bring heat energy into the heterogeneous catalyst which is solid. The applicants have found that transferring heat to a solid by use of a liquid is much more effective than by using only a gaseous carrier for introducing the heat energy.
[0060] In an embodiment of the process according to the present invention, the heterogeneous catalyst has a support selected from the list consisting of carbon, alumina, silica, zeolite, clay, porous polymer and hybrid polymer, preferably a carbon support, more preferably an activated carbon, even more preferably an activated carbon which has been activated by a treatment with an acid. The applicants have found that the heterogeneous catalyst on a carbon support is particularly sensitive to the heat treatment according to the present invention, and that such catalyst is particularly effective in obtaining the desired effect of the present invention.
[0061] For the ease of handling, the catalyst is preferably supported on a solid carrier. A suitable carrier for the support of the metals in the catalyst of the process according to the present invention is activated carbon, because of its large specific surface area and its good adhesion properties. Further treatment, such as steaming, acid washing, sulphonation, or the like, may be given to the support, because this often enhances the adsorption properties of the activated carbon. Other carbon carriers such as graphite or carbon nanotubes (CNT) may be used as the support of the catalyst. Carbon supports offer the additional advantage that the process for recycling the metal or metals, at the end of life of the catalyst, is much simplified as compared with other supports.
[0062] Other types of materials known by people skilled in the art may suitably be used as the catalyst support: alumina, silica, zeolite, clay, porous polymer and hybrid polymer, and combinations thereof.
[0063] The total metal loading on the catalyst support may be in the range of 0.1 to 40% by weight, more preferably at least 0.2%, more preferably 0.5%, more preferably at least 1.0%, even more preferably at least 2.0%, yet more preferably at least 3.0%, more preferably at least 4.0%, even more preferably at least 5.0%, and optionally at most 35% by weight, preferably at most 30%, more preferably at most 25.0%, even more preferably at most 20.0%, yet more preferably at most 15.0%, preferably at most 10.0%, more preferably at most 7.5%, even more preferably at most 5.0%, whereby the levels are expressed relative to the total weight of the catalyst.
[0064] The supported catalyst may occur in a form which is most suitable and desired for the process, such as a powder, in the form of a granule, an extrudate, or combinations thereof. With a powder catalyst, the catalyst may after use be separated from the reaction mixture by filtration. With granules and/or extrudates, the catalyst and the reaction mixture may be separated from each other by simple draining of the reactor vessel containing the catalyst, which may for instance be arranged in a fixed bed arrangement.
[0065] In an embodiment of the process according to the present invention, the heterogeneous catalyst has a metal area, as measured by carbon monoxide chemisorption of at least 0.5 m 2 /g, preferably at least 1.0 m 2 /g, more preferably at least 2.0 m 2 /g, even more preferably at least 3.0 m 2 /g, yet more preferably at least 4.0 m 2 /g, optionally at most 12.0 m 2 /g.
[0066] In an embodiment of the process according to the present invention, the heterogeneous catalyst has an average metal particle size in the range of 2 to 20 nm, preferably at least 2.0 nm, more preferably at least 3.0 nm, even more preferably 4.0 nm, optionally at most 20.0 nm, preferably at most 15.0 nm, more preferably at most 12.0 nm, even more preferably at most 10.0 nm, yet more preferably at most 9.0 nm or even at most 8.0 nm. The average metal particle size is preferably measured using X-ray powder diffraction (XRPD), whereby the applicants prefer to use the Sherrer equation based on half-peak width.
[0067] In an embodiment of the process according to the present invention, the heterogeneous catalyst has been pre-reduced prior to the step of contacting the catalyst with the organic feed substrate, preferably by subjecting the catalyst at a temperature of at least 120° C., preferably at least 140° C. to a hydrogen atmosphere of at least 5 bar gauge, preferably at least 8 bar gauge during a period of at least 30 minutes, preferably at least 45 minutes, preferably the pre-reduction being performed with the catalyst being in contact with an organic liquid phase, preferably an alkanol, more preferably methanol. The applicants prefer to perform this pre-reduction step with the catalyst in contact with methanol, at a temperature of about 150° C., and under a hydrogen partial pressure of about 10-11 bar absolute, and this for a period of about three hours. Alternatively, the applicants may perform the pre-reduction step with the catalyst in contact with methanol at a temperature of about 180° C., and under a hydrogen partial pressure of about 10-11 bar absolute, and this for a period of about one hour. The applicants have found that this pre-reduction step allows the catalyst to exhibit its desired advantageous performance from very early on after starting the process.
[0068] In an embodiment of the process according to the present invention, at least 80% of the feed substrate is retaining the at least one further functional group after the conversion, preferably at least 85%, more preferably at least 90%, even more preferably at least 95%, preferably at least 97%, more preferably at least 98%, even more preferably at least 99.0%, preferably at least 99.4%, more preferably at least 99.5%, even more preferably at least 99.6% of the feed substrate is retaining the at least one further functional group after the conversion. The applicants have found that these results are readily achievable with the catalyst of the process according to the present invention.
[0069] In an embodiment of the process according to the present invention, the reductive amination is performed at a H 2 partial pressure in the range of 0.01-250 bar gauge, preferably at least 0.1, more preferably at least 1, even more preferably at least 5.0 bar gauge, even more preferably at least 10.0 bar gauge, yet more preferably at least 20 bar gauge, preferably at least 30 bar gauge, more preferably at least 40 bar gauge, even more preferably at least 50 bar gauge, and optionally at most 200 bar gauge, preferably at most 150 bar gauge, more preferably at most 100 bar gauge, even more preferably at most 80, yet more preferably 70, and preferably at most 60 bar gauge.
[0070] In an embodiment of the process according to the present invention, the reductive amination is performed at a temperature in the range of 0-300° C., preferably at least 10° C., more preferably at least 20° C., even more preferably at least 30° C., yet more preferably at least 40° C., preferably at least 60° C., more preferably at least 80° C., and even more preferably at least 90° C., and optionally at most 250° C., preferably at most 200° C., more preferably at most 180° C., even more preferably at most 150° C., yet more preferably at most 130° C., preferably at most 120° C., more preferably at most 110° C., even more preferably at most 100° C.
[0071] In an embodiment, the process according to the present invention is performed in continuous mode. The applicants have found that the catalyst itself, as well as its performance, may be arranged to be fairly stable over time, such that the process is highly suitable for a continuous operating mode. This brings significant advantages in terms of production rate, volumetric efficiency of the process equipment, control equipment, steadiness of performance, operator attention and intervention frequency, automation capabilities, many of which represent significant advantages to the process owner.
[0072] The applicants have found that the process according to the present invention may also be performed in batch mode. The applicants have found that the catalyst, upon separation from the reaction medium after a first performance of the process, may readily be reused in a second performance of the process, preferably without any intermediate treatment. The applicants have found that at least 5, preferably at least 10, and more preferably at least 15 reuse cycles may be performed with the same catalyst in the process according to the present invention. The applicants have found that some metal may leach from the catalyst during the early performances of a fresh catalyst in the process according to the present invention, but that such metal leaching is at a level which is substantially insignificant in terms of amount of metal lost from the catalyst, and also does not cause any substantial loss of performance of the catalyst.
[0073] In an embodiment, the process according to the present invention further comprises the purification of the converted substrate, preferably by the distillation of the reaction product, for reducing the content of at least one compound selected from a reaction byproduct, a feed impurity, a solvent, and unreacted feed substrate.
[0074] In an embodiment wherein the process according to the present invention is used for the production of ortho-chloro benzyl dimethyl amine, 2-CI-BDMA, the process is further comprising subjecting the 2-CI-BDMA to a Grignard reaction, comprising for example in a first step the preparation of a Grignard reagent in which a magnesium atom is introduced in between the benzene ring and the chlorine atom, followed by a second step wherein the Grignard reagent is reacted with an oxalic acid dialkyl ester.
[0075] In an embodiment wherein the process according to the present invention is used for the production of ortho-chloro benzyl dimethyl amine, 2-CI-BDMA, the process is further comprising the conversion of 2-CI-BDMA into o-chloromethylphenylglyoxylic esters by a method such as described in US 2010/113778 A1. o-Chloromethylphenylglyoxylic esters are important intermediates for preparing agrochemically active compounds or microbicides of the methoximinophenylglyoxylic ester series. More particularly, US 2010/113778 A1 describes the production of strobilurines, a type of fungicides that are stated to inhibit the respiratory system of the fungi, and of which Kresoxim-methyl and Dimoxystrobin are named and exemplified as particularly interesting family members. In a further embodiment therefore, the process according to the present invention further comprises the production of a fungicide containing a methoximinophenylglyoxylic ester derivatived from 2-CI-BDMA, in particular derived from the composition according to the present invention.
[0076] In an embodiment wherein the process according to the present invention is used for the production of ortho-chloro benzyl dimethyl amine, 2-CI-BDMA, the process is further including the step of treating a surface with the fungicide containing the methoximinophenylglyoxylic ester which was derived from the 2-CI-BDMA obtained with the reductive amination. Such a surface may be from, but is not limited thereto, an agricultural field, an orchard, a leaf or stem of an agricultural crop, a slab, a floor tile, a façade, a wall or a roof of a building, a cardboard box or any other kind of packaging material, a portion of human skin, of human mucosa, of animal skin, or of animal mucosa. The fungicide composition may be a solid, such as a powder, or a liquid, in which the ester may be dissolved or dispersed in a carrier or solvent. The step of using the fungicide composition may be performed using any one of the methods known in the art, and combinations thereof, such as by spraying, by brushing, by pouring, by dusting, by mixing and the like, including combinations thereof.
[0077] In an embodiment of the composition produced by the process according to the present invention, the composition comprises at least 98.5% wt of 2-chloro-benzyl-dimethylamine, preferably at least 99.0% wt, more preferably at least 99.1% wt, even more preferably at least 99.2% wt, yet more preferably at least 99.3% wt of 2-chloro-benzyl-dimethylamine. The higher the content in 2-chloro-benzyl-dimethylamine, the more advantageously the composition may be applied in its desired application, such as a conversion to a further chemical derivative.
[0078] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.04% wt of 2-chloro-dichloromethyl benzene, preferably at most 0.030% wt, more preferably at most 0.020% wt, even more preferably at most 0.015% wt, preferably at most 0.010% wt, more preferably at most 50 ppm by weight, even more preferably at most 10 ppm, of 2-chloro-dichloromethyl benzene. This component may represent an additional burden in applying the composition, such as generating corrosive components in subsequent reactions, and/or leading to undesired byproducts in subsequent conversions. The lower the content of 2-chloro-benzylchloride, the more advantageously the composition may be applied in its desired application, such as a conversion to a further chemical derivative.
[0079] In an embodiment, the composition produced by the process according to the present invention comprises at least 0.07% wt of 2-chloro-benzyl alcohol, preferably at least 0.09% wt, more preferably at least 0.10% wt. even more preferably at least 0.12% wt, yet more preferably at least 0.15% wt of 2-chloro-benzyl alcohol.
[0080] In an embodiment, the composition produced by the process according to the present invention comprises at most 1.0% wt of 2-chloro-benzyl alcohol, preferably at most 0.80% wt, more preferably at most 0.60% wt, even more preferably at most 0.50% wt, yet more preferably at most 0.40% wt of 2-chloro-benzyl alcohol.
[0081] The applicants have found that the 2-chloro-benzyl alcohol may acceptably be present in the composition without jeopardising or affecting the performance of the composition in many of its applications, such as particular conversions into further chemical derivatives, in particular those conversions and uses which have been described in more detail elsewhere in this document. The applicants have found that there is for many of such applications little to no need for the removal of any 2-chloro-benzyl alcohol which may be present in the composition, in particular not when it is present at the levels as specified. This represents an advantage because the removal of 2-chloro-benzyl alcohol from the prime product 2-chloro-benzyl-dimethylamine, and this to very low levels, may bring significant additional complexity to the process.
[0082] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.20% wt of 2-chloro-benzaldehyde, preferably at most 0.15% wt, more preferably at most 0.10% wt, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC, if needed assisted by mass-spectrometry. This 2-chloro-benzaldehyde does not contribute to many of the applications of the composition. A presence at a lower level of this component therefore represents an improved effectiveness and brings improved efficiencies in the further use and application of the composition.
[0083] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.40% wt of 4-chloro-benzyl dimethylamine, preferably at most 0.30% wt, more preferably at most 0.20% wt, even more preferably at most 0.10% wt of 4-chloro-benzyl dimethylamine, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC. The applicants have found that this component may represent an additional burden in applying the composition, such as in subsequent reactions, and/or may lead to undesired byproducts in subsequent conversions which in addition may be rather difficult to separate from the desired product of such conversion. The lower the content of 4-chloro-benzyl dimethylamine, the more advantageously the composition may be applied in its desired application, such as a conversion to a further chemical derivative.
[0084] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.35% wt of ortho-chloro toluene, preferably at most 0.30% wt, more preferably at most 0.20% wt. even more preferably at most 0.10% wt of ortho-chloro toluene, preferably at most 0.05% wt, more preferably at most 0.03% wt, even more preferably at most 0.01% wt, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC. Preferably the specified levels apply to the total of all chloro toluene isomers together. The applicants have found that this component, and also its isomers, may represent an additional burden in applying the composition, such as in subsequent reactions, and/or may lead to undesired byproducts in subsequent conversions which in addition may be rather difficult to separate from the desired product of such conversion. The lower the content of chloro toluenes, in particular of ortho-chloro toluene, the more advantageously the composition may be applied in its desired application, such as a conversion to a further chemical derivative.
[0085] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.40% wt of benzyl dimethyl amine, preferably at most 0.30% wt, more preferably at most 0.20% wt, even more preferably at most 0.10% wt of benzyl dimethyl amine, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC. This benzyl dimethyl amine does not contribute to many of the applications of the composition. A presence at a lower level of this component therefore represents an improved effectiveness and brings improved efficiencies in the further use and application of the composition.
[0086] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.40% wt of 2-dimethylaminobenzyl dimethylamine, preferably at most 0.30% wt, more preferably at most 0.20% wt, even more preferably at most 0.10% wt of 2-dimethylaminobenzyl dimethylamine, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC. This 2-dimethylamino-benzyldimethylamine does not contribute to many of the applications of the composition. A presence at a lower level of this component therefore represents an improved effectiveness and brings improved efficiencies in the further use and application of the composition.
[0087] In an embodiment, the composition produced by the process according to the present invention comprises at most 0.40% wt of benzaldehyde, preferably at most 0.30% wt, more preferably at most 0.20% wt, even more preferably at most 0.10% wt of benzaldehyde, preferably at most 0.05% wt, more preferably at most 0.020% wt, even more preferably at most 0.010% wt, preferably at most 50 ppm by weight, more preferably at most 10 ppm, even more preferably at most 5 ppm, yet more preferably at most 1 ppm by weight, as determined by gas chromatography, GC. This benzaldehyde does not contribute to many of the applications of the composition. A presence at a lower level of this component therefore represents an improved effectiveness and brings improved efficiencies in the further use and application of the composition.
[0088] The applicants have found that the process according to the present invention is particularly suitable, because the process is able to provide a high reaction rate and conversion to the desired 2-chloro-benzyl-dimethylamine, which achieves low levels of the unconverted feed substrate 2-chloro-benzaldehyde, and thanks to the high selectivity of the catalyst as specified, with low presence of less desired byproducts, such as 2-chloro-benzyl alcohol and/or benzyl dimethyl amine and/or 2-dimethylamino-benzyldimethylamine. In addition, the process according to the present invention for the production of 2-chloro-benzyl-dimethylamine has little to no presence of the other undesired components 2-chloro-benzylchloride and/or 4-chloro-dimethylbenzylamine and/or chloro toluene isomers, in particular ortho-chloro toluene. The composition obtainable by the process according to the present invention is thus particularly suitable for use in many of its applications, such as particular conversions into further chemical derivatives, in particular those conversions and uses which have been described in more detail elsewhere in this document.
Analyticals
[0089] For analysing the composition produced by the process according to the present invention, as well as in the monitoring of the process according to the present invention, the applicants prefer to use the following gas chromatography, GC, analytical method.
[0090] The GC apparatus is preferably an Agilent 6890N with split injector and a flame ionization detector (FID). The apparatus is equipped with a capillary column coated with a stationary phase type CP-Sil 5 CB with dimensions 60 m×320 μm×5.0 μm. The applicants prefer to use an injector temperature of 280° C., an injector volume of 1 μlitre and a split ratio of 1/30. The applicants prefer to use helium as the carrier gas, with a flow of 2 ml/min at constant flow. The oven is given a temperature program of holding for 3 minutes at 60° C., and subsequently ramping up the temperature at a rate of 20° C. per minute up to 290° C., at which temperature the column is kept for an additional 15 minutes. The FID detector is kept at 300° C., and fed with a hydrogen flow of 45 ml/min and an air flow of 450 ml/min. Make up gas, preferably nitrogen, and column flow together are set at a total of 45 ml/min.
[0091] The applicants have found that the following components may readily be identified by specific retention peaks: methanol, DMA, TMA, ethylbenzene, benzaldehyde, benzyl dimethyl amine, ortho-chloro benzaldehyde, ortho-chloro benzylalcohol, ortho-chloro benzyl dimethyl amine, para-chloro benzyl dimethyl amine, ortho (dimethylamino) benzyl dimethyl amine. The applicants have further found that this GC technique may readily be assisted with the addition of mass-spectrometry, such as for determining concentrations in the lower levels down to 1 ppm wt or even below.
[0092] Depending on the sample, the sample may be diluted up to 10 times in isopropanol. Preferably 1% of the internal standard is added, upon which the sample is preferably vigorously mixed for at least one minute, and after which 1 μl of sample may be injected into the gas chromatograph.
EXAMPLES
Example 1: Preparation of Pd Catalysts
[0093] A 5% wt palladium catalyst having activated carbon (AC) as its support, commercially available under the reference E196NN/W 5%, was obtained from the company Evonik. An amount of 10 g of this catalyst was dried at 80° C. in static air for 3 hours and subsequently heat-treated under a nitrogen flow of either 10 ml/min or 30 ml/min, which respectively correspond to a WWH of 0.08 h −1 and 0.25 h −1 , at the temperatures as specified below during a heat-treatment time of either 2 or 4 hours. Various different combinations of heat-treatment temperature, nitrogen flows and heat-treatment time parameters were tested in order to determine the effect of these parameters on the performance of the heat-treated catalyst.
Example 2: Preparation of Pt Catalysts
[0094] A 5% wt platinum catalyst having activated carbon as its support, commercially available under the reference F 1015 RE/W 5%, was obtained from the company Evonik. An amount of 10 g of this catalyst was dried at 80° C. in static air for 3 hours and subsequently heat-treated under a nitrogen flow of either 10 ml/min or 30 ml/min, which respectively correspond to a WWH of 0.075 h −1 and 0.225 h −1 , at a temperature of 400° C. during a heat-treatment time of 2 hours. In addition, a Pt catalyst was tested having the same properties but having Al 2 O 3 as the support. This 5% wt Pt on alumina was a commercial catalyst, obtained as such from the company Sigma Aldrich. Various different combinations of the nitrogen flows and other parameters were tested on these Pt-based catalysts, in order to determine the effect of these heat treatment parameters on the performance of the heat-treated catalyst.
Example 3: Reductive Amination of 2-Chloro-Benzaldehyde with DMA to Produce 2-CI-BDMA
[0095] In each experiment, a 100 mL autoclave (Parr) was loaded with 2.5 g of 2-chloro benzaldehyde (2-CI-BZA) obtained from the company Sigma Aldrich and 12 ml of dimethyl amine in methanol solution having a concentration of 2 mole per litre (2M or 2 Molar). The reactor was sealed and the gas phase was flushed three times with nitrogen and then pressurized at 5 bar by the addition of nitrogen gas. The reactor was heated at 80° C. and then continuously stirred for 60 minutes at a temperature of 80° C. and a pressure of 5 bar. Then, the reactor was cooled to 30° C. and degassed. 8 mg of the catalyst obtained from Example 1 or Example 2 was added to the autoclave. The autoclave was heated in 15 minutes to 100° C. and hydrogen was added to a final pressure of 40 bar. The reductive amination reaction was allowed to proceed for the indicated time at 100° C. Then the reactor was cooled down and degassed at room temperature. Subsequently, a sample of the reaction product liquid was taken and analysed by gas chromatography (GC) and inductively coupled plasma spectroscopy (ICP). In one experiment, the catalyst was filtered and recycled in a repeat experiment in a second run under the same conditions.
[0096] The results obtained were reported in Tables 1 to 6. They are all expressed as selectivity (%), and hence are excluding any water, methanol, residual dimethylamine or 2-CI-BZA which might still have been present in the reaction product samples.
[0097] Table 1 reports the results obtained using the palladium catalysts obtained from Example 1, primarily for different heat-treatment temperatures. The selectivity of the reaction for the catalysts which were heat-treated at 100° C. or 200° C. during only 2 hours is moderately improved compared to the selectivity of the reaction for the untreated catalyst. A much higher selectivity and yield may be observed for the catalyst which was heat-treated at the higher temperature of 400° C. In addition, the high selectivity brings the advantage of simplifying the product separation downstream of the reaction.
[0000]
TABLE 1
Catalyst
2-
and heat-
Reaction
2-Cl-
DMA-
2-Cl-
treatment
time
Conv
BDMA
BDMA
BDMA
BOH
Others
details
(min)
(%)
(%)
(%)
(%)
(%)
( %)
5% Pd/AC
15
99.9
45.8
33.4
—
0.1
20.7
untreated
5% Pd/AC
15
99.5
45.3
35.2
—
0.2
19.3
N2, 100° C.,
2 h, 30
ml/min
5% Pd/AC
15
94.3
42.4
39.3
—
0.3
18.0
N2, 200° C.,
2 h, 30
ml/min
5% Pd/AC
15
44.0
2.1
97.8
—
—
—
N2, 400° C.,
30
82.3
2.4
96.2
—
1.1
<0.5
2 h, 30
ml/min
[0098] Table 2 shows the beneficial effect of a higher nitrogen flow for the palladium catalyst as prepared in Example 1, heat-treated under different nitrogen flows. A high nitrogen flow of 30 ml/min during the heat-treatment step significantly improved the selectivity of the reductive amination both for 15 min and for 30 min reaction time, as compared to those for a nitrogen flow of 10 ml/min.
[0000]
TABLE 2
Catalyst
2-
and heat-
Reaction
2-Cl-
DMA-
2-Cl-
treatment
time
Conv
BDMA
BDMA
BDMA
BOH
Others
details
(min)
(%)
(%)
(%)
(%)
(%)
(%)
5% Pd/AC
15
65.7
22.1
67.8
—
—
10.1
N2, 100° C.,
30
89.6
23.5
66.8
—
0.5
9.2
2 h, 10
ml/min
5% Pd/AC
15
44.0
2.1
97.8
—
—
—
N2, 400° C.,
30
82.3
2.4
96.2
—
1.1
<0.5
2 h, 30
ml/min
[0099] Table 3 shows the effects of heat-treatment time on the palladium catalysts from Example 1, heat-treated at the high temperature of 400° C. during either 2 hours or 4 hours, and this under a nitrogen flow of either 10 ml/min or 30 ml/min. Compared to the performance of the untreated catalyst, shown in Table 1, the selectivities obtained with heat-treated palladium catalysts are more favourable for all the examples listed in Table 3. Even the lower heat-treatment time at the low WWH (10 ml/min) already significantly improved the selectivity compared to untreated catalyst, albeit at the expense of some loss in conversion. The conversion loss was demonstrated to be readily recoverable by extending the reaction time, and this while the selectivity remained practically constant. Intensifying the heat-treatment by using a higher WWH of about 0.25 h −1 (30 ml/min) significantly increased selectivity. Any penalty suffered on conversion by this change may readily be recovered by extending the reaction time. The best performing catalyst is the one that has been heat-treated for a longer time and at a higher WWH (30 ml/min). This particular catalyst combines a very high activity with a high selectivity, and hence results in a high yield.
[0000]
TABLE 3
Catalyst
2-
and heat-
Reaction
2-Cl-
DMA-
2-Cl-
treatment
time
Conv
BDMA
BDMA
BDMA
BOH
Others
details
(min)
(%)
(%)
(%)
(%)
( %)
(%)
5% Pd/AC
15
65.7
22.1
67.8
—
—
10.1
N2, 400° C.,
30
89.6
23.5
66.8
—
0.5
9.2
2 h, 10
ml/min
5% Pd/AC
15
44.0
2.1
97.8
—
—
—
N2, 400° C.,
30
82.3
2.4
96.2
—
1.1
<0.5
2 h, 30
ml/min
Pd/AC
15
99.4
5.9
93.7
—
0.6
—
N2, 400° C.,
4 h, 30
ml/min
[0100] The palladium catalyst which had been heat-treated at 400° C. for 2 hours under a 30 ml/min nitrogen flow, was recycled once in order to compare its performance in a second run with its performance in the first run. The results are shown in Table 4. The performance in the second run remained very comparable to this in the first run.
[0000]
TABLE 4
Reaction
2-Cl-
2-DMA-
2-Cl-
time
Conv
BDMA
BDMA
BDMA
BOH
Others
Run
(min)
(%)
(%)
(%)
(%)
(%)
(%)
1
30
82.3
2.4
96.2
—
1.1
<0.5
2
30
80.4
3.1
95.6
—
1.2
—
[0101] Tables 5 and 6 report results obtained with the platinum catalysts from Example 2.
[0102] Table 5 shows the effect of a higher nitrogen flow on the platinum catalysts from Example 2, heat-treated during 2 hours, under nitrogen flows of either 10 ml/min or 30 ml/min. Also for the platinum catalyst, any of the heat-treatments improves both the activity and the selectivity, regardless of what the nitrogen flow was.
[0000]
TABLE 5
Catalyst
2-
and heat-
Reaction
2-Cl-
DMA-
2-Cl-
treatment
time
Conv
BDMA
BDMA
BDMA
BOH
Others
details
(min)
(%)
(%)
(%)
(%)
(%)
(%)
5% Pt/AC
15
87.9
—
88.1
—
4.2
6.7
untreated
5% Pt/AC
15
88.3
—
94.8
—
4.6
0.2
N2, 400° C.,
2 h, 10
ml/min
5% Pt/AC
15
99.9
—
96.5
—
3.1
0.2
N2, 400° C.,
2 h, 30
ml/min
[0103] Table 6 shows the results obtained with platinum catalysts supported on Alumina (Al 2 O 3 ), untreated or heat-treated at 400° C. for 2 hours under a nitrogen flow of either 10 ml/min or 30 ml/min. Also for the platinum on aluminium oxide catalyst, the heat-treatment is demonstrated to improve the yield of the reaction; i.e. there is found a better performance in the combination of activity and selectivity, and thus a lower dehalogenation. In both cases, a longer reaction time pushes the conversion, while the selectivity of the reaction hardly changes. The effects of the present invention are thus proven to be also achievable with a support which is different from the activated carbon (AC) in the other examples.
[0000]
TABLE 6
Catalyst
2-
and heat-
Reaction
2-Cl-
DMA-
2-Cl-
treatment
time
Conv
BDMA
BDMA
BDMA
BOH
Others
details
(min)
(%)
(%)
(%)
(%)
(%)
(%)
5% Pt/
15
71.1
—
58.5
—
39.1
1.6
Al2O3
30
86.9
—
61.5
—
36.8
1.4
untreated
5% Pt/
15
69.3
—
65.4
—
30.2
—
Al2O3
30
92.8
—
64.5
—
28.3
1.1
N2,
400° C.,
2 h, 10
ml/min
Legend:
Conv
Conversion
2-Cl-BZA
2-chloro-benzaldehyde
BDMA
Benzyl dimethylamine
2Cl-BDMA
2-chlorobenzyl dimethylamine
DMA-BDMA
2-dirnethylarninobenzyl dimethylamine
2-Cl-BOH
2-chlorobenzyl alcohol
[0104] Having now fully described this invention, it will be appreciated by those skilled in the art that the invention can be performed within a wide range of parameters within what is claimed, without departing from the scope of the invention, as defined by the claims.
|
Disclosed is a process for performing a reductive amination of a first functional group in an organic feed substrate, which feed substrate comprises at least one further functional group containing a halogen atom, wherein the halogen atom is selected from the list consisting of chlorine, bromine, iodine, and combinations thereof, in the presence of hydrogen and a heterogeneous catalyst comprising at least one metal from the list of Pd, Pt, Rh, Ir, and Ru, and in absence of any catalytic amount of any second metal from the list consisting of Ag, Ni, Co, Sn, Bi, Cu, Au, and combinations thereof. The process is preferably applied for the reductive amination of 2-chloro-benzaldehyde to form 2-chloro-benzyldimethylamine, as an intermediate in the production of active agrochemical compounds and microbicides of the methoximinophenylglyoxylic ester series.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a Non-Provisional of U.S. Provisional (35 USC 119(e)) Application No. 60/917,792 filed May 14, 2007.
TECHNICAL FIELD OF THE INVENTION
[0002] In the field of sonography, ultrasound images are produced by an ultrasound imaging system (scanner) that includes a transducer to ensonify (transmit ultrasound energy into) an anatomical region of interest and to receive the energy response of the tissue. Typically, the system controls the signals transmitted by the transducer, processes the electronic signals received, and presents the resulting images on a display device. Depending on the application and the processing applied to the received signals, the images may represent the spatial variation of the reflected energy itself or other parameters of interest (e.g., the distribution of blood flow velocity, etc.). In medical applications, the image or a sequence of images allow a trained reader to diagnose possible abnormal conditions that otherwise would be unobservable.
BACKGROUND OF THE INVENTION
[0003] Many techniques have been developed to transmit and receive ultrasound energy, to process the received data, and to condition the images for display. Typically, the transducer is composed of several individual elements that independently transmit and receive ultrasound energy. To form diagnostically useful images, the received ultrasound energy is focused into beams by summing weighted contributions from the individual elements at carefully selected (and dynamically adjusted) sample times to compensate for the differences in propagation time from each element to points along the beam. Transmit beams are also formed by controlling the relative time of the transmissions from the individual elements. Conventional ultrasound scanners construct image data for a single frame by transmitting and receiving many such beams in succession. The image sequence presented to the human reader and used for diagnosis is constructed from a series of such frames.
[0004] The quality of the image sequences produced by conventional ultrasound scanners has several limitations. For example, the frame rate, or temporal resolution, is limited by the propagation time of the ultrasound beams and the fact that constructing a frame of image data requires many sequential beam transmissions. To produce useful image data at acceptable frame rates, ultrasound scanners must process data received from many independent channels (transducer elements) at very high sample rates (e.g., 64 channels at 24 MHz sample rate). This imposes stringent data throughput and computational requirements that are difficult to satisfy. Conventional ultrasound scanners typically address these requirements by incorporating dedicated and highly specialized hardware (e.g., custom designed analog circuitry or digital ASICs) to beamform and to process the resulting data. Because the hardware is so specialized, the functions of these systems are fairly rigidly defined and not easily reconfigurable. Also, once combined by the hardware to form beam data, the original element data are lost (i.e., hardware beamforming is an irreversible process) and are not available for additional processing. For example, if it is desired to form more than one beam from a set of element data by applying different sets of weights and delays (e.g., to increase frame rates), multiple hardware beamformers are required, adding to system complexity, cost, and power consumption.
[0005] Another drawback of typical hardware-based beamforming is that it is difficult to use the beamformed data for more than one image modality. The consequence of this is that frame-rates are often dramatically reduced when two or more parametric image sequences (e.g., reflectivity and color velocity) are simultaneously displayed. New parametric image techniques that would expand the diagnostic utility of ultrasound are difficult to achieve because of the rigidity of typical hardware-based beamforming systems.
[0006] Spatial resolution is limited by the fact that each transmit beam is typically well focused at only one point (at most) because the relative timing of the respective element transmissions is fixed for each transmission event. Image quality is also limited by the fact that the display coordinates typically do not match the locations where the beams are sampled (e.g., the data may be acquired in polar coordinates, but the image pixels on a display are typically arranged in a rectangular grid). Image formation then requires an interpolation process that is an approximation, resulting in a loss of information.
[0007] In addition to the foregoing problems, the information contained in the image data from many conventional scanners is limited to a single two-dimensional plane that has a fixed orientation with respect to the transducer. Methods and apparatuses, typically referred to as 3D/4D systems, have been introduced to address this limitation. These systems interrogate an anatomical volume of interest with ultrasound and reconstruct the received data for the entire volume. A variety of methods may then be used to construct images and image sequences for the entire volume or for desired two-dimensional slices through it. Frame rates and/or spatial resolution are sacrificed, however, because data for the entire volume must be acquired and processed.
BRIEF SUMMARY OF THE INVENTION
[0008] The present disclosure is directed to systems and methods which allow for ultrasound parameter estimation to occur at specific advantageous sets of points in a two- or three-dimensional field of view within re-configurable, massively parallel, programmable architectures that can accommodate the input/output streaming, data movement or storage, and computation requirements. In one embodiment, a power efficient system is used for processing the data thereby increasing the ability of the system to be used for hand carried or mobile ultrasound applications.
[0009] One aspect of the concepts discussed herein is the architectural aspects which provide the ability to simultaneously accept a large number of channels of data characterized by a continuous, simultaneous flow at high sample rates. The input data is routed at high rates to a distributed and large number of processing elements, memory, and connections for simultaneous parameter estimation at multiple points in the field of view. The ability to route the same data to multiple places enables high frame rates and allows for the streaming of data through the architecture. The ability to reconfigure the system allows for the estimation of various types of parameters at different times or even simultaneously. The architecture is extensible through interconnections between physical devices.
[0010] Another aspect to the acquisition of parameter estimation is the use of filters (linear or non-linear) for correcting diffraction and/or propagation effects per channel. These filters also can delay channel data for localizing the estimation of a parameter to a particular locality such as done in beamforming, and controlling signal, clutter, noise, and various forms of resolution. The filtered data may be combined in a number of ways. Acquisition of multiple sets of points for display is possible. For example, multiple planes (lines) through a two- or three-dimensional field of view may be formulated from the same acquired data, thereby avoiding the need for scan conversion and rendering when the sets of points correspond to displayed pixels. It is also possible within this system to localize the parameter estimation process by synthesizing the source signal.
[0011] Another aspect to parameter estimation is the ability to re-configure and/or re-program the architecture to apply the proper operations for the estimation of a particular parameter or parameters such as reflectivity, elasticity, strain rate, and motion.
[0012] The foregoing has outlined rather broadly 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. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0014] FIG. 1 illustrates one embodiment of a system for employing the techniques of the invention;
[0015] FIG. 2 illustrates one embodiment of some of the architectural elements within the invention;
[0016] FIG. 3 illustrates one embodiment of a physical device conforming to the architectural elements within the invention;
[0017] FIG. 4 illustrates one embodiment of interconnected processors which extend the architectural elements of the invention; and
[0018] FIG. 5 illustrates one embodiment of a system for employing the parameter acquisition techniques of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 illustrates one embodiment 10 of a system for employing the techniques of the invention. Transducer 101 , as is well-known in sonography, sends sound signals into a body, such as a human body, and receives the echoes therefrom. The returned echoes in the form of acoustic information are translated into electrical signals which then, as will be discussed, are used to estimate various parameters at advantageous sets of geometric locations. In one embodiment, this estimation is accomplished by Massively Parallel Processors (MPP) 30 for presentation to user 13 . Front end 19 receives the return electrical signals from the ensonified volume, compensates and filters this data and then presents this volume data to analog to digital converter (ADC) 18 . These digitized signals representing the return echoes (energy response) may be streamed through MPP subsystem 12 .
[0020] One embodiment of MPP subsystem 12 is depicted in three parts. MPP 30 performs beam forming, signal processing, parameter estimation, and other operations to create images suitable for the user using signals from ADC 18 . MPP control interface 11 configures MPP 30 to perform the appropriate functions based on instructions that are received from controller 15 which, in turn, are based upon selections from the user 13 .
[0021] Database 14 supplies pre-determined and default processing control variables required by MPP 30 . Data from MPP 30 is passed along to image and video processing 16 for further formatting and processing of data for presenting to the user through Display 17 . In one embodiment, elements 12 , 14 , 15 , 16 , and 17 can be contained in a device weighing 10 lbs. or less.
[0022] FIG. 2 illustrates one embodiment 20 of some of the elements within MPP Subsystem 12 . Digital signals from ADC 18 are received by input interface 24 and formatted to be presented to digital signal conditioning process 25 which performs signal processing operations, typically filtering, that are advantageous to apply prior to beam formation.
[0023] The conditioned data is then presented to coherent spatial/temporal filtering and combining process 26 . This function seeks to enhance and localize, typically with some form of filtering, whether it be linear or non-linear, the accurate estimation of parameters at advantageous sets of geometrical locations Some functions performed here, that are well known by those experienced in the art, are demodulation, beam forming including multi-line beam forming, cross correlation, normalization, multi-rate quadrature band pass (QBP) filtering, Doppler wall filtering, and fast Fourier transforms (FFT) which among other advantages improve signal to noise and clutter. These functions may be also used to improve various forms of resolution metrics, including axial resolution, lateral resolution, contrast resolution, and detail resolution. The generation of parameters to support these functions is also a function suitable to process 26 .
[0024] Image data that are localized and enhanced at geometrically advantageous geometric locations are then presented to parameter estimation process 27 which generates the particular estimates of the type of parameters to be used for display. Some functions performed here, that are well known by those experienced in the art, are detection of signal intensity, compression, Doppler wall filter filtering for flow imaging, segmentation, velocity estimation, strain estimation, strain rate estimation, classification, spatial compounding, scan conversion, rendering, and spatial-temporal image processing.
[0025] One embodiment of MPP control interface 11 performs three functions. As will be described hereinafter, data router 21 configures the connectivity of the distributed bus architecture of MPP 30 to effectively route data among the distributed processing elements and memory devices. Static and dynamic control variable generator 22 distributes and/or creates control variables required for the various data processing functions. Some of these control variables may be pre-computed and retrieved from database 14 ( FIG. 1 ) while others may be newly generated using, for example, processors within MPP 30 . Finally, code distribution and reconfiguration process 23 governs what processing algorithms are to be accomplished on which processors and in which order.
[0026] FIG. 3 shows one embodiment of massively parallel processor (MPP) 30 . The actual form which the hardware (ASIC, FPGA, etc.) takes is not critical to the operation of the concepts discussed herein. These concepts rely, instead, on a massively parallel, re-configurable, and distributed network of processing elements, memory, and communication or equivalent thereto. These features enable the high aggregate rates of data movement required by ultrasound and reduce high bandwidth demands on memory devices by enabling streaming of data, multiple and simultaneous use of data, and re-routing of data. Moreover, these features enable the functionality to be changed or multiple functions corresponding to different ultrasound modalities to be configured for simultaneous operation even using the same echo returns.
[0027] The internal processors are interconnected by a distributed network of connections which allow for efficient transfer and replication of data. Ultrasound applications have high bus bandwidth requirements which are more easily satisfied with a distributed network of buses. Port 306 allows this particular processor to extend communicating to other processors on other MPP devices. Ports 305 are similar types of ports which allow wide bandwidth data input and output to the MPP. Fabric 307 allows connectivity to occur among and between individual processors such that, if necessary, data produced by one processor can be used simultaneously by several other processors. This then allows for efficient replication of data. Moreover, this allows beam forming to be simultaneously processed at multiple sets of geometrical locations.
[0028] It is envisioned that the individual processors making up the MPP will carry out their designated operations independently of each other except for the flow of data. They will also be able to be configured or rapidly re-configured to perform individual operations which when appropriately connected performs useful ultrasound applications. These processors need not be homogeneous. In the embodiment shown, there are several different types of processors, 301 , 302 , 303 , 304 , etc. Some types of processors are optimized for specific functions while others handle more general purpose processing needs. The optimized processors may be functional acceleration units (specialized processors) to carry out dedicated functions with greater efficiency than the general purpose processors for ultrasound applications. For example, one type of processor may be particularly suited for geometric transformations while another may be suited for accelerating fast Fourier transforms or cross correlations.
[0029] It is envisioned that the memory is also distributed in order to accommodate the high memory bandwidth needs of ultrasound applications. To accomplish this, data is stored, for example on distributed memories 308 , in association to where that data is required to be used and not according to a centralized memory architecture typical of the microprocessor architectures of personal computers.
[0030] In operation, MPP 30 can receive a multiplexed, encoded set of individual channels or individual elements from the array via ports 305 . This data is then processed, on a channel by channel basis, in a manner required for that channel at that moment in time. The processing depends, at least in part, on the user selected surfaces through the ensonified volume. Since the different or same channels can be processed differently and repeatedly, the system allows for the desired processing at the desired surfaces defined by the advantageous sets of geometrical locations. The use of streaming in such architecture reduces power requirements as it avoids massive usage of memory.
[0031] Returning now to FIG. 1 , MPP control interface 11 provides information to MPP 30 for controlling the individual MPP devices, thereby allowing for the selection of one or more different surfaces to be presented concurrently. The configuration of the MPP devices can be static, which means that control variables and configuration information are pre-computed and retrieved by the controller from the database. The configuration can be dynamic in that selections for the configurations by the user, or other source, are given to the MPP subsystem which computes new processing control variables and configuration settings.
[0032] FIG. 4 shows one embodiment 40 of the interconnection of MPPs 30 . Ports 305 and 306 are used for collecting data from the transducer as well as for connecting with other similar MPP devices. This allows for the efficient transfer of data and for the overall compute power to be increased as needed to accommodate the required signal or image processing. This also allows for assigning more or less individual processing elements, such as arithmetic logic units, memory, storage, etc. into a data stream for processing. The control of the processors, as well as the functions performed by the different processors, can be controlled, as discussed, by programmable digital processing elements. This programming can be accomplished by a variety of techniques, including, for example, machine language code or binary images. The elements could contain, if desired, field programmable gate arrays (FPGA).
[0033] FIG. 5 shows one embodiment 50 of the non-traditional ultrasound imaging capability that is afforded by the concepts discussed herein. In this embodiment, transducer 101 ( FIG. 1 ) is used to ensonify a volume 501 . Volume 501 is depicted as a two-dimensional array although analogous imaging can be performed by other transducer element arrangements to form, if desired, a three-dimensional array or one-dimensional array. As conditioned, digitized, return echoes are able to be replicated by the architecture, simultaneous beam forming can be accomplished along multiple surfaces 502 , 503 , 504 , and 505 using the same ensonified volume data 501 . This is of significant advantage to ultrasound imaging as only one ensonification sequence is required to form multiple images as with the case of 3D/4D modality where multiple and orthogonal planes are typically presented. This allows greatly improved frame rates to be displayed, for example, on display 17 .
[0034] Although the surfaces in FIG. 5 indicate planes, other surfaces can be more advantageous. Such surfaces might also include contours along anatomical features, such as along boundaries of the heart or other organs. Also, the system could be made to beam form to pre-determined surfaces rotated or translated in several degrees of freedom by the user. At any point in time the user can select separate surfaces and present the selected surfaces concurrently on different portions of the display screen. Some of the views could be from planes that are rotating or otherwise changing so as to present a changing image on the display. Thick surface or stacked parallel surfaces may also be acquired for rendering purposes. All of these views of the target image are anchored without necessarily moving transducer 101 . In one embodiment, the MPP system is used to assist in computing new control variables to quickly reconfigure the system for the user directed imaging selections. Flexibility is required since the system must be able to quickly reconfigure the computation based on the user input.
[0035] It is easily seen that the time course of imaging parameters along an arbitrary contour through the field of view can be accurately and efficiently measured and displayed.
[0036] Another advantage to the acquisition approach of this invention implicit in FIG. 5 , is the ability to form beams at geometrical locations that directly correspond to pixels on the display. In this way, approximations and unwanted artifacts of scan conversion, rendering, and beam under-sampling can be avoided which greatly improves image quality. Zooming an image may be implemented by this invention as forming beams to a new, more dense set of geometrical locations corresponding to the desired locations of the new pixel centers.
[0037] Furthermore, since beam formation occurs at pixel locations, the number of different planes to be displayed simultaneously on the display does not increase beamforming requirements and frame rates need only be limited by the deepest depth in the field of view.
[0038] Note that in addition to displaying images that represent the intensity of the sound reflected along a selected plane, other parametric images can be formed to present different tissue properties, such as strain or other modalities that require additional processing. These different modalities may be performed simultaneously with the same received echoes, which greatly improves imaging rate. Also, it is desirable to provide multiple images of surfaces or volumes without moving the transducer. For example, as discussed, the imaging display is partitioned so as to present different images of the same target simultaneously without moving the transducer. Each window of the display may show a different projection of the volume acquisition signal or different parameters thereof. Also, size can be varied with respect to each window.
[0039] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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The present disclosure is directed to systems and methods which allow for ultrasound parameter estimation to occur at specific advantageous sets of points in a two- or three-dimensional field of view within re-configurable, massively parallel, programmable architectures that can accommodate the input/output streaming, data movement or storage, and computation requirements. In one embodiment, a power efficient system is used for processing the data thereby increasing the ability of the system to be used for hand carried or mobile ultrasound applications. One aspect of the concepts discussed herein is the architectural aspects which provide the ability to simultaneously accept a large number of channels of data characterized by a continuous, simultaneous flow at high sample rates. The input data is routed at high rates to a distributed and large number of processing elements, memory, and connections for simultaneous parameter estimation at multiple points in the field of view. The ability to route the same data to multiple places enables high frame rates and allows for the streaming of data through the architecture.
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TECHNICAL FIELD
The invention concerns a method for the production of foils of elastomeric material, as well as the use of these foils in bonding objects with a high E-modulus, particularly parts in the manufacture of skis, where the foil is inserted as an intermediate layer, which has the effect of reducing the shearing forces which can appear in the adhesive joint during the elastic deformation of the parts bonded to each other, hence particularly in ski production.
STATE OF THE ART
In the bonding of parts with a high E-modulus it is known to insert a rubber foil into the adhesive joint. This is done preferably by coating the surfaces to be joined with each other, as well as the surfaces of the rubber foil with an adhesive that hardens when heated, and then, after inserting the rubber foil as an intermediate layer between the surfaces to be joined with each other, bonding the whole by the application of pressure and heat supply.
In a ski manufacturing method, where a bonding method of this type can be used with advantage, the skis are produced first from at least substantially plate-shaped parts which are bonded with each other.
The deformations to be absorbed by the adhesive joints, when such a ski is stressed for bending, are generally the greater the more rigid the material of the parts to be bonded with each other is, and the shearing forces appearing in the adhesive joint are the greater, the greater these deformations are or the thinner the adhesive joints are. The known method for bonding two parts has the effect that these shearing forces remain within certain limits. The deformation appearing in the bonded zone under bending stress is now absorbed substantially by the intermediate rubber layer. The effect of these intermediate rubber layers is described in detail in Austrian patent application Ser. No. 351,416 of the applicant.
The use of these intermediate rubber layers in the bonding of parts with a high E-modulus is not without problems in practice. First of all, in order to obtain the quality and uniformity of the adhesive joint, the rubber foil used as an intermediate layer should have a thickness of about 0.1 to 0.2 mm with a possibly low thickness tolerance. Rubber foils in this thickness range are very difficult to produce, however, and only with a relatively high thickness tolerance. Thus, e.g. rubber foils with a thickness of 0.13 mm can only be obtained with a thickness tolerance of ±0.03 mm, and the quality that can be achieved when they are used as intermediate layers in adhesive joints is therefore limited. Besides, these rubber foils must be subjected additionally to a special surface treatment by wet-chemical methods to obtain a good adhesion in bonding their surfaces.
DESCRIPTION OF THE INVENTION
The invention is based on the problem of providing a method for the manufacture of foils of elastomeric material where the foils can be produced with a lower thickness tolerance than rubber foils and require no surface treatment to increase their adhesive power.
The problem underlying the invention is solved by the method for the production of foils of elastomeric material according to the invention, which is characterized in that
a. resins based on polyisocyanates and polyhydroxy-compounds and/or polyamines, or
b. resins based on polyepoxide compounds and polyhydroxy-compounds and/or polyamines and/or polycarboxyl compounds, or
c. an impregnating mixture based on rubber latex
are applied in liquid form in a continuous process on a unwoven fabric, which can preferably be a tangled unwoven fabric, and that the unwoven fabric passes through a zone of elevated temperature where the resins or the impregnating mixture harden and/or dry in foil form to an elastomer, containing the fibers of the unwoven fabric. The resins used in liquid form can be present with advantage in the form of dispersions.
According to an advantageous embodiment of the method according to the invention, when resins based on polyisocyanates are used, these resins are reactive resins of at least one polyisocyanate components and one polyhydroxy-component, which can contain preferably a preliminary product of polyisocyanates and polyhydroxy-compounds. At least one of the polyhydroxy-compounds used in the preparation has the formula ##STR1## where A denotes one of the groups --CH 2 -- or >C═O and (m+q) assumes the values 4 to 30. In the meaning of A=--CH 2 --, n can assume with advantage the value 3, p the value 4, and (m+q) the values 6 to 30, and in the meaning of A=>C═O, n can assume the value 4, p the values 2 to 6, and (m+q) the values 4 to 20.
According to another advantageous embodiment of the method according to the invention, when using an impregnating mixture based on rubber latex, this mixture can contain a carboxylated styrene-butadiene-latex and, if necessary, additionally a vulcanizing agent which can be preferably a formaldehyde condensation product. The solid content of the formaldehyde condensation product used in the mixture can be preferably 5 to 30% by weight.
In another advantageous embodiment of the method according to the invention, the impregnating mixture contains additionally a natural rubber latex, where the solid ratio of styrene-butadiene-latex to natural rubber latex is preferably between 1:2 and 2:1.
It was found that foils with a thickness of 0.1 to 0.2 mm can be produced with the method according to the invention with a relatively low thickness tolerance of ±10%. This is due to the fact that the unwoven fabrics used have an absorption power which is uniform over their entire surface, and the resin or impregnating mixture, which is in liquid form, can be applied evenly by means of known proven methods, e.g. by impregnation or brushing. The resins or impregnating mixtures according to the invention are not sticky without special additives, as long as they are in liquid form, which has the result that the application of the liquid resin on the bonded fabric presents no problem. The solid elastomer formed is only sticky in the partly hardened or dried state, that is, while the unwoven fabric laden with the resin or impregnating mixture passes through the zone of elevated temperature, hence during its passage through a continuous furnace. During this passage, the unwoven fabric can be conducted contact-free, e.g. suspended on an air cushion. This way technical problems, which can be caused by the stickiness of the drying or hardening elastomer, are avoided in a simple manner.
In the finished foil, the fibers of the unwoven fabric no longer form a continuous matrix, so that they do not decisively alter the mechanical properties of the elastomer.
The invention also concerns the use of the foil of elastomeric material obtained with the method according to the invention, which is characterized in that the foil, which has a thickness tolerance of ±10%, is arranged as an intermediate elastomer layer in the adhesive joint when bonding two parts with a high E-modulus.
The best way for realizing the invention
For the production of the foil we start from a tangled unwoven cotton fabric in web form, which is withdrawn continuously over a winding mandrel and then conducted over guide rollers through a tank containing the impregnating resin or impregnating mixture, and subsequently through a pair of squeezing rolls to calibrate the resin coat.
When using an impregnating resin, the composition of which will be described below in three examples, this impregnating resin has preferably an impregnating viscosity in the range of 10,000 to 100,000 mPa, the optimum viscosity value depending on the gross density of the tangled unwoven fabric used, and which can be adjusted, if necessary, by the addition of a suitable non-reactive solvent.
When using an impregnating mixture based on rubber latex, which is present in the form of an aqueous dispersion, and for the composition of which two formulas are given below, this impregnating mixture has preferably an impregnating viscosity of 50 to 500 mPa, where the optimum viscosity value--similar as with the use of impregnating resins-depends on the gross density of the tangled non-woven fabric and can be adjusted, if necessary, by the addition of water.
After passing through the impregnating plant and the squeezing rolls, the impregnated web enters a hot air shaft in which is passes freely suspended through several separately controlled heating zones, and at the end of which it is withdrawn as a non-sticky foil web, and then wound as an endless band.
The following table contains for different thicknesses of the foil to be produced the quality of the non-woven fabric used and of the resin-or impregnating coat (in percent of the gross weight of the fabric, and calculated in the dried and/or hardened state).
______________________________________Foil thickness Tangled non-woven cotton fabric Coatin mm weight in g/m.sup.2 %______________________________________0.15 18 ab. 4000.20 26 ab. 6500.25 26 ab. 900______________________________________
Here are the five preferred impregnating resin formulas:
1. For the production of a solvent-free impregnating resin, a preliminary product is prepared from (all values are in parts by weight)
66 parts diphenylmethane-4,4'-diisocyanate as a technical crude product (NCO-content ab. 31%) (bought under the tradename Desmodur VL by BAYER) and
200 parts of a linear polyether containing hydroxyl groups with an average molar weight of 2000 and an OH-content of 1.7% (bought under the trade name Desmophen 1900U by BAYER) with
0.6 parts zinc octate as a catalyst to which 7 parts 1,4-butanediol are added at room temperature.
The gelling time of the impregnating resin thus produced is more than 4 hours at room temperature.
2. For the production of an impregnating resin, a mixture is formed at room temperature which consists of (in parts by weight)
212 parts of a 67% solution of a preliminary product of trimethylolpropane-toluylenediisocyanate with a NCO-content of about 11.5% and an equivalent weight of about 262 in ethylglycol acetate as a solvent (bought under the tradename Desmodur by BAYER),
98 parts of a branched polyether ester containing hydroxyl groups with content of about 5% OH and an equivalent weight of about 340 (bought under the tradename Desmophen 1150 by BAYER),
245 parts of a linear polyester containing hydroxyl groups with a content of about 1.7% OH and an average molar weight of about 2000 (bought under the tradename Desmophen 1652 by BAYER), as well as
0.5 parts N-methylmorpholine as a catalyst.
The impregnating resin thus prepared has a gelling time of more than 12 hours at room temperature.
3. For the production of an impregnating resin, a mixture of (in parts by weight)
66 parts polytetrahydrofuran (molar weight ab. 650) as a polyhydroxy-component,
33.3 parts isophorone diisocyanate
6.3 parts 1,3-butanediol
20 parts ethylglycol acetate and
0.03 parts dibutyl-tin-dilaurate
was heated under constant stirring to 75 deg. C., and the stirring was continued until the polyaddition reaction was completed (disappearance of the NCO-conent), and then cooled.
The impregnating resin obtained by adding to this mixture 25.3 parts of a technical trimethylol-toluylene diisocyanate adduct in the form of a 67% solution in ethylglycol acetate.
The gelling time of the impregnating resin thus produced is more than 6 hours at room temperature.
4. For the production of the impregnating resin were mixed (in parts by weight)
41.5 parts polycaprolactone (molar weight ab. 830) as a polyhydroxy-component, and
20 parts ethylglycol acetate
to obtain a clear solution.
The impregnating resin is then obtained by adding to this solution
42 parts of a trimethylol propane-isophorone-diisocyanate adduct in the form of a 70% solution in ethylglycol acetate
The gelling time of this impregnating resin is more than 8 hours at room temperature.
5. The impregnating resin consists of a mixture produced at room temperature of (in parts by weight)
100 parts of a copolymer of butadiene-acrylonitrile containing carboxyl end groups, with an average molar weight of 3300 and a carboxyl functionality of ab. 1.8
12 parts glycerin triglycide ether with an epoxide equivalent of ab. 120-140,
0.5 parts 2,4,6-tris-(dimethylaminomethyl)-phenol
20 parts furnace soot
40 parts toluene as a solvent.
This impregnating resin has a gelling time of more than 24 hours at room temperature.
Here are two preferred formulas for impregnating mixtures based on rubber latex.
6. For the production of an impregnating mixture based on rubber latex are mixed (in parts by weight)
100 parts (related to the dry substance) of a carboxylated butadiene-styrene-copolymer latex with a styrene portion of 45% and a carboxylic acid portion of 3% by weight in the copolymer, and
30 parts (related to solid resin) of a methyl-etherified melamine-formaldehyde-resin whose melamine-formaldehyde ratio is 1:3.1, where the total portion of dry substance is set to about 55% by weight.
The stability of this impregnating mixture in storage is about 12 hours.
7. In a preferred variant of this impregnating mixture according to formula 6, are added
65 to 260 parts (related to the rubber dry substance) of a 60% centrifuged commercial available natural latex stabilized with 0.7% ammonia.
With this addition of natural latex, the mechanical toughness of the resulting elastomer can be increased or adjusted to the desired value within a wide range.
Industrial utilization
The foils produced with the method according to the invention are used for bonding, particularly in metal-metal bonding, and especially in the manufacture of skis, where they are inserted as intermediate layers in the adhesive joints. If commercial adhesives on an epoxide resin base are used, the bonding qualities are good and very uniform. Drum peeling tests according to DIN 53295 show high peel strength values.
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A method for producing elastomeric foils by continuously impregnating a non-woven fabric with a resinous composition in liquid form selected from the group consisting of (a) a resin based on polyhydroxy compounds or polyamines or mixtures thereof and polyisocyanates, (b) resins based or polyhydroxy compounds or polyamines or polycarboxyl compounds or mixtures thereof and polyepoxides and (c) an impregnating mixture based on rubber latex, drying and curing the impregnated fabric freely suspended in hot air and removing the dried foil which is useful as an intermediate layer in the bonding of objects with a high E-molulus and the bonded object per se.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is in the field of construction and pertains more particularly to conduit systems passing through structural members for electrical, venting, and plumbing requirements of the construction.
[0003] 2. Discussion of the State of the Art
[0004] In the field of construction, building codes exist that govern how conduit systems are routed through structural members of a frame construction. A conduit system may be any system of pipes or jackets used to carry water (in the case of plumbing), air and other gases (in the case of venting systems), or electrical wiring (in the case of electrical systems and components).
[0005] One aspect of building code deals with holes or bores placed through structural members of a framed building including wall studs, floors, and ceilings. The code typically specifies a nominal diameter for a hole that may be placed through a support member without a requirement for adding additional structural support to compensate for the weakening of the structural member.
[0006] In current art systems, round holes are conventionally used to provide passage of a conduit section through a solid support or structural member. Although codes may vary from region to region, the nominal diameter is typically about two inches for conduit for plumbing or for carrying electrical wiring. At or over 2 inches in diameter the code typically requires some support element such as a Simpson brace to be installed at the site of the hole to compensate for the weakening of the structural member. Conduit systems may range in diameter from very small, say one inch or less in diameter, to eight or more inches for some venting requirements. In any case, holes placed in structural members above a specific diameter must be reinforced causing additional expense to the construction in labor and materials.
[0007] What is clearly needed in the art is an adapter system for routing a conduit through structural members in a manner that reduces or eliminates labor and materials for reinforcing structural members that have been prepared to accept the conduit system.
SUMMARY OF THE INVENTION
[0008] A problem stated above is that conventional conduit systems installed in construction must be routed through structural members of the construction in certain instances and that additional effort and materials must be applied to reinforce those structural members hosting the conduit system when the diameter of the bores placed through the structural members reaches a threshold size specified by building code. All conduit systems are standardized for construction and meet code requirements for serving their purposes in the construction.
[0009] The inventor therefore searched components of conduit systems and construction materials and methods looking for components and methods that could be modified economically to provide a conduit system of a diameter at or greater than the threshold size that could be routed through structural members without requiring code-specified reinforcement of those structural members.
[0010] In an inventive moment, the inventor conceived of a conduit adapter system that could be coupled with standard conduit system types for the purpose of bridging those conduit systems through structural members of the construction in a manner that reduces or eliminates the effort and materials otherwise required to reinforce structural route points in the construction. Use of the system resulted in less work and materials expense for construction projects.
[0011] Accordingly a conduit adapter system enabling routing of conduit through one or more structural members of width W with minimal weakening of the structural member or members is provided, comprising a first section of conventional round conduit on one side of the structural member or members, and a second piece of round conduit on an opposite side of the structural member or members, and a bridge conduit section of sufficient length to pass through the structural member or members, the bridge conduit section having a symmetrical cross-section with a first dimension significantly less than a second dimension, and an area at least as large as the area of the round conduit sections. The bridge conduit section passes through an opening through the structural member or members of substantially the shape of the cross-section of the bridge conduit section such that the first, smaller dimension of the opening is in the direction of width W of the structural member, and is joined by adapter sections to the round conduit on each side of the structural member or members.
[0012] In another aspect of the invention, in a conduit system comprising typically round conduit sections, a method for routing through a structural member of width W with minimum weakening of the structural member is provided, comprising steps of (a) providing a bridge conduit section of sufficient length to pass through the structural member, the bridge conduit section having a symmetrical cross-section with a first dimension significantly less than a second dimension, and an area at least as large as the area of the round conduit sections; (b) forming an opening through the structural member of substantially the shape of the cross-section of the bridge conduit section such that the first, smaller dimension of the opening is in the direction of width W of the structural member; (c) passing the bridge conduit section through the opening in the structural member; and (d) adapting the bridge conduit to the round conduit with adapter units having the round conduit shape at one end and the bridge cross-section shape at the other.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0013] FIG. 1 is an elevation view of a conduit system routed through structural members of a construction according to existing practice.
[0014] FIG. 2 is perspective view of a conduit system route-through junction according to the example of FIG. 1 .
[0015] FIG. 3 is a perspective view of a conduit system route-through junction according to an embodiment of the present invention.
[0016] FIG. 4 is a perspective view of a conduit section with an oblong cross section according to an embodiment of the invention.
[0017] FIG. 5 is a perspective view of a conduit right-angle elbow with an oblong cross-section according to an embodiment of the present invention.
[0018] FIG. 6 is a perspective view of a conduit elbow with an oblong cross-section according to an embodiment of the invention.
[0019] FIG. 7 is a perspective view of a transitional conduit connecter according to an embodiment of the present invention.
[0020] FIG. 8 is a perspective view of a conduit routing adapter system routed through a frame structural member of a construction according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0021] As described above, a problem with certain diameter conduit systems is that when routing such systems through structural members the bore sizes required through the structural members significantly weaken those members requiring additional measures and materials in the construction to compensate.
[0022] FIG. 1 is an elevation view of a conduit system routed through structural members of a frame construction according to existing practice. A frame construction 100 is illustrated in this embodiment as a typical construction where conduit of some type would be required in the construction framework. Construction 100 is likened to a kitchen remodel or new kitchen construction in this example.
[0023] Frame construction 100 is typical for a kitchen area and includes support for a large picture or bay window 102 . Window 102 may be any type of window but is likely to be a large bay window that provides a view for those working in the kitchen. The framework of construction 100 must be robust enough to support the weight of the window.
[0024] Construction 100 is bounded at either end by structural members 111 at both sides for framing purposes only. A bottom plate 110 is provided as the lower-most structural member of the framed construction, which includes the wall framing members supporting the window. A double top plate 101 provides a ceiling support or top of the construction 100 . Certain structural members are required to support the weight of window 102 . These include vertical 2×4 members and other structural members.
[0025] Window 102 is bounded on the outside of the framing by two vertical “king” studs 104 . Two vertical “trimmer” studs 105 are provided adjacent to the king studs. These form the vertical frame support members on either side of window 102 . Three vertical “cripple” studs 106 are illustrated in the construction beneath window 102 and the sill framing. These studs directly support the weight of window 102 . A header 103 is installed in the construction directly above the window.
[0026] Generally speaking, a counter and sink including plumbing, cabinetry, and the like will be installed directly beneath the window with such elements tied into the structural framing of the construction including the mentioned studs. This example is just one example of a framing through which a conduit system will be routed and connected. In this case a conduit system installed for this construction area may involve kitchen plumbing for the sink, including a sink drain and vent, and perhaps plumbing to other appliances that require water.
[0027] A conduit system is illustrated in this example and includes a sink drain 108 and a sink drain vent pipe 109 . Vent pipe 109 extends through double top plate 101 at a junction B. The conduit system is routed in the wall through all three studs 104 , 105 , and 106 at a junction A to reach the vertical sink drain installed under a kitchen sink. Sink drain 108 is routed either through the wall or through the bottom plate to a septic or sewer outlet outside of the home.
[0028] The diameter of the conduit system including sink drain 108 and vent pipe 109 may exceed the nominal diameters for which additional structural support must be applied to compensate for the bores placed through studs 104 , 105 , and 106 , and through double top plate 101 and bottom plate 110 . Simpson bracing or other types of metallic braces are required in this construction at junctions A and B. Without the required bracing, the vertical studs supporting the window on one side would be much weaker at junction A than the counterparts on the other side. The double top plate supporting the ceiling and other framing components would be weakened at the point of junction B without bracing.
[0029] It has occurred to the inventor that by altering the cross-sectional profile of the conduit at the junction points A and B, the conduit may be routed through those junctions without significantly weakening those structural members.
[0030] The inventor therefore constructed a unique conduit adapter system for routing conduit systems in construction through structural members in a fashion that requires no additional structural support to the host structural member hosting the junction. The invention is described in enabling detail using the following examples.
[0031] FIG. 2 is perspective view of a conduit route-through junction according to the example of FIG. 1 . To further illustrate the problem with routing round conduit through structural members, a structural member 200 is illustrated in isolation from a construction framing. Structural member 200 may be a vertical stud of junction A of FIG. 1 for example.
[0032] For a 2 inch outside diameter conduit 202 , a two inch (plus clearance) diameter bore 201 is made through structural member 200 , which is a nominal 2×4 stud in this example. With the bore centered on the 3.5 inch face of the stud, approximately ¾ inch of material remains one each side of the bore. The stud is thus severely weakened at the area of the bore.
[0033] FIG. 3 is a perspective view of a conduit route-through junction according to an embodiment of the present invention. A 2×4 stud 300 is illustrated in this example, as in FIG. 2 , and may represent one of the vertical members of junction A in FIG. 1 . In this example, a conduit adapter section 302 is provided in place of the conduit 202 . Conduit adapter 302 is rectangular rather than round. The width of conduit adapter 302 is 1 inch. The area of the round conduit in the example of FIG. 2 is 3.142 square inches. To avoid constricting the conduit in FIG. 3 , causing loss of flow (in the case of gases or water), the area must be maintained, at least 3.142 square inches. So the height of the rectangular cross-section must be 3.142 inches minimum. Because of additional surface area inside the adapter section, and the change in dimensions, either of which may cause some flow constriction, a larger cross-section is desirable, so the height may in this case be as much as 4 inches.
[0034] Section 302 does not have to be of a rectangular cross-section in order to practice the invention as other shape may also provide a reduction on the bore requirement for a round conduit. An elliptical or oblong cross-section is also suitable for the application.
[0035] To accommodate adapter section 302 through member 300 , a rectangular slot is made vertically through 2×4 300 and is just wider than 1 inch and of suitable length in order to accept section 302 therethrough. Slot 301 provides 1.25 inches on each side of the opening, rather than the ¾″ as in the example of FIG. 2 , leaving 2×4 300 much stronger at the junction than 2×4 200 . Therefore, no additional structural support measures or materials are required to conform to building code. Section 302 represents a section of conduit that presents a cross-sectional profile that differs from that of conduit 202 . The inventor provides connector pieces (not shown) that enable section 302 to be plumbed into the original conduit system as is detailed further below. Depending upon the nature of the construction, structural members may be of other sizes than two by four inch studs.
[0036] The total area of conduit 202 is at least maintained by conduit section 302 so that there is no bottleneck or reduction of volume rate at the junction point where the conduit is routed through the structural member. What is lost in diameter of the conduit is made up for in the length of the adapter section. The requirement for shoring up the framing member using metallic bracing is reduced or eliminated altogether. The inventor provides connectors that work to bridge the conduit system through one or more structural members as required using components of the system including conduit adapter sections similar to section 302 .
[0037] FIG. 4 is a perspective view of a conduit section 400 with a somewhat oblong cross-section according to an embodiment of the invention, rather than rectangular. Conduit section 400 may be extruded or molded and cut to varying lengths (L) for standard applications. Section 400 may have a nominal wall thickness that does not deviate from the standard thickness of the conduit it is adapted to bridge. The oblong shape of section 400 enables a reduction in the size of the cutout made through a structural member with reference to the width across the face of the structural member, just as shown above for the rectangular section. The area or volume of the conduit remains the same through the alternate profile of conduit section 400 . There is no constriction to flow for fluids between the original round conduit and the oblong section that forms the bridging element for the conduit system through the structural member.
[0038] FIG. 5 is a perspective view of a conduit right-angle elbow 500 with an oblong cross-section according to an embodiment of the present invention. Elbow 500 represents one of the elements of the system of the invention that is provided for routing conduit where 90 degree angles are required in the planned conduit path.
[0039] Elbow 500 is adapted to couple at either or both ends 501 to a straight conduit section such as section 400 described above. Ends 501 are of the same cross-sectional profile as a straight section but are proportionally larger dimensionally so as to act as seats for the conduit section. Elbow 500 may be fabricated from polyvinyl chloride (PVC), ABS plastic, or other suitable plumbing materials. Elbow 500 may be molded. Each end of elbow 500 in this example serves as a female coupler into which the end of a conduit section such as section 400 may be pressed. The fit may be a tight press fit like with round PVC plumbing components. PVC cement or other adhesives may be used to secure the connections. Other materials may be used depending on what materials are suitable for which application.
[0040] FIG. 6 is a perspective view of a conduit elbow 600 with an oblong cross-sectional profile according to another embodiment of the invention. Elbow 600 is similar to elbow 500 described above accept for the angle of presentation. Elbow 600 may be a 15 degree or 30 degree elbow rather than a 90 degree elbow. Like elbow 500 , elbow 600 is designed to accept a conduit section like section 400 into oversize seats 601 . It is noted that the inner dimensioning of elbow ends 601 may be slightly larger than the outer dimensioning of the conduit section of the same profile to enable a hand-press fit like PVC components fit together.
[0041] One with skill in the art of plumbing will appreciate that there may be many different angles of presentation for elbows like elbow 500 and elbow 600 . The inventor illustrates two such elbow configurations and deems them sufficient for the purpose of explaining the invention. It is noted herein that the angle of presentation for elbows may run horizontal or vertical with respect to the oblong cross-sectional profiles of the parts. For example, elbow 500 has an angle that lies in a plane parallel with the major axis of the oblong cross-section. Elbow 600 has an angle that lies in a plane parallel with the minor axis of the oblong cross-section. In this way, many different angle and direction can be incorporated by the system.
[0042] FIG. 7 is a perspective view of a transitional conduit connecter 700 according to an embodiment of the present invention. Connector 700 is adapted to couple to a round conduit at one end 702 and a conduit adapter section having an oblong cross-section at the other end 701 . The materials and manufacturing methods for transitional connector 700 are consistent with those of elbows 500 and 600 described above.
[0043] The oblong cross-sectional profile at end 701 has an equivalent area to end 702 , which has a round cross-sectional profile. The length of transitional connector 700 may vary and the actual transition from a round profile to an oblong profile may be prolonged or shortened by providing a longer or shorter connector. A transitional connector may be used on both sides of a structural member with only a straight conduit adapter section between them to bridge the conduit system through the structural member. No elbows are required in some simple embodiments.
[0044] FIG. 8 is a perspective view of a conduit system 800 routed through a compound frame structural member according to an embodiment of the present invention. A structural member 801 includes three adjacent 2×4s similar to junction A described above in FIG. 1 . An oblong slot is cut through all three members with the major axis of the oblong shape in the direction of the length of the structural members. A straight conduit adapter section 400 of sufficient length is placed through the structure. At one end of the structure section 400 is coupled with a 90 degree elbow 500 of oblong cross-section. A shorter straight conduit section 400 is coupled to the elbow 500 .
[0045] A transitional conduit adapter 700 is coupled to the shorter conduit section 400 at the oblong end and to the conventional conduit (round) at the other end. At the opposing side of the structure, oblong conduit section 400 is shown coupled to elbow 600 . Elbow 600 may, in turn, be coupled to another short or long section 400 and then to a transitional conduit connector like connector 700 .
[0046] In one embodiment of the invention, dependent upon application, conduit sections and connectors having the oblong cross-section can be extended well beyond the limits of a routing junction, becoming an integral part of the original conduit system at a junction point and in general under specific conditions. Conditions that might call for building a significant length of conduit outside of a local junction member might include multiple close junctions through which the system will be routed. In one case a conduit system might be routed through a structural member only at the last few feet of its length such as a drain to the outside, for example. In such a case, the conduit adapter system elements may not be transitioned back to a round cross-sectional profile, rather the outflow portion of the conduit may remain in an oblong shape.
[0047] It will be apparent to one with skill in the art that the invention may be used with original conduit systems that have a cross-sectional profile other than round like a square-tube conduit system. In such a case, different transitional conduit connectors may be provided. One with skill in the art will recognize that for some applications square tubing or conduit is preferable over round. The conduit adapter system may be used with conventional plumbing, draining systems, heating and air systems, and electrical wiring systems.
[0048] It will be apparent to one with skill in the art that the conduit adapter system of the invention may be provided using some or all of the described features and components without departing from the spirit and scope of the present invention. It will also be apparent to the skilled artisan that the embodiments described above are specific examples of a single broader invention which may have greater scope than any of the singular descriptions taught. There may be many alterations made in the descriptions without departing from the spirit and scope of the present invention.
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A conduit adapter system enables routing of conduit through one or more structural members of width W with minimal weakening of the structural member or members, and includes a first section of conventional round conduit on one side of the structural member or members, and a second piece of round conduit on an opposite side of the structural member or members, and a bridge conduit section of sufficient length to pass through the structural member or members, the bridge conduit section having a symmetrical cross-section with a first dimension significantly less than a second dimension, and an area at least as large as the area of the round conduit sections. The bridge conduit section passes through an opening through the structural member or members of substantially the shape of the cross-section of the bridge conduit section such that the first, smaller dimension of the opening is in the direction of width W of the structural member, and is joined by adapter sections to the round conduit on each side of the structural member or members.
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This is a continuation, of application Ser. No. 134,009 filed Mar. 26, 1980, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a composition for use in the production of foamable sheet material, which sheet material may be fabricated into carriers, for attachment to cylindrical containers.
More specifically, the invention relates to a composition which provides a reduction in weight to the sheet material without a corresponding reduction in specific properties of the fabricated carrier.
Carriers used heretofore for attachment below the chimes of cylindrical containers have seen wide spread use by industry and have gained wide acceptance by the consuming public. The light weight character and durability of plastic carriers have provided numerous advantages over paper carriers. However, minimum thickness levels for unfoamed sheet material for fabrication into carriers and handability by machines is required, and the properties of the sheet material were more than necessary.
To overcome the problem of "wasting" properties and/or having to alter machinery to handle thinner sheet material, attempts have been made to moderately or heavily foam the sheet material. As anticipated, another problem arose regarding degradation of properties, such that the carriers produced were not suitable for use, especially with regard to tear propagation properties.
The lightly foamed sheet material of this invention has properties within the specifications required of unfoamed sheet material as a carrier for cylindrical containers. It is lighter in weight, it reduces raw material requirements and provides enhanced tear properties over unfoamed or moderate/heavily foamed sheet material.
One advantage then of the present invention is that a lighter weight sheet material is formed which is usable in the fabrication of carriers for cylindrical containers on existing equipment, without a corresponding loss in properties.
Another advantage of the present invention is the reduction in the amount of raw materials per sheet material or carrier produced.
Yet another advantage of the present invention is improved tear resistance and resistance to propagation of tears once commenced for the sheet material or carrier produced.
One feature of the present invention is the use of a blowing agent mixture to obtain the foamed, lighter weight sheet material when the composition is extruded on existing equipment.
Still another feature of the present invention is that scrap sheet material, obtained during fabrication of the carriers can be chopped and reused in the composition without adversely affecting the properties or performance of the carrier.
SUMMARY OF THE INVENTION
The present invention comprises a composition which provides a lightly foamed sheet material which yields approximately 10 to 20 percent reduction in density over unfoamed sheet material, without a corresponding percentage reduction in properties.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The composition of this invention finds particular utility in the manufacture of sheet material, which is primarily used in the fabrication of carriers for cylindrical containers, of the type shown in U.S. Pat. Nos. 3,773,100 and 3,874,502. Such carriers are made from resilient, deformable, unsupported plastic sheet material, wherein a high percentage of the sheet material remains as scrap, during fabrication of the carriers and wherein the carriers are generally machine applied to containers thus requiring a fast response time between the stretching and the gripping of the carriers about the containers during production applications. Further, the carriers must possess requisite strength to prevent the containers from slipping or dropping from the carrier during handling by the manufacturer, distributors, retailers, and consumers.
These requirements indicate the necessity for any substitute composition to be usable on existing equipment, to keep the properties within specifications required for carriers and to allow scrap material to be reworked within the composition.
Therefore with a foamed structure, it becomes crucial that for a specific density reduction, of about 10-20 percent by weight, over an unfoamed structure, the properties are not proportionately reduced, but remain within established specifications, despite the fact that the foamed structure has cells distributed therein.
Carriers of the type described in the above-mentioned U.S. Patents must possess certain characteristics to be functional during processing, such as during machine application of carriers to containers, and during handling and shipping, when in combination with containers. Some of these characteristics include the properties of impact resistance, coefficient of friction, ductility, tear resistance, environmental stress cracking resistance, elastic modulus, yield stress, yield strain, ultimate strength and ultimate elongation.
The composition of ingredients used in the manufacture of sheet material employed for the fabrication of carriers, in the main, controls and/or establishes the desired balance of the above properties.
The processing equipment used in the manufacture of the sheet material, primarily the extrusion head and advancing rolls, presently have parameters which limit the thinness of the sheet material being produced.
It has been known for some time that the present equipment parameters and present composition parameters produce sheet material on carriers exhibiting properties in excess of actual requirements. This excess of properties per sheet material or carrier represents waste, which heretofore has been reluctantly accepted. Attempts to alter equipment parameters, eg. to reduce the thickness of the sheet material has been met with problems. Likewise, attempts to alter the composition have heretofore not been successful, as all of the properties would not be within specifications.
The present invention takes into account the parameters of the equipment and the difficulties in altering the ingredients of the composition, by introducing a blowing agent and mineral oil into the composition. A slightly foamed sheet material is produced at a thickness within equipment parameters and having properties within established specifications.
By slightly foaming the sheet material, not only is the structure lighter in weight, and a reduction in raw material requirements noted, but the properties of the foamed sheet material do not correspond on a percentage basis to the density reduction. In fact, it has been found, quite unexpectedly, that resistance to tears and to propagation of tears once commenced is markedly improved in the slightly foamed structure.
The slightly foamed structure provides a reduction in density of approximately 10-20 percent over an unfoamed structure of the same thermoplastic polymer. Preferably the density reduction in the slightly foamed structure is approximately 13-17 percent over an unfoamed structure. The density of the foamed structure of the present invention ranges from about 45 lb/ft 3 to about 55 lb/ft 3 , and preferably ranges from about 48 lb/ft 3 to about 52 lb/ft 3 .
The thickness of the structures, foamed and unfoamed are from about 0.014 to about 0.018 inches, the present day parameters of the equipment used to extrude and process the structures.
The slightly foamed structure of the present invention exhibits uniformly distributed or disbursed closed gas filled cells entrained within the structure. The gas filled cells are extremely small (of the order of magnitude of about 200 microns) diameter and they are barely visible with the naked eye. The surfaces of the foamed structure appear to be as smooth and uninterrupted as the unfoamed structure, thereby exhibiting similar aesthetic qualities of the latter, including resistance to soiling.
The tiny cells within the structure apparently disrupt the normal planes of tear in an unfoamed structure. Unfoamed structures, eg. of extruded polyethylene, exhibit oriented molecules and tearing normally occurs alongside these molecules. By slightly foaming a structure, the bubbles apparently cause disruptions along the planes of tear and thus alters the orientation of the molecules. This alteration apparently causes applied stress to the foamed structure to dissipate within the structure, thus enhancing resistance to tear.
The condition that the cells be closed and entrained within the structure is in addition to other conditions--the bubble size and the density of the bubbles. If the cell size or bubble size is allowed to grow and expand to the point of bursting, properties, especially resistance to tear are adversely affected. Likewise, if the density of the cells increases beyond about 100-500 cells/cm 3 , the resistance to tear is adversely affected.
Generally, the cell size and density of the cells are a function of the amount and of the nature of the blowing agent or mixture of blowing agents employed within the composition. The temperature at which the blowing agents release an inert gas, such as nitrogen, is a controlling factor, thus the temperatures generated during extrusion must be tightly controlled. For a composition employing a blowing agent which releases an inert gas at about 325° F., the temperature range during extrusion must be controlled to about ±5° F.
The composition of the present invention which enables the production of slightly foamed sheet material for use in fabrication of carriers is represented as shown below.
EXAMPLE I
______________________________________Ingredients Amount (pounds)______________________________________Low density thermoplastic polymer 90-110Blowing agent mixture 0.05-0.4Mineral oil 0.05-0.2______________________________________
EXAMPLE II
______________________________________Ingredients Amount (pounds)______________________________________Low density thermoplastic polymer 95-105Blowing agent mixture 0.15-0.25Mineral Oil 0.07-0.13______________________________________
The low density thermoplastic polymer may be polyethylene and copolymers thereof or polypropylene and copolymers thereof. Generally, a low density polyethylene polymer having a number average molecular weight (Mn) of from about 22,000 to about 30,000 is preferred. Such polymers are commercially available from Union Carbide Corp. and U.S. Industrial Chemicals Corp.
The blowing agent mixture comprises blowing agents which release an inert gas at about 300° F.-400° F., such as azodicarb-onamides commercially available as "Kempore", and additives such as Metal Oxide as contained in commercially available in Kempore Mc.
The mineral oil may be any laboratory light grade oil commercially available from Standard Oil Co.
EXAMPLES III-V
______________________________________ Amounts (pounds)Ingredients III IV V______________________________________Low density polyethylene polymer 100. 100 100Blowing agent mixture 0.2 .25 .15Mineral Oil 0.1 .13 .07______________________________________
The mixing procedure for the above examples comprises combining the polyethylene polymer, generally used in pellet form, and the mineral oil so that the latter coats the former. Thereafter the blowing agent mixture, generally used in powder form, is combined with the coated pellets to evenly distribute the ingredients of the mixture.
The mixtures of the above examples were fed to an extrusion machine previously used to produce unfoamed sheet, wherein the temperature range during extrusion was maintained within ±5° F. of the gasifying temperature of the blowing agent mixture. Foamed sheets were formed and carriers for containers were obtained therefrom, which were machine applied to cylindrical containers with favorable results. The densities of the resulting foamed sheets for Examples III, IV, V, were 50 lb/ft 3 , 45 lb/ft 3 , and 52 lb/ft 3 respectively.
During the fabrication of carriers from the sheet material much scrap is generated, i.e. about 75-80% scrap is generated. Because of this feature, the scrap must be reworked into the basic composition for the material to be feasible in industrial applications. Generally, the scrap is chopped, and is called "fluff" in the industry. This fluff is then added to the basic composition mixture and the mixture and the fluff are combined in a blender prior to being fed to an extrusion machine as described above.
It has been found that the chopped scrap sheet material can be present in the composition in an amount of from about 10.0 to about 90.0 percent by weight of the total weight of the thermoplastic polymer and the chopped scrap sheet material. Preferably, the chopped scrap sheet material is present in an amount of from about 60.0 to about 80.0 percent by weight of the total weight of the thermoplastic polymer and the chopped scrap sheet material. There appears to be no limitation on the number of times the scrap may be reworked into the composition.
The following examples represent compositions of this invention, employing chopped scrap sheet material, used in the production of slightly foamed structures.
EXAMPLE VI
______________________________________Ingredients Amount (pounds)______________________________________Low Density Thermoplastic Polymer 10-90Chopped Scrap Sheet Material 10-90Blowing Agent Mixture 0.02-0.4Mineral Oil 0.01-0.2______________________________________
EXAMPLE VII
______________________________________Ingredients Amount (pounds)______________________________________Low Density Thermoplastic Polymer 20-40Chopped Scrap Sheet Material 60-80Blowing Agent Mixture 0.05-0.15Mineral Oil 0.02-0.07______________________________________
EXAMPLES VIII-X
______________________________________ Amount (pounds)Ingredients VIII IX X______________________________________Low Density Thermoplastic Polymer 30. 40. 20.Chopped Scrap Sheet Material 70. 60. 80.Blowing Agent Mixture 0.07 .15 .05Mineral Oil 0.03 .07 .02______________________________________
The mixing procedure for the above examples comprises combining the polyethylene polymer and the mineral oil, so that the mineral oil coats the polymer, usually in the form of pellets to assure that the subsequently combined blowing agent mixture is substantially uniformily applied to the oil coated pellets. The blowing agent mixture is generally employed in a powder or granular form, thereby requiring substantial mixing with the oil coated pellets. Subsequently, the mixture of polymer, oil, and blowing agent is combined with chopped scrap sheet material (fluff) for blending or mixing. Thereafter, the blended ingredients are fed to an extruder to produce a foamed structure. Carriers of the type hereinabove described and referred to were fabricated from the foamed structures, and the carriers were machine applied to cylindrical containers in a satisfactory manner. The properties of the foamed carriers were within the prescribed specifications of unfoamed carriers, and they matched the performance of unfoamed carriers produced from low density polyethylene polymer. However, the foamed carriers were found to have better resistance to tear and better resistance to propagation of tear once commenced. The densities of the resulting foamed structures for Examples VIII, IX, X were 50 lb/ft.sup. 3, 48 lb/ft 3 , and 52 lb/ft 3 respectively. The scrap sheet material thus formed during fabrication of the foamed sheet of the above examples into carriers can again be chopped and reused.
Modifications of the disclosed compositions and sheet material produced therefrom may be resorted to without departing from the spirit and scope of the appended claims.
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A foamed low density polyethylyne sheet material is provided which finds utility in the fabrication of carriers for attachment to cylindrical containers. The sheet material is formed from a composition comprising low density polyethelyne polymer, a blowing agent mixture, and mineral oil, on commercially available extrusion equipment, and in proportions sufficient to obtain a 10-20 percent reduction in weight without a corresponding reduction of specific properties.
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BACKGROUND OF INVENTION
This invention relates to the field of devices that are used to enable the user to slide or glide across surfaces such as snow and ice. The device that is particularly suited for this invention is a snowboard. As one skilled in the art will recognize, an application of this invention can extend further than just to the field of snowboarding, and as such would be covered by the concept and spirit of this invention.
DESCRIPTION OF THE ART
This invention accomplishes some of the attributes desirable for a user to have a device that contains both damping characteristics and a cantilever stiffening aspect in one device. It is desirable for those who participate in the activity of snowboarding to have a board that is soft or damping around the edges, which will keep the snowboard conforming to the terrain, while at the same time being able to have the snowboard “spring” back to its natural state after being bent in both directions around half-pipes, contours or steel pipe rails. Snowboarding is different from skiing as there is more demand for freestyle jumping and riding on the edge of the snowboard. Skiing demands more bending of the ski in a concave direction with extreme flexural characteristics, as skiers tend to ride moguls, contours and uneven terrain, seeking the ski to smoothly transition between valleys and peaks. Snowboarding on the other extreme has more jumps and skateboarding types of terrain where the snowboard needs to “grab” the surface, damping, but also need to provide “spring” or lift when jumping from the edge of half-pipes and rails. Also a snowboard is more likely to be subjected to flexural and compressive forces at the same time and then the opposite forces will be subjected on the board in the next immediate moments. Snowboards need to adapt to bending moments in both the vertical and horizontal planes which are constantly and rapidly changing.
The prior art for those devices which can be used for gliding across snow can generally be described as layering materials of various properties longitudinally along the vertical axis of the device. U.S. Pat. No. 4,412,687 issued to Andre on Nov. 1, 1983 discloses a ski that is laminated with high tensile strength materials, rods and filament bundles. The goal is to increase the rigidity and bending strength of the ski. U.S. Pat. No. 4,706,985 issued to Meatto on Nov. 17, 1987 also discloses the basic concept of layering materials to obtain the desired characteristic of the device. Meatto combines both circular rods and sheets of various components to increase flexural response and compressive structural strength of the ski. Snowboards though need to be soft and flexible not stiff as skis. The early snowboards were built as having the same internal material composition of skis. But as snowboarding developed into a different style of sport from skiing, the design of snowboards have started to develop to adapt to this change in use. The prior art of snowboard design has followed the designs of both skis and skateboards.
Snowboards have three distinct sections, the main body, the front tip or nose, and the rear tail. Each is shaped differently and in snowboards the tip and tail are significantly larger in width than is the body than in skis. Snowboards are ridden with the center of gravity of the user generally over the center of gravity of the snowboard, where on skis the center of gravity is shifted toward the tail of the ski. The skier faces the along the axis of motion, where the snowboarder is transverse to the axis of motion, needing a wider plane in order to attach themselves to the snowboard and creating the need for torsional movement rather than axial movement. Generally, this torsional movement is generated on the edge of the snowboard and thus snowboards are now built with this recognition of movement in mind. Prior art shows snowboards developing softer edge material so that the snowboard is easier to carve in long turns. Patent Publication 2002/0105165 for DeRocco published Aug. 8, 2002 details this concept of varying edge properties by using ABS or other relatively rigid materials in different shapes and thicknesses in the core of the board disclosing that some riders like a stiffer board. U.S. Pat. No. 6,499,758 issued to Fournier on Dec. 31, 2002, discloses a complex series of angles and grooves designed to reduce the compression forces necessary to bend the board. U.S. Pat. No. 6,382,658 issued to Stubblefield on May 7, 2002 discloses a plurality of cross-sections and thicknesses of the core to create an improved turning performance. These are both very complex to design and difficult to manufacture and thus they become very expensive and custom to a particular need of a rider in a particular situation, long smooth turns of Fournier to the sharp tight turns of Stubblefield. It would be desirable for a snowboard to be able to adapt to a multitude of different situations as they present themselves while snowboarding down a mountain slope. U.S. Pat. Nos. 6,520,530 and 6,105,991 issued to Dodge et al on Feb. 18, 2003 and Aug. 22, 2000 respectively, addresses the issue of having various directions of the strength of materials so that the material's direction of strength is located along the areas of greatest stress on the snowboard. This is very complex and arduous task of aligning materials for a particular style of riding. These patents claim vertically laminated members which are non-parallel to the core axis and anisotropic structures oriented so that the principal axis is not in alignment with any of the core axis. It would be desirable to produce a snowboard that is can be readily manufactured that would contain the positive attributes of the prior art such as varying degrees of flexibility and response but are more easily adaptable and manufacturable. It would be advantageous to be able to have a snowboard that combines the rider's desires as well as the demands of the conditions available for him to ride. It would be desirable to have a snowboard that is customizable in a short amount of time and can be mass produced for varying levels of ability and that uses the same concepts and materials.
This invention derives it's uniqueness from a combination of responsive materials and a cantilever inspired spring return system. The main uniqueness of this invention is that it treats the core, the tail and the tip as three separate entities which enable the invention to focus on the different materials necessary for each part of the board and yet function as a unit and have the different characteristics in the unique areas of the snowboard. The choice of materials is developed about the nature of the conditions during use and construction of the snowboard. Materials must have consistent properties through-out the manufacturing process including the cooler temperature when the snowboard is made and used, yet do not have their properties depreciated during the pressure, bending and heating processes during construction. Where flex is required in the tail and tip, a softer material is used, and while the core of the body is stiff for responsiveness, the edges are softer. The use of carbon fiber stiffening members “spring” the snowboard back to it's natural state quickly, so that the snowboard is ready to absorb the next grueling round of stresses around the next corner or half-pipe jump. This invention can be customizable by adjusting the stiffness of the snowboard by adding or subtracting stiffening members or by adjusting the thickness of the stiffening member.
DESCRIPTION OF FIGURES
The following figures are included to graphically detail the invention.
In FIG. 1 , the interior core, tail and tip of the snowboard is shown.
In FIG. 2 , a profile of the snowboard is taken directly down the vertical centerline or section B-B as shown in FIG. 1 . The entire snowboard is shown with the top and bottom layers along with the core.
In FIG. 3 , the snowboard is shown on a horizontal profile, cut along section A-A. In this figure, the snowboard is shown with only 1 stiffening member on each side of the core.
In FIG. 4 , the snowboard is shown on a horizontal profile, cut along section A-A. In this figure, the snowboard is shown with 2 stiffening members on each side of the core, located equidistant from the vertical center of the board.
In FIG. 5 , the detail of the stiffening member and associated channel is shown in profile view.
In FIG. 6 , is a layered view of the snowboard, where each layer is shown by hatch pattern along with the stiffening member. Detail of the dovetail joint is also seen with this figure.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 , the body 2 of the snowboard 1 is shown. Body 2 comprises tip 3 , tail 4 , core 5 , at least 2 stiffening members 6 , with an equal number of channel 7 corresponding to stiffening members 6 , and perimeter edge 8 . Core 5 is defined by right vertical plane wall 13 and left vertical plane wall 14 and upper horizontal plane wall 11 and lower horizontal plane wall 12 . Core 5 is also defined by a front side of core 17 and a rear side of core 18 which extends in the horizontal plane between right vertical plane wall 13 and left vertical plane wall 14 . Central riding surface 40 is defined as that area between the riders feet as they are attached via mountings holes 19 to the board 1 , surface 40 extending from right vertical plane walls 13 through the vertical axis B-B to left vertical plane wall 14 . Riding surface 40 is characterized as having an equal distance or thickness between front side 17 and rear side 18 at corresponding points through out core 5 . Right edge 13 and left edge 14 are concavely circumscribed about an arc of a circle whose radii depends upon personal users preferences. Generally, a radius of approximately 1000 cm is used. Core 5 has a vertical axis of core B-B which is described as being the longitudinal line which is equidistant from corresponding points in the horizontal plane along said right edge 13 and said left edge 14 . Vertical axis of core B-B is along the vertical axis of rotation. Core 5 has a horizontal axis of core A-A which a latitudinal line described as intersecting said vertical axis of core B-B at a right angle and is equidistant from corresponding points on upper horizontal plane wall 11 and lower horizontal plane wall 12 . Midpoint 31 is defined as the intersection of vertical core axis B-B and horizontal core axis A-A. Front side of core 17 is has a reduction in thickness contour 32 tapered commencing at the distal end of mounting holes 39 , tapering toward horizontal plane walls 11 and 12 . The reduction of thickness along contour 32 extends at a constant rate creating an equal thickness of the core extending from right edge 13 and said left edge 14 . Core 5 has a thickness at midpoint 31 of between 4-10 mm, preferable 6-8 mm. Core 5 has a thickness of between 1-6 mm at horizontal plane walls 11 and 12 , preferably 2-4 mm. In this invention, core 5 follows contour 32 from 6 mm to 3 mm in thickness with a slight radius. Contour 32 can have a slope that contains a radius or has a straight slope toward its termination point at the horizontal walls. Tip 3 and tail 4 are joined with equal thickness to horizontal plane wall 11 and 12 . Upper horizontal plane wall 11 and lower horizontal plane wall 12 are adapted for maximum bonding adhesion by increasing the surface area of the bond between core 5 and tip 3 and core 5 and tail 4 . In this invention, a dovetail design 20 is used to accomplish this goal of maximum adhesion. This invention is not limited to a particular design to maximize the surface area for greater adhesion. The goal is to create the maximum necessary bond between said core 5 and tip 3 and core 5 and tail 4 . Bonding means are used to enhance dovetail 20 adhesion to tip 3 and tail 4 . The distance between said front side of core 17 and rear side of core 18 at any one point of core 5 is predetermined by the style of use of said board 1 . This invention is not limited to specific contour angle or lack thereof. Binding mounting holes 19 are located along vertical axis of core B-B, corresponding to a predetermined pattern of inserts that are necessary for the attachment of bindings to said board 1 after completion of bonding of the layers. The pattern of inserts matches the configuration of mounting holes of the bindings, which usually conforms to the industry standards as for location and degree of angle of the mounting to the vertical axis of the snowboard. Binding mounting holes 19 are threaded inserts whose exterior is adapted for maximum adhesion during the bonding process in this invention. Core 5 can be made from wood, such as birch, aspen, balsa or other lightweight woods.
Right edge 13 and left edge 14 has circumscribed thereabout a perimeter edge 8 . Perimeter 8 is equivalent in height as is the height of edge 13 and 14 and is bonded to edge 13 and 14 using bonding means. Perimeter edge 8 follows the radius of right edge 13 and left edge 14 . Perimeter edge 8 extends in the horizontal plane a pre-determined distance based on desired board characteristics. Perimeter edge 8 is made of an isotropic material which is invariant with respect to any direction. This material must have stability of the characteristics throughout the range of temperatures for where board 1 is to be subjected thereto and also does not have any degradation of material characteristics when subjected to bonding means. In this invention, Celluarized or Expanded polyvinylchloride is used with of density of between 0.35 and 1 g/cm 3 , preferably 0.55 to 0.75 g/cm 3 . Perimeter 8 edge extends beyond upper horizontal plane wall 11 following tip cutin radius 41 , terminating at the transition between the radii of right edge 13 and left edge 14 and the tip radius 43 . Perimeter 8 edge extends beyond lower horizontal plane wall 12 following tail cutin radius 42 , terminating at the transition between the radii of right edge 13 and left edge 14 and the tail radius 44 as seen in FIG. 1 .
Tail 4 is defined by a distance from the lower horizontal plane wall 12 to the apex of tail radius 38 . Tail 4 constructed of material similar in physical and thermal characteristics to the material used in perimeter edge 8 and is connected to tail cutin radius 42 using bonding means. Tail radius 44 is defined as the curvature needed to connect the termination of right edge 13 and left edge 14 to apex 38 . Distance from lower horizontal plane wall 12 to apex 38 is determined by the bending characteristics desired of board 1 by the riders. In this invention, the distance is approximately 20-24 cm. Tail 4 contains at least one tail extension channel 37 which similar in shape and dimensions as channel 33 and constitutes a continuation of channel 33 from core 5 to tail 4 . There will exist at least an equal number of tail extension channel 37 corresponding to top channel 33 and bottom channel 34 that exist on core 5 . Tail extension channel 37 will vary in length depending upon the particular performance characteristics required of board 1 . Tail extension channel 37 will vary from 50% to 90% of the distance from lower horizontal plane wall 12 to apex 38 . The longer the channel, the stiffer the tail of the board, which is better for turning but not for jumping or rail-riding.
Tip 3 is defined by a distance from the upper horizontal plane wall 11 to the apex of tail radius 36 . Tip 3 constructed of material similar in physical and thermal characteristics to the material used in perimeter edge 8 and is connected to tail cutin radius 41 using bonding means. Tail radius 43 is defined as the curvature needed to connect the termination of right edge 13 and left edge 14 to apex 36 . Distance from upper horizontal plane wall 11 to apex 36 is determined by the characteristics of board 1 by the riders. In this invention, the distance is approximately 26-30 cm. Tip 3 contains at least one tip extension channel 35 which is similar in shape and dimensions as channel 33 on core 5 and constitutes a continuation of channel 33 from core 5 to tip 3 . There will exist at least an equal number of tip extension channel 35 corresponding to top channel 33 and bottom channel 34 that exist on core 5 . Tip extension channel 35 will vary in length depending upon the particular performance characteristics required of board 1 . Tip extension channel 35 will vary from 50% to 90% of the distance from upper horizontal plane wall 11 to apex 36 . The longer the channel, the stiffer the tip of the board, which is better for turning but not for jumping or rail-riding. Percentage distance for tip extension channel 35 and tail extension channel 37 can be and usually is different due to performance characteristics required by the individual board. This invention focuses on the ability to rapidly change the performance of the board easily and without costly manufacturing changes.
FIG. 5 details the channel and stiffening members. There are at least two channel 33 each having the depth equivalent to the thickness of stiffening member 6 . FIG. 5 details just the upper half of core 5 for clarity. Channel 33 is defined by channel sides 21 and channel bottom 22 . Stiffening member 6 is composed of a polymer based material with stiffening agents embedded therein, to produce a lightweight material with a high resistance of elastic deformation whereby the stiffening member will act like a piece of spring steel like material returning the member to it's original shape and size immediately after the action of deformation. Stiffening member 6 is placed directly onto channel bottom 22 and in proximal contact with channel sides 21 . Bonding means is used to secure stiffening member 6 to channel sides 21 . Channel 33 is milled or routed into the surface of core 5 as shown in FIGS. 3 and 4 . FIG. 3 describes a top side channel 33 which contains two channel sides 21 that are perpendicular to front side of core 17 and a lower side channel 34 also contains two channel sides 21 that are perpendicular to rear side of core 18 . In this embodiment of the invention that is detailed in FIG. 3 , there is one top side channel 33 and one lower side channel 34 , the horizontal center of each channel being located along the vertical axis of core B-B. The length of channel side 21 can be equal for top side channel 33 and lower side channel 34 or the length channel side 21 may be different between top side channel 33 and lower side channel 34 , should the rider want to have a different rebound response between the flexation and compression of the stiffening members in the channels. For example, a rider who wishes to have board 1 that has a soft feel for trick riding, might wish to have a board that will bend more easily from the top of the board, but would wish for a stiffer bottom of the board to return or spring the board back to it's natural position. It is the characteristic of this invention to always have an equal number of said channel 33 inlaid on said front of core 17 and as there is channel 34 inlaid on said rear of core 18 . FIG. 4 shows the addition of one top side channel 33 and one lower side channel 34 for a total of 2 on each side. In this embodiment of the invention, each front side channel is symmetrically placed about the vertical axis of core B-B. Each lower side channel is symmetrically placed about the vertical axis of core B-B directly opposite of the front side channel. It is the theory of this invention that the opposing forces supplied by the opposing stiffening members, one being in tension while the other is in compression, is what gives this invention the desired characteristics. This does not preclude the adaptation of variations in placement of the stiffening members in relation to one another, as that would be within the spirit of this invention. In this embodiment, said channel 33 in inlaid through the entire vertical distance of core 5 extending beyond said upper horizontal plane wall 11 and lower horizontal plane wall 12 . It is within the spirit of this invention to reduce to length of said channel 33 to lengths less than that of the vertical distance of said core 5 .
Core 5 , in combination with bondly attached tip 3 , tail 4 and perimeter edge 8 and along with bondly attached stiffening members 6 , constitutes body 2 . Body 2 is laminated to bottom layer 45 using bonding means. Bottom layer 45 is defined by upper bottom layer 49 and lower bottom layer 48 and bottom layer edge 50 , bottom layer 45 being made of Ultra-High Molecular Weight polyethylene. Circumscribed about bottom layer edge 50 is metal carving extension rail 46 which is bondly attached to edge 50 using bonding means. Rail 46 is a flexible metallic piece that when sharpened after installation creates an edge that is able to carve into the solid ice facilitating turning of board 1 in icy conditions. The interface between edge 50 and rail 46 differs in shape corresponding to the type of rail 46 used. In this invention, FIGS. 3 and 4 describe a rail 46 which has an inclined angle, increasing the bonding surface area, which dictates the corresponding angle of edge 50 . Bottom layer edge 50 with the bonded rail 46 proscribes a profile in the horizontal plane that conforms to the profile of body 2 . Upper bottom layer 49 , along with rail 46 is covered with bonding strengthening material 47 and bonding means. Body 2 is placed on top of upper bottom layer and accompanying bonding materials.
Top layer 51 is profiled to match body 2 . Top Layer 51 is modified to accept mounting holes 19 . Body 2 is layered with bonding strengthening material 47 and bonding means and then top layer 51 . Board 1 is then subjected to pressure and heat to cure the bonding material and to shape the vertical profile of the board as shown in FIG. 2 . After cure, vertical edge angle 52 is produced. Grinding means are used to shape a 45 degree angle emanating from the upper outer corner 53 of rail 46 , shaping the 45 degree angle in toward midpoint 31 along the entire outside surface of the rail 46 . After processing the angle 52 , board 1 is ready for final preparations for use. Bottom side of bottom layer 48 is roughed up using low grit sandpaper or similar device so that it is adapted to receive a waxing compound, which decreases friction between the board 1 and the snow. Upper layer of top layer 51 has applied thereupon multiple layers of liquid polymers, such as UV-stabilized acrylics, that will enhance the visual attributes of board 1 and will increase the surface hardness to prevent damage to the top layer of board 1 .
Bonding means used in the construction of board 1 incorporate those characteristics which will provide superior adhesion of unlike materials, can be strengthened using bi-directional or omni-directional reinforcing materials, such as glass, carbon, metallic or similar natural or manmade fibers and can withstand temperature deviations typical where board 1 will be manufactured and used. In this invention, epoxy 54 is used as the bonding agent along with glass fiber mesh material, described as bonding strengthening material 47 . The bonding material is subjected to heats up to 80 degrees Celsius and pressures up to 80 pounds per square inch during the curing process. The curing process is done in a press where the concave and convex shapes of the board are produced using opposing dies.
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Though the sport of snowboarding is not new, it has taken many years to understand the specific characteristics which are required for making snowboards. There is better understanding of the dynamic bending properties needed for current riders, especially for the competition driven rider whose demands require boards with different tip, tail and middle characteristics. Early snowboard designers understood the use of snowboards as articles for gliding down a snow covered slope making long curving turns, where tips and tails would be as stiff as the middle core. But now, the boards are jumped into the air, launching from half pipes edges and sliding down steel rails, requiring different flex contours. Snowboards are now required to be very flexible yet elastic being required to bend convexly and concavely, yet springing back to their shape immediately, with some riders wanting stiff tips or soft tails or a combination of both.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This utility patent application claims the benefit of and priority to U.S. Provisional Application 62/165,246, filed on May 22, 2015, the entirety of which is incorporated herein by reference.
DESCRIPTION OF THE RELATED ART
[0002] Pressure-squeeze type tampers are typically used in tie gangs during maintenance, such as when ties of a rail system are being replaced. However, as these tampers use opposed, vibrating tamping bars, new ballast is not placed under the ties. Rather, these devices simply squeeze the existing foul ballast under the ties, often without any real compaction, depending on how fast and how many insertions the operator uses. This may result in new ties often not being in bearing through several surfacing cycles, essentially transferring the load to the remaining, possibly weaker ties, negating much of the benefits of the spot tie renewal and resulting in weak and rough riding track.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0004] FIG. 1 is a schematic, front view of an example embodiment of a tie gang ballast replacer/compactor.
[0005] FIG. 2 is a schematic, plan view of the embodiment of FIG. 1 .
[0006] FIGS. 3-6 are schematic, side views of the embodiment of FIG. 1 .
[0007] FIGS. 7-14 are schematic views of another example embodiment of a tie gang ballast replacer-compactor showing the system in operation in more detail (thus, depicting another embodiment of a method).
DETAILED DESCRIPTION
[0008] Reference will now be made in detail to the description of the disclosure as illustrated in the drawings. While the disclosure will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed herein.
[0009] In this regard, various embodiments of a Ballast Replacer-Compactor may remedy one or more of several problems associated with the current use of pressure-squeeze type tampers in tie renewal gangs. In particular, in some embodiments, a Ballast Replacer-Compactor (BRC) may work on a different principle, altogether. A BRC ( 100 ) (such as the embodiment depicted in FIGS. 1-6 , for example) may replace a large portion of the ballast bed under the target tie by first engaging the crib ballast with the compactor bars, which are facing downward. Often this crib stone is the freshly dumped, clean ballast required for a raise that ideally will go under the ties. Even when not freshly dumped, the crib ballast is invariably in better condition than the ballast under the ties, as it has not been broken and abraded by train action and is essentially undamaged. The compactor bars, following a downward arcuate path, push this clean stone down through the crib and under the ties, displacing the foul ballast, which flows up into the crib behind the target tie. That crib was partially evacuated by the compaction of the previous tie. The compactor bars first pass nearly completely under the target tie; on further insertions, the path is shortened as the ballast pushed under the tie becomes consolidated. Pressure sensing circuits control this variation in the compaction strokes. This novel and effective method assures that 1) a large volume of clean ballast is placed under the ties; and, 2) that the ballast is properly and fully compacted so the new ties are in full, effective bearing Immediately.
[0010] The BRC has a crib compactor plate mounted behind the target tie; this vibrating plate is deployed and compacts the crib ballast behind the target tie as the compactor bars on the front side are withdrawn. This assures that the cribs are tight and providing the required lateral and longitudinal resistance needed in freshly disturbed track to have adequate stability, especially in hot weather to avoid sun kinks.
[0011] As the crib compactor and compactor bars, on opposite sides of the target tie, do not engage the ballast at the same time, the ballast is not trapped between two high-pressure, vibrating, squeezing faces that tend to break and destroy the ballast—as the current pressure-squeeze tampers often do.
[0012] In some embodiments, a variable rate of oscillation (OPM) frequency for the compactor bars and the crib compactor may be used, as higher frequencies aid insertion into the ballast but lower frequencies are more effective during the compaction portion of the cycle. The BRC may be fitted with variable-rate oscillation vibrator motors and can change the higher frequency OPM during the stroke to push the crib ballast down through the surrounding ballast and then reduce the OPM's for better compaction. The compactor pressure may be variable and can be set by the operator for optimum compaction of the ballast under the target tie without humping the track.
[0013] The result of these innovations is a Ballast Replacer-Compactor that may, in some embodiments, provide the proper consolidation and support under spot-renewed crossties after the first pass, resulting in reliable, more uniform ballast support and higher quality, safer track. This technique can be scaled and speeded up to provide the same valuable benefits to production surfacing/tamping equipment, resulting in longer intervals between surfacing cycles and less geometry degradation and rough track in all tracks, including heavy-tonnage areas of operation.
[0014] An example embodiment is depicted in the illustrations of FIGS. 1-6 and includes the following representative components:
[0015] Reaction mass ( 1 )—two are provided, with each mass weighing approx. 2,000-2,400 lbs. per Replacer/Compactor Work Head. The reaction mass ( 1 ) provides the downward reaction force required to push the crib ballast ( 14 ) down and compact it without having to anchor to the rails ( 13 ) or humping the track. The mass ( 1 ) and attached components of Replacer/Compactor Work Head can be raised and lowered and also traversed like a switch tamper to provide full compaction coverage of bearing area (see plan view FIG. 4 and other views). The mass ( 1 ) is fitted with a laterally movable frame ( 23 ) that is positioned by a hydraulic cylinder ( 24 ) to slide laterally on guide bars ( 25 ), which in turn are mounted into weld frame ( 26 ). Weld frame ( 26 ) is movable vertically on guide rods ( 27 ) mounted to chassis ( 22 ), with the power being provided by hydraulic cylinders ( 28 ).
[0016] Hydraulic cylinder ( 2 )—four are used, one per tamping bar. The hydraulic cylinders provide closing action to compactor bars. Hydraulic cylinder ( 2 ) is controlled by sequence and pressure sensors to provide the arcuate (e.g., elliptical) path of compactor bars and proper compaction forces. The range of forces varies by ballast type and condition, and can be field adjusted.
[0017] Compaction head frame ( 3 )—two are attached to each mass ( 1 ). Frame ( 3 ) provides mountings and pivots for working components of the compaction head.
[0018] Crib compactor ( 4 )—comprised of four sections, two each in the gage of track and one each on field side of both rails ( 13 ). Each section is fitted with a free-body vibrator ( 5 ) that compacts the crib ballast ( 14 ) after the tie bed ballast has been compacted. Each section is supported and deployed by linkage ( 6 ) and lifting cylinders ( 7 ). In some embodiments, commercial concrete vibrators may be used to provide oscillation at the correct, variable OPM for the ballast type being worked.
[0019] Compactor bars ( 8 )—two per compaction head, with one on the gage side, one on the field side of each rail. Compactor bars ( 8 ) are driven by eccentric drives ( 9 ) and closure activated by cylinders ( 2 ). Compactor bars ( 8 ) have replaceable pusher faces ( 10 ) that are shaped to clear ties during arc of travel and are easily replaceable for wear. The pusher faces are supplied in different shapes to suit the type of ballast (e.g., large gradation, sharp stone vs. gravel, for instance).
[0020] Oscillation eccentric drive ( 9 )—each compactor bar ( 8 ) pivots from an eccentric drive, which is driven by a variable-speed hydraulic motor (not shown). In this embodiment, each eccentric drive provides up to ¼ throw at OPM variable from 1,000 to 3,600 OPM (optimum OPM for pushing and compacting actions are programmed into the control system depending on ballast type).
[0021] Pusher faces ( 10 ) are in position where replacer/compaction cycle begins when operator lowers Replacer/Compaction work head to “start” Position 3. Tie lock jaws also engage ties at this position.
[0022] Shaded area ( 11 ) shows “swept” area covered by the pusher faces ( 10 ) as they pass through their paths from insertion into the crib. In some embodiments, width is 7″ +/−1″, maximum width that is compatible with efficient ballast moving and compacting. In FIG. 4 (plan view), shaded areas ( 31 ) show the lateral path the compactor bars follow as the width of the bearing portion of the tie beds is progressively tamped, requiring a minimum of three compactor bar insertions to cover the whole area to be tamped.
[0023] Patterned areas ( 14 ) in FIGS. 1 and 3 show the crib ballast, which is the ideal material to be placed under the ties, as the crib ballast is invariably cleaner and less damaged than the ballast directly under the ties, and is therefore more desirable as a tamping material. Crib ballast ( 14 ) varies in thickness, but is usually at least 5″ thick.
[0024] Crossties ( 12 )—7″×9″, conventional wood ties at 18″ OC shown. Other tie types and configurations may be used. Concrete ties are spaced differently but are handled similarly. It should be noted that an adjustment of the compaction arc may be required to provide clearance for oversized ties.
[0025] Chassis ( 22 )—includes flanged wheels ( 30 ) fitted to axles, which support a frame fitted with various components, such as an engine, hydraulic and pneumatic pumps and compressor, and an electrical system, and having an operator control station, propulsion system, brakes, etc.
[0026] Tie locks ( 29 )—two sets are used, mounted on the field side of rails ( 13 ). The tie locks ( 29 ) engage ties ( 12 ) to prevent sliding induced by asymmetric pressure such as that exerted by the compactor bars on only one side of the ties, and also the crib compactor forces on the ballast in the trailing crib. The ties are clamped by two fixed jaws ( 15 ) and two movable jaws ( 16 ), activated by two hydraulic cylinders ( 17 ). These components are mounted on two welded steel frames ( 18 ), which in turn are supported by four pivotally mounted arms ( 19 ) actuated vertically by two hydraulic cylinders ( 20 ) and are attached to a bracket ( 21 ) on the front of the chassis ( 22 ).
[0027] Shaded area ( 31 ) shows the width across the track that the pusher faces ( 10 ) and crib compactors ( 4 ) and ( 5 ) can reach and compact effectively.
[0028] Fouled ballast ( 32 ) is the ballast section underlying the crossties ( 12 ) that is often badly fouled.
[0029] Phantom outlines ( 33 ) showing mass ( 1 ), pusher faces ( 10 ), and crib compactor ( 4 ) at their innermost position and also shows the width across the track that can be tamped effectively.
[0030] The aforementioned components are shown in the deployed condition with the track-engaging tool elements engaging the ballast and ties in the work position in FIGS. 1, 2 and 3 . The components are shown in FIG. 4 in the “clearing” or travel position, in which the components are up out of the track in position to allow safe, speedy travel over the track. In some embodiments, all of the tool elements that can drop down and foul the track are fitted with safety pins and locks to prevent inadvertent contact with the track during the travel mode.
[0031] For convenience and speed during operation, there are three main positions of the track-engaging tool elements: Position 1—as shown in FIG. 4 with all tool elements safed-up and in the clear; Position 2—as shown in FIG. 5 with the tool elements poised at a lower position so only a small movement (<10″) is required to engage the track elements in Position 3; and, Position 3—as shown in FIGS. 1 and 3 with all track-engaging tool elements in their respective working positions at the start of the replacement/compaction cycle.
[0032] Operating Sequence
[0033] The operator propels the BRC to the worksite and then places the tool elements into Position 2 as noted above. The BRC is then aligned with the first target tie to be tamped and the major tool elements are lowered, including the mass ( 1 ) and the tool elements attached (i.e., the compactor bars ( 8 ), the tie lock assemblies ( 29 ) and the crib compactors ( 4 ), as well as the associated sub-elements described above).
[0034] The tool elements are automatically sequenced with electro-hydraulic controls to reduce operator effort and speed up operations. The operator chooses at what rate to traverse the compactor bars ( 8 ) and the crib compactors ( 4 ) to reach good ballast consolidation as this will vary depending on the type ballast and how much it has been disturbed during old tie removal and new tie installation. When the compactor bars ( 8 ) have completed each cycle of compaction of the tie bed ballast, the crib compactors ( 4 ) are cycled on to compact the crib on the trailing side of the target tie ( 12 ).
[0035] When the compactor bars ( 8 ) and crib compactors ( 4 ) have completed the compaction of the tie bed and crib ballast, the track-engaging tools are raised to Position 2 (noted above) and the operator propels the BRC to the next target tie, at which time the compaction sequence is repeated.
[0036] This sequence is unique in placing new, clean ballast into the tie bed under the tie and also compacting the crib ballast. Both of these items are vital in getting newly-installed ties to have equal bearing of the wheels loads with the older ties already in track. Faster operation can be achieved by adding additional compactor bars ( 8 ) and crib compactors ( 4 ), with a larger horsepower engine and hydraulic system as required to match the power needs. The benefits of placing the clean ballast under the ties and consolidating the crib ballast would result in less track settlement and longer surface life.
[0037] FIGS. 7-14 are schematic views of another example embodiment of a tie gang ballast replacer-compactor showing the system in operation in more detail (thus, depicting another embodiment of a method). As shown in FIG. 7 , the work head is raised for clearing travel at track speed. In FIG. 8 , the work head is raised to clear ties and track for movement between ties during the work cycle, which facilitates travel at low speed. In FIG. 9 , the work head is positioned for the start of the replace/compact cycle. In particular, the tie locks are engaged about a tie and the compaction cycle is ready to begin. In FIG. 10 , the compactor bar begins its stroke, moving into a crib and pushing clean stone with it. As shown in FIG. 11 , the compactor bar continues the stroke, moving in an arc downwardly and rearwardly pushing the clean stone with it. In FIG. 12 , the compactor bar continues the stroke, moving under the front edge of the clamped tie, pushing clean stone with it. In FIG. 13 , the compactor bar continues the stroke to maximum extension under the tie and the ballast is compacted. In FIG. 14 , after the compaction cycle is complete, the BRC's track engaging tools are then retracted to “Position 2/8”, ready to move to the next target crosstie to be tamped. It should be noted that, in some embodiments, variable frequency vibration is applied to the ballast through the pusher faces obtain the enhanced compaction of the ballast.
COMPONENT LIST OF AN EXAMPLE EMBODIMENT
[0000]
1 ) Mass Weight—attaches to numerous items
2 ) Hydraulic Cylinder to operate Compactor Bar
3 ) Steel welded frame attached to Mass 1 ) that supports Compactor Bars 8 ) & Crib Compactor 4 ) & 5 )
4 ) Crib Compactor (4) ea
5 ) Vibrator Motor for Crib Compactor 4 )
6 ) Lift Linkage for Crib Compactor 4 )
7 ) Lift Hydraulic Cylinder for Crib Compactor 4 )
8 ) Compactor Bar Assy
9 ) Vibratory Eccentric Drive mechanism (4) ea that pivotally support Compactor Bars 8 )
10 ) Ballast Pusher Faces (4) ea, replaceable
11 ) Parabolic path the Ballast Pusher Face 10 ) describes as it cycles down through the crib ballast, pushing & compacting it under the crosstie 12 )
12 ) Crosstie (wood, concrete, plastic, steel); part of railroad track
13 ) Railroad Rail, any weight & size, part of railroad track
14 ) Crib Ballast between ties, part of railroad track
15 ) Tie Lock Jaw, fixed, (2) ea
16 ) Tie Lock Jaw, moveable, (2) ea
17 ) Hyd. Cylinder to operate Tie Lock Jaw 16 ) (2) ea
18 ) Welded steel frame that mounts Tie Lock components 15 ), 16 ) & 17 ); (2) ea
19 ) Linkage Arms that movably support Tie Lock components 15 ), 16 ), 17 ) & 18 ); (4) ea
20 ) Hyd. Cylinder that raises/lowers Tie Lock Assy 29 ); (2) ea
21 ) Bracket on Chassis 22 ) where Tie Lock Assy 29 ) is pivotally mounted; (2) ea
22 ) Chassis, self-propelled, fabricated steel with (2) axles, (4) flanged wheel, an engine, hydraulic, pneumatic & electrical systems and an operators control station
23 ) Laterally Movable Brackets attached to Mass 1 ); (8) ea
24 ) Hyd. Cylinder to move Mass 1 ) & its attachments laterally; (2) ea
25 ) Horizontal Support Bars that support Mass 1 ) & permit lateral movement; (2) ea
26 ) Vertically Movable Support Frame that support Horiz. Support Bars 25 ) & Mass 1 ); (2) ea
27 ) Vertical Slide Posts that support Vertically Movable Support Frame 26 ) and all dependent attachments; (2) ea
28 ) Hyd. Cylinder to move the Vertically Movable Support Frame 27 ) and all dependent attachments; (2) ea
29 ) Tie Lock Assembly, complete, includes 15) through 20) items inclusive; (2) ea
30 ) Flanged Wheels, attached to Chassis 22 ), (4) ea or more depending on size/weight of Chassis
31 ) The general area of Crib Ballast 14 ) that can be reached & tamped by the Ballast Pusher Faces as they are moved laterally throughout the total range of lateral movement & cycled down & up
32 ) The total ballast section under the ties of the railroad track; often badly fouled
33 ) Phantom outline of Mass 1 ), Compactor Bars 8 ), Ballast Pusher Faces 10 ), and Crib Compactors 4 ) & 5 ) in the “innermost” position of lateral movement so as to cover the maximum length of tie bed ballast section
[0071] It should be emphasized that the above-described embodiments are merely examples of possible implementations. Many variations and modifications may be made to the above-described embodiments without departing from the principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
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Ballast replacer-compactors and related methods are provided. A representative ballast replacer-compactor includes: a frame; a crib compactor mounted to the frame and operative to compact crib ballast; and a compactor bar mounted to the frame and operative to urge crib ballast downwardly and beneath a tie. A representative method for servicing rail system ties includes: engaging crib ballast positioned adjacent to a target tie; and forcing the crib ballast downwardly and beneath the target tie.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/173,740, filed Apr. 29, 2009, which is incorporated by reference herein in its entirety.
BACKGROUND INFORMATION
1. Technical Field
The present disclosure relates to methods and valves for controlling the flow of fluid through a bore and more particularly, the disclosure relates in some embodiments to methods and ball valves for use in the oil and chemical process industry. More particularly, this disclosure relates to double piston, trunnion-mounted ball valves.
2. Background Art
Ball valves are commonly used in both the oil and chemical process industries. A type of ball valve used to control flow of a fluid is an apertured ball valve such as is disclosed in PCT Patent Application No. WO 93/03255 published on Feb. 18, 1993, incorporated by reference herein. In an apertured ball valve the valve operation or function may be broken down into two separate stages. Firstly, the ball moves between an open and a closed position by rotating through 90 degrees such that the ball aperture from an orientation coaxial with the flow direction, i.e. when the valve is open, to a position whereby the ball aperture is normal or perpendicular to the flow direction and the valve is closed. Secondly, the valve seals in the closed position to prevent flow through the bore across the ball valve. Therefore, the on-off control of flow through the valve is achieved by rotating the ball through 90° within the valve housing. Another ball valve is disclosed in U.S. Pat. No. 6,708,946, the teachings of which are incorporated herein by reference.
There are two basic types of ball valve mechanisms which currently exist. First, there is the trunnion mounted ball system in which the ball element is positionally constrained inside the valve, usually by radial bearings. The ball is rotated by the application of torque through a valve stem to the trunnion. Sealing occurs as a result of the valve seat on the upstream (or high pressure) side of the valve “floating” onto the ball element and causing engagement between a surface of the valve seat and the surface of the ball. The advantage of this system is that it provides highly reliable rotation between the valve open and the closed positions. The principal disadvantage of this system is that seal reliability is reduced because the sealing force only develops in proportion to the annular area of the valve seat. Further, in high pressure applications, the force exerted on the ball on the upstream side of the valve can result in deformation of the ball and leakage between the ball and another valve seat located on the downstream (or lower pressure) side of the valve. Thus, when trunnion mounted ball systems are used in high pressure wells and especially those in which the well fluid has a high proportion of particulate matter, being generally known as “aggressive” wells, the pressure is such that fluids and/or particulate matter may leak past seals between the ball and the valve seats. This often results in the valve not achieving integrity of sealing. In such cases, this type of ball valve is unable to operate properly in such conditions.
The second type of ball valve mechanism which effects the abovementioned function is known as the “floating ball system”. In this system the ball is not positionally constrained relative to the valve body. Rotation is caused by the application of force to a point which is offset from the ball centre which, in conjunction with the mating curvatures of the ball and seat, cause the ball to rotate. Sealing occurs as a result of the ball “floating” onto the valve seat. The advantage of this mechanism is that the reliability of the seal is increased, because the sealing force develops in proportion to the circular area of the ball to seat contact. The disadvantage of this type of mechanism is that the rotational reliability is reduced as the friction factor between the ball and seat are considerably larger than that of trunnion mounted devices. With high pressure and aggressive types of wells and particulate flows of the type described above, the reliability of this valve in those applications creates a problem in that the torque necessary to rotate the ball becomes excessively high, and thus, the valve can seize between the open and the closed position giving rise to serious problems in both operational and safety terms.
It would be desirable to provide a method and/or improved ball valve design which may obviate or mitigate at least one or more of the aspects associated with the aforementioned disadvantages.
SUMMARY OF THE DISCLOSURE
The above disadvantages may be addressed by embodiments of the method and ball valve structure as disclosed herein wherein higher pressures on the inlet side of the valve are used, while the valve moves toward and is maintained in the valve closed position, to create movement of a ball element of the valve so as to bias the ball element against both of the piston seat elements (or rings) used to create the seals in a double piston ball valve and thereby effectively create and enhance a double seal within the valve while in the valve closed position.
Thus, in one aspect, the disclosure is directed to a double piston, trunnion-mounted ball, valve structure comprising:
(a) a valve body defining an internal cavity and a longitudinal bore; (b) a rotatable, longitudinally moveable ball element positioned in the cavity and comprising a fluid flow passage therethrough when in a flow position; (c) first and second longitudinally moveable piston seats, the first seat located upstream of the ball element, the second seat located downstream of the ball element; and (d) a trunnion assembly fixedly engaging the ball element, one or more portions of the trunnion assembly disposed within one or more corresponding recesses of the valve body, each recess having a bias element exerting force on the trunnion assembly to oppose a load force acting on the ball element.
In certain embodiments the valve body comprises a bonnet, and the trunnion assembly comprises a lower trunnion, a portion (or portions) of which is/are slideably disposed within one or more recesses in the valve body, and an upper trunnion, a portion (or portions) of which is/are slideably disposed within one or more recesses in the bonnet, the respective recesses receiving or containing respective bias elements. Trunnions may be integral or non-integral with the ball element of the ball valve structures described herein. Ball valve structures in accordance with the present disclosure comprise a valve stem rigidly affixed to the upper trunnion and extending through an aperture in the bonnet. In certain embodiments, the piston seat located downstream of the ball element is slideable downstream in the valve body until reaching a fixed position where the downstream piston seat contacts the valve body and is then restricted in further downstream movement. In certain embodiments, the bias elements comprise components and materials allowing for controlled movement of the ball element within the cavity upon movement of the ball element due to application of the load force causing the ball element to sealingly engage with the downstream piston seat.
In certain embodiments, the bias elements are independently selected from the group consisting of wave springs, crescent springs, spring washers, belleville springs (also known as disc or cone washers), and combinations thereof, including stacks of two or more of these. Any of these may have contact flats, as further explained herein. It will be understood by those skilled in the art that the terms “washer” and “spring” are used interchangeably in this art. In fact, sometimes the terms “spring washers” and “washer springs” are employed for the same meaning for the same component and function. Coil springs may be used in certain embodiments. To avoid confusion, the term “bias element” is used when describing the entire component in a particular recess, whether a single spring or washer, or a plurality of springs or washers stacked in any manner. As used herein the term “bias element” means one or more components that function to exert an opposing, resisting force to an adjacent element exerting a force upon it. In the context of apparatus and methods of the present disclosure, one or more bias elements are employed to oppose a force that is applied to the upstream seal seat that contacts and sealably engages with the ball element from a higher pressure side of the valve when the ball valve is in a valve closed position. The bias elements may be present in recesses in the valve bonnet and/or valve body.
In certain embodiments the bias elements may be composite in nature, for example one or more belleville springs stacked together with one or more wave springs in one or more of the recesses. In these embodiments, the material, diameter (internal and outer), thickness, deflection, percent deflection, and other properties of the individual springs or washers may be the same or different. Disc springs, and others described herein, may be stacked together in certain bias element embodiments to enhance and/or adjust performance characteristics. In certain bias element embodiments the washers or springs may be stacked in parallel, which enhances load bearing characteristics. In certain other bias element embodiments, washers may be stacked in series, as described further herein. Combination stacking, in parallel and in series, may increase both load bearing and deflection. Belleville springs and other types of disc springs mentioned above may be used in varying thickness in the same bias element to achieve particular performance objectives.
In certain embodiments, the ball valve structure comprises:
(a) a housing comprising a valve body and a bonnet which define a cavity (void space) within the housing and also a bore having a longitudinal axis which runs through the bore, the bore allowing for passage of fluids from a higher pressure inlet to the ball valve structure, through the bore, and then from a lower pressure outlet of the ball valve structure when the ball valve structure is in a valve open position; (b) a ball element fitting within the cavity of the housing and slideably moveable in both directions along a path aligned and substantially parallel with the longitudinal axis, the ball element disposed within the cavity of the housing such that the ball element may also be rotated between a first position in which the ball element is oriented such that a hollow aperture within the ball body is aligned with the longitudinal axis of the bore, this first position defining the valve open position, and a second position in which the ball element is rotated through approximately 90° such that the ball body fully obstructs the bore, this position defining a valve closed position, the ball element comprising:
(i) a ball body having the hollow aperture therein, such that when the hollow aperture aligns with the longitudinal axis of the bore in the valve open position, the hollow aperture thereby permits a flow of fluids through the bore; (ii) a lower trunnion disposed at a lower end of the ball body and fixedly engaged with the ball body, the lower trunnion being disposed within a recess of the valve body such that the lower trunnion may slideably move therein, the recess of the valve body receiving a first bias element; (iii) the first bias element exerting an opposing force on the lower trunnion to oppose a load force which acts to push against the ball element from the higher pressure inlet side of the ball valve structure when in the valve closed position; (iv) an upper trunnion disposed at an upper end of the ball body and fixedly engaged with the ball body, the upper trunnion being disposed within a recess of the bonnet such that the upper trunnion may slideably move therein, the recess of the bonnet receiving a second bias element; (v) the second bias element exerting an opposing force on the upper trunnion to oppose a load force which acts to push against the ball element from the higher pressure inlet side of the ball valve structure when in the valve closed position, and (vi) a stem rigidly affixed to the upper trunnion and extending through an aperture in the bonnet so that the ball valve structure may be actuated between the valve open position and the valve closed position by rotation of the stem, the stem slideably moveable within the aperture in the bonnet to accommodate movement of the ball element due to the opposing forces and load forces acting on the lower and upper trunnions of the ball element when in the valve closed position;
(c) a first piston seat located at the higher pressure inlet to the ball valve structure and positioned within the valve body such that the first piston seat may slideably move along the longitudinal axis within the valve body, the fluid pressure at the higher pressure inlet being used to exert a load force against the first piston seat such that the first piston seat may sealingly engage with the ball body and exert the load force against the upper trunnion and the lower trunnion, thereby causing movement of the ball element along the longitudinal axis within the housing; and (d) a second piston seat located at the lower pressure outlet to the ball valve structure and positioned within the valve body such that the second piston seat may slideably move along the longitudinal axis within the valve body until reaching a fixed position where the second piston seat contacts the valve body and is restricted in movement along the longitudinal axis in one direction, and further wherein the movement of the ball element due to application of the load force in (c) causes the ball body to also sealingly engage with the second piston seat and the first and second bias elements allowing for controlled movement of the ball element within the cavity of the housing.
In another aspect, the disclosure is directed to a method for creating a seal in a double piston-type trunnion-mounted ball valve comprised of a ball element with an aperture therein defining a bore for fluid communication between an inlet and outlet to the ball valve when in a valve open position, the bore also defining a longitudinal axis that lies within the bore aligned in the direction of fluid flow when in a valve open position, a first piston seat located at the inlet to the ball valve having a higher fluid pressure when in a valve closed position, and a second piston seat located at the outlet to the ball valve having a lower fluid pressure when in the valve closed position. The method comprises:
(a) rotating the ball element to the valve closed position until the higher fluid pressure at the inlet to the ball valve creates a load force that is applied to the first piston seat so that the first piston seat sealingly engages with the ball element and creates a first seal, the load force also causing the ball element to move due to application of the load force and thereby sealingly engage with the second piston seat and create a second seal; and (b) applying one or more opposing forces to the ball element such that movement of the ball element in (a) is controlled.
These and other features of apparatus and methods of this disclosure will become more apparent upon review of the brief description of the drawings, detailed description, and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The manner in which the objectives of this disclosure and other desirable characteristics can be obtained is explained in the following description and drawings included herein in which:
FIG. 1 is a schematic cross-sectional view of a conventional (prior art) trunnion-mounted double piston ball valve;
FIG. 2 is a schematic cross-sectional view of a first embodiment of a trunnion-mounted double piston ball valve according to the present disclosure comprising one or more spring devices as bias elements employed to oppose a force that is applied to the upstream seal seat that contacts and sealably engages with the ball element from a higher pressure side of the valve when the ball valve is in a valve closed position;
FIG. 3 is a further schematic cross-sectional view of the ball valve embodiment illustrated in FIG. 2 ;
FIG. 4 is a schematic cross-sectional view of a second embodiment of a trunnion-mounted double piston ball valve according to the present disclosure comprising a different type of spring element as bias elements employed to oppose a force that is applied to the upstream seal seat that contacts and sealably engages with the ball element from a higher pressure side of the valve when the ball valve is in a valve closed position;
FIG. 5 is a further schematic cross-sectional view of the ball valve embodiment illustrated in FIG. 4 ;
FIGS. 6-15 illustrate schematically various non-limiting embodiments of bias elements useful in various ball valve embodiments in accordance with this disclosure; and
FIGS. 16 and 17 illustrate schematically two alternative embodiments for modified trunnions useful in apparatus of this disclosure.
It is to be noted, however, that the appended drawings are not to scale and illustrate only typical embodiments of this disclosure, and are therefore not to be considered limiting of its scope, for other equally effective embodiments may become apparent after reading this disclosure.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the disclosed methods and apparatus. However, it will be understood by those skilled in the art that the methods and apparatus may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
This disclosure relates in embodiments to double piston, trunnion-mounted ball valves. This valve type is used for double isolation in one valve, however, recently a failure mode has been identified in large, high pressure valves, which under the condition of high upstream pressure and low valve cavity (void space) pressure, there can be leakage between the cavity and downstream side of the valve. The cause of the leakage is due to differential movement between the ball and a downstream seat ring. The ball is deflected on the downstream side by upstream pressure, but it is believed that the downstream seat lacks sufficient pressure load in order to deform the seat and to maintain contact with the deformed ball. At high pressure the valve seals, as the seat ring is deformed by the pressure and it is able to follow the deformed shape of the ball.
The failure mode discussed above limits the functionality of the valve. Design optimization using a stiff ball, flexible seat rings and additional spring loading on the seat ring have heretofore either not been successful, or only successful by introducing additional complexity into the design and manufacture of the valves.
The valves and methods of using same herein disclosed have two primary features. The downstream seat is partially loaded by upstream pressure, and not solely cavity (void space) pressure, effectively putting the valve into the “both seals energized from upstream pressure” category. Second, the additional loading on the downstream seat using applied force derived from upstream pressure at least minimizes and may eliminate the effects associated with the failure mode discussed above.
Ball elements in ball valve embodiments of the present disclosure are supported on trunnion bearings, such that pressure load when sealing is transferred into the valve body. Hence the name trunnion mounted ball valve. The valve preferentially seals on the upstream side.
A different, prior art design of valve exists where the ball element is supported entirely by the seats—a seat supported design—and as discussed above this valve seals downstream and has no trunnions. The pressure load is taken by the seat to ball interface in this design. Seat supported designs can only be used at small sizes and low pressures. The ball to seat load becomes so great on the larger sizes/higher pressures that the stem cannot turn the valve. The normal limit of seat supported valves is about 8 inches (about 20 cm), class 300.
Ball valves and methods of using same of the present disclosure include one or more bias elements for applying an opposing force to the upper and lower trunnion supports. As defined earlier herein, bias elements may comprise one or more springs which may be used to apply an opposing force to counter the applied force derived from the higher pressure upstream of the valve. Such spring devices may be independently selected from the group consisting of wave washers, crescent washers, spring washers, Belleville washers (also known as disc or cone washers), and combinations thereof, including very stiff Belleville-type springs, and stacks of two or more of these. The springs are designed/adjusted so that with high pressure on the upstream side, the ball element is allowed to move toward the downstream seat, with the limit of movement controlled by the bias elements, until the seat ring contacts the valve body. At that point, the ball then starts to load the downstream seat, producing a downstream seat seal driven by upstream pressure. The bias elements desirably do not permit the entire upstream pressure load to be applied to the ball and downstream seat, so the valve remains operable (in other words, a human or electro-mechanical operators may turn the valve without undue effort). The upstream seat retains the original loading.
Referring now to the drawing figures, in which the same numerals are used in the various figures for the same elements unless otherwise noted, FIG. 1 illustrates schematically a cross-sectional view of a conventional (prior art) trunnion-mounted double piston ball valve 2 having a valve body 4 , a bonnet 6 , and ball element 8 . Valve body 4 defines a valve bore 10 . One or more bolts 12 , 14 and nuts 16 , 18 are used to fasten bonnet 6 to valve body 4 in conventional fashion. Valve 2 also comprises a valve stem 20 connected to an upper trunnion 22 , while a lower trunnion 24 is positioned within a lower portion of valve body 4 . Valve 2 further comprises a first, upstream piston 26 , and a second, downstream piston 28 , each having respective ball seals 30 , 32 . An upper connector ring 34 and a lower connector ring 36 connect respective piston seals to their pistons. Upper and lower elastomeric O-ring seals 38 , 40 are provided as illustrated.
At this point it is important to note the gaps 42 , 44 , 64 , and 66 . Gaps 42 and 44 are between valve body 4 and downstream edges of downstream piston 28 , while gaps 64 and 66 are between valve body 4 and upstream edges of upstream piston 26 .
Still referring to FIG. 1 , valve 2 comprises upper and lower dual O-rings 46 , 48 , which form seals between ball seal 32 and downstream piston 28 , and between ball seal 30 and upstream piston 28 , respectively as illustrated.
Ball element 8 comprises an aperture 70 defined by an internal surface 72 , and an external surface 74 . A limitation of prior art valve 2 is the possibility of leakage at points of contact 50 between ball element external surface 74 and downstream piston seal 32 , as the downstream pressure is frequently too low to provide a good seal.
FIG. 2 is a schematic cross section view of a trunnion-mounted, double piston ball valve embodiment 100 according to the present disclosure. Ball valve embodiment 100 comprises certain mechanical and function features not present in prior art ball valve 2 illustrated in FIG. 1 . First, note that ball valve 100 includes modified trunnions 22 , 24 . Upper trunnion 22 includes posts 80 , 82 that extend into respective recesses 54 , 52 in bonnet 6 , as well as spring bias elements 60 , 61 disposed in recesses 54 , 52 , respectively. A similar arrangement is present on the lower trunnion 24 , which is modified to include posts 84 , 86 that extend into respective recesses 58 , 56 in valve body 4 , as well as spring bias elements 62 , 63 disposed in recesses 58 , 56 , respectively. In embodiment 100 of FIG. 2 posts 80 , 82 , 84 , and 86 are illustrated as integral with their respective trunnions; however, posts 80 , 82 , 84 , and/or 86 could just as well be separate posts screwed or otherwise mounted into trunnions 22 , 24 , as illustrated in FIGS. 16A and 16B . Another alternative would be to have two separate upper and lower rings or bushings, 87 , 88 , as illustrated in FIGS. 17A and 17B , upper ring 87 having extensions 80 , 82 extending therefrom 180 degrees apart, and extension 84 , 86 extending from lower ring or bushing 88 and positioned 180 degrees apart. The rings may be loosely placed in position during construction of the valve, or may be welded or brazed to the trunnions. The posts or extensions 80 , 82 , 84 , and 86 may generically be referred to as “portions.” None of the portions 80 , 82 , 84 , 86 , recesses 52 , 54 , 56 , 58 , or bias elements 60 , 61 , 62 , and 63 are present in prior art ball valves, nor are the two alternative arrangements mentioned above known in the prior art. In embodiment 100 , bias elements 60 , 61 , 62 , and 63 may be as illustrated in FIG. 8A (parallel stack). Functionally, bias element 60 , 62 apply an opposing force to the trunnions to oppose a force that is applied to upstream piston seal seat 30 that contacts and sealably engages with ball element 8 from a higher pressure upstream side of the valve when the ball valve is in a valve closed position.
FIG. 3 is a further cross sectional view of ball valve embodiment 100 illustrated in FIG. 2 under upstream pressure. As can be seen in FIG. 3 , under application of upstream pressure, ball element 8 will be pushed over to downstream, piston seat 32 . The contact force between downstream piston seat 32 and ball element 8 will be controlled by bias springs 60 , 61 , 62 , and 63 . Notice that gaps 42 , 44 , have been reduce to zero, while gaps 64 , 66 have increased, bias elements 60 , 62 have contracted, while bias elements 61 , 63 have expanded in the downstream direction, providing controlled downstream movement of ball element 8 and pistons 26 , 28 , and improving sealing at 50 .
FIGS. 4 and 5 are schematic cross-sectional views of a second ball valve embodiment 200 in accordance with the present disclosure. Embodiment 200 of FIGS. 4 and 5 is similar to embodiment 100 illustrated schematically in FIGS. 2 and 3 except that bias elements 90 , 91 , 92 , and 93 are employed having a series configuration as illustrated in FIG. 8B .
FIGS. 6-15 illustrate various non-limiting embodiments of bias elements useful in various ball valve embodiments in accordance with this disclosure. It will be understood that any of the various embodiments illustrated in FIGS. 6-15 may be used, alone or in conjunction with other types illustrated herein, in ball valve embodiments 100 and 200 . FIG. 6 illustrates a prior art conical spring 260 , having a spring body 252 , an inner hole 253 having an inner diameter ID, and an outer periphery 255 having diameter OD, as well as overall height H, cone height h, and thickness t. Embodiment 260 of FIG. 7 is similar to embodiment 250 of FIG. 6 , except embodiment 260 includes an upper contact flat 257 and a lower contact flat 259 . Certain local standards may require that a contact flat 257 should be applied to the top inside diameter and a second contact flat 259 to the bottom outside diameter of the disc spring. For example, for disc springs with a material thickness greater than 6 mm, DIN 2093 specifies this. Contact flats 257 , 259 may aid alignment of the disc springs during stacking, but may cause a reduction in the lever arm length and therefore an increase in the spring force. This is compensated by reducing the material thickness, which doesn't alter the overall height or spring force at 75% from the original disc but does increase the cone angle.
FIG. 8A illustrates a cross-sectional view of a parallel stack 270 of six identical Belleville springs, 272 , 274 , 276 , 278 , 280 , and 282 . FIG. 8B illustrates a cross-sectional view of a series stack 300 of five Belleville springs 290 , 292 , 294 , 296 , and 298 . As noted by the web site of Belleville Springs Ltd., Arthur Street Lakeside, Redditch, B98 8JY, United Kingdom, single disc springs may be assembled ‘opposed to each other’ to form a spring column. This ‘in series’ formation (such as illustrated in FIG. 8B ) is a means of multiplying the deflection of a single disc spring, while the force element remains as that for a single spring. For example, a disc spring that requires a force of 5000N to deflect 1 mm, when assembled to form a column of 10 disc springs in series, will require a force of 5000N to deflect 10 mm. The cumulative effect of bearing point friction of large numbers of disc springs stacked in series can result in the disc springs at each end of the stack deflecting more than those in the center. In extreme cases this may result in over-compression and premature failure of the end springs. A ‘rule of thumb’ according to Belleville Springs Ltd. is that the length of the stacked disc springs should not exceed a length approximately equal to 3 times the outside diameter of the disc spring. Normally, disc springs stacked in ‘series’ formation are of identical dimensions, however, it is feasible to stack numbers of disc springs of increasing thickness in order to achieve ‘stepped’ and progressive characteristics. With such arrangements, it may be necessary to provide some form of compression limiting device for the ‘lighter’ disc springs, to avoid over-compression whilst the ‘heavier’ springs are still in process of deflection.
Disc springs are assembled ‘nested’ inside each other, i.e. the same way up, the resultant force for such a column is the force element of a single disc spring multiplied by the number of ‘nested’ disc springs in the column, while the deflection remains the same as for that applicable to a single disc spring. This is the situation in embodiment 270 of FIG. 8A . As again explained by Belleville Springs Ltd., it should be realized that the individual disc springs in a column assembled in parallel perform as separate entities, thus generating considerable interface friction. For a given deflection, this interface friction will result in 3% increased force per interface, this must be taken into account when calculating the total force from parallel stacking. For example, a disc spring that requires a force of 5000N to deflect 1 mm, when assembled of 3 disc springs in parallel, will require a force of 15900N to deflect 1 mm. While any number of disc springs may be used in valve embodiments of the present disclosure, it may be advisable that the number of disc springs in parallel not normally exceed 3, or in extreme cases 5 springs, to minimize heat generated by friction or, in the case of static applications, to ensure a workable relationship between the loading and unloading characteristics. The hysteresis resulting from parallel stacking can be employed to advantage in those applications of a ‘shock absorbing’ nature, requiring a damping feature.
The life of disc springs in parallel arrangements may depend on adequate lubrication of the spring interfaces. Combinations of both series and parallel stacking, as in embodiment 350 of FIG. 9A , is a means of multiplying both force and deflection. Embodiment 350 includes a first parallel stack of disc springs 352 , 354 pointing ‘upward’ stacked on top of a second parallel stack of disc springs 356 , 358 pointing ‘downward’, in turn stacked upon a second upward pointing stack of disc springs composed of disc springs 360 , 362 . The guidelines applicable to this type of arrangement are basically those already outlined, but it may be advisable to minimize the number of springs in the stack by way of examining the various alternatives. An example given by Belleville Springs Ltd., may illustrate the point. For example, a disc spring that requires a force of 5000N to deflect 1 mm, when assembled to form a column consisting of 3 disc springs in parallel, and 10 units of 3 parallel discs in series—(total 30 discs), will result in a force requirement of 15900N to deflect the stack 10 mm—(incorporating an allowance of +6% for friction).
FIGS. 9B and 9C illustrate schematically the relationship of load to deflection for two different stacks of Belleville disc springs. It may be seen that the load for a given deflection, or conversely, the deflection for a given load, may be adjusted by the number and arrangement of identical disc springs. If the materials of the disc springs may be another variable, then it may be seen that the valve designer has many opportunities to achieve a successful ball valve design without undue experimentation.
FIGS. 10-15 provide schematic illustrations of further prior art disc spring embodiments that may be employed in the ball valves and methods of the present disclosure. FIG. 10A is a schematic plan view, and FIG. 10B a cross-sectional view, of a prior art single wave disc spring (flat rim) 370 , having an outer periphery 371 having a diameter A, and an inner through hole 372 having a diameter B, a height C, and material thickness D. The flat rim may enhance load bearing capability and distribute load forces.
FIG. 11A is a schematic plan view, and FIG. 11B a cross-sectional view, of a prior art three wave disc spring 450 , having an outer periphery 451 having a diameter A, and an inner through hole 452 having a diameter B, a height C, and material thickness D. Three wave disc springs may provide greater load bearing capacity than a single wave washer but may have a smaller deflection range.
FIG. 12A is a schematic plan view, and FIG. 12B a cross-sectional view, of a prior art single wave (crescent) disc spring 470 , having an outer periphery 471 having a diameter A, and an inner through hole 472 having a diameter B, a height C, and material thickness D. This shape disc spring delivers the most consistent spring rate over the widest deflection range.
FIG. 13A is a schematic plan view, and FIG. 13B a cross-sectional view, of a prior art ‘style 10’ disc spring 500 , having an outer periphery 501 having a diameter A, and an inner through hole 502 having a diameter B, a height C, and material thickness D. Embodiment 500 is essentially a modified conical disc spring. The disc spring of embodiment 500 enhances spring deflection range while load bearing capacity is moderately reduced from embodiment 250 of FIG. 6 .
FIG. 14A is a schematic plan view, and FIG. 14B a cross-sectional view, of a prior art ‘style 12’ disc spring 520 , having an outer periphery 521 having a diameter A, an inner through hole 522 having a diameter B, a height C, and material thickness D. Embodiment 520 also includes a plurality of fingers 523 (6 in embodiment 520 , although the number could be more or less). Embodiment 520 is a conical spring embodiment having a scalloped periphery that further enhances spring resiliency at the expense of load bearing capacity from embodiment 250 of FIG. 6 .
FIG. 15A is a schematic plan view, and FIG. 15B a cross-sectional view, of a prior art ‘style 14’ disc spring 600 , having an outer periphery 601 having a diameter A, and an inner through hole 602 having a diameter B, a height C, and material thickness D. Embodiment 600 is essentially another modified conical disc spring having enhanced spring deflection range while load bearing capacity is reduced from embodiment 250 of FIG. 6 .
Disc springs may be comprised of a variety of materials and sizes. Variable include OD, ID, thickness, cone height, total height, ratio of cone height to thickness, weight per 1000 pieces, percent deflection and deflection (length) under force and compression stress. These parameters depend in large part on the valve into which the bias elements are to be used, and the service to which the valve is to be used. Aside from the strictly the valve requirements, Belleville disc springs are available commercially in OD ranging from about 4 mm up to about 250 mm. The thickness is generally categorized as under 1.25 mm (DIN 2093, Group 1, without contact flats); 10.25 mm up to and including 6 mm (DIN 2093 Group 2, without contact flats); and over 6 mm (DIN 2093, Group 3, with contact flats). They may, for example, be manufactured from high quality spring steel strip and forgings, having a standard phosphate and oiled protective surface treatment. Other surface treatments may be dictated by the particular valve service. For example, if corrosion resistance is called for, an inorganic coating comprising aluminum and zinc may be baked onto the disc spring to achieve an electrically conductive and highly corrosion resistant surface finish, or an adhesive organic compound may be applied and then baked onto the disc springs.
To meet certain standards, such as the DIN standards referenced herein, the disc springs may be pre-stressed and the machining and radiusing of the inside and outside diameters performed to remove stress raisers which could otherwise reduce disc spring life. Percent deflection may be about 15 percent, about 30 percent, about 45 percent, about 60 percent, about 75 percent or about 90 percent, with a total deflection ranging from about 0.02 mm up to about 2 mm, at forces ranging from about 20 to about 7600N and compressive stress ranging from about 100 to about 1500 N/mm 2 .
In certain embodiments the bias elements may comprise coil springs. Coil springs may afford greater deflection and percent deflection than disc springs, and therefore may be advantageous in certain embodiments. If used they may comprise metal, such as high quality steel, such as one or more stainless steels. They may comprise coatings as mentioned herein for disc springs, especially if ball valves described herein in accordance with the present disclosure will be used in corrosive environments.
From the foregoing detailed description of specific embodiments, it should be apparent that patentable methods and apparatus have been described. Although specific embodiments of the disclosure have been described herein in some detail, this has been done solely for the purposes of describing various features and aspects of the methods and apparatus, and is not intended to be limiting with respect to the scope of the methods and apparatus. 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 described embodiments without departing from the scope of the appended claims.
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Disclosed are a method and a ball valve structure which provide for an improved seal in a trunnion mounted, double piston ball valve, which is especially useful in applications requiring a seal against high pressures, such as in the oil, gas and chemical process industries. Higher pressures on an inlet side of the valve are used, while the valve moves toward and is maintained in a valve closed position, to create movement of a ball element of the valve so as to bias the ball element against both piston seat elements (or rings) used to create the seals. This movement of the ball element thereby effectively uses such upstream pressure to create and enhance a seal between the ball element and both piston seat elements while in the valve closed position.
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BACKGROUND OF THE INVENTION
This invention relates to semiconductor memory devices, and more particularly to an organization for a high density dynamic metal-oxide-semiconductor (MOS) random access memory (RAM) having an array of one transistor, one capacitor memory cells.
MOS dynamic RAMs are known in the art. These memories are fabricated on a single silicon chip using known MOS technologies. Typically n-channel MOS technology is used because of its inherent performance advantages. In recent years there has been a rapid evolution of MOS dynamic RAMs toward increased density and higher performance. Each new generation of RAMs has provided a four-fold increase in storage capacity over those of the previous generation. This evolution has been made possible by advances in n-channel MOS technology and in wafer patterning techniques leading toward a shrinkage in the size of the memory cell. Today MOS RAMs having a storage capacity of 16,384 bits (i.e., 16K RAMs) are commercially available. Presently, manufacturers are starting to introduce a 65,536 bit, or 64K, RAM; see Electronics, Sept. 28, 1978, pp. 109-116.
An example of 64K RAM is described in copending application Ser. No. 10,839, filed concurrently and having a common assignee with the instant application. In the Cenker et al RAM, the memory cell array is divided into two sub-arrays each having 128 rows and 256 columns. A two sub-array organization provides the advantage of having a refresh sequence (128 cycles) which is compatible with that of older generation RAMs by allowing simultaneous refresh of a row in each sub-array. A two sub-array organization also provides improved signals for sensing by virtue of having shorter bit-lines (column conductors) and, therefore, of reduced bit-line capacitance. In addition, the Cenker et al application discloses an arrangement for reducing power dissipation when the RAM is in a read or a write mode whereby only one of the two sub-arrays is fully selected for accessing a cell, i.e., both a row and a column are selected, while the other sub-array is partially selected for performing the refresh function only, i.e., only a row is selected. Therefore, the column decoders in the partially selected sub-array remains inactive to reduce both average and peak currents.
In dynamic memories having a large number of cells such as a 64K RAM, large transient current peaks on various conductors on the chip are a major problem. One such current peak occurs when the column conductors of the array are recovered to a precharge potential (normally VDD) after a memory function is completed. The charging of the combined capacitances of all the column conductors causes a transient surge of current on the VDD power supply lines. Insofar as increasing the number of cells in a memory also increases the total capacitance of the column conductors, the magnitude of the column precharge recovery current peak also increases with the number of cells. Another large current peak occurs when all the sense amplifiers in a sub-array are latched (i.e., activated). The discharge of the capacitances coupled to the "low-going" sense amplifier nodes causes a transient surge of current primarily on the VSS power supply lines. As the number of cells in a memory is increased, the number of sense amplifiers required is increased (as many as 512 in a 64K RAM); and, therefore, the magnitude of the latching current peak also becomes greater. Large current peaks on various conductors in the memory chip interfere with proper memory operation by causing capacitive and inductive pickup of unwanted signals on other conductors and by causing voltage drops on the power supply nodes of various circuits in the memory.
In addition to interfering with proper memory operation, large current peaks also have a deleterious effect on the reliability of the memory chip. It is well known that a metallic conductor in an integrated circuit may fail through a mechanism called electromigration. The rate of such failures is proportional to the peak current densities carried by the conductor. Therefore, from the standpoint of both proper memory operation and chip reliability it is important to minimize the peak currents in a high density dynamic RAM.
In the case of a RAM having two sub-arrays of memory cells such as the above-described 64K RAM of Cenker et al the problem becomes one of reducing peak currents in the memory while keeping both sub-arrays active for at least the cell refresh function. Prior art memory organizations using two sub-arrays have shortcomings in this regard. For example, in the 16K RAM described in IEEE Journal of Solid State Circuits, October 1976, pp. 570-573, By Ahlquist et al. a two sub-array RAM is operated with one of the two sub-arrays totally inactive at a given time. Thus both average and peak currents are reduced. However, such an arrangement would not permit simultaneous refreshing of a row in each sub-array or for reading and/or writing functions to take place in one sub-array while the refresh function takes place in the other sub-array.
SUMMARY OF THE INVENTION
The present invention is an improvement of the RAM organization described in the above-cited Ahlquist et al. paper in which an array of memory cells is divided into sub-arrays, and in which during a given operating cycle a cell is selected in only one sub-array. The improvements include the provision of appropriate means responsive to a part of the address for selecting a sub-array, control means for releasing the column conductors of each sub-array from the precharge potential shortly before row selection therein, means for activating in sequence the sense/refresh amplifier means in each sub-array after row selection therein beginning in the selected sub-array, the period between successive activations being sufficient for the latching current peaks caused by a prior activation to subside, the control means for recovering in sequence the column conductors in each sub-array to the precharge potential after completion of memory functions therein beginning in the non-selected sub-arrays, the period between successive recoveries being sufficient for the precharge current peak caused by a prior recovery to subside.
These improvements provide a RAM organization in which latching of the sense amplifiers in the two sub-arrays is staggered. The fully selected sub-array in which a cell is to be accessed is latched first. The partially selected sub-array is latched after a delay sufficient to allow the current peaks caused by latching in the fully selected sub-array to subside. In addition, the recovery of column conductors to a precharge potential is also staggered. The partially selected sub-array in which only the refresh function takes place is recovered first. The fully selected sub-array is then recovered after a delay sufficient to allow the current peak caused by the recovery of the partially selected sub-array to subside. Thus the peak current of the improved RAM is reduced as the current peaks from sense amplifier latching in each sub-array as well as those from column conductor recovery in each sub-array are made noncoincident.
Accordingly, it is an object of the present invention to provide an organization for a high density dynamic RAM with reduced peak current.
It is another object of the present invention to provide an organization for a high density dynamic RAM which reduces noise generation in the memory.
It is still another object of the present invention to provide an organization for a high density dynamic RAM which improves memory reliability.
The above and other objects of the invention are achieved in an illustrative embodiment described hereinafter. The novel features of the invention, both as to structure and method of operation, together with the other objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is solely for the purpose of illustration and description and is not intended to define limits of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a functional block diagram of a portion of a dynamic RAM according to the instant invention.
FIG. 2 is a schematic diagram of a row clock generator circuit.
FIG. 3 is a schematic diagram of a sense amplifier latching circuit.
FIG. 4 is a schematic diagram of a column decoder and sense amplifier circuits.
FIG. 5 is a schematic diagram of a row termination clock generator circuit.
FIG. 6 is a schematic diagram of a row decoder interrupt clock generator circuit.
FIG. 7 is a schematic diagram of a column precharge clock generator circuit.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a block diagram representative of a dynamic RAM in accordance with the instant invention. In its preferred embodiment the RAM is fabricated on a single silicon chip using n-channel MOS technology. The chip has 16 terminals or external connections; these include 8 multiplexed address input terminals A0 through A7, external voltage terminals VDD, VSS, and VBB, a data output terminal Q, a data input terminal D, a row enable clock input terminal RE, a column enable clock input terminal CE, and a write enable input terminal WE. The VDD, VSS, VBB, Q and D terminals are not shown in FIG. 1. In normal operation the external voltages applied to the chip are: VDD=5 V, VSS=0 V, and VBB=-5 V.
The chip includes a memory cell array which is divided into two sub-arrays, an upper 1001, and a lower 1002. Each sub-array is bisected by a group of 256 sense amplifiers and 64 column decoders into two blocks each having 64 rows and 256 columns of cells to provide a total of 32,768 (32K) cells for each sub-array. The entire array has 65,536 (63K) cells. A row of 256 reference cells is also included in each block. The bisection of each sub-array being across the column conductors, two half-column conductors are created from each column conductor in the sub-array.
An operation cycle for the memory begins when a row enable signal going from a TTL "high" logic level to a TTL "low" logic level is applied to the RE input to initiate the row clocks included in the timing generators 1009 which in turn strobe the 7 row address buffers 1010 and the CA8 column address buffer 1011. An 8-bit TTL level address previously applied to inputs A0 through A7 is converted to MOS level row address signals RA0 through RA6 and column address signal CA8. The MOS address signals are all double railed, that is, both the address bits and their complements are used for row selection. Therefore, each address signal includes both the address bit and its complement. The row address signals are used by the row decoders to select one row out of 128 in each sub-array. The row decoders which also select one of two reference rows in each sub-array are partitioned into four sections 1012 through 1015, one associated with each block. Each section consists of 16 individual row decoders each serving four rows. Selection of a row in one block of a sub-array also results in the selection of the corresponding or reference row in the other block of the sub-array. The CA8 address signal is used for various steering and enabling functions to determine which sub-array is to be fully selected. A fully selected sub-array is one in which both a row and a column are selected, whereas a partially selected sub-array is one in which only a row is selected. The CA8 signal is used to gate column address signals to only the column decoders associated with the fully selected sub-array via column address gates not shown in FIG. 1.
Before row selection takes place the sub-arrays are in their standby state, and the half-column conductors in the upper and the lower sub-array are maintained at VDD by column precharge clocks PCBU and PCBL, respectively. Shortly before row selection, the half-column conductors are released from their precharge potential, the release being initiated by the row address signal RA0.
The selected rows are activated by "high" logic level signals originating from row clocks CRU and CRL and applied to the row conductors (word lines) via row drivers associated with the selected rows. A "high" logic level in the memory is a voltage which is approximately equal to or greater than VDD-VT, where VT is the threshold of voltages of the transistors. A "low" logic level in the memory is a voltage which is approximately equal to VSS. A row driver is associated with each row conductor. The row clock generators CRU and CRL are initiated by a row address valid clock signal CRAV. The row address valid clock generator which is activated by row address signal RAO provides a signal which is delayed from the RAO signal by an interval representative of the time required for the row decoders to respond to the row address signals and to complete row decoding.
Once the selected rows are activated, data is transferred from the memory cells and the reference cells therein to the sense amplifiers via their associated half-column conductors. The details of the interconnection between the sense amplifiers and the half-column conductors are shown in FIG. 4. The small differential voltage signal present between each pair of half-column conductors is amplified to full logic levels upon latching of the sense amplifiers. The presence of full logic level signals on the half-column conductors after the sense amplifiers are latched serves to restore full voltage levels to the memory cells of the selected rows. In this manner all the memory cells along the selected rows are automatically refreshed.
The sense amplifiers of each sub-array are latched via the sense amplifier latching circuits SALU and SALL associated with the upper and the lower sub-arrays, respectively. The sense amplifier latching circuits couple the common source node of the cross-coupled transistors (4006 and 4004 in FIG. 4) of each sense amplifier to VSS.
However, it is well known in the art that amplification of small signals in bistable differential sense amplifiers should occur at a slow rate initially to insure that the small signals are properly amplified. Once the differential voltage across the sense amplifier nodes has been amplified to VT or greater the amplification rate can be increased. Therefore, more reliable rapid amplification can be achieved by latching the sense amplifiers in two stages. In the first stage the small differential signal on the sense amplifier nodes is permitted to move slowly towards its fully amplified level. Once this differential signal has reached approximately VT a second stage of latching is initiated to complete the amplification at a more rapid rate. The first stage of latching for sense amplifiers of both sub-arrays is initiated by a first sense amplifier strobe signal CSA1. In the fully selected sub-array the second stage of latching is initiated by a second sense amplifier strobe signal CSA2 delayed from CSA1 by a time interval sufficient to allow the differential signal to reach approximately VT. In the partially selected sub-array the second stage of latching is initiated by a third sense amplifier strobe signal CSA3 delayed from CSA2 by a time interval sufficient to allow the latching current peak which occurs during the second stage of latching in the fully selected sub-array to subside. To insure that the latching current peaks do not coincide, the delay between CSA2 and CSA3 advantageously should at least be the time required for a latching current peak to fall to half of its maximum value. In the preferred embodiment, this delay is typically 20 nanoseconds.
Using as inputs the signals provided by the sense amplifier strobe clock generators CSA1 through CSA3 and under the control of column address signal CA8, the sense amplifier latching circuits SALU and SALL initiate the second stage of latching of the upper and lower sub-arrays in the proper sequence according to which sub-array is fully selected.
The third sense amplifier strobe signal CSA3 used to initiate the second stage of latching in the sense amplifiers of the partially selected sub-array is also applied to row termination clock generator CRTD. The row termination clock generator provides a signal which is delayed from CSA3 by a time interval representative of the period required for the cells in the partially selected sub-array to complete their refresh operation. The row termination clock signal CRTD is then steered to the row clock generator (CRU or CRL) associated with the partially selected sub-array. Steering is accomplished by the row termination clock gates CRTU and CRTL under the control of column address signal CA8. Therefore, the row termination clock signal is not applied to the row clock generator associated with the fully selected sub-array. The row clock termination signal causes the row clock signal applied to the row conductors of selected rows in the partially selected sub-array to recover to VSS. Thus the selected rows of the partially selected sub-array are deactivated immediately after the refresh function is completed in that sub-array.
The row termination clock signal is also applied to the row decoder interrupt clock generator (CRDIBU or CRDIBL) associated with the partially selected sub-array. In response to the row termination clock signal the row decoder interrupt clock generator produces a row decoder interrupt clock signal which is delayed from the row termination clock signal by an interval representative of the time required to deactivate the selected rows in the partially selected sub-array. The row termination clock signal is not applied to the row decoder interrupt clock generator associated with the fully selected sub-array.
The above mentioned row decoder interrupt clock signal for the partially selected sub-array is applied to the column precharge clock generator (PCBU or PCBL) associated with the partially selected sub-array to initiate recovery of all half-column conductors therein to VDD. The column precharge clock signal is also applied to the sense amplifier latching circuit (SALU or SALL) associated with the partially selected sub-array to recover the output of that circuit to VDD and thereby disable the sense amplifiers of that sub-array.
In the fully selected sub-array, once CSA2 has initiated the second stage of latching of the sense amplifiers, column selection can occur and reading and writing memory functions can take place. Details of the reading and writing memory functions are described in the above-identified Cenker et al. application.
After memory functions in the fully selected sub-array are complete, recovery of the row enable signal on the RE input terminal to the TTL "high" logic level can occur to terminate the operating cycle. Recovery of the row enable signal causes the master row precharge clock signal PRO to go to a "high" logic level. The PRO signal in turn causes termination of the row clock signal (CRU or CRL) associated with the fully selected sub-array. Thus the selected rows of that sub-array are deactivated at the end of the operating cycle. The PRO signal is also applied to the row decoder interrupt clock generator associated with the fully selected sub-array and initiates a delayed signal CRDIBU or CRDIBL therefrom. The delay introduced by CRDIBU or CRDIBL is representative of the time required for the selected rows in the fully selected sub-array to deactivate. The row decoder interrupt clock signal is applied to the column precharge clock generator (PCBU or PCBL) associated with the fully selected sub-array to initiate recovery of the half-column conductors therein. The same column precharge clock signal also initiates the recovery of the sense amplifier latching circuit associated with the fully selected sub-array and thereby disables the sense amplifiers of the fully selected sub-array. Therefore, in the partially selected sub-array the row conductors and the half-column conductors are recovered and the sense amplifiers disabled immediately after the cell refresh function is completed. Whereas, in the fully selected sub-array the row conductors and the half-column conductors are recovered and the sense amplifiers disabled upon termination of the externally applied row enable signal. Thus the large current peak associated with the recovery of each sub-array is staggered and the peak current associated with recovery in the memory is reduced. To insure that the precharge current peaks do not coincide, the delay between recoveries in the two sub-arrays should advantageously be at least the time required for a recovery peak current to fall to half its maximum value. In the preferred embodiment this delay is typically 50 nanoseconds.
In operating cycles where only the refresh function takes place, both the upper and the lower sub-arrays are partially selected. In this mode, only the RE input terminal is activated and no column selection is initiated. This operation causes row selection and staggered sense amplifier latching to occur as described above. Recovery of the two sub-arrays is also staggered in the manner described above. However, the sequence for latching and for recovery as controlled by the column address signal CA8 is unimportant in the refresh mode since both sub-arrays are only partially selected.
Referring now to FIG. 2 there is shown a schematic diagram of the row clock generator circuit 2000. In the preferred embodiment two such circuits are used, one associated with each sub-array. The inputs and the output of the circuit associated with the lower sub-array are enclosed in parentheses. When both sub-arrays are in their standby state, the output of each circuit CRU or CRL is maintained at VSS owing to the master row precharge clock signal PRO being at the "high" logic level. At the beginning of an operating cycle, PRO goes "low" to enable the outputs to be switched "high" by the row address valid clock signal CRAV. The row address valid clock signal goes "high" when row decoding is complete causing the rise of the output of each circuit CRU and CRL to the "high" logic level. The output of each circuit remains "high" until either a corresponding row termination clock signal CRTU or CRTL or the master row precharge clock signal PRO goes "high". In the case of the circuit associated with the partially selected sub-array the row termination clock signal goes "high" before PRO. However, for the circuit associated with the fully selected sub-array the row termination clock signal has been blocked by the row termination clock gates, and its output remains output remains "high" until PRO returns "high" at the end of the operating cycle. Illustrative waveforms showing the typical behavior of the signals on the inputs and the output of the row clock generator circuits associated with the fully selected and the partially selected sub-arrays are included in FIG. 2. The waveforms are illustrative of the case where the upper sub-array is fully selected.
A schematic diagram of the sense amplifier latching circuit is shown in FIG. 3. Two such circuits are included in the preferred embodiment, one associated with each sub-array. The inputs and the output of the circuit associated with the lower sub-array are enclosed in parentheses. When both sub-arrays are in their standby state, the output of each circuit SALU or SALL is maintained at VDD by the corresponding column precharge clock signal PCBU or PCBL. The output of each circuit is coupled to the common source nodes of the sense amplifiers (4030 in FIG. 4) of the associated sub-array. At the beginning of an operating cycle the corresponding column precharge clock signal goes "low" releasing the output of each circuit. When the row clock signal CRU or CRL goes "high", transistor 3001 goes to its conducting state providing a very high impedance current path to VSS for the common source node of the sense amplifiers of the corresponding sub-array. The voltage at the common source node is forced to VDD-VT to bring the cross-coupled transistors of the sense amplifiers to the onset of conduction. When the first sense amplifier strobe signal CSA1 goes to a "high" logic level, transistor 3002 goes to its conducting state providing a relatively high impedance current path to VSS for the output and causing the common source nodes of the sense amplifiers in each sub-array to fall towards VSS at a slow rate characteristic of the first stage of latching.
In the circuit associated with the fully selected sub-array, the state of column address bit CA8 is such that transistor 3003 is in its conducting state and transistor 3004 is in its nonconducting state when the second sense amplifier strobe signal CSA2 goes "high". Thus CSA2 causes transistor 3005 to go to its conducting state providing a relatively low impedance current path to VSS for the output and causing the output to fall to VSS at a rapid rate characteristic of the second stage of latching. When the third sense amplifier strobe signal CSA3 subsequently goes "high", its effect is blocked owing to transistor 3004 being in its nonconducting state. In the preferred embodiment transistors 3001, 2003, and 3005 have transconductances in the ratio of 5:200:1500, respectively.
In the circuit associated with the partially selected sub-array the state of column address bit CA8 is such that transistor 3003 is in its nonconducting state and transistor 3004 is in its conducting state when CSA2 goes "high". Thus, the effect of CSA2 is blocked by transistor 3003. However, when CSA3 subsequently goes "high", it causes transistor 3005 to go to its conducting state, and the sense amplifiers of the partially selected sub-array to go into the second stage of latching. Once the output of either SALU or SALL has reached VSS, it remains at that potential until the corresponding column precharge clock signal PCBU or PCBL returns to a "high" logic level, at which time the output goes to VDD. As discussed above, in connection with the recovery of the half-column conductors, the column precharge clock signal which controls the column precharge in the partially selected sub-array goes "high" before the corresponding signal of the fully selected sub-array. Corresponding row termination clock signals CRTU and CRTL are used by the sense amplifier latching circuits to eliminate dc current paths. Illustrative waveforms showing typical behavior of the signals at the inputs and the output of the sense amplifier latching circuit have been included in FIG. 3 for the case in which the upper sub-array is fully selected.
Referring now to FIG. 4, there is shown a schematic diagram of four sense amplifiers 4002 through 4005 and their associated column decoder 4001. In the preferred embodiment each column decoder is associated with four half-column conductor pairs and four sense amplifiers. A selected column decoder remains ready to transfer information on four half-column conductor pairs 4008 through 4015 to four input/output (DQ) line pairs 4016 through 4023. For simplicity FIG. 4 shows only two of the four half-column conductors pairs, two of the four sense amplifiers and two of the four DQ line pairs. A typical sense amplifier 4002 includes a pair of cross-coupled transistors 4006 and 4007 which are latched by pulling the common source node 4030 to VSS via the sense amplifier latching circuits SALU or SALL. The sense amplifier is coupled to a pair of half-column conductors 4008 and 4009 through a pair of interrupt transistors 4024 and 4025. Upon application of the corresponding data transfer clock signal CCQU or CCQL, the signals on the sense amplifier nodes 4031 and 4032 are coupled directly to the DQ line pairs 4016 and 4017 through transistors 4026 and 4027. Transistors 4028 and 4029 are used to precharge the half-column conductors 4008 and 4009 to VDD while the sub-array is in its standby state. Precharging is under the control of a corresponding column precharge clock signal PCBU or PCBL which releases the half-column conductors from their precharge potential by going "low" prior to row selection and recovers the half-column conductors to their precharged potential by going "high" when memory functions in the sub-array are completed.
A schematic diagram of the row termination clock gate circuit is shown in FIG. 5. In the preferred embodiment two such circuits are used to steer the row termination clock signal CRTD to the row clock generator associated with the partially selected sub-array. When the memory is in its standby state the output of each circuit CRTU or CRTL is maintained at VSS owing to PRO being a "high" logic level. At the beginning of the operating cycle, PRO which is initiated by the row enable signal going "low" causes transistor 5001 to become nonconducting. In the circuit associated with the fully selected sub-array the state of column address bit CA8 is such that transistor 5002 is in its nonconducting state when row termination clock signal CRTD goes "high". Thus the effect of CRTD going "high" is blocked by transistor 5002, and the output CRTU or CRTL is maintained at VSS by transistor 5003 which is in its conducting state owing to the state of bit CA8. In the circuit associated with the partially selected sub-array the state of column address bit CA8 is such that transistor 5002 is in its conducting state when CRTD goes "high". Thus the CRTD signal is transferred directly to the output. At the end of the operating cycle, PRO returns to a "high" logic level causing the output of the circuit associated with the partially selected sub-array to return to VSS.
Referring now to FIG. 6 there is shown a schematic diagram of a row decoder interrupt clock generator circuit. The preferred embodiment includes two such circuits, one associated with each sub-array. The inputs and the output of the circuit associated with the lower sub-array are enclosed in parentheses. When the memory is in its standby state, the output of each circuit CRDIBU or CRDIBL is at a boosted potential of greater than VDD+VT. Shortly after the row clock signals CRU and CRL go "high", the row address buffer precharge clock signal PRA also goes "high" to cause the outputs of both circuits to go "low". Under the control of column address signal CA8, the row clock termination gates CRTU and CRTL, discussed above, allow the row terminate clock signal to be applied to only the circuit associated with the partially selected sub-array. Therefore, when the row terminate clock signal goes "high" the output of the circuit associated with the partially selected sub-array returns to a boosted "high" logic level. The output of the circuit associated with the fully selected sub-array remains at a "low" logic level until the master row precharge clock PRO returns "high" at the end of the operating cycle. Illustrative waveforms representing typical behavior of the signals at the inputs and the output of the row decoder interrupt generator circuits are included in FIG. 5. The waveforms illustrate the case in which the upper sub-array is fully selected.
Referring now to FIG. 7 there is shown a schematic diagram of the column precharge clock circuit. Two such circuits are included in the preferred embodiment, one associated with each sub-array. The inputs and the output of the circuit associated with the lower sub-array are enclosed in parentheses. When the memory is in its standby state the output PCBU or PCBL of each circuit is at a boosted "high" logic level of greater than VDD+VT. When the row address bit RA0 goes "high", the output of each circuit goes "low". The output of each circuit returns to a "high" logic level when the corresponding row decoder interrupts clock signal CRDIBU or CRDIBL goes "high". As discussed above in connection with FIG. 6, the row decoder interrupt clock signal associated with the partially selected sub-array goes "high" before that associated with the fully selected sub-array. Therefore, the output of the column precharge circuit associated with the partially selected sub-array returns to the "high" logic level before that of the circuit associated with the fully selected sub-array. Illustrative waveforms representing typical behavior of the signals at the inputs and the output of the column precharge clock generator circuits are included in FIG. 7 for the case in which the upper sub-array is fully selected.
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An MOS dynamic random access memory (RAM) includes an array of memory cells arranged in rows and columns. The array is divided into two or more sub-arrays. During an operating cycle latching of the sense amplifiers in the sub-arrays is staggered to avoid coincidence of current peaks each arising when the sense amplifiers in one of the sub-arrays are simultaneously latched. Latching takes place first in a sub-array in which a cell is selected. Recovery of the column conductors in the sub-arrays is also staggered to avoid coincidence of current peaks each occurring when one of the sub-arrays is recovered. The sub-array in which a cell is selected is recovered last.
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This application is a continuation of application No. 10/461,440, filed Jun. 16, 2003 now U.S. Pat. No. 7,709,777, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to a CMOS imager having an array of image sensing cells and to the driving signals, which operate the cells. In particular, the present invention relates to the use of a variety of pumps in CMOS imagers.
BACKGROUND OF THE INVENTION
CMOS imagers are low cost imaging devices. A fully compatible CMOS sensor technology enabling a higher level of integration of an image array with associated processing circuits would be beneficial to many digital applications such as, for example, in cameras, scanners, machine vision systems, vehicle navigation systems, video telephones, computer input devices, surveillance systems, auto focus systems, star trackers, motion detection systems, image stabilization systems and data compression systems for high-definition television.
CMOS imagers have a low voltage operation and low power consumption; CMOS imagers are compatible with integrated on-chip electronics (control logic and timing, image processing, and signal conditioning such as A/D conversion); CMOS imagers allow random access to the image data; and CMOS imagers have lower fabrication costs as compared with, for example, the conventional CCD since standard CMOS processing techniques can be used. Additionally, low power consumption is achieved for CMOS imagers because only one row of pixels at a time needs to be active during the readout and there is no charge transfer (and associated switching) from pixel to pixel during image acquisition. On-chip integration of electronics is particularly advantageous because of the potential to perform many signal conditioning functions in the digital domain (versus analog signal processing) as well as to achieve a reduction in system size and cost.
A CMOS imager circuit includes a focal plane array of pixel cells, each one of the cells including either a photogate or a photodiode overlying a substrate for accumulating photo-generated charge in the underlying portion of the substrate. A readout circuit is connected to each pixel cell and includes at least an output field effect transistor formed in the substrate and a charge transfer section formed on the substrate adjacent the photogate or photodiode having a sensing node, typically a floating diffusion node, connected to the gate of an output transistor. The imager may include at least one electronic device such as a transistor for transferring charge from the underlying portion of the substrate to the floating diffusion node and one device, also typically a transistor, for resetting the node to a predetermined charge level prior to charge transference.
In a CMOS imager, the active elements of a pixel cell perform the necessary functions of (1) photon to charge conversion; (2) accumulation of image charge; (3) transfer of charge to the floating diffusion node accompanied by charge amplification; (4) resetting the floating diffusion node to a known state before the transfer of charge to it; (5) selection of a pixel for readout; and (6) output and amplification of a signal representing pixel charge. Photo charge may be amplified when it moves from the initial charge accumulation region to the floating diffusion node. The charge at the floating diffusion node is typically converted to a pixel output voltage by a source follower output transistor. The photosensitive element of a CMOS imager pixel is typically either a depleted p-n junction photodiode or a field induced depletion region beneath a photogate. For photodiodes, image lag can be eliminated by completely depleting the photodiode upon readout.
CMOS imagers of the type discussed above are generally known as discussed, for example, in Nixon et al., “256×256 CMOS Active Pixel Sensor Camera-on-a-Chip,” IEEE Journal of Solid-State Circuits, Vol. 31(12) pp. 2046-2050, 1996; Mendis et al, “CMOS Active Pixel Image Sensors,” IEEE Transactions on Electron Devices, Vol. 41(3) pp. 452-453, 1994 as well as U.S. Pat. Nos. 5,708,263 and 5,471,515, which are herein incorporated by reference.
It should be understood that the CMOS imager may include a photodiode or other image to charge converting device, in lieu of a photogate, as the initial accumulator for photo-generated charge.
FIG. 1 illustrates a block diagram for a CMOS imager having a pixel array 200 . FIG. 2A shows a 2×2 portion of pixel array 200 . Pixel array 200 ( FIG. 1 ) comprises a plurality of pixels arranged in a predetermined number of columns and rows. The pixels of each row in array 200 are all turned on at the same time by a row select line, e.g., line 86 (see FIG. 2A ), and the pixel signal output, V out , of each column is selectively clocked onto a column select line, e.g., V out , line 42 (see FIG. 2A ). A plurality of row and column lines are provided for the entire array 200 . The row lines are selectively activated by the row driver 210 in response to row address decoder 220 and the column select lines are selectively activated by the column driver 260 in response to column address decoder 270 . Thus, a row and column address is provided for each pixel. The CMOS imager is operated by the control circuit 250 which controls address decoders 220 , 270 for selecting the appropriate row and column lines for pixel readout, and row and column driver circuitry 210 , 260 which apply driving voltage to the drive transistors of the selected row and column lines.
The operation of the charge collection of the CMOS imager is known in the art and is described in several publications such as Mendis et al., “Progress in CMOS Active Pixel Image Sensors,” SPIE Vol. 2172, pp. 19-29, 1994; Mendis et al., “CMOS Active Pixel Image Sensors for Highly Integrated Imaging Systems,” IEEE Journal of Solid State Circuits, Vol. 32(2), 1997; and Eric R, Fossum, “CMOS Image Sensors: Electronic Camera on a Chip,” IEDM Vol. 95 pages 17-25 (1995) as well as other publications. These references are incorporated herein by reference.
The use and operation of a V cc charge pump for CMOS Imagers is described in U.S. Pat. No. 6,140,630, incorporated in its entirety herein by reference.
Prior art CMOS imagers are not without their shortcomings. For example, these CMOS imagers experience leakage in the transfer gate. Furthermore, it would be desirable to provide a variety of pumps including pixel voltage pump so that the CMOS imager array operating voltage could be different from a periphery supply voltage, positive and/or negative pumps, and substrate pumps.
SUMMARY OF THE INVENTION
The deficiencies of the prior art are overcome by driving one or more of the reset gate, transfer gate (if used) and the row select gate with one or more pumps. A voltage pump provides a higher voltage than the supply voltage V dd to improve the gating operation of the reset, transfer (if used) and row select transistors. By overdriving one or more of the gates of the reset, transfer and row select transistors with the output of a voltage pump, pixel to pixel fabrication differences in electrical characteristics of these transistors can also be avoided. Moreover, if a photogate is used to acquire image charges this too may be overdriven by an output voltage from a voltage pump. The above are examples of gates that can benefit from a voltage pump but should not be taken to be limiting.
Additionally, incorporation of a negative pump to CMOS imager gates such as a reset gate, a row select gate or a transfer gate (if used) allows the current off, I off , performance of these gates to improve as well as the overall image performance of the CMOS imager to improve. This also allows the gate length to shrink and more die/wafer is achieved without sacrificing imager performance. The above are examples of gates that can benefit from a negative pump but should not be taken to be limiting.
Additionally, a substrate pump is described, where the pixels of the array are linked through the substrate.
The above and other advantages and features of the invention will be more clearly understood from the following detailed description which is provided in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a CMOS active pixel sensor chip;
FIG. 2A is a representative pixel layout showing a 2×2 pixel layout according to one embodiment of the present invention;
FIG. 2B shows a generalized signal applied to any gate of a CMOS imager;
FIG. 2C shows a repeating clock voltage which can be applied to any gate of a CMOS imager;
FIG. 2D is an exemplary embodiment of an external V dd supply as the input to five separate internal pumps;
FIG. 2E is an exemplary embodiment of an external V dd supply at a lower voltage as the input to five separate internal pumps;
FIG. 2F is an example of an external V dd supply applied to a positive high voltage pump and a negative low voltage pump;
FIG. 3 is an exploded view of a four transistor (4T) pixel of FIG. 2 using a V aa-pix charge pump in accordance with the present invention;
FIG. 4 is an exploded view of a 3T pixel using a V aa-pix charge pump in accordance with the present invention;
FIG. 5 is an exploded view of a 3T pixel using negative substrate pump in accordance with the present invention;
FIG. 6A is an exploded view of a 4T pixel using a negative gate pump in accordance with the present invention;
FIG. 6B is an example of a timing diagram for a reset gate and a transfer gate;
FIG. 7 is a processor system including a CMOS imager constructed in accordance with any of the embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described with reference to the figures. Reference is now made to FIG. 2A . This figure shows a portion of an active pixel array constructed according to the present invention in which respective charge pumps 300 , 301 and 302 are used to supply the gate voltages for the reset transistor, transfer gate transistor and row select transistors 31 , 29 and 38 . As shown in FIG. 3 , reset transistor 31 is formed by n+ region 30 and n+ region 34 and controlled by RST signal 32 . Transfer transistor 29 is formed by n+ region 26 and n+ region 30 and controlled by TX signal 28 . In FIG. 2A , charge pump 303 is shown for providing a gate voltage to a photogate 24 for charge transfer. Charge pump 304 is shown for providing a voltage pump to a N+junction, which is the V dd pixel supply junction in this case. This figure shows a 2×2 array of pixels for simplification. It should be understood that the invention is directed to a M×N multiple pixel array of any size.
The operation of the FIG. 2A pixel array will now be described. Photodetectors 14 of a row of pixels are coupled via their respective row select transistors 38 to column line 42 . The photodetector selected by a row decoder via line 86 will provide electrical current depending upon the voltage at the gate of source follower transistor 36 supplied by floating diffusion node 30 . As noted, the gate of transistor 36 controls the current through load transistor 39 (not shown in FIG. 2A ) and in consequence the voltage on column line 42 .
Signal ROW SELECT turns row select transistor 38 on. The voltage controlled by the row select signal on line 86 is a charge pump 302 output voltage. Row select line 86 is connected to charge pump 302 to overdrive the row select transistor 38 , that is, the gate voltage of transistor 38 is higher than the V dd supply voltage. In a V dd system, charge pump 302 will supply V pump >V dd volts to the gate of row select transistor 38 . In the absence of a charge pump on the reset gate, the reset gate RST turns on reset transistor 31 , which causes the floating diffusion node 30 to be reset to a potential of V dd −V th , where V th is the threshold voltage of the reset transistor 31 . The actual gate 32 a to transistor 31 is supplied by charge pump 300 to overdrive the gate of the reset transistor 31 with a voltage of V pump >V dd to achieve higher floating diffusion voltage reset value on node 30 at V dd . By having a higher reset voltage available at node 30 , a wider dynamic response range is available for the pixel output signal and variation in the voltage at which the floating diffusion node 30 is reset due to the reset transistor 31 V th variation is reduced.
The photogate 24 is also supplied from a charge pump 303 , ensuring that all possible collected charge for an image signal is stored in the imager substrate beneath the photogate until it is to be transferred out of the collection area.
The FIG. 2A circuit shows use of a transfer gate 28 a and associated transfer transistor 29 . If the CMOS imager cells uses a transfer transistor, then the transfer gate 28 a voltage is also supplied from a charge pump 301 in response to transfer signal TX, once again ensuring that the transfer transistor is overdriven to its on state and eliminating the V th voltage drop which normally occurs. The charge pump on the transfer gate enables improved charge transfer between the photosensor and the floating diffusion. The operation of the FIG. 2A circuit to acquire, transfer and output pixel charge is otherwise as previously described.
The charge pumps 300 and 301 provide voltage to the reset gate 32 a and transfer gate 28 a at a potential which is greater than the supply potential V dd . The pumped voltage enhances the performance of the transfer and reset transistors. In order to turn “on” the various transistors of the pixel array, a gate voltage to the transistor must exceed a source or drain voltage (depending on the type of transistor) such that V pump >V dd . However, the threshold voltage (V th ) may differ for each transistor of a pixel array due to manufacturing imperfections. As a consequence, when all transistors of the array are turned “on” or “off” using the voltage supply potentials to supply control signals to the gates of the transistors, some transistors which are turned “on” are more “on” than other transistors thereby inconsistently transferring and/or amplifying the pixel charges transferred to the pixel output line 42 . Likewise, some of the transistors which are turned “off” are more “off” than other transistors causing leakage. This is reflected as an improper output of signals reflecting the charges collected by the photodetector circuit 14 .
The charge pumps 300 , 301 and 302 help to overcome the inconsistent on/off threshold voltages (V th ) of the transistors by overdriving the gates with voltages which ensure that they turn on or off as required, regardless of manufacturing inconsistencies. The charge pump 303 ensures that the maximum possible charges are collected in the collection region beneath the photogate.
While multiple charge pumps 300 , 301 , 302 , 303 and 304 are shown in FIG. 2A for the entire CMOS pixel array, it should be understood that a single charge pump having multiple controlled output voltages may be used for the entire CMOS imager and for associated logic circuits. Also, individual charge pumps may be used for different portions of the imager circuit and for the associated logic circuits. Also, while the charge pumps 300 , 301 , 302 , 303 , 304 are shown supplying voltage for the reset gate, the transfer gate, the row select gate and the photogate and V dd supply, it should be understood that a charge pump may be used for one or more of these gates to achieve a benefit over conventional CMOS imagers which do not use a charge pump. It is understood that the present invention is not limited to the examples described herein. More complex 5T, 6T, 7T CMOS imagers are contemplated supporting global shutter, high dynamic range, and dual conversion gain applications. Pumped gates or diffusion will be advantageous in these applications as well. That is, a common charge pump source could be used to supply the high state voltage level to all pumped clocked gates (e.g. reset, row select, transfer, photogate and V dd supply) so long as V pump >V dd .
The particular construction of the charge pump is not critical to the invention and many circuits circuit can be used. Representative output voltages of charge pumps 300 , 301 , 302 and 303 are 4.0, 4.0 and 4.0, respectively, for a 3.3 volt V dd supply and assuming that the V d , of each of these transistors is less than 0.7 volts. While it is advantageous to have V pump ≧V dd V th it is not required or limiting. The photogate pump when turned on by the positive clock pulse can be at a pumped voltage such that V pump >V dd . When the clock voltage applied to the photogate returns to its low or off-state voltage that off-state may be pumped low so that the gate sees a negative voltage. All of the other gates of the CMOS imager may benefit from having a negative pumped voltage applied to turn the transistor off. The negative voltage can be any value so long as it is lower than a reference ground (0V) potential. It should be understood that the output of voltage charge pumps 300 , 301 , 302 , 303 and 304 may vary, individually, depending upon the V dd and/or V ss supply as well as the V d , of the individual transistors. For collecting charge in the photogate, the charge pump 303 is configured to supply an output voltage V pgp where V pgp is greater than input voltage V dd .
FIG. 2B shows a generalized signal applied to any gate of a CMOS imager. FIG. 2C shows a repeating clock voltage which can be applied to any gate. The high state voltage 205 is pumped above V dd (V pump >V dd ). The clock voltage applied returns to a low or off-state voltage 215 resulting in a pumped voltage that is below ground (0V).
The above discussion has described the circuit for an exemplary 2×2 pixel shown in FIG. 2A . It is desirable for an additional pump circuit to supply voltage V aa-pix to diffusion node 34 and through diffusion node 34 to floating diffusion node 30 so that the CMOS imager operating voltage could be different from a periphery supply voltage. The pump circuit includes a V aa-pix , charge pump, which is supplied by external power supply V dd . The pump circuit outputs a new supply voltage that is booted. The new booted V aa-pix supply then is used to supply all of the pixels. This permits the CMOS imager array to operate at a different voltage than the periphery.
As described above from V dd a voltage V aa-pix is created using a pump circuit such that V aa-pix , >V dd . The present invention also encompasses the situation where V pump <V dd using a regulated power supply that is less than the supplied voltage source V dd . In the alternative V dd could be a high state voltage such as depicted in FIG. 2B . From this high state voltage a regulated voltage V reg can be created, where the regulated voltage is a low state voltage. In this instance, V dd could supply the array and V reg could supply the periphery where 0<V reg <V dd .
FIG. 2D is an example of an external V dd supply 115 as the input to five separate internal pumps, V aa-pix pump 120 , photogate pump 125 , row select pump 130 , transfer gate pump 135 and reset pump 140 . These could be pumps to independently supply V pump >V dd and/or they could supply a negative off-state voltage to the various shown clocked voltages driving the array transistor gates and diffusions of imager array 110 . A regulator 145 is also shown providing a regulated voltage to the imager circuits in the periphery, such as periphery circuit 1 ( 150 ). If the external supply, is, for example, 3.3 volts, then the five shown array pumps can produce clocked voltages to the array such that V pump >V dd . In our examples if the V th of the array transistors is 0.7 volts then a reasonable V pump high voltage to the array gates would be 4.0 volts. The pumps could also include negative pumps to control the off-state voltage of the voltage clocks supplying the array circuits. To conserve power, in this example, the regulator is supplied at V reg <V dd to support the circuits in the imager periphery. In this example V reg is the range of 2.5 V to 1.2 V might be reasonable. Periphery circuit 2 ( 155 ) in this example is driven directly by the V dd external supply. For example, periphery circuit 1 ( 150 ) could be digital circuits and periphery circuit 2 ( 155 ) could be analog circuits. In this example, the imager array 110 is provided with voltages greater than or equal to the supply voltage for the “high state” or “on” voltage of the array circuits. The periphery circuits 150 , 155 are provided with voltages less than or equal to the supply voltage.
In FIG. 2E the external supply could be at a lower voltage of 2.5 volts. In this case it would be advantageous to have a periphery circuit pump 160 to increase the voltage supply to the analog circuits of periphery circuits 2 ( 155 ). It would also be possible to have a lower regulated voltage, V reg <V dd (1.2. 1.5, 1.8, 2.0, 2.2 V) supplying the digital circuits in periphery circuits 1 .
FIG. 2F is an example of an external V dd supply 115 applied to a positive high voltage pump 190 , a negative low voltage gate pump 195 and a negative substrate pump 197 . The negative substrate pump 197 supplies voltage to p-well and p-substrate 199 . The positive high voltage pump 190 and the negative low voltage pump 195 each supply a reset driver 165 , a row select driver 175 , a transfer gate driver 180 , a photogate driver 185 and a V aa-pix driver 170 , each of which is coupled to the imager array 110 . In this example, the positive high voltage pump 190 also supplies voltage to periphery circuits 2 ( 155 ). Periphery circuits 1 ( 150 ) is supplied directly by the external V dd supply 115 .
The advantageous operation of CMOS imagers is described using a four transistor (4T) CMOS imager. Actual CMOS imagers may contain fewer or more than four transistors. It is understood that the use of 4T CMOS imagers is not meant to limit the present invention to a 4T embodiment. If the CMOS imager requires more than four transistors, then some of those additional transistors will show improved performance by having their own pump.
FIG. 3 is an exploded view of an exemplary 4T pixel of the present invention illustrated in FIG. 2A , where the pixel is formed using re-channel (n-ch) devices. Like components are labeled the same as in FIG. 2A . N+ type region 34 is actively driven by V aa-pix charge pump 100 , which gets its supply of voltage (charge) from V dd 105 . A V aa-pix charge pump allows the CMOS imager to operate at higher voltages and, thus, achieve better image performance. The V aa-pix charge pump permits lower voltage periphery and can be coupled with shorter transistor lengths to improve periphery performance. N+ type region 30 (floating diffusion node) is also supplied by V aa-pix charge pump 100 through N+ diffusion node 34 via reset transistor 31 . Photodiode (PD) 26 is an n-type diffusion region. The n-ch devices are in a p-well. Substrate contact 20 may be ground (0V) or negative if a negative substrate pump is provided. The present invention also applies to an array containing n-ch transistors.
FIG. 4 is an exploded view of an exemplary 3T pixel of the present invention formed using n-ch devices. The 3T transistor pixel of FIG. 4 is similar to the 4T pixel of FIG. 3 except that there is no transfer transistor used in the 3T implementation. FIG. 4 is appropriate for a V aa-pix charge pump for any CMOS imager, 2T, 3T, 4T, 5T, or any type. PD 405 is n-type diffusion region, RST signal 410 controls a reset transistor formed by PD 405 and diffusion region 415 , which is an n+ diffusion region. N+ diffusion region 420 is actively driven by V aa-pix charge pump 425 , which gets its supply of voltage (charge) from V dd 430 . The n-ch devices are in a p-well. The present invention also applies to an array containing p-ch transistors.
FIG. 5 is an exploded view of an exemplary 3T pixel using a negative substrate pump. The pixel is formed using n-ch devices. The PD 505 is diffusion n-type; diffusion region 515 is diffusion type n+. The diffusion region 520 under the substrate pump contact 526 is p+. Negative V substrate pump 525 is also connected to ground 530 and the external power supply, V dd . Reset signal (RST) 510 controls the reset transistor formed by n-type diffusion region 505 and n+ diffusion region 515 , which supplies V aa-pi . The n-ch devices are in a p-well. All p-wells in the entire array are linked and the p-well attached to the negative substrate pump is connected to the array p-wells. The present invention also applies to an array containing p-ch transistors.
In another embodiment, a negative gate pump supplies a negative voltage, which is applied to gates such as reset and transfer gates. Specifically, FIG. 6A is an exploded view of a 4T pixel of the present invention, where the pixel is formed using n-ch devices. The gates ( 28 a , 32 a ) of transfer transistor 29 and reset transistor 31 are driven by negative gate pump 650 via a transfer voltage driver 655 and a reset voltage driver 660 respectively. which gets it supply of voltage from V dd 105 . Both the transfer gate and the reset gate could see a negative pumped off-state voltage but they would have separate clocks in that instance. In this embodiment, the negative gate pump operates to drive the gate “off” harder in n-ch devices. The negative gate pump could also be applied to the row select gate or any gate on a CMOS imager and is not limited by the exemplary embodiments described herein. Typical gates used in CMOS imagers include but are not limited to reset devices, transfer devices, global shutter devices, storage devices, high dynamic range devices and lateral overflow drain devices. FIG. 6B is an example of a timing diagram for a reset gate and a transfer gate. In each case, the gates are supplied with a negative pumped voltage.
The present invention can be utilized within any integrated circuit which receives an input signal from an external source. FIG. 7 illustrates an exemplary processing system 600 which may utilize a processor circuit comprising a CMOS imager constructed in accordance with any of the embodiments of the present invention disclosed above in connections with FIGS. 1-6B . The processing system 600 includes one or more processors 601 coupled to a local bus 604 . A memory controller 602 and a primary bus bridge 603 are also coupled the local bus 604 . The processing system 600 may include multiple memory controllers 602 and/or multiple primary bus bridges 603 . The memory controller 602 and the primary bus bridge 603 may be integrated as a single device 606 .
The memory controller 602 is also coupled to one or more memory buses 607 . Each memory bus accepts circuits such as 608 which include at least one pixel 631 using the present invention. The imaging device, e.g. a CMOS Imager, may also be integrated with a memory card or a memory module and a CPU in accordance with the present invention. Examples of memory modules include single inline memory modules (SIMMs) and dual inline memory modules (DIMMs). The imaging device 608 may include one or more additional devices 609 (not shown). For example, in a SIMM or DIMM, the additional device 609 might be a configuration memory, such as a serial presence detect (SPD) memory. The memory controller 602 may also be coupled to a cache memory 605 . The cache memory 605 may be the only cache memory in the processing system. Alternatively, other devices, for example, processors 601 may also include cache memories, which may form a cache hierarchy with cache memory 605 . If the processing system 600 include peripherals or controllers which are bus masters or which support direct memory access (DMA), the memory controller 602 may implement a cache coherency protocol. If the memory controller 602 is coupled to a plurality of memory buses 607 , each memory bus 607 may be operated in parallel, or different address ranges may be mapped to different memory buses 607 .
The primary bus bridge 603 is coupled to at least one peripheral bus 610 . Various devices, such as peripherals or additional bus bridges may be coupled to the peripheral bus 610 . These devices may include a storage controller 611 , an miscellaneous I/O device 614 , a secondary bus bridge 615 , a multimedia processor 618 , and an legacy device interface 620 . The primary bus bridge 603 may also coupled to one or more special purpose high speed ports 622 . In a personal computer, for example, the special purpose port might be the Accelerated Graphics Port (AGP), used to couple a high performance video card to the processing system 600 .
The storage controller 611 couples one or more storage devices 613 , via a storage bus 612 , to the peripheral bus 610 . For example, the storage controller 611 may be a SCSI controller and storage devices 613 may be SCSI discs. The I/O device 614 may be any sort of peripheral. For example, the I/O device 614 may be an local area network interface, such as an Ethernet card. The secondary bus bridge may be used to interface additional devices via another bus to the processing system. For example, the secondary bus bridge 616 may be an universal serial port (USB) controller used to couple USB bus devices 617 via to the processing system 600 . The multimedia processor 618 may be a sound card, a video capture card, or any other type of media interface, which may also be coupled to one additional devices such as speakers 619 . The legacy device interface 620 is used to couple legacy devices, for example, older styled keyboards and mice, to the processing system 600 . In addition to pixel 631 which may contain a pump circuit of the present invention multimedia processor 681 of FIG. 7 may also utilize an imaging device of the present invention including the CPU 601 .
The processing system 600 illustrated in FIG. 7 is only an exemplary processing system with which the invention may be used. While FIG. 7 illustrates a processing architecture especially suitable for a general purpose computer, such as a personal computer or a workstation, it should be recognized that well known modifications can be made to configure the processing system 600 to become more suitable for use in a variety of applications. For example, many electronic devices which require processing may be implemented using a simpler architecture which relies on a CPU 601 coupled to imaging device 608 and/or memory buffer devices 604 . These electronic devices may include, but are not limited to audio/video processors and recorders, gaming consoles, digital television sets, wired or wireless telephones, navigation devices (including system based on the global positioning system (GPS) and/or inertial navigation), and digital cameras and/or recorders. The modifications may include, for example, elimination of unnecessary components, addition of specialized devices or circuits, and/or integration of a plurality of devices.
In another embodiment, a negative pump supplies a negative voltage, which is applied to gates such as reset and transfer gates. In this embodiment, the negative pump operates to drive the gate “off” harder in n-ch devices.
In an alternative embodiment, a positive pump supplies a positive voltage, which is applied to gates such as reset and transfer gates. In this embodiment, the positive pump operates to drive the gate “off” harder in p-ch devices.
While the invention has been described and illustrated with reference to specific exemplary embodiments, it should be understood that many modifications and substitutions can be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims.
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A pixel for an imaging device is described. The pixel includes a photosensitive device provided within a substrate for providing photo-generated charges, a circuit associated with the photosensitive device for providing at least one pixel output signal representative of the photo-generated charges, the circuit includes at least one operative device that is responsive to a first control signal during operation of the associated circuit and a pump circuit. The pump circuit may include substrate pumps, charge pumps and/or voltage pumps. The pixel may also be embedded in an imaging system.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of International Patent Application No. PCT/CN2005/000872 with an international filing date of Jun. 17, 2005, designating the United States, now pending, which claims priority benefits to the Chinese Patent Application No. 200410051879.9 filed Oct. 13, 2004. This application further claims priority benefits pursuant to 35 U.S.C §119 and the Paris Convention Treaty to the Chinese Patent Application No. 200610156824.3 filed Nov. 11, 2006 The contents of all of the above-mentioned specifications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to variable attenuators in the electronics and communication fields, and more particularly, to microstrip variable attenuators suitable for use in various high frequency and/or microwave circuits and systems.
2. Description of the Related Art
In the family of electronic components, the variable attenuator is one of the common and basic components in electrical circuits and systems. The existence of a variable attenuator makes the fabrication of electrical circuits and the debugging of systems more flexible and convenient. Currently, the variable attenuator is being widely used in circuits and systems with operating frequencies below a few hundred megahertz (MHz). For example, in CATV (Community Antenna Television) systems and microwave circuits, the variable attenuator is used for testing, regulating power levels, increasing isolation, etc. However, as the operating frequency is in a comparatively high frequency band, the current three-dimensional variable attenuator which is made of a contact spring, a slide block, a guide screw, and so on, has the drawbacks of large parasitic parameters and comparatively poor high frequency characteristics.
SUMMARY OF THE INVENTION
In view of the above-described problems, it is one objective of the invention to provide a variable attenuator with good wide band characteristics that is suitable for use in high frequency and/or microwave circuits and systems.
In accordance with one objective of the invention, provided is a variable attenuator comprising: a base 11 , a film resistor 1 located on the base 11 , and an input terminal 9 and an output terminal 10 connected to the two ends of the film resistor 1 , respectively; the two ends of the film resistor 1 are also electrically connected to one end of a film resistor 6 and one end of a film resistor 7 , respectively; the other ends 14 of the film resistor 6 and film resistor 7 are electrically connected to one end of the film resistor 2 , and the other end of the film resistor 2 is electrically connected to a ground terminal 13 ; the variable attenuator further comprises a conductive sheet 3 and a conductive sheet 4 that can be electrically connected to the film resistor 1 and the film resistor 2 for changing the resistance values thereof; the variable attenuator further comprises an insulator 12 for fixing the conductive sheet 3 and the conductive sheet 4 disposed thereon.
In a class of this embodiment, the resistance value of the film resistor 6 is equal to that of the film resistor 7 .
In a class of this embodiment, the position of the conductive sheet 3 and the conductive sheet 4 can be changed when moving the insulator 12 so as to change the contact area between the conductive sheet 3 and the film resistor 1 and that between the conductive sheet 4 and the film resistor 2 .
In a class of this embodiment, the conductive sheet 3 , the conductive sheet 4 , the film resistor 1 , and the film resistor 2 can be in the shape of an arc or rectangular; and the conductive sheet 3 and the conductive sheet 4 are also film resistors.
In a class of this embodiment, the common plane of the film resistor 1 and the conductive sheet 3 is without limitation in the same plane as that of the film resistor 2 and the conductive sheet 4 ; and the base 11 is a multi-layered base.
In a class of this embodiment, the force to change the geometrical position of the conductive sheet 3 and the conductive sheet 4 is a mechanical manual force, an automatic controlled mechanical force, an electromagnetic force, a force produced by heat or temperature, a force produced by the flow, expansion, or contraction of a liquid, or a force initiated by an optoelectronic excitation process.
In a class of this embodiment, the configuration of the variable attenuator is of a surface mount type, a pin leg lead type, or a patch cord type.
In a class of this embodiment, a silicon rubber film conductive in the vertical direction is added between the base 11 and the insulator 12 .
In a class of this embodiment, a groove is disposed on the insulator 12 ; the conductive sheet 3 and the conductive sheet 4 are located inside of the groove; and an elastic substance is added between the conductive sheet 3 and the conductive sheet 4 within the groove.
In a second embodiment of the invention provided is a microstrip variable attenuator, comprising: a base 101 , a film resistor 105 located on the base, an input terminal 102 and an output terminal 103 connected to the two ends of the film resistor 105 ; the two ends of the film resistor 105 are further electrically connected to one end of a film resistor 106 and one end of a film resistor 107 , respectively; the other ends of the film resistor 106 and the film resistor 107 are electrically connected to a ground terminal 109 ; the variable attenuator of the invention further comprises a conductive sheet 110 , a conductive sheet 111 , and a conductive sheet 112 that can be electrically contacted by the film resistor 105 , the film resistor 106 , and the film resistor 107 , respectively, and are used to change the resistance values of the film resistor 105 , the film resistor 106 , and the film resistor 107 , respectively; the variable attenuator of the invention further comprises an insulator 113 , on which the conductive sheet 105 , the conductive sheet 106 , and the conductive sheet 106 are fixed.
In a class of this embodiment, the resistance value of the film resistor 106 is equal or close to that of the film resistor 107 .
In a class of this embodiment, the position of the conductive sheet 110 , the conductive sheet 111 , and the conductive sheet 112 can be changed when moving the insulator 113 so as to change the contact area between the conductive sheet 110 and the film resistor 105 , that between the conductive sheet 111 and the film resistor 106 , and that between the conductive sheet 112 and the film resistor 107 .
In a class of this embodiment, the conductive sheet 110 , the conductive sheet 111 , the conductive sheet 112 , the film resistor 105 , the film resistor 106 , and the film resistor 107 are in the shape of an strip arc or rectangular; the conductive sheet 110 , the conductive sheet 111 , and the conductive sheet 112 are also film resistors; the insulator 113 is a PCB board with conductive sheets disposed thereon, wherein the PCB board can be in the shape of a circle with an arc mouth formed on its peripheral edge.
In a class of this embodiment, the force to change the geometrical position of the conductive sheet 105 , the conductive sheet 106 , and the conductive sheet 107 is a mechanical manual force, an automatic controlled mechanical force, an electromagnetic force, a force produced by heat or temperature, a force produced by the flow, expansion, or contraction of a liquid, or a force initiated by an optoelectronic excitation process.
In a third embodiment of the invention provided is a microstrip variable attenuator, comprising: a base 229 , a film resistor 219 , a film resistor 220 , a film resistor 221 , an input terminal 216 and an output terminal 217 located on the base; the input terminal 216 is connected to one end of the film resistor 219 , the other end of the film resistor 219 is connected to one end of the film resistor 220 , and is connected to one end of the film resistor 221 , the other end of the film resistor 221 is connected to the ground terminal 222 ; the other end of the film resistor 220 is connected to the output terminal 217 ; the variable attenuator of the invention further comprises a conductive sheet 223 , a conductive sheet 224 , and a conductive sheet 225 that can be electrically contacted by the film resistor 219 , the film resistor 220 , and the film resistor 221 , respectively, and are used to change the resistance values of the film resistor 219 , the film resistor 220 , and the film resistor 221 , respectively; the variable attenuator of the invention further comprises an insulator 227 , on which the conductive sheet 223 , the conductive sheet 224 , and the conductive sheet 225 are fixed.
In a class of this embodiment, the resistance value of the film resistor 219 is equal or is close to that of the film resistor 220 .
In a class of this embodiment, the position of the conductive sheet 223 , the conductive sheet 224 , and the conductive sheet 225 can be changed when moving the insulator 227 so as to change the contact area between the conductive sheet 223 and the film resistor 219 , that between the conductive sheet 224 and the film resistor 220 , and that between the conductive sheet 225 and the film resistor 221 .
In a class of this embodiment, the conductive sheet 223 , the conductive sheet 224 , the conductive sheet 225 , the film resistor 219 , the film resistor 220 , and the film resistor 221 are in the shape of an strip arc or rectangular; the conductive sheet 223 , the conductive sheet 224 , the conductive sheet 225 are also film resistors; the insulator 227 is a PCB board with conductive sheets disposed thereon, wherein the PCB board is in the shape of a circle with an arc mouth formed on its peripheral edge.
In a class of this embodiment, the force to change the geometrical position of the conductive sheet 223 , the conductive sheet 224 , and the conductive sheet 225 is a mechanical manual force, an automatic controlled mechanical force, an electromagnetic force, a force produced by heat or temperature, a force produced by the flow, expansion, or contraction of a liquid, or a force initiated by an optoelectronic excitation process.
Therefore, the variable attenuator according to the invention provides the following advantages:
(a) since a microstrip base structure is adopted, the range of useful frequencies for the variable attenuator is very wide; the continuous variable attenuation of a signal in the high frequency and microwave frequency range can be realized;
(b) it has a small size, is easy to adjust, and is suitable for use in various miniaturized circuits and communication circuits;
(c) it has a simple structure, and a low fabrication cost;
(d) it is suitable for various equalization circuits;
(e) it is suitable for various isolation circuits;
(f) it is suitable for various regulating circuits, controlling circuits, stabilizing circuits, and circuits for adjusting the amount of coupling;
(g) it is suitable for circuits where high attenuation is required, systematic error of an actual circuit is large, and regulation of all parts is needed to satisfy characteristics of overall circuits;
(h) it has a low insertion loss; and
(i) it can serve in adjusting and testing instruments for research and development work in laboratories.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described hereinafter with reference to accompanying drawings, in which:
FIG. 1 is a structural diagram of a variable attenuator in accordance with one embodiment of the invention;
FIG. 2 is an exploded view thereof;
FIG. 3 is an equivalent electric diagram thereof;
FIG. 4 shows a theoretical characteristic variation curve of the resistance value of the film resistor 1 and the film resistor 2 , when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force, in accordance with one embodiment of the invention;
FIG. 5 shows an attenuation variation curve of a variable attenuator in accordance with one embodiment of the invention when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force;
FIG. 6 is a structural diagram of a variable attenuator in accordance with a second embodiment of the invention;
FIG. 7 is a structural diagram of a conductive sheet thereof;
FIG. 8 is an equivalent electric diagram thereof;
FIG. 9 shows a theoretical characteristic variation curve of the resistance value of the film resistor 105 , the film resistor 106 , and the film resistor 107 when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force, in accordance with a second embodiment of the invention;
FIG. 10 shows an attenuation variation curve of a variable attenuator in accordance with a second embodiment of the invention when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force;
FIG. 11 is a structural diagram of a variable attenuator in accordance with a third embodiment of the invention;
FIG. 12 is a structural diagram of a conductive sheet thereof;
FIG. 13 is an equivalent electric diagram thereof;
FIG. 14 shows a theoretical characteristic variation curve of the resistance value of the film resistor 219 , the film resistor 220 , and the film resistor 221 when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force, in accordance with a third embodiment of the invention; and
FIG. 15 shows an attenuation variation curve of a variable attenuator in accordance with a third embodiment of the invention when the insulator drives the conductive sheet to rotate clockwise as the variable attenuator is adjusted by an external force.
FIG. 16 shows a graph of how the first effective resistance value changes when the first conductive sheet rotates with respect to the first resistor and how the second effective resistance value changes in certain embodiments when the second conductive sheet rotates with respect to the second resistor.
FIG. 17 shows a graph of how the third effective resistance value changes in certain embodiments when the third conductive sheet rotates with respect to the third resistor.
FIG. 18 shows a graph of how the third effective resistance value changes in certain embodiments when the third conductive sheet rotates with respect to the third resistor.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-2 , a variable attenuator according to the first embodiment of the invention comprises a base 11 , an input terminal 9 located on the base 11 , an arc shaped microstrip signal line 5 with one end connected to the input terminal 9 , an arc shaped film resistor 1 with one end connected to the other end of the microstrip signal line 5 , and an output terminal 10 connected to the other end of the film resistor 1 . In addition, the two ends of the film resistor 1 are electrically connected to one end of a film resistor 6 and one end of a film resistor 7 , respectively; the other ends 14 of the film resistor 6 and film resistor 7 are both electrically connected to one end of the film resistor 2 , the other end of the film resistor 2 is connected to a ground terminal 13 , or is connected to the ground terminal 13 via a microstrip signal line 8 . In certain embodiments of the invention, the film resistor 1 , the film resistor 2 , the film resistor 6 , and the film resistor 7 are all printed film resistors with the bottom side connected to the base 11 and the top side made of conductive and non-insulated material.
Particularly, the resistance value of the film resistor 6 is equal to that of the film resistor 7 . Generally, the film resistor 6 and the film resistor 7 are film resistors having the same resistance value, Zo, at the input and output terminals, for example, 50 Ohms. A conductive sheet 3 for contact short-circuiting, and having the same shape as the microstrip signal line 5 , is located above the top side of the microstrip signal line, and is fixed on the insulator 12 . The insulator 12 is a forced displacement board, and is further fixed with a conductive sheet 4 . The conductive sheet 3 and the conductive sheet 4 are fixed at the bottom side of the insulator 12 (namely the forced displacement board), respectively. The function of the conductive sheet 3 is to adjust the effective resistance value of the film resistor 1 , while that of the conductive sheet 4 is to adjust the effective resistance value of the film resistor 2 . The conductive sheet 3 does not contact with the conductive sheet 4 . The conductive sheet 3 and the conductive sheet 4 rotate with the rotation of the insulator 12 . For example, when the insulator 12 (the forced displacement board) rotates clockwise, the conductive sheet 3 rotates on and in contact with the microstrip signal line 5 and the film resistor 1 simultaneously. The contact area between the conductive sheet 3 and the film resistor 1 increases so that the resistance value of the film resistor 1 decreases. The conductive sheet 4 rotates on the microstrip signal line 8 and the film resistor 2 simultaneously. The contact area between the conductive sheet 4 and the film resistor 2 decreases so that the resistance value of the film resistor 2 increases. Through the change in the geometric area, namely the change in the contact area between the conductive sheet and the film resistor, the actual effective resistance values of the film resistor 1 and the film resistor 2 are changed.
When the insulator 12 (forced displacement board) rotates clockwise, it is preferred that the maximum rotation angle of the insulator 12 be maintained so as to make the conductive sheet 3 nearly or totally short-circuit the film resistor 1 ; the length (arc length) of the conductive sheet 3 should cover or nearly cover the film resistor 1 , and should be prevented from contacting the film resistor 2 . When the conductive sheet 4 rotates clockwise, the conductive sheet 4 needs to be designed not to contact the microstrip signal line 5 and the input terminal 9 . Similarly, when the insulator 12 (forced displacement board) rotates counter-clockwise, the maximum rotation angle of the conductive sheet 4 needs to be maintained so as to avoid the conductive sheet 4 from contacting the output terminal 10 . When the conductive sheet 3 rotates counter-clockwise, the conductive sheet 3 needs to be designed not to contact the ground terminal 13 .
The conductive sheet 3 and the conductive sheet 4 can also be film resistors, which overlap and are electrically connected, and can be regarded as two resistors in parallel. Similarly, the resistance value of the film resistor can be changed and the same effect can be achieved. However, it is required that the conductive sheet 3 can only be used to electrically contact the film resistor 1 to change the resistance value thereof, and does not directly contact other microstrip signal lines or film resistors. It is required that the conductive sheet 4 can only be used to electrically contact the film resistor 2 to change the resistance value thereof, and does not directly contact other microstrip signal lines or film resistors. Therefore, the film resistor 1 and the film resistor 2 can be fabricated on the base 11 in different layers from other microstrip signal lines, the input and output terminals, and other film resistors so as to keep the basic principle and structure of the variable attenuator.
The co-plane of the film resistor 1 and the conductive sheet 3 is, without limitation, in the same plane as that of the film resistor 2 and the conductive sheet 4 .
FIG. 3 illustrates the basic principle diagram of the variable attenuator of the invention. The operation principle of the variable attenuator is equivalent to a continuous variable bridge T-shaped attenuator, which is a symmetric wide band network with interchangeable input and output terminals.
FIG. 4 illustrates an ideal theoretical variation curve of the film resistor 1 and the film resistor 2 when the insulator 12 (forced displacement board) rotates clockwise. The variation trend of the resistance value of the film resistor 1 is opposite to that of the film resistor 2 .
FIG. 5 illustrates a line showing the attenuation amount of the variable attenuator fabricated according to the curve of FIG. 4 when the insulator 12 (forced displacement board) rotates clockwise. During designing and fabricating, the film resistor 1 and the film resistor 2 are chosen according to the curve of FIG. 4 so as to realize variation in the attenuation amount, which is required when the displacement of the variable attenuator is changed.
When the resistance value of one of the film resistors increases, the resistance value of the other film resistor decreases, and vice versa. Based on the variation trend of FIG. 3 , a continuous variable attenuator can be fabricated.
The variable attenuator can be made into various package types, such as a surface mount type, a pin leg lead type, or a patch cord type.
In addition, in accordance with the invention, a silicon rubber film that is conductive in the vertical direction can be added between the base 11 and the insulator 12 so as to stabilize the contact between the film resistor and the conductive sheet, and thereby, to avoid wear between the film resistor and the conductive sheet.
Besides, in accordance with the invention, a groove can also be processed on the insulator 12 , and the conductive sheet 3 and the conductive sheet 4 are located inside of the groove. An elastic substance having a negligible influence on the high frequency and microwave characteristics is added between the conductive sheet 3 and the conductive sheet 4 acting for contact short-circuiting within the groove so as to stabilize the contact between the film resistor and the conductive sheet, and thereby, to avoid wear between the film resistor and the conductive sheet.
The main feature of the variable attenuator of the invention is that in one plane (it can be multi layered), through the short-circuiting function of the conductive sheets, the resistance value of the film resistor 1 and the film resistor 2 can be simultaneously and flexibly changed in opposite directions. The conductive sheet 3 , the conductive sheet 4 , the film resistor 1 , and the film resistor 2 can be in the geometric shape of an arc, rectangular, or other shape. The variable attenuator of the invention is miniaturized and cost-effective, and is suitable for use in the upper microwave frequency band.
FIGS. 6-7 illustrate the structural diagram of the microstrip variable attenuator and the structural diagram of the conductive sheet in accordance with the second embodiment of the invention, respectively, comprising: a base 101 , an input terminal 102 and an output terminal 103 located on the base 101 , an arc shaped strip film resistor 105 , an arc shaped strip film resistor 106 , an arc shaped strip film resistor 107 , a microstrip signal line 104 , a microstrip signal line 108 , a ground terminal 109 for the connection of microstrip signal lines. The microstrip variable attenuator further comprises a conductive sheet 110 , a conductive sheet 111 , and a conductive sheet 112 disposed on an insulator 113 . The insulator can also be a PCB board with conductive sheets disposed thereon. The PCB board can be in the shape of a circle for easy regulation. An arc mouth 115 is formed on the peripheral edge of the circle so as to limit the range of rotation regulation.
The base can be a ceramic base or a PCB board that is convenient to use with microstrip resistors.
One end of the microstrip signal line 104 is connected to the input terminal 102 , while the other end is connected to the film resistor 105 , and to one end of the film resistor 106 via the microstrip signal line 108 . The other end of the film resistor 105 is connected to the output terminal 103 . The other end of the film resistor 106 is connected to the ground terminal 109 . One end of the film resistor 107 is connected to the output terminal 103 via the microstrip signal line 108 , while the other end is connected to the ground terminal 109 .
In certain embodiments of the invention, the film resistor 105 , the film resistor 106 , the film resistor 107 are all printed film resistors with the bottom side connected to the base 101 and the top side made of conductive and non-insulated material.
Particularly, the resistance value of the film resistor 106 is equal or close to that of the film resistor 107 .
The base can be multi-layered, the film resistors and the conductive sheets can be in the shape of a strip arc, rectangular, or other shape. Particularly, the shape of the conductive sheet is the same as or similar to that of the film resistor.
The resistance value, Zo, is generally designed to be equal at the input and output terminals, for example, about 50 Ohms. The PCB board 113 and the base 101 share the same center 114 . The PCB board 113 is installed on the base according to the position of the arc mouth 115 , the side fixed with conductive sheets of the PCB board meets the base; a conductive sheet 110 for contact short-circuiting, and having the same shape as the microstrip signal line 104 , is located above the top side of the microstrip signal line 104 , and is fixed on the PCB board 113 , which is further fixed with a conductive sheet 111 and a conductive sheet 112 .
The function of the conductive sheet 110 is to adjust the resistance value of the film resistor 105 . The function of the conductive sheet 111 is to adjust the resistance value of the film resistor 106 , while that of the conductive sheet 112 is to adjust the resistance value of the film resistor 107 . The conductive sheet 110 , the conductive sheet 111 , and the conductive sheet 112 rotate with the rotation of the PCB board 113 . For example, when the PCB board 113 rotates clockwise by an external force, the conductive sheet 110 rotates on and in contact with the microstrip signal line 104 towards the film resistor 105 , so that the contact area between the conductive sheet 110 and the film resistor 105 increases, and thus the resistance value of the film resistor 105 decreases. The conductive sheet 111 rotates on and in contact with the film resistor 106 towards the microstrip signal line 108 , so that the contact area between the conductive sheet 111 and the film resistor 106 decreases, and thus the resistance value of the film resistor 106 increases. The conductive sheet 112 rotates on and in contact with the film resistor 107 towards the microstrip signal line 108 so that the contact area between the conductive sheet 112 and the film resistor 107 decreases, and thus the resistance value of the film resistor 107 increases. Through the change in the geometric area, namely the change in the contact area between the conductive sheet and the film resistor, the actual effective resistance values of the film resistor 105 , the film resistor 106 , and the film resistor 107 can be changed.
An arc mouth 115 is formed on the peripheral edge of the PCB board 113 to limit the range of the rotation regulation. When the PCB board 113 rotates clockwise, it is preferred that the maximum rotation angle of the PCB board 113 be maintained so as to make the conductive sheet 110 nearly or totally short-circuit the film resistor 105 , and the length (arc length) of the conductive sheet 110 should cover or nearly cover the film resistor 105 . It is preferred that the length (arc length) of the conductive sheet 111 should cover or nearly cover the film resistor 106 . It is preferred that the length (arc length) of the conductive sheet 112 should cover or nearly cover the film resistor 107 . Moreover, the spacing between the film resistor 106 and the film resistor 107 should be considered so that the conductive sheet 111 does not contact the film resistor 107 in the process of clockwise rotation.
Similarly, when the PCB board is rotated counter-clockwise by an external force, it is restricted to rotate only within the range of the arc mouth 115 so as to ensure that the conductive sheet 112 does not contact the film resistor 106 . The design of the position of the conductive sheet 111 and the conductive sheet 112 at each of the maxima of rotational movement should account for the fact that that the effective resistance value of the film resistor 106 is equal or close to that of the film resistor 107 .
The conductive sheet 110 , the conductive sheet 111 , and the conductive sheet 112 can also be film resistors, which overlap and are electrically connected, and so can be regarded as three resistors in parallel. Similarly, the resistance value of the film resistors can be changed and the same effect can be achieved. However, it is required that the conductive sheet 110 can only be used to electrically contact the film resistor 105 to change the resistance value thereof, and cannot directly contact other film resistors. It is required that the conductive sheet 111 can only be used to electrically contact the film resistor 106 to change the resistance value thereof, and cannot directly contact other film resistors. It is required that the conductive sheet 112 can only be used to electrically contact the film resistor 107 to change the resistance value thereof, and cannot directly contact other film resistors. This design can be realized by using multi-layered PCB board so as to keep the basic principle and structure of the microstrip variable attenuator.
With reference to FIG. 8 , the equivalent circuit diagram of the microstrip variable attenuator according to a second embodiment of the invention is equivalent to that of a continuous variable π-shaped attenuator being a symmetric wide band network with interchangeable input and output terminals.
FIG. 9 illustrates an ideal theoretical variation curve of the film resistor 105 , the film resistor 106 , and the film resistor 107 when the PCB board 113 is rotated clockwise by an external force. The variation trend of the resistance value of the film resistor 105 is opposite to those of the film resistor 106 and the film resistor 107 .
FIG. 10 illustrates a line showing the attenuation amount of the variable attenuator fabricated according to the curve of FIG. 9 when the PCB board 113 is rotated clockwise. During designing and fabricating, the film resistor 105 , the film resistor 106 , and the film resistor 107 are chosen according to the curve of FIG. 9 so as to realize variation in the attenuation amount, which is required when the displacement of the variable attenuator is changed.
The force to change the geometrical position of the conductive sheet 110 , the conductive sheet 111 , and the conductive sheet 112 can be a mechanical manual force, an automatic controlled mechanical force, an electromagnetic force, a force produced by heat or temperature, a force produced by the flow, expansion, or contraction of a liquid, or a force initiated by an optoelectronic excitation process.
The microstrip variable attenuator can be made into various package types, such as a surface mount type, a pin leg lead type, or a patch cord type.
The insulator and the conductive sheets of the present invention can be made of PCB board. The PCB board in the specified embodiments is a circle PCB board with an open arc mouth on its peripheral edge, and is concentric to the base for easy regulation. A block can be added on one end of the arc mouth to limit the rotation range of the PCB board so as to realize the optimal conformity, precise positioning, and precise regulation of the film resistors and the conductive sheets. Besides, an elastic film that is rigid in the rotation direction and is elastic in the vertical direction can be added between the PCB board 113 and the enclosure so as to keep the position of the PCB board after regulation and to stabilize the contact between the film resistor and the conductive sheet.
FIGS. 11-12 illustrate the structural diagram of the microstrip variable attenuator and the structural diagram of the conductive sheet in accordance with the third embodiment of the invention, respectively, comprising: a base 229 , an input terminal 216 and an output terminal 217 located on the base, an arc shaped strip film resistor 219 , an arc shaped strip film resistor 220 , an arc shaped strip film resistor 221 , a microstrip signal line 218 a , a microstrip signal line 218 , a ground terminal 222 for the connection of the microstrip signal lines. The microstrip variable attenuator further comprises a conductive sheet 223 , a conductive sheet 224 , and a conductive sheet 225 disposed on an insulator 227 .
A PCB board can also replace the insulator with conductive sheets disposed thereon. The PCB board can be in a circular shape for easy regulation. An arc mouth 228 is formed on the peripheral edge of the circle so as to limit the range of rotation regulation.
The base can be a ceramic base or a PCB board that is easy to process for microstrip resistors.
The input terminal 216 is connected to one end of the film resistor 219 via the microstrip signal line 218 a , the other end of the film resistor 219 is connected to one end of the film resistor 220 via the microstrip signal line 218 , and is connected to one end of the film resistor 221 , the other end of the film resistor 221 is connected to the ground terminal 222 ; the other end of the film resistor 220 is connected to the output terminal 217 via the microstrip signal line.
In certain embodiments of the invention, the film resistor 219 , the film resistor 220 , the film resistor 221 are all printed film resistors with the bottom side connected to the base 229 and the top side made of conductive and non-insulated material.
Particularly, the resistance value of the film resistor 219 is equal or close to that of the film resistor 220 .
The base can be multi-layered, the film resistors and the conductive sheets can be in the shape of a strip arc, rectangular, or other shape. Particularly, the shape of the conductive sheet is the same as or similar to that of the film resistor.
The resistance value, Zo, is generally designed to be equal at the input and output terminals, for example, about 50 Ohms. The PCB board 227 and the base 229 share the same center 226 . The PCB board 227 is installed on the base according to the position of the arc mouth 228 , the side fixed with conductive sheets of the PCB board meets the base; a conductive sheet 223 for contact short-circuiting, and having the same shape as the microstrip signal line 218 a , is located above the top side of the microstrip signal line 218 a , and is fixed on the PCB board 227 , which is further fixed with a conductive sheet 224 and a conductive sheet 225 .
The function of the conductive sheet 223 is to adjust the resistance value of the film resistor 219 . The function of the conductive sheet 224 is to adjust the resistance value of the film resistor 220 , while that of the conductive sheet 225 is to adjust the resistance value of the film resistor 221 . The conductive sheet 223 , the conductive sheet 224 , and the conductive sheet 225 rotate with the rotation of the PCB board 227 . For example, when the PCB board 227 is rotated clockwise by an external force, the conductive sheet 223 rotates in contact from the microstrip signal line toward the film resistor 219 , so that the contact area between the conductive sheet 223 and the film resistor 219 increases, and thus the resistance value of the film resistor 219 decreases. The conductive sheet 224 rotates in contact from the microstrip signal line toward the film resistor 220 , so that the contact area between the conductive sheet 224 and the film resistor 220 increases, and thus the resistance value of the film resistor 220 decreases. The conductive sheet 225 rotates in contact from the film resistor 221 towards the microstrip signal line so that the contact area between the conductive sheet 225 and the film resistor 221 decreases, and thus the resistance value of the film resistor 221 increases. Through the change in the geometric area, namely the change in the contact area between the conductive sheet and the film resistor, the actual effective resistance values of the film resistor 219 , the film resistor 220 , and the film resistor 221 can be changed.
An arc mouth 228 is formed on the peripheral edge of the PCB board 227 to limit the range of the rotation regulation. When the PCB board 227 rotates clockwise, it is preferred that the maximum rotation angle of the PCB board 227 be maintained so as to make the conductive sheet 223 nearly or totally short-circuit the film resistor 219 , and the length (arc length) of the conductive sheet 223 should cover or nearly cover the film resistor 219 . Moreover, the spacing between the film resistor 219 and the film resistor 220 should be taken into account so that the conductive sheet 223 does not contact the film resistor 220 in the process of clockwise rotation. Similarly, when the PCB board 227 is rotated counter-clockwise by an external force, it can only rotate within the range of the arc mouth 228 so as to ensure that the conductive sheet 224 does not contact the film resistor 219 .
The design of position of the conductive sheet 223 and the conductive sheet 224 at each of the maxima of the rotational movement, respectively, should account for the fact that the effective resistance value of the film resistor 219 is equal or close to that of the film resistor 220 .
The conductive sheets can also be film resistors, which overlap and are electrically connected, and so can be regarded as three resistors in parallel. Similarly, the resistance value of the film resistor can be changed and the same effect can be achieved. However, it is required that the conductive sheet 223 can only be used to electrically contact the film resistor 219 to change the resistance value thereof, and does not directly contact other film resistors. It is required that the conductive sheet 224 can only be used to electrically contact the film resistor 220 to change the resistance value thereof, and does not directly contact other film resistors. It is required that the conductive sheet 225 can only be used to electrically contact the film resistor 221 to change the resistance value thereof, and does not directly contact other film resistors. This design can be realized by using multi-layered PCB board so as to keep the basic principle and structure of the microstrip variable attenuator.
With reference to FIG. 13 , the equivalent circuit diagram of the microstrip variable attenuator according to the third embodiment of the invention is equivalent to that of a continuous variable T-shaped attenuator being a symmetric wide band network with interchangeable input and output terminals.
FIG. 14 illustrates an ideal theoretical variation curve of the film resistor 219 , the film resistor 220 , and the film resistor 221 when the PCB board 227 is rotated clockwise by an external force. The variation trend of the resistance value of the film resistor 219 and of the film resistor 220 is opposite to that of the film resistor 221 .
FIG. 15 illustrates a line showing the attenuation amount of the variable attenuator fabricated according to the curve of FIG. 14 when the PCB board 227 is rotated clockwise. During designing and fabricating, the film resistor 219 , the film resistor 220 , and the film resistor 221 are chosen according to the curve of FIG. 14 so as to realize variation in the attenuation amount, which is required when the displacement of the variable attenuator is changed.
The force to change the geometrical position of the conductive sheet 223 , the conductive sheet 224 , and the conductive sheet 225 is a mechanical manual force, an automatic controlled mechanical force, an electromagnetic force, a force produced by heat or temperature, a force produced by the flow, expansion, or contraction of a liquid, or a force initiated by an optoelectronic excitation process.
The microstrip variable attenuator can be made into various package types, such as a surface mount type, a pin leg lead type, or a patch cord type.
The insulator and the conductive sheets of the present invention can be made of PCB board. The PCB board in the specified embodiments is a circle PCB board with an open arc mouth on its peripheral edge, and is concentric to the base for easy regulation. A block can be added on one end of the arc mouth to limit the rotation range of the PCB board so as to realize the optimal conformity, precise positioning, and precise regulation of the film resistors and the conductive sheets. Besides, an elastic film that is rigid in the rotation direction and is elastic in the vertical direction can be added between the PCB board 227 and the enclosure so as to keep the position of the PCB board after regulation and to stabilize the contact between the film resistor and the conductive sheet.
This invention is not to be limited to the specific embodiments disclosed herein and modifications for various applications and other embodiments are intended to be included within the scope of the appended claims. While this invention has been described in connection with particular examples thereof, the true scope of the invention 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.
All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application mentioned in this specification was specifically and individually indicated to be incorporated by reference.
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The invention discloses a variable attenuator, comprising two or more resistors each resistor having its own effective resistance value, and means for simultaneously short circuiting at least a portion of two or more of said resistors, whereby simultaneously changing the effective resistance values. The variable attenuator of the invention is suitable for use in various high frequency and microwave circuits and systems, and has the features of a wide frequency band, small size, easy fabrication, low cost, and so on.
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BACKGROUND OF THE INVENTION
[0001] AAV vectors offer unique advantages over other vector systems in gene therapy applications. Studies have shown that these replication deficient parvovirus vectors can deliver DNA to specific tissues and confer long-term transgene expression in a variety of systems. Although many studies have looked at the tissue-specific expression elicited by each of the AAV serotypes, a true understanding of how AAV transduces these tissues is still unclear. Of the large AAV family, only a few receptors or co-receptors have been identified for any of the parvoviruses. The ability to better target transduction to specific tissues on the basis of the receptors that each serotype uses for entry, is essential to enable users to pick a serotype given the receptor expression in specific tissue, or to exploit altered receptor expression under disease conditions.
[0002] AAV6 has been reported to effectively transduce muscle, lung, brain, and multiple types of tumors, including gliomas and lung adenocarcinomas, and to elicit lower serum-neutralizing antibody concentrations when compared with AAV2. As such, there exists a need for improving the treatment of patients suffering from diseases such as cancer, which could be treated by AAV6 vector based gene therapy.
BRIEF SUMMARY OF THE INVENTION
[0003] In accordance with the present invention, it was found that the epidermal growth factor receptor (EGFR) is a co-receptor for AAV6 infection in mammalian cells, and is necessary for efficient vector internalization.
[0004] In an embodiment, the invention provides a method for introducing a heterologous nucleic acid into a host cell expressing EGFR comprising providing a pharmaceutical composition comprising a recombinant adeno-associated virus (AAV) vector comprising the AAV subtype 6 (AAV6) viral genome, or a functional portion thereof, and containing a heterologous nucleic acid sequence capable of being expressed by the host cell, under conditions which allow transduction of the host cell; and transducing the host cell with the recombinant AAV6 vector.
[0005] In a further embodiment, the host cell is a mammalian cell. In addition, in another embodiment, the host cell is a cancer cell. In yet another embodiment, the cancer cell is derived from a tumor of the head or neck.
[0006] In an embodiment of the present invention, the heterologous nucleic acid sequence can be either DNA or RNA, and can encode for a polypeptide.
[0007] In a further embodiment of the present invention, the heterologous nucleic acid encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent. For example, in an embodiment, the heterologous nucleic acid can encode an enzyme that when expressed in the cell in the presence of an agent or prodrug, causes modification of the agent into a cytotoxin, which then kills the host cell.
[0008] In another embodiment, the method includes a period of time between the administration of a therapeutically effective amount of a pharmaceutical composition comprising a recombinant AAV6 vector which encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent, and the administration of a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent. In an embodiment, the method of the present invention includes administration of one or more additional chemotherapeutic agents either concurrently with, or, after administration of the pharmaceutical composition comprising a recombinant AAV6 vector and the administration of a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0009] FIG. 1 is a pie chart illustrating that of the top 1000 genes returned by the program COMPARE, 760 genes were associated with identifiable gene names, of which 226 genes had established pathway interactions. Of these genes with known pathway interactions, 169 (75%) were found to be involved in EGFR signaling, with 21 (9%) having a direct interaction with, or regulation of, the EGF receptor (ERBB1).
[0010] FIG. 2 is a graph showing the quantification of FACS analysis of 32D-EGFR cells 96 hours after transduction with AAV2, AAV5, AAV1 or AAV6-CMV-EGFP. ***P<0.0001, n=3.
[0011] FIG. 3 shows two graphs that depict HEK293T and HN13 cells that were transfected with EGFR and siRNA against EGFR. Expression levels were quantified by western blotting, and the results are expressed as the percentage which are positive for GFP relative to controls. Cells were transduced by AAV2 or AAV6-CMV-eGFP (***P<0.0001, n=3).
[0012] FIG. 4 is a FACS analysis of HEK293T cells preincubated with one of the EGFR-specific inhibitors, AG1478 (Tyrphostin) or gefitinib (Iressa®, 4-(3-Chloro-4-fluorophenylamine)-7-methoxy-6(3-(4-morpholinyl)quinazoline), and subsequently incubated with AAV6-CMV-eGFP, to evaluate the impact of EGFR function on AAV6 mediated transduction. AAV2 transduction was not significantly influenced by EGFR inhibition. ***P<0.0001, n=3.
[0013] FIG. 5A is a graph showing internalization of AAV6 in 32D-EGFR cells. Internalization was measured in the presence or absence of gefitinib to evaluate the impact of function EGFR on AAV6 internalization. *P<0.01, n=3.
[0014] FIG. 5B is a graph depicting immunoprecipitation of AAV after incubating AAV2, AAV5, or AAV6 with protein A-sepharose beads alone, or with beads precoated with rhEGFR-Fc, or rhFGFR-Fc. ***P<0.0001, n=3.
[0015] FIG. 6 shows that AAV6 transduces tumor cells with functional EGFR expression. In vitro transduction of HEp-2 and HN12 cells with AAV2 and AAV6 in the presence or absence of the EGFR inhibitor, AG1478, was studied. A statistically significant increase in AAV6-mediated transduction was found in HN12 cells compared to HEp-2 cells (**p<0.001, n=3). Transduction of HN12 cells in the presence of AG1478 was reduced by 77% (***p<0.0005, n=3). An increase in AAV2-mediated transduction in HEp-2 cells compared to HN12 cells was noted (**p<0.001, n=3). There was no significant (NS) difference in AAV2-mediated transduction of HEp-2 or HN12 cells in the presence or absence of AG1478.
[0016] FIG. 7 depicts photographs showing evidence of AAV6 mediated transduction of EGFR expressing tumors and delivery of the cytotoxic transgene, HSVtk, followed by ganciclovir treatment, results in a significant reduction in tumor growth. Head and neck tumor cell lines, HN12 and HEp-2, were injected subcutaneously into the right and left flank of female nude mice. After tumors were established, AAV6-CMV-luciferase was introduced by direct intratumoral injection to the right flank tumors, with the vehicle control injected into the left flank tumors. Ten days after AAV administration, in vivo luciferase activity was measured by bioluminescence after intraperitoneal injection of luciferin (representative images, n=5).
[0017] FIG. 8 shows that AAV6 is able to deliver transgene to HNSCC xenograft tumors with high expression of EGFR. To further verify AAV-mediated transduction of the HNSCC tumors in the xenograft model, HN12 and HEp-2 tumor tissue was isolated and presence of transgene was quantified. Total DNA was isolated from tumors that received AAV6-CMVLuciferase (AAV6-CMV-Luc), or vehicle control, and the number of copies of vector genome/mg tissue were quantified by QPCR. HN12 tumors injected with AAV6-CMV-luciferase contained 4.6×10 4 ±0.1×10 4 copied vector genome/mg tissue. In contrast, AAV6-CMV-luciferase vector in HEp-2 cells was at background. ***p<0.0001, n=3.
[0018] FIG. 9 is a graph depicting the percentage growth of HN12 tumors injected with AAV6-CMV-HSVtk, followed by ganciclovir (GCV) treatment, and HN12 tumors treated with GCV alone. The HN12 xenograft tumors received intratumoral injections of AAV6-CMV-HSVtk. One week after AAV6 transduction, mice were started on daily GCV injections. Arrow indicates day GCV treatment was started. *P<0.05, **P<0.001, n=9.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In accordance with the present invention, it was found that the epidermal growth factor receptor (EGFR) is a co-receptor for AAV6 infection in mammalian cells, and is necessary for efficient vector internalization.
[0020] In an embodiment, the invention provides a method for introducing a heterologous nucleic acid into a host cell expressing EGFR comprising providing a pharmaceutical composition comprising a recombinant adeno-associated virus (AAV) vector comprising the AAV subtype 6 (AAV6) viral genome, or a functional portion thereof, and containing a heterologous nucleic acid sequence capable of being expressed by the host cell, under conditions which allow transduction of the host cell; and transducing the host cell with the recombinant AAV6 vector.
[0021] In an embodiment of the present invention, the transduction of the host cell can be either in vivo or in vitro.
[0022] In a further embodiment, the host cell is a mammalian cell. In addition, in another embodiment, the host cell is a cancer cell. In yet another embodiment, the cancer cell is derived from a tumor of the head or neck.
[0023] In an embodiment of the present invention, the heterologous nucleic acid sequence can be either DNA or RNA, and can encode for a polypeptide.
[0024] In another embodiment, the heterologous nucleic acid encodes proteins or polypeptides that replace missing or defective proteins required by the cell or subject into which the vector is transferred, or encodes a gene for a missing or defective protein, or can encode a cytotoxic polypeptide that can be directed, e.g., to cancer cells or other cells whose death would be beneficial to the subject.
[0025] In a further embodiment of the present invention, the heterologous nucleic acid encodes a polypeptide or protein that increases the host cell's susceptibility to a prodrug or cytotoxic agent, or encodes for a gene for said polypeptide or protein. For example, in an embodiment, the heterologous nucleic acid can encode a gene for an enzyme that when expressed in the cell in the presence of an agent or prodrug, causes modification of the agent into a cytotoxin, which then kills the host cell. For example, in an embodiment, the heterologous nucleic acid can encode at least one of the following enzymes selected from the group consisting of: E. coli nitroreductase, cytosine deaminase, Varicella Zoster-tk, Cytochrome P450 B1 (CYP2B1), carboxypeptidase G2 (CPG2) and E. coli purine nucleoside phosphorylase (ePNP), and the cells are then exposed to an agent or prodrug selected from the group consisting of: CB1954 (5-[aziridin-1-yl]-2,4-dinitrobenzamide), 5-FC (5-Fluorocytosine), araM (6-methoxy purine arabinoside), CPA (cyclophosphamide), benzoic acid mustard glutamates, and 6-methylpurine 2′-deoxyriboside (MePdR) respectively. In another embodiment, the heterologous nucleic acid encodes Herpes Simplex Virus thymidine kinase enzyme (HSV-tk), and the agent is an antiviral agent in the class of nucleotide analogs, such as acyclovir or ganciclovir.
[0026] In yet another embodiment of the present invention, the heterologous nucleic acid can also encode EGFR.
[0027] In an embodiment, the method includes a period of time between the administration of a therapeutically effective amount of a pharmaceutical composition comprising a recombinant AAV6 vector which encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent, and the administration of a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent. In another embodiment, the method of the present invention includes administration of one or more additional chemotherapeutic agents either concurrently with, or, after administration of the pharmaceutical composition comprising a recombinant AAV6 vector and the administration of a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent.
[0028] By “nucleic acid” as used herein includes “polynucleotide,” “oligonucleotide,” and “nucleic acid molecule,” and generally means a polymer of DNA or RNA, which can be single-stranded or double-stranded, synthesized or obtained (e.g., isolated and/or purified) from natural sources, which can contain natural, non-natural or altered nucleotides, and which can contain a natural, non-natural or altered internucleotide linkage, such as a phosphoroamidate linkage or a phosphorothioate linkage, instead of the phosphodiester found between the nucleotides of an unmodified oligonucleotide. It is generally preferred that the nucleic acid does not comprise any insertions, deletions, inversions, and/or substitutions. However, it may be suitable in some instances, as discussed herein, for the nucleic acid to comprise one or more insertions, deletions, inversions, and/or substitutions.
[0029] In an embodiment, the nucleic acids of the invention are recombinant. As used herein, the term “recombinant” refers to (i) molecules that are constructed outside living cells by joining natural or synthetic nucleic acid segments to nucleic acid molecules that can replicate in a living cell, or (ii) molecules that result from the replication of those described in (i) above. For purposes herein, the replication can be in vitro replication or in vivo replication.
[0030] The nucleic acids can be constructed based on chemical synthesis and/or enzymatic ligation reactions using procedures known in the art. See, for example, Sambrook et al. (eds.), Molecular Cloning, A Laboratory Manual, 3 rd Edition, Cold Spring Harbor Laboratory Press, New York (2001) and Ausubel et al., Current Protocols in Molecular Biology , Greene Publishing Associates and John Wiley & Sons, NY (2007). For example, a nucleic acid can be chemically synthesized using naturally occurring nucleotides or variously modified nucleotides designed to increase the biological stability of the molecules or to increase the physical stability of the duplex formed upon hybridization (e.g., phosphorothioate derivatives and acridine substituted nucleotides). Examples of modified nucleotides that can be used to generate the nucleic acids include, but are not limited to, 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil, hypoxanthine, xanthine, 4-acetylcytosine, 5-(carboxyhydroxymethyl) uracil, 5-carboxymethylaminomethyl-2-thiouridine, 5-carboxymethylaminomethyluracil, dihydrouracil, beta-D-galactosylqueosine, inosine, N 6 -isopentenyladenine, 1-methylguanine, 1-methylinosine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-methylcytosine, N 6 -substituted adenine, 7-methylguanine, 5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D-mannosylqueosine, 5′-methoxycarboxymethyluracil, 5-methoxyuracil, 2-methylthio-N 6 -isopentenyladenine, uracil-5-oxyacetic acid (v), wybutoxosine, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil-5-oxyacetic acid methylester, 3-(3-amino-3-N 2 -carboxypropyl) uracil, and 2,6-diaminopurine. Alternatively, one or more of the nucleic acids of the invention can be purchased from companies, such as Macromolecular Resources (Fort Collins, Colo.) and Synthegen (Houston, Tex.).
[0031] The nucleic acid can comprise a recombinant adeno-associated virus (AAV) vector comprising the AAV subtype 6 (AAV6) viral genome, and containing a heterologous nucleic acid sequence capable of being expressed by the host cell.
[0032] The nucleic acids of the invention can be incorporated into a recombinant expression vector. In this regard, the invention provides recombinant expression vectors comprising any of the nucleic acids of the invention. For purposes herein, the term “recombinant expression vector” means a genetically-modified oligonucleotide or polynucleotide construct that permits the expression of an mRNA, protein, polypeptide, or peptide by a host cell, when the construct comprises a nucleotide sequence encoding the mRNA, protein, polypeptide, or peptide, and the vector is contacted with the cell under conditions sufficient to have the mRNA, protein, polypeptide, or peptide expressed within the cell. The vectors of the invention are not naturally-occurring as a whole. However, parts of the vectors can be naturally-occurring. The inventive recombinant expression vectors can comprise any type of nucleotides, including, but not limited to DNA and RNA, which can be single-stranded or double-stranded, synthesized or obtained in part from natural sources, and which can contain natural, non-natural or altered nucleotides. The recombinant expression vectors can comprise naturally-occurring, non-naturally-occurring internucleotide linkages, or both types of linkages. Preferably, the non-naturally occurring or altered nucleotides or internucleotide linkages do not hinder the transcription or replication of the vector.
[0033] The recombinant expression vectors of the invention can be prepared using standard recombinant DNA techniques described in, for example, Sambrook et al., supra, and Ausubel et al., supra. Constructs of expression vectors, which are circular or linear, can be prepared to contain a replication system functional in a prokaryotic or eukaryotic host cell. Replication systems can be derived, e.g., from ColE1, 2μ plasmid, SV40, bovine papilloma virus, and the like.
[0034] Desirably, the recombinant expression vector comprises regulatory sequences, such as transcription and translation initiation and termination codons, which are specific to the type of host (e.g., bacterium, fungus, plant, or animal) into which the vector is to be introduced, as appropriate and taking into consideration whether the vector is DNA or RNA based.
[0035] The recombinant expression vector can include one or more marker genes, which allow for selection of transformed or transfected hosts. Marker genes include biocide resistance, e.g., resistance to antibiotics, heavy metals, etc., complementation in an auxotrophic host to provide prototrophy, and the like. Suitable marker genes for the inventive expression vectors include, for instance, LacZ, green fluorescent protein (GFP), luciferase, neomycin/G418 resistance genes, hygromycin resistance genes, histidinol resistance genes, tetracycline resistance genes, and ampicillin resistance genes.
[0036] The term “heterologous nucleic acid sequence” means one or more nucleic acid sequences encoding polypeptides for one or more proteins or enzymes which are not native to AAV6, and which are capable of being expressed when transduced in a host cell, or sequences encoding genes for said one or more proteins or enzymes. In an embodiment of the present invention, the heterologous nucleic acid sequence encodes a gene for an enzyme that is expressed within the host cell, and wherein the enzyme's activity within the host cell, increases the host cell's susceptibility to a particular prodrug or cytotoxic agent. This type of enzyme is also called a “suicide gene.” See, for example, Suicide Gene Therapy: Methods and Reviews , Springer, Caroline J. (Cancer Research UK Centre for Cancer Therapeutics at the Institute of Cancer Research, Sutton, Surrey, UK), Humana Press, 2004). Examples of combinations of enzyme and prodrug that are capable of being used in the present invention include, for example, HSV-tk and ganciclovir, E. coli nitroreductase and CB1954 (5-[aziridin-1-yl]-2,4-dinitrobenzamide), cytosine deaminase and 5-FC (5-Fluorocytosine), Varicella Zoster-tk and araM (6-methoxy purine arabinoside), Cytochrome P450 B1 (CYP2B 1) and CPA (cyclophosphamide), carboxypeptidase G2 (CPG2) and benzoic acid mustard glutamates, E. coli purine nucleoside phosphorylase (ePNP) and 6-methylpurine deoxyriboside (MePdR).
[0037] The heterologous nucleic acid can be a nucleic acid not normally found in the target cell, or it can be an extra copy or copies of a nucleic acid normally found in the target cell. The terms “exogenous” and “heterologous” are used herein interchangeably.
[0038] By “functionally linked” is meant that the promoter can promote expression of the heterologous nucleic acid, as is known in the art, and can include the appropriate orientation of the promoter relative to the exogenous nucleic acid. Furthermore, the heterologous nucleic acid preferably has all appropriate sequences for expression of the nucleic acid. The nucleic acid can include, for example, expression control sequences, such as an enhancer, and necessary information processing sites, such as ribosome binding sites, RNA splice sites, polyadenylation sites, and transcriptional terminator sequences.
[0039] The heterologous nucleic acid can encode beneficial proteins or polypeptides (e.g., “beneficial” proteins or polypeptides) that replace missing or defective proteins required by the cell or subject into which the vector is transferred, or can encode a cytotoxic polypeptide that can be directed, e.g., to cancer cells or other cells whose death would be beneficial to the subject. The heterologous nucleic acid can also encode antisense RNAs that can bind to, and thereby inactivate, mRNAs made by the subject that encode harmful proteins. The heterologous nucleic acid can also encode ribozymes that can effect the sequence-specific inhibition of gene expression by the cleavage of mRNAs. In one aspect, antisense polynucleotides can be produced from an heterologous expression cassette in an AAV6 vector construct where the expression cassette contains a sequence that promotes cell-type specific expression (Wirak et al., EMBO 10:289 (1991)). For general methods relating to antisense polynucleotides, see Antisense RNA and DNA , D. A. Melton, Ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1988). Other examples of heterologous nucleic acids which can be administered to a cell or subject as part of the recombinant AAV6 vector of the present invention can include, but are not limited to, the following: nucleic acids encoding secretory and nonsecretory proteins, nucleic acids encoding therapeutic agents.
[0040] In addition, other therapeutic agents may be encoded by heterologous nucleic acids, such as tumor necrosis factors (TNFs), as TNF-α; interferons, such as interferon-α, interferon-β, and interferon-γ, interleukins, such as IL-1, IL-1β, and ILs-2 through -14; GM-CSF; adenosine deaminase; cellular growth factors, such as lymphokines; soluble CD4; Factor VIII; Factor IX; T-cell receptors; LDL receptor; ApoE; ApoC; alpha-1 antitrypsin; ornithine transcarbamylase (OTC); cystic fibrosis transmembrane receptor (CFTR); insulin; Fc receptors for antigen binding domains of antibodies, such as immunoglobulins; anti-HIV decoy tar elements; and antisense sequences which inhibit viral replication, such as antisense sequences which inhibit replication of hepatitis B or hepatitis non-A, non-B virus. The nucleic acid is chosen considering several factors, including the cell to be transfected. Where the target cell is a blood cell, for example, particularly useful nucleic acids to use are those which allow the blood cells to exert a therapeutic effect, such as a gene encoding a clotting factor for use in treatment of hemophilia. Another target cell is the lung airway cell, which can be used to administer nucleic acids, such as those coding for the cystic fibrosis transmembrane receptor, which could provide a gene therapeutic treatment for cystic fibrosis. Other target cells include muscle cells where useful nucleic acids, such as those encoding cytokines and growth factors, can be transduced and the protein the nucleic acid encodes can be expressed and secreted to exert its effects on other cells, tissues and organs, such as the liver. In addition, cancer cells corresponding or derived from lung, muscle, brain and other tissues can be target tissues. Furthermore, the nucleic acid can encode more than one gene product, limited only, if the nucleic acid is to be packaged in a capsid, by the size of nucleic acid that can be packaged.
[0041] The provided viral particles can be administered to cells, as described herein, with a Multiplicity of Infection (MOI) of 10. The MOI is the ratio of infectious virus particles to the number of cells being infected. Thus, an MOI of 0.1 results in the average inoculation of 1 virus particle for every 10 cells. The general theory behind MOI is to introduce one infectious virus particle to every host cell that is present in the culture. However, more than one virus may infect the same cell which leaves a percentage of cells uninfected. This occurrence can be reduced by using a higher MOI to ensure that every cell is infected. The provided viral particles can therefore be administered to cells, as described herein, with a MOI of 0.01 to 100, such as for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40, 50, 60, 70, 80, 90, 100.
[0042] The recombinant AAV vector is produced by recombinant methods utilizing multiple plasmids. In one example, the AAV1, AAV2, AAV5 or AAV6 recombinant viruses are produced using a three plasmid procedure previously described (Alisky et al., Neuroreport, 11: 2669-2673 (2000)). Briefly, semiconfluent HEK293T cells are transfected by calcium phosphate with three plasmids: an Ad helper plasmid containing the VA RNA, E2, and E4; an AAV helper plasmid containing the Rep and Cap genes for the serotype that is to be packaged; and a vector plasmid containing the inverted terminal repeats (ITRs) corresponding to the serotypes flanking a reporter gene of interest. Forty-eight hours posttransduction, the cells are harvested by scraping in TD buffer (140 mM NaCl, 5 mM KCl, 0.7 mM K2HPO4, 25 mM Tris-HCl pH 7.4) and the cell pellet concentrated by low-speed centrifugation. The cells that are efficiently transduced by all three plasmids, exhibit specific integration as well as the ability to produce the particular AAV recombinant virus of the present invention.
[0043] As defined herein, a functional portion or functional variant of the AAV6 vector, includes, for example, nucleotide sequences encoding any of the VA RNA, E2, E4, Rep, and Cap proteins, and fragments thereof.
[0044] The recombinant expression vector of the present invention comprises a native or normative promoter operably linked to the nucleotide sequence encoding a recombinant AAV6 viral genome and contains a heterologous nucleic acid sequence capable of being expressed by the host cell, or to the nucleotide sequence which is complementary to or which hybridizes to the nucleotide sequence encoding a recombinant AAV6 viral genome and containing a heterologous nucleic acid sequence capable of being expressed by the host cell, discussed above.
[0045] The selection of promoters, e.g., strong, weak, inducible, tissue-specific and developmental-specific, is within the ordinary skill of the artisan. Similarly, the combining of a nucleotide sequence with a promoter is also within the skill of the artisan. The promoter can be a non-viral promoter or a viral promoter, e.g., a cytomegalovirus (CMV) promoter, an SV40 promoter, an RSV promoter, and a promoter found in the long-terminal repeat of the murine stem cell virus.
[0046] The invention further provides a host cell comprising any of the recombinant expression vectors described herein. As used herein, the term “host cell” refers to any type of cell that can contain the inventive recombinant expression vector. The host cell can be an animal cell. Preferably, in an embodiment, the host cell is a mammalian cell. The host cell can be a cultured cell or a primary cell, i.e., isolated directly from an organism, e.g., a human. The host cell can be an adherent cell or a suspended cell, i.e., a cell that grows in suspension. Most preferably, the host cell is a human cell. The host cell can be of any cell type, can originate from any type of tissue, and can be of any developmental stage. Most preferably the host cells can include, for instance, muscle, lung, and brain cells, and the like.
[0047] The host referred to in the inventive methods can be any host. Preferably, the host is a mammal. As used herein, the term “mammal” refers to any mammal, including, but not limited to, mammals of the order Rodentia, such as mice and hamsters, and mammals of the order Logomorpha, such as rabbits. It is preferred that the mammals are from the order Carnivora, including Felines (cats) and Canines (dogs). It is more preferred that the mammals are from the order Artiodactyla, including Bovines (cows) and Swines (pigs) or of the order Perssodactyla, including Equines (horses). It is most preferred that the mammals are of the order Primates, Ceboids, or Simoids (monkeys) or of the order Anthropoids (humans and apes). An especially preferred mammal is the human.
[0048] In addition, the host cell can be a cancer cell. For example, in an embodiment, the host cell of the present can be a tumor cell, such as a tumor derived from the head or neck of a mammal, or a cell line derived from the head or neck of a mammal. With respect to the inventive methods, the cancer can be any cancer which expresses EGFR, including any of acute lymphocytic cancer, acute myeloid leukemia, alveolar rhabdomyosarcoma, bone cancer, brain cancer, breast cancer, cancer of the anus, anal canal, or anorectum, cancer of the eye, cancer of the intrahepatic bile duct, cancer of the joints, cancer of the neck, gallbladder, or pleura, cancer of the nose, nasal cavity, or middle ear, cancer of the oral cavity, cancer of the vulva, chronic lymphocytic leukemia, chronic myeloid cancer, colon cancer, esophageal cancer, cervical cancer, gastrointestinal carcinoid tumor. Hodgkin lymphoma, hypopharynx cancer, kidney cancer, larynx cancer, liver cancer, lung cancer, malignant mesothelioma, melanoma, multiple myeloma, nasopharynx cancer, non-Hodgkin lymphoma, ovarian cancer, pancreatic cancer, peritoneum, omentum, and mesentery cancer, pharynx cancer, prostate cancer, rectal cancer, renal cancer (e.g., renal cell carcinoma (RCC)), small intestine cancer, soft tissue cancer, stomach cancer, testicular cancer, thyroid cancer, ureter cancer, and urinary bladder cancer. Preferably, the cancer is head or neck cancer.
[0049] Also provided by the invention is a population of cells comprising at least one host cell described herein. The population of cells can be a heterogeneous population comprising the host cell comprising any of the recombinant expression vectors described, in addition to at least one other cell, e.g., a host cell (e.g., a lung cell), which does not comprise any of the recombinant expression vectors, or a cell other than a lung cell, e.g., a skin cell, a neutrophil, an erythrocyte, a hepatocyte, an endothelial cell, an epithelial cell, a muscle cell, a brain cell, etc. Alternatively, the population of cells can be a substantially homogeneous population, in which the population comprises mainly of host cells (e.g., consisting essentially of) comprising the recombinant expression vector. The population also can be a clonal population of cells, in which all cells of the population are clones of a single host cell comprising a recombinant expression vector, such that all cells of the population comprise the recombinant expression vector. In one embodiment of the invention, the population of cells is a clonal population comprising host cells comprising a recombinant expression vector as described herein.
[0050] The recombinant vectors comprising the AAV6 viral genome and containing a heterologous nucleic acids sequence capable of being expressed by the host cell to be used for in vivo administration must be sterile. This is readily accomplished by, for example, filtration through sterile filtration membranes, prior to, or following reconstitution.
[0051] Therapeutic compositions generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by a hypodermic injection needle. The route of administration of the recombinant AAV vectors, in accordance with the present invention, is in accord with known methods, e.g., injection or infusion by intravenous, intraperitoneal, intramuscular, intrarterial, subcutaneous, intralesional routes, by aerosol or intranasal routes, or by sustained release systems as noted below. The recombinant AAV vectors, are administered continuously by infusion or by bolus injection.
[0052] An effective amount of recombinant AAV vector to be employed therapeutically will depend, for example, upon the therapeutic and treatment objectives, the route of administration, the age, condition, and body mass of the patient undergoing treatment or therapy, and auxiliary or adjuvant therapies being provided to the patient. Accordingly, it will be necessary and routine for the practitioner to titer the dosage and modify the route of administration, as required, to obtain the optimal therapeutic effect. A typical daily dosage might range from about 1×10 4 genomic particles/dose to about 1×10 9 genomic particles/dose or more, preferably from about 1×10 6 to about 1×10 8 genomic particles/dose, depending on the above-mentioned factors. Typically, the clinician will administer antibody until a dosage is reached that achieves the desired effect. The progress of this therapy is easily monitored by conventional assays.
[0053] The recombinant adeno-associated virus (AAV) vectors used in the context of the present invention can, themselves, be linked to a detectable label. Such a detectable label allows for the presence of, or the amount of the viral titer to be determined.
[0054] Alternative methods of vector delivery such as convection may enhance AAV6 distribution and, thus, more widespread tumor killing than the simple intratumoral injection. For example, an alternative method for efficient and widespread delivery of macromolecules and particles to tumors is convection-enhanced infusion, which is used to supplement simple diffusion and to improve vector distribution by bulk flow inside and outside the tumor. Stereotactic injection and subsequent infusion by maintaining a positive pressure gradient is able to improve the distribution of large molecules in animal models (Lieberman D. M., et al., J. Neurosurg. 82: 1021-1029 (1985)). In an embodiment, the present invention provides a method of treating a tumor which expresses EGFR in a mammal comprising administering to the mammal via convection-enhanced infusion, a therapeutically effective amount of a pharmaceutical composition comprising a recombinant AAV6 vector which encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent, and administering to the mammal a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent.
[0055] When applied, for example, to rat brain tumors, this convection-enhanced infusion technique was able to mediate delivery of virus particles to tumors with an approximate volume of 100 mm 3 , and also beyond the tumor borders into the surrounding brain tissue (Nilayer et al., Proc. Natl. Acad. Sci. USA 92: 9829-9833 (1995)).
[0056] Other methods of vector application include, for example, intravascular methods. Intravascular methods of vector application make use of a natural and ubiquitously distributed network of arteries, veins and capillaries, which is present in every normal tissue and is even denser in malignant tumors. Intravascular applications, such as intra-arterial injection of virus vectors, are capable of delivering a vector to the largest proportion of tumor cells and surrounding tissues without afflicting mechanical injury to normal brain tissue or having other toxic consequences (Spear et al., J. Neurovirol. 4: 133-147 (1998); Muldoon et al., “Delivery of therapeutic genes to brain and intracerebral tumors; in Chiocca E. A., and Breakefield X. O. (eds.), “Gene Therapy for Neurological Disorders and Brain Tumors,” Boston: Humana Press, pp 128-139 (1997)). In an embodiment, the present invention provides a method of treating a tumor which expresses EGFR in a mammal, comprising administering to the mammal, via intravascular methods of vector application, a therapeutically effective amount of a pharmaceutical composition comprising a recombinant AAV6 vector which encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent, and administering to the mammal a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent.
[0057] Alternatively, in an embodiment, the present invention provides a method of treating a tumor which expresses EGFR in a mammal comprising administering to the mammal via intravascular methods of vector application, a therapeutically effective amount of a pharmaceutical composition comprising a recombinant AAV6 vector which encodes a gene that increases the host cell's susceptibility to a prodrug or cytotoxic agent, and administering to the mammal a therapeutically effective amount of a pharmaceutical composition comprising the specific prodrug or cytotoxic agent, in combination with one or more other pharmaceutically active agents or drugs, such as a chemotherapeutic agents, e.g., asparaginase, busulfan, carboplatin, cisplatin, daunorubicin, doxorubicin, fluorouracil, gemcitabine, hydroxyurea, methotrexate, paclitaxel, rituximab, vinblastine, vincristine, etc.
[0058] The terms “treat,” and “prevent” as well as words stemming therefrom, as used herein, do not necessarily imply 100% or complete treatment or prevention. Rather, there are varying degrees of treatment or prevention of which one of ordinary skill in the art recognizes as having a potential benefit or therapeutic effect. In this respect, the inventive methods can provide any amount of any level of treatment or prevention of a disease in a mammal. Furthermore, the treatment or prevention provided by the inventive method can include treatment or prevention of one or more conditions or symptoms of the disease being treated or prevented. Also, for purposes herein, “prevention” can encompass delaying the onset of the disease, or a symptom or condition thereof.
[0059] The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.
EXAMPLES
[0060] Cell Cultures, rAAV production and transduction. The NCI60 cell line panel, and mouse IL-3-dependent myeloid cell line 32D, were maintained under standard culture conditions and cultured in RPMI media, 10% heat-inactivated fetal bovine serum (FBS), and 100 U/ml penicillin/streptomycin/amphotercin B (Invitrogen, Carlsbad Calif.). The 32D cells were further supplemented with 10 μg/ml IL-3 (Sigma, St. Louis Mo.). 32D cells were transfected with lipofectamine 2000 (Invitrogen) to deliver EGFR (ERBB1), ERBB2, ERBB3, or ERBB4 expression plasmids. Stably transfected 32D cells were selected for neomycin resistance, single cell populations were expanded and validated for specific isoform expression by western blot analysis. HN12, HN13 and HEp-2 cells were maintained under standard culture conditions and cultured in DMEM media, 10% heat-inactivated FBS, 100 U/ml penicillin/streptomycin/amphotercin B (Invitrogen).
[0061] Recombinant AAV 1, AAV2, AAV5 and AAV6 were produced using a three plasmid expression system (See, Schmidt, M., et al., “Adeno-associated virus type 12 (AAV12): a novel AAV serotype with sialic acid- and heparan sulfate proteoglycan-independent transduction activity,” J. Virol. 82: 1399-1406 (2008)). AAV was produced carrying either the Rous sarcoma virus long terminal repeat promoter driving expression of the nuclear localized beta-galactosidase reporter gene (RSV-NLS-LacZ), or nuclear-localized enhanced green fluorescent protein (NLS-eGFP), luciferase, or the herpes simplex virus 1 thymidine kinase transgene (HSVtk), driven by the cytomegalovirus early-immediate promoter, the driving protein promoter (CMV) and flanked by AAV2 inverted terminal repeats (ITR). In developing the seed data for COMPARE, the NCI60 cell line panel was transduced over a serial dilution with AAV6-RSV-NLS-LacZ. Transduction efficiency was measured by staining for beta-galactosidase expression in the transduced cells 60 hours post-transduction.
[0062] Comparative Gene Analysis. AAV6 transduction efficiency was measured in 48 cell lines within the NCI60 cell panel. Cells were transduced with AAV6-RSV-NLSLacZ vector over a serial dilution, and the averaged transduction efficiency was used as seed data for COMPARE as previously described (Di Pasquale, G., et al. Identification of PDGFR as a receptor for AAV-5 transduction. Nat. Med., 9: 1306-1312 (2003)). The full AAV6 transduction profile data is available in the DTP database (http://dtp.nci.nih.gov/mtargets/mt_index.html) (See, Zaharevitz, D. W., Holbeck, S. L., Bowerman, C. & Svetlik, P. A., “COMPARE: a web accessible tool for investigating mechanisms of cell growth inhibition,” J. Mol. Graph. Model. 20: 297-303 (2002)). COMPARE is a publicly available web-based data-mining tool offered by the Developmental Therapeutics Program (DTP), at the National Cancer Institute (NCI) (http://dtp.nci.nih.gov/compare/). The cDNA microarray data for the NCI60 cell line panel was used to identify genes with an expression pattern that highly correlated with the AAV6 transduction profile. A second software program, Microarray Analysis Program Package (MAPP) (Wilson, P. A., Microarray Analysis Perl Program (2007)), was used to further detail potential genes of interest by identifying alternative gene descriptors, subcellular location, and function specific for the COMPARE output format. The MAPP detailed gene data was then input into two pathway analysis software packages, Pathway Architect (Stratagene, La Jolla Calif.) and ExPlain (Biobase International, Wolfenbattel, Germany), to visualize connectivity of genes that positively correlate with AAV6 transduction. The use of multiple pathway mapping software packages compensated for the variability in mapping algorithms and coverage of signal transduction pathway of each program.
[0063] AAV transduction and pharmacological inhibition. The 32D and 32D-EGFR cells were transduced with 1.0E4 genomic particle (gp)/cell with each of the AAV serotypes tested. Cells were analyzed for GFP expression by FACS analysis at 96 hours post-transduction. The HEK293T, HN12 and HEp-2 cells, shown to be permissive to AAV2 and/or AAV6, were used to evaluate the specific role of EGFR in AAV-mediated transduction. Cells were incubated at 37° C. in the presence or absence of AG1478 (10 μm) or gefitnib (10 μm) for 30 minutes prior to addition of AAV. AAV2 and AAV6 containing the CMV-NLS-eGFP construct were added at a concentration of 1.0×10 4 gp/ml for 90 minutes. Cells were gently washed to remove excess, non-bound virus, and GFP expression was analyzed by FACS 48 hours post transduction for HEK293T cells, or 96 hours post transduction for HN12 and HEp-2 cell lines.
[0064] siRNA knockdown of EGFR expression. siRNA against EGFR was used to knockdown EGFR expression in HEK293T and HN13 cells. The EGFR siRNA (Qiagen, Valencia Calif.; #S100074053) and the Allstars negative siRNA control (Qiagen, #1027280), were added to cells as per manufacturer's protocol. Cultures were incubated for 48 hours prior to transduction with AAV6 containing the CMV-NLS-eGFP construct at a concentration of 1.0E4 gp/cell. Cells were analyzed for transgene expression 48 hours post transduction by FACS analysis.
[0065] AAV Internalization. 32D-EGFR cells were incubated with either AAV2 or AAV6-CMV-NLS-eGFP in the presence or absence of 10 m AG1478 for 90 minutes at 37° C. Cells were gently washed to remove excess, non-bound virus and incubated with 0.5% trypsin to removed remaining extracellular virus. Intracellular DNA was isolated and copies of vector genome/cell population were quantified by QPCR as described previously (Di Pasquale, G., et al.).
[0066] Specific Co-precipitation of AAV6 and EGFR. The rhEGFR-Fc or rhFGFRFc chimeric soluble proteins (R&D Systems, Minneapolis, Minn.; 5 g protein) were coupled with a 10% solution of protein-A sepharose beads (Sigma) in PBS, containing 1% BSA and 0.1% pluronic acid, at 4° C. for 4 hours with gentle agitation. AAV was added (1.0×10 9 gp) to the soluble receptor-sepharose bead complex solution and incubated at 4° C. with gentle agitation for 90 minutes. Beads were centrifuged and extensively washed to remove excess, non-bound protein and AAV. Viral DNA was isolated and copies of vector genome were quantified by QPCR (Di Pasquale, G., et al.). As a measure of non-specific AAV binding, sepharose beads and AAV were incubated for similar durations and conditions, in the absence of rhEGFR-Fc, or rhFGFR-Fc.
[0067] Animal Studies. All animal studies were carried out according to NIH-approved protocols, in compliance with the Guide for the Care and Use of Laboratory Animals. Female athymic (nu/nu) nude mice (Harlan Sprague-Dawley), 5 to 6 weeks old and weighing 18 to 20 g, were used in the study, housed in appropriate sterile filter-capped cages, and fed and given water ad libitum. Head and neck tumor cell lines, HN12 and HEp-2 (2.0×10 6 cells/injection), were injected subcutaneously into both the right and left flank of nude mice to establish xenograft tumors. After tumors were established (7-10 days), AAV6-CMV-luciferase or AAV6-CMV-HSVtk (4.0×10 9 gp/40 ul) was injected intothe flank tumors. Luciferase transgene expression was measured 10 days post AAV6 treatment by intraparatoneal injection of luciferin (4 mg/100 ml in PBS). Bioluminescence was imaged using the IVIS Xenogen imaging system (Xenogen, Alemeda Calif.) to measure luciferase expression in vivo. Regions of interest were quantified as mean average radiance (photons/s/cm 2 /sr) using Living Image software tools (Xenogen). To quantify copies of vector genome/mg tumor tissue, DNA was isolated from 25-35 mg samples of tumor tissue and copies vector genome were quantified by QPCR17. Copies vector genome/mg tissue of HN12 or HEp-2 tumors that only received vehicle control was used a background control and subtracted from vector genome/mg tumor tissue calculated for tumors that received intratumoral AAV6-CMV-luciferase injections.
[0068] For the gene-directed enzyme prodrug therapy (GDEPT) study, tumors were injected with AAV6-CMV-HSVtk (4.0E9 genomic particles/40 μl) or equal volume of vehicle (0.9% saline). Ganciclovir (Sigma) (50 mg/kg/day) was delivered via intraparatoneal injections daily. Tumor volume was measured as previously described (See, Amornphimoltham, P., et al., “Mammalian target of rapamycin, a molecular target in squamous cell carcinomas of the head and neck,” Cancer Res. 65: 9953-9961 (2005)). Length (L) and width (W) of tumor were determined and volume was calculated using the following equation: (L*W2)/2. Percent tumor growth was calculated as tumor volume at each time point per volume prior to start of ganciclovir treatment. Tumors were measured until day 20 at which time the size of the untreated tumors required ethical termination of the study.
[0069] There was no significant difference in tumor volume noted between tumors that received AAV6 and those that did not prior to starting ganciclovir treatment (data not shown). Additionally, there was no significant difference in percent tumor growth of tumors that received AAV6-CVM-HSVtk and no ganciclovir treatment and those tumors that were not transduced by AAV6 but did receive ganciclovir treatment (data not shown).
[0070] Statistical Analysis. We analyzed the statistical significance of the linear relationship between AAV6 transduction and gene expression patterns using Pearson correlation coefficient (PCC) calculated through the COMPARE program, and verified statistical significance of EGFR (GC 16216) using correlation analysis with Prism software (Graphpad, La Jolla Calif.). All data is presented as means+/−s.e.m. Statistical significance was calculated using unpaired Student's t-test.
Example 1
[0071] This example discloses how CGA was used to identify correlations between viral transduction profiles and gene expression profiles across the NCI60 cell panel.
[0072] Building upon the established CGA method, additional bioinformatics-based software and pathway visualization packages were added, to further prioritize potential AAV cell surface receptors. The expression data and Pearson correlation coefficient (PCC) values were obtained from the Developmental Therapeautics Program online database and web-accessible COMPARE program. Of the top 1000 genes returned by COMPARE, 760 genes were associated with identifiable gene names, of which 226 genes had established pathway interactions. Of these genes with known pathway interactions, 169 (75%) were found to be involved in EGFR signaling with 21 (9%) having a direct interaction with or regulation of the EGF receptor (ERBB1) ( FIG. 1 ).
[0073] A positive correlation between EGFR expression (DTP microarray pattern identification number GC16212) and cells permissive to AAV6 (PCC value of 0.421, P=0.003) was identified. Our discovery of extensive clustering of positive PCC genes connected to the EGFR signaling pathway provided the basis for further studies on the involvement of EGFR or its downstream signaling pathways in AAV6 transduction.
Example 2
[0074] To confirm whether the in silico findings would translate to activity in vivo, the influence of EGFR expression on AAV6 transduction was studied.
[0075] Initially, 32D cells, an IL-3-dependent hematopoietic progenitor cell line, which lack EGFR expression to stably express EGFR (32D-EGFR), were transduced with multiple AAV serotypes. Wild-type 32D cells were not permissive for any of the serotypes tested. In the presence of EGFR, AAV6 was able to efficiently transduce about 54.1±0.3% of the 32D-EGFR cells ( FIG. 2 ). Like AAV6, AAV1 was able to transduce the 32D-EGFR cells, but to a lesser extent suggesting additional molecules may be necessary for optimal transduction activity with this vector. The lack of transduction by AAV2 or AAV5 in the presence or absence of EGFR suggests EGFR specificity for AAV6-like viruses.
Example 3
[0076] In this example, EGFR-specific siRNA was used to knock down EGFR expression, and evaluate the impact on AAV transduction in two cell lines, HEK293T cells and HN13 cells, human embryonic kidney and head-and-neck tumor cell lines, respectively. Expression levels were quantified by western blotting, and the results are expressed as the percentage which are positive for GFP relative to controls. Cells were transduced by AAV2 or AAV6-CMV-eGFP (***P<0.0001, n=3). In HEK293T and HN13 cells, EGFR expression was knocked down by 37% and 58%, respectively, with EGFR-specific siRNA and, in accordance, corresponded with a 40% and 70% decrease in transduction, respectively ( FIG. 3 ).
Example 4
[0077] To better understand the role of EGFR in AAV6 transduction, AAV6 vector transduction was measured in the presence or absence of the EGFR inhibitors AG1478 or gefitinib.
[0078] HEK293T cells were preincubated with one of the EGFR-specific inhibitors, AG1478 (Tyrphostin) or gefitinib (Iressa®, 4-(3-Chloro-4-fluorophenylamine)-7-methoxy-6(3-(4-morpholinyl)quinazoline), and subsequently incubated with AAV6-CMV-eGFP, to evaluate the impact of EGFR function on AAV6 mediated transduction. AAV2 transduction was not significantly influenced by EGFR inhibition. ***P<0.0001, n=3.AAV6 transduction of HEK293T cells was inhibited by 50% in the presence of either inhibitor. Under the same conditions, AAV2 transduction was unchanged ( FIG. 4 ).
Example 5
[0079] This example shows that EGFR is necessary for AAV6 internalization.
[0080] Internalization was measured in the presence or absence of gefitinib to evaluate the impact of function EGFR on AAV6 internalization. *P<0.01, n=3. Further analysis suggested that EGFR is involved in vector entry, as AAV internalization was decreased by over 500% in the presence of gefitinib ( FIG. 5A ). These results suggest that functional signaling through EGFR is required for AAV6 transduction and vector internalization.
Example 6
[0081] Although the above data suggest a direct interaction between EGFR and AAV6, EGFR could be functioning as a part of a complex, or AAV6 could be using the same trafficking pathway as EGFR.
[0082] To measure direct EGFR-AAV6 interaction, soluble recombinant human EGFR-Fc fusion protein (rhEGFR-Fc) or soluble FGFR (rhFGFR-Fc) was prebound to protein A-sepharose beads, and then they were incubated with AAV2, AAV5 or AAV6. Of the three serotypes used, AAV6 binding increased approximately sevenfold in the presence of rhEGFR-Fc ( FIG. 5B ). No significant increase in EGFRspecific binding with AAV2 or AAV5 was observed. Furthermore, AAV6 did not bind to rhFGFR-Fc-coated beads ( FIG. 5B ), suggesting a specific AAV6-EGFR interaction.
Example 7
[0083] Increased expression of EGFR correlates with aggressive head and neck squamous cell carcinoma (HNSCC) tumor growth and resistance to treatment (Thariat, J., et al., Int. J. Clin. Oncol., 12: 99-110 (2007)). The utility of AAV6 to transduce and ablate specific HNSCCs presenting with elevated EGFR expression was assessed by gene-directed enzyme prodrug therapy. Two HNSCC cell lines, HN12 and HEp-2 were selected to represent polarities of EGFR expression. HN12 cells express a higher level of membrane-localized EGFR compared with HEp-2 cells, which express a lower, more diffuse pattern of EGFR expression (Magné, N., et al., Br. J. Cancer, 86: 1518-1523 (2002). In preliminary in vitro studies, HN12 cells showed an EGFR-dependent AAV6 transduction, whereas HEp-2 cells were markedly less permissive to AAV6. Transduction of HEp-2 cells was not altered in the presence of AG1478 ( FIG. 6 ).
Example 8
[0084] In this example, in order to evaluate the AAV6-EGFR interaction in vivo, xenograft tumor models of these two cell lines were developed in female athymic (nu/nu) nude mice.
[0085] The mouse tumors were intratumorally injected with AAV6 containing a luciferase transgene under control of a cytomegalovirus immediate early promoter (AAV6-CMV-Luciferase). Upon receiving an intraperitoneal injection of solution containing luciferin (the chemical substrate for luciferase protein), the HN12 tumors that received AAV6-CMV-luciferase showed a significantly elevated (15-fold) average radiance of 1.01×104±0.31×104 photons s−1 cm−2 sr−1, after subtraction of average background radiance, compared with the Hep-2 tumors (0.69×103±0.48×103 photons s−1 cm−2 sr−1) ( FIG. 7 ). This difference in transduction activity was also confirmed by quantification of vector genomes isolated from the tumors ( FIG. 8 ). The ability of AAV6 to efficiently transduce EGFR-expressing tumors in vivo presented an opportunity to target and deliver cytotoxic transgenes to HN12 tumors highly expressing membrane-localized EGFR.
Example 9
[0086] This example tests whether the specificity and tropism of AAV6 for EGFR expressing HN12 cells was sufficient to ablate tumor growth without damaging the surrounding EGFR-expressing muscle.
[0087] HN12 xenograft tumors were injected with AAV6 vectors encoding herpes simplex virus thymidine kinase (HSVtk) followed 7 days later by treatment with ganciclovir. At the culmination of the study (day 20), we observed a 65% reduction in tumor growth between tumors transduced with AAV6-CMV-HSVtk vector and treated with ganciclovir and tumors that received only ganciclovir treatment ( FIG. 9 ).
[0088] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0089] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0090] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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Comparative gene analysis (CGA) was combined with pathway visualization software to identify a positive correlation between AAV6 transduction and epidermal growth factor receptor (EGFR) expression. It was found that EGFR is necessary for vector internalization and functions as a co-receptor for AAV6. The identification and characterization of AAV6's requirement of EGFR expression for high transduction activity has allowed construction of recombinant AAV6 vectors which are capable of targeting and killing specific types of head and neck tumors that because of this high EGFR activity, were until now, refractory to current therapies.
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BACKGROUND OF THE INVENTION
The invention relates to a method and an apparatus for addressing a central memory for interrogating it with respect to stored data. The addressing takes place in dependence on external and time-dependent operational conditions of the engine which, itself, is controlled by the data contained in the central memory. In addition, one or more of the operational engine conditions may be dependent on other parameters, for example the engine temperature. The method and apparatus according to the invention for addressing a central memory is useful especially when used in connection with an electronic fuel injection system which uses the data in the central memory to generate a correction frequency which it transmits to a central processor for producing control pulses which are used in operating the fuel injection valves of the engine. However, the method and apparatus according to the invention is useful not only in the field of fuel injection but may be used wherever the operation of a system requires control in accordance with operational conditions which may be of very complicated form.
In order to define the duration of the fuel injection control pulses, which, in turn, are a measure of the fuel supplied to the engine, the induction tube manifold of the engine contains an air flow rate meter of any suitable construction and so embodied as to produce an electrical signal as a function of the air flow rate through the induction tube. In order to obtain an approximately stoichiometric fuel mixture, the signal thus produced, which is proportional to the air flow rate, is then divided by the rpm of the crankshaft, i.e., the number of suction strokes per unit time, in order to produce a fuel control datum. For this purpose, in a known fuel injection system in which the length of the pulses is formed by a monostable multivibrator having a capacitor in its feedback path, the capacitor is charged with a constant charging current during a time which is inversely proportional to the crankshaft rpm and is subsequently discharged with an equally fixed discharging current which, however, is inversely proportional to the air flow rate. The duration of the discharge of the capacitor is used as a measure of the duration of the fuel injection pulses. Connected behind this first stage in the known system is a so-called multiplier stage which operates in similar manner as the first monostable flip-flop and which receives correction signals related to other operational conditions of the engine which then are used by the multiplier stage to produce the final injection control pulses t i . In such known fuel injection systems, there is required an adaptation to the particular type of engine, so that it must be possible to change the system to correspond to the number of cylinders and to permit other adjustments and corrections.
The system according to the present invention relates to an electronic fuel injection system of substantially different construction, being based on digital operation and thus useable for universal applications, for example for generating highly precise injection control pulses for the fuel injection valves of an internal combustion engine. The data associated with a particular internal combustion engine are stored in a central fixed memory and are cyclically interrogated so as to correct the fuel injection control signal. In order to perform this cyclic interrogation and correction, there is required an address computer.
OBJECT AND SUMMARY OF THE INVENTION
It is a principal object of the invention to provide a universally useable address computer for addressing a central memory for the purpose of interrogating it regarding the data stored therein. The manner of addressing the central memory is to depend on several external operational conditions of the installation. The installation is preferably, but not necessarily, an internal combustion engine, and in that case the addressing may depend on at least one operational state, in particular the temperature, which is time-dependent and influences the values of the data of the other operational conditions in a previously known manner.
This object is achieved according to the present invention in a process for addressing a central memory by deriving switching signals from prevailing operational states of the installation, for example an internal combustion engine, and to feed these switching signals to a decoder which is cyclically traversed and which produces from the combination of operational states of the installation a single signal which directly controls an address memory. A first part of the address contained in the address memory and associated with the particular input signal is immediately transferred to the central memory while the remaining portion of the address is placed in a counter as an initial value. During a controllable gating period, the counter receives a clock pulse train whose frequency depends on at least one operational condition, for example the temperature, which is used by the counter to count upward from its previously set value so that, after the gating period is ended, the counter has a particular remaining content which is used as the final portion of the complete address fed to the central memory. If the operational state of the engine is such as to be temperature-independent, the gate permitting the passage of the pulse train to the counter remains closed.
The invention further provides an apparatus for carrying out the above-described process which includes a decoder circuit which receives switching signals related to the operational condition of the installation, for example an internal combustion engine, and cyclically generates a single signal which is fed to an address memory containing a plurality of preliminary addresses. The first portion (MSB) of these addresses is directly fed to the central memory for the purpose of a coarse selection of the correct data region while the remainder of the address is fed to a counter which is thus set while a temperature-dependent frequency is received by the counter to alter the set value and thus provide the remaining portion of the complete address fed to the central memory.
An address memory constructed and operated in this manner makes possible a very precise selection of a data word contained in a central memory for any possible combination of operational states of an installation, in particular of an internal combustion engine, and for the use of that datum for the processing of fuel injection control pulses. Furthermore, the apparatus of the invention is capable of processing the instantaneous values of time-variable quantities and to associate them with a stored datum without interpolation or approximations. The apparatus according to the invention can use and process the actually prevailing functional dependencies which are quantized for the purpose of storage in a digital memory.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed description of a preferred exemplary embodiment taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of an overall fuel injection system and an associated internal combustion engine, the main control circuitry being shown for simplicity in block diagrams;
FIG. 2 is a block circuit diagram of the address processor according to the invention in a basic configuration;
FIG. 2a is a diagram illustrating the fuel enrichment factor as a function of temperature during warm-up operation;
FIG. 3 is a diagram illustrating several possible events which take place during the calculation of the partial address for the central processor;
FIG. 4 is a detailed block circuit diagram of the address processor of the present invention;
FIG. 5 illustrates the cyclic timing of the access to the address memory for the conditions of starting and non-starting;
FIG. 6 is a detailed block diagram of the synchronizer circuit in FIG. 4;
FIG. 7 is a detailed illustration of the decoder circuit of FIG. 4;
FIG. 8 is a detailed illustration of the range selector circuit of FIG. 4;
FIG. 9 is a detailed diagram of the counter and the associated gating circuitry of FIG. 4; and
FIG. 10 is a timing diagram for illustration of the operation of a control circuit in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before turning to the detailed description of an exemplary preferred embodiment of the method and apparatus according to the invention, it should be noted that they are not limited to the application described here, i.e., the generation of fuel injection control pulses in an electronic fuel injection system. On the contrary, they are capable of application wherever an installation is to be controlled in dependence on particular operational states and on previously supplied operational information of any degree of complexity. Any possible kind and combination of operational conditions are assumed to be known and would be contained in data stored in a central memory. This memory would be interrogated with the aid of addresses which are constructed from the prevailing relatively complex operational states by the apparatus now to be further described.
In order to aid in the understanding of the construction and operation of the method and the apparatus according to the invention they will be described in relation to a fuel injection system such as shown in simplified form in FIG. 1.
FIG. 1 illustrates an internal combustion engine, for example a 4-cylinder, 4-cycle engine 1 having four fuel injection valves 2 which receive fuel to be injected from a distributor 3 via tubulations 4. Associated with the engine is an electrically driven fuel supply pump 5 and a pressure regulator 6 which holds the fuel pressure at some predetermined value, for example 2 atm gauge pressure. The system also includes an electronic injection device which defines the duration of the fuel injection control pulses that are delivered to the magnetic coil 7 of the injection valves in such a manner as to open the latter for a predetermined period of time during which an appropriately metered fuel quantity is delivered for example into the induction manifold or immediately into the particular combustion chamber associated with each cylinder.
The fuel injection system of FIG. 1 includes a central main processor 8 which generates a pulse sequence t e which controls the duration of the fuel injection control pulses. The pulse train t e is fed to a voltage correction circuit 9 which delivers corrected pulses t i to an output stage 10 which actually feeds the magnetic coils of the injection valves. The main processor 8 has an associated control portion 8a which receives input signals A and B which cause a switch-over of the system to 6, 8 or more cylinders.
As already mentioned, the entire system illustrated in FIG. 1 operates digitally, in particular the information delivered to the main processor is contained in the form of pulse trains of varying frequency. The main processor 8 and an associated computer 11, which will be designated a correction computer, receives signal trains or switching signals from an interface circuit 12 which are produced from input signals related to and derived from substantially the instantaneous behavior of the internal combustion engine. The main processor 8 thus is supplied with a pulse train f LM related to the air flow rate, a pulse train f n related to the engine speed (rpm) and a correction pulse train f K produced by the correction computer 11. The main processor uses these pulse trains to generate the output pulses t e which define the quantity of fuel supplied to the engine in dependence on the prevailing operational state.
Associated with the correction computer 11 is an address computer 14 which is connected to an interface circuit 15 and hence to a central memory 16 which contains data related to a particular internal combustion engine and which may be interrogated concerning these data in dependence on a prevailing operational state or combination of states of the engine. Thus, by reprogramming the memory or supplying a different memory, the system according to the invention provides a universal applicability of the fuel injection system for any and all internal combustion engines.
The present invention is primarily related to the address computer 14 and to portions of the interface circuits 12 and 15 which engage the central memory 16. After providing an address associated with a particular operational state, the address computer 14 receives from the central memory 16 a binary word associated with this particular address which, in the exemplary embodiment illustrated is an 8-bit word which is fed to the correction computer 11 for further processing and for generating a correction frequency f K . The frequency f K is used for counting down the contents of a counter located within the main processor 8, this counter having been counted upwardly during an interval in synchronism with the engine rpm at a frequency f LM related to the air throughput. The time period t e which extends from the onset of downward counting until the counter content is zero or some predetermined number is then used as a measure for the duration of the pulses generated by the main processor 8. As may be seen in FIG. 2, the central memory 16 is divided into regions 1, 2, 3 . . . n. The central memory contains data related to all of the operational states of the engine, whether dependent or independent of engine temperature. In the particular exemplary embodiment, there are defined fourteen individual operational states which are associated with fourteen regions 1 to n of the central memory 16. If the particular operational state of the engine whose associated datum is to be taken from the memory for further processing is temperature independent, then the associated region consists of a single 8-bit storage location. However, it is possible that some particular state of the engine, for example warm-up, has a considerable dependence on engine temperature. In that case, the central memory 16 must deliver a datum which corresponds to the amount of fuel needed by the engine at this particular time and also at the particular temperature. Of course, the amount of fuel actually required is previously known and is accordingly programmed into the central memory 16 in advance.
In the exemplary embodiment shown, the central memory 16 has a maximum of 32 8-bit words for temperature dependent conditions resulting in the allocations shown in Table 1 below. The glossary of abbreviations used in Table 1 is as follows:
Wl = warm-up,
Stwl = warm-up after engine starting,
Kns = correction for post-starting operation,
Aa is vehicle start increase, i.e., increased fuel supplied during the onset of motion of the vehicle (run-up),
Tl is partial load condition,
Ll is idling, and
Vl is full load.
Associated with these conditions are certain time constants and these are:
T λ k is the time constant for λ-control (short term),
T λ l is the time constant for λ-control (long term),
Tns is the time constant for post-starting,
Taa1 is the time constant for vehicle acceleration with warm engine,
Taa2 is the time constant for vehicle acceleration with cold engine,
Sttp is starting pulse duration, and
t min = minimum injection time.
The above referred-to λ-control describes a process of supplying fuel, i.e., of controlling the duration of injection pulses by a closed control process in which the condition of an oxygen sensor located in the exhaust system of a vehicle is used to derive information on the composition of the initial fuel-air mixture. Such a control process is known and will not be explained in further detail inasmuch as it relates only to the improved understanding of the apparatus in general.
TABLE I______________________________________CENTRAL MEMORY ALLOCATION Number ofWord address Content words______________________________________128 WL 32159160 STWL 16175 temperature176 KNS 16 dependent191192 AA 16207208 TL 1209 LL 1210 VL 1211 T λ K 1212 T λ L 1 temperature213 TNS 1 independent214 TAA1 1215 TAA2 1216 STtp 1217 t.sub.min 1______________________________________
The allocation of the central memory depicted in Table 1 indicates that the initial location is the location 128, although this is an arbitrary choice. However, if a memory having a total of 256 words is used, then such a memory may also be used for the purpose of feeding other single-purpose computers in a motor vehicle, for example ignition computers, transmission control computers, etc. In the present case, the locations 128 to 217 of the central memory 16 are occupied by the above-referred to regions 1 to 14. Table 1 also indicates which of the operational states of the engine are temperature-dependent which requires that the prevailing temperature must be considered in the formation of the address fed to the central memory.
When the central memory 16 receives the desired address at its inputs, its output produces the associated datum for further processing.
The generation of the addresses, of which there are 89 in the present example, takes place by means of the components shown in simplified form in FIG. 2. It will be noted that the operational condition labeled WL, i.e., the warm-up of the engine, will require the highest number of quantization steps in a motor vehicle, in this example a total of 32 quantization steps corresponding to 32 memory locations. Thus, when the central memory is interrogated regarding the warm-up operation of the engine, it will supply one of 32 values each having a length of 8 bits. In the other temperature dependent operational states, namely warm-up during starting, in the correction factor for post-start increase and in that for vehicle acceleration it is sufficient to use 16 quantization steps, i.e., 16 memory locations, resulting in a total of 80 memory locations required for the various temperature dependent engine states. If the memory is associated exclusively with a fuel injection system of the above-described type, its total storage content would need to be only 89 8-bit words and could be embodied as a read-only memory (ROM) or programmable read-only memory (PROM).
The 14 various operational states of the engine are defined in the present exemplary embodiment by four switching signals, namely an idling signal LL, a full load signal VL, a start signal ST and a λ-control signal Sλ. All these control signals are derived in relatively simple manner, for example by means of switches located at the gas pedal or the ignition, and are fed to an address preselector circuit 18. A signal related to engine temperature is derived by means, for example, of an NTC resistor located in the coolant of the engine. This sensor supplies the input parameter θ to the block labeled 19 in FIG. 2. The address preselector 18 includes a synchronizing circuit which places the input signals LL, VL, ST and Sλ into a common time frame. The circuit 18 further includes a selector circuit and a fixed value memory (ROM or PROM) with a capacity of 14 8-bit words. The circuit 18 uses the information contained in the 14 previously mentioned operational states of the engine and derives therefrom a preliminary address. This preliminary address is divided into a 3-bit word which is part of the complete 8-bit address for the central memory 16 and into a second 5-bit word which is fed to a counter 19 for setting the counter to a predetermined initial value. The 3-bit word fed directly to the central memory 16 is composed of the three most significant bits (MSB) whereas the 5 LSB (least significant bits) are fed to the counter 19 whose capacity is required to be only 5 bits in the present example.
The counter 19 is a customary counter composed, for example, from so-called J-K flip-flops which may be loaded in parallel and which may be clocked in a predetermined gating time T.sub.θ at a clock frequency f.sub.θ. The block labeled 19a receives the temperature signal θ and generates therefrom a temperature-dependent frequency especially a linearly related frequency. The element 19 may be, for example, a resistance-controlled oscillator which, ideally, generates a pulse train whose frequency f.sub.θ is a linear function of the temperature. Oscillators of this type, in which a variation of a resistance changes the output frequency, are known and the particular oscillator 19a will thus not be described in further detail.
During the fixed gating time T.sub.θ the up-counter continues to count at the frequency f.sub.θ from the content Za which had been set by the address preselector 18 until it reaches a terminal content which is derived according to the following formula:
Z.sub.e = Z.sub.a + F.sub.θ · T
after the expiration of the gating interval the up-counter 19 thus contains a certain 5-bit word which, together with the 3 MSB bits from the fixed memory, forms the 8-bit address for the central memory 16. Thus, when the engine is in operational conditions and delivers status signals such as WL, STWL etc., which indicate temperature-dependence, the address also becomes temperature-dependent. If the status signals of the engine indicate a condition which is not temperature-dependent, the counting input to the counter 19 is blocked so that the 8-bit address fed to the central memory 16 by the address preselector 18 is temperature-independent.
FIG. 2a illustrates how the amount of fuel delivered to the engine increases as a function of decreasing temperature where the abscissa is indicative of temperature while the ordinate indicates fuel quantity. The particular curve corresponding to the engine behavior is known in advance and, if the status signal WL is active, corresponding to warm-up operation, the curve is divided into 32 steps so that the central memory 16 stores 32 words of 8-bit length corresponding to the temperature range of interest during the warm-up of the engine. Depending on the temperature-dependent counter frequency f.sub.θ received by the counter 19, the 5-bit address portion generated by the counter 19 is used to select one of the 32 words in the central memory 16, namely that word which corresponds to the temperature region Δ.sub.θ which is included in the region defined by the word within the memory. The central memory 16 then delivers a datum which, in the particular example illustrated, corresponds to the numerical value 1.05 for the particular range of temperature Δ.sub.θ.
A further substantial advantage derives from pre-loading the up-counter 19 with a 5-bit word from the ROM in the address preselector 18. This advantage is based on the fact that the capacity of the counter 19 is 5-bits so that the frequency f 74 would have to span a dynamic range of 1:32 for a full utilization of the capacity of the counter 19. Such a large dynamic range is impossible to realize in practical applications. By charging the counter 19 with an initial value from the fixed memory or from some other source, the 0 point is suppressed and the partial address formed by supplying the counter frequency f.sub.θ is expanded over the entire capacity of the memory. For this reason, the ratio between f.sub.θmax and f.sub.θmin need only be as large as the factor 2.
Turning now to FIG. 4, there will be seen in greater detail the construction of the address preselector circuit 18 which receives the input switching signals LL, VL, ST and Sλ. The circuit 18 includes a synchronizer circuit 21, a subsequent decoder circuit 22 and the previously referred-to fixed value memory 23 which may be a ROM or PROM memory and which has a capacity of 14 times 8-bits. The 14 8-bit words are directly addressed by individual lines from the prior decoder circuit 2 and the output of the fixed memory carries an 8-bit pre-address depending on the cyclically available status symbol WL, STWL etc. As already mentioned, four of the 23 status signals which control the fixed memory, i.e., the words WL, STWL, KNS and AA are temperature-dependent and the initial values delivered by the selector memory 23 to the counter 19 are values which are smaller than the numerical value 31 and thus represent a value which depends on the dynamic range of the oscillator frequency which is then combined with the sum derived from the frequency supplied during the gating period to generate the correct address for the central memory 16. The 5-bit words reaching the counter 19 but related to the remaining status signals which are not to be influenced by the temperature-dependent frequency f.sub.θ are equal to the values of the final address because they are transmitted by the counter 19 without change. These initial value addresses occupy locations 80 to 89 in the central memory 16 (according to Table I) and if the address count starts at the number 128 they occupy the addresses 208 to 217. An allocation scheme of the address memory 23 is illustrated in the Table II below.
TABLE II__________________________________________________________________________ALLOCATION OF ADDRESS MEMORY A8 A1Word Content Initial Address MSB A7 A6 A5 A4 A3 A2 LSB__________________________________________________________________________0 empty 01 STWL <31 + 32 fixed 0 0 1 X X X X X2 WL <31 0 0 0 X X X X X3 TL 80 0 1 0 1 0 0 0 04 KNS <31 + 32 fixed 0 0 1 X X X X X5 AA <31 + 64 fixed 0 1 0 X X X X X6 LL 81 0 1 0 1 0 0 0 17 VL 82 0 1 0 1 0 0 1 08 T λK 83 0 1 0 1 0 0 1 19 T λL 84 0 1 0 1 0 1 0 010 TNS 85 0 1 0 1 0 1 0 111 TAA1 86 0 1 0 1 0 1 1 012 TAA2 87 0 1 0 1 0 1 1 113 STtp 88 0 1 0 1 1 0 0 014 tmin 89 0 1 0 1 1 0 0 1__________________________________________________________________________ X = variable initial address, depending on dynamic range of the temperature-dependent oscillator frequency.
Table II indicates that the 3 MSB of the address memory 23 are used as a fixed address for the choice of the regions 1 to n and are delivered directly to the central memory 16, whereas the 5 LSB bits of the address memory 23 are used as a pre-address for the 0 suppression of the counter 19 and are supplied to the jam inputs L 1 to L 5 .
The system of the invention also includes a main divider circuit 30 which uses a basic frequency f 0 , generated, for example, by a quartz-stabilized oscillator and having a value of, for example, 600 kHz for generating a multitude of sub-frequencies by simple division. These sub-frequencies have a fixed phase relationship and are used to control and force-synchronize the entire cyclic operation of the address processor. The sub-frequencies are labeled P 1 to P 17 and are used at various points of the entire circuit for controlling the temporal processes occurring there. The following Table indicates the frequency allocation for a practical embodiment of the invention.
TABLE III______________________________________FREQUENCY ALLOCATIONP1 200 kHzP2 100 kHzP3 50 kHzP4 25 kHzP5 12.5 kHzP6 6.25 kHzP7 3.125 kHzP8 1.5625 kHzP9 781.25 HzP10 390.625 HzP11 195.3125 HzP12 97.65626 HzP13 48.828125 HzP14 24.4140625 HzP15 12.20703125 HzP16 6.103515625 HzP17 3.0517578125 Hz______________________________________
Turning now to FIG. 4, it will be seen that the temperature-dependent pulse train f.sub.θ whose phase is random is fed, firstly, to a frequency synchronizer unit 24 which transforms it into a synchronized counting frequency f.sub.θs. This may be done, for example, in simple manner by the use of bistable flip-flops triggered by one of the frequencies P 1 and P 6 wherein the synchronizer unit 24 delivers a pulse whenever a synchronizing pulse as well as an f.sub.θ pulse are present simultaneously. By appropriate rapid clocking, a forced synchronization is achieved without loss of resolution. The frequency synchronizer unit 24 not only translates the temperature-dependent pulse train f.sub.θ into a fixed frequency-time frame but also performs a single pulse generation, i.e., a possible pulse to pulse interval ratio of 1:1 of the temperature-dependent pulse train is reduced to the pulse duration of the clock pulse train frequency.
There is further provided a gate circuit 26 which receives the synchronized temperature-dependent frequency f.sub.θs and which releases it to the counter 19 if an appropriate control signal is fed to it by a gate control circuit 27. The detailed construction of these circuits is given further below. The gate control circuit receives the clock frequencies P 8 and P 9 and uses them to generate a gating pulse of duration 0.64 ms (used in the present exemplary embodiment although other values are possible) or a gating time t.sub.θ of 0.32 ms and feeds these gating periods to the gate circuit 26. The clock frequencies P 8 and P 9 are used because they have frequencies, respectively, of 1.5625 kHz and 0.78125 kHz which correspond to the desired pulse lengths of 0.64 ms and 1.28 ms. Thus, the gate control circuit 26 permits the frequency f.sub.θs to reach the counter 19 during a period 0.64 ms and to be added to a fixed initial valve placed in the counter 19 by the address pre-selector memory 23. This initial value is indicated in FIG. 3 and corresponds to the numerical counter content 27. When the counting sequence f.sub.θs reaches the counter during the open gate period, three separate cases may result and these will now be studied in detail. If the pulse train f.sub.θs corresponds to a temperature between -30° C to +40° C of the engine, then the counter 19 will be filled up quickly starting with its initial value and will be reset to 0 where it begins to count anew as shown in FIG. 3. In that first case, the temperature-dependent frequency f.sub.θs corresponds to a normal temperature region so that, within the gating time T.sub.θ, the final content in the counter lies between 0 and the maximum and constitutes the remaining 5-bit LSB address for the central memory 16. This normal case requires no further discussion.
On the other hand, it would be possible for the temperature of the engine to be so high that, after the first permissible overflow of the counter 19 which is recognized by a range sensor circuit 28 which will be described in further detail below, there takes place within the gating time t.sub.θ a second overflow, i.e., as illustrated for case 2 of FIG. 3. Thus, the counter reaches its maximum content a second time and if it were not prevented from doing so, it would begin to count anew from 0 and would deliver a completely erroneous value as an address at the termination of the gating period. In this case, the range sensor circuit 28 causes the counting process to be interrupted after the second maximum count is reached and to retain that count for delivery to the central memory. On the other hand, it is also possible that the counter frequency corresponding to a low temperature is so low as to constitute the situation depicted in case 3 of FIG. 3., i.e., the counter never reaches even the first overflow condition. In that case, the final content is also incorrect and would be indicative of a very high temperature, i.e., exactly contrary to the prevailing condition. In such a case, the range sensor circuit 28 ignores the outputs Q 1 to Q 5 of the counter 19 and generates its own address corresponding to the lower limit of temperature. This is done with the aid of a low temperature addressor 29 which is associated with the range sensor circuit 28 and operates at the lower temperature limit.
There are thus the following three separate cases:
Case 1: At the termination of the gating time T.sub.θ, the counter content lies between a lower and an upper limiting value. This counter content is used as an address and transmitted to the main memory 16.
(θ.sub.UG < θ < θ.sub.OG).
case 2: During the gating time, the upper limiting value is reached a second time. In that case, the range sensor circuit 28 blocks the counter and the upper limiting value is used as an address for the central memory 16 (θ = θ OG ).
Case 3: During the gating time, the upper limit is never reached and in that case a low temperature addressor is activated to generate an address corresponding to the lower limiting value of the counter, i.e., all outputs are set to 0 (θ = θ UG ).
It has already been mentioned that the status WL, i.e., the warm-up condition of the engine, requires the most precise set of data and therefore this status commands 32 separate 8-bit words in the central memory 16. Thus, the status WL is permitted a maximum content of 31 in the up-counter 19 while the 3 MSB coming from the pre-addressor 23 define the WL region within the central memory per se. A similarly precise quantization is not required even for other temperature-dependent states which only require 16 words in the central memory so that the counter 19 is required to count only to a maximum content of 15. The counting capacity is reduced to one-half by limiting the gating time T.sub.θ to half the value it has during the status WL, i.e., in the present exemplary embodiment to 0.32 ms for the states AA, KNS and STWL. The gating time is selected depending on the value of the logical signal WL. When WL is a logical 1, the gating time T.sub.θ is 0.64 ms in the illustrated exemplary embodiment.
The 14 status signals or operational conditions which are used in the present example, and which are fed as input lines to the address memory 23 of FIG. 4, are generated by the decoder circuit 22 which selects one of 14 output lines. In addition, the choice of these outputs is controlled cyclically, i.e., there is a sequential interrogation with the clock sub-frequencies P10, P11 and P12 which are delivered to the decoder circuit 22. This results in a signal capacity of 3 bits, i.e., eight possible states, and Table IV below indicates the sequence of access to the address memory 23.
TABLE IV______________________________________SEQUENCE OF MEMORY ACCESS Start No StartCycle STs = 1 STs = 0______________________________________T1 STWL WLT2 STtp TλL, if Sλ = 1T3 tmin tminT4 NS TλK, if Sλ = 1T5 AA AA onceT6 TL TL, LL, VLT7 TAA TAA if Sλ = 0T8 TNS TNS if Sλ = 0______________________________________
These eight possible states, i.e., the cycles T1 to T8 occur in sequence and Table IV indicates the association of the status signals with the eight partial cycles T1 to T8. In the exemplary embodiment, each of these cycles has a length of 1.28 ms (see FIG. 5) so that the repetition frequency for the same cycle is 97.65 Hz and is equal to the sub-frequency P12. During the cycle time of 1.28 ms, one of the 14 possible status signals is activated so that the appropriate address from the address memory 23 causes the setting of the counter 19 with the 5 LSBs and if necessary, for temperature-dependent values, the counter is then supplemented for forming the complete address for the central memory 16. Sufficient time then still remains for the central memory 16 to deliver the datum corresponding to that address to a bus interface circuit 15 (FIG. 1) which delivers it to the corrector circuit 11 for the formation of the correction frequency f K . Thus, the remaining time suffices for generating the address and for a complete data exchange between the central memory 16 and the correction circuit 11.
The cycles T1 to T8 obey the association shown in Table IV throughout the system, thus eight cycles suffice for the cyclic interrogation of the 14 status signals because the engine is either being started or it is in normal operation. Thus, an unequivocal association of the status symbols and the eight cycles T1 to T8 is guaranteed.
The exact construction of the central memory 16 need not be discussed because such memories for storing a multitude of 8-bit words or words of other length are known in the state-of-the-art. The memory receives an address on lines AD 1 to AD 8 during a certain period of time and the memory has an internal decoder circuit which performs a one-of-256 selection and delivers the chosen stored datum in parallel at its output terminals. It is possible to use any desired type of memory which performs the function of translating an address into an output of a stored datum or binary word.
FIG. 5 is a timing diagram illustrating the access to the address pre-selector memory 23. In what follows, the individual circuits shown in FIG. 4 will be discussed in more detail and their cooperation for performing the previously discussed functions will also be treated.
FIG. 6 is a detailed diagram of the synchronizer circuit 21. In the present exemplary embodiment, that circuit includes 4 bistable multivibrators 30, 31, 32, 33 as well as a counter 34 whose function and purpose will be explained below. The bistable multivibrators are preferably so-called "D" flip-flops, for example those marketed by the firm RCA under the type number 4013. Such flip-flops are so designed that, at certain times, i.e., under forced synchronization, signals present at the inputs 35 to 38 are transferred to the outputs. The times during which the transfer occurs are defined by the pulse sequence P9 which is connected to the synchronizing inputs of the flip-flops 30 to 33. This prevents the possibility that a particular input signal switches logical states during the occurrence of one of the clock cycles T1 to T8. The clock sequence P9 insures that the output of the flip-flops 30 to 33 retains that logical state during the entire period of a P9 cycle which was present at the beginning of that cycle. The input signals to the flip-flops 30 to 33 are the logical signals LL, VL, ST and Sλ, already seen in FIG. 4, which may be generated as analog signals by appropriate switches or contacts designated with the numerals 39 to 42. It will be observed that the clock pulse sequence P9 has a force-synchronizing effect since an idling signal coming from the switch 39, for example, will be accepted by the flip-flop 30 as a synchronized idling signal LL s only if, at the same time, the clock pulse sequence P9 exhibits the state of a logical 1. This logical state is then maintained by the flip-flop during the timing interval of P9 even if the logical signal LL at the input of the flip-flop 30 were to revert to its other state. FIG. 6 shows that the outputs of the flip-flops 30 to 33 carry the synchronized switching signals and their complements. All of the pulse trains P1 to P17 are suitably rectangular pulses with a keying ratio of one-half. By connecting the pulse sequence P9 to each of the flip-flops 30 to 33, these flip-flops transmit the input signals coming from the switches 39 to 42 and introduce them into the synchronous time frame of the entire system.
FIG. 6 also shows a counter 34 which will be designated an idling counter and may be, for example, an integrated circuit of the type 4029 marketed by RCA. In order to improve the understanding and construction of this counter, the following conditions will now be explained. In the access scheme to the memory, and during the cycling period T5, there is provided a vehicle run-up enrichment AA which delivers to the engine an enriched fuel-air mixture whenever the engine is accelerated from idling. This action prevents stalling the engine during the initiation of vehicle motion. Basically, the order for starting enrichment could be provided by the idling signal LL but that signal also occurs if the operator of the vehicle changes gears or for some other reason and having nothing to do with vehicle motion but causing the gas pedal to return to idle. In that case, the central system of the electronic fuel injection system would produce a richer mixture during each gear change and result in unduly enriched fuel-air mixtures. To prevent this occurrence, the counter 34 is provided. A basic assumption will be that any gear change would require less than approximately 2 to 3 seconds, i.e., any gear change during which the idling signal LL appears would be terminated after 2 seconds. Thus, if the LL signal still occurs after a predetermined time period, in the exemplary embodiment a time period of 2.62 seconds, then the conditions are assumed to be a true initiation of motion and the engine will thus be assumed to require the run-up enrichment AA. To perform this decision, the idling counter 34 is a 3-bit counter in the present example and receives the counting sub-frequency P17 equal to 3.05 Hz. Thus, after 2.62 seconds have elapsed the output A 1 of the idling counter 34 exhibits a logical 1 and places the subsequent bistable flip-flop 43 into one of its states. This state is interrogated at the time T5 and is used for run-up enrichment. The flip-flop 43 is also force-synchronized by receiving the sub-frequency P9 and also has a reset input which receives the AA signal itself so as to be resettable to its initial state and to prevent a run-up enrichment every time it is interrogated at the time T5. The counter 34 is released by the idling signal LL s or its complement LL s so that the entire process takes place only if at least the idling signal LL is present.
FIG. 7 illustrates one possible embodiment of the decoder circuit 22 of FIG. 4. The decoder circuit 22 uses the information present in this case in the form of 4 synchronized signals which are present in cyclic sequence corresponding to the cycling pulses T1 to T8 and generates the status signals fed to the address memory 23 depending also on whether the engine is being started or not. Actually, the specific construction of the logical connection circuitry which operates as a decoder 22 is somewhat arbitrary, the only pre-requisite being to achieve the desired function. The exemplary embodiment illustrated in FIG. 7 is one way of coupling the clock frequencies P10, P11, and P12 with control signals derived from the operational behavior of the engine and thus to derive the signal sequence corresponding to the cycles T1 to T8 and to form the 14 status signals.
Since, in principle, the number, type and kind of status signals is arbitrary, the representation of FIG. 7 relates only to a special exemplary embodiment. However, when the status signals have once been designated with respect to type and formation, the same circuit may be used for all engines. Any adaptation to other engines would take place by changing the contents of the main memory. Thus, it is possible to take a particular and fixed exemplary embodiment of the invention and to embody it as an integrated circuit in an LSI-chip which would make subsequent changes impractical. The universal adaptability of the circuit according to the invention makes it possible to dispense with a detailed discussion of the various signal trains deriving from the circuit. Any person skilled in the art is able to refer to the various AND, NOR and NAND gates 45 to 70 in FIG. 7 and to derive therefrom the association with the operational signals as well as the timing sequence of the status signals. Furthermore, the generation of the static analog input signals LL, VL, ST and Sλ also depends on the engine types, for example the idling signal LL as well as the full-load signal VL are often produced by establishing a contact to ground so as to produce a logical 0 signal. One special condition of the decoder circuit 22 should be mentioned separately, namely that the run-up enrichment AA should and can be triggered only if the idling condition has been definitely established beforehand which is recognizable from the switching state of the flip-flop 43, already described with respect to FIG. 6, whose output signal QL s is fed to a NOR gate 17. The other input of the NOR gate receives an LL s signal. When the LL s signal is a logical 0, the idling condition is no longer present. Thus, the output of the NOR gate 17 provides the condition that there has been an idling condition and was correctly recognized, i.e., that it endured longer than the 2.62 seconds of the present example and corresponding to the static output signal QL s of the flip-flop 43 and that an idling condition no longer obtains (corresponding to the LL s signal). Only then is the AA output signal generated in the cyclically predetermined time, i.e., at the clock time T5. At the same time the flip-flop 43 is reset, as already mentioned, so that the QL s signal disappears and no enrichment takes place at the next interrogation at the subsequent time T5. The other coupling circuits of FIG. 7 operate in similar manner, the input signal ST s of the decoder circuit 22 being particularly significant because, according to the contents of Table IV, this starting signal ST s is responsible for dividing the total of 14 output status signals over the eight cycling times T1 to T8.
FIG. 8 illustrates the blocks 27, 28 and 29 in greater detail and they will now be discussed with the aid of the various possible counter conditions illustrated in FIG. 3. As has already been discussed, the up-counter 19 must be permitted to overflow at least once so that, in the normal case 1, the final counter content will be between 0 and 31 for the status WL or between 0 and 15 for the conditions AA, KNS or STWL. If the counter does not overflow at all, then the address portion supplied by the counter will be equal to the lowest temperature and will be transmitted via lines AD1 to AD5 which will carry a logical 0 for transmission to the central memory 16, (corresponding to the case 3 of FIG. 3).
If the counter attempts to overflow a second time, the partial address formed by the 5 LSBs will be made a logical 1 and will correspond to the highest designed temperature.
These decisions are made by the range sensing circuit 28 which senses the signals AD1' to AD5' present at the outputs Q1 to Q5 of the counter 19. It includes a NOR gate 74 which responds to the first overflow of the counter 19 and produces a logical 1 if the outputs Q1 to Q5 of the counter 19 are identically 0. Subsequent to the NOR gate 74 is connected a bistable flip-flop 75 which is set into one of its states by the logical 1 from the NOR gate 74 thereby producing its own output a signal UG which is fed to a NOR gate 76 of the address switcher 29 as will be explained below.
The range sensing circuit 28 has a further NOR gate 77 which also receives the output signals AD1' to AD4' of the counter 19 as well as the output signal AD5' which, however, first travels through a supplementary NOR gate 78. The NOR gate 77 also receives the output signal UG of the flip-flop 75 which prevents the NOR gate 77 to respond at the first overflow of the counter 19. The circuit which recognizes the second overflow of the counter 19 (corresponding to Case 2 of FIG. 3) is so constructed that a signal OG (a logical 1) is generated when the first overflow of the NOR gate 74 has been sensed and the flip-flop 75 has been set. The input signals AD1' to AD4' are fed to the NOR gate 77 via inverter 79 as is the signal AD5' which comes via NOR gate 78. If all of the inputs of the NOR gate 77 show a logical 0, the gate produces the signal OG and, as seen in FIG. 4, feeds it to the gate circuit 26 which interrupts the counting process of the counter 19 and holds the contents of the counter at the logical state 1 in all locations which corresponds to the maximum planned temperature. The purpose of bringing in the signal AD5' via NOR gate 78 which also receives the signal WL (corresponding to the status signal "not WL") has the sole purpose of admitting the counter content 31 as the upper limit for the WL status signal if the OG signal was already produced at the counter content 15 without the presence of a status signal WL.
The illustration of FIG. 4 includes a block 80 which produces an output signal ZF.sub.θ during the presence of one of the operational states WL, STWL, NS or AA, i.e., if, in general, a temperature-dependent address is to be calculated. In that case, the signal ZF.sub.θ is a logical 1 and flows through a NAND gate 81 (see FIG. 8) belonging to the low temperature addressor 29 to the subsequent NOR gate 76. This is done for the following reason. If there are no temperature-dependent states or status signals, the input of the counter 19 must be transmitted without change to its output without interference by the range sensor circuit 28. However, if the flip-flop 75 has not yet registered a first overflow and has therefore not been set, the range sensor circuit holds the outputs AD1 to AD5 at a logical 0 via the NOR gate 76 due to the absence of the signal UG, i.e., the output of the NOR gate 76 blocks in this case the subsequent NOR gates 82, 83, 84 and 85 as well as a further coupling circuit 87 leading to the output AD5 so that the outputs AD1 to AD5 all show a logical 0. However, this is permitted only if a temperature-dependent address is to be calculated, i.e., if the signal ZF.sub.θ is at the same time a logical 1 or if ZF.sub.θ is a logical 0. In this case, and for temperature-dependent addresses, one input of the NOR gate 76 sees the signal ZF.sub.θ = 0 and the other the signal UG = 0 so that the output of the NOR gate 76 is a logical 1 and, as will be easily seen, the outputs of the NOR gates 82 to 85 are locked into the value logical 0 independently of the logical state present at the other input of the NOR gates 82 to 85. Thus, the conditions previously explained in detail with respect to Case 3 are achieved. On the other hand, as already mentioned, this state should not occur if the address generation is not, in fact, temperature-dependent. In that case, the range sensor circuit should not block the outputs AD1 to AD5 at logical 0 corresponding to the lower limit. If the signal ZF.sub.θ is absent, and thus ZF.sub.θ is 1, then, prior to the switch-over of the flip-flop 75 (corresponding to a signal UG = 0), the output of the NOR gate 76 always has a logical 0 so that any signals coming from the counter 19 are permitted to pass through unchanged. This is possible because the signals AD1' to AD5' reach the other inputs of the NOR gates 82 to 85 via inverters 86.
The transport and switching of the AD5' signal is performed by a coupling circuit 87 including three NAND gates which also receives the negated signal KNS. Let it be assumed for clarity that the signal AD5' which occurs at the output Q5 of the counter 19 is processed in the same way as the signals AD1' to AD4', then the coupling by NAND gates is required because it may not be assumed in advance for all address regions that the lower limit in all locations is 0. However, this is not important for the overall consideration of the present address processor and is mentioned only supplementarily.
FIG. 8 finally also includes the gate controller circuit 27 which includes a NOR gate 88 ahead of two bistable flip-flops 89 and 90. One of the inputs of the NOR gate 88 receives the system clock pulse train P9 whereas the other input of the NOR gate 88 is connected to the output of a further NOR gate 91 whose one input receives a signal WL and whose other input receives the inverted system clock pulse train P8 whose inversion takes place via a NOR gate 92. Both flip-flops 89 and 90 also receive the highest system clock rate f 0 for the purposes of synchronizing the switching states. By coupling of the two clock rates P9 and P8, while considering the signal WL, the output of the flip-flop 90, which may be a "D" flip-flop just as was the flip-flop 89, produces the gating time T.sub.θ, whose duration is either 0.64 ms or, if no warm-up conditions prevail, 0.32 ms. As will be seen in FIG. 4, this gating signal T.sub.θ is fed to the gating circuit 26 which will be mentioned again in connection with FIG. 9. A subsequent NOR gate 92 uses the front edge of the gating signal T.sub.θ to form therefrom a single preset enable pulse PE. The pulse PE is delivered to the counter 19 (see FIG. 4) and insures that the counter accepts the partial address from the address memory 23 consisting of the first five LSBs present at its inputs L 1 to L 5 and subsequently counts from that number at the rate F.sub.θs.
The switching states of the "D" flip-flops 89 and 90 are then utilized to generate a signal X, a so-called request signal which will be a logical 1 at the expiration of the gating time T.sub.θ. For this purpose, a further NOR gate 93 receives one output of the flip-flop 89 and the other output of the flip-flop 90. The request signal X is not used within the address processor but serves the purpose of informing subsequent systems, especially the central memory 16, that the address has been calculated and is ready for transfer.
FIG. 9 illustrates in more detail the synchronizing circuit 24 and the gate circuit 26. The synchronizing circuit 24 includes a first flip-flop 95, again embodied as a "D" type flip-flop, which receives the basic clock frequency f 0 as well as the still free-running temperature-related frequency f.sub.θ. The output of the flip-flop 95 is connected to the input of a subsequent flip-flop 96 whose output is finally connected to the input of a NOR gate 97. This NOR gate 97 is also part of the gating circuit 26 because one of its other inputs receives the signal OG coming from the output of the NOR gate 77 in FIG. 8, related to the recognition of the second overflow of the counter 19. It may be observed that, when the signal OG is a logical 1, the NOR gate 97 is blocked and its output will be exclusively 0 independently of any conditions at the other two inputs. In this manner, the passage of the temperature-dependent frequency f.sub.θs to the counter 19 is reliably interrupted if the counter reaches the maximum value a second time, corresponding to Case 2 in the illustration of FIG. 3. The output of the NOR gate 97 is connected with a NAND gate 98 which constitutes the main component of the gating circuit 26. The other two inputs of the NAND gate 98 receive, firstly, the above-mentioned signal ZF.sub.θ which, when equal to a logical 1, indicates a temperature-dependent address. The third input of the NAND gate 98 receives the gating signal T.sub.θ. If all of the input signals of the NAND gate 98 exhibit a logical 0, its output is a logical 1 and when the logical state at the central connection of the gate 98, i.e., the one receiving the frequency f.sub.θs, changes, the output of the NAND gate 98 also changes and this output is connected to the counting input of the subsequent counter 19. In the exemplary embodiment shown, the counter consists of two sequential four-stage binary counters of known construction which need not be discussed in detail; these counters may be, for example, the RCA counter type 4029. The preset enable inputs of both counters receive the above-mentioned signal PE.
The preselect address memory 23 shown in FIG. 9 also includes the decoder circuit 22 which, in many practical examples of this circuit, is an integral constituent of such memories. The address memory 23 and the decoding circuit 22 may be, for example, the PROM memory MF 1702 made by the firm Intel.
FIG. 10 is a timing diagram which illustrates the generation of a gating pulse T.sub.θ, the signal PE and the request signal X with the aid of which the gate control circuit 27 will now be discussed briefly. The trace 10a shows the basic clock frequency f 0 which is used for synchronization and for triggering the "D" flip-flops 89 and 90 in parallel. Considering first the case of an operational status WL, i.e., the WL signal has the value 1. In that case, the output of the OR gate 91 is always 0 and the only clock frequency to be considered is P9 which, when observed behind the NOR gate 88, has the appearance illustrated in the trace 10b. By inverting the frequency of P9 as given in Table III, it may be seen that the period for this pulse train is 1.28 ms so that the duration of the signal state logical 1 at this frequency is 0.64 ms. The frequency P9 is fed to an input of the flip-flop 89 which, as may be seen in FIG. 10c, changes states again at the arrival of the front edge of the next clock pulse f 0 . The following front edge of the clock pulse then also flips the subsequent flip-flop 90 into its other state and thus produces the pulse signal for the gating time T.sub.θ. The inverted output of the flip-flop 89 and the non-inverted output of the flip-flop 90 are fed to the NOR gate 92 so that the PE signal of FIG. 10e is the difference of the pulse trains of FIG. 10c and FIG. 10d. In similar manner and as not further explained in detail, the request pulse X illustrated in FIG. 10f is generated by means of the non-inverted output of the flip-flop 89 and of the inverted output of the flip-flop 90.
When the status signal WL is 0, the switching states are derivable in similar manner. In that case, the presence of the NAND gate 92 causes the output of the NOR gate 91 to display the normal clock pulse sequence P8 which, together with the sequence P9, reaches the NOR gate 88 so that, after appropriate inversion, there is generated the pulse sequence shown in FIG. 10g which remains in a logical state 1 for the time of 0.32 ms. The other pulse durations are given by the curves in FIGS. 10c, d, e and f and may be derived from the curves 10h for the gating time T.sub.θ, 10i for the PE pulse and 10k for the request pulse X.
It should also be pointed out that the exemplary embodiment in its special configuration has illustrated considerable detail for the purpose of improving the comprehension of the apparatus and the construction of the system, its operation and the various status signals. It should be understood, however, that, depending on the type and construction of the coupling circuits, especially that of the decoder 22, other operational states may be monitored and controlled and that the various input variables to the system according to the invention could be different.
Finally, it will be observed that a circuit as described above is especially well suited for large scale integration (LSI), particularly because the technological principles employed in its construction are easily integrated on an LSI-chip.
The foregoing relates to a preferred embodiment of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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A central digital memory contains data relating values of operational variables of an installation to values of a stored parameter. The central memory is addressed in parallel via input lines carrying the address of the stored data. The address is generated by selecting one of several discrete input lines leading to an address selector memory which contains preliminary addresses related to the various operational states of the installation. A portion of the preliminary address is delivered directly to the central memory whereas another portion is used to preset a counter. If the particular operational state is dependent on another parameter, for example temperature, a temperature-dependent clocking frequency is admitted to the counter and alters its contents which are then used to supplement the first portion of the address already delivered to the central memory. If no temperature dependency exists, the second portion of the address is passed on without change.
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BACKGROUND AND OBJECT OF THE INVENTION
This invention relates to a weft inserting device for a jet loom of the type in which a plurality of main nozzles adapted for inserting weft yarns are respectively associated with the same plurality of supply units supplying said weft yarns. It is the object of the present invention to provide a weft inserting device for a jet loom, according to which a desired one of the main nozzles may be placed at the proper timing in readiness for weft insertion in accordance with a preset weft yarn selecting program.
SUMMARY OF THE INVENTION
With the above object in view, according to the weft inserting device of the present invention, reciprocating motion of a driving member of the jet loom is transmitted to a main nozzle change lever in accordance with a weft yarn selection program. According to a preferred embodiment, the driving member is a cam lever that is swung in reciprocation with rotation of the cam plate. The swinging movement of the cam lever is transmitted to the change lever carrying a pair of main nozzles in accordance with preset weft yarn selecting program.
According to the present invention, desired ones of the main nozzles may be used selectively and in different ways by properly formulating the program and without the necessity of changing mechanical design.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will become more readily apparent from the following description of preferred embodiments shown, by way of example only, in the accompanying drawings, in which:
FIG. 1 is a diagrammatic plan view showing a preferred embodiment of the present invention;
FIGS. 2 through 5 are diagrammatic side views for explaining the operation of the embodiment shown in FIG. 1;
FIG. 6 is a chart showing the weft yarn selecting program; and
FIG. 7 is a diagrammatic side elevation showing a modification of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 6 illustrate an embodiment of the present invention when applied to a weft inserting device mounted to a frame side of a loom. The numeral 1 designates a cam plate secured to a driving shaft 2 and making a half revolution per each revolution of movable loom parts, not shown. The numeral 3 designates a cam lever or driving member adapted for making a reciprocating swinging motion about pin 4 with rotation of cam plate 1. The cam lever 3 has a portion 3a mounting a first solenoid 5 and a latch rod 6 projecting from the surface of the lever portion 3a upon energization of the solenoid 5. The cam lever 3 also has another portion 3b mounting a cam follower 3c which is perpetually urged by a spring 7 clockwise in FIG. 2 and into abutting contact with the cam surface of the cam plate 1. The numeral 8 designates a transmission lever mounted for rotation about pin 4 and urged by a spring 9 to rotate clockwise so that it may be engaged at the lower edge thereof with the latch rod 6. The numeral 10 desigates a stopper of the lever 3.
The numeral 11 designates a change lever or a main nozzle supporting member mounted for swinging about a pin 13 and in the neighborhood of the weft inserting position and biased by a spring 12 to rotate clockwise in FIG. 2. This change lever 11 has a first lever portion 11a connected by a connecting bar 14 to the transmission lever 8, a second lever portion 11b mounting a first main nozzle 15 adapted for inserting weft yarn Y1 supplied from a weft yarn supply unit, not shown, and a second lever portion 11c mounting a second main nozzle 16 adapted for inserting weft yarn Y2 supplied from another weft yarn supply, also not shown. The numeral 17 designates a second solenoid adapted to be energized when the second main nozzle 16 has been shifted to the weft inserting position as shown in FIG. 4. With energization of the second solenoid 17, a holding rod 18 operatively associated therewith is protruded to a position engageable with the lower edge of the first lever portion 11a.
The numeral 19 designates a control unit, such as microcomputer, for supplying command signals the solenoids 5, 17 in accordance with a weft selection program.
It should be noted that fluid supply valve means, not shown, for controlling the fluid supplied to the first and second main nozzles 15, 16 are operated responsive to the movement of the holding rod 18 in such a manner that the fluid is supplied to the second main nozzle 16 or to the first main nozzle 15 depending on whether the holding rod 18 has or has not been projected into the position engaging with the lower edge of the first lever portion 11a.
The operation of the embodiment described above is now described by referring to a weft selecting program shown as an example in FIG. 6.
When the cam follower 3c abuts on a lesser diameter zone of cam plate 1, and the transmission lever 8 is latched by stopper 10, the first main nozzle 15 is held stationarily at the weft inserting position. When the cam follower 3c has shifted to the larger diameter zone of the cam plate 1 with rotation of cam plate 1, the cam lever 3 is rotated counterclockwise in FIG. 2 against the urging force of the spring 7. At this time, the first solenoid 5 is deenergized as shown in FIG. 6 and the latching rod 6 is not projected from the lever portion 3a. Thus, as shown in FIG. 3, while the transmission lever 8 is latched by the stopper 10, and the first main nozzle 15 is held at the weft yarn inserting position, only the cam lever 3 is rotated. During the time that the cam follower 3c travels from a terminal point P of the lesser diameter zone to a terminal point Q of the larger diameter zone of the cam plate 1, that is, during one complete revolution of the movable parts of the loom or one half revolution of the cam plate 1, a length of weft yarn Y1 is impelled from the first main nozzle 15 to complete a first weft inserting operation.
Next, as the cam plate 1 performs the next one half revolution, and the cam follower 3c travels from the terminal point Q of the larger diameter zone to the terminal point P of the lesser diameter zone, the cam lever 3 is returned to its former position, and a next length of weft yarn Y1 is impelled from the first main nozzle 15 to complete a second weft inserting operation. After termination of the second weft inserting operation, a command signal is issued by the control unit 19 in accordance with the weft yarn selecting program so that the first solenoid 5 is energized for projecting the latching rod 6 to the position engageable with the transmission lever 8. As the cam plate 1 is rotated further and the cam follower 3c has shifted from the terminal point P of the lesser diameter zone to the larger diameter zone, cam lever 3 is rotated counterclockwise in FIG. 4. At this time, the transmission lever 8 and the change lever 11, now engaged by the latch rod 6, are rotated counterclockwise with the pins 4, 13 as center, respectively, against the urging force of the springs 9, 12. The second main nozzle 16 is now at the weft inserting position in place of the first main nozzle 15.
At this time, the second solenoid 17 is energized by an operational command from the control unit 19 so that the holding rod 18 is protruded into a position engaging with the change lever 11. An instant later, the first solenoid 5 is deenergized so that the latching rod 6 is withdrawn to a position unengageable with the transission lever 8. As the cam follower 3c travels to the terminal point Q of the large diameter zone, a length of weft yarn Y2 is impelled from the second main nozzle 16 to perform a third weft inserting operation. After termination of this third weft inserting operation, the first solenoid 5 is energized under the operational command from the control unit 19 so that the latching rod 6 is protruded into a position to engage with the transmission lever 8. An instant later, that is, as the cam follower 3c abuts on the terminal point Q of the larger diameter zone, the second solenoid 17 is deenergized so that the holding rod 18 is withdrawn to a position unengageable with the change lever 11. At this time, the change lever 11 and the transmission lever 8 are not held by the holding rod 18, but are held by the latching rod 18. As the cam follower 3c is moved from the terminal point Q of the larger diameter zone into the lesser diameter zone, the transmission lever 8 is rotated clockwise in FIG. 4 with the pin 4 as center, while the transmission lever 8 and the change lever 11 are also rotated counterclockwise with the pins 4, 13 as center until the transmission lever 8 is latched by stopper 10, with the first main nozzle 15 being now at the weft inserting position in place of the second main nozzle 16. At this time, since the transmission lever 8 is rotated in unison with cam lever 3, the lever 8 is not impinged abruptly on the stopper 10, but may be engaged quietly therewith.
During the time that the cam follower 3c is moved to the terminal point P of the lesser diameter zone, the first solenoid 5 is deenergized so that the latching rod 6 is withdrawn to a position enengageable with transmission lever 8. At this time, the next length of weft yarn Y1 is impelled from the first main nozzle 15 to complete fourth weft insertion. After completion of this weft inserting operation, the first solenoid 5 is energized so that the latching rod 6 is protruded to a position engageable with the transmission lever 8. As the cam follower 3c has shifted from the terminal point P of the lesser diameter zone to the larger diameter zone, levers 3, 8 and 11 are rotated counter-clockwise about respective pin 4, 13, as shown in FIG. 4, with the second main nozzle 6 being now at the weft inserting position in place of the first main nozzle 5.
At this time, the second solenoid 17 is energized so that the holding rod 18 is protruded to a position engageable with change lever 11. An instant later, the first solenoid 5 is deenergized so that the latching rod 6 is withdrawn to a position unengageable with transmission lever 8. Thereafter, as the cam plate 1 performs one and a half revolution, that is, as the movable parts of the loom perform approximately three revolutions, the holding rod 18 is kept in the projected position as shown in FIG. 5 so that the second main nozzle 16 is also kept in the weft inserting position. During this time, three successive lengths of weft yarn Y2 are impelled from the second main nozzle 16 to complete fifth, sixth and seventh weft inserting operations. After termination of the seventh weft inserting operation, first solenoid 5 is energized for projecting the latching rod 6 while the second solenoid 17 is deenergized for receding the holding rod 18 to a position unengageable with the change lever 11. As the cam follower 3c has shifted from the larger diameter zone to the lesser diameter zone, transmission lever 8 is engaged quietly with stopper 10. The first main nozzle 15 is now at the weft inserting position in place of second main nozzle 16.
From the foregoing, it will be apparent that, since the swinging reciprocal movement of the cam lever 3 caused by rotation of the cam plate 1 is transmitted to the change lever 11 carrying the main nozzles 15, 16 in a manner determined by the weft yarn selection program, the sequence or pattern of using the main nozzles 15, 16 for inserting the weft yarn may be changed as desired by properly changing the control program and without the necessity of changing mechanical parts.
It should be noted that the present invention is not limited to the foregoing arrangement, but comprises a number of modifications. For instance, the following changes can be made within the scope of the present invention.
(a) The first solenoid 5 and the latching rod 6 in the preceding embodiment may be provided to the transmission lever 8 so that the latching rod 6 may be projected into a position engaging with cam lever 3.
(b) The transmission lever 8 and the connecting bar 14 in the preceding embodiment may be dispensed with provided that the latching rod 8 is directly engaged with the change lever 11.
(c) The cam plate 1 may be changed in profile as shown in FIG. 7 and rotated once per each revolution of the movable loom parts. In this case, the cam follower 3c is abutted with the larger diameter zone 1a of the cam plate 1 slightly before start of the weft inserting operation.
(d) The change lever 11 may be provided with three or more main nozzles and the number of the latch rods 6 and holding rods 18 increased depending on the number of the main nozzles. In this case, the mounting positions of the supplemented latching and holding rods 6, 18 need be selected depending on the distances traversed by the respective main nozzles when moved towards the weft inserting position.
(e) A plurality of change levers each fitted with one main nozzle or two or more main nozzles are provided and each said change lever is operatively connected to a cam plate.
(f) The present invention may be embodied in a weft inserting device provided to a sley, not shown.
From the foregoing, it will be apparent that the arrangement according to the present invention provides an extremely useful and effective weft inserting device for a jet loom by means of which the reciprocal movement of the driving member may be transmitted to the main nozzle change lever in accordance with the weft yarn selection program so that the main nozzles may be placed in readiness for inserting weft yarn at the proper timing and sequence as determined by said selection program.
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In the weft inserting device of the invention, a pair of main nozzles are supported by a change lever and the motion of a cam lever operatively linked with movable loom parts for reciprocation thereby is transmitted to said change lever. The timing of motion transmission and interruption is controlled by a timing control unit. According to a preferred embodiment, the control unit is a microcomputer and the timing setting can be changed by changing the weft yarn selection program stored in the microcomputer.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims priority from Japanese Patent Application No. 2012-140139, filed on Jun. 21, 2012, in the Japanese Patent Office, and Korean Patent Application No. 10-2012-0110091, filed on Oct. 4, 2012, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entireties.
BACKGROUND
[0002] 1. Field
[0003] Apparatuses consistent with exemplary embodiments relate to a working machine including a working head moving along a guide beam.
[0004] 2. Description of the Related Art
[0005] An electronic component mounting apparatus for mounting an electronic component, such as an integrated circuit (IC) chip, on a printed circuit board is an example of a working machine that includes a working head moving along a guide beam. FIG. 1 illustrates an electronic component mounting apparatus of the related art which includes a mounting head 100 as a working head, where the mounting head 100 includes a nozzle. The mounting head 100 is movable in an X-direction along a guide beam, referred to as an X-direction beam 200 . The X-direction beam 200 straddles over a pair of Y-direction beams 300 that are spaced apart from each other in the X-direction and the X-direction beam is installed on the Y-direction beams 300 . The X-direction beam is movable in the Y-direction along the Y-direction beams 300 . As such, the mounting head 100 may freely move in the X-direction and the Y-direction within a horizontal plane according to a combination of the X-direction beam 200 and the Y-direction beam 300 . According to a combined movement in the X-direction and the Y-direction, the mounting head 100 moves to a component supply unit (not shown), picks up an electronic component from the component supply unit by using a nozzle, moves to a predetermined mounting location of a printed circuit board (not shown), and then mounts the electronic component at the predetermined mounting location of the printed board.
[0006] In order to drive the electronic component mounting apparatus, power needs to be supplied to the mounting head 100 or the like. In the related art, for example, in Japanese Patent Publication JP 2008-243839, power is supplied to the mounting head 100 from an external power source by using a cable, and a cableveyor™ 210 is used to move a direct power feeder, such as a cable or a slip ring, within range of the mounting head 100 in the X-direction.
[0007] However, abrasion or disconnection is not completely prevented by using such a power supply method, and when the cableveyor™ is installed to provide power to a mounting head 100 , operational range of the mounting head in an X-Y direction is limited. Thus, even when a plurality of mounting heads are mounted on one X-direction beam to improve mounting efficiency, operational range of each mounting head is not sufficiently obtained, and it is difficult in practice to install the plurality of mounting heads on one X-direction beam.
[0008] Such power supply problems are not limited to the electronic component mounting apparatus and are common to a working machine that includes a working head moving along a guide beam.
SUMMARY
[0009] One or more exemplary embodiments provide a working machine powered in a non-contact manner including a working head moving along a guide beam, wherein power is supplied to the working head without using a direct power feeder.
[0010] According to an aspect of an exemplary embodiment, there is provided a working machine including a guide beam including a power transmitter; at least one working head comprising a power receiver which moves along the guide beam, wherein the power receiver receives power from the power transmitter in a non-contact manner in which the power receiver and the power transmitter are not physically connected, and wherein the working head operates by the received power in the non-contact manner.
[0011] The working head may move in a direction along an extension direction of the guide beam and maintains a uniform distance from the guide beam in a direction perpendicular from the extension direction.
[0012] The non-contact manner includes electric field coupling, wherein the power transmitter comprises a power transmitter electrode, and wherein the power receiver comprises a power receiver electrode facing the power transmitter electrode. The power receiver electrode maintains a uniform distance from the power transmitter electrode in a direction perpendicular to an extension direction of the guide beam.
[0013] The non-contact manner may include electromagnetic induction, wherein the power transmitter comprises a power transmitter coil, and wherein the power receiver comprises a power reception coil facing the power transmitter coil.
[0014] The power reception coil may maintain a uniform distance from the power transmitter coil in a direction perpendicular to an extension direction of the guide beam.
[0015] The at least one working head may include a plurality of the working heads which move along the same guide beam.
[0016] The working head may include a wireless communication unit configured to receive a control signal to operate the working head, and at least one pressure generating unit.
[0017] According to an aspect of another exemplary embodiment, there is provided a working machine including a power transmitter disposed on a guide beam; a power receiver disposed on a working head, wherein the working head moves along the guide beam maintaining a uniform distance between the power transmitter and the power receiver, wherein the power transmitter transmits power to the power receiver wirelessly, and the working head operates by the transmitted power.
[0018] According to an aspect of another exemplary embodiment, there is provided a component moving apparatus including: a guide beam comprising a power transmitter; at least one working head comprising a power receiver and configured to move along the guide beam; wherein the power receiver receives power from the power transmitter in a non-contact manner in which the power receiver and the power transmitter are not physically connected, and wherein the working head operates by the received power in the non-contact manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and/or other aspects will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
[0020] FIG. 1 is a diagram illustrating a structure of a electronic component mounting apparatus of the related art;
[0021] FIG. 2 is a diagram illustrating a basic structure of an electronic component mounting apparatus in a view along a Y-direction according to an exemplary embodiment;
[0022] FIG. 3 is a side view along an X-direction illustrating a structure for supplying power to a mounting head in the electronic component mounting apparatus of FIG. 2 according to an exemplary embodiment;
[0023] FIG. 4 is a circuit diagram equivalent to the structure of FIG. 3 ;
[0024] FIG. 5 is a side view illustrating a structure for supplying power to the mounting head in the electronic component mounting apparatus of FIG. 2 according to another exemplary embodiment;
[0025] FIG. 6 is a cross-sectional view of a positive pressure generating unit according to an exemplary embodiment; and
[0026] FIG. 7 is a cross-sectional view of a negative pressure generating unit according to an exemplary embodiment.
DETAILED DESCRIPTION
[0027] Hereinafter, one or more embodiments will be described in detail with reference to accompanying drawings. Also, in drawings, same reference numerals denote same elements to avoid repetition. An example of a working machine according to an exemplary embodiment will now be described, specifically, an electronic component mounting apparatus.
[0028] FIG. 2 is a diagram illustrating a basic structure of an electronic component mounting apparatus 1 according to an exemplary embodiment. The electronic component mounting apparatus 1 includes a mounting head 10 as a working head. The mounting head 10 picks up an electronic component and mounts the electronic component onto a printed circuit board. One or more nozzles 11 are installed onto the mounting head 10 and are movable in a Z-direction crossing X-and Y-directions, i.e., in an up-and-down direction as shown in FIG. 2 .
[0029] Referring to the electronic component mounting apparatus 1 of FIG. 2 , three mounting heads 10 are installed to an X-direction beam 20 and are movable in an X-direction along the X-direction beam 20 . Each of the three mounting heads 10 may be a rotary type or linear type inclusive of a plurality of nozzles, a type including one nozzle, or a combination of a plurality of mounting head types. Each of the three mounting heads 10 may be of the same or different type and may move freely according to an optimized program while avoiding collision and interference from one another. The X-direction beam 20 is an example of a guide beam according to an exemplary embodiment.
[0030] In FIG. 2 , only one X-direction beam 20 is shown, but alternatively, a pair of the X-direction beams 20 may straddle over the Y-direction beams 30 as shown in FIG. 1 , and one or more mounting heads 10 may be installed to one of the X-direction beams 20 .
[0031] The X-direction beam 20 straddles over a pair of Y-direction beams 30 that are spaced apart from each other in the X-direction and the X-direction beam 20 is installed on the Y-direction beams 30 . The X-direction beam is movable in the Y-direction along the Y-direction beams 30 . As such, one or more of the three mounting heads 10 freely moves in the X-direction and the Y-direction within a horizontal plane according to a combination of the X-direction beam 20 and the Y-direction beam 30 . According to a combined movement in the X-direction and the Y-direction, one or more of the three mounting heads 10 moves to a component supply unit (not shown), picks up an electronic component by using a nozzle 11 , moves to a predetermined mounting location of a printed circuit board (not shown), and then mounts the electronic component at the predetermined mounting location of the printed circuit board.
[0032] FIG. 3 is a diagram illustrating a structure for supplying power to the mounting head 10 according to an exemplary embodiment. As shown in FIG. 3 , the mounting head 10 is installed to the X-direction beam 20 along a length direction (X-direction) of the X-direction beam 20 by using a linear guide 13 installed to a board plate 12 , and is movable in the X-direction. In other words, the mounting head 10 freely moves in the X-direction while maintaining a uniform distance from the X-direction beam 20 .
[0033] In FIG. 3 , electric field coupling is used to supply power to the mounting head 10 . According to the electric field coupling, power is transmitted in a non-contact (wireless) manner by using an electric field generated when a power transmitter electrode and a power receiver electrode approach each other, wherein the power transmitter electrode is installed to a power transmission side and the power receiver electrode is installed to a power reception side.
[0034] In FIGS. 3 and 4 , the X-direction beam 20 is the power transmission side, and the mounting head 10 is the power reception side. That is, a power transmitter is installed to the X-direction beam 20 and a power receiver is installed to the mounting head 10 . A power transmitter electrode 21 is installed to the power transmitter installed to the X-direction beam 20 and a power receiver electrode 14 is installed to the mounting head 10 . Power transmitter electrode 21 is installed to protrude vertically (in a Z-direction as shown in FIG. 3 ) from top and bottom surfaces of the X-direction beam 20 , and the power receiver electrode 14 is installed to protrude vertically (in the Z-direction as shown in FIG. 3 ) from top and bottom surfaces of the board plate 12 of the mounting head 10 so as to face the power transmitter electrode 21 in a Y-direction as shown in FIG. 3 . An equivalent circuit of the power transmission system of FIG. 3 is shown in FIG. 4 . Referring to FIG. 3 and FIG. 4 , in order to drive mounting head 10 , power is transmitted from the power transmitter to the power receiver according to the electric field coupling between the power transmitter electrode 21 and the power receiver electrode 14 .
[0035] FIG. 4 illustrates capacitance C 1 and C 2 formed between the power transmitter electrode 21 of the X-direction beam 20 and the power receiver electrode 14 of the mounting head 10 . The X-direction beam 20 includes a power transmitter, a pair of inductors L 1 and L 2 along with a power source V and impedance Z 0 . One the other hand, the mounting head 10 includes the power receiver and impedance Z 1 .
[0036] Since the mounting head 10 moves in the X-direction while always maintaining a uniform distance from the X-direction beam 20 as described above, a distance between the power transmitter electrode 21 and the power receiver electrode 14 is always constant and may be easily kept to be a minimal distance. The constant and minimal distance may be suitable for transmitting power by using the electric field coupling.
[0037] FIG. 5 is a diagram illustrating a structure for supplying power to the mounting head 10 , according to another exemplary embodiment. In FIG. 5 , electromagnetic induction is used to supply power to the mounting head 10 . A power transmission coil is installed to a power transmission side and a power reception coil is installed to a power reception side, and power is transmitted in a non-contact (wireless) manner via electromagnetic induction.
[0038] In FIG. 5 , the mounting head 10 is installed to the X-direction beam 20 along the length direction (X-direction) by using the linear guide 13 installed to the board plate 12 , and is movable in an X-direction along X-direction beam 20 .
[0039] In FIG. 5 , a power supply rail 22 is installed along the length direction of the X-direction beam 20 , as a power transmitter. Power is supplied to the power supply rail 22 , and a roller 15 moves in the X-direction in synch with movement of the board plate 12 . As roller 15 moves in the X-direction, roller 15 is rotated while maintaining electrical contact with the power supply rail 22 . A power transmission coil 16 is installed to the roller 15 , and a power reception coil 17 is disposed at a location facing the power transmission coil 16 . The power reception coil 17 is installed to the board plate 12 of the mounting head 10 , and power generated via electromagnetic induction with the power transmission coil 16 is supplied to the mounting head 10 .
[0040] As shown in FIG. 3 and FIG. 5 , a power transmitter (the power transmitter electrode 21 and the power supply rail 22 ) is installed to the X-direction beam 20 . A power receiver (the power receiver electrode 14 and the power reception coil 17 ) that receives power in a non-contact (wireless) manner from the power transmitter is installed to the mounting head 10 , and the power received is used to drive the mounting head 10 . Power may thus be supplied to the mounting head 10 without having to install a direct power feeder.
[0041] In addition to power, vacuum suction and compressed air need to be supplied to the mounting head 10 in order to pick up an electronic component and then mount the electronic component on a printed circuit board. In other words, the nozzle 11 of the mounting head 10 uses vacuum suction to pick up the electronic component, and a small amount of compressed air is blown to break the vacuum suction so that the electronic component may be mounted. In an electronic component mounting apparatus of the related art, a negative pressure generating unit for supplying the vacuum suction and a positive pressure generating unit for supplying the compressed air are generally installed external to the mounting head 10 , and the positive pressure generating unit and the negative pressure generating unit are each connected to the mounting head 10 through an air pipe.
[0042] Similarly, a supplied signal is required to control the mounting head 10 . The signal may be supplied via wires in the related art electronic component mounting apparatus, and a control unit and the mounting head 10 are connected via a signal cable. Like a power supply cable, the air pipe and the signal cable are connected to the mounting head 10 by using the cableveyor™ 210 of FIG. 1 . Accordingly, the air pipe and the signal cable should be removed so as not to use the cableveyor™ 210 .
[0043] The signal cable may be removed by installing a wireless communication unit in the mounting head 10 . Wireless communication is a well known technology, and thus details thereof are not described herein.
[0044] The air pipe may be removed by installing a positive pressure generating unit and a negative pressure generating unit inside the mounting head 10 .
[0045] The positive pressure generating unit may be a micro blower 40 shown in FIG. 6 . The micro blower 40 of FIG. 6 includes a vibration plate 41 formed of a flexible film or a flexible thin plate, a piezoelectric element 42 installed to the vibration plate 41 , and a structure 43 forming an air chamber 43 a and an air inflow chamber 43 b with the vibration plate 41 .
[0046] When the vibration plate 41 is vibrated by the piezoelectric element 42 , air in the air inflow chamber 43 b is discharged from a discharge unit 43 c of the structure 43 , with and by air being due to continuously discharged air from the air chamber 43 a . By supplying the air discharged from the discharge unit 43 c to each nozzle 11 of the mounting head 10 , vacuum suction of the nozzle 11 may be broken.
[0047] Meanwhile, the negative pressure generating unit may be formed by using the micro blower 40 described above. An exemplary embodiment of the micro blower 40 is shown in FIG. 7 . A negative pressure generating unit 50 shown in FIG. 7 includes a straight main conduit 51 and a branch conduit 52 . One end of the straight main conduit 51 is connected to the discharge unit 43 c of the micro blower 40 of FIG. 6 , and the other end is open to air. The branch conduit 52 branches from the straight main conduit 51 at a right angle and is connected to each nozzle 11 of the mounting head 10 . When air that is discharged from the micro blower 40 moves inside the straight main conduit 51 , pressure formed inside of the straight main conduit 51 turns negative according to flow speed of the air, and thus pressure inside the branch conduit 52 turns negative. Accordingly, it is possible to supply negative pressure to the nozzle 11 .
[0048] The micro blower 40 of the current exemplary embodiment has dimensions of 20 mm in length, 20 mm in width, and 2 mm in thickness (when excluding the discharge unit 43 c ). Thus, the micro blower 40 can be installed inside of the mounting head 10 . The small size of micro blower 40 , having air discharge pressure of about 1900 Pa and air volume of about 1 L per minute, allows the micro blower 40 to operate as both the positive pressure generating unit and the negative pressure generating unit in the current exemplary embodiment.
[0049] As described above, using a non-contact (wireless) power feeder removes the need for a cableveyor™ 210 when installing the plurality of mounting heads 10 on the X-direction beam 20 as shown in FIG. 2 .
[0050] The exemplary embodiment is not limited to an electronic component mounting apparatus 1 and may be applied to any working machine inclusive of a working head moving along a guide beam, such as, for example, a welding apparatus inclusive of a welding head moving along a guide beam.
[0051] According to one or more exemplary embodiments, since power is transmitted in a non-contact manner, power may be supplied to the working head without abrasion or disconnection. In the case of a plurality of working heads mounted on one guide beam, power feeders will not interfere with one another.
[0052] While exemplary embodiments have been particularly shown and described above, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concept as defined by the following claims.
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There is provided a working machine including a guide beam having a power transmitter; at least one working head comprising a power receiver and configured to move along the guide beam, wherein the power receiver receives power from the power transmitter in a non-contact manner in which the power receiver and the power transmitter are not physically connected, and wherein the working head operates by the received power in the non-contact manner.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 12/246,451 filed Oct. 6, 2008, which is included in its entirety herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates, in general, to a method for fabricating an integrated circuit. More particularly, the present invention relates to a method for fabricating an integrated circuit with an air gap.
[0004] 2. Description of the Prior Art
[0005] Semiconductor manufacturers have been trying to shrink transistor size in integrated circuits (IC) to improve chip performance, which leads to the result that the integrated circuit speed is increased and the device density is also greatly increased. However, under the increased IC speed and the device density, the RC delay becomes the dominant factor.
[0006] To facilitate further improvements, semiconductor IC manufacturers have been driven by the trend to resort to new materials utilized to reduce the RC delay by either lowering the interconnect wire resistance, or by reducing the capacitance of the inter-layer dielectric (ILD). A significant improvement is achieved by replacing the aluminum (Al) interconnects with copper, which has 30% lower resistivity than that of Al. Further advances are facilitated by improving electrical isolation and reducing parasitic capacitance in high density integrated circuits.
[0007] Current attempts to improve electrical isolation and reduce parasitic capacitance in high density integrated circuits involve the implementation of low-k dielectric materials such as FSG, HSQ, SiLK™, FLAREK™. To successfully integrate the low K dielectric materials with conventional semiconductor manufacturing processes, several basic characteristics including low dielectric constant, low surface resistivity (>10 15 Ω), low compressive or weak tensile (>30 MPa), superior mechanical strength, low moisture absorption and high process compatibility are required.
[0008] While the aforesaid materials respectively have a relatively low dielectric constant, they are not normally used in semiconductor manufacturing process due to increased manufacturing complexity and costs, potential reliability problems and low integration between the low-k materials and metals. Therefore, there is a strong need in this industry to provide a method for fabricating an integrated circuit in order to improve the integrated circuit performance.
SUMMARY OF THE INVENTION
[0009] It is one objective of the present invention to provide an improved method for forming an integrated circuit with air gap in order to solve the above-mentioned conventional problems.
[0010] To meet these ends, according to one aspect of the present invention, there is provided a method for fabricating an integrated circuit. A substrate having thereon a first conductive wire and a second conductive wire is provided. A liner layer is formed on the first conductive wire and second conductive wire. An ashable material layer is filled into a space between the first conductive wire and second conductive wire. The ashable material layer is then polished to expose a portion of the liner layer. A cap layer is formed on the ashable material layer and on the exposed liner layer. A through hole is extended into the cap layer to expose a portion of the ashable material layer. Thereafter, the ashable material layer is removed by way of the through hole.
[0011] In one aspect, another embodiment of this invention provides a method for fabricating an integrated circuit, comprising the steps of providing a substrate having thereon a material layer; forming trenches in the material layer; forming damascened wires in the trenches; covering the damascened wires and the material layer with a cap layer; forming a through hole in the cap layer that exposes a portion of the material layer; and removing the material layer thereby forming an air gap between the damascened wires.
[0012] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 to FIG. 8 are schematic, cross-sectional diagrams showing a method for fabricating an integrated circuit in accordance with one preferred embodiment of this invention.
[0014] FIG. 9 to FIG. 14 are schematic, cross-sectional diagrams showing a method for fabricating an integrated circuit in accordance with another embodiment of this invention.
DETAILED DESCRIPTION
[0015] Without the intention of a limitation, the invention will now be described and illustrated with reference to the preferred embodiments of the present invention.
[0016] FIG. 1 to FIG. 8 are schematic, cross-sectional diagrams showing a method for fabricating an integrated circuit in accordance with the preferred embodiment of this invention. As shown in FIG. 1 , a substrate 10 is provided. A first conductive wire 12 a and a second conductive wire 12 b are provided on the substrate 10 . The first conductive wire 12 a is adjacent to the second conductive wire 12 b. For example, a space (S) between the first conductive wire 12 a and the second conductive wire 12 b ranges between 30 nanometers and 500 nanometers. According to this embodiment of the present invention, the first and second conductive wires 12 a and 12 b are both composed of metal such as aluminum, but not limited thereto.
[0017] It is understood that in other embodiments the first and second conductive wires 12 a and 12 b may be composed of copper or aluminum/copper alloys. According to this embodiment of the present invention, the first conductive wire 12 a has an exposed top surface 112 a and exposed sidewalls 114 a, and the second conductive wire 12 b has an exposed top surface 112 b and exposed sidewalls 114 b.
[0018] As shown in FIG. 2 , subsequently, a chemical vapor deposition (CVD) process is carried out to deposit a conformal liner layer 14 on the top surface 112 a and sidewalls 114 a of the first conductive wire 12 a and the top surface 112 b and sidewalls 114 b of the second conductive wire 12 b. The liner layer 14 also covers the substrate 10 .
[0019] According to this embodiment of the present invention, the liner layer 14 preferably comprises silicon oxide or silicon nitride and has thickness of 0-1000 angstroms. The thickness of the liner layer 14 is insufficient to fill the space 13 between the first conductive wire 12 a and the second conductive wire 12 b. In other embodiments, the liner layer 14 may comprise SiO 2 , Si 3 N 4 , SiON, SiC, SiOC, SiCN or any other suitable materials.
[0020] According to the preferred embodiment, the liner layer 14 can protect the first conductive wire 12 a and the second conductive wire 12 b from corrosion. The liner layer 14 also acts as a polishing stop layer during the subsequent chemical mechanical polishing (CMP) process.
[0021] As shown in FIG. 3 , an ashable material layer 16 is formed on the liner layer 14 . The ashable material layer 16 may comprise carbon layer or fluorine-doped carbon layer. According to the preferred embodiment, the ashable material layer 16 is filled into the space 13 between the first conductive wire 12 a and the second conductive wire 12 b. The space 13 may be completely or partially filled with the ashable material layer 16 . In a situation where the space 13 is not filled with the ashable material layer 16 , a void (not shown) may be formed within the space 13 .
[0022] According to the preferred embodiment of this invention, the ashable material layer 16 may be formed by CVD methods such as PECVD method and HDPCVD method, or spin-on deposition (SOD) methods.
[0023] As shown in FIG. 4 , subsequently, a planarization process such as CMP process is performed to polish away a portion of the ashable material layer 16 , thereby exposing the liner layer 14 on the top surface 112 a of the first conductive wire 12 a and the liner layer 14 on the top surface 112 b of the second conductive wire 12 b. As previously mentioned, the liner layer 14 acts as a polishing stop layer during the CMP process. After the CMP process, a top surface of the ashable material layer 16 is substantially coplanar with the exposed surfaces of the liner layer 14 .
[0024] As shown in FIG. 5 , a conventional CVD process is carried out to deposit a cap layer 18 on the ashable material layer 16 and on the exposed surfaces of the liner layer 14 . According to the preferred embodiment of this invention, the cap layer 18 is a silicon oxide layer. However, the cap layer 18 may be a silicon nitride layer or a low-k dielectric layer.
[0025] It is one germane feature of this invention that the ashable material layer 16 in the space 13 must sustain the high temperatures during the CVD deposition of the cap layer 18 . Generally, the temperature employed to deposit the cap layer 18 is about 350° C. In this case, the ashable material layer 16 in the space 13 must sustain at least 350° C. In this regard, some organic materials or photoresist materials are inapplicable to the present invention method.
[0026] As shown in FIG. 6 , a photoresist pattern 20 is formed on the cap layer 18 . The photoresist pattern 20 has an aperture 20 a exposing a portion of the cap layer 18 directly above the space 13 . The method for forming the photoresist pattern 20 may include conventional lithographic process such as photoresist coating, exposure, development and baking.
[0027] As shown in FIG. 7 , thereafter, an etching process such as a dry etching process is performed to etch the cap layer 18 through the aperture 20 a of the photoresist pattern 20 , thereby forming a through hole 18 a in the cap layer 18 . The through hole 18 a exposes a portion of the ashable material layer 16 . The photoresist pattern 20 is then stripped off.
[0028] As shown in FIG. 8 , an ashing process is carried out. For example, oxygen plasma is utilized to completely remove the ashable material layer 16 between the first conductive wire 12 a and the second conductive wire 12 b by way of the through hole 18 a of the cap layer 18 , thereby forming an air gap 30 between the first conductive wire 12 a and the second conductive wire 12 b. Subsequently, a CVD process is performed to form a dielectric layer 32 over the cap layer 18 . The dielectric layer 32 seals the through hole 18 a of the cap layer 18 thereby forming a hermetic air gap 30 . According to the preferred embodiment of this invention, the dielectric layer 32 may be silicon oxide or low-k dielectric materials. In other embodiments, the deposition of the dielectric layer 32 may be implemented concurrently with the aforesaid ashing process.
[0029] The method for fabricating the integrated circuit structure of the present invention has at least the following advantages: (1) The method is completely compatible with current integrated circuit manufacturing processes and no additional investment or development of new equipment is required; (2) The method is cost effective; and (3) The method can provide maximized and unified air gap structure between metal interconnection lines, which is capable of effectively reducing RC delay and improving performance of the integrated circuit device.
[0030] FIG. 9 to FIG. 14 are schematic, cross-sectional diagrams showing a method for fabricating an integrated circuit in accordance with another embodiment of this invention. As shown in FIG. 9 , a substrate 100 is provided. The substrate 100 may be a silicon substrate or any suitable semiconductor substrate known in the art. It is to be understood that the substrate 100 may further comprises circuit elements such as transistors or capacitors and dielectric layers or conductive wires overlying the circuit elements, which are not shown for the sake of simplicity. An ashable material layer 116 is formed on a top surface of the substrate 100 . The ashable material layer 116 may be made of thermal degradable polymers, carbon or fluorine-doped carbon. Some of the typical thermal degradable polymers are disclosed, for example, in U.S. Pub. No. 2007/0149711 A1 assigned to Dow Global Technologies Inc., which should not be used to limit the scope of the invention.
[0031] Subsequently, as shown in FIG. 10 , trenches 116 a are formed in the ashable material layer 116 . Each of the trenches 116 exposes a portion of the underlying substrate 100 . The trenches 116 a may be line-shaped trenches or via holes. It is noteworthy that although only the exemplary single damascene process is shown through FIG. 9 to FIG. 14 , the present invention may be applicable to dual damascene processes or any other types of copper damascene process. After the formation of the trenches 116 a, a diffusion barrier layer 120 such as Ta/TaN or Ti/TiN is deposited on interior surface of the trenches 116 a and on the top surface of the ashable material layer 116 . A low-resistance metal layer 122 such as copper is then deposited on the diffusion barrier layer 120 and fills the trenches 116 a.
[0032] As shown in FIG. 11 , a conventional chemical mechanical polishing (CMP) process is then carried out to polish the low-resistance metal layer 122 until the low-resistance metal layer 122 and the diffusion barrier layer 120 directly above the top surface of the ashable material layer 116 are completely removed. After CMP, the remanent low-resistance metal layer 122 and the diffusion barrier layer 120 damascened in the trenches 116 a constitute damascened interconnection wires 200 . Each of the damascened interconnection wires 200 has a top surface that is substantially flush with the top surface of the ashable material layer 116 .
[0033] Thereafter, a cap layer 124 is deposited on the substrate to cover the damascened interconnection wires 200 and the ashable material layer 116 . Suitable materials for the cap layer 124 include but not limited to SiOC, SiO 2 , Si 3 N 4 , SiCN, SiC.
[0034] As shown in FIG. 12 , a conventional photolithographic process and etching process are performed to form through holes 124 a in the cap layer 124 . The aforesaid photolithographic process may include photoresist coating and baking, exposure and development. Each of the through holes 124 a exposes a portion of the ashable material layer 116 between the damascened interconnection wires 200 and does not expose any of the damascened interconnection wires 200 .
[0035] As shown in FIG. 13 , using the cap layer 124 as a protection layer that protects the top surface of the damascened interconnection wires 200 , an oxygen plasma etching process is performed to etch and remove the ashable material layer 116 , thereby forming air gaps 130 between the damascened interconnection wires 200 .
[0036] As shown in FIG. 14 , subsequently, a CVD process is performed to form a dielectric layer 132 over the cap layer 124 . The dielectric layer 132 seals the through hole 124 a of the cap layer 124 thereby forming a substantially hermetic air gap 130 . According to the preferred embodiment of this invention, the dielectric layer 132 may be silicon oxide or low-k dielectric materials. In other embodiments, the deposition of the dielectric layer 132 may be implemented concurrently with the aforesaid ashing process.
[0037] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A method for fabricating an integrated circuit includes providing a substrate having thereon a material layer; forming trenches in the material layer; forming damascened wires in the trenches; covering the damascened wires and the material layer with a cap layer; forming a through hole in the cap layer that exposes a portion of the material layer; and removing the material layer thereby forming an air gap between the damascened wires.
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FIELD OF THE INVENTION
The present invention pertains to the field of computer memories. More particularly, this invention relates to an electrically erasable and programmable floating gate nonvolatile memory card with automatic power supply configuration.
BACKGROUND OF THE INVENTION
One type of prior nonvolatile memory is the flash erasable and electrically programmable read-only memory ("flash EPROM"). The flash EPROM can be programmed by a user. Once programmed, the entire contents of the flash EPROM can be erased by electrical erasure. The flash EPROM may then be reprogrammed with new data.
Prior art personal computer systems typically employ removable data storage media. One common prior art removable storage medium is a floppy disk. A relatively new prior art storage medium is an integrated circuit-based memory card ("IC memory card").
Prior art flash EPROMs are nonvolatile and reprogrammable, and this has permitted the flash EPROM technology to be used for removable data storage. One such prior art application is the flash EPROM memory card ("flash memory card"). The flash memory card typically includes a number of flash EPROMs. The flash memory card can be erased and programmed electrically.
One category of prior art personal computer systems typically include desk-top computers and another category of prior art personal computer systems typically include laptop computers. Many prior art desk-top computers typically employ a 5 volt power supply and many prior art laptop computers typically employ a 3 volt power supply.
Like the prior art personal computer systems, one type of prior flash memory card is typically designed to be used in the 3 volt power supply environment ("3 volt flash memory card"). Another type of prior flash memory card is typically designed to be used in the 5 volt power supply environment ("5 volt flash memory card"). The 3 volt flash memory card is typically used in the 3 volt power supply prior art personal computers and the 5 volt flash memory card is typically used in the 5 volt power supply prior art personal computers.
One disadvantage associated with such prior flash memory cards is that a 5 volt flash memory card is typically unsuitable for use in a 3 volt power supply personal computer and a 3 volt flash memory card is typically unsuitable for use in a 5 volt power supply personal computer. Mismatching the power supply of a flash memory card with that of a personal computer typically causes damages to data store in the flash memory card and the flash memory card itself. Therefore, before inserting a flash memory card into a personal computer, the user typically needs to know the power supply of the personal computer and to the power supply for the flash memory card. This typically causes inconvenience to the user. When the user does not know or loses track of the power supply of a particular flash memory card, the user typically cannot use that flash memory card.
Another disadvantage associated with the prior flash memory cards is that the prior flash memory cards typically cannot be automatically self-configured to different power supply voltages. Typically, when the power supply of a 5 volt flash memory card accidentally drops from 5 volts to 3 volts, the 5 volt flash memory card typically cannot function properly and the data stored in that flash memory card may be damaged. Likewise, when the power supply of a 3 volt flash memory card accidentally rises from 3 volts to 5 volts, the 3 volt flash memory card typically cannot function properly and the data stored as well as circuitry of the memory card may also be damaged.
SUMMARY AND OBJECTS OF THE INVENTION
One of the objects of the present invention is to provide a reprogrammable nonvolatile memory card that can be used with different power supply voltages.
Another object of the present invention is to provide a reprogrammable nonvolatile memory card that can automatically configure itself to operate at the power supply voltage to which the memory card is currently connected.
Another object of the present invention is to provide a reprogrammable nonvolatile memory card that is fully interchangeable among different power supply voltages.
A nonvolatile memory card includes a power supply input for receiving a device power supply voltage for the memory card and a plurality of memories arranged in an array. Each of the plurality of memories receives the device power supply voltage from the power supply input. Each of the plurality of memories receives a device power supply voltage indication signal that indicates voltage level of the device power supply voltage and configures circuitry within each of the plurality of memories to operate in accordance with the voltage level of the device power supply voltage. A voltage detection circuit is coupled to the power supply input for detecting the voltage level of the device power supply voltage and for generating the device power supply voltage indication signal. A logic is coupled to the voltage detection circuit and each of the plurality of memories for (1) receiving the device power supply voltage indication signal from the voltage detection circuit, (2) applying the device power supply voltage indication signal to each of the plurality of memories such that the circuitry of each of the plurality of memories is configured in accordance with the device power supply voltage indication signal, and (3) supplying data of the nonvolatile memory card with respect to the voltage level of the device power supply voltage to external circuitry.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
FIG. 1 is a perspective view of a flash memory card
FIG. 2 is a block diagram of the flash memory card, which includes a plurality of flash EPROMs, a voltage detection circuit, a power supply V CC control register, and a card information structure (CIS);
FIG. 3 is a block diagram illustrating one embodiment of the card information structure of FIG. 2.
DETAILED DESCRIPTION
FIG. 1 is a perspective view of a flash memory card 10. Inside plastic case 2 of flash memory card 10 there are a plurality of flash EPROMs (not shown in FIG. 1) for storing data at addresses. Flash memory card 10 is inserted to a slot 7 of a personal computer 150 for a memory read or write operation.
Card 10 includes connector 5 located on one side of card 10 to connect card 10 to personal computer 150 when the connector 5 is inserted into slot 7. Card 10 also includes a write protect switch ("WPS") 3.
Computer 150 can be a portable computer, a laptop computer, a desk-top computer, a workstation, a mini computer, a mainframe, or any other type of computer. Computer 150 includes a central processing unit, a memory, and other peripheral devices (all are not shown).
FIG. 2 is a block diagram of flash memory card 10. Flash memory card 10 includes a memory array 11 that includes a plurality of flash EPROMs 12a through 12j and 13a through 13j, each of which includes memory cells that store data at addresses. For one embodiment, memory array 11 includes twenty flash EPROMs.
For other embodiments, memory array 11 may include more or fewer than twenty flash EPROMs. For example, memory array 11 may include two to eighteen flash EPROMs.
For one embodiment, flash memory card 10 can store 40 megabytes ("Mbytes") of data.
For one embodiment, each of flash EPROMs 12a-12j and 13a-13j can store 16 Mbits (i.e., megabits) of data. For other embodiments, each of flash EPROMs 12a-12j and 13a-13j of memory array 11 stores more or fewer than 16 Mbits of data.
Each of flash EPROMs 12a-12j and 13a-13j within memory array 11 includes address inputs A 0 through A 20 and data pins D 0 through D 7 or D 8 through D 15 . Addresses are latched into each of flash EPROMs 12a-12j and 13a-13j via respective address inputs A 0 through A 20 . Each of flash EPROMs 12a-12j includes data pins D 0 through D 7 and each of flash EPROMs 13a-13j includes data pins D 8 through D 15 .
Each of flash EPROMs 12a-12j and 13a-13j includes a write enable input pin WE, an output enable input pin OE, and a chip enable input pin CE. The WE, OE, and CE inputs are each active low. Chip enable CE is the chip select for each of flash EPROMs 12a-12j and 13a-13j and is used for device selection. Output enable OE is the output control for each of flash EPROMs 12a-12j and 13a-13j and is used to gate data from data pins D 0 -D 7 or D 8 -D 15 .
A logical low WE input to a particular flash EPROM of flash EPROMs 11 allows that flash EPROM to be written to if the CE input for that flash EPROM is logically low. Addresses are latched on the falling edge of a write enable pulse. Data is latched on the rising edge of a write enable pulse.
Each of flash EPROMs 12a-12j and 13a-13j also includes a program/erase power supply voltage input V PP1 or V PP2 , a device power supply input V CC , and a V SS input. V PP1 is the program/erase power supply for flash EPROMs 12a-12j and V PP2 is the program/erase power supply for flash EPROMs 13a-13j. For one embodiment, flash EPROMs 11 require V PP1 and V PP2 each to be approximately 12.0 volts. For one embodiment, flash EPROMs 11 require V CC to be approximately 5.0 volts or 3.0 volts. For other embodiments, flash EPROMs 11 allow V CC to be other than 5.0 volts and 3.0 volts. V SS is ground.
Each of flash EPROMs 12a-12j and 13a-13j is capable of operating at different power supply voltages. For one embodiment, each of flash EPROMs 12a-12j and 13a-13j can operate at either the 5 volt power supply or the 3 volt power supply. For another embodiment, each of flash EPROMs 12a-12j and 13a-13j can operate at power supply voltages other than 3 and 5 volts. For alternative embodiments, each of flash EPROMs 12a-12j and 13a-13j can operate at more power supply voltages than 3 and 5 volts. When notified, each of flash EPROMs 12a-12j and 13a-13j can configure its circuitry to operate at the applied power supply voltage. For example, when each of flash EPROMs 12a-12j and 13a-13j is notified that the power supply V CC applied is at 3 volts, each of flash EPROMs 12a-12j and 13a-13j configures its circuitry to operate at the 3 volt power supply. When each of flash EPROMs 12a-12j and 13a-13j is notified that the power supply V CC applied is at 5 volts, each of flash EPROMs 12a-12j and 13a-13j configures its circuitry to operate at the 5 volt power supply.
Each of flash EPROMs 12a-12j and 13a-13j also includes a power supply voltage indication and configuration input PSC. Power supply voltage indication and configuration PSC is the power supply voltage indication and configuration signal for each of flash EPROMs 12a-12j and 13a-13j. For example, when the power supply voltage indication and configuration PSC signal is at logical high level, it indicates or notifies that the power supply V CC for each of flash EPROMs 12a-12j and 13a-13j is 3 volts. When notified by the logical high PSC signal, each of flash EPROMs 12a-12j and 13a-13j configures its circuitry to operate at the 3 volt power supply in accordance with the logical high PSC signal. For example, the read circuit in each of flash EPROMs 12a-12j and 13a-13j changes its timing circuitry to reflect a slower access at 3 volts, and boosts the read voltage applied at the selected word line to 5 volts during reading. Also, the trip point of the power supply voltage sensing and system lockout circuit within each of flash EPROMs 12a-12j and 13a-13j is shifted to be below 3 volts in accordance with the logical high PSC signal.
As a further example, when the power supply voltage indication and configuration signal PSC is at logical low level, it signals to each of flash EPROMs 12a-12j and 13a-13j that the power supply V CC for each of flash EPROMs 12a-12j and 13a-13j is 5 volts and each of flash EPROMs 12a-12j and 13a-13j configures its circuitry to operate at the 5 volt power supply. As shown in FIG. 2, each of flash EPROMs 12a-12j and 13a-13j receives the same PSC signal via line 67.
In absence of a high (i.e., 12 volts) V PP1 or V PP2 voltage applied to a respective flash EPROM, the flash EPROM acts as a read-only memory. The data stored at an address supplied via the A 0 -A 20 address inputs is read from its memory cell array and made available through its data pins D 0 -D 7 or D 8 -D 15 .
When a 12 volt V PP1 or V PP2 voltage is supplied to a respective flash EPROM of flash EPROMs 11, the contents of the flash EPROM can be erased by an erasure operation and the device may then be reprogrammed with new data and codes via a program operation. Each of flash EPROMs 12a-12j and 13a-13j includes circuitry that performs the erasure and programming operations.
Each of flash EPROMs 12a-12j and 13a-13j also includes a power down pin PWD. Power down pin PWD for a flash EPROM is the power down mode control. When the power down PWD signal at one of flash EPROMs 12a-12j and 13a-13j is at logical low level, that flash EPROM enters the power down mode.
Each of flash EPROMs 12a-12j and 13a-13j also includes a ready/busy output pin RY/BY. Ready/busy RY/BY is the ready/busy indicator of each of flash EPROMs 12a-12j and 13a-13j. The RY/BY output of each of flash EPROMs 12a-12j and 13a-13j is active low. A logically high RY/BY output of a flash EPROM indicates a "ready" condition or mode for the flash EPROM (i.e., ready to accept an operation). A logically low RY/BY output indicates a "busy" condition or mode for the flash EPROM (i.e., the write state circuitry is presently busy).
Flash memory card 10 further includes card control logic 21. Card control logic 21 interfaces between card pins of flash memory card 10 and flash EPROMs 11. Card control logic 21 includes card information structure ("CIS") 62 and V CC control register 61 which will be described in more detail below. Card control logic 21 also includes address decoder (not show), data control circuit (not shown), and card control registers (not shown).
Card control logic 21 provides control logic for flash memory card 10. Card control logic 21 receives addresses, data, control signals, power and ground. Card control logic 21 in turn (1) oversees reading, erasing, and programming with respect to flash EPROMs 12a-12j and 13a-13j, (2) oversees the use of electrical power within flash memory card 10, (3) oversees the sending out to the host computer (not shown) card information structure data with respect to flash memory card 10, and (4) oversees the sending out to the host computer status information regarding flash memory card 10.
The card information structure data is stored in card information structure 62. The card information structure data contains details describing the structure of flash memory card 10. The details include the name of the manufacturer of flash memory card 10, the type of flash EPROMs 12a-12j and 13a-13j, and the number of flash EPROMs 12a-12j and 13a-13j.
The card information structure data in card information structure 62 further contains information with respect to different power supply voltages for flash memory card 10. The information contains speed, access time, etc. of flash memory card 10 (i.e., flash EPROMs 12a-12j and 13a-13j) with respect to each of the power supply voltages for flash memory card 10. For example, when flash EPROMs 12a-12j and 13a-13j can operate at a 5 volt power supply and a 3 volt power supply, card information structure 62 will have two supersets, each containing information with respect to the speed, access time, etc. of flash memory card 10 (i.e., flash EPROMs 12a-12j and 13a-13j) at one of the two power supply voltages. When flash EPROMs 12a-12j and 13a-13j can operate at more power supply voltages than 3 and 5 volts, card information structure 62 has more than two supersets, each for one of the power supply voltages. Card information structure 62 supplies its data to the external host computer via bus 70.
The card control registers within card control logic 21 are used to control and report status with respect to flash memory card 10. The external host computer can read and write to the card control registers when proper input signal are applied to card control logic 21.
V CC control register 61 is one of the card control registers within card control logic 21. V CC control register 61 is used to indicate the voltage level of the power supply applied to flash memory card 10 and is used to control the configuration of flash EPROMs 12a-12j and 13a-13j and flash memory card 10 as well to operate in accordance with the card power supply voltage received. V CC register 61 outputs the power supply voltage indication and configuration signal to the PSC pin of each of flash EPROMs 12a-12j and 13a-13j via line 67.
For one embodiment, V CC control register 61 is a one bit register. For other embodiments, V CC control register 61 is a multibit register.
V CC control register 61 receives a device power supply voltage indication signal from a voltage detection circuit 60 via line 68. The device power supply voltage indication signal indicates the voltage level of the card power supply received. Voltage detection circuit 60 will be described in more detail below.
For one embodiment, the output of V CC control register 61 is not applied to card information structure 62 and the card information with respect to different power supply voltages of flash memory card 10 will all be read out when card information structure 62 is accessed. For another embodiment, the output of V CC control register 61 is applied to card information structure 62 to allow only the information with respect to the power supply voltage currently applied to flash memory card 10 to be read out.
Flash memory card 10 includes address input pins A 0 through A 25 and data pins D 0 through D 15 . Both address pins A 0 -A 25 and data pins D 0 -D 15 are coupled to card control logic 21. Addresses applied to pins A 0 -A 25 are latched in card control logic 21. Data pins D 0 -D 15 are employed to input data during memory write cycles, and to output data during memory read cycles. Data pins D 0 -D 15 are active high and float to tri-state OFF when card 10 is deselected or the outputs are disabled.
Flash memory card 10 receives card enable inputs CE 1 and CE 2 and output enable input OE. Card enables CE 1 and CE 2 are chip selects that are used for selecting flash EPROMs 12a-12j and 13a-13j. Card control logic 21 outputs a LCE signal and a UCE signal based on the CE 1 and CE 2 signals received. Output enable OE is the output control of the card and is used to gate data from D 0 -D 15 pins independent of accessed flash EPROM selection. The OE signal is processed by card control logic 21 to become a COE signal which is coupled to the OE pin of each of flash EPROM 12a-12j and 13a-13j via line 37. When the COE is at logical high level, the outputs from all flash EPROMs 12a-12j and 13a-13j are disabled. Data pins D 0 -D 15 of the card are placed in a high impedance state.
Card enable CE 1 is used to enable flash EPROMs 12a-12j. Card enable CE 2 is used to enable flash EPROMs 13a-13j. When both CE 1 and CE 2 are at a logical high level, the card is deselected and the power consumption is reduced to standby level.
Flash memory card 10 also includes a card write enable pin WE. The card write enable WE controls writes to card control logic 21 and flash EPROMs 12a-12j and 13a-13j. When the card WE is at logical high level, data input to flash memory card 10 is disabled. The WE signal is processed by card control logic 21 to become a CWE signal which is coupled to the WE input of each of flash EPROMs 12a-12j and 13a-13j via line 36.
The address decoder of card control logic 21 provides the necessary logic to decode the individual chip enable CE signals needed internally to card 10 to select among flash EPROMs 12a-12j and 13a-13j. Chip enable signal CE for flash EPROMs 12a-12j is provided via LCE signal line 40. Chip enable signal CE for flash EPROMs 13a-13j is supplied via UCE signal line 39. Memory address decoding is linearly mapped in card 10. The memory address is then applied to the selected one of flash EPROMs 12a-12j and 13a-13j via A 0 -A 20 address bus 38.
Flash memory card 10 also includes a card ready/busy output pin RY/BSY. The card ready/busy RY/BSY output indicates whether the card is busy or ready. Card control logic 21 receives the RY/BY output from each of flash EPROMS 12a-12j and 13a-13j via line 42 and then outputs the card ready/busy output RY/BSY to external circuitry.
Flash memory card 10 includes an active low register memory select input pin REG. The REG signal, when logically low, allows card control logic 21 to output the card information structure data from card information structure 62 to the external host computer. In addition, when the REG signal is logically low, the card information structure data stored in card information structure 62 can be updated by a write operation to card control logic 21. Moreover, the logical low REG signal also allows access to the card control registers of card control logic 21. In other words, the REG pin controls the operation to either flash EPROMs 12a-12j and 13a-13j or card control logic 21.
Flash memory card 10 includes two card detection pins CD 1 and CD 2 . The card detection pins CD 1 and CD 2 allow the host computer system to determine if card 10 is properly loaded.
Flash memory card 10 includes a write protection switch 22. Switch 22 disables circuitry (not shown) in card control logic 21 that controls the write enable signal WE to flash EPROMs 12a-12j and 13a-13j. When switch 22 is activated (i.e., a switch knife 30 is connected to the V CC ), the WE output of card control logic 21 is forced high, thus preventing any writes to each of flash EPROMs 12a-12j and 13a-13j.
Flash memory card 10 also includes a write protection output pin WP. When the WP pin is at active high voltage all write operations to the card are disabled. The WP pin reflects the condition of write protection switch 22.
V CC is the card power supply for flash memory card 10 and GND is ground for the card. For one embodiment, card power supply V CC of flash memory card 10 is allowed to be either 3 volts or 5 volts. In this situation, flash memory card 10 will configure each of flash EPROMs 12a-12j and 13a-13j to operate under either the 3 volt power supply or the 5 volt power supply. For other embodiments, card power supply V CC of flash memory card 10 is allowed to be more than 3 and 5 volts or different from 3 and 5 volts.
The device power supply V CC is coupled to a voltage conversion circuit 50. Voltage conversion circuit 50 also receives the REG signal via line 41. Voltage conversion circuit 50 applies the V CC voltage to each of flash EPROMs 12a-12j and 13a-13j. Voltage conversion circuit 50 generates and applies the program/erase voltage V PP to each of flash EPROMs 12a-12j and 13a-13j.
In another embodiment, flash memory card 10 does not include voltage conversion circuit 50. When this occurs, the external host computer needs to supply the device power supply voltage V CC and the program/erase voltage V PP , respectively, to flash memory card 10.
Flash memory card 10 includes a function of automatically configuring itself to the card power supply voltage V CC it currently receives. For example, when the card power supply voltage V CC applied to flash memory card 10 is approximately 3 volts, flash memory card 10 configures itself to be a 3 volt flash memory card. When the card power supply voltage V CC applied to flash memory card 10 is approximately 5 volts, flash memory card 10 confirms itself to be a 5 volt flash memory card. This function of flash memory card 10 is achieved by power supply configurable flash EPROMs 12a-12j and 13a-13j, V CC control register 61, and voltage detection circuit 60. The function will be described in more detail below.
In addition, card information structure 62 stores parameters of flash memory card 10 with respect to different power supply voltages. When accessed, card information structure 62 supplies those parameters to the external host computer such that the external host computer knows that flash memory card 10 is a power supply configurable flash memory card. Moreover, the external host computer also learns the power supply voltages under which flash memory card 10 can be configured to operate.
As described above, flash memory card 10 includes voltage detection circuit 60. Voltage detection circuit 60 receives the card power supply voltage V CC . Voltage detection circuit 60 detects the voltage level of the card power supply voltage V CC and generates the device power supply voltage indication signal to V CC control register 61 via line 68. Voltage detection circuit 60 generates the device power supply voltage indication signal based on the voltage level applied at the power supply V CC pin of flash memory card 10. For example, when the card power supply voltage V CC is at approximately 3 volts, voltage detection circuit 60 generates a logical high signal to V CC control register 61 via line 68. When the card power supply voltage V CC is at approximately 5 volts, voltage detection circuit 60 generates a logical low signal to V CC control register 61 via line 68.
For one embodiment, voltage detection circuit 60 is a SEIKO voltage sensing circuit (Part No. S-80740SL-A4-TX) manufactured by SEIKO Instruments, Inc. of Japan. For alternative embodiments, voltage detection circuit 60 can be other known voltage sensing circuits.
V CC control register 61 then receives the device power supply voltage indication signal via line 68 and stores the signal. V CC control register 61 then outputs the device power supply voltage indication and configuration signal to the PSC pin of each of flash EPROMs 12a-12j and 13a-13j to configure each of flash EPROMs 12a-12j and 13a-13j to operate at the card power supply voltage applied at the V CC pin of flash memory card 10. V CC control register 61 outputs the device power supply voltage indication and configuration signal in accordance with the device power supply voltage indication signal received from voltage detection circuit 60. For example, when the device power supply voltage indication signal indicates that the card power supply V CC is approximately 5 volts, V CC control register 61 outputs a 5 volt device power supply voltage indication and configuration signal accordingly to notify each of flash EPROMs 12a-12j and 13a-13j that the device power supply V CC is at 5 volts and to cause each of flash EPROMs 12a-12j and 13a-13j to be configured to operate at the 5 volt power supply. When the device power supply voltage indication signal indicates that the card power supply voltage V CC is approximately 3 volts, V CC control register 61 generates a 3 volt device power supply voltage indication and configuration signal accordingly to notify each of flash EPROMs 12a-12j and 13a-13j that the device power supply V CC is at 3 volts and to cause each of flash EPROMs 12a-12j and 13a-13j to be configured to operate at the 3 volt power supply. Therefore, flash memory card 10 obtains the automatic power supply configuration function and can be used in different power supply systems.
As described above, card information structure 62 stores parameters of flash memory card 10 with respect to different power supply voltages. When accessed, card information structure 62 supplies these parameters. As is also described above, there are two embodiments of reading these parameters. For one embodiment, the parameters with respect to all different power supply voltages are read out of card information structure 62 when accessed such that the external host computer knows that flash memory card 10 has the power supply configuration function and the supply voltage configuration range of flash memory card 10. The external host computer then has the option to select the power supply voltage for flash memory card 10 and the entire system. For this embodiment, the output of V CC control register 61 is not applied to card information structure 62.
For another embodiment, the device power supply voltage indication and configuration signal from V CC control register 61 is applied to card information structure 62 to selectively cause the parameters with respect to the particular device power supply V CC currently applied at the V CC pin of flash memory card 10 to be read out. FIG. 3 illustrates this embodiment, which will be described in more detail below.
As shown in FIG. 3, card information structure 62 includes a first card information structure 62a and a second card information structure 62b, each storing a set of parameters of flash memory card 10 with respect to one of two device power supply voltages. A multiplexer 100 is provided to selectively couple data in one of first and second card information structures 62a-62b to the external host computer under the control of the device power supply voltage indication and configuration signal from V CC control register 61 (FIG. 2). In this case, the external host computer, however, does not know that flash memory card 10 has the automatic power supply configuration function.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
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A nonvolatile memory card includes a power supply input for receiving a device power supply voltage for the memory card and a plurality of memories arranged in an array. Each of the plurality of memories receives the device power supply voltage from the power supply input. Each of the plurality of memories receives a device power supply voltage indication signal that indicates voltage level of the device power supply voltage and configures circuitry within each of the plurality of memories to operate in accordance with the voltage level of the device power supply voltage. A voltage detection circuit is coupled to the power supply input for detecting the voltage level of the device power supply voltage and for generating the device power supply voltage indication signal. A logic is coupled to the voltage detection circuit and each of the plurality of memories for (1) receiving the device power supply voltage indication signal from the voltage detection circuit, (2) applying the device power supply voltage indication signal to each of the plurality of memories such that the circuitry of each of the plurality of memories is configured in accordance with the device power supply voltage indication signal, and (3) supplying data of the nonvolatile memory card with respect to the voltage level of the device power supply voltage to external circuitry.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[[0001]] The United States Government has rights in this invention pursuant to Contract No. DE-AC05-00OR22725 between the United States Department of Energy and UT-Battelle, LLC.
FIELD OF THE INVENTION
[0002] The invention relates to beam profile scanners used with high and low energy ion, electron and neutral beams. More particularly, it relates to scanners that produce one pair of mutually perpendicular scan profiles of the beam. The scanner of this invention produces not one but two pairs of mutually perpendicular scan profiles, with each pair of scan profiles obtained at a different position along the beam axis.
BACKGROUND OF THE INVENTION
[0003] Rotating wire scanners are used at most accelerator facilities to monitor ion and neutral particle beams in real time, and they are also used to tune the beams.
[0004] A popular scanner is the National Electrostatic Corporation (NEC) Model BPM-80 Beam Profile Monitor. It uses a single helically-shaped wire probe which is rotated in and out of the beam to give a pair of scan profiles, one horizontal and one vertical. The scanner produces an electrical signal which is proportional to the line-integrated horizontal and vertical profiles of the beam. The horizontal and vertical profiles are viewed in real time on an oscilloscope and provide a composite profile of the beam. Alternatively or additionally, the profiles can be digitized for a more quantitative analysis of the beam.
[0005] The Model BPM-80 scanner uses a single helical wire mounted at one end of a two-inch bar. Scan profiles are produced by collecting the electrons emitted from the wire as it passes through the beam. The center of the bar is attached to a rotatable shaft. The bar is oriented to the beamline such that as the bar rotates, the wire is moved in and out of the beam, producing a horizontal and then a vertical scan of the beam. In the Model BPM-80, the horizontal profile of the beam is taken a distance along the beamline of about 2 inches from the vertical profile, as fixed by the length of the two-inch bar.
[0006] One disadvantage of the separation between the horizontal and vertical scan measurements is that the efficiency of electron collection from the rotating wire can be different at the two different positions along the beam. Thus, in the conventional wire scanner, this difference leads to horizontal and vertical profiles which are not normalized to each other. Another disadvantage, which can be very serious for low energy beam applications, is that the beam can change significantly over the 2-inch distance between where the horizontal and vertical profiles are taken. This results in an inaccurate composite profile of converging or diverging beams.
[0007] In this invention, we mount two helical wires on a rotating bar so that the two wires are moved in and out of the beam. This produces two pairs of horizontal and vertical profiles. Due to the manner in which we mount the two wire probes on the bar, one pair of horizontal and vertical profiles is correlated to one position along the beam axis, and the other pair of horizontal and vertical profiles is correlated to a different position along the beam axis. The two pairs of profiles can be used to measure the beam divergence and quality. Our simple modification to a rotating wire scanner provides more accurate beam profiles at two different positions along the beam, providing a measurement of the beam divergence and quality in a single compact device.
REFERENCES
[0008]
1. “Beam Profile Monitors”, Product Bulletin, National Electrostatics Corporation, May 1996, 3 pages.
2. U.S. Pat. No. 3,789,298, issued Jan. 29, 1974, “Beam Scanner”, R. G. Herb.
3. U.S. Pat. No. 4,878,014, issued Oct. 31, 1989, “Ion Beam Profile Scanner Having Symmetric Detector Surface to Minimize Capacitance Noise”, M. L. Simpson.
OBJECTS OF THE INVENTION
[0011] It is a first object of this invention to add a second helical wire probe to a helical wire beam profile scanner such that the two helical wire probes produce two pairs of horizontal and vertical profiles in a single 360 degree scan of the beam.
[0012] Another object of the invention is to minimize electron collection efficiency errors over beam profile scanners that obtain a single pair of mutually perpendicular beam profiles, but are incapable of obtaining them at same position along the beam axis.
[0013] A further object of the invention is to provide two pairs of horizontal and vertical beam profiles at two different positions along the beam axis, allowing the measurement of the beam divergence and quality in a single compact beam profile monitor.
BRIEF SUMMARY OF THE INVENTION
[0014] In one embodiment, an energetic particle beam profile scanner has a probe constructed of a material that emits electrons when struck by the particle beam, a detection means for detecting the electrons emitted from the probe, and drive means for passing the probe through the particle beam at first and second positions along the particle beam axis. The probe provides two mutually perpendicular scans of the particle beam. The profile scanner further comprises a second probe constructed of a material that emits electrons when struck by the particle beam, the detection means is capable of detecting the electrons emitted from the second probe, and the drive means is capable of passing the second probe through the particle beam at the first and second positions along the particle beam axis. The second probe provides two additional mutually perpendicular scans of the particle beam, such that two mutually perpendicular beam scans are obtained at the first position along the particle beam axis, and two mutually perpendicular beam scans are obtained at the second position along the particle beam axis.
[0015] In a further embodiment of the above described particle beam profile scanner, the probe and second probe are mounted spaced apart on the drive means.
[0016] In another embodiment of the above described particle beam profile scanner, the probe and the second probe are jointly mounted on the drive means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates the operation of a conventional rotating wire scanner, as typified in the NEC Model BPM-80. FIG. 1 a shows the rotation of the single wire through a beam traveling in the +z direction. FIG. 1 b shows the signal (electrons emitted from the wire) as the wire is rotated, scanning vertically through the beam at z 1 and then horizontally at z 2 .
[0018] FIG. 2 illustrates a simple modification to the NEC scanner in accordance with our invention. FIG. 2 a shows the rotation of two wires through the beam which is traveling in the +z direction. FIG. 2 b shows the signal (electrons emitted from the wire) as the two wires are rotated into the beam, scanning the beam horizontally at z 1 , vertically at z 1 , vertically at z 2 and then horizontally at z 2 .
[0019] FIG. 3 illustrates a recent dual wire scanner as typified by the NEC Beam Profile Monitor Model BPM280. The two wires mounted at the end of the mounting bar ( FIG. 3 a ) provide the horizontal and vertical scans shown in FIG. 3 b.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 illustrates the principle of operation of a commercially available rotating wire scanner as typified in the NEC Model BPM-80. As described in the NEC manual, a single wire ( 17 ) formed into a 45° helix is rotated about the axis of the helix with the axis inclined at 45° with respect to the vertical in a plane (XY) perpendicular to the direction of the beam. The wire is mounted on a bar 16 as illustrated in FIG. 1 a . The unattached end of the wire is directed toward the center and goes into the plane of the paper. The bar is rotated counter-clockwise as viewed from above the rotation axis. Every full cycle of rotation (360°) results in the wire passing through the beam in two orthogonal directions (this can not be seen easily from the sketch due to the three dimensional aspect of the motion). The electrons emitted from the wire each time it passes through the beam is collected and the resultant signal (see FIG. 1 b ) corresponds to the vertical profile at z 1 and the horizontal profile at z 2 . During the vertical scan the wire passes through the beam from −y to y and the sides of the resultant vertical profile are labeled by the corresponding − or +. During the horizontal scan the wire passes through the beam from −x to +x and the sides of the resultant horizontal profile are also labeled (see FIG. 1 b ). In this illustration the beam which is traveling along the +z direction is centered on the z axis and the 0° angle of rotation is set to when the mounting bar is parallel to the z axis, as shown in FIG. 1 a . The NEC scanner produces electronic fiducials (not shown) to denote the beginning of a scan, the center of the vertical scan, and the center of the horizontal scan, which in this illustration, are at 135° and 315° in the rotation.
[0021] The problems with rotating wire scanners of the above type are that the x and y profiles are measured at two different locations, z 1 and z 2 . This can lead to inaccuracies due to: 1. the efficiency of measuring the electron signal at z 1 and z 2 can be different which results in a different normalization for each profile. 2. The beam can change as a function of z (especially for low energy beams) resulting in an x and y profile which does not accurately reflect the profiles of the beam at any position. This makes the profiles hard to interpret. For example, in FIG. 1 the different profiles shown at z 1 and z 2 seem to indicate that the beam has a narrower vertical profile than horizontal but this interpretation would complicated by a beam, e.g., which is divergent, increasing in width from z 1 to z 2 .
[0022] In the present invention, illustrated in FIG. 2 , we add a second helix shaped wire 18 at the other end of the bar 16 oriented as shown. (The unattached end of both wires is directed toward the center and goes into the paper. In the plane perpendicular to the mounting bar, the two wires 17 , 18 are a mirror image of each other.) Since only one of the wires actually passes through the beam every 90° of rotation, the signals from the different wires do not interfere with each other. The additional wire 18 results in two additional profiles, i.e., a horizontal profile at z 1 and a vertical profile at z 2 . The two wires give orthogonal scans (both x and y) of the beam at each of the locations z 1 and z 2 during each 360° rotation. Horizontally, the additional wire passes through the beam from +x to −x and vertically from +y to −y and is so labeled in FIG. 2 b . For a beam centered on the z axis, the horizontal profile at z 1 is centered at 45° into the rotation, the vertical profile at z 1 is centered at 135° into the rotation, the vertical profile at z 2 is centered at 225° into the rotation, and the horizontal profile at z 2 is centered at 315° into the rotation.
[0023] In the operation of the invention, as in the original NEC scanner, electrons emitted from the wire 18 are collected in a cylindrical shroud and fed into a current amplifier. When the output of the amplifier is fed into an oscilloscope the signal can be displayed as a function of time. By triggering on the electronic fiducials also supplied by the NEC scanner, one may view the profiles just as shown in FIG. 2 b with the angle of rotation replaced by a time axis. In the illustration of FIG. 2 , the first two peaks give the vertical and horizontal beam profiles at z 1 . At z 1 the beam is scanned horizontally from +x to −x or right to left as viewed into the beam. At z 1 the beam is scanned vertically from bottom to top. The last two profiles give the horizontal and vertical profiles at z 2 where vertically the beam is scanned top to bottom and horizontally left to right. Comparing the profiles at z 1 and z 2 it is clear that the beam in this illustration is divergent, with the horizontal and vertical profiles identical at each position. This information is not obtainable from a single wire scanner. Using an oscilloscope, the profiles of the beams can be viewed in “real time” as one tunes the beam. For a more detailed analysis of the beam profiles, the signal can be digitized as a function of time and then fed into a computer. For easier analysis of any offsets or non-symmetric beams, once digitized, the horizontal and vertical profiles can be displayed with the same orientation, i.e., left to right, or bottom to top.
[0024] Our modification provides a more accurate profile of the beam since, for the first time, horizontal and vertical profiles are obtained at the same position in the beam, and thus can be directly compared to each other. These profiles are more accurate than with the prior scanner because each pair of horizontal and vertical profiles are measured at the same position and have the same electron collection efficiency. For low energy beams, where the profile of the beam can change within a relatively short distance, the two pairs of horizontal and vertical profiles are inherently more accurate, and can be used to measure the divergence and quality of the beam.
[0025] FIG. 3 illustrates a recent dual wire scanner, as typified by the NEC Model BPM280. A second helix shaped wire 19 is added to the same end of the bar 16 as the first wire 17 , however with the unattached end of the wire extending out of the paper rather than into the paper like the “original” first wire. The actual mounting of the wire is not significant as long as the wires are not in the beam at the same time. The wires perform scans as the bar 16 is rotated. The wires are mounted in an opposite orientation such that the additional wire does not give identical scans as the first wire. FIG. 3 b shows the beam profiles from the Model BPM280, showing the same information as our modification to the original NEC profile monitor.
[0026] While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be prepared therein without departing from the scope of the inventions defined by the appended claims.
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A widely used scanner device that rotates a single helically shaped wire probe in and out of a particle beam at different beamline positions to give a pair of mutually perpendicular beam profiles is modified by the addition of a second wire probe. As a result, a pair of mutually perpendicular beam profiles is obtained at a first beamline position, and a second pair of mutually perpendicular beam profiles is obtained at a second beamline position. The simple modification not only provides more accurate beam profiles, but also provides a measurement of the beam divergence and quality in a single compact device.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates, generally, to an injection molding machine, and more particularly, but not exclusively, the invention relates to three level stack mold injection molding machine.
[0003] 2. Background Information
[0004] The state of the art includes U.S. Pat. No. 5,707,666 that provides a four level mold having linkage for moving the molds that is capable of moving the molds simultaneously and in unison so that the molds open and close together. The linkage would not permit the use of a side entry robot nor does it show open and easy access through the top of the machine.
[0005] U.S. Pat. No. 5,518,387 describes a swing arm device for removing parts from a mold. The motion of the swing arm device is synchronized with the opening and closing of the mold to speed up part retrieval.
[0006] U.S. Pat. No. 5,185,119 shows a stack mold in Tandem configuration with cores aligned the same way. In this machine the mold is operated on alternate cycles so each side opens sequentially rather than simultaneously.
[0007] U.S. Pat. Nos. 6,027,681 and 6,099,784 describe a stack mold that has unequal strokes so that different parts can be molded in the adjacent molds.
[0008] U.S. Pat. No. 6,155,811 describes a two level mold that is mounted on linear bearings. This is the type of machine that has been modified by the present invention to provide a three level stack mold in the space occupied by the two level stack mold described in this patent.
[0009] U.S. Pat. Nos. 5,908,597 and 6,036,472 describe multiple stack mold machines that use rack and pinion devices to open and close the mold and includes part ejection means that is operated independently of the rack and pinion devices.
[0010] An article on page 14 of the September, 1991 issue of Plastics World describes a mold change system that includes self-locating/leveling mold guide slots.
[0011] An article by P. Glorio of Incoe Corp. published in ANTEC '88, pages 255 to 258 describes the development of quick mold change systems including systems that use hydraulically actuated wedge-lock clamps.
[0012] U.S. Pat. No. 4,473,346 describes a single level molding system where the molding dies are insertable and removable in either the horizontal or vertical direction.
[0013] U.S. Pat. No. 4,500,274 describes a quick-change mold system that includes adapter plates provided with service fittings that interconnect and disconnect upon insertion and removal of the molds together with the adapter plates.
[0014] U.S. Pat. No. 4,500,275 describes a quick-change mold system that includes a locator clamp for facilitating the insertion and removal of a mold from a molding machine
[0015] U.S. Pat. No. 4,568,263 describes the use of locator wedge clamp assemblies mounted on and extending from the platens
[0016] U.S. Pat. No. 5,096,404 describes the use of rollers and guide rails for aligning a mold press in a vertical plane above the injection molding machine.
[0017] U.S. Pat. No. 5,096,405 describes a mounting plate attachable to a molding machine platen. The mounting plate has a plurality of retention slots with hydraulically actuated clamps in the slots. Actuation of the clamps presses a mold part toward the platen in an adjusted position.
[0018] With the cost of injection molding machines and the competitive pricing of products made thereon, it is essential that the machine be as productive as possible. In the case where the machine must be capable of making a number of different parts, this requires that mold changes be quick and inexpensive. It is also cost effective to minimize the space requirements of the machine. In addition, it is essential that parts be removed from the molds as quickly as possible so the cycle time of the machine can be as short as possible. It is also advantageous to provide a machine that requires only a single set of hot runner plates for all moldsets usable on the machine.
[0019] The present invention provides an injection molding machine that enables mold changes to be made quickly and easily, provides robot accessibility to the parts that may be of a variety of heights without modifying the space requirements of the mold and allows a three level stack mold for high profile parts to be placed in space that was previously fully occupied by a two level stack mold.
[0020] The invention is achieved by creating a three level stack mold that provides open access to the molds from all sides when the molds are open. Side access is provided by designing a linkage for the stack mold that surrounds the mold opening but does not cross it when the molds are open. Moving all physical connections such as water and electrical lines to the side edges of the mold provides access through the top and bottom. To avoid any electrical faults caused by water leaks from occurring, the electrical connections are made at the top of the mold and the water connections at the lower point of the mold. Air connections are also provided at the top of the machine to avoid or minimize contamination of the air lines by a failure in the water supply system.
[0021] When the molds need to be changed, the mold is closed and each cavity plate is latched to its respective core plate. The mold is then opened and each moldset of a cavity plate and a core plate is removed from the machine as a single unit along guides. When the cavity and core plate moldset is fully removed, a new moldset of a cavity plate and a core plate is inserted into the mold and guided by the same grooves. The grooves guide the core plate so that it is slightly separated from the platen until it is very near its home position. When it reaches this position a wedge surface forces the core plate against the platen and automatically locks it into position on the platen. At the same time the air and water connections automatically connect to the core plate by automatic docking mechanisms. When the core plate is in position, the mold is closed and the cavity plate is disconnected from the core plate and firmly attached to the hot runner plate.
[0022] The invention also provides a machine in which all three moldsets in the three level stack mold are oriented in the same direction. This enables uniform robot actuation for all three moldsets without the need to reorientate molded parts. This further simplifies the retrieval of molded parts.
[0023] With this configuration, the robot can be located in the same position for all parts and enter between the cavity and core faces without interference with either face. The linkage assembly surrounds the mold opening when the mold is open and eliminates the need for robot adjustment when the molds are changed. This also provides weight distribution and manufacturing benefits.
SUMMARY OF THE INVENTION
[0024] The present invention provides a method of loading a moldset having a core plate and a cavity plate into an injection molding machine. The method preferably comprises the steps of latching a cavity plate to a core plate using a removable latch, guiding the core plate into an open mold along a face in the mold while maintaining separation between the face and the core plate and maintaining the cavity plate spaced from hot runner nozzles in a hot runner in the mold, closing the mold to engage the cavity plate with the hot runner nozzles, securing the cavity plate to the hot runner, removing the latch between the cavity plate and the core plate; and opening the mold. The method may further include step of bolting the cavity plate to the hot runner. The face may be a face of a movable platen or a back surface of a hot runner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which:
[0026] FIG. 1 is a rear perspective view of the injection-molding machine with the mold closed.
[0027] FIG. 2 is a rear perspective view of the injection-molding machine with the mold open.
[0028] FIG. 3 is a rear perspective view of the injection-molding machine having the three hot runners ready to be loaded into the machine.
[0029] FIG. 4 is a rear perspective view of the injection-molding machine with the three hot runners mounted in the machine and the moldsets in position to be loaded into the machine.
[0030] FIG. 5 is a second rear perspective view of the machine with the moldsets in position to be loaded into the machine.
[0031] FIG. 6 is a rear side view of a three level stack mold injection-molding machine with the mold open.
[0032] FIG. 7 is a rear perspective view of a three level stack mold machine with the mold open.
[0033] FIG. 8 is a schematic side view of a linkage assembly for the front of a three level stack mold showing the assembly when the mold is open.
[0034] FIG. 9 is a schematic side view of the linkage assembly for the front of the machine showing the linkage when the mold is open and when the mold is closed.
[0035] FIG. 10 is a perspective view of the mold for a three level stack-molding machine in a partially assembled condition.
[0036] FIG. 11 is a perspective view of a portion of the guide assembly for the core plate.
[0037] FIG. 12 is a perspective view of the guide assembly with a core plate entering the guide assembly.
[0038] FIG. 13 is a bottom perspective view of the guide assembly and core plate.
[0039] FIG. 14 is a perspective view of the movable platen with core plate guides.
[0040] FIG. 15 is a partial perspective view of a movable platen with a core plate fully engaged with the platen.
[0041] FIG. 16 is a bottom perspective view of the molding machine.
[0042] FIG. 17 is a perspective view of a moldset partially loaded into a machine.
[0043] FIG. 18 is a perspective view of a core plate with guides and a core plate separation block.
[0044] FIG. 19 is an enlarged view of a part of the core plate and the core plate separation block.
[0045] FIG. 20 is side view of the core plate and core plate separation block.
[0046] FIG. 21 is a perspective view of the core plate and core plate separation block.
[0047] FIG. 22 is a perspective view of a dial indicator device for indicating proper positioning of the core plate.
[0048] FIG. 23 is a partially cut-away view of a guide with the dial indicator.
[0049] FIG. 24 is a perspective view of the water manifold mounted on a carrier.
[0050] FIG. 25 is a perspective view of the two carrier assemblies with manifolds and hot runners.
DETAILED DESCRIPTION
[0051] As shown in FIGS. 1 and 2 , the injection-molding machine 10 includes a machine frame 12 and a stationary platen 14 supporting a fixed hot runner 30 . Column housing 20 is connected to the molding machine 10 at clamp block 16 . Clamp column 22 clamps the moldsets 24 , 26 and 28 closed during an injection cycle of the molding machine 10 . Moldsets 26 and 28 with their associated hot runners 33 and 34 are mounted on carriers 70 . Movable platen 32 and carriers 70 have rollers 128 that travel on frame 12 . A stroke cylinder is fixed inside the column housing 20 and drives the clamp column 22 to stroke the movable platen 32 . Stroking of the platen 32 drives the linkage assembly 38 to open and close the moldsets 24 , 26 and 28 . The four tiebars 18 are tensioned by the operation of the clamp piston inside clamp block 16 .
[0052] Mold cavity plates 40 , 42 and 44 are mounted on fixed hot runner 30 and movable hot runners 33 and 34 , respectively. Mold core plate 52 is mounted on movable platen 32 and core plates 48 and 50 are mounted on movable hot runners 33 and 34 . With this configuration, all the mold cores face in the same direction. This enables any take out robots to be orientated in a single direction so the ejection and removal of molded parts is simplified. This also allows each of the two central moving sections of the three level stack mold machine to be identical to one another. This provides manufacturing benefits as only a single design is required. Furthermore, as each section is identical, a more balanced weight distribution is maintained within the machine.
[0053] Water service lines 62 to the machine 10 are arranged inside of the legs of the machine 10 . The electrical lines 54 and 56 are shown connected to movable hot runners 33 and 34 over flexible cables joined to brackets 58 and 60 . Flexible water lines 62 are similarly connected to the underside of water manifolds 120 . The service connections will be fully described hereinafter.
[0054] FIG. 3 shows the unassembled machine with the fixed hot runner 30 and the movable hot runners 33 and 34 poised above the machine ready to be loaded onto the machine. Of course, in actual operation, only one of the hot runners at a time would be in position to be loaded onto the machine.
[0055] Fixed hot runner 30 is lowered onto the machine and bolted by bolts 64 to stationary platen 14 . The fixed hot runner 30 is supplied with water connection hoses from the machine to cool hot runner 30 and also provide a water circuit to the cavity plate 40 . However, movable hot runners 33 and 34 need to be guided onto the machine frame. Key slots 65 and 66 engage keys 68 on carriers 70 . The water connections or nipples 118 protruding from the service manifolds 120 engage female fittings on the base of hot runners 33 and 34 to provide a secure water supply to the hot runners 33 and 34 .
[0056] FIGS. 4 and 5 show the machine 10 with the movable platen 32 , movable hot runners 33 and 34 and fixed hot runner 30 installed and the moldsets 24 , 26 and 28 positioned over the machine ready to be loaded into the machine 10 . Each core plate in each moldset 24 , 26 and 28 has a guide slot 74 . Each guide slot 74 engages a guide bar 75 on the movable platen 32 or one of the movable hot runners 33 or 34 .
[0057] In the embodiment shown in the Figures, a central sprue bar 76 extends through the moldset 24 . To enable the moldset 24 to be loaded into the machine 10 , slots 78 and 80 are provided in the core plate 48 and cavity plate 40 of moldset 24 .
[0058] The guide slots 74 on each side of the core plate include core plate separation blocks 140 and 142 . The operation of these separation blocks 140 and 142 will be more fully described hereinafter.
[0059] FIGS. 6 to 9 illustrate the construction and operation of the linkage assembly for moving the mold between the open and closed positions. There are two assemblies 38 on the machine. The first assembly 38 shown on the back of the machine 10 in FIGS. 6 and 7 has an anchor point 84 at the base of stationary platen 14 for the short pivoting arm 86 . A second short pivoting arm 88 is connected to anchor point 90 near the top of movable platen 32 . Extending arms 92 and 94 are pivotably connected to carriers 70 at the mid-point of the carriers 70 . The lower end of arm 92 is pivotably connected to arm 86 and the upper end of arm 94 is pivotably connected to arm 88 . Two curved or L-shaped arms 96 and 98 connect the arms 92 and 94 together.
[0060] The lengths of the linking arms 86 , 88 , 92 , 94 , 96 and 98 are adjusted so that the moldsets 24 , 26 and 28 open and close simultaneously and the linking arms 86 , 88 , 92 , 94 , 96 and 98 do not interfere with side access to the open mold. In the present embodiment, the lower portion 92 a of arm 92 is longer than the upper portion 92 b . For arm 94 , the upper portion 94 b is longer than the lower portion 94 a . The arms 96 and 98 are curved to ensure that they do not extend across the access to the cores and cavities when the mold is open.
[0061] The linkage assembly 38 at the front of the machine is the reverse of the assembly 38 on the back of the machine. To emphasize the similarities between the two assemblies, similar elements have been designated with a prime. As shown in FIGS. 8 and 9 , arm 86 ′ is connected to an upper anchor point 84 ′ on stationary platen 14 and arm 88 ′ is connected to a lower anchor point 92 ′ on movable platen 32 . Extending arms 92 ′ and 94 ′ are pivotably connected to carriers (not shown) on the machine in the same manner as arms 92 and 94 . However, the longer portion 92 a ′ of arm 92 ′ is the upper portion of the arm and the longer portion 94 b ′ is the lower portion of arm 94 ′. By reversing the two assemblies 38 , the forces driving the molds between the open and closed positions are balanced and the molds close uniformly.
[0062] The linking arms 86 ′, 88 ′, 92 ′, 94 ′, 96 ′ and 98 ′ are also dimensioned so that they do not interfere with access to the cores and cavities when the mold is open. Thus, the molding machine provides ready access to the open molds from above, below and both sides. As will become apparent hereinafter, this enables the rapid and simple ejection of molded parts and easy and rapid replacement of moldsets.
[0063] FIG. 10 shows the cavity plates 40 , 42 , and 44 , core plates 48 , 50 and 52 and the fixed hot runner 30 and movable hot runners 33 and 34 separate from the injection-molding machine. Cavity plate 40 is attached to core plate 48 by latches 100 (only one shown). Each hot runner includes four hot runner leader pins 102 to align the respective cavity plate with the hot runner. Hot runner nozzles 104 extend out of each hot runner and into the associated cavity plate. Four straight interlocks 101 at the midsection of each cavity plate 42 and 44 interface with matching slots 103 on the respective hot runners. Cavity plate 40 only has three interlocks 101 because a slot 80 is formed in the plate 40 to permit the plate 40 to slide over the sprue bar 76 . The leader pins 102 ensure reasonable alignment of the cavity plates with the associated hot runner and the precise shape of the interlocks 101 and slots 103 tightly align the nozzles 104 with the gates of the cavities in the cavity plates. The outermost ends of the interlocks 101 are slightly tapered to ensure that the interlocks 101 enter into the slots 103 and do not have sharp corners that can impact on one another and cause damage. This ensures that the moldsets can be changed often without the creation of alignment concerns over time.
[0064] One embodiment of the guide slots for guiding the core plates onto the hot runners 33 and 34 is shown schematically in FIG. 11 . At the top of each hot runner 33 and 34 and movable platen 32 is a guide plate 106 . The guide plate 106 has a tapered surface 108 for receiving and guiding the core plate into the receiving slot 110 . A slightly raised surface 112 on the outer surface of each guide plate 106 forces the core plate away from the hot runner or movable platen so that the core plate does not scuff against the hot runner plate or the movable platen as it is being guided and loaded onto the machine.
[0065] FIG. 12 shows a core plate 114 being guided into a slot 110 and being pushed slightly away from the surface of the movable platen 32 by the raised surface 112 . A cavity plate 116 is attached to the core plate 114 . Water connections or nipples 118 extend from the water manifold 120 and will engage in connectors on the base of the core plate 114 when the core plate is placed in molding position. Guide pin 119 guides the core plate 114 onto the water manifold 120 to ensure a secure connection of the connectors 118 to the female connectors on the core plate 114 .
[0066] FIG. 13 is a partial assembly showing the guide slot 74 on core plate 52 just entering the guide plate 106 . The tapered surface 115 at the front edge of slot 74 permits the core plate 52 to align with the guide plate 106 . The raised surface 112 on the guide plate 106 moves the core plate 52 away from the surface of the movable platen 32 so the core plate 52 does not scuff against the surface of the platen 32 as it is being loaded into the machine. The female connectors 121 on the underside of core plate 52 engage connectors 118 when the core plate is fully loaded into the movable platen 32 .
[0067] FIG. 14 is a perspective view of the movable platen 32 with the guide plates 106 and 122 installed. The guide plates 106 are mounted on an upper portion of the platen 32 and lower guide plates 122 are mounted on a lower portion of the platen 32 . Wedge plates 124 are mounted on water manifold 120 . A wedging surface 126 is formed on the upper end of plates 124 and engage the front face of the core plate when it is nearing its fully mounted position. The wedging surfaces 126 force the core plate into firm contact with the platen 32 . It is noted that each core plate is loaded in this same manner so it is unnecessary to describe the loading operation for the other two core plates onto the movable hot runners 33 and 34 .
[0068] FIG. 15 shows the core plate 52 fully installed on platen 32 and wedged tightly against platen 32 by wedge surface 126 on wedge plate 124 and a wedging surface on the separation block 140 . The separation block 140 is more fully described hereinafter.
[0069] FIG. 16 shows the flexible water lines 62 extending to the manifolds 120 on each hot runner. One set of lines 62 extends under tiebars 18 on one side of the machine and the other set of lines 62 extends along the underside of the other lower tiebar 18 . Lines 62 are out of the way of the mold opening so parts can be dropped downwardly without encountering interference from any components of the machine.
[0070] FIG. 17 shows a core plate 50 secured to movable hot runner 33 . Cavity plate 42 is secured to core plate 50 by latches 100 (only one shown) and is ready to be secured to the hot runner plate.
[0071] With this new design, the replacement of molds and servicing of the machine are much simplified over earlier designs
[0072] First, the mold guides 106 and 122 are installed on the movable platen 32 and movable hot runners 33 and 34 . The water manifolds 120 and wedge plates 124 are also installed on the movable platen 32 and movable hot runners 33 and 34 . The water manifolds 120 are installed on carriers 70 and the flexible water lines 62 attached from below. As shown in FIG. 3 , the movable hot runners 33 and 34 are each installed on carriers 70 and the hot runner 30 is bolted to the fixed platen 14 . Next, as shown in FIG. 5 , the moldsets 24 , 26 and 28 are lowered onto the hot runners 33 and 34 and the movable platen 32 , one at a time. A dial indicator, to be described hereinafter, is provided to indicate when the moldset is properly seated and the air and water connections are secure. When the moldset is in place it is bolted to its associated platen or hot runner and the crane hook is removed. After all three moldsets have been bolted, the machine is slowly closed to permit the cavity plates 40 , 42 and 44 to engage hot runner leader pins 102 , straight interlocks 101 and hot runner nozzles 104 . Clamp tonnage is then applied and each cavity plate is partially bolted to the hot runner associated with it. The bolts are sufficient in number to ensure that the cavity plate is secure when separated from the core plate. The stack mold carrier to hot runner bolts are now tightened. At this point, the latches 100 and the moldset lift bars are removed. The molds can now be slowly opened with the core plates separating from the cavity plates. When the molds are open the remaining cavity plate bolts can be tightened and the electrical cables attached to the top of the hot runners. The machine is now ready to mold parts.
[0073] When replacement of the moldsets is required, the procedure is reversed. The mold is opened and latches 100 are slid onto the cavity plates. Most of the bolts securing the cavity plate to the hot runner are removed. The remaining bolts need only hold the cavity plate in position. The mold is closed and the latches 100 are attached to the core plate. The remaining bolts securing the cavity plate to the hot runner are removed and the mold is opened. Now the crane hook can be attached to the moldset and the moldset removed from the machine.
[0074] The injection molding machine provides pre-assembled moldsets for each family of parts to be molded so that the moldsets can be changed quickly and efficiently. The guided moldset loading ensures that the moldsets install with minimal operator intervention. The hose-less coupling of the services ensures quick, sure and easy coupling of services to the machine and moldsets. The open linkage assembly ensures that parts can be readily retrieved by a robot from either side of the machine or simply freely dropped through the bottom of the machine. The robot could even enter from atop the machine.
[0075] FIGS. 18 to 21 illustrate apparatus for automatically connecting air supplies to the core plate. The apparatus also provides guide surfaces to keep the core plate away from the hot runner or platen faces during loading of the core plate and positively moving the core plate toward the platen or hot runner face when the core plate is near the end of travel. During removal, the apparatus moves the core plate away from the platen or hot runner face at the start of travel. The apparatus also provides means for indicating the positive loading of the core plate. In this embodiment, the core plate 148 has guide slots 174 for guiding the core plate 148 onto guide plate 206 in the same manner as previously described with reference to core plate 48 . Core plate 148 includes core plate separation blocks 140 and 142 . Each separation block 140 and 142 includes an air channel or channels to provide air to the core plate to enable ejection of parts from the cores on the core plate. This creates a separation of the air supply from the water supply at the base of the core plate thus reducing the possibility of contamination of the air supply in the event that the water supply remains pressurized when a core plate is not in position on the mold. Each guide plate 206 includes an air channel with a discharge outlet 144 . As the core plate 148 slides into position, an air opening 138 in the undersurface of each core plate separation block 140 and 142 engages a discharge outlet 144 . To ensure that the opening 138 makes an airtight seal with the outlets 144 , each outlet 144 has a compressible and pliable exit surface. In some instances, it may be desirable to provide the openings 138 with a similar compressible and pliable surface. A preferred material for the discharge outlets 144 is Ultra High Molecular Weight Polyethylene (UHMWPE).
[0076] The angular surface 146 , shown in FIG. 20 , on the separation blocks 140 and 142 engages a camming surface (not shown) on the guide plate 206 . The camming surface forces the separation blocks 140 and 142 and joined core plate 148 towards the platen or hot runner when the core plate is nearing its end of travel. A distance of approximately 50 mm from the end of travel is considered a reasonable place for this camming action to start. At the same time as this camming action is initiated, the wedge surfaces 126 on the wedge plates 124 are forcing the lower portion of the core plate 148 toward the face of the hot runner or platen. Thus, the core plate is forced toward the platen or hot runner in an upright manner so that it engages the platen or hot runner face evenly. This camming action also causes the opening 138 to positively engage with the discharge outlet 144 .
[0077] The angular surface 150 , shown in FIG. 21 , on the core plate separation blocks 140 and 142 acts with corresponding sloped surfaces (not shown) on the guide plates 206 to cam the core plate away from the platen or hot runner face upon initial movement of the core plate during extraction of the core plate from the mold.
[0078] Another feature of the machine is the provision of a dial indicator 130 shown in FIGS. 22 and 23 . Compression of the extended rod 132 by the downward movement of the core plate separation blocks 140 and 142 indicate directly whether the blocks 140 and 142 and the core plate 148 to which they are attached have been properly secured in the machine. The dial indicators 130 are situated under an overhang of the guide plate 206 so that they are protected from incidental contact. The use of two indicators provides an operator with the choice of standing on either side of the machine while the core plates are being installed. In operation, the dial indicators would be set during the initial or first installation of a moldset in the machine. This setting would be used to measure the proper insertion of subsequent moldsets.
[0079] As shown in FIGS. 24 and 25 , the water manifolds 120 are bolted to the carriers 70 and provide nipple connections 118 to the hot runners 33 and 34 and the core plates (not shown). When the hot runners and core and cavity plates are guided onto the carriers 70 , the nipple connectors 18 automatically engage corresponding openings in the hot runners and core and cavity plates. The guide pins 152 on the top of the water manifold 120 serve to guide a core plate 48 or 148 onto the manifold 120 and ensure that the tapered female connectors 121 on a core plate 48 or 148 are aligned with the nipples 118 along the front edge of the manifold 120 .
[0080] It will, of course, be understood that the above description has been given by way of example only and that modifications in detail may be made within the scope of the present invention.
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A method of loading a moldset having a core plate and a cavity plate into an injection molding machine. The method comprises the steps of latching a cavity plate to a core plate using a removable latch, guiding the core plate into an open mold along a face in the mold while maintaining separation between the face and the core plate and maintaining the cavity plate spaced from hot runner nozzles in a hot runner in the mold, closing the mold to engage the cavity plate with the hot runner nozzles, securing the cavity plate to the hot runner, removing the latch between the cavity plate and the core plate, and opening the mold. The face may be a face of a movable platen or a back surface of a hot runner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a card-feeding mechanism, and more particularly, to a card-feeding mechanism implemented in a printer for ID cards.
2. Description of the Prior Art
A card-feeding mechanism can be positioned at an input of a printer of ID cards to deliver cards into the printer. The card-feeding mechanism drives a roller beneath a card, and when a friction force between the card and the roller is greater than a friction force between stacked cards, the card can be delivered into the printer. Furthermore, there is a limiting device in the card-feeding mechanism for assisting the bottom card in moving into the printer and keeping other cards in their respective positions.
Please refer to FIG. 1 , which is a card-feeding mechanism 10 according to the prior art. A limiting device 12 of the card-feeding mechanism 10 can keep all cards 11 over a bottom card 13 in their respective positions. A roller 14 is connected to a motor 15 that drives the roller 14 to rotate and move the bottom card 13 into the printer. Additionally, there is another roller 16 positioned on the other side of the limiting device 12 , and connected to a motor 17 . The roller 16 is capable of assisting the card 13 in passing through the limiting device 12 until the card 13 is completely inside the printer and is ready to be printed.
The roller 14 has a rubber surface for increasing a friction coefficient between the roller and the card 13 . However, often an adhesive material is added to the roller 14 for improving the friction coefficient between the roller and the card 13 , and thus, the roller 14 requires constant maintenance. In addition, there is only one roller 14 before the limiting device 12 to deliver the card 13 , and so the transmission of the card 13 is not very smooth. Therefore, some printers include a sensor to detect whether a card has become stuck or if there is any other malfunction during operation.
SUMMARY OF THE INVENTION
It is therefore a primary objective of the claimed invention to provide a card-feeding mechanism that has improved performance to solve the above-mentioned problem.
The claimed invention discloses a card-feeding mechanism. The card-feeding mechanism comprises a card-delivering device, a card-receiving device, a transmission device, a driver, and a sensor. The card-delivering device pushes a card in a first direction, and the card-receiving device continuously pushes the card in the first direction. The transmission device is positioned between the card-delivering device and the card-receiving device for engaging the card-delivering device and the card-receiving device when the transmission device is driven forwardly to simultaneously drive the card-delivering device and the card-receiving device, and for engaging the card-receiving device and disengaging from the card-delivering device when the transmission device is driven backwardly to drive the card-receiving device. The driver engages the transmission device for driving the transmission device. The sensor detects the pushed card. When the sensor detects the pushed card, the transmission device stops driving the card-delivering device.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a card-feeding mechanism according to the prior art.
FIG. 2 shows a card-feeding mechanism based on the present invention.
FIG. 3 shows a unidirectional bearing, the second gear, and the second roller of FIG. 2 .
FIG. 4 is a lateral view when the card-feeding mechanism of FIG. 2 is not operating.
FIG. 5 to FIG. 7 show how the card-feeding mechanism of the present invention operates.
DETAILED DESCRIPTION
Please refer to FIG. 2 , which shows a card-feeding mechanism 100 based on the present invention. The card-feeding mechanism 100 comprises a card-delivering device 130 , a card-receiving device 140 , a transmission device 120 , a driver 110 , a limiting device 150 , and a sensor 160 . The details for each device are described as follows.
The card-receiving device 140 comprises a third roller 146 having an eighth gear 144 positioned on an axle 148 of the third roller 146 , and a ninth gear 142 positioned between the eighth gear 144 and the transmission device 120 . The transmission device 120 is a V-shaped panel. There are a fifth gear 122 positioned at a first end of the V-shaped panel, a sixth gear 124 positioned at a second end of the V-shaped panel, and a seventh gear 126 positioned between the fifth gear 122 and the sixth gear 124 and engaging the driver 110 . The driver 110 comprises a motor 122 and a gear set comprising gears 114 and 116 .
The card-delivering device 130 comprises a first roller 131 having a first gear 133 positioned on an axle 132 of the first roller 131 , a second roller 134 having a second gear 136 positioned on an axle 135 of the second roller 134 , a third gear 138 positioned between the first gear 133 and the second gear 136 , and a fourth gear 139 positioned between the second gear 136 and the fifth gear 122 of the transmission device 120 .
Please refer to FIG. 3 , which shows a unidirectional bearing 137 , the second gear 136 , and the second roller 134 of FIG. 2 . The unidirectional bearing 137 is positioned inside the second gear 136 . When the transmission device 120 drives the card-delivering device 130 to rotate, the unidirectional bearing 137 causes the second gear 136 to drive the second roller 134 to rotate. The unidirectional bearing 137 causes the second roller 134 not to drive the second gear 136 to rotate when the transmission device 120 does not drive the card-delivering device 130 .
Please refer to FIG. 4 , which is a lateral view when the card-feeding mechanism 100 of FIG. 2 is not operating. The limiting device 150 limits a thickness of cards 171 , 172 to ensure there is only one card passing through the limiting device 150 at a time. When the card-feeding mechanism 100 does not operate, the fifth gear 122 of the transmission device 120 engages the fourth gear 139 of the card-delivering device 130 while the sixth gear 124 of the transmission device 120 engages the ninth gear 142 of the card-receiving device 140 . The seventh gear 126 of the transmission device 120 engages the gear 116 of the driver 110 for receiving a rotating force provided by the motor 112 .
Please refer to FIG. 5 , which is a lateral view when the card-feeding mechanism 100 of FIG. 2 starts to operate. When the motor 112 starts to rotate clockwise, the gear 114 positioned on the motor 112 also rotates clockwise, and provides the rotating force to the transmission device 120 via the gear 116 . After the motor 112 rotates, the V-shaped panel swings to engage the fifth gear 122 with the eighth gear 144 , and then swings to engage the fourth gear 139 with the ninth gear 142 . Therefore, the transmission device 120 is simultaneously connected to the card-delivering device 130 and the card-receiving device 140 via the fifth gear 122 and the sixth gear 124 to cause the transmission device 120 to drive the card-delivering device 130 and the card-receiving device 140 . As shown in FIG. 5 , the first gear 133 , the second gear 136 , and the eighth gear 144 rotate counterclockwise simultaneously and drives rollers 131 , 134 , 146 correspondingly.
The friction forces between the card 171 and the first roller 131 , and between the card 171 and the second roller 134 are greater than the friction force between the cards 171 and 172 due to the rotation of the first roller 131 and the second roller 134 . Therefore, the card 171 can be pushed in a first direction. When the card 171 passes through the limiting device 150 , the third roller 146 of the card-receiving device 140 assists the card 171 in moving in the first direction.
Please refer to FIG. 6 , which is a lateral view when the motor 112 rotates in reverse. When the sensor 160 detects the card 171 , a signal is sent to cause the motor 122 to rotate in reverse (counterclockwise). At the same time, the seventh gear 126 receives a reverse rotation. Since a torque generated by the friction force between the V-shaped panel and the central axle of such is smaller than a torque generated by the friction force between the V-shaped panel and the fifth gear 122 , and between the V-shaped panel and the sixth gear 124 , when the motor 122 rotates in reverse, the fifth gear 122 of the transmission device 120 disengages the fourth gear 139 of the card-delivering device 130 , and engages the eighth gear 144 of the card-receiving device 140 . The sixth gear 124 of transmission device 120 also disengages the ninth gear 142 of the card-receiving device 140 . Therefore, in FIG. 6 , the transmission device 120 only drives the card-receiving device 140 while the first roller 131 and the second roller 134 are driven by the movement of the card 171 .
Please refer to FIG. 7 , which is a lateral view after the motor 122 rotates in reverse. In FIG. 7 , the card 171 departs from the first roller 131 , and only drives the second roller 134 to rotate. Due to the unidirectional bearing 137 , the rotation of the second roller 134 will not drive the second gear 136 to rotate. Thus, the second gear 136 and the unidirectional bearing 137 of FIG. 7 remain still. The card 172 on top of the card 171 contacts the first roller 131 . Because of the friction force between the card 172 and the first roller 131 , the first roller 131 is still until the card 171 is completely pushed into the printer to cause the motor 122 to rotate clockwise, thereby starting to push the next card 172 into the printer.
Compared to the prior art, the card-feeding mechanism 100 of the present invention utilizes the first roller 131 and the second roller 134 to simultaneously push the card 171 in the first direction. This means that the card 171 is transferred more smoothly. Additionally, the friction force between the card and the two rollers 131 , 134 is increased, and thereby the present invention does not require adhesive material on the rollers 131 , 134 , increasing a life-span of the rollers 131 , 134 .
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A card-feeding mechanism has two rollers positioned before a limiting device, and a roller and a sensor positioned after the limiting device. When a motor rotates clockwise, a transmission device drives the three rollers simultaneously to deliver a card from a front end toward a rear end. When the sensor detects an edge of the card, the motor rotates counterclockwise, and only drives the roller after the limiting device. Then, the card is only driven by the roller after the limiting device, and the rollers before the limiting device are driven by the card.
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RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
The present invention relates generally to wiregrid polarizers, and more specifically to a new array pattern of individual wiregrids for use in imaging polarimeters.
Remote sensing applications can make use of the optical polarization characteristics of a scene to enhance target detection and discrimination. Imaging polarimeters utilize polarizing arrays positioned in front of a focal plane array of detector pixels to extract polarization information from the optical scene.
An integrated microgrid imaging polarimeter includes a repeating pattern of wiregrid polarizers bonded to a focal plane array. A wiregrid polarizer can be made as a layer of very thin ruled aluminum wires sandwiched between two glass windows. The most common microgrid arrangement is a 2×2 repeating pattern of so-called analyzer cells. A typical 2×2 array is shown in FIG. 1 . The lines in each cell correspond to the wiregrid element orientation. This specific pattern has been the standard since 1994.
Raw microgrid data are used to infer Stokes parameter images. The power spectrum of a raw microgrid image consists of a high bandwidth unmodulated S 0 image spectrum surrounded by the low bandwidth spectra of S 1 and S 2 . The S 1 and S 2 spectra are modulated out to the Nyquist frequency in the direction of the principal axes of the array. The connection between this Fourier analysis of modulated polarimeters as linear systems and the more widely known data reduction matrix was shown in 2012. The microgrid spectrum is similar to Color Filter Arrays (CFAs) used to extract color information for digital cameras, where a mosaic of tiny color filters are placed over the pixel sensors of an image sensor to capture color information, in that the high bandwidth spectrum centered at a DC-centered array corresponds to the luminance image and the low bandwidth modulated portions of the spectra correspond to chrominance.
Despite the long-term use of the standard 2×2 array and its pattern of different polarization directions, there is still a need for greater resolution and image quality.
SUMMARY OF THE INVENTION
To address this challenge, the teachings of the present invention provide a new 2×4 arrangement, or array, of individual wiregrid polarizers that minimizes the risk of aliasing between the Stokes vector images, providing maximum image bandwidth and, therefore, better resolution and image quality than prior art 2×2 arrays.
This new pattern improves image resolution and quality by increasing the spatial bandwidth available for each Stokes image despite that the new repeating pattern is larger than the standard prior art 2×2 design.
The polarization orientations of the wiregrid polarizers in each 2×4 array may, beginning from an arbitrary top left wiregrid polarizer of each array and continuing clockwise, be: 45 degrees; zero degrees; 315 degrees; 90 degrees; zero degrees; 45 degrees; 90 degrees; and, 315 degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present invention will be better understood from the accompanying drawings illustrating various aspects and example embodiments of the invention and its teachings.
FIG. 1 shows a conventional prior art 2×2 microgrid array of analyzer cells.
FIG. 2 shows a 2×4 microgrid array of analyzer cells according to the teachings of the present invention, showing an example embodiment of differing polarization orientations.
FIG. 3 is a log-scale spectra of microgrid polarizer array (MPA) sampled sensor data from a 2×4 microgrid array made according to the teachings of the present invention.
FIG. 4 compares a pair of reconstructed S 0 images for prior art 2×2 microgrid arrays and for 2×4 microgrid arrays made according to the teachings of the present invention.
FIG. 5 compares a pair of reconstructed Degree of Linear Polarization (DOLP) images for prior art 2×2 microgrid arrays and for 2×4 microgrid arrays made according to the teachings of the present invention.
DETAILED DESCRIPTION
Additional details of the teachings of the present invention are in D. LeMaster and K. Hirakawa, “Improved Microgrid Arrangement for Integrated Imaging Polarimeters,” Opt. Lett. 39, 1811-1814 (2014), the contents of which are incorporated by reference into this description.
The resolution of traditional, microgrid imaging polarimetric imagers suffers from that, to form an image, the imager, or camera, must combine information from multiple pixels, each sensing a different state of polarization, into a single unpolarized image. Or, the camera forms an image from a single polarization orientation, ignoring information from pixels sensing other polarization states. Either way, the camera cannot form an image having the quality one would expect from a camera possessing a similar number of unpolarized pixels. The present invention, however, provides a new pattern of wiregrid polarizers and a corresponding mathematical interpretation of the signals from the polarized pixels that can yield better image quality than conventional, state of the art, 2×2 polarizer arrays and their associated mathematical interpretation. This major advance over the state of the art thus addresses a key issue, enhancing the quality of images from polarimetric imagers without increasing the number of available pixels.
As described in the Background of the Invention, Color Filter Arrays are designed to improve spatial resolution by optimizing the separation between the luminance and chrominance spectra. The present invention draws on this approach to develop the new microgrid array pattern shown in FIG. 2 . This new pattern improves image quality by increasing the spatial bandwidth available for each Stokes image despite that the new repeating pattern is larger than the original 1994 2×2 design. This new pattern retains the noise performance optimality of the original pattern in terms of conditioning of the data reduction matrix.
The Stokes parameters=(S 0 , S 1 , S 2 ) T ε 3 follow a standard convention to describe linear polarization states in terms of radiometric quantities. The S 0 image contains grayscale spatial information about the scene. Images S 1 and S 2 together express the extent and orientation of linear polarization in the scene. The radiation recorded by each detector in a microgrid array Xε + is related to the Stokes parameters S of the incoming light by the equation:
X
=
[
1
2
❘
D
cos
(
2
θ
)
D
sin
(
2
θ
)
]
︸
A
θ
S
Eq
.
(
1
)
where, without loss of generality, the neutral density transmission losses in the analyzer are normalized out and Dε[0,1] is the diattenuation of the analyzer. Note that Stokes parameter S 3 is not treated in this analysis because the microgrid arrays of interest are not sensitive to it.
For imaging, the Stokes parameters refer to a function S: 2 → 3 , where S(η) is the Stokes parameter for the light arriving at the pixel location n=(η 1 , η 2 ) T ε 2 . For imaging with a microgrid polarizer array (MPA), an array of wiregrid polarizers is placed over an entire detector array, generally comprising a mosaic of corresponding detector pixels. As such, the pixel detector at location η makes exactly one measurement X(η) (X: 2 → + ) along one microgrid polarizer orientation θ(η) (θ: 2 → /2π), as follows:
X
(
n
)
=
A
θ
(
n
)
S
(
n
)
=
S
o
(
n
)
+
D
cos
(
2
θ
(
n
)
)
S
1
(
n
)
+
D
sin
(
2
θ
(
n
)
)
S
2
(
n
)
Eq
.
(
2
)
A finite number of polarizer orientations θε{θ 1 , . . . , θ K } are used in a microgrid polarizer array. The perspective adopted by the prior work on MPAs is that X(η) is a spatial multiplexing of A θ K S(η). For example, the 2×2 repeating MPA pattern takes the following form:
X
(
n
)
=
{
A
0
(
n
)
S
(
n
)
n
1
and
n
2
even
A
π
/
4
(
n
)
S
(
n
)
n
1
even
;
n
2
odd
A
π
/
2
(
n
)
S
(
n
)
n
1
and
n
2
odd
A
3
π
/
4
(
n
)
S
(
n
)
n
1
odd
;
n
2
even
=
S
0
(
n
)
+
(
D
2
)
(
-
1
)
n
1
(
S
1
(
n
)
+
S
2
(
n
)
)
+
(
D
2
)
(
-
1
)
n
2
(
S
1
(
n
)
-
S
2
(
n
)
)
Eq
.
(
3
)
Let denote discrete space Fourier transform, where S 0 (ω): { /2π} 2 → refers to the Fourier transform of S 0 at the two dimensional spatial frequency ω=(ω 1 , ω 2 ) T ε{ /2π} 2 , etc. The Fourier analysis of Eq. (3) is:
X
^
(
ω
)
=
S
^
0
(
ω
)
+
(
D
2
)
{
S
^
1
+
S
^
2
}
(
ω
-
(
π
0
)
)
+
(
D
2
)
{
S
^
1
-
S
^
2
}
(
ω
-
(
0
π
)
)
.
Eq
.
(
4
)
This type of Fourier analysis is by now standard in the related field of color filter array (CFA) imaging. By Eq. (4), one can reinterpret Eq. (3) also as a spatial frequency multiplexing where modulation by
ω ∈ { ( π 0 ) , ( 0 π ) }
separates Ŝ 1 +Ŝ 2 from Ŝ 0 , respectively. The sampling S→X is said to be aliased with
{ S ^ 1 + S ^ 2 } ( ω - ( 0 π ) )
and/or
{ S ^ 1 - S ^ 2 } ( ω - ( 0 π ) ) .
One can use standard amplitude demodulation to reconstruct S 0 , S 1 , and S 2 from X provided they are not aliased.
The Fourier support of {circumflex over (X)} is shown in the top of FIG. 3 . The modulation of Eq. (4) is evidenced by the concentration of energy near
ω = { ( 0 0 ) ( π 0 ) , ( 0 π ) } .
This figure is useful for assessing the risk of aliasing by the modulation frequency. For example, if the bandwidth of Ŝ 1 (ω) is λ (i.e., Ŝ 1 (ω)=0 ∀∥ω∥>λ), then Ŝ 0 (ω) must be zero ∀∥ω∥>π−λ in order to avoid aliasing (a requirement for recovering S from X). It is clear that there is a high risk of aliasing for a 2×2 repeating MPA pattern.
Drawing from the optimal CFA design approach described earlier, consider an alternative to the 2×2 repeating MPA pattern. Assume θ: 2 → /2π is linear with respect to η:
θ
(
n
)
=
1
2
ω
0
T
n
Eq
.
(
5
)
where ω 0 ε 2 . Letting Y: 2 → + denote sensor response to this new MPA, cos(2θ(η)) and sin(2θ(η)) in Y become sinusoidal modulators:
Y
(
n
)
=
A
θ
(
n
)
S
(
n
)
=
S
0
(
n
)
+
D
cos
(
ω
0
T
n
)
S
1
(
n
)
+
D
sin
(
ω
0
T
n
)
S
2
(
n
)
.
Eq
.
(
6
)
This gives rise to a straightforward Fourier analysis Ŷ of Y:
Y
^
(
ω
)
=
S
^
0
(
ω
)
+
(
D
2
)
{
S
^
1
-
j
S
^
2
}
(
ω
-
ω
0
)
+
(
D
2
)
{
S
^
1
+
j
S
^
2
}
(
ω
+
ω
0
)
Eq
.
(
7
)
where j=√{square root over (−1)}). Contrasting Eqs. (3) and (4) with Eqs. (6) and (7), respectively, the main difference is that the latter undergoes a spatial frequency modulation by ω 0 ε{ /2π} 2 . This is evident in the example Fourier support of Ŷ shown at the bottom in FIG. 3 , where
ω 0 = ( π / 2 π )
and the energy is concentrated near ω 0
∈ { ( 0 0 ) , ( ± π / 2 π ) } .
Clearly, the advantage of Ŷ in Eq. (7) over Eq. (4) is that the risk of aliasing has significantly reduced because the modulated components of the spectrum are more spread out.
The main conclusion from this analysis is that the modulation frequency ω 0 ε{ /2π} 2 is a design parameter for MPA patterns which should be chosen to minimize the risk of aliasing. Obviously, choosing ∥ω∥ to be as large as possible would avoid aliasing between Ŝ 0 (ω) and {Ŝ 1 −j Ŝ 2 }(ω−ω 0 ). But one must also consider the risks of aliasing contaminations between {Ŝ 1 −j Ŝ 2 }(ω−ω 0 ) and {Ŝ 1 −j Ŝ 2 }(ω+ω 0 ) which may occur if ω 0 and −ω 0 are close. Therefore, relative bandwidths of Ŝ 0 , Ŝ 1 , Ŝ 2 must be simultaneously considered.
Performance in the presence of noise is unaffected by the new array pattern. For proof, first consider a band-limited unaliased signal measured with the conventional 2×2 MPA. Demodulation of X yields:
S 0 (η)= H 0 (η)* X (η) Eq. (8)
( D/ 2){ S 1 (η)+ S 2 (η)}= H 1 (η)*{ e −j(0,π)η X (η)} Eq. (9)
( D/ 2){ S 1 (η)− S 2 (η)}= H 1 (η)*{ e −j(π,0)η X (η)} Eq. (10)
where * denotes convolution, and H 0 (H 1 ) are low pass filters designed to match the support of S 0 (S 1 and S 2 ). The Fourier domain equivalent of this process is:
Ŝ 0 (ω)= Ĥ 0 (ω){circumflex over ( X )}(ω) Eq. (11)
( D/ 2){ Ŝ 1 (ω)+ Ŝ 2 (ω)}= Ĥ 1 (ω){circumflex over ( X )}(ω−( π 0 )) Eq. (12))
( D/ 2){ Ŝ 1 (ω)− Ŝ 2 (ω)}= Ĥ 1 (ω){circumflex over ( X )}(ω−( 0 π )) Eq. (13)
which allows for the Stokes image spectra to be recovered via:
(
S
^
0
S
^
1
S
^
2
)
=
(
1
0
0
0
1
D
1
D
0
1
D
-
1
D
)
(
S
^
0
D
2
(
S
^
1
+
S
^
2
)
D
2
(
S
^
1
-
S
^
2
)
)
Eq
.
(
14
)
Under the same conditions, the 2×4 MPA yields:
S 0 (η)= H 0 (η)* X (η) Eq. (15)
( D/ 2){ S 1 (η)+ jS 2 (η)}= H 1 (η)*{ e −jωT 0 η X (η)} Eq. (16)
( D/ 2){ S 1 (η)− jS 2 (η)}= H 1 (η)*{ e jωT 0 η X (η)} Eq. (17)
and the Stokes spectra are recovered from:
(
S
^
0
S
^
1
S
^
2
)
=
(
1
0
0
0
1
D
1
D
0
-
j
D
j
D
)
(
S
^
0
D
2
(
S
^
1
+
j
S
^
2
)
D
2
(
S
^
1
-
j
S
^
2
)
)
Eq
.
(
14
)
In both Eqs. (14) and (18), the matrices that recover the Stokes spectra from the demodulation products have the same condition number, for example, for D=1 the condition number of each is
1 2 .
Both MPA are equally conditioned and therefore expected to provide equivalent performance in the presence of noise.
Synthetic imagery is used to demonstrate the wider unaliased bandwidth and thus superior image quality of a 2×4 array. Raw microgrid data of each array type are generated from Stokes imagery of a static scene originally collected with a visible Rotating Analyzer (RA) imaging polarimeter. Before microgrid resampling, the total bandwidth of each RA Stokes images was limited using an 11×11 pixel Gaussian filter with a 0.5 pixel standard deviation. The log-scale spectra of the synthetic MPA images in FIG. 3 show that the 2×4 array reduces the risk of aliasing by further separating out the various polarimetric image components. The conversion from Stokes to raw microgrid data is accomplished by Eq. (6). The modeled microgrid analyzers have unity diattenuation. For both the 2×2 and 2×4 cases, all Gaussian reconstruction filters have a support of 41×41 pixels and a standard deviation of 1 pixel.
More importantly, this difference in array arrangement is manifest in the reconstructed S 0 and Degree of Linear Polarization (DOLP) images. DOLP, P(η) (P: 2 → + ) is recoverable from the Stokes images by the relation:
P
(
n
)
=
S
1
2
(
n
)
+
S
2
2
(
n
)
S
0
(
n
)
Eq
.
(
19
)
Physically, DOLP is a measure of the extent of polarization inferred for each pixel in the scene. Aliasing in microgrid imagery is readily observable as false DOLP signals.
The reconstructed S 0 and DOLP images for each array configuration are shown in FIGS. 4 and 5 , respectively. The 2×2 array results are clearly more aliased than their 2×4 counterparts, but the difference is especially noticeable throughout the DOLP images. Fidelity to the original Stokes images can also be quantified using root mean squared error (RMSE). Table I shows that RMSE is lower in the images reconstructed from the 2×4 MPA in every case.
TABLE I
Root Mean Square Error Comparison (units of digital counts)
Between True Image and Reconstructed Images
Image
2 × 4
2 × 2
S 0
7.02
15.47
S 1
6.27
8.77
S 2
7.54
9.78
The polarimetric sampling arrangement of the present invention represents the first major improvement in spatial resolution for microgrid-integrated imaging polarimeters in almost 20 years. This improved array widens the unaliased bandwidth available for image reconstruction by increasing the separation between the spatially modulated Stokes components of the microgrid spectra. This outcome is achieved without affecting performance in the presence of noise.
The relationship between components of the microgrid spectra is a consequence of the periodic sampling array and independent of detector size. Consequently, this refined microgrid pattern will be useful even as technology to produce smaller detectors and microgrids continues to improve. A 2×4 pattern made according to the teachings of the present invention has multiple other equally valid polarization orientation patterns and their transposes which can be similarly successfully used for other imaging applications.
Those having skill in the art of the invention will readily recognize that terms used in this description and in the claims have their ordinary meanings as understood in the imaging art. For example, the term “focal plane” refers to the plane at which an optical image is focused for purposes of detecting that image along that plane using detector cells or pixels.
Similarly, those having skill in the art of the invention will recognize that, analogous to as described in connection with Color Filter Arrays, each 2×4 array comprises eight individual wiregrid polarizers, each individual wiregrid polarizer having a polarization orientation in a specific direction. A microgrid imaging polarimeter, or an imaging microgrid polarimeter, comprises a plurality of such 2×4 arrays of individual wiregrid polarizers.
Those having skill in the art of the invention will similarly recognize that the equations supporting the new 2×4 array are based on the wiregrid polarizers being proximate to the focal plane and detector cells along the focal plane.
Various modifications to the invention as described may be made, as might occur to one with skill in the art of the invention, within the scope of the claims. Therefore, not all contemplated example embodiments have been shown in complete detail. Other embodiments may be developed without departing from the spirit of the invention or from the scope of the claims.
|
An integrated microgrid imaging polarimeter comprises a repeating pattern of wiregrid polarizers in a new 2×4 array that improves image resolution and quality by increasing the spatial bandwidth available for each Stokes image despite that the new repeating pattern is larger than prior art 2×2 arrays. An example embodiment has polarization orientations of the wiregrid polarizers in each 2×4 array, beginning from an arbitrary top left polarizer of each array and continuing clockwise, as: 45 degrees; zero degrees; 315 degrees; 90 degrees; zero degrees; 45 degrees; 90 degrees; and, 315 degrees. The disclosure includes an analysis showing development of the new 2×4 array and supporting its improved performance over prior art 2×2 arrays.
| 6
|
This application is a division of application Ser. No. 09/162,692, filed Sep. 28, 1998, now U.S. Pat. No. 5,993,669, issued Nov. 30, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the electrolytic generation of a halogen, such as chlorine or bromine, for treating algae and bacteria within a water source, such as a swimming pool. More particularly, the present invention relates to an improved system of controlling the production of halogen through control of flow rate to the electrolytic cell and through control over the operation of the electrolytic cell in response to measured parameters in a flow stream to the cell.
2. Description of the Prior Art
The use of halogens, particularly chlorine, to treat water systems such as swimming pools for algae and bacteria has been well known. A common procedure involving the manual introduction of chemicals into the swimming pool, although seemingly simple, has associated problems involving labor and safety issues. This method requires that the water be tested frequently to determine when the chemicals need to be added or if the amount being used is proper. The manual introduction of the chemicals also means that a certain amount of time is required before sufficient dispersion will take place, which results in areas of higher concentrations of chemicals in certain portions of the pool and discomfort for swimmers entering these areas. These methods also require the transportation, storage and handling of often dangerous materials presenting issues of safety and liability for proper care.
Other techniques involve the electrolysis of a brine solution to generate a gaseous form of halogen, such as chlorine gas, which is then collected at the top of a chamber for introduction into the pool water system as disclosed in U.S. Pat. No. 4,693,806 to Tucker and U.S. Pat. No. 5,037,519 to Wiscombe. While these techniques may have reduced the amount of labor involved by eliminating the manual addition of chemicals into the pool and the frequent testing of the water to determine the proper application, concerns over safety remain. These methods require the use of a relatively complicated structure involving a barrier between the anode and cathode sides of the device in order to contain the brine, and to separate the gases which are produced, chlorine and hydrogen in the case of a chlorinator. A safety issue concerns the building up of excess gases in such a device, hydrogen being a highly explosive gas and chlorine gas being poisonous. The use of these systems therefore requires extra care to prevent release or explosion of such gases. These systems are also generally not without labor requirements. The use of the brine solution generally requires that the brine must periodically be replenished as it is depleted. Furthermore, water must be periodically added to maintain the brine in solution.
A further series of techniques involves the electrolytic generation of a halogen, such as chlorine or bromine, by flowing at least a portion of circulating pool water to which a relatively small amount of halogen salt has been added, through the cell to convert the halogen salt into halogen directly in the flow stream. In a chlorinator, for example, dissolved sodium chloride is converted into sodium hypochlorite, as is disclosed in U.S. Pat. No. 4,100,052 to Stillman. Stillman discloses a system which includes a controller for the electrolytic cell, the controller also being connected to the main circulating pump for the pool system. The control system of Stillman is built on a timing system wherein the pump has a cycle of operation and the cell has a shorter cycle contained within the cycle of the pump. An example given is a 12 hour on, 12 hour off cycle for the pump and a 12 minute on, 3 minute off cycle for the cell within the 12 hour on time of the pump.
The control systems of the prior art leave room for improvement in obtaining optimum halogen production for a given cell in a given system. A system that merely controls on/off time of the cell, for example, is not responsive to fluctuations in the flow rate which the circulating pump is presenting to the production cell. These fluctuations in flow rate could result, for example, from obstructions trapped in the filter of the system. Further, it is known in the art, that the production of halogen from an aqueous solution containing a dissolved halogen salt will vary depending on the temperature of the solution as well as the concentration of the halogen salt in the solution.
Therefore, it is an object of the present invention to provide a control system for halogen production in which the flow rate to an electrolytic cell is controlled and in which the operation of the cell is controlled in response to measured parameters including flow rate, water temperature and conductivity.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method and apparatus in a water treatment system for optimizing the production of a halogen used for treating carbon compounds including algae and bacteria. The halogen is produced directly in a portion of the circulating flow stream which has dissolved within it a halogen salt by electrolysis in a production cell. A spring check valve is used to control the flow rate to the production cell to a predetermined maximum, the remainder being diverted from the cell. To further optimize production, the flow stream to the cell is monitored for parameters including flow rate, water temperature and conductivity and the operation of the electrolytic cell is adjusted accordingly in response to the measured parameters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layout showing a typical swimming pool treatment system utilizing the present invention;
FIG. 2 is a sectional view of the halogen production portion of the system of FIG. 1;
FIG. 3 is a layout showing a multiple cell manifold utilizing the present invention; and
FIG. 4 is a layout showing multiple cell manifolds connected in parallel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a schematic of a water treatment system using the present invention is shown. The water source 10, a swimming pool in the case of the embodiment shown, has a relatively small amount of sodium chloride added. It has been found, for example, that a single addition of approximately 400 pounds of sodium chloride to a pool containing approximately 20,000 gallons of water, will serve as the source for the production of chlorine for an entire season because the chlorine is reconverted to sodium chloride in the water treatment cycle, as will be discussed below. As an option, the same system can be used to convert a salt of a different halogen, such as sodium bromide, into bromine which will be used to treat the water source. The salted water is circulated via pipeline 12 by pump 14. The water is then passed through filter 16 to remove debris which may be present in the system. Pump 14 and filter 16 represent typical pool equipment commonly found in swimming pool systems. It should be noted that the features of the present invention would be applicable to larger scale systems using appropriately sized components. Downstream of the filter, the piping system divides into piping sections 18 and 20. Contained within piping section 20 is a spring check valve 22 which serves to direct the pumped fluid into piping section 18 for up to a predetermined maximum flow rate of the pumped water and salt. After the predetermined rate of flow is reached, the spring check valve serves to divert that portion of the flow which exceeds the maximum rate desired in piping section 18, which for the present embodiment is 20 gallons per minute, through piping section 20. This arrangement allows for optimizing the production of chlorine by providing for the ideal amount of flow into piping section 18 regardless of fluctuation in the flow rate existing in piping section 12. Such fluctuations in flow rate could result, for example, from variation in the output of pump 14, or variations in the amount of flow through the filter 16 caused by trapped debris. Contained within piping section 18 is sensor 32 for checking the flow of salted water for parameters including flow rate, water temperature and conductivity, the conductivity measurement varying primarily in response to changes in the salt content of the flow stream. Sensor 32 communicates with a controller unit 38 via line 40. Downstream of sensor 32 and within piping section 18 is the production cell 42 which electrolytically converts the sodium chloride contained within the water into chlorine, in the form of sodium hypochlorite, according to the following equation.
NaCl+H.sub.2 O→e.sup.- NaOCl+H.sub.2
Electrolytic cells, such as cell 42 incorporated in the present invention, are available commercially as separate components by Autopilot Systems, Inc., of Fort Lauderdale, Fla., as Lectrantor® Models SRT-200-360, 600 or 840.
Although the pool system contains the above mentioned filter 16, the manifold also includes an in-line strainer 21 for protecting the cell 42 from debris that might bypass the main filter of the system. The in-line strainer 21 (FIG. 2) is most preferably located in a convenient location, such as in the region of the connecting union 25 contained in piping section 18, thereby facilitating periodic cleaning of the strainer.
The information regarding flow rate, temperature and conductivity which is monitored by sensor 32 is sent to controller 38 via line 40. This information is then used by the controller to control the operation of cell 42 via line 48. The controller ensures that a predetermined minimum flow rate is reached before powering the cell in order to protect the cell. The controller also monitors the flow rate during the operation of the cell, and will power down the cell if the flow rate drops below the required minimum. In a similar fashion, the controller will use-the information regarding water-temperature to keep the cell from operating if the water temperature is below a predetermined value. Below approximately 57° F., the chemical process involving the conversion of sodium chloride into sodium hypochlorite is suppressed to such an extent that powering of the cell would be ineffective. The controller uses the conductivity measurement to provide an indication in the event there is insufficient salt content present for the efficient production of chlorine by the electrolytic cell.
It is also possible, if pump 14 has multi-speed capabilities, to have controller 38 communicate with pump 14 via line 50 and control the rate of flow generated by pump 14 if sensor 32 monitors insufficient flow rate in piping section 18.
As seen in the figures, the combination which includes sensor 32, controller 38, lines 40 and 48, electrolytic cell 42, spring valve 22, in-line strainer 21, and piping sections 18 and 20 forms a unit which may be preassembled for easy installation into an existing or new pool system.
The chlorinated water exiting from cell 42 flows into piping section 48 and is prevented from flowing into piping section 20 by valve 22. The chlorinated water is then recirculated back into the water source 10 where the sodium hypochlorite acts on organic compounds such as algae and bacteria. The action of the sodium hypochlorite on the organic products within the water source reconverts the sodium hypochlorite back into sodium chloride according to the following equation.
C(organic compounds)+2NaOCl→CO.sub.2 +2NaCl
The system thus represents a cycle, wherein the same salt which was added at the beginning of the season is used repeatedly to form sodium hypochlorite.
Turning to FIG. 2, the construction of the chlorine production portion of the water treatment system is shown in greater detail. The spring check valve 22 has an outer housing 23 which mates with piping section 20. The valve mechanism includes a piston head portion 24 having an outer periphery which, under flow rates less than the 20 gallon per minute design rate, is seated against a projecting portion of the housing 23, thereby preventing flow past the valve and causing all flow to be diverted into piping section 18. Spring 26 is designed to provide a compressive force sufficient to maintain pressure between the piston head 24 and the projecting portion of housing 23 up to the design flow rate, at which point that portion of flow beyond the design flow rate is allowed to pass into piping section 20.
The in-line strainer 21, as seen in FIG. 2, is housed within a connecting union 25. The strainer 21 includes a basket portion 21A and has an annular disc 21B to which the basket 21A is attached. The annular disc 21B supports the basket in the flow stream through contact of the disc with the ends of sleeves 25A and 25C. A nut member 25B has a flanged portion for interfitting with a flange of sleeve 25A and for placing compression on the union 25 through engagement of threads on nut 25B with external threads on sleeve 25C.
The location of the union 25 directly opposite pipe juncture 45 in parallelly arranged pipe branches of the manifold, as seen in FIG. 2, facilitates access to the in-line strainer 21. By unthreading the nut 25B, the entire manifold assembly may be pivoted about juncture 45, thereby providing access for cleaning or replacement of strainer 21.
Sensor 32 is shown to have a housing 34 which contains probes 36 which extend into the flow area of piping section 18 such that the information regarding flow rate, water temperature and conductivity may be obtained and sent to the controller 38 via line 40.
Electrolytic cell 42 has a housing 44, which should be made of a material that is nonconducting and chemically resistant to the chemicals being processed. Polyethylene would be a suitable choice of material for the housing for the chlorine production of the current embodiment. The cell contains a set of closely spaced parallel plates 46 which serve as the electrodes in the electrolytic process. The plates 46 transmit an ion potential, as is disclosed in U.S. Pat. No. 4,100,052, and are constructed from conductive material such as aluminum or especially titanium.
Turning to FIGS. 3 and 4, manifold arrangements are shown which involve multiple cells for application in water systems where chlorine demand would exceed single cell capabilities. As opposed to operating a single chlorinator cell under a higher flow rate in order to obtain a desired amount of chlorine production, it is more effective to run multiple cells at a lower, more optimum, flow rate. FIG. 3 shows a manifold system having four cells 42 in series within piping section 18 downstream of sensor 32. As before, the flow rate to the cell is controlled through the use of spring check valve 22 in piping section 20. The multiple cell manifold of FIG. 3 also includes an as shown only in FIG. 2 in-line strainer 21 for protecting the electrolytic cells from debris which may bypass the main filter 16. The control system for the manifold is arranged as follows. The information regarding the flow parameters in piping section 18 is sent to a master controller 38A which is electrically connected to one of the cells 42 for control over the operation of the cell as was previously discussed. Master controller 38A is also electrically connected to slave controllers 38B, each of which is electrically connected to one of the remaining cells 42 for control over that cell. Thus, each of the cells 42 has an associated controller, but only the master controller 38A will establish the operating condition to be applied by all of the controllers.
FIG. 4 displays a dual manifold system, having parallel arranged manifolds each of which is constructed according to the arrangement of FIG. 3. Each of the parallel manifolds contains four cells arranged in series and four associated controllers, one of which functions as the master controller 38A in communication with sensor 32 and the remainder functioning as the slave controllers 38B.
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 therefrom. 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.
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Method and apparatus for optimizing the electrolytic production of a halogen in a water treatment system having a halogen salt dissolved therein. The flow rate to the electrolytic cell is maintained below a predetermined maximum beyond which the remaining flow is diverted from the cell. The flow going to the cell is monitored for flow rate, water temperature and conductivity and the operation of the electrolytic cell is adjusted in response.
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This application is a continuation-in-part of U.S. patent application Ser. No. 09/122,185, filed Jul. 23, 1998 which claims priority from U.S. provisional application No. 60/053,664, filed Jul. 24, 1997. The contents of both these applications are incorporated herein by reference.
BACKGROUND
1. Technical Field
This application relates to a surgical device for removing tissue and more particularly relates to a surgical tissue biopsy device insertable through a small incision in the body.
2. Background of Related Art
Over 150,000 women in the United States alone are diagnosed each year with breast cancer. A biopsy of breast tissue is indicated when a breast abnormality is found, allowing removal of the tissue and testing to determine whether the abnormality is malignant and further surgery is necessary. Early diagnosis and removal of cancerous tissue is critical for successful treatment as early detection greatly increases the chances of survival.
Numerous devices are currently available for performing breast biopsies. These devices function to dissect a portion of the breast tissue and remove it from the body for pathology to determine whether the tissue is malignant.
The most invasive procedure is referred to as open excisional biopsy. In this procedure, large tissue samples are surgically removed, requiring long recovery times, risking disfigurement of the breast, increased scarring and increased morbidity.
In an attempt to overcome the disadvantages of open surgery, more minimally invasive instruments have been developed. One minimally invasive approach utilizes a percutaneous instrument referred to as a fine needle biopsy instrument. In this instrument, a needle and syringe are inserted directly through the breast into the target tissue, e.g. the lump, to remove a cell sample for pathology. One disadvantage of this technique is that numerous cell samples are required to be taken from the tissue to obtain a sufficient mass for testing, thereby requiring numerous needle sticks and increasing the time required for the procedure. Another disadvantage is that careful locational tracking of the tissue cells removed is required for accurate analysis. Also, with these devices there is a greater potential for false negatives due to the small sized specimens being removed without removal of sufficient surrounding areas of healthy tissue for comparison.
Another type of minimally invasive device is referred to as core needle biopsy. This device has a spring actuated cutter and obtains a larger specimen than the fine needle biopsy instruments. The specimen is suctioned into a side window in the needle and then back through the proximal end of the needle. Although larger than fine needle biopsy instruments, these needles are still relatively small, e.g. 2 mm in diameter. Since typically removal of between five and twenty tissue cores of 2 mm in diameter and 20 mm in length is required for accurate pathology, five to twenty needle sticks into the patient of this 2 mm diameter needle is required. These devices also have the disadvantage that the spring force cutting action may displace malignant cells into the adjacent normal tissue. Also, the amount of false negatives can be high because of inadequate removal of surrounding healthy tissue. Like fine needle biopsy, success and accuracy of the procedure is skill dependent because the device must be maneuvered to various positions and these different positions accurately tracked.
Another disadvantage common to both fine needle and core needle biopsy devices is that the entire lesion cannot be removed. Therefore, if the tests show the lesion is malignant, another surgery must be scheduled and performed to remove the entire lesion and surrounding tissue. Besides the additional cost and surgeon time, this can have an adverse psychological affect on the patient who must await the second surgical procedure.
Some percutaneous devices, such as the Mammotome marketed by Ethicon, Inc., attempted to overcome some of these disadvantages of percutaneous devices by enabling multiple specimens to be removed with a single needle stick. The specimens are removed from the proximal end of the needle by a vacuum. Although overcoming some disadvantages such as reducing the number of needle sticks, the Mammotome still fails to overcome many of the other drawbacks since careful tracking is required, success is skill dependent, and a second surgery is necessary if the lesion is malignant, with the attendant expenses and trauma.
In an attempt to avoid a second procedure, the ABBI instrument marketed by United States Surgical Corporation provided a larger needle so that the entire specimen and tissue margins could be removed. The extra tissue excised is achieved by a larger diameter cannula. The cannula removes breast tissue from the skin surface entry point to the interior region of the breast where the lesion is located. The advantage of this instrument is that if pathology indicates the tumor is malignant, then an additional surgical procedure is not necessary since the tumor and margins were removed by the large cannula. However, a major disadvantage of this instrument is that if pathology indicates the lesion is benign, then a large tissue mass would have been unnecessarily removed, resulting in more pain, a larger scar, and possible disfigurement of the breast. Thus, ironically, the instrument is more beneficial if the tumor is malignant, and disadvantageous if the tumor is benign. In either case, the instrument has the further disadvantages of causing additional bleeding because of the large incision and requiring closure of a larger incision, thereby increasing scarring, lengthening patient recovery time, and adding to the cost, time and complexity of the procedure.
It would therefore be advantageous to provide a surgical breast biopsy device which can access the targeted lesion through a small incision but be able to remove the entire lesion and margin, thereby avoiding the necessity for a second surgery. Such device would advantageously reduce the risk of cancer seeding, provide more consistent testing, reduce surgery time, reduce bleeding, and minimize disfigurement of the patient's breast.
SUMMARY
The present invention overcomes the foregoing deficiencies and disadvantages of the prior art. The present invention provides a surgical biopsy apparatus for cutting tissue comprising a housing having a longitudinal axis, first and second members movable from a retracted position to an extended position with respect to the housing, a third member slidably positioned and extendable with respect to the first member, a fourth member slidably positioned and extendable with respect to the second member, and an electrocautery cutting wire movable with respect to the third and fourth members to surround a region of tissue positioned between the third and fourth members to cut the tissue.
The apparatus preferably further includes a tissue retrieval bag movable with respect to the third and fourth members and movable from a retracted position within the housing to an extended position distally of the housing to surround a region of tissue positioned between the third and fourth members to remove the cut tissue.
The apparatus preferably further comprises a first carrier slidably positioned over the first and third member, wherein the first carrier supports and advances the electrocautery wire and a suture for closing the tissue retrieval bag.
Preferably the first and second members move radially outwardly away from the longitudinal axis of the housing and the third and fourth members initially move radially outwardly away from the longitudinal axis followed by movement inwardly towards the longitudinal axis. The third member is preferably telescopingly received within a first channel in the first member and the fourth member is preferably telescopingly received within a second channel in the second member.
The present invention also provides a surgical biopsy apparatus for cutting a tissue mass comprising a housing, a plurality of first members extendable with respect to the housing and movable in a first direction at a first angle to the longitudinal axis of the housing, a plurality of second members movable with respect to the first members in a second direction different than the first direction and at an angle to the first angle, and a cutting wire movable longitudinally with respect to the first and second members to cut the tissue mass.
The apparatus preferably includes a tissue retrieval bag movable longitudinally with respect to the first and second members to remove the tissue mass cut by the cutting wire. Preferably, a loop of the cutting wire and a mouth of the tissue retrieval bag are enlarged by the plurality of first and second members.
The apparatus may include a marker supported within the housing and insertable into the tissue mass, the marker composed of shape memory material and the first and second members surrounding the marker. The first and second members may also be composed of shape memory material.
The present invention also provides a surgical biopsy apparatus comprising a housing, a plurality of members advanceable with respect to the housing to provide a boundary for an area of tissue to be removed, a cutting wire loop advanceable with respect to the plurality of members to cut the area of tissue and/or a tissue retrieval bag advanceable with respect to the plurality of members to remove the area of tissue. Preferably, the cutting wire loop and/or a mouth of the tissue retrieval bag is moved to a larger diameter as it is advanced with respect to the members. Preferably at least one carrier is provided which is advanceable over one of the plurality of members to advance the cutting wire and the tissue retrieval bag toward the target tissue.
The apparatus may also include an ultrasonic transducer at a distal end of the housing to enhance ultrasound imaging during the biopsy procedure.
The present application also provides a method for removing a tissue mass for biopsy comprising inserting a cannula to a position proximal of the target tissue mass, advancing a plurality of tissue penetrating members from the cannula to an angular position to create a boundary area around the tissue mass, and advancing an electrocautery cutting wire with respect to the tissue penetrating members to surround the tissue mass defined within the boundary area.
The method may further comprise the step of advancing a tissue containment bag with respect to the tissue penetrating members to encapsulate the cut tissue mass for removal, wherein the cutting wire and tissue containment bag are advanced substantially simultaneously.
A method for performing breast biopsy is also provided comprising inserting into breast tissue a housing having a diameter smaller than a diameter of the tissue to be biopsied, advancing penetrating members through the breast tissue to create a tissue boundary area having a transverse cross-sectional length greater than the diameter of the housing, and advancing a cutting wire so a loop of the cutting wire moves to a diameter greater than the diameter of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiment(s) of the present disclosure are described herein with reference to the drawings wherein:
FIG. 1A is a perspective view of the biopsy apparatus of the present invention in the initial position;
FIG. 1B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 1A showing the outer (female) rails in the retracted position;
FIG. 2A is a perspective view of the apparatus of FIG. 1 showing the outer and inner (male) rails in the fully deployed (advanced) position;
FIG. 2B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 2A;
FIG. 3A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position;
FIG. 3B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 3A;
FIG. 4A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position and the inner rails slightly advanced from within the outer rails;
FIG. 4B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 4A;
FIG. 5A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position and the inner rails partially advanced from within the outer rails;
FIG. 5B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 5A;
FIG. 6A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position and the inner rails further advanced to an intermediate position;
FIG. 6B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 6A;
FIG. 7A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position, the inner rails in the fully deployed (advanced) position, and the carriers initially advanced over the outer rails; (the cutting wire, suture, and bag being removed for clarity);
FIG. 7B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 7A;
FIG. 8A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position, the inner rails in the fully deployed position, and the carriers partially advanced over the inner rails past an intermediate position;
FIG. 8B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 8A;
FIG. 9A is a perspective view of the apparatus of FIG. 1 showing the outer rails in the fully deployed position, the inner rails in the fully deployed position, and the carriers extended over the inner rails to the fully deployed (advanced) position;
FIG. 9B is an enlarged perspective view of the distal end portion of the apparatus of FIG. 9A;
FIG. 10 is a longitudinal sectional view illustrating the interaction of the deployment rings, rails and carriers when the apparatus is in the initial position;
FIG. 11 is an enlarged view of a portion of the apparatus of FIG. 10 showing the proximal deployment rings for advancing the rails;
FIG. 12 is an enlarged view of a portion of the apparatus of FIG. 10 showing the distal deployment ring for advancing the carriers;
FIG. 13 is a longitudinal sectional view illustrating the interaction of the deployment rings, rails and carriers when the apparatus is in the fully deployed position;
FIG. 14 is an enlarged view of a portion of the apparatus of FIG. 13 showing the interaction of the deployment rings, rails and carriers;
FIG. 15 is an enlarged perspective view of the distal end of the apparatus of FIG. 13;
FIG. 16 is a further enlarged view of the distalmost portion of the apparatus of FIG. 15 illustrating the carriers fully advanced over the inner rails;
FIG. 17A is an enlarged transverse cross-sectional view showing engagement of the lock with the pin and carriers;
FIG. 17B is a further enlarged view of a portion of the apparatus shown in FIG. 17A;
FIG. 18A is an enlarged longitudinal sectional view showing the interaction of the pin, lock and rails in the deployed position of the apparatus;
FIG. 18B is an enlarged sectional view, cut in the longitudinal and transverse planes showing the interaction of the pin, lock and catheter in the deployed position of the apparatus;
FIG. 19 is an enlarged view of the apparatus of FIG. 1 showing a first embodiment of the carriers for supporting the cutting wire and suture;
FIG. 20 is an enlarged view of two of the carriers of FIG. 19 shown supporting the cutting wire and suture;
FIGS. 21A and 21B are enlarged front and rear views, respectively, of the carriers of FIG. 19 showing the cutting wire and suture extending through the respective openings;
FIG. 22 is an enlarged view of an alternate embodiment of the carrier having hooks to retain the cutting wire;
FIGS. 23 is a perspective view of an alternate embodiment of the apparatus of the present invention having a wire loop tissue marker, wherein the apparatus is shown with the marker deployed, the outer rails fully deployed, and the inner rails in the retracted position;
FIG. 24 is an enlarged view of the distal end of the apparatus of FIG. 23 showing the outer rails in the fully deployed position, the inner rails in the fully deployed position, and initial advancement of the carriers to advance the cutting wire, suture and tissue containment bag;
FIG. 25 is a top perspective view of the apparatus having an alternative mechanism for advancing the rails and carriers;
FIG. 26 is a bottom perspective view of the apparatus of FIG. 25;
FIGS. 27-34 are perspective views illustrating the method of using the apparatus of the present invention for excising breast tissue, wherein:
FIG. 27 illustrates the apparatus of the present invention approaching the breast to access the lesion;
FIG. 28 illustrates the cannula of the apparatus inserted through an incision in the breast in line with the lesion;
FIG. 29 illustrates the cannula inserted through an incision in the breast and the outer rails deployed proximally of the lesion;
FIG. 30 illustrates the inner rails deployed to an intermediate position and partially encircling the lesion;
FIG. 31 illustrates the inner rails fully deployed to encircle the lesion;
FIG. 32 illustrates partial deployment of the carriers to advance the cutting wire, suture and tissue retrieval bag;
FIG. 33 illustrates the carriers fully deployed with the tissue retrieval bag encircling the excised tissue;
FIG. 34 illustrates the apparatus with the tissue encapsulated in the retrieval bag withdrawn from the breast;
FIG. 35 is a perspective view of the apparatus inserted in a different orientation through an opening in a breast compression plate; and
FIG. 36 is a perspective view of an alternate embodiment of the apparatus of the present invention having a transducer for imaging.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now in detail to the drawings where like reference numerals identify similar or like components throughout the several views, the surgical apparatus for removing tissue is designated generally by reference numeral 10 in FIG. 1 . The apparatus 10 of the present invention is particularly designed for removing breast tissue, however use of the apparatus for removal, i.e. biopsy, of other body tissue is contemplated.
Referring to FIGS. 1A and 2A, apparatus 10 has a housing or cannula 12 , a series of deployment rings 20 , 30 , 40 , and a handle portion 14 . The ring 20 deploys outer (female) or first rails 50 and ring 30 deploys inner (male) or second rails 60 . As shown, outer rails (or outer tissue penetrating members) 50 and second rails (or inner tissue penetrating members) 60 are deployed from an initial position retracted within lumen 18 of cannula 12 as shown in FIGS. 1A and 1B to a deployed position where outer rails 60 encircle the tissue to be biopsied. The tissue is then severed and removed in the manner described below. As will be appreciated, the apparatus 10 enables removal of a lesion through a relatively smaller incision since the cannula 12 determines the size of the entry incision to the target site, and the rails 60 deploy radially outwardly defining an area having a diameter larger than the diameter of the cannula, thereby allowing a larger area/volume of tissue to be removed.
Cannula or housing 12 can be composed of two separate cannulas: a proximal cannula 13 extending from conically shaped handle portion 14 and a reduced diameter cannula 16 extending distally from proximal cannula 13 and beginning at plastic interface 13 a . Alternatively, cannula 12 can be composed of a single cannula having a larger diameter proximal portion (like cannula 13 ) and a smaller diameter distal portion (like cannula 16 ). A portion of cannula 16 or of the reduced diameter cannula portion is configured for insertion into the patient's body.
Cannula 13 preferably has a diameter D 1 of about 13 mm and cannula 16 preferably has a diameter D 2 of about 10 mm. Clearly other diameters are contemplated which can preferably range from about 30 to about 7 mm. Elongated slots 17 a and 17 b accommodate the respective pins of deployment rings 20 , 30 and 40 in the manner described below. A pair of identical slots is formed on the opposite side of cannula 13 to accommodate the second pins of the deployment rings 20 , 30 and 40 .
As noted above, in the initial position, the outer rails 50 are fully retracted and housed within channel 18 of reduced diameter cannula 16 as shown in FIGS. 1A and 1B. Outer rails 50 have a central lumen 52 for telescopingly receiving inner rails 60 . Thus, inner rails 60 are likewise retracted within cannula 16 in the initial position of the apparatus 10 .
In this initial position shown in the sectional views of FIGS. 10-12, first and second proximal deployment rings 20 and 30 are in the proximalmost position adjacent handle portion 14 and distal deployment ring 40 is in its proximalmost position. A pair of pins 22 , preferably spaced 180° apart, extends through respective apertures 24 in ring 20 to engage ring-like slug 25 . Slug 25 has a pair of radial openings 21 to frictionally receive metal locks 23 , and locks 23 have openings 26 to receive pins 22 . In this manner, ring 20 is operatively attached to slug 25 . The other radial openings 21 , which although do not receive pins 22 , have locks 23 seated therein.
Slug 25 also has a series of axial openings 28 , corresponding in number to the number of outer rails 50 , e.g. six. Outer rails 50 extend through these axial openings 28 in slug 25 and are affixed to locks 23 . That is, locks 23 have a pair of spaced apart legs or tabs 29 (see also FIG. 18A) which frictionally engage notches at the proximal end of outer rails 50 . In this manner, rails 50 are connected to slug 25 by frictional engagement with lock 23 . Thus, when pins 22 (and ring 20 ) are slid forward in slot 17 a , slug 25 and operatively connected outer rails 50 are advanced.
In a similar manner, ring 30 has a pair of pins 32 extending through respective apertures 34 to engage ring-like slug 35 and ring 40 has a pair of pins 42 extending through apertures 44 to engage ring-like slug 45 . Slugs 35 and 45 , like slug 25 , frictionally receive locks 33 , 43 within radial openings 36 , 46 , and have a series of axial openings 38 , 48 , to receive the inner rails 60 and carriers 70 , respectively. The number of openings 38 , 48 corresponds to the respective number of rails 60 and carriers 70 . Locks 33 and 43 have openings 31 , 41 to receive and secure the pins 32 , 42 . In this manner, rings 30 and 40 are operatively connected to slugs 35 and 45 . Locks 33 and 43 also have tabs 39 , 49 to receive the respective notches in the proximal portion of the rails 60 and carriers 70 . Thus, rings 30 , 40 are operatively connected to rails 60 and carriers 70 , respectively, for deployment thereof. (Engagement of lock 43 with the notches 73 of carriers 70 is best seen in FIGS. 17 B and 18 B).
To deploy the outer rails 50 , proximal deployment ring 20 is slid distally to advance slug 25 , carrying the rails 50 distally to advance from channel 18 of cannula 16 to the deployed position as shown in FIGS. 3A and 3B. (The pins in these FIG. as well as FIGS. 4-9 have been removed for convenience). Edge 19 of slot 17 a functions as a positive stop to limit travel of proximal ring 20 . As can be appreciated, in this position, rails 50 extend radially outwardly with respect to a longitudinal axis L of cannula 16 . In this position, rails 50 can direct inner rails 60 upwardly and outwardly with respect to the reduced diameter cannula 16 .
The outer rails 50 can have blunt tips as shown, or alternatively, to reduce the penetrating forces, can have more sharpened tips or beveled edges (described below) to facilitate cutting through tissue as they are advanced. Also, although six outer rails 50 are shown, a fewer or larger number of rails could be provided. Outer rails 50 are preferably composed of shape memory material with their memorized shape of that shown in FIG. 3 B.
Once the outer rails 50 have been deployed, proximalmost deployment ring 30 is linearly advanced to advance the inner rails 60 from within lumen 52 of outer rails 50 . As shown in FIGS. 4-5, as ring 34 is slid distally within elongated slot 17 a of channel 12 , slug 34 moves the inner rails 60 first radially outwardly with respect to the longitudinal axis L of cannula 16 at a similar angle to the angle of rails 50 , and then in a direction somewhat parallel to the longitudinal axis L to begin encircling the target tissue (FIGS. 6 A and 6 B). Further advancement of ring 34 moves the inner rails 60 inwardly toward longitudinal axis (as extrapolated) with their tips 64 coming together as shown in FIGS. 2A and 2B. Deployment ring 20 can act as a stop for advancement of deployment ring 30 . Alternatively, other means and mechanisms could be provided to provide a positive stop for advancement of the rings. In this fully advanced position, the rails 60 fully encapsulate, e.g., encircle the target tissue, defining a somewhat spherical tissue target region which can be of substantially circular or substantially elliptical transverse cross section. This target region has a diameter, defined by the distance D 3 between the opposing inner rails 60 , greater than diameter D 2 of the distal cannula 16 and diameter D 1 of proximal cannula 13 , thus enabling a larger region of tissue to be removed than the diameter of the incision. In a preferred embodiment, the distance D 3 is preferably slightly greater than about 3 cm, thereby allowing a 3 cm tissue region to be removed. It is also contemplated that other distances between the inner rails can be utilized.
As with the outer rails 50 , inner rails 60 can have blunt tips as shown, or alternatively, to reduce the penetrating forces, can have sharper pointed tips or beveled edges to cut through tissue as they are advanced. FIGS. 30 and 32, discussed below, show by way of example beveled penetrating tips. Also, although six rails are shown, a fewer or larger number of rails could be provided. Inner rails 60 are preferably made of shape memory material which have a memorized shape of that shown in FIG. 2 B.
As noted above, outer and inner rails 50 , 60 are preferably made of shape memory metal material, such as Nitinol, a nickel titanium alloy. To facilitate passage of the outer rails 50 through the housing, e.g.; cannula 16 , and facilitate passage of inner rails 60 through outer rails 50 into the tissue, cold saline is injected through or around the rails in their retracted position within cannula 16 . This shape memory material characteristically exhibits rigidity in the austenitic state and more flexibility in the martensitic state. The cold saline maintains the temperature dependent rails 50 , 60 in a relatively softer condition as they are in the martensitic state within the cannula. This facilitates the exit of outer rails 50 from cannula 16 and the exit of inner rails 60 from outer rails 50 as frictional contact between the tips of outer rails 50 and the inner surface of cannula 16 and frictional contact between the tips of inner rails 60 and the inner walls of outer rails 50 would otherwise occur if the rails were maintained in a rigid, i.e. austenitic, condition.
After deployment of the outer rails 50 , they are exposed to the warmer body temperature. This change in temperature causes the rails 50 to transition to their austenitic state to facilitate passage through the tissue. Similarly, after deployment of inner rails 60 from outer rails 50 , they are exposed to the warmer body temperature, thereby causing rails 60 to transition to their austenitic state to facilitate passage through tissue. A stopcock could be provided to ensure constant infusion of cold saline during advancement of the rails.
Once the inner rails 60 have been fully deployed, the carriers or catheters 70 are deployed to advance cutting wire 86 and suture 82 which is attached to tissue containment bag 84 . (The cutting wire 86 , suture 82 and bag 84 are not shown in FIGS. 7-9 for clarity). More specifically, as shown in FIGS. 7A and 7B, movement of distal ring 40 in a distal direction, advances carriers 70 from channel 18 of cannula 16 as pins 42 extending through distal ring 40 slide within slot 17 b to advance slug 44 .
One embodiment of the carriers 70 for retaining and advancing the wire 86 and suture 82 is shown in FIGS. 19-21. Each carrier 70 has a pair of cutting wire openings 74 a , 74 b and a pair of suture openings 72 a , 72 b positioned slightly proximally of openings 72 a , 72 b so that during advancement of carriers 70 , suture 82 will trail cutting wire 86 . One of the carriers 70 has a longitudinal slot 71 (see FIG. 18B) to enable the cutting wire 86 and suture 82 to extend proximally for attachment to a tension spring described in more detail below. For ease of manufacturing, each of the catheters 70 has a longitudinal slot so identical catheters can be made, however, optionally only one of the catheters 70 needs to be provided with the slot since the free end of the wire 86 and suture 82 can use a single passage proximally through the cannulas 13 and 16 .
Suture 82 , as shown, is threaded through adjacent carriers 70 as it extends through opening 72 a and exits opening 72 b in one carrier 70 , then extends through opening 72 a and out opening 72 b in an adjacent carrier 70 , and continues through openings 72 a , 72 b of adjacent carriers 70 until it extends through all the carriers 70 . One end of the suture 82 is looped (reference numeral 83 ) around tissue containment bag 84 and attached thereto so that tensioning of the suture 82 cinches the open end of bag 84 to close the bag around the tissue severed by cutting wire 86 . The free end of suture 82 extends rearwardly through (e.g. through slot 71 ) or adjacent one of the carriers 70 , and extends proximally within with one end affixed to the cannula or handle. To enable tensioning of the suture 82 , preferably a constant force spring (not shown) is mounted at one end within cannula 12 or handle 14 . The free end of suture 82 is mounted to the other end of the spring so that advancement of the suture 82 by the carriers 70 unravels the spring and applies tension thereto, thereby applying tension to suture 82 to close the mouth of the tissue containment bag 84 as it is fully advanced.
The cutting wire 86 is threaded through openings 74 a , 74 b in adjacent carriers 70 in a similar manner as suture 82 . That is, wire 86 extends into a carrier 70 through opening 74 a and exits the carrier 70 through opening 74 b where it can enter opening 74 a in adjacent carrier 80 . The wire is formed into a loop 85 as shown, with the free end extending proximally through one of the carriers 70 , e.g. through longitudinal slot 71 , terminating within cannula 12 . A constant force spring (not shown) is mounted at one end within cannula 12 or handle 14 and at another end to the proximal end of cutting wire 86 . A connection wire (not shown) electrically connects cutting wire 86 to an RF frequency source for applying RF energy to the cutting wire 86 . As cutting wire 86 is advanced, it is held in tension by the spring.
An opening 87 in carrier 70 has an internal diameter dimensioned to receive an outer rail 50 and an inner rail 60 . In this manner, carriers 70 , when advanced, can ride over rails 50 , 60 to advance the cutting wire 86 , suture 82 and bag 84 . Cutting wire 86 is preferably mounted to a radiofrequency energy source so RF energy is applied as wire 86 is advanced distally with respect to the rails 60 to progressively cut and cauterize the tissue.
Distal movement of ring 40 advances carriers 70 as they initially ride over the outer rails 50 as shown in FIGS. 7A and 7B, with opening 87 fitting over the outer surface of rails 50 . Further distal movement of ring 40 advance carriers 70 over inner rails 60 (FIGS. 8A and 8B) until they reach their final deployed position of FIGS. 9A and 9B. In this position, distal ring 40 is at the distalmost end of slot 17 b , with the edge 15 (see FIG. 1A) of the slots 17 b acting as a positive stop for pins 42 to limit forward travel of the ring 40 and slug 45 , and consequently limit travel of the carriers 70 . In this final position of the apparatus shown in FIGS. 9A and 9B, also shown in the enlarged views of FIGS. 15 and 16, the inner rails 60 and outer rails 50 are fully contained within channel 72 of carrier 70 . In this position, the cutting wire and the suture (with attached tissue containment bag) have traveled fully over the rails 50 , 60 to the distal tips 64 of inner rails 60 .
Note that as the carrier 70 is initially advanced over the rails, the diameter of the loop 85 of cutting wire 86 is enlarged since in this region outer rails 50 and inner rails 60 extend radially outwardly away from the longitudinal axis of the cannula 16 . As the carrier 70 is further advanced to intermediate region 63 of inner rail 60 , i.e. the region where the distance between opposing rails 60 peak and just before they begin their inward orientation towards the longitudinal axis of cannula 16 , the loop 85 will widen to its largest diameter, substantially equal to the diameter D 3 between opposing rails. This largest diameter of loop 85 defines the largest diameter of the tissue region being cut. As the wire 86 continues to advance past intermediate portion 63 of rails 60 , the diameter of the loop 85 reduces as the inner rails 60 extend inwardly towards the longitudinal axis L of cannula 16 and the distance between opposing inner rails 60 decreases. The spring attached at the proximal end applies constant tension to the wire 86 to reduce its loop size.
The suture loop 83 of suture 82 , which slightly trails wire 86 , is expanded and reduced in a similar manner as wire loop 85 as the carriers 70 advance over the rails 50 , 60 . That is, suture loop 83 increases in diameter, to thereby widen the opening 88 in tissue containment bag 84 , as carriers 70 advance to the intermediate region 63 of inner rails 60 . After advance past the intermediate region 63 , the suture loop 83 decreases in diameter to reduce the opening 88 in bag 84 as the spring at the proximal end of suture 82 applies constant tension to reduce the loop size. Thus, initial widening of suture loop 83 opens the mouth of bag 84 to receive the tissue mass severed by the cutting wire 86 , and reduction of the loop 83 as the suture 84 is pulled proximally by the tension of the aforedescribed spring closes the mouth of the bag 84 to entrap the severed tissue. The severed tissue can then be removed, fully enclosed in the bag, to prevent any undesired leakage. The opening, i.e. expansion, of the cutting wire 86 and the bag 84 is also described below in conjunction with the method of FIGS. 27-34.
Note that carriers 70 can have blunt tips as shown, or alternatively, to reduce the penetrating forces, can have pointed tips or beveled edges to cut through tissue as they are advanced. The number of carriers 70 can also vary, but preferably will be the same number as the number of outer and inner rails utilized. The carriers with the openings for the suture and wire can be integral with the elongated hollow member that rides over the rails or, alternatively, can be a separate component attached to the elongated members. For example, in FIG. 21B, the carrier 70 includes elongated carrier pusher 77 which can be integral with or attached thereto.
It is also contemplated, that instead of being retained inside cannula 12 , e.g. cannula 16 , prior to deployment, the tissue retrieval bag could alternatively be mounted outside the cannula, e.g. outside cannula 16 . This would reduce the overall size requirements of the cannula since the additional room for the folded bag within the cannula would not be required.
FIG. 22 illustrates an alternative embodiment of a carrier for retaining the cutting wire, suture and tissue retrieval bag. The bag and suture are mounted in a similar fashion as in the embodiment of FIGS. 21 . However, instead of openings through the carrier 70 , for the cutting wire, the carriers 70 ′ each have an eyelet 75 to retain the wire. The eyelets 75 are formed at the end of rods 76 which extending through longitudinal slot 71 . The free end of the wire 86 would extend through one of the longitudinal slots 71 in carrier 70 to a proximally positioned spring. This embodiment allows the entire region of the wire to be exposed to tissue. The suture is not shown for clarity but would extend through openings in the carrier in the identical manner as FIG. 21 .
In an alternate embodiment of FIGS. 23 and 24, a localization marker 110 can be utilized to identify the region and provide sonographic or x-ray visualization of the center of the tissue site. More specifically, apparatus 100 (only the distal portion is shown) contains a marker 110 having a wire 111 forming a wire loop 115 , which is preferably made of shape memory material such as Nitinol. In the retracted position, support tube 114 is contained within the cannula 112 and loop 115 is contained within support tube 114 in a substantially straightened configuration substantially aligned with the longitudinal axis of the support tube 114 and the straight portions of wire 111 . To mark the tissue site, support tube 114 is advanced from cannula 112 , and then wire 111 is advanced from channel 117 of support tube 114 so that wire loop 115 extends distally therefrom. Once advanced from support tube 114 , wire loop 115 returns to its memorized looped configuration of FIG. 23. A sharpened tip 119 facilitates insertion. Also, cold saline is injected into tube 114 as described above, thereby decreasing the frictional contact with the inner wall of tube 114 to facilitate advancement of the wire.
Wire loop 115 provides an indication via imaging or other visualization techniques of the target tissue, and more particularly a verification of the center of the target tissue. The rails 160 can then be advanced to encircle the wire marker 110 as shown in FIG. 24 .
In all other respects, the apparatus 100 of FIGS. 23 and 24 is identical to apparatus 10 of FIGS. 1-22, as it includes outer rails 150 , inner rails 160 , carriers 170 , a suture 182 attached to tissue containment bag 184 , and a RF wire 186 . The rails 150 , 160 and carriers 170 are advanced in the same manner as in apparatus 10 and therefore are not described again.
It is also contemplated that the wire marker can be used as confirmation of the position of the deployed inner and outer rails 50 and 60 . A lockout can be provided that would allow deployment of rails 50 and 60 only after the wire marker is advanced, thereby aiding the positioning of the rails with respect to the lesion.
Methods of utilizing the apparatus of the present invention for excising a lesion from the breast will now be described. It should be appreciated that the apparatus can be deployed either manually as in FIGS. 27-34, or machine actuated as in FIG. 35 .
Turning first to the method illustrated in FIGS. 27-34, in this method, the breast is not compressed and the apparatus, designated generally by reference numeral 200 , is deployed manually to access the target lesion and remove the lesion. Apparatus 200 is identical to apparatus 10 of FIGS. 1-21 except for the way the cutting wire is mounted to the carrier and the provision of beveled tips on the outer rails. The cutting wire is mounted to the apparatus via eyelets in the manner shown in FIG. 22 . Consequently, the apparatus 200 has been labeled with reference numerals in the “200” series to correspond to the double digit reference numerals of apparatus 10 . Mounting pins have also been removed for convenience.
Gripping handle portion 214 , apparatus 200 is inserted through incision “i” in the breast to access tissue lesion “t”. In this position, deployment rings 220 , 230 and 240 are in their proximalmost positions in respective slots 217 a , 217 b with the outer (female) rails 250 , inner (male) rails 260 , and carriers (catheters) 270 retracted within reduced diameter cannula 16 .
The cannula is then advanced through the incision “i” as shown in FIG. 28, in alignment with the lesion “t”, with the rails 250 , 260 and carriers 270 in the retracted position. Next, the outer rails 250 are advanced to the position of FIG. 29, still spaced proximally of lesion “t”. Outer rails have a sharpened edge 261 to facilitate passage through tissue. The edge could alternately be beveled to facilitate passage.
Inner rails 260 are then advanced from within outer rails 250 to encircle the lesion “t” as shown in FIGS. 30 and 31. Note that inner rails have beveled tips 261 forming sharpened edges to facilitate passage through tissue. As appreciated, both outer rails 250 and inner rails 260 return to their memorized shape, corresponding to their positions in FIG. 31, as they exit from the cool saline within cannula 212 and are exposed to the warmer body temperature. Since the rails extend radially outwardly after insertion of the cannula, the diameter of the tissue region to be excised (which is preferably substantially circular in cross section) exceeds the diameter of the cannula. Stated another way, the size of the excised tissue region can be increased without requiring a corresponding increase in the size (outer diameter) of the cannula. The region encapsulated is substantially spherical in shape and is much larger than the lesion.
Next, as shown in FIGS. 32 and 33, carriers 270 are advanced to advance cutting wire 286 and suture 282 extending around the mouth of tissue containment bag 284 . As cutting wire 286 is advanced by carrier 270 with respect to the outer rails 260 , RF energy is applied to the wire 286 to cut and cauterize the tissue surround the lesion “t”. As can be appreciated, the cutting wire 286 is progressively opened to a larger diameter as it is advanced to the intermediate region 263 of the rails 260 , substantially corresponding to the diameter of the sphere defined by the inner rails 260 . This diameter is substantially larger than the diameter of the lesion “t” to be removed. Thus, not only is the entire lesion “t” removed, but also a safety margin of tissue, e.g., about 1 centimeter radially in all directions from the lesion, is excised. If the safety margin is about 1 centimeter radially, the area of tissue removed will be about 3 centimeters.
Trailing cutting wire 286 is suture 282 and tissue containment bag 284 . Thus, suture 282 looped around the mouth of bag 284 progressively increases in diameter, thereby increasing the opening in the mouth of bag 284 as it is advanced to the intermediate region of outer rails 250 . Thus, as lesion “t” is excised, it enters the mouth of bag 284 and is captured therein. As the bag 284 completes its travel, i.e. the carrier 270 is advanced to the distal tips 261 of inner rails 260 , the mouth of the bag 284 is automatically closed by the tension of suture 282 around the mouth of bag 284 due to the proximally applied force of the spring attached to the free end of the suture as described above. Thus the excised tissue is fully captured within bag 284 . The lesion and area of surrounding tissue are withdrawn substantially intact for accurate pathology. Moreover, since sufficient margins have been removed, even if the tumor is malignant, a second surgery is not necessary. FIG. 34 illustrates apparatus 200 withdrawn from the breast with the tissue encapsulated within tissue containment bag 284 . The rails 250 and 260 are elastically deformable to enable compression of the specimen as the apparatus is withdrawn through the relatively small incision.
FIG. 35 illustrates the use of the apparatus with machine controlled deployment. In the method of FIG. 35, the breast is compressed between compression plates P 1 and P 2 to facilitate imaging as well as access to the lesion “t.” Apparatus 300 is advanced in the orientation shown, by table mounted controls (not shown), through aperture A in compression plate P 2 . That is, apparatus 300 would be positioned on a table, and advanced in a horizontal direction toward lesion “t”. The inner and outer rails and carriers are then advanced by preset machine actuated controls which engage the deployment rings via pins (not shown) to excise and remove the lesion. This is achieved by mounting pins to the apertures 324 , 334 and 344 in deployment rings 320 , 330 and 340 . The pins (not shown) will then be advanced by the table mounted actuators to advance the rings and connected slugs to deploy the rails and carriers in the manner described above.
The apparatus 400 of FIGS. 25 and 26 illustrates an example of machine controlled actuation similar to apparatus 300 of FIG. 35 . This apparatus differs only in that it has sliders which optionally allow for manual advancement if desired. That is, instead of automated actuation, the surgeon can advance sliders 423 , 433 and 443 , which have internal pins connected to the slugs in the same manner as described above.
For machine actuation of apparatus 400 , pins 422 , 432 and 442 would be placed within slots in the machine, either in the orientation of FIG. 25 or the orientation of FIG. 26, depending on the orientation of the table mounted controls. The machine would be preset for controlled advancement of the pins, which would advance the rails and carriers in the same manner as pins 22 , 32 and 42 of apparatus 10 described above. Optionally, an adapter can be mounted to the table which in turn mounts the apparatus.
In any of the foregoing embodiments of the biopsy apparatus of the present invention, the cannula can include a lumen for injection of drugs or agents to treat or destroy the target and/or surrounding tissue or to inhibit cell proliferation. The lumen can be a separate tube in the cannula, formed integral with the cannula or be the same lumen which contains the rails. Types of materials which can be injected include, for example, chemotherapeutic agents, cryogenic material, ablation fluid, heating fluid, etc. These materials can be delivered to the target region either before, after or during specimen removal.
Imaging
FIG. 36 illustrates an embodiment of the apparatus which utilizes ultrasound to help guide and visualize the apparatus during insertion and use. Apparatus 500 is identical to apparatus 200 in all respects, except for the provision of ultrasonic transducer 501 (shown in phantom), and is therefore provided with corresponding reference numerals in the “500” series, Transducer 501 is positioned at the distal end of the apparatus 500 , and is wired to a conventional power supply S. The wire extends inside cannula 512 and exits the proximal end of handle portion 514 as shown. Monitor screen M is wired to power supply S to enable viewing via ultrasound of the surgical site.
Currently, as is known, low ultrasound frequency provides increased ability to see a greater distance but at the expense of resolution. Conversely, high frequency provides greater (clearer) resolution but with a decreased ability to see distances. Thus, typically, since the ultrasound probe is placed outside the breast tissue, at a distance from the lesion, it must be used at a low frequency to ensure the lesion can be viewed. However, resolution suffers and difficulty in detecting the boundaries of the lesion could occur. Lower resolution also decreases the chances of detecting calcium which is often an indicator of the presence of abnormal growths, i.e. tumors. For this reason, the breast tissue is often compressed between compression plates to shorten the distance from the probe outside to the breast to the lesion. However, compression of the breast adds an additional step to the procedure and could distort the image and result in inaccurate lesion removal, especially if the lesion site is marked in a non-compressed condition of the breast.
In the apparatus 500 , by placing the transducer at the end of the apparatus, the distance from the lesion is greatly reduced. This allows a higher frequency to be used which provides greater resolution and an increased ability to detect calcium. Also, by placement of the distal end of the instrument, the surgeon can view the lesion in an orientation aligned with the cannula, also facilitating vision.
It should be understood that the use of a transducer at the tip of the instrument can be used in other biopsy devices.
While the above description contains many specifics, those specifics should not be construed as limitations on the scope of the disclosure, but merely as exemplifications of preferred embodiments thereof. For example, the inner and outer rails can be reversed so that the set of rails which extends to encapsulate the lesion is positioned outside instead of inside, the initially deployed set of rails. Also, the cutting wire could be positioned outside rather than inside the rails. Additionally, although described for use for breast biopsy, the apparatus can be used to excise tissue in other areas of the body and in other surgical procedures. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the disclosure as defined by the claims appended hereto.
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A surgical biopsy apparatus for cutting tissue comprising a housing having a longitudinal axis, first and second members movable from a retracted position to an extended position with respect to the housing, a third member slidably positioned and extendable with respect to the first member, a fourth member slidably positioned and extendable with respect to the second member, and an electrocautery cutting wire slidable with respect to the third and fourth members to surround a region of tissue positioned between the third and fourth members to cut the tissue.
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BACKGROUND
In the use of elevated platforms for supporting people and/or cargo, it is generally desirable to provide a protective enclosure for confining the people and/or cargo on the supporting surface of the platform. Platform lifting machines, such as mobile lift mechanisms, having platforms which are vertically elevated, are known in the art and are provided with railing structures to confine the people on the platform. It is desirable for such railings to be positioned at a sufficient height above the edges of the platform to inhibit people from falling from the platform. It is also desirable for the railing to be sufficiently high and rigid to withstand and restrain outward forces applied to the railing, for example, when people lean against the railing.
Platform lifting machines are used at a wide variety of applications in buildings, particularly office and government buildings. The platform lifting machines are frequently transported to different areas in the buildings through door ways having limited vertical clearance or from floor to floor on freight elevators having limited access openings. When moving the lift mechanism from one area to another, the height of the platform lifting machine must be less than the vertical clearance of the door frame or other opening between areas. The presence of a railing or other protective structure above the perimeter of the platform contributes significantly to the overall height of the lifting machine. In order to provide the ability to reduce the height of the platform lifting machine for the purpose of passing through doorways and other limited access openings, lifting machines have been designed with various types of collapsible or removable railings, such as inwardly or outwardly folding railings, telescoping railings, or completely removable railings.
All of the prior art attempts to reduce the height of lifting machines have not produced satisfactory solutions and all have possessed distinct disadvantages. For example, in the use of removable railings, workers using the lifting machine may neglect to replace the railing on the platform or may improperly fit parts together prior to using the lift machine. Railings which fold inwardly or outwardly relative to the platform area have been found to be awkward to use by persons standing upon the platform. Additionally, folding railings and telescoping railings have relied upon removable fasteners, such as removable lock pins, in order to secure the railings in a desired position. As in the use of removable railings, workers using such lifting machines, may neglect to replace the locking pins, thereby being exposed to the risk of injury because the railing is not secure to prevent falling from the platform.
It would be desirable to provide a protective railing structure for platform lifting machines that would be easy to reduce in height when desired and would be conducive to easy and safe replacement to its protective position when the platform is in use. It would also be desirable to provide a protective railing structure that would be particularly resistant to failure when receiving the force of a person falling against the railing while using the platform.
SUMMARY
In accordance with the present invention, an elevated platform apparatus, such as a mobile platform lifting mechanism, is provided with a folding rail arrangement for allowing the height of the platform lifting mechanism to be reduced without compromising the safety provided by a protective railing structure. The folding rail arrangement includes a plurality of link members pivotally connected relative to the platform and pivotally connected with a railing assembly. The link members permit movement between the railing assembly and the platform for moving the railing assembly between lowered position and an elevated position relative to the platform. One or more latch members are connected with the link members in order to secure the railing assembly in the elevated position. The latch members are guided between the elevated and lowered positions of the railing assembly by locking members, which are received in guide slots in the latch members. As the railing assembly is moved to its elevated position, the link members are rotated and the latch members are guided to their locking position with the locking members to hold the railing assembly locked in the elevated position. A spring is connected with the latching member to urge the latching member into its locked engagement with the locking member. A lever is provided on the latch member to facilitate ease of disengagement of the latch member from the locking member for moving the railing assembly to its lowered position.
BRIEF DESCRIPTION OF THE FIGURES
The foregoing summary, as well as the following detailed description of the preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings in which:
FIG. 1 is a perspective view of a mobile platform lifting machine having an adjustable rail assembly in accordance with the invention;
FIG. 2 is a perspective view of a portion of the adjustable rail assembly with parts broken away from the platform and railing assembly;
FIGS. 3a and 3b are side elevational views of the platform and railing assembly of FIG. 1 showing the adjustable rail assembly in respective elevated and lowered positions;
FIGS. 4a and 4b are side elevational views of an alternative embodiment of the latching arrangement between the platform and railing assembly of FIG. 1 and showing the railing assembly in respective elevated and lowered positions;
FIG. 5 is a side elevational view of another alternative latching arrangement between the platform and railing assembly; and
FIG. 6 is a side elevational view of a mobile platform lifting machine having an alternative adjustable railing configuration.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a platform lifting machine generally designated 10. The lifting machine 10 includes a base or chassis 12, which provides mobility for the machine. Wheels 14 are attached to the chassis 12, and at least one of the wheels is driven by a suitable motor (not shown), for providing the ability to easily move the machine 10 from one location to another. A lifting mechanism generally designated 16 is mounted on the chassis 12 for raising and lowering a platform or work station 18 attached to one end of the lifting mechanism 16. The lifting mechanism 16 can be an articulated boom as shown in FIG. 1 or can be provided by one of many types of known lifting mechanisms, such as a telescoping boom. One type of lifting mechanism is shown and described in U.S. Pat. No. 4,953,666. In other embodiments, the platform 18 may be elevated above the ground by being suspended by any suitable means, such as by ropes anchored from above the ground, elevated booms and the like.
A protective structure, generally designated as railing assembly 20, is positioned above the perimeter of the platform for protecting occupants and/or cargo on the platform from the risk of falling off of the platform. The railing assembly 20 preferably includes an upper side rail 24a and a lower side rail 26a. The upper and lower side rails are rigidly connected together in parallel arrangement by vertical struts 28a, 28b, and 28c. The side rails 24a and 26a serve to restrain people from falling off of one side of the platform 18. Similarly, an upper side rail 24b and a lower side rail 26b are connected together by vertical struts 28d, 28e, and 28f on the opposite side of the platform, as shown in FIG. 1.
At the front end of the railing assembly 20, the upper side rails 24a and 24b are preferably connected by an upper end rail 32a. Similarly, the front ends of lower side rails 26a and 26b are connected by a lower end rail 32b. At the rear end of the railing assembly 20, upper side rails 24a and 24b are preferably connected by an upper end rail 30. A single end rail 30 is employed at the rear end of the railing assembly 20 to facilitate an opening therebeneath to climb aboard the platform, particularly when the railing assembly is positioned as shown in FIG. 1.
In alternative embodiments, the ends of the railing assembly may include gates, chains, or other means (not shown) for selectively allowing or preventing access to the platform 18. In still other embodiments, the ends of the railing assembly may be open, so that the railing assembly consists essentially of two separated protective railing structures above the respective sides of the platform.
The railing assembly 20 is connected to the platform by means of a plurality of adjustable link members designated 34a-f, which are each pivotally connected at one end to the underside of the railing assembly 20. The links 34a-f are pivotally connected at their other ends with respective upstanding posts 36a-f, which are rigidly secured to the sides of platform 18, as shown in FIG. 1. The railing assembly is preferably supported at a sufficient height or elevated position above the perimeter of the platform, so that the upper side rails 24a and 26a are above the general waist level of persons who may work in a standing position on the platform 18. Such a height is desirable to inhibit or prevent people from falling over the top of the railing assembly as they stand and work on the platform. Most specifically, the upper side rails are preferably supported at a height of between 40 inches and 44 inches above the surface of the platform in accordance with the ANSI/OSHA standards relating to these types of elevated platforms. The lower side rails are positioned about halfway between the platform and the upper side rails at a height of between 20 and 22 inches above the platform, when the railing assembly is in its elevated position.
A side panel or skirt 17 is preferably attached to the perimeter of the platform 18. The side panel 17 extends vertically several inches from the periphery of the sides and one end of the platform 18 to prevent a person's foot or cargo from slipping off of the platform.
An example of the adjustment or movement of the link members is shown in greater detail in FIG. 2. A connecting bracket 38 is attached to the underside of the lower side rail 26a. The bracket 38 is welded or otherwise attached to the side rail and extends downwardly. A pivotal connection is formed between the bracket 38 and one end of link 34a, such as by bolt 42 that is secured to the bracket 38 and extends through one end of the link arm 34a. The end of the link arm 34a that is secured to the bracket 38 may be rounded or beveled to facilitate unrestricted rotation of the link arm 34a about the pivot 42. The bracket 38 permits the link arm 34a to be rotated until the link 34a is substantially perpendicular to the lower side rail 26a.
As can be appreciated, the plane of rotation of the link 34a is substantially perpendicular to any outward or inward forces that would be applied to the side rails 24a or 26a by, for example, a person leaning against or falling into the railing assembly 20. Thus, the pivotal joint between the link 34aand the railing assembly is relatively rigid with respect to such forces.
The opposite end of the link 34ais secured by pivot pin 46 to a bracket 44 attached to the upper end of stationary post 36a, which is attached to the platform 18. The pivot connection allows the link 34ato rotate until the link 34ais relatively parallel to the surface of the platform 18. As can be seen in FIGS. 1 and 2, the plane of rotation of the link 34a about pivot 46 is perpendicular to forces that may be applied to the side rails 24a and 26a by a person leaning or falling into them. Also, as can be appreciated, the lower pivot for the link 34a remains stationary relative to the platform 18 as the railing assembly 20 is elevated or lowered. Additionally, the upper pivot 42 is moved relative to the platform along an arc defined by the length of the link 34a.
In alternative embodiments, the pivotal connections between the link 34 and the bracket 38 or between the link 34 and post 36 can be made by other suitable attachment means, such as is well known in the art. The pivotal connection merely needs to allow suitable articulation of the connection between the railing assembly 20 and the platform 18.
Turning now to FIGS. 3A and 3B, there is shown the preferred range of articulation between the railing assembly 20 and the platform 18, the link members connected therebetween providing the ability to elevate or lower the railing assembly 20 in order to reduce the height of the platform lifting machine. In FIG. 3A, the railing assembly 20 is shown in the elevated or raised position. In FIG. 3B, the railing assembly 20 is shown in its lowered position.
A latch assembly, generally designated 51a, is provided in order to lock the link 34b, so that the railing assembly 20 can be secured in its elevated position as shown in FIG. 3A. The latch assembly 51a includes a pivotal latch member 56. The latch member or latch 56 is secured at one end to a bracket 60 mounted upon the link 34b by a suitable pivot pin. The other end of the latch 56 is provided with a generally L-shaped slot 57 having a longitudinal portion 57a and a foot or transverse locking portion 57b. A locking member, such as guide pin 62, extends outward from the side of the platform 18 and is captured within the L-shaped slot 57. The locking member or guide pin 62 preferably has an enlarged head to capture the latch between the lead of the guide pin and the platform. A spring 64 is connected between latch 56 and the platform 18. When the railing assembly 20 is in its elevated position as shown in FIG. 3A, the spring 64 urges the locking pin 62 into the foot 57bof the slot to securely hold or lock the latch in fixed position. With the latch in fixed position under the urging of the spring 64, the link is locked in its vertical position to hold the railing assembly 20 fixed in its elevated position.
A handle or lever 58 is rigidly connected to the latch at 56 one end thereof, as shown in FIGS. 3A & 3B, to allow a person on the platform to easily pivot the latch 56 about the pivot point in bracket 60 to move the distal end of the latch against the bias the spring or locking portion 64, so that the pin can be freed from the foot 57b of the latch guide slot. With the locking pin 62 free of the locking portion of the latch, the railing assembly may be lowered as the locking pin travels in the longitudinal portion 57a of the L-shaped slot. The latch slides along guide pin 62 until the pin 62 hits the end of the longitudinal portion 57a of the slot, as shown in FIG. 3B. In this manner, the railing assembly is moved to its lowered position relative to the platform 18.
In order to raise the railing assembly 20 into the elevated position from the lowered position shown in FIG. 3B, the railing assembly 20 is lifted upward thus rotating the link 34a-c counter-clockwise into a vertical orientation. As the railing assembly is lifted, the latch 56 is guided into position by guide pin 62 within slot 57. When the railing assembly 20 has been lifted into the position shown in FIG. 3A, the bias exerted by spring 64 urges the latch to have transverse or foot portion 57bof the L-shaped slot capture the guide and locking pin 62, so that the railing assembly is latched and rigidly secured in its elevated position.
Referring again to FIG. 1, it can be seen that an additional latch assembly 51b is preferably employed with the link 34e on the opposite side of the platform to provide additional support and rigidity in holding the railing assembly in its elevated position. Furthermore, the additional latch assembly 51b maintains the railing assembly in the elevated position in the event that the latch assembly 51a is inadvertently moved so as to unlatch or unlock the latch assembly 51a while a person is working upon the platform. In embodiments having an additional latch assembly 51b, it should be appreciated that all of the latch assemblies are to be simultaneously actuated to a released condition of locking pin 62 in the foot or locking portion of the latch, when it desired to lower the railing assembly. One skilled in the art will also recognize that the railings on opposite sides of the platform could be raised independently and could be secured in elevated position by independent latch assemblies associated with each railing.
It should be appreciated that latch assembly of the present invention for locking the railing assembly in its elevated position can be embodied in a wide variety of forms to hold the links in upright or vertical position. In one possible alternative arrangement, the lever 58 may be attached to the brace 56 at a location other than that shown in FIGS. 3a and 3b. For example, the function provided by lever 58 may alternatively be provided by a handle or other suitable fixture attached along the length of latch 56 or at the opposite end of the latch, so that the latch 56 for manipulating the latch, as desired.
In FIGS. 4A and 4B, there is a further alternative embodiment for the latch assembly designated 75 therein. The latch assembly 75 in FIG. 4A includes a latch 72 that is pivotally connected at the lower end to the platform 18 by a pivot pin 74. The upper end of the latch 72 has an L-shaped slot formed therein. The L-shaped slot includes a longitudinal portion 77b and a transverse or foot portion 77a, which provides a locking portion when a guide pin 80, which is fixed to a bracket on link 34b, is captured therein. Hence, when the railing assembly 20 is in the elevated position, as shown in FIG. 4A, the guide or locking pin 80 is received in the foot or locking portion 77a of the L-shaped slot and is urged into such position by spring 76 connected between the latch 72 and the platform 18. A handle 78 is attached to the latch 72 for ease of movement of the latch. In order to lower the railing assembly 20, as shown in FIG. 4A, an operator merely raises the handle 78, exerting a force on the latch 72 counter to the bias of spring 76, in order to free the guide or locking pin 80 from the foot or locking portion of the L-shaped slot in the latch 72. The link 34b can then be rotated clockwise to move the railing assembly to its lowered position, as shown in FIG. 4B.
A still further alternative embodiment for the latch arrangement is shown in FIG. 5. In the arrangement of FIG. 5, the link 34b is maintained in its vertical position by an arcuate shaped latch member 85. The link 34b carries a dual-purpose guide and locking pin 82, which is secured to a bracket on the link. The guide pin 82 is captured within a arcuate shaped guide slot 88 formed in the latch 85. The lower end of the arcuate latch 85 is attached to post 36b, which is rigidly secured to the platform 18.
When the link 34 between the railing assembly (not shown) is in the raised or vertical position, the guide or locking pin 82 is captured at the upper end 88a of the slot 88 in the latch 85. In this position, the arc of rotation for pin 82 to permit lowering of the link 34b is not coincident with the arc formed by slot 88 in latch 85, so that the slot of the latch forms a locking angle with the arc of rotation of the locking pin 82. Thus, the link 34b is prevented from rotating about the pivot 46 when the arcuate latch 85 is in the position shown in solid lines in FIG. 5. A spring 84 is connected between the platform 18 and the latch 85 in order to bias the latch 85 to maintain the latch 85 in its locking position with the pin 82 on link 34b to prevent rotation of the link.
As shown in FIG. 5, the upper end of post 34b carries a C-shaped bracket 44 attached by pivot pin 46. The bracket 44 is adapted to prevent clockwise movement of the link from its vertical position shown in FIG. 5, while permitting counterclockwise movement for lowering the railing assembly.
In order to move the railing assembly (not shown) to its lowered position, the latch 85 is moved by its handle 86 in a clockwise direction about pivot 90 against bias of spring 84 to the dotted line position shown in FIG. 5. As the latch is rotated in a counterclockwise direction, the locking pin 82 can be moved within the slot of the latch 85 to permit the link to rotate about pivot 90. As the handle 86 is moved into the position shown in phantom as 86', the brace 85 pivots into the position shown as 85' and the guide pin 82 is guided within the slot 88 until the guide pin 82 reaches the position 82' within the lower end 88b' of the slot. As the guide pin 82 is rotated into the dotted line position 82' indicated in FIG. 5, the link 34b rotates about pivot 46 to reach the position 34b shown in dotted lines to lower the railing assembly, as has been described in connection with the previous embodiments.
In the practice of the present invention, it is not necessary to have the upper and lower side rails of the railing assembly be connected as a unit to be raised and lowered together. For example, in FIG. 6, there is shown a platform lifting machine generally designated 110 having an alternative railing arrangement. In the embodiment shown in FIG. 6, the machine 110 has a platform 118 to which elongated vertical support members 136a-c are rigidly attached. A lower side rail 126 is welded or otherwise secured to the upper ends of the vertical members 136a-c. The lower side rail 126 has brackets 144a-c mounted thereon for pivotally securing the respective lower ends of link members 134a-c thereto. The upper ends of links 134-c are pivotally secured within respective brackets 140a-c, which are mounted along the lower surface of upper side rail 124.
As can be appreciated, the upper side rail 124 in FIG. 6 can be lowered and/or raised relative to the platform 118 by movement of the links about their pivotal connections 144a-c. A latch assembly generally designated 151 is provided in order to selectively lock the links in their upright or vertical position, when the upper side rail is raised. The link assembly 151 has a pivoting latch 156 that is secured to the link 134b by a pivot 160. A guide or locking pin 162 is secured to the lower side rail 126. The guide pin 162 extends outwardly from the lower side rail 126 and is captured within L-shaped slot formed in the latch 156. The manner of operation of latch 151 in conjunction with links 134a-c is similar to that described in connection with the latch 56 of FIGS. 3a and 3b. Since the latch assembly 151 and the link arrangement in FIG. 6 are similar to corresponding parts in FIG. 3, the operation of the corresponding parts in FIG. 6 will not be described again.
The terms and expressions which have been employed are used as terms of description and not of limitation. It will be recognized by those skilled in the art that changes can be made to the above described embodiments without departing from the equivalence of the features shown and described, or inventive concepts expressed herein. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications which are within the scope and spirit of the invention as defined in the appended claims.
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A lifting truck is provided with a folding rail assembly for confining workers to an elevated platform. The folding rail assembly includes a plurality of link members pivotally connected relative to the platform and to a protective railing structure. The link members permit movement of the protective railing structure between a lowered position and an elevated position relative to the platform. One or more latch members are pivotally connected with respective link members for preventing movement of the railing from the elevated position. The latch members are configured to allow the railing to be lifted directly to the elevated position. The latch members comprise handles for exerting an opposing force against the bias of a spring for releasing the latch members to permit the railing to be lowered after use.
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PRIOR APPLICATION
This application claims the benefit of prior Provisional Patent Application Serial No. 60/354,110 filed Feb. 4, 2002.
TECHNICAL FIELD
This invention relates to automatic climate control systems for vehicles, and more particularly to a method of generating control system algorithms that optimize occupant comfort.
BACKGROUND OF THE INVENTION
In an automotive automatic climate control system (ACCS), the driver generally selects a desired cabin temperature, and a microprocessor-based system controller responds in a pre-programmed way to control the blower speed, the air discharge temperature and the air delivery mode. While the driver has the option of overriding the pre-programmed settings, the objective is to design the control algorithms so that the pre-programmed settings sufficiently satisfy the occupants that little or no overriding is necessary. This presents a very difficult challenge to system and calibration engineers because control settings that satisfy the engineers may only satisfy a small subset of the overall population of vehicle occupants. For this reason, and in order to reduce development time, there has been a trend toward increased usage of math-based tools to simulate and analyze system operation, and to compare the performance achieved with different system designs and control approaches. See, for example, the U.S. Patent to Webster et al. U.S. Pat. No. 6,209,794, where mathematical models of a vehicle and thermal management system are utilized to evaluate the impact of different system designs on the time required for the cabin to reach a comfortable temperature.
While math-based tools have the capability of accelerating the validation process and significantly reducing product development time, the fact remains that it is difficult to develop control strategies that satisfactorily address occupant comfort. Even in cases where occupant comfort standards are reasonably well defined, many design iterations are required to develop a control algorithm that will satisfy the defined comfort standards. Accordingly, what is needed is an improved method of applying math-based tools to the control algorithm design process that minimizes the number of design iterations required to arrive at a solution that optimizes occupant comfort.
SUMMARY OF THE INVENTION
The present invention is directed to an improved method of developing optimized control algorithms for a vehicular automatic climate control system (ACCS). According to the invention, math-based models are utilized to simulate the vehicle, the ACCS and the occupant, and the models are cross-coupled in closed-loop fashion with feedback from both vehicle and occupant. A first feedback loop including the vehicle and the ACCS simulates how the ACCS interacts with the cabin environment; and a second feedback loop including the vehicle, the ACCS and the occupant simulates how the occupant will adjust the ACCS to optimize comfort. When the control algorithm satisfies the control objectives and optimizes occupant comfort, an auto-code generation tool is used to create program code directly from the control model, which may be downloaded into a test vehicle for final system confirmation and calibration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the simulation of a vehicle, its automatic climate system and its occupants according to this invention, along with automatic code generation tools for transferring simulated control algorithms to a physical automatic climate control system in an actual vehicle.
FIG. 2 depicts a visual interface of a control head model of a simulated automatic climate control system according to this invention.
FIG. 3 is a block diagram of a simulated automatic climate control algorithm according to this invention.
FIG. 4 is a block diagram of a simulated vehicle climate control plant according to this invention.
FIG. 5 is a block diagram of a human comfort reaction model according to this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the method of the present invention in the context of a conventional motor vehicle automatic climate control system (ACCS) 10 including two electronic control units (ECUs): a climate control system (CCS) ECU 12 , and a control head (CH) ECU 14 . In vehicle operation, the CCS ECU 12 interacts with the CH ECU 14 , receives various inputs 16 pertaining to ambient conditions and actual cabin temperature, and produces various outputs, including command signals for a compressor clutch (CL) 18 , a condenser fan (CF) 20 , a blower motor (BM) 22 , and a number of air control doors actuators (ACDA) 24 . The CH ECU 14 resides in a user interface, generally referred to as a control head, whereby the driver or other occupant can set the desired cabin temperature and manually override the control settings of the blower motor 22 and air control doors 24 . The CH ECU 14 can also display data received from CCS ECU 12 , such as the outside temperature. Of course, the CCS ECU 12 and the CH ECU 14 may be combined into a single ECU if desired.
In carrying out the above-mentioned control functions, the CCS ECU 12 and the CH ECU 14 each have embedded control algorithms that are periodically executed by an internal microprocessor. Such algorithms are ordinarily developed by systems engineers, and converted into suitable program code for storage in non-volatile memory within the respective ECU. The vehicle is then subjected to a fairly rigorous testing regimen, during which the control algorithms are adjusted and calibrated to optimize system performance, which may be defined in terms of transient performance, steady-state temperature regulation, and occupant comfort, for example. However, the present invention contemplates a totally different control algorithm development methodology in which the control algorithms for CCS ECU 12 and CH ECU 14 are generated off-line in a simulation environment defined by various interlinked mathematical models, designated generally in FIG. 1 by the reference numeral 26 . These models include a control head model (CHM) 28 , a climate control system model (CCSM) 30 , a vehicle plant model (VPM) 36 , a thermal comfort model (TCM) 40 , and a comfort reaction model (CRM) 42 . The automatic code generation (ACG) units 32 and 34 link the simulation environment models 26 to ACCS 10 by generating program code for CH ECU 14 and CCS ECU 12 based on the functionality of CHM 28 and CCSM 30 , respectively. The simulation environment models 26 are implemented with a mixture of commercially available software tools and custom developed applications. The ACG units 32 and 34 produce C code from the transfer functions of CHM 28 and CCSM 30 ; the ACG unit 32 can be implemented using the DeepScreen tool developed and marketed by Altia Inc., and the ACG unit 34 can be implemented with the Real Time Workshop Embedded Coder developed and marketed by The MathWorks Inc.
In general, CCSM 30 interacts bi-directionally with VPM 36 , which simulates the mechanical and thermal response of the vehicle to ambient conditions and the outputs of CCSM 30 . For example, VPM 36 supplies information concerning the simulated compressor speed, cabin air temperature and engine coolant temperature to CCSM 30 , and CCSM 30 supplies information concerning the simulated air control door positions, blower motor speed, and compressor clutch state to VPM 36 . The VPM 36 supplies simulated cabin environment information (such as air discharge temperature, air velocity, and air delivery locations) to an occupant model 38 that comprises TCM 40 and CRM 42 . The TCM 40 simulates comfort levels for various body segments (torso, arms, legs, head, etc.) of the occupants, and the CRM 42 , in turn, simulates how the occupants will adjust the user inputs (desired temperature, blower motor speed, and air delivery mode) of the CHM 28 to maximize comfort. Thus, there is a first feedback loop including VPM 36 and CCSM 30 simulating how the climate control system interacts with the cabin environment, and a second feedback loop including CCSM 30 , CHM 28 , VPM 36 , TCM 40 , CRM 42 simulating how the occupant will adjust the climate control system to optimize comfort. Additionally, the comfort optimization module (COM) 44 adjusts the calibration parameters of CCSM 30 , as shown. The simulated adjustments supplied to CHM 28 and CCSM 30 produce corresponding adjustment of the simulated control algorithms for CHM 28 and CCSM 30 until the control algorithms produce a simulated vehicle environment that satisfies the occupant model 38 , obviating further adjustment of the user inputs of CHM 28 . At such point, the ACG units 32 , 34 create program code corresponding to the CCSM and CHM control functions, which is compiled and downloaded into CCS ECU 12 and CH ECU 14 for final in-vehicle validation and calibration.
The CHM 28 is implemented with the Altia Design/FacePlate software package developed and marketed by Altia Inc., and includes a visual interface, generally designated by the reference numeral 50 in FIG. 2 . Referring to FIG. 2, the button pair 52 controls the driver set temperature, the button pair 54 controls the blower speed, the button pair 56 control the air discharge mode, and the buttons 58 and 60 activate full cold and hot settings with cabin air recirculation. Additionally, the buttons 62 and 64 activate defrost and rear defog functions, and the display panel 66 provides visual feedback to the occupants. Behind the graphical interface is logic that decodes the activation of the buttons 52 - 64 into commands for CCSM 30 and occupant feedback via indicators on display panel 66 . In many cases, the decode logic may affect several system operations; for example, when the Defrost button 62 is activated, the mode override is set to deliver air to the windshield, the air inlet door commanded to a position for introducing outside air, and the refrigerant compressor is activated to de-humidify the discharge air.
The CCSM 30 is implemented with the MatLab software package (MatLab, Simulink, StateFlow) developed and marketed by The MathWorks Inc. Essentially, the MatLab software package acts as a backplane, providing easy interfacing with the VPM 30 and the occupant model 38 . The model describes a desired transfer function, and becomes an executable specification which ACG 34 converts into C program code. Functionally, the control algorithm carried out by CCSM 30 includes a transient phase during which the initial cabin air temperature transitions to a set temperature TSET, and a steady-state phase during which the cabin air temperature is maintained at TSET while the vehicle is subjected to various ambient temperature and solar conditions. FIG. 3 depicts a high level block diagram of CCSM 30 ; in practice, each of the depicted blocks is further defined by a set of sub-blocks, which can be further defined by another set of sub-blocks until the function is completely described using the primitive blocks of Simulink or custom defined blocks.
Referring to FIG. 3, CCSM 30 includes a temperature controller (TC) 70 , an inlet air controller (IAC) 72 , a mode controller (MC) 74 , and a blower controller (BC) 76 for implementing an automatic climate control algorithm. Interaction between the blocks 70 - 76 can be seen via the various connecting signals. For example, TC 70 develops a temperature blower speed TBS which is provided to BC 76 along with a blower speed request (BSR) from CHM 28 , and BC 76 selects a blower speed target BSTAR based on the two inputs. The TC 70 also develops a temperature related inlet air request IATRQ, which is provided to IAC 72 along with a RECIRC request from CHM 28 , and IAC 72 selects an inlet air door position delta based on the two inputs. A vehicle communications block (VC) 78 simulates interaction with other vehicle controllers, allowing CCSM 30 to control the air conditioning compressor (CRQ) and shared devices such as engine cooling fans, and to receive shared sensor data such as engine speed, vehicle speed, battery voltage, and coolant temperature CT. The user interface block (UI) 80 permits data sharing between CCSM 30 and CHM 28 , and the input and output processing blocks (IP, OP) 82 , 84 permit data sharing between CCSM 30 and VPM 36 . For example, UI 80 receives inputs concerning rear defogger RDef, air conditioning enable/disable ACRQ, occupant set temperature requests OSTR, cabin air recirculation RECIRC, occupant air delivery mode requests OMR, and occupant blower speed requests OBSR. The input processing block 82 receives data from VPM 36 concerning the discharge air temperature Tair, the evaporator outlet air temperature Tevap, the cabin air temperature Tcabin, the temperature door position TDP, the mode door position MDP, and the air inlet door position IADP. Similarly, the output processing block 84 provides data to VPM 36 concerning the target blower speed BSTAR, and position deltas TDD, IADD, MDD for the temperature, air inlet and mode doors.
In general, the VPM 36 simulates the performance of the air conditioning system, and develops data pertaining to the discharge air velocity, delivery locations, and temperatures. The VPM 36 is implemented using the EASY5 Simulation package developed by Boeing Corporation and the computational fluid dynamics (CFD) package developed by Fluent Inc., and includes a model of the transient behavior of an air conditioning (AC) system. The transient AC model is illustrated by the block diagram of FIG. 4, and includes five main components: a refrigerant compressor 100 , a condenser 102 , and orifice tube 104 , an evaporator 106 , and an accumulator 108 .
The compressor model 100 receives inputs pertaining to accumulator output vapor flow on line 110 and the compressor drive speed (CS) on line 112 , and implements empirically determined isentropic efficiency and volumetric efficiency maps characterizing a particular compressor design. The refrigerant flow rate output RFRcomp is calculated according to:
RFRcomp=Vd*CS*VE*Ds
where Vd is the compressor displacement, VE is the volumetric efficiency, and Ds is the density of the inlet refrigerant. The compressor work is calculated based on the outlet pressure, the state point of the inlet refrigerant, and the isentropic efficiency (which can be empirically determined).
The condenser and evaporator models 102 , 106 each receive inputs pertaining to refrigerant flow and the respective airflows (COND_AIRFLOW, EVAP_AIRFLOW), and describe the refrigerant outlet state. The models comprehend the geometries of the respective devices (tube lengths, heat transfer areas, etc.), and the refrigerant-side and the air-side heat transfer coefficients, and maintain a transient energy balance between the refrigerant-side and the air-side. The evaporator model 106 additionally comprehends the formation of condensate and its impact on heat transfer.
The orifice tube model 104 predicts the refrigerant flow rate m_dot given the upstream state and the downstream pressure, and can be implemented as follows:
m — dot=C tp *A s [2 *g*D i ( P up −P f )] 1/2
where C tp is a two-phase quality correction factor, A s is the cross-sectional area, D i is the inlet refrigerant density, P up is inlet refrigerant pressure, and P f is the adjusted downstream refrigerant pressure.
The TCM 40 is implemented by custom application software, and includes sub-models that simulate the occupant thermal environment and human physiology. The occupant thermal environment sub-model is implemented with Fluent's CFD software, and simulates the vehicle cabin, taking into account solar loading and radiation heat exchange between the cabin and the occupant. Solar loading increases occupant and cabin temperatures, and varies with the transmission properties of the cabin glass, the solar angle and intensity and the solar spectrum. The heat flux due to solar radiation is modeled by separately considering the short-wave radiation which is absorbed based on skin or clothing absorptance, and long-wave radiation which is absorbed based on skin or clothing emittance. Radiation heat transfer between the cabin and the occupant is calculated using an explicit 3-D occupant model defined by the Stefan-Boltzmann law. The CFD software computes view factors characterizing the radiation heat transfer between the cabin surfaces and the various body segments of the occupant. The occupant thermal environment sub-model divides the cabin into finite volumes, and Reynolds-averaged Navier-Stokes equations for the various volumes are solved simultaneously with a conservation of energy equation to predict airflow, temperature and humidity distribution around the occupants. The human physiology sub-model, in turn, calculates the thermal responses of various body segments in terms of skin and core temperatures. In the illustrated embodiment, the simulated occupant is divided into sixteen body segments consisting of clothing and defined layers (core, muscle, fat and skin tissue), and a vascular model dictates convective heat transfer among the various segments. The portion of each segment that is in contact with an interior surface of the cabin is specified, and as mentioned above, radiative heat transfer between the cabin surfaces and the various body segments is computed by the CFD view factors. The output is in the form of Equivalent Homogeneous Temperature (EHT) data for each of the sixteen body segments, and if desired, the model may be expanded to include the effects of humidity on occupant comfort. A more detailed description of the modeling techniques is set forth, for example, in the SAE Paper No. 2001-01-0588 authored by Han, Huang, Kelly, Huizenga and Hui, and entitled Virtual Thermal Comfort Engineering.
The CRM 42 receives the EHT data developed by TCM 40 , as well as the air discharge location and velocity data, and creates a discomfort function (DF) based on deviations in the EHT data from optimal EHT values. When the discomfort function reaches at least a certain level, CRM 42 reacts by proportionately adjusting one or more of the manual override settings of the CHM 28 . While the blower speed or mode overrides occur without delay, some time is required to change the temperature of the cabin, and the CRM 42 models human patience so that the controls are not adjusted too frequently.
In general, the functionality of CRM 42 is illustrated by the block diagram of FIG. 5, where the blocks 120 - 126 cooperate to determine the occupant requests (OMR, OSTR, OBSR) for air delivery mode, set temperature, and blower speed. The block 120 is responsive to the EHT data developed by TCM 40 , and determines an overall or cumulative discomfort indication according to the deviation of the EHT data from optimal EHT values. The block 122 evaluates the overall occupant discomfort data, along with the air discharge location data (AD_LOC) developed by VPM 36 , and determines if the air delivery mode could be adjusted to improve the comfort at one or more of the predefined body segments for which EHT data is available. Similarly, the block 124 evaluates the overall occupant discomfort data, and determines if the set temperature could be adjusted to improve the comfort at one or more of the predefined body segments for which EHT data is available. And finally, the block 126 evaluates the overall occupant discomfort data, along with the air velocity data (AIR_VEL) developed by VPM 36 , and determines if the blower speed could be adjusted to improve the comfort at one or more of the predefined body segments for which EHT data is available. Also, the CRM 42 could be expanded to model reaction to windshield fogging, system noise (due to blower speed and air discharge location, for example), and so on, to enhance its simulation of human system overrides.
At the same time, COM 44 reacts to the discomfort function DF by adjusting one or more calibration parameters of the climate control algorithm modeled by CCSM 30 . These parameters may include both transient phase parameters (i.e., those parameters that govern the transient response of the system) and steady-state parameters (i.e., those parameters that govern the steady-state response of the system). The COM 44 averages the discomfort function DF over both the transient and steady-state phases of a simulation run, so that the averaged discomfort function (DF_AVG) can be considered as a function of both the transient and steady-state calibration parameters. A multi-dimensional optimization method (such as the Conjugate Gradient method) is then used to find a set of calibration values that will optimize (minimize) DF_AVG, and COM 44 applies such set of calibration values to CCSM 30 .
While the process of adjusting the algorithm calibration parameters has been described above as an automatic function performed by COM 44 , it will be recognized that the adjustments can alternatively be carried out manually by a calibration engineer, if desired. For example, if the transient response of the simulation is unsatisfactory, the calibration engineer can manually adjust the transient calibration parameters and re-start the simulation to see if the transient performance is improved. However, it should also be recognized the ability of the optimization method (whether manual or automatic) to minimize occupant discomfort is constrained by the control strategy of the climate control algorithm modeled by CCSM 30 . In other words, if the control strategy is flawed, optimization of its calibration parameters may still fail to produce the desired occupant comfort levels. In such case, the control algorithm strategy must be re-visited and modified by system engineers, after which the above-described methods can be utilized to optimize the modified algorithm.
In summary, the present invention provides a radically new methodology for generating improved automatic climate control system algorithms on a significantly abbreviated timetable and with significantly reduced cost, compared to conventional approaches. While described in reference to the illustrated embodiment, it is expected that various modifications in addition to those mentioned above will occur to those skilled in the art. For example, a greater or lesser number of factors can be modeled, different software tools can be utilized to model the various functional blocks, and so on. Thus, it will be understood that methods incorporating these and other modifications may fall within the scope of this invention, which is defined by the appended claims.
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Optimized control algorithms for a vehicle automatic climate control system (ACCS) are developed using math-based models of the vehicle, the ACCS and a vehicle occupant. The models are cross-coupled in closed-loop fashion with feedback from both vehicle systems and occupant. A first feedback loop including the vehicle and the ACCS, simulates how the ACCS interacts with the cabin environment; and a second feedback loop including the vehicle, the ACCS and the occupant, simulates how the occupant will adjust the ACCS to optimize comfort. When the system arrives at a control algorithm that satisfies control objectives and optimizes occupant comfort, an auto-code generation tool is used to create program code directly from the control model, which may be downloaded into a test vehicle for final system confirmation and calibration.
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FIELD OF THE INVENTION
This invention relates generally to separation processes and more specifically to processes for the separation of particulate material from the effluent of a vapor stream recovered from a fluidized particle contacting arrangement.
BACKGROUND OF THE INVENTION
A good example of a fluidized particle contacting process is the fluidized catalytic cracking of hydrocarbons. The fluidized catalytic cracking of hydrocarbons is the mainstay process for the production of gasoline and light hydrocarbon products from heavy hydrocarbon charge stocks such as vacuum gas oils or residual feeds. Large hydrocarbon molecules associated with the heavy hydrocarbon feed are cracked to break the large hydrocarbon chains or ring structures thereby producing lighter hydrocarbons. These lighter hydrocarbons are recovered as product and can be used directly or further processed to raise the octane barrel yield relative to the heavy hydrocarbon feed. The basic equipment or apparatus for the fluidized catalytic cracking of hydrocarbons has been in existence since the early 1940's and, along with its method of operation, is well known to those skilled in the art of hydrocarbon processing.
The cracked products from an FCC reaction section are first separated from the particulate material by disengagement in a reactor vessel or by any other primary separation device followed by passage of the vapor stream through at least one secondary separator to remove the majority of any entrained particulate material. The separated vapors are then delivered directly to product separation facilities associated with the FCC unit. These separation facilities include a primary separator, often referred to as a main column, and a compression section containing numerous separators and contactors for further separating overhead vapors from the main column. The compression section is commonly referred to as the gas concentration section. Invariably the vapors passing to the product separation facilities will contain a small quantity of the most fine particulate material that also enters the product separation facilities.
Routinely in the prior art, as shown by U.S. Pat. Nos. 3,849,294; 3,458,691; 4,003,822 and 3,042,196, the primary separator or the main column separates the remaining heavier fractions into product streams such as gasoline and other distillates, into other heavier streams for recovery and/or other processing such as light cycle oil and heavy cycle oil, and into a bottom stream that is ordinarily recycled to the reaction zone. Entrained fine particles collect in the heavy bottom stream. As shown by the above-cited references, a settler ordinarily concentrates the catalyst particles into a slurry that also passes back to the reaction zone. The return of the solids concentrated from the main column bottoms in a separator or other device tends to increase the concentration of solids in the circulating hydrocarbons that circulate in a recycle loop from the reactor through the main column bottom and back to the reactor. The solids eventually escape from the reactor recycle loop by passing in small quantities through the stripper and finally to the regenerator. The most fine particles tend to remain confined in the circulation loop on the reactor side of the process due to the tendency of the lighter particles to remain with the products carried overhead by the reactor cyclones. This type of circulation can result in solids equilibrating in the reactor--main column recycle loop of the process and causing a threefold increase in the solids concentration before the trapped fine particles exit the process via the regenerator and flue gas system. The three pass average for the circulation of fine catalyst particles through the slurry circuit before escaping the process aggravates erosion and plugging problems in the slurry circuit and often overloads any filtration systems that employed to concentrate the solids for recovery and recycle. Today's practice of closing the cyclone and other reactor systems for vapor containment the problems of excessive fine particle recycle in the slurry system by the increasing concentration of solids in downstream cycle separators.
Other prior art systems have been known that recover the fine catalyst particles in a different manner for return to the reaction side of the process. U.S. Pat. No. 2,859,175 shows a system wherein the solids are recovered from a main fractionator and passed back to the top of a dense bed that holds catalyst for passage to a reaction zone. The '175 system provides no way for the fine particles to escape from the dense bed that supplies the catalyst to the reaction zone without first passing the fines again through the fractionator. Some of the very early FCC U.S. Pat. No. 2,687,988 did not need to consider the recirculation of fines in any manner separate from the general recirculation of the catalyst.
BRIEF DESCRIPTION OF THE INVENTION
This invention is an improvement in a system and apparatus for the recovery of fine solid particles that enter the slurry system of a fluidized catalytic contacting process. Suitable fluidized contacting units generate a fluid stream containing a fine particulate material from which fluid components are recovered and fine particulate material is returned to the contacting system for eventual withdrawal from the process through a regeneration system that rejuvenates the solid particulate material. In a specific form, the invention recovers fine particulate material from an FCC main column and returns the particulate material to an FCC stripper to reduce the amount of fine material that continues to recycle through the FCC reactor and product separator. By returning fine particulate material from the FCC product separation zone directly to a low velocity area of the stripping section, the invention breaks the reactor--main column recycle loop that concentrates the fines. Fines entering the reactor stripper will not be carried back into the cyclones for unwanted return to the main column. The FCC stripper provides a particularly advantageous place for injection of the slurry or other recycle that contains the catalyst fines since it will tend to hold the fines in the bed and the low superficial gas velocity through the bed will make reentrainment or elutriation difficult. By the recycling of fines to the stripper via this invention, the fines concentration in the slurry system can decrease by up to 300%.
Reducing the recycling of fines back to the riser can minimize several negative effects. Contacting the hot, clean catalyst in the riser with the heavy oil that typically carries the recovered solids increase the production of light gases, often referred to as non-condensable or dry gas, and reacts the heavy oil into the coke that deposits on the catalyst. The elevated reaction potential of the hot regenerated catalyst raises the production of gas and coke from the heavy oil containing the particles. Whether the heavy oil comprises slurry oil, heavy cycle oil, light cycle oil, or naphtha, recycling the fines to the stripper exposes the heavy oil to cooler temperatures and less active catalyst. Therefore, greatly reduced reaction potential results in the benefits of producing less reaction coke and dry gas.
Recycling hydrocarbons with the fines directly to the stripper can result in the carryover of heavy hydrocarbons into the regenerator. Several methods are available to minimize such carryover of the effect of such carryover. One such method is the use of light cycle oil instead of heavy cycle oil or main column bottoms to carry the solids from any recovery system in the product separation system back to the stripper. The light cycle oil will tend to vaporize easier than the heavier materials and will, therefore, minimize the potential for hydrocarbon carryover into the regenerator with the resulting production of relatively less coke. A typical FCC slurry system will ordinarily contain filters or other methods to concentrate the solids for return to the reaction zone. Additional concentrators can minimize the needed hydrocarbon for injection of fines into the stripper. The particularly preferred concentrator would be a hydroclone for receiving the recycled fines in a hydrocarbon vehicle and further separating hydrocarbons to additionally concentrate the fines and minimize the carrier liquid. Any carryover of heavy hydrocarbons or production of additional coke will not impose any significant problems for systems that are designed to handle heavy residual feedstocks or other heavy hydrocarbon feedstreams since such processes ordinarily have systems for removing the excess heat evolved by the combustion of additional coke.
Accordingly, in one embodiment this invention is a process for the production and separation of a fluidized catalytic cracking product stream that contains fine catalyst particles. The process passes an FCC feedstock and regenerated catalyst particles to a reaction zone to convert the feedstock. The process separates catalyst particles from gaseous hydrocarbons and recovers an FCC product stream containing fine catalyst particles and passes the separated particles to a relatively dense bed. A fractionation zone that receives the product stream further separates the product stream into at least a relatively light hydrocarbon stream and a relatively heavy hydrocarbon stream. A particle recycle stream containing the fine catalyst particles and at least a portion of the relatively heavy hydrocarbon stream is recovered and injected into a relatively dense bed at an injection point. The process withdraws a coked catalyst stream comprising at least a portion of the relatively fine particles from the relatively dense bed at a location below the injection point and passes the coked catalyst stream to a regeneration zone. The regeneration zone combusts coke from the catalyst particles to generate flue gas that passes out of the regeneration zone and carries entrained fine catalyst particles therewith while supplying regenerated catalyst to the reaction zone.
Other objects, embodiments and details of this invention can be found in the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of a primary separator, an FCC reaction zone, and an FCC regeneration zone.
FIG. 2 is a modified schematic flow diagram of a primary separator, an FCC reaction zone, and an FCC regeneration zone of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The process and apparatus of this invention is described in the context of the drawings. Reference to the specific configuration shown in the drawings is not meant to limit the process of this invention to the particular details of the drawing disclosed in conjunction therewith. The drawings are schematic representations and omit many of the valves, instruments, pumps and other equipment associated with the arrangement of this invention when unnecessary for an understanding of the invention.
The FCC process will employ a wide range of commonly used catalysts which include high activity crystalline alumina silicate or zeolite containing catalysts. Zeolite catalysts are preferred because of their higher intrinsic activity and their higher resistance to the deactivating effects of high temperature exposure to steam and exposure to the metals contained in most feedstocks. Zeolites are usually dispersed in a porous inorganic carrier material such as silica, aluminum, or zirconium. These catalyst compositions may have a zeolite content of 30% or more. Particularly preferred zeolites include high silica to alumina compositions such as LZ-210 and ZSM-5 type materials. Another particularly useful type of FCC catalysts comprises silicon substituted aluminas. As disclosed in U.S. Pat. No. 5,080,778, the zeolite or silicon enhanced alumina catalysts compositions may include intercalated clays, also generally known as pillared clays.
Feeds that may be used in conjunction with this invention include conventional FCC feedstocks or higher boiling hydrocarbon feeds. The most common of the conventional feedstocks is a vacuum gas oil which is typically a hydrocarbon material having a boiling range of from 650-1025° F. and is prepared by vacuum fractionation of atmospheric residue. Such fractions are generally low in coke precursors and heavy metals which can deactivate the catalyst. This invention may also be used in the cracking of heavier or residual feedstocks and any description of this invention as useful for the FCC process is not meant to exclude its application to processes for treatment of non-conventional feeds. Heavy or residual charge stocks are those boiling above 930° F. which frequently have a high metals content and which usually cause a high degree of coke deposition on the catalyst when cracked. Both the metals and coke deactivate the catalyst by blocking active sites on the catalyst. Coke can be removed, to a desired degree, by regeneration and its deactivating effects overcome. Metals, however, accumulate on the catalyst and poison the catalyst by fusing within the catalyst and permanently blocking reaction sites. In addition, the metals promote undesirable cracking thereby interfering with the reaction process. Thus, the presence of metals usually influences the regenerator operation, catalyst selectivity, catalyst activity, and the fresh catalyst make-up required to maintain constant activity. The contaminant metals include nickel, iron and vanadium. In general, these metals affect selectivity in the direction of less gasoline and more coke. Various metal management or treatment procedures are known by those skilled in the art when processing such heavy or refractory feeds.
Looking then at FIG. 1, the FCC arrangement has a regeneration vessel 10, a reactor 12, located to the side and above the regenerator, and a stripping vessel 14 located directly below the reactor. A regenerated catalyst conduit 16 transfers catalyst from the regenerator through a control valve 23 and into a riser conduit 20 where it contacts hydrocarbon feed entering the riser through hydrocarbon feed conduit 18. Conduit 18 may also contain a fluidizing medium such as steam which is added with the feed. Expanding gases from the feed and fluidizing medium convey catalyst up the riser and into internal riser conduit 22. As the catalyst and feed pass up to the riser, the hydrocarbon feed cracks to lower boiling hydrocarbon products.
Riser 22 discharges the catalyst and hydrocarbon mixture through the opening of riser outlet 44 to effect an initial separation of catalyst and hydrocarbon vapors. Outside of outlet 44, a majority of the hydrocarbon vapors continue to move upwardly into the inlet of cyclone separators 46 which effects a near complete removal of catalyst from the hydrocarbon vapors, except for catalyst fines to which this invention is directed. Separated hydrocarbon vapors exit reactor 12 through an overhead conduit 48 while a dip leg conduit 50 returns separated catalyst to a lower portion of the reactor vessel. Catalyst from riser outlets 44 and dip leg conduit 50 collects in a lower portion of the reactor forming a bed of catalyst 52.
Bed 52 supplies catalyst to stripping vessel 14. A line 66 injects a hydrocarbon stream containing a high concentration of fine catalyst particles into an upper portion of bed 52. Steam entering stripping vessel 14 through a conduit 54 is distributed by a ring 55 and rises countercurrent to a downward flow of catalyst through the stripping vessel thereby removing sorbed hydrocarbons from the catalyst which are ultimately recovered with the steam by cyclone separators 46. The rising stripping gas produces a superficial gas velocity through the stripping zone that is less than 1 ft/sec and more typically less than 0.5 ft/sec. The low superficial velocity maintains a relatively dense bed with an overall catalyst density in a range of from 20 to 50 lb/ft 3 and more often in the range of 35 to 45 lb/ft 3 . In order to facilitate hydrocarbon removal, a series of downwardly sloping baffles 56 are provided in the stripping vessel 14. A spent catalyst conduit 58 removes catalyst including a high proportion of the catalyst fines injected from conduit 66 from a lower conical section 60 of stripping vessel 14. A control valve 61 regulates the flow of catalyst from conduit 58 into a dense bed 35 of regenerator 10.
Regeneration gas, such as compressed air, enters regenerator 10 through a conduit 30. An air distributor 28 disperses air over the cross-section of regenerator 10 where it contacts spent catalyst in bed 34 having an upper bed level 35. Coke is removed from the catalyst by combustion with oxygen entering from distributor 28. Combustion by-products and unreacted air components rise upwardly along with entrained catalyst through the regenerator into the inlets of cyclones 26. A gas relatively free of large catalyst particles, but containing a majority of the catalyst fines, collects in an internal chamber 38 which communicates with a gas conduit 40 for removing spent regeneration gas from the regenerator and the catalyst fines of this invention from the process. Separated catalyst from the cyclones drops from the separators through dip leg conduits 42 and returns to bed 34.
From the vapor outlet of the reactor, conduit 48 carries the cracked vapors, steam and fine catalyst particles to a primary separation zone comprising a main column 67. Fine particles carried over from the reaction zone will usually have a size in a range of from 0.2 to 40 microns. The concentration of these particles carried over by the gas stream will usually comprise from 0.5 to less 0.08 wt % of the gas stream. Most main columns will fractionate the cracked vapors into at least four streams comprising a gas stream, a naphtha stream, a cycle oil stream and a heavy oil or residual stream. The Figure shows main column 67 fractionating the vapors into five streams and withdrawing an overhead stream 68 containing a light naphtha fraction for further recovery as gasoline, a heavier heavy naphtha stream 69 for providing distillate and additional heavy gasoline, a next higher boiling cut in a line 70 comprising a light cycle oil, a yet higher boiling fraction 71 comprising heavy cycle oil and a heavy hydrocarbon bottoms steam in line 72.
As known to those skilled in the art, a gasoline fraction can be subdivided by the main column as shown or by other means into heavy and light gasoline cuts. The light gasoline fraction is typically withdrawn with an initial boiling point in the C 5 range and an end point in a range of 300-400° F. and, preferably, is withdrawn with an end point of about 380° F. The cut point for this fraction is preferably selected to retain olefins which would otherwise be lost by additional cracking to lighter components and saturation. The cut point may be controlled to optimize the octane barrels for the gasoline pool by the recycle of heavy gasoline. The heavy gasoline cut ordinarily comprises the next heavier fraction boiling above the light gasoline fraction. The naphtha stream of this invention generally corresponds to the heavy gasoline cut and will typically have a lower cut point in a range of from 250 to 380° F. and an upper cut point in a range of from 380° F. to 480° F. At the operating conditions of the main column, this upper cut point will be at about the boiling point of C 9 aromatics, in particular 1,2,4-trimethylbenzene. A lower cut point temperature for the naphtha fraction, down to about 320° F., but preferably above 360° F., will bring in additional C 9 aromatics. In its most basic form, the upper end of the naphtha cut is selected to retain C 12 aromatics. Therefore, naphtha will usually have an end point of about 400-430° F. and more preferably about 420° F.
The entire light gasoline fraction, and where desired heavier parts of the naphtha stream, may enter a gas concentration section that uses a primary absorber and, in most cases, a secondary absorber to separate lighter components from the gasoline stream using fractions from the main column or the gas concentration section as adsorption streams. A portion of the overhead stream 68 ordinarily returns to column 67 as reflux via a line 74. A portion of the heavy naphtha may also be refluxed to the column 67 via a line 75. Unless otherwise noted in this specification, the term "portion"--when describing a process stream--refers to either an aliquot portion of the stream or a dissimilar fraction of the stream having a different composition than the total stream from which it was derived.
The light cycle oil fraction recovered via conduit 70 will comprise the next hydrocarbon fraction having a boiling point above the heavy gasoline stream and will usually have an end boiling point in a range of about 450-700° F. Any net product stream of light cycle oil typically undergoes steam stripping (not shown) to meet flash point requirements before it is sent to product storage. A circulating light cycle oil fraction can also serve as a reboiling medium for one or more columns in the gas concentration section. After cooling any remainder of the light cycle oil stream is ordinarily refluxed to the column 67 via line 73.
The heavy cycle oil will have a boiling point in a range of about 500-750° F. After withdrawing a net portion of the heavy cycle oil for recycle to the riser or as a net product from fraction 71, the remainder is typically heat exchanged for heat recovery and recycled to the main fractionator 67 via a line 76. The heavy cycle oil stream will also normally provide a 475 to 650° F. hot stream for reboiling one or more columns in the gas concentration section. The recovered energy is also utilized to provide the final preheat for the feed to the riser and for the generation of high pressure steam. At other times, a net amount of this stream is withdrawn and recycled with the fresh feed to the reactor riser.
A portion of the heavy hydrocarbon stream from line 72 passes, after heating, to the main fractionator 67 via line 77. The remaining portion of the heavy hydrocarbon stream is withdrawn by line 78 for other processing such as the removal of fine catalyst particles. Preferably, the remaining portion of the heavy hydrocarbon stream carried by line 78 will enter a means for concentrating solids and recovering clarified oil that is relatively free of particulate material. By "relatively free of particulate material," it means that the concentration of the particulate material will ordinarily be at a level of less than 0.05 wt % of the clarified oil. FIG. 1 shows a concentrator in the form of a slurry settler 79 that receives the particle containing stream from line 78.
The clarified stream from settler 79 exits overhead via line 80. Line 80 will normally comprise heavy bottoms from the main column 67 which may be removed as a product stream via line 81 or, more typically, be recycled at least in part via line 82 to the feed stream via line 18.
A recycle stream containing a relatively high concentration of the solids--typically in a range of from 0.5 to 10 wt %--leaves the bottom of settler 79 via a line 83 and may be recycled directly to stripping zone 14 via a line 84. A preferred form of this invention, a line 85 carries at least a portion of the concentrated solid stream from line 83 into an additional concentrator that further reduces the amount of hydrocarbon entering stripper 14. When provided, additional concentrator 86 will typically raise the concentration of solids in the conveying stream or vehicle to a range of from 1 to 50 wt %. FIG. 1 shows a hydroclone as the concentrator 86 that receives the slurry from line 85 and produces a further clarified oil stream 87 and an underflow of highly concentrated solids. The highly concentrated flow of solids will ordinarily flow directly back into stripper 14 via lines 88 and 66. The clarified stream 87 depending upon its concentration of particulate material may be recovered directly as a product stream or recycled back to the main column for further separation into additional fractions or further removal of particulate material. The clarified stream 87 may also be returned as recycle to the riser via line 18.
An alternate arrangement for concentrating the solids recovered from the main column 67 via the bottoms stream in line 72 is shown in FIG. 2. FIG. 2 uses like reference numerals from FIG. 1 to describe the same elements shown in FIG. 2. In the arrangement shown in FIG. 2, the remainder of the bottoms stream in line 72 that does not reenter column 67 as recycle via line 77 passes via line 78' to a particulate filter system 90. Filter system 90 removes a majority of the fine particles from the bottom stream in line 78' and produces a clarified bottom stream 91 having a fines concentration that is typically in a range of from 0.05 to 0.005 wt %. A portion of the fines bottom stream may be withdrawn by line 92 for further process or recovery as product while any remainder will typically return to the riser for further cracking via a line 93. Filtration system 90 uses a portion of the light cycle oil from line 70, transferred thereto via a line 94, to purge the fine particulates from the filter element. The portion of the light cycle oil stream containing the fine particles passes out of filtration system 90 via line 95 and can again be passed directly to the reactor stripper 14 via a line 96. Additional concentration of the light cycle oil may be accomplished by passing it via a line 97 to hydroclone 98 for additional removal of particulate material from the light cycle oil and for minimization of the amount of light cycle oil passing as underflow into stripper 14 via a lines 99 and 66. The light cycle oil recovered as overflow from the hydroclone 98 via line 100 may pass back to the main column via line 101 for further processing and possible recovery of fines in the main column or, given a low enough fines concentration, may be combined directly via line 102 with the net light cycle oil stream recovered from the main column 67 via line 70.
The main column bottoms and heavy cycle oil are not preferred as vehicles for return of the recovered fine material to the stripper zone. The main column bottoms as well as the heavy cycle oil will have relatively low volatility and will tend to remain adsorbed on the catalyst particles as it passes through the stripper. Any hydrocarbons recycled directly to the stripper that remain on the catalyst as it passes into the regenerator will reduce product yield and increase delta coke.
Light cycle oil with its lower boiling points and higher volatility is a more suitable vehicle for returning the recovered fine particles to the relatively dense bed of the reactor stripping zone. Light cycle oil that contacts the catalyst will again be stripped in large measure before withdrawal of the catalyst from the bottom of the stripping zone. Therefore, light cycle oil will minimize any increase in delta coke or loss of products by its use as a vehicle for return of the fine particle directly to the stripping zone.
It is preferred that the particles be added to the stripping zone at a location near the top of the dense bed. Adding the particles near the top increases the amount of stripping that is available to remove the additional hydrocarbon that transport the fine particles without adsorbtion of the hydrocarbon on to the catalyst. However, there should be some length of bed above the injection point in order to hold the fines in the bed. Lighter materials for carrying the fine material back into the stripping zone, while more easily stripped, are not preferred due to the additional flashing and possible reentrainment of fine particles with the rising product vapors that return to the main fractionator.
EXAMPLE
The following example shows the use of the particle recycle arrangement of this invention to reduce the concentration of the fine catalyst particles--having a size of less than 40 microns--in circulation through the main column bottoms. This example is based on engineering calculations and operating data obtained from similar systems and operating FCC units. The table sets forth two cases. The conditions for the two cases are identical except that the first case recycles the recovered fines from the slurry system directly to a reactor riser and the second case recycles the recovered fines from the slurry system to an FCC stripping zone. The resulting comparison shows a reduction in the concentration of the catalyst fines entering the main columns from 320 lbs/hr for the first case to 80 lbs/hr for the second case.
______________________________________ Case: Case 1 Case 2______________________________________Nominal Unit Capacity, BPSD (barrels/stream day) 50,000 50,000Total Overhead to Main Fractionator, Lbs/hr 722,218 722,218Heavy Oil Product, BPSD 5208 5208Light Cycle Oil Product, BPSD 9896 9896Naphtha Sidedraw Product, BPSD 3499 5588Ovhd Receiver Vapors to Compressor, MMSCFD 57.64 58.52______________________________________
In both cases an FCC unit is operated to process 50,000 barrels/stream day of a vacuum gas oil feed. The feed is contacted with a catalyst and lift gas mixture in the bottom of a reactor riser and enters a reactor vessel that operates at a pressure of about 25 psig. Lift gas consists of approximately 2 wt. % steam and 2 wt. % light hydrocarbon based on feed. An additional 2 wt. % of steam is injected to atomize the heavy oil feed. Product hydrocarbons are disengaged from the catalyst in the disengaging chamber and a riser cyclone. The catalyst travels downwardly through a first stage of a stripping section that operates at approximately the same temperature as the upper end of the reactor riser. Catalyst passing through the stripper is contacted with gas that enters the bottom of the stripper. The stripping gas volume provides a superficial gas velocity through the stripper of 0.5 ft/sec and first contacts the spent catalyst in the lower section of the stripper. The stripping gas removes absorbed hydrocarbons from the surface of the catalyst and the stripping gas becomes mixed with light paraffins and hydrogen. The stripping gas mixture consisting of gases and vapors passes upwardly from the lower section of the stripper and is collected in an upper section of a reactor vessel. The gaseous mixture in the upper portion of the reactor vessel passes into the same cyclone separators that receive the riser products. All of the products, in the form of highly superheated vapors from the reaction zone, are transferred directly to a primary fractionation zone where they are fractionated into the various fractions of various boiling point ranges.
At the bottom section of the column, both cases withdraw a net heavy oil product. The operating temperature in this section ranges from 650 to 725 degrees F, and heat in excess of that required for fractionation of the lighter components is recovered in a bottoms circulating stream. Both examples have a heavy cycle oil (HCO) pumparound incorporated at a section above the bottoms section. The section above the HCO pumparound is the light cycle oil (LCO) product draw and circulation section. Net LCO product with a 450-700 deg. F boiling range is netted from this section. The naphtha product and circulation section is located above the LCO section. The net naphtha product sidedraw with a typical boiling range of 250-450 deg. F, is processed in a steam stripper (not shown) in order to stabilize it and meet vapor pressure requirement. In these examples, the bulk of the circulating streams are heat exchanged for heat recovery and returned to the main fractionator.
In both cases the bottoms stream from the main column enters a slurry settler that effects an approximate 50% removal of fines from the net portion of the main column products and rejects about 5200 BPSD of a bottoms stream containing 0.01 wt % solids. In case 1, 2000 BPSD of main column bottoms containing 312 lbs/hr of fine catalyst particles were returned to the FCC riser. In Case 2, 2000 BPSD of main column bottoms containing about 72 lbs/hr of fine particles were returned to the the FCC stripping section. In case 1 approximately 76,200 lbs/hr of product leaving the cyclones of the reactor vessel carried over about 320 lbs/hr of solids. In case 2 approximately 76,200 lbs/hr of product leaving the cyclones carried over only about 80 lbs/hr of solids.
Case 2 of the example demonstrates the substantial reduction in ciruculating fines that was obtained by the method and apparatus of this invention.
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The invention improves a system and apparatus for the recovery of fine solid particles entering the slurry system of a fluidized catalytic contacting process by returning a portion of the recovered solids from the main separator directly back to the reactor stripper. The invention recovers fine particulate material from an FCC main column and returns the particulate material to an FCC stripper to reduce the amount of fine material that continues to recycle through the FCC reactor and product separator. By returning fine particulate material from the FCC product separation zone directly to a low velocity area of the stripping section, the invention breaks the reactor--main column recycle loop that concentrates the fines. Fines entering the reactor stripper will not be carried back into the cyclones for unwanted return to the main column. By the recycling of fines to the stripper via this invention, the fines concentration in the slurry system can decrease by up to 300%.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of flank milling, and more particularly, the manufacturing of rotor components of turbomachinery, such as impellers and blisks.
2. Description of the Prior Art
The manufacture of radial turbomachinery, including centrifugal compressor impellers and axial compressor or turbine rotors, was either done by casting or by machining. In the case of a centrifugal impeller, casting is the most common method. However, there are well-known problems associated with casting, such as shrinkage and distortion of thin blade sections. The resulting inaccuracies in casting of the blades on an impeller make it impractical to consider fine tuning of the designs since manufacturing errors, in fact, exceed any such changes. As far as milling or machining an impeller blade from a solid block such as a titanium block is concerned, it has been known to use a point milling system on a multi-axis milling machine whereby the surface of the blade is predetermined and each minute area of the surface is machined by the tip of a drill bit. Such milling machines are numerically controlled, and the programs or tapes for operating point milling of an impeller, for instance, is, as can be readily understood, intolerably long and the machining process is time consuming.
Attempts have been made in the past to use flank milling techniques. It is generally conceived that a surface is flank millable if it can be closely approximated to a surface generated by a straight line or a ruled surface. Even given such a surface, the problems of defining the tool path and the cutter feed rate are complex. To complicate the problem further, the milled surface may deviate from the ruled surface, sometimes quite significantly, owing to the twist of the surface along a straight line component. Such deviations have hitherto been ignored or minimized by compromising the aerodynamic design of the blade.
In spite of such difficulties, flank milling has been increasingly used since it offers improved productivity relative to point milling. As described in "A Software System for the Automated Numerical Control Machining of Radial Turbomachinery", a brochure published by Northern Research and Engineering Corporation, of Woburn, Mass., flank milling can lend itself to the manufacture of centrifugal impellers for aviation turbomachinery since the blades' surfaces of such impellers can be designed by straight line generation or ruled surfaces without significant compromise of the aerodynamic design. On the other hand, axial compressor rotors hardly lend themselves to flank milling because of the twist in the blades. Even though flank milling is now well accepted for the manufacture of impellers, compressor or turbine rotor disks are still manufactured as separate blades and disks (rotor hub). The individually forged blades are attached to the disk with a conventional fir tree root arrangement and are riveted to the disk. Attempts have been made to mill a rotor with integral blades from a solid forged blank giving rise to the coined term "blisk" from the words "blade" and "disk". For the purposes of the present specification, the word "blisk" will be utilized.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a method whereby the obvious advantages of flank milling can be utilized in a manufacturing method for producing more complex surfaces, that is, surfaces which are not readily analyzed as ruled surfaces, such as in the formation of blisks for turbomachinery as well as to turbomachinery impellers with blades having increased design sophistication, that is, not limited to straight line generation.
A further aim of the present invention is to provide a method of predicting a resulting surface from a proposed surface design and to better program a numerically controlled flank milling machine for producing such a surface.
It is a further aim of the present invention to provide a method of flank milling non-ruled surfaces of turbomachinery by providing for multiple finishing passes of the cutter tool and coordinating the number of passes to provide matching of said passes.
Given a surface to be machined, a method of flank milling in accordance with the present invention comprises the steps of first determining a surface to be machined, selecting discrete portions of said surface, determining three or more reference surfaces intersecting said discrete surface, the intersection of said reference surfaces with the proposed surface resulting in reference lines, selecting a point on one of said reference lines and determining a straight line passing through said selected point and intersecting with two other adjacent reference lines, orienting the rotating axis of a cutting tool relative to the discrete surface, determining and programming the best cutter tool position to correspond to the selected straight line and repeating the method until all cutter tool positions have been determined, making a first finishing pass to machine a ruled surface between at least two reference lines, and repeating the process for making further passes between other reference lines.
In a more specific method of the present invention, at least three reference lines are selected with the number of lines being proportional to the degree of curvature of the surface such that three adjacent reference lines are selected and at least one straight line can intersect three adjacent reference lines or at least approximate an intersection with the third line, and in a first instance, determining a straight line relative to a predetermined point in a first reference line and the points of intersection of said straight line in a second and third reference line is determined from which the position of the cutting tool can be determined for a first pass at least between adjacent reference lines, and a point is determined on a second reference line and the points of intersection on third and fourth lines of a straight line passing through the selected point on the second line is determined for a second pass of the cutter tool at least between two other reference points.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration, a preferred embodiment thereof, and in which:
FIG. 1 is a perspective view of a schematic representation of a detail of a 5-axis milling machine;
FIG. 2 is a diagram of the end of a cutting tool;
FIG. 3 is a diagram of a detail of the method of the present invention;
FIG. 4 is a diagram of a detail shown in FIG. 3;
FIG. 5 is a diagram showing the orientation of a tool cutter axis relative to the axis of a turbomachinery blisk/impeller to be machined;
FIG. 6 is a diagram comparing the tool coordinate system with the blisk coordinate system;
FIG. 7 is a diagram showing three cutter tool positions;
FIG. 8 is a cross-section through one of the reference planes of the three cutter tool positions shown in FIG. 7; and
FIGS. 9a-f are a plurality of diagrams showing the cutter tool with different complex surfaces.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and more particularly to FIG. 1, a 5-axis milling machine is schematically illustrated and referred to by the numeral 10. The cutter tool is represented by the numeral 12 and includes a conical cutting tool as illustrated in FIG. 2. The milling machine 10 could be a 5-axis milling machine, such as a Sundstrand OM-1 5-axis NC milling machine. The five movements of the machine are represented as follows by two rotary movements B and C and three translatory movements X, Y and Z. The cutter tool 12, as shown in FIG. 2, is preferably a conical cutter having a conical surface angle η to the axis Pi of the tool. The tool has a spherical tip 14. It has been found that such conical cutting tools have better strength than the cylindrical tool, and tool deflection and breakage are minimized. R BE is the ball-end radius of the tool. (P 1 , X 1 , S 1 ) is a left-handed rectangular coordinate system with its origin at the tip of the ball end. For P i >PLIM, the cutter surface is conical; for P i ≦PLIM, it is spherical.
A blisk, now shown, may be manufactured from a solid annular titanium blank 16. On a predetermined design blade surface shown in dotted lines in FIG. 3, four planes have been defined which intersect the proposed blade surface and result in reference lines C1, C2, C3 and C4 on the surface of the blade.
It has been found that for a typical ruled surface, anywhere from 20 to 50 straight lines are needed for each blade surface. Thus, 20 to 50 points are selected on any one of the various reference lines C1, C2, C3 and C4, and ruled surfaces are determined joining three reference lines, thereby ensuring that any straight line defining a ruled surface extends and intersects at least three reference lines. For instance, in FIG. 4, if point 2 is selected on C2, we extend straight lines through point 2, past point 3 on C3 until they intersect the surface of revolution formed by C4. By numerical interpolation, the coordinates of the straight line intersecting all three reference lines can be exactly determined. By repeating this analysis through 20 to 50 points, the number of straight lines, all passing through at least three adjacent reference lines, can be determined and transposed to the program for operating the cutting tool. Depending on the position of the straight lines, a determination can also be made as to the number of cutting tool passes which will be needed to complete the surface of the given rotor blade.
Referring now to FIG. 5, the cutter is shown relative to the rotor. The 5-axis coordinates are ψ, θ, L, R, A, plus three parameters B, C, and φ, which are offset constants for a particular blade surface. The orientation of the tool axis is defined by ψ and θ, while R is the distance between the tool axis and the rotor axis. B gives the projection of the radial coordinate of the tool pivot point on the plane containing the tool axis. The letter C in FIG. 5 denotes the axial coordinate of the tool pivot point, while the letter A is the distance of the tool axis from the tool pivot point, and is the angle between the vertical and the leading edge datum plane of the blade. The tool axis lies on the P'O'X' plane.
Reference is made to a paper entitled "Tool Positioning and Feedrate Problems in Impeller Flank Milling" by C. Y. Wu, Y. Altintas, and R. A. Thompson, Proceedings of 1982 Canadian Conference on Industrial Computer Systems, McMaster University, Hamilton, Ontario, Canada (May 1982), (Canadian Industrial Computer Society). It is understood that the following determination is typical to the milling machine described hereinabove. Other known methods may be used depending on the milling machine used.
An important step is to transfer the five coordinates into rectangular coordinates with respect to the rest frame of the rotor. P, X, S is the system that rests with respect to the rotor, with the X-axis along the axis of the rotor and pointing from the leading edge towards the trailing edge. Pi, Xi, Si is the rectangular coordinate system in the rest frame of the tool at position i. The Xi-axis is chosen to be in the plane P'O'X' of FIG. 5. Then a point on which coordinates are Pi, Xi, Si on the tool coordinate system becomes the point P, X, S on the rotor coordinate system with: ##EQU1## where (T Pi , T Xi , T Si ) is the coordinate vector of the tool ball end tip in the rest frame of the rotor. It is given by ##EQU2## with
D=B-L cos ψ-A sin ψ (3)
Given a point (Pi, Xi, Si) with respect to the tool coordinate system at position i, this transformation allows one to compute its coordinate (Pj, Xj, Sj) with respect to the tool coordinate system at position j (FIG. 6). The relative orientation of the two coordinate systems set up at the ball end tip 14 of the tool 12, and the coordinate system at rest with the rotor is shown in FIG. 6. Two inclined planes can be constructed with their common edge coinciding with the rotor axis, that is, the X-axis. Pi lies on the inclined plane which makes an angle λ i with the vertical P-axis. Pj lies on the inclined plane which makes an angle λj with the P-axis, where
λ.sub.i =φ-θ.sub.i
λ.sub.j =φ-θ.sub.j (4)
θ i and θ j being the θ values of the 5-axis coordinate θ at tool positions i and j. Pi and Pj axes make angles ψ i and ψ j with the PS plane; where again ψ i and ψ j are the ψ values of the 5-axis coordinate ψ at tool positions i and j.
Xi-axis is chosen to lie on the inclined plane containing the Pi-axis. This completely defines the (Pi, Xi, Si) coordinate system. We then chose the Xj-axis to lie on a plane parallel to the inclined plane containing Pi and Xi for reasons which will soon be clear. Thus we have also completely specified the (Pj, Xj, Sj) coordinate system.
γ 1 is the angle between the Pj-axis and the inclined plane containing Pi and Xi. If the Pj- and Sj-axis is rotated by an angle -γ 1 about the Xj-axis, then both the Pj- and Sj-axis would lie on a plane parallel to the inclined plane containing Pi and Xi. The rotated Pj-axis now makes a different angle with the PS plane. This angle is equal to γ 3 in FIG. 6. Now if another rotation of angle γ 2 =γ 3 -ψ i about the Sj axis is applied, the j th tool coordinate system has been made parallel to the i th tool coordinate system.
The angles γ 1 and γ 2 are readily obtained by arbitrarily assigning OA=1, then it is simple trigonometry that
γ.sub.1 =sin.sup.-1 (sin (θ.sub.j -θ.sub.i) cos ψ.sub.j)
γ.sub.2 =tan.sup.-1 (tan ψ.sub.j sec (θ.sub.j -θ.sub.i))-ψ (5)
The matrix of rotation associated with a rotation of -γ 1 about the Xj-axis is ##EQU3## and that associated with a rotation of γ 2 about the Sj-axis is ##EQU4##
Referring to FIG. 6 again, let Ti and Tj be the vectors from the origin of the rotor reference frame to the tip 14 of the tool at positions i and j respectively; then ##EQU5## gives the separation of the j th tool tip from the i th tool tip, measured in the rest frame of the rotor. However, this separation is to be obtained measured in the i th tool position coordinate system. This is again achieved by applying two rotations to T. The first is an angle λ i about X-axis: ##EQU6## Then we rotate -ψ i about the S-axis ##EQU7##
Putting all the previous considerations together, one may see that given any point (Pj, Xj, Sj) in the j th tool reference frame, its coordinates in the i th tool reference frame are ##EQU8## where T as given by (8) is readily obtained by applying equation (2).
In order to determine the line of contact between the tool at position i and the straight lines determined as previously mentioned, one can consider a triplet of adjacent tool positions as illustrated in FIG. 7. If a line of contact at tool position 2 is required, a family of reference planes perpendicular to the P 2 -axis are constructed at different values of P 2 . The cross-sections of the tool at position 2 with the reference planes are always circles as shown in FIG. 8. Thus, the cross-sections of the tool 12 at positions 1 or 3 can be an ellipse, circle or part ellipse and part circle, depending on whether the reference plane cuts the conical surface part or the spherical ball end part or both parts of the tool.
Referring to FIG. 8, the conic sections 1, 2 and 3 will be referred to. Between the conic sections 1 and 2, common straight line tangents can be constructed, one on each side of the straight line joining their centers. Let σ 1 and ρ 1 be the angular positions of the tangency points on the second tool position, measured with respect to the S 2 -axis. Similarly, between the tool positions 2 and 3, σ 3 and ρ 3 are the tangency points. If the three tool positions are sufficiently close together and the tool positions are smoothly varying, then σ 1 ≈σ 3 and ρ 1 ≈ρ 3 (note, however, that σ 1 ≠σ 3 ±180°, ρ 1 ≠ρ 3 ±180°) and σ 2 =(σ 1 +σ 3 )/2, ρ 2 =(ρ 1 +ρ 3 )/2 give the angular positions of the points of contact on the sectioning plane between the tool at position 2 and the resultant surfaces. In reality, only one of these, either σ 2 or ρ 2 give the point of contact with the blade surface, be it on the pressure surface side or on the suction surface side, while the other point of contact relates to the tool clearance surface. It is, of course, important that a tool clearance surface be provided so that the tool does not cut into the blade surface of an adjacent blade.
In order to carry out this procedure, each conic section shown in FIG. 8 must be expressed mathematically in a common coordinate system chosen to be the (P 2 , X 2 , S 2 ) system. In its own reference frame, the tool surface at position j is described by
Xj.sup.2 +Sj.sup.2 =αPj.sup.2 +βPj+γ (12)
where for Pj≦PLIM=R BE (1-sin η)
α=-1
β=2R.sub.BE
γ=0, (13)
we have a spherical surface. While for Pj>PLIM,
α=tan.sup.2 η
β=2R.sub.BE tan η(sec η-tan η)
γ=R.sub.BE (sec η-tan η).sup.2 (14)
we have a conical surface.
For tool position 2, the circular cross-section is described by letting P 2 equal to the height of the sectioning plane H from the tip of the ball-end. For positions 1 or 3, however, the first equation (12) must be transformed by using equation (11) so that the tool surface can be described in the reference frame (P 2 , X 2 , S 2 ); then P 2 is set equal to H. In general, this leaves an equation of the form
aS.sub.2.sup.2 +bX.sub.2.sup.2 +cS.sub.2 X.sub.2 +dS.sub.2 +eX.sub.2 +f=0 (15)
where a, b, c, d, e, and f are constants independent of S 2 , X 2 ; but depends on all the parameters we have defined by equations (2) through (11).
Equation (15) can describe any conic section in general. However, what we have here is either a circle, or a near circle ellipse because the reference plane is always nearly perpendicular to the tool axis. If the reference plane is well above the spherical ball end of the tool at position 1 or 3, then an elliptic cross-section is what is important; otherwise, two different equations (15) must be considered, one describing an ellipse associated with the conical surface, and the other describing a circle associated with the spherical ball-end surface, for each of the tool positions at 1 or 3.
To find the tangency point for conic sections 1 and 2, the following procedure is followed. At any angular position σ on conic section 2, we can obtain a tangent to it defined by
X.sub.2 =mS.sub.2 +n (16)
where m and n are the slopes and intercept. Solving (15) and (16) simultaneously for S 2 , provides a quadratic equation. If the discriminant of this equation is positive, the tangent cuts conic section 1 at two real points; if the discriminant is negative, the tangent misses conic section 1; if it is zero, the tangent just touches conic section 1 and it is therefore the common tangent we are looking for. In experiments, the search for the common tangent was done iteratively, using the method of bi-sectioning. In the case when the sectioning reference plane is well above the ball end, the correct σ in one such search was obtained. If the sectioning plane is close to the ball end, however, after obtaining the common tangent when conic section 1 is entirely on the conical surface, a test must be made as to whether or not the tangency point on conic section 1 is a point on the conical surface of the real tool. To do so, the coordinates of the tangency point on conic section 1 in the (P 2 , X 2 , S 2 ) frame must be computed. This is then transformed to the P 1 , X 1 , S 1 frame using equation (11). If P 1 >PLIM, the tangency point we obtained is a real point on the tool and the common tangent has been found. Otherwise, the common tangent is fictitious, and the search must be repeated. This time, however, conic section 1 is a circle lying entirely on a sphere of radius R BE . After finding σ 1 and ρ 1 by constructing common tangents between conic sections 1 and 2, the same procedure to find σ 3 and ρ 3 between conic sections 3 and 2 is repeated. The averages of the σ s and ρ s provide the angular positions of the points of contact. Their coordinates in the (P 2 , X 2 , S 2 ) frame are readily obtained. Then, equation (1 ) is used to transform them to the rest frame of the rotor.
By repeating the above procedure with different sectioning reference planes, as many points of contact as wanted can be obtained between the surfaces and the tool at a certain tool position. These points then define the lines of contact.
The above procedure gives us the projected milled surface of the blade. This can now be compared with the earlier described procedure for determining the ruled surface or the straight line analysis of discrete portions of the blade. The milled surface should be compared with the design surface before actual milling is done to determine whether the milled surface is acceptable. Such back generation is done by stacking 20 to 50 lines of contact of particular surface defining the milled surface. The coordinates of any point on the blade surface can be readily interpolated.
From the back generated surfaces, the design surfaces can be compared with the predicted milled surfaces. In a particular example, a rotor blade was compared at its tip, its mid section and near the hub. Between the tip and mid section, the milled surface was within proper tolerances. Below the mid section, discrepancy between the design and back generated milled surfaces increased such that the maximum deviations for each surface, near the trailing edge, approaches 0.050 inch, i.e., the milled surface would be 0.100 inch thicker than the design blade profile near the hub section trailing edge. This was unacceptable since the design blade had a thickness of 0.030 inch.
While the rough passes remain unchanged, a second finishing pass was introduced. This time the conical cutting surface of the tool was matched to the straight line of the reference lines C3 and C4. This gave the proper contour to the blade between the mid and hub sections. If the second pass did not cut into this blade surface between the tip and the mid section which were cut during the first pass, and if the two passes join smoothly along the mid line of the blade, satisfactory results would be obtained. In the particular example, the second pass resulted with surfaces from the first pass overlapping closely with the ruled surface.
It was only after the back generation had been carried out and further passes had been made that the numerical controlled tape was prepared for the 5-axis machine.
Referring now to FIG. 9, there is shown, schematically in 9a to 9c, a convex surface being cut in successive passes by the conical cutting tool. In the case of a concave surface, the cutting tool can be shaped as shown in FIGS. 9a to f. These latter Figures show the cutting of the concave surface by three successive passes. Note that each pass covers a discrete area where a straight line can be approximated. It is understood that the size of the discrete areas, i.e., the distance between the intersecting planes C1, C2, C3, C4, is determined by the degree of curvature of the surface.
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A method of flank milling complex surfaces comprising the steps of analyzing the design surface to determine discrete areas in which straight lines can be drawn, determining straight lines in the discrete areas, transposing the coordinates of these straight lines and comparing them with the flank tool cutter positions, determining the tool positions to said straight lines, back generating the contact lines of said surface and comparing these with the design surface, determining the number of passes of said cutter tool and generating data for numerical control machining.
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